1.Study on the Toxicity of Ambient PM2.5 to Primary Cultured Myocardial Cells of Neonatal Rats
Canjun ZHENG ; Feifei WANG ; Xinbiao GUO
Journal of Environment and Health 1993;0(01):-
Objective To understand the ambient PM2.5 component and the toxicity to primary cultured myocardial cells of neonatal rats. Methods Primary myocardial cells cultures were prepared from 1-day-old Sprague-Dawley rats and treated with PM2.5 suspension and its organic and water-soluble extracts at various concentrations for 24 h. The cellular viability was measured with MTT methods, and the beat of myocardial cells was observed and counted under inverted microscope. Results PM2.5 suspension and its organic and water-soluble extracts increased the viability of myocardial cells at the concentrations below 10.0 ?g/ml, but above this, they could significantly decrease the viability of myocardial cells with a dose-dependent manner. The toxicity of organic extract of PM2.5 was significantly higher than that of water-soluble extract. PM2.5 suspension and its organic and water-soluble extracts also dose-dependently inhibited the beat frequencies of myocardial cells. Conclusion PM2.5 and its extracts show a hormesis effect on the cultured myocardial cells in the case of the cellular viability is taken as the response parameter. PM2.5 and its extracts can inhibit the beat of myocardial cells.
2.Effects of Green Tea Polyphenols on LDLR Function and Potential Mechanism in HepG2 Cells
Feifei LI ; Zhanpeng WEN ; Yue GUO ; Xiaodong ZHUANG ; Zhimin DU
Journal of Sun Yat-sen University(Medical Sciences) 2017;38(3):359-363
[Objective] To investigate the effects of the bioactive constituents of green tea polyphenols epigallocatechin gallate (EGCG) on low density lipoprotein receptor (LDLR) function of HepG2 cells.[Methods] The optimal concentration and cell proliferation of HepG2 cells were determined by CCK8 assay,and Western blotting was used to determine LDLR and PCSK9 protein levels,respectively,and LDL uptake in HepG2 cells was detected by fluorescence microscope.[Results] EGCG elevated LDLR protein expression,reduced PCSK9 protein expression and promoted LDL uptake in HepG2 cells.[Conclusion] EGCG may increase LDLR abundance by down-regulating PCSK9 protein and attenuating LDLR protein degradation,which providing a new approach for lipid lowering therapy.
3.Nesfatin-1 Signaling in the Basom Edial Amygdala Modulates the Gastric Distension-sensitive Neurons Discharge and Decreases Gastric Motility by the Arcuate Nucleus
Qiuxia DUAN ; Xiao LUAN ; Feifei GUO ; Xiangrong SUN ; Luo XU
Progress in Modern Biomedicine 2017;17(27):5227-5232,5246
Objective:This study aimed to explore the effects ofnesfatin-1 on gastric distension (GD)-sensitive neurons in the basomedial amygdala (BMA) and the potential mechanism for nesfatin-1 to regulate gastric motility through the arcuate nucleus (Arc).Methods:The projection of nerve fiber and expression of nesfatin-1 were observed by retrograde tracing and fluo-immunohistochemistry staining;The nuclei microinjection and nuclei electrical stimulation,extracellular discharges of single unit neuron were used to observe the effects ofnesfatin-1 on the GD neurons;Gastric motility recording in vivo were used to monitor the effects ofnesfatin-1 on the amplitude of constriction and frequency of gastric motility in conscious rats.Results:NUCB2/Nesfatin-1/fluorogold-double labeled neurons were from ARC to BMA;Nesfatin-1 could excited the firing rate of most of the GD-E neurons (4.25± 1.02 Hz vs.5.32± 1.17 Hz,P<0.01) and decreased the firing rate of most of the GD-I neurons (3.73± 0.92 Hz vs.2.64± 0.86 Hz,P<0.01),inhibited the gastric motility,amplitude and frequency,SHU9119 could weaken the responses induced by nesfaton-1;Electrical stimulation of the Arc,the firing rate of nesfatin-1-induced GD-response neurons (GD-E:5.14± 1.32 Hz vs.6.75± 1.84 Hz,P<0.05;GD-I:2.84± 0.86 Hz vs.4.05± 1.12 Hz,P <0.05) and the gastric amplitude and frequency were increase.Conclusion:It was suggested that nesfatin-1 in the BMA plays an important role in decreasing gastric motility and the Arc may be involved in this regulation process.
4.The Effects ofNesfatin-1 in the Paraventricular Nucleus on Gastric Motility and Its Potential Regulation by the Lateral Hypothalamic Area in Rats
Song SHI ; Xiao LUAN ; Yang LIU ; Feifei GUO ; Luo XU
Progress in Modern Biomedicine 2017;17(25):4831-4836,4891
Objective:The current study investigated the effects of nesfatin-1 in the hypothalamic paraventricular nucleus (PVN) on gastric motility and the regulation of the lateral hypothalamic area (LHA).Methods:The projection of nerve ?ber and expression of nesfatin-1 were observed by retrograde tracing and fluo-immunohistochemistry staining;The nuclei microinjection and nuclei electrical stimulation,extracellular discharges of single unit neuron were used to observe the effects of nesfatin-1 on the GD neurons;Gastric motility recording in vivo were used to monitor the effects of nesfatin-1 on the amplitude of constriction and frequency of gastric motility in conscious rats.Results:Nesfatin-1 inhibited the majority of the GD-E neurons(1.97± 0.12 Hz vs.1.15± 0.07 Hz) and excited GD-I neurons (1.74± 0.10 Hz vs.3.04± 0.18 Hz) in the PVN,which were weakened by oxytocin receptor antagonist H4928 (GD-E:1.38± 0.08 Hz,P<0.05 vs.nesfatin-1;GD-I:2.49± 0.15 Hz,P<0.05 vs.nesfatin-1).Gastric motility experiments showed that administration ofnesfatin-1 in the PVN decreased gastric motility.Retrograde tracing and immunofluorescent staining showed that nucleobindin-2/nesfatin-1 and fluorogold double-labeled neurons were observed in the LHA.Electrical LHA stimulation excited the firing rate of GD-responsive neurons (GD-E:2.06± 0.12 Hz vs.4.23± 0.21 Hz,GD-I:1.61± 0.09 Hz vs.4.83± 0.25 Hz) in the PVN.Pre-administration of an antinucleobindin-2/nesfatin-1 antibody in the PVN strengthened gastric motility,decreased GD-E neurons (1.74± 0.10 Hz vs.3.04± 0.18 Hz) and excited the discharging of the GD-I neurons(4.15± 0.18 Hz vs.4.83± 0.25) induced by electrical stimulation of the LHA.Conclusion:Nesfatin-1 in the PVN could serve as an inhibitory factor to inhibit gastric motility,which might be regulated by the LHA.
5.Effects of Orexins on Feeding and Energy Metabolism in Mice
Ying CHEN ; Feifei GUO ; Xiangrong SUN ; Luo XU
Progress in Modern Biomedicine 2017;17(26):5038-5042,5078
Objective:To investigate the effects of Orexin peptides on feeding and energy metabolism in mice.Methods:The mice were divided into two groups:feeding group and metabolic group.The feeding group were injected with different doses (1,3 and 10 nmol) of orexin-A and orexin-B to observe their effects on feeding and the activity of tyrosine hydroxylase in liver.We used the metabolic cages and observed the changes of respiration rate and respiration rate of mice were under light condition,dark condition and fasting condition.Results:Compared with the control group,1 nmol and 10 nmol orexin-A significantly stimulated mice to feed (P <0.05) within 4 hours after injection,and the effect of 3 nmol orexin-A on feeding was not obvious,but increase the activity of tyrosine hydroxylase.Any dose of orexin-B did not show a stimulating effect on mice feeding.(P >0.05).In the light cycle,orexin-A could significantly reduce the respiration rate (RQ),the metabolic rate was significantly increased (P <0.05);In the dark cycle,orexin-A had no effect on RQ,but the metabolic rate was significantly rised (P <0.05);But the injection of orexin-A in fasting mice induced a brief increase in RQ and a significant increase in metabolic rate (P <0.05).Conclusion:Orexins may play an important role in regulating feeding and energy metabolism in mice.
6.Effects of mitochondrial fission in proliferation, apoptosis and invasion of thyroid squamous carcinoma cell line SW579
Feifei SHEN ; Rui GUO ; Shupeng ZHAO ; Fengjie QI ; Cuili MENG
Tianjin Medical Journal 2015;(2):129-132,133
Objective To detect the expression of mitochondrial dynamics proteins (Mfn2 and Drp1) in thyroid squa?mous carcinoma cell line SW579 and the effects of Mitochondrial division inhibitor, Mdivi-1, on proliferation, apoptosis and invasion of SW579. Methods In SW579 and Nthy-ori 3-1 cell lines, the expression levels of Mfn2 and Drp1 were deter?mined by western blot while the transcription level of Mfn2 and Drp1 mRNA were measured by RT-PCR. Then, SW579 cells were divided into control group (DMSO, 0.1%) and Mdivi-1 low, medium and high dose groups (Mdivi-1 of 15,30 and 45μmol/L were incubated with cells for 16 hours respectively). Then the ability of cell proliferation was detected using MTT assay, the mitochondrial membrane potential was determined by fluorescence spectrophotometer, the expression levels of cy?tochrome C and Caspase-3 were quantified by Western blot and the transcription level of the Cyt C and Caspase-3 mRNA were determined by RT-PCR. The ability of invasion in each group was measured with Transwell assays. Results Com?pared with Nthy-ori 3-1, the mRNA transcription and protein expression levels of the Mfn2 was remarkably decreased, while the mRNA transcription and protein expression of the Drp1 was significantly increased in SW579 cells (P<0.01). Compared with control group, the cell survival rates and mitochondrial membrane potential of SW579 were decreased dramat?ically (P<0.01). The mRNA transcription and protein expression of the cytochrome C and Caspase-3 were increased dra?matically (P<0.01) and the capability of invasion was markedly decreased in all the Mdivi-1 groups in a dosage dependent manner compared with those in control groups (P<0.01). Conclusion Abnormal mitochondrial dynamics may be involved in thyroid squamous cell carcinoma SW579 cells;Mdivi-1 can inhibit the cell proliferation and invasion as well as induce apoptosis.
7.A comparative study of social support and sense of security between left-behind women and non left-behind women in rural area
Kejian GUO ; Jie ZHAO ; Liling XIAO ; Feifei MA ; Gongying LI
Chinese Journal of Behavioral Medicine and Brain Science 2016;25(11):1043-1045
Objective To compare the difference of the sense of security and social support between left-behind women and non left-behind women in rural area.Methods Social Support Rating Scale (SSRS) and security questionnaire(SQ) were used to measure social support and sense of security of 98 left-behind women and 151 non left-behind women.The data was analyzed by SPSS17.0.Results ①In the social support rating,compared with the non left-behind women,the left-behind women has lower score in the total score((40.561±6.692) vs (59.722±8.699),t=18.530),determining the control factor((21.459±3.891) vs (30.013±4.950),t=14.450) and human security factor((19.102±3.737) vs (29.709±4.849),t=18.392) and the differences were statistical significant(all P<0.05).②In the social support rating scale,left-behind women had lower scores in total score,exploitation degree of support,subjective support and objective support than the left-behind women(all P<0.05).③The total score and each factor score of security scale,and the total score and each factor score of social support rating scale in the left-behind women showed significantly positively correlated(r=0.245-0.507,P<0.05).Conclusion The sense of security and social support of the left behind women were worse than that of non left-behind women.It is necessary to carry out psychological intervention for them.
8.Effect of thyroidal motilin on gastric motility and central modulation in rat thyroid
Feifei GUO ; Luo XU ; Shengli GAO ; Xiangrong SUN
Chinese Journal of Endocrinology and Metabolism 2012;(12):1005-1011
Objective To research the functional role of thyroidal motilin and the effects of electric excitation of the paraventricular nuclei(PVN) on gastric motility and the levels of motilin in thyroid and plasma.Methods The expression of motilin in rat and human thyroid was detected by immunofluorescence staining.A phase Ⅲ-like contraction was recorded before and after thyroidectomy and after PVN excitation.The changes in concentrations of plasma FT3,FT4 and motilin were determined via radioimmunoassay (RIA).c-Fos expression of PVN after thyroidectomy and motilin expression in thyroid after PVN excitation were observed by immunohistochemical staining.Results There were motilin immunoreactive cells in rat and human thyroid.The phase Ⅲ-like contraction and concentration of motilin in plasma decreased significantly when measured on the second and fourth days after thyroidectomy(2d,P<0.01 ;4d,P<0.05).The expression of c-Fos in PVN after thyroidectomy was significantly increased(P<0.05).An electric excitation of PVN could increase the concentration of motilin in plasma and thyroid and increase corresponding gastric motility in rats (P <0.05).The increased phase Ⅲ-like contraction by PVN excitation could be partially inhibited by administration of motilin receptor antagonist,GM-109 (P<0.05).Excitation of PVN in thyroidectomized rats resulted in lower plasma motilin and less intense phase Ⅲ-like contraction of stomach,as compared with the sham operated control group(P<0.05).Conclusion Motilin from the thyroid may be secreted into the peripheral plasma to affect gastric motility and PVN may modulate gastric motility and motilin expression in the thyroid.
9.Preliminary study on pH-sensitive lipid bilayer-coated mesoporous silica nanoparticles as a novel drug carrier for antitumor drug.
Feifei LI ; Xinxin ZHANG ; Shiyan GUO ; Yong GAN ; Juan LI
Acta Pharmaceutica Sinica 2013;48(2):291-7
This study plans to prepare lipid bilayer-coated mesoporous silica nanoparticles (LMSNs) which are pH sensitive with core-shell structure to improve the tumor cell lethality of antitumor drug. The lipid coated mesoporous silica nanoparticles loaded with irinotecan (CPT-11) (CPT-11-LMSNs) were prepared by hot water-film hydration method, and the characterized its morphology, particle size and release in vitro. Meanwhile, the intracellular uptake and cell toxicity of CPT-11-LMSNs and intracellular accumulation of CPT-11 were evaluated on human breast carcinoma cell line (MCF-7). The results indicated that the mean diameter of the spherical LMSNs was (120.27 +/- 5.91) nm. The slow release in simulated normal physiological conditions and a rapid release under simulated intracellular condition demonstrated the pH sensitivity of CPT-11-MSNs in vitro. Moreover, the CPT-11-LMSN could improve the intracellular CPT-11 cumulant 2.1 times and reduce half maximal inhibitory concentration (IC50) values of CPT-11 1.4 times compared with CPT-11-MSNs, demonstrating a stronger cell lethality.
10.Ghrelin protects against hippocampal injury after global cerebral ischemia/reperfusion and regulate glutamic acid/γ-aminobutyric acid sensitive neuron discharge
Mengling ZHANG ; Xiangrong SUN ; Feifei GUO ; Yanling GONG ; Luo XU
Chinese Critical Care Medicine 2016;28(5):455-459
Objective To observe the protective effect of ghrelin on hippocampal injury induced by global cerebral ischemia/reperfusion (I/R) and explore its effect mechanisms.Methods The male Sprague-Dawley (SD) rats were randomly divided into four groups,namely sham group,I/R group,normal saline (NS)+I/R group and Ghrelin+I/R group,with 42 rats in each group.The model of I/R was reproduced by clipping bilateral carotid artery of rats 15 minutes and then releasing them for 60 minutes.There were no challenges for rats in sham group,just exposed their carotid artery.Ghrelin+I/R group and NS+I/R group were challenged by injecting 1 μ.L ghrelin or NS into lateral ventricle before I/R.Some of brain tissue in the rats was harvested after experiment to determine the levels of malonaldehyele (MDA),myeloperoxidase (MPO) and glutathione (GSH) in hippocampus by using chemical colorimetry and observe infarct sizes and histopathology.Single extracellular neuron discharge in other rats was recorded to observe the activity of glutamic sensitive neurons (Glu-N) and γ-aminobutyric acid (GABA) sensitive neurons (GABA-N) in hippocampus CA1 region of rats suffered I/R.Results Compared with sham group,the levels of MDA and MPO in hippocampus of rats in the I/R group were raised markedly,the level of GSH was decreased significantly,the infarct sizes was increased significantly and pycnosis neurons were increased markedly.All sorts of indexes between NS+I/R group and I/R group showed no significantly statistical significance.Compared with NS+I/R group,the levels of MDA and MPO in hippocampus of rats in the Ghrelin+I/R group were decreased significantly [MDA (nmol/g):16.4 ± 4.2 vs.24.5 ± 6.7,MPO (nmol/g):6.4 ± 1.8 vs.10.2 ± 2.9,both P < 0.05],the activity of GSH was risen remarkably (μmol/g:2.65 ± 0.72 vs.1.66 ± 0.50,P < 0.05),the infarct sizes of hippocampus were reduced markedly [(43.9 ± 9.5)% vs.(77.0 ± 12.7)%,P < 0.01],the number of pycnosis neuron was reduced markedly (cells:36.2±4.5 vs.47.1 ±6.1,P < 0.01).The results of electrophysiology showed that the discharge frequency of Glu-N and GABA-N in hippocampus CA1 region of rats in I/R group increased markedly as compared with sham group,and no significant difference in the discharge frequency of Glu-N and GABA-N between NS+I/R group and I/R group.Compared with NS+I/R group,injected ghrelin could make the discharge frequency of Glu-N in hippocampus CA1 region of rats decreased markedly (Hz:3.81 ±0.67 vs.4.98±0.33 at ischemia,3.01 ±0.37 vs.3.77 ± 0.41 at reperfusion,both P < 0.05),and the discharge frequency of GABA-N increased markedly (Hz:5.62 ± 0.54 vs.3.62±0.39 at ischemia,4.81±0.48 vs.3.71±0.21 at reperfusion,both P < 0.05).Conclusion Ghrelin might protect hippocampal neuron after I/R iniury,and neuron excitability decrease might be related.