Sorbitol reduction via govorestat ameliorates synaptic dysfunction and neurodegeneration in sorbitol dehydrogenase deficiency
Zhu and Lobato et al. uncovered the pathology of hereditary neuropathy caused by sorbitol dehydrogenase deficiency and provided a potential treatment strategy by using an aldose reductase inhibitor, AT-007 (govorestat). The cover image depicts the Drosophila flight muscle neuromuscular junctions immunolabeled with a synaptic active zone marker (Bruchpilot) and a neuronal membrane marker (horseradish peroxidase). Image credit: Tijana Canic, Yi Zhu, and Amanda Lobato.
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Research Articles
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Abstract
The intake of dietary phosphate far exceeds recommended levels; however, the long-term health consequences remain relatively unknown. Here, the chronic physiological response to sustained elevated and reduced dietary phosphate consumption was investigated in mice. Although serum phosphate levels were brought into homeostatic balance, the prolonged intake of a high-phosphate diet dramatically and negatively impacted bone volume; generated a sustained increase in the phosphate responsive circulating factors FGF23, PTH, osteopontin and osteocalcin; and produced a chronic low-grade inflammatory state in the BM, marked by increased numbers of T cells expressing IL-17a, RANKL, and TNF-α. In contrast, a low-phosphate diet preserved trabecular bone while increasing cortical bone volume over time, and it reduced inflammatory T cell populations. Cell-based studies identified a direct response of T cells to elevated extracellular phosphate. Neutralizing antibodies against proosteoclastic cytokines RANKL, TNF-α, and IL-17a blunted the high-phosphate diet–induced bone loss identifying bone resorption as a regulatory mechanism. Collectively, this study illuminates that habitual consumption of a high-phosphate diet in mice induces chronic inflammation in bone, even in the absence of elevated serum phosphate. Furthermore, the study supports the concept that a reduced phosphate diet may be a simple yet effective strategy to reduce inflammation and improve bone health during aging.
Authors
Joseph L. Roberts, Mingcan Yu, Manjula Viggeswarapu, Jamie L. Arnst, Roberto Pacifici, George R. Beck Jr
×Abstract
The pathogenesis of the marked pulmonary microvasculature injury, a distinguishing feature of COVID-19 acute respiratory distress syndrome (COVID-ARDS), remains unclear. Implicated in the pathophysiology of diverse diseases characterized by endothelial damage, including ARDS and ischemic cardiovascular disease, ceramide and in particular palmitoyl ceramide (C16:0-ceramide) may be involved in the microvascular injury in COVID-19. Using deidentified plasma and lung samples from COVID-19 patients, ceramide profiling by mass spectrometry was performed. Compared with healthy individuals, a specific 3-fold C16:0-ceramide elevation in COVID-19 patient plasma was identified. Compared with age-matched controls, autopsied lungs of individuals succumbing to COVID-ARDS displayed a massive 9-fold C16:0-ceramide elevation and exhibited a previously unrecognized microvascular ceramide-staining pattern and markedly enhanced apoptosis. In COVID-19 plasma and lungs, the C16-ceramide/C24-ceramide ratios were increased and reversed, respectively, consistent with increased risk of vascular injury. Indeed, exposure of primary human lung microvascular endothelial cell monolayers to C16:0-ceramide–rich plasma lipid extracts from COVID-19, but not healthy, individuals led to a significant decrease in endothelial barrier function. This effect was phenocopied by spiking healthy plasma lipid extracts with synthetic C16:0-ceramide and was inhibited by treatment with ceramide-neutralizing monoclonal antibody or single-chain variable fragment. These results indicate that C16:0-ceramide may be implicated in the vascular injury associated with COVID-19.
Authors
Irina Petrache, Elisabet Pujadas, Aditya Ganju, Karina A. Serban, Alexander Borowiec, Beatrice Babbs, Irina A. Bronova, Nicholas Egersdorf, Patrick S. Hume, Khushboo Goel, William J. Janssen, Evgeny V. Berdyshev, Carlos Cordon-Cardo, Richard Kolesnick
×Abstract
The prevalence of obesity and type 2 diabetes is growing at an alarming rate, including among pregnant women. Low-calorie sweeteners (LCSs) have increasingly been used as an alternative to sugar to deliver a sweet taste without the excessive caloric load. However, there is little evidence regarding their biological effects, particularly during development. Here, we used a mouse model of maternal LCS consumption to explore the impact of perinatal LCS exposure on the development of neural systems involved in metabolic regulation. We report that adult male, but not female, offspring from both aspartame- and rebaudioside A–exposed dams displayed increased adiposity and developed glucose intolerance. Moreover, maternal LCS consumption reorganized hypothalamic melanocortin circuits and disrupted parasympathetic innervation of pancreatic islets in male offspring. We then identified phenylacetylglycine (PAG) as a unique metabolite that was upregulated in the milk of LCS-fed dams and the serum of their pups. Furthermore, maternal PAG treatment recapitulated some of the key metabolic and neurodevelopmental abnormalities associated with maternal LCS consumption. Together, our data indicate that maternal LCS consumption has enduring consequences on the offspring’s metabolism and neural development and that these effects are likely to be mediated through the gut microbial co-metabolite PAG.
Authors
Soyoung Park, Amine M. Belfoul, Marialetizia Rastelli, Alice Jang, Magali Monnoye, Hosung Bae, Anna Kamitakahara, Patrick Giavalisco, Shan Sun, Pierre-Yves Barelle, Jasmine Plows, Cholsoon Jang, Anthony Fodor, Michael I. Goran, Sebastien G. Bouret
×Abstract
Although thymidylate synthase (TYMS) inhibitors have served as components of chemotherapy regimens, the currently available inhibitors induce TYMS overexpression or alter folate transport/metabolism feedback pathways that tumor cells exploit for drug resistance, limiting overall benefit. Here we report a small molecule TYMS inhibitor that i) exhibited enhanced antitumor activity as compared with current fluoropyrimidines and antifolates without inducing TYMS overexpression, ii) is structurally distinct from classical antifolates, iii) extended survival in both pancreatic xenograft tumor models and an hTS/Ink4a/Arf null genetically engineered mouse tumor model, and iv) is well tolerated with equal efficacy using either intraperitoneal or oral administration. Mechanistically, we verify the compound is a multifunctional nonclassical antifolate, and using a series of analogs, we identify structural features allowing direct TYMS inhibition while maintaining the ability to inhibit dihydrofolate reductase. Collectively, this work identifies nonclassical antifolate inhibitors that optimize inhibition of thymidylate biosynthesis with a favorable safety profile, highlighting the potential for enhanced cancer therapy.
Authors
Maria V. Guijarro, Patrick C. Kellish, Peter E. Dib, Nicholas G. Paciaroni, Akbar Nawab, Jacob Andring, Lidia Kulemina, Nicholas V. Borrero, Carlos Modenutti, Michael Feely, Elham Nasri, Robert P. Seifert, Xiaoping Luo, Richard L. Bennett, Daniil Shabashvili, Jonathan D. Licht, Robert McKenna, Adrian Roitberg, Robert W. Huigens III, Frederic J. Kaye, Maria Zajac-Kaye
×Abstract
Mesenchymal chondrosarcoma affects adolescents and young adults, and most cases usually have the HEY1::NCOA2 fusion gene. However, the functional role of HEY1-NCOA2 in the development and progression of mesenchymal chondrosarcoma remains largely unknown. This study aimed to clarify the functional role of HEY1-NCOA2 in transformation of the cell of origin and induction of typical biphasic morphology of mesenchymal chondrosarcoma. We generated a mouse model for mesenchymal chondrosarcoma by introducing HEY1-NCOA2 into mouse embryonic superficial zone (eSZ) followed by subcutaneous transplantation into nude mice. HEY1-NCOA2 expression in eSZ cells successfully induced subcutaneous tumors in 68.9% of recipients, showing biphasic morphologies and expression of Sox9, a master regulator of chondrogenic differentiation. ChIP sequencing analyses indicated frequent interaction between HEY1-NCOA2 binding peaks and active enhancers. Runx2, which is important for differentiation and proliferation of the chondrocytic lineage, is invariably expressed in mouse mesenchymal chondrosarcoma, and interaction between HEY1-NCOA2 and Runx2 is observed using NCOA2 C-terminal domains. Although Runx2 knockout resulted in significant delay in tumor onset, it also induced aggressive growth of immature small round cells. Runx3, which is also expressed in mesenchymal chondrosarcoma and interacts with HEY1-NCOA2, replaced the DNA-binding property of Runx2 only in part. Treatment with the HDAC inhibitor panobinostat suppressed tumor growth both in vitro and in vivo, abrogating expression of genes downstream of HEY1-NCOA2 and Runx2. In conclusion, HEY1::NCOA2 expression modulates the transcriptional program in chondrogenic differentiation, affecting cartilage-specific transcription factor functions.
Authors
Miwa Tanaka, Mizuki Homme, Yasuyo Teramura, Kohei Kumegawa, Yukari Yamazaki, Kyoko Yamashita, Motomi Osato, Reo Maruyama, Takuro Nakamura
×Abstract
Elevated blood glucose levels, or hyperglycemia, can increase brain excitability and amyloid-β (Aβ) release, offering a mechanistic link between type 2 diabetes and Alzheimer’s disease (AD). Since the cellular mechanisms governing this relationship are poorly understood, we explored whether ATP-sensitive potassium (KATP) channels, which couple changes in energy availability with cellular excitability, play a role in AD pathogenesis. First, we demonstrate that KATP channel subunits Kir6.2/KCNJ11 and SUR1/ABCC8 were expressed on excitatory and inhibitory neurons in the human brain, and cortical expression of KCNJ11 and ABCC8 changed with AD pathology in humans and mice. Next, we explored whether eliminating neuronal KATP channel activity uncoupled the relationship between metabolism, excitability, and Aβ pathology in a potentially novel mouse model of cerebral amyloidosis and neuronal KATP channel ablation (i.e., amyloid precursor protein [APP]/PS1 Kir6.2–/– mouse). Using both acute and chronic paradigms, we demonstrate that Kir6.2-KATP channels are metabolic sensors that regulate hyperglycemia-dependent increases in interstitial fluid levels of Aβ, amyloidogenic processing of APP, and amyloid plaque formation, which may be dependent on lactate release. These studies identify a potentially new role for Kir6.2-KATP channels in AD and suggest that pharmacological manipulation of Kir6.2-KATP channels holds therapeutic promise in reducing Aβ pathology in patients with diabetes or prediabetes.
Authors
John Grizzanti, William R. Moritz, Morgan C. Pait, Molly Stanley, Sarah D. Kaye, Caitlin M. Carroll, Nicholas J. Constantino, Lily J. Deitelzweig, James A. Snipes, Derek Kellar, Emily E. Caesar, Ryan J. Pettit-Mee, Stephen M. Day, Jonathon P. Sens, Noelle I. Nicol, Jasmeen Dhillon, Maria S. Remedi, Drew D. Kiraly, Celeste M. Karch, Colin G. Nichols, David M. Holtzman, Shannon L. Macauley
×Abstract
Patients with peripheral artery disease (PAD) and diabetes compose a high-risk population for development of critical limb ischemia (CLI) and amputation, although the underlying mechanisms remain poorly understood. Comparison of dysregulated microRNAs from diabetic patients with PAD and diabetic mice with limb ischemia revealed the conserved microRNA, miR–130b-3p. In vitro angiogenic assays demonstrated that miR-130b rapidly promoted proliferation, migration, and sprouting in endothelial cells (ECs), whereas miR-130b inhibition exerted antiangiogenic effects. Local delivery of miR-130b mimics into ischemic muscles of diabetic mice (db/db) following femoral artery ligation (FAL) promoted revascularization by increasing angiogenesis and markedly improved limb necrosis and amputation. RNA-Seq and gene set enrichment analysis from miR-130b–overexpressing ECs revealed the BMP/TGF-β signaling pathway as one of the top dysregulated pathways. Accordingly, overlapping downregulated transcripts from RNA-Seq and miRNA prediction algorithms identified that miR-130b directly targeted and repressed the TGF-β superfamily member inhibin-β-A (INHBA). miR-130b overexpression or siRNA-mediated knockdown of INHBA induced IL-8 expression, a potent angiogenic chemokine. Lastly, ectopic delivery of silencer RNAs (siRNA) targeting Inhba in db/db ischemic muscles following FAL improved revascularization and limb necrosis, recapitulating the phenotype of miR-130b delivery. Taken together, a miR-130b/INHBA signaling axis may provide therapeutic targets for patients with PAD and diabetes at risk of developing CLI.
Authors
Henry S. Cheng, Daniel Pérez-Cremades, Rulin Zhuang, Anurag Jamaiyar, Winona Wu, Jingshu Chen, Aspasia Tzani, Lauren Stone, Jorge Plutzky, Terence E. Ryan, Philip P. Goodney, Mark A. Creager, Marc S. Sabatine, Marc P. Bonaca, Mark W. Feinberg
×Abstract
Muscular dystrophies make up a group of genetic neuromuscular disorders that involve severe muscle wasting. TGF-β–activated kinase 1 (TAK1) is an important signaling protein that regulates cell survival, growth, and inflammation. TAK1 has been recently found to promote myofiber growth in the skeletal muscle of adult mice. However, the role of TAK1 in muscle diseases remains poorly understood. In the present study, we have investigated how TAK1 affects the progression of dystrophic phenotype in the mdx mouse model of Duchenne muscular dystrophy (DMD). TAK1 is highly activated in the dystrophic muscle of mdx mice during the peak necrotic phase. While targeted inducible inactivation of TAK1 inhibits myofiber injury in young mdx mice, it results in reduced muscle mass and contractile function. TAK1 inactivation also causes loss of muscle mass in adult mdx mice. By contrast, forced activation of TAK1 through overexpression of TAK1 and TAB1 induces myofiber growth without having any deleterious effect on muscle histopathology. Collectively, our results suggest that TAK1 is a positive regulator of skeletal muscle mass and that targeted regulation of TAK1 can suppress myonecrosis and ameliorate disease progression in DMD.
Authors
Anirban Roy, Tatiana E. Koike, Aniket S. Joshi, Meiricris Tomaz da Silva, Kavya Mathukumalli, Mingfu Wu, Ashok Kumar
×Abstract
Methotrexate (MTX) is a standard, first-line therapy for rheumatoid arthritis (RA); however, its precise mechanisms of action other than antifolate activity are largely unknown. We performed DNA microarray analyses of CD4+ T cells in patients with RA before and after MTX treatment and found that TP63 was the most significantly downregulated gene after MTX treatment. TAp63, an isoform of TP63, was highly expressed in human IL-17–producing Th (Th17) cells and was suppressed by MTX in vitro. Murine TAp63 was expressed at high levels in Th cells and at lower levels in thymus-derived Treg cells. Importantly, TAp63 knockdown in murine Th17 cells ameliorated the adoptive transfer arthritis model. RNA-Seq analyses of human Th17 cells overexpressing TAp63 and those with TAp63 knockdown identified FOXP3 as a possible TAp63 target gene. TAp63 knockdown in CD4+ T cells cultured under Th17 conditions with low-dose IL-6 increased Foxp3 expression, suggesting that TAp63 balances Th17 cells and Treg cells. Mechanistically, TAp63 knockdown in murine induced Treg (iTreg) cells promoted hypomethylation of conserved noncoding sequence 2 (CNS2) of the Foxp3 gene and enhanced the suppressive function of iTreg cells. Reporter analyses revealed that TAp63 suppressed the activation of the Foxp3 CNS2 enhancer. Collectively, TAp63 suppresses Foxp3 expression and exacerbates autoimmune arthritis.
Authors
Kensuke Suga, Akira Suto, Shigeru Tanaka, Yutaka Sugawara, Takahiro Kageyama, Junichi Ishikawa, Yoshie Sanayama, Kei Ikeda, Shunsuke Furuta, Shin-Ichiro Kagami, Arifumi Iwata, Koichi Hirose, Kotaro Suzuki, Osamu Ohara, Hiroshi Nakajima
×Abstract
Central glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) signaling is critical in GIP-based therapeutics’ ability to lower body weight, but pathways leveraged by GIPR pharmacology in the brain remain incompletely understood. We explored the role of Gipr neurons in the hypothalamus and dorsal vagal complex (DVC) — brain regions critical to the control of energy balance. Hypothalamic Gipr expression was not necessary for the synergistic effect of GIPR/GLP-1R coagonism on body weight. While chemogenetic stimulation of both hypothalamic and DVC Gipr neurons suppressed food intake, activation of DVC Gipr neurons reduced ambulatory activity and induced conditioned taste avoidance, while there was no effect of a short-acting GIPR agonist (GIPRA). Within the DVC, Gipr neurons of the nucleus tractus solitarius (NTS), but not the area postrema (AP), projected to distal brain regions and were transcriptomically distinct. Peripherally dosed fluorescent GIPRAs revealed that access was restricted to circumventricular organs in the CNS. These data demonstrate that Gipr neurons in the hypothalamus, AP, and NTS differ in their connectivity, transcriptomic profile, peripheral accessibility, and appetite-controlling mechanisms. These results highlight the heterogeneity of the central GIPR signaling axis and suggest that studies into the effects of GIP pharmacology on feeding behavior should consider the interplay of multiple regulatory pathways.
Authors
Alice Adriaenssens, Johannes Broichhagen, Anne de Bray, Julia Ast, Annie Hasib, Ben Jones, Alejandra Tomas, Natalie Figueredo Burgos, Orla Woodward, Jo Lewis, Elisabeth O’Flaherty, Kimberley El, Canqi Cui, Norio Harada, Nobuya Inagaki, Jonathan Campbell, Daniel Brierley, David J. Hodson, Ricardo Samms, Fiona Gribble, Frank Reimann
×Abstract
Sorbitol dehydrogenase (SORD) deficiency has been identified as the most frequent autosomal recessive form of hereditary neuropathy. Loss of SORD causes high sorbitol levels in tissues due to the inability to convert sorbitol to fructose in the 2-step polyol pathway, leading to degenerative neuropathy. The underlying mechanisms of sorbitol-induced degeneration have not been fully elucidated, and no current FDA-approved therapeutic options are available to reduce sorbitol levels in the nervous system. Here, in a Drosophila model of SORD deficiency, we showed synaptic degeneration in the brain, neurotransmission defect, locomotor impairment, and structural abnormalities in the neuromuscular junctions. In addition, we found reduced ATP production in the brain and ROS accumulation in the CNS and muscle, indicating mitochondrial dysfunction. Applied Therapeutics has developed a CNS-penetrant next-generation aldose reductase inhibitor (ARI), AT-007 (govorestat), which inhibits the conversion of glucose to sorbitol. AT-007 significantly reduced sorbitol levels in patient-derived fibroblasts, induced pluripotent stem cell–derived (iPSC-derived) motor neurons, and Drosophila brains. AT-007 feeding in Sord-deficient Drosophila mitigated synaptic degeneration and significantly improved synaptic transduction, locomotor activity, and mitochondrial function. Moreover, AT-007 treatment significantly reduced ROS accumulation in Drosophila CNS, muscle, and patient-derived fibroblasts. These findings uncover the molecular and cellular pathophysiology of SORD neuropathy and provide a potential treatment strategy for patients with SORD deficiency.
Authors
Yi Zhu, Amanda G. Lobato, Adriana P. Rebelo, Tijana Canic, Natalie Ortiz-Vega, Xianzun Tao, Sheyum Syed, Christopher Yanick, Mario Saporta, Michael Shy, Riccardo Perfetti, Shoshana Shendelman, Stephan Züchner, R. Grace Zhai
×Abstract
Viral illnesses like SARS-CoV-2 have pathologic effects on nonrespiratory organs in the absence of direct viral infection. We injected mice with cocktails of rodent equivalents of human cytokine storms resulting from SARS-CoV-2/COVID-19 or rhinovirus common cold infection. At low doses, COVID-19 cocktails induced glomerular injury and albuminuria in zinc fingers and homeoboxes 2 (Zhx2) hypomorph and Zhx2+/+ mice to mimic COVID-19–related proteinuria. Common Cold cocktail induced albuminuria selectively in Zhx2 hypomorph mice to model relapse of minimal change disease, which improved after depletion of TNF-α, soluble IL-4Rα, or IL-6. The Zhx2 hypomorph state increased cell membrane to nuclear migration of podocyte ZHX proteins in vivo (both cocktails) and lowered phosphorylated STAT6 activation (COVID-19 cocktail) in vitro. At higher doses, COVID-19 cocktails induced acute heart injury, myocarditis, pericarditis, acute liver injury, acute kidney injury, and high mortality in Zhx2+/+ mice, whereas Zhx2 hypomorph mice were relatively protected, due in part to early, asynchronous activation of STAT5 and STAT6 pathways in these organs. Dual depletion of cytokine combinations of TNF-α with IL-2, IL-13, or IL-4 in Zhx2+/+ mice reduced multiorgan injury and eliminated mortality. Using genome sequencing and CRISPR/Cas9, an insertion upstream of ZHX2 was identified as a cause of the human ZHX2 hypomorph state.
Authors
Maria Del Nogal Avila, Ranjan Das, Joubert Kharlyngdoh, Eduardo Molina-Jijon, Hector Donoro Blazquez, Stéphanie Gambut, Michael Crowley, David K. Crossman, Rasheed A. Gbadegesin, Sunveer S. Chugh, Sunjeet S. Chugh, Carmen Avila-Casado, Camille Macé, Lionel C. Clement, Sumant S. Chugh
×Abstract
Elderly individuals frequently report cognitive decline, while various studies indicate hippocampal functional declines with advancing age. Hippocampal function is influenced by ghrelin through hippocampus-expressed growth hormone secretagogue receptor (GHSR). Liver-expressed antimicrobial peptide 2 (LEAP2) is an endogenous GHSR antagonist that attenuates ghrelin signaling. Here, we measured plasma ghrelin and LEAP2 levels in a cohort of cognitively normal individuals older than 60 and found that LEAP2 increased with age while ghrelin (also referred to in literature as “acyl-ghrelin”) marginally declined. In this cohort, plasma LEAP2/ghrelin molar ratios were inversely associated with Mini-Mental State Examination scores. Studies in mice showed an age-dependent inverse relationship between plasma LEAP2/ghrelin molar ratio and hippocampal lesions. In aged mice, restoration of the LEAP2/ghrelin balance to youth-associated levels with lentiviral shRNA Leap2 downregulation improved cognitive performance and mitigated various age-related hippocampal deficiencies such as CA1 region synaptic loss, declines in neurogenesis, and neuroinflammation. Our data collectively suggest that LEAP2/ghrelin molar ratio elevation may adversely affect hippocampal function and, consequently, cognitive performance; thus, it may serve as a biomarker of age-related cognitive decline. Moreover, targeting LEAP2 and ghrelin in a manner that lowers the plasma LEAP2/ghrelin molar ratio could benefit cognitive performance in elderly individuals for rejuvenation of memory.
Authors
Jing Tian, Lan Guo, Tienju Wang, Kun Jia, Russell H. Swerdlow, Jeffrey M. Zigman, Heng Du
×Abstract
Familial exudative vitreoretinopathy (FEVR) is a complex hereditary eye disorder characterized by incomplete development of the retinal vasculature, which thereby affects retinal angiogenesis. But the genetic factors contributing to FEVR’s development or pathogenesis remain elusive. In a Chinese family with FEVR with 19 members, by using whole-exome sequencing, we identified a candidate disease-causing DNA variant in sorting nexin 31 (SNX31) (c.963delG; p. Trp321Cys), which results in a frameshift mutation. We studied the biochemical mechanism of this mutation and determined that it is deficient in β1-integrin binding and stability. The SNX31 c.963delG point mutation mouse model (SNX31m/m) was constructed with CRISPR/Cas9 technology. At 2–4 months of age, SNX31m/m mice showed fundus phenotypes similar to FEVR-like changes, including vascular leakage and retinal atrophy. Moreover, we found that VEGF and apoptotic pathways were involved in these ocular phenotypes. Hence, our study extended the FEVR mutation spectrum to include SNX31. These findings expanded our understanding of the molecular pathogenesis of FEVR and may facilitate the development of methods for the diagnosis and prevention of FEVR.
Authors
Ningda Xu, Yi Cai, Jiarui Li, Tianchang Tao, Caifei Liu, Yan Shen, Xiaoxin Li, Leiliang Zhang, Mingwei Zhao, Xuan Shi, Jing Li, Lvzhen Huang
×Abstract
Neutrophilic inflammation characterizes several respiratory viral infections, including COVID-19–related acute respiratory distress syndrome, although its contribution to disease pathogenesis remains poorly understood. Blood and airway immune cells from 52 patients with severe COVID-19 were phenotyped by flow cytometry. Samples and clinical data were collected at 2 separate time points to assess changes during ICU stay. Blockade of type I interferon and interferon-induced protein with tetratricopeptide repeats 3 (IFIT3) signaling was performed in vitro to determine their contribution to viral clearance in A2 neutrophils. We identified 2 neutrophil subpopulations (A1 and A2) in the airway compartment, where loss of the A2 subset correlated with increased viral burden and reduced 30-day survival. A2 neutrophils exhibited a discrete antiviral response with an increased interferon signature. Blockade of type I interferon attenuated viral clearance in A2 neutrophils and downregulated IFIT3 and key catabolic genes, demonstrating direct antiviral neutrophil function. Knockdown of IFIT3 in A2 neutrophils led to loss of IRF3 phosphorylation, with consequent reduced viral catabolism, providing the first discrete mechanism to our knowledge of type I interferon signaling in neutrophils. The identification of this neutrophil phenotype and its association with severe COVID-19 outcomes emphasizes its likely importance in other respiratory viral infections and potential for new therapeutic approaches in viral illness.
Authors
Camilla Margaroli, Timothy Fram, Nirmal S. Sharma, Siddharth B. Patel, Jennifer Tipper, Sarah W. Robison, Derek W. Russell, Seth D. Fortmann, Mudassir M. Banday, Yixel Soto-Vazquez, Tarek Abdalla, Sawanan Saitornuang, Matthew C. Madison, Sixto M. Leal Jr., Kevin S. Harrod, Nathaniel B. Erdmann, Amit Gaggar
×Abstract
ASXL1 (additional sex combs–like 1) plays key roles in epigenetic regulation of early developmental gene expression. De novo protein-truncating mutations in ASXL1 cause Bohring-Opitz syndrome (BOS; OMIM #605039), a rare neurodevelopmental condition characterized by severe intellectual disabilities, distinctive facial features, hypertrichosis, increased risk of Wilms tumor, and variable congenital anomalies, including heart defects and severe skeletal defects giving rise to a typical BOS posture. These BOS-causing ASXL1 variants are also high-prevalence somatic driver mutations in acute myeloid leukemia. We used primary cells from individuals with BOS (n = 18) and controls (n = 49) to dissect gene regulatory changes caused by ASXL1 mutations using comprehensive multiomics assays for chromatin accessibility (ATAC-seq), DNA methylation, histone methylation binding, and transcriptome in peripheral blood and skin fibroblasts. Our data show that regardless of cell type, ASXL1 mutations drive strong cross-tissue effects that disrupt multiple layers of the epigenome. The data showed a broad activation of canonical Wnt signaling at the transcriptional and protein levels and upregulation of VANGL2, which encodes a planar cell polarity pathway protein that acts through noncanonical Wnt signaling to direct tissue patterning and cell migration. This multiomics approach identifies the core impact of ASXL1 mutations and therapeutic targets for BOS and myeloid leukemias.
Authors
Isabella Lin, Angela Wei, Zain Awamleh, Meghna Singh, Aileen Ning, Analeyla Herrera, REACH Biobank and Registry, Bianca E. Russell, Rosanna Weksberg, Valerie A. Arboleda
×Abstract
BACKGROUND Currently, no laboratory tests exist to stratify for the risk of developing sinusoidal obstruction syndrome (SOS), an early endothelial complication after hematopoietic cell transplantation (HCT). Risk biomarkers of SOS have not been verified in a prospective cohort accounting for differences between practices across institutions. Herein, we aimed to define risk groups for SOS occurrence using 3 proteins: L-ficolin, hyaluronic acid (HA), and stimulation 2 (ST2). METHODS Between 2017 and 2021, we prospectively accrued 80 pediatric patients across 4 US centers. Biomarkers were tested by ELISA blind to patient groupings and associated with SOS incidence on day 35 after HCT, and overall survival (OS) on day 100 after HCT. Cutpoints were identified using retrospective cohorts and applied to the prospective cohort.RESULTS Combination of the 3 biomarkers measured on day 3 after HCT in the prospective cohort provided 80% (95% CI 55%–100%) sensitivity and 73% (95% CI 62%–83%) specificity for risk of SOS occurrence. Patients with low L-ficolin were 9 times (95% CI 3–32) more likely to develop SOS, while patients with high HA and ST2 were 6.5 (95% CI 1.9–22.0) and 5.5 (95% CI 2.3–13.1) times more likely to develop SOS. These 3 markers also predicted worse day 100 OS — L-ficolin: HR, 10.0 (95% CI 2.2–45.1), P = 0.0002; HA: HR, 4.1 (95% CI 1.0–16.4), P = 0.031; and ST2: HR, 3.9 (95% CI 0.9–16.4), P = 0.04.CONCLUSION L-ficolin, HA, and ST2 levels measured as early as 3 days after HCT improved risk stratification for SOS occurrence and OS and may guide risk-adapted preemptive therapy.TRIAL REGISTRATION ClinicalTrials.gov NCT03132337.FUNDING NIH.
Authors
Yan Han, Alan Bidgoli, Brittany P. DePriest, Alejandra Méndez, Khadijeh Bijangi-Vishehsaraei, Evelio D. Perez-Albuerne, Robert A. Krance, Jamie Renbarger, Jodi L. Skiles, Sung W. Choi, Hao Liu, Sophie Paczesny
×Abstract
Background The SARS-CoV-2 Omicron BA.5 subvariant escapes vaccination-induced neutralizing antibodies because of mutations in the spike (S) protein. Solid organ transplant recipients (SOTRs) develop high COVID-19 morbidity and poor Omicron variant recognition after COVID-19 vaccination. T cell responses may provide a second line of defense. Therefore, understanding which vaccine regimens induce robust, conserved T cell responses is critical.Methods We evaluated anti-S IgG titers, subvariant pseudo-neutralization, and S-specific CD4+ and CD8+ T cell responses from SOTRs in a national, prospective, observational trial (n = 75). Participants were selected if they received 3 doses of mRNA (homologous boosting) or 2 doses of mRNA followed by Ad26.COV2.S (heterologous boosting).Results Homologous boosting with 3 mRNA doses induced the highest anti-S IgG titers. However, antibodies induced by both vaccine regimens demonstrated lower pseudo-neutralization against BA.5 compared with the ancestral strain. In contrast, vaccine-induced S-specific T cells maintained cross-reactivity against BA.5 compared with ancestral recognition. Homologous boosting induced higher frequencies of activated polyfunctional CD4+ T cell responses, with polyfunctional IL-21+ peripheral T follicular helper cells increased in mRNA-1273 compared with BNT162b2. IL-21+ cells correlated with antibody titers. Heterologous boosting with Ad26.COV2.S did not increase CD8+ responses compared to homologous boosting.Conclusion Boosting with the ancestral strain can induce cross-reactive T cell responses against emerging variants in SOTRs, but alternative vaccine strategies are required to induce robust CD8+ T cell responses.Funding Ben-Dov Family; NIH National Institute of Allergy and Infectious Diseases (NIAID) K24AI144954, NIAID K08AI156021, NIAID K23AI157893, NIAID U01AI138897, National Institute of Diabetes and Digestive and Kidney Diseases T32DK007713, and National Cancer Institute 1U54CA260492; Johns Hopkins Vice Dean of Research Support for COVID-19 Research in Immunopathogenesis; and Emory COVID-19 research repository.
Authors
Elizabeth A. Thompson, Wabathi Ngecu, Laila Stoddart, Trevor S. Johnston, Amy Chang, Katherine Cascino, Jennifer L. Alejo, Aura T. Abedon, Hady Samaha, Nadine Rouphael, Aaron A.R. Tobian, Dorry L. Segev, William A. Werbel, Andrew H. Karaba, Joel N. Blankson, Andrea L. Cox
×Abstract
In eutherians, the placenta plays a critical role in the uptake, storage, and metabolism of lipids. These processes govern the availability of fatty acids to the developing fetus, where inadequate supply has been associated with substandard fetal growth. Whereas lipid droplets are essential for the storage of neutral lipids in the placenta and many other tissues, the processes that regulate placental lipid droplet lipolysis remain largely unknown. To assess the role of triglyceride lipases and their cofactors in determining placental lipid droplet and lipid accumulation, we assessed the role of patatin like phospholipase domain containing 2 (PNPLA2) and comparative gene identification-58 (CGI58) in lipid droplet dynamics in the human and mouse placenta. While both proteins are expressed in the placenta, the absence of CGI58, not PNPLA2, markedly increased placental lipid and lipid droplet accumulation. These changes were reversed upon restoration of CGI58 levels selectively in the CGI58-deficient mouse placenta. Using co-immunoprecipitation, we found that, in addition to PNPLA2, PNPLA9 interacts with CGI58. PNPLA9 was dispensable for lipolysis in the mouse placenta yet contributed to lipolysis in human placental trophoblasts. Our findings establish a crucial role for CGI58 in placental lipid droplet dynamics and, by extension, in nutrient supply to the developing fetus.
Authors
Jennifer Guerrero-Santoro, Mayumi Morizane, Soo-Young Oh, Takuya Mishima, Julie P. Goff, Ibrahim Bildirici, Elena Sadovsky, Yingshi Ouyang, Vladimir A. Tyurin, Yulia Y. Tyurina, Valerian E. Kagan, Yoel Sadovsky
×Abstract
To improve our limited understanding of the pathogenesis of thoracic aortic aneurysm (TAA) that leads to acute aortic dissection, single-cell RNA sequencing (scRNA-seq) was employed to profile disease-relevant transcriptomic changes of aortic cell populations in a well-characterized mouse model of the most commonly diagnosed form of Marfan syndrome (MFS). As result, 2 discrete subpopulations of aortic cells (SMC3 and EC4) were identified only in the aorta of Fbn1mgR/mgR mice. SMC3 cells highly express genes related to extracellular matrix formation and nitric oxide signaling, whereas the EC4 transcriptional profile is enriched in smooth muscle cell (SMC), fibroblast, and immune cell–related genes. Trajectory analysis predicted close phenotypic modulation between SMC3 and EC4, which were therefore analyzed together as a discrete MFS-modulated (MFSmod) subpopulation. In situ hybridization of diagnostic transcripts located MFSmod cells at the intima of Fbn1mgR/mgR aortas. Reference-based data set integration revealed transcriptomic similarity between MFSmod- and SMC-derived cell clusters modulated in human TAA. Consistent with the angiotensin II type I receptor (At1r) contribution to TAA development, MFSmod cells were absent in the aorta of Fbn1mgR/mgR mice treated with the At1r antagonist losartan. Altogether, our findings indicate that a discrete dynamic alteration of aortic cell identity is associated with dissecting TAA in MFS mice and increased risk of aortic dissection in MFS patients.
Authors
Yifei Sun, Keiichi Asano, Lauriane Sedes, Anna Cantalupo, Jens Hansen, Ravi Iyengar, Martin J. Walsh, Francesco Ramirez
×Abstract
Leber congenital amaurosis (LCA) is a group of inherited retinal diseases characterized by early-onset, rapid loss of photoreceptor cells. Despite the discovery of a growing number of genes associated with this disease, the molecular mechanisms of photoreceptor cell degeneration of most LCA subtypes remain poorly understood. Here, using retina-specific affinity proteomics combined with ultrastructure expansion microscopy, we reveal the structural and molecular defects underlying LCA type 5 (LCA5) with nanoscale resolution. We show that LCA5-encoded lebercilin, together with retinitis pigmentosa 1 protein (RP1) and the intraflagellar transport (IFT) proteins IFT81 and IFT88, localized at the bulge region of the photoreceptor outer segment (OS), a region crucial for OS membrane disc formation. Next, we demonstrate that mutant mice deficient in lebercilin exhibited early axonemal defects at the bulge region and the distal OS, accompanied by reduced levels of RP1 and IFT proteins, affecting membrane disc formation and presumably leading to photoreceptor death. Finally, adeno-associated virus–based LCA5 gene augmentation partially restored the bulge region, preserved OS axoneme structure and membrane disc formation, and resulted in photoreceptor cell survival. Our approach thus provides a next level of assessment of retinal (gene) therapy efficacy at the molecular level.
Authors
Siebren Faber, Olivier Mercey, Katrin Junger, Alejandro Garanto, Helen May-Simera, Marius Ueffing, Rob W.J. Collin, Karsten Boldt, Paul Guichard, Virginie Hamel, Ronald Roepman
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Abstract
Fatty acid binding protein 4 (FABP4) is a lipid chaperone secreted from adipocytes upon stimulation of lipolysis. Circulating FABP4 levels strongly correlate with obesity and metabolic pathologies in experimental models and humans. While adipocytes have been presumed to be the major source of hormonal FABP4, this question has not been addressed definitively in vivo. We generated mice with Fabp4 deletion in cells known to express the gene; adipocytes (Adipo-KO), endothelial cells (Endo-KO), myeloid cells (Myeloid-KO), and the whole body (Total-KO) to examine the contribution of these cell types to basal and stimulated plasma FABP4 levels. Unexpectedly, baseline plasma FABP4 was not significantly reduced in Adipo-KO mice, whereas Endo-KO mice showed ~87% reduction versus wildtype controls. In contrast, Adipo-KO mice exhibited ~62% decreased induction of FABP4 responses to lipolysis, while Endo-KO mice showed only mildly decreased induction, indicating that adipocytes are the main source of increases in FABP4 during lipolysis. We did not detect any myeloid contribution to circulating FABP4. Surprisingly, despite the nearly intact induction of FABP4, Endo-KO mice showed blunted lipolysis-induced insulin secretion, identical to Total-KO mice. We conclude that the endothelium is the major source of baseline hormonal FABP4 and is required for the insulin response to lipolysis.
Authors
Karen E. Inouye, Kacey J. Prentice, Alexandra Lee, Zeqiu B. Wang, Carla Dominguez-Gonzalez, Mu Xian Chen, Jillian K. Riveros, M. Furkan Burak, Grace Y. Lee, Gokhan S. Hotamisligil
Abstract
During alveolar repair, alveolar type 2 (AT2) epithelial cell progenitors rapidly proliferate and differentiate into flat type 1 alveolar epithelial cells. Failure of normal alveolar repair mechanisms can lead to loss of alveolar structure (emphysema) or development of fibrosis, depending on the type and severity of injury. To test if β1-containing integrins are required during repair following acute injury, we administered E. coli lipopolysaccharide (LPS) by intratracheal injection to mice with a post-developmental deletion of β1 integrin in AT2 cells. While control mice recovered from LPS injury without structural abnormalities, β1-deficient mice had more severe inflammation and developed emphysema. In addition, recovering alveoli were repopulated with an abundance of rounded epithelial cells co-expressing type 2, type 1, and mixed intermediate cell state markers, with few mature type 1 cells. β1-deficient AT2 cells showed persistently increased proliferation after injury, which was blocked by inhibiting NF-kB activation in these cells. Lineage tracing experiments revealed that β1-deficient AT2 cells failed to differentiate into mature type 1 alveolar epithelial cells. Together, these findings demonstrate that functional alveolar repair after injury with terminal alveolar epithelial differentiation requires β1-containing integrins.
Authors
Jennifer M.S. Sucre, Fabian Bock, Nicholas M. Negretti, John T. Benjamin, Peter M. Gulleman, Xinyu Dong, Kimberly T. Ferguson, Christopher S. Jetter, Wei Han, Yang Liu, Seunghyi Kook, Jason J. Gokey, Susan H. Guttentag, Jonathan A. Kropski, Timothy S. Blackwell, Roy Zent, Erin J. Plosa
Abstract
Kawasaki disease (KD) is the leading cause of acquired heart disease among children. Increased platelet counts and activation are observed during the course of KD, and elevated platelet counts are associated with higher risks of developing intravenous immunoglobulin (IVIG) resistance and coronary artery (CA) aneurysms. However, the role of platelets in KD pathogenesis remains unclear. Here, we analyzed transcriptomics data generated from the whole blood of KD patients and discovered changes in the expression of platelet-related genes during acute KD. In the Lactobacillus casei cell wall extract (LCWE) murine model of KD vasculitis, LCWE injection increased platelet counts and the formation of monocyte-platelet aggregates (MPAs), upregulated the concentration of soluble P-selectin, and increased circulating thrombopoietin (TPO) and interleukin (IL)-6. Furthermore, platelet counts correlated with the severity of cardiovascular inflammation. Genetic depletion of platelets (mpl–/– mice) or treatment with anti-CD42b antibody led to a significant reduction of LCWE-induced cardiovascular lesions. Furthermore, in the mouse model, platelets promoted vascular inflammation via the formation of MPAs, which amplify IL-1β production. Altogether, our results indicate that platelet activation exacerbates the development of cardiovascular lesions in a murine model of KD vasculitis. These findings enhance our understanding of KD vasculitis pathogenesis and highlight MPAs, which are known to enhance IL-1β production, as a potential therapeutic target for this disorder.
Authors
Begüm Kocatürk, Youngho Lee, Nobuyuki Nosaka, Masanori Abe, Daisy Martinon, Malcolm E. Lane, Debbie Moreira, Shuang Chen, Michael C. Fishbein, Rebecca A. Porritt, Bernardo S. Franklin, Magali Noval Rivas, Moshe Arditi
Abstract
Stimulating the Gq-coupled P2Y2 receptor (P2ry2) lowers blood pressure. Global knockout of P2ry2 increases blood pressure. Vascular and renal mechanisms are believed to participate in P2ry2 effects on blood pressure. To isolate the role of the kidneys in P2ry2 effects on blood pressure and to reveal the molecular and cellular mechanisms of this action, we test here the necessity of the P2ry2 and the sufficiency of Gq-dependent signaling in renal principal cells to the regulation of the epithelial Na+ channel (ENaC), sodium excretion and blood pressure. Activating P2ry2 in littermate controls but not principal cell specific P2ry2 knockout mice decreases the activity of ENaC in renal tubules. Moreover, deletion of P2ry2 in principal cells abolishes increases in sodium excretion in response to stimulation of P2ry2 and compromises the normal ability to excrete a sodium load. Consequently, principal cell specific knockout of P2ry2 prevents decreases in blood pressure in response to P2ry2 stimulation in the DOCA-salt model of hypertension. In wild-type littermate controls, such stimulation decreases blood pressure in this model of hypertension by promoting a natriuresis. Pharmacogenetic activation of Gq exclusively in principal cells using targeted expression of Gq-DREADD (Designer Receptors Exclusively Activated by Designer Drugs; GqD) and clozapine N-oxide (CNO) decreases the activity of ENaC in renal tubules promoting a natriuresis that lowers elevated blood pressure in the DOCA-salt model of hypertension. These findings demonstrate that the kidneys play a major role in decreasing blood pressure in response to P2ry2 activation, and that inhibition of ENaC activity in response to P2ry2 mediated Gq signaling lowers blood pressure by increasing renal sodium excretion.
Authors
Antonio G. Soares, Jorge Contreras, Elena Mironova, Crystal R. Archer, James D. Stockand, Tarek M. Abd El-Aziz
Abstract
Osteosarcoma (OS) is the most common primary bone tumor of childhood. Approximately 20-30% of OS carry amplification of chromosome 8q24, which harbors the oncogene c-Myc and correlates with a poor prognosis. To understand the mechanisms that underlie the ability of Myc to alter both the tumor and its surrounding tumor microenvironment (TME), we generated and molecularly characterized an osteoblast-specific Cre-Lox-Stop-Lox;(LSL)-c-MycT58A;p53fl/+ knock-in genetically engineered mouse model (GEMM). Phenotypically, the Myc knockin-GEMM had rapid tumor development with a high incidence of metastasis. Myc-dependent gene signatures in our murine model demonstrated significant homology to the human hyperactivated Myc OS. We established that hyperactivation of Myc leads to an immune-depleted TME in OS demonstrated by the reduced number of leukocytes, particularly macrophages. Myc-hyperactivation leads to the downregulation of macrophage-colony-stimulating factor (CSF-1), through increased miR-17/20a expression, causing a reduction of macrophage population in the TME of OS. Furthermore, we developed cell lines from the GEMM tumors, including a dTAG-Myc model system, which validated our Myc-dependent findings both in vitro and in vivo. Our studies utilized innovative, and clinically relevant models to identify a novel molecular mechanism through which Myc regulates the profile and function of the osteosarcoma immune landscape.
Authors
Bikesh K. Nirala, Tajhal D. Patel, Lyazat Kurenbekova, Ryan Shuck, Atreyi Dasgupta, Nino Rainusso, Cristian Coarfa, Jason T. Yustein
