Abstract
Obesity is a major risk factor for chronic kidney disease. Time-restricted feeding (TRF) shows promise to reduce kidney inflammation in chronic kidney disease. We hypothesized that TRF blunts kidney fibrosis in obese mice by mitigating T cell inflammation. We used a diet-induced obese mouse model fed a high-fat diet (DIO; 45% fat) ad libitum for 18 weeks followed by 2 weeks of TRF or ad libitum high-fat feeding. We found that TRF reversed kidney fibrosis as well as reduced kidney CD8+ T cells in DIO mice. Our study also reveals that DIO mice had increased kidney CD8+ T cell infiltration from the small intestine that was blunted with TRF. Furthermore, anti-CD8 intervention in DIO showed reduced kidney fibrosis and damage compared with anti-IgG–treated DIO mice. Single-cell RNA-seq data reveal that DIO increased, while TRF reduced, the frequency of a specific cluster of CD8+ T cells that featured high expression of exhaustion/activation genes. Spatial analyses showed DIO mice had significant infiltration of PD-1+CD8+ T cells near CD31+ endothelial cells that was diminished by TRF. In conclusion, this study shows that TRF reversed kidney fibrosis through reducing CD8+ T cell infiltration in obese mice.
Authors
Claudia J. Edell, John D. Erickson, Xiaofen Liu, Savannah C. Walker, Jackson Colson, Michael Heim, Pranav Nagila, Kyle H. Moore, Keri M. Kemp, Kelly Hyndman, Selene Meza-Perez, Troy D. Randall, Annye P. Bennett, Anna G. Sorace, Yu-Hua Dean Fang, David M. Pollock, Carmen De Miguel, Julienne L. Carstens, Jennifer S. Pollock
Abstract
Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), is the most common coinfection in people living with HIV-1. This coinfection is associated with accelerated HIV-1 disease progression and reduced survival. However, the immunological and virological mechanisms driving this progression are not completely understood. To address this knowledge gap, using pleural effusion samples from people living with HIV-1 and TB, we investigated how the HIV-1 genetic landscape and the anti–HIV-1 immune response are impacted by a TB-associated microenvironment. Our results revealed an enrichment of genetically intact HIV-1 and impaired CD8+ T cell–mediated antiviral response at this site of HIV-1/Mtb coinfection. Moreover, efficient CD8+ T cell activation was inhibited by lipids present in the TB-associated pleural effusion. These findings indicate that this immune microenvironment induced by TB promotes the persistence of cells infected with replication-competent HIV-1 by creating a niche of reduced antiviral immune pressure, potentially contributing to the worsened clinical outcomes observed in people living with HIV-1 and TB.
Authors
Samantha Cronin, Jennifer Simpson, Andrea Pereyra-Casanova, Yuchen Li, Josefina Marín-Rojas, Freja A. Warner van Dijk, Katie Fisher, Daniel J. Buffa, Hafsa Rana, Zoï Vahlas, Joaquina Barros, Mariano Maio, Thomas R. O’Neil, Kirstie M. Bertram, Eunok Lee, Najla Nasr, Andrew N. Harman, Gabriela Turk, Maria Florencia Quiroga, Anthony D. Kelleher, Christel Vérollet, Luciana Balboa, Sarah Palmer, Gabriel Duette
Abstract
Menin is a scaffolding protein that interacts with context-specific partners to regulate gene expression. In rearranged mixed-lineage leukemia, Menin-MLL interactions drive leukemogenesis and Menin inhibitors have been FDA approved for these cancers. We previously reported that Menin promotes oncogenic phenotypes in Ewing sarcoma (EwS). Here, we sought to define EwS-specific functions of Menin and determine if Menin inhibitors could be therapeutically leveraged for these tumors. Genetic KO of Menin had no effect on EwS cell proliferation in vitro, but metastatic potential of Menin-depleted cells in vivo was impaired. Transcriptional profiling of Menin-KO cells in vitro showed reproducible downregulation of MYC signature genes and upregulation of developmental programs. Conversely, transcriptional rewiring of developmental genes and restoration of MYC target gene expression were evident in tumors that arose from Menin-KO cells. Exposing EwS cells to the Menin inhibitor VTP50469 (revumenib) inhibited expression of MYC targets, and coimmunoprecipitation studies detected Menin-MYC interactions that were partially disrupted by the drug. Metastatic colonization of disseminated EwS cells in vivo was significantly inhibited in mice fed VTP50469 chow. Together these findings implicate Menin as a mediator of EwS metastasis and suggest that Menin inhibitors warrant investigation as novel therapeutics for patients with high-risk disease.
Authors
Katherine A. Braun, Nicolas M. Garcia, Mohamed A. Ahmed, Darleen S. Tu, Stephanie I. Walter, Emma D. Wrenn, Megan E.B. Dean, Neerja Katiyar, Elizabeth R. Lawlor
Abstract
Wnt signaling drives tumorigenesis in multiple cancers, in part through complex interactions with other oncogenic pathways including the MAPK cascade. In Wnt-addicted cancers, pharmacological and genetic inhibition of Wnt signaling activates multiple RTKs, increases ERK phosphorylation, and induces MAPK target gene expression, but the specific RTKs responsible for this MAPK hyperactivation are not known. Here, we performed phosphotyrosine-targeted mass spectrometry, which revealed robust phosphorylation of EPHA2 and EGFR upon Wnt inhibition. Unexpectedly, we found that in xenografts, EPHA2 suppresses EGFR and ERK activation. Most notably, the increased ERK phosphorylation observed in EPHA2-KO tumors is transcriptionally inert, as there is no concomitant increase in MAPK target gene expression until concomitant Wnt inhibition. This suggests a Wnt-activated transcriptional repressor such as GATA3 that gates MAPK signaling in Wnt-high cancers. Although Wnt-high KRAS-mutant cancers are resistant to erlotinib alone, adding a Wnt inhibitor mitigates this resistance. Additionally, loss of EPHA2 enhances these cancers’ sensitivity to both erlotinib and Wnt inhibitors. Our studies therefore identify therapeutic vulnerabilities in Wnt-high tumors, even within traditionally EGFR inhibitor-resistant, RAS-mutant contexts.
Authors
Shawn R. Wadia, Changyuan Hu, Siddhi Patnaik, Shreya Sridharan, Roger J. Daly, David M. Virshup, Babita Madan
Abstract
Noise-induced hearing loss (NIHL) is a major public health problem caused by damage to cochlear hair cells, synapses, and spiral ganglion neurons (SGNs). Since effective treatments are lacking, we investigated cellular stress responses induced by moderate and loud noise in a mouse model of cochlear synaptopathy. RNA-seq and spatial transcriptomics revealed that noise exposure elicited a robust but transient upregulation of endoplasmic reticulum chaperones and proteasome subunits in SGNs and their supporting cells. To target this response, we administered TRC051384, a small-molecule activator of the heat shock transcription factor Hsf1, prior to noise exposure. TRC051384 crossed the blood-labyrinth barrier and reached the cochlea, induced heat shock protein gene expression, and restored ubiquitin-proteasome function in SGNs. Notably, TRC051384 treatment enhanced auditory brainstem response threshold recovery, preserved Wave I amplitudes, and maintained ribbon synapse density. Together with the existing literature, these findings identify proteotoxic stress in SGNs as a contributor to noise-induced hearing loss and support pharmacological activation of HSF1 as a promising therapeutic strategy.
Authors
Jintao Yu, Miguel A. Ramirez, Yi-Zhi Wang, Seby Edassery, Maxwell Shramuk, SangEun Yeom, Casey Jiaxi Li, Yuvraj Joshi, Mary Ann Cheatham, Mark A. Rutherford, Leah J. Welty, Jeffrey N. Savas
Abstract
Prediabetes is associated with increased production of triglyceride-rich lipoproteins (TRLs), cardiovascular disease (CVD), and hepatic steatosis, which is linked to increased plasma levels of soluble TREM2 (sTREM2), the shed domain of TREM2 (triggering receptor expressed on myeloid cells 2). Whether and how TREM2 shedding contributes to elevated TRLs is unknown. By complementary analyses of individuals with prediabetes and hepatic steatosis and preclinical models, we show that plasma sTREM2 levels correlate positively with plasma apolipoprotein C3 (APOC3), an apolipoprotein that slows TRL catabolism and predicts CVD risk. Individuals with prediabetes and hepatic steatosis had higher plasma concentrations of APOC3-rich TRLs 35 to 60 nm in diameter than healthy controls. Mouse models of prediabetes with hepatic steatosis revealed that the increased plasma concentrations of sTREM2, APOC3, and TRLs were due to activation of macrophage ADAM17, a TREM2 sheddase. Preserving macrophage full-length TREM2 protected against the elevated plasma APOC3, sTREM2, dyslipidemia, and atherosclerosis, whereas TREM2 deficiency increased APOC3, TRLs, and atherosclerosis. Mechanistically, full-length TREM2 mediates macrophage TRL uptake, preventing excessive hepatic APOC3-rich TRL release and atherosclerosis. Our findings identify macrophage TREM2 shedding as an upstream contributor to the elevated TRLs in hepatic steatosis, providing a mechanistic link between hepatic steatosis and CVD risk in prediabetes.
Authors
Jingjing Tang, Jenny E. Kanter, Baohai Shao, Masami Shimizu-Albergine, Farah Kramer, Ah Reum Khang, Jason Luo, Huaqing Zheng, Alan Tran, Jocelyn Cervantes, Jeremy M. Frey, Mauricio D. Dorfman, Cheng-Chieh Hsu, Laura J. den Hartigh, Tomas Vaisar, Brandon S.J. Davies, Adam E. Mullick, George N. Ioannou, Gordon I. Smith, Samuel Klein, Nicholas O. Davidson, Karin E. Bornfeldt
Abstract
Persistent monocyte activation contributes to HIV-associated neurocognitive disorders (HAND), yet biomarkers that predict neurocognitive impairment before and after antiretroviral therapy (ART) remain incompletely defined. We evaluated monocyte subsets and activation markers in participants from the SEARCH007 cohort before ART initiation and at 6 and 12 months following treatment. Increased frequencies of CD14+CD16+ monocytes and elevated CD163 expression were associated with worsening neurocognitive performance and HAND severity. Plasma soluble CD163 levels increased with neurocognitive impairment and correlated with plasma HIV RNA levels, while CCR2 expression was associated with a composite neuropsychological performance Z-score (NPZglobal). Notably, CD169 expression was elevated across all monocyte subsets and demonstrated a stepwise increase with worsening neurocognitive impairment. Although ART reduced overall monocyte activation, elevated CD169 expression persisted in some individuals despite virologic suppression. Bayesian kernel machine regression and random forest analyses identified CD169 expression as one of the strongest predictors of cognitive impairment, surpassing plasma viral load, CD4+ T cell count, and several established monocyte activation markers. These findings identify monocyte CD169 expression as a biomarker of neurocognitive dysfunction before and during the first year of ART and support further investigation of its role in HAND pathogenesis.
Authors
Hai Duc Nguyen, Andrew K. Ding-Su, Caroline Soulas, Tricia H. Burdo, Patrick Autissier, Pasiri Sithinamsuwan, Nitiya Chomchey, Jintanat Ananworanich, Victor Valcour, Silvia Ratto-Kim, Woong-Ki Kim, Kenneth C. Williams
Abstract
Fractures heal by rapid formation of mineralized callus, a process requiring periosteal cell proliferation and differentiation. Our objective was to dissect the contribution of proliferating osteoblast-lineage cells to fracture callus formation. First, mice expressing thymidine kinase (TK) in 3.6Col1a1-lineage cells were treated with ganciclovir (GCV) to ablate proliferating osteolineage cells for 5 or 10 days. Immunostaining demonstrated that this approach specifically depleted TK+ proliferating cells in the bony regions of the callus, while sparing other proliferating cells. Single-cell RNA-seq of callus cells revealed that GCV-treated Col1-TK mice had fewer osteoblasts and chondrocytes than controls, with more myofibroblasts and immune cells, consistent with fibrous nonunion. In controls, 15%–30% of callus cells expressing the early osteoblast marker Osterix (Osx, Sp7) and the late marker osteocalcin (Ocn, Bglap) were in the cell cycle. Next, we targeted proliferating osteolineage cells at different stages of differentiation by crossing Osx-CreERT2, Ocn-Cre, and Dmp1-CreERT2 mice with ROSA-TK mice. Following fracture, each Cre ROSA-TK mouse line exhibited decreased callus bone volume and a shift from callus bone to fibrous tissue. Therefore, during fracture repair, proliferation of callus cells at early and mature stages of osteoblast differentiation is critical to the formation of a mineralized callus that is essential for healing.
Authors
Nicole R. Gould, Andre F. Coello, Jennifer A. McKenzie, Mariam Obaji, Tiandao Li, Katherine R. Hixon, Leyi Chen, Kristen Barwick, Tiffany Lee, Bo Zhang, David Ornitz, Matthew J. Silva
Abstract
Vascular plasticity is a crucial biological asset enabling our bodies to rapidly adapt to infections and acute inflammation. However, repeated insults during chronic disease can result in these vascular adaptations becoming irreversible, thereby driving disease progression and fibrosis. This study aimed to understand if phenotypic changes in endothelial cell (EC) identity could be indicative of progressive fibrosis and thereby offer diagnostic and therapeutic opportunities for patients with metabolic dysfunction–associated steatotic liver disease (MASLD). We integrated high-resolution imaging and proteomic and transcriptomic analysis, which collectively highlighted a central role for endothelial-mesenchymal transition–induced (EndMT-induced) EC plasticity in the derivation of fibrosis-associated EC (FAEC). We demonstrated that: (a) full-spectrum flow cytometry can provide new opportunities to categorize and phenotype EC subpopulations; (b) 2 distinct EndMT-derived FAEC subpopulations expanded during fibrogenesis (THY1.2+ICAM1+ and TAGLN+MCAM+ EC) that displayed unique immunomodulatory and metabolic phenotypes; (c) TAGLN+ FAEC are a conserved, profibrotic cell type that arose at early stages of MASLD; and (d) increased hepatic expression of TAGLN was significantly associated with detrimental patient outcomes at all stages of liver disease. This study paves the way for the development of FAEC-specific diagnostic and therapeutic approaches to tackle progressive fibrotic disease.
Authors
Christina Gkantsinikoudi, Joshua P. Dignam, Raju Kumar, Elliot Jokl, Meenakshi Rana, Wenhao Li, Maryna Samus, Stephanie Landi, Varinder S. Athwal, Timothy J. Kendall, Antal Rot, Jonathan A. Fallowfield, Karen Piper Hanley, William Alazawi, Neil P. Dufton
Abstract
Autoimmune kidney diseases can cause glomerulonephritis and tubulointerstitial nephritis, which if unresolved, lead to progressive glomerulosclerosis and tubulointerstitial fibrosis. The IL-1 receptor (IL-1R1) is known to have divergent and cell-specific effects in kidney injury. We hypothesized that IL-1R1 would dampen pro-inflammatory activation of myeloid cells such that deletion of myeloid cell IL-1R1 would exacerbate autoimmune nephritis. Mice with myeloid cell–specific deletion of IL-1R1 (LysMCre+/Il1r1fl/fl, hereafter MKO) and littermate controls (LysMCre–/Il1r1fl/fl, MWT) were subjected to nephrotoxic serum (NTS) nephritis. MKO mice demonstrated worsened glomerular and tubular injury as indicated by increased albuminuria, glomerular injury scores, and kidney mRNA levels of kidney injury molecule 1 (KIM-1) (Havcr1) and neutrophil gelatinase-associated lipocalin (NGAL/Lcn2). We further found that myeloid IL-1R1 deficiency resulted in increased myeloid cell ER stress and expression of the heterodimeric cytokine Ebi3/Il27a (IL-27). IL-27 then induced increased type I IFN expression by kidney endothelial cells. In turn, anti–IL-27 limited type I IFN expression in endothelial cells and NTS nephritis, and anti-IFNAR1 therapy ameliorated glomerular and tubular injury in MKO mice. Thus, we demonstrated a myeloid cell/endothelial cell immunoregulatory axis whereby myeloid IL-1R1 activity constrained endothelial type I IFN generation to limit chronic kidney damage.
Authors
Yanting Chen, Yu Li, Jiafa Ren, Chia-Chun Wu, Xiaohan Lu, Achintya Inumarty, Steven D. Crowley, Jamie R. Privratsky
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