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82 result(s) for "Sims, Matthew C."
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Transcriptional, epigenetic and metabolic signatures in cardiometabolic syndrome defined by extreme phenotypes
Background This work is aimed at improving the understanding of cardiometabolic syndrome pathophysiology and its relationship with thrombosis by generating a multi-omic disease signature. Methods/results We combined classic plasma biochemistry and plasma biomarkers with the transcriptional and epigenetic characterisation of cell types involved in thrombosis, obtained from two extreme phenotype groups (morbidly obese and lipodystrophy) and lean individuals to identify the molecular mechanisms at play, highlighting patterns of abnormal activation in innate immune phagocytic cells. Our analyses showed that extreme phenotype groups could be distinguished from lean individuals, and from each other, across all data layers. The characterisation of the same obese group, 6 months after bariatric surgery, revealed the loss of the abnormal activation of innate immune cells previously observed. However, rather than reverting to the gene expression landscape of lean individuals, this occurred via the establishment of novel gene expression landscapes. NETosis and its control mechanisms emerge amongst the pathways that show an improvement after surgical intervention. Conclusions We showed that the morbidly obese and lipodystrophy groups, despite some differences, shared a common cardiometabolic syndrome signature. We also showed that this could be used to discriminate, amongst the normal population, those individuals with a higher likelihood of presenting with the disease, even when not displaying the classic features.
Transcriptional, epigenetic and metabolic signatures in cardiometabolic syndrome defined by extreme phenotypes
Abstract Improving the understanding of cardiometabolic syndrome pathophysiology and its relationship with thrombosis are ongoing healthcare challenges. Using plasma biomarkers analysis coupled with the transcriptional and epigenetic characterisation of cell types involved in thrombosis, obtained from two extreme phenotype groups (obese and lipodystrophy) and comparing these to lean individuals and blood donors, the present study identifies the molecular mechanisms at play, highlighting patterns of abnormal activation in innate immune phagocytic cells and shows that extreme phenotype groups could be distinguished from lean individuals, and from each other, across all data layers. The characterisation of the same obese group, six months after bariatric surgery shows the loss of the patterns of abnormal activation of innate immune cells previously observed. However, rather than reverting to the gene expression landscape of lean individuals, this occurs via the establishment of novel gene expression landscapes. Netosis and its control mechanisms emerge amongst the pathways that show an improvement after surgical intervention. Taken together, by integrating across data layers, the observed molecular and metabolic differences form a disease signature that is able to discriminate, amongst the blood donors, those individuals with a higher likelihood of having cardiometabolic syndrome, even when not presenting with the classic features. Competing Interest Statement The authors have declared no competing interest. Footnotes * Further information and requests for resources should be directed to and will be fulfilled by the Lead Contact, Mattia Frontini(m.frontini{at}exeter.ac.uk). * Text was updated for clarity, added new main figure 5.
SER-109, an Oral Microbiome Therapy for Recurrent Clostridioides difficile Infection
A major challenge with the treatment of Clostridioides difficile infection is restoring the antibiotic-associated alterations of bowel flora to a state less hospitable to C. difficile . In this trial, a microbiome-replacement therapy, SER-109, was used to treat patients with recurrent C. difficile infection and was shown to reduce the risk of further recurrence.
Oncostatin M promotes bone formation independently of resorption when signaling through leukemia inhibitory factor receptor in mice
Effective osteoporosis therapy requires agents that increase the amount and/or quality of bone. Any modification of osteoclast-mediated bone resorption by disease or drug treatment, however, elicits a parallel change in osteoblast-mediated bone formation because the processes are tightly coupled. Anabolic approaches now focus on uncoupling osteoblast action from osteoclast formation, for example, by inhibiting sclerostin, an inhibitor of bone formation that does not influence osteoclast differentiation. Here, we report that oncostatin M (OSM) is produced by osteoblasts and osteocytes in mouse bone and that it has distinct effects when acting through 2 different receptors, OSM receptor (OSMR) and leukemia inhibitory factor receptor (LIFR). Specifically, mouse OSM (mOSM) inhibited sclerostin production in a stromal cell line and in primary murine osteoblast cultures by acting through LIFR. In contrast, when acting through OSMR, mOSM stimulated RANKL production and osteoclast formation. A key role for OSMR in bone turnover was confirmed by the osteopetrotic phenotype of mice lacking OSMR. Furthermore, in contrast to the accepted model, in which mOSM acts only through OSMR, mOSM inhibited sclerostin expression in Osmr-/- osteoblasts and enhanced bone formation in vivo. These data reveal what we believe to be a novel pathway by which bone formation can be stimulated independently of bone resorption and provide new insights into OSMR and LIFR signaling that are relevant to other medical conditions, including cardiovascular and neurodegenerative diseases and cancer.
Histone deacetylase 3 prepares brown adipose tissue for acute thermogenic challenge
Histone deacetylase 3 (HDAC3) is required to activate brown adipose tissue enhancers to ensure thermogenic aptitude. How brown fat keeps us from the cold Brown adipose tissue (BAT), or brown fat, protects against hypothermia by generating heat. Mitchell Lazar and colleagues discovered a critical and novel role of the epigenetic modulator HDAC3 in controlling the ability of BAT to respond to acute thermogenic challenges. They report that histone deacetylase 3 (HDAC3) acts in BAT as a transcriptional coactivator to ensure basal transcription of BAT-specific genes, independent of adrenergic stimulation. HDAC3 primes UCP1 and the thermogenic transcriptional program to maintain a critical capacity for thermogenesis in BAT that can be rapidly engaged for thermogenic respiration and heat production on demand. This improves our understanding of the physiological basis for mammalian response to extreme cold exposure. Brown adipose tissue is a thermogenic organ that dissipates chemical energy as heat to protect animals against hypothermia and to counteract metabolic disease 1 . However, the transcriptional mechanisms that determine the thermogenic capacity of brown adipose tissue before environmental cold are unknown. Here we show that histone deacetylase 3 (HDAC3) is required to activate brown adipose tissue enhancers to ensure thermogenic aptitude. Mice with brown adipose tissue-specific genetic ablation of HDAC3 become severely hypothermic and succumb to acute cold exposure. Uncoupling protein 1 (UCP1) is nearly absent in brown adipose tissue lacking HDAC3, and there is also marked downregulation of mitochondrial oxidative phosphorylation genes resulting in diminished mitochondrial respiration. Remarkably, although HDAC3 acts canonically as a transcriptional corepressor 2 , it functions as a coactivator of oestrogen-related receptor α (ERRα) in brown adipose tissue. HDAC3 coactivation of ERRα is mediated by deacetylation of PGC-1α and is required for the transcription of Ucp1 , Ppargc1a (encoding PGC-1α), and oxidative phosphorylation genes. Importantly, HDAC3 promotes the basal transcription of these genes independently of adrenergic stimulation. Thus, HDAC3 uniquely primes Ucp1 and the thermogenic transcriptional program to maintain a critical capacity for thermogenesis in brown adipose tissue that can be rapidly engaged upon exposure to dangerously cold temperature.
Oxidation of the alarmin IL-33 regulates ST2-dependent inflammation
In response to infections and irritants, the respiratory epithelium releases the alarmin interleukin (IL)-33 to elicit a rapid immune response. However, little is known about the regulation of IL-33 following its release. Here we report that the biological activity of IL-33 at its receptor ST2 is rapidly terminated in the extracellular environment by the formation of two disulphide bridges, resulting in an extensive conformational change that disrupts the ST2 binding site. Both reduced (active) and disulphide bonded (inactive) forms of IL-33 can be detected in lung lavage samples from mice challenged with Alternaria extract and in sputum from patients with moderate–severe asthma. We propose that this mechanism for the rapid inactivation of secreted IL-33 constitutes a ‘molecular clock’ that limits the range and duration of ST2-dependent immunological responses to airway stimuli. Other IL-1 family members are also susceptible to cysteine oxidation changes that could regulate their activity and systemic exposure through a similar mechanism. IL-33, released by epithelial cells in response to stress, is a potent activator of inflammation. Here Cohen et al . show that secreted IL-33 is rapidly inactivated by disulfide bond formation that prevents binding to its receptor, and that IL-33-related cytokines are susceptible to similar oxidation.
Exome sequencing in amyotrophic lateral sclerosis identifies risk genes and pathways
Amyotrophic lateral sclerosis (ALS) is a devastating neurological disease with no effective treatment. We report the results of a moderate-scale sequencing study aimed at increasing the number of genes known to contribute to predisposition for ALS. We performed whole-exome sequencing of 2869 ALS patients and 6405 controls. Several known ALS genes were found to be associated, and TBK1 (the gene encoding TANK-binding kinase 1) was identified as an ALS gene. TBK1 is known to bind to and phosphorylate a number of proteins involved in innate immunity and autophagy, including optineurin (OPTN) and p62 (SQSTM1/sequestosome), both of which have also been implicated in ALS. These observations reveal a key role of the autophagic pathway in ALS and suggest specific targets for therapeutic intervention.
Predicting incident cardiovascular disease among African-American adults: A deep learning approach to evaluate social determinants of health in the Jackson heart study
The present study sought to leverage machine learning approaches to determine whether social determinants of health improve prediction of incident cardiovascular disease (CVD). Participants in the Jackson Heart study with no history of CVD at baseline were followed over a 10-year period to determine first CVD events (i.e., coronary heart disease, stroke, heart failure). Three modeling algorithms (i.e., Deep Neural Network, Random Survival Forest, Penalized Cox Proportional Hazards) were used to evaluate three feature sets (i.e., demographics and standard/biobehavioral CVD risk factors [FS1], FS1 combined with psychosocial and socioeconomic CVD risk factors [FS2], and FS2 combined with environmental features [FS3]) as predictors of 10-year CVD risk. Contrary to hypothesis, overall predictive accuracy did not improve when adding social determinants of health. However, social determinants of health comprised eight of the top 15 predictors of first CVD events. The social determinates of health indicators included four socioeconomic factors (insurance status and types), one psychosocial factor (discrimination burden), and three environmental factors (density of outdoor physical activity resources, including instructional and water activities; modified retail food environment index excluding alcohol; and favorable food stores). Findings suggest that whereas understanding biological determinants may identify who is currently at risk for developing CVD and in need of secondary prevention, understanding upstream social determinants of CVD risk could guide primary prevention efforts by identifying where and how policy and community-level interventions could be targeted to facilitate changes in individual health behaviors.
Chromosomal rearrangements maintain a polymorphic supergene controlling butterfly mimicry
Evolution of supergenes The toxic butterfly Heliconius numata , found in forests across South America, mimics the wing patterns of several species of another family of toxic butterflies, Melinaea sp., in order to deter predators more effectively. This example of Müllerian mimicry is under the control of a classic 'supergene', a tight gene cluster usually inherited as a single unit. H. numata is particularly adept at mimicry, able to copy as many as seven different wing patterns. A study of the individual wing-pattern morphs in H. numata shows that different genomic rearrangements at the single supergene P locus tighten the genetic linkage between loci that are otherwise free to recombine in other closely related species. The resulting supergene acts as a simple switch that once thrown, selects which one of a range of complex adaptive phenotypes the butterfly displays. Supergenes are tight clusters of loci that facilitate the co-segregation of adaptive variation, providing integrated control of complex adaptive phenotypes 1 . Polymorphic supergenes, in which specific combinations of traits are maintained within a single population, were first described for ‘pin’ and ‘thrum’ floral types in Primula 1 and Fagopyrum 2 , but classic examples are also found in insect mimicry 3 , 4 , 5 and snail morphology 6 . Understanding the evolutionary mechanisms that generate these co-adapted gene sets, as well as the mode of limiting the production of unfit recombinant forms, remains a substantial challenge 7 , 8 , 9 , 10 . Here we show that individual wing-pattern morphs in the polymorphic mimetic butterfly Heliconius numata are associated with different genomic rearrangements at the supergene locus P . These rearrangements tighten the genetic linkage between at least two colour-pattern loci that are known to recombine in closely related species 9 , 10 , 11 , with complete suppression of recombination being observed in experimental crosses across a 400-kilobase interval containing at least 18 genes. In natural populations, notable patterns of linkage disequilibrium (LD) are observed across the entire P region. The resulting divergent haplotype clades and inversion breakpoints are found in complete association with wing-pattern morphs. Our results indicate that allelic combinations at known wing-patterning loci have become locked together in a polymorphic rearrangement at the P locus, forming a supergene that acts as a simple switch between complex adaptive phenotypes found in sympatry. These findings highlight how genomic rearrangements can have a central role in the coexistence of adaptive phenotypes involving several genes acting in concert, by locally limiting recombination and gene flow.
MERS-CoV and H5N1 influenza virus antagonize antigen presentation by altering the epigenetic landscape
Convergent evolution dictates that diverse groups of viruses will target both similar and distinct host pathways to manipulate the immune response and improve infection. In this study, we sought to leverage this uneven viral antagonism to identify critical host factors that govern disease outcome. Utilizing a systems-based approach, we examined differential regulation of IFN-γ–dependent genes following infection with robust respiratory viruses including influenza viruses [A/influenza/Vietnam/1203/2004 (H5N1-VN1203) and A/influenza/California/04/2009 (H1N1-CA04)] and coronaviruses [severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome CoV (MERS-CoV)]. Categorizing by function, we observed down-regulation of gene expression associated with antigen presentation following both H5N1-VN1203 and MERS-CoV infection. Further examination revealed global down-regulation of antigen-presentation gene expression, which was confirmed by proteomics for both H5N1-VN1203 and MERS-CoV infection. Importantly, epigenetic analysis suggested that DNA methylation, rather than histone modification, plays a crucial role in MERS-CoV–mediated antagonism of antigen presentation gene expression; in contrast, H5N1-VN1203 likely utilizes a combination of epigenetic mechanisms to target antigen presentation. Together, the results indicate a common mechanism utilized by H5N1-VN1203 and MERS-CoV to modulate antigen presentation and the host adaptive immune response.