Cholecystokinin and glucagon-like peptide-1 analogues regulate intestinal tight junction, inflammation, dopaminergic neurons and α-synuclein accumulation in the colon of two Parkinson's disease mouse models.

Parkinson's disease (PD) is the second most common neurodegenerative disease, and no treatment is available to stop its progression. Studies have shown that the colonic pathology of PD precedes that of the brain. The 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model and the human A53T α-synuclein (α-syn) transgenic PD mouse model show colonic pathology and intestinal dopaminergic neuronal damage, which is comparable to the intestinal pathology of PD. Cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1), which are brain-gut peptides, have neurotrophic and anti-inflammatory properties. Two GLP-1R agonists have already shown robust effects in phase II trials in PD patients. However, whether they have beneficial effects on colonic pathology in PD remains unclear. In this study, MPTP-treated mice and human A53T α-syn transgenic mice were intraperitoneally injected with a CCK analogue or Liraglutide, a GLP-1 analogue, once a day for 5 weeks. Levels of colonic epithelial tight junction proteins including occludin and zonula occludens-1 (ZO-1), inflammatory biomarkers including inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-α), brain-derived neurotrophic factor (BDNF), tyrosine hydroxylase (TH) and α-syn were analyzed. The results show that the CCK analogue and Liraglutide both restored the disruption of intestinal tight junction, reduced colonic inflammation, inhibited colonic dopaminergic neurons reduction and the accumulation of α-syn oligomers in the colon of both PD mice models. This study suggested that CCK or GLP-1 analogues could be beneficial to the improvement of leaky gut barrier, inflammation, dopaminergic neuron impairment and accumulation of α-syn in the colon of PD patients.

circ_0001588 Induces the Malignant Progression of Hepatocellular Carcinoma by Modulating miR-874/CDK4 Signaling.

Accumulating evidence indicates that circular RNAs (circRNAs) can interact with microRNAs to modulate gene expression in various cancers, including hepatocellular carcinoma (HCC). Although the significant role of circRNAs has been well documented in HCC, the complex mechanisms of circRNAs still need to be elucidated. Our current study is aimed at investigating the function of circ_0001588 in HCC, which was observed to significantly increase in HCC tissues and cells. We demonstrated that the knockdown of circ_0001588 resulted in repressed cell proliferation, migration, and invasion. In vivo studies using a nude mouse model showed that circ_0001588 downregulation reduced tumor size. Moreover, miR-874 was predicted as a target of circ_0001588. Using luciferase binding assays, we proved that circ_0001588 functions as a molecular ceRNA of miR-874 and that CDK4 acts as a downstream target of miR-874 in HCC. It was confirmed that overexpression of miR-874 decreased the proliferation, migration, and invasion triggered by the increase in circ_0001588. In summary, our results indicate that circ_0001588 acts as a ceRNA and promotes HCC progression by targeting the miR-874/CDK4 signaling pathway. Hence, we propose that circ_0001588 may be a promising target for HCC treatment.

Study on the distribution of active centers in novel low Ti-loading MgCl2-supported Ziegler-Natta catalyst.

Novel MgCl2-supported Ziegler-Natta (Z-N) catalysts prepared using a new one-pot ball milling method can effectively control the amounts of Ti-loading in the catalysts. Complex GPC data on polypropylene synthesized by these novel catalysts were analyzed using the method of fitting the molecular weight distribution (MWD) curves with a multiple Flory-Schulz function. It was found that multiple active centers exist in these novel catalysts. Detailed study of the effects of the Ti-loadings in the catalysts on the distribution of the active centers showed that the Ti-loadings in the novel MgCl2-supported Z-N catalysts might affect the proportion of each type of active centers; and might be the main factor responsible for the effect of the Ti-loadings on the microstructure, the molecular weight and molecular weight distribution width of the resultant polymer, the catalytic activity and polymerization kinetics.