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International Journal of Molecular... Nov 2023In patients with portal hypertension, there are many complications including cardiovascular abnormalities, hepatorenal syndrome, ascites, variceal bleeding, and hepatic... (Review)
Review
In patients with portal hypertension, there are many complications including cardiovascular abnormalities, hepatorenal syndrome, ascites, variceal bleeding, and hepatic encephalopathy. The underlying mechanisms are not yet completely clarified. It is well known that portal hypertension causes mesenteric congestion which produces reactive oxygen species (ROS). ROS has been associated with intestinal mucosal injury, increased intestinal permeability, enhanced gut bacterial overgrowth, and translocation; all these changes result in increased endotoxin and inflammation. Portal hypertension also results in the development of collateral circulation and reduces liver mass resulting in an overall increase in endotoxin/bacteria bypassing detoxication and immune clearance in the liver. Endotoxemia can in turn aggravate oxidative stress and inflammation, leading to a cycle of gut barrier dysfunction → endotoxemia → organ injury. The phenotype of cardiovascular abnormalities includes hyperdynamic circulation and cirrhotic cardiomyopathy. Oxidative stress is often accompanied by inflammation; thus, blocking oxidative stress can minimize the systemic inflammatory response and alleviate the severity of cardiovascular diseases. The present review aims to elucidate the role of oxidative stress in cirrhosis-associated cardiovascular abnormalities and discusses possible therapeutic effects of antioxidants on cardiovascular complications of cirrhosis including hyperdynamic circulation, cirrhotic cardiomyopathy, and hepatorenal syndrome.
Topics: Humans; Esophageal and Gastric Varices; Hepatorenal Syndrome; Reactive Oxygen Species; Endotoxemia; Gastrointestinal Hemorrhage; Liver Cirrhosis; Hypertension, Portal; Oxidative Stress; Inflammation; Cardiomyopathies; Cardiovascular Abnormalities; Endotoxins
PubMed: 38069125
DOI: 10.3390/ijms242316805 -
Frontiers in Immunology 2023The recent discovery of TAK981(Subasumstat), the first-in-class selective inhibitor of SUMOylation, enables new immune treatments. TAK981 is already in clinical trials...
INTRODUCTION
The recent discovery of TAK981(Subasumstat), the first-in-class selective inhibitor of SUMOylation, enables new immune treatments. TAK981 is already in clinical trials to potentiate immunotherapy in metastatic tumors and hematologic malignancies. Cancer patients have more than ten times higher risk of infections, but the effects of TAK981 in sepsis are unknown and previous studies on SUMO in infections are conflicting.
METHODS
We used TAK981 in two sepsis models; polymicrobial peritonitis (CLP) and LPS endotoxemia. Splenectomy was done in both models to study the role of spleen. Western blotting of SUMO-conjugated proteins in spleen lysates was done. Global SUMO1 and SUMO3 knockout mice were used to study the specific SUMO regulation of inflammation in LPS endotoxemia. Splenocytes adoptive transfer was done from SUMO knockouts to wild type mice to study the role of spleen SUMOylation in experimental sepsis.
RESULTS AND DISCUSSION
Here, we report that inhibition of SUMOylation with TAK981 improved survival in mild polymicrobial peritonitis by enhancing innate immune responses and peritoneal bacterial clearance. Thus, we focused on the effects of TAK981 on the immune responses to bacterial endotoxin, showing that TAK981 enhanced early TNFα production but did not affect the resolution of inflammation. Splenectomy decreased serum TNFα levels by nearly 60% and TAK981-induced TNFα responses. In the spleen, endotoxemia induced a distinct temporal and substrate specificity for SUMO1 and SUMO2/3, and both were inhibited by TAK981. Global genetic depletion of SUMO1, but not SUMO3, enhanced TNFα production and metabolic acidosis. The transfer of SUMO1-null, but not wild-type, splenocytes into splenectomized wild-type mice exacerbated TNFα production and metabolic acidosis in endotoxemia.
CONCLUSION
These results suggest that specific regulation of splenic SUMO1 can modulate immune and metabolic responses to bacterial infection.
Topics: Animals; Mice; Endotoxemia; Lipopolysaccharides; Mice, Knockout; Peritonitis; Small Ubiquitin-Related Modifier Proteins; Spleen; Tumor Necrosis Factor-alpha; SUMO-1 Protein
PubMed: 37520526
DOI: 10.3389/fimmu.2023.1200939 -
Critical Care (London, England) Sep 2023The triggering factors of sepsis-induced myocardial dysfunction (SIMD) are poorly understood and are not addressed by current treatments. S100A8/A9 is a pro-inflammatory...
BACKGROUND AND AIMS
The triggering factors of sepsis-induced myocardial dysfunction (SIMD) are poorly understood and are not addressed by current treatments. S100A8/A9 is a pro-inflammatory alarmin abundantly secreted by activated neutrophils during infection and inflammation. We investigated the efficacy of S100A8/A9 blockade as a potential new treatment in SIMD.
METHODS
The relationship between plasma S100A8/A9 and cardiac dysfunction was assessed in a cohort of 62 patients with severe sepsis admitted to the intensive care unit of Linköping University Hospital, Sweden. We used S100A8/A9 blockade with the small-molecule inhibitor ABR-238901 and S100A9 mice for therapeutic and mechanistic studies on endotoxemia-induced cardiac dysfunction in mice.
RESULTS
In sepsis patients, elevated plasma S100A8/A9 was associated with left-ventricular (LV) systolic dysfunction and increased SOFA score. In wild-type mice, 5 mg/kg of bacterial lipopolysaccharide (LPS) induced rapid plasma S100A8/A9 increase and acute LV dysfunction. Two ABR-238901 doses (30 mg/kg) administered intraperitoneally with a 6 h interval, starting directly after LPS or at a later time-point when LV dysfunction is fully established, efficiently prevented and reversed the phenotype, respectively. In contrast, dexamethasone did not improve cardiac function compared to PBS-treated endotoxemic controls. S100A8/A9 inhibition potently reduced systemic levels of inflammatory mediators, prevented upregulation of inflammatory genes and restored mitochondrial function in the myocardium. The S100A9 mice were protected against LPS-induced LV dysfunction to an extent comparable with pharmacologic S100A8/A9 blockade. The ABR-238901 treatment did not induce an additional improvement of LV function in the S100A9 mice, confirming target specificity.
CONCLUSION
Elevated S100A8/A9 is associated with the development of LV dysfunction in severe sepsis patients and in a mouse model of endotoxemia. Pharmacological blockade of S100A8/A9 with ABR-238901 has potent anti-inflammatory effects, mitigates myocardial dysfunction and might represent a novel therapeutic strategy for patients with severe sepsis.
Topics: Animals; Humans; Mice; Calgranulin A; Calgranulin B; Endotoxemia; Heart Diseases; Inflammation; Lipopolysaccharides; Myocardium; Ventricular Dysfunction, Left
PubMed: 37773186
DOI: 10.1186/s13054-023-04652-x -
Thrombosis Research Dec 2023Patients with inflammatory bowel disease (IBD) have an increased risk of developing venous thromboembolic events, which have a considerable impact on morbidity and... (Review)
Review
Patients with inflammatory bowel disease (IBD) have an increased risk of developing venous thromboembolic events, which have a considerable impact on morbidity and mortality. Chronic inflammation plays a crucial role in the pathogenesis of thrombotic events in patients with IBD. However, many unresolved questions remain, particularly regarding the mechanisms that determine the persistent inflammatory state independent of disease activity. This review explored the role of gut microbiota dysbiosis and intestinal barrier dysfunction, which are considered distinctive features of IBD, in determining pro-thrombotic tendencies. Gut-derived endotoxemia due to the translocation of bacterial lipopolysaccharides (LPS) from the intestine to the bloodstream and the bacterial metabolite trimethylamine-N-oxide (TMAO) are the most important molecules involved in gut dysbiosis-related thrombosis. The pathogenic prothrombotic pathways linked to LPS and TMAO have been discussed. Finally, we present emerging therapeutic approaches that can help reduce LPS-mediated endotoxemia and TMAO, such as restoring intestinal eubiosis, normalizing intestinal barrier function, and counterbalancing the effects of LPS and TMAO.
Topics: Humans; Dysbiosis; Endotoxemia; Lipopolysaccharides; Inflammatory Bowel Diseases; Thrombosis; Gastrointestinal Diseases
PubMed: 37951044
DOI: 10.1016/j.thromres.2023.11.005 -
Internal and Emergency Medicine Aug 2023Recently, compelling evidence points to dysbiosis and disruption of the epithelial intestinal barrier as major players in the pathophysiology of metabolic disorders,... (Review)
Review
Recently, compelling evidence points to dysbiosis and disruption of the epithelial intestinal barrier as major players in the pathophysiology of metabolic disorders, such as obesity. Upon the intestinal barrier disruption, components from bacterial metabolism and bacteria itself can reach peripheral tissues through circulation. This has been associated with the low-grade inflammation that characterizes obesity and other metabolic diseases. While circulating bacterial DNA has been postulated as a common feature of obesity and even type 2 diabetes, almost no focus has been given to the existence and effects of bacteria in peripheral tissues, namely the adipose tissue. As a symbiont population, it is expected that gut microbiota modulate the immunometabolism of the host, thus influencing energy balance mechanisms and inflammation. Gut inflammatory signals cause direct deleterious inflammatory responses in adipose tissue and may also affect key gut neuroendocrine mechanisms governing nutrient sensing and energy balance, like incretins and ghrelin, which play a role in the gut-brain-adipose tissue axis. Thus, it is of major importance to disclose how gut microbiota and derived signals modulate neuroendocrine and inflammatory pathways, which contribute to the dysfunction of adipose tissue and to the metabolic sequelae of obesity and related disorders. This review summarizes the current knowledge regarding these topics and identifies new perspectives in this field of research, highlighting new pathways toward the reduction of the inflammatory burden of metabolic diseases.
Topics: Humans; Endotoxemia; Diabetes Mellitus, Type 2; Dysbiosis; Inflammation; Metabolic Diseases; Obesity; Adipose Tissue
PubMed: 37014495
DOI: 10.1007/s11739-023-03262-3 -
Brazilian Journal of Anesthesiology... 2023Sepsis and septic shock still represent great challenges in critical care medicine. Sildenafil has been largely used in the treatment of pulmonary arterial hypertension,...
BACKGROUND
Sepsis and septic shock still represent great challenges in critical care medicine. Sildenafil has been largely used in the treatment of pulmonary arterial hypertension, but its effects in sepsis are unknown. The aim of this study was to investigate the hypothesis that sildenafil can attenuate endotoxin-induced pulmonary hypertension in a porcine model of endotoxemia.
METHODS
Twenty pigs were randomly assigned to Control group (n.ß=.ß10), which received saline solution; or to Sildenafil group (n.ß=.ß10), which received sildenafil orally (100.ßmg). After 30.ßminutes, both groups were submitted to endotoxemia with intravenous bacterial lipopolysaccharide endotoxin (LPS) infusion (4.ß..g.kg.h) for 180.ßminutes. We evaluated hemodynamic and oxygenation functions, and also lung histology and plasma cytokine (TNF.., IL-1.., IL6, and IL10) and troponin I response.
RESULTS
Significant hemodynamic alterations were observed after 30.ßminutes of LPS continuous infusion, mainly in pulmonary arterial pressure (from Baseline 19.ß...ß2.ßmmHg to LPS30 52.ß...ß4.ßmmHg, p.ß<.ß0.05). There was also a significant decrease in PaO/FiO (from Baseline 411.ß...ß29 to LPS180 334.ß...ß49, p.ß<.ß0.05). Pulmonary arterial pressure was significantly lower in the Sildenafil group (35.ß...ß4.ßmmHg at LPS30, p.ß<.ß0.05). The Sildenafil group also presented lower values of systemic arterial pressure. Sildenafil maintained oxygenation with higher PaO/FiO and lower oxygen extraction rate than Control group but had no effect on intrapulmonary shunt. All cytokines and troponin increased after LPS infusion in both groups similarly.
CONCLUSION
Sildenafil attenuated endotoxin-induced pulmonary hypertension preserving the correct heart function without improving lung lesions or inflammation.
Topics: Animals; Swine; Sildenafil Citrate; Hypertension, Pulmonary; Endotoxins; Endotoxemia; Lipopolysaccharides; Hemodynamics
PubMed: 34118261
DOI: 10.1016/j.bjane.2021.05.016 -
International Journal of Molecular... Nov 2023Sepsis results from uncontrolled inflammation, characterized by cytokine storm and immunoparalysis. To assess whether galgravin, a natural lignan isolated from , can be...
Sepsis results from uncontrolled inflammation, characterized by cytokine storm and immunoparalysis. To assess whether galgravin, a natural lignan isolated from , can be used to treat sepsis, models of bacterial lipopolysaccharide (LPS)-activated macrophages and LPS-induced endotoxemia mice were used. Galgravin suppressed NF-κB activation in LPS-activated RAW 264.7 macrophages without causing significant cytotoxicity, in which proinflammatory molecules like TNF-α, IL-6, iNOS, and COX-2 were downregulated. In addition, the expression of TNF-α and IL-6 was also suppressed by galgravin in LPS-activated murine bone marrow-derived macrophages. Moreover, galgravin significantly downregulated the mRNA expression of TNF-α, IL-6, and iNOS in the lungs and decreased TNF-α and IL-6 in the serum and IL-6 in the bronchoalveolar lavage fluid of LPS-challenged mice. The COX-2 expression in tissues, including the lung, liver, and kidney, as well as the lung alveolar hemorrhage, was also reduced by galgravin. The present study reveals the anti-inflammatory effects of galgravin in mouse models and implies its potential application in inflammation diseases.
Topics: Mice; Animals; Lipopolysaccharides; NF-kappa B; Kadsura; Tumor Necrosis Factor-alpha; Endotoxemia; Anti-Inflammatory Agents; Interleukin-6; Cyclooxygenase 2; Piper; Inflammation; Lignans
PubMed: 38068895
DOI: 10.3390/ijms242316572 -
Research in Veterinary Science Sep 2023Sepsis of Gram negative bacterial origin results in lipopolysaccharide-induced endotoxemia. This often leads to acute kidney injury (AKI) and its recognition remains a...
Sepsis of Gram negative bacterial origin results in lipopolysaccharide-induced endotoxemia. This often leads to acute kidney injury (AKI) and its recognition remains a challenge and delays treatment. As renal damage occurs before a rise in serum creatinine is detected, new early biomarkers of kidney injury need to be explored. The aim of this study was to determine changes in serum parameters of renal function and urine biomarkers of renal injury. This was a descriptive study. Endotoxemia was induced intravenously in six anaesthetized Beagles (T1). To achieve normotension, dogs received fluids (T2), followed by a continuous infusion of noradrenaline and dexmedetomidine or 0.9% NaCl (T3). Ten minutes later, the dogs received fluids (T4) and noradrenaline and dexmedetomidine or 0.9% NaCl in a crossover manner (T5). At each timepoint, blood and urine were collected for serum creatinine, urea, symmetric dimethylarginine, urine protein/creatinine (UPC) ratio, urine neutrophil-gelatinase-associated lipocalin (U-NGAL), U-NGAL/creatinine ratio, urine clusterin (U-clusterin) and U-clusterin/creatinine ratio. Data were analyzed using a mixed-effect model taking into account time and stage of veterinary AKI (VAKI). Three of six dogs had a VAKI stage ≥1; one with anuria and elevated creatinine. Serum creatinine (P < 0.001), U-NGAL/creatinine ratio (P = 0.01) and U-clusterin/creatinine ratio increased over time (P < 0.01). The UPC ratio (mean (range) 0.68 (0.35-2.3) versus 0.39 (0.15-0.71) P < 0.01) and U-NGAL (3164 pg/mL (100-147,555) versus 100 (100-14,524), P = 0.01) were higher in VAKI stage ≥1 versus stage 0, respectively. Endotoxemia induced VAKI stage ≥1 in half of the dogs. Repeated measurement of selected parameters could detect AKI early.
Topics: Animals; Dogs; Lipocalin-2; Creatinine; Dexmedetomidine; Endotoxins; Clusterin; Endotoxemia; Saline Solution; Lipocalins; Proto-Oncogene Proteins; Acute-Phase Proteins; Kidney; Acute Kidney Injury; Biomarkers; Dog Diseases
PubMed: 37516042
DOI: 10.1016/j.rvsc.2023.104966 -
Food Research International (Ottawa,... Jun 2024Women with the extremely prevalent polycystic ovary syndromegather multiple cardiovascular risk factors and chronic subclinical inflammation. Interactions between diet,...
Women with the extremely prevalent polycystic ovary syndromegather multiple cardiovascular risk factors and chronic subclinical inflammation. Interactions between diet, adiposity, and gut microbiota modulate intestinal permeabilityand bacterial product translocation, and may contribute to the chronic inflammation process associated with the polycystic ovary syndrome. In the present study, we aimed to address the effects of obesity, functional hyperandrogenism, and diverse oral macronutrients on intestinal permeabilityby measuring circulating markers of gut barrier dysfunction and endotoxemia. Participants included 17 non-hyperandrogenic control women, 17 women with polycystic ovary syndrome, and 19 men that were submitted to glucose, lipid, and protein oral loads. Lipopolysaccharide-binding protein, plasma soluble CD14, succinate, zonulin family peptide, and glucagon-like peptide-2 were determined at fasting and after oral challenges. Macronutrient challenges induced diverse changes on circulating intestinal permeabilitybiomarkers in the acute postprancial period, with lipids and proteins showing the most unfavorable and favorable effects, respectively. Particularly, lipopolysaccharide-binding protein, zonulin family peptide, and glucagon-like peptide-2 responses were deregulated by the presence of obesity after glucose and lipid challenges. Obese subjects showed higher fasting intestinal permeabilitybiomarkers levels than non-obese individuals, except for plasma soluble CD14. The polycystic ovary syndromeexacerbated the effect of obesity further increasing fasting glucagon-like peptide-2, lipopolysaccharide-binding protein, and succinate concentrations. We observed specific interactions of the polycystic ovary syndromewith obesity in the postprandial response of succinate, zonulin family peptide, and glucagon-like peptide-2. In summary, obesity and polycystic ovary syndromemodify the effect of diverse macronutrients on the gut barrier, and alsoinfluence intestinal permeabilityat fasting,contributing to the morbidity of functional hyperandrogenism by inducing endotoxemia and subclinical chronic inflammation.
Topics: Humans; Polycystic Ovary Syndrome; Female; Adult; Permeability; Obesity; Fasting; Male; Glucagon-Like Peptide 2; Intestinal Mucosa; Gastrointestinal Microbiome; Nutrients; Young Adult; Haptoglobins; Endotoxemia; Lipopolysaccharide Receptors; Acute-Phase Proteins; Biomarkers; Membrane Glycoproteins; Dietary Fats; Glucose; Intestinal Barrier Function; Carrier Proteins; Protein Precursors
PubMed: 38729719
DOI: 10.1016/j.foodres.2024.114338 -
Nutrients Sep 2023Sugar-rich diets, but also the use of intense sweeteners, may alter intestinal barrier function. Here, we assessed the effect of sucrose and sucralose on post-prandial... (Randomized Controlled Trial)
Randomized Controlled Trial
Sugar-rich diets, but also the use of intense sweeteners, may alter intestinal barrier function. Here, we assessed the effect of sucrose and sucralose on post-prandial endotoxemia in a randomized placebo-controlled single-blinded crossover-designed study. Following a 2-day standardization of their diet, healthy men and women received a beverage containing either sucrose, sucralose (iso-sweet) or an isocaloric combination of sucralose + maltodextrin. Plasma endotoxin levels were measured after consumption of the respective beverages. Moreover, the effect of sucrose and sucralose on intestinal permeability was assessed in Caco-2 cells and ex vivo in an everted gut sac model. The nutritional standardization recommended by nutrition societies was associated with a significant decrease in plasma endotoxin levels. The intake of the sucrose-sweetened beverage resulted in a significant increase in plasma endotoxin levels while being unchanged after the intake of sucralose-sweetened beverages. In Caco-2 cells, the challenge with sucrose but not with sucralose significantly increased the permeation of the bacterial endotoxin across the cell monolayer. Xylose permeation in small intestinal everted tissue sacs was significantly higher upon the challenge with sucrose while remaining unchanged in sucralose-challenged sacs. Our data suggest that an acute intake of physiologically relevant amounts of sucrose but not of sucralose can result in post-prandial endotoxemia.
Topics: Male; Female; Young Adult; Humans; Sweetening Agents; Endotoxemia; Caco-2 Cells; Sucrose; Endotoxins; Excipients
PubMed: 37764821
DOI: 10.3390/nu15184038