Exercise Your Amyloid

Effects of MicroRNAs and Long Non-coding RNAs on Beneficial Action of Exercise on Cognition in Degenerative Diseases: A Review

Recent research has exposed a growing body of proof underscoring the importance of microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) in maintaining the physical composition of neurons and influencing cognitive functioning in both standard and atypical circumstances. Extensive research has been conducted on the possible application of miRNAs and lncRNAs as biomarkers for various diseases, with a particular focus on brain disorders, as they possess remarkable durability in cell-free surroundings and can endure repeated freezing and thawing processes. It is intriguing to note that miRNAs and lncRNAs have the ability to function through paracrine mechanisms, thereby playing a role in communication between different organs. Recent research has proposed that the improvement of cognitive abilities through physical exercise in mentally healthy individuals is a valuable method for uncovering potential connections between miRNAs, or microRNAs, and lncRNAs, and human cognitive function. The process of cross-correlating data from disease models and patients with existing data will be crucial in identifying essential miRNAs and lncRNAs, which can potentially act as biomarkers or drug targets in the treatment of cognitive disorders. By combining this method with additional research in animal models, we can determine the function of these molecules and their potential impact on therapy. This article discusses the latest research about the primary miRNAs, lncRNAs, and their exosomes that are affected by physical activity in terms of human cognitive function.

Understanding the molecular basis of resilience to Alzheimer's disease

The cellular and molecular distinction between brain aging and neurodegenerative disease begins to blur in the oldest old. Approximately 15-25% of observations in humans do not fit predicted clinical manifestations, likely the result of suppressed damage despite usually adequate stressors and of resilience, the suppression of neurological dysfunction despite usually adequate degeneration. Factors during life may predict the clinico-pathologic state of resilience: cardiovascular health and mental health, more so than educational attainment, are predictive of a continuous measure of resilience to Alzheimer's disease (AD) and AD-related dementias (ADRDs). In resilience to AD alone (RAD), core features include synaptic and axonal processes, especially in the hippocampus. Future focus on larger and more diverse cohorts and additional regions offer emerging opportunities to understand this counterforce to neurodegeneration. The focus of this review is the molecular basis of resilience to AD.

[Course modifying therapy of Alzheimer's dementia]

The current therapy of Alzheimer's disease is primarily symptomatic. Drugs which aim to modify the course of the disease are currently being developed and tested in clinical trials. Given the complex and partly unknown pathogenesis of the disease, failure of such forms of therapy has to be taken into account. Clinical epidemiology suggests a possible neuroprotective effect of statins and non-steroidal anti-inflammatory drugs, however, the molecular basis of these effects has to be further unraveled. Therapies that modify the course of Alzheimer's disease are only likely to be effective years if not decades before the disease becomes clinically apparent. Thus, the therapy of risk factors including arterial hypertension and obesity in midlife as well as a Mediterranean diet currently provides the highest chance of modifying the course of the disease.

Molecular aspects of adrenal regulation for circadian glucocorticoid synthesis by chronic voluntary exercise

Chronic voluntary running of mice is known to increase the circadian peak of plasma corticosterone without change in the level of adrenocorticotropic hormone (ACTH). In order to investigate how chronic exercise modulates the circadian HPA axis, we used two weeks of voluntary wheel running of mice and confirmed the significant increase of the circadian peak of plasma corticosterone without alteration in ACTH level. To elucidate the mechanisms of exercise modulation on corticosterone synthesis, we first examined the levels of transcripts involved in corticosterone synthesis of the adrenal gland. Among them, only steroidogenic acute regulatory protein (StAR), the rate-limiting factor that transfers substrate cholesterol into inner mitochondrial membrane, showed significantly higher expression in the exercise group. Since the splanchnic nerve input to the adrenal gland has been reported as a factor involved in the direct modulation of corticosterone synthesis, we next examined the expression levels of enzymes for the catecholamine synthesis as indices of sympatho-adrenomedullary activity. We found that the only rate-limiting enzyme, tyrosine hydroxylase (TH), was significantly higher in the adrenals of exercise group. In addition to the increment of StAR and TH mRNA in response to the chronic exercise, surprisingly, we found only these factors showed the circadian variation in its expression levels that was correlated to the circadian rhythm of corticosterone. Chronic exercise seems to alter the circadian corticosterone synthesis, at least partially via altering the levels of circadian-regulated transcripts, StAR and TH of the adrenal gland.

Moderate consumption of Cabernet Sauvignon attenuates Abeta neuropathology in a mouse model of Alzheimer's disease

Recent studies suggest that moderate red wine consumption reduces the incidence of Alzheimer's disease (AD) clinical dementia. Using Tg2576 mice, which model AD-type amyloid beta-protein (Abeta) neuropathology, we tested whether moderate consumption of the red wine Cabernet Sauvignon modulates AD-type neuropathology and cognitive deterioration. The wine used in the study was generated using Cabernet Sauvignon grapes from Fresno, California, and was delivered to Tg2576 in a final concentration of approximately 6% ethanol. We found that Cabernet Sauvignon significantly attenuated AD-type deterioration of spatial memory function and Abeta neuropathology in Tg2576 mice relative to control Tg2576 mice that were treated with either a comparable amount of ethanol or water alone. Chemical analysis showed the Cabernet Sauvignon used in this study contains a very low content of resveratrol (0.2 mg/L), 10-fold lower than the minimal effective concentration shown to promote Abeta clearance in vitro. Our studies suggest Cabernet Sauvignon exerts a beneficial effect by promoting nonamyloidogenic processing of amyloid precursor protein, which ultimately prevents the generation of Abeta peptides. This study supports epidemiological evidence indicating that moderate wine consumption, within the range recommended by the FDA dietary guidelines of one drink per day for women and two for men, may help reduce the relative risk for AD clinical dementia.

Technology Insight: querying the genome with microarrays--progress and hope for neurological disease

The ability to perform large-scale analysis of the genome at the level of gene sequence, gene copy number and messenger RNA transcript expression characterizes the post-genomic era. In the past decade, the microarray-based approach has emerged as one of the major tools in this area of genome biology, contributing to advances in the understanding of Mendelian and complex neurological disorders. Despite technical issues regarding design, data analysis and validation that have to be addressed in the planning and interpretation of a microarray study, microarray-based approaches for studying transcript expression, single-nucleotide-polymorphism genotyping and gene resequencing are becoming more widely adopted. Genomic microarrays are providing an unprecedented opportunity to dissect the genetic risk for complex neurological disorders. Numerous clinical and preclinical applications are likely to dominate the ambitious microarray agenda within the next decade.

Enriched environments, experience-dependent plasticity and disorders of the nervous system

Behavioural, cellular and molecular studies have revealed significant effects of enriched environments on rodents and other species, and provided new insights into mechanisms of experience-dependent plasticity, including adult neurogenesis and synaptic plasticity. The demonstration that the onset and progression of Huntington's disease in transgenic mice is delayed by environmental enrichment has emphasized the importance of understanding both genetic and environmental factors in nervous system disorders, including those with Mendelian inheritance patterns. A range of rodent models of other brain disorders, including Alzheimer's disease and Parkinson's disease, fragile X and Down syndrome, as well as various forms of brain injury, have now been compared under enriched and standard housing conditions. Here, we review these findings on the environmental modulators of pathogenesis and gene-environment interactions in CNS disorders, and discuss their therapeutic implications.