OBJECTIVETo explore the effects of ICAM-1 gene transfection on the differentiation of MSCs to adipocytes.

METHODSThe recombinant retroviral expression plasmid MIGR1-ICAM-1 containing full length of mouse ICAM-1 gene was constructed. The constructed plasmid MIGR1-ICAM-1, empty plasmid MIGR1 and packaging plasmid ECOS were transfected into T293 cell lines and then the supernatant generated from T293 cells were used to infect mouse MSCs cell line C3H10T 1/2. The transfective efficiency was determined by inverted fluorescence microscope, real-time PCR and flow cytometry. Furthermore, ICAM-1 overexpressing MSCs (C3H10T 1/2-ICAM-1) and empty vector transfection MSCs (C3H10T 1/2-MIGR1) were cultured in medium with or without induction reagents, Oil-red-O staining was used to detect the lipid accumulation, and the expression of transcriptional factors C/EBPα and PPARγ, which were key factors in the differentiation of MSCs to adipocytes, were tested by real-time-PCR.

RESULTSThe recombinant retrovirus vector containing mouse ICAM-1 gene was successful constructed. After transfection into MSCs cell line C3H10T 1/2, the overexpression ICAM-1 MSCs cell line (C3H10T 1/2-ICAM-1) and control cell line (C3H10T 1/2-MIGR1) were obtained. Furthermore, these two cell lines were treated without or with adipocytic induction reagents, C3H10T 1/2-ICAM-1 showed significantly lower mRNA expression level for C/EBPα [(1.2 ± 0.7), (2.9 ± 0.9)] and PPARγ [(1557.6 ± 70.2), (7547.0 ± 442.2)] when compared with C3H10T 1/2-MIGR1 [(5.8 ± 0.5), (23.0 ± 2.3) and (2453.0 ± 215.6), (9856.3 ± 542.2)](P < 0.05). Moreover, little lipid droplet and decreased quantity of adipocytes were detected in C3H10T 1/2-ICAM-1 [(3.2 ± 0.5)/well, (12.2 ± 3.8)/well] than that in C3H10T 1/2-MIGR1 [(11.2 ± 0.4)/well, (51.3 ± 2.8)/well] (P < 0.05).

CONCLUSIONOverexpression of ICAM-1 in MSCs can inhibit its adipocytic differentiation.