MicroRNA-146a and miR-99a are potential biomarkers for disease activity and clinical efficacy assessment in psoriasis patients treated with traditional Chinese medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: Psoriasis is a common chronic inflammatory skin disease. A number of clinical investigations have indicated that traditional Chinese medicine (TCM) is an effective and safe treatment for psoriasis. Zhuhuang Granule (ZG) is a modified formulation of Zhuhuang Decoction, which is used traditionally in China for the treatment of psoriasis in clinical practice.

AIM OF THE STUDY: Recent studies have found that microRNAs (miRNAs) play important roles in the pathogenesis of some skin diseases. The objective of our study was to investigate the effect of ZG on the expression of miRNAs in peripheral blood mononuclear cells (PBMCs) from psoriasis patients and to identify specific miRNA biomarkers for psoriasis disease activity and assessment of clinical efficacy.

MATERIALS AND METHODS: Twenty-five psoriasis patients and 15 healthy control subjects were recruited to participate in this study from October 2013 to October 2014. Microarray and quantitative real-time PCR (qRT-PCR) were used to measure the global miRNA expression in PBMCs from psoriasis patients and healthy control subjects. We also measured the changes in the Psoriasis Area and Severity Index (PASI) score and miRNA expression of patients before and after treatment with ZG.

RESULTS: The microarray results showed that 26 miRNAs were upregulated and 13 miRNAs were decreased in psoriasis patients. qRT-PCR validated 3 upregulated miRNAs (miR-146a, miR-31, miR-192-5p) and 2 downregulated miRNAs (miR-99a, miR-200c) in PBMCs from psoriasis patients compared with healthy controls (p<0.01). Moreover, after 8 weeks of ZG treatment, patients achieved a significant reduction in PASI scores. QRT-PCR analysis indicated that the expression of miR-146a and miR-99a is closely correlated with psoriasis severity (R2 =0.772, p<0.01; R2 =0.672, p<0.01).

CONCLUSION: We suggest that both miR-146a and miR-99a may serve as potential biomarkers for disease activity and clinical efficacy in psoriasis patients treated with ZG.