Chitosan oligosaccharide alleviates renal fibrosis through reducing oxidative stress damage and regulating TGF-ß1/Smads pathway.

Renal fibrosis (RF) is the common pathway for a variety of chronic kidney diseases that progress to end-stage renal disease. Chitosan oligosaccharide (COS) has been identified as possessing many health functions. However, it is not clear whether COS can prevent RF. The purpose of this paper was to explore the action and mechanism of COS in alleviating RF. First, an acute unilateral ureteral obstruction operation (UUO) in male BALB/c mice was performed to induce RF, and COS or fosinopril (positive control drug) were administered for 7 consecutive days. Data from our experiments indicated that COS treatment can significantly alleviate kidney injury and decrease the levels of blood urea nitrogen (BUN) and serum creatinine (SCr) in the UUO mouse model. More importantly, our results show that COS can reduce collagen deposition and decrease the expression of fibrosis proteins, such as collagen IV, fibronectin, collagen I, α-smooth muscle actin (α-SMA) and E-cadherin, ameliorating experimental renal fibrosis in vivo. In addition, we also found that COS suppressed oxidative stress and inflammation in RF model mice. Further studies indicated that the mechanism by which COS alleviates renal fibrosis is closely related to the regulation of the TGF-ß1/Smad pathway. COS has a therapeutic effect on ameliorating renal fibrosis similar to that of the positive control drug fosinopril. Taken together, COS can alleviate renal fibrosis induced by UUO by reducing oxidative stress damage and regulating the TGF-ß1/Smad pathway.

Sulfated polysaccharide from Undaria pinnatifida stabilizes the atherosclerotic plaque via enhancing the dominance of the stabilizing components.

The purpose of this study was to investigate the stable effect and mechanism of sulfated polysaccharide from Undaria pinnatifida (SPUP) on atherosclerotic plaque. The results showed that atherosclerotic plaques in the ApoE-/- mice of high-fat diet model group increased significantly without drug intervention. The content of vulnerable components (lipid, inflammatory macrophage) increased significantly, and the content of stability components (smooth muscle cell, collagen) reduced significantly. However, it could find that atherosclerotic plaque areas were decreased in a dose-dependent manner after SPUP intervention. SPUP could enhance the dominance of the stability components in plaque, and reduce the content of vulnerable component. Furthermore, SPUP could significantly reduce the matrix metalloprotein-9 content in atherosclerotic plaque. These results suggested that SPUP could stabilize atherosclerotic plaque by enhancing the dominance of the stability components content, reducing the vulnerability components content, and lowering the vulnerability index value.

Anticancer activity of polysaccharide from Glehnia littoralis on human lung cancer cell line A549.

The purpose of this study was to investigate the anticancer activity of polysaccharide (PGL) from Glehnia littoralis on human lung cancer cell line A549. Based on MTT assay, the results suggested that PGL could significantly reduce A549 cells proliferation in a time- and dose-dependent manner. In addition, PGL displayed an inhibitory activity for the A549 cells migration in Transwell migration assay. The results from both flow cytometry analysis and Hochst 3342 staining of apoptotic cells indicated that PGL could promote apoptosis, and induce cycle arrest of A549 cells. Moreover, immunofluorescence assay elucidated PGL could also down-regulate expression of proliferating cell nuclear antigen (PCNA). Overall, these results showed that PGL exerts a strong anticancer action through inhibiting the A549 cells migration, proliferation and inducing cell apoptosis. It could be a new source of natural anticancer agent against lung cancer with potential value in supplements and medicine.

Role of AP-2alpha transcription factor in the regulation of synapsin II gene expression by dopamine D1 and D2 receptors.

Synapsins are a family of neuron-specific phosphoproteins involved in synaptic vesicle docking, synaptogenesis, and synaptic plasticity. Previous studies have reported an increase in synapsin II protein by dopaminergic agents in the striatum, medial prefrontal cortex, and nucleus accumbens. This study investigated the mechanistic pathway involved in synapsin II regulation by dopaminergic drugs using primary midbrain neurons to determine which of several transcription factors regulates synapsin II expression. Protein kinase A (PKA) participation in the signaling pathway was examined using selective PKA inhibitors, which reduced synapsin II expression in cell cultures while dopaminergic agents were unable to increase synapsin II in the presence of the PKA inhibitor. Transcription factor involvement was further investigated using separate cultures treated with antisense deoxyoligonucleotides (ADONs) against the following transcription factors: activating protein 2 alpha (AP-2alpha), early growth response factor 1 (EGR-1), or polyoma enhancer activator-3 (PEA-3). Selective knockdown of AP-2alpha by ADONs reduced synapsin II levels, whereas treatment with EGR-1 and PEA-3 ADONs did not affect synapsin II expression. Furthermore, dopaminergic agents were no longer able to influence synapsin II concentrations following AP-2alpha knockdown. Collectively, these results indicate that a cyclic adenosine-3',5'-monophosphate/PKA-dependent mechanism involving the AP-2alpha transcription factor is likely responsible for the increase in neuronal synapsin II following dopamine D1 receptor stimulation or dopamine D2 receptor inhibition.