Xuebijing injection protects sepsis induced myocardial injury by mediating TLR4/NF-κB/IKKα and JAK2/STAT3 signaling pathways

OBJECTIVE

Compelling evidence has demonstrated that Xuebijing (XBJ) exerted protective effects against SIMI. The aims of this study were to investigate whether TLR4/IKKα-mediated NF-κB and JAK2/STAT3 pathways were involved in XBJ's cardio-protection during sepsis and the mechanisms.

METHODS

In this study, rats were randomly assigned to three groups: Sham group; CLP group; XBJ group. Rats were treated with XBJ or sanitary saline after CLP. Echocardiography, myocardial enzymes and HE were used to detect cardiac function. IL-1β, IL-6 and TNF-α in serum were measured using ELISA kits. Cardiomyocyte apoptosis were tested by TUNEL staining. The protein levels of Bax, Bcl-2, Bcl-xl, Cleaved-Caspase 3, Cleaved-Caspase 9, Cleaved-PARP, TLR4, p-NF-κB, p-IKKα, p-JAK2 and p-STAT3 in the myocardium were assayed by western blotting. And finally, immunofluorescence was used to assess the level of p-JAK2 and p-STAT3 in heart tissue.

RESULTS

The results of echocardiography, myocardial enzyme and HE test showed that XBJ could significantly improve SIMI. The IL-1β, IL-6 and TNF-α levels in the serum were markedly lower in the XBJ group than in the CLP group (p<0.05). TUNEL staining's results showed that XBJ ameliorated CLP-induced cardiomyocyte apoptosis. Meanwhile, XBJ downregulated the protein levels of Bax, Cleaved-Caspase 3, Cleaved-Caspase 9, Cleaved-PARP, TLR4, p-NF-κB, p-IKKα, p-JAK2 and p-STAT3, as well as upregulated the protein levels of Bcl-2, Bcl-xl (p <0.05).

CONCLUSIONS

In here, we observed that XBJ's cardioprotective advantages may be attributable to its ability to suppress inflammation and apoptosis via inhibiting the TLR4/ IKKα-mediated NF-κB and JAK2/STAT3 pathways during sepsis.

Xuebijing injection protects against sepsis induced myocardial injury by regulating apoptosis and autophagy via mediation of PI3K/AKT/mTOR signaling pathway in rats

OBJECTIVE

Apoptosis and autophagy are significant factors of sepsis induced myocardial injury (SIMI). XBJ improves SIMI by PI3K/AKT/mTOR pathway. Present study is devised to explore the protective mechanism of XBJ in continuous treatment of SIMI caused by CLP.

METHODS

Rat survival was first recorded within 7 days. Rats were randomly assigned to three groups: Sham group, CLP group, and XBJ group. The animals in each group were divided into 12 h group, 1 d, 2 d, 3 d and 5 d according to the administration time of 12 hours, 1 day, 2 days, 3 days or 5 days, respectively. Echocardiography, myocardial injury markers and H&E staining were used to detect cardiac function and injury. IL-1β, IL-6 and TNF-α in serum were measured using ELISA kits. Cardiomyocyte apoptosis was assayed by TUNEL staining. Apoptosis and autophagy related proteins regulated by the PI3K/AKT/mTOR signaling pathway were tested using western blot.

RESULTS

XBJ increased the survival rate in CLP-induced septic Rat. First of all, the results of echocardiography, H&E staining and myocardial injury markers (cTnI, CK, and LDH levels) showed that XBJ could effectively improve the myocardial injury caused by CLP with the increase of treatment time. Moreover, XBJ significantly decreased the levels of serum inflammatory cytokines IL-1β, IL-6 and TNF-α in SIMI rats. Meanwhile, XBJ downregulated the expression of apoptosis-related proteins Bax, Cleaved-Caspase 3, Cleaved-Caspase 9, Cytochrome C and Cleaved-PARP, while upregulated the protein levels of Bcl-2 in SIMI rats. And, XBJ upregulated the expression of autophagy related protein Beclin-1 and LC3-II/LC3-I ratio in SIMI rats, whereas downregulated the expression of P62. Finally, XBJ administration downregulated the phosphorylation levels of proteins PI3K, AKT and mTOR in SIMI rats.

CONCLUSIONS

Our results showed that XBJ has a good protective effect on SIMI after continuous treatment, and it was speculated that it might be through inhibiting apoptosis and promoting autophagy via, at least partially, activating PI3K/AKT/mTOR pathway in the early stage of sepsis, as well as promoting apoptosis and inhibiting autophagy via suppressing PI3K/AKT/mTOR pathway in the late stage of sepsis.