جستجوی مقالات مرتبط با کلیدواژه « metalloproteases » در نشریات گروه « پزشکی »

Rotator Cuff Tear (RCT) is a multifactorial disease, but an important one is the increased collagen degradation that would lead to a higher chance of tear. MMP-8 is a protein that degrades type I collagen, and it is known that MMP-8 has a polymorphism in which a T allele in the gene promoter region increases its transcription activity. This study aims to investigate the association between MMP -8 polymorphism g.-799 C>T (rs11225394) and RCT. To do that, we collected DNA samples from buccal epithelial cells of 128 patients (separated into RCT group and control group in a proportion 1:1) and genotyped the DNA using PCR. The statistical analyses were done using the ARLEQUIN Version 2.0, and the data normality was tested with the Shapiro-Wilk test. The results showed a significantly higher frequency of T/T genotype in the test group (29% in the control group and 39% in the test group, p=0.0417), and that would represent a risk factor for increased collagen degradation. The MMP-8 g.-799 C>T (rs11225394) SNP was associated with RCT. With the description of a new risk factor, future research can be done to analyze how to prevent RCT or develop new treatment strategies since the disease's failure index is currently high. Level of evidence: II

The main goal of our study was to describe the transcription factor (NF-κβ), angiogenetic factor (VEGF), and remodeling markers (MMP-9 and TIMP-4) of the cholesteatoma tissue compared to control skin tissue. There are still uncertainties how transcription, angiogenetic and remodeling factors affect the cholesteatoma course. Eight cholesteatoma tissue specimens were retrieved from children, seven – from adults, seven skin controls – from cadavers. Obtained material immunohistochemically were stained for NF-κβ, MMP-9, TIMP-4, VEGF. Non-para metric statistic methods were used. A statistically significant higher numbers of NF-κβ and TIMP-4 immunoreactive cells in the cholesteatoma compared to control group. A very strong positive correlation between MMP-9 and TIMP-4 was seen in the patient group. A strong positive correlation - between MMP-9 in matrix and MMP-9, VEGF in perimatrix, between TIMP-4 in matrix and TIMP-4 in perimatrix, NF-κβ in the matrix and VEGF; between TIMP-4 in perimatrix and NF-κβ in the matrix. Correlation between MMP-9 and TIMP-4 suggests that TIMP-4 in cholesteatoma tissue intercorrelates to MMP-9. TIMP-4 likely regulates the development of cholesteatoma. Disbalance between MMPs and TIMPs affects NF-κβ and causes uncontrolled cell proliferation and immune response in this tumor. There is a lack of VEGF strong expression in cholesteatoma perimatrix.

All cells encounter various signals coming from the surrounding environment and they need to receive and respond to these signals in order to perform their functions. Cell surface receptors are responsible for signal transduction .Platelets are blood cells which perform several functions using diverse receptors. Platelet concentrate is one of the most consumed blood products. However, due to the short lifespan of the platelets and platelets damage during storage, we face shortage of platelet products. One of the damages that platelets undergo during storage is the loss of surface receptors. Since cell surface receptors are responsible for all cell functions, the loss of platelet receptors reduces the quality of platelet products. In this study, we reviewed the important receptors involved in platelet activation and their associated signaling pathways. We also looked at the platelet receptors that shed during storage and the causes of this incident. We found that GPIbα, P-selectin, CD40 and GPVI are platelet receptors that fall during platelet storage at room temperature. Considering that GPVI and GPIbα are the most important receptors which involved in platelet activation, their shedding can cause decrease in platelet activation after transfusion and decrease thrombus consistence. Shear stress and platelet contact with the container wall are among the mechanisms discussed in this process, but studies in this area have to be continued.

The global incidence of snakebite has become a major concern to the community. This study aimed to evaluate the effect of mango seed kernel methanol extract on metalloproteases in Carpet Viper (Echis ocellatus) venom.
Mango seed kernel methanolic extract was evaluated in vitro for its anti-venom activity and inhibition of metalloproteases of Carpet Viper's (Echis ocellatus) venom. Metalloprotease portion was partially purified from the venom of E. ocellatus with a yield of 71%, a purification fold of 2.63 and a specific activity of 19.00 µmol/min/mg protein.
The enzyme appeared as a band on SDS-PAGE with a molecular weight of 23 kDa. The kinetic properties of the enzyme showed a Km of 0.31 mg mL-1 and a Vmax of 9.09 µmol min-1. When the enzyme was incubated with the extract, kinetic studies revealed a mixed non-competitive pattern of inhibition with Km values of 0.56 and 1.11 mg mL-1 and Vmaxvalues of 6.67 and 4.17-µmol min-1 for 5% and 20% inhibitor concentrations, respectively. An estimated Ki value of 0.168 mg mL-1 was obtained from a secondary plot demonstrating that the extract had a high affinity for the partially purified enzyme; thus, could serve as an effective inhibitor.
Methanol extract of mango seed kernel has a high affinity for the partially purified enzyme, and it might provide an inexpensive and readily available alternative to sheep serum in the management of snakebite envenomation. Therefore, further in vivo studies are necessary to assess its effectiveness and safety.