Sec13 promotes oligodendrocyte differentiation and myelin repair through autocrine pleiotrophin signaling

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Abstract

Dysfunction of protein trafficking has been intensively associated with neurological diseases, including neurodegeneration, but whether and how protein transport contributes to oligodendrocyte maturation and myelin repair in white matter injury remains unclear. ER-to-Golgi trafficking of newly synthesized proteins is mediated by the coat protein complex II (COPII) complex. Here we demonstrate that COPII component Sec13 is essential for oligodendrocyte differentiation and postnatal myelination. Ablation of Sec13 in oligodendrocyte lineage prevented OPC differentiation and inhibited myelination and remyelination after demyelinating injury in central nervous system (CNS), while improving protein traffic by tauroursodeoxycholic acid (TUDCA) or ectopic expression of COPII components accelerated myelination. COPII components were upregulated in oligodendrocyte lineage cells after demyelinating injury. Loss of Sec13 altered the secretome of oligodendrocytes and inhibited the secretion of PTN, which was identified to function as an autocrine factor to promote oligodendrocyte differentiation and myelin repair. These data suggest that Sec13-dependent protein transport is essential for oligodendrocyte differentiation and Sec13-mediated PTN autocrine signaling is required for proper myelination and remyelination.

Authors

Zhixiong Liu, Minbiao Yan, Wanying Lei, Rencai Jiang, Wenxiu Dai, Jialin Chen, Chaomeng Wang, Li Li, Mei Wu, Ximing Nian, Daopeng Li, Di Sun, Xiaoqi Lv, Chaoying Wang, Changchuan Xie, Luming Yao, Caiming Wu, Jin Hu, Naian Xiao, Wei Mo, Zhanxiang Wang, Liang Zhang

SENP7 senses oxidative stress to sustain metabolic fitness and antitumor functions of CD8⁺ T cells

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Abstract

The functional integrity of CD8+ T cells is tightly coupled to metabolic reprogramming, but how oxidative stress directs CD8+ T cell metabolic fitness in the tumor microenvironment (TME) remains elusive. Here, we report that SUMO-specific protease 7 (SENP7) senses oxidative stress to maintain the CD8+ T cell metabolic state and antitumor functions. SENP7-deficient CD8+ T cells exhibited decreased glycolysis and oxidative phosphorylation, resulting in attenuated proliferation in vitro and dampened antitumor functions in vivo. Mechanistically, CD8+ T cell-derived reactive oxygen species (ROS) triggered cytosolic SENP7-mediated PTEN deSUMOylation, thereby promoting PTEN degradation and preventing PTEN-dependent metabolic defects. Importantly, lowering T cell-intrinsic ROS restricted SENP7 cytosolic translocation and repressed CD8+ T cell metabolic and functional activity in human colorectal cancer samples. Our findings reveal that SENP7, as an oxidative stress sensor, sustains CD8+ T cell metabolic fitness and effector functions and unveil an oxidative stress-sensing machinery in tumor-infiltrating CD8+ T cells.

Authors

Zhongqiu Wu, Haiyan Huang, Qiaoqiao Han, Zhilin Hu, Xiao-Lu Teng, Rui Ding, Youqiong Ye, Xiaoyan Yu, Ren Zhao, Zhengting Wang, Qiang Zou

Intermittent glucocorticoid treatment enhances skeletal muscle performance through sexually dimorphic mechanisms

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Abstract

Glucocorticoid steroids are commonly prescribed for many inflammatory conditions, but chronic daily use produces adverse effects including muscle wasting and weakness. In contrast, shorter glucocorticoid pulses may improve athletic performance, although the mechanisms remain unclear. Muscle is sexually dimorphic and comparatively little is known about how male and female muscles respond to glucocorticoid steroids. We investigated the impact of once-weekly glucocorticoid exposure on skeletal muscle performance comparing male and female mice. One month of once-weekly glucocorticoid dosing improved muscle specific force in both males and females. Transcriptomic profiling of isolated myofibers identified a striking sexually dimorphic response to weekly glucocorticoids. Male myofibers had increased expression of genes in the IGF1/PI3K pathway and calcium handling, while female myofibers had profound upregulation of lipid metabolism genes. Muscles from weekly prednisone-treated males had improved calcium handling, while comparably treated female muscles had reduced intramuscular triglycerides. Consistent with altered lipid metabolism, weekly prednisone-treated female mice had greater endurance relative to controls. Using chromatin immunoprecipitation, we defined a sexually dimorphic chromatin landscape after weekly prednisone. These results demonstrate that weekly glucocorticoid exposure elicits distinct pathways in males versus females resulting in enhanced performance.

Authors

Isabella M. Salamone, Mattia Quattrocelli, David Y. Barefield, Patrick G. Page, Ibrahim Tahtah, Michele Hadhazy, Garima Tomar, Elizabeth M. McNally

Developmental endothelial locus-1 protects from hypertension-induced cardiovascular remodeling via immunomodulation

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Abstract

The causative role of inflammation in hypertension-related cardiovascular diseases is evident and calls for development of specific immunomodulatory therapies. We tested the therapeutic efficacy and mechanisms of action of developmental endothelial locus-1 (DEL-1), an endogenous anti-inflammatory factor, in angiotensin-II (ANGII)- and DOCA (deoxycorticosterone acetate)-salt-induced cardiovascular organ damage and hypertension. By using mice with endothelial overexpression of DEL-1 (EC-Del1) and performing preventive and interventional studies by injecting recombinant DEL-1 in mice, we showed that DEL-1 improved endothelial function and abrogated aortic adventitial fibrosis, medial thickening and loss of elastin. DEL-1 also protected the mice from cardiac concentric hypertrophy, interstitial and perivascular coronary fibrosis and improved left-ventricular function and myocardial coronary perfusion. DEL-1 prevented aortic stiffness and abolished the progression of hypertension. Mechanistically, DEL-1 acted by inhibiting αvβ3-integrin dependent activation of pro-MMP2 in mice and in human isolated aorta. Moreover, DEL-1 stabilized αvβ3-integrin dependent CD25+FoxP3+ Treg numbers and IL-10 levels, which were associated with decreased pro-inflammatory cell recruitment of inflammatory cells and reduced production of pro-inflammatory cytokines in cardiovascular organs. The demonstrated effects and immune-modulating mechanisms of DEL-1 in abrogation of cardiovascular remodeling and progression of hypertension identify DEL-1 as a potential therapeutic factor.

Authors

Theresa Failer, Michael Amponsah-Offeh, Aleš Neuwirth, Ioannis Kourtzelis, Pallavi Subramanian, Peter Mirtschink, Mirko Peitzsch, Klaus Matschke, Sems M. Tugtekin, Tetsuhiro Kajikawa, Xiaofei Li, Anne Steglich, Florian Gembardt, Annika C. Wegner, Christian Hugo, George Hajishengallis, Triantafyllos Chavakis, Andreas Deussen, Vladimir Todorov, Irakli Kopaliani

YAP mediates compensatory cardiac hypertrophy through aerobic glycolysis in response to pressure overload

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Abstract

The heart utilizes multiple adaptive mechanisms to maintain pump function. Compensatory cardiac hypertrophy reduces wall stress and oxygen consumption, thereby protecting the heart against acute blood pressure elevation. The nuclear effector of the Hippo pathway, Yes-associated protein 1 (YAP), is activated and mediates compensatory cardiac hypertrophy in response to acute pressure overload (PO). In this study, YAP promoted glycolysis by upregulating glucose transporter 1 (GLUT1), which in turn caused accumulation of intermediates and metabolites of the glycolytic, auxiliary, and anaplerotic pathways during acute PO. Cardiac hypertrophy was inhibited and heart failure was exacerbated in mice with YAP haploinsufficiency in the presence of acute PO. However, normalization of GLUT1 rescued the detrimental phenotype. PO induced accumulation of glycolytic metabolites, including L-serine, L-aspartate, and malate, in a YAP-dependent manner, thereby promoting cardiac hypertrophy. YAP upregulated the GLUT1 gene through interaction with TEAD1 and HIF-1α in cardiomyocytes. Thus, YAP induces compensatory cardiac hypertrophy through activation of the Warburg effect.

Authors

Toshihide Kashihara, Risa Mukai, Shin-ichi Oka, Peiyong Zhai, Yasuki Nakada, Zhi Yang, Wataru Mizushima, Tsutomu Nakahara, Junco S. Warren, Maha Abdellatif, Junichi Sadoshima

Single-cell RNA sequencing reveals induction of distinct trained immunity programs in human monocytes

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Abstract

Trained immunity refers to the long-lasting memory traits of innate immunity. Recent studies have shown that trained immunity is orchestrated by sustained changes in epigenetic marks and metabolic pathways, leading to an altered transcriptional response towards a second challenge. However, the potential heterogeneity of trained immunity induction in innate immune cells has not been explored. In this study, we demonstrate cellular transcriptional programs to four different inducers of trained immunity in monocyte populations at single-cell resolution. Specifically, we identified three monocyte subpopulations upon the induction of trained immunity, and replicated these findings in an in vivo study. In addition, we found gene signatures consistent with these functional programs in ulcerative colitis, sepsis and COVID-19 patients, suggesting the impact of trained immunity programs in immune-mediated diseases.

Authors

Bowen Zhang, Simone J.C.F.M. Moorlag, Jorge Domínguez-Andrés, Özlem Bulut, Gizem Kilic, Zhaoli Liu, Reinout van Crevel, Cheng-Jian Xu, Leo A.B. Joosten, Mihai G. Netea, Yang Li

The HIV-1 proviral landscape reveals Nef contributes to HIV-1 persistence in effector memory CD4+ T-cells

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Abstract

Despite long-term antiretroviral therapy (ART), HIV-1 persists within a reservoir of CD4+ T-cells that contribute to viral rebound if treatment is interrupted. Identifying the cellular populations that contribute to the HIV-1 reservoir and understanding the mechanisms of viral persistence are necessary to achieve an effective cure. In this regard, through Full-Length Individual Proviral Sequencing, we observed that the HIV-1 proviral landscape was different and changed with time on ART across naïve and memory CD4+ T-cell subsets isolated from 24 participants. We found that the proportion of genetically-intact HIV-1 proviruses was higher and persisted over time in effector memory CD4+ T-cells when compared with naïve, central, and transitional memory CD4+ T-cells. Interestingly, we found that escape mutations remained stable over time within effector memory T-cells during therapy. Finally, we provided evidence that Nef plays a role in the persistence of genetically-intact HIV-1. These findings posit effector memory T-cells as a key component of the HIV-1 reservoir and suggest Nef as an attractive therapeutic target.

Authors

Gabriel Duette, Bonnie Hiener, Hannah Morgan, Fernando G. Mazur, Vennila Mathivanan, Bethany A. Horsburgh, Katie Fisher, Orion Tong, Eunok Lee, Haelee Ahn, Ansari Shaik, Rémi Fromentin, Rebecca Hoh, Charline Bacchus-Souffan, Najla Nasr, Anthony Cunningham, Peter W. Hunt, Nicolas Chomont, Stuart G. Turville, Steven G. Deeks, Anthony D. Kelleher, Timothy E. Schlub, Sarah Palmer

An Asian-specific variant in human IgG1 represses colorectal tumorigenesis by shaping the tumor microenvironment

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Abstract

Emerging studies have focused on ways to treat cancers by modulating T cell activation. However, whether B cell receptor signaling in the tumor microenvironment (TME) can be harnessed for immunotherapy is unclear. Here we reported that an Asian-specific variant of human IgG1 containing a Gly396 to Arg396 substitution (hIgG1-G396R) conferred improved survival of colorectal cancer (CRC) patients. Murine functional homolog mIgG2c-G400R knock-in mice recapitulated the alleviated tumorigenesis and progression in murine colon carcinoma models. Immune profiling of the TME revealed broad mobilizations of IgG1+ plasma cells, CD8+ T cells, CD103+ DCs and active tertiary lymphoid structure formation, suggesting effective anti-tumor microenvironment in hIgG1-G396R CRC patients. Mechanistically, this variant potentiated tumor-associated antigen (TAA)-specific plasma cell differentiation and thus antibody production. These elevated TAA-specific IgG2c antibodies in turn efficiently boosted the antibody-dependent tumor cell phagocytosis and TAA presentation to effector CD8+ T cells. Notably, adoptive transfer of TAA-specific class-switched memory B cells harboring this variant exhibited therapeutic efficacy in murine tumor models, indicating the clinical potential. All these results prompted a prospective investigation of hIgG1-G396R in CRC patients as a biomarker for clinical prognosis and demonstrated that manipulating the functionality of IgG1+ memory B cells in tumors could improve immunotherapy outcomes.

Authors

Bing Yang, Zhen Zhang, Xiangjun Chen, Xu-Yan Wang, Shishang Qin, Liaoqi Du, Changjiang Yang, Liyu Zhu, Wenbo Sun, Yongjie Zhu, Qinwen Zheng, Shidong Zhao, Quan Wang, Long Zhao, Yilin Lin, Jinghe Huang, Fan Wu, Lu Lu, Fei Wang, Wenjie Zheng, Xiao-Hua Zhou, Xiaozhen Zhao, Ziye Wang, Xiaolin Sun, Yingjiang Ye, Shan Wang, Zhanguo Li, Hai Qi, Zemin Zhang, Dong-Ming Kuang, Lei Zhang, Zhanlong Shen, Wanli Liu

ADAR1-mediated RNA editing links ganglioside catabolism to glioblastoma stem cell maintenance

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Abstract

Glioblastoma (GBM) is the most common and lethal primary malignant brain tumor, containing GBM stem cells (GSCs) that contribute to therapeutic resistance and relapse. Exposing potential GSC vulnerabilities may provide therapeutic strategies against GBM. Here, we interrogated the role of Adenosine-to-Inosine (A-to-I) RNA editing mediated by ADAR1 (adenosine deaminase acting on RNA 1) in GSCs and found that both ADAR1 and global RNA editomes were elevated in GSCs compared to normal neural stem cells (NSCs). ADAR1 inactivation or blocking the upstream JAK/STAT pathway through TYK2 inhibition impaired GSC self-renewal and stemness. Downstream of ADAR1, RNA editing of the 3’UTR of GM2A, a key ganglioside catabolism activator, proved to be critical, as interfering with ganglioside catabolism showed similar functional impact on GSCs as ADAR1 disruption. These findings reveal RNA editing links ganglioside catabolism to GSC self-renewal and stemness, exposing a potential vulnerability of GBM for therapeutic intervention.

Authors

Li Jiang, Yajing Hao, Changwei Shao, Qiulian Wu, Briana C. Prager, Ryan C. Gimple, Gabriele Sulli, Leo J.K. Kim, Guoxin Zhang, Zhixin Qiu, Zhe Zhu, Xiang-Dong Fu, Jeremy N. Rich

Lysosomal exocytosis of HSP70 stimulates monocytic BMP6 expression in Sjögren’s syndrome

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Abstract

BMP6 is a central cytokine in the induction of Sjögren's syndrome (SS)-associated secretory hypofunction. However, the upstream initiation leading to the production of this cytokine in SS is unknown. In this study, RNA in situ hybridization on salivary gland sections taken from SS patients indicated monocytic lineage cells as a cellular source of BMP6. RNA sequencing data from human salivary glands suggested TLR4 signaling was an upstream regulator of BMP6, which was confirmed by in vitro cell assays and single-cell transcriptomics of human PBMCs. Further investigation showed HSP70 was an endogenous natural TLR4 ligand that stimulated BMP6 expression in SS. Release of HSP70 from epithelial cells could be triggered by overexpression of lysosome-associated membrane protein 3 (LAMP3), a protein also associated with SS in several transcriptome studies. In vitro studies supported HSP70 was released as a result of lysosomal exocytosis initiated by LAMP3 expression, and reverse transcription PCR on RNA from minor salivary glands of SS patients confirmed a positive correlation between BMP6 and LAMP3 expression. BMP6 expression could be experimentally induced in mice by overexpression of LAMP3, which developed an SS-like phenotype. The newly identified LAMP3/HSP70/BMP6 axis provided an etiological model for SS gland dysfunction and autoimmunity.

Authors

Ying-Qian Mo, Hiroyuki Nakamura, Tsutomu Tanaka, Toshio Odani, Paola Perez, Youngmi Ji, Benjamin N. French, Thomas J.F. Pranzatelli, Drew G. Michael, Hongen Yin, Susan S. Chow, Maryam Khalaj, Sandra A. Afione, Changyu Zheng, Fabiola Reis Oliveira, Ana Carolina F. Motta, Alfredo Ribeiro-Silva, Eduardo M. Rocha, Cuong Q. Nguyen, Masayuki Noguchi, Tatsuya Atsumi, Blake M. Warner, John A. Chiorini