Rapamycin Plays an Anti-Epileptic Role by Restoring Blood-Brain Barrier Dysfunction, Balancing T Cell Subsets and Inhibiting Neuronal Apoptosis.

BACKGROUND: Rapamycin (RAP), as a Mammalian Target of Rapamycin (mTOR) inhibitor, has a certain antiepileptic effect. The blood-brain barrier (BBB), neuroinflammation, lymphocyte immune cells, and neuronal apoptosis play an obligatory role in the course of a seizure. The aim of this study is to probe whether the antiepileptic mechanism of RAP involves the blood-brain barrier, neuroinflammation, lymphocytes, and neuronal apoptosis. METHODS: First, we established a rat epilepsy model by injecting lithium chloride and pilocarpine into the rats (intraperitoneal injection). Then the epileptic rats were treated with different doses of RAP (1 mg/kg.d, 2 mg/kg.d, 4 mg/kg.d). Peripheral blood, brain tissue, and temporal lobe tissue were collected. The levels of blood-brain barrier-related proteins and inflammatory cytokines in the peripheral blood of rats were measured by enzyme-linked immunosorbent assay (ELISA). The effect of RAP on T cell subsets in epileptic rats was analyzed by flow cytometry. The apoptosis of neurons and glial cells in the temporal lobe of rats was analyzed by immunohistochemistry. RESULTS: This study found that RAP reduces the levels of BBB-interrelated proteins (matrix metallopeptidase 9 (MMP-9), MMP-2, tissue inhibitor of metalloproteinases 1 (TIMP-1), TIMP-2) and inflammatory cytokines (interleukin-2 (IL-2), interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α)) in epileptic rats compared to the model group (p < 0.05). RAP increases the level of total T cells (CD3+CD45+) and T helper cells (CD3+CD4+), decreases the level of cytotoxic T lymphocytes (CD3+CD8+), and inhibits the apoptosis of neurons and glial cells in the temporal lobe compared to the model group (p < 0.05). CONCLUSIONS: The antiepileptic mechanism of RAP may be to restore BBB dysfunction, reduce the inflammatory response, balance T cell subsets, and inhibit neuronal and glial cell apoptosis in temporal lobe epilepsy lesions.

Role of immune dysfunction in pathogenesis of type 1 diabetes mellitus in children.

OBJECTIVES: To investigate the function of cytokines, chemokines, and regulatory T cells (Tregs) in the pathogenesis of type 1 diabetes mellitus (T1DM) in children. METHODS: A total of 35 children with T1DM and 30 healthy controls were enrolled in this study. Levels of serum cytokines (IL-1α, IL-6, IL-10, IL-12, and TNF-α) and chemokines (MIP-1α, MIP-1α and MCP-1) were detected by enzyme-linked immunosorbent assay. Peripheral blood mononuclear cells (PBMCs) were isolated and culture supernatant of phytohaemagglutinin (PHA)-stimulated PBMCs was subjected to ELISA for levels of cytokines (IL-1α, IL-6, IL-10, IL-12 and TNF-α) in T1DM and control group. Furthermore, flow cytometry was used to determine the percentage of Tregs in PBMCs of two groups. RESULTS: Levels of serum cytokines including IL-1α, IL-6, IL-10 and TNF-α as well as chemokines, such as MIP-1α and MIP-1α in children with T1DM children were significantly higher than those in healthy controls (P<0.05, respectively). PBMCs with PHA stimulation in T1DM group secreted more IL-1α and TNF-α (P<0.05, respectively), but less IL-10 (P<0.05), as compared with control group. Furthermore, the proportion of CD4(+), CD25(+), Foxp3(+), Tregs in PBMCs isolated from children with T1DM was obviously lower than those in healthy controls (P<0.05). CONCLUSIONS: Immune dysfunction, with upregulation of inflammatory factors such as IL-1α, IL-6, TNF-α and MIP-1α, downregulation of IL-10 and Tregs, plays an important role in the pathogenesis of T1DM in children.