Fine Mapping Analysis of the MHC Region to Identify Variants Associated With Chinese Vitiligo and SLE and Association Across These Diseases

Association between miR-202, miR-211, and miR-1238 gene polymorphisms and risk of vitiligo

Vitiligo, as a common pigment defect in the skin, hair, and mucous membranes, results from the destruction of melanocytes. Recent investigations have shown that miRNA dysregulation contributes in the pathogenesis of vitiligo. Therefore, in this research, our aim is to explore the relationship between miR-202 rs12355840, miR-211 rs8039189, and miR-1238 rs12973308 polymorphisms and susceptibility to vitiligo. A total number of 136 vitiligo patients and 129 healthy individuals as a control group were included in this research. The salting out approach was implemented to extraction genomic DNA. The genetic polymorphisms of miR-202 rs12355840, miR-211 rs8039189, and miR-1238 rs12973308 were determined using PCR-RFLP approach. The findings revealed that miR-202 rs12355840 polymorphism under codominant (CT and TT genotypes), dominant, recessive, overdominant, and also allelic models is correlated with increased risk of vitiligo. In addition, codominant, dominant, overdominant, as well as allelic models of miR-211 rs8039189 polymorphism decrease risk of vitiligo. No significant relationship was observed between the miR-1238 rs12973308 polymorphism and susceptibility to vitiligo. The miR-211 rs8039189 polymorphism may serve a protective effect on vitiligo development and miR-202 rs12355840 polymorphism may act as a risk factor for vitiligo susceptibility.

Albinism in the largest extant amphibian: A metabolic, endocrine, or immune problem?

BACKGROUND

Pigment regression is an intriguing phenomenon that can be caused by disorders in melanin metabolism or endocrine regulation, or by autoimmune disorders. Albino animals serve as excellent models for the study of the genetic determination of morphology, particularly the evolution of and molecular mechanisms underlying chromatophore-related diseases in animals and humans.

MATERIAL AND METHODS

The artificial culture of Andrias davidianus, the largest extant amphibian, is flourishing in China due to the great ecological and economic value of this animal. Approximately 0.1% of individuals express an albino phenotype accompanied by delayed somatic growth and mortality at early developmental stages. In this study, brain and skin transcriptomics were conducted to study the underlying molecular basis of the phenotype.

RESULTS

The results indicated decreased transcription of genes of melanin synthesis. Interestingly, MHC I isotypes and immune-related pathways accounted for the primary transcriptional differences between groups, suggesting that the albino phenotype represents a systematic immune problem to a far greater extent than a pigmentation defect. Albino individuals exhibited shifted transcription of MHC I isotypes, and the albino-specific isotype was characterized by increased charges and decreased space in the antigen- binding pocket, implying a drastic change in antigen specificity and a potential risk of autoimmune disorders.

CONCLUSION

These results suggest an association between the albino phenotype and MHC I variants in A. davidianus, which could serve as a convenient model for vitiligo or other autoimmune diseases.