Brain-Gut Microbiome-Immune Axis in Hypertension



 DESCRIPTION (provided by applicant): Hypertension (HTN) is the most prevalent modifiable risk for cardiovascular disease (CVD) and disorders directly influencing CVD (i.e. diabetes, chronic kidney disease, obstructive sleep apnea, etc.). Despite lifestyle changes and advances in drug therapy, ~20% of all HTN patients are resistant to (or require ≥3) antihypertensive drugs Resistant HTN (R-HTN) is generally neurogenic in origin and associated with a dysfunctional autonomic nervous system. Few treatment options remain available following the recent failure of percutaneous renal artery sympathetic denervation (SYMPLICITY HTN-3, PRAUGE-15). Thus, a mechanism- based breakthrough is imperative to develop novel strategies to control and potentially cure R-HTN. We believe that our evidence of gut dysbiosis and dysfunctional brain-gut-bone marrow (BM) interaction in R-HTN represents this breakthrough. We propose a brain-gut-BM dysfunctional interaction hypothesis: HTN risk factors increase sympathetic drive by influencing autonomic brain regions, setting in motion a sequence of critical signaling events key to establishing neurogenic R-HTN. This includes increased gut stiffness, permeability and inflammation leading to gut microbial dysbiosis. Dysbiosis-associated changes increase BM production of myeloid progenitors and other proinflammatory cells. This contributes to increased peripheral inflammation, and neuroinflammation, as some BM-derived myeloid progenitors migrate to the paraventricular nucleus (PVN), and differentiate into microglia. Therefore, we hypothesize that establishment of R-HTN is caused by an increased SNA-mediated gut dysbiosis, activity of BM proinflammatory cells, and neuroinflammation. Three specific aims are proposed to support/refute this dysfunctional brain-gut-BM linked neuroinflammation hypothesis in R-HTN: Aim 1 will investigate the hypothesis that increased gut SNA is critical in enhanced intestinal permeability, proinflammatory conditions, and microbial dysbiosis in HTN. Aim 2 will define how gut dysbiosis increases production of proinflammatory progenitors and neuroinflammation in HTN. Aim 3 will evaluate the hypothesis that human R-HTN is linked to profound gut microbial dysbiosis and that treatment with minocycline will reverse the dysbiosis and lower BP. These studies will utilize state-of-the-art integrative physiological genomic techniques and will be conducted by an exceptional team of investigators. Thus, the outcome of this mechanism-based translational study spanning from mice to humans will provide the basis for development of paradigm-changing therapeutic approaches for R-HTN without involving more anti-hypertensive drugs.