mycophenolic-acid and Toxoplasmosis

Fertility in women with kidney failure is restored by transplantation. It requires careful planning and is only advisable in women with good kidney function, controlled blood pressure, and general good health. Immunosuppressive drugs carry risks for the fetus, but the risks of prednisone, azathioprine, cyclosporine, and tacrolimus are surprisingly low. Mycophenolate is teratogenic. The success rate for pregnancy in kidney transplant recipients is lower than in the general population with 70% to 80% of pregnancies resulting in surviving infants. Prematurity, intrauterine growth restriction, and preeclampsia are all increased. Complications are higher and outcomes are worse for women with serum creatinine levels over 1.3 mg/dL. Ten to 15% of women have a temporary or permanent decline in kidney function, particularly if prepregnancy creatinine is high. Transplant-related infections can be serious for the mother and fetus. A multidisciplinary team should coordinate care.

Topics: Anemia; Azathioprine; Cyclosporine; Cytomegalovirus Infections; Female; Herpes Simplex; Humans; Immunosuppression Therapy; Immunosuppressive Agents; Kidney Failure, Chronic; Kidney Transplantation; Mycophenolic Acid; Preconception Care; Prednisone; Pregnancy; Pregnancy Complications; Tacrolimus; Toxoplasmosis; Urinary Tract Infections

The biochemical and structural changes that occur during the conversion of Toxoplasma gondii tachyzoites to bradyzoites and the formation of tissue cyst are not well understood. Maintaining cells infected with T. gondii type II and III strains under stress conditions induces the tachyzoite-bradyzoite in vitro differentiation, along with the formation of cyst-like structures. However, due to the long exposure to such conditions required to induce the differentiation, the severe damages in the host cell and the low encystation frequency, it has been difficult to dissect in more detail these processes. Here, we successfully induced the in vitro formation of Toxoplasma cysts-like structures from tachyzoites of the type I RH strain by treating with mycophenolic acid, an inhibitor of the inosine monophosphate dehydrogenase. Mycophenolic acid is a drug widely used for HXGPRT positive selection of Toxoplasma mutant strains along with xanthine incubation in the culture medium; under such conditions, formation of tissue cysts has not been reported. We show that the exposure of extracellular tachyzoites to mycophenolic acid in absence of xanthine, followed by host cell invasion, triggered their differentiation into cyst-like structures. The differential expression of CST1, BAG1, and SAG1 molecules, as well as the structural modifications of infected cells, was characterized during the formation of cyst-like structures in vitro. These findings will allow the characterization of signaling pathways involved in tachyzoite to bradyzoite conversion and formation of tissue cysts.

Topics: Cell Differentiation; Humans; Life Cycle Stages; Mycophenolic Acid; Protozoan Proteins; Signal Transduction; Toxoplasma; Toxoplasmosis

Toxoplasma gondii (T. gondii) is an apicomplexan parasite that can cause eye disease, brain disease, and death, especially in congenitally infected and immune-compromised people. Novel medicines effective against both active and latent forms of the parasite are greatly needed. The current study focused on the discovery of such medicines by exploring a family of potential inhibitors whose antiapicomplexan activity has not been previously reported. Initial screening efforts revealed that niclosamide, a drug approved for anthelmintic use, possessed promising activity in vitro against T. gondii. This observation inspired the evaluation of the activity of a series of salicylanilides and derivatives. Several inhibitors with activities in the nanomolar range with no appreciable in vitro toxicity to human cells were identified. An initial structure-activity relationship was explored. Four compounds were selected for evaluation in an in vivo model of infection, and two derivatives with potentially enhanced pharmacological parameters demonstrated the best activity profiles.

Topics: Animals; Antimalarials; Antiparasitic Agents; Cells, Cultured; Drug Resistance; Female; Fibroblasts; Humans; Mice; Mice, Transgenic; Plasmodium falciparum; Salicylanilides; Structure-Activity Relationship; Toxoplasma; Toxoplasmosis