Pathogenesis Of Encephalopathy Research Articles

Neuronal let-7b-5p acts through the Hippo-YAP pathway in neonatal encephalopathy

Despite increasing knowledge on microRNAs, their role in the pathogenesis of neonatal encephalopathy remains to be elucidated. Herein, we identify let-7b-5p as a significant microRNA in neonates with moderate to severe encephalopathy from dried blood spots using next generation sequencing. Validation studies using Reverse Transcription and quantitative Polymerase Chain Reaction on 45 neonates showed that let-7b-5p expression was increased on day 1 in neonates with moderate to severe encephalopathy with unfavourable outcome when compared to those with mild encephalopathy. Mechanistic studies performed on glucose deprived cell cultures and the cerebral cortex of two animal models of perinatal brain injury, namely hypoxic-ischaemic and intrauterine inflammation models confirm that let-7b-5p is associated with the apoptotic Hippo pathway. Significant reduction in neuronal let-7b-5p expression corresponded with activated Hippo pathway, with increased neuronal/nuclear ratio of Yes Associated Protein (YAP) and increased neuronal cleaved caspase-3 expression in both animal models. Similar results were noted for let-7b-5p and YAP expression in glucose-deprived cell cultures. Reduced nuclear YAP with decreased intracellular let-7b-5p correlated with neuronal apoptosis in conditions of metabolic stress. This finding of the Hippo-YAP association with let-7b needs validation in larger cohorts to further our knowledge on let-7b-5p as a biomarker for neonatal encephalopathy.

A Narrative Review of Circular RNAs in Brain Development and Diseases of Preterm Infants.

Circular RNAs (circRNAs) generated by back-splicing are the vital class of non-coding RNAs (ncRNAs). Circular RNAs are highly abundant and stable in eukaryotes, and many of them are evolutionarily conserved. They are blessed with higher expression in mammalian brains and could take part in the regulation of physiological and pathophysiological processes. In addition, premature birth is important in neurodevelopmental diseases. Brain damage in preterm infants may represent the main cause of long-term neurodevelopmental disorders in surviving babies. Until recently, more and more researches have been evidenced that circRNAs are involved in the pathogenesis of encephalopathy of premature. We aim at explaining neuroinflammation promoting the brain damage. In this review, we summarize the current findings of circRNAs properties, expression, and functions, as well as their significances in the neurodevelopmental impairments, white matter damage (WMD) and hypoxic-ischemic encephalopathy (HIE). So we think that circRNAs have a direct impact on neurodevelopment and brain injury, and will be a powerful tool in the repair of the injured immature brain. Even though their exact roles and mechanisms of gene regulation remain elusive, circRNAs have potential applications as diagnostic biomarkers for brain damage and the target for neuroprotective intervention.

Supplementation with Branched-Chain Amino Acids Induces Unexpected Deleterious Effects on Astrocyte Survival and Intracellular Metabolism with or without Hyperammonemia: A Preliminary In Vitro Study.

Introduction Ammonia is a key component in the pathogenesis of hepatic encephalopathy. Branched-chain amino acids (BCAA) have been reported to improve the symptoms of HE induced by hyperammonemia; however, we recently reported that ammonia increases intracellular levels of BCAA and exerts toxic effects on astrocytes. Objectives This follow-up study was designed to confirm the direct effects of BCAA on human astrocytes and clarify their underlying mechanisms using metabolome analysis and evaluation of associated signaling. Methods We performed cytotoxicity and cell proliferation tests on astrocytes following BCAA treatment with and without ammonium chloride (NH4Cl) and then compared the results with the effects of BCAA on hepatocytes and neurons. Subsequently, we used metabolomic analysis to investigate intracellular metabolite levels in astrocytes with and without BCAA treatment. Results The astrocytes showed increased leakage of intracellular lactate dehydrogenase and reduced proliferation rate upon BCAA treatment. Interestingly, our analysis showed a BCAA-induced impairment of intracellular glycolysis/glyconeogenesis as well as amino acid and butyric acid metabolism. Furthermore, BCAA treatment was found to cause decreased levels of Glut-1 and phosphorylated GSK-3β and mTOR in astrocytes. Conclusions Although further investigations of the effect of BCAA on human astrocytes with hyperammonemia are needed, our work demonstrates that BCAA supplementation has direct negative effects on astrocyte survival and intracellular metabolism.

Математична модель діабетичної енцефалопатії в діагностиці ускладнених форм цукрового діабету

Мета дослідження — оптимізувати методи діагностики діабетичної енцефалопатії, що ґрунтуються на вивченні індикаторів цереброваскулярної гемодинаміки, функціонального стану головного мозку, метаболічних порушень і морфологічних характеристик мозкової тканини. Матеріали та методи. Під спостереженням перебувало 537 хворих на цукровий діабет (ЦД), у тому числі із ЦД 1-го типу — 342 (63,7 %) особи, 2-го типу — 195 (36,3 %). Результати. У статті наведені дані щодо комплексного вивчення клінічних, метаболічних і функціональних показників діабетичної енцефалопатії. Аргументована їх діагностична значимість. На підставі комплексної оцінки отримані дані, що розширили уявлення про патогенез діабетичної енцефалопатії та підтвердили пріоритетність метаболічних порушень. Встановлено діагностичні критерії діабетичної енцефалопатії та розроблено її математичну модель. Висновки. Використання розроблених інформативних індикаторів дозволяє діагностувати ранні стадії діабетичної енцефалопатії або передбачити її розвиток.

Efficacy of Zinc Supplement in Minimal hepatic Encephalopathy: A prospective, Randomized Controlled Study (Zinc-MHE Trial).

Background:Minimal hepatic encephalopathy (MHE) in patients with cirrhosis of the liver has a negative impact on the quality of daily life by impairing attention, memory and visuomotor coordination, and resulting in cognitive decline. Ammonia is thought to be part of the pathogenesis of hepatic encephalopathy. Zinc is an essential trace element, one of the cofactor enzymes that is essential for the conversion of ammonia to urea. Aim:To assess the effect of zinc supplementation on psychomotor performance in cirrhotic patients with MHE. Methods:This prospective, randomized, controlled trial recruited 69 cirrhotic patients (age 18-75 years) diagnosed with MHE by neuropsychometric (NP) tests comprised of the number connection test part A (NCT-A), number connection test part B (NCT-B), serial dot test (SDT), line tracing test (LTT) and digit symbol test (DST). Eligible patients were randomly assigned (1:1) by a computer-based system block of four randomizations to receive 45 mg of elemental zinc or placebo for 12 weeks. The primary endpoint was the absolute change in NP tests from baseline to 12-weeks of zinc supplement compared with placebo. The assessment of changes of the health-related quality of life (HRQOL) using the Short Form survey-36 (SF-36) questionnaire, as well as biochemical parameters including serum ammonia, was also conducted in both groups. Results:From January to December 2020, 125 eligible cirrhotic patients were diagnosed with liver cirrhosis, of whom 69 (55%) had MHE and were randomly assigned to treatment: 35 patients were assigned to receive 45 mg of elemental zinc and the others 34 patients to receive placebo. Significant improvements in NP tests were established in the zinc supplement group when compared with the placebo group (NCT-A, p = 0.029; NCT-B, p = 0.008; SDT, p = 0.002; DST, p = <0.001). A significant improvement of HRQOL assessed by the SF-36 score was only seen in the zinc group (p<0.001). In the zinc supplement group, not only was an improvement in psychomotor performance reported, but quality of life was also improved, irrespective of baseline zinc level. Conclusion:Twelve weeks of zinc supplement in cirrhotic patients with MHE not only had a positive effect on psychomotor performance but also improved HRQOL irrespective to baseline zinc level.

18F]PBR146 and [18F]DPA-714 in vivo Imaging of Neuroinflammation in Chronic Hepatic Encephalopathy Rats.

Neuroinflammation is an important pathogenesis of hepatic encephalopathy (HE). The upregulation of translocator protein (TSPO) during neuroinflammation provides an imaging molecular target to evaluate the severity of neuroinflammation in chronic HE rats. [18F]DPA-714 and [18F]PBR146 targeting TSPO are often used for neuroinflammation imaging. This study performed bile duct ligation (BDL) in rats to simulate chronic HE model, tested the behavioral experiments, and conducted [18F]PBR146 and [18F]DPA-714 micro-PET/CT scans followed analyzing the average %ID/g values of the whole brain, brain regions and main organs of subjects. After sacrifice the rats, the blood plasma samples were taken for blood biochemical indexes and plasma inflammatory factor levels examination, the liver and brain specimens were obtained for pathological analysis. The BDL rats showed chronic liver failure with defects in cognition, motor coordination ability and mental state. [18F]PBR146 and [18F]DPA-714 micro-PET/CT imaging results were similar in whole brain of BDL group and Sham group. Besides, some regional brain areas in BDL rats were found abnormal uptakes mainly located in basal ganglia area, auditory cortex, motor cortex, cingulate gyrus, somatosensory cortex, hippocampus, thalamus, midbrain, and medulla oblongata, and these regions also correlated with behavioral alterations. In conclusion, both [18F]PBR146 and [18F]DPA-714 had the similar imaging effects in hepatic encephalopathy models could quantitatively evaluate neuroinflammation load and distribution. The difference brain regions with higher uptake values of radiotracers in BDL rats were correlated with behavioral alterations.

Kynurenic Acid and Its Synthetic Derivatives Protect Against Sepsis-Associated Neutrophil Activation and Brain Mitochondrial Dysfunction in Rats.

Background and AimsThe systemic host response in sepsis is frequently accompanied by central nervous system (CNS) dysfunction. Evidence suggests that excessive formation of neutrophil extracellular traps (NETs) can increase the permeability of the blood–brain barrier (BBB) and that the evolving mitochondrial damage may contribute to the pathogenesis of sepsis-associated encephalopathy. Kynurenic acid (KYNA), a metabolite of tryptophan catabolism, exerts pleiotropic cell-protective effects under pro-inflammatory conditions. Our aim was to investigate whether exogenous KYNA or its synthetic analogues SZR-72 and SZR-104 affect BBB permeability secondary to NET formation and influence cerebral mitochondrial disturbances in a clinically relevant rodent model of intraabdominal sepsis.MethodsSprague–Dawley rats were subjected to fecal peritonitis (0.6 g kg-1 ip) or a sham operation. Septic animals were treated with saline or KYNA, SZR-72 or SZR-104 (160 µmol kg-1 each ip) 16h and 22h after induction. Invasive monitoring was performed on anesthetized animals to evaluate respiratory, cardiovascular, renal, hepatic and metabolic parameters to calculate rat organ failure assessment (ROFA) scores. NET components (citrullinated histone H3 (CitH3); myeloperoxidase (MPO)) and the NET inducer IL-1β, as well as IL-6 and a brain injury marker (S100B) were detected from plasma samples. After 24h, leukocyte infiltration (tissue MPO) and mitochondrial complex I- and II-linked (CI–CII) oxidative phosphorylation (OXPHOS) were evaluated. In a separate series, Evans Blue extravasation and the edema index were used to assess BBB permeability in the same regions.ResultsSepsis was characterized by significantly elevated ROFA scores, while the increased BBB permeability and plasma S100B levels demonstrated brain damage. Plasma levels of CitH3, MPO and IL-1β were elevated in sepsis but were ameliorated by KYNA and its synthetic analogues. The sepsis-induced deterioration in tissue CI–CII-linked OXPHOS and BBB parameters as well as the increase in tissue MPO content were positively affected by KYNA/KYNA analogues.ConclusionThis study is the first to report that KYNA and KYNA analogues are potential neuroprotective agents in experimental sepsis. The proposed mechanistic steps involve reduced peripheral NET formation, lowered BBB permeability changes and alleviation of mitochondrial dysfunction in the CNS.

Encephalopathy in COVID-19 Patients

The clinical presentation of coronavirus disease 2019 (COVID-19) has a wide spectrum, ranging from asymptomatic patients to severe presentations with acute respiratory distress syndrome (ARDS), kidney injury, stroke, electrolyte imbalance, and multi-organ failure. Encephalopathy and encephalitis are devastating severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) virus‐associated central nervous system complications.We reported a case of a 67-year-old male who was admitted to the hospital for the management of COVID-19 pneumonia. Due to worsening hypoxia, the patient was transferred to ICU and was intubated. On examination, he was aphasic and noted to have right-sided hemiplegia with left-sided hemiparesis on day 4. CT scan of the head without contrast and MRI findings were suggestive of acute necrotizing encephalopathy secondary to intracranial cytokine storm caused by viral infection. The patient was treated with intravenous immunoglobulin (IVIG), and high dose corticosteroids, with clinical improvement in the right-sided hemiparesis on day 5. A repeat MRI brain revealed decreased edema.The pathogenesis of encephalopathy associated with COVID-19 may be multifactorial. Postulated mechanisms include hypoxic/metabolic changes produced by the intense inflammatory response due to cytokine storm and neurotropism. Cytokine storm causes hypoxia and metabolic insults that result in global dysfunction of the brain. Altered consciousness, ranging from mild confusion, delirium, to deep coma, are some of the cardinal clinical features. The most common imaging finding on MRI T2-weighted fluid-attenuated inversion recovery (MRI T2/FLAIR) includes symmetric, multifocal lesions with invariable thalamic involvement. Other commonly involved locations include the brainstem, cerebral white matter, cortical and subcortical white matter, and cerebellum. In a few case reports, cerebrospinal fluid (CSF) analysis has shown the presence of the virus. Management of encephalopathy in COVID-19 patients involves supportive care including supplemental oxygen therapy and immune modulators. Immune modulation therapy including high-dose corticosteroids and IVIG have been shown to improve outcomes in these patients.

NU9056, a KAT 5 Inhibitor, Treatment Alleviates Brain Dysfunction by Inhibiting NLRP3 Inflammasome Activation, Affecting Gut Microbiota, and Derived Metabolites in LPS-Treated Mice.

Background: The pathogenesis of sepsis-associated encephalopathy (SAE) is complicated, while the efficacy of current treatment technologies is poor. Therefore, the discovery of related targets and the development of new drugs are essential.Methods: A mouse model of SAE was constructed by intraperitoneal injection of lipopolysaccharide (LPS). LPS treatment of microglia was used to build an in vitro model of inflammation. Nine-day survival rates, behavioral testing, transmission electron microscopy (TEM), immunohistochemical (IHC), immunofluorescence (IF), and ELISA were performed. The expression levels of Occludin, Claudin 5, NLRP3, caspase-1, and ASC genes and proteins were detected by RT-qPCR or Western blot. Caspase-1 P10 (Casp-1 P10) protein expression was detected. 16S rDNA sequencing and gas chromatography-mass spectrometer (GC-MS) were used to analyze the gut microbiota and metabolism. Flow cytometric experiment and Cell Counting Kit-8 (CCK8) assay were performed.Results: NU9056 improved the survival rate of mice and alleviated LPS-induced cognitive impairment, anxiety, and depression in vivo. The tight junctions were thickened via NU9056 treatment. Further, the mRNAs and proteins expression levels of Occludin and Claudin 5 were up-regulated by NU9056. NU9056 increased the expression level of DCX. The expression levels of Iba-1, NLRP3, IL-1β, ASC, and Casp-1 P10 were down-regulated by NU9056. The composition of the gut microbiota changed. Kyoto Encyclopedia of Genes and Genomes data predicted that the effects of NU9056 might be related to apoptosis and tight junction pathways. NU9056 up-regulated the concentration of acetate, propionate, and butyrate. NU9056 significantly reduced LPS-induced apoptosis of microglia, the average fluorescence intensity of ROS, and the release of IL-1β and IL-18, while improving cell viability in vitro.Conclusions: NU9056 might effectively alleviate LPS-induced cognitive impairment and emotional disorder in experimental mice by inhibiting the NLRP3 inflammasome. The therapeutic effects may be related to gut microbiota and derived metabolites. NU9056 might be a potential drug of SAE prevention.

Exposures of Phenylacetic Acid and Phenylacetylglutamine Across Different Subpopulations and Correlation with Adverse Events.

BackgroundElevated plasma ammonia is central to the pathogenesis of hepatic encephalopathy. Sodium phenylacetate or glycerol phenylbutyrate is approved for urea cycle disorders, but limited clinical data are available for hepatic encephalopathy. Phenylacetic acid (PAA) plasma exposure has been reported to correlate with neurologic adverse events in patients with cancer but not in patients with urea cycle disorders or hepatic encephalopathy. Ornithine phenylacetate, an intravenous dosage form of the l-ornithine salt of phenylacetate, is under development for hepatic encephalopathy.ObjectiveThis analysis summarized the pharmacokinetics and safety of ornithine phenylacetate to support the dosing strategy and to assist with the monitoring and management of neurologic adverse events in a global clinical development program.MethodsPhenylacetic acid and phenylacetylglutamine (PAGN) pharmacokinetic data and adverse events from five clinical studies were included in the analysis. Hepatic and renal dysfunction were assessed by baseline Child–Pugh score and creatinine clearance, respectively. Predicted plasma exposures of PAA at the occurrence of neurologic adverse events were used for exposures and neurologic adverse event analysis.ResultsPhenylacetic acid exhibited nonlinear pharmacokinetics. Phenylacetic acid exposure was 35% higher in Child–Pugh C than in Child–Pugh B. No significant pharmacokinetic difference was identified between Caucasian and Asian subjects after body weight adjustment. Phenylacetylglutamine renal clearance decreased by five-fold in severe renal impairment compared with subjects with normal renal function. Renal dysfunction significantly elevated PAGN plasma concentrations; however, elevated PAGN due to reduced excretion of PAGN did not change PAA exposure and plasma ammonia levels. No correlation was observed between PAA plasma exposure and neurologic adverse events in patients with stable cirrhosis or acute hepatic encephalopathy.ConclusionsDose adjustment should be considered for patients with low body weight and severely impaired hepatic function. Phenylacetic acid plasma exposure was not correlated with neurologic adverse events in the ornithine phenylacetate target patient population.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40262-021-01047-5.

The mTOR/NF-κB Pathway Mediates Neuroinflammation and Synaptic Plasticity in Diabetic Encephalopathy.

Diabetic encephalopathy, a severe complication of diabetes mellitus, is characterized by neuroinflammation and aberrant synaptogenesis in the hippocampus leading to cognitive decline. Mammalian target of rapamycin (mTOR) is associated with cognition impairment. Nuclear factor-κB (NF-κB) is a transcription factor of proinflammatory cytokines. Although mTOR has been ever implicated in processes occurring in neuroinflammation, the role of this enzyme on NF-κB signaling pathway remains unclear in diabetic encephalopathy. In the present study, we investigated whether mTOR regulates the NF-κB signaling pathway to modulate inflammatory cytokines and synaptic plasticity in hippocampal neurons. In vitro model was constructed in mouse HT-22 hippocampal neuronal cells exposed to high glucose. With the inhibition of mTOR or NF-κB by either chemical inhibitor or short-hairpin RNA (shRNA)-expressing lentivirus-vector, we examined the effects of mTOR/NF-κB signaling on proinflammatory cytokines and synaptic proteins. The diabetic mouse model induced by a high-fat diet combined with streptozotocin injection was administrated with rapamycin (mTOR inhibitor) and PDTC (NF-κB inhibitor), respectively. High glucose significantly increased mTOR phosphorylation in HT-22 cells. While inhibiting mTOR by rapamycin or shmTOR significantly suppressed high glucose-induced activation of NF-κB and its regulators IKKβ and IκBα, suggesting mTOR is the upstream regulator of NF-κB. Furthermore, inhibiting NF-κB by PDTC and shNF-κB decreased proinflammatory cytokines expression (IL-6, IL-1β, and TNF-α) and increased brain-derived neurotrophic factor (BDNF) and synaptic proteins (synaptophysin and PSD-95) in HT-22 cells under high glucose conditions. Besides, the mTOR and NF-κB inhibitors improved cognitive decline in diabetic mice. The inhibition of mTOR and NF-κB suppressed mTOR/NF-κB signaling pathway, increased synaptic proteins, and improved ultrastructural synaptic plasticity in the hippocampus of diabetic mice. Activating mTOR/NF-κB signaling pathway regulates the pathogenesis of diabetic encephalopathy, such as neuroinflammation, synaptic proteins loss, and synaptic ultrastructure impairment. The findings provide the implication that mTOR/NF-κB is potential new drug targets to treat diabetic encephalopathy.

The critical role of hippocampal dopamine in the pathogenesis of hepatic encephalopathy.

The pathogenesis of hepatic encephalopathy (HE) has been generally linked to blood ammonia, gamma-aminobutyric acid and serotonin. However, the exact mechanism remains unclear. In the present study, we aimed to explore the role of hippocampal dopamine (DA) and its receptors in the pathogenesis of HE through the use of behavioral testing, western blotting, and immunofluorescence staining in normal rats, HE model rats and rats treated with the DA precursor-levodopa (L-DOPA). HE model rats manifested fibrotic livers and showed serious behavioral disorders. They also had significantly lower hippocampal DA content and increased expression of both D1 and D2 receptors relative to normal rats. After treatment with L-DOPA, the HE model rats showed normal behavior and expression of D1 returned to normal levels. Furthermore, pretreatment with the D1 antagonist SCH23390 blocked the therapeutic effect of L-DOPA on behavior in HE model rats. Taken together, these results clarify that the decrease in hippocampal DA plays a role in the pathogenesis of HE and that this effect is mediated by D1. These findings provide new evidence for the pathogenesis of HE.

New approaches to the pathogenesis, clinic, and treatment of hepatic encephalopathy

This review article presents new approaches to the assessment of key pathogenesis factors, clinical features, and treatment of hepatic encephalopathy (HE) associated with liver cirrhosis. Various clinical variants of the course of HE in patients with cirrhosis of the liver areconsidered, which are important for the choice of treatment and prevention of repeated relapses of HE. Analyzed the ammonia hypothesis of pathogenesis and associated hyperammonemia, which is the basis of most modern treatment methods. These data on the activation of the adaptive pathway for removing ammonia in the form of glutamine are used in the further study of drugs that enhance the clearance of ammonia. The possibility of reducing GABA-ergic tone due to the effect of the antagonist on the neurosteroid site in the GABA receptor complex is emphasized.

Therapeutic Hypothermia Inhibits the Classical Complement Pathway in a Rat Model of Neonatal Hypoxic-Ischemic Encephalopathy.

ObjectiveComplement activation is instrumental in the pathogenesis of Hypoxic-ischemic encephalopathy (HIE), a significant cause of neonatal mortality and disability worldwide. Therapeutic hypothermia (HT), the only available treatment for HIE, only modestly improves outcomes. Complement modulation as a therapeutic adjunct to HT has been considered, but is challenging due to the wide-ranging role of the complement system in neuroinflammation, homeostasis and neurogenesis in the developing brain. We sought to identify potential therapeutic targets by measuring the impact of treatment with HT on complement effector expression in neurons and glia in neonatal HIE, with particular emphasis on the interactions between microglia and C1q.MethodsThe Vannucci model was used to induce HIE in term-equivalent rat pups. At P10-12, pups were randomly assigned to three different treatment groups: Sham (control), normothermia (NT), and hypothermia (HT) treatment. Local and systemic complement expression and neuronal apoptosis were measured by ELISA, TUNEL and immunofluorescence labeling, and differences compared between groups.ResultsTreatment with HT is associated with decreased systemic and microglial expression of C1q, decreased systemic C5a levels, and decreased microglial and neuronal deposition of C3 and C9. The effect of HT on cytokines was variable with decreased expression of pro and anti-inflammatory effectors. HT treatment was associated with decreased C1q binding on cells undergoing apoptosis.ConclusionOur data demonstrate the extreme complexity of the immune response in neonatal HIE. We propose modulation of downstream effectors C3a and C5a as a therapeutic adjunct to HT to enhance neuroprotection in the developing brain.

Cognitive Dysfunction in Non-Alcoholic Fatty Liver Disease-Current Knowledge, Mechanisms and Perspectives.

Non-alcoholic fatty liver disease (NAFLD) has emerged as the hepatic component of the metabolic syndrome and now seemingly affects one-fourth of the world population. Features associated with NAFLD and the metabolic syndrome have frequently been linked to cognitive dysfunction, i.e. systemic inflammation, vascular dysfunction, and sleep apnoea. However, emerging evidence suggests that NAFLD may be a cause of cognitive dysfunction independent of these factors. NAFLD in addition exhibits dysbiosis of the gut microbiota and impaired urea cycle function, favouring systemic ammonia accumulation and further promotes systemic inflammation. Such disruption of the gut–liver–brain axis is essential in the pathogenesis of hepatic encephalopathy, the neuropsychiatric syndrome associated with progressive liver disease. Considering the growing burden of NAFLD, the morbidity from cognitive impairment is expected to have huge societal and economic impact. The present paper provides a review of the available evidence for cognitive dysfunction in NAFLD and outlines its possible mechanisms. Moreover, the clinical challenges of characterizing and diagnosing cognitive dysfunction in NAFLD are discussed.

The Psychometric Hepatic Encephalopathy Syndrome score does not correlate with blood ammonia, endotoxins or markers of inflammation in patients with cirrhosis.

The pathogenesis of hepatic encephalopathy (HE) remains unclear but impaired clearance of gut-derived neurotoxins and increased systemic inflammation are thought to play key roles. The diagnosis is based on detection of neurophysiological and neuropsychometric abnormalities. The Psychometric Hepatic Encephalopathy Score (PHES) have been found to correlate with markers of systematic inflammation including interleukin 6, C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α). This study explores the associations between the PHES score and systemic inflammation, endotoxins and disease severity using baseline data from a trial involving patients with cirrhosis and minimal or no HE (NCT01769040). Arterial blood was obtained during hepatic vein catheterization, from 54 patients [median age 55 (range, 33-70) years; 83% men] with decompensated but stable cirrhosis. None had clinical evidence of HE but 34 (55.6%) had an abnormal PHES score indicating the presence of minimal HE. Relationships were sought between the PHES score and markers of systemic inflammation, high sensitivity-CRP, cytokines (SDF-1α, TGF-b1, IP-10, IL-6, 10 and 18, and TNF-α; lipopolysaccharide (LPS), the lipopolysaccharide binding protein (LBP) and soluble CD14 (sCD14); and the blood ammonia. No significant relationships were found between the PHES score and any of the variables tested with the single exception of the correlation with serum IL-6 (r=-0.29, 95% confidence interval, -0.53 to -0.02, P=0.031). No independent predictors of the PHES score were identified in regression analyses. No predictive associations were identified between the PHES scores and circulating blood ammonia, endotoxins, or markers of systemic inflammation in this patient population.

Regulatory Mechanism of MicroRNA-30b on Neonatal Hypoxic-Ischemic Encephalopathy (HIE)

ObjectiveThis study is to investigate the role of microRNA (miR)-30b in the pathogenesis of hypoxic-ischemic encephalopathy (HIE) in neonates. MethodsTotally 26 cases of neonatal HIE were included in this study. The protein expression levels of CD26P and PAI-1 were detected with ELISA. Serum levels of miR-30b and PAI-1 mRNA was measured by quantitative real-time PCR. Human brain microvascular endothelial cells (HBMECs) were cultured under hypoxic condition, and the intracellular expression levels of miR-30b and PAI-1 were evaluated. Dual-luciferase reporter assay was performed to confirm the interaction between miR-30b and PAI-1. ResultsCompared with the control group, both the mRNA and protein expression levels of PAI-1 in the serum were up-regulated in the neonates with HIE, together with up-regulated serum CD26P levels. However, the serum expression level of miR-30b was down-regulated in neonatal HIE. In hypoxia-induced HBMECs, the mRNA and protein expression levels of PAI-1 were significantly up-regulated, while the miR-30b expression level was significantly down-regulated. Dual-luciferase reporter assay showed that PAI-1 was the direct target of miR-30b. ConclusionNeonatal HIE is accompanied with abnormal platelet activation, significantly up-regulated serum PAI-1 expression levels, and down-regulated miR-30b expression. MiR-30b might regulate the disease pathogenesis and immune responses via modulating PAI-1.

Sepsis-Associated Encephalopathy: Insight into Injury and Pathogenesis.

Sepsis-associated encephalopathy causes long-term health problems in patients with sepsis. This review explores the pathogenesis of sepsis-associated encephalopathy, including its effects on the blood-brain barrier, microglia activation, mitochondrial dysfunction, the inflammatory medium and neurotransmitters and its roles in amino acid balance disorders, hyperammonemia, and intestinal flora imbalance. Understanding the etiology of sepsis-associated encephalopathy may allow the development of adjunctive therapies targeting its underlying mechanism and help develop preventative strategies.

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

BackgroundBlood-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.MethodsFour 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.ResultsDuring our investigations, the expression levels of miR-181b, p-JAK2, p-STAT3, and C/EBPβ 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.ConclusionsOur 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.

Lipin1 Is Involved in the Pathogenesis of Diabetic Encephalopathy through the PKD/Limk/Cofilin Signaling Pathway.

Diabetic encephalopathy is a type of central diabetic neuropathy resulting from diabetes mainly manifested as cognitive impairments. However, its underlying pathogenesis and effective treatment strategies remain unclear. In the present study, we investigated the effect of Lipin1, a phosphatidic acid phosphatase enzyme, on the pathogenesis of diabetic encephalopathy. We found that in vitro, Lipin1 exerts protective effects on high glucose-induced reductions of PC12 cell viability, while in vivo, Lipin1 is downregulated within the CA1 hippocampal region in a type I diabetes rat model. Increased levels of Lipin1 within the CA1 region are accompanied with protective effects including amelioration of dendritic spine and synaptic deficiencies, phosphorylation of the synaptic plasticity-related proteins, LIM kinase 1 (p-limk1) and cofilin, as well as increases in the synthesis of diacylglycerol (DAG), and the expression of phosphorylated protein kinase D (p-PKD). These effects are associated with the rescue of cognitive disorders as shown in this rat model of diabetes. In contrast, knockdown of Lipin1 within the CA1 region enhanced neuronal abnormalities and the genesis of cognitive impairment in rats. These results suggest that Lipin1 may exert neuroprotective effects involving the PKD/Limk/Cofilin signaling pathway and may serve as a potential therapeutic target for diabetic encephalopathy.