The Comparative Effect of Plasma Exosomes of Young and Old People on the Expression of BCL-2 and BAX Genes in Hematopoietic Stem Cells

Apoptosis may disrupt differentiation of hematopoietic stem cells (HSCs), which can affect aging. Thus, the main goal of this study was to compare the effect of plasma exosomes from young and old people on the expression of Bcl-2-associated X (BAX) and B-cell lymphoma 2 (BCL-2) genes in the HSCs. Plasma samples were acquired from four elderly adults and four younger adults, referring to Blood Transfusion Organization of Tehran-Iran during August 2022– September 2022.Then, the exosomes of the samples were extracted and analyzed using DLS, TEM, and CD63 surface marker. HSCs were isolated from umbilical cord blood cells. The MTT test was used to assess the viability of exosomes-treated HSCs at doses of 5 and 10 μg/ml. The expression of BAX and BCL-2 genes in the cells was examined using real-time PCR. A one-way analysis of variance (ANOVA) was performed to examine the distinctions among five groups. The viability of HSCs was not affected by the exosomes from young and old people than the control group (P = 0.453). Exosomes from young people (doses 5 and 10 µg/ml) did not have any significant impacts on BAX (P = 0.746, and P = 0.345, respectively) and BCL-2 (P = 0.773, and P = 0.461, respectively) expression in the HSCs compared to the control group. The BAX gene was significantly upregulated and the BCL-2 gene was significantly downregulated after utilizing the exosomes derived from the plasma of elderly individuals (dose 10 µg/ml) compared to the control (P = 0.001, P = 0.002, respectively). The current research shows that aged people's exosomes can increase BAX/ BCL-2 ratio in umbilical cord blood-derived HSCs compared to control and young groups.