Cathepsin B a Potential Novel Marker of Itch in Psoriasis

According to a study published in Cells, cathepsin B could serve as a common indicator of the mast cell-dependent itch signature in psoriasis.

Researchers aimed to unravel the specific contributions of mast cells (MCs) to the cutaneous neuroinflammatory response in psoriasis. They examined MC density, distribution, their relationship with nerve fibers, disease severity, and molecular signatures by comparing MCs isolated from the skin of patients with psoriasis and healthy individuals using RNA-seq analysis.

In psoriatic skin, MCs were found to be closely associated with calcitonin gene-related peptide (CGRP)-positive nerve fibers, and both MC and nerve fiber density increased with disease severity. Gene expression analysis highlighted significant representation of neuron-related pathways in psoriatic skin, indicating the involvement of MCs in neuronal development and supporting evidence of their close interaction with nerve fibers. Furthermore, the study identified upregulated genes in MCs from psoriasis-involved skin, including CTSB, TLR4, and TACR1, all of which are associated with itch. CTSB emerged as a reliable indicator of psoriasis, as it was consistently elevated in both whole-skin datasets and isolated MCs. The density of cathepsin B+ cells, a marker for MCs, correlated with disease severity, strengthening the link between MCs and psoriasis-related itch.

“Our study provides evidence that cathepsin B could serve as a common indicator of the MC-dependent itch signature in psoriasis,” the authors concluded.

Reference
West PW, Tontini C, Atmoko H, et al. Human mast cells upregulate cathepsin B, a novel marker of itch in psoriasis. Cells. 2023;12(17):2177. doi:10.3390/cells12172177