Armin Makki - Angiogenesis

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Armin Makki is a 2nd year student at the Faculty of Health at York University, currently completing a BSc. in Kinesiology and Health Sciences. Armin is spending the summer researching in Dr. Haas’s laboratory, where he is exploring in the field of Angiogenesis – capillary growth – and the enzymes and proteins which are involved in the process. Specifically, Armin is conducting experiments using Gelatin Zymography, a process used to quantify enzymes. Through this process, Armin hopes to learn more about the activity of a group of enzymes known as matrix metalloproteinases (MMPs), and their inhibitors, Tissue Inhibitor of Metalloproteinases (TIMPs). These proteins are thought to be involved in various physiological processes such as tumor growth and metastasis, and the progression of some inflammatory diseases. Further research involving these enzymes may lead to findings which could lead to improved diagnostic methods and treatments for diseases which alter the quantity or activity MMPs and their inhibitors.


Matrix Metalloproteinases (MMPs) are a family of enzymes which hydrolyze components in the Extracellular Matrix, and allow for angiogenesis to occur by maturation of Tip Cells. MMPs play roles in processes such as vascular remodeling, wound healing and embryogenesis. Tissue Inhibitors of Metalloproteinases (TIIMPs) are a group of enzymes which inhibit the proteolytic activity of MMPs. This project aimed to find differences in the amount of MMPs present in control mice, and mice with genotypes lacking the TIMP-1 gene. Treatment groups also included mice with ligated femoral arteries in order to decrease shear stress in blood vessels, a factor which has previously been shown to decrease MMPs, and mice treated with prazosin. The gastrocnemius muscle of Wildtype and Knockout mice was collected, and protein was extracted from these muscles. Gelatin Zymography was used to quantify the the amount of MMP-2 and MMP-9 present in these samples. This gel electrophoresis derived method allows for the direct quantification of MMPs, by allowing the enzymes to consume their gelatin substrate and quantifying bands in areas of the gel in which MMP activity took place. Reverse gelatin Zymography, a process which aims to quantify TIMPs, works in a similar manner. Both of these methods were employed in order to inspect differences between the MMP and TIMP activity. Results thus far have not shown significant differences between the MMP quantity or activity across the groups. Further experiments and findings may prove beneficial in finding new cascades which activate or deactivate the activity of MMPs and TIMPs. These pathways can provide insight regarding the interactions between MMPs and TIMPs, and the processes which disrupt enzyme activity during the progression of disease.