Cell biology
Abstract
Following acute kidney injury (AKI), a substantial subset of patients experiences an irreversible progression to chronic kidney disease (CKD), yet the molecular determinants governing this maladaptive transition remain elusive, and effective clinical interventions are lacking. Here, we identify lactate as a key metabolic determinant orchestrating the transition from AKI to CKD. Analysis of the UK Biobank cohort reveals that elevated circulating lactate independently predicts CKD development in AKI patients and correlates with fibrotic progression. Using murine ischemia-reperfusion injury models, we demonstrate that lactate drives sustained renal damage through post-translational lactylation of the RNA helicase DDX18. Mechanistically, p300-mediated lactylation of DDX18 at lysine 116 disrupts its nucleolar retention, causing redistribution to the nucleoplasm where it acquires enhanced binding affinity for CD44 mRNA. This subcellular relocalization stabilizes CD44 mRNA through altered RNA-protein interactions, thereby amplifying fibrotic signaling pathways. Therapeutically, we developed a kidney-targeted, cell-penetrating peptide that specifically inhibits DDX18 K116 lactylation, effectively attenuating fibrotic progression in injured kidneys. Our findings establish protein lactylation as a regulatory mechanism governing RNA helicase nucleolar localization and subsequent control of mRNA stability, revealing a potential therapeutic target for interrupting fibrotic processes in chronic kidney disease.
Authors
Lijun Dong, Jingwen Xie, Mengyuan Tao, Shuai Liu, Yueyang Lu, Tianxing Wu, Jian Geng, Qingyun Chen, Xiaoshan Zhao, Jianbo Zhao, Jia Zhou, Honghao Hou, Jun Ai, Tao Tao, Daming Zuo
Abstract
Aneuploidy is a hallmark of cancer often associated with inferior prognosis. Copy number gains of chromosome 8 (chr8) are recurrent in multiple cancers, including breast, prostate, colorectal cancers, and sarcomas such as malignant peripheral nerve sheath tumors (MPNSTs). MPNSTs are aggressive, hard-to-treat sarcomas frequently linked to the Neurofibromatosis type 1 (NF1) cancer predisposition syndrome. To investigate the role of chr8 gain in MPNST pathogenesis, we performed a CRISPR knockout screen and identified 58 essential genes on chr8, including PTK2, which encodes focal adhesion kinase (FAK). We evaluated FAK as a therapeutic target and tested small-molecule FAK inhibitors (FAKi) alone or combined with RAF/MEK inhibitors (RAF/MEKi), a class of agents relevant to NF1-deficient tumors with ERK pathway hyperactivation. Both pharmacological and genetic inhibition of FAK reduced MPNST cell proliferation in vitro and tumor growth in vivo. Combined FAKi and RAF/MEKi treatment further suppressed phosphorylation of FAK, STAT3, and AKT while increasing cleaved caspase-3 and PARP-1, indicating enhanced apoptosis. In MPNST patient-derived xenograft (PDX) models, combination therapy significantly reduced tumor growth, showing superior efficacy, particularly in chr8 gain MPNST-PDX. These results support FAK/RAF/MEK co-targeting as a promising therapeutic strategy for chr8 gain MPNST and related tumors.
Authors
Guangfeng Wang, Dana C. Borcherding, Jiawan Wang, Xiaochun Zhang, Liuzhan Yang, Gorkem Oztosun, James J. Sears, Kangwen Xiao, Belinda B. Garana, Mark I. Zoberi, Aaron U. Bektas, Jeffrey J. Szymanski, Richa Rathore, Silvia Coma, Jonathan A. Pachter, Sara J.C. Gosline, Christine A. Pratilas, Angela C. Hirbe
Abstract
Hereditary Hemorrhagic Telangiectasia type 2 (HHT2), caused by mutations in ACVRL1 ( also known as ALK1), is characterized by brain arteriovenous malformations (bAVMs), abnormal artery–vein connections for which treatment options remain limited. Despite evidence of endothelial cell (EC) heterogeneity, its role in bAVM pathogenesis remains poorly defined. Using endothelial-specific inducible Alk1 knockout mice (Alk1iECKO) and regionally resolved single-cell RNA sequencing, we show that loss of ALK1 signaling induces bAVMs predominantly in the perineural vascular plexus (PNVP). This process is driven by the emergence of a KIT+ angiogenic EC population with human AVM-like transcriptional features, including tip-cell markers and activation of PI3K and KRAS signaling pathways. Cross-species analyses and validation in human samples demonstrate that KIT expression is conserved in endothelial cells from both sporadic and HHT2 brain AVMs. Drug repurposing analysis identified KIT as a top actionable target, and we show that Kit is directly repressed by BMP9–ALK1–SMAD4 signaling. Pharmacological inhibition of KIT reduced angiogenic reprogramming and vascular malformations in vivo without affecting normal vasculature. These findings identify a pathogenic angiogenic EC state and position KIT signaling as a therapeutically actionable pathway in brain AVMs.
Authors
Elise Drapé, Lauranne Carrier, Gael Cagnone, Atik R.M. Fuad, Mathilde Bizou, Damian A. Sanchez, Typhaine Anquetil, Jack Wang, Halima Drissi Touzani Walali, Adnan Gopinadhan, Patrick Piet van Vliet, Joel P. Howard, Mysha Ibnat, Gregor Andelfinger, Ethan Winkler, Bruno Larrivée, Alexandre Dubrac
Abstract
Hepatocellular carcinoma (HCC) is heterogeneous, and hepatocyte plasticity is linked to poorer patient outcomes. A subset of human HCC harboring Tuberous Sclerosis Complex 1 (TSC1) mutations exhibits more aggressive behavior. TFEB is a master regulator of lysosomal biogenesis and cell fate. We analyzed human normal and HCC tissue arrays for TFEB and CK19 expression, as well as bulk and single-cell RNA-seq datasets from mouse and human HCC, to define TFEB-associated transcriptional programs. We performed biochemical, histological, metabolomic, and transcriptomic analyses in liver-specific Tsc1 knockout (L-Tsc1 KO) and L-Tsc1,Tfeb double KO (DKO) mice. Loss of hepatic Tsc1 led to increased phosphorylation of S6 and 4EBP1, with paradoxical increases in TFEB nuclear translocation and activation. L-Tsc1 KO mice showed increased hepatocyte plasticity, decreased HFN4α, increased YAP1 activation, and spontaneous HCC with increased SOX9 and CK19-positive biliary epithelial cell (BEC)-like cells at 8-12 months. Deletion of Tfeb dampened hepatic metabolic reprogramming and hepatocyte fate changes and inhibited tumor progression in L-Tsc1 KO mice. Increased TFEB activity was associated with increased YAP and SOX9 gene expression and high-grade malignant HCC in humans. These findings indicate that loss of hepatic TSC1 leads to non-canonical TFEB activation, promoting hepatocyte plasticity and tumor heterogeneity associated with high-grade malignancy in both mouse and human HCC.
Authors
Chen Zhang, Xiaojuan Chao, Sha Neisha Williams, Xiaoli Wei, Anthony DiGirolamo, Alisha Bajracharya, Lichun Ma, Ming Huang, Nicholas Dunn, Wanqing Liu, Kaito Ueda, Masayuki Sugimoto, Andrea Ballabio, Hong-Min Ni, Wen-Xing Ding
Abstract
Effective psychotherapeutic interventions for post-traumatic stress disorder (PTSD) rely on fear extinction to suppress maladaptive fear responses, yet their long-term efficacy is limited by high relapse rates. Notably, extinction involves not only fear inhibition but also affective engagement. However, whether and how internal affective components contribute to extinction retrieval and long-term persistence remain unclear. Here, we demonstrate that positive affective experiences arising during extinction govern the long-term persistence of extinction and resistance to spontaneous recovery. We identify a subpopulation of medial prefrontal cortex (mPFC) extinction neurons projecting to supramammillary nucleus glutamatergic (SuMGlu) neurons that encodes positive affective experience during extinction and selectively governs long-term extinction persistence. This ensemble is spatially, anatomically, and transcriptionally distinct from mPFC extinction neurons projecting to zona incerta somatostatin-expressing (ZISST) neurons, which primarily support extinction retrieval. Transcriptomic profiling reveals enrichment of sirtuin 1 (Sirt1) within SuM-projecting extinction ensembles, and bidirectional manipulation of SIRT1 alters extinction relapse vulnerability in a PTSD mouse model. These findings provide a cortical–hypothalamic framework incorporating molecular features that governs the long-term persistence of fear extinction and resistance to relapse through positive affective processes.
Authors
Ze-Jie Lin, Xin-Rong Wu, Ming-Yang Wei, Zheng-Kai Lao, Xiang Lan, Yan-Jiao Wu, Wei-Guang Li, Tian-Le Xu, Li-Na Huang, Xue Gu
Abstract
Authors
Zhichuan Zhu, Yusha Liu, Yu Deng, Zhijun Li, Albert S. Baldwin, Pengda Liu
Abstract
Resistance to CDK4/6 inhibitors (CDK4/6i) combined with endocrine therapy presents a major barrier to improving outcomes in ER+ breast cancer. We identified FADD phosphorylation at Ser194 (phospho-FADD) as a mediator of CDK4/6i resistance in the models examined. Phospho-FADD acted as a pseudosubstrate inhibitor of the APC/C-Cdh1 complex, promoting G1/S transition and bypassing the canonical CDK4/6-Rb-E2F pathway. This CDK4/6-independent pathway was associated with PI3K hyperactivation. Clinical relevance of this bypass pathway was supported by increased phospho-FADD and pAKT in 73% of paired patient biopsies at post-treatment recurrence, while the remaining cases exhibited high baseline phospho-FADD and pAKT with intrinsic non-response. Inhibition of FADD phosphorylation with the CK1α degrader DEG-77, or PI3K inhibition, restored CDK4/6i sensitivity in resistant cells. In CDK4/6i-refractory xenografts, CK1α degradation combined with CDK4/6i resulted in profound tumor regressions and increased progression-free survival compared with either single agent, including complete tumor regressions in 92% of tumors. These findings support CK1α-mediated FADD phosphorylation as a targetable resistance mechanism in a subset of CDK4/6i-resistant ER+/HER2– breast cancer.
Authors
Sahezeel Awadia, Elizabeth K. Ziemke, Nicole M. Curnutt, Emily Kirk, Julianne Thomas, Anna Zimmerman, Maya J. Mileski, Sundaresh Ram, Reine Abou Zeidane, Craig Galban, Christina M. Woo, Corey W. Speers, Judith Leopold, Alnawaz Rehemtulla
Abstract
When massive hepatic necrosis (MHN)-associated acute liver failure (ALF) occurs following severe damage, liver progenitor cells (LPCs) exit quiescence and enter differentiation programs during which they acquire hepatocyte-like functions. To date, how LPCs maintain quiescence under physiological conditions and orchestrate activation following MHN remains largely unknown. Here, we elucidate an essential role of TGF-β in regulating LPC quiescence and activation. Spatial transcriptomics and single-cell sequencing revealed that LPCs receive multiple signals, particularly TGF-β, HGF, and EGF from surrounding hepatic stellate cells and macrophages in patients and zebrafish with MHN-induced ALF. Physiologically, TGF-β inhibits LPC proliferation by blocking the G1-S phase transition, an effect that was reversed by Smad7 overexpression in a murine injury model. Intriguingly, extensive LPC proliferation was observed in ALF patients despite strong TGF-β-p-SMAD signaling. Immunostaining further revealed concurrent activation of HGF/MET, EGF/EGFR, and downstream STAT3/ERK pathways in LPCs. In vitro, HGF or EGF overcame TGF-β-mediated growth arrest and promoted LPC proliferation. Beyond acting as a mitogen, HGF additionally induced hepatocyte gene programs (e.g., Hnf4a, Hnf1a) in LPCs. Strikingly, TGF-β signaling was required for HGF-dependent hepatocyte gene induction, indicating a dual role in restraining LPC proliferation and promoting functional maturation. These findings position TGF-β as a context-dependent determinant of LPC activation and lineage specification during ALF.
Authors
Chenhao Tong, Tao Lin, Han Wang, Luyao Jiang, Xiaodong Yuan, Wenwu Luo, Minghan Zhou, Carolina De La Torre, Hui Liu, Chen Shao, Seddik Hammad, Hui Gao, Jiarong Xie, Lei Xu, Roman Liebe, Zuguang Gu, Matthias P. Ebert, Huiguo Ding, Steven Dooley, Hong-Lei Weng
Abstract
Gut microbiota-derived trimethylamine N-oxide (TMAO) plays a role in the pathogenesis of cardiovascular disease. The role of TMAO in the pathogenesis of atrial fibrillation (AF) remains uncertain. TMAO levels were quantified in plasma from serial subjects undergoing elective cardiac catheterizations (N=5090) and shown to independently associate with prevalent AF following adjustment for risk factors (TMAO adjusted odds ratio 1.7 [95% confidence interval 1.3-2.1]; P<0.01). Human cAMP response element modulator isoform IbΔC-X transgenic mice (CREM-IbΔC-X), a spontaneous mouse model of AF, supplemented with a TMAO diet developed AF sooner. C57BL/6J mice on and off a TMAO had more inducible AF via a transesophageal pacing study compared to chow controls. Dietary choline supplementation increased circulating TMAO levels and significantly accelerated AF onset in CREM-IbΔC-X mice (P<0.01). Iodomethylcholine (IMC), the gut microbial CutC/D inhibitor that suppresses choline→TMA(O) metabolic transformation, reduced circulating TMAO levels (P<0.0001) and choline induced AF onset (P<0.01). Cecal metagenomic analyses showed that choline supplementation induced changes in microbial communities associated with AF, while many of these changes were attenuated by IMC. Choline supplementation promoted overall adverse atrial remodeling with left atrial dilation. Optical mapping studies showed that mice supplemented with choline exhibited reduced conduction velocity, shortened action potential duration at 80% repolarization, and decreased wavelength. TMAO inhibits muscarinic receptor 2 resulting in autonomic dysfunction that promotes AF. In summary, the gut microbial metabolite TMAO, independently associated with AF risk in subjects, enhances AF in multiple AF mouse models via autonomic dysfunction, and is a therapeutic target for prevention of AF.
Authors
Selvam Arjunan, Isaiah Pemberton, Xinmin S. Li, Naseer Sangwan, Lydia Akino, Emmanuel Opoku, Dmitriy Verbovetskiy, Ina Nemet, Hyun Su Kim, Haruko Masumiya, Zeneng Wang, Joseph A. Lupica, Melissa Y. Tian, Karis Mao, Deepthi P. Mallela, Maradumane Mohan, Sarah Schumacher, Julie H. Rennison, Sathyamangla Prasad, Kenneth R. Laurita, Vamsi Chodisetty, Mina K. Chung, David R. Van Wagoner, John Barnard, Jonathan D. Smith, Oussama Wazni, Stanley L. Hazen, Robert A. Koeth
Abstract
Neddylation is highly activated in many human cancers and may serve as a therapeutic target for clinical treatment. However, it remains unclear regarding the role of neddylation in tumor angiogenesis. Here, we demonstrate that the neddylation E2 enzyme UBE2M is upregulated in tip cells and is essential for tumor vascular sprouting. We show that UBE2M-mediated neddylation of STAT1 enhances its phosphorylation and promotes the transcription of DLL4. This elevated DLL4 expression in tip cells activates Notch signaling in adjacent stalk cells, thereby maintaining the tip-stalk cell balance and ensuring organized vascular patterning. Consequently, endothelial-specific deletion of UBE2M reduces DLL4 expression, leading to excessive but non-productive sprouting due to uncontrolled tip cell formation and lack of stalk cell support, which ultimately suppresses tumor growth. Importantly, targeting endothelial neddylation potently sensitizes various tumors to anti-VEGF therapy. Together, our findings unveil UBE2M as a key regulator of angiogenic signaling and identify it as a promising anti-angiogenic target in cancer.
Authors
Xinyi Jiang, Jie Zhang, Li Zhou, Zonglin Li, Ningcong Sun, Xian Xu, Jisong Zhang, Yizhou Huang, Xue Zhang, Enguo Chen, Hongqiang Cheng, Yuehai Ke
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ISSN: 0021-9738 (print), 1558-8238 (online)