Arunagiri et al. report that disrupting endoplasmic reticulum–associated (ER-associated) degradation in pancreatic β cells, by conditional deletion of the ER membrane–associated ubiquitin ligase HRD1, impairs proinsulin synthesis and triggers diabetes in mice. The cover image shows a β cell–specific Hrd1-knockout pancreas, with pancreatic islets (lighter color) nestled within the darker-staining acinar architecture.
Atopic dermatitis (AD) is a chronic inflammatory skin condition characterized by a type 2 immune response that is not fully understood. Single-cell RNA sequencing (scRNA-seq) of human AD skin and murine models of type 2 inflammation identified transcriptionally distinct fibroblast clusters, revealing unique, IL-4Rɑ-dependent populations of immune-acting fibroblasts. These unbiased findings prompted further investigation into the role of dermal fibroblasts during allergic inflammation. These studies demonstrated that, in an inflammatory environment including TNFɑ, IL-1β and IL-17A, IL-4 and IL-13 stimulate both mouse and human fibroblasts to produce multiple chemokines, including Ccl8, which activates Ccr3 to attract T-cells. In the skin, fibroblasts are the primary source of many of these chemokines, and targeted deletion of IL--4rɑ in mouse fibroblasts reduces T-cell infiltration in a mouse model of AD. Additionally, pharmacologic inhibition of Ccr3, the receptor shared by many chemokines produced by fibroblasts, decreases T-cell infiltration and skin inflammation in AD mouse models. These findings demonstrate that dermal fibroblasts are more than passive structural cells; they actively participate in the type 2 immune response and contribute to AD by producing chemokines that increase inflammation. Targeting the functions of immune-acting fibroblasts could offer an alternative therapeutic approach for AD.
Tomofumi Numata, Michael Shia, Yoshiyuki Nakamura, Fengwu Li, Hung Chan, Teruaki Nakatsuji, Kellen J. Cavagnero, Jared Simmons, Henry Li, Aaroh Anand Joshi, Marta Palomo-Irigoyen, Richard L. Gallo
Transitions of cancer cells between distinct cell states, which are typically driven by transcription reprogramming, fuel tumor plasticity, metastasis, and therapeutic resistance. Whether the transitions between cell states can be therapeutically targeted remains unknown. Here, using the epithelial-to-mesenchymal transition (EMT) as a model, we show that the transcription reprogramming during a cell-state transition induces genomic instability through R-loops and transcription-replication conflicts, and the cell-state transition cannot occur without the ATR kinase, a key regulator of the replication stress response. ATR inhibition during EMT not only increases transcription- and replication-dependent genomic instability but also disrupts transcription reprogramming. Unexpectedly, ATR inhibition elevates R-loop-associated DNA damage at the SNAI1 gene, a key driver of the transcription reprogramming during EMT, triggering ATM- and Polycomb-mediated transcription repression of SNAI1. Beyond SNAI1, ATR also suppresses R-loops and antagonizes repressive chromatin at a subset of EMT genes. Importantly, inhibition of ATR in tumors undergoing EMT reduces tumor growth and metastasis, suggesting that ATR inhibition eliminates cancer cells in transition. Thus, during EMT, ATR not only protects genome integrity but also enables transcription reprogramming, revealing that ATR is a safeguard of cell-state transitions and a target to suppress tumor plasticity.
Parasvi S Patel, Jacob P. Matson, Xiaojuan Ran, Marcello Stanzione, Ajinkya S. Kawale, Mingchao Wang, Sneha Saxena, Conrad Sander, Jacquelyn Curtis, Jessica L. Hopkins, Edmond Wong, Ryan B. Corcoran, Daniel A. Haber, Nicholas J. Dyson, Shyamala Maheswaran, Lee Zou
Epidermal growth factor receptor (EGFR)-activating mutations are established biomarkers of resistance to immune checkpoint blockade (ICB) in lung cancer, yet the precise molecular mechanism and effective therapeutic strategies remain elusive. In this study, we show that EGFR overexpression and amplification recapitulate the negative impact of EGFR driver mutations to ICB response, indicating a proactive involvement of EGFR signaling in antagonizing antitumor immune response. Functional studies unveil that EGFR activation suppresses cellular response to interferon-gamma (IFN-γ) following ICB treatment across multiple cancer models. This impairment in IFN-γ responsiveness further limits the upregulation of T cell-recruiting chemokines and antigen presentation, resulting in reduced T cell infiltration and activation, ultimately undermining antitumor immunity. Mechanistically, EGFR promotes SHP2 activation to accelerate STAT1 dephosphorylation, leading to premature termination of the IFN-γ response. SHP2 inhibition restored ICB sensitivity in EGFR-activated tumors, significantly reducing tumor burden while maintaining a favorable safety profile. Our findings suggest that EGFR/SHP2 axis functions as a molecular brake to disrupt the initiation and amplification of IFN-γ mediated anti-tumor response during immunotherapy. This discovery unveils a potential avenue to overcome immunotherapy resistance in EGFR-driven tumors, particularly lung cancer, through SHP2-targeted combination strategies.
Wei-Tao Zhuang, Lan-Lan Pang, Li-Yang Hu, Jun Liao, Jian-Hua Zhan, Ting Li, Ri-Xin Chen, Jia-Ni Zheng, An-Lin Li, Wen-Yan Yu, Tian-Qin Mao, Liang Chen, Yu-Jian Huang, Shao-Dong Hong, Jing Li, Jun-Han Wu, Yi-Ming Zeng, Meng-Juan Yang, Hai-Qing Zeng, Ya-Xiong Zhang, Li Zhang, Wen-Feng Fang
Dysregulation of cell cycle checkpoints is a cancer hallmark with ubiquitination controlled protein stability playing pivotal roles. Although p21, a key cyclin-dependent kinase inhibitor, is tightly regulated by ubiquitin-mediated degradation, the key upstream modulators of its ubiquitination remain incompletely defined. Here, we identify poly(ADP-ribose) glycohydrolase (PARG) as a regulator of p21 stability in gastric cancer (GC) cells. We show that PARG expression is markedly upregulated in GC tissues and correlates with poor patient prognosis. Functional assays revealed that genetic depletion of PARG triggers G2/M phase arrest and impairs GC cell proliferation. Mechanistically, we demonstrate that PARG loss enhances p21 PARylation, which disrupts its association with E3 ubiquitin ligase, thereby reducing K48-linked ubiquitination and leading to p21 protein stabilization. Moreover, we identify lysine residues K161 and K163 as critical sites for PARG-mediated regulation of p21 ubiquitination. Our findings reveal a post-translational regulatory axis in which PARG governs cell cycle progression by modulating the PARylation-dependent ubiquitination of p21. These results broaden the understanding of p21 regulation in cancer and highlight PARG as a potential therapeutic target for GC treatment.
Yangchan Hu, Qimei Bao, Yixing Huang, Yan Wang, Xin Zhao, Junjun Nan, Yuxin Meng, Mingcong Deng, Yuancong Li, Zirui Zhuang, Hanyi He, Dan Zu, Yuke Zhong, Chunkai Zhang, Bing Wang, Ran Li, Yanhua He, Qihan Wang, Min Liu, John A. Tainer, Yin Shi, Xiangdong Cheng, Ji Jing, Zu Ye
Drug-associated environmental cues can trigger drug-seeking behavior and precipitate relapse. In the current study, we identified that the claustrum (CL) connects the ventral tegmental area (VTA) with the medial prefrontal cortex (mPFC), forming the VTA–CL–mPFC circuit. By using methamphetamine (METH) conditioned place preference (CPP) model in male mice, we found that manipulating the VTA–CL–mPFC circuit or CL neuronal ensemble receiving projections from VTA and projecting to mPFC (VTA–CL–mPFC) could disrupt the retrieval of METH-paired context memory, resulting in the blockage of the acquisition of METH CPP in male mice. During the process, dopamine (DA) release and dopamine 1-like receptor (D1R)-mediated the activation of CL neurons were required for the retrieval of METH-induced reward memory in male mice. These findings reveal a midbrain-to-cortical circuit orchestrated by CL neurons, which plays an essential role in the retrieval of drug-paired environmental cue memory.
Ziheng Zhao, Yuhong He, Yang Liu, Quying Feng, Hee Young Kim, Yu Fan, Xiaowei Guan
Therapies targeting the glucagon-like peptide 1 (GLP-1) receptor have revolutionized the treatment of obesity and diabetes. This series of reviews, curated by Dr. Dan Drucker, describes the latest research in this fast-moving in field, from our evolving understanding of the mechanism of GLP-1 receptor signaling to the medicines’ impact on inflammation and the consequences for heart, kidney, and brain health. The reviews also explore the impact of these medicines on conditions beyond their initial indications, including cancer and neurodegenerative disease risk.
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In this episode, Dr. Seth J. Zost presents an antibody lineage from a single donor that binds the active site of influenza neuraminidase, cross-reacts with antigenically diverse viruses, and protects mice from infection...