Investigation of suspected deficient Fas-mediated apoptosis in a father and son

Flow Cytometric Evaluation of Primary Immunodeficiencies

Primary immunodeficiency diseases are genetic disorders that mostly cause susceptibility to infections and are sometimes associated with autoimmune and malignant diseases. For early detection and management of these diseases, flow cytometric procedures allow an encompassing assessment of cellular phenotypes and cellular functions. State-of-the art cytometry is based today on 8- to 10-color staining and includes an assessment of lineage maturation and functional markers.

Effects of apigenin on the expression levels of B-cell lymphoma-2, Fas and Fas ligand in renal ischemia-reperfusion injury in rats

The aim of the present study was to investigate the effect and possible mechanism of apigenin on renal ischemia-reperfusion (I/R) injury in rats, as well as in in vitro experiments. In total, 36 rats were subjected to 45 min of renal ischemia, with or without treatment prior to ischemia with different concentrations of apigenin (2, 10 and 50 mg/kg) administered intravenously. All rats were sacrificed at 24 h after I/R injury. The serum creatinine (Cr) and blood urea nitrogen (BUN) levels were analyzed, and histological examination was conducted. In addition, the expression levels of B-cell lymphoma 2 (Bcl-2) and Fas/Fas ligand (FasL) were detected by immunohistochemistry, reverse transcription-quantitative polymerase chain reaction and western blot analysis. For in vitro experiments, the NRK-52E cell line was employed. The viability, apoptosis and expression levels of Fas, FasL and Bcl-2 were examined in the culture of NRK-52E cells following the I/R. The results indicated that apigenin significantly decreased the levels of serum Cr and BUN induced by renal I/R, demonstrating an improvement in renal function. The histological evidence of renal damage associated with I/R was also mitigated by apigenin in vivo. Furthermore, apigenin increased the cell viability and decreased cell apoptosis in the culture of NRK52E after I/R in vitro. Compared with the I/R group, the expression of Bcl-2 was upregulated and the expression levels of Fas and FasL were downregulated by apigenin at the mRNA and protein levels in vivo and in vitro. In conclusion, apigenin appeared to increase the expression of Bcl-2 and reduce Fas/FasL expression in renal I/R injury, providing evident protection against renal I/R injury in rats.

Autoimmune lymphoproliferative syndrome: etiology, diagnosis, and management

Autoimmune lymphoproliferative syndrome (ALPS) is a childhood disorder characterized by chronic, nonmalignant lymphoproliferation and autoimmunity, most commonly involving cells of hematopoietic origin. Mutations of the tumor necrosis factor receptor super family member 6 (TNFRSF6) gene, coding for the apoptosis-inducing protein Fas (Apo-1, CD95) are involved in the physiopathology of the syndrome, although the complete mechanism by which the syndrome is caused has not yet been unraveled. Although the syndrome has a benign nature, life-threatening complications can demand treatment. Treatment schedules, including corticosteroids, low doses of chemotherapy, granulocyte colony stimulating factor, or splenectomy, have varying results. Treatment with the antimalarial drug pyrimethamine/sulfadoxine (25/500mg per tablet) seems to be a new, well tolerated, and efficient approach, although larger studies will have to demonstrate the true value of this drug in patients with ALPS.

Apoptosis: biochemical aspects and clinical implications

Apoptosis and necrosis represent two distinct types of cell death. Apoptosis possesses unique morphologic and biochemical features which distinguish this mechanism of programmed cell death from necrosis. Extrinsic apoptotic cell death is receptor-linked and initiates apoptosis by activating caspase 8. Intrinsic apoptotic cell death is mediated by the release of cytochrome c from mitochondrial and initiates apoptosis by activating caspase 3. Cancer chemotherapy utilizes apoptosis to eliminate tumor cells. Agents which bind to the minor groove of DNA, like camptothecin and Hoechst 33342, inhibit topoisomerase I, RNA polymerase II, DNA polymerase and initiate intrinsic apoptotic cell death. Hoechst 33342-induced apoptosis is associated with disruption of TATA box binding protein/TATA box complexes, replication protein A/single-stranded DNA complexes, topoisomerase I/DNA cleavable complexes and with an increased intracellular concentration of E2F-1 transcription factor and nitric oxide concentration. Nitric oxide and transcription factor activation or respression also regulate the two apoptotic pathways. Some human diseases are associated with excess or deficient rates of apoptosis, and therapeutic strategies to regulate the rate of apoptosis include inhibition or activation of caspases, mRNA antisense to reduce anti-apoptotic factors like Bcl-2 and survivin and recombinant TRAIL to activate pro-apoptotic receptors, DR4 and DR5.