Investigation Of The Relationship Between Promoter Methylation Of Human Leukocyte Antigen(HLA)-G And Psoriasis

Objectives:This study was conducted to measure the methylation levels of the HLA-G gene promoter region in the epidermis of psoriasis patients with lesions,non-lesion areas and normal controls,and to contrast the methylation levels of the HLA-G gene promoter region between different samples,and to also discuss the relationship between the methylation levels of the HLA-G gene promoter region in the epidermis and psoriasis.Methods:Fifty-six patients with active psoriasis vulgaris visiting the outpatient clinic of the Institute of Dermatology,Chinese Academy of Medical Sciences from 2019 to 2020 were randomly selected,and an additional 28 cases of surgically excised normal skin from our dermatological procedure were also randomly selected as control samples.The correlation between the level of methylation in the promoter region of the HLA-G gene and the severity of psoriasis was analyzed by comparing different groups of psoriatic lesions,non-lesion sites and control epidermis using the Sodium Bisulfite Sequencing.Results:All patients with psoriasis vulgaris had HLA-G gene promoter region methylation modifications in lesions,non-lesional epidermis and normal epidermis,in which the average HLA-G gene promoter region methylation levels were(36.69±7.92)%and(37.38±6.90)%in lesions and non-lesional epidermis of patients,respectively,compared with(57.23± 11.89)%in the control group.The methylation levels of HLA-G gene promoter region in both lesions and non-lesion sites were significantly lower in psoriasis patients than in healthy normal subjects(P<0.001),and there was no statistically significant difference between the methylation modification levels of epidermal HLA-G promoter region in psoriasis lesions and non-lesion sites(t=-0.66,P>0.05).The level of methylation in the HLA-G promoter region at the lesion site did not relate to the severity of psoriasis(r=-0.24,P>0.05).Conclusions:The markedly reduced level of methylation in the promoter region of the HLA-G gene in the epidermis of patients with psoriasis may be an epigenetic marker in patients with psoriasis.The level of methylation in the epidermal HLA-G gene promoter region at the lesion sites of psoriasis patients was not correlated with their severity of the disease significantly.