Construction of a Mouse Model for Myeloproliferative Neoplasms and an Evaluation System / 中国实验血液学杂志

OBJECTIVE@#To construct a myeloproliferative neoplasms (MPN) transplanted mouse model with JAK2-V617F, MPLW515L or CALR-Type I gene mutation, and establish a systematic evaluation system to verify the success of model construction.@*METHODS@#The bone marrow c-kit+ cells of the mice were obtained by the following steps: The mice were killed by cervical dislocation, the femur, tibia and ilium were separated, and the bone marrow cells were collected. The c-kit+ cells were sorted after incubation with CD117 magnetic beads. The method of constructing mouse primary mutant cells is as follows: A gene mutation vector with a GFP tag was constructed by the retroviral system, and the retroviral vector was packaged into the Platinum-E cells to obtain the virus supernatant, and then used it to infect the c-kit+ cells of mice. The MPN mouse model was constructed as follows: the mouse primary c-kit+ cells containing the mutant genes were collected after infection, and then transplanted them via the tail vein into the female recipient mice of the same species which were irradiated with a lethal dose of gamma rays (8.0 Gy). The MPN mouse model was evaluated as follows: After transplantation, the peripheral blood of the mice was regularly collected from the tail vein to perform the complete blood count test, and the size of spleen and the degree of bone marrow fibrosis were estimated.@*RESULTS@#The mouse c-kit+ cells with the mutant genes were successfully obtained from the bone marrow. MPN mouse model was successfully constructed: The peripheral blood cells of the MPN-transplanted mice carried exogenous implanted GFP-positive cells, and the white blood cells (WBC), platelet (PLT) and hematocrit (HCT) were all increased; the body weight loss, and the water and food intake were reduced in the transplanted mice; further pathological analysis showed that the transplanted mice displayed splenomegaly and bone marrow fibrosis. These results suggested that the MPN mouse model was successfully constructed. According to the common and different characteristics of the three MPN mouse model, a preliminary evaluation system for judging the success of MPN mouse model construction was summarized, which mainly included the following indicators, for example, the proportion of GFP-positive cells in the peripheral blood of mice; WBC, PLT and HCT; the degree of spleen enlargement and the bone marrow fibrosis.@*CONCLUSION@#The MPN mouse model with JAK2-V617F, MPLW515L or CALR-Type I gene mutation is successfully established by retroviral system, which can provide an important experimental animal model for the research of MPN pathogenesis and drug-targeted therapy.

Establishment of Human Chronic Lymphocytic Leukemia Model in the BALB/c Nude Mice by Using MEC-1 and HG3 Cell Lines / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the the optimal condition for establishing immune deficiency mouse(BALB/c) model with CLL via subcutaneous inoculation of human chronic lymphocytic leukemia (CLL) cells at different inoculative locations and different cell concentrations.</p><p><b>METHODS</b>Firstly, Two CLL cell lines (MEC-1-GFP and HG3-GFP)with the green fluorescent protein (GFP) were established by lentivirus system respectively, and then the MEC-1-GFP cells (5×10/ml) were inoculated into forelimb, hindlimb and abdomen to observe the tumorigenesis. Secondly, the MEC-1-GFP and HG3-GFP cells with same density (5×10/ml) were inoculated into forelimb to compare the time and rate of tumor formation. Thirdly, the MEC-1-GFP cells (1×10/ml) and HG3-GFP cells (5×10/ml) were inoculated into forelimb to compare the time and rate of tumor formation at different inoculative density. After observation for 5 weeks, the peripheral blood was collected and treated with EDTA and erythrocytolysin, then the of GFP positive cells were detected by flow cytomety. Meanwhile, the tumor-bearing mice were killed, and the tumors were isolated and cut into slices for histopathological examination.</p><p><b>RESULTS</b>MEC-1-GFP and HG3-GFP cell lines were successfully established, and after inocutation of MEC-1-GFP cells with 5×10/ml the xenograt tumors were formated in forelimb, hindlimb and abdomen of mice, especially in the forelimb with a higher tumorigenic rate. In addition, the inoculation of same density of MEC-1-GFP and HG3-GFP cells (5×10/ml) also resulted in xenograft in forelimb, and the tumorigenic rate reached to 80% after 5 weeks. Moreover, the inocutation of MEC-1-GFP and HG3-GFP cells with 1×10and 5×10/ml respectively also effectively resulted to xenograft tumor in forelimb. The flow cytometry showed that there was no MEC-1-GFP and HG3-GFP cells in peripheral blood, while histopathological examination demonstrated CLL cell metastasis towards peritoneal cavity.</p><p><b>CONCLUSION</b>The BALB/c nude mouse model is successfully established by subcutaneous injection of MEC-1-GFP and HG3-GFP cells. This model is a useful tool to explore the pathogenic mechanism.</p>

Relations between saliva arsenic levels and serum arsenic and urinary arsenic of rats after exposed to different levels of sodium arsenite / 中国地方病学杂志

Objective To investigate the relations between saliva arsenic levels and serum arsenic and urinary arsenic of rats after exposed to different levels of sodium arsenite.Methods Thirty-two SD rats were randomly divided into four groups(8 rats in each group),namely the control group,the low,the medium,and the high doses of sodium arsenite exposure groups.Rats of the control group were given 0.9％ NaCI by gavage,and other three groups were given sodium arsenite of 0.2,2.0,20.0 mg/kg body weight by gavage.All animals were administrated every other day for two weeks,then saliva,blood,urine and tissue organs were collected,organ coefficients were calculated,total arsenic concentrations in blood and urine were detected by Atomic Fluorescence Spectrometry(AFS-230) and total arsenic concentration in saliva was detected by Inductively Coupled Plasma Mass Spectrometer(ICP-MS).Results The weight gain values of rats exposed to sodium arsenite were lower than that of the control group,the difference was statistically significant between the highest dose group[(76.13 ± 17.19)g]and the control group[(103.00 ± 12.31)g,P ＜ 0.05].The liver and kidney organ coefficients in the highest dose group [(3.92 ± 0.54)％,(0.96 ± 0.15)％]were significantly higher than that in the control group[(3.27 ± 0.35)％,(0.76 ± 0.05)％,P ＜ 0.05 or ＜ 0.01].The total arsenic concentrations in saliva[(0.044 ± 0.019),(0.211 ± 0.071),(1.128 ± 0.380)mg/L],blood[(11.832 ± 1.887),(45.032 ± 7.216),(121.839 ± 17.323)mg/L]and urine[(0.138 ± 0.085),(0.874 ± 0.328),(8.843 ± 1.754)mg/L]in the three treatment groups were significantly higher compared with that of the control group [(0.018 ± 0.014),(2.267 ± 0.370),(0.025 ± 0.011)mg/L,all P ＜ 0.05],furthermore,there was a significant difference among the three treatment groups (all P ＜ 0.05).The arsenic contents in saliva were significantly correlated with blood arsenic and urinary arsenic,the correlation coefficient was 0.934 and 0.960,respectively (all P ＜ 0.01).Conclusions High dose of arsenic exposure,with a strong toxicity to liver and kidney,can inhibit the increase of rat body weight.Arsenic dose-response relationship exists in the saliva,and saliva arsenic is significantly correlated with blood arsenic and urinary arsenic,suggesting that salivary arsenic can be used as a new biomarker for assessing human exposure to arsenic.

Biomarkers of early vascular endothelial injury with low-arsenic exposure in drinking water / 中国地方病学杂志

Objective To observes the change of early effective biomarkers of endothelial injury with lowarsenic exposure in drinking water. MethodsNinety rurad residents, who had lived in Yanhe village, Xuyi county and Jiangsu province for at least 10 years, were recruited by simple random sampling in this study. The level of arsenic in their household shallow well were divided into three groups, which were ＜ 10 (32 people), 10 - 50(28 people) and ＞ 50 μg/L(30 people). Blood samples from individuals were collected. Malondialdehyde(MDA) in human plasma, which is considered as the most important marker for monitoring lipid peroxidation, was determined as conjugate with tetrabutylammonium hydrogen sulphate(TBA). The level of anti-superoxide anion radical(O-·2),C-reactive protein(CRP) and NO in human plasma was measured with colorimetry, turbidimetry and nitric acid reductase, respectively. The number of circulating endothelial progenitor cells(CEPCs) in peripheral blood was analyzed by CD133+/KDR+ antibodies and flow cytometry. Results Ninety cases underwent questionnaires. Between the groups, the difference of the levels of MDA (61.1, 65.5, 67.5 μmol/kg), O-·2 (4774.6, 5143.3, 4736.0 U/kg) ,CRP[(5.92 ± 2.44), (5.11 ± 2.40), (5.55 ± 2.96)mg/L], and NO[(659.8 ± 387.5), (667.4 ± 486.6), (762.1 ±763.2)μmol/kg], was not statistically significant (F =0.00, 0.46, 0.80, 0.47, all P ＞ 0.05). The difference of the number of CEPCs in different groups of arsenic in drinking water was statistically significant(0.96 x 10-5, 0.77 x 10-5,1.59 x 10-5, F=5.08, P＜ 0.05), where ＜ 10, 10 - 50 μg/L groups were significantly lower than ＞ 50 μg/L group (q =4.58, 6.65, all P ＜ 0.05). ConclusionsThe number of CEPCs in peripheral blood changes significantly with lower-arsenic exposure, whereas there are no obvious changes with the markers of oxidized damage and inflammation. This is the first human demonstration showing that lower-arsenic exposure may cause endothelial injury.

Roles of the histaminergic receptors in the locus ceruleus in stress-induced carotid baroreflex resetting in rats / 中国应用生理学杂志

<p><b>AIM</b>To explore the roles of H1 and H2 receptors in the locus ceruleus (LC) in the carotid baroreflex (CBR) resetting resulted from foot-shock stress.</p><p><b>METHODS</b>Male SD rats were divided into two groups (n=18) at random: unstressed and stressed group. The latter were subjected to unavoidable electric foot-shock twice daily for a week and each session of foot-shock lasted 2 hours. The left and right carotid sinus regions were isolated from the systemic circulation in all animals anesthetized with pentobarbital sodium. The intracarotid sinus pressure (ISP) was altered in a stepwise manner in vivo. ISP-mean arterial pressure (MAP), ISP-Gain relationship curves and reflex characteristic parameters were constructed by fitting to the logistic function with five parameters. The changes in CBR performance induced by stress and the effects of microinjection with histaminergic receptors antagonists into the LC on the responses of CBR to stress were examined.</p><p><b>RESULTS</b>Stress significantly shifted the ISP-MAP relationship curve upwards (P < 0.05) and obviously moved the middle part of ISP-Gain relationship curve downwards (P < 0.05), and decreased the value of the MAP range and maximum gain (P < 0.05), but increased the threshold pressure, saturation pressure, set point and ISP at maximum gain (P < 0.05). Microinjection of selective H1 or H2 receptor antagonist, chlorpheniramine (CHL, 0.5 microg/microl) or cimetidine (CIM, 1.5 microg/microl) into the LC, significantly attenuated the above-mentioned changes in CBR performance induced by stress and the alleviate effect of CIM was less remarkable than that of CHL (P < 0.05). The responses of CBR under stress to H1 or H2 receptor antagonist generally occurred 20 min after the administration and lasted approximately for 16 min. Microinjection with the same dose of CHL or CIM into the LC in the unstressed group did not change CBR performance significantly (P > 0.05). However, microinjection of CHL or CIM into the LC could not completely abolish the stress-induced changes in CBR.</p><p><b>CONCLUSION</b>The stress results in a resetting of CBR and a decrease in reflex sensitivity. The stress-induced changes in CBR may be mediated, at least in part, by activating the brain histaminergic system. The H1 and H2 receptors in the LC, especially, Hi receptors may play an important role in the resetting of CBR under stress. The descending histaminergic pathway from the hypothalamus to LC may be involved in these effects. Moreover, the effects of stress on CBR also have other mechanisms.</p>

Circadian rhythms and different photoresponses of Clock gene transcription in the rat suprachiasmatic nucleus and pineal gland / 生理学报

The aim of this study was to observe and compare the endogenous circadian rhythm and photoresponse of Clock gene transcription in the suprachiasmatic nucleus (SCN) and pineal gland (PG) of rats. With free access to food and water in special darkrooms, Sprague-Dawley rats were housed under the light regime of constant darkness (DD) for 8 weeks (n=36) or 12 hour-light: 12 hour-dark cycle (LD) for 4 weeks (n=36), respectively. Then, their SCN and PG were dissected out every 4 h in a circadian day, 6 rats at each time (n=6). All animal treatments and sampling during the dark phases were conducted under red dim light (<0.1 lux). The total RNA was extracted from each sample and the semi-quantitative RT-PCR was used to determine the temporal mRNA changes of Clock gene in the SCN and PG at different circadian times (CT) or zeitgeber times (ZT). The grayness ratio of Clock/H3.3 bands was served as the relative estimation of Clock gene expression. The experimental data were analyzed by the Cosine method and the Clock Lab software to fit original results measured at 6 time points and to simulate a circadian rhythmic curve which was then examined for statistical difference by the amplitude F test. The main results are as follows: (1) The mRNA levels of Clock gene in the SCN under DD regime displayed the circadian oscillation (P<0.05). The endogenous rhythmic profiles of Clock gene transcription in the PG were similar to those in the SCN (P>0.05) throughout the day with the peak at the subjective night (CT15 in the SCN or CT18 in the PG) and the trough during the subjective day (CT3 in the SCN or CT6 in the PG). (2) Clock gene transcription in the SCN under LD cycle also showed the circadian oscillation (P<0.05), and the rhythmic profile was anti-phasic to that under DD condition (P<0.05). The amplitude and the mRNA level at the peak of Clock gene transcription in the SCN under LD were significantly increased compared with that under DD (P<0.05), while the value of corresponding rhythmic parameters in the PG under LD were remarkably decreased (P<0.05). (3) Under LD cycle, the circadian profiles of Clock gene transcription induced by light in the PG were quite different from those in the SCN (P<0.05). Their Clock transcription rhythms were anti-phasic, i.e., showing peaks at the light phase ZT10 in the SCN or at the dark time ZT17 in the PG and troughs during the dark time ZT22 in the SCN or during the light phase ZT5 in the PG. The findings of the present study indicate a synchronous endogenous nature of the Clock gene circadian transcriptions in the SCN and PG, and different roles of light regime in modulating the circadian transcriptions of Clock gene in these two central nuclei.