Human α-Synuclein over-expression increases intracellular reactive oxygen species levels and susceptibility to dopamine

alpha-Synuclein is a major component of Lewy bodies found in the brains of patients with Parkinson's disease (PD). Two point mutations in alpha-synuclein (A53T and A30P) are identified in few families with dominantly inherited PD. Yet the mechanism by which this protein is involved in nigral cell death remains poorly understood. Mounting evidence suggests the importance of oxidative stress in the pathogenesis of PD. Here we investigated the effects of wild-type and two mutant forms of alpha-synuclein on intracellular reactive oxygen species (ROS) levels using clonal SH-SY5Y cells engineered to over-express these proteins. All three cell lines, and particularly mutant alpha-synuclein-expressing cells, had increased ROS levels relative to control LacZ-engineered cells. In addition, cell viability was significantly curtailed following the exposure of all three alpha-synuclein-engineered cells to dopamine, but more so with mutant alpha-synuclein. These results suggest that over-expression of alpha-synuclein, and especially its mutant forms, exaggerates the vulnerability of neurons to dopamine-induced cell death through excess intracellular ROS generation. Thus, these findings provide a link between mutations or over-expression of alpha-synuclein and apoptosis of dopaminergic neurons by lowering the threshold of these cells to oxidative damage.     

IFN-beta gene transfer into the central nervous system using bone marrow cells as a delivery system.

The peripheral delivery of interferon-beta (IFN-beta) for the treatment of central nervous system (CNS) diseases is only partially effective because of the blood-brain barrier (BBB). To circumvent this problem, we evaluated the feasibility of genetically altering bone marrow cells ex vivo and using them as vehicles to transfer the IFN-beta cDNA into the mouse CNS. An IFN-beta retroviral expression vector (pLXSN-IFNbeta) was used to stably transfect PA317 cells. The supernatant from these producer cells, which expressed IFN-beta mRNA and protein, were used to infect bone marrow cells. When transplanted into irradiated mice, IFN-beta-engineered marrow cells accessed the CNS and expressed IFN-beta mRNA and protein. Marrow cells transduced with a control neomycin vector entered the brain and expressed the neomycin but not the IFN-beta gene. In the CNS, IFN-beta delivered by marrow cells induced the mRNA expression of 2',5'-oligoadenylate synthetase (2',5'-OAS), indicating biologic activity. Our findings demonstrating that bone marrow cells can serve as a delivery system for IFN-beta cDNA into the CNS could have implications for the treatment of neurologic disorders, such as multiple sclerosis (MS), viral encephalitis, and brain tumors.     

Matrix Metalloproteinases 2 and 9 Polymorphism in Patients With Myeloproliferative Diseases: A STROBE-Compliant Observational Study

Chronic myeloproliferative disorders such as polycythemia vera (PV), essential thrombocytosis (ET), and idiopathic myelofibrosis arise from clonal proliferation of neoplastic stem cells in the bone marrow. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that have potential to degrade all types of extracellular matrix (ECM) and also play a role in remodeling of the ECM. It is known that MMPs play a role in bone marrow remodeling.The primary goal of our study is to explore the relationship between chronic myeloproliferative diseases and some of MMP gene polymorphisms. The demonstration of a relationship will help to understand whether these polymorphisms may be a potential early diagnosis marker of the diseases.Patients were selected from outpatient clinics of Turgut Ozal University Hospital, Ankara, Turkey, between December 2010 and May 2011. Twenty-eight patients that previously diagnosed and followed-up with PV, 17 with secondary polycythemia (SP), and 12 with ET were enrolled in the study, along with a control group of 22 healthy people.DNA was isolated from peripheral blood. Using polymerase chain reaction–restriction fragment length polymorphism method, MMP2 and MMP9 gene polymorphisms were analyzed with agarose gel electrophoresis. There was a statistically significant difference between the study groups and the control group in terms of Gln279Arg polymorphisms rates of MMP9. The highest MMP9 Gln279Arg polymorphism rate was observed in the ET group. But nobody from the control group had polymorphic MMP9. There was no statistically significant difference between the groups in terms of MMP2-735 C > T polymorphism rates.In conclusion, MMP9 gene Gln279Arg polymorphism was associated with ET, SP, and PV diseases. Hence, we believe that these gene polymorphisms may play a role in the mechanism of bone marrow fibrosis and may be a factor that increases the risk of thrombosis. Illumination of the molecular basis of the relationship between MMP-thrombosis and MMP-fibrosis provides a better understanding of the pathophysiology of PV and ET diseases and will allow new approaches to diagnosis and treatment.     

Effect of pentylenetetrazole and sound stimulation induced single and repeated convulsive seizures on the MDA, GSH and NO levels, and SOD activities in rat liver and kidney tissues

Objectives

The aim of our study was to evaluate the activity of superoxide dismutase (SOD) and the levels of glutathione (GSH), malondialdehyde (MDA), and nitric oxide (NO) in liver and kidney tissues in a rat model of convulsive seizure induced by single and repeated doses of pentylenetetrazole (PTZ) and sound stimulation with key ringing.

Materials and methods

Male Wistar adult rats (n = 48), were used in the experiment. The animals were divided into six groups: (1) Single Seizure Control Group (SS-Control; n = 8), (2) Repeated Seizures Control Group (RS-Control; n = 8), (3) PTZ induced Single Seizure Group (SS-PTZ Group; n = 8), (4) PTZ induced Repeated Seizures Group (RS- PTZ Group; n = 8), (5) Key-Ringing Induced Single Seizure Group (SS-KEY Group; n = 8), (6) Key-Ringing Induced Repeated Seizures Group (RS-KEY Group; n = 8). Following injections rats were observed for seizure activity for 30 min. Animals were sacrificed 24 h after induced seizure (single or last seizure) or saline administration. MDA, NO, GSH levels and SOD activities were determined in liver and kidney tissues.

Results

There was no significant difference between SS-Control and RS-Control groups, SS-PTZ and SS-KEY groups, and RS-PTZ and RS-KEY groups (p > 0.05) in none of the examined 4 parameters in liver and kidney tissues.The liver and kidney levels of MDA and NO in SS-PTZ group were found to be significantly higher than the SS-Control group (p < 0.05). In SS-KEY group, the liver and kidney levels of MDA and NO were found to be significantly higher and GSH levels were significantly lower than the SS-Control group (p < 0.05).While liver and kidney levels of MDA in RS-PTZ group and RS-KEY group were found to be significantly higher than the RS-Control group (p < 0.05), liver and kidney GSH levels were significantly lower (p < 0.05). The liver levels of NO in RS-PTZ group and RS-KEY group were found to be significantly higher than the RS-Control group (p < 0.05). Kidney SOD activities in RS-PTZ group and RS-KEY group were found to be significantly lower than the RS-Control group (p < 0.05).When RS-PTZ group is compared with the SS-PTZ group, the liver SOD activity and kidney NO level were found to be significantly lower in the RS-PTZ group (p < 0.05).While the liver NO level and GSH level in RS-KEY group were significantly higher than the SS-KEY group, SOD activity was significantly lower in the RS-KEY group (p < 0.05). When RS-KEY group was compared with SS-KEY group, the kidney NO level and SOD activity were found to be significantly lower in the RS-KEY group (p < 0.05).

Conclusion

In conclusion, key-ringing or PTZ induced single and repeated seizures result in increased oxidative damage and lipid peroxidation, and decreased antioxidant defense mechanisms.     

Turkish adolescents' knowledge on and attitude toward emergency contraception

ObjectiveAdolescents tend to be at risk for unwanted pregnancies, so detecting their level of knowledge on emergency contraception and providing them information is important to prevent such pregnancies. Hence, in two faculties at Gazi University, this study aimed to detect freshman students' level and need of knowledge on emergency contraception and to evaluate their attitude towards emergency contraception.Materials and MethodsThe study was performed with freshman students of the Occupational Education Faculty and the Technical Education Faculty. A questionnaire including questions about demographic properties, obstetrical history, status of contraceptive use, level of knowledge and opinions on emergency contraception was administered to the students. Data was analyzed statistically with the computer program EPI Info 6.0.ResultsA total number of 385 adolescents were included in the studys; 157 of whom were males (40.8%) and 228 of whom were females (59.2%). To the question “is there any way to prevent a possible pregnancy after an unprotected sexual intercourse?”, 166 students replied “yes” (50.5%), 39 “no” (11.9%) and 124 “I do not know” (37.7%). Of 166 students replying “yes,” 114 (68.7%) listed a possible contraceptive method. The mostly cited method was “morning after pills” (n = 62; 54.4%), followed by curettage (n = 15; 13.2%). Among all students, 158 (49.8%) informed us that they were aware of the presence of “morning after pills” whereas 159 (50.2%) claimed they were not. Eighty-six male students (70.5%) and 115 female students (72%) emphasized that they would use emergency contraception upon necessity.ConclusionHalf of the participants were familiar with various options to prevent pregnancy after an unprotected sexual intercourse episode, but they lacked specific knowledge about possible methods and ways to use them. Thus, it is essential that information about emergency contraception be included in adolescents' educational programs and that adolescents be provided with easily accessible medical services.