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A profound medical triumph of the last half of the 20th century was the elucidation of the transport system mediated by plasma lipoproteins. Scientists identified the proteins that carry water-insoluble [...]

Preeclampsia, a hypertensive disorder of pregnancy, poses a serious threat to the health of women and infants, causing over 75,000 maternal deaths and more than 500,000 infant deaths annually worldwide. Its grim toll is compounded by adverse maternal complications, such as seizures (eclampsia), liver dysfunction, or pulmonary edema. Although interventions like antihypertensives and magnesium sulfate offer partial mitigation of risks to the mother, the definitive remedy remains delivery of the infant and placenta. However, this solution begets iatrogenic prematurity, ushering infants into a neonatal period fraught with serious complications, such as bronchopulmonary dysplasia and necrotizing enterocolitis, as well as other long-term consequences. In 1914, James Young proposed that interference with uterine blood supply to the placenta would lead to placental infarctions that, in turn, would release toxins into the maternal circulation, thus causing eclampsia (summarized in ref. 1). Decades later, during the mid-1980s, Roberts and Taylor hypothesized that preeclampsia is a endothelial disease based on the observation that the endothelium was the predominant cell type injured during preeclampsia and because endothelial injury antedated the clinical manifestations of disease (2). In a 2003 JCI paper, our group reported evidence and posited that elevated levels of soluble fms-like tyrosine kinase 1 (sFLT1) secreted from the placenta acted as the putative "endothelial toxin" that drives the clinical syndrome of preeclampsia (3). Below, we [ABSTRACT FROM AUTHOR]

The article offers information on the challenges and advancements in hematopoietic stem cell transplantation (HCT) over the past 50 years, as chronicled through key papers in the JCI. Topics include the curative potential of HCT for various hematologic diseases, the challenges of allogeneic HCT such as relapse and graft-versus-host disease (GVHD), and the immunologic complexities underlying these challenges.

Since 1983, the JCI has consistently published papers that have contributed to much of today's understanding of the immunopathogenesis of HIV-1-host interactions. A representative subset of papers published in the [...]

The ability to change an organism's DNA through gene editing is of great importance for the prevention and treatment of genetic and acquired diseases. Rapid progress has been made during the last decade due to the discovery and refinement of CRISPR/Cas9 as an accurate, fast, and reliable genome editing technique. In this issue of the JCI, Lebek et al. present the culmination from a line of work in the Olson laboratory focused on in vivo gene editing of CAMK2D. The paper presents a combined state-of-the-art gene therapy approach that demonstrates how gene therapy can yield cardioprotection in a mouse model and takes notable steps toward potential applicability in patients. [ABSTRACT FROM AUTHOR]

To the Editor: A recently published JCI paper revealed that cancer-associated fibroblasts (CAFs) are present in glioblastoma and are defined by the presence of 9 transcriptional markers (1). CAFs can [...]

The physiology of lipid droplets (LDs) has been most extensively characterized in adipocytes, but LDs also accumulate in endothelial cells lining blood vessels in response to changing levels of triglycerides. In recent issues of the JCI, two independent papers highlight a direct role of endothelial LDs in the genesis of hypertension and atherosclerosis in rodent models. Kim et al. demonstrated that accumulation of LDs in the endothelium leads to hypertension, impairs endothelial function, and accelerates atherosclerosis. Boutagy, Gamez-Mendez, et al. knocked out Atgl in the endothelium and confirmed triglyceride accumulation in endothelial cells that was associated with reduced NO synthesis and impaired endothelial-dependent vasodilation. These data suggest that enhancing triglyceride breakdown in the endothelium could provide a treatment target for patients with metabolic syndrome., The pathophysiologic impact of excessive fatty acids Lipid droplets (LDs) are intracellular fat reservoirs that store neutral lipids for future use as an important energy source in metabolically active tissues [...]

As part of the JCI's 100th-anniversary celebration, I reflect here on a few of the many papers published in JCI that have advanced our understanding of the physiological and pathological [...]

Uncovering inflammation in adipose tissue The association between obesity and diabetes has been recognized since ancient times; as early as the fifth century BCE, the Indian physician Sushruta linked diabetes [...]

Sarcoidosis is a multiorgan granulomatous disease that lacks diagnostic biomarkers and targeted treatments. Using blood and skin from patients with sarcoid and non-sarcoid skin granulomas, we discovered that skin granulomas from different diseases exhibit unique immune cell recruitment and molecular signatures. Sarcoid skin granulomas were specifically enriched for type 1 innate lymphoid cells (ILC1s) and B cells and exhibited molecular programs associated with formation of mature tertiary lymphoid structures (TLSs), including increased CXCL12/CXCR4 signaling. Lung sarcoidosis granulomas also displayed similar immune cell recruitment. Thus, granuloma formation was not a generic molecular response. In addition to tissue-specific effects, patients with sarcoidosis exhibited an 8-fold increase in circulating ILC1s, which correlated with treatment status. Multiple immune cell types induced CXCL12/CXCR4 signaling in sarcoidosis, including Th1 T cells, macrophages, and ILCs. Mechanistically, CXCR4 inhibition reduced sarcoidosis-activated immune cell migration, and targeting CXCR4 or total ILCs attenuated granuloma formation in a noninfectious mouse model. Taken together, our results show that ILC1s are a tissue and circulating biomarker that distinguishes sarcoidosis from other skin granulomatous diseases. Repurposing existing CXCR4 inhibitors may offer a new targeted treatment for this devastating disease., Introduction Sarcoidosis remains a debilitating, and sometimes fatal, multiorgan inflammatory granulomatous disease that predominately affects the lung and skin. Patients struggle with fatigue, difficulty breathing, and pain in their joints, [...]

Testosterone (T) and 17[beta]-estradiol ([E.sub.2]) are produced in male and female humans and are potent metabolic regulators in both sexes. When [E.sub.2] and T production stops or decreases during aging, metabolic dysfunction develops and promotes degenerative metabolic and vascular disease. Here, we discuss the shared benefits afforded by [E.sub.2] and T for metabolic function human females and males. In females, [E.sub.2] is central to bone and vascular health, subcutaneous adipose tissue distribution, skeletal muscle insulin sensitivity, antiinflammatory immune function, and mitochondrial health. However, T also plays a role in female skeletal, vascular, and metabolic health. In males, T's conversion to [E.sub.2] is fundamental to bone and vascular health, as well as prevention of excess visceral adiposity and the promotion of insulin sensitivity via activation of the estrogen receptors. However, T and its metabolite dihydrotestosterone also prevent excess visceral adiposity and promote skeletal muscle growth and insulin sensitivity via activation of the androgen receptor. In conclusion, T and [E.sub.2] are produced in both sexes at sex-specific concentrations and provide similar and potent metabolic benefits. Optimizing levels of both hormones may be beneficial to protect patients from cardiometabolic disease and frailty during aging, which requires further study., Introduction Testosterone (T) and 17[beta]-estradiol ([E.sub.2]) are considered male and female sex hormones, respectively, because they are secreted by gonads in the circulation at sex-specific concentrations and are involved in [...]

Liraglutide, a glucagon-like peptide-1 (GLP-1) analog, is approved for obesity treatment, but the specific neuronal sites that contribute to its therapeutic effects remain elusive. Here, we show that GLP-1 receptor-positive (GLP-1R-positive) neurons in the lateral septum ([LS.sup.GLP-1R]) play a critical role in mediating the anorectic and weight-loss effects of liraglutide. [LS.sup.GLP-1R] neurons were robustly activated by liraglutide, and chemogenetic activation of these neurons dramatically suppressed feeding. Targeted knockdown of GLP-1 receptors within the LS, but not in the hypothalamus, substantially attenuated liraglutide's ability to inhibit feeding and lower body weight. The activity of [LS.sup.GLP-1R] neurons rapidly decreased during naturalistic feeding episodes, while synaptic inactivation of [LS.sup.GLP-1R] neurons diminished the anorexic effects triggered by liraglutide. Together, these findings offer critical insights into the functional role of [LS.sup.GLP-1R] neurons in the physiological regulation of energy homeostasis and delineate their instrumental role in mediating the pharmacological efficacy of liraglutide., Introduction The obesity pandemic continues to pose a global health threat as safe and effective treatments remain elusive. Among the various pharmacological approaches used, glucagon-like peptide-1 (GLP-1) analogs, including liraglutide, [...]

The microbial unification of the world Unbeknownst to many, we are living during the seventh pandemic of cholera in modern times. Descriptions of a cholera-like illness in India go back [...]

Various organ allografts differ in their propensity to be spontaneously accepted without any immunosuppressive treatment. Understanding the mechanisms behind these differences can aid in managing alloimmune responses in general. C57BL/6 mice naturally accept DBA/2J kidney allografts, forming tertiary lymphoid organs containing regulatory T cells (rTLOs), crucial for graft acceptance. In this issue of the JCI, Yokose and colleagues revealed that rTLOs promote conversion of cytotoxic alloreactive [CD8.sup.*] T cells into exhausted/regulatory ones, through an IFN-[gamma]-mediated mechanism. Their study provides insights into tolerance development that could help promote the acceptance of grafts at higher risk of rejection., Not all transplanted organs are created equal Kidney and liver allografts are capable of actively contributing to the induction and maintenance of immunological tolerance (1, 2), while heart and lung [...]

T cells rewire their metabolic activities to meet the demand of immune responses, but how to coordinate the immune response by metabolic regulators in activated T cells is unknown. Here, we identified autocrine VEGF-B as a metabolic regulator to control lipid synthesis and maintain the integrity of the mitochondrial inner membrane for the survival of activated T cells. Disruption of autocrine VEGF-B signaling in T cells reduced cardiolipin mass, resulting in mitochondrial damage, with increased apoptosis and reduced memory development. The addition of cardiolipin or modulating VEGF-B signaling improved T cell mitochondrial fitness and survival. Autocrine VEGF-B signaling through GA-binding protein [alpha] (GABP[alpha]) induced sentrin/SUMO-specific protease 2 (SENP2) expression, which further de-SUMOylated PPAR[gamma] and enhanced phospholipid synthesis, leading to a cardiolipin increase in activated T cells. These data suggest that autocrine VEGF-B mediates a signal to coordinate lipid synthesis and mitochondrial fitness with T cell activation for survival and immune response. Moreover, autocrine VEGF-B signaling in T cells provides a therapeutic target against infection and tumors as well as an avenue for the treatment of autoimmune diseases., Introduction T cells rewire metabolic activity to meet their own activation demand in response to antigens (1-4). Glucose metabolism in T cells, which increases glucose anabolic metabolism and biomass accumulation [...]

Preventing the onset of autoimmune type 1 diabetes (T1D) is feasible through pharmacological interventions that target molecular stress-responsive mechanisms. Cellular stresses, such as nutrient deficiency, viral infection, or unfolded proteins, trigger the integrated stress response (ISR), which curtails protein synthesis by phosphorylating eukaryotic translation initiation factor-2[alpha] (eIF2[alpha]). In T1D, maladaptive unfolded protein response (UPR) in insulin-producing [beta] cells renders these cells susceptible to autoimmunity. We found that inhibition of the eIF2a kinase PKR-like ER kinase (PERK), a common component of the UPR and ISR, reversed the mRNA translation block in stressed human islets and delayed the onset of diabetes, reduced islet inflammation, and preserved [beta] cell mass in T1D-susceptible mice. Single-cell RNA-Seq of islets from PERK-inhibited mice showed reductions in the UPR and PERK signaling pathways and alterations in antigen-processing and presentation pathways in p cells. Spatial proteomics of islets from these mice showed an increase in the immune checkpoint protein programmed death-ligand 1 (PD-L1) in [beta] cells. Golgi membrane protein 1, whose levels increased following PERK inhibition in human islets and EndoC-[beta]H1 human [beta] cells, interacted with and stabilized PD-L1. Collectively, our studies show that PERK activity enhances [beta] cell immunogenicity and that inhibition of PERK may offer a strategy for preventing or delaying the development of T1D., Introduction Type 1 diabetes (T1D) is a disorder of glucose homeostasis that results from the autoimmune destruction of insulin-producing islet [beta] cells. The importance of the immune system in initiating [...]

Crohn's disease (CD) is marked by recurring intestinal inflammation and tissue injury, often resulting in fibrostenosis and bowel obstruction, necessitating surgical intervention with high recurrence rates. To elucidate the mechanisms underlying fibrostenosis in CD, we analyzed the transcriptome of cells isolated from the transmural ileum of patients with CD, including a trio of lesions from each patient: non-affected, inflamed, and stenotic ileum samples, and compared them with samples from patients without CD. Our computational analysis revealed that profibrotic signals from a subset of monocyte- derived cells expressing CD150 induced a disease-specific fibroblast population, resulting in chronic inflammation and tissue fibrosis. The transcription factor TWIST1 was identified as a key modulator of fibroblast activation and extracellular matrix (ECM) deposition. Genetic and pharmacological inhibition of TWIST1 prevents fibroblast activation, reducing ECM production and collagen deposition. Our findings suggest that the myeloid-stromal axis may offer a promising therapeutic target to prevent fibrostenosis in CD., Introduction Crohn's disease (CD) is a chronic inflammatory condition affecting the gastrointestinal tract, characterized by transmural inflammation that often leads to complications such as strictures, fistulas, and abscesses. The disease [...]

Our study was to characterize sarcopenia in C57BL/6J mice using a clinically relevant definition to investigate the underlying molecular mechanisms. Aged male (23-32 months old) and female (27-28 months old) C57BL/6J mice were classified as non-, probable-, or sarcopenic based on assessments of grip strength, muscle mass, and treadmill running time, using 2 SDs below the mean of their young counterparts as cutoff points. A 9%-22% prevalence of sarcopenia was identified in 23-26 month-old male mice, with more severe age-related declines in muscle function than mass. Females aged 27-28 months showed fewer sarcopenic but more probable cases compared with the males. As sarcopenia progressed, a decrease in muscle contractility and a trend toward lower type IIB fiber size were observed in males. Mitochondrial biogenesis, oxidative capacity, and AMPK-autophagy signaling decreased as sarcopenia progressed in males, with pathways linked to mitochondrial metabolism positively correlated with muscle mass. No age- or sarcopenia-related changes were observed in mitochondrial biogenesis, OXPHOS complexes, AMPK signaling, mitophagy, or atrogenes in females. Our results highlight the different trajectories of age-related declines in muscle mass and function, providing insights into sex-dependent molecular changes associated with sarcopenia progression, which may inform the future development of novel therapeutic interventions., Introduction Sarcopenia, the loss of muscle mass and function due to aging, affects 25%-45% of older adults in the United States (1) and is associated with increased incidence of falls [...]

Alcohol use disorder (AUD) is a prominent contributor to global morbidity and mortality. Its complex etiology involves genetics, epigenetics, and environmental factors. We review progress in understanding the genetics and epigenetics of AUD, summarizing the key findings. Advancements in technology over the decades have elevated research from early candidate gene studies to present-day genome-wide scans, unveiling numerous genetic and epigenetic risk factors for AUD. The latest GWAS on more than one million participants identified more than 100 genetic variants, and the largest epigenome-wide association studies (EWAS) in blood and brain samples have revealed tissue-specific epigenetic changes. Downstream analyses revealed enriched pathways, genetic correlations with other traits, transcriptome-wide association in brain tissues, and drug-gene interactions for AUD. We also discuss limitations and future directions, including increasing the power of GWAS and EWAS studies as well as expanding the diversity of populations included in these analyses. Larger samples, novel technologies, and analytic approaches are essential; these include whole-genome sequencing, multiomics, single-cell sequencing, spatial transcriptomics, deep-learning prediction of variant function, and integrated methods for disease risk prediction., Introduction Alcohol use disorder (AUD) is a chronic relapsing disorder that progresses through a three-stage addiction cycle involving neurocircuitry in the basal ganglia, extended amygdala, and prefrontal cortex (1). Different [...]

Identifying a blood vessel growth factor The discovery of the potent angiogenic factor VEGFA and the subsequent studies that led to the development and successful translation of VEGF inhibitors into [...]

Viral vectors are being used for the treatment of cancer. Yet, their efficacy varies among tumors and their use poses challenges in immunosuppressed patients, underscoring the need for alternatives. We report striking antitumoral effects by a nonlytic viral vector based on attenuated lymphocytic choriomeningitis virus (r3LCMV). We show in multiple tumor models that injection of tumor-bearing mice with this vector results in improved tumor control and survival. Importantly, r3LCMV improved tumor control in immunodeficient [Rag1.sup.-/-] mice and [MyD88.sup.-/-] mice, suggesting that multiple pathways contributed to the antitumoral effects. The antitumoral effects of r3LCMV were also observed when this vector was administered several weeks before tumor challenges, suggesting the induction of trained immunity. Single-cell RNA sequencing analyses, antibody blockade experiments, and knockout models revealed a critical role for host-intrinsic IFN-I in the antitumoral efficacy of r3LCMV vectors. Collectively, these data demonstrate potent antitumoral effects by r3LCMV vectors and unveil multiple mechanisms underlying their antitumoral efficacy., Introduction Cancer is linked to immunosuppression, which inhibits the ability of the immune system to clear tumor cells. A specific challenge in cancer immunotherapies is the presence of 'cold tumors,' [...]

Recently developed antimigraine therapeutics targeting calcitonin gene-related peptide (CGRP) signaling are effective, though their sites of activity remain elusive. Notably, the lymphatic vasculature is responsive to CGRP signaling, but whether meningeal lymphatic vessels (MLVs) contribute to migraine pathophysiology is unknown. Mice with lymphatic vasculature deficient in the CGRP receptor ([Calcrl.sup.iLEC] mice) treated with nitroglycerin-mediated (NTG- mediated) chronic migraine exhibit reduced pain and light avoidance compared with NTG-treated littermate controls. Gene expression profiles of lymphatic endothelial cells (LECs) isolated from the meninges of [Rpl22.sup.HA/+];[Lyve1.sup.Cre] RiboTag mice treated with NTG revealed increased MLV-immune interactions compared with cells from untreated mice. Interestingly, the relative abundance of mucosal vascular addressin cell adhesion molecule 1-interacting (MAdCAMI-interacting) [CD4.sup.+] T cells was increased in the deep cervical lymph nodes of NTG-treated control mice but not in NTG-treated [Calcrl.sup.iLEC] mice. Treatment of cultured hLECs with CGRP peptide in vitro induced vascular endothelial-cadherin (VE-cadherin) rearrangement and reduced functional permeability. Likewise, intra cisterna magna injection of CGRP caused rearrangement of VE-cadherin, decreased MLV uptake of cerebrospinal fluid (CSF), and impaired CSF drainage in control mice but not in [Calcrl.sup.iLEC] mice. Collectively, these findings reveal a previously unrecognized role for lymphatics in chronic migraine, whereby CGRP signaling primes MLV-immune interactions and reduces CSF efflux., Introduction The meninges have traditionally been considered a protective and physical barrier to the brain, shielding the central nervous system from external trauma or systemic insults such as infection and [...]

BACKGROUND. The use of high-throughput technologies has enabled rapid advancement in the knowledge of host immune responses to pathogens. Our objective was to compare the repertoire, protection, and maternal factors associated with human milk antibodies to infectious pathogens in different economic and geographic locations. METHODS. Using multipathogen protein microarrays, 878 milk and 94 paired serum samples collected from 695 women in 5 high and low-to-middle income countries (Bangladesh, Finland, Peru, Pakistan, and the United States) were assessed for specific IgA and IgG antibodies to 1,607 proteins from 30 enteric, respiratory, and bloodborne pathogens. RESULTS. The antibody coverage across enteric and respiratory pathogens was highest in Bangladeshi and Pakistani cohorts and lowest in the U.S. and Finland. While some pathogens induced a dominant IgA response (Campylobacter, Klebsiella, Acinetobacter, Cryptosporidium, and pertussis), others elicited both IgA and IgG antibodies in milk and serum, possibly related to the invasiveness of the infection (Shigella, enteropathogenic E. coli 'EPEC', Streptococcus pneumoniae, Staphylococcus aureus, and Group B Streptococcus). Besides the differences between economic regions and decreases in concentrations over time, human milk IgA and IgG antibody concentrations were lower in mothers with high BMI and higher parity, respectively. In Bangladeshi infants, a higher specific IgA concentration in human milk was associated with delayed time to rotavirus infection, implying protective properties of antirotavirus antibodies, whereas a higher IgA antibody concentration was associated with greater incidence of Campylobacter infection. CONCLUSION. This comprehensive assessment of human milk antibody profiles may be used to guide the development of passive protection strategies against infant morbidity and mortality. FUNDING. Bill and Melinda Gates Foundation grant OPP1172222 (to KMJ); Bill and Melinda Gates Foundation grant OPP1066764 funded the MDIG trial (to DER); University of Rochester CTSI and Environmental Health Sciences Center funded the Rochester Lifestyle study (to RJL); and R01 AI043596 funded PROVIDE (to WAP)., Introduction In 2019, 5.3 million liveborn children died before 5 years of age worldwide, nearly half of whom died from infectious diseases, including lower respiratory infections and diarrhea (1). The [...]

GNAO1 mutated in pediatric encephalopathies encodes the major neuronal G protein G[alpha]o. Of the more than 80 pathogenic mutations, most are single amino acid substitutions spreading across the G[alpha]o sequence. We performed extensive characterization of G[alpha]o mutants, showing abnormal GTP uptake and hydrolysis and deficiencies in binding G[beta][gamma] and RGS19. Plasma membrane localization of G[alpha]o was decreased for a subset of mutations that leads to epilepsy; dominant interactions with GPCRs also emerged for the more severe mutants. Pathogenic mutants massively gained interaction with Ric8A and, surprisingly, Ric8B proteins, relocalizing them from cytoplasm to Golgi. Of these 2 mandatory G[alpha]-subunit chaperones, Ric8A is normally responsible for the G[alpha]i/G[alpha]o, G[alpha]q, and G[alpha]12/G[alpha]13 subfamilies, and Ric8B solely responsible for G[alpha]s/G[alpha]olf. Ric8 mediates the disease dominance when engaging in neomorphic interactions with pathogenic G[alpha]o through imbalance of the neuronal G protein signaling networks. As the strength of G[alpha]o-Ric8B interactions correlates with disease severity, our study further identifies an efficient biomarker and predictor for clinical manifestations in GNAO1 encephalopathies. Our work uncovers the neomorphic molecular mechanism of mutations underlying pediatric encephalopathies and offers insights into other maladies caused by G protein malfunctioning and further genetic diseases., Introduction Heterotrimeric G proteins are the principal transducers of G protein-coupled receptors (GPCRs)--the biggest receptor family in animals--and consist of [alpha], [beta], and [gamma] subunits. Sixteen human G[alpha] subunits fall [...]

Most children with medulloblastoma (MB) achieve remission, but some face very aggressive metastatic tumors. Their dismal outcome highlights the critical need to advance therapeutic approaches that benefit such high-risk patients. Minnelide, a clinically relevant analog of the natural product triptolide, has oncostatic activity in both preclinical and early clinical settings. Despite its efficacy and tolerable toxicity, this compound has not been evaluated in MB. Utilizing a bioinformatic data set that integrates cellular drug response data with gene expression, we predicted that Group 3 (G3) MB, which has a poor 5-year survival, would be sensitive to triptolide/Minnelide. We subsequently showed that both triptolide and Minnelide attenuate the viability of G3 MB cells ex vivo. Transcriptomic analyses identified MYC signaling, a pathologically relevant driver of G3 MB, as a downstream target of this class of drugs. We validated this MYC dependency in G3 MB cells and showed that triptolide exerts its efficacy by reducing both MYC transcription and MYC protein stability. Importantly, Minnelide acted on MYC to reduce tumor growth and leptomeningeal spread, which resulted in improved survival of G3 MB animal models. Moreover, Minnelide improved the efficacy of adjuvant chemotherapy, further highlighting its potential for the treatment of MYC-driven G3 MB., Introduction Nervous system tumors are the leading cause of cancer-related death in children (1), with medulloblastoma (MB) being the most common malignant form (2). Over the last decade, genomic stratification [...]

Leigh syndrome is the most common inherited mitochondrial disease in children and is often fatal within the first few years of life. In 2020, mutations in the gene encoding sulfide:quinone oxidoreductase (SQOR), a mitochondrial protein, were identified as a cause of Leigh syndrome. Here, we report that mice with a mutation in the gene encoding SQOR ([Sqor.sup.[DELTA]N/[DELTA]N] mice), which prevented SQOR from entering mitochondria, had clinical and pathological manifestations of Leigh syndrome. [Sqor.sup.[DELTA]N/[DELTA]N] mice had increased blood lactate levels that were associated with markedly decreased complex IV activity and increased hydrogen sulfide ([H.sub.2]S) levels. Because [H.sub.2]S is produced by both gut microbiota and host tissue, we tested whether metronidazole (a broad-spectrum antibiotic) or a sulfur-restricted diet rescues [Sqor.sup.[DELTA]N/[DELTA]N] mice from developing Leigh syndrome. Daily treatment with metronidazole alleviated increased [H.sub.2]S levels, normalized complex IV activity and blood lactate levels, and prolonged the survival of [Sqor.sup.[DELTA]N/[DELTA]N] mice. Similarly, a sulfur-restricted diet normalized blood lactate levels and inhibited the development of Leigh syndrome. Taken together, these observations suggest that mitochondrial SQOR is essential to prevent systemic accumulation of [H.sub.2]S. Metronidazole administration and a sulfur-restricted diet may be therapeutic approaches to treatment of patients with Leigh syndrome caused by mutations in SQOR., Introduction Leigh syndrome is an inherited metabolic disorder that affects the central nervous system and is the most common mitochondrial disease in children. The genetic abnormalities in Leigh syndrome are [...]

Apoptosis is a form of programmed cell death that is mediated by intrinsic and extrinsic pathways. Dysregulation of and resistance to cell death are hallmarks of cancer. For over three decades, the development of therapies to promote treatment of cancer by inducing various cell death modalities, including apoptosis, has been a main goal of clinical oncology. Apoptosis pathways also interact with other signaling mechanisms, such as the p53 signaling pathway and the integrated stress response (ISR) pathway. In addition to agents directly targeting the intrinsic and extrinsic pathway components, anticancer drugs that target the p53 and ISR signaling pathways are actively being developed. In this Review, we discuss selected and promising anticancer therapies in various stages of development, including drug targets, mechanisms, and resistance to related treatments, focusing especially on B cell lymphoma 2 (BCL-2) inhibitors, TRAIL analogues, DR5 antibodies, and strategies that target p53, mutant p53, and the ISR., Introduction Apoptosis is a form of regulated cell death with a critical role in development and homeostasis (1). Activation of apoptotic pathways results in destruction of target cells with minimal [...]

In the true spirit of probably any MD/PhD student, the second I saw that second pink line emerge on my pregnancy test on an early Saturday morning, I started looking [...]

The discovery that a protein alone could be infectious, proposed by Stanley Prusiner of the University of California San Francisco (UCSF), was considered heretical in 1982. Now considered orthodoxy, at [...]

BACKGROUND. Predicting immune effector cell-associated neurotoxicity syndrome (ICANS) in patients infused with CAR T cells is still a conundrum. This complication, thought to be consequent to CAR T cell activation, arises a few days after infusion, when circulating CAR T cells are scarce and specific CAR T cell- derived biomarkers are lacking. METHODS. [CAR.sup.+] extracellular vesicle ([CAR.sup.+]EV) release was assessed in human CD19.CAR T cells cocultured with [CD19.sup.+] target cells. A prospective cohort of 100 patients with B cell lymphoma infused with approved CD19.CAR T cell products was assessed for plasma [CAR.sup.+]EVs as biomarkers of in vivo CD19.CAR T cell activation. Human induced pluripotent stem cell-derived (iPSC-derived) neural cells were used as a model for [CAR.sup.+]EV-induced neurotoxicity. RESULTS. In vitro release of [CAR.sup.+]EVs occurs within 1 hour after target engagement. Plasma [CAR.sup.+]EVs are detectable 1 hour after infusion. A concentration greater than 132.8 [CAR.sup.+]EVs/[micro]L at hour +1 or greater than 224.5 [CAR.sup.+]EVs/[micro]L at day +1 predicted ICANS in advance of 4 days, with a sensitivity and a specificity outperforming other ICANS predictors. [ENO2.sup.+] nanoparticles were released by iPSC-derived neural cells upon [CAR.sup.+]EV exposure and were increased in plasma of patients with ICANS. CONCLUSION. Plasma [CAR.sup.+]EVs are an immediate signal of CD19.CAR T cell activation, are suitable predictors of neurotoxicity, and may be involved in ICANS pathogenesis. TRIAL REGISTRATION. NCT04892433, NCT05807789. FUNDING. Life Science Hub-Advanced Therapies (financed by Health Ministry as part of the National Plan for Complementary Investments to the National Recovery and Resilience Plan [NRRP]: E.3 Innovative health ecosystem for APC fees and immunomonitoring)., Introduction Anti-CD19 chimeric antigen receptor T (CD19.CAR T) cell therapy changed the treatment of B cell malignancies (1). So far, three CD19.CAR T cell products have received approval from regulatory [...]

Emerging evidence has linked the dysregulation of [N.sup.6]-methyladenosine ([m.sup.6] A) modification to inflammation and inflammatory diseases, but the underlying mechanism still needs investigation. Here, we found that high levels of [m.sup.6]A modification in a variety of hyperinflammatory states are p65-dependent because Wilms tumor 1-associated protein (WTAP), a key component of the 'writer' complex, is transcriptionally regulated by p65, and its overexpression can lead to increased levels of [m.sup.6]A modification. Mechanistically, upregulated WTAP is more prone to phase separation to facilitate the aggregation of the writer complex to nuclear speckles and the deposition of [m.sup.6]A marks on transcriptionally active inflammatory transcripts, thereby accelerating the proinflammatory response. Further, a myeloid deficiency in WTAP attenuates the severity of LPS-induced sepsis and DSS-induced IBD. Thus, the proinflammatory effect of WTAP is a general risk- increasing mechanism, and interrupting the assembly of the [m.sup.6]A writer complex to reduce the global [m.sup.6]A levels by targeting the phase separation of WTAP may be a potential and promising therapeutic strategy for alleviating hyperinflammation., Introduction Inflammation is usually a physiological healing response that is triggered by noxious stimuli and conditions such as infection and tissue injury (1). Moderate inflammation is essential for pathogen clearance, [...]

Copy number variation (CNV) at 7q11.23 causes Williams-Beuren syndrome (WBS) and 7q microduplication syndrome (7Dup), neurodevelopmental disorders (NDDs) featuring intellectual disability accompanied by symmetrically opposite neurocognitive features. Although significant progress has been made in understanding the molecular mechanisms underlying 7q11.23- related pathophysiology, the propagation of CNV dosage across gene expression layers and their interplay remains elusive. Here we uncovered 7q11.23 dosage-dependent symmetrically opposite dynamics in neuronal differentiation and intrinsic excitability. By integrating transcriptomics, translatomics, and proteomics of patient-derived and isogenic induced neurons, we found that genes related to neuronal transmission follow 7q11.23 dosage and are transcriptionally controlled, while translational factors and ribosomal genes are posttranscriptionally buffered. Consistently, we found phosphorylated RPS6 (p-RPS6) downregulated in WBS and upregulated in 7Dup. Surprisingly, p-4EBP was changed in the opposite direction, reflecting dosage- specific changes in total 4EBP levels. This highlights different dosage-sensitive dyregulations of the mTOR pathway as well as distinct roles of p-RPS6 and p-4EBP during neurogenesis. Our work demonstrates the importance of multiscale disease modeling across molecular and functional layers, uncovers the pathophysiological relevance of ribosomal biogenesis in a paradigmatic pair of NDDs, and uncouples the roles of p-RPS6 and p-4EBP as mechanistically actionable relays in NDDs., Introduction With over a thousand associated genes and an increasing number of polygenic risk variants, neurodevelopmental disorders (NDDs), in particular autism spectrum disorder (ASD) and intellectual disability (ID), continue to [...]

Impairment of oligodendrocytes and myelin contributes to neurological disorders including multiple sclerosis (MS), stroke, and Alzheimer's disease. Regeneration of myelin (remyelination) decreases the vulnerability of demyelinated axons, but this repair process commonly fails with disease progression. A contributor to inefficient remyelination is the altered extracellular matrix (ECM) in lesions, which remains to be better defined. We have identified fibulin-2 (FBLN2) as a highly upregulated ECM component in lesions of MS and stroke and in proteome databases of Alzheimer's disease and traumatic brain injury. Focusing on MS, the inhibitory role of FBLN2 was suggested in the experimental autoimmune encephalomyelitis (EAE) model, in which genetic FBLN2 deficiency improved behavioral recovery by promoting the maturation of oligodendrocytes and enhancing remyelination. Mechanistically, when oligodendrocyte progenitors were cultured in differentiation medium, FBLN2 impeded their maturation into oligodendrocytes by engaging the Notch pathway, leading to cell death. Adeno-associated virus deletion of FBLN2 in astrocytes improved oligodendrocyte numbers and functional recovery in EAE and generated new myelin profiles after lysolecithin-induced demyelination. Collectively, our findings implicate FBLN2 as a hitherto unrecognized injuryelevated ECM, and a therapeutic target, that impairs oligodendrocyte maturation and myelin repair., Introduction The importance of oligodendrocytes and myelin in the central nervous system (CNS) is evidenced by the neuronal dysfunction and physical disability observed following their damage (1). Oligodendrocyte loss and [...]

Endothelial cells (ECs) in the descending aorta are exposed to high laminar shear stress, and this supports an antiinflammatory phenotype. High laminar shear stress also induces flow-aligned cell elongation and front-rear polarity, but whether these are required for the antiinflammatory phenotype is unclear. Here, we showed that caveolin-1-rich microdomains polarize to the downstream end of ECs that are exposed to continuous high laminar flow. These microdomains were characterized by high membrane rigidity, filamentous actin (F-actin), and raft-associated lipids. Transient receptor potential vanilloid (TRPV4) ion channels were ubiquitously expressed on the plasma membrane but mediated localized [Ca.sup.2+] entry only at these microdomains where they physically interacted with clustered caveolin-1. These focal [Ca.sup.2+] bursts activated endothelial nitric oxide synthase within the confines of these domains. Importantly, we found that signaling at these domains required both cell body elongation and sustained flow. Finally, TRPV4 signaling at these domains was necessary and sufficient to suppress inflammatory gene expression and exogenous activation of TRPV4 channels ameliorated the inflammatory response to stimuli both in vitro and in vivo. Our work revealed a polarized mechanosensitive signaling hub in arterial ECs that dampened inflammatory gene expression and promoted cell resilience., Introduction Blood flow patterns in the aorta are defined by vessel geometry: the curvature of the aortic arch results in low/oscillatory flow, whereas the straight descending aorta experiences high laminar [...]

Original citation: J Clin Invest. 2017;127(7):2777-2788. https://doi.org/10.1172/JCI92958. Citation for this retraction: J Clin Invest. 2024;134(13):e183295. https://doi.org/10.1172/JCI183295. QIMR Berghofer Medical Research Institute recently notified the JCI of concerns regarding Figure 3C [...]

Original citation: J Clin Invest. 2015;125(11):4053-4062. https://doi.org/10.1172/JCI81187. Citation for this retraction: J Clin Invest. 2024;134(13):e183278. https://doi.org/10.1172/JCI183278. QIMR Berghofer Medical Research Institute recently notified the JCI of concerns regarding Figure 4B [...]

Steatotic donor livers are becoming more and more common in liver transplantation. However, the current use of steatotic grafts is less acceptable than normal grafts due to their higher susceptibility to ischemia/reperfusion (I/R) injury. To investigate the mechanism underlying the susceptibility of steatotic liver to I/R injury, we detected cell death markers and inflammation in clinical donor livers and animal models. We found that caspase-8-mediated hepatic apoptosis is activated in steatotic liver I/R injury. However, ablation of caspase-8 only slightly mitigated steatotic liver I/R injury without affecting inflammation. We further demonstrated that RIPK1 kinase induces both caspase-8-mediated apoptosis and cell deathindependent inflammation. Inhibition of RIPK1 kinase significantly protects against steatotic liver I/R injury by alleviating both hepatic apoptosis and inflammation. Additionally, we found that RIPK1 activation is induced by Z-DNA binding protein 1 (ZBP1) but not the canonical TNF-a pathway during steatotic liver I/R injury. Deletion of ZBP1 substantially decreases the steatotic liver I/R injury. Mechanistically, ZBP1 is amplified by palmitic acid-activated JNK pathway in steatotic livers. Upon I/R injury, excessive reactive oxygen species trigger ZBP1 activation by inducing its aggregation independent of the Z- nucleic acids sensing action in steatotic livers, leading to the kinase activation of RIPK1 and the subsequent aggravation of liver injury. Thus, ZBP1-mediated RIPK1-driven apoptosis and inflammation exacerbate steatotic liver I/R injury, which could be targeted to protect steatotic donor livers during transplantation., Introduction End-stage liver disease is the leading cause of mortality in digestive diseases, with liver transplantation as the sole curative intervention (1). The scarcity of available donor livers has led [...]

Given the global surge in autoimmune diseases, it is critical to evaluate emerging therapeutic interventions. Despite numerous new targeted immunomodulatory therapies, comprehensive approaches to apply and evaluate the effects of these treatments longitudinally are lacking. Here, we leveraged advances in programmable-phage immunoprecipitation methodology to explore the modulation, or lack thereof, of autoantibody profiles, proteome-wide, in both health and disease. Using a custom set of over 730,000 human-derived peptides, we demonstrated that each individual, regardless of disease state, possesses a distinct and complex constellation of autoreactive antibodies. For each individual, the set of resulting autoreactivites constituted a unique immunological fingerprint, or "autoreactome," that was remarkably stable over years. Using the autoreactome as a primary output, we evaluated the relative effectiveness of various immunomodulatory therapies in altering autoantibody repertoires. We found that therapies targeting B cell maturation antigen (BCMA) profoundly altered an individual's autoreactome, while anti-CD19 and anti-CD20 therapies had minimal effects. These data both confirm that the autoreactome comprises autoantibodies secreted by plasma cells and strongly suggest that BCMA or other plasma cell- targeting therapies may be highly effective in treating currently refractory autoantibody-mediated diseases., Introduction Autoantibodies have been identified in a wide range of autoimmune diseases (1-4). In many cases these autoantibodies are directly pathogenic (5-10), while in others they amplify or support T [...]

Healthy adipose tissue is essential for normal physiology. There are 2 broad types of adipose tissue depots: brown adipose tissue (BAT), which contains adipocytes poised to burn energy through thermogenesis, and white adipose tissue (WAT), which contains adipocytes that store lipids. However, within those types of adipose, adipocytes possess depot and cell- specific properties that have important implications. For example, the subcutaneous and visceral WAT confers divergent risk for metabolic disease. Further, within a depot, different adipocytes can have distinct properties; subcutaneous WAT can contain adipocytes with either white or brown-like (beige) adipocyte properties. However, the pathways that regulate and maintain this cell and depot-specificity are incompletely understood. Here, we found that the transcription factor KLF15 is required for maintaining white adipocyte properties selectively within the subcutaneous WAT. We revealed that deletion of Klf15 is sufficient to induce beige adipocyte properties and that KLF15's direct regulation of Adrbl is a critical molecular mechanism for this process. We uncovered that this activity is cell autonomous but has systemic implications in mouse models and is conserved in primary human adipose cells. Our results elucidate a pathway for depot-specific maintenance of white adipocyte properties that could enable the development of therapies for obesity and associated diseases., Introduction Adipocytes are the most prominent cell type in mature adipose tissue and, in addition to being involved in energy homeostasis, these cells receive and produce a variety of potent [...]

This study reports that targeting intrinsically disordered regions of the voltage-gated sodium channel 1.7 ([Na.sub.V]1.7) protein facilitates discovery of sodium channel inhibitory peptide aptamers ([Na.sub.V]iPA) for adeno-associated virus-mediated (AAV-mediated), sensory neuron-specific analgesia. A multipronged inhibition of [I.sub.Na1.7], [I.sub.Na1.6], [I.sub.Na1.3], and [I.sub.Na1.1]--but not [I.sub.Na1.5] and [I.sub.Na1.8]--was found for a prototype and named [Na.sub.V]iPA1, which was derived from the [Na.sub.V]1.7 intracellular loop 1, and is conserved among the TTXs [Na.sub.V] subtypes. [Na.sub.V]iPA1 expression in primary sensory neurons (PSNs) of dorsal root ganglia (DRG) produced significant inhibition of TTXs [I.sub.Na] but not TTXr [I.sub.Na]. DRG injection of AAV6-encoded [Na.sub.V]iPA1 significantly attenuated evoked and spontaneous pain behaviors in both male and female rats with neuropathic pain induced by tibial nerve injury (TNI). Whole-cell current clamp of the PSNs showed that [Na.sub.V]iPA1 expression normalized PSN excitability in TNI rats, suggesting that [Na.sub.V]iPA1 attenuated pain by reversal of injury-induced neuronal hypersensitivity. IHC revealed efficient [Na.sub.V]iPA1 expression restricted in PSNs and their central and peripheral terminals, indicating PSN- restricted AAV biodistribution. Inhibition of sodium channels by [Na.sub.V]iPA1 was replicated in the human iPSC-derived sensory neurons. These results summate that [Na.sub.V]iPA1 is a promising analgesic lead that, combined with AAV-mediated PSN-specific block of multiple TTXs [Na.sub.V]s, has potential as a peripheral nerve-restricted analgesic therapeutic., Introduction Voltage-gated sodium channels ([Na.sub.V]s) are key regulators of neuronal excitability and pain sensations (1). Mammals possess 9 isoforms of [Na.sub.V]s, of which [Na.sub.V]1.7, [Na.sub.V]1.8, and [Na.sub.V]1.9 are preferentially expressed [...]

Carbohydrates and lipids provide the majority of substrates to fuel mitochondrial oxidative phosphorylation. Metabolic inflexibility, defined as an impaired ability to switch between these fuels, is implicated in a number of metabolic diseases. Here, we explore the mechanism by which physical inactivity promotes metabolic inflexibility in skeletal muscle. We developed a mouse model of sedentariness, small mouse cage (SMC), that, unlike other classic models of disuse in mice, faithfully recapitulated metabolic responses that occur in humans. Bioenergetic phenotyping of skeletal muscle mitochondria displayed metabolic inflexibility induced by physical inactivity, demonstrated by a reduction in pyruvate- stimulated respiration ([JO.sub.2]) in the absence of a change in palmitate-stimulated [JO.sub.2]. Pyruvate resistance in these mitochondria was likely driven by a decrease in phosphatidylethanolamine (PE) abundance in the mitochondrial membrane. Reduction in mitochondrial PE by heterozygous deletion of phosphatidylserine decarboxylase (PSD) was sufficient to induce metabolic inflexibility measured at the whole-body level, as well as at the level of skeletal muscle mitochondria. Low mitochondrial PE in C2C12 myotubes was sufficient to increase glucose flux toward lactate. We further implicate that resistance to pyruvate metabolism is due to attenuated mitochondrial entry via mitochondrial pyruvate carrier (MPC). These findings suggest a mechanism by which mitochondrial PE directly regulates MPC activity to modulate metabolic flexibility in mice., Introduction Chronic physical inactivity increases all-cause mortality by 30%, accounting for one death every 44 seconds (1-4). Sedentary behavior exacerbates the risk for many chronic diseases, such as type 2 [...]

BACKGROUND. Early antiretroviral therapy initiation (ARTi) in HIV-1 restricts reservoir size and diversity while preserving immune function, potentially improving opportunities for immunotherapeutic cure strategies. For antibody-based cure approaches, the development of autologous neutralizing antibodies (anAbs) after acute/early ARTi is relevant but is poorly understood. METHODS. We characterized antibody responses in a cohort of 23 participants following ARTi in acute HIV ( RESULTS. Plasma virus sequences at the time of ARTi revealed evidence of escape from anAbs after early, but not acute, ARTi. HIV-1 envelopes representing the transmitted/founder virus(es) (acute ARTi) or escape variants (early ARTi) were tested for sensitivity to longitudinal plasma IgG. After acute ARTi, no anAb responses developed over months to years of suppressive ART. In 2 of the 3 acute ARTi participants who experienced viremia after ARTi, however, anAbs arose shortly thereafter. After early ARTi, anAbs targeting those early variants developed between 12 and 42 weeks of ART and continued to increase in breadth and potency thereafter. CONCLUSION. Results indicate a threshold of virus replication (~60 days) required to induce anAbs, after which they continue to expand on suppressive ART to better target the range of reservoir variants. TRIAL REGISTRATION. ClinicalTrials.gov NCT02656511. FUNDING. NIH grants U01AI169767, R01AI162646, UM1AI164570, UM1AI164560, U19AI096109, K23GM112526, T32AI118684, P30AI045008, P30AI027763, R24AI067039; Gilead Sciences grant INUS2361354; Viiv Healthcare grant A126326., Introduction HIV-1 cure strategies aim to eradicate the proviral reservoir and/ or enhance immune-mediated virus suppression. Thus, understanding HIV-specific cellular and humoral immunity is central to the cure research agenda [...]

Neuroinflammation is a recognized complication of immunotherapeutic approaches such as immune checkpoint inhibitor treatment, chimeric antigen receptor therapy, and graft versus host disease (GVHD) occurring after allogeneic hematopoietic stem cell transplantation. While T cells and inflammatory cytokines play a role in this process, the precise interplay between the adaptive and innate arms of the immune system that propagates inflammation in the central nervous system remains incompletely understood. Using a murine model of GVHD, we demonstrate that type 2 cannabinoid receptor (CB2R) signaling plays a critical role in the pathophysiology of neuroinflammation. In these studies, we identify that CB2R expression on microglial cells induces an activated inflammatory phenotype that potentiates the accumulation of donor-derived proinflammatory T cells, regulates chemokine gene regulatory networks, and promotes neuronal cell death. Pharmacological targeting of this receptor with a brain penetrant CB2R inverse agonist/antagonist selectively reduces neuroinflammation without deleteriously affecting systemic GVHD severity. Thus, these findings delineate a therapeutically targetable neuroinflammatory pathway and have implications for the attenuation of neurotoxicity after GVHD and potentially other T cell-based immunotherapeutic approaches., Introduction Neurological inflammation and cognitive dysfunction are increasingly recognized complications of cancer immunotherapeutic approaches such as immune checkpoint inhibitor treatment (1, 2), chimeric antigen receptor therapy (3, 4), and graft [...]

One critical mechanism through which prostate cancer (PCa) adapts to treatments targeting androgen receptor (AR) signaling is the emergence of ligand-binding domain-truncated and constitutively active AR splice variants, particularly AR-V7. While AR-V7 has been intensively studied, its ability to activate distinct biological functions compared with the full- length AR (AR-FL), and its role in regulating the metastatic progression of castration- resistant PCa (CRPC), remain unclear. Our study found that, under castrated conditions, AR-V7 strongly induced osteoblastic bone lesions, a response not observed with ARFL overexpression. Through combined ChIP-seq, ATAC-seq, and RNA-seq analyses, we demonstrated that AR-V7 uniquely accesses the androgen-responsive elements in compact chromatin regions, activating a distinct transcription program. This program was highly enriched for genes involved in epithelial-mesenchymal transition and metastasis. Notably, we discovered that SOX9, a critical metastasis driver gene, was a direct target and downstream effector of AR-V7. Its protein expression was dramatically upregulated in AR-V7-induced bone lesions. Moreover, we found that Ser81 phosphorylation enhanced AR-V7's pro-metastasis function by selectively altering its specific transcription program. Blocking this phosphorylation with CDK9 inhibitors impaired the AR-V7-mediated metastasis program. Overall, our study has provided molecular insights into the role of AR splice variants in driving the metastatic progression of CRPC., Introduction The androgen receptor (AR) is critical in driving prostate cancer (PCa) development, with androgen deprivation therapy (ADT) being the standard treatment for PCa patients. Although initial responses are generally [...]

Individuals with clonal hematopoiesis of indeterminate potential (CHIP) are at increased risk of aging related health conditions and all-cause mortality, but whether CHIP affects risk of infection is much less clear. Using UK Biobank data, we revealed a positive association between CHIP and incident pneumonia in 438,421 individuals. We show that inflammation enhanced pneumonia risk, as CHIP carriers with a hypomorphic IL6 receptor polymorphism were protected. To better characterize the pathways of susceptibility, we challenged hematopoietic Tet Methylcytosine Dioxygenase 2-knockout ([Tet2.sup.-/-]) and floxed control mice ([Tet2.sup.fl/fl]) with Streptococcus pneumoniae. As with human CHIP carriers, [Tet2.sup.-/-] mice had hematopoietic abnormalities resulting in the expansion of inflammatory monocytes and neutrophils in peripheral blood. Yet, these cells were insufficient in defending against S. pneumoniae and resulted in increased pathology, impaired bacterial clearance, and higher mortality in [Tet2.sup.-/-] mice. We delineated the transcriptional landscape of [Tet2.sup.-/-] neutrophils and found that, while inflammation-related pathways were upregulated in [Tet2.sup.-/-] neutrophils, migration and motility pathways were compromised. Using live-imaging techniques, we demonstrated impairments in motility, pathogen uptake, and neutrophil extracellular trap (NET) formation by [Tet2.sup.-/-] neutrophils. Collectively, we show that CHIP is a risk factor for bacterial pneumonia related to innate immune impairments., Introduction Human aging is accompanied by dysregulation of hematopoiesis in the bone marrow (BM), which may have adverse clinical consequences (1). Hematopoiesis is a tightly regulated process by which hematopoietic [...]

Deepali Gupta, Avi W. Burstein, Dana C. Schwalbe, Kripa Shankar, Salil Varshney, Omprakash Singh, Subhojit Paul, Sean B. Ogden, Sherri Osborne-Lawrence, Nathan P. Metzger, Corine P. Richard, John N. Campbell, [...]

The mammalian SUMO-targeted E3 ubiquitin ligase Rnf4 has been reported to act as a regulator of DNA repair, but the importance of RNF4 as a tumor suppressor has not been tested. Using a conditional-knockout mouse model, we deleted Rnf4 in the B cell lineage to test the importance of RNF4 for growth of somatic cells. Although Rnf4-conditional-knockout B cells exhibited substantial genomic instability, Rnf4 deletion caused no increase in tumor susceptibility. In contrast, Rnf4 deletion extended the healthy lifespan of mice expressing an oncogenic c-myc transgene. Rnf4 activity is essential for normal DNA replication, and in its absence, there was a failure in ATR-CHK1 signaling of replication stress. Factors that normally mediate replication fork stability, including members of the Fanconi anemia gene family and the helicases PIF1 and RECQL5, showed reduced accumulation at replication forks in the absence of RNF4. RNF4 deficiency also resulted in an accumulation of hyper-SUMOylated proteins in chromatin, including members of the SMC5/6 complex, which contributes to replication failure by a mechanism dependent on RAD51. These findings indicate that RNF4, which shows increased expression in multiple human tumor types, is a potential target for anticancer therapy, especially in tumors expressing c-myc., Introduction Healthy cell growth requires posttranslational modification of proteins by addition of ubiquitin or the small ubiquitin-like modifier (SUMO) (1, 2). Ubiquitination and SUMOylation regulate almost every aspect of cellular [...]

Despite widespread utilization of immunotherapy, treating immune-cold tumors remains a challenge. Multiomic analyses and experimental validation identified the OTUD4/CD73 proteolytic axis as a promising target in treating immune-suppressive triple negative breast cancer (TNBC). Mechanistically, deubiquitylation of CD73 by OTUD4 counteracted its ubiquitylation by TRIM21, resulting in CD73 stabilization inhibiting tumor immune responses. We further demonstrated the importance of TGF-[beta] signaling for orchestrating the OTUD4/CD73 proteolytic axis within tumor cells. Spatial transcriptomics profiling discovered spatially resolved features of interacting malignant and immune cells pertaining to expression levels of OTUD4 and CD73. In addition, ST80, a newly developed inhibitor, specifically disrupted proteolytic interaction between CD73 and OTUD4, leading to reinvigoration of cytotoxic [CD8.sup.+] T cell activities. In preclinical models of TNBC, ST80 treatment sensitized refractory tumors to anti-PD-LI therapy. Collectively, our findings uncover what we believe to be a novel strategy for targeting the immunosuppressive OTUD4/CD73 proteolytic axis in treating immune-suppressive breast cancers with the inhibitor ST80., Introduction Despite the widespread utilization of immunotherapy, the poor clinical response by immune-suppressive tumors is an emerging challenge in use of current immune checkpoint inhibitors. Triple negative breast cancers (TNBCs) [...]

Lactylation has been recently identified as a new type of posttranslational modification occurring widely on lysine residues of both histone and nonhistone proteins. The acetyltransferase p300 is thought to mediate protein lactylation, yet the cellular concentration of the proposed lactyl-donor, lactyl-coenzyme A, is about 1,000 times lower than that of acetyl-CoA, raising the question of whether p300 is a genuine lactyltransferase. Here, we report that alanyl-tRNA synthetase 1 (AARS1) moonlights as a bona fide lactyltransferase that directly uses lactate and ATP to catalyze protein lactylation. Among the candidate substrates, we focused on the Hippo pathway, which has a well-established role in tumorigenesis. Specifically, AARS1 was found to sense intracellular lactate and translocate into the nucleus to lactylate and activate the YAP-TEAD complex; and AARS1 itself was identified as a Hippo target gene that forms a positive-feedback loop with YAP-TEAD to promote gastric cancer (GC) cell proliferation. Consistently, the expression of AARS1 was found to be upregulated in GC, and elevated AARS1 expression was found to be associated with poor prognosis for patients with GC. Collectively, this work found AARS1 with lactyltransferase activity in vitro and in vivo and revealed how the metabolite lactate is translated into a signal of cell proliferation., Introduction Lactate is a well-known metabolite found in almost all types of cells, and is highly abundant in proliferating tumor cells owing to the Warburg effect (1, 2). Despite many [...]