Issue published May 1, 2023 Previous issue | Next issue
On the cover: Altered gut microbiome in multiple sclerosis
Ma, Sannino, and Linden et al. report that Clostridium perfringens producing epsilon toxin occur in high abundance within the gut microbiome in people with multiple sclerosis and that epsilon toxin is sufficient to induce inflammatory demyelination in susceptible mice. Image credit: 2023 Audra Geras Biomedical Art/Geras Healthcare Productions.
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Commentaries
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Abstract
Out-of-hospital cardiac arrest is associated with a dismal mortality rate and low long-term survival. A large pharmacological knowledge gap exists in identifying drugs that preserve neurological function and increase long-term survival after cardiac arrest. In this issue of the JCI, Li, Zhu, and colleagues report on their engineering of a 20–amino acid cell-permeable peptide (TAT-PHLPP9c) that antagonized the phosphatase PHLPP1 and prevented PHLPP1-mediated dephosphorylation and AKT inactivation. TAT-PHLPP9c administration maintained activated AKT after arrest and led to AKT-mediated beneficial effects on the heart, brain, and metabolism, resulting in increased cardiac output and cerebral blood flow and rescue of ATP levels in affected tissues. TAT-PHLPP9c improved neurological outcomes and increased survival after cardiac arrest in murine and porcine models of cardiac arrest. These findings provide proof of concept that pharmacological targeting of PHLPP1 may be a promising approach to augmenting long-term survival after cardiac arrest.
Authors
Arjun Deb
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The role of the vasculature in inflammatory skin disorders is an exciting area of investigation. Vascular endothelial cells (ECs) play instrumental roles in maintaining the vascular barrier and control of blood flow. Furthermore, ECs contribute to a variety of immune responses, such as targeting immune cells to specific areas of vascular damage, infection, or foreign material. However, mechanisms through which ECs participate in immune-mediated responses remain to be fully explored. In this issue of the JCI, Li, Shao, et al. report on vascular endothelial glycocalyx destruction and the mechanisms through which EC dysfunction contributes to the well-characterized immune-mediated features of psoriasis, a chronic inflammatory skin disease. Here, we discuss the implications of these findings and highlight some risks and benefits of existing therapies designed to target immune cell trafficking in a variety of inflammatory conditions.
Authors
Kelly Z. Young, Olesya Plazyo, Johann E. Gudjonsson
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Fibrinogen-like protein 1 (FGL1) has been associated with improved survival in hepatocellular carcinoma (HCC). However, recent evidence suggests that FGL1 may bind to surface receptors on lymphocytes and induce immune senescence. In this issue of the JCI, Lin and co-authors show that FGL1 may be acetylated by aspirin and targeted for degradation, which is associated with increased antitumor immunity and improved survival. Similar findings were obtained with inhibitors of sirtuin 2 (SIRT2), a histone deacetylase. These findings expand our current understanding of the role of FGL1 in cancer and provide an impetus for the evaluation of alternative immunotherapy combinations in HCC.
Authors
Eric A. Goethe, Amy B. Heimberger, Ganesh Rao
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The proximal tubule is the high-capacity reabsorptive powerhouse of the kidney. Two papers in recent issues of the JCI highlight mechanisms of more delicate effects of the proximal tubule. Yoon et al. demonstrated the intracellular mechanism by which parathyroid hormone (PTH) increases production of 1,25-vitamin D. Activation of PTH receptor 1/cAMP/PKA signaling inhibited salt-inducible kinase 2 (SIK2) and SIK3, which increased CYB27B1 transcription and 1,25-vitamin D production. Replication of these effects with small-molecule SIK inhibitors suggests possible therapeutic applications for patients with disorders characterized by 1,25-vitamin D deficiency. Zhou et al. discovered that proximal tubule glycolysis acts as a phosphate sensor that regulates fibroblast growth factor 23 production in bone. They described several kidney-specific metabolic modifications that enabled glycolysis to be deployed as a phosphate sensor. The provocative results raise intriguing questions with implications for patients with disorders of phosphate homeostasis, including chronic kidney disease.
Authors
Michaela A.A. Fuchs, Myles Wolf
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Multiple sclerosis (MS) is an inflammatory disease of the CNS. In this issue of the JCI, Ma and Sannino et al. show that two strains of intestinal Clostridium perfringens, known to produce epsilon toxin (ETX), were frequently found in patients with MS. Tiny amounts of this toxin added to immunization with myelin antigens provoked MS-like brain lesions in mice. The distribution of these lesions was diffuse, as in MS, in contrast to the spinal cord–restricted lesions of most animal models. ETX bound to endothelial cells of the CNS to enhance immune cell trafficking through the blood-brain barrier into inflammatory brain lessons. ETX also binds to human, but not murine, white blood cells, perhaps altering immune responses. Barrier disruption and changes in immunity due to the toxin could alter the benefits of immune-modulatory MS therapies and are likely to interact with the complex genetics and environmental influences seen in MS.
Authors
Anthony T. Reder
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Research Articles
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Abstract
Cutaneous skeletal hypophosphatemia syndrome (CSHS) is a mosaic RASopathy characterized by the association of dysplastic skeletal lesions, congenital skin nevi of epidermal and/or melanocytic origin, and FGF23-mediated hypophosphatemia. The primary physiological source of circulating FGF23 is bone cells. However, several reports have suggested skin lesions as the source of excess FGF23 in CSHS. Consequently, without convincing evidence of efficacy, many patients with CSHS have undergone painful removal of cutaneous lesions in an effort to normalize blood phosphate levels. This study aims to elucidate whether the source of FGF23 excess in CSHS is RAS mutation–bearing bone or skin lesions. Toward this end, we analyzed the expression and activity of Fgf23 in two mouse models expressing similar HRAS/Hras activating mutations in a mosaic-like fashion in either bone or epidermal tissue. We found that HRAS hyperactivity in bone, not skin, caused excess of bioactive intact FGF23, hypophosphatemia, and osteomalacia. Our findings support RAS-mutated dysplastic bone as the primary source of physiologically active FGF23 excess in patients with CSHS. This evidence informs the care of patients with CSHS, arguing against the practice of nevi removal to decrease circulating, physiologically active FGF23.
Authors
Diana Ovejero, Zachary Michel, Christophe Cataisson, Amanda Saikali, Rebeca Galisteo, Stuart H. Yuspa, Michael T. Collins, Luis F. de Castro
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CRISPR/Cas9 has been proposed as a treatment for genetically inherited skin disorders. Here we report that CRISPR transfection activates STING-dependent antiviral responses in keratinocytes, resulting in heightened endogenous interferon (IFN) responses through induction of IFN-κ, leading to decreased plasmid stability secondary to induction of the cytidine deaminase gene APOBEC3G. Notably, CRISPR-generated KO keratinocytes had permanent suppression of IFN-κ and IFN-stimulated gene (ISG) expression, secondary to hypermethylation of the IFNK promoter region by the DNA methyltransferase DNMT3B. JAK inhibition via baricitinib prior to CRISPR transfection increased transfection efficiency, prevented IFNK promoter hypermethylation, and restored normal IFN-κ activity and ISG responses. This work shows that CRISPR-mediated gene correction alters antiviral responses in keratinocytes, has implications for future gene therapies for inherited skin diseases using CRISPR technology, and suggests pharmacologic JAK inhibition as a tool for facilitating and attenuating inadvertent selection effects in CRISPR/Cas9 therapeutic approaches.
Authors
Mrinal K. Sarkar, Ranjitha Uppala, Chang Zeng, Allison C. Billi, Lam C. Tsoi, Austin Kidder, Xianying Xing, Bethany E. Perez White, Shuai Shao, Olesya Plazyo, Sirisha Sirobhushanam, Enze Xing, Yanyun Jiang, Katherine A. Gallagher, John J. Voorhees, J. Michelle Kahlenberg, Johann E. Gudjonsson
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Dysfunction of vascular endothelial cells (ECs) facilitates imbalanced immune responses and tissue hyperinflammation. However, the heterogeneous functions of skin ECs and their underlying mechanism in dermatoses remain to be determined. Here, focusing on the pathogenic role of skin ECs in psoriasis, we characterized the molecular and functional heterogeneity of skin ECs from healthy individuals and psoriasis patients at the single-cell level. We found that endothelial glycocalyx destruction, a major feature of EC dysfunction in psoriasis, was a driving force during the process of T cell extravasation. Interestingly, we identified a skin EC subset, IGFBP7hi ECs, in psoriasis. This subset actively responded to psoriatic-related cytokine signaling, secreted IGFBP7, damaged the endothelial glycocalyx, exposed the adhesion molecules underneath, and prepared the endothelium for immune-cell adhesion and transmigration, thus aggravating skin inflammation. More importantly, we provided evidence in a psoriasis-like mouse model that anti-IGFBP7 treatment showed promising therapeutic effects for restoring the endothelial glycocalyx and alleviating skin inflammation. Taken together, our results depict the distinct functions of EC clusters in healthy and psoriatic skin, identify IGFBP7hi ECs as an active subset modulating vascular function and cutaneous inflammation, and indicate that targeting IGFBP7 is a potential therapeutic strategy in psoriasis.
Authors
Qingyang Li, Shuai Shao, Zhenlai Zhu, Jiaoling Chen, Junfeng Hao, Yaxing Bai, Bing Li, Erle Dang, Gang Wang
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Antitumor activity of CD8+ T cells is potentially restrained by a variety of negative regulatory pathways that are triggered in the tumor microenvironment, yet, the exact mechanisms remain incompletely defined. Here, we report that intrinsic RIG-I in CD8+ T cells represents such a factor, as evidenced by observations that the tumor-restricting effect of endogenous or adoptively transferred CD8+ T cells was enhanced by intrinsic Rig-I deficiency or inhibition, with the increased accumulation, survival, and cytotoxicity of tumor-infiltrating CD8+ T cells. Mechanistically, T cell activation–induced RIG-I upregulation restrained STAT5 activation via competitive sequestering of HSP90. In accordance with this, the frequency of RIG-I+ tumor-infiltrating CD8+ T cells in human colon cancer positively correlated with attenuated survival and effector signatures of CD8+ T cells as well as poor prognosis. Collectively, these results implicate RIG-I as a potentially druggable factor for improving CD8+ T cell–based tumor immunotherapy.
Authors
Xinyi Jiang, Jian Lin, Chengfang Shangguan, Xiaoyao Wang, Bin Xiang, Juan Chen, Hezhou Guo, Wu Zhang, Jun Zhang, Yan Shi, Jiang Zhu, Hui Yang
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Inflammation promotes adverse ventricular remodeling, a common antecedent of heart failure. Here, we set out to determine how inflammatory cells affect cardiomyocytes in the remodeling heart. Pathogenic cardiac macrophages induced an IFN response in cardiomyocytes, characterized by upregulation of the ubiquitin-like protein IFN-stimulated gene 15 (ISG15), which posttranslationally modifies its targets through a process termed ISGylation. Cardiac ISG15 is controlled by type I IFN signaling, and ISG15 or ISGylation is upregulated in mice with transverse aortic constriction or infused with angiotensin II; rats with uninephrectomy and DOCA-salt, or pulmonary artery banding; cardiomyocytes exposed to IFNs or CD4+ T cell–conditioned medium; and ventricular tissue of humans with nonischemic cardiomyopathy. By nanoscale liquid chromatography–tandem mass spectrometry, we identified the myofibrillar protein filamin-C as an ISGylation target. ISG15 deficiency preserved cardiac function in mice with transverse aortic constriction and led to improved recovery of mouse hearts ex vivo. Metabolomics revealed that ISG15 regulates cardiac amino acid metabolism, whereas ISG15 deficiency prevented misfolded filamin-C accumulation and induced cardiomyocyte autophagy. In sum, ISG15 upregulation is a feature of pathological ventricular remodeling, and protein ISGylation is an inflammation-induced posttranslational modification that may contribute to heart failure development by altering cardiomyocyte protein turnover.
Authors
Veera Ganesh Yerra, Sri Nagarjun Batchu, Harmandeep Kaur, MD Golam Kabir, Youan Liu, Suzanne L. Advani, Duc Tin Tran, Shadi Sadeghian, Phelopater Sedrak, Filio Billia, Uros Kuzmanov, Anthony O. Gramolini, Deema O. Qasrawi, Evgeniy V. Petrotchenko, Christoph H. Borchers, Kim A. Connelly, Andrew Advani
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Aurora A plays a critical role in G2/M transition and mitosis, making it an attractive target for cancer treatment. Aurora A inhibitors showed remarkable antitumor effects in preclinical studies, but unsatisfactory outcomes in clinical trials have greatly limited their development. In this study, the Aurora A inhibitor alisertib upregulated programmed death ligand 1 (PD-L1) expression in a panel of tumor cells both in vitro and in vivo. Upregulation of the checkpoint protein PD-L1 reduced antitumor immunity in immune-competent mice, paradoxically inhibiting the antitumor effects of alisertib. Mechanistically, Aurora A directly bound to and phosphorylated cyclic GMP-AMP synthase (cGAS), suppressing PD-L1 expression in tumor cells. Aurora A inhibition by alisertib activated the cGAS/stimulator of IFN genes (STING)/NF-κB pathway and promoted PD-L1 expression. Combining alisertib with anti–PD-L1 antibody improved antitumor immunity and enhanced the antitumor effects of alisertib in immune-competent mice. Our results, which reveal the immunomodulatory functions of Aurora A inhibitors and provide a plausible explanation for the poor clinical outcomes with their use, offer a potential approach to improve the antitumor efficacy of these inhibitors.
Authors
Xiaobo Wang, Jing Huang, Fenglin Liu, Qian Yu, Ruina Wang, Jiaqi Wang, Zewen Zhu, Juan Yu, Jun Hou, Joong Sup Shim, Wei Jiang, Zengxia Li, Yuanyuan Zhang, Yongjun Dang
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During the development of heart failure (HF), the capacity for cardiomyocyte (CM) fatty acid oxidation (FAO) and ATP production is progressively diminished, contributing to pathologic cardiac hypertrophy and contractile dysfunction. Receptor-interacting protein 140 (RIP140, encoded by Nrip1) has been shown to function as a transcriptional corepressor of oxidative metabolism. We found that mice with striated muscle deficiency of RIP140 (strNrip1–/–) exhibited increased expression of a broad array of genes involved in mitochondrial energy metabolism and contractile function in heart and skeletal muscle. strNrip1–/– mice were resistant to the development of pressure overload–induced cardiac hypertrophy, and CM-specific RIP140-deficient (csNrip1–/–) mice were protected against the development of HF caused by pressure overload combined with myocardial infarction. Genomic enhancers activated by RIP140 deficiency in CMs were enriched in binding motifs for transcriptional regulators of mitochondrial function (estrogen-related receptor) and cardiac contractile proteins (myocyte enhancer factor 2). Consistent with a role in the control of cardiac fatty acid oxidation, loss of RIP140 in heart resulted in augmented triacylglyceride turnover and fatty acid utilization. We conclude that RIP140 functions as a suppressor of a transcriptional regulatory network that controls cardiac fuel metabolism and contractile function, representing a potential therapeutic target for the treatment of HF.
Authors
Tsunehisa Yamamoto, Santosh K. Maurya, Elizabeth Pruzinsky, Kirill Batmanov, Yang Xiao, Sarah M. Sulon, Tomoya Sakamoto, Yang Wang, Ling Lai, Kendra S. McDaid, Swapnil V. Shewale, Teresa C. Leone, Timothy R. Koves, Deborah M. Muoio, Pieterjan Dierickx, Mitchell A. Lazar, E. Douglas Lewandowski, Daniel P. Kelly
×Abstract
Multiple sclerosis (MS) is a complex disease of the CNS thought to require an environmental trigger. Gut dysbiosis is common in MS, but specific causative species are unknown. To address this knowledge gap, we used sensitive and quantitative PCR detection to show that people with MS were more likely to harbor and show a greater abundance of epsilon toxin–producing (ETX-producing) strains of C. perfringens within their gut microbiomes compared with individuals who are healthy controls (HCs). Isolates derived from patients with MS produced functional ETX and had a genetic architecture typical of highly conjugative plasmids. In the active immunization model of experimental autoimmune encephalomyelitis (EAE), where pertussis toxin (PTX) is used to overcome CNS immune privilege, ETX can substitute for PTX. In contrast to PTX-induced EAE, where inflammatory demyelination is largely restricted to the spinal cord, ETX-induced EAE caused demyelination in the corpus callosum, thalamus, cerebellum, brainstem, and spinal cord, more akin to the neuroanatomical lesion distribution seen in MS. CNS endothelial cell transcriptional profiles revealed ETX-induced genes that are known to play a role in overcoming CNS immune privilege. Together, these findings suggest that ETX-producing C. perfringens strains are biologically plausible pathogens in MS that trigger inflammatory demyelination in the context of circulating myelin autoreactive lymphocytes.
Authors
Yinghua Ma, David Sannino, Jennifer R. Linden, Sylvia Haigh, Baohua Zhao, John B. Grigg, Paul Zumbo, Friederike Dündar, Daniel Butler, Caterina P. Profaci, Kiel Telesford, Paige N. Winokur, Kareem R. Rumah, Susan A. Gauthier, Vincent A. Fischetti, Bruce A. McClane, Francisco A. Uzal, Lily Zexter, Michael Mazzucco, Richard Rudick, David Danko, Evan Balmuth, Nancy Nealon, Jai Perumal, Ulrike Kaunzner, Ilana L. Brito, Zhengming Chen, Jenny Z. Xiang, Doron Betel, Richard Daneman, Gregory F. Sonnenberg, Christopher E. Mason, Timothy Vartanian
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The renal actions of parathyroid hormone (PTH) promote 1,25-vitamin D generation; however, the signaling mechanisms that control PTH-dependent vitamin D activation remain unknown. Here, we demonstrated that salt-inducible kinases (SIKs) orchestrated renal 1,25-vitamin D production downstream of PTH signaling. PTH inhibited SIK cellular activity by cAMP-dependent PKA phosphorylation. Whole-tissue and single-cell transcriptomics demonstrated that both PTH and pharmacologic SIK inhibitors regulated a vitamin D gene module in the proximal tubule. SIK inhibitors increased 1,25-vitamin D production and renal Cyp27b1 mRNA expression in mice and in human embryonic stem cell–derived kidney organoids. Global- and kidney-specific Sik2/Sik3 mutant mice showed Cyp27b1 upregulation, elevated serum 1,25-vitamin D, and PTH-independent hypercalcemia. The SIK substrate CRTC2 showed PTH and SIK inhibitor–inducible binding to key Cyp27b1 regulatory enhancers in the kidney, which were also required for SIK inhibitors to increase Cyp27b1 in vivo. Finally, in a podocyte injury model of chronic kidney disease–mineral bone disorder (CKD-MBD), SIK inhibitor treatment stimulated renal Cyp27b1 expression and 1,25-vitamin D production. Together, these results demonstrated a PTH/SIK/CRTC signaling axis in the kidney that controls Cyp27b1 expression and 1,25-vitamin D synthesis. These findings indicate that SIK inhibitors might be helpful for stimulation of 1,25-vitamin D production in CKD-MBD.
Authors
Sung-Hee Yoon, Mark B. Meyer, Carlos Arevalo, Murat Tekguc, Chengcheng Zhang, Jialiang S. Wang, Christian D. Castro Andrade, Katelyn Strauss, Tadatoshi Sato, Nancy A. Benkusky, Seong Min Lee, Rebecca Berdeaux, Marc Foretz, Thomas B. Sundberg, Ramnik J. Xavier, Charles H. Adelmann, Daniel J. Brooks, Anthony Anselmo, Ruslan I. Sadreyev, Ivy A. Rosales, David E. Fisher, Navin Gupta, Ryuji Morizane, Anna Greka, J. Wesley Pike, Michael Mannstadt, Marc N. Wein
×Abstract
Patient-derived induced pluripotent stem cells (iPSCs) provide a powerful tool for identifying cellular and molecular mechanisms of disease. Macular telangiectasia type 2 (MacTel) is a rare, late-onset degenerative retinal disease with an extremely heterogeneous genetic architecture, lending itself to the use of iPSCs. Whole-exome sequencing screens and pedigree analyses have identified rare causative mutations that account for less than 5% of cases. Metabolomic surveys of patient populations and GWAS have linked MacTel to decreased circulating levels of serine and elevated levels of neurotoxic 1-deoxysphingolipids (1-dSLs). However, retina-specific, disease-contributing factors have yet to be identified. Here, we used iPSC-differentiated retinal pigmented epithelial (iRPE) cells derived from donors with or without MacTel to screen for novel cell-intrinsic pathological mechanisms. We show that MacTel iRPE cells mimicked the low serine levels observed in serum from patients with MacTel. Through RNA-Seq and gene set enrichment pathway analysis, we determined that MacTel iRPE cells are enriched in cellular stress pathways and dysregulation of central carbon metabolism. Using respirometry and mitochondrial stress testing, we functionally validated that MacTel iRPE cells had a reduction in mitochondrial function that was independent of defects in serine biosynthesis and 1-dSL accumulation. Thus, we identified phenotypes that may constitute alternative disease mechanisms beyond the known serine/sphingolipid pathway.
Authors
Kevin T. Eade, Brendan Robert E. Ansell, Sarah Giles, Regis Fallon, Sarah Harkins-Perry, Takayuki Nagasaki, Simone Tzaridis, Martina Wallace, Elizabeth A. Mills, Samaneh Farashi, Alec Johnson, Lydia Sauer, Barbara Hart, M. Elena Diaz-Rubio, Melanie Bahlo, Christian Metallo, Rando Allikmets, Marin L. Gantner, Paul S. Bernstein, Martin Friedlander
×Abstract
Out-of-hospital cardiac arrest is a leading cause of death in the US, with a mortality rate over 90%. Preclinical studies demonstrate that cooling during cardiopulmonary resuscitation (CPR) is highly beneficial, but can be challenging to implement clinically. No medications exist for improving long-term cardiac arrest survival. We have developed a 20–amino acid peptide, TAT-PHLPP9c, that mimics cooling protection by enhancing AKT activation via PH domain leucine-rich repeat phosphatase 1 (PHLPP1) inhibition. Complementary studies were conducted in mouse and swine. C57BL/6 mice were randomized into blinded saline control and peptide-treatment groups. Following a 12-minute asystolic arrest, TAT-PHLPP9c was administered intravenously during CPR and significantly improved the return of spontaneous circulation, mean arterial blood pressure and cerebral blood flow, cardiac and neurological function, and survival (4 hour and 5 day). It inhibited PHLPP-NHERF1 binding, enhanced AKT but not PKC phosphorylation, decreased pyruvate dehydrogenase phosphorylation and sorbitol production, and increased ATP generation in heart and brain. TAT-PHLPP9c treatment also reduced plasma taurine and glutamate concentrations after resuscitation. The protective benefit of TAT-PHLPP9c was validated in a swine cardiac arrest model of ventricular fibrillation. In conclusion, TAT-PHLPP9c may improve neurologically intact cardiac arrest survival without the need for physical cooling.
Authors
Jing Li, Xiangdong Zhu, Matt T. Oberdier, Chunpei Lee, Shaoxia Lin, Sarah J. Fink, Cody N. Justice, Kevin Qin, Andrew W. Begeman, Frederick C. Damen, Hajwa Kim, Jiwang Chen, Kejia Cai, Henry R. Halperin, Terry L. Vanden Hoek
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How cancer cells evade the therapeutic effects of immune checkpoint blockade is largely unknown. Here, we report that fibrinogen-like protein 1 (FGL1), a newly identified immune checkpoint ligand, was modified by acetylation at Lys 98 in hepatocellular carcinoma (HCC), which targeted it for proteasomal degradation. Sirtuin 2 (SIRT2) deacetylated and stabilized FGL1, thus promoting immune evasion. Notably, the SIRT2 inhibitor 2-Cyano-3-[5-(2,5-dichlorophenyl)-2-furanyl]-N-5-quinolinyl-2-propenamide (AGK2) enhanced acetylation of FGL1 and reduced FGL1 protein levels in vitro. The combination of AGK2 and programmed death ligand 1 (PD-L1) blockade effectively suppressed tumor growth and improved overall survival of mice. Furthermore, aspirin, an old drug, could directly acetylate FGL1 at Lys 98 and promote its degradation in vitro. Aspirin enhanced the immunotherapeutic efficacy, induced tumor regression, and extended the lifespan of tumor-bearing mice. Furthermore, the SIRT2/FGL1 axis was expressed in HCC specimens. Collectively, these findings unveil an acetylation-mediated regulation of FGL1, identify a potential target for HCC immunotherapy, and provide therapeutic strategies for the clinical treatment of HCC.
Authors
Mingen Lin, Jing He, Xinchao Zhang, Xue Sun, Wenjing Dong, Ruonan Zhang, Yanping Xu, Lei Lv
×Abstract
Patients with small cell lung cancer (SCLC) generally have a poor prognosis and a median overall survival of only about 13 months, indicating the urgent need for novel therapies. Delta-like protein 3 (DLL3) has been identified as a tumor-specific cell surface marker on neuroendocrine cancers, including SCLC. In this study, we developed a chimeric antigen receptor (CAR) against DLL3 that displays antitumor efficacy in xenograft and murine SCLC models. CAR T cell expression of the proinflammatory cytokine IL-18 greatly enhanced the potency of DLL3-targeting CAR T cell therapy. In a murine metastatic SCLC model, IL-18 production increased the activation of both CAR T cells and endogenous tumor-infiltrating lymphocytes. We also observed an increased infiltration, repolarization, and activation of antigen-presenting cells. Additionally, human IL-18–secreting anti-DLL3 CAR T cells showed an increased memory phenotype, less exhaustion, and induced durable responses in multiple SCLC models, an effect that could be further enhanced with anti–PD-1 blockade. All together, these results define DLL3-targeting CAR T cells that produce IL-18 as a potentially promising novel strategy against DLL3-expressing solid tumors.
Authors
Janneke E. Jaspers, Jonathan F. Khan, William D. Godfrey, Andrea V. Lopez, Metamia Ciampricotti, Charles M. Rudin, Renier J. Brentjens
×Abstract
Chronic pain can cause both hyperalgesia and anxiety symptoms. However, how the two components are encoded in the brain remains unclear. The prelimbic cortex (PrL), a critical brain region for both nociceptive and emotional modulations, serves as an ideal medium for comparing how the two components are encoded. We report that PrL neurons projecting to the basolateral amygdala (PrLBLA) and those projecting to the ventrolateral periaqueductal gray (PrLl/vlPAG) were segregated and displayed elevated and reduced neuronal activity, respectively, during pain chronicity. Consistently, optogenetic suppression of the PrL-BLA circuit reversed anxiety-like behaviors, whereas activation of the PrL-l/vlPAG circuit attenuated hyperalgesia in mice with chronic pain. Moreover, mechanistic studies indicated that elevated TNF-α/TNFR1 signaling in the PrL caused increased insertion of GluA1 receptors into PrLBLA neurons and contributed to anxiety-like behaviors in mice with chronic pain. Together, these results provide insights into the circuit and molecular mechanisms in the PrL for controlling pain-related hyperalgesia and anxiety-like behaviors.
Authors
Feng Gao, Jie Huang, Guo-Bin Huang, Qiang-Long You, Shan Yao, Shen-Ting Zhao, Jian Liu, Cui-Hong Wu, Gui-Fu Chen, Shi-Min Liu, Zongyan Yu, Yan-Ling Zhou, Yu-Ping Ning, Shenquan Liu, Bing-Jie Hu, Xiang-Dong Sun
×Abstract
BACKGROUND Hepatic de novo lipogenesis (DNL) and β-oxidation are tightly coordinated, and their dysregulation is thought to contribute to the pathogenesis of nonalcoholic fatty liver (NAFL). Fasting normally relaxes DNL-mediated inhibition of hepatic β-oxidation, dramatically increasing ketogenesis and decreasing reliance on the TCA cycle. Thus, we tested whether aberrant oxidative metabolism in fasting NAFL subjects is related to the inability to halt fasting DNL.METHODS Forty consecutive nondiabetic individuals with and without a history of NAFL were recruited for this observational study. After phenotyping, subjects fasted for 24 hours, and hepatic metabolism was interrogated using a combination of 2H2O and 13C tracers, magnetic resonance spectroscopy, and high-resolution mass spectrometry.RESULTS Within a subset of subjects, DNL was detectable after a 24-hour fast and was more prominent in those with NAFL, though it was poorly correlated with steatosis. However, fasting DNL negatively correlated with hepatic β-oxidation and ketogenesis and positively correlated with citrate synthesis. Subjects with NAFL but undetectable fasting DNL (25th percentile) were comparatively normal. However, those with the highest fasting DNL (75th percentile) were intransigent to the effects of fasting on the concentration of insulin, non-esterified fatty acid, and ketones. Additionally, they sustained glycogenolysis and were spared the loss of oxaloacetate to gluconeogenesis in favor of citrate synthesis, which correlated with DNL and diminished ketogenesis.CONCLUSION Metabolic flux analysis in fasted subjects indicates that shared metabolic mechanisms link the dysregulations of hepatic DNL, ketogenesis, and the TCA cycle in NAFL.TRIAL REGISTRATION Data were obtained during the enrollment/non-intervention phase of Effect of Vitamin E on Non-Alcoholic Fatty Liver Disease, ClinicalTrials.gov NCT02690792.FUNDING This work was supported by the University of Texas Southwestern NORC Quantitative Metabolism Core (NIH P30DK127984), the NIH/National Institute of Diabetes and Digestive and Kidney Diseases (R01DK078184, R01DK128168, R01DK087977, R01DK132254, and K01DK133630), the NIH/National Institute on Alcohol Abuse and Alcoholism (K01AA030327), and the Robert A. Welch Foundation (I-1804).
Authors
Xiaorong Fu, Justin A. Fletcher, Stanisław Deja, Melissa Inigo-Vollmer, Shawn C. Burgess, Jeffrey D. Browning
Copyright © 2024 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)