Skripsi

Effects of prolonged and intermittent fasting on the expression of Sirtuin1 as an anti-aging biomarker using New Zealand white rabbits as subjects = Pengaruh puasa terhadap ekspresi Sirtuin1 sebagai biomarker anti-aging dengan Kelinci New Zealand White sebagai model.

Introduction: Calorie Restriction (CR) has long been known to have the ability to delay ageing, an inevitable degenerating process every organism has to go through. One mechanism by which CR extends lifespan is through increasing the expression of Sirtuin1, a NAD+-dependent deacetylase that has a multitude of function both in the nucleus and mitochondria. Sirtuin1 is said to be a metabolic sensor regulates a variety of physiological mechanisms such as stress resistance, genome stability, DNA repair mitochondrial biogenesis, and inflammation, to name a few. In this experiment, the researcher studied how intermittent and prolonged fasting affects the expression of Sirtuin1 gene in the liver of New Zealand White rabbits. Method: The rabbits were divided into three groups: control, intermittent fasting (16 hours) and prolonged fasting (40 hours). After a week of treatment, samples of liver are taken from those three groups of rabbits. RNA was isolated from the liver and further amplified using real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The relative expression of Sirtuin1 was calculated using the Livak’s method along with 18sRNA as the reference gene. Results: Sirtuin1 mRNA expression is found to be increased by 1.55-fold (p=0.179) in intermittent fasting compared to control whereas in prolonged fasting, the expression is decreased by 0.46-fold (p=0.000). Conclusion: The expression of Sirtuin1 is elevated upon the conduction of intermittent fasting in New Zealand White rabbits, which indicates that there is an increased activation of protective mechanisms induced by Sirtuin1. Further researches are required to measure directly the level of the Sirtuin1 protein and to identify the molecular mechanisms by which fasting affects the Sirtuin1 gene expression.
Keyword: fasting, calorie restriction, anti-aging, sirtuin1, rabbits


Pendahuluan: Calorie Restriction (CR) telah lama dikenal memiliki kemampuan untuk menunda penuaan, suatu proses degenerasi yang tak terhindarkan yang harus dilalui setiap organisme. Salah satu mekanisme dimana CR memperpanjang umur adalah melalui peningkatan ekspresi Sirtuin1, sebuah deacetylase yang tergantung pada NAD + yang memiliki banyak fungsi baik dalam nukleus dan mitokondria. Sirtuin1 dikatakan sebagai sensor metabolik yang mengatur berbagai mekanisme fisiologis seperti ketahanan terhadap stres, kestabilan genom, perbaikan biogenesis mitokondria, dan peradangan. Dalam percobaan ini, peneliti mempelajari bagaimana puasa intermiten dan berkepanjangan mempengaruhi ekspresi gen Sirtuin1 di hati kelinci putih Selandia Baru. Metode: Kelinci dibagi menjadi tiga kelompok: kontrol, puasa intermiten (16 jam) dan puasa berkepanjangan (40 jam). Setelah satu minggu perawatan, sampel hati diambil dari ketiga kelompok kelinci tersebut. RNA diisolasi dari hati dan selanjutnya diamplifikasi menggunakan quantitative real-time polymerase chain reaction (qRTPCR). Ekspresi relatif Sirtuin1 dihitung menggunakan metode Livak dengan 18sRNA sebagai gen referensi. Hasil: Ekspresi mRNA Sirtuin1 ditemukan meningkat 1.55 kali lipat (p=0.179) pada kelompok puasa intermiten dibandingkan dengan kontrol sedangkan pada puasa yang berkepanjangan, ekspresi menurun sebesar 0.46 kali lipat (p=0.000). Kesimpulan: Ekspresi Sirtuin1 meningkat pada hati kelinci kelompok puasa intermiten yang menunjukkan ada peningkatan aktivasi mekanisme perlindungan oleh Sirtuin1. Penelitian lebih lanjut diperlukan untuk mengukur ekspresi protein Sirtuin 1 serta menelusuri mekanisme molekuler yang menyebabkan peningkatan ekspresi mRNA tersebut.
Kata kunci: puasa, restriksi kalori, anti-aging, sirtuin1, kelinci