Evaluation of polymorphic variants in apoptotic genes and their role in susceptibility and clinical progression to systemic lupus erythematosus.

Background Systemic lupus erythematosus (SLE) is an autoimmune disease marked by the disruption of the immune homeostasis. Patients exhibit a wide range of clinical manifestations, and environmental and genetic factors are involved in SLE pathogenesis. Evidence suggests that abnormalities in the cellular and molecular events that coordinate apoptosis may favour the generation of autoantigens involved in autoimmunity. In this way, the apoptotic deregulation may be affected by polymorphic variants in apoptotic-related genes. Methods We analyzed FAS, FASL, BCL-2 and BAX polymorphisms in order to correlate to SLE susceptibility and clinical features. A total of 427 SLE patients from the Hospital de Clínicas de Porto Alegre and 543 controls from southern Brazil were evaluated. Results We observed higher frequencies of the FASL -844CC genotype and -844C allele, as well as of the FASL-844C/IVS2nt-124A haplotype in African-derived SLE patients when compared to controls ( P < 0.001). FASL -844C, which is related to high FasL expression, could contribute to increased apoptosis and to the breakdown of immunological tolerance, favouring autoantibody production and inflammation. On the other hand, the BAX -248GA genotype and the -248A allele , related to low protein expression, were observed as a protective factor against SLE in this same population. The rate of apoptosis and cell death was evaluated in peripheral lymphocytes, and SLE patients presented a higher percentage of dead lymphocytes (CD3+Annexin V+ 7-AAD+) compared to the control group. Conclusion Our data support a role for apoptosis in SLE susceptibility.

Vitrification of Rattus norvegicus immature cumulus-oocyte complexes using hyaluronic acid.

The aim of this study was to assess in vitro meiosis resumption and nuclear maturation of Rattus norvegicus oocytes after vitrification with different cryoprotective solutions. Cumulus-oocyte complexes (COCs) were exposed to an equilibration solution for 4 min placed in cryoprotective solutions for 1 min and vitrified in open pulled straws. Cryoprotective solutions were prepared with 15% ethylene glycol + 15% dimethyl sulfoxide + 0.5 M sucrose and different supplements, to form the following groups: G1, 20% fetal bovine serum in modified phosphate-buffered saline (mPBS); G2, 0.4% bovine serum albumine in mPBS; G3, 1% hyaluronic acid in mPBS; and G4, 0.4% polyvinyl alcohol in mPBS. Seven days after vitrification, the COCs from G1 to G4 were warmed and in vitro matured for 30 h along with the control group. Hoechst staining was performed to assess meiosis resumption and nuclear maturation rates. Control group showed higher meiosis resumption (77.88%) and nuclear maturation rates (55.75%) compared to all vitrified groups. Among the vitrified COCs, G3 showed the highest meiosis resumption and nuclear maturation rates (G1, 26.5 and 15.38%; G2, 22.12 and 11.54%; G3, 34.55 and 20%; G4, 20.17 and 9.24%). Supplementation of the vitrification solution with 1% hyaluronic acid provided better results, compared to the other supplements. Hyaluronic acid can be useful to vitrify rat COCs associated with other cryoprotectant agents.