Biology subjects

Moon, R.

Publications and source records attributed to Moon, R..

10 recordsLinked to original sources

bioRxiv2026

Multimodality Molecular Profiling Nominates Targetable Mechanisms in Progressive RV Dysfunction

BackgroundRight ventricular dysfunction (RVD) is a robust predictor of mortality in multiple cardiovascular diseases. Currently, it remains unclear whether the severity of RVD corresponds to distinct cellular and molecular alterations, and this has important implications for defining optimal therapeutic targets. To address this knowledge gap, we performed a multi-omics evaluation of pulmonary artery banded (PAB) pigs with differing degrees of RV compromise. MethodsPAB pigs were stratified into mild and severe RVD groups using an RV ejection fraction cutoff of 35%. RV tissue from control, mild RVD, and severe RVD animals was analyzed using single-nucleus RNA sequencing, mitochondrial and cytoplasmic proteomics, and phosphoproteomics. Histological analyses corroborated multi-omic findings. ResultsCardiac MRI revealed progressive structural and functional alterations in mild and severe RVD pigs. snRNAseq demonstrated that advancing RVD was associated with loss of cardiomyocytes, accumulation of efferocytosis-impaired macrophages, and dysregulated endothelial cells and pericytes. Combined transcriptomic and proteomic analyses showed escalating impairments of complex cardiomyocyte metabolism with worsening RVD. RV microvasculature was compromised with severe RVD as there were alterations in endothelial cell/pericyte genetic regulation, co-localization patterns in RV sections, and ectopic cardiomyocyte HIF1 expression. Analysis of both mitochondrial and global proteostasis revealed greater compromise in mitochondrial proteostasis, including downregulation of mitochondrial proteases, chaperones, and ribosomes. Paradoxically, cytoplasmic ribosomes were upregulated in severe RVD. The predicted kinome and phosphatome were uniquely altered in mild RVD as compared to severe RVD. Finally, integration of multi-omic approaches identified insufficient mitochondrial unfolded protein response, impaired macrophage efferocytosis, and activation of the ribotoxic stress response as potential contributors to severe RVD. ConclusionsOur multi-omic analysis defines the cellular and molecular landscape of progressive RVD and nominates druggable pathways that may promote progressive RV dysfunction. Future studies are needed to determine how targeting these pathways influences RV phenotypes.

physiology↗

bioRxiv2025

Impaired Lung BCAA Metabolism Promotes Ferroptosis and Resultant Pulmonary Arterial Hypertension-Associated Hepatopathy

BackgroundDysregulated branched chain amino acid (BCAA) homeostasis occurs in pulmonary arterial hypertension (PAH) as BCAA metabolites accumulate and cause metabolic alterations in pulmonary artery smooth muscle cells (PASMC). In other cells, altered BCAA metabolism promotes ferroptosis, a PAH-inducing metabolic pathway. However, the interplay between BCAAs, lung ferroptosis, and PAH is unexplored, as is the impact of PAH severity on liver molecular regulation, a key unknown as recent clinical data highlight the importance of the lung-right heart-liver axis in PAH outcomes. MethodsHuman metabolomic and transcriptomic studies examined BCAA metabolism and ferroptosis pathways. The relationship between BCAAs and ferroptotic-phenotypes in PASMCs was evaluated. Multi-omics and physiological analyses evaluated how modulation of BCAA catabolism impacted preclinical PAH multi-organ physiology. Confocal microscopy and proteomic analyses assessed hepatic alterations in human PAH. ResultsMetabolomic analyses identified alterations in BCAA metabolites across multiple physiological gradients in patients with pulmonary vascular disease. RNA sequencing demonstrated deficits in the BCAA catabolic and ferroptosis pathways in PAH lungs and smooth muscle cells. In vitro, excess BCAAs induced mitochondrial fragmentation, reactive oxygen species generation, and lipid peroxidation in PASMC. Moreover, BCAAs promoted PASMC death, which ferrostatin-1, a ferroptosis antagonist, rescued. BT2, a small-molecule inducer of BCAA catabolism, reduced PAH severity, improved RV function, and enhanced maximal exercise capacity in monocrotaline rats. BT2 blunted pro-ferroptotic changes in lung metabolites and proteins, and combatted peri-vascular complement deposition. In the liver, BT2 blocked mechanical shear stress phenotypes including hepatocyte nuclear expansion and restructured mitochondrial protein regulation and the metabolomic signature. Additionally, a low BCAA diet modestly combatted preclinical PAH severity. Finally, human PAH livers exhibited increased hepatocyte nuclear size and derangements in liver metabolic regulation. ConclusionsImpaired BCAA metabolism promotes PAH via ferroptosis. PAH severity is associated with hepatic pathological shear stress phenotypes and metabolic alterations, which are combatted by a BCAA-targeted therapy. Graphical Abstract/Summary Figure O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=152 SRC="FIGDIR/small/672819v1_ufig1.gif" ALT="Figure 1"> View larger version (55K): org.highwire.dtl.DTLVardef@1649980org.highwire.dtl.DTLVardef@199c40aorg.highwire.dtl.DTLVardef@1586fdorg.highwire.dtl.DTLVardef@15166c1_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2025

Proteomic and Metabolomic Profiling Nominates Druggable Targets and Biomarkers forPulmonary Arterial Hypertension-Associated Myopathy and Exercise Intolerance

BackgroundPulmonary arterial hypertension (PAH) is a rare but debilitating condition that causes exercise intolerance and ultimately death. Skeletal muscle derangements contribute to depressed exercise capacity in PAH, but the mechanisms underlying muscle dysfunction including the changes in muscle biology based on fiber type are understudied. MethodsWe evaluated exercise capacity, muscle histopathology, mitochondrial density, mitochondrial proteomics, and metabolomics/lipidomics of quadriceps (predominately fast fibers) and soleus (predominately slow fibers) muscles in the monocrotaline (MCT) rat model of PAH. ResultsMCT rats exhibited impaired exercise capacity. Surprisingly, there were divergent atrophic and metabolic remodeling in the quadriceps and soleus muscles of MCT rats. In the quadriceps, there was a mild atrophic response only in type II fibers. In contrast, both type I and II fibers atrophied in the soleus. Both muscles exhibited fibrotic infiltration, but mitochondrial density was reduced in the quadriceps only. Mitochondrial proteomics and tissue metabolomics/lipidomics profiling demonstrated the two muscles exhibited distinct responses as the quadriceps had impairments in oxidative phosphorylation/fat metabolism and storage of triacylglycerides. However, the soleus showed signs of proteasome deficiencies and alterations in phosphatidylcholine/phosphatidylethanolamine homeostasis. Finally, profiling of metabolites/lipids in the serum identified potential novel biomarkers of exercise intolerance in PAH including the dimethylarginine pathway, cysteine, and triacylglycerides. ConclusionOur data suggests differential cachectic and metabolic responses occur in PAH-induced myopathy. We nominate mitochondrial biogenesis and proteasome activation as potential druggable targets for PAH-myopathy.

systems biology↗

bioRxiv2025

17β-Estradiol Counteracts Pathological Microtubule Remodeling To Enhance Cardiac Function

The female-predominate sex hormone 17{beta}-estradiol exerts cardioprotective effects via multiple mechanisms. Available data demonstrate 17{beta}-estradiol modulates microtubule dynamics in vitro, but its effects on pathogenic microtubule remodeling in pressure-overloaded cardiomyocytes are unexplored. Here, we show 17{beta}-estradiol directly blunts microtubule polymerization in vitro, counteracts endothelin-mediated microtubule remodeling in iPSC-cardiomyocytes, and mitigates microtubule stabilization in pulmonary artery banded right ventricular cardiomyocytes. 17{beta}-estradiol treatment blunts cardiomyocyte and nuclear hypertrophy, restores t-tubule architecture, and prevents mislocalization of connexin-43 in RV cardiomyocytes of pulmonary artery banded rats. These cellular phenotypes are paired with significant improvements in RV function. Thus, we propose 17{beta}-estradiol exerts cardioprotective effects via direct modulation of microtubules in addition to its well ascribed signaling functions.

physiology↗

bioRxiv2025

Glycoprotein 130 Antagonism Counteracts Metabolic and Inflammatory Alterations to Enhance Right Ventricle Function in Pulmonary Artery Banded Pigs

BackgroundRight ventricular dysfunction (RVD) is a risk factor for death in multiple cardiovascular diseases, but RV-enhancing therapies are lacking. Inhibition of glycoprotein-130 (GP130) signaling with the small molecule SC144 improves RV function in rodent RVD via anti-inflammatory and metabolic mechanisms. However, SC144s efficacy and molecular effects in a translational large animal model of RVD are unknown. Methods4-week-old castrated male pigs underwent pulmonary artery banding (PAB). After 3 weeks, PAB pigs were randomized into 2 groups (daily injections of SC144 [2.2 mg/kg, PAB-SC144, n=5] or vehicle [PAB-Veh, n=5] for 3 weeks). Five age-matched pigs served as controls. Cardiac MRI quantified RV size/function. Right heart catheterization evaluated hemodynamics. Single-nucleus RNA sequencing delineated cell-type specific changes between experimental groups. Electron microscopy evaluated RV mitochondrial morphology. Phosphoproteomics identified dysregulated RV kinases. Lipidomics and metabolomics quantified lipid species and metabolites in RV tissue. Quantitative proteomics examined RV mitochondrial protein regulation. ResultsSC144 significantly improved RV ejection fraction (Control: 60{+/-}4%, PAB-Veh: 22{+/-}10%, PAB-SC144: 37{+/-}6%) despite similar RV afterload. Single-nucleus RNA sequencing demonstrated PAB-Veh pigs had lower cardiomyocyte and higher macrophage/lymphocyte/pericyte/endothelial cell abundances as compared to control, and many of these changes were blunted by SC144. SC144 combatted the downregulation of cardiomyocyte metabolic genes induced by PAB. Kinome enrichment analysis suggested SC144 counteracted RV mTORC1 activation. Correspondingly, SC144 rebalanced RV autophagy pathway proteins and improved mitochondrial morphology. Integrated lipidomics, metabolomics, and proteomics analyses revealed SC144 restored fatty acid metabolism. Finally, CellChat analysis revealed SC144 restored pericyte-endothelial cell cross-talk. ConclusionGP130 antagonism blunts elevated immune cell abundance, reduces pro-inflammatory gene transcription in macrophages and lymphocytes, rebalances autophagy and preserves fatty acid metabolism in cardiomyocytes, and restores endothelial cell and pericyte communication to improve RV function.

physiology↗

bioRxiv2024

Lactobacillus Restructures the Micro/Mycobiome to Combat Glycoprotein-130 Associated Microtubule Remodeling and Right Ventricular Dysfunction in Pulmonary Arterial Hypertension

Emerging data demonstrate systemic and local inflammation regulate right ventricular (RV) adaption in preclinical and human pulmonary arterial hypertension (PAH). Pathological RV inflammation is targetable as antagonism of glycoprotein-130 (GP130) signaling counteracts pathological microtubule remodeling and improves RV function in rodents. Microtubules control several aspects of cardiomyocyte biology including cellular and nuclear size/structure, t-tubule homeostasis, and the proper localization of connexin-43. The intestinal microbiome regulates systemic inflammation, but the impact of the gut microbiome on the GP130-microtubule axis in RV failure is unknown. Here, we examined how the anti-inflammatory bacteria, Lactobacillus, modulated cellular and physiological RV phenotypes in preclinical and clinical PAH. Lactobacillus supplementation restructured the gut micro/mycobiome, suppressed systemic inflammation, combatted pathological GP130-mediated RV cardiomyocyte microtubule remodeling, and augmented RV function in rodent PAH. Moreover, Lactobacillus was associated with superior RV adaption in human PAH. These data further support the hypothesis that inflammation negatively impacts RV adaption in PAH, and identify the gut microbiome as a potentially targetable regulator of RV function in PAH.

physiology↗

bioRxiv2024

Ferroptosis Inhibition Combats Metabolic Derangements and Improves Cardiac Function in Pulmonary Artery Banded Pigs

Right heart failure (RHF) is a leading cause of mortality in multiple cardiovascular diseases and preclinical and human data suggest impaired metabolism is a significant contributor to right-sided cardiac dysfunction. Ferroptosis is a nonapopotic form of cell death driven by impaired metabolism. Rodent data suggests ferroptosis inhibition can restore mitochondrial electron transport chain function and enhance cardiac contractility in left heart failure models, but the effects of ferroptosis inhibition in translational large animal models of RHF are unknown. Here, we showed ferrostatin-1 mediated ferroptosis antagonism improve right heart structure and function in pulmonary artery banded pigs. Molecularly, ferrostatin-1 restored mitochondrial cristae structure and combatted downregulation of electron transport chain proteins. Metabolomics and lipidomics analyses revealed ferrostatin-1 improved fatty acid metabolism. Thus, these translational data suggest ferroptosis may be a therapeutic target for RHF. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=139 SRC="FIGDIR/small/590907v2_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@9c36fforg.highwire.dtl.DTLVardef@1deda21org.highwire.dtl.DTLVardef@1c2e4e1org.highwire.dtl.DTLVardef@409181_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2021

Getting close to nature - Plasmodium knowlesi reference genome sequences from contemporary clinical isolates

Plasmodium knowlesi, a malaria parasite of old-world macaque monkeys, is used extensively to model Plasmodium biology. Recently P. knowlesi was found in the human population of Southeast Asia, particularly Malaysia. P. knowlesi causes un-complicated to severe and fatal malaria in the human host with features in common with the more prevalent and virulent malaria caused by Plasmodium falciparum. As such P. knowlesi presents a unique opportunity to inform an experimental model for malaria with clinical data from same-species human infections. Experimental lines of P. knowlesi represent well characterised genetically static parasites and to maximise their utility as a backdrop for understanding malaria pathophysiology, genetically diverse contemporary clinical isolates, essentially wild-type, require comparable characterization. The Oxford Nanopore PCR-free long-read sequencing platform was used to sequence P. knowlesi parasites from archived clinical samples. The sequencing platform and assembly pipeline was designed to facilitate capturing data on important multiple gene families, including the P. knowlesi schizont-infected cell agglutination (SICA) var genes and the Knowlesi-Interspersed Repeats (KIR) genes. The SICAvar and KIR gene families code for antigenically variant proteins that have been difficult to resolve and characterise. Analyses presented here suggest that the family members have arisen through a process of gene duplication, selection pressure and variation. Highly evolving genes tend to be located proximal to genetic elements that drive change rather than regions that support core gene conservation. For example, the virulence-associated P. falciparum erythrocyte membrane protein (PfEMP1) gene family members are restricted to relatively unstable sub-telomeric regions. In contrast the SICAvar and KIR genes are located throughout the genome but as the study presented here shows, they occupy otherwise gene-sparse chromosomal locations. The novel methods presented here offer the malaria research community new tools to generate comprehensive genome sequence data from small clinical samples and renewed insight into these complex real-world parasites. Author summaryMalaria is a potentially severe disease caused by parasite species within genus Plasmodium. Even though the number of cases is in decline there were over 200 million reported cases of malaria in 2019 that resulted in >400,000 deaths. Despite huge research efforts we still do not understand precisely how malaria makes some individuals very ill and by extension how to successfully augment and manage severe disease. Here we developed a novel method to generate comprehensive robust genome sequences from the malaria parasite Plasmodium knowlesi collected from clinical samples. We propose to use the method and initial data generated here to begin to build a resource to identify disease associated genetic traits of P. knowlesi taken from patients samples. In addition to the methodology, what further sets this work apart is the unique opportunity to utilize same-species experimental P. knowlesi parasites to discover a potential role for particular parasite traits in the differential disease progression we observe in patients with P. knowlesi malaria. While we developed the methods to study severe malaria, they are affordable and accessible, and offer the wider malaria research community the means to add context and insight into real-world malaria parasites.

genomics↗

bioRxiv2021

BMP signaling underlies the craniofacial heterochrony in phyllostomid bats, a hyperdiverse mammal group

The potential for variation and the capacity to evolve in response to ecological opportunity are important aspects of an adaptive radiation. Identifying the origin of phenotypic variation, in which natural selection might act upon, is a major goal of evolutionary developmental biology. The New World leaf-nosed bats (phyllostomids) are a textbook example of an adaptive radiation. Their cranial morphology is diverse along relative facial length, which is related to their diets. We previously used geometric morphometrics to reveal peramorphosis, a type of heterochrony, in the cranial evolution among phyllostomid bats. We then demonstrated that the mechanism of peramorphic diversity in phyllostomid rostrum length resulted from altered cellular proliferation. Here, we investigate the progenitors of the face, the cranial neural crest, and a key signaling pathway related to their proliferation and differentiation into mature tissues: the bone morphogenetic protein (BMP). With geometric morphometrics, immunofluorescence, and confocal imaging--in three phyllostomid species and one outgroup bat species--we show the molecular patterns that underlie the adaptive and innovative traits seen in phyllostomid bats. Then, with mouse genetics, we mimic the BMP molecular pattern observed in nectar feeding bats and recapitulate the elongated morphological variation in mice. Surprisingly, we also observe an expansion in the nose-tip of mice, akin to the expanding leaf-nose tissue in phyllostomid bats. These data, combined with the mouse genetics literature on BMP signaling, suggest the BMP developmental pathway plays a central role in shaping the craniofacial variation necessary for adaptation in bats. Further, we speculate that the BMP signaling pathway could underlie other bizarre facial phenotypes in mammals that are derived from frontonasal mesenchyme, such as the proboscis. Overall, this study combines a comparative framework to developmental data, with a genetic approach, to directly investigate the role of development on complex morphology.

evolutionary biology↗

bioRxiv2021

The chromatin remodelling factor Chd7 protects auditory neurons and sensory hair cells from stress-induced degeneration

Neurons and sensory cells are particularly vulnerable to oxidative stress due to their high oxygen demand during stimulus perception and transmission1-4. The mechanisms that protect them from stress-induced death and degeneration remain elusive. Here we show that embryonic deletion of the chromodomain helicase DNA-binding protein 7 (CHD7) in auditory neurons or hair cells leads to sensorineural hearing loss due to postnatal degeneration of both cell types. Mechanistically, we demonstrate that CHD7 controls the expression of major stress pathway components. In its absence, hair cells are hypersensitive, dying rapidly after brief exposure to stress inducers, suggesting that sound at the onset of hearing triggers their degeneration. In humans, CHD7 haploinsufficiency causes CHARGE syndrome, a disorder affecting multiple organs including the ear5,6. Our findings suggest that CHD7 mutations cause developmentally silent phenotypes that predispose cells to postnatal degeneration due to a failure of protective mechanisms.

developmental biology↗