In this issue, review articles by Zeng et al. and Smith et al. explore current thoughts on nonopioid targets for treating acute pain and sex differences in the transition from acute to chronic pain. These reviews highlight recent and ongoing research efforts to develop a better understanding of pain, factors involved in the transition to chronic pain, and innovative approaches to pain management. Image credit: Kathleen Sluka (kathleenslukaart.com).
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.
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
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.
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
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.
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
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.
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
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.
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
The complement system executes an evolutionarily ancient innate immune response with important roles in many human diseases, including a variety of conditions involving the kidney, autoimmune disorders, age-related macular degeneration, and more. This series of reviews, curated by Dr. Claudia Kemper, highlights the latest discoveries in complement biology and examines ongoing efforts to target complement therapeutically. From the relatively newly uncovered functions of intracellular complement (complosome) to the complexities involved in using animal models of complementopathies, these reviews convey the challenges of studying complement and developing complement-targeted therapeutics as well as call attention to recent findings that supply momentum to the field.
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