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Mutations in the gap junction β2 (GJB2) gene, which encodes connexin 26, are the leading cause of genetic deafness. These mutations are characterized by the degeneration and fragmentation of gap junctions and gap junction plaques (GJPs) composed of connexin 26. Dominant-negative mutations of GJB2, such as R75W, cause syndromic hearing loss and palmoplantar keratoderma. We previously reported that the R75W mutation, a single-base substitution where C is replaced by T, causes fragmentation of GJPs. Therefore, an adenine base editor (ABE), which enables A-to-G base conversions, can potentially be useful for the treatment of this genetic disease. Here, we report that an all-in-one adeno-associated virus (AAV) vector, which includes a compact ABE (SaCas9-NNG-ABE8e) with broad targeting range, and a sgRNA targeting the R75W mutation in GJB2 corrected this pathogenic mutation and facilitated the recovery of the gap junction intercellular communication network of GJPs. In a transgenic mouse model with the GJB2 R75W mutation, AAV-mediated base editing also restored the fragmented GJPs to orderly outlines in cochlear supporting cells. Our findings suggest that an ABE-based base-editing strategy could be an optimal treatment for the dominant form of GJB2-related hearing loss, GJB2-related skin diseases, and other deafness-related mutations, especially single-base substitutions.
Takao Ukaji, Daisuke Arai, Harumi Tsutsumi, Ryoya Nakagawa, Fumihiko Matsumoto, Katsuhisa Ikeda, Osamu Nureki, Kazusaku Kamiya
Total views: 4244
Chronic kidney diseases (CKDs) are a global health concern, necessitating a comprehensive understanding of their complex pathophysiology. This study explores the use of 2 complementary multidimensional -omics data integration methods to elucidate mechanisms of CKD progression as a proof of concept. Baseline biosamples from 37 participants with CKD in the Clinical Phenotyping and Resource Biobank Core (C-PROBE) cohort with prospective longitudinal outcome data ascertained over 5 years were used to generate molecular profiles. Tissue transcriptomic, urine and plasma proteomic, and targeted urine metabolomic profiling were integrated using 2 orthogonal multi-omics data integration approaches, one unsupervised and the other supervised. Both integration methods identified 8 urinary proteins significantly associated with long-term outcomes, which were replicated in an adjusted survival model using 94 samples from an independent validation group in the same cohort. The 2 methods also identified 3 shared enriched pathways: the complement and coagulation cascades, cytokine–cytokine receptor interaction pathway, and the JAK/STAT signaling pathway. Use of different multiscalar data integration strategies on the same data enabled identification and prioritization of disease mechanisms associated with CKD progression. Approaches like this will be invaluable with the expansion of high-dimension data in kidney diseases.
Fadhl Alakwaa, Vivek Das, Arindam Majumdar, Viji Nair, Damian Fermin, Asim B. Dey, Timothy Slidel, Dermot F. Reilly, Eugene Myshkin, Kevin L. Duffin, Yu Chen, Markus Bitzer, Subramaniam Pennathur, Frank C. Brosius, Matthias Kretzler, Wenjun Ju, Anil Karihaloo, Sean Eddy
Total views: 2228
Chronic kidney disease (CKD) is associated with renal metabolic disturbances, including impaired fatty acid oxidation (FAO). Nicotinamide adenine dinucleotide (NAD+) is a small molecule that participates in hundreds of metabolism-related reactions. NAD+ levels are decreased in CKD, and NAD+ supplementation is protective. However, both the mechanism of how NAD+ supplementation protects from CKD, as well as the cell types involved, are poorly understood. Using a mouse model of Alport syndrome, we show that nicotinamide riboside (NR), an NAD+ precursor, stimulated renal PPARα signaling and restored FAO in the proximal tubules, thereby protecting from CKD in both sexes. Bulk RNA-sequencing showed that renal metabolic pathways were impaired in Alport mice and activated by NR in both sexes. These transcriptional changes were confirmed by orthogonal imaging techniques and biochemical assays. Single-nuclei RNA sequencing and spatial transcriptomics, both the first of their kind to our knowledge from Alport mice, showed that NAD+ supplementation restored FAO in proximal tubule cells. Finally, we also report, for the first time to our knowledge, sex differences at the transcriptional level in this Alport model. In summary, the data herein identify a nephroprotective mechanism of NAD+ supplementation in CKD, and they demonstrate that this benefit localizes to the proximal tubule cells.
Bryce A. Jones, Debora L. Gisch, Komuraiah Myakala, Amber Sadiq, Ying-Hua Cheng, Elizaveta Taranenko, Julia Panov, Kyle Korolowicz, Ricardo Melo Ferreira, Xiaoping Yang, Briana A. Santo, Katherine C. Allen, Teruhiko Yoshida, Xiaoxin X. Wang, Avi Z. Rosenberg, Sanjay Jain, Michael T. Eadon, Moshe Levi
Total views: 1859
Crohn’s disease (CD) involves a complex intestinal microenvironment driven by chronic inflammation. While single-cell RNA sequencing has provided valuable insights into this biology, the spatial context is lost during single-cell preparation of mucosal biopsies. To deepen our understanding of the distinct inflammatory signatures of CD and overcome the limitations of single-cell RNA sequencing, we combined spatial transcriptomics of frozen CD surgical tissue sections with single-cell transcriptomics of ileal CD mucosa. Coexpressed genes and cell-cell communication from single-cell analyses and factorized genes from spatial transcriptomics revealed overlapping pathways affected in inflamed CD, like antigen presentation, phagosome activity, cell adhesion, and extracellular matrix. Within the pathways, early epithelial cells showed evidence of significant changes in gene expression and subtype composition, while spatial mapping revealed the location of the events, particularly antigen presentation from epithelial cells in the base of the crypt. Furthermore, we identified early epithelial cells as a potential mediator of the MHC class II pathway during inflammation, which we validated by spatial transcriptomics cell subtype deconvolution. Therefore, the inflammation from CD appears to change the types of interactions detectable between epithelial cells with immune and mesenchymal cells, likely promoting the conditions for more macrophage infiltration into these inflammatory microdomains.
Vasantha L. Kolachala, Sushma Chowdary Maddipatla, Shanta Murthy, Yeonjoo Hwang, Anne F. Dodd, Garima Sharma, Sachith Munasinghe, Ranjit Singh Pelia, Suresh Venkateswaran, Murugadas Anbazhagan, Tarun Koti, Navdeep Jhita, Gaurav N. Joshi, Chrissy A. Lopez, Duke Geem, Hong Yin, David J. Cutler, Peng Qiu, Jason D. Matthews, Subra Kugathasan
Total views: 1840
High-grade serous ovarian cancer (HGSOC) is the most prevalent and aggressive histological subtype of ovarian cancer and often presents with metastatic disease. The drivers of metastasis in HGSOC remain enigmatic. APOBEC3A (A3A), an enzyme that generates mutations across various cancers, has been proposed as a mediator of tumor heterogeneity and disease progression. However, the role of A3A in HGSOC has not been explored. We observed an association between high levels of APOBEC3-mediated mutagenesis and poor overall survival in primary HGSOC. We experimentally addressed this correlation by modeling A3A expression in HGSOC, and this resulted in increased metastatic behavior of HGSOC cells in culture and distant metastatic spread in vivo, which was dependent on catalytic activity of A3A. A3A activity in both primary and cultured HGSOC cells yielded consistent alterations in expression of epithelial-mesenchymal transition (EMT) genes resulting in hybrid EMT and mesenchymal signatures, providing a mechanism for their increased metastatic potential. Inhibition of key EMT factors TWIST1 and IL-6 resulted in mitigation of A3A-dependent metastatic phenotypes. Our findings define the prevalence of A3A mutagenesis in HGSOC and implicate A3A as a driver of HGSOC metastasis via EMT, underscoring its clinical relevance as a potential prognostic biomarker. Our study lays the groundwork for the development of targeted therapies aimed at mitigating the deleterious effect of A3A-driven EMT in HGSOC.
Jessica M. Devenport, Thi Tran, Brooke R. Harris, Dylan Fingerman, Rachel A. DeWeerd, Lojain H. Elkhidir, Danielle LaVigne, Katherine Fuh, Lulu Sun, Jeffrey J. Bednarski, Ronny Drapkin, Mary M. Mullen, Abby M. Green
Total views: 1491
Glioblastoma (GBM) is the most lethal brain cancer, with GBM stem cells (GSCs) driving therapeutic resistance and recurrence. Targeting GSCs offers a promising strategy for preventing tumor relapse and improving outcomes. We identify SUV39H1, a histone-3, lysine-9 methyltransferase, as critical for GSC maintenance and GBM progression. SUV39H1 is upregulated in GBM compared with normal brain tissues, with single-cell RNA-seq showing its expression predominantly in GSCs due to super-enhancer–mediated activation. Knockdown of SUV39H1 in GSCs impaired their proliferation and stemness. Whole-cell RNA-seq analysis revealed that SUV39H1 regulates G2/M cell cycle progression, stem cell maintenance, and cell death pathways in GSCs. By integrating the RNA-seq data with ATAC-seq data, we further demonstrated that knockdown of SUV39H1 altered chromatin accessibility in key genes associated with these pathways. Chaetocin, an SUV39H1 inhibitor, mimics the effects of SUV39H1 knockdown, reducing GSC stemness and sensitizing cells to temozolomide, a standard GBM chemotherapy. In a patient-derived xenograft model, targeting SUV39H1 inhibits GSC-driven tumor growth. Clinically, high SUV39H1 expression correlates with poor glioma prognosis, supporting its relevance as a therapeutic target. This study identifies SUV39H1 as a crucial regulator of GSC maintenance and a promising therapeutic target to improve GBM treatment and patient outcomes.
Chunying Li, Qiqi Xie, Sugata Ghosh, Bihui Cao, Yuanning Du, Giau V. Vo, Timothy Y. Huang, Charles Spruck, Richard L. Carpenter, Y. Alan Wang, Q. Richard Lu, Kenneth P. Nephew, Jia Shen
Total views: 1462
Skin inflammation in juvenile dermatomyositis (JDM) can signal disease onset or flare, and the persistence of cutaneous disease can prevent complete disease remission. The non-invasive study of cutaneous expression signatures through tape stripping (TS) holds the potential to reveal mechanisms underlying disease heterogeneity and organ-specific inflammation. The objectives of this study were to 1) define TS expression signatures in lesional and non-lesional JDM skin, 2) analyze TS signatures to identify JDM disease endotypes and 3) compare TS and blood signatures. While JDM lesional skin demonstrated interferon signaling as the top upregulated pathway, non-lesional skin uniquely highlighted pathways involved in metabolism, angiogenesis and calcium signaling. Both lesional and non-lesional skin shared inflammasome pathway dysregulation. Using unsupervised clustering of skin expression data, we identified a treatment-refractory JDM subgroup distinguished by upregulation of genes associated with mitochondrial dysfunction. The treatment-refractory JDM subgroup also demonstrated higher interferon, angiogenesis and innate immune expression scores in skin and blood, although scores were more pronounced in skin as compared to blood. Tape-stripping expression signatures in JDM provided insight into disease mechanisms and molecular subgroups. Skin, as compared to blood, transcriptional profiles served as more sensitive markers to classify disease subgroups and identify candidate treatment targets.
Jessica L. Turnier, Sarah M.H. Vandenbergen, Madison E. McClune, Christine Goudsmit, Sophia Matossian, Meredith Riebschleger, Nadine Saad, Jacqueline A. Madison, Smriti Mohan, Johann E. Gudjonsson, Lam C. Tsoi, Celine C. Berthier, J. Michelle Kahlenberg
Total views: 1440
Recently, skeletal stem cells were shown to be present in the epiphyseal growth plate (epiphyseal skeletal stem cells, epSSCs), but their function in connection with linear bone growth remains unknown. Here, we explore the possibility that modulating the number of epSSCs can correct differences in leg length. First, we examined regulation of the number and activity of epSSCs by Hedgehog (Hh) signaling. Both systemic activation of Hh pathway with Smoothened agonist (SAG) and genetic activation of Hh pathway by Patched1 (Ptch1) ablation in Pthrp-creER Ptch1fl/fl tdTomato mice promoted proliferation of epSSCs and clonal enlargement. Transient intra-articular administration of SAG also elevated the number of epSSCs. When SAG-containing beads were implanted into the femoral secondary ossification center of 1 leg of rats, this leg was significantly longer 1 month later than the contralateral leg implanted with vehicle-containing beads, an effect that was even more pronounced 2 and 6 months after implantation. We conclude that Hh signaling activates growth plate epSSCs, which effectively leads to increased longitudinal growth of bones. This opens therapeutic possibilities for the treatment of differences in leg length.
Dana Trompet, Anastasiia D. Kurenkova, Baoyi Zhou, Lei Li, Ostap Dregval, Anna P. Usanova, Tsz Long Chu, Alexandra Are, Andrei A. Nedorubov, Maria Kasper, Andrei S. Chagin
Total views: 1439
Idiopathic pulmonary fibrosis (IPF) causes remodeling of the distal lung. Pulmonary remodeling is histologically characterized by fibrosis, as well as appearance of basal cells; however, the involvement of basal cells in IPF remains unclear. Here, we focus on the long noncoding RNA MIR205HG, which is highly expressed in basal cells, using RNA sequencing. Through RNA sequencing of genetic manipulations using primary cells and organoids, we discovered that MIR205HG regulates IL-33 expression. Mechanistically, the AluJb element of MIR205HG plays a key role in IL-33 expression. Additionally, we identified a small molecule that targets the AluJb element, leading to decreased IL-33 expression. IL-33 is known to induce type 2 innate lymphoid cells (ILC2s), and we observed that MIR205HG expression was positively correlated with the number of ILC2s in patients with IPF. Collectively, these findings provide insights into the mechanisms by which basal cells contribute to IPF and suggest potential therapeutic targets.
Tsuyoshi Takashima, Chao Zeng, Eitaro Murakami, Naoko Fujiwara, Masaharu Kohara, Hideki Nagata, Zhaozu Feng, Ayako Sugai, Yasue Harada, Rika Ichijo, Daisuke Okuzaki, Satoshi Nojima, Takahiro Matsui, Yasushi Shintani, Gota Kawai, Michiaki Hamada, Tetsuro Hirose, Kazuhiko Nakatani, Eiichi Morii
Total views: 1416
Dengue is widespread in tropical and subtropical regions globally and imposes a considerable disease burden. Annually, dengue virus (DENV) causes up to 400 million infections, of which approximately 25% present with clinical manifestations ranging from mild to fatal. Despite its significance as a growing public health concern, developing effective DENV vaccines has been challenging. One reason is the lack of comprehensive understanding of the influence exerted by prior DENV infections and immune responses with cross-reactive properties. To investigate this, we collected samples from a pediatric cohort study in dengue-endemic Managua, Nicaragua. We characterized T cell responses in 71 healthy children who had previously experienced 1 or more natural DENV infections and who, within 1 year after sample collection, had a subsequent DENV infection that was either symptomatic or inapparent. Our study investigated the effect of preexisting DENV-specific T cell responses on clinical outcomes of subsequent DENV infection. We assessed DENV-specific T cell responses using an activation-induced marker assay. Children with only 1 prior DENV infection displayed heterogeneous DENV-specific CD4+ and CD8+ T cell frequencies. In contrast, children with 2 or more prior DENV infections showed significantly higher DENV-specific CD4+ and CD8+ T cell frequencies associated with inapparent rather than symptomatic outcomes in subsequent infection. These findings demonstrate the protective role of DENV-specific T cells against symptomatic DENV infection and advance efforts to identify protective immune correlates against dengue.
Rosa Isela Gálvez, Amparo Martínez-Pérez, E. Alexandar Escarrega, Tulika Singh, José Victor Zambrana, Ángel Balmaseda, Eva Harris, Daniela Weiskopf
Total views: 1382