Differential Relevance of NF-κB and JNK in the Pathophysiology of Hemorrhage/Resususcitation-Induced Liver Injury after Chronic Ethanol Feeding

Causal roles of stress kinase JNK2 in DNA methylation and binge alcohol withdrawal-evoked behavioral deficits

Excessive binge alcohol intake is a common drinking pattern in humans, especially during holidays. Cessation of the binge drinking often leads to aberrant withdrawal behaviors, as well as serious heart rhythm abnormalities (clinically diagnosed as Holiday Heart Syndrome (HHS)). In our HHS mouse model with well-characterized binge alcohol withdrawal (BAW)-induced heart phenotypes, BAW leads to anxiety-like behaviors and cognitive impairment. We have previously reported that stress-activated c-Jun NH(2)-terminal kinase (JNK) plays a causal role in BAW-induced heart phenotypes. In the HHS brain, we found that activation of JNK2 (but not JNK1 and JNK3) in the prefrontal cortex (PFC), but not hippocampus and amygdala, led to anxiety-like behaviors and impaired cognition. DNA methylation mediated by a crucial DNA methylation enzyme, DNA methyltransferase1 (DNMT1), is known to be critical in alcohol-associated behavioral deficits. In HHS mice, JNK2 in the PFC (but not hippocampus and amygdala) causally enhanced total genomic DNA methylation via increased DNMT1 expression, which was regulated by enhanced binding of JNK downstream transcriptional factor c-JUN to the DNMT1 promoter. JNK2-specific inhibition either by an inhibitor JNK2I or JNK2 knockout completely offset c-JUN-regulated DNMT1 upregulation and restored the level of DNA methylation in HHS PFC to the baseline levels seen in sham controls. Strikingly, either JNK2-specific inhibition or genetic JNK2 depletion or DNMT1 inhibition (by an inhibitor 5-Azacytidine) completely abolished BAW-evoked behavioral deficits. In conclusion, our studies revealed a novel mechanism by which JNK2 drives BAW-evoked behavioral deficits through a DNMT1-regulated DNA hypermethylation. JNK2 could be a novel therapeutic target for alcohol withdrawal treatment and/or prevention.

JNK3 as Therapeutic Target and Biomarker in Neurodegenerative and Neurodevelopmental Brain Diseases

The c-Jun N-terminal kinase 3 (JNK3) is the JNK isoform mainly expressed in the brain. It is the most responsive to many stress stimuli in the central nervous system from ischemia to Aβ oligomers toxicity. JNK3 activity is spatial and temporal organized by its scaffold protein, in particular JIP-1 and β-arrestin-2, which play a crucial role in regulating different cellular functions in different cellular districts. Extensive evidence has highlighted the possibility of exploiting these adaptors to interfere with JNK3 signaling in order to block its action. JNK plays a key role in the first neurodegenerative event, the perturbation of physiological synapse structure and function, known as synaptic dysfunction. Importantly, this is a common mechanism in many different brain pathologies. Synaptic dysfunction and spine loss have been reported to be pharmacologically reversible, opening new therapeutic directions in brain diseases. Being JNK3-detectable at the peripheral level, it could be used as a disease biomarker with the ultimate aim of allowing an early diagnosis of neurodegenerative and neurodevelopment diseases in a still prodromal phase.

Cerebral Hemorrhage and Alcohol Exposure: A Review

Aims

To investigate the dose–response relationships between alcohol and intracerebral hemorrhage (ICH), the impact of alcohol on the outcome of ICH and possible mechanisms underlying hypertensive ICH (HICH) caused by heavy drinking.

Methods

Literature search from 1985 to August 2019 in the PubMed database.

Results

The relationship between low-middle alcohol consumption and ICH remains controversial for various reasons, whereas chronic heavy drinking increases the incidence of ICH and exerts worse outcome. More attention is needed to clarify the characteristics of chronic alcohol intake and binge drinking. Chronic alcohol abuse tends to elevates blood pressure, resulting in increased occurrence of HICH and exaggerated HICH-contributed brain injury.

Conclusion

It is important to develop strategies to promote reasonable intake categories, prevent alcoholism and thus reduce the risk of ICH.

Innate Immunity and Alcohol

The innate immunity has evolved during millions of years, and thus, equivalent or comparable components are found in most vertebrates, invertebrates, and even plants. It constitutes the first line of defense against molecules, which are either pathogen-derived or a danger signal themselves, and not seldom both. These molecular patterns are comprised of highly conserved structures, a common trait in innate immunity, and constitute very potent triggers for inflammation mediated via extracellular or intracellular pattern recognition receptors. Human culture is often interweaved with the consumption of alcohol, in both drinking habits, its acute or chronical misuse. Apart from behavioral effects as often observed in intoxicated individuals, alcohol consumption also leads to immunological modulation on the humoral and cellular levels. In the last 20 years, major advances in this field of research have been made in clinical studies, as well as in vitro and in vivo research. As every physician will experience intoxicated patients, it is important to be aware of the changes that this cohort undergoes. This review will provide a summary of the current knowledge on the influence of alcohol consumption on certain factors of innate immunity after a hit, followed by the current studies that display the effect of alcohol with a description of the model, the mode of alcohol administration, as well as its dose. This will provide a way for the reader to evaluate the findings presented.

Role of Stress Kinase JNK in Binge Alcohol-Evoked Atrial Arrhythmia

BACKGROUND

Excessive binge alcohol drinking has acute cardiac arrhythmogenic effects, including promotion of atrial fibrillation (AF), which underlies "Holiday Heart Syndrome." The mechanism that couples binge alcohol abuse with AF susceptibility remains unclear. We previously reported stress-activated c-Jun N-terminal kinase (JNK) signaling contributes to AF development. This is interesting because JNK is implicated in alcohol-caused organ malfunction beyond the heart.

OBJECTIVES

The purpose of this study was to detail how JNK promotes binge alcohol-evoked susceptibility to AF.

METHODS

The authors found binge alcohol-exposure leads to activated JNK, specifically JNK2. Furthermore, binge alcohol induces AF (24- vs. 1.8-Hz burst pacing-induced episodes per attempt per animal), higher incidence of diastolic intracellular Ca2+ activity (Ca2+ waves, sarcoplasmic reticulum [SR] Ca2+ leakage), and membrane voltage (Vm) and systolic Ca2+ release spatiotemporal heterogeneity (ΔtVm-Ca). These changes were completely eliminated by JNK inhibition both in vivo and in vitro. calmodulin kinase II (CaMKII) is a proarrhythmic molecule known to drive SR Ca2+ mishandling.

RESULTS

The authors report for the first time that binge alcohol activates JNK2, which subsequently phosphorylates the CaMKII protein, enhancing CaMKII-driven SR Ca2+ mishandling. CaMKII inhibition eliminates binge alcohol-evoked arrhythmic activities.

CONCLUSIONS

Our studies demonstrate that binge alcohol exposure activates JNK2 in atria, which then drives CaMKII activation, prompting aberrant Ca2+ waves and, thus, enhanced susceptibility to atrial arrhythmia. Our results reveal a previously unrecognized form of alcohol-driven kinase-on-kinase proarrhythmic crosstalk. Atrial JNK2 function represents a potential novel therapeutic target to treat and/or prevent AF.

Antifatigue Effects of Antrodia cinnamomea Cultured Mycelium via Modulation of Oxidative Stress Signaling in a Mouse Model

Antrodia cinnamomea, a folk medicinal mushroom, has numerous biological effects. In this study, we aim to assess whether the antifatigue effects of A. cinnamomea mycelia (AC) and its underlying mechanisms are related to oxidative stress signaling using behavioral mouse models and biochemical indices detection. Mice were orally treated with AC at doses of 0.1, 0.3, and 0.9 g/kg for three weeks. AC had no effect on the spontaneous activities of mice indicating its safety on central nervous system. Furthermore, results obtained from weight-loaded forced swimming test, rotary rod test, and exhausted running test confirmed that AC significantly enhanced exercise tolerance of mice. Biochemical indices levels showed that these effects were closely correlated with inhibiting the depletion of glycogen and adenosine triphosphate stores, regulating oxidative stress-related parameters (superoxide dismutase, glutathione peroxidase, reactive oxygen species, and malondialdehyde) in serum, skeletal muscle, and liver of mice. Moreover, the effects of AC may be related with its regulation on the activations of AMP-activated protein kinase, protein kinase B, and mammalian target of rapamycin in liver and skeletal muscle of mice. Altogether, our data suggest that the antifatigue properties of AC may be one such modulation mechanism via oxidative stress-related signaling in mice.

Hepatoprotective Effects of Antrodia cinnamomea: The Modulation of Oxidative Stress Signaling in a Mouse Model of Alcohol-Induced Acute Liver Injury

In the present study, the components of A. cinnamomea (AC) mycelia were systematically analyzed. Subsequently, its hepatoprotective effects and the underlying mechanisms were explored using a mouse model of acute alcohol-induced liver injury. AC contained 25 types of fatty acid, 16 types of amino acid, 3 types of nucleotide, and 8 types of mineral. The hepatoprotective effects were observed after 2 weeks of AC treatment at doses of 75 mg/kg, 225 mg/kg, and 675 mg/kg in the mouse model. These effects were indicated by the changes in the levels of aspartate aminotransferase, alanine aminotransferase, several oxidation-related factors, and inflammatory cytokines in serum and/or liver samples. AC reduced the incidence rate of necrosis, inflammatory infiltration, fatty droplets formation, and cell apoptosis in liver detecting via histological and TUNEL assay. In addition, AC reduced the expression of cleaved caspase-3, -8, and -9 and the levels of phosphor-protein kinase B (Akt) and phosphor-nuclear factor-κB (NF-κB) in the liver samples. Collectively, AC-mediated hepatoprotective effects in a mouse model of acute alcohol-induced liver injury are the result of reduction in oxidative stress. This may be associated with Akt/NF-κB signaling. These results provide valuable evidence to support the use of A. cinnamomea as a functional food and/or medicine.