Experimental study on the effect of luteolin on the proliferation, apoptosis and expression of inflammation-related mediators in lipopolysaccharide-induced keratinocytes.

OBJECTIVE: This study aimed at exploring the effects of luteolin on psoriasis-like cell model proliferation, apoptosis regulation and the expression of inflammation-related mediators. METHODS: A Cell Counting Kit-8 (CCK-8) assay was used to determine the survival rate of human immortalized keratinocytes (HaCaT cells) and normal human epidermal keratinocytes (NHEK cells) following stimulation with luteolin and lipopolysaccharide (LPS). Western blot and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to detect the protein and mRNA expressions of nuclear factor (NF)-κB p65 and interleukin (IL)-6 after LPS stimulation. Then a luteolin stimulation protocol (10 µmol/L, 24 h) was determined and a reasonable LPS stimulation concentration (20 µg/mL, 24 h) was chosen to establish the psoriasis cell model. Keratinocytes in luteolin pre-treatment and control groups were stimulated with 20 µg/mL LPS for 24 h, and the expressions of NF-κB p65 and IL-6 were detected by western blot and RT-qPCR. The apoptosis of HaCaT cells was detected by flow cytometry, and the enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of psoriasis-related inflammatory factors. RESULTS: CCK-8 assay indicated that luteolin inhibited the proliferation of keratinocytes. LPS stimulated the proliferation of keratinocytes and upregulated the expression of NF-κB p65 and IL-6 in a concentration-dependent manner, and induced psoriasis-like changes. Furthermore, the protein and mRNA expression levels of NF-κB p65 and IL-6 were decreased in the luteolin pre-stimulation group (p < 0.05). Treatment with luteolin downregulated the expression of the LPS-induced inflammatory mediators in keratinocytes (p < 0.05). The flow cytometry results showed that luteolin induced HaCaT cells apoptosis. Finally, ELISA results demonstrated that luteolin inhibited the release of the IL-17, IL-23 and tumor necrosis factor α (TNF-α) in the pre-stimulation group (p < 0.05). CONCLUSION: This study confirmed that luteolin can effectively relieve inflammatory mediators in LPS-induced keratinocyte models of psoriasis, which suggested the potential of luteolin in treating psoriasis.

[Analysis of genetic variant in a case of sporadic neurofibromatosis type I with alopecia areata and vitiligo].

OBJECTIVE: To explore the genetic basis for a patient with clinically suspected neurofibromatosis type I, alopecia areata and vitiligo. METHODS: Variant of the NF1 gene was detected by chip capture and high-throughput sequencing. Candidate variant was verified by Sanger sequencing of the family trio. RESULTS: The patient was found to harbor a novel missense c.1885G>A (p.Gly629Arg) variant of the NF1 gene, for which neither parent was carrier. The variant was not recorded in the public database. Based on the guidelines for genetic variation of the American College of Medical Genetics and Genomics, the c.1885G>A missense variant was predicted to be pathogenic (PS1+PS2+PM2+PP3+PP4). CONCLUSION: The c.1885G>A missense variant probably underlay the disease in this child. Above finding has enriched the spectrum of the NF1 gene variants.