|Cancer||Cell death||Cell cycle||Cytoskeleton||Exo/endocytosis||Differentiation||Division||Organelles||Signalling||Stem cells||Trafficking|
Effects of SIRT6 silencing on collagen metabolism in human dermal fibroblasts
Yang Baohua*† and Li Li*1
*Department of Dermatology, West China Hospital, Sichuan University, Wai nan guo xue xiang 37, Chengdu 610041, Peoples Republic of China, and †Department of Dermatology, Chengdu Second Peoples Hospital, Qingyun South Street 10, Chengdu 610017, Peoples Republic of China
SIRT6 (sirtuin 6) has been identified as an anti-aging protein, and SIRT6-deficient mice display numerous progeroid and aging-like phenotypes. However, there are no reports correlating skin aging with SIRT6. To explore how SIRT6 affects collagen metabolism and determine its role in skin aging, the levels of COL1A1 (type I collagen), COL3A1 (type III collagen) and TGFβ1 (transforming growth factor β1) mRNA expression were detected by RT-Q-PCR (real-time quantitative PCR), and MMP1 (matrix metalloproteinase 1) concentration in HDF (human dermal fibroblast) supernatants was determined by ELISA after blocking SIRT6 using siRNA (small interefering RNA). Compared with the control group, blocking SIRT6 significantly decreased the HC (hydroxyproline content). SIRT6 knockdown in HDFs inhibited the transcription of COL1A1 and prompted MMP1 secretion, but had no effect on COL3A1 and TGFβ1. Furthermore, NF-κB p65 (nuclear factor κB p65) protein in the nucleus was increased after blocking SIRT6. The results suggest that SIRT6 knockdown in HDFs influence the synthesis and degradation of collagen by hyperactive NF-κB signalling, which leads to a decrease in dermal collagen fibrils. SIRT6 may therefore play an important role in the process of skin anti-aging.
Key words: collagen metabolism, fibroblast, nuclear factor κB (NF-κB), RNA interference (RNAi), sirtuin 6 (SIRT6), skin aging
Abbreviations: COH, concentration of hydroxyproline, COP, cellular total protein, Ct, cycle threshold, DMEM, Dulbecco's modified Eagle's medium, ECM, extracellular matrix, FBS, fetal bovine serum, HC, hydroxyproline content, HDF, human dermal fibroblast, HRP, horseradish peroxidase, MMP, matrix metalloproteinase, NF-κB, nuclear factor κB, RNAi, RNA interference, RT-PCR, real-time PCR, RT-Q-PCR, real-time quantitative PCR, SIR2, silent information regulator 2, siRNA, small interfering SNA, SIRT6, sirtuin 6, TGFβ1, transforming growth factor β1
1To whom correspondence should be addressed (email firstname.lastname@example.org).
Received 2 May 2011/11 August 2011; accepted 10 October 2011
Published as Cell Biology International Immediate Publication 10 October 2011, doi:10.1042/CBI20110268
© The Author(s) Journal compilation © 2012 Portland Press Limited