Immunomodulatory Gene Expression Profile of Corneal-Limbal Versus Bone Marrow derived Mesenchymal Stem Cells

Abstract

Purpose : Mesenchymal stem cells (MSCs) are responsible for recruiting and modulating various cells that participate in tissue repair and regeneration. Bone marrow is a frequently used source for MSCs, though they have been isolated from other areas of the body, including the cornea. We compared the gene expression of well-known immunomodulatory factors in the corneal limbal derived MSCs (CL-MSC) versus bone marrow derived MSCs (BM-MSC).

Methods : MSCs were isolated from healthy human bone marrow donors or from human corneal limbus from research corneas generously provided by Eversight eye bank. After reaching to confluency, passage 4 cells were growth factor starved overnight and RNA was extracted, reverse transcribed and analyzed with ΔΔCt method by real-time qPCR. TNF-stimulated gene-6 (TSG6), interleukin-1 receptor antagonist (IL1RN), stanniocalcin-1 (STC1), cyclooxygenase-2 (COX2), peroxisome proliferator-activated receptor gamma (PPAR-γ), and indoleamine-pyrrole 2,3-dioxygenase (IDO) gene expression were studied. All experiments were repeated with at least five different donors.

Results : TSG6 mRNA was expressed 2.9 ± 0.8 folds more in CL-MSCs compared to BM-MSCs (P < 0.001). Likewise, there were 36.8 ± 2.1, 15.2 ± 1.6 and 8.2 ± 2.7 fold increase in STC1, COX2 and PPAR-γ mRNA expression in CL-MSCs compared to BM-MSCs, respectively (p value for each comparison < 0.01). No significant expression of IL1RN and IDO was found in either CL-MSCs or BM-MSCs.

Conclusions : At the mRNA level, CL-MSCs express higher levels of TSG6, STC1 and COX2 compared to BM-MSCs. Further investigation is needed to delineate any differences at the protein and prostaglandin level as well.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.