Gut Dysbiosis and Cerebral Small Vessel Disease

肠道菌群失调和脑小血管疾病

• 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
• 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

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，是脑血管病的主要原因。 认知障碍在这个提议中，我们提出了一个新的想法，即来自肠道微生物群的抗原 构成了CSVD炎症的基本来源。我们认为肠道生态失调 允许细菌和细菌成分移位肠道上皮屏障， 进入大脑，在那里它们启动和维持炎症，这是发展所必需的。 CSVD这一假设得到了强有力的初步数据的支持：（1）肠道生态失调发生在自发的 高血压卒中易感大鼠（SHRSP），CSVD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， SHRSP发生变化。改变SHRSP大鼠的肠道微生物组以类似于WKY大鼠 （3）SHRSP脑内细菌DNA含量比WKY大鼠高52%; (4)革兰氏阴性细菌在大脑中的细菌DNA总量中所占的比例要大得多， SHRSP与WKY大鼠比较;（5）脂多糖（LPS）、革兰氏阴性杆菌来源的细菌内毒素 阴性细菌，在SHRSP的脑中与WKY大鼠相比显著增加。具体目标1， 将确定CSVD是否可以通过操纵肠道微生物群来产生或预防。如果肠 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， SHRSP的亲本菌株，通过诱导生态失调。或者，我们应该能够废除或推迟 SHRSP大鼠CSVD的发病通过防止生态失调。在具体目标2中，我们将识别肠道和大脑细菌 以及与CSVD的起始有关的细菌成分。(a)我们会分析细菌DNA 通过对粪便、盲肠内容物和粪便中的细菌16 s rRNA基因进行测序， 个脑袋使用靶向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 利用SHRSP和WKY的RT-PCR和荧光原位杂交， 大鼠在具体目标3中，我们提出跟踪细菌和细菌成分的运动， 从肠道转移到大脑首先，我们将确定荧光标记的LPS和 当强饲到SHRSP和WKY大鼠的肠道中时，肽聚糖追踪到脑。第二，我们将采用 我们用报告基因设计了细菌，以跟踪细菌从肠道到大脑，并确定克- 在发生CSVD的宿主中，阴性细菌能够更有效地从肠道转移到大脑。如果 我们的假设是有效的，那么胃肠道（GI）可以影响大脑的健康。建立肠道 微生物组作为与CSVD相关的炎症来源可能会极大地重新关注GI 作为脑病理学潜在原因，以及提供治疗干预的靶点。