Mapping tissue immunity in the human urinary bladder across lifespan

膀胱是位于下腹部的一个中空的球形器官。它构成了尿路的一部分，负责将废物和多余的水从体内排出。含有排泄物和多余液体的尿液由肾脏产生，并被输送到膀胱，在排尿前储存在那里。这意味着膀胱距离外部环境相对较近，可能会受到来自身体表面的细菌(微生物)的攻击，包括来自肠道的微生物。我们知道，所有器官，包括膀胱，都含有一些常驻防御(免疫)细胞，帮助击退微生物。尽管如此，膀胱感染仍然很常见，女性一生中有1/2受到影响，男性每20人中就有1例受到影响。膀胱感染的易感性随着年龄的增长而增加，其他膀胱疾病也是如此，如炎症(可导致疼痛或大小便失禁等症状)和癌症。尽管免疫细胞在所有这些情况下都发挥了重要作用，但我们目前还不清楚膀胱防御是如何建立的，它是如何出错或随年龄变化的，以及这一点在男性和女性之间有何不同。我们的研究项目旨在解决这一知识差距。我们的总体目标是制作一张人类膀胱中所有免疫细胞的地图或图谱，包括男性和女性。我们将采取两种实验方法：第一种是提取一块人类膀胱，并将其捣碎，这样我们就可以分析单个细胞，包括免疫细胞。不同的细胞有不同的功能和识别标志，这是因为它们的遗传物质(称为基因)以及它们的遗传代码如何被翻译成细胞的工作部分的不同，称为蛋白质。每个细胞都含有数以千计的蛋白质，但这些蛋白质很难在单个细胞中大规模测量。然而，我们可以测量在基因和蛋白质之间起中介作用的分子--这被称为信使RNA或mRNA。在过去的10年里，技术已经进步到我们可以在一个细胞中测量数以千计的mRNA分子，这就是我们计划对捣碎的膀胱样本所做的事情。我们已经有了伦理许可，可以在整个生命周期内采集人类膀胱样本，包括胚胎(来自纽卡斯尔大学人类发育生物学资源)和成年人(来自剑桥的器官捐赠者，他们同意将组织用于研究)。我们的第二个实验方法是提取一块膀胱，并保持其完好无损，以便维持太空中细胞的关系。然后我们将把这块膀胱切片，这样它们就足够薄，可以在显微镜下观察到。我们将使用我们第一个实验中的信使核糖核酸信息来识别蛋白质标记物，这些蛋白质标记物可以使用荧光标记的探针在显微镜下可视化，我们还可以在太空中绘制信使核糖核酸分子图。这将使我们能够调查细胞相互之间的位置，并确定细胞的位置是否在男性和女性之间以及成年和发育中的膀胱中有所不同。制作一张完整的膀胱细胞寿命图将提供一个关键的参考图谱，有助于未来的研究人员了解在不同的膀胱疾病中哪些细胞变得异常，以及如何可能防止无益的年龄相关变化。

The urinary bladder is a hollow spherical organ situated in the lower abdomen. It forms part of the urinary tract, which is responsible for expelling waste and surplus water from the body. Urine, containing waste and excess fluid, is produced by the kidneys, and transported to the bladder where it is stored prior to voiding. This means that the bladder is in relatively close proximity to the external environment, and may be attacked by bugs (microbes) coming in from body surfaces, including microbes originating in the gut. We know that all organs, including the bladder, contain some resident defence (immune) cells that help to fight off microbes. Despite this, infection of the bladder is common, affecting 1 in 2 women in their lifetime and 1 in 20 men. Susceptibility to bladder infection increases with age, as do other bladder diseases, like inflammation (that can give symptoms such as pain or incontinence) and cancer. Despite the fact that immune cells play an important role in all of these conditions, we currently don't understand the details of how bladder defence is set-up, how this goes wrong or changes with age, and how this differs between men and women. Our research project aims to address this knowledge gap. Our overall aim is to produce a map or atlas of all the immune cells in the human bladder across lifespan, in men and women.We will take two experimental approaches: The first is to take a piece of human bladder, and to mash it up so that we can analyse individual cells, including immune cells. Different cells have different functions and identification marks because of differences in their genetic material (called genes), and differences in how their genetic code is translated into the working parts of cells, called proteins. Every cell contains thousands of proteins, but these are hard to measure at scale in a single cell. However, we can measure the molecule that acts as an intermediate between genes and proteins - this is called messenger RNA or mRNA. In the past 10 years, technology has advanced such that we can measure thousands of mRNA molecules in a single cell, this is what we plan to do with the mashed bladder samples. We already have ethical permissions in place to take human bladder samples across lifespan, including from embryos (from the Human Development Biology Resource at Newcastle University), and adults (from organ donors in Cambridge that have consented for their tissues to be used for research).Our second experimental approach is to take a piece of bladder and keep it intact so that the relationship of the cells in space is maintained. We will then make slices of the piece of bladder so that they are thin enough to be visualised under a microscope. We will use the mRNA information from our first experiment to identify protein markers that can be visualised by the microscope using probes that are fluorescently labelled and we can also map mRNA molecules in space. This will allow us to investigate the position of cells relative to each other and to determine whether the position of cells differs between men and women, and in the adult and developing bladder.Making a complete map of cells in the bladder across lifespan will provide a critical reference atlas that will help researchers in the future to understand which cells become abnormal in different bladder diseases and how it might be possible to prevent unhelpful age-related changes.