Mutation of the ATP2A2 gene encoding sarco-endoplasmic reticulum calcium ATPase 2 (SERCA2) was linked to Darier disease more than two decades ago; however, there remain no targeted therapies for this disorder causing recurrent skin blistering and infections. Since Atp2a2 knockout mice do not phenocopy its pathology, we established a human tissue model of Darier disease to elucidate its pathogenesis and identify potential therapies. Leveraging CRISPR/Cas9, we generated human keratinocytes lacking SERCA2, which replicated features of Darier disease, including weakened intercellular adhesion and defective differentiation in organotypic epidermis. To identify pathogenic drivers downstream of SERCA2 depletion, we performed RNA sequencing and proteomic analysis. SERCA2-deficient keratinocytes lacked desmosomal and cytoskeletal proteins required for epidermal integrity and exhibited excess MAP kinase signaling, which modulates keratinocyte adhesion and differentiation. Immunostaining patient biopsies substantiated these findings with lesions showing keratin deficiency, cadherin mis-localization, and ERK hyper-phosphorylation. Dampening ERK activity with MEK inhibitors rescued adhesive protein expression and restored keratinocyte sheet integrity despite SERCA2 depletion or chemical inhibition. In sum, coupling multi-omic analysis with human organotypic epidermis as a pre-clinical model, we found that SERCA2 haploinsufficiency disrupts critical adhesive components in keratinocytes via ERK signaling and identified MEK inhibition as a treatment strategy for Darier disease.
Shivam A. Zaver, Mrinal K. Sarkar, Shaun Egolf, Jonathan Zou, Afua Tiwaa, Brian C. Capell, Johann E. Gudjonsson, Cory L. Simpson
BACKGROUND. Severe forms of idiopathic nephrotic syndrome require prolonged immune-suppressive therapies and repeated courses of high-dose glucocorticoids. Mesenchymal stromal cells (MSCs) have promising immunomodulatory properties that may be employed therapeutically to reduce patient exposure to medications and their side effects. METHODS. We performed a phase 1 open-label trial assessing safety and feasibility of autologous bone marrow-derived (BM) MESenchymal stromal cells in children and young adults with severe forms of steroid-dependent NEPHrotic syndrome, (MESNEPH). Following autologous BM-MSC preparation and infusion, oral immunosuppression was tapered. Safety, efficacy and immunomodulatory effects in vivo were monitored for 12 months. RESULTS. Sixteen patients (10 children, 6 adults) were treated. Adverse events were limited and not related to BM-MSC infusions. All patients relapsed during follow-up, but in the 10 treated children, time to first relapse was delayed (p=0.02) and number of relapses was reduced (p=0.002) after BM-MSC infusion, compared to the previous 12 months. Cumulative prednisone dose was also reduced at 12 months compared to baseline (p<0.05). No treatment benefit was observed in adults. In children, despite tapering of immunosuppression, clinical benefit was mirrored by a significant reduction of total CD19+, mature and memory B cells and an increase of regulatory T cells in vivo up to 3-6 months following BM-MSC infusion. CONCLUSION. Treatment with autologous BM-MSC is feasible and safely reduces relapses and immunosuppression at 12 months in children with severe steroid-dependent INS. Immunomodulatory studies suggest that repeating MSC infusions at 3-6 months may sustain benefit. TRIAL REGISTRATION. EudraCT 2016-004804-77 FUNDING. AIFA Ricerca Indipendente 2016-02364623
Marina Vivarelli, Manuela Colucci, Mattia Algeri, Federica Zotta, Francesco Emma, Ines L'Erario, Marco Busutti, Stefano Rota, Chiara Capelli, Martino Introna, Marta Todeschini, Federica Casiraghi, Annalisa Perna, Tobia Peracchi, Andrea De Salvo, Nadia Rubis, Franco Locatelli, Giuseppe Remuzzi, Piero Ruggenenti
IgG4-related disease (IgG4-RD) is a systemic autoimmune disease with unclear pathogenesis. We performed single-cell RNA-seq and surface proteome analyses on 61,379 PBMCs from 9 treatment-naïve IgG4-RD patients and 7 age- and sex-matched healthy controls. Integrative analyses were performed for altered gene expression in IgG4-RD, and flow cytometry and immunofluorescence were used for validation. We observed expansion of plasmablasts with enhanced protein processing and activation, which correlated with number of involved organs in IgG4-RD. Increased proportions of CD4+ cytotoxic T lymphocytes (CTLs), CD8+ CTLs-GNLY (granulysin) and γδT cells with enhanced chemotaxis and cytotoxicity but with suppressed inhibitory receptors characterize IgG4-RD. Prominent infiltration of lymphocytes with distinct compositions were found in different organs of IgG4-RD patients. Transcription factors (TFs) including PRDM1/XBP1 and RUNX3 were upregulated in IgG4-RD, promoting the differentiation of plasmablasts and CTLs, respectively. Monocytes in IgG4-RD have stronger expression of genes related to cell adhesion and chemotaxis, which may give rise to profibrotic macrophages in lesions. The gene activation pattern in peripheral immune cells indicated activation of multiple interaction pathways between cell types, in part through chemokines or growth factors and their receptors. Specific upregulation of TFs and expansion of plasmablasts and CTLs may be involved in the pathogenesis of IgG4-RD, and each of these populations are candidate targets for therapeutic interventions in this disease.
Chenyang Lu, Shasha Li, Pingying Qing, Qiuping Zhang, Xing Ji, Zhigang Tang, Chunyan Chen, Tong Wu, Yidan Hu, Yi Zhao, Xiaohui Zhang, Qi He, David A. Fox, Chunyu Tan, Yubin Luo, Yi Liu
Acyl-CoA thioesterase 1 (ACOT1) catalyzes the hydrolysis of long-chain acyl-CoAs to free fatty acids and coenzyme A and is typically upregulated in obesity. Whether targeting ACOT1 in the setting of high-fat diet induced obesity would be metabolically beneficial is not known. Here we report that male and female ACOT1KO mice are partially protected from high-fat diet induced obesity, an effect associated with increased energy expenditure without alterations in physical activity or food intake. In males, ACOT1 deficiency increased mitochondrial uncoupling protein-2 (UCP2) protein abundance, while reducing 4-hydroxynonenal (4-HNE), a marker of oxidative stress, in white adipose tissue and liver of high-fat fed mice. Moreover, concurrent knockdown of UCP2 with ACOT1 in hepatocytes prevented increases in oxygen consumption observed with ACOT1 knockdown during high lipid loading, suggesting that UCP2-induced uncoupling may increase energy expenditure to attenuate weight gain. Together, these data indicate that targeting ACOT1 may be effective for obesity prevention during caloric excess by increasing energy expenditure.
Timothy D. Heden, Mallory P. Franklin, Christina Dailey, Mara T. Mashek, Chen Chen, Douglas G. Mashek
Metabolic mechanisms underlying the heterogeneity of major adverse cardiovascular events (MACE) risk in individuals with type 2 diabetes mellitus (T2D) remain unclear. We hypothesized that circulating metabolites reflecting mitochondrial dysfunction predict incident MACE in T2D. Targeted mass-spectrometry profiling of 60 metabolites was performed on baseline plasma from TECOS (discovery) and EXSCEL (validation) trial biomarker substudy cohorts. A principal components analysis metabolite factor comprised of medium-chain acylcarnitines was associated with MACE in TECOS and validated in EXSCEL, with higher levels associated with higher MACE risk. Meta-analysis showed that long-chain acylcarnitines and dicarboxylacylcarnitines were also associated with MACE. Metabolites remained associated with MACE in multivariate models and favorably changed with exenatide therapy. A third cohort (CATHGEN) with T2D assessed whether these metabolites improved discriminative capability multivariate for MACE; nine metabolites (medium- and long-chain acylcarnitines and one dicarboxylacylcarnitine) were associated with time-to-MACE in CATHGEN. Addition of these metabolites to clinical models minimally improved the discriminative capability for MACE but did significantly down reclassify risk. Thus, metabolites reporting on dysregulated mitochondrial fatty acid oxidation are higher in individuals with T2D who experience subsequent MACE. These biomarkers may improve CV risk prediction models, be therapy responsive, and highlight emerging risk mechanisms.
Jessica A. Regan, Robert J. Mentz, Maggie Nguyen, Jennifer B. Green, Lauren K. Truby, Olga Ilkayeva, Christopher Newgard, John B. Buse, Harald Sourij, C. David Sjöström, Naveed Sattar, Robert W. McGarrah, Yinggan Zheng, Darren K. McGuire, Eberhard Standl, Paul Armstrong, Eric Peterson, Adrian Hernandez, Rury R. Holman, Svati H. Shah
The growth of skeletal muscle relies on a delicate equilibrium between protein synthesis and degradation; however, how proteostasis is managed in the endoplasmic reticulum is largely unknown. Here, we report that the SEL1L-HRD1 endoplasmic reticulum (ER)-associated degradation (ERAD) complex, the primary molecular machinery that degrades misfolded proteins in the ER is vital to maintain postnatal muscle growth and systemic energy balance. Myocyte-specific SEL1L deletion blunts the hypertrophic phase of muscle growth, resulting in a net zero gain of muscle mass during this developmental period and a 30% reduction in overall body growth. In addition, myocyte-specific SEL1L deletion triggered a systemic reprogramming of metabolism characterized by improved glucose sensitivity, enhanced beiging of adipocytes, and resistance to diet induced obesity. These effects were partially mediated by the upregulation of the myokine FGF21. These findings highlight the pivotal role of SEL1L-HRD1 ERAD activity in skeletal myocytes for postnatal muscle growth, and its physiological integration in maintaining whole-body energy balance.
Benedict Abdon, Yusheng Liang, Débora da Luz Scheffer, Mauricio Torres, Neha Shrestha, Rachel B. Reinert, You Lu, Brent Pederson, Amara Bugarin-Lapuz, Sander Kersten, Ling Qi
Cutaneous lupus erythematosus (CLE) is a disfiguring autoimmune skin disease characterized by an inflammatory infiltrate rich in T cells, which are strongly implicated in tissue damage. How these cells adapt to the skin environment and promote tissue inflammation and damage is not known. In lupus nephritis, we have previously identified an inflammatory gene program in kidney-infiltrating T cells that is dependent on hypoxia-inducible factor-1 (HIF-1), a transcription factor critical for the cellular and developmental response to hypoxia as well as inflammation-associated signals. In our current studies using a mouse model of lupus skin disease, we find that skin-infiltrating CD4+ and CD8+ T cells also express high levels of HIF-1. Skin-infiltrating T cells demonstrate a strong cytotoxic signature at the transcript and protein level, and HIF-1 inhibition abrogates skin and systemic disease in association with decreased T cell cytotoxic activity. We also demonstrate in human CLE tissue that the T cell rich inflammatory infiltrate exhibits increased amounts of HIF-1 and a cytotoxic signature. Granzyme B-expressing T cells are concentrated at sites of skin tissue damage in CLE, suggesting relevance of this pathway to human disease.
Alicia J. Little, Ping-Min Chen, Matthew D. Vesely, Rahanna N. Khan, Jacob Fiedler, James Garritano, Fahrisa M. Islam, Jennifer M. McNiff, Joseph E. Craft
The proportions and phenotypes of immune cell subsets in peripheral blood undergo continual and dramatic remodeling throughout the human lifespan, which complicates efforts to identify disease-associated immune signatures in type 1 diabetes (T1D). We conducted cross-sectional flow cytometric immune profiling on peripheral blood from 826 individuals [stage 3 T1D (n=240), their first-degree relatives (n=310), those with >2 islet autoantibodies (n=24), and autoantibody negative healthy controls (n=252)]. We constructed an immune-age predictive model in healthy participants and observed accelerated immune aging in the T1D cohort (p<0.001). We used generalized additive models for location, shape, and scale (GAMLSS) to obtain age-corrected data for 192 flow cytometry and complete blood count readouts, which can be visualized in our interactive portal (ImmScape; https://ufdiabetes.shinyapps.io/ImmScape/); 46 parameters were significantly associated with age only, 25 with T1D only, and 23 with both age and T1D. Phenotypes associated with accelerated immunological aging in T1D included increased CXCR3+ and PD-1+ frequencies in naïve and memory T cell subsets, despite reduced PD-1 expression levels (MFI) on memory T cells. Phenotypes associated with T1D after age-correction were predictive of T1D status (AUROC=82.3%). Our findings demonstrate advanced immune aging in T1D and highlight disease-associated phenotypes for biomarker monitoring and therapeutic interventions.
Melanie R. Shapiro, Xiaoru Dong, Daniel J. Perry, James M. McNichols, Puchong Thirawatananond, Amanda L. Posgai, Leeana D. Peters, Keshav Motwani, Richard S. Musca, Andrew Muir, Patrick Concannon, Laura M. Jacobsen, Clayton E. Mathews, Clive H. Wasserfall, Michael J. Haller, Desmond A. Schatz, Mark A. Atkinson, Maigan A. Brusko, Rhonda Bacher, Todd M. Brusko
The intricate interplay between maternal immune response to SARS-CoV-2 and the transfer of protective factors to the fetus remains unclear. By analyzing mother:neonate dyads from second and third trimester SARS-CoV-2 infections, our study shows that neutralizing antibodies (NAbs) are infrequently detected in cord blood. We uncovered that this is due to impaired IgG-NAbs placental transfer in symptomatic infection and to the predominance of maternal SARS-CoV-2 NAbs of the IgA and IgM isotypes, which are prevented from crossing the placenta. Crucially, the balance between maternal antiviral response and transplacental transfer of IgG-NAbs appears to hinge on IL-6 and IL-10 produced in response to SARS-CoV-2 infection. In addition, asymptomatic maternal infection was associated with expansion of anti-SARS-CoV-2 IgM and NK cell frequency. Our findings identify a protective role for IgA/IgM-NAbs in gestational SARS-CoV-2 infection and open the possibility that the maternal immune response to SARS-CoV-2 infection might benefit the neonate in two ways, first by skewing maternal immune response towards immediate viral clearance, and second by endowing the neonate with protective mechanisms to curtail horizontal viral transmission in the critical post-natal period, via the priming of IgA/IgM-NAbs to be transferred by the breast milk and via NK cell expansion in the neonate.
Juliana Gonçalves, Magda Melro, Marta Alenquer, Catarina Araújo, Júlia Castro-Neves, Daniela Amaral-Silva, Filipe Ferreira, José S. Ramalho, Nádia Charepe, Fátima Serrano, Carlos Pontinha, Maria Joao Amorim, Helena Soares
Nitric oxide (NO) is a critical signaling molecule that has been implicated in the pathogenesis of neurocognitive diseases. Both excessive and insufficient NO production have been linked to pathology. Previously, we have shown that argininosuccinate lyase deficiency (ASLD) is a novel model system to investigate cell-autonomous, nitric oxide synthase (NOS)-dependent NO deficiency. Humans with ASLD are at increased risk for developing hyperammonemia due to a block in ureagenesis. However, natural history studies have shown that individuals with ASLD have multi-systemic disease including neurocognitive deficits that can be independent of ammonia. Here, using ASLD as a model of NO deficiency, we investigated the effects of NO on brain endothelial cells in vitro and the blood-brain barrier (BBB) in vivo. Knockdown of ASL in human brain microvascular endothelial cells (HBMECs) led to decreased transendothelial electrical resistance (TEER), indicative of increased cell permeability. Mechanistically, treatment with an NO donor or inhibition of Claudin-1 improved barrier integrity in ASL-deficient HBMECs. Furthermore, in vivo assessment of a hypomorphic mouse model of ASLD showed increased BBB leakage, which was partially rescued by NO supplementation. Our results suggest that ASL-mediated NO synthesis is required for proper maintenance of brain microvascular endothelial cell functions as well as BBB integrity.
Jordan Kho, Urszula Polak, Ming-Ming Jiang, John D. Odom, Jill V. Hunter, Saima M. Ali, Lindsay C. Burrage, Sandesh C.S. Nagamani, Robia G. Pautler, Hannah P. Thompson, Akihiko Urayama, Zixue Jin, Brendan Lee
Eosinophilic esophagitis (EoE) is a chronic gastrointestinal disorder characterized by food antigen–driven eosinophilic inflammation and hyperproliferation of esophageal mucosa. By utilizing a large-scale, proteomic screen of esophageal biopsies, we aimed to uncover molecular drivers of the disease. Proteomic analysis by liquid chromatography–tandem mass spectrometry identified 402 differentially expressed proteins (DEPs) that correlated with the EoE transcriptome. Immune cell–related proteins were among the most highly upregulated DEPs in EoE compared to controls, whereas proteins linked to epithelial differentiation were primarily downregulated. Notably, in the inflamed esophageal tissue, all six subunits of the minichromosome maintenance (MCM) complex, a DNA helicase essential for genomic DNA replication, were significantly upregulated at the gene and protein levels. Furthermore, treating esophageal epithelial cells with a known inhibitor of the MCM complex (ciprofloxacin) blocked esophageal epithelial proliferation. In a murine model of EoE driven by overexpression of IL-13, ciprofloxacin treatment decreased basal zone thickness and reduced dilated intercellular spaces by blocking the transition of the epithelial cell through the S-phase of the cell cycle. Collectively, a broad-spectrum proteomic screen has identified the involvement of the MCM complex in EoE and has highlighted MCM inhibitors as potential therapeutic agents for the disease.
Mark Rochman, Yrina Rochman, Julie M. Caldwell, Lydia Mack, John A Besse, Nathan P Manes, Sung Hwan Yoon, Tetsuo Shoda, Aleksandra Nita-Lazar, Marc Rothenberg
X-linked hypophosphatemia (XLH) is characterized by high serum fibroblast growth factor 23 (FGF23) levels, resulting in impaired 1,25 dihydroxyvitamin D (1,25D) production. Adults with XLH develop a painful mineralization of the tendon-bone attachment site (enthesis), called enthesopathy. Treatment of mice with XLH (Hyp) with 1,25D or an anti-FGF23 antibody, both of which increase 1,25D signaling, prevents enthesopathy. Therefore, we undertook studies to determine a role for impaired 1,25D action in enthesopathy development. Entheses from mice lacking vitamin D 1-alpha-hydroxylase (Cyp27b1) (C-/-) had a similar enthesopathy to Hyp mice, while deletion of Fgf23 in Hyp mice prevented enthesopathy and deletion of both Cyp27b1 and Fgf23 in mice resulted in enthesopathy, demonstrating that the impaired 1,25D action due to high FGF23 levels underlied XLH enthesopathy development. Like Hyp mice, enthesopathy in C-/- mice was observed by P14 and was prevented, but not reversed, with 1,25D therapy. Deletion of the vitamin D receptor in scleraxis-expressing cells resulted in enthesopathy, indicating 1,25D acted directly on enthesis cells to regulate enthesopathy development. These results showed that 1,25D signaling was necessary for normal post-natal enthesis maturation and played a role in XLH enthesopathy development. Optimizing 1,25D replacement in pediatric XLH patients is necessary to prevent enthesopathy.
Rakshya Rana, Jiana T. Baker, Melissa Sorsby, Supriya Jagga, Shreya Venkat, Shaza Almardini, Eva S. Liu
Darier, Hailey-Hailey, and Grover’s diseases are rare acantholytic skin diseases. While these diseases have different underlying causes, they share defects in cell-cell adhesion in the epidermis and desmosome organization. To better understand the underlying mechanisms leading to disease in these conditions we performed RNA-seq on lesional skin samples from patients. The transcriptomic profiles of Darier, Hailey-Hailey, and Grover’s disease were found to share a remarkable overlap, which did not extend to other common inflammatory skin diseases. Analysis of enriched pathways showed a shared upregulation in keratinocyte differentiation, and a decrease in cell adhesion and actin organization pathways in Darier, Hailey-Hailey, and Grover’s disease. Direct comparison to atopic dermatitis and psoriasis showed that the downregulation in actin organization pathways was a unique feature in the acantholytic skin diseases. Further, upstream regulator analysis suggested that a decrease in SRF/MRTF activity was responsible for the downregulation of actin organization pathways. Staining for MRTFA in lesional skin samples showed a decrease in nuclear MRTFA in patient skin compared to normal skin. These findings highlight the significant level of similarity in the transcriptome of Darier, Hailey-Hailey, and Grover’s disease, and identify decreases in actin organization pathways as a unique signature present in these conditions.
Quinn R. Roth-Carter, Hope E. Burks, Ziyou Ren, Jennifer L. Koetsier, Lam C. Tsoi, Paul W. Harms, Xianying Xing, Joseph Kirma, Robert M. Harmon, Lisa M. Godsel, Abbey L. Perl, Johann E. Gudjonsson, Kathleen J. Green
Rationale: Femoral atherosclerotic plaques are less inflammatory than carotid plaques histologically, but limited cell-level data exist regarding comparative immune landscapes and polarization at these sites. Objectives: We investigated intraplaque leukocyte phenotypes and transcriptional polarization in 49 total patients undergoing femoral (N=23) or carotid (N=26) endarterectomy using single-cell ribonucleic acid sequencing (scRNA-seq; N=13), flow cytometry (N=24), and immunohistochemistry (N=12). Findings: Comparative scRNA-seq of CD45 positive-selected leukocytes from femoral (N=9; 35265 cells) and carotid (N=4; 30655 cells) plaque revealed distinct transcriptional profiles. Inflammatory foam cell-like macrophages and monocytes comprised 2.5- to 4-fold higher proportions of myeloid cells in carotid plaques, whereas non-inflammatory foam cell-like macrophages and LYVE1-overexpressing resident-like macrophages comprised 3.5- to 9-fold higher proportions of myeloid cells in femoral plaque (p<0.001 for all). A significant comparative excess of CCR2+ macrophages in carotid versus femoral plaque was observed by flow cytometry in a separate validation cohort. B cells were more prevalent and exhibited a comparatively anti-inflammatory profile in femoral plaque, whereas cytotoxic CD8+ T cells were more prevalent in carotid plaque. Conclusion: Human femoral plaques exhibit distinct macrophage profiles and diminished CD8+ T cell populations compared with carotid plaques. Experimental models elucidating determinants of plaque site-specific cell polarization cues are warranted.
Joshua Slysz, Arjun Sinha, Matthew DeBerge, Shalini Singh, Harris Avgousti, Inhyeok Lee, Kristofor Glinton, Reina Nagasaka, Prarthana J. Dalal, Shaina J. Alexandria, Ching Man Wai, Ricardo Tellez, Mariavittoria Vescovo, Ashwin Sunderraj, Xinkun Wang, Matthew J. Schipma, Ryan K Sisk, Rishab Gulati, Jenifer Vallejo, Ryosuke Saigusa, Donald M. Lloyd-Jones, Jon Lomasney, Samuel E. Weinberg, Karen J. Ho, Klaus Ley, Chiara Giannarelli, Edward B. Thorp, Matthew J. Feinstein
Pansclerotic morphea (PSM) is a rare, devastating disease characterized by extensive soft tissue fibrosis, secondary contractions, and significant morbidity. PSM pathogenesis is unknown, and aggressive immunosuppressive treatments rarely slow disease progression. We aimed to characterize molecular mechanisms driving PSM and identify therapeutically targetable pathways by performing single-cell and spatial RNA-sequencing on lesional and non-lesional skin biopsies of a PSM patient 12-months apart and 6 healthy controls. We then validated using immunostaining and in vitro approaches.Fibrotic skin was characterized by prominent type-II IFN response, accompanied by infiltrating myeloid, B-cells, and T-cells, which were the main IFN-γ source. We identified unique CXCL9+ fibroblasts enriched in PSM, characterized by increased chemokine expression, including CXCL9, CXCL10, and CCL2. CXCL9+ fibroblasts were related to profibrotic COL8A1+ myofibroblasts, which had enriched TGF-β response. In vitro, TGF-β and IFN-γ synergistically increased CXCL9 and CXCL10 expression, contributing to the perpetuation of IFN-γ responses. Further, cell-cell interaction analyses revealed cDC2B dendritic cells as a key communication hub between CXCL9+ fibroblasts and COL8A1+ myofibroblasts. These results define PSM as an inflammation-driven condition centered on type-II IFN responses. This work identified key pathogenic circuits between T-cells, cDC2Bs, and myofibroblasts, and suggests JAK1/2 inhibition is a potential therapeutic option in PSM.
Enze Xing, Feiyang Ma, Rachael Wasikowski, Allison C. Billi, Mehrnaz Gharaee-Kermani, Jennifer Fox, Craig Dobry, Amanda Victory, Mrinal Sarkar, Xianying Xing, Olesya Plazyo, Henry W. Chen, Grant C. Barber, Heidi Jacobe, Pei-Suen Tsou, Robert L. Modlin, John Varga, J. Michelle Kahlenberg, Lam C. Tsoi, Johann E. Gudjonsson, Dinesh Khanna
Intestinal mucins play an essential role in the defense against bacterial invasion and the maintenance of gut microbiota, which is instrumental in the regulation of host immune systems; hence, its dysregulation is a hallmark of metabolic disease and intestinal inflammation. However, the mechanism by which intestinal mucins control the gut microbiota as well as disease phenotypes remains nebulous. Herein, we report that N-acetylglucosamine (GlcNAc)-6-O-sulfation of O-glycans on intestinal mucins performs a protective role against obesity and intestinal inflammation. Chst4-/- mice, lacking GlcNAc-6-O-sulfation of the mucin O-glycans, showed significant weight gain and increased susceptibility to dextran sodium sulfate-induced colitis as well as colitis-associated cancer accompanied by significantly reduced immunoglobulin A (IgA) production caused by impaired T follicular helper cell-mediated IgA response. Interestingly, the protective effects of GlcNAc-6-O-sulfation against obesity and intestinal inflammation depend on the gut microbiota, evidenced by the modulation of the gut microbiota by co-housing or microbiota transplantation reversing disease phenotypes and IgA production. Collectively, our findings provide novel insight into the significance of host glycosylation, more specifically GlcNAc-6-O-sulfation on intestinal mucins, in protecting against obesity and intestinal inflammation via regulation of the gut microbiota.
Hirohito Abo, Aoi Muraki, Akihito Harusato, Tetsuya Imura, Maki Suzuki, Kohta Takahashi, Timothy L. Denning, Hiroto Kawashima
Optimal lung repair and regeneration is essential for recovery from viral infections including influenza A virus (IAV). We have previously demonstrated that acute inflammation and mortality induced by IAV is under circadian control. However, it is not known if the influence of the circadian clock persists beyond the acute outcomes. Here, we utilize the UK Biobank to demonstrate an association between poor circadian rhythms and morbidity from lower respiratory tract infections including the need for hospitalization and post-discharge mortality; this persists even after adjusting for common confounding factors. Further, we use a combination of lung organoid assays, single cell RNA sequencing (Sc-seq) and IAV infection in different models of clock disruption to investigate the role of the circadian clock in lung repair and regeneration. We show for the first time that lung organoids have a functional circadian clock, and the disruption of this clock impairs regenerative capacity. Finally, we find that the circadian clock acts through distinct pathways in mediating lung regeneration- in tracheal cells via the Wnt/β-catenin pathway and through IL1β in alveolar epithelial cells. We speculate, that adding a circadian dimension to the critical process of lung repair and regeneration will lead to novel therapies and improve outcomes.
Amruta Naik, Kaitlyn M. Forrest, Oindrila Paul, Yasmine Issah, Utham Kashyap Valekunja, Soon Yew Tang, Akhilesh B. Reddy, Elizabeth J. Hennessy, Thomas G. Brooks, Fatima N. Chaudhry, Apoorva Babu, Michael P. Morley, Jarod A. Zepp, Gregory R. Grant, Garret FitzGerald, Amita Sehgal, G. Scott Worthen, David B. Frank, Edward E. Morrisey, Shaon Sengupta
Gene therapy is under advanced clinical development for several lysosomal storage disorders. Pompe disease, a debilitating neuromuscular illness that affects infants, children, and adults with different degrees of severity, is caused by a deficiency of lysosomal glycogen-degrading enzyme acid alpha-glucosidase (GAA). Here, we demonstrated that adeno-associated virus (AAV9)-mediated systemic gene transfer fully reversed glycogen storage in all key therapeutic targets - skeletal and cardiac muscles, the diaphragm, and the central nervous system (CNS) - in both young and severely affected old Gaa knockout mice. Furthermore, the therapy reversed secondary cellular abnormalities in skeletal muscle, such as autophagy and mTORC1/AMPK signaling. We used a newly developed AAV9 vector encoding a chimeric human GAA protein with enhanced uptake and secretion to facilitate efficient spread of the expressed protein among multiple target tissues. These results lay the groundwork for future clinical development strategy in Pompe disease.
Naresh K Meena, Davide Randazzo, Nina Raben, Rosa Puertollano
Lysine-specific demethylase 1 (LSD1) is a histone demethylase that promotes stemness and cancer cell survival, including in prostate cancer. Most prostate malignancies are adenocarcinomas with luminal differentiation. However, some tumors undergo cellular reprogramming to a more lethal subset termed neuroendocrine prostate cancer (NEPC) with neuronal differentiation. The frequency of NEPC is increasing since widespread use of potent androgen receptor signaling inhibitors. Currently, there are no effective treatments for NEPC. We previously determined that LSD1 promotes survival of prostate adenocarcinoma tumors. However, the role of LSD1 in NEPC is unknown. Here, we determined that LSD1 is highly upregulated in NEPC vs. adenocarcinoma patient tumors. LSD1 suppression with RNAi or allosteric LSD1 inhibitors—but not catalytic inhibitors—reduced NEPC cell survival. RNA-seq analysis revealed that LSD1 represses pathways linked to luminal differentiation, and TP53 was the top reactivated pathway. We confirmed that LSD1 suppressed the TP53 pathway by reducing TP53 occupancy at target genes while LSD1’s catalytic function was dispensable for this effect. Mechanistically, LSD1 inhibition disrupted LSD1-HDAC interactions, increasing histone acetylation at TP53 targets. Finally, LSD1 inhibition suppressed NEPC tumor growth in vivo. These findings suggest that blocking LSD1’s non-catalytic function may be a promising new treatment strategy for NEPC.
Anbarasu Kumaraswamy, Zhi Duan, Diana Flores, Chao Zhang, Archana Sehrawat, Ya-Mei Hu, Olivia A. Swaim, Eva Rodansky, William K. Storck, Joshua A. Kuleape, Karan Bedi, Rahul Mannan, Xiao-Ming Wang, Aaron M. Udager, Visweswaran Ravikumar, Armand Bankhead III, Ilsa Coleman, John K. Lee, Colm Morrissey, Peter S. Nelson, Arul Chinnaiyan, Arvind Rao, Zheng Xia, Joel A. Yates, Joshi J. Alumkal
Reactive oxygen species (ROS) are natural products of mitochondrial oxidative metabolism and oxidative protein folding. ROS levels must be well controlled as elevated ROS has been shown to have deleterious effects on osteoblasts. Moreover, excessive ROS is thought to underly many of the skeletal phenotypes associated with aging and sex steroid deficiency in mice and humans. The mechanisms by which osteoblasts regulate ROS and how ROS inhibits osteoblasts are not well understood. Here, we demonstrate that de novo glutathione (GSH) biosynthesis is essential to neutralize ROS and establish a pro-osteogenic REDOX environment. Using a multifaceted approach, we demonstrate that reducing GSH biosynthesis leads to acute degradation of RUNX2, impaired osteoblast differentiation and reduced bone formation. Conversely, reducing ROS using Catalase enhances RUNX2 stability and promotes osteoblast differentiation and bone formation when GSH biosynthesis is limited. Highlighting the therapeutic implications of these findings, in utero antioxidant therapy stabilizes RUNX2 and improves bone development in the Runx2+/- haploinsufficient mouse model of human Cleidocranial Dysplasia. Thus, our data establish RUNX2 as a molecular sensor of the osteoblast REDOX environment and mechanistically clarifies how ROS negatively impacts osteoblast differentiation and bone formation.
Guoli Hu, Yilin Yu, Deepika Sharma, Shondra M. Pruett-Miller, Yinshi Ren, Guo-Fang Zhang, Courtney M. Karner