Cell death induced by NLRP3-palmitate axis impairs pulmonary damage tolerance and aggravates immunopathology during obesity-tuberculosis comorbidity.

A low-grade and persistent inflammation, which is the hallmark of obesity, requires the participation of NLRP3 and cell death. During Mycobacterium tuberculosis infection, NLRP3 signaling is important for bacterial killing by macrophages in vitro but was shown to be dispensable for host protection in vivo. We hypothesized that during obesity-tuberculosis (TB) comorbidity, NLRP3 signaling might play a detrimental role by inducing excessive inflammation. We employed a model of high-fat-diet-induced obesity, followed by M. tuberculosis infection in C57BL/6 mice. Obese mice presented increased susceptibility to infection and pulmonary immunopathology compared to lean mice. Using treatment with NLRP3 antagonist and Nlrp3-/- mice, we showed that NLRP3 signaling promoted cell death, with no effect in bacterial loads. The levels of palmitate were higher in the lungs of obese infected mice compared to lean counterparts, and we observed that this lipid increased M. tuberculosis-induced macrophage death in vitro, which was dependent on NLRP3 and caspase-1. At the chronic phase, although lungs of obese Nlrp3-/- mice showed an indication of granuloma formation compared to obese wild-type mice, there was no difference in the bacterial load. Our findings indicate that NLRP3 may be a potential target for host-directed therapy to reduce initial and severe inflammation-mediated disease and to treat comorbidity-associated TB. © 2022 The Pathological Society of Great Britain and Ireland.

Ethanol: striking the cardiovascular system by harming the gut microbiota.

Ethanol consumption represents a significant public health problem, and excessive ethanol intake is a risk factor for cardiovascular disease (CVD), one of the leading causes of death and disability worldwide. The mechanisms underlying the effects of ethanol on the cardiovascular system are complex and not fully comprehended. The gut microbiota and their metabolites are indispensable symbionts essential for health and homeostasis and therefore, have emerged as potential contributors to ethanol-induced cardiovascular system dysfunction. By mechanisms that are not completely understood, the gut microbiota modulates the immune system and activates several signaling pathways that stimulate inflammatory responses, which in turn, contribute to the development and progression of CVD. This review summarizes preclinical and clinical evidence on the effects of ethanol in the gut microbiota and discusses the mechanisms by which ethanol-induced gut dysbiosis leads to the activation of the immune system and cardiovascular dysfunction. The cross talk between ethanol consumption and the gut microbiota and its implications are detailed. In summary, an imbalance in the symbiotic relationship between the host and the commensal microbiota in a holobiont, as seen with ethanol consumption, may contribute to CVD. Therefore, manipulating the gut microbiota, by using antibiotics, probiotics, prebiotics, and fecal microbiota transplantation might prove a valuable opportunity to prevent/mitigate the deleterious effects of ethanol and improve cardiovascular health and risk prevention.

Curcuma supplementation in high-fat-fed C57BL/6 mice: no beneficial effect on lipid and glucose profile or prevention of weight gain.

PURPOSE: This experimental study investigated the effects of curcuma supplementation on weight gain, Body Adiposity Index, glucose and lipid profile, and liver and pancreas histology in C57BL/6 mice fed with a high-fat diet. METHODS: 40 animals were separated into four groups: standard diet (SD), standard diet plus curcuma (SD + C), high-fat diet (HFD), and high-fat diet plus curcuma (HFD + C). Curcuma dose was 8 mg/animal/day. Histological and biochemical analyses were performed at the end of the experimental period. RESULTS: Curcuma prevented weight gain, despite a higher food intake, and increased brown adipose tissue weight only in mice receiving standard diet. However, these changes were not observed in HFD + C group. The groups that received curcuma (SD + C and HFD + C) showed a pancreas with diffuse macro- and microgoticular steatosis. CONCLUSIONS: Curcuma supplementation did not prevent weight gain or improved glucose and lipid profile in mice receiving high-fat diet. Furthermore, there was evidence of possible curcuma toxicity in the pancreas of C57BL/6 mice. The implications of these findings on humans still need to be investigated.

Transvaginal repair of Neobladder Vaginal Fistula with Martius Flap.

Introduction: Neobladder vaginal fistula (NVF) is a known complication after cystectomy and orthotopic diversion in women, occurring in 3-5% of women. Possible risk factors for fistula formation include compromised tissue vascularity due to surgical dissection and/or radiotherapy, suture line proximity, local tissue recurrence, and injury to the vaginal wall during dissection. The surgical repair of a NVF can be challenging secondary to vaginal shortening, atrophy, local inflammation from chronic exposure to urinary leakage, and the proximity of the neobladder to the anterior vaginal wall. In this video, we present transvaginal repair of a NVF with Martius flap interposition. Materials and Methods: This is the case of a 47 year old woman with a history of radical cystectomy and creation of a Studer pouch secondary to bladder cancer two years prior who subsequently developed a NVF. Evaluation included an office cystoscopy which demonstrated a 3-4mm left-sided neobladder vaginal fistula at the level of the ileal-urethral anastomosis. No pelvic organ prolapse or evidence of bladder cancer recurrence was appreciated. Results: A vaginal approach for the NVF repair was performed with a Martius flap interposition. A water-tight closure was achieved without any intraoperative or immediate postoperative complications. The urethral Foley was removed at 2 weeks and by 4 weeks the patient did not report any urinary leakage. Conclusions: Neobladder vaginal fistula is a rare complication following cystectomy and orthotopic urinary diversion that can be repaired using a transvaginal approach. A Martius flap interposition is important to augment success of the repair. If a transvaginal approach fails a transabdominal approach or conversion to cutaneous diversion may be necessary.

Interleukin-17/interleukin-17 receptor axis elicits intestinal neutrophil migration, restrains gut dysbiosis and lipopolysaccharide translocation in high-fat diet-induced metabolic syndrome model.

Sound evidence supports a role for interleukin-17 (IL-17) -producing γδ T cells and IL-17-producing helper T (Th17) cells in intestinal homeostasis, especially in intestinal barrier integrity. In the present study, we aimed to evaluate the role of IL-17 cytokine in the regulation of intestinal immunity and obesity-induced metabolic syndrome (MetS) in an experimental murine model. C57BL/6 wild-type (WT) mice and mice lacking the IL-17 cytokine receptor (IL-17RA-/- ) were fed either a control diet (CD) or a high-fat diet (HFD) for 9 weeks. Our data demonstrate that IL-17RA-/- mice are protected against obesity, but develop hyperglycemia, hyperinsulinemia and insulin resistance. In parallel, HFD-fed IL-17RA-/- mice display intense inflammation in the ileum compared with WT mice on the HFD. IL-17RA-/- mice fed the HFD exhibit impaired neutrophil migration to the intestinal mucosa and reduced gene expression of the CXCL-1 chemokine and CXCR-2 receptor in the ileum. Interestingly, the populations of neutrophils (CD11b+  Ly6G+ ) and anti-inflammatory macrophages (CD11b+  CX3CR1+ ) are increased in the mesenteric lymph nodes of these mice. IL-17RA-/- mice on the HFD also display increased commensal bacterial translocation into the bloodstream and elevated lipopolysaccharide (LPS) levels in the visceral adipose tissue (VAT). Metagenomic analysis of bacterial 16S gene revealed increased Proteobacteria and Bacteroidetes phyla, the main representatives of Gram-negative bacteria, and reduced Akkermansia muciniphila in the fecal samples of IL-17RA-/- mice fed the HFD. Together, these data indicate that the IL-17/IL-17R axis drives intestinal neutrophil migration, limits gut dysbiosis and attenuates LPS translocation to VAT, resulting in protection to MetS.

Interleukin-23 promotes intestinal T helper type17 immunity and ameliorates obesity-associated metabolic syndrome in a murine high-fat diet model.

We addressed the role of interleukin-23 (IL-23) in driving the intestinal T helper type 17 (Th17) response during obesity and metabolic syndrome progression induced by a high-fat diet (HFD). Diet-induced obese and lean mice received HFD or control diet (CTD), respectively, for 20 weeks. The nutritional, metabolic and immune parameters were examined at weeks 9 and 20. Gene and protein IL-23p19 and IL-23 receptor expression was increased in the ileum of obese wild-type mice (WT) fed the HFD for 9 weeks. Mice lacking IL-23 and fed the HFD exhibited greater weight gain, higher fat accumulation, adipocyte hypertrophy and hepatic steatosis. Notably, these mice had more glucose intolerance, insulin resistance and associated metabolic alterations, such as hyperinsulinaemia and hyperlipidaemia. IL-23 deficiency also significantly reduced protein levels of IL-17, CCL20 and neutrophil elastase in the ileum and reduced Th17 cell expansion in the mesenteric lymph nodes of the HFD mice. Of importance, IL-23-deficient mice exhibited increased gut permeability and blood bacterial translocation compared with WT mice fed HFD. Finally, metagenomics analysis of gut microbiota revealed a dramatic outgrowth of Bacteroidetes over Firmicutes phylum with the prevalence of Bacteroides genera in the faeces of IL-23-deficient mice after HFD. In summary, IL-23 appears to maintain the Th17 response and neutrophil migration into the intestinal mucosa, minimizing the gut dysbiosis and protecting against obesity and metabolic disease development in mice.

Risk factors for explantation due to infection after sacral neuromodulation: a multicenter retrospective case-control study.

BACKGROUND: Sacral neuromodulation is an effective therapy for overactive bladder, urinary retention, and fecal incontinence. Infection after sacral neurostimulation is costly and burdensome. Determining optimal perioperative management strategies to reduce the risk of infection is important to reduce this burden. OBJECTIVE: We sought to identify risk factors associated with sacral neurostimulator infection requiring explantation, to estimate the incidence of infection requiring explantation, and identify associated microbial pathogens. STUDY DESIGN: This is a multicenter retrospective case-control study of sacral neuromodulation procedures completed from Jan. 1, 2004, through Dec. 31, 2014. We identified all sacral neuromodulation implantable pulse generator implants as well as explants due to infection at 8 participating institutions. Cases were patients who required implantable pulse generator explantation for infection during the review period. Cases were included if age ≥18 years old, follow-up data were available ≥30 days after implantable pulse generator implant, and the implant was performed at the institution performing the explant. Two controls were matched to each case. These controls were the patients who had an implantable pulse generator implanted by the same surgeon immediately preceding and immediately following the identified case who met inclusion criteria. Controls were included if age ≥18 years old, no infection after implantable pulse generator implant, follow-up data were available ≥180 days after implant, and no explant for any reason <180 days from implant. Controls may have had an explant for reasons other than infection at >180 days after implant. Fisher exact test (for categorical variables) and Student t test (for continuous variables) were used to test the strength of the association between infection and patient and surgery characteristics. Significant variables were then considered in a multivariable logistic regression model to determine risk factors independently associated with infection. RESULTS: Over a 10-year period at 8 academic institutions, 1930 sacral neuromodulator implants were performed by 17 surgeons. In all, 38 cases requiring device explant for infection and 72 corresponding controls were identified. The incidence of infection requiring explant was 1.97%. Hematoma formation (13% cases, 0% controls; P = .004) and pocket depth of ≥3 cm (21% cases, 0% controls; P = .031) were independently associated with an increased risk of infection requiring explant. On multivariable regression analysis controlling for significant variables, both hematoma formation (P = .006) and pocket depth ≥3 cm (P = .020, odds ratio 3.26; 95% confidence interval, 1.20-8.89) remained significantly associated with infection requiring explant. Of the 38 cases requiring explant, 32 had cultures collected and 24 had positive cultures. All 5 cases with a hematoma had a positive culture (100%). Of the 4 cases with a pocket depth ≥3 cm, 2 had positive cultures, 1 had negative cultures, and 1 had a missing culture result. The most common organism identified was methicillin-resistant Staphylococcus aureus (38%). CONCLUSION: Infection after sacral neuromodulation requiring device explant is low. The most common infectious pathogen identified was methicillin-resistant S aureus. Demographic and health characteristics did not predict risk of explant due to infection, however, having a postoperative hematoma or a deep pocket ≥3 cm significantly increased the risk of explant due to infection. These findings highlight the importance of meticulous hemostasis as well as ensuring the pocket depth is <3 cm at the time of device implant.

NLRP3 Inflammasome Mediates Aldosterone-Induced Vascular Damage.

BACKGROUND: Inflammation is a key feature of aldosterone-induced vascular damage and dysfunction, but molecular mechanisms by which aldosterone triggers inflammation remain unclear. The NLRP3 inflammasome is a pivotal immune sensor that recognizes endogenous danger signals triggering sterile inflammation. METHODS: We analyzed vascular function and inflammatory profile of wild-type (WT), NLRP3 knockout (NLRP3-/-), caspase-1 knockout (Casp-1-/-), and interleukin-1 receptor knockout (IL-1R-/-) mice treated with vehicle or aldosterone (600 µg·kg-1·d-1 for 14 days through osmotic mini-pump) while receiving 1% saline to drink. RESULTS: Here, we show that NLRP3 inflammasome plays a central role in aldosterone-induced vascular dysfunction. Long-term infusion of aldosterone in mice resulted in elevation of plasma interleukin-1ß levels and vascular abnormalities. Mice lacking the IL-1R or the inflammasome components NLRP3 and caspase-1 were protected from aldosterone-induced vascular damage. In vitro, aldosterone stimulated NLRP3-dependent interleukin-1ß secretion by bone marrow-derived macrophages by activating nuclear factor-κB signaling and reactive oxygen species generation. Moreover, chimeric mice reconstituted with NLRP3-deficient hematopoietic cells showed that NLRP3 in immune cells mediates aldosterone-induced vascular damage. In addition, aldosterone increased the expression of NLRP3, active caspase-1, and mature interleukin-1ß in human peripheral blood mononuclear cells. Hypertensive patients with hyperaldosteronism or normal levels of aldosterone exhibited increased activity of NLRP3 inflammasome, suggesting that the effect of hyperaldosteronism on the inflammasome may be mediated through high blood pressure. CONCLUSIONS: Together, these data demonstrate that NLRP3 inflammasome, through activation of IL-1R, is critically involved in the deleterious vascular effects of aldosterone, placing NLRP3 as a potential target for therapeutic interventions in conditions with high aldosterone levels.

Mast cells control insulitis and increase Treg cells to confer protection against STZ-induced type 1 diabetes in mice.

Quantitative alterations in mast cell numbers in pancreatic lymph nodes (PLNs) have been reported to be associated with type 1 diabetes (T1D) progression, but their potential role during T1D remains unclear. In this study, we evaluated the role of mast cells in T1D induced by multiple low-dose streptozotocin (MLD-STZ) treatments, using two strains of mast cell-deficient mice (W/W(v) or Wsh/Wsh) and the adoptive transfer of mast cells. Mast cell deficient mice developed severe insulitis and accelerated hyperglycemia, with 100% of mice becoming diabetic compared to their littermates. In parallel, these diabetic mice had decreased numbers of T regulatory (Treg) cells in the PLNs. Additionally, mast cell deficiency caused a significant reduction in IL-10, TGF-ß, and IL-6 expression in the pancreatic tissue. Interestingly, IL-6-deficient mice are more susceptible to T1D associated with reduced Treg-cell numbers in the PLNs, but mast cell transfer from wild-type mice induced protection to T1D in these mice. Finally, mast cell adoptive transfer prior to MLD-STZ administration conferred resistance to T1D, promoted increased Treg cells, and decreased IL-17-producing T cells in the PLNs. Taken together, our results indicate that mast cells are implicated in resistance to STZ-induced T1D via an immunological tolerance mechanism mediated by Treg cells.

Histamine h2 receptor signaling in the pathogenesis of sepsis: studies in a murine diabetes model.

Type 1 diabetes enhances susceptibility to infection and favors the sepsis development. In addition, diabetic mice produced higher levels of histamine in several tissues and in the blood after LPS stimulation than nondiabetic mice. In this study, we aimed to explore the role of mast cells (MCs) and histamine in neutrophil migration and, consequently, infection control in diabetic mice with mild sepsis (MS) induced by cecum ligation and puncture. We used female BALB/c, MC-sufficient (WB/B6), MC-deficient (W/W(v)), and NOD mice. Diabetic mice given MS displayed 100% mortality within 24 h, whereas all nondiabetic mice survived for at least 5 d. The mortality rate of diabetic mice was reduced to 57% after the depletion of MC granules with compound 48/80. Moreover, this pretreatment increased neutrophil migration to the focus of infection, which reduced systemic inflammatory response and bacteremia. The downregulation of CXCR2 and upregulation of G protein-coupled receptor kinase 2 in neutrophils was prevented by pretreatment of diabetic mice given MS with compound 48/80. In addition, blocking the histamine H2 receptor restored neutrophil migration, enhanced CXCR2 expression, decreased bacteremia, and improved sepsis survival in alloxan-induced diabetic and spontaneous NOD mice. Finally, diabetic W/W(v) mice had neutrophil migration to the peritoneal cavity, increased CXCR2 expression, and reduced bacteremia compared with diabetic WB/B6 mice. These results demonstrate that histamine released by MCs reduces diabetic host resistance to septic peritonitis in mice.

The IL-33/ST2 pathway controls coxsackievirus B5-induced experimental pancreatitis.

Coxsackievirus B (CVB) is a common cause of acute and chronic infectious myocarditis and pancreatitis. Th1 cells producing IFN-γ and TNF-α are important for CVB clearance, but they are also associated with the pathogenesis of inflammatory lesions, suggesting that the modulation of Th1 and Th2 balance is likely important in controlling CVB-induced pancreatitis. We investigated the role of IL-33, which is an important recently discovered cytokine for induction of Th2-associated responses, in experimental CVB5 infection. We found that mice deficient in IL-33R, T1/ST2, significantly developed more severe pancreatitis, had greater weight loss, and contained higher viral load compared with wild-type (WT) mice when infected with CVB5. Conversely, WT mice treated with rIL-33 developed significantly lower viral titers, and pancreatitis was attenuated. Mechanistic studies demonstrated that IL-33 enhances the degranulation and production of IFN-γ and TNF-α by CD8(+) T and NK cells, which is associated with viral clearance. Furthermore, IL-33 triggers the production of IL-4 from mast cells, which results in enhanced differentiation of M2 macrophages and regulatory T cells, leading to the attenuation of inflammatory pancreatitis. Adoptively transferred mast cells or M2 macrophages reversed the heightened pancreatitis in the T1/ST2(-/-) mice. In contrast, inhibition of regulatory T cells exacerbated the disease in WT mice. Together, our findings reveal an unrecognized IL-33/ST2 functional pathway and a key mechanism for CVB5-induced pancreatitis. These data further suggest a novel approach in treating virus-induced pancreatitis, which is a major medical condition with unmet clinical needs.

IL-1 Receptor Contributes to the Maintenance of the Intestinal Barrier via IL-22 during Obesity and Metabolic Syndrome in Experimental Model.

Intestinal permeability and bacterial translocation are increased in obesity and metabolic syndrome (MS). ILC3 cells contribute to the integrity of intestinal epithelium by producing IL-22 via IL-1ß and IL-23. This study investigates the role of IL-1R1 in inducing ILC3 cells and conferring protection during obesity and MS. For this purpose, C57BL/6 wild-type (WT) and IL-1R1-deficient mice were fed a standard diet (SD) or high-fat diet (HFD) for 16 weeks. Weight and blood glucose levels were monitored, and adipose tissue and blood samples were collected to evaluate obesity and metabolic parameters. The small intestine was collected to assess immunological and junction protein parameters through flow cytometry and RT-PCR, respectively. The intestinal permeability was analyzed using the FITC-dextran assay. The composition of the gut microbiota was also analyzed by qPCR. We found that IL-1R1 deficiency exacerbates MS in HFD-fed mice, increasing body fat and promoting glucose intolerance. A worsening of MS in IL-1R1-deficient mice was associated with a reduction in the ILC3 population in the small intestine. In addition, we found decreased IL-22 expression, increased intestinal permeability and bacterial translocation to the visceral adipose tissue of these mice compared to WT mice. Thus, the IL-1R1 receptor plays a critical role in controlling intestinal homeostasis and obesity-induced MS, possibly through the differentiation or activation of IL-22-secreting ILC3s.

Association between the relative abundance of phyla actinobacteria, vitamin C consumption, and DNA methylation of genes linked to immune response pathways.

Introduction: There is an emerging body of evidence that vitamin C consumption can modulate microbiota abundance and can also impact DNA methylation in the host, and this could be a link between diet, microbiota, and immune response. The objective of this study was to evaluate common CpG sites associated with both vitamin C and microbiota phyla abundance. Methods: Six healthy women participated in this cohort study. They were divided into two groups, according to the amount of vitamin C they ingested. Ingestion was evaluated using the 24-h recall method. The Illumina 450 k BeadChip was used to evaluate DNA methylation. Singular value decomposition analyses were used to evaluate the principal components of this dataset. Associations were evaluated using the differentially methylated position function from the Champ package for R Studio. Results and discussion: The group with higher vitamin C (HVC) ingestion also had a higher relative abundance of Actinobacteria. There was a positive correlation between those variables (r = 0.84, p = 0.01). The HVC group also had higher granulocytes, and regarding DNA methylation, there were 207 CpG sites commonly related to vitamin C ingestion and the relative abundance of Actinobacteria. From these sites, there were 13 sites hypomethylated and 103 hypermethylated. The hypomethylated targets involved the respective processes: immune function, glucose homeostasis, and general cellular metabolism. The hypermethylated sites were also enriched in immune function-related processes, and interestingly, more immune responses against pathogens were detected. These findings contribute to understanding the interaction between nutrients, microbiota, DNA methylation, and the immune response.

Inulin prebiotic ameliorates type 1 diabetes dictating regulatory T cell homing via CCR4 to pancreatic islets and butyrogenic gut microbiota in murine model.

Gut dysbiosis is linked to type 1 diabetes mellitus (T1D). Inulin (INU), a prebiotic, modulates the gut microbiota, promoting beneficial bacteria that produce essential short-chain fatty acids for immune regulation. However, how INU affects T1D remains uncertain. Using a streptozotocin-induced (STZ) mouse model, we studied INU's protective effects. Remarkably, STZ + INU mice resisted T1D, with none developing the disease. They had lower blood glucose, reduced pancreatic inflammation, and normalized serum insulin compared with STZ + SD mice. STZ + INU mice also had enhanced mucus production, abundant Bifidobacterium, Clostridium cluster IV, Akkermansia muciniphila, and increased fecal butyrate. In cecal lymph nodes, we observed fewer CD4+Foxp3+ regulatory T cells expressing CCR4 and more Foxp3+CCR4+ cells in pancreatic islets, with higher CCL17 expression. This phenotype was absent in CCR4-deficient mice on INU. INU supplementation effectively protects against experimental T1D by recruiting CCR4+ regulatory T cells via CCL17 into the pancreas and altering the butyrate-producing microbiota.

The Dose-Dependent Effect of Curcumin Supplementation on Inflammatory Response and Gut Microbiota Profile in High-Fat Fed C57BL/6 Mice.

SCOPE: The prevalence of obesity has increased, with excessive consumption of high-fat foods being one of the primary causes. Curcumin, a polyphenol extracted from Curcuma longa L., exhibits anti-inflammatory activity.  The study aims to investigate the effects of curcumin supplementation in different doses on the biochemical profile, inflammatory response, and gut microbiota profile in mice that are fed with high-fat diet (HFD). METHODS AND RESULTS: C57BL/6 male mice are fed a standard diet, or a HFD with or without different doses of curcumin (50, 250, and 500 mg kg-1 of body weight). Throughout the experimental period, food intake and body weight are assessed weekly. At euthanasia, blood, stool, and tissue samples are collected for biochemical, histological, and molecular analyses. Curcumin increases the IL-10 protein expression in the white adipose tissue. In the liver, there is a reduction in tumor necrosis factor alpha (TNF-α) and an increase in IL-10 gene expression. Also, curcumin promotes the growth of butyrogenic bacteria, such as Clostridium clusters IV and XIVa. CONCLUSIONS: The findings suggest that curcumin has the potential to improve the inflammatory response and modulate healthy gut microbiota. Further studies are needed to clarify the role of curcumin as a preventive and effective strategy for obesity.

The Microbiota-Dependent Worsening Effects of Melatonin on Gut Inflammation.

Dysbiosis and disturbances in gut homeostasis may result in dysregulated responses, which are common in inflammatory bowel diseases (IBD). These conditions may be refractory to the usual treatments and novel therapies are still necessary to reach a more successful regulation of intestinal immunity. The hormone melatonin (MLT) has been raised as a therapeutic alternative because of its known interactions with immune responses and gut microbiota. Hence, we evaluated the effects of MLT in experimental colitis that evolves with intestinal dysbiosis, inflammation and bacterial translocation. C57BL/6 mice were exposed to dextran sulfate sodium and treated with MLT. In acute colitis, the hormone led to increased clinical, systemic and intestinal inflammatory parameters. During remission, continued MLT administration delayed recovery, increased TNF, memory effector lymphocytes and diminished spleen regulatory cells. MLT treatment reduced Bacteroidetes and augmented Actinobacteria and Verrucomicrobia phyla in mice feces. Microbiota depletion resulted in a remarkable reversion of the colitis phenotype after MLT administration, including a counter-regulatory immune response, reduction in TNF and colon macrophages. There was a decrease in Actinobacteria, Firmicutes and, most strikingly, Verrucomicrobia phylum in recovering mice. Finally, these results pointed to a gut-microbiota-dependent effect of MLT in the potentiation of intestinal inflammation.

AT1 receptors modulate ethanol-induced loss of anticontractile effect of perivascular adipose tissue.

Ethanol consumption activates renin-angiotensin-aldosterone system (RAAS), which plays a major role in the pro-contractile and hypertensive effects linked to ethanol. We hypothesized that ethanol consumption induces loss of the anticontractile effect of perivascular adipose tissue (PVAT)through RAAS-mediated mechanisms. We examined the contribution of angiotensin II type 1 receptors (AT1R) to ethanol-induced PVAT dysfunction. With this purpose, male Wistar Hannover rats were treated with ethanol 20 % (in volume ratio) and/or losartan (antagonist of AT1R; 10 mg/kg/day, gavage) for 9 weeks. Losartan prevented the increase in blood pressure and the loss of the anticontractile effect of PVAT induced by ethanol consumption. PVAT dysfunction occurred after 3 and 9 weeks of treatment with ethanol in an endothelium-dependent manner. Blockade of AT1R prevented ethanol-induced reduction of adiponectin levels in PVAT from ethanol-treated rats. Functional assays revealed that ethanol impaired the anticontractile effect of PVAT-derived angiotensin (1-7) and endothelial nitric oxide (NO). In conclusion, AT1R are implicated in ethanol-induced loss of the anticontractile effect of PVAT. In PVAT, AT1R activation decreases the production of adiponectin, a PVAT-derived factor that promotes vasorelaxation in an endothelium-dependent manner. In the endothelium, AT1R favors the production of superoxide (O2•-) leading to a reduction in NO bioavailability. These responses impair the vasodilator action induced by PVAT-derived angiotensin (1-7), which occurs via Mas receptors located in endothelial cells. Ethanol-induced PVAT dysfunction favors vascular hypercontractility, a response that could contribute to the hypertensive state associated with ethanol consumption.

AIM2 promotes TH17 cells differentiation by regulating RORγt transcription activity.

AIM2 is an interferon-inducible HIN-200 protein family member and is well-documented for its roles in innate immune responses as a DNA sensor. Recent studies have highlighted AIM2's function on regulatory T cells (Treg) and follicular T cells (Tfh). However, its involvement in Th17 cell differentiation remains unclear. This study reveals that AIM2 promotes Th17 cell differentiation. AIM2 deficiency decreases IL-17A production and downregulates key Th17 associated proteins (RORγt, IL-1R1, IL-23R). AIM2 is located in the nucleus of Th17 cells, where it interacts with RORγt, enhancing its binding to the Il17a promoter. The absence of AIM2 hinders naive CD4 T cells from differentiating into functional Th17 cells and from inducing colitis in Rag1-/- mice. This study uncovers AIM2's role as a regulator of Th17 cell transcriptional programming, highlighting its potential as a therapeutic target for Th17 cell-mediated inflammatory diseases.

Xenogeneic mesenchymal stem cell biocurative improves skin wounds healing in diabetic mice by increasing mast cells and the regenerative profile.

Introduction: Diabetes mellitus (DM) is a chronic disease and a major cause of mortality and morbidity worldwide. The hyperglycemia caused by DM induces micro and macrovascular complications that lead, among other consequences, to chronic wounds and amputations. Cell therapy and tissue engineering constitute recent therapeutic alternatives to improve wound healing in diabetic patients. The current study aimed to analyze the effectiveness of biocuratives containing human mesenchymal stem cells (MSCs) associated with a hydrogel matrix in the wound healing process and related inflammatory cell profile in diabetic mice. Methods: Biocuratives containing MSCs were constructed by 3D bioprinting, and applied to skin wounds on the back of streptozotocin (STZ)-induced type 1 diabetic (T1D) mice. The healing process, after the application of biocuratives with or without MSCs was histologically analyzed. In parallel, genes related to growth factors, mast cells (MC), M1 and M2 macrophage profiles were evaluated by RT-PCR. Macrophages were characterized by flow cytometry, and MC by toluidine blue staining and flow cytometry. Results: Mice with T1D exhibited fewer skin MC and delayed wound healing when compared to the non-diabetic group. Treatment with the biocuratives containing MSCs accelerated wound healing and improved skin collagen deposition in diabetic mice. Increased TGF-ß gene expression and M2 macrophage-related markers were also detected in skin of diabetic mice that received MSCs-containing biocuratives. Finally, MSCs upregulated IL-33 gene expression and augmented the number of MC in the skin of diabetic mice. Conclusion: These results reveal the therapeutic potential of biocuratives containing MSCs in the healing of skin wounds in diabetic mice, providing a scientific base for future treatments in diabetic patients.

Eicosapentaenoic acid-rich oil supplementation activates PPAR-γ and delays skin wound healing in type 1 diabetic mice.

Delayed wound healing is a devastating complication of diabetes and supplementation with fish oil, a source of anti-inflammatory omega-3 (ω-3) fatty acids including eicosapentaenoic acid (EPA), seems an appealing treatment strategy. However, some studies have shown that ω-3 fatty acids may have a deleterious effect on skin repair and the effects of oral administration of EPA on wound healing in diabetes are unclear. We used streptozotocin-induced diabetes as a mouse model to investigate the effects of oral administration of an EPA-rich oil on wound closure and quality of new tissue formed. Gas chromatography analysis of serum and skin showed that EPA-rich oil increased the incorporation of ω-3 and decreased ω-6 fatty acids, resulting in reduction of the ω-6/ω-3 ratio. On the tenth day after wounding, EPA increased production of IL-10 by neutrophils in the wound, reduced collagen deposition, and ultimately delayed wound closure and impaired quality of the healed tissue. This effect was PPAR-γ-dependent. EPA and IL-10 reduced collagen production by fibroblasts in vitro. In vivo, topical PPAR-γ-blockade reversed the deleterious effects of EPA on wound closure and on collagen organization in diabetic mice. We also observed a reduction in IL-10 production by neutrophils in diabetic mice treated topically with the PPAR-γ blocker. These results show that oral supplementation with EPA-rich oil impairs skin wound healing in diabetes, acting on inflammatory and non-inflammatory cells.