Gut Dysbiosis and Cerebral Small Vessel Disease

肠道菌群失调和脑小血管疾病

基本信息

批准号：
10200157
负责人：
ROBERT M BRYAN
金额：
$ 40.03万
依托单位：
BAYLOR COLLEGE OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2022-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10200157
关键词：
Affect Animal Diseases Animal Model Antibiotics Antigens Attention Attenuated Bacteria Bacterial DNA Bacterial RNA Bacterial Translocation Blood Blood - brain barrier anatomy Brain Brain Pathology Cardiovascular Diseases Cecum Cerebral small vessel disease Cerebrovascular Disorders Cerebrum Characteristics DNA Data Development Disease Distal Encephalitis Endotoxins Engineering Equilibrium Feces Fluorescent in Situ Hybridization Fostering Gastrointestinal tract structure Gram-Negative Bacteria Hypertension Impaired cognition Inbred WKY Rats Inflammation Label Lacunar Infarctions Lipopolysaccharides Location Measures Microaneurysm Microbe Modeling Movement Names National Institute of Neurological Disorders and Stroke Parents Pathologic Pathology Peptidoglycan Phenotype Probiotics Process Rattus Reporter Reverse Transcriptase Polymerase Chain Reaction Source Stroke Symptoms Taxonomy Testing Therapeutic Intervention arteriole brain health dysbiosis gastrointestinal epithelium gray matter gut bacteria gut dysbiosis gut microbiome gut microbiota microbiome novel nursing mothers prevent pup rRNA Genes targeted treatment white matter

项目摘要

Cerebral small vessel disease (CSVD), a recognized priority established by the NINDS, is a major cause of cognitive impairment. In this proposal, we present the novel idea that antigens derived from the gut microbiota constitute a fundamental source for the inflammation underlying CSVD. We propose that gut dysbiosis allows bacteria and bacterial components to translocate the gut epithelial barrier and ultimately gain access to the brain where they initiate and maintain inflammation necessary for the development of CSVD. The hypothesis is supported with strong preliminary data: (1) gut dysbiosis occurs in spontaneously hypertensive stroke-prone rats (SHRSP), a relevant model for CSVD, compared to its parent strain, WKY rats; (2) altering the gut microbiome in WKY rats to resemble that of SHRSP is accompanied by pathological changes occurring in SHRSP. Altering the gut microbiome in SHRSP rats to resemble that of WKY rats attenuates these pathological changes; (3) brains of SHRSP contain 52% more bacterial DNA than WKY rats; (4) gram-negative bacteria represent a substantially greater proportion of the overall bacterial DNA in brains of SHRSP compared to WKY rats; and (5) lipopolysaccharides (LPS), bacterial endotoxin derived from gram negative bacteria, are substantially increased in brains of SHRSP compared to WKY rats. In Specific Aim 1 we will determine if CSVD can be produced or prevented through manipulation of the gut microbiota. If gut dysbiosis is an underlying cause of CSVD then we should be able to induce CSVD in control WKY rats, the parent strain for the SHRSP, by inducing dysbiosis. Alternatively, we should be able to abolish or delay the onset of CSVD in SHRSP rats by preventing dysbiosis. In Specific Aim 2 we will identify gut and brain bacteria and bacterial components involved with the initiation of CSVD. (a) We will analyze the bacterial DNA composition of the gut and brain by sequencing the bacterial 16s rRNA gene from feces, cecal content, and brain. Using targeted qPCR, we will further identify bacteria to the species level. (b) We will determine if intact bacteria are resident in the brain using RT-PCR and fluorescence in situ hybridization of SHRSP and WKY rats. In Specific Aim 3 we propose to track the movement of bacteria and bacterial components, a process termed translocation, from the gut to the brain. First, we will determine if fluorescently labeled LPS and peptidoglycan track to the brain when gavaged into the gut of SHRSP and WKY rats. Second, we will employ bacteria that we have engineered with reporters to track bacteria from gut to brain and determine if gram- negative bacteria are capable of translocating from gut to brain more efficiently in hosts developing CSVD. If our hypothesis is valid, then the gastrointestinal tract (GI) can affect the health of the brain. Establishing the gut microbiome as a source for inflammation related to CSVD could dramatically refocus our attention on the GI tract as a potential cause for brain pathologies, as well as provide a target for therapeutic intervention.

脑小血管疾病 (CSVD) 是 NINDS 确定的公认优先事项，是导致认知障碍。在这项提案中，我们提出了新的想法，即源自肠道微生物群的抗原是 CSVD 炎症的基本来源。我们建议肠道菌群失调允许细菌和细菌成分移位肠道上皮屏障并最终获得进入大脑，在那里它们引发并维持发展所需的炎症 CSVD。该假说得到了强有力的初步数据的支持：（1）肠道菌群失调是自发发生的。高血压脑卒中大鼠 (SHRSP)（脑小血管病的相关模型）与其亲本品系 WKY 大鼠相比； (2) 将 WKY 大鼠的肠道微生物组改变为类似于 SHRSP 的肠道微生物组伴随着病理学改变 SHRSP 中发生的变化。改变 SHRSP 大鼠的肠道微生物组，使其与 WKY 大鼠相似减轻这些病理变化； (3) SHRSP大脑中细菌DNA含量比WKY大鼠多52%； (4) 革兰氏阴性细菌在大脑中细菌 DNA 总量中所占的比例要大得多。 SHRSP 与 WKY 大鼠相比； (5)脂多糖(LPS)，源自革兰氏菌的细菌内毒素与 WKY 大鼠相比，SHRSP 大脑中的阴性细菌显着增加。在具体目标 1 中，我们将确定是否可以通过控制肠道微生物群来产生或预防脑小血管病。如果肠道生态失调是 CSVD 的根本原因，那么我们应该能够在对照 WKY 大鼠中诱导 CSVD，即 SHRSP 的亲本菌株，通过诱导菌群失调。或者，我们应该能够废除或推迟通过预防菌群失调来预防 SHRSP 大鼠脑小血管病的发生。在具体目标 2 中，我们将识别肠道和大脑细菌以及与 CSVD 启动相关的细菌成分。 (a) 我们将分析细菌 DNA 通过对粪便、盲肠内容物和细菌 16s rRNA 基因进行测序，了解肠道和大脑的组成脑。使用靶向 qPCR，我们将进一步鉴定细菌到物种水平。 (b) 我们将确定是否完好无损使用 RT-PCR 以及 SHRSP 和 WKY 荧光原位杂交技术确定细菌驻留在大脑中老鼠。在具体目标 3 中，我们建议追踪细菌和细菌成分的运动，这是一个过程称为易位，从肠道到大脑。首先，我们将确定荧光标记的 LPS 和当将肽聚糖灌入 SHRSP 和 WKY 大鼠的肠道时，肽聚糖会追踪到大脑。其次，我们将聘用我们与记者一起设计的细菌，可以追踪从肠道到大脑的细菌，并确定是否革兰氏阳性在患有小脑小血管病的宿主体内，阴性细菌能够更有效地从肠道转移到大脑。如果如果我们的假设成立，那么胃肠道（GI）可以影响大脑的健康。建立肠道微生物组作为脑小血管病相关炎症的来源可能会极大地重新将我们的注意力集中在胃肠道上道作为大脑病理的潜在原因，并提供治疗干预的目标。