Effect and Mechanism of Cxcr4 Gene-Modified BMSC-Derived Exosomes on Aplastic Anemia / 中国实验血液学杂志

OBJECTIVE@#To explore the improvement effect of CXC chemokine receptor 4 (Cxcr4) gene-modified bone marrow mesenchymal stem cell (BMSC)-derived exosomes on aplastic anemia (AA), and make a preliminary exploration of the mechanism.@*METHODS@#Mouse BMSCs were isolated and cultured, then infected by recombinant lentivirus carrying Cxcr4 gene. The expression of green fluorescence was observed through fluorescence microscope, the expression of Cxcr4 mRNA was detected by real-time fluorescence quantitative PCR, and the BMSC-derived exosomes modified with Cxcr4 gene were extracted. Mouse models of AA were constructed, and control group, model group (AA), AA+BMSC group, AA+NC-BMSC group, AA+Cxcr4-BMSC group were set up. Except control group and model group, the other three groups of mice were injected 400 μl exosomes from different sources via the tail vein, after 2 weeks, the routine blood indices and the number of bone marrow nucleated cells were detected, the pathological changes of bone marrow were observed by HE staining, and the expression level of Treg cells was detected by flow cytometry.@*RESULTS@#Mouse BMSCs were successfully isolated, and BMSCs with high expression of Cxcr4 and their exosomes were obtained. Compared with the control group, the number of red blood cell (RBC), white blood cell (WBC), and platelet (PLT), the hemoglobin (Hb) content and proportion of Treg cells in the peripheral blood of mice in the model group significantly decreased (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01). The proliferation level of nucleated cells was low, and the medullary cavity was filled with a large number of fat cells. Compared with the model group, the number of RBC, WBC, PLT, the Hb content and proportion of Treg cells in the peripheral blood of mice in the AA+BMSC group, AA+NC-BMSC group, and AA+Cxcr4-BMSC group significantly increased (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01), and pathological changes of bone marrow were improved. In addition, the number of RBC, WBC, PLT, the Hb content and proportion of Treg cells in the peripheral blood of mice in the AA+Cxcr4-BMSC group were significantly higher than those in the AA+BMSC group (P<0.01), as well as the number of bone marrow nucleated cells (P<0.01).@*CONCLUSION@#Injection of Cxcr4 gene-modified BMSC-derived exosomes has a certain improvement effect on AA mice, and the mechanism may be related to an increase of the proportion of Treg cells.

Clinical Study on Calcitriol Combined with Sirolimus in the Treatment of Chronic Primary Immune Thrombocytopenia Patients / 中国实验血液学杂志

OBJECTIVE@#To investigate the clinical efficacy of calcitriol combined with sirolimus in the treatment of chronic primary immune thrombocytopenia (cITP) patients.@*METHODS@#A total of 146 adult cITP patients reated in the First Affiliated Hospital of Hebei North University from March 2017 to March 2020 were randomly divided into observation group (73 cases) and control group (73 cases) according to random number table. The control group was treated with oral sirolimus capsule, the observation group was treated with oral calcitriol capsule combined with sirolimus capsule, and the curative effect of the 2 groups was evaluated after continuous treatment for 6 weeks. The changes of World Health Organization (WHO) bleeding grade, laboratory related index, including peripheral blood regulatory T cell (Treg), serum 1,25-dihydroxy-vitamin D@*RESULTS@#The total effective rate of the observation group was 79.5% (58/73), which was significantly higher than 64.4% (47/73) of the control group (P<0.05). The revised WHO bleeding grades after treatment were significantly better than those before treatment in the 2 groups (P<0.05), but the observation group was improved more significantly than the control group (P<0.05). After treatment, platelet count (PLT), peripheral blood Treg cell ratio, and serum 1,25(OH)@*CONCLUSION@#The overall efficacy of calcitriol combined with sirolimus in the treatment of cITP in adults is satisfactory, which can effectively alleviate patient's condition, improve the quality of life, further increase the platelet level and decrease the expression of VDR in peripheral blood lymphocyte, the mechanism may be related to increasing the level of serum 1,25(OH)

Inhibitory Effect of miR-125b Down-Regulation on Proliferation of Leukemia Cell K562 / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore inhibitory effect of miR-125b down-regulation on proliferation of leukemia cell K562.</p><p><b>METHODS</b>miR-125b inhibitor and miR-125b NC were transfected into K562 cells by liposome Lipofectamine2000, the cell viability was measured by MTT assay, cell cloning ability was detected by agarose cloning assay, cell cycle was measured by flow cytometry. The expression of BCL-2, BCL-2 homology antagonist/liller 1(BAK1), p53 and p53 up-regulated modulator of apoptosis (Puma) was measured by Western blot.</p><p><b>RESULTS</b>Compared with miR-125b NC, the expression of miR-125b was down-regulated (P<0.01), the cell viability and cell cloning ability were reduced (P<0.01), the cell cycle was arrested in the G phase (P<0.01), the expression of BCL-2 were down-regulated (P<0.01), the expression of BAK1, p53 and Puma were up-regulated in miR-125b inhibitor group (P<0.01).</p><p><b>CONCLUSION</b>Down-regulation of miR-125b can inhibit K562 cell proliferation via down-regulating the expressions of BCL-2 and up-regulating the expression of BAK1, p53 and Puma.</p>

Endurance training attenuates the bioenergetics alterations of rat skeletal muscle mitochondria submitted to acute hypoxia: role of ROS and UCP3 / 生理学报

The physiological significance of skeletal muscle mitochondrial uncoupling protein 3 (UCP3) in hypoxia is elusive. In the current study, UCP3 mRNA and protein expressions were investigated along with mitochondrial respiratory function, reactive oxygen species (ROS) generation, as well as manganese superoxide dismutase (MnSOD) expression in rat skeletal muscle with or without endurance training after an acute and severe hypobaric hypoxia exposure for different time. Acute hypoxia induced a series of impairments in skeletal muscle mitochondrial bioenergetics. In untrained rats, UCP3 protein content increased by 60% above resting level at 4 h hypoxia, whereas MnSOD protein content and activity were unaltered. UCP3 upregulation increased mitochondrial uncoupling respiration thus reducing O2(.-) generation, but inevitably decreased ATP production. Training decreased acute hypoxia-induced upregulation of UCP3 protein (67% vs 42%) in rat skeletal muscle. ROS production in trained rats also showed a dramatic decrease at 2 h, 4 h and 6 h, respectively, compared with that in untrained rats. MnSOD protein contents and activities were significantly (50% and 34%) higher in trained than those in untrained rats. Training adaptation of MnSOD may enhance the mitochondrial tolerance to ROS production, and reduce UCP3 activation during severe hypoxia, thus maintaining the efficiency of oxidative phosphorylation. In trained rats, mitochondrial respiratory control (RCR) and P/O ratios were maintained relatively constant despite severe hypoxia, whereas in untrained rats RCR and P/O ratios were significantly decreased. These results indicate that (1) UCP3 mRNA and protein expression in rat skeletal muscle are upregulated during acute and severe hypobaric hypoxia, which may reduce the increased cross-membrane potential (Deltapsi) and thus ROS production; (2) Endurance training can blunt hypoxia-induced UCP3 upregulation, and improve mitochondrial efficiency of oxidative phosphorylation due to increased removal of ROS.

Effect of ginkgolide B on plasma levels of interleukin-12 and PAF in severe acute pancreatitis in rats / 中国应用生理学杂志

<p><b>AIM</b>To observe the levels of interleukin-12 (IL-12) and platelet activating factor (PAF) in severe acute pancreatitis (SAP) in rats and the efficacy of Ginkgolide B (BN52021) in treating SAP.</p><p><b>METHODS</b>Wistar rats were randomly divided into 3 groups: model group (SAP), treatment group (BN) and negative control group (NC). SAP was induced by retrograde infusion of 5% sodium taurocholate into the pancreatic duct in Wistar rats. NC rats only receive abdominal incision. In groups of SAP and NC rats received the femoral vein injection of isotonic Na chloride 15 minutes after induction of SAP; in BN group,rats received BN52021 instead. After operation rats were sacrificed at 1, 6 and 12 hour for plasma IL-12 and PAF determined with ELISA.</p><p><b>RESULTS</b>An increase of IL-12 in group BN was observed VS group SAP or group NC at 1 h stage (p = 0.011, P < 0.01). At 6 h or 12 h stage,an increase of IL-12 in group SAP was observed VS group NC (P < 0.01, P < 0.05). The plasma level of PAF in group SAP or group BN was increased significantly at 1 h time stage VS group NC (P < 0.001). At 6 h or 12 h stage, a decrease of PAF in group BN or group NC was observed VS group SAP (P < 0.05, P < 0.01).</p><p><b>CONCLUSION</b>It confirmed that the plasma level of cytokine IL-12 in SAP group was decreased significantly in early stage and it witnessed a remarkable increase of cytokine PAF. The plasma level of IL-12 was increased in early stage but PAF was decreased in rats treatment by BN52021 which inhibited the development of SAP.</p>

Effect of yiqi huoxue recipe on cardiac function and ultrastructure in regression of pressure overload-induced myocardial hypertrophy in rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of Yiqi Huoxue Recipe (YHR) on the cardiac function and ultrastructure during the regression of myocardial hypertrophy induced by pressure overload in rats.</p><p><b>METHODS</b>The model of myocardial hypertrophy was established by abdominal aortic banding. Eighty male Wistar rats were divided into six groups, the normal control group I (n=20), the normal control group II (n=12), the hypertension model group I (n=12), the hypertension model group II (n=12), the YHR group (n=12) and the Captopril group (n=12). The observation was carried out in the normal control group I and the hypertension model group I after 4 weeks of modeling, and the other four groups were observed after 16 weeks of modeling (12 weeks of administration). The cardiac function was measured with a multichannel biological signal analysis system, and the myocardium ultrastructure was observed by a transmission electron microscope.</p><p><b>RESULTS</b>(1) Compared with the normal control group I, the systolic blood pressure and cardiac coefficient (left ventricular weight/body weight) in the model I group was higher (P<0.05, P<0.01). (2) In the YHR group, cardiac coefficient and -dp/dt(max) were lower, left ventricular systolic pressure and +dp/dt(min) were higher when compared with the model group II and the Captopril group (P<0.05 or P<0.01). In the Captopril group, only cardiac coefficient was lower when compared with the mode group II (P<0.05). (3) Compared with the normal control group II, +dp/dt(max) was higher (P<0.01) -dp/dt(max) and isovolumetric contraction time (ICT) was lower (P<0.05, P<0.01) in both the YHR group and the Captopril group. (4) Results of the myocardium ultrastructure showed edema under myocardium plasmalemma, enlarged sarcoplasmic reticulum and T tube, and significantly enlarged intercalated disc of the cardiac muscle in the model groups. In the Captopril group, the extension of sarcoplasmic reticulum and T tube as well as the pathological changes of intercalated disc were lighter, with slight edema under the myocardium plasmalemma. In the YHR group, the expansion of the sarcoplasmic reticulum was less than in the Captopril group, part of the pathological changes of intercalated discs was slightly more severe than that in the Captopril group, the dissolution of nuclear chromatin was not found, which was similar to that of the Captopril group, and no injury of the nucleus was found, either.</p><p><b>CONCLUSION</b>YHR could reverse myocardial hypertrophy in rats with abdominal aortic banding and improve the systolic and diastolic function of the left ventricle. The ultrastructure of the myocardium such as arcoplasmic reticulum, intercalated disc, and cell nucleus in abdominal aortic banding rats could be partly reversed by the recipe.</p>

Study of correlation factors with left ventricular hypertrophy during cardiac hypertrophy induced hypertension and regression in rats / 中国应用生理学杂志

<p><b>AIM</b>To investigate the relations between left ventricular hypertrophy and systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), neuropeptide Y (NPY) during cardiac hypertrophy and regression.</p><p><b>METHODS</b>Blood pressure and heart rate were recorded with polygraph channel biologic message system. NPY in plasma and myocardium were measured with Radioimmunoassay. Correlation coefficient were calculated with SPSS software.</p><p><b>RESULTS</b>There were positive correlations between SBP, DBP, MAP, NPY in the cardiac tissue and cardiac coefficient (LVW/BW). There was no correlations between cardiac coefficient and heart rate (HR), NPY in plasma.</p><p><b>CONCLUSION</b>Hypertension is one of cardiac hypertrophy factors, SBP correlate better with LVW/ BW than DBP. SBP, DBP, MAP, NPY in cardiac tissue has correlative tendency with LVW/BW.</p>