Professor Jing Xu and her students study extremely tiny motor proteins, but their work could make a huge contribution to the growing body of knowledge about Alzheimer’s and other diseases that progressively destroy brain tissue.

徐静教授和她的学生们研究极其微小的运动蛋白，但是他们的工作可以为阿尔茨海默病和其他进行性破坏脑组织的疾病的研究做出巨大贡献。

Alzheimer's disease is, so far, untreatable and incurable and is the sixth most common cause of death in adults in the United States. An estimated 5.7 million people have the disease. Dysfunction of a protein called tau is the hallmark of Alzheimer’s disease. Xu’s lab is working to understand how cellular cargos navigate around abnormally high levels of tau proteins on microtubules to keep the cells healthy, rather than degenerating.

到目前为止，阿尔茨海默病是无法治愈的，是美国成年人的第六大常见死因之一。据统计，约有570万人患有该种疾病。一种叫做tau的蛋白质功能障碍是患老年痴呆症的标志。徐的实验室正在研究细胞载体如何绕过微管上异常高水平的tau蛋白来保持细胞健康，而不是退化。

Such understanding could pave the way for future therapeutics, she said.

她说，这样的理解可以为未来的治疗方法铺平道路。

She explained the cellular system she’s looking at with a highway analogy:

她用一个高速公路的比喻来解释她正在观察的细胞网络:

Imagine the microtubules inside cells are roads. The “cars” on the roadway are lipid membranes containing cellular cargo, and traveling to their destinations using “wheels,” or motor proteins. The cars travel along the roads unhindered unless they come upon a roadblock — tau proteins. If that happens, the cars and wheels need a strategy for navigating the roadblock to ensure cell survival and health. Tau is abundant in human neurons and isn’t always a hindrance to cargo delivery — only when there is too much of it, as when there is a neurodegenerative disease.

想象细胞内的微管是道路。公路上的“汽车”是脂质膜，里面装着蜂窝状的货物，它们通过“车轮”或马达蛋白到达目的地。汽车在路上畅通无阻，除非遇到路障——tau蛋白。如果发生这种情况，汽车和车轮需要一种策略来通过路障，以确保细胞存活和健康。Tau蛋白在人类神经元中含量丰富，并不总是货物运输的障碍——只有当Tau蛋白过多时，才会如此，如神经退行性疾病。

With a prestigious R15 Award from the National Institutes of Health (NIH), Xu is studying how changes in the lipid membranes that link the motor protein “wheels” together can help make sure the car navigates the unwanted roadblocks. Understanding these mechanisms could help combat the roadblocking effect of tau on critical cargo delivery.

徐获得了美国国立卫生研究院（the National Institutes of Health，NIH）著名的R15奖，她正在研究连接运动蛋白“车轮”的脂质膜的变化如何有效确保汽车通过不需要的路障。了解这些机制有助于克服tau蛋白在关键货物运输中的拦路效应。

Xu is an experimentalist working at the intersection of physics and biology. She is with the Department of Physics in the School of Natural Sciences, and is a member of the NSF CREST Center for Cellular and Biomolecular Machines.

徐是一位从事物理学和生物学交叉研究的实验主义者。她在自然科学学院物理系工作，是美国国家科学基金会细胞和生物分子机器中心（the NSF CREST Center for Cellular and Biomolecular Machines）的成员。

Students in her lab use optical trapping — a nano “tractor beam” that won the Nobel Prize in physics in 1997 and 2018 — to tackle research questions. They shine a tightly focused laser beam onto particles to manipulate the motor proteins at nanometer precision.

在她的实验室里，学生们使用光学捕获——一种在1997年和2018年获得诺贝尔物理学奖的纳米“牵引光束”技术——来解决研究问题。他们将一束高度聚焦的激光束照射在粒子上，以纳米精度操纵运动蛋白。

“We think the lipid membrane that encloses the cargo is really important for the proper delivery of the cargo,” Xu said. “We can change the car’s delivery by changing its shell.”

“我们认为包裹货物的脂质膜对货物的正常运输非常重要，”徐说。“我们可以通过更换外壳来改变汽车的交付方式。”

Recent data from the Xu lab shows cholesterol, a type of fat found in the membranes, to be a factor.

来自徐实验室的最新数据表明，胆固醇，一种细胞膜中的脂肪，是因素之一。

“When we add cholesterol to the membrane, the roadblocking effect becomes a lot stronger,” Xu said. “Now we want to understand how cholesterol is changing the membrane ... Where is the transition? Is there a critical level of cholesterol that we should stay under?”

“当我们在细胞膜上添加胆固醇时，拦路效应会变得更强，”徐说。“现在我们想知道胆固醇是如何改变细胞膜的……在哪里改变?我们的胆固醇是否应该保持在临界水平以下?”

Xu is excited to engage undergraduate students in these research explorations.

徐很高兴能让本科生参与这些探索研究。

“I started my research career as a sophomore in college. It was a really great experience,” she said. Students interested in taking part in this research can contact her by email.

“我在大学二年级时就开始了我的研究生涯。这是一次非常棒的经历，”她说。有兴趣参与这项研究的学生可以通过电子邮件联系她。

“This is a great time for research in molecular motor biophysics,” she said. “We have a lot of really amazing tools from the physical sciences that we can use to answer important open questions in biology.”

“现在是研究分子运动生物物理学的大好时机，”她说。“我们有很多来自物理科学的神奇工具，可以用来回答生物学中重要的开放性问题。”