咖啡让人着迷,原因有很多……
2018/06/26
“咖啡”一词源于希腊语“Kaweh”,意指“力量与激情”。除了提神醒脑之外,不少研究还揭示咖啡在预防和治疗多种疾病上也发挥着潜在作用,包括对抗痴呆、降低癌症风险等。近期,科学家们找到了“喝咖啡有利心脏健康”的机制,并揭示其在治疗糖尿病上的潜能。


The caffeine in four cups of coffee triggers multiple protective effects. Credit: Nathan Dumlao, Pixabay

咖啡中的咖啡因被证实可以降低许多疾病的发生风险,包括II型糖尿病、心脏病和中风。但是,背后的保护机制尚不清楚。6月21日,《PLOS Biology》期刊最新发表的一项研究表明,咖啡因可以促进调控蛋白进入线粒体,并增强后者的功能,保护心肌细胞免受伤害。

这一研究由杜塞尔多夫大学的Judith Haendeler 、Joachim Altschmied和团队完成。他们发现,达到这一保护作用的浓度相当于饮用4杯咖啡。


https://doi.org/10.1371/journal.pbio.2004408

保护心脏

Judith Haendeler团队先前已经证明,在生理相关浓度下(即四杯或者更多杯咖啡达到的水平),咖啡因可以提高内皮细胞(位于血管内壁)的能力。

在最新的研究中,他们发现,蛋白质p27(一种细胞周期抑制因子)存在于心肌细胞的线粒体中,负责促进内皮细胞的迁移,保护心肌细胞免于死亡,并将成纤维细胞转化为含有收缩纤维的细胞(这一环节对于心肌梗死后心肌的修复过程至关重要)。

研究显示,咖啡因(4杯咖啡达到的浓度)会促进p27进入线粒体,从而引发一系列有益的反应。而且,小鼠试验揭示,无论是糖尿病前期的肥胖小鼠还是年老小鼠,咖啡因都会对其心脏起保护作用。

“我们的研究表明,咖啡因有一种新的作用方式。” Haendeler解释道,“其中之一是通过p27蛋白促进心肌的保护和修复。这一通路预示着保护心肌不受损伤的新策略,增强线粒体p27不仅可以作为心血管疾病一种潜在的治疗策略,而且可以改善健康状况。”

治疗糖尿病


https://doi.org/10.1038/s41467-018-04744-1

糖尿病患者血糖水平高于正常水平,这可能会导致一系列健康问题。目前的治疗策略包括提高细胞对于胰岛素的敏感度以及注射胰岛素。现在,科学家们想出了新招,可以在最需要的时候促使更多的胰岛素进入人体。

来自于苏黎世联邦理工学院、瑞士巴塞尔大学和法国理工大学的科学家们证实,在咖啡因的刺激下,被改装成分泌胰岛素的人胚肾细胞能够降低小鼠的血糖水平。这一研究发表在《Nature Communications》期刊。

与注射补充胰岛素不同,研究团队设计了可以表达胰岛素的胚胎肾细胞,但是这一功能只有在咖啡因的刺激下才能实现。

之所以选择咖啡因,是因为它被广泛研究,且多数人都会喝含有咖啡因的饮料。研究人员强调,咖啡因是一种很少出现在其他食物中的化合物,因此摄入量很容易被控制。

这些肾脏细胞被一种保护它们免受免疫系统排斥的物质包裹,随后注入一种植入糖尿病小鼠腹部的装置中。研究人员会在小鼠进食后让它们摄入咖啡因,通过改变咖啡因含量,让小鼠保持相对稳定的葡萄糖水平。

研究人员表示,这一方案进入临床试验还有很长的路要走,未来该方法可能也适用于其他疾病。

责编:风铃

参考资料:

Caffeine from four cups of coffee protects the heart with the help of mitochondria

Kidney cells engineered to produce insulin when caffeine is present in the body

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