Effects of diverse Types of Toxoplasma gondii on the outcome of Alzheimer's disease in the rat model. (January 2023)

• Record Type: Journal Article
• Authors: Galeh, Tahereh Mikaeili; Ghazvini, Hamed; Mohammadi, Moslem; Sarvi, Shahabeddin; Azizi, Soheil; Asgarian-Omran, Hossein; Hajizadeh, Fatemeh; Daryani, Ahmad
• Is Part Of: Microbial pathogenesis. Volume 174(2023)
• Publication Date: 2023-01
• Subjects: Alzheimer's disease -- Aβ1-42 -- Chronic infection -- Cognitive impairments -- Neuronal death -- Toxoplasma gondii; Pathogenic microorganisms -- Periodicals; Pathology, Molecular -- Periodicals; Communicable Diseases -- microbiology -- Periodicals; Communicable Diseases -- parasitology -- Periodicals; Micro-organismes pathogènes -- Périodiques; Pathologie moléculaire -- Périodiques; Electronic journals; 616.9041
• DOI: 10.1016/j.micpath.2022.105931
• Languages: English
• ISSNs: 0882-4010

Abstract

Abstract: Toxoplasma gondii has lifelong persistence in the brain and its cysts can affect gene expression and change diverse biological functions of neurons. Many studies indicated T. gondii infection as a risk factor for the development of behavioral changes and neurodegenerative diseases such as Alzheimer's disease (AD), although the etiopathogenetic link between them has not been exactly elucidated. The current study aimed to examine the effects of chronic toxoplasmosis infection with Types I, II, and III strains (RH, PRU, and VEG) alone and in combination on cognitive impairments and neuronal death in the Aβ1-42-induced rat model of Alzheimer's disease. In the chronic toxoplasmosis phase, Alzheimer's induction was conducted by injecting Aβ1-42 oligomers into the rat brain hippocampus. Behavioral tests were conducted 10 days after the AD induction. Real-time PCR was performed to evaluate T. gondii parasite burden by amplification of the B1 gene. Cytokines IL-1β, TNF-α, and IL-10 were assayed in brain tissue supernatant using ELISA. Also, histopathological examinations were conducted to calculate inflammatory changes and neuronal death in the brain. Our findings showed that chronic toxoplasmosis infection with PRU reduces cognitive disorders, while the RH strain of T. gondii plays a destructive role and aggravates cognitive impairments in AD. Also, infection with a combination of PRU and VEG strains significantly improved spatial learning and memory impairments in Alzheimer's rat model. Histopathological findings also confirmed the results of behavioral tests, so that in AβPRU and AβPRU + VEG groups, neuronal death and infiltration of inflammatory cells were negligible and significantly less than in Alzheimer's and AβRH groups. Our findings indicate that chronic toxoplasmosis infection with PRU strain alone, also in combination with VEG strain can significantly improve cognitive disorders in AD rats, while RH strain plays a destructive role in AD pathogenesis. Highlights: Chronic toxoplasmosis infection with PRU strain reduces cognitive impairments in the rat model of Alzheimer's disease. Chronic toxoplasmosis infection with RH strain aggravates cognitive disorders in the rat model of Alzheimer's disease. Chronic toxoplasmosis infection with a combination of PRU and VEG strains improved cognitive impairments in the rat model of Alzheimer's disease.