First-in-Human Study of MANP: A Novel ANP (Atrial Natriuretic Peptide) Analog in Human Hypertension

M-atrial natriuretic peptide (MANP) is a novel ANP (atrial natriuretic peptide) analog engineered to be an innovative particulate GC-A (guanylyl cyclase A) receptor activator. The rationale for its design was to develop a best-in-class GC-A activator with enhanced cGMP activating, natriuretic, aldosterone-suppressing, and blood pressure–lowering actions, compared with endogenous ANP, for the treatment of hypertension. Here, we report the first-in-human study on the safety, tolerability, neurohumoral, renal, and blood pressure–lowering properties of MANP in hypertension subjects. This was an open-label sequential single ascending dose design in which all subjects stopped all antihypertensive agents for 14 days before receiving a single subcutaneous injection of MANP. MANP was safe, well tolerated, activated cGMP, induced natriuresis, reduced aldosterone, and decreased blood pressure at or below the maximal tolerated dose. Thus, MANP has a favorable safety profile and produced expected pharmacological effects in human hypertension. Our results support further investigations of MANP as a potential future blood pressure–lowering, natriuretic and aldosterone-suppressing drug for hypertension especially resistant hypertension.

Metabolic Profiling and Metabolites Fingerprints in Human Hypertension: Discovery and Potential

Early detection of pathogenesis through biomarkers holds the key to controlling hypertension and preventing cardiovascular complications. Metabolomics profiling acts as a potent and high throughput tool offering new insights on disease pathogenesis and potential in the early diagnosis of clinical hypertension with a tremendous translational promise. This review summarizes the latest progress of metabolomics and metabolites fingerprints and mainly discusses the current trends in the application in clinical hypertension. We also discussed the associated mechanisms and pathways involved in hypertension’s pathogenesis and explored related research challenges and future perspectives. The information will improve our understanding of the development of hypertension and inspire the clinical application of metabolomics in hypertension and its associated cardiovascular complications.

Abstract 56: Proteome Profile Of Vascular Smooth Muscle Cells During Phenotypic Switching In Human Hypertension

Vascular smooth muscle cells (VSMCs) are key players in vascular dysfunction associated with hypertension, where phenotypic switch is a fundamental process. While various transcription factors have been implicated in this process, the proteomic signature associated with phenotypic switching in human hypertension is unknown. Using high fidelity proteomic analysis, we characterized the proteome profile of VSMC in human hypertension. VSMC derived from resistance arteries from normotensive (NT) and hypertensive (HT) subjects were studied. Protein expression and cell migration were assessed by immunoblotting and wound healing assay. VSMC proteins were labelled with isobaric tandem mass tags and identified by liquid chromatography tandem mass spectrometry. The oxidative proteome was assessed using stable isotope-labelled iodoacetamide to target free reduced cysteine thiols. VSMCs from HT subjects exhibit reduced expression of α-SMA (0.05±0.01 vs NT:0.20±0.03, p<0.05), increased expression of the proliferation marker, PCNA (0.162±0.3 vs NT:0.51±0.004, p<0.05), and increased migration (54.68±2.86 vs NT:23.37±8.36, p<0.05). The proteomic analysis identified 207 proteins upregulated in HT subjects (fold change>1.5, p<0.05). There were no changes in protein expression of pathways related to the contractile phenotype (MYH11, CNN1, TAGLN, TPM, CALD1). However, extracellular matrix (ECM) proteins such as COL1A1, COL9A1, COL10A1, FBN1, FBLN1 were increased in cells from HT (fold change>1.5, p<0.05), suggesting a switch to a fibroblast-like phenotype in hypertension. Expression of proteins related to the interferon and IL-1β pathways (IFIT1, IFIT2, IFIT3, MX1, MX2, ABCA1, ABCA2, IL1RAP, CD36, ICAM1) were also increased in cells from HT subjects (fold change>1.5, p<0.05). Considering the importance of oxidative stress in hypertension, we assessed the VSMC oxidative proteome. Results demonstrate that ECM proteins, such as COL11A1 and COL16A1, were highly oxidized in cells from HT (fold change>1.5, p<0.05). Our study provides new insights into the proteomic changes that define the vascular phenotype in hypertension and highlights candidate targets that may drive phenotypic switching associated with vascular injury in hypertension.

Abstract MP49: Single Cell Multiplex Immunophenotyping Using Mass Cytometry And CITE-Seq Reveals Decreases In Circulating PD-1 + CD8 + Memory T Cells With Features Of Exhaustion In Human Hypertension

Emerging evidence from animal models has demonstrated the importance of multiple innate and adaptive immune cells in hypertension. We hypothesized that the abundance and phenotype of circulating immune cell subsets are altered in human hypertension. To test this, we performed high dimensional single cell profiling of human peripheral blood mononuclear cells using mass cytometry. Unsupervised computational analysis revealed a 40% decrease in CD8 + memory T cells in hypertensive individuals. Using Phenograph to identify subsets of these cells revealed a selective 60% decrease in PD-1 + CD8 + memory T cells in hypertension. This observation was confirmed in a validation cohort using flow cytometry in which PD-1 + CD8 + memory T cells were significantly decreased 44% in hypertensive compared to control individuals. To determine the phenotype of these PD-1 + CD8 + memory T cells, we performed Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-Seq) on four control and four hypertensive individuals. Using antibodies to identify PD-1 + and PD-1 - CD8 + memory T cells, gene set enrichment analysis of the coordinate single cell transcriptomic data revealed that PD-1 + cells exhibit over-representation of features of both immunologically active effector T cells and hypofunctional exhausted T cells. Thus, clustering analysis of PD-1 + CD8 + memory T cells was performed which demonstrated 4 distinct subclusters. One of these subclusters was decreased in hypertension and exhibited selective expression of multiple inhibitory receptors characteristic of exhausted T cells. At the protein level, this subcluster was marked by expression of the inhibitory receptor LAG3 and low levels of CD57. Combining these markers to identify PD-1 + LAG3 + CD57 - CD8 + memory T cells permitted identification of exhausted cells which demonstrated a significant 35% decrease in hypertensive compared to control individuals using flow cytometry. Taken together, these results demonstrate novel and reproducible decreases in circulating PD-1 + CD8 + memory T cells with features of exhaustion in human hypertension. These findings provide new insights into the pathogenesis of human hypertension including loss and/or re-invigoration of exhausted T cells.

Impact of Renal Pelvic Denervation on Systemic Hemodynamics and Neurohumoral Changes in a Porcine Model

<b><i>Introduction:</i></b> The blood pressure (BP) response to arterial renal denervation (RDN) is variable. <b><i>Methods:</i></b> This study examined the effectiveness of renal pelvic denervation (RPD) on BP, heart rate (HR), norepinephrine (NE), and histopathology in 42 swine. NE levels were measured immediately, 7, 14, 30, and 90 days after RPD. Intra-arterial BP and HR were measured throughout RPD and after 14 days in 5 swine. <b><i>Results:</i></b> During the procedure, RPD immediately reduced systolic BP (−20.6 ± 18.3 mm Hg), diastolic BP (−6.0 ± 8.3 mm Hg), and HR (−5.4 ± 5.6 bpm), which remained decreased at follow-up. The porcine kidneys had a mean NE reduction of 76% directly post procedure and 60% after 7 days, 64% after 14 days, 57% after 30 days, and 65% after 90 days. Histopathological examination confirmed nerve ablation. <b><i>Conclusions:</i></b> These preliminary findings suggest that the renal pelvis nerve ablation is an encouraging target for RDN. Clinical trials are required to test the feasibility of RPD in human hypertension.

Gut Microbiota Dysbiosis in Human Hypertension: A Systematic Review of Observational Studies

Introduction: Hypertension is one of the major risk factors to human health and human studies on association between gut microbiota and hypertension or blood pressure have received increased attention. In the present study, we aim to evaluate gut microbiota dysbiosis in human hypertension using a method of systematic review.Methods: PubMed, EMBASE, and Web of Science databases were searched until March 2021 to identify eligible articles. Additional articles were also identified by searching specific authors in this field. Inclusion criteria were observational studies based on stool samples with hypertension group and control group. Newcastle-Ottawa quality assessment scale (NOS) was used to assess the quality of the included studies. PROSPERO registration number: CRD42020212219.Results: A total of 17 studies enrolling 9,085 participants were included. Fifteen of the enrolled studies showed good quality and two studies showed fair quality based on NOS. We found alpha diversity in hypertension decreased significantly and microbial structure can be separated compared with control groups. Gut microbiota of hypertension showed depletion of short chain fatty acids (SCFAs) producers and over-growth of some Proteobacteria and Bacteroidetes members. Up-regulation of lipopolysaccharide biosynthesis, phosphotransferase system, ABC transporters, etc. and down-regulation of some amino acid metabolism, etc. in hypertension were reported. Fecal SCFAs levels increased and plasma SCFAs levels decreased in hypertension. Stronger microbial interactions in hypertension were seen.Conclusion: In conclusion, gut microbiota dysbiosis was observed in hypertension, including decreased diversity, altered microbial structure, compositional change of taxa, alterations of microbial function, nutritional and immunological factors, and microbial interactions. Poor absorption and high excretion of SCFAs may play an important role in the pathogenesis of hypertension. These findings may provide insights into etiology study and new microbial-based therapies of hypertension.Systematic Review Registration: PROSPERO database, identifier CRD42020212219.

Further evidence against the role renal medullary perfusion in short-term control of arterial pressure in normotensive and mildly or overtly hypertensive rats

Earlier evidence from studies of rat hypertension models undermines the widespread view that the rate of renal medullary blood flow (MBF) is critical in control of arterial pressure (MAP). Here, we examined the role of MBF in rats that were normotensive, with modest short-lasting pressure elevation, or with overt established hypertension. The groups studied were anaesthetised Sprague-Dawley rats: (1) normotensive, (2) with acute i.v. norepinephrine-induced MAP elevation, and (3) with hypertension induced by unilateral nephrectomy followed by administration of deoxycorticosterone-acetate (DOCA) and 1% NaCl drinking fluid for 3 weeks. MBF was measured (laser-Doppler probe) and selectively increased using 4-h renal medullary infusion of bradykinin. MAP, renal excretion parameters and post-experiment medullary tissue osmolality and sodium concentration were determined. In the three experimental groups, baseline MAP was 117, 151 and 171 mmHg, respectively. Intramedullary bradykinin increased MBF by 45%, 65% and 70%, respectively, but this was not associated with a change in MAP. In normotensive rats a significant decrease in medullary tissue sodium was seen. The intramedullary bradykinin specifically increased renal excretion of water, sodium and total solutes in norepinephrine-treated rats but not in the two other groups. As previously shown in models of rat hypertension, in the normotensive rats and those with acute mild pressure elevation (resembling labile borderline human hypertension), 4-h renal medullary hyperperfusion failed to decrease MAP. Nor did it decrease in DOCA-salt model mimicking low-renin human hypertension. Evidently, within the 4-h observation, medullary perfusion was not a critical determinant of MAP in normotensive and hypertensive rats.