The influence of exposure to Toxoplasma Gondii on host lipid metabolism

Cloning, expression, and purification of an α-carbonic anhydrase from Toxoplasma gondii to unveil its kinetic parameters and anion inhibition profile

Toxoplasmosis, induced by the intracellular parasite Toxoplasma gondii, holds considerable implications for global health. While treatment options primarily focusing on folate pathway enzymes have notable limitations, current research endeavours concentrate on pinpointing specific metabolic pathways vital for parasite survival. Carbonic anhydrases (CAs, EC 4.2.1.1) have emerged as potential drug targets due to their role in fundamental reactions critical for various protozoan metabolic processes. Within T. gondii, the Carbonic Anhydrase-Related Protein (TgCA_RP) plays a pivotal role in rhoptry biogenesis. Notably, α-CA (TcCA) from another protozoan, Trypanosoma cruzi, exhibited considerable susceptibility to classical CA inhibitors (CAIs) such as anions, sulphonamides, thiols, and hydroxamates. Here, the recombinant DNA technology was employed to synthesise and clone the identified gene in the T. gondii genome, which encodes an α-CA protein (Tg_CA), with the purpose of heterologously overexpressing its corresponding protein. Tg_CA kinetic constants were determined, and its inhibition patterns explored with inorganic metal-complexing compounds, which are relevant for rational compound design. The significance of this study lies in the potential development of innovative therapeutic strategies that disrupt the vital metabolic pathways crucial for T. gondii survival and virulence. This research may lead to the development of targeted treatments, offering new approaches to manage toxoplasmosis.

Toxoplasma gondii infection is associated with schizophrenia from the perspectives of seroepidemiology and serum metabolomics in Hunan Province, China

Toxoplasma gondii (T.gondii) can influence the host's neurotransmission, central immune responses, and brain structure, potentially impacting the onset and development of various psychiatric disorders such as schizophrenia. We employed Electrochemiluminescence Immunoassay (ECLIA) to measure anti-Toxoplasma antibodies in 451 schizophrenic patients and 478 individuals from the general population in Hunan, China. The incidence rate of T.gondii infection in schizophrenic patients (8.87 %) was higher than that in the general population (3.77 %). A significant difference was observed among females, but not in males. Age-stratified analysis revealed significant differences in the 21-40 and 41-60 age groups. The two populations had no significant difference in the antibody titer for T. gondii infection. Additionally, the profile of circulating metabolites in the serum of schizophrenic patients with or without T. gondii infection was examined using non-targeted metabolomics assay. A total of 68 metabolites were differentially expressed between Toxoplasma-positive and Toxoplasma-negative groups, potentially mediating the connection between T. gondii infection and schizophrenia. Our research suggests that schizophrenic patients are susceptible to T. gondii infection with distinct metabolic program.

Toxoplasma gondii IgG serointensity and cognitive function in bipolar disorder

BACKGROUND

Alongside affective episodes, cognitive dysfunction is a core symptom of bipolar disorder. The intracellular parasite T. gondii has been positively associated with both, the diagnosis of bipolar disorder and poorer cognitive performance, across diagnostic boundaries. This study aims to investigate the association between T. gondii seropositivity, serointensity, and cognitive function in an euthymic sample of bipolar disorder.

METHODS

A total of 76 participants with bipolar disorder in remission were tested for T. gondii-specific IgG and IgM antibodies and for cognitive performance using neuropsychological test battery. Cognitive parameters were categorized into three cognitive domains (attention and processing speed, verbal memory, and executive function). Statistical analysis of associations between continuous indicators of cognitive function as dependent variables in relationship to T. gondii, included multivariate analyses of co-variance for seropositivity, and partial correlations with IgG serointensity in IgG seropositives. All analyses were controlled for age and premorbid IQ.

RESULTS

In seropositives (n = 27), verbal memory showed significant inverse partial correlations with IgG antibody levels (short delay free recall (r=-0.539, p = 0.005), long delay free recall (r=-0.423, p = 0.035), and immediate recall sum trial 1-5 (r=-0.399, p = 0.048)). Cognitive function did not differ between IgG seropositive and seronegative individuals in any of the cognitive domains (F (3,70) = 0.327, p = 0.806, n = 76). IgM positives (n = 7) were too few to be analyzed.

CONCLUSIONS

This investigation is the first to show an association between T. gondii IgG serointensity and memory function in a well-diagnosed bipolar disorder sample. It adds to the existing literature on associations between latent T. gondii infection and cognition in bipolar disorder, while further research is needed to confirm and expand our findings, eliminate potential sources of bias, and establish cause-effect relationships.

The intersection of host in vivo metabolism and immune responses to infection with kinetoplastid and apicomplexan parasites

SUMMARYProtozoan parasite infection dramatically alters host metabolism, driven by immunological demand and parasite manipulation strategies. Immunometabolic checkpoints are often exploited by kinetoplastid and protozoan parasites to establish chronic infection, which can significantly impair host metabolic homeostasis. The recent growth of tools to analyze metabolism is expanding our understanding of these questions. Here, we review and contrast host metabolic alterations that occur in vivo during infection with Leishmania, trypanosomes, Toxoplasma, Plasmodium, and Cryptosporidium. Although genetically divergent, there are commonalities among these pathogens in terms of metabolic needs, induction of the type I immune responses required for clearance, and the potential for sustained host metabolic dysbiosis. Comparing these pathogens provides an opportunity to explore how transmission strategy, nutritional demand, and host cell and tissue tropism drive similarities and unique aspects in host response and infection outcome and to design new strategies to treat disease.

Causal role of lipid metabolism in pulmonary alveolar proteinosis: an observational and mendelian randomisation study

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare interstitial lung disease characterised by the accumulation of lipoprotein material in the alveoli. Although dyslipidaemia is a prominet feature, the causal effect of lipid traits on PAP remains unclear. This study aimed to explore the role of lipid traits in PAP and evaluate the potential of lipid-lowering drug targets in PAP.

METHODS

Clinical outcomes, lipid profiles and lung function tests were analysed in a clinical cohort of diagnosed PAP patients and propensity score-matched healthy controls. Genome-wide association study data on PAP, lipid metabolism, blood cells and variants of genes encoding potential lipid-lowering drug targets were obtained for Mendelian randomisation (MR) and mediation analyses.

FINDINGS

Observational results showed that higher levels of total cholesterol (TC), triglycerides and low-density lipoprotein (LDL) were associated with increased risks of PAP. Higher levels of TC and LDL were also associated with worse PAP severity. In MR analysis, elevated LDL was associated with an increased risk of PAP (OR: 4.32, 95% CI: 1.63 to 11.61, p=0.018). Elevated monocytes were associated with a lower risk of PAP (OR 0.34, 95% CI: 0.18 to 0.66, p=0.002) and mediated the risk impact of LDL on PAP. Genetic mimicry of PCSK9 inhibition was associated with a reduced risk of PAP (OR 0.03, p=0.007).

INTERPRETATION

Our results support the crucial role of lipid and metabolism-related traits in PAP risk, emphasising the monocyte-mediated, causal effect of elevated LDL in PAP genetics. PCSK9 mediates the development of PAP by raising LDL. These finding provide evidence for lipid-related mechanisms and promising lipid-lowering drug target for PAP.

Trypanosoma cruzi modulates lipid metabolism and highjacks phospholipids from the midgut of Rhodnius prolixus

Chagas disease is potentially life-threatening and caused by the protozoan parasite Trypanosoma cruzi. The parasite cannot synthesize some lipids and depends on the uptake of these lipids from its vertebrate and invertebrate hosts. To achieve this, T. cruzi may need to modify the physiology of the insect host for its own benefit. In this study, we investigated the interaction of T. cruzi (Y strain) with its insect vector Rhodnius prolixus and how it manipulates the vector lipid metabolism. We observed a physiological change in lipid flux in of infected insects. In the fat body of infected insects, triacylglycerol levels decreased by 80.6% and lipid storage droplet-1(LSD-1) mRNA levels were lower, when compared to controls. Lipid sequestration by infected midguts led to increased levels of 5' AMP-activated protein kinase (AMPK) phosphorylation and activation in the fat body, inhibiting the synthesis of fatty acids and stimulating their oxidation. This led to reduced lipid levels in the fat body of infected insets, despite the fact that T. cruzi does not colonize this tissue. There was a 3-fold increase, in lipid uptake and synthesis in the midgut of infected insects. Finally, our results suggest that the parasite modifies the lipid flux and metabolism of its vector R. prolixus through the increase in lipid delivery from the fat body to midgut that are then scavenge by T cruzi.

LDL receptor and pathogen processes: Functions beyond normal lipids

Although the role of the LDL receptor concerning lipids is well known, its role in various viral and parasitic infections, and in regulating the inflammatory response is poorly understood. Several infectious agents use the LDL receptor as a port of entry, and others depend on it for their cycle of infection. In this review, we focus on the discovery, structure, and normal function of the LDL receptor, as well as its role in a selection of infections. The LDL receptor plays an important role in certain infections and is a potential target for treatment deserving further research.

Effects of Toxoplasma gondii infection and schizophrenia comorbidity on serum lipid profile: A population retrospective study from Eastern China

INTRODUCTION

Toxoplasma gondii (T. gondii), a parasitic protozoa that is associated with various psychiatric disorders. Both T. gondii infection and disturbed host's lipid profile are common in schizophrenia patients. However, the underlying pathophysiological mechanisms remain speculative. Also, the characteristics of serum lipid levels in schizophrenia patients comorbid with T. gondii infection are not clear. Therefore, it is necessary to explore the influence of chronic T. gondii infection on the characteristic physiological indexes of schizophrenia patients so as to provide some insights into finding target therapeutic drugs.

METHODS

In this study, the effect of chronic T. gondii infection on serum lipid profile was retrospectively analysed in 1719 schizophrenic patients and 1552 healthy subjects from Eastern China.

RESULTS

The overall prevalence of Immunoglobulin G (IgG) antibodies against T. gondii (17.98%) in schizophrenia patients was significantly higher than healthy controls (7.35%, χ2 = 81.831, P = 0.000). Compared to T. gondii IgG-seronegative schizophrenia patients, IgG-seropositive group had higher high-density lipoprotein (HDL) (P = 0.000) and triglycerides (TG) (P = 0.000) levels, while total cholesterol (TC) (P = 0.000) levels showed an opposite tendency in IgG-seropositive cases. We also found significant correlation between T. gondii seropositivity and increased TG (P = 0.000) and TC levels (P = 0.000) in schizophrenia patients. Binary regression analysis also showed that decreased TC level was more common among schizophrenia patients with T. gondii seropositivity compared to seronegative subjects (OR = 0.617, 95%CI = 0.509-0.749, P = 0.000).

CONCLUSION

Patients with chronic T. gondii infection and comorbid schizophrenia had higher HDL and TG levels, while cholesterol levels showed an opposite trend. To the best of our knowledge, this is the first report focus on the host's lipid profile of chronic T. gondii infection and comorbid schizophrenia patients.