RIP1 Regulates Mitochondrial Fission during Skeletal Muscle Ischemia Reperfusion Injury

Abstract

Background

Dynamin related protein-1 (Drp1)-mediated mitochondrial fission relates to ischemia reperfusion (IR) injury, and its association with necroptosis is implied. We hypothesized that receptor-interacting protein 1 (RIP1), a key kinase in necroptosis, acted as an upstream of Drp1-mediated mitochondrial fission during skeletal muscle IR.

Methods

Thirty rats were randomized into the SM, IR, NI, MI, and DI group (n = 6). The rats in the SM group were shamly operated, and those in the IR group were subjected to 4-hour ischemia of the right hindlimb that was followed by 4-hour reperfusion. Intraperitoneal administration of Nec-1 1 mg/kg, Mdivi-1 1.2 mg/kg and same volume of DMSO were given before ischemia in the NI, MI and DI groups, respectively. Upon reperfusion, the soleus muscles were harvested to determine morphological changes and the expression of RIP1, total Drp1 and p-Drp1 (Ser616). Moreover, the muscular oxidative stress indicators and plasma muscle damage biomarkers were detected.

Results

IR led to impaired histopathological structures and mitochondrial fragmentation in the soleus muscle tissue, accompanied with increased muscular oxidative stress and muscle injury biomarkers, which could be similarly alleviated by Mdivi-1 and Nec-1 (p < 0.05). RIP1 and p-Drp1 (Ser616) protein levels were significantly upregulated in the soleus muscle subjected to IR injury, this upregulation was attenuated in the NI group, and Mdivi-1 downregulated the protein expression of p-Drp1 (Ser616) but not of RIP1 (p < 0.05).

Conclusion

RIP1 functions as an upstream of Drp1-mediated mitochondrial fission in the execution of necroptosis during skeletal muscle IR.

Keywords:

• Reperfusion injury
• dynamin related protein-1
• mitochondrial fission
• receptor-interacting protein 1
• necroptosis
• skeletal muscle

Acknowledgements

None.

Disclosure statement

The authors report there are no competing interests to declare.

Data availability statement

The data that support the findings of this study are available from the corresponding author, Liangrong Wang, upon reasonable request.

Additional information

Funding

This work was supported by the Foundation of Science and Technology Bureau of Wenzhou City under Grant No. Y20180123.