Mibefradil Alleviates High-Glucose-induced Cardiac Hypertrophy by Inhibiting PI3K/Akt/mTOR-mediated Autophagy.

Cardiac hypertrophy causes heart failure and is associated with hyperglycemia in patients with diabetes mellitus. Mibefradil, which acts as a T-type calcium channel blocker, exerts beneficial effects in patients with heart failure. In this study, we explored the effects and mechanism of mibefradil on high-glucose-induced cardiac hypertrophy in H9c2 cells. H9c2 cells were incubated in a high-glucose medium and then treated with different concentrations of mibefradil in the presence or absence of the Akt inhibitor MK2206 or mTOR inhibitor rapamycin. Cell size was evaluated through immunofluorescence, and mRNA expression of cardiac hypertrophy markers (atrial natriuretic peptide, brain natriuretic peptide, and ß-myosin heavy chain) was assessed by using quantitative real-time polymerase chain reaction. Changes in the expression of p-PI3K, p-Akt, and p-mTOR were evaluated using Western blotting, and autophagosome formation was detected using transmission electron microscopy. Our results indicate that mibefradil reduced the size of H9c2 cells, decreased mRNA expression of atrial natriuretic peptide, brain natriuretic peptide, and ß-myosin heavy chain, and decreased the level of autophagic flux. However, MK2206 and rapamycin induced autophagy and reversed the effects of mibefradil on high-glucose-induced H9c2 cells. In conclusion, mibefradil ameliorated high-glucose-induced cardiac hypertrophy by activating the PI3K/Akt/mTOR pathway and inhibiting excessive autophagy. Our study shows that mibefradil can be used therapeutically to ameliorate cardiac hypertrophy in patients with diabetes mellitus.

Further sesquiterpenoids from Pittosporum qinlingense and their anti-inflammatory activity.

Four new sesquiterpenoid glycoside esters, Pitqinlingoside N-Q (1-4), together with eleven known metabolites (5-15), were isolated from 95% EtOH extract of the twigs, fruits and leaves of P. qinlingense. The structures of new compounds were elucidated on the basis of extensive spectroscopic analyses, including IR, UV, HRMS, NMR and electronic circular dichroism spectra. Unusal glycoside esters are characterized by the presence of polyacylated ß-D-fucopyranosyl and ß-d-glucopyranosyl units. Pitqinlingoside N (1), O (2), P (3), boscialin (5) and arvoside C (6) showed significant nitric oxide production inhibition in lipopolysaccharide (LPS)-induced BV-2 microglial cells with IC50 values ranging from 1.58 to 28.74 µM. Structure-activity relationships of the isolated compounds are discussed.

CWI pathway participated in vegetative growth and pathogenicity through a downstream effector AflRlm1 in Aspergillus flavus.

The cell wall is an essential dynamic structure for shielding fungus from environmental stress, and its synthesizing and remodeling are regulated by the cell wall integrity (CWI) pathway. Here, we explored the roles of a putative downstream effector AflRlm1 of CWI pathway in Aspergillus flavus. The results showed that AflRlm1 played a positive role in conidia production, sclerotium formation, aflatoxin biosynthesis, and pathogenicity. Furthermore, we provided evidence for the physical connection between AflRlm1 and AflSlt2 and determined the role of AflSlt2 in the phosphorylation of AflRlm1. Then, we discovered the importance of WSCs (cell wall integrity and stress response component) to the CWI signal and the process of AflRlm1 transferring to the nucleus after receiving the signal. Overall, this study clarified the transmission process of CWI signals and proves that the CWI pathway plays a key role in the development of A. flavus and the production of aflatoxin combined with transcriptome data analysis.

[Involvement of PI 3 K/Akt/mTOR Signaling in Protective Effects of Moxibustion for Premature Ovarian Failure in Rats].

OBJECTIVE: To study the protective effect of moxibustion for tripterygium-induced premature ovarian failure (POF) and its underlying mechanisms in rats. METHODS: Forty-five female SD rats were randomly divided into normal control, POF model and moxibustion groups (n＝15/group). The POF model was induced by intragastric administration of Triptolide (40 mg/kg), once daily for 6 weeks. From the 4th week after modeling, moxibustion was given at "Guanyuan" (CV 4) and bilateral "Sanyinjiao" (SP 6) for 10 min, once daily for 3 weeks. Pathological changes of ovary tissues were determined by hematoxylin-eosin (HE) staining. The serum estradiol (E2), luteinizing hormone (LH), follicle-stimulating hormone (FSH), interleukin-6 (IL-6) and interleukin-1 ß (IL-1 ß) contents were measured by enzyme-linked immunosorbent assay (ELISA). The expression levels of phosphatidyl inositol 3- kinase (PI 3 K), protein kinase B (Akt) and mammalian target of rapamycin (mTOR) proteins of the ovarian tissue were detected by Western blot. RESULTS: After modeling, HE staining showed that the numbers of ovarian follicles and follicular granulocytes and corpora luteum layers were decreased, and the number of corpora atretica was increased in the model group. The content of serum E2 was markedly decreased and those of serum LH, FSH, IL-6 and IL-1 ß were markedly increased in the model group (P<0.01), and the expression levels of ovarian p-PI 3 K, p-Akt and p-mTOR were markedly increased after modeling relevant to the control group (P<0.01). Following moxibustion, the pathological damage of ovarian tissue was improved, the contents of serum LH, FSH, IL-6, IL-1 ß, and the levels of p-PI 3 K, p-Akt and p-mTOR proteins in the ovarian tissue were significantly decreased (P<0.05, P<0.01), and the content of serum E2 was markedly increased (P<0.05) in comparison with the model group. CONCLUSION: Moxibustion can improve POF in POF rats, which may be related to its actions in inhibiting PI 3 K/Akt/mTOR signaling, down-regulating serum IL-6, IL-1 ß, and regulating serum hormones.