Amelioration of Parkinson's disease by pharmacological inhibition and knockdown of redox sensitive TRPC5 channels: Focus on mitochondrial health

A Comprehensive Stereology Method for Quantitative Evaluation of Neuronal Injury, Neurodegeneration, and Neurogenesis in Brain Disorders

Neuronal injury, neurodegeneration, and neuroanatomical changes are key pathological features of various neurological disorders, including epilepsy, stroke, traumatic brain injury, Parkinson's disease, autism, and Alzheimer's disease. Accurate quantification of neurons and interneurons in different brain regions is critical for understanding the progression of neurodegenerative disorders in animal models. Traditional scoring methods are often superficial, biased, and unreliable for evaluating neuropathology. Stereology, a quantitative tool that uses 3-dimensional visualization of cells, provides a robust protocol for evaluating neuronal injury and neurodegeneration. This article presents a comprehensive and optimized stereology protocol for unbiased quantification of neuronal injury, neurodegeneration, and neurogenesis in rat and mouse models. This protocol involves precise counting of injured neurons, surviving neurons, and interneurons through immunohistochemical processing of brain sections for NeuN(+) principal neurons, parvalbumin (PV+) interneurons, doublecortin (DCX+) newborn neurons, and Fluoro-Jade B (FJB+)-stained injured cells. Predefined hippocampal and amygdala regions were identified and analyzed using a Visiopharm stereology software-driven compound microscope. Cell density and absolute cell numbers were determined using the optical fractionation method. Our stereology protocol accurately estimated 1.5 million total NeuN(+) principal neurons and 0.05 million PV(+) interneurons in the rat hippocampus, as well as 1.2 million total principal neurons and 0.025 million interneurons in the mouse hippocampus. FJB(+) counting provided a quantitative index of damaged neurons, and the stereology of DCX(+) neurons demonstrated the extent of neurogenesis. Overall, this stereology protocol enables precise, accurate, and unbiased counting of total neurons in any brain region. This offers a reliable quantitative tool for studying neuronal injury and protection in various models of acute brain injury, neurotoxicity, and chronic neurological disorders. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Stereological quantification of principal neurons, interneurons, and immature neurons in the hippocampus in rat brain sections Basic Protocol 2: Stereological quantification of principal neurons, interneurons, and immature neurons in the hippocampus in mouse brain sections Basic Protocol 3: Stereological quantification of injured or necrotized cells stained with Fluoro-Jade B in the hippocampus and amygdala in rats Basic Protocol 4: Stereological quantification of injured or necrotized cells stained with Fluoro-Jade B in the hippocampus and amygdala regions in mice Basic Protocol 5: Brain fixation and histology processing Basic Protocol 6: Immunochemistry of principal neurons, interneurons, and newborn neurons Basic Protocol 7: Fluoro-Jade B staining of injured neurons.

Drug Development for Alzheimer's and Parkinson's Disease: Where Do We Go Now?

Neurodegenerative diseases (NDs) are a set of progressive, chronic, and incurable diseases characterized by the gradual loss of neurons, culminating in the decline of cognitive and/or motor functions. Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common NDs and represent an enormous burden both in terms of human suffering and economic cost. The available therapies for AD and PD only provide symptomatic and palliative relief for a limited period and are unable to modify the diseases' progression. Over the last decades, research efforts have been focused on developing new pharmacological treatments for these NDs. However, to date, no breakthrough treatment has been discovered. Hence, the development of disease-modifying drugs able to halt or reverse the progression of NDs remains an unmet clinical need. This review summarizes the major hallmarks of AD and PD and the drugs available for pharmacological treatment. It also sheds light on potential directions that can be pursued to develop new, disease-modifying drugs to treat AD and PD, describing as representative examples some advances in the development of drug candidates targeting oxidative stress and adenosine A2A receptors.

Association between urinary metals and prostate-specific antigen in aging population with depression: a cross-sectional study

Objective

This study aims to investigate the impact of depression and urinary metals on Prostate-Specific Antigen (PSA).

Methods

Analysis was conducted on 1901 samples collected from the National Health and Nutrition Examination Survey (NHANES) database between 2001 and 2010. Analytical methods included stepwise multiple linear regression (MLR) analysis of the overall population's urinary metals and PSA relationship, analysis of urinary metals and PSA relationship in older adults and BMI subgroups, analysis of urinary metals and PSA relationship in the depressed population, and restricted cubic spline (RCS) analysis. A significance level of p < 0.05 was considered statistically significant.

Results

In the stepwise multiple linear regression, beryllium (Be) showed a dose-response association with PSA (third quartile: β = 0.05, 95%CI (0.02, 0.09); fourth quartile: β = 0.07, 95%CI (0.02, 0.12), p trend = 0.048). Subgroup analysis indicated that in individuals aged >60, Be at Q4 level [β = 0.09, 95%CI (0.05, 0.21)] exhibited a dose-response correlation with PSA. In the population with 25 ≤ BMI < 30, Be might more significantly elevate PSA, with Q4 level having a pronounced impact on PSA levels [β = 0.03, 95%CI (0.02, 1.27)]. In the depressed population, urinary cadmium (Cd) levels showed a significant positive dose-response relationship, with Q4 level of Cd having the maximum impact on PSA [β = 0.3, 95%CI (0.09, 0.49)].

Conclusion

Individuals exposed to beryllium (Be), especially the older adults and overweight, should monitor their PSA levels. In depressed patients, cadmium (Cd) levels may further elevate PSA levels, necessitating increased monitoring of PSA levels among males.

Effect of Clemizole on Alpha-Synuclein-Preformed Fibrils-Induced Parkinson's Disease Pathology: A Pharmacological Investigation

Parkinson's disease (PD) is a neurodegenerative disorder associated with mitochondrial dysfunctions and oxidative stress. However, to date, therapeutics targeting these pathological events have not managed to translate from bench to bedside for clinical use. One of the major reasons for the lack of translational success has been the use of classical model systems that do not replicate the disease pathology and progression with the same degree of robustness. Therefore, we employed a more physiologically relevant model involving alpha-synuclein-preformed fibrils (PFF) exposure to SH-SY5Y cells and Sprague Dawley rats. We further explored the possible involvement of transient receptor potential canonical 5 (TRPC5) channels in PD-like pathology induced by these alpha-synuclein-preformed fibrils with emphasis on amelioration of oxidative stress and mitochondrial health. We observed that alpha-synuclein PFF exposure produced neurobehavioural deficits that were positively ameliorated after treatment with the TRPC5 inhibitor clemizole. Furthermore, Clemizole also reduced p-alpha-synuclein and diminished oxidative stress levels which resulted in overall improvements in mitochondrial biogenesis and functions. Finally, the results of the pharmacological modulation were further validated using siRNA-mediated knockdown of TRPC5 channels, which also decreased p-alpha-synuclein expression. Together, the results of this study could be superimposed in the future for exploring the beneficial effects of TRPC5 channel modulation for other neurodegenerative disorders and synucleopathies.

Supplementation of probiotic Bifidobacterium breve Bif11 reverses neurobehavioural deficits, inflammatory changes and oxidative stress in Parkinson's disease model

Human gut microbiota are thought to affect different physiological processes in the body, including brain functions. Gut dysbiosis has been linked to the progression of Parkinson's disease (PD) and thus, restoring the healthy gut microbiota with supplementation of putative probiotic strains can confer some benefits in PD. In the current study, we explored the neuroprotective potential of Bifidobacterium breve Bif11 supplementation in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine hydrochloride (MPTP) treated female Sprague Dawley rats. This study investigated the behavioural, molecular and biochemical parameters in the MPTP rat model. A pharmacological intervention of Bif11 at doses of 1 × 1010 CFU and 2 × 1010 CFU for 21 days was found to attenuate the cognitive and motor changes in the MPTP rat model. Furthermore, it also increased the tyrosine hydroxylase levels, reduced pro-inflammatory markers and decreased oxidative and nitrosative stress in the mid brain of MPTP-lesioned rats. Bif11 supplementation even restored the levels of short-chain fatty acids and decreased intestinal epithelial permeability in MPTP-induced PD model rats. In summary, these findings demonstrate that B. breve Bif11 has the potential to ameliorate symptoms of PD. However, this therapy needs to be further investigated with in-depth mechanistic insights in the future for the treatment of PD.

Mitochondrial dysfunction and neurological disorders: A narrative review and treatment overview

Mitochondria play a vital role in the nervous system, as they are responsible for generating energy in the form of ATP and regulating cellular processes such as calcium (Ca2+) signaling and apoptosis. However, mitochondrial dysfunction can lead to oxidative stress (OS), inflammation, and cell death, which have been implicated in the pathogenesis of various neurological disorders. In this article, we review the main functions of mitochondria in the nervous system and explore the mechanisms related to mitochondrial dysfunction. We discuss the role of mitochondrial dysfunction in the development and progression of some neurological disorders including Parkinson's disease (PD), multiple sclerosis (MS), Alzheimer's disease (AD), depression, and epilepsy. Finally, we provide an overview of various current treatment strategies that target mitochondrial dysfunction, including pharmacological treatments, phototherapy, gene therapy, and mitotherapy. This review emphasizes the importance of understanding the role of mitochondria in the nervous system and highlights the potential for mitochondrial-targeted therapies in the treatment of neurological disorders. Furthermore, it highlights some limitations and challenges encountered by the current therapeutic strategies and puts them in future perspective.