Abstract
We recently showed that cell surface translocation of the endoplasmic reticulum–resident protein GRP78, when bound by activated α 2-macroglobulin (α2M*), induces pro-fibrotic responses in glomerular mesangial cells in response to high glucose and regulates activation of the pro-fibrotic cytokine transforming growth factor-β1 (TGF-β1), implicating a pathogenic role in glomerulosclerosis. Interstitial fibrosis, largely mediated by proximal tubular epithelial cells (PTEC) and renal fibroblasts, develops later in kidney disease and correlates with functional decline. Here we investigated whether interstitial fibrosis was mediated by cell surface GRP78 (csGRP78)/α2M*. High glucose and TGF-β1 increased csGRP78 and α2M* in PTEC and renal fibroblasts, and their inhibition prevented fibrotic protein production. Interestingly, for TGF-β1, this depended on inhibition of noncanonical signaling through YAP/TAZ, with Smad3 activation unaffected. In vivo, type 1 diabetic Akita mice overexpressing TGF-β1 were treated with either a neutralizing antibody for csGRP78 (C38) or α2M* (Fα2M) or an inhibitory peptide blocking csGRP78/α2M* interaction, and mice with unilateral ureteral obstruction were treated with Fα2M or inhibitory peptide. Consistently, inhibition by antibody or peptide attenuated fibrosis and pro-fibrotic signaling. These findings show an important role for csGRP78/α2M* in mediating tubulointerstitial fibrosis in both diabetic and nondiabetic kidney disease and support their inhibition as a potential antifibrotic therapeutic intervention.
Authors
Jackie Trink, Ifeanyi Kennedy Nmecha, Katrine Pilely, Renzhong Li, Zi Yang, Sydney Kwiecien, Melissa MacDonald, Bo Gao, Mariam A. Mamai, Chao Lu, Urooj F. Bajwa, Nikhil Uppal, James C. Fredenburgh, Masao Kakoki, Salvatore V. Pizzo, Anthony F. Rullo, Matthew B. Lanktree, Jeffrey I. Weitz, Yaseelan Palarasah, Joan C. Krepinsky
Abstract
The transcription factor IKAROS, encoded by IKZF1, is crucial for lymphocyte development and differentiation. Germline heterozygous IKZF1 mutations cause B cell immunodeficiency, but also affect T cells. Patients with IKZF1 haploinsufficiency (HI) or dimerization-defective (DD) variants show reduced naive and increased memory T cells, while dominant-negative (DN) mutations result in the opposite phenotype. Gain-of-function patients display variable patterns. To investigate IKAROS’s role in shaping the human naive/memory T cell phenotype, we performed IKAROS immunomodulation and knockdown experiments and analyzed early T cell development in an artificial thymic organoid (ATO) system using CD34+ cells from patients with representative IKZF1 variants. IKAROS inhibition by lenalidomide or silencing by small hairpin RNA directly altered expression of HNRNPLL, the master regulator of CD45 isoform splicing that defines CD45RA+/naive and CD45RO+/memory phenotypes. In the ATO system, IKAROS-DN precursor cells were blocked at the CD4–CD8–/double-negative stage and retained a CD45RA+ phenotype, whereas IKAROS-HI cells inefficiently reached the CD4+CD8+/double-positive stage and partially transitioned from CD45RA to CD45RO. Analysis of public gene expression data showed high HNRNPLL expression in double-positive thymic cells, beyond the stages affected by IKZF1 DN and HI mutations. Collectively, these findings indicate that IKAROS regulates early and late T cell development by mechanisms, including HNRNPLL modulation.
Authors
Jennifer Stoddard, Hye Sun Kuehn, Ravichandra Tagirasa, Marita Bosticardo, Francesca Pala, Julie E. Niemela, Agustin A. Gil Silva, Kayla Amini, Eduardo Anaya, Mario Framil Seoane, Carolina Bouso, Dimana Dimitrova, Jennifer A. Kanakry, Laia Alsina, Matias Oleastro, Steven M. Holland, Thomas A. Fleisher, Richard L. Wasserman, Luigi D. Notarangelo, Sergio D. Rosenzweig
Abstract
Autoimmunity arises when self-reactive B and T cells target the body’s own tissues, with B cells contributing through antigen presentation as well as production of autoantibodies and proinflammatory cytokines. Genome wide association studies (GWAS) and recent identification of loss-of-function gene variants in individuals with young-onset autoimmunity have highlighted a role for protein tyrosine phosphatase nonreceptor type 2 (PTPN2) in development of autoimmunity. While prior studies have focused on the mechanism of Ptpn2 in T cells and other cell types, its function in B cells has not been explored. To test the B cell–intrinsic roles of Ptpn2, we generated a B cell–specific deletion of Ptpn2 in mice (Mb1-Cre;Ptpn2fl/fl). We found that loss of Ptpn2 in B cells promoted organ inflammation, increased the frequency of age/autoimmune-associated B cells (ABCs) and plasmablasts in the periphery, and increased circulating autoantibodies. Moreover, we found that Ptpn2 acted as a negative regulator of the JAK/STAT and TLR7 pathways in B cells. In line with this, treatment of B cells from Mb1-Cre;Ptpn2fl/fl mice with IFN-γ and TLR7 agonist lead to enhanced differentiation into ABCs. These findings highlight the critical roles of Ptpn2 in B cell function and its potential as a key regulator in preventing B cell associated autoimmunity.
Authors
Bridget N. Alexander, Soojin Kim, Kristen L. Wells, Maya J. Hunter, Kevin P. Toole, Scott M. Wemlinger, Daniel P. Regan, Andrew Getahun, Mia J. Smith
Abstract
The tumor microenvironment plays a key role in cancer progression and therapy resistance, with cancer-associated fibroblasts (CAFs) contributing to desmoplasia, extracellular matrix (ECM) remodeling, and elevated interstitial fluid pressure, all of which hinder drug delivery. We investigated fibroblast activation protein–targeted (FAP-targeted) near-infrared photoimmunotherapy (NIR-PIT) as a strategy to improve drug penetration in CAF-rich tumors. In clinical esophageal cancer samples, FAP expression strongly correlated with increased collagen I, hyaluronic acid, and microvascular collapse. CAF-rich 3D spheroids demonstrated elevated ECM deposition and significantly impaired drug uptake compared with CAF-poor models. FAP-targeted NIR-PIT selectively reduced CAFs, reduced ECM components, and restored drug permeability. In vivo, FAP-targeted NIR-PIT enhanced the accumulation of panitumumab and Abraxane in CAF-rich tumors and improved antitumor efficacy when combined with chemotherapy. These findings highlight FAP-targeted NIR-PIT as a promising therapeutic approach to remodel the tumor stroma and overcome drug resistance in desmoplastic solid tumors.
Authors
Seitaro Nishimura, Kazuhiro Noma, Tasuku Matsumoto, Yasushige Takeda, Tatsuya Takahashi, Hijiri Matsumoto, Kento Kawasaki, Hotaka Kawai, Tomoyoshi Kunitomo, Masaaki Akai, Teruki Kobayashi, Noriyuki Nishiwaki, Hajime Kashima, Takuya Kato, Satoru Kikuchi, Shunsuke Tanabe, Toshiaki Ohara, Hiroshi Tazawa, Yasuhiro Shirakawa, Peter L. Choyke, Hisataka Kobayashi, Toshiyoshi Fujiwara
Abstract
Pulmonary fibrosis (PF) is a pathology associated with interstitial lung diseases (ILDs), including idiopathic pulmonary fibrosis (IPF). Fibrosis promotes continual secretion of extracellular matrix (ECM), producing nonfunctional scar tissue and causing organ failure. This study investigated the tyrosine kinase receptor Ephrin type-B receptor 4 (EphB4) as a mediator of PF. To this end, we generated mice with conditional Col1a2-driven deletion of Ephb4 and used a preclinical mouse model of PF, total and single nuclei RNA (snRNA) sequencing, NanoString, previously published single-cell data, computational analysis, and functional assays of mouse and human healthy control and IPF lung fibroblasts. Col1a2-CreERT–driven Ephb4 deletion, or EphB4 inhibition via NVP-BHG712, markedly protected against bleomycin-induced PF. Total RNA-Seq of fibroblasts isolated from Ephb4-deficient fibrotic mouse lungs exhibited reduced expression of ECM, ER Cargo, and protein trafficking–related genes. NVP-BHG712 reduced expression of these identified genes in mouse lung fibroblasts under fibrotic conditions in vitro. snRNA-Seq of mouse lungs treated with NVP-BHG712 identified transcriptomic changes of ECM genes in specific fibroblast subpopulations. RNA-Seq, computational, and functional assays using mouse and human IPF fibroblasts identified elastin as a key mediator involved in EphB4 signaling. Combined, our data show that EphB4 is a crucial mediator of PF.
Authors
Brian Wu, Starlee S. Lively, Shabana Vohra, Noah Fine, Chiara Pastrello, Anca Maglaviceanu, Osvaldo Espin-Garcia, Evan Pollock-Tahiri, Sayaka Nakamura, Paramvir Kaur, Keemo Delos Santos, Jason S. Rockel, Pratibha Potla, Himanshi Gupta, Poulami Datta, Laura Tang, Jacob Kwon, Akihiro Nakamura, Matthew B. Buechler, Rajiv Gandhi, Jiangping Wu, Boris Hinz, Igor Jurisica, Mohit Kapoor
Abstract
IgA protects the body from invaders in the mucosal sites, but its role in allergic diseases, such as hay fever, is poorly understood. We demonstrate an increased susceptibility to cedar-pollen-induced hay fever associated with increasing pollen penetration into the body in IgA-deficient mice, indicating that IgA prevents pollen invasion in the mucosa. We identified bryostatin 1, an anticarcinogenic protein kinase Cδ (PKCδ) activator, as an IgA/IgE class-switching regulator in B cells. Bryostatin 1 enhanced IgA production through induction of germline transcript α (GLTα) via the PKCδ/MEK/ERK/RUNX1 pathway and suppressed IgE by reducing GLTε through the PKCδ/STAT5/ID2 pathway. Production of Th2 cytokines and eosinophil infiltration in the lungs was also reduced. Furthermore, hay fever alleviation by bryostatin 1 demonstrated diminished symptoms in mice in vivo 3 months subsequent to intranasal administration.
Authors
Naoki Morita, Kohta Yamamoto, Ryutaro Tamano, Peng Gao, Takahiro Nagatake, Takenori Inomata, Tianxiang Huang, Yasuhiro Yamada, Takahiro Adachi, Manabu Sugai, Keiichi I. Nakayama, Hirotatsu Kojima, Reiko Shinkura
Abstract
High-affinity antibody production depends on CD4+ T follicular helper (Tfh) cells. In humans, peripheral blood Tfh cells are heterogenous, as evidenced by differential expression of the chemokine receptors CXCR3 and CCR6, which to date have served to classify 3 subsets, pTfh1, pTfh2, and pTfh17. Although pTfh1 responses dominate during blood-stage Plasmodium infections, a clear association with protective antibody responses remains to be described. We hypothesized that pTfh cells exhibit greater phenotypic and functional heterogeneity than described by CXCR3/CCR6 and that more nuanced pTfh subsets play distinct roles during Plasmodium infection. We mapped pTfh cell heterogeneity in healthy individuals prior to and during controlled human malaria infection (CHMI) using parallel single-cell RNA-Seq and VDJ-Seq. We uncovered 2 pTfh1 subsets or differential phenotypic states, distinguishable by CCR7 expression. Prior to infection, Tfh1-CCR7– cells exhibited higher baseline expression of inflammatory cytokines and genes associated with cytotoxicity. Tfh1-CCR7+ cells had higher germinal center signatures. Indeed, during CHMI, Tfh1-CCR7+, Tfh1-CCR7–, and Tfh2 cells all clonally expanded and became activated. However, only Tfh1-CCR7+ and Tfh2 cells positively associated with protective antibody production. Hence, our data reveal further complexity among human Tfh cells and highlight 2 distinct subsets associated with antibody-mediated immunity to malaria.
Authors
Megan S.F. Soon, Damian A. Oyong, Nicholas L. Dooley, Reena Mukhiya, Zuleima Pava, Dean W. Andrew, Jessica R. Loughland, James S. McCarthy, Jo-Anne Chan, James G. Beeson, Christian R. Engwerda, Ashraful Haque, Michelle J. Boyle
Abstract
Anthracycline chemotherapy, widely used in cancer treatment, poses a significant risk of cardiotoxicity that results in functional decline. Current diagnostic methods poorly predict cardiotoxicity because they do not detect early damage that precedes dysfunction. Positron emission tomography (PET) is well suited to address this need when coupled with suitable imaging biomarkers. We used PET to evaluate cardiac molecular changes in male C57BL/6J mice exposed to doxorubicin (DOX). These mice initially developed cardiac atrophy, experienced functional deficits within 10 weeks of treatment, and developed cardiac fibrosis by 16 weeks. Elevated cardiac uptake of [68Ga]Ga-FAPI-04, a PET tracer targeting fibroblast activation protein α (FAP), was evident by 2 weeks and preceded the onset of functional deficits. Cardiac PET signal correlated with FAP expression and activity as well as other canonical indicators of cardiac remodeling. By contrast, cardiac uptake of [18F]DPA-714 and [18F]MFBG, which target translocator protein 18 kDa and the norepinephrine transporter, respectively, did not differ between the DOX animals and their controls. These findings identify FAP as an early imaging biomarker for DOX-induced cardiac remodeling in males and support the use of FAP PET imaging to detect some cancer patients at risk for treatment-related myocardial damage before cardiac function declines.
Authors
Chul-Hee Lee, Onorina L. Manzo, Luisa Rubinelli, Sebastian E. Carrasco, Sungyun Cho, Thomas M. Jeitner, John Babich, Annarita Di Lorenzo, James M. Kelly
Abstract
Genetic variants in lipid metabolism influence the risk of developing metabolic dysfunction–associated steatotic liver disease (MASLD), cirrhosis, and end-stage liver disease (ESLD). The mechanisms by which these variants drive disease are poorly understood. Because of the PNPLA3-I148M variant’s strong correlation with all stages of the MASLD spectrum and the lack of tractable therapeutic targets, we sought to understand its impact on cellular function and liver metabolism. Primary human hepatocytes (HAHs) and induced pluripotent stem cell–derived (iPSC-derived) hepatocytes (iHeps) from healthy individuals possessing the PNPLA3-I148M mutation were characterized for changes in lipid metabolism, cellular stress, and survival. Using lipidomics, metabolomics, stable isotope tracing, and flux propensity analysis, we created a comprehensive metabolic profile of the changes associated with the PNPLA3-I148M variant. Functional analysis showed that the presence of the PNPLA3-I148M variant increased endoplasmic reticulum stress, mitochondrial dysfunction, and peroxisomal β-oxidation, ultimately leading to cell death via ferroptosis. Nutritional interventions, ferroptosis-specific inhibitors, and genetic approaches modulating GPX4 activity in PNPLA3-I148M HAHs and iHeps decreased programmed cell death. Our findings indicate that therapies targeting ferroptosis in patients carrying the PNPLA3-I148M variant could affect the development of MASLD and ESLD and highlight the utility of iPSC-based models for the study of genetic contributions to hepatic disorders.
Authors
Rodrigo M. Florentino, Olamide Animasahun, Nils Haep, Minal Nenwani, Kehinde Omoloja, Leyla Nurcihan Altay, Abhinav Achreja, Kazutoyo Morita, Takashi Motomura, Ricardo Diaz-Aragon, Lanuza A.P. Faccioli, Yiyue Sun, Zhenghao Liu, Zhiping Hu, Bo Yang, Fulei Wuchu, Ajay Shankaran, Miya Paserba, Annalisa M. Baratta, Shohrat Arazov, Zehra N. Kocas-Kilicarslan, Noah Meurs, Jaideep Behari, Edgar N. Tafaleng, Jonathan Franks, Alina Ostrowska, Takahiro Tomiyama, Kyohei Yugawa, Akinari Morinaga, Zi Wang, Kazuki Takeishi, Dillon C. Gavlock, Mark Miedel, D. Lansing Taylor, Ira J. Fox, Tomoharu Yoshizumi, Deepak Nagrath, Alejandro Soto-Gutierrez
Abstract
Mammalian skin wounds typically heal with a scar, characterized by fibrotic tissue that disrupts original tissue architecture and function. Therapies that limit fibrosis and promote regenerative healing remain a major unmet clinical need. Rosemary extract, particularly in the form of topical oils and creams, has gained widespread public attention for its purported wound-healing properties. However, its efficacy and mechanism of action remain poorly understood. We show in adult wound healing mouse models that an ethanol-based rosemary extract accelerates the speed of wound healing and mitigates fibrosis. Mechanistically, we identify that carnosic acid, a major bioactive component of rosemary leaves, activates the transient receptor potential ankyrin 1 (TRPA1) nociceptor on cutaneous sensory neurons to enhance tissue regeneration. Mice lacking TRPA1 in sensory neurons do not exhibit these pro-regenerative responses, confirming its role as a critical mediator. Together, these findings suggest that topical rosemary extract may represent an effective and accessible therapeutic approach to improve skin repair outcomes.
Authors
Emmanuel Rapp, Jiayi Pang, Borna Saeednia, Stephen Marsh Prouty, Christopher A. Reilly, Thomas H. Leung
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