Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.35 (matrix metalloproteinase 9)
 2,207 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Psoriasis is histologically characterized by hyperkeratosis and papillomatosis with elongated vessels in the upper dermis. In order to evaluate the role of gelatinases in remodelling psoriatic skin in this study we examined the production of the 72-kDa (gelatinase A), 92-kDa collagenase (gelatinase B) and their tissue inhibitors TIMP-2 and TIMP-1. A total of 19 patients affected by different types of psoriasis were included in this study. An immunohistochemical study on cryosections was performed using antibodies to 72-kDa gelatinase, 92-kDa gelatinase, TIMP-1, TIMP-2, laminin, collagen types I, III, IV, VII. mRNA expression for gelatinases and their inhibitors were also analyzed by reverse transcriptase polymerase chain reaction (RT-PCR). In 14 of 19 patients there was a positivity in 92-kDa protein expression in keratinocytes. The 92-kDa gelatinase protein was also present in the upper dermis with prevalence around blood vessels. In 15 of 19 patients the 72-kDa was localized in the upper dermis, almost exclusively in the papillary dermis but absent in epidermis. TIMP-1 and TIMP-2 were both negative in all cases in immunoperoxidase and RT-PCR. Using RT-PCR we show that the 72-kDa mRNA is expressed exclusively in the dermis, on the contrary the 92-kDa was present in epidermis and dermis. Type I, III, IV and VII collagens did not show any alteration or disruption. Overexpression and production of gelatinases without inhibitory effects suggest a role of these proteins in remodelling the psoriatic skin probably inducing the typical histological pattern of papillomatosis.
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PMID:The 72-kDa and the 92-kDa gelatinases, but not their inhibitors TIMP-1 and TIMP-2, are expressed in early psoriatic lesions. 941 21

Organ cultures were established from psoriatic lesional skin of 24 different individuals and maintained for 8 days under serum-free, growth-factor-free conditions. Nonlesional skin from 14 of the same individuals and normal skin from another 12 individuals were also maintained in organ culture. At the end of the incubation period, the tissues were fixed in formalin and examined histologically. Lesional skin continued to express features of psoriatic plaque, which included irregularly shaped epithelial cells arranged in a disorganized fashion, and elongation of the rete ridges with a thickening in their lower portion. Abnormal epidermal differentiation and separation of the upper epidermal layers from the lower layers was also a consistent feature. In contrast, nonlesional skin from psoriatic patients exhibited a histological appearance which resembled that of site-matched normal skin. When normal skin was exposed to a growth-factor-enriched culture medium during the 8-day incubation period, it exhibited a histological appearance similar to that of psoriatic skin. In addition to abnormal histological features, the psoriatic skin in organ culture released higher amounts of matrix metalloproteinase-9 (MMP-9; 92-kD gelatinase B/type IV collagenase) into the culture fluid than either nonlesional skin or normal skin. Organ cultures of psoriatic lesional skin from 6 individuals were maintained for 8 days in the presence of an antibody to the human epidermal growth-factor (EGF) receptor. The abnormal histological features of the psoriatic tissue were partially ameliorated in the presence of the antibody. These data suggest that growth factors which act through the EGF receptor help to maintain the psoriatic phenotype in organ culture. They also suggest that organ culture may provide a useful tool with which to elucidate the pathophysiological mechanisms of altered keratinocyte proliferation and differentiation in psoriasis.
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PMID:Human psoriatic skin in organ culture: comparison with normal skin exposed to exogenous growth factors and effects of an antibody to the EGF receptor. 976 71

In skin biology, matrix metalloproteinases (MMPs) have been implicated in inflammatory matrix remodeling, neovascularization, wound healing and malignant transformation. Psoriasis is histologically characterized by keratinocyte hyperproliferation, infiltration of inflammatory cells, neoangiogenesis and production of cytokines, such as TNF-alpha, IL-1beta, TGF-alpha, and IFN-gamma, also capable of regulating MMP transcription. To investigate the role of stromelysins-1 and -2, matrilysin, metalloelastase, collagenases-1 and -3 and 92-kDa gelatinase as well as their inhibitors, TIMPs-1 and -3, in psoriasis, we performed in situ hybridization using 35S-labeled cRNA probes on 29 psoriatic lesions and 9 samples of normal looking skin from psoriatic patients. Metalloelastase mRNA was detected in 21/27 samples in macrophages that had migrated into the epidermis or in the inflammatory infiltrates of the superficial dermis. A quantity of 92-kDa gelatinase was found in macrophages and neutrophils (25/27). Stromelysin-1 mRNA was detected in basal keratinocytes in 4/21 lesions. Intracellular laminin-5 immunosignal in basal keratinocytes of the same samples, suggested that stromelysin-1 might participate in remodeling of the basement membrane zone. No signal for stromelysin-2 or collagenase-3 was found and only sweat glands were positive for matrilysin. TIMP-1 was more abundantly expressed than TIMP-3 in the inflammatory infiltrates and endothelial cells of dermal papillae (22/29). TIMP-3 was expressed perivascularly in 9/16 samples. Our results suggest that overexpression of the investigated MMPs by keratinocytes is not associated with psoriasis. However, macrophages express MMPs in psoriatic skin. Also TIMPs, particularly TIMP-1, were abundantly expressed, suggesting that mere MMP overexpression is unlikely to contribute to psoriatic tissue changes.
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PMID:Metalloelastase (MMP-12) and 92-kDa gelatinase (MMP-9) as well as their inhibitors, TIMP-1 and -3, are expressed in psoriatic lesions. 1138 Jun 13