Abstract Introduction Ovarian cancer (OvCa) remains the most lethal gynecologic malignancy, with older women experiencing the poorest outcomes. Aging profoundly remodels the ovarian tumor immune microenvironment (TME), promoting regulatory T cell (Treg) mediated immune evasion; however, the underlying metabolic mechanisms remain unclear. Methods Using young (3-month) and aged (22-month) female mice injected intraperitoneally with ID8p53⁻/⁻ OvCa cells, we investigated how age associated metabolic reprogramming influences tumor immunity Results Aged OvCa bearing mice exhibited accelerated tumor progression, reduced survival (median 54 vs. 72 days), decreased CD4+ and CD8+ T cells, and an expanded Treg population. Metabolomic profiling revealed increased succinate accumulation in ascites, tumor tissue, and serum of aged mice and elderly OvCa patients. Exogenous succinate enhanced CCR4+FOXP3+ Treg frequency and upregulated IL-10 and TGF-β secretion. Elevated levels of CCL22, a CCR4 ligand, were also detected in ascites from aged mice and patients, suggesting a chemokine-driven reinforcement of Treg recruitment. PBMCs from aged patients displayed an OXPHOS-reprogrammed CCR4+FOXP3+ Treg subset with heightened suppressive capacity, markedly inhibiting CD4+ and CD8+ effector cytotoxicity. Treatment with AA6, an α-ketoglutarate dehydrogenase inhibitor that blocks succinate synthesis, reduced CCR4+FOXP3+ Treg accumulation, restored effector T-cell function, and significantly prolonged survival in aged OvCa-bearing mice. Conclusion Together, these findings reveal a novel succinate—CCR4 metabolic—chemokine axis that drives Treg mediated immunosuppression in aged OvCa. Targeting this pathway offers a promising strategy to restore anti-tumor immunity and overcome age-related immunotherapy resistance in ovarian cancer. Funding Source N/A Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)
Abstract Fri086: CD38 NADase Suppresses Sulfite Oxidase (SUOX) and Activates Reverse Complex V to Promote Metabolic Remodeling in Endothelial Cells (ECs) Under Disturbed Flow
Arteriosclerosis, Thrombosis, and Vascular Biology | July 28, 2026 | Volume: 46 | Issue: Suppl_1 | Pages: No page available
Introduction: Atherosclerotic lesions preferentially form in arterial regions exposed to disturbed flow (DF), where ECs exhibit mitochondrial (mt) dysfunction, metabolic reprogramming, and senescence. Hippo pathway kinases LATS1/2 maintain EC homeostasis, but how DF–mediated LATS1/2 suppression drives EC metabolic remodeling remains unclear. Hypothesis: We propose that DF activates CD38, leading to mt dysfunction and metabolic reprogramming that promotes EC senescence and aberrant proliferation by LATS1/2 inhibition. Methods: EC-specific Lats1/2 knockout mice were generated using tamoxifen-inducible Cre systems, and DF was induced by partial carotid ligation. Murine and human plaques were analyzed using COMET™ immunofluorescence, and spatial metabolomics. Bioenergetic profiling included Seahorse XF analysis, 13 C-glucose/ 13 C-glutamine tracing, and pharmacologic modulation of CD38, mtROS, and ATP synthase. Results: Complete Lats1/2 deletion caused fatal edema and vascular leakage, while partial loss produced fragile, highly neovascularized plaques. Spatial proteomics revealed a CD38-driven senescence-associated stemness (SAS) phenotype under LATS1/2 deficiency. Metabolomics showed sulfite and taurine accumulation, consistent with SUOX deficiency. Mechanistically, CD38 suppressed SUOX, induced Complex V reverse-mode , increased succinate flux, and accelerated ATP consumption. Despite ATP depletion, glutamate metabolism and TCA cycle flux were enhanced, sustaining EC proliferation under energetic stress. LATS1/2 knockdown reduced mt respiratory capacity (lower OCR peak) without significantly increasing glycolysis, and DF suppressed both OCR and ECAR, indicating impaired energy metabolism under pathological shear stress. CD38 inhibition restored mt respiration and glycolytic capacity by preserving NAD, and rescuing LATS1/2 and DF-mediated defects. Blocking reverse-mode Complex V reduced DF- and LATS1/2-dependent EC senescence and proliferation. Conclusion: Complete LATS1/2 deletion causes fatal vascular leakage, while partial loss drives plaque formation with fragile neovessels through a CD38-dependent SAS phenotype. CD38 suppresses SUOX, induces Complex V reverse-mode , increases succinate flux, and accelerates ATP consumption, enabling EC proliferation despite energy stress. DF and LATS1/2 loss impair mt and glycolytic function, whereas CD38 inhibition restores mt respiration and reduces EC senescence and proliferation to prevent atherothrombosis in DF regions.
GLUT9b- and ABCG2-mediated collecting duct urate transport uncovers a vasopressin-independent mechanism of renal water reabsorption
Journal of Clinical Investigation | June 16, 2026 | Volume: 136 | Issue: 14 | Pages: No page available
Renal water reabsorption is classically regulated by vasopressin V2 receptor (V2R) signaling through cyclic AMP and protein kinase A, driving apical accumulation of aquaporin-2 (AQP2). However, collecting duct water handling is also modulated by vasopressin-independent mechanisms. Here, we examined intracellular soluble urate as a vasopressin-independent regulator of AQP2 trafficking. Intracellular urate accumulation in collecting duct cells was mediated by enhanced apical urate uptake via GLUT9b and reduced apical urate efflux through ABCG2, triggering phosphodiesterase-4 activation, reduced cAMP, and downstream AMP-activated protein kinase (AMPK) activation. The resulting AQP2 accumulation at the apical membrane was independent of V2R signaling, required ongoing endocytosis, and was associated with features of postendocytic apical trafficking of internalized AQP2. In vivo ABCG2 inhibition with probenecid increased apical AQP2 abundance and markedly attenuated tolvaptan-induced polyuria in both wild-type and Pkd1 RC/RC autosomal dominant polycystic kidney disease (ADPKD) mice in a uricase-independent manner while preserving tolvaptan’s ADPKD-modifying efficacy. In a phase II trial with tolvaptan-treated patients with ADPKD, probenecid reduced urine volume and nocturia frequency. Together, these findings support a vasopressin-independent urate/AMPK/AQP2 pathway that regulates renal water handling and, in a preclinical ADPKD model, can uncouple cyst growth attenuation from the dose-limiting aquaretic effects of V2R antagonism.
LATS1/2-CD38 Metabolic Rewiring Links Senescence to Intraplaque Thrombosis
Circulation Research | May 27, 2026 | Volume: 139 | Issue: 2 | Pages: No page available
BACKGROUND: Atherothrombosis, which underlies most acute coronary syndromes and is driven by intraplaque thrombosis, preferentially occurs in regions of disturbed blood flow (d-flow). Although LATS1/2 (large tumor suppressor kinases 1 and 2) are known regulators of endothelial mechanotransduction, the mechanisms by which d-flow connects endothelial senescence, proliferation, and intraplaque thrombosis remain poorly understood. METHODS: We investigated endothelial cell (EC)-specific roles of Lats1/2 using inducible EC-specific knockout mice in a partial carotid ligation model. Spatial multiomics of human and mouse plaques was performed using imaging mass cytometry, COMET sequential immunofluorescence, and spatial metabolomics. RESULTS: Tamoxifen-induced deletion of both Lats1 and Lats2 (homozygous) in ECs caused fatal edema and increased vascular permeability. In contrast, Lats1 het ( ± ) / Lats2 homo ( −/−) -EC-specific knockout mice survived and developed spontaneous atherothrombotic plaques with neovascularization. Spatial proteomics revealed that LATS1/2 loss induced a senescence-associated stemness phenotype driven by CD38 upregulation. Spatial metabolomics showed sulfite and taurine accumulation, indicating SUOX (sulfite oxidase) deficiency. CD38 suppressed SUOX, demonstrated a switch into the reverse mode of mitochondrial complex V, increased succinate dehydrogenase activity, and promoted ATP consumption. Despite ATP depletion, glutamate metabolism and the citric acid cycle flux increased, sustaining EC proliferation under energetic stress. This senescence-associated stemness state promoted both proliferation and senescence, leading to fragile, leaky neovessels and intraplaque thrombotic lesions. Pharmacological CD38 inhibition attenuated these phenotypes. Similar EC states were observed in human plaques. CONCLUSIONS: Loss of Lats1/2 in ECs induces a CD38-associated senescence-associated stemness-like phenotype that promotes intraplaque thrombosis through mitochondrial metabolic reprogramming, including changes consistent with reverse-mode operation of mitochondrial complex V. These findings define a mechanistic link between disturbed flow, endothelial metabolic reprogramming, and intraplaque thrombosis and hemorrhage.
Biological markers of aging across the menopause transition: current evidence
Menopause | May 5, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available
Importance and Objective: Aging is a complex biological process uniquely shaped in women by hormonal transitions, particularly across the menopause transition. While chronological age alone fails to capture individual health variability, emerging molecular biomarkers offer tools to quantify biological aging and understand mechanisms underlying age-related decline. This review synthesizes the current landscape of aging biomarkers, including senescence-associated secretory phenotype factors, epigenetic clocks, clonal hematopoiesis of indeterminate potential, and telomere length, with a particular emphasis on their relevance to menopause. Methods: This narrative review synthesizes human studies, translational research, and foundational basic science identified through PubMed searches through June 2025, examining aging biomarkers in general populations, among women in the menopause transition, and in relation to vasomotor symptoms and hormone therapy. Discussion and Conclusion: Evidence demonstrates that changes in biological aging biomarkers are observed across multiple molecular systems during midlife, including the menopause transition, reflecting broader age-related biological remodeling. Postmenopausal status, particularly following early or surgical menopause, has been associated with biological aging phenotypes, including elevated senescence-associated secretory phenotype factors, epigenetic age acceleration, clonal hematopoiesis, and shorter leukocyte telomere length, likely reflecting a combination of chronological aging, hormonal changes, and individual biological vulnerability. While severe vasomotor symptoms have been linked to higher epigenetic age, hormone therapy may favorably influence certain senescence markers and biological age discrepancy. Despite these advances, significant limitations constrain clinical translation, as current biomarkers capture overlapping biological processes and lack validated thresholds to define biological aging, especially in women. Future research requires large, longitudinal studies across diverse populations to establish clinically meaningful thresholds and sex-specific calibration. Advancing precision health strategies for women requires a better understanding of how reproductive and hormonal factors modify biomarker trajectories to improve risk prediction and to facilitate the development of targeted interventions for age-related diseases.
Aging‐Driven Immunosuppression: The Role of Tregs in the Ovarian Tumor Microenvironment
Aging Cell | April 25, 2026 | Volume: 25 | Issue: 5 | Pages: No page available
ABSTRACT Epithelial ovarian cancer (EOC) incidence and mortality increase with age, driven in part by chronic inflammation, diminished T cell output, and heightened regulatory T cell (Treg) mediated immunosuppression. In aged EOC‐bearing mice, we observed reduced survival, accompanied by impaired CD4 + and CD8 + T cell responses and a marked expansion of FOXP3 + Tregs exhibiting elevated IL‐10 and TGFβ expression. Metabolic profiling revealed enhanced oxidative phosphorylation in Tregs from aged mice, along with a fivefold increase in intracellular succinate levels. This accumulation of succinate within the aged tumor microenvironment was found to potentiate Treg suppressive function. Notably, pharmacologic inhibition of α‐ketoglutarate dehydrogenase reversed this effect, restoring effector T cell activity. These findings highlight succinate‐driven metabolic reprogramming as a central mechanism of age‐related Treg dysfunction in EOC and suggest that targeting succinate metabolism may offer a promising strategy to rejuvenate antitumor immunity in elderly patients.
Regulating the regulators via targeting CD38 in the tumor microenvironment
Frontiers in Immunology | February 3, 2026 | Volume: 17 | Issue: No issue available | Pages: No page available
The immunosuppressive tumor microenvironment (TME) remains a major barrier to effective cancer immunotherapy. Among the central regulators of immune suppression, CD38, a multifunctional ectoenzyme and surface glycoprotein, has emerged as a pivotal orchestrator. CD38 is abundantly expressed on regulatory T cells (Tregs), regulatory B cells (Bregs), myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), and tumor-associated neutrophils (TANs), where it enhances survival, metabolic fitness, and suppressive activity. Invariant natural killer T (iNKT) cells, which can either promote or suppress antitumor immunity, also express CD38 upon activation, suggesting a role for CD38 in directing their context-dependent fate within the TME. Mechanistically, CD38 regulates immune suppression through NAD + hydrolysis, calcium signaling, and promotion of fatty acid oxidation (FAO) while impairing effector T-cell glycolysis and mitochondrial fitness under chronic hypoxia—conditions that favor exhaustion rather than enhanced cytotoxicity. By depleting extracellular NAD + , CD38 diminishes glycolysis and mitochondrial oxidative phosphorylation in effector T cells, while sustaining regulatory cell persistence through FAO. Its enzymatic products, cyclic ADP-ribose (cADPR) and NAADP, further mobilize calcium fluxes that reinforce suppressive function. CD38 also integrates with hypoxia-driven pathways; in CD38 + Bregs, stabilization of HIF-1α and induction of FAO-related genes such as CPT1A and PPARα/γ promote angiogenesis, immune-evasion, and therapeutic resistance. Therapeutically, targeting CD38 with monoclonal-antibodies, small-molecule inhibitors, or combinations with checkpoint blockade and macrophage-reprogramming agents has shown promise. Such interventions reverse immune suppression, restore effector T cell activity, and enhance tumor responsiveness to immunotherapy. In summary, CD38 functions as both a metabolic regulator and an immunologic checkpoint, coordinating suppressive networks and shaping iNKT cell fate. These multifaceted roles position CD38 as a transformative target for next-generation immunotherapies.
Emerging Therapies in Autosomal Dominant Polycystic Kidney Disease
Autosomal dominant polycystic kidney disease is the most common inherited kidney disorder and a leading monogenic cause of kidney failure. Reduction or loss of polycystin-1 and polycystin-2 function disrupts ciliary calcium signaling, elevates cyclic AMP (cAMP), reprograms cellular metabolism, and activates proliferative cascades that drive cyst expansion. Tolvaptan, a vasopressin V2 receptor antagonist, established cAMP modulation as a disease-modifying strategy but is limited by aquaretic effects and hepatotoxicity risk. This review highlights emerging therapeutic strategies in clinical trial development that extend beyond vasopressin antagonism. Gene-directed therapies aim to restore polycystin dosage, including anti–miR-17 oligonucleotides ( e.g ., farabursen) and pharmacochaperones that rescue misfolded polycystin-1 and restore trafficking in select PKD1 missense variants ( e.g ., VX-407). Paracrine signaling can be modulated with anti–pregnancy-associated plasma protein A antibodies that reduce insulin-like growth factor-1 bioavailability in cystic microenvironments. Metabolic reprogramming is targeted by agents such as metformin, bempedoic acid, glucagon-like peptide-1 receptor agonists, and structured dietary interventions. Sodium-glucose cotransporter 2 inhibitors hold theoretical promise but await definitive results from ongoing trials. A novel cAMP-lowering strategy through phosphodiesterase-4 activation is advancing toward clinical testing. Looking ahead, gene therapy, and genome editing offer the potential to raise polycystin levels above the threshold for cystogenesis, although challenges in vector capacity, kidney-specific delivery, and durability remain. Artificial intelligence–guided discovery, coupled with human organoid platforms, is accelerating therapeutic repurposing and rational combination design. Collectively, these advances signal a transition toward a layered, mechanism-guided framework in which vasopressin blockade is integrated with metabolic, other signaling, and genotype-specific therapies. As biomarkers and risk stratification tools mature, autosomal dominant polycystic kidney disease management is poised to become increasingly precise, tolerable, and effective.
Downregulation of LATS1/2 Drives Endothelial Senescence-Associated Stemness (SAS) and Atherothrombotic Lesion Formation
No container title available | June 22, 2025 | Volume: No volume available | Issue: No issue available | Pages: No page available
ABSTRACT Background Atherothrombosis, the main event leading to acute coronary syndrome (ACS), is strongly linked to disturbed blood flow (d-flow) regions. Although the involvement of the Hippo pathway and its kinases Large Tumor Suppressor Kinase 1and 2 (LATS 1 and 2) in mechanical stress responses is known, the mechanisms by which d-flow simultaneously induces senescence, proliferation, and atherothrombosis remain unclear. Methods The role of endothelial cells (EC)-specific LATS1/2 was examined using EC specific knock-out (EKO) mice in a partial left carotid ligation (PLCL) model. Plaque spatial multi-omics analysis was performed by integrating imaging mass cytometry, sequential immunofluorescence (COMET™), and spatial metabolomics at the single-cell level in human and mouse atherosclerotic plaques. Results In tamoxifen-inducible Lats1 homo( -/- ) / Lats2 homo( -/- ) EC-specific knockout (EKO) mice, deletion of LATS1/2 induced by tamoxifen led to fatal outcomes, characterized by severe systemic edema and markedly increased vascular permeability. In contrast, Lats1 het(+ /- ) / Lats2 homo( -/- ) -EKO mice survived and developed atherothrombotic plaques exhibiting neovascularization even without further additional dietary or genetic intervention. Spatial proteomics analysis revealed that LATS1/2 depletion in ECs triggered a senescence-associated stemness (SAS) phenotype, primarily driven by CD38 upregulation. Complementary spatial metabolomics profiling demonstrated a significant increase in sulfite and taurine within LATS1/2-deficient plaques, indicating lowered sulfite oxidase (SUOX) activity. Mechanistically, CD38 upregulation was found to suppress SUOX expression, induce the reverse mode of mitochondrial complex V, and increase succinate dehydrogenase (SDH) activity along with ATP consumption. Paradoxically, despite ATP depletion, this metabolic disturbance enhanced glutamate metabolism and the tricarboxylic acid (TCA) cycle, sustaining EC proliferation under energetically stressed conditions. The combined effect of LATS1/2 deletion and CD38 activation established a unique EC phenotype defined by increased SAS, leading to proliferation, senescence, and eventual cell death. These pathological processes culminated in the formation of atherothrombotic plaques, which were attenuated by inhibition of CD38. Notably, a similar phenotype—marked by metabolically active ECs—was observed in human atherothrombotic plaques, suggesting translational relevance. Conclusion Loss of LATS1/2 in ECs induces SAS state that promotes excessive EC proliferation, senescent cell accumulation, and the development of structurally fragile, leaky neo vessels—hallmarks of atherothrombotic lesions. CD38-mediated SUOX deficiency further amplifies this pathological process by inducing mitochondrial dysfunction, depleting ATP, and triggering compensatory upregulation of glutamate and TCA cycle metabolism. These findings identify a novel LATS1/2–CD38–SUOX axis in ECs that orchestrates SAS-driven atherothrombosis. Targeting CD38 may represent a promising therapeutic strategy to mitigate vascular dysfunction and plaque instability in high-risk ACS patients. Graphical abstract Under normal physiological conditions, LATS1/2 and Lamin A work together to suppress CD38 expression. Lamin A binds directly to the CD38 promoter to repress transcription, and LATS1/2 interact with Lamin A to reinforce this suppression. This collaboration helps maintain low CD38 activity and preserves cellular NAD⁺ levels. However, under disturbed flow (d-flow), both LATS1/2 and Lamin A are downregulated. The loss of this dual repression leads to increased CD38 NADase expression. Elevated CD38 accelerates NAD⁺ consumption, causing NAD⁺ depletion—a hallmark of cellular senescence. Reduced NAD⁺ disrupts key metabolic and stress-response pathways, contributing to the onset of the senescent state. At the same time, CD38 suppresses sulfite oxidase (SUOX), leading to sulfite accumulation and mitochondrial redox imbalance. This shift activates the reverse mode of mitochondrial Complex V, which decreases ATP production and increases mitochondrial ROS, intensifying metabolic and oxidative stress in endothelial cells (ECs). In response, ECs compensate by upregulating succinate dehydrogenase (SDH), enhancing TCA cycle activity and glutamate metabolism. This metabolic adaptation provides the biosynthetic building blocks needed for cell growth and proliferation. As a result, ECs adopt a paradoxical phenotype: they show classical features of stress-induced senescence (such as NAD⁺ depletion, oxidative stress, and cell cycle arrest signals), while simultaneously undergoing metabolic activation and proliferation, also mediated by YAP. This defines a non-canonical endothelial program known as senescence-associated stemness (SAS), characterized by the formation of abnormal, proliferative, yet fragile neovessels. These dysfunctional vessels contribute to atherothrombosis, setting this process apart from the more stable lesions typical of conventional atherosclerosis.
Chronic Cellular
NAD
Depletion Activates a Viral Infection‐Like Interferon Response Through Mitochondrial
DNA
Leakage
Aging Cell | June 16, 2025 | Volume: 24 | Issue: 9 | Pages: No page available
ABSTRACT Nicotinamide adenine dinucleotide (NAD) is a key coenzyme involved in energy metabolism, DNA repair, and cellular signaling. While the effects of acute NAD depletion have been better characterized, the consequences of chronic NAD deficiency remain unclear. Here, we investigated the impact of chronic NAD depletion in cultured cells by removing the availability of nicotinamide (NAM), a key precursor for NAD synthesis, from the culture media. In NIH3T3 fibroblasts, NAM depletion caused a dramatic drop in intracellular NAD levels within 2 days. Remarkably, the cells remained viable even after 7–14 days of NAM depletion, despite NAD + levels falling to less than 10% of control conditions. This chronic NAD depletion led to distinct metabolic alterations. Mitochondrial basal respiration remained unchanged, but cells exhibited reduced spare respiratory and maximal capacities, along with significantly impaired glycolysis. Notably, NAD depletion triggered an interferon‐dependent inflammatory response, resembling viral infections. This was driven by cytosolic leakage of mitochondrial DNA (mtDNA) through voltage‐dependent anion channel 1 (VDAC1), which activated the cGAS‐STING signaling pathway. Inhibition of VDAC oligomerization with VBIT‐4, STING signaling with H‐151, or mtDNA depletion blocked the upregulation of interferon genes induced by NAM depletion. Similar interferon responses triggered by NAD depletion were observed in IMR90 human fibroblasts and HS5 stromal cells. Our findings reveal a novel link between chronic NAD deficiency, VDAC‐mediated mtDNA release to the cytoplasm, and the activation of the inflammatory response, providing new insight into how NAD decline affects cellular metabolic and inflammatory processes.