Metalloproteinase , activity culture

Expression of matrix metalloproteinases (MMPs) and their inhibitors is an important function of the RPE, particularly with respect to the maintenance of appropriate permeability of the Bruch s membrane (Ahir et al., 2002). This function can be tested in vitro (Marin-Castano et al., 2006). For example, it has been shown that the expression of MMP-2, TIPM-2s (tissue inhibitor of MMP-2), and type IV collagen by cultured ARPE-19 cells is affected by repetitive exposures to nonlethal oxidant injury with hydroquinone (Marin-Castano et al., 2006). Oxidative stress decreases MMP-2 activity and increases collagen type IV accumulation. 

Cultured cells secrete hyaluronidases into the culture media, away from the cells. Such a phenomenon does not occur within tissues. The production of unopposed hyaluronidase activity would cause great havoc in tissues. Simultaneous deposition of hyaluronidases and their inhibitors is a reasonable scenario, one that parallels control of the matrix metalloproteinases by their TIMPs (tissue inhibitors of MMPs). 

Tetracycline and doxycycline are metalloproteinase inhibitors and when given orally can block the action of corneal collagenases. Either may be effective for resolving noninfected corneal ulcers or corneal melting in which progressive necrosis of stromal tissue occurs despite the absence of a positive culture. Similarly, the anticollagenolytic activity of tetracycline or doxycycline can prove clinically useful in treating persistent corneal epithelial defects. 

In addition to the metal interactions with APP and Ab that may directly affect the generation of Ab and its aggregation and toxicity, biometals have been found to interact with many of the proteins and activities that surround APP. These interactions are hkely to subserve physiological purposes, and may reflect a role for APP metabolism in metal homeostasis. Zn has been shown to interact with and inhibit the gamma-secretase complex [ 172]. The intracellular carboxyl terminus of APP interacts with XIla (MINT), which in turn interacts with the Cu Chaperone of SODl (CCSl) directing Cu away from SODl [173]. CCSl interacts with a Cu(I)-binding site on the intracellular carboxyl terminus of BACEl [174], although it is not yet clear whether this influences BACE activity. This may be part of the mechanism by which Cu added to cell culture increases Ab release into the culture medium (unpublished data). A metalloproteinase inhibitory domain has been identified in the portion of APP immediately upstream from the Ab domain [175]. 

Inoue, N., Takeshita, S., Gao, D., Ishida, T., Kawashima, S., Akita, H., Tawa, R., Sakurai, H., and Yokoyama, M., Lysophosphatidylcholine increases the secretion of matrix metalloproteinase 2 through the activation of NADH/NADPH oxidase in cultured aortic endothelial cells. Atherosclerosis, 155, 45-52,2001. 

The effect of resveratrol on the expressions of matrix metalloproteinase and tissue inhibitors of metalloproteinase in cervical cancer HeLa cells was investigated [78]. The effect of resveratrol on the invasive ability of HeLa cells was observed with a transwell cell culture chamber. Activities of MM P-2 and MMP-9 were analyzed using gelatin zymog. Activities of TIMP-1 and TIMP-2 were analyzed using reverse zymog. mRNA expressions of MMP-2, MMP-9, TIMP-1, and TIMP-2 in HeLa cells were detected by RT-PCR. Their protein expressions were detected by Western blotting. Activities of MMP-2 and MMP-9 were found to be markedly... 

Rheumatoid arthritis synovial fibroblasts (RASFs) are known to produce matrix metalloproteinases (MMPs) and cause joint destruction. 10-HDA tested how to inhibit the activities of MMPs with RASFs isolated from rheumatoid tissues by enzymatic digestion, cultures in monolayers were treated with 10-HDA (0.5, 1, and 2mM). The molecular investigation revealed that... 

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