ABSTRACT
OBJECTIVE@#To explore the role of salt-inducible kinase 2 (SIK2) in myocardial ischemia-reperfusion (IR) injury in rats.@*METHODS@#Fifteen male SD rats were randomized equally into sham operation group, myocardial IR model group, and SIK2 inhibitor group (in which the rats were treated with intravenous injection of 10 mg/kg bosutinib via the left femoral vein 24 h before modeling). Ultrasound was used to detect the cardiac function of the rats, and myocardial pathologies were observed with HE staining. Transmission electron microscopy was used to observe autophagy of myocardial cells, and Western blotting was performed to detect the contents of the autophagy-related proteins SIK2, LC3B, Beclin-1, p62 and the expressions of p-mTOR, mTOR, p-ULK1, and ULK1 in myocardial tissue.@*RESULTS@#Myocardial IR injury significantly increased the number of autophagosomes (P < 0.05) and the expression of SIK2 protein (P < 0.01) in the myocardial tissues. Treatment with bosutinib before modeling obviously lowered the expression of SIK2 protein (P < 0.01), alleviated myocardial pathologies, and reduced the number of autophagosomes (P < 0.05) in the myocardial tissue. The rats with myocardial IR injury showed obviously lowered LVEF and FS values (P < 0.001), which were significantly improved by bosutinib treatment (P < 0.05); no significant difference was detected in IVSDd or LVPWDd among the 3 groups (P > 0.05). Myocardial IR injury obviously increased the expressions of LC3-II/LC3-I and Beclin-1 proteins and lowered the expression of p62 protein (P < 0.01), and these changes were significantly rescued by bosutinib treatment (P < 0.05). The rat models of myocardial IR injury showed significantly increased expression of p-ULK1 (Ser757) (P < 0.01) and lowered expression of p-mTOR protein (P < 0.0001) in the myocardium, and these changes were obviously reversed by bosutinib (P < 0.01 or 0.05); there was no significant difference in mTOR and ULK1 expressions among the 3 groups (P > 0.05).@*CONCLUSION@#SIK2 may promote autophagy through the mTOR/ULK1 signaling pathway, and inhibiting SIK2 can reduce abnormal autophagy and alleviate myocardial IR injury in rats.
Subject(s)
Animals , Male , Rats , Autophagy , Autophagy-Related Protein-1 Homolog/metabolism , Beclin-1/metabolism , Down-Regulation , Myocardial Reperfusion Injury , Protein Serine-Threonine Kinases , Rats, Sprague-Dawley , Signal Transduction , TOR Serine-Threonine Kinases/metabolismABSTRACT
In order to affirm the cardioactive components in Fuzi, we identified a group of aminoalcohol- diterpenoid alkaloids in Fuzi using ultra high-performance liquid chromatography coupled with electrospray ionization mass spectrometer (UPLC-ESI-MS) method. Among a total of forty-one isolated ingredients, thirteen major aminoalcohol-diterpenoid alkaloids were identified by comparing their retention times and MS spectra with those of the reference substances. Moreover, Fuzi samples from different places of origin and with different processing methods were examined and their components displayed a pattern of high similarity, though the relative abundance varies probably due to their different processing methods. Furthermore, the cardiac effect of each identified alkaloid was individually evaluated using the isolated bullfrog heart perfusion experiment. Among the thirteen aminoalcohol diterpenoid alkaloids tested, six of them significantly enhanced the amplitude rates. Taken together, we affirm that the cardioactive components in Fuzi are aminoalcohol-diterpenoid alkaloids, shedding light on future studies of the mechanisms and development of these cardioactive compounds.
Subject(s)
Animals , Aconitum , Chemistry , Alkaloids , Chemistry , Amino Alcohols , Chemistry , Cardiotonic Agents , Chemistry , Chromatography, High Pressure Liquid , Drugs, Chinese Herbal , Chemistry , Heart , In Vitro Techniques , Plant Extracts , Chemistry , Rana catesbeiana , Spectrometry, Mass, Electrospray IonizationABSTRACT
<p><b>AIM</b>To separate and quantitatively determine six alkaloids: aconitine, mesaconitine, hypaconitine, beiwutine, benzoylaconine and benzoylmesaconine in the Chinese traditional medicine Radix Aconiti Lateralis Preparata (Fuzi).</p><p><b>METHODS</b>A RP-ion-pair HPLC method was established. An AichromBond-1 C18 column was used at a column-temperature of 35 degrees C. The mobile phase was CH3CN5 mmol x L(-1) NaH2PO4(50:50) containing 7 mmol x L(-1) SDS at a flow-rate of 1.0 mL x min(-1). The detector was set at UV 235 nm.</p><p><b>RESULTS</b>These six alkaloids can be completely separated and determined quantitatively.</p><p><b>CONCLUSION</b>This method is accurate and suitable for the determination of six alkaloids in Fuzi.</p>