A case of angiokeratoma circumscriptum: immunolocalization of matrix metalloproteinase (MMP)-9

Unusual Genital Wart Lesions: A Case Series on Angiokeratoma of Fordyce

Angiokeratoma is a vascular cutaneous disorder that is generally asymptomatic and presents with multiple dark red to blue or black papules over the skin. The prevalence of angiokeratoma increases as the age increases and it is more common after third and fourth decades of life. There are different types of angiokeratoma which may be localized forms (angiokeratoma of Mibelli, angiokeratoma circumscriptum, solitary angiokeratoma, and angiokeratoma of the scrotum or vulva) or diffuse variant (angiokeratoma corporis diffusum). Here, we report a series of five rare cases of angiokeratoma of Fordyce, of which two cases had vulval involvement and one case showed lesions on unilateral scrotal wall which was unusual.

Angiokeratoma circumscriptum of the buccal mucosa: a case report and literature review

Angiokeratoma is a benign cutaneous lesion of the capillaries, presenting as dilated vessels in the upper part of the dermis. Although this disorder is classified into various types and has been occasionally reported in the skin of the scrotum or extremities, the involvement of the oral cavity mucosa has been rarely reported. The present study reports a case of angiokeratoma circumscriptum in the buccal mucosa. The expression of vascular endothelial growth factor (VEGF) and both of its receptors (VEGFR-1 and VEGFR-2) was demonstrated by immunohistochemistry in the endothelial cells lining the dilated vessels. The expression of VEGFR-2 was higher than that of VEGFR-1 in the endothelial cells in the lesion, indicating an increased rate of endothelial cell proliferation within the lesion. Interestingly, some of the endothelial cells co-expressed VEGF and its two receptors. These results suggest that endothelial cells in the pathologically dilated vessels possess VEGF autocrine growth activity involved in vasculogenesis and maintenance in angiokeratoma lesions. To our knowledge, this is the second report published on isolated oral angiokeratoma confined to the buccal mucosa and the first case report on angiokeratoma circumscriptum involving the buccal mucosa.

Angiokeratoma circumscriptum in a young male

A 20-year-old male presented with multiple eruptions on his right leg since birth; these bled and were painful on trivial trauma. Examination revealed dark brown, hyperkeratotic, indurated, verrucous linear plaques with irregular borders. Histopathological evidence of hyperkeratosis, acanthosis, and extensive vascular proliferation in papillary dermis confirmed clinical suspicion of angiokeratoma circumscriptum (AKC). Excision and skin grafting yielded a cosmetically favorable outcome. Angiokeratomas, first described by Mibeli in 1889, are a group of vascular ectasias involving the papillary dermis. Angiokeratomas are more common in males; however, AKC–the rarest of its five variants–exhibits a female preponderance (F:M:3:1). AKC is an extremely rare nevoid disorder, only 100 of its cases having been reported in the world literature until 2006. Herein, we have reported a typical case of AKC in a young male that was previously misdiagnosed, and the patient wrongly counseled about the likelihood of its spontaneous regression.

Suppression of matrix metalloproteinase-9 expression in undifferentiated, non-apoptotic keratinocytes is abrogated by the cleavage of poly(ADP-ribose) polymerase-1

Matrix metalloproteinase (MMP)-9, an enzyme that degrades the extracellular matrix, has been implicated as a key enzyme in the process of tissue remodeling. This study demonstrates the regulation of MMP-9 transcription through a gene regulatory element in its promoter (the KRE-M9 element). The KRE-M9-binding protein was purified and identified as poly(ADP-ribose) polymerase-1 (PARP-1), which inhibits the transcription of MMP-9 similar to involucrin. This regulation occurs in non-apoptotic keratinocytes using the distinctive culture conditions of high and low Ca(2+) levels. PARP cleavage, which occurs during apoptosis, results in de-repression of MMP-9 promoter activity. These data clarify a new role of PARP-1 and suggest a physiologically relevant connection between caspase activation and MMP-9 expression.

Induction of matrix metalloproteinase-9 secretion from human keratinocytes in culture by ultraviolet B irradiation

BACKGROUND

Matrix metalloproteinases (MMPs) are known as important enzymes involved in tissue metabolism. Among them, MMP-2 and MMP-9 are termed gelatinases, but their specific roles in vivo are still unknown, including their expression patterns following ultraviolet (UV) irradiation.

OBJECTIVE

To elucidate the effects of UV irradiation on the skin, we analyzed the expression of MMP-2 and MMP-9 by primary human keratinocytes in culture.

METHODS

We evaluated the enzymatic functions of MMP-2 and MMP-9 by gelatin-zymography, and of MMP-9 expression by immunofluorescence, using cultured keratinocytes after UV irradiation.

RESULTS

The secretion of MMP-2 (72 kDa) remained at low levels under all conditions examined. Although MMP-9 (92 kDa) secretion was not induced by UVA, it was stimulated by UVB irradiation in a dose-dependent manner. In addition, an enzyme-linked immunosorbent assay showed the tendency to increase for the involucrin expression following UVB exposure. Cell viability was decreased by UVB irradiation in contrast to the induction of MMP-9 and involucrin.

CONCLUSION

These results suggest that the induction of MMP-9 secretion is related to the inflammation including apoptosis of keratinocytes resulting from UVB irradiation.