The Inhibiting Effectκ-carrageenan Oligosaccharide On Activated Microglial Cells

To detect the inhibiting activity of K-carrageenan oligosaccharides (KOS) on over activated-microglia cell and the relationship between the sulfate group content and its immune regulation activity, KOS produced by our laboratory were de-sulfate group processed to obtaine the desulfated derivatives of K-carrageenan oligosaccharides (DKOS). The effect of KOS and DKOS on the morphology and viability of LPS-activated microglial cells were investigated firstly. MTT assay was used to determine the viability of microglia cell. Hematoxylin-eosin staining was used to detect the morphology of LPS activated microglial cells. The "scratch" migration assay was used to analyse the effect of KOS on LPS activated microglial cells. The effect of FITC-KOS on microglia cells was determined by flow cytometry and laser scanning confocal microscopy. Then, the effect of KOS on the releasing of NO/NO2-, TNF-a, IL-10and arginase by LPS-activated microglial cells were detected. At last RT-PCR assay was used to detect the transcription of TNF-a and Western Blot assay was used to detect the expression of P-C-Jun and P-JNK in LPS activated microglia cells.The results showed that after pretreated with KOS, the viability and relasing of inflammatory cytokines, such as NO/NO2-, TNF-a, IL-10and arginine enzymes of LPS activated microglial cells were inhibited, and this inhibiting effect was dose-related. Compared with that of KOS, the inhibiting effect of DKOS was weaker relatively. The result of flow cytometry and laser scanning confocal microscopy showed that KOS could pass through cell membrane into the nucleus. And there was competitive relationship between LPS and KOS. The results of RT-PCR and Western Blot showed that the inhibiting activity of KOS on the over-activated microglial cell was related with p-JNK signaling pathway. Above all, KOS had a protective effect on over-activated microglial cell, could inhibit the inflammatory injury of microglial cell induced by LPS, and this protective effect was closely related with the content of the sulfate group.