Clusterin attenuates blood-brain barrier damage and cognitive impairment by inhibiting astrocyte aging in mice with sepsis-associated encephalopathy.

Sepsis-associated encephalopathy (SAE) is a severe complication of sepsis, however, its exact mechanism remains unknown. This study aimed to evaluate whether clusterin is essential to the development of SAE during the aging process of astrocytes. In the study, septic mice were established with cecal ligation and puncture (CLP) and lipopolysaccharides were applied to astrocytes in vitro. Evan's blue dye was used in vivo to show blood-brain barrier (BBB) permeability. A morris water maze test was conducted to assess cognitive functions of the mice. Clusterin-knockout mice were used to examine the effect of clusterin on sepsis. The astrocytes were transfected with lentivirus expressing clusterin cDNA for clusterin overexpression or pYr-LV-clusterin small hairpin RNA for clusterin knockdown in vitro . The expression of clusterin, p-p53, p21, GDNF, and iNOS was detected. he CLP mice exhibited a higher clusterin expression in hippocampus tissue, aging astrocytes, lower GDNF expression and higher iNOS expression, accompanied with BBB damage and cognitive deficiency. Following clusterin knockout, this pathological process was further enhanced. In vitro , following lipopolysaccharides treatment, astrocytes exhibited increased clusterin, p-p53, p21, iNOS and decreased GDNF. Following clusterin knockdown, the cells exhibited a further increase in p-p53, p21, and iNOS and decrease in GDNF. Clusterin overexpression, however, helped inhibit astrocytes aging and neuroinflammation evidenced by decreased p-p53, p21, iNOS and increased GDNF. The present study has revealed that clusterin may exert its neuroprotective effect by preventing aging in astrocytes, suppressing the secretion of iNOS and promoting GNDF release.

Hyperglycemia induces microglial pyroptosis by increasing oxygen extraction rate: Implication in neurological impairment during ischemic stroke.

Elevated levels of blood glucose in patients with ischemic stroke are associated with a worse prognosis. The present study aimed to explore whether hyperglycemia promotes microglial pyroptosis by increasing the oxygen extraction rate in an acute ischemic stroke model. C57BL/6 mice that underwent middle cerebral artery occlusion were used for assessment of blood glucose level and neurological function. The cerebral oxygen extraction ratio (CERO2), oxygen consumption rate (OCR) and partial pressure of brain tissue oxygen (PbtO2) were measured. To investigate the significance of the NOD­like receptor protein 3 (NLRP3) inflammasome, NLRP3­/­ mice were used, and the expression levels of NLRP3, caspase­1, full­length gasdermin D (GSDMD­FL), GSDMD­N domain (GSDMD­N), IL­1ß and IL­18 were evaluated. In addition, Z­YVAD­FMK, a caspase­1 inhibitor, was used to treat microglia to determine whether activation of the NLRP3 inflammasome was required for the enhancing effect of hyperglycemia on pyroptosis. It was revealed that hyperglycemia accelerated cerebral injury in the acute ischemic stroke model, as evidenced by decreased latency to fall and the percentage of foot fault. Hyperglycemia aggravated hypoxia by increasing the oxygen extraction rate, as evidenced by increased CERO2 and OCR, and decreased PbtO2 in response to high glucose treatment. Furthermore, hyperglycemia­induced microglial pyroptosis was confirmed by detection of increased levels of caspase­1, GSDMD­N, IL­1ß and IL­18 and a decreased level of GSDMD­FL. However, the knockout of NLRP3 attenuated these effects. Pharmacological inhibition of caspase­1 also reduced the expression levels of GSDMD­N, IL­1ß and IL­18 in microglial cells. These results suggested that hyperglycemia stimulated NLRP3 inflammasome activation by increasing the oxygen extraction rate, thus leading to the aggravation of pyroptosis following ischemic stroke.

Pyruvate dehydrogenase complex deficiency masked by septic shock-induced lactic acidosis: a case report.

Pyruvate dehydrogenase complex (PDHC) deficiency is a common genetic disorder leading to lactic acidosis, which can also result from several nongenetic conditions, such as septic shock. The present study reports a case of PDHC deficiency masked by septic shock-induced lactic acidosis. This case involved a 16-year-old adolescent with poor exercise tolerance compared with his peers, and no underlying diseases. The disease onset was characterized by cough, fever, and dyspnea, with hypotension and elevated lactate levels, which indicated septic shock. However, severe hypoglycemia and lactic acidosis persisted despite resolution of a pulmonary infection and correction of septic shock, requiring continuous intravenous infusion of 50% glucose. Although the patient did not experience acute kidney injury and had normal urine output, continuous renal replacement therapy was used to regulate the internal environment owing to the severity of the acidosis. The diagnosis of PDHC deficiency was considered on the basis of the persistent hypoglycemia and hyperlactatemia, before genetic mutation testing was completed. The clinical thinking process required a rich accumulation of pathophysiological knowledge. This article reports a case of PDHC deficiency masked by septic shock-induced lactic acidosis to raise awareness of the disease and avoid misdiagnosis and missed diagnosis.

Heat stress induces IL-1ß and IL-18 overproduction via ROS-activated NLRP3 inflammasome: implication in neuroinflammation in mice with heat stroke.

Heat stroke induced cerebral damage via neuroinflammation. This study aimed to approach whether heat stress would promote NOD-like receptor protein 3 (NLRP3) inflammasome via reactive oxygen species (ROS). The mice were randomly divided into the sham group, the heat stress group, and the heat stress + TEMPOL (ROS scavenger) group. And the NLRP3 -/- mice were applied and divided into the NLRP3 -/-  + sham group and the NLRP3 -/-  + heat stress group. Furthermore, the BV2 cells were divided into four groups following the intervention measures: the heat stress + TEMPOL group, the heat stress + Z-VAD-FMK (caspase-1 inhibitor) group, the heat stress group, and the control group. ROS levels were examined. The expression levels of NLRP3, caspase-1, IL-1ß, and IL-18 were detected by western blotting and double immunofluorescence. We found that heat stress attack induced excessive ROS in microglia and subsequently activated NLRP3 inflammasome in both mice and BV2 cells. When ROS scavenged, the expression level of NLRP3 was downregulated. Furthermore, with NLRP3 inflammasome activation, the expression levels of caspase-1, IL-1ß, and IL-18 were increased. In NLRP3 -/- mice, however, the caspase-1, IL-1ß, and IL-18 were significantly declined. Further experiments showed that pretreatment of caspase-1 inhibitor decreased the expression levels of IL-1ß and IL-18. These results suggest that heat stress attack caused neuroinflammation via excessive ROS activating the NLRP3 inflammasome in microglia cells.

Bacterial DNA metabolism analysis by metagenomic next-generation sequencing (mNGS) after treatment of bloodstream infection.

BACKGROUND: With the advent of metagenomic next-generation sequencing (mNGS), the time of DNA metabolism can be explored after bacteria be killed. In this study, we applied mNGS in investigation of the clearance profile of circulating bacteria DNA. METHODS: All of the rabbits were injected with the inactivated Escherichia coli. Using mNGS, we analyzed serial samples of plasma collected from rabbits to detect clearance profile of circulating E. coli DNA. RESULTS: In this study, we found that the of E. coli DNA could still be detected 6 h after injecting killed bacteria. The clearance half-lives associated with the 2 phases are 0.37 and 1.81 h. We also explored there is no correlation between the disease severity with the E. coli DNA reads in circulation. CONCLUSIONS: After the bacteria were completely killed, their DNA could still be detected in the blood circulation. The metabolism of bacterial DNA in the circulation had two phases: fast and slow phases, and there were no correlations between the level of bacteria reads with the severity of patients' disease after the bacteria have been completely killed.

[Predictive value of sepsis-induced coagulopathy score on 30-day mortality in septic patients].

OBJECTIVE: To evaluate the predictive effect of sepsis-induced coagulopathy (SIC) score level on the prognosis of septic patients under sepsis 3.0 criteria. METHODS: A retrospective single-center observational study was conducted on the septic patients admitted to the department of critical care medicine and the department of emergency in Guangdong Provincial People's Hospital from August 2016 to July 2021. The baseline data, laboratory indexes and SIC scores of the patients were collected on the first and fourth (4th) day after hospitalization. Whether the patients were survival within 30 days after enrollment was recorded. Univariate and multivariate Logistic regression were used to analyze the independent risk factors for 30-day mortality in septic patients. The receiver operator characteristic curve (ROC curve) was drawn to evaluate the predictive value of SIC score on the 30-day prognosis of septic patients. RESULTS: A total of 173 patients met the inclusion criteria including 111 (64%) survivors and 62 (36%) non-survivors. There were significant differences in lymphocyte count (LYM), sequential organ failure assessment (SOFA), oxygenation index (PaO2/FiO2) and cardiovascular SOFA score between the survival group and the non-survival group. And there were no significant differences in other indexes. On the first day of admission, there were statistically significant differences in PaO2/FiO2, cardiovascular SOFA score, LYM, SIC score between the non-survival group and the survival group. There were significant differences in international normalized ratio (INR), prothrombin activity (PTA), prothrombin time (PT), PaO2/FiO2, cardiovascular SOFA score, LYM, C-reactive protein (CRP) and procalcitonin (PCT) between the two groups on the 4th day after admission. The mortality of septic patients increased with the increase of SIC score. Binary Logistic regression analysis showed that SIC score and LYM on the 4th day after admission were independent risk factors for 30-day mortality in septic patients (both P < 0.05). The ROC curve showed that SIC score had a certain predictive value for the 30-day prognosis of septic patients [area under the ROC curve (AUC) = 0.712, 95% confidence interval (95%CI) was 0.629-0.794, P < 0.001]. The predictive value of SIC score combined with LYM was better than that of the two alone (AUC = 0.748, 95%CI was 0.688-0.828, P < 0.001). CONCLUSIONS: The SIC score has a certain predictive value for the 30-day prognosis of septic patients. The predictive value of SIC score combined with LYM is better than that of the two alone, which is expected to be a potential indicator for early assessment of the condition and prognosis of septic patients.

Human albumin aggravates cerebral edema by disrupting the blood­brain barrier in a rat model of ischemic stroke.

Cerebral edema and elevated intracranial pressure (ICP) are common complications observed following ischemic stroke. Osmotherapy has been used as a foundation to manage ICP induced by cerebral edema, and albumin is one of the most commonly used osmotic agents. The present study aimed to explore whether albumin lowered ICP by reducing cerebral edema when albumin elevated the colloid osmotic pressure (COP) of plasma. Sprague­Dawley rats that underwent middle cerebral artery occlusion were used to assess COP and ICP. Magnetic resonance imaging measurements were performed to evaluate cerebral edema and infarct size. Evans blue was used to assess the blood­brain barrier (BBB) permeability. Western blotting was used to determine the expression levels of the tight junction proteins in cerebral vascular endothelial cells. The results showed that 25% albumin treatment (1.25 g/kg) by intravenous injection elevated the COP of plasma but did not reduce the ICP in rats that had undergone ischemic stroke. Additionally, albumin did not reduce the infarct size and instead aggravated cerebral edema. Furthermore, the BBB permeability was increased by albumin. Concomitantly, albumin treatment significantly downregulated the expression of tight junction proteins (ZO­1, occludin, and claudin­5) in cerebral vascular endothelial cells. Tight junction protein expression was significantly upregulated when the cells were treated with an MMP­9 inhibitor (GM6001). These results suggest that albumin aggravates cerebral edema in rats with ischemic stroke by increasing BBB permeability.

Bradykinin/bradykinin 1 receptor promotes brain microvascular endothelial cell permeability and proinflammatory cytokine release by downregulating Wnt3a.

Stroke is a life-threatening disease with limited therapeutic options. Damage to the blood-brain barrier (BBB) is the key pathological feature of ischemic stroke. This study explored the role of the bradykinin (BK)/bradykinin 1 receptor (B1R) and its mechanism of action in the BBB. Human brain microvascular endothelial cells (BMECs) were used to test for cellular responses to BK by using the Cell Counting Kit-8 assay, 5-ethynyl-2'-deoxyuridine staining, enzyme-linked immunosorbent assay, flow cytometry, immunofluorescence, cellular permeability assays, and western blotting to evaluate cell viability, cytokine production, and reactive oxygen species (ROS) levels in vitro. A BBB induced by middle cerebral artery occlusion was used to evaluate BBB injuries, and the role played by BK/B1R in ischemic/reperfusion (I/R) was explored in a rat model. Results showed that BK reduced the viability of BMECs and increased the levels of proinflammatory cytokines (interleukin 6 [IL-6], IL-18, and monocyte chemoattractant protein-1) and ROS. Additionally, cellular permeability was increased by BK treatment, and the expression of tight junction proteins (claudin-5 and occludin) was decreased. Interestingly, Wnt3a expression was inhibited by BK and exogenous Wnt3a restored the effects of BK on BMECs. In an in vivo I/R rat model, knockdown of B1R significantly decreased infarct volume and inflammation in I/R rats. Our results suggest that BK might be a key inducer of BBB injury and B1R knockdown might provide a beneficial effect by upregulating Wnt3a.

Association between the LRP5 rs556442 gene polymorphism and the risks of NAFLD and CHD in a Chinese Han population.

BACKGROUND: Multiple studies have demonstrated the involvement of low-density lipoprotein receptor-related protein 5 (LRP5) in metabolism-related diseases. This study explored the relationship between the LRP5 rs556442 gene polymorphism and the risks of non-alcoholic fatty liver disease (NAFLD) and coronary heart disease (CHD) in a Chinese Han population. METHODS: This retrospective case-control study included 247 patients with NAFLD, 200 patients with CHD, 118 patients with both NAFLD and CHD, and 339 healthy controls from June 2018 to June 2019 at Qingdao Municipal Hospital. Basic information and clinical characteristics were collected for all subjects. The genotype and allele frequency of LRP5 rs556442 were determined. RESULTS: The genotype distributions of LRP5 rs556442 differed significantly between the CHD and NAFLD + CHD groups (P < 0.05). The LRP5 rs556442 GG genotype markedly promoted the risk of NAFLD in CHD patients [odds ratio (OR) = 2.857, 95% confidence interval (CI): 1.196-6.824, P = 0.018). After adjustment for sex, age, and body mass index (BMI), this association remained significant (OR = 3.252, 95% CI: 1.306-8.102, P = 0.011). In addition, the LRP5 rs556442 AA + AG genotype was associated with an increased BMI in obese NAFLD patients (OR = 1.526, 95% CI: 1.004-2.319, P = 0.048). However, after adjustment for sex and age, this association was no longer significant (OR = 1.504, 95% CI: 0.991-2.282, P = 0.055). CONCLUSIONS: This study found that the LRP5 rs556442 GG genotype increased the risk of NAFLD in CHD patients and AA + AG genotype may be associated with an increased BMI in obese NAFLD patients among a Chinese Han population. Trial registration ChiCTR, ChiCTR1800015426. Registered 28 March 2018-Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=26239 .

Exosome-Derived lncRNA NEAT1 Exacerbates Sepsis-Associated Encephalopathy by Promoting Ferroptosis Through Regulating miR-9-5p/TFRC and GOT1 Axis.

Sepsis can cause sepsis-associated encephalopathy (SAE), but whether SAE was induced or exacerbated by ferroptosis remains unknown. In this study, the rat sepsis model was constructed using the cecal ligation and puncture method. The blood-brain barrier (BBB) permeability was measured by Evans blue dye (EBD) in vivo. The levels of ROS, Fe ion, MDA, GSH, and GPX4 were assessed by enzyme-linked immunosorbent assay (ELISA). The exosomes isolated from serum were cultured with bEnd.3 cells for the in vitro analysis. Moreover, bEnd.3 cells cultured with 100 µM FeCl3 (iron-rich) were to simulate ferroptosis stress. The cell viability was evaluated by Cell Counting Kit-8 (CCK-8) assay. A dual-luciferase reporter gene assay was performed to confirm the relationship between miR-9-5p with NEAT1, TFRC, and GOT1. In vivo, it is found that BBB permeability was damaged in model rats. Level of ROS, Fe ion, and MDA was increased, and level of GSH and GPX4 was decreased, which means ferroptosis was induced by sepsis. Exosome-packaged NEAT1 in serum was significantly upregulated in model rats. In vitro, it is found that NEAT1 functions as a ceRNA for miR-9-5p to facilitate TFRC and GOT1 expression. Overexpression of NEAT1 enhanced ferroptosis stress in bEnd.3 cells. Increased miR-9-5p alleviated sepsis-induced ferroptosis by suppressing the expression of TFRC and GOT1 both in vivo and in vitro. In conclusion, these findings suggest that sepsis induced high expression of serous exosome-derived NEAT1, and it might exacerbate SAE by promoting ferroptosis through regulating miR-9-5p/TFRC and GOT1 axis.

Fisetin ameliorates cognitive impairment by activating mitophagy and suppressing neuroinflammation in rats with sepsis-associated encephalopathy.

BACKGROUND: Fisetin, the effective ingredient of the traditional Chinese medicine named Cotinus coggygria, is recommended to be active therapeutic in many disorders. However, its role in sepsis-associated encephalopathy (SAE) remains unclarified. METHODS: Cecal ligation and puncture (CLP) operation was performed to establish a rat model of SAE. Rats were grouped according to the surgery operation and fisetin administration. Cognitive impairment was assessed by Morris water maze test. Disruption of blood-brain barrier (BBB) integrity was detected by Evan's blue staining. The mitophagy, reactive oxygen species (ROS) generation, NLRP3 inflammasome activation, and pro-inflammatory cytokines levels were measured through western blot and double immunofluorescence labeling. A transmission electron microscope was applied for the observation of mitochondrial autophagosomes. RESULTS: Rats in the CLP group presented increased expression of IL-1R1, pNF-κB, TNF-α, and iNOS in microglial cells, indicating severe inflammation in the central nervous system (CNS). Nevertheless, there was no increase in BBB permeability. Meanwhile, NLRP3 inflammasome was activated in cerebral microvascular endothelial cells (CMECs), presented with an elevation of caspase-1 expression and IL-1ß secretion into CNS. In addition, we found fisetin significantly improved cognitive dysfunction in rats with SAE. Neuroprotective effects of fisetin might be associated with inhibition of neuroinflammation, represented with decreased expression of IL-1R1, pNF-κB, TNF-α, and iNOS in microglia. Furthermore, fisetin induced mitophagy, scavenged ROS, blocked NLRP3 inflammasome activation of CMECs, as evidenced by decreased expression of caspase-1 and reduced release of IL-1ß into CNS. CONCLUSION: Collectively, fisetin-blocked NLRP3 inflammasome activation via promoting mitophagy in CMECs may suppress the secretion of IL-1ß into CNS, reduce neuroinflammation, and contribute to the amelioration of cognitive impairment.

Elevated intracranial pressure induces IL­1ß and IL­18 overproduction via activation of the NLRP3 inflammasome in microglia of ischemic adult rats.

Elevated intracranial pressure (ICP) is one of the most common complications following an ischemic stroke, and has implications for the clinical and neurological outcomes. The aim of the present study was to examine whether elevated ICP may increase IL­1ß and IL­18 secretion by activating the NOD­like receptor protein 3 (NLRP3) inflammasome in microglia of ischemic adult rats. Sprague­Dawley rats that underwent middle cerebral artery occlusion were used for assessment of ICP. Reactive oxygen species (ROS) production was detected, and western blotting and immunofluorescence staining were used to determine the expression levels of Caspase­1, gasdermin D­N domains (GSDMD­N), IL­1ß and IL­18 in microglial cells. ICP levels were significantly increased, which was accompanied by ROS overproduction, in the brain tissue following ischemia­reperfusion (IR) injury in rats. Treatment with 10% hypertonic saline by intravenous injection significantly reduced the ICP and ROS levels of the rats. Furthermore, high pressure (20 mmHg) combined with oxygen­glucose deprivation (OGD) treatment resulted in increased ROS production in BV­2 microglial cells compared with those subjected to OGD treatment alone in vitro. Elevated pressure upregulated the expression of Caspase­1, GSDMD­N, IL­18 and IL­1ß in IR­treated or OGD­treated microglia both in vivo and in vitro. More importantly, Caspase­1, GSDMD­N, IL­18 and IL­1ß expression in microglia was significantly downregulated when elevated pressure was reduced or removed. These results suggested that elevated ICP­induced IL­1ß and IL­18 overproduction via activation of the NLRP3 inflammasome by ischemia­activated microglia may augment neuroinflammation.

JAK/STAT signaling pathway-mediated microRNA-181b promoted blood-brain barrier impairment by targeting sphingosine-1-phosphate receptor 1 in septic rats.

BACKGROUND: Blood-brain barrier (BBB) impairment plays a significant role in the pathogenesis of sepsis-associated encephalopathy (SAE). However, the molecular mechanisms are poorly understood. In the present study, we aimed to investigate the regulatory relationship between the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway, microRNA (miR)-181b and its target genes in sepsis in vivo and in vitro. METHODS: Four rat models (sham, sepsis, sepsis plus STAT3 inhibitor (Stattic), and sepsis plus miR-181b inhibitor [sepsis + anta-miR-181b]) were established. For the in vitro experiments, rat brain microvascular endothelial cells (rBMECs) and rat brain astrocytes (rAstrocytes) were cultured with 10% serum harvested from sham, sepsis, and sepsis + anta-miR-181b rats. Chromatin immunoprecipitation-quantitative polymerase chain reaction (ChIP-QPCR) analysis was carried out to detect the binding and enrichment of the JAK/STAT3 signal core transcription complex in the miR-181b promoter region. Dual-luciferase reporter gene assay was conducted to test miR-181b and its target genes. The cell adhesion rate of rBMECs was also measured. RESULTS: During our investigations, the expression levels of miR-181b, p-JAK2, p-STAT3, and C/EBPß were found to be significantly increased in the septic rats compared with the sham rats. STAT3 inhibitor halted BBB damage by downregulating the expression of miR-181b. In addition, miR-181b targeted sphingosine-1-phosphate receptor 1 (S1PR1) and neurocalcin delta (NCALD). The up-regulated miR-181b significantly decreased the cell adhesion rate of rBMECs. The administration of miR-181b inhibitor reduced damage to the BBB through increasing the expression of S1PR1 and NCALD, which again proved that miR-181b negatively regulates SIPR1 and NCALD to induce BBB damage. CONCLUSIONS: Our study demonstrated that JAK2/STAT3 signaling pathway induced expression of miR-181b, which promoted BBB impairment in rats with sepsis by downregulating S1PR1 and decreasing BBB cell adhesion. These findings strongly suggest JAK2/STAT3/miR-181b axis as therapeutic target in protecting against sepsis-induced BBB damage.

PD-1 in Tregs predicts the survival in sepsis patients using sepsis-3 criteria: A prospective, two-stage study.

BACKGROUND: The expression of Tregs co-signaling molecules serves as the marker of immune dysfunction. The present study aimed to verify their predictive role in the 28-day mortality of sepsis patients. METHODS: A prospective, observational, two-stage cohort study was conducted. The patients who fulfilled the sepsis-3 criteria were enrolled, and peripheral blood samples were collected within 24 h post-enrollment. The expression of the four co-signaling molecules of Tregs, namely, PD-1, CD28, PD-L1 and CD86, was measured, and sequential organ failure assessment (SOFA) scores were recorded on day 1 of inclusion. Patients were followed up for 28 days or, otherwise, deceased. Multivariate regression analysis was used to assess the independent risk factors for 28-day mortality, and a prognostic prediction model was established, which was verified in the validation set. RESULTS: A total of 292 patients were recruited in the study, of which 120 patients were finally included in the analysis, that is 58 patients in stage I (test set) and 62 patients in stage II (validation set). In stage I, 14 (24.1%), patients died during 28 days, and the expression of PD-1 in Tregs (OR:1.037;95%CI:1.003-1.071) and SOFA scores(OR:1.262;95%CI:1.046-1.524) were independent risk factors for 28-day mortality. The ability of Tregs PD-1 in predicting 28-day mortality was validated in stage II (AUC = 0.792). CONCLUSION: PD-1 overexpression in Tregs was associated with poor outcomes, and PD-1 in Tregs is considered to be a valuable tool for the prediction of prognosis in septic patients using sepsis-3.0 criteria.

[Mechanism of resveratrol on ameliorating the cognitive dysfunction induced by sepsis associated encephalopathy in rats].

OBJECTIVE: To explore the mechanism of resveratrol on ameliorating the cognitive dysfunction induced by sepsis associated encephalopathy (SAE) in rats. METHODS: The 12 weeks old male Sprague-dawley (SD) male rats were randomly divided into sham group, sepsis group and resveratrol group, with 30 rats in each group. The rat model of sepsis was made by injecting LPS (10 mg/kg) into tail vein. The rats in sham group was given the same amount of normal saline (NS). After LPS injection, resveratrol (8 mg×kg-1×d-1) was intraperitoneally injected once daily for 2 days in the resveratrol group; the same amount of NS was given to the sepsis group and sham group. At 24 hours after model establishment, the cognitive function of the experimental rats was assessed by the Morris water maze test. The blood-brain barrier (BBB) permeability was evaluated by the brain water content (BWC) and Evans blue (EB) test. The protein expressions of matrix metalloproteinase 9 (MMP-9), Occludin and Claudin-5 in cortical tissue were detected by Western Blot. Double immunofluorescence was used to verify the co-localization of MMP-9 protein and the marker protein of astrocyte GFAP in the cortical tissue of rats. RESULTS: Compared with the sham group, the escape latency in the sepsis group was significantly longer [48-hour escape latency (s): 56.56±6.43 vs. 36.62±3.32, 72-hour escape latency (s): 57.72±7.23 vs. 26.46±4.24, both P < 0.01], the BWC and extravasation of EB were increased [BWC: (84.56±2.03)% vs. (76.82±2.22)%, EB (µg/g): 17.56±2.28 vs. 6.25±1.36, both P < 0.01], the expression of MMP-9 protein was increased (MMP-9/ß-actin: 0.73±0.01 vs. 0.24±0.01, P < 0.01), the protein expressions of Occludin and Claudin-5 were decreased (Occludin/ß-actin: 0.45±0.02 vs. 0.86±0.04, Claudin-5/ß-actin: 0.62±0.03 vs. 0.96±0.05, both P < 0.01). At the same time, the co-localization expression of MMP-9 protein and the astrocytes of the cortical were increased [MMP-9 fluorescence intensity (AU): 38.66±4.26 vs. 17.23±3.04, MMP-9 positive cells: (26.92±1.77)% vs. (12.82±1.46)%, both P < 0.01]. Compared with the sepsis group, the escape latency in resveratrol group was significantly shorter [48-hour escape latency (s): 41.42±6.27 vs. 56.56±6.43, 72-hour escape latency (s): 33.46±7.17 vs. 57.72±7.23, both P < 0.01], the BWC and extravasation of EB were decreased [BWC: (77.15±2.27)% vs. (84.56±2.03)%, EB (µg/g): 7.74±1.88 vs. 17.56±2.28, both P < 0.01], the expression of MMP-9 protein was decreased (MMP-9/ß-actin: 0.25±0.01 vs. 0.73±0.01, P < 0.01), the protein expressions of Occludin and Claudin-5 were increased (Occludin/ß-actin: 0.82±0.03 vs. 0.45±0.02, Claudin-5/ß-actin: 0.92±0.04 vs. 0.62±0.03, both P < 0.01). At the same time, the co-localization expression of MMP-9 protein and the astrocytes of the cortical were decreased [MMP-9 fluorescence intensity (AU): 19.44±4.37 vs. 38.66±4.26, MMP-9 positive cells: (13.11±1.29)% vs. (26.92±1.77)%, both P < 0.01]. CONCLUSIONS: Resveratrol can inhibit the expression of MMP-9 protein in the astrocytes of the cortical cortex of rats, and then reduce the degradation of tight junction proteins of Occludin and Claudin-5, thereby reducing BBB permeability and eventually ameliorate the cognitive dysfunction induced by SAE.

Effects of dexmedetomidine on heart rate control and pre-operative outcome in patients with acute aortic dissection: a propensity-matched analysis.

BACKGROUND: The total survival rate in patients with acute aortic dissection (AAD) has been greatly improved because of surgical technique advances. However, the pre-operative mortality rate remained high. In this study, we sought to evaluate the effects of dexmedetomidine (DEX) on heart rate control and preoperative outcome in AAD. METHODS: Retrospectively enrolled 461 patients who were diagnosed with AAD during the first 7-day after admission and divided into two groups according to the use of intravenous DEX: DEX group (91 patients) and Control group (370 patients). The heart rate and systolic blood pressure (SBP) level in both groups were recorded, and the incidence of aortic dissection rupture and pre-operative survival rates within 7 days were considered as the primary clinical outcomes. RESULTS: Compared to the Control group, heart rate of DEX group in the early 3 hours was significantly higher (P=0.009), and the 24-hour heart rate fluctuation was smaller (P=0.012). There was no difference in the systolic blood pressure (SBP) between the two groups, but the 24-hour fluctuation of SBP in DEX group was less (P=0.003). We performed a propensity-matched analysis to minimize selection bias and found that there were 7 (7.9%) patients in the DEX group occurred acute pulmonary edema, 17 (19.1%) patients in the Control group (P=0.047). And the pre-operative survival rates within 7 days were significantly improved in DEX group (P=0.004). And the pre-operative survival rates within 7 days were significantly improved in DEX group (P=0.004). CONCLUSIONS: DEX can be beneficial to facilitate heart rate control, keep SBP more steady, and reduce the incidence of pre-operative aortic rupture in patients with AAD.

Hypercapnia exacerbates the disruption of the blood­brain barrier by inducing interleukin­1ß overproduction in the blood of hypoxemic adult rats.

Refractory hypoxemia is the main symptom of acute respiratory distress syndrome (ARDS). Low tidal volume ventilation is routinely applied in clinical practice to correct hypoxemia, which aims to prevent ventilator­induced lung injury. However, this ventilation strategy inevitably leads to hypercapnia. Our previous study demonstrated that hypercapnia aggravated cognitive impairment in hypoxemic rats; however, the underlying mechanism remains unclear. The aim of the present study was to investigate whether hypercapnia exacerbates the blood­brain barrier (BBB) disruption through inducing interleukin (IL)­1ß overproduction in the blood of hypoxemic rats. The BBB permeability in a rat model of hypercapnia/hypoxemia was evaluated. The levels of IL­1ß in the blood of rats and human whole­blood cultures were assessed. The expression of IL­1 receptor 1 (IL­1R1), phosphorylated IL­1R1­associated kinase (p­IRAK­1) and tight junctional proteins in cerebral vascular endothelial cells was examined in vitro and in vivo. In addition, IL­1Ra, an IL­1 receptor antagonist, was used to determine whether hypercapnia affects tight junctional protein expression in hypoxic cerebral vascular endothelial cells through inducing IL­1ß overproduction. It was observed that hypercapnia alone did not disrupt the BBB, but aggravated the damage to the BBB integrity in hypoxemic rats. Hypercapnia increased IL­1ß expression in the blood of hypoxemic rats as well as in hypoxic human whole­blood cultures. IL­1R1 and p­IRAK­1 expression was increased, while that of tight junctional proteins was reduced by hypercapnia in hypoxemic cerebral vascular endothelial cells in vitro and in vivo. Additionally, the expression of tight junctional proteins was markedly increased following treatment with IL­1Ra. These results suggest that hypercapnia­induced IL­1ß overproduction in the hypoxemic blood may decrease tight junctional protein expression in cerebrovascular endothelial cells via the IL­1R1/p­IRAK­1 pathway, further disrupting BBB integrity, and eventually resulting in increased BBB permeability.