Cardiac Resolvin D2 ameliorates sepsis-induced cardiomyopathy via inhibiting Caspase-11/GSDMD dependent pyroptosis.

BACKGROUND: Sepsis-induced cardiomyopathy (SICM) is common complication in septic patients with a high mortality and is characterized by an abnormal inflammation response, which was precisely regulated by endogenous specialized pro-resolving mediators (SPMs). However, the metabolic changes of cardiac SPMs during SICM and the roles of SPMs subset in the development of SICM remain unknown. METHODS: In this work, the SPMs concentration was assessed using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) of SICM mice and SICM patients. The cardiac function was measured by echocardiography after the treatment of a SPMs subset, termed Resolvin D2 (RvD2). Caspase-11-/-, GSDMD-/- and double deficient (Caspase-11-/-GSDMD-/-) mice were used to clarify the mechanisms of RvD2 in SICM. RESULTS: We found that endogenous cardiac SPMs were disorders and RvD2 was decreased significantly and correlated with left ventricular ejection fraction (LVEF) and ß-BNP, cTnT in Lipopolysaccharide/Cecum ligation and puncture (CLP) induced SICM models. Treatment with RvD2 attenuated lethality, cardiac dysfunction and cardiomyocytes death during SICM. Mechanistically, RvD2 alleviated SICM via inhibiting Caspase-11/GSDMD-mediated cardiomyocytes pyroptosis. Finally, the plasma levels of RvD2 were also decreased and significantly correlated with IL-1ß, ß-BNP, cTnT and LVEF in patients with SICM. Of note, plasma RvD2 level is indicator of SICM patients from healthy controls or sepsis patients. CONCLUSION: These findings suggest that decreased cardiac RvD2 may involve in the pathogenesis of SICM. In addition, treatment with RvD2 represents a novel therapeutic strategy for SICM by inhibiting cardiomyocytes pyroptosis.

Efficient pulmonary lymphatic drainage is necessary for inflammation resolution in ARDS.

The lymphatic vasculature is the natural pathway for the resolution of inflammation, yet the role of pulmonary lymphatic drainage function in sepsis-induced acute respiratory distress syndrome (ARDS) remains poorly characterized. In this study, indocyanine green-near infrared lymphatic living imaging was performed to examine pulmonary lymphatic drainage function in septic mouse models. We found that the pulmonary lymphatic drainage was impaired owing to the damaged lymphatic structure in sepsis-induced ARDS. Moreover, prior lymphatic defects by blocking vascular endothelial growth factor receptor-3 (VEGFR-3) worsened sepsis-induced lymphatic dysfunction and inflammation. Posttreatment with vascular endothelial growth factor-C (Cys156Ser) (VEGF-C156S), a ligand of VEGFR-3, ameliorated lymphatic drainage by rejuvenating lymphatics to reduce the pulmonary edema and promote draining of pulmonary macrophages and neutrophils to pretracheal lymph nodes. Meanwhile, VEGF-C156S posttreatment reversed sepsis-inhibited CC chemokine ligand 21 (CCL21), which colocalizes with pulmonary lymphatic vessels. Furthermore, the advantages of VEGF-C156S on the drainage of inflammatory cells and edema fluid were abolished by blocking VEGFR-3 or CCL21. These results suggest that efficient pulmonary lymphatic drainage is necessary for inflammation resolution in ARDS. Our findings offer a therapeutic approach to sepsis-induced ARDS by promoting lymphatic drainage function.

Pro-Resolving Mediator Resolvin E1 Restores Alveolar Fluid Clearance in Acute Respiratory Distress Syndrome.

ABSTRACT: Acute respiratory distress syndrome (ARDS) is a life-threatening condition characterized by increased permeability of the alveolar-capillary barrier and impaired alveolar fluid clearance. Resolvin E1 (RvE1) is a specialized pro-resolving mediator derived endogenously from omega-3-polyunsaturated fatty acids. RvE1 (10 µg/kg i.v.) was injected to rats 6 h post-lipopolysaccharide (LPS) (14 mg/kg) induction. After another 3 h, alveolar fluid clearance was measured in live rats (n = 8-9). The primary Type II alveolar epithelial cell was isolated and treated by LPS (1 µg/mL) with or without RvE1 (250 nM). The expression of epithelial sodium channel (ENaC), Na+/K+-ATPase (NKA), AKT, serum- and glucocorticoid-induced kinase 1 (SGK1), and Nedd4-2 were detected. RvE1 improved survival rate (30% vs. 70%, P = 0.048), increased the clearance of alveolar fluid (13.34% vs. 18.73%, P  < 0.001), reduced lung wet-dry weight ratio (5.01 vs. 4.63, P  < 0.001), mitigated lung injury scores (13.38 vs. 7.0, P  < 0.05) and inflammation in LPS-induced ARDS in rats. RvE1 upregulated alveolar ENaC and NKA expression in vivo and in vitro. In addition, RvE1 significantly increased the expression of phosphorylated AKT, SGK1, and phosphorylated Nedd4-2 in LPS-stimulated primary alveolar type II cells. The effects of RvE1 were abrogated by blocking phosphatidylinositide3'-kinase (PI3K) and SGK1 with LY294002 and GSK650394, respectively. In summary, RvE1 upregulated ENaC and NKA expression by activating PI3K/AKT/SGK1 pathway to promote alveolar fluid clearance, suggesting that RvE1 may be a potentially effective drug for ARDS treatment.

Resolvin Conjugates in Tissue Regeneration 1 Promote Alveolar Fluid Clearance by Activating Alveolar Epithelial Sodium Channels and Na, K-ATPase in Lipopolysaccharide-Induced Acute Lung Injury.

Acute respiratory distress syndrome (ARDS), a common and fatal clinical condition, is characterized by the destruction of epithelium and augmented permeability of the alveolar-capillary barrier. Resolvin conjugates in tissue regeneration 1 (RCTR1) is an endogenous lipid mediator derived from docosahexaenoic acid , exerting proresolution effects in the process of inflammation. In our research, we evaluated the role of RCTR1 in alveolar fluid clearance (AFC) in lipopolysaccharide-induced ARDS/acute lung injury (ALI) rat model. Rats were injected with RCTR1 (5 µg/kg) via caudal veins 8 hours after lipopolysaccharide (LPS) (14 mg/kg) treatment, and then AFC was estimated after 1 hour of ventilation. Primary type II alveolar epithelial cells were incubated with LPS (1 ug/ml) with or without RCTR1 (10 nM) for 8 hours. Our results showed that RCTR1 significantly enhanced the survival rate, promoted the AFC, and alleviated LPS-induced ARDS/ALI in vivo. Furthermore, RCTR1 remarkably elevated the protein expression of sodium channels and Na, K-ATPase and the activity of Na, K-ATPase in vivo and in vitro. Additionally, RCTR1 also decreased neural precursor cell expressed developmentally downregulated 4-2 (Nedd4-2) level via upregulating Ser473-phosphorylated-Akt expression. Besides this, inhibitors of receptor for lipoxin A4 (ALX), cAMP, and phosphatidylinositol 3-kinase (PI3K) (BOC-2, KH-7, and LY294002) notably inhibited the effects of RCTR1 on AFC. In summary, RCTR1 enhances the protein levels of sodium channels and Na, K-ATPase and the Na, K-ATPase activity to improve AFC in ALI through ALX/cAMP/PI3K/Nedd4-2 pathway, suggesting that RCTR1 may become a therapeutic drug for ARDS/ALI. SIGNIFICANCE STATEMENT: RCTR1, an endogenous lipid mediator, enhanced the rate of AFC to accelerate the resolution of inflammation in the LPS-induced murine lung injury model. RCTR1 upregulates the expression of epithelial sodium channels (ENaCs) and Na, K-ATPase in vivo and in vitro to accelerate the AFC. The efficacy of RCTR1 on the ENaC and Na, K-ATPase level was in an ALX/cAMP/PI3K/Nedd4-2-dependent manner.

Dexmedetomidine promotes inflammation resolving through TGF-ß1 secreted by F4/80+Ly6G+ macrophage.

Dexmedetomidine (DEX) is a highly selective α2-adrenoceptor agonist, which can regulate inflammatory responses. However, whether DEX interferes with the inflammation resolving remains unclear. Here, we reported the effects of DEX on zymosan-induced generalized inflammation in mice during resolution. Mice were administered intraperitoneally with DEX after the initiation of sepsis. The resolution interval (Ri), a vital resolution indice, decreased from twelve hours to eight hours after the administration of DEX. The induction of peritoneal pro-inflammatory interleukin [IL] - 1ß and tumour necrosis factor-α (TNF-α) appeared to be inhibited. Of interest, the anti-inflammatory transforming growth factor-ß1 (TGF-ß1) but not IL-10 levels were up-regulated at twenty-four hours in the DEX group along with 1.0 mg/mice zymosan A (ZyA) treatment. The expression levels of multiple genes related to protective immune processes and clearance functions were detected and revealed the same trends. DEX markedly increased the F4/80+Ly6G+ macrophage population. Additionally, the adequate apoptotic neutrophil clearance from injury after DEX installation could be reverse by opsonization or co-instillation of TGF-ß1 neutralizing antibody in vivo, promoting the inflammation-resolution programs. In conclusion, DEX post-treatment, via the increase of F4/80+Ly6G+ macrophages, provokes further secretion of TGF-ß1, leading to the attenuated cytokine storm and accelerated inflammation resolving.

PCTR1 improves pulmonary edema fluid clearance through activating the sodium channel and lymphatic drainage in lipopolysaccharide-induced ARDS.

Acute respiratory distress syndrome (ARDS) is a lethal clinical syndrome characterized by damage of the epithelial barriers and accumulation of pulmonary edema fluid. Protectin conjugates in tissue regeneration 1 (PCTR1), an endogenously produced lipid mediator, are believed to exert anti-inflammatory and pro-resolution effects. PCTR1 (1 µg/kg) was injected at 8 hr after lipopolysaccharide (LPS; 14 mg/kg) administration, and the rate of pulmonary fluid clearance was measured in live rats at 1 hr after PCTR1 treatment. The primary type II alveolar epithelial cells were cultured with PCTR1 (10 nmol/ml) and LPS (1 µg/ml) for 8 hr. PCTR1 effectively improved pulmonary fluid clearance and ameliorated morphological damage and reduced inflammation of lung tissue, as well as improved the survival rate in the LPS-induced acute lung injury (ALI) model. Moreover, PCTR1 markedly increased sodium channel expression as well as Na, K-ATPase expression and activity in vivo and in vitro. In addition, PCTR1i also upregulated the expression of LYVE-1 in vivo. Besides that, BOC-2, HK7, and LY294002 blocked the promoted effect of PCTR1 on pulmonary fluid clearance. Taken together, PCTR1 upregulates sodium channels' expression via activating the ALX/cAMP/P-Akt/Nedd4-2 pathway and increases Na, K-ATPase expression and activity to promote alveolar fluid clearance. Moreover, PCTR1 also promotes the expression of LYVE-1 to recover the lymphatic drainage resulting in the increase of lung interstitial fluid clearance. In summary, these results highlight a novel systematic mechanism for PCTR1 in pulmonary edema fluid clearance after ALI/ARDS, suggesting its potential role in a therapeutic approach for ALI/ARDS.

Maresin Conjugates in Tissue Regeneration 1 improves alveolar fluid clearance by up-regulating alveolar ENaC, Na, K-ATPase in lipopolysaccharide-induced acute lung injury.

Maresin Conjugates in Tissue Regeneration 1 (MCTR1) is a newly identified macrophage-derived sulfido-conjugated mediator that stimulates the resolution of inflammation. This study assessed the role of MCTR1 in alveolar fluid clearance (AFC) in a rat model of acute lung injury (ALI) induced by lipopolysaccharide (LPS). Rats were intravenously injected with MCTR1 at a dose of 200 ng/rat, 8 hours after administration of 14 mg/kg LPS. The level of AFC was then determined in live rats. Primary rat ATII (Alveolar Type II) epithelial cells were also treated with MCTR1 (100 nmol/L) in a culture medium containing LPS for 8 hours. MCTR1 treatment improved AFC (18.85 ± 2.07 vs 10.11 ± 1.08, P < .0001) and ameliorated ALI in rats. MCTR1 also significantly promoted AFC by up-regulating epithelial sodium channel (ENaC) and Na+ -K+ -adenosine triphosphatase (Na, K-ATPase) expressions in vivo. MCTR1 also activated Na, K-ATPase and elevated phosphorylated-Akt (P-Akt) by up-regulating the expression of phosphorylated Nedd4-2 (P-Nedd4-2) in vivo and in vitro. However, BOC-2 (ALX inhibitor), KH7 (cAMP inhibitor) and LY294002 (PI3K inhibitor) abrogated the improved AFC induced by MCTR1. Based on the findings of this study, MCTR1 may be a novel therapeutic approach to improve reabsorption of pulmonary oedema during ALI/acute respiratory distress syndrome (ARDS).

Peak Systolic Velocity Measurements with Transcranial Doppler Ultrasound Is a Predictor of Incident Stroke among the General Population in China.

BACKGROUND AND OBJECTIVE: It is necessary to develop an effective and low-cost screening tool for identifying Chinese people at high risk of stroke. Transcranial Doppler ultrasound (TCD) is a powerful predictor of stroke in the pediatric sickle cell disease population, as demonstrated in the STOP trial. Our study was conducted to determine the prediction value of peak systolic velocities as measured by TCD on subsequent stroke risk in a prospective cohort of the general population from Beijing, China. METHODS: In 2002, a prospective cohort study was conducted among 1392 residents from 11 villages of the Shijingshan district of Beijing, China. The cohort was scheduled for follow up with regard to incident stroke in 2005, 2007, and 2012 by a study team comprised of epidemiologists, nurses, and physicians. Univariate and multivariate Cox proportional hazard regression models were used to determine the factors associated with incident stroke. RESULTS: Participants identified by TCD criteria as having intracranial stenosis had a 3.6-fold greater risk of incident stroke (hazard ratio (HR) 3.57, 95% confidence interval (CI) 1.86-6.83, P<0.01) than those without TCD evidence of intracranial stenosis. The association remained significant in multivariate analysis (HR 2.53, 95% CI 1.31-4.87) after adjusting for other risk factors or confounders. Older age, cigarette smoking, hypertension, and diabetes mellitus remained statistically significant as risk factors after controlling for other factors. CONCLUSIONS: The study confirmed the screening value of TCD among the general population in urban China. Increasing the availability of TCD screening may help identify subjects as higher risk for stroke.

Apolipoprotein M: Research progress, regulation and metabolic functions (Review).

Apolipoprotein M (ApoM) is a novel lipoprotein-associated plasma protein of the apolipoprotein family. It is predominantly enriched in high-density lipoprotein (HDL), and is also present in small quantities in low-density lipoprotein (LDL) and in very low-density lipoprotein. Transgenic animal experiments have suggested that ApoM can be transformed into various lipoproteins and may be involved in lipoprotein metabolism. ApoM has five subtypes, however, their biological functions remain to be elucidated. The α-helix, formed by ApoM through hydrophobic signal peptides, is anchored to the phospholipid monomolecular layers of HDL. Hydrophobic domains can associate with small lipophilic ligands and perform biological functions. ApoM may affect HDL metabolism and exhibit anti-atherosclerotic functions. Human HDL, containing ApoM subfractions, can protect LDL from oxidation and regulate cholesterol efflux more effectively than HDL without ApoM. Therefore, it is highly correlated with plasma cholesterol levels in the human body. Although previous studies have reported no difference in ApoM between groups of patients with coronary heart disease (CHD) and a normal control groups, the anti-atherosclerotic effect of ApoM is evident. ApoM is highly expressed in renal proximal tubule cells and is secreted into the urine in tubule cells. However, it is usually reabsorbed by giantin-associated proteins in a process, which is also affected in kidney disease. In addition to liver and kidney cells, low expression levels of ApoM occur in the intestinal tract and are associated with lymph node metastasis of colorectal cancer. ApoM gene polymorphism is associated with CHD, diabetes and other immune-associated diseases. Investigations into the gene regulation of ApoM may assist in further clarifying the role of ApoM in blood glucose and lipid metabolism. Genetic modification of the mouse ApoM gene is an essential technique to investigate the gene expression and regulation of ApoM, and to clarify the potential roles of ApoM in lipoprotein metabolism, atherosclerosis, diabetes and renal diseases.

Gender differences in age-related decline in glomerular filtration rates in healthy people and chronic kidney disease patients.

BACKGROUND: Since men with chronic kidney disease (CKD) progress faster than women, an accurate assessment of CKD progression rates should be based on gender differences in age-related decline of glomerular filtration rate (GFR) in healthy individuals. METHODS: A Chinese sample population from a stratified, multistage, and clustered CKD screening study was classified into healthy, at-risk, and CKD groups. The gender differences in estimated GFR (eGFR) and age-related eGFR decline were calculated for each group after controlling for blood pressure, fasting glucose levels, serum lipids levels, education level, and smoking status. After referencing to the healthy group, gender-specific multivariate-adjusted rates of decline in eGFR and differences in the rates of decline were calculated for both CKD and at-risk groups. RESULTS: The healthy, at-risk, and CKD groups consisted of 4569, 7434, and 1573 people, respectively. In all the 3 groups, the multivariate-adjusted eGFRs in men were lower than the corresponding eGFRs in women. In addition, in the healthy and at-risk groups, the rates of decline in eGFR in men were lower than the corresponding rates of decline in women (healthy group: 0.51 mLxmin-1x1.73 m-2·yr-1 vs. 0.74 mLxmin-1x1.73 m-2xyr-1 and at-risk group: 0.60 mLxmin-1x1.73 m-2xyr-1 vs. 0.73 mLxmin-1x1.73 m-2xyr-1). However, in the CKD group, the rates of decline in eGFR in men were similar to those in women (0.96 mLxmin-1x1.73 m-2xyr-1 vs. 0.91 mLxmin-1x1.73 m-2xyr-1). However, after referencing to the healthy group, the rates of decline in eGFR in men in the at-risk and CKD groups were greater faster than the corresponding rates in women (at-risk group: 0.10 mLxmin-1x1.73 m-2·yr-1 vs. -0.03 mLxmin-1x1.73 m-2xyr-1 and CKD group: 0.44 mLxmin-1x1.73 m-2·yr-1 vs. 0.15 mLxmin-1x1.73 m-2xyr-1). CONCLUSION: To accurately assess gender differences in CKD progression rates, gender differences in age-related decline in GFR should be considered.

[Assessment of therapeutic effects of stem cell transplantation in heart failure patients with old myocardial infarction by magnetic resonance imaging].

OBJECTIVE: To evaluate the therapeutic effects of stem cell transplantation in heart failure patients with old myocardial infarction (OMI) by MRI. METHODS: Heart failure patients [NYHA 2.7 +/- 0.7, male = 18, mean age (59.5 +/- 10.1) y] with OMI were randomly divided into 2 groups (group A: CABG + stem cell transplantation, group B: CABG; n = 10 each). Left ventricular (LV) function was measured by MRI, viable myocardium was detected by (18)F-FDG myocardial metabolism imaging and late contrast-enhanced at baseline and 6 months post intervention. RESULTS: LVEF and LVEDV at baseline for group A were (20.71 +/- 6.09)% and (172.73 +/- 32.74) ml, and for group B were (27.59 +/- 2.31)% and (155.13 +/- 28.36) ml, respectively (P > 0.05). The LVEF was equally improved in group A and B (mean 8.63% vs. 10.37%, P > 0.05) while DeltaLVEDV was significant higher in group A than that in group B [(9.91 +/- 39.50) ml vs. (-22.34 +/- 31.35) ml, P < 0.05]. Ventricular wall thickening ratio at 6 months post intervention was significantly higher in group A than that in group B [(11.40 +/- 11.53)% vs. (2.27 +/- 7.20)%, P < 0.05]. Late contrast-enhanced MRI results correlated with (18)F-FDG myocardial metabolism imaging SPECT well in assessment of myocardial viability (kappa value: 0.446, P < 0.001; sensitivity: 68.3% and specificity: 92.5%). CONCLUSIONS: Stem cell therapy on top of CABG aggravated LV remodeling in heart failure patients with old myocardial infarction. The specificity of MRI is similar to (18)F-FDG SPECT while the sensitivity is inferior to (18)F-FDG SPECT on detecting viable myocardium.

[Study on chronic disease related behavior and lifestyle in adults in Beijing, 2005].

OBJECTIVE: To understand the distribution of chronic disease related behavior and lifestyle in adults from Beijing. METHODS: 16,658 adult residents from Beijing city were randomly selected with stratified multi-stage cluster sampling method in 2005. Each participant was invited to receive a set of standardized questionnaire, physical examinations and laboratory tests. RESULTS: In the adults living in Beijing, 33.2% were overweight and 16.4% were obesive. The current smoking rate was 26.2% and the regular smoking rate was 21.4%. 57.7% of the male and 4.6% of the female adults were current smokers. In male adults, 64.3% drank alcoholic beverage at least once per month while 16.1% drank almost everyday, 16.5% drank more alcohol than moderate, and 18.5% were binge drinkers. 46.0% of Beijing adults were in lack of active physical exercise. Unhealthy dietary habits such as:excess consumption of sodium or oil, lower intake of vegetable, milk and soybean productions, skipping breakfast, fond of salted vegetable and fried food intake, as well as eating snacks etc. were quite commonly seen in the adults from Beijing. In addition, most of the risk factors had a higher prevalence in the suburban areas and population at working-age. CONCLUSION: The prevalence rate of chronic risk factors was still high in adults of Beijing. Effective interventions should be carried out to prevent further worsening of the situation, especially in the suburban areas and people at working-age.