Top read articles in the last 30 days
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Abstract
We generated a comparative spatial proteomic atlas of the human and mouse retina using a highly multiplexed immunohistochemistry technique called iterative bleaching extends multiplexity (IBEX). We refined the IBEX workflow by integrating an antibody dissociation option alongside chemical bleaching. This dual strategy enabled removal of the entire antibody complex, permitting the flexible use of antibodies from the same host species across iterative cycles. We coupled this workflow with super-resolution imaging via deconvolution and applied it to the retina of healthy humans and WT mice and the Crb1rd8 mouse model. We successfully imaged over 25 protein markers on human and mouse tissue sections, generating spatial atlases of the major retinal cell populations. Cross-species protein expression was compared to scRNA-seq datasets to identify protein and transcript disparities. Super-resolution IBEX delineated the ultrastructural features of the outer limiting membrane (OLM), identifying CD44 as a core structural component tightly colocalized with a highly organized F-actin belt within Müller glial endfeet. Using the Crb1rd8 mouse model, disruption of this complex was spatially associated with rosette formation and OLM structural failure. In summary, spatial proteomic atlases of the human and mouse retina were used to reveal insights into the arrangement of major retinal cell populations and OLM structure.
Authors
Yuxuan Meng, Jakub Kubiak, Zuzanna Dzieniak, Lorna Fowler, Rose Avient, Jason Hopley, Linyulong Li, Chaoran Li, Yuan Tian, Bruno Charbit, Colin J. Chu
Total views: 2477
Abstract
GLP-1 receptor (GLP-1R) agonists decrease blood glucose and body weight and reduce rates of cardiovascular and renal disease. Although GLP-1R activation lowers blood pressure (BP), the underlying mechanisms remain incompletely understood and have been attributed to weight loss and endothelial cell GLP-1R signaling. Here, we show that GLP-1Rs in vascular smooth muscle cells (VSMCs) are essential for semaglutide-mediated BP reduction in mice. In contrast, GLP-1Rs in Tie2+ endothelial or immune cells are not required for semaglutide to lower BP. The VSMC GLP-1R is dispensable for the effects of semaglutide on food intake, body weight, and blood glucose but is required for its actions to increase glomerular filtration rate and promote natriuresis. Systemic semaglutide administration resulted in proteomic changes in the renal artery and kidney in pathways related to platelet aggregation, fibrin clot formation, lipid metabolism, and proapoptotic signaling that are abolished in mice lacking VSMC GLP-1R expression. Moreover, semaglutide directly induced vasorelaxation in preconstricted mesenteric arteries ex vivo. Together, these findings identify VSMCs as a key cellular target linking GLP-1R activation to BP regulation, renal electrolyte excretion, and proteomic changes in renal artery and kidney.
Authors
Kyle D. Medak, Jacqueline A. Koehler, Laurie L. Baggio, Maria J. Gonzalez-Rellan, Chi Kin Wong, Xiemin Cao, Vivikta Rao, Sean Kao, Yu Cui, Jiayi Fu, Easton Liaw, M. Golam Kabir, Jie Zhang, Jin Wei, Daniel J. Drucker
Total views: 2395
Abstract
Lysophosphatidic acid (LPA) is a bioactive lipid that signals through G protein–coupled receptors (LPA1–6) and regulates multiple cellular processes, including fibrosis. Although LPA signaling has been implicated in fibrotic diseases in several organs, its role in skeletal muscle remains unclear. Here, we show that LPA/LPA1 signaling promotes fibrogenesis after sciatic nerve transection. Denervation induces differential expression of LPA signaling axis components and a transient early increase in intramuscular LPA levels. Pharmacological inhibition of LPA1/3 with Ki16425, or genetic deletion of LPA1, reduces extracellular matrix accumulation and expansion of fibro/adipogenic progenitors (FAPs) in denervated muscle. Although LPA blockade suppresses atrophy-related gene expression, it does not fully preserve myofiber size. Mechanistically, denervation increases YAP/TAZ expression, nuclear localization in FAPs, and transcriptional activity, effects that are attenuated by LPA axis inhibition. Furthermore, pharmacological inhibition of YAP/TAZ with verteporfin reduces fibrosis after denervation, supporting their role as critical downstream mediators. Finally, transient denervation activates the LPA axis, promotes muscle fibrosis, reduces axonal density in the sciatic nerve, and increases neuromuscular junction instability, effects reversed by Ki16425. Together, these findings identify the LPA/LPA1/YAP/TAZ pathway as a key driver of denervation-induced muscle fibrosis and a potential therapeutic target in neuromuscular disorders.
Authors
Meilyn Cruz-Soca, Adriana Córdova-Casanova, Jennifer Faundez-Contreras, Nicolás W. Martínez, Francesca Vaccaro-Rivera, Sebastián Bazaes-Astorga, Cristian Gutiérrez-Rojas, Felipe S. Gallardo, Daniela L. Rebolledo, Felipe A. Court, Jerold Chun, Carlos P. Vio, Soledad Matus, Juan Carlos Casar, Enrique Brandan
Total views: 2224
Abstract
Systemic sclerosis (SSc) is characterized by fibrosis and vasculopathy affecting the skin and internal organs, leading to multiorgan dysfunction. Injury of microvascular endothelial cells (ECs) in SSc impairs blood flow and causes tissue ischemia, leading to vascular complications such as Raynaud’s, digital ulcers, and pulmonary hypertension (PH). PH in SSc presents as group 1 pulmonary arterial hypertension or as group 3 PH related to hypoxia and interstitial lung disease (ILD), both major causes of mortality. Analysis of multiome data from SSc ILD-PH lungs inferred transcription factors regulating EC phenotype, including FOSL2. Overexpression of FOSL2 in transgenic mice (Fosl2tg) leads to vascular changes mirroring human SSc-PH, such as intimal thickening and fibrosis. scRNA-Seq analysis of altered EC gene expression in Fosl2tg mice showed strong overlap with altered EC gene expression in SSc-ILD-PH. Overlapping as well as discrete EC gene expression in Sugen/hypoxia- and hypoxia-treated mice suggested that FOSL2 regulates both hypoxia-dependent and -independent pathways in Fosl2tg mice and SSc-ILD-PH. A deep learning model, ChromBPNet, inferred increased AP-1 binding at base pair resolution in SSc-ILD-PH ECs, and binding to the same motifs was found upon FOSL2 overexpression in primary vascular ECs, highlighting FOSL2’s key role in driving the pathological changes seen in SSc-ILD-PH.
Authors
Rithika Behera, Yuechen Zhou, Peter H. Gerges, Jingyu Fan, Tracy Tabib, Alyxzandria M. Gaydosik, Mengqi Huang, Jishnu Das, Elena Pachera, Amela Hukara, Ying Tang, Florian Renoux, Miranda Tai, Oliver Distler, Gabriela Kania, Stephen Y. Chan, Harinder Singh, Eleanor Valenzi, Robert Lafyatis
Total views: 2156
Abstract
Nearly 100 individuals have been identified who carry deleterious biallelic germline variants in CARD9 and experience life-threatening, invasive fungal infections caused by Ascomycetes but are otherwise resistant to other infectious agents. CARD9 is an adaptor protein expressed predominantly in myeloid cells, which functions downstream of dectin receptors, pattern recognition receptors for fungal antigens, to activate innate immune responses. The impact of CARD9 deficiency on lymphocytes, however, is less clear. We deciphered the functional consequences and delineated mechanisms of disease in a patient (P1) with a nonsense germline homozygous CARD9 variant (c.673A>T/p.K225*) and invasive Candida disease. P1’s PBMCs expressed truncated CARD9 and showed significantly reduced cytokine production in response to fungal ligands. P1 had reduced frequencies of circulating memory CD4+ TH17-like (CCR6+CXCR3–) cells. In addition, in vitro differentiation of P1’s naive CD4+ T cells into IL-17A/IL-17F–secreting cells was greatly impaired. Consistent with impaired responses of innate and adaptive immune cells from P1 in vitro, proportions of Candida-specific CD4+ T cells were strongly and selectively diminished. Our findings suggest that the CARD9 variant identified in P1 is pathogenic, affecting not only CARD9-induced immunity mediated by myeloid cells but also CD4+ T cell–intrinsic IL-17–dependent immunity and Candida-specific T cell responses.
Authors
Erika Della Mina, Carlos G. El-Haddad, Timothy A. West, Clara W.T. Chung, Jing Jing Li, Vivienne Lea, Elissa K. Deenick, Filomeen Haerynck, Jean-Laurent Casanova, Anne Puel, Cindy S. Ma, Stuart G. Tangye, Alisa Kane
Total views: 2097
Abstract
Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized by pruritic skin nodules of unknown etiology. Little is known about genetic changes in PN pathogenesis, particularly somatic events, which are often implicated in inflammatory conditions. We thus performed whole-exome sequencing on 54 lesional and nonlesional skin biopsies from 17 patients with PN and 10 patients with atopic dermatitis (AD) for comparison. Somatic mutational analysis revealed that PN lesional skin harbors recurrent somatic mutations in fibrotic, neurotropic, and cancer-associated genes that are absent in adjacent PN nonlesional skin. Nonsynonymous mutations were most frequently present in NOTCH1 and the Notch signaling pathway, a key regulator of cellular proliferation and tissue fibrosis. In contrast, NOTCH1 mutations were absent in AD. Somatic copy-number analysis, combined with expression data, identified recurrently deleted and downregulated genes in PN lesional skin, which are associated with axonal guidance and extension. Follow-up immunofluorescence validation demonstrated increased NOTCH1 expression in PN lesional skin fibroblasts and increased Notch signaling in PN lesional dermis. Finally, a multicenter analysis revealed increased risk of NOTCH1-associated diseases in patients with PN. In characterizing the somatic landscape of PN, this study highlights the potential role of Notch pathway dysregulation in PN pathogenesis and fibrosis.
Authors
Ahmad Rajeh, Shahin Shahsavari, Hannah Cornman, Alexander Kollhoff, Anuj Gupta, Mindy D. Szeto, Anusha Kambala, Olusola O. Oladipo, Varsha Parthasarathy, Junwen Deng, Melika Marani, Shirin Shahsavari, Selina M. Yossef, Vedha Vaddaraju, Waleed Adawi, Yagiz M. Akiska, Davies M. Gage, Sarah Wheelan, Thomas Pritchard, Madan M. Kwatra, Yevgeniy R. Semenov, Alexander Gusev, Won Jin Ho, Srinivasan Yegnasubramanian, Shawn G. Kwatra
Total views: 2045
Abstract
Macrophages, endowed with remarkable phenotypic plasticity, are essential for orchestrating injury responses and regulating iron homeostasis. Given the central role of ferritin heavy chain (FtH) as a molecular rheostat linking iron sequestration to redox-dependent signaling, we examined how myeloid FtH governs renal iron trafficking and ensuing oxidative stress pathways during acute kidney injury (AKI). Transcriptome analysis revealed coupling of FtH deficiency in monocytes and macrophages with activation of ferroptosis, a regulated cell death associated with iron accumulation. Moreover, myeloid FtH deletion worsened AKI, increasing leukocyte infiltration and iron deposition, together with ferroptosis-associated gene induction, oxidative stress, and lipid peroxidation. Notably, α-synuclein (SNCA), an iron-binding protein and the main pathological driver of Parkinson’s disease, was robustly induced both by FtH deficiency and following AKI. Mechanistic studies showed that monomeric SNCA exhibits ferrireductase activity, amplifying redox cycling and promoting ferroptotic cell death. Furthermore, SNCA expression was elevated in kidney pathologies characterized by leukocyte expansion in both mouse models and human cohorts, suggesting that inflammatory microenvironments promote SNCA accumulation and redox imbalance. These findings define a macrophage FtH/SNCA regulatory axis as a key driver of ferroptosis in AKI, implicating SNCA as a pathological nexus between iron dyshomeostasis and inflammatory kidney injury.
Authors
Tanima Chatterjee, Sarah Machado, Kellen Cowen, Mary E. Miller, Bronte Johnson, Yanfeng Zhang, Laura A. Volpicelli-Daley, Lauren A. Fielding, Rudradip Pattanayak, Frida Rosenblum, László Potor, György Balla, Jozsef Balla, Christian Faul, Abolfazl Zarjou
Total views: 1914
Abstract
BACKGROUND High-dose influenza vaccine, containing 4 times more antigen than the standard dose, is recommended for people 65 years or older, but there is a knowledge gap surrounding its effect in people with HIV (PWH), who remain more vulnerable to serious influenza infections than people without HIV (PWoH) despite virological suppression. Our primary goal was to assess whether the high-dose vaccine improves antibody responses in PWH, especially older PWH.METHODS We assessed antibody responses to sequential high- versus standard-dose influenza vaccination in PWH. Young (18–40 years) PWoH (n = 55) and PWH (n = 37) and older (≥60 years) PWoH (n = 72) and PWH (n = 67) received a standard-dose vaccine during the 2020–2024 seasons, and 123 participants (41 older PWH) received a high-dose vaccine the subsequent season. All PWH were virologically suppressed on antiretroviral therapy. HA inhibition (HAI) titer and HA-specific IgG were analyzed at 0 to 180 days after vaccination; T cell activation–induced responses were assessed by flow cytometry.RESULTS All groups mounted significant HAI and IgG responses to all vaccine antigens at 28 days after standard- and high-dose vaccination. Responses to A/H1N1 were lower in magnitude and durability in older PWH compared with young PWoH after the standard dose and were not boosted with the high dose, whereas the high dose enhanced A/H3N2 and B/Victoria IgG, in addition to CD4+ T cell responses to all antigens, in older PWH.CONCLUSION Our data demonstrate partial efficacy of a high-dose vaccine in augmenting antibody responses of older PWH while highlighting limitations in boosting A/H1N1-specific responses.TRIAL REGISTRATION ClinicalTrials.gov NCT04487041.FUNDING NIH grant (5R01AG068110).
Authors
Jonah Kupritz, Sheldon Davis, TianHao Liu, Prabhsimran Singh, Daniel Andrés Díaz-Pachón, Allan Rodriguez, Scott D. Boyd, Rajendra Pahwa, Suresh Pallikkuth, Savita G. Pahwa
Total views: 1883
Abstract
At-home blood collection devices (ABCDs) can facilitate study participation for remote and rural cohorts. Previous studies used ABCDs to interrogate samples by proteomics and sequencing approaches. We wanted to address the question of whether this approach could be used to assess live immune cells with high-parameter flow cytometry to enable remote immune monitoring. We first compared blood from standard venipuncture with ABCD blood draws, followed by assessment of the impact of sample shipping on immune cell viability and phenotyping. We found that capillary blood collected with a Tasso+ device and concurrently drawn venipuncture blood samples had highly congruent immune cell composition and phenotype. Shipment of Tasso+ samples via the United States Postal Service altered the myeloid compartment, but T cell numbers, subsets, and phenotypes remained remarkably stable compared with non-shipped samples. Finally, we describe a flow cytometry analysis framework that allowed for direct sample comparison even when samples were stained and analyzed over a time period of 1.5 years. Overall, our data highlight the feasibility of using ABCDs combined with subsequent flow cytometry analysis for remote immune monitoring. Additionally, our study also identifies areas that could be improved to further promote the use of ABCDs for immune monitoring.
Authors
Andrew J. Konecny, Fang Yun Lim, Eva Domenjo-Vila, Erika Lovas, Rachel L. Blazevic, Louise E. Kimball, Michael Boeckh, Alpana Waghmare, Martin Prlic
Total views: 1876
Abstract
Adipocytes exist along a functional spectrum: white adipocytes are energy storing, and brown adipocytes have thermogenic capacity such that activation may counteract obesity-related disease. In between are UCP1-expressing beige adipocytes, which can transition between these two energetic states. We previously showed that bone morphogenetic protein 7 (BMP7), a member of the TGF-β superfamily, enables differentiation of brown preadipocytes to mature thermogenic cells. To see whether immortalized, clonal human white and brown preadipocytes (hWAs and hBAs, respectively) would become more thermogenic in response to BMP exposure, we treated them with BMP7 or BMP4 for the first 7 days of a 30-day differentiation protocol. In hBAs, absence of either BMP7 or BMP4 led to lower expression of brown-specific markers and oxygen consumption relative to 7 days with either BMP. hWAs treated for 7 days with either BMP did not increase expression of thermogenic protein UCP1 nor induce a brown-like transcription profile. However, BMP-treated hWAs produced adipocytes that had higher basal and drug-induced maximal oxygen consumption, which was UCP1-independent and due substantially to the futile creatine cycle. Our results demonstrate that energetically quiescent hWAs can be pushed into an energy-expending phenotype without transdifferentiation into beige adipocytes, providing a new approach to treat obesity-related metabolic disease.
Authors
Kelly T. Long, Cheryl Cero, Sahara L. Ali, Nhuquynh Nguyen, Adrienne R. Guarnieri, Ju Hee Kim, Young Jae Bahn, Jurgen Heymann, Jonathan M. Dreyfuss, Sushil G. Rane, Yu-Hua Tseng, Aaron M. Cypess
Total views: 1875
