Gut barrier disruption is often implicated in pathogenesis associated with burn and other traumatic injuries. In this study, the authors examined whether therapeutic intervention with mesalamine (5-aminosalicylic acid [5-ASA]), a common anti-inflammatory treatment for patients with inflammatory bowel disease, reduces intestinal inflammation and maintains normal barrier integrity after burn injury. Male C57BL/6 mice were administered an approximately 20% TBSA dorsal scald burn and resuscitated with either 1 ml normal saline or 100 mg/kg of 5-ASA dissolved in saline. The authors examined intestinal transit and permeability along with the levels of small intestine epithelial cell proinflammatory cytokines and tight junction protein expression 1 day after burn injury in the presence or absence of 5-ASA. A significant decrease in intestinal transit was observed 1 day after burn injury, which accompanied a significant increase in gut permeability. The authors found a substantial increase in the levels of interleukin (IL)-6 (by ∼1.5-fold) and IL-18 (by ∼2.5-fold) in the small intestine epithelial cells 1 day after injury. Furthermore, burn injury decreases the expression of the tight junction proteins claudin-4, claudin-8, and occludin. Treatment with 5-ASA after burn injury prevented the burn-induced increase in permeability, partially restored normal intestinal transit, normalized the levels of the proinflammatory cytokines IL-6 and IL-18, and restored tight junction protein expression of claudin-4 and occludin compared with that of sham levels. Together these findings suggest that 5-ASA can potentially be used as treatment to decrease intestinal inflammation and normalize intestinal function after burn injury.
Recent studies indicate that toll-like receptors (TLRs) are expressed on T cells and that these receptors directly or indirectly activate the adaptive immune system. We have shown previously that acute alcohol/ethanol (EtOH) intoxication combined with burn injury suppresses mesenteric lymph node (MLN) T-cell interleukin-2 (IL-2) and interferon γ (IFN-γ) production. We examined whether direct stimulation of T cells with TLR2, 4, 5 and 7 agonists modulates CD3-mediated T-cell IL-2/IFN-γ release following EtOH and burn injury. Male mice were gavaged with EtOH (2.9 gm/kg) 4 h prior to receiving an ~12.5% total body surface area sham or full-thickness burn injury. Animals were killed on d 1 after injury and T cells were purified from MLN and spleens. T cells were cultured with plate-bound anti-CD3 in the presence or absence of various TLR ligands. Although TLR2, 4 and 5 agonists potentiate anti-CD3-dependent IFN-γ by T cells, the TLR2 agonist alone induced IFN-γ production independent of CD3 stimulation. Furthermore, T cells were treated with inhibitors of myeloid differentiation primary response protein 88 (MyD88), TIR domain-containing adaptor protein (TIRAP), p38 and/or extracellular signal-regulated kinase (ERK) to determine the mechanism by which TLR2 mediates IL-2/IFN-γ production. IL-2 was not influenced by TLR agonists. MyD88 and TIRAP inhibitory peptides dose-dependently diminished the ability of T cells to release IFN-γ. p38 and ERK inhibitors also abolished TLR2-mediated T-cell IFN-γ. Together, our findings suggest that TLR2 directly modulates T-cell IFN-γ production following EtOH and burn injury, independent of antigen-presenting cells. Furthermore, we demonstrated that MyD88/TIRAP-dependent p38/ERK activation is critical to TLR2-mediated T-cell IFN-γ release following EtOH and burn injury.
BackgroundDiabetes mellitus is a commonly occurring metabolic disorder accompanied by high morbidity and alarming mortality. Besides various available therapies, induction of pancreatic regeneration has emerged as a promising strategy for alleviating the damaging effect of diabetes. Honey, a potent antioxidative and anti-inflammatory agent, has been reported in the literature archive to exhibit favourable results in the regeneration process of several organ systems.DesignThe current research work was intended to explore the potential role of manuka honey in pancreatic regeneration in alloxan-induced diabetic rats by accessing the pancreatic histology and levels of relevant transcription factors, including MAFA, PDX-1, INS-1, INS-2, NEUROG3, NKX6-1, and NEUROD. An equal number of rats were allocated to all four experimental groups: normal, negative control, positive control, and treatment group. Diabetes was induced in all groups except normal through a single intraperitoneal dose of alloxan monohydrate. No subsequent treatment was given to the negative control group, while the positive control and treatment groups were supplemented with metformin (150 mg/kg/day) and manuka honey (3 g/kg/day), respectively.ResultsStatistical comparison of glucose and insulin levels, oxidative stress indicators, changes in the architecture of pancreatic islets, and expression levels of regeneration-associated transcription factors advocated the potential role of manuka honey in ameliorating the alloxan-induced hyperglycaemia, hyperinsulinemia, oxidative stress, and necrotic changes in islets along with significant upregulation of relevant transcription factors.ConclusionThis suggests to us the auspicious role of antioxidants in honey in pancreatic regeneration and advocates the favourable role of manuka honey in combating diabetes mellitus.
Diabetic cardiomyopathy, a severe diabetic complication, impairs heart function, leading to heart failure. Treatment that effectively addresses this condition without causing side effects is urgently needed. Current anti-hyperglycemic therapies are expensive, has side effects and do not effectively prevent cardiac remodeling. Therefore, it is important to explore natural products that may have the potential to reverse cardiac remodeling. That is why the aim of the current study was to determine the left ventricular remodeling potential of the methanolic extract of Artemisia vulgaris in a diabetic cardiomyopathy rat model. Following the initial comprehensive phytochemical evaluation of plant phenolic and flavonoid content, which showed strong anti-hyperglycemic and antioxidant activities, an extract of Artemisia vulgaris was administered in an in vivo experiment. Diabetic cardiomyopathy was induced in Wistar albino rats according to previously described protocols in the literature, and the effect of treatment was checked by serum and histopathological analysis after 45 days. Artemisia vulgaris treatment significantly (p ≤ 0.05) reduced fasting blood glucose (108.5 ± 1.75 mg/dL), glycated hemoglobin (4.03 ± 0.12 %), serum glucose (116.66 ± 3.28 mg/dL), insulin (15.66 ± 0.66 ng/mL), total oxidant status (54.66 ± 3.22 µmol H2O2Equiv.L−1), Malondialdehyde (0.20 ± 0.01 mmol/L), total cholesterol (91.16 ± 3.35 mg/dL), triglycerides (130.66 ± 3.15 mg/dL), low-density lipids (36.57 ± 1.02 mg/dL), sodium (140 ± 3.21 mmol/L), calcium (10.44 ± 0.24 mmol/L), creatine kinase MB (1227.5 ± 17.89 IU/L), lactate dehydrogenase (1300 ± 34.64 IU/L), C-reactive protein (30 ± 0.57 pg/mL), tumor necrosis factor-α (58.66 ± 1.76 pg/mL), atrial natriuretic peptide (2.53 ± 0.04 pg/mL), B-type natriuretic peptide (10.66 ± 0.44 pg/mL), aspartate aminotransferase (86.5 ± 4.99 U/L), Alanine Transaminase (55.33 ± 2.90 U/L), urea (25.33 ± 1.15 mg/dL) and creatinine (0.64 ± 0.02 mg/dL) but significantly increased (p ≤ 0.05) total antioxidant capacity (1.73 ± 0.07 mmol Trolox Equil./L), high-density lipids (40 ± 1.59 mg/dL) and potassium (3.82 ± 0.04 mmol/L) levels. ECG and histopathology confirmed the significant improvement in remodeling and the reversal of structural changes in the heart and pancreas. In conclusion, Artemisia vulgaris possesses significant left ventricular remodeling potential in course of diabetes-induced cardiomyopathy.
Sepsis remains one of the leading causes of death in burn patients who survive the initial insult of injury. Disruption of the intestinal epithelial barrier has been shown after burn injury; this can lead to the translocation of bacteria or their products (e.g., endotoxin) from the intestinal lumen to the circulation, thereby increasing the risk for sepsis in immunocompromised individuals. Since the maintenance of the epithelial barrier is largely dependent on the intestinal microbiota, we examined the diversity of the intestinal microbiome of severely burned patients and a controlled mouse model of burn injury. We show that burn injury induces a dramatic dysbiosis of the intestinal microbiome of both humans and mice and allows for similar overgrowths of Gram-negative aerobic bacteria. Furthermore, we show that the bacteria increasing in abundance have the potential to translocate to extra-intestinal sites. This study provides an insight into how the diversity of the intestinal microbiome changes after burn injury and some of the consequences these gut bacteria can have in the host.
Increase in vascular endothelial permeability is an earliest pathological hallmark in diabetes mellitus, which progressively leads to cardiovascular disease. Stromal‐interaction molecule 1 (STIM1), upon sensing the depletion of calcium (Ca 2+ ) from the endoplasmic reticulum (ER) store, organizes as a puncta that triggers store‐operated Ca 2+ entry (SOCE) via plasmalemmal Ca 2+ ‐selective Orai1 channels in endothelial cells. Thus, signals to disrupt endothelial cell‐cell junctions’ integrity and increase in endothelial permeability. Recent studies show that the anti‐diabetic drug metformin confers vascular benefits beyond glycaemia control and reduced the high risk of cardiovascular events in pre‐diabetes patients. However, the precise pharmacological role of metformin and the mechanism to regulate SOCE‐induced endothelial hyper permeability response in coronary vasculature remain enigmatic in the pathogenesis of hyperglycemia. Here, we demonstrate a previously undetermined role of metformin in inhibiting the Orai1 mediated induction of SOCE and thereby preventing the disintegration of vascular endothelial (VE) cadherin in high‐glucose exposed coronary vascular endothelial cells (ECs). Our data showed that exposing the human coronary endothelial cell monolayer to high glucose media (25mM) for 48 hours increased the expression of Orai1, protracted SOCE and the increased in endothelial permeability. We found that SOCE mediated by Orai1 activated the Pyk2 in ECs. Intriguingly, we observed the tyrosine phosphorylation of vascular endothelial‐protein tyrosine phosphatase (VE‐PTP) at tyrosine (Y) 1981 residue downstream of the Pyk2 activation in high glucose milieu. Our results showed that metformin prevented the SOCE by decreasing the expression of Orai1 and thereby abrogated the Pyk2 mediated phosphorylation of VE‐PTP in high glucose condition. Thus, led to the stabilization and maintenance of VE‐cadherin at interendothelial junctions and strengthening the barrier function. Our data identify heretofore unprecedented signaling mechanism by which metformin via inhibiting SOCE, maintains VE‐cadherin integrity and henceforth decreased high glucose induced hyper permeability response in human coronary endothelial cells. Support or Funding Information This work is supported by the Department of Pharmaceutical Sciences, Chicago State University College of Pharmacy (CSU‐COP) research funding to Mohammad Tauseef.
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