Natural products as the calcium channel blockers for the treatment of arrhythmia: Advance and prospect.

Arrhythmia is one of the commonly heart diseases with observed abnormal heart-beat rhythm that caused by the obstacles of cardiac activity and conduction. The arrhythmic pathogenesis is complex and capricious and related with other cardiovascular diseases that may lead to heart failure and sudden death. In particular, calcium overload is recognized as the main reason causing arrhythmia through inducing apoptosis in cardiomyocytes. Moreover, calcium channel blockers have been widely used as the routine drugs for the treatment of arrhythmia, but the different arrhythmic complications and adverse effects limit their further applications and demand new drug discovery. Natural products have always been the rich minerals for the development of new drugs that could be employed as the versatile player for the discovery of safe and effective anti-arrhythmia drugs with new mechanisms. In this review, we summarized natural products with the activity against calcium signaling and the relevant mechanism of actions. We are expected to provide an inspiration for the pharmaceutical chemists to develop more potent calcium channel blockers for the treatment of arrhythmia.

Biocatalytic strategies for the production of ginsenosides using glycosidase: current state and perspectives.

Panax ginseng is a traditional Chinese medicine with significant pharmaceutical effects and broad application. Rare ginsenosides with high antitumor activities can be generated via oriented modification of their glycosyl moiety. For this purpose, suitable microorganisms and their enzymatic systems can be used. In this review, we address several issues associated with these systems. Under aerobic conditions, fungus biotransformation provides an efficient and inexpensive biotransformation process that can be easily scaled up. Considering the profound use of probiotics, wild strains generally recognized as safe have shown a potential through classical fermentation in food manufacturers of deglycosylated ginsenosides. Commonly applied recombinant enzymes from E. coli, especially recombinant hyperthermophilic enzymes, showed efficient conversion in biomedical or pharmaceutical industries. In this review, key genes dedicated to the production of ginsenosides (especially in Saccharomyces cerevisiae) are highlighted in relation to the large-scale production of ginsenosides. We also evaluate biocatalytic strategies that are aimed to improve product specificity and biocatalytic efficiency with industrial applications. Perspectives of protein engineering and solvent engineering in the development and large-scale preparation of ginsenosides in anticancer drugs, food and health care products are explored. KEY POINTS : • Modification of ginsenosides with food/engineered microorganisms is summarized. • Optimization of cell factories by protein engineering remains challenging. • Solvent engineering offers an attractive potential alternative.

DDR2-CYR61-MMP1 Signaling Pathway Promotes Bone Erosion in Rheumatoid Arthritis Through Regulating Migration and Invasion of Fibroblast-Like Synoviocytes.

Regulation of matrix metalloproteinases (MMPs) by collagen in the fibroblast-like synoviocytes (FLSs) plays a critical role in joint destruction in rheumatoid arthritis (RA). Our previous study indicated that discoidin receptor 2 (DDR2) mediated collagen upregulation of MMPs. However, the precise underlying mechanism remains unclear. We report here that CYR61, a secreted, extracellular matrix-associated signaling protein which is capable of regulating a broad range of cellular activities, including cell adhesion, migration, proliferation, and apoptosis, is significantly upregulated in collagen II-stimulated RA FLS. Further studies found that collagen II-activated phosphorylated-DDR2 induces CYR61 through activation of transcription factor activator protein 1 (AP-1). The elevated CYR61, in turn, accelerates MMP1 production via ETS1 (ETS proto-oncogene 1). In addition, CYR61 significantly promotes FLS invasion and migration. Blockade of CYR61 by an adenovirus expressing CYR61 shRNA (Ad-shCYR61) in vivo remarkably ameliorated the severity of arthritis, reduced inflammatory cytokine secretion, and attenuated bone erosion as detected by micro-computed tomography (µCT), in collagen-induced arthritis (CIA) rats. Taken together, we uncovered the Collagen II-DDR2-AP-1-CYR61-ETS1-MMP1 loop in RA FLS. In which, CYR61 acts as a hinge to promote cartilage damage through regulating FLS invasion, migration, and MMP1 production and the inflammatory cascade in RA. Thus, CYR61 may be a promising diagnostic and therapeutic target for RA treatment. © 2016 American Society for Bone and Mineral Research.