Obestatin can potentially differentiate Wharton’s jelly mesenchymal stem cells into insulin-producing cells

Rana K. El-Asfar, Mohamed M. Kamal, Rania S. Abd EL-Razek, Ebtehal EL-Demerdash, Hala O. El-Mesallamy

In vitro-generation of β-cells from Wharton's jelly mesenchymal stem cells (WJ-MSCs) could provide a potential basis for diabetes mellitus cell therapy. However, the generation of functional insulin-producing cells (IPCs) from WJ-MSCs remains a challenge. Recently, obestatin, a gut hormone, was found to promote β-cell generation from pancreatic precursor cells. Accordingly, we hypothesize that obestatin can induce the differentiation of WJ-MSCs into IPCs. Therefore, the purpose of the current study is to examine the ability of obestatin to generate IPCs in comparison to well-known extrinsic factors that are commonly used in IPCs differentiation protocols from MSCs, namely exendin-4 and glucagon-like peptide-1 (GLP-1). To achieve our aims, WJ-MSCs were isolated, cultured and characterized by immunophenotyping and adipocytes differentiation. Afterwards, WJ-MSCs were induced to differentiate into IPCs using two differentiation protocols incorporating either exendin-4, GLP-1 or obestatin. The pancreatic progenitor marker, nestin and β-cell differentiation markers were assessed by qRT-PCR, while the functionality of the generated IPCs was assessed by glucose-stimulated insulin secretion (GSIS). Our results showed that WJ-MSCs exhibit all the characteristics of MSCs. Interestingly, using obestatin in both the short and long differentiation protocols managed to induce the expression of β-cell markers, similar to exendin-4. In GSIS, IPCs generated using either GLP-1 or obestatin showed higher secretion of insulin as compared to those generated using exendin-4 under low-glucose conditions but failed to show a significant response to increased glucose. These results indicate obestatin can be considered as a novel potential factor to consider for generation of IPCs from WJ-MSCs.