Alteration of gene expression levels during osteog

Authors: Wan Kamarul Zaman Wan Safwani Suzana Makpol Somasundaram Sathapan Kien Hui Chua

Publish Date: 2012/04/05

Volume: 14, Issue: 2, Pages: 289-301

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Abstract

Adipose tissue is a source of multipotent stem cells and it has the ability to differentiate into several types of cell lineages such as neuron cells osteogenic and adipogenic cells Most studies on human adiposederived stem cells ASCs have been carried out at the early passages For clinical usage ASCs need to be expanded in vitro for a period of time to get sufficient cells for transplantation into patients However the impact of longterm culture on ASCs molecular characteristics has not been established yet Several studies have also shown that osteogenic and adipogenic cells have the ability to switch pathways during in vitro culture as they share the same progenitor cells This data is important to ensure their functionality and efficacy before being used clinically in the treatment of bone diseases Therefore we aim to investigate the effect of longterm culture on the adipogenic stemness and osteogenic genes expression during osteogenic induction of ASCs In this study the molecular characteristics of ASCs during osteogenic induction in longterm culture was analysed by observing their morphological changes during induction analysis of cell mineralization using Alizarin Red staining and gene expression changes using quantitative RTPCR Morphologically cell mineralization at P20 was less compared to P5 P10 and P15 Adipogenesis was not observed as negative lipid droplets formation was recorded during induction The quantitative PCR data showed that adipogenic genes expression eg LPL and AP2 decreased but PPARγ was increased after osteogenic induction in longterm culture Most stemness genes decreased at P5 and P10 but showed no significant changes at P15 and P20 While most osteogenic genes increased after osteogenic induction at all passages When compared among passages after induction Runx showed a significant increased at P20 while BSP OSP and ALP decreased at later passage P15 and P20 During longterm culture ASCs were only able to differentiate into immature osteogenic cells

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