近日,來自美國馬歇爾大學的研究人員發現了阻斷細胞鈉鉀泵增強活性氧簇(ROS)作用效應的新機製,這些氧化物會導致肥胖和代謝綜合征的發生。相關研究結果發表在國際學術期刊science advances上。
領導該項研究的Joseph I. Shapiro這樣說道:"這項工作基於兩個重要部分,我們使用了由Dr. Zijian Xie開發的一種新多肽--pNaKtide。Dr. Zijian Xie告訴我們鈉離子泵除了能夠作為離子轉運蛋白發揮很好的作用,它還具有調節信號轉導以及放大氧化物效應的作用。我們還應用了Dr. Nader Abraham的一項工作,他們證明了在肥胖發生過程中脂肪細胞受到的氧化物應激起到關鍵作用。"
文章第一作者Komal Sodhi指出,他們在研究中檢測了pNaKtide對Na/K-ATPase信號級聯反應的阻斷作用,這種信號級聯反應能夠改變體外培養脂肪細胞的表型。
研究人員發現阻斷鈉鉀泵的作用能夠抑製高脂飲食誘導的小鼠肥胖及代謝綜合征,他們認為如果這一結果能夠在人類身上得到證實,那麼Na/K-ATPase或可最終成為臨床治療肥胖和代謝綜合征的一個靶向治療目標。
Shapiro說道,在確定這一信號途徑對人類有何影響之前仍然有很多工作要做,但他們仍然相信他們已經找到了治療肥胖和代謝綜合征的可行方法。
"我們至少已經發現了氧化物應激導致肥胖發生的一個新機製,同時我們的工作也為治療由氧化應激導致的多種疾病找到了一個新的靶向目標。"
DOI: 10.1126/sciadv.1500781
pNaKtide inhibits Na/K-ATPase reactive oxygen species amplification and attenuates adipogenesis
Komal Sodhi1, Kyle Maxwell1, Yanling Yan1, Jiang Liu1, Muhammad A. Chaudhry1, Morghan Getty1, Zijian Xie1, Nader G. Abraham1,2 and Joseph I. Shapiro
Obesity has become a worldwide epidemic and is a major risk factor for metabolic syndrome. Oxidative stress is known to play a role in the generation and maintenance of an obesity phenotype in both isolated adipocytes and intact animals. Because we had identified that the Na/K-ATPase can amplify oxidant signaling, we speculated that a peptide designed to inhibit this pathway, pNaKtide, might ameliorate an obesity phenotype. To test this hypothesis, we first performed studies in isolated murine preadipocytes (3T3L1 cells) and found that pNaKtide attenuated oxidant stress and lipid accumulation in a dose-dependent manner. Complementary experiments in C57Bl6 mice fed a high-fat diet corroborated our in vitro observations. Administration of pNaKtide in these mice reduced body weight gain, restored systemic redox and inflammatory milieu, and, crucially, improved insulin sensitivity. Thus, we propose that inhibition of Na/K-ATPase amplification of oxidative stress may ultimately be a novel way to combat obesity, insulin resistance, and metabolic syndrome.