Hydrogen Sulfide Improves Hyperhomocysteinemia‐Mediated Impairment of Angiogenesis in Skeletal Muscle

Abstract

The growth of new blood vessels (angiogenesis) is a fundamental process of human health to satisfy energy requirements, tissue growth, and wound healing. Although hyperhomocysteinemia (HHcy) (~5% of general population) is associated with myopathy, the precise molecular mechanism(s) remain unknown. In this study, we examined the potential effects of HHcy on impairment of angiogenesis in skeletal muscle by antagonizing the angiogenic signals via PI3K/AKT pathway. We used skeletal muscle from WT (C57BL/6J) and HHcy CBS (+/−) mouse model (8 to 10 weeks) and hind limb ischemia were carried out via femoral artery ligation to study the process of angiogenesis. Mice were treated with the H2S donor: NaHS (10 mg/kg) intraperitoneally. After 7, 14 and 21 days of hindlimb ischemia surgery, barium sulfate angiography, immune staining for CD31 and laser Doppler blood flow measurement were carried out in skeletal muscle of both ischemic and the contralateral leg (sham control). Whereas, the expression of all angiogenic factors was analyzed by angiogenic protein array and subsequently confirmed by western blots analysis. We found that the vessel density was significantly less in post-surgery CBS mice compared to WT mice and these effects of HHcy were mitigated via NaHS treatment in a time-dependent manner. The levels of angiogenic factors like hypoxia inducing factor (HIF1-α), growth factors (VEGF), the vasodilator (NO) and structural protein (dystrophin) was significantly attenuated in skeletal muscle of CBS mice in comparison to WT mice, which was improved by NaHS treatment. We also noticed the Akt-phosphorylation was decreased in CBS mice compared to WT mice. These results suggest that HHcy can inhibit angiogenesis via antagonizing the angiogenic signals by interfering PI3K/AKT pathway and NaHS treatment can mitigate these effects of HHcy. We are currently studying whether the outlined processes resulted in myopathy via poor angiogenic development in skeletal muscle during HHcy. Support or Funding Information This work was supported, in part, by a grant from the National Institute of Health (Heart, Lung, and Blood Institute; No. HL-74815). Proposed model This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.