Molecular mechanism of green microalgae, Dunaliella salina, involved in attenuating balloon injury-induced neointimal formation

Management of oxidative stress by microalgae

The aim of this review is to provide an overview of the current research on oxidative stress in eukaryotic microalgae and the antioxidant compounds microalgae utilize to control oxidative stress. With the potential to exploit microalgae for the large-scale production of antioxidants, interest in how microalgae manage oxidative stress is growing. Microalgae can experience increased levels of oxidative stress and toxicity as a result of environmental conditions, metals, and chemicals. The defence mechanisms for microalgae include antioxidant enzymes such as superoxide dismutase, catalase, peroxidases, and glutathione reductase, as well as non-enzymatic antioxidant molecules such as phytochelatins, pigments, polysaccharides, and polyphenols. Discussed herein are the 3 areas the literature has focused on, including how conditions stress microalgae and how microalgae respond to oxidative stress by managing reactive oxygen species. The third area is how beneficial microalgae antioxidants are when administered to cancerous mammalian cells or to rodents experiencing oxidative stress.

Hispolon attenuates balloon-injured neointimal formation and modulates vascular smooth muscle cell migration via AKT and ERK phosphorylation

The pathological mechanism of restenosis is attributed primarily to excessive proliferation and migration of vascular smooth muscle cells (VSMC). The preventive effects of hispolon (1) on balloon injury-induced neointimal formation were investigated, and 1 showed potent activity in inhibiting fetal bovine serum-induced VSMC outgrowth. Hispolon (1) significantly inhibited VSMC migration, as shown by trans-well assays. Compound 1 decreased the expression and secretion of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). The expression of the endogenous inhibitors of these proteins, namely, tissue inhibitors of MMP (TIMP-1 and TIMP-2), increased. The inhibition by noncytotoxic doses of 1 of VSMC migration was through its negative regulatory effects on FAK phosphorylation, ERK1/2 phosphorylation, and PI3K/AKT. These results demonstrate that 1 can inhibit the migration of VSMC by reduced expression of MMP-9 through the suppression of the FAK signaling pathway and of the activity of PI3K/AKT. The data obtained suggest that 1 might block balloon injury-induced neointimal hyperplasia via the inhibition of VSMC proliferation and migration, without inducing apoptosis.

A Chinese herbal formula "Gan-Lu-Yin" suppresses vascular smooth muscle cell migration by inhibiting matrix metalloproteinase-2/9 through the PI3K/AKT and ERK signaling pathways

BACKGROUND

This study was to explore the effects of Gan-Lu-Yin (GLY) on the migration of vascular smooth muscle cells (VSMCs) induced by fetal bovine serum and on neointima formation in a rat model of carotid artery balloon injury.

METHODS

VSMCs were treated with different concentrations of GLY, and then analyzed with Flow cytometric analysis, zymography, transwell, and western blotting. SD rats received balloon-injury were analyzed with H&E staining.

RESULTS

Our results showed that GLY significantly decreased the thickness of neointima. The inhibition by non-cytoxic doses of GLY of VSMCs migration was through its negative regulatory effects on phosphorylated ERK1/2, PI3K/AKT, and FAK. The data showed that GLY can inhibit the migration of VSMCs cells, and might block injury-induced neointima hyperplasia via the inhibition of VSMCs migration, without inducing apoptosis.

CONCLUSIONS

These observations provide a mechanism of GLY in attenuating cell migration, thus as a potential intervention for restenosis.