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Bhardwaj MicroRNAs in atopic dermatitis

Table 1: MicroRNA expression and functions in atopic dermatitis
MicroRNA Expression and functions
miR-155 One of the most upregulated microRNAs in AD lesions, primarily expressed in infiltrating T H cells, downregulates CTLA-
4, enhances T H cell proliferation, promotes T H 1 differentiation
miR-146a Increased expression in keratinocytes and chronic lesional skin in AD, inhibits expression of proinflammatory factors
including IFN-g-inducible genes and AD-associated genes CCL5, CCL8 and UBD, suppresses NF-kB signaling
pathway by targeting IRAK1, TRAF6, RELB, CARD10, decreases allergic skin inflammation
miR-203 Keratinocyte-specific, promotes epidermal differentiation, targets p63 which is a regulator of stem-cell maintenance,
increased levels in serum, decreased levels in urine of children with AD
miR-483-5p Increased levels in serum of children with AD, associated with rhinitis and/or asthma
AD: atopic dermatitis; UBD: ubiquitin D; IFN-g: interferon-g; CCL: chemokine ligand; NF-kB: nuclear factor kappa B

contrary, the expression of miR-125b was decreased gene expression regulators could potentially be used
significantly in both psoriasis and AD [26] . Another as personalized therapeutics in the near future.
interesting observation in that study was that miR-
203 was expressed more than 100-fold higher in skin DECLARATIONS
compared to other organs, including esophagus and
cervix that contain squamous epithelium. However, Authors’ contributions
mature forms of miR-146a, miR-21 and miR-125b were N. Bhardwaj contributed solely to the paper.
detectable in all studied organs. A synopsis of the
major miRNA players in atopic dermatitis is provided Financial support and sponsorship
in Table 1. None.

Since their discovery in mammalian cells approximately Conflicts of interest
10 years ago, the role of miRNAs in immune system There are no conflicts of interest.
has been extensively studied. MiRNAs can be
detected in different cell-free body fluids, such as Patient consent
serum, plasma, urine and saliva. This obviously raises Not applicable.
the question whether serum miRNAs can be used as
biomarkers of disease. Numerous studies have shown Ethics approval
that miRNAs can be used as diagnostic as well as Not applicable.
prognostic markers in various cancers, tissue injury
and inflammation. The connection between miRNAs
and allergic inflammatory conditions such as asthma, REFERENCES
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20 Journal of Translational Genetics and Genomics ¦ Volume 1 ¦ November 17, 2017