Keratin 5-Cre-driven deletion of Ncstn in an acne inversa-like mouse model leads to a markedly increased IL-36a and Sprr2 expression

Familial acne inversa (AI) is an autoinflammatory disorder that affects hair follicles and is caused by loss-of-function mutations in y-secretase component genes.We and other researchers showed that nicastrin (NCSTN) is the most frequently mutated gene in familial AI.In this study,we generated a keratin 5-Cre-driven epidermis-specific Ncstn conditional knockout mutant in mice.We determined that this mutant recapitulated the major phenotypes of AI,including hyperkeratosis of hair follicles and inflammation.In Ncstnflox/flox;K5-Cre mice,the IL-36a expression level markedly increased starting from postnatal day 0 (P0),and this increase occurred much earlier than those of TNF-α,IL-23A,IL-1 3,and TLR4.RNA-Seq analysis indicated that Sprr2d,a member of the small proline-rich protein 2 family,in the skin tissues of the Ncstnflox/flox,;K5-Cre mice was also upregulated on P0.Quantitative reverse-transcription polymerase chain reaction showed that other Sprr2 genes had a similar expression pattern.Our findings suggested that IL-36a might be a key inflammatory cytokine in the pathophysiology of AI and implicate malfunction of the skin barrier in the pathogenesis of AI.

Pathogenic mutations in two Chinese patients exhibiting severe early-onset obesity

Dear Editor.During the past decades,the rising prevalence of obesity,especially in children,has become one of the major public health challenges in modern China and worldwide.This increase in prevalence of obesity can partly be attributed to high-calorie food intake and lack of exercise.Conversely,previous research has demonstrated the importance of genetic factors in the etiology of obesity.