cholecystokinin and Psoriasis

Topics: Antibodies, Monoclonal, Humanized; Cholecystokinin; Humans; Keratinocytes; Psoriasis; Severity of Illness Index; Treatment Outcome

Cholecystokinin (CCK) is a peptide hormone that functions in digestive organs and the CNS. We previously showed that CCK downregulates peripheral pruritus by suppressing degranulation of mast cells. In this study, we demonstrated that CCK octapeptide (CCK8) was constitutively expressed in the epidermis of normal skin, whereas its expression was lost in acanthotic lesions of psoriasis. In contrast, CCKA receptor (CCKAR), a high-affinity receptor for CCK, was constitutively expressed in the epidermis of psoriatic skin lesions. Expression of CCK was also reduced in skin lesions of an imiquimod (IMQ)-induced psoriatic mouse model. Notably, the expression level of CCK inversely correlated with the severity of epidermal inflammation, raising the possibility that CCK from epidermal keratinocytes suppresses the psoriatic inflammation. To verify this hypothesis, we investigated the effects of sulfated CCK octapeptide (CCK8S) on the development of IMQ-induced psoriatic inflammation. i.p. injection of CCK8S suppressed the IMQ-induced psoriatic inflammation accompanied by reduced mRNA expression of IL-17, IL-22, and IL-6 but not of IL-23. The suppressive effect of CCK8S was completely restored by administration of CCKAR antagonist. In vitro studies showed that exogenous CCK8S suppressed IL-6 production in CCKAR-expressing cultured human keratinocytes, and blocking the endogenous CCK signaling with CCKAR antagonist markedly enhanced IL-6 production. When keratinocytes were stimulated with IL-17, the expression of endogenous CCK was significantly decreased. These findings suggest that CCK physiologically functions as a negative regulator of keratinocyte-based inflammation in an autocrine or paracrine manner, although decreased CCK may pathologically contribute to continuous and aggravated skin lesions such as psoriasis.

Topics: Animals; Autocrine Communication; Cholecystokinin; Down-Regulation; Epidermis; Female; Humans; Imiquimod; Inflammation; Interleukin-17; Interleukin-6; Keratinocytes; Male; Mice; Oligopeptides; Paracrine Communication; Psoriasis; Signal Transduction

A secretin-pancreozymin test was conducted with 43 gastroenterologically healthy children and 12 patients with subtotal atrophy of intestinal mucosa. While the pancreas enzymes were normal, the patients with coeliac disease reacted to the injection of the peptide hormones by producing a larger volume of secretion than did the control group. Despite the increased secretion there was at the same time a significantly higher concentration of bile acids in the duodenal juice. Analysis of the bile acid distribution indicated no deviation from the norm. There was, however, a striking discrepancy between the bile acid and the bilirubin excretion in the children with subtotal atrophy, whose bilirubin secretion, compared to that of the control group, was greatly reduced.

Topics: Adolescent; Atrophy; Bile Acids and Salts; Celiac Disease; Child; Child, Preschool; Cholecystokinin; Giardiasis; Humans; Ichthyosis; Infant; Intestinal Diseases; Intestinal Mucosa; Intestine, Small; Psoriasis; Secretin