Application Of Nitric Oxide In The Prevention And Treatment Of Cardiovascular Diseases And Tumors

Cardiovascular disease and tumor are the two major chronic diseases with the highest mortality rate,which seriously threaten human health.Nitric oxide(NO),as a biologically active signal transduction molecule,plays an important role in the prevention and treatment of chronic diseases.Compared with other chemical agents,the endogenous NO and its characteristics of transforming into harmless ions after 6 seconds of action determine that it can not only exert its efficacy,but also minimize its toxic and side effects.Therefore,NO is considered to be an ideal drug.Strategies based on the regulation of NO generation have become a research hot-spot in cardiovascular and tumor fields in recent years.Calcific aortic valve disease(CAVD)has become the third major cardiovascular disease after hypertension and ischemic heart disease,which seriously threatens human health.More and more attention has been paid to the role of NO in CAVD.Studies have shown that NO plays an important role in inhibiting cardiovascular calcification,but its underlying mechanism is still unclear.In recent years,the role of NO in tumor therapy has been widely explored.The strategy of improving tumor microenvironment by regulating NO production in tumor site can significantly enhance the sensitivity of other traditional therapies.Based on the above theoretical background,this study will focus on the regulation of NO production and explore its application in the treatment of CAVD and tumor.Explore the effect of NO on BVICs calcification in vitro.Bovine aortic valve interstitial cells(BVICs)were isolated from bovine aortic valve by two-step enzymatic hydrolysis.The purity and phenotype of BVICs were identified by ?-SMA and Vimentin immunofluorescence staining.BVICs were cultured in calcification induced medium(also known as osteogenic induction medium)to construct the in vitro calcification model,and the related characterization was used to investigate whether the in vitro calcification model based on BVICs was successfully constructed.To investigate the effects of NO on osteogenic differentiation,inflammation and calcium deposition in BVICs,exogenous supplement of NO donor DETA-NONOate and NOS inhibitor L-NAME was conducted.The results showed that BVICs were successfully isolated and a good in vitro calcification model was established.The intervention with DETA-NONOate or L-NAME on BVICs induced showed that NO could inhibit valve calcification by down regulating the expression of osteogenic differentiation related genes and proteins(Runx2,ALP,OCN and OPN),inhibiting macrophage migration and the production of inflammatory cytokines IL-1 ?,IL-6 and TNF-?,as well as directly inhibiting calcium deposition in BVICs,which provided a new idea for the application of NO in the treatment of CAVD.Investigate the effect of NO on aortic valve calcification.Male ApoE-/-mice aged 6-8 weeks were used to establish aortic valve calcification model,and L-Arg or L-NAME were injected intraperitoneally to explore the effect of NO on aortic valve calcification in mice.The results showed that the aortic valve calcification model could be successfully established by feeding ApoE-/-mice with high fat diet(HFD);L-Arg could not only reduce blood lipid level,but also inhibit calcium deposition in aortic valve,as well as down regulate the expression of calcification related genes in aortic valve;and L-Arg could also reduce the contents of IL-1?,IL-6 and TNF-? in serum and infiltration of inflammatory macrophages in aortic valve tissue.This part of the study suggests that L-Arg is expected to become a new drug for the treatment of CAVD,which has the multiple effects of anti-inflammatory,regulating lipid metabolism and inhibiting calcium deposition.Explore the effect of NO on the anti-calcification property of glutaraldehyde-crosslinked bovine pericardium(GA-BP).The effects of NO on the anti-calcification of GA-BP were evaluated by intraperitoneal injection of L-Arg and L-NAME.The results showed that NO could improve the anti-calcification property of GA-BP and promote the infiltration of M2 macrophages.Investigate the effect of NO combined with PDT on tumor therapy in vitro and in vivo.The NO donor L-Arg and photosensitizer ICG were co-encapsulated in the dual delivery system of PLGA nanoparticles and PCL-PEG-PCL thermosensitive hydrogels.The synergistic effect of NO combined PDT in tumor therapy was explored by regulating the generation of NO in tumor sites.The results show that NO can promote the activation of matrix metalloproteinase(MMPs)in tumor site,and then degrade the over expressed extracellular matrix(ECM)collagen I,and then synergistically enhance the effect of PDT in tumor treatment,thus providing a new possibility for combined treatment of cancer.In conclusion,NO could not only inhibit the occurrence and development of CAVD by regulating inflammatory reaction,osteogenic differentiation and calcium deposition,but also synergistically enhance the effect of PDT by killing tumor cells and destroying collagen matrix at tumor site.Therefore,NO has great potential in the control of CAVD and in tumor combination therapy.