Omega-3 polyunsaturated fatty acids promote brain-to-blood clearance of ß-Amyloid in a mouse model with Alzheimer's disease.

Amyloid-ß (Aß) plaques is one of the typical pathological hallmark of Alzheimer disease (AD). Accumulating evidence suggests that the imbalance between Aß production and clearance leads to extracellular Aß accumulation in the brain. It is reported that the blood-brain barrier (BBB) transport plays a predominant role in Aß clearance from brain to blood. In the present study, we investigated dynamic alterations of BBB transport function in the early disease stage of AD using APPswe/PS1dE9 C57BL/6J (APP/PS1) transgenic mice. Our results showed that the expression of lipoprotein receptor-related protein 1 (LRP-1), a main efflux transporter of BBB, started to decrease at the age of 4 months old. Interestingly, supplementing with fish oil which is rich in omega-3 polyunsaturated fatty acids (PUFAs) significantly enhanced the expression level of LRP-1 and promoted Aß clearance from the bran to circulation, as revealed by reduced soluble/insoluble Aß levels and senile plaques in the brain parenchyma and a corresponding increase of Aß levels in plasma. Besides, fish oil supplement significantly inhibited the NF-κB activation, reduced the expression of interleukin-1ß and tumor necrosis factor-α, and suppressed the glial activation in APP/PS1 mice. The results of the study provide evidence that BBB transport function could be impaired at a very early disease stage, which might contribute to Aß pathological accumulation in AD, and omega-3 PUFAs intervention could be an effective strategy for the prevention of the progression of AD through promoting Aß clearance from brain-to-blood.

Fish oil treatment reduces chronic alcohol exposure induced synaptic changes.

Alcohol addiction is a chronic neuropsychiatric disorder that represents one of the most serious global public health problems. Yet, currently there still lacks an effective pharmacotherapy. Omega-3 polyunsaturated fatty acids (N-3 PUFAs) have exhibited beneficial effects in a variety of neurological disorders, particularly in reversing behavioral deficits and neurotoxicity induced by prenatal alcohol exposure and binge drinking. In the present study, we investigated if fish oil, which is rich in N-3 PUFAs, had beneficial effects on preventing relapse and alleviating withdrawal symptoms after chronic alcohol exposure. Our results demonstrated that fish oil significantly reduced the chronic alcohol exposure-induced aberrant dendritic morphologic changes of the medium-sized spiny neurons in the core and the shell of nucleus accumbens. This inhibited the expression of AMPAR2-lacking AMPARs and their accumulation on the post synaptic membranes of medium-sized spiny neurons and eventually alleviated withdrawal symptoms and alcohol dependence. Our study therefore suggests that N-3 PUFAs are promising for treating withdrawal symptoms and alcohol dependence.

The distinct manifestation of young-onset amyotrophic lateral sclerosis in China.

OBJECTIVE: Young-onset amyotrophic lateral sclerosis (ALS) refers to ALS patients with initial symptoms earlier than 45 years, representing a novel disease pattern. We aim to summarize the clinical and genetic features of 102 young-onset ALS patients in China. Methods: Clinical information and blood samples were collected from all registered patients, and we performed next generation sequencing techniques in an ALS customized panel to detect ALS-related genes. Results: A total of 95 sporadic ALS and seven familial ALS were involved in this study. Young-onset ALS showed male prevalence and had more spinal onset. With 44 patients carrying one or more variants, mutations in SPG11, ALS2, and SETX were the most frequent, followed by FUS variants. Other prevalent genes like SOD1, TARDBP, and C9ORF72 were relatively rare in young-onset patients. Conclusions: Our study highlighted distinct clinical manifestation and genetic background in young-onset ALS patients in China. These features should be verified in further investigations in other populations.

Fish oil protects the blood-brain barrier integrity in a mouse model of Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is ranked as the most prevalent neurodegenerative disease. However, the exact molecular mechanisms underlying pathophysiological alterations in AD remain unclear, especially at the prodromal stage. The decreased proteolytic degradation of Aß, blood-brain barrier (BBB) disruption, and neuroinflammation are considered to play key roles in the course of AD. METHODS: Male APPswe/PS1dE9 C57BL/6 J double-transgenic (APP/PS1) mice in the age range from 1 month to 6 months and age-matched wild type mice were used in this study, intending to investigate the expression profiles of Aß-degrading enzymes for Aß degradation activities and zonula occludens-1 (zo-1) for BBB integrity at the prodromal stage. RESULTS: Our results showed that there were no significant genotype-related alterations in mRNA expression levels of 4 well-characterized Aß-degrading enzymes in APP/PS1 mice within the ages of 6 months. Interestingly, a significant decrease in zo-1 expression was observed in APP/PS1 mice starting from the age of 5 months, suggesting that BBB disrupt occurs at an early stage. Moreover, treatment of fish oil (FO) for 4 weeks remarkably increased zo-1 expression and significantly inhibited the glial activation and NF-κB activation in APP/PS1 mice. CONCLUSION: The results of our study suggest that FO supplement could be a potential therapeutic early intervention for AD through protecting the BBB integrity and suppressing glial and NF-κB activation.

Circadian Rhythm Dysfunction Accelerates Disease Progression in a Mouse Model With Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease caused by interactions between environmental factors and genetic susceptibility. Circadian rhythm dysfunction (CRD) is a significant contributor to neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease. However, whether CRD contributes to the progression of ALS remains little known. We performed behavioral and physiological tests on SOD1G93A ALS model mice with and without artificially induced CRD, and on wild-type controls; we also analyzed spinal cord samples histologically for differences between groups. We found that CRD accelerated the disease onset and progression of ALS in model mice, as demonstrated by aggravated functional deficits and weight loss, as well as increased motor neuron loss, activated gliosis, and nuclear factor κB-mediated inflammation in the spinal cord. We also found an increasing abundance of enteric cyanobacteria in the ALS model mice shortly after disease onset that was further enhanced by CRD. Our study provides initial evidence on the CRD as a risk factor for ALS, and intestinal cyanobacteria may be involved.