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Biomedical subjects

Rajeev Malhotra

Publications and source records attributed to Rajeev Malhotra.

3 recordsLinked to original sources
PubMed2026

Plasma proteomics and coronary artery calcium score: synergistic, concordant and contrasting predictions of cardiovascular outcomes in The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Coronary artery calcium (CAC) scores inform subclinical atherosclerotic cardiovascular disease (ASCVD) burden, helping guide preventative treatments. However, prediction of cardiovascular (CV) events by CAC is largely limited to ASCVD outcomes. This study investigated whether a previously validated proteomic test for predicting a broad composite of four-year CV events could enhance the prognostic utility of CAC. METHODS: We used a 27-protein CV risk score (Prot-CVR), derived from ~5,000 SomaScan&#x2122; Assay plasma protein measurements, to predict four-year risk of a composite CV and mortality outcome (myocardial infarction, stroke/TIA, heart failure hospitalization, death) in 2,122 participants with &#x2265;1 CV risk factors from the Multi-Ethnic Study of Atherosclerosis (MESA) observational cohort at exam 5 and compared predictions to CAC Agatston scores. Discriminatory performance was assessed using C-Index and 4-year area under the curve (AUC). Cox Proportional Hazard (CoxPH) ratios were calculated for the composite outcome, ASCVD outcome (myocardial infarction, resuscitated cardiac arrest, stroke, coronary heart disease death), and individual events. Changes in Prot-CVR and CAC scores from baseline to MESA exam 5 (+10-years) in CV event versus event-free participants were assessed using 2-tailed paired t-tests. CoxPH regression models of CV event status distributed by Prot-CVR, CAC, and relevant co-variates were evaluated for performance relative to individual models. RESULTS: Individual Prot-CVR and CAC models predicting the composite outcome had comparable 4-year AUCs, but Prot-CVR had a higher C-index (0.68 (0.65-0.70) versus 0.63 (0.60-0.65), p=0.001) and greater hazard ratios for the composite outcome (p<0.001), death (p<0.001), and heart failure (p=0.015). A combined CoxPH model of Prot-CVR + CAC + Age had a higher 4-year AUC (0.72, p<0.05) and C-Index (0.71, p<0.05) than Prot-CVR or CAC alone. Both Prot-CVR and CAC scores detected an increase in risk prior to an approaching CV event in ~10-year sensitivity-to-change analysis. For 49.6% of MESA population with CAC=0 at baseline, Prot-CVR was greater in composite event versus event free participants at 4 years (0.23 versus 0.15, p=0.006) and full follow-up (0.18 versus 0.13, p<0.001). CONCLUSION: Protein testing complements CAC for CV risk assessment although the improvement is modest. Prot-CVR may resolve which patients with CAC=0 are at heightened CV risk.

Journal Article↗
PubMed2025

Treatment of a severe vascular disease using a bespoke CRISPR-Cas9 base editor in mice.

Pathogenic missense mutations in the alpha actin isotype 2 (ACTA2) gene cause multisystemic smooth muscle dysfunction syndrome (MSMDS), a genetic vasculopathy that is associated with stroke, aortic dissection and death in childhood. Here we perform mutation-specific protein engineering to develop a bespoke CRISPR-Cas9 enzyme with enhanced on-target activity against the most common MSMDS-causative mutation ACTA2 R179H. To directly correct the R179H mutation, we screened dozens of configurations of base editors to develop a highly precise corrective A-to-G edit with minimal deleterious bystander editing that is otherwise prevalent when using wild-type SpCas9 base editors. We create a murine model of MSMDS that shows phenotypes consistent with human patients, including vasculopathy and premature death, to explore the in vivo therapeutic potential of this strategy. Delivery of the customized base editor via an engineered smooth muscle-tropic adeno-associated virus (AAV-PR) vector substantially prolongs survival and rescues systemic phenotypes across the lifespan of MSMDS mice, including in the vasculature, aorta and brain. Our results highlight how bespoke mutant-specific CRISPR-Cas9 enzymes can improve mutation correction with base editors.

Animals↗
PubMed2016

Androgen-sensitive hypertension associated with soluble guanylate cyclase-&#x3b1;1 deficiency is mediated by 20-HETE.

Dysregulated nitric oxide (NO) signaling contributes to the pathogenesis of hypertension, a prevalent and often sex-specific risk factor for cardiovascular disease. We previously reported that mice deficient in the &#x3b1;1-subunit of the NO receptor soluble guanylate cyclase (sGC&#x3b1;1 (-/-) mice) display sex- and strain-specific hypertension: male but not female sGC&#x3b1;1 (-/-) mice are hypertensive on an 129S6 (S6) but not a C57BL6/J (B6) background. We aimed to uncover the genetic and molecular basis of the observed sex- and strain-specific blood pressure phenotype. Via linkage analysis, we identified a suggestive quantitative trait locus associated with elevated blood pressure in male sGC&#x3b1;1 (-/-)S6 mice. This locus encompasses Cyp4a12a, encoding the predominant murine synthase of the vasoconstrictor 20-hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE). Renal expression of Cyp4a12a in mice was associated with genetic background, sex, and testosterone levels. In addition, 20-HETE levels were higher in renal preglomerular microvessels of male sGC&#x3b1;1 (-/-)S6 than of male sGC&#x3b1;1 (-/-)B6 mice. Furthermore, treating male sGC&#x3b1;1 (-/-)S6 mice with the 20-HETE antagonist 20-hydroxyeicosa-6(Z),15(Z)-dienoic acid (20-HEDE) lowered blood pressure. Finally, 20-HEDE rescued the genetic background- and testosterone-dependent impairment of acetylcholine-induced relaxation in renal interlobar arteries associated with sGC&#x3b1;1 deficiency. Elevated Cyp4a12a expression and 20-HETE levels render mice susceptible to hypertension and vascular dysfunction in a setting of sGC&#x3b1;1 deficiency. Our data identify Cyp4a12a as a candidate sex-specific blood pressure-modifying gene in the context of deficient NO-sGC signaling.

Androgens↗