Peritoneal IL-6 Research Articles

#1980 Past peritonitis episodes are linked to decreased peritoneal Immune Cell Function and Associated with Chronic Increased Peritoneal Inflammation

Abstract Background and Aims Chronic peritoneal inflammation and infectious complications occur in a significant proportion of PD patients. A relationship between peritoneal IL-6 levels and local immunocompetence is suspected. To analyse local immunocompetence, an ex-vivo stimulation assay of PD effluent was developed. The aim of this study was to analyse peritoneal inflammation and immunocompetence in a PD cohort in relation to clinical outcomes. Method Prospectively, 245 routinely performed 4-hour PETs (143 patients, 2679 patient-months) of patients exclusively receiving 2. generation PD fluids (two-chamber, pH neutral, low amount of glucose degradation products) were analysed. An ex-vivo cell stimulation protocol of the fresh effluents was performed of all PETs. Peritoneal immune cell function was analysed using ex-vivo Toll-like receptor (LPS/Pam3Cys) stimulated IL-6 release as an index of immunocompetence. The molecular effects of effluent components and the addition of alanyl-glutamine to PD fluid were analysed in heterologous cell stimulation experiments and using an effluent proteomics and metabolomics approach. Results IL-6 in the effluent showed no association with various patient characteristics (incl. RRF, underlying disease, peritonitis episodes, time on PD). A significant association of peritoneal IL-6 with solute transport rates and systemic markers of uremic inflammation was found. IL-6 in effluent (HR 2.54) and stimulated 1 h effluent (HR 0.34) was predictive of subsequent peritonitis episodes. An inverse association was observed with ex-vivo stimulated IL-6 release from peritoneal cells (P = .02), most pronounced in patients with a history of peritonitis (P = .008). Patients with above median elevated IL-6 levels showed reduced peritoneal immune cell function. The results were validated in an independent multi-centre PD cohort (n = 48). A proteomics (n = 17) and targeted metabolomics (patients n = 134, 1004 metabolites) analysis of PD effluents show an overrepresentation of apoptosis and neutrophil degranulation pathways in patients with elevated effluent IL-6 levels and reduced response mechanisms to pathogens when compared to effluents from patients with low effluent IL-6 levels. Heterologous donor-PBMC stimulation (4 Healthy donors) with 4h PET PD-effluents of 20 patients showed reduced immunocompetence with elevated IL-6 (P = .038) and improved immunocompetence when 8 mM alanyl-glutamine were added to the PD fluid during the dwell. These results could also be validated in a post-hoc analysis of a RCT testing alanyl-glutamine addition to PD fluid for 8 weeks in PD patients. Conclusion This is the first longitudinal study to show the relationship between peritoneal inflammation and impaired immune function of peritoneal cells, possibly predisposing to infectious complications. The possible underlying mechanistic link may represent the biological correlate (“immune-paralysis”) for PD patients at increased risk for recurrent episodes of peritonitis.

Impact of Standard Versus Low Pneumoperitoneum Pressure on Peritoneal Environment in Laparoscopic Cholecystectomy. Randomized Clinical Trial.

High CO 2 pneumoperitoneum pressure during laparoscopy adversely affects the peritoneal environment. This study hypothesized that low pneumoperitoneum pressure may be linked to less peritoneal damage and possibly to better clinical outcomes. One hundred patients undergoing scheduled laparoscopic cholecystectomy were randomized 1:1 to low or to standard pneumoperitoneum pressure. Peritoneal biopsies were performed at baseline time and 1 hour after peritoneum insufflation in all patients. The primary outcome was peritoneal remodeling biomarkers and apoptotic index. Secondary outcomes included biomarker differences at the studied times and some clinical variables such as length of hospital stay, and quality and safety issues related to the procedure. Peritoneal IL6 after 1 hour of surgery was significantly higher in the standard than in the low-pressure group (4.26±1.34 vs. 3.24±1.21; P =0.001). On the contrary, levels of connective tissue growth factor and plasminogen activator inhibitor-I were higher in the low-pressure group (0.89±0.61 vs. 0.61±0.84; P =0.025, and 0.74±0.89 vs. 0.24±1.15; P =0.028, respectively). Regarding apoptotic index, similar levels were found in both groups and were 44.0±10.9 and 42.5±17.8 in low and standard pressure groups, respectively. None of the secondary outcomes showed differences between the 2 groups. Peritoneal inflammation after laparoscopic cholecystectomy is higher when surgery is performed under standard pressure. Adhesion formation seems to be less in this group. The majority of patients undergoing surgery under low pressure were operated under optimal workspace conditions, regardless of the surgeon's expertise.

Inflammatory biomarker signatures in post-surgical drain fluid may detect anastomotic leaks within 48 hours of colorectal resection

BackgroundThe optimal treatment of colorectal cancer is surgical resection and primary anastomosis. Anastomotic leak can affect up to 20% of patients and creates significant morbidity and mortality. Current diagnosis of a leak is based on clinical suspicion and subsequent radiology. Peritoneal biomarkers have shown diagnostic utility in other conditions and could be useful in providing earlier diagnosis. This pilot study was designed to assess the practical utility of peritoneal biomarkers after abdominal surgery utilising an automated immunoassay system in routine use for quantifying cytokines.MethodsPatients undergoing an anterior resection for a rectal cancer diagnosis were recruited at UniversityHospital of Wales, Cardiff between June 2019 and June 2021. A peritoneal drain was placed in the proximity of the anastomosis during surgery, and peritoneal fluid was collected at days 1 to 3 post-operatively, and analysed using the Siemens IMMULITE platform for interleukin (IL)-1β, IL-6, IL-10, CXCL8, tumour necrosis factor alpha (TNFα) and C-reactive protein (CRP).ResultsA total of 42 patients were recruited (22M:20F, median age 65). Anastomotic leak was detected in four patients and a further five patients had other intra-abdominal complications. The IMMULITE platform was able to provide robust and reliable results from the analysis of the peritoneal fluid. A metric based on the combination of peritoneal IL-6 and CRP levels was able to accurately diagnose three anastomotic leaks, whilst correctly classifying all negative control patients including those with other complications.ConclusionsThis pilot study demonstrates that a simple immune signature in surgical drain fluid could accurately diagnose an anastomotic leak at 48 h postoperatively using instrumentation that is already widely available in hospital clinical laboratories.

IL-8 and IL-12p70 are associated with pelvic pain among infertile women with endometriosis.

To evaluate interleukin (IL)-1β, IL-6, IL-8, and IL-12p70 levels in serum and peritoneal fluid in women related to infertility and pelvic pain. Eighty-seven women were diagnosed with endometriosis or cases related to infertility. IL-1β, IL-6, IL-8, and IL-12p70 levels in serum and peritoneal fluid were determined by enzyme-linked immunosorbent assay (ELISA). Pain assessment was evaluated by the Visual Analog Scale (VAS) score. Serum IL-6 and IL-12p70 levels increased in women with endometriosis compared to the control group. Serum and peritoneal IL-8 and IL-12p70 levels correlated with VAS scores in infertile women. A positive correlation was also found between peritoneal IL-1β and IL-6 with VAS score. A significant difference in peritoneal IL-1β levels was associated with menstrual pelvic pain, while peritoneal IL-8 levels were related to dyspareunia, menstrual, and post-menstrual pelvic pain in infertile women. An association of IL-8 and IL-12p70 levels were related to pain in endometriosis, as well as a relationship between cytokine expression and VAS score. Further studies should be addressed to investigate the precise mechanism of cytokine-related pain in endometriosis.

A novel gut inflammatory rat model by laparotomic injection of peptidoglycan from Staphylococcus aureus.

Inflammatory bowel disease includes ulcerative colitis and Crohn's disease, and is globally increasing. An appropriate model system is required to dissect the disease pathogenesis and drugs screening for adequate treatment. In the present study, we established a novel model of gut inflammation by injecting peptidoglycan from Staphylococcus aureus using laparotomic procedure. For this, three different doses of peptidoglycan, i.e., 2.5, 5 and 10mg/kg body weight were used. The treatment effect was evaluated by studying the macrophage phagocytic function, spleen lymphocytes' proliferation and qRT-PCR for the assessment of peritoneal cells' gene expression. In addition, histological analysis of gut sections, gastric acidity, immunoglobulins and cytokines were assessed. There was significant increase in phagocytic activity in 10mg/kg body weight PGN group. A dose dependent increase in spleen lymphocytes' proliferation and a significant increase in total acid secretion in 5 and 10mg/kg body weight PGN treated rats were observed. In addition, a significant increment in TLR-2 and CD-14 mRNA expression in peritoneal cells, TNF-α, IL-6 and IFN-γ level and maximum distortion of gut architecture was observed in 10mg/kg body weight PGN group. Hence, peptidoglycan from S. aureus can be used for establishing the screening model to study the action and mechanism of anti-inflammatory food products and drugs.

Effects of metformin, letrozole and atorvastatin on inflammation and apoptosis in experimental peritoneal and ovarian endometriosis in the rat

Endometriosis is a common gynecological hurting disorder in which tissue is similar to the tissue that normally lines the inner layer of the uterus. It often causes fertility problems. Unfortunately, effective treatments are limited. Therefore it's important to explore an imperative and easily accessible treatment to alleviate the probable pathologies and preserve fertility in endometriosis. Consequently, we aimed to investigate the effects of metformin, letrozole, and atorvastatin on inflammation and apoptosis in experimentally induced ovarian and peritoneal endometriosis in rat models. In the present study, 35 rats were randomly divided into five groups. Group 1: sham-operated control group. Group 2: untreated endometriosis group. Group 3: given 100 mg/kg/day of oral metformin. Group 4: given 0.1 mg/kg/day of oral letrozole. Group 5: given 2.5 mg/kg/day of oral atorvastatin. At the end of the 28 days, we examined Ki67, Bax and Bcl-2 immunoexpressions in ovarian and peritoneal tissues, and IL-6, IL-8, and TNF-α levels were evaluated from the peritoneal fluid. All medical treatment groups showed a significant decrease in Ki67 expression. A significant increase in Bax expression was also observed in all samples from all medical treatment groups (other than the untreated endometriosis groups). Further, a significant decrease in Bcl-2 expression was found in all medical treatment groups. IL-6, IL-8, and TNF-α levels were significantly lower in all medical treatment groups than in the endometriosis groups. In conclusion; Metformin, letrozole, and atorvastatin showed apoptosis induction and anti-inflammatory effects on both ovarian and peritoneal endometriosis in experimental models.

Peritoneal cytokines as a predictor of colorectal anastomotic leaks on postoperative day 1: a systematic review and meta-analysis

Anastomotic leakage (AL) is a major complication of colorectal surgery resulting in morbidity, mortality and poorer quality of life. The early diagnosis of AL is challenging due to the poor positive predictive value of tests available and reliance on clinical presentation which may be delayed. The aim of this systematic review was to assess the applicability of peritoneal cytokine levels as an early predictive test of AL in postoperative colorectal cancer patients. A comprehensive literature search was performed from inception to January 2021, in MEDLINE and EMBASE databases using MeSH and non-MeSH terms in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All studies evaluating peritoneal cytokines in the context of AL were included in this review. Two hundred ninety-two abstracts were screened, 30 full manuscripts evaluated, and 12 prospective studies were included. There were 8 peritoneal cytokines evaluated (interleukin [IL]-1β, IL-6, IL-8, IL-10, vascular endothelial growth factor [VEGF], tumour necrosis factor alpha [TNF alpha] and matrix metalloproteinase [MMP]2 and MMP9) between AL and non-AL groups on postoperative day 1. Those that included IL-6 (7 studies), IL-10 (4 studies), TNF alpha (6 studies) and MMP9 (2 studies) were included in the meta-analysis. IL-10 was the only cytokine in the meta-analysis that was significantly (p < 0.05) raised in drain fluid on postoperative day 1 in AL patients. Peritoneal IL-10 was significantly raised on postoperative day 1 in patients who subsequently developed AL. This may be a useful early predictor of AL and aid in an earlier diagnosis for postoperative colorectal patients. The range of cytokines investigated within the literature is limited and from heterogeneous studies which suggests more research is needed.

MO710GALECTIN-3, IS IT A NEW PLAYER IN PERITONEAL INFLAMMATION AMONG PATIENTS UNDERGOING PERITONEAL DIALYSIS?

Abstract Background and Aims Peritoneal dialysis (PD) is a common used method for renal replacement therapy. Prolonged PD treatment causes structural and functional changes in the peritoneal membrane which are attributed to local inflammatory process in the peritoneal cavity. Galectin-3 (Gal-3) is a galactoside-binding lectin with pro-inflammatory and pro-fibrotic effects. The aim of this study was to assess correlation between Gal-3 serum and dialysate effluent levels with peritoneal membrane transport characteristics. Method Gal-3 levels in serum and dialysate effluent were measured simultaneously in prevalent PD patients in morning visit or during peritoneal equilibration test (PET). Gal-3 levels were correlated with clinical and laboratory parameters. Interlukin (IL) -6 levels were measured in dialysate effluent. Gal-3 mRNA and protein expression were evaluated after exposure of primary endothelial cell culture to several dialysate solutions. Results 37 PD patients were included in the study; mean age was 65.7±13.1 years, mean dialysis vintage was 17.5±13 months. Gal-3 levels in dialysate effluent correlated with peritoneal equilibration test (PET) results (0.663, p=0.005) and effluent IL-6 levels (0.674, p=0.002) but not with serum Gal-3 levels or dialysis vintage. Patients with high PET results had higher effluent Gal-3 levels as compared average low PET results. In multivariate regression analysis effluent IL-6 level was the most dominant predictor of effluent Gal-3 levels. Gal-3 mRNA and protein expression in primary endothelial cell culture were not affected by stimulation with dialysate solutions. Conclusion Our study demonstrated presence of Gal-3 within the dialysate effluent in PD patients. Gal-3 levels correlated with peritoneal membrane transport characteristics and effluent IL-6 levels suggesting a role in the inflammatory process within the peritoneal cavity.

Interleukin 10 level in the peritoneal cavity is a prognostic marker for peritoneal recurrence of T4 colorectal cancer

Peritoneal recurrence (PR) is a major relapse pattern of colorectal cancer (CRC). We investigated whether peritoneal immune cytokines can predict PR. Cytokine concentrations of peritoneal fluid from CRC patients were measured. Patients were grouped according to peritoneal cancer burden (PCB): no tumor cells (≤ pT3), microscopic tumor cells (pT4), or gross tumors (M1c). Cytokine concentrations were compared among the three groups and the associations of those in pT4 patients with and without postoperative PR were assessed. Of the ten cytokines assayed, IL6, IL10, and TGFB1 increased with progression of PCB. Among these, IL10 was a marker of PR in pT4 (N = 61) patients based on ROC curve (p = 0.004). The IL10 cut-off value (14 pg/mL) divided patients into groups with a low (7%, 2 of 29 patients) or high (45%, 16 of 32 patients) 5-year PR (p < 0.001). Multivariable analysis identified high IL10 levels as the independent risk factor for PR. Separation of patients into training and test sets to evaluate the performance of IL10 cut-off model validated this cytokine as a risk factor for PR. Peritoneal IL10 is a prognostic marker of PR in pT4 CRC. Further research is necessary to identify immune response of intraperitoneal CRC growth.

Albumin-Based LL37 Peptide Nanoparticles as a Sustained Release System against Pseudomonas aeruginosa Lung Infection.

Pseudomonas aeruginosa (PA) has emerged as a pressing challenge to pulmonary infection and lung damage. The LL37 peptide is an efficient antimicrobial agent against PA strains, but its application is limited because of fast clearance in vivo, biosafety concerns, and low bioavailability. Thus, an albumin-based nanodrug delivery system with reduction sensitivity was developed by forming intermolecular disulfide bonds to increase in vivo LL37 performance against PA. Cationic LL37 can be efficiently encapsulated via electrostatic interactions to exert improved antimicrobial effects. The LL37 peptide exhibits greater than 48 h of sustained released from LL37 peptide nanoparticles (LL37 PNP), and prolonged antimicrobial effects were noted as the incubation time increased. Levels of inflammatory cytokines secreted by peritoneal macrophages, including TNF-α and IL-6, were reduced significantly after LL37 PNP treatment following PA stimulation, indicating that LL37 PNP inhibits PA growth and exerts anti-inflammatory effects in vitro. In a murine model of acute PA lung infection, LL37 PNP significantly reduced TNF-α and IL-1β expression and alleviated lung damage. The accelerated clearance of PA indicates that LL37 PNP could improve PA lung infection and the subsequent inflammation response more efficiently compared with free LL37 peptide. In conclusion, this excellent biocompatible LL37 delivery strategy may serve as an alternative approach for the application of new types of clinical treatment in future.

Cytokines in abdominal exudate and serum predict small bowel obstruction following appendectomy.

This study aimed to investigate the value of inflammatory markers for the prediction of small bowel obstruction (SBO) following appendectomy. We included cases of acute appendicitis that underwent laparoscopic appendectomy (LA) in the Qingdao Municipal Hospital between January 2017 and January 2019. The cases were divided into an SBO group and a non-SBO group depending on whether patients had or did not have SBO, and patients were followed up for at least 1 year. The levels of interleukin (IL)-1β, IL-6 and tumour necrosis factor-alpha (TNF-α) in abdominal exudate and venous blood were examined using enzyme-linked immunosorbent assay. After 1 year of follow-up, there were 985 cases in the non-SBO group and 16 cases in the SBO group. The levels of IL-1β, IL-6 and TNF-α in abdominal exudate on post-operative day 1 in the SBO group were 172.5 ± 14.7, 2167.3 ± 372.1 and 253.9 ± 12.9 pg/mL, respectively, which were significantly higher than that in the non-SBO group. The serum levels of IL-1β, IL-6, TNF-α and C-reactive protein (CRP) in the SBO group were significantly higher than that in the non-SBO group before surgery. Post-operatively, the inflammatory markers above decreased significantly and became similar with time in both groups. The logistic regression showed that the levels of peritoneal IL-6, preoperative serum CRP and perforated appendicitis were significant risk factors of SBO. The specificity and sensitivity of peritoneal IL-6 were 0.81 and 0.921, respectively. The IL-1β, IL-6, TNF-α and CRP in serum and abdominal exudate played an important role in SBO after LA. The peritoneal IL-6 was the most reliable prediction marker for SBO.

Exercise Preconditioning-Induced Modification of Gut Microbiota Increases Survival in Cecal Ligation and Perforation (CLP)-Induced Sepsis

PURPOSE: To investigate whether exercise preconditioning-induced modification of gut microbiota increases survival in cecal ligation and puncture (CLP)-induced sepsis. METHODS: C57BL/6N male mice at age of 4 weeks were randomly assigned to either control (n=10) or exercise preconditioning (n=10). Mice in the exercise group were subjected to an 8-week-high-intensity treadmill running. Prior to sepsis, the effect of exercise preconditioning on gut microbiota was explored by 16S ribosomal RNA amplification sequencing. Survival probability, organ damage, and pro- and anti-inflammatory cytokines were assessed to investigate whether or not exercise preconditioning-induced changes in gut microbiota modulate host response to CLP-induced sepsis. RESULTS: Along with increased β diversity, exercise preconditioning induced the modification of gut microbiota at species level dominated by the phyla Bacteriodetes, Firmicutes, and Verrucomicrobia and to a less extent by the phylum Cyanobacteria. Preconditioned mice had higher survival (p<0.05) and less organ damage in sepsis compared to control mice. At 8-hr post-sepsis, the preconditioned mice had lower peritoneal interleukin (IL)-1β (p=0.020) and IL-6 (p<0.001) but higher peritoneal interferon (IFN)-γ (p=0.002), IL-10 (p<0.001), and transforming growth factor (TGF)-1β (p<0.001) compared to the control mice. In addition, the preconditioned mice has lower blood growth-regulated oncogene (GRO)-α (p=0.001), monocyte chemoattractant protein (MCP)-1 (p<0.001), macrophage inflammatory protein (MIP) 2 (p<0.001), and tumor necrosis factor (TNF)-α (p=0.003) compared to the control mice. At 20-hr post-sepsis, the preconditioned mice had lower peritoneal IL-1β (p<0.001) and Il-6 (p<0.001) but higher peritoneal TGF-1β (p<0.001) in conjunction with higher blood IL-17A (p=0.002) and TGF-1β (p=0.029) compared to the control mice. CONCLUSIONS: The current findings suggested that exercise preconditioning-induced modification of gut microbiota might contribute to increased survival in sepsis by modulating host response toward the establishment of a balance between pro- and anti-inflammation. Supported by the National Research Foundation funded by the Korean Government (NRF-2018R1D1A1B07048153 and NRF-2016R1A6A3A11932432).

Amitriptyline Reduces Inflammation and Mortality in a Murine Model of Sepsis.

During sepsis, an unchecked pro-inflammatory response can be detrimental to the host. We investigated the potential protective effect of amitriptyline (AT). We used two murine models of sepsis: Cecal ligation and puncture and endotoxemia following LPS challenge. Aural temperatures were taken and cytokines quantified by cytometric bead assay. Lung injury was determined histologically and by protein determination in bronchoalveolar lavage fluid. Cell accumulation in the peritoneum was analyzed by flow cytometry, as well as cytokine production and p38-phosphorylation. Neutrophil chemotaxis was evaluated using an in vitro transwell assay. Our findings demonstrate that AT-treated septic mice have improved survival and are protected from pulmonary edema. Treatment with AT significantly decreased serum levels of KC and monocyte chemoattractant protein-1, as well as the accumulation of neutrophils and monocytes in the peritoneum of septic mice. Peritoneal IL-10 levels in septic mice were increased upon AT treatment. Direct treatment of septic mice with IL-10 recapitulated the effects of AT. Endotoxemic mice also exhibited enhanced IL-10 production upon AT-administration and peritoneal macrophages were identified as the ATinfluenced producers of IL-10. Treatment of these cells with AT in vitro resulted in increased p38-phosphorylation and IL-10 generation, whereas ceramide and p38 inhibition had the opposite effect. Altogether, AT treatment improved survival, increased IL-10 levels, and mitigated a pro-inflammatory response during sepsis. We conclude that AT is a promising therapeutic to temper inflammation during septic shock.

Evaluation of the effects of Iranian propolis on the severity of post operational-induced peritoneal adhesion in rats

BackgroundPeritoneal adhesion is a major complication of surgery that can lead to serious problems such as bowel obstruction, pain, infertility and even mortality. Propolis is a honey bee product with anti-inflammatory and anti-oxidant activities that could potentially protect against adhesive surgical complications. MethodsForty 8-weeks-old rats (275 ± 25 g) were divided into five groups: normal group without any surgical procedure, and experimental groups treated with normal saline, 50 mg/kg, 100 mg/kg and 200 mg/kg of propolis. Peritoneal adhesions were examined macroscopically and also, the levels of inflammatory factors (IL-6, IL-1β and TNF-α), growth factors (TGF-β1 and VEGF) were evaluated in the study groups using ELISA. Biochemical indices of oxidative status including Nitric Oxide (NO), Malondialdehyde (MDA) and Glutathione (GSH) were also measured. ResultsPeritoneal adhesion scores, IL-1β, IL-6, TNF-α, TGF-β1, VEGF, NO, GSH and MDA levels were significantly different between the study groups (p < 0.001). Propolis treatment reduced peritoneal adhesion (p < 0.001), TNF-α (p < 0.001), IL-1β (p < 0.001), IL-6 (p < 0.001), TGF-β1 (p < 0.001), VEGF (p < 0.001), NO (p < 0.001) and MDA (p < 0.001), while GSH levels were increased (p < 0.001) compared with the vehicle group. Our results showed that higher dose of propolis was associated with significantly greater reductions in peritoneal adhesion (p < 0.001), TNF-α (p < 0.001), IL-1β (p < 0.001), IL-6 (p < 0.001), VEGF (p < 0.001), NO (p < 0.001) and MDA (p < 0.001), a greater increase in GSH levels (p < 0.001) compared with the lower dose. ConclusionsPropolis treatment can dose-dependently reduce peritoneal adhesion through its anti-inflammatory, anti-angiogenic and antioxidant properties. Therefore, propolis might serve as a protective agent against post-surgical adhesive complications.

Co-encapsulation and co-transplantation of mesenchymal stem cells reduces pericapsular fibrosis and improves encapsulated islet survival and function when allografted

Pericapsular fibrotic overgrowth (PFO) is associated with poor survival of encapsulated islets. A strategy to combat PFO is the use of mesenchymal stem cells (MSC). MSC have anti-inflammatory properties and their potential can be enhanced by stimulation with proinflammatory cytokines. This study investigated whether co-encapsulation or co-transplantation of MSC with encapsulated islets would reduce PFO and improve graft survival. Stimulating MSC with a cytokine cocktail of IFN-γ and TNF-α enhanced their immunosuppressive potential by increasing nitric oxide production and secreting higher levels of immunomodulatory cytokines. In vitro, co-encapsulation with MSC did not affect islet viability but significantly enhanced glucose-induced insulin secretion. In vivo, normoglycemia was achieved in 100% mice receiving islets co-encapsulated with stimulated MSC as opposed to 71.4% receiving unstimulated MSC and only 9.1% receiving encapsulated islets alone. Microcapsules retrieved from both unstimulated and stimulated MSC groups had significantly less PFO with improved islet viability and function compared to encapsulated islets alone. Levels of peritoneal immunomodulatory cytokines IL-4, IL-6, IL-10 and G-CSF were significantly higher in MSC co-encapsulated groups. Similar results were obtained when encapsulated islets and MSC were co-transplanted. In summary, co-encapsulation or co-transplantation of MSC with encapsulated islets reduced PFO and improved the functional outcome of allotransplants.

Comparison of honey and dextrose solution on post-operative peritoneal adhesion in rat model

BackgroundPeritoneal adhesion between abdominal organs is a complication of surgery. It causes major complications like pain, bowel obstruction, infertility and increases risk of death. Honey is known to have anti-inflammatory and antioxidant properties potentially relevant for adhesive protection. MethodsThirty rats were divided into five groups: negative control without any surgical procedure (normal group), control group treated with normal saline, experimental group I treated with 1ml of 10% honey, experimental group II treated with honey at half concentration of group I (honey0.5), and positive control group receiving 1ml of dextrose 5%. Inflammatory, growth and angiogenesis factors (TNF-α, Il-6, IL-1β, TGF-β1 and VEGF) of the adhesion tissue were assessed using ELISA. Antioxidant factors (NO, GSH and MDA) were also assessed using biochemical procedures. ResultsThe difference between peritoneal adhesion scores, TNF-α, IL-1β, IL-6, TGF-β1, VEGF, NO, GSH and MDA value of all groups was strongly significant (p<0.001). We showed that honey can decrease peritoneal adhesion (p<0.001), TNF-α (p<0.001), IL-1β (p<0.001), IL-6 (p<0.001), TGF-β1 (p<0.001), VEGF (p<0.001), NO (p<0.001), MDA (p<0.001) and increase GSH (p<0.001) compared with control group. Honey 0.5 also significantly decreased peritoneal adhesion (p<0.001), TNF-α (p<0.001), IL-1β (p<0.01), IL-6 (p<0.001), VEGF (p<0.001), NO (p<0.001), MDA (p<0.01) and increase GSH (p<0.001) compared with control group. ConclusionsWe find that honey can decrease inflammatory, growth and angiogenesis factors which can advance peritoneal adhesion and increase antioxidant factors. Honey could serve as a protective agent for peritoneal adhesion.

Δ9-tetrahydrocannabinol (THC) activation of cannabinoid receptors induces unique changes in the murine gut microbiome and associated induction of myeloid-derived suppressor cells and Th17 cells.

Abstract Δ9-tetrahydrocannabinol (THC) is a partial agonist for cannabinoid receptors (CB1 &amp; CB2), is the main psychoactive ingredient found in the Cannabis plant, and can modulate the nervous and immune system. Our intestine harbors a diverse array of bacteria, referred to as the microbiome, which is known to impact many bodily functions, including the immune system. In the current study, we investigated the effect of THC on the gut microbiome and the naïve immune response. We tested the effect of acute or chronic exposure of C57BL/6 mice to THC on the immune system, and correlated said changes with a flux in intestinal bacteria. Intraperitoneal exposure to THC resulted in migration of CD11b+Gr-1+ myeloid-derived suppressor cells (MDSCs) from the bone marrow to the peritoneal cavity. These MDSCs remained in the peritoneum throughout chronic THC administration, where they proliferated and produced IL-6. The peritoneal IL-6 led to an increase in T helper 17 (Th17) cells in the mesenteric lymph node (mLN), as well as increases of IL-17A in the serum and mLN supernatant of THC-treated mice. Indeed, an adoptive transfer of THC MDSCs increased the number of Th17 cells compared to bone marrow (BM) MDSCS, and in-vitro polarization experiments revealed THC MDSCs to be more potent inducers of Th17 cells than BM MDSCs. The alterations in the gut immune cells occurred in tandem with an increase in the number of Alphaproteobacteria in the cecum and feces of mice treated with THC compared to vehicle and naïve mice, and this effect was replicated after an adoptive transfer of THC MDSCS, but not BM MDSCs. Together, these data demonstrated that marijuana use can alter the gut microbiota as well as cause significant changes in the naïve immune system.

Regulation of the NLRP3 inflammasome in Porphyromonas gingivalis-accelerated periodontal disease.

Porphyromonas gingivalis is involved in the pathogenesis of chronic inflammatory periodontal disease. Recent studies have suggested that the NLRP3 inflammasome plays an important role in the development of chronic inflammation. We investigated a possible association between the inflammasome in gingival inflammation and bone loss induced by P. gingivalis infection using NLRP3-deficient mice. Wild-type and NLRP3-deficient mice were injected orally with P. gingivalis. We assessed alveolar bone loss, expression of pro-interleukin (IL)-1β, pro-IL-18, receptor activator of nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG) in gingival tissue, as well as IL-1β, IL-18, and IL-6 production and caspase-1 activity in peritoneal macrophages. Porphyromonas gingivalis challenge significantly increased alveolar bone loss; gingival gene expression of pro-IL-1β, pro-IL-18, and RANKL; production of IL-1β, IL-18, and IL-6; and caspase-1 activity in peritoneal macrophages of wild-type mice, but did not affect NLRP3-deficient mice. Meanwhile, OPG mRNA expression in gingival tissue and peritoneal IL-6 production were significantly higher in NLRP3-knockout mice. Porphyromonas gingivalis activated innate immune cells via the NLRP3 inflammasome. These results suggest that the NLRP3 inflammasome, followed by a response from the IL-1 family, is critical in periodontal disease induced by wild-type P. gingivalis challenge via sustained inflammation.

Lipoxin A4 protects against lipopolysaccharide-induced sepsis by promoting innate response activator B cells generation

Sepsis is a serious disease that leads to severe inflammation, dysregulation of immune system, multi-organ failure and death. Innate response activator (IRA) B cells, which produce granulocyte-macrophage colony-stimulating factor (GM-CSF), protect against microbial sepsis. Lipid mediator lipoxin A4 (LXA4) exerts anti-inflammatory and immunoregulatory effects, and it has been reported that LXA4 receptor ALX/FPR2 is expressed on B cells. Here, we investigated the potential role of LXA4 on IRA B cells in lipopolysaccharide (LPS)-induced sepsis. We found that LXA4 significantly promoted the expansion of splenic IRA B cells and increased GM-CSF expression in splenic B cells with LPS stimulation. After splenectomy, LXA4 treatment did not change the serum or peritoneal IL-1β, IL-6 and TNF-α levels in LPS-induced sepsis. LXA4 accelerated the migration of peritoneal B cells to spleen for their differentiation into IRA B cells, whereas this effect was independent of peritoneal macrophage. Furthermore, LXA4 enhanced the phosphorylation level of signal transducer and activator of transcription 5 (STAT5) in splenic B cells. These results suggest that LXA4 protects against LPS-induced sepsis by promoting the generation and migration of splenic IRA B cells, and the underlying molecular mechanism may be related to STAT5 activation. It might provide new insights and therapeutic approaches for treating sepsis.

Myeloid Cell Prostaglandin E2 Receptor EP4 Modulates Cytokine Production but Not Atherogenesis in a Mouse Model of Type 1 Diabetes.

Type 1 diabetes mellitus (T1DM) is associated with cardiovascular complications induced by atherosclerosis. Prostaglandin E2 (PGE2) is often raised in states of inflammation, including diabetes, and regulates inflammatory processes. In myeloid cells, a key cell type in atherosclerosis, PGE2 acts predominately through its Prostaglandin E Receptor 4 (EP4; Ptger4) to modulate inflammation. The effect of PGE2-mediated EP4 signaling specifically in myeloid cells on atherosclerosis in the presence and absence of diabetes is unknown. Because diabetes promotes atherosclerosis through increased arterial myeloid cell accumulation, we generated a myeloid cell-targeted EP4-deficient mouse model (EP4M-/-) of T1DM-accelerated atherogenesis to investigate the relationship between myeloid cell EP4, inflammatory phenotypes of myeloid cells, and atherogenesis. Diabetic mice exhibited elevated plasma PGE metabolite levels and elevated Ptger4 mRNA in macrophages, as compared with non-diabetic littermates. PGE2 increased Il6, Il1b, Il23 and Ccr7 mRNA while reducing Tnfa mRNA through EP4 in isolated myeloid cells. Consistently, the stimulatory effect of diabetes on peritoneal macrophage Il6 was mediated by PGE2-EP4, while PGE2-EP4 suppressed the effect of diabetes on Tnfa in these cells. In addition, diabetes exerted effects independent of myeloid cell EP4, including a reduction in macrophage Ccr7 levels and increased early atherogenesis characterized by relative lesional macrophage accumulation. These studies suggest that this mouse model of T1DM is associated with increased myeloid cell PGE2-EP4 signaling, which is required for the stimulatory effect of diabetes on IL-6, markedly blunts the effect of diabetes on TNF-α and does not modulate diabetes-accelerated atherogenesis.