Abstract
Abdominal aortic aneurysm (AAA) lacks effective pharmacological therapies. Here, we investigate transcription factor 7–like 2 (TCF7L2), a genetic locus associated with both thoracic and abdominal aortic aneurysms, to elucidate its role in AAA pathogenesis. Integrating summary data–based Mendelian randomization (SMR) with single-cell RNA sequencing of human and mouse aortae, we identify TCF7L2 as a gene enriched in vascular smooth muscle cells (VSMCs) and causally linked to AAA development. Smooth muscle cell–specific TCF7L2 knockout significantly attenuates AAA formation across 3 distinct murine models (AAA induced by angiotensin II infusion, by β-aminopropionitrile/angiotensin II coadministration, and by elastase), independent of systemic blood pressure or lipid levels. Mechanistic studies reveal that TCF7L2 directly upregulates MMP14 and downregulates TIMP3 expression in vitro and in vivo, driving MMP2-mediated extracellular matrix (ECM) degradation. Concurrently, TCF7L2 represses integrin β1 (ITGB1) expression, reducing VSMC adhesion to the ECM. Collectively, these findings identify TCF7L2 as a key driver of pathological vascular remodeling in AAA, suggesting that targeting TCF7L2 may offer a novel therapeutic strategy for limiting AAA progression.
Authors
Yongjie Deng, Yaozhong Liu, Yang Zhao, Hongyu Liu, Guizhen Zhao, Zhenguo Wang, Xu Zhang, Chao Xue, Wei Huang, Tianqing Zhu, Haocheng Lu, Yanhong Guo, Lin Chang, Ida Surakka, Y. Eugene Chen, Jifeng Zhang
Abstract
Tuberculosis (TB) and HIV coinfection remains a major global health challenge, with limited understanding of how these pathogens affect local immune responses in the lungs. This study is the first to our knowledge to investigate the modulation of IL-21 during LTBI and M. tuberculosis/SIV coinfection in nonhuman primates (NHP). We show that IL-21 expression, predominantly derived from CD4+ T cells, is significantly reduced in lungs of M. tuberculosis/SIV coinfected macaques, especially in the absence of cART. Although cART and cART with 3HP partially restore IL-21–producing CD4+ T cells, levels remain below those in LTBI, indicating ongoing immune impairment. Spatial transcriptomic analysis suggests localized alterations in immune signaling, including differences in STAT1- and STAT3-associated transcriptional profiles and reduced M. tuberculosis–specific IFN-γ responses in coinfected animals. Together, our findings indicate that IL-21–producing CD4+ T cells are selectively and persistently impaired in the lungs during M. tuberculosis/SIV coinfection, despite antimicrobial and antiviral therapy. These results highlight a compartment-specific deficit in immune reconstitution and suggest that IL-21–associated pathways may warrant further investigation as potential targets for host-directed therapeutic strategies.
Authors
Vinay Shivanna, Renee D. Escalona, Colin Chuba, Shashi Prakash Singh, Ahmed A. Moustafa, J. Quincy Brown, Chenyao Xiao, Sangkyu Kim, Edward J. Dick Jr., Smriti Mehra, Mirko Paiardini, Riti Sharan
Abstract
Lipotoxicity associated with metabolic dysfunction–associated steatotic liver disease (MASLD) causes dysregulated fatty acid (FA) and glucose metabolism, inducing cellular energy imbalance, oxidative stress (OS), and hepatocellular injury. IL-10 is altered in MASLD, including increased IL-10 transcripts in peripheral immune cells; however, its role in hepatic responses to lipotoxic stress remains unclear. We evaluated whether IL-10 treatment attenuates lipotoxic injury and MASLD-related phenotypes in vivo and in vitro to reveal MASLD treatment strategies. As MASLD models, mice fed a high-fat diet and in vitro normal human hepatocytes under palmitic acid exposure were treated with IL-10, along with confirmatory experiments in HepG2 cells. We assessed FA and glucose metabolism, OS, and apoptosis with histological changes and mechanisms related to hepatocellular viability/metabolic activity and stress-responsive survival signaling in vitro. IL-10 modulated FA synthesis and β-oxidation, reducing lipid accumulation, and IL-10 altered glucose metabolic pathways, consistent with improved glucose handling under lipotoxic stress. Furthermore, IL-10 reduced OS and cell death markers while enhancing antioxidant responses, consistent with hepatocellular protection. These data suggest that IL-10 attenuates lipotoxic injury by modulating hepatic response pathways, thereby improving MASLD-related phenotypes, and support the potential of IL-10 as a therapeutic target for MASLD.
Authors
Akira Kado, Kazuya Okushin, Takeya Tsutsumi, Toshiyuki Kishida, Kazuhiko Ikeuchi, Hiroshi Yotsuyanagi, Kyoji Moriya, Kazuhiko Koike, Mitsuhiro Fujishiro
Abstract
Extracellular matrix (ECM) disorder was believed to result from fibrosis, but it has recently been recognized that fibrotic ECM initiates a self-reinforcing circuit and contributes to the development of fibrosis. Versican, an ECM component, participates in cell-ECM interaction and ECM regeneration. In pleura, versican is primarily derived from pleural mesothelial cells (PMCs). However, the role and mechanism of versican in pleural fibrosis has remained unknown. In this study, versican and versican-mediated pleural viscoelasticity were found to be elevated in both human and murine pleural fibrotic tissues. Versican knockdown by shRNA prevented increases in viscoelasticity as well as pleural fibrosis. High levels of versican and viscoelasticity promoted mesothelial-mesenchymal transition in PMCs. Mechanistically, increased viscoelasticity induced pleural fibrosis through the CD44/USP10/Smad4 mechanotransduction pathway. In conclusion, these results revealed that excessive versican in fibrotic pleural ECM enhanced ECM viscoelasticity and consequently promoted progression of pleural fibrosis.
Authors
Zi-Heng Jia, Xin-Liang He, Xiao-Lin Cui, Qian Li, Pei-Pei Cheng, Li-Qin Zhao, Shu-Yi Ye, Shi-He Hu, Chen-Yue Lian, He-De Zhang, Li-Mei Liang, Lin-Jie Song, Fan Yu, Liang Xiong, Fei Xiang, Xiaorong Wang, Meng Wang, Xiyong Dai, Hong Ye, Wan-Li Ma
Abstract
Donnai-Barrow syndrome (DBS) arises from loss-of-function (LoF) variants in the endocytic receptor low-density lipoprotein receptor–related protein 2 (LRP2; or megalin) and is characterized by low–molecular weight proteinuria and developmental abnormalities. Urinary proteomics of 9 patients with DBS revealed that the urinary proteome of a DBS patient with the missense variant LRP2 p.C1400R was indistinguishable from that of patients with splice site, nonsense, or frameshift mutations. A CRISPR mouse model of the variant was generated to determine the mechanism of LoF and proteinuria. The mutant LRP2 was expressed and observed to dimerize and localize to the proximal tubule apical membrane. However, both fluid-phase and receptor-mediated endocytosis was impaired in the context of a general perturbation of endocytic flux. Immunofluorescence revealed aberrant endocytic recycling with mislocalized RAB11+ and TFR1+ compartments and enlarged lysosomes. Structural modeling showed that the LRP2 assembly likely tolerates the cysteine-to-arginine substitution at the cell surface, but at endosomal pH the variant introduced steric clashes that may disrupt intramolecular interfaces and disturb receptor recycling. These findings point to the importance of LRP2 recycling for global endocytic flux and offer a blueprint for leveraging patient-specific alleles to dissect proximal tubule function.
Authors
Andrew Beenken, Tian H. Shen, Aryan Ghotra, Hediye Erdjument-Bromage, Jeong Lee, Jared S. Kushner, Rachel E. Sturley, Atlas Khan, Jeffrey R. Arace, Leora Kronenberg, Lucy D. Shen, Gabriel H. Rahmani, Patricia K. Donahoe, Thomas A. Neubert, Frances A. High, Ora A. Weisz, Jonathan Barasch
Abstract
Chronic hyperglycemia induces microvascular complications in patients with type 2 diabetes (T2D), particularly diabetic retinopathy, nephropathy, and neuropathy. We revisited the pancreatic vasculature to reexamine such damage in 3D. Using thick pancreatic tissue slices, we analyzed volumetric intraislet capillary density (vICD) and peri-islet volumetric exocrine capillary density (vECD) as well as interface capillary counts along the islet periphery to quantify vascular integration between the islets and surrounding acinar cells. Contrary to the previous reports, vICD was not homogeneous but highly heterogeneous across the five species studied (human, monkey, pig, ferret, and mouse), especially in smaller islets. vICD became less variable with increasing islet size, converging at approximately 20%. With this foundation of islet vascularization, pancreatic tissues from non-diabetic and T2D subjects consisting of 8 age- and sex-matched pairs (age range of 35–65 years with various duration: 0–15 years) were examined. Strikingly, no significant differences in microvascular density were found; mean vICD and mean vECD were nearly equivalent between the groups. Capillary integration with respect to islet size was comparable. These findings suggest that integrated pancreatic blood flow with robust crosstalk between the endocrine and exocrine pancreas may facilitate microvascular preservation in T2D via local distribution of insulin.
Authors
Alex M. Tollefson, Frank R. Marsico, Manami Hara
Abstract
In metabolic dysfunction–associated steatohepatitis (MASH), liver sinusoidal endothelial cells (LSECs) acquire a proinflammatory phenotype termed lipotoxic endotheliopathy. We previously identified glycogen synthase kinase 3β (GSK3β) as a central signaling hub in LSECs during MASH. To elucidate the molecular mechanisms and functional outcome of lipotoxicity-induced GSK3β activation in LSECs, we utilized endothelial cell–specific Gsk3β-KO (Gsk3βΔEnd) mice fed MASH-inducing diets. Endothelial Gsk3β deletion significantly reduced markers of lipotoxic endotheliopathy, including adhesion molecules and chemokines, alongside liver injury, inflammation, and fibrosis. Immune profiling via flow cytometry and mass cytometry by time of flight (CyTOF) identified decreased hepatic infiltration of proinflammatory myeloid populations, particularly mature DCs in Gsk3βΔEnd mice. In a coculture system, GSK3β in lipotoxic LSECs promoted DCs maturation. Mechanistically, GSK3 inhibition restored lipotoxicity-induced alterations in LSEC mitochondrial morphology and respiration by regulating AMP-activated protein kinase and dynamin-related protein 1. This rescue suppressed chemokine and adhesion molecule expression, thereby limiting immune cell recruitment. Collectively, under lipotoxic stress, GSK3β amplifies mitochondrial dysfunction and inflammatory signaling in LSECs, enhancing myeloid cell homing and DC maturation. Targeting LSEC GSK3β may, therefore, represent a promising therapeutic strategy to mitigate LSEC-driven fibroinflammatory response in human MASH.
Authors
Akitoshi Sano, Qianqian Guo, Khaled Warasnhe, Chady Meroueh, Nantawat Satthawiwat, Asma Hamdi, Ghefar Hmaydoosh, Xin Dai, Usman Yaqoob, Kevin D. Pavelko, Charlene Miciano, Tatiana Kisseleva, Zeba Firdaus, Patrick P. Starlinger, David Pereyra, Enis Kostallari, Petra Hirsova, Davide Povero, Samar H. Ibrahim
Abstract
Cancer-induced bone pain (CIBP) is among the most common and debilitating symptoms in patients with bone metastasis. Current treatments are somewhat effective but have severe side effects. For the future development of safer CIBP treatments, in this study, we sought to investigate the mechanisms whereby the nerve-cancer interaction controls CIBP. We found that c-Kit, a receptor tyrosine kinase, was activated in the dorsal root ganglia (DRG) sensory neurons of mice with CIBP and that c-Kit’s sole ligand, stem cell factor (SCF), was enhanced in the bone marrow with bone metastasis. When DRGs were treated with SCF or conditioned medium from high SCF-expressing cancer cells, in vitro nerve sprouting was enhanced, and this effect was abolished with c-Kit inhibitors. Mice inoculated intrafemorally with cancer cells that had varying levels of SCF expression developed CIBP and enhanced peripheral nerve sprouting in an SCF-dependent manner. Downstream proteomic analysis revealed that SCF upregulated and activated fibroblast growth factor 1 (FGF1) in DRGs. When FGF1 was knocked down in DRGs, SCF-mediated nerve sprouting was prevented. Taken together, our studies demonstrate the importance of the SCF/c-Kit axis in CIBP and nerve sprouting and identify the SCF/c-Kit/FGF1 pathway as a potential therapeutic target for CIBP.
Authors
Kelly F. Contino, Jenna Ollodart, Yang Yu, Sun H. Park, Shunsuke Tsuzuki, Kara Rollins, Tyler M. Heethouse, Joshua Chu, Laiton R. Steele, Takahiro Kimura, Jingyun Lee, Cristina M. Furdui, Lance D. Miller, Fang-Chi Hsu, Yusuke Shiozawa
Abstract
Carriers of germline BRCA1/2 pathogenic variants (gBRCA1/2 PVs) have elevated young-onset breast cancer risk. To define the pretreatment genomic landscapes of young-onset gBRCA-associated breast cancer, we evaluated 136 treatment-naive tumors diagnosed before age 50 in the prospective POSH study and 66 noncarriers from The Cancer Genome Atlas. Using whole-exome sequencing, we analyzed somatic variation, allele-specific loss of heterozygosity (asLOH), homologous recombination deficiency (HRD), and single-base substitution (SBS) signatures. gBRCA1 and gBRCA2 breast cancers had high rates of asLOH but differed significantly in average HRD scores and median SBS composition of signatures SBS1 (aging-associated), SBS18 (ROS-associated), and SBS3 (HRD-associated). Compared with gBRCA2 tumors, gBRCA1 tumors with asLOH were significantly enriched for alterations in hallmark ROS, DNA repair, and epithelial-mesenchymal transition pathways. In ER-positive, HER2-negative tumors from gBRCA1/2 carriers compared with noncarriers, we found significant enrichment of RB1, TP53, FAT1, and MYC single-nucleotide variants, indels, and copy number variants associated with CDK4/6 inhibitor (CDK4/6i) resistance. Together, these findings demonstrate significant differences between gBRCA1- and gBRCA2-associated breast cancers, and preexisting CDK4/6i resistance mechanisms, supporting prospective trials comparing individualized therapy for gBRCA1 versus gBRCA2 carriers and comparing poly(ADP-ribose) polymerase inhibitors versus CDK4/6i for ER-positive gBRCA1/2-associated breast cancer.
Authors
Mwangala P. Akamandisa, Mingyi Xia, Wilson Cheah, Bradley Wubbenhorst, Kurt P. D’Andrea, Mengyao Fan, Jake S. Shilan, Dana Pueschl, Anupma Nayak, Hayley McKenzie, William Tapper, Ellen R. Copson, Ramsey I. Cutress, Susan M. Domchek, Diana M. Eccles, Katherine L. Nathanson
Abstract
Glaucoma is associated with ocular hypertension, and lowering intraocular pressure is the primary objective of current therapies. Recent studies have established a key role for Schlemm’s canal endothelium in this pressure increase and have shown that it has a unique, lymphatic-like hybrid phenotype characterized by expression of the lymphatic transcription factor PROX1. However, the functional importance of this hybrid phenotype in the adult canal remains unclear, as long-term studies have been limited by systemic requirements for lymphatic gene expression and a lack of Schlemm’s canal–specific animal models. Here, we designed and validated a51 strategy using 4OH-tamoxifen-loaded nanocarriers to generate targeted, Schlemm’s canal-52 specific Prox1 knockout mice that specifically lacked lymphatic characteristics in the canal53 endothelium. Within 4 weeks, intraocular pressure was significantly elevated, and ocular hypertension was maintained for at least 24 weeks. Unlike lymphatic vessels, which degenerate following Prox1 deletion, Schlemm’s canal persisted but reverted to a less functional vein-like phenotype with no change in size or morphology. Together, these findings demonstrate the utility of nanocarrier-mediated tamoxifen delivery and establish the importance of the Schlemm’s canal lymphatic-like phenotype in intraocular pressure regulation, providing targets for future glaucoma therapies and a mouse model of adult-onset ocular hypertension.
Authors
Sofia Lara Ochoa, Hoi-Lam Li, Hyeohn Kim, Zihang Yan, Natalia C. Mendonca, Pan Liu, Hyunjoo J. Lee, Michael P. Vincent, Sultan Almunif, Hao F. Zhang, Haiyan Gong, Evan A. Scott, Mark Johnson, Benjamin R. Thomson
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