Interleukin-1ß stimulated macrophage derived exosomes improve myocardial injury in sepsis via regulation of mitochondrial homeostasis: Experimental research.

BACKGROUND: The purpose of this study was to investigate the effects of interleukin-1ß (IL-1ß) stimulation on the protection of macrophage derived exosomes miR-146a (M-IL-exo-146a) on sepsis induced myocardial injury (SMI) in vitro and in vivo. METHODS: Macrophage derived exosomes (M-exo) and IL-1ß stimulated macrophage exosomes (M-IL-exo) were isolated from macrophages of sepsis with or without IL-1ß. The expressions of miR-146a in M-exo and M- IL-exo were detected by fluorescence quantitative PCR. Related molecular biology technologies were used to evaluate the role and mechanism of M-exo-146a and M-IL-exo-146a on SMI and the enhancing effect of IL-1ß. RESULTS: Compared with M-exo, the expression of miR-146a in M-IL-exo was significantly increased. M-IL-exo-146a significantly alleviated SMI by decreasing the level of serum myocardial enzymes, serum and myocardial oxidative stress and cytokines, and improved myocardial mitochondrial imbalance. The mechanism responsible for IL-1ß enhancing the production of IL-M-exo miR-146a was via JNK-1/2 signal pathway. The mechanism responsible for M-exo-IL-miR-146a protecting SMI was related to miR-146a inhibiting inflammatory response and mitochondrial function via MAPK4/Drp1 signal pathway. CONCLUSIONS: This study provides a new strategy for the treatment of SMI by delivering IL-1ß stimulated macrophage derived exosomes.

Exosomes miRNA-499a-5p targeted CD38 to alleviate anthraquinone induced cardiotoxicity: experimental research.

BACKGROUND: The purpose of this study was to investigate the effects of cardiac homing peptide (CHP) engineered bone marrow mesenchymal stem cells (BMMSc) derived exosomes (B-exo) loaded miRNA-499a-5p on doxorubicin (DOX) induced cardiotoxicity. METHODS: miRNA chip analysis was used to analyze the differences between DOX induced H9c2 cells and control group. CHP engineering was performed on BMMSc derived exosomes to obtain C-B-exo. miRNA-499a-5p mimic was introduced into C-B-exo by electroporation technology to obtain C-B-exo-miRNA-499a-5p. DOX was used to establish a model of cardiotoxicity to evaluate the effects of C-B-exo- miRNA-499a-5p in vivo and in vitro . Western blot, immunohistochemistry, immunofluorescence, and other molecular biology methods were used to evaluate the role and mechanism of C-B-exo-miRNA-499a-5p on DOX induced cardiotoxicity. RESULTS: miRNA chip analysis revealed that miRNA-499a-5p was one of the most differentially expressed miRNAs and significantly decreased in DOX induced H9c2 cells as compared to the control group. Exo-and B-exo have a double-layer membrane structure in the shape of a saucer. After engineering the CHP of B-exo, the results showed that the delivery of miRNA-499a-5p significantly increased and significantly reached the target organ (heart). The experimental results showed that C-B-exo-miRNA-499a-5p significantly improved electrocardiogram, decreased myocardial enzyme, serum and cardiac cytokines, improved cardiac pathological changes, inhibited CD38/MAPK/NF-κB signal pathway. CONCLUSIONS: In this study, C-B-exo-miRNA-499a-5p significantly improved DOX-induced cardiotoxicity via CD38/MAPK/NF-κB signal pathway, providing a new idea and method for the treatment of DOX induced cardiotoxicity.

Radix Sanguisorbae Improves Intestinal Barrier in Septic Rats via HIF-1 α/HO-1/Fe2+ Axis.

OBJECTIVE: To investigate whether Radix Sanguisorbae (RS, Diyu) could restore intestinal barrier function following sepsis using a cecal ligation and puncture (CLP)-induced septic rat model and lipopolysaccharide (LPS)-challenged IEC-6 cell model, respectively. METHODS: Totally 224 rats were divided into 4 groups including a control, sham, CLP and RS group according to a random number table. The rats in the control group were administrated with Ringer's lactate solution (30 mL/kg) with additional dopamine [10 µ g/(kg·min)] and given intramuscular injections of cefuroxime sodium (10 mg/kg) 12 h following CLP. The rats in the RS group were administrated with RS (10 mg/kg) through tail vein 1 h before CLP and treated with RS (10 mg/kg) 12 h following CLP. The rats in the sham group were only performed abdominal surgery without CLP. The rats in the CLP group were performed with CLP without any treatment. The other steps were same as control group. The effects of RS on intestinal barrier function, mesenteric microvessels barrier function, multi-organ function indicators, inflammatory response and 72 h survival window following sepsis were observed. In vitro, the effects of RS on LPS-challenged IEC-6 cell viability, the expressions of zona occludens-1 (ZO-1) and ferroptosis index were evaluated by cell counting kit-8, immunofluorescence and Western blot analysis. Bioinformatic tools were applied to investigate the pharmacological network of RS in sepsis to predict the active compounds and potential protein targets and pathways. RESULTS: The sepsis caused severe intestinal barrier dysfunction, multi-organ injury, lipid peroxidation accumulation, and ferroptosis in vivo. RS treatment significantly prolonged the survival time to 56 h and increased 72-h survival rate to 7/16 (43.75%). RS also improved intestinal barrier function and relieved intestinal inflammation. Moreover, RS significantly decreased lipid peroxidation and inhibited ferroptosis (P<0.05 or P<0.01). Administration of RS significantly worked better than Ringer's solution used alone. Using network pharmacology prediction, we found that ferroptosis and hypoxia inducible factor-1 (HIF-1 α) signaling pathways might be involved in RS effects on sepsis. Subsequent Western blot, ferrous iron measurements, and FerroOrange fluorescence of ferrous iron verified the network pharmacology predictions. CONCLUSION: RS improved the intestinal barrier function and alleviated intestinal injury by inhibiting ferroptosis, which was related in part to HIF-1 α/heme oxygenase-1/Fe2+ axis.

Neutrophil membrane-engineered Panax ginseng root-derived exosomes loaded miRNA 182-5p targets NOX4/Drp-1/NLRP3 signal pathway to alleviate acute lung injury in sepsis: experimental studies.

BACKGROUND: The purpose of this study was to prepare neutrophil membrane-engineered Panax ginseng root-derived exosomes (N-exo) and investigate the effects of N-exo microRNA (miRNA) 182-5p (N-exo-miRNA 182-5p) on acute lung injury (ALI) in sepsis. METHODS: Panax ginseng root-derived exosomes were separated by differential centrifugation. Neutrophil membrane engineering was performed on exo to obtain N-exo. miRNA182-5p was transmitted into N-exo by electroporation technology to obtain N-exo-miRNA 182-5p. LPS was used to establish an in-vivo and in-vitro model of ALI of sepsis to evaluate the anti-inflammatory effect of N-exo-miRNA 182-5p. RESULTS: The results of transmission electron microscope showed that exo was a double-layer membrane structure like a saucer. Nanoparticle size analysis showed that the average particle size of exo was 129.7 nm. Further, compared with exo, the level of miRNA182-5p was significantly increased in N-exo. The experimental results showed that N-exo-miRNA 182-5p significantly improved ALI via target regulation of NOX4/Drp-1/NLRP3 signal pathway in vivo and in vitro . CONCLUSION: In conclusion, this study prepared a novel engineered exosome (N-exo and N-exo-miRNA 182-5p significantly improved ALI in sepsis via target regulation of NOX4/Drp-1/NLRP3 signal pathway, providing new ideas and methods for treatment of ALI in sepsis.

Metabolomics and machine learning approaches for diagnostic and prognostic biomarkers screening in sepsis.

BACKGROUND: Sepsis is a life-threatening disease with a poor prognosis, and metabolic disorders play a crucial role in its development. This study aims to identify key metabolites that may be associated with the accurate diagnosis and prognosis of sepsis. METHODS: Septic patients and healthy individuals were enrolled to investigate metabolic changes using non-targeted liquid chromatography-high-resolution mass spectrometry metabolomics. Machine learning algorithms were subsequently employed to identify key differentially expressed metabolites (DEMs). Prognostic-related DEMs were then identified using univariate and multivariate Cox regression analyses. The septic rat model was established to verify the effect of phenylalanine metabolism-related gene MAOA on survival and mean arterial pressure after sepsis. RESULTS: A total of 532 DEMs were identified between healthy control and septic patients using metabolomics. The main pathways affected by these DEMs were amino acid biosynthesis, phenylalanine metabolism, tyrosine metabolism, glycine, serine and threonine metabolism, and arginine and proline metabolism. To identify sepsis diagnosis-related biomarkers, support vector machine (SVM) and random forest (RF) algorithms were employed, leading to the identification of four biomarkers. Additionally, analysis of transcriptome data from sepsis patients in the GEO database revealed a significant up-regulation of the phenylalanine metabolism-related gene MAOA in sepsis. Further investigation showed that inhibition of MAOA using the inhibitor RS-8359 reduced phenylalanine levels and improved mean arterial pressure and survival rate in septic rats. Finally, using univariate and multivariate cox regression analysis, six DEMs were identified as prognostic markers for sepsis. CONCLUSIONS: This study employed metabolomics and machine learning algorithms to identify differential metabolites that are associated with the diagnosis and prognosis of sepsis patients. Unraveling the relationship between metabolic characteristics and sepsis provides new insights into the underlying biological mechanisms, which could potentially assist in the diagnosis and treatment of sepsis. TRIAL REGISTRATION: This human study was approved by the Ethics Committee of the Research Institute of Surgery (2021-179) and was registered by the Chinese Clinical Trial Registry (Date: 09/12/2021, ChiCTR2200055772).

Identification of MMP9 as a Novel Biomarker to Mitochondrial Metabolism Disorder and Oxidative Stress in Calcific Aortic Valve Stenosis.

Calcific aortic valve stenosis (CAVS) is the most common heart valve disorder among humans. To date, no effective method has been identified to prevent this disease. Herein, we aimed to identify novel diagnostic and mitochondria-related biomarkers of CAVS, based on two machine learning algorithms. We further explored their association with infiltrating immune cells and studied their potential function in CAVS. The GSE12644, GSE51472, and GSE83453 expression profiles were downloaded from the Gene Expression Omnibus (GEO) repository. The GSE12644 and GSE51472 datasets were integrated to identify differentially expressed genes (DEGs). GSE12644 contains 10 normal and 10 CAVS samples, whereas GSE51472 contains 5 normal and 10 CAVS samples. GO and KEGG assays of DEGs were conducted, and the correlation between matrix metalloproteinase 9 (MMP9) expression and immune cell infiltration was explored, using CIBERSORT. The LASSO regression model and SVM-RFE analysis were used to identify diagnostic genes. The expression of MMP9 in CAVS and non-CAVS samples was measured using RT-PCR, western blotting and immunohistochemistry. A series of functional experiments were performed to explore the potential role of MMP9 in mitochondrial metabolism and oxidative stress during CAVS progression. Twenty-two DEGs were identified, of which six genes (SCG2, PPBP, TREM1, CCL19, WIF1, and MMP9) were ultimately distinguished as diagnostic genes in CAVS. Of these, MMP9 was indicated as a mitochondria-related gene, the expression and diagnostic value of which were further confirmed in the GSE83453 dataset. Correlation analysis revealed a positive correlation between MMP9 and infiltrating immune cells. In our cohort, MMP9 expression was distinctly increased in CAVS samples, and its inhibition attenuated the calcification of valve interstitial cells (VICs) by suppressing mitochondrial damage and oxidative stress. Taken together, our findings suggest MMP9 as a novel mitochondrial dysfunction biomarker and therapeutic target for CAVS.

N-Acetyl-L-Cysteine Protects Organ Function After Hemorrhagic Shock Combined With Seawater Immersion in Rats by Correcting Coagulopathy and Acidosis.

Background: The mortality of trauma combined with seawater immersion is higher than that of land injury, however, research on how to treat this critical case and which treatments to adopt is lacking. Methods: The effect of the thiol compound, N-acetyl-L-Cysteine (NAC), on survival, acidosis, coagulopathy, vital signs, oxidative stress, and mitochondrial and multi-organ function was assessed in a rat model of hemorrhagic shock combined with seawater immersion (Sea-Shock). Results: Hemorrhagic shock combined with seawater immersion caused a severe lethal triad: multi-organ impairment, oxidative stress, and mitochondrial dysfunction. NAC (30 mg/kg) with lactated Ringer's (LR) solution (2 × blood volume lost) significantly improved outcomes compared to LR or hetastarch (HES 130/0.4) alone. NAC significantly prolonged survival time to 52.48 ± 30.09 h and increased 72 h survival rate to 11/16 (68%). NAC relieved metabolic acidosis and recovered the pH back to 7.33. NAC also restored coagulation, with APTT, PT, and PT-INR decreased by 109.31, 78.09, and 73.74%, respectively, while fibrinogen level increased 246.23% compared with untreated Sea-Shock. Administration of NAC markedly improved cardiac and liver function, with some improvement of kidney function. Conclusion: The addition of NAC to crystalloid resuscitation fluid alleviated oxidative stress, restored redox homeostasis, and provided multi-organ protection in the rats after Sea-Shock. NAC may be an effective therapeutic measure for hemorrhagic shock combined with seawater immersion.

The Characteristics of Organ Function Damage of Hemorrhagic Shock in Hot Environment and the Effect of Hypothermic Fluid Resuscitation.

BACKGROUND: Hemorrhagic shock is the important factor for causing death of trauma and war injuries. However, pathophysiological characteristics and underlying mechanism in hemorrhagic shock with hot environment remain unclear. METHODS: Hemorrhagic shock in hot environment rat model was used to explore the changes of mitochondrial and vital organ functions, the variation of the internal environment, stress factors, and inflammatory factors; meanwhile, the suitable treatment was further studied. RESULTS: Above 36°C hot environment induced the increase of core temperature of rats, and the core temperature was not increased in 34°C hot environment, but the 34°C hot environment aggravated significantly hemorrhagic shock induced mortality. Further study showed that the mitochondrial functions of heart, liver, and kidney were more damaged in hemorrhagic shock rats with 34°C hot environment as compared with room environment. Moreover, the results showed that in hemorrhagic shock rats with hot environment, the blood concentration of Na+, K+, and plasma osmotic pressure, the expression of inflammatory factors tumor necrosis factor-α and interleukin-6 in the serum, as well as the stress factors Adrenocorticotropic Hormone and Glucocorticoid were all notably enhanced; and acidosis was more serous; oxygen supply and oxygen consumption were remarkably decreased. In addition, the present study demonstrated that mild hypothermia (10°C) fluid resuscitation could significantly improve the survival rate in hemorrhagic shock rats with hot environment as compared with normal temperature fluid resuscitation. CONCLUSIONS: Hot environment accelerated the death of hemorrhagic shock rats, which was related to the disorder of internal environment, the increase of inflammatory and stress factors. Furthermore, moderate hypothermic (10°C) fluid resuscitation was suitable for the treatment of hemorrhagic shock in hot environment.

Protective Effects of Inhibition of Mitochondrial Fission on Organ Function After Sepsis.

Sepsis-associated organ dysfunction plays a critical role in its high mortality, mainly in connection with mitochondrial dysfunction. Whether the inhibition of mitochondrial fission is beneficial to sepsis-related organ dysfunction and underlying mechanisms are unknown. Cecal ligation and puncture induced sepsis in rats and dynamic related protein 1 knockout mice, lipopolysaccharide-treated vascular smooth muscle cells and cardiomyocytes, were used to explore the effects of inhibition of mitochondrial fission and specific mechanisms. Our study showed that mitochondrial fission inhibitor Mdivi-1 could antagonize sepsis-induced organ dysfunction including heart, vascular smooth muscle, liver, kidney, and intestinal functions, and prolonged animal survival. The further study showed that mitochondrial functions such as mitochondrial membrane potential, adenosine-triphosphate contents, reactive oxygen species, superoxide dismutase and malonaldehyde were recovered after Mdivi-1 administration via improving mitochondrial morphology. And sepsis-induced inflammation and apoptosis in heart and vascular smooth muscle were alleviated through inhibition of mitochondrial fission and mitochondrial function improvement. The parameter trends in lipopolysaccharide-stimulated cardiomyocytes and vascular smooth muscle cells were similar in vivo. Dynamic related protein 1 knockout preserved sepsis-induced organ dysfunction, and the animal survival was prolonged. Taken together, this finding provides a novel effective candidate therapy for severe sepsis/septic shock and other critical clinical diseases.

Mesenchymal stem cell-derived microvesicles improve intestinal barrier function by restoring mitochondrial dynamic balance in sepsis rats.

BACKGROUND: Sepsis is a major cause of death in ICU, and intestinal barrier dysfunction is its important complication, while the treatment is limited. Recently, mesenchymal stem cell-derived microvesicles (MMVs) attract much attention as a strategy of cell-free treatment; whether MMVs are therapeutic in sepsis induced-intestinal barrier dysfunction is obscure. METHODS: In this study, cecal ligation and puncture-induced sepsis rats and lipopolysaccharide-stimulated intestinal epithelial cells to investigate the effect of MMVs on intestinal barrier dysfunction. MMVs were harvested from mesenchymal stem cells and were injected into sepsis rats, and the intestinal barrier function was measured. Afterward, MMVs were incubated with intestinal epithelial cells, and the effect of MMVs on mitochondrial dynamic balance was measured. Then the expression of mfn1, mfn2, OPA1, and PGC-1α in MMVs were measured by western blot. By upregulation and downregulation of mfn2 and PGC-1α, the role of MMVs in mitochondrial dynamic balance was investigated. Finally, the role of MMV-carried mitochondria in mitochondrial dynamic balance was investigated. RESULTS: MMVs restored the intestinal barrier function by improving mitochondrial dynamic balance and metabolism of mitochondria. Further study revealed that MMVs delivered mfn2 and PGC-1α to intestinal epithelial cells, and promoted mitochondrial fusion and biogenesis, thereby improving mitochondrial dynamic balance. Furthermore, MMVs delivered functional mitochondria to intestinal epithelial cells and enhanced energy metabolism directly. CONCLUSION: MMVs can deliver mfn2, PGC-1α, and functional mitochondria to intestinal epithelial cells, synergistically improve mitochondrial dynamic balance of target cells after sepsis, and restore the mitochondrial function and intestinal barrier function. The study illustrated that MMVs might be a promising strategy for the treatment of sepsis.

Synergistic effects of EMPs and PMPs on pulmonary vascular leakage and lung injury after ischemia/reperfusion.

BACKGROUND: Vascular leakage is an important pathophysiological process of critical conditions such as shock and ischemia-reperfusion (I/R)-induced lung injury. Microparticles (MPs), including endothelial cell-derived microparticles (EMPs), platelet-derived microparticles (PMPs) and leukocyte-derived microparticles (LMPs), have been shown to participate in many diseases. Whether and which of these MPs take part in pulmonary vascular leakage and lung injury after I/R and whether these MPs have synergistic effect and the underlying mechanism are not known. METHODS: Using hemorrhage/transfusion (Hemo/Trans) and aorta abdominalis occlusion-induced I/R rat models, the role of EMPs, PMPs and LMPs and the mechanisms in pulmonary vascular leakage and lung injury were observed. RESULTS: The concentrations of EMPs, PMPs and LMPs were significantly increased after I/R. Intravenous administration of EMPs and PMPs but not LMPs induced pulmonary vascular leakage and lung injury. Furthermore, EMPs induced pulmonary sequestration of platelets and promoted more PMPs production, and played a synergistic effect on pulmonary vascular leakage. MiR-1, miR-155 and miR-542 in EMPs, and miR-126 and miR-29 in PMPs, were significantly increased after hypoxia/reoxygenation (H/R). Of which, inhibition of miR-155 in EMPs and miR-126 in PMPs alleviated the detrimental effects of EMPs and PMPs on vascular barrier function and lung injury. Overexpression of miR-155 in EMPs down-regulated the expression of tight junction related proteins such as ZO-1 and claudin-5, while overexpression of miR-126 up-regulated the expression of caveolin-1 (Cav-1), the trans-cellular transportation related protein such as caveolin-1 (Cav-1). Inhibiting EMPs and PMPs production with blebbistatin (BLE) and amitriptyline (AMI) alleviated I/R induced pulmonary vascular leakage and lung injury. CONCLUSIONS: EMPs and PMPs contribute to the pulmonary vascular leakage and lung injury after I/R. EMPs mediate pulmonary sequestration of platelets, producing more PMPs to play synergistic effect. Mechanically, EMPs carrying miR-155 that down-regulates ZO-1 and claudin-5 and PMPs carrying miR-126 that up-regulates Cav-1, synergistically mediate pulmonary vascular leakage and lung injury after I/R. Video Abstract.

Drp1 regulates mitochondrial dysfunction and dysregulated metabolism in ischemic injury via Clec16a-, BAX-, and GSH- pathways.

The adaptation of mitochondrial homeostasis to ischemic injury is not fully understood. Here, we studied the role of dynamin-related protein 1 (Drp1) in this process. We found that mitochondrial morphology was altered in the early stage of ischemic injury while mitochondrial dysfunction occurred in the late stage of ischemia. Drp1 appeared to inhibit mitophagy by upregulating mito-Clec16a, which suppressed mito-Parkin recruitment and subsequently impaired the formation of autophagosomes in vascular tissues after ischemic injury. Moreover, ischemia-induced Drp1 activation enhanced apoptosis through inducing mitochondrial translocation of BAX and thereby increasing release of Cytochrome C to activate caspase-3/-9 signalling. Furthermore, Drp1 mediated metabolic disorders and inhibited the levels of mitochondrial glutathione to impair free radical scavenging, leading to further increases in ROS and the exacerbation of mitochondrial dysfunction after ischemic injury. Together, our data suggest a critical role for Drp1 in ischemic injury.

Research advances in pericyte function and their roles in diseases.

Pericyte, a kind of pluripotent cell, may regulate the irrigation flow and permeability of microcirculation. Pericytes are similar to the smooth muscle cells, which express several kinds of contractile proteins and have contractility. The dysfunction of pericytes is related to many microvascular diseases, including hypoxia, hypertension, diabetic retinopathy, fibrosis, inflammation, Alzheimer's disease, multiple sclerosis, and tumor formation. For a long time, their existence and function have been neglected. The distribution, structure, biomarker, related signaling pathways as well as the roles of pericytes on vascular diseases will be introduced in this review.

Role of Tumor Necrosis Factor-α in vascular hyporeactivity following endotoxic shock and its mechanism.

BACKGROUND: Vascular hyporeactivity plays an important role in organ dysfunction induced by endotoxic shock. Given that cytokine, such as TNF-α, plays an important role in endotoxic shock, the aim of the present study is to investigate the role of Tumor Necrosis Factor (TNF)-α in vascular hyporeactivity following endotoxic shock and the mechanisms. METHODS: Lipopolysaccharide (LPS) (1 mg/kg) injection was used for replicating the endotoxic shock model in the rabbit. The changes in the level of TNF-α in plasma in the rabbits model and the contractile response of superior mesenteric arteries (SMA) to norepinephrine (NE) and Ca were observed. The mechanisms in TNF-α-induced vascular hyporeactivity were further explored. RESULTS: The levels of TNF-α in plasma were gradually increased after 1 hour of LPS administration and reached the peak at 6 hours. The contractile responses of SMA to NE were decreased at 1 hour of LPS and lowest at 6 hour. TNF-α (200 ng/mL) incubation decreased contractile response of SMA to NE significantly. Further studies found that calcium desensitization participated in the occurrence of TNF-α-induced vascular hyporeactivity, the changes were consistent with the changes of vascular reactivity, calcium sensitivities were decreased significantly at 1 hour, 2 hours, 4 hours, and 6 hours after LPS injection. TNF-α (200 ng/mL) incubation could significantly reduce the contractile response of SMA to Ca. The activity of Rho-kinase and the changes of myosin light chain 20 (MLC20) phosphorylation level were significantly decreased at 6 hours following LPS administration, and TNF-α (200 ng/mL) incubation led to a decrease of Rho-kinase and MLC20 phosphorylation. Arginine vasopressin significantly antagonized TNF-α (200 ng/mL)-induced the decrease of the vascular reactivity and calcium sensitivity. CONCLUSION: TNF-α is involved in vascular hyporeactivity after endotoxic shock. Calcium desensitization plays an important role in TNF-α-induced vascular hyporeactivity after endotoxic shock. Rho-kinase/MLC20 phosphorylation pathway takes part in the regulation of calcium desensitization and vascular hyporeactivity induced by TNF-α. Arginine vasopressin is beneficial to endotoxic shock in TNF-α-induced vascular hyporeactivity.

Role of resveratrol in protecting vasodilatation function in septic shock rats and its mechanism.

BACKGROUND: Vascular dysfunction is a major cause of sepsis-induced multiple-organ dysfunction. Resveratrol is a polyphenol compound with extensive pharmacological effects including anti-inflammation. The aim of this study was to determine the role and mechanism of resveratrol in protecting vascular function following sepsis. METHODS: The cecal ligation and puncture method was used to establish a septic shock rat model. Resveratrol (5 mg/kg and 10 mg/kg) was administered intravenously immediately and at 12 hours after cecal ligation and puncture, respectively. The effects of resveratrol on vasodilatation function, blood flow velocity, hemodynamics, and vital organ function and its relationship to Rac-1 and HIF-1α were observed. RESULTS: Vascular relaxation reactivity and blood flow velocity were significantly decreased after septic shock, both were significantly improved by resveratrol 5 mg/kg and 10 mg/kg, and the effect of 10 mg/kg was greater. The relaxation reactivity of the superior mesenteric artery to acetylcholine (Ach) was increased by 43.2%. The blood flow velocity of mesenteric arterioles and venules was increased by 47.1% and 51%, respectively, after resveratrol (10 mg/kg) administration compared with the septic shock group. The hemodynamics and both liver and kidney blood flow were significantly decreased after septic shock, which were significantly improved them by resveratrol, which enhanced the vascular relaxation reactivity in septic shock rats. The 72-hour survival rate of septic shock rats in the resveratrol group (62.5%) was significantly higher than that in the septic shock group (6.3%). Resveratrol significantly upregulated the expression of endothelial nitric oxide synthase (eNOS) and downregulated the expression of inducible NOS, Rac-1, and HIF-1α. Inhibitors of Rac-1 and HIF-1α significantly improved the expression of eNOS, and inhibition of eNOS (L-NAME, 5 mg/kg) antagonized the resveratrol-induced improvement in vascular relaxation reactivity and survival. CONCLUSION: Resveratrol was beneficial for vasodilatation function in rats with septic shock, which is the major contribution to resveratrol improving hemodynamics and organ perfusion. The mechanism involved resveratrol upregulating the expression of eNOS by inhibiting Rac-1 and HIF-1α.

Urotensin II: an inflammatory cytokine.

Urotensin II (UII) is a polypeptide molecule with neurohormone-like activity. It has been confirmed that UII is widely distributed in numerous organs of different animal species from fish to mammals, including humans. The UII receptor is orphan G-protein coupled receptor 14, also known as UT. The tissue distribution of UII and UT is highly consistent, and their expression may be regulated by autocrine and paracrine mechanisms. In the body, UII has many physiological and pathophysiological activities, such as vasoconstrictor and vasodilatory actions, cell proliferation, pro-fibrosis, neuroendocrine activity, insulin resistance, and carcinogenic and inflammatory effects, which have been recognized only in recent years. In fact, UII is involved in the process of inflammatory injury and plays a key role in the onset and development of inflammatory diseases. In this paper, we will review the roles UII plays in inflammatory diseases.

miRNA-mRNA crosstalk in myocardial ischemia induced by calcified aortic valve stenosis.

Aortic valve stenosis is the most common cause of morbidity and mortality in valvular heart disease in aged people. Both microRNA (miRNA) and mRNA are potential targets for the diagnosis and therapeutic intervention of myocardial ischemia induced by calcified aortic valve stenosis (CAVS), with unclear mechanisms. Here, 3 gene expression profiles of 47 male participants were applied to generate shared differentially expressed genes (DEGs) with significant major biological functions. Moreover, 20 hub genes were generated by a Weighted Genes Co-Expression Network Analysis (WGCNA) and were cross-linked to miRNA based on miRanda/miRwalk2 databases. Integrated miRNA/mRNA analysis identified several novel miRNAs and targeted genes as diagnostic/prognostic biomarkers or therapeutic targets in CAVS patients. In addition, the clinical data suggested that myocardial hypertrophy and myocardial ischemia in CAVS patients are likely associated with hub genes and the upstream regulatory miRNAs. Together, our data provide evidence that miRNAs and their targeted genes play an important role in the pathogenesis of myocardial hypertrophy and ischemia in patients with CAVS.

Organ-specific changes in vascular reactivity and roles of inducible nitric oxide synthase and endothelin-1 in a rabbit endotoxic shock model.

BACKGROUND: Hemorrhagic shock-induced changes in vascular reactivity appear organ-specific. In the present study, we examined the hypothesis that vascular reactivity induced by septic shock similarly displays organ-specific differences and is regulated by inducible nitric oxide synthase (iNOS) and endothelin-1 (ET-1). METHODS: Endotoxic shock was induced in rabbits by administration of lipopolysaccharide (LPS) (1 mg/kg), and organ specificity of vascular reactivity of superior mesenteric artery (SMA), celiac artery (CA), and left renal artery (LRA) as well as the potential involvement of iNOS and ET-1 examined. RESULTS: Vascular reactivity of SMA, CA, and LRA was increased at the early stages and decreased at the late stages after LPS administration. Superior mesenteric artery showed the greatest decrease in vascular reactivity in response to norepinephrine (NE) (34.9%) and acetylcholine (Ach; 32.3%), followed by LRA (NE, 33.7%; Ach, 30.5%) and CA (NE, 16.2%), whereas the relaxation reactivity of CA in response to Ach was increased to 159%. The mRNA and protein levels of iNOS and ET-1 in SMA, CA, and LRA were not affected at the early stages of endotoxic shock after LPS administration but significantly increased at the late stages. Expression levels were higher in SMA than CA and LRA and negatively correlated with the decrease in vascular reactivity. The iNOS and ET-1 inhibitors, aminoguanidine (20 mg/kg) and PD-142893 (0.02 mg/kg), respectively, induced significant improvements in vascular reactivity and organ perfusion and stabilized the hemodynamic parameters in rabbits subjected to endotoxic shock. CONCLUSION: Changes in vascular reactivity during endotoxic shock are organ-specific. Differential expression patterns of iNOS and ET-1 in different blood vessels contribute to the organ specificity of vascular reactivity. LEVEL OF EVIDENCE: Therapeutic study, level II.

GTSF1 gene may serve as a novel potential diagnostic biomarker for liver cancer.

The gametocyte-specific factor 1 (GTSF1) gene participates in DNA methylation and retrotransposon activation in germ cells, particularly during cell proliferation. The present study aimed to assess the level of GTSF1 gene expression in liver cancer tumor tissues, and its role in human hepatoma cell lines in vitro and in a nude mouse model in vivo. GTSF1 gene expression was detected in liver cancer tumor tissues, compared with in healthy controls, via reverse transcription quantitative polymerase chain reaction. An adeno-associated virus vector was used to study tumor stem cell proliferation in vivo. A plasmid expressing GTSF1 was constructed and transfected into various human hepatoma cell lines, in order to analyze the cellular proliferation and apoptosis of liver cancer cells using small interfering (si)RNAs in vitro. In the present study, GTSF1 gene expression was detected in 18/24 (75.0%) liver cancer tumor tissues from patients with hepatocellular carcinoma (HCC), and elevated GTSF1 expression was identified in the tissue of one of 32 healthy control samples (3.13%; P<0.05). Notably, the GTSF1 gene was expressed at a higher frequency in AFP-positive HCC samples (14/16, 87.50%) compared with in AFP-negative HCC samples (4/8, 50.0%; P=0.129). In addition, there was no statistical significance between GTSF1 expression in non-HBV-infected (71.42%) and HBV-infected HCC specimens (76.47%), as determined by a χ2 test (P=0.921). It was demonstrated that GTSF1 significantly increased the tumorigenicity of Ad-shNC-transfected (GTSF1-positive) HepG2 cells in the nude mouse xenograft model, whereas the sizes and weights of the tumors in the GTSF1-negative group were dercreased in comparison with the GTSF1-positive group (P<0.05). Reduced levels of GTSF1 mRNA, along with fewer and smaller colonies, were identified in two groups of human liver cancer cells treated with with GTSF1-targeting siRNA, when compared with cells without GTSF1 mRNA interference (P<0.05). In summary, the present study elucidated the GTSF1 mRNA expression pattern in liver cancer, and investigated the potential role of GTSF1 in tumorigenesis. The data suggest an important role for the GTSF1 gene in the molecular etiology of hepatocarcinogenesis, and indicate a potential application of GTSF1 mRNA expression in liver cancer diagnosis and therapy.

Myoendothelial gap junctions mediate regulation of angiopoietin-2-induced vascular hyporeactivity after hypoxia through connexin 43-gated cAMP transfer.

Angiopoietin-2 (Ang-2) contributes to vascular hyporeactivity after hemorrhagic shock and hypoxia through upregulation of inducible nitric oxide synthase (iNOS) in a vascular endothelial cell (VEC)-specific and Ang-2/Tie2 receptor-dependent manner. While iNOS is primarily expressed in vascular smooth muscle cells (VSMCs), the mechanisms of signal transfer from VECs to VSMCs are unknown. A double-sided coculture model with VECs and VSMCs from Sprague-Dawley rats was used to investigate the role of myoendothelial gap junctions (MEGJs), the connexin (Cx) isoforms involved, and other relevant mechanisms. After hypoxia, VSMCs treated with exogenous Ang-2 showed increased iNOS expression and hyporeactivity, as well as MEGJ formation and communication. These Ang-2 effects were suppressed by the MEGJ inhibitor 18α-glycyrrhetic acid (18-GA), Tie2 siRNA, or Cx43 siRNA. Reagents antagonizing cAMP or protein kinase A (PKA) in VECs inhibited Cx43 expression in MEGJs, decreasing MEGJ formation and associated communication, after hypoxia following Ang-2 treatment. The increased cAMP levels in VSMCs and transfer of Alexa Fluor 488-labeled cAMP from VECs to VSMCs, after hypoxia following Ang-2 treatment, was antagonized by Cx43 siRNA. A cAMP antagonist added to VECs or VSMCs inhibited both increased iNOS expression and hyporeactivity in VSMCs subjected to hypoxia following Ang-2 treatment. Based on these findings, we propose that Cx43 was the Cx isoform involved in MEGJ-mediated VEC-dependent regulation of Ang-2, which induces iNOS protein expression and vascular hyporeactivity after hypoxia. Cx43 was upregulated by cAMP and PKA, permitting cAMP transfer between cells.