Martin et al. report that SREBP2 mediates transcriptomic, epigenetic, and phenotypic changes in endothelial cells that promote mesenchymal transition and lead to exacerbated pulmonary fibrosis. The cover image shows an angiogram produced following Microfil injection to reveal lung vascularization in a WT mouse.
Identification and analysis of fungal communities commonly rely on internal transcribed spacer (ITS)-based amplicon sequencing. There is no gold standard to infer and classify fungal constituents since methodologies have been adapted from analyses of bacterial communities. To achieve high resolution inference of fungal constituents, we customized a DADA2-based pipeline using a mix of eleven medically relevant fungi. While DADA2 allowed the discrimination of ITS1 sequences differing by single nucleotides, quality filtering, sequencing bias, and database selection were identified as key variables determining the accuracy of sample inference. Due to species-specific differences in sequencing quality, default filtering settings removed most reads that originated from Aspergillus species, Saccharomyces cerevisiae, and Candida glabrata. By fine-tuning the quality filtering process, we achieved an improved representation of the fungal communities. By adapting a wobble nucleotide in the ITS1 forward primer region, we further increased the yield of S. saccharomyces and C. glabrata sequences. Finally, we showed that a BLAST-based algorithm based on the UNITE+INSD or the NCBI NT database achieved a higher reliability in species-level taxonomic annotation than the naïve Bayesian classifier implemented in DADA2. These steps optimized a robust fungal ITS1 sequencing pipeline that, in most instances, enabled species level-assignment of community members.
Thierry Rolling, Bing Zhai, John Frame, Tobias M. Hohl, Ying Taur
While current thinking posits that insulin signaling to GLUT4 exocytic translocation and glucose uptake in skeletal muscle and adipocytes is controlled by phosphorylation-based signaling, many proteins in this pathway are acetylated on lysine residues. However, the importance of acetylation and lysine acetyltransferases to insulin-stimulated glucose uptake is incompletely defined. Here, we demonstrate that combined loss of the acetyltransferases E1A binding protein p300 (p300) and cAMP response element binding protein binding protein (CBP) in mouse skeletal muscle causes a complete loss of insulin-stimulated glucose uptake. Similarly, brief (i.e. 1 h) pharmacological inhibition of p300/CBP acetyltransferase activity recapitulates this phenotype in human and rodent myotubes, 3T3-L1 adipocytes, and mouse muscle. Mechanistically, these effects are due to p300/CBP-mediated regulation of GLUT4 exocytic translocation and occurs downstream of Akt signaling. Taken together, we highlight a fundamental role for acetylation and p300/CBP in the direct regulation of insulin-stimulated glucose transport in skeletal muscle and adipocytes.
Vitor F. Martins, Samuel A. LaBarge, Alexandra Stanley, Kristoffer Svensson, Chao-Wei Hung, Omer Keinan, Theodore P. Ciaraldi, Dion Banoian, Ji E. Park, Christina Ha, Byron Hetrick, Gretchen A. Meyer, Andrew Philp, Larry L. David, Robert R. Henry, Joseph E. Aslan, Alan R. Saltiel, Carrie E. McCurdy, Simon Schenk
Sangivamycin is a nucleoside analog that is well-tolerated by humans and broadly active against phylogenetically distinct viruses, including arenaviruses, filoviruses, and orthopoxviruses. Here, we show that sangivamycin is a potent antiviral against multiple variants of replicative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with half-maximal inhibitory concentration (IC50) in the nanomolar range in several cell types. Sangivamycin suppressed SARS-CoV-2 replication with greater efficacy than remdesivir (another broad-spectrum nucleoside analog). When we investigated sangivamycin’s potential for clinical administration, pharmacokinetic, ADME (absorption, distribution, metabolism, and excretion), and toxicity properties were found to be favorable. When tested in combination with remdesivir, efficacy was additive rather than competitive against SARS-CoV-2. The proven safety in humans, long half-life, potent antiviral activity (compared to remdesivir), and combinatorial potential suggest that sangivamycin is likely to be efficacious alone or in combination therapy to suppress viremia in patients. Sangivamycin may also have the ability to help combat drug-resistant or vaccine-escaping SARS-CoV-2 variants since it is antivirally active against several tested variants. Our results support the pursuit of sangivamycin for further preclinical and clinical development as a potential coronavirus disease 2019 (COVID-19) therapeutic.
Ryan P. Bennett, Elena N. Postnikova, Brett P. Eaton, Yingyun Cai, Shuiqing Yu, Charles O. Smith, Janie Liang, Huanying Zhou, Gregory A. Kocher, Michael J. Murphy, Harold C. Smith, Jens H. Kuhn
The clinical utility of histone/protein deacetylase (HDAC) inhibitors (HDACi’s) in combinatorial regimens with proteasome inhibitors for patients with relapsed and refractory multiple myeloma (MM) is limited often by excessive toxicity due to HDACi promiscuity with multiple HDACs. Therefore, more selective inhibition minimizing off-target toxicity may increase the clinical effectiveness of HDACi’s. We demonstrate that both plasma cell (PC) development and survival are dependent upon HDAC11, suggesting this enzyme is a promising therapeutic target in MM. Mice lacking HDAC11 exhibited markedly decreased PC numbers. Accordingly, in vitro PC differentiation was arrested in B cells lacking functional HDAC11. Mechanistically, we show that HDAC11 is involved in the deacetylation of IRF4 at lysine103. Further, targeting HDAC11 led to IRF4 hyperacetylation resulting in impaired IRF4 nuclear localization and target promoter binding. Importantly, transient HDAC11 knockdown or treatment with elevenostat, an HDAC11-selective inhibitor, induced cell death in MM cell lines. Elevenostat produced similar anti-MM activity in vivo, improving survival among mice inoculated with 5TGM1 MM cells. Elevenostat demonstrated nanomolar ex vivo activity in 34 MM patient specimens and synergistic activity when combined with bortezomib. Collectively, our data indicate that HDAC11 is an emerging therapeutic vulnerability in MM by targeting an essential pathway in PC biology.
AGM Mostofa, Allison Distler, Mark B. Meads, Eva Sahakian, John J. Powers, Alexandra Achille, David Noyes, Gabriela Wright, Bin Fang, Victoria Izumi, John Koomen, Rupal Rampakrishnan, Tuan P. Nguyen, Gabriel De Avila, Ariosto S. Silva, Praneeth Sudalagunta, Rafael Renatino Canevarolo, Maria D. Coelho Siqueira Silva, Raghunandan Reddy Alugubelli, Hongyue A. Dai, Amit Kulkarni, William S. Dalton, Oliver A. Hampton, Eric A. Welsh, Jamie K. Teer, Alexandre Tungesvik, Kenneth L. Wright, Javier Pinilla-Ibarz, Eduardo M. Sotomayor, Kenneth H. Shain, Jason Brayer
Alport syndrome (AS) is a genetic disorder caused by mutations in type IV collagen that leads to defective glomerular basement membrane, glomerular filtration barrier (GFB) damage, and progressive chronic kidney disease. While the genetic basis of AS is well known, the molecular and cellular mechanistic details of disease pathogenesis have been elusive, hindering the development of mechanism-based therapies. Here we performed intravital multiphoton imaging of the local kidney tissue microenvironment in a X-linked AS mouse model to directly visualize the major drivers of AS pathology. Severely distended glomerular capillaries and aneurysms were found accompanied by numerous microthrombi, increased glomerular endothelial surface layer (glycocalyx) and immune cell homing, GFB albumin leakage, glomerulosclerosis and interstitial fibrosis by 5 months of age with an intermediate phenotype at 2 months. Renal histology in mouse or patient tissues largely failed to detect capillary aberrations. Treatment of AS mice with hyaluronidase or the ACE inhibitor enalapril reduced the excess glomerular endothelial glycocalyx and blocked immune cell homing, and GFB albumin leakage. This study identified central roles of glomerular mechanical forces and endothelial and immune cell activation early in AS, which could be therapeutically targeted to reduce mechanical strain and local tissue inflammation and improve kidney function.
Georgina Gyarmati, Urvi Nikhil Shroff, Audrey Izuhara, Xiaogang Hou, Stefano Da Sacco, Sargis Sedrakyan, Kevin V. Lemley, Kerstin Amann, Laura Perin, János Peti-Peterdi
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