Exome sequencing identifies MVK mutations in disseminated superficial actinic porokeratosis.

Disseminated superficial actinic porokeratosis (DSAP) is an autosomal dominantly inherited epidermal keratinization disorder whose etiology remains unclear. We performed exome sequencing in one unaffected and two affected individuals from a DSAP family. The mevalonate kinase gene (MVK) emerged as the only candidate gene located in previously defined linkage regions after filtering against existing SNP databases, eight HapMap exomes and 1000 Genomes Project data and taking into consideration the functional implications of the mutations. Sanger sequencing in 57 individuals with familial DSAP and 25 individuals with sporadic DSAP identified MVK mutations in 33% and 16% of these individuals (cases), respectively. All 14 MVK mutations identified in our study were absent in 676 individuals without DSAP. Our functional studies in cultured primary keratinocytes suggest that MVK has a role in regulating calcium-induced keratinocyte differentiation and could protect keratinocytes from apoptosis induced by type A ultraviolet radiation. Our results should help advance the understanding of DSAP pathogenesis.

[A comparison study of pharmacokinetics between bufalin-loaded bovine serum albumin nanoparticles and bufalin in rats].

OBJECTIVE: To determine the bufalin concentration in rats' plasma by establishing a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method, and to evaluate and compare the pharmacokinetic characteristics of bufalin-loaded bovine serum albumin nanoparticles (bufalin-BSA-NP) and bufalin. METHODS: Thirty Wistar rats were randomly divided into six groups with five rats in each group, and administered with a single dose of 0.6, 0.3 and 0.15 mg/kg of bufalin-BSA-NP or bufalin, respectively. After the administration, blood samples were collected from the orbital venous plexus at designed time points (1, 5, 8, 10, 15, 20, 30, 45, 60, 120, 180, 300 and 480 min). The concentration of bufalin in plasma at different sampling time points was determined by HPLC-MS/MS. The pharmacokinetic parameters were calculated and compared. RESULTS: The established HPLC-MS/MS method had high linearity, precision and accuracy. The blood plasma area under curve, the mean retention time and the terminal half life of bufalin-BSA-NP were 1.19 to 1.81, 2.12 to 3.61 and 2.17 to 2.94 times of bufalin, respectively. CONCLUSION: Bufalin-BSA-NP has the function of sustained release thus to prolong the bufalin remaining in blood.