Vasoactive intestinal peptide, whose receptor-mediated signalling may be defective in alopecia areata, provides protection from hair follicle immune privilege collapse.

BACKGROUND: Alopecia areata (AA) is an autoimmune disorder whose pathogenesis involves the collapse of the relative immune privilege (IP) of the hair follicle (HF). Given that vasoactive intestinal peptide (VIP) is an immunoinhibitory neuropeptide released by perifollicular sensory nerve fibres, which play a role in IP maintenance, it may modulate human HF-IP and thus be therapeutically relevant for AA. OBJECTIVES: To answer the following questions: Do human HFs express VIP receptors, and does their stimulation protect from or restore experimentally induced HF-IP collapse? Is VIP signalling defective in AA HFs? METHODS: Firstly, VIP and VIP receptor (VPAC1, VPAC2) expression in human scalp HFs and AA skin was assessed. In HF organ culture, we then explored whether VIP treatment can restore and/or protect from interferon-γ-induced HF-IP collapse, assessing the expression of the key IP markers by quantitative (immuno-)histomorphometry. RESULTS: Here we provide the first evidence that VIP receptors are expressed in the epithelium of healthy human HFs at the gene and protein level. Furthermore, VIP receptor protein expression, but not VIP(+) nerve fibres, is significantly downregulated in lesional hair bulbs of patients with AA, suggesting defects in VIP receptor-mediated signalling. Moreover, we show that VIP protects the HF from experimentally induced IP collapse in vitro, but does not fully restore it once collapsed. CONCLUSIONS: These pilot data suggest that insufficient VIP receptor-mediated signalling may contribute to impairing HF-IP in patients with AA, and that VIP is a promising candidate 'HF-IP guardian' that may be therapeutically exploited to inhibit the progression of AA lesions.

Increased erythrocyte aggregation in men with coronary artery disease and erectile dysfunction.

We studied the association between erythrocyte aggregation (EA) and erectile dysfunction (ED) in men with coronary artery disease (CAD). Men with CAD documented by coronary angiography filled the Sexual Health Inventory for Males questionnaire to detect ED and assess its severity. EA was evaluated by filming slides of blood smear. Low percentage of slide field covered by erythrocytes represented increased EA. Overall, 133 men with CAD, mean ages 62.4+/-12.2 years, were included: 100 (75.2%) with ED and 33 (24.8%) without ED. EA was increased among men with ED compared with men without ED (percentage of slide field covered by erythrocytes 66.7+/-14.7 vs 73.1+/-14.5%; P=0.03). After adjustment for age, diabetes mellitus, hemoglobin and hematocrit levels, EA was associated with ED severity (r=0.18; P=0.038). We conclude that EA is increased in men with CAD and ED. This finding may be relevant to the pathophysiology of ED in men with CAD.