Insulin-producing cells generated from dedifferentiated human pancreatic beta cells expanded in vitro.

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Holger A Russ

Full Text Available Expansion of beta cells from the limited number of adult human islet donors is an attractive prospect for increasing cell availability for cell therapy of diabetes. However, attempts at expanding human islet cells in tissue culture result in loss of beta-cell phenotype. Using a lineage-tracing approach we provided evidence for massive proliferation of beta-cell-derived (BCD cells within these cultures. Expansion involves dedifferentiation resembling epithelial-mesenchymal transition (EMT. Epigenetic analyses indicate that key beta-cell genes maintain open chromatin structure in expanded BCD cells, although they are not transcribed. Here we investigated whether BCD cells can be redifferentiated into beta-like cells.Redifferentiation conditions were screened by following activation of an insulin-DsRed2 reporter gene. Redifferentiated cells were characterized for gene expression, insulin content and secretion assays, and presence of secretory vesicles by electron microscopy. BCD cells were induced to redifferentiate by a combination of soluble factors. The redifferentiated cells expressed beta-cell genes, stored insulin in typical secretory vesicles, and released it in response to glucose. The redifferentiation process involved mesenchymal-epithelial transition, as judged by changes in gene expression. Moreover, inhibition of the EMT effector SLUG (SNAI2 using shRNA resulted in stimulation of redifferentiation. Lineage-traced cells also gave rise at a low rate to cells expressing other islet hormones, suggesting transition of BCD cells through an islet progenitor-like stage during redifferentiation.These findings demonstrate for the first time that expanded dedifferentiated beta cells can be induced to redifferentiate in culture. The findings suggest that ex-vivo expansion of adult human islet cells is a promising approach for generation of insulin-producing cells for transplantation, as well as basic research, toxicology studies, and drug

TRIENNIAL GROWTH AND DEVELOPMENT SYMPOSIUM: Dedifferentiated fat cells: Potential and perspectives for their use in clinical and animal science purpose.

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Duarte, M S; Bueno, R; Silva, W; Campos, C F; Gionbelli, M P; Guimarães, S E F; Silva, F F; Lopes, P S; Hausman, G J; Dodson, M V

2017-05-01

An increasing body of evidences has demonstrated the ability of the mature adipocyte to dedifferentiate into a population of proliferative-competent cells known as dedifferentiated fat (DFAT) cells. As early as the 1970s, in vitro studies showed that DFAT cells may be obtained by ceiling culture, which takes advantage of the buoyancy property of lipid-filled cells. It was documented that DFAT cells may acquire a phenotype similar to mesenchymal stem cells and yet may differentiate into multiple cell lineages, such as skeletal and smooth muscle cells, cardiomyocytes, osteoblasts, and adipocytes. Additionally, recent studies showed the ability of isolated mature adipocytes to dedifferentiate in vivo and the capacity of the progeny cells to redifferentiate into mature adipocytes, contributing to the increase of body fatness. These findings shed light on the potential for use of DFAT cells, not only for clinical purposes but also within the animal science field, because increasing intramuscular fat without excessive increase in other fat depots is a challenge in livestock production. Knowledge of the mechanisms underlying the dedifferentiation and redifferentiation of DFAT cells will allow the development of strategies for their use for clinical and animal science purposes. In this review, we highlight several aspects of DFAT cells, their potential for clinical purposes, and their contribution to adipose tissue mass in livestock.

Evidence for heterogeneity of astrocyte de-differentiation in vitro: astrocytes transform into intermediate precursor cells following induction of ACM from scratch-insulted astrocytes.

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Yang, Hao; Qian, Xin-Hong; Cong, Rui; Li, Jing-wen; Yao, Qin; Jiao, Xi-Ying; Ju, Gong; You, Si-Wei

2010-04-01

Our previous study definitely demonstrated that the mature astrocytes could undergo a de-differentiation process and further transform into pluripotential neural stem cells (NSCs), which might well arise from the effect of diffusible factors released from scratch-insulted astrocytes. However, these neurospheres passaged from one neurosphere-derived from de-differentiated astrocytes possessed a completely distinct characteristic in the differentiation behavior, namely heterogeneity of differentiation. The heterogeneity in cell differentiation has become a crucial but elusive issue. In this study, we show that purified astrocytes could de-differentiate into intermediate precursor cells (IPCs) with addition of scratch-insulted astrocyte-conditioned medium (ACM) to the culture, which can express NG2 and A2B5, the IPCs markers. Apart from the number of NG2(+) and A2B5(+) cells, the percentage of proliferative cells as labeled with BrdU progressively increased with prolonged culture period ranging from 1 to 10 days. Meanwhile, the protein level of A2B5 in cells also increased significantly. These results revealed that not all astrocytes could de-differentiate fully into NSCs directly when induced by ACM, rather they generated intermediate or more restricted precursor cells that might undergo progressive de-differentiation to generate NSCs.

Dedifferentiated chondrosarcoma: use of MRI to guide needle biopsy

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Saifuddin, A. E-mail: asaifuddin@aol.com; Mann, B.S.; Mahroof, S.; Pringle, J.A.S.; Briggs, T.W.R.; Cannon, S.R

2004-03-01

AIM: To describe the use of MRI to identify and biopsy areas of dedifferentiation in patients with a suspected diagnosis of dedifferentiated chondrosarcoma. MATERIALS AND METHODS: Low-grade chondrosarcoma is characterized at magnetic resonance imaging (MRI) as having a lobulate, hyperintense appearance on T2-weighted spin-echo sequences. T2-weighted MR images were assessed in 15 patients with a final pathological diagnosis of dedifferentiated chondrosarcoma for regions of atypical reduced signal intensity. Information regarding the site of ultrasound or computed tomography (CT)-guided biopsy was available in 10 cases. RESULTS: Nine patients were male and six female with a mean age of 60 years (range 25-77 years). The sites involved were the distal femur (n=4), pelvis (n=3), proximal femur (n=4), femoral diaphysis (n=1), proximal humerus (n=2) and proximal tibia (n=1). The dedifferentiated component consisted of osteosarcoma (n=5), malignant fibrous histiocytoma (n=6), spindle cell sarcoma (n=1), leiomyosarcoma (n=1) and pleomorphic sarcoma (n=1). In 14 of the 15 cases, areas of lower signal intensity lacking in lobulation were identified. In nine of the 10 cases, biopsy site included such areas and yielded high-grade sarcoma. CONCLUSIONS: Dedifferentiation within chondrosarcoma may be identified on T2-weighted MRI as areas of reduced signal intensity. These areas should be the preferred site of biopsy.

Dedifferentiated Chondrosarcoma of the Larynx.

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Fidai, Shiraz S; Ginat, Daniel T; Langerman, Alexander J; Cipriani, Nicole A

2016-09-01

Primary dedifferentiated chondrosarcoma occurring in the larynx is a rare head and neck malignancy. The cases reported in the literature suggest male gender predilection and variable clinical outcomes ranging from disease-free survival to disease-related death. Although a calcified matrix is suggestive of chondrosarcoma, the dedifferentiated component is not readily appreciated on conventional imaging modalities and thorough tissue sampling is necessary for confirming the diagnosis. Histologically, there is an abrupt transition from a well-differentiated chondrosarcoma to a high-grade spindle cell component, which can show focal heterologous differentiation. These features are exemplified in this sine qua non radiology-pathology correlation article.

Lin28B promotes Müller glial cell de-differentiation and proliferation in the regenerative rat retinas

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Tao, Zui; Zhao, Chen; Jian, Qian; Gillies, Mark; Xu, Haiwei; Yin, Zheng Qin

2016-01-01

Retinal regeneration and repair are severely impeded in higher mammalian animals. Although Müller cells can be activated and show some characteristics of progenitor cells when injured or under pathological conditions, they quickly form gliosis scars. Unfortunately, the basic mechanisms that impede retinal regeneration remain unknown. We studied retinas from Royal College of Surgeon (RCS) rats and found that let-7 family molecules, let-7e and let-7i, were significantly overexpressed in Müller cells of degenerative retinas. It demonstrated that down-regulation of the RNA binding protein Lin28B was one of the key factors leading to the overexpression of let-7e and let-7i. Lin28B ectopic expression in the Müller cells suppressed overexpression of let-7e and let-7i, stimulated and mobilized Müller glia de-differentiation, proliferation, promoted neuronal commitment, and inhibited glial fate acquisition of de-differentiated Müller cells. ERG recordings revealed that the amplitudes of a-wave and b-wave were improved significantly after Lin28B was delivered into the subretinal space of RCS rats. In summary, down-regulation of Lin28B as well as up-regulation of let-7e and let-7i may be the main factors that impede Müller cell de-differentiation and proliferation in the retina of RCS rats. PMID:27384999

[Dedifferentiated chondrosarcoma: radiologic-pathologic correlation].

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Bierry, G; Feydy, A; Larousserie, F; Pluot, E; Guerini, H; Campagna, R; Dufau-Andreu, C; Anract, P; Babinet, A; Dietemann, J L; Chevrot, A; Drapé, J L

2010-03-01

Dedifferentiated chondrosarcomas are highly malignant tumors characterized by conventional low-grade chondrosarcoma with abrupt transition to foci that have dedifferentiated into a higher-grade noncartilaginous more aggressive sarcoma. The dedifferentiated component, an osteosarcoma or fibrosarcoma, determines the prognosis. Its identification is key for management. A diagnosis of dedifferentiated chondrosarcoma should be suggested by the presence of "tumoral dimorphism" with cartilaginous component and aggressive lytic component invading adjacent soft tissues.

Tumor dedifferentiation: diagnostic and therapeutic implications

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Abhimanyu Jha

2017-09-01

Full Text Available Some of the neoplasm especially malignant tumors are notorious in masquerading their cell of origin because of additional mutations which drives them to differentiate into unusual phenotype. This is implicated to a phenomenon of tumor dedifferentiation which can mislead into inappropriate categorization and therapy. Dedifferentiation is well recognized in sarcomas such as liposarcoma, chondrosarcoma and MPNST. However, it can also develop in carcinomas, melanomas and lymphomas at initial diagnosis, following therapy or at recurrence.  The phenomenon has been reported in both primary tumors as well as at metastatic foci. A correct and early pathological identification of this phenomenon might profoundly help in guiding appropriate therapy. Clinical and radiological findings, immunohistochemistry and genetic analysis are often required for correct lineage identification of these tumors.

A multi-stage process including transient polyploidization and EMT precedes the emergence of chemoresistent ovarian carcinoma cells with a dedifferentiated and pro-inflammatory secretory phenotype.

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Rohnalter, Verena; Roth, Katrin; Finkernagel, Florian; Adhikary, Till; Obert, Julia; Dorzweiler, Kristina; Bensberg, Maike; Müller-Brüsselbach, Sabine; Müller, Rolf

2015-11-24

DNA-damaging drugs induce a plethora of molecular and cellular alterations in tumor cells, but their interrelationship is largely obscure. Here, we show that carboplatin treatment of human ovarian carcinoma SKOV3 cells triggers an ordered sequence of events, which precedes the emergence of mitotic chemoresistant cells. The initial phase of cell death after initiation of carboplatin treatment is followed around day 14 by the emergence of a mixed cell population consisting of cycling, cell cycle-arrested and senescent cells. At this stage, giant cells make up >80% of the cell population, p21 (CDKN1A) in strongly induced, and cell numbers remain nearly static. Subsequently, cell death decreases, p21 expression drops to a low level and cell divisions increase, including regular mitoses of giant cells and depolyploidization by multi-daughter divisions. These events are accompanied by the upregulation of stemness markers and a pro-inflammatory secretory phenotype, peaking after approximately 14 days of treatment. At the same time the cells initiate epithelial to mesenchymal transition, which over the subsequent weeks continuously increases, concomitantly with the emergence of highly proliferative, migratory, dedifferentiated, pro-inflammatory and chemoresistant cells (SKOV3-R). These cells are anchorage-independent and grow in a 3D collagen matrix, while cells on day 14 do not survive under these conditions, indicating that SKOV3-R cells were generated thereafter by the multi-stage process described above. This process was essentially recapitulated with the ovarian carcinoma cell line IGROV-1. Our observations suggest that transitory cells characterized by polyploidy, features of stemness and a pro-inflammatory secretory phenotype contribute to the acquisition of chemoresistance.

Dedifferentiated chondrosarcoma of the appendicular skeleton: MRI-pathological correlation

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MacSweeney, Fergus; Darby, Alan [Department of Histopathology, The Royal National Orthopaedic Hospital NHS Trust, Brockley Hill, HA7 4LP, Stanmore, Middlesex (United Kingdom); The London Bone and Soft Tissue Tumour Unit, London (United Kingdom); Saifuddin, Asif [The London Bone and Soft Tissue Tumour Unit, London (United Kingdom); Department of Radiology, The Royal National Orthopaedic Hospital NHS Trust, Brockley Hill, HA7 4LP, Stanmore, Middlesex (United Kingdom); Department of Diagnostic Imaging, The Royal National Orthopaedic Hospital NHS Trust, HA7 4LP, Stanmore, Middlesex (United Kingdom)

2003-12-01

To correlate the T2-weighted and STIR MRI appearances of dedifferentiated appendicular chondrosarcoma with gross and microscopic pathology. Nine patients with a histologically confirmed diagnosis of dedifferentiated appendicular chondrosarcoma were identified from the Bone Tumour Registry. All patients underwent MRI, including T2-weighted and/or STIR sequences in at least one plane, prior to limb salvage surgery. Areas of reduced signal intensity (SI) compared with hyperintense chondral tumour on the T2-weighted or STIR images were correlated with the resection specimen, to determine the relationship of such out areas of reduced SI with regions of dedifferentiation. Patients presented over a period of 7 years. There were five men and four women with mean age 68.2 years and age range 51-78 years. Tumours arose in the femur (6 cases), humerus (2 cases) and tibia (1 case). Three MRI patterns were identified: (1) type 1, a lesion with two distinct signal characteristics - hyperintense chondral and reduced SI dedifferentiated tumour (n=6); type 2, mainly reduced SI lesion - dedifferentiated tumour, with areas of signal void corresponding to matrix calcification (n=2); type 3, a heterogeneous lesion with no radiological evidence of underlying chondral tumour (n=1). T2-weighted or STIR MR sequences can identify areas of dedifferentiation, which should be the preferential site of pre-operative biopsy. (orig.)

Wilms’ Tumor Blastemal Stem Cells Dedifferentiate to Propagate the Tumor Bulk

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Shukrun, Rachel; Pode-Shakked, Naomi; Pleniceanu, Oren; Omer, Dorit; Vax, Einav; Peer, Eyal; Pri-Chen, Sara; Jacob, Jasmine; Hu, Qianghua; Harari-Steinberg, Orit; Huff, Vicki; Dekel, Benjamin

2014-01-01

Summary An open question remains in cancer stem cell (CSC) biology whether CSCs are by definition at the top of the differentiation hierarchy of the tumor. Wilms’ tumor (WT), composed of blastema and differentiated renal elements resembling the nephrogenic zone of the developing kidney, is a valuable model for studying this question because early kidney differentiation is well characterized. WT neural cell adhesion molecule 1-positive (NCAM1+) aldehyde dehydrogenase 1-positive (ALDH1+) CSCs have been recently isolated and shown to harbor early renal progenitor traits. Herein, by generating pure blastema WT xenografts, composed solely of cells expressing the renal developmental markers SIX2 and NCAM1, we surprisingly show that sorted ALDH1+ WT CSCs do not correspond to earliest renal stem cells. Rather, gene expression and proteomic comparative analyses disclose a cell type skewed more toward epithelial differentiation than the bulk of the blastema. Thus, WT CSCs are likely to dedifferentiate to propagate WT blastema. PMID:25068119

Dedifferentiated chondrosarcoma: an aggressive variant of chondrosarcoma.

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Bharath, Gangadhara; Burrah, Rajaram; Shivakumar, Kuppuswamy; Manjunath, Suraj; Bhanumathi, Rao

2015-02-01

Dedifferentiated chondrosarcomas are a rare and aggressive subtype of chondrosarcoma with a bimorphic pattern on histopathology. Rib is a rare site of dedifferentiated chondrosarcoma. Diagnosis of this subtype preoperatively can be challenging. Treatment options for dedifferentiated chondrosarcoma are limited because they are chemoresistant, and therefore adequate surgery forms the main stay of treatment. We present our experience with a dedifferentiated chondrosarcoma of the rib, and discuss the management of this rare entity. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Adult renal cell carcinoma with rhabdoid morphology represents a neoplastic dedifferentiation analogous to sarcomatoid carcinoma.

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Chapman-Fredricks, Jennifer R; Herrera, Loren; Bracho, Jorge; Gomez-Fernandez, Carmen; Leveillee, Raymond; Rey, Luis; Jorda, Merce

2011-10-01

Renal cell carcinoma (RCC) with rhabdoid morphology (RCC-RM) is a recently described variant of RCC, which has an aggressive biologic behavior and poor prognosis, akin to sarcomatoid RCC. The current World Health Organization classification of RCC does not include the rhabdoid phenotype as a distinct histologic entity. The aim of this study is to investigate whether RCC-RM represents a dedifferentiation of a classifiable-type World Health Organization RCC or a carcinosarcoma with muscle differentiation. We reviewed 168 cases of RCC obtained between 2003 and 2008. From these cases, 10 (6%) were found to have areas of classic rhabdoid morphology. Immunohistochemistry for cytokeratin, epithelial membrane antigen, desmin, CD10, and CD117 was performed in each case using the labeled streptavidin-biotin method. Rhabdoid differentiation was identified in association with conventional-type RCC (9) and with unclassifiable-type RCC with spindle cell morphology (1). In all cases, both the rhabdoid and nonrhabdoid tumoral areas were positive for cytokeratin and epithelial membrane antigen and negative for desmin. Cytokeratin positivity in the rhabdoid areas was focal. In cases associated with conventional-type RCC, CD10 was positive in both the rhabdoid and nonrhabdoid foci. CD117 was negative in these tumors. The unclassifiable-type RCC with spindle cell morphology was negative for both CD10 and CD117. The similar immunophenotype between the rhabdoid and nonrhabdoid tumoral foci supports the origin of the rhabdoid cells from the classifiable-type RCC. Areas of rhabdoid morphology do not represent muscle metaplastic differentiation. Renal cell carcinoma with rhabdoid morphology may represent a dedifferentiation of a classifiable-type RCC, similar to that of sarcomatoid differentiation. The recognition of RCC-RM is important as it allows for the inclusion of these high-grade malignancies into a category associated with poor prognosis despite lacking the spindle cell component

A case of dedifferentiated chondrosarcoma arising in the cricoid cartilage that mimicked an aneurysmal bone cyst.

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Chen, Lixiao; Yu, Ziwei; Jiang, Rui; Dong, Pin; Shen, Bin; Li, Yu

2018-03-01

Dedifferentiated chondrosarcoma of the larynx is a rare and highly malignant tumor. We present the report of a 59-year-old man with dedifferentiated laryngeal chondrosarcoma, which was difficult to diagnose even under microscopic examination. The original diagnosis was an aneurysmal bone cyst, and the final diagnosis was established only after careful consideration of the imaging, surgical, and microscopic findings. In clinical practice, there are many similarities between dedifferentiated chondrosarcoma and aneurysmal bone cysts. Furthermore, it is difficult to identify dedifferentiated laryngeal chondrosarcoma with a giant-cell malignant mesenchymal component. This report describes our experience and discusses this phenomenon.

Ectopic expression of Msx2 in mammalian myotubes recapitulates aspects of amphibian muscle dedifferentiation

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Atilgan Yilmaz

2015-11-01

Full Text Available In contrast to urodele amphibians and teleost fish, mammals lack the regenerative responses to replace large body parts. Amphibian and fish regeneration uses dedifferentiation, i.e., reversal of differentiated state, as a means to produce progenitor cells to eventually replace damaged tissues. Therefore, induced activation of dedifferentiation responses in mammalian tissues holds an immense promise for regenerative medicine. Here we demonstrate that ectopic expression of Msx2 in cultured mouse myotubes recapitulates several aspects of amphibian muscle dedifferentiation. We found that MSX2, but not MSX1, leads to cellularization of myotubes and downregulates the expression of myotube markers, such as MHC, MRF4 and myogenin. RNA sequencing of myotubes ectopically expressing Msx2 showed downregulation of over 500 myotube-enriched transcripts and upregulation of over 300 myoblast-enriched transcripts. MSX2 selectively downregulated expression of Ptgs2 and Ptger4, two members of the prostaglandin pathway with important roles in myoblast fusion during muscle differentiation. Ectopic expression of Msx2, as well as Msx1, induced partial cell cycle re-entry of myotubes by upregulating CyclinD1 expression but failed to initiate S-phase. Finally, MSX2-induced dedifferentiation in mouse myotubes could be recapitulated by a pharmacological treatment with trichostatin A (TSA, bone morphogenetic protein 4 (BMP4 and fibroblast growth factor 1 (FGF1. Together, these observations indicate that MSX2 is a major driver of dedifferentiation in mammalian muscle cells.

Glandular differentiation in dedifferentiated chondrosarcoma: molecular evidence of a rare phenomenon.

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Jour, George; Liu, Yajuan; Ricciotti, Robert; Pritchard, Colin; Hoch, Benjamin L

2015-09-01

Epithelial glandular differentiation in dedifferentiated chondrosarcoma has not been described. Our patient was a 64-year-old man with a history of prostate cancer status post-radiation and hormonal therapy. On screening bone scan, he was found to have increased uptake in his right femoral shaft. Biopsy revealed intermediate-grade conventional chondrosarcoma. Subsequent femoral resection was remarkable for an intermediate-grade chondrosarcomatous component juxtaposed to an area composed of anastomosing nests and cords of malignant epithelial cells showing nuclear atypia and increased mitotic activity. A fibroblastic-appearing spindle cell population was intimately associated with the epithelial cells. The epithelial cells labeled with 34bE12, AE1/AE3, EMA, and Vimentin (both spindled and epithelial components) while being negative for prostate-specific antigen, prostate specific acid phosphatase, cytokeratin 20, thyroid transcription factor-1, and CDX2. The patient developed local recurrence 9 months after the initial resection but has had no metastatic disease and consistently undetectable prostate-specific antigen levels. Deep parallel sequencing of the dedifferentiated component showed a nonsynonymous mutation at exon 4 of IDH1 gene at codon R132 leading to a substitution of arginine, with serine confirming glandular differentiation in dedifferentiated chondrosarcoma. Copyright © 2015 Elsevier Inc. All rights reserved.

Three new chondrosarcoma cell lines: one grade III conventional central chondrosarcoma and two dedifferentiated chondrosarcomas of bone

International Nuclear Information System (INIS)

Oosterwijk, Jolieke G van; Bovée, Judith VMG; Jong, Danielle de; Ruler, Maayke AJH van; Hogendoorn, Pancras CW; Dijkstra, PD Sander; Rijswijk, Carla SP van; Machado, Isidro; Llombart-Bosch, Antonio; Szuhai, Karoly

2012-01-01

Chondrosarcoma is the second most common primary sarcoma of bone. High-grade conventional chondrosarcoma and dedifferentiated chondrosarcoma have a poor outcome. In pre-clinical research aiming at the identification of novel treatment targets, the need for representative cell lines and model systems is high, but availability is scarce. We developed and characterized three cell lines, derived from conventional grade III chondrosarcoma (L835), and dedifferentiated chondrosarcoma (L2975 and L3252) of bone. Proliferation and migration were studied and we used COBRA-FISH and array-CGH for karyotyping and genotyping. Immunohistochemistry for p16 and p53 was performed as well as TP53 and IDH mutation analysis. Cells were injected into nude mice to establish their tumorigenic potential. We show that the three cell lines have distinct migrative properties, L2975 had the highest migration rate and showed tumorigenic potential in mice. All cell lines showed chromosomal rearrangements with complex karyotypes and genotypic aberrations were conserved throughout late passaging of the cell lines. All cell lines showed loss of CDKN2A, while TP53 was wild type for exons 5–8. L835 has an IDH1 R132C mutation, L2975 an IDH2 R172W mutation and L3252 is IDH wild type. Based on the stable culturing properties of these cell lines and their genotypic profile resembling the original tumors, these cell lines should provide useful functional models to further characterize chondrosarcoma and to evaluate new treatment strategies

ROCK inhibitor prevents the dedifferentiation of human articular chondrocytes

International Nuclear Information System (INIS)

Matsumoto, Emi; Furumatsu, Takayuki; Kanazawa, Tomoko; Tamura, Masanori; Ozaki, Toshifumi

2012-01-01

Highlights: ► ROCK inhibitor stimulates chondrogenic gene expression of articular chondrocytes. ► ROCK inhibitor prevents the dedifferentiation of monolayer-cultured chondrocytes. ► ROCK inhibitor enhances the redifferentiation of cultured chondrocytes. ► ROCK inhibitor is useful for preparation of un-dedifferentiated chondrocytes. ► ROCK inhibitor may be a useful reagent for chondrocyte-based regeneration therapy. -- Abstract: Chondrocytes lose their chondrocytic phenotypes in vitro. The Rho family GTPase ROCK, involved in organizing the actin cytoskeleton, modulates the differentiation status of chondrocytic cells. However, the optimum method to prepare a large number of un-dedifferentiated chondrocytes is still unclear. In this study, we investigated the effect of ROCK inhibitor (ROCKi) on the chondrogenic property of monolayer-cultured articular chondrocytes. Human articular chondrocytes were subcultured in the presence or absence of ROCKi (Y-27632). The expression of chondrocytic marker genes such as SOX9 and COL2A1 was assessed by quantitative real-time PCR analysis. Cellular morphology and viability were evaluated. Chondrogenic redifferentiation potential was examined by a pellet culture procedure. The expression level of SOX9 and COL2A1 was higher in ROCKi-treated chondrocytes than in untreated cells. Chondrocyte morphology varied from a spreading form to a round shape in a ROCKi-dependent manner. In addition, ROCKi treatment stimulated the proliferation of chondrocytes. The deposition of safranin O-stained proteoglycans and type II collagen was highly detected in chondrogenic pellets derived from ROCKi-pretreated chondrocytes. Our results suggest that ROCKi prevents the dedifferentiation of monolayer-cultured chondrocytes, and may be a useful reagent to maintain chondrocytic phenotypes in vitro for chondrocyte-based regeneration therapy.

Machine Learning Identifies Stemness Features Associated with Oncogenic Dedifferentiation

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Malta, Tathiane M.; Sokolov, Artem; Gentles, Andrew J.; Burzykowski, Tomasz; Poisson, Laila; Weinstein, John N.; Kamińska, Bożena; Huelsken, Joerg; Omberg, Larsson; Gevaert, Olivier; Colaprico, Antonio; Czerwińska, Patrycja; Mazurek, Sylwia; Mishra, Lopa; Heyn, Holger; Krasnitz, Alex; Godwin, Andrew K.; Lazar, Alexander J.; Caesar-Johnson, Samantha J.; Demchok, John A.; Felau, Ina; Kasapi, Melpomeni; Ferguson, Martin L.; Hutter, Carolyn M.; Sofia, Heidi J.; Tarnuzzer, Roy; Wang, Zhining; Yang, Liming; Zenklusen, Jean C.; Zhang, Jiashan (Julia); Chudamani, Sudha; Liu, Jia; Lolla, Laxmi; Naresh, Rashi; Pihl, Todd; Sun, Qiang; Wan, Yunhu; Wu, Ye; Cho, Juok; DeFreitas, Timothy; Frazer, Scott; Gehlenborg, Nils; Getz, Gad; Heiman, David I.; Kim, Jaegil; Lawrence, Michael S.; Lin, Pei; Meier, Sam; Noble, Michael S.; Saksena, Gordon; Voet, Doug; Zhang, Hailei; Bernard, Brady; Chambwe, Nyasha; Dhankani, Varsha; Knijnenburg, Theo; Kramer, Roger; Leinonen, Kalle; Liu, Yuexin; Miller, Michael; Reynolds, Sheila; Shmulevich, Ilya; Thorsson, Vesteinn; Zhang, Wei; Akbani, Rehan; Broom, Bradley M.; Hegde, Apurva M.; Ju, Zhenlin; Kanchi, Rupa S.; Korkut, Anil; Li, Jun; Liang, Han; Ling, Shiyun; Liu, Wenbin; Lu, Yiling; Mills, Gordon B.; Ng, Kwok Shing; Rao, Arvind; Ryan, Michael; Wang, Jing; Weinstein, John N.; Zhang, Jiexin; Abeshouse, Adam; Armenia, Joshua; Chakravarty, Debyani; Chatila, Walid K.; de Bruijn, Ino; Gao, Jianjiong; Gross, Benjamin E.; Heins, Zachary J.; Kundra, Ritika; La, Konnor; Ladanyi, Marc; Luna, Augustin; Nissan, Moriah G.; Ochoa, Angelica; Phillips, Sarah M.; Reznik, Ed; Sanchez-Vega, Francisco; Sander, Chris; Schultz, Nikolaus; Sheridan, Robert; Sumer, S. Onur; Sun, Yichao; Taylor, Barry S.; Wang, Jioajiao; Zhang, Hongxin; Anur, Pavana; Peto, Myron; Spellman, Paul; Benz, Christopher; Stuart, Joshua M.; Wong, Christopher K.; Yau, Christina; Hayes, D. Neil; Parker, Joel S.; Wilkerson, Matthew D.; Ally, Adrian; Balasundaram, Miruna; Bowlby, Reanne; Brooks, Denise; Carlsen, Rebecca; Chuah, Eric; Dhalla, Noreen; Holt, Robert; Jones, Steven J.M.; Kasaian, Katayoon; Lee, Darlene; Ma, Yussanne; Marra, Marco A.; Mayo, Michael; Moore, Richard A.; Mungall, Andrew J.; Mungall, Karen; Robertson, A. Gordon; Sadeghi, Sara; Schein, Jacqueline E.; Sipahimalani, Payal; Tam, Angela; Thiessen, Nina; Tse, Kane; Wong, Tina; Berger, Ashton C.; Beroukhim, Rameen; Cherniack, Andrew D.; Cibulskis, Carrie; Gabriel, Stacey B.; Gao, Galen F.; Ha, Gavin; Meyerson, Matthew; Schumacher, Steven E.; Shih, Juliann; Kucherlapati, Melanie H.; Kucherlapati, Raju S.; Baylin, Stephen; Cope, Leslie; Danilova, Ludmila; Bootwalla, Moiz S.; Lai, Phillip H.; Maglinte, Dennis T.; Van Den Berg, David J.; Weisenberger, Daniel J.; Auman, J. Todd; Balu, Saianand; Bodenheimer, Tom; Fan, Cheng; Hoadley, Katherine A.; Hoyle, Alan P.; Jefferys, Stuart R.; Jones, Corbin D.; Meng, Shaowu; Mieczkowski, Piotr A.; Mose, Lisle E.; Perou, Amy H.; Perou, Charles M.; Roach, Jeffrey; Shi, Yan; Simons, Janae V.; Skelly, Tara; Soloway, Matthew G.; Tan, Donghui; Veluvolu, Umadevi; Fan, Huihui; Hinoue, Toshinori; Laird, Peter W.; Shen, Hui; Zhou, Wanding; Bellair, Michelle; Chang, Kyle; Covington, Kyle; Creighton, Chad J.; Dinh, Huyen; Doddapaneni, Harsha Vardhan; Donehower, Lawrence A.; Drummond, Jennifer; Gibbs, Richard A.; Glenn, Robert; Hale, Walker; Han, Yi; Hu, Jianhong; Korchina, Viktoriya; Lee, Sandra; Lewis, Lora; Li, Wei; Liu, Xiuping; Morgan, Margaret; Morton, Donna; Muzny, Donna; Santibanez, Jireh; Sheth, Margi; Shinbrot, Eve; Wang, Linghua; Wang, Min; Wheeler, David A.; Xi, Liu; Zhao, Fengmei; Hess, Julian; Appelbaum, Elizabeth L.; Bailey, Matthew; Cordes, Matthew G.; Ding, Li; Fronick, Catrina C.; Fulton, Lucinda A.; Fulton, Robert S.; Kandoth, Cyriac; Mardis, Elaine R.; McLellan, Michael D.; Miller, Christopher A.; Schmidt, Heather K.; Wilson, Richard K.; Crain, Daniel; Curley, Erin; Gardner, Johanna; Lau, Kevin; Mallery, David; Morris, Scott; Paulauskis, Joseph; Penny, Robert; Shelton, Candace; Shelton, Troy; Sherman, Mark; Thompson, Eric; Yena, Peggy; Bowen, Jay; Gastier-Foster, Julie M.; Gerken, Mark; Leraas, Kristen M.; Lichtenberg, Tara M.; Ramirez, Nilsa C.; Wise, Lisa; Zmuda, Erik; Corcoran, Niall; Costello, Tony; Hovens, Christopher; Carvalho, Andre L.; de Carvalho, Ana C.; Fregnani, José H.; Longatto-Filho, Adhemar; Reis, Rui M.; Scapulatempo-Neto, Cristovam; Silveira, Henrique C.S.; Vidal, Daniel O.; Burnette, Andrew; Eschbacher, Jennifer; Hermes, Beth; Noss, Ardene; Singh, Rosy; Anderson, Matthew L.; Castro, Patricia D.; Ittmann, Michael; Huntsman, David; Kohl, Bernard; Le, Xuan; Thorp, Richard; Andry, Chris; Duffy, Elizabeth R.; Lyadov, Vladimir; Paklina, Oxana; Setdikova, Galiya; Shabunin, Alexey; Tavobilov, Mikhail; McPherson, Christopher; Warnick, Ronald; Berkowitz, Ross; Cramer, Daniel; Feltmate, Colleen; Horowitz, Neil; Kibel, Adam; Muto, Michael; Raut, Chandrajit P.; Malykh, Andrei; Barnholtz-Sloan, Jill S.; Barrett, Wendi; Devine, Karen; Fulop, Jordonna; Ostrom, Quinn T.; Shimmel, Kristen; Wolinsky, Yingli; Sloan, Andrew E.; De Rose, Agostino; Giuliante, Felice; Goodman, Marc; Karlan, Beth Y.; Hagedorn, Curt H.; Eckman, John; Harr, Jodi; Myers, Jerome; Tucker, Kelinda; Zach, Leigh Anne; Deyarmin, Brenda; Hu, Hai; Kvecher, Leonid; Larson, Caroline; Mural, Richard J.; Somiari, Stella; Vicha, Ales; Zelinka, Tomas; Bennett, Joseph; Iacocca, Mary; Rabeno, Brenda; Swanson, Patricia; Latour, Mathieu; Lacombe, Louis; Têtu, Bernard; Bergeron, Alain; McGraw, Mary; Staugaitis, Susan M.; Chabot, John; Hibshoosh, Hanina; Sepulveda, Antonia; Su, Tao; Wang, Timothy; Potapova, Olga; Voronina, Olga; Desjardins, Laurence; Mariani, Odette; Roman-Roman, Sergio; Sastre, Xavier; Stern, Marc Henri; Cheng, Feixiong; Signoretti, Sabina; Berchuck, Andrew; Bigner, Darell; Lipp, Eric; Marks, Jeffrey; McCall, Shannon; McLendon, Roger; Secord, Angeles; Sharp, Alexis; Behera, Madhusmita; Brat, Daniel J.; Chen, Amy; Delman, Keith; Force, Seth; Khuri, Fadlo; Magliocca, Kelly; Maithel, Shishir; Olson, Jeffrey J.; Owonikoko, Taofeek; Pickens, Alan; Ramalingam, Suresh; Shin, Dong M.; Sica, Gabriel; Van Meir, Erwin G.; Zhang, Hongzheng; Eijckenboom, Wil; Gillis, Ad; Korpershoek, Esther; Looijenga, Leendert; Oosterhuis, Wolter; Stoop, Hans; van Kessel, Kim E.; Zwarthoff, Ellen C.; Calatozzolo, Chiara; Cuppini, Lucia; Cuzzubbo, Stefania; DiMeco, Francesco; Finocchiaro, Gaetano; Mattei, Luca; Perin, Alessandro; Pollo, Bianca; Chen, Chu; Houck, John; Lohavanichbutr, Pawadee; Hartmann, Arndt; Stoehr, Christine; Stoehr, Robert; Taubert, Helge; Wach, Sven; Wullich, Bernd; Kycler, Witold; Murawa, Dawid; Wiznerowicz, Maciej; Chung, Ki; Edenfield, W. Jeffrey; Martin, Julie; Baudin, Eric; Bubley, Glenn; Bueno, Raphael; De Rienzo, Assunta; Richards, William G.; Kalkanis, Steven; Mikkelsen, Tom; Noushmehr, Houtan; Scarpace, Lisa; Girard, Nicolas; Aymerich, Marta; Campo, Elias; Giné, Eva; Guillermo, Armando López; Van Bang, Nguyen; Hanh, Phan Thi; Phu, Bui Duc; Tang, Yufang; Colman, Howard; Evason, Kimberley; Dottino, Peter R.; Martignetti, John A.; Gabra, Hani; Juhl, Hartmut; Akeredolu, Teniola; Stepa, Serghei; Hoon, Dave; Ahn, Keunsoo; Kang, Koo Jeong; Beuschlein, Felix; Breggia, Anne; Birrer, Michael; Bell, Debra; Borad, Mitesh; Bryce, Alan H.; Castle, Erik; Chandan, Vishal; Cheville, John; Copland, John A.; Farnell, Michael; Flotte, Thomas; Giama, Nasra; Ho, Thai; Kendrick, Michael; Kocher, Jean Pierre; Kopp, Karla; Moser, Catherine; Nagorney, David; O'Brien, Daniel; O'Neill, Brian Patrick; Patel, Tushar; Petersen, Gloria; Que, Florencia; Rivera, Michael; Roberts, Lewis; Smallridge, Robert; Smyrk, Thomas; Stanton, Melissa; Thompson, R. Houston; Torbenson, Michael; Yang, Ju Dong; Zhang, Lizhi; Brimo, Fadi; Ajani, Jaffer A.; Gonzalez, Ana Maria Angulo; Behrens, Carmen; Bondaruk, Jolanta; Broaddus, Russell; Czerniak, Bogdan; Esmaeli, Bita; Fujimoto, Junya; Gershenwald, Jeffrey; Guo, Charles; Lazar, Alexander J.; Logothetis, Christopher; Meric-Bernstam, Funda; Moran, Cesar; Ramondetta, Lois; Rice, David; Sood, Anil; Tamboli, Pheroze; Thompson, Timothy; Troncoso, Patricia; Tsao, Anne; Wistuba, Ignacio; Carter, Candace; Haydu, Lauren; Hersey, Peter; Jakrot, Valerie; Kakavand, Hojabr; Kefford, Richard; Lee, Kenneth; Long, Georgina; Mann, Graham; Quinn, Michael; Saw, Robyn; Scolyer, Richard; Shannon, Kerwin; Spillane, Andrew; Stretch, Jonathan; Synott, Maria; Thompson, John; Wilmott, James; Al-Ahmadie, Hikmat; Chan, Timothy A.; Ghossein, Ronald; Gopalan, Anuradha; Levine, Douglas A.; Reuter, Victor; Singer, Samuel; Singh, Bhuvanesh; Tien, Nguyen Viet; Broudy, Thomas; Mirsaidi, Cyrus; Nair, Praveen; Drwiega, Paul; Miller, Judy; Smith, Jennifer; Zaren, Howard; Park, Joong Won; Hung, Nguyen Phi; Kebebew, Electron; Linehan, W. Marston; Metwalli, Adam R.; Pacak, Karel; Pinto, Peter A.; Schiffman, Mark; Schmidt, Laura S.; Vocke, Cathy D.; Wentzensen, Nicolas; Worrell, Robert; Yang, Hannah; Moncrieff, Marc; Goparaju, Chandra; Melamed, Jonathan; Pass, Harvey; Botnariuc, Natalia; Caraman, Irina; Cernat, Mircea; Chemencedji, Inga; Clipca, Adrian; Doruc, Serghei; Gorincioi, Ghenadie; Mura, Sergiu; Pirtac, Maria; Stancul, Irina; Tcaciuc, Diana; Albert, Monique; Alexopoulou, Iakovina; Arnaout, Angel; Bartlett, John; Engel, Jay; Gilbert, Sebastien; Parfitt, Jeremy; Sekhon, Harman; Thomas, George; Rassl, Doris M.; Rintoul, Robert C.; Bifulco, Carlo; Tamakawa, Raina; Urba, Walter; Hayward, Nicholas; Timmers, Henri; Antenucci, Anna; Facciolo, Francesco; Grazi, Gianluca; Marino, Mirella; Merola, Roberta; de Krijger, Ronald; Gimenez-Roqueplo, Anne Paule; Piché, Alain; Chevalier, Simone; McKercher, Ginette; Birsoy, Kivanc; Barnett, Gene; Brewer, Cathy; Farver, Carol; Naska, Theresa; Pennell, Nathan A.; Raymond, Daniel; Schilero, Cathy; Smolenski, Kathy; Williams, Felicia; Morrison, Carl; Borgia, Jeffrey A.; Liptay, Michael J.; Pool, Mark; Seder, Christopher W.; Junker, Kerstin; Omberg, Larsson; Dinkin, Mikhail; Manikhas, George; Alvaro, Domenico; Bragazzi, Maria Consiglia; Cardinale, Vincenzo; Carpino, Guido; Gaudio, Eugenio; Chesla, David; Cottingham, Sandra; Dubina, Michael; Moiseenko, Fedor; Dhanasekaran, Renumathy; Becker, Karl Friedrich; Janssen, Klaus Peter; Slotta-Huspenina, Julia; Abdel-Rahman, Mohamed H.; Aziz, Dina; Bell, Sue; Cebulla, Colleen M.; Davis, Amy; Duell, Rebecca; Elder, J. Bradley; Hilty, Joe; Kumar, Bahavna; Lang, James; Lehman, Norman L.; Mandt, Randy; Nguyen, Phuong; Pilarski, Robert; Rai, Karan; Schoenfield, Lynn; Senecal, Kelly; Wakely, Paul; Hansen, Paul; Lechan, Ronald; Powers, James; Tischler, Arthur; Grizzle, William E.; Sexton, Katherine C.; Kastl, Alison; Henderson, Joel; Porten, Sima; Waldmann, Jens; Fassnacht, Martin; Asa, Sylvia L.; Schadendorf, Dirk; Couce, Marta; Graefen, Markus; Huland, Hartwig; Sauter, Guido; Schlomm, Thorsten; Simon, Ronald; Tennstedt, Pierre; Olabode, Oluwole; Nelson, Mark; Bathe, Oliver; Carroll, Peter R.; Chan, June M.; Disaia, Philip; Glenn, Pat; Kelley, Robin K.; Landen, Charles N.; Phillips, Joanna; Prados, Michael; Simko, Jeffry; Smith-McCune, Karen; VandenBerg, Scott; Roggin, Kevin; Fehrenbach, Ashley; Kendler, Ady; Sifri, Suzanne; Steele, Ruth; Jimeno, Antonio; Carey, Francis; Forgie, Ian; Mannelli, Massimo; Carney, Michael; Hernandez, Brenda; Campos, Benito; Herold-Mende, Christel; Jungk, Christin; Unterberg, Andreas; von Deimling, Andreas; Bossler, Aaron; Galbraith, Joseph; Jacobus, Laura; Knudson, Michael; Knutson, Tina; Ma, Deqin; Milhem, Mohammed; Sigmund, Rita; Godwin, Andrew K.; Madan, Rashna; Rosenthal, Howard G.; Adebamowo, Clement; Adebamowo, Sally N.; Boussioutas, Alex; Beer, David; Giordano, Thomas; Mes-Masson, Anne Marie; Saad, Fred; Bocklage, Therese; Landrum, Lisa; Mannel, Robert; Moore, Kathleen; Moxley, Katherine; Postier, Russel; Walker, Joan; Zuna, Rosemary; Feldman, Michael; Valdivieso, Federico; Dhir, Rajiv; Luketich, James; Pinero, Edna M.Mora; Quintero-Aguilo, Mario; Carlotti, Carlos Gilberto; Dos Santos, Jose Sebastião; Kemp, Rafael; Sankarankuty, Ajith; Tirapelli, Daniela; Catto, James; Agnew, Kathy; Swisher, Elizabeth; Creaney, Jenette; Robinson, Bruce; Shelley, Carl Simon; Godwin, Eryn M.; Kendall, Sara; Shipman, Cassaundra; Bradford, Carol; Carey, Thomas; Haddad, Andrea; Moyer, Jeffey; Peterson, Lisa; Prince, Mark; Rozek, Laura; Wolf, Gregory; Bowman, Rayleen; Fong, Kwun M.; Yang, Ian; Korst, Robert; Rathmell, W. Kimryn; Fantacone-Campbell, J. Leigh; Hooke, Jeffrey A.; Kovatich, Albert J.; Shriver, Craig D.; DiPersio, John; Drake, Bettina; Govindan, Ramaswamy; Heath, Sharon; Ley, Timothy; Van Tine, Brian; Westervelt, Peter; Rubin, Mark A.; Lee, Jung Il; Aredes, Natália D.; Mariamidze, Armaz; Stuart, Joshua M.; Hoadley, Katherine A.; Laird, Peter W.; Noushmehr, Houtan; Wiznerowicz, Maciej

2018-01-01

Cancer progression involves the gradual loss of a differentiated phenotype and acquisition of progenitor and stem-cell-like features. Here, we provide novel stemness indices for assessing the degree of oncogenic dedifferentiation. We used an innovative one-class logistic regression (OCLR)

ROCK inhibitor prevents the dedifferentiation of human articular chondrocytes

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Matsumoto, Emi [Department of Orthopaedic Surgery, Science of Functional Recovery and Reconstruction, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikatacho, Kitaku, Okayama 700-8558 (Japan); Furumatsu, Takayuki, E-mail: matino@md.okayama-u.ac.jp [Department of Orthopaedic Surgery, Science of Functional Recovery and Reconstruction, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikatacho, Kitaku, Okayama 700-8558 (Japan); Kanazawa, Tomoko; Tamura, Masanori; Ozaki, Toshifumi [Department of Orthopaedic Surgery, Science of Functional Recovery and Reconstruction, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, 2-5-1 Shikatacho, Kitaku, Okayama 700-8558 (Japan)

2012-03-30

Highlights: Black-Right-Pointing-Pointer ROCK inhibitor stimulates chondrogenic gene expression of articular chondrocytes. Black-Right-Pointing-Pointer ROCK inhibitor prevents the dedifferentiation of monolayer-cultured chondrocytes. Black-Right-Pointing-Pointer ROCK inhibitor enhances the redifferentiation of cultured chondrocytes. Black-Right-Pointing-Pointer ROCK inhibitor is useful for preparation of un-dedifferentiated chondrocytes. Black-Right-Pointing-Pointer ROCK inhibitor may be a useful reagent for chondrocyte-based regeneration therapy. -- Abstract: Chondrocytes lose their chondrocytic phenotypes in vitro. The Rho family GTPase ROCK, involved in organizing the actin cytoskeleton, modulates the differentiation status of chondrocytic cells. However, the optimum method to prepare a large number of un-dedifferentiated chondrocytes is still unclear. In this study, we investigated the effect of ROCK inhibitor (ROCKi) on the chondrogenic property of monolayer-cultured articular chondrocytes. Human articular chondrocytes were subcultured in the presence or absence of ROCKi (Y-27632). The expression of chondrocytic marker genes such as SOX9 and COL2A1 was assessed by quantitative real-time PCR analysis. Cellular morphology and viability were evaluated. Chondrogenic redifferentiation potential was examined by a pellet culture procedure. The expression level of SOX9 and COL2A1 was higher in ROCKi-treated chondrocytes than in untreated cells. Chondrocyte morphology varied from a spreading form to a round shape in a ROCKi-dependent manner. In addition, ROCKi treatment stimulated the proliferation of chondrocytes. The deposition of safranin O-stained proteoglycans and type II collagen was highly detected in chondrogenic pellets derived from ROCKi-pretreated chondrocytes. Our results suggest that ROCKi prevents the dedifferentiation of monolayer-cultured chondrocytes, and may be a useful reagent to maintain chondrocytic phenotypes in vitro for chondrocyte

Three new chondrosarcoma cell lines: one grade III conventional central chondrosarcoma and two dedifferentiated chondrosarcomas of bone

Science.gov (United States)

2012-01-01

Background Chondrosarcoma is the second most common primary sarcoma of bone. High-grade conventional chondrosarcoma and dedifferentiated chondrosarcoma have a poor outcome. In pre-clinical research aiming at the identification of novel treatment targets, the need for representative cell lines and model systems is high, but availability is scarce. Methods We developed and characterized three cell lines, derived from conventional grade III chondrosarcoma (L835), and dedifferentiated chondrosarcoma (L2975 and L3252) of bone. Proliferation and migration were studied and we used COBRA-FISH and array-CGH for karyotyping and genotyping. Immunohistochemistry for p16 and p53 was performed as well as TP53 and IDH mutation analysis. Cells were injected into nude mice to establish their tumorigenic potential. Results We show that the three cell lines have distinct migrative properties, L2975 had the highest migration rate and showed tumorigenic potential in mice. All cell lines showed chromosomal rearrangements with complex karyotypes and genotypic aberrations were conserved throughout late passaging of the cell lines. All cell lines showed loss of CDKN2A, while TP53 was wild type for exons 5–8. L835 has an IDH1 R132C mutation, L2975 an IDH2 R172W mutation and L3252 is IDH wild type. Conclusions Based on the stable culturing properties of these cell lines and their genotypic profile resembling the original tumors, these cell lines should provide useful functional models to further characterize chondrosarcoma and to evaluate new treatment strategies. PMID:22928481

β-Cell dedifferentiation, reduced duct cell plasticity, and impaired β-cell mass regeneration in middle-aged rats.

Science.gov (United States)

Téllez, Noèlia; Vilaseca, Marina; Martí, Yasmina; Pla, Arturo; Montanya, Eduard

2016-09-01

Limitations in β-cell regeneration potential in middle-aged animals could contribute to the increased risk to develop diabetes associated with aging. We investigated β-cell regeneration of middle-aged Wistar rats in response to two different regenerative stimuli: partial pancreatectomy (Px + V) and gastrin administration (Px + G). Pancreatic remnants were analyzed 3 and 14 days after surgery. β-Cell mass increased in young animals after Px and was further increased after gastrin treatment. In contrast, β-cell mass did not change after Px or after gastrin treatment in middle-aged rats. β-Cell replication and individual β-cell size were similarly increased after Px in young and middle-aged animals, and β-cell apoptosis was not modified. Nuclear immunolocalization of neurog3 or nkx6.1 in regenerative duct cells, markers of duct cell plasticity, was increased in young but not in middle-aged Px rats. The pancreatic progenitor-associated transcription factors neurog3 and sox9 were upregulated in islet β-cells of middle-aged rats and further increased after Px. The percentage of chromogranin A+/hormone islet cells was significantly increased in the pancreases of middle-aged Px rats. In summary, the potential for compensatory β-cell hyperplasia and hypertrophy was retained in middle-aged rats, but β-cell dedifferentiation and impaired duct cell plasticity limited β-cell regeneration. Copyright © 2016 the American Physiological Society.

Autophagic dedifferentiation induced by cooperation between TOR inhibitor and retinoic acid signals in budding tunicates.

Science.gov (United States)

Kawamura, Kaz; Yoshida, Takuto; Sekida, Satoko

2018-01-15

Asexual bud development in the budding tunicate Polyandrocarpa misakiensis involves transdifferentiation of multipotent epithelial cells, which is triggered by retinoic acid (RA), and thrives under starvation after bud isolation from the parent. This study aimed to determine cell and molecular mechanisms of dedifferentiation that occur during the early stage of transdifferentiation. During dedifferentiation, the numbers of autophagosomes, lysosomes, and secondary lysosomes increased remarkably. Mitochondrial degradation and exosome discharge also occurred in the atrial epithelium. Autophagy-related gene 7 (Atg7) and lysosomal proton pump A gene (PumpA) were activated during the dedifferentiation stage. When target of rapamycin (TOR) inhibitor was administered to growing buds without isolating them from the parent, phagosomes and secondary lysosomes became prominent. TOR inhibitor induced Atg7 only in the presence of RA. In contrast, when growing buds were treated with RA, lysosomes, secondary lysosomes, and mitochondrial degradation were prematurely induced. RA significantly activated PumpA in a retinoid X receptor-dependent manner. Our results indicate that in P. misakiensis, TOR inhibition and RA signals act in synergy to accomplish cytoplasmic clearance for dedifferentiation. Copyright © 2017 Elsevier Inc. All rights reserved.

Distribution of linker histone variants during plant cell differentiation in the developmental zones of the maize root, dedifferentiation in callus culture after auxin treatment

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ANASTASIOS ALATZAS

2008-01-01

Full Text Available Although several linker histone variants have been studied in both animal and plant organisms, little is known about their distribution during processes that involve alterations in chromatin function, such as differentiation, dedifferentiation and hormone treatment. In this study, we identified linker histone variants by using specific anti-histone Hl antibodies. Each variant's ratio to total Hl in the three developmental zones of maize (Zea mays L. root and in callus cultures derived from them was estimated in order to define possible alterations either during plant cell differentiation or during their dedifferentiation. We also evaluated linker histone variants' ratios in the developmental zones of maize roots treated with auxin in order to examine the effects of exogenous applied auxin to linker histone variant distribution. Finally, immunohistochemical detection was used to identify the root tissues containing each variant and correlate them with the physiological status of the plant cells. According to the results presented in this study, linker histone variants' ratios are altered in the developmental zones of maize root, while they are similar to the meristematic zone in samples from callus cultures and to the differentiation zone in samples from roots treated with auxin. We propose that the alterations in linker histone variants' ratios are correlated with plant cell differentiation and dedifferentiation.

Dedifferentiated chondrosarcoma with leukocytosis and elevation of serum G-CSF. A case report

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Oda Yoshinao

2006-07-01

Full Text Available Abstract Background G-CSF is known to function as a hematopoietic growth factor and it is known to be responsible for leukocytosis. G-CSF-producing tumors associated with leukocytosis include various types of malignancies. Case presentation We report the case of a 72-year-old man with dedifferentiated chondrosarcoma characterized by dedifferentiated components of malignant fibrous histiocytoma- or osteosarcoma-like features in addition to conventional chondrosarcoma, arising from his pelvic bone. After hemipelvectomy, when local recurrence and metastasis were identified, leukocytosis appeared and an elevated level of serum granulocyte-colony-stimulating factor (G-CSF was also recognized. The patient died of multiple organ failure 2 months after surgery. Autopsy specimens showed that the histological specimens of the recurrence and metastasis were dedifferentiated components, without any conventional chondrosarcoma components. G-CSF was expressed only in the dedifferentiated components, not in the chondrosarcoma components, immunohistochemically. Conclusion This is the first report of chondrosarcoma, or any other primary bone tumor, with leukocytosis, probably stimulated by tumor-produced G-CSF from the dedifferentiated components.

Fine needle aspiration biopsy diagnosis of dedifferentiated liposarcoma: Cytomorphology and MDM2 amplification by FISH

Directory of Open Access Journals (Sweden)

Al-Maghraby Hatem

2010-01-01

Full Text Available Lipomatous mesenchymal tumors constitute the most common type of soft tissue tumors. Well-differentiated liposarcoma (WDLS can undergo dedifferentiation to a nonlipogenic sarcoma of variable histologic grade. In the recent literature, amplification of the murine double minute 2 (MDM2 oncogene, which has a role in cell cycle control, has been successful in distinguishing WDLS from benign lesions. We present a case of dedifferentiated liposarcoma diagnosed by fine-needle aspiration (FNA, using cytomorphology and ancillary studies (immunocytochemistry and fluorescent in-situ hybridization. An 85-year old female presented to our institution with a firm soft tissue mass of the right buttock. The FNA showed atypical spindle cells, osteoclast-like giant cells and extracellular dense matrix material. The cell block showed cellular groups of highly atypical spindle cells with osteoid and adipose tissue. Fluorescence in situ hybridization (FISH studies performed on the cell block demonstrated amplification of the MDM2 gene. In addition, the findings were morphologically compatible with the previously resected retroperitoneal dedifferentiated liposarcoma with areas of osteosarcoma. This rare case illustrates the usefulness of FNA and ancillary studies in the diagnosis and subclassification of soft tissue tumors. To the best of our knowledge, this is the first report of MDM2 FISH positivity in a liposarcoma diagnosed by FNA.

Dedifferentiated liposarcoma of the anterior mediastinum. A rare case

International Nuclear Information System (INIS)

Harth, S.; Litzlbauer, H.D.; Behrens, C.B.; Roller, F.C.; Gamerdinger, U.; Burchert, D.; Krombach, G.A.

2016-01-01

Liposarcoma accounts for approximately 14 % of all malignant soft-tissue tumors, regardless of anatomical location (Kransdorf MJ et al. Imaging of soft tissue tumors. Philadelphia: Lippincott Williams and Wilkins, 2014). Primary mediastinal liposarcomas are rare. Liposarcoma is classified into four histologic subtypes: Myxoid/round cell, pleomorphic, atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma. Dedifferentiated liposarcoma occurs most commonly in the retroperitoneum and in the soft tissues of the extremities. Like atypical lipomatous tumor/well-differentiated liposarcoma, it is characterized by amplification of MDM2 and CDK4 genes on chromosome 12 (Crago AM et al. Curr Opin Oncol 2011; 23: 373 - 378). Possible symptoms of mediastinal liposarcoma are dyspnea, wheezing, chest pain, cough, superior vena cava syndrome, and weight loss (Macchiarini P et al. Lancet Oncol 2004; 5: 107 - 118).

Dedifferentiated liposarcoma of the anterior mediastinum. A rare case

Energy Technology Data Exchange (ETDEWEB)

Harth, S.; Litzlbauer, H.D.; Behrens, C.B.; Roller, F.C.; Gamerdinger, U.; Burchert, D.; Krombach, G.A.

2016-01-15

Liposarcoma accounts for approximately 14 % of all malignant soft-tissue tumors, regardless of anatomical location (Kransdorf MJ et al. Imaging of soft tissue tumors. Philadelphia: Lippincott Williams and Wilkins, 2014). Primary mediastinal liposarcomas are rare. Liposarcoma is classified into four histologic subtypes: Myxoid/round cell, pleomorphic, atypical lipomatous tumor/well-differentiated liposarcoma and dedifferentiated liposarcoma. Dedifferentiated liposarcoma occurs most commonly in the retroperitoneum and in the soft tissues of the extremities. Like atypical lipomatous tumor/well-differentiated liposarcoma, it is characterized by amplification of MDM2 and CDK4 genes on chromosome 12 (Crago AM et al. Curr Opin Oncol 2011; 23: 373 - 378). Possible symptoms of mediastinal liposarcoma are dyspnea, wheezing, chest pain, cough, superior vena cava syndrome, and weight loss (Macchiarini P et al. Lancet Oncol 2004; 5: 107 - 118).

Case report 461: Dedifferentiated parosteal osteosarcoma

Energy Technology Data Exchange (ETDEWEB)

Sauer, D.D.; Chase, D.R.

1988-01-01

A case of parosteal osteosarcoma has been presented. The lesion initially appeared aggressive on the radiographs but very indolent pathologically. The progressive increase in anaplasia, cellularity and aggressive behavior of the tumor reflects dedifferentiation from a pathologically indolent lesion to a high grade sarcoma with metastatic potential. The rapid progression and demise of the patient, once dedifferentiation occurred, stress the need for correct diagnosis and appropriate therapy at the time the patient presents initially. (orig.)

Diagnostic utility of IDH1/2 mutations to distinguish dedifferentiated chondrosarcoma from undifferentiated pleomorphic sarcoma of bone.

Science.gov (United States)

Chen, Shaoxiong; Fritchie, Karen; Wei, Shi; Ali, Naser; Curless, Kendra; Shen, Tiansheng; Brini, Anna T; Latif, Farida; Sumathi, Vaiyapuri; Siegal, Gene P; Cheng, Liang

2017-07-01

Histologically, it is nearly impossible to distinguish the dedifferentiated component of dedifferentiated chondrosarcoma from undifferentiated pleomorphic sarcoma (UPS) of bone when the low-grade cartilaginous component is absent. Previous studies have revealed that isocitrate dehydrogenase 1 (IDH1) and IDH2 mutations are present in a significant number of cartilaginous tumors including most conventional chondrosarcomas and dedifferentiated chondrosarcomas. These mutations have not been studied in UPSs of bone. We sought to investigate whether an IDH1 or IDH2 mutation signature could be used as a clinically diagnostic marker for the distinction of dedifferentiated component of chondrosarcoma from UPS of bone. Sixty-eight bone tumor cases, including 31 conventional chondrosarcomas, 23 dedifferentiated chondrosarcomas, and 14 UPSs of bone, were collected for IDH1/2 mutation analysis either using the Qiagen IDH1/2 RGQ PCR Kit or using whole-exome sequencing. IDH1/2 mutations were detected in 87% (20/23) of dedifferentiated chondrosarcomas and 30% (6/20) of conventional chondrosarcomas. No mutations were detected in the IDH1/2 codon 132 or codon 172 among 14 UPSs of bone. Identification of IDH1 or IDH2 mutations supports the diagnosis of dedifferentiated chondrosarcoma rather than UPS of bone while also providing some insight into the pathogenesis of these 2 lesions. Copyright © 2017 Elsevier Inc. All rights reserved.

Dedifferentiated chondrosarcoma in childhood: report of a case

International Nuclear Information System (INIS)

Herman, T.E.; McAlister, W.H.; Dehner, L.P.; Kaufman, B.A.

1995-01-01

Dedifferentiated chondrosarcoma is an unconventional chondrosarcoma of distinctive pathology. The tumor, not previously reported in childhood, is characterized by a very poor prognosis with an average survival of only 6 months. Imaging features include a lytic lesion, focal calcifications, and a soft tissue mass. (orig.)

Screening for potential targets for therapy in mesenchymal, clear cell, and dedifferentiated chondrosarcoma reveals Bcl-2 family members and TGFβ as potential targets

DEFF Research Database (Denmark)

van Oosterwijk, Jolieke G; Meijer, Danielle; van Ruler, Maayke A J H

2013-01-01

. As in conventional chondrosarcoma, antiapoptotic proteins (Bcl-2, and/or Bcl-xl) were highly expressed in all subtypes. Inhibition with the BH-3 mimetic ABT-737 rendered dedifferentiated chondrosarcoma cell lines sensitive to doxorubicin or cisplatin. Our data indicate that antiapoptotic proteins may play...

Dickkopf-3 maintains the PANC-1 human pancreatic tumor cells in a dedifferentiated state.

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Zenzmaier, Christoph; Hermann, Martin; Hengster, Paul; Berger, Peter

2012-01-01

Pancreatic cancer (PaCa) is the fourth leading cause of cancer deaths in Western societies, with pancreatic ductal adenocarcinomas (PDACs) accounting for >90% of such cases. PDAC is a heterogeneous disease that includes a subset showing overexpression of the secreted glycoprotein Dickkopf-related protein 3 (Dkk-3), a protein shown to be downregulated in various cancers of different tissues. The biological function of Dkk-3 in this subset was studied using the Dkk-3 expressing PANC-1 cell line as a model for PDACs. The influence of Dkk-3 overexpression and knockdown on cellular differentiation and proliferation of PANC-1 was investigated. Confocal microscopy showed that Dkk-3 was expressed in a fraction of PANC-1 cells. While lentiviral-mediated overexpression of DKK3 did not alter cellular proliferation, knockdown of DKK3 resulted in significant reduction of cellular proliferation and concomitant induction of cell cycle inhibitors CDKN2B (p15INK4b), CDKN1A (p21CIP1) and CDKN1B (p27KIP1). In parallel, pancreatic epithelial cell differentiation markers AMY2A, CELA1, CTRB1, GCG, GLB1 and INS were significantly upregulated. PANC-1 cells differentiated using exendin-4 showed analogous induction of cell cycle inhibitors and differentiation markers. Thus, we conclude that Dkk-3 is required to maintain a highly dedifferentiated and consequently proliferative state in PANC-1, indicating a similar function in the Dkk-3 overexpressing subset of PDACs. Therefore, Dkk-3 represents a potential target for the treatment of Dkk-3-positive subtypes of PaCa to drive cells into cell cycle arrest and differentiation.

Dedifferentiated Leiomyosarcoma of the Uterus with Heterologous Elements: A Potential Diagnostic Pitfall

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Kojo R. Rawish

2012-01-01

Full Text Available Dedifferentiation is a phenomenon that is well characterized in a variety of tumors and is defined by the occurrence of a high-grade or undifferentiated tumor, typically unrecognizable regarding its line of differentiation, from a low-grade/borderline neoplasm. This phenomenon has previously been described in 2 uterine leiomyosarcomas, but both were devoid of heterologous elements. The authors describe herein a case of a dedifferentiated leiomyosarcoma of the uterus with osteoid heterologous elements, believed to be the first such reported case. The original tumor was a high-grade leiomyosarcoma with large low-grade and leiomyoma-like areas and whose constituent cells displayed intense nuclear immunoreactivity for both estrogen receptor (ER and progesterone receptor (PR in approximately 30% of cells. The tumor recurred six months after its resection as an undifferentiated sarcoma that was negative for smooth muscle markers, but which remained positive for ER and PR. Osteoid production was only identified in the recurrent tumor and was significant in extent therein. This case highlights the immunophenotypic changes that may occur in dedifferentiated leiomyosarcomas, and this possibility should be a consideration when an apparently undifferentiated sarcoma is identified in a patient with a history of uterine leiomyosarcoma. In our case, the expression of ER and PR provided significant supportive evidence of the uterine origin of the recurrent tumor.

Differential expression of myogenic regulatory genes and Msx-1 during dedifferentiation and redifferentiation of regenerating amphibian limbs.

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Simon, H G; Nelson, C; Goff, D; Laufer, E; Morgan, B A; Tabin, C

1995-01-01

An amputated limb of an adult urodele amphibian is capable of undergoing regeneration. The new structures form from an undifferentiated mass of cells called the regenerative blastema. The cells of the blastema are believed to derive from differentiated tissues of the adult limb. However, the exact source of these cells and the process by which they undergo dedifferentiation are poorly understood. In order to elucidate the molecular and cellular basis for dedifferentiation we isolated a number of genes which are potential regulators of the process. These include Msx-1, which is believed to support the undifferentiated and proliferative state of cells in the embryonic limb bud; and two members of the myogenic regulatory gene family, MRF-4 and Myf-5, which are expressed in differentiated muscle and regulate muscle-specific gene activity. As anticipated, we find that Msx-1 is strongly up-regulated during the initiation of regeneration. It remains expressed throughout regeneration but is not found in the fully regenerated limb. The myogenic gene MRF-4 has the reverse expression pattern. It is expressed in adult limb muscle, is rapidly shut off in early regenerative blastemas, and is only reexpressed at the completion of regeneration. These kinetics are paralleled by those of a muscle-specific Myosin gene. In contrast Myf-5, a second member of the myogenic gene family, continues to be expressed throughout the regenerative process. Thus, MRF-4 and Myf-5 are likely to play distinct roles during regeneration. MRF-4 may directly regulate muscle phenotype and as such its repression may be a key event in dedifferentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

Dedifferentiated chondrosarcoma

International Nuclear Information System (INIS)

Mercuri, M.; Picci, P.; Campanacci, L.; Rulli, E.

1995-01-01

We reviewed 74 cases of dedifferentiated central and peripheral chondrosarcoma. The diagnosis is often suspected on the basis of the clinical course and careful evaluation of the radiographic characteristics. Central dedifferentiated chondrosarcoma can be classified radiographically into three types. In type 1 (36 cases in our review) the radiographic features are the same as those of a central chondrosarcoma, with the addition of a region with very aggressive radiographic features. Type 2 lesions (20 cases) resemble the underlying benign enchondroma but also have destructive changes and/or a large soft tissue mass. Type 3 lesions (8 cases) are not distinctive radiographically and present as a very high grade destructive lesion of bone. These cases are diagnosed following biopsy or tumour resection. The prognosis of these tumours is extremely poor, with 13% overall 5-year survival in this series. Improved survival was found in those cases where diagnosis was prompt and surgical treatment with a wide or radical margin was attained. No benefit was found from the use of adjuvant chemotherapy or radiotherapy. Thus, early recognition of the characteristic radiographic features, adequate histological sampling, and wide or radical surgical margins are necessary for satisfactory management of this highly malignant variant of chondrosarcoma. (orig.)

Statins as a new therapeutic approach in dedifferentiated thyroid cancer?

International Nuclear Information System (INIS)

Hofmann, A.; John, P.; Sinzinger, H.; Staudenherz, A.; Schaffarich, M.P.

2006-01-01

Generally, primary differentiated tumours are removed surgically followed by adjuvant radioiodine treatment. The effect and outcome of radioiodine ablation depends on the uptake in the thyroid carcinoma cells. But, about one third of patients with local recurrent thyroid carcinomas or distant metastases do not respond to iodine treatment due to loss of differentiation. Prognosis was impaired if tumour cells are losing the capability for radioiodine uptake due to dedifferentiation. However, several trials have been attempted to induce re-differentiation of tumour cells in order to regain their potential for radioiodine uptake. (orig.)

The Wound Microenvironment Reprograms Schwann Cells to Invasive Mesenchymal-like Cells to Drive Peripheral Nerve Regeneration.

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Clements, Melanie P; Byrne, Elizabeth; Camarillo Guerrero, Luis F; Cattin, Anne-Laure; Zakka, Leila; Ashraf, Azhaar; Burden, Jemima J; Khadayate, Sanjay; Lloyd, Alison C; Marguerat, Samuel; Parrinello, Simona

2017-09-27

Schwann cell dedifferentiation from a myelinating to a progenitor-like cell underlies the remarkable ability of peripheral nerves to regenerate following injury. However, the molecular identity of the differentiated and dedifferentiated states in vivo has been elusive. Here, we profiled Schwann cells acutely purified from intact nerves and from the wound and distal regions of severed nerves. Our analysis reveals novel facets of the dedifferentiation response, including acquisition of mesenchymal traits and a Myc module. Furthermore, wound and distal dedifferentiated Schwann cells constitute different populations, with wound cells displaying increased mesenchymal character induced by localized TGFβ signaling. TGFβ promotes invasion and crosstalks with Eph signaling via N-cadherin to drive collective migration of the Schwann cells across the wound. Consistently, Tgfbr2 deletion in Schwann cells resulted in misdirected and delayed reinnervation. Thus, the wound microenvironment is a key determinant of Schwann cell identity, and it promotes nerve repair through integration of multiple concerted signals. VIDEO ABSTRACT. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Use of rat mature adipocyte-derived dedifferentiated fat cells as a cell source for periodontal tissue regeneration

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Daisuke eAkita

2016-02-01

Full Text Available Lipid-free fibroblast-like cells, known as dedifferentiated fat (DFAT cells, can be generated from mature adipocytes with a large single lipid droplet. DFAT cells can re-establish their active proliferation ability and can transdifferentiate into various cell types under appropriate culture conditions. The first objective of this study was to compare the multilineage differentiation potential of DFAT cells with that of adipose-derived stem cells (ASCs on mesenchymal stem cellsWe obtained DFAT cells and ASCs from inbred rats and found that rat DFAT cells possess higher osteogenic differentiation potential than rat ASCs. On the other hand, DFAT cells show similar adipogenic differentiation, and chondrogenic differentiation potential in comparison with ASCs. The second objective of this study was to assess the regenerative potential of DFAT cells combined with novel solid scaffolds composed of PLGA (Poly d, l-lactic-co-glycolic acid on periodontal tissue, and to compare this with the regenerative potential of ASCs combined with PLGA scaffolds. Cultured DFAT cells and ASCs were seeded onto PLGA scaffolds (DFAT/PLGA and ASCs/PLGA and transplanted into periodontal fenestration defects in rat mandible. Micro computed tomography analysis revealed a significantly higher amount of bone regeneration in the DFAT/PLGA group compared with that of ASCs/PLGA and PLGA-alone groups at 2, 3 and 5 weeks after transplantation. Similarly, histomorphometric analysis showed that DFAT/PLGA groups had significantly greater width of cementum, periodontal ligament and alveolar bone than ASCs/PLGA and PLGA-alone groups. In addition, transplanted fluorescent-labeled DFAT cells were observed in the periodontal ligament beside the newly formed bone and cementum. These findings suggest that DFAT cells have a greater potential for enhancing periodontal tissue regeneration than ASCs. Therefore, DFAT cells are a promising cell source for periodontium regeneration.

TCF-1 participates in the occurrence of dedifferentiated chondrosarcoma.

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Xu, Xiaolong; Tang, Xiaodong; Guo, Wei; Yang, Kang; Ren, Tingting

2016-10-01

The present study demonstrated that T cell factor 1 (TCF-1) protein, a component of the canonical Wnt/β-catenin signaling pathway, can regulate the expression of runt-related transcription factor 2 (runx2) gene and Sry-related HMG box 9 (sox9) gene, which may participate in the differentiation of chondrosarcoma. Dedifferentiated chondrosarcoma (DDCS) is a special variant of conventional chondrosarcoma (CCS), associated with poor survival and high metastasis rate. However, little is known about the mechanism of its occurrence; thus, no effective treatment is available except surgery. Earlier, high expression of runx2 and low expression of sox9 were found in DDCS compared with CCS. Using Western blot to detect clinical tissue samples (including 8 CCS samples and 8 DDCS samples) and immunohistochemistry to detect 85 different-grade chondrosarcoma specimens, a high expression of TCF-1 in DDCS tissues was found compared with CCS tissues. This difference in expression was related to patients' prognosis. Results of luciferase, chromatin immunoprecipitation, and gel electrophoresis mobility shift assays demonstrated that TCF-1 protein could bind to the promoter of runx2 gene directly and sox9 gene indirectly. Hence, it could regulate expression of runx2 gene positively and sox9 gene negatively. Furthermore, in vitro and in vivo experiments showed that TCF-1 protein was closely related to the phenotype and aggressiveness of chondrosarcoma. In conclusion, this study proved that TCF-1 participates in the dedifferentiation of DDCS, which may be mediated by runx2 gene and sox9 gene. Also, TCF-1 can be of important prognostic value and a promising therapeutic target for DDCS patients.

Nicotine promotes initiation and progression of KRAS-induced pancreatic cancer via Gata6-dependent dedifferentiation of acinar cells in mice.

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Hermann, Patrick C; Sancho, Patricia; Cañamero, Marta; Martinelli, Paola; Madriles, Francesc; Michl, Patrick; Gress, Thomas; de Pascual, Ricardo; Gandia, Luis; Guerra, Carmen; Barbacid, Mariano; Wagner, Martin; Vieira, Catarina R; Aicher, Alexandra; Real, Francisco X; Sainz, Bruno; Heeschen, Christopher

2014-11-01

Although smoking is a leading risk factor for pancreatic ductal adenocarcinoma (PDAC), little is known about the mechanisms by which smoking promotes initiation or progression of PDAC. We studied the effects of nicotine administration on pancreatic cancer development in Kras(+/LSLG12Vgeo);Elas-tTA/tetO-Cre (Ela-KRAS) mice, Kras(+/LSLG12D);Trp53+/LSLR172H;Pdx-1-Cre (KPC) mice (which express constitutively active forms of KRAS), and C57/B6 mice. Mice were given nicotine for up to 86 weeks to produce blood levels comparable with those of intermediate smokers. Pancreatic tissues were collected and analyzed by immunohistochemistry and reverse transcriptase polymerase chain reaction; cells were isolated and assayed for colony and sphere formation and gene expression. The effects of nicotine were also evaluated in primary pancreatic acinar cells isolated from wild-type, nAChR7a(-/-), Trp53(-/-), and Gata6(-/-);Trp53(-/-) mice. We also analyzed primary PDAC cells that overexpressed GATA6 from lentiviral expression vectors. Administration of nicotine accelerated transformation of pancreatic cells and tumor formation in Ela-KRAS and KPC mice. Nicotine induced dedifferentiation of acinar cells by activating AKT-ERK-MYC signaling; this led to inhibition of Gata6 promoter activity, loss of GATA6 protein, and subsequent loss of acinar differentiation and hyperactivation of oncogenic KRAS. Nicotine also promoted aggressiveness of established tumors as well as the epithelial-mesenchymal transition, increasing numbers of circulating cancer cells and their dissemination to the liver, compared with mice not exposed to nicotine. Nicotine induced pancreatic cells to acquire gene expression patterns and functional characteristics of cancer stem cells. These effects were markedly attenuated in K-Ras(+/LSL-G12D);Trp53(+/LSLR172H);Pdx-1-Cre mice given metformin. Metformin prevented nicotine-induced pancreatic carcinogenesis and tumor growth by up-regulating GATA6 and promoting

MicroRNA-99a inhibits insulin-induced proliferation, migration, dedifferentiation, and rapamycin resistance of vascular smooth muscle cells by inhibiting insulin-like growth factor-1 receptor and mammalian target of rapamycin

International Nuclear Information System (INIS)

Zhang, Zi-wei; Guo, Rui-wei; Lv, Jin-lin; Wang, Xian-mei; Ye, Jin-shan; Lu, Ni-hong; Liang, Xing; Yang, Li-xia

2017-01-01

Patients with type 2 diabetes mellitus (T2DM) are characterized by insulin resistance and are subsequently at high risk for atherosclerosis. Hyperinsulinemia has been associated with proliferation, migration, and dedifferentiation of vascular smooth muscle cells (VSMCs) during the pathogenesis of atherosclerosis. Moreover, insulin-like growth factor-1 receptor (IGF-1R) and mammalian target of rapamycin (mTOR) have been demonstrated to be the underlying signaling pathways. Recently, microRNA-99a (miR-99a) has been suggested to regulate the phenotypic changes of VSMCs in cancer cells. However, whether it is involved in insulin-induced changes of VSCMs has not been determined. In this study, we found that insulin induced proliferation, migration, and dedifferentiation of mouse VSMCs in a dose-dependent manner. Furthermore, the stimulating effects of high-dose insulin on proliferation, migration, and dedifferentiation of mouse VSMCs were found to be associated with the attenuation of the inhibitory effects of miR-99a on IGF-1R and mTOR signaling activities. Finally, we found that the inducing effect of high-dose insulin on proliferation, migration, and dedifferentiation of VSMCs was partially inhibited by an active mimic of miR-99a. Taken together, these results suggest that miR-99a plays a key regulatory role in the pathogenesis of insulin-induced proliferation, migration, and phenotype conversion of VSMCs at least partly via inhibition of IGF-1R and mTOR signaling. Our results provide evidence that miR-99a may be a novel target for the treatment of hyperinsulinemia-induced atherosclerosis. - Highlights: • Suggesting a new mechanism of insulin-triggered VSMC functions. • Providing a new therapeutic strategies that target atherosclerosis in T2DM patients. • Providing a new strategies that target in-stent restenosis in T2DM patients.

The ageing phenome: caloric restriction and hormones promote neural cell survival, growth, and de-differentiation.

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Timiras, Paola S; Yaghmaie, Farzin; Saeed, Omar; Thung, Elaine; Chinn, Garrett

2005-01-01

The phenome represents the observable properties of an organism that have developed under the continued influences of both genome and environmental factors. Phenotypic properties are expressed through the functions of cells, organs and body systems that operate optimally, close to equilibrium. In complex organisms, maintenance of the equilibrium is achieved by the interplay of several regulatory mechanisms. In the elderly, dynamic instability may lead to progressive loss of normal function, failure of adaptation and increased pathology. Extensive research (reported elsewhere in this journal) has demonstrated that genetic manipulations of endocrine signaling in flies, worms and mice increase longevity. Another effective strategy for prolonging the lifespan is caloric restriction: in data presented here, the persistence of estrogen-sensitive cells in the hypothalamus of caloric restricted 22-month-old female mice, may explain the persistence of reproductive function at an age, when reproductive function has long ceased in ad libitum fed controls. Still another strategy utilizes the effects of epidermal growth factor (EGF) to promote in vitro proliferation of neuroglia, astrocytes and oligodendrocytes. Their subsequent de-differentiation generates immature precursor cells potentially capable of differentiating into neuroblasts and neurons. These and other examples suggest that, in terms of functional outcomes, "the genome proposes but the phenome disposes".

Case report 347: Dedifferentiated chondrosarcoma: Grade 4 fibrosarcoma arising in grade 1 chandrosarcoma (femur)

International Nuclear Information System (INIS)

Frassica, F.J.; Unni, K.K.; Sim, F.H.

1986-01-01

In summary, a 74-year-old woman presented with a 2-week history of pain in the left thigh. Dedifferentiated lesions have a very poor prognosis - less than 10% 5-year survivals. This figure contrasts with the 5-year survival rate of 59% for individuals with conventional chondrosarcoma. Fibrosarcoma is less common than osteosarcoma as the highly malignant, anaplastic portion of a dedifferentiated chondrosarcoma. In an unpublished series of 79 cases of dedifferentiated chondrosarcoma from the Mayo Clinic 43 showed osteosarcoma and 33 fibrosarcoma (Table 3). (orig.)

Epithelial-to-mesenchymal transition and estrogen receptor α mediated epithelial dedifferentiation mark the development of benign prostatic hyperplasia.

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Shao, Rui; Shi, Jiandang; Liu, Haitao; Shi, Xiaoyu; Du, Xiaoling; Klocker, Helmut; Lee, Chung; Zhu, Yan; Zhang, Ju

2014-06-01

Epithelial-to-mesenchymal transition (EMT) has been reported involved in the pathogenesis of fibrotic disorders and associated with stemness characteristics. Recent studies demonstrated that human benign prostatic hyperplasia (BPH) development involves accumulation of mesenchymal-like cells derived from the prostatic epithelium. However, the inductive factors of EMT in the adult prostate and the cause-and-effect relationship between EMT and stemness characteristics are not yet resolved. EMT expression patterns were immunohistochemically identified in the human epithelia of normal/BPH prostate tissue and in a rat BPH model induced by estrogen/androgen (E2/T, ratio 1:100) alone or in the presence of the ER antagonist raloxifene. Gene expression profiles were analyzed in micro-dissected prostatic epithelia of rat stimulated by E2/T for 3 days. Two main morphological features both accompanied with EMT were observed in the epithelia of human BPH. Luminal cells undergoing EMT dedifferentiated from a cytokeratin (CK) CK18(+) /CK8(+) /CK19(+) to a CK18(-) /CK8(+) /CK19(-) phenotype and CK14 expression increased in basal epithelial cells. ERα expression was closely related to these dedifferentiated cells and the expression of EMT markers. A similar pattern of EMT events was observed in the E2/T induced rat model of BPH in comparison to the prostates of untreated rats, which could be prevented by raloxifene. Epithelial and mesenchymal phenotype switching is an important mechanism in the etiology of BPH. ERα mediated enhanced estrogenic effect is a crucial inductive factor of epithelial dedifferentiation giving rise to activation of an EMT program in prostate epithelium. © 2014 Wiley Periodicals, Inc.

Dedifferentiated chondrosarcoma: Radiological features, prognostic factors and survival statistics in 23 patients

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Liu, Chenglei; Xi, Yan; Li, Mei; Jiao, Qiong; Zhang, Huizhen; Yang, Qingcheng; Yao, Weiwu

2017-01-01

Background Dedifferentiated chondrosarcoma is a rare, highly malignant tumor with a poor survival. There are many confusing issues concerning the imaging feature that can facilitate early diagnosis and the factors that might be related to outcomes. Methods Twenty-three patients with dedifferentiated chondrosarcoma confirmed by pathology were retrospectively reviewed from 2008 to 2015. The patients’ clinical information, images from radiographs (n = 17), CT (n = 19), and MRI (n = 17), histological features, treatment and prognosis were analyzed. Results There were 12 males and 11 females, and the mean age was 50.39 years old. Fourteen cases affected the axial bone (pelvis, spine), and 9 cases involved the appendicular bone. Seven (41.17%), 9 (47.36), and 12 (66.66%) lesions showed a biphasic nature on radiograph, CT and MRI, respectively. Of the lesions, 17.39% (4/23) were accompanied by pathological fractures. Histologically, the cartilage component was considered histological Grade1 in 12 patients and Grade 2 in 11 patients. The dedifferentiated component showed features of osteosarcoma in 8 cases, malignant fibrous histiocytoma in3 cases, myofibroblastic sarcoma in 1 case and spindle cell sarcoma in 11cases. Twenty-two cases were treated with surgical resection, and 17 cases achieved adequate (wide or radical) surgical margin. In 8 cases, surgery was combined with adjuvant chemotherapy. The overall median survival time was nine months; 17.4% of patients survived to five years. Conclusion Axial bone location, lung metastasis at diagnosis, inadequate surgical margin, incorrect diagnosis before surgery and pathological fractures was related to poorer outcome. Pre- or postoperative chemotherapy had no definitively effect on improved survival. PMID:28301537

Effects of combination therapy using basic fibroblast growth factor and mature adipocyte-derived dedifferentiated fat (DFAT) cells on skin graft revascularisation.

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Asami, Takashi; Soejima, Kazutaka; Kashimura, Tsutomu; Kazama, Tomohiko; Matsumoto, Taro; Morioka, Kosuke; Nakazawa, Hiroaki

2015-01-01

Although the benefits of basic fibroblast growth factor (bFGF) for wound healing and angiogenesis are well known, its effects on the process of skin graft revascularisation have not been clarified. It was hypothesised that bFGF would be beneficial to promote taking of skin grafts, but that the effect might be limited in the case of bFGF monotherapy. Therefore, this study investigated the efficacy of combination therapy using bFGF and dedifferentiated fat (DFAT) cells. DFAT cells have multilineage differentiation potential, including into endothelial cells, similar to the case of mesenchymal stem cells (MSC). Commercially available human recombinant bFGF was used. DFAT cells were prepared from SD strain rats as an adipocyte progenitor cell line from mature adipocytes. Full-thickness skin was lifted from the back of SD strain rats and then grafted back to the original wound site. Four groups were established prior to skin grafting: control group (skin graft alone), bFGF group (treated with bFGF), DFAT group (treated with DFAT cells), and combination group (treated with both bFGF and DFAT cells). Tissue specimens for histological examination were harvested 48 hours after grafting. The histological findings for the bFGF group showed vascular augmentation in the grafted dermis compared with the control group. However, the difference in the number of revascularised vessels per unit area did not reach statistical significance against the control group. In contrast, in the combination group, skin graft revascularisation was significantly promoted, especially in the upper dermis. The results suggest that replacement of the existing graft vessels was markedly promoted by the combination therapy using bFGF and DFAT cells, which may facilitate skin graft taking.

Crossing the invisible line: De-differentiation of wake, sleep and dreaming may engender both creative insight and psychopathology.

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Llewellyn, Sue

2016-11-01

Writing about dreaming, the poet Raymond Carver said "I feel as if I've crossed some kind of invisible line". In creative people, the "line" between wake, dreaming and psychopathology may be porous, engendering a de-differentiated, super-critical, hybrid state. Evidence exists for a relationship between creativity and psychopathology but its nature has been elusive. De-differentiation between wake, sleep and dreaming may be the common substrate, as dream-like cognition pervades wake and wake-like neurophysiology suffuses sleep. Chaos theory posits brain states as inherently labile, transient and dynamically unstable. Over and above transient dissociations, an enduring and, sometimes, progressive, de-differentiation may be possible. Evidence indicates that sleep and dreaming facilitate creative insight. In consequence, a mild to moderate form of de-differentiation may enhance creativity but if wake-like neurobiology permeates sleep this may disrupt sleep-dependent memory processing and emotional regulation. If de-differentiation is progressive and enduring, various forms of psychopathology may result. Copyright © 2016 Elsevier Inc. All rights reserved.

Immunophenotypic features of dedifferentiated skull base chordoma: An insight into the intratumoural heterogeneity

Directory of Open Access Journals (Sweden)

Kelvin Manuel Pińa Batista

2017-12-01

Full Text Available Chordomas are rare and low-grade malignant solid tumours, despite their histologically benign appearance, that arise in the bone from embryonic notochordal vestiges of the axial skeleton, a mesoderm-derived structure that is involved in the process of neurulation and embryonic development. Chordomas occurring in the skull base tend to arise in the basiocciput along the clivus. Three major morphological variants have been described (classical, chondroid, and atypical/dedifferentiated. The pathogenesis and molecular mechanisms involved in chordoma development remain uncertain. From a pathological standpoint, the microenvironment of a chordoma is heterogeneous, showing a dual epithelial-mesenchymal differentiation. These tumours are characterised by slow modality of biologic growth, local recurrence, low incidence of metastasis rates, and cancer stem cell (CSC phenotype. The main molecular findings are connected with brachyury immunoexpression and activation of the downstream Akt and mTOR signalling pathways. The differentiation between typical and atypical chordomas is relevant because the tumoural microenvironment and prognosis are partially different. This review provides an insight into the recent and relevant concepts and histochemical markers expressed in chordomas, with special emphasis on dedifferentiated chordomas and their prognostic implications.

Dedifferentiation, Proliferation, and Redifferentiation of Adult Mammalian Cardiomyocytes After Ischemic Injury.

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Wang, Wei Eric; Li, Liangpeng; Xia, Xuewei; Fu, Wenbin; Liao, Qiao; Lan, Cong; Yang, Dezhong; Chen, Hongmei; Yue, Rongchuan; Zeng, Cindy; Zhou, Lin; Zhou, Bin; Duan, Dayue Darrel; Chen, Xiongwen; Houser, Steven R; Zeng, Chunyu

2017-08-29

Adult mammalian hearts have a limited ability to generate new cardiomyocytes. Proliferation of existing adult cardiomyocytes (ACMs) is a potential source of new cardiomyocytes. Understanding the fundamental biology of ACM proliferation could be of great clinical significance for treating myocardial infarction (MI). We aim to understand the process and regulation of ACM proliferation and its role in new cardiomyocyte formation of post-MI mouse hearts. β-Actin-green fluorescent protein transgenic mice and fate-mapping Myh6-MerCreMer-tdTomato/lacZ mice were used to trace the fate of ACMs. In a coculture system with neonatal rat ventricular myocytes, ACM proliferation was documented with clear evidence of cytokinesis observed with time-lapse imaging. Cardiomyocyte proliferation in the adult mouse post-MI heart was detected by cell cycle markers and 5-ethynyl-2-deoxyuridine incorporation analysis. Echocardiography was used to measure cardiac function, and histology was performed to determine infarction size. In vitro, mononucleated and bi/multinucleated ACMs were able to proliferate at a similar rate (7.0%) in the coculture. Dedifferentiation proceeded ACM proliferation, which was followed by redifferentiation. Redifferentiation was essential to endow the daughter cells with cardiomyocyte contractile function. Intercellular propagation of Ca 2+ from contracting neonatal rat ventricular myocytes into ACM daughter cells was required to activate the Ca 2+ -dependent calcineurin-nuclear factor of activated T-cell signaling pathway to induce ACM redifferentiation. The properties of neonatal rat ventricular myocyte Ca 2+ transients influenced the rate of ACM redifferentiation. Hypoxia impaired the function of gap junctions by dephosphorylating its component protein connexin 43, the major mediator of intercellular Ca 2+ propagation between cardiomyocytes, thereby impairing ACM redifferentiation. In vivo, ACM proliferation was found primarily in the MI border zone. An ischemia

Transplantation of dedifferentiated fat cell-derived micromass pellets contributed to cartilage repair in the rat osteochondral defect model.

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Shimizu, Manabu; Matsumoto, Taro; Kikuta, Shinsuke; Ohtaki, Munenori; Kano, Koichiro; Taniguchi, Hiroaki; Saito, Shu; Nagaoka, Masahiro; Tokuhashi, Yasuaki

2018-03-20

Mature adipocyte-derived dedifferentiated fat (DFAT) cells possesses the ability to proliferate effectively and the potential to differentiate into multiple linages of mesenchymal tissue; similar to adipose-derived stem cells (ASCs). The purpose of this study is to examine the effects of DFAT cell transplantation on cartilage repair in a rat model of osteochondral defects. Full-thickness osteochondral defects were created in the knees of Sprague-Dawley rats bilaterally. Cartilage-like micromass pellets were prepared from green fluorescent protein (GFP)-labeled rat DFAT cells and subsequently transplanted into the affected right knee of these rats. Defects in the left knee were used as a control. Macroscopic and microscopic changes of treated and control defects were evaluated up to 12 weeks post-treatment with DFAT cells. To observe the transplanted cells, sectioned femurs were immunostained for GFP and type II collagen. DFAT cells formed micromass pellets expressing characteristics of immature cartilage in vitro. In the DFAT cell-transplanted limbs, the defects were completely filled with white micromass pellets as early as 2 weeks post-treatment. These limbs became smooth at 4 weeks. Conversely, the defects in the control limbs were still not repaired by 4 weeks. Macroscopic ICRS scores at 2 and 4 weeks were significantly higher in the DFAT cells-transplanted limbs compared to those of the control limbs. The modified O'Driscol histological scores for the DFAT cell-transplanted limbs were significantly higher than those of the control limbs at corresponding time points. GFP-positive DAFT cells were detected in the transplanted area at 2 weeks but hardly visible at 12 weeks post-operation. Transplantation of DFAT cell-derived micromass pellets contribute to cartilage repair in a rat osteochondral defect model. DFAT cell transplantation may be a viable therapeutic strategy for the repair of osteochondral injuries. Copyright © 2018 The Authors. Published by

Adipogenic placenta-derived mesenchymal stem cells are not lineage restricted by withdrawing extrinsic factors: developing a novel visual angle in stem cell biology.

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Hu, C; Cao, H; Pan, X; Li, J; He, J; Pan, Q; Xin, J; Yu, X; Li, J; Wang, Y; Zhu, D; Li, L

2016-03-17

Current evidence implies that differentiated bone marrow mesenchymal stem cells (BMMSCs) can act as progenitor cells and transdifferentiate across lineage boundaries. However, whether this unrestricted lineage has specificities depending on the stem cell type is unknown. Placental-derived mesenchymal stem cells (PDMSCs), an easily accessible and less invasive source, are extremely useful materials in current stem cell therapies. No studies have comprehensively analyzed the transition in morphology, surface antigens, metabolism and multilineage potency of differentiated PDMSCs after their dedifferentiation. In this study, we showed that after withdrawing extrinsic factors, adipogenic PDMSCs reverted to a primitive cell population and retained stem cell characteristics. The mitochondrial network during differentiation and dedifferentiation may serve as a marker of absent or acquired pluripotency in various stem cell models. The new population proliferated faster than unmanipulated PDMSCs and could be differentiated into adipocytes, osteocytes and hepatocytes. The cell adhesion molecules (CAMs) signaling pathway and extracellular matrix (ECM) components modulate cell behavior and enable the cells to proliferate or differentiate during the differentiation, dedifferentiation and redifferentiation processes in our study. These observations indicate that the dedifferentiated PDMSCs are distinguishable from the original PDMSCs and may serve as a novel source in stem cell biology and cell-based therapeutic strategies. Furthermore, whether PDMSCs differentiated into other lineages can be dedifferentiated to a primitive cell population needs to be investigated.

Dedifferentiated chondrosarcoma with "adamantinoma-like" features: A case report and review of literature.

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Gambarotti, M; Righi, A; Frisoni, T; Donati, D; Vanel, D; Sbaraglia, M; Dei Tos, A P

2017-06-01

Dedifferentiated chondrosarcoma is defined by the presence of a low grade malignant cartilaginous component juxtaposed to a high grade malignant non-cartilaginous sarcomatous components. Only 4 cases in which the high grade component showed epithelial differentiation have been reported in the literature; three featured a squamous and the one a glandular epithelial component. Here we describe a case of dedifferentiated chondrosarcoma exhibiting epithelial "adamantinoma-like" basaloid features. The patient underwent wide resection of the proximal tibia and post-operative chemotherapy and died 8 months after the diagnosis due to lung and bone metastases. Copyright © 2017 Elsevier GmbH. All rights reserved.

Regulation of nonmuscle myosin II during 3-methylcholanthrene induced dedifferentiation of C2C12 myotubes

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Dey, Sumit K.; Saha, Shekhar; Das, Provas; Das, Mahua R.; Jana, Siddhartha S., E-mail: bcssj@iacs.res.in

2014-08-01

3-Methylcholanthrene (3MC) induces tumor formation at the site of injection in the hind leg of mice within 110 days. Recent reports reveal that the transformation of normal muscle cells to atypical cells is one of the causes for tumor formation, however the molecular mechanism behind this process is not well understood. Here, we show in an in vitro study that 3MC induces fragmentation of multinucleate myotubes into viable mononucleates. These mononucleates form colonies when they are seeded into soft agar, indicative of cellular transformation. Immunoblot analysis reveals that phosphorylation of myosin regulatory light chain (RLC{sub 20}) is 5.6±0.5 fold reduced in 3MC treated myotubes in comparison to vehicle treated myotubes during the fragmentation of myotubes. In contrast, levels of myogenic factors such as MyoD, Myogenin and cell cycle regulators such as Cyclin D, Cyclin E1 remain unchanged as assessed by real-time PCR array and reverse transcriptase PCR analysis, respectively. Interestingly, addition of the myosin light chain kinase inhibitor, ML-7, enhances the fragmentation, whereas phosphatase inhibitor perturbs the 3MC induced fragmentation of myotubes. These results suggest that decrease in RLC{sub 20} phosphorylation may be associated with the fragmentation step of dedifferentiation. - Highlights: • 3-Methylcholanthrene induces fragmentation of C2C12-myotubes. • Dedifferentiation can be divided into two steps – fragmentation and proliferation. • Fragmentation is associated with rearrangement of nonmuscle myosin II. • Genes associated with differentiation and proliferation are not altered during fragmentation. • Phosphorylation of myosin regulatory light chain is reduced during fragmentation.

Oct4 Methylation-Mediated Silencing As an Epigenetic Barrier Preventing Müller Glia Dedifferentiation in a Murine Model of Retinal Injury.

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Reyes-Aguirre, Luis I; Lamas, Monica

2016-01-01

Müller glia (MG) is the most abundant glial type in the vertebrate retina. Among its many functions, it is capable of responding to injury by dedifferentiating, proliferating, and differentiating into every cell types lost to damage. This regenerative ability is notoriously absent in mammals. We have previously reported that cultured mammalian MG undergoes a partial dedifferentiation, but fails to fully acquire a progenitor phenotype and differentiate into neurons. This might be explained by a mnemonic mechanism comprised by epigenetic traits, such as DNA methylation. To achieve a better understanding of this epigenetic memory, we studied the expression of pluripotency-associated genes, such as Oct4, Nanog , and Lin28 , which have been reported as necessary for regeneration in fish, at early times after NMDA-induced retinal injury in a mouse experimental model. We found that although Oct4 is expressed rapidly after damage (4 hpi), it is silenced at 24 hpi. This correlates with a significant decrease in the DNA methyltransferase Dnmt3b expression, which returns to basal levels at 24 hpi. By MS-PCR, we observed a decrease in Oct4 methylation levels at 4 and 12 hpi, before returning to a fully methylated state at 24 hpi. To demonstrate that these changes are restricted to MG, we separated these cells using a GLAST antibody coupled with magnetic beads. Finally, intravitreous administration of the DNA-methyltransferase inhibitor SGI-1027 induced Oct4 expression at 24 hpi in MG. Our results suggest that mammalian MG injury-induced dedifferentiation could be restricted by DNA methylation, which rapidly silences Oct4 expression, preventing multipotency acquisition.

The Urodele Limb Regeneration Blastema: The Cell Potential

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Kenyon S. Tweedell

2010-01-01

Full Text Available The developmental potential of the limb regeneration blastema, a mass of mesenchymal cells of mixed origins, was once considered as being pluripotent, capable of forming all cell types. Now evidence asserts that the blastema is a heterogeneous mixture of progenitor cells derived from tissues of the amputation site, with limited developmental potential, plus various stem cells with multipotent abilities. Many specialized cells, bone, cartilage, muscle, and Schwann cells, at the injury site undergo dedifferentiation to a progenitor state and maintain their cell lineage as they redifferentiate in the regenerate. Muscle satellite reserve stem cells that are active in repair of injured muscle may also dedifferentiate and contribute new muscle cells to the limb blastema. Other cells from the dermis act as multipotent stem cells that replenish dermal fibroblasts and differentiate into cartilage. The blastema primordium is a self-organized, equipotential system, but at the cellular level can compensate for specific cell loss. It is able to induce dedifferentiation of introduced exogenous cells and such cells may be transformed into new cell types. Indigenous cells of the blastema associated with amputated tissues may also transform or possibly transdifferentiate into new cell types. The blastema is a microenvironment that enables dedifferentiation, redifferentiation, transdifferentiation, and stem cell activation, leading to progenitor cells of the limb regenerate.

Regulation of a TGF-β1-CD147 self-sustaining network in the differentiation plasticity of hepatocellular carcinoma cells.

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Wu, J; Lu, M; Li, Y; Shang, Y-K; Wang, S-J; Meng, Y; Wang, Z; Li, Z-S; Chen, H; Chen, Z-N; Bian, H

2016-10-20

Cellular plasticity has an important role in the progression of hepatocellular carcinoma (HCC). In this study, the involvement of a TGF-β1-CD147 self-sustaining network in the regulation of the dedifferentiation progress was fully explored in HCC cell lines, hepatocyte-specific basigin/CD147-knockout mice and human HCC tissues. We demonstrated that TGF-β1 stimulation upregulated CD147 expression and mediated the dedifferentiation of HCC cells, whereas all-trans-retinoic acid induced the downregulation of CD147 and promoted differentiation in HCC cells. Overexpression of CD147 induced the dedifferentiation and enhanced the malignancy of HCC cells, and increased the transcriptional expression of TGF-β1 by activating β-catenin. CD147-induced matrix metalloproteinase (MMP) production activated pro-TGF-β1. The activated TGF-β1 signaling subsequently repressed the HNF4α expression via Smad-Snail1 signaling and enhanced the dedifferentiation progress. Hepatocyte-specific basigin/CD147-knockout mice decreased the susceptibility to N-nitrosodiethylamine-induced tumorigenesis by suppressing TGF-β1-CD147 signaling and inhibiting dedifferentiation in hepatocytes during tumor progression. CD147 was positively correlated with TGF-β1 and negatively correlated with HNF4α in human HCC tissues. Positive CD147 staining and lower HNF4α levels in tumor tissues were significantly associated with poor survival of patients with HCC. The overexpression of HNF4α and Smad7 and the deletion of CD147 by lentiviral vectors jointly reprogrammed the expression profile of hepatocyte markers and attenuated malignant properties including proliferation, cell survival and tumor growth of HCC cells. Our results highlight the important role of the TGF-β1-CD147 self-sustaining network in driving HCC development by regulating differentiation plasticity, which provides a strong basis for further investigations of the differentiation therapy of HCC targeting TGF-β1 and CD147.

Reversibility of β-Cell-Specific Transcript Factors Expression by Long-Term Caloric Restriction in db/db Mouse

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Chunjun Sheng

2016-01-01

Full Text Available Type 2 diabetes (T2D is characterized by β-cell dedifferentiation, but underlying mechanisms remain unclear. The purpose of the current study was to explore the mechanisms of β-cell dedifferentiation with and without long-term control of calorie intake. We used a diabetes mouse model (db/db to analyze the changes in the expression levels of β-cell-specific transcription factors (TFs and functional factors with long-term caloric restriction (CR. Our results showed that chronic euglycemia was maintained in the db/db mice with long-term CR intervention, and β-cell dedifferentiation was significantly reduced. The expression of Glut2, Pdx1, and Nkx6.1 was reversed, while MafA expression was significantly increased with long-term CR. GLP-1 pathway was reactivated with long-term CR. Our work showed that the course of β-cell dedifferentiation can intervene by long-term control of calorie intake. Key β-cell-specific TFs and functional factors play important roles in maintaining β-cell differentiation. Targeting these factors could optimize T2D therapies.

Dedifferentiated chondrosarcoma in patients with multiple osteochondromatosis: report of a case and review of the literature

International Nuclear Information System (INIS)

Kilpatrick, S.E.; Pike, E.J.; Ward, W.G.; Pope, T.L.

1997-01-01

Multiple osteochondromatosis (MOS) is a familial disorder of autosomal dominant transmission characterized by the development of multiple exostoses and often derangements of epiphyseal cartilage, sometimes resulting in long bone growth retardation. Patients with the disorder appear to be at increased risk for developing secondary chondrosarcomas. Rarely, dedifferentiated chondrosarcomas may also occur. We report a single case of a 27-year-old man with multiple osteochondromatosis who developed a fatal dedifferentiated chondrosarcoma. Radiographically, the neoplasm arose from the pelvis completely destroying the left pubic ramus. Subsequently, the patient underwent preoperative chemotherapy followed by a left external hemipelvectomy. On pathologic examination, the tumor was characterized by high-grade pleomorphic sarcoma sharply juxtaposed to a low-grade chondrosarcoma. The patient ultimately died of widespread metastatic sarcoma. (orig.). With 7 figs

Dedifferentiated chondrosarcoma in patients with multiple osteochondromatosis: report of a case and review of the literature

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Kilpatrick, S.E. [Department of Pathology, North Carolina Baptist Hospitals, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC (United States); Pike, E.J. [Department of Radiology, North Carolina Baptist Hospitals, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC (United States); Ward, W.G. [Department of Orthopaedics, North Carolina Baptist Hospitals, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC (United States); Pope, T.L. [Department of Radiology, North Carolina Baptist Hospitals, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, NC (United States)

1997-06-01

Multiple osteochondromatosis (MOS) is a familial disorder of autosomal dominant transmission characterized by the development of multiple exostoses and often derangements of epiphyseal cartilage, sometimes resulting in long bone growth retardation. Patients with the disorder appear to be at increased risk for developing secondary chondrosarcomas. Rarely, dedifferentiated chondrosarcomas may also occur. We report a single case of a 27-year-old man with multiple osteochondromatosis who developed a fatal dedifferentiated chondrosarcoma. Radiographically, the neoplasm arose from the pelvis completely destroying the left pubic ramus. Subsequently, the patient underwent preoperative chemotherapy followed by a left external hemipelvectomy. On pathologic examination, the tumor was characterized by high-grade pleomorphic sarcoma sharply juxtaposed to a low-grade chondrosarcoma. The patient ultimately died of widespread metastatic sarcoma. (orig.). With 7 figs.

The stem cell state in plant development and in response to stress

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Gideon eGrafi

2011-10-01

Full Text Available Stem cells are commonly defined by their developmental capabilities, namely, self-renewal and multitype differentiation, yet the biology of stem cells and their inherent features both in plants and animals are only beginning to be elucidated. In this review article we highlight the stem cell state in plants (with reference to animals and the plastic nature of plant somatic cells (often referred to as totipotency as well as the essence of cellular dedifferentiation. Based on recent published data, we illustrate the picture of stem cells with emphasis on their open chromatin conformation. We discuss the process of dedifferentiation and highlight its transient nature, its distinction from reentry into the cell cycle and its activation following exposure to stress. We also discuss the potential hazard that can be brought about by stress-induced dedifferentiation and its major impact on the genome, which can undergo stochastic, abnormal reorganization leading to genetic variation by means of DNA transposition and/or DNA recombination.

Dedifferentiated retroperitoneal liposarcoma presenting as right inguinal hernia: A case report

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Kim, Jung Myung; Lee, Su Lim; Ku, Young Mi [Dept. of Radiology, Uijeongbu St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu (Korea, Republic of); Choi, Moon Hyung [Dept. of Radiology, Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

2016-01-15

Retroperitoneal liposarcomas usually present as painless, slow-growing abdominal masses. When masses grow large enough to compress surrounding structures, symptoms may occur. Retroperitoneal liposarcoma clinically manifesting as inguinal hernia is a very rare entity; only 11 cases have been reported. Herein, we present radiographic features of a 37-year-old male with a painless palpable mass in the right groin that was identified as dedifferentiated retroperitoneal liposarcoma herniated through the right inguinal canal.

Neurotrophic regulation of fibroblast dedifferentiation during limb skeletal regeneration in the axolotl (Ambystoma mexicanum).

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Satoh, Akira; Cummings, Gillian M C; Bryant, Susan V; Gardiner, David M

2010-01-15

The ability of animals to repair tissue damage is widespread and impressive. Among tissues, the repair and remodeling of bone occurs during growth and in response to injury; however, loss of bone above a threshold amount is not regenerated, resulting in a "critical-size defect" (CSD). The development of therapies to replace or regenerate a CSD is a major focus of research in regenerative medicine and tissue engineering. Adult urodeles (salamanders) are unique in their ability to regenerate complex tissues perfectly, yet like mammals do not regenerate a CSD. We report on an experimental model for the regeneration of a CSD in the axolotl (the Excisional Regeneration Model) that allows for the identification of signals to induce fibroblast dedifferentiation and skeletal regeneration. This regenerative response is mediated in part by BMP signaling, as is the case in mammals; however, a complete regenerative response requires the induction of a population of undifferentiated, regeneration-competent cells. These cells can be induced by signaling from limb amputation to generate blastema cells that can be grafted to the wound, as well as by signaling from a nerve and a wound epithelium to induce blastema cells from fibroblasts within the wound environment. Copyright 2009 Elsevier Inc. All rights reserved.

Slow and sustained nitric oxide releasing compounds inhibit multipotent vascular stem cell proliferation and differentiation without causing cell death

International Nuclear Information System (INIS)

Curtis, Brandon M.; Leix, Kyle Alexander; Ji, Yajing; Glaves, Richard Samuel Elliot; Ash, David E.; Mohanty, Dillip K.

2014-01-01

Highlights: • Multipotent vascular stem cells (MVSCs) proliferate and differentiate. • Nitric oxide inhibits proliferation of MVSCs. • Nitric oxide inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs). • Smooth muscle cells (SMCs) neither de-differentiate nor proliferate. - Abstract: Atherosclerosis is the leading cause of cerebral and myocardial infarction. It is believed that neointimal growth common in the later stages of atherosclerosis is a result of vascular smooth muscle cell (SMC) de-differentiation in response to endothelial injury. However, the claims of the SMC de-differentiation theory have not been substantiated by monitoring the fate of mature SMCs in response to such injuries. A recent study suggests that atherosclerosis is a consequence of multipotent vascular stem cell (MVSC) differentiation. Nitric oxide (NO) is a well-known mediator against atherosclerosis, in part because of its inhibitory effect on SMC proliferation. Using three different NO-donors, we have investigated the effects of NO on MVSC proliferation. Results indicate that NO inhibits MVSC proliferation in a concentration dependent manner. A slow and sustained delivery of NO proved to inhibit proliferation without causing cell death. On the other hand, larger, single-burst NO concentrations, inhibits proliferation, with concurrent significant cell death. Furthermore, our results indicate that endogenously produced NO inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs) and subsequently to SMC as well

Slow and sustained nitric oxide releasing compounds inhibit multipotent vascular stem cell proliferation and differentiation without causing cell death

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Curtis, Brandon M.; Leix, Kyle Alexander [Department of Chemistry, Central Michigan University, Mount Pleasant, MI 48859 (United States); Ji, Yajing [Department of Biomedical Science and Medicine, Michigan State University, East Lansing, MI 48824 (United States); Glaves, Richard Samuel Elliot [Department of Biology, Central Michigan University, Mount Pleasant, MI 48859 (United States); Ash, David E. [Department of Chemistry, Central Michigan University, Mount Pleasant, MI 48859 (United States); Mohanty, Dillip K., E-mail: Mohan1dk@cmich.edu [Department of Chemistry, Central Michigan University, Mount Pleasant, MI 48859 (United States)

2014-07-18

Highlights: • Multipotent vascular stem cells (MVSCs) proliferate and differentiate. • Nitric oxide inhibits proliferation of MVSCs. • Nitric oxide inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs). • Smooth muscle cells (SMCs) neither de-differentiate nor proliferate. - Abstract: Atherosclerosis is the leading cause of cerebral and myocardial infarction. It is believed that neointimal growth common in the later stages of atherosclerosis is a result of vascular smooth muscle cell (SMC) de-differentiation in response to endothelial injury. However, the claims of the SMC de-differentiation theory have not been substantiated by monitoring the fate of mature SMCs in response to such injuries. A recent study suggests that atherosclerosis is a consequence of multipotent vascular stem cell (MVSC) differentiation. Nitric oxide (NO) is a well-known mediator against atherosclerosis, in part because of its inhibitory effect on SMC proliferation. Using three different NO-donors, we have investigated the effects of NO on MVSC proliferation. Results indicate that NO inhibits MVSC proliferation in a concentration dependent manner. A slow and sustained delivery of NO proved to inhibit proliferation without causing cell death. On the other hand, larger, single-burst NO concentrations, inhibits proliferation, with concurrent significant cell death. Furthermore, our results indicate that endogenously produced NO inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs) and subsequently to SMC as well.

Identification of key genes and molecular mechanisms associated with dedifferentiated liposarcoma based on bioinformatic methods

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Yu H

2017-06-01

Full Text Available Hongliang Yu,1 Dong Pei,2 Longyun Chen,2 Xiaoxiang Zhou,2 Haiwen Zhu2 1Department of Radiation Oncology, Jiangsu Cancer Hospital and Jiangsu Institute of Cancer Research, The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, 2Department of Radiation Oncology, Yancheng Third People’s Hospital, Yancheng, Jiangsu, People’s Republic of China Background: Dedifferentiated liposarcoma (DDLPS is one of the most deadly types of soft tissue sarcoma. To date, there have been few studies dedicated to elucidating the molecular mechanisms behind the disease; therefore, the molecular mechanisms behind this malignancy remain largely unknown.Materials and methods: Microarray profiles of 46 DDLPS samples and nine normal fat controls were extracted from Gene Expression Omnibus (GEO. Quality control for these microarray profiles was performed before analysis. Hierarchical clustering and principal component analysis were used to distinguish the general differences in gene expression between DDLPS samples and the normal fat controls. Differentially expressed genes (DEGs were identified using the Limma package in R. Next, the enriched Gene Ontology (GO terms and Kyoto Encyclopedia of Genes and Genomes (KEGG pathways were obtained using the online tool DAVID (http://david.abcc.ncifcrf.gov/. A protein–protein interaction (PPI network was constructed using the STRING database and Cytoscape software. Furthermore, the hub genes within the PPI network were identified.Results: All 55 microarray profiles were confirmed to be of high quality. The gene expression pattern of DDLPS samples was significantly different from that of normal fat controls. In total, 700 DEGs were identified, and 83 enriched GO terms and three KEGG pathways were obtained. Specifically, within the DEGs of DDLPS samples, several pathways were identified as being significantly enriched, including the PPAR signaling pathway, cell cycle pathway, and pyruvate metabolism pathway

Rare aggressive behavior of MDM2-amplified retroperitoneal dedifferentiated liposarcoma, with brain, lung and subcutaneous metastases

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Imen Ben Salha

2016-10-01

Full Text Available Dedifferentiated liposarcoma (DDL is a histologically pleomorphic sarcoma, traditionally defined as well-differentiated liposarcoma with abrupt transition to high grade, nonlipogenic sarcoma. It can occur as part of recurrent well-differentiated liposarcoma, or may arise de novo. DDL most frequently occurs within the retroperitoneum, and while it is prone to local recurrence, it usually has a lower rate of metastasis than other pleomorphic sarcomas. We describe a case of retroperitoneal dedifferentiated liposarcoma in a 63-year-old male, who showed MDM2 amplification with fluorescence in situ hybridization, which displayed unusually aggressive behavior, with brain, lung and subcutaneous soft tissue metastases. As previous reports of metastatic liposarcoma have largely grouped DDL in with other (genetically and clinically distinct liposarcoma subtypes, we highlight and discuss the rare occurrence of brain metastasis in MDM2-amplified retroperitoneal liposarcoma.

HB-EGF is necessary and sufficient for Müller glia dedifferentiation and retina regeneration

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Wan, Jin; Ramachandran, Rajesh; Goldman, Daniel

2011-01-01

Summary Müller glia (MG) dedifferentiation into a cycling population of multipotent progenitors is crucial to zebrafish retina regeneration. The mechanisms underlying MG dedifferentiation are unknown. Here we report that heparin-binding epidermal-like growth factor (HB-EGF) is rapidly induced in MG residing at the injury site and that proHB-EGF ectodomain shedding is necessary for retina regeneration. Remarkably, HB-EGF stimulates the formation of multipotent MG-derived progenitors in the uninjured retina. We show that HB-EGF mediates its effects via an EGFR/MAPK signal transduction cascade that regulates the expression of regeneration-associated genes, like ascl1a and pax6b. We also uncover an HB-EGF/Ascl1a/Notch/hb-egfa signaling loop that helps define the zone of injury-responsive MG. Finally, we show that HB-EGF acts upstream of the Wnt/β-catenin signaling cascade that controls progenitor proliferation. These data provide a link between extracellular signaling and regeneration-associated gene expression in the injured retina and suggest strategies for stimulating retina regeneration in mammals. PMID:22340497

Dedifferentiated chondrosarcoma of the larynx: Radiological, gross, microscopic and clinical features.

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Magliocca, Kelly R; Edgar, Mark A; Corey, Amanda; Villari, Craig R

2017-10-01

Laryngeal chondrosarcoma is an uncommon malignancy with a predilection for the cricoid cartilage of adult male patients. Although rare, identification of aggressive chondrosarcoma variants, such as dedifferentiated chondrosarcoma (DDCS) may influence preoperative patient counseling, definitive surgical management, potential implementation of post-operative adjuvant therapy and prognosis. Herein we describe clinical and imaging features of laryngeal DDCS, the unique perspective of fresh and formalin fixed macroscopic examination, a spectrum of histopathologic findings, and detail the full course of the patient's disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Dedifferentiated Liposarcoma of the Retroperitoneum with Heterologous Osteosarcomatous Differentiation and a Striking Aneurysmal Bone Cyst-Like Morphology

NARCIS (Netherlands)

Van Haverbeke, Carole; Van Dorpe, Jo; Lecoutere, Evelyne; Flucke, Uta; Ferdinande, Liesbeth; Creytens, David

2017-01-01

A 69-year-old woman with a 10-year medical history of recurrent retroperitoneal dedifferentiated liposarcoma presented with a 3-cm large hemorrhagic and multicystic left-sided retroperitoneal mass. Histopathological examination of the resected specimen showed a heterogeneous, high-grade mesenchymal

Down-regulation of 21A Alu RNA as a tool to boost proliferation maintaining the tissue regeneration potential of progenitor cells

OpenAIRE

Gigoni, Arianna; Costa, Delfina; Gaetani, Massimiliano; Tasso, Roberta; Villa, Federico; Florio, Tullio; Pagano, Aldo

2016-01-01

21A is an Alu non-coding (nc) RNA transcribed by RNA polymerase (pol) III. While investigating the biological role of 21A ncRNA we documented an inverse correlation between its expression level and the rate of cell proliferation. The downregulation of this ncRNA not only caused a boost in cell proliferation, but was also associated to a transient cell dedifferentiation, suggesting a possible involvement of this RNA in cell dedifferentiation/reprogramming. In this study, we explored the possib...

Culture temperature affects redifferentiation and cartilaginous extracellular matrix formation in dedifferentiated human chondrocytes.

Science.gov (United States)

Ito, Akira; Aoyama, Tomoki; Iijima, Hirotaka; Tajino, Junichi; Nagai, Momoko; Yamaguchi, Shoki; Zhang, Xiangkai; Kuroki, Hiroshi

2015-05-01

To date, there have been few studies on how temperature affects the phenotype and metabolism of human chondrocytes. Thus, the purpose of this study was to elucidate the effects of culture temperature on chondrocyte redifferentiation and extracellular matrix (ECM) formation using dedifferentiated mature human chondrocytes in vitro. Dedifferentiated chondrocytes were cultured in a pellet culture system for up to 21 days. The pellets were randomly divided into three groups with different culture temperature (32, 37, and 41°C). Chondrocyte redifferentiation and ECM formation were evaluated by wet weight, messenger ribonucleic acid (mRNA), histological, and biochemical analyses. The results showed that the wet weight and the mRNA expressions of collagen type II A1 and cartilage oligomeric matrix protein at 37°C were higher than the corresponding values at 32°C. The histological and biochemical analyses revealed that the syntheses of type II collagen and proteoglycan were promoted at 37°C compared to those at 32°C, whereas they were considerably inhibited at 41°C. In conclusion, the results obtained herein indicated that temperature affects chondrocyte redifferentiation and ECM formation, and modulation of temperature might thus represent an advantageous means to regulate the phenotype and biosynthetic activity of chondrocytes. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Induction of neural stem cell-like cells (NSCLCs) from mouse astrocytes by Bmi1

International Nuclear Information System (INIS)

Moon, Jai-Hee; Yoon, Byung Sun; Kim, Bona; Park, Gyuman; Jung, Hye-Youn; Maeng, Isaac; Jun, Eun Kyoung; Yoo, Seung Jun; Kim, Aeree; Oh, Sejong; Whang, Kwang Youn; Kim, Hyunggee; Kim, Dong-Wook; Kim, Ki Dong; You, Seungkwon

2008-01-01

Recently, Bmi1 was shown to control the proliferation and self-renewal of neural stem cells (NSCs). In this study, we demonstrated the induction of NSC-like cells (NSCLCs) from mouse astrocytes by Bmi1 under NSC culture conditions. These NSCLCs exhibited the morphology and growth properties of NSCs, and expressed NSC marker genes, including nestin, CD133, and Sox2. In vitro differentiation of NSCLCs resulted in differentiated cell populations containing astrocytes, neurons, and oligodendrocytes. Following treatment with histone deacetylase inhibitors (trichostatin A and valproic acid), the potential of NSCLCs for proliferation, dedifferentiation, and self-renewal was significantly inhibited. Our data indicate that multipotent NSCLCs can be generated directly from astrocytes by the addition of Bmi1

Changes in tumor vascularity precede microbubble contrast accumulation deficit in the process of dedifferentiation of hepatocellular carcinoma

International Nuclear Information System (INIS)

Maruyama, Hitoshi; Takahashi, Masanori; Ishibashi, Hiroyuki; Okabe, Shinichiro; Yoshikawa, Masaharu; Yokosuka, Osamu

2010-01-01

Purpose: To elucidate the changes in tumor vascularity and microbubble accumulation on contrast-enhanced sonograms, in relation to the dedifferentiation of hepatocellular carcinoma (HCC). Materials and methods: This prospective study enrolled 10 patients with histologically proven HCC (14.4-39.0 mm, 26.1 ± 7.4) showing nodule-in-nodule appearance upon contrast-enhanced computed tomography. Contrast-enhanced ultrasound was performed by harmonic imaging under a low mechanical index (0.22-0.25) during the vascular phase (agent injection to 1 min) and late phase (15 min) following the injection of Sonazoid TM (0.0075 ml/kg). Contrast enhancement in the inner and outer nodules was assessed in comparison with that in adjacent liver parenchyma as hyper-, iso-, or hypo-enhanced. Results: Vascular-phase enhancement of all 10 inner nodules was hyper-enhanced, and that of outer nodules was hyper-enhanced in 3, iso-enhanced in 2, and hypo-enhanced in 5. Late-phase enhancement of inner nodules was hypo-enhanced in 8 and iso-enhanced in 2. Furthermore, late-phase enhancement of outer nodules was iso-enhanced in the 7 lesions that showed iso- or hypo-enhancement in the vascular phase, and hypo-enhanced in the 3 with hyper-enhancement in the vascular phase. Late-phase hypo-enhancement was significantly more frequent in the nodules showing early-phase hyper-enhancement (11/13) than in the nodules showing early-phase iso- or hypo-enhancement (0/7) in both the inner and outer nodules. Conclusion: Dedifferentiation of HCC may be accompanied by changes in tumor vascularity prior to a reduction in microbubble accumulation. Observation of the vascular phase may be more useful than late-phase imaging for the early recognition of HCC dedifferentiation when using contrast-enhanced ultrasound with Sonazoid.

Recent Advances in Intestinal Stem Cells.

Science.gov (United States)

McCabe, Laura R; Parameswaran, Narayanan

2017-09-01

The intestine is a dynamic organ with rapid stem cell division generating epithelial cells that mature and apoptose in 3-5 days. Rapid turnover maintains the epithelial barrier and homeostasis. Current insights on intestinal stem cells (ISCs) and their regulation are discussed here. The Lgr5+ ISCs maintain intestinal homeostasis by dividing asymmetrically, but also divide symmetrically to extinguish or replace ISCs. Following radiation or mucosal injury, reserve BMI1+ ISCs as well as other crypt cells can de-differentiate into Lgr5+ ISCs. ISC niche cells, including Paneth, immune and myofibroblast cells secrete factors that regulate ISC proliferation. Finally, several studies indicate that the microbiome metabolites regulate ISC growth. ISC cells can be plastic and integrate a complexity of environmental/niche cues to trigger or suppress proliferation as needed.

Sonic hedgehog promotes stem-cell potential of Mueller glia in the mammalian retina

International Nuclear Information System (INIS)

Wan Jin; Zheng Hua; Xiao Honglei; She Zhenjue; Zhou Guomin

2007-01-01

Mueller glia have been demonstrated to display stem-cell properties after retinal damage. Here, we report this potential can be regulated by Sonic hedgehog (Shh) signaling. Shh can stimulate proliferation of Mueller glia through its receptor and target gene expressed on them, furthermore, Shh-treated Mueller glia are induced to dedifferentiate by expressing progenitor-specific markers, and then adopt cell fate of rod photoreceptor. Inhibition of signaling by cyclopamine inhibits proliferation and dedifferentiation. Intraocular injection of Shh promotes Mueller glia activation in the photoreceptor-damaged retina, Shh also enhances neurogenic potential by producing more rhodopsin-positive photoreceptors from Mueller glia-derived cells. Together, these results provide evidences that Mueller glia act as potential stem cells in mammalian retina, Shh may have therapeutic effects on these cells for promoting the regeneration of retinal neurons

Sonic hedgehog promotes stem-cell potential of Mueller glia in the mammalian retina

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Jin, Wan; Hua, Zheng; Honglei, Xiao; Zhenjue, She [Department of Anatomy, Histology and Embryology, Shanghai Medical School, Fudan University, 200032 Shanghai (China); Zhou Guomin [Department of Anatomy, Histology and Embryology, Shanghai Medical School, Fudan University, 200032 Shanghai (China)], E-mail: gmzhou185@yahoo.com.cn

2007-11-16

Mueller glia have been demonstrated to display stem-cell properties after retinal damage. Here, we report this potential can be regulated by Sonic hedgehog (Shh) signaling. Shh can stimulate proliferation of Mueller glia through its receptor and target gene expressed on them, furthermore, Shh-treated Mueller glia are induced to dedifferentiate by expressing progenitor-specific markers, and then adopt cell fate of rod photoreceptor. Inhibition of signaling by cyclopamine inhibits proliferation and dedifferentiation. Intraocular injection of Shh promotes Mueller glia activation in the photoreceptor-damaged retina, Shh also enhances neurogenic potential by producing more rhodopsin-positive photoreceptors from Mueller glia-derived cells. Together, these results provide evidences that Mueller glia act as potential stem cells in mammalian retina, Shh may have therapeutic effects on these cells for promoting the regeneration of retinal neurons.

Cyclin D1 negatively regulates the expression of differentiation genes in HT-29 M6 mucus-secreting colon cancer cells.

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Mayo, Clara; Mayol, Xavier

2009-08-28

HT-29 M6 colon cancer cells differentiate to a mucus-secreting phenotype in culture. We found that the pattern of cyclin D1 expression in HT-29 M6 cells did not correlate with instances of cell proliferation but was specifically induced during a dedifferentiation process following disaggregation of epithelial cell layers, even under conditions that did not allow cell cycle reentrance. Interestingly, ectopic expression of cyclin D1 in differentiated cells led to the inhibition of the transcriptional activity of differentiation gene promoters, such as the mucin MUC1. We thus propose that the overexpression of cyclin D1 found in colon cancer favours tumour dedifferentiation as one mechanism of tumour progression.

Shh mediates PDGF-induced contractile-to-synthetic phenotypic modulation in vascular smooth muscle cells through regulation of KLF4

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Zeng, Qiu [Department of Vascular Surgery, 1st Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China); Wei, Bin [Department of Dermatology, 1st Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China); Zhao, Yu; Wang, Xuehu; Fu, Qining; Liu, Hong [Department of Vascular Surgery, 1st Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China); Li, Fenghe, E-mail: lfh_cmu@126.com [Department of Vascular Surgery, 1st Affiliated Hospital of Chongqing Medical University, Chongqing 400016 (China)

2016-07-01

Platelet-derived growth factor (PDGF) is known to induce phenotypic switching of vascular smooth muscle cells (VSMCs) from contractile to a pathological synthetic state, which played an essential role in proliferation of VSMCs. Sonic hedgehog (Shh) contributes to the proliferation of VSMCs when induced by PDGF. Here, we investigated the probable role of Shh in PDGF-induced VSMC dedifferentiation and its underlying mechanisms. We found that PDGF stimulated Shh expression in VSMCs, which was mediated by activation of PDGFRβ/ERK1/2 cell signaling pathway. Further, we found PDGF-induced VSMC phenotypic modulation was accompanied by up-regulation of Shh/Gli family zinc finger 2 (Gli2) signaling and Krüppel-like factor 4 (KLF4). When inhibited Shh in the presence of PDGF, the expressions of KLF4 and VSMC dedifferentiation markers were down-regulated and the effect of PDGF in inducing VSMC dedifferentiation was blocked. In the absence of PDGF, Shh signaling activation increased the expression of KLF4 and promoted VSMC dedifferentiation. The results indicate Shh participated in the regulation of PDGF-induced VSMC dedifferentiation. Finally, we found that KLF4 was closely involved in this process. On inhibition of KLF4, PDGF induced VSMC dedifferentiation was abrogated, even in the presence of Shh. Taken together, the results provide critical insights into the newly discovered role of Shh in phenotypic modulation of VSMCs which depends on KLF4. - Highlights: • Shh as a downstream effector of PDGF participates in PDGF-induced VSMC phenotypic modulation. • Shh can promote VSMC phenotypic switching from contractile to synthetic state. • Shh mediates VSMC phenotypic modulation through regulation of KLF4.

Shh mediates PDGF-induced contractile-to-synthetic phenotypic modulation in vascular smooth muscle cells through regulation of KLF4

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Zeng, Qiu; Wei, Bin; Zhao, Yu; Wang, Xuehu; Fu, Qining; Liu, Hong; Li, Fenghe

2016-01-01

Platelet-derived growth factor (PDGF) is known to induce phenotypic switching of vascular smooth muscle cells (VSMCs) from contractile to a pathological synthetic state, which played an essential role in proliferation of VSMCs. Sonic hedgehog (Shh) contributes to the proliferation of VSMCs when induced by PDGF. Here, we investigated the probable role of Shh in PDGF-induced VSMC dedifferentiation and its underlying mechanisms. We found that PDGF stimulated Shh expression in VSMCs, which was mediated by activation of PDGFRβ/ERK1/2 cell signaling pathway. Further, we found PDGF-induced VSMC phenotypic modulation was accompanied by up-regulation of Shh/Gli family zinc finger 2 (Gli2) signaling and Krüppel-like factor 4 (KLF4). When inhibited Shh in the presence of PDGF, the expressions of KLF4 and VSMC dedifferentiation markers were down-regulated and the effect of PDGF in inducing VSMC dedifferentiation was blocked. In the absence of PDGF, Shh signaling activation increased the expression of KLF4 and promoted VSMC dedifferentiation. The results indicate Shh participated in the regulation of PDGF-induced VSMC dedifferentiation. Finally, we found that KLF4 was closely involved in this process. On inhibition of KLF4, PDGF induced VSMC dedifferentiation was abrogated, even in the presence of Shh. Taken together, the results provide critical insights into the newly discovered role of Shh in phenotypic modulation of VSMCs which depends on KLF4. - Highlights: • Shh as a downstream effector of PDGF participates in PDGF-induced VSMC phenotypic modulation. • Shh can promote VSMC phenotypic switching from contractile to synthetic state. • Shh mediates VSMC phenotypic modulation through regulation of KLF4.

Oocyte-like cells induced from mouse spermatogonial stem cells.

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Wang, Lu; Cao, Jinping; Ji, Ping; Zhang, Di; Ma, Lianghong; Dym, Martin; Yu, Zhuo; Feng, Lixin

2012-08-06

During normal development primordial germ cells (PGCs) derived from the epiblast are the precursors of spermatogonia and oogonia. In culture, PGCs can be induced to dedifferentiate to pluripotent embryonic germ (EG) cells in the presence of various growth factors. Several recent studies have now demonstrated that spermatogonial stem cells (SSCs) can also revert back to pluripotency as embryonic stem (ES)-like cells under certain culture conditions. However, the potential dedifferentiation of SSCs into PGCs or the potential generation of oocytes from SSCs has not been demonstrated before. We report that mouse male SSCs can be converted into oocyte-like cells in culture. These SSCs-derived oocytes (SSC-Oocs) were similar in size to normal mouse mature oocytes. They expressed oocyte-specific markers and gave rise to embryos through parthenogenesis. Interestingly, the Y- and X-linked testis-specific genes in these SSC-Oocs were significantly down-regulated or turned off, while oocyte-specific X-linked genes were activated. The gene expression profile appeared to switch to that of the oocyte across the X chromosome. Furthermore, these oocyte-like cells lost paternal imprinting but acquired maternal imprinting. Our data demonstrate that SSCs might maintain the potential to be reprogrammed into oocytes with corresponding epigenetic reversals. This study provides not only further evidence for the remarkable plasticity of SSCs but also a potential system for dissecting molecular and epigenetic regulations in germ cell fate determination and imprinting establishment during gametogenesis.

Oocyte-like cells induced from mouse spermatogonial stem cells

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Wang Lu

2012-08-01

Full Text Available Abstract Background During normal development primordial germ cells (PGCs derived from the epiblast are the precursors of spermatogonia and oogonia. In culture, PGCs can be induced to dedifferentiate to pluripotent embryonic germ (EG cells in the presence of various growth factors. Several recent studies have now demonstrated that spermatogonial stem cells (SSCs can also revert back to pluripotency as embryonic stem (ES-like cells under certain culture conditions. However, the potential dedifferentiation of SSCs into PGCs or the potential generation of oocytes from SSCs has not been demonstrated before. Results We report that mouse male SSCs can be converted into oocyte-like cells in culture. These SSCs-derived oocytes (SSC-Oocs were similar in size to normal mouse mature oocytes. They expressed oocyte-specific markers and gave rise to embryos through parthenogenesis. Interestingly, the Y- and X-linked testis-specific genes in these SSC-Oocs were significantly down-regulated or turned off, while oocyte-specific X-linked genes were activated. The gene expression profile appeared to switch to that of the oocyte across the X chromosome. Furthermore, these oocyte-like cells lost paternal imprinting but acquired maternal imprinting. Conclusions Our data demonstrate that SSCs might maintain the potential to be reprogrammed into oocytes with corresponding epigenetic reversals. This study provides not only further evidence for the remarkable plasticity of SSCs but also a potential system for dissecting molecular and epigenetic regulations in germ cell fate determination and imprinting establishment during gametogenesis.

Potential in a single cancer cell to produce heterogeneous morphology, radiosensitivity and gene expression

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Ban, Sadayuki; Ishikawa, Ken-ichi; Kawai, Seiko; Koyama-Saegusa, Kumiko; Ishikawa, Atsuko; Imai, Takashi; Shimada, Yutaka; Inazawa, Johji

2005-01-01

Morphologically heterogeneous colonies were formed from a cultured cell line (KYSE70) established from one human esophageal carcinoma tissue. Two subclones were separated from a single clone (clone 13) of KYSE70 cells. One subclone (clone 13-3G) formed mainly mounding colonies and the other (clone 13-6G) formed flat, diffusive colonies. X-irradiation stimulated the cells to dedifferentiate from the mounding state to the flat, diffusive state. Clone 13-6G cells were more radiosensitive than the other 3 cell lines. Clustering analysis for gene expression level by oligonucleotide microarray demonstrated that in the radiosensitive clone 13-6G cells, expression of genes involved in cell adhesion was upregulated, but genes involved in the response to DNA damage stimulus were downregulated. The data demonstrated that a single cancer cell had the potential to produce progeny heterogeneous in terms of morphology, radiation sensitivity and gene expression, and irradiation enhanced the dedifferentiation of cancer cells. (author)

Critical role of endoglin in tumor cell plasticity of Ewing sarcoma and melanoma

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Pardali, E.; Schaft, van der D.W.J.; Wiercinska, E.; Gorter, A.; Hogendoorn, P.C.W.; Griffioen, A.W.; Dijke, ten P.

2011-01-01

Tumor cell plasticity enables certain types of highly malignant tumor cells to dedifferentiate and engage a plastic multipotent embryonic-like phenotype, which enables them to ‘adapt’ during tumor progression and escape conventional therapeutic strategies. This plastic phenotype of aggressive cancer

Replacement of Lost Lgr5-Positive Stem Cells through Plasticity of Their Enterocyte-Lineage Daughters.

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Tetteh, Paul W; Basak, Onur; Farin, Henner F; Wiebrands, Kay; Kretzschmar, Kai; Begthel, Harry; van den Born, Maaike; Korving, Jeroen; de Sauvage, Frederic; van Es, Johan H; van Oudenaarden, Alexander; Clevers, Hans

2016-02-04

Intestinal crypts display robust regeneration upon injury. The relatively rare secretory precursors can replace lost stem cells, but it is unknown if the abundant enterocyte progenitors that express the Alkaline phosphate intestinal (Alpi) gene also have this capacity. We created an Alpi-IRES-CreERT2 (Alpi(CreER)) knockin allele for lineage tracing. Marked clones consist entirely of enterocytes and are all lost from villus tips within days. Genetic fate-mapping of Alpi(+) cells before or during targeted ablation of Lgr5-expressing stem cells generated numerous long-lived crypt-villus "ribbons," indicative of dedifferentiation of enterocyte precursors into Lgr5(+) stems. By single-cell analysis of dedifferentiating enterocytes, we observed the generation of Paneth-like cells and proliferative stem cells. We conclude that the highly proliferative, short-lived enterocyte precursors serve as a large reservoir of potential stem cells during crypt regeneration. Copyright © 2016 Elsevier Inc. All rights reserved.

Graft Growth and Podocyte Dedifferentiation in Donor-Recipient Size Mismatch Kidney Transplants.

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Müller-Deile, Janina; Bräsen, Jan Hinrich; Pollheimer, Marion; Ratschek, Manfred; Haller, Hermann; Pape, Lars; Schiffer, Mario

2017-10-01

Kidney transplantation is the treatment choice for patients with end-stage renal diseases. Because of good long-term outcome, pediatric kidney grafts are also accepted for transplantation in adult recipients despite a significant mismatch in body size and age between donor and recipient. These grafts show a remarkable ability of adaptation to the recipient body and increase in size in a very short period, presumably as an adaptation to hyperfiltration. We investigated renal graft growth as well as glomerular proliferation and differentiation markers Kiel-67, paired box gene 2 and Wilms tumor protein (WT1) expression in control biopsies from different transplant constellations: infant donor for infant recipient, infant donor for child recipient, infant donor for adult recipient, child donor for child recipient, child donor for adult recipient, and adult donor for an adult recipient. We detected a significant increase in kidney graft size after transplantation in all conditions with a body size mismatch, which was most prominent when an infant donated for a child. Podocyte WT1 expression was comparable in different transplant conditions, whereas a significant increase in WT1 expression could be detected in parietal epithelial cells, when a kidney graft from a child was transplanted into an adult. In kidney grafts that were relatively small for the recipients, we could detect reexpression of podocyte paired box gene 2. Moreover, the proliferation marker Kiel-67 was expressed in glomerular cells in grafts that increased in size after transplantation. Kidney grafts rapidly adapt to the recipient size after transplantation if they are transplanted in a body size mismatch constellation. The increase in transplant size is accompanied by an upregulation of proliferation and dedifferentiation markers in podocytes. The different examined conditions exclude hormonal factors as the key trigger for this growth so that most likely hyperfiltration is the key trigger inducing the

MicroRNAs: From Female Fertility, Germ Cells, and Stem Cells to Cancer in Humans

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Irma Virant-Klun

2016-01-01

Full Text Available MicroRNAs are a family of naturally occurring small noncoding RNA molecules that play an important regulatory role in gene expression. They are suggested to regulate a large proportion of protein encoding genes by mediating the translational suppression and posttranscriptional control of gene expression. Recent findings show that microRNAs are emerging as important regulators of cellular differentiation and dedifferentiation, and are deeply involved in developmental processes including human preimplantation development. They keep a balance between pluripotency and differentiation in the embryo and embryonic stem cells. Moreover, it became evident that dysregulation of microRNA expression may play a fundamental role in progression and dissemination of different cancers including ovarian cancer. The interest is still increased by the discovery of exosomes, that is, cell-derived vesicles, which can carry different proteins but also microRNAs between different cells and are involved in cell-to-cell communication. MicroRNAs, together with exosomes, have a great potential to be used for prognosis, therapy, and biomarkers of different diseases including infertility. The aim of this review paper is to summarize the existent knowledge on microRNAs related to female fertility and cancer: from primordial germ cells and ovarian function, germinal stem cells, oocytes, and embryos to embryonic stem cells.

Dedifferentiated chondrosarcoma: A survival analysis of 159 cases from the SEER database (2001-2011).

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Strotman, Patrick K; Reif, Taylor J; Kliethermes, Stephanie A; Sandhu, Jasmin K; Nystrom, Lukas M

2017-08-01

Dedifferentiated chondrosarcoma is a rare malignancy with reported 5-year overall survival rates ranging from 7% to 24%. The purpose of this investigation is to determine the overall survival of dedifferentiated chondrosarcoma in a modern patient series and how it is impacted by patient demographics, tumor characteristics, and surgical treatment factors. This is a retrospective review of the Surveillance, Epidemiology, and End Results (SEER) database from 2001 to 2011. Kaplan Meier analyses were used for overall and disease-specific survival. Univariable and multivariable cox regression models were used to identify prognostic factors. Five year overall- and disease-specific survival was 18% (95% CI: 12-26%) and 28% (95% CI: 18-37%), respectively. Individuals with extremity tumors had a worse prognosis than individuals with a primary tumor in the chest wall or axial skeleton (HR 0.20, 95% CI: 0.07-0.56; P = 0.002 and HR 0.60, 95% CI: 0.36-0.99; P = 0.04, respectively). Patients with AJCC stage III or IV disease (HR 2.51, 95% CI: 1.50-4.20; P = 0.001), tumors larger than 8 cm (HR 2.17, 95% CI: 1.11-4.27; P = 0.046), metastatic disease at diagnosis (HR 3.25, 95% CI: 1.98-5.33; P chondrosarcoma is poor with a 5-year overall survival of 18%. Patients with a primary tumor located in the chest wall had a better prognosis. Tumors larger than 8 cm, presence of metastases at diagnosis, and treatment without surgical resection were significant predictors of mortality. © 2017 Wiley Periodicals, Inc.

Osteogenic differentiation in dedifferentiated liposarcoma: a study of 36 cases in comparison to the cases without ossification.

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Yamashita, Kyoko; Kohashi, Kenichi; Yamada, Yuichi; Ishii, Takeaki; Nishida, Yoshihiro; Urakawa, Hiroshi; Ito, Ichiro; Takahashi, Mitsuru; Inoue, Takeshi; Ito, Masafumi; Ohara, Yuuki; Oda, Yoshinao; Toyokuni, Shinya

2018-04-01

Ossification is found occasionally in dedifferentiated liposarcoma (DDLPS). The aims of this study were to elucidate whether the formed bone tissue is usually produced by tumour cells or by reactive non-neoplastic cells, and to reveal the clinicopathological characteristics of DDLPS with ossification. We examined 36 cases of ossified DDLPS by comparing them to 31 cases of non-ossified DDLPS. MDM2 amplification was confirmed in osteocytes and/or osteoblastic cells in all but one ossified DDLPS cases (27 of 28) using fluorescence in-situ hybridisation, although the morphological impression of ossification appeared to be mainly metaplastic (27 of 36) or high-grade osteosarcoma-like (six of 36). The bone tissue was often formed predominantly at the periphery of the DDLPS area near the well-differentiated liposarcoma component (18 of 36), and an organised structure such as bone marrow-like differentiation was not uncommon (12 of 36). According to a modified French Fédération Nationale des Centers de Lutte Contre le Cancer (FNCLCC) grading system, ossified DDLPS tended to be lower grade than non-ossified DDLPS (mean grade: 1.88 and 2.15, respectively). Ossification in DDLPS was associated significantly with shorter local recurrence-free survival by multivariate analysis (P = 0.02347), but metaplastic-appearing ossification tended to be associated with longer overall survival (P = 0.1400). The bone tissue formed in DDLPS was mainly neoplastic regardless of its morphology and maturity, which highlighted the osteogenic differentiation of the tumour cells. DDLPS patients with osteogenic differentiation tended to suffer from earlier local recurrences, which did not necessarily lead to poor life outcomes. © 2017 John Wiley & Sons Ltd.

Rhabdoid and Undifferentiated Phenotype in Renal Cell Carcinoma: Analysis of 32 Cases Indicating a Distinctive Common Pathway of Dedifferentiation Frequently Associated With SWI/SNF Complex Deficiency.

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Agaimy, Abbas; Cheng, Liang; Egevad, Lars; Feyerabend, Bernd; Hes, Ondřej; Keck, Bastian; Pizzolitto, Stefano; Sioletic, Stefano; Wullich, Bernd; Hartmann, Arndt

2017-02-01

Undifferentiated (anaplastic) and rhabdoid cell features are increasingly recognized as adverse prognostic findings in renal cell carcinoma (RCC), but their molecular pathogenesis has not been studied sufficiently. Recent studies identified alterations in the Switch Sucrose nonfermentable (SWI/SNF) chromatin remodeling complex as molecular mechanisms underlying dedifferentiation and rhabdoid features in carcinomas of different organs. We herein have analyzed 32 undifferentiated RCCs having in common an undifferentiated (anaplastic) phenotype, prominent rhabdoid features, or both, irrespective of the presence or absence of conventional RCC component. Cases were stained with 6 SWI/SNF pathway members (SMARCB1, SMARCA2, SMARCA4, ARID1A, SMARCC1, and SMARCC2) in addition to conventional RCC markers. Patients were 20 males and 12 females aged 32 to 85 years (mean, 59). A total of 22/27 patients with known stage presented with ≥pT3. A differentiated component varying from microscopic to major component was detected in 20/32 cases (16 clear cell and 2 cases each chromophobe and papillary RCC). The undifferentiated component varied from rhabdoid dyscohesive cells to large epithelioid to small monotonous anaplastic cells. Variable loss of at least 1 SWI/SNF complex subunit was noted in the undifferentiated/rhabdoid component of 21/32 cases (65%) compared with intact or reduced expression in the differentiated component. A total of 15/17 patients (88%) with follow-up died of metastatic disease (mostly within 1 y). Only 2 patients were disease free at last follow-up (1 and 6 y). No difference in survival, age distribution, or sex was observed between the SWI/SNF-deficient and the SWI/SNF-intact group. This is the first study exploring the role of SWI/SNF deficiency as a potential mechanism underlying undifferentiated and rhabdoid phenotype in RCC. Our results highlight the association between the aggressive rhabdoid phenotype and the SWI/SNF complex deficiency, consistent

Tumor budding cells, cancer stem cells and epithelial-mesenchymal transition-type cells in pancreatic cancer

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Karamitopoulou, Eva

2013-01-01

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers with a 5-year survival rate of less than 5%. Moreover, PDAC escapes early detection and resists treatment. Multiple combinations of genetic alterations are known to occur in PDAC including mutational activation of KRAS, inactivation of p16/CDKN2A and SMAD4 (DPC4) and dysregulation of PTEN/PI3K/AKT signaling. Through their interaction with Wingless-INT pathway, the downstream molecules of these pathways have been implicated in the promotion of epithelial–mesenchymal transition (EMT). Emerging evidence has demonstrated that cancer stem cells (CSCs), small populations of which have been identified in PDAC, and EMT-type cells play critical roles in drug resistance, invasion, and metastasis in pancreatic cancer. EMT may be histologically represented by the presence of tumor budding which is described as the occurrence of single tumor cells or small clusters (<5) of dedifferentiated cells at the invasive front of gastrointestinal (including colorectal, oesophageal, gastric, and ampullary) carcinomas and is linked to poor prognosis. Tumor budding has recently been shown to occur frequently in PDAC and to be associated with adverse clinicopathological features and decreased disease-free and overall survival. The aim of this review is to present a short overview on the morphological and molecular aspects that underline the relationship between tumor budding cells, CSCs, and EMT-type cells in PDAC.

Tumor budding cells, cancer stem cells and epithelial-mesenchymal transition-type cells in pancreatic cancer.

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Karamitopoulou, Eva

2012-01-01

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers with a 5-year survival rate of less than 5%. Moreover, PDAC escapes early detection and resists treatment. Multiple combinations of genetic alterations are known to occur in PDAC including mutational activation of KRAS, inactivation of p16/CDKN2A and SMAD4 (DPC4) and dysregulation of PTEN/PI3K/AKT signaling. Through their interaction with Wingless-INT pathway, the downstream molecules of these pathways have been implicated in the promotion of epithelial-mesenchymal transition (EMT). Emerging evidence has demonstrated that cancer stem cells (CSCs), small populations of which have been identified in PDAC, and EMT-type cells play critical roles in drug resistance, invasion, and metastasis in pancreatic cancer. EMT may be histologically represented by the presence of tumor budding which is described as the occurrence of single tumor cells or small clusters (<5) of dedifferentiated cells at the invasive front of gastrointestinal (including colorectal, oesophageal, gastric, and ampullary) carcinomas and is linked to poor prognosis. Tumor budding has recently been shown to occur frequently in PDAC and to be associated with adverse clinicopathological features and decreased disease-free and overall survival. The aim of this review is to present a short overview on the morphological and molecular aspects that underline the relationship between tumor budding cells, CSCs, and EMT-type cells in PDAC.

Tumor Budding Cells, Cancer Stem Cells and Epithelial-Mesenchymal Transition-type Cells in Pancreatic Cancer

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Eva eKaramitopoulou

2013-01-01

Full Text Available Pancreatic ductal adenocarcinoma (PDAC is one of the most lethal cancers with a 5-year survival rate of less than 5%. Moreover, PDAC escapes early detection and resists treatment. Multiple combinations of genetic alterations are known to occur in PDAC including mutational activation of KRAS, inactivation of p16/CDKN2A and SMAD4 (DPC4 and dysregulation of PTEN/PI3K/AKT signaling. Through their interaction with WNT pathway, the downstream molecules of these pathways have been implicated in the promotion of epithelial-mesenchymal transition (EMT. Emerging evidence has demonstrated that cancer stem cells (CSCs, small populations of which have been identified in PDAC, and EMT-type cells play critical roles in drug resistance, invasion and metastasis in pancreatic cancer. EMT may be histologically represented by the presence of tumor budding which is described as the occurrence of single tumor cells or small clusters (<5 of dedifferentiated cells at the invasive front of gastrointestinal (including colorectal, oesophageal, gastric and ampullary carcinomas and is linked to poor prognosis. Tumor budding has recently been shown to occur frequently in PDAC and to be associated with adverse clinicopathological features and decreased disease-free and overall survival. The aim of this review is to present a short overview on the morphological and molecular aspects that underline the relationship between tumor budding cells, CSCs and EMT-type cells in PDAC.

One-stage focal cartilage defect treatment with bone marrow mononuclear cells and chondrocytes leads to better macroscopic cartilage regeneration compared to microfracture in goats

NARCIS (Netherlands)

Bekkers, J.E.J.; Creemers, L.B.; Tsuchida, A.I.; van Rijen, M.H.P.; Custers, R.J.H.; Dhert, W.J.A.; Saris, Daniël B.F.

2013-01-01

Objective The combination of chondrocytes and mononuclear fraction (MNF) cells might solve the expansion induced dedifferentiation problem of reimplanted cells in autologous chondrocytes implantation as sufficient cells would be available for direct, one-stage, implantation. Earlier in vitro work

Graft Growth and Podocyte Dedifferentiation in Donor-Recipient Size Mismatch Kidney Transplants

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Janina Müller-Deile, MD

2017-10-01

Full Text Available Background. Kidney transplantation is the treatment choice for patients with end-stage renal diseases. Because of good long-term outcome, pediatric kidney grafts are also accepted for transplantation in adult recipients despite a significant mismatch in body size and age between donor and recipient. These grafts show a remarkable ability of adaptation to the recipient body and increase in size in a very short period, presumably as an adaptation to hyperfiltration. Methods. We investigated renal graft growth as well as glomerular proliferation and differentiation markers Kiel-67, paired box gene 2 and Wilms tumor protein (WT1 expression in control biopsies from different transplant constellations: infant donor for infant recipient, infant donor for child recipient, infant donor for adult recipient, child donor for child recipient, child donor for adult recipient, and adult donor for an adult recipient. Results. We detected a significant increase in kidney graft size after transplantation in all conditions with a body size mismatch, which was most prominent when an infant donated for a child. Podocyte WT1 expression was comparable in different transplant conditions, whereas a significant increase in WT1 expression could be detected in parietal epithelial cells, when a kidney graft from a child was transplanted into an adult. In kidney grafts that were relatively small for the recipients, we could detect reexpression of podocyte paired box gene 2. Moreover, the proliferation marker Kiel-67 was expressed in glomerular cells in grafts that increased in size after transplantation. Conclusions. Kidney grafts rapidly adapt to the recipient size after transplantation if they are transplanted in a body size mismatch constellation. The increase in transplant size is accompanied by an upregulation of proliferation and dedifferentiation markers in podocytes. The different examined conditions exclude hormonal factors as the key trigger for this growth so that

Influence of epidermal growth factor (EGF) and hydrocortisone on the co-culture of mature adipocytes and endothelial cells for vascularized adipose tissue engineering.

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Huber, Birgit; Czaja, Alina Maria; Kluger, Petra Juliane

2016-05-01

The composition of vascularized adipose tissue is still an ongoing challenge as no culture medium is available to supply adipocytes and endothelial cells appropriately. Endothelial cell medium is typically supplemented with epidermal growth factor (EGF) as well as hydrocortisone (HC). The effect of EGF on adipocytes is discussed controversially. Some studies say it inhibits adipocyte differentiation while others reported of improved adipocyte lipogenesis. HC is known to have lipolytic activities, which might result in mature adipocyte dedifferentiation. In this study, we evaluated the influence of EGF and HC on the co-culture of endothelial cells and mature adipocytes regarding their cell morphology and functionality. We showed in mono-culture that high levels of HC promoted dedifferentiation and proliferation of mature adipocytes, whereas EGF seemed to have no negative influence. Endothelial cells kept their typical cobblestone morphology and showed a proliferation rate comparable to the control independent of EGF and HC concentration. In co-culture, HC promoted dedifferentiation of mature adipocytes, which was shown by a higher glycerol release. EGF had no negative impact on adipocyte morphology. No negative impact on endothelial cell morphology and functionality could be seen with reduced EGF and HC supplementation in co-culture with mature adipocytes. Taken together, our results demonstrate that reduced levels of HC are needed for co-culturing mature adipocytes and endothelial cells. In co-culture, EGF had no influence on mature adipocytes. Therefore, for the composition of vascularized adipose tissue constructs, the media with low levels of HC and high or low levels of EGF can be used. © 2016 International Federation for Cell Biology.

Using Haworthia Cultured Cells as an Aid in Teaching Botany

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Majumdar, Shyamal K.; Castellano, John M.

1977-01-01

Callus induction from species of Haworthia can be done quickly in the laboratory with minimal equipment to study tissue dedifferentiation and cellular redifferentiation. It is shown that the cultured cell can also be used to study and evaluate the effects of various mutagens, carcinogens, and pesticides in controlled environments. (Author/MA)

Uncovering inherent cellular plasticity of multiciliated ependyma leading to ventricular wall transformation and hydrocephalus.

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Abdi, Khadar; Lai, Chun-Hsiang; Paez-Gonzalez, Patricia; Lay, Mark; Pyun, Joon; Kuo, Chay T

2018-04-25

Specialized, differentiated cells often perform unique tasks that require them to maintain a stable phenotype. Multiciliated ependymal cells (ECs) are unique glial cells lining the brain ventricles, important for cerebral spinal fluid circulation. While functional ECs are needed to prevent hydrocephalus, they have also been reported to generate new neurons: whether ECs represent a stable cellular population remains unclear. Via a chemical screen we found that mature ECs are inherently plastic, with their multiciliated state needing constant maintenance by the Foxj1 transcription factor, which paradoxically is rapidly turned over by the ubiquitin-proteasome system leading to cellular de-differentiation. Mechanistic analyses revealed a novel NF-κB-independent IKK2 activity stabilizing Foxj1 in mature ECs, and we found that known IKK2 inhibitors including viruses and growth factors robustly induced Foxj1 degradation, EC de-differentiation, and hydrocephalus. Although mature ECs upon de-differentiation can divide and regenerate multiciliated ECs, we did not detect evidence supporting EC's neurogenic potential.

Platelet-Rich Plasma Increases the Levels of Catabolic Molecules and Cellular Dedifferentiation in the Meniscus of a Rabbit Model

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Hye-Rim Lee

2016-01-01

Full Text Available Despite the susceptibility to frequent intrinsic and extrinsic injuries, especially in the inner zone, the meniscus does not heal spontaneously owing to its poor vascularity. In this study, the effect of platelet-rich plasma (PRP, containing various growth factors, on meniscal mechanisms was examined under normal and post-traumatic inflammatory conditions. Isolated primary meniscal cells of New Zealand white (NZW rabbits were incubated for 3, 10, 14 and 21 days with PRP(−, 10% PRP (PRP(+, IL(+ or IL(+PRP(+. The meniscal cells were collected and examined using reverse-transcription polymerase chain reaction (RT-PCR. Culture media were examined by immunoblot analyses for matrix metalloproteinases (MMP catabolic molecules. PRP containing growth factors improved the cellular viability of meniscal cells in a concentration-dependent manner at Days 1, 4 and 7. However, based on RT-PCR, meniscal cells demonstrated dedifferentiation, along with an increase in type I collagen in the PRP(+ and in IL(+PRP(+. In PRP(+, the aggrecan expression levels were lower than in the PRP(− until Day 21. The protein levels of MMP-1 and MMP-3 were higher in each PRP group, i.e., PRP(+ and IL(+PRP(+, at each culture time. A reproducible 2-mm circular defect on the meniscus of NZW rabbit was used to implant fibrin glue (control or PRP in vivo. After eight weeks, the lesions in the control and PRP groups were occupied with fibrous tissue, but not with meniscal cells. This study shows that PRP treatment of the meniscus results in an increase of catabolic molecules, especially those related to IL-1α-induced inflammation, and that PRP treatment for an in vivo meniscus injury accelerates fibrosis, instead of meniscal cartilage.

Slow-Adhering Stem Cells Derived from Injured Skeletal Muscle Have Improved Regenerative Capacity

Science.gov (United States)

2011-08-01

stress urinary incontinence . Urology 2006, 68:449–454 15. Chermansky CJ, Tarin T, Kwon DD, Jankowski RJ, Cannon TW, de Groat WC, Huard J, Chancellor...from control noninjured muscle. These data suggest that traumatic injury may modify stem cell characteristics through trophic factors and improve the...alter the microenvironment of resident muscle cells (ie, stimu- lating cell dedifferentiation on various trophic factors )20,21 and result in profound

Electrochemical cell structure including an ionomeric barrier

Science.gov (United States)

Lambert, Timothy N.; Hibbs, Michael

2017-06-20

An apparatus includes an electrochemical half-cell comprising: an electrolyte, an anode; and an ionomeric barrier positioned between the electrolyte and the anode. The anode may comprise a multi-electron vanadium phosphorous alloy, such as VP.sub.x, wherein x is 1-5. The electrochemical half-cell is configured to oxidize the vanadium and phosphorous alloy to release electrons. A method of mitigating corrosion in an electrochemical cell includes disposing an ionomeric barrier in a path of electrolyte or ion flow to an anode and mitigating anion accumulation on the surface of the anode.

Retinal pigment epithelium culture;a potential source of retinal stem cells.

Science.gov (United States)

Akrami, Hassan; Soheili, Zahra-Soheila; Khalooghi, Keynoush; Ahmadieh, Hamid; Rezaie-Kanavi, Mojgan; Samiei, Shahram; Davari, Malihe; Ghaderi, Shima; Sanie-Jahromi, Fatemeh

2009-07-01

To establish human retinal pigment epithelial (RPE) cell culture as a source for cell replacement therapy in ocular diseases. Human cadaver globes were used to isolate RPE cells. Each globe was cut into several pieces of a few millimeters in size. After removing the sclera and choroid, remaining tissues were washed in phosphate buffer saline and RPE cells were isolated using dispase enzyme solution and cultured in Dulbecco's Modified Eagle's Medium: Nutrient Mixture F-12 supplemented with 10% fetal calf serum. Primary cultures of RPE cells were established and spheroid colonies related to progenitor/stem cells developed in a number of cultures. The colonies included purely pigmented or mixed pigmented and non-pigmented cells. After multiple cellular passages, several types of photoreceptors and neural-like cells were detected morphologically. Cellular plasticity in RPE cell cultures revealed promising results in terms of generation of stem/progenitor cells from human RPE cells. Whether the spheroids and neural-like retinal cells were directly derived from retinal stem cells or offspring of trans-differentiating or de-differentiating RPE cells remains to be answered.

Epigenetic modulation of dental pulp stem cells: implications for regenerative endodontics.

Science.gov (United States)

Duncan, H F; Smith, A J; Fleming, G J P; Cooper, P R

2016-05-01

Dental pulp stem cells (DPSCs) offer significant potential for use in regenerative endodontics, and therefore, identifying cellular regulators that control stem cell fate is critical to devising novel treatment strategies. Stem cell lineage commitment and differentiation are regulated by an intricate range of host and environmental factors of which epigenetic influence is considered vital. Epigenetic modification of DNA and DNA-associated histone proteins has been demonstrated to control cell phenotype and regulate the renewal and pluripotency of stem cell populations. The activities of the nuclear enzymes, histone deacetylases, are increasingly being recognized as potential targets for pharmacologically inducing stem cell differentiation and dedifferentiation. Depending on cell maturity and niche in vitro, low concentration histone deacetylase inhibitor (HDACi) application can promote dedifferentiation of several post-natal and mouse embryonic stem cell populations and conversely increase differentiation and accelerate mineralization in DPSC populations, whilst animal studies have shown an HDACi-induced increase in stem cell marker expression during organ regeneration. Notably, both HDAC and DNA methyltransferase inhibitors have also been demonstrated to dramatically increase the reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) for use in regenerative therapeutic procedures. As the regulation of cell fate will likely remain the subject of intense future research activity, this review aims to describe the current knowledge relating to stem cell epigenetic modification, focusing on the role of HDACi on alteration of DPSC phenotype, whilst presenting the potential for therapeutic application as part of regenerative endodontic regimens. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

DNA Methyltransferases Modulate Hepatogenic Lineage Plasticity of Mesenchymal Stromal Cells

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Chien-Wei Lee

2017-07-01

Full Text Available The irreversibility of developmental processes in mammalian cells has been challenged by rising evidence that de-differentiation of hepatocytes occurs in adult liver. However, whether reversibility exists in mesenchymal stromal cell (MSC-derived hepatocytes (dHeps remains elusive. In this study, we find that hepatogenic differentiation (HD of MSCs is a reversible process and is modulated by DNA methyltransferases (DNMTs. DNMTs are regulated by transforming growth factor β1 (TGFβ1, which in turn controls hepatogenic differentiation and de-differentiation. In addition, a stepwise reduction in TGFβ1 concentrations in culture media increases DNMT1 and decreases DNMT3 in primary hepatocytes (Heps and confers Heps with multi-differentiation potentials similarly to MSCs. Hepatic lineage reversibility of MSCs and lineage conversion of Heps are regulated by DNMTs in response to TGFβ1. This previously unrecognized TGFβ1-DNMTs-MSC-HD axis may further increase the understanding the normal and pathological processes in the liver, as well as functions of MSCs after transplantation to treat liver diseases.

Case report 141

International Nuclear Information System (INIS)

Bonfiglio, M.; Platz, C.E.

1981-01-01

The case reported represents another example of dedifferentiation occurring in a benign cartilaginous tumor of bone. Osteosarcoma and fibrosarcoma are generally considered to represent the more malignant counterparts of such dedifferentiation, but studies recently have indicated that malignant fibrous histiocytoma may indeed be a common feature in such dedifferentiated lesions. It is stressed that lesions previously designated histologically as malignant giant cell tumor, when dedifferentiation occurs, may represent a special variant of malignant fibrous histiocytoma. (orig./MG)

In Vitro and In Vivo Hepatic Differentiation of Adult Somatic Stem Cells and Extraembryonic Stem Cells for Treating End Stage Liver Diseases

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Chenxia Hu

2015-01-01

Full Text Available The shortage of liver donors is a major handicap that prevents most patients from receiving liver transplantation and places them on a waiting list for donated liver tissue. Then, primary hepatocyte transplantation and bioartificial livers have emerged as two alternative treatments for these often fatal diseases. However, another problem has emerged. Functional hepatocytes for liver regeneration are in short supply, and they will dedifferentiate immediately in vitro after they are isolated from liver tissue. Alternative stem-cell-based therapeutic strategies, including hepatic stem cells (HSCs, embryonic stem cells (ESCs, induced pluripotent stem cells (iPSCs, and mesenchymal stem cells (MSCs, are more promising, and more attention has been devoted to these approaches because of the high potency and proliferation ability of the cells. This review will focus on the general characteristics and the progress in hepatic differentiation of adult somatic stem cells and extraembryonic stem cells in vitro and in vivo for the treatment of end stage liver diseases. The hepatic differentiation of stem cells would offer an ideal and promising source for cell therapy and tissue engineering for treating liver diseases.

Dedifferentiated Liposarcoma in the Retroperitoneum in an Atomic Bomb Survivor: Report of a Case

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Yukio Nakamura

2008-09-01

Full Text Available A 76-year-old Japanese man was admitted to Kosei-Nenkin Hospital (Osaka, Japan in November 2006; his chief complaint was a 10-kg loss in body weight over 3 months prior to admission. Abdominal computed tomography (CT and dynamic magnetic resonance imaging (MRI showed three masses in the retroperitoneum. The patient subsequently underwent surgery. The final histopathological diagnosis of tumors 1 and 2 was malignant fibrous histiocytoma of the retroperitoneum, and tumor 3 was a well-differentiated liposarcoma. By the presence of the liposarcoma, tumor 1 and 2 were thought to be the dedifferentiated areas of liposarcomas. At the age of 16, the patient had been exposed to radiation from the atomic bomb at Hiroshima towards the end of the Second World War. We postulate that in this case, radiation from the atomic bomb may have played an important role in the development of the sarcomas.

In-vitro chondrogenic potential of synovial stem cells and chondrocytes allocated for autologous chondrocyte implantation

DEFF Research Database (Denmark)

Kubosch, Eva Johanna; Heidt, Emanuel; Niemeyer, Philipp

2017-01-01

Purpose: The use of passaged chondrocytes is the current standard for autologous chondrocyte implantation (ACI). De-differentiation due to amplification and donor site morbidity are known drawbacks highlighting the need for alternative cell sources. Methods: Via clinically validated flow cytometry...... analysis, we compared the expression of human stem cell and cartilage markers (collagen type 2 (Col2), aggrecan (ACAN), CD44) of chondrocytes (CHDR), passaged chondrocytes for ACI (CellGenix™), bone marrow derived mesenchymal stem cells (BMSC), and synovial derived stem cells (SDSC). Results: Primary...

FGF-2b and h-PL Transform Duct and Non-Endocrine Human Pancreatic Cells into Endocrine Insulin Secreting Cells by Modulating Differentiating Genes

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Giulia Donadel

2017-10-01

Full Text Available Background: Diabetes mellitus (DM is a multifactorial disease orphan of a cure. Regenerative medicine has been proposed as novel strategy for DM therapy. Human fibroblast growth factor (FGF-2b controls β-cell clusters via autocrine action, and human placental lactogen (hPL-A increases functional β-cells. We hypothesized whether FGF-2b/hPL-A treatment induces β-cell differentiation from ductal/non-endocrine precursor(s by modulating specific genes expression. Methods: Human pancreatic ductal-cells (PANC-1 and non-endocrine pancreatic cells were treated with FGF-2b plus hPL-A at 500 ng/mL. Cytofluorimetry and Immunofluorescence have been performed to detect expression of endocrine, ductal and acinar markers. Bromodeoxyuridine incorporation and annexin-V quantified cells proliferation and apoptosis. Insulin secretion was assessed by RIA kit, and electron microscopy analyzed islet-like clusters. Results: Increase in PANC-1 duct cells de-differentiation into islet-like aggregates was observed after FGF-2b/hPL-A treatment showing ultrastructure typical of islets-aggregates. These clusters, after stimulation with FGF-2b/hPL-A, had significant (p < 0.05 increase in insulin, C-peptide, pancreatic and duodenal homeobox 1 (PDX-1, Nkx2.2, Nkx6.1, somatostatin, glucagon, and glucose transporter 2 (Glut-2, compared with control cells. Markers of PANC-1 (Cytokeratin-19, MUC-1, CA19-9 were decreased (p < 0.05. These aggregates after treatment with FGF-2b/hPL-A significantly reduced levels of apoptosis. Conclusions: FGF-2b and hPL-A are promising candidates for regenerative therapy in DM by inducing de-differentiation of stem cells modulating pivotal endocrine genes.

Activation of Pax7-positive cells in a non-contractile tissue contributes to regeneration of myogenic tissues in the electric fish S. macrurus.

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Christopher M Weber

Full Text Available The ability to regenerate tissues is shared across many metazoan taxa, yet the type and extent to which multiple cellular mechanisms come into play can differ across species. For example, urodele amphibians can completely regenerate all lost tissues, including skeletal muscles after limb amputation. This remarkable ability of urodeles to restore entire limbs has been largely linked to a dedifferentiation-dependent mechanism of regeneration. However, whether cell dedifferentiation is the fundamental factor that triggers a robust regeneration capacity, and whether the loss or inhibition of this process explains the limited regeneration potential in other vertebrates is not known. Here, we studied the cellular mechanisms underlying the repetitive regeneration of myogenic tissues in the electric fish S. macrurus. Our in vivo microinjection studies of high molecular weight cell lineage tracers into single identified adult myogenic cells (muscle or noncontractile muscle-derived electrocytes revealed no fragmentation or cellularization proximal to the amputation plane. In contrast, ultrastructural and immunolabeling studies verified the presence of myogenic stem cells that express the satellite cell marker Pax7 in mature muscle fibers and electrocytes of S. macrurus. These data provide the first example of Pax-7 positive muscle stem cells localized within a non-contractile electrogenic tissue. Moreover, upon amputation, Pax-7 positive cells underwent a robust replication and were detected exclusively in regions that give rise to myogenic cells and dorsal spinal cord components revealing a regeneration process in S. macrurus that is dependent on the activation of myogenic stem cells for the renewal of both skeletal muscle and the muscle-derived electric organ. These data are consistent with the emergent concept in vertebrate regeneration that different tissues provide a distinct progenitor cell population to the regeneration blastema, and these

The transcription factor Nerfin-1 prevents reversion of neurons into neural stem cells.

Science.gov (United States)

Froldi, Francesca; Szuperak, Milan; Weng, Chen-Fang; Shi, Wei; Papenfuss, Anthony T; Cheng, Louise Y

2015-01-15

Cellular dedifferentiation is the regression of a cell from a specialized state to a more multipotent state and is implicated in cancer. However, the transcriptional network that prevents differentiated cells from reacquiring stem cell fate is so far unclear. Neuroblasts (NBs), the Drosophila neural stem cells, are a model for the regulation of stem cell self-renewal and differentiation. Here we show that the Drosophila zinc finger transcription factor Nervous fingers 1 (Nerfin-1) locks neurons into differentiation, preventing their reversion into NBs. Following Prospero-dependent neuronal specification in the ganglion mother cell (GMC), a Nerfin-1-specific transcriptional program maintains differentiation in the post-mitotic neurons. The loss of Nerfin-1 causes reversion to multipotency and results in tumors in several neural lineages. Both the onset and rate of neuronal dedifferentiation in nerfin-1 mutant lineages are dependent on Myc- and target of rapamycin (Tor)-mediated cellular growth. In addition, Nerfin-1 is required for NB differentiation at the end of neurogenesis. RNA sequencing (RNA-seq) and chromatin immunoprecipitation (ChIP) analysis show that Nerfin-1 administers its function by repression of self-renewing-specific and activation of differentiation-specific genes. Our findings support the model of bidirectional interconvertibility between neural stem cells and their post-mitotic progeny and highlight the importance of the Nerfin-1-regulated transcriptional program in neuronal maintenance. © 2015 Froldi et al.; Published by Cold Spring Harbor Laboratory Press.

Age-related dedifferentiation of cognitive and motor slowing: Insight from the comparison of Hick-Hyman and Fitts’ laws

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Rita eSleimen-Malkoun

2013-10-01

Full Text Available The present study aimed to determine whether the general slowing hypothesis could be extended to the motor domain by comparing cognitive and motor age-related slowing. To achieve this objective, we compared the slopes of Hick-Hyman’s law and Fitts’ law, in young and older adults. The general hypothesis was that, due to the dedifferentiation of cognitive and motor neural resources during aging, the slopes of Hick-Hyman's law and Fitts’ law should become closer, if not similar, in older adults. Ten young adults (mean age = 26 ± 3 years and fourteen older adults (mean age = 78 ± 7 years participated in the experiment. They had to perform a discrete rapid-aiming task and a reaction time task. In the aiming task, five ID levels were used (from 3 to 7 bits by increments of 1.0 bit. Task difficulty was scaled via the manipulation of target distance from home position. In the reaction time task, 5 IDs were selected: 0, 1, 2, 3 and 4 bits, with incompatible S-R associations. Reaction time and movement times were recorded. Efficiency and Brinley regression functions were calculated. Age-related slowing ratios were estimated. Response times increased in both tasks in older adults. The slopes of Hick-Hyman’s law and Fitts’ law were steeper in older adults than in young participants. In young participants, the slope of Hick-Hyman’s law was smaller than that of Fitts’ law. In older adults, no difference was found. Slowing ratios observed in both tasks were equivalent. The present results extended the general slowing hypothesis to the motor domain. They suggested that, due to dedifferentiation of cognitive and motor neural resources, decrease in processing speed acts as a common cause to behavioral slowing in both cognitive and motor tasks.

Biology of Schwann cells.

Science.gov (United States)

Kidd, Grahame J; Ohno, Nobuhiko; Trapp, Bruce D

2013-01-01

The fundamental roles of Schwann cells during peripheral nerve formation and regeneration have been recognized for more than 100 years, but the cellular and molecular mechanisms that integrate Schwann cell and axonal functions continue to be elucidated. Derived from the embryonic neural crest, Schwann cells differentiate into myelinating cells or bundle multiple unmyelinated axons into Remak fibers. Axons dictate which differentiation path Schwann cells follow, and recent studies have established that axonal neuregulin1 signaling via ErbB2/B3 receptors on Schwann cells is essential for Schwann cell myelination. Extracellular matrix production and interactions mediated by specific integrin and dystroglycan complexes are also critical requisites for Schwann cell-axon interactions. Myelination entails expansion and specialization of the Schwann cell plasma membrane over millimeter distances. Many of the myelin-specific proteins have been identified, and transgenic manipulation of myelin genes have provided novel insights into myelin protein function, including maintenance of axonal integrity and survival. Cellular events that facilitate myelination, including microtubule-based protein and mRNA targeting, and actin based locomotion, have also begun to be understood. Arguably, the most remarkable facet of Schwann cell biology, however, is their vigorous response to axonal damage. Degradation of myelin, dedifferentiation, division, production of axonotrophic factors, and remyelination all underpin the substantial regenerative capacity of the Schwann cells and peripheral nerves. Many of these properties are not shared by CNS fibers, which are myelinated by oligodendrocytes. Dissecting the molecular mechanisms responsible for the complex biology of Schwann cells continues to have practical benefits in identifying novel therapeutic targets not only for Schwann cell-specific diseases but other disorders in which axons degenerate. Copyright © 2013 Elsevier B.V. All rights

Establishment and Analysis of Cancer Stem-Like and Non-Cancer Stem-Like Clone Cells from the Human Colon Cancer Cell Line SW480.

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Akari Takaya

Full Text Available Human cancer stem-like cells (CSCs/cancer-initiating cells (CICs can be isolated as side population (SP cells, aldehyde dehydrogenase high (ALDHhigh cells or cell surface marker-positive cells including CD44+ cells and CD133+ cells. CSCs/CICs and non-CSCs/CICs are unstable in in vitro culture, and CSCs/CICs can differentiate into non-CSCs/CICs and some non-CSCs/CICs can dedifferentiate into CSCs/CICs. Therefore, experiments using a large amount of CSCs/CICs are technically very difficult. In this study, we isolated single cell clones from SP cells and main population (MP cells derived from the human colon cancer cell line SW480. SP analysis revealed that SP clone cells had relatively high percentages of SP cells, whereas MP clone cells showed very few SP cells, and the phenotypes were sustainable for more than 2 months of in vitro culture. Xenograft transplantation revealed that SP clone cells have higher tumor-initiating ability than that of MP clone cells and SP clone cell showed higher chemo-resistance compared with MP clone cells. These results indicate that SP clone cells derived from SW480 cells are enriched with CSCs/CICs, whereas MP clone cells are pure non-CSCs/CICs. SP clone cells and MP clone cells are a very stable in vitro CSC/CIC-enriched and non-CSC/CIC model for further analysis.

Establishment and Analysis of Cancer Stem-Like and Non-Cancer Stem-Like Clone Cells from the Human Colon Cancer Cell Line SW480.

Science.gov (United States)

Takaya, Akari; Hirohashi, Yoshihiko; Murai, Aiko; Morita, Rena; Saijo, Hiroshi; Yamamoto, Eri; Kubo, Terufumi; Nakatsugawa, Munehide; Kanaseki, Takayuki; Tsukahara, Tomohide; Tamura, Yasuaki; Takemasa, Ichiro; Kondo, Toru; Sato, Noriyuki; Torigoe, Toshihiko

2016-01-01

Human cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) can be isolated as side population (SP) cells, aldehyde dehydrogenase high (ALDHhigh) cells or cell surface marker-positive cells including CD44+ cells and CD133+ cells. CSCs/CICs and non-CSCs/CICs are unstable in in vitro culture, and CSCs/CICs can differentiate into non-CSCs/CICs and some non-CSCs/CICs can dedifferentiate into CSCs/CICs. Therefore, experiments using a large amount of CSCs/CICs are technically very difficult. In this study, we isolated single cell clones from SP cells and main population (MP) cells derived from the human colon cancer cell line SW480. SP analysis revealed that SP clone cells had relatively high percentages of SP cells, whereas MP clone cells showed very few SP cells, and the phenotypes were sustainable for more than 2 months of in vitro culture. Xenograft transplantation revealed that SP clone cells have higher tumor-initiating ability than that of MP clone cells and SP clone cell showed higher chemo-resistance compared with MP clone cells. These results indicate that SP clone cells derived from SW480 cells are enriched with CSCs/CICs, whereas MP clone cells are pure non-CSCs/CICs. SP clone cells and MP clone cells are a very stable in vitro CSC/CIC-enriched and non-CSC/CIC model for further analysis.

Novel therapeutic strategies to target leukemic cells that hijack compartmentalized continuous hematopoietic stem cell niches.

Science.gov (United States)

Hira, Vashendriya V V; Van Noorden, Cornelis J F; Carraway, Hetty E; Maciejewski, Jaroslaw P; Molenaar, Remco J

2017-08-01

Acute myeloid leukemia and acute lymphoblastic leukemia cells hijack hematopoietic stem cell (HSC) niches in the bone marrow and become leukemic stem cells (LSCs) at the expense of normal HSCs. LSCs are quiescent and resistant to chemotherapy and can cause relapse of the disease. HSCs in niches are needed to generate blood cell precursors that are committed to unilineage differentiation and eventually production of mature blood cells, including red blood cells, megakaryocytes, myeloid cells and lymphocytes. Thus far, three types of HSC niches are recognized: endosteal, reticular and perivascular niches. However, we argue here that there is only one type of HSC niche, which consists of a periarteriolar compartment and a perisinusoidal compartment. In the periarteriolar compartment, hypoxia and low levels of reactive oxygen species preserve the HSC pool. In the perisinusoidal compartment, hypoxia in combination with higher levels of reactive oxygen species enables proliferation of progenitor cells and their mobilization into the circulation. Because HSC niches offer protection to LSCs against chemotherapy, we review novel therapeutic strategies to inhibit homing of LSCs in niches for the prevention of dedifferentiation of leukemic cells into LSCs and to stimulate migration of leukemic cells out of niches. These strategies enhance differentiation and proliferation and thus sensitize leukemic cells to chemotherapy. Finally, we list clinical trials of therapies that tackle LSCs in HSC niches to circumvent their protection against chemotherapy. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Comparative analysis in continuous expansion of bovine and human primary nucleus pulposus cells for tissue repair applications

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DH Rosenzweig

2017-03-01

Full Text Available Autologous NP cell implantation is a potential therapeutic avenue for intervertebral disc (IVD degeneration. However, monolayer expansion of cells isolated from surgical samples may negatively impact matrix production by way of dedifferentiation. Previously, we have used a continuous expansion culture system to successfully preserve a chondrocyte phenotype. In this work, we hypothesised that continuous expansion culture could also preserve nucleus pulposus (NP phenotype. We confirmed that serial passaging drove NP dedifferentiation by significantly decreasing collagen type II, aggrecan and chondroadherin (CHAD gene expression, compared to freshly isolated cells. Proliferation, gene expression profile and matrix production in both culture conditions were compared using primary bovine NP cells. Both standard culture and continuous culture produced clinically relevant cell populations. However, continuous culture cells maintained significantly higher collagen type II, aggrecan and CHAD transcript expression levels. Also, continuous expansion cells generated greater amounts of proteoglycan, collagen type II and aggrecan protein deposition in pellet cultures. To our surprise, continuous expansion of human intervertebral disc cells – isolated from acute herniation tissue – produced less collagen type II, aggrecan and CHAD genes and proteins, compared to standard culture. Also, continuous culture of cells isolated from young non-degenerate tissue did not preserve gene and protein expression, compared to standard culture. These data indicated that primary bovine and human NP cells responded differently to continuous culture, where the positive effects observed for bovine cells did not translate to human cells. Therefore, caution must be exercised when choosing animal models and cell sources for pre-clinical studies.

Pathologic bladder microenvironment attenuates smooth muscle differentiation of skin derived precursor cells: implications for tissue regeneration.

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Cornelia Tolg

Full Text Available Smooth muscle cell containing organs (bladder, heart, blood vessels are damaged by a variety of pathological conditions necessitating surgery or organ replacement. Currently, regeneration of contractile tissues is hampered by lack of functional smooth muscle cells. Multipotent skin derived progenitor cells (SKPs can easily be isolated from adult skin and can be differentiated in vitro into contractile smooth muscle cells by exposure to FBS. Here we demonstrate an inhibitory effect of a pathologic contractile organ microenvironment on smooth muscle cell differentiation of SKPs. In vivo, urinary bladder strain induces microenvironmental changes leading to de-differentiation of fully differentiated bladder smooth muscle cells. Co-culture of SKPs with organoids isolated from ex vivo stretched bladders or exposure of SKPs to diffusible factors released by stretched bladders (e.g. bFGF suppresses expression of smooth muscle markers (alpha SMactin, calponin, myocardin, myosin heavy chain as demonstrated by qPCR and immunofluorescent staining. Rapamycin, an inhibitor of mTOR signalling, previously observed to prevent bladder strain induced de-differentiation of fully differentiated smooth muscle cells in vitro, inhibits FBS-induced smooth muscle cell differentiation of undifferentiated SKPs. These results suggest that intended precursor cell differentiation may be paradoxically suppressed by the disease context for which regeneration may be required. Organ-specific microenvironment contexts, particularly prevailing disease, may play a significant role in modulating or attenuating an intended stem cell phenotypic fate, possibly explaining the variable and inefficient differentiation of stem cell constructs in in vivo settings. These observations must be considered in drafting any regeneration strategies.

LGR5 and Nanog identify stem cell signature of pancreas beta cells which initiate pancreatic cancer.

Science.gov (United States)

Amsterdam, Abraham; Raanan, Calanit; Schreiber, Letizia; Polin, Nava; Givol, David

2013-04-05

Pancreas cancer, is the fourth leading cause of cancer death but its cell of origin is controversial. We compared the localization of stem cells in normal and cancerous pancreas using antibodies to the stem cell markers Nanog and LGR5. Here we show, for the first time, that LGR5 is expressed in normal pancreas, exclusively in the islets of Langerhans and it is co-localized, surprisingly, with Nanog and insulin in clusters of beta cells. In cancerous pancreas Nanog and LGR5 are expressed in the remaining islets and in all ductal cancer cells. We observed insulin staining among the ductal cancer cells, but not in metastases. This indicates that the islet's beta cells, expressing LGR5 and Nanog markers are the initiating cells of pancreas cancer, which migrated from the islets to form the ductal cancerous tissue, probably after mutation and de-differentiation. This discovery may facilitate treatment of this devastating cancer. Copyright © 2013 Elsevier Inc. All rights reserved.

Defining the cellular environment in the organ of Corti following extensive hair cell loss: a basis for future sensory cell replacement in the Cochlea.

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Ruth R Taylor

Full Text Available BACKGROUND: Following the loss of hair cells from the mammalian cochlea, the sensory epithelium repairs to close the lesions but no new hair cells arise and hearing impairment ensues. For any cell replacement strategy to be successful, the cellular environment of the injured tissue has to be able to nurture new hair cells. This study defines characteristics of the auditory sensory epithelium after hair cell loss. METHODOLOGY/PRINCIPAL FINDINGS: Studies were conducted in C57BL/6 and CBA/Ca mice. Treatment with an aminoglycoside-diuretic combination produced loss of all outer hair cells within 48 hours in both strains. The subsequent progressive tissue re-organisation was examined using immunohistochemistry and electron microscopy. There was no evidence of significant de-differentiation of the specialised columnar supporting cells. Kir4.1 was down regulated but KCC4, GLAST, microtubule bundles, connexin expression patterns and pathways of intercellular communication were retained. The columnar supporting cells became covered with non-specialised cells migrating from the outermost region of the organ of Corti. Eventually non-specialised, flat cells replaced the columnar epithelium. Flat epithelium developed in distributed patches interrupting regions of columnar epithelium formed of differentiated supporting cells. Formation of the flat epithelium was initiated within a few weeks post-treatment in C57BL/6 mice but not for several months in CBA/Ca's, suggesting genetic background influences the rate of re-organisation. CONCLUSIONS/SIGNIFICANCE: The lack of dedifferentiation amongst supporting cells and their replacement by cells from the outer side of the organ of Corti are factors that may need to be considered in any attempt to promote endogenous hair cell regeneration. The variability of the cellular environment along an individual cochlea arising from patch-like generation of flat epithelium, and the possible variability between individuals

Memory reactivation in healthy aging: evidence of stimulus-specific dedifferentiation.

Science.gov (United States)

St-Laurent, Marie; Abdi, Hervé; Bondad, Ashley; Buchsbaum, Bradley R

2014-03-19

We investigated how aging affects the neural specificity of mental replay, the act of conjuring up past experiences in one's mind. We used functional magnetic resonance imaging (fMRI) and multivariate pattern analysis to quantify the similarity between brain activity elicited by the perception and memory of complex multimodal stimuli. Young and older human adults viewed and mentally replayed short videos from long-term memory while undergoing fMRI. We identified a wide array of cortical regions involved in visual, auditory, and spatial processing that supported stimulus-specific representation at perception as well as during mental replay. Evidence of age-related dedifferentiation was subtle at perception but more salient during mental replay, and age differences at perception could not account for older adults' reduced neural reactivation specificity. Performance on a post-scan recognition task for video details correlated with neural reactivation in young but not in older adults, indicating that in-scan reactivation benefited post-scan recognition in young adults, but that some older adults may have benefited from alternative rehearsal strategies. Although young adults recalled more details about the video stimuli than older adults on a post-scan recall task, patterns of neural reactivation correlated with post-scan recall in both age groups. These results demonstrate that the mechanisms supporting recall and recollection are linked to accurate neural reactivation in both young and older adults, but that age affects how efficiently these mechanisms can support memory's representational specificity in a way that cannot simply be accounted for by degraded sensory processes.

Age-Dependent Schwann Cell Phenotype Regulation Following Peripheral Nerve Injury.

Science.gov (United States)

Chen, Wayne A; Luo, T David; Barnwell, Jonathan C; Smith, Thomas L; Li, Zhongyu

2017-12-01

Schwann cells are integral to the regenerative capacity of the peripheral nervous system, which declines after adolescence. The mechanisms underlying this decline are poorly understood. This study sought to compare the protein expression of Notch, c-Jun, and Krox-20 after nerve crush injury in adolescent and young adult rats. We hypothesized that these Schwann cell myelinating regulatory factors are down-regulated after nerve injury in an age-dependent fashion. Adolescent (2 months old) and young adult (12 months old) rats (n = 48) underwent sciatic nerve crush injury. Protein expression of Notch, c-Jun, and Krox-20 was quantified by Western blot analysis at 1, 3, and 7 days post-injury. Functional recovery was assessed in a separate group of animals (n = 8) by gait analysis (sciatic functional index) and electromyography (compound motor action potential) over an 8-week post-injury period. Young adult rats demonstrated a trend of delayed onset of the dedifferentiating regulatory factors, Notch and c-Jun, corresponding to the delayed functional recovery observed in young adult rats compared to adolescent rats. Compound motor action potential area was significantly greater in adolescent rats relative to young adult rats, while amplitude and velocity trended toward statistical significance. The process of Schwann cell dedifferentiation following peripheral nerve injury shows different trends with age. These trends of delayed onset of key regulatory factors responsible for Schwann cell myelination may be one of many possible factors mediating the significant differences in functional recovery between adolescent and young adult rats following peripheral nerve injury.

Glioblastoma Stem Cells Respond to Differentiation Cues but Fail to Undergo Commitment and Terminal Cell-Cycle Arrest

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Helena Carén

2015-11-01

Full Text Available Glioblastoma (GBM is an aggressive brain tumor whose growth is driven by stem cell-like cells. BMP signaling triggers cell-cycle exit and differentiation of GBM stem cells (GSCs and, therefore, might have therapeutic value. However, the epigenetic mechanisms that accompany differentiation remain poorly defined. It is also unclear whether cell-cycle arrest is terminal. Here we find only a subset of GSC cultures exhibit astrocyte differentiation in response to BMP. Although overtly differentiated non-cycling astrocytes are generated, they remain vulnerable to cell-cycle re-entry and fail to appropriately reconfigure DNA methylation patterns. Chromatin accessibility mapping identified loci that failed to alter in response to BMP and these were enriched in SOX transcription factor-binding motifs. SOX transcription factors, therefore, may limit differentiation commitment. A similar propensity for cell-cycle re-entry and de-differentiation was observed in GSC-derived oligodendrocyte-like cells. These findings highlight significant obstacles to BMP-induced differentiation as therapy for GBM.

Lutein Inhibits the Migration of Retinal Pigment Epithelial Cells via Cytosolic and Mitochondrial Akt Pathways (Lutein Inhibits RPE Cells Migration

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Ching-Chieh Su

2014-08-01

Full Text Available During the course of proliferative vitreoretinopathy (PVR, the retinal pigment epithelium (RPE cells will de-differentiate, proliferate, and migrate onto the surfaces of the sensory retina. Several studies have shown that platelet-derived growth factor (PDGF can induce migration of RPE cells via an Akt-related pathway. In this study, the effect of lutein on PDGF-BB-induced RPE cells migration was examined using transwell migration assays and Western blot analyses. We found that both phosphorylation of Akt and mitochondrial translocation of Akt in RPE cells induced by PDGF-BB stimulation were suppressed by lutein. Furthermore, the increased migration observed in RPE cells with overexpressed mitochondrial Akt could also be suppressed by lutein. Our results demonstrate that lutein can inhibit PDGF-BB induced RPE cells migration through the inhibition of both cytoplasmic and mitochondrial Akt activation.

Changes in the expression of collagen genes show two stages in chondrocyte differentiation in vitro

OpenAIRE

1988-01-01

This report deals with the quantitation of both mRNA and transcription activity of type I collagen gene and of three cartilage-specific collagens (types II, IX, and X) during in vitro differentiation of chick chondrocytes. Differentiation was obtained by transferal to suspension culture of dedifferentiated cells passaged for 3 wk as adherent cells. The type I collagen mRNA, highly represented in the dedifferentiated cells, rapidly decreased during chondrocyte differentiation. On the contrary,...

Bone Morphogenetic Protein-Induced Msx1 and Msx2 Inhibit Myocardin-Dependent Smooth Muscle Gene Transcription▿

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Hayashi, Ken'ichiro; Nakamura, Seiji; Nishida, Wataru; Sobue, Kenji

2006-01-01

During the onset and progression of atherosclerosis, the vascular smooth muscle cell (VSMC) phenotype changes from differentiated to dedifferentiated, and in some cases, this change is accompanied by osteogenic transition, resulting in vascular calcification. One characteristic of dedifferentiated VSMCs is the down-regulation of smooth muscle cell (SMC) marker gene expression. Bone morphogenetic proteins (BMPs), which are involved in the induction of osteogenic gene ex...

The cancer paradigms of mammalian regeneration: can mammals regenerate as amphibians?

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Sarig, Rachel; Tzahor, Eldad

2017-04-01

Regeneration in mammals is restricted to distinct tissues and occurs mainly by expansion and maturation of resident stem cells. During regeneration, even subtle mutations in the proliferating cells may cause a detrimental effect by eliciting abnormal differentiation or malignant transformation. Indeed, cancer in mammals has been shown to arise through deregulation of stem cells maturation, which often leads to a differentiation block and cell transformation. In contrast, lower organisms such as amphibians retain a remarkable regenerative capacity in various organs, which occurs via de- and re-differentiation of mature cells. Interestingly, regenerating amphibian cells are highly resistant to oncogenic transformation. Therapeutic approaches to improve mammalian regeneration mainly include stem-cell transplantations; but, these have proved unsuccessful in non-regenerating organs such as the heart. A recently developed approach is to induce de-differentiation of mature cardiomyocytes using factors that trigger their re-entry into the cell cycle. This novel approach raises numerous questions regarding the balance between transformation and regeneration induced by de-differentiation of mature mammalian somatic cells. Can this balance be controlled artificially? Do de-differentiated cells acquire the protection mechanisms seen in regenerating cells of lower organisms? Is this model unique to the cardiac tissue, which rarely develops tumors? This review describes regeneration processes in both mammals and lower organisms and, particularly, the ability of regenerating cells to avoid transformation. By comparing the characteristics of mammalian embryonic and somatic cells, we discuss therapeutic strategies of using various cell populations for regeneration. Finally, we describe a novel cardiac regeneration approach and its implications for regenerative medicine. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email

Electrolytes including fluorinated solvents for use in electrochemical cells

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Tikhonov, Konstantin; Yip, Ka Ki; Lin, Tzu-Yuan

2015-07-07

Provided are electrochemical cells and electrolytes used to build such cells. The electrolytes include ion-supplying salts and fluorinated solvents capable of maintaining single phase solutions with the salts at between about -30.degree. C. to about 80.degree. C. The fluorinated solvents, such as fluorinated carbonates, fluorinated esters, and fluorinated esters, are less flammable than their non-fluorinated counterparts and increase safety characteristics of cells containing these solvents. The amount of fluorinated solvents in electrolytes may be between about 30% and 80% by weight not accounting weight of the salts. Fluorinated salts, such as fluoroalkyl-substituted LiPF.sub.6, fluoroalkyl-substituted LiBF.sub.4 salts, linear and cyclic imide salts as well as methide salts including fluorinated alkyl groups, may be used due to their solubility in the fluorinated solvents. In some embodiments, the electrolyte may also include a flame retardant, such as a phosphazene or, more specifically, a cyclic phosphazene and/or one or more ionic liquids.

Sustainable production of azadirachtin from differentiated in vitro cell lines of neem (Azadirachta indica)

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Singh, Mithilesh; Chaturvedi, Rakhi

2013-01-01

Azadirachtin has high industrial demand due to its immediate application as an ecofriendly, biodegradable biopesticide and also due to its various other significant bioactivities. To date, the only commercially feasible way to produce azadirachtin is extraction from seeds, but their availability is very limited as the tree flowers only once a year and only one-third of the fruits are collected due to operational problems. Further, due to the strict out-breeding nature of the plant, the seeds are highly heterozygous, resulting in inconsistent metabolite production. Therefore, in the present study, to achieve sustainable production of azadirachtin, dedifferentiated and redifferentiated calli derived from various explants of neem—zygotic embryo, leaf and ovary—were investigated for their potential to biosynthesize azadirachtin. High-performance liquid chromatography analysis of the in vitro cell lines showed the presence of azadirachtin in all the samples tested, the content of which in cultured cells varied with explant source and cell differentiation response. The presence of azadirachtin in samples was further confirmed by positive electrospray ionization mass spectroscopy. The zygotic embryo cultures of neem accumulated much higher amounts of azadirachtin than leaf and ovary cultures. Furthermore, organized in vitro callus cultures (redifferentiated) supported higher azadirachtin biosynthesis, while unorganized callus cultures (dedifferentiated) supported the least. The maximum azadirachtin content of 2.33 mg g−1 dry weight was obtained from redifferentiated immature zygotic embryo cultures.

Cancer stem cells and personalized cancer nanomedicine.

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Gener, Petra; Rafael, Diana Fernandes de Sousa; Fernández, Yolanda; Ortega, Joan Sayós; Arango, Diego; Abasolo, Ibane; Videira, Mafalda; Schwartz, Simo

2016-02-01

Despite the progress in cancer treatment over the past years advanced cancer is still an incurable disease. Special attention is pointed toward cancer stem cell (CSC)-targeted therapies, because this minor cell population is responsible for the treatment resistance, metastatic growth and tumor recurrence. The recently described CSC dynamic phenotype and interconversion model of cancer growth hamper even more the possible success of current cancer treatments in advanced cancer stages. Accordingly, CSCs can be generated through dedifferentiation processes from non-CSCs, in particular, when CSC populations are depleted after treatment. In this context, the use of targeted CSC nanomedicines should be considered as a promising tool to increase CSC sensitivity and efficacy of specific anti-CSC therapies.

Neural stem cell-encoded temporal patterning delineates an early window of malignant susceptibility in Drosophila.

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Narbonne-Reveau, Karine; Lanet, Elodie; Dillard, Caroline; Foppolo, Sophie; Chen, Ching-Huan; Parrinello, Hugues; Rialle, Stéphanie; Sokol, Nicholas S; Maurange, Cédric

2016-06-14

Pediatric neural tumors are often initiated during early development and can undergo very rapid transformation. However, the molecular basis of this early malignant susceptibility remains unknown. During Drosophila development, neural stem cells (NSCs) divide asymmetrically and generate intermediate progenitors that rapidly differentiate in neurons. Upon gene inactivation, these progeny can dedifferentiate and generate malignant tumors. Here, we find that intermediate progenitors are prone to malignancy only when born during an early window of development while expressing the transcription factor Chinmo, and the mRNA-binding proteins Imp/IGF2BP and Lin-28. These genes compose an oncogenic module that is coopted upon dedifferentiation of early-born intermediate progenitors to drive unlimited tumor growth. In late larvae, temporal transcription factor progression in NSCs silences the module, thereby limiting mitotic potential and terminating the window of malignant susceptibility. Thus, this study identifies the gene regulatory network that confers malignant potential to neural tumors with early developmental origins.

Insulin-like growth factor-1 signaling in renal cell carcinoma

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Tracz, Adam F.; Szczylik, Cezary; Porta, Camillo; Czarnecka, Anna M.

2016-01-01

Renal cell carcinoma (RCC) incidence is highest in highly developed countries and it is the seventh most common neoplasm diagnosed. RCC management include nephrectomy and targeted therapies. Type 1 insulin-like growth factor (IGF-1) pathway plays an important role in cell proliferation and apoptosis resistance. IGF-1 and insulin share overlapping downstream signaling pathways in normal and cancer cells. IGF-1 receptor (IGF1R) stimulation may promote malignant transformation promoting cell proliferation, dedifferentiation and inhibiting apoptosis. Clear cell renal cell carcinoma (ccRCC) patients with IGF1R overexpression have 70 % increased risk of death compared to patients who had tumors without IGF1R expression. IGF1R signaling deregulation may results in p53, WT, BRCA1, VHL loss of function. RCC cells with high expression of IGF1R are more resistant to chemotherapy than cells with low expression. Silencing of IGF1R increase the chemosensitivity of ccRCC cells and the effect is greater in VHL mutated cells. Understanding the role of IGF-1 signaling pathway in RCC may result in development of new targeted therapeutic interventions. First preclinical attempts with anti-IGF-1R monoclonal antibodies or fragment antigen-binding (Fab) fragments alone or in combination with an mTOR inhibitor were shown to inhibit in vitro growth and reduced the number of colonies formed by of RCC cells

Evaluation of RPE65, CRALBP, VEGF, CD68, and tyrosinase gene expression in human retinal pigment epithelial cells cultured on amniotic membrane.

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Akrami, Hassan; Soheili, Zahra-Soheila; Sadeghizadeh, Majid; Khalooghi, Keynoush; Ahmadieh, Hamid; Kanavi, Mojgan Rezaie; Samiei, Shahram; Pakravesh, Jalil

2011-06-01

The retinal pigment epithelium (RPE) plays a key role in the maintenance of the normal functions of the retina. Tissue engineering using amniotic membrane as a substrate to culture RPE cells may provide a promising new strategy to replace damaged RPE. We established a method of culturing RPE cells over the amniotic membrane as a support for their growth and transplantation. The transcription of specific genes involved in cellular function of native RPE, including RPE65, CRALBP, VEGF, CD68, and tyrosinase, were then measured using quantitative real-time PCR. Data showed a considerable increase in transcription of RPE65, CD68, and VEGF in RPE cells cultured on amniotic membrane. The amounts of CRALBP and tyrosinase transcripts were not affected. This may simply indicate that amniotic membrane restricted dedifferentiation of RPE cells in culture. The results suggest that amniotic membrane may be considered as an elective biological substrate for RPE cell culture.

The influence of rAAV2-mediated SOX2 delivery into neonatal and adult human RPE cells; a comparative study.

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Ezati, Razie; Etemadzadeh, Azadeh; Soheili, Zahra-Soheila; Samiei, Shahram; Ranaei Pirmardan, Ehsan; Davari, Malihe; Najafabadi, Hoda Shams

2018-02-01

Cell replacement is a promising therapy for degenerative diseases like age-related macular degeneration (AMD). Since the human retina lacks regeneration capacity, much attention has been directed toward persuading for cells that can differentiate into retinal neurons. In this report, we have investigated reprogramming of the human RPE cells and concerned the effect of donor age on the cellular fate as a critical determinant in reprogramming competence. We evaluated the effect of SOX2 over-expression in human neonatal and adult RPE cells in cultures. The coding region of human SOX2 gene was cloned into adeno-associated virus (AAV2) and primary culture of human neonatal/adult RPE cells were infected by recombinant virus. De-differentiation of RPE to neural/retinal progenitor cells was investigated by quantitative real-time PCR and ICC for neural/retinal progenitor cells' markers. Gene expression analysis showed 80-fold and 12-fold over-expression for SOX2 gene in infected neonatal and adult hRPE cells, respectively. The fold of increase for Nestin in neonatal and adult hRPE cells was 3.8-fold and 2.5-fold, respectively. PAX6 expression was increased threefold and 2.5-fold in neonatal/adult treated cultures. Howbeit, we could not detect rhodopsin, and CHX10 expression in neonatal hRPE cultures and expression of rhodopsin in adult hRPE cells. Results showed SOX2 induced human neonatal/adult RPE cells to de-differentiate toward retinal progenitor cells. However, the increased number of PAX6, CHX10, Thy1, and rhodopsin positive cells in adult hRPE treated cultures clearly indicated the considerable generation of neuro-retinal terminally differentiated cells. © 2017 Wiley Periodicals, Inc.

Human airway xenograft models of epithelial cell regeneration

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Puchelle Edith

2000-10-01

Full Text Available Abstract Regeneration and restoration of the airway epithelium after mechanical, viral or bacterial injury have a determinant role in the evolution of numerous respiratory diseases such as chronic bronchitis, asthma and cystic fibrosis. The study in vivo of epithelial regeneration in animal models has shown that airway epithelial cells are able to dedifferentiate, spread, migrate over the denuded basement membrane and progressively redifferentiate to restore a functional respiratory epithelium after several weeks. Recently, human tracheal xenografts have been developed in immunodeficient severe combined immunodeficiency (SCID and nude mice. In this review we recall that human airway cells implanted in such conditioned host grafts can regenerate a well-differentiated and functional human epithelium; we stress the interest in these humanized mice in assaying candidate progenitor and stem cells of the human airway mucosa.

Plasma Cell Neoplasms (Including Multiple Myeloma)—Health Professional Version

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There are several types of plasma cell neoplasms, including monoclonal gammopathy of undetermined significance (MGUS), isolated plasmacytoma of the bone, extramedullary plasmacytoma, and multiple myeloma. Find evidence-based information on plasma cell neoplasms treatment, research, and statistics.

Extract of mouse embryonic stem cells induces the expression of pluripotency genes in human adipose tissue-derived stem cells.

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Salehi, Paria Motamen; Foroutan, Tahereh; Javeri, Arash; Taha, Masoumeh Fakhr

2017-11-01

In some previous studies, the extract of embryonic carcinoma cells (ECCs) and embryonic stem cells (ESCs) have been used to reprogram somatic cells to more dedifferentiated state. The aim of this study was to investigate the effect of mouse ESCs extract on the expression of some pluripotency markers in human adipose tissue-derived stem cells (ADSCs). Human ADSCs were isolated from subcutaneous abdominal adipose tissue and characterized by flow cytometric analysis for the expression of some mesenchymal stem cell markers and adipogenic and osteogenic differentiation. Frequent freeze-thaw technique was used to prepare cytoplasmic extract of ESCs. Plasma membranes of the ADSCs were reversibly permeabilized by streptolysin-O (SLO). Then the permeabilized ADSCs were incubated with the ESC extract and cultured in resealing medium. After reprogramming, the expression of some pluripotency genes was evaluated by RT-PCR and quantitative real-time PCR (qPCR) analyses. Third-passaged ADSCs showed a fibroblast-like morphology and expressed mesenchymal stem cell markers. They also showed adipogenic and osteogenic differentiation potential. QPCR analysis revealed a significant upregulation in the expression of some pluripotency genes including OCT4 , SOX2 , NANOG , REX1 and ESG1 in the reprogrammed ADSCs compared to the control group. These findings showed that mouse ESC extract can be used to induce reprogramming of human ADSCs. In fact, this method is applicable for reprogramming of human adult stem cells to a more pluripotent sate and may have a potential in regenerative medicine.

Featured Article: Isolation, characterization, and cultivation of human hepatocytes and non-parenchymal liver cells

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Pfeiffer, Elisa; Kegel, Victoria; Zeilinger, Katrin; Hengstler, Jan G; Nüssler, Andreas K; Seehofer, Daniel

2015-01-01

Primary human hepatocytes (PHH) are considered to be the gold standard for in vitro testing of xenobiotic metabolism and hepatotoxicity. However, PHH cultivation in 2D mono-cultures leads to dedifferentiation and a loss of function. It is well known that hepatic non-parenchymal cells (NPC), such as Kupffer cells (KC), liver endothelial cells (LEC), and hepatic stellate cells (HSC), play a central role in the maintenance of PHH functions. The aims of the present study were to establish a protocol for the simultaneous isolation of human PHH and NPC from the same tissue specimen and to test their suitability for in vitro co-culture. Human PHH and NPC were isolated from tissue obtained by partial liver resection by a two-step EDTA/collagenase perfusion technique. The obtained cell fractions were purified by Percoll density gradient centrifugation. KC, LEC, and HSC contained in the NPC fraction were separated using specific adherence properties and magnetic activated cell sorting (MACS®). Identified NPC revealed a yield of 1.9 × 106 KC, 2.7 × 105 LEC and 4.7 × 105 HSC per gram liver tissue, showing viabilities >90%. Characterization of these NPC showed that all populations went through an activation process, which influenced the cell fate. The activation of KC strongly depended on the tissue quality and donor anamnesis. KC became activated in culture in association with a loss of viability within 4–5 days. LEC lost specific features during culture, while HSC went through a transformation process into myofibroblasts. The testing of different culture conditions for HSC demonstrated that they can attenuate, but not prevent dedifferentiation in vitro. In conclusion, the method described allows the isolation and separation of PHH and NPC in high quality and quantity from the same donor. PMID:25394621

Dopamine D2 Receptor-Mediated Regulation of Pancreatic β Cell Mass

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Daisuke Sakano

2016-07-01

Full Text Available Understanding the molecular mechanisms that regulate β cell mass and proliferation is important for the treatment of diabetes. Here, we identified domperidone (DPD, a dopamine D2 receptor (DRD2 antagonist that enhances β cell mass. Over time, islet β cell loss occurs in dissociation cultures, and this was inhibited by DPD. DPD increased proliferation and decreased apoptosis of β cells through increasing intracellular cAMP. DPD prevented β cell dedifferentiation, which together highly contributed to the increased β cell mass. DRD2 knockdown phenocopied the effects of domperidone and increased the number of β cells. Drd2 overexpression sensitized the dopamine responsiveness of β cells and increased apoptosis. Further analysis revealed that the adenosine agonist 5′-N-ethylcarboxamidoadenosine, a previously identified promoter of β cell proliferation, acted with DPD to increase the number of β cells. In humans, dopamine also modulates β cell mass through DRD2 and exerts an inhibitory effect on adenosine signaling.

Contribution of Nrf2 to Atherogenic Phenotype Switching of Coronary Arterial Smooth Muscle Cells Lacking CD38 Gene

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Ming Xu

2015-08-01

Full Text Available Background/Aims: Recent studies have indicated that CD38 gene deficiency results in dedifferentiation or transdifferentiation of arterial smooth muscle cells upon atherogenic stimulations. However, the molecular mechanisms mediating this vascular smooth muscle (SMC phenotypic switching remain unknown. Methods & Results: In the present study, we first characterized the phenotypic change in the primary cultures of coronary arterial myocytes (CAMs from CD38-/- mice. It was shown that CD38 deficiency decreased the expression of contractile marker calponin, SM22α and α-SMA but increased the expression of SMC dedifferentiation marker, vimentin, which was accompanied by enhanced cell proliferation. This phenotypic change in CD38-/- CAMs was enhanced by 7-ketocholesterol (7-Ket, an atherogenic stimulus. We further found that the CD38 deficiency decreased the expression and activity of nuclear factor E2-related factor 2 (Nrf2, a basic leucine zipper (bZIP transcription factor sensitive to redox regulation. Similar to CD38 deletion, Nrf2 gene silencing increased CAM dedifferentiation upon 7-Ket stimulation. In contrast, the overexpression of Nrf2 gene abolished 7-Ket-induced dedifferentiation in CD38-/- CAMs. Given the sensitivity of Nrf2 to oxidative stress, we determined the role of redox signaling in the regulation of Nrf2 expression and activity associated with CD38 effect in CAM phenotype changes. It was demonstrated that in CD38-/- CAMs, 7-Ket failed to stimulate the production of O2-., while in CD38+/+ CAMs 7-Ket induced marked O2-. production and enhancement of Nrf2 activity, which was substantially attenuated by NOX4 gene silencing. Finally, we demonstrated that 7-Ket-induced and NOX4-dependent O2-. production was inhibited by 8-Br-cADPR, an antagonist of cADPR or NED-19, an antagonist of NAADP as product of CD38 ADP-ribosylcyclase, which significantly inhibited the level of cytosolic Ca2+ and the activation of Nrf2 under 7-Ket. Conclusion

New insights into redox regulation of stem cell self-renewal and differentiation.

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Ren, Fenglian; Wang, Kui; Zhang, Tao; Jiang, Jingwen; Nice, Edouard Collins; Huang, Canhua

2015-08-01

Reactive oxygen species (ROS), the natural byproducts of aerobic metabolism, are precisely orchestrated to evoke diverse signaling pathways. To date, studies have focused mainly on the detrimental effects of ROS in stem cells. Recently, accumulating evidence has suggested that ROS also function as second messengers that modulate stem cell self-renewal and differentiation by regulating intricate signaling networks. Although many efforts have been made to clarify the general effects of ROS on signal transduction in stem cells, less is known about the initial and direct executors of ROS signaling, which are known as 'redox sensors'. Modifications of cysteine residues in redox sensors are of significant importance in the modulation of protein function in response to different redox conditions. Intriguingly, most key molecules in ROS signaling and cell cycle regulation (including transcriptional factors and kinases) that are crucial in the regulation of stem cell self-renewal and differentiation have the potential to be redox sensors. We highlight herein the importance of redox regulation of these key regulators in stem cell self-renewal and differentiation. Understanding the mechanisms of redox regulation in stem cell self-renewal and differentiation will open exciting new perspectives for stem cell biology. This article is part of a Special Issue entitled Redox regulation of differentiation and de-differentiation. Copyright © 2015 Elsevier B.V. All rights reserved.

Gene Modification of Mesenchymal Stem Cells and Articular Chondrocytes to Enhance Chondrogenesis

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Saliya Gurusinghe

2014-01-01

Full Text Available Current cell based treatment for articular cartilage and osteochondral defects are hampered by issues such as cellular dedifferentiation and hypertrophy of the resident or transplanted cells. The reduced expression of chondrogenic signalling molecules and transcription factors is a major contributing factor to changes in cell phenotype. Gene modification of chondrocytes may be one approach to redirect cells to their primary phenotype and recent advances in nonviral and viral gene delivery technologies have enabled the expression of these lost factors at high efficiency and specificity to regain chondrocyte function. This review focuses on the various candidate genes that encode signalling molecules and transcription factors that are specific for the enhancement of the chondrogenic phenotype and also how epigenetic regulators of chondrogenesis in the form of microRNA may also play an important role.

Contribution of Schwann Cells to Remyelination in a Naturally Occurring Canine Model of CNS Neuroinflammation.

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Kristel Kegler

Full Text Available Gliogenesis under pathophysiological conditions is of particular clinical relevance since it may provide evidence for regeneration promoting cells recruitable for therapeutic purposes. There is evidence that neurotrophin receptor p75 (p75NTR-expressing cells emerge in the lesioned CNS. However, the phenotype and identity of these cells, and signals triggering their in situ generation under normal conditions and certain pathological situations has remained enigmatic. In the present study, we used a spontaneous, idiopathic and inflammatory CNS condition in dogs with prominent lympho-histiocytic infiltration as a model to study the phenotype of Schwann cells and their relation to Schwann cell remyelination within the CNS. Furthermore, the phenotype of p75NTR-expressing cells within the injured CNS was compared to their counter-part in control sciatic nerve and after peripheral nerve injury. In addition, organotypic slice cultures were used to further elucidate the origin of p75NTR-positive cells. In cerebral and cerebellar white and grey matter lesions as well as in the brain stem, p75NTR-positive cells co-expressed the transcription factor Sox2, but not GAP-43, GFAP, Egr2/Krox20, periaxin and PDGFR-α. Interestingly, and contrary to the findings in control sciatic nerves, p75NTR-expressing cells only co-localized with Sox2 in degenerative neuropathy, thus suggesting that such cells might represent dedifferentiated Schwann cells both in the injured CNS and PNS. Moreover, effective Schwann cell remyelination represented by periaxin- and P0-positive mature myelinating Schwann cells, was strikingly associated with the presence of p75NTR/Sox2-expressing Schwann cells. Intriguingly, the emergence of dedifferentiated Schwann cells was not affected by astrocytes, and a macrophage-dominated inflammatory response provided an adequate environment for Schwann cells plasticity within the injured CNS. Furthermore, axonal damage was reduced in brain stem areas

TGF-β-stimulated aberrant expression of class III β-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

International Nuclear Information System (INIS)

Chung, Eun Jee; Chun, Ji Na; Jung, Sun-Ah; Cho, Jin Won; Lee, Joon H.

2011-01-01

Highlights: ► TGF-β induces aberrant expression of βIII in RPE cells via the ERK pathway. ► TGF-β increases O-GlcNAc modification of βIII in RPE cells. ► Mature RPE cells have the capacity to express a neuron-associated gene by TGF-β. -- Abstract: The class III β-tubulin isotype (β III ) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III β-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-β (TGF-β) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-β on the aberrant expression of class III β-tubulin and the intracellular signaling pathway mediating these changes. TGF-β-induced aberrant expression and O-linked-β-N-acetylglucosamine (O-GlcNac) modification of class III β-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-β also stimulated phosphorylation of ERK. TGF-β-induced aberrant expression of class III β-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-β stimulated aberrant expression of class III β-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-β stimulation and provide useful information towards understanding the pathogenesis of proliferative vitreoretinal diseases.

TGF-{beta}-stimulated aberrant expression of class III {beta}-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

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Chung, Eun Jee [Department of Ophthalmology, National Health Insurance Corporation Ilsan Hospital, Gyeonggi-do (Korea, Republic of); Chun, Ji Na; Jung, Sun-Ah [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of); Cho, Jin Won [Department of Biology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Lee, Joon H., E-mail: joonhlee@konyang.ac.kr [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of)

2011-11-18

Highlights: Black-Right-Pointing-Pointer TGF-{beta} induces aberrant expression of {beta}III in RPE cells via the ERK pathway. Black-Right-Pointing-Pointer TGF-{beta} increases O-GlcNAc modification of {beta}III in RPE cells. Black-Right-Pointing-Pointer Mature RPE cells have the capacity to express a neuron-associated gene by TGF-{beta}. -- Abstract: The class III {beta}-tubulin isotype ({beta}{sub III}) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III {beta}-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-{beta} (TGF-{beta}) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-{beta} on the aberrant expression of class III {beta}-tubulin and the intracellular signaling pathway mediating these changes. TGF-{beta}-induced aberrant expression and O-linked-{beta}-N-acetylglucosamine (O-GlcNac) modification of class III {beta}-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-{beta} also stimulated phosphorylation of ERK. TGF-{beta}-induced aberrant expression of class III {beta}-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-{beta} stimulated aberrant expression of class III {beta}-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-{beta} stimulation and provide useful information

Redifferentiation of insulin-secreting cells after in vitro expansion of adult human pancreatic islet tissue

International Nuclear Information System (INIS)

Lechner, Andreas; Nolan, Anna L.; Blacken, Robyn A.; Habener, Joel F.

2005-01-01

Cellular replacement therapy holds promise for the treatment of diabetes mellitus but donor tissue is severely limited. Therefore, we investigated whether insulin-secreting cells could be differentiated in vitro from a monolayer of cells expanded from human donor pancreatic islets. We describe a three-step culture protocol that allows for the efficient generation of insulin-producing cell clusters from in vitro expanded, hormone-negative cells. These clusters express insulin at levels of up to 34% that of average freshly isolated human islets and secrete C-peptide upon membrane depolarization. They also contain cells expressing the other major islet hormones (glucagon, somatostatin, and pancreatic polypeptide). The source of the newly differentiated endocrine cells could either be indigenous stem/progenitor cells or the proliferation-associated dedifferentiation and subsequent redifferentiation of mature endocrine cells. The in vitro generated cell clusters may be efficacious in providing islet-like tissue for transplantation into diabetic recipients

Asymptomatic dedifferentiated liposarcoma mimicking renal cell ...

African Journals Online (AJOL)

M. El Howairis

2016-11-23

Nov 23, 2016 ... Production and hosting by Elsevier B.V. This is an open ... bilateral cataracts which had been previously treated successfully. ... multidisciplinary approach is paramount to treat the patient effec- tively ... Portsite recurrence after laparoscopy for stag- ... population-based analysis of epidemiology, surgery, and ...

Neurotrophic regulation of epidermal dedifferentiation during wound healing and limb regeneration in the axolotl (Ambystoma mexicanum).

Science.gov (United States)

Satoh, A; Graham, G M C; Bryant, S V; Gardiner, D M

2008-07-15

Adult urodeles (salamanders) are unique in their ability to regenerate complex organs perfectly. The recently developed Accessory Limb Model (ALM) in the axolotl provides an opportunity to identify and characterize the essential signaling events that control the early steps in limb regeneration. The ALM demonstrates that limb regeneration progresses in a stepwise fashion that is dependent on signals from the wound epidermis, nerves and dermal fibroblasts from opposite sides of the limb. When all the signals are present, a limb is formed de novo. The ALM thus provides an opportunity to identify and characterize the signaling pathways that control blastema morphogenesis and limb regeneration. In the present study, we have utilized the ALM to identity the buttonhead-like zinc-finger transcription factor, Sp9, as being involved in the formation of the regeneration epithelium. Sp9 expression is induced in basal keratinocytes of the apical blastema epithelium in a pattern that is comparable to its expression in developing limb buds, and it thus is an important marker for dedifferentiation of the epidermis. Induction of Sp9 expression is nerve-dependent, and we have identified KGF as an endogenous nerve factor that induces expression of Sp9 in the regeneration epithelium.

Neuropilin-2 induced by transforming growth factor-β augments migration of hepatocellular carcinoma cells

International Nuclear Information System (INIS)

Wittmann, Philipp; Grubinger, Markus; Gröger, Christian; Huber, Heidemarie; Sieghart, Wolfgang; Peck-Radosavljevic, Markus; Mikulits, Wolfgang

2015-01-01

Hepatocellular carcinoma (HCC) is the most common form of liver cancer and the third most lethal cancer worldwide. The epithelial to mesenchymal transition (EMT) describes the transformation of well-differentiated epithelial cells to a de-differentiated phenotype and plays a central role in the invasion and intrahepatic metastasis of HCC cells. Modulation of the transforming growth factor-β (TGF-β) signaling is known to induce various tumor-promoting and EMT-inducing pathways in HCC. The meta-analysis of a panel of EMT gene expression studies revealed that neuropilin 2 (NRP2) is significantly upregulated in cells that have undergone EMT induced by TGF-β. In this study we assessed the functional role of NRP2 in epithelial and mesenchymal-like HCC cells and focused on the molecular interplay between NRP2 and TGF-β/Smad signaling. NRP2 expression was analyzed in human HCC cell lines and tissue arrays comprising 133 HCC samples. Cell migration was examined by wound healing and Transwell assays in the presence and absence of siRNA against NRP2. NRP2 and TGF-β signaling were analyzed by Western blotting and confocal immunofluorescence microscopy. We show that NRP2 is particularly expressed in HCC cell lines with a dedifferentiated, mesenchymal-like phenotype. NRP2 expression is upregulated by the canonical TGF-β/Smad signaling while NRP2 expression has no impact on TGF-β signaling in HCC cells. Reduced expression of NRP2 by knock-down or inhibition of TGF-β signaling resulted in diminished cell migration independently of each other, suggesting that NRP2 fails to collaborate with TGF-β signaling in cell movement. In accordance with these data, elevated levels of NRP2 correlated with a higher tumor grade and less differentiation in a large collection of human HCC specimens. These data suggest that NRP2 associates with a less differentiated, mesenchymal-like HCC phenotype and that NRP2 plays an important role in tumor cell migration upon TGF-β-dependent HCC

Aberrant innate immune activation following tissue injury impairs pancreatic regeneration.

Directory of Open Access Journals (Sweden)

Alexandra E Folias

Full Text Available Normal tissue architecture is disrupted following injury, as resident tissue cells become damaged and immune cells are recruited to the site of injury. While injury and inflammation are critical to tissue remodeling, the inability to resolve this response can lead to the destructive complications of chronic inflammation. In the pancreas, acinar cells of the exocrine compartment respond to injury by transiently adopting characteristics of progenitor cells present during embryonic development. This process of de-differentiation creates a window where a mature and stable cell gains flexibility and is potentially permissive to changes in cellular fate. How de-differentiation can turn an acinar cell into another cell type (such as a pancreatic β-cell, or a cell with cancerous potential (as in cases of deregulated Kras activity is of interest to both the regenerative medicine and cancer communities. While it is known that inflammation and acinar de-differentiation increase following pancreatic injury, it remains unclear which immune cells are involved in this process. We used a combination of genetically modified mice, immunological blockade and cellular characterization to identify the immune cells that impact pancreatic regeneration in an in vivo model of pancreatitis. We identified the innate inflammatory response of macrophages and neutrophils as regulators of pancreatic regeneration. Under normal conditions, mild innate inflammation prompts a transient de-differentiation of acinar cells that readily dissipates to allow normal regeneration. However, non-resolving inflammation developed when elevated pancreatic levels of neutrophils producing interferon-γ increased iNOS levels and the pro-inflammatory response of macrophages. Pancreatic injury improved following in vivo macrophage depletion, iNOS inhibition as well as suppression of iNOS levels in macrophages via interferon-γ blockade, supporting the impairment in regeneration and the

A combined approach for the assessment of cell viability and cell functionality of human fibrochondrocytes for use in tissue engineering.

Science.gov (United States)

Garzón, Ingrid; Carriel, Victor; Marín-Fernández, Ana Belén; Oliveira, Ana Celeste; Garrido-Gómez, Juan; Campos, Antonio; Sánchez-Quevedo, María Del Carmen; Alaminos, Miguel

2012-01-01

Temporo-mandibular joint disc disorders are highly prevalent in adult populations. Autologous chondrocyte implantation is a well-established method for the treatment of several chondral defects. However, very few studies have been carried out using human fibrous chondrocytes from the temporo-mandibular joint (TMJ). One of the main drawbacks associated to chondrocyte cell culture is the possibility that chondrocyte cells kept in culture tend to de-differentiate and to lose cell viability under in in-vitro conditions. In this work, we have isolated human temporo-mandibular joint fibrochondrocytes (TMJF) from human disc and we have used a highly-sensitive technique to determine cell viability, cell proliferation and gene expression of nine consecutive cell passages to determine the most appropriate cell passage for use in tissue engineering and future clinical use. Our results revealed that the most potentially viable and functional cell passages were P5-P6, in which an adequate equilibrium between cell viability and the capability to synthesize all major extracellular matrix components exists. The combined action of pro-apoptotic (TRAF5, PHLDA1) and anti-apoptotic genes (SON, HTT, FAIM2) may explain the differential cell viability levels that we found in this study. These results suggest that TMJF should be used at P5-P6 for cell therapy protocols.

Fabrication of contacts for silicon solar cells including printing burn through layers

Science.gov (United States)

Ginley, David S; Kaydanova, Tatiana; Miedaner, Alexander; Curtis, Calvin J; Van Hest, Marinus Franciscus Antonius Maria

2014-06-24

A method for fabricating a contact (240) for a solar cell (200). The method includes providing a solar cell substrate (210) with a surface that is covered or includes an antireflective coating (220). For example, the substrate (210) may be positioned adjacent or proximate to an outlet of an inkjet printer (712) or other deposition device. The method continues with forming a burn through layer (230) on the coating (220) by depositing a metal oxide precursor (e.g., using an inkjet or other non-contact printing method to print or apply a volume of liquid or solution containing the precursor). The method includes forming a contact layer (240) comprising silver over or on the burn through layer (230), and then annealing is performed to electrically connect the contact layer (240) to the surface of the solar cell substrate (210) through a portion of the burn through layer (230) and the coating (220).

Biological alterations of rat podocytes cultured under basolateral hydrostatic pressure

NARCIS (Netherlands)

Coers, W.; Vos, J. T.; Huitema, S.; Dijk, F.; Weening, J. J.

1996-01-01

In vivo, glomerular visceral epithelial cells (GVEC), or podocytes, are morphologically highly differentiated cells which are in close contact with adjacent cells by complex interdigitating foot processes. In vitro, the dedifferentiated appearance of podocytes hampers investigations on podocyte

The CD44(high tumorigenic subsets in lung cancer biospecimens are enriched for low miR-34a expression.

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Saroj K Basak

Full Text Available Cellular heterogeneity is an integral part of cancer development and progression. Progression can be associated with emergence of cells that exhibit high phenotypic plasticity (including "de-differentiation" to primitive developmental states, and aggressive behavioral properties (including high tumorigenic potentials. We observed that many biomarkers that are used to identify Cancer Stem Cells (CSC can label cell subsets in an advanced clinical stage of lung cancer (malignant pleural effusions, or MPE. Thus, CSC-biomarkers may be useful for live sorting functionally distinct cell subsets from individual tumors, which may enable investigators to hone in on the molecular basis for functional heterogeneity. We demonstrate that the CD44(hi (CD44-high cancer cell subsets display higher clonal, colony forming potential than CD44(lo cells (n=3 and are also tumorigenic (n=2/2 when transplanted in mouse xenograft model. The CD44(hi subsets express different levels of embryonal (de-differentiation markers or chromatin regulators. In archived lung cancer tissues, ALDH markers co-localize more with CD44 in squamous cell carcinoma (n=5/7 than Adeno Carcinoma (n=1/12. MPE cancer cells and a lung cancer cell line (NCI-H-2122 exhibit chromosomal abnormalities and 1p36 deletion (n=3/3. Since miR-34a maps to the 1p36 deletion site, low miR-34a expression levels were detected in these cells. The colony forming efficiency of CD44(hi cells, characteristic property of CSC, can be inhibited by mir-34a replacement in these samples. In addition the highly tumorigenic CD44(hi cells are enriched for cells in the G2 phase of cell cycle.

Ten years since the discovery of iPS cells: The current state of their clinical application.

Science.gov (United States)

Aznar, J; Tudela, J

On the 10-year anniversary of the discovery of induced pluripotent stem cells, we review the main results from their various fields of application, the obstacles encountered during experimentation and the potential applications in clinical practice. The efficacy of induced pluripotent cells in clinical experimentation can be equated to that of human embryonic stem cells; however, unlike stem cells, induced pluripotent cells do not involve the severe ethical difficulties entailed by the need to destroy human embryos to obtain them. The finding of these cells, which was in its day a true scientific milestone worthy of a Nobel Prize in Medicine, is currently enveloped by light and shadow: high hopes for regenerative medicine versus the, as of yet, poorly controlled risks of unpredictable reactions, both in the processes of dedifferentiation and subsequent differentiation to the cell strains employed for therapeutic or experimentation goals. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Langerhans cell sarcoma following marginal zone lymphoma: expanding the knowledge on mature B cell plasticity.

Science.gov (United States)

Ambrosio, Maria Raffaella; De Falco, Giulia; Rocca, Bruno Jim; Barone, Aurora; Amato, Teresa; Bellan, Cristiana; Lazzi, Stefano; Leoncini, Lorenzo

2015-10-01

The concept of unidirectional differentiation of the haematopoietic stem cell has been challenged after recent findings that human B cell progenitors and even mature B cells can be reprogrammed into histiocytic/dendritic cells by altering expression of lineage-associated transcription factors. The conversion of mature B cell lymphomas to Langerhans cell neoplasms is not well documented. Three previous reports have described clonally related follicular lymphoma and Langerhans cell tumours, whereas no case has been published of clonally related marginal zone lymphoma and Langerhans cell sarcoma. We describe the case of a 77-year-old patient who developed a Langerhans cell sarcoma and 6 years later a nodal marginal zone lymphoma. Mutation status examination showed 100 % gene identity to the germline sequence, suggesting direct trans-differentiation or dedifferentiation of the nodal marginal zone lymphoma to the Langerhans cell sarcoma rather than a common progenitor. We found inactivation of paired box 5 (PAX-5) in the lymphoma cells by methylation, along with duplication of part of the long arm of chromosomes 16 and 17 in the sarcoma cells. The absence of PAX-5 could have triggered B cells to differentiate into macrophages and dendritic cells. On the other hand, chromosomal imbalances might have activated genes involved in myeloid lineage maturation, transcription activation and oncogenesis. We hypothesize that this occurred because of previous therapies for nodal marginal zone lymphoma. Better understanding of this phenomenon may help in unravelling the molecular interplay between transcription factors during haematopoietic lineage commitment and may expand the spectrum of clonally related mature B cell neoplasms and Langerhans cell tumours.

Cell migration during heart regeneration in zebrafish.

Science.gov (United States)

Tahara, Naoyuki; Brush, Michael; Kawakami, Yasuhiko

2016-07-01

Zebrafish possess the remarkable ability to regenerate injured hearts as adults, which contrasts the very limited ability in mammals. Although very limited, mammalian hearts do in fact have measurable levels of cardiomyocyte regeneration. Therefore, elucidating mechanisms of zebrafish heart regeneration would provide information of naturally occurring regeneration to potentially apply to mammalian studies, in addition to addressing this biologically interesting phenomenon in itself. Studies over the past 13 years have identified processes and mechanisms of heart regeneration in zebrafish. After heart injury, pre-existing cardiomyocytes dedifferentiate, enter the cell cycle, and repair the injured myocardium. This process requires interaction with epicardial cells, endocardial cells, and vascular endothelial cells. Epicardial cells envelope the heart, while endocardial cells make up the inner lining of the heart. They provide paracrine signals to cardiomyocytes to regenerate the injured myocardium, which is vascularized during heart regeneration. In addition, accumulating results suggest that local migration of these major cardiac cell types have roles in heart regeneration. In this review, we summarize the characteristics of various heart injury methods used in the research community and regeneration of the major cardiac cell types. Then, we discuss local migration of these cardiac cell types and immune cells during heart regeneration. Developmental Dynamics 245:774-787, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

In vitro differentiation of HT-29 M6 mucus-secreting colon cancer cells involves a trychostatin A and p27(KIP1)-inducible transcriptional program of gene expression.

Science.gov (United States)

Mayo, Clara; Lloreta, Josep; Real, Francisco X; Mayol, Xavier

2007-07-01

Tumor cell dedifferentiation-such as the loss of cell-to-cell adhesion in epithelial tumors-is associated with tumor progression. To better understand the mechanisms that maintain carcinoma cells in a differentiated state, we have dissected in vitro differentiation pathways in the mucus-secretor HT-29 M6 colon cancer cell line, which spontaneously differentiates in postconfluent cultures. By lowering the extracellular calcium concentration to levels that prevent intercellular adhesion and epithelial polarization, our results reveal that differentiation is calcium-dependent and involves: (i) a process of cell cycle exit to G(0) and (ii) the induction of a transcriptional program of differentiation gene expression (i.e., mucins MUC1 and MUC5AC, and the apical membrane peptidase DPPIV). In calcium-deprived, non-differentiated postconfluent cultures, differentiation gene promoters are repressed by a trichostatin A (TSA)-sensitive mechanism, indicating that loss of gene expression by dedifferentiation is driven by histone deacetylases (HDAC). Since TSA treatment or extracellular calcium restoration allow gene promoter activation to similar levels, we suggest that induction of differentiation is one mechanism of HDAC inhibitor antitumor action. Moreover, transcriptional de-repression can also be induced in non-differentiating culture conditions by overexpressing the cyclin-dependent kinase inhibitor p27(KIP1), which is normally induced during spontaneous differentiation. Since p27(KIP1) downregulation in colon cancer is associated with poor prognosis independently of tumor cell division rates, we propose that p27 (KIP1) may prevent tumor progression by, at least in part, enhancing the expression of some differentiation genes. Therefore, the HT-29 M6 model allows the identification of some basic mechanisms of cancer cell differentiation control, so far revealing HDAC and p27(KIP1) as key regulatory factors of differentiation gene expression.

Smooth muscle-like tissue constructs with circumferentially oriented cells formed by the cell fiber technology.

Science.gov (United States)

Hsiao, Amy Y; Okitsu, Teru; Onoe, Hiroaki; Kiyosawa, Mahiro; Teramae, Hiroki; Iwanaga, Shintaroh; Kazama, Tomohiko; Matsumoto, Taro; Takeuchi, Shoji

2015-01-01

The proper functioning of many organs and tissues containing smooth muscles greatly depends on the intricate organization of the smooth muscle cells oriented in appropriate directions. Consequently controlling the cellular orientation in three-dimensional (3D) cellular constructs is an important issue in engineering tissues of smooth muscles. However, the ability to precisely control the cellular orientation at the microscale cannot be achieved by various commonly used 3D tissue engineering building blocks such as spheroids. This paper presents the formation of coiled spring-shaped 3D cellular constructs containing circumferentially oriented smooth muscle-like cells differentiated from dedifferentiated fat (DFAT) cells. By using the cell fiber technology, DFAT cells suspended in a mixture of extracellular proteins possessing an optimized stiffness were encapsulated in the core region of alginate shell microfibers and uniformly aligned to the longitudinal direction. Upon differentiation induction to the smooth muscle lineage, DFAT cell fibers self-assembled to coiled spring structures where the cells became circumferentially oriented. By changing the initial core-shell microfiber diameter, we demonstrated that the spring pitch and diameter could be controlled. 21 days after differentiation induction, the cell fibers contained high percentages of ASMA-positive and calponin-positive cells. Our technology to create these smooth muscle-like spring constructs enabled precise control of cellular alignment and orientation in 3D. These constructs can further serve as tissue engineering building blocks for larger organs and cellular implants used in clinical treatments.

A myogenic precursor cell that could contribute to regeneration in zebrafish and its similarity to the satellite cell.

Science.gov (United States)

Siegel, Ashley L; Gurevich, David B; Currie, Peter D

2013-09-01

The cellular basis for mammalian muscle regeneration has been an area of intense investigation over recent decades. The consensus is that a specialized self-renewing stem cell, termed the satellite cell, plays a major role during the process of regeneration in amniotes. How broadly this mechanism is deployed within the vertebrate phylogeny remains an open question. A lack of information on the role of cells analogous to the satellite cell in other vertebrate systems is even more unexpected given the fact that satellite cells were first designated in frogs. An intriguing aspect of this debate is that a number of amphibia and many fish species exhibit epimorphic regenerative processes in specific tissues, whereby regeneration occurs by the dedifferentiation of the damaged tissue, without deploying specialized stem cell populations analogous to satellite cells. Hence, it is feasible that a cellular process completely distinct from that deployed during mammalian muscle regeneration could operate in species capable of epimorphic regeneration. In this minireview, we examine the evidence for the broad phylogenetic distribution of satellite cells. We conclude that, in the vertebrates examined so far, epimorphosis does not appear to be deployed during muscle regeneration, and that analogous cells expressing similar marker genes to satellite cells appear to be deployed during the regenerative process. However, the functional definition of these cells as self-renewing muscle stem cells remains a final hurdle to the definition of the satellite cell as a generic vertebrate cell type. © 2013 FEBS.

A combined approach for the assessment of cell viability and cell functionality of human fibrochondrocytes for use in tissue engineering.

Directory of Open Access Journals (Sweden)

Ingrid Garzón

Full Text Available Temporo-mandibular joint disc disorders are highly prevalent in adult populations. Autologous chondrocyte implantation is a well-established method for the treatment of several chondral defects. However, very few studies have been carried out using human fibrous chondrocytes from the temporo-mandibular joint (TMJ. One of the main drawbacks associated to chondrocyte cell culture is the possibility that chondrocyte cells kept in culture tend to de-differentiate and to lose cell viability under in in-vitro conditions. In this work, we have isolated human temporo-mandibular joint fibrochondrocytes (TMJF from human disc and we have used a highly-sensitive technique to determine cell viability, cell proliferation and gene expression of nine consecutive cell passages to determine the most appropriate cell passage for use in tissue engineering and future clinical use. Our results revealed that the most potentially viable and functional cell passages were P5-P6, in which an adequate equilibrium between cell viability and the capability to synthesize all major extracellular matrix components exists. The combined action of pro-apoptotic (TRAF5, PHLDA1 and anti-apoptotic genes (SON, HTT, FAIM2 may explain the differential cell viability levels that we found in this study. These results suggest that TMJF should be used at P5-P6 for cell therapy protocols.

Human induced pluripotent cells resemble embryonic stem cells demonstrating enhanced levels of DNA repair and efficacy of nonhomologous end-joining

Energy Technology Data Exchange (ETDEWEB)

Fan Jinshui; Robert, Carine [Department of Radiation Oncology, University of Maryland School of Medicine, 655 West Baltimore Street, BRB 7-023A, Baltimore, MD 21201 (United States); Jang, Yoon-Young; Liu Hua; Sharkis, Saul; Baylin, Stephen Bruce [Johns Hopkins University School of Medicine, Department of Oncology, Baltimore, MD 21231-1000 (United States); Rassool, Feyruz Virgilia, E-mail: frassool@som.umaryland.edu [Department of Radiation Oncology, University of Maryland School of Medicine, 655 West Baltimore Street, BRB 7-023A, Baltimore, MD 21201 (United States)

2011-08-01

Highlights: {yields} iPSC and hESC demonstrate a similar cell cycle profile, with increased S phase cells and decreased G0/G1. {yields} iPSC and hESC increased ROS and decreased DSBs, compared with differentiated parental cells. {yields} iPSC and hESC demonstrate elevated DSB repair activity, including nonhomologous end-joining, compared with differentiated parental cells. {yields} iPSC however show a partial apoptotic response to DNA damage, compared to hESC. {yields} DNA damage responses may constitute important markers for the efficacy of iPSC reprogramming. - Abstract: To maintain the integrity of the organism, embryonic stem cells (ESC) need to maintain their genomic integrity in response to DNA damage. DNA double strand breaks (DSBs) are one of the most lethal forms of DNA damage and can have disastrous consequences if not repaired correctly, leading to cell death, genomic instability and cancer. How human ESC (hESC) maintain genomic integrity in response to agents that cause DSBs is relatively unclear. Adult somatic cells can be induced to 'dedifferentiate' into induced pluripotent stem cells (iPSC) and reprogram into cells of all three germ layers. Whether iPSC have reprogrammed the DNA damage response is a critical question in regenerative medicine. Here, we show that hESC demonstrate high levels of endogenous reactive oxygen species (ROS) which can contribute to DNA damage and may arise from high levels of metabolic activity. To potentially counter genomic instability caused by DNA damage, we find that hESC employ two strategies: First, these cells have enhanced levels of DNA repair proteins, including those involved in repair of DSBs, and they demonstrate elevated nonhomologous end-joining (NHEJ) activity and repair efficacy, one of the main pathways for repairing DSBs. Second, they are hypersensitive to DNA damaging agents, as evidenced by a high level of apoptosis upon irradiation. Importantly, iPSC, unlike the parent cells they are derived

Human induced pluripotent cells resemble embryonic stem cells demonstrating enhanced levels of DNA repair and efficacy of nonhomologous end-joining

International Nuclear Information System (INIS)

Fan Jinshui; Robert, Carine; Jang, Yoon-Young; Liu Hua; Sharkis, Saul; Baylin, Stephen Bruce; Rassool, Feyruz Virgilia

2011-01-01

Highlights: → iPSC and hESC demonstrate a similar cell cycle profile, with increased S phase cells and decreased G0/G1. → iPSC and hESC increased ROS and decreased DSBs, compared with differentiated parental cells. → iPSC and hESC demonstrate elevated DSB repair activity, including nonhomologous end-joining, compared with differentiated parental cells. → iPSC however show a partial apoptotic response to DNA damage, compared to hESC. → DNA damage responses may constitute important markers for the efficacy of iPSC reprogramming. - Abstract: To maintain the integrity of the organism, embryonic stem cells (ESC) need to maintain their genomic integrity in response to DNA damage. DNA double strand breaks (DSBs) are one of the most lethal forms of DNA damage and can have disastrous consequences if not repaired correctly, leading to cell death, genomic instability and cancer. How human ESC (hESC) maintain genomic integrity in response to agents that cause DSBs is relatively unclear. Adult somatic cells can be induced to 'dedifferentiate' into induced pluripotent stem cells (iPSC) and reprogram into cells of all three germ layers. Whether iPSC have reprogrammed the DNA damage response is a critical question in regenerative medicine. Here, we show that hESC demonstrate high levels of endogenous reactive oxygen species (ROS) which can contribute to DNA damage and may arise from high levels of metabolic activity. To potentially counter genomic instability caused by DNA damage, we find that hESC employ two strategies: First, these cells have enhanced levels of DNA repair proteins, including those involved in repair of DSBs, and they demonstrate elevated nonhomologous end-joining (NHEJ) activity and repair efficacy, one of the main pathways for repairing DSBs. Second, they are hypersensitive to DNA damaging agents, as evidenced by a high level of apoptosis upon irradiation. Importantly, iPSC, unlike the parent cells they are derived from, mimic hESC in their ROS levels

Cell Phenotype Transitions in Cardiovascular Calcification

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Luis Hortells

2018-03-01

Full Text Available Cardiovascular calcification was originally considered a passive, degenerative process, however with the advance of cellular and molecular biology techniques it is now appreciated that ectopic calcification is an active biological process. Vascular calcification is the most common form of ectopic calcification, and aging as well as specific disease states such as atherosclerosis, diabetes, and genetic mutations, exhibit this pathology. In the vessels and valves, endothelial cells, smooth muscle cells, and fibroblast-like cells contribute to the formation of extracellular calcified nodules. Research suggests that these vascular cells undergo a phenotypic switch whereby they acquire osteoblast-like characteristics, however the mechanisms driving the early aspects of these cell transitions are not fully understood. Osteoblasts are true bone-forming cells and differentiate from their pluripotent precursor, the mesenchymal stem cell (MSC; vascular cells that acquire the ability to calcify share aspects of the transcriptional programs exhibited by MSCs differentiating into osteoblasts. What is unknown is whether a fully-differentiated vascular cell directly acquires the ability to calcify by the upregulation of osteogenic genes or, whether these vascular cells first de-differentiate into an MSC-like state before obtaining a “second hit” that induces them to re-differentiate down an osteogenic lineage. Addressing these questions will enable progress in preventative and regenerative medicine strategies to combat vascular calcification pathologies. In this review, we will summarize what is known about the phenotypic switching of vascular endothelial, smooth muscle, and valvular cells.

Fluorescence In Situ Hybridization for MDM2 Amplification as a Routine Ancillary Diagnostic Tool for Suspected Well-Differentiated and Dedifferentiated Liposarcomas: Experience at a Tertiary Center

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Khin Thway

2015-01-01

Full Text Available Background. The assessment of MDM2 gene amplification by fluorescence in situ hybridization (FISH has become a routine ancillary tool for diagnosing atypical lipomatous tumor (ALT/well-differentiated liposarcoma and dedifferentiated liposarcoma (WDL/DDL in specialist sarcoma units. We describe our experience of its utility at our tertiary institute. Methods. All routine histology samples in which MDM2 amplification was assessed with FISH over a 2-year period were included, and FISH results were correlated with clinical and histologic findings. Results. 365 samples from 347 patients had FISH for MDM2 gene amplification. 170 were positive (i.e., showed MDM2 gene amplification, 192 were negative, and 3 were technically unsatisfactory. There were 122 histologically benign cases showing a histology:FISH concordance rate of 92.6%, 142 WDL/DDL (concordance 96.5%, and 34 cases histologically equivocal for WDL (concordance 50%. Of 64 spindle cell/pleomorphic neoplasms (in which DDL was a differential diagnosis, 21.9% showed MDM2 amplification. Of the cases with discrepant histology and FISH, all but 3 had diagnoses amended following FISH results. For discrepancies of benign histology but positive FISH, lesions were on average larger, more frequently in “classical” (intra-abdominal or inguinal sites for WDL/DDL and more frequently core biopsies. Discrepancies of malignant histology but negative FISH were smaller, less frequently in “classical” sites but again more frequently core biopsies. Conclusions. FISH has a high correlation rate with histology for cases with firm histologic diagnoses of lipoma or WDL/DDL. It is a useful ancillary diagnostic tool in histologically equivocal cases, particularly in WDL lacking significant histologic atypia or DDL without corresponding WDL component, especially in larger tumors, those from intra-abdominal or inguinal sites or core biopsies. There is a significant group of well-differentiated adipocytic neoplasms

Pre-procambial cells are niches for pluripotent and totipotent stem-like cells for organogenesis and somatic embryogenesis in the peach palm: a histological study.

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de Almeida, Marcilio; de Almeida, Cristina Vieira; Mendes Graner, Erika; Ebling Brondani, Gilvano; Fiori de Abreu-Tarazi, Monita

2012-08-01

The direct induction of adventitious buds and somatic embryos from explants is a morphogenetic process that is under the influence of exogenous plant growth regulators and its interactions with endogenous phytohormones. We performed an in vitro histological analysis in peach palm (Bactris gasipaes Kunth) shoot apexes and determined that the positioning of competent cells and their interaction with neighboring cells, under the influence of combinations of exogenously applied growth regulators (NAA/BAP and NAA/TDZ), allows the pre-procambial cells (PPCs) to act in different morphogenic pathways to establish niche competent cells. It is likely that there has been a habituation phenomenon during the regeneration and development of the microplants. This includes promoting the tillering of primary or secondary buds due to culturing in the absence of NAA/BAP or NAA/TDZ after a period in the presence of these growth regulators. Histological analyses determined that the adventitious roots were derived from the dedifferentiation of the parenchymal cells located in the basal region of the adventitious buds, with the establishment of rooting pole, due to an auxin gradient. Furthermore, histological and histochemical analyses allowed us to characterize how the PPCs provide niches for multipotent, pluripotent and totipotent stem-like cells for vascular differentiation, organogenesis and somatic embryogenesis in the peach palm. The histological and histochemical analyses also allowed us to detect the unicellular or multicellular origin of somatic embryogenesis. Therefore, our results indicate that the use of growth regulators in microplants can lead to habituation and to different morphogenic pathways leading to potential niche establishment, depending on the positioning of the competent cells and their interaction with neighboring cells. Our results indicate that the use of growth regulators in microplants can lead to habituation and to different morphogenic pathways leading to

Mitochondrial metabolism and the control of vascular smooth muscle cell proliferation

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Mario eChiong

2014-12-01

Full Text Available Differentiation and dedifferentiation of vascular smooth muscle cells (VSMCs are essential processes of vascular development. VSMCs have biosynthetic, proliferative and contractile roles in the vessel wall. Alterations in the differentiated state of the VSMCs play a critical role in the pathogenesis of a variety of cardiovascular diseases, including atherosclerosis, hypertension and vascular stenosis. This review provides an overview of the current state of knowledge of molecular mechanisms involved in the control of VSMC proliferation, with particular focus on mitochondrial metabolism. Mitochondrial activity can be controlled by regulating mitochondrial dynamics, i.e. mitochondrial fusion and fission, and by regulating mitochondrial calcium handling through the interaction with the endoplasmic reticulum (ER. Alterations in both VSMC proliferation and mitochondrial function can be triggered by dysregulation of mitofusin-2, a small GTPase associated with mitochondrial fusion and mitochondrial-ER interaction. Several lines of evidence highlight the relevance of mitochondrial metabolism in the control of VSMC proliferation, indicating a new area to be explored in the treatment of vascular diseases.

Differentiation within autologous fibrin scaffolds of porcine dermal cells with the mesenchymal stem cell phenotype

International Nuclear Information System (INIS)

Puente, Pilar de la; Ludeña, Dolores; López, Marta; Ramos, Jennifer; Iglesias, Javier

2013-01-01

Porcine mesenchymal stem cells (pMSCs) are an attractive source of cells for tissue engineering because their properties are similar to those of human stem cells. pMSCs can be found in different tissues but their dermal origin has not been studied in depth. Additionally, MSCs differentiation in monolayer cultures requires subcultured cells, and these cells are at risk of dedifferentiation when implanting them into living tissue. Following this, we attempted to characterize the MSCs phenotype of porcine dermal cells and to evaluate their cellular proliferation and differentiation in autologous fibrin scaffolds (AFSs). Dermal biopsies and blood samples were obtained from 12 pigs. Dermal cells were characterized by flow cytometry. Frozen autologous plasma was used to prepare AFSs. pMSC differentiation was studied in standard structures (monolayers and pellets) and in AFSs. The pMSCs expressed the CD90 and CD29 markers of the mesenchymal lineage. AFSs afforded adipogenic, osteogenic and chondrogenic differentiation. The porcine dermis can be proposed to be a good source of MSCs with adequate proliferative capacity and a suitable expression of markers. The pMSCs also showed optimal proliferation and differentiation in AFSs, such that these might serve as a promising autologous and implantable material for use in tissue engineering. -- Highlights: ► Low fibrinogen concentration provides a suitable matrix for cell migration and differentiation. ► Autologous fibrin scaffolds is a promising technique in tissue engineering. ► Dermal cells are an easily accessible mesenchymal stem cell source. ► Fibrin scaffolds afforded adipogenic, osteogenic and chondrogenic differentiation.

Osteoblast Production by Reserved Progenitor Cells in Zebrafish Bone Regeneration and Maintenance.

Science.gov (United States)

Ando, Kazunori; Shibata, Eri; Hans, Stefan; Brand, Michael; Kawakami, Atsushi

2017-12-04

Mammals cannot re-form heavily damaged bones as in large fracture gaps, whereas zebrafish efficiently regenerate bones even after amputation of appendages. However, the source of osteoblasts that mediate appendage regeneration is controversial. Several studies in zebrafish have shown that osteoblasts are generated by dedifferentiation of existing osteoblasts at injured sites, but other observations suggest that de novo production of osteoblasts also occurs. In this study, we found from cell-lineage tracing and ablation experiments that a group of cells reserved in niches serves as osteoblast progenitor cells (OPCs) and has a significant role in fin ray regeneration. Besides regeneration, OPCs also supply osteoblasts for normal bone maintenance. We further showed that OPCs are derived from embryonic somites, as is the case with embryonic osteoblasts, and are replenished from mesenchymal precursors in adult zebrafish. Our findings reveal that reserved progenitors are a significant and complementary source of osteoblasts for zebrafish bone regeneration. Copyright © 2017 Elsevier Inc. All rights reserved.

Iron

DEFF Research Database (Denmark)

Hansen, Jakob Bondo; Moen, I W; Mandrup-Poulsen, T

2014-01-01

and discuss recent evidence, suggesting that iron is a key pathogenic factor in both type 1 and type 2 diabetes with a focus on inflammatory pathways. Pro-inflammatory cytokine-induced β-cell death is not fully understood, but may include iron-induced ROS formation resulting in dedifferentiation by activation...... of transcription factors, activation of the mitochondrial apoptotic machinery or of other cell death mechanisms. The pro-inflammatory cytokine IL-1β facilitates divalent metal transporter 1 (DMT1)-induced β-cell iron uptake and consequently ROS formation and apoptosis, and we propose that this mechanism provides...

The therapeutic implications of plasticity of the cancer stem cell phenotype.

Directory of Open Access Journals (Sweden)

Kevin Leder

2010-12-01

Full Text Available The cancer stem cell hypothesis suggests that tumors contain a small population of cancer cells that have the ability to undergo symmetric self-renewing cell division. In tumors that follow this model, cancer stem cells produce various kinds of specified precursors that divide a limited number of times before terminally differentiating or undergoing apoptosis. As cells within the tumor mature, they become progressively more restricted in the cell types to which they can give rise. However, in some tumor types, the presence of certain extra- or intracellular signals can induce committed cancer progenitors to revert to a multipotential cancer stem cell state. In this paper, we design a novel mathematical model to investigate the dynamics of tumor progression in such situations, and study the implications of a reversible cancer stem cell phenotype for therapeutic interventions. We find that higher levels of dedifferentiation substantially reduce the effectiveness of therapy directed at cancer stem cells by leading to higher rates of resistance. We conclude that plasticity of the cancer stem cell phenotype is an important determinant of the prognosis of tumors. This model represents the first mathematical investigation of this tumor trait and contributes to a quantitative understanding of cancer.

Modeling of Pem Fuel Cell Systems Including Controls and Reforming Effects for Hybrid Automotive Applications

National Research Council Canada - National Science Library

Boettner, Daisie

2001-01-01

.... This study develops models for a stand-alone Proton Exchange Membrane (PEM) fuel cell stack, a direct-hydrogen fuel cell system including auxiliaries, and a methanol reforming fuel cell system for integration into a vehicle performance simulator...

Org-1-dependent lineage reprogramming generates the ventral longitudinal musculature of the Drosophila heart.

Science.gov (United States)

Schaub, Christoph; März, Johannes; Reim, Ingolf; Frasch, Manfred

2015-02-16

Only few examples of transdifferentiation, which denotes the conversion of one differentiated cell type to another, are known to occur during normal development, and more often, it is associated with regeneration processes. With respect to muscles, dedifferentiation/redifferentiation processes have been documented during post-traumatic muscle regeneration in blastema of newts as well as during myocardial regeneration. As shown herein, the ventral longitudinal muscles of the adult Drosophila heart arise from specific larval alary muscles in a process that represents the first known example of syncytial muscle transdifferentiation via dedifferentiation into mononucleate myoblasts during normal development. We demonstrate that this unique process depends on the reinitiation of a transcriptional program previously employed for embryonic alary muscle development, in which the factors Org-1 (Drosophila Tbx1) and Tailup (Drosophila Islet1) are key components. During metamorphosis, the action of these factors is combined with cell-autonomous inputs from the ecdysone steroid and the Hox gene Ultrabithorax, which provide temporal and spatial specificity to the transdifferentiation events. Following muscle dedifferentiation, inductive cues, particularly from the remodeling heart tube, are required for the redifferentiation of myoblasts into ventral longitudinal muscles. Our results provide new insights into mechanisms of lineage commitment and cell-fate plasticity during development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pancreatic β-cell regeneration: Facultative or dedicated progenitors?

Science.gov (United States)

Afelik, Solomon; Rovira, Meritxell

2017-04-15

The adult pancreas is only capable of limited regeneration. Unlike highly regenerative tissues such as the skin, intestinal crypts and hematopoietic system, no dedicated adult stem cells or stem cell niche have so far been identified within the adult pancreas. New β cells have been shown to form in the adult pancreas, in response to high physiological demand or experimental β-cell ablation, mostly by replication of existing β cells. The possibility that new β cells are formed from other sources is currently a point of major controversy. Under particular injury conditions, fully differentiated pancreatic duct and acinar cells have been shown to dedifferentiate into a progenitor-like state, however the extent, to which ductal, acinar or other endocrine cells contribute to restoring pancreatic β-cell mass remains to be resolved. In this review we focus on regenerative events in the pancreas with emphasis on the restoration of β-cell mass. We present an overview of regenerative responses noted within the different pancreatic lineages, following injury. We also highlight the intrinsic plasticity of the adult pancreas that allows for inter-conversion of fully differentiated pancreatic lineages through manipulation of few genes or growth factors. Taken together, evidence from a number of studies suggest that differentiated pancreatic lineages could act as facultative progenitor cells, but the extent to which these contribute to β-cell regeneration in vivo is still a matter of contention. Copyright © 2016. Published by Elsevier B.V.

Injury-activated glial cells promote wound healing of the adult skin in mice.

Science.gov (United States)

Parfejevs, Vadims; Debbache, Julien; Shakhova, Olga; Schaefer, Simon M; Glausch, Mareen; Wegner, Michael; Suter, Ueli; Riekstina, Una; Werner, Sabine; Sommer, Lukas

2018-01-16

Cutaneous wound healing is a complex process that aims to re-establish the original structure of the skin and its functions. Among other disorders, peripheral neuropathies are known to severely impair wound healing capabilities of the skin, revealing the importance of skin innervation for proper repair. Here, we report that peripheral glia are crucially involved in this process. Using a mouse model of wound healing, combined with in vivo fate mapping, we show that injury activates peripheral glia by promoting de-differentiation, cell-cycle re-entry and dissemination of the cells into the wound bed. Moreover, injury-activated glia upregulate the expression of many secreted factors previously associated with wound healing and promote myofibroblast differentiation by paracrine modulation of TGF-β signalling. Accordingly, depletion of these cells impairs epithelial proliferation and wound closure through contraction, while their expansion promotes myofibroblast formation. Thus, injury-activated glia and/or their secretome might have therapeutic potential in human wound healing disorders.

Development of a Novel Tissue Engineering Strategy Towards Whole Limb Regeneration

National Research Council Canada - National Science Library

Laurencin, Cato T

2008-01-01

.... In contrast to the bottom up approach of limb regeneration that relies on blastema formation outgrowth and cell dedifferentiation as seen in amphibians and lower vertebrates tissue engineering...

Universal cell frame for high-pressure water electrolyzer and electrolyzer including the same

Science.gov (United States)

Schmitt, Edwin W.; Norman, Timothy J.

2013-01-08

Universal cell frame generic for use as an anode frame and as a cathode frame in a water electrolyzer. According to one embodiment, the universal cell frame includes a unitary annular member having a central opening. Four trios of transverse openings are provided in the annular member, each trio being spaced apart by about 90 degrees. A plurality of internal radial passageways fluidly interconnect the central opening and each of the transverse openings of two diametrically-opposed trios of openings, the other two trios of openings lacking corresponding radial passageways. Sealing ribs are provided on the top and bottom surfaces of the annular member. The present invention is also directed at a water electrolyzer that includes two such cell frames, one being used as the anode frame and the other being used as the cathode frame, the cathode frame being rotated 90 degrees relative to the anode frame.

Role of stem cells in large bowel carcinogenesis

Directory of Open Access Journals (Sweden)

N. A. Nefedova

2015-01-01

Full Text Available Сancer stem cells (CSC play a significant role in the development and progression of colorectal cancer. They are capable of self-senewal and multipotent differentiation. CSC can be formed from stem cells or mutant by dedifferentiation of crypt epithelial cells. Recently, much attention is paid to CSC in colon cancer, but very little has been published regarding their expression in colon polyps. In 2010 The World Health Organization attributed the so-called serrated lesions, including hyperplastic polyp, serrated sessile adenoma and traditional serrated adenoma to a group of precancerous lesions of the colon in addition to the classical tubular, villous and tubulo-villous adenomas. Despite the large number of publications devoted to the newly selected category, a full understanding of the processes involved in the formation of polyps and their progression into colon cancer, there is still no. Identification of CSC in colon polyps will assess their potential malignancy conduct adequate therapy, determine the amount of the operation and further treatment strategy. This in turn will contribute to the early detection and prevention of cancer. Identification of CSC, an assessment of their localization and distribution in tubular adenomas, serrated adenoma broad-based, traditional serrated adenoma and hyperplastic polyps allow to evaluate the potential of malignancy and prognosis for each of the polyps. In this regard, the definition of markers characteristic of colon CSC, is interesting not only from a scientific, but also from a practical point of view.

Activation of the Ca2+/calcineurin/NFAT2 pathway controls smooth muscle cell differentiation

International Nuclear Information System (INIS)

Larrieu, Daniel; Thiebaud, Pierre; Duplaa, Cecile; Sibon, Igor; Theze, Nadine; Lamaziere, Jean-Marie Daniel

2005-01-01

Cellular mechanisms controlling smooth muscle cells (SMCs) phenotypic modulation are largely unknown. Intracellular Ca 2+ movements are essential to ensure SMC functions; one of the roles of Ca 2+ is to regulate calcineurin, which in turn induces nuclear localization of the nuclear factor of activated T-cell (NFAT). In order to investigate, during phenotypic differentiation of SMCs, the effect of calcineurin inhibition on NFAT 2 nuclear translocation, we used a culture model of SMC differentiation in serum-free conditions. We show that the treatment of cultured SMC with the calcineurin inhibitor cyclosporine A induced their dedifferentiation while preventing their differentiation. These findings suggest that nuclear translocation of NFAT 2 is dependent of calcineurin activity during the in vitro SMC differentiation kinetic and that the nuclear presence of NFAT 2 is critical in the acquisition and maintenance of SMC differentiation

Solar cells, structures including organometallic halide perovskite monocrystalline films, and methods of preparation thereof

KAUST Repository

Bakr, Osman; Peng, Wei; Wang, Lingfei

2017-01-01

Embodiments of the present disclosure provide for solar cells including an organometallic halide perovskite monocrystalline film (see fig. 1.1B), other devices including the organometallic halide perovskite monocrystalline film, methods of making

Identification of astrocytoma associated genes including cell surface markers

International Nuclear Information System (INIS)

Boon, Kathy; Edwards, Jennifer B; Eberhart, Charles G; Riggins, Gregory J

2004-01-01

Despite intense effort the treatment options for the invasive astrocytic tumors are still limited to surgery and radiation therapy, with chemotherapy showing little or no increase in survival. The generation of Serial Analysis of Gene Expression (SAGE) profiles is expected to aid in the identification of astrocytoma-associated genes and highly expressed cell surface genes as molecular therapeutic targets. SAGE tag counts can be easily added to public expression databases and quickly disseminated to research efforts worldwide. We generated and analyzed the SAGE transcription profiles of 25 primary grade II, III and IV astrocytomas [1]. These profiles were produced as part of the Cancer Genome Anatomy Project's SAGE Genie [2], and were used in an in silico search for candidate therapeutic targets by comparing astrocytoma to normal brain transcription. Real-time PCR and immunohistochemistry were used for the validation of selected candidate target genes in 2 independent sets of primary tumors. A restricted set of tumor-associated genes was identified for each grade that included genes not previously associated with astrocytomas (e.g. VCAM1, SMOC1, and thymidylate synthetase), with a high percentage of cell surface genes. Two genes with available antibodies, Aquaporin 1 and Topoisomerase 2A, showed protein expression consistent with transcript level predictions. This survey of transcription in malignant and normal brain tissues reveals a small subset of human genes that are activated in malignant astrocytomas. In addition to providing insights into pathway biology, we have revealed and quantified expression for a significant portion of cell surface and extra-cellular astrocytoma genes

Photoelectrochemical cell including Ga(Sb.sub.x)N.sub.1-x semiconductor electrode

Science.gov (United States)

Menon, Madhu; Sheetz, Michael; Sunkara, Mahendra Kumar; Pendyala, Chandrashekhar; Sunkara, Swathi; Jasinski, Jacek B.

2017-09-05

The composition of matter comprising Ga(Sb.sub.x)N.sub.1-x where x=0.01 to 0.06 is characterized by a band gap between 2.4 and 1.7 eV. A semiconductor device includes a semiconductor layer of that composition. A photoelectric cell includes that semiconductor device.

The parietal epithelial cell is crucially involved in human idiopathic focal segmental glomerulosclerosis.

Science.gov (United States)

Dijkman, Henry; Smeets, Bart; van der Laak, Jeroen; Steenbergen, Eric; Wetzels, Jack

2005-10-01

Focal segmental glomerulosclerosis (FSGS) is one of the most common patterns of glomerular injury encountered in human renal biopsies. Epithelial hyperplasia, which can be prominent in FSGS, has been attributed to dedifferentiation and proliferation of podocytes. Based on observations in a mouse model of FSGS, we pointed to the role of parietal epithelial cells (PECs). In the present study we investigated the relative role of PECs and podocytes in human idiopathic FSGS. We performed a detailed study of lesions from a patient with recurrent idiopathic FSGS by serial sectioning, marker analysis and three-dimensional reconstruction of glomeruli. We have studied the expression of markers for podocytes, PECs, mesangial cells, endothelium, and myofibroblasts. We also looked at proliferation and composition of the deposited extracellular matrix (ECM). We found that proliferating epithelial cells in FSGS lesions are negative for podocyte and macrophage markers, but stain for PEC markers. The composition of the matrix deposited by these cells is identical to Bowman's capsule. Our study demonstrates that PECs are crucially involved in the pathogenesis of FSGS lesions.

Plant breeding by using radiation mutation - Selection of herbicide-resistant cell lines by using {gamma}-rays

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyo Yeon [Sunchun University, Sunchun (Korea); Seo, Yong Weon [Korea University, Seoul (Korea)

2000-04-01

In order to develop the herbicide resistant cell lines, micro calli derived from rice anther culture and mature seed of wheat cultivars were irradiated with gamma rays. 1) The callus was dedifferentiated by 7 or 21 day pretreatment at 7 deg. C in two rice cultivars, Ilpumbyeo ad Dongjinbyeo. 2) To check the optimum concentration of herbicide, three herbicides were tested with micro calli. 3) The optimum dose of gamma ray to seeds of wheat seemed to be from 100 to 150 Gy. 4) AFLP and RAPD technique were established to develope herbicide resistant molecular marker in rice. 34 refs., 10 figs., 5 tabs. (Author)

Plasticity of male germline stem cells and their applications in reproductive and regenerative medicine

Directory of Open Access Journals (Sweden)

Zheng Chen

2015-06-01

Full Text Available Spermatogonial stem cells (SSCs, also known as male germline stem cells, are a small subpopulation of type A spermatogonia with the potential of self-renewal to maintain stem cell pool and differentiation into spermatids in mammalian testis. SSCs are previously regarded as the unipotent stem cells since they can only give rise to sperm within the seminiferous tubules. However, this concept has recently been challenged because numerous studies have demonstrated that SSCs cultured with growth factors can acquire pluripotency to become embryonic stem-like cells. The in vivo and in vitro studies from peers and us have clearly revealed that SSCs can directly transdifferentiate into morphologic, phenotypic, and functional cells of other lineages. Direct conversion to the cells of other tissues has important significance for regenerative medicine. SSCs from azoospermia patients could be induced to differentiate into spermatids with fertilization and developmental potentials. As such, SSCs could have significant applications in both reproductive and regenerative medicine due to their unique and great potentials. In this review, we address the important plasticity of SSCs, with focuses on their self-renewal, differentiation, dedifferentiation, transdifferentiation, and translational medicine studies.

Heterogeneous fates and dynamic rearrangement of regenerative epidermis-derived cells during zebrafish fin regeneration.

Science.gov (United States)

Shibata, Eri; Ando, Kazunori; Murase, Emiko; Kawakami, Atsushi

2018-04-13

The regenerative epidermis (RE) is a specialized tissue that plays an essential role in tissue regeneration. However, the fate of the RE during and after regeneration is unknown. In this study, we performed Cre- loxP -mediated cell fate tracking and revealed the fates of a major population of the RE cells that express fibronectin 1b ( fn1b ) during zebrafish fin regeneration. Our study showed that these RE cells are mainly recruited from the inter-ray epidermis, and that they follow heterogeneous cell fates. Early recruited cells contribute to initial wound healing and soon disappear by apoptosis, while the later recruited cells contribute to the regenerated epidermis. Intriguingly, many of these cells are also expelled from the regenerated tissue by a dynamic caudal movement of the epidermis over time, and in turn the loss of epidermal cells is replenished by a global self-replication of basal and suprabasal cells in fin. De-differentiation of non-basal epidermal cells into the basal epidermal cells did not occur during regeneration. Overall, our study reveals the heterogeneous fates of RE cells and a dynamic rearrangement of the epidermis during and after regeneration. © 2018. Published by The Company of Biologists Ltd.

P27Kip1, regulated by glycogen synthase kinase-3β, results in HMBA-induced differentiation of human gastric cancer cells

International Nuclear Information System (INIS)

Wei, Min; Gu, Qinlong; Wang, Zhiwei; Yao, Hongliang; Yang, Zhongyin; Zhang, Qing; Liu, Bingya; Yu, Yingyan; Su, Liping; Zhu, Zhenggang

2011-01-01

Gastric cancer is the second most common cause of global cancer-related mortality. Although dedifferentiation predicts poor prognosis in gastric cancer, the molecular mechanism underlying dedifferentiation, which could provide fundamental insights into tumor development and progression, has yet to be elucidated. Furthermore, the molecular mechanism underlying the effects of hexamethylene bisacetamide (HMBA), a recently discovered differentiation inducer, requires investigation and there are no reported studies concerning the effect of HMBA on gastric cancer. Based on the results of FACS analysis, the levels of proteins involved in the cell cycle or apoptosis were determined using western blotting after single treatments and sequential combinations of HMBA and LiCl. GSK-3β and proton pump were investigated by western blotting after up-regulating Akt expression by Ad-Akt infection. To investigate the effects of HMBA on protein localization and the activities of GSK-3β, CDK2 and CDK4, kinase assays, immunoprecipitation and western blotting were performed. In addition, northern blotting and RNase protection assays were carried out to determine the functional concentration of HMBA. HMBA increased p27Kip1 expression and induced cell cycle arrest associated with gastric epithelial cell differentiation. In addition, treating gastric-derived cells with HMBA induced G0/G1 arrest and up-regulation of the proton pump, a marker of gastric cancer differentiation. Moreover, treatment with HMBA increased the expression and activity of GSK-3β in the nucleus but not the cytosol. HMBA decreased CDK2 activity and induced p27Kip1 expression, which could be rescued by inhibition of GSK-3β. Furthermore, HMBA increased p27Kip1 binding to CDK2, and this was abolished by GSK-3β inhibition. The results presented herein suggest that GSK-3β functions by regulating p27Kip1 assembly with CDK2, thereby playing a critical role in G0/G1 arrest associated with HMBA-induced gastric epithelial

bHLH-O proteins balance the self-renewal and differentiation of Drosophila neural stem cells by regulating Earmuff expression.

Science.gov (United States)

Li, Xiaosu; Chen, Rui; Zhu, Sijun

2017-11-15

Balancing self-renewal and differentiation of stem cells requires differential expression of self-renewing factors in two daughter cells generated from the asymmetric division of the stem cells. In Drosophila type II neural stem cell (or neuroblast, NB) lineages, the expression of the basic helix-loop-helix-Orange (bHLH-O) family proteins, including Deadpan (Dpn) and E(spl) proteins, is required for maintaining the self-renewal and identity of type II NBs, whereas the absence of these self-renewing factors is essential for the differentiation of intermediate neural progenitors (INPs) generated from type II NBs. Here, we demonstrate that Dpn maintains type II NBs by suppressing the expression of Earmuff (Erm). We provide evidence that Dpn and E(spl) proteins suppress Erm by directly binding to C-sites and N-boxes in the cis-regulatory region of erm. Conversely, the absence of bHLH-O proteins in INPs allows activation of erm and Erm-mediated maturation of INPs. Our results further suggest that Pointed P1 (PntP1) mediates the dedifferentiation of INPs resulting from the loss of Erm or overexpression of Dpn or E(spl) proteins. Taken together, these findings reveal mechanisms underlying the regulation of the maintenance of type II NBs and differentiation of INPs through the differential expression of bHLH-O family proteins. Copyright © 2017 Elsevier Inc. All rights reserved.

Taurine Promotes the Cartilaginous Differentiation of Human Umbilical Cord-Derived Mesenchymal Stem Cells in Vitro.

Science.gov (United States)

Yao, Xiuhua; Huang, Huiling; Li, Zhou; Liu, Xiaohua; Fan, Weijia; Wang, Xinping; Sun, Xuelian; Zhu, Jianmin; Zhou, Hongrui; Wei, Huaying

2017-08-01

Taurine has been reported to influence osteogenic differentiation, but the role of taurine on cartilaginous differentiation using human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) remains unclear. In this study, we investigated the effect of taurine (0, 1, 5 and 10 mM) on the proliferation and chondrogenesis of hUC-MSCs by analyzing cell proliferation, accumulation of glycosaminoglycans and expression of cartilage specific mRNA. The results show though taurine did not affected the proliferation of hUC-MSCs, 5 mM of taurine is sufficient to enhanced the accumulation of glycosaminoglycans and up-regulate cartilage specific mRNA expression, namely collagen type II, aggrecan and SOX9. Taurine also inhibits chondrocyte dedifferentiation by reducing expression of collagen type I mRNA. Taken together, our study reveals that taurine promotes and maintains the chondrogenesis of hUC-MSCs.

Loss of end-differentiated β-cell phenotype following pancreatic islet transplantation.

Science.gov (United States)

Anderson, S J; White, M G; Armour, S L; Maheshwari, R; Tiniakos, D; Muller, Y D; Berishvili, E; Berney, T; Shaw, J A M

2018-03-01

Replacement of pancreatic β-cells through deceased donor islet transplantation is a proven therapy for preventing recurrent life-threatening hypoglycemia in type 1 diabetes. Although near-normal glucose levels and insulin independence can be maintained for many years following successful islet transplantation, restoration of normal functional β-cell mass has remained elusive. It has recently been proposed that dedifferentiation/plasticity towards other endocrine phenotypes may play an important role in stress-induced β-cell dysfunction in type 2 diabetes. Here we report loss of end-differentiated β-cell phenotype in 2 intraportal islet allotransplant recipients. Despite excellent graft function and sustained insulin independence, all examined insulin-positive cells had lost expression of the end-differentiation marker, urocortin-3, or appeared to co-express the α-cell marker, glucagon. In contrast, no insulin + /urocortin-3 - cells were seen in nondiabetic deceased donor control pancreatic islets. Loss of end-differentiated phenotype may facilitate β-cell survival during the stresses associated with islet isolation and culture, in addition to sustained hypoxia following engraftment. As further refinements in islet isolation and culture are made in parallel with exploration of alternative β-cell sources, graft sites, and ultimately fully vascularized bioengineered insulin-secreting microtissues, differentiation status immunostaining provides a novel tool to assess whether fully mature β-cell phenotype has been maintained. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

Vascular smooth muscle cells exhibit a progressive loss of rigidity with serial culture passaging.

Science.gov (United States)

Dinardo, Carla Luana; Venturini, Gabriela; Omae, Samantha Vieira; Zhou, Enhua H; da Motta-Leal-Filho, Joaquim Maurício; Dariolli, Rafael; Krieger, José Eduardo; Alencar, Adriano Mesquita; Costa Pereira, Alexandre

2012-01-01

One drawback of in vitro cell culturing is the dedifferentiation process that cells experience. Smooth muscle cells (SMC) also change molecularly and morphologically with long term culture. The main objective of this study was to evaluate if culture passages interfere in vascular SMC mechanical behavior. SMC were obtained from five different porcine arterial beds. Optical magnetic twisting cytometry (OMTC) was used to characterize mechanically vascular SMC from different cultures in distinct passages and confocal microscopy/western blotting, to evaluate cytoskeleton and extracellular matrix proteins. We found that vascular SMC rigidity or viscoelastic complex modulus (G) decreases with progression of passages. A statistically significant negative correlation between G and passage was found in four of our five cultures studied. Phalloidin-stained SMC from higher passages exhibited lower mean signal intensity per cell (confocal microscopy) and quantitative western blotting analysis showed a decrease in collagen I content throughout passages. We concluded that vascular SMC progressively lose their stiffness with serial culture passaging. Thus, limiting the number of passages is essential for any experiment measuring viscoelastic properties of SMC in culture.

Effect of Wnt-1 inducible signaling pathway protein-2 (WISP-2/CCN5), a downstream protein of Wnt signaling, on adipocyte differentiation

International Nuclear Information System (INIS)

Inadera, Hidekuni; Shimomura, Akiko; Tachibana, Shinjiro

2009-01-01

Wnt signaling negatively regulates adipocyte differentiation, and ectopic expression of Wnt-1 in 3T3-L1 cells induces several downstream molecules of Wnt signaling, including Wnt-1 inducible signaling pathway protein (WISP)-2. In this study, we examined the role of WISP-2 in the process of adipocyte differentiation using an in vitro cell culture system. In the differentiation of 3T3-L1 cells, WISP-2 expression was observed in growing cells and declined thereafter. In the mitotic clonal expansion phase of adipocyte differentiation, WISP-2 expression was transiently down-regulated concurrently with up-regulation of CCAAT/enhancer-binding protein δ expression. Treatment of 3T3-L1 cells in the differentiation medium with lithium, an activator of Wnt signaling, inhibited the differentiation process with concomitant induction of WISP-2. Treatment of differentiated cells with lithium induced de-differentiation as evidenced by profound reduction of peroxisome proliferator-activator receptor γ expression and concomitant induction of WISP-2. However, de-differentiation of differentiated cells induced by tumor necrosis factor-α did not induce WISP-2 expression. To directly examine the effect of WISP-2 on adipocyte differentiation, 3T3-L1 cells were infected with a retrovirus carrying WISP-2. Although forced expression of WISP-2 inhibited preadipocyte proliferation, it had no effect on adipocyte differentiation. Thus, although WISP-2 is a downstream protein of Wnt signaling, the role of WISP-2 on adipocyte differentiation may be marginal, at least in this in vitro culture model.

Generating autologous hematopoietic cells from human-induced pluripotent stem cells through ectopic expression of transcription factors.

Science.gov (United States)

Hwang, Yongsung; Broxmeyer, Hal E; Lee, Man Ryul

2017-07-01

Hematopoietic cell transplantation (HCT) is a successful treatment modality for patients with malignant and nonmalignant disorders, usually when no other treatment option is available. The cells supporting long-term reconstitution after HCT are the hematopoietic stem cells (HSCs), which can be limited in numbers. Moreover, finding an appropriate human leukocyte antigen-matched donor can be problematic. If HSCs can be stably produced in large numbers from autologous or allogeneic cell sources, it would benefit HCT. Induced pluripotent stem cells (iPSCs) established from patients' own somatic cells can be differentiated into hematopoietic cells in vitro. This review will highlight recent methods for regulating human (h) iPSC production of HSCs and more mature blood cells. Advancements in transcription factor-mediated regulation of the developmental stages of in-vivo hematopoietic lineage commitment have begun to provide an understanding of the molecular mechanism of hematopoiesis. Such studies involve not only directed differentiation in which transcription factors, specifically expressed in hematopoietic lineage-specific cells, are overexpressed in iPSCs, but also direct conversion in which transcription factors are introduced into patient-derived somatic cells which are dedifferentiated to hematopoietic cells. As iPSCs derived from patients suffering from genetically mutated diseases would express the same mutated genetic information, CRISPR-Cas9 gene editing has been utilized to differentiate genetically corrected iPSCs into normal hematopoietic cells. IPSCs provide a model for molecular understanding of disease, and also may function as a cell population for therapy. Efficient differentiation of patient-specific iPSCs into HSCs and progenitor cells is a potential means to overcome limitations of such cells for HCT, as well as for providing in-vitro drug screening templates as tissue-on-a-chip models.

Solar cells, structures including organometallic halide perovskite monocrystalline films, and methods of preparation thereof

KAUST Repository

Bakr, Osman M.

2017-03-02

Embodiments of the present disclosure provide for solar cells including an organometallic halide perovskite monocrystalline film (see fig. 1.1B), other devices including the organometallic halide perovskite monocrystalline film, methods of making organometallic halide perovskite monocrystalline film, and the like.

Protocol for Isolation of Primary Human Hepatocytes and Corresponding Major Populations of Non-parenchymal Liver Cells

Science.gov (United States)

Pfeiffer, Elisa; Zeilinger, Katrin; Seehofer, Daniel; Damm, Georg

2016-01-01

Beside parenchymal hepatocytes, the liver consists of non-parenchymal cells (NPC) namely Kupffer cells (KC), liver endothelial cells (LEC) and hepatic Stellate cells (HSC). Two-dimensional (2D) culture of primary human hepatocyte (PHH) is still considered as the "gold standard" for in vitro testing of drug metabolism and hepatotoxicity. It is well-known that the 2D monoculture of PHH suffers from dedifferentiation and loss of function. Recently it was shown that hepatic NPC play a central role in liver (patho-) physiology and the maintenance of PHH functions. Current research focuses on the reconstruction of in vivo tissue architecture by 3D- and co-culture models to overcome the limitations of 2D monocultures. Previously we published a method to isolate human liver cells and investigated the suitability of these cells for their use in cell cultures in Experimental Biology and Medicine1. Based on the broad interest in this technique the aim of this article was to provide a more detailed protocol for the liver cell isolation process including a video, which will allow an easy reproduction of this technique. Human liver cells were isolated from human liver tissue samples of surgical interventions by a two-step EGTA/collagenase P perfusion technique. PHH were separated from the NPC by an initial centrifugation at 50 x g. Density gradient centrifugation steps were used for removal of dead cells. Individual liver cell populations were isolated from the enriched NPC fraction using specific cell properties and cell sorting procedures. Beside the PHH isolation we were able to separate KC, LEC and HSC for further cultivation. Taken together, the presented protocol allows the isolation of PHH and NPC in high quality and quantity from one donor tissue sample. The access to purified liver cell populations could allow the creation of in vivo like human liver models. PMID:27077489

Dedifferentiation of tobacco cells is associated with ribosomal RNA gene hypomethylation, increased transcription, and chromatin alterations

Czech Academy of Sciences Publication Activity Database

Koukalová, Blažena; Fojtová, Miloslava; Lim, Yoong Kar; Fulneček, Jaroslav; Leitch, Rowland Andrew; Kovařík, Aleš

2005-01-01

Roč. 139, - (2005), s. 275-286 ISSN 0032-0889 Institutional research plan: CEZ:AV0Z50040507 Keywords : pluripotent tobacco cells * epigenetic changes Subject RIV: BO - Biophysics Impact factor: 6.114, year: 2005

The potential of induced pluripotent stem cell derived hepatocytes.

Science.gov (United States)

Hannoun, Zara; Steichen, Clara; Dianat, Noushin; Weber, Anne; Dubart-Kupperschmitt, Anne

2016-07-01

Orthotopic liver transplantation remains the only curative treatment for liver disease. However, the number of patients who die while on the waiting list (15%) has increased in recent years as a result of severe organ shortages; furthermore the incidence of liver disease is increasing worldwide. Clinical trials involving hepatocyte transplantation have provided encouraging results. However, transplanted cell function appears to often decline after several months, necessitating liver transplantation. The precise aetiology of the loss of cell function is not clear, but poor engraftment and immune-mediated loss appear to be important factors. Also, primary human hepatocytes (PHH) are not readily available, de-differentiate, and die rapidly in culture. Hepatocytes are available from other sources, such as tumour-derived human hepatocyte cell lines and immortalised human hepatocyte cell lines or porcine hepatocytes. However, all these cells suffer from various limitations such as reduced or differences in functions or risk of zoonotic infections. Due to their significant potential, one possible inexhaustible source of hepatocytes is through the directed differentiation of human induced pluripotent stem cells (hiPSCs). This review will discuss the potential applications and existing limitations of hiPSC-derived hepatocytes in regenerative medicine, drug screening, in vitro disease modelling and bioartificial livers. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Electrolyte for a lithium/thionyl chloride electric cell, a method of preparing said electrolyte and an electric cell which includes said electrolyte

Energy Technology Data Exchange (ETDEWEB)

Gabano, J.

1983-03-01

An electrolyte for an electric cell whose negative active material is constituted by lithium and whose positive active material is constituted by thionyl chloride. The electrolyte contains at least one solvent and at least one solute, said solvent being thionyl chloride and said solute being chosen from the group which includes lithium tetrachloroaluminate and lithium hexachloroantimonate. According to the invention said electrolyte further includes a complex chosen from the group which includes AlCl/sub 3/,SO/sub 2/ and SbCl/sub 5/,SO/sub 2/. The voltage rise of electric cells which include such an electrolyte takes negligible time.

Generation and characterization of human smooth muscle cell lines derived from atherosclerotic plaque.

Science.gov (United States)

Bonin, L R; Madden, K; Shera, K; Ihle, J; Matthews, C; Aziz, S; Perez-Reyes, N; McDougall, J K; Conroy, S C

1999-03-01

The study of atherogenesis in humans has been restricted by the limited availability and brief in vitro life span of plaque smooth muscle cells (SMCs). We describe plaque SMC lines with extended life spans generated by the expression of the human papillomavirus (HPV)-16 E6 and E7 genes, which has been shown to extend the life span of normal adult human aortic SMCs. Resulting cell lines (pdSMC1A and 2) demonstrated at least 10-fold increases in life span; pdSMC1A became immortal. The SMC identity of both pdSMC lines was confirmed by SM22 mRNA expression. pdSMC2 were generally diploid but with various structural and numerical alterations; pdSMC1A demonstrated several chromosomal abnormalities, most commonly -Y, +7, -13, anomalies previously reported in both primary pdSMCs and atherosclerotic tissue. Confluent pdSMC2 appeared grossly similar to HPV-16 E6/E7-expressing normal adult aortic SMCs (AASMCs), exhibiting typical SMC morphology/growth patterns; pdSMC1A displayed irregular cell shape/organization with numerous mitotic figures. Dedifferentiation to a synthetic/proliferative phenotype has been hypothesized as a critical step in atherogenesis, because rat neonatal SMCs and adult intimal SMCs exhibit similar gene expression patterns. To confirm that our pdSMC lines likewise express this apparent plaque phenotype, osteopontin, platelet-derived growth factor B, and elastin mRNA levels were determined in pdSMC1A, pdSMC2, and AASMCs. However, no significant increases in osteopontin or platelet-derived growth factor B expression levels were observed in either pdSMC compared with AASMCs. pdSMC2 alone expressed high levels of elastin mRNA. Lower levels of SM22 mRNA in pdSMC1A suggested greater dedifferentiation and/or additional population doublings in pdSMC1A relative to pdSMC2. Both pdSMC lines (particularly 1A) demonstrated high message levels for matrix Gla protein, previously reported to be highly expressed by human neointimal SMCs in vitro. These results describe 2

Mapping of Carboxypeptidase M in Normal Human Kidney and Renal Cell Carcinoma

Science.gov (United States)

Denis, Catherine J.; Van Acker, Nathalie; De Schepper, Stefanie; De Bie, Martine; Andries, Luc; Fransen, Erik; Hendriks, Dirk; Kockx, Mark M.

2013-01-01

Although the kidney generally has been regarded as an excellent source of carboxypeptidase M (CPM), little is known about its renal-specific expression level and distribution. This study provides a detailed localization of CPM in healthy and diseased human kidneys. The results indicate a broad distribution of CPM along the renal tubular structures in the healthy kidney. CPM was identified at the parietal epithelium beneath the Bowman’s basement membrane and in glomerular mesangial cells. Capillaries, podocytes, and most interstitial cells were CPM negative. Tumor cells of renal cell carcinoma subtypes lose CPM expression upon dedifferentiation. Tissue microarray analysis demonstrated a correlation between low CPM expression and tumor cell type. CPM staining was intense on phagocytotic tumor-associated macrophages. Immunoreactive CPM was also detected in the tumor-associated vasculature. The absence of CPM in normal renal blood vessels points toward a role for CPM in angiogenesis. Coexistence of CPM and the epidermal growth factor receptor (EGFR) was detected in papillary renal cell carcinoma. However, the different subcellular localization of CPM and EGFR argues against an interaction between these h proteins. The description of the distribution of CPM in human kidney forms the foundation for further study of the (patho)physiological activities of CPM in the kidney. PMID:23172796

Trans-differentiation via Epigenetics: A New Paradigm in the Bone Regeneration.

Science.gov (United States)

Cho, Young-Dan; Ryoo, Hyun-Mo

2018-02-01

In regenerative medicine, growing cells or tissues in the laboratory is necessary when damaged cells can not heal by themselves. Acquisition of the required cells from the patient's own cells or tissues is an ideal option without additive side effects. In this context, cell reprogramming methods, including the use of induced pluripotent stem cells (iPSCs) and trans-differentiation, have been widely studied in regenerative research. Both approaches have advantages and disadvantages, and the possibility of de-differentiation because of the epigenetic memory of iPSCs has strengthened the need for controlling the epigenetic background for successful cell reprogramming. Therefore, interest in epigenetics has increased in the field of regenerative medicine. Herein, we outline in detail the cell trans-differentiation method using epigenetic modification for bone regeneration in comparison to the use of iPSCs.

Testis cancer: the forgotten poster child.

Science.gov (United States)

Raghavan, Derek

2014-07-15

In germ cell cancers, the unique reversibility of malignancy and the balance between somatic differentiation and dedifferentiation may be critical to late relapse that is dominated by non-germ cell elements. Targeting regulators of differentiation may provide a solution, and this may be elucidated via serial liquid biopsies (via circulating tumor cells). ©2014 American Association for Cancer Research.

Myxoinflammatory fibroblastic sarcoma: spectrum of disease and imaging presentation

Energy Technology Data Exchange (ETDEWEB)

Gaetke-Udager, Kara; Yablon, Corrie M.; Morag, Yoav [University of Michigan Health System, Department of Radiology, Ann Arbor, MI (United States); Lucas, David R. [University of Michigan Health System, Department of Pathology, Ann Arbor, MI (United States)

2016-03-15

To describe the imaging findings of a series of myxoinflammatory fibroblastic sarcomas (MFSs) from our institution, including a case of dedifferentiated MFS and two cases with areas of high-grade tumor, in addition to typical cases of low-grade tumor. To correlate the imaging findings with the pathologic features of these tumors. IRB approval was obtained. Retrospective search of the pathology database at our institution from 2000 to 2015 identified seven cases of MFS with available imaging. Imaging, pathology, and clinical data were reviewed. Unlike the majority of well-differentiated tumors in our series (four cases), one tumor showed dedifferentiation and two cases had areas of high-grade tumor. The dedifferentiated tumor showed peripheral post-contrast enhancement. One case with a substantial high-grade component showed osseous destruction and peripheral enhancement in the high-grade area, while the low-grade component enhanced diffusely. The second case had a small high-grade area and showed diffuse enhancement. All three of these cases had non-acral locations and lacked association with a tendon. The four cases of low-grade MFS demonstrated diffuse enhancement, were located in the distal extremities, and were associated with a tendon. The imaging findings of dedifferentiated and high-grade MFS differ from the more typical low-grade tumors in that they have nonenhancing areas, a non-acral location, lack association with a tendon, and may involve bone. The radiologist should be aware that MFS represents a spectrum that includes low-grade tumors, tumors with high-grade areas, and tumors with dedifferentiation and that this spectrum presents with differing imaging features. (orig.)

MicroRNAs: regulators of oncogenesis and stemness

Directory of Open Access Journals (Sweden)

Papagiannakopoulos Thales

2008-06-01

Full Text Available Abstract MicroRNAs (miRNAs are essential post-transcriptional regulators that determine cell identity and fate. Aberrant expression of miRNAs can lead to diseases, including cancer. Expression of many miRNAs in the de-differentiated brain tumor cancer stem cells resembles that of neural stem cells. In this issue of BMC Medicine, Silber et al provide evidence of the expression of such miRNAs and their potential to mediate differentiation in both stem cell populations. In this commentary, we discuss the known functions of miRNAs in cancer and stem cells, their therapeutic potential and how the findings of Silber et al provide insight into the role of miR-124/miR-137 dysregulation in glioblastomas.

The thiol compounds glutathione and homoglutathione differentially affect cell development in alfalfa (Medicago sativa L.).

Science.gov (United States)

Pasternak, Taras; Asard, Han; Potters, Geert; Jansen, Marcel A K

2014-01-01

Glutathione (GSH) is an important scavenger of Reactive Oxygen Species (ROS), precursor of metal chelating phytochelatins, xenobiotic defence compound and regulator of cell proliferation. Homoglutathione (hGSH) is a GSH homologue that is present in several taxa in the family of Fabaceae. It is thought that hGSH performs many of the stress-defence roles typically ascribed to GSH, yet little is known about the potential involvement of hGSH in controlling cell proliferation. Here we show that hGSH/GSH ratios vary across organs and cells and that these changes in hGSH/GSH ratio occur during dedifferentiation and/or cell cycle activation events. The use of a GSH/hGSH biosynthesis inhibitor resulted in impaired cytokinesis in isolated protoplasts, showing the critical importance of these thiol-compounds for cell division. However, exposure of isolated protoplasts to exogenous GSH accelerated cytokinesis, while exogenous hGSH was found to inhibit the same process. We conclude that GSH and hGSH have distinct functional roles in cell cycle regulation in Medicago sativa L. GSH is associated with meristemic cells, and promotes cell cycle activation and induction of somatic embryogenesis, while hGSH is associated with differentiated cells and embryo proliferation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Characterisation of the cell line HC-AFW1 derived from a pediatric hepatocellular carcinoma.

Directory of Open Access Journals (Sweden)

Sorin Armeanu-Ebinger

Full Text Available Current treatment of paediatric hepatocellular carcinoma (HCC is often inefficient due to advanced disease at diagnosis and resistance to common drugs. The aim of this study was to generate a cell line derived from a paediatric HCC in order to expand research in this field. We established the HC-AFW1 cell line from a liver neoplasm of a 4-year-old boy through culturing of primary tumor specimens. The cell line has been stable for over one year of culturing and has a doubling time of 40 h. The tumour cells have an epithelial histology and express HCC-associated proteins such as Alpha-fetoprotein (AFP, Glypican 3, E-cadherin, CD10, CD326, HepPar1 and Vimentin. Forty-nine amino acids in exon 3 of β-Catenin that involve the phosphorylation sites of GSK3 were absent and β-Catenin is detectable in the cell nuclei. Cytogenetic analysis revealed large anomalies in the chromosomal map. Several alterations of gene copy numbers were detected by genome-wide SNP array. Among the different drugs tested, cisplatin and irinotecan showed effective inhibition of tumour cell growth in a proliferation assay at concentrations below 5 µg/ml. Subcutaneous xenotransplantation of HC-AFW1 cells into NOD/SCID mice resulted in fast growing dedifferentiated tumours with high levels of serum AFP. Histological analyses of the primary tumour and xenografts included national and international expert pathological review. Consensus reading characterised the primary tumour and the HC-AFW1-derived tumours as HCC. HC-AFW1 is the first cell line derived from a paediatric HCC without a background of viral hepatitis or cirrhosis and represents a valuable tool for investigating the biology of and therapeutic strategies for childhood HCC.

Donor‐Dependent and Other Nondefined Factors Have Greater Influence on the Hepatic Phenotype Than the Starting Cell Type in Induced Pluripotent Stem Cell Derived Hepatocyte‐Like Cells

Science.gov (United States)

Heslop, James A.; Kia, Richard; Pridgeon, Christopher S.; Sison‐Young, Rowena L.; Liloglou, Triantafillos; Elmasry, Mohamed; Fenwick, Stephen W.; Mills, John S.; Kitteringham, Neil R.; Park, Bong K.

2017-01-01

Abstract Drug‐induced liver injury is the greatest cause of post‐marketing drug withdrawal; therefore, substantial resources are directed toward triaging potentially dangerous new compounds at all stages of drug development. One of the major factors preventing effective screening of new compounds is the lack of a predictive in vitro model of hepatotoxicity. Primary human hepatocytes offer a metabolically relevant model for which the molecular initiating events of hepatotoxicity can be examined; however, these cells vary greatly between donors and dedifferentiate rapidly in culture. Induced pluripotent stem cell (iPSC)‐derived hepatocyte‐like cells (HLCs) offer a reproducible, physiologically relevant and genotypically normal model cell; however, current differentiation protocols produce HLCs with a relatively immature phenotype. During the reprogramming of somatic cells, the epigenome undergoes dramatic changes; however, this “resetting” is a gradual process, resulting in an altered differentiation propensity, skewed toward the lineage of origin, particularly in early passage cultures. We, therefore, performed a comparison of human hepatocyte‐ and dermal fibroblast‐derived iPSCs, assessing the impact of epigenetic memory at all stages of HLC differentiation. These results provide the first isogenic assessment of the starting cell type in human iPSC‐derived HLCs. Despite a trend toward improvement in hepatic phenotype in albumin secretion and gene expression, few significant differences in hepatic differentiation capacity were found between hepatocyte and fibroblast‐derived iPSCs. We conclude that the donor and inter‐clonal differences have a greater influence on the hepatocyte phenotypic maturity than the starting cell type. Therefore, it is not necessary to use human hepatocytes for generating iPSC‐derived HLCs. Stem Cells Translational Medicine 2017;6:1321–1331 PMID:28456008

Pediatric littoral cell angioma of the spleen: multimodality imaging including diffusion-weighted imaging

Energy Technology Data Exchange (ETDEWEB)

Ertan, Gulhan; Tekes, Aylin; Huisman, Thierry A.G.M. [Johns Hopkins Hospital, Division of Pediatric Radiology, Department of Radiology and Radiological Science, Baltimore, MD (United States); Mitchell, Sally [Johns Hopkins Hospital, Division of Cardiovascular and Interventional Radiology, Department of Radiology and Radiological Science, Baltimore (United States); Keefer, Jeffrey [Johns Hopkins Hospital, Division of Pediatric Hematology, Department of Pediatrics, Baltimore, MD (United States)

2009-10-15

Littoral cell angioma (LCA) is a rare primary splenic vascular tumor originating from littoral cells lining the splenic red pulp sinuses. LCAs are rarely seen in children. We present the US, CT, and MRI findings including diffusion-weighted imaging (DWI) in a 2-year-old boy with histologically proven LCA. Previous studies on liver lesions have shown that DWI allows differentiation of vascular tumors from primary neoplasms and metastatic disease. The current case indicates that increased ADC values within the splenic lesions suggest a vascular etiology, which might help narrow the differential diagnosis. (orig.)

Pediatric littoral cell angioma of the spleen: multimodality imaging including diffusion-weighted imaging

International Nuclear Information System (INIS)

Ertan, Gulhan; Tekes, Aylin; Huisman, Thierry A.G.M.; Mitchell, Sally; Keefer, Jeffrey

2009-01-01

Littoral cell angioma (LCA) is a rare primary splenic vascular tumor originating from littoral cells lining the splenic red pulp sinuses. LCAs are rarely seen in children. We present the US, CT, and MRI findings including diffusion-weighted imaging (DWI) in a 2-year-old boy with histologically proven LCA. Previous studies on liver lesions have shown that DWI allows differentiation of vascular tumors from primary neoplasms and metastatic disease. The current case indicates that increased ADC values within the splenic lesions suggest a vascular etiology, which might help narrow the differential diagnosis. (orig.)

to view fulltext PDF

Indian Academy of Sciences (India)

2016-11-30

Nov 30, 2016 ... tion of the autosomes and sex-chromosomes of maternal origin from those of ...... of being able to rejuvenate cells without de-differentiation are self-evident. ...... Singh PB 1994 Molecular mechanisms of cellular determination:.

Inhibition of miR-146b expression increases radioiodine-sensitivity in poorly differential thyroid carcinoma via positively regulating NIS expression

Energy Technology Data Exchange (ETDEWEB)

Li, Luchuan; Lv, Bin; Chen, Bo [Department of General Surgery, Shandong University Qilu Hospital, Jinan, Shandong 250012 (China); Guan, Ming [Department of General Surgery, Qihe People' s Hospital, Qihe, Shandong 251100 (China); Sun, Yongfeng [Department of General Surgery, Licheng District People' s Hospital, Jinan, Shandong 250115 (China); Li, Haipeng [Department of General Surgery, Caoxian People' s Hospital, Caoxian, Shandong 274400 (China); Zhang, Binbin; Ding, Changyuan; He, Shan [Department of General Surgery, Shandong University Qilu Hospital, Jinan, Shandong 250012 (China); Zeng, Qingdong, E-mail: qingdz0201@163.com [Department of General Surgery, Shandong University Qilu Hospital, Jinan, Shandong 250012 (China)

2015-07-10

Dedifferentiated thyroid carcinoma (DTC) with the loss of radioiodine uptake (RAIU) is often observed in clinical practice under radioiodine therapy, indicating the challenge for poor prognosis. MicroRNA (miRNA) has emerged as a promising therapeutic target in many diseases; yet, the role of miRNAs in RAIU has not been generally investigated. Based on recent studies about miRNA expression in papillary or follicular thyroid carcinomas, the expression profiles of several thyroid relative miRNAs were investigated in one DTC cell line, derived from normal DTC cells by radioiodine treatment. The top candidate miR-146b, with the most significant overexpression profiles in dedifferentiated cells, was picked up. Further research found that miR-146b could be negatively regulated by histone deacetylase 3 (HDAC3) in normal cells, indicating the correlation between miR-146b and Na{sup +}/I{sup −} symporter (NIS)-mediated RAIU. Fortunately, it was confirmed that miR-146b could regulate NIS expression/activity; what is more important, miR-146b interference would contribute to the recovery of radioiodine-sensitivity in dedifferentiated cells via positively regulating NIS. In the present study, it was concluded that NIS-mediated RAIU could be modulated by miR-146b; accordingly, miR-146b might serve as one of targets to enhance efficacy of radioactive therapy against poorly differential thyroid carcinoma (PDTC). - Highlights: • Significant upregulated miR-146b was picked up from thyroid relative miRNAs in DTC. • MiR-146b was negatively regulated by HDAC3 in normal thyroid carcinoma cells. • NIS activity and expression could be regulated by miR-146b in thyroid carcinoma. • MiR-146b inhibition could recover the decreased radioiodine-sensitivity of DTC cells.

Plasma Cell Neoplasms (Including Multiple Myeloma)—Patient Version

Science.gov (United States)

Plasma cell neoplasms occur when abnormal plasma cells form cancerous tumors. When there is only one tumor, the disease is called a plasmacytoma. When there are multiple tumors, it is called multiple myeloma. Start here to find information on plasma cell neoplasms treatment, research, and statistics.

Mechanosensing of matrix by stem cells: From matrix heterogeneity, contractility, and the nucleus in pore-migration to cardiogenesis and muscle stem cells in vivo.

Science.gov (United States)

Smith, Lucas; Cho, Sangkyun; Discher, Dennis E

2017-11-01

Stem cells are particularly 'plastic' cell types that are induced by various cues to become specialized, tissue-functional lineages by switching on the expression of specific gene programs. Matrix stiffness is among the cues that multiple stem cell types can sense and respond to. This seminar-style review focuses on mechanosensing of matrix elasticity in the differentiation or early maturation of a few illustrative stem cell types, with an intended audience of biologists and physical scientists. Contractile forces applied by a cell's acto-myosin cytoskeleton are often resisted by the extracellular matrix and transduced through adhesions and the cytoskeleton ultimately into the nucleus to modulate gene expression. Complexity is added by matrix heterogeneity, and careful scrutiny of the evident stiffness heterogeneity in some model systems resolves some controversies concerning matrix mechanosensing. Importantly, local stiffness tends to dominate, and 'durotaxis' of stem cells toward stiff matrix reveals a dependence of persistent migration on myosin-II force generation and also rigid microtubules that confer directionality. Stem and progenitor cell migration in 3D can be further affected by matrix porosity as well as stiffness, with nuclear size and rigidity influencing niche retention and fate choices. Cell squeezing through rigid pores can even cause DNA damage and genomic changes that contribute to de-differentiation toward stem cell-like states. Contraction of acto-myosin is the essential function of striated muscle, which also exhibit mechanosensitive differentiation and maturation as illustrated in vivo by beating heart cells and by the regenerative mobilization of skeletal muscle stem cells. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nuclear deformation and expression change of cartilaginous genes during in vitro expansion of chondrocytes

International Nuclear Information System (INIS)

Hoshiba, Takashi; Yamada, Tomoe; Lu, Hongxu; Kawazoe, Naoki; Tateishi, Tetsuya; Chen, Guoping

2008-01-01

Cartilaginous gene expression decreased when chondrocytes were expanded on cell-culture plates. Understanding the dedifferentiation mechanism may provide valuable insight into cartilage tissue engineering. Here, we demonstrated the relationship between the nuclear shape and gene expression during in vitro expansion culture of chondrocytes. Specifically, the projected nuclear area increased and cartilaginous gene expressions decreased during in vitro expansion culture. When the nuclear deformation was recovered by cytochalasin D treatment, aggrecan expression was up-regulated and type I collagen (Col1a2) expression was down-regulated. These results suggest that nuclear deformation may be one of the mechanisms for chondrocyte dedifferentiation during in vitro expansion culture

Gene therapy of thyroid carcinoma

International Nuclear Information System (INIS)

Zheng Wei; Tan Jian

2007-01-01

Normally, differentiated thyroid carcinoma(DTC) is a disease of good prognosis, but about 30% of the tumors are dedifferentiate, which are inaccessible to standard therapeutic procedures such as 'operation, 131 I therapy and thyroid hormone'. Both internal and abroad experts are researching a new therapy of dedifferentiated thyroid carcinoma--gene therapy. Many of them utilize methods of it, but follow different strategies: (1) transduction of the thyroid sodium/iodide transporter gene to make tissues that do not accumulate iodide treatable by 131 I therapy; (2) strengthening of the anti-tumor immune response; (3) suicide gene therapy; (4) depression the generation of tumor cells; (5) gene therapy of anti- vascularization. (authors)

Expression of crystallins in cell cultures of lens epithelium following inhibition of mitosis by X-rays. Expression von Kristallinen in kultivierten durch Roentgenstrahlen mitotisch arretierten Linsenepithelzellen

Energy Technology Data Exchange (ETDEWEB)

Henrich, C.

1988-01-18

Cells from bovine lens epithelium (B26 line) were cultivated in vitro and examined to characterize their growth behaviour patterns. The question as to whether those cells would still show the ability of synthetizing crystallins was investigated on the basis of indirect immunofluorescene using both polyspecific and monospecific antisera. The findings revealed confirmed the results of former studies according to which dedifferentiation processes and marked reductions of crystallin synthesis occurred in rapidly proliferating epithelial cells cultivated in vitro. Inhibitions of proliferation were followed by a time-dependent reappearance of crystallins. The study described here was primarily focused on the arrest of cell proliferation after X-irradiation. It was found that an inhibition of cells during the G{sub o} phase may be achieved through hydroxyurea, indomethacin and X-rays. Beta crystallins can better be expressed than alpha crystallins and the expression of gamma crystallins was seen to be rather poor. (orig./MG).

Donor-Dependent and Other Nondefined Factors Have Greater Influence on the Hepatic Phenotype Than the Starting Cell Type in Induced Pluripotent Stem Cell Derived Hepatocyte-Like Cells.

Science.gov (United States)

Heslop, James A; Kia, Richard; Pridgeon, Christopher S; Sison-Young, Rowena L; Liloglou, Triantafillos; Elmasry, Mohamed; Fenwick, Stephen W; Mills, John S; Kitteringham, Neil R; Goldring, Chris E; Park, Bong K

2017-05-01

Drug-induced liver injury is the greatest cause of post-marketing drug withdrawal; therefore, substantial resources are directed toward triaging potentially dangerous new compounds at all stages of drug development. One of the major factors preventing effective screening of new compounds is the lack of a predictive in vitro model of hepatotoxicity. Primary human hepatocytes offer a metabolically relevant model for which the molecular initiating events of hepatotoxicity can be examined; however, these cells vary greatly between donors and dedifferentiate rapidly in culture. Induced pluripotent stem cell (iPSC)-derived hepatocyte-like cells (HLCs) offer a reproducible, physiologically relevant and genotypically normal model cell; however, current differentiation protocols produce HLCs with a relatively immature phenotype. During the reprogramming of somatic cells, the epigenome undergoes dramatic changes; however, this "resetting" is a gradual process, resulting in an altered differentiation propensity, skewed toward the lineage of origin, particularly in early passage cultures. We, therefore, performed a comparison of human hepatocyte- and dermal fibroblast-derived iPSCs, assessing the impact of epigenetic memory at all stages of HLC differentiation. These results provide the first isogenic assessment of the starting cell type in human iPSC-derived HLCs. Despite a trend toward improvement in hepatic phenotype in albumin secretion and gene expression, few significant differences in hepatic differentiation capacity were found between hepatocyte and fibroblast-derived iPSCs. We conclude that the donor and inter-clonal differences have a greater influence on the hepatocyte phenotypic maturity than the starting cell type. Therefore, it is not necessary to use human hepatocytes for generating iPSC-derived HLCs. Stem Cells Translational Medicine 2017;6:1321-1331. © 2017 The Authors Stem Cells Translational Medicine published by Wiley Periodicals, Inc. on behalf of Alpha

Persistent STAT3 Activation in Colon Cancer Is Associated with Enhanced Cell Proliferation and Tumor Growth

Directory of Open Access Journals (Sweden)

Florian M. Corvinus

2005-06-01

Full Text Available Colorectal carcinoma (CRC is a major cause of morbidity and mortality in Western countries. It has so far been molecularly defined mainly by alterations of the Wnt pathway. We show here for the first time that aberrant activities of the signal transducer and activator of transcription STAT3 actively contribute to this malignancy and, thus, are a potential therapeutic target for CRC. Constitutive STAT3 activity was found to be abundant in dedifferentiated cancer cells and infiltrating lymphocytes of CRC samples, but not in non-neoplastic colon epithelium. Cell lines derived from malignant colorectal tumors lost persistent STAT3 activity in culture. However, implantation of colon carcinoma cells into nude mice resulted in restoration of STAT3 activity, suggesting a role of an extracellular stimulus within the tumor microenvironment as a trigger for STAT activation. STAT3 activity in CRC cells triggered through interleukin-6 or through a constitutively active STAT3 mutant promoted cancer cell multiplication, whereas STAT3 inhibition through a dominant-negative variant impaired IL-6-driven proliferation. Blockade of STAT3 activation in CRCderived xenograft tumors slowed down their development, arguing for a contribution of STAT3 to colorectal tumor growth.

The developing cancer stem-cell model: clinical challenges and opportunities.

Science.gov (United States)

Vermeulen, Louis; de Sousa e Melo, Felipe; Richel, Dick J; Medema, Jan Paul

2012-02-01

During the past decade, a stem-cell-like subset of cancer cells has been identified in many malignancies. These cells, referred to as cancer stem cells (CSCs), are of particular interest because they are believed to be the clonogenic core of the tumour and therefore represent the cell population that drives growth and progression. Many efforts have been made to design therapies that specifically target the CSC population, since this was predicted to be the crucial population to eliminate. However, recent insights have complicated the initial elegant model, by showing a dominant role for the tumour microenvironment in determining CSC characteristics within a malignancy. This is particularly important since dedifferentiation of non-tumorigenic tumour cells towards CSCs can occur, and therefore the CSC population in a neoplasm is expected to vary over time. Moreover, evidence suggests that not all tumours are driven by rare CSCs, but might instead contain a large population of tumorigenic cells. Even though these results suggest that specific targeting of the CSC population might not be a useful therapeutic strategy, research into the hierarchical cellular organisation of malignancies has provided many important new insights in the biology of tumours. In this Personal View, we highlight how the CSC concept is developing and influences our thinking on future treatment for solid tumours, and recommend ways to design clinical trials to assess drugs that target malignant disease in a rational fashion. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dynamic model of a micro-tubular solid oxide fuel cell stack including an integrated cooling system

Science.gov (United States)

Hering, Martin; Brouwer, Jacob; Winkler, Wolfgang

2017-02-01

A novel dynamic micro-tubular solid oxide fuel cell (MT-SOFC) and stack model including an integrated cooling system is developed using a quasi three-dimensional, spatially resolved, transient thermodynamic, physical and electrochemical model that accounts for the complex geometrical relations between the cells and cooling-tubes. The modeling approach includes a simplified tubular geometry and stack design including an integrated cooling structure, detailed pressure drop and gas property calculations, the electrical and physical constraints of the stack design that determine the current, as well as control strategies for the temperature. Moreover, an advanced heat transfer balance with detailed radiative heat transfer between the cells and the integrated cooling-tubes, convective heat transfer between the gas flows and the surrounding structures and conductive heat transfer between the solid structures inside of the stack, is included. The detailed model can be used as a design basis for the novel MT-SOFC stack assembly including an integrated cooling system, as well as for the development of a dynamic system control strategy. The evaluated best-case design achieves very high electrical efficiency between around 75 and 55% in the entire power density range between 50 and 550 mW /cm2 due to the novel stack design comprising an integrated cooling structure.

Effects of serotonin on expression of the LDL receptor family member LR11 and 7-ketocholesterol-induced apoptosis in human vascular smooth muscle cells

Energy Technology Data Exchange (ETDEWEB)

Nagayama, Daiji; Ishihara, Noriko [Center of Diabetes, Endocrinology and Metabolism, Toho University, Sakura Medical Center, 564-1, Shimoshizu, Sakura-City, Chiba 285-8741 (Japan); Bujo, Hideaki [Department of Clinical Laboratory Medicine, Toho University, Sakura Medical Center, 564-1, Shimoshizu, Sakura-City, Chiba 285-8741 (Japan); Shirai, Kohji [Department of Vascular Function, Toho University, Sakura Medical Center, 564-1, Shimoshizu, Sakura-City, Chiba 285-8741 (Japan); Tatsuno, Ichiro, E-mail: ichiro.tatsuno@med.toho-u.ac.jp [Center of Diabetes, Endocrinology and Metabolism, Toho University, Sakura Medical Center, 564-1, Shimoshizu, Sakura-City, Chiba 285-8741 (Japan)

2014-04-18

Highlights: • The dedifferentiation of VSMCs in arterial intima is involved in atherosclerosis. • 5-HT showed proliferative effect on VSMCs which was abolished by sarpogrelate. • 5-HT enhanced expression of LR11 mRNA in VSMCs which was abolished by sarpogrelate. • 5-HT suppressed 7KCHO-induced apoptosis of VSMCs via caspase-3/7-dependent pathway. • The mechanisms explain the 5-HT-induced remodeling of arterial structure. - Abstract: Serotonin (5-HT) is a known mitogen for vascular smooth muscle cells (VSMCs). The dedifferentiation and proliferation/apoptosis of VSMCs in the arterial intima represent one of the atherosclerotic changes. LR11, a member of low-density lipoprotein receptor family, may contribute to the proliferation of VSMCs in neointimal hyperplasia. We conducted an in vitro study to investigate whether 5-HT is involved in LR11 expression in human VSMCs and apoptosis of VSMCs induced by 7-ketocholesterol (7KCHO), an oxysterol that destabilizes plaque. 5-HT enhanced the proliferation of VSMCs, and this effect was abolished by sarpogrelate, a selective 5-HT2A receptor antagonist. Sarpogrelate also inhibited the 5-HT-enhanced LR11 mRNA expression in VSMCs. Furthermore, 5-HT suppressed the 7KCHO-induced apoptosis of VSMCs via caspase-3/7-dependent pathway. These findings provide new insights on the changes in the differentiation stage of VSMCs mediated by 5-HT.

Development of Targeted Molecular Therapy for Cancers Harboring BAP1 Mutations

Science.gov (United States)

2016-10-01

study in cultured cells because the loss of BAP1 results in stem cell-like behavior; the cells proliferate slowly, become dedifferentiated and are...result is the inhibition of histone H2A ubiquitination and the accumulation of ubiquitin at the DNA double- strand break sites. The PRC1-mediated...immunodeficiency allows the growth of human cancer cells and cancer stem cells with significant fidelity to the original tumor. b. Actual or anticipated

Flexible organic solar cells including efficiency enhancing grating structures

International Nuclear Information System (INIS)

De Oliveira Hansen, Roana Melina; Liu Yinghui; Madsen, Morten; Rubahn, Horst-Günter

2013-01-01

In this work, a new method for the fabrication of organic solar cells containing functional light-trapping nanostructures on flexible substrates is presented. Polyimide is spin-coated on silicon support substrates, enabling standard micro- and nanotechnology fabrication techniques, such as photolithography and electron-beam lithography, besides the steps required for the bulk-heterojunction organic solar cell fabrication. After the production steps, the solar cells on polyimide are peeled off the silicon support substrates, resulting in flexible devices containing nanostructures for light absorption enhancement. Since the solar cells avoid using brittle electrodes, the performance of the flexible devices is not affected by the peeling process. We have investigated three different nanostructured grating designs and conclude that gratings with a 500 nm pitch distance have the highest light-trapping efficiency for the selected active layer material (P3HT:PCBM), resulting in an enhancement of about 34% on the solar cell efficiency. The presented method can be applied to a large variety of flexible nanostructured devices in future applications. (paper)

Flexible organic solar cells including efficiency enhancing grating structures

DEFF Research Database (Denmark)

Oliveira Hansen, Roana Melina de; Liu, Yinghui; Madsen, Morten

2013-01-01

, such as photolithography and electron-beam lithography, besides the steps required for the bulk-heterojunction organic solar cell fabrication. After the production steps, the solar cells on polyimide are peeled off the silicon support substrates, resulting in flexible devices containing nanostructures for light absorption......In this work, a new method for the fabrication of organic solar cells containing functional light-trapping nanostructures on flexible substrates is presented. Polyimide is spin-coated on silicon support substrates, enabling standard micro- and nanotechnology fabrication techniques...

RhoA activation and nuclearization marks loss of chondrocyte phenotype in crosstalk with Wnt pathway.

Science.gov (United States)

Öztürk, Ece; Despot-Slade, Evelin; Pichler, Michael; Zenobi-Wong, Marcy

2017-11-15

De-differentiation comprises a major drawback for the use of autologous chondrocytes in cartilage repair. Here, we investigate the role of RhoA and canonical Wnt signaling in chondrocyte phenotype. Chondrocyte de-differentiation is accompanied by an upregulation and nuclear localization of RhoA. Effectors of canonical Wnt signaling including β-catenin and YAP/TAZ are upregulated in de-differentiating chondrocytes in a Rho-dependent manner. Inhibition of Rho activation with C3 transferase inhibits nuclear localization of RhoA, induces expression of chondrogenic markers on 2D and enhances the chondrogenic effect of 3D culturing. Upregulation of chondrogenic markers by Rho inhibition is accompanied by loss of canonical Wnt signaling markers in 3D or on 2D whereas treatment of chondrocytes with Wnt-3a abrogates this effect. However, induction of canonical Wnt signaling inhibits chondrogenic markers on 2D but enhances chondrogenic re-differentiation on 2D with C3 transferase or in 3D. These data provide insights on the context-dependent role of RhoA and Wnt signaling in de-differentiation and on mechanisms to induce chondrogenic markers for therapeutic approaches. Copyright © 2017 Elsevier Inc. All rights reserved.

In Vivo Senescence in the Sbds-Deficient Murine Pancreas: Cell-Type Specific Consequences of Translation Insufficiency.

Directory of Open Access Journals (Sweden)

Marina E Tourlakis

2015-06-01

Full Text Available Genetic models of ribosome dysfunction show selective organ failure, highlighting a gap in our understanding of cell-type specific responses to translation insufficiency. Translation defects underlie a growing list of inherited and acquired cancer-predisposition syndromes referred to as ribosomopathies. We sought to identify molecular mechanisms underlying organ failure in a recessive ribosomopathy, with particular emphasis on the pancreas, an organ with a high and reiterative requirement for protein synthesis. Biallelic loss of function mutations in SBDS are associated with the ribosomopathy Shwachman-Diamond syndrome, which is typified by pancreatic dysfunction, bone marrow failure, skeletal abnormalities and neurological phenotypes. Targeted disruption of Sbds in the murine pancreas resulted in p53 stabilization early in the postnatal period, specifically in acinar cells. Decreased Myc expression was observed and atrophy of the adult SDS pancreas could be explained by the senescence of acinar cells, characterized by induction of Tgfβ, p15(Ink4b and components of the senescence-associated secretory program. This is the first report of senescence, a tumour suppression mechanism, in association with SDS or in response to a ribosomopathy. Genetic ablation of p53 largely resolved digestive enzyme synthesis and acinar compartment hypoplasia, but resulted in decreased cell size, a hallmark of decreased translation capacity. Moreover, p53 ablation resulted in expression of acinar dedifferentiation markers and extensive apoptosis. Our findings indicate a protective role for p53 and senescence in response to Sbds ablation in the pancreas. In contrast to the pancreas, the Tgfβ molecular signature was not detected in fetal bone marrow, liver or brain of mouse models with constitutive Sbds ablation. Nevertheless, as observed with the adult pancreas phenotype, disease phenotypes of embryonic tissues, including marked neuronal cell death due to apoptosis

In Vivo Senescence in the Sbds-Deficient Murine Pancreas: Cell-Type Specific Consequences of Translation Insufficiency

Science.gov (United States)

Tourlakis, Marina E.; Zhang, Siyi; Ball, Heather L.; Gandhi, Rikesh; Liu, Hongrui; Zhong, Jian; Yuan, Julie S.; Guidos, Cynthia J.; Durie, Peter R.; Rommens, Johanna M.

2015-01-01

Genetic models of ribosome dysfunction show selective organ failure, highlighting a gap in our understanding of cell-type specific responses to translation insufficiency. Translation defects underlie a growing list of inherited and acquired cancer-predisposition syndromes referred to as ribosomopathies. We sought to identify molecular mechanisms underlying organ failure in a recessive ribosomopathy, with particular emphasis on the pancreas, an organ with a high and reiterative requirement for protein synthesis. Biallelic loss of function mutations in SBDS are associated with the ribosomopathy Shwachman-Diamond syndrome, which is typified by pancreatic dysfunction, bone marrow failure, skeletal abnormalities and neurological phenotypes. Targeted disruption of Sbds in the murine pancreas resulted in p53 stabilization early in the postnatal period, specifically in acinar cells. Decreased Myc expression was observed and atrophy of the adult SDS pancreas could be explained by the senescence of acinar cells, characterized by induction of Tgfβ, p15Ink4b and components of the senescence-associated secretory program. This is the first report of senescence, a tumour suppression mechanism, in association with SDS or in response to a ribosomopathy. Genetic ablation of p53 largely resolved digestive enzyme synthesis and acinar compartment hypoplasia, but resulted in decreased cell size, a hallmark of decreased translation capacity. Moreover, p53 ablation resulted in expression of acinar dedifferentiation markers and extensive apoptosis. Our findings indicate a protective role for p53 and senescence in response to Sbds ablation in the pancreas. In contrast to the pancreas, the Tgfβ molecular signature was not detected in fetal bone marrow, liver or brain of mouse models with constitutive Sbds ablation. Nevertheless, as observed with the adult pancreas phenotype, disease phenotypes of embryonic tissues, including marked neuronal cell death due to apoptosis, were determined to

Aplasia versus pancytopenia, including the pure red cell variant

African Journals Online (AJOL)

to extend evaluation to the bone marrow and plasma while supplementary imaging ... B lood. Pluripotential stem cell. Early acting molecules, primarily interleukins .... options towards early immunohaematopoietic stem cell allogeneic transplantation. ... Chronic leukaemia, leukaemia, lymphomas; large granular lymphocytic ...

Hyperbaric oxygen therapy in a true regenerative environment, the regenerating limb of the axolotl

DEFF Research Database (Denmark)

Hansen, Kasper; Lauridsen, Henrik; Pedersen, Michael

2012-01-01

vertebrates such as the urodele amphibians (salamanders and newts), are excellent animal models for regenerative studies. The iconic Mexican axolotl (Ambystoma mexicanum) is capable of regenerating whole limbs, tail, jaw, and many inner organs, by dedifferentiation of cells to form a blastema (collection...

The Epithelial-to-Mesenchymal Transition in Breast Cancer: Focus on Basal-Like Carcinomas

Directory of Open Access Journals (Sweden)

Monica Fedele

2017-09-01

Full Text Available Breast cancer is a heterogeneous disease that is characterized by a high grade of cell plasticity arising from the contribution of a diverse range of factors. When combined, these factors allow a cancer cell to transition from an epithelial to a mesenchymal state through a process of dedifferentiation that confers stem-like features, including chemoresistance, as well as the capacity to migrate and invade. Understanding the complex events that lead to the acquisition of a mesenchymal phenotype will therefore help to design new therapies against metastatic breast cancer. Here, we recapitulate the main endogenous molecular signals involved in this process, and their cross-talk with paracrine factors. These signals and cross-talk include the extracellular matrix; the secretome of cancer-associated fibroblasts, macrophages, cancer stem cells, and cancer cells; and exosomes with their cargo of miRNAs. Finally, we highlight some of the more promising therapeutic perspectives based on counteracting the epithelial-to-mesenchymal transition in breast cancer cells.

Hyaluronic acid production and hyaluronidase activity in the newt iris during lens regeneration

International Nuclear Information System (INIS)

Kulyk, W.M.; Zalik, S.E.; Dimitrov, E.

1987-01-01

The process of lens regeneration in newts involves the dedifferentiation of pigmented iris epithelial cells and their subsequent conversion into lens fibers. In vivo this cell-type conversion is restricted to the dorsal region of the iris. We have examined the patterns of hyaluronate accumulation and endogenous hyaluronidase activity in the newt iris during the course of lens regeneration in vivo. Accumulation of newly synthesized hyaluronate was estimated from the uptake of [ 3 H]glucosamine into cetylpyridinium chloride-precipitable material that was sensitive to Streptomyces hyaluronidase. Endogenous hyaluronidase activity was determined from the quantity of reducing N-acetylhexosamine released upon incubation of iris tissue extract with exogenous hyaluronate substrate. We found that incorporation of label into hyaluronate was consistently higher in the regeneration-activated irises of lentectomized eyes than in control irises from sham-operated eyes. Hyaluronate labeling was higher in the dorsal (lens-forming) region of the iris than in ventral (non-lens-forming) iris tissue during the regeneration process. Label accumulation into hyaluronate was maximum between 10 and 15 days after lentectomy, the period of most pronounced dedifferentiation in the dorsal iris epithelium. Both normal and regenerating irises demonstrated a high level of endogenous hyaluronidase activity with a pH optimum of 3.5-4.0. Hyaluronidase activity was 1.7 to 2 times higher in dorsal iris tissue than in ventral irises both prior to lentectomy and throughout the regeneration process. We suggest that enhanced hyaluronate accumulation may facilitate the dedifferentiation of iris epithelial cells in the dorsal iris and prevent precocious withdrawal from the cell cycle. The high level of hyaluronidase activity in the dorsal iris may promote the turnover and remodeling of extracellular matrix components required for cell-type conversion

Integration of ATAC-seq and RNA-seq identifies human alpha cell and beta cell signature genes.

Science.gov (United States)

Ackermann, Amanda M; Wang, Zhiping; Schug, Jonathan; Naji, Ali; Kaestner, Klaus H

2016-03-01

Although glucagon-secreting α-cells and insulin-secreting β-cells have opposing functions in regulating plasma glucose levels, the two cell types share a common developmental origin and exhibit overlapping transcriptomes and epigenomes. Notably, destruction of β-cells can stimulate repopulation via transdifferentiation of α-cells, at least in mice, suggesting plasticity between these cell fates. Furthermore, dysfunction of both α- and β-cells contributes to the pathophysiology of type 1 and type 2 diabetes, and β-cell de-differentiation has been proposed to contribute to type 2 diabetes. Our objective was to delineate the molecular properties that maintain islet cell type specification yet allow for cellular plasticity. We hypothesized that correlating cell type-specific transcriptomes with an atlas of open chromatin will identify novel genes and transcriptional regulatory elements such as enhancers involved in α- and β-cell specification and plasticity. We sorted human α- and β-cells and performed the "Assay for Transposase-Accessible Chromatin with high throughput sequencing" (ATAC-seq) and mRNA-seq, followed by integrative analysis to identify cell type-selective gene regulatory regions. We identified numerous transcripts with either α-cell- or β-cell-selective expression and discovered the cell type-selective open chromatin regions that correlate with these gene activation patterns. We confirmed cell type-selective expression on the protein level for two of the top hits from our screen. The "group specific protein" (GC; or vitamin D binding protein) was restricted to α-cells, while CHODL (chondrolectin) immunoreactivity was only present in β-cells. Furthermore, α-cell- and β-cell-selective ATAC-seq peaks were identified to overlap with known binding sites for islet transcription factors, as well as with single nucleotide polymorphisms (SNPs) previously identified as risk loci for type 2 diabetes. We have determined the genetic landscape of

Chondrosarcoma: A Rare Misfortune in Aging Human Cartilage? The Role of Stem and Progenitor Cells in Proliferation, Malignant Degeneration and Therapeutic Resistance

Science.gov (United States)

Boehme, Karen A.; Schleicher, Sabine B.; Rolauffs, Bernd

2018-01-01

Unlike other malignant bone tumors including osteosarcomas and Ewing sarcomas with a peak incidence in adolescents and young adults, conventional and dedifferentiated chondrosarcomas mainly affect people in the 4th to 7th decade of life. To date, the cell type of chondrosarcoma origin is not clearly defined. However, it seems that mesenchymal stem and progenitor cells (MSPC) in the bone marrow facing a pro-proliferative as well as predominantly chondrogenic differentiation milieu, as is implicated in early stage osteoarthritis (OA) at that age, are the source of chondrosarcoma genesis. But how can MSPC become malignant? Indeed, only one person in 1,000,000 will develop a chondrosarcoma, whereas the incidence of OA is a thousandfold higher. This means a rare coincidence of factors allowing escape from senescence and apoptosis together with induction of angiogenesis and migration is needed to generate a chondrosarcoma. At early stages, chondrosarcomas are still assumed to be an intermediate type of tumor which rarely metastasizes. Unfortunately, advanced stages show a pronounced resistance both against chemo- and radiation-therapy and frequently metastasize. In this review, we elucidate signaling pathways involved in the genesis and therapeutic resistance of chondrosarcomas with a focus on MSPC compared to signaling in articular cartilage (AC). PMID:29361725

Facts about Stem Cells and Importance of Them

Directory of Open Access Journals (Sweden)

Masumeh Saeidi

2014-05-01

Full Text Available Stem cells are undifferentiated biological cells that can differentiate into specialized cells and can divide (through mitosis to produce more stem cells. They are found in multicellular organisms. In mammals, there are two broad types of stem cells: embryonic stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells, which are found in various tissues. In adult organisms, stem cells and progenitor cells act as a repair system for the body, replenishing adult tissues. In a developing embryo, stem cells can differentiate into all the specialized cells—ectoderm, endoderm and mesoderm (see induced pluripotent stem cells—but also maintain the normal turnover of regenerative organs, such as blood, skin, or intestinal tissues. There are three accessible sources of autologous adult stem cells in humans: Bone marrow, which requires extraction by harvesting, that is, drilling into bone (typically the femur or iliac crest, Adipose tissue (lipid cells, which requires extraction by liposuction, and Blood, which requires extraction through apheresis, wherein blood is drawn from the donor (similar to a blood donation, and passed through a machine that extracts the stem cells and returns other portions of the blood to the donor. Stem cells can also be taken from umbilical cord blood just after birth. Of all stem cell types, autologous harvesting involves the least risk. By definition, autologous cells are obtained from one's own body, just as one may bank his or her own blood for elective surgical procedures. Adult stem cells are frequently used in medical therapies, for example in bone marrow transplantation. Stem cells can now be artificially grown and transformed (differentiated into specialized cell types with characteristics consistent with cells of various tissues such as muscles or nerves. Embryonic cell lines and autologous embryonic stem cells generated through Somatic-cell nuclear transfer or dedifferentiation

Metamorphosis of the Drosophila visceral musculature and its role in intestinal morphogenesis and stem cell formation.

Science.gov (United States)

Aghajanian, Patrick; Takashima, Shigeo; Paul, Manash; Younossi-Hartenstein, Amelia; Hartenstein, Volker

2016-12-01

The visceral musculature of the Drosophila intestine plays important roles in digestion as well as development. Detailed studies investigating the embryonic development of the visceral muscle exist; comparatively little is known about postembryonic development and metamorphosis of this tissue. In this study we have combined the use of specific markers with electron microscopy to follow the formation of the adult visceral musculature and its involvement in gut development during metamorphosis. Unlike the adult somatic musculature, which is derived from a pool of undifferentiated myoblasts, the visceral musculature of the adult is a direct descendant of the larval fibers, as shown by activating a lineage tracing construct in the larval muscle and obtaining labeled visceral fibers in the adult. However, visceral muscles undergo a phase of remodeling that coincides with the metamorphosis of the intestinal epithelium. During the first day following puparium formation, both circular and longitudinal syncytial fibers dedifferentiate, losing their myofibrils and extracellular matrix, and dissociating into mononuclear cells ("secondary myoblasts"). Towards the end of the second day, this process is reversed, and between 48 and 72h after puparium formation, a structurally fully differentiated adult muscle layer has formed. We could not obtain evidence that cells apart from the dedifferentiated larval visceral muscle contributed to the adult muscle, nor does it appear that the number of adult fibers (or nuclei per fiber) is increased over that of the larva by proliferation. In contrast to the musculature, the intestinal epithelium is completely renewed during metamorphosis. The adult midgut epithelium rapidly expands over the larval layer during the first few hours after puparium formation; in case of the hindgut, replacement takes longer, and proceeds by the gradual caudad extension of a proliferating growth zone, the hindgut proliferation zone (HPZ). The subsequent

Upcyte® Microvascular Endothelial Cells Repopulate Decellularized Scaffold

Science.gov (United States)

Dally, Iris; Hartmann, Nadja; Münst, Bernhard; Braspenning, Joris; Walles, Heike

2013-01-01

A general problem in tissue engineering is the poor and insufficient blood supply to guarantee tissue cell survival as well as physiological tissue function. To address this limitation, we have developed an in vitro vascularization model in which a decellularized porcine small bowl segment, representing a capillary network within a collagen matrix (biological vascularized scaffold [BioVaSc]), is reseeded with microvascular endothelial cells (mvECs). However, since the supply of mvECs is limited, in general, and as these cells rapidly dedifferentiate, we have applied a novel technology, which allows the generation of large batches of quasi-primary cells with the ability to proliferate, whilst maintaining their differentiated functionality. These so called upcyte mvECs grew for an additional 15 population doublings (PDs) compared to primary cells. Upcyte mvECs retained endothelial characteristics, such as von Willebrandt Factor (vWF), CD31 and endothelial nitric oxide synthase (eNOS) expression, as well as positive Ulex europaeus agglutinin I staining. Upcyte mvECs also retained biological functionality such as tube formation, cell migration, and low density lipoprotein (LDL) uptake, which were still evident after PD27. Initial experiments using MTT and Live/Dead staining indicate that upcyte mvECs repopulate the BioVaSc Scaffold. As with conventional cultures, these cells also express key endothelial molecules (vWF, CD31, and eNOS) in a custom-made bioreactor system even after a prolonged period of 14 days. The combination of upcyte mvECs and the BioVaSc represents a novel and promising approach toward vascularizing bioreactor models which can better reflect organs, such as the liver. PMID:22799502

In vitro identification and characterization of CD133(pos cancer stem-like cells in anaplastic thyroid carcinoma cell lines.

Directory of Open Access Journals (Sweden)

Giovanni Zito

Full Text Available Recent publications suggest that neoplastic initiation and growth are dependent on a small subset of cells, termed cancer stem cells (CSCs. Anaplastic Thyroid Carcinoma (ATC is a very aggressive solid tumor with poor prognosis, characterized by high dedifferentiation. The existence of CSCs might account for the heterogeneity of ATC lesions. CD133 has been identified as a stem cell marker for normal and cancerous tissues, although its biological function remains unknown.ATC cell lines ARO, KAT-4, KAT-18 and FRO were analyzed for CD133 expression. Flow cytometry showed CD133(pos cells only in ARO and KAT-4 (64+/-9% and 57+/-12%, respectively. These data were confirmed by qRT-PCR and immunocytochemistry. ARO and KAT-4 were also positive for fetal marker oncofetal fibronectin and negative for thyrocyte-specific differentiating markers thyroglobulin, thyroperoxidase and sodium/iodide symporter. Sorted ARO/CD133(pos cells exhibited higher proliferation, self-renewal, colony-forming ability in comparison with ARO/CD133(neg. Furthermore, ARO/CD133(pos showed levels of thyroid transcription factor TTF-1 similar to the fetal thyroid cell line TAD-2, while the expression in ARO/CD133(neg was negligible. The expression of the stem cell marker OCT-4 detected by RT-PCR and flow cytometry was markedly higher in ARO/CD133(pos in comparison to ARO/CD133(neg cells. The stem cell markers c-KIT and THY-1 were negative. Sensitivity to chemotherapy agents was investigated, showing remarkable resistance to chemotherapy-induced apoptosis in ARO/CD133(pos when compared with ARO/CD133(neg cells.We describe CD133(pos cells in ATC cell lines. ARO/CD133(pos cells exhibit stem cell-like features--such as high proliferation, self-renewal ability, expression of OCT-4--and are characterized by higher resistance to chemotherapy. The simultaneous positivity for thyroid specific factor TTF-1 and onfFN suggest they might represent putative thyroid cancer stem-like cells. Our in

p-Glycoprotein ABCB5 and YB-1 expression plays a role in increased heterogeneity of breast cancer cells: correlations with cell fusion and doxorubicin resistance

International Nuclear Information System (INIS)

Yang, Ji Yeon; Ha, Seon-Ah; Yang, Yun-Sik; Kim, Jin Woo

2010-01-01

Cancer cells recurrently develop into acquired resistance to the administered drugs. The iatrogenic mechanisms of induced chemotherapy-resistance remain elusive and the degree of drug resistance did not exclusively correlate with reductions of drug accumulation, suggesting that drug resistance may involve additional mechanisms. Our aim is to define the potential targets, that makes drug-sensitive MCF-7 breast cancer cells turn to drug-resistant, for the anti-cancer drug development against drug resistant breast cancer cells. Doxorubicin resistant human breast MCF-7 clones were generated. The doxorubicin-induced cell fusion events were examined. Heterokaryons were identified and sorted by FACS. In the development of doxorubicin resistance, cell-fusion associated genes, from the previous results of microarray, were verified using dot blot array and quantitative RT-PCR. The doxorubicin-induced expression patterns of pro-survival and pro-apoptotic genes were validated. YB-1 and ABCB5 were up regulated in the doxorubicin treated MCF-7 cells that resulted in certain degree of genomic instability that accompanied by the drug resistance phenotype. Cell fusion increased diversity within the cell population and doxorubicin resistant MCF-7 cells emerged probably through clonal selection. Most of the drug resistant hybrid cells were anchorage independent. But some of the anchorage dependent MCF-7 cells exhibited several unique morphological appearances suggesting minor population of the fused cells maybe de-differentiated and have progenitor cell like characteristics. Our work provides valuable insight into the drug induced cell fusion event and outcome, and suggests YB-1, GST, ABCB5 and ERK3 could be potential targets for the anti-cancer drug development against drug resistant breast cancer cells. Especially, the ERK-3 serine/threonine kinase is specifically up-regulated in the resistant cells and known to be susceptible to synthetic antagonists

Advances in the theory and application of BSF cells. [including electrical resistivity and photovoltaic cells

Science.gov (United States)

Mandelkorn, J.; Lamneck, J. H.

1975-01-01

The characteristics and behavior of p(+), p solar cells were investigated. The p(+), p cells were made by the removal of the n(+) surface layers from n(+), p p(+), BSF cells followed by application of a suitable contact to the resultant p(+), p structures. The open circuit voltage of p(+), p cells was found to increase with increasing 'p' bulk resistivity. The measured open circuit velocity-temperature coefficients were positive and increased with increasing resistivity. An outline of prior limitations in solar cell design is presented, and the removal of these limitations through use of BSF effects is pointed out. The study of BSF effects made feasible production of very thin high efficiency silicon cells as well as high resistivity-high efficiency cells, two desirable types of silicon cells which were previously impossible to make.

Chondrocyte behavior on nanostructured micropillar polypropylene and polystyrene surfaces

Energy Technology Data Exchange (ETDEWEB)

Prittinen, Juha [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland); Jiang, Yu [Department of Chemistry, University of Eastern Finland, Joensuu (Finland); Ylärinne, Janne H. [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland); Pakkanen, Tapani A. [Department of Chemistry, University of Eastern Finland, Joensuu (Finland); Lammi, Mikko J., E-mail: mikko.lammi@uef.fi [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland); Qu, Chengjuan [Department of Applied Physics, University of Eastern Finland, Kuopio (Finland)

2014-10-01

This study was aimed to investigate whether patterned polypropylene (PP) or polystyrene (PS) could enhance the chondrocytes' extracellular matrix (ECM) production and phenotype maintenance. Bovine primary chondrocytes were cultured on smooth PP and PS, as well as on nanostructured micropillar PP (patterned PP) and PS (patterned PS) for 2 weeks. Subsequently, the samples were collected for fluorescein diacetate-based cell viability tests, for immunocytochemical assays of types I and II collagen, actin and vinculin, for scanning electronic microscopic analysis of cell morphology and distribution, and for gene expression assays of Sox9, aggrecan, procollagen α{sub 1}(II), procollagen α{sub 1}(X), and procollagen α{sub 2}(I) using quantitative RT-PCR assays. After two weeks of culture, the bovine primary chondrocytes had attached on both patterned PP and PS, while practically no adhesion was observed on smooth PP. However, the best adhesion of the cells was on smooth PS. The cells, which attached on patterned PP and PS surfaces synthesized types I and II collagen. The chondrocytes' morphology was extended, and an abundant ECM network formed around the attached chondrocytes on both patterned PP and PS. Upon passaging, no significant differences on the chondrocyte-specific gene expression were observed, although the highest expression level of aggrecan was observed on the patterned PS in passage 1 chondrocytes, and the expression level of procollagen α{sub 1}(II) appeared to decrease in passaged chondrocytes. However, the expressions of procollagen α{sub 2}(I) were increased in all passaged cell cultures. In conclusion, the bovine primary chondrocytes could be grown on patterned PS and PP surfaces, and they produced extracellular matrix network around the adhered cells. However, neither the patterned PS nor PP could prevent the dedifferentiation of chondrocytes. - Highlights: • Methods to avoid chondrocyte dedifferentiation would be useful for cartilage

The primary immune response to Vaccinia virus vaccination includes cells with a distinct cytotoxic effector CD4 T-cell phenotype.

Science.gov (United States)

Munier, C Mee Ling; van Bockel, David; Bailey, Michelle; Ip, Susanna; Xu, Yin; Alcantara, Sheilajen; Liu, Sue Min; Denyer, Gareth; Kaplan, Warren; Suzuki, Kazuo; Croft, Nathan; Purcell, Anthony; Tscharke, David; Cooper, David A; Kent, Stephen J; Zaunders, John J; Kelleher, Anthony D

2016-10-17

Smallpox was eradicated by a global program of inoculation with Vaccinia virus (VV). Robust VV-specific CD4 T-cell responses during primary infection are likely essential to controlling VV replication. Although there is increasing interest in cytolytic CD4 T-cells across many viral infections, the importance of these cells during acute VV infection is unclear. We undertook a detailed functional and genetic characterization of CD4 T-cells during acute VV-infection of humans. VV-specific T-cells were identified by up-regulation of activation markers directly ex vivo and through cytokine and co-stimulatory molecule expression. At day-13-post primary inoculation with VV, CD38highCD45RO+ CD4 T-cells were purified by cell sorting, RNA isolated and analysed by microarray. Differential expression of up-regulated genes in activated CD4 T-cells was confirmed at the mRNA and protein levels. We compared analyses of VV-specific CD4 T-cells to studies on 12 subjects with primary HIV infection (PHI). VV-specific T-cells lines were established from PBMCs collected post vaccination and checked for cytotoxicity potential. A median 11.9% CD4 T-cells were CD38highCD45RO+ at day-13 post-VV inoculation, compared to 3.0% prior and 10.4% during PHI. Activated CD4 T-cells had an up-regulation of genes related to cytolytic function, including granzymes K and A, perforin, granulysin, TIA-1, and Rab27a. No difference was seen between CD4 T-cell expression of perforin or TIA-1 to VV and PHI, however granzyme k was more dominant in the VV response. At 25:1 effector to target ratio, two VV-specific T-cell lines exhibited 62% and 30% cytotoxicity respectively and CD107a degranulation. We show for the first time that CD4 CTL are prominent in the early response to VV. Understanding the role of CD4 CTL in the generation of an effective anti-viral memory may help develop more effective vaccines for diseases such as HIV. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

High Throughput Micro-Well Generation of Hepatocyte Micro-Aggregates for Tissue Engineering

NARCIS (Netherlands)

Gevaert, Elien; Dollé, Laurent; Billiet, Thomas; Dubruel, Peter; van Grunsven, Leo; van Apeldoorn, Aart A.; Cornelissen, Ria

2014-01-01

The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the

Analysis of the expression and function of Wnt-5a and Wnt-5b in developing and regenerating axolotl (Ambystoma mexicanum) limbs.

Science.gov (United States)

Ghosh, Sukla; Roy, Stéphane; Séguin, Carl; Bryant, Susan V; Gardiner, David M

2008-05-01

Urodele amphibians are unique adult vertebrates because they are able to regenerate body parts after amputation. Studies of urodele limb regeneration, the key model system for vertebrate regeneration, have led to an understanding of the origin of blastema cells and the importance of positional interactions between blastema cells in the control of growth and pattern formation. Progress is now being made in the identification of the signaling pathways that regulate dedifferentiation, blastema morphogenesis, growth and pattern formation. Members of the Wnt family of secreted proteins are expressed in developing and regenerating limbs, and have the potential to control growth, pattern formation and differentiation. We have studied the expression of two non-canonical Wnt genes, Wnt-5a and Wnt-5b. We report that they are expressed in equivalent patterns during limb development and limb regeneration in the axolotl (Ambystoma mexicanum), and during limb development in other tetrapods, implying conservation of function. Our analysis of the effects of ectopic Wnt-5a expression is consistent with the hypothesis that canonical Wnt signaling functions during the early stages of regeneration to control the dedifferentiation of stump cells giving rise to the regeneration-competent cells of the blastema.

Induced Retro-Differentiation of Human Retinal Pigment Epithelial Cells on PolyHEMA.

Science.gov (United States)

Nazemroaya, Fatemeh; Soheili, Zahra-Soheila; Samiei, Shahram; Deezagi, Abdolkhalegh; Ahmadieh, Hamid; Davari, Malihe; Heidari, Razeih; Bagheri, Abouzar; Darvishalipour-Astaneh, Shamila

2017-10-01

Retinal pigment epithelium (RPE) cells represent a great potential to rescue degenerated cells of the damaged retina. Activation of the virtually plastic properties of RPE cells may aid in recovery of retinal degenerative disorders without the need for entire RPE sheet transplantation. Poly (2-hydroxyethyl methacrylate)(PolyHEMA) is one of the most important hydrogels in the biomaterials world. This hydrophobic polymer does not normally support attachment of mammalian cells. In the current study we investigated the effect of PolyHEMA as a cell culture substrate on the growth, differentiation, and plasticity of hRPE cells. hRPE cells were isolated from neonatal human globes and cultured on PolyHEMA and polystyrene substrates (as controls) in 24-well culture plates. DMEM/F12 was supplemented with 10% fetal bovine serum (FBS) and/or 30% human amniotic fluid (HAF) for cultured cells on polystyrene and PolyHEMA coated vessels. Morphology, rate of cell proliferation and cell death, MTT assay, immunocytochemistry and Real-Time RT-PCR were performed to investigate the effects of PolyHEMA on the growth and differentiation of cultured hRPE cells. Proliferation rate of the cells that had been cultured on PolyHEMA was reduced; PolyHEMA did not induce cell death in the hRPE cultures. hRPE cells cultured on PolyHEMA formed many giant spheroid colonies. The giant colonies were re-cultured and the presence of retinal progenitor markers and markers of hRPE cells were detected in cell cultures on PolyHEMA. PolyHEMA seems to be promising for both maintenance and de-differentiation of hRPE cells and expansion of the retinal progenitor cells from the cultures that are originated from hRPE cells. J. Cell. Biochem. 118: 3080-3089, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

SOX17 Regulates Cholangiocyte Differentiation and Acts as a Tumor Suppressor in Cholangiocarcinoma

DEFF Research Database (Denmark)

Merino-Azpitarte, M; Lozano, E; Perugorria, M J

2017-01-01

/function was evaluated along the differentiation of human induced pluripotent stem cells (iPSC) into cholangiocytes, in the dedifferentiation process of normal human cholangiocytes (NHC) in culture and in cholangiocarcinogenesis. Lentiviruses for SOX17 overexpression or knock-down were used. Gene expression and DNA......BACKGROUND & AIMS: Cholangiocarcinoma (CCA) is a biliary malignancy linked to genetic and epigenetic abnormalities, such as hypermethylation of SOX17 promoter. Here, the role of SOX17 in cholangiocyte differentiation and cholangiocarcinogenesis was studied. METHODS: SOX17 expression...... methylation profiling were performed. RESULTS: SOX17 expression is induced in the last stage of cholangiocyte differentiation from iPSC and regulates the acquisition of biliary markers. SOX17 becomes downregulated in NHC undergoing dedifferentiation; experimental SOX17 knock-down in differentiated NHC...

Photovoltaic cell electrical heating system for removing snow on panel including verification.

Science.gov (United States)

Weiss, Agnes; Weiss, Helmut

2017-11-16

Small photovoltaic plants in private ownership are typically rated at 5 kW (peak). The panels are mounted on roofs at a decline angle of 20° to 45°. In winter time, a dense layer of snow at a width of e.g., 10 cm keeps off solar radiation from the photovoltaic cells for weeks under continental climate conditions. Practically, no energy is produced over the time of snow coverage. Only until outside air temperature has risen high enough for a rather long-time interval to allow partial melting of snow; the snow layer rushes down in an avalanche. Following this proposal, snow removal can be arranged electrically at an extremely positive energy balance in a fast way. A photovoltaic cell is a large junction area diode inside with a threshold voltage of about 0.6 to 0.7 V (depending on temperature). This forward voltage drop created by an externally driven current through the modules can be efficiently used to provide well-distributed heat dissipation at the cell and further on at the glass surface of the whole panel. The adhesion of snow on glass is widely reduced through this heating in case a thin water film can be produced by this external short time heating. Laboratory experiments provided a temperature increase through rated panel current of more than 10 °C within about 10 min. This heating can initiate the avalanche for snow removal on intention as described before provided the clamping effect on snow at the edge of the panel frame is overcome by an additional heating foil. Basics of internal cell heat production, heating thermal effects in time course, thermographic measurements on temperature distribution, power circuit opportunities including battery storage elements and snow-removal under practical conditions are described.

Targeting TBP-associated factors in ovarian cancer

Directory of Open Access Journals (Sweden)

Jennifer R Ribeiro

2014-03-01

Full Text Available As ovarian tumors progress, they undergo a process of dedifferentiation, allowing adaptive changes in growth and morphology that promote metastasis and chemoresistance. Herein, we outline a hypothesis that TATA-box binding protein (TBP associated factors (TAFs, which compose the RNA Polymerase II initiation factor, TFIID, contribute to regulation of dedifferentiation states in ovarian cancer. Numerous studies demonstrate that TAFs regulate differentiation and proliferation states; their expression is typically high in pluripotent cells and reduced upon differentiation. Strikingly, TAF2 exhibits copy number increases or mRNA overexpression in 73% of high grade serous ovarian cancers (HGSC. At the biochemical level, TAF2 directs TFIID to TATA-less promoters by contact with an Initiator element, which may lead to the deregulation of the transcriptional output of these tumor cells. TAF4, which is altered in 66% of HGSC, is crucial for the stability of the TFIID complex and helps drive dedifferentiation of mouse embryonic fibroblasts to induced pluripotent stem cells. Its ovary-enriched paralog, TAF4B, is altered in 26% of HGSC. Here, we show that Taf4b mRNA correlates with Cyclin D2 mRNA expression in human granulosa cell tumors. TAF4B may also contribute to regulation of tumor microenvironment due to its estrogen-responsiveness and ability to act as a cofactor for NFκB. Conversely, TAF9, a cofactor for p53 in regulating apoptosis, may act as a tumor suppressor in ovarian cancer, since it is downregulated or deleted in 98% of HGSC. We conclude that a greater understanding of mechanisms of transcriptional regulation that execute signals from oncogenic signaling cascades is needed in order to expand our understanding of the etiology and progression of ovarian cancer, and most importantly to identify novel targets for therapeutic intervention.

BMPR2 inhibition induced apoptosis and autophagy via destabilization of XIAP in human chondrosarcoma cells

Science.gov (United States)

Jiao, G; Guo, W; Ren, T; Lu, Q; Sun, Y; Liang, W; Ren, C; Yang, K; Sun, K

2014-01-01

Bone morphogenetic proteins (BMPs) are multifunctional proteins, and their receptors (BMPRs) have crucial roles in the process of signaling. However, their function in cancer is somewhat inconsistent. It has been demonstrated that more prevalent expression of bone morphogenetic protein receptor 2 (BMPR2) has been detected in dedifferentiated chondrosarcomas than conventional chondrosarcomas. Here, we find that BMPR2 inhibition induces apoptosis and autophagy of chondrosarcoma. We found that BMPR2 expression was correlated with the clinicopathological features of chondrosarcomas, and could predict the treatment outcome. Knockdown of BMPR2 by small interfering RNA results in growth inhibition in chondrosarcoma cells. Silencing BMPR2 promoted G2/M cell cycle arrest, induced chondrosarcoma cell apoptosis through caspase-3-dependent pathway via repression of X-linked inhibitor of apoptosis protein (XIAP) and induced autophagy of chondrosarcoma cells via XIAP-Mdm2-p53 pathway. Inhibition of autophagy induced by BMPR2 small interfering RNA (siBMPR2) sensitized chondrosarcoma cells to siBMPR2-induced apoptotic cell death, suggesting that autophagy has a protective role for chondrosarcoma cells in context of siBMPR2-induced apoptotic cell death. In vivo tumorigenicity assay in mice indicated that inhibition of BMPR2 reduced tumor growth. Taken together, our results suggest that BMPR2 has a significant role in the tumorigenesis of chondrosarcoma, and could be an important prognostic marker for chondrosarcoma. BMPR2 inhibition could eventually provide a promising therapy for chondrosarcoma treatment. PMID:25501832

HLA-DRB1*16-restricted recognition of myeloid cells, including CD34+ CML progenitor cells

NARCIS (Netherlands)

Ebeling, Saskia B.; Ivanov, Roman; Hol, Samantha; Aarts, Tineke I.; Hagenbeek, Anton; Verdonck, Leo F.; Petersen, Eefke J.

2003-01-01

The therapeutic effect of a human leucocyte antigen (HLA)-identical allogeneic stem cell transplantation (allo-SCT) for the treatment of haematological malignancies is mediated partly by the allogeneic T cells that are administered together with the stem cell graft. Chronic myeloid leukaemia (CML)

Activation of Sox3 Gene by Thyroid Hormone in the Developing Adult Intestinal Stem Cell During Xenopus Metamorphosis

Science.gov (United States)

Sun, Guihong; Fu, Liezhen; Wen, Luan

2014-01-01

The maturation of the intestine into the adult form involves the formation of adult stem cells in a thyroid hormone (T3)-dependent process in vertebrates. In mammals, this takes place during postembryonic development, a period around birth when the T3 level peaks. Due to the difficulty of manipulating late-stage, uterus-enclosed embryos, very little is known about the development of the adult intestinal stem cells. Interestingly, the remodeling of the intestine during the T3-dependent amphibian metamorphosis mimics the maturation of mammalian intestine. Our earlier microarray studies in Xenopus laevis revealed that the transcription factor SRY (sex-determining region Y)-box 3 (Sox3), well known for its involvement in neural development, was upregulated in the intestinal epithelium during metamorphosis. Here, we show that Sox3 is highly and specifically expressed in the developing adult intestinal progenitor/stem cells. We further show that its induction by T3 is independent of new protein synthesis, suggesting that Sox3 is directly activated by liganded T3 receptor. Thus, T3 activates Sox3 as one of the earliest changes in the epithelium, and Sox3 in turn may facilitate the dedifferentiation of the larval epithelial cells into adult stem cells. PMID:25211587

Plasma Cell Neoplasms (Including Multiple Myeloma) Treatment (PDQ®)—Patient Version

Science.gov (United States)

Plasma cell neoplasms occur when abnormal plasma cells or myeloma cells form tumors in the bones or soft tissues of the body. Multiple myeloma, plasmacytoma, lymphoplasmacytic lymphoma, and monoclonal gammopathy of undetermined significance (MGUS) are different types of plasma cell neoplasms. Find out about risk factors, symptoms, diagnostic tests, prognosis, and treatment for these diseases.

Long-term effect on in vitro cloning efficiency after treatment of somatic cells with Xenopus egg extract in the pig.

Science.gov (United States)

Liu, Ying; Ostrup, Olga; Li, Rong; Li, Juan; Vajta, Gábor; Kragh, Peter M; Schmidt, Mette; Purup, Stig; Hyttel, Poul; Klærke, Dan; Callesen, Henrik

2014-08-01

In somatic cell nuclear transfer (SCNT), donor cell reprogramming is considered as a biologically important and vulnerable event. Various donor cell pre-treatments with Xenopus egg extracts can promote reprogramming. Here we investigated if the reprogramming effect of one treatment with Xenopus egg extract on donor cells was maintained for several cell passages. The extract treatment resulted in increased cell-colony formation from early passages in treated porcine fibroblasts (ExTES), and increased development of cloned embryos. Partial dedifferentiation was observed in ExTES cells, shown as a tendency towards upregulation of NANOG, c-MYC and KLF-4 and downregulation of DESMIM compared with ExTES at Passage 2. Compared with our routine SCNT, continuously increased development of cloned embryos was observed in the ExTES group, and ExTES cloned blastocysts displayed hypermethylated DNA patterns and hypermethylation of H3K4me3 and H3K27me3 in ICM compared with TE. All seven recipients became pregnant after transferral of ExTES cloned embryos and gave birth to 7-22 piglets per litter (average 12). In conclusion, our results demonstrate that one treatment of porcine fibroblasts with Xenopus egg extract can result in long-term increased ability of the cells to promote their in vitro function in subsequent SCNT. Finally these cells can also result in successful development of cloned embryos to term.

Cellular Components, Including Stem-Like Cells, of Preterm Mother's Mature Milk as Compared with Those in Her Colostrum: A Pilot Study.

Science.gov (United States)

Kaingade, Pankaj; Somasundaram, Indumathi; Sharma, Akshita; Patel, Darshan; Marappagounder, Dhanasekaran

2017-09-01

Whether the preterm mothers' mature milk retains the same cellular components as those in colostrum including stem-like cell, cell adhesion molecules, and immune cells. A total of five preterm mothers were recruited for the study having an average age of 30.2 years and gestational age of 29.8 weeks from the Pristine Women's Hospital, Kolhapur. Colostrum milk was collected within 2-5 days and matured milk was collected 20-30 days after delivery from the same mothers. Integral cellular components of 22 markers including stem cells, immune cells, and cell adhesion molecules were measured using flowcytometry. Preterm mature milk was found to possess higher expressions of hematopoietic stem cells, mesenchymal stem-like cells, immune cells, few cell adhesion molecules, and side population cells than colostrum. The increased level of these different cell components in mature milk may be important in the long-term preterm baby's health growth. Further similar research in a larger population of various gestational ages and lactation stages of preterm mothers is warranted to support these pilot findings.

Simulation of E. coli gene regulation including overlapping cell cycles, growth, division, time delays and noise.

Directory of Open Access Journals (Sweden)

Ruoyu Luo

Full Text Available Due to the complexity of biological systems, simulation of biological networks is necessary but sometimes complicated. The classic stochastic simulation algorithm (SSA by Gillespie and its modified versions are widely used to simulate the stochastic dynamics of biochemical reaction systems. However, it has remained a challenge to implement accurate and efficient simulation algorithms for general reaction schemes in growing cells. Here, we present a modeling and simulation tool, called 'GeneCircuits', which is specifically developed to simulate gene-regulation in exponentially growing bacterial cells (such as E. coli with overlapping cell cycles. Our tool integrates three specific features of these cells that are not generally included in SSA tools: 1 the time delay between the regulation and synthesis of proteins that is due to transcription and translation processes; 2 cell cycle-dependent periodic changes of gene dosage; and 3 variations in the propensities of chemical reactions that have time-dependent reaction rates as a consequence of volume expansion and cell division. We give three biologically relevant examples to illustrate the use of our simulation tool in quantitative studies of systems biology and synthetic biology.

Lithium Impairs Kidney Development and Inhibits Glycogen Synthase Kinase-3β in Collecting Duct Principal Cells

DEFF Research Database (Denmark)

Kjærsgaard, Gitte; Madsen, Kirsten; Marcussen, Niels

level significantly whereas total GSK-3β abundance was unaltered. Li+ treatment increased α-Smooth Muscle Actin (α-SMA) protein level significantly whereas E-cadherin expression was unaltered. In summary, Li+ treatment impairs postnatal development of the kidney cortex and outer medulla and increases pGSK......The postnatal rat kidney is highly susceptible to Lithium (Li+), which leads to significant tissue injury. We hypothesized that Li+ impairs development of the kidney through entry into epithelial cells of the distal nephron, inhibition of Glycogen Synthase Kinase-3β (GSK-3β) through phosphorylation...... on serine9 (pGSK-3β)and subsequent epithelial to mesenchymal dedifferentiation (EMT). GSK-3β immunoreactive protein was associated with collecting ducts in developing and adult human and rat kidney. Total GSK-3β protein abundance was stable in medulla while it decreased in cortex in the postnatal period...

Radiosensitization effect by combination with paclitaxel in vivo, including the effect on intratumor quiescent cells

International Nuclear Information System (INIS)

Masunaga, Shin-ichiro; Ono, Koji; Suzuki, Minoru; Nishimura, Yasumasa; Kinashi, Yuko; Takagaki, Masao; Hori, Hitoshi; Nagasawa, Hideko; Uto, Yoshihiro; Tsuchiya, Izumi; Sadahiro, Sotaro; Murayama, Chieko

2001-01-01

Purpose: To evaluate the radiosensitization effect on solid tumors upon combination treatment with paclitaxel (TXL), including the effect on intratumor quiescent (Q) cells. Methods and Materials: Mice bearing SCC VII or EL4 solid tumors received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days to label all proliferating (P) cells. The mice then received γ-irradiation with or without tirapazamine (TPZ) at various time points after TXL administration. Another group of mice received a series of test doses of γ-rays while alive or after tumor clamping to obtain hypoxic fractions (HFs) in the tumors at various time points after TXL administration. Immediately after irradiation, the tumor cells were isolated and incubated with a cytokinesis blocker. The micronucleus (MN) frequency in cells without BrdU labeling (Q cells) was determined using immunofluorescence staining for BrdU. Meanwhile, 6 h after irradiation, the tumor cells were isolated from the solid tumors in another group of mice, and the apoptosis frequency in Q cells was also determined with immunofluorescence staining for BrdU. The MN and apoptosis frequency in total (P+Q) tumor cells were determined from the tumors that were not pretreated with BrdU. For the measurement of the HFs, the MN or apoptosis frequency of Q cells was then used to calculate the surviving fraction of Q cells from the regression line for the relationship between the MN or apoptosis frequency and the surviving fraction of total tumor cells. Results: In both SCC VII and EL4 tumors, maximum values of mitotic index (MI) and apoptosis frequency were observed 9 and 24 h after TXL administration, respectively. However, on the whole, the apoptosis frequency for SCC VII was very low. γ-Irradiation 9 h after TXL administration induced significant radiosensitization effects on the total cells of both tumors. Irradiation at 60 h had a more significant effect on total cells of EL4 tumor, but no significant effect on total cells of SCC VII

Canine ovarian neoplasms: a clinicopathologic study of 71 cases, including histology of 12 granulosa cell tumors.

Science.gov (United States)

Patnaik, A K; Greenlee, P G

1987-11-01

In a retrospective study of 71 primary ovarian tumors in the dog, epithelial tumors (46%) were more common than sex cord stromal (34%) and germ cell tumors (20%). There were more adenocarcinomas (64%) than adenomas. Sex cord stromal tumors were equally divided into Sertoli-Leydig (12/24) and granulosa cell tumors (12/24). There were equal numbers (7/14) of dysgerminomas and teratomas among the germ cell tumors. Most teratomas (6/7) were malignant. Most granulosa cell tumors were solid; two were mostly cystic. Patterns included sheets of round and ovoid to spindle-shaped cells separated by thin, fibrovascular stroma; neoplastic cells formed rosettes or Call-Exner bodies. In some areas, neoplastic cells were in cords or columns and formed cyst-like structures. Four granulosa cell tumors were macrofollicular, having cysts lined with granulosa cells. Median ages of dogs with different ovarian neoplasms were similar; all were more than 10 years old, except the dogs with teratoma (mean age, 4 years). Most neoplasms were unilateral (84%), except the Sertoli-Leydig cell tumors, many of which were bilateral (36%). Size of ovarian neoplasms varied (2 cm3 to 15,000 cm3). Twenty-nine percent of neoplasms metastasized; adenocarcinomas (48%) and malignant teratomas (50%) had the highest rates, and distant metastasis was more common in malignant teratoma. Endometrial hyperplasia was in 67% of the dogs; it was most common in dogs with sex cord stromal tumors (95%). Uterine malignancy was not seen in dogs with granulosa cell tumors, although hyperplasia endometrium was in all dogs with this tumor. Cysts in the contralateral ovaries were most common in dogs with sex cord stromal tumors.

Articular cartilage-derived cells hold a strong osteogenic differentiation potential in comparison to mesenchymal stem cells in vitro

International Nuclear Information System (INIS)

Salamon, Achim; Jonitz-Heincke, Anika; Adam, Stefanie; Rychly, Joachim; Müller-Hilke, Brigitte; Bader, Rainer; Lochner, Katrin; Peters, Kirsten

2013-01-01

Cartilaginous matrix-degenerative diseases like osteoarthritis (OA) are characterized by gradual cartilage erosion, and also by increased presence of cells with mesenchymal stem cell (MSC) character within the affected tissues. Moreover, primary chondrocytes long since are known to de-differentiate in vitro and to be chondrogenically re-differentiable. Since both findings appear to conflict with each other, we quantitatively assessed the mesenchymal differentiation potential of OA patient cartilage-derived cells (CDC) towards the osteogenic and adipogenic lineage in vitro and compared it to that of MSC isolated from adipose tissue (adMSC) of healthy donors. We analyzed expression of MSC markers CD29, CD44, CD105, and CD166, and, following osteogenic and adipogenic induction in vitro, quantified their expression of osteogenic and adipogenic differentiation markers. Furthermore, CDC phenotype and proliferation were monitored. We found that CDC exhibit an MSC CD marker expression pattern similar to adMSC and a similar increase in proliferation rate during osteogenic differentiation. In contrast, the marked reduction of proliferation observed during adipogenic differentiation of adMSC was absent in CDC. Quantification of differentiation markers revealed a strong osteogenic differentiation potential for CDC, however almost no capacity for adipogenic differentiation. Since in the pathogenesis of OA, cartilage degeneration coincides with high bone turnover rates, the high osteogenic differentiation potential of OA patient-derived CDC may affect clinical therapeutic regimens aiming at autologous cartilage regeneration in these patients. - Highlights: • We analyze the mesenchymal differentiation capacity of cartilage-derived cells (CDC). • CDC express mesenchymal stem cell (MSC) markers CD29, CD44, CD105, and CD166. • CDC and MSC proliferation is reduced in adipogenesis and increased in osteogenesis. • Adipogenic differentiation is virtually absent in CDC, but

Articular cartilage-derived cells hold a strong osteogenic differentiation potential in comparison to mesenchymal stem cells in vitro

Energy Technology Data Exchange (ETDEWEB)

Salamon, Achim, E-mail: achim.salamon@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Jonitz-Heincke, Anika, E-mail: anika.jonitz@med.uni-rostock.de [Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Doberaner Straße 142, D-18057 Rostock (Germany); Adam, Stefanie, E-mail: stefanie.adam@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Rychly, Joachim, E-mail: joachim.rychly@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany); Müller-Hilke, Brigitte, E-mail: brigitte.mueller-hilke@med.uni-rostock.de [Institute of Immunology, Rostock University Medical Center, Schillingallee 68, D-18057 Rostock (Germany); Bader, Rainer, E-mail: rainer.bader@med.uni-rostock.de [Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Doberaner Straße 142, D-18057 Rostock (Germany); Lochner, Katrin, E-mail: katrin.lochner@med.uni-rostock.de [Biomechanics and Implant Technology Research Laboratory, Department of Orthopedics, Rostock University Medical Center, Doberaner Straße 142, D-18057 Rostock (Germany); Peters, Kirsten, E-mail: kirsten.peters@med.uni-rostock.de [Department of Cell Biology, Rostock University Medical Center, Schillingallee 69, D-18057 Rostock (Germany)

2013-11-01

Cartilaginous matrix-degenerative diseases like osteoarthritis (OA) are characterized by gradual cartilage erosion, and also by increased presence of cells with mesenchymal stem cell (MSC) character within the affected tissues. Moreover, primary chondrocytes long since are known to de-differentiate in vitro and to be chondrogenically re-differentiable. Since both findings appear to conflict with each other, we quantitatively assessed the mesenchymal differentiation potential of OA patient cartilage-derived cells (CDC) towards the osteogenic and adipogenic lineage in vitro and compared it to that of MSC isolated from adipose tissue (adMSC) of healthy donors. We analyzed expression of MSC markers CD29, CD44, CD105, and CD166, and, following osteogenic and adipogenic induction in vitro, quantified their expression of osteogenic and adipogenic differentiation markers. Furthermore, CDC phenotype and proliferation were monitored. We found that CDC exhibit an MSC CD marker expression pattern similar to adMSC and a similar increase in proliferation rate during osteogenic differentiation. In contrast, the marked reduction of proliferation observed during adipogenic differentiation of adMSC was absent in CDC. Quantification of differentiation markers revealed a strong osteogenic differentiation potential for CDC, however almost no capacity for adipogenic differentiation. Since in the pathogenesis of OA, cartilage degeneration coincides with high bone turnover rates, the high osteogenic differentiation potential of OA patient-derived CDC may affect clinical therapeutic regimens aiming at autologous cartilage regeneration in these patients. - Highlights: • We analyze the mesenchymal differentiation capacity of cartilage-derived cells (CDC). • CDC express mesenchymal stem cell (MSC) markers CD29, CD44, CD105, and CD166. • CDC and MSC proliferation is reduced in adipogenesis and increased in osteogenesis. • Adipogenic differentiation is virtually absent in CDC, but

Regulation of Regenerative Responses by Factors in the Extracellular Matrix during Axolotl (Ambystoma mexicanum) Limb Regeneration

OpenAIRE

Phan, Anne Quy

2014-01-01

Salamanders are unique among adult vertebrates in their ability to regenerate complex body structures after traumatic injury. Axolotl limb regeneration is a stepwise sequence of three requisite processes: (1) scarless wound healing to generate a regenerative wound epithelium, (2) blastema formation by migration, proliferation and dedifferentiation to create a mass of multipotent regeneration-competent progenitor cells, and (3) induction of pattern formation by interaction of cells with opposi...

Src kinases in chondrosarcoma chemoresistance and migration: dasatinib sensitises to doxorubicin in TP53 mutant cells

Science.gov (United States)

van Oosterwijk, J G; van Ruler, M A J H; Briaire-de Bruijn, I H; Herpers, B; Gelderblom, H; van de Water, B; Bovée, J V M G

2013-01-01

Background: Chondrosarcomas are malignant cartilage-forming tumours of bone. Because of their resistance to conventional chemotherapy and radiotherapy, currently no treatment strategies exist for unresectable and metastatic chondrosarcoma. Previously, PI3K/AKT/GSK3β and Src kinase pathways were shown to be activated in chondrosarcoma cell lines. Our aim was to investigate the role of these kinases in chemoresistance and migration in chondrosarcoma in relation to TP53 mutation status. Methods: We used five conventional and three dedifferentiated chondrosarcoma cell lines and investigated the effect of PI3K/AKT/GSK3β pathway inhibition (enzastaurin) and Src pathway inhibition (dasatinib) in chemoresistance using WST assay and live cell imaging with AnnexinV staining. Immunohistochemistry on tissue microarrays (TMAs) containing 157 cartilaginous tumours was performed for Src family members. Migration assays were performed with the RTCA xCelligence System. Results: Src inhibition was found to overcome chemoresistance, to induce apoptosis and to inhibit migration. Cell lines with TP53 mutations responded better to combination therapy than wild-type cell lines (P=0.002). Tissue microarray immunohistochemistry confirmed active Src (pSrc) signalling, with Fyn being most abundantly expressed (76.1%). Conclusion: These results strongly indicate Src family kinases, in particular Fyn, as a potential target for the treatment of inoperable and metastatic chondrosarcomas, and to sensitise for doxorubicin especially in the presence of TP53 mutations. PMID:23922104

Endothelial Small- and Intermediate-Conductance KCa Channels

DEFF Research Database (Denmark)

Wulff, Heike; Köhler, Ralf

2013-01-01

ABSTRACT:: Most cardiovascular researchers are familiar with intermediate-conductance KCa3.1 and small-conductance KCa2.3 channels because of their contribution to endothelium-derived hyperpolarization (EDH). However, to immunologists and neuroscientists these channels are primarily known...... for their role in lymphocyte activation and neuronal excitability. KCa3.1 is involved in the proliferation and migration of T cells, B cell, mast cells, macrophages, fibroblasts and dedifferentiated vascular smooth muscle cells and is, therefore, being pursued as a potential target for use in asthma...

In vitro regeneration of selected commercial Tanzanian open ...

African Journals Online (AJOL)

Yomi

2012-03-15

Mar 15, 2012 ... regenerated in vitro using immature zygotic embryos as ex-plants. Callus induction .... Ears were harvested between 12 to 16 days post pollination depending on .... After 28 days of culture on CMM, a mass of dedifferentiated cells .... showed high regeneration ability compared to Situka M-1 that had good ...

Integrative pathway dissection of molecular mechanisms of moxLDL-induced vascular smooth muscle phenotype transformation

Directory of Open Access Journals (Sweden)

Karagiannis George S

2013-01-01

Full Text Available Abstract Background Atherosclerosis (AT is a chronic inflammatory disease characterized by the accumulation of inflammatory cells, lipoproteins and fibrous tissue in the walls of arteries. AT is the primary cause of heart attacks and stroke and is the leading cause of death in Western countries. To date, the pathogenesis of AT is not well-defined. Studies have shown that the dedifferentiation of contractile and quiescent vascular smooth muscle cells (SMC to the proliferative, migratory and synthetic phenotype in the intima is pivotal for the onset and progression of AT. To further delineate the mechanisms underlying the pathogenesis of AT, we analyzed the early molecular pathways and networks involved in the SMC phenotype transformation. Methods Quiescent human coronary artery SMCs were treated with minimally-oxidized LDL (moxLDL, for 3 hours and 21 hours, respectively. Transcriptomic data was generated for both time-points using microarrays and was subjected to pathway analysis using Gene Set Enrichment Analysis, GeneMANIA and Ingenuity software tools. Gene expression heat maps and pathways enriched in differentially expressed genes were compared to identify functional biological themes to elucidate early and late molecular mechanisms of moxLDL-induced SMC dedifferentiation. Results Differentially expressed genes were found to be enriched in cholesterol biosynthesis, inflammatory cytokines, chemokines, growth factors, cell cycle control and myogenic contraction themes. These pathways are consistent with inflammatory responses, cell proliferation, migration and ECM production, which are characteristic of SMC dedifferentiation. Furthermore, up-regulation of cholesterol synthesis and dysregulation of cholesterol metabolism was observed in moxLDL-induced SMC. These observations are consistent with the accumulation of cholesterol and oxidized cholesterol esters, which induce proinflammatory reactions during atherogenesis. Our data implicate for the

Proteomic analysis of blastema formation in regenerating axolotl limbs

Directory of Open Access Journals (Sweden)

Nye Holly LD

2009-11-01

Full Text Available Abstract Background Following amputation, urodele salamander limbs reprogram somatic cells to form a blastema that self-organizes into the missing limb parts to restore the structure and function of the limb. To help understand the molecular basis of blastema formation, we used quantitative label-free liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS-based methods to analyze changes in the proteome that occurred 1, 4 and 7 days post amputation (dpa through the mid-tibia/fibula of axolotl hind limbs. Results We identified 309 unique proteins with significant fold change relative to controls (0 dpa, representing 10 biological process categories: (1 signaling, (2 Ca2+ binding and translocation, (3 transcription, (4 translation, (5 cytoskeleton, (6 extracellular matrix (ECM, (7 metabolism, (8 cell protection, (9 degradation, and (10 cell cycle. In all, 43 proteins exhibited exceptionally high fold changes. Of these, the ecotropic viral integrative factor 5 (EVI5, a cell cycle-related oncoprotein that prevents cells from entering the mitotic phase of the cell cycle prematurely, was of special interest because its fold change was exceptionally high throughout blastema formation. Conclusion Our data were consistent with previous studies indicating the importance of inositol triphosphate and Ca2+ signaling in initiating the ECM and cytoskeletal remodeling characteristic of histolysis and cell dedifferentiation. In addition, the data suggested that blastema formation requires several mechanisms to avoid apoptosis, including reduced metabolism, differential regulation of proapoptotic and antiapoptotic proteins, and initiation of an unfolded protein response (UPR. Since there is virtually no mitosis during blastema formation, we propose that high levels of EVI5 function to arrest dedifferentiated cells somewhere in the G1/S/G2 phases of the cell cycle until they have accumulated under the wound epidermis and enter mitosis in response to

Cytoplasniic differentiation during microsporogenesis in higher plants

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H. Dichinnson

2014-01-01

Full Text Available Conspicuous cytoplasmic dedifferentiation in the pollen mother cells takes place early in the meiotic prophase of many plants. This event involves the removal of much of the cytoplasmic RNA. and the differentiation of both plastids and mitochondria to approaching the sole expression of their genomes. Much of the RNA removed from the cytoplasm passes to the nucleoplasm where it is utilised in the construction of a new `generation' of ribusomes. These new ribosomes are incorporated into cytoplasmic `nuclewhich disintegrate in the post-meiotic cytoplasm, restoring its ribosomes to pre-prophase levels. These changes are interpreted as evidence of a process by which the cytoplasm is cleansed of sporophytic control elements, both for the expression of the new gametophytic genome, and in the female cells of higher plants, for transmission to the new generation. The absence of control elements (presumably long-term messenger RNA from the cytoplasm would result in the dedifferentiation observed in the organelles, and the low levels of reserves in these cells presumably results in characteristically lengthy and unusual redifferentiation of both plastids and mitochondria, once information-carrying molecules again enter the cytosol.

Foxa2 and Pdx1 cooperatively regulate postnatal maturation of pancreatic β-cells

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Aimée Bastidas-Ponce

2017-06-01

Full Text Available Objective: The transcription factors (TF Foxa2 and Pdx1 are key regulators of beta-cell (β-cell development and function. Mutations of these TFs or their respective cis-regulatory consensus binding sites have been linked to maturity diabetes of the young (MODY, pancreas agenesis, or diabetes susceptibility in human. Although Foxa2 has been shown to directly regulate Pdx1 expression during mouse embryonic development, the impact of this gene regulatory interaction on postnatal β-cell maturation remains obscure. Methods: In order to easily monitor the expression domains of Foxa2 and Pdx1 and analyze their functional interconnection, we generated a novel double knock-in homozygous (FVFPBFDHom fluorescent reporter mouse model by crossing the previously described Foxa2-Venus fusion (FVF with the newly generated Pdx1-BFP (blue fluorescent protein fusion (PBF mice. Results: Although adult PBF homozygous animals exhibited a reduction in expression levels of Pdx1, they are normoglycemic. On the contrary, despite normal pancreas and endocrine development, the FVFPBFDHom reporter male animals developed hyperglycemia at weaning age and displayed a reduction in Pdx1 levels in islets, which coincided with alterations in β-cell number and islet architecture. The failure to establish mature β-cells resulted in loss of β-cell identity and trans-differentiation towards other endocrine cell fates. Further analysis suggested that Foxa2 and Pdx1 genetically and functionally cooperate to regulate maturation of adult β-cells. Conclusions: Our data show that the maturation of pancreatic β-cells requires the cooperative function of Foxa2 and Pdx1. Understanding the postnatal gene regulatory network of β-cell maturation will help to decipher pathomechanisms of diabetes and identify triggers to regenerate dedifferentiated β-cell mass. Keywords: Foxa2, Pdx1, β-Cell maturation, β-Cell identity, Trans-differentiation

Recellularization of rat liver: An in vitro model for assessing human drug metabolism and liver biology.

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Matthew J Robertson

Full Text Available Liver-like organoids that recapitulate the complex functions of the whole liver by combining cells, scaffolds, and mechanical or chemical cues are becoming important models for studying liver biology and drug metabolism. The advantages of growing cells in three-dimensional constructs include enhanced cell-cell and cell-extracellular matrix interactions and preserved cellular phenotype including, prevention of de-differentiation. In the current study, biomimetic liver constructs were made via perfusion decellularization of rat liver, with the goal of maintaining the native composition and structure of the extracellular matrix. We optimized our decellularization process to produce liver scaffolds in which immunogenic residual DNA was removed but glycosaminoglycans were maintained. When the constructs were recellularized with rat or human liver cells, the cells remained viable, capable of proliferation, and functional for 28 days. Specifically, the cells continued to express cytochrome P450 genes and maintained their ability to metabolize a model drug, midazolam. Microarray analysis showed an upregulation of genes involved in liver regeneration and fibrosis. In conclusion, these liver constructs have the potential to be used as test beds for studying liver biology and drug metabolism.

Gene expression profile in human induced pluripotent stem cells: Chondrogenic differentiation in vitro, part A

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Suchorska, Wiktoria Maria; Augustyniak, Ewelina; Richter, Magdalena; Trzeciak, Tomasz

2017-01-01

Human induced pluripotent stem cells (hiPSCs) offer promise in regenerative medicine, however more data are required to improve understanding of key aspects of the cell differentiation process, including how specific chondrogenic processes affect the gene expression profile of chondrocyte-like cells and the relative value of cell differentiation markers. The main aims of the present study were as follows: To determine the gene expression profile of chondrogenic-like cells derived from hiPSCs cultured in mediums conditioned with HC-402-05a cells or supplemented with transforming growth factor β3 (TGF-β3), and to assess the relative utility of the most commonly used chondrogenic markers as indicators of cell differentiation. These issues are relevant with regard to the use of human fibroblasts in the reprogramming process to obtain hiPSCs. Human fibroblasts are derived from the mesoderm and thus share a wide range of properties with chondrocytes, which also originate from the mesenchyme. Thus, the exclusion of dedifferentiation instead of chondrogenic differentiation is crucial. The hiPSCs were obtained from human primary dermal fibroblasts during a reprogramming process. Two methods, both involving embryoid bodies (EB), were used to obtain chondrocytes from the hiPSCs: EBs formed in a chondrogenic medium supplemented with TGF-β3 (10 ng/ml) and EBs formed in a medium conditioned with growth factors from HC-402-05a cells. Based on immunofluorescence and reverse transcription-quantiative polymerase chain reaction analysis, the results indicated that hiPSCs have the capacity for effective chondrogenic differentiation, in particular cells differentiated in the HC-402-05a-conditioned medium, which present morphological features and markers that are characteristic of mature human chondrocytes. By contrast, cells differentiated in the presence of TGF-β3 may demonstrate hypertrophic characteristics. Several genes [paired box 9, sex determining region Y-box (SOX) 5, SOX6

A new and improved algorithm for the quantification of chromatin condensation from microscopic data shows decreased chromatin condensation in regenerating axolotl limb cells.

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Julian Sosnik

Full Text Available The nuclear landscape plays an important role in the regulation of tissue and positional specific genes in embryonic and developing cells. Changes in this landscape can be dynamic, and are associated with the differentiation of cells during embryogenesis, and the de-differentiation of cells during induced pluripotent stem cell (iPSC formation and in many cancers. However, tools to quantitatively characterize these changes are limited, especially in the in vivo context, where numerous tissue types are present and cells are arranged in multiple layers. Previous tools have been optimized for the monolayer nature of cultured cells. Therefore, we present a new algorithm to quantify the condensation of chromatin in two in vivo systems. We first developed this algorithm to quantify changes in chromatin compaction and validated it in differentiating spermatids in zebrafish testes. Our algorithm successfully detected the typical increase in chromatin compaction as these cells differentiate. We then employed the algorithm to quantify the changes that occur in amphibian limb cells as they participate in a regenerative response. We observed that the chromatin in the limb cells de-compacts as they contribute to the regenerating organ. We present this new tool as an open sourced software that can be readily accessed and optimized to quantify chromatin compaction in complex multi-layered samples.

Electrophysiological heterogeneity of pacemaker cells in the rabbit intercaval region, including the SA node: insights from recording multiple ion currents in each cell.

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Monfredi, Oliver; Tsutsui, Kenta; Ziman, Bruce; Stern, Michael D; Lakatta, Edward G; Maltsev, Victor A

2018-03-01

Cardiac pacemaker cells, including cells of the sinoatrial node, are heterogeneous in size, morphology, and electrophysiological characteristics. The exact extent to which these cells differ electrophysiologically is unclear yet is critical to understanding their functioning. We examined major ionic currents in individual intercaval pacemaker cells (IPCs) sampled from the paracristal, intercaval region (including the sinoatrial node) that were spontaneously beating after enzymatic isolation from rabbit hearts. The beating rate was measured at baseline and after inhibition of the Ca 2+ pump with cyclopiazonic acid. Thereafter, in each cell, we consecutively measured the density of funny current ( I f ), delayed rectifier K + current ( I K ) (a surrogate of repolarization capacity), and L-type Ca 2+ current ( I Ca,L ) using whole cell patch clamp . The ionic current densities varied to a greater extent than previously appreciated, with some IPCs demonstrating very small or zero I f . The density of none of the currents was correlated with cell size, while I Ca,L and I f densities were related to baseline beating rates. I f density was correlated with I K density but not with that of I Ca,L . Inhibition of Ca 2+ cycling had a greater beating rate slowing effect in IPCs with lower I f densities. Our numerical model simulation indicated that 1) IPCs with small (or zero) I f or small I Ca,L can operate via a major contribution of Ca 2+ clock, 2) I f -Ca 2+ -clock interplay could be important for robust pacemaking function, and 3) coupled I f - I K function could regulate maximum diastolic potential. Thus, we have demonstrated marked electrophysiological heterogeneity of IPCs. This heterogeneity is manifested in basal beating rate and response to interference of Ca 2+ cycling, which is linked to I f . NEW & NOTEWORTHY In the present study, a hitherto unrecognized range of heterogeneity of ion currents in pacemaker cells from the intercaval region is demonstrated

BMP-2, hypoxia, and COL1A1/HtrA1 siRNAs favor neo-cartilage hyaline matrix formation in chondrocytes.

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Ollitrault, David; Legendre, Florence; Drougard, Carole; Briand, Mélanie; Benateau, Hervé; Goux, Didier; Chajra, Hanane; Poulain, Laurent; Hartmann, Daniel; Vivien, Denis; Shridhar, Vijayalakshmi; Baldi, Alfonso; Mallein-Gerin, Frédéric; Boumediene, Karim; Demoor, Magali; Galera, Philippe

2015-02-01

Osteoarthritis (OA) is an irreversible pathology that causes a decrease in articular cartilage thickness, leading finally to the complete degradation of the affected joint. The low spontaneous repair capacity of cartilage prevents any restoration of the joint surface, making OA a major public health issue. Here, we developed an innovative combination of treatment conditions to improve the human chondrocyte phenotype before autologous chondrocyte implantation. First, we seeded human dedifferentiated chondrocytes into a collagen sponge as a scaffold, cultured them in hypoxia in the presence of a bone morphogenetic protein (BMP), BMP-2, and transfected them with small interfering RNAs targeting two markers overexpressed in OA dedifferentiated chondrocytes, that is, type I collagen and/or HtrA1 serine protease. This strategy significantly decreased mRNA and protein expression of type I collagen and HtrA1, and led to an improvement in the chondrocyte phenotype index of differentiation. The effectiveness of our in vitro culture process was also demonstrated in the nude mouse model in vivo after subcutaneous implantation. We, thus, provide here a new protocol able to favor human hyaline chondrocyte phenotype in primarily dedifferentiated cells, both in vitro and in vivo. Our study also offers an innovative strategy for chondrocyte redifferentiation and opens new opportunities for developing therapeutic targets.

Msx1-modulated muscle satellite cells retain a primitive state and exhibit an enhanced capacity for osteogenic differentiation

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Ding, Ke, E-mail: dingke@med.uestc.edu.cn [Department of Pediatric Surgery, School of medicine, University of Electronic Science and Technology of China, Chengdu 610072 (China); Sichuan Academy of Medical Sciences & Sichuan Provincial People' s Hospital, Chengdu 610072 (China); Department of Orthopaedics, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Liu, Wen-ying; Zeng, Qiang; Hou, Fang [Department of Pediatric Surgery, School of medicine, University of Electronic Science and Technology of China, Chengdu 610072 (China); Sichuan Academy of Medical Sciences & Sichuan Provincial People' s Hospital, Chengdu 610072 (China); Xu, Jian-zhong, E-mail: xjzspine@163.com [Department of Orthopaedics, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China); Yang, Zhong, E-mail: zyang1999@163.com [Department of Clinical Hematology, Southwest Hospital, Third Military Medical University, Chongqing 400038 (China)

2017-03-01

Multipotent muscle satellite cells (MuSCs) have been identified as potential seed cells for bone tissue engineering. However, MuSCs exhibit a rapid loss of stemness after in vitro culturing, thereby compromising their therapeutic efficiency. Muscle segment homeobox gene 1 (msx1) has been found to induce the dedifferentiation of committed progenitor cells, as well as terminally differentiated myotubes. In this study, a Tet-off retroviral gene delivery system was used to modulate msx1 expression. After ten passages, MuSCs that did not express msx-1 (e.g., the non-msx1 group) were compared with MuSCs with induced msx-1 expression (e.g., the msx1 group). The latter group exhibited a more juvenile morphology, it contained a significantly lower percentage of senescent cells characterized by positive β-galactosidase staining, and it exhibited increased proliferation and a higher proliferation index. Immunocytochemical stainings further detected a more primitive gene expression profile for the msx1 group, while osteogenic differentiation assays and ectopic bone formation assays demonstrated an improved capacity for the msx1 group to undergo osteogenic differentiation. These results suggest that transient expression of msx1 in MuSCs can retain a primitive state, thereby enhancing their capacity for osteogenic differentiation and restoring the potential for MuSCs to serve as seed cells for bone tissue engineering.

Msx1-modulated muscle satellite cells retain a primitive state and exhibit an enhanced capacity for osteogenic differentiation

International Nuclear Information System (INIS)

Ding, Ke; Liu, Wen-ying; Zeng, Qiang; Hou, Fang; Xu, Jian-zhong; Yang, Zhong

2017-01-01

Multipotent muscle satellite cells (MuSCs) have been identified as potential seed cells for bone tissue engineering. However, MuSCs exhibit a rapid loss of stemness after in vitro culturing, thereby compromising their therapeutic efficiency. Muscle segment homeobox gene 1 (msx1) has been found to induce the dedifferentiation of committed progenitor cells, as well as terminally differentiated myotubes. In this study, a Tet-off retroviral gene delivery system was used to modulate msx1 expression. After ten passages, MuSCs that did not express msx-1 (e.g., the non-msx1 group) were compared with MuSCs with induced msx-1 expression (e.g., the msx1 group). The latter group exhibited a more juvenile morphology, it contained a significantly lower percentage of senescent cells characterized by positive β-galactosidase staining, and it exhibited increased proliferation and a higher proliferation index. Immunocytochemical stainings further detected a more primitive gene expression profile for the msx1 group, while osteogenic differentiation assays and ectopic bone formation assays demonstrated an improved capacity for the msx1 group to undergo osteogenic differentiation. These results suggest that transient expression of msx1 in MuSCs can retain a primitive state, thereby enhancing their capacity for osteogenic differentiation and restoring the potential for MuSCs to serve as seed cells for bone tissue engineering.

Msx1-modulated muscle satellite cells retain a primitive state and exhibit an enhanced capacity for osteogenic differentiation.

Science.gov (United States)

Ding, Ke; Liu, Wen-Ying; Zeng, Qiang; Hou, Fang; Xu, Jian-Zhong; Yang, Zhong

2017-03-01

Multipotent muscle satellite cells (MuSCs) have been identified as potential seed cells for bone tissue engineering. However, MuSCs exhibit a rapid loss of stemness after in vitro culturing, thereby compromising their therapeutic efficiency. Muscle segment homeobox gene 1 (msx1) has been found to induce the dedifferentiation of committed progenitor cells, as well as terminally differentiated myotubes. In this study, a Tet-off retroviral gene delivery system was used to modulate msx1 expression. After ten passages, MuSCs that did not express msx-1 (e.g., the non-msx1 group) were compared with MuSCs with induced msx-1 expression (e.g., the msx1 group). The latter group exhibited a more juvenile morphology, it contained a significantly lower percentage of senescent cells characterized by positive β-galactosidase staining, and it exhibited increased proliferation and a higher proliferation index. Immunocytochemical stainings further detected a more primitive gene expression profile for the msx1 group, while osteogenic differentiation assays and ectopic bone formation assays demonstrated an improved capacity for the msx1 group to undergo osteogenic differentiation. These results suggest that transient expression of msx1 in MuSCs can retain a primitive state, thereby enhancing their capacity for osteogenic differentiation and restoring the potential for MuSCs to serve as seed cells for bone tissue engineering. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of the extracellular matrix on endogenous and transplanted stem cells after brain damage

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Lars eRoll

2014-08-01

Full Text Available The limited regeneration capacity of the adult central nervous system requires strategies to improve recovery of patients. In this context, the interaction of endogenous as well as transplanted stem cells with their environment is crucial. An understanding of the molecular mechanisms could help to improve regeneration by targeted manipulation.In the course of reactive gliosis, astrocytes upregulate Glial fibrillary acidic protein (GFAP and start, in many cases, to proliferate. Beside GFAP, subpopulations of these astroglial cells coexpress neural progenitor markers like Nestin. Although cells express these markers, the proportion of cells that eventually give rise to neurons is limited in many cases in vivo compared to the situation in vitro. In the first section, we present the characteristics of endogenous progenitor-like cells and discuss the differences in their neurogenic potential in vitro and in vivo.As the environment plays an important role for survival, proliferation, migration, and other processes, the second section of the review describes changes in the extracellular matrix (ECM, a complex network that contains numerous signaling molecules. It appears that signals in the damaged central nervous system lead to an activation and de-differentiation of astrocytes, but do not effectively promote neuronal differentiation of these cells. Factors that influence stem cells during development are upregulated in the damaged brain as part of an environment resembling a stem cell niche. We give a general description of the ECM composition, with focus on stem cell-associated factors like the glycoprotein Tenascin-C.Stem cell transplantation is considered as potential treatment strategy. Interaction of transplanted stem cells with the host environment is critical for the outcome of stem cell-based therapies. Possible mechanisms involving the ECM by which transplanted stem cells might improve recovery are discussed in the last section.

A comparative study of cell cycle mediator protein expression patterns in anaplastic and papillary thyroid carcinoma.

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Evans, Juanita J; Crist, Henry S; Durvesh, Saima; Bruggeman, Richard D; Goldenberg, David

2012-07-01

Anaplastic thyroid carcinoma (ATC) is an extremely aggressive and rapidly fatal neoplasm. The aim of this study was to identify a limited cell cycle associated protein expression pattern unique to ATC and to correlate that pattern with clinical outcome. This represents one of the largest tissue micro-array projects comparing the cell cycle protein expression data of ATC to other well-differentiated tumors in the literature. Tissue microarrays were created from 21 patients with ATC and an age and gender matched cohort of patients with papillary thyroid carcinoma (PTC). Expression of epidermal growth factor receptor, cyclin D1, cyclin E, p53, p21, p16, aurora kinase A, opioid growth factor (OGF), OGF-receptor, thyroglobulin and Ki-67 was evaluated in a semi-quantitative fashion. Differences in protein expression between the cohorts were evaluated using chi-square tests with Bonferroni adjustments. Survival time and presence of metastasis at presentation were collected. The ATC cohort showed a statistically significant decrease (p cycle with aberrant expression of multiple protein markers suggesting increased proliferative activity and loss of control of cell cycle progression to G₁ phase. These findings support the assertion that ATC may represent the furthest end of a continuum of thyroid carcinoma dedifferentiation.

Solution structure and phylogenetics of Prod1, a member of the three-finger protein superfamily implicated in salamander limb regeneration.

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Acely Garza-Garcia

Full Text Available BACKGROUND: Following the amputation of a limb, newts and salamanders have the capability to regenerate the lost tissues via a complex process that takes place at the site of injury. Initially these cells undergo dedifferentiation to a state competent to regenerate the missing limb structures. Crucially, dedifferentiated cells have memory of their level of origin along the proximodistal (PD axis of the limb, a property known as positional identity. Notophthalmus viridescens Prod1 is a cell-surface molecule of the three-finger protein (TFP superfamily involved in the specification of newt limb PD identity. The TFP superfamily is a highly diverse group of metazoan proteins that includes snake venom toxins, mammalian transmembrane receptors and miscellaneous signaling molecules. METHODOLOGY/PRINCIPAL FINDINGS: With the aim of identifying potential orthologs of Prod1, we have solved its 3D structure and compared it to other known TFPs using phylogenetic techniques. The analysis shows that TFP 3D structures group in different categories according to function. Prod1 clusters with other cell surface protein TFP domains including the complement regulator CD59 and the C-terminal domain of urokinase-type plasminogen activator. To infer orthology, a structure-based multiple sequence alignment of representative TFP family members was built and analyzed by phylogenetic methods. Prod1 has been proposed to be the salamander CD59 but our analysis fails to support this association. Prod1 is not a good match for any of the TFP families present in mammals and this result was further supported by the identification of the putative orthologs of both CD59 and N. viridescens Prod1 in sequence data for the salamander Ambystoma tigrinum. CONCLUSIONS/SIGNIFICANCE: The available data suggest that Prod1, and thereby its role in encoding PD identity, is restricted to salamanders. The lack of comparable limb-regenerative capability in other adult vertebrates could be

Analysis of electronic models for solar cells including energy resolved defect densities

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Glitzky, Annegret

2010-07-01

We introduce an electronic model for solar cells including energy resolved defect densities. The resulting drift-diffusion model corresponds to a generalized van Roosbroeck system with additional source terms coupled with ODEs containing space and energy as parameters for all defect densities. The system has to be considered in heterostructures and with mixed boundary conditions from device simulation. We give a weak formulation of the problem. If the boundary data and the sources are compatible with thermodynamic equilibrium the free energy along solutions decays monotonously. In other cases it may be increasing, but we estimate its growth. We establish boundedness and uniqueness results and prove the existence of a weak solution. This is done by considering a regularized problem, showing its solvability and the boundedness of its solutions independent of the regularization level. (orig.)

Hardware-in-the-loop vehicle system including dynamic fuel cell model

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Lemes, Z.; Lenhart, T.; Braun, M.; Maencher, H. [MAGNUM Automatisierungstechnik GmbH, Darmstadt (Germany)

2005-07-01

In order to reduce costs and accelerate the development of fuel cells and systems the usage of hardware-in-the-loop (HIL) testing and dynamic modelling opens new possibilities. The dynamic model of a proton exchange membrane fuel cell (PEMFC) together with a vehicle model is used to carry out a comprehensive system investigation, which allows designing and optimising the behaviour of the components and the entire fuel cell system. The set-up of a HIL system enables real time interaction between the selected hardware and the model. (orig.)

Localization and characterization of STRO-1 cells in the deer pedicle and regenerating antler.

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Hans J Rolf

2008-04-01

Full Text Available The annual regeneration of deer antlers is a unique developmental event in mammals, which as a rule possess only a very limited capacity to regenerate lost appendages. Studying antler regeneration can therefore provide a deeper insight into the mechanisms that prevent limb regeneration in humans and other mammals, and, with regard to medical treatments, may possibly even show ways how to overcome these limitations. Traditionally, antler regeneration has been characterized as a process involving the formation of a blastema from de-differentiated cells. More recently it has, however, been hypothesized that antler regeneration is a stem cell-based process. Thus far, direct evidence for the presence of stem cells in primary or regenerating antlers was lacking. Here we demonstrate the presence of cells positive for the mesenchymal stem cell marker STRO-1 in the chondrogenic growth zone and the perivascular tissue of the cartilaginous zone in primary and regenerating antlers as well as in the pedicle of fallow deer (Dama dama. In addition, cells positive for the stem cell/progenitor cell markers STRO-1, CD133 and CD271 (LNGFR were isolated from the growth zones of regenerating fallow deer antlers as well as the pedicle periosteum and cultivated for extended periods of time. We found evidence that STRO-1(+ cells isolated from the different locations are able to differentiate in vitro along the osteogenic and adipogenic lineages. Our results support the view that the annual process of antler regeneration might depend on the periodic activation of mesenchymal progenitor cells located in the pedicle periosteum. The findings of the present study indicate that not only limited tissue regeneration, but also extensive appendage regeneration in a postnatal mammal can occur as a stem cell-based process.

In-depth evaluation of commercially available human vascular smooth muscle cells phenotype: Implications for vascular tissue engineering

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Timraz, Sara B.H., E-mail: sara.timraz@kustar.ac.ae [Department of Biomedical Engineering, Khalifa University, PO Box 127788, Abu Dhabi (United Arab Emirates); Farhat, Ilyas A.H., E-mail: ilyas.farhat@outlook.com [Department of Applied Mathematics and Sciences, Khalifa University, PO Box 127788, Abu Dhabi (United Arab Emirates); Alhussein, Ghada, E-mail: ghada.alhussein@kustar.ac.ae [Department of Biomedical Engineering, Khalifa University, PO Box 127788, Abu Dhabi (United Arab Emirates); Christoforou, Nicolas, E-mail: nicolas.christoforou@kustar.ac.ae [Department of Biomedical Engineering, Khalifa University, PO Box 127788, Abu Dhabi (United Arab Emirates); Department of Biomedical Engineering, Duke University, Durham, NC 27708 (United States); Teo, Jeremy C.M., E-mail: jeremy.teo@kustar.ac.ae [Department of Biomedical Engineering, Khalifa University, PO Box 127788, Abu Dhabi (United Arab Emirates)

2016-05-01

In vitro research on vascular tissue engineering has extensively used isolated primary human or animal smooth muscle cells (SMC). Research programs that lack such facilities tend towards commercially available primary cells sources. Here, we aim to evaluate the capacity of commercially available human SMC to maintain their contractile phenotype, and determine if dedifferentiation towards the synthetic phenotype occurs in response to conventional cell culture and passaging without any external biochemical or mechanical stimuli. Lower passage SMC adopted a contractile phenotype marked by a relatively slower proliferation rate, higher expression of proteins of the contractile apparatus and smoothelin, elongated morphology, and reduced deposition of collagen types I and III. As the passage number increased, migratory capacity was enhanced, average cell speed, total distance and net distance travelled increased up to passage 8. Through the various assays, corroborative evidence pinpoints SMC at passage 7 as the transition point between the contractile and synthetic phenotypes, while passage 8 distinctly and consistently exhibited characteristics of synthetic phenotype. This knowledge is particularly useful in selecting SMC of appropriate passage number for the target vascular tissue engineering application, for example, a homeostatic vascular graft for blood vessel replacement versus recreating atherosclerotic blood vessel model in vitro. - Highlights: • Ability of human smooth muscle cells to alter phenotype in culture is evaluated. • Examined the effect of passaging human smooth muscle cells on phenotype. • Phenotype is assessed based on morphology, proliferation, markers, and migration. • Multi-resolution assessment methodology, single-cell and cell-population. • Lower and higher passages than P7 adopted a contractile and synthetic phenotype respectively.

In-depth evaluation of commercially available human vascular smooth muscle cells phenotype: Implications for vascular tissue engineering

International Nuclear Information System (INIS)

Timraz, Sara B.H.; Farhat, Ilyas A.H.; Alhussein, Ghada; Christoforou, Nicolas; Teo, Jeremy C.M.

2016-01-01

In vitro research on vascular tissue engineering has extensively used isolated primary human or animal smooth muscle cells (SMC). Research programs that lack such facilities tend towards commercially available primary cells sources. Here, we aim to evaluate the capacity of commercially available human SMC to maintain their contractile phenotype, and determine if dedifferentiation towards the synthetic phenotype occurs in response to conventional cell culture and passaging without any external biochemical or mechanical stimuli. Lower passage SMC adopted a contractile phenotype marked by a relatively slower proliferation rate, higher expression of proteins of the contractile apparatus and smoothelin, elongated morphology, and reduced deposition of collagen types I and III. As the passage number increased, migratory capacity was enhanced, average cell speed, total distance and net distance travelled increased up to passage 8. Through the various assays, corroborative evidence pinpoints SMC at passage 7 as the transition point between the contractile and synthetic phenotypes, while passage 8 distinctly and consistently exhibited characteristics of synthetic phenotype. This knowledge is particularly useful in selecting SMC of appropriate passage number for the target vascular tissue engineering application, for example, a homeostatic vascular graft for blood vessel replacement versus recreating atherosclerotic blood vessel model in vitro. - Highlights: • Ability of human smooth muscle cells to alter phenotype in culture is evaluated. • Examined the effect of passaging human smooth muscle cells on phenotype. • Phenotype is assessed based on morphology, proliferation, markers, and migration. • Multi-resolution assessment methodology, single-cell and cell-population. • Lower and higher passages than P7 adopted a contractile and synthetic phenotype respectively.

Differentially regulated splice variants and systems biology analysis of Kaposi's sarcoma-associated herpesvirus-infected lymphatic endothelial cells.

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Chang, Ting-Yu; Wu, Yu-Hsuan; Cheng, Cheng-Chung; Wang, Hsei-Wei

2011-09-01

Alternative RNA splicing greatly increases proteome diversity, and the possibility of studying genome-wide alternative splicing (AS) events becomes available with the advent of high-throughput genomics tools devoted to this issue. Kaposi's sarcoma associated herpesvirus (KSHV) is the etiological agent of KS, a tumor of lymphatic endothelial cell (LEC) lineage, but little is known about the AS variations induced by KSHV. We analyzed KSHV-controlled AS using high-density microarrays capable of detecting all exons in the human genome. Splicing variants and altered exon-intron usage in infected LEC were found, and these correlated with protein domain modification. The different 3'-UTR used in new transcripts also help isoforms to escape microRNA-mediated surveillance. Exome-level analysis further revealed information that cannot be disclosed using classical gene-level profiling: a significant exon usage difference existed between LEC and CD34(+) precursor cells, and KSHV infection resulted in LEC-to-precursor, dedifferentiation-like exon level reprogramming. Our results demonstrate the application of exon arrays in systems biology research, and suggest the regulatory effects of AS in endothelial cells are far more complex than previously observed. This extra layer of molecular diversity helps to account for various aspects of endothelial biology, KSHV life cycle and disease pathogenesis that until now have been unexplored.

Insect biofuel cells using trehalose included in insect hemolymph leading to an insect-mountable biofuel cell.

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Shoji, Kan; Akiyama, Yoshitake; Suzuki, Masato; Hoshino, Takayuki; Nakamura, Nobuhumi; Ohno, Hiroyuki; Morishima, Keisuke

2012-12-01

In this paper, an insect biofuel cell (BFC) using trehalose included in insect hemolymph was developed. The insect BFC is based on trehalase and glucose oxidase (GOD) reaction systems which oxidize β-glucose obtained by hydrolyzing trehalose. First, we confirmed by LC-MS that a sufficient amount of trehalose was present in the cockroach hemolymph (CHL). The maximum power density obtained using the insect BFC was 6.07 μW/cm(2). The power output was kept more than 10 % for 2.5 h by protecting the electrodes with a dialysis membrane. Furthermore, the maximum power density was increased to 10.5 μW/cm(2) by using an air diffusion cathode. Finally, we succeeded in driving a melody integrated circuit (IC) and a piezo speaker by connecting five insect BFCs in series. The results indicate that the insect BFC is a promising insect-mountable battery to power environmental monitoring micro-tools.

Myeloid-derived suppressor cells in murine AIDS inhibit B-cell responses in part via soluble mediators including reactive oxygen and nitrogen species, and TGF-β

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Rastad, Jessica L. [Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756 (United States); Green, William R., E-mail: William.R.Green@dartmouth.edu [Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756 (United States); Norris Cotton Cancer Center, Geisel School of Medicine at Dartmouth, Lebanon, NH 03756 (United States)

2016-12-15

Monocytic myeloid-derived suppressor cells (M-MDSCs) were increased during LP-BM5 retroviral infection, and were capable of suppressing not only T-cell, but also B-cell responses. In addition to previously demonstrating iNOS- and VISTA-dependent M-MDSC mechanisms, in this paper, we detail how M-MDSCs utilized soluble mediators, including the reactive oxygen and nitrogen species superoxide, peroxynitrite, and nitric oxide, and TGF-β, to suppress B cells in a predominantly contact-independent manner. Suppression was independent of cysteine-depletion and hydrogen peroxide production. When two major mechanisms of suppression (iNOS and VISTA) were eliminated in double knockout mice, M-MDSCs from LP-BM5-infected mice were able to compensate using other, soluble mechanisms in order to maintain suppression of B cells. The IL-10 producing regulatory B-cell compartment was among the targets of M-MDSC-mediated suppression. -- Highlights: •LP-BM5-expanded M-MDSCs utilized soluble mediators nitric oxide, superoxide, peroxynitrite, and TGF-β to suppress B cells. •When two major mechanisms of suppression were eliminated through knockouts, M-MDSCs maintained suppression. •M-MDSCs from LP-BM5-infected mice decreased proliferation of IL-10 producing regulatory B cells.

Myeloid-derived suppressor cells in murine AIDS inhibit B-cell responses in part via soluble mediators including reactive oxygen and nitrogen species, and TGF-β

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Rastad, Jessica L.; Green, William R.

2016-01-01

Monocytic myeloid-derived suppressor cells (M-MDSCs) were increased during LP-BM5 retroviral infection, and were capable of suppressing not only T-cell, but also B-cell responses. In addition to previously demonstrating iNOS- and VISTA-dependent M-MDSC mechanisms, in this paper, we detail how M-MDSCs utilized soluble mediators, including the reactive oxygen and nitrogen species superoxide, peroxynitrite, and nitric oxide, and TGF-β, to suppress B cells in a predominantly contact-independent manner. Suppression was independent of cysteine-depletion and hydrogen peroxide production. When two major mechanisms of suppression (iNOS and VISTA) were eliminated in double knockout mice, M-MDSCs from LP-BM5-infected mice were able to compensate using other, soluble mechanisms in order to maintain suppression of B cells. The IL-10 producing regulatory B-cell compartment was among the targets of M-MDSC-mediated suppression. -- Highlights: •LP-BM5-expanded M-MDSCs utilized soluble mediators nitric oxide, superoxide, peroxynitrite, and TGF-β to suppress B cells. •When two major mechanisms of suppression were eliminated through knockouts, M-MDSCs maintained suppression. •M-MDSCs from LP-BM5-infected mice decreased proliferation of IL-10 producing regulatory B cells.

Immunohistochemical detection of vimentin in pancreatic islet β- and α-cells of macrosomic infants of diabetic and nondiabetic mothers.

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Krivova, Yuliya S; Proshchina, Alexandra E; Barabanov, Valeriy M; Barinova, Irina V; Saveliev, Sergey V

2018-02-01

Expression of the intermediate filament protein vimentin has been recently observed in the pancreatic islet β- and α-cells of humans with type 2 diabetes mellitus. It was suggested that the presence of vimentin in endocrine cells may indicate islet tissue renewal, or potentially represent the dedifferentiation of endocrine cells, which could contribute to the onset of type 2 diabetes or islet cell dysfunction. To analyze the expression of vimentin in pancreatic β- and α-cells of macrosomic infants of diabetic and nondiabetic mothers. Pancreatic samples of five macrosomic infants (gestational age 34-40weeks) from three diabetic and two nondiabetic mothers were compared to six control infants (32-40weeks, weight appropriate for gestational age) from normoglycemic mothers. Pancreatic autopsy samples were examined by double immunofluorescent labeling with antibodies against vimentin and either insulin or glucagon. Alterations in the endocrine pancreas were measured using morphometric methods, then data were statistically analyzed. In the pancreatic islets of macrosomic infants from diabetic and nondiabetic mothers, we observed vimentin-positive cells, some of which simultaneously contained insulin or glucagon. We also quantitatively showed that the presence of such cells was associated with hypertrophy and hyperplasia of the islets, and with an increase in β- and α-cell density. We speculate that the appearance of vimentin-positive islet cells may reflect induction of differentiation in response to the increased insulin demand, and vimentin may serve as an early marker of endocrine pancreas disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of cells recovered from the xenotransplanted NG97 human-derived glioma cell line subcultured in a long-term in vitro

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Heinrich Juliana K

2008-10-01

Full Text Available Abstract Background In order to elucidate tumoral progression and drug resistance, cultured cell lines are valuable tools applied on tumor related assays provided they are well established and characterized. Our laboratory settled the NG97 cell line derived from a human astrocytoma grade III, which started to develop and express important phenotypical characteristics of an astrocytoma grade IV after injection in the flank of nude mice. Astrocytomas are extremely aggressive malignancies of the Central Nervous System (CNS and account for 46% of all primary malignant brain tumors. Progression to worse prognosis occurs in 85% of the cases possibly due to changes in cell tumor microenvironment and through biological pathways that are still unclear. Methods This work focused on characterizing the NG97 cell line specifically after being recovered from the xenotransplant, who maintained their undifferentiated characteristics along the following 60th passages in vitro. These cells were subcultivated to evaluate the possible contribution of these undifferentiated characteristics to the malignant progression phenotype. These characteristics were the expression of molecules involved in the processes of migration, dedifferentiation and chromosomal instability. Results Results showed that NG97(ht had an decrease in doubling time through sub cultivation, which was characterized by a converse modulation between the expression of glial fibrillary acidic protein (GFAP and vimentin. In addition, β1 integrins were present in intermediate levels while α5 integrins had a high expression profile as well as fibronectin and laminin. Cytogenetic analysis of NG97(ht revealed several chromosomal abnormalities, 89% of the cells showed to be hyperdiploid and the modal number was assigned to be 63. Several acrocentric chromosomes were visualized and at least 30 figures were attributed to be murine. These findings suggest a possible fusion between the original NG97 cells

Characterization of cells recovered from the xenotransplanted NG97 human-derived glioma cell line subcultured in a long-term in vitro

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Machado, Camila ML; Boetcher-Luiz, Fátima; Verinaud, Liana; Ikemori, Rafael Y; Zorzeto, Tatiana Q; Nogueira, Ana CMA; Barbosa, Suse DS; Savino, Wilson; Schenka, André A; Vassallo, José; Heinrich, Juliana K

2008-01-01

In order to elucidate tumoral progression and drug resistance, cultured cell lines are valuable tools applied on tumor related assays provided they are well established and characterized. Our laboratory settled the NG97 cell line derived from a human astrocytoma grade III, which started to develop and express important phenotypical characteristics of an astrocytoma grade IV after injection in the flank of nude mice. Astrocytomas are extremely aggressive malignancies of the Central Nervous System (CNS) and account for 46% of all primary malignant brain tumors. Progression to worse prognosis occurs in 85% of the cases possibly due to changes in cell tumor microenvironment and through biological pathways that are still unclear. This work focused on characterizing the NG97 cell line specifically after being recovered from the xenotransplant, who maintained their undifferentiated characteristics along the following 60 th passages in vitro. These cells were subcultivated to evaluate the possible contribution of these undifferentiated characteristics to the malignant progression phenotype. These characteristics were the expression of molecules involved in the processes of migration, dedifferentiation and chromosomal instability. Results showed that NG97(ht) had an decrease in doubling time through sub cultivation, which was characterized by a converse modulation between the expression of glial fibrillary acidic protein (GFAP) and vimentin. In addition, β1 integrins were present in intermediate levels while α5 integrins had a high expression profile as well as fibronectin and laminin. Cytogenetic analysis of NG97(ht) revealed several chromosomal abnormalities, 89% of the cells showed to be hyperdiploid and the modal number was assigned to be 63. Several acrocentric chromosomes were visualized and at least 30 figures were attributed to be murine. These findings suggest a possible fusion between the original NG97 cells with stromal murine cells in the xenotransplant. In

Rex3 (reduced in expression 3) as a new tumor marker in mouse hepatocarcinogenesis

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Braeuning, Albert; Jaworski, Maike; Schwarz, Michael; Koehle, Christoph

2006-01-01

In a previous microarray expression analysis, Rex3, a gene formerly not linked to tumor formation, was found to be highly overexpressed in both Ctnnb1-(β-Catenin) and Ha-ras-mutated mouse liver tumors. Subsequent analyses by in situ hybridization and real-time PCR confirmed a general liver tumor-specific overexpression of the gene (up to 400-fold). To investigate the role of Rex3 in liver tumors, hepatoma cells were transfected with FLAG- and Myc-tagged Rex3 expression vectors. Rex3 was shown to be exclusively localized to the cytoplasm, as determined by fluorescence microscopy and Western blotting. However, forced overexpression of Rex3 did not significantly affect proliferation or stress-induced apoptosis of transfected mouse hepatoma cells. Rex3 mRNA was determined in primary hepatocytes in culture by real-time PCR. In primary mouse hepatocytes, expression of Rex3 increased while cells dedifferentiated in culture. This effect was abolished when hepatocytes were maintained in a differentiated state. Furthermore, expression of Rex3 decreased in mouse liver with age of mice and the expression profile was highly correlated to that of the tumor markers α-fetoprotein and H19. The findings suggest a role of Rex3 as a marker for hepatocyte differentiation/dedifferentiation processes and tumor formation

Adipogenic differentiation by adipose-derived stem cells harvested from GFP transgenic mice - including relationship of sex differences

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Ogawa, Rei; Mizuno, Hiroshi; Watanabe, Atsushi; Migita, Makoto; Hyakusoku, Hiko; Shimada, Takashi

2004-01-01

We have previously demonstrated that adipose-derived stromal cells (ASCs) as well as bone marrow-derived stromal cells (BSCs) differentiate into a variety of cell lineages both in vitro and in vivo. Both types are considered to include mesenchymal stem cells. Taking advantage of homogeneously marked cells from green fluorescent protein (GFP) transgenic mice, we have also previously reported the plasticity of BSCs and ASCs. In this study, we focused on adipogenic differentiation in vitro by ASCs harvested from GFP transgenic mice. Moreover, preadipocytes and mature adipocytes were harvested at the same time, and the cells were cultured to compare them with ASCs. Inguinal fat pads from GFP transgenic mice were used for the isolation of ASCs, preadipocytes, and mature adipocytes. After expansion to three passages of ASCs, the cells were incubated in an adipogenic medium for two weeks. Adipogenic differentiation of ASCs was assessed by Oil Red O staining and the expression of the adipocyte specific peroxisome proliferative activated receptor γ2 (PPAR-γ2) gene. These ASCs stained positively, and expression of PPAR-γ2 was detected. Moreover, we also tried to characterize the influence of sex differences on the adipogenic differentiation of ASCs harvested from both male and female mice. This was assessed by the expression levels of the PPAR-γ2 gene using real-time PCR. The results showed that the expression levels of ASCs harvested from female mice were a maximum of 2.89 times greater than those harvested from male mice. This suggests that the adipogenic differentiation of ASCs is closely related to sex differences

Role of Insulin-Transferrin-Selenium in Auricular Chondrocyte Proliferation and Engineered Cartilage Formation in Vitro

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Xia Liu

2014-01-01

Full Text Available The goal of this study is to determine the effects of Insulin-Transferrin-Selenium (ITS on proliferation of auricular chondrocytes and formation of engineered cartilage in vitro. Pig auricular monolayer chondrocytes and chondrocyte pellets were cultured in media containing 1% ITS at different concentrations of fetal bovine serum (FBS, 10%, 6%, 2%, 0%, or 10% FBS alone as a control for four weeks. Parameters including cell proliferation in monolayer, wet weight, collagen type I/II/X (Col I, II, X and glycosaminoglycan (GAG expression, GAG content of pellets and gene expression associated with cartilage formation/dedifferentiation (lost cartilage phenotype/hypertrophy within the chondrocyte pellets were assessed. The results showed that chondrocytes proliferation rates increased when FBS concentrations increased (2%, 6%, 10% FBS in ITS supplemented groups. In addition, 1% ITS plus 10% FBS significantly promoted cell proliferation than 10% FBS alone. No chondrocytes grew in ITS alone medium. 1% ITS plus 10% FBS enhanced cartilage formation in terms of size, wet weight, cartilage specific matrices, and homogeneity, compared to 10% FBS alone group. Furthermore, ITS prevented engineered cartilage from dedifferentiation (i.e., higher index of Col II/Col I mRNA expression and expression of aggrecan and hypertrophy (i.e., lower mRNA expression of Col X and MMP13. In conclusion, our results indicated that ITS efficiently enhanced auricular chondrocytes proliferation, retained chondrogenic phenotypes, and promoted engineered cartilage formation when combined with FBS, which is potentially used as key supplementation in auricular chondrocytes and engineered cartilage culture.

Sensitivity of docetaxel-resistant MCF-7 breast cancer cells to microtubule-destabilizing agents including vinca alkaloids and colchicine-site binding agents.

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Richard C Wang

Full Text Available One of the main reasons for disease recurrence in the curative breast cancer treatment setting is the development of drug resistance. Microtubule targeted agents (MTAs are among the most commonly used drugs for the treatment of breaset cancer and therefore overcoming taxane resistance is of primary clinical importance. Our group has previously demonstrated that the microtubule dynamics of docetaxel-resistant MCF-7TXT cells are insensitivity to docetaxel due to the distinct expression profiles of β-tubulin isotypes in addition to the high expression of p-glycoprotein (ABCB1. In the present investigation we examined whether taxane-resistant breast cancer cells are more sensitive to microtubule destabilizing agents including vinca alkaloids and colchicine-site binding agents (CSBAs than the non-resistant cells.Two isogenic MCF-7 breast cancer cell lines were selected for resistance to docetaxel (MCF-7TXT and the wild type parental cell line (MCF-7CC to examine if taxane-resistant breast cancer cells are sensitive to microtubule-destabilizing agents including vinca alkaloids and CSBAs. Cytotoxicity assays, immunoblotting, indirect immunofluorescence and live imaging were used to study drug resistance, apoptosis, mitotic arrest, microtubule formation, and microtubule dynamics.MCF-7TXT cells were demonstrated to be cross resistant to vinca alkaloids, but were more sensitive to treatment with colchicine compared to parental non-resistant MCF-7CC cells. Cytotoxicity assays indicated that the IC50 of MCF-7TXT cell to vinorelbine and vinblastine was more than 6 and 3 times higher, respectively, than that of MCF-7CC cells. By contrast, the IC50 of MCF-7TXT cell for colchincine was 4 times lower than that of MCF-7CC cells. Indirect immunofluorescence showed that all MTAs induced the disorganization of microtubules and the chromatin morphology and interestingly each with a unique pattern. In terms of microtubule and chromain morphology, MCF-7TXT cells were

Blastema cells derived from New Zealand white rabbit's pinna carry stemness properties as shown by differentiation into insulin producing, neural, and osteogenic lineages representing three embryonic germ layers.

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Saeinasab, Morvarid; Matin, Maryam M; Rassouli, Fatemeh B; Bahrami, Ahmad Reza

2016-05-01

Stem cells (SCs) are known as undifferentiated cells with self-renewal and differentiation capacities. Regeneration is a phenomenon that occurs in a limited number of animals after injury, during which blastema tissue is formed. It has been hypothesized that upon injury, the dedifferentiation of surrounding tissues leads into the appearance of cells with SC characteristics. In present study, stem-like cells (SLCs) were obtained from regenerating tissue of New Zealand white rabbit's pinna and their stemness properties were examined by their capacity to differentiate toward insulin producing cells (IPCs), as well as neural and osteogenic lineages. Differentiation was induced by culture of SLCs in defined medium, and cell fates were monitored by specific staining, RT-PCR and flow cytometry assays. Our results revealed that dithizone positive cells, which represent IPCs, and islet-like structures appeared 1 week after induction of SLCs, and this observation was confirmed by the elevated expression of Ins, Pax6 and Glut4 at mRNA level. Furthermore, SLCs were able to express neural markers as early as 1 week after retinoic acid treatment. Finally, SLCs were able to differentiate into osteogenic lineage, as confirmed by Alizarin Red S staining and RT-PCR studies. In conclusion, SLCs, which could successfully differentiate into cells derived from all three germ layers, can be considered as a valuable model to study developmental biology and regenerative medicine.

Endothelin B Receptors on Primary Chicken Müller Cells and the Human MIO-M1 Müller Cell Line Activate ERK Signaling via Transactivation of Epidermal Growth Factor Receptors.

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Mohammad Harun-Or-Rashid

Full Text Available Injury to the eye or retina triggers Müller cells, the major glia cell of the retina, to dedifferentiate and proliferate. In some species they attain retinal progenitor properties and have the capacity to generate new neurons. The epidermal growth factor receptor (EGFR system and extracellular signal-regulated kinase (ERK signaling are key regulators of these processes in Müller cells. The extracellular signals that modulate and control these processes are not fully understood. In this work we studied whether endothelin receptor signaling can activate EGFR and ERK signaling in Müller cells. Endothelin expression is robustly upregulated at retinal injury and endothelin receptors have been shown to transactivate EGFRs in other cell types. We analyzed the endothelin signaling system in chicken retina and cultured primary chicken Müller cells as well as the human Müller cell line MIO-M1. The Müller cells were stimulated with receptor agonists and treated with specific blockers to key enzymes in the signaling pathway or with siRNAs. We focused on endothelin receptor mediated transactivation of EGFRs by using western blot analysis, quantitative reverse transcriptase PCR and immunocytochemistry. The results showed that chicken Müller cells and the human Müller cell line MIO-M1 express endothelin receptor B. Stimulation by the endothelin receptor B agonist IRL1620 triggered phosphorylation of ERK1/2 and autophosphorylation of (Y1173 EGFR. The effects could be blocked by Src-kinase inhibitors (PP1, PP2, EGFR-inhibitor (AG1478, EGFR-siRNA and by inhibitors to extracellular matrix metalloproteinases (GM6001, consistent with a Src-kinase mediated endothelin receptor response that engage ligand-dependent and ligand-independent EGFR activation. Our data suggest a mechanism for how injury-induced endothelins, produced in the retina, may modulate the Müller cell responses by Src-mediated transactivation of EGFRs. The data give support to a view in

AR42J-B-13 cell: An expandable progenitor to generate an unlimited supply of functional hepatocytes

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Wallace, Karen; Fairhall, Emma A.; Charlton, Keith A.; Wright, Matthew C.

2010-01-01

Hepatocytes are the preparation of choice for Toxicological research in vitro. However, despite the fact that hepatocytes proliferate in vivo during liver regeneration, they are resistant to proliferation in vitro, do not tolerate sub-culture and tend to enter a de-differentiation program that results in a loss of hepatic function. These limitations have resulted in the search for expandable rodent and human cells capable of being directed to differentiate into functional hepatocytes. Research with stem cells suggests that it may be possible to provide the research community with hepatocytes in vitro although to date, significant challenges remain, notably generating a sufficiently pure population of hepatocytes with a quantitative functionality comparable with hepatocytes. This paper reviews work with the AR42J-B-13 (B-13) cell line. The B-13 cell was cloned from the rodent AR42J pancreatic cell line, express genes associated with pancreatic acinar cells and readily proliferates in simple culture media. When exposed to glucocorticoid, 75-85% of the cells trans-differentiate into hepatocyte-like (B-13/H) cells functioning at a level quantitatively similar to freshly isolated rat hepatocytes (with the remaining cells retaining the B-13 phenotype). Trans-differentiation of pancreatic acinar cells also appears to occur in vivo in rats treated with glucocorticoid; in mice with elevated circulating glucocorticoid and in humans treated for long periods with glucocorticoid. The B-13 response to glucocorticoid therefore appears to be related to a real pathophysiological response of a pancreatic cell to glucocorticoid. An understanding of how this process occurs and if it can be generated or engineered in human cells would result in a cell line with the ability to generate an unlimited supply of functional human hepatocytes in a cost effective manner.

Transforming growth factor: beta signaling is essential for limb regeneration in axolotls.

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Mathieu Lévesque

2007-11-01

Full Text Available Axolotls (urodele amphibians have the unique ability, among vertebrates, to perfectly regenerate many parts of their body including limbs, tail, jaw and spinal cord following injury or amputation. The axolotl limb is the most widely used structure as an experimental model to study tissue regeneration. The process is well characterized, requiring multiple cellular and molecular mechanisms. The preparation phase represents the first part of the regeneration process which includes wound healing, cellular migration, dedifferentiation and proliferation. The redevelopment phase represents the second part when dedifferentiated cells stop proliferating and redifferentiate to give rise to all missing structures. In the axolotl, when a limb is amputated, the missing or wounded part is regenerated perfectly without scar formation between the stump and the regenerated structure. Multiple authors have recently highlighted the similarities between the early phases of mammalian wound healing and urodele limb regeneration. In mammals, one very important family of growth factors implicated in the control of almost all aspects of wound healing is the transforming growth factor-beta family (TGF-beta. In the present study, the full length sequence of the axolotl TGF-beta1 cDNA was isolated. The spatio-temporal expression pattern of TGF-beta1 in regenerating limbs shows that this gene is up-regulated during the preparation phase of regeneration. Our results also demonstrate the presence of multiple components of the TGF-beta signaling machinery in axolotl cells. By using a specific pharmacological inhibitor of TGF-beta type I receptor, SB-431542, we show that TGF-beta signaling is required for axolotl limb regeneration. Treatment of regenerating limbs with SB-431542 reveals that cellular proliferation during limb regeneration as well as the expression of genes directly dependent on TGF-beta signaling are down-regulated. These data directly implicate TGF

Highly active antiretroviral therapy including protease inhibitors does not confer a unique CD4 cell benefit. The AVANTI and INCAS Study Groups.

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2000-07-07

To determine if triple combination therapy, particularly including HIV protease inhibitors (PI), confers an unique immunological benefit that is independent of reductions of plasma viral load (pVL). The correlation between changes from baseline in CD4 cell count and pVL was examined at all time points up to 52 weeks in three randomized clinical trials (AVANTI-2, AVANTI-3 and INCAS) that compared dual nucleoside therapy with triple combination therapy. Individual pVL and CD4 cell counts changes from baseline were entered into multivariate linear regression models for patients receiving double therapy and for those receiving triple therapy including a PI and/or a non-nucleoside reverse transcriptase inhibitor (NNRTI), and the null hypothesis was tested. After 52 weeks of therapy, the relationship between changes from baseline CD4 cell count and pVL was independent of whether patients were assigned double or triple therapy (P = 0.23 and 0.69 for intercept and slope, respectively), or whether patients were assigned triple therapy including a PI or triple therapy including an NNRTI (P = 0.92 and 0.95, respectively). Less than 5% of patients ever had 'discordant' increases in both CD4 cell count and pVL compared with baseline, and this proportion was unrelated to the class of therapy used. 'Discordant' decreases from baseline in both parameters were observed in up to 35% of individuals. The correlation between pVL and CD4 cell count changes from baseline improved over time on therapy, regardless of the therapeutic regimen involved. The data provide no evidence for a CD4 cell count benefit of highly active antiretroviral therapy (HAART) unique to triple therapy or PI-containing regimens.

Bioenergetic profile of human coronary artery smooth muscle cells and effect of metabolic intervention.

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Mingming Yang

Full Text Available Bioenergetics of artery smooth muscle cells is critical in cardiovascular health and disease. An acute rise in metabolic demand causes vasodilation in systemic circulation while a chronic shift in bioenergetic profile may lead to vascular diseases. A decrease in intracellular ATP level may trigger physiological responses while dedifferentiation of contractile smooth muscle cells to a proliferative and migratory phenotype is often observed during pathological processes. Although it is now possible to dissect multiple building blocks of bioenergetic components quantitatively, detailed cellular bioenergetics of artery smooth muscle cells is still largely unknown. Thus, we profiled cellular bioenergetics of human coronary artery smooth muscle cells and effects of metabolic intervention. Mitochondria and glycolysis stress tests utilizing Seahorse technology revealed that mitochondrial oxidative phosphorylation accounted for 54.5% of ATP production at rest with the remaining 45.5% due to glycolysis. Stress tests also showed that oxidative phosphorylation and glycolysis can increase to a maximum of 3.5 fold and 1.25 fold, respectively, indicating that the former has a high reserve capacity. Analysis of bioenergetic profile indicated that aging cells have lower resting oxidative phosphorylation and reduced reserve capacity. Intracellular ATP level of a single cell was estimated to be over 1.1 mM. Application of metabolic modulators caused significant changes in mitochondria membrane potential, intracellular ATP level and ATP:ADP ratio. The detailed breakdown of cellular bioenergetics showed that proliferating human coronary artery smooth muscle cells rely more or less equally on oxidative phosphorylation and glycolysis at rest. These cells have high respiratory reserve capacity and low glycolysis reserve capacity. Metabolic intervention influences both intracellular ATP concentration and ATP:ADP ratio, where subtler changes may be detected by the latter.

Bone morphogenetic protein-induced MSX1 and MSX2 inhibit myocardin-dependent smooth muscle gene transcription.

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Hayashi, Ken'ichiro; Nakamura, Seiji; Nishida, Wataru; Sobue, Kenji

2006-12-01

During the onset and progression of atherosclerosis, the vascular smooth muscle cell (VSMC) phenotype changes from differentiated to dedifferentiated, and in some cases, this change is accompanied by osteogenic transition, resulting in vascular calcification. One characteristic of dedifferentiated VSMCs is the down-regulation of smooth muscle cell (SMC) marker gene expression. Bone morphogenetic proteins (BMPs), which are involved in the induction of osteogenic gene expression, are detected in calcified vasculature. In this study, we found that the BMP2-, BMP4-, and BMP6-induced expression of Msx transcription factors (Msx1 and Msx2) preceded the down-regulation of SMC marker expression in cultured differentiated VSMCs. Either Msx1 or Msx2 markedly reduced the myocardin-dependent promoter activities of SMC marker genes (SM22alpha and caldesmon). We further investigated interactions between Msx1 and myocardin/serum response factor (SRF)/CArG-box motif (cis element for SRF) using coimmunoprecipitation, gel-shift, and chromatin immunoprecipitation assays. Our results showed that Msx1 or Msx2 formed a ternary complex with SRF and myocardin and inhibited the binding of SRF or SRF/myocardin to the CArG-box motif, resulting in inhibition of their transcription.

Bone Morphogenetic Protein-Induced Msx1 and Msx2 Inhibit Myocardin-Dependent Smooth Muscle Gene Transcription▿

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Hayashi, Ken'ichiro; Nakamura, Seiji; Nishida, Wataru; Sobue, Kenji

2006-01-01

During the onset and progression of atherosclerosis, the vascular smooth muscle cell (VSMC) phenotype changes from differentiated to dedifferentiated, and in some cases, this change is accompanied by osteogenic transition, resulting in vascular calcification. One characteristic of dedifferentiated VSMCs is the down-regulation of smooth muscle cell (SMC) marker gene expression. Bone morphogenetic proteins (BMPs), which are involved in the induction of osteogenic gene expression, are detected in calcified vasculature. In this study, we found that the BMP2-, BMP4-, and BMP6-induced expression of Msx transcription factors (Msx1 and Msx2) preceded the down-regulation of SMC marker expression in cultured differentiated VSMCs. Either Msx1 or Msx2 markedly reduced the myocardin-dependent promoter activities of SMC marker genes (SM22α and caldesmon). We further investigated interactions between Msx1 and myocardin/serum response factor (SRF)/CArG-box motif (cis element for SRF) using coimmunoprecipitation, gel-shift, and chromatin immunoprecipitation assays. Our results showed that Msx1 or Msx2 formed a ternary complex with SRF and myocardin and inhibited the binding of SRF or SRF/myocardin to the CArG-box motif, resulting in inhibition of their transcription. PMID:17030628

Impact of cell lines included in enterovirus isolation protocol on perception of nonpolio enterovirus species C diversity.

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Adeniji, Johnson Adekunle; Faleye, Temitope Oluwasegun Cephas

2014-10-01

There has been under-reporting of nonpolio enterovirus species Cs (NPESCs) in Nigeria despite the fact that most isolates recovered from the Nigerian vaccine derived poliovirus serotype 2 (VDPV2) outbreak were recombinants with nonstructural region of NPESC origin. It has been suggested that cell lines included in enterovirus isolation protocols might account for this phenomenon and this study examined this suggestion. Fifteen environmental samples concentrated previously and analysed using L20B and RD cell lines as part of the poliovirus environmental surveillance (ES) program in Nigeria were randomly selected and inoculated into two cell lines (MCF-7 and LLC-MK2). Isolates were identified as enteroviruses and species C members using different RT-PCR assays, culture in L20B cell line and sequencing of partial VP1. Forty-eight (48) isolates were recovered from the 15 samples, 47 (97.9%) of which were enteroviruses. Of the enteroviruses, 32 (68.1%) belonged to enterovirus species C (EC) of which 19 (40.4%) were polioviruses and 13 (27.7%) were NPESC members. All 13 NPESC isolates were recovered on MCF-7. Results of the study show that NPESCs are circulating in Nigeria and their under-reporting was due to the combination of cell lines used for enterovirus isolation in previous reports. Copyright © 2014 Elsevier B.V. All rights reserved.

Peculiarities of intestine injuries in case of internal and external irradiation: a morphometric study

International Nuclear Information System (INIS)

Ponomareva, T.V.

1988-01-01

It is shown that sterological cell parameters and indexes of their interaction may serve as an important characteristic of tissue postirradiation recovery quality permitting to give a precise quantitative characteristic of cell differentiation and dedifferentiation. It is established that enterocyte maturation is sharphy broken under irradiation. Population delamination into sublines differing in cell size takes place. The number of these cells depends on radiation doses. The most labile cell componenet is cell nucleoli. The cell differentiation breakage is more pronounced in case of internal irradiation (Ce 144 ) and in combined radiation effect. A degree of cell differentiation breakage depends on peroxidation level. The obtained data can be used in developing and evaluating radioprotective substances

Stromelysin-3 over-expression enhances tumourigenesis in MCF-7 and MDA-MB-231 breast cancer cell lines: involvement of the IGF-1 signalling pathway

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Mennerich Detlev

2007-01-01

Full Text Available Abstract Background Stromelysin-3 (ST-3 is over-expressed in the majority of human carcinomas including breast carcinoma. Due to its known effect in promoting tumour formation, but its impeding effect on metastasis, a dual role of ST-3 in tumour progression, depending on the cellular grade of dedifferentiation, was hypothesized. Methods The present study was designed to investigate the influence of ST-3 in vivo and in vitro on the oestrogen-dependent, non-invasive MCF-7 breast carcinoma cell line as well as on the oestrogen-independent, invasive MDA-MB-231 breast carcinoma cell line. Therefore an orthotopic human xenograft tumour model in nude mice, as well as a 3D matrigel cell culture system, were employed. Results Using both in vitro and in vivo techniques, we have demonstrated that over-expression of ST-3 in MCF-7 and MDA-MB-231 cells leads to both increased cell numbers and tumour volumes. This observation was dependent upon the presence of growth factors. In particular, the enhanced proliferative capacity was in MCF-7/ST-3 completely and in MDA-MB-231/ST-3 cells partially dependent on the IGF-1 signalling pathway. Microarray analysis of ST-3 over-expressing cells revealed that in addition to cell proliferation, further biological processes seemed to be affected, such as cell motility and stress response. The MAPK-pathway as well as the Wnt and PI3-kinase pathways, appear to also play a potential role. Furthermore, we have demonstrated that breast cancer cell lines of different differentiation status, as well as the non-tumourigenic cell line MCF-10A, have a comparable capability to induce endogenous ST-3 expression in fibroblasts. Conclusion These data reveal that ST-3 is capable of enhancing tumourigenesis in highly differentiated "early stage" breast cancer cell lines as well as in further progressed breast cancer cell lines that have already undergone epithelial-mesenchymal transition. We propose that ST-3 induction in tumour

Stromelysin-3 over-expression enhances tumourigenesis in MCF-7 and MDA-MB-231 breast cancer cell lines: involvement of the IGF-1 signalling pathway

International Nuclear Information System (INIS)

Kasper, Grit; Lehmann, Kerstin E; Reule, Matthias; Tschirschmann, Miriam; Dankert, Niels; Stout-Weider, Karen; Lauster, Roland; Schrock, Evelin; Mennerich, Detlev; Duda, Georg N

2007-01-01

Stromelysin-3 (ST-3) is over-expressed in the majority of human carcinomas including breast carcinoma. Due to its known effect in promoting tumour formation, but its impeding effect on metastasis, a dual role of ST-3 in tumour progression, depending on the cellular grade of dedifferentiation, was hypothesized. The present study was designed to investigate the influence of ST-3 in vivo and in vitro on the oestrogen-dependent, non-invasive MCF-7 breast carcinoma cell line as well as on the oestrogen-independent, invasive MDA-MB-231 breast carcinoma cell line. Therefore an orthotopic human xenograft tumour model in nude mice, as well as a 3D matrigel cell culture system, were employed. Using both in vitro and in vivo techniques, we have demonstrated that over-expression of ST-3 in MCF-7 and MDA-MB-231 cells leads to both increased cell numbers and tumour volumes. This observation was dependent upon the presence of growth factors. In particular, the enhanced proliferative capacity was in MCF-7/ST-3 completely and in MDA-MB-231/ST-3 cells partially dependent on the IGF-1 signalling pathway. Microarray analysis of ST-3 over-expressing cells revealed that in addition to cell proliferation, further biological processes seemed to be affected, such as cell motility and stress response. The MAPK-pathway as well as the Wnt and PI3-kinase pathways, appear to also play a potential role. Furthermore, we have demonstrated that breast cancer cell lines of different differentiation status, as well as the non-tumourigenic cell line MCF-10A, have a comparable capability to induce endogenous ST-3 expression in fibroblasts. These data reveal that ST-3 is capable of enhancing tumourigenesis in highly differentiated 'early stage' breast cancer cell lines as well as in further progressed breast cancer cell lines that have already undergone epithelial-mesenchymal transition. We propose that ST-3 induction in tumour fibroblasts leads to the stimulation of the IGF-1R pathway in

The role of hepatocyte nuclear factor 4-alpha in perfluorooctanoic acid- and perfluorooctanesulfonic acid-induced hepatocellular dysfunction

Energy Technology Data Exchange (ETDEWEB)

Beggs, Kevin M., E-mail: kbeggs2@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); McGreal, Steven R., E-mail: smcgreal@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); McCarthy, Alex [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); Gunewardena, Sumedha, E-mail: sgunewardena@kumc.edu [Department of Molecular and Integrative Physiology, University of Kansas Medical Center, 3901 Rainbow Blvd, 2027 HLSIC, Kansas City, KS 66160 (United States); Lampe, Jed N., E-mail: jlampe@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States); Lau, Christoper, E-mail: lau.christopher@epa.gov [Developmental Toxicology Branch, Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Apte, Udayan, E-mail: uapte@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd, 4052 HLSIC, Kansas City, KS 66160 (United States)

2016-08-01

Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), chemicals present in a multitude of consumer products, are persistent organic pollutants. Both compounds induce hepatotoxic effects in rodents, including steatosis, hepatomegaly and liver cancer. The mechanisms of PFOA- and PFOS-induced hepatic dysfunction are not completely understood. We present evidence that PFOA and PFOS induce their hepatic effects via targeting hepatocyte nuclear factor 4-alpha (HNF4α). Human hepatocytes treated with PFOA and PFOS at a concentration relevant to occupational exposure caused a decrease in HNF4α protein without affecting HNF4α mRNA or causing cell death. RNA sequencing analysis combined with Ingenuity Pathway Analysis of global gene expression changes in human hepatocytes treated with PFOA or PFOS indicated alterations in the expression of genes involved in lipid metabolism and tumorigenesis, several of which are regulated by HNF4α. Further investigation of specific HNF4α target gene expression revealed that PFOA and PFOS could promote cellular dedifferentiation and increase cell proliferation by down regulating positive targets (differentiation genes such as CYP7A1) and inducing negative targets of HNF4α (pro-mitogenic genes such as CCND1). Furthermore, in silico docking simulations indicated that PFOA and PFOS could directly interact with HNF4α in a similar manner to endogenous fatty acids. Collectively, these results highlight HNF4α degradation as novel mechanism of PFOA and PFOS-mediated steatosis and tumorigenesis in human livers. - Highlights: • PFOA and PFOS cause decreased HNF4α protein expression in human hepatocytes. • PFOA and PFOS promote changes associated with lipid metabolism and carcinogenesis. • PFOA and PFOS induced changes in gene expression associated with cellular dedifferentiation. • PFOA and PFOS induce expression of Nanog, a transcription factor involved in stem cell development.

Pediatric medulloblastoma xenografts including molecular subgroup 3 and CD133+ and CD15+ cells are sensitive to killing by oncolytic herpes simplex viruses.

Science.gov (United States)

Friedman, Gregory K; Moore, Blake P; Nan, Li; Kelly, Virginia M; Etminan, Tina; Langford, Catherine P; Xu, Hui; Han, Xiaosi; Markert, James M; Beierle, Elizabeth A; Gillespie, G Yancey

2016-02-01

Childhood medulloblastoma is associated with significant morbidity and mortality that is compounded by neurotoxicity for the developing brain caused by current therapies, including surgery, craniospinal radiation, and chemotherapy. Innate therapeutic resistance of some aggressive pediatric medulloblastoma has been attributed to a subpopulation of cells, termed cancer-initiating cells or cancer stemlike cells (CSCs), marked by the surface protein CD133 or CD15. Brain tumors characteristically contain areas of pathophysiologic hypoxia, which has been shown to drive the CSC phenotype leading to heightened invasiveness, angiogenesis, and metastasis. Novel therapies that target medulloblastoma CSCs are needed to improve outcomes and decrease toxicity. We hypothesized that oncolytic engineered herpes simplex virus (oHSV) therapy could effectively infect and kill pediatric medulloblastoma cells, including CSCs marked by CD133 or CD15. Using 4 human pediatric medulloblastoma xenografts, including 3 molecular subgroup 3 tumors, which portend worse patient outcomes, we determined the expression of CD133, CD15, and the primary HSV-1 entry molecule nectin-1 (CD111) by fluorescence activated cell sorting (FACS) analysis. Infectability and cytotoxicity of clinically relevant oHSVs (G207 and M002) were determined in vitro and in vivo by FACS, immunofluorescent staining, cytotoxicity assays, and murine survival studies. We demonstrate that hypoxia increased the CD133+ cell fraction, while having the opposite effect on CD15 expression. We established that all 4 xenografts, including the CSCs, expressed CD111 and were highly sensitive to killing by G207 or M002. Pediatric medulloblastoma, including Group 3 tumors, may be an excellent target for oHSV virotherapy, and a clinical trial in medulloblastoma is warranted. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Bacterial Cellulose Shifts Transcriptome and Proteome of Cultured Endothelial Cells Towards Native Differentiation.

Science.gov (United States)

Feil, Gerhard; Horres, Ralf; Schulte, Julia; Mack, Andreas F; Petzoldt, Svenja; Arnold, Caroline; Meng, Chen; Jost, Lukas; Boxleitner, Jochen; Kiessling-Wolf, Nicole; Serbest, Ender; Helm, Dominic; Kuster, Bernhard; Hartmann, Isabel; Korff, Thomas; Hahne, Hannes

2017-09-01

Preserving the native phenotype of primary cells in vitro is a complex challenge. Recently, hydrogel-based cellular matrices have evolved as alternatives to conventional cell culture techniques. We developed a bacterial cellulose-based aqueous gel-like biomaterial, dubbed Xellulin, which mimics a cellular microenvironment and seems to maintain the native phenotype of cultured and primary cells. When applied to human umbilical vein endothelial cells (HUVEC), it allowed the continuous cultivation of cell monolayers for more than one year without degradation or dedifferentiation. To investigate the impact of Xellulin on the endothelial cell phenotype in detail, we applied quantitative transcriptomics and proteomics and compared the molecular makeup of native HUVEC, HUVEC on collagen-coated Xellulin and collagen-coated cell culture plastic (polystyrene).Statistical analysis of 12,475 transcripts and 7831 proteins unveiled massive quantitative differences of the compared transcriptomes and proteomes. K -means clustering followed by network analysis showed that HUVEC on plastic upregulate transcripts and proteins controlling proliferation, cell cycle and protein biosynthesis. In contrast, HUVEC on Xellulin maintained, by and large, the expression levels of genes supporting their native biological functions and signaling networks such as integrin, receptor tyrosine kinase MAP/ERK and PI3K signaling pathways, while decreasing the expression of proliferation associated proteins. Moreover, CD34-an endothelial cell differentiation marker usually lost early during cell culture - was re-expressed within 2 weeks on Xellulin but not on plastic. And HUVEC on Xellulin showed a significantly stronger functional responsiveness to a prototypic pro-inflammatory stimulus than HUVEC on plastic.Taken together, this is one of the most comprehensive transcriptomic and proteomic studies of native and propagated HUVEC, which underscores the importance of the morphology of the cellular

Platelet lysate activates quiescent cell proliferation and reprogramming in human articular cartilage: Involvement of hypoxia inducible factor 1.

Science.gov (United States)

Nguyen, Van Thi; Cancedda, Ranieri; Descalzi, Fiorella

2018-03-01

The idea of rescuing the body self-repair capability lost during evolution is progressively gaining ground in regenerative medicine. In particular, growth factors and bioactive molecules derived from activated platelets emerged as promising therapeutic agents acting as trigger for repair of tissue lesions and restoration of tissue functions. Aim of this study was to assess the potential of a platelet lysate (PL) for human articular cartilage repair considering its activity on progenitor cells and differentiated chondrocytes. PL induced the re-entry in the cell cycle of confluent, growth-arrested dedifferentiated/progenitor cartilage cells. In a cartilage permissive culture environment, differentiated cells also resumed proliferation after exposure to PL. These findings correlated with an up-regulation of the proliferation/survival pathways ERKs and Akt and with an induction of cyclin D1. In short- and long-term cultures of articular cartilage explants, we observed a release of proliferating chondroprogenitors able to differentiate and form an "in vitro" tissue with properties of healthy articular cartilage. Moreover, in cultured cartilage cells, PL induced a hypoxia-inducible factor (HIF-1) alpha increase, its nuclear relocation and the binding to HIF-1 responsive elements. These events were possibly related to the cell proliferation because the HIF-1 inhibitor acriflavine inhibited HIF-1 binding to HIF-1 responsive elements and cell proliferation. Our study demonstrates that PL induces quiescent cartilage cell activation and proliferation leading to new cartilage formation, identifies PL activated pathways playing a role in these processes, and provides a rationale to the application of PL for therapeutic treatment of damaged articular cartilage. Copyright © 2017 John Wiley & Sons, Ltd.

Transformation Resistance in a Premature Aging Disorder Identifies a Tumor-Protective Function of BRD4

Directory of Open Access Journals (Sweden)

Patricia Fernandez

2014-10-01

Full Text Available Summary: Advanced age and DNA damage accumulation are prominent risk factors for cancer. The premature aging disorder Hutchinson-Gilford progeria syndrome (HGPS provides a unique opportunity for studying the interplay between DNA damage and aging-associated tumor mechanisms, given that HGPS patients do not develop tumors despite elevated levels of DNA damage. Here, we have used HGPS patient cells to identify a protective mechanism to oncogenesis. We find that HGPS cells are resistant to neoplastic transformation. Resistance is mediated by the bromodomain protein BRD4, which exhibits altered genome-wide binding patterns in transformation-resistant cells, leading to inhibition of oncogenic dedifferentiation. BRD4 also inhibits, albeit to a lower extent, the tumorigenic potential of transformed cells from healthy individuals. BRD4-mediated tumor protection is clinically relevant given that a BRD4 gene signature predicts positive clinical outcome in breast and lung cancer. Our results demonstrate a protective function for BRD4 and suggest tissue-specific roles for BRD4 in tumorigenesis. : The premature aging disorder Hutchinson-Gilford progeria syndrome (HGPS provides a unique tool for studying the interplay between DNA damage and aging-associated tumor mechanisms, given that HGPS patients do not develop tumors despite elevated levels of DNA damage. Using a genome-wide RNAi screen, Fernandez et al. now identify the bromodomain protein BRD4 as a mediator of the oncogenic resistance of HGPS cells. This tumor-protective function of BRD4 involves inhibition of oncogenic dedifferentiation and is also active in non-HGPS cells in a tissue-specific manner.

Myocardial regeneration in adriamycin cardiomyopathy by nuclear expression of GLP1 using ultrasound targeted microbubble destruction

Energy Technology Data Exchange (ETDEWEB)

Chen, Shuyuan [Baylor Research Institute, Baylor University Medical Center, 3812 Elm Street, Dallas, TX (United States); Chen, Jiaxi [The University of Texas Southwestern Medical Center at Dallas, Medical School, 5235 Harry Hine Blvd., Dallas, TX (United States); Huang, Pintong [Department of Ultrasonography, The 2nd Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, Zhejiang Province (China); Meng, Xing-Li; Clayton, Sandra; Shen, Jin-Song [Baylor Research Institute, Baylor University Medical Center, 3812 Elm Street, Dallas, TX (United States); Grayburn, Paul A., E-mail: paulgr@baylorhealth.edu [Baylor Research Institute, Baylor University Medical Center, 3812 Elm Street, Dallas, TX (United States); Department of Internal Medicine, Division of Cardiology, Baylor Heart and Vascular Institute, Baylor University Medical Center, 621 N. Hall St, Suite H030, Dallas, TX (United States)

2015-03-20

Recently GLP-1 was found to have cardioprotective effects independent of those attributable to tight glycemic control. Methods and results: We employed ultrasound targeted microbubble destruction (UTMD) to deliver piggybac transposon plasmids encoding the GLP-1 gene with a nuclear localizing signal to rat hearts with adriamycin cardiomyopathy. After a single UTMD treatment, overexpression of transgenic GLP-1 was found in nuclei of rat heart cells with evidence that transfected cardiac cells had undergone proliferation. UTMD-GLP-1 gene therapy restored LV mass, fractional shortening index, and LV posterior wall diameter to nearly normal. Nuclear overexpression of GLP-1 by inducing phosphorylation of FoxO1-S256 and translocation of FoxO1 from the nucleus to the cytoplasm significantly inactivated FoxO1 and activated the expression of cyclin D1 in nuclei of cardiac muscle cells. Reversal of adriamycin cardiomyopathy appeared to be mediated by dedifferentiation and proliferation of nuclear FoxO1-positive cardiac muscle cells with evidence of embryonic stem cell markers (OCT4, Nanog, SOX2 and c-kit), cardiac early differentiation markers (NKX2.5 and ISL-1) and cellular proliferation markers (BrdU and PHH3) after UTMD with GLP-1 gene therapy. Conclusions: Intranuclear myocardial delivery of the GLP-1gene can reverse established adriamycin cardiomyopathy by stimulating myocardial regeneration. - Highlights: • The activation of nuclear FoxO1 in cardiac muscle cells associated with adriamycin cardiomyopathy. • Myocardial nuclear GLP-1 stimulates myocardial regeneration and reverses adriamycin cardiomyopathy. • The process of myocardial regeneration associated with dedifferentiation and proliferation.

Myocardial regeneration in adriamycin cardiomyopathy by nuclear expression of GLP1 using ultrasound targeted microbubble destruction

International Nuclear Information System (INIS)

Chen, Shuyuan; Chen, Jiaxi; Huang, Pintong; Meng, Xing-Li; Clayton, Sandra; Shen, Jin-Song; Grayburn, Paul A.

2015-01-01

Recently GLP-1 was found to have cardioprotective effects independent of those attributable to tight glycemic control. Methods and results: We employed ultrasound targeted microbubble destruction (UTMD) to deliver piggybac transposon plasmids encoding the GLP-1 gene with a nuclear localizing signal to rat hearts with adriamycin cardiomyopathy. After a single UTMD treatment, overexpression of transgenic GLP-1 was found in nuclei of rat heart cells with evidence that transfected cardiac cells had undergone proliferation. UTMD-GLP-1 gene therapy restored LV mass, fractional shortening index, and LV posterior wall diameter to nearly normal. Nuclear overexpression of GLP-1 by inducing phosphorylation of FoxO1-S256 and translocation of FoxO1 from the nucleus to the cytoplasm significantly inactivated FoxO1 and activated the expression of cyclin D1 in nuclei of cardiac muscle cells. Reversal of adriamycin cardiomyopathy appeared to be mediated by dedifferentiation and proliferation of nuclear FoxO1-positive cardiac muscle cells with evidence of embryonic stem cell markers (OCT4, Nanog, SOX2 and c-kit), cardiac early differentiation markers (NKX2.5 and ISL-1) and cellular proliferation markers (BrdU and PHH3) after UTMD with GLP-1 gene therapy. Conclusions: Intranuclear myocardial delivery of the GLP-1gene can reverse established adriamycin cardiomyopathy by stimulating myocardial regeneration. - Highlights: • The activation of nuclear FoxO1 in cardiac muscle cells associated with adriamycin cardiomyopathy. • Myocardial nuclear GLP-1 stimulates myocardial regeneration and reverses adriamycin cardiomyopathy. • The process of myocardial regeneration associated with dedifferentiation and proliferation

The mast cell integrates the splanchnic and systemic inflammatory response in portal hypertension

Directory of Open Access Journals (Sweden)

Arias Jorge-Luis

2007-09-01

Full Text Available Abstract Portal hypertension is a clinical syndrome that is difficult to study in an isolated manner since it is always associated with a greater or lesser degree of liver functional impairment. The aim of this review is to integrate the complications related to chronic liver disease by using both, the array of mast cell functions and mediators, since they possibly are involved in the pathophysiological mechanisms of these complications. The portal vein ligated rat is the experimental model most widely used to study this syndrome and it has been considered that a systemic inflammatory response is produced. This response is mediated among other inflammatory cells by mast cells and it evolves in three linked pathological functional systems. The nervous functional system presents ischemia-reperfusion and edema (oxidative stress and would be responsible for hyperdynamic circulation; the immune functional system causes tissue infiltration by inflammatory cells, particularly mast cells and bacteria (enzymatic stress and the endocrine functional system presents endothelial proliferation (antioxidative and antienzymatic stress and angiogenesis. Mast cells could develop a key role in the expression of these three phenotypes because their mediators have the ability to produce all the aforementioned alterations, both at the splanchnic level (portal hypertensive enteropathy, mesenteric adenitis, liver steatosis and the systemic level (portal hypertensive encephalopathy. This hypothetical splanchnic and systemic inflammatory response would be aggravated during the progression of the chronic liver disease, since the antioxidant ability of the body decreases. Thus, a critical state is produced, in which the appearance of noxious factors would favor the development of a dedifferentiation process protagonized by the nervous functional system. This system rapidly induces an ischemia-reperfusion phenotype with hydration and salinization of the body (hepatorenal

Reprogramming human A375 amelanotic melanoma cells by catalase overexpression: Reversion or promotion of malignancy by inducing melanogenesis or metastasis

Science.gov (United States)

Bracalente, Candelaria; Salguero, Noelia; Notcovich, Cintia; Müller, Carolina B.; da Motta, Leonardo L.; Klamt, Fabio; Ibañez, Irene L.; Durán, Hebe

2016-01-01

Advanced melanoma is the most aggressive form of skin cancer. It is highly metastatic and dysfunctional in melanogenesis; two processes that are induced by H2O2. This work presents a melanoma cell model with low levels of H2O2 induced by catalase overexpression to study differentiation/dedifferentiation processes. Three clones (A7, C10 and G10) of human A375 amelanotic melanoma cells with quite distinct phenotypes were obtained. These clones faced H2O2 scavenging by two main strategies. One developed by clone G10 where ROS increased. This resulted in G10 migration and metastasis associated with the increased of cofilin-1 and CAP1. The other strategy was observed in clone A7 and C10, where ROS levels were maintained reversing malignant features. Particularly, C10 was not tumorigenic, while A7 reversed the amelanotic phenotype by increasing melanin content and melanocytic differentiation markers. These clones allowed the study of potential differentiation and migration markers and its association with ROS levels in vitro and in vivo, providing a new melanoma model with different degree of malignancy. PMID:27206672

Inferring time derivatives including cell growth rates using Gaussian processes

Science.gov (United States)

Swain, Peter S.; Stevenson, Keiran; Leary, Allen; Montano-Gutierrez, Luis F.; Clark, Ivan B. N.; Vogel, Jackie; Pilizota, Teuta

2016-12-01

Often the time derivative of a measured variable is of as much interest as the variable itself. For a growing population of biological cells, for example, the population's growth rate is typically more important than its size. Here we introduce a non-parametric method to infer first and second time derivatives as a function of time from time-series data. Our approach is based on Gaussian processes and applies to a wide range of data. In tests, the method is at least as accurate as others, but has several advantages: it estimates errors both in the inference and in any summary statistics, such as lag times, and allows interpolation with the corresponding error estimation. As illustrations, we infer growth rates of microbial cells, the rate of assembly of an amyloid fibril and both the speed and acceleration of two separating spindle pole bodies. Our algorithm should thus be broadly applicable.

Thrombin induces epithelial-mesenchymal transition and collagen production by retinal pigment epithelial cells via autocrine PDGF-receptor signaling.

Science.gov (United States)

Bastiaans, Jeroen; van Meurs, Jan C; van Holten-Neelen, Conny; Nagtzaam, Nicole M A; van Hagen, P Martin; Chambers, Rachel C; Hooijkaas, Herbert; Dik, Willem A

2013-12-19

De-differentiation of RPE cells into mesenchymal cells (epithelial-mesenchymal transition; EMT) and associated collagen production contributes to development of proliferative vitreoretinopathy (PVR). In patients with PVR, intraocular coagulation cascade activation occurs and may play an important initiating role. Therefore, we examined the effect of the coagulation proteins factor Xa and thrombin on EMT and collagen production by RPE cells. Retinal pigment epithelial cells were stimulated with factor Xa or thrombin and the effect on zonula occludens (ZO)-1, α-smooth muscle actin (α-SMA), collagen, and platelet-derived growth factor (PDGF)-B were determined by real-time quantitative-polymerase chain reaction (RQ-PCR), immunofluorescence microscopy, and HPLC and ELISA for collagen and PDGF-BB in culture supernatants, respectively. PDGF-receptor activation was determined by phosphorylation analysis and inhibition studies using the PDGF-receptor tyrosine kinase inhibitor AG1296. Thrombin reduced ZO-1 gene expression (P production of α-SMA and collagen increased. In contrast to thrombin, factor Xa hardly stimulated EMT by RPE. Thrombin clearly induced PDGF-BB production and PDGF-Rβ chain phosphorylation in RPE. Moreover, AG1296 significantly blocked the effect of thrombin on EMT and collagen production. Our findings demonstrate that thrombin is a potent inducer of EMT by RPE via autocrine activation of PDGF-receptor signaling. Coagulation cascade-induced EMT of RPE may thus contribute to the formation of fibrotic retinal membranes in PVR and should be considered as treatment target in PVR.

Outcomes of Patients with Renal Cell Carcinoma and Sarcomatoid Dedifferentiation Treated with Nephrectomy and Systemic Therapies: Comparison between the Cytokine and Targeted Therapy Eras.

Science.gov (United States)

Keskin, Sarp K; Msaouel, Pavlos; Hess, Kenneth R; Yu, Kai-Jie; Matin, Surena F; Sircar, Kanishka; Tamboli, Pheroze; Jonasch, Eric; Wood, Christopher G; Karam, Jose A; Tannir, Nizar M

2017-09-01

We studied overall survival and prognostic factors in patients with sarcomatoid renal cell carcinoma treated with nephrectomy and systemic therapy in the cytokine and targeted therapy eras. This is a retrospective study of patients with sarcomatoid renal cell carcinoma who underwent nephrectomy and received systemic therapy at our center in the cytokine era (1987 to 2005) or the targeted therapy era (2006 to 2015). Multivariate regression models were used to determine the association of covariables with survival. Of the 199 patients with sarcomatoid renal cell carcinoma 167 (83.9%) died (median overall survival 16.5 months, 95% CI 15.2-20.9). Survival of patients with clear cell histology was significantly longer vs those with nonclear cell histology (p = 0.034). Patients with synchronous metastatic disease had significantly shorter survival than patients with metachronous metastatic disease (median 12.1 vs 23.3 months, p = 0.0064). Biopsy of the primary tumor or a metastatic site could detect the presence of sarcomatoid features in only 7.5% of cases. Although a significant improvement in survival rate was observed in the first year in patients treated in the targeted therapy era (p = 0.011), this effect was attenuated at year 2, disappeared at years 3 to 5 after diagnosis and was not evident in patients with poor risk features. Patients with sarcomatoid renal cell carcinoma still have poor prognosis with no clear long-term benefit of targeted therapy. This underscores the need to develop more effective systemic therapies for these patients. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

The HPV16 E7 oncoprotein increases the expression of Oct3/4 and stemness-related genes and augments cell self-renewal

Energy Technology Data Exchange (ETDEWEB)

Organista-Nava, Jorge; Gómez-Gómez, Yazmín [Programa de Doctorado en Ciencias Biomédicas, Instituto de Fisiología Celular (IFC), Universidad Nacional Autónoma de México (UNAM), Ciudad de México 04510, México (Mexico); Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Ciudad de México 07360, México (Mexico); Ocadiz-Delgado, Rodolfo; García-Villa, Enrique [Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Ciudad de México 07360, México (Mexico); Bonilla-Delgado, José [Unidad de Investigación, Hospital Juárez de México, Ciudad de México 07760, México (Mexico); Lagunas-Martínez, Alfredo [División de Biología Molecular de Patógenos, CISEI, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México (Mexico); and others

2016-12-15

Oct3/4 is a transcription factor involved in maintenance of the pluripotency and self-renewal of stem cells. The E7 oncoprotein and 17β-estradiol (E{sub 2}) are key factors in cervical carcinogenesis. In the present study, we aimed to investigate the effect of the HPV16 E7 oncoprotein and E{sub 2} on the expression pattern of Oct3/4, Sox2, Nanog and Fgf4. We also determined whether the E7 oncoprotein is associated with cell self-renewal. The results showed that Oct3/4, Sox2, Nanog and Fgf4 were upregulated by the E7 oncoprotein in vivo and in vitro and implicate E{sub 2} in the upregulation of these factors in vivo. We also demonstrated that E7 is involved in cell self-renewal, suggesting that the HPV16 E7 oncoprotein upregulates Oct3/4, Sox2, Nanog and Fgf4 expression to maintain the self-renewal capacity of cancer stem cells. -- Graphical abstract: The HPV16 E7 oncoprotein and 17β-estradiol are involved in the upregulation of Oct3/4, Sox2, Nanog and Fgf4 expression to maintain the self-renewal ability of cancer stem cells in cervical cancer. - Highlights: •The HPV16 E7 oncoprotein enhances cellular proliferation and dedifferentiation. •The E7 oncoprotein induces stemness-related genes expression in vivo and in vitro. •The 17β-estradiol induces stemness-related genes expression in vivo. •The HPV16 E7 oncoprotein is involved in the cell self-renewal of cancer cells.

The HPV16 E7 oncoprotein increases the expression of Oct3/4 and stemness-related genes and augments cell self-renewal

International Nuclear Information System (INIS)

Organista-Nava, Jorge; Gómez-Gómez, Yazmín; Ocadiz-Delgado, Rodolfo; García-Villa, Enrique; Bonilla-Delgado, José; Lagunas-Martínez, Alfredo

2016-01-01

Oct3/4 is a transcription factor involved in maintenance of the pluripotency and self-renewal of stem cells. The E7 oncoprotein and 17β-estradiol (E 2 ) are key factors in cervical carcinogenesis. In the present study, we aimed to investigate the effect of the HPV16 E7 oncoprotein and E 2 on the expression pattern of Oct3/4, Sox2, Nanog and Fgf4. We also determined whether the E7 oncoprotein is associated with cell self-renewal. The results showed that Oct3/4, Sox2, Nanog and Fgf4 were upregulated by the E7 oncoprotein in vivo and in vitro and implicate E 2 in the upregulation of these factors in vivo. We also demonstrated that E7 is involved in cell self-renewal, suggesting that the HPV16 E7 oncoprotein upregulates Oct3/4, Sox2, Nanog and Fgf4 expression to maintain the self-renewal capacity of cancer stem cells. -- Graphical abstract: The HPV16 E7 oncoprotein and 17β-estradiol are involved in the upregulation of Oct3/4, Sox2, Nanog and Fgf4 expression to maintain the self-renewal ability of cancer stem cells in cervical cancer. - Highlights: •The HPV16 E7 oncoprotein enhances cellular proliferation and dedifferentiation. •The E7 oncoprotein induces stemness-related genes expression in vivo and in vitro. •The 17β-estradiol induces stemness-related genes expression in vivo. •The HPV16 E7 oncoprotein is involved in the cell self-renewal of cancer cells.

Etiology of thyroid cancer: a review

International Nuclear Information System (INIS)

Narkar, A.A.

1999-01-01

Thyroid cancer, although a relatively rare tumor, is the most common cancer of the endocrine glands. The identification of genetic factors important in the pathogesis of thyroid cancer could provide molecular tools for a better differential diagnosis between the different histotypes. Characterisation of mechanisms by which mutated proteins transduce mitogenic and de-differentiating signals might suggest novel therapeutic approaches for controlling cell growth and restoring thyroid differentiated functions

A comparison of the functionality and in vivo phenotypic stability of cartilaginous tissues engineered from different stem cell sources.

Science.gov (United States)

Vinardell, Tatiana; Sheehy, Eamon J; Buckley, Conor T; Kelly, Daniel J

2012-06-01

Joint-derived stem cells are a promising alternative cell source for cartilage repair therapies that may overcome many of the problems associated with the use of primary chondrocytes (CCs). The objective of this study was to compare the in vitro functionality and in vivo phenotypic stability of cartilaginous tissues engineered using bone marrow-derived stem cells (BMSCs) and joint tissue-derived stem cells following encapsulation in agarose hydrogels. Culture-expanded BMSCs, fat pad-derived stem cells (FPSCs), and synovial membrane-derived stem cells (SDSCs) were encapsulated in agarose and maintained in a chondrogenic medium supplemented with transforming growth factor-β3. After 21 days of culture, constructs were either implanted subcutaneously into the back of nude mice for an additional 28 days or maintained for a similar period in vitro in either chondrogenic or hypertrophic media formulations. After 49 days of in vitro culture in chondrogenic media, SDSC constructs accumulated the highest levels of sulfated glycosaminoglycan (sGAG) (∼2.8% w/w) and collagen (∼1.8% w/w) and were mechanically stiffer than constructs engineered using other cell types. After subcutaneous implantation in nude mice, sGAG content significantly decreased for all stem cell-seeded constructs, while no significant change was observed in the control constructs engineered using primary CCs, indicating that the in vitro chondrocyte-like phenotype generated in all stem cell-seeded agarose constructs was transient. FPSCs and SDSCs appeared to undergo fibrous dedifferentiation or resorption, as evident from increased collagen type I staining and a dramatic loss in sGAG content. BMSCs followed a more endochondral pathway with increased type X collagen expression and mineralization of the engineered tissue. In conclusion, while joint tissue-derived stem cells possess a strong intrinsic chondrogenic capacity, further studies are needed to identify the factors that will lead to the generation

The cell death factor, cell wall elicitor of rice blast fungus (Magnaporthe grisea) causes metabolic alterations including GABA shunt in rice cultured cells

OpenAIRE

Takahashi, Hideyuki; Matsumura, Hideo; Kawai-Yamada, Maki; Uchimiya, Hirofumi

2008-01-01

An elicitor derived from the cell wall of rice blast fungus (Magnaporthe grisea) causes cell death in suspension cultured cells of rice (Oryza sativa L.). To elucidate the role of M. grisea elicitor on metabolic pathway of rice cells, we performed metabolite profiling using capillary electrophoresis-mass spectrometry (CE/MS). Treatment with M. grisea elicitor increased the amounts of antioxidants and free amino acids and decreased the amount of metabolites in the tricarboxylic acid (TCA) cycl...

Tumor cell anaplasia and multinucleation are predictors of disease recurrence in oropharyngeal squamous cell carcinoma, including among just the human papillomavirus-related cancers.

Science.gov (United States)

Lewis, James S; Scantlebury, Juliette B; Luo, Jingqin; Thorstad, Wade L

2012-07-01

Oropharyngeal squamous cell carcinoma (SCC) is frequently related to high risk human papillomavirus. This tumor expresses p16, frequently has a nonkeratinizing morphology, and has improved outcomes. Despite having a good prognosis, tumors can have focal or diffuse nuclear anaplasia or multinucleation, the significance of which is unknown. From a database of 270 oropharyngeal SCCs with known histologic typing (using our established system) and p16 immunohistochemistry, all surgically resected cases (149) were reviewed. Anaplasia was defined as any × 40 field with ≥ 3 tumor nuclei with diameters ≥ 5 lymphocyte nuclei (~25 μm), and multinucleation was defined as any × 40 field with ≥ 3 tumor cells with multiple nuclei. p16 was positive in 128 cases (85.9%), 64 cases (43.0%) showed anaplasia, and 71 (47.7%) showed multinucleation. Anaplasia and multinucleation were highly related (Panaplasia or multinucleation had worse overall, disease-specific, and disease-free survival (Panaplasia and multinucleation both predicted worse disease-specific survival (hazard ratio 9.9, P=0.04; and hazard ratio 11.9, P=0.02, respectively) independent of the other variables. In summary, among surgically resectable oropharyngeal SCC (including among just the p16-positive cohort), tumor cell anaplasia and multinucleation independently correlated with disease recurrence and poorer survival.

New chondrosarcoma cell lines and mouse models to study the link between chondrogenesis and chemoresistance.

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Monderer, David; Luseau, Alexandrine; Bellec, Amélie; David, Emmanuelle; Ponsolle, Stéphanie; Saiagh, Soraya; Bercegeay, Sylvain; Piloquet, Philippe; Denis, Marc G; Lodé, Laurence; Rédini, Françoise; Biger, Marine; Heymann, Dominique; Heymann, Marie-Françoise; Le Bot, Ronan; Gouin, François; Blanchard, Frédéric

2013-10-01

Chondrosarcomas are cartilage-forming, poorly vascularized tumors. They represent the second malignant primary bone tumor of adults after osteosarcoma, but in contrast to osteosarcoma they are resistant to chemotherapy and radiotherapy, surgical excision remaining the only therapeutic option. Few cell lines and animal models are available, and the mechanisms behind their chemoresistance remain largely unknown. Our goal was to establish new cell lines and animal cancer models from human chondrosarcoma biopsies to study their chemoresistance. Between 2007 and 2012, 10 chondrosarcoma biopsies were collected and used for cell culture and transplantation into nude mice. Only one transplanted biopsy and one injected cell line has engrafted successfully leading to conventional central high-grade chondrosarcoma similar to the original biopsies. In culture, two new stable cell lines were obtained, one from a dedifferentiated and one from a grade III conventional central chondrosarcoma biopsy. Their genetic characterization revealed triploid karyotypes, mutations in IDH1, IDH2, and TP53, deletion in CDKN2A and/or MDM2 amplification. These cell lines expressed mesenchymal membrane markers (CD44, 73, 90, 105) and were able to produce a hyaline cartilaginous matrix when cultured in chondrogenic three-dimensional (3D) pellets. Using a high-throughput quantitative RT-PCR approach, we observed that cell lines cultured in monolayer had lost expression of several genes implicated in cartilage development (COL2A1, COMP, ACAN) but restored their expression in 3D cultures. Chondrosarcoma cells in monolayer were sensitive to several conventional chemotherapeutic agents but became resistant to low doses of mafosfamide or doxorubicin when cultured in 3D pellets, in parallel with an altered nucleic accumulation of the drug. Our results indicate that the cartilaginous matrix produced by chondrosarcoma cells may impair diffusion of several drugs and thus contribute to chemoresistance

Wound repair during arm regeneration in the red starfish Echinaster sepositus

KAUST Repository

Ben Khadra, Yousra

2015-06-24

Starfish can regenerate entire arms following their loss by both autotomic and traumatic amputation. Although the overall regenerative process has been studied several times in different asteroid species, there is still a considerable gap of knowledge as far as the detailed aspects of the repair phase at tissue and cellular level are concerned, particularly in post-traumatic regeneration. The present work is focused on the arm regeneration model in the Mediterranean red starfish Echinaster sepositus; in order to describe the early cellular mechanisms of arm regeneration following traumatic amputation, different microscopy techniques were employed. In E. sepositus, the repair phase was characterized by prompt wound healing by a syncytial network of phagocytes and re-epithelialisation followed by a localized subepidermal oedematous area formation. Scattered and apparently undifferentiated cells, intermixed with numerous phagocytes, were frequently found in the wound area during these first stages of regeneration and extensive dedifferentiation phenomena were seen at the level of the stump, particularly in the muscle bundles. A true localized blastema did not form. Our results confirm that regeneration in asteroids mainly relies on morphallactic processes, consisting in extensive rearrangement of the existing tissues which contribute to the new tissues through cell dedifferentiation, re-differentiation and/or migration. This article is protected by copyright. All rights reserved.

Merkel Cell Carcinomas Arising in Autoimmune Disease Affected Patients Treated with Biologic Drugs, Including Anti-TNF.

Science.gov (United States)

Rotondo, John Charles; Bononi, Ilaria; Puozzo, Andrea; Govoni, Marcello; Foschi, Valentina; Lanza, Giovanni; Gafà, Roberta; Gaboriaud, Pauline; Touzé, Françoise Antoine; Selvatici, Rita; Martini, Fernanda; Tognon, Mauro

2017-07-15

Purpose: The purpose of this investigation was to characterize Merkel cell carcinomas (MCC) arisen in patients affected by autoimmune diseases and treated with biologic drugs. Experimental Design: Serum samples from patients with MCC were analyzed for the presence and titer of antibodies against antigens of the oncogenic Merkel cell polyomavirus (MCPyV). IgG antibodies against the viral oncoproteins large T (LT) and small T (ST) antigens and the viral capsid protein-1 were analyzed by indirect ELISA. Viral antigens were recombinant LT/ST and virus-like particles (VLP), respectively. MCPyV DNA sequences were studied using PCR methods in MCC tissues and in peripheral blood mononuclear cells (PBMC). Immunohistochemical (IHC) analyses were carried out in MCC tissues to reveal MCPyV LT oncoprotein. Results: MCPyV DNA sequences identified in MCC tissues showed 100% homology with the European MKL-1 strain. PBMCs from patients tested MCPyV-negative. Viral DNA loads in the three MCC tissues were in the 0.1 to 30 copy/cell range. IgG antibodies against LT/ST were detected in patients 1 and 3, whereas patient 2 did not react to the MCPyV LT/ST antigen. Sera from the three patients with MCC contained IgG antibodies against MCPyV VP1. MCC tissues tested MCPyV LT-antigen-positive in IHC assays, with strong LT expression with diffuse nuclear localization. Normal tissues tested MCPyV LT-negative when employed as control. Conclusions: We investigated three new MCCs in patients affected by rheumatologic diseases treated with biologic drugs, including TNF. A possible cause-effect relationship between pharmacologic immunosuppressive treatment and MCC onset is suggested. Indeed, MCC is associated with MCPyV LT oncoprotein activity. Clin Cancer Res; 23(14); 3929-34. ©2017 AACR . ©2017 American Association for Cancer Research.

DSP30 and interleukin-2 as a mitotic stimulant in B-cell disorders including those with a low disease burden.

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Dun, Karen A; Riley, Louise A; Diano, Giuseppe; Adams, Leanne B; Chiu, Eleanor; Sharma, Archna

2018-05-01

Chromosome abnormalities detected during cytogenetic investigations for B-cell malignancy offer prognostic information that can have wide ranging clinical impacts on patients. These impacts may include monitoring frequency, treatment type, and disease staging level. The use of the synthetic oligonucleotide DSP30 combined with interleukin 2 (IL2) has been described as an effective mitotic stimulant in B-cell disorders, not only in chronic lymphocytic leukemia (CLL) but also in a range of other B-cell malignancies. Here, we describe the comparison of two B-cell mitogens, lipopolysaccharide (LPS), and DSP30 combined with IL2 as mitogens in a range of common B-cell disorders excluding CLL. The results showed that DSP30/IL2 was an effective mitogen in mature B-cell disorders, revealing abnormal cytogenetic results in a range of B-cell malignancies. The abnormality rate increased when compared to the use of LPS to 64% (DSP30/IL2) from 14% (LPS). In a number of cases the disease burden was proportionally very low, less than 10% of white cells. In 37% of these cases, the DSP30 culture revealed abnormal results. Importantly, we also obtained abnormal conventional cytogenetics results in 3 bone marrow cases in which immunophenotyping showed an absence of an abnormal B-cell clone. In these cases, the cytogenetics results correlated with the provisional diagnosis and altered their staging level. The use of DSP30 and IL2 is recommended for use in many B-cell malignancies as an effective mitogen and their use has been shown to enable successful culture of the malignant clone, even at very low levels of disease. © 2018 Wiley Periodicals, Inc.

Reversible differentiation of myofibroblasts by MyoD

International Nuclear Information System (INIS)

Hecker, Louise; Jagirdar, Rajesh; Jin, Toni; Thannickal, Victor J.

2011-01-01

Myofibroblasts participate in tissue repair processes in diverse mammalian organ systems. The deactivation of myofibroblasts is critical for termination of the reparative response and restoration of tissue structure and function. The current paradigm on normal tissue repair is the apoptotic clearance of terminally differentiated myofibroblasts; while, the accumulation of activated myofibroblasts is associated with progressive human fibrotic disorders. The capacity of myofibroblasts to undergo de-differentiation as a potential mechanism for myofibroblast deactivation has not been examined. In this report, we have uncovered a role for MyoD in the induction of myofibroblast differentiation by transforming growth factor-β1 (TGF-β1). Myofibroblasts demonstrate the capacity for de-differentiation and proliferation by modulation of endogenous levels of MyoD. We propose a model of reciprocal signaling between TGF-β1/ALK5/MyoD and mitogen(s)/ERK-MAPK/CDKs that regulate myofibroblast differentiation and de-differentiation, respectively. Our studies provide the first evidence for MyoD in controlling myofibroblast activation and deactivation. Restricted capacity for de-differentiation of myofibroblasts may underlie the progressive nature of recalcitrant human fibrotic disorders.

Use of fibroblast growth factor 2 for expansion of chondrocytes and tissue engineering

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Vunjak-Novakovic, Gordana (Inventor); Martin, Ivan (Inventor); Freed, Lisa E. (Inventor); Langer, Robert (Inventor)

2003-01-01

The present invention provides an improved method for expanding cells for use in tissue engineering. In particular the method provides specific biochemical factors to supplement cell culture medium during the expansion process in order to reproduce events occurring during embryonic development with the goal of regenerating tissue equivalents that resemble natural tissues both structurally and functionally. These specific biochemical factors improve proliferation of the cells and are capable of de-differentiation mature cells isolated from tissue so that the differentiation potential of the cells is preserved. The bioactive molecules also maintain the responsiveness of the cells to other bioactive molecules. Specifically, the invention provides methods for expanding chondrocytes in the presence of fibroblast growth factor 2 for use in regeneration of cartilage tissue.

Regulation of proximal tubular cell differentiation and proliferation in primary culture by matrix stiffness and ECM components.

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Chen, Wan-Chun; Lin, Hsi-Hui; Tang, Ming-Jer

2014-09-15

To explore whether matrix stiffness affects cell differentiation, proliferation, and transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition (EMT) in primary cultures of mouse proximal tubular epithelial cells (mPTECs), we used a soft matrix made from monomeric collagen type I-coated polyacrylamide gel or matrigel (MG). Both kinds of soft matrix benefited primary mPTECs to retain tubular-like morphology with differentiation and growth arrest and to evade TGF-β1-induced EMT. However, the potent effect of MG on mPTEC differentiation was suppressed by glutaraldehyde-induced cross-linking and subsequently stiffening MG or by an increasing ratio of collagen in the soft mixed gel. Culture media supplemented with MG also helped mPTECs to retain tubular-like morphology and a differentiated phenotype on stiff culture dishes as soft MG did. We further found that the protein level and activity of ERK were scaled with the matrix stiffness. U-0126, a MEK inhibitor, abolished the stiff matrix-induced dedifferentiation and proliferation. These data suggest that the ERK signaling pathway plays a vital role in matrix stiffness-regulated cell growth and differentiation. Taken together, both compliant property and specific MG signals from the matrix are required for the regulation of epithelial differentiation and proliferation. This study provides a basic understanding of how physical and chemical cues derived from the extracellular matrix regulate the physiological function of proximal tubules and the pathological development of renal fibrosis. Copyright © 2014 the American Physiological Society.

Immortalized human hepatocytes as a tool for the study of hepatocytic (de-)differentiation

NARCIS (Netherlands)

Schippers, IJ; Moshage, H; Roelofsen, H; Muller, M; Heymans, HSA; Ruiters, M; Kuipers, F

Primary human hepatocytes were immortalized by stable transfection with a recombinant plasmid containing the early region of simian virus (SV) 40. The cells were cultured in serum-free, hormonally defined medium during the immortalization procedure. Foci of dividing cells were seen after 3 months.

Analysis of myelomonocytic leukemic differentiation by a cell surface marker panel including a fucose-binding lectin from Lotus tetragonolobus.

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Elias, L; Van Epps, D E

1984-06-01

The fucose-binding lectin from Lotus tetragonolobus ( FBL -L) has been previously shown to bind specifically to normal cells of the myeloid and monocytic lineages. The purpose of this study was to explore the utility of fluoresceinated FBL -L as a leukemia differentiation marker in conjunction with a panel of other frequently used surface markers (Fc receptor, HLA-DR, OKM1, and antimonocyte antibody). FBL -L reacted with leukemic cells in 8/9 cases of clinically recognized acute myeloid leukemia, including myeloid blast crisis of chronic granulocytic leukemia, 3/3 cases of chronic phase chronic myelogenous leukemia, and in 2/7 cases of clinically undifferentiated acute leukemia. Correlations were noted between reactivity with FBL -L, and DR and Fc receptor expression. Among continuous cell lines, FBL -L bound with high intensity to a majority of HL-60 and U937 cells. The less well differentiated myeloblast cell lines, KG-1, KG1a , and HL-60 blast II, exhibited less FBL -L binding than HL-60 and U937. A moderate proportion of K562 cells exhibited low level binding of FBL -L. Several lymphoblastic cell lines exhibited a pattern of low intensity binding that was distinguishable from the high intensity binding pattern of the myeloblastic lines. FBL -L reactivity of U937 was enhanced by induction of differentiation with leukocyte conditioned medium, but not dimethylsulfoxide. Such treatments induced contrasting patterns of change of HL-60 and U937 when labeled with OKM1, alpha-Mono, and HLA-DR. These studies demonstrate the application of FBL -L to analysis and quantitation of myelomonocytic leukemic differentiation.

A review of cell-scale multiphase flow modeling, including water management, in polymer electrolyte fuel cells

International Nuclear Information System (INIS)

Andersson, M.; Beale, S.B.; Espinoza, M.; Wu, Z.; Lehnert, W.

2016-01-01

on the transport processes inside the porous GDL are extensively discussed. The selection of a computational approach, for the two-phase flow within a GDL or GC, for example, should be based on the computational resources available, concerns about time and scale (microscale, cell scale, stack scale or system scale), as well as accuracy requirements. One important feature, included in some computational approaches, is the possibility to track the front between the liquid and the gas phases. To build a PEFC model, one must make a large number of assumptions. Some assumptions have a negligible effect on the results and reliability of the model. However, other assumptions may significantly affect the result. It is strongly recommended in any modeling paper to clearly state the assumptions being implemented, for others to be able to judge the work. It is important to note that a large fraction of the expressions that presently are used to describe the transport processes inside PEFC GDLs were originally developed to describe significantly different systems, such as sand or rocks. Moreover, the flow pattern maps and pressure drop correlations of two phase flow in micro channels may not be applicable for GCs due to one side wall being porous, with the resulting interaction between the GDL and GC.

Changes in the extracellular matrix and glycosaminoglycan synthesis during the initiation of regeneration in adult newt forelimbs

International Nuclear Information System (INIS)

Mescher, A.L.; Munaim, S.I.

1986-01-01

The extracellular matrix (ECM) of the distal tissues in a newt limb stump is completely reorganized in the 2-3-week period following amputation. In view of numerous in vitro studies showing that extracellular material influences cellular migration and proliferation, it is likely that the changes in the limb's ECM are important activities in the process leading to regeneration of such limbs. Using biochemical, autoradiographic, and histochemical techniques we studied temporal and spatial differences in the synthesis of glycosaminoglycans (GAGs) during the early, nerve-dependent phase of limb regeneration. Hyaluronic acid synthesis began with the onset of tissue dedifferentiation, became maximal within 1 weeks, and continued throughout the period of active cell proliferation. Chondroitin sulfate synthesis began somewhat later, increased steadily, and reached very high levels during chondrogenesis. During the first 10 days after amputation, distributions of sulfated and nonsulfated GAGs were both uniform throughout dedifferentiating tissues, except for a heavier localization near the bone. Since nerves are necessary to promote the regenerative process, we examined the neural influence on synthesis and accumulation of extracellular GAGs. Denervation decreased GAG production in all parts of the limb stump by approximately 50%. Newt dorsal root ganglia and brain-derived fibroblast growth factor each produced twofold stimulation of GAG synthesis in cultured 7-day regenerates. The latter effect was primarily on synthesis of hyaluronic acid. The results indicate that the trophic action of nerves on amphibian limb regeneration includes a positive influence on synthesis and extracellular accumulation of GAGs

Renal Cell Carcinoma With Chromosome 6p Amplification Including the TFEB Gene: A Novel Mechanism of Tumor Pathogenesis?

Science.gov (United States)

Williamson, Sean R; Grignon, David J; Cheng, Liang; Favazza, Laura; Gondim, Dibson D; Carskadon, Shannon; Gupta, Nilesh S; Chitale, Dhananjay A; Kalyana-Sundaram, Shanker; Palanisamy, Nallasivam

2017-03-01

Amplification of chromosome 6p has been implicated in aggressive behavior in several cancers, but has not been characterized in renal cell carcinoma (RCC). We identified 9 renal tumors with amplification of chromosome 6p including the TFEB gene, 3 by fluorescence in situ hybridization, and 6 from the Cancer Genome Atlas (TCGA) databases. Patients' ages were 28 to 78 years (median, 61 y). Most tumors were high stage (7/9 pT3a, 2/9 pN1). Using immunohistochemistry, 2/4 were positive for melanocytic markers and cathepsin K. Novel TFEB fusions were reported by TCGA in 2; however, due to a small composition of fusion transcripts compared with full-length transcripts (0.5/174 and 3.3/132 FPKM), we hypothesize that these represent secondary fusions due to amplification. Five specimens (4 TCGA, 1 fluorescence in situ hybridization) had concurrent chromosome 3p copy number loss or VHL deletion. However, these did not resemble clear cell RCC, had negative carbonic anhydrase IX labeling, lacked VHL mutation, and had papillary or unclassified histology (2/4 had gain of chromosome 7 or 17). One tumor each had somatic FH mutation and SMARCB1 mutation. Chromosome 6p amplification including TFEB is a previously unrecognized cytogenetic alteration in RCC, associated with heterogenous tubulopapillary eosinophilic and clear cell histology. The combined constellation of features does not fit cleanly into an existing tumor category (unclassified), most closely resembling papillary or translocation RCC. The tendency for high tumor stage, varied tubulopapillary morphology, and a subset with melanocytic marker positivity suggests the possibility of a unique tumor type, despite some variation in appearance and genetics.

MiR-7 triggers cell cycle arrest at the G1/S transition by targeting multiple genes including Skp2 and Psme3.

Directory of Open Access Journals (Sweden)

Noelia Sanchez

Full Text Available MiR-7 acts as a tumour suppressor in many cancers and abrogates proliferation of CHO cells in culture. In this study we demonstrate that miR-7 targets key regulators of the G1 to S phase transition, including Skp2 and Psme3, to promote increased levels of p27(KIP and temporary growth arrest of CHO cells in the G1 phase. Simultaneously, the down-regulation of DNA repair-specific proteins via miR-7 including Rad54L, and pro-apoptotic regulators such as p53, combined with the up-regulation of anti-apoptotic factors like p-Akt, promoted cell survival while arrested in G1. Thus miR-7 can co-ordinate the levels of multiple genes and proteins to influence G1 to S phase transition and the apoptotic response in order to maintain cellular homeostasis. This work provides further mechanistic insight into the role of miR-7 as a regulator of cell growth in times of cellular stress.

Is there a role for diffusion-weighted MRI (DWI) in the diagnosis of central cartilage tumors?

International Nuclear Information System (INIS)

Douis, H.; Jeys, L.; Grimer, R.; Vaiyapuri, S.; Davies, A.M.

2015-01-01

To assess if diffusion-weighted MRI (DWI) can differentiate between central enchondromas and chondrosarcomas (CS) and if DWI can distinguish low-grade chondroid lesions from high-grade CS. Fifty-two patients with central cartilage tumors were included. Patients underwent conventional MRI and DWI with ADC mapping. The slice on MRI with the most aggressive imaging feature was identified. The corresponding mean and minimum ADC maps of the tumor at this position were measured. There were 24 enchondromas, five atypical cartilaginous lesions, 15 grade 1, three grade 2, two grade 3, and three dedifferentiated CS. Mean ADC values (x 10 -6 mm 2 /s) for enchondromas, atypical cartilaginous tumors, grade 1 CS, grade 2, CS, grade 3 CS and dedifferentiated CS were 1,896, 2,048, 2,152, 2,170, 2,076, and 1,261, respectively. Minimum ADC values (x 10 -6 mm 2 /s) for enchondromas, atypical cartilaginous tumors, grade 1 CS, grade 2, CS, grade 3 CS and dedifferentiated CS were 1,820, 1,752, 2,010, 1,829, 1,752, and 767, respectively. ANOVA test demonstrated a statistically significant difference in mean and minimum ADC values in all groups. Post hoc analysis revealed this was due to difference in mean and minimum ADC values in dedifferentiated CS. The mean ADC value in low-grade chondroid lesions was 2,001, while the ADC value for high-grade CS were 2,132. The minimum ADC value for low-grade chondroid lesions was 1,896, while the minimum ADC for high-grade CS was 1,837. The difference in minimum and mean ADC values was not statistically significant. DWI cannot differentiate between enchondromas and CS and DWI does not aid in the distinction of low-grade chondroid tumors from high-grade CS. (orig.)

BAG3 promotes the phenotypic transformation of primary rat vascular smooth muscle cells via TRAIL.

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Fu, Yao; Chang, Ye; Chen, Shuang; Li, Yuan; Chen, Yintao; Sun, Guozhe; Yu, Shasha; Ye, Ning; Li, Chao; Sun, Yingxian

2018-05-01

Under normal physiological condition, the mature vascular smooth muscle cells (VSMCs) show differentiated phenotype. In response to various environmental stimuluses, VSMCs convert from the differentiated phenotype to dedifferentiated phenotype characterized by the increased ability of proliferation/migration and the reduction of contractile ability. The phenotypic transformation of VSMCs played an important role in atherosclerosis. Both Bcl-2-associated athanogene 3 (BAG3) and tumor necrosis factor-related apopt-osis inducing ligand (TRAIL) involved in apoptosis. The relationship between BAG3 and TRAIL and their effects the proliferation and migration in VSMCs are rarely reported. This study investigated the effects of BAG3 on the phenotypic modulation and the potential underlying mechanisms in primary rat VSMCs. Primary rat VSMCs were extracted and cultured in vitro. Cell proliferation was detected by cell counting, real-time cell analyzer (RTCA) and EdU incorporation. Cell migration was detected by wound healing, Transwell and RTCA. BAG3 and TRAIL were detected using real-time PCR and western blotting and the secreted proteins in the cultured media by dot blot. The expression of BAG3 increased with continued passages in cultured primary VSMCs. BAG3 promoted the proliferation and migration of primary rat VSMC in a time-dependent manner. BAG3 significantly increased the expression of TRAIL while had no effects on its receptors. TRAIL knockdown or blocking by neutralizing antibody inhibited the proliferation of VSMCs induced by BAG3. TRAIL knockdown exerted no obvious influence on the migration of VSMCs. Based on this study, we report for the first time that BAG3 was expressed in cultured primary rat VSMCs and the expression of BAG3 increased with continued passages. Furthermore, BAG3 promoted the proliferation of VSMCs via increasing the expression of TRAIL. In addition, we also demonstrated that BAG3 promoted the migration of VSMCs independent of TRAIL

In vitro rhizogenesis: histoanatomy of Cedrela odorata (Meliaceae microcuttings

Directory of Open Access Journals (Sweden)

Liliana Millán-Orozco

2011-03-01

Full Text Available Cedrela odorata (Meliaceae is considered as one of the most valuable forest tree in the tropics. Clonal propagation of this species provide an alternative method to propagate superior genotypes, being the production of good quality adventitious roots one of the most important steps in micropropagation techniques. The sequence of anatomical changes that takes place during the formation of adventitious roots in shoots of Cedrela odorata cultured in vitro is described in this study. Eigth-week-old shoots, from multiplication cultures, were rooted in Murashige and Skoog´s medium (1962 with half- strength macronutrients and with 0 or 1mg/l indole-3-butyric acid (IBA. Between 12 and 24h after the start of rooting, some cambium, phloem and interfascicular parenchyma cells became dense cytoplasm, nuclei with prominent nucleoli and the first cell divisions were observed, especially in shoots treated with auxin (dedifferentiation phase. After 3-4 days, the number of dedifferentiated cells and mitotic divisions increased considerably, and the formation of groups of some 30-40 meristematic cells (meristemoids was observed (induction phase. The first primordial roots developed from the 4th-5th day. The vascular tissues of these primordia connected to those of the explant, and roots began to emerge from the base by day 6. Development of the primordial roots was similar in the control shoots and shoots treated with 1mg/l IBA, although there were more roots per explant in the latter. Rev. Biol. Trop. 59 (1: 447-453. Epub 2011 March 01.

RNA interference targeting CD147 inhibits the proliferation, invasiveness, and metastatic activity of thyroid carcinoma cells by down-regulating glycolysis

Science.gov (United States)

Huang, Peng; Chang, Shi; Jiang, Xiaolin; Su, Juan; Dong, Chao; Liu, Xu; Yuan, Zhengtai; Zhang, Zhipeng; Liao, Huijun

2015-01-01

A high rate of glycolytic flux, even in the presence of oxygen, is a key metabolic hallmark of cancer cells. Lactate, the end product of glycolysis, decreases the extracellular pH and contributes to the proliferation, invasiveness and metastasis of tumor cells. CD147 play a crucial role in tumorigenicity, invasion and metastasis; and CD147 also interacts strongly and specifically with monocarboxylate transporter1 (MCT1) that mediates the transport of lactate. The objective of this study was to determine whether CD147 is involved, via its association with MCT1 to transport lactate, in glycolysis, contributing to the progression of thyroid carcinoma. The expression levels of CD147 in surgical specimens of normal thyroid, nodular goiter (NG), well-differentiated thyroid carcinoma (WDTC), and undifferentiated thyroid carcinoma (UDTC) were determined using immunohistochemical techniques. The effects of CD147 silencing on cell proliferation, invasiveness, metastasis, co-localization with MCT1, glycolysis rate and extracellular pH of thyroid cancer cells (WRO and FRO cell lines) were measured after CD147 was knocked-down using siRNA targeting CD147. Immunohistochemical analysis of thyroid carcinoma (TC) tissues revealed significant increases in signal for CD147 compared with normal tissue or NG, while UDTC expressed remarkably higher levels of CD147 compared with WDTC. Furthermore, silencing of CD147 in TC cells clearly abrogated the expression of MCT1 and its co-localization with CD147 and dramatically decreased both the glycolysis rate and extracellular pH. Thus, cell proliferation, invasiveness, and metastasis were all significantly decreased by siRNA. These results demonstrate in vitro that the expression of CD147 correlates with the degree of dedifferentiation of thyroid cancer, and show that CD147 interacts with MCT1 to regulate tumor cell glycolysis, resulting in the progression of thyroid carcinoma. PMID:25755717

Activated Hepatic Stellate Cells Induce Tumor Progression of Neoplastic Hepatocytes in a TGF-β Dependent Fashion

Science.gov (United States)

MIKULA, M.; PROELL, V.; FISCHER, A.N.M.; MIKULITS, W.

2010-01-01

The development of hepatocellular carcinomas from malignant hepatocytes is frequently associated with intra- and peritumoral accumulation of connective tissue arising from activated hepatic stellate cells. For both tumorigenesis and hepatic fibrogenesis, transforming growth factor (TGF)-β signaling executes key roles and therefore is considered as a hallmark of these pathological events. By employing cellular transplantation we show that the interaction of neoplastic MIM-R hepatocytes with the tumor microenvironment, containing either activated hepatic stellate cells (M1-4HSCs) or myofibroblasts derived thereof (M-HTs), induces progression in malignancy. Cotransplantation of MIM-R hepatocytes with M-HTs yielded strongest MIM-R generated tumor formation accompanied by nuclear localization of Smad2/3 as well as of β-catenin. Genetic interference with TGF-β signaling by gain of antagonistic Smad7 in MIM-R hepatocytes diminished epithelial dedifferentiation and tumor progression upon interaction with M1-4HSCs or M-HTs. Further analysis showed that tumors harboring disrupted Smad signaling are devoid of nuclear β-catenin accumulation, indicating a crosstalk between TGF-β and β-catenin signaling. Together, these data demonstrate that activated HSCs and myofibroblasts directly govern hepatocarcinogenesis in a TGF-β dependent fashion by inducing autocrine TGF-β signaling and nuclear β-catenin accumulation in neoplastic hepatocytes. These results indicate that intervention with TGF-β signaling is highly promising in liver cancer therapy. PMID:16883581

Adipocytes properties and crosstalk with immune system in obesity-related inflammation.

Science.gov (United States)

Maurizi, Giulia; Della Guardia, Lucio; Maurizi, Angela; Poloni, Antonella

2018-01-01

Obesity is a condition likely associated with several dysmetabolic conditions or worsening of cardiovascular and other chronic disturbances. A key role in this mechanism seem to be played by the onset of low-grade systemic inflammation, highlighting the importance of the interplay between adipocytes and immune system cells. Adipocytes express a complex and highly adaptive biological profile being capable to selectively activate different metabolic pathways in order to respond to environmental stimuli. It has been demonstrated how adipocytes, under appropriate stimulation, can easily differentiate and de-differentiate thereby converting themselves into different phenotypes according to metabolic necessities. Although underlying mechanisms are not fully understood, growing in adipocyte size and the inability of storing triglycerides under overfeeding conditions seem to be crucial for the switching to a dysfunctional metabolic profile, which is characterized by inflammatory and apoptotic pathways activation, and by the shifting to pro-inflammatory adipokines secretion. In obesity, changes in adipokines secretion along with adipocyte deregulation and fatty acids release into circulation contribute to maintain immune cells activation as well as their infiltration into regulatory organs. Over the well-established role of macrophages, recent findings suggest the involvement of new classes of immune cells such as T regulatory lymphocytes and neutrophils in the development inflammation and multi systemic worsening. Deeply understanding the pathways of adipocyte regulation and the de-differentiation process could be extremely useful for developing novel strategies aimed at curbing obesity-related inflammation and related metabolic disorders. © 2017 Wiley Periodicals, Inc.

Antigenic and Genotypic Similarity between Primary Glioblastomas and Their Derived Neurospheres

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Valentina Caldera

2011-01-01

Full Text Available Formation of neurospheres (NS in cultures of glioblastomas (GBMs, with self-renewal, clonogenic capacities, and tumorigenicity following transplantation into immunodeficient mice, may denounce the existence of brain tumor stem cells (BTSCs in vivo. In sixteen cell lines from resected primary glioblastomas, NS showed the same genetic alterations as primary tumors and the expression of stemness antigens. Adherent cells (AC, after adding 10% of fetal bovine serum (FBS to the culture, were genetically different from NS and prevailingly expressed differentiation antigens. NS developed from a highly malignant tumor phenotype with proliferation, circumscribed necrosis, and high vessel density. Beside originating from transformed neural stem cells (NSCs, BTSCs may be contained within or correspond to dedifferentiated cells after mutation accumulation, which reacquire the expression of stemness antigens.

In a patient with biclonal Waldenstrom macroglobulinemia only one clone expands in three-dimensional culture and includes putative cancer stem cells.

Science.gov (United States)

Kirshner, Julia; Thulien, Kyle J; Kriangkum, Jitra; Motz, Sarah; Belch, Andrew R; Pilarski, Linda M

2011-02-01

A small percentage of cases of Waldenstrom macroglobulinemia (WM) present with biclonality, defined here as the rearrangement of two distinct VDJ gene segments. Here we investigated the expansion of two clones from a patient with WM expressing molecularly detectable clonotypic gene rearrangements, one V(H)3 and one V(H)4. Biclonality was determined in blood and bone marrow mononuclear cells using real-time quantitative PCR (RQ-PCR). V(H)4 expressing cells but not V(H)3 expressing cells underwent clonal expansion in 3-D culture of reconstructed WM bone marrow. After 3-D culture, secondary culture in a colony forming unit assay, and RQ-PCR, only the V(H)4 clone was shown to harbor a subpopulation with characteristics of cancer stem cells, including proliferative quiescence, self-regeneration, and the ability to generate clonotypic progeny, suggesting that the V(H)4, but not the V(H)3, clone is clinically significant. Enrichment of potential WM stem cells in 3-D cultures holds promise for monitoring their response to treatment and for testing new therapies.

Proteomic plasma membrane profiling reveals an essential role for gp96 in the cell surface expression of LDLR family members, including the LDL receptor and LRP6.

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Weekes, Michael P; Antrobus, Robin; Talbot, Suzanne; Hör, Simon; Simecek, Nikol; Smith, Duncan L; Bloor, Stuart; Randow, Felix; Lehner, Paul J

2012-03-02

The endoplasmic reticulum chaperone gp96 is required for the cell surface expression of a narrow range of proteins, including toll-like receptors (TLRs) and integrins. To identify a more comprehensive repertoire of proteins whose cell surface expression is dependent on gp96, we developed plasma membrane profiling (PMP), a technique that combines SILAC labeling with selective cell surface aminooxy-biotinylation. This approach allowed us to compare the relative abundance of plasma membrane (PM) proteins on gp96-deficient versus gp96-reconstituted murine pre-B cells. Analysis of unfractionated tryptic peptides initially identified 113 PM proteins, which extended to 706 PM proteins using peptide prefractionation. We confirmed a requirement for gp96 in the cell surface expression of certain TLRs and integrins and found a marked decrease in cell surface expression of four members of the extended LDL receptor family (LDLR, LRP6, Sorl1 and LRP8) in the absence of gp96. Other novel gp96 client proteins included CD180/Ly86, important in the B-cell response to lipopolysaccharide. We highlight common structural motifs in these client proteins that may be recognized by gp96, including the beta-propeller and leucine-rich repeat. This study therefore identifies the extended LDL receptor family as an important new family of proteins whose cell surface expression is regulated by gp96.

Current and potential immune therapies and vaccines in the management of psoriasis

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Kaffenberger, Benjamin H; Lee, Grace L; Tyler, Kelly; Chan, Derek V; Jarjour, Wael; Ariza, Maria E; Williams, Marshall V; Wong, Henry K

2014-01-01

Psoriasis is a chronic, immune skin disease associated with significant morbidity. Development of psoriasis is influenced by numerous genes, one allele is HLA-CW*0602. Other genes and single nucleotide polymorphisms affect immunologic pathways and antimicrobial peptide synthesis. Dendritic cells initiate psoriasis by activating T-cells toward a Th1 and Th17 response, with increased cytokines including TNF-α, IL-6, -12, -17, -22, and -23. IL-22 appears to promote keratinocyte dedifferentiation and increased antimicrobial peptide synthesis while TNF-α and IL-17 induce leukocyte localization within the psoriatic plaque. These recent insights identifying key cytokine pathways have led to the development of inhibitors with significant efficacy in the treatment of psoriasis. While a strategy for vaccine modulation of the immune response in psoriasis is in progress, with new technology they may provide a cost-effective long-term treatment that may induce tolerance or targeted self-inhibition for patients with autoimmune disorders, such as psoriasis. PMID:24492530

Epigenetic profiling of cutaneous T-cell lymphoma: promoter hypermethylation of multiple tumor suppressor genes including BCL7a, PTPRG, and p73.

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van Doorn, Remco; Zoutman, Willem H; Dijkman, Remco; de Menezes, Renee X; Commandeur, Suzan; Mulder, Aat A; van der Velden, Pieter A; Vermeer, Maarten H; Willemze, Rein; Yan, Pearlly S; Huang, Tim H; Tensen, Cornelis P

2005-06-10

To analyze the occurrence of promoter hypermethylation in primary cutaneous T-cell lymphoma (CTCL) on a genome-wide scale, focusing on epigenetic alterations with pathogenetic significance. DNA isolated from biopsy specimens of 28 patients with CTCL, including aggressive CTCL entities (transformed mycosis fungoides and CD30-negative large T-cell lymphoma) and an indolent entity (CD30-positive large T-cell lymphoma), were investigated. For genome-wide DNA methylation screening, differential methylation hybridization using CpG island microarrays was applied, which allows simultaneous detection of the methylation status of 8640 CpG islands. Bisulfite sequence analysis was applied for confirmation and detection of hypermethylation of eight selected tumor suppressor genes. The DNA methylation patterns of CTCLs emerging from differential methylation hybridization analysis included 35 CpG islands hypermethylated in at least four of the 28 studied CTCL samples when compared with benign T-cell samples. Hypermethylation of the putative tumor suppressor genes BCL7a (in 48% of CTCL samples), PTPRG (27%), and thrombospondin 4 (52%) was confirmed and demonstrated to be associated with transcriptional downregulation. BCL7a was hypermethylated at a higher frequency in aggressive (64%) than in indolent (14%) CTCL entities. In addition, the promoters of the selected tumor suppressor genes p73 (48%), p16 (33%), CHFR (19%), p15 (10%), and TMS1 (10%) were hypermethylated in CTCL. Malignant T cells of patients with CTCL display widespread promoter hypermethylation associated with inactivation of several tumor suppressor genes involved in DNA repair, cell cycle, and apoptosis signaling pathways. In view of this, CTCL may be amenable to treatment with demethylating agents.

Mechanisms of growth inhibition of primary prostate epithelial cells following gamma irradiation or photodynamic therapy include senescence, necrosis, and autophagy, but not apoptosis

International Nuclear Information System (INIS)

Frame, Fiona M.; Savoie, Huguette; Bryden, Francesca; Giuntini, Francesca; Mann, Vincent M.; Simms, Matthew S.; Boyle, Ross W.; Maitland, Norman J.

2015-01-01

In comparison to more differentiated cells, prostate cancer stem-like cells are radioresistant, which could explain radio-recurrent prostate cancer. Improvement of radiotherapeutic efficacy may therefore require combination therapy. We have investigated the consequences of treating primary prostate epithelial cells with gamma irradiation and photodynamic therapy (PDT), both of which act through production of reactive oxygen species (ROS). Primary prostate epithelial cells were cultured from patient samples of benign prostatic hyperplasia and prostate cancer prior to treatment with PDT or gamma irradiation. Cell viability was measured using MTT and alamar blue assay, and cell recovery by colony-forming assays. Immunofluorescence of gamma-H2AX foci was used to quantify DNA damage, and autophagy and apoptosis were assessed using Western blots. Necrosis and senescence were measured by propidium iodide staining and beta-galactosidase staining, respectively. Both PDT and gamma irradiation reduced the colony-forming ability of primary prostate epithelial cells. PDT reduced the viability of all types of cells in the cultures, including stem-like cells and more differentiated cells. PDT induced necrosis and autophagy, whereas gamma irradiation induced senescence, but neither treatment induced apoptosis. PDT and gamma irradiation therefore inhibit cell growth by different mechanisms. We suggest these treatments would be suitable for use in combination as sequential treatments against prostate cancer

Cancer risks related to low-level RF/MW exposures, including cell phones.

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Szmigielski, Stanislaw

2013-09-01

For years, radiofrequency (RF) and microwave (MW) radiations have been applied in the modern world. The rapidly increasing use of cellular phones called recent attention to the possible health risks of RF/MW exposures. In 2011, a group of international experts organized by IARC (International Agency for Research on Cancer in Lyon) concluded that RF/MW radiations should be listed as a possible carcinogen (group 2B) for humans. Three meta-analyses of case-control studies have concluded that using cell phones for more than ten years was associated with an increase in the overall risk of developing a brain tumor. The Interphone Study, the largest health-related case-control international study of use of cell phones and head and neck tumors, showed no statistically significant increases in brain cancers related to higher amounts of cell phone use, but excess risk in a small subgroup of more heavily exposed users associated with latency and laterality was reported. So far, the published studies do not show that mobile phones could for sure increase the risk of cancer. This conclusion is based on the lack of a solid biological mechanism, and the fact that brain cancer rates are not going up significantly. However, all of the studies so far have weaknesses, which make it impossible to entirely rule out a risk. Mobile phones are still a new technology and there is little evidence about effects of long-term use. For this reason, bioelectromagnetic experts advise application of a precautionary resources. It suggests that if people want to use a cell phone, they can choose to minimize their exposure by keeping calls short and preferably using hand-held sets. It also advises discouraging children from making non essential calls as well as also keeping their calls short.

Molecular network including eIF1AX, RPS7, and 14-3-3γ regulates protein translation and cell proliferation in bovine mammary epithelial cells.

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Yu, Cuiping; Luo, Chaochao; Qu, Bo; Khudhair, Nagam; Gu, Xinyu; Zang, Yanli; Wang, Chunmei; Zhang, Na; Li, Qingzhang; Gao, Xuejun

2014-12-15

14-3-3γ, an isoform of the 14-3-3 protein family, was proved to be a positive regulator of mTOR pathway. Here, we analyzed the function of 14-3-3γ in protein synthesis using bovine mammary epithelial cells (BMECs). We found that 14-3-3γ interacted with eIF1AX and RPS7 by 14-3-3γ coimmunoprecipitation (CoIP) and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight (MALDI-TOF/TOF) peptide mass fingerprinting analysis. These interactions of 14-3-3γ with eIF1AX and RPS7 were further confirmed by colocalization and fluorescence resonance energy transfer (FRET) analysis. We also found that methionine could promote protein synthesis and trigger the protein expression levels of 14-3-3γ, eIF1AX and RPS7. Analysis of overexpression and inhibition of 14-3-3γ confirmed that it positively affected the protein expression levels of eIF1AX, RPS7, Stat5 and mTOR pathway to promote protein synthesis and cell proliferation in BMECs. We further showed that overexpression of eIF1AX and RPS7 also triggered protein translation and cell proliferation. From these results, we conclude that molecular network including eIF1AX, RPS7, and 14-3-3γ regulates protein translation and cell proliferation in BMECs. Copyright © 2014 Elsevier Inc. All rights reserved.

The Role of IQGAP1 in Breast Carcinoma

Science.gov (United States)

2010-01-10

prostate cancer [32]. Increased MAPK kinase (MEK) phosphorylation has been identified in colon cancer [33] and in 74% of myeloblasts in acute myelogenous... leukemia [34]. IQGAP1 is a MAPK scaffold, which binds directly to and modu- lates the functions of B-Raf [35], MEK [36] and ERK [37]. IQGAP1 is required...cadherin in the insol- uble fraction, but both are insoluble in undifferentiated tumors [85]. Consequently, it is thought that as tumor cells de-differenti

Low Frequencies of Autoimmunity-Associated PTPN22 Polymorphisms in MODY Patients, Including Those Transiently Expressing Islet Cell Autoantibodies.

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Heneberg, Petr; Malá, Milena; Yorifuji, Tohru; Gat-Yablonski, Galia; Lebenthal, Yael; Tajima, Toshihiro; Nogaroto, Viviane; Rypáčková, Blanka; Kocková, Lucie; Urbanová, Jana; Anděl, Michal

2015-01-01

The protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene encodes lymphoid tyrosine phosphatase (LYP), which is expressed primarily in lymphoid tissues. The functional but geographically highly variable PTPN22 single-nucleotide polymorphisms (SNPs), particularly c.1858C>T, contribute to the onset and progression of autoimmunity-associated diseases and facilitate the expression of disease-associated autoantibodies. In Central Europe, 17-25% of patients with monogenic diabetes (maturity-onset diabetes of the young, MODY) transiently express islet cell autoantibodies. We addressed the links between the functional and geographically variable PTPN22 SNPs with MODY manifestation and the expression of islet cell autoantibodies in 276 MODY patients who originated from four regions (the Czech Republic, Israel, Japan and Brazil). The frequency of PTPN22 polymorphisms in the MODY patients was similar to those in geographically matched healthy populations, with the exception of c.788G>A, the minor allele frequency of which was significantly elevated in the Czech hepatocyte nuclear factor 1-α (HNF1A) MODY patients [odds ratio (OR) 4.8, 95% confidence interval (CI) 2.2-10.7] and the Brazilian MODY patients (OR 8.4, 95% CI 1.8-39.1). A barely significant increase in the c.788G>A minor allele was also detected in the islet cell autoantibody-positive Czech MODY patients. However, c.788A behaves as a loss-of-function mutant in T cells, and thus protects against autoimmunity. MODY patients (including islet cell autoantibody-positive cases) do not display any increase in autoimmunity-associated PTPN22 alleles. The absence of autoimmunity-associated PTPN22 alleles was also demonstrated in latent autoimmune diabetes in adults, which suggests that the slow kinetics of the onset of autoantibodies is subject to a regulation that is different from that experienced in type 1 diabetes and other autoimmune disorders. © 2015 S. Karger AG, Basel.

Molecular Pathogenesis and Diagnostic, Prognostic and Predictive Molecular Markers in Sarcoma.

Science.gov (United States)

Mariño-Enríquez, Adrián; Bovée, Judith V M G

2016-09-01

Sarcomas are infrequent mesenchymal neoplasms characterized by notable morphological and molecular heterogeneity. Molecular studies in sarcoma provide refinements to morphologic classification, and contribute diagnostic information (frequently), prognostic stratification (rarely) and predict therapeutic response (occasionally). Herein, we summarize the major molecular mechanisms underlying sarcoma pathogenesis and present clinically useful diagnostic, prognostic and predictive molecular markers for sarcoma. Five major molecular alterations are discussed, illustrated with representative sarcoma types, including 1. the presence of chimeric transcription factors, in vascular tumors; 2. abnormal kinase signaling, in gastrointestinal stromal tumor; 3. epigenetic deregulation, in chondrosarcoma, chondroblastoma, and other tumors; 4. deregulated cell survival and proliferation, due to focal copy number alterations, in dedifferentiated liposarcoma; 5. extreme genomic instability, in conventional osteosarcoma as a representative example of sarcomas with highly complex karyotype. Copyright © 2016 Elsevier Inc. All rights reserved.

Mesenchymal stem cell-derived extracellular matrix enhances chondrogenic phenotype of and cartilage formation by encapsulated chondrocytes in vitro and in vivo.

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Yang, Yuanheng; Lin, Hang; Shen, He; Wang, Bing; Lei, Guanghua; Tuan, Rocky S

2018-03-15

Mesenchymal stem cell derived extracellular matrix (MSC-ECM) is a natural biomaterial with robust bioactivity and good biocompatibility, and has been studied as a scaffold for tissue engineering. In this investigation, we tested the applicability of using decellularized human bone marrow derived MSC-ECM (hBMSC-ECM) as a culture substrate for chondrocyte expansion in vitro, as well as a scaffold for chondrocyte-based cartilage repair. hBMSC-ECM deposited by hBMSCs cultured on tissue culture plastic (TCP) was harvested, and then subjected to a decellularization process to remove hBMSCs. Compared with chondrocytes grown on TCP, chondrocytes seeded onto hBMSC-ECM exhibited significantly increased proliferation rate, and maintained better chondrocytic phenotype than TCP group. After being expanded to the same cell number and placed in high-density micromass cultures, chondrocytes from the ECM group showed better chondrogenic differentiation profile than those from the TCP group. To test cartilage formation ability, composites of hBMSC-ECM impregnated with chondrocytes were subjected to brief trypsin treatment to allow cell-mediated contraction, and folded to form 3-dimensional chondrocyte-impregnated hBMSC-ECM (Cell/ECM constructs). Upon culture in vitro in chondrogenic medium for 21 days, robust cartilage formation was observed in the Cell/ECM constructs. Similarly prepared Cell/ECM constructs were tested in vivo by subcutaneous implantation into SCID mice. Prominent cartilage formation was observed in the implanted Cell/ECM constructs 14 days post-implantation, with higher sGAG deposition compared to controls consisting of chondrocyte cell sheets. Taken together, these findings demonstrate that hBMSC-ECM is a superior culture substrate for chondrocyte expansion and a bioactive matrix potentially applicable for cartilage regeneration in vivo. Current cell-based treatments for focal cartilage defects face challenges, including chondrocyte dedifferentiation, need for

Induction of erythroid differentiation in human erythroleukemia cells by depletion of malic enzyme 2.

Directory of Open Access Journals (Sweden)

Jian-Guo Ren

2010-09-01

Full Text Available Malic enzyme 2 (ME2 is a mitochondrial enzyme that catalyzes the conversion of malate to pyruvate and CO2 and uses NAD as a cofactor. Higher expression of this enzyme correlates with the degree of cell de-differentiation. We found that ME2 is expressed in K562 erythroleukemia cells, in which a number of agents have been found to induce differentiation either along the erythroid or the myeloid lineage. We found that knockdown of ME2 led to diminished proliferation of tumor cells and increased apoptosis in vitro. These findings were accompanied by differentiation of K562 cells along the erythroid lineage, as confirmed by staining for glycophorin A and hemoglobin production. ME2 knockdown also totally abolished growth of K562 cells in nude mice. Increased ROS levels, likely reflecting increased mitochondrial production, and a decreased NADPH/NADP+ ratio were noted but use of a free radical scavenger to decrease inhibition of ROS levels did not reverse the differentiation or apoptotic phenotype, suggesting that ROS production is not causally involved in the resultant phenotype. As might be expected, depletion of ME2 induced an increase in the NAD+/NADH ratio and ATP levels fell significantly. Inhibition of the malate-aspartate shuttle was insufficient to induce K562 differentiation. We also examined several intracellular signaling pathways and expression of transcription factors and intermediate filament proteins whose expression is known to be modulated during erythroid differentiation in K562 cells. We found that silencing of ME2 leads to phospho-ERK1/2 inhibition, phospho-AKT activation, increased GATA-1 expression and diminished vimentin expression. Metabolomic analysis, conducted to gain insight into intermediary metabolic pathways that ME2 knockdown might affect, showed that ME2 depletion resulted in high orotate levels, suggesting potential impairment of pyrimidine metabolism. Collectively our data point to ME2 as a potentially novel

3D hepatic cultures simultaneously maintain primary hepatocyte and liver sinusoidal endothelial cell phenotypes.

Directory of Open Access Journals (Sweden)

Yeonhee Kim

Full Text Available Developing in vitro engineered hepatic tissues that exhibit stable phenotype is a major challenge in the field of hepatic tissue engineering. However, the rapid dedifferentiation of hepatic parenchymal (hepatocytes and non-parenchymal (liver sinusoidal endothelial, LSEC cell types when removed from their natural environment in vivo remains a major obstacle. The primary goal of this study was to demonstrate that hepatic cells cultured in layered architectures could preserve or potentially enhance liver-specific behavior of both cell types. Primary rat hepatocytes and rat LSECs (rLSECs were cultured in a layered three-dimensional (3D configuration. The cell layers were separated by a chitosan-hyaluronic acid polyelectrolyte multilayer (PEM, which served to mimic the Space of Disse. Hepatocytes and rLSECs exhibited several key phenotypic characteristics over a twelve day culture period. Immunostaining for the sinusoidal endothelial 1 antibody (SE-1 demonstrated that rLSECs cultured in the 3D hepatic model maintained this unique feature over twelve days. In contrast, rLSECs cultured in monolayers lost their phenotype within three days. The unique stratified structure of the 3D culture resulted in enhanced heterotypic cell-cell interactions, which led to improvements in hepatocyte functions. Albumin production increased three to six fold in the rLSEC-PEM-Hepatocyte cultures. Only rLSEC-PEM-Hepatocyte cultures exhibited increasing CYP1A1/2 and CYP3A activity. Well-defined bile canaliculi were observed only in the rLSEC-PEM-Hepatocyte cultures. Together, these data suggest that rLSEC-PEM-Hepatocyte cultures are highly suitable models to monitor the transformation of toxins in the liver and their transport out of this organ. In summary, these results indicate that the layered rLSEC-PEM-hepatocyte model, which recapitulates key features of hepatic sinusoids, is a potentially powerful medium for obtaining comprehensive knowledge on liver metabolism

The yeast two hybrid system in a screen for proteins interacting with axolotl (Ambystoma mexicanum) Msx1 during early limb regeneration.

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Abuqarn, Mehtap; Allmeling, Christina; Amshoff, Inga; Menger, Bjoern; Nasser, Inas; Vogt, Peter M; Reimers, Kerstin

2011-07-01

Urodele amphibians are exceptional in their ability to regenerate complex body structures such as limbs. Limb regeneration depends on a process called dedifferentiation. Under an inductive wound epidermis terminally differentiated cells transform to pluripotent progenitor cells that coordinately proliferate and eventually redifferentiate to form the new appendage. Recent studies have developed molecular models integrating a set of genes that might have important functions in the control of regenerative cellular plasticity. Among them is Msx1, which induced dedifferentiation in mammalian myotubes in vitro. Herein, we screened for interaction partners of axolotl Msx1 using a yeast two hybrid system. A two hybrid cDNA library of 5-day-old wound epidermis and underlying tissue containing more than 2×10⁶ cDNAs was constructed and used in the screen. 34 resulting cDNA clones were isolated and sequenced. We then compared sequences of the isolated clones to annotated EST contigs of the Salamander EST database (BLASTn) to identify presumptive orthologs. We subsequently searched all no-hit clone sequences against non redundant NCBI sequence databases using BLASTx. It is the first time, that the yeast two hybrid system was adapted to the axolotl animal model and successfully used in a screen for proteins interacting with Msx1 in the context of amphibian limb regeneration. 2011 Elsevier B.V. All rights reserved.

Epigenetics targeted protein-vorinostat nanomedicine inducing apoptosis in heterogeneous population of primary acute myeloid leukemia cells including refractory and relapsed cases.

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Chandran, Parwathy; Kavalakatt, Anu; Malarvizhi, Giridharan Loghanathan; Vasanthakumari, Divya Rani Vikraman Nair; Retnakumari, Archana Payickattu; Sidharthan, Neeraj; Pavithran, Keechilat; Nair, Shantikumar; Koyakutty, Manzoor

2014-05-01

Aberrant epigenetics play a key role in the onset and progression of acute myeloid leukemia (AML). Herein we report in silico modelling based development of a novel, protein-vorinostat nanomedicine exhibiting selective and superior anti-leukemic activity against heterogeneous population of AML patient samples (n=9), including refractory and relapsed cases, and three representative cell lines expressing CD34(+)/CD38(-) stem cell phenotype (KG-1a), promyelocytic phenotype (HL-60) and FLT3-ITD mutation (MV4-11). Nano-vorinostat having ~100nm size exhibited enhanced cellular uptake rendering significantly lower IC50 in AML cell lines and patient samples, and induced enhanced HDAC inhibition, oxidative injury, cell cycle arrest and apoptosis compared to free vorinostat. Most importantly, nanomedicine showed exceptional single-agent activity against the clonogenic proliferative capability of bone marrow derived leukemic progenitors, while remaining non-toxic to healthy bone marrow cells. Collectively, this epigenetics targeted nanomedicine appears to be a promising therapeutic strategy against various French-American-British (FAB) classes of AML. Through the use of a protein-vorinostat agent, exceptional single-agent activity was demonstrated against the clonogenic proliferative capability of bone marrow derived leukemic progenitors, while remaining non-toxic to healthy bone marrow cells. The studied epigenetics targeted nanomedicine approach is a promising therapeutic strategy against various French-American-British classes of acute myeloid leukemia. © 2014 Elsevier Inc. All rights reserved.

Biotechnological applications in in vitro plant regeneration studies of broccoli (Brassica oleracea L. var. italica), an important vegetable crop.

Science.gov (United States)

Kumar, Pankaj; Srivastava, Dinesh Kumar

2016-04-01

Biotechnology holds promise for genetic improvement of important vegetable crops. Broccoli (Brassica oleracea L. var. italica) is an important vegetable crop of the family Brassicaceae. However, various biotic and abiotic stresses cause enormous crop yield losses during commercial cultivation of broccoli. Establishment of a reliable, reproducible and efficient in vitro plant regeneration system with cell and tissue culture is a vital prerequisite for biotechnological application of crop improvement programme. An in vitro plant regeneration technique refers to culturing, cell division, cell multiplication, de-differentiation and differentiation of cells, protoplasts, tissues and organs on defined liquid/solid medium under aseptic and controlled environment. Recent progress in the field of plant tissue culture has made this area one of the most dynamic and promising in experimental biology. There are many published reports on in vitro plant regeneration studies in broccoli including direct organogenesis, indirect organogenesis and somatic embryogenesis. This review summarizes those plant regeneration studies in broccoli that could be helpful in drawing the attention of the researchers and scientists to work on it to produce healthy, biotic and abiotic stress resistant plant material and to carry out genetic transformation studies for the production of transgenic plants.

Recognition of Core- and Polymerase-derived immunogenic peptides included in novel therapeutic vaccine by T cells from Chinese chronic hepatitis B patients.

Science.gov (United States)

Huang, D; Sansas, B; Jiang, J H; Gong, Q M; Jin, G D; Calais, V; Yu, D M; Zhu, M Y; Wei, D; Zhang, D H; Inchauspé, G; Zhang, X X; Zhu, R

2017-11-01

Chronic hepatitis B (CHB) is one of the major public health challenges in the world. Due to a strong interplay between specific T-cell immunity and elimination of hepatitis B virus (HBV), efforts to develop novel immunotherapeutics are gaining attention. TG1050, a novel immunotherapy, has shown efficacy in an animal study. To support the clinical development of TG1050 in China, specific immunity to the fusion antigens of TG1050 was assessed in Chinese patients. One hundred and thirty subjects were divided into three groups as CHB patients, HBV spontaneous resolvers, and CHB patients with HBsAg loss after antiviral treatment. HBV-specific T-cell responses to pools of HBV Core or Polymerase genotype D peptides included in TG1050 were evaluated. HBV Core- or Polymerase-specific cells were detected in peripheral blood mononuclear cells (PBMCs) from the different cohorts. The frequencies and intensities of HBV Core-specific immune responses were significantly lower in CHB patients than in HBsAg loss subjects. In CHB patients, a dominant pool derived from Polymerase (Pol1) was the most immunogenic. CHB patients with low viral loads (Core peptide pool. Overall, genotype D-derived peptides included in TG1050 could raise broad and functional T-cell responses in PBMCs from Chinese CHB patients infected with genotype B/C isolates. Core-specific immunogenic domains appeared as "hot spots" with the capacity to differentiate between CHB vs HBsAg loss subjects. These observations support the extended application and associated immune monitoring of TG1050 in China. © 2017 The Authors. Journal of Viral Hepatitis Published by John Wiley & Sons Ltd.

Development method of Hybrid Energy Storage System, including PEM fuel cell and a battery

Science.gov (United States)

Ustinov, A.; Khayrullina, A.; Borzenko, V.; Khmelik, M.; Sveshnikova, A.

2016-09-01

Development of fuel cell (FC) and hydrogen metal-hydride storage (MH) technologies continuously demonstrate higher efficiency rates and higher safety, as hydrogen is stored at low pressures of about 2 bar in a bounded state. A combination of a FC/MH system with an electrolyser, powered with a renewable source, allows creation of an almost fully autonomous power system, which could potentially replace a diesel-generator as a back-up power supply. However, the system must be extended with an electro-chemical battery to start-up the FC and compensate the electric load when FC fails to deliver the necessary power. Present paper delivers the results of experimental and theoretical investigation of a hybrid energy system, including a proton exchange membrane (PEM) FC, MH- accumulator and an electro-chemical battery, development methodology for such systems and the modelling of different battery types, using hardware-in-the-loop approach. The economic efficiency of the proposed solution is discussed using an example of power supply of a real town of Batamai in Russia.

Development method of Hybrid Energy Storage System, including PEM fuel cell and a battery

International Nuclear Information System (INIS)

Ustinov, A; Khayrullina, A; Khmelik, M; Sveshnikova, A; Borzenko, V

2016-01-01

Development of fuel cell (FC) and hydrogen metal-hydride storage (MH) technologies continuously demonstrate higher efficiency rates and higher safety, as hydrogen is stored at low pressures of about 2 bar in a bounded state. A combination of a FC/MH system with an electrolyser, powered with a renewable source, allows creation of an almost fully autonomous power system, which could potentially replace a diesel-generator as a back-up power supply. However, the system must be extended with an electro-chemical battery to start-up the FC and compensate the electric load when FC fails to deliver the necessary power. Present paper delivers the results of experimental and theoretical investigation of a hybrid energy system, including a proton exchange membrane (PEM) FC, MH- accumulator and an electro-chemical battery, development methodology for such systems and the modelling of different battery types, using hardware-in-the-loop approach. The economic efficiency of the proposed solution is discussed using an example of power supply of a real town of Batamai in Russia. (paper)

The zinc-finger transcription factor SALL4 is frequently expressed in human cancers: association with clinical outcome in squamous cell carcinoma but not in adenocarcinoma of the esophagus.

Science.gov (United States)

Kilic, Ergin; Tennstedt, Pierre; Högner, Anica; Lebok, Patrick; Sauter, Guido; Bokemeyer, Carsten; Izbicki, Jakob R; Wilczak, Waldemar

2016-04-01

SALL4 is a transcription factor originally identified as a homeotic gene essential for organ development. Early studies suggested that SALL4 is a useful marker to identify testicular and ovarian germ cell tumors. The aim of the study was to evaluate the diagnostic potential of SALL4 immunohistochemistry. Immunohistochemical staining was performed on a tissue microarray (TMA) with 3966 samples from 94 different tumor types and on a further TMA with 492 esophagus carcinomas. SALL4 immunostaining was by far most prevalent and most intensive in testicular tumors with a positivity rate of 93.1% in seminomas, 80% in mixed germ cell tumors (embryonic carcinomas/yolk sac tumors), and 18.5% in teratomas, respectively. However, SALL4 expression is not specific to germ cell tumors. We observed SALL4 positivity in non-germ cell tumors as carcinomas of the kidney (28.9% of chromophobe, 34.4% of clear cell carcinoma), in intestinal type adenocarcinoma of the stomach (10.9%), in adenocarcinoma (10.5%) and squamous cell carcinoma (7.2%) of the esophagus, and in malignant melanoma (8.1%) and invasive urothelial bladder carcinoma (20%). SALL4 expression was not found in lymphomas, in soft tissue tumors or breast tumors. At analysis of esophagus carcinoma TMA, no significant association was seen between SALL4 expression and overall survival in adenocarcinoma. However, SALL4 expression was strongly associated with worse overall survival in squamous cell carcinoma. SALL4 expression can be found at relevant frequencies in various tumors of different primary sites. SALL4 expression in squamous cell carcinoma of the esophagus may constitute a sign of dedifferentiation leading to poor patient prognosis.

A reliable protocol for the isolation of viable, chondrogenically differentiated human mesenchymal stem cells from high-density pellet cultures.

Science.gov (United States)

Ullah, Mujib; Hamouda, Houda; Stich, Stefan; Sittinger, Michael; Ringe, Jochen

2012-12-01

Administration of chondrogenically differentiated mesenchymal stem cells (MSC) is discussed as a promising approach for the regenerative treatment of injured or diseased cartilage. The high-density pellet culture is the standard culture for chondrogenic differentiation, but cells in pellets secrete extracellular matrix (ECM) that they become entrapped in. Protocols for cell isolation from pellets often result in cell damage and dedifferentiation towards less differentiated MSC. Therefore, our aim was to develop a reliable protocol for the isolation of viable, chondrogenically differentiated MSC from high-density pellet cultures. Human bone marrow MSC were chondrogenically stimulated with transforming growth factor-β3, and the cartilaginous structure of the pellets was verified by alcian blue staining of cartilage proteoglycans, antibody staining of cartilage collagen type II, and quantitative real-time reverse-transcription polymerase chain reaction of the marker genes COL2A1 and SOX9. Trypsin and collagenases II and P were tested alone or in combination, and for different concentrations and times, to find a protocol for optimized pellet digestion. Whereas trypsin was not able to release viable cells, 90-min digestion with 300 U of collagenase II, 20 U of collagenase P, and 2 mM CaCl2 worked quite well and resulted in about 2.5×10(5) cells/pellet. The protocol was further optimized for the separation of released cells and ECM from each other. Cells were alcian blue and collagen type II positive and expressed COL2A1 and SOX9, verifying a chondrogenic character. However, they had different morphological shapes. The ECM was also uniformly alcian blue and collagen type II positive but showed different organizational and structural forms. To conclude, our protocol allows the reliable isolation of a defined number of viable, chondrogenically differentiated MSC from high-density pellet cultures. Such cells, as well as the ECM components, are of interest as

Nuclear import mechanism for myocardin family members and their correlation with vascular smooth muscle cell phenotype.

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Nakamura, Seiji; Hayashi, Ken'ichiro; Iwasaki, Kazuhiro; Fujioka, Tomoaki; Egusa, Hiroshi; Yatani, Hirofumi; Sobue, Kenji

2010-11-26

Myocardin (Mycd), which is essential for the differentiation of the smooth muscle cell lineage, is constitutively located in the nucleus, although its family members, myocardin-related transcription factors A and B (MRTF-A/B), mostly reside in the cytoplasm and translocate to the nucleus in response to Rho signaling. The mechanism for their nuclear import is unclear. Here we investigated the mechanism for the nuclear import of Mycd family members and demonstrated any correlation between such mechanism and the phenotype of vascular smooth muscle cells (VSMCs). In cultured VSMCs, the knockdown of importin β1 inhibited the nuclear import of Mycd and MRTF-A/B. Their NH(2)-terminal basic domain was identified as a binding site for importin α/β1 by in vitro analyses. However, Mycd had a higher affinity for importin α/β1 than did MRTF-A/B, even in the absence of G-actin, and Mycd affinity for importin α1/β1 was stronger than for any other importin α/β1 heterodimers. The binding of Mycd to importin α/β1 was insensitive to G-actin, whereas that of MRTF-A/B was differently inhibited by G-actin. In dedifferentiated VSMCs, the levels of importins α1 and β1 were reduced concomitant with down-regulation of Mycd, serum response factor, and smooth muscle cell markers. By contrast, in differentiated VSMCs, their expressions were up-regulated. Thus, the nuclear import of Mycd family members in VSMCs depends on importin α/β1, and their relative affinities for importin α/β1 heterodimers determine Mycd nuclear import. The expression of Mycd nuclear import machineries is related to the expression levels of VSMC phenotype-dependent smooth muscle cell markers.

Side-To-Side Nerve Bridges Support Donor Axon Regeneration Into Chronically Denervated Nerves and Are Associated With Characteristic Changes in Schwann Cell Phenotype.

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Hendry, J Michael; Alvarez-Veronesi, M Cecilia; Snyder-Warwick, Alison; Gordon, Tessa; Borschel, Gregory H

2015-11-01

Chronic denervation resulting from long nerve regeneration times and distances contributes greatly to suboptimal outcomes following nerve injuries. Recent studies showed that multiple nerve grafts inserted between an intact donor nerve and a denervated distal recipient nerve stump (termed "side-to-side nerve bridges") enhanced regeneration after delayed nerve repair. To examine the cellular aspects of axon growth across these bridges to explore the "protective" mechanism of donor axons on chronically denervated Schwann cells. In Sprague Dawley rats, 3 side-to-side nerve bridges were placed over a 10-mm distance between an intact donor tibial (TIB) nerve and a recipient denervated common peroneal (CP) distal nerve stump. Green fluorescent protein-expressing TIB axons grew across the bridges and were counted in cross section after 4 weeks. Immunofluorescent axons and Schwann cells were imaged over a 4-month period. Denervated Schwann cells dedifferentiated to a proliferative, nonmyelinating phenotype within the bridges and the recipient denervated CP nerve stump. As donor TIB axons grew across the 3 side-to-side nerve bridges and into the denervated CP nerve, the Schwann cells redifferentiated to the myelinating phenotype. Bridge placement led to an increased mass of hind limb anterior compartment muscles after 4 months of denervation compared with muscles whose CP nerve was not "protected" by bridges. This study describes patterns of donor axon regeneration and myelination in the denervated recipient nerve stump and supports a mechanism where these donor axons sustain a proregenerative state to prevent deterioration in the face of chronic denervation.

Intrinsic and extrinsic molecular determinants or modulators for epigenetic remodeling and reprogramming of somatic cell-derived genome in mammalian nuclear-transferred oocytes and resultant embryos.

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Samiec, M; Skrzyszowska, M

2018-03-01

The efficiency of somatic cell cloning in mammals remains disappointingly low. Incomplete and aberrant reprogramming of epigenetic memory of somatic cell nuclei in preimplantation nuclear- transferred (NT) embryos is one of the most important factors that limit the cloning effectiveness. The extent of epigenetic genome-wide alterations, involving histone or DNA methylation and histone deacetylation, that are mediated by histone-lysine methyltransferases (HMTs) or DNA methyltransferases (DNMTs) and histone deacetylases (HDACs) can be modulated/reversed via exogenous inhibitors of these enzymes throughout in vitro culture of nuclear donor cells, nuclear recipient oocytes and/or cloned embryos. The use of the artificial modifiers of epigenomically-conditioned gene expression leads to inhibition of both chromatin condensation and transcriptional silencing the genomic DNA of somatic cells that provide a source of nuclear donors for reconstruction of enucleated oocytes and generation of cloned embryos. The onset of chromatin decondensation and gene transcriptional activity is evoked both through specific/selective inactivating HMTs by BIX-01294 and through non-specific/non-selective blocking the activity of either DNMTs by 5-aza-2'-deoxycytidine, zebularine, S-adenosylhomocysteine or HDACs by trichostatin A, valproic acid, scriptaid, oxamflatin, sodium butyrate, m-carboxycinnamic acid bishydroxamide, panobinostat, abexinostat, quisinostat, dacinostat, belinostat and psammaplin A. Epigenomic modulation of nuclear donor cells, nuclear recipient cells and/or cloned embryos may facilitate and accelerate the reprogrammability for gene expression of donor cell nuclei that have been transplanted into a host ooplasm and subsequently underwent dedifferentiating and re-establishing the epigenetically dependent status of their transcriptional activity during pre- and postimplantation development of NT embryos. Nevertheless, a comprehensive additional work is necessary to determine

Differentiation of mesenchymal stem cells for cartilage tissue engineering: Individual and synergetic effects of three-dimensional environment and mechanical loading.

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Panadero, J A; Lanceros-Mendez, S; Ribelles, J L Gomez

2016-03-01

Chondrogenesis of dedifferentiated chondrocytes and mesenchymal stem cells is influenced not only by soluble molecules like growth factors, but also by the cell environment itself. The latter is achieved through both mechanical cues - which act as stimulation factor and influences nutrient transport - and adhesion to extracellular matrix cues - which determine cell shape. Although the effects of soluble molecules and cell environment have been intensively addressed, few observations and conclusions about the interaction between the two have been achieved. In this work, we review the state of the art on the single effects between mechanical and biochemical cues, as well as on the combination of the two. Furthermore, we provide a discussion on the techniques currently used to determine the mechanical properties of materials and tissues generated in vitro, their limitations and the future research needs to properly address the identified problems. The importance of biomechanical cues in chondrogenesis is well known. This paper reviews the existing literature on the effect of mechanical stimulation on chondrogenic differentiation of mesenchymal stem cells in order to regenerate hyaline cartilage. Contradictory results found with respect to the effect of different modes of external loading can be explained by the different properties of the scaffolding system that holds the cells, which determine cell adhesion and morphology and spatial distribution of cells, as well as the stress transmission to the cells. Thus, this review seeks to provide an insight into the interplay between external loading program and scaffold properties during chondrogenic differentiation. The review of the literature reveals an important gap in the knowledge in this field and encourages new experimental studies. The main issue is that in each of the few cases in which the interplay is investigated, just two groups of scaffolds are compared, leaving intermediate adhesion conditions out of study

Adult Mouse DRG Explant and Dissociated Cell Models to Investigate Neuroplasticity and Responses to Environmental Insults Including Viral Infection.

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Fornaro, Michele; Sharthiya, Harsh; Tiwari, Vaibhav

2018-03-09

This protocol describes an ex vivo model of mouse-derived dorsal root ganglia (DRG) explant and in vitro DRG-derived co-culture of dissociated sensory neurons and glial satellite cells. These are useful and versatile models to investigate a variety of biological responses associated with physiological and pathological conditions of the peripheral nervous system (PNS) ranging from neuron-glial interaction, neuroplasticity, neuroinflammation, and viral infection. The usage of DRG explant is scientifically advantageous compared to simplistic single cells models for multiple reasons. For instance, as an organotypic culture, the DRG explant allows ex vivo transfer of an entire neuronal network including the extracellular microenvironment that play a significant role in all the neuronal and glial functions. Further, DRG explants can also be maintained ex vivo for several days and the culture conditions can be perturbed as desired. In addition, the harvested DRG can be further dissociated into an in vitro co-culture of primary sensory neurons and satellite glial cells to investigate neuronal-glial interaction, neuritogenesis, axonal cone interaction with the extracellular microenvironment, and more general, any aspect associated with the neuronal metabolism. Therefore, the DRG-explant system offers a great deal of flexibility to study a wide array of events related to biological, physiological, and pathological conditions in a cost-effective manner.

Tyr phosphatase-mediated P-ERK inhibition suppresses senescence in EIA + v-raf transformed cells, which, paradoxically, are apoptosis-protected in a MEK-dependent manner.

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De Vitis, Stefania; Sonia Treglia, Antonella; Ulianich, Luca; Turco, Stefano; Terrazzano, Giuseppe; Lombardi, Angela; Miele, Claudia; Garbi, Corrado; Beguinot, Francesco; Di Jeso, Bruno

2011-02-01

Activation of the Ras-Raf-extracellular signal-regulated kinase (ERK) pathway causes not only proliferation and suppression of apoptosis but also the antioncogenic response of senescence. How these contrasting effects are reconciled to achieve cell transformation and cancer formation is poorly understood. In a system of two-step carcinogenesis (dedifferentiated PC EIA, transformed PC EIA-polyoma-middle T [PC EIA + Py] and PC EIA-v-raf [PC EIA + raf] cells], v-raf cooperated with EIA by virtue of a strong prosurvival effect, not elicited by Py-middle T, evident toward serum-deprivation-and H(2)O(2)-induced apoptosis. Apoptosis was detected by DNA fragmentation and annexin V staining. The prosurvival function of v-raf was, in part, mitogen-activated protein kinase/ERK kinase (MEK)-dependent, as shown by pharmacological MEK inhibition. The MEK-dependent antiapoptotic effect of v-raf was exerted despite a lower level of P-ERK1/2 in EIA + raf cells with respect to EIA + Py/EIA cells, which was dependent on a high tyrosine phosphatase activity, as shown by orthovanadate blockade. An ERK1/2 tyrosine phosphatase was likely involved. The high tyrosine phosphatase activity was instrumental to the complete suppression of senescence, detected by β-galactosidase activity, because tyrosine phosphatase blockade induced senescence in EIA + raf but not in EIA + Py cells. High tyrosine phosphatase activity and evasion from senescence were confirmed in an anaplastic thyroid cancer cell line. Therefore, besides EIA, EIA + raf cells suppress senescence through a new mechanism, namely, phosphatase-mediated P-ERK1/2 inhibition, but, paradoxically, retain the oncogenic effects of the Raf-ERK pathway. We propose that the survival effect of Raf is not a function of absolute P-ERK1/2 levels at a given time but is rather dynamically dependent on greater variations after an apoptotic stimulus.

Tyr Phosphatase-Mediated P-ERK Inhibition Suppresses Senescence in EIA + v-raf Transformed Cells, Which, Paradoxically, Are Apoptosis-Protected in a MEK-Dependent Manner

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Stefania De Vitis

2011-02-01

Full Text Available Activation of the Ras-Raf-extracellular signal-regulated kinase (ERK pathway causes not only proliferation and suppression of apoptosis but also the antioncogenic response of senescence. How these contrasting effects are reconciled to achieve cell transformation and cancer formation is poorly understood. In a system of two-step carcinogenesis (dedifferentiated PC EIA, transformed PC EIA-polyoma-middle T [PC EIA + Py] and PC EIA-v-raf [PC EIA + raf] cells], v-raf cooperated with EIA by virtue of a strong prosurvival effect, not elicited by Py-middle T, evident toward serum-deprivation-and H2O2-induced apoptosis. Apoptosis was detected by DNA fragmentation and annexin V staining. The prosurvival function of v-raf was, in part, mitogen-activated protein kinase/ERK kinase (MEK-dependent, as shown by pharmacological MEK inhibition. The MEK-dependent antiapoptotic effect of v-raf was exerted despite a lower level of P-ERK1/2 in EIA + raf cells with respect to EIA + Py/EIA cells, which was dependent on a high tyrosine phosphatase activity, as shown by orthovanadate blockade. An ERK1/2 tyrosine phosphatase was likely involved. The high tyrosine phosphatase activity was instrumental to the complete suppression of senescence, detected by β-galactosidase activity, because tyrosine phosphatase blockade induced senescence in EIA + raf but not in EIA + Py cells. High tyrosine phosphatase activity and evasion from senescence were confirmed in an anaplastic thyroid cancer cell line. Therefore, besides EIA, EIA + raf cells suppress senescence through a new mechanism, namely, phosphatase-mediated P-ERK1/2 inhibition, but, paradoxically, retain the oncogenic effects of the Raf-ERK pathway. We propose that the survival effect of Raf is not a function of absolute P-ERK1/2 levels at a given time but is rather dynamically dependent on greater variations after an apoptotic stimulus.

DNA Methylation Dynamics Regulate the Formation of a Regenerative Wound Epithelium during Axolotl Limb Regeneration.

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Cristian Aguilar

Full Text Available The formation of a blastema during regeneration of an axolotl limb involves important changes in the behavior and function of cells at the site of injury. One of the earliest events is the formation of the wound epithelium and subsequently the apical epidermal cap, which involves in vivo dedifferentiation that is controlled by signaling from the nerve. We have investigated the role of epigenetic modifications to the genome as a possible mechanism for regulating changes in gene expression patterns of keratinocytes of the wound and blastema epithelium that are involved in regeneration. We report a modulation of the expression DNMT3a, a de novo DNA methyltransferase, within the first 72 hours post injury that is dependent on nerve signaling. Treatment of skin wounds on the upper forelimb with decitabine, a DNA methyltransferase inhibitor, induced changes in gene expression and cellular behavior associated with a regenerative response. Furthermore, decitabine-treated wounds were able to participate in regeneration while untreated wounds inhibited a regenerative response. Elucidation of the specific epigenetic modifications that mediate cellular dedifferentiation likely will lead to insights for initiating a regenerative response in organisms that lack this ability.

Thermodynamic Modeling and Dispatch of Distributed Energy Technologies including Fuel Cell -- Gas Turbine Hybrids

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McLarty, Dustin Fogle

Distributed energy systems are a promising means by which to reduce both emissions and costs. Continuous generators must be responsive and highly efficiency to support building dynamics and intermittent on-site renewable power. Fuel cell -- gas turbine hybrids (FC/GT) are fuel-flexible generators capable of ultra-high efficiency, ultra-low emissions, and rapid power response. This work undertakes a detailed study of the electrochemistry, chemistry and mechanical dynamics governing the complex interaction between the individual systems in such a highly coupled hybrid arrangement. The mechanisms leading to the compressor stall/surge phenomena are studied for the increased risk posed to particular hybrid configurations. A novel fuel cell modeling method introduced captures various spatial resolutions, flow geometries, stack configurations and novel heat transfer pathways. Several promising hybrid configurations are analyzed throughout the work and a sensitivity analysis of seven design parameters is conducted. A simple estimating method is introduced for the combined system efficiency of a fuel cell and a turbine using component performance specifications. Existing solid oxide fuel cell technology is capable of hybrid efficiencies greater than 75% (LHV) operating on natural gas, and existing molten carbonate systems greater than 70% (LHV). A dynamic model is calibrated to accurately capture the physical coupling of a FC/GT demonstrator tested at UC Irvine. The 2900 hour experiment highlighted the sensitivity to small perturbations and a need for additional control development. Further sensitivity studies outlined the responsiveness and limits of different control approaches. The capability for substantial turn-down and load following through speed control and flow bypass with minimal impact on internal fuel cell thermal distribution is particularly promising to meet local demands or provide dispatchable support for renewable power. Advanced control and dispatch

Human Bronchial Epithelial Cell Response to Heavy Particle Exposure

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Story, Michael; Ding, Liang-Hao; Minna, John; Park, Seong-mi; Peyton, Michael; Larsen, Jill

2012-07-01

A battery of non-oncogenically immortalized human bronchial epithelial cells (HBECs) are being used to examine the molecular changes that lead to lung carcinogenesis after exposure to heavy particles found in the free space environment. The goal is to ultimately identify biomarkers of radioresponse that can be used for prediction of carcinogenic risk for fatal lung cancer. Our initial studies have focused on the cell line HBEC3 KT and the isogenic variant HBEC3 KTR53, which overexpresses the RASv12 mutant and where p53 has been knocked down by shRNA, and is considered to be a more oncogenically progressed variant. We have previously described the response of HBEC3 KT at the cellular and molecular level, however, the focus here is on the rate of cellular transformation after HZE radiation exposure and the molecular changes in transformed cells. When comparing the two cell lines we find that there is a maximum rate of cellular transformation at 0.25 Gy when cells are exposed to 1 GeV Fe particles, and, for the HBEC3 KTR53 there are multiple pathways upregulated that promote anchorage independent growth including the mTOR pathway, the TGF-1 pathway, RhoA signaling and the ERK/MAPK pathway as early as 2 weeks after radiation. This does not occur in the HBEC3 KT cell line. Transformed HBEC3 KT cells do not show any morphologic or phenotypic changes when grown as cell cultures. HBEC3 KTR53 cells on the other hand show substantial changes in morphology from a cobblestone epithelial appearance to a mesenchymal appearance with a lack of contact inhibition. This epithelial to mesenchymal change in morphology is accompanied by the expression of vimentin and a reduction in the expression of E-cadherin, which are hallmarks of epithelial to mesenchymal transition. Interestingly, for HBEC3 KT transformed cells there are no mutations in the p53 gene, 2 of 15 clones were found to be heterozygous for the RASV12 mutation, and 3 of 15 clones expressed high levels of BigH3, a TGFB

Investigation of the performance of fermentation processes using a mathematical model including effects of metabolic bottleneck and toxic product on cells.

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Sriyudthsak, Kansuporn; Shiraishi, Fumihide

2010-11-01

A number of recent research studies have focused on theoretical and experimental investigation of a bottleneck in a metabolic reaction network. However, there is no study on how the bottleneck affects the performance of a fermentation process when a product is highly toxic and remarkably influences the growth and death of cells. The present work therefore studies the effect of bottleneck on product concentrations under different product toxicity conditions. A generalized bottleneck model in a fed-batch fermentation is constructed including both the bottleneck and the product influences on cell growth and death. The simulation result reveals that when the toxic product strongly influences the cell growth and death, the final product concentration is hardly changed even if the bottleneck is removed, whereas it is markedly changed by the degree of product toxicity. The performance of an ethanol fermentation process is also discussed as a case example to validate this result. In conclusion, when the product is highly toxic, one cannot expect a significant increase in the final product concentration even if removing the bottleneck; rather, it may be more effective to somehow protect the cells so that they can continuously produce the product. Copyright © 2010 Elsevier Inc. All rights reserved.

Enteric bacterial metabolites propionic and butyric acid modulate gene expression, including CREB-dependent catecholaminergic neurotransmission, in PC12 cells--possible relevance to autism spectrum disorders.

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Bistra B Nankova

Full Text Available Alterations in gut microbiome composition have an emerging role in health and disease including brain function and behavior. Short chain fatty acids (SCFA like propionic (PPA, and butyric acid (BA, which are present in diet and are fermentation products of many gastrointestinal bacteria, are showing increasing importance in host health, but also may be environmental contributors in neurodevelopmental disorders including autism spectrum disorders (ASD. Further to this we have shown SCFA administration to rodents over a variety of routes (intracerebroventricular, subcutaneous, intraperitoneal or developmental time periods can elicit behavioral, electrophysiological, neuropathological and biochemical effects consistent with findings in ASD patients. SCFA are capable of altering host gene expression, partly due to their histone deacetylase inhibitor activity. We have previously shown BA can regulate tyrosine hydroxylase (TH mRNA levels in a PC12 cell model. Since monoamine concentration is known to be elevated in the brain and blood of ASD patients and in many ASD animal models, we hypothesized that SCFA may directly influence brain monoaminergic pathways. When PC12 cells were transiently transfected with plasmids having a luciferase reporter gene under the control of the TH promoter, PPA was found to induce reporter gene activity over a wide concentration range. CREB transcription factor(s was necessary for the transcriptional activation of TH gene by PPA. At lower concentrations PPA also caused accumulation of TH mRNA and protein, indicative of increased cell capacity to produce catecholamines. PPA and BA induced broad alterations in gene expression including neurotransmitter systems, neuronal cell adhesion molecules, inflammation, oxidative stress, lipid metabolism and mitochondrial function, all of which have been implicated in ASD. In conclusion, our data are consistent with a molecular mechanism through which gut related environmental signals

TGF-β1, GDF-5, and BMP-2 stimulation induces chondrogenesis in expanded human articular chondrocytes and marrow-derived stromal cells.

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Murphy, Meghan K; Huey, Daniel J; Hu, Jerry C; Athanasiou, Kyriacos A

2015-03-01

Replacement of degenerated cartilage with cell-based cartilage products may offer a long-term solution to halt arthritis' degenerative progression. Chondrocytes are frequently used in cell-based FDA-approved cartilage products; yet human marrow-derived stromal cells (hMSCs) show significant translational potential, reducing donor site morbidity and maintaining their undifferentiated phenotype with expansion. This study sought to investigate the effects of transforming growth factor β1 (TGF-β1), growth/differentiation factor 5 (GDF-5), and bone morphogenetic protein 2 (BMP-2) during postexpansion chondrogenesis in human articular chondrocytes (hACs) and to compare chondrogenesis in passaged hACs with that of passaged hMSCs. Through serial expansion, chondrocytes dedifferentiated, decreasing expression of chondrogenic genes while increasing expression of fibroblastic genes. However, following expansion, 10 ng/mL TGF-β1, 100 ng/mL GDF-5, or 100 ng/mL BMP-2 supplementation during three-dimensional aggregate culture each upregulated one or more markers of chondrogenic gene expression in both hACs and hMSCs. Additionally, in both cell types, the combination of TGF-β1, GDF-5, and BMP-2 induced the greatest upregulation of chondrogenic genes, that is, Col2A1, Col2A1/Col1A1 ratio, SOX9, and ACAN, and synthesis of cartilage-specific matrix, that is, glycosaminoglycans (GAGs) and ratio of collagen II/I. Finally, TGF-β1, GDF-5, and BMP-2 stimulation yielded mechanically robust cartilage rich in collagen II and GAGs in both cell types, following 4 weeks maturation. This study illustrates notable success in using the self-assembling method to generate robust, scaffold-free neocartilage constructs using expanded hACs and hMSCs. © 2014 AlphaMed Press.

Cartilage Integration: Evaluation of the reasons for failure of integration during cartilage repair. A review

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IM Khan

2008-09-01

Full Text Available Articular cartilage is a challenging tissue to reconstruct or replace principally because of its avascular nature; large chondral lesions in the tissue do not spontaneously heal. Where lesions do penetrate the bony subchondral plate, formation of hematomas and the migration of mesenchymal stem cells provide an inferior and transient fibrocartilagenous replacement for hyaline cartilage. To circumvent the poor intrinsic reparative response of articular cartilage several surgical techniques based on tissue transplantation have emerged. One characteristic shared by intrinsic reparative processes and the new surgical therapies is an apparent lack of lateral integration of repair or graft tissue with the host cartilage that can lead to poor prognosis. Many factors have been cited as impeding cartilage:cartilage integration including; chondrocyte cell death, chondrocyte dedifferentiation, the nature of the collagenous and proteoglycan networks that constitute the extracellular matrix, the type of biomaterial scaffold employed in repair and the origin of the cells used to repopulate the defect or lesion. This review addresses the principal intrinsic and extrinsic factors that impede integration and describe how manipulation of these factors using a host of strategies can positively influence cartilage integration.

An improved pre-clinical patient-derived liquid xenograft mouse model for acute myeloid leukemia

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Zhisheng Her

2017-10-01

Full Text Available Abstract Background Xenotransplantation of patient-derived AML (acute myeloid leukemia cells in NOD-scid Il2rγ null (NSG mice is the method of choice for evaluating this human hematologic malignancy. However, existing models constructed using intravenous injection in adult or newborn NSG mice have inferior engraftment efficiency, poor peripheral blood engraftment, or are difficult to construct. Methods Here, we describe an improved AML xenograft model where primary human AML cells were injected into NSG newborn pups intrahepatically. Results Introduction of primary cells from AML patients resulted in high levels of engraftment in peripheral blood, spleen, and bone marrow (BM of recipient mice. The phenotype of engrafted AML cells remained unaltered during serial transplantation. The mice developed features that are consistent with human AML including spleen enlargement and infiltration of AML cells into multiple organs. Importantly, we demonstrated that although leukemic stem cell activity is enriched and mediated by CD34+CD117+ subpopulation, CD34+CD117− subpopulation can acquire CD34+CD117+ phenotype through de-differentiation. Lastly, we evaluated the therapeutic potential of Sorafenib and Regorafenib in this AML model and found that periphery and spleen AML cells are sensitive to these treatments, whereas BM provides a protective environment to AML. Conclusions Collectively, our improved model is robust, easy-to-construct, and reliable for pre-clinical AML studies.