The Difference in Expression of Autophagy-Related Proteins in Lesional and Perilesional Skin in Adult Patients with Active and Stable Generalized Vitiligo-A Cross-Sectional Pilot Study

Assessment of serum granulysin and cathepsin-L levels in vitiligo patients

OBJECTIVE

Cellular and humoral immunity plays a role in the pathogenesis of vitiligo. T lymphocytes and natural killer cells involved in cellular immunity carry out their cytotoxic activities through perforin/granzyme-dependent granule exocytosis, in which granulysin and cathepsin-L are also involved. The aim of this study was to investigate the possible role of serum granulysin and cathepsin-L in the etiopathogenesis of vitiligo and their association with disease activity and severity.

METHODS

This randomized, prospective case-control study was conducted with 46 vitiligo patients admitted to the hospital for vitiligo between January and November 2021 and 46 healthy volunteers of similar age and gender. Serum levels of granulysin and cathepsin-L were measured by the enzyme-linked immunosorbent assay method.

RESULTS

The mean serum levels of granulysin and cathepsin-L were statistically significantly higher in vitiligo patients compared with the control group (p=0.048 and p=0.024, respectively). There was no statistically significant correlation between serum granulysin and serum cathepsin-L levels and disease severity in the patient group (r=0.30, p=0.062 and r=0.268, p=0.071, respectively). Disease activity also showed no significant association with serum granulysin and cathepsin-L levels (p=0.986 and p=0.962, respectively).

CONCLUSION

Although granulysin and cathepsin-L are molecules involved in the pathogenesis of vitiligo, the use of these molecules may not be helpful in assessing disease activity and severity. It may be helpful to conduct comprehensive and prospective studies to find new molecules to fill the gap in this area.

The multifaceted role of autophagy in skin autoimmune disorders: a guardian or culprit?

Autophagy is a cellular process that functions to maintain intracellular homeostasis via the degradation and recycling of defective organelles or damaged proteins. This dynamic mechanism participates in various biological processes, such as the regulation of cellular differentiation, proliferation, survival, and the modulation of inflammation and immune responses. Recent evidence has demonstrated the involvement of polymorphisms in autophagy-related genes in various skin autoimmune diseases. In addition, autophagy, along with autophagy-related proteins, also contributes to homeostasis maintenance and immune regulation in the skin, which is associated with skin autoimmune disorders. This review aims to provide an overview of the multifaceted role of autophagy in skin autoimmune diseases and shed light on the potential of autophagy-targeting therapeutic strategies in dermatology.

Identification and Validation of Autophagy-Related Genes in Vitiligo

Vitiligo is a common depigmented disease with unclear pathogenesis. Autophagy is crucial for maintaining cellular homeostasis and has been linked to a variety of autoimmune disorders; however, there have been no reports exploring the involvement of autophagy-related genes (ARGs) in vitiligo using bioinformatics methodologies. In this study, RNA-sequencing technology was used to identify the differentially expressed genes (DEGs) and the Human Autophagy Database (HADb) was overlapped to identify differentially expressed autophagy-related genes (DEARGs) in stable non-segmental vitiligo (NSV). Bioinformatics analyses were conducted with R packages and Ingenuity Pathways Analysis (IPA). DEARGs were further confirmed with qRT-PCR. Critical autophagy markers were detected with Western blotting analysis. We identified a total of 39 DEARGs in vitiligo lesions. DEARGs-enriched canonical pathways, diseases and bio functions, upstream regulators, and networks were discovered. qRT-PCR confirmed the significant increases in FOS and RGS19 in vitiligo lesions. Lower microtubule-associated protein 1 light chain (LC3) II/LC3I ratio and higher sequestosome 1 (SQSTM1, p62) expression were found in vitiligo lesions. In conclusion, this study provided a new insight that autophagy dysregulation appeared in stable vitiligo lesions and might be involved in the etiology of vitiligo by taking part in multiple pathways and bio functions.