Department of Physiology, School of Medicine, University of Louisville, Louisville, KY 40202, USA.
Division of Endocrinology, Metabolism and Diabetes and Robley Rex VA Medical Center, University of Louisville School of Medicine, Louisville, KY 40202, USA.
Can J Physiol Pharmacol. 2024 Feb 1;102(2):105-115. doi: 10.1139/cjpp-2023-0186. Epub 2023 Nov 18.
Previous studies from our laboratory revealed that the gaseous molecule hydrogen sulfide (HS), a metabolic product of epigenetics, involves trans-sulfuration pathway for ensuring metabolism and clearance of homocysteine (Hcy) from body, thereby mitigating the skeletal muscle's pathological remodeling. Although the master circadian clock regulator that is known as brain and muscle aryl hydrocarbon receptor nuclear translocator like protein 1 (i.e., BMAL 1) is associated with -adenosylhomocysteine hydrolase (SAHH) and Hcy metabolism but how trans-sulfuration pathway is influenced by the circadian clock remains unexplored. We hypothesize that alterations in the functioning of circadian clock during sleep and wake cycle affect skeletal muscle's biology. To test this hypothesis, we measured serum matrix metalloproteinase (MMP) activities using gelatin gels for analyzing the MMP-2 and MMP-9. Further, employing casein gels, we also studied MMP-13 that is known to be influenced by the growth arrest and DNA damage-45 (GADD45) protein during sleep and wake cycle. The wild type and cystathionine β synthase-deficient (CBS) mice strains were treated with HS and subjected to measurement of trans-sulfuration factors from skeletal muscle tissues. The results suggested highly robust activation of MMPs in the wake mice versus sleep mice, which appears somewhat akin to the "1-carbon metabolic dysregulation", which takes place during remodeling of extracellular matrix during muscular dystrophy. Interestingly, the levels of trans-sulfuration factors such as CBS, cystathionine γ lyase (CSE), methyl tetrahydrofolate reductase (MTHFR), phosphatidylethanolamine -methyltransferase (PEMT), and Hcy-protein bound paraoxonase 1 (PON1) were attenuated in CBS mice. However, treatment with HS mitigated the attenuation of the trans-sulfuration pathway. In addition, levels of mitochondrial peroxisome proliferator-activated receptor-gamma coactivator 1-α (PGC 1-α) and mitofusin-2 (MFN-2) were significantly improved by HS intervention. Our findings suggest participation of the circadian clock in trans-sulfuration pathway that affects skeletal muscle remodeling and mitochondrial regeneration.
先前我们实验室的研究表明，气态分子硫化氢（HS）是一种表观遗传学的代谢产物，通过转硫途径来确保同型半胱氨酸（Hcy）的新陈代谢和清除，从而减轻骨骼肌的病理性重塑。尽管众所周知，生物钟的主要调节因子——脑和肌肉芳香烃受体核转位蛋白 1（即 BMAL1）与腺苷同型半胱氨酸水解酶（SAHH）和 Hcy 代谢有关，但转硫途径如何受生物钟影响仍未被探索。我们假设睡眠和清醒周期中生物钟功能的改变会影响骨骼肌的生物学特性。为了验证这一假设，我们使用明胶凝胶测量了血清基质金属蛋白酶（MMP）的活性，以分析 MMP-2 和 MMP-9。此外，我们还使用酪蛋白凝胶研究了 MMP-13，它在睡眠和清醒周期中受到生长停滞和 DNA 损伤 45（GADD45）蛋白的影响。我们用 HS 处理野生型和胱硫醚-β合酶缺陷（CBS）两种品系的小鼠，并测量骨骼肌组织中转硫途径的因素。结果表明，在清醒的小鼠中 MMP 高度活跃，而在睡眠的小鼠中 MMP 则相对不活跃，这与肌肉营养不良时细胞外基质重塑过程中发生的“一碳代谢失调”有些类似。有趣的是，CBS 小鼠中转硫途径的因素，如 CBS、胱硫醚γ裂解酶（CSE）、甲基四氢叶酸还原酶（MTHFR）、磷酸乙醇胺-N-甲基转移酶（PEMT）和 Hcy 蛋白结合对氧磷酶 1（PON1）的水平降低。然而，HS 的治疗减轻了转硫途径的衰减。此外，HS 干预显著改善了线粒体过氧化物酶体增殖物激活受体-γ共激活因子 1-α（PGC1-α）和线粒体融合蛋白 2（MFN-2）的水平。我们的研究结果表明，生物钟参与了影响骨骼肌重塑和线粒体再生的转硫途径。
