Effect of insulin on 1-methyl-4-phenylpyridinium ion-induced apoptosis of PC12 cells

BACKGROUND： Insulin receptor （IR） expression in the substantia nigra of patients with Parkinson disease （PD） is not only significantly lower than that in the substantia nigra of normal persons of the same age, but also significantly lower than that in other regions in brain of himself/herself. It suggests that the abnormal effect of insulin receptor-mediated insulin, as a neurotrophic factor, is very possibly related to the loss of dopaminergic neurons in the substantia nigra and striatum in patients with Parkinson disease. OBJECTIVE ： TO observe the interventional effect of insulin on 1-methyl-4-phenylpyridinium ion （MPP^＋）-induced apoptosis of PC12. DESIGN： Controlled observation SETTINGS： Department of Neurology, Beijing China-Japan Friendship Hospital; Department of Neurology Huashan Hospital Affiliated to Fudan University. MATERIALS： PC12 cells were provided by the Cell Bank, Shanghai Institute of Cell Biology, Chinese Academy of Science. MPP^＋, MTT, HOECHST 33258 （Invitrogen Life Technologies）, reverse transcription-polymerase chain reaction （RT-PCR） reagent （Takara Shuzo Co., Ltd.）, flow cytometer （Bacton Dickionson, San Jose, CA）, enzyme labelling instrument （Bio-Tek, Winooski, VT） and PCR circulation instrument （Takara Shuzo Co., Ltd） were used in this study. METHODS ： This study was carried out in the Department of Neurology, Huashan Hospital Affiliated to Fudan University during June 2003 to August 2004. （1） Cell culture and experimental grouping： PC12 cells were cultured according to the method from Peng et al, then were randomized into 3 groups; blank control group, MPP^＋ group and insulin group. （2） Detection of relative survival rate of cells： The relative survival rate of cells at different MPP^＋ final concentrations （0, 50, 100, 200, 300, 1 000 μmol/L） and at different culture time （0, 4, 8, 12, 18, 24 hours） in the 300 Fmol/L MPP^＋ group and different concentrations of insulin （0, 15, 50, 100 nmol/L） in the insulin group was detected with MTT method according to the method from Hansen et al. （3） Observation of cell apoptosis： After stained by HOECHST 33258, the apoptotic cells were observed under the fluorescence miscroscope with the method from Chen et al. （4） Dection of apoptotic rate of cells： Apoptotic rate of cells was detected with flow cytometry according to the method from Zhang et al. （5） The expression of tyrosine hydroxylase （TH） mRNA in PC12 cells was detected with RT-PCR methods according to the modified method from Peng et al. MAIN OUTCOME MEASURES ： Comparison of relative survival rate, apoptosis rate, the expression of IR mRNA and TH mRNA and cell apoptosis. RESULTS： （1） After 12-hour incubation of 100, 200, 300 and 1 000 μmol/L MPP^＋, the relative survival rate of PC12 cells was （72.88±2.91）%, （60.64±0.81）%, （54.56±0.76）% and （16.89±2.83）%, respectively, which was significantly lower than that of blank control group （100%, P 〈 0.05）; After 12, 18 and 24-hour incubation, the relative survival rate of PC12 cells was （54.56±0.76）%, （42.43±0.16）% and （23.56±0.17）% respectively, which was significantly lower than that of blank control group （100%, P〈 0.05）; When 15, 50 and 100 nmol/L insulin was pre-added to cells, the relative survival rate was （70.10±0.16）%, （78.01 ±2.43）% and （83.55±1.43）%, respectively, which was significantly higher than MPP^＋ alone [（54.56±0.76）%, P 〈 0.05]. （2） Appototic bodies were rarely seen in the blank control group, but densely gathered in the MPP^＋ group and were significantly decreased in the insulin group. （3） Apoptosis rate of PC12 cells in the MPP^＋ group was significantly higher than that in the blank control group [（36.56±0.89）% vs. （2.34±0.23）%, P〈 0.05], and that in the 15, 50, 100 nmol/L insulin group [（30.01±0.04）%, （24.23±0.37）%, （20.01 ±1.01）%, respectivelyl was significantly lower than that in MPP^＋ group （P 〈 0.05）. （4） The TH mRNA expression in PC12 cells in MPP^＋ group was significantly lower than that in blank control group; The expression of TH mRNA in insulin group was gradually increased in an insulin dose-dependent manner. There were no significant changes in the expression of IR mRNA under different experimental conditions. CONCLUSION： Insulin can resist MPP^＋-induced apoptosis of PC12 cells, lessen the damage of PC12 cells, but does not change the gene expression of target cell insulin receptor.

Numerical simulation of blood flow and interstitial fluid pressure in solid tumor microcirculation based on tumor-induced angiogenesis

A coupled intravascular-transvascular-interstitial fluid flow model is developed to study the distributions of blood flow and interstitial fluid pressure in solid tumor microcirculation based on a tumor-induced microvascular network. This is generated from a 2D nine-point discrete mathematical model of tumor angiogenesis and contains two parent vessels. Blood flow through the microvascular network and interstitial fluid flow in tumor tissues are performed by the extended Poiseuille＇s law and Darcy＇s law, respectively, transvascular flow is described by Starling＇s law; effects of the vascular permeability and the interstitial hydraulic conductivity are also considered. The simulation results predict the heterogeneous blood supply, interstitial hypertension and low convection on the inside of the tumor, which are consistent with physiological observed facts. These results may provide beneficial information for anti-angiogenesis treatment of tumor and further clinical research.

Effect of Exogenous Spermidine Concentration on Chilling Tolerance in Cucumber

Chilling stress was one of the most sever abiotic stress to restrict cucumber plant growth.The effects of different concentrations of spermidine( 0.1,0.5,1 and 5 mM) on photosynthetic characteristics,antioxidant( catalase,ascorbate peroxidase,superoxide dismutase and peroxidase) enzyme activities,malondialdehyde( MDA) content,electrolyte leakage and H_2 O_2 content of cucumber seedlings under chilling stress were studied.The results showed that chilling stress reduced photosynthetic capacity and the value of the maximal photochemical efficiency of PSII( Fv/Fm),and increased electrolyte leakage and the content of MDA and H_2 O_2.Exogenous Spd application led to a tendency of photosynthetic characteristics and antioxidant enzyme activities to first increase and then decrease with the concentration of exogenous Spd increasing.Furthermore,electrolyte leakage and the contents of MDA and H_2 O_2 significantly decreased in plants treated with Spd.Results of this study suggest that exogenous Spd can improve cucumber tolerance to chilling stress,and the optimal concentration of Spd to alleviate chilling stress in cucumber was 0.5 mM in the present study.

Al-induced proteomics changes in tomato plants over-expressing a glyoxalase I gene

Glyoxalase I(Gly I)is the first enzyme in the glutathionine-dependent glyoxalase pathway for detoxification of methylglyoxal(MG)under stress conditions.Transgenic tomato‘Money Maker’plants overexpressing tomato SlGlyI gene(tomato unigene accession SGN-U582631/Solyc09g082120.3.1)were generated and homozygous lines were obtained after four generations of self-pollination.In this study,SlGlyI-overepxressing line(GlyI),wild type(WT,negative control)and plants transformed with empty vector(ECtr,positive control),were subjected to Al-treatment by growing in Magnavaca’s nutrient solution(pH 4.5)supplemented with 20μM Al3+ion activity.After 30 days of treatments,the fresh and dry weight of shoots and roots of plants from Al-treated conditions decreased significantly compared to the non-treated conditions for all the three lines.When compared across the three lines,root fresh and dry weight of GlyI was significant higher than WT and ECtr,whereas there was no difference in shoot tissues.The basal 5mm root-tips of GlyI plants expressed a significantly higher level of glyoxalase activity under both non-Al-treated and Al-treated conditions compared to the two control lines.Under Al-treated condition,there was a significant increase in MG content in ECtr and WT lines,but not in GlyI line.Quantitative proteomics analysis using tandem mass tags mass spectrometry identified 4080 quantifiable proteins and 201 Al-induced differentially expressed proteins(DEPs)in roottip tissues from GlyI,and 4273 proteins and 230 DEPs from ECtr.The Al-down-regulated DEPs were classified into molecular pathways of gene transcription,RNA splicing and protein biosynthesis in both GlyI and ECtr lines.The Alinduced DEPs in GlyI associated with tolerance to Al3+and MG toxicity are involved in callose degradation,cell wall components(xylan acetylation and pectin degradation),oxidative stress(antioxidants)and turnover of Al-damaged epidermal cells,repair of damaged DNA,epigenetics,gene transcription,and protein translation.A protein–protein association network was constructed to aid the selection of proteins in the same pathway but differentially regulated in GlyI or ECtr lines.Proteomics data are available via ProteomeXchange with identifiers PXD009456 under project title‘25Dec2017_Suping_XSexp2_ITAG3.2’for SlGlyI-overexpressing tomato plants and PXD009848 under project title‘25Dec2017_Suping_XSexp3_ITAG3.2’for positive control ECtr line transformed with empty vector.

Petrogenesis and Tectonic Implications of the Paleoproterozoic A-Type Granites in the Xiong’ershan Area along the Southern Margin of the North China Craton

Paleoproterozoic A-type granites are widely distributed in the southern margin of the North China Craton(SNCC),providing important information for understanding the Paleoproterozoic tectonic regimes in this area.This paper reports newly obtained whole-rock compositions and zircon U-Pb ages for the Tieluping syenogranite porphyry(TLP)and Huoshenmiao alkali granite porphyry(HSM)in the SNCC.Zircons from the TLP and HSM have U-Pb ages of 1805±12 and 1792±14 Ma,respectively.These ages are taken to date the emplacement of these intrusions.They had high total alkali contents(K_(2)O+Na_(2)O>7.13 wt.%),with high 10000×Ga/Al ratios(3.06–3.41)and Zr+Y+Nb+Ce values(709 ppm–910 ppm)as well as high zircon saturation temperatures(864–970℃),indicative of A-type granite affinities.High Y/Nb(1.75–3.32),Ce/Nb(7.72–9.72),and Yb/Ta(2.89–5.60)ratios suggested that TLP and HSM belonged to the A2-type granite.The negative whole rockε_(Nd)(t)values(−8.4 to−6.6)and negative zirconε_(Hf)(t)values(−15.9 to−6.3)confirmed that TLP and HSM were likely generated by the partial melting of an ancient continental crust.TheεHf(t)(−7.4 to+4.0)values of inherited zircons in the TLP suggested that they were derived from the partial melting of Archean basement rocks.Considering the geochemical similarity of the 1.80 Ga A-type granitoids in the SNCC,we propose that the TLP and HSM were formed in a post-collisional regime that was likely associated with the break-off of the Paleoproterozoic subducted slab.Upwelling of the asthenosphere provided huge heat to generate the regional 1.80 Ga A-type granite in the SNCC.

Plant-inspired visible-light-driven bioenergetic hydrogels for chronic wound healing

Chronic bioenergetic imbalances and inflammation caused by hyperglycemia are obstacles that delay diabetic wound healing.However,it is difficult to directly deliver energy and metabolites to regulate intracellular energy metabolism using biomaterials.Herein,we propose a light-driven bioenergetic and oxygen-releasing hydrogel(PTKM@HG)that integrates the thylakoid membrane-encapsulated polyphenol nanoparticles(PTKM NPs)to regulate the energy metabolism and inflammatory response in diabetic wounds.Upon red light irradiation,the PTKM NPs exhibited oxygen generation and H2O2 deletion capacity through a photosynthetic effect to restore hypoxia-induced mitochondrial dysfunction.Meanwhile,the PTKM NPs could produce exogenous ATP and NADPH to enhance mitochondrial function and facilitate cellular anabolism by regulating the leucine-activated mTOR signaling pathway.Furthermore,the PTKM NPs inherited antioxidative and anti-inflammatory ability from polyphenol.Finally,the red light irradiated PTKM@HG hydrogel augmented the survival and migration of cells keratinocytes,and then accelerated angiogenesis and re-epithelialization of diabetic wounds.In short,this study provides possibilities for effectively treating diseases by delivering key metabolites and energy based on such a light-driven bioenergetic hydrogel.

“Block and attack”strategy for tumor therapy through ZnO_(2)/siRNA/NIR-mediating Zn^(2+)-overload and amplified oxidative stress

Intracellular zinc ion(Zn^(2+))accumulation disrupts the Zn^(2+)homeostasis,providing an ion-overloading anticancer strategy with great potential.The self-adaptation of tumor cells to ion concentration,however,puts forward higher requirements for the design of ion-overloading strategy.Herein,“block and attack”antitumor strategy was applied through a composite nanomaterials(UHSsPZH NPs).The strategy demonstrated powerful ion interference ability through both“blocking”the efflux of excess Zn^(2+)via gene silencing and“attacking”tumor cells via target delivery of ZnO_(2).After cellular internalization,ZnO_(2) was degraded to Zn^(2+)and hydrogen peroxide(H_(2)O_(2)),and the gene expression of zinc transporter 1(ZnT1)was silenced by targeting of released siRNA,which together caused intracellular Zn2+-overload.Disorder of Zn^(2+)further interfered with intracellular Ca^(2+)homeostasis,inhibited the electron transport chain and promoted the production of endogenous reactive oxygen species(ROS),which assisted the“attack”to tumor cells together with the exogenous ROS generated by UHSsPZH NPs under 980 nm laser irradiation.In summary,this work supplies a“block and attack”strategy for the application of ion homeostasis interference in tumor therapy.