Journal of Biological Chemistry最新文献_第6页

The ability of SAMHD1-deficient monocytes to trigger the type I IFN response depends on cGAS and mitochondrial DNA samhd1缺陷单核细胞触发I型IFN反应的能力取决于cGAS和线粒体DNA

IF 4.8 2区生物学

Journal of Biological Chemistry Pub Date : 2025-06-26 DOI: 10.1016/j.jbc.2025.110430

Jesse Rabinowitz, Isabelle K. Vila, Charlotte Luchsinger, Cinzia Bertelli, Moritz Schüssler, Clara Taffoni, Bin Cui, Annie Zhi Dai, Mohammad M. Rashid, William J. Cisneros, Daphne Cornish, Juan Redondo, Kathryn A. Jackson-Jones, Lacy M. Simons, Ramon Lorenzo-Redondo, Nadine Laguette, Judd F. Hultquist, Felipe Diaz-Griffero

{"title":"The ability of SAMHD1-deficient monocytes to trigger the type I IFN response depends on cGAS and mitochondrial DNA","authors":"Jesse Rabinowitz, Isabelle K. Vila, Charlotte Luchsinger, Cinzia Bertelli, Moritz Schüssler, Clara Taffoni, Bin Cui, Annie Zhi Dai, Mohammad M. Rashid, William J. Cisneros, Daphne Cornish, Juan Redondo, Kathryn A. Jackson-Jones, Lacy M. Simons, Ramon Lorenzo-Redondo, Nadine Laguette, Judd F. Hultquist, Felipe Diaz-Griffero","doi":"10.1016/j.jbc.2025.110430","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110430","url":null,"abstract":"In humans, mutations in sterile α motif and histidine-aspartate domain–containing protein 1 (<ce:italic>SAMHD1</ce:italic>) lead to the development of a type I interferonopathy known as Aicardi–Goutières syndrome (AGS). AGS can present with a variety of severe phenotypes in patients, and a hallmark of this disease is chronic activation of type I interferon (IFN) signaling. However, the mechanism through which type I IFN signaling is activated in the absence of functional SAMHD1 is not known. Here, we investigated the molecular pathways that lead to type I IFN signaling activation in the absence of SAMHD1. Our investigations revealed that chronic activation of type I IFN signaling in <ce:italic>SAMHD1</ce:italic>-knockout(KO) monocytes is cyclic GMP–AMP synthase (cGAS)-dependent. Analysis of other nucleic acid sensors showed that type I IFN signaling in <ce:italic>SAMHD1</ce:italic>-KO cells is not dependent on melanoma differentiation-associated protein 5 (MDA5) or retinoic acid–inducible gene I (RIG-I). In agreement with our observation that type I IFN signaling is dependent on cGAS, two inhibitors of the cGAS–stimulator of IFN genes pathway, G140 and H151, effectively prevented type I IFN activation in <ce:italic>SAMHD1</ce:italic>-KO monocytes. We also found that type I IFN signaling in <ce:italic>SAMHD1</ce:italic>-KO monocytes is dependent on type I IFN receptor expression. Further exploration revealed mitochondrial malfunction in SAMHD1-KO monocytes that is likely to leak mitochondrial components into the cytoplasm. Overall, our work suggests that genetic knock out of SAMHD1 leads to mitochondrial disfunction, resulting in the presence of mitochondrial DNA in the cytoplasm, which triggers cGAS and the type I IFN response.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"42 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Translation-independent association of mRNAs that encode protomers of the 5-HT2A-mGlu2 receptor complex 编码5-HT2A-mGlu2受体复合物原蛋白的mrna的翻译非依赖性关联

IF 4.8 2区生物学

Journal of Biological Chemistry Pub Date : 2025-06-26 DOI: 10.1016/j.jbc.2025.110427

Somdatta Saha, Javier Gonzalez-Maeso

{"title":"Translation-independent association of mRNAs that encode protomers of the 5-HT2A-mGlu2 receptor complex","authors":"Somdatta Saha, Javier Gonzalez-Maeso","doi":"10.1016/j.jbc.2025.110427","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110427","url":null,"abstract":"G protein-coupled receptors (GPCRs) constitute the largest family of plasma membrane proteins, and regulate cell signaling by activating heterotrimeric G proteins. The serotonin 5-HT<ce:inf loc=\"post\">2A</ce:inf> receptor (5-HT<ce:inf loc=\"post\">2A</ce:inf>R) and the metabotropic glutamate 2 receptor (mGluR2) are GPCRs that play a pivotal role in processes related to perception, memory and mood regulation. These receptors are able to interact to form heteromeric GPCR complexes through direct physical interactions, which modulate the signaling and trafficking properties of both protomers. Co-translational association of mRNAs encoding subunits of heteromeric ion channels has been reported, but whether complex assembly of GPCRs occurs during translation remains unknown. Here, our <ce:italic>in vitro</ce:italic> data reveal evidence of co-translational modulation in <ce:italic>5-HT</ce:italic><ce:inf loc=\"post\"><ce:italic>2A</ce:italic></ce:inf><ce:italic>R</ce:italic> and <ce:italic>mGluR2</ce:italic> mRNAs following siRNA-mediated knockdown. Interestingly, immunoprecipitation of either 5-HT<ce:inf loc=\"post\">2A</ce:inf>R or mGluR2, using an antibody targeting epitope tags at their N-terminus, results in detection of both transcripts associated with ribonucleoprotein complexes containing RPS24. Additionally, we demonstrate that the mRNA transcripts of <ce:italic>5-HT</ce:italic><ce:inf loc=\"post\"><ce:italic>2A</ce:italic></ce:inf><ce:italic>R</ce:italic> and <ce:italic>mGluR2</ce:italic> associate autonomously of their respective encoded proteins. Validation of this translation-independent association is extended <ce:italic>ex vivo</ce:italic> using mouse frontal cortex samples. Together, these findings provide mechanistic insights into the co-translational assembly of GPCR heteromeric complexes in mammalian cells, unraveling regulatory processes governing protein-protein interactions and complex formation.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"62 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Dual roles of fibroblast-epithelial crosstalk in acute and chronic lung injury 成纤维细胞-上皮串扰在急性和慢性肺损伤中的双重作用

IF 4.8 2区生物学

Journal of Biological Chemistry Pub Date : 2025-06-26 DOI: 10.1016/j.jbc.2025.110408

Marie-Therese Bammert, Ines Kollak, Jan Hoffmann, Eva Peter, Meshal Ansari, Holger Schlüter, Jun Li, Alexandre R. Campos, Coralie Viollet, Florian Gantner, Muriel Lizé, Matthew J. Thomas, Huy Q. Le

{"title":"Dual roles of fibroblast-epithelial crosstalk in acute and chronic lung injury","authors":"Marie-Therese Bammert, Ines Kollak, Jan Hoffmann, Eva Peter, Meshal Ansari, Holger Schlüter, Jun Li, Alexandre R. Campos, Coralie Viollet, Florian Gantner, Muriel Lizé, Matthew J. Thomas, Huy Q. Le","doi":"10.1016/j.jbc.2025.110408","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110408","url":null,"abstract":"Dysfunctional interactions between fibroblasts and epithelial cells contribute to the progression of chronic lung diseases, including idiopathic pulmonary fibrosis (IPF). In this study, we developed an air-liquid interface coculture model of human-derived small airway epithelial cells and lung fibroblasts to investigate intercellular dynamics during disease progression. Our findings showed that chronic epithelial damage initiates a bidirectional fibrotic cascade between the epithelium and lung fibroblasts, exacerbating epithelial injury and the release of pro-fibrotic mediators. Conversely, our transcriptomic and proteomic analyses revealed that, in the context of acute epithelial injury, a protective signaling environment emerges that mitigates further damage. By delineating secreted regulators involved in these beneficial responses, we identified pentraxin 3 (PTX3) as a leading antifibrotic candidate. Supplementation with PTX3 in chronically injured epithelial cells alleviated the pro-fibrotic phenotype and preserved epithelial barrier integrity through modulation of the AKT/claudin-2 axis. These insights highlight key differences of acute and chronic lung injuries and underscore the importance of the complex interplay between epithelial cells and fibroblasts in lung injury and repair.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"9 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Genetic variants linked to neurodevelopmental disorders within the β3-β4 loop of the TRIO PH2 domain release autoinhibition of GEF2 activity. 与TRIO PH2结构域β3-β4环内神经发育障碍相关的遗传变异释放GEF2活性的自抑制。

IF 4.8 2区生物学

Journal of Biological Chemistry Pub Date : 2025-06-26 DOI: 10.1016/j.jbc.2025.110429

Melissa G. Carrizales, Andrew D. Boulton, Anthony J. Koleske

{"title":"Genetic variants linked to neurodevelopmental disorders within the β3-β4 loop of the TRIO PH2 domain release autoinhibition of GEF2 activity.","authors":"Melissa G. Carrizales, Andrew D. Boulton, Anthony J. Koleske","doi":"10.1016/j.jbc.2025.110429","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110429","url":null,"abstract":"The TRIO protein contains two guanine exchange factor (GEF) domains, GEF1 and GEF2, which coordinate cytoskeletal rearrangements by activating Rho family GTPases. Rare variants that impact TRIO GEF1 function are associated with autism spectrum disorder, developmental delay, and intellectual disability, but variants are also found throughout the gene. GEF1 promotes GTP exchange on Rac1 and RhoG, while GEF2 activates RhoA. Although GEF1 and GEF2 share a common architecture, the pleckstrin homology (PH) domain in TRIO GEF1 (PH1) assists its activity, while the PH domain in GEF2 (PH2) inhibits its activation of RhoA. A series of single point variants in the unique β3-β4 loop of TRIO PH2 has been identified in patients with neurodevelopmental disorders (NDDs), but how they impact TRIO GEF2 activity is not known. Using an in vitro fluorescence-based assay to assess GEF2 exchange activity on RhoA, we demonstrate that variants within the β3-β4 loop relieve GEF2 autoinhibition. Activation of RhoA inhibits neurite outgrowth in Neuro-2A (N2A) cells. GEF2 expression in N2A cells significantly reduces neurite outgrowth, and expression of the G2211E activating GEF2 variant enhances this effect. Together, our findings reveal key interactions and structural constraints for GEF2 autoinhibition and how this mechanism is a target for disruption by NDD-associated variations.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"33 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

NMR-guided Identification of CYP11A1–Adrenodoxin Interactions that Differentially Govern Cholesterol and Vitamin D3 Metabolism 核磁共振引导鉴定cyp11a1 -肾上腺素还毒素相互作用差异控制胆固醇和维生素D3代谢

IF 4.8 2区生物学

Journal of Biological Chemistry Pub Date : 2025-06-26 DOI: 10.1016/j.jbc.2025.110428

Janie E. McGlohon, Jacob Logothetis, D. Fernando Estrada

{"title":"NMR-guided Identification of CYP11A1–Adrenodoxin Interactions that Differentially Govern Cholesterol and Vitamin D3 Metabolism","authors":"Janie E. McGlohon, Jacob Logothetis, D. Fernando Estrada","doi":"10.1016/j.jbc.2025.110428","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110428","url":null,"abstract":"Cytochromes P450 (CYPs) are heme-containing enzymes essential for a range of biochemical processes, including steroidogenesis and vitamin D metabolism. Among mitochondrial CYPs, CYP11A1 catalyzes both cholesterol side-chain cleavage, producing pregnenolone, and hydroxylation of vitamin D3, producing 20(OH)D3. Previous studies have shown that substrates can modulate CYP11A1 protein–protein interactions with the redox partner Adrenodoxin (Adx), but the structural basis of the substrate-specific modulation towards Adx is not known. In this study, we investigated whether there exist contact(s) between CYP11A1 and Adx that are differentially influenced by cholesterol and vitamin D3, and whether these substrate-specific contacts are important for CYP11A1 monooxygenation of vitamin D3 or side chain cleavage of cholesterol. Utilizing 2D NMR spectroscopy in combination with solubilization of substrates with hydroxypropyl-β-cyclodextrin, we were able to isolate M77 of Adx α helix-3 as a substrate-specific contact towards CYP11A1. Site-directed mutagenesis of Adx M77 into M77L and M77S and mutagenesis of the corresponding CYP11A1 contact (W418A) revealed differential effects towards cholesterol and vitamin D3 metabolism. These data suggest that CYP11A1 protein–protein interactions with Adx are uniquely driven by substrate specificity and shed light on potential substrate-sensitive recognition in other mitochondrial CYPs. These findings are further discussed in the context of a modeled interaction between CYP11A1 and the reduced (functional) form of Adx in which Adx M77–CYP11A1 W418 is the driving constraint. Moreover, this study describes an NMR-based protocol that is broadly applicable towards the investigation of other substrate-sensitive CYP–redox partner interactions.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":"9 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144515226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Loss of integrin alpha7-mediated signaling induces a dendritic cell-like phenotype in macrophages cultured on laminin-211/221 isoforms. 在层粘连蛋白211/221亚型培养的巨噬细胞中，整合素α 7介导的信号通路缺失可诱导树突状细胞样表型。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-06-25 DOI: 10.1016/j.jbc.2025.110419

Nagako Yoshiba, Tomoki Maekawa, Kiyotoshi Sekiguchi, Masaru Kaku, Kridtapat Sirisereephap, Meircurius Surboyo, Yurie Sato-Yamada, Andrea Rosenkranz, Akihiro Hosoya, Naoto Ohkura, Yoshito Kakihara, Takeyasu Maeda, George Hajishengallis, Kenji Izumi, Kunihiko Yoshiba

{"title":"Loss of integrin alpha7-mediated signaling induces a dendritic cell-like phenotype in macrophages cultured on laminin-211/221 isoforms.","authors":"Nagako Yoshiba, Tomoki Maekawa, Kiyotoshi Sekiguchi, Masaru Kaku, Kridtapat Sirisereephap, Meircurius Surboyo, Yurie Sato-Yamada, Andrea Rosenkranz, Akihiro Hosoya, Naoto Ohkura, Yoshito Kakihara, Takeyasu Maeda, George Hajishengallis, Kenji Izumi, Kunihiko Yoshiba","doi":"10.1016/j.jbc.2025.110419","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110419","url":null,"abstract":"Laminin comprises α/β/γ subunits and performs tissue-specific functions that control cellular behavior. Laminin-α2 chains are highly expressed in neural components such as glial and Schwann cells and in muscles. Macrophages play important roles in tissue homeostasis and repair, and laminins affect macrophage dynamics. Integrin α7, a transmembrane receptor crucial for regulating cell-matrix interactions, has a high affinity for laminin-α2, but its function in macrophages remains unknown. Here, we find that loss of integrin α7 signaling induces a dendritic cell (DC)-like phenotype in THP-1-derived macrophages and in primary monocytes-derived macrophages (MDMs) induced by granulocyte macrophage colony-stimulating factor (GM-CSF) cultured on laminin-α2 chains. Functional blocking of integrin α7 induced dendritic processes of THP-1-derived macrophages. Gene expression analysis revealed DC markers and costimulatory molecules, and coculture experiments demonstrated that the DC-like cells could stimulate T cell proliferation. Functional inhibition of integrin α7 decreased PI3K-p85α levels and activated PI3K, thereby activating AKT. MDMs cultured on laminin α2 chains decreased integrin α7 expression, exhibited dendritic-like morphology, and increased expression of DC markers and costimulatory molecules. These findings suggest that, besides the established influence of cytokine milieu, DC differentiation is regulated by laminin α2/integrin α7-mediated cell adhesion. Integrin α7 has been a therapeutic target in tumors, and antibody-based integrin α7 neutralization can be clinically useful. The results of this study suggest implications for integrin α7 and laminin-α2 chains in DC immunotherapy.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"110419"},"PeriodicalIF":4.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phosphorylation-mediated Regulation of the NADPH-dependent Glutamate Dehydrogenase, SpGdh1, from Schizosaccharomyces pombe. 裂糖酵母nadph依赖性谷氨酸脱氢酶（SpGdh1）磷酸化介导的调控

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-06-25 DOI: 10.1016/j.jbc.2025.110422

Yi-Fan Wang, Takeo Tomita, Ayako Yoshida, Saori Kosono, Makoto Nishiyama

{"title":"Phosphorylation-mediated Regulation of the NADPH-dependent Glutamate Dehydrogenase, SpGdh1, from Schizosaccharomyces pombe.","authors":"Yi-Fan Wang, Takeo Tomita, Ayako Yoshida, Saori Kosono, Makoto Nishiyama","doi":"10.1016/j.jbc.2025.110422","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110422","url":null,"abstract":"Glutamate dehydrogenase from the yeast Schizosaccharomyces pombe (SpGdh1) is a pivotal enzyme that catalyzes the conversion of 2-oxoglutarate and ammonium to glutamate using NADPH as a coenzyme. Although SpGdh1 is phosphorylated at several residues, the impact of phosphorylation on enzyme activity and the underlying molecular mechanisms remain unclear. To elucidate the phosphorylation-mediated regulation of SpGdh1, we determined the crystal structure of SpGdh1 binding 2-iminoglutarate (2-IG) and NADP+. The results of the structural analysis revealed that four serine residues for phosphorylation were located near the active site. Ser252 directly interacted with the 2'-phosphate group of the adenine ribose moiety of NADP+, suggesting that the phosphorylation of Ser252 interfered with NADP+ binding. To confirm this hypothesis, we prepared SpGdh1 phosphorylation-mimic (Ser to Glu) variants of SpGdh1 at these four Ser residues. The results of a kinetic analysis revealed that the replacement of these four residues increased the apparent KmNADP(H) value and decreased catalytic efficiency, kcat/KmNADP(H).In contrast, substitutions decreased the apparent KmNAD(H) value and increased catalytic efficiency, kcat/KmNAD(H). Therefore, the Ser to Glu replacement caused net shifts in the coenzyme specificities (NADPH to NADH and NADP+ to NAD+) of 55- and 2900-fold, respectively. This is the first study to reveal the effects of the phosphorylation of SpGdh1 on its activity.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"110422"},"PeriodicalIF":4.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cathepsin K as a key regulator of myocardial fibrosis in dilated cardiomyopathy and a promising therapeutic target. 组织蛋白酶K作为扩张型心肌病心肌纤维化的关键调节因子和一个有前景的治疗靶点。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-06-25 DOI: 10.1016/j.jbc.2025.110421

Lanlan Ma, Bingjun Lu, Yueqiao Si, Lingyan Dai, Mingyue Tan, Wujian Liu, Dongdong Sun, Jiangcheng Shu, Cong Chen, Qi Xiang, Dingsheng Jiang, Xiang Wei, Wei Eric Wang

{"title":"Cathepsin K as a key regulator of myocardial fibrosis in dilated cardiomyopathy and a promising therapeutic target.","authors":"Lanlan Ma, Bingjun Lu, Yueqiao Si, Lingyan Dai, Mingyue Tan, Wujian Liu, Dongdong Sun, Jiangcheng Shu, Cong Chen, Qi Xiang, Dingsheng Jiang, Xiang Wei, Wei Eric Wang","doi":"10.1016/j.jbc.2025.110421","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110421","url":null,"abstract":"Dilated cardiomyopathy (DCM) is a leading cause of heart failure with a high mortality rate. Cardiac fibrosis plays a critical role in the progression of DCM, yet therapeutic strategies targeting fibrosis remain limited. Therefore, it is essential to investigate the underlying mechanisms of fibrosis in DCM. Our study demonstrates through the integration of weighted gene co-expression network analysis and gene ontology annotation that 35 biological processes, including cytokine production, were significantly associated with fibrosis in DCM. Protein-protein interaction analysis identified 82 crucial genes. The scRNA-seq identified Cathepsin K (CTSK) as primarily expressed in cardiac fibroblasts. Masson's trichrome and immunofluorescence staining revealed that the level of fibrotic tissue in the left ventricle of patients with DCM and the expression of CTSK are higher than those in the normal ventricle. In vitro studies demonstrated that CTSK expression was upregulated in highly proliferative human cardiac fibroblasts (HCFs). PDGF-BB stimulation notably promoted HCF proliferation, an effect that was significantly attenuated by CTSK knockdown. However, CTSK depletion showed no inhibitory impact on TGF-β1-induced transdifferentiation of cardiac fibroblasts into myofibroblasts. Our research indicates that CTSK is a key regulator of myocardial fibrosis in DCM and is a promising therapeutic target.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"110421"},"PeriodicalIF":4.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An anti-CD47 antibody binds to a distinct epitope in a novel metal ion-dependent manner to minimize cross-linking of red blood cells. 一种抗cd47抗体以一种新的金属离子依赖方式结合到一个独特的表位上，以最大限度地减少红细胞的交联。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-06-25 DOI: 10.1016/j.jbc.2025.110420

Xiao Lu, Ziyue Chen, Chunyan Yi, Zhiyang Ling, Jing Ye, Kaijian Chen, Yao Cong, Sonam Wangmo, Shipeng Cheng, Ran Wang, Danyan Zhang, Jiefang Xu, Jichao Yang, Liyan Ma, Qing Duan, Xiaoyu Sun, Jianping Ding, Bing Sun

{"title":"An anti-CD47 antibody binds to a distinct epitope in a novel metal ion-dependent manner to minimize cross-linking of red blood cells.","authors":"Xiao Lu, Ziyue Chen, Chunyan Yi, Zhiyang Ling, Jing Ye, Kaijian Chen, Yao Cong, Sonam Wangmo, Shipeng Cheng, Ran Wang, Danyan Zhang, Jiefang Xu, Jichao Yang, Liyan Ma, Qing Duan, Xiaoyu Sun, Jianping Ding, Bing Sun","doi":"10.1016/j.jbc.2025.110420","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110420","url":null,"abstract":"Cluster of differentiation 47 (CD47) is a widely expressed transmembrane protein that plays a crucial role in immune self-recognition. Cancer cells upregulate CD47 expression to promote immune escape through activating the \"don't eat me\" signal via interactions with signal regulatory protein α (SIRPα) on macrophages. The effectiveness of anti-CD47 antibodies has been demonstrated in multiple tumour models. However, since CD47 is also expressed in human red blood cells (RBCs) and platelets, the clinical application of anti-CD47 antibodies requires careful consideration of blood toxicity. One major obstacle to the clinical application of CD47 antibodies is the haemagglutination caused by RBCs cross-linking. In this study, we generated Hu1C8, a humanized anti-CD47 monoclonal antibody that demonstrated increased selectivity for binding to CD47 on cancer cells and lacked haemagglutination activity. Epitope mapping and the crystal structure of the Hu1C8 Fab-CD47 extracellular domain (ECD) complex revealed that Hu1C8 binds to a distinct epitope of CD47 in a Ca2+-dependent manner. The unique recognition and binding mode allowed Hu1C8 to bind CD47 on RBCs with reduced haemagglutination activity while still maintaining effective antitumour activity. These findings demonstrate a feasible strategy for developing CD47 antibodies with high antitumor activity but low RBC haemagglutination activity. Our study elucidates how epitope-specific antibody influences antibody-induced cell cross-linking, offering innovative strategies for antibody design to either leverage or avoid cell cross-linking effects.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"110420"},"PeriodicalIF":4.0,"publicationDate":"2025-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144512010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Poly(A) Polymerase Star-PAP is Regulated by Stably Associated Phosphoinositide Messengers. 聚(A)聚合酶Star-PAP受稳定相关磷酸肌苷信使调控。

IF 4 2区生物学

Journal of Biological Chemistry Pub Date : 2025-06-24 DOI: 10.1016/j.jbc.2025.110412

Tianmu Wen, Mo Chen, Vincent L Cryns, Richard A Anderson

{"title":"The Poly(A) Polymerase Star-PAP is Regulated by Stably Associated Phosphoinositide Messengers.","authors":"Tianmu Wen, Mo Chen, Vincent L Cryns, Richard A Anderson","doi":"10.1016/j.jbc.2025.110412","DOIUrl":"https://doi.org/10.1016/j.jbc.2025.110412","url":null,"abstract":"Star-PAP is a noncanonical poly(A) polymerase that controls gene expression. Star-PAP was previously reported to bind PIPKI⍺ and its product PI(4,5)P2, which regulate Star-PAP activity and expression of specific genes. Recent studies have revealed a nuclear p53-phosphoinositide signaling pathway in which the phosphatidylinositol (PI) transfer proteins (PITPs) and phosphoinositide kinases/phosphatases bind p53 to sequentially modify p53-linked phosphoinositides and regulate p53 function. Here we demonstrate that multiple phosphoinositides are also coupled to Star-PAP in response to stress. This pathway is initiated by PITP⍺/β binding to Star-PAP, and the Star-PAP-phosphoinositide complexes are sequentially modified by PI4KII⍺, PIPKI⍺, IPMK, and PTEN. The formation of Star-PAP-phosphoinositide complexes enhances the association of the small heat shock proteins HSP27 and ⍺B-crystallin with Star-PAP. Knockdown of the PITPs, PIP kinases, or HSP27 reduces the expression of Star-PAP targets. Our results demonstrate that PITP⍺/β play a key role in the assembly of Star-PAP-phosphoinositide complexes that are sequentially interconverted by PIP kinases/phosphatases and recruit the small heat shock proteins to these complexes to regulate Star-PAP activity in response to stress.","PeriodicalId":15140,"journal":{"name":"Journal of Biological Chemistry","volume":" ","pages":"110412"},"PeriodicalIF":4.0,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144505809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

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