198 ISOLATION, CHARACTERIZATION, AND IN VITRO DIFFERENTIATION OF GOAT ADIPOSE-TISSUE-DERIVED MESENCHYMAL STEM CELLS INTO PANCREATIC ISLETS-LIKE CELLS

Abstract

The present study was carried out for isolation of goat (Capra hircus) adipose-tissue-derived stem cells (gADSCs) from adipose tissue, their characterization, and in vitro differentiation of gADSCs into pancreatic islets-like cells by giving conditioned medium. Goat ADSCs were isolated from goat adipose tissue by the enzymatic digestion method and were enriched by filtering through a 41-μm filter. Thus, filtered cells resuspended in a cell culture flask containing growth enriching medium and cultured in 5% CO₂ in air at 38.5°C. Goat ADSCs were characterised by amplification of mesenchymal stem cell specific markers i.e. CD29, CD34, CD44, CD90, and CD166 as positive markers and CD41 and CD71 as negative markers. Immunocytochemistry of mesenchymal stem cell was also carried out with specific markers CD44 and CD90. Goat ADSCs were further characterised by in vitro differentiating them into osteocytes, chondrocytes, and adipocytes. For in vitro differentiation of gADSCs into osteocytes gADSCs were supplemented with conditioned medium i.e. DMEM containing fetal bovine serum (FBS), dexamethazone, B-glycerol phosphate and L-ascorbic acid. Osteogenic differentiation was confirmed by positive Alizarin red S staining and amplification of Osteopontin and Collagen I genes. For differentiation into chondrocytes cells, gADSCs were incubated in DMEM/F12 containing dexamethazone, ITX, BMP-4, and FBS for 21 days. Differentiated cells were confirmed by positive Safranin O staining and expression of chondrocytes specific Collagen III and Aggrecan genes. For adipogenesis, gADSCs were incubated with DMEM/F12 containing FBS, dexamethasone, and ITX and differentiated cells were confirmed by positive Oil Red O staining and amplification of adipocytes specific genes i.e. LPL, PPRγ and PPRα. For in-vitro differentiation gADSCs into pancreatic islets-like cells on the third or fourth passage gADSCs were incubated in conditioned medium containing serum-free DMEM/F12 medium with glucose (17.5 mM) in the presence of nicotinamide (10 mM), activin-A (2 nM), exendin-4 (10 nM), pentagastrin (10 nM), retinoic acid (10 μM) and mercaptoethanol (20 μM). The in vitro differentiation gADSCs into pancreatic islets-like cells was confirmed by amplification of pancreatic endoderm specific genes i.e. igf-1, sst, ngn3, pdx-1, isl-1, c-kit, thy-1, and Glut-2, and no expression was detected for above endoderm specific genes in undifferentiated gADSCs. Pancreatic islets-like cells were further characterised by immunostaining and Western blotting of Pdx-1, insulin, and Islets-1 specific protein. It could be concluded that gADSCs was differentiated into different lineages and secretory insulin was produced from pancreatic islets-like cells.