Objective: Apoptosis is programmed cell death that occurs by several pathways. Caspase-3 is induced by active caspase-9 via the intrinsic pathway. The aim of this research was to explore the expression of caspase-3 and caspase-9 in schizophrenia patients and healthy samples. Methods: RNA was isolated from the peripheral blood of 39 schizophrenia patients’ and healthy samples. After cDNA synthesis, real time PCR (RT-PCR) was used to analyse caspase-3 and caspase-9 gene expression. The severity of psychopathological symptoms of schizophrenia was evaluated using the Positive and Negative Symptoms Scale for schizophrenia (PANSS) and Clinical Global Impressions (CGI). Results: The expression of caspase-3 and caspase-9 genes was higher in schizophrenia patients than in healthy samples (p = 0.012, p = 0.002, respectively). The increase in caspase-3 gene expression was significant with being male, smoking and with a duration of less than 6 years (p = 0.047, p = 0.049, p = 0.034, respectively). On the other hand, the increase in caspase-9 gene expression was significant in patients who is smoke, have children, and are under 33 years old (p = 0.040, p = 0.043, p = 0.045, respectively). A significant positive correlation was detected between the caspase-3 and caspase-9 gene expression (r = 0.3218, p = 0.049). Conclusion Our findings indicate that caspase-3 and caspase-9 gene expression may activate cell death mechanisms by intrinsic apoptotic genes. Furthermore, caspase-3 and caspase-9 may play essential roles in different ways in schizophrenia. Hence there is a need to further study the apoptotic mechanism with expanded patient populations.

Objective: Schizophrenia is a serious mental disorder. Mutations in mitochondrial genes can change energy metabolism. Telomere is a tandem sequence at the end of chromosomes. Shorter telomere length has been shown in schizophrenia. The aim of this study was to determine the relationship between ATPase6 gene mutations and telomere length in schizophrenia patients. Methods: Blood samples of 34 patients and 34 healthy controls were used. In this study conventional PCR, Sanger sequencing technic and real-time PCR were utilized. Results: Five different mutations (A8860G, A8836, G8697A, C8676T, and A8701G) in the ATPase6 gene were identified in schizophrenia patients. The most seen mutation was A8860G (94%). Telomere length analysis indicated the relation of ATPase6 gene mutations and telomere length variations (p = 0.001). Patients carrying the A8860G mutation had shorter telomere lengths than patients carrying other mutations. Comparing telomere length between schizophrenia patients and healthy controls revealed that the mean telomere length of schizophrenia patients was shorter than healthy controls (p = 0.006). The demographic analysis demonstrated a significant relationship between marital status and telomere length (p = 0.011). Besides that, the duration of the illness is another factor that impacts telomere length (p = 0.044). There is no significant relation between telomere length and other clinical and demographic characteristics including education status, age, gender, etc. Conclusion In conclusion, telomere length and ATPase6 gene mutations have a significant relation. Studies with larger patient populations and investigation of other mitochondrial gene mutations will make the clearer link between telomere length and mitochondrial mutations.