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Sepsis is a life-threatening organ dysfunction triggered by a dysregulated host immune response to eliminate an infection. After the host immune response is activated, a complex, dynamic, and time-dependent process is triggered. This process promotes the production of inflammatory mediators, including acute-phase proteins, complement system proteins, cytokines, chemokines, and antimicrobial peptides, which are required to initiate an inflammatory environment for eliminating the invading pathogen. The physiological response of this sepsis-induced systemic inflammation can affect blood–brain barrier (BBB) function; subsequently, endothelial cells produce inflammatory mediators, including cytokines, chemokines, and matrix metalloproteinases (MMPs) that degrade tight junction (TJ) proteins and decrease BBB function. The resulting BBB permeability allows peripheral immune cells from the bloodstream to enter the brain, which then release a range of inflammatory mediators and activate glial cells. The activated microglia and astrocytes release reactive oxygen species (ROS), cytokines, chemokines, and neurochemicals, initiate mitochondrial dysfunction and neuronal damage, and exacerbate the inflammatory milieu in the brain. These changes trigger sepsis-associated encephalopathy (SAE), which has the potential to increase cognitive deterioration and susceptibility to cognitive decline later in life.

Maternal deprivation (MD) is known to be related to long-term changes that could influence the onset of psychiatric disorders. Studies have demonstrated that early life stress makes the cells in the brain more susceptible to subsequent stressors. To test it, we used an animal model of MD conducted from postnatal day (PND) 1 to 10. Deprived and non-deprived rats (control) were randomized to receive or not lipopolysaccharide (LPS) at 5 mg/kg on PND 50. The behavior and glial cells activation were evaluated in all groups from 51 to 53 PND. There was an increase in the immobility time in the MD and MD+LPS groups. The spontaneous locomotor activity was not changed between groups. We found elevated ionized calcium-binding adapter molecule 1 (Iba-1)-positive cells levels in the control+LPS and MD+LPS groups. In the MD+LPS group, it was found an increase in Iba-positive cells compared to the MD+sal group. The glial fibrillary acidic protein (GFAP)-positive cells were also increased in the MD+LPS, compared to control+sal, control+LPS, and MD+sal groups. Immune challenge by LPS in late adolescence, which was subjected to MD, did not influence the depressive-like behavior but exerted a pronounced effect in the microglial activation and astrocyte atrophy.

The microbiota-gut-brain axis is a bidirectional signaling mechanism between the gastrointestinal tract and the central nervous system. The complexity of the intestinal ecosystem is extraordinary; it comprises more than 100 trillion microbial cells that inhabit the small and large intestine, and this interaction between microbiota and intestinal epithelium can cause physiological changes in the brain and influence mood and behavior. Currently, there has been an emphasis on how such interactions affect mental health. Evidence indicates that intestinal microbiota are involved in neurological and psychiatric disorders. This review covers evidence for the influence of gut microbiota on the brain and behavior in Alzheimer disease, dementia, anxiety, autism spectrum disorder, bipolar disorder, major depressive disorder, Parkinson’s disease, and schizophrenia. The primary focus is on the pathways involved in intestinal metabolites of microbial origin, including short-chain fatty acids, tryptophan metabolites, and bacterial components that can activate the host’s immune system. We also list clinical evidence regarding prebiotics, probiotics, and fecal microbiota transplantation as adjuvant therapies for neuropsychiatric disorders.

Pneumococcal meningitis is a life-threatening infection of the central nervous system (CNS), and half of the survivors of meningitis suffer from neurological sequelae. We hypothesized that pneumococcal meningitis causes CNS inflammation via the disruption of the blood–brain barrier (BBB) and by increasing the receptor for advanced glycation end product (RAGE) expression in the brain, which causes glial cell activation, leading to cognitive impairment. To test our hypothesis, 60-day-old Wistar rats were subjected to meningitis by receiving an intracisternal injection of Streptococcus pneumoniae or artificial cerebrospinal fluid as a control group and were treated with a RAGE-specific inhibitor (FPS-ZM1) in saline. The rats also received ceftriaxone 100 mg/kg intraperitoneally, bid, and fluid replacements. Experimental pneumococcal meningitis triggered BBB disruption after meningitis induction, and FPS-ZM1 treatment significantly suppressed BBB disruption. Ten days after meningitis induction, surviving animals were free from infection, but they presented increased levels of TNF-α and IL-1β in the prefrontal cortex (PFC); high expression levels of RAGE, amyloid-β (Aβ(1–42)), and microglial cell activation in the PFC and hippocampus; and memory impairment, as evaluated by the open-field, novel object recognition task and Morris water maze behavioral tasks. Targeted RAGE inhibition was able to reduce cytokine levels, decrease the expression of RAGE and Aβ(1–42), inhibit microglial cell activation, and improve cognitive deficits in meningitis survivor rats. The sequence of events generated by pneumococcal meningitis can persist long after recovery, triggering neurocognitive decline; however, RAGE blocker attenuated the development of brain inflammation and cognitive impairment in experimental meningitis. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13311-020-00917-3) contains supplementary material, which is available to authorized users.

Alzheimer's disease (AD) and related dementias (ADRD) are still a serious global public health concern more than a century after the German neuropathologist and psychiatrist Dr. Aloysius Alzheimer described the first case. The World Health Organization (WHO) estimates that over 50 million people worldwide suffer from dementia, with AD accounting for 60-70% of all cases. In addition, the global dementia epidemic is estimated to affect 82 million individuals by 2030 and 152 million by 2050. Along with genetic factors, environmental factors, and aging also increase the risks of developing neurodegenerative disorders. For example, gut microbiota can serve as non-genetic factors that define a threshold for maintaining a homeostatic balance or developing illnesses. The scientific community has explored and identified that patients with AD often present with dysbiosis of the bowel and dysregulated gastrointestinal (GI) tract. Research describes it as a bidirectional relationship by which the brain communicates with the gut's microbiome through the vagus nerve, immune and neuroimmune systems, enteroendocrine system, neurotransmitters, branched-chain amino acids, short-chain fatty acids (SCFAs), agonists of aryl hydrocarbon receptors (AHRs), bile acids, and the hypothalamic-pituitary-adrenal (HPA) axis. In this narrative review, we explore and clarify the involvement of the microbiota-gut-brain axis in AD pathology.

In the past three decades, research on the gut microbiome and its metabolites, such as trimethylamines (TMA), trimethylamine N-oxide (TMAO), short-chain fatty acids (SCFAs), branched-chain amino acids (BCAAs), bile acids, tryptophan and indole derivatives, has attracted the attention of many scientists and industrialists. Among these metabolites, TMAO is produced from dietary choline, phosphatidylcholine, carnitine,andbetaine. TMAO and other gut metabolites, such as TMA and SCFAs, reach the brain by crossing the blood-brain barrier (BBB) and are involved in brain development, neurogenesis, and behavior. Gut-microbiota composition is influenced by diet, lifestyle, antibiotics, and age. Several studies have confirmed that altered TMAO levels contribute to metabolic, vascular, psychiatric, and neurodegenerative disorders. This review focuses on how altered TMAO levels impact oxidative stress, microglial activation, and the apoptosis of neurons, and may lead to neuroinflammation, which can subsequently result in the development of psychiatric, cognitive, and behavioral disorders.

Objectives Sepsis is a life-threatening organ dysfunction caused by a host's unregulated immune response to eliminate the infection. After hospitalization, sepsis survivors often suffer from long-term impairments in memory, attention, verbal fluency, and executive functioning. To understand the effects of sepsis and the exacerbated peripheral inflammatory response in the brain, we asked the question: What are the findings and inflammatory markers in the brains of deceased sepsis patients? To answer this question, we conducted this systematic review by the recommendations of Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Data sources Relevant studies were identified by searching the PubMed/National Library of Medicine, PsycINFO, EMBASE, Bibliographical Index in Spanish in Health Sciences, Latin American and Caribbean Health Sciences Literature, and Web of Science databases for peer-reviewed journal articles published on April 05, 2021. Study selection A total of 3,745 articles were included in the primary screening; after omitting duplicate articles, animal models, and reviews, 2,896 articles were selected for the study. These studies were selected based on the title and abstract, and 2,772 articles were still omitted based on the exclusion criteria. Data extraction The complete texts of the remaining 124 articles were obtained and thoroughly evaluated for the final screening, and 104 articles were included. Data synthesis The postmortem brain had edema, abscess, hemorrhagic and ischemic injuries, infarction, hypoxia, atrophy, hypoplasia, neuronal loss, axonal injuries, demyelination, and necrosis. Conclusions The mechanisms by which sepsis induces brain dysfunction are likely to include vascular and neuronal lesions, followed by the activation of glial cells and the presence of peripheral immune cells in the brain.

A relationship between neuroinflammation and the development of psychiatric disorder have been revealed by many studies in the past decade. Although studies have shown that stressors can induce long-term changes that may be related to behavioral responses, these alterations have been poorly studied soon after a stressor, such as maternal deprivation (MD). Thus, this study was designed to investigate the acute effect of experimental induction of MD on inflammatory and microglial activation markers in the brain of infant rats. Early MD was induced from postnatal day (PND) 1-10. On PND 10 the prefrontal cortex (PFC) and hippocampus from MD and control groups were removed to investigate microglial activation and neuroinflammatory markers. In the PFC the expressions of cluster of differentiation molecule 11B (CD11B), toll-like receptor (TLR)-2, and TLR-4 were increased in rats subjected to MD. The arginase expression was elevated in the PFC and hippocampus of maternally deprived rats. The cytokines interleukin-5 (IL-5), -6, -7, -10, tumor necrosis factor (TNF-α), and interferon gamma (INF-γ) were increased in the PFC of MD rats group. In the PFC the macrophage inflammatory proteins (MIP)-1α levels were reduced in MD rats group. In the hippocampus only the levels of TNF-α and INF-γ were elevated in infant rats subjected to MD. In conclusion, our results support the hypothesis that neuroinflammation and microglial activation, mainly in the PFC, could be involved with changes in the brain resident cells following MD, and these alterations could be associated to the development of psychiatric conditions late in life.

Bipolar disorder (BD) is a chronic affective disorder with extreme mood swings that include mania or hypomania and depression. Though the exact mechanism of BD is unknown, neuroinflammation is one of the numerous investigated etiopathophysiological causes of BD. This article presents a systematic review of the data regarding brain inflammation evaluating microglia, astrocytes, cytokines, chemokines, adhesion molecules, and other inflammatory markers in postmortem BD brain samples. This systematic review was performed according to PRISMA recommendations, and relevant studies were identified by searching the PubMed/MEDLINE, PsycINFO, EMBASE, LILACS, IBECS, and Web of Science databases for peer-reviewed journal articles published by March 2019. Quality of included studies appraised using the QUADAS-2 tool. Among the 1814 articles included in the primary screening, 51 articles measured inflammatory markers in postmortem BD brain samples. A number of studies have shown evidence of inflammation in BD postmortem brain samples. However, an absolute statement cannot be concluded whether neuroinflammation is present in BD due to the large number of studies did not evaluate the presence of infiltrating peripheral immune cells in the central nervous system (CNS) parenchyma, cytokines levels, and microglia activation in the same postmortem brain sample. For example, out of 15 studies that evaluated microglia cells markers, 8 studies found no effect of BD on these cells. Similarly, 17 out of 51 studies evaluating astrocytes markers, 9 studies did not find any effect of BD on astrocyte cells, whereas 8 studies found a decrease and 2 studies presented both increase and decrease in different brain regions. In addition, multiple factors account for the variability across the studies, including postmortem interval, brain area studied, age at diagnosis, undergoing treatment, and others. Future analyses should rectify these potential sources of heterogeneity and reach a consensus regarding the inflammatory markers in postmortem BD brain samples.

Bipolar disorder (BD) is a severe mental illness associated with significant illness burden. The exact etiology of BD remains elusive, but inflammation is suggested to be one of the numerous causes leading to BD. Accumulating evidence also supports an association between BD and inflammation. In this chapter, we first discuss the role of inflammatory conditions such as infections and autoimmune disorders in BD pathophysiology. We then discuss how the gut microbiome can be one of the perpetrators of the inflammatory response seen in BD patients. We highlighted the inflammatory mechanisms involving inflammatory cytokines, oxidative stress production, mitochondrial dysfunction, and microglial activation. Moreover, we explain how they contribute to the development of BD. We also included scientific evidence of immune markers evaluated in blood, cerebrospinal fluid, and postmortem brain samples, which demonstrates the involvement of inflammation and immune-regulated pathways in the neurobiology of BD. Understanding the biological basis of BD pathophysiology will open up new targets for novel therapies.

The gut microbiota is a complex ecosystem that comprises of more than 100 trillion symbiotic microbial cells. The microbiota, the gut, and the brain form an association, 'the microbiota-gut-brain axis,' and synchronize the gut with the central nervous system and modify the behavior and brain immune homeostasis. The bidirectional communication between gut and brain occurs via the immune system, the vagus nerve, the enteric nervous system, and microbial metabolites, including short-chain fatty acids (SCFAs), proteins, and tryptophan metabolites. Recent studies have implicated the gut microbiota in many neurodegenerative diseases, including Alzheimer's disease (AD). In this review, we present an overview of gut microbiota, including Firmicutes, Bacteroidetes, SCFA, tryptophan, bacterial composition, besides age-related changes in gut microbiota composition, the microbiota-gut-brain axis pathways, the role of gut metabolites in amyloid-beta clearance, and gut microbiota modulation from experimental and clinical AD models. Understanding the role of the microbiota may provide new targets for treatment to delay the onset, progression, or reverse AD, and may help in reducing the prevalence of AD.

Sepsis-associated encephalopathy is a serious consequence of sepsis, triggered by the host response against an infectious agent, that can lead to brain damage and cognitive impairment. Several mechanisms have been proposed in this bidirectional communication between the immune system and the brain after sepsis as neuroinflammation, oxidative stress, and mitochondrial dysfunction. Stanniocalcin-1 (STC-1), an endogen neuroprotective protein, acts as an anti-inflammatory and suppresses superoxide generation through induction of uncoupling proteins (UCPs) in the mitochondria. Here, we demonstrated a protective role of STC-1 on inflammatory responses in vitro, in activated microglia stimulated with LPS, and on neuroinflammation, oxidative stress, and mitochondrial function in the hippocampus of rats subjected to an animal model of sepsis by cecal ligation and puncture (CLP), as well the consequences on long-term memory. Recombinant human STC-1 (rhSTC1) suppressed the pro-inflammatory cytokine production in LPS-stimulated microglia without changing the UCP-2 expression. Besides, rhSTC1 injected into the cisterna magna decreased acute hippocampal inflammation and oxidative stress and increased the activity of complex I and II activity of mitochondrial respiratory chain and creatine kinase at 24 h after sepsis. rhSTC1 was effective in preventing long-term cognitive impairment after CLP. In conclusion, rhSTC1 confers significant neuroprotection by inhibiting the inflammatory response in microglia and protecting against sepsis-associated encephalopathy in rats.

Sepsis survivors present acute and long-term cognitive impairment and the pathophysiology of neurological dysfunction in sepsis involves microglial activation. Recently, the involvement of cytosolic receptors capable of forming protein complexes called inflammasomes have been demonstrated to perpetuate neuroinflammation. Thus, we investigated the involvement of the NLRP3 inflammasome activation on early and late brain changes in experimental sepsis. Two-month-old male Wistar rats were submitted to the sepsis model by cecal ligation and perforation (CLP group) or laparotomy only (sham group). Immediately after surgery, the animals received saline or NLRP3 inflammasome formation inhibitor (MCC950, 140 ng/kg) intracerebroventricularly. Prefrontal cortex and hippocampus were isolated for cytokine analysis, microglial and astrocyte activation, oxidative stress measurements, nitric oxide formation, and mitochondrial respiratory chain activity at 24 h after CLP. A subset of animals was followed for 10 days for survival assessment, and then behavioral tests were performed. The administration of MCC950 restored the elevation of IL-1β, TNF-α, IL-6, and IL-10 cytokine levels in the hippocampus. NLRP3 receptor levels increased in the prefrontal cortex and hippocampus at 24 h after sepsis, associated with microglial, but not astrocyte, activation. MCC950 reduced oxidative damage to lipids and proteins as well as preserved the activity of the enzyme SOD in the hippocampus. Mitochondrial respiratory chain activity presented variations in both structures studied. MCC950 reduced microglial activation, decreased acute neurochemical and behavioral alteration, and increased survival after experimental sepsis.

Sepsis causes organ dysfunction due to an infection, and it may impact the central nervous system. Neuroinflammation and oxidative stress are related to brain dysfunction after sepsis. Both processes affect microglia activation, neurotrophin production, and long-term cognition. Fish oil (FO) is an anti-inflammatory compound, and lipoic acid (LA) is a universal antioxidant substance. They exert neuroprotective roles when administered alone. We aimed at determining the effect of FO+LA combination on microglia activation and brain dysfunction after sepsis. Microglia cells from neonatal pups were co-treated with lipopolysaccharide (LPS) and FO or LA, alone or combined, for 24 h. Cytokine levels were measured. Wistar rats were subjected to sepsis by cecal ligation and perforation (CLP) and treated orally with FO, LA, or FO+LA. At 24 h after surgery, the hippocampus, prefrontal cortex, and total cortex were obtained and assayed for levels of cytokines, myeloperoxidase (MPO) activity, protein carbonyls, superoxide dismutase (SOD), and catalase (CAT) activity. At 10 days after surgery, brain-derived neurotrophic factor (BDNF) levels were determined and behavioral tests were performed. The combination diminished in vitro levels of pro-inflammatory cytokines. The combination reduced TNF-α in the cortex, IL-1β in the prefrontal cortex, as well as MPO activity, and decreased protein carbonyls formation in all structures. The combination enhanced catalase activity in the prefrontal cortex and hippocampus, elevated BDNF levels in all structures, and prevented behavioral impairment. In summary, the combination was effective in preventing cognitive damage by reducing neuroinflammation and oxidative stress and increasing BDNF levels.

Aging is a predominant risk factor for the development and progression of cardiovascular complications. Physiologically and anatomically, the heart undergoes numerous changes that result in poor cardiac function in the elderly population. Recently, several studies have provided promising results, confirming the ability of the senescence-accelerated mouse-prone 8 (SAMP8) model to accurately model age-related cardiovascular alterations. In this study, using a murine model of senescence, SAMP8, we aimed to investigate the effect of 3,4-dihydroxybenzalacetone (DBL), a catechol-containing phenylpropanoid derivative isolated from Inonotus obliquus (Chaga), on cardiac aging. DBL was administered at the doses of 10 mg/kg and 20 mg/kg by oral gavage to SAMP8 mice to examine aging-mediated cardiac changes, such as oxidative DNA damage, oxygen radical antioxidant capacity (ORAC) value, fibrosis, inflammation, and apoptosis. The treatment with DBL at both doses significantly reduced aging-mediated oxidative DNA damage, and simultaneously increased the ORAC value in the SAMP8 assay. Cardiac fibrosis was assessed with Azan-Mallory staining, and the number of cardiac remodeling markers was found to be significantly reduced after the treatment with DBL. We also observed a decrease in cardiomyocyte apoptosis as measured by the terminal transferase-mediated dUTP nick end labeling (TUNEL) staining method and the caspase-3 levels in SAMP8 mice compared with senescence-resistant control (SAMR1) mice. The findings from this study suggest that DBL has a potentially beneficial effect on aging-mediated myocardial alterations. Further studies are warranted to confirm the promising potential of this catechol compound against aging-associated myocardial dysfunction.

Schizophrenia is a complex psychiatric disorder that exhibits an interconnection between the immune system and the brain. Experimental and clinical studies have suggested the presence of neuroinflammation in schizophrenia. In the present study, the effect of antipsychotic drugs, including clozapine, risperidone, and haloperidol (10, 20 and 20 &mu, M, respectively), on the production of IL-1&alpha, IL-1&beta, IL-2, IL-4, IL-5, IL-6, IL-10, IL-17, IL-18, INF-&gamma, and TNF-&alpha, was investigated in the unstimulated and polyriboinosinic-polyribocytidilic acid [poly (I:C)]-stimulated primary microglial cell cultures. In the unstimulated cultures, clozapine, risperidone, and haloperidol did not influence the cytokine levels. Nevertheless, in cell cultures under strong inflammatory activation by poly (I:C), clozapine reduced the levels of IL-1&alpha, IL-2, and IL-17. Risperidone and haloperidol both reduced the levels of IL-1&alpha, IL-2, and IL-17, and increased the levels of IL-6, IL-10, INF-&gamma, Based on the results that were obtained with the antipsychotic drugs and observing that clozapine presented with a more significant anti-inflammatory effect, clozapine was selected for the subsequent experiments. We compared the profile of cytokine suppression obtained with the use of NLRP3 inflammasome inhibitor, CRID3 to that obtained with clozapine, to test our hypothesis that clozapine inhibits the NLRP3 inflammasome. Clozapine and CRID3 both reduced the IL-1&alpha, IL-2, and IL-17 levels. Clozapine reduced the level of poly (I:C)-activated NLRP3 expression by 57%, which was higher than the reduction thay was seen with CRID3 treatment (45%). These results suggest that clozapine might exhibit anti-inflammatory effects by inhibiting NLRP3 inflammasome and this activity is not typical with the use of other antipsychotic drugs under the conditions of strong microglial activation.

BackgroundBacterial meningitis is a devastating central nervous system (CNS) infection with acute and long-term neurological consequences, including cognitive impairment. The aim of this study was to understand the association between activated microglia-induced neuroinflammation and post-meningitis cognitive impairment.MethodMeningitis was induced in male Wistar rats by injectingStreptococcus pneumoniaeinto the brain through the cisterna magna, and rats were then treated with ceftriaxone. Twenty-four hours and 10 days after meningitis induction, rats were imaged with positron emission tomography (PET) using [11C]PBR28, a specific translocator protein (TSPO) radiotracer, to determine in vivo microglial activation. Following imaging, the expression of TSPO, cardiolipin, and cytochromec, inflammatory mediators, oxidative stress markers, and glial activation markers were evaluated in the prefrontal cortex and hippocampus. Ten days after meningitis induction, animals were subjected to behavioral tests, such as the open-field, step-down inhibitory avoidance, and novel object recognition tests.ResultsBoth 24-h (acute) and 10-day (long-term) groups of rats demonstrated increased [11C]PBR28 uptake and microglial activation in the whole brain compared to levels in the control group. Although free from infection, 10-day group rats exhibited increased expression levels of cytokines and markers of oxidative stress, microglial activation (IBA-1), and astrocyte activation (GFAP) similar to those seen in the 24-h group. Acute meningitis induction also elevated TSPO, cytochromec, and caspase-3 levels with no change in caspase-9 levels. Furthermore, upregulated levels of TSPO, cytochromec, and caspase-3 and caspase-9 were observed in the rat hippocampus 10 days after meningitis induction with a simultaneous reduction in cardiolipin levels. Animals showed a cognitive decline in all tasks compared with the control group, and this impairment may be at least partially mediated by activating a glia-mediated immune response and upregulating TSPO.ConclusionsTSPO-PET could potentially be used as an imaging biomarker for microglial activation and long-term cognitive impairment post-meningitis. Additionally, this study opens a new avenue for the potential use of TSPO ligands after infection-induced neurological sequelae.

Maternal immune activation (MIA) has been implicated as a risk factor for schizophrenia by several epidemiological studies. Animal models have confirmed this association between MIA and long-term neuropathology as well as behavioral abnormalities in the progeny. This chapter describes outcomes from the preclinical MIA models as well as results from recent clinical studies corroborating the effects of MIA on the neurodevelopment of the offspring. We have described various neurochemical, structural, and behavioral changes occurring in the developing brain of the MIA model offspring. Clinical studies delineating the effects of various maternal infections on fetal brain development and association of genetics with the development of schizophrenia have been summarized. We have also reviewed various neurobiological alterations induced by MIA in the fetal brain that play a role in the manifestation of schizophrenia. More research in this field and effective management of maternal infections are needed to reduce the future risk of schizophrenia in the offspring.

Neonatal meningitis (NM) is a serious infectious disease that accounts for elevated mortality and morbidity rates in low- and middle-income countries. Despite decreased mortality rates due to the advancement in antimicrobial therapy, the incidence of morbidity has not reduced; rather a decrease in mortality increases the number of survivors after NM. Nearly half of all meningitis survivors suffer from complex neurological or neuropsychiatric sequelae later in life. Neurologists and microbiologists are continuously searching to improve the quality of life after this dreadful infection. The experimental NM demonstrated positive effects of various pharmacological approaches using antioxidants, matrix metalloproteinase (MMPs) inhibitors, kynurenine metabolites inhibitors, and antidepressants in addition to antibiotics and supportive therapy. To understand the long-term complications after NM, it is necessary to have profound knowledge of the mechanisms behind its pathology. Hence, in this chapter, we aim to enumerate experimental neonatal and infant meningitis models and enlist possible mechanisms associated with behavioral alterations. We also demonstrate the links between NM, inflammatory mediators, and brain injuries in clinical studies. This chapter will also highlight currently available effective therapy to reduce neurological complications and discuss the possible treatment regimen in the future.

Bipolar disorder (BD) is a severe, debilitating psychiatric condition with onset in adolescence or young adulthood and often follows a relapsing and remitting course throughout life. The concept of neuroprogression in BD refers to the progressive path with an identifiable trajectory that takes place with recurrent mood episodes, which eventually leads to cognitive, functional, and clinical deterioration in the course of BD. Understanding the biological basis of neuroprogression helps to explain the subset of BD patients who experience worsening of their disorder over time. Additionally, the study of the neurobiological mechanisms underpinning neuroprogression will help BD staging based on systems biology. Replicated epidemiological studies have suggested inflammatory mechanisms as primary contributors to the neuroprogression of mood disorders. It is known that dysregulated inflammatory/immune pathways are often associated with BD pathophysiology. Hence, in this chapter, we focus on the evidence for the involvement of inflammation and immune regulated pathways in the neurobiological consequences of BD neuroprogression. Herein we put forth the evidence of immune markers from autoimmune disorders, chronic infections, and gut-brain axis that lead to BD neuroprogression. Further, we highlighted the peripheral and central inflammatory components measured along with BD progression.

Sepsis is systemic inflammatory response syndrome with a life-threatening organ dysfunction that is caused by an unbalanced host immune response in an attempt to eliminate invasive microorganisms. We posed questions, "Does sepsis survivor patients have increased risk of neuropsychiatric manifestations?" and "What is the mechanism by which sepsis induces long-term neurological sequelae, particularly substantial cognitive function decline in survivor patients and in pre-clinical sepsis models?" The studies were identified by searching PubMed/MEDLINE (National Library of Medicine), PsycINFO, EMBASE (Ovid), LILACS (Latin American and Caribbean Health Sciences Literature), IBECS (Bibliographical Index in Spanish in Health Sciences), and Web of Science databases for peer-reviewed journals that were published until January 2018. A total of 3555 papers were included in the primary screening. After that, 130 articles were selected for the study. A number of pre-clinical studies have shown an auto amplification of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6 in the first few hours after sepsis induction, also increased blood-brain barrier permeability, elevated levels of matrix metalloproteinases, increased levels of damage-associated molecular patterns were demonstrated. In addition, the rodents presented long-term cognitive impairment in different behavioral tasks that were prevented by blocking the mechanism of action of these inflammatory mediators. Clinical studies have showed that sepsis survivors presented increased bodily symptoms such as fatigue, pain, visual disturbances, gastrointestinal problems, and neuropsychiatric problems compared to before sepsis. Sepsis leaves the survivors with an aftermath of physiological, neuropsychiatric, and functional impairment. Systematic review registration: CRD42017071755.

Translocator protein (TSPO) is an 18kDa translocator membrane protein expressed in the outer mitochondrial membrane of steroid-synthesizing cells in the central and peripheral nervous systems. TSPO is involved in cellular functions, including the regulation of cell proliferation, transport of cholesterol to the inner mitochondrial membranes of glial cells, regulation of mitochondrial quality control, and haem synthesis. In the brain, TSPO has been extensively used as a biomarker of injury and inflammation. Indeed, TSPO was up-regulated in several inflammatory and neurodegenerative diseases. In contrast, the expression of TSPO was decreased in peripheral blood from psychiatric patients. Since TSPO is involved in several mechanisms related to mitochondrial function and inflammatory alterations, therapeutic approaches focusing on the regulation of TSPO may provide a new avenue for the treatment of neuropsychiatric disorders. Based on the involvement of mitochondrial alterations in the neurobiology of neuropsychiatric disorders, this review will focus on the functions and physiological roles of TSPO and the potential of TSPO ligands as therapeutic strategies for the treatment of neuropsychiatric disorders.

Despite advances in antimicrobial therapy and advanced critical care neonatal bacterial meningitis has a mortality rate of over 10% and induces neurological sequelae in 20-50% of cases. Escherichia coli K1 (E. coli K1) is the most common gram-negative organism causing neonatal meningitis and is the second most common cause behind group B streptococcus. We previously reported that an E. coli K1 experimental meningitis infection in neonatal rats resulted in habituation and aversive memory impairment and a significant increase in cytokine levels in adulthood. In this present study, we investigated the oxidative stress profile including malondialdehyde (MDA) levels, carbonyl protein formation, myeloperoxidase activity (MPO) activity, superoxide dismutase (SOD) activity and catalase (CAT) activity 6, 12, 24, 48, 72 and 96h after E. coli K1 experimental meningitis infection. In addition, sulfhydryl groups, nitrite and nitrate levels and activity of the mitochondrial respiratory chain enzymes were also measured in the frontal cortex and hippocampus of neonatal rats. The results from this study demonstrated a significant increase in MDA, protein carbonyls and MPO activity and a simultaneous decrease in SOD activity in the hippocampus of the neonatal meningitis survivors but the same was not observed in frontal cortex. In addition, we also observed a significant increase in complex IV activity in the hippocampus and frontal cortex of meningitis survivor rats. Thus, the results from this study reaffirmed the possible role of oxidative stress, nitric oxide and its related compounds in the complex pathophysiology of E. coli K1-induced bacterial meningitis.

Cardiac fibrosis is the major hallmark of adverse cardiac remodeling in chronic heart failure (CHF) and its therapeutic targeting might help against cardiac dysfunction during chronic conditions. Diuretic agents are potentially useful in these cases, but their effects on the cardiac fibrosis pathogenesis are yet to be identified. This study was designed to identify and compare the effects of diuretic drugs torasemide and furosemide on cardiac fibrosis in a rat model of dilated cardiomyopathy induced by porcine cardiac myosin mediated experimental autoimmune myocarditis. Gap junction proteins, connexin-43 and N-cadherin, expressions were downregulated in the hearts of CHF rats, while torasemide treatment has upregulated their expression. Western blotting and immunohistochemical analysis for various cardiac fibrosis related proteins as well as histopathological studies have shown that both drugs have potential anti-fibrotic effects. Among them, torasemide has superior efficacy in offering protection against adverse cardiac remodeling in the selected rat model of dilated cardiomyopathy. In conclusion, torasemide treatment has potential anti-fibrotic effect in the hearts of CHF rats, possibly via improving the gap junction proteins expression and thereby improving the cell-cell interaction in the heart. © 2016 BioFactors, 43(2):187-194, 2017.

The molecular mechanism of curcumin in macrophage polarization remains unknown in renal failure. We examined, whether curcumin treatment is associated with the modulation of renal function and macrophage phenotype switch in daunorubicin (DNR) induced nephrotoxicity model. Sprague-Dawley rats were treated with a cumulative dose of 9mg/kg DNR (i.v). Followed by curcumin (100mg/kg) administration orally every day for 6weeks. DNR treated rats showed nephrotoxicity as evidenced by worsening renal function, which was assessed by measuring creatinine and blood urea nitrogen in serum. These changes were reversed by treatment with curcumin, which resulted in significant improvement in renal function. Furthermore, curcumin increased cluster of differentiation (CD)163 expression, and down-regulated renal expression of antigen II type I receptor (AT1R), endothelin (ET)1, ET receptor type A and B (ETAR and ETBR), CD68 and CD80. Renal protein expression of extracellular signal-regulated kinase (ERK)1/2 and nuclear factor (NF)κB p65 were increased in DNR treated rats, and treatment with curcumin attenuated these increased expression. Curcumin mediated a further increase in the levels of interleukin (IL)-10. In addition, the expression of M1 phenotype was increased in DNR treated rats, which were attenuated by curcumin. Taken together, our results demonstrated that polyphenol curcumin has an ability to improve renal function and might induce the phenotypic switching from M1 to M2 macrophage polarization in DNR induced nephrotoxicity in rats.

Heart failure is typically related to aging as there is a definite relationship between age-related changes in the heart and the pathogenesis of heart failure. We have previously reported the involvement of p38 mitogen-activated protein kinase protein in cardiac function using animal models of heart failure. To further understand its relationship with aging-induced heart failure, we have compared its expression in the hearts of senescence accelerated-prone (SAMP8) mice and their control (SAMR1) with normal aging behavior. We have identified its activation along with reduced expression of 14-3-3η protein in SAMP8 mice hearts than in SAMR1 mice. To reveal the downstream signaling, we have measured the endoplasmic reticulum stress marker proteins along with some inflammatory and apoptosis markers and identified a significant increase in SAMP8 mice hearts than that of SAMR1. In addition, we have performed comet assay and revealed a significant DNA damage in the cardiomyocytes of SAMP8 mice when compared with SAMR1 mice. All these results demonstrate the role of 14-3-3η protein and the downstream mitogen-activated protein kinase-mediated endoplasmic reticulum stress, and apoptosis and DNA damage in aging-induced cardiac malfunction in SAMP8 mice. Thus targeting this signaling might be effective in treating age-related cardiac dysfunction. © 2016 BioFactors, 42(4):368-375, 2016.

Background/objectives 14-3-3η protein, a dimeric phosphoserine-binding protein, provides protection against adverse cardiac remodeling during pressure-overload induced heart failure in mice. To identify its role in myocardial infarction (MI), we have used mice with cardio-specific expression of dominant-negative 14-3-3η protein mutant (DN14-3-3) and performed the surgical ligation of left anterior descending coronary artery. Methods We have performed echocardiography to assess cardiac function, protein expression analysis using Western blotting, mRNA expression by real time-reverse transcription polymerase chain reaction and histopathological analyses. Results DN14-3-3 mice with MI displayed reduced survival, left ventricular ejection fraction and fractional shortening. Interestingly, DN14-3-3 mice subjected to MI showed increased cardiac hypertrophy, inflammation, fibrosis and apoptosis as compared to their wild-type counterparts. Mechanistically, DN14-3-3 mice with MI exhibited activation of endoplasmic reticulum (ER) stress and markers of maladaptive cardiac remodeling. Cardiac regeneration marker expression also decreased drastically in the DN14-3-3 mice with MI. Conclusion Depletion of the 14-3-3η protein causes cardiac dysfunction and reduces survival in mice with MI, probably via exacerbation of ER stress and death signaling pathways and suppression of cardiac regeneration. Thus, identification of drugs that can modulate cardiac 14-3-3η protein levels may probably provide a novel protective therapy for heart failure.

Jumihaidokuto, a Japanese kampo medicine, is prescribed in Japan for its anti-inflammatory activity. Here we have examined its beneficial effects against acute colitis induced by dextran sulfate sodium (DSS) in mice. We have used C57BL/6 female mice, divided into two groups and received 3% DSS in drinking water during the experimental period (8days). Treatment group mice received 1g/kg/day dose of Jumihaidokuto orally whereas DSS control group received equal volume of distilled water. Normal control group mice received plain drinking water. Jumihaidokuto treatment attenuated the colitis symptoms along with suppression of various inflammatory marker proteins such as IL-1β, IL-2Rα, IL-4, CTGF and RAGE. It has also down-regulated the oxidative stress and apoptotic signaling in the colons of mice with colitis. The present study has confirmed the beneficial effects of Jumihaidokuto on DSS induced acute colitis in mice and suggests that it can be a potential agent for the treatment of colitis.

Toki-shakuyaku-san (TOKI) is a Japanese kampo medicine, which consists of a mixture of herbal medicines and considered to be a promising remedial agent due to its immunomodulatory and anti-inflammatory effects. We examined the beneficial effects of TOKI in inflammatory bowel disease associated with the inflammation of the intestinal barrier. A study was designed, using C57BL/6 female mice and were administered with 3% DSS in drinking water for 8days with or without 1g/kg/day TOKI orally for the last 3days and a normal group supplied with plain drinking water for 8days. TOKI treatment attenuated the clinical symptoms of acute murine colitis and also alleviated the inflammatory mechanism by reducing the inflammatory mediators, such as IL-1β, IL-2, TGF-β, RAGE and TLR2. It has also decreased the levels of CHOP, caspase12, cleaved caspase3 and cleaved caspase7 and thereby down-regulated the endoplasmic reticulum stress and apoptotic signaling induced by DSS. Moreover, the expression levels of cyclin D1 and c-kit have also confirmed the beneficial role of TOKI in colitis. All these data suggested that TOKI can be a promising agent for the treatment of colitis since it alleviates the disease progression and severity.

Bipolar disorder (BD) is a chronic affective disorder with extreme mood swings that include mania or hypomania and depression. Though the exact mechanism of BD is unknown, neuroinflammation is one of the numerous investigated etiopathophysiological causes of BD. This article presents a systematic review of the data regarding brain inflammation evaluating microglia, astrocytes, cytokines, chemokines, adhesion molecules, and other inflammatory markers in postmortem BD brain samples. This systematic review was performed according to PRISMA recommendations, and relevant studies were identified by searching the PubMed/MEDLINE, PsycINFO, EMBASE, LILACS, IBECS, and Web of Science databases for peer-reviewed journal articles published by March 2019. Quality of included studies appraised using the QUADAS-2 tool. Among the 1814 articles included in the primary screening, 51 articles measured inflammatory markers in postmortem BD brain samples. A number of studies have shown evidence of inflammation in BD postmortem brain samples. However, an absolute statement cannot be concluded whether neuroinflammation is present in BD due to the large number of studies did not evaluate the presence of infiltrating peripheral immune cells in the central nervous system (CNS) parenchyma, cytokines levels, and microglia activation in the same postmortem brain sample. For example, out of 15 studies that evaluated microglia cells markers, 8 studies found no effect of BD on these cells. Similarly, 17 out of 51 studies evaluating astrocytes markers, 9 studies did not find any effect of BD on astrocyte cells, whereas 8 studies found a decrease and 2 studies presented both increase and decrease in different brain regions. In addition, multiple factors account for the variability across the studies, including postmortem interval, brain area studied, age at diagnosis, undergoing treatment, and others. Future analyses should rectify these potential sources of heterogeneity and reach a consensus regarding the inflammatory markers in postmortem BD brain samples.

Deep brain stimulation (DBS) of the medial forebrain bundle (MFB) displays a promising antidepressant effects in patients with treatment-refractory depression; however, a clear consensus on underlying mechanisms is still enigmatic. Herein, we investigated the effects of MFB-DBS on anhedonic-like behavior using the Froot Loops® consumption in a chronic unpredictable mild stress (CUS) model of depression, biochemical estimation of peripheral and central inflammatory cytokines, stress hormone, and brain-derived neurotrophic factor (BDNF). Seven days of MFB-DBS significantly reversed the 42-day CUS-generated anhedonic-like phenotype (p

The purpose of this study was to determine whether blocking of G protein βγ (Gβγ) signaling halts heart failure (HF) progression by macrophage phenotype manipulation. Cardiac Gβγ signaling plays a crucial role in HF pathogenesis. Previous data suggested that inhibiting Gβγ signaling reprograms T helper cell 1 (Th1) and Th2 cytokines, suggesting that Gβγ might be a useful drug target for treating HF. We investigated the efficacy of a small molecule Gβγ inhibitor, gallein, in a clinically relevant, experimental autoimmune myocarditis (EAM) model of HF as well as in human macrophage phenotypes in vitro. In the myocardium of HF patients, we observed that G protein coupled receptor kinase (GRK)2 levels were down-regulated compared with healthy controls. In rat EAM, treatment with gallein effectively improved survival and cardiac function, suppressed cardiac remodeling, and further attenuated myocardial protein expression of GRK2 as well as high mobility group box (HMGB)1 and its cascade signaling proteins. Furthermore, gallein effectively inhibited M1 polarization and promoted M2 polarization in vivo in the EAM heart and in vitro in human monocyte-derived macrophages. Taken together, these data suggest that the small molecule Gβγ inhibitor, gallein, could be an important pharmacologic therapy for HF as it can switch the phenotypic reprogramming from M1 to M2 phenotype in a rat model of EAM heart and in human macrophages.

心臓・腎臓など糖尿病性臓器障害の進展は, AMP活性化プロテインキナーゼ(AMPK)と小胞体ストレスが関与する. AMPKと小胞体ストレスは, 糖尿病性臓器障害における新治療薬の標的となりうることが示唆される. 糖尿病性腎症モデルの腎臓では酸化ストレス・炎症・線維化・脂肪沈着が亢進している. クルクミンはこれらを改善し, 安価な糖尿病腎症の予防薬・治療薬となりうることが示唆される., Diabetic nephropathy (DN) is the leading cause of chronic kidney disease (CKD) in patients starting renal replacement therapy and affects ～ 40 % of type 1 and type 2 diabetic patients. Hyperglycemia plays a key role in the pathogenesis of long-term complications in diabetes mellitus. This process is influenced by individual susceptibility (i.e. genetic determinants) and by accelerating factors such as hypertension, inflammation and dyslipidemia, all of which are able to stimulate generation of reactive oxygen species (ROS). The increased of ROS production causes tissue damage through 4 major mechanisms: (1) increased flux of glucose and other sugars through the polyol pathway; (2) increased intracellular formation of advanced glycation end products (AGEs) and its receptor; receptor for AGEs (RAGE) and its activating ligands; (3) activation of protein kinase C (PKC) isoforms; and (4) overactivity of the hexosamine pathway. The PKC signaling pathway is the postulate that has received the most attention lately. PKC activation is involved in the regulation of vascular permeability and contractility, endothelial cell activation and vasoconstriction, extracellular matrix (ECM) synthesis and turnover, abnormal angiogenesis, excessive apoptosis, leucocyte adhesion, abnormal growth factor signaling and cytokine action, as well as abnormal cell growth and angiogenesis, all of which are involved in the pathophysiology of diabetic vascular complications. There is growing evidence that abnormal lipid metabolism and renal accumulation of lipids play a role in the pathogenesis of DN. Sterol regulatory elemen-binding proteins (SREBPs) are transcription factors that regulate fatty acid and cholesterol synthesis. SREBPs belong to basic helix-loop-helix-leucine zipper family and activate the entire program of fatty acid and cholesterol synthesis in liver. Currently, there are three SREBPs isoforms that have been identified and characterized, namely, SREBP-1a, SREBP-1c, and SREBP-2. Multiple lines of evidence suggest that SREBP-1 and SREBP-2 have different relative effects on target genes. SREBP-1 preferentially activates genes involved in fatty acid and triglyceride synthesis, including Acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), whereas SREBP-2 preferentially activates genes involved in cholesterol biosynthesis such as hydroxymethylglutaryl CoA synthase, hydroxymethylglutaryl CoA reductase, farnesyl diphosphate synthase, and squalene synthase. It has been demonstrated that there is an inverse correlation between 5' Adenosine monophosphate-activated protein kinase (AMPK) and SREBP-1c activity in hepatocytes and in livers of re-fed mice and ethanol-fed mice. In fact, AMPK is sufficient and necessary for the suppression of SREBP-1c proteolytic processing, nuclear translocation, and gene expression of target lipogenic enzymes in response to AMPK activators, such as polyphenols and metformin, in primary hepatocytes under conditions mimicking in vivo hyperglycemia and hyperinsulinemia. Curcumin is the major active constituent of turmeric, a yellow compound originally isolated from the plant Curcuma longa L. and has been used as a dietary spice and coloring agent in foods. It has a wide spectrum of biological and pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anti-obesity, and anticancer properties, prevents liver injury and kidney toxicity. We investigated the role of curcumin in experimental type 1 diabetic rats. Our results suggest that curcumin could ameliorate hyperglycemia, hyperlipidemia, inflammation and fibrosis in kidney tissues associated with DN which involved the dual blockade of both PKCα and PKCβ1 activities, reduced macrophage infiltration through the inhibition of NF-κB, and reduced renal triglyceride accumulation through the modulation of AMPK-SREBP pathway. Collectively, my present study provides data to support the role of curcumin in ameliorating DN in rats.

There is a definite cardioprotective role for 14-3-3η protein against pressure overload induced cardiac hypertrophy and streptozotocin induced cardiac dysfunction in type 1 diabetes mellitus (DM). But it is not conclusive whether it has any influence on mitochondrial mediated cardiomyocyte apoptosis in type 2 DM. In order to test this hypothesis, we have used C57BL6/J (WT) mice with cardiac specific dominant negative mutation of 14-3-3η protein (DN 14-3-3η). Both WT and DN 14-3-3η mice were fed with high fat diet (HFD) for 12weeks. Their body weight and blood glucose levels were measured weekly and compared with standard diet (SD) fed mice. By the end of 12weeks, echocardiography was performed. Frozen myocardial sections were prepared to stain the apoptotic cardiomyocytes using TUNEL staining. DN 14-3-3η mice fed with HFD showed cardiac dysfunction as identified by the decreased fractional shortening and ejection fraction and increased cardiomyocyte apoptosis in TUNEL staining. Western blotting analysis using mitochondrial fraction of the ventricular tissue homogenates showed a significant reduction in the level of cytochrome c suggesting its translocation into cytoplasm, which may be crucial in inducing cardiomyocyte apoptosis. In addition, DN 14-3-3η mice depicted significantly increased levels of NADPH oxidase subunits suggesting oxidative stress, a significant reduction in phospho apoptosis signal-regulating kinase-1 (p-Ask-1) and increase in Ask-1 and phospho c-Jun N-terminal kinase (p-JNK) levels suggesting activation of Ask-1/JNK signaling. These results suggest that 14-3-3η has a protective role against mitochondria mediated cardiomyocyte apoptosis with the involvement of Ask-1/JNK signaling during HFD induced type 2 DM.

The present study was designed to evaluate the preventive effect of antioxidative traditional oriental medicine formulae, Shengmai San (SMS) and LingGuiZhuGanTang (LGZGT), against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (i.p 30 mg·kg−1for 5 consecutive days) induced neurotoxicity. Inin vitroantioxidant assays measured with Trolox and butyl hydroxyl toluene as reference antioxidant revealed that SMS has higher scavenging potential against hydroxyl radical than superoxide anion radical, but LGZGT was the reverse. The neuroprotective effect of SMS and LGZGT against MPTP was evaluated in mice by behavioral, biochemical, and immunohistochemical studies. In the behavioral study, both SMS and LGZGT significantly reversed the locomotive impairment induced by MPTP. Simultaneously, both formulae significantly prevented the MPTP induced dopaminergic neuron loss assessed by tyrosine hydroxylase in the midbrain. Both SMS and LGZGT significantly attenuated the elevated lipid peroxidation and protein carbonyls levels by MPTP. The DNA damage induced by MPTP was also prevented by both formulae. Although a little difference in the protective functions was observed between the two formulae, such as in DNA damage and behavioral studies, the results indicate that both SMS and LGZGT with antioxidant property act as a good candidate applicable for the antioxidant based complementary therapies of neurodegenerative diseases.