Mechanism of total flavonoids of Rhododendra simsii in alleviating ischemic brain injury / 中国中药杂志

This study explores the effect of total flavonoids of Rhododendra simsii(TFR) on middle cerebral artery occlusion(MCAO)-induced cerebral injury in rats and oxygen-glucose deprivation/reoxygenation(OGD/R) injury in PC12 cells and the underlying mechanism. The MCAO method was used to induce focal ischemic cerebral injury in rats. Male SD rats were randomized into sham group, model group, and TFR group. After MCAO, TFR(60 mg·kg~(-1)) was administered for 3 days. The content of tumor necrosis factor-α(TNF-α), interleukin-1(IL-1), and interleukin-6(IL-6) in serum was detected by enzyme-linked immunosorbent assay(ELISA). The pathological changes of brain tissue and cerebral infarction were observed based on hematoxylin and eosin(HE) staining and 2,3,5-triphenyltetrazolium chloride(TTC) staining. RT-qPCR and Western blot were used to detect the mRNA and protein levels of calcium release-activated calcium channel modulator 1(ORAI1), stromal interaction molecule 1(STIM1), stromal intera-ction molecule 2(STIM2), protein kinase B(PKB), and cysteinyl aspartate specific proteinase 3(caspase-3) in brain tissues. The OGD/R method was employed to induce injury in PC12 cells. Cells were randomized into the normal group, model group, gene silencing group, TFR(30 μg·mL~(-1)) group, and TFR(30 μg·mL~(-1))+gene overexpression plasmid group. Intracellular Ca~(2+) concentration and apoptosis rate of PC12 cells were measured by laser scanning confocal microscopy and flow cytometry. The effect of STIM-ORAI-regulated store-operated calcium entry(SOCE) pathway on TFR was explored based on gene silencing and gene overexpression techniques. The results showed that TFR significantly alleviated the histopathological damage of brains in MCAO rats after 3 days of admini-stration, reduced the contents of TNF-α, IL-1, and IL-6 in the serum, down-regulated the expression of ORAI1, STIM1, STIM2, and caspase-3 genes, and up-regulated the expression of PKB gene in brain tissues of MCAO rats. TFR significantly decreased OGD/R induced Ca~(2+) overload and apoptosis in PC12 cells. However, it induced TFR-like effect by ORAI1, STIM1 and STIM2 genes silencing. However, overexpression of these genes significantly blocked the effect of TFR in reducing Ca~(2+) overload and apoptosis in PC12 cells. In summary, in the early stage of focal cerebral ischemia-reperfusion injury and OGD/R-induced injury in PC12 cells TFR attenuates ischemic brain injury by inhibiting the STIM-ORAI-regulated SOCE pathway and reducing Ca~(2+) overload and inflammatory factor expression, and apoptosis.

Molecular mechanism of ligustilide attenuating OGD/R injury in PC12 cells by inhibiting ferroptosis / 中国中药杂志

The aim of this study is to explore the mechanism of ligustilide, the main active constituent of essential oils of traditional Chinese medicine Angelicae Sinensis Radix, on alleviating oxygen-glucose deprivation/reperfusion(OGD/R) injury in PC12 cells from the perspective of ferroptosis. OGD/R was induced in vitro, and 12 h after ligustilide addition during reperfusion, cell viability was detected by cell counting kit-8(CCK-8) assay. DCFH-DA staining was used to detect the level of intracellular reactive oxygen species(ROS). Western blot was employed to detect the expression of ferroptosis-related proteins, glutathione peroxidase 4(GPX4), transferrin receptor 1(TFR1), and solute carrier family 7 member 11(SLC7A11), and ferritinophagy-related proteins, nuclear receptor coactivator 4(NCOA4), ferritin heavy chain 1(FTH1), and microtubule-associated protein 1 light chain 3(LC3). The fluorescence intensity of LC3 protein was analyzed by immunofluorescence staining. The content of glutathione(GSH), malondialdehyde(MDA), and Fe was detected by chemiluminescent immunoassay. The effect of ligustilide on ferroptosis was observed by overexpression of NCOA4 gene. The results showed that ligustilide increased the viability of PC12 cells damaged by OGD/R, inhibited the release of ROS, reduced the content of Fe and MDA and the expression of TFR1, NCOA4, and LC3, and improved the content of GSH and the expression of GPX4, SLC7A11, and FTH1 compared with OGD/R group. After overexpression of the key protein NCOA4 in ferritinophagy, the inhibitory effect of ligustilide on ferroptosis was partially reversed, indicating that ligustilide may alleviate OGD/R injury of PC12 cells by blocking ferritinophagy and then inhibiting ferroptosis. The mechanism by which ligustilide reduced OGD/R injury in PC12 cells is that it suppressed the ferroptosis involved in ferritinophagy.

Protective effect against myocardial ischemia reperfusion injuries induced by hyperoside preconditioning and its relationship with PI3K/Akt signaling pathway in rats / 中国中药杂志

To investigate the protective effect of preconditioning with hyperoside ( Hyp) against myocardial ischemia-reperfusion injury (MIRI) in rats and the role of PI3K/Akt signaling pathway. MIRI was established by ligation of left anterior descending coronary artery for 30 min followed by reperfusion for 120 min in rats. Male SD rats were randomly divided into five groups: sham group,model group (MIRI),Hyp preconditioning group(Hyp), Hyp preconditioning + LY294002 (a PI3K/Akt signaling pathway inhibitor) group (Hyp + LY), and LY294002 group (LY). At the end of reperfusion, hemodynamic parameters were recorded as left ventricular systolic pressure (LVSP) , left ventricular end-diastolic pressure ( LVEDP) and maximal rate of increase and decrease of left ventricular pressure (± dP/dt(max)). Myocardial infaret size, the oxidative stress markers, myocardial enzymes indicators and inflammatory factors were also analyzed. The expressions of Akt, p-Akt, Bax and Bcl-2 proteins was detected by using Western blot method. The results showed that Hyp preconditioning remarkably improved cardiac constriction and relaxation function, reduced myocardial infarct size and enhanced the activities of oxidative stress markers about correlated to MIRI, such as superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GSH-Px) and decreased the contents of malondialdehyde (MDA) as compared with MIRI group. Simultaneouly, the levels of myocardial enzymes, i. e. creatine kinase ( CK) and creatine kinase MB isoenzyme (CK-MB), and inflammatory factors, for instance tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were decreased. Hyp pretreatment apparently restrained myocardial apoptosis as evidenced by decreasing the level of Bax expression, increasing the levels of phosphorylation of Akt and Bcl-2 expression. These effects were inhibited by LY294002, a blocker of PI3K/Akt signaling pathway. These findings indicated that the cardioprotection of Hyp preconditioning against MIRI may be related to activating PI3K/Akt signaling pathway, upregulating the expression of BCL-2 protein and down-regulating the expression of Bax protein.

Effects and mechanisms of hyperoside on vascular endothelium function in middle cerebral arteries of rats ex vivo / 中国中药杂志

To investigate the effects and potential mechanisms of hyperoside (Hyp) on the vascular endothelium function in middle cerebral artery (MCA) ex vivo in rats. Isolated arterial segments from MCAs of rats were used for surveying vasomotoricity in a pressurized chamber. Transmembrane potential was recorded by using glass microelectrodes to evaluate hyperpolarization. Hyp (1 x 10(-6)-1 x 10(-4) mol . L-1) was utilized to observe the effect on 1 x 10(-7) mol . L-1 U46619-preconstricted MCA in rats. The results showed that 1 x 10(-6)-1 x 10(-4) mol . L-1 Hyp significantly induced concentration-dependent vasodilatation and hyperpolarization, leading to the maximal diastolic ratio of (73. 2 ± 6. 1)% and maximal changes in membrane potentials of (-13. 2 ± 2. 2) mV. Hyp still elicited vasorelaxation and hyperpolarization by removal of endothelium in MCA of rat, which was notably attenuated as compared with vascular endothelium-intact group (P <0. 01). In the MCAs preconstricted by U46619 (1 x 10(-7) mol . L-1), Hyp (1 x 10(-6)-1 x 10(-4) mol . L-1) produced concentration-dependent vasorelaxation and hyperpolarizition that were partially attenuated by 3 x 10(-5) mol . L-1 L-NAME(a NOS inhibitor) plus 1 x 10(-5) mol . L-1 PGI2 ,(a synthetase inhibitor). The residual effects were further decreased by 1 x 10(-3) mol . L-1 TEA (an inhibitor of Ca2+-activated potassium channel) or 1 x 10(-5) mol . L-1 PPG (a blocker of endogenous H2S synthese-CSE). Similarly, 1 x 10(-5)-1 x 10(-3) mol . L-1 NaHS (a donor of exogenous H2S) or 1 x 10(-5)-1 x 10(-3) mol . L-1 L-Cys (the substrate of endogenous H2S synthesis) obviously evoked dose-dependent vasodilatation and hyperpolarization of MCA in rats. These findings indicated that Hyp may induce endothelium-dependent and endothelium-independent responses. And the endothelium-dependent vasodilatation may be related to the increases of endogenous H2S that has been promoted Hyp in the endotheliocyte of MCAs, and activated Kca and opening of Kca channels, resulting in the hyperpolarization of vascular smooth muscle cell membrane and subsequent reduction of Ca2+ influx and vasodilation.

Expression of CD123 and CD114 on the bone marrow cells of patients with myelodysplastic syndrome / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Recent studies have shown that interleukin-3 receptor alpha (CD123) is highly expressed on leukemia stem cells of patients with acute myeloid leukemia, and is correlated with tumor load and poor prognosis. The expression of CD123 may also be high in patients with myelodysplastic syndrome (MDS). In this study, the expression and clinical significance of CD123 and granulocyte colony stimulating factor (G-CSF) receptor (CD114) on the bone marrow cells of patients with MDS were investigated to explore the molecular marker of the malignant clone of MDS.</p><p><b>METHODS</b>Forty-two patients with MDS, who were diagnosed in the Hematological Department of General Hospital of Tianjin Medical University from 2008 to 2009, and twelve normal controls were enrolled in this study. Fluorescence activiated cell sorter (FACS) was used to measure the expression of CD123 on CD34(+)CD38(-) cells and CD114 on CD34(+) cells of the bone marrow of these patients and controls and the clinical significance was analyzed. The expression of CD114 on CD123(+)CD34(+)CD38(-) cells was further measured to explore the molecular marker of the malignant clone in MDS.</p><p><b>RESULTS</b>MDS patients displayed significantly higher proportion of CD34(+)CD38(-)/CD34(+) ((14.03 +/- 5.27)%) than normal controls ((7.70 +/- 4.36)%, P < 0.05). The expression rate of CD123(+)CD34(+)CD38(-)/CD34(+)CD38(-) was significantly higher in MDS patients ((48.39 +/- 28.15)%) than that in normal controls ((8.75 +/- 11.71)%, P < 0.01). The expression level of CD123 was significantly correlated with the proportion of bone marrow blasts (r = 0.457, P < 0.05). The expression rate of CD114(+)CD34(+)/CD34(+) was lower in MDS patients ((33.05 +/- 21.71)%) than that in normal controls ((38.99 +/- 19.07)%) but was not statistically significant (P > 0.05). The expression of CD114 on CD123(+)CD34(+)CD38(-) cells ((34.82 +/- 29.58)%) was significantly lower than that on CD123(-)CD34(+)CD38(-) cells ((53.48 +/- 27.41)%) of MDS patients (P < 0.05).</p><p><b>CONCLUSIONS</b>MDS patients displayed higher proportion of CD34(+)CD38(-)/CD34(+) than normal controls. CD123 was highly expressed in the bone marrow of the patients with MDS, significantly correlated with the proportion of bone marrow blasts, and thus might be the marker of MDS malignant clone. CD123(+)CD34(+)CD38(-) cells exhibited lower expression of G-CSF receptors, which might partly explain why MDS clone responds worse to G-CSF in vitro and in vivo.</p>