Structural, Functional, and Metabolic Alterations in Human Cerebrovascular Endothelial Cells during Toxoplasma gondii Infection and Amelioration by Verapamil In Vitro

Abstract

Toxoplasma gondii (T. gondii), the causative agent of toxoplasmosis, is a frequent cause of brain infection. Despite its known ability to invade the brain, there is still a dire need to better understand the mechanisms by which this parasite interacts with and crosses the blood–brain barrier (BBB). The present study revealed structural and functional changes associated with infection and replication of T. gondii within human brain microvascular endothelial cells (BMECs) in vitro. T. gondii proliferated within the BMECs and disrupted the integrity of the cerebrovascular barrier through diminishing the cellular viability, disruption of the intercellular junctions and increasing permeability of the BMEC monolayer, as well as altering lipid homeostasis. Proton nuclear magnetic resonance (1H NMR)-based metabolomics combined with multivariate data analysis revealed profiles that can be attributed to infection and variations in the amounts of certain metabolites (e.g., amino acids, fatty acids) in the extracts of infected compared to control cells. Notably, treatment with the Ca2+ channel blocker verapamil rescued BMEC barrier integrity and restricted intracellular replication of the tachyzoites regardless of the time of treatment application (i.e., prior to infection, early- and late-infection). This study provides new insights into the structural and functional changes that accompany T. gondii infection of the BMECs, and sheds light upon the ability of verapamil to inhibit the parasite proliferation and to ameliorate the adverse effects caused by T. gondii infection.

ROP18-Mediated Transcriptional Reprogramming of HEK293T Cell Reveals New Roles of ROP18 in the Interplay Between Toxoplasma gondii and the Host Cell

“…Recent studies show that T. gondii infection can induce significant structural, functional and metabolic changes in the brain microvascular endotehlial cells (Al-Sandaqchi et al, 2018;Hu et al, 2018;Ma et al, 2019;Al-Sandaqchi et al, 2020;Harun et al, 2020a;Harun et al, 2020b) and can change the neuron subpopulations (Odorizzi et al, 2010). However, the exact mechanisms of behavioral abnormalities and change in the subpopulations of neurons induced by T. gondii infection remains to be clearly defined.…”

Illuminating Host-Parasite Interaction at the Cellular and Subcellular Levels with Infrared Microspectroscopy

“…Alterations in the lipid and protein contents of hBMECs have been previously detected using proton nuclear magnetic resonance-based metabolomic analysis [ 7 , 9 ]. In addition, changes in the abundance of lipids (e.g., glycerophospholipid) and amino acid (phenylalanine, retinol, and tryptophan) were detected in mouse cerebellum during T. gondii infection by using ultra performance liquid chromatography-tandem mass spectrometry-based metabolomics [ 28 ].…”

“…For example, mass-spectrometry-coupled with liquid chromatography has been used to characterize the impact of T. gondii infection on the metabolism of cerebral cortex [ 5 ], cerebellum [ 5 ] and the whole brain in mice [ 6 ]. Nuclear magnetic resonance (NMR) was used to study the metabolic changes in human cerebrovascular endothelial cells during T. gondii infection [ 7 ]. Raman microspectroscopy has been used to characterize the spatio-temporal molecular changes in human retinal cells infected by T. gondii tachyzoites [ 4 ].…”

Effect of verapamil on bone mass, microstructure and mechanical properties in type 2 diabetes mellitus rats

“…First approved for medical use in 1981, it is commonly used in the treatment of hypertension, myocardial disease, inflammation, cerebrovascular disease, pulmonary hypertension and other diseases. Some studies have pointed out that the combination of tradopril and verapamil can treat hypertension in patients with type 2 diabetes [ 21 ]; verapamil can improve the structure, function and metabolism of human brain vascular endothelial cells [ 22 , 23 ]; in addition, the activities of calpain-1 and matrix metalloproteinase-2 are reduced, and the cardiac remodeling induced by hypertension in rats is improved after verapamil treatment [ 24 ]; verapamil can also reduce inflammation and joint destruction in the arthritis model of 10 week-old male DBA1/J mice [ 25 ]. Some scholars have also studied the glucose metabolism of verapamil, which shows that verapamil can reduce blood glucose of patients with diabetes [ 26 ]; oral administration of verapamil for 12 months can promote beta cell function, reduce insulin demand and the occurrence of hypoglycemia in adult patients with T1DM [ 27 ]; compared with other calcium channel blockers, oral administration of verapamil in patients with no history of diabetes can reduce the incidence of T2DM, especially in elderly patients [ 28 ].…”