نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری فیزیولوژی ورزشی، دانشکدۀ تربیت بدنی و علوم ورزشی، دانشگاه تبریز، تبریز، ایران
2 گروه فیزیولوژی ورزشی، دانشکده تربیت بدنی و علوم ورزشی، دانشگاه تبریز، تبریز، ایران
3 گروه فیزیولوژی ورزشی، دانشکدۀ تربیت بدنی و علوم ورزشی، دانشگاه تبریز، تبریز، ایران
4 4. دانشجوی کارشناسی ارشد فیزیولوژی ورزشی، دانشکدۀ تربیت بدنی و علوم ورزشی، دانشگاه تبریز، تبریز، ایران
5 دانشیار بافت شناسی مقایسه‌ای، گروه علوم پایه، دانشکده دامپزشکی، دانشگاه تبریز، تبریز، ایران.
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Extended Abstract
Background and Aim: In recent years, type II diabetes (T2DM) has emerged as a chronic metabolic disease with increasing prevalence and is recognized one of the primary causes of cardiovascular complications. In this condition, elevated levels of microRNAs such as miR-34a and the p53 protein are associated with pancreatic β-cell apoptosis, cardiac dysfunction, and the progression of diabetic cardiomyopathy. miR-34a, as a key downstream target of p53, plays a critical role in regulating gene expression and modulating both inflammatory and oxidative stress responses.
Evidence indicates that moderate-to-high-intensity aerobic training can reduce the expression of miR-34a and p53, thereby exerting cardioprotective effects in diabetic patients. Several animal studies have also demonstrated reductions in these markers following exercise training. As a result , regular physical activity may serve as an effective non-pharmacological strategy to improve cardiac outcomes and reduce metabolic complications in T2DM. Given the involvement of microRNAs in the pathophysiology of various diseases, including diabetes, and the therapeutic value of aerobic training in T2DM as well as the existing inconsistencies in studies on the effects of physical activity on microRNAs, the present study aims to investigate the effect of aerobic training on the expression of p53 and miR-34a genes in the heart tissue of T2DM rats.
Materials and Methods: This experimental laboratory study employed a one-factor post-test design, was conducted with the approval of the ethics committee of the university of Tabriz (ID: IR.TABRIZU.REC.1402.022). Twenty male Wistar rats aged six to eight weeks, with an average weight of 239±28 grams, were obtained from the animal laboratory of Tabriz university. After a two-week acclimation period under laboratory conditions, the rats were randomly divided into four groups: healthy control, healthy training (HT), diabetic control (DC), and diabetic training (DT).
T2DM was induced using a combination of a high-fat diet (HFD) and intraperitoneal injection of Streptozotocin at a dose of 35 mg/kg. Rats with blood glucose levels exceeding 300 mg/dl were considered diabetic.
The aerobic training protocol consisted of treadmill running for eight weeks, five days per week, with gradual increments in speed from 5–10 m/min to 18–24 m/min and duration from 10 to 60 minutes.
Auditory stimuli were used to motivate the rats to run. Heart tissue sampling was conducted 48 hours after the last training session under anesthesia induced by a Ketamine-Xylazine combination. Heart tissue was harvested and stored at −80°C until analysis. RNA extraction was carried out on all tissue samples using two 50-reaction RNA extraction kits, following the manufacturer’s instructions. Real-Time PCR was performed using the Corbett Rotor-Gene 6000 system. The Real-Time PCR protocol employed the SYBR Green method with a melting curve analysis stage conducted between 65°C and 95°C. Following completion of the process and obtaining threshold cycle (Ct) values, gene expression quantification of the target variables was calculated using the (2^–ΔΔCT) mathematical method. This comprehensive method allowed for the assessment of the effects of aerobic training on the expression of genes related to cellular damage and diabetes.
For statistical analysis, one-way ANOVA followed by Tukey’s post hoc tests were applied. All statistical operations were conducted using SPSS software version 27, with significance level at p<0.05.
Findings: The results of the one-way ANOVA revealed that the expression levels of the genes p53 (p=0.001, F(3,16)=15.08) and miR-34a (p=0.001, F(3,16)=43.94) in the heart tissue of rats showed significant differences among the studied groups. The results from Tukey’s post hoc test indicated that the expression levels of p53 were significantly higher in the diabetic control group compared to the healthy training and healthy control groups (p=0.001). Meanwhile, the diabetic training group did not show a significant difference compared to the diabetic control (p=0.05) and healthy training groups (p=0.13), but a significant difference compared to the healthy control group (p=0.02). No significant difference was observed between the healthy training and healthy control groups (p=0.73). The expression level of miR-34a was significantly higher in the diabetic control group compared to the healthy training and healthy control groups (p=0.001). Additionally , a significant difference was observed between the diabetic training group and the diabetic control group (p=0.02), as well as the healthy training and healthy control groups (p=0.001). However, no significant difference was found between the healthy training and healthy control groups (p=0.52) (Figure 1).
Conclusion: The findings of the present study suggest that eight weeks of aerobic training can attenuate some of the morphological and cellular damage induced by T2DM in heart tissue. The reduction in miR-34a gene expression following aerobic training may indicate a potential therapeutic target for individuals with T2DM. However, achieving statistically significant reductions in p53 gene expression may require a larger sample size, higher exercise intensity, longer session duration, or a prolonged training period. Given the limited number of studies examining the effects of aerobic training on the expression of p53 and miR-34a genes, it remains plausible that the intensity, duration, and type of exercise play a role in modulating p53 gene responses and their interaction with miR-34a, warranting further investigation. It is also noteworthy that the eight-week aerobic training did not induce significant changes in the expression levels of p53 and miR-34a genes in healthy animals, indicating the need for additional studies employing alternative training protocols.
Ethical Considerations: This study is an extract from a senior master’s thesis that was conducted after ethical approval with the ID (IR.TABRIZU.REC.1402.022) from the Ethics Committee of the University of Tabriz.
Compliance with ethical guidelines: All ethical principles were fully observed by the researchers throughout the study.
Funding: The present study is an extract from the senior master’s thesis in exercise physiology, faculty of physical education and sport sciences, university of Tabriz, which was completed at the student’s own expense.
Conflicts of interest: The authors of the article declare that there are no conflicts of interest in the present research.
Acknowledgments: The author would like to thank the laboratory of the faculty of veterinary medicine, university of Tabriz, for their sincere cooperation in providing and maintaining the animals.
کلیدواژه‌ها [English]
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