Department of Physiology and Pathophysiology, Center for Noncoding RNA Medicine, MOE Key Lab of Cardiovascular Sciences, School of Basic Medical Science, State Key Laboratory of Natural and Biomimetic Drugs, the School of Pharmaceutical Sciences, Peking University, Beijing, P.R. China.
Hypertension Center, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Beijing, P.R. China.
Br J Pharmacol. 2019 Sep;176(17):3180-3192. doi: 10.1111/bph.14719. Epub 2019 Jul 14.
Hydrogen sulfide donors can block the cardiovascular injury of hyperhomocysteinemia. H S also lowers serum homocysteine in rats with mild hyperhomocysteinemia, but the pharmacological mechanism is unknown. The present study investigated the mechanism(s) involved.
ApoE-knockout mice were fed a Paigen diet and L-methionine in drinking water for 16 weeks to create a mouse model of atherosclerosis with hyperhomocysteinemia. H S donors (NaHS and GYY4137) were administered by intraperitoneal injection. We also assayed the H S produced (by methylene blue assay and mito-HS [H S fluorescence probe]), cystathionine γ lyase (CSE) mRNA and protein expression, and CSE sulfhydration and nitrosylation and its activity.
H S donor treatment significantly lowered atherosclerotic plaque area, macrophage infiltration, and serum homocysteine level in the mouse model of atherosclerosis with co-existing hyperhomocysteinemia. mRNA and protein levels of CSE, a key enzyme catalyzing homocysteine trans-sulfuration, were down-regulated with hyperhomocysteinemia, and CSE catalytic activity was inhibited. All these effects were reversed with H S donor treatment. Hyperhomocysteinemia induced CSE nitrosylation, whereas H S sulfhydrated CSE at the same cysteine residues. Nitrosylated CSE decreased and sulfhydrated CSE increased its catalytic and binding activities towards L-homocysteine. Mutation of C252, C255, C307, and C310 residues in CSE abolished CSE nitrosylation or sulfhydration and prevented its binding to L-homocysteine.
Sulfhydration or nitrosylation of CSE represents a yin/yang regulation of catalysis or binding to L-homocysteine. H S donor treatment enhanced CSE sulfhydration, thus lowering serum L-homocysteine, which contributed in part to the anti-atherosclerosis effects in ApoE-knockout mice with hyperhomocysteinemia.
硫化氢供体可以阻断高同型半胱氨酸血症的心血管损伤。H2S 还可以降低轻度高同型半胱氨酸血症大鼠的血清同型半胱氨酸水平，但药理机制尚不清楚。本研究探讨了相关机制。
apoE 基因敲除小鼠喂食派根饮食和 L-蛋氨酸饮用水 16 周，建立高同型半胱氨酸血症动脉粥样硬化小鼠模型。通过腹腔注射给予 H2S 供体（NaHS 和 GYY4137）。我们还检测了 H2S 的产生（亚甲基蓝法和线粒体-H2S [H2S 荧光探针]）、胱硫醚γ裂解酶（CSE）mRNA 和蛋白表达、CSE 巯基化和亚硝基化及其活性。
H2S 供体治疗显著降低了同时存在高同型半胱氨酸血症的动脉粥样硬化小鼠模型中的动脉粥样硬化斑块面积、巨噬细胞浸润和血清同型半胱氨酸水平。同型半胱氨酸转硫途径关键酶 CSE 的 mRNA 和蛋白水平随高同型半胱氨酸血症而下调，CSE 催化活性受到抑制。所有这些作用均随 H2S 供体治疗而逆转。高同型半胱氨酸血症诱导 CSE 亚硝基化，而 H2S 则在相同半胱氨酸残基上使 CSE 巯基化。CSE 的亚硝基化减少，巯基化增加了其对 L-同型半胱氨酸的催化和结合活性。CSE 的 C252、C255、C307 和 C310 残基的突变消除了 CSE 的亚硝基化或巯基化，并阻止了其与 L-同型半胱氨酸的结合。
CSE 的巯基化或亚硝基化代表了对 L-同型半胱氨酸催化或结合的阴阳调节。H2S 供体治疗增强了 CSE 的巯基化，从而降低了血清 L-同型半胱氨酸水平，这部分有助于降低 apoE 基因敲除小鼠高同型半胱氨酸血症的动脉粥样硬化。
