Adiponectin as an inducer of decorin synthesis in cultured vascular smooth muscle cells.

AIMS: Adiponectin, which is an adipose-specific plasma protein, exhibits antiatherogenic activities. The purpose of the present study is to demonstrate that adiponectin regulates the synthesis of proteoglycans-macromolecules comprising a core protein and glycosaminoglycan side chains involved in atherosclerosis progression-in vascular smooth muscle cells. MAIN METHODS: In the present study, proteoglycans obtained from cultured, adiponectin-treated human coronary artery smooth muscle cells were characterized using biochemical techniques. KEY FINDINGS: The results indicated that adiponectin induces the synthesis of decorin-a small dermatan sulfate proteoglycan-in vascular smooth muscle cells. Furthermore, the length of dermatan sulfate chains of the decorin molecule appeared to remain unchanged, but the epimerization of glucuronic acid in the chains decreased. SIGNIFICANCE: Although the significance of the regulation of decorin synthesis in atherosclerosis progression by adiponectin remains to be determined, the present study demonstrates for the first time that adiponectin regulates proteoglycan synthesis in vascular smooth muscle cells.

[Proteoglycan as a key molecule in atherosclerosis progression: characteristics of the structure and regulation of the synthesis].

Proteoglycans are macromolecules comprising a core protein and one or more glycosaminoglycan side chains. The macromolecules particularly derived from vascular smooth muscle cells accumulate in atherosclerotic vascular wall and are involved in the progression of vascular lesions. However, the functions of proteoglycans depend on the type of core proteins and microstructure of glycosaminoglycan chains, suggesting importance of the regulation of proteoglycan synthesis in vascular smooth muscle cells. Although the regulation of glycosaminoglycan chain formation is not clear, core protein synthesis is regulated by growth factors/cytokines, mechanical strain, coagulation factors, and other factors. Recently, we found that adiponectin, an adipose-specific plasma protein that exhibits antiatherogenic activities, regulates proteoglycan synthesis in vascular smooth muscle cells.

New oxindole alkaloids and iridoid from Carolina jasmine (Gelsemium sempervirens Ait. f.).

Three new gelsedine-type oxindole alkaloids, GS-1, GS-2, and GS-3, and one new iridoid, GSIR-1, were isolated from the stems and leaves of cultivated Carolina jasmine (Gelsemium sempervirens AIT. f.) and their structures were determined by spectroscopic analysis.

Metabolite profiling of alkaloids and strictosidine synthase activity in camptothecin producing plants.

Camptothecin derivatives are clinically used anti-neoplastic alkaloids that biogenetically belong to monoterpenoid indole alkaloids. Camptothecin-related alkaloids from the methanol extracts of Ophiorrhiza pumila, Camptotheca acuminata and Nothapodytes foetida plants were profiled and identified using a reverse-phase high performance liquid chromatography coupled with on-line photodiode array detection and electrospray-ionization ion-trap mass spectrometry. A natural 10-glycosyloxy camptothecin, chaboside, was accumulated in tissues of O. pumila but not in C. acuminata and N. foetida. Anthraquinones regarded as phytoalexins were present in the extracts of hairy roots and calli but not in the differentiated plants of O. pumila. These findings demonstrated a remarkable difference in the constituents between the differentiated plants and the hairy roots or calli tissues. The activity of strictosidine synthase, a key enzyme of camptothecin biosynthesis, was detected in the protein extracts of stems and roots of O. pumila, being correlated with the pattern of strictosidine synthase mRNA expression.