Hippocampal microglial activation triggers a neurotoxic-specific astrocyte response and mediates etomidate-induced long-term synaptic inhibition.

BACKGROUND: Accumulating evidence has highlighted the importance of microglial and astrocyte responses in the pathological development of postoperative cognitive dysfunction (POCD). However, the mechanisms involved are not well understood. METHODS: A perioperative neurocognitive disorders (PND) mouse model was generated by administering etomidate, and cognitive function was assessed using the Morris water maze and novel object recognition tests. Excitatory and inhibitory postsynaptic currents were recorded to analyze neuronal activity. In addition, microglia and astrocytes were isolated by magnetic-activated cell sorting, and genes that were activated in these cells were identified using quantitative polymerase chain reaction. RESULTS: We observed dramatic cognitive impairment at 1 and 3 weeks after etomidate was administered to 18 month-old mice. Microglia and astrocytes isolated from the hippocampus showed significant microglial activation during the early pathological stage (i.e., 1 week after etomidate injection) and an A1-specific astrocyte response during the late pathological stage (i.e., 3 weeks after etomidate injection). Furthermore, when microglia were eliminated before etomidate was injected, the A1-specific astrocyte activation response was significantly reduced, and cognitive function improved. However, when microglia were eliminated after etomidate application, astrocyte activation and cognitive function were not significantly altered. In addition, activating microglia immediately after a sedative dose of etomidate was injected markedly increased A1-specific astrocyte activation and cognitive dysfunction. CONCLUSIONS: A1-specific astrocyte activation is triggered by activated microglia during the initial pathological stage of PND and induces long-term synaptic inhibition and cognitive deficiencies. These results improve our understanding of how PND develops and may suggest therapeutic targets.

Distinguishable Immunologic Characteristics of COVID-19 Patients with Comorbid Type 2 Diabetes Compared with Nondiabetic Individuals.

BACKGROUND: COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has threatened every civilian as a global pandemic. The immune system poses the critical interactive chain between the human body and the virus. Here, we make efforts to examine whether comorbidity with type 2 diabetes (T2D) affects the immunological response in COVID-19 patients. METHODS: We conducted a retrospective pilot study investigating immunological characteristics of confirmed cases of COVID-19 with or without comorbid T2D. Two subcohorts of sex- and age-matched participants were eligible for data analysis, of which 33 participants were with T2D and the remaining 37 were nondiabetic (NDM). Cellular immunity was assessed by flow cytometric determination of surface markers including CD3, CD4, CD8, CD19, CD16, and CD56 in peripheral blood. Levels of C reactive protein, immunoglobulin (IgG, IgM, IgA, and IgE), and complements (C3, C4) were detected by rate nephelometry immunoassay. And Th1/Th2 cytokines (IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ) were detected by Cytometric Bead Array. RESULTS: Neutrophil counts were found to be significantly higher in the T2D group than in the NDM group and had a significant relevance with clinical severity. Lymphocyte frequencies showed no significant differences in the two groups. However, the proportions and absolute counts of T, Tc, Th, and NK cells decreased in both groups to different degrees. An abnormal increase in neutrophil count and a decrease in lymphocyte subpopulations may represent risk factors of COVID-19 severity. The level of IgG, IgM, IgA, C3, and C4 showed no significant difference between the two groups, while the IgE levels were higher in the T2D group than in the NDM group (p < 0.05). Th1 cytokines including IFN-γ, TNF-α, and IL-6, as well as CRP, appeared significantly higher in the T2D group. CONCLUSIONS: The COVID-19 patients comorbid with T2D demonstrated distinguishable immunological parameters, which represented clinical relevancies with the predisposed disease severity in T2D.

Administration of losartan improves aortic arterial stiffness and reduces the occurrence of acute coronary syndrome in aged patients with essential hypertension.

BACKGROUNDS AND AIMS: Increased arterial stiffness may increase cardiovascular morbidity and mortality. Angiotensin II type 1 receptor blocker losartan is potentially useful in controlling the central blood pressure and arterial stiffness in mild to moderate essential hypertension, while the effects of losartan in aged patients with essential hypertension are not entirely investigated. METHODS: The carotid-femoral arterial pulse wave velocity (PWV) was measured in aged patients with essential hypertension. RESULTS: In a cross-sectional study, PWV value was significantly higher in these old patients with essential hypertension, compared with patients without essential hypertension. Logistic regression analysis indicated that age, hypertension duration, and losartan treatment are risk factors of arterial stiffness. In a perspective study, long-term administration of losartan (50 mg/d) remarkably reduced PWV in aged patients with essential hypertension. In a longitudinal study, PWV is an independent predictor of the occurrence of acute coronary syndrome (ACS) in elderly patients with essential hypertension by using multivariate analysis. Further, the ACS occurrence was reduced by long-term administration of losartan in aged patients with essential hypertension, compared with the old hypertensive patients without taking losartan. CONCLUSION: Losartan treatment is a negative risk factor of arterial stiffness and reduces the risk of ACS in aged patients with essential hypertension.

Berberine suppresses the ectopic expression of miR-133a in endothelial cells to improve vascular dementia in diabetic rats.

Objective: Vascular dementia is the second leading cause of dementia, which is strongly associated with diabetes. Ectopic expression of miR-133a in endothelial cells is involved in endothelial dysfunction in diabetes. Whether berberine, as a natural product in Coptis chinensis, improves vascular dementia induced by diabetes remains unknown.Methods: Diabetes and subsequent vascular dementia were induced in rats by injecting streptozotocin (50 mg/kg/day) for five consecutive days. The expression of miR-133a was determined by fluorescence in situ hybridization. The learning and memory were evaluated by step-down, step-through, and morris water maze (MWM) tests.Results: In streptozotocin-injected rats, hyperglycemia dramatically induced miR-133a ectopic expressions in vascular endothelium, reduced GTPCH1 gene expressions and BH4 levels, which were reversed by berberine administration (1.0 g/kg/day, 8 weeks). Hyperglycemia also inhibited acetylcholine-induced vasorelaxation in middle cerebral artery and reduced blood supply to the brain, which were bypassed by berberine. Ex vivo studies indicated that miR-133a agomirs abolished these beneficial effects of berberine on acetylcholine-induced vasorelaxation, while supplement of L-sepiapterin prevented endothelial dysfunction in middle cerebral artery isolated from rats. By performing step-down, step-through, and MWM tests, we observed that hyperglycemia significantly caused the impairments of learning and memory in streptozotocin-injected rats. Importantly, these aberrant phenotypes in diabetic rats were normalized by berberine therapy. Finally, berberine reduced miR-133a expression, and increased both BH4 levels and NO production in cultured endothelial cells treated with high glucose.Conclusion: Berberine improves vascular dementia in diabetes, which is possibly related to the suppression of miR-133a ectopic expression in endothelial cells.

Inhibition of acid-sensing ion channel currents by propofol in rat dorsal root ganglion neurons.

Acid-sensing ion channels (ASICs), part of the epithelial sodium channel/degenerin family, are activated by extracellular protons. The ASICs play a significant role in the acidosis-mediated perception of pain. The anaesthetic agent propofol also exerts antinociceptive effects, but the underlying mechanisms for this effect are not clear. We used whole-cell patch clamping to investigate the effect of propofol on proton-gated currents in: (i) rat dorsal root ganglion (DRG) neurons; and (ii) HEK293 cells transfected with either ASIC1a or ASIC3. Propofol inhibited the amplitude of proton-gated currents in DRG neurons, but did not change the sensitivity of ASICs to H(+). Notably, propofol altered acid-evoked excitability of rat DRG neurons and decreased the number of action potentials induced by acid stimuli. In addition, we demonstrated that propofol inhibited ASICs by directly binding with these channels in HEK293 cells. These results suggest that propofol inhibits proton-gated currents in DRG neurons and that inhibition of proton-gated currents explains, in part, the antinociceptive effects of propofol in primary afferent neurons.

Mycophenolate mofetil attenuates myocardial ischemia-reperfusion injury via regulation of the TLR4/NF-κB signaling pathway.

It has been well documented that the Toll-like receptor 4 (TLR4)/NF-κB signaling pathway mediates early inflammatory responses during myocardial ischemia and reperfusion (MI/R). Mycophenolate mofetil (MMF), an immunosuppressive agent, has been shown to confer protective effects against ischemia/reperfusion injury, possibly through its immunosuppressive and anti-inflammatory actions. The aim of the present study was to investigate whether MMF could modulate the TLR4/NF-κB signaling, inhibit cell apoptosis and subsequently attenuate MI/R injury. MMF (20 mg/kg) or vehicle was administered to SD rats by gavage. The rats were then subjected to MI/R injury. The results showed that after MI/R, the expressions of myocardial TLR4 and NF-κB were significantly increased, and apoptosis of cardiomyocytes was induced, as evidenced by the decreased mitochondrial membrane potential (MMP), decreased Bcl-2 protein level, and increased Bax expression. Administration of MMF attenuated MI/R injury. Further studies demonstrated that MMF inhibited the induction of TLR4, NF-κB and Bax expression, and restored the expression of bcl-2. Moreover, increased myeloperoxidase activity and serum level of tumor necrotic factor α induced by MI/R injury were also inhibited by MMF treatment. In conclusion, our results demonstrated that MMF attenuates MI/R injury through inhibition of the TLR4/NF-κB signaling pathway, which led to reduced inflammatory reaction and subsequently myocardial cell apoptosis.

Malnutrition Contributes to Low Lymphocyte Count in Early-Stage Coronavirus Disease-2019.

Background and Aim: Lymphocytes play an important role in fighting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Low total lymphocyte count (TLC), which contributes to poor clinical outcomes, is common in persons with coronavirus disease 2019 (COVID-19). The current explanation for the cause of low TLC is that it is directly related to the invasiveness of SARS-CoV-2, which attacks lymphocytes. We hypothesized that malnutrition contributes to the development of low TLC in early-stage COVID-19. Methods: We prospectively enrolled 101 patients with confirmed COVID-19. On their first day of hospitalization, we collected baseline and laboratory data, including clinical symptoms; the Sequential Organ Failure Assessment, Nutrition Risk Screening 2002 and Subjective Global Assessment were used to assess the malnutrition status of the patients. Multivariable logistic regression was used to identify independent risk factors for low TLC and severe COVID-19. Results: Malnutrition was associated with lower TLC in COVID-19. Fifty-nine (58.4%) of the patients showed low TLC, 41 (40.6%) were at risk for malnutrition, and 18 of them were malnourished. Low TLC was an independent risk factor for severe COVID-19. Compared to patients with normal TLC, those with low TLC more often presented with anorexia, malnutrition, higher SOFA scores (P < 0.05) and comorbidities (diabetes and malignancies). Malnutrition (OR: 3.05, 95% CI: 1.5-6.19, P = 0.006) and SOFA scores (OR: 1.51, 95% CI: 1.04-2.43, P = 0.042) were identified as independent risk factors for low TLC. Conclusions: Malnutrition was common among our patients with early-stage COVID-19, and it contributed to the occurrence of low TLC.

Efficacy and Safety of Leflunomide for Refractory COVID-19: A Pilot Study.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may persist in patients with coronavirus disease 2019 (COVID-19) despite receiving standard care. Methods: In this pilot study of hospitalized adult patients (≥18 years of age), with radiologically confirmed pneumonia who were SARS-CoV-2 positive for more than 28 days despite standard care, were assigned to receive standard of care (SOC, grp I) or leflunomide + SOC (grp 2). After 2 weeks, grp 1 and grp 2 patients who continued to be SARS-CoV-2-positive received leflunomide for 14 days while continuing SOC. The primary outcomes were the rate of and time to SARS-CoV-2 clearance and the 14-day and 30-day hospital discharge rate. Results: 12 patients were enrolled in grp 1 and 15 patients were in grp 2. The 14 days SARS-CoV-2 viral clearance rate was 80.0% (12/15) for grp 2 patients receiving leflunomide vs. 16.7% for grp 1 patients (2/12) (p = 0.002). By day 14, the median time to SARS-CoV-2 clearance was 6.0 days (range 1-12, IQR 1-12) for grp 2 patients. In grp 1, two patients converted to viral negative on days 1 and 6 (p = 0.002). The 14-day discharge rate was 73.3% (11/15) for the grp 2 vs. 8.3% (1/12) for grp 1 (p = 0.001). The 30 days discharge rate was 100% (15/15) for the grp 2 vs. 66.7% (8/12) for grp 1. No severe adverse events or deaths were reported. Conclusion: Leflunomide may improve the SARS-CoV-2 clearance rate and discharge rate in patients with refractory COVID-19. The tolerability of the 14-28 days course of treatment with leflunomide is acceptable. These preliminary observations need to be verified by a large sample size and randomized controlled trial.

Differences in the Clinical and Hematological Characteristics of COVID-19 Patients with and without Type 2 Diabetes.

OBJECTIVE: To examine whether comorbidity with type 2 diabetes (T2D) affects the clinical and hematological parameters of coronavirus disease 2019 (COVID-19) patients. METHODS: We retrospectively investigated the clinical, imaging, and laboratory characteristics of patients with confirmed COVID-19 who were hospitalized from January 30, 2020 to March 17, 2020, at the Renmin Hospital of Wuhan University. A detailed clinical record was kept for each subject, including the medical history of COVID-19 and physical and laboratory examinations. A total of 164 subjects were eligible for the study, among which 40 patients were comorbid with T2D. Further analysis was conducted in two subcohorts of sex- and age-matched patients with and without T2D to identify hematological and biochemical differences. The laboratory tests, including routine blood tests, serum biochemistry, and coagulation function, were performed upon admission. RESULTS: The two groups showed no significant differences in baseline parameters, including age, sex, chest X-ray, or computed tomography (CT) findings, upon admission. However, patients with T2D showed an increased incidence of diarrhea. T2D patients required more recovery time from pneumonia, as shown by follow-up CT findings, which might contribute to the prolonged hospitalization. Comorbidity with T2D also increased risk of secondary bacterial infection during COVID-19. The T2D group had significantly higher white blood cell and neutrophil counts compared with the nondiabetic group, but T2D patients suffered from more severe lymphocytopenia and inflammation (P < 0.05). Most biochemical parameters showed no significant differences between the two groups (P > 0.05). However, patients with T2D seemed to have a significantly higher risk of developing hyperlactatemia, hyponatremia, and hypocalcemia. CONCLUSIONS: COVID-19 patients comorbid with T2D demonstrated distinguishing clinical features and hematological parameters during the infection. It is necessary to develop a different clinical severity scoring system for COVID-19 patients with T2D. This study may provide helpful clues for the assessment and management of COVID-19 in T2D patients.

Pioglitazone prevents sevoflurane­induced neuroinflammation and cognitive decline in a rat model of chronic intermittent hypoxia by upregulating hippocampal PPAR­Î³.

Post­operative cognitive dysfunction is a common complication after anesthesia and surgery. Sevoflurane (SEV), a widely used inhalational anesthetic, can exaggerate neuroinflammation and cause cognitive dysfunction under chronic intermittent hypoxia (CIH) conditions by downregulating hippocampal peroxisome proliferator­activated receptor­Î³ (PPAR­Î³). In the present study, it was examined whether treatment with PPAR­Î³ agonist pioglitazone (PIO) is beneficial in counteracting SEV­induced neuroinflammation and cognitive decline in a rat model of CIH. Rats were exposed to CIH for 4 weeks. After 2 weeks of CIH, these animals underwent either 2.6% SEV or control (CON) exposure for 4 h. PIO (60 mg/kg) or vehicle (VEH) was administered orally twice daily for 2 weeks, starting one day prior to SEV or CON exposure. Compared with CIH­CON+VEH rats, CIH­SEV+VEH rats exhibited significant cognitive decline as indicated by increased latency to locate the hidden platform and shorter dwell­time in the goal quadrant in the Morris Water Maze task. Molecular studies revealed that CIH­SEV+VEH rats had increased proinflammatory cytokine expression and microglial activation in the hippocampus, which were associated with decreased PPAR­Î³ activity. Notably, SEV­induced cognitive decline and increases in proinflammatory cytokine expression and microglial activation were prevented by PIO, which increased hippocampal PPAR­Î³ activity. PIO also increased hippocampal PPAR­Î³ activity in CIH­CON rats but did not alter proinflammatory cytokine expression and microglial activation as well as cognitive function. Additionally, expression of hippocampal PPAR­α and PPAR­ß, two other PPAR isotypes, were comparable among the groups. These data suggest that PIO prevents SEV­induced exaggeration of neuroinflammation and cognitive decline under CIH conditions by upregulating hippocampal PPAR­Î³. PIO may have the potential to prevent anesthetic SEV­induced cognitive decline in surgical patients with obstructive sleep apnea.

Transcatheter Closure Versus Repeat Surgery for the Treatment of Postoperative Left-to-Right Shunts: A Single Center 15-Year Experience.

BACKGROUND: Repeat surgery and the percutaneous approach (transcatheter closure (TCC)) have been used for the management of postoperative left-to-right shunts. In this study, we described our 15 years of experience in treating postoperative left-to-right shunts with these two approaches. METHODS: From February 2002 to February 2017, 50 patients with residual left-to-right shunts, following cardiac surgery, were treated using TCC or repeat surgery. Clinical examination, standard 12-lead electrocardiography, chest X-ray, and a transthoracic echocardiogram were performed before hospital discharge and at all follow-ups. RESULTS: The closure rate was 100% in both groups and there was no procedure-related mortality. Patients with TCC had few complications. The procedure time and duration of hospital stay for TCC patients were 58.9 ± 27.7 min and 6.1 ± 0.8 days, respectively. Eleven out of 19 patients receiving reoperation suffered serious complications after surgery, e.g., bleeding and nosocomial infections. The operation time and duration of hospital stay for reoperation patients were 256.7 ± 60.5 min and 17.0 ± 4.0 days, respectively. No other serious complications were seen at all follow-up visits for both groups. CONCLUSIONS: In conclusions, TCC is safe and effective for the management of postoperative left-to-right shunts, and is associated with few complications, which can be the favored closure strategy over repeat surgery for the management of postoperative left-to-right shunts.

Transcatheter closure of calcified patent ductus arteriosus in older adult patients: Immediate and 12-month follow-up results.

OBJECTIVE: To present our experience in transcatheter closure of calcified patent ductus arteriosus (PDA) in older adult patients, which has rarely been reported. PATIENTS: From 2009 to 2014, a total of 16 patients (median age 58 years) with calcified PDA underwent transcatheter closure in our center. All patients were symptomatic with major symptoms being exertional dyspnea (in 12), palpitations (in 8), and fatigue (in 5). A continuous murmur was heard in all patients. The median ductus diameter was 4 mm (range 3-7 mm). The median Qp/Qs was 1.6 (range 1.4-2.9). INTERVENTIONS: Transcatheter closure was performed for all patients. The size of the occluder selected was 2-3 mm greater than the narrowest portion of PDA. We experienced difficulties in advancing the multipurpose catheter through the calcified duct in about one third of patients (5/16). Considering that calcified tissue has a greater tendency to rupture, hence, to close PDA in these patients, they adopted the retrograde wire-assisted technique and modified the procedure to reduce the shear stress of sheath and avoid any sheath kinking. For the remaining 11 patients, the advancement of the multipurpose catheter through the calcified duct was smooth and the conventional antegrade approach was applied. OUTCOME MEASURES: Clinical examination, standard 12-lead electrocardiography, chest x-ray, and transthoracic echocardiography were performed before hospital discharge, at 1-, 3-, 6-, and 12-months follow-ups. RESULTS: All PDAs were successfully closed. There were no deaths. Three patients had a trivial residual shunt, with one also having intravascular hemolysis. Following pharmacological treatment, hemolysis signs vanished at 7 days postprocedure. The trivial residual shunt disappeared in all three patients at 3-month follow-up. No new-onset residual shunt, device embolization, device dislocation, infective endocarditis, or embolism was observed at all follow-up time points. CONCLUSION: Successful closure of calcified PDA with few complications in older adult patients was achieved using the duct occluder.

Correlation between nuclear factor κB activity and pulmonary artery pressure in a rat high pulmonary blood flow model.

The aim of the present study was to investigate the correlation between nuclear factor-κB (NF-κB) activity and pulmonary artery pressure in the pulmonary artery endothelial cells of high pulmonary blood flow rat models. A total of 50 four-week-old male Wistar rats were randomly divided into four groups: Surgery shunt group (Tn, n=15); surgery + pyrollidine dithiocarbamate (PDTC) administration group (Ti, n=15); sham control group (Co, n=10) and negative control group (Cn, n=10). The 30 rats of the Ti and Tn groups underwent carotid artery-external jugular vein anastomosis; the 15 rats in the Ti group were injected with PDTC intraperitoneally 1 h prior to surgery for a two-week continuous infusion. After 12 weeks of feeding ad libitum, right ventricular systolic pressure and NF-κB activity in the pulmonary artery endothelial cells of the rats were measured. The NF-κB activity of the Tn group was significantly higher than that of the Cn group (P<0.01) and the NF-κB activity of the Ti group was lower than that of the Cn group (P<0.01); however, no significant difference was observed between the Co and Cn groups. The increased activity of NF-κB was an important factor in the pulmonary vasoconstriction and structural remodeling of rats with high pulmonary blood flow.

Chloroquine impairs visual transduction via modulation of acid sensing ion channel 1a.

Acid-sensing ion channels (ASICs) are extracellular pH sensors activated by protons, which influence retinal activity and phototransduction. Among all ASICs, ASIC1a is abundantly expressed in the retina and involved in normal retinal activity. Chloroquine, which has been used in the treatment of malaria, rheumatoid arthritis and systemic lupus erythematosus, has been shown to be toxic to the retina. However, the underlying mechanisms remain unclear. In this study, we investigated the role of chloroquine in phototransduction by measuring the electroretinogram (ERG). The effect of chloroquine on acid-evoked currents in either isolated rat retinal ganglion neurons (RGNs) or Chinese hamster ovary (CHO) cells transfected with ASIC1a were assessed using a whole-cell patch-clamp technique. Chloroquine reduced the b-wave of scotopic 0.01 and photopic 3.0 and amplitudes of oscillatory potentials (OPs), an effect which was almost completely reversed by PcTx1, an ASIC1a-specific channel blocker. Further, patch-clamp experiments demonstrated that chloroquine reduced the peak current amplitude and prolonged the activation and desensitization of ASIC1a currents. These chloroquine-induced effects on the kinetics of ASIC 1a were dose-, pH- and Ca(2+)-dependent. Taken together, these results demonstrate that chloroquine affects vision conduction by directly modifying the kinetics of ASIC1a. Such a mechanism, may, in part, explain the retinal toxicity of chloroquine.