Article

Platelet-derived growth factor BB mimics serum-induced dispersal of pancreatic epithelial cell clusters.

Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Journal of Cellular Physiology (Impact Factor: 3.87). 10/2013; DOI: 10.1002/jcp.24493
Source: PubMed

ABSTRACT We showed previously that proliferating human islet-derived de-differentiated cells (DIDs) exhibit many characteristics of mesenchymal stem cells. Dispersed DIDs can be induced by serum deprivation to undergo mesenchymal-to-epithelial transition and aggregate into epithelial cell clusters (ECCs). Conversely, ECCs can be induced to disperse and undergo epithelial-to-mesenchymal transition (EMT) by re-addition of mammalian sera. In this study, we show that platelet-derived growth factor BB (PDGF-BB) mimics and mediates serum-induced ECCs' dispersal accompanied by accumulation of cytoplasmic β-catenin and a decrease in the levels of insulin and glucagon mRNAs. Moreover, we show that PDGF-BB-induced dispersal of ECCs is a more general phenomenon that occurs also with bone marrow mesenchymal stem cells (BM-MSCs) and dermal fibroblasts (DFs). In DIDs, BM-MSCs and DFs, PDGF decreased the levels of DKK1 mRNA, suggesting involvement of the Wnt signaling pathway. PDGF-BB stimulated a significant increase in S473 phosphorylation of Akt and the PI3K specific inhibitor (PIP828) partially inhibited PDGF-BB-induced ECC dispersal. Lastly, the PDGF-receptor (PDGF-R) antagonist JNJ-10198409 inhibited both PDGF-BB - and serum-induced ECC dispersal. Epidermal growth factor (EGF), which shares most of the PDGF signaling pathway, did not induce dispersal and only weakly stimulated Akt phosphorylation. Our data suggest that PDGF-BB mediates serum-induced DIDs dispersal, correlated with the activation of the PI3K-Akt pathway. J. Cell. Physiol. © 2013 Wiley Periodicals, Inc.

0 Bookmarks
 · 
56 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Nuclear reprogramming of somatic tissue enables derivation of induced pluripotent stem (iPS) cells from an autologous, non-embryonic origin. The purpose of this study was to establish efficient protocols for lineage specification of human iPS cells into functional glucose-responsive, insulin-producing progeny. We generated human iPS cells, which were then guided with recombinant growth factors that mimic the essential signaling for pancreatic development. Reprogrammed with four stemness factors, human fibroblasts were here converted into authentic iPS cells. Under feeder-free conditions, fate specification was initiated with activin A and Wnt3a that triggered engagement into definitive endoderm, followed by priming with fibroblast growth factor 10 (FGF10) and KAAD-cyclopamine. Addition of retinoic acid, boosted by the pancreatic endoderm inducer indolactam V (ILV), yielded pancreatic progenitors expressing pancreatic and duodenal homeobox 1 (PDX1), neurogenin 3 (NGN3) and neurogenic differentiation 1 (NEUROD1) markers. Further guidance, under insulin-like growth factor 1 (IGF-1), hepatocyte growth factor (HGF) and N-[N-(3,5-Difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT), was enhanced by glucagon-like peptide-1 (GLP-1) to generate islet-like cells that expressed pancreas-specific markers including insulin and glucagon. Derived progeny demonstrated sustained expression of PDX1, and functional responsiveness to glucose challenge secreting up to 230 pM of C-peptide. A pancreatogenic cocktail enriched with ILV/GLP-1 offers a proficient means to specify human iPS cells into glucose-responsive hormone-producing progeny, refining the development of a personalized platform for islet-like cell generation.
    Gene therapy 11/2010; 18(3):283-93. · 4.75 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Diabetes mellitus is characterized by either the inability to produce insulin (type 1 diabetes) or as insensitivity to insulin secreted by the body (type 2 diabetes). In either case, the body is unable to move blood glucose efficiently across cell membranes to be used. This leads to a variety of local and systemic detrimental effects. Current treatments for diabetes focus on exogenous insulin administration and dietary control. Here, we describe a potential cure for diabetes using a cellular therapy to ameliorate symptoms associated with both reduced insulin secretion and insulin sensitivity. Using induced pluripotent stem (iPS) cells, we were able to derive beta-like cells similar to the endogenous insulin-secreting cells in mice. These beta-like cells secreted insulin in response to glucose and corrected a hyperglycemic phenotype in two mouse models of type 1 and 2 diabetes via an iPS cell transplant. Long-term correction of hyperglycemia was achieved, as determined by blood glucose and hemoglobin A1c levels. These data provide an initial proof of principle for potential clinical applications of reprogrammed somatic cells in the treatment of diabetes type 1 or 2.
    Proceedings of the National Academy of Sciences 07/2010; 107(30):13426-31. · 9.81 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The adult pancreas has considerable capacity to regenerate in response to injury. We hypothesized that after partial pancreatectomy (Px) in adult rats, pancreatic-duct cells serve as a source of regeneration by undergoing a reproducible dedifferentiation and redifferentiation. We support this hypothesis by the detection of an early loss of the ductal differentiation marker Hnf6 in the mature ducts, followed by the transient appearance of areas composed of proliferating ductules, called foci of regeneration, which subsequently form new pancreatic lobes. In young foci, ductules express markers of the embryonic pancreatic epithelium - Pdx1, Tcf2 and Sox9 - suggesting that these cells act as progenitors of the regenerating pancreas. The endocrine-lineage-specific transcription factor Neurogenin3, which is found in the developing embryonic pancreas, was transiently detected in the foci. Islets in foci initially resemble embryonic islets in their lack of MafA expression and lower percentage of beta-cells, but with increasing maturation have increasing numbers of MafA(+) insulin(+) cells. Taken together, we provide a mechanism by which adult pancreatic duct cells recapitulate aspects of embryonic pancreas differentiation in response to injury, and contribute to regeneration of the pancreas. This mechanism of regeneration relies mainly on the plasticity of the differentiated cells within the pancreas.
    Journal of Cell Science 08/2010; 123(Pt 16):2792-802. · 5.33 Impact Factor

Full-text

Download
12 Downloads
Available from
Nov 19, 2014