Probes for INS

Immunologically targeted therapies have revolutionized the treatment of inflammatory dermatoses, including atopic dermatitis and psoriasis. Although immunologic biomarkers hold great promise for personalized classification of skin disease and tailored therapy selection, there are no approved or widely used approaches for this in dermatology. This review summarizes the translational immunologic approaches to measuring treatment-relevant biomarkers in inflammatory skin conditions. Tape strip profiling, microneedle-based biomarker patches, molecular profiling from epidermal curettage, RNA in situ hybridization tissue staining, and single-cell RNA sequencing have been described. We discuss the advantages and limitations of each and open questions for the future of personalized medicine in inflammatory skin disease.

Psoriasis and sarcoidosis are inflammatory skin and systemic diseases that may share a similar immunopathogenesis involving a Th1 and/or Th17 polarized immune response. Although the coexistence of sarcoidosis and psoriasis in the same individuals has been reported, the potential association between these diseases at a population-level in the United States has not been evaluated. To evaluate this association, we performed a matched cross-sectional study in the All of Us research program database. In the multivariable analysis of 4932 psoriasis cases and 19,728 controls, sarcoidosis was found to be significantly associated with psoriasis (OR 2.37 [95% CI 1.73-3.23], p < 0.001). The relative strength of this association between psoriasis and sarcoidosis may be, in part, explained by overlapping immunopathogenesis and common genetic susceptibility of these diseases. Taken together, these observations underscore the need for screening psoriasis patients for development of new cardiopulmonary symptoms. Further research into the mechanism of this relationship and its implications is warranted.

Actinic keratosis (AK) is considered as precursor lesion of invasive squamous cell carcinoma. Molecular studies on AK are limited because of too small size of the biopsy specimen to obtain enough DNA or RNA.Twenty biopsy cases of AK, followed by second same-sited biopsies, were included. Ten cases were diagnosed with total regression (regression group), while the other 10 were diagnosed with invasive carcinoma (progression group) in the follow-up biopsies. Using digital spatial profiling (DSP) technology, whole-gene expression analysis defined by specific regions of interest was performed for all 20 cases. After the clinicopathological features were assessed, separate and integrated analyses of these features and gene expression patterns were performed using machine-learning technology. All analyses were performed on both lesion keratinocytes (KT) and infiltrated stromal lymphocytes (LC).Among the 18,667 genes assessed, 33 and 72 differentially expressed genes (DEGs) between the regression and progression groups were found in KT and LC respectively. The primary genes distinguishing the two groups were KRT10 for KT and CARD18 for LC. Clinicopathological features were weaker in risk stratification of AK progression than the gene expression patterns. Pathways associated with various cancers were upregulated in the progression group of KT, whereas the nucleotide-binding oligomerization domain (NOD)-like receptor signalling pathway was upregulated in the progression of LC.Gene expression patterns were effective for risk stratification of AK progression, and their distinguishing power was higher than that of clinicopathological features.

Fingerprints are complex and individually unique patterns in the skin. Established prenatally, the molecular and cellular mechanisms that guide fingerprint ridge formation and their intricate arrangements are unknown. Here we show that fingerprint ridges are epithelial structures that undergo a truncated hair follicle developmental program and fail to recruit a mesenchymal condensate. Their spatial pattern is established by a Turing reaction-diffusion system, based on signaling between EDAR, WNT, and antagonistic BMP pathways. These signals resolve epithelial growth into bands of focalized proliferation under a precociously differentiated suprabasal layer. Ridge formation occurs as a set of waves spreading from variable initiation sites defined by the local signaling environments and anatomical intricacies of the digit, with the propagation and meeting of these waves determining the type of pattern that forms. Relying on a dynamic patterning system triggered at spatially distinct sites generates the characteristic types and unending variation of human fingerprint patterns.