Keratinocytes undergo significant structural remodeling during epidermal differentiation, including a broad transformation of the proteome coupled with a reduction in total cellular biomass. This suggests that intracellular digestion of proteins and organelles is necessary for keratinocyte differentiation. Here, we use both genetic and pharmacologic approaches to demonstrate that autophagy and lysosomal functions are required for keratinocyte differentiation in organotypic human skin. Lysosomal activity was required for mechanistic target of rapamycin signaling and mitochondrial oxidative metabolism. In turn, mitochondrial reactive oxygen species, produced as a natural byproduct of oxidative phosphorylation, were necessary for keratinocyte differentiation. Finally, treatment with exogenous reactive oxygen species rescued the differentiation defect in lysosome-inhibited keratinocytes. These findings highlight a reciprocal relationship between lysosomes and mitochondria, in which lysosomes support mitochondrial metabolism and the associated production of mitochondrial reactive oxygen species. The mitochondrial reactive oxygen species released to the cytoplasm in suprabasal keratinocytes triggers autophagy and lysosome-mediated degradation necessary for epidermal differentiation. As defective lysosome-dependent autophagy is associated with common skin diseases including psoriasis and atopic dermatitis, a better understanding of the role of lysosomes in epidermal homeostasis may guide future therapeutic strategies.

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Purpose:Transradial arterial access has become more popular in body interventional procedures but has not been ubiquitously adapted. This retrospective study assesses the efficacy of this approach in uterine artery embolization. Aim of the study was to compare transradial to transfemoral arterial access in patients undergoing uterine artery embolization for the treatment of fibroids. Material and methods:A total of 172 patients underwent uterine artery embolization procedures at our institute from October 2014 to June 2020. Of these, 76 patients had their operations performed via transfemoral access while 96 underwent transradial access. The peak radiation dose, fluoroscopy time, procedure time, total contrast volume, and equipment cost for each procedure were all reviewed to evaluate for statistical differences between the 2 groups.Results: All cases were technically successful without major complications. The average peak skin dose was 2281 mGy, with no statistical difference between the transradial or transfemoral cohorts. Average fluoroscopy time was 25 minutes, also with no statistical difference between the subsets. Mean procedure time was 100 min, and mean contrast volume usage was 138 mL with no statistical differences. Similarly, the average equipment cost was $2204, with no significant differences found between transradial and transfemoral access. Conclusions:With respect to many pertinent radiation parameters, transradial access was evaluated as being an equally efficacious alternative to transfemoral access in uterine artery embolization procedures. The results of this study suggest that transradial access should be considered more often, whenever viable, as an option in the uterine artery embolization treatment of fibroids.

Keratinocytes undergo significant structural remodeling during epidermal differentiation, including a broad transformation of the proteome coupled with a reduction in total cellular biomass. This suggests that intracellular digestion of proteins and organelles is necessary for keratinocyte differentiation. Here, we use both genetic and pharmacologic approaches to demonstrate that lysosomal function and autophagy are both required for keratinocyte differentiation in organotypic human skin. Lysosomal activity was required for mTOR signaling and mitochondrial oxidative metabolism. In turn, mitochondrial reactive oxygen species (mtROS), produced as a natural byproduct of oxidative phosphorylation, were necessary for keratinocyte differentiation. Finally, treatment with exogenous ROS rescued the differentiation defect in lysosome-inhibited keratinocytes. These findings highlight a reciprocal relationship between lysosomes and mitochondria, in which lysosomes support mitochondrial metabolism and the associated production of mtROS. The mtROS released to the cytoplasm in suprabasal keratinocytes triggers autophagy and lysosome-mediated degradation necessary for epidermal differentiation. As defective lysosome dependent autophagy is associated with common skin diseases including psoriasis and atopic dermatitis, a better understanding of the role of lysosomes in epidermal homeostasis may guide future therapeutic strategies.

The regulation of the pH is an important element in various biological functions. The pH distribution of the stratum corneum (SC) is considered as the gradient decreasing along surface in general while precise SC pH distribution and its dynamic changes under different environmental conditions remain to be clarified. The purpose of this study is to produce a transgenic mouse as a tool to visualize the intact SC pH in vivo. We generated a ratiometric pH-biosensor with pH-sensitive fluorescent protein, Venus H148G fused with pH-insensitive protein, mCherry (Venus H148G-mCherry), expressed specifically in the uppermost layer of stratum granulosum (SG1) using knock-in construct of SASPase gene by modified CRISPR/Cas9 system. Noninvasive confocal microscopic analysis of SC pH in living Venus H148G-mCherry mouse ear skin observed with dry objective demonstrated that upper SC is neutral compared to middle SC. Immersion of water onto SC surface enabled highresolution deeper range SC pH imaging and revealed that the SC and SG1 layer are divided into three zones with distinct pH properties rather than gradual changes across the layers. Namely, the SG1 was neutral, the middle SC was acidic, and neutral pH was again observed in the upper SC. Analysis of the 3D pH distribution of whole SC showed that the upper neutral SC zone distributed unevenly by differentiated units, and the acidic middle SC was wellmaintained. When ear skin was exposed to phosphate buffers with various pH (pH5.4, 6.6 and 7.4) by topical application, the pH of upper SC dynamically changed according to the pH applied, while the middle SC maintained its acidic pH. These findings indicated that the SC is a highly organized tissue with tightly-regulated pH layers having the distinct functions, and that the 3D in vivo pH imaging mice will provide a valuable tool to dissect the homeostatic mechanisms of SC by pH regulation.