Liao Yulin, Takashima Seiji, Maeda Norikazu, Ouchi Noriyuki, Komamura Kazuo, Shimomura Iichiro, Hori Masatsugu, Matsuzawa Yuji, Funahashi Tohru, Kitakaze Masafumi
Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Cardiovasc Res. 2005 Sep 1;67(4):705-13. doi: 10.1016/j.cardiores.2005.04.018.
Insulin resistance (IR) was reported to be associated with chronic heart failure (CHF). Adiponectin, an insulin-sensitizing hormone with anti-inflammatory activity, improves energy metabolism via AMP-activated protein kinase (AMPK). AMPK deficiency is associated with depressed cardiac function under stress conditions. However, it is not clear whether adiponectin plays an important role in CHF. We hypothesize that deficiency of adiponectin might result in deterioration of heart failure.
Using adiponectin null mice and their littermates, we examined the effects of adiponectin on LV pressure overload-induced cardiac hypertrophy and failure, and investigated the mechanisms involved.
Three weeks after transverse aortic constriction (TAC), cardiac hypertrophy (evaluated from the heart-to-body weight ratio: 7.62+/-0.27 in wild-type (WT) mice, 9.97+/-1.13 in knockout (KO) mice, P<0.05) and pulmonary congestion (lung-to-body weight ratio: 9.05+/-1.49 in WT mice, 14.95+/-2.36 in KO mice, P<0.05) were significantly greater in adiponectin KO mice than WT mice. LV dimensions were also increased in KO mice. Compared with WT TAC mice, expression of AMPKalpha protein was lower, while IR was higher in KO TAC mice.
These findings indicate that adiponectin deficiency leads to progressive cardiac remodeling in pressure overloaded condition mediated via lowing AMPK signaling and impaired glucose metabolism.
据报道,胰岛素抵抗(IR)与慢性心力衰竭(CHF)相关。脂联素是一种具有抗炎活性的胰岛素增敏激素,通过腺苷酸活化蛋白激酶(AMPK)改善能量代谢。AMPK缺乏与应激条件下的心功能降低有关。然而,脂联素在CHF中是否起重要作用尚不清楚。我们假设脂联素缺乏可能导致心力衰竭恶化。
使用脂联素基因敲除小鼠及其同窝小鼠,我们研究了脂联素对左心室压力超负荷诱导的心脏肥大和心力衰竭的影响,并探讨了其中涉及的机制。
在横向主动脉缩窄(TAC)三周后,脂联素基因敲除小鼠的心脏肥大(根据心重与体重比评估:野生型(WT)小鼠为7.62±0.27,基因敲除(KO)小鼠为9.97±1.13,P<0.05)和肺充血(肺重与体重比:WT小鼠为9.05±1.49,KO小鼠为14.95±2.36,P<0.05)明显比WT小鼠更严重。KO小鼠的左心室尺寸也增加。与WT TAC小鼠相比,KO TAC小鼠中AMPKα蛋白的表达较低,而IR较高。
这些发现表明,脂联素缺乏导致压力超负荷条件下通过降低AMPK信号传导和损害葡萄糖代谢介导的进行性心脏重塑。