Journal of dermatological science最新文献

Background: Progressive symmetric erythrokeratodermia (PSEK) is a group of hereditary cornification disorders characterized by symmetrical, progressive erythroderma and hyperkeratosis over the body. Loss-of-function variants in SLURP1, encoding secreted Ly-6/uPAR-related protein 1, is known to cause Mal de Meleda, an autosomal recessive palmoplantar keratoderma.

Objective: To identify the genetic basis and the pathogenesis of a sporadic patient with PSEK.

Methods: Whole-exome sequencing and Sanger sequencing were performed to identify the pathogenic variant(s). The expression of SLURP1 was assessed on the patient's skin tissue by immunofluorescence. Western blotting (WB) and immunofluorescence (IF) were performed on eukaryotic overexpression systems to evaluate the signal peptide (SP) cleavage, subcellular localization and secretion of the mutant SLURP1. Combined WB and IF analyses were conducted on cells co-transfected with FLAG-tagged wild-type SLURP1 and untagged SLURP1-Ala22Asp.

Results: We identified a de novo heterozygous variant in SLURP1 (c.65A > C, p.Ala22Asp) affecting the first residue before SP cleavage site in a patient with PSEK. This variant abolished the cleavage site of SP, resulting in translocation deficiency to the Golgi apparatus and decreased secretion of the mutant SLURP1. We also found that the SLURP1-Ala22Asp exerted a dominant-negative effect by impeding the SP cleavage of the wild-type SLURP1 and affecting its subcellular localization and secretion in a dose-dependent manner.

Conclusion: We reported the first autosomal-dominant variant in SLURP1 associated with a new phenotype of PSEK in a patient, emphasizing the genetic and clinical heterogeneity of SLURP1-associated genodermatoses.

Background: Cryoablation is an integral therapeutic approach in dermatology for eliminating viral warts and benign tumors by damaging tissue through freeze-thaw cycles. Rapid thawing of the frozen area by warming it with fingertips during cryoablation is a common technique in Japan; however, its efficacy has not been elucidated.

Objective: This study aimed to evaluate the effect of rapid thawing on cryoablation-treated skin and clarify the underlying mechanisms using cryoablation model mice.

Methods: Cryoablation was performed on the dorsal skin of mice using a liquid nitrogen-soaked cotton swab, followed by rapid thawing by warming with fingertips or natural thawing without treatment. The effects on skin ulcers, immune cell infiltration, and oxidative stress were assessed.

Results: Rapid thawing enlarged cryoablation-induced skin ulcers. The numbers of cryoablation-induced CD3⁺ T cells, neutrophils, neutrophil extracellular traps (NETs), and TUNEL⁺ cells increased with rapid thawing. Visualization of oxidative stress in OKD48 transgenic mice showed that oxidative stress signals in the cryoablation-treated area were enhanced with rapid thawing. Real-time PCR analysis of mouse skin demonstrated that cryoblation-induced levels of NOX2 and HO-1 were significantly elevated with rapid thawing. In mouse melanoma tumors treated with cryoablation, rapid thawing significantly inhibited tumor growth and increased the infiltration of neutrophils, NETs, and TUNEL⁺ cells compared to the group without rapid thawing.

Conclusion: Rapid thawing during cryoablation enhances neutrophil and lymphocyte infiltration, increases oxidative stress, and induces cell death, leading to greater tissue destruction in mice. Dermatologists should consider employing rapid thawing techniques during cryoablation when higher therapeutic intensities are required.

Background: Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular endothelial dysfunction and damage, immune dysregulation and fibrosis. Endothelial mesenchymal transition (EndoMT) has been implicated in the skin fibrosis of SSc. Many studies have demonstrated that janus kinase type2 (JAK2) inhibitor can alleviate skin fibrosis in both SSc patients and bleomycin (BLM)-induced mouse models of SSc. However, the potential therapeutic effect of JAK2 inhibitor on EndoMT in SSc skin, along with the underlying molecular mechanisms, remains unexplored.

Objective: To investigate the effects of JAK2 inhibitor on the EndoMT in SSc skin and to elucidate the associated molecular mechanisms.

Methods: Wild-type female C57BL/6 mice were divided into several groups to assess the effects of JAK2 inhibitor on EndoMT through H&E staining, masson staining, immunofluorescence and single-cell RNA-sequencing (scRNA-seq). Cultured human umbilical vein endothelial cells (HUVECs) were used to explore the mechanism of action of JAK2 inhibitor on EndoMT using immunofluorescence, quantitative RT-PCR, RNA sequencing and western blot.

Results: JAK2 inhibition improved skin fibrosis, reduced CD31/α-SMA co-localisation and the number of EndoMT-activated vascular endothelial cells in bleomycin-induced SSc mice. Treatment of HUVECs with TGF-β or BLM led to a myofibroblast-like morphology and markers, along with downregulation of endothelial cell features, which were reversed following JAK2 inhibition. The activation of the PI3K/Akt/mTOR pathway was involved in EndoMT in HUVECs induced by TGF-β/BLM, and this activation was attenuated by JAK2 inhibition.

Conclusions: JAK2 inhibitor may serve as an effective treatment for EndoMT in SSc, potentially through modulation of the PI3K/Akt/mTOR signaling pathway.

Vitiligo, a complex autoimmune disorder characterized by melanocyte destruction, arises from an intricate interplay of genetic, epigenetic, immune, and environmental factors. Genome-wide association studies (GWAS) have identified over 50 susceptibility loci, including key genes within the MHC region and those involved in immunity, oxidative stress, and melanogenesis. Concurrently, epigenetic research has unraveled regulatory networks critical to vitiligo pathogenesis, with a focus on DNA methylation and non-coding RNAs (e.g., microRNAs, long non-coding RNAs, and circular RNAs). These advancements provide deeper insights into gene regulation, immune processes, and cellular dynamics. This review integrates findings from genetic and epigenetic studies to offer a comprehensive understanding of molecular mechanisms of vitiligo, paving the way for innovative, personalized therapeutic approaches.

Background: Xeroderma pigmentosum (XP) is caused by impaired DNA repair of UV-induced dipyrimidine-photoproducts. XP cells also show impaired repair/removal of ROS or oxidative DNA lesions caused by UV or 4-nitroquinolline 1-oxide (4NQO). Gene profiling indicated that inflammatory response-related genes are significantly upregulated after UV exposure in XP-A model mice.

Objective: Since XP cells are in the state of oxidative stress and inflammation, we aimed to search for therapeutic agents from anti-oxidants/anti-inflammatory drugs, that potentially improve XP symptoms.

Methods: Several antioxidants were examined for reducing 4NQO-induced oxidative cytotoxicity or UV-induced oxidative DNA damage in XP-A cells. Among them, we focused on melatonin and evaluated its improving effect for Xpa-deficient MEF on UV-induced cytotoxicity and ROS production, and for Xpa-deficient mice on UV-induced skin tumorigenesis and auditory brainstem responses as one of the neurological symptoms.

Results: Melatonin and nicotinamide attenuated 4NQO-induced oxidative cytotoxicity. UV-induced intracellular ROS production and cytotoxicity were improved by melatonin for Xpa-deficient MEF. Finally, the administration of melatonin mitigated UV-induced skin inflammation and tumorigenesis and suppressed hearing deterioration in Xpa-deficient mice.

Conclusion: Our results show that melatonin could alleviate XP symptoms through its anti-inflammatory and antioxidant properties.