Sec 18 Neurocutaneous and Psychocutaneous Skin Disease Flashcards
Mediates itch in atopic dermatitis; mAChR3 is probably involved in itch.
Acetylcholine (ACh)
Expressed on central terminals; sensitizes receptive endings. Associated with increased pain transmission, prolongation of itch latency after substance P injection (inhibitory effect on itching). Involved in itchy skin diseases. Regulates antigen presentation on Langerhans cells; involved in drug-induced adverse reactions, atopic dermatitis and contact dermatitis. Downregulates NF-κB
Calcitonin generelated peptide (CGRP)
Involved in antinociception (peripheral and central), anti-fibrotic; anti-inflammatory (contact dermatitis); regulates cell growth, differentiation, apoptosis. Involved in thermoregulation.
Cannabinoids
Induces release of histamine, cytokines, TNF-α, VEGF from mast cells. CRH-like immunoreactivity seen on sensory nerves (rat).
Corticotropinreleasing hormone (CRH) and proopiomelanocortin (POMC)
T cells release IL-31 during inflammation and activate monocytes and keratinocytes via the IL-31 receptor (IL-31R). IL-31R is upregulated in atopic dermatitis and prurigo.
Cytokines
Antipruritic in the periphery.
Endocannabinoids
Induces burning itch. Degraded by chymase via ETA receptor activation.
Endothelins (ETs)
Induces pain and itch, depletes neuropeptides from sensory neurons. Longterm antipruritic effect of TRPV1 agonists (e.g., capsaicin): Suspend interplay between sensory neurons and mast cells. Affects epidermal and hair follicle proliferation, differentiation, apoptosis, and cytokine release. Increased expression in epidermal keratinocytes of prurigo nodularis patients.
Short-term TRPV1 activation
Role in sensory and keratinocyte function
TRPV3 and TRPV4
Role in pain, hypernociception, vasoregulation, barrier functio
TRPA1
Keratinocyte differentiation
TRPV6
Mediates itch but not pain (histamine dependent and independent).
Gastrin-releasing peptide
Innervation of sweat glands and arteriovenous anastomoses; keratinocyte and lymphocyte differentiation, proliferation, adhesion, migration. α 7 -Nicotinergic receptor modulates keratinocyte function, modulates skin microcirculation; involved in atopic dermatitis.
Acetylcholine
Involved in pain and hypernociception; neuronal cell death; involved in vasoregulation and immune response (cytokine release, cell adhesion molecules).
Adenosine, ATP
Innervation of blood vessels, erector pili muscles; pain transmission; regulation of activity in natural killer cells and monocytes; induction of apoptosis in lymphocytes. Regulate dendritic cell function.
β-Adrenergic-induced inhibition of keratinocyte migration.
Catecholamine, noradrenaline