Objective To investigate the effects and underlying mechanisms of total flavonoids of sarcandra glabra(TFFSG)on bone marrow mesenchymal stem cells(BMSCs)and their derived exosomes in immune thrombo-cytopenia(ITP),with a focus on promoting megakaryocyte differentiation and maturation.Methods BMSCs induced by rabbit anti-rat platelet serum(APS)were divided into five groups:a blank control group,an ITP-BMSCs model group,and three TFFSG intervention groups with low(1.95 μg/mL),medium(3.90 μg/mL),and high doses(7.80 μg/mL).The apoptosis rates and the expression levels of apoptosis-related proteins-B-cell lymphoma 2(Bcl-2),Bcl-2-associated X protein(BAX),and Cysteinyl aspartate-specific proteinase-3(Caspase-3)-were assessed.Exosomes were isolated from the blank control group(NC-BMSCs-Exos),the ITP-BMSCs model group(ITP-BMSCs-Exos),and the medium-dose TFFSG group(TFFSG-BMSCs-Exos).Each group's exosomes(5 μg/mL)were co-cultured with megakaryocytic lineage Dami cells for 96 hours.Flow cytometry was employed to evaluate the expression of megakaryocytic differentiation markers(CD41a,CD42b,CD61)and the proportion of polyploid cells(≥4 N)in each group.Western Blot analysis was conducted to examine the expression of p-MEK1/2,MEK1/2,p-ERK1/2,and ERK1/2 across all groups.Results Compared with the ITP-BMSCs model group,the apoptosis rates in all TFFSG intervention groups were significantly reduced(P<0.01).In the medium-and high-dose TFFSG groups,BAX and Caspase-3 expression levels were markedly downregulated,whereas Bcl-2 expression was upregulated(P<0.05,P<0.01).Compared with the ITP-BMSCs-Exos group,the TFFSG-BMSCs-Exos group demonstrated increased expression of CD41a+,CD42b+,and CD61+,a higher proportion of polyploid cells(≥4 N)(P<0.05),as well as elevated ratios of p-MEK1/2 to MEK1/2 and p-ERK1/2 to ERK1/2(P<0.05).Conclusion TFFSG inhibits apopto-sis of ITP-state BMSCs in vitro and promotes megakaryocyte differentiation and polyploidization maturation through BMSC-derived exosomes by activating the MEK1/2-ERK1/2 signaling pathway.

Objective To investigate the effects and underlying mechanisms of total flavonoids of sarcandra glabra(TFFSG)on bone marrow mesenchymal stem cells(BMSCs)and their derived exosomes in immune thrombo-cytopenia(ITP),with a focus on promoting megakaryocyte differentiation and maturation.Methods BMSCs induced by rabbit anti-rat platelet serum(APS)were divided into five groups:a blank control group,an ITP-BMSCs model group,and three TFFSG intervention groups with low(1.95 μg/mL),medium(3.90 μg/mL),and high doses(7.80 μg/mL).The apoptosis rates and the expression levels of apoptosis-related proteins-B-cell lymphoma 2(Bcl-2),Bcl-2-associated X protein(BAX),and Cysteinyl aspartate-specific proteinase-3(Caspase-3)-were assessed.Exosomes were isolated from the blank control group(NC-BMSCs-Exos),the ITP-BMSCs model group(ITP-BMSCs-Exos),and the medium-dose TFFSG group(TFFSG-BMSCs-Exos).Each group's exosomes(5 μg/mL)were co-cultured with megakaryocytic lineage Dami cells for 96 hours.Flow cytometry was employed to evaluate the expression of megakaryocytic differentiation markers(CD41a,CD42b,CD61)and the proportion of polyploid cells(≥4 N)in each group.Western Blot analysis was conducted to examine the expression of p-MEK1/2,MEK1/2,p-ERK1/2,and ERK1/2 across all groups.Results Compared with the ITP-BMSCs model group,the apoptosis rates in all TFFSG intervention groups were significantly reduced(P<0.01).In the medium-and high-dose TFFSG groups,BAX and Caspase-3 expression levels were markedly downregulated,whereas Bcl-2 expression was upregulated(P<0.05,P<0.01).Compared with the ITP-BMSCs-Exos group,the TFFSG-BMSCs-Exos group demonstrated increased expression of CD41a+,CD42b+,and CD61+,a higher proportion of polyploid cells(≥4 N)(P<0.05),as well as elevated ratios of p-MEK1/2 to MEK1/2 and p-ERK1/2 to ERK1/2(P<0.05).Conclusion TFFSG inhibits apopto-sis of ITP-state BMSCs in vitro and promotes megakaryocyte differentiation and polyploidization maturation through BMSC-derived exosomes by activating the MEK1/2-ERK1/2 signaling pathway.