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Abstract
Increased consumption of ultra-processed foods (UPFs) is a risk factor for metabolic disorders-associated heart failure (HF). Here, we demonstrate that UPF-induced calpain-1 aggravated oxidative stress, thereby increasing high mobility group box 1 (HMGB1)-mediated myocardial inflammation, which contributes to cardiac dysfunction. After illustrating the dysregulated inflammatory pathways in human and murine hearts upon metabolic stress, we revealed an increase in calpain-1 alongside profound oxidative stress and inflammation in the failing myocardium. Mechanistically, in neonatal rat cardiomyocytes (NRCMs) and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), HMGB1 was upregulated by calpain-1 and reactive oxygen species (ROS) upon stress of saturated and trans fatty acids (FA). Consequently, HMGB1 promoted a pro-inflammatory response in macrophages. On the contrary, inhibition of calpain or ROS efficiently repressed HMGB1 in cardiomyocytes. Therapeutically, either recombinant adeno-associated virus 9 (AAV9) delivered inhibitor of calpain-1 or its pharmacological inhibitor attenuated ROS and HMGB1-induced inflammation in the myocardium and mitigated HF in both male and female mice fed with an ultra-processed diet (UPD). Collectively, we have demonstrated the effects of suppressing calpain-1 and oxidative stress on alleviating myocardial inflammation via blockage of HMGB1 and cardiac dysfunction. The results provide a promising therapeutic strategy for preventing or treating HF in metabolic disorders.
Authors
Claire Ross, Sanskruti Ravindra Gare, Nasser H. Alatawi, Oveena Fonseka, Xinyi Chen, Jiayan Zhang, Yihua Han, Andrea Ruiz-Velasco, Riham R.E. Abouleisa, Yingjuan Liu, Xiangjun Zhao, Han Xiao, Bernard Keavney, Gareth J. Howell, Tao Wang, Tamer M.A. Mohamed, Elizabeth J. Cartwright, Wei Liu
Abstract
Mixed hematopoietic chimerism after hematopoietic cell transplantation (HCT) can modulate the immune system and induce tolerance to allogeneic tissues. However, bone marrow conditioning-related toxicities preclude wider adoption of HCT for transplant allotolerance. We sought agents that reduced conditioning intensity, while promoting durable mixed chimerism after HCT across complete major histocompatibility complex (MHC) mismatch in diabetic mice, permitting islet allotransplantation and diabetes reversal. We systematically tested baricitinib (JAK1/2 inhibitor), venetoclax (Bcl2 inhibitor), and αCD47 antibody, agents in current clinical use, and quantified hematopoietic chimerism after HCT. Combined with αCD117 antibody, transient T cell depletion, and just 10 centigray (cGy) total body irradiation (TBI), these agents enabled durable mixed chimerism and matching allo-islet tolerance, to cure diabetes without evidence of GVHD. Thus, we have developed a conditioning regimen to promote allogeneic mixed hematopoietic chimerism and transplanted islet allotolerance that minimizes conditioning radiation and cures diabetes, a significant achievement.
Authors
Stephan A. Ramos, Preksha Bhagchandani, Diego M. Burgos, Xueying Gu, Richard Rodriguez, Nadia Nourin, Martin Neukam, Shiva Pathak, Judith Shizuru, Seung K. Kim
Abstract
Although inflammatory complications are common in preterm infants, the effects of these conditions on neonatal immune development remain poorly defined. We therefore investigated whether severe bronchopulmonary dysplasia (BPD) and systemic infection, two major complications of prematurity, produce distinct immune signatures and change immune composition over time. We performed longitudinal high-dimensional immune profiling of residual whole blood from 38 preterm infants sampled every two weeks, along with 10 term infants at birth. Preterm infants with severe BPD showed a progressive increase in Th17-polarized CD4+ T cells, neutrophils, and Th17-related cytokines compared to age-matched infants with moderate BPD. In contrast, some preterm infants with systemic bacterial or viral infections mounted exceptionally robust CD8+, CD4+, and γδ T cell responses, with oligoclonal expansion, terminal differentiation, and coordinated plasma cytokine shifts that persisted well beyond resolution of infection. These findings demonstrate that different preterm comorbidities imprint the neonatal immune system in divergent ways. Thus, comprehensive and longitudinal immune profiling may not only identify connections between clinical inflammatory complications and underlying immune pathways but also reveal potential targets for intervention.
Authors
Benjamin A. Fensterheim, Michelle L. McKeague, Divij Mathew, Shwetank, Ajinkya Pattekar, Matthew Lee, Zahabia Rangwala, Sean Nasta, Macy C. Kee, Cynthia Clendenin, Zachary Martinez, Caroline Diorio, Allison R. Greenplate, Krithika Lingappan, E. John Wherry
Abstract
Natural killer (NK) cells are pivotal in the early immune response to Plasmodium falciparum infection, yet their functional dynamics and regulation remain incompletely understood. In a longitudinal study of malaria patients in a non-endemic setting, we observed a transient but potent activation of NK cell cytotoxicity during acute malaria, characterized by rapid granzyme B-mediated killing and elevated expression of genes associated with cytotoxicity (PRF1, GZMB, and GZMA). This heightened activity was supported by increased plasma levels of granzymes and proinflammatory cytokines, which enhanced NK cell function in vitro. However, plasma samples from clinical malaria also contained inhibitory mediators, including soluble cytokine receptors, which dampened NK cell responses. These findings reveal that the host microenvironment orchestrates a tightly regulated NK cell response that potentiates cytotoxicity during acute infection and rapidly downmodulate it after treatment. Understanding this balance between activation and suppression may inform strategies to harness NK cells for malaria control while minimizing immunopathology.
Authors
Pengjun Xi, Patrick A. Sandoz, Maximilian Julius Lautenbach, Eleni Bilev, Björn Önfelt, Anna Färnert, Quirin Hammer, Christopher Sundling
Abstract
Sepsis is a leading cause of death for which host-directed therapies are urgently needed. We performed high-dimensional flow cytometry, measurement of soluble biomarkers, and lipopolysaccharide (LPS) stimulation of neutrophils to characterize neutrophil heterogeneity and function in patients with sepsis. We observed that in sepsis patients, low-density neutrophils (LDNs) are elevated and phenotypically diverse populations of innate immune cells with varying degrees of maturity and myeloperoxidase expression. Spleen tyrosine kinase (SYK) expression was found to be higher in whole blood neutrophils and LDNs of sepsis patients compared to healthy donors. Importantly, SYK+LDNs associated with increased levels of intracellular myeloperoxidase (MPO) and soluble biomarkers. Furthermore, SYK+LDNs correlated with clinical outcomes of sepsis disease severity including sequential organ failure assessment (SOFA) score, mechanical ventilation, and vasopressors. Functionally, the SYK inhibitor R406 suppressed changes in neutrophil features of activation from normal-density neutrophils and LDNs including the SYK+ and SYK- neutrophil subsets and MPO release from LDNs following LPS stimulation of sepsis neutrophils. Combined, these results establish LDNs as a heterogenous population of neutrophils that express high levels of SYK and support SYK inhibition as a novel therapeutic target aimed at suppressing overactive neutrophils in sepsis.
Authors
Heather L. Teague, Lauren Knabe, Raquel S. Da Cruz, Xianglan Yao, Kiana C. Allen, Trenton Williams, Cumhur Y. Demirkale, Merte Woldehanna, Ernest Evans, Amir Hobson, Jared D. Wilkinson, Steven D. Nathan, Christopher S. King, Jeffrey R. Strich
Abstract
Hypothalamic melanocortin 4 receptors (MC4Rs) play a central role in regulating food intake and energy homeostasis. In fact, inactivating mutations in the MC4R gene are the most common form of monogenic obesity. Agonist activation of MC4Rs reduces food intake by modulating hypothalamic signaling circuits. Thus, a detailed understanding of the signaling pathways that regulate MC4R activity is of considerable translational relevance. Ligand-activated MC4Rs interact not only with heterotrimeric G proteins but can also recruit beta-arrestin-2 (barr2) to the receptor. The potential functional role of barr2 in regulating the anorectic effects of MC4R signaling remains unexplored. In the present study, we used mutant mouse models to demonstrate that MC4R-mediated activation of barr2/ERK signaling in MC4R neurons of the paraventricular nucleus leads to reduced food intake. We also found that the appetite-suppressing effect of setmelanotide, an MC4R agonist approved by the FDA for the treatment of certain types of obesity, requires the presence of barr2 in MC4R-containing neurons. These data suggest that MC4R agonists able to promote MC4R/barr2 interactions with high efficacy may become useful as appetite-suppressing drugs.
Authors
Misbah Rashid, Lei Wang, Zhenzhong Cui, Oksana Gavrilova, Huiyan Lu, Kozo Kaibuchi, Sarah Zeitlmayr, Thomas Gudermann, Andreas Breit, Jürgen Wess
Abstract
BACKGROUND. IL-7 is a critical cytokine in T cell development, survival, and homeostasis. Previous preclinical and clinical studies reported that IL-7 treatment increased T cell counts, but its effect on peripheral blood T cells in cancer patients and molecular mechanisms have not been explored. METHODS. We investigated effects of long-acting recombinant human interleukin-7 (rhIL-7-hyFc) on peripheral T cells in patients with advanced solid tumors. Peripheral blood samples were collected before and after treatment, followed by analysis through single-cell transcriptomics and flow cytometry. RESULTS. We found that rhIL-7-hyFc induced marked expansion of proliferating T cells, and promoted transcriptional changes associated with immune activation, cell cycle progression, and anti-apoptosis. Trajectory analysis revealed that post-treatment T cells had distinct transcriptional states enriched for cytokine- and TCR-mediated signaling pathways. Notably, a second dose administered after three weeks yielded diminished proliferation and minimal transcriptional changes, which were independent of antidrug antibody or CD127 downmodulation. Examination of elements of the IL-7 signaling pathway revealed intact proximal signaling (e.g., STAT5 phosphorylation) but downregulation of distal elements, including PIM-1 kinase and c-Myc. CONCLUSIONS. Our results demonstrate that rhIL-7-hyFc induces robust peripheral T-cell expansion and activation in patients with solid tumors, supporting its potential use for lymphopenic patients treated with cancer immunotherapy. TRIAL REGISTRATION. NCT03478995, NCT03619239. FUNDING. NRF-2022R1A2C3007292, RS-2024-00439160, RS-2025-02213409, RS-2025-25460003
Authors
Ho Cheol Jang, Jeong Yeon Kim, Sojeong Kim, Heewon Kim, Mi-Sun Byun, Myung Ah Lee, Jong Hee Chang, Do-Hyun Nam, Tae Won Kim, Sin-Soo Jeun, Joohyuk Sohn, Su-Hyung Park, Eui-Cheol Shin
Abstract
Interscapular brown adipose tissue (iBAT), one of the most vascularized tissues in the body, exemplifies the intricate crosstalk between the vascular system and adipocytes. BAT is known to secrete abundant exosomes into circulation, while exosomes are known to play a key role in vascular remodeling and cell migration. However, whether BAT-derived exosomes (BATexos) modulate peripheral vasculature remains unclear. Here, we report that BATexos promoted peripheral angiogenesis and vascular repair. Among their cargo, miR-378a-3p was highly enriched and identified as a key mediator of endothelial angiogenic function. The overexpression of miR-378a-3p in endothelial cells substantially promoted cell migration and tube formation. Conversely, inhibition of exosome secretion from BAT impaired vascular repair and delayed wound healing. Mechanistically, miR-378a-3p directly targeted the phosphatase and tensin homolog (Pten), thereby activating the PI3K-AKT signaling pathway. Liposomes encapsulating miR-378 mimics promoted angiogenesis and accelerated wound healing in a diabetic mouse model. Collectively, this study uncovers BAT-derived miR-378a-3p as a key regulator of vessel regeneration and tissue repair following injury, offering new therapeutic potential for treating vascular complications in metabolic disease.
Authors
Hongyan Deng, Yuyu Xie, Jiadai Liu, Jing Ge, Qianqian Kang, Rui He, Zhihan Wang, Xuemin Peng, Zengzhe Zhu, Wenshe Wang, Yulian Liu, Ronghui Gao, Ruping Pan, Min Yang, Yong Chen
Abstract
BACKGROUND. Disseminated coccidioidomycosis (DCM) is an often fatal and otherwise intractable condition requiring lifelong antifungal treatment. We have previously shown that a deranged polarization of CD4+ T cells toward a Th2 phenotype can exist in the context of DCM. Here we studied a large population of subjects to determine the frequency of abnormal Th2 skewing of CD4+ T cells in patients with coccidioidomycosis and to identify underlying genetic mechanisms supporting this phenotype. METHODS. We collected peripheral blood mononuclear cells from 204 patients with coccidioidomycosis, including 96 patients with disseminated disease. We measured immune phenotypes and cytokine production by CD4+ T cells from patients and healthy controls, and comparisons between groups were made based on disease severity and demographics. Whole genome sequencing was conducted on 180 individuals who also had cytokine profiling. RESULTS. We found that ~25% of DCM patients had a CD4+ T-cell compartment that was abnormally skewed toward a Th2 phenotype, and Th2 skewing was highly correlated with male sex. Co-culture of T cells with the IL4R/IL13R-blocking antibody dupilumab reduced Th2 skewing. Sequencing revealed rare variants in genes involved in the IL-12-IFN-γ axis in several Th2-skewed patients, and we validated one such variant in IFNGR1 as hypomorphic. CONCLUSION. Patients with DCM, especially males, should be screened for Th2 skewing of CD4+ T cells. Patients with Th2 skewing should be additionally screened for genetic defects in the IL-12-IFN-γ axis. Our findings give a mechanistic rationale for blockade of IL4R in Th2-skewed patients with refractory coccidioidomycosis.
Authors
Timothy J. Thauland, Smriti S. Nagarajan, Alexis V. Stephens, Samantha L. Jensen, Anviksha Srivastava, Miguel A. Moreno Lastre, Terrie S. Ahn, Chantana Bun, Michael T. Trump, Royce H. Johnson, George R. Thompson III, Maria I. Garcia-Lloret, Valerie A. Arboleda, Manish J. Butte
Abstract
Background. Coccidioidomycosis ranges from self-limiting Uncomplicated Valley Fever (UVF) in most cases to life-threatening Disseminated Coccidioidomycosis (DCM) in rare individuals. A few patterns of immunologic deficits allowing for dissemination have been identified, though the specific defects in most individuals with DCM remain undefined. We hypothesized that chronic antigen exposure in DCM engenders a state of T cell exhaustion. Methods. From a cohort of over 300 subjects with confirmed diagnoses of coccidioidomycosis, circulating T cell phenotypes were characterized via flow cytometry and Coccidioides-specific T cell responses were measured by Activation-Induced Marker (AIM) assay. Results. Male sex was significantly associated with disseminated disease (odds ratio 2.5; 95% CI: 1.5 – 4.0). 52% of subjects showed Coccidioides-specific T cell responses in our AIM assay. We noted a significant difference in subjects sampled in the first year of diagnosis, where only 8% of DCM subjects had T cell responses during this time, as compared to 44% of UVF subjects (p = 0.04). Among DCM patients with detectable AIM responses, CD4+ T cells demonstrated an exhausted phenotype with elevated PD-1 expression compared to UVF subjects. In vitro PD-1 blockade augmented IFNγ production in most tested DCM subjects. Conclusion. These findings suggest that dissemination may occur in some individuals during a period of impaired antigen-specific T-cell activity. Importantly, these responses can be augmented in vitro by PD-1 blocking antibodies, supporting further study of immune checkpoint therapy as an adjunct to antifungal treatment in disseminated coccidioidomycosis.
Authors
Gregory D. Whitehill, Alexis V. Stephens, Timothy J. Thauland, Miguel A. Moreno Lastre, Matthew M. Tate, Sinem Beyhan, Royce H. Johnson, George R. Thompson III, Maria Garcia-Lloret, Manish J. Butte
Abstract
Inactivating NOTCH1 mutations in head and neck squamous cell carcinoma (HNSCC) were described over a decade ago, suggesting a tumorsuppressor function—unlike its oncogenic role in other tumors. Today, much debate persists regarding a putative oncogenic role in HNSCC as well, with reports that NOTCH1 signaling drives tumor growth and a cancerstemcell (CSC) phenotype. In this work, comprehensive experiments unequivocally demonstrate that NOTCH1 is a tumor suppressor in HNSCC regardless of mutation or activation status and that it reduces CSC frequency. We developed a signature of NOTCH1 activation showing the pathway is associated with very early differentiation, an altered tumor microenvironment, and better prognosis. Clarifying whether NOTCH1 occasionally functions as an oncogenic driver in HNSCC is crucial to prognosis and personalized therapy. The results presented unify the field, reconcile conflicting data, and provide critical insights into the biological and clinical significance of NOTCH1, with broader implications in other squamous carcinomas with NOTCH1 mutations.
Authors
Chenfei Huang, Shhyam Moorthy, Qiuli Li, Kazi M. Ahmed, Kalil Saab, Defeng Deng, Jiping Wang, Xiayu Rao, Jiexin Zhang, Yuanxin Xi, Jing Wang, Zhiyi Liu, Noriaki Tanaka, David A. Wheeler, Eve Shinbrot, Rami Saade, Curtis R. Pickering, Tong-Xin Xie, Adel K. El-Naggar, Abdullah A. Osman, Kunal Rai, Patrick A. Zweidler-McKay, John V. Heymach, Lauren A. Byers, Faye M. Johnson, Vlad C. Sandulache, Jeffrey N. Myers, Pedram Yadollahi, Mitchell J. Frederick
Abstract
Systemic inflammation is now recognized as a key contributor to epilepsy pathophysiology, yet the role of innate immune cells, particularly neutrophils, remains poorly defined in epilepsy. While preclinical studies in rodent models have implicated neutrophils in seizure activity, their phenotype in human epilepsy has not been thoroughly investigated. In this study, we aimed to characterize systemic inflammatory profiles and neutrophil-associated immune signatures in the blood of patients with drug-resistant epilepsy, compared to healthy controls. We identified a systemic low-grade inflammatory profile in patients, characterized by elevated neutrophil-to-lymphocyte ratio, C-reactive protein, pro-inflammatory cytokines (IL-6, CXCL8/IL-8, TNF-α), and activated neutrophils (CXCR4+CD62Llow). Neutrophil phenotyping revealed two distinct immune profiles. Patients with longer disease duration exhibited a more immature systemic signature, characterized by immature neutrophils (CD15⁺CD10⁻), resting neutrophils (CXCR4⁺CD62L⁺), and elevated IL-6 levels. In contrast, patients with higher seizure frequency displayed a more inflammatory profile, marked by increased IL-12 and activated (CXCR4+CD62Llow) and hyperactivated (CXCR4highCD62Llow) neutrophil subsets. Moreover, elevated pre-surgical levels of inflammatory profile TNF-α, IL-6, and hyperactivated CXCR4high CD62Llow neutrophils were associated with seizure recurrence one year after surgery. This pioneering study highlights the heterogeneity of peripheral immune responses in drug-resistant epilepsy and identifies neutrophil-related signatures as promising prognostic biomarkers in this context.
Authors
Coraly Simoës Da Gama, Aurelie Hanin, Gwen Goudard, Veronique Masson, Aurore Besnard, Karim Dorgham, Guy Gorochov, Guillaume Dorothee, Valerio Frazzini, Vincent Navarro, Mélanie Morin-Brureau
Abstract
The physician-scientist career has historically progressed through individual persistence and improvisation, as physician-scientists have navigated the demands of clinical practice combined with biomedical research without a clearly structured path. While this approach has sustained the field for several decades, individual determination is increasingly insufficient in the current climate, given the growing complexity within both clinical and research training, as well as potential disruptions to research funding and health care reimbursement. The 2025 ASCI / AAIM / Burroughs Wellcome Fund Physician-Scientist Pathways Workshop convened national leaders and faculty at all career stages to assess existing structures and envision new and more deliberate approaches. Discussions highlighted the impact of NIH initiatives in supporting early careers, institutional vulnerabilities, and need for intentional investments in physician-scientist careers. Breakout sessions emphasized the importance of dedicated funding for physician-scientist pathways, mentorship, social supports, and national benchmarks for compensation and promotion for this unique career pathway. The physician-scientist career path now stands at a crossroads. Going forward, sustained investment, longer and more flexible funding mechanisms such as the R37 and R35 Maximizing Investigators’ Research Award (MIRA) programs, and transparent standards are required. Federal funding alone cannot ensure the stability of a physician-scientist’s career; therefore, new approaches and commitments from academic health centers, philanthropy, and industry will be essential to ensure the viability of this career. With coordinated, intentional strategic planning, the physician-scientist workforce can thrive and remain a driver of America’s biomedical research future.
Authors
Christopher S. Williams, Emily J. Gallagher, Daniel P. Cook, David Mankoff, Rebecca M. Baron, Christopher Pittenger, Jatin M. Vyas, Don C. Rockey, Patrick J. Hu, Ashley L. Steed, W. Kimryn Rathmell, Jeffrey R. Balser, Nancy J. Brown, John M. Carethers, Jonathan A. Epstein, Keith A. Choate, Peter J. Gruber, Tiffany C. Scharschmidt, Kyu Rhee
Abstract
Malnutrition, gut inflammation, and antibiotic-induced dysbiosis (AID) are well-recognized risk factors for poor clinical outcomes among critically ill patients. We previously showed that commercially available plant-based enteral nutrition (PBEN) preserves a commensal microbiome compared with commonly used artificial enteral nutrition (AEN). In this study, PBEN was superior to AEN in promoting recovery from antibiotic-induced dysbiosis in mice and humans. PBEN effectively mitigated anemia and leukopenia, restored naïve lymphocyte populations, and reduced bone marrow myeloid expansion. Animals randomized to PBEN also exhibited improved responses to infectious challenges following antibiotic exposure. A pilot clinical study validated these findings, demonstrating increased gut commensals, reduced pathogens, and improved leukocyte balance in critically ill children receiving PBEN compared with AEN. Together, these results suggest that PBEN offers a practical dietary approach to mitigate antibiotic-associated complications and potentially improve clinical outcomes among hospitalized patients requiring supplemental nutrition.
Authors
Mona Chatrizeh, Jianmin Tian, Matthew Rogers, Firuz Feturi, Guojun Wu, Brian Firek, Roman Nikonov, Lauren Cass, Alexandra Sheppeck, Lavnish Ojha, Ali Carroll, Matthew Henkel, Justin Azar, Rajesh K. Aneja, Brian Campfield, Dennis Simon, Michael J. Morowitz
Abstract
Heart failure with preserved ejection fraction (HFpEF) is a multifactorial disease that develops in several clinical settings. Despite its complex pathogenesis, evidence indicates a central role for fibrosis in the progression of left ventricular (LV) diastolic dysfunction (LVDD). Through exploratory research into brown adipose tissue (BAT)-derived adipokines (BATokines), we identified a secreted-type pro-fibrotic protein, procollagen C-endopeptidase enhancer-1 (PCPE-1), whose expression increased in BAT with aging. PCPE-1 promotes the cleavage of procollagens and is a critical initiator of fibrillogenesis. This molecule was increased in the plasma of aged mice. In addition to aging, dietary obesity led to an increase in PCPE-1 expression in the LV of mice. Both systemic and BAT-specific PCPE-1 depletion ameliorated LV fibrosis and LVDD in the obese HFpEF model. Our data also showed that age-associated LVDD was ameliorated in the systemic PCPE-1 knockout mouse model fed with a normal chow diet. Conversely, the overexpression of PCPE-1 expression in BAT was shown to lead to aggravation of LV fibrosis and LVDD. Mechanistically, we found reactive oxygen species (ROS)/DNA damage/c-Fos/c-Jun signaling resulted in an increased production of PCPE-1 in brown adipocytes. These results indicate PCPE-1 may represent a druggable target for aging- and obesity-related HFpEF.
Authors
Yung-Ting Hsiao, Yohko Yoshida, Hirotsugu Tsuchimochi, Jingyuan Tang, Tin May Aung, Chun-Han Chang, Agian Jeffilano Barinda, Zhihong Li, Nur Syakirah Binti Othman, Tom Yoshizaki, Yiwei Ling, Shujiro Okuda, Manabu Abe, Seiya Mizuno, Satoru Takahashi, Takayuki Inomata, Hidetaka Kioka, Yasushi Sakata, Daichi Maeda, Yuya Matsue, Takaaki Furihata, Hiroshi Iwata, James T. Pearson, Kinya Otsu, Kenneth Walsh, Akihito Ishigami, Tohru Minamino, Ippei Shimizu
Loss of Tumor-Infiltrating Lymphocytes and Poor Response to Immunotherapy in IDH GOF Mutant Melanoma
Abstract
Recent innovations in melanoma treatment with immune checkpoint blockade (ICB) have improved overall outcomes for patients, however over 50% of patients still develop resistance to treatment. These patients either have intrinsic resistance, and never respond to therapy, or develop acquired resistance months or years into treatment. The mechanisms underlying ICB resistance remain poorly understood. Our data shows that isocitrate dehydrogenase gain of function (IDH GOF) mutant melanoma patients have a worse response to anti-PD1 immunotherapy. IDH mutations have been found to be oncogenic and associated with differential methylation in multiple cancers but are not yet characterized in human melanoma. Here, we investigate the clinical, immune, and transcriptional phenotypes of IDH GOF melanomas through analyses of clinical response, single-cell RNA sequencing, bulk RNA sequencing, and DNA methylation data. Single-cell data analysis shows decreased immune infiltrate and activity in the IDH GOF tumors. Bulk sequencing data demonstrates the association between IDH mutation, immune exclusion, and disruptions in global DNA methylation. The melanoma-derived genomic data presented supports previously described resistance mechanisms of IDH mutation in other cancer types and is the first demonstration of the role of IDH GOF in the human melanoma tumor microenvironment.
Authors
Emma Specht, Lakshmi Pakanati, Meng-Ju Wu, Russell W. Jenkins, Derek N. Effiom, Nabeel Bardeesy, Bradley E. Bernstein, Moshe Sade-Feldman, Christine G. Lian, Genevieve M. Boland, Elena Torlai Triglia, Sonia Cohen
Abstract
X-linked myotubular myopathy (XLMTM) is a rare genetic disorder that typically presents at birth with progressive muscle weakness and respiratory difficulties and is caused by myotubularin-1 (MTM1) gene mutations. Here we examine the role of phosphatidylinositol-4-phosphate 3-kinase catalytic subunit type 2 beta (PIK3C2B), a lipid kinase that interacts with MTM1, in XLMTM in various models. We examined the effect of BLU3797, a novel, highly potent, selective, orally bioavailable PIK3C2B inhibitor, on survival, muscle development, myofiber phenotypes, and gene expression in MTM1-/y mice. PIK3C2B-deficient XLMTM animals demonstrated increased survival, restored muscle function, fewer myofibers with centralized nuclei, and normalization of disease-associated molecular markers. BLU3797 alleviated the XLMTM phenotype in a dose-dependent and reversible manner. Loss of functional PIK3C2B in XLMTM mice promoted a more differentiated, adult-like myofiber profile, which was strongly associated with normalization of disease surrogates and a reduction in markers of early muscle development and regeneration. BLU3797 treatment appears to modulate the expression of microRNAs associated with satellite cell activation and myofiber fusion. These findings indicate that PIK3C2B inhibition with BLU3797 effectively reverses the XLMTM disease phenotype by enhancing muscle function and promoting development toward a more mature state.
Authors
Andrew Shearer, Melissa L. Brooks, Maxine M. Chen, Thiwanka Samarakoon, John Hsieh, Gramoz Kondakci, Emanuele Perola, Jason Brubaker, Kristina Fetalvero, Stefanie Schalm, Joana Caetano-Lopes
Abstract
Cytotoxic chemotherapy primarily targets rapidly proliferating cancer cells but also depletes normal myeloid cells. The resulting cell loss triggers reactive myelopoiesis, a compensatory process in which hematopoietic stem and progenitor cells (HSPCs) in the bone marrow (BM) regenerate myeloid lineages. We previously showed that the alkylating agent cyclophosphamide (CTX) induces myelopoiesis leading to the expansion of immunosuppressive monocytes in mice. However, the molecular features and clinical relevance of these cells remain poorly understood. Here, we report the emergence of immunosuppressive monocytes in the peripheral blood of lymphoma patients receiving CTX-containing chemotherapy. To gain mechanistic insight into CTX-induced myelopoiesis, we performed single-cell RNA sequencing (scRNA-seq) and assay for transposase-accessible chromatin using sequencing (ATAC-seq) on BM monocytes from CTX-treated mice. These analyses revealed a heterogeneous monocyte population and demonstrated that CTX skews myelopoiesis toward the generation of neutrophil-like monocytes (NeuMo). Moreover, CTX-induced NeuMo cells, enriched within the CXCR4⁺CX3CR1⁻ monocyte subset, exhibited potent T-cell suppressive activity. Using the NeuMo gene signature, reanalysis of public scRNA-seq datasets identified a transcriptionally similar monocyte subset in chemotherapy-treated cancer patients. Collectively, our findings suggest that the expansion of NeuMo-like cells following chemotherapy represents a conserved immunoregulatory feedback mechanism with potential impact on tumor response to chemoimmunotherapy.
Authors
Huidong Shi, Zhi-Chun Ding, Ogacheko D. Okoko, Xin Wang, George Zhou, Yan Ye, Md Yeashin Gazi, Caitlin Brandle, Lirong Pei, Rafal Pacholczyk, Catherine C. Hedrick, Locke J. Bryan, Gang Zhou
Abstract
Chronic neuropathic pain is frequently comorbid with anxiety disorders, yet the neural circuits underlying this interaction remain poorly defined. The parafascicular nucleus of the thalamus (PF) integrates nociceptive and affective signals, but its specific regulatory mechanisms in pain-anxiety comorbidity are not well known. Using spared nerve injury (SNI) model mice, we combined viral neural tracing, chemogenetics, pharmacology, and electrophysiology to dissect the locus coeruleus (LC)-PF neural pathway. Viral tracing revealed monosynaptic projections from norepinephrinergic (NEergic) neurons in the dorsal LC to calcium/calmodulin dependent protein kinase IIα (CaMKIIα)- immunopositive neurons within the PF. Chemogenetic inhibition/activation of this pathway were performed in naïve and SNI mice, alongside intra-PF microinjection of the alpha-2 adrenergic receptor (ADRA2) antagonist yohimbine. Behavioral tests assessed mechanical/thermal hypersensitivity and anxiety-like behaviors. Results showed that 92.1% of PF-projecting LC neurons were NEergic, with 70.1% localized dorsally. Chemogenetic inhibition of LCNE-PFCaMKIIα neural pathway significantly alleviated both acute-phase mechanical hypersensitivity (< 7 days post-surgery) and chronic-phase anxiety-like behaviors in SNI mice, while activation of this pathway induced pain sensitization and anxiety-like behaviors in naïve mice. Intra-PF yohimbine reversed SNI-induced allodynia and anxiety-like behaviors. Electrophysiology confirmed yohimbine increased PF neuronal intrinsic excitability. These results suggest that the LCNE-PFCaMKIIα neural pathway promotes neuropathic pain and comorbid anxiety via ADRA2-mediated suppression of PF neuronal activity. Targeted inhibition of this circuit may represent a therapeutic strategy for pain-related affective disorders.
Authors
Zhong-Yi Liu, Fei Li, Li-Ming Liu, Yao-Hua Liu, Jia Li, Zi-Ang Li, Jin Cheng, Tian-Yu Zhao, Hui-Min Tian, Dong-Ning Li, Sha-Sha Tao, Hui Li, Fen-Sheng Huang, Yun-Qing Li
Abstract
Subendothelial retention of cholesterol-rich apolipoprotein-B-containing lipoproteins drives atherosclerotic arterial disease. In peripheral interstitial fluid from patients with type 2 diabetes (T2D), levels of such particles have been shown to be paradoxically reduced relative to those in serum, presumably reflecting their increased retention within the arterial wall. To identify possible mechanisms involved in lipoprotein retention in T2D, we obtained serum and skin blister fluid from such patients and matched controls, together with skin biopsies in a subset of individuals. In T2D, smaller LDL and VLDL remnant particles were more prominent in serum, but not in interstitial fluid, reflecting their enhanced vascular entrapment. The interstitial-fluid-to-serum ratio of apolipoprotein-B was 58% lower in T2D than in controls (0.14 vs 0.33), concomitant with increased susceptibility for LDL binding to proteoglycans. The most marked differences were seen in patients with clinically evident cardiovascular disease. The degree of transvascular retention was positively related to the propensity of isolated serum LDL to bind aortic proteoglycans, both in T2D and in controls. Skin unesterified cholesterol levels were higher in T2D patients relative to healthy controls. With aging, both proteoglycan binding and apparent vascular retention of LDL increased in controls, but not in T2D, indicating that these mechanisms may also be relevant for atherogenesis in non-diabetic individuals.
Authors
Pär Björklund, Jennifer Härdfeldt, Lauri Äikäs, Sara Straniero, Minna Holopainen, Katariina Öörni, Mats J. Rudling, Bo Angelin
