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Abstract
BACKGROUND. Supraventricular tachycardia (SVT) and Wolff-Parkinson-White (WPW) are potentially highly symptomatic and, rarely, lethal arrhythmias associated with atrioventricular accessory pathways. While the etiology of accessory pathways remains largely unknown, they are frequently observed with Ebstein’s Anomaly, a congenital heart disease associated with maternal medicinal lithium use. Therefore, we evaluated whether in utero exposure to lithium from environmental sources is associated with the prevalence of accessory pathways. METHODS. We conducted a county-level ecological comparison of lithium levels in drinking water versus prevalence of WPW diagnoses among patients < 18-years-old in California using multivariable logistic regression. Children were analyzed given their high likelihood to reside in the same county during fetal development. WPW cases were identified using diagnostic codes. Positive and negative controls, including falsification endpoints, were analyzed. RESULTS. Among 2,329,090 patients (mean age 8.2 ± 5.9 years, 47.8% female), 686 (0.03%) were diagnosed with WPW. Areas where lithium levels ≥ 75th percentile were associated with 71% greater odds of WPW (OR 1.71, 95% CI 1.44 to 2.03). Areas above the lithium health-based screening limit had 29% greater odds of WPW (OR 1.29, 95% CI 1.05 to 1.58). Similar results existed in a New York statewide cohort. In validation analyses, areas where lithium levels ≥ 75th percentile were associated with a higher prevalence of SVT, syncope, palpitations, and catheter ablation procedures. CONCLUSIONS. Higher lithium levels in drinking water were associated with a greater prevalence of childhood-diagnosed WPW, implicating a potentially modifiable risk factor for the development of accessory pathways.
Authors
Justin T. Teraoka, Anushree Agarwal, Janet J. Tang, Thomas A. Dewland, Gregory M. Marcus
Abstract
SEC16A encodes a scaffold protein that organizes the endoplasmic reticulum (ER) exit sites, specialized ER subdomains that mediate export of newly synthesized proteins and regulate early secretory pathway steps. The role of SEC16A in human nervous system diseases has not been established yet. Here, we report six individuals with bi-allelic SEC16A variants who presented with early-onset neurological symptoms, including cognitive impairment, motor delays, and seizures. Using Drosophila, we show the Sec16 ortholog is essential for normal development and that its loss causes early lethality. Neuron-specific knockdown of Sec16 causes neurological phenotypes including locomotor defects, seizure-like bang sensitivity, and impaired synaptic transmission, which can be associated with the clinical features observed in affected individuals. Neurons differentiated from patient-derived induced pluripotent stem cells (iPSCs) carrying SEC16A variants display reduced SEC16A protein, impaired neurite outgrowth and increased excitability, which are rescued in isogenic control neurons when the variants are corrected, consistent with a loss-of-function mechanism. Increased ER stress was observed in both patient iPSC-derived neurons and fly models. In summary, our findings indicate a conserved requirement for SEC16A in neurodevelopment and neuronal function and implicate ER stress as a key cellular phenotype underlying the SEC16A-associated neurodevelopmental disorder.
Authors
Mengqi Ma, Xiaowei Lei, Juan Li, Yiming Zheng, Yu Yuan, Yohei Nitta, Xiao Mao, Zhenming Guo, Shenzhao Lu, Mingxi Deng, Xueyang Pan, Oguz Kanca, Shiyi Liu, Hua Wang, Bo Xiao, Rachel Schot, Serwet Demirdas, Yolande van Bever, Marjon van Slegtenhorst, Tahsin Stefan Barakat, Shan Bian, Hugo J. Bellen, Lili Long
Abstract
Triple negaJve breast cancer (TNBC) is characterised by poor prognosis and limited treatment opJons, parJally due to therapy-resistant stem/progenitor cells driving metastasis. Elevated expression of the transcripJon factor MYBL2 is associated with aggressive disease, yet its role in BC stem/progenitor cells remains elusive. Here, we employed inducible MYBL2 downregulaJon in TNBC cell lines and paJent-derived models to invesJgate its funcJon and idenJfy potenJal vulnerabiliJes associated with its high expression. Our funcJonal and mechanisJc analyses reveal that high MYBL2 levels are criJcal for stem cell self-renewal, DNA repair, and replicaJon stress response and lowering MYBL2 impairs stemness and self-renewal both in vitro and in vivo. Accordingly, high-MYBL2 stem/progenitor cells exhibit increased sensiJvity to Polθ inhibitors which is lost upon MYBL2 downregulaJon due to transcripJonal suppression. Combining Polθ inhibitors with ATR inhibitors further enhances this sensiJvity, in vitro, ex vivo and in vivo. These findings suggest that dual Polθ/ATR inhibiJon represents a promising therapeuJc strategy to target TNBC stem/progenitor cells with high MYBL2 expression, highlighJng MYBL2 as a potenJal biomarker to straJfy paJents for Polθ inhibitor-based therapies in TNBC.
Authors
Rachel Bayley, Xiaoping Qu, Adrija Chakraborty, Menna Shamma, Ciara Ward, Kinga Koscielniak, Anna Munsey, Suman Ahmed, Amber Stiby, Bohdana-Myroslava Briantseva, Kirendeep Jawanda, Christopher J. Lord, Abeer M. Shaaban, Marco Saponaro, Graeme C. M. Smith, Robert B. Clarke, Clare Davies, Paloma Garcia
Abstract
The human retina and underlying choroid have multiple well-organized vascular layers. However, retinal and choroidal neovascularization can develop in diseases such as diabetic retinopathy or neovascular age-related macular degeneration, which can result in destructive vision loss. Ocular macrophages are implicated in the pathogenesis of such neovascular diseases. To identify a potential pro-angiogenic macrophage subtype, we integrated 13 single-cell RNA sequencing datasets from human and mouse eyes comprising 173 unique samples. From 99,184 mononuclear phagocytes, we identified a single macrophage subtype with high expression of SPP1, FABP5, and IL7R that was over-represented from neovascular disease samples. We fate mapped these cells and specifically depleted them, showing that they are monocyte-derived and necessary for laser-induced choroidal neovascularization in mice. Finally, we performed a high-resolution spatial RNA sequencing experiment on six human donors and found that the pro-angiogenic macrophage subtype localized to human choroidal neovascular membranes. These macrophages and other cells in neovascular membranes expressed MMP14, a potential therapeutic target, and MMP14 inhibition decreased choroidal neovascularization in mice. Collectively, we show that this Monocyte-derived Pro-angiogenic Ocular Macrophage (MoPOM) subtype is upregulated in multiple ocular neovascular diseases across species, necessary for choroidal neovascularization, and is a potential therapeutic target to reduce destructive angiogenesis in the eye.
Authors
Andrew P. Voigt, Joyce Gong, Steven Droho, Kelly Mulfaul, Amrita Rajesh, Greta E. Forbes, Jacob K. Sterling, Miles J. Flamme-Wiese, Robert F. Mullins, Jeremy A. Lavine
Abstract
Splenic myelopoiesis supplies immunosuppressive myeloid cells in cancer, yet its local regulation remains unclear. Here we identify a self-amplifying circuit between neutrophils and hematopoietic stem and progenitor cells (HSPCs) that sustains splenic myelopoiesis. Tumor-associated neutrophils produced reactive oxygen species (ROS) and created an oxidatively stressed milieu in the spleen, which activated FOXO1 in neighboring HSPCs and drove DRP1-mediated mitochondrial fission, reprogramming HSPCs toward myeloid-biased expansion and immunosuppressive output. Progeny neutrophils reinforced splenic oxidative stress and perpetuated this loop. Genetic ablation of Cybb or spleen-targeted ROS scavenging inhibited FOXO1 activation and preserved fused mitochondria morphology in HSPCs. Consistently, blockade of FOXO1 or DRP1 prevented mitochondrial fission and reduced ROS-producing myeloid cell generation. Such interventions reduced splenic myelopoiesis, curtailed the production of suppressive myeloid cells in the spleen and their infiltration into tumors, and enhanced cytotoxic T cell activity, thereby restoring antitumor immunity and restraining tumor progression. Analyses of spleen samples from cancer patients, together with cord-blood HSPC and neutrophil co-culture experiments, support the human relevance of this neutrophil–ROS–HSPC axis. These findings reveal a self-propagating neutrophil–HSPC feedback circuit that locally sustains tumor-promoting splenic myelopoiesis and provide a rationale for targeting neutrophil-to-progenitor signaling to normalize antitumor immunity.
Authors
Lan Zhu, Shufeng Luo, Qiaomin Hua, Chang-An Zhao, Huiling Lin, Mingyu Liu, Lingyan Zhu, Jiabin Zheng, Huolun Feng, Yong Li, Chong Wu, Limin Zheng
Abstract
BACKGROUND. The penile urethra is a primary site of HIV acquisition in males, although little is known about the urethral determinants of HIV susceptibility. Inflammation at other genital sites enhances HIV risk, and studies suggest that some inflammatory urethral bacteria may be vaginally acquired. Here, we characterize the impact of sexual debut on the microbiome and immune milieu of the penile urethra in adolescent males from Rakai, Uganda. METHODS. A cohort of 185 self-reported sexually naïve adolescent males from Rakai, Uganda were followed longitudinally for 3 years, with questionnaires administered every 3 months and urethral swabs collected annually. Urethral soluble immune factors were quantified by chemiluminescent multiplex immunoassay and bacterial 16S rRNA sequencing was performed. Unsupervised clustering and mixed-effects models were used to assess associations between sexual debut and the urethral microbiome and immune milieu. RESULTS. Unsupervised clustering at 36 months identified two distinct urethral Community State Types (CSTs): CST-1 was dominated by Streptococcus mitis and CST-2 by bacteria associated with bacterial vaginosis (BV), particularly Sneathia amnii and Gardnerella vaginalis. CST-2 was greatly enriched at 36 months compared to baseline and was associated strongly with sexual debut. Individual bacterial taxa enriched in CST-2 were associated with both sexual debut and elevated urethral inflammatory cytokines, independent of serum testosterone and penile circumcision status. CONCLUSION. The penile urethra is colonized by BV-associated bacteria after penile-vaginal sex debut. Their presence in the urethra induces local inflammation and may serve as a reservoir for subsequent reintroduction into the vagina of female sexual partners.
Authors
Rameen Jamil, Sanja Huibner, Ping Yang, James Nnamutete, Jodie L. White, Lori Sokoll, James Pollock, Margaret Nakalanzi, Simon Peter Bukenya, Stephen D. Kiboneka, Mathias Agaba, Mary J. Nalubowa, Aggrey Anok, Godfrey Kigozi, Ronald M. Galiwango, Bryan Coburn, Cindy M. Liu, Jessica L. Prodger, Aaron A.R. Tobian, Rupert Kaul
Abstract
Alcohol-associated liver disease (ALD) is associated with higher incidence of colorectal liver metastasis (CRLM); prohibitin 1 (PHB1) defends against CRLM yet its role in ALD and ALD-CRLM is poorly understood and was investigated here. In human, murine, and in vitro ALD models, cytosolic and nuclear PHB1 were depleted, whereas mitochondrial PHB1 was preserved despite a loss in mitochondrial mass. Nuclear PHB1 loss was driven by CRM1-mediated export, and blocking this interaction with a PHB1 nuclear export signal (NES) peptide retained nuclear PHB1, ameliorating both ALD and ALD-CRLM. PHB1 NES prevented depletion of nuclear methionine adenosyltransferase α1, oxidative stress, and induction of matrix metalloproteinase 7 (MMP-7) and multiple oncogenes. Single-nucleus RNA sequencing of NIAAA diet-fed mouse livers and spatial transcriptomics of ALD-CRLM mice livers revealed that PHB1 NES treatment mitigated alcohol-induced metabolic and oncogenic stress, attenuated pro-inflammation and pro-fibrogenic responses, remodeled immunosuppressive microenvironment and contributed to overall hepatoprotection. These findings identify nuclear PHB1 depletion as a driver and a promising therapeutic target in ALD and ALD-CRLM.
Authors
Jyoti Chhimwal, Sonal Sinha, Jina Kim, Mario Alba, Lucía Barbier-Torres, Jiaohong Wang, Heping Yang, Youngyi Lim, Ramachandran Murali, Maria Lauda Tomasi, Sungyong You, José M. Mato, Shelly C. Lu
Abstract
Type 2 (T2) inflammation is a defining feature of asthma and associated with epithelial dysfunction, including goblet cell metaplasia and ciliary loss. Here, we investigated whether T2 inflammation and associated 15 lipoxygenase-1 (15LO1) activity alters mitochondrial metabolism in airway epithelial cells (AECs) and contributes to disease pathophysiology. Freshly isolated AECs from T2-high asthmatic participants exhibited increased oxygen consumption rates (OCR), including elevated basal respiration and proton leak, alongside reduced coupling efficiency compared to T2-low participants. These functional changes were accompanied by increased expression of electron transport chain (ETC) proteins, worse lung function and epithelial phenotypic changes. In vitro, IL-13 stimulation of differentiated AECs recapitulated these findings, inducing higher OCR, increased ETC protein levels, and enhanced proton leak while paradoxically reducing intracellular ATP. These metabolic alterations are associated with increased uncoupling protein 2 (UCP2) expression and goblet cell differentiation. Mechanistically, 15LO1 emerged as a key regulator, as ALOX15 knockdown or pharmacologic inhibition reduced OCR parameters, ETC protein expression, UCP2, and goblet cell markers, without effect on ATP levels, suggesting additional regulatory mechanisms. Collectively, these findings identify a metabolic axis linking T2 inflammation, mitochondrial dysfunction, and airway epithelial metabolism, while highlighting 15LO1-driven mitochondrial uncoupling as a potential therapeutic target in asthma.
Authors
Xiuxia Zhou, Krithika S. Rao, Sruti Shiva, Catharina van Heusden, Qi Wei, Nobuhiko Fukuda, Mayoko Tsuji, Angelina Kendi, Laura R. Bradley, Jinming Zhao, John B. Trudeau, Anuradha Ray, Richard C. Boucher, Sally E. Wenzel
Abstract
Hypoxia-inducible factor 2α (HIF-2α) is a central oncogenic driver in clear cell renal cell carcinoma (ccRCC) and a therapeutic target of the small-molecule inhibitor belzutifan. Genetic studies in murine models have suggested that hypoxia signaling may support T cell effector programs, raising concern that HIF-2α inhibition could impair antitumor immunity. However, whether pharmacologic HIF-2α inhibition alters human T cell biology remains unknown. Here, we investigated the cell-intrinsic effects of EPAS1 (encoding HIF-2α) perturbation in primary human T cells. CRISPR/Cas9-mediated deletion of HIF-2α demonstrated no notable transcriptional effects. Similarly, pharmacologic treatment with belzutifan produced minimal transcriptional changes and did not impair proliferation, cytokine production, polyfunctionality, or cytotoxic activity in T cells derived from healthy donor peripheral blood, peripheral blood from patients with ccRCC, or tumor-infiltrating lymphocytes under hypoxic conditions. High- dimensional immunophenotyping revealed preserved T cell differentiation and activation states following pharmacologic HIF-2α inhibition in vitro and in peripheral blood from patients receiving HIF-2α inhibitor therapy. Together, these findings demonstrate that pharmacologic HIF-2α inhibition preserves key effector programs, providing a mechanistic basis for the immunologic safety of HIF-2α–targeted therapy in ccRCC.
Authors
Katrine N. Madsen, Soki Kashima, Hanna Soulati, Lena Wirth, Katsuhiro Ito, Zachary A. Yochum, Vivien Moritz, Julia Walker, Marc Machaalani, Fady Ghali, Patrick Kenney, Adebowale Adeniran, Michael Hurwitz, Toni K. Choueiri, David A. Braun
Abstract
During organogenesis, stem cells undergo cellular and metabolic remodelling, facilitated by autophagy-mediated turnover of organelles. Autophagy impairment has been linked to human diseases, including neurodevelopmental disorders associated with disrupted neural stem/precursor cell (NPC) homeostasis, but the underlying mechanisms and pathogenic processes governing these connections remain poorly understood. Here, we report three de novo variants of uncertain significance (p.Gly223Asp, p.Gly889Glu, p.Met978Val) in the deubiquitinase USP15 in human probands with diverse clinical features, including a spectrum of brain malformations and metabolic phenotypes. Proband variants differentially altered USP15 activity and nucleocytoplasmic localization. USP15 showed dynamic localization in NPCs of embryonic mouse cerebral cortex. Using a knock-in mouse model carrying the p.Met978Val variant, we showed that aberrant cytoplasmic accumulation of USP15, but not its loss-of-function, impaired NPC self-renewal and differentiation, leading to reduced neuronal output and enlarged lateral ventricles. Mechanistically, USP15 deubiquitinated autophagy regulator ATG16L1, impeded its normal turnover, and impaired autophagy. Concurrently, lipid droplet mobilization and mitochondrial dynamics were attenuated. Reestablishing the ubiquitination-deubiquitination balance restored autophagy activity and normal neurogenesis. Our findings suggest that nucleocytoplasmic shuttling of USP15 creates a switch-like autophagy signal controlling NPC homeostasis, and its disruption may contribute to the pathogenesis of complex neurodevelopmental conditions.
Authors
Kaylan M.L. Burns, Mashiat Zaman, Daniel Young, Michelle Hua, Yu-Yun Gao, Yvonne Yan Yan Or, Farzaneh Nobakht, Bryn D. Webb, Julie A. Jurgens, Francis Ramond, Xing-Chang Wei, Caroline D. Robson, Alistair T. Pagnamenta, Marvel Megaly, Belal Tafech, Antoine Dufour, Timothy E. Shutt, Ping Yee Billie Au, Guang Yang
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Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)