Ginsenoside Rb1 Ameliorates Autophagy of Hypoxia Cardiomyocytes from Neonatal Rats via AMP-Activated Protein Kinase Pathway / 中国结合医学杂志

OBJECTIVE@#To investigate whether ginsenoside-Rb1 (Gs-Rb1) improves the CoCl-induced autophagy of cardiomyocytes via upregulation of adenosine 5'-monophosphate-activated protein kinase (AMPK) pathway.@*METHODS@#Ventricles from 1- to 3-day-old Wistar rats were sequentially digested, separated and incubated in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum for 3 days followed by synchronization. Neonatal rat cardiomyocytes were randomly divided into 7 groups: control group (normal level oxygen), hypoxia group (500 μmol/L CoCl), Gs-Rb1 group (200 μmol/L Gs-Rb1 + 500 μmol/L CoCl), Ara A group (500 μmol/L Ara A + 500 μmol/L CoCl), Ara A+ Gs-Rb1 group (500 μmol/L Ara A + 200 μmol/L Gs-Rb1 + 500 μmol/L CoCl), AICAR group [1 mmol/L 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR) + 500 μmol/L CoCl], and AICAR+Gs-Rb1 group (1 mmol/L AICAR + 200 μmol/L Gs-Rb1 + 500 μmol/L CoCl). Cells were treated for 12 h and cell viability was determined by methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and cardiac troponin I (cTnI) levels were detected by enzyme-linked immunosorbent assay (ELISA). AMPK activity was assessed by 2',7'-dichlorofluorescein diacetate (DCFH-DA) ELISA assay. The protein expressions of Atg4B, Atg5, Atg6, Atg7, microtubule-associated protein 1A/1B-light chain 3 (LC3), P62, and active-cathepsin B were measured by Western blot.@*RESULTS@#Gs-Rb1 significantly improved the cell viability of hypoxia cardiomyocytes (P0.05). Gs-Rb1 significantly down-regulated P62 levels of hypoxic cardiomyocytes (P<0.05). The P62 levels of hypoxic cardiomyocytes were inhibited by Ara A (P<0.05) and were not affected by AICAR (P=0.871).@*CONCLUSION@#Gs-Rb1 may improve the viability of hypoxia cardiomyocytes by ameliorating cell autophagy via the upregulation of AMPK pathway.

Apelin-APJ effects of ginsenoside-Rb1 depending on hypoxia-induced factor 1α in hypoxia neonatal cardiomyocytes / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate whether ginsenoside-Rb1 (Gs-Rb1) inhibits the apoptosis of hypoxia cardiomyocytes by up-regulating apelin-APJ system and whether the system is affected by hypoxia-induced factor 1α (Hif-1α).</p><p><b>METHODS</b>Neonatal rat cardiomyocytes were randomly divided into 6 groups: a control group, a simple CoCl group, a simple Gs-Rb1 group, a CoCl and Gs-Rb1 hypoxia group, a CoCl and 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1) group, a CoCl and YC-1 group and a Gs-Rb1 group, in which YC-1 inhibits the synthesis and accelerates the degradation of Hif-1a. The concentration of CoCl, Gs-Rb1 and YC-1 was 500 μmol/L, 200 μmol/L and 5 μmol/L, respectively; the apoptosis ratio was analyzed with a flow cytometer; and apelin, APJ and Hif-1α were assayed with immunocytochemistry, Western blot assays and reverse transcription polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>(1) The anti-apoptosis effect of Gs-Rb1 on hypoxia cardiomyocytes was significantly inhibited by YC-1; (2) Hypoxia significantly up-graded the expression of mRNA and protein of apelin; this effect was further reinforced by Gs-Rb1 and significantly inhibited by YC-1; (3) Gs-Rb1 further strengthened the expression of APJ mRNA and APJ proteins once hypoxia occurred, which was significantly inhibited by YC-1; (4) Gs-Rb1 significantly increased the expression of Hif-1α, which was completely abolished by YC-1; (5) There was a negative relationship between AR and apelin (or APJ, including mRNA and protein), a positive correlation between apelin (or APJ) protein and Hif-1a protein, in hypoxia cardiomyocytes.</p><p><b>CONCLUSION</b>The apelin-APJ system plays an important role in the anti-apoptosis effect of Gs-Rb1 on hypoxia neonatal cardiomyocytes, which was partly adjusted by Hif-1α.</p>

Influence of hypoxia on apoptosis and glucose intake in bone marrow derived mesenchymal stem cells in rats / 中国实验血液学杂志

To investigate the effects of hypoxia on the apoptosis and glucose intake of mesenchymal stem cells (MSCs), MSCs derived from bone marrow of rats were incubated in the atmosphere of 1% O(2) for a series of time points and their glucose-intaking capacity, ultrastructural changes and apoptotic proportions were analyzed by (3)H-labeling assay, electron microscopy and flow cytometry, respectively. The results showed that the cultured cells took the fibroblast-like morphology and could be induced into osteoblasts and adipocytes under appropriate conditions. The proportions of apoptotic cells after hypoxia treatment for 1, 4 and 8 hours were 13.7 +/- 2.26%, 14.1 +/- 2.78% and 14.7 +/- 4.01%, respectively, all of which were significantly higher than that observed in normoxic counterparts (0.09 +/- 2.03%, p < 0.05). Also, cell death occurred after hypoxia treatment and the death rates were 3.11 +/- 2.14%, 4.72 +/- 2.05% and 4.91 +/- 3.72% for 1, 4 and 8 hours incubation respectively. Under hypoxia culture in vitro, cell membrane microvillus began to fall off and the mitochondrias became swelling at 1 hour, and the above changes increasingly aggravated along with hypoxia time prolongation. The (3)H-glucose intaking ratios of MSCs at different hypoxia time points significantly decreased than those in normoxic cells (p < 0.01). It is concluded that the acute hypoxia can induce down-regulation of glucose-intaking capacity, ultrastructural changes and apoptosis of MSCs.