Genome‐wide association studies in Japanese women identified genetic loci associated with wrinkles and sagging

Abstract

In the field of beauty, wrinkles and sagging are the most prominent phenotypes of aging phenomena on the face, and effective methods for their prevention and improvement are desired. Wrinkles and sagging are primarily caused by external factors, such as ultraviolet rays, as well as the age-related disintegration of collagen fibres, 1,2 decreased collagen production by dermal fibroblasts, 3,4 and the increased production of matrix metalloproteinases. [5][6][7] Genomewide association studies (GWAS) on skin aging have recently been conducted, and the findings obtained clearly showed that some individuals were genetically predisposed to more rapid skin aging.Single nucleotide polymorphisms (SNPs) have been associated with a number of skin properties, including wrinkles, eyelid sagging, skin colour, the type of sunburn, and skin barrier function. [8][9][10][11][12][13][14] The relationships between these phenotypes and SNPs markedly differ

Genome‐wide association studies in the Japanese population identified genetic loci and target gene associated with epidermal turnover

“…Statistical analysis was performed according to previous methods. 9 A GWAS was conducted by applying a multiple linear regression in an additive genetic model. To counteract departure from normality, a rank-based inverse normal transformation was applied to the phenotype data.…”

“…Genotyping and quality control were performed according to previous methods. 9 First, DNA was extracted from saliva collected from subjects and genotyped using Axiom® Genome-Wide CHB 1 & CHB 2 Array Plate Set (Affymetrix). Approximately 870 000 SNPs were identified.…”

“…Cell culture and siRNA transfection were performed according to previous methods. 9,17 Japanese-derived epidermal keratinocytes (AIK1) were cultured in Keratinocyte-SFM (Invitrogen). AIK1 cells were seeded on 12-well plates and cultured for 24 h. Culture medium was replaced with OPTI-MEM® (Thermo Fisher Scientific) containing lipofectamine RNAiMAX (Thermo Fisher Scientific) and 50 nM of AccuTarget™ negative control siRNA or AccuTarget™ Genome-wide Predesigned siRNA targeting SPINT2 (Bioneer).…”

“…RNA isolation and real-time PCR were performed according to previous methods. 9 Total RNA was extracted from cultured AIK1 cells using RNAiso Plus (Takara Bio), and cDNA was synthesized by PrimeScript™ RT Master Mix (Takara Bio). Real-time PCR was performed with TB Green® Premix Ex Taq™ II (Takara Bio) using a StepOnePlus Real-Time PCR System (Thermo Fisher Scientific).…”

“…This technique is actively used in the fields of medicine, beauty and health. GWAS have been conducted on skin phenotypes such as pigment spots, wrinkles and rough skin, [6][7][8][9] but there is little analysis of epidermal turnover. Therefore, we conducted a GWAS using corneocyte area as an indicator to identify genetic regions associated with epidermal turnover in the Japanese population.…”