Bcl-xL, Bax, and caspase-3 immunoexpression in mesenchymal stem cells of rat bone marrow and adipose tissue subjected to chondrogenic differentiation with and without triiodothyronine: comparative study

ABSTRACT This study aims to evaluate and compare the Bcl-xL, Bax, and caspase-3 immunoexpression in rat mesenchymal stem cells (bone marrow [BM-MSC] and adipose tissue [ASC]) with and without in vitro triiodothyronine (T3) during chondrogenic differentiation. The MSC were subjected to chondrogenic differentiation for 21 days without (control group) and with different concentrations of T3 (0.01, 1, 100, and 1000nM). Thereafter, Bcl-xL, Bax, and caspase-3 expressions were performed by immunohistochemistry (IHC) and performed using Image J. The data were examined by Shapiro Wilk test, Tukey and t-test. The T3 concentrations of 0.01, 1, and 100 nM significantly reduced Bcl-xL expression in BM-MSC but increased in ASC at 0.01nM. The 0.01 and 100nM T3 increased Bax expression in BM-MSC, whereas 1000nM increased it in ASC. Caspase-3 expression in BM-MSC is not influenced by T3 but was significantly reduced in ASC at 1 and 1000nM of T3. Comparing the two MSC sources, Bax and caspase-3 expressions were significantly higher on T3-exposed BM-MSC when compared with ASC during chondrogenic differentiation. T3 reduces Bcl-xL expression, increases Bax expression, and does not alter caspase-3 expression in BM-MSC and increases Bcl-xL and Bax expression and reduces caspase-3 expression in ASC.