Cellular & Molecular Biology Letters最新文献

{"title":"Chemokines and chemokine receptors in metabolic dysfunction-associated steatohepatitis: pathogenic mechanisms and clinical implications.","authors":"Min Yin, Yan Zhang, Shanshan Liu, Xia Li","doi":"10.1186/s11658-026-00921-z","DOIUrl":"10.1186/s11658-026-00921-z","url":null,"abstract":"<p><p>Metabolic dysfunction-associated steatohepatitis (MASH), an advanced stage of metabolic dysfunction-associated steatotic liver disease (MASLD), is characterized by persistent hepatic inflammation and fibrosis and frequently progresses to cirrhosis or hepatocellular carcinoma. Chemokines and their receptors, which drive disease progression and complications by orchestrating immune cell recruitment, inflammatory responses, and fibrotic processes, are central to the pathophysiology of MASH. Emerging evidence also underscores their functions as active metabolic integrators, reciprocally linking systemic insulin resistance to hepatic inflammation. This review aims to elucidate the pathogenic contributions of key chemokines such as chemokine (C–C motif) ligand (CCL)2, CCL5, CCL20, and chemokine (C–X–C motif) ligand (CXCL)10 in MASH by assessing their dual potential as therapeutic targets and non-invasive biomarkers for early detection. We also survey the current landscape of chemokine-directed therapies to critically evaluate both their efficacy and limitations. Although early clinical trials targeting chemokine pathways have yielded mixed outcomes, emerging research underscores the complexity of chemokine signaling and highlights multiple opportunities for stage-tailored and sex-specific interventions. Therefore, a deeper understanding of chemokine function in MASH holds considerable promise for facilitating the development of targeted, multidimensional treatment strategies, paving the way for personalized management of this progressive liver disorder.</p>","PeriodicalId":9688,"journal":{"name":"Cellular & Molecular Biology Letters","volume":" ","pages":""},"PeriodicalIF":12.2,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13281621/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147763443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DDX17-mediated raptor-dependent mTORC1 activation links autophagy inhibition and metabolic compensation in HCC development.","authors":"Chaoxiang Lv, Na Luo, Chunli Wei, Qiqi Zhang, Kan Guo, Xia Jiang, Xiuhua Cao, Maghsoudloo Mazaher, Ali ElFar, Junjiang Fu","doi":"10.1186/s11658-026-00923-x","DOIUrl":"10.1186/s11658-026-00923-x","url":null,"abstract":"<p><p>Hepatocellular carcinoma (HCC) is a highly heterogeneous malignancy with an increasing global incidence and mortality. Dysregulated gene expression drives uncontrolled proliferation and metastasis, contributing to poor patient survival despite therapeutic advances. The DEAD-box RNA helicase DDX17 has been implicated in tumorigenesis, but its functional role and underlying mechanisms in HCC remain incompletely defined. Here, we found that DDX17 drives HCC tumorigenesis via a novel mechanism involving direct binding to Raptor, a core component of the mTORC1 complex, thereby activating mTORC1 signaling and inhibiting autophagy, as evidenced by reduced autophagosome formation and a decreased LC3-II/LC3-I ratio. Moreover, DDX17 unwinds the RNA G-quadruplex (rG4) structure in the Raptor 3′ untranslated region (3′ UTR), enhancing its translation and establishing Raptor as an rG4-dependent oncogenic target. Combined DDX17 knockdown and rapamycin treatment synergistically suppressed proliferation and induced autophagy. Additionally, DDX17 inhibition reshaped tumor cell metabolism by decreasing extracellular acidification and promoting lipid droplet accumulation following autophagy induction, highlighting its role in metabolic adaptation. These findings suggest that DDX17 promotes HCC progression by unwinding the rG4 motif in Raptor mRNA to enhance translation, activating mTORC1 signaling, and suppressing autophagy. Hence, co-targeting DDX17 and mTORC1 produces strong synergistic antitumor effects, revealing a promising therapeutic strategy for HCC.</p>","PeriodicalId":9688,"journal":{"name":"Cellular & Molecular Biology Letters","volume":" ","pages":""},"PeriodicalIF":12.2,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13273986/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147763438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LUCAT1 drives arecoline-induced head and neck cancer progression via STAT1-mediated transcriptional regulation.","authors":"Hung-Han Huang, Guo-Rung You, Joseph T Chang, Ann-Joy Cheng","doi":"10.1186/s11658-026-00925-9","DOIUrl":"10.1186/s11658-026-00925-9","url":null,"abstract":"<p><p>BACKGROUND: Areca nut chewing is a major environmental risk factor for head and neck cancer (HNC), particularly in Southeast Asia. However, the molecular mechanisms linking areca nut exposure to malignant progression remain poorly understood. Long noncoding RNAs (lncRNAs) have emerged as critical regulators of oncogenesis, but their role in areca nut-associated HNC remains unexplored. METHODS: We performed functional assays, transcriptomic profiling, and bioinformatics analyses to investigate the role of the lncRNA LUCAT1 in arecoline-treated HNC cells. Cell motility, epithelial–mesenchymal transition (EMT), reactive oxygen species (ROS) levels, and therapeutic resistance were assessed following LUCAT1 knockdown or overexpression. We identified upstream regulators of LUCAT1 through promoter analysis, transcription factor knockdown, and pharmacological inhibition. RESULTS: LUCAT1 expression was significantly upregulated by arecoline exposure and promoted cell motility, EMT, ROS clearance, and resistance to radiotherapy and chemotherapy. Knockdown of LUCAT1 reversed these malignant phenotypes and suppressed antioxidant enzyme expression, partly through modulation of the p38 MAPK pathway. Transcriptomic and promoter analyses identified STAT1 as a key transcription factor activated by arecoline via muscarinic acetylcholine receptor (mAChR) signaling. Functional rescue experiments confirmed that LUCAT1 acts downstream of STAT1 to sustain arecoline-induced tumor aggressiveness. CONCLUSIONS: Our findings define a novel mAChR–STAT1–LUCAT1 regulatory axis that mediates areca nut-induced malignant progression in HNC. This study not only reveals a critical molecular pathway linking environmental carcinogen exposure to oncogenic transcriptional reprogramming but also highlights LUCAT1 as a promising target for therapeutic intervention in high-risk patients with HNC. </p>","PeriodicalId":9688,"journal":{"name":"Cellular & Molecular Biology Letters","volume":" ","pages":""},"PeriodicalIF":12.2,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13281458/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147763463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ENTPD3 as a novel regulator of endometrial receptivity: suppressing EMT via the ATP-P2Y2 axis in patients with recurrent implantation failure.","authors":"Dan Mo, Zhonghong Zeng, Yongjin Luo, Wenhong Ma, Kai-Lun Hu, Xunsi Qin, Mingmei Lin, Hongjuan Niu, Xin Sui, Yang Yu, Ping Zhou, Yihua Yang, Rong Li","doi":"10.1186/s11658-026-00927-7","DOIUrl":"10.1186/s11658-026-00927-7","url":null,"abstract":"<p><strong>Background: </strong>Recurrent implantation failure (RIF) remains a major challenge in assisted reproductive technology and is primarily attributed to impaired endometrial receptivity. Despite its clinical significance, the precise mechanisms underlying RIF remain inadequately understood.</p><p><strong>Methods: </strong>Single-cell RNA sequencing (scRNA-seq) was performed on endometrial samples from patients with RIF and healthy controls during the secretory phase using the 10X Genomics Chromium platform. The expression and localization of ectonucleoside triphosphate diphosphohydrolase 3 (ENTPD3) in the window of implantation (WOI) in the endometrium were examined using real-time quantitative polymerase chain reaction (RT-qPCR), western blotting, and immunohistochemistry (IHC). A mouse model with ENTPD3 overexpression was utilized to assess embryo implantation in vivo, and an in vitro blastocyst adhesion assay was performed to evaluate endometrial receptivity. Additionally, Ishikawa cells were transduced with an ENTPD3 recombinant adenovirus to explore the underlying molecular mechanisms.</p><p><strong>Results: </strong>ENTPD3 expression was significantly upregulated in the endometria of patients with RIF during the WOI, and its apical surface localization in endometrial epithelial cells was confirmed by single-cell data and IHC. Functional studies demonstrated that ENTPD3 overexpression impaired endometrial receptivity by suppressing epithelial-mesenchymal transition (EMT). In vivo, ENTPD3 overexpression markedly reduced endometrial receptivity and inhibited embryo implantation in mice. Consistently, in vitro assays revealed that ENTPD3 overexpression diminished blastocyst adhesion to endometrial epithelial cells. Mechanistically, ENTPD3 hydrolyzes ATP, thereby suppressing EMT via the P2Y2 signaling pathway and ultimately disrupting endometrial receptivity.</p><p><strong>Conclusions: </strong>Dysregulated ENTPD3 expression contributes to RIF pathogenesis by impairing endometrial receptivity through ATP hydrolysis-mediated suppression of EMT via P2Y2 signaling. These findings highlight ENTPD3 as a potential therapeutic target for improving implantation success in affected patients.</p>","PeriodicalId":9688,"journal":{"name":"Cellular & Molecular Biology Letters","volume":" ","pages":""},"PeriodicalIF":12.2,"publicationDate":"2026-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13560200/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147763410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Endothelial JAML inhibits inflammation and atherosclerosis through TRIM25-mediated STAT1 ubiquitination.","authors":"Qingmei Han, Fei Xue, Jingwei Li, Zhenguo Wu, Chenghu Guo, Yujie Zhang, Xiao Wu, Jie Yan, Dachuan Guo, Xiaohan Zou, Wencheng Zhang, Meng Zhang, Cheng Zhang, Jianmin Yang","doi":"10.1186/s11658-026-00924-w","DOIUrl":"10.1186/s11658-026-00924-w","url":null,"abstract":"<p><strong>Background: </strong>Atherosclerosis is a chronic inflammatory disease initiated by endothelial dysfunction. Junctional adhesion molecule-like protein (JAML) is known to regulate inflammatory responses; however, its function in vascular endothelial cells and atherosclerosis remains unclear. This study aimed to investigate the function of endothelial JAML in atherosclerosis and to uncover the molecular mechanisms involved.</p><p><strong>Methods: </strong>We generated mice with specific deletion of JAML in endothelial cells and fed them a high-fat diet to induce atherosclerosis, then assessed plaque formation in the aortic root and entire aorta. In parallel, endothelial cells were treated with tumor necrosis factor alpha, and the effects of increasing or silencing JAML on adhesion molecule expression were evaluated, with protein interactions analyzed by co-immunoprecipitation and immunoblotting.</p><p><strong>Results: </strong>JAML exhibited downregulation in endothelial cells within both atherosclerotic lesions and cultured cells subjected to inflammatory stimuli. In mice, the loss of JAML resulted in exacerbated atherosclerotic progression, characterized by larger plaque formation, increased vascular inflammation, and increased macrophage infiltration. Conversely, overexpression of JAML attenuated the expression of adhesion molecules. Mechanistically, JAML was found to promote the degradation of signal transducer and activator of transcription 1 (STAT1) by facilitating its interaction with the E3 ubiquitin ligase tripartite motif-containing 25. This interaction led to ubiquitin-mediated proteolysis of STAT1, independent of alterations in its gene expression levels.</p><p><strong>Conclusions: </strong>These findings suggest that endothelial JAML holds significant promise as a novel therapeutic target for the prevention and intervention of atherosclerosis.</p>","PeriodicalId":9688,"journal":{"name":"Cellular & Molecular Biology Letters","volume":" ","pages":""},"PeriodicalIF":12.2,"publicationDate":"2026-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13281548/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147716316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High-temperature ssBP-LAMP breaks the barrier of nonspecific amplification and unlocks the full potential of LAMP diagnostics.","authors":"Rita S Simões, Pedro Bule, Carlos M G A Fontes, João S Teodoro","doi":"10.1186/s11658-026-00926-8","DOIUrl":"10.1186/s11658-026-00926-8","url":null,"abstract":"<p><p>BACKGROUND: Loop-mediated isothermal amplification (LAMP) is a highly attractive nucleic acid detection method for decentralized molecular diagnostics, but its broader adoption has been limited by unpredictable nonspecific amplification (NSA). Here, we dissect the fundamental determinants of LAMP specificity and present a new high-temperature ssBP-LAMP technique to suppress NSA without compromising assay sensitivity or speed. METHODS: Ubiquitous bioinformatic tools for prediction and design of primer sets and their characteristics were employed to generate a panel of 21 primer sets targeting diverse bacterial, viral, fungal, and human targets. Fluorometric ssBP-LAMP was implemented with a series of coordinated modifications, from increased temperature (only possible owing to a novel, engineered thermostable strand displacement Bst polymerase enzyme) to fine-tuning of additives and auxiliary enzymes. Finally, proof-of-concept validation using both fluorometric and colorimetric approaches for ssBP-LAMP was performed, and their resistance to common inhibitors of molecular diagnostics was evaluated. RESULTS: We show for the first time that primer design alone is insufficient to ensure specificity, and bioinformatic predictions are insufficient predictors of efficiency and, more importantly, of specificity, even when using elevated reaction temperatures. This suggests that NSA frequently originates during the thermal ramp-up phase, before the assay reaches its operational temperature. To address this, we employed a thermolabile single-stranded DNA-binding protein (ssBP) from bacteriophage T7, which transiently sequesters primers during temperature ramp-up. When combined with conventional LAMP primers and elevated assay temperatures (≥ 68 °C), ssBP consistently suppressed NSA across all tested targets. This approach translated directly to both liquid and lyophilized master mixes, enabling highly specific ssBP-LAMP detection by real-time fluorescence and colorimetry. These formulations retained robust sensitivity (down to 10–100 copies/reaction for real-time detection), eliminated false positives, and exhibited tolerance to clinically relevant inhibitors such as plasma, hemoglobin, saliva, and urine, especially in real-time fluorescence detection. CONCLUSIONS: Together, the results establish high-temperature ssBP-LAMP as a rapid (< 15 min), specific, inhibitor-tolerant, and highly adaptable molecular diagnostic technology that overcomes key limitations of conventional LAMP while achieving analytical performance comparable to qPCR, with broad relevance for both clinical and point-of-care testing. </p>","PeriodicalId":9688,"journal":{"name":"Cellular & Molecular Biology Letters","volume":" ","pages":""},"PeriodicalIF":12.2,"publicationDate":"2026-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13281569/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147697652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of the cGAS/STING pathway in skeletal muscle regeneration: modulation of inflammation, macrophage polarization, and oxidative stress.","authors":"Xiaoguang Liu, Hao Wang, Miaomiao Xu, Huan Wang, Haozhe Wang, Wenjun Fang, Mengqian Li, Jiongxing Huang, Huiguo Wang, Yang Yu, Lin Zhu","doi":"10.1186/s11658-026-00908-w","DOIUrl":"10.1186/s11658-026-00908-w","url":null,"abstract":"<p><p>BACKGROUND: Skeletal muscle regeneration is essential for restoring muscle structure and function following injury. This process is influenced by various signaling pathways. Recent studies suggest that cGAS/STING signaling, which is known for its role in innate immunity, may also play a crucial role in tissue regeneration. This study investigated the regulatory role of the cGAS/STING pathway in skeletal muscle regeneration. METHODS: Skeletal muscle injury was induced via intramuscular injection of cardiotoxin (CTX) into the tibialis anterior (TA) muscle of mice. Genetic knockout models of cGAS and STING, as well as treatment with a STING agonist (DMXAA), were used to explore the role of the pathway in muscle regeneration. Histological analysis, flow cytometry, RNA extraction, and gene expression analysis were performed to evaluate muscle tissue morphology, macrophage infiltration, and the expression of inflammatory and oxidative stress markers. RESULTS: STING expression was significantly increased following injury. Treatment with a STING agonist impaired muscle regeneration, characterized by reduced muscle fiber dimensions, elevated pro-inflammatory macrophage infiltration, and increased oxidative stress. In contrast, cGAS or STING knockout enhanced muscle regeneration and promoted the accumulation of anti-inflammatory macrophages. CONCLUSIONS: The cGAS/STING pathway plays a critical role in skeletal muscle regeneration by influencing inflammation, macrophage polarization, and oxidative stress. </p>","PeriodicalId":9688,"journal":{"name":"Cellular & Molecular Biology Letters","volume":" ","pages":""},"PeriodicalIF":12.2,"publicationDate":"2026-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13281308/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147670734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NK-cell-derived exosomes exert antitumor potency via miR-140/XYLT1/HSPG2 axis.","authors":"Dingru Li, Zerui Chen, Herong Liang, Qiang Li, Xiaofan Mao, Beiying Zhang, Weiquan Gu, Ye Xiao, Xing-Dong Xiong, Dan Zhou, Yuhua Deng, Mengyun Cai","doi":"10.1186/s11658-026-00914-y","DOIUrl":"10.1186/s11658-026-00914-y","url":null,"abstract":"<p><p>Non-small cell lung cancer (NSCLC) remains a leading cause of global mortality, necessitating novel therapies. This study investigated the therapeutic role of natural killer cell-derived exosomes (NK-Exo), whose antitumor mechanisms are incompletely understood. Exosomes were isolated from interleukin (IL)-2-independent NK-92MI cells via differential ultracentrifugation and characterized by nanoparticle tracking, electron microscopy, and western blotting. They exhibited cup-shaped morphology (50–150 nm), expressed CD81/TSG101, and demonstrated selective cytotoxicity against tumor cells (A549, A375) but not nontumor cells (293 T) in vitro; this effect was corroborated in patient-derived lung organoids. Small RNA sequencing revealed miR-140-3p as highly enriched in NK-Exo, and its expression correlated with improved survival in patients with NSCLC. Functional validation showed that overexpressing miR-140-3p enhanced NK-Exo cytotoxicity and directly inhibited cancer cell migration and invasion, whereas inhibiting miR-140-3p promoted tumor growth. Mechanistically, miR-140-3p directly targeted xylosyltransferase 1 (XYLT1), as confirmed by dual-luciferase assay, leading to reduced levels of heparan sulfate proteoglycan 2 (HSPG2). Knockdown of XYLT1 phenocopied the tumor-suppressive effects of miR-140-3p, while supplementation with heparan sulfate reversed them. In a Lewis lung carcinoma mouse model, intratumoral delivery of NK-Exo, miR-140-3p mimic, or XYLT1 Small interfering RNA (siRNA) significantly inhibited tumor growth and alleviated splenomegaly. In conclusion, NK-Exo deliver miR-140-3p to suppress tumors via the novel miR-140-3p/XYLT1/HSPG2 axis, presenting a promising therapeutic strategy for cancer.</p>","PeriodicalId":9688,"journal":{"name":"Cellular & Molecular Biology Letters","volume":" ","pages":""},"PeriodicalIF":12.2,"publicationDate":"2026-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13281326/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147662307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Restoration of lysosomal membrane integrity in cell models of Pompe disease depends on fatty acid synthase and its product palmitic acid.","authors":"Edouard Le Guillou, Arianna Segaloni, Alexis Gadault, Catia Oliveira Dias, Nathaniel F Henneman, Min Su, Ivan Nemazanyy, Nesrine Hifdi, Valérie Nivet-Antoine, Michael Laemmerhofer, Karim Hnia, Catherine Caillaud, Ganna Panasyuk","doi":"10.1186/s11658-026-00897-w","DOIUrl":"10.1186/s11658-026-00897-w","url":null,"abstract":"<p><p>BACKGROUND: Lysosomal storage disorders (LSDs) are rare inherited diseases caused by mutations in genes encoding lysosomal proteins, leading to substrate accumulation and lysosomal dysfunction. Whether this build-up compromises lysosomal membrane integrity remains an open question. In this study, we aimed to investigate the presence of lysosomal membrane damage in LSD cells and to identify mechanisms that could reveal potential strategies for improvement of lysosomal function. METHODS: Primary skin fibroblasts from patients with LSDs were used to evaluate lysosomal integrity and function. Lysosomal immunopurification enabled lipidomic and proteomic profiling, complemented by viral transduction for targeted protein expression at lysosomal membranes. Pharmacologic and metabolite treatments were applied in loss-of-function and rescue analyses. Microscopy-based approaches were used to assess lysosomal activity, membrane damage, and integrity. As a complementary model, we employed conditional mouse embryonic fibroblasts (MEFs) lacking class 3 phosphoinositide 3-kinase (PI3K-3), which exhibit lysosomal dysfunction and autophagy defects characteristic of LSDs. RESULTS: In Pompe disease, caused by mutations in the acid alpha-glucosidase gene, glycogen accumulation aggravates persistent lysosomal membrane damage. Moreover, using loss- and gain-of-function models of PI3K-3, we showed that its product, phosphoinositide-3-phosphate (PI3P), was essential for preserving lysosomal membrane integrity. Notably, Pompe patient fibroblasts exhibited chronic lysosomal damage, marked by increased galectin-3 (GAL-3) recruitment and reduced levels of lysosome-associated PI3K-3. Targeted restoration of PI3K-3 at lysosomal membranes rescued this defect and stabilized membrane integrity. Proteomic analyses following genetic or pharmacologic inhibition of PI3K-3 revealed a striking downregulation of fatty acid metabolism, including depletion of fatty acid synthase (FASN). We further demonstrated that PI3K-3 and FASN functionally interacted to maintain lysosomal integrity in Pompe cells. Supplementation with the FASN product palmitate reproduced the protective effect of PI3K-3 targeting, enhancing lysosomal proteolysis and restoring autophagic flux. Importantly, palmitate treatment also improved lysosomal function in fibroblasts from patients with Gaucher disease and type 2 neuronal ceroid lipofuscinosis, extending the relevance of this mechanism across LSDs. CONCLUSIONS: These findings in cell models of LSDs uncover a link between PI3K-3, fatty acid metabolism, and lysosomal membrane integrity. They provide a basis for future in vivo validation of PI3K-3 activation and metabolic modulation as adjuvant treatments to improve lysosomal function in LSDs. </p>","PeriodicalId":9688,"journal":{"name":"Cellular & Molecular Biology Letters","volume":" ","pages":""},"PeriodicalIF":12.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13270713/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147644003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hedgehog pathway activity downstream of Smoothened is regulated specifically by basal ciliary PKA.","authors":"Hongyu Zhang, Shujing Chen, Zhuoya Huang, Jin Ben, Yanling Wei, Guangxin Chen, Changxin Wu, Haibo Xie, Philip W Ingham, Zhonghua Zhao","doi":"10.1186/s11658-026-00915-x","DOIUrl":"10.1186/s11658-026-00915-x","url":null,"abstract":"<p><p>BACKGROUND: Effectors of the vertebrate Hedgehog (HH) signaling pathway are organized within primary cilia (PC). Protein kinase A (PKA), a ubiquitously distributed kinase in most cells, functions as a specific negative regulator of the HH pathway. Its functional specificity in the HH pathway has been suggested to be controlled by cyclic adenosine monophosphate (cAMP) in PC. However, the regulation of PKA and its roles in PC remain unclear, partly owing to the lack of observations regarding PKA localization in PC during the resting state of HH signaling, as well as conflicting reports on the dynamic changes in ciliary cAMP levels and HH pathway activity. Here, we clarify that PKA with basal activity in PC specifically regulates the HH pathway and confirm that Smoothened (SMO)-mediated HH pathway activation may not be fully dependent on its inhibition of ciliary PKA activity. METHODS: To investigate the role of PKA during HH pathway, we have developed an improved ciliary-localized Förster resonance energy transfer (FRET)-based A-kinase activity probe (Nphp3N-AKAR2-CR) for real-time monitoring of ciliary PKA activity in both cultured cells and living embryos. Additionally, by leveraging a highly efficient ciliary targeting peptide (Nphp3N), we specifically delivered PKA variants to either PC or cytoplasm, thereby dissecting the regulatory roles of PKA in the HH pathway across different subcellular compartments. Furthermore, we performed constitutively active SMO variant (SMOA1)–forskolin (FSK) titration assays to validate the dose-dependent relationship underlying SMO-mediated inhibition of PKA. RESULTS: Basal ciliary PKA activity in cells was detected by this probe, despite the absence of observable PKA catalytic subunits in PC. Only ciliary-targeted PKA can modulate the HH pathway, even when PC integrity is disrupted. Notably, ciliary PKA activity is barely changed by either inhibition or activation of the HH pathway at the level of SMO. Furthermore, even low concentrations of FSK efficiently inhibit the HH pathway in the presence of SMOA1. CONCLUSIONS: A basal level of PKA localized in PC but not cytoplasm specifically regulates HH signal transduction, and SMO-mediated activation of the HH pathway may not be solely attributed to the direct regulation of ciliary PKA activity. </p>","PeriodicalId":9688,"journal":{"name":"Cellular & Molecular Biology Letters","volume":" ","pages":""},"PeriodicalIF":12.2,"publicationDate":"2026-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13281347/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147643988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}