Biology subjects

Hemnes, A. R.

Publications and source records attributed to Hemnes, A. R..

5 recordsLinked to original sources

bioRxiv2026

Metabolomic Network Analysis Reveals Reorganization of Lipid and Steroid Programs Linked to Right Ventricular-Pulmonary Vascular Function in Pulmonary Hypertension

BackgroundPulmonary arterial hypertension (PAH) is characterized by circulating metabolic alterations, but whether these reflect disease-specific metabolic programs or reorganization of normal metabolic architecture, and how they relate to right ventricular-pulmonary vascular function (RV-PV), remains unclear. We hypothesized that the PAH metabolome is organized into biologically coherent, co-regulated metabolic modules whose relationships to RV-PV function would provide insight into known and novel metabolic pathways. MethodsWe applied weighted gene co-expression network analysis (WGCNA) to untargeted metabolomic data from 412 PAH patients enrolled in the multicenter PVDOMICS study. Module preservation analysis was performed in 85 healthy controls, with external replication in an independent single-center pulmonary hypertension cohort of 89 patients. ResultsWGCNA identified 16 distinct metabolic modules organized around biologically coherent programs. A coherent fatty acid axis, spanning substrate pools, {beta}-oxidation intermediates, and conjugated fatty acid disposal products, formed a central organizing structure, with downstream fatty acid oxidation modules strongly associated with adverse hemodynamics and worse RV-pulmonary artery (PA) coupling. Acylcholine-enriched and 5-reduced androgen metabolite modules were associated with favorable hemodynamic indices. Module architecture was largely preserved in healthy controls, with subtle disease-associated modular reorganization, rather than emergence of novel modules, observed in PAH. Core modules were recovered in the replication cohort with conserved hub metabolites. ConclusionsThese findings establish a systems-level framework demonstrating that PAH involves structured intensification and reorganization of interconnected metabolic programs associated with favorable and adverse RV-PV phenotypes. This work provides new insight into the metabolic architecture underlying PAH and identifies coordinated metabolic pathways linked to pulmonary vascular and right ventricular function.

physiology↗

bioRxiv2025

Wnt5a-mediated Adipo-Cardiac Interorgan Communication in HFpEF

BackgroundObesity is an important risk factor in heart failure with preserved ejection fraction (HFpEF), but the precise mechanisms that drive obesity-associated cardiac remodeling are not well understood. Our previous work has shown that increased expression of the natriuretic peptide clearance receptor (Nprc) may drive cardiac remodeling in response to high fat diet. In this study, we hypothesized that Nprc plays a central role in preventing and reversing experimental HFpEF. MethodsNprc knockout mice were generated to induce global, cardiomyocyte-specific, or adipocyte-specific disruption of the Nprc (Npr3) gene. HFpEF was induced by the 2-hit stress of L-NAME and high fat diet. Outcomes measured included echocardiography, exercise endurance, invasive catheterization, and histologic assessment. Differential gene expression in adipocyte Nprc knockout visceral adipose tissue was investigated via bulk RNA sequencing and validated by RT-qPCR and culture of H9C2 cells with or without Wnt5a treatment. Adipocyte-mediated Wnt ligand release was interrupted in vivo via LGK974 injection in mice subjected to HFpEF conditions. ResultsGlobal inducible Nprc knockout prevented and reversed structural, hemodynamic, echocardiographic, and exercise tolerance features of HFpEF. This effect was found to be driven by adipocyte-specific, not cardiomyocyte-specific Nprc expression. Bulk RNA sequencing of adipocyte-specific Nprc knockout in peri-gonadal visceral adipose tissue identified downregulation of several secretory pathways, including Wnt pathways. Wnt5a was identified as one of the most downregulated genes by RNA sequencing and specifically validated by qPCR. Wnt5a exposure increased cardiomyocyte hypertrophy in vitro, and LGK974 (PORCN inhibitor) treatment in vivo decreased circulating Wnt5a levels and improved cardiac remodeling in HFpEF. ConclusionsOur study identifies a novel crosstalk mechanism between cardiomyocytes and adipocytes in obesity-associated HFpEF driven by natriuretic peptide-mediated inhibition of release of Wnt5a from adipocytes.

molecular biology↗

bioRxiv2025

Reducing Reactive Lipids Improves Cardiac Metabolic and Diastolic Function in Pulmonary Hypertension Models

BackgroundReactive oxygen species are increased across most pulmonary hypertension (PH) etiologies, resulting in increased reactive lipid dicarbonyls, which form protein adducts and impair mitochondrial function. We hypothesized that reducing reactive lipids would reduce right ventricular systolic pressure (RVSP) and improve cardiac function by eliminating protein-lipid damage feedback loops. MethodsWe used 2-hydroxybenzylamine (2-HOBA) to scavenge reactive lipids in three complimentary mouse models of PH: AKR-high fat diet (HFD, metabolic stress), LNAME-HFD (cardiometabolic syndrome), and pulmonary artery banding (PAB, load stress). Cardiac function was measured by echocardiography and catheterization. RV energy metabolism was determined by oxygraphy. Mass spectrometry analyzed lipids and ceramides; O-link and RNA-Seq evaluated proteomic and gene expression in lungs, RV, and LV. ResultsReducing reactive lipids with 2-HOBA resulted in a [~]10% reduction in RVSP, reduced diastolic dysfunction, reduced plasma lipids and ceramides, and normalized RV fatty acid oxidation that was severely impaired in the AKR-HFD and PAB models. Proteomic and RNA changes in the lungs, RV, and LV suggested reduced oxidative damage and inflammatory signaling and altered developmental and actin organization signaling; these changes are plausibly associated with the improved adaptation. Some changes were sex specific, including a 4x higher cardiac fatty acid content in males than females. ConclusionsReactive lipid scavenging improves cardiac metabolic and diastolic function and pulmonary vascular resistance through restoration of mitochondrial function and reduced oxidative protein damage. The magnitude of hemodynamic improvement combined with substantial diastolic function improvement suggests clinical potential, particularly for PH patients with metabolic comorbidities.

molecular biology↗

bioRxiv2024

Pulmonary primary oxysterol and bile acid synthesis as a predictor of outcomesin pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare and fatal vascular disease with heterogeneous clinical manifestations. To date, molecular determinants underlying the development of PAH and related outcomes remain poorly understood. Herein, we identify pulmonary primary oxysterol and bile acid synthesis (PPOBAS) as a previously unrecognized pathway central to PAH pathophysiology. Mass spectrometry analysis of 2,756 individuals across five independent studies revealed 51 distinct circulating metabolites that predicted PAH-related mortality and were enriched within the PPOBAS pathway. Across independent single-center PAH studies, PPOBAS pathway metabolites were also associated with multiple cardiopulmonary measures of PAH-specific pathophysiology. Furthermore, PPOBAS metabolites were found to be increased in human and rodent PAH lung tissue and specifically produced by pulmonary endothelial cells, consistent with pulmonary origin. Finally, a poly-metabolite risk score comprising 13 PPOBAS molecules was found to not only predict PAH-related mortality but also outperform current clinical risk scores. This work identifies PPOBAS as specifically altered within PAH and establishes needed prognostic biomarkers for guiding therapy in PAH. One-Sentence SummaryThis work identifies pulmonary primary oxysterol and bile acid synthesis as altered in pulmonary arterial hypertension, thus establishing a new prognostic test for this disease.

systems biology↗

bioRxiv2023

Myeloid Cell-Derived IL1β Contributes to Pulmonary Vascular Remodeling in Heart Failure with Preserved Ejection Fraction

BackgroundPulmonary hypertension (PH) in heart failure with preserved ejection fraction (HFpEF) is a common and highly morbid syndrome, but mechanisms driving PH-HFpEF are not well understood. We sought to determine whether a well-accepted murine model of HFpEF also displays features of PH in HFpEF, and we sought to identify pathways that might drive early remodeling of the pulmonary vasculature in HFpEF. MethodsEight week old male and female C57/BL6J mice were given either L-NAME and high fat diet (HFD) or control water/diet for 2,5, and 12 weeks. Bulk RNA sequencing and single cell RNA sequencing was performed to identify early and cell-specific pathways that might regulate pulmonary vascular remodeling in PH-HFpEF. Finally, clodronate liposome and IL1{beta} antibody treatments were utilized to deplete macrophages or IL1{beta}, respectively, to assess their impact on pulmonary vascular remodeling in HFpEF. ResultsMice given L-NAME/HFD developed PH, small vessel muscularization, and right heart dysfunction after 2 weeks of treatment. Inflammation-related gene ontologies were over-represented in bulk RNA sequencing analysis of whole lungs, with an increase in CD68+ cells in both murine and human PH-HFpEF lungs. Cytokine profiling of mouse lung and plasma showed an increase in IL1{beta}, which was confirmed in plasma from patients with HFpEF. Single cell sequencing of mouse lungs also showed an increase in M1-like, pro-inflammatory populations of Ccr2+ monocytes and macrophages, and transcript expression of IL1{beta} was primarily restricted to myeloid-type cells. Finally, clodronate liposome treatment prevented the development of PH in L-NAME/HFD treated mice, and IL1{beta} antibody treatment also attenuated PH in L-NAME/HFD treated mice. ConclusionsOur study demonstrated that a well-accepted model of HFpEF recapitulates features of pulmonary vascular remodeling commonly seen in patients with HFpEF, and we identified myeloid cell derived IL1{beta} as an important contributor to PH in HFpEF.

cell biology↗