Psoriasis is a disease with a proinflammatory base, in which an increased expression of leptin, tumor necrosis factor alpha (TNF-α), interleukin (IL) IL-12/23, IL-6, is observed. A drug used in the treatment of psoriasis of moderate and acute strength is the monoclonal antibody anti-TNF-adalimumab. The goal of this study was to evaluate the influence of adalimumab on changes in the expression profile of leptin-related genes in human keratinocyte cells exposed to lipopolysaccharide A and analyze if adalimumab acts via leptin pathways. The evaluation of changes of the pattern of genes connected with leptin and proteins coded by them was marked in a culture of human keratinocytes (HaCaT) exposed to 1 µg/mL lipopolysaccharide A (LPS) for 8 h in order to induce the inflammatory process, then to 8 µg/mL of adalimumab for 2.8 and 24 h in comparison with the control (cells not treated with the substances). The techniques used were mRNA microarray, Real-Time Quantitative Reverse Transcription Reaction (RTqPCR), Enzyme-Linked Immunosorbent Assay (ELISA), as well as transfections of HaCaT culture with leptin small interfering RNA (siRNA) in order to see whether adalimumab works through pathways dependent on leptin. A statistically lower expression of leptin and its receptors was observed under the influence of the drug, independent of the exposition time of keratinocytes to adalimumab. In the cells transfected with leptin siRNA, a lower concentration of JAK2 and STAT3 proteins was observed, which confirms that adalimumab works through pathways dependent on leptin. Adalimumab has a modulatory effect on the gene expression pattern and the proteins coded by them connected with leptin in keratinocytes treated with LPS in vitro.
Keywords: adalimumab; keratinocytes; leptin; lipopolysaccharide A; mRNA; siRNA; signaling pathway.