Author: Nick

  • 科学家在小鼠身上逆转视神经衰老,恢复视力

    该研究通过表观遗传重编程(epigenetic reprogramming)技术,成功恢复动物年轻的表观遗传信息,该实验的成功也证明了安全地逆转视网膜等复杂组织的衰老并使其生理功能恢复年轻的可能性。 该小组使用腺相关病毒(AAV)作为载体,将三个恢复细胞年轻的基因-Oct4,Sox2和Klf4传递到小鼠的视网膜中。 这三个基因,连同第四个基因(未在这项研究中使用)一起被称为山中因子。 该治疗对眼睛有多种有益作用。首先,它促进了视神经损伤小鼠视神经损伤后的神经再生;其次,它逆转了具有模仿人类青光眼状况的动物的视力丧失;第三,它可以逆转没有青光眼的衰老动物的视力丧失。 在将这项技术推广到人类实验之前,研究仍需在未来的实验中验证其可重复性(包括不同的动物模型),尽管如此,这项研究从概念上证明了,通过安全可控的体内重编程,衰老或受损的细胞能够恢复其年轻的表观遗传功能,为未来设计一系列与衰老相关的疾病疗法提供了富有前景的途径。

  • 研究发现导致脑疾病中蛋白聚集的新机制

    Tau蛋白聚集成纤维状结构是阿尔茨海默氏病以及其他几种神经退行性疾病的主要致病环节之一。该研究基于最近关于tau蛋白容易”液-液”相分离(LLPS)的报告,展开了对疾病相关突变,LLPS和tau纤维化之间的关系的探索。 这项研究的数据表明,与之前不同,假重复区域内的致病突变不会影响tau441形成液滴的倾向,然而,LLPS确实极大地促进了纤维状聚集体的形成,并且这种效应对于具有疾病相关突变的tau441变体尤其显着。更重要的是,这项研究揭示了以前未知的机制,LLPS可以通过该机制调节包含不同聚集倾向的tau亚型的混合物的纤维化速率。这种调节是由于蛋白质在LLPS条件下的独特特性所致,在该条件下,浓缩相中所有tau变体的总浓度恒定。因此,缓慢聚集的tau亚型的比例增加逐渐降低了具有高聚集倾向的亚型的浓度,从而降低了其纤维化速率。 这种调节机制可能与tau蛋白病的表型变异性直接相关,因为在不同疾病中大脑中快速聚集和缓慢聚集的tau亚型的比率存在很大差异。

  • 一种试验药物可在几天内逆转与年龄有关的精神衰退

    新的研究发现,一种试验药物可以逆转与年龄相关的小鼠记忆功能下降。该药物为ISR抑制剂类药物,目前已在实验室中显示出可逆转唐氏综合症患者的认知功能障碍,在创伤性脑损伤后恢复记忆功能以及增强健康动物的认知能力。 研究人员训练年长的小鼠通过找到一个隐秘的平台,然后从水迷宫逃脱,这项任务通常对年长的小鼠来说很难做到,但在训练过程中每天接受小剂量ISR抑制剂的小鼠以及年轻的小鼠,它们都能完成这项任务,且完成情况都比未接受ISR抑制剂的年长小鼠好。然后,研究人员测试了这种认知恢复现象可以持续多久,以及是否可以推广到其他认知技能上。在最初的ISR抑制剂治疗几周后,他们训练同样的小鼠走出迷宫,迷宫的出口每天都在变化,这是针对测试年长小鼠的心理灵活性。结果显示,三周前接受ISR抑制剂短暂治疗的小鼠仍然表现出年轻时的水平,而未接受治疗的小鼠则继续被困。 为了了解ISR抑制剂如何改善脑功能,研究人员在给动物单剂量ISR抑制剂的一天后,研究了海马细胞的活动和解剖结构,海马是在学习和记忆中起关键作用的大脑区域。他们发现神经元衰老的共同特征几乎在一夜之间消失了:神经元的电活动变得更加明快,并对刺激做出了反应,细胞与周围的细胞表现出更强的连通性,同时还表现出与彼此之间形成稳定连接的能力。

  • 2020 TCCI Holiday Newsletter

    2020 TCCI Holiday Newsletter

    It is with news of Covid vaccines and the promise of an eventual return to normalcy that we wish you a warm and happy holiday season. While 2020 has presented us

  • One step closer to a brain prosthesis for the blind: Human Brain Project-supported innovation

    Human Brain Project research has helped lay the foundation for a brain implant that could one day give blind people their sight back. Recent discoveries at the Netherlands Institute for Neuroscience (NIN) show that in monkeys, newly developed high-resolution implants in the visual cortex make it possible to recognize artificially induced images. The findings were […]

  • Two Caltech Faculty Receive NIH BRAIN Grants

    Two Caltech Faculty Receive NIH BRAIN Grants

    Two TCCI®-affiliated researchers at Caltech have received funding for neuroscience projects from the National Institutes of Health’s Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative.   Joe Parker, Assistant Professor of Biology and Biological Engineering, is the lead investigator on a project that aims to study the brain circuits that control behavioral interactions between animals. […]

  • What social distancing does to a brain

    Have you recently wondered how social-distancing and self-isolation may be affecting your brain? An international research team led by Erin Schuman from the Max Planck Institute for Brain Research discovered a brain molecule that functions as a “thermometer” for the presence of others in an animal’s environment. Zebrafish “feel” the presence of others via mechanosensation […]

  • Major depressive disorder may be defined by a distinct gut microbiome

    Scientists have identified 3 bacteriophages, 47 bacterial species, and 50 fecal metabolites that were significantly more or less abundant in people with major depressive disorder (MDD) compared with healthy controls, according to a study in 311 individuals. The findings provide evidence that MDD may be characterized by gut microbiome disturbances. Jian Yang and colleagues also […]

  • Common neural circuit and potential target for anxiety and obsessive-compulsive disorder

    In a study recently published in PNAS, Dr. Jing-Ning Zhu’s group in Nanjing University reports that a glutamatergic neuronal circuitry from the prelimbic prefrontal cortex (PrL) to the nucleus accumbens (NAc) core is responsible for co-occurrence of anxiety- and obsessive-compulsive-like behaviors. Notably, activation of the histamine presynaptic H3 heteroreceptor localized in the PrL-NAc glutamatergic terminals […]

  • Scientists reverse age-related vision loss, eye damage from glaucoma in mice

    Proof-of-concept study represents first successful attempt to reverse the aging clock in animals through epigenetic reprogramming. Scientists turned on embryonic genes to reprogram cells of mouse retinas. Approach reversed glaucoma-induced eye damage in animals. Approach also restored age-related vision loss in elderly mice. Work spells promise for using same approach in other tissues, organs beyond […]