Integrated insight into the molecular mechanisms of selenium-modulated, MPP+-induced cytotoxicity in a Parkinson's disease model

Food and Food Waste Antioxidants: Could They Be a Potent Defence against Parkinson's Disease?

Oxidative stress, an imbalance between reactive oxygen species (ROS) and endogenous antioxidants, plays an important role in the development of neurodegenerative diseases, including Parkinson's. The human brain is vulnerable to oxidative stress because of the high rate of oxygen that it needs and the high levels of polyunsaturated fatty acids, which are substrates of lipid peroxidation. Natural antioxidants inhibit oxidation and reduce oxidative stress, preventing cancer, inflammation, and neurodegenerative disorders. Furthermore, in the literature, it is reported that antioxidants, due to their possible neuroprotective activity, may offer an interesting option for better symptom management, even Parkinson's disease (PD). Natural antioxidants are usually found in several foods, such as fruits, vegetables, meat, fish, and oil, and in food wastes, such as seeds, peels, leaves, and skin. They can help the system of endogenous antioxidants, protect or repair cellular components from oxidative stress, and even halt lipid, protein, and DNA damage to neurons. This review will examine the extent of knowledge from the last ten years, about the neuroprotective potential effect of natural antioxidants present in food and food by-products, in in vivo and in vitro PD models. Additionally, this study will demonstrate that the pool of dietary antioxidants may be an important tool in the prevention of PD and an opportunity for cost savings in the public health area.

Association of dietary selenium intake and all-cause mortality of Parkinson's disease and its interaction with blood cadmium level: a retrospective cohort study

BACKGROUND

Parkinson's disease (PD) is a slowly progressive neurodegenerating disease that may eventually lead to disabling condition and pose a threat to the health of aging populations. This study aimed to explore the association of two potential risk factors, selenium and cadmium, with the prognosis of Parkinson's disease as well as their interaction effect.

METHODS

Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 to 2015-2016 and National Death Index (NDI). Participants were classified as Parkinson's patients by self-reported anti-Parkinson medications usage. Cox regression models and restricted cubic spline models were applied to evaluate the association between PD mortality and selenium intake level as well as blood cadmium level. Subgroup analysis was also conducted to explore the interaction between them.

RESULTS

A total of 184 individuals were included. In full adjusted cox regression model (adjusted for age, gender, race, hypertension, pesticide exposure, smoking status and caffeine intake), compared with participants with low selenium intake, those with normal selenium intake level were significantly associated with less risk of death (95%CI: 0.18-0.76, P = 0.005) while no significant association was found between low selenium intake group and high selenium group (95%CI: 0.16-1.20, P = 0.112). Restricted cubic spline model indicated a nonlinear relationship between selenium intake and PD mortality (P for nonlinearity = 0.050). The association between PD mortality and blood cadmium level was not significant (95%CI: 0.19-5.57, P = 0.112). However, the interaction term of selenium intake and blood cadmium showed significance in the cox model (P for interaction = 0.048). Subgroup analysis showed that the significant protective effect of selenium intake existed in populations with high blood cadmium but not in populations with low blood cadmium.

CONCLUSION

Moderate increase of selenium intake had a protective effect on PD mortality especially in high blood cadmium populations.

Programmed cell death 4 blocks autophagy and promotes dopaminergic neuronal injury in Parkinson's disease

Dysregulation of autophagy has previously been associated with the formation of toxic proteins, such as α-synuclein, in patients with Parkinson's disease (PD). In addition, it has been indicated that programmed cell death 4 (PDCD4) can inhibit autophagy in certain conditions, such as diabetic nephropathy, atherosclerosis and cardiac hypertrophy. Therefore, the hypothesis that PDCD4 can promote dopaminergic neuron damage through autophagy was proposed. To explore this hypothesis, the present study treated human neuroblastoma SK-N-SH cells with 1-methyl-4-phenylpyridinium (MPP+) to establish an in vitro model of PD. The potential effects of PDCD4 knockdown on lactate dehydrogenase (LDH) release, cell apoptosis, inflammatory response, oxidative stress and autophagy were then evaluated in this model of PD using an LDH assay kit, flow cytometry, western blotting, ELISA and immunofluorescence. The autophagy inhibitor 3-methyladenine (3-MA) was also applied to treat these cells, and its effects on these aforementioned parameters following PDCD4 knockdown were assessed. MPP+ was shown to increase the expression levels of PDCD4 in SK-N-SH cells. PDCD4 knockdown was revealed to suppress LDH release, cell apoptosis, secretion of inflammatory factors and oxidative stress. In addition, PDCD4 knockdown was demonstrated to enhance autophagy in cells treated with MPP+. By contrast, 3-MA treatment reversed the aforementioned effects of PDCD4 knockdown on cells, suggesting autophagy to be among the processes regulated by PDCD4 in SK-N-SH cells. The results of the present study suggested the existence of regulatory effects mediated by PDCD4 on autophagy in MPP+-induced SK-N-SH cells, offering potential future targets for PD therapy.

Clinical and Economic Insights into Parkinson's Disease Hospitalization: A Comprehensive Study of 19,719 Inpatient Cases in Hubei Province, China

OBJECTIVE

Parkinson's disease (PD) is a profoundly incapacitating neurodegenerative disorder, which presents a substantial challenge to the economic sustainability of the global healthcare system. The present study seeks to clarify the factors that contribute to the costs associated with PD hospitalization and analyze the economic burden it imposes.

METHODS

We examined data of 19,719 patients with a primary diagnosis of PD who were admitted to hospitals in Hubei Province, China, during the study period. Healthcare data were obtained from the database of electronic medical records. The study presents a comprehensive analysis of the demographic characteristics and investigates the factors that affect their healthcare expenditure.

RESULTS

The cohort consisted of 10,442 (53.0%) males and 9,277 (47.0%) females. The age-group of 66-70 years experienced the highest incidence of hospitalization among PD patients, with a mortality rate of 0.76‰. The average length of stay for patients was 9.9 ± 8.6 days and the average cost per patient was USD 1,759.9 ± 4,787.7. Surgical interventions were conducted on a mere 2.0% of the total inpatient population. The primary cost component for these interventions was material expenses, accounting for 70.1% of the total. Non-surgical patients primarily incurred expenses related to diagnosis and medication. Notably, surgical patients faced a substantial out-of-pocket rate, reaching up to 90.6%. Surgery was identified as the most influential factor that negatively affected both length of stay and hospitalization costs. Inpatients exhibited significant associations with prolonged length of stay and increased medical expenditure as age increased. Male patients had significantly longer hospital stays and higher medical costs than did females. Additionally, patient's occupation and type of medical insurance exerted significant effects on both length of stay and medical expense.

CONCLUSION

Age significantly affects PD hospitalization costs. Given the prevailing demographic shift toward an aging population, the government's medical insurance burden related to PD will continue to escalate. Meanwhile, high treatment expenses and out-of-pocket rates impose substantial financial burdens on patients, limiting surgical intervention access to a small fraction of patients. Addressing these issues is of utmost importance in order to ensure comprehensive disease management for the majority of individuals affected by PD.