The Mechanism Of Myocardin To Ameliorate Erectile Dysfunction By Elevating CSE-H2S Levels In Diabetic Rats

BACKGROUND&OBJECTIVEDiabetic erectile dysfunction(ED)has a high incidence and is difficult to treat.Myocardin plays an important role in the regulation of smooth muscle cells.The previous basic work of this study showed that Myocardin gene therapy could significantly improve the erectile function of diabetic ED rats,but the specific mechanism is unknown.Some studies have shown that hydrogen sulfide(H2S),a gas signal molecule,has obvious booster effect.It is not clear whether there is a connection between them.The purpose of this study is to explore whether Myocardin gene therapy can improve the erectile function of diabetic ED rats and its mechanism through a series of animal and cell experiments.METHODSThis study is divided into three parts.In the first part,after the construction of diabetic ED rats and treatment with Myocardin,the ICP/MAP of experimental animals was detected to observe the therapeutic effect of Myocardin on erectile function of diabetic ED rats.The content of H2S in serum and penile tissue was detected by H2S specific probe(WSP-1)and methylene blue colorimetry,and the cavernous tissue labeled with smooth muscle contractile marker and hydrogen sulfide producing enzyme was observed by laser confocal method,in order to explore the effect of Myocardin on the production of hydrogen sulfide and the expression of hydrogen sulfide producing enzyme.In the second part,the corpus cavernosum smooth muscle cells(CCSMC)were cultured in vitro and then the high glucose culture model was established.The adenoviral vectors of Myocardin and shMyocardin were constructed and transfected into CCSMC,by WSP-1 and methylene blue colorimetry was used to detect the changes of hydrogen sulfide production in and out of CCSMC cells.The expression levels of CSE and CBS of CCSMC after Myocardin overexpression or knockdown were observed,and the correlation and localization characteristics of Myocardin and CSE were observed in order to explore the molecular mechanism of Myocardin promoting hydrogen sulfide production of CCSMC.In the third part,the experimental animals were divided into five groups:NC,DMED,DMED treated with Myocardin,DMED treated with Myocardin+PAG(CSE inhibitor)and DMED injected with H2S.After the erectile function of rats in each group was measured by ICP,the effects of Myocardin on oxidative stress,apoptosis and fibrosis of corpus cavernosum tissue of diabetic ED rats were investigated by immunofluorescence and WB.RESULTSThe first part shows that Myocardin can improve the erectile function of diabetic ED rats.The level of H2S decreased in diabetic animals,and Myocardin treatment could significantly increase the level of hydrogen sulfide.The expression of CSE in Myocardin group was significantly higher than that in diabetic group,and hydrogen sulfide producing enzymes CSE and CBS were mainly located in corpus cavernosum smooth muscle.The second part showed that the hydrogen sulfide production of CSE and CBS,with less expression of CCSMC in high glucose culture was significantly decreased.The expression of CCSMC with enhanced Myocardin expression was significantly co-located with more CSE,Myocardin and CSE in CCSMC.The third part shows that the erectile function of diabetic ED rats is obviously damaged,which is closely related to the obvious oxidative stress,apoptosis and fibrosis in the corpus cavernosum of the penis.Myocardin can improve oxidative stress,apoptosis and fibrosis in corpus cavernosum of diabetic rats by increasing the expression of CSE and increasing the production of hydrogen sulfide.Myocardin combined with PAG can significantly inhibit the therapeutic effect of Myocardin,and the use of H2S can also achieve the therapeutic effect of Myocardin group.CONCLUTIONUnder the condition of diabetes or high glucose,the expression level of hydrogen sulfide-producing enzyme in CCSMC decreased and the production of H2S decreased.Myocardin can produce more H2S by increasing the CSE expression of CCSMC.H2S can significantly improve the oxidative stress,apoptosis and fibrosis of corpus cavernosum caused by diabetes,and finally improve the erectile function.