Role of central PGE2 on sympathetic excitation in chronic heart failure / 中国病理生理杂志

AIM:To observe the effect of central prostaglandin E2(PGE2) on sympathetic activation in chronic heart failure (CHF) and to explore the underlying mechanism. METHODS:Male SD rats were subjected to coronary ar-tery ligation to induce heart failure (HF), and the intracerebroventricular infusion was performed by osmotic pump continu-ously. The rats in sham group and HF group were given artificial cerebrospinal fluid (0. 25 μL/h). The rats in HF plus treatment group was given celecoxib (CLB; 20 mg/h). After 4 weeks, the levels of PGE2 in cerebrospinal fluid ( CSF), the sympathetic nerve excitability and cardiac function were measured, and the changes of corticotropin-hormone releasing hormone ( CRH)-containing neurons activation and neurotransmitter contents in the hypothalamic paraventricular nucleus ( PVN) were also determined. RESULTS:Compared with the sham-operated rats, the HF rats had raised level of PGE2 in CSF, up-regulated renal sympathetic nerve activity and plasma norepinephrine, increased left ventricular end diastolic pres-sure, lung-to-body weight and right ventricular-to-body weight ratios, and decreased maximal increase and decreased rate of left ventricular pressure (P<0.05). In addition, the number of CRH positive neurons in PVN and the level of plasma ad-renocorticotropic hormone were higher in HF rats than those in sham-operated rats (P<0.05). After administration of CLB into the lateral ventricle of HF rats, the contents of PGE2 in CSF were significantly reduced, the number of activation CRH neurons in PVN was decreased, the excitability of sympathetic nerves was down-regulated and cardiac function was im-proved (P<0.05). Compared with the sham-operated rats, the content of glutamic acid in PVN of HF rats was increased, the content of γ-aminobutyric acid and the number of glutamate decarboxylase 67-positive neurons were decreased ( P<0.05). After the CLB was given, the above indexes were reversed (P<0.05). CONCLUSION:These findings indicate that in CHF, the increased central PGE2 may activate CRH-containing PVN neurons and contribute to the augmented sym-pathetic drive possibly by modulating the neurotransmitters within the PVN.

The action of PI3K/AKT during genistein promoting the activity of eNOS / 中华心血管病杂志

<p><b>OBJECTIVE</b>Genistein could inhibit the development of atherosclerosis. This study explored the role of PI3K/AKT signaling during genistein promoted eNOS activation.</p><p><b>METHODS</b>Human umbilical vein endothelial cells (HUVECs) were incubated with ox-LDL (100 mg/L), then treated with genistein (100 nmol/L) for 5, 10, 15, 30 and 60 min. The production of NO was assessed by Griess reaction in cell culture supernatant. The mRNA expression of endothelial nitric oxide synthase (eNOS) was detected by reverse transcription-polymerase chain reaction (RT-PCR). The protein expression of eNOS and phosphorylation eNOS(Ser(1179)) were determined by Western blot. The effect of genistein on phosphorylation eNOS(Ser(1179)) level was also observed in the presence of LY294002 or NSC154020 (PI3K and AKT inhibitors).</p><p><b>RESULTS</b>The concentration of NO and the expression level of phosphorylation eNOS(Ser(1179)) were significantly increased in ox-LDL + genistein treated cells than ox-LDL treated cells (all P < 0.05), and the peak effects were observed at 15 min, however, eNOS mRNA and non-phosphorylated eNOS protein expression were similar between the two groups (P > 0.05). Furthermore, the expression level of phosphorylation eNOS(Ser(1179)) was significantly lower in PIK3/AKT inhibitors LY294002 and NSC154020 treated cells compared with ox-LDL + genistein treated cells (all P < 0.05).</p><p><b>CONCLUSION</b>Genistein could promote the activity of eNOS through increasing phosphorylation eNOS(Ser(1179)) level through PI3K/AKT pathway.</p>

Prophylactic effect of TLR5 agonist flagellin on acute graft versus host disease after allogeneic hematopoietic stem cell transplantation and its mechanism / 中国实验血液学杂志

This study was aimed to investigate the prophylactic effect of Toll like receptor (TLR)5 agonist flagellin on acute graft versus host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and its possible mechanism. The animal model with allo-HSCT aGVHD was established by using purebred mice (male mouse C57BL/6 as donor, female mouse BALB/c as recipient) with complete-unidentical major histocompatibility antigen. The recipient mice were randomly divided into 3 groups: group 1 in which mice were injected with high purity (95%) flagellin before and after allo-HSCT respectively, group 2 in which mice received allo-HSCT without injection of flagellin, group 3 in which mice were radiated alone. The aGVHD features of mice in group 1 and 2 were observed and compared. The results showed that the typical symptoms of aGVHD appeared in transplanted mice. The death peak of mice in group 2 appeared at day 4-5 after transplantation. The aGVHD symptoms were obviously alleviated and the mean survival time was prolonged significantly in mice group 1 as compared with mice in group 2 (P < 0.05). The comparison of WBC count in peripheral blood of mice in 3 groups before transplantation showed no significant difference (P > 0.05), while WBC count of mice in group 1 and 2 showed the significant difference at days 14 and 21 after transplantation (P < 0.05). The pathological appearances of aGVHD in mice of group 1 were obviously reduced as compared with mice in group 2. The flow cytometric detection of Treg cell/CD4(+) T cell levels at different time before and after transplantation demonstrated that the Treg cell level in mice of group 1 at weeks 2-4 after transplantation significantly increased as compared with mice in group 2 (P < 0.05). It is concluded that flagellin can effectively prevent the aGVHD occurrence after allo-HSCT, reduce the symptoms and pathological changes of aGVHD, obviously prolong mean survival time of mice in group 1. The mechanism of flagellin effect may be associated to increase of Treg cell level in mice after allo-HSCT.

Silencing of ICSBP/IRF8 expression in U226 cells and bone marrow mononuclear cells from patients with multiple myeloma / 中国实验血液学杂志

The objective of this study was to investigate expression of interferon regulatory factors (ICSBP/IRF8) and the potential role of DNA methylation in silencing ICSBP/IRF8 gene in multiple myeloma (MM) cell line U266 and bone marrow mononuclear cells from 10 MM patients (MM-BMMNC). The bone marrow mononuclear cells from 10 healthy persons (N-BMMNC) were collected and used as normal controls. Expression of ICSBP/IRF8 gene was detected by real-time fluorescence quantitative PCR (using 2(-ΔΔCT) to calculate); DNA methylation level of the ICSBP/IRF8 gene was measured using methylation-specific PCR (using the ratio of interest gene ICSBP/IRF8 and internal reference β-actin expression as results). The results showed that as compared with N-BMMNC the lower expression of ICSBP/IRF8 gene was found in U266 cells and MM-BMMNC, the hypermethylation of the CpG island in the ICSBP/IRF8 promoter was observed, there were significant differences between N-BMMNC and MM-BMMNC or U266 cells (P < 0.05). It is concluded that the expression of ICSBP/IRF8 gene can be silenced in the MM-BMMNC and U226 cells. As the hypermethylation of CpG island in ICSBP/IRF8 promoter is a frequent event in MM cells, the ICSBP/IRF8 gene silencing caused by DNA methylation may take part in the pathogenesis and development of MM.

Effect of bortezomib on the drug sensitivity of imatinib resistant K562/G01 cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the effect of bortezomib (BOR) on the drug sensitivity of imatinib-resistant chronic myeloid leukemia cell line K562/G01 cell and its mechanism.</p><p><b>METHODS</b>MTT assay was used to detect the inhibition effect of cell growth, flow cytometry to cell cycle, and real time-PCR to the expression of COX-2 and mdr1 mRNA.</p><p><b>RESULTS</b>Combination of 10 and 20 nmol/L BOR with imatinib could significantly enhance the sensitivity of K562/G01 to imatinib, the reverse factor was 1.83 and 2.72-fold respectively. Cell cycle arrested at G(2)/M phase could be observed by flow cytometry on BOR treatment. The over-expression of COX-2 and mdr1 could be down-regulated by BOR.</p><p><b>CONCLUSIONS</b>BOR can enhance the imatinib sensitivity of imatinib resistant K562/G01 cell. The mechanism may be related to cell cycle phase arrested at G2/M and down-regulation of COX-2 and mdr1 expression.</p>

Substance P stimulates differentiation of mice osteoblast through up-regulating Osterix expression / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the molecular pathway of substance P (SP) to induce osteoblastic differentiation.</p><p><b>METHODS</b>Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups with Group A (control group) cultured without any factors, Group B cultured with SP, Group C cultured with SP and SP receptor neurokinin-1 (NK1) antagonist, and Group D cultured with SP NK1 antagonist respectively to induce osteoblastic cells differentiation. Osterix gene expression was detected by reverse transcription-polymerase chain reaction (RT-PCR) for three times after 1-2 weeks of cultivation and the results were analyzed by one-way analysis of variance (ANOVA).</p><p><b>RESULTS</b>The log phase of bone marrow stromal cells appeared at 4-6 days. ALP staining revealed that the majority of cells, more than 95%, were positive and small blue-purple granules were found in the cytoplasm. And Group B, treated with SP, showed a higher level of ALP activity than the other three groups. Meanwhile, RT-PCR found that Osterix expression in Group B was obviously up-regulated, compared with other groups. But Osterix expression in Group D had no remarkable differences, compared with the controls.</p><p><b>CONCLUSIONS</b>SP can up-regulate Osterix gene expression to stimulate differentiation of mesenchymal stem cells into osteoblastic cells at the final stage. The regulatory effect of SP on Osterix expression was dependant on SP NK1 receptors.</p>

Arsenic trioxide combined with buthionine sulfoximine enhances apoptosis in multidrug-resistant human leukemia K562/ADM cells in vitro / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the apoptosis-inhancing effect of the combination of arsenic trioxide (As2O3 ) and buthionine sulfoximine (BSO) on multidrug-resistant human leukemic K562/ADM cells, to compare the effect of As2O3 alone and As2O3 combined with BSO and As2O3 alone, and to determine the effect of intracellular GSH content on this treatment.</p><p><b>METHODS</b>As2O3 was used in a dose of 0.5 micromol/L, 2.0 micromol/L and 5.0 micromol/L, respectively, and BSO was used in a dose of 100 micromol/L in the culture of multidrug-resistant human leukenic K562/ADM cells. The cell proliferation activity was assessed with MTT assay. The cell apoptosis was detected by flow cytometry using Annexin-V and propidium iodide (PI) staining. Intracellular GSH content was measured using glutathione assay kit by spectrophotometry.</p><p><b>RESULTS</b>After the GSH contents were reduced by the combination of arsenic in clinic dose (0.5, 2 micromol/L) and BSO (100 micromol/L), respectively, the K562/ADM cell proliferation activity was obviously inhibited and the cell apoptosis-inducing effect was advanced in 24 hours. In 48 and 72 hours, the effect of the combination group (clinic dose arsenic group) was significantly stronger than that of clinic dose arsenic alone group and the high dose arsenic alone group.</p><p><b>CONCLUSION</b>The cell apoptosis-inducing effect of arsenic in combination of BSO on multidrug resistant human leukemia K562/ADM cells is significantly enhanced in comparison with that of arsenic alone. The reduction of intracellular glutathione content is closely correlated with this apoptosis-enhancing effect.</p>

The effect of arsenic trioxide (As2O3) combined with BSO on K562/ADM cell and its mechanisms / 中华血液学杂志

<p><b>OBJECTIVE</b>To investigate the apoptosis-induction, P-glycoprotein (P-gp) and mdr1 mRNA inhibition effects of arsenic trioxide (As2O3) and buthionine sulfoximine (BSO) on multidrug-resistant cell line K562/ADM cells, and to determine the relationship between intracellular GSH content and arsenic effect.</p><p><b>METHODS</b>K562/ADM cells were treated with arsenic (0.5, 2.0, 5.0 micromol/L) alone or combined with BSO (100 micromol/L). The cell proliferating capacity was assessed with MTT assay, and cell apoptosis by Annexin V and propidium iodide (PI) staining. Intracellular GSH contents were measured using a glutathione assay kit by spectrophotometry. P-gp expression was determined by flow cytometry, and mdr1 mRNA expression by semi-quantitative RT-PCR.</p><p><b>RESULTS</b>The GSH contents in K562/ADM cell was (81.13 +/- 3.91) mg/g protein. After the GSH contents were degraded by BSO, the K562/ADM cell proliferating capacity was obviously inhibited and the cells were induced apoptosis in 24 hours by the combination of clinic dose arsenic group (0.5, 2.0 micromol/L) and BSO (100 micromol/L). The cell apoptosis rates at 48 hours in arsenic alone group and combination group were (59.29 +/- 6.01)% and (65.06 +/- 8.29)%, and at 72 hours were (82.15 +/- 9.28)% and (92.72 +/- 9.41)% retrospectively. At 48 hours, the mdr1 mRNA inhibition effect of the combination group was obviously stronger than that of high dose arsenic alone group. At 72 hours, the P-gp inhibition effect of the combination group (clinic dose arsenic group, 0.5, 2.0 micromol/L) was obviously stronger than that of high dose arsenic alone group (5.0 micromol/L).</p><p><b>CONCLUSION</b>The intracellular GSH contents are closely correlated with the arsenic effect. The combination of conventional dose arsenic and BSO significantly induces K562/ADM cell apoptosis and inhibits P-gp and mdr1 mRNA expression in the cells.</p>