RESUMEN
Betulinic acid (BA) exerts protective effects on organs in septic animals. However, whether BA can improve cardiac function in sepsis and the underlying mechanism remain unclear. Here, male Sprague-Dawley rats were pretreated with BA (25 mg/ kg/ d, i. g.) for 5 days and then intraperitoneally injected with lipopolysaccharide (LPS, 10 mg/ kg). The rats were anesthetized to determine transthoracic echocardiography using a high-resolution imaging system for small animals after they were treated with LPS for 6 h. Histopathologic alterations were examined by HE staining. Myocardial injury markers (cTnI and CK-MB) and inflammatory factors (TNF-α, IL-1β and IL-6) in the serum were measured by the enzyme-linked immunosorbent assay. Autophagy-related proteins (p62 and LC3 Ⅱ) and AKT-modulated autophagy pathways in the myocardium were determined by Western blotting. Pretreatment with BA markedly improved left ventricular ejection fraction (EF) and fraction shortening (FS) (P<0. 05), improved myocardial histomorphology, and significantly inhibited cTnI, CK-MB, TNF-α, IL-1β and IL-6 (P<0. 05) in the septic rat serum. BA markedly decreased p62 (P<0. 01), increased LC3 Ⅱ (P< 0. 001), and significantly down-regulated p-AKT (Thr308), p-AMPKα (Ser485/ 491), p-mTOR (Ser2448) and p-S6K (Thr389) (P<0. 05), while markedly up-regulated p-AMPKα (Thr172) and pULK1 (Ser317) (P<0. 01) in septic rat hearts. The findings indicate that BA can attenuate sepsis-induced myocardial dysfunctions associated with down-regulating autophagy inhibiting pathways mediated by AKT/ mTOR and AKT/ AMPK pathways.
RESUMEN
In order to explore the functions of genes of key rate-limiting enzymes chalcone isomerase(CHI) and chalcone synthase(CHS) in the biosynthesis of flavonoids in Lonicera macranthoides, this study screened and cloned the cDNA sequences of CHI and CHS genes from the transcriptome data of conventional variety and 'Xianglei' of L. macranthoides. Online bioinformatics analysis software was used to analyze the characteristics of the encoded proteins, and quantitative reverse-transcription polymerase chain reaction(qRT-PCR) to detect the expression of CHI and CHS in different parts of the varieties at different flowering stages. The content of luteo-loside was determined by high performance liquid chromatography(HPLC) and the correlation with the expression of the two genes was analyzed. The results showed that the CHI and CHS of the two varieties contained a 627 bp and 1170 bp open reading frame(ORF), respectively, and the CHI protein and CHS protein were stable, hydrophilic, and non-secretory. qRT-PCR results demonstrated that CHI and CHS of the two varieties were differentially expressed in stems and leaves at different flowering stages, particularly the key stages. Based on HPLC data, luteoloside content was in negative correlation with the relative expression of the genes. Thus, CHI and CHS might regulate the accumulation of flavonoids in L. macranthoides, and the specific functions should be further studied. This study cloned CHI and CHS in L. macranthoides and analyzed their expression for the first time, which laid a basis for investigating the molecular mechanism of the differences in flavonoids such as luteoloside in L. macranthoides and variety breeding.