Publications by authors named "Divanovic S"

Susceptibility to inflammatory bowel diseases (IBDs), Crohn's disease (CD), and ulcerative colitis (UC) is linked with loss of intestinal epithelial barrier integrity and mitochondria dysfunction. Steroidogenic acute regulatory (StAR) protein-related lipid transfer (START) domain-containing protein 7 (STARD7) is a phosphatidylcholine-specific (PC-specific) lipid transfer protein that transports PC from the ER to the mitochondria, facilitating mitochondria membrane stabilization and respiration function. The aim of this study was to define the contribution of STARD7 in the regulation of the intestinal epithelial mitochondrial function and susceptibility to colitis.

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Obesity is a risk factor for increased lung damage and disease severity during influenza virus infection. White adipose tissue (WAT) inflammation is a key driver of disease pathogenesis in obesity. Whether and how obesity modifies lung and WAT immune cell character and function in obesity to amplify influenza disease severity remains unknown.

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Excessive fructose intake is a risk factor for the development of obesity and its complications. Targeting ketohexokinase (KHK), the first enzyme of fructose metabolism, has been investigated for the management of metabolic dysfunction-associated steatotic liver disease (MASLD). We compared the effects of systemic, small molecule inhibitor of KHK enzymatic activity with hepatocyte-specific, N-acetylgalactosamine siRNA-mediated knockdown of KHK in mice on an HFD.

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Background & Aims: Ulcerative colitis (UC) is associated with epithelial metabolic derangements which exacerbate gut inflammation. Patient-derived organoids recapitulate complexities of the parent tissue in health and disease; however, whether colon organoids (colonoids) model metabolic impairments in the pediatric UC epithelium is unclear. This study determined the functional metabolic differences in the colon epithelia using epithelial colonoids from pediatric patients.

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B cell-activating factor (BAFF) is a critical TNF-family cytokine that regulates homeostasis and peripheral tolerance of B2 cells. BAFF overproduction promotes autoantibody generation and autoimmune diseases. During obesity, BAFF is predominantly produced by white adipose tissue (WAT), and IgG autoantibodies against adipocytes are identified in the WAT of obese humans.

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Paneth cells (PCs), a subset of intestinal epithelial cells (IECs) found at the base of small intestinal crypts, play an essential role in maintaining intestinal homeostasis. Altered PCs function is associated with diverse intestinal pathologies, including ileal Crohn's disease (CD). CD patients with ileal involvement have been previously demonstrated to display impairment in PCs and decreased levels of anti-microbial peptides.

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Objective: Weight loss following vertical sleeve gastrectomy (VSG) in youth can range from 10% to 50%. We examined whether there are differences in demographic or metabolic parameters before VSG in youth who achieve above-average weight loss (AAWL) versus below-average weight loss (BAWL) at 1 year post VSG and if youth with BAWL still achieve metabolic health improvements at 1 year post VSG.

Methods: Demographic, anthropometric, and clinical lab data were collected before VSG and at 1, 3, 6, and 12 months after VSG.

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Pediatric metabolic dysfunction-associated steatotic liver disease (MASLD) is common and can be seen as early as . A growing body of literature suggests that gestational and early life exposures modify the risk of MASLD development in children. These include maternal risk factors, such as poor cardiometabolic health (e.

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  • Vertical transmission of obesity plays a significant role in the ongoing obesity epidemic and related metabolic diseases, yet current models fail to accurately reflect human obesity.
  • This study introduces a new mouse model that simulates "human-like" obesity by using a specific diet and housing conditions, revealing that maternal obesity negatively impacts neonatal survival, increases offspring fat accumulation, and heightens their risk for obesity-related diseases.
  • The findings suggest that severe maternal obesity alters the offspring's microbiome and creates a harmful inflammatory environment during pregnancy, which is supported by similar patterns observed in a human birth cohort study.
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  • Metabolic dysfunction-associated steatotic liver disease (MASLD) significantly increases the risk of severe liver diseases, yet effective treatments are lacking.
  • The disease involves complex immune responses where both innate and adaptive immune systems play a role, but their interactions and cooperative effects on MASLD are not fully understood.
  • This review discusses various immune cell types and their bidirectional communication processes that affect MASLD, suggesting that understanding these interactions could lead to new therapeutic strategies.
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Inflammation-driven preterm birth (PTB) is modeled in mice using lipopolysaccharide (LPS) challenge. Here, we present a protocol for cytokine and uterine immune cell characterization in a mouse model of LPS-induced PTB. We describe steps for LPS challenge, in vivo cytokine capture assay, and isolation of uterine immune cells for flow cytometry.

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  • Influenza virus-induced pneumonia poses significant public health risks, with obesity, metabolic diseases, and female sex identified as independent factors worsening the disease.
  • The lack of experimental models for studying severe obesity in female mice has limited research, but this study successfully induced severe obesity in female mice using a high-fat diet and thermoneutral housing.
  • The findings reveal that while traditionally lean mice show similar responses to influenza, introducing severe obesity and metabolic disease in female mice results in disease severity comparable to that of obese males, highlighting the critical role of these factors in influenza severity.
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Non-alcoholic fatty liver disease (NAFLD) is a liver manifestation of metabolic syndrome, and is estimated to affect one billion individuals worldwide. An increased intake of a high-fat diet (HFD) and sugar-sweetened beverages are risk-factors for NAFLD development, but how their combined intake promotes progression to a more severe form of liver injury is unknown. Here we show that fructose metabolism via ketohexokinase (KHK) C isoform leads to unresolved endoplasmic reticulum (ER) stress when coupled with a HFD intake.

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Clinical evidence points to a function for B cell-activating factor (BAFF) in pregnancy. However, direct roles for BAFF-axis members in pregnancy have not been examined. Here, via utility of genetically modified mice, we report that BAFF promotes inflammatory responsiveness and increases susceptibility to inflammation-induced preterm birth (PTB).

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Introduction: Inflammation is a common unifying factor in experimental models of non-alcoholic fatty liver disease (NAFLD) progression. Recent evidence suggests that housing temperature-driven alterations in hepatic inflammation correlate with exacerbated hepatic steatosis, development of hepatic fibrosis, and hepatocellular damage in a model of high fat diet-driven NAFLD. However, the congruency of these findings across other, frequently employed, experimental mouse models of NAFLD has not been studied.

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  • Non-alcoholic fatty liver disease (NAFLD) affects around one billion people globally and is linked to a high-fat diet and sugar intake, but the precise mechanism of how these factors interact to worsen liver injury is not well understood.
  • The study identifies that the ketohexokinase (KHK) C isoform plays a crucial role in increasing endoplasmic reticulum (ER) stress when fructose intake is combined with a high-fat diet, leading to more severe liver damage.
  • By reducing KHK levels in certain mouse models, researchers found improvements in liver health, suggesting that targeting KHK could be a potential strategy for managing NAFLD and its metabolic effects.
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  • The study explores how bone marrow can be generated from embryonic stem cells (ESCs) to enhance cell therapies for severe diseases, addressing existing technical limitations.
  • Using blastocyst complementation, researchers successfully produced various hematopoietic and stromal cell types from mouse ESCs in rat embryos, matching normal mouse bone marrow cell characteristics.
  • The findings highlighted efficient development of mouse hematopoietic stem cells (HSCs) in mouse-rat chimeras, demonstrating their potential for long-term reconstitution and successful transplantation in lethally irradiated mice.
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  • Aging and obesity both involve chronic, low-grade inflammation and dysfunctional immune responses, with emerging research revealing their interconnected mechanisms.
  • Chronic inflammation in these conditions alters the immune system's baseline state, where aging leads to regulatory immune populations that worsen dysfunction, while obesity affects immune cell function due to expanding fat tissue.
  • The review aims to compare these altered immune states in aging and obesity and explore how they contribute to a common issue: reduced effectiveness of vaccines.
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  • Butyrate, a short-chain fatty acid produced by microbes, plays a key role in reducing inflammation by promoting the differentiation of regulatory B cells that produce the anti-inflammatory cytokine IL-10.
  • This study found that butyrate specifically induces the formation of IL-10+IgM+ plasma cells from mouse B cells, while another fatty acid, propionate, has little effect on this process.
  • The findings suggest that butyrate's effects involve inhibition of histone deacetylase 3 (HDAC3), leading to changes in gene expression, and that reducing mitochondrial superoxide levels is crucial for the differentiation of plasma cells, although not specifically for IL-10 production.
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  • Type 2 diabetes (T2D) and obesity increase the risks of severe illness from influenza and SARS-CoV-2 infections due to their impact on immune cell function and inflammatory responses.
  • Altered immune responses and high levels of inflammatory substances in the body are associated with increased severity of COVID-19, but the specific role of fat cells, particularly in obesity, in this process is still unclear.
  • The research aims to investigate how changes in fat cell metabolism could lead to more severe disease in people with obesity and T2D during infections, highlighting important areas where more understanding is needed.
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Isolation of viable immune cells from human tissues is critical for the characterization of cellular and molecular processes underlying disease pathogenesis. Here, we describe protocols for the isolation of highly viable immune cells from liver wedges and mesenteric white adipose tissue resections from obese persons. Notably, characterization of the isolated single-immune cell suspensions, via utility of basic immunological interrogations and genetic approaches, promises to generate an improved understanding of altered immunological pathways in obese individuals with or without metabolic diseases.

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  • Intrauterine infection/inflammation (IUI) can lead to preterm labor (PTL), but not all cases of IUI result in PTL, indicating differences in immune responses.
  • Researchers developed rhesus macaque models to study the effects of two types of IUI triggers: lipopolysaccharide (LPS) and live E. coli, finding that only E. coli infections frequently resulted in PTL.
  • The study found that while both triggers caused immune cell infiltration, E. coli led to a stronger inflammatory response with higher levels of inflammatory mediators like interleukin 6 (IL-6), suggesting that the severity of the immune response to IUI influences the likelihood of PTL.
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Unlabelled: Nonalcoholic fatty liver disease is clinically silent and the age of its onset is unknown. Fatty liver can occur as early as in utero in the context of an unfavorable maternal metabolic environment. Our objective was to determine the prevalence of hepatic steatosis in a cohort of previously healthy infants less than 3 months of age.

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Objective: The risks of excess sugar intake in addition to high-fat diet consumption on immunopathogenesis of obesity-associated metabolic diseases are poorly defined. Interleukin-4 (IL-4) and IL-13 signaling via IL-4Rα regulates adipose tissue lipolysis, insulin sensitivity, and liver fibrosis in obesity. However, the contribution of IL-4Rα to sugar rich diet-driven obesity and metabolic sequelae remains unknown.

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Background & Aims: CD4 T cells are regulated by activating and inhibitory cues, and dysregulation of these proper regulatory inputs predisposes these cells to aberrant inflammation and exacerbation of disease. We investigated the role of the inhibitory receptor paired immunoglobulin-like receptor B (PIR-B) in the regulation of the CD4 T-cell inflammatory response and exacerbation of the colitic phenotype.

Methods: We used Il10 spontaneous and CD4CD45RB T-cell transfer models of colitis with PIR-B-deficient (Pirb) mice.

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