Diet-induced obesity promotes endothelial cell desensitization to VEGF-A and permanent islet vessel dysfunction in mice

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Abstract

Pancreatic islet microvasculature is essential for optimal islet function and glucose homeostasis. However, islet vessel pathogenesis in obesity and its role in the manifestation of metabolic disorders remain understudied. Here, we depict the time-resolved decline of intra-islet endothelial cell responsiveness to vascular endothelial cell growth factor A (VEGF-A) and islet vessel function in a mouse model of diet-induced obesity. Longitudinal imaging of sentinel islets transplanted into mouse eyes revealed substantial vascular remodeling and diminished VEGF-A response in islet endothelial cells after 12 weeks of western diet (WD) feeding. This led to islet vessel barrier dysfunction and hemodynamic dysregulation, delaying transportation of secreted insulin into the blood. Notably, islet vessels exhibited a metabolic memory of previous WD feeding. Neither VEGF-A sensitivity nor the other vascular alterations was fully restored by control diet (CD) refeeding, resulting in modest yet significant impairment in glucose clearance despite normalized insulin sensitivity. Mechanistic analysis implicated hyperactivation of atypical protein kinase C (aPKC) under both WD and recovery conditions, which inhibited VEGF receptor 2 (VEGFR2) internalization and blunted VEGF-A triggered signal transduction in endothelial cells. In summary, prolonged WD feeding causes irreversible islet endothelial cell desensitization to VEGF-A and islet vessel dysfunction, directly undermining glucose homeostasis.

Authors

Yan Xiong, Andrea Dicker, Montse Visa, Erwin Ilegems, Per-Olof Berggren

CAR-T cells targeting CD155 reduce tumor burden in preclinical models of leukemia and solid tumors

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Abstract

CAR-T cells are a powerful yet expensive tool in cancer immunotherapy. While their use in targeting hematological malignancies is well-established, using a single CAR-T cell therapy to treat both hematological and solid tumors, which can reduce cost, remains largely unexplored. In this study, we identified CD155, an adhesion molecule that is upregulated during tumor progression, as a target for CAR-T cell therapy in both leukemia and solid tumors. We engineered CAR-T cells using human and mouse anti-CD155 antibodies generated from a Berkeley Lights' Beacon platform. These CAR-T cells demonstrated potent anti-tumor activity, significantly reducing tumor burden in preclinical models of acute myeloid leukemia (AML), non-small cell lung cancer (NSCLC), and pancreatic cancer. To reduce potential allogeneic rejection, we generated CAR-T cells using humanized anti-CD155 antibody sequences that retained efficacy. Additionally, murine CAR-T cells targeting mouse CD155 exhibited limited toxic side effects in immunocompetent mice, highlighting the favorable safety profile of this therapy. These findings suggest that CD155 can be targeted by CD155 CAR-T cells safely and effectively, representing an innovative cellular therapeutic strategy that has the potential to expand its scope across both AML and multiple solid tumors, thereby lowering the cost of cellular immunotherapy, especially as allogenic, universal and off-the-shelf CAR-T cell therapies advance to the clinic.

Authors

Tianchen Xiong, Ge Wang, Peng Yu, Zhenlong Li, Debao Li, Jianying Zhang, Song Lu, Ruiqi Yang, Xiaolong Lian, Jianhong Mi, Rui Ma, Zhiyao Li, Guido Marcucci, Tingting Zhao, Michael A. Caligiuri, Jianhua Yu

Panose prevents acute-on-chronic liver failure by reducing bacterial infection in mice

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Abstract

Acute-on-chronic liver failure (ACLF) is a leading cause of global liver-related mortality. Bacterial infection, especially in patients with decompensated cirrhosis (DC), commonly triggers ACLF and is difficult to treat with antibiotics. Therefore, finding alternative strategies for preventing and managing bacterial infection is an urgent priority. Here, we observed that infected DC patients and ACLF mice exhibited lower fecal panose levels than uninfected controls. Megamonas funiformis (M. funiformis), with 4α-glucanosyltransferase (4αGT) as a key enzyme for panose production, was identified as a potential panose producer. Animal experiments demonstrated that panose efficiently reduced liver injury and extended survival in ACLF mice by mitigating bacterial infection. Further results revealed that panose enhanced resistance to bacterial infection by inhibiting oxidative stress-induced gut barrier disruption, thereby limiting bacterial dissemination. Mechanistically, panose interacted with the solute carrier family 7 member 11 (SLC7A11, also known as xCT) protein to boost antioxidant glutathione (GSH) levels in intestinal epithelial cells. These findings highlight panose's potential in preventing bacterial infection, offering a valuable insight into mitigating ACLF progression.

Authors

Jiaxin Li, Shihao Xie, Meiling Chen, Changze Hong, Yuqi Chen, Fengyuan Lyu, Niexin Tang, Tianqi Chen, Lingyan Zhao, Weihao Zou, Hongjuan Peng, Jingna Bao, Peng Gu, Bernd Schnabl, Jinjun Chen, Peng Chen

CXCL10 secreted by SPRY1-deficient epidermal keratinocytes fuels joint inflammation in psoriatic arthritis via CD14 signaling

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Abstract

Psoriatic arthritis (PsA) is a multifaceted chronic inflammatory disease affecting the skin, joints, and entheses, and is a major comorbidity of psoriasis. Most patients with PsA present with psoriasis before articular involvement, however, the molecular and cellular mechanisms underlying the link between cutaneous psoriasis and PsA are poorly understood. Here, we found that epidermal-specific SPRY1-deficient mice spontaneously developed PsA-like inflammation involving both the skin and joints. Excessive CXCL10 was secreted by SPRY1-deficient epidermal keratinocytes through enhanced activation of JAK1/2-STAT1 signaling, and CXCL10 blockade attenuated PsA-like inflammation. Of note, CXCL10 was found to bind to CD14, but not CXCR3, to promote the TNF𝜶 production of periarticular CD14hi macrophages via PI3K/AKT and NF-κB signaling pathways. Collectively, this study reveals that SPRY1 deficiency in the epidermis is sufficient to drive both skin and joint inflammation, and identifies keratinocyte-derived CXCL10 and periarticular CD14hi macrophages as critical links in the skin-joint crosstalk leading to PsA. This keratinocyte SPRY1-CXCL10-periarticular CD14hi macrophages-TNFα axis provides valuable insights into the mechanisms underlying the transition from psoriasis to PsA and suggests potential therapeutic targets for preventing this progression.

Authors

Fan Xu, Ying-Zhe Cui, Xing-Yu Yang, Yu-Xin Zheng, Xi-Bei Chen, Hao Zhou, Zhao-Yuan Wang, Yuan Zhou, Yi Lu, Ying-Ying Li, Li-Ran Ye, Ni-Chang Fu, Si-Qi Chen, Xue-Yan Chen, Min Zheng, Yong Yang, Xiao-Yong Man

The microRNA miR-30a blocks adipose tissue fibrosis accumulation in obesity

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Abstract

White adipose tissue (WAT) fibrosis occurring in obesity contributes to the inflammatory and metabolic co-morbidities of insulin resistance and type 2 diabetes, yet the mechanisms involved remain poorly understood. Here, we report a role for the broadly conserved microRNA miR-30a as a regulator of WAT fibrosis and systemic glucose metabolism. Mice modified to express miR-30a at elevated levels in adipose tissues maintain insulin sensitivity coupled with reduced fatty liver disease when fed high fat diet. These effects were attributable to cell-autonomous functions of miR-30a that potently increase expression of adipocyte-specific genes. Proteomic screening revealed miR-30a limits pro-fibrotic programs in subcutaneous WAT, at least in part, by repressing PAI-1, a dominant regulator of fibrinolysis and biomarker of insulin resistance. Conversely, mouse adipocytes lacking miR-30a exhibited greater expression of fibrosis markers with disrupted cellular metabolism. Lastly, miR-30a expression negatively correlates with PAI-1 levels in subcutaneous WAT from people with obesity, further supporting an anti-fibrotic role for miR-30a. Together, these findings uncover miR-30a as a critical regulator of adipose tissue fibrosis that predicts metabolically healthy obesity in people and mice.

Authors

Pradip K. Saha, Robert Sharp, Aaron R. Cox, Rabie Habib, Michael J. Bolt, Jessica B. Felix, Claudia E. Ramirez Bustamante, Xin Li, Sung Yun Jung, Kang Ho Kim, Kai Sun, Huaizhu Wu, Samuel Klein, Sean M. Hartig

FGFR3-induced Y158 PARP1 phosphorylation promotes PARP-inhibitor resistance via BRG1/MRE11-mediated DNA repair in breast cancer models

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Abstract

Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) are used to treat BRCA-mutated (BRCAm) cancer patients; however, resistance has been observed. Therefore, biomarkers to indicate PARPi resistance and combination therapy to overcome that are urgently needed. We identified a high prevalence of activated FGF receptor 3 (FGFR3) in BRCAm triple-negative breast cancer (TNBC) cells with intrinsic and acquired PARPi resistance. FGFR3 phosphorylated PARP1 at tyrosine 158 (Y158) to recruit BRG1 and prolong chromatin-loaded MRE11, thus promoting homologous recombination (HR) to enhance PARPi resistance. FGFR inhibition prolonged PARP trapping and synergized with PARPi in vitro and in vivo. High-level PARP1 Y158 phosphorylation (p-Y158) positively correlated with PARPi resistance in TNBC patient-derived xenograft models, and in PARPi-resistant TNBC patient tumors. These findings reveal that PARP1 p-Y158 facilitates BRG1-mediated HR to resolve the PARP-DNA complex, and PARP1 p-Y158 may indicate PARPi resistance that can be relieved by combining FGFR inhibitors (FGFRi) with PARPi. In summary, we show that FGFRi restores PARP trapping and PARPi antitumor efficacy in PARPi-resistant breast cancer by decreasing HR through the PARP1 p-Y158/BRG1/MRE11 axis, suggesting that PARP1 p-Y158 is a biomarker for PARPi resistance that can be overcome by combining FGFRi with PARPi.

Authors

Mei-Kuang Chen, Hirohito Yamaguchi, Yuan Gao, Weiya Xia, Jeffrey T. Chang, Yu-Chun Hsiao, Tewodros W. Shegute, Zong-Shin Lin, Chen-Shiou Wu, Yu-Han Wang, Jennifer K. Litton, Qingqing Ding, Yongkun Wei, Yu-Yi Chu, Funda Meric-Bernstam, Helen Piwnica-Worms, Banu Arun, Jordi Rodon Ahnert, Jinsong Liu, Jun Yao, Wei-Chao Chang, Hung-Ling Wang, Coya Tapia, Constance T. Albarracin, Khandan Keyomarsi, Shao-Chun Wang, Ying-Nai Wang, Gabriel N. Hortobagyi, Chunru Lin, Liuqing Yang, Dihua Yu, Mien-Chie Hung

Mutant THAP11 causes cerebellar neurodegeneration and triggers TREM2-mediated microglial activation in mice

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Abstract

Abnormal expansions of CAG trinucleotide repeat within specific gene exons give rise to polyglutamine (polyQ) diseases, a family of inherited disorders characterized by late-onset neurodegeneration. Recently, a new type of polyQ disease was identified and named spinocerebellar ataxia 51 (SCA51). SCA51 is caused by polyQ expansion in THAP11, an essential transcription factor for brain development. The pathogenesis of SCA51, particularly how mutant THAP11 with polyQ expansion contributes to neuropathology, remains elusive. Our study of mouse and monkey brains revealed that THAP11 expression is subject to developmental regulation, showing enrichment in the cerebellum. However, knocking down endogenous THAP11 in adult mice does not affect neuronal survival. In contrast, expressing mutant THAP11 with polyQ expansion leads to pronounced protein aggregation, cerebellar neurodegeneration, and motor deficits, indicating that gain-of-function mechanisms are central to SCA51 pathogenesis. We discovered activated microglia expressing TREM2 in the cerebellum of a newly developed SCA51 knock-in mouse model. Mechanistically, mutant THAP11 enhances the transcription of TREM2, leading to its upregulation. The loss of TREM2 or depletion of microglia mitigates neurodegeneration induced by mutant THAP11. Our study offers the first mechanistic insights into the pathogenesis of SCA51, highlighting the role of TREM2-mediated microglial activation in SCA51 neuropathology.

Authors

Eshu Ruan, Jingpan Lin, Zhao Chen, Qianai Sheng, Laiqiang Chen, Jiating He, Xuezhi Duan, Yiyang Qin, Tingting Xing, Sitong Yang, Mingtian Pan, Xiangyu Guo, Peng Yin, Xiao-Jiang Li, Hong Jiang, Shihua Li, Su Yang

Tumor microenvironment of non-small cell lung cancer impairs immune cell function among people with HIV

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Abstract

Lung cancer is the leading cause of cancer mortality among people with HIV (PWH), with increased incidence and poor outcomes. This study explored whether the tumor microenvironment (TME) of HIV-associated non-small cell lung cancer (NSCLC) limits tumor-specific immune responses. With a matched cohort of NSCLC from PWH and people without HIV (PWOH), we used imaging mass cytometry, linear mixed effects model and AI-based pageRank mathematical algorithm based on spectral graph theory to demonstrate that HIV-associated tumors demonstrate differential distribution of tumor infiltrating CD8+ and CD4+ T cells, enriched for the expression of PD-1 and Lag-3, as well as activation and proliferation markers. We also demonstrate higher expression of immunoregulatory molecules (PD-L1, PD-L2, B7-H3, B7-H4, IDO1 and VISTA), among tumor-associated macrophages. Discrimination of cells between tumors from PWH versus PWOH was confirmed by spectral graph theory with 84.6% accuracy. Furthermore, we noted differences in spatial orientation of immune cells within the TME of PWH compared to PWOH. Additionally, cells from PWH, compared to PWOH, exhibited decreased tumor killing when exposed to HLA-matched NSCLC cell lines. In conclusion, our study demonstrates that the HIV-associated tumor microenvironment sustains a unique immune landscape, with evidence of immune cells with enhanced immunoregulatory phenotypes and impaired anti-tumor responses, with implications for response to immune checkpoint blocker therapies.

Authors

Shruti S. Desai, Syim Salahuddin, Ramsey Yusuf, Kishu Ranjan, Jianlei Gu, Lais Osmani, Ya-Wei Eileen Lin, Sameet Mehta, Ronen Talmon, Insoo Kang, Yuval Kluger, Hongyu Zhao, Kurt A. Schalper, Brinda Emu

Immune cells promote paralytic disease in mice infected with enterovirus D68

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Abstract

Enterovirus D68 (EV-D68) is associated with acute flaccid myelitis (AFM), a poliomyelitis-like illness causing paralysis in young children. However, mechanisms of paralysis are unclear, and antiviral therapies are lacking. To better understand EV-D68 disease, we inoculated newborn mice intracranially to assess viral tropism, virulence, and immune responses. Wild-type (WT) mice inoculated intracranially with a neurovirulent strain of EV-D68 showed infection of spinal cord neurons and developed paralysis. Spinal tissue from infected mice revealed increased chemokines, inflammatory monocytes, macrophages, and T cells relative to controls, suggesting that immune cell infiltration influences pathogenesis. To define the contribution of cytokine-mediated immune cell recruitment to disease, we inoculated mice lacking CCR2, a receptor for several EV-D68-upregulated cytokines, or RAG1, which is required for lymphocyte maturation. WT, Ccr2-/-, and Rag1-/- mice had comparable viral titers in spinal tissue. However, Ccr2-/- and Rag1-/- mice were significantly less likely to be paralyzed relative to WT mice. Consistent with impaired T cell recruitment to sites of infection in Ccr2-/- and Rag1 -/- mice, antibody-mediated depletion of CD4+ or CD8+ T cells from WT mice diminished paralysis. These results indicate that immune cell recruitment to the spinal cord promotes EV-D68-associated paralysis and illuminate new targets for therapeutic intervention.

Authors

Mikal A. Woods Acevedo, Jie Lan, Sarah Maya, Jennifer E. Jones, Isabella E. Bosco, John V. Williams, Megan C. Freeman, Terence S. Dermody

Hyperinsulinemia-induced upregulation of adipocyte TPH2 contributes to peripheral serotonin production, metabolic dysfunction, and obesity

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Abstract

Tryptophan hydroxylase (TPH) is a rate-limiting enzyme for serotonin or 5-hydroxytryptamine (5-HT) synthesis. Previously, adipocyte TPH1 has been linked to increased adipose 5-HT, reduced BAT thermogenesis, and obesity. However, the role of TPH2, a neural isoform highly expressed in obese adipose tissue, is unknown. Here, we report that adipose tissue expression of TPH2 is significantly elevated in both diet-induced obese (DIO) and ob/ob mice, as well as in obese humans. In high-fat diet (HFD)-fed mice, adipocyte TPH2 deficiency improves DIO-induced metabolic complications, enhances BAT thermogenesis, and increases intestinal energy harvesting efficiency without affecting adiposity. Conversely, TPH2 overexpression in epididymal adipocytes of chow-fed mice raises adipose and plasma 5-HT levels, suppresses BAT thermogenesis, and exacerbates obesity and metabolic dysfunction. We found that obesity-induced hyperinsulinemia upregulates adipocyte TPH2 expression via activation of mechanistic target of rapamycin complex 1 (mTORC1) and sterol regulatory element binding protein 1 (SREBP1). In humans, TPH2 mRNA levels in subcutaneous adipose tissue, but not TPH1, is positively correlated with fasting plasma insulin concentrations. In summary, our study demonstrates that obesity-associated increases in adipocyte TPH2 can regulate distal tissue physiology and energy metabolism, suggesting that TPH2 could be a potential therapeutic target for obesity and its associated complications.

Authors

Brian I. Park, Andrew R. Reeves, Ying Zhu, Robin A. Wilson, Sophia C. Fernandes, Kimberly K. Buhman, Kelli A. Lytle, Michael D. Jensen, Andrew S. Greenberg