Pengaruh Paparan Asap Rokok Jangka Panjang terhadap Ekspresi mRNA Muscle-specific RING-Finger protein-1 (MuRF-1) pada Otot Gastrocnemius Tikus Putih Jantan Jenis Rattus norvegicus

FATIMAH ATH THAHIRAH, dr. R. Jajar Setiawan, M.Sc, Ph.D

2023 | Skripsi | S1 KEDOKTERAN

Latar belakang : Asap rokok merupakan salah satu penyebab dari berbagai masalah kesehatan pada sistem organ tubuh manusia, termasuk sistem muskuloskeletal. Reactive oxygen species (ROS) yang meningkat akibat rokok berujung pada kondisi stres oksidatif dalam tubuh. Proses stres oksidatif ditandai oleh peningkatan ROS yang diteliti pada otot dapat mengaktifkan nuclear factor κb (NF-κB). Pengaktifan NF-κB dapat menginduksi atrofi otot melalui ekspresi dari Muscle-specific RING-Finger protein-1 (MuRF-1). Deteksi proses atrofi otot dapat diketahui melalui evaluasi mRNA MuRF-1 sebagai penanda atrofi otot. Tujuan : Mengkaji ekspresi mRNA MuRF -1 dan pengaruh peningkatan durasi terhadap ekspresi mRNA MuRF-1 pada otot gastrocnemius tikus putih jantan jenis Rattus norvegicus yang diberikan paparan asap rokok jangka panjang selama 20, 40, dan 60 hari. Metode : Penelitian ini menggunakan metode quasi-experimental posttest only design. Subjek penelitian ini menggunakan ±50-100 mg irisan beku otot gastrocnemius tikus putih jenis Rattus norvegicus yang disimpan di lemari pendingin -80˚C, Laboratorium Departemen Fisiologi, FK-KMK UGM dari penelitian sebelumnya. Subjek dibagi menjadi tiga kelompok kontrol (KH20, KH40, dan KH60) dan tiga kelompok perlakuan (PH20, PH40, dan PH60). Setiap kelompok perlakuan sudah diberikan paparan asap rokok sebanyak 10 batang rokok/hari selama 20, 40, dan 60 hari. Pengambilan data rerata ekspresi mRNA MuRF-1 menggunakan teknik PCR dan elektroforesis. Hasil penelitian dianalisis menggunakan aplikasi Image J dan diuji normalitasnya dengan uji Saphiro-Wilk, dilanjutkan dengan uji ANOVA serta post-hoc LSD untuk perbandingan antar kelompok menggunakan aplikasi IBM SPSS statistic. Hasil : Ekspresi mRNA MuRF -1 pada otot gastrocnemius tikus putih jantan jenis Rattus norvegicus secara signifikan lebih tinggi pada kelompok perlakuan dibandingkan kontrol (p=0,001). Rerata ekspresi mRNA MuRF -1 kelompok PH20 (0,72±0,04) lebih tinggi dari KH20 (0,52±0,07), PH40 (0,88±0,21) lebih tinggi dari KH40 (0,51±0,09), dan PH60 (0,81±0,09) lebih tinggi dari KH60 (0,50±0,06). Perbedaan ekspresi mRNA MuRF -1 antara kelompok PH20, PH40, dan PH60 tidak signifikan secara statistik (p = 0,295). Kesimpulan : Ekspresi mRNA MuRF -1 pada otot gastrocnemius tikus putih jantan jenis Rattus norvegicus yang diberi paparan asap rokok jangka panjang durasi 20, 40, dan 60 hari lebih tinggi dibandingkan dengan kontrol dan peningkatan durasi paparan asap rokok tidak diikuti peningkatan ekspresi mRNA MuRF -1.

Background : Cigarette smoke is one of the causes of various health problems in the human body's organ systems, including the musculoskeletal system. Reactive oxygen species (ROS) that increase due to smoking lead to oxidative stress in the body. The process of oxidative stress is characterized by an increase in ROS which has been studied in muscle to activate nuclear factor κb (NF-κB). NF-κB activation can induce muscle atrophy through the expression of Muscle-specific RING-Finger protein-1 (MuRF-1). The process of detecting muscle atrophy can be identified by evaluating MuRF-1 mRNA as a marker of muscle atrophy. Objective: To study MuRF-1 mRNA expression and the effect of increasing duration on MuRF-1 mRNA expression in the gastrocnemius muscle of Rattus norvegicus male white rats exposed to long-term cigarette smoke for 20, 40, and 60 days. Methods: This study used a quasi-experimental posttest only design method. The subjects of this study used ±50-100 mg of gastrocnemius muscle slices of male white rats of the Rattus norvegicus which were stored in a -80˚C freezer, Laboratory of the Department of Physiology, FK-KMK UGM from previous studies. Subjects were divided into three control groups (KH20, KH40, and KH60) and three treatment groups (PH20, PH40, and PH60). Each treatment group was given exposure to cigarette smoke of 10 cigarettes/day for 20, 40, and 60 days. Mean data collection of MuRF-1 mRNA expression used PCR and electrophoresis techniques. The results were analyzed with the Image J application and tested for normality with the Shapiro-Wilk test, followed by ANOVA and LSD post-hoc tests for comparisons between groups using the IBM SPSS statistical application. Results: MuRF -1 mRNA expression in the gastrocnemius muscle of Rattus norvegicus male white rats was significantly higher in the treatment group than in the control group (p=0.001). The mean MuRF -1 mRNA expression in the PH20 group (0.72±0.04) was higher than KH20 (0.52±0.07), PH40 (0.88±0.21) was higher than KH40 (0.51± 0.09), and PH60 (0.81±0.09) was higher than KH60 (0.50±0.06). The difference in MuRF -1 mRNA expression between the PH20, PH40, and PH60 groups was not statistically significant (p = 0.295). Conclusion : MuRF -1 mRNA expression in the gastrocnemius muscle of Rattus norvegicus male white rats exposed to long-term cigarette smoke for a duration of 20, 40, and 60 days was higher than the control and an increase in the duration of exposure to cigarette smoke was not followed by an increase in MuRF -1 mRNA expression.

Kata Kunci : rokok, otot, tikus, atrofi otot, MuRF-1