Electroacupuncture regulates hepatic cholesterol synthesis by HMGCR deubiquitination in rats.

This experiment was designed to explore the effect and mechanism of electroacupuncture (EA) for hyperlipidemia and hepatic cholesterol synthesis in rats. Liver and adipose tissues were assessed histologically, and body and liver weight, serum and liver lipid levels, expression of mTOR/ubiquitin-specific peptidase 20 (USP20)/recombinant 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), and phosphorylation of mTOR and USP20 were measured. In vitro deubiquitination assays with liver cytosol were conducted. EA at Fenglong point ameliorated hyperlipidemia and hepatocyte steatosis, and decreased p-USP20, p-mTOR and HMGCR expression in the liver by reducing deubiquitination. Furthermore, EA decreased feeding-induced lipid biosynthesis in the liver. Concomitantly, EA prevented the induction of phosphorylated USP20 and mTOR, and HMGCR expression; and reduced the deubiquitination of HMGCR after re-feeding. This experiment demonstrated that EA can effectively improve hyperlipidemia and reduce hepatic cholesterol synthesis by counteracting the deubiquitination activity of HMGCR in hyperlipidemic rats.

[Protective effect and mechanism of electroacupuncture of "Biao-Ben" acupoints combination for mitochondrial dysfunction in diabetic nephropathy rats].

OBJECTIVE: To study the protective effect of electroacupuncture (EA) at "Biao"-acupoints, "Fenglong"(ST40) and "Zhongwan"(CV12), used for treating symptoms of the disease, and "Ben"-acupoints, "Zusanli"(ST36) and "Guanyuan"(CV4), for treating the root cause of the disease on oxidative stress injury of renal mitochondria through SIRT1/PGC-1α signal pathway in rats with diabetic nephropathy (DN). METHODS: A total of 33 male Wistar rats were randomized into normal (n=10), model (n=12) and EA (n=11) groups.The DN model was established by feeding the rats with high-sugar and high-fat diet for 6 weeks combined with streptozotocin (STZ, 35 mg/kg, i.p.). EA (4 Hz/60 Hz, 1 mA)was applied to ST36-ST40 and CV4-CV12 for 15 min, once every other day for 8 weeks. The rats' body weight was recorded, urine in 24 hours (24-h UP) was collected to measure the urine protein level, and the fasting blood glucose (FBG) level detected by using a glucometer. The levels of serum glycosylated hemoglobin (HbA1c), creatinine (Scr) and urea nitrogen (BUN) were assayed using immunoturbidi-metry, picric acid method and urease method, respectively, and those of serum triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) detected using an automatic biochemical analyzer. The kidney tissue was collected for assaying the activity of superoxide dismutase (SOD) with xanthine oxidase method, glutathione (GSH) activity with dithio-dinitrobenzoic acid method, catalase （CAT） activity with ammonium molybdate spectrometric method, and malondialdehyde (MDA) content with thiobarbituric acid method. Histopathological changes of the kidney tissue were observed by microscope after hematoxylin-eosin staining (HE), periodate Schiff staining (PAS) and Masson staining, separately, and its subcellular structure was observed under transmission electron microscopy. The expression levels of renal SIRT1 and PGC-1α mRNAs and proteins were detected by quantitative real-time PCR and Western blot, and the immunoactivity of renal α-smooth muscle actin (α-SMA), and immunofluorescence density of renal collagen Ⅰ (Col Ⅰ), collagen Ⅳ(Col Ⅳ) and fibronec-tin (FN) detected by immunohistochemistry and immunofluorescence assay, respectively. RESULTS: Compared with the normal group, the levels of FBG, HbA1c, BUN, Scr, 24-h UP, TG, TC, LDL-C, MDA, α-SMA, Col Ⅰ, Col Ⅳ and FN proteins were significantly increased (P<0.01), and the levels of body weight, HDL-C, SOD, GSH, CAT, SIRT1 and PGC-1α mRNAs and proteins were decreased in the model group (P<0.01, P<0.05). In comparison with the model group, the levels of FBG, HbA1c, BUN, Scr, 24-h UP, TG, TC, LDL-C and MDA, and the expressions of α-SMA, Col Ⅰ, Col Ⅳ and FN proteins were markedly down-regulated (P<0.05, P<0.01), and those of body weight, HDL-C, SOD, GSH, CAT, and the expressions of SIRT1 and PGC-1α mRNAs and proteins significantly up-regulated (P<0.01, P<0.05) in the EA group. HE staining showed mesangial dilatation, glomerular hypertrophy and mesangial matrix accumulation; PAS staining showed an increase of the glomerular extracellular matrix deposition; and Masson staining displayed an enhancement of glomerular fibrosis and interstitial space expansion; and electron microscope revealed foot process fusion, basement membrane thickening and organelle injury in the rat's kidney of the model group, which were relatively milder in the EA group. CONCLUSION: EA of ST36-ST40 and CV4-CV12, "Biao-Ben" acupoints combination, can alleviate oxidative stress and mitochondrial dysfunction in DN rats, which may be associated with its functions in up-regulating SIRT1/PGC-1α signaling, and decreasing renal fibrosis.

[Electroacupuncture preconditioning alleviates renal injury and oxidative stress through Sirt3/MnSOD pathway in type 2 diabetic rats].

OBJECTIVE: To explore the protective effect and molecular mechanism of electroacupuncture (EA) preconditioning on renal injury in type 2 diabetic rats. METHODS: Fifty male Wistar rats were randomly divided into control, model, EA, EA+inhibitor, and inhibitor groups, with 10 rats in each group. Diabetes model was established by high fat and high glucose diet and intraperitoneal injection of streptozotocin (40 mg/kg). EA (2 Hz, 1 mA) preconditioning was applied to "Guanyuan" (CV4), "Zhongwan" (CV12), bilateral "Zusanli" (ST36) and "Fenglong" (ST40) for 15 min, once every other day for 8 weeks. Rats of the inhibitor and EA+inhibitor groups were given intraperitoneal injection of 3-TYP (50 mg/kg) once every other day for a total of 3 times. The body weight, kidney mass, and renal index were recorded. The contents of urine microalbumin (ALB), 24 h urine 8-hydroxydeoxyguanosine (8-OHdG) and activities of reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), glutathione glycine peroxidase (GSH-Px) in kidney were detected by ELISA. The activities of mitochondrial respiratory chain enzyme complex (RCCⅠ-RCCⅣ) in kidney were detected using spectrophotometric method. HE staining, Masson staining and transmission electron microscopy were used to observe the changes of renal structure. The protein and mRNA expressions of silent information regulator 3 (Sirt3), manganese superoxide dismutase (MnSOD) in kidney were detected by Western blot and quantitative real-time PCR, respectively. RESULTS: After modeling and compared with the control group, the contents of ALB, the renal index, activity of ROS and content of 8-OHdG, and the renal collagen volume fraction (CVF) were increased (P<0.01), while the activities of SOD, CAT and GSH-Px, RCCⅠ-RCCⅣ, and the mRNA and protein expressions of Sirt3 and MnSOD were decreased (P<0.01). After the treatment and compared with the model group, the contents of ALB, the renal index, ROS, 8-OHdG, and the CVF were decreased in the EA group(P<0.01, P<0.05), while the activities of SOD, CAT, GSH-Px, RCCⅠ-RCCⅣ, and Sirt3 and MnSOD expression levels were increased (P<0.01, P<0.05)；the RCCⅡ activity and the expression level of MnSOD mRNA were increased (P<0.05) in the EA+inhibitor group; the ALB and 8-OHdG contents and the CVF in the inhibitor group were increased (P<0.05), while the activity of SOD, and Sirt3 and MnSOD expression levels were decreased (P<0.05). In comparison with the EA group, the contents of ALB, the renal index, activities of ROS and 8-OHdG contents, and the CVF were increased (P<0.05, P<0.01), activities of SOD, CAT and GSH-Px and RCCⅠ and RCCⅡ, and the mRNA and protein expressions of Sirt3 and MnSOD were decreased (P<0.05, P<0.01) in both EA+inhibitor group and inhibitor group, whereas the activities of RCCⅢ and RCCⅣ were decreased in the inhibitor group (P<0.05). The therapeutic effect of inhibitor was notably inferior to that of EA+inhibitor in decreasing ALB and 8-OHdG contents, and CVF (P<0.01), and in up-regulating SOD and RCCⅡ activities, Sirt3 and MnSOD expression levels (P<0.01, P<0.05). CONCLUSION: EA preconditioning can increase the expressions of renal Sirt3 and MnSOD in type 2 diabetic rats, thereby reducing the oxidative stress response and protecting the kidneys.

[Electroacupuncture of "Biaoben acupoints" relieves kidney injury by suppressing oxidative stress in diabetic nephropathy rats].

OBJECTIVE: To observe the effect of electroacupuncture (EA) of combined "Biao"- and "Ben"-acupoint (for treating symptoms and root causes of the disease, respectively) on the expression of kidney forkhead box O1 (FoxO1) and peroxi-some proliferator-activated receptor-γ coactivator-1α (PGC-1α) in diabetic nephropathy (DN) rats, so as to explore its potential mechanisms underlying improvement of DN. METHODS: Wistar rats were randomly divided into normal control (n=10), DN model (n=12), EA (n=11), EA+inhibitor (AS1842856 targeting FoxO1, n=11) and inhibitor (n=11) groups. The DN model was established by high fat and high glucose diet for 6 weeks and intraperitoneal injection of streptozotocin (55 mg/kg). EA (2 Hz, 1 mA) was applied to bilateral "Zusanli"(ST36), "Guanyuan"(CV4), "Fenglong" (ST40) and "Zhongwan"(CV12) for 15 min, once every other day for 8 weeks. The body mass was recorded, and blood glucose detected. The serum was sampled for detecting creatinine (Scr) content with Jaffe's assay, urea nitrogen (BUN) content with urease method. Urine albumin (ALB) and renal reactive oxygen species (ROS) contents were detected with ELISA, renal superoxide dismutase (SOD) activity with xanthine oxidase method, and renal malondialdehyde (MDA) content with thiobarbituric acid method. The renal subcellular structure was observed under transmission electron microscopy, and the expression levels of PGC-1α and FoxO1 proteins in the kidney tissue were detected using Western blot. RESULTS: Compared with the normal control group, the levels of body mass, SOD activity, and FoxO1 and PGC-1α protein expression were significantly reduced (P<0.01), while the contents of blood glucose, and serum Scr and BUN, urine ALB, renal MDA and ROS levels significantly increased in the model group (P<0.01). In comparison with the model group, the levels of body mass, SOD activity, and FoxO1 and PGC-1α expression were significantly increased in the three treatment groups except SOD, expression of FoxO1 and PGC-1α in the inhibitor group (P<0.01, P<0.05), and the contents of blood glucose, Scr, BUN, ALB, MDA and ROS were obviously decreased in the three treatment groups except ALB and ROS in the inhibitor group (P<0.01, P<0.05). The therapeutic effect of EA was notably superior to that of EA+inhibitor and inhibitor in increasing body mass, SOD activity, and FoxO1 and PGC-1α expression levels (P<0.05, P<0.01), and in down-regulating blood glucose, BUN, ALB and ROS levels (P<0.05, P<0.01), suggesting a reduction of the therapeutic effect of EA after administration of the inhibitor AS1842856 of FoxO1. Results of electron microscopy showed diffusely thickened and vague basement membrane, increased mesangial matrix, fused foot process, and reduced volume of endothelial cells with pykno-tic nucleus of the kidney tissue in the model group, which was obviously milder in both EA and EA+inhibitor groups particularly in the EA group. CONCLUSION: EA increases the expression of FoxO1 and PGC-1α in the kidneys of DN rats, thereby reducing the oxidative stress response and protecting the kidneys.

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.

Electroacupuncture Regulates TRPV1 through PAR2/PKC Pathway to Alleviate Visceral Hypersensitivity in FD Rats.

Visceral hypersensitivity (VH) is the predominant pathogenesis of functional dyspepsia (FD). Duodenal hypersensitivity along with nausea further reduces the comfort level in gastric balloon dilatation and inhibits gastric receptive relaxation. The potential mechanism behind electroacupuncture- (EA-) mediated alleviation of VH has not been elucidated. In an FD rat model with tail clamping stress, iodine acetamide (IA) induced VH. The rats were treated with EA with or without PAR2 antagonist FSLLRY-NH2, and the body weight, gastric sensitivity, compliance, and gastrointestinal motility were determined. Mast cells and activated degranulation were stained with toluidine blue (TB) staining and visualized under a transmission electron microscope (TEM). Immunofluorescence was used to detect the expression of PAR2, PKC, and TRPV1 in the duodenum and dorsal root ganglion (DRG) and that of CGRP, SP in DRG, and c-fos in the spinal cord. EA alone and EA + antagonist enhanced the gastrointestinal motility but diminished the expression of TRPV1, CGRP, SP, and c-fos-downstream of PAR2/PKC pathway and alleviated VH in FD rats. However, there was no obvious superposition effect between the antagonists and EA + antagonists. The effect of EA alone was better than that of antagonists and EA + antagonists 2 alone. EA-induced amelioration of VH in FD rats was mediated by TRPV1 regulation through PAR2/PKC pathway. This protective mechanism involved several pathways and included several targets.

Electroacupuncture Pretreatment at Neiguan (PC6) attenuates autophagy in rats with myocardial ischemia reperfusion through the phosphatidylinositol 3-kinase-Akt-mammalian target of rapamycin pathway.

OBJECTIVE: To investigate the protective efficacy of electroacupuncture (EA) pretreatment at Neiguan (PC6) on myocardial ischemia-reperfusion (I/R) in rats. METHODS: Fifty rats were randomly divided into five groups (n = 10): sham operation group, model group (underwent in vivo myocardial I/R), EA pretreatment group [EA at Neiguan (PC 6) 1 week before I/R], wortmannin group (1 week before I/R, the PI3K inhibitor, wortmannin, was injected), EA pretreatment + wortmannin group (both pretreatments were performed simultaneously). After establishing the I/R model, 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to analyze the weight and area of the myocardial infarction tissue. The biosignal and pressure test system was used to determine the left ventricular systolic mean pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), fractional shortening (FS), and ejection fraction (EF). Ultraviolet spectrophotometry was used to determine the expression of creatine kinase (CK)-MB, inducible nitric oxide synthase (iNOS), and total antioxidant capacity (T-AOC) in the serum. The expression of autophagy-related protein 13 (ATG13), mammalian target of rapamycin (mTOR), and phosphatidylinositol 3-kinase (PI3K) in cardiac muscle cells was determined by immunofluorescence. Hematoxylin and eosin staining was used to observe autophagy-related pathological changes in rat cardiomyocytes, and ultrastructural changes of cardiomyocytes were examined by transmission electron microscopy. RESULTS: In this study, the infarction size and tissue weight of the EA pretreatment group were decreased compared with the model group (P < 0.0001). Furthermore, compared with the model group, the LVEDP values of the EA pretreatment group were significantly reduced (P = 0.0091), and the LVSP, FS, and EF values were slightly increased (P = 0.0007, 0.0020, 0.0031). EA pretreatment also significantly decreased the expression of CK-MB and iNOS, while it increased the expression of T-AOC in the serum of rats with I/R injury (P < 0.0001). Furthermore, EA pretreatment slightly widened the myocardial fiber space, reduced necrosis and myocardial cell swelling and maintained the nucleus and mitochondria structure intact. CONCLUSION: EA pretreatment promoted autophagy flux and alleviated myocardial I/R injury through the PI3K-Akt-mTOR pathway.

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.

Hypertonic saline mediates the NLRP3/IL-1ß signaling axis in microglia to alleviate ischemic blood-brain barrier permeability by downregulating astrocyte-derived VEGF in rats.

INTRODUCTION: The aim of this study was to explore whether the antibrain edema of hypertonic saline (HS) is associated with alleviating ischemic blood-brain barrier (BBB) permeability by downregulating astrocyte-derived vascular endothelial growth factor (VEGF), which is mediated by microglia-derived NOD-like receptor protein 3 (NLRP3) inflammasome. METHODS: The infarct volume and BBB permeability were detected. The protein expression level of VEGF in astrocytes in a transient focal brain ischemia model of rats was evaluated after 10% HS treatment. Changes in the NLRP3 inflammasome, IL-1ß protein expression, and the interleukin-1 receptor (IL1R1)/pNF-кBp65/VEGF signaling pathway were determined in astrocytes. RESULTS: HS alleviated the BBB permeability, reduced the infarct volume, and downregulated the expression of VEGF in astrocytes. HS downregulates IL-1ß expression by inhibiting the activation of the NLRP3 inflammasome in microglia and then downregulates VEGF expression by inhibiting the phosphorylation of NF-кBp65 mediated by IL-1ß in astrocytes. CONCLUSIONS: HS alleviated the BBB permeability, reduced the infarct volume, and downregulated the expression of VEGF in astrocytes. HS downregulated IL-1ß expression via inhibiting the activation of the NLRP3 inflammasome in microglia and then downregulated VEGF expression through inhibiting the phosphorylation of NF-кBp65 mediated by IL-1ß in astrocytes.

[Electroacupuncture at "Zusanli"(ST36) promotes gastrointestinal motility possibly by suppres-sing excessive autophagy via AMPK/ULK1 signaling in rats with functional dyspepsia].

OBJECTIVE: To explore the effect of electroacupuncture (EA) at "Zusanli" (ST36) on gastrointestinal motility and expression of autophagy marker LC3 and autophagy signaling pathway molecule AMP-activated protein kinase (AMPK) in rats with functional dyspepsia (FD), so as to explore its mechanisms underlying improvement of FD. METHODS: A total of 40 male SD rats were randomly divided into blank control, model, EA, AMPK inhibitor and EA＋AMPK inhibitor groups, with 8 rats in each group. The FD model was established by tail-clip (30 min/time, twice daily) ＋ single day feeding, and gavage of normal saline (2 mL/time, twice a day) for 2 successive weeks. For rats of EA and EA＋AMPK inhibitor groups, EA (4 Hz, 1.0 mA) was applied to bilateral ST36 for 20 min, once daily for 7 successive days. For rats of the AMPK-inhibitor and EA＋AMPK inhibitor groups, Compound C (20 mg/kg) solution was administered by intraperitoneal injection before every EA administration. The gastric residual rate and small intestinal transit rate were calculated based on the weight of stomach and length of ink propelling and total small intestine, respectively. The expression levels of c-kit, microtubule-associated protein 1 light chain 3, Beclin 1, phosphorylated (p)-AMPK and p-unc-51 like autophagy activating kinase 1(ULK1) in the gastric antrum tissue were detected by using Western blot. RESULTS: Compared with the blank control group, the gastric residual rate and the expression levels of LC3-Ⅱ/LC3Ⅰ， Beclin 1, p-AMPK and p-ULK1 proteins were significantly increased, and the small intestinal transit rate and the expression of c-kit protein obviously decreased in the model group (P<0.01). After EA intervention, modeling-induced increase of gastric residual rate and the expression of LC3-Ⅱ/LC3Ⅰ， Beclin 1, p-AMPK and p-ULK1 proteins, and decrease of small intestinal transit rate and expression of c-kit protein were reversed in the EA, AMPK inhibitor and EA＋AMPK inhibitor groups (P<0.05, P<0.01). The therapeutic effect of EA and EA＋AMPK was significantly superior to that of AMPK inhibitor in down-regulating the expression of LC3Ⅱ/LC3Ⅰ， Beclin 1, p-AMPK and p-ULK1 proteins and in up-regulating the expression of c-kit protein (P<0.05, P<0.01). No significant differences were found among the EA, AMPK inhibitor and EA＋AMPK inhibitor groups in lowering gastric residual rate and elevating the small intestinal transit rate (P>0.05). CONCLUSION: EA at ST36 can promote gastrointestinal motility in FD rats, which is possibly mediated by inhibiting excessive autophagy of interstitial cells of Cajal via down-regulating AMPK/ULK1 signaling.

Hypercapnia induces IL-1ß overproduction via activation of NLRP3 inflammasome: implication in cognitive impairment in hypoxemic adult rats.

BACKGROUND: Cognitive impairment is one of common complications of acute respiratory distress syndrome (ARDS). Increasing evidence suggests that interleukin-1 beta (IL-1ß) plays a role in inducing neuronal apoptosis in cognitive dysfunction. The lung protective ventilatory strategies, which serve to reduce pulmonary morbidity for ARDS patients, almost always lead to hypercapnia. Some studies have reported that hypercapnia contributes to the risk of cognitive impairment and IL-1ß secretion outside the central nervous system (CNS). However, the underlying mechanism of hypercapnia aggravating cognitive impairment under hypoxia has remained uncertain. This study was aimed to explore whether hypercapnia would partake in increasing IL-1ß secretion via activating the NLRP3 (NLR family, pyrin domain-containing 3) inflammasome in the hypoxic CNS and in aggravating cognitive impairment. METHODS: The Sprague-Dawley (SD) rats that underwent hypercapnia/hypoxemia were used for assessment of NLRP3, caspase-1, IL-1ß, Bcl-2, Bax, and caspase-3 expression by Western blotting or double immunofluorescence, and the model was also used for Morris water maze test. In addition, Z-YVAD-FMK, a caspase-1 inhibitor, was used to treat BV-2 microglia to determine whether activation of NLRP3 inflammasome was required for the enhancing effect of hypercapnia on expressing IL-1ß by Western blotting or double immunofluorescence. The interaction effects were analyzed by factorial ANOVA. Simple effects analyses were performed when an interaction was observed. RESULTS: There were interaction effects on cognitive impairment, apoptosis of hippocampal neurons, activation of NLRP3 inflammasome, and upregulation of IL-1ß between hypercapnia treatment and hypoxia treatment. Hypercapnia + hypoxia treatment caused more serious damage to the learning and memory of rats than those subjected to hypoxia treatment alone. Expression levels of Bcl-2 were reduced, while that of Bax and caspase-3 were increased by hypercapnia in hypoxic hippocampus. Hypercapnia markedly increased the expression of NLRP3, caspase-1, and IL-1ß in hypoxia-activated microglia both in vivo and in vitro. Pharmacological inhibition of NLRP3 inflammasome activation and release of IL-1ß might ameliorate apoptosis of neurons. CONCLUSIONS: The present results suggest that hypercapnia-induced IL-1ß overproduction via activating the NLRP3 inflammasome by hypoxia-activated microglia may augment neuroinflammation, increase neuronal cell death, and contribute to the pathogenesis of cognitive impairments.

Hypertonic saline attenuates expression of Notch signaling and proinflammatory mediators in activated microglia in experimentally induced cerebral ischemia and hypoxic BV-2 microglia.

BACKGROUND: Ischemic stroke is a major disease that threatens human health in ageing population. Increasing evidence has shown that neuroinflammatory mediators play crucial roles in the pathophysiology of cerebral ischemia injury. Notch signaling is recognized as the cell fate signaling but recent evidence indicates that it may be involved in the inflammatory response in activated microglia in cerebral ischemia. Previous report in our group demonstrated hypertonic saline (HS) could reduce the release of interleukin-1 beta and tumor necrosis factor-alpha in activated microglia, but the underlying molecular and cellular mechanisms have remained uncertain. This study was aimed to explore whether HS would partake in regulating production of proinflammatory mediators through Notch signaling. RESULTS: HS markedly attenuated the expression of Notch-1, NICD, RBP-JK and Hes-1 in activated microglia both in vivo and in vitro. Remarkably, HS also reduced the expression of iNOS in vivo, while the in vitro levels of inflammatory mediators Phos-NF-κB, iNOS and ROS were reduced by HS as well. CONCLUSION: Our results suggest that HS may suppress of inflammatory mediators following ischemia/hypoxic through the Notch signaling which operates synergistically with NF-κB pathway in activated microglia. Our study has provided the morphological and biochemical evidence that HS can attenuate inflammation reaction and can be neuroprotective in cerebral ischemia, thus supporting the use of hypertonic saline by clinicians in patients with an ischemia stroke.

Hypertonic saline protects brain endothelial cells against hypoxia correlated to the levels of epidermal growth factor receptor and interleukin-1ß.

OBJECTIVE: The aim of this study was to verify the protective effect of hypertonic saline (HS) on brain endothelial cells under hypoxic conditions and the relevant underlying mechanism. METHODS: bEnd.3 cells were treated with oxygen-glucose deprivation (OGD)-induced injury. To measure HS performance, cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt assay, and cell apoptosis was assessed by flow cytometry and Terminal deoxynucleotidyl transferase UTP nick-end labeling staining. RNA-seq was performed to assess the expression profiles and screen the candidate genes that participated in OGD-induced injury and the HS protective effect. Quantitative real-time polymerase chain reaction (qPCR) and western blot analysis were used to confirm the expression of candidate genes, and enzyme-linked immunosorbent assay was used to measure the level of interleukin (IL)-1ß. Overexpression analyses were performed to confirm the functions of the differentially expressed genes. RESULTS: HS with a concentration of 40 mmol/L NaCl had an obvious protective effect on bEnd.3 cells after OGD-induced injury, resulting in increased cell viability and a smaller percentage of apoptotic cells. According to the RNA-seq results, epidermal growth factor receptor (EGFR) was chosen as the differentially expressed gene target in this study. The qPCR and western blot analyses further confirmed that the levels of EGFR/phosphorylated epidermal growth factor receptor and IL-1ß were enhanced after OGD-induced injury, but attenuated after treatment with 40 mmol/L of NaCl HS. Overexpressed EGFR reversed the protective effect of HS that caused low viability and high rates of apoptosis in cells. CONCLUSION: HS can protect endothelial cells against OGD-induced injury, but is affected by the expression of EGFR/p-EGFR and IL-1ß.

Huperzine A protects sepsis associated encephalopathy by promoting the deficient cholinergic nervous function.

Neuroinflammatory deregulation in the brain plays a crucial role in the pathogenesis of sepsis associated encephalopathy (SAE). Given the mounting evidence of anti-inflammatory and neuroprotective effects of the cholinergic nervous system, it is surprising that there is little information about its changes in the brain during sepsis. To elucidate the role of the cholinergic nervous system in SAE, hippocampal choline acetyltransferase, muscarinic acetylcholine receptor-1, acetylcholinesterase and acetylcholine were evaluated in LPS-induced sepsis rats. Expression of pro-inflammatory cytokines, neuronal apoptosis, and animal cognitive performance were also assessed. Furthermore, therapeutic effects of the acetylcholinesterase inhibitor Huperzine A (HupA) on the hippocampal cholinergic nervous function and neuroinflammation were evaluated. A deficiency of the cholinergic nervous function was revealed in SAE, accompanied with over-expressed pro-inflammatory cytokines, increase in neuronal apoptosis and brain cognitive impairment. HupA remarkably promoted the deficient cholinergic nervous function and attenuated the abnormal neuroinflammation in SAE, paralleled with the recovery of brain function. We suggest that the deficiency of the cholinergic nervous function and the abnormal neuroinflammation are synergistically implicated in the pathogenesis of SAE. Thus, HupA is a potential therapeutic candidate for SAE, as it improves the deficient cholinergic nervous function and exerts anti-inflammatory action.

Hypertonic saline alleviates cerebral edema by inhibiting microglia-derived TNF-α and IL-1ß-induced Na-K-Cl Cotransporter up-regulation.

BACKGROUND: Hypertonic saline (HS) has been successfully used clinically for treatment of various forms of cerebral edema. Up-regulated expression of Na-K-Cl Cotransporter 1 (NKCC1) and inflammatory mediators such as tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ß) has been demonstrated to be closely associated with the pathogenesis of cerebral edema resulting from a variety of brain injuries. This study aimed to explore if alleviation of cerebral edema by 10% HS might be effected through down-regulation of inflammatory mediator expression in the microglia, and thus result in decreased NKCC1 expression in astrocytes in the cerebral cortex bordering the ischemic core. METHODS: The Sprague-Dawley (SD) rats that underwent right-sided middle cerebral artery occlusion (MCAO) were used for assessment of NKCC1, TNF-α and IL-1ß expression using Western blotting, double immunofluorescence and real time RT-PCR, and the model also was used for evaluation of brain water content (BWC) and infarct size. SB203580 and SP600125, specific inhibitors of the p38 and JNK signaling pathways, were used to treat primary microglia cultures to determine whether the two signaling pathways were required for the inhibition of HS on microglia expressing and secreting TNF-α and IL-1ß using Western blotting, double immunofluorescence and enzyme-linked immunosorbent assay (ELISA). The effect of TNF-α and IL-1ß on NKCC1 expression in primary astrocyte cultures was determined. In addition, the direct inhibitory effect of HS on NKCC1 expression in primary astrocytes was also investigated by Western blotting, double immunofluorescence and real time RT-PCR. RESULTS: BWC and infarct size decreased significantly after 10% HS treatment. TNF-α and IL-1ß immunoexpression in microglia was noticeably decreased. Concomitantly, NKCC1 expression in astrocytes was down-regulated. TNF-α and IL-1ß released from the primary microglia subjected to hypoxic exposure and treatment with 100 mM HS were decreased. NKCC1 expression in primary astrocytes was concurrently and progressively down-regulated with decreasing concentration of exogenous TNF-α and IL-1ß. Additionally, 100 mM HS directly inhibited NKCC1 up-regulation in astrocytes under hypoxic condition. CONCLUSIONS: The results suggest that 10% HS alleviates cerebral edema through inhibition of the NKCC1 Cotransporter, which is mediated by attenuation of TNF-α and IL-1ß stimulation on NKCC1.