Collagenolytic Matrix Metalloproteinase Structure–Function Relationships: Insights From Molecular Dynamics Studies

Hydrated Collagen: Where Physical Chemistry, Medical Imaging, and Bioengineering Meet

It is well-known that collagen is the most abundant protein in the human body; however, what is not often appreciated is its fascinating physical chemistry and molecular physics. In this Perspective, we aim to expose some of the physicochemical phenomena associated with the hydration of collagen and to examine the role collagen's hydration water plays in determining its biological function as well as applications ranging from radiology to bioengineering. The main focus is on the Magic-Angle Effect, a phenomenon observed in Nuclear Magnetic Resonance (NMR) spectroscopy and Magnetic Resonance Imaging (MRI) of anisotropic collagenous tissues such as articular cartilage and tendon. While the effect has been known in NMR and MRI for decades, its exact molecular mechanism remains a topic of debate and continuing research in scientific literature. We survey some of the latest research aiming to develop a comprehensive molecular-level model of the Magic-Angle Effect. We also touch on other fields where understanding of collagen hydration is important, particularly nanomechanics and mechanobiology, biomaterials, and piezoelectric sensors.

Polymorphisms of matrix metalloproteinases affect the susceptibility of esophageal cancer: Evidence from 20412 subjects, systematic review and updated meta-analysis

BACKGROUND

The results of how matrix metalloproteinases (MMPs) polymorphisms affect esophageal cancer (EC) risk are not consistent, especially for MMP1,2,7 and 9. A meta-analysis focused on the impact of MMPs to digestive cancers, but not a precise analysis to EC, therefore, we designed the current study to make a clear understanding of the association between MMPs polymorphisms and EC.

METHODS

Up to March 2020, we searched several databases to find case-control cohorts concerned about the risk of MMPs polymorphisms to EC risk. Odds ratios with 95% confidence intervals under five genetic models to generate the risk predicted value. The Q test and I2 statistics are used to estimate heterogeneity. Sensitivity analysis, Egger test, and Begg's funnel plot were employed to assess the results. In-silico analysis was performed to study the association between the polymorphism and mRNA expression.

RESULTS

19 case-control studies were enrolled, including 8371 EC patients and 12041 health controls. We observed the increased risk in BA vs. AA and BB + BA vs. AA models of MMP1-rs1799750 polymorphism. The protective effectiveness of EC was found in the MMP2 rs243865 polymorphism in B vs. A, BA vs. AA, and BB + BA vs. AA models. Meanwhile, the risk effect was also observed in the MMP7 rs11568818 polymorphism in most genetic models. In the furthermore bioinformatics analysis, we found that MMP1, MMP3, MMP7, MMP9, MMP12, MMP13 all increased in the tumor tissues, and the genetic alteration in the polymorphisms could impact the mRNA expression of the above MMPs.

CONCLUSION

MMP1 rs1799705 and MMP7 rs1156818 polymorphisms will take part in the tumorigenesis of EC, while MMP2 rs243865 acts as a protective role to decrease the risk of EC.

Mechanism and Inhibition of Matrix Metalloproteinases

Matrix metalloproteinases hydrolyze proteins and glycoproteins forming the extracellular matrix, cytokines and growth factors released in the extracellular space, and membrane-bound receptors on the outer cell membrane. The pathological relevance of MMPs has prompted the structural and functional characterization of these enzymes and the development of synthetic inhibitors as possible drug candidates. Recent studies have provided a better understanding of the substrate preference of the different members of the family, and structural data on the mechanism by which these enzymes hydrolyze the substrates. Here, we report the recent advancements in the understanding of the mechanism of collagenolysis and elastolysis, and we discuss the perspectives of new therapeutic strategies for targeting MMPs.