Restoration of the Mucosal IgA Response by Improving CD4+ T Pyroptosis Fails to Attenuate Gut Bacterial Translocation and Organ Damage After LPS Attack.

BACKGROUND: Currently, the mechanisms of impaired gut mucosal immunity in sepsis remain unclear. Gut immunoglobulin A (IgA) is an important defense mechanism against invasive pathogens, and CD4+ T cells regulate the IgA response. AIM: We aimed to verify the hypothesis indicating that CD4+ T pyroptosis induced by lipopolysaccharide (LPS) leads to an impaired gut IgA response and subsequent bacterial translocation and organ damage. METHODS: Cultured CD4+ T cells and mice were manipulated with LPS, and pyroptosis was improved by A438079 or adoptive CD4+ T cell transfer. The changes demonstrated in pyroptosis-related molecules, cytotoxicity and CD4+ T cells were examined to determine CD4+ T pyroptosis. The changes demonstrated in IgA+ B cells, AID (key enzyme for immunoglobulins) and IgA production and function were examined to evaluate the IgA response. Serum biomarkers, bacterial colonies and survival analysis were detected for bacterial translocation and organ damage. RESULTS: LPS attack induced CD4+ T pyroptosis, as evidenced by increased expression of P2X7, Caspase-11 and cleaved GSDMD, which elevated cytotoxicity and decreased CD4+ T cells. Decreased CD4+ T subsets (Foxp3+ T and Tfh cells) influenced the IgA response, as evidenced by lower AID expression, which decreased IgA+ B cells and IgA production and function. A438079 or cell transfer improved the IgA response but failed to reduce the translocation of gut pathogens, damage to the liver and kidney, and mortality of mice. CONCLUSION: LPS attack results in CD4+ T pyroptosis. Improvement of pyroptosis restores the mucosal IgA response but fails to ameliorate bacterial translocation and organ damage.

Lipidomics Study of Sepsis-Induced Liver and Lung Injury under Anti-HMGB1 Intervention.

Sepsis usually leads to lethal multiorgan dysfunction including acute liver failure (ALF) and acute lung injury (ALI). This research sought to reveal the lipid alteration of anti-high mobility group box 1 (HMGB1) treatment in sepsis-induced ALF and ALI by lipidomics. The cecal ligation and puncture-induced mouse model was established and the anti-HMGB1 neutralizing antibody was administrated. The histopathological characteristics and inflammatory factors were determined to assess the efficacy of the antibody. Utraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used to determine lipid metabolism profiles in the liver and lung. The underlying biomarkers were identified through multivariate statistical analysis and correlation analysis with traditional physiological indicators. The pathological and biochemical results demonstrated that anti-HMGB1 neutralizing antibodies mitigated ALF and ALI in mice. Three differential metabolites in the liver and six various metabolites in the lung were significantly reversed by anti-HMGB1 treatment, mainly involved in arachidonic acid metabolism, glycerophospholipid metabolism, and sphingolipid metabolism. Additionally, we investigated several traditional signaling pathways associated with HMGB1. However, the correlation between these traditional pathways and anti-HMGB1 intervention was not significant in the current study. In conclusion, our finding provided some scientific basis for targeting HMGB1 in sepsis-induced liver and lung injury. Mass spectrometry data with identifier no. MTBLS6466 have been uploaded to MetaboLights (http://www.ebi.ac.uk/metabolights/login).

Andrographolide improves the dysfunction of endothelial progenitor cells from angiotensin II-induced hypertensive mice through SIRT1 signaling.

Endothelial progenitor cells (EPCs) are crucial for the maintenance of vascular homeostasis. The dysfunction of EPCs contributes to the endothelial damage in hypertension. Andrographolide (AGP) is a traditional Chinese patent medicine that has been reported to have protective effects on cardiovascular system. However, the effect of AGP on the function of EPCs in hypertension remains unknown. In this study, we aimed to elucidate the effect of AGP on EPCs and the underlying mechanisms. In vivo, the blood pressure and endothelial function (indicated by endothelial dependent vasodilation) of AGP-fed angiotensin II (Ang II)-infused hypertensive mice were examined. In vitro, the function of EPCs isolated from bone marrow were evaluated by tube formation, migration, and adhesion assay. Additionally, a silent information regulator 1 (SIRT1) inhibitor/agonist and a small interfering RNA (si-RNA) targeting SIRT1 were used to determine the pathway involved. The results showed that AGP not only reduced blood pressure, improved endothelial function in hypertensive mice but also restored the dysfunction of EPCs of hypertension in vitro. Mechanistically, AGP up-regulated SIRT1 expression, decreased the Bax/Bcl-2 ratio and the expression level of Cleaved caspase-3, thus inhibiting the apoptosis of Ang II induced EPCs. However, the beneficial effects of AGP on EPCs disappeared after the inhibition or the knockdown of SIRT1. To summarize, this study demonstrates for the first time that AGP improves the dysfunction of EPCs through SIRT1-mediated anti-apoptotic effects. Our findings might provide a novel therapeutic strategy for treating vascular damage in hypertension.

Dexmedetomidine Alleviates Gut-Vascular Barrier Damage and Distant Hepatic Injury Following Intestinal Ischemia/Reperfusion Injury in Mice.

BACKGROUND: Intestinal ischemia/reperfusion (I/R) challenge often results in gut barrier dysfunction and induces distant organ injury. Dexmedetomidine has been shown to protect intestinal epithelial barrier against I/R attack. The present study aims to investigate the degree to which intestinal I/R attack will contribute to gut-vascular barrier (GVB) damage, and to examine the ability of dexmedetomidine to minimize GVB and liver injuries in mice. METHODS: In vivo, intestinal ischemic challenge was induced in mice by clamping the superior mesenteric artery for 45 minutes. After clamping, the mice were subjected to reperfusion for either 2, 4, 6, or 12 hours. Intraperitoneal injection of dexmedetomidine 15, 20, or 25 µg·kg-1 was performed intermittently at the phase of reperfusion. For the in vitro experiments, the challenge of oxygen-glucose deprivation/reoxygenation (OGD/R) was established in cultured vascular endothelial cells, and dexmedetomidine (1 nM) was used to treat the cells for 24 hours. Moreover, in vivo and in vitro, SKL2001 (a specific agonist of ß-catenin) or XAV939 (a specific inhibitor of ß-catenin) was applied to determine the role of ß-catenin in the impacts provided by dexmedetomidine. RESULTS: The attack of intestinal I/R induced GVB damage. The greatest level of damage was observed at 4 hours after intestinal reperfusion. There was a significant increase in plasmalemma vesicle-associated protein-1 (PV1, a specific biomarker for endothelial permeability) expression (5.477 ± 0.718 vs 1.000 ± 0.149; P < .001), and increased translocation of intestinal macromolecules and bacteria to blood and liver tissues was detected (all P < .001). Liver damages were observed. There were significant increases in histopathological scores, serum parameters, and inflammatory factors (all P < .001). Dexmedetomidine 20 µg·kg-1 reduced PV1 expression (0.466 ± 0.072 vs 1.000 ± 0.098; P < .001) and subsequent liver damages (all P < .01). In vitro, dexmedetomidine significantly improved vascular endothelial cell survival (79.387 ± 6.447% vs 50.535 ± 1.766%; P < .001) and increased the productions of tight junction protein and adherent junction protein (all P < .01) following OGD/R. Importantly, in cultured cells and in mice, ß-catenin expression significantly decreased (both P < .001) following challenge. Dexmedetomidine or SKL2001 upregulated ß-catenin expression and produced protective effects (all P < .01). However, XAV939 completely eliminated the protective effects of dexmedetomidine on GVB (all P < .001). CONCLUSIONS: The disruption of GVB occurred following intestinal I/R. Dexmedetomidine alleviated I/R-induced GVB impairment and subsequent liver damage.

Activation of PD-1 Protects Intestinal Immune Defense Through IL-10/miR-155 Pathway After Intestinal Ischemia Reperfusion.

BACKGROUND: To date, mechanisms of intestinal immunoglobulin (Ig) dysfunction following intestinal ischemia/reperfusion (I/R) remain unclear. Programmed death 1 (PD-1) is associated with immune responses of lymphocytes. AIM: We aimed to verify the hypothesis that activation of PD-1 may improve intestinal immune dysfunction by regulating IL-10/miR-155 production after intestinal IR injury. METHODS: Intestinal I/R injury was induced in mice by clamping the superior mesenteric artery for 1 h followed by 2-h reperfusion. PD-L1 fusion Ig, anti-interleukin (IL)-10 monoclonal antibody (mAb), and microRNA (miR)-155 agomir were administered. PD-1 expression, IL-10 mRNA, and protein expression in Peyer's patches (PP) CD4+ cells were measured. MiR-155 levels, tumor necrosis factor (TNF)-α and IL-1ß concentration, and activation-induced cytidine deaminase (AID), a key enzyme for intestinal immune antibodies, in PP tissues were measured, respectively. Importantly, the production and cecal bacteria-binding capacity of IgA and IgM were detected. RESULTS: Intestinal I/R led to decreased PD-1 expression, imbalanced production, and impaired bacteria-binding capacity of IgA and IgM. Activating PD-1 by PD-L1 Ig facilitated IL-10 synthesis, then decreased miR-155 levels, and subsequently promoted AID expression and reduced TNF-α, IL-1ß concentration. Upregulation of AID improved the disruptions of intestinal immune barrier caused by IgA and IgM dysfunction. Anti-IL-10 mAb and miR-155 agomir abolished the protective effects of PD-L1 Ig on the intestinal immune defense. CONCLUSION: Activation of PD-1 with PD-L1 Ig relieves intestinal immune defensive injury through IL-10/miR-155 pathway following intestinal I/R attack. PD-1, IL-10, and miR-155 may be potential targets for the damages of intestinal barrier and immunity.

Propofol Does Not Reduce Pyroptosis of Enterocytes and Intestinal Epithelial Injury After Lipopolysaccharide Challenge.

BACKGROUND: To date, mechanisms of sepsis-induced intestinal epithelial injury are not well known. P2X7 receptor (P2X7R) regulates pyroptosis of lymphocytes, and propofol is usually used for sedation in septic patients. AIMS: We aimed to determine the occurrence of enterocyte pyroptosis mediated by P2X7R and to explore the effects of propofol on pyroptosis and intestinal epithelial injury after lipopolysaccharide (LPS) challenge. METHODS: A novel regimen of LPS challenge was applied in vitro and in vivo. Inhibitors of P2X7R (A438079) and NLRP3 inflammasome (MCC950), and different doses of propofol were administered. The caspase-1 expression, caspase-3 expression, caspase-11 expression, P2X7R expression and NLRP3 expression, extracellular ATP concentration and YO-PRO-1 uptake, and cytotoxicity and HMGB1 concentration were detected to evaluate enterocyte pyroptosis in cultured cells and intestinal epithelial tissues. Chiu's score, diamine oxidase and villus length were used to evaluate intestinal epithelial injury. Moreover, survival analysis was performed. RESULTS: LPS challenge activated caspase-11 expression and P2X7R expression, enhanced ATP concentration and YO-PRO-1 uptake, and led to increased cytotoxicity and HMGB1 concentration. Subsequently, LPS resulted in intestinal epithelial damage, as evidenced by increased levels of Chiu's score and diamine oxidase, and shorter villus length and high mortality of animals. A438079, but not MCC950, significantly relieved LPS-induced enterocyte pyroptosis and intestinal epithelial injury. Importantly, propofol did not confer the protective effects on enterocyte pyroptosis and intestinal epithelia although it markedly decreased P2X7R expression. CONCLUSION: LPS attack leads to activation of caspase-11/P2X7R and pyroptosis of enterocytes. Propofol does not reduce LPS-induced pyroptosis and intestinal epithelial injury, although it inhibits P2X7R upregulation.

TGF-ß1 improves mucosal IgA dysfunction and dysbiosis following intestinal ischaemia-reperfusion in mice.

Intestinal ischaemia/reperfusion (I/R) severely disrupts gut barriers and leads to high mortality in the critical care setting. Transforming growth factor (TGF)-ß1 plays a pivotal role in intestinal cellular and immune regulation. However, the effects of TGF-ß1 on intestinal I/R injury remain unclear. Thus, we aimed to investigate the effects of TGF-ß1 on gut barriers after intestinal I/R and the molecular mechanisms. Intestinal I/R model was produced in mice by clamping the superior mesenteric artery for 1 hr followed by reperfusion. Recombinant TGF-ß1 was intravenously infused at 15 min. before ischaemia. The results showed that within 2 hrs after reperfusion, intestinal I/R disturbed intestinal immunoglobulin A class switch recombination (IgA CSR), the key process of mucosal IgA synthesis, and resulted in IgA dysfunction, as evidenced by decreased production and bacteria-binding capacity of IgA. Meanwhile, the disruptions of intestinal microflora and mucosal structure were exhibited. Transforming growth factor-ß1 activated IgA CSR as evidenced by the increased activation molecules and IgA precursors. Strikingly, TGF-ß1 improved intestinal mucosal IgA dysfunction, dysbiosis and epithelial damage at the early stage after reperfusion. In addition, SB-431542, a specific inhibitor of activating mothers against decapentaplegic homologue (SMAD) 2/3, totally blocked the inductive effect of TGF-ß1 on IgA CSR and almost abrogated the above protective effects on intestinal barriers. Taken together, our study demonstrates that TGF-ß1 protects intestinal mucosal IgA immunity, microbiota and epithelial integrity against I/R injury mainly through TGF-ß receptor 1/SMAD 2/3 pathway. Induction of IgA CSR may be involved in the protection conferred by TGF-ß1.

Decreased PD-1/PD-L1 Expression Is Associated with the Reduction in Mucosal Immunoglobulin A in Mice with Intestinal Ischemia Reperfusion.

BACKGROUND: Intestinal ischemia/reperfusion (I/R) disrupts intestinal mucosal integrity and immunoglobulin A (IgA) generation. It has recently been shown that the programmed cell death-1 receptor (PD-1) plays a crucial role in regulating intestinal secreted IgA (sIgA). AIMS: To evaluate changes in PD-1 and PD-ligand 1 (PD-L1) expression on Peyer's patches (PP) CD4(+) T cells and to investigate the correlation between PD-1/PD-L1 and intestinal IgA production/mucosal integrity in mice following intestinal I/R. METHODS: I/R injury was induced by clamping the superior mesenteric artery for 1 h followed by 2-h reperfusion. PD-1/PD-L1 expression on PP CD4(+) T cells was measured in I/R and sham-operated mice. Additionally, transforming growth factor-ß1 (TGF-ß1) and interleukin-21 (IL-21) mRNA in CD4(+) T cells and IgA(+) and IgM(+) in PP B cells, as well as intestinal mucosal injury and sIgA levels, were assessed. RESULTS: PD-1/PD-L1, TGF-ß1, and IL-21 expression was down-regulated after intestinal I/R. Furthermore, IgA(+) B cells decreased and IgM(+) B cells increased in mice with intestinal I/R. Importantly, decreased PD-1/PD-L1 expression was correlated with increased mucosal injury and decreased IgA levels, as well as with decreased TGF-ß1 and IL-21 expression. CONCLUSIONS: Intestinal I/R inhibits PD-1/PD-L1 expression on PP CD4(+) T cells, which was associated with an impaired intestinal immune system and mechanical barriers. Our study indicates that PD-1/PD-L1 expression on CD4(+) T cells may be involved in the pathogenesis of intestinal I/R injury.

Laryngeal mask airway does not reduce postoperative nasal bleeding outside the operation room after intranasal surgery.

BACKGROUND: The aim of this study was to detect the effect of the laryngeal mask airway (LMA) versus the endotracheal tube (ETT) on postoperative nasal bleedings in and outside the operation room (OR) after intranasal surgery. METHODS: 134 patients undergoing elective intranasal surgeries were randomly allocated to receive LMA or ETT during general anesthesia. The incidence, episodes, and severity of nasal bleeding were evaluated in the OR and within the postoperative 24 hours in the ward. Furthermore, medical assistance and severe complications were assessed. RESULTS: THE overall incidence of postoperative nasal bleeding throughout the observation period was similar between the two groups. The LMA reduced nasal bleeding in the OR. However, outside the OR, the incidence of the first episode of postoperative nasal bleeding in the LMA group was higher than that in the ETT group (difference: -26.5%; 95% CI: -42.2% to -10.7%; P < 0.001). In the LMA group, more patients needed medical assistance (P = 0.029), and the number of assistance was also higher (P = 0.027) in the ward. No severe complications occurred during the observation period. CONCLUSION: The LMA does not alleviate nasal bleeding conditions and even increases the demands of medical service outside the OR after intranasal surgery, although it reduces epistaxis during extubation.

Multiple-, but not single-, dose of parecoxib reduces shoulder pain after gynecologic laparoscopy.

BACKGROUND: The aim of this study was to investigate effect of single- and multiple-dose of parecoxib on shoulder pain after gynecologic laparoscopy. METHODS: 126 patients requiring elective gynecologic laparoscopy were randomly allocated to three groups. Group M (multiple-dose): receiving parecoxib 40mg at 30min before the end of surgery, at 8 and 20hr after surgery, respectively; Group S (single-dose): receiving parecoxib 40mg at 30min before the end of surgery and normal saline at the corresponding time points; Group C (control): receiving normal saline at the same three time points. The shoulder pain was evaluated, both at rest and with motion, at postoperative 6, 24 and 48hr. The impact of shoulder pain on patients' recovery (activity, mood, walking and sleep) was also evaluated. Meanwhile, rescue analgesics and complications were recorded. RESULTS: The overall incidence of shoulder pain in group M (37.5%) was lower than that in group C (61.9%) (difference=-24.4%; 95% CI: 3.4~45.4%; P=0.023). Whereas, single-dose regimen (61.0%) showed no significant reduction (difference with control=-0.9%; 95% CI: -21.9~20.0%; P=0.931). Moreover, multiple-dose regimen reduced the maximal intensity of shoulder pain and the impact for activity and mood in comparison to the control. Multiple-dose of parecoxib decreased the consumption of rescue analgesics. The complications were similar among all groups and no severe complications were observed. CONCLUSIONS: Multiple-, but not single-, dose of parecoxib may attenuate the incidence and intensity of shoulder pain and thereby improve patients' quality of recovery following gynecologic laparoscopy.

The efficacy of transversus abdominis plane block with or without dexmedetomidine for postoperative analgesia in renal transplantation. A randomized controlled trial.

BACKGROUND: Current options for effective postoperative analgesia after renal transplantation are limited, due to altered renal clearance and the risk of renal damage. This study compared the analgesic effect of the transversus abdominis plane block, with or without dexmedetomidine, in renal transplant recipients. MATERIALS AND METHODS: This prospective randomized double-blinded clinical trial was performed from November 2014 to March 2017. Patients were randomly divided into group C (morphine intravenous patient-controlled analgesia), group R (morphine intravenous patient-controlled analgesia and transversus abdominis plane block), and group RD (morphine intravenous patient-controlled analgesia and transversus abdominis plane block with 1 µg/kg dexmedetomidine). Morphine consumption, time to first request for analgesia, pain, sedation, nausea, vomiting, respiratory depression, and bradycardia were measured at 2, 4, 6, 12 and 24 h after surgery. RESULTS: The visual analogue pain score in group C was the highest among the three groups at the 2nd and 4th hour. Morphine consumption was the highest in group C at all assessed time intervals (p < 0.01). By the 12th hour and 24th hour, morphine consumption (calculated by time interval) was the lowest in group RD (p < 0.05), while no statistical difference was found between groups C and R. The average time to first request of analgesia was the longest and shortest in group RD and group C, respectively (p < 0.01). The overall incidence of nausea and vomiting was the highest in group C (p < 0.05). CONCLUSIONS: The transversus abdominis plane block reduced morphine consumption in the first 24 h following renal transplantation, and the addition of dexmedetomidine provided a more effective analgesic effect.

Parecoxib increases muscle pain threshold and relieves shoulder pain after gynecologic laparoscopy: a randomized controlled trial.

OBJECTIVES: Postlaparoscopic shoulder pain (PLSP) remains a common problem after laparoscopies. The aim of this study was to investigate the correlation between pressure pain threshold (PPT) of different muscles and PLSP after gynecologic laparoscopy, and to explore the effect of parecoxib, a cyclooxygenase-2 inhibitor, on the changes of PPT. MATERIALS AND METHODS: The patients were randomly allocated into two groups; group P and group C. In group P, parecoxib 40 mg was intravenously infused at 30 minutes before surgery and 8 and 20 hours after surgery. In group C, normal saline was infused at the corresponding time point. PPT assessment was performed 1 day before surgery and at postoperative 24 hours by using a pressure algometer at bilateral shoulder muscles (levator scapulae and supraspinatus) and forearm (flexor carpi ulnaris). Meanwhile, bilateral shoulder pain was evaluated through visual analog scale score at 24 hours after surgery. RESULTS: Preoperative PPT level of the shoulder, but not of the forearm, was significantly and negatively correlated with the intensity of ipsilateral PLSP. In group C, PPT levels of shoulder muscles, but not of forearm muscles, decreased after laparoscopy at postoperative 24 hours. The use of parecoxib significantly improved the decline of PPT levels of bilateral shoulder muscles (all P<0.01). Meanwhile, parecoxib reduced the incidence of PLSP (group P: 45% vs group C: 83.3%; odds ratio: 0.164; 95% confidence interval: 0.07-0.382; P<0.001) and the intensity of bilateral shoulder pain (both P<0.01). CONCLUSION: Preoperative PPT levels of shoulder muscles are closely associated with the severity of shoulder pain after gynecologic laparoscopy. PPT levels of shoulder muscles, but not of forearm muscles, significantly decreased after surgery. Parecoxib improved the decrease of PPT and relieved PLSP.