Liver-brain inflammation axis

Gut microbiome-brain-cirrhosis axis

Cirrhosis is characterized by inflammation, degeneration, and fibrosis of liver tissue. Along with being the most common cause of liver failure and liver transplant, cirrhosis is a significant risk factor for several neuropsychiatric conditions. The most common of these is HE, which is characterized by cognitive and ataxic symptoms, resulting from the buildup of metabolic toxins with liver failure. However, cirrhosis patients also show a significantly increased risk for neurodegenerative diseases such as Alzheimer and Parkinson diseases, and for mood disorders such as anxiety and depression. In recent years, more attention has been played to communication between the ways the gut and liver communicate with each other and with the central nervous system, and the way these organs influence each other's function. This bidirectional communication has come to be known as the gut-liver-brain axis. The gut microbiome has emerged as a key mechanism affecting gut-liver, gut-brain, and brain-liver communication. Clinical studies and animal models have demonstrated the significant patterns of gut dysbiosis when cirrhosis is present, both with or without concomitant alcohol use disorder, and have provided compelling evidence that this dysbiosis also influences the cognitive and mood-related behaviors. In this review, we have summarized the pathophysiological and cognitive effects associated with cirrhosis, links to cirrhosis-associated disruption of the gut microbiome, and the current evidence from clinical and preclinical studies for the modulation of the gut microbiome as a treatment for cirrhosis and associated neuropsychiatric conditions.

Physiological network approach to prognosis in cirrhosis: A shifting paradigm

Decompensated liver disease is complicated by multi-organ failure and poor prognosis. The prognosis of patients with liver failure often dictates clinical management. Current prognostic models have focused on biomarkers considered as individual isolated units. Network physiology assesses the interactions among multiple physiological systems in health and disease irrespective of anatomical connectivity and defines the influence or dependence of one organ system on another. Indeed, recent applications of network mapping methods to patient data have shown improved prediction of response to therapy or prognosis in cirrhosis. Initially, different physical markers have been used to assess physiological coupling in cirrhosis including heart rate variability, heart rate turbulence, and skin temperature variability measures. Further, the parenclitic network analysis was recently applied showing that organ systems connectivity is impaired in patients with decompensated cirrhosis and can predict mortality in cirrhosis independent of current prognostic models while also providing valuable insights into the associated pathological pathways. Moreover, network mapping also predicts response to intravenous albumin in patients hospitalized with decompensated cirrhosis. Thus, this review highlights the importance of evaluating decompensated cirrhosis through the network physiologic prism. It emphasizes the limitations of current prognostic models and the values of network physiologic techniques in cirrhosis.

Ovariectomy and High Fat-Sugar-Salt Diet Induced Alzheimer's Disease/Vascular Dementia Features in Mice

While the vast majority of Alzheimer's disease (AD) is non-familial, the animal models of AD that are commonly used for studying disease pathogenesis and development of therapy are mostly of a familial form. We aimed to generate a model reminiscent of the etiologies related to the common late-onset Alzheimer's disease (LOAD) sporadic disease that will recapitulate AD/dementia features. Naïve female mice underwent ovariectomy (OVX) to accelerate aging/menopause and were fed a high fat-sugar-salt diet to expose them to factors associated with increased risk of development of dementia/AD. The OVX mice fed a high fat-sugar-salt diet responded by dysregulation of glucose/insulin, lipid, and liver function homeostasis and increased body weight with slightly increased blood pressure. These mice developed AD-brain pathology (amyloid and tangle pathologies), gliosis (increased burden of astrocytes and activated microglia), impaied blood vessel density and neoangiogenesis, with cognitive impairment. Thus, OVX mice fed on a high fat-sugar-salt diet imitate a non-familial sporadic/environmental form of AD/dementia with vascular damage. This model is reminiscent of the etiologies related to the LOAD sporadic disease that represents a high portion of AD patients, with an added value of presenting concomitantly AD and vascular pathology, which is a common condition in dementia. Our model can, thereby, provide a valuable tool for studying disease pathogenesis and for the development of therapeutic approaches.

The Role of Diet in Multiple Sclerosis Onset: A Prospective Study Using UK Biobank

Multiple sclerosis (MS) is a debilitating autoimmune condition primarily affecting young adults, and its rise is evident globally. Despite this, its precise etiology remains elusive. Both genetic and environmental factors contribute to MS susceptibility; however, the link between diet and MS lacks substantial evidence due to limited large-scale studies. We exploited the UK Biobank resources to explore the nexus between diet, lifestyle, and MS risk. The dietary and lifestyle habits of MS incident cases, derived from a general food frequency questionnaire (FFQ) completed by all participants at study enrollment, were compared to those of subjects who did not develop MS during the follow-up. Our findings suggest the protective role of moderate oily fish consumption and weekly alcohol intake. Furthermore, by analyzing food intake data obtained through 24 h recall, completed by a subset of participants, we found a protective, though non-significant, trend of an increased adherence to the Mediterranean diet (MD). These findings, derived from the analysis of the UK Biobank and representing an unprecedented approach for this inquiry, warrant further exploration and integration in future research.

Allopregnanolone and its antagonist modulate neuroinflammation and neurological impairment

Neuroinflammation accompanies several brain disorders, either as a secondary consequence or as a primary cause and may contribute importantly to disease pathogenesis. Neurosteroids which act as Positive Steroid Allosteric GABA-A receptor Modulators (Steroid-PAM) appear to modulate neuroinflammation and their levels in the brain may vary because of increased or decreased local production or import from the systemic circulation. The increased synthesis of steroid-PAMs is possibly due to increased expression of the mitochondrial cholesterol transporting protein (TSPO) in neuroinflammatory tissue, and reduced production may be due to changes in the enzymatic activity. Microglia and astrocytes play an important role in neuroinflammation, and their production of inflammatory mediators can be both activated and inhibited by steroid-PAMs and GABA. What is surprising is the finding that both allopregnanolone, a steroid-PAM, and golexanolone, a novel GABA-A receptor modulating steroid antagonist (GAMSA), can inhibit microglia and astrocyte activation and normalize their function. This review focuses on the role of steroid-PAMs in neuroinflammation and their importance in new therapeutic approaches to CNS and liver disease.

The protective effects of Ninjin'yoeito against liver steatosis/fibrosis in a non-alcoholic steatohepatitis model mouse

Non-alcoholic steatohepatitis (NASH) is a progressive fibrotic form of non-alcoholic fatty liver disease. Liver fibrosis leads to liver cancer and cirrhosis, and drug therapy for NASH remains lacking. Ninjin'yoeito (NYT) has shown antifibrotic effects in a model of liver fibrosis without steatosis but has not been studied for NASH. Therefore, we evaluated the efficacy of NYT in mice fed a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) as a NASH model. Compared with the normal diet group, mice fed CDAHFD showed decreased body weight and increased white adipose tissue, liver weight, and triglyceride content in the liver. Furthermore, a substantial increase in the hepatic concentration of hydroxyproline, expression of α-smooth muscle actin (α-SMA), and transforming growth factor-β was observed in CDAHFD-fed mice. Masson's trichrome and Picro-Sirius red staining revealed a remarkable increase in collagen fiber compared with the normal diet group. Compared with mice that received CDAHFD alone, those supplemented with NYT exhibited reduced hepatic triglyceride and hydroxyproline levels and α-SMA expression. Additionally, compared with the group fed CDAHFD alone, the stained liver tissues of NYT-treated mice exhibited a reduction in Masson's trichrome- and Picro-Sirius red-positive areas. Locomotor activity was significantly reduced in the CDAHFD-fed group compared with the normal diet group. In the NYT-treated group, the CDAHFD-induced decrease in locomotor activity was significantly suppressed. The findings indicate that NYT inhibited fatty and fibrotic changes in the livers of NASH mice and alleviated the decrease in locomotor activity. Therefore, NYT may serve as a novel therapeutic approach for NASH.

Does the liver facilitate aging-related cognitive impairment: Conversation between liver and brain during exercise?

Liver, an important regulator of metabolic homeostasis, is critical for healthy brain function. In particular, age-related neurodegenerative diseases seriously reduce the quality of life for the elderly. As population aging progresses rapidly, unraveling the mechanisms that effectively delay aging has become critical. Appropriate exercise is reported to improve aging-related cognitive impairment. Whereas current studies focused on exploring the effect of exercise on the aging brain itself, ignoring the persistent effects of peripheral organs on the brain through the blood circulation. The aim of this paper is to summarize the communication and aging processes of the liver and brain and to emphasize the metabolic mechanisms of the liver-brain axis about exercise ameliorating aging-related neurodegenerative diseases. A comprehensive understanding of the potential mechanisms about exercise ameliorating aging is critical for improving adaptation to age-related brain changes and formulating effective interventions against age-related cognitive decline.

Stress increases hepatic release of lipocalin 2 which contributes to anxiety-like behavior in mice

Chronic stress induces anxiety disorders via both neural pathways and circulating factors. Although many studies have elucidated the neural circuits involved in stress-coping behaviors, the origin and regulatory mechanism of peripheral cytokines in behavioural regulation under stress conditions are not fully understood. Here, we identified a serum cytokine, lipocalin 2 (LCN2), that was upregulated in participants with anxiety disorders. Using a mouse model of chronic restraint stress (CRS), circulating LCN2 was found to be related to stress-induced anxiety-like behaviour via modulation of neural activity in the medial prefrontal cortex (mPFC). These results suggest that stress increases hepatic LCN2 via a neural pathway, leading to disrupted cortical functions and behaviour.

Intravenous MSC-Treatment Improves Impaired Brain Functions in the R6/2 Mouse Model of Huntington's Disease via Recovered Hepatic Pathological Changes

Huntington's disease (HD), a congenital neurodegenerative disorder, extends its pathological damages beyond the nervous system. The systematic manifestation of HD has been extensively described in numerous studies, including dysfunction in peripheral organs and peripheral inflammation. Gut dysbiosis and the gut-liver-brain axis have garnered greater emphasis in neurodegenerative research, and increased plasma levels of pro-inflammatory cytokines have been identified in HD patients and various in vivo models, correlating with disease progression. In the present study, we investigated hepatic pathological markers in the liver of R6/2 mice which convey exon 1 of the human mutant huntingtin gene. Furthermore, we evaluated the impact of intravenously administered Mesenchymal Stromal Cells (MSCs) on the liver enzymes, changes in hepatic inflammatory markers, as well as brain pathology and behavioral deficits in R6/2 mice. Our results revealed altered enzyme expression and increased levels of inflammatory mediators in the liver of R6/2 mice, which were significantly attenuated in the MSC-treated R6/2 mice. Remarkably, neuronal pathology and altered motor activities in the MSC-treated R6/2 mice were significantly ameliorated, despite the absence of MSCs in the postmortem brain. Our data highlight the importance of hepatic pathological changes in HD, providing a potential therapeutic approach. Moreover, the data open new perspectives for the search in blood biomarkers correlating with liver pathology in HD.

Neuroimmune interactions and their roles in neurodegenerative diseases

The nervous system possesses bidirectional, sophisticated and delicate communications with the immune system. These neuroimmune interactions play a vitally important role in the initiation and development of many disorders, especially neurodegenerative diseases. Although scientific advancements have made tremendous progress in this field during the last few years, neuroimmune communications are still far from being elucidated. By organizing recent research, in this review, we discuss the local and intersystem neuroimmune interactions and their roles in Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis. Unveiling these will help us gain a better understanding of the process of interplay inside the body and how the organism maintains homeostasis. It will also facilitate a view of the diseases from a holistic, pluralistic and interconnected perspective, thus providing a basis of developing novel and effective methods to diagnose, intervene and treat diseases.

The probiotic SLAB51 as agent to counteract BPA toxicity on zebrafish gut microbiota -liver-brain axis

A plethora of studies have so far described the toxic effects of bisphenol A (BPA) on organism health, highlighting the urgent need to find new strategies not only to reduce the presence of this toxicant but also to counteract its adverse effects. In this context, probiotics emerged as a potential tool since they promote organism welfare. Using a multidisciplinary approach, this study explores the effects of SLAB51 dietary administration to counteract BPA toxicity using zebrafish as a model. Adult males and females were maintained under standard conditions (control group; C), exposed for 28 days via the water to an environmental relevant dose of BPA (10 μg/L; BPA), dietary treated with SLAB51 (109 CFU/g of body weight; P) and co-treated with BPA plus SLAB51 (BPA + P). In the gut, exposure to BPA resulted in altered architecture in both males and females, with females also experiencing an increase of pathogenic bacterial species. Co-administration of BPA + P led to the restoration of normal gut architecture, favored beneficial bacteria colonization, and decreased the abundance of pathogenic species. In the liver, male BPA exposure led to steatosis and glycogen depletion, which was partially mitigated by SLAB51 co-administration. In contrast, in females exposed to BPA, the lack of steatosis along with the greater glycogen depletion, suggested an increase in energy demand as supported by the metabolomic phenotype. The analysis of liver metabolites in BPA + P males revealed increased levels of anserine and reduced levels of glutamine, which could lie behind the counteraction of the brain histopathological damage caused by BPA. In BPA + P females, a reduction of retinoic acid was found in the liver, suggesting an increase in retinoids responsible for BPA detoxification. Overall, these results demonstrate that SLAB51 exerts its beneficial effects on the gut microbiota-brain-liver axis through distinct molecular pathways, effectively mitigating the pleiotropic toxicity of BPA.

The liver and muscle secreted HFE2-protein maintains central nervous system blood vessel integrity

Liver failure causes breakdown of the Blood CNS Barrier (BCB) leading to damages of the Central-Nervous-System (CNS), however the mechanisms whereby the liver influences BCB-integrity remain elusive. One possibility is that the liver secretes an as-yet to be identified molecule(s) that circulate in the serum to directly promote BCB-integrity. To study BCB-integrity, we developed light-sheet imaging for three-dimensional analysis. We show that liver- or muscle-specific knockout of Hfe2/Rgmc induces BCB-breakdown, leading to accumulation of toxic-blood-derived fibrinogen in the brain, lower cortical neuron numbers, and behavioral deficits in mice. Soluble HFE2 competes with its homologue RGMa for binding to Neogenin, thereby blocking RGMa-induced downregulation of PDGF-B and Claudin-5 in endothelial cells, triggering BCB-disruption. HFE2 administration in female mice with experimental autoimmune encephalomyelitis, a model for multiple sclerosis, prevented paralysis and immune cell infiltration by inhibiting RGMa-mediated BCB alteration. This study has implications for the pathogenesis and potential treatment of diseases associated with BCB-dysfunction.

Modulating Stress Susceptibility and Resilience: Insights from miRNA Manipulation and Neural Mechanisms in Mice

This study explored the impact of microRNAs, specifically mmu-miR-1a-3p and mmu-miR-155-5p, on stress susceptibility and resilience in mice of different strains. Previous research had established that C57BL/6J mice were stress-susceptible, while NET-KO and SWR/J mice displayed stress resilience. These strains also exhibited variations in the serum levels of mmu-miR-1a-3p and mmu-miR-155-5p. To investigate this further, we administered antagonistic sequences (Antagomirs) targeting these microRNAs to C57/BL/6J mice and their analogs (Agomirs) to NET-KO and SWR/J mice via intracerebroventricular (i.c.v) injection. The impact of this treatment was assessed using the forced swim test. The results showed that the stress-susceptible C57/BL/6J mice could be transformed into a stress-resilient phenotype through infusion of Antagomirs. Conversely, stress-resilient mice displayed altered behavior when treated with Ago-mmu-miR-1a-3p. The study also examined the expression of mmu-miR-1a-3p in various brain regions, revealing that changes in its expression in the cerebellum (CER) were associated with the stress response. In vitro experiments with the Neuro2a cell line indicated that the Antago/Ago-miR-1a-3p and Antago/Ago-miR-155-5p treatments affected mRNAs encoding genes related to cAMP and Ca2+ signaling, diacylglycerol kinases, and phosphodiesterases. The expression changes of genes such as Dgkq, Bdnf, Ntrk2, and Pde4b in the mouse cerebellum suggested a link between cerebellar function, synaptic plasticity, and the differential stress responses observed in susceptible and resilient mice. In summary, this research highlights the role of mmu-miR-1a-3p and mmu-miR-155-5p in regulating stress susceptibility and resilience in mice and suggests a connection between these microRNAs, cerebellar function, and synaptic plasticity in the context of stress response.

Geriatric Surgery Produces a Hypoactive Molecular Phenotype in the Monocyte Immune Gene Transcriptome

Surgery is a major challenge for the immune system, but little is known about the immune response of geriatric patients to surgery. We therefore investigated the impact of surgery on the molecular signature of circulating CD14+ monocytes, cells implicated in clinical recovery from surgery, in older patients. We enrolled older patients having elective joint replacement (N = 19) or spine (N = 16) surgery and investigated pre- to postoperative expression changes in 784 immune-related genes in monocytes. Joint replacement altered the expression of 489 genes (adjusted p < 0.05), of which 38 had a |logFC| > 1. Spine surgery changed the expression of 209 genes (adjusted p < 0.05), of which 27 had a |logFC| > 1. In both, the majority of genes with a |logFC| > 1 change were downregulated. In the combined group (N = 35), 471 transcripts were differentially expressed (adjusted p < 0.05) after surgery; 29 had a |logFC| > 1 and 72% of these were downregulated. Notably, 21 transcripts were common across procedures. Thus, elective surgery in older patients produces myriad changes in the immune gene transcriptome of monocytes, with many suggesting development of an immunocompromised/hypoactive phenotype. Because monocytes are strongly implicated in the quality of surgical recovery, this signature provides insight into the cellular and molecular mechanisms of the immune response to surgery and warrants further study as a potential biomarker for predicting poor outcomes in older surgical patients.

Is fatigue related to the severity of liver inflammation in patients with chronic liver disease? A cross-sectional study

OBJECTIVES

Fatigue is common in patients with chronic liver disease; however, its pathogenesis is unclear. This study aimed to provide insights into the pathogenesis of chronic liver disease-related fatigue by assessing the relationship between fatigue and the degree of inflammation in chronic liver disease.

DESIGN

We performed a cross-sectional study of 1374 patients with pathologically proven chronic liver disease diagnosed at the Affiliated Hospital of Hangzhou Normal University in Hangzhou, China.

SETTING

Primary single-centre study.

PARTICIPANTS

One thousand three hundred and seventy-four patients with liver biopsy-proven chronic liver disease.

INTERVENTIONS

The patients were divided into fatigue and non-fatigue groups according to the Chronic Liver Disease Questionnaire. Propensity score matching was used to match the baseline features of the patients in the two groups.

PRIMARY AND SECONDARY OUTCOME MEASURES

Liver steatosis, ballooning, inflammation and fibrosis were measured according to the pathological results of liver biopsy. Fatigue was measured using the Chronic Liver Disease Questionnaire.

RESULTS

Of the 1374 patients, 262 (19.67%) experienced fatigue. There were 242 and 484 patients with and without fatigue, respectively, who were successfully matched for sex, age and classification of chronic liver disease by propensity score matching. After matching, the fatigue group showed higher liver enzyme levels, inflammation grades and fibrosis stages than the non-fatigue group (p<0.05). Multivariate analysis showed that age (OR: 2.026; p=0.003), autoimmune liver disease (OR: 2.749; p=0.002) and active inflammation (OR: 1.587; p=0.003) were independent risk factors for fatigue after adjusting for confounders. The OR of the risk for fatigue increased in a stepwise manner with increasing inflammation grade in young-aged and middle-aged patients (p<0.05). This tendency was not observed in elderly patients (p>0.05).

CONCLUSION

Patients with chronic liver disease were burdened by fatigue, which increased progressively with rising liver inflammation severity in young-aged and middle-aged rather than elderly patients.

Noncanonical regulation of imprinted gene Igf2 by amyloid-beta 1-42 in Alzheimer's disease

Reduced insulin-like growth factor 2 (IGF2) levels in Alzheimer's disease (AD) may be the mechanism relating age-related metabolic disorders to dementia. Since Igf2 is an imprinted gene, we examined age and sex differences in the relationship between amyloid-beta 1-42 (Aβ₄₂) accumulation and epigenetic regulation of the Igf2/H19 gene cluster in cerebrum, liver, and plasma of young and old male and female 5xFAD mice, in frontal cortex of male and female AD and non-AD patients, and in HEK293 cell cultures. We show IGF2 levels, Igf2 expression, histone acetylation, and H19 ICR methylation are lower in females than males. However, elevated Aβ₄₂ levels are associated with Aβ₄₂ binding to Igf2 DMR2, increased DNA and histone methylation, and a reduction in Igf2 expression and IGF2 levels in 5xFAD mice and AD patients, independent of H19 ICR methylation. Cell culture results confirmed the binding of Aβ₄₂ to Igf2 DMR2 increased DNA and histone methylation, and reduced Igf2 expression. These results indicate an age- and sex-related causal relationship among Aβ₄₂ levels, epigenomic state, and Igf2 expression in AD and provide a potential mechanism for Igf2 regulation in normal and pathological conditions, suggesting IGF2 levels may be a useful diagnostic biomarker for Aβ₄₂ targeted AD therapies.

A Mediterranean Diet and Walking Intervention to Reduce Cognitive Decline and Dementia Risk in Independently Living Older Australians: The MedWalk Randomized Controlled Trial Experimental Protocol, Including COVID-19 Related Modifications and Baseline Characteristics

BACKGROUND

Several clinical trials have examined diet and physical activity lifestyle changes as mitigation strategies for risk factors linked to cognitive decline and dementias such as Alzheimer's disease. However, the ability to modify these behaviors longer term, to impact cognitive health has remained elusive.

OBJECTIVE

The MedWalk trial's primary aim is to investigate whether longer-term adherence to a Mediterranean-style diet and regular walking, delivered through motivational interviewing and cognitive-behavioral therapy (MI-CBT), can reduce age-associated cognitive decline and other dementia risk factors in older, independently living individuals without cognitive impairment.

METHODS

MedWalk, a one-year cluster-randomized controlled trial across two Australian states, recruited 60-90-year-old people from independent living retirement villages and the wider community. Participants were assigned to either the MedWalk intervention or a control group (maintaining their usual diet and physical activity). The primary outcome is 12-month change in visual memory and learning assessed from errors on the Paired Associates Learning Task of the Cambridge Neuropsychological Test Automated Battery. Secondary outcomes include cognition, mood, cardiovascular function, biomarkers related to nutrient status and cognitive decline, MI-CBT effectiveness, Mediterranean diet adherence, physical activity, quality of life, cost-effectiveness, and health economic evaluation.Progress and Discussion:Although COVID-19 impacts over two years necessitated a reduced timeline and sample size, MedWalk retains sufficient power to address its aims and hypotheses. Baseline testing has been completed with 157 participants, who will be followed over 12 months. If successful, MedWalk will inform interventions that could substantially reduce dementia incidence and ameliorate cognitive decline in the community.

TRIAL REGISTRATION

Registered on the Australia New Zealand Clinical Trials Registry ANZCTR 12620000978965 (https://www.anzctr.org.au).

Behavioral effects and inflammatory markers in the brain and periphery after repeated social defeat stress burdened by Opisthorchis felineus infection in mice

The combination of 4-week repeated social defeat stress (RSDS) and Opisthorchis felineus infection was modeled in C57BL/6 mice. Various parameters were compared between three experimental groups of male mice (SS: mice subjected to RSDS, OF: mice infected with O. felineus, and OF + SS: mice subjected to both adverse factors) and behavior-tested and intact (INT) controls. The combination caused liver hypertrophy and increased the blood level of proinflammatory cytokine interleukin 6 and proteolytic activity of cathepsin B in the hippocampus. Meanwhile, hypertrophy of the spleen and of adrenal glands was noticeable. Anxious behavior in the elevated plus-maze test was predominantly due to the infection, with synergistic effects of an interaction of the two adverse factors on multiple parameters in OF + SS mice. Depression-like behavior in the forced swimming test was caused only by RSDS and was equally pronounced in SS mice and OF + SS mice. Helminths attenuated the activities of cathepsin B in the liver and hypothalamus (which were high in SS mice) and increased cathepsin L activity in the liver. The highest blood level of corticosterone was seen in SS mice but was decreased to control levels by the trematode infection. OF mice had the lowest level of corticosterone, comparable to that in INT mice. Thus, the first data were obtained on the ability of O. felineus helminths-even at the immature stage-to modulate the effects of RSDS, thereby affecting functional connections of the host, namely "helminths → liver↔brain axis."

Thymol ameliorated neurotoxicity and cognitive deterioration in a thioacetamide-induced hepatic encephalopathy rat model; involvement of the BDNF/CREB signaling pathway

In the present study, we aimed to delineate the neuroprotective potential of thymol (THY) against neurotoxicity and cognitive deterioration induced by thioacetamide (TAA) in an experimental model of hepatic encephalopathy (HE). Rats received TAA (100 mg kg^-1, intraperitoneally injected, three times per week) for two weeks. THY (30 and 60 mg kg^-1), and Vit E (100 mg k^-1) were administered daily by oral gavage for 30 days after HE induction. Supplementation with THY significantly improved liver function, reduced serum ammonia level, and ameliorated the locomotor and cognitive deficits. THY effectively modulated the alteration in oxidative stress markers, neurotransmitters, and brain ATP content. Histopathology of liver and brain tissues showed that THY had ameliorated TAA-induced damage, astrocyte swelling and brain edema. Furthermore, THY downregulated NF-kB and upregulated GFAP protein expression. In addition, THY significantly promoted CREB and BDNF expression at both mRNA and protein levels, together with enhancing brain cAMP level. In conclusion, THY exerted hepato- and neuroprotective effects against HE by mitigating hepatotoxicity, hyperammonemia and brain ATP depletion via its antioxidant, anti-inflammatory effects in addition to activation of the CREB/BDNF signaling pathway.

Non-alcoholic fatty liver disease, serum cytokines, and dementia among rural-dwelling older adults in China: a population-based study

BACKGROUND

Little is known about whether non-alcoholic fatty liver disease (NAFLD) is associated with dementia as well as the role of serum pro-inflammatory cytokines in the association. We aimed to investigate the interrelationships of NAFLD, serum cytokines, and dementias among rural-dwelling older adults.

METHODS

This population-based cross-sectional study included 5,129 participants (age ≥60 years; 61.79% women) who were living in rural communities and examined in March-September 2018. NAFLD was defined through transabdominal ultrasound examination in the absence of hepatitis B or excessive alcohol consumption. Serum cytokines were measured in a subsample (n=1,686). Dementia, Alzheimer's disease (AD), and vascular dementia (VaD) were diagnosed following international criteria. Data were analyzed with logistic regression and mediation models.

RESULTS

Of the 5,129 participants, 455 (8.87%) were detected with moderate-to-severe NAFLD and 292 (5.69%) were diagnosed with dementia (188 with AD and 96 with VaD). The multivariable-adjusted odds ratios (ORs) associated with moderate-to-severe (vs. no-to-mild) NAFLD were 2.22 (95% confidence interval, 1.41-3.49) for all-cause dementia, 1.88 (1.01-3.50) for AD, and 2.62 (1.33-5.17) for VaD. In the cytokine subsample, controlling for multiple potential confounders, moderate-to-severe NAFLD was significantly associated with higher levels of serum monocyte chemotactic protein-1 (MCP-1), interleukin-17A (IL-17A), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) (P<0.05). The mediation analysis showed that IL-6 mediated 12.56% of the association between NAFLD and VaD.

CONCLUSIONS

Moderate-to-severe NAFLD is associated with dementia and AD, especially with VaD, among rural-dwelling Chinese older adults, in which the association with VaD is partly mediated by serum inflammatory cytokines.

Protocatechuic acid protects against thioacetamide-induced chronic liver injury and encephalopathy in mice via modulating mTOR, p53 and the IL-6/ IL-17/ IL-23 immunoinflammatory pathway

Protocatechuic acid (PCA), a natural phenolic acid, is known for antioxidant, anti-inflammatory, anti-apoptotic, and anti-fibrotic activities. However, the protective mechanisms of PCA on thioacetamide (TAA)-induced liver/brain injury are not well addressed. Chronic liver injury was induced in mice by intraperitoneal injection of TAA (200 mg/kg, 3 times/week) for 8 weeks. Simultaneously, PCA (100, 150 mg/kg/day, p.o.) was given daily from the 4th week. Protocatechuic acid ameliorated liver and brain damage indicated by the decrease in serum activities of aminotransferases, gamma-glutamyl transferase, alkaline phosphatase, lactate dehydrogenase, levels of bilirubin, and ammonia concomitant with restoration of normal albumin levels. Additionally, PCA treatment ameliorated oxidative stress in liver and brain, confirmed by the decrease in malondialdehyde and nitric oxide levels and the increase in antioxidant activities. Moreover, PCA showed anti-inflammatory actions through downregulation of TNF-α expression in the liver and IL-6/IL-17/IL-23 levels in the brain, which is confirmed by the decrease in CD4⁺ T brain cell numbers. Most importantly, PCA treatment showed a significant decrease in mTOR level and number of LC3 positive cells in both liver and brain tissues. Consequently, PCA could inhibit mTOR-induced apoptosis, as it showed anti-apoptotic actions through downregulation of caspase-3 expression in liver and p53 expression in liver and brain. Furthermore, liver and brain tissues of treated mice showed restoration of normal histology. It can be concluded that, several mechanisms, including: antioxidant, anti-inflammatory, anti-autophagic and anti-apoptotic activities can be implicated in the hepato- and neuroprotective potentials of PCA.

Fatigue in Cirrhosis

Fatigue is a common symptom in patients with liver disease and has a significant impact on the health-related quality of life (HR-QoL). Its pathogenesis is poorly understood and is considered multifactorial. The liver is central in the pathogenesis of fatigue because it uniquely regulates much of the production, storage, and release of substrate for energy generation. Also, the liver "cross-talks" with the key organs that are responsible for this symptom complex-gut, skeletal muscle, and brain. Fatigue can have both peripheral (i.e., neuromuscular) and central (i.e., resulting from changes in neurotransmission within the brain) components. The treatment strategies for the management of fatigue are behavioral changes and pharmacotherapy, along with dietetic intervention and exercise. However, there is no consensus on management strategies for fatigue in patients with liver disease. This article gives an overview of fatigue as a concept, its pathophysiology, measures to evaluate fatigue in patients with liver disease, the impact of fatigue on chronic liver disease, assessment of fatigue in an appropriate clinical setting, and various interventions to manage fatigue.

Selenium reduces nociceptive response in acute 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced neurotoxicity

The potential of Se to alleviate pain associated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity was investigated.

Swiss mice were intraperitoneally injected with MPTP (20 mg/kg) 4 times with an interval of 2 h in 1 day. Seven days after MPTP injection, the mice (n = 5 mice per group) were randomly assigned to groups: MPTP-, DOPA (50 mg/kg)-, Se4 (0.4 mg/kg)-, Se6 (0.6 mg/kg)-, DOPA+Se4-, and DOPA+Se6-treated groups were compared with controls. MPTP mice were treated for seven days; thereafter, motor-coordination and nociceptive-motor reactions were assessed. Pro-inflammatory cytokines (IL-1β, IL-6 and TNFα), and selected pain biomarkers (substance P (SP), glutamate and β-endorphin) were assessed in the serum and the substantial nigra pars compacta (SNpc).

Motor activity was increased slightly by Se (0.6 or 0.4 mg/kg) vs. MPTP (10.48 ± 2.71 or 11.81 ± 1.28 s vs. 3.53 ± 0.06 s respectively) but considerably increased by DOPA (50 mg/kg) vs. MPTP (50.47 ± 3.06 s vs. 3.53 ± 0.06 s respectively). Se and DOPA increased nociceptive threshold but Se alone reduced both serum and SN pro-inflammatory cytokines. Se modulates SP while DOPA modulates SP and glutamate in the SNpc of mice treated with MPTP.

Se suppressed pro-inflammatory cytokines and restored the basal pain biomarkers in the SNpc of mice treated with MPTP. Se requires further study as analgesic adjuvant.

Granulocyte Colony-Stimulating Factor Treatment Before Radiotherapy Protects Against Radiation-Induced Liver Disease in Mice

Radiation-induced liver disease (RILD) remains a major problem resulting from radiotherapy. In this scenario, immunotherapy with granulocyte colony-stimulating factor (G-CSF) arises as an attractive approach that might improve the injured liver. Here, we investigated G-CSF administration’s impact before and after liver irradiation exposure using an association of alcohol consumption and local irradiation to induce liver disease model in C57BL/6 mice. Male and female mice were submitted to a previous alcohol-induced liver injury protocol with water containing 5% alcohol for 90 days. Then, the animals were treated with G-CSF (100 μg/kg/d) for 3 days before or after liver irradiation (18 Gy). At days 7, 30, and 60 post-radiation, non-invasive liver images were acquired by ultrasonography, magnetic resonance, and computed tomography. Biochemical and histological evaluations were performed to verify whether G-CSF could prevent liver tissue damage or reverse the acute liver injury. Our data showed that the treatment with G-CSF before irradiation effectively improved morphofunctional parameters caused by RILD, restoring histological arrangement, promoting liver regeneration, preserving normal organelles distribution, and glycogen granules. The amount of OV-6 and F4/80-positive cells increased, and α-SMA positive cells’ presence was normalized. Additionally, prior G-CSF administration preserved serum biochemical parameters and increased the survival rates (100%). On the other hand, after irradiation, the treatment showed a slight improvement in survival rates (79%) and did not ameliorate RILD. Overall, our data suggest that G-CSF administration before radiation might be an immunotherapeutic alternative to radiotherapy planning to avoid RILD.

Postmortem mitochondrial membrane permeability transition assessment of apoptotic cell death in brain and liver of insulin resistant, ovariectomised rats

The adverse alterations in mitochondrial functions can affect neuronal function negatively, as they play a crucial role in neuronal plasticity and death. Direct measurements of mitochondrial activity, including membrane potential and ATP production, are not easily achieved in post-mortem brain and liver samples because most organ functions cease to work after death; in fact, with increasing post-mortem intervals (PMI), the brain and liver tissues deteriorate rapidly. Standard procedures of mitochondria isolation, protein determination expressed as BSA equivalent, and spectrophotometric assessment of pore opening at 540 nm were employed. Our results showed that (a) intact mitochondria may be isolated from rat brain and liver of these rats after storage in animal body (in situ) at -20 °C for 7 days (168 h, post-mortem), (b) some population of these mitochondria can still take up exogenous Ca2+ and (c) they can still resist osmotically induced large amplitude swelling in a suitable buffer. The need for mitochondrial purity, structural integrity and abundance for functional studies are common hindrances that can encumber mitochondrial research. Therefore, this study is significant to have shown that PMI up to 7 days did not extensively, diminish MMPT pore status in normal and diabetic, ovariectomised rats. This can be relevant for forensic data mining.

Prenatal alcohol-induced sex differences in immune, metabolic and neurobehavioral outcomes in adult rats

Prenatal alcohol exposure (PAE) can result in neurobehavioral anomalies, that may be exacerbated by co-occurring metabolic and immune system deficits. To test the hypothesis that the peripheral inflammation in adult PAE offspring is linked to poor glucose metabolism and neurocognitive deficits, pregnant Sprague-Dawley rats were exposed to ethanol vapor or ambient air during the latter half of gestation. We assessed, in adult offspring of both sexes, performance on a battery of neurocognitive behaviors, glucose tolerance, circulating and splenic immune cells by flow-cytometry, and circulating and tissue (liver, mesenteric adipose, and spleen) cytokines by multiplexed assays. PAE reduced both the ratio of spleen to body weight and splenic regulatory T-cell (Treg) numbers. PAE males, but not females exhibited an increase in circulating monocytes. Overall, PAE males exhibited a suppression of cytokine levels, while PAE females exhibited elevated cytokines in mesenteric adipose tissue (IL-6 and IL1α) and liver (IFN-γ, IL-1β, IL-13, IL-18, IL-12p70, and MCP-1), along with increased glucose intolerance. Behavioral analysis also showed sex-dependent PAE effects. PAE-males exhibited increased anxiety-like behavior while PAE-females showed decreased social interaction. PAE offspring of both sexes exhibited impaired recognition of novel objects. Multilinear regression modeling to predict the association between peripheral immune status, glucose intolerance and behavioral outcomes, showed that in PAE offspring, higher levels of adipose leptin and liver TNF- α predicted higher circulating glucose levels. Lower liver IL-1 α and higher plasma fractalkine predicted more time spent in the center of an open-field with sex being an additional predictor. Higher circulating and splenic Tregs predicted better social interaction in the PAE-offspring. Collectively, our data show that peripheral immune status is a persistent, sex-dependent predictor of glucose intolerance and neurobehavioral function in adult PAE offspring.

Liver-specific decrease in Tff3 gene expression in infant mice perinatally exposed to 2,3,7,8-tetrabromodibenzofuran or 2,3,7,8-tetrachlorodibenzo-p-dioxin

Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/DFs) are byproducts of brominated flame retardants and can cause adverse health effects. Although exposure to polychlorinated (PC) DD/DFs induces toxic effects, including liver injury and neurobehavioral disorder, little is known about toxicities associated with PBDD/DF exposure. Thus, we examined effects of perinatal exposure to brominated congener on the infant mouse. Gene expression in several organs, such as the liver and brain, was analyzed in mouse offspring born to dams administered 2,3,7,8-tetrabromodibenzofuran (TBDF; 9 or 45 μg/kg body weight) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 3 μg/kg body weight) on gestational day 12.5. An increase in liver size was observed in TBDF- or TCDD-exposed offspring in infancy. Gene microarray analysis revealed that 163 and 36 genes were markedly upregulated and downregulated, respectively, in the liver of TBDF-exposed mice compared with those in vehicle-treated mice on postnatal day (PND) 5. Significant increases in Cyp1a1, Cyp1a2, Fmo3, and Pnliprp1 and decreases in Tff3, Ocstamp, Kcnk16, and Lgals2 mRNA levels in TBDF-exposed offspring on PNDs 5 and 12 were confirmed by quantitative PCR. In particular, a significant reduction in Tff3 mRNA in the liver, but not in the brain, small intestine, colon, and kidney, was observed in offspring perinatally exposed to TBDF or TCDD. Ultrasonic calls of TBDF- or TCDD-exposed offspring on PNDs 3-5 were impaired. Taken together, perinatal exposure to polyhalogenated dioxin/furan congeners disrupts gene expression patterns in the liver and ultrasonic calling during infancy. These results suggest that liver injury may contribute to neurobehavioral disorder.

Investigation of possible neuroprotective effects of some plant extracts on brain in bile duct ligated rats

This study aimed to investigate the possible neuroprotective effects of bitter melon (BM), chard, and parsley extracts on oxidative damage that may occur in the brain of rats with bile duct ligation (BDL)-induced biliary cirrhosis. It was observed that lipid peroxidation (LPO), sialic acid (SA), and nitric oxide (NO) levels increased; glutathione (GSH) levels, catalase (CAT) activity, and tissue factor (TF) activity decreased significantly in the BDL group. However, in groups with BDL given BM, chard, and parsley extracts LPO, SA, NO levels decreased; GSH levels and CAT activities increased significantly. No significant differences were observed between groups in total protein, glutathione-S-transferase, superoxide dismutase, and boron. Histological findings were supported by the biochemical results. BM, chard, and parsley extracts were effective in the regression of oxidant damage caused by cirrhosis in the brain tissues. PRACTICAL APPLICATIONS: Bitter melon (BM), chard, and parsley have antioxidant properties due to their bioactive compounds which are involved in scavenging free radicals, suppressing their production, and stimulating the production of endogenous antioxidant compounds. Since BM, chard, and parsley extracts were found to be effective in the regression of oxidant damage caused by cirrhosis in the brain tissues, these plant extracts may be an alternative in the development of different treatment approaches against brain damage in cirrhosis. At the same time, these species have been used as food by the people for many years. Therefore, they can be used safely as neuroprotective agents in treatment.

Similarities in alcohol and opioid withdrawal syndromes suggest common negative reinforcement mechanisms involving the interoceptive antireward pathway

Alcohol and opioids are two major contributors to so-called deaths of despair. Though the effects of these substances on mammalian systems are distinct, commonalities in their withdrawal syndromes suggest a shared pathophysiology. For example, both are characterized by marked autonomic dysregulation and are treated with alpha-2 agonists. Moreover, alcohol and opioids rapidly induce dependence motivated by withdrawal avoidance. Resemblances observed in withdrawal syndromes and abuse behavior may indicate common addiction mechanisms. We argue that neurovisceral feedback influences autonomic and emotional circuits generating antireward similarly for both substances. Amygdala is central to this hypothesis as it is principally responsible for negative emotion, prominent in addiction and motivated behavior, and processes autonomic inputs while generating autonomic outputs. The solitary nucleus (NTS) has strong bidirectional connections to the amygdala and receives interoceptive inputs communicating visceral states via vagal afferents. These visceral-emotional hubs are strongly influenced by the periphery including gut microbiota. We propose that gut dysbiosis contributes to alcohol and opioid withdrawal syndromes by contributing to peripheral and neuroinflammation that stimulates these antireward pathways and motivates substance dependence.

Understanding importance of clinical biomarkers for diagnosis of anxiety disorders using machine learning models

Anxiety disorders are a group of mental illnesses that cause constant and overwhelming feelings of anxiety and fear. Excessive anxiety can make an individual avoid work, school, family get-togethers, and other social situations that in turn might amplify these symptoms. According to the World Health Organization (WHO), one in thirteen persons globally suffers from anxiety. It is high time to understand the roles of various clinical biomarker measures that can diagnose the types of anxiety disorders. In this study, we apply machine learning (ML) techniques to understand the importance of a set of biomarkers with four types of anxiety disorders—Generalized Anxiety Disorder (GAD), Agoraphobia (AP), Social Anxiety Disorder (SAD) and Panic Disorder (PD). We used several machine learning models and extracted the variable importance contributing to a type of anxiety disorder. The study uses a sample of 11,081 Dutch citizens’ data collected by the Lifelines, Netherlands. The results show that there are significant and low correlations among GAD, AP, PD and SAD and we extracted the variable importance hierarchy of biomarkers with respect to each type of anxiety disorder which will be helpful in designing the experimental setup for clinical trials related to influence of biomarkers on type of anxiety disorder.

Associations of Serum Liver Function Markers With Brain Structure, Function, and Perfusion in Healthy Young Adults

Background: Previous neuroimaging studies have demonstrated brain abnormalities in patients with hepatic diseases. However, the identified liver-brain associations are largely limited to disease-affected populations, and the nature and extent of such relations in healthy subjects remain unclear. We hypothesized that serum liver function markers within a normal level would affect brain properties. Method: One hundred fifty-seven healthy young adults underwent structural, resting-state functional, and arterial spin labeling MRI scans. Gray matter volume (GMV), regional homogeneity (ReHo), and cerebral blood flow (CBF) analyses were performed to assess brain structure, function, and perfusion, respectively. Peripheral venous blood samples were collected to measure serum liver function markers. Correlation analyses were conducted to test potential associations between liver function markers and brain imaging parameters. Results: First, serum proteins showed relations to brain structure characterized by higher albumin associated with increased GMV in the parahippocampal gyrus and amygdala and lower globulin and a higher albumin/globulin ratio with increased GMV in the olfactory cortex and parahippocampal gyrus. Second, serum bilirubin was linked to brain function characterized by higher bilirubin associated with increased ReHo in the precuneus, middle cingulate gyrus, inferior parietal lobule, and supramarginal gyrus and decreased ReHo in the caudate nucleus. Third, serum alanine transaminase (ALT) was related to brain perfusion characterized by higher ALT associated with increased CBF in the superior frontal gyrus and decreased CBF in the middle occipital gyrus, angular gyrus, precuneus, and middle temporal gyrus. More importantly, we found that CBF in the superior frontal gyrus was a significant mediator of the association between serum ALT level and working memory performance. Conclusion: These findings may not only expand existing knowledge about the relationship between the liver and the brain but also have clinical implications for studying brain impairments secondary to liver diseases as well as providing potential neural targets for their diagnosis and treatment.

Implications of Breast Cancer Chemotherapy-Induced Inflammation on the Gut, Liver, and Central Nervous System

Breast Cancer is still one of the most common cancers today; however, with advancements in diagnostic and treatment methods, the mortality and survivorship of patients continues to decrease and increase, respectively. Commonly used treatments today consist of drug combinations, such as doxorubicin and cyclophosphamide; docetaxel, doxorubicin, and cyclophosphamide; or doxorubicin, cyclophosphamide, and paclitaxel. Although these combinations are effective at destroying cancer cells, there is still much to be understood about the effects that chemotherapy can have on normal organ systems such as the nervous system, gastrointestinal tract, and the liver. Patients can experience symptoms of cognitive impairments or “chemobrain”, such as difficulty in concentrating, memory recollection, and processing speed. They may also experience gastrointestinal (GI) distress symptoms such as diarrhea and vomiting, as well as hepatotoxicity and long term liver damage. Chemotherapy treatment has also been shown to induce peripheral neuropathy resulting in numbing, pain, and tingling sensations in the extremities of patients. Interestingly, researchers have discovered that this array of symptoms that cancer patients experience are interconnected and mediated by the inflammatory response.

The Efficacy of Levocarnitine Treatment in Relieving Fatigue in Patients with Cirrhosis but without Overt Hepatic Encephalopathy

Objective In the present study, we prospectively examined the efficacy of levocarnitine in relieving symptoms of fatigue in patients with cirrhosis but without overt hepatic encephalopathy. Methods Twenty-one cirrhotic patients who were able to undergo fatigue symptom evaluations at our institution were enrolled. A total of 12 cirrhotic patients underwent levocarnitine treatment (1,200-1,800 mg/day), while 9 did not undergo levocarnitine treatment. As primary endpoints, we investigated whether or not levocarnitine treatment exerted any beneficial effects by assessing the symptoms of fatigue [8-item Short-Form Health Survey (SF-8) and Fisk Fatigue Severity Score (FFSS)] at baseline and three months after treatment. Furthermore, as exploratory secondary endpoints, we investigated whether or not levocarnitine treatment exerted ameliorative effects on oxidative stress by assessing the serum thioredoxin (TRX) and urinary 8-hydroxydeoxyguanosine (8-OHdG) levels. Results The median age of the patients was 73 years old. Three men and 18 women were categorized by their Child-Pugh class (A and B in 14 and 7 patients, respectively). There were no significant differences in the clinical laboratory values between the two groups. The FFSS and SF-8 scores were significantly improved in the patients with cirrhosis who underwent levocarnitine treatment (p<0.01) but not in those who did not undergo levocarnitine treatment. Furthermore, three months after levocarnitine treatment, the serum carnitine concentrations were significantly increased, and the serum thioredoxin levels were decreased in the patients with cirrhosis who underwent levocarnitine treatment (p<0.05). Conclusion These results suggest that levocarnitine treatment may relieve symptoms of fatigue in cirrhotic patients by reducing oxidative stress.

The pathogenic potential of the combined action of chronic Opisthorchis felineus infection and repeated social defeat stress in C57BL/6 mice

Parasitic food-borne diseases and chronic social stress are frequent attributes of day-to-day human life. Therefore, our aim was to model the combined action of chronic Opisthorchis felineus infection and repeated social defeat stress in C57BL/6 mice. Histological examination of the liver revealed inflammation sites, pronounced periductal fibrosis, and cholangiofibrosis together with proliferation of bile ducts and hepatocyte dystrophy in the infected mice, especially in the stress-exposed ones. Simultaneously with liver pathology, we detected significant structural changes in the cerebral cortex. Immunohistochemical analysis of the hippocampus indicated the highest increase in numerical density of Iba 1-, IL-6-, iNOS-, and Arg1-positive cells in mice simultaneously subjected to the two adverse factors. The number of GFAP-positive cells rose during repeated social defeat stress, most strongly in the mice subjected to both infection and stress. Real-time PCR analysis showed that the expression of genes Aif1 and Il6 differed among the analysed brain regions (hippocampus, hypothalamus, and frontal cortex) and depended on the adverse factors applied. In addition, among the brain regions, there was no consistent increase or decrease in these parameters when the two adverse treatments were combined: (i) in the hippocampus, there was upregulation of Aif1 and no change in Il6 expression; (ii) in the hypothalamus, expression levels of Aif1 and Il6 were not different from controls; and (iii) in the frontal cortex, Aif1 expression did not change while Il6 expression increased. It can be concluded that a combination of two long-lasting adverse factors, O. felineus infection and repeated social defeat stress, worsens not only the hepatic but also brain state, as evidenced behaviorally by disturbances of the startle response in mice.

Food-grade titanium dioxide (E171) induces anxiety, adenomas in colon and goblet cells hyperplasia in a regular diet model and microvesicular steatosis in a high fat diet model

Food-grade titanium dioxide (E171) is a white additive widely used in solid and liquid food products. There is still debate about E171 toxic effects after oral consumption since this additive is deposited in colon, liver, spleen, testis and brain. The consumption of E171 commonly occurs with Western diets that are characterized by a high fat content. Thus, E171 could worsen adverse effects associated with a high fat diet (HFD) such as anxiety, colon diseases and testicular damage. We aimed to evaluate the effects of E171 on anxiety-like behavior, colon, liver and testis and to analyze if the administration of a HFD could exacerbate adverse effects. E171 was administered at ~5 mg/kg_bw by drinking water for 16 weeks and mice were fed with a Regular Diet or a HFD. E171 promoted anxiety, induced adenomas in colon, goblet cells hypertrophy and hyperplasia and mucins overexpression, but had no toxic effects on testicular tissue or spermatozoa in regular diet fed-mice. Additionally, E171 promoted microvesicular steatosis in liver in HFD fed-mice and the only HFD administration decreased the spermatozoa concentration and motility. In conclusion, E171 administration increases the number of adenomas in colon, induces hypertrophy and hyperplasia in goblet cells and microvesicular steatosis.

Arctigenin ameliorates depression-like behaviors in Toxoplasma gondii-infected intermediate hosts via the TLR4/NF-κB and TNFR1/NF-κB signaling pathways

Toxoplasma gondii (T. gondii) is a known neurotropic protozoan that remains in the central nervous system and induces neuropsychiatric diseases in intermediate hosts. Arctigenin (AG) is one of the major bioactive lignans of the fruit Arctium lappa L. and has a broad spectrum of pharmacological activities such as neuroprotective, anti-inflammatory and anti-T. gondii effects. However, the effect of AG against depressive behaviors observed in T. gondii-infected hosts has not yet been clarified. In the present study, we analyzed the effects of AG against T. gondii-induced depressive behaviors in intermediate hosts using a microglia cell line (BV2 cells) and brain tissues of BALB/c mice during the acute phase of infection with the RH strain of T. gondii. AG attenuated microglial activation and neuroinflammation via the Toll-like receptor/nuclear factor-kappa B (NF-κB) and tumor necrosis factor receptor 1/NF-κB signaling pathways, followed by up-regulating the dopamine and 5-hydroxytryptamine levels and inhibiting the depression-like behaviors of hosts. AG also significantly decreased the T. gondii burden in mouse brain tissues. In conclusion, we elucidated the effects and underlying molecular mechanisms of AG against depressive behaviors induced by T. gondii infection.

Ginsenoside Rg1 protects mice against streptozotocin-induced type 1 diabetic by modulating the NLRP3 and Keap1/Nrf2/HO-1 pathways

Ginseng has been traditionally used to treat diabetes mellitus (DM) in China. Ginsenoside Rg1 is a major active ingredient in processed ginseng, which elicits proven biological and pharmacological effects. Although a correlation between nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and predisposition to type 1 diabetes mellitus (T1DM) has been identified, the mechanism underlying the potential function and activation of NLRP3 inflammasome in DM have not been elucidated to date. The present study aimed to elucidate the effects and underlying mechanism of Rg1 on streptozotocin (STZ)-induced T1DM in mice through short or long-term observation. Concurrently, we intended to explore the relationships between inflammasome, pyroptosis and oxidative stress and the role of NLRP3 and Keap1/Nrf2/HO-1 pathways in the development and progression of DM. Using ELISA and Western blot analysis, we found that Rg1 attenuated abnormally elevated blood glucose, reduced inflammatory factors IL-1β and IL-18 in the blood, decreased ALT and AST levels, promoted insulin secretion, and weakened the function of NLRP3 in mouse liver and pancreas. In addition, Rg1 protected against STZ-induced reactive oxygen species-mediated inflammation by upregulating Nrf2/ARE pathway, which further activated antioxidant enzymes. Interestingly, Rg1 also regulated H3K9 methylation in liver and pancreas, as detected by immunohistochemistry. In summary, these data provide new understanding about the mechanism of Rg1 action, suggesting that it is a potential drug applied for preventing the occurrence and development of T1DM.

Sesame Lignans Suppress Age-Related Cognitive Decline in Senescence-Accelerated Mice

Sesame lignans, which are biologically active compounds present in sesame seeds and oil, are known to have neuroprotective effects in several models of brain dysfunction. However, the effects of sesame lignans on age-related brain dysfunction are not clear and were thus investigated in the present study using a senescence-accelerated mouse (SAMP10). Two-month-old male SAMP10 mice were administrated a basal diet with 0% or 0.05% sesame lignans for two months, or with 0%, 0.02%, or 0.05% sesame lignans for 10 months and subjected to step-through passive avoidance tasks and forced swim tests. Reactive carbonyl species (RCs) were evaluated as markers of oxidative stress using a recently developed comprehensive analytical method. Both learning time in passive avoidance tasks and immobile time in forced swim tests became longer with aging (p < 0.05). However, the administration of sesame lignans significantly ameliorated age-related effects in both tests (p < 0.05). Age-related increases in RCs such as 4-hydroxy-2-nonenal in the cerebral cortex and liver were reduced in mice fed sesame lignans. These results suggest that sesame lignans can prevent age-related brain dysfunction via anti-oxidative activity.

A literature review for the mechanisms of stress-induced liver injury

INTRODUCTION

Experimental studies and clinical observations have shown that stress can damage hepatic tissue both directly and indirectly. Many studies have partially revealed the contributors of stress-induced liver injury; however, the whole process has not yet been uncovered. This review aims to summarize the mechanisms that have been proposed to be involved.

METHODS

A literature search was conducted using PubMed (http://www.ncbi.nlm.nih.gov/pubmed) in its entirety up to March 2018, and analyzed the animal-derived mechanistic studies on stress-induced liver injury.

RESULTS

The liver is the organ that meets and filters a mass of alien material, and then maintains immune tolerance under physiological conditions. Under stress conditions, however, immune tolerance is interrupted, which results in the induction of inflammation in the liver. Contributors to this process can be categorized as follows: hypoxia-reoxygenation, over-activation of Kupffer cells and oxidative stress, influx of gut-derived lipopolysaccharide and norepinephrine, and over-production of stress hormones and activation of the sympathetic nerve.

CONCLUSIONS

Psychological stress is associated with a variety of pathological conditions resulting in liver injury through multiple systems, including the sympathetic nervous and adrenocortical system. Mechanistic understanding of this phenomenon is important for the clinical practice of managing patients with hepatic disorders and should be explored further in the future.

Fatigue in chronic liver disease: New insights and therapeutic approaches

The management of fatigue associated with chronic liver disease is a complex and major clinical challenge. Although fatigue can complicate many chronic diseases, it is particularly common in diseases with an inflammatory component. Fatigue can have both peripheral (i.e., neuromuscular) and central (i.e., resulting from changes in neurotransmission within the brain) causes. However, fatigue in chronic liver disease has strong social/contextual components and is often associated with behavioural alterations including depression and anxiety. Given the increasing awareness of patient-reported outcomes as important components of treatment outcomes and clinical research, there is a growing need to better understand and manage this poorly understood yet debilitating symptom. Although several pathophysiological mechanisms for explaining the development of fatigue have been generated, our understanding of fatigue in patients with chronic liver disease remains incomplete. A better understanding of the pathways and neurotransmitter systems involved may provide specific directed therapies. Currently, the management of fatigue in chronic liver disease can involve a combined use of methods to beneficially alter behavioural components and pharmacological interventions, of which several treatments have potential for the improved management of fatigue in chronic liver disease. However, evidence and consensus are lacking on the best approach and the most appropriate biochemical target(s) whilst clinical trials to address this issue have been few and limited by small sample size. In this review, we outline current understanding of the impact of fatigue and related symptoms in chronic liver disease, discuss theories of pathogenesis, and examine current and emerging approaches to its treatment.

Brain consequences of acute kidney injury: Focusing on the hippocampus

The high mortality rates associated with acute kidney injury are mainly due to extra-renal complications that occur following distant-organ involvement. Damage to these organs, which is commonly referred to as multiple organ dysfunction syndrome, has more severe and persistent effects. The brain and its sub-structures, such as the hippocampus, are vulnerable organs that can be adversely affected. Acute kidney injury may be associated with numerous brain and hippocampal complications, as it may alter the permeability of the blood-brain barrier. Although the pathogenesis of acute uremic encephalopathy is poorly understood, some of the underlying mechanisms that may contribute to hippocampal involvement include the release of multiple inflammatory mediators that coincide with hippocampus inflammation and cytotoxicity, neurotransmitter derangement, transcriptional dysregulation, and changes in the expression of apoptotic genes. Impairment of brain function, especially of a structure that has vital activity in learning and memory and is very sensitive to renal ischemic injury, can ultimately lead to cognitive and functional complications in patients with acute kidney injury. The objective of this review was to assess these complications in the brain following acute kidney injury, with a focus on the hippocampus as a critical region for learning and memory.

Sertraline ameliorates inflammation in CUMS mice and inhibits TNF-α-induced inflammation in microglia cells

Evidence indicates that inflammation plays a crucial role in depression. Therefore, new antidepressants might be identified by screening drugs for their anti-inflammatory actions. Sertraline hydrochloride (SERT), a widely used antidepressant, has anti-inflammatory effects in clinical studies, but the mechanism involved is unclear. In this study, we used cell and molecular biology to determine the possible anti-inflammatory mechanism of SERT in vivo and in vitro. Experimental data from the in vivo study showed that mice exposed to chronic unpredictable mild stress (CUMS) had significantly higher levels of major inflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin-1β [IL-1β] and inducible nitric oxide synthase [iNOS]) in peripheral and central tissues compared with the control group. Treatment of CUMS mice with SERT significantly reduced the levels of these inflammatory cytokines and inhibited the phosphorylation of nuclear factor-κB (NF-κB) and nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκB-α). Moreover, SERT reduced serum levels of transaminase in CUMS mice. Our in vitro study revealed that SERT suppressed TNF-α-induced NF-κB activation in a dose-dependent manner. SERT also inhibited the TNF-α-induced nuclear translocation of NF-κB by inhibiting IκB-α phosphorylation. Furthermore, SERT inhibited TNF-α-induced inflammatory cytokines in BV2 microglia cells. SERT directly bound to TNF-α and TNF-α receptor 1 (TNFR1) to potently block TNF-α/TNFR1-triggered signaling. These results indicate that SERT might treat depression by inhibiting the activation of microglia via the NF-κB signaling pathway. This study provides a basis for the research and development of antidepressants that act to reduce inflammation and the expression of inflammatory mediators.

Changes in the cerebral phosphotransfer network impair energetic homeostasis in an aflatoxin B1-contaminated diet

The phosphotransfer network system, through the enzymes creatine kinase (CK), adenylate kinase (AK), and pyruvate kinase (PK), contributes to efficient intracellular energetic communication between cellular adenosine triphosphate (ATP) consumption and production in tissues with high energetic demand, such as cerebral tissue. Thus, the aim of this study was to evaluate whether aflatoxin B₁ (AFB₁) intoxication in diet negatively affects the cerebral phosphotransfer network related to impairment of cerebral ATP levels in silver catfish (Rhamdia quelen). Brain cytosolic CK activity decreased in animals fed with a diet contaminated with AFB₁ on days 14 and 21 post-feeding, while mitochondrial CK activity increased, when compared to the control group (basal diet). Also, cerebral AK and PK activity decreased in animals fed with a diet contaminated with AFB₁ on days 14 and 21 post-feeding, similarly to the results observed for cerebral ATP levels. Based on this evidence, inhibition of cerebral cytosolic CK activity is compensated by stimulation of mitochondrial CK activity in an attempt to prevent impairment of communication between sites of ATP generation and ATP utilization. The inhibition of cerebral AK and PK activity leads to impairment of cerebral energy homeostasis, decreasing the brain's ATP availability. Moreover, the absence of a reciprocal compensatory mechanism between these enzymes contributes to cerebral energetic imbalance, which may contribute to disease pathophysiology.

Huanglian-Wendan Decoction Inhibits NF-κB/NLRP3 Inflammasome Activation in Liver and Brain of Rats Exposed to Chronic Unpredictable Mild Stress

Depression is a common mental disorder in modern society. A traditional Chinese medicine Huanglian-Wendan decoction with potential anti-inflammation is used as a clinical antidepressant. Our previous study showed central and peripheral inflammatory responses in a rat model of depression developed by chronic unpredictable mild stress (CUMS). Here, we investigated the anti-inflammatory activity and mechanism of Huanglian-Wendan decoction in CUMS rats. LC-MS/MS and HPLC were performed to determine the major compounds in water extract of this decoction. This study showed that Huanglian-Wendan decoction significantly increased sucrose consumption and reduced serum levels of interleukin-1 beta (IL-1β), IL-6, and alanine aminotransferase (ALT) in CUMS rats. Moreover, this decoction inhibited nuclear entry of nuclear factor-kappa B (NF-κB) with the reduction of phosphorylated protein of NF-κB (p-NF-κB) and inhibitor of NF-κB alpha (p-IκBα) and downregulated protein of nod-like receptor family pyrin domain-containing 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC), cysteinyl aspartate-specific proteinase-1 (Caspase-1), and IL-1β in liver and brain regions of CUMS rats. These findings demonstrated that Huanglian-Wendan decoction had antidepressant activity with hepatoprotection in CUMS rats coinciding with its anti-inflammation in both periphery and central. The inhibitory modulation of NF-κB and NLRP3 inflammasome activation by Huanglian-Wendan decoction may mediate its antidepressant action.

Silver ions are responsible for memory impairment induced by oral administration of silver nanoparticles

Increasing use of silver nanoparticles (AgNPs) results in increased human exposure. AgNPs are able to cross brain-blood barrier and are a risk factor for the brain. Thus, we hypothesized that AgNPs exposure might affect hippocampal dependent memory, which required cognitive coordination processes. To verify the assumption, in this study we evaluated the effects of orally administered bovine serum albumin (BSA)-coated AgNPs on spatial memory, which engage cognitive coordination processes for on-going stimuli segregation. Rats following 28 days of oral administration with 1 mg/kg (n = 10) or 30 mg/kg (n = 10) BSA-AgNPs or saline, a control groups (n = 10, n = 8), were tested with an active place avoidance task in the Carousel Maze test. The study revealed significant impairment of long- and short-term memory, irrespectively of dose of AgNPs, whereas non-cognitive activity was on a similar level. We found significantly higher content of silver in the hippocampus in comparison to the lateral cortex. No silver was found in the cerebellum and the frontal cortex. The nanoSIMS analysis reveal a weak signal of silver in the hippocampus of AgNPs treated animals that should be attributed to the presence of silver in ionic form rather than AgNPs. Our findings indicate that oral exposure to a low dose AgNPs induces detrimental effect on memory and cognitive coordination processes. The presence of silver ions rather than AgNPs in different brain regions, in particular the hippocampus, suggests crucial role of silver ions in AgNPs-induced impairment of the higher brain functions.

Fatigued Patients with Chronic Liver Disease Have Subtle Aberrations of Sleep, Melatonin and Cortisol Circadian Rhythms

AIMS

We sought to examine whether disturbances in central and peripheral circadian rhythms were related to the experience of fatigue in patients with chronic liver disease (CLD).

METHODS

Fatigued and non-fatigued patients with compensated CLD were enrolled in a prospective pilot study. Patients underwent a one week evaluation of free-living sleep and physical activity patterns, followed by a 24-hour admission, during which they underwent serial blood sampling, polysomnography, a 6-minute walk test and continuous core temperature measurements under standardized conditions. Blood samples were analyzed for liver tests, melatonin levels, lipids, and cortisol. Circadian rhythms were analyzed using single cosinor analyses.

RESULTS

Six fatigued and six non-fatigued patients were studied; five participants had cirrhosis. Fatigue severity was positively associated higher peak melatonin levels (rho=0.59, p=0.04) and a delay in night-time melatonin peak and inversely associated with sleep efficiency (rho=-0.63, p=0.04). Polysomnography, 6-minute walk test, and core temperature measurements did not differ significantly between the fatigued and non-fatigued patients. Although liver enzymes, bilirubin and albumin demonstrated a circadian pattern, it was not associated with fatigue. Fatigued patients showed a blunted and delayed cortisol rhythm and fatigue was strongly correlated with cortisol amplitude (rho=-0.77, p=0.004) and phase (r=-0.66, p=0.02).

CONCLUSION

Subtle aberrations in melatonin and adrenal circadian rhythms, as well as reduced sleep efficiency, likely contribute to fatigue in patients with CLD. These abnormalities may ultimately be a therapeutic target to improve quality of life for fatigued patients with CLD.