Sec 18 Neurocutaneous and Psychocutaneous Skin Disease

Question 1

Mediates itch in atopic dermatitis; mAChR3 is probably involved in itch.

Answer 1

Acetylcholine (ACh)

Question 2

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

Answer 2

Calcitonin generelated peptide (CGRP)

Question 3

Involved in antinociception (peripheral and central), anti-fibrotic; anti-inflammatory (contact dermatitis); regulates cell growth, differentiation, apoptosis. Involved in thermoregulation.

Answer 3

Cannabinoids

Question 4

Induces release of histamine, cytokines, TNF-α, VEGF from mast cells. CRH-like immunoreactivity seen on sensory nerves (rat).

Answer 4

Corticotropinreleasing hormone (CRH) and proopiomelanocortin (POMC)

Question 5

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.

Answer 5

Cytokines

Question 6

Antipruritic in the periphery.

Answer 6

Endocannabinoids

Question 7

Induces burning itch. Degraded by chymase via ETA receptor activation.

Answer 7

Endothelins (ETs)

Question 8

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.

Answer 8

Short-term TRPV1 activation

Question 9

Role in sensory and keratinocyte function

Answer 9

TRPV3 and TRPV4

Question 10

Role in pain, hypernociception, vasoregulation, barrier functio

Answer 10

TRPA1

Question 11

Keratinocyte differentiation

Answer 11

TRPV6

Question 12

Mediates itch but not pain (histamine dependent and independent).

Answer 12

Gastrin-releasing peptide

Question 13

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.

Answer 13

Acetylcholine

Question 14

Involved in pain and hypernociception; neuronal cell death; involved in vasoregulation and immune response (cytokine release, cell adhesion molecules).

Answer 14

Adenosine, ATP

Question 15

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.

Answer 15

Catecholamine, noradrenaline

Question 16

Involved in sweating.

Answer 16

CGRP

Question 17

Inhibit inflammatory edema by reduction of microvascular blood flow via Gal3R.

Answer 17

Galanin and galaninlike peptides

Question 18

Mediation of skin edema, pruritus; upregulation of cell adhesion molecule expression on keratinocytes and endothelial cells; induction of release of IL-8, TNF-α, histamine, tryptase, leukotriene B 4 , prostaglandin D 2 ; regulation of sebaceous glands; involved in inflammatory pain, contact dermatitis, immunomodulation, tumorigenesis and metastasis.

Released by proteinase-activated receptor 2 (PAR-2) agonists.

Answer 18

Substance P

Question 19

Upregulation of keratinocyte nerve growth factor expression.

Answer 19

Neurokinin A

Question 20

Sweat secretion, vasodilation; proliferation, migration of keratinocytes; histamine release from mast cells. Downregulation of VPAC2 receptor in mast cells in atopic dermatitis.

Answer 20

Vasoactive intestinal peptide

Question 21

Vasodilatation, immunomodulation; effect on T cells and macrophages; modulation of mast cell function; inhibition of antigen-induced apoptosis of mature T lymphocytes; downregulation of proinflammatory cytokines and chemokines in T cells; upregulation of cytokines and cell adhesion molecules in dermal microvascular endothelial cells; nociception.

Answer 21

Pituitary adenylate cyclase-activating polypeptide

Question 22

Keratinocyte and endothelial cell proliferation; stimulation of cytokine production.

Increased CGRP nerves in atopic dermatitis and nummular eczema; released by PAR-2 stimulation.

Answer 22

Calcitonin generelated peptide (CGRP)

Question 23

Antagonism of effects of proinflammatory cytokines (IL-17α, IL-1β, IL-6, TNF-α, endotoxins); upregulation of IL-10; induction of release of histamine from mast cells; inhibition of nuclear factor κ B.

Thioredoxin regulates POMC genes.

MSH-induced exocytosis from melanosomes.

Melanocortin 1 receptor expressed on human keratinocytes. Antioxidative and cytoprotective.

Answer 23

Pro-opiomelanocortin (POMC)