Razi Journal of Medical Sciences

fa اثر تمرین هوازی برمسیر سیگنالینگ MMP-2 /miR-21 فیبروز قلبی در موش‌های نر سالمند The Effect of Aerobic Exercise on MMP-2 / miR-21 Signaling Pathway of Cardiac Fibrosis in Elderly Rats فیزیولوژی ورزش Exercise Physiology پژوهشي Research <div style="text-align: justify;">زمینه و هدف: فیبروبلاست‌های قلبی مسئول ایجاد فیبروز قلبی و برقراری تعادل در ماتریکس خارج سلولی هستند و با تولید متالوپروتئین خارج سلولی در این فرآیند دخالت دارند. هدف این پژوهش مطالعه اثر هشت هفته تمرین هوازی بر مسیر پیام‌رسانیMMP-2 /miR-21 فیبروز قلبی در رت های سالمند بود. روش‌ کار: در این <a name="_Hlk81170543"> پژوهش آزمایشی </a>18 سر موش صحرایی آزمایشگاهی نژاد ویستار با سن (24 ماه) و میانگین وزن (11/511 گرم) به ‌طور تصادفی به دو گروه کنترل (9n=) و تمرین هوازی (9n=) تقسیم شدند. پس از دو هفته سازگاری با محیط، موش‌ها با شیوه تمرین که پنج جلسه‌ تمرین به مدت یک هفته، با شدت 5 متر بر دقیقه و هر جلسه به مدت 10 دقیقه، آشنا شدند .سپس گروه تمرین هوازی برنامه اصلی خود را روی نوارگردان با شیب ثابت صفر درجه و با سرعت ثابت 12 متر بر دقیقه به مدت هشت هفته انجام دادند. زمان تمرین از ۱۰دقیقه در هفته اول به 52 دقیقه در هفته هشتم رسید. گروه کنترل در این مدت هیچ تمرینی انجام نداند. متغیر‌های تحقیق با روش RT-PCR سنجش شد. از آزمون تی مستقل برای سنجش و تحلیل داده‌ها استفاده شد و سطح معناداری 05/0 p< در نظرگرفته شد. یافته‌ها: داده‌ها نشان داد تمرین هوازی موجب افزایش معنادار بیان ژنmiR-21 و کاهش معنادار بیان کلاژن بین سلولی و بیان ژنMMP-2 در گروه تمرین شد. به نظر می‌رسد تمرین هوازی با افزایش miR-21 از مسیر پیام رسانPTEN، موجب کاهش بیان MMP-2  و مقدار رسوب کلاژن در فضای بین سلولی بطن چپ موش های سالمند شده است. نتیجه‌گیری: نتایج نشان داد هشت هفته تمرین هوازی در موش‌های صحرایی سالمند موجب کاهش فیبروز قلبی و هایپرتروفی در بطن چپ می‌شود.</div> <div style="text-align: justify;">Background & Aim: The concept of survival has changed since the twentieth century to guarantee quality of life in the twenty-first century(1).Aging is associated with a certain degree of interstitial fibrosis, which progresses to heart failure. Therefore, finding new and practical methods is an important and necessary help to reduce heart tissue fibrosis in the elderly(2).Providing mechanisms by which exercise can benefit the cardiovascular system may provide a picture of a healthy heart, and this process provides new ways to prevent and treat heart disease. The most common heart disease associated with aging is diastolic dysfunction and is referred to as heart failure along with the maintenance of the injection fraction. Heart failure increases stiffness and myocardial fibrosis and is associated with poor endothelial function. Fibrosis is a complex reactive tissue that occurs due to excessive accumulation of compounds, especially collagen, and is one of the biological causes of changes in the heart. The findings show that fibrosis occurs in the hearts of older mice and humans(3).In mammals, the structure of the extracellular matrix (ECM) of the heart is 85% collagen and 11% collagen. The ability to make ECM compounds depends on its cell type. For example, fibroblasts and smooth muscle cells make type I and collagen, while myocytes and endothelial cells make type I collagen. Changes in ECM protein profiles can affect heart function and shape(4). MicroRNAs (miRNAs) are small, non-coding RNAs of 18 to 25 nucleotides that regulate gene expression at the post-transcriptional level in physiological and pathological conditions(5). MicroRNAs are partially and regionally complemented by target mRNA, thereby inhibiting its translation or degradation (14). miR-21 is overexpressed during fibrosis and can regulate the fibrogenic process in different organs and tissues from different pathways. MiR-21 has been shown to directly target phosphate and tensin homologue (PTEN) and It can regulate the fibrosis process from the phosphoinositide 3-kinase / AKT pathway by targeting PTEN(6). Matrix metalloproteins (MMPs) are zinc-dependent endonucleases (Zn) that are capable of degrading various extracellular matrix (ECM) compounds and are made and stored in the form of pre-enzymes. MMP-2- Collagenase A is a 72 kDa protein whose gene is located on chromosome 16 in humans and arm 12.2 q and in mice on chromosome 8.Kwak showed 12 weeks of training significantly reduced age-induced intercellular space collagen in mice(2). Eight weeks of regular swimming in male diabetic rats significantly reduced TGF-β and normalized cardiac MMP-2. miR-21has multiple functions related to exercise and heart disease and Significantly, miR-21 is highly dependent on the target genes it regulates(7). In the study of SAP et al., Eight weeks of high-intensity and endurance training performed on a statistical population and the amount of miR-21 in the plasma of 10 pre-test athletes were measured by RT-QPC method. After eight weeks and one hour of rest after the test, a decrease in miR-21 was observed in the intense exercise group (17). Methods: The present study is an experimental and basic study with a post-test design with a control group. All stages of the research were carried out in accordance with the ethical principles of working with laboratory animals approved by Shahid Beheshti University of Medical Sciences in accordance with the 2006 Helsinki Protocol.  In this experimental study, 18 Wistar rats with age (24 months) and mean weight (537±5 g) were randomly divided into control (n = 9) and aerobic exercise (n = 9) groups. After getting acquainted with the environment and training method, the training group performed their program on a treadmill with a constant slope of zero degrees and a constant speed of 12 meters per minute for eight weeks and 5 days a week. Training time increased from 10 minutes in the first week to 52 minutes in the eighth week. The control group did not perform any exercises during this period. At the end of every session warm up were performed. Research variables were measured by RT-PCR. To make the cDNA pattern, miRNA-21 MMP-2 Takara Master Mix Kit was used and the instructions were followed. Independent t-test was used to measure and analyze the data and a significance level of p <0.05 was considered(8, 9).  Results: The results of data analysis using independent t for ventricular collagen percentage showed that there was a significant difference between the control and exercise groups (P = 0.001, t = 506.5), data analysis using independent t for expression of miR-21 gene showed that there is a significant difference between the control and exercise groups (P = 0.006, t = 131.3) and data analysis using independent t for MMP-2 gene showed that there is a significant difference between the control and exercise groups (P = 0.027, t = 441.2). Conclusion: <a name="_Hlk79347180">Sub-maximal intensity aerobic exercise significantly increased miR-21 followed by downstream suppression of MMP-2 and decreased collagen deposition in the left ventricle of healthy elderly mice. Collagen is known as one of the markers of fibrosis and physical activity can reduce its deposition and formation</a>(2).Suppress collagen production is a way to reduce the expression of the MMP-2 gene by the PTEN I. It should be noted that the signal pathways for fibrosis are interconnected, for example, the PI3K pathway positively regulates Smad3 transcription and increases collagen production(10). One way to reduce collagen production is to reduce the expression of the MMP-2 gene, Exercise with moderate intensity of FGF-2 expression and downstream uPA / tPA and MMP-2 expression in elderly rats significantly reduce and increase collagen expression significantly. It is important to note that a decrease in MMP-2 may also be due to an increase in TIMP-2 after physical activity. Physical activity increases TIMP-2 and its affinity for MMP-2 is dramatically high .These pathways affect the production of miR-21 and, in contrast to miR-21, regulate these pathways by targeting target proteins. In other words, miR-21 plays a key role in this network. Many of these proteins have an inhibitory role on metalloproteins: MMP-2 destroys the extracellular matrix and suppresses the PTEN pathway in cardiac fibroblasts(6). The results showed that aerobic exercise significantly increased miR-21 gene expression and significantly decreased intercellular collagen expression and MMP-2 gene expression. It seems that aerobic exercise with increased miR-21 decreased the expression of MMP-2 and the amount of collagen deposition in the intercellular space.  </div> فیبروز قلبی, تمرین هوازی, miR-21, MMP-2, کلاژن Cardiac fibrosis, Aerobic exercise, miR-21, MMP-2, Collagen 1 13 http://rjms.iums.ac.ir/browse.php?a_code=A-10-6274-1&slc_lang=fa&sid=1 fatemeh Ghalambor فاطمه قلمبر 3900319475328460088043 0000000234874975 No PhD Student of Sport Physiology, Science and Research Branch, Islamic Azad University, Tehran, Iran دانشجوی دکتری تخصصی فیزیولوژی ورزشی، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران Hossein Abednatanzi حسین عابد نطنزی abednazari@gmail.com 3900319475328460088044 0000000166381131 Yes Assistant Professor, Department of Physical Education and Sport Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran گروه تربیت بدنی و علوم ورزشی، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران Mandana Gholami ماندانا غلامی 3900319475328460088045 000000018960-4123 No Assistant Professor, Department of Physical Education and Sport Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran گروه تربیت بدنی و علوم ورزشی، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران Farshad Ghazaliyan Ghazaliyan فرشاد غزالیان 3900319475328460088046 0000000258050559 No Assistant Professor, Department of Physical Education and Sport Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran گروه تربیت بدنی و علوم ورزشی، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران