Soni Savai Pullamsetti

Rationale: Only a subset of patients with non-small cell lung cancer (NSCLC) benefit from immunotherapy, and this is partly due to limited understanding of how oncogenic mutations shape the tumor microenvironment (TME). Objectives: To define how EGFR and KRAS mutations influence the spatial organization and immune composition of the NSCLC TME. Methods: We conducted 38-marker high-plex immunofluorescence to 197 NSCLC tumors (>2 million cells) stratified by EGFR and KRAS genotypes. Quantitative phenotyping and spatial analyses, including cellular neighborhoods (CNs), nearest neighbors (NNs = 5-20), and spatial proximity profiling (25-100 μm), were performed to assess immune architecture and clinical correlations. Measurements and Main Results: EGFR- and KRAS-mutant tumors showed higher tumor cell density and reduced immune infiltration compared with wild-type tumors. Both mutation types were associated with depletion of cytotoxic T cells, dendritic cells, and granulocytes, while EGFR-mutant tumors showed enrichment of M2-like tumor-associated macrophages (TAMs). Cellular neighborhoods analysis identified 14 spatial clusters, with reduced cytotoxic and helper T cell–rich neighborhoods in mutant tumors. Nearest neighbors analysis revealed shorter distances between M2-like TAMs in EGFR-mutant tumors and greater immune exclusion in nonmutants. Spatial proximity revealed higher densities of regulatory T cells and TAMs near tumor cells in KRAS-mutant tumors. All spatial metrics correlated significantly with prognosis in Cox proportional hazards models, highlighting immune cell positioning as an important predictor of outcome. Conclusions: EGFR- and KRAS-mutant tumors remodel the NSCLC immune landscape, creating distinct immunosuppressive and immune-excluded niches. Spatial proteomics reveals prognostic immune architectures that may guide mutation-directed immunotherapy strategies.

Local immune cell activation and vascular remodelling are characteristic pathogenic features of pulmonary arterial hypertension (PAH). HIV and schistosome infections have been individually associated with PAH. However, whether co-infection with these pathogens has a distinct impact on the development of pulmonary vascular disease remains poorly understood, partly due to the lack of experimental animal models. In a novel non-infectious model of HIV and Schistosoma pulmonary co-exposure based on lung embolisation of S. mansoni eggs in HIV-transgenic (HIV) mice, we previously reported exacerbated endothelial remodelling and dysfunction, along with increased pulmonary arterial pressure; which were associated with a unique profile of pro-inflammatory cytokines in the lung. In the present study, we used flow cytometric analysis of isolated lung leukocytes and immunofluorescence staining to characterise the pulmonary immune cell landscape associated with individual or combined exposure to HIV and schistosome. Compared with mice exposed to HIV (untreated HIV mice) or schistosome (egg-treated wild-type mice), co-exposed (egg-treated HIV mice) animals showed significantly increased numbers of interstitial and alveolar macrophages, patrolling-type monocytes, NKT and γδ T cells, and reduced CD8⁺ αβ T cells. Other lung immune cells, including inflammatory-type monocytes, eosinophils/neutrophils, dendritic cells, CD4⁺ αβ T cells, NK cells and B cells were not significantly affected in the co-exposure condition. Taken together, these results show for the first time that combined pulmonary exposure to HIV and Schistosoma, as it may occur in co-infected individuals, alters the local immune cell landscape in a manner distinct from that of individual exposure. Furthermore, these findings may contribute to a better understanding of the complex inflammatory processes involved in the pathogenesis of PAH, thereby supporting the development of therapies targeting pathogenic immune cells in pulmonary vascular disease associated with HIV and Schistosoma co-morbidity.

Rationale: RV adaptation in pulmonary hypertension is sexually dimorphic and more preserved in women. NLRP3 inflammasome activation contributes to RV failure (RVF) development. However, regulators and downstream effects of NLRP3 activation in the RV remain unknown. Objectives: We investigated whether NLRP3 inflammasome activation in RVF is sexually dimorphic, whether NLRP3 is active in RV cardiomyocytes (RVCMs) and causes RVCM contractile dysfunction, and whether 17β-estradiol (E2) and its receptor ERα attenuate this process. Methods: We studied RV tissues from PAH patients with RVF, RV tissues and RVCMs isolated from wild-type and ERα loss-of-function mutant rats with RVF, isolated perfused rat hearts, and human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes. NLRP3 activation was assessed via RNA-sequencing, proteomics, immunostaining, and downstream target quantification. RV contractility was assessed via pressure-volume loops, perfused heart studies, and contractility and calcium assessments in isolated RVCMs. Measurements and Main Results: NLRP3 was upregulated in RVCMs during RVF and resulted in altered RVCM calcium handling and RVCM contractile dysfunction. In human RVs, hiPSC-cardiomyocytes and rat RVs, NLRP3 activation and NLRP3-induced RVCM contractile dysfunction were sexually dimorphic and male-biased. Ovariectomy and loss of ERα in females eliminated this sex bias. E2, via ERα, prevented RVCM NLRP3 activation and NLRP3-induced RVCM contractile dysfunction in males and ovariectomized females during both acute and chronic RV pressure overload. ERα directly interacted with NLRP3. Conclusions: NLRP3-driven RVCM contractile dysfunction is male-biased. E2 inhibits NLRP3 through ERα to preserve RVCM contractility. Targeting E2-ERα-NLRP3 signaling may offer novel therapeutic strategies for RVF in low estrogen states. Impact: This is the first study to define a novel estradiol-estrogen receptor α-NLRP3 axis that modulates RV cardiomyocyte function and RV adaptation in pulmonary hypertension. We demonstrate for the first time that NLRP3 activation is therapeutically targetable in low estrogen states via NLRP3 inhibitors or 17β-estradiol. These findings have direct implications for therapeutic strategies aimed at preserving or restoring RV contractile function in pulmonary hypertension, a current area of unmet clinical need.

BACKGROUND: Early apoptosis of pulmonary artery endothelial cells (PAECs) is a driver of vascular remodeling and pulmonary hypertension (PH), but its regulation is poorly defined. Adenosine deaminase acting on RNA 1 (ADAR1, gene name ADAR ) is an RNA editing enzyme that converts adenosine to inosine (A-to-I) in RNA transcripts and participates in RNA metabolism. While deficiency in ADAR1-mediated RNA editing stimulates cellular innate immunity signaling and can promote apoptosis, the exact ADAR1 RNA editing targets and downstream mechanisms regulating PAEC survival are unknown. We sought to define the functions and targets of ADAR1-dependent RNA editing that control pulmonary endothelial pathophenotypes in PH. METHODS: ADAR1 or Nocturnin (NOCT) expression and A-to-I RNA editing levels were evaluated in human PAH lungs by immunofluorescent staining and single cell RNA sequencing, respectively. Mice carrying a human missense ADAR mutation and genetic deletion of Noct with interleukin-6 (il6) transgene were studied in chronic hypoxia-induced PH in vivo models. RESULTS: ADAR1 expression was downregulated in the pulmonary vascular endothelium and in lung tissue of human and mouse PH. Global A-to-I RNA editing was decreased in lungs from PAH patients and hypoxic PH mice. In vitro, hypoxia, a PH trigger, downregulated ADAR1 in PAECs. Circadian gene NOCT was identified as a direct ADAR1 target which carries two active A-to-I RNA editing sites in the 3’UTR. In human PAH lungs, NOCT editing levels were reduced, while NOCT protein level increased. Correspondingly, in vitro, ADAR silencing increased NOCT mRNA levels, thus inducing dsRNA-MDA5 sensing interferon signaling and PAEC apoptosis. Importantly, silencing of NOCT reversed these changes. Forced NOCT expression phenocopied the effect of ADAR1 knockdown, upregulating interferon signaling molecules and increasing apoptosis. Chronically hypoxic PH mice carrying human ADAR mutation displayed worsened PH. Forced adeno-associated virus (AAV) expression of Adar improved monocrotaline-induced PH in rats. Genetic deletion of Noct mitigated PH in hypoxic il6-expressing transgenic PH mice, emphasizing the crucial role of NOCT in PH pathogenesis. CONCLUSIONS: Hypoxia-induced ADAR1 deficiency upregulates NOCT expression to induce PAEC interferon signaling activation, PAEC apoptosis, and PH. This study provides impetus to target the ADAR1-NOCT axis for more effective diagnostics and therapeutics for PH.

BACKGROUND: ADAR1 (adenosine deaminase acting on RNA 1) catalyzes the conversion of adenosine to inosine in double stranded RNAs (dsRNAs), which is critical to prevent autoinflammatory responses mediated by activation of the type I IFN (interferon) signaling. We define the role of ADAR1-dependent RNA editing in IFNβ activation in pulmonary arterial smooth muscle cells (PASMCs) from idiopathic pulmonary arterial hypertension (IPAH), a devastating disease leading to right heart failure and death. METHODS: RNA editing levels were analyzed in PASMCs from IPAH patients versus healthy controls. A conditional transgenic mouse model, Adar1 ^{SMC - KO} , was generated by knocking out Adar1 selectively in Sma (smooth muscle actin)–expressing cells, followed by 3 weeks of hypoxic exposure to induce pulmonary hypertension (PH). RESULTS: PASMCs from patients with IPAH displayed decreased levels of ADAR1 mRNA and isoform p150 protein, accompanied by accumulated dsRNA compared with healthy PASMCs. ADAR1 knockdown in PASMCs upregulated MDA5 (melanoma differentiation-associated protein 5), PKR (protein kinase R), IFNβ, and IFN-stimulated genes. Compared with controls in vivo, hypoxic Adar1 ^{SMC -KO} mice developed severe PH, as evidenced by excessive vascular remodeling in distal arterioles and increased endothelium leakage, resulting in elevated right ventricular systolic pressure and right ventricular hypertrophy. Mechanistically, Ifnβ signaling in Adar1 ^SMC-KO induced the recruitment of macrophages, enhancing pulmonary artery muscularization. Pharmacological treatment with Pkr-relevant inhibitor 2BAct decreased Ifnβ and macrophages, thus attenuating pulmonary hypertension (PH) in hypoxic Adar1 ^SMC-KO mice. CONCLUSIONS: Our study describes a fundamental molecular mechanism underlying the progression of PH. We highlight the detrimental role of innate immune responses, where smooth muscle cell and context-specific RNA editing, along with the sensing of dsRNA, mediate disease progression and excessive vascular remodeling. This finding suggests that targeting PKR could be the new therapeutic strategy for treating pulmonary arterial hypertension.

Supplementary Data with figires_tables

HIPPO components mammalian Ste20-like protein kinases 1 and 2 (MST1/2) are well described growth suppressors. However, in pulmonary arterial hypertension (PAH), MST1/2 switch their roles and become pro-proliferative and pro-survival molecules, supporting hyper-proliferation of pulmonary artery (PA) smooth muscle cells (PASMCs) and adventitial fibroblasts (PAAFs), remodeling of small PAs, and pulmonary hypertension. Here, we report that MST1/2 promotes hyper-proliferation and apoptosis resistance of human PAH PASMCs and PAAFs by up-regulating cell division cycle protein 20 (CDC20), establishing novel link between HIPPO-MST1/2 and cell cycle regulation in PAH.

The tumor microenvironment (TME) significantly impacts cancer progression, yet traditional animal models do not fully recapitulate the situation in humans. To address this, we developed tumor-derived precision lung slices (TD-PCLS), an ex vivo platform for studying the lung TME and evaluating therapies. TD-PCLS, viable for 8 to 10 days, preserve the heterogeneity and metabolic activity of primary tumors, as confirmed by seahorse analysis. Using multispectral FACS and phenocycler multiplex imaging, we spatially profiled TME components and cancer cell functionality. Additionally, TD-PCLS revealed patient-specific responses to chemo- and immunotherapies. To complement TD-PCLS, we established tumor-cell-seeded PCLS (TCS-PCLS) by introducing tumor and immune cells into healthy lung slices. This model highlighted macrophage-tumor interactions as critical for tumor cell proliferation, migration, and immune modulation. Together, these platforms provide a robust tool for lung cancer research, enabling precision medicine and advancing therapeutic discovery.

Chronic thromboembolic pulmonary hypertension (CTEPH) leads to progressive right ventricular (RV) dysfunction. Pulmonary endarterectomy (PEA) is an established treatment for these patients; however, the molecular mechanisms underlying RV remodeling and recovery remain poorly understood. Here we show that RNA sequencing and histological analysis of RV free wall and septal biopsies from patients with CTEPH reveal extracellular matrix enrichment and cytoskeletal remodeling before PEA. These changes were consistent across an exploratory and confirmatory cohort. Post-PEA samples showed reversal of both histological and transcriptional abnormalities. Key signaling molecules—ANKRD1, IL7R and SERPINE1—were implicated in fibrotic and proliferative pathways, as confirmed in human tissues and experimental models. Our findings identify a reversible gene expression and structural remodeling signature in the RV, linking hemodynamic unloading with molecular recovery. These insights suggest potential therapeutic targets to modulate maladaptive RV remodeling in CTEPH and improve outcomes beyond surgical intervention.