Skin integrity is essential for protection from external stress and trauma. Defects in structural proteins such as keratins cause skin fragility, epitomized by epidermolysis bullosa (EB), a life-threatening disorder. Here we show that dominant mutations of KLHL24, encoding a cullin 3-RBX1 ubiquitin ligase substrate receptor, cause EB. We have identified start-codon mutations in the KLHL24 gene in five patients with EB. These mutations lead to truncated KLHL24 protein lacking the initial 28 amino acids (KLHL24-ΔN28). KLHL24-ΔN28 is more stable than its wild-type counterpart owing to abolished autoubiquitination. We have further identified keratin 14 (KRT14) as a KLHL24 substrate and found that KLHL24-ΔN28 induces excessive ubiquitination and degradation of KRT14. Using a knock-in mouse model, we have confirmed that the Klhl24 mutations lead to stabilized Klhl24-ΔN28 and cause Krt14 degradation. Our findings identify a new disease-causing mechanism due to dysregulation of autoubiquitination and open new avenues for the treatment of related disorders.

Common delivery routes for chemotherapeutics are based on circulation, which faces clinical limitations to local delivery efficiency, and the conflict between the dose for anticancer effect and the systemic toxicity. The recent advances in localized delivery strategies aim to improve drug accumulation at the target site or directly transport into cells. However, most are not equipped to provide additional momentum in the process of cargo release, propagation, and intracellular movement, which limit their locomotion that relies on passive diffusion. In this work, a multimicrochannel microneedle microporation (4M) platform that achieves high efficiency, safety, and uniformity for in vivo intracellular delivery is proposed. By high precision 3D printing, internal microchannels are implemented through the microneedle, which offer a concentrated, safe electric field that not only accelerates the movement of cargo into deep tissue under electrophoresis, but also triggers cell electroporation, achieving enhanced transport across cell membrane. The platform proves efficient for the delivery of chemotherapeutics in solid tumors in vitro and in vivo, with significantly enhanced anticancer effect and reduced systemic toxicity. The platform serves as a general-purpose delivery tool to emerging drugs in vivo.

Aim: Silent mating type information regulator 2 homolog 1 (SIRT1) functions as an atheroprotective factor in vascular biology, and genetic variations in SIRT1 are associated with coronary artery calcification and type 2 diabetes in several populations. In this study, we investigated the relationship between the mRNA expression levels of the SIRT1 gene and single nucleotide polymorphisms (SNPs) in the context of acute coronary syndrome (ACS). Methods: Whole-genome expression microarray and real-time PCR techniques were used to detect the gene expression levels, and Western blotting was performed to determine the protein expression level. The four selected SNPs were genotyped in a Taqman genotyping platform. Results: Compared with that observed in the controls, the mRNA expression levels of the SIRT1 gene in the microarray study were significantly lower in the acute myocardial infarction (AMI), unstable angina (UA) and overall ACS patients. These results were replicated in another independent cohort with respect to the mRNA (AMI, p 0.001; UA, p 0.001; ACS, p 0.001) and protein (p 0.05) levels. Furthermore, the relationship between the SIRT1 mRNA expression and the genotypes of four possible functional SNPs (rs12778366, rs3758391, rs2273773 and rs4746720) was tested, the results of which showed significant differences in the SIRT1 mRNA expression among the allelic genes of rs3758391 (p 0.01) in the healthy participants. Conclusions:The present results confirm that the SIRT1 gene plays a protective role against ACS and that the rs3758391 SNP affects the mRNA expression in healthy participants, providing new insight into the processes regulating the genetic control of the SIRT1 gene with respect to the pathogenesis of ACS. J Atheroscler Thromb, 2015; 22:165-182.