Faculty of Chemistry and Environmental Science, Guangdong Ocean University, Zhanjiang, Guangdong, People's Republic of China.
Department of Hematology, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong, People's Republic of China.
Biomed Pharmacother. 2019 Sep;117:109204. doi: 10.1016/j.biopha.2019.109204. Epub 2019 Jul 9.
We wished to investigate the role of a tilapia skin collagen polypeptide (TSCP; molecular weight <3 kDa) in alleviating liver and kidney injuries in aging mice induced by d-galactose (d-gal) and its underlying mechanism of action. First, we characterized TSCP. TSCP was passed through a 3-kDa ultrafiltration membrane, desalted in water by a solid-phase extraction column, purified further by reverse phase-high performance liquid chromatography, and analyzed by electrospray ionization mass spectrometry and tandem mass spectrometry. TSCP contained 17 types of amino acids (AAs) and 41 peptide chains of length 7 AAs to 22 AAs. The content of free AAs and total AAs of TSCP was 13.5% and 93.79%, respectively. Next, we undertook animal experiments. Mice were injected once-daily with D-gal (300 mg/kg body weight, s.c.) for 8 weeks, and TSCP was administered simultaneously once-daily by intragastric gavage. TSCP could visibly improve the decreased body weight, depressed appetite, and mental deterioration of mice triggered by d-gal. TSCP could also alleviate d-gal-induced damage to the liver and kidneys according to histopathology (especially high-dose TSCP). Consistent with these macroscopic and pathologic changes, TSCP could also prevent d-gal-induced increases in serum levels of alanine aminotransferase, aspartate transaminase, alkaline phosphatase, lipid peroxidation, creatinine and uric acid, as well as decreases in serum levels of immunoglobulin (Ig)G and IgM. Moreover, TSCP improved the activities of superoxide dismutase, catalase, and glutathione peroxidase, but also inhibited the increases in the levels of malondialdehyde and inducible nitric oxide synthase expression in the liver and kidneys of d-gal-treated mice. These results suggest that TSCP can alleviate the injuries to the liver and kidneys in aging mice induced by d-gal, and that its mechanism of action might be, at least partially, associated with attenuation of oxidative stress and enhancement of immune function.
我们希望研究罗非鱼皮胶原蛋白多肽（TSCP；分子量<3 kDa）在缓解 D-半乳糖（D-gal）诱导的衰老小鼠肝肾功能损伤中的作用及其作用机制。首先，我们对 TSCP 进行了表征。TSCP 通过 3 kDa 超滤膜，在固相萃取柱中用水脱盐，进一步通过反相高效液相色谱纯化，用电喷雾电离质谱和串联质谱分析。TSCP 含有 17 种氨基酸（AAs）和 41 条长度为 7 到 22 个氨基酸的肽链。TSCP 中游离氨基酸和总氨基酸的含量分别为 13.5%和 93.79%。接下来，我们进行了动物实验。小鼠每天一次皮下注射 D-gal（300 mg/kg 体重），连续 8 周，同时每天一次灌胃给予 TSCP。TSCP 可明显改善 D-gal 引起的小鼠体重下降、食欲减退和精神恶化。TSCP 还可以根据组织病理学减轻 D-gal 引起的肝肾功能损害（尤其是高剂量 TSCP）。与这些宏观和病理变化一致，TSCP 还可以防止 D-gal 引起的血清丙氨酸氨基转移酶、天冬氨酸转氨酶、碱性磷酸酶、脂质过氧化、肌酐和尿酸水平升高，以及免疫球蛋白（Ig）G 和 IgM 水平降低。此外，TSCP 提高了超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶的活性，同时抑制了 D-gal 处理小鼠肝肾功能中丙二醛和诱导型一氧化氮合酶表达的增加。这些结果表明，TSCP 可以缓解 D-gal 诱导的衰老小鼠的肝肾功能损伤，其作用机制可能至少部分与减轻氧化应激和增强免疫功能有关。
