Ethanol Exposure Induces Microglia Activation and Neuroinflammation through TLR4 Activation and SENP6 Modulation in the Adolescent Rat Hippocampus

SENP6 restricts the IFN-I-induced signaling pathway and antiviral activity by deSUMOylating USP8

Type I interferon (IFN-I) exhibits broad-spectrum antiviral properties and is commonly employed in clinical for the treatment of viral infections. In this study, we unveil SENP6 as a potent regulator of IFN-I antiviral activity. SENP6 does not impact the production of IFN-I induced by viruses but rather modulates IFN-I-activated signaling. Mechanistically, SENP6 constitutively interacts with USP8 and inhibits the SUMOylation of USP8, consequently restricting the interaction between USP8 and IFNAR2. The dissociation of USP8 from IFNAR2 enhances IFNAR2 ubiquitination and degradation, thus attenuating IFN-I antiviral activity. Correspondingly, the downregulation of SENP6 promotes the interaction between USP8 and IFNAR2, leading to a reduction in IFNAR2 ubiquitination and, consequently, an enhancement in IFN-I-induced signaling. This study deciphers a critical deSUMOylation-deubiquitination crosstalk that finely regulates the IFN-I response to viral infection.

SENP1 regulates intermittent hypoxia-induced microglia mediated inflammation and cognitive dysfunction via wnt/β-catenin pathway

Obstructive sleep apnea syndrome (OSAS), characterized by repeated narrow or collapse of the upper airway during sleep, resulting in periodic reductions or cessations in ventilation, consequent hypoxia, hypercapnia, increased sympathetic activity and sleep fragmentation, places a serious burden on society and health care. Intermittent hypoxia (IH), which cause central nervous system (CNS) inflammation, and ultimately lead to neuropathy, is thought to be a crucial contributor to cognitive impairment in OSAS. Wnt signaling pathway exerts an important role in the regulation of CNS disorders. Particularly, it may be involved in the regulation of neuroinflammation and cognitive dysfunction. However, its underlying mechanism remains poorly understood. Accumulating evidence demonstrated that Wnt signaling pathway may inhibited in a variety of neurological disorders. Recently studies revealed that SUMOylation was participated in the regulation of neuroinflammation. Members of Wnt/β-catenin pathway may be targets of SUMOylation. In vitro and in vivo molecular biology experiments explored the regulatory mechanism of SUMOylation on Wnt/β-catenin in IH-induced neuroinflammation and neuronal injury, which demonstrated that IH induced the SUMOylation of β-catenin, microglia mediated inflammation and neuronal damage. Moreover, SENP1 regulated the de-SUMOylation of β-catenin, triggered Wnt/β-catenin pathway, and alleviated neuroinflammation and neuronal injury, thus improving IH-related mice cognitive dysfunction.

Ethanol's impact on the brain: a neurobiological perspective on the mechanisms of memory impairment

Alcohol consumption is known to have detrimental effects on memory function, with various studies implicating ethanol in the impairment of cognitive processes related to memory retention and retrieval. This review aims to elucidate the complex neurobiological mechanisms underlying ethanol-induced memory impairment. Through a thorough search of existing literature using electronic databases, relevant articles focusing on the neurobiological mechanisms of ethanol on memory were identified and critically evaluated. This review focuses on the molecular and neural pathways through which ethanol exerts its effects on memory formation, consolidation, and recall processes. Key findings from the included studies shed light on the impact of ethanol on neurotransmitter systems, synaptic plasticity, and neuroinflammation in relation to memory impairment. This review contributes to a better understanding of the intricate mechanisms by which alcohol impairs memory function, offering insights for future research directions and the development of targeted interventions to alleviate these cognitive impairments.

NF-κB/NLRP3 Translational Inhibition by Nanoligomer Therapy Mitigates Ethanol and Advanced Age-Related Neuroinflammation

Binge alcohol use is increasing among aged adults (>65 years). Alcohol-related toxicity in aged adults is associated with neurodegeneration, yet the molecular underpinnings of age-related sensitivity to alcohol are not well described. Studies utilizing rodent models of neurodegenerative disease reveal heightened activation of Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and Nod like receptor 3 (NLRP3) mediate microglia activation and associated neuronal injury. Our group, and others, have implicated hippocampal-resident microglia as key producers of inflammatory mediators, yet the link between inflammation and neurodegeneration has not been established in models of binge ethanol exposure and advanced age. Here, we report binge ethanol increased the proportion of NLRP3+ microglia in the hippocampus of aged (18-20 months) female C57BL/6N mice compared to young (3-4 months). In primary microglia, ethanol-induced expression of reactivity markers and NLRP3 inflammasome activation were more pronounced in microglia from aged mice compared to young. Making use of an NLRP3-specific inhibitor (OLT1177) and a novel brain-penetrant Nanoligomer that inhibits NF-κB and NLRP3 translation (SB_NI_112), we find ethanol-induced microglial reactivity can be attenuated by OLT1177 and SB_NI_112 in microglia from aged mice. In a model of intermittent binge ethanol exposure, SB_NI_112 prevented ethanol-mediated microglia reactivity, IL-1β production, and tau hyperphosphorylation in the hippocampus of aged mice. These data suggest early indicators of neurodegeneration occurring with advanced age and binge ethanol exposure are NF-κB- and NLRP3-dependent. Further investigation is warranted to explore the use of targeted immunosuppression via Nanoligomers to attenuate neuroinflammation after alcohol consumption in the aged.

Binge ethanol exposure in advanced age elevates neuroinflammation and early indicators of neurodegeneration and cognitive impairment in female mice

Binge drinking is rising among aged adults (>65 years of age), however the contribution of alcohol misuse to neurodegenerative disease development is not well understood. Both advanced age and repeated binge ethanol exposure increase neuroinflammation, which is an important component of neurodegeneration and cognitive dysfunction. Surprisingly, the distinct effects of binge ethanol exposure on neuroinflammation and associated degeneration in the aged brain have not been well characterized. Here, we establish a model of intermittent binge ethanol exposure in young and aged female mice to investigate the effects of advanced age and binge ethanol on these outcomes. Following intermittent binge ethanol exposure, expression of pro-inflammatory mediators (tnf-α, il-1β, ccl2) was distinctly increased in isolated hippocampal tissue by the combination of advanced age and ethanol. Binge ethanol exposure also increased measures of senescence, the nod like receptor pyrin domain containing 3 (NLRP3) inflammasome, and microglia reactivity in the brains of aged mice compared to young. Binge ethanol exposure also promoted neuropathology in the hippocampus of aged mice, including tau hyperphosphorylation and neuronal death. We further identified advanced age-related deficits in contextual memory that were further negatively impacted by ethanol exposure. These data suggest binge drinking superimposed with advanced age promotes early markers of neurodegenerative disease development and cognitive decline, which may be driven by heightened neuroinflammatory responses to ethanol. Taken together, we propose this novel exposure model of intermittent binge ethanol can be used to identify therapeutic targets to prevent advanced age- and ethanol-related neurodegeneration.

Acute and Chronic Ethanol Effects during Adolescence on Neuroimmune Responses: Consequences and Potential Pharmacologic Interventions

Heavy ethanol consumption during adolescence has been linked to neuroimmune response dysregulation and cognitive deficits in the developing adolescent brain. During adolescence, the brain is particularly susceptible to the pharmacological effects of ethanol that are induced by acute and chronic bouts of exposure. Numerous preclinical rodent model studies have used different ethanol administration techniques, such as intragastric gavage, self-administration, vapor, intraperitoneal, and free access, and while most models indicated proinflammatory neuroimmune responses in the adolescent brain, there are various factors that appear to influence this observation. This review synthesizes the most recent findings of the effects of adolescent alcohol use on toll-like receptors, cytokines, and chemokines, as well as the activation of astrocytes and microglia with an emphasis on differences associated with the duration of ethanol exposure (acute vs. chronic), the amount of exposure (e.g., dose or blood ethanol concentrations), sex differences, and the timing of the neuroimmune observation (immediate vs. persistent). Finally, this review discusses new therapeutics and interventions that may ameliorate the dysregulation of neuroimmune maladaptations after ethanol exposure.

SUMO specific peptidase 6 regulates the crosstalk between podocytes and glomerular endothelial cells in diabetic kidney disease

There is increasing evidence that the crosstalk between podocytes and glomerular endothelial cells (GECs) exacerbates the progression of diabetic kidney disease (DKD). Here, we investigated the underlying role of SUMO specific peptidase 6 (SENP6) in this crosstalk. In the diabetic mice, SENP6 was decreased in glomerular tissues and its knockdown further exacerbated glomerular filtration barrier injury. In the mouse podocyte cell line MPC5 cells, SENP6 overexpression reversed HG-induced podocyte loss by suppressing the activation of Notch1 signaling. Notch1 intracellular domain (N1ICD) is the active form of Notch1. SENP6 upregulated the ubiquitination of N1ICD by deSUMOylating Notch1, thereby reducing N1ICD and suppressing Notch1 signaling activation in MPC5 cells. Endothelin-1 (EDN1) is a protein produced by podocytes and has been reported to promote GEC dysfunction. The supernatant from HG-treated MPC5 cells induced mitochondrial dysfunction and surface layer injury in GECs, and the supernatant from SENP6-deficient podocytes further exacerbated the above GEC dysfunction, while this trend was reversed by an EDN1 antagonist. The following mechanism study showed that SENP6 deSUMOylated KDM6A (a histone lysine demethylase) and then decreased the binding potency of KDM6A to EDN1. The latter led to the upregulation of H3K27me2 or H3K27me3 of EDN1 and suppressed its expression in podocytes. Taken together, SENP6 suppressed the HG-induced podocyte loss and ameliorated GEC dysfunction caused by crosstalk between podocytes and GECs, and the protective effect of SENP6 on DKD is attributed to its deSUMOylation activity.

Astrocytic Responses to Binge Alcohol Intake in the Mouse Hindbrain

Ethanol is the most commonly used toxic chemical in human cultures. Ethanol predominantly damages the brain causing various neurological disorders. Astrocytes are important cellular targets of ethanol in the brain and are involved in alcoholic symptoms. Recent studies have revealed the diversity of astrocyte populations in the brain. However, it is unclear how the different astrocyte populations respond to an excess of ethanol. Here we examined the effect of binge ethanol levels on astrocytes in the mouse brainstem and cerebellum. Ethanol administration for four consecutive days increased the glial fibrillary acidic protein (GFAP)-immunoreactive signals in the spinal tract of the trigeminal nerve (stTN) and reticular nucleus (RN). Another astrocyte marker, aquaporin 4 (AQP4), was also increased in the stTN with a pattern similar to that of GFAP. However, in the RN, the immunoreactive signals of AQP4 were different from that of GFAP and were not changed by ethanol administration. In the cerebellum, GFAP-positive signals were found in all four astrocytic populations, and those in the Bergmann glia were selectively eliminated by ethanol administration. We next examined the effect of estradiol on the ethanol-induced changes in astrocytic immunoreactive signals. The administration of estradiol alone increased the AQP4-immunoreactivity in the stTN with a pattern similar to that of ethanol, whereas the co-administration of estradiol and ethanol suppressed the intensity of the AQP4-positive signals. Thus, binge levels of ethanol intake selectively affect astrocyte populations in the brainstem and cerebellum. Sex hormones can affect the ethanol-induced neurotoxicity via modulation of astrocyte reactivity.

The role of SUMOylation in the neurovascular dysfunction after acquired brain injury

Acquired brain injury (ABI) is the most common disease of the nervous system, involving complex pathological processes, which often leads to a series of nervous system disorders. The structural destruction and dysfunction of the Neurovascular Unit (NVU) are prominent features of ABI. Therefore, understanding the molecular mechanism underlying NVU destruction and its reconstruction is the key to the treatment of ABI. SUMOylation is a protein post-translational modification (PTM), which can degrade and stabilize the substrate dynamically, thus playing an important role in regulating protein expression and biological signal transduction. Understanding the regulatory mechanism of SUMOylation can clarify the molecular mechanism of the occurrence and development of neurovascular dysfunction after ABI and is expected to provide a theoretical basis for the development of potential treatment strategies. This article reviews the role of SUMOylation in vascular events related to ABI, including NVU dysfunction and vascular remodeling, and puts forward therapeutic prospects.

n-3 polyunsaturated fatty acids improve depression-like behavior by inhibiting hippocampal neuroinflammation in mice via reducing TLR4 expression

INTRODUCTION

n-3 polyunsaturated fatty acids (PUFAs) are believed to be implicated in the pathogenesis of many inflammation-related diseases, including depression.

METHODS

The mouse model of depression was established through chronic unpredictable mild stress (CUMS), the mice were intervened with n-3 PUFAs, and then the expression of toll-like receptor 4 (TLR4) was stimulated with lipopolysaccharides (LPS). Tail suspension test (TST), forced swimming test (FST) and sucrose preference test were performed to monitor the depression behavior of mice. Microglia activation was detected by Iba1 immunofluorescence, and neuronal injury was detected by Nissl staining. Concentrations of tumor necrosis factor (TNF)-α, Interleukin (IL)-6 and IL-1β in the hippocampus were assessed via enzyme linked immunosorbent assay (ELISA). Quantitative real time polymerase chain reaction was used to detect IL-6, IL-1β and TNF-α messenger RNA levels. Western blot was utilized for detection of TLR4 protein expression.

RESULTS

CUMS significantly reduced the sucrose preference in mice, while increased the immobility time in FST and TST. Moreover, CUMS significantly aggravated microglia activation and neuronal damage in mice and increased the levels of IL-6, IL-1β and TNF-α in hippocampal tissues, however, intervention with n-3 PUFAs could improve the above effects. Further, the increased TLR4 induced by LPS partially reversed the inhibition of n-3 PUFAs on depression-like behaviors, microglial activation and inflammatory injury of hippocampal neurons.

CONCLUSION

n-3 PUFAs may ameliorate depression-like behaviors via reducing hippocampal neuroinflammation in CUMS-induced mice by regulating TLR4 expression, suggesting that n-3 PUFAs may be an effective antidepressant, which provides evidence for future treatment of depression.

Mesenchymal Stem Cells Improve Cognitive Impairment and Reduce Aβ Deposition via Promoting AQP4 Polarity and Relieving Neuroinflammation in Rats With Chronic Hypertension-Induced Cerebral Small-Vessel Disease

Cerebral small-vessel disease (CSVD) is the main cause of vascular cognitive impairment (VCI), and the accumulation of amyloid β-protein (Aβ) may be significantly involved in CSVD-induced VCI. The imbalance between Aβ production and clearance is believed to be an important pathological mechanism of Aβ deposition in Alzheimer disease. In this study, we aimed to disclose the roles of aquaporin 4 (AQP4) and neuroinflammation in CSVD, which were the key factors for Aβ clearance and production, respectively, and the effect of mesenchymal stem cells (MSCs) on Aβ deposition and these two factors. The stroke-prone renovascular hypertensive (RHRSP) rats were grouped and received MSC and MSC + AS1517499 (an inhibitor of pSTAT6). The latter was used to explore the underlying mechanism. The cognitive function, white matter lesions, Aβ expression, expression, and polarity of AQP4, neuroinflammation and the STAT6 pathway were investigated. Compared with sham-operated rats, RHRSP rats showed spatial cognitive impairment, white matter lesions and Aβ deposition. Moreover, AQP4 polarity disorder and neuroinflammatory activation were found, which were linked to Aβ deposition. Treatment with MSCs markedly improved cognitive tasks and reduced Aβ deposition but failed to reduce white-matter lesions. Furthermore, MSCs not only promoted AQP4 polarity but also alleviated neuroinflammation probably through the STAT6 pathway. The present study demonstrated that Aβ deposition, AQP4 polarity disorder and neuroinflammation might be involved in CSVD and the regulatory effects of MSCs on them suggested potential therapeutic value for CSVD.

Cholinergic and Neuroimmune Signaling Interact to Impact Adult Hippocampal Neurogenesis and Alcohol Pathology Across Development

Alcohol (ethanol) use and misuse is a costly societal issue that can affect an individual across the lifespan. Alcohol use and misuse typically initiates during adolescence and generally continues into adulthood. Not only is alcohol the most widely abused drug by adolescents, but it is also one of the most widely abused drugs in the world. In fact, high rates of maternal drinking make developmental ethanol exposure the most preventable cause of neurological deficits in the Western world. Preclinical studies have determined that one of the most consistent effects of ethanol is its disruption of hippocampal neurogenesis. However, the severity, persistence, and reversibility of ethanol’s effects on hippocampal neurogenesis are dependent on developmental stage of exposure and age at assessment. Complicating the neurodevelopmental effects of ethanol is the concurrent development and maturation of neuromodulatory systems which regulate neurogenesis, particularly the cholinergic system. Cholinergic signaling in the hippocampus directly regulates hippocampal neurogenesis through muscarinic and nicotinic receptor actions and indirectly regulates neurogenesis by providing anti-inflammatory regulatory control over the hippocampal environmental milieu. Therefore, this review aims to evaluate how shifting maturational patterns of the cholinergic system and its regulation of neuroimmune signaling impact ethanol’s effects on adult neurogenesis. For example, perinatal ethanol exposure decreases basal forebrain cholinergic neuron populations, resulting in long-term developmental disruptions to the hippocampus that persist into adulthood. Exaggerated neuroimmune responses and disruptions in adult hippocampal neurogenesis are evident after environmental, developmental, and pharmacological challenges, suggesting that perinatal ethanol exposure induces neurogenic deficits in adulthood that can be unmasked under conditions that strain neural and immune function. Similarly, adolescent ethanol exposure persistently decreases basal forebrain cholinergic neuron populations, increases hippocampal neuroimmune gene expression, and decreases hippocampal neurogenesis in adulthood. The effects of neither perinatal nor adolescent ethanol are mitigated by abstinence whereas adult ethanol exposure-induced reductions in hippocampal neurogenesis are restored following abstinence, suggesting that ethanol-induced alterations in neurogenesis and reversibility are dependent upon the developmental period. Thus, the focus of this review is an examination of how ethanol exposure across critical developmental periods disrupts maturation of cholinergic and neuroinflammatory systems to differentially affect hippocampal neurogenesis in adulthood.

Dexpanthenol may protect the brain against lipopolysaccharide induced neuroinflammation via anti-oxidant action and regulating CREB/BDNF signaling

BACKGROUND

Neuroinflammation plays an important role in the pathogenesis of many psychiatric and neurodegenerative diseases. Dexpanthenol (Dex) is an alcoholic analogue of pantothenic acid with antioxidant, anti-inflammatory and anti-apoptotic properties. The purpose of this study was to determine the effect of dexpanthenol on lipopolysaccharide (LPS)-induced brain injury, specifically on the CREB/BDNF pathway.

METHOD

Thirty-two rats were distributed into four groups: control, LPS, LPS + Dex and Dex groups. In this study, using real-time PCR, we evaluated changes in the gene expression of BDNF and CREB in the hippocampal brain tissue. Total antioxidant status (TAS), total oxidant status (TOS) were measured spectrophotometrically in the cortical tissue. Brain and cerebellum tissues were collected for histopathological examination and immunohistochemical assessment of tumor necrosis factor alpha (TNF-α) and caspase-3 (Cas-3).

RESULT AND DISCUSSION

In the LPS + Dex group, TAS levels were significantly higher while TOS and OSI levels were significantly lower than the LPS group. In the LPS + Dex and Dex group, BDNF relative mRNA expressions were significantly higher than the LPS group. The levels of CREB relative mRNA expression in LPS and LPS + Dex group were significantly lower than the control group. An increased expression of Cas-3 and TNF-α in the LPS group and a decreased expression in the LPS + Dex group were observed in the immunohistochemical examination.

CONCLUSION

According to these results, it may be considered that CREB-mediated BDNF synthesis may play a role in the etiopathogenesis of neuroinflammation. By regulating these changes with dexpanthenol treatment, a positive contribution may be made to neuroinflammation treatment.

Astrogliosis and compensatory neurogenesis after the first ethanol binge drinking-like exposure in the adolescent rat

BACKGROUND

Multiple ethanol binge drinking-like exposures during adolescence in the rat induce neuroinflammation, loss of neurogenesis, and cognitive deficits in adulthood. Interestingly, the first ethanol binge drinking-like exposure during adolescence also induces short- term impairments in cognition and synaptic plasticity in the hippocampus though the cellular mechanisms of these effects are unclear. Here, we sought to determine which of the cellular effects of ethanol might play a role in the disturbances in cognition and synaptic plasticity observed in the adolescent male rat after two binge-like ethanol exposures.

METHODS

Using immunochemistry, we measured neurogenesis, neuronal loss, astrogliosis, neuroinflammation, and synaptogenesis in the hippocampus of adolescent rats 48 h after two binge-like ethanol exposures (3 g/kg, i.p., 9 h apart). We used flow cytometry to analyze activated microglia and identify the TLR4-expressing cell types.

RESULTS

We detected increased hippocampal doublecortin immunoreactivity in the subgranular zone (SGZ) of the dentate gyrus (DG), astrogliosis in the SGZ, and a reduced number of mature neurons in the DG and in CA3, suggesting compensatory neurogenesis. Synaptic density decreased in the stratum oriens of CA1 revealing structural plasticity. There was no change in microglial TLR4 expression or in the number of activated microglia, suggesting a lack of neuroinflammatory processes, although neuronal TLR4 was decreased in CA1 and DG.

CONCLUSIONS

Our findings demonstrate that the cognitive deficits associated with hippocampal synaptic plasticity alterations that we previously characterized 48 h after the first binge-like ethanol exposures are associated with hippocampal structural plasticity, astrogliosis, and decreased neuronal TLR4 expression, but not with microglia reactivity.

Epigenetics of alcohol use disorder-A review of recent advances in DNA methylation profiling

Alcohol use disorder (AUD) is a major contributor to morbidity and mortality worldwide. Although there is a heritable component, the etiology of AUD is complex and can involve environmental exposures like trauma and can be associated with many different patterns of alcohol consumption. Epigenetic modifications, which can mediate the influence of genetic variants and environmental variables on gene expression, have emerged as an important area of AUD research. Over the past decade, the number of studies investigating AUD and DNA methylation, a form of epigenetic modification, has grown rapidly. Yet we are still far from understanding how DNA methylation contributes to or reflects aspects of AUD. In this paper, we reviewed studies of DNA methylation and AUD and discussed how the field has evolved. We found that global DNA and candidate DNA methylation studies did not produce replicable results. To assess whether findings of epigenome-wide association studies (EWAS) were replicated, we aggregated significant findings across studies and identified 184 genes and 15 gene ontological pathways that were differentially methylated in at least two studies and four genes and three gene ontological pathways that were differentially methylated in three studies. These genes and pathways repeatedly found enrichment of immune processes, which is in line with recent developments suggesting that the immune system may be altered in AUD. Finally, we assess the current limitations of studies of DNA methylation and AUD and make recommendations on how to design future studies to resolve outstanding questions.

Primed for addiction: A critical review of the role of microglia in the neurodevelopmental consequences of adolescent alcohol drinking

Alcohol is one of the most widely used recreational substances worldwide, with drinking frequently initiated during adolescence. The developmental state of the adolescent brain makes it vulnerable to initiating alcohol use, often in high doses, and particularly susceptible to alcohol-induced brain changes. Microglia, the brain parenchymal macrophages, have been implicated in mediating some of these effects, though the role that these cells play in the progression from alcohol drinking to dependence remains unclear. Microglia are uniquely positioned to sense and respond to central nervous system insult, and are now understood to exhibit innate immune memory, or "priming," altering their future functional responses based on prior exposures. In alcohol use disorders (AUDs), the role of microglia is debated. Whereas microglial activation can be pathogenic, contributing to neuroinflammation, tissue damage, and behavioral changes, or protective, it can also engage protective functions, providing support and mediating the resolution of damage. Understanding the role of microglia in adolescent AUDs is complicated by the fact that microglia are thought to be involved in developmental processes such as synaptic refinement and myelination, which underlie the functional maturation of multiple brain systems in adolescence. Thus, the role microglia play in the impact of alcohol use in adolescence is likely multifaceted. Long-term sequelae may be due to a failure to recover from EtOH-induced tissue damage, altered neurodevelopmental trajectories, and/or persistent changes to microglial responsivity and function. Here, we review critically the literature surrounding the effects of alcohol on microglia in models of adolescent alcohol misuse. We attempt to disentangle what is known about microglia from other neuroimmune effectors, to which we apply recent discoveries on the role of microglia in development and plasticity. Considered altogether, these studies challenge assumptions that proinflammatory microglia drive addiction. Alcohol priming microglia and thereby perturbing their homeostatic roles in neurodevelopment, especially during critical periods of plasticity such as adolescence, may have more serious implications for the neuropathogenesis of AUDs in adolescents.

Lactobacillus casei relieves liver injury by regulating immunity and suppression of the enterogenic endotoxin-induced inflammatory response in rats cotreated with alcohol and iron

Excessive alcohol and iron intake can reportedly cause liver damage. In the present study, we investigated the effect of Lactobacillus casei on liver injury in rats co-exposed to alcohol and iron and evaluated its possible mechanism. Sixty male Wistar rats were randomly divided into three groups for 12 weeks: the Control group (administered normal saline by gavage and provided a normal diet); alcohol +iron group (Model group, treated with alcohol [3.5-5.3 g/kg/day] by gavage and dietary iron [1,500 mg/kg]); Model group supplemented with L. casei (8 × 108 CFU kg-1 day-1) (L. casei group). Using hematoxylin and eosin (HE) staining and transmission electron microscopy, we observed that L. casei supplementation could alleviate disorders associated with lipid metabolism, inflammation, and intestinal mucosal barrier injury. Moreover, levels of serum alanine aminotransferase, gamma-glutamyl transferase, triglyceride (TG), and hepatic TG were significantly increased in the model group; however, these levels were significantly decreased following the 12-week L. casei supplementation. In addition, we observed notable improvements in intestinal mucosal barrier function and alterations in T lymphocyte subsets and natural killer cells in L. casei-treated rats when compared with the model group. Furthermore, L. casei intervention alleviated serum levels of tumor necrosis factor-α and interleukin-1β, accompanied by decreased serum endotoxin levels and downregulated expression of toll-like receptor 4 and its related molecules MyD88, nuclear factor kappa-B p65, and TNF-α. Accordingly, supplementation with L. casei could effectively improve liver injury induced by the synergistic interaction between alcohol and iron. The underlying mechanism for this improvement may be related to immune regulation and inhibition of enterogenic endotoxin-mediated inflammation.

Caffeine consumption attenuates ethanol-induced inflammation through the regulation of adenosinergic receptors in the UChB rats cerebellum

Caffeine consumption is able to interfere in cellular processes related to inflammatory mechanisms by acting through the adenosinergic system. This study aimed to recognize alterations related to adenosinergic system and inflammatory process in the cerebellum of University of Chile Bibulous (UChB) rats after the consumption of ethanol and caffeine. UChB and Wistar rats, males at 5 months old, were divided into the groups (n = 15/group): (i) Control (Wistar rats receiving water); (ii) Ethanol group (UChB rats receiving ethanol solution at 10%) and (iii) Ethanol+caffeine group (UChB rats receiving ethanol solution at 10% added of 3 g/L of caffeine). The cerebellar tissue was collected and processed for immunohistochemistry, Reverse transcription polymerase chain reaction (RT-PCR) and western blotting techniques for the adenosinergic receptors A1 and A2a and inflammatory markers, including Nuclear factor kappa B (NFkB), TLR4, TLR2, MyD88, TNF-α, COX-2, iNOS and microglial marker Iba-1. Results showed ethanol and caffeine consumption differentially altering the immunolocalization of adenosinergic receptors and inflammatory markers in the cerebellar tissue. The A2a receptor was overexpressed in the Ethanol group and was evident in the glial cells. The Ethanol group had increased protein levels for NFκB and TLR4, expressively in Bergmann glia and Purkinje cells. Caffeine reduced the expression of these markers to levels similar to those found in the Control group. The A1 gene was upregulated the Ethanol group, but not its protein levels, suggesting post-transcriptional interference. In conclusion, caffeine seems to attenuate ethanol-induced inflammation in the cerebellum of UChB rats through the A1 and A2a modulation, playing a neuroprotective role in the chronic context of ethanol consumption.

Alcohol-Induced Blood-Brain Barrier Impairment: An In Vitro Study

In recent years, alcohol abuse has dramatically grown with deleterious consequence for people's health and, in turn, for health care costs. It has been demonstrated, in humans and animals, that alcohol intoxication induces neuroinflammation and neurodegeneration thus leading to brain impairments. Furthermore, it has been shown that alcohol consumption is able to impair the blood-brain barrier (BBB), but the molecular mechanisms underlining this detrimental effect have not been fully elucidated. For this reason, in this study we investigated the effects of alcohol exposure on a rat brain endothelial (RBE4) cell line, as an in vitro-validated model of brain microvascular endothelial cells. To assess whether alcohol caused a concentration-related response, the cells were treated at different times with increasing concentrations (10-1713 mM) of ethyl alcohol (EtOH). Microscopic and molecular techniques, such as cell viability assay, immunofluorescence and Western blotting, were used to examine the mechanisms involved in alcohol-induced brain endothelial cell alterations including tight junction distribution, apoptosis, and reactive oxygen species production. Our findings clearly demonstrate that alcohol causes the formation of gaps between cells by tight junction disassembly, triggered by the endoplasmic reticulum and oxidative stress, highlighted by GRP78 chaperone upregulation and increase in reactive oxygen species production, respectively. The results from this study shed light on the mechanisms underlying alcohol-induced blood-brain barrier dysfunction and a better understanding of these processes will allow us to take advantage of developing new therapeutic strategies in order to prevent the deleterious effects of alcohol.

Microglia-associated neuroinflammation is a potential therapeutic target for ischemic stroke

Microglia-associated neuroinflammation plays an important role in the pathophysiology of ischemic stroke. Microglial activation and polarization, and the inflammatory response mediated by these cells play important roles in the development, progression and outcome of brain injury after ischemic stroke. Currently, there is no effective strategy for treating ischemic stroke in clinical practice. Therefore, it is clinically important to study the role and regulation of microglia in stroke. In this review, we discuss the involvement of microglia in the neuroinflammatory process in ischemic stroke, with the aim of providing a better understanding of the relationship between ischemic stroke and microglia.

Liquiritigenin Decreases Aβ Levels and Ameliorates Cognitive Decline by Regulating Microglia M1/M2 Transformation in AD Mice

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases and is currently incurable. Amyloid β protein (Aβ) deposition is the main pathogenesis of AD, and many studies have shown that Aβ accumulation is toxic to neurons, leading to the inflammatory reaction, neuronal apoptosis, and neurofibrillary tangles. Thus, reducing Aβ levels might be a potential therapeutic strategy for AD. Liquiritigenin (LG), a dihydroflavone monomer compound extracted from natural plant licorice, has a variety of biological activities such as antioxidant, anti-tumor, anti-inflammatory and anti-virus. However, the exact function of LG in the pathogenesis of AD is elusive. Here, we reported that LG could significantly attenuate neuronal apoptosis in Aβ-induced N2A cells and APP/PS1 transgenic mice. Our in vivo and in vitro studies revealed that LG could alleviate the inflammation response, reflected by the reduction of NLRP3 and cleaved caspase-1. Meanwhile, we also found that LG was able to shift M1 type microglia towards M2 type microglia in Aβ-induced BV2 cells and AD mice. Furthermore, LG could reduce the Aβ levels by decreasing APP processing and accelerating Aβ clearance in AD mice. More importantly, daily treatment of LG (30 mg/kg day) for 90 days dramatically ameliorated the spatial learning and memory of AD mice. Taken together, these results suggest that LG can reduce the Aβ levels by regulating the M1/M2 transformation of microglia, thereby reversing memory decline during AD development, suggesting that LG may be a potential therapeutic agent for treating AD.