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Dingxin Recipe Ⅲ (DXR Ⅲ) is a traditional Chinese medicine compound used for hyperlipidemia treatment in clinical practice. However, its curative effects and pharmacological mechanisms in hyperlipidemia have not been clarified to date. Studies have demonstrated that gut barrier was strongly implicated in lipid deposition. Based on gut barrier and lipid metabolism, this study examined the effects and molecular mechanisms of DXR Ⅲ in hyperlipidemia. The bioactive compounds of DXR Ⅲ were detected by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry, and its effects were evaluated in high-fat diet-fed rats. Specifically, the serum levels of lipids and hepatic enzymes were measured using the appropriate kits; colon and liver sections were obtained for histological analyses; gut microbiota and metabolites were analyzed by 16S rDNA sequencing and liquid chromatography-MS/MS; and the expression of genes and proteins was determined by real-time quantitative polymerase chain reaction and western blotting and immunohistochemistry, respectively. The pharmacological mechanisms of DXR Ⅲ were further explored by fecal microbiota transplantation and short-chain fatty acid (SCFAs)-based interventions. DXR Ⅲ treatment significantly downregulated serum lipid levels, mitigated hepatocyte steatosis and improved lipid metabolism. Moreover, DXR Ⅲ improved the gut barrier, specifically by improving the physical barrier in the colon, causing part composition changes in the gut microbiota, and increasing the serum SCFAs level. DXR Ⅲ also upregulated the expression of colon GPR43/GPR109A. Fecal microbiota transplantation from rats treated with DXR Ⅲ downregulated part hyperlipidemia-related phenotypes, while the SCFAs intervention significantly improved most of the hyperlipidemia-related phenotypes and upregulated the expression of GPR43. Moreover, both DXR Ⅲ and SCFAs upregulated the expression of colon ABCA1. DXR Ⅲ protects against hyperlipidemia by improving the gut barrier, particularly the SCFAs/GPR43 pathway. [Display omitted] • This study examined the effects of Dingxin Recipe Ⅲ in hyperlipidemia based on gut barrier and lipid metabolism. • Mechanisms of Dingxin Recipe Ⅲ were explored by fecal microbiota transplantation and short chain fatty acid intervention. • Dingxin Recipe Ⅲ improved HFD-induced hyperlipidemia and gut barrier, including physical barrier, gut microbiota, and SCFAs. • Dingxin Recipe Ⅲ protects against hyperlipidemia by improving the gut barrier, particularly the SCFAs/GPR43 pathway. [ABSTRACT FROM AUTHOR]

Abstract: It is well known that neurons in the CA3 and dentate gyrus (DG) subfields of the hippocampus are resistant to short period of ischemia which is usually lethal to pyramidal neurons in hippocampal CA1 subfield. The present study was undertaken to clarify whether the inherent higher resistance of neurons in CA3 and DG to ischemia is associated with glial glutamate transporter-1 (GLT-1) in rats. Western blot analysis and immunohistochemistry assay showed that the basal expressions of GLT-1 in both CA3 and DG were much higher than that in CA1 subfield. Mild global brain ischemia for 8min induced delayed death of almost all CA1 pyramidal neurons and marked GLT-1 down-regulation in the CA1 subfield, but it was not lethal to the neurons in either CA3 or DG and induced GLT-1 up-regulation and astrocyte activation showed normal soma and aplenty slender processes in the both areas. When the global brain ischemia was prolonged to 25min, neuronal death was clearly observed in CA3 and DG accompanied with down-regulation of GLT-1 expression and abnormal astrocytes represented with hypertrophic somas, but shortened processes. After down-regulating of GLT-1 expression and function by its antisense oligodeoxynucleotides or inhibiting GLT-1 function by dihydrokainate, an inhibitor of GLT-1, the mild global brain ischemia for 8min, which usually was not lethal to CA3 and DG neurons, induced the neuronal death in CA3 and DG subfields. Taken together, the higher expression of GLT-1 in the CA3 and DG contributes to their inherent resistance to ischemia. [Copyright &y& Elsevier]