Growth differentiation factor 11 promotes macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway

Background:Myocardial infarctions(MI)is a major threat to human health especially in people exposed to cold environment.The polarization of macrophages towards different functional phenotypes(M1 macrophages and M2 macrophages)is closely related to MI repairment.The growth differentiation factor 11(GDF11)has been reported to play a momentous role in inflammatory associated diseases.In this study,we examined the regulatory role of GDF11 in macrophage polarization and elucidated the underlying mechanisms in MI.Methods:In vivo,the mice model of MI was induced by permanent ligation of the left anterior descending coronary artery(LAD),and mice were randomly divided into the sham group,MI group,and MI+GDF11 group.The protective effect of GDF11 on myocardial infarction and its effect on macrophage polarization were verified by echocardiography,triphenyl tetrazolium chloride staining and immunofluorescence staining of heart tissue.In vitro,based on the RAW264.7 cell line,the effect of GDF11 in promoting macrophage polarization toward the M2 type by inhibiting the Notch1 Signaling pathway was validated by qRT-PCR,Western blot,and flow cytometry.Results:We found that GDF11 was significantly downregulated in the cardiac tissue of MI mice.And GDF11 supplementation can improve the cardiac function.Moreover,GDF11 could reduce the proportion of M1 macrophages and increase the accumulation of M2 macrophages in the heart tissue of MI mice.Furthermore,the cardioprotective effect of GDF11 on MI mice was weakened after macrophage clearance.At the cellular level,application of GDF11 could inhibit the expression of M1 macrophage(classically activated macrophage)markers iNOS,interleukin(IL)-1β,and IL-6 in a dose-dependent manner.In contrast,GDF11 significantly increased the level of M2 macrophage markers including IL-10,CD206,arginase 1(Arg1),and vascular endothelial growth factor(VEGF).Interestingly,GDF11 could promote M1 macrophages polarizing to M2 macrophages.At the molecular level,GDF11 significantly down-regulated the Notch1 signaling pathway,the activation of which has been demonstrated to promote M1 polarization in macrophages.Conclusions:GDF11 promoted macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway.

Neurotrophic factors: from neurodevelopmental regulators to novel therapies for Parkinson's disease

Neuroprotection and neuroregeneration are two of the most promising disease-modifying ther- apies for the incurable and widespread Parkinson＇s disease. In Parkinson＇s disease, progressive degeneration of nigrostriatal dopaminergic neurons causes debilitating motor symptoms. Neurotrophic factors play important regulatory roles in the development, survival and maintenance of specific neuronal populations. These factors have the potential to slow down, halt or reverse the loss of nigrostriatal dopaminergic neurons in Parkinsoffs disease. Several neurotrophic fac- tors have been investigated in this regard. This review article discusses the neurodevelopmental roles and therapeutic potential of three dopaminergic neurotrophic factors： glial cell line-derived neurotrophic factor, neurturin and growth/differentiation factor 5.

Porcine growth differentiation factor 9 gene polymorphisms and their associations with litter size

Growth differentiation factor 9 （GDF9） is expressed in oocytes and is thought to be required for ovarian folliculogenesis. Given this function, GDF9 may be considered as a candidate gene controlling pig ovulate rate. In this study, the complete coding sequence was cloned （encoding a 444 amino acid）, intron sequence and partial 5＇-UTR of pig GDF9. RT-PCR results showed that GDF9 mRNA is expressed in a wide range of tissues of the ruttish Erhualian pig. The expression levels of GDF9 mRNA in pituitary, ovary, uterus and oviduct are higher in the Erhualian pigs than those in Duroc pigs, especially in pituitary with a significant difference （P 〈 0.05）. Comparative sequencing revealed 12 polymorphisms, including 8 single nucleotide polymorphisms （SNPs） and one 314 bp indel in noncoding regions, and the other 3 SNPs in coding regions. Four polymorphisms, G359C, C1801T, T1806C and 314 bp indel, were developed as markers for further use in population variation and association studies. The G359C polymorphism segregates only in Chinese native pigs, Erhualian and Dahuabai, on the contrary, 314 bp indel segregates only in Duroc and Landrace. C1801T and T1806C sites seem to be completely linked and segregate in Erhualian, Dahuabai and Landrace. In a word, GDF9 may be not associated with pig litter size in extensive populations as per the studies of allele distributions of the four polymorphisms and pilot association in four breeds.

Significance of 125I radioactive seed implantation on growth differentiation factor and programmed death receptor-1 during treatment of oral cancer

BACKGROUND Oral cancer(OC)is the most common malignant tumor in the oral cavity,and is mainly seen in middle-aged and elderly men.At present,OC is mainly treated clinically by surgery or combined with radiotherapy and chemotherapy;but recently,more and more studies have shown that the stress trauma caused by surgery and the side effects of radiotherapy and chemotherapy seriously affect the prognosis of patients.AIM To determine the significance of 125I radioactive seed implantation on growth differentiation factor 11(GDF11)and programmed death receptor-1(PD-1)during treatment of OC.METHODS A total of 184 OC patients admitted to The Second Affiliated Hospital of Jiamusi University from May 2015 to May 2017 were selected as the research subjects for prospective analysis.Of these patients,89 who received 125I radioactive seed implantation therapy were regarded as the research group(RG)and 95 patients who received surgical treatment were regarded as the control group(CG).The clinical efficacy,incidence of adverse reactions and changes in GDF11 and PD-1 before treatment(T0),2 wk after treatment(T1),4 wk after treatment(T2)and 6 wk after treatment(T3)were compared between the two groups.RESULTS The efficacy and recurrence rate in the RG were better than those in the CG(P<0.05),while the incidence of adverse reactions and survival rate were not different.There was no difference in GDF11 and PD-1 between the two groups at T0 and T1,but these factors were lower in the RG than in the CG at T2 and T3(P<0.05).Using receiver operating characteristic(ROC)curve analysis,GDF11 and PD-1 had good predictive value for efficacy and recurrence(P<0.001).CONCLUSION 125I radioactive seed implantation has clinical efficacy and can reduce the recurrence rate in patients with OC.This therapy has marked potential in clinical application.The detection of GDF11 and PD-1 in patients during treatment showed good predictive value for treatment efficacy and recurrence in OC patients,and may be potential targets for future OC treatment.

Growth differentiation factor 5:a neurotrophic factor with neuroprotective potential in Parkinson’s disease

Parkinson’s disease is the most common movement disorder worldwide,affecting over 6 million people.It is an age-related disease,occurring in 1%of people over the age of 60,and 3%of the population over 80 years.The disease is characterized by the progressive loss of midbrain dopaminergic neurons from the substantia nigra,and their axons,which innervate the striatum,resulting in the characteristic motor and non-motor symptoms of Parkinson’s disease.This is paralleled by the intracellular accumulation ofα-synuclein in several regions of the nervous system.Current therapies are solely symptomatic and do not stop or slow disease progression.One promising disease-modifying strategy to arrest the loss of dopaminergic neurons is the targeted delivery of neurotrophic factors to the substantia nigra or striatum,to protect the remaining dopaminergic neurons of the nigrostriatal pathway.However,clinical trials of two well-established neurotrophic factors,glial cell line-derived neurotrophic factor and neurturin,have failed to meet their primary end-points.This failure is thought to be at least partly due to the downregulation byα-synuclein of Ret,the common co-receptor of glial cell line-derived neurorophic factor and neurturin.Growth/differentiation factor 5 is a member of the bone morphogenetic protein family of neurotrophic factors,that signals through the Ret-independent canonical Smad signaling pathway.Here,we review the evidence for the neurotrophic potential of growth/differentiation factor 5 in in vitro and in vivo models of Parkinson’s disease.We discuss new work on growth/differentiation factor 5’s mechanisms of action,as well as data showing that viral delivery of growth/differentiation factor 5 to the substantia nigra is neuroprotective in theα-synuclein rat model of Parkinson’s disease.These data highlight the potential for growth/differentiation factor 5 as a disease-modifying therapy for Parkinson’s disease.

Elevated serum growth differentiation factor 15 in multiple system atrophy patients:A case control study

BACKGROUND Multiple system atrophy(MSA) is a serious progressive neurodegenerative disease. Early diagnosis of MSA is very difficult, and diagnostic biomarkers are limited. Growth differentiation factor 15(GDF15) is involved in the differentiation and progression of the central nervous system, and is widely distributed in peripheral blood, which may be a novel biomarker for MSA.AIM To determine serum GDF15 levels, related factors and their potential diagnostic value in MSA patients, compared with Parkinson’s disease(PD) patients and healthy controls.METHODS A case-control study was conducted, including 49 MSA patients, 50 PD patients and 50 healthy controls. Serum GDF15 levels were measured by human enzymelinked immunosorbent assay, and the differences between the MSA, PD and control groups were analyzed. Further investigations were performed in different MSA subgroups according to age of onset, sex, clinical subtypes, diagnostic criteria, and disease duration. Receiver-operating characteristic curve analysiswas used to evaluate the diagnostic value of GDF15, especially for the differential diagnosis between MSA and PD.RESULTS Serum GDF15 levels were significantly higher in MSA patients than in PD patients and healthy controls(P = 0.000). Males and those with a disease duration of more than three years showed higher serum GDF15 levels(P = 0.043 and 0.000;respectively). Serum GDF15 levels may be a potential diagnostic biomarker for MSA patients compared with healthy controls and PD patients(cutoff: 470.42 pg/m L, sensitivity: 85.7%, specificity: 88.0%;cutoff: 1075.91 pg/m L, sensitivity:51.0%, specificity: 96.0%;respectively).CONCLUSION Serum GDF15 levels are significantly higher in MSA patients and provide suggestions on the etiology of MSA.

Denervated hippocampus provides a favorable microenvironment for neuronal differentiation of endogenous neural stem cells

Fimbria-fornix transection induces both exogenous and endogenous neural stem cells to differentiate into neurons in the hippocampus.This indicates that the denervated hippocampus provides an environment for neuronal differentiation of neural stem cells.However,the pathways and mechanisms in this process are still unclear.Seven days after fimbria fornix transection,our reverse transcription polymerase chain reaction,western blot assay,and enzyme linked immunosorbent assay results show a significant increase in ciliary neurotrophic factor m RNA and protein expression in the denervated hippocampus.Moreover,neural stem cells derived from hippocampi of fetal（embryonic day 17） Sprague-Dawley rats were treated with ciliary neurotrophic factor for 7 days,with an increased number of microtubule associated protein-2-positive cells and decreased number of glial fibrillary acidic protein-positive cells detected.Our results show that ciliary neurotrophic factor expression is up-regulated in the denervated hippocampus,which may promote neuronal differentiation of neural stem cells in the denervated hippocampus.

DIFFERENTIATION AND MALIGNANT SUPPRESSION INDUCED BY MOUSE ERYTHROID DIFFERENTIATION AND DENUCLEATION FACTOR ON MOUSE ERYTHROLEUKEMIA CELLS

Objective. To investigate the roles of mouse erythroid differentiation and denucleation factor (MKI)DF), a novel factor cloned in our laboratory recently, in erylhroid terminal differentiation.Method. Mouse erythroleukemia (MEL) cells were transfected with eukaryotie expression plasinid pcl)-NA-MEDDF. Then we investigated the changes on characteristics of cell growth by analyzing cells growth rate, mitotie index and colony-forming rate in semi-solid medium. The expressions of c-mye and p-globin genes were analysed by semi-quantitative RT-PCR.Results. MEL cells transfected with pcDNA-MEDDF showed significant lower growth rate, mitolic index,and colony-forming rate in semi-solid medium ( P<0. 01). The percentage of benzidine-positive cells was 32. 8%after transfection. The expression of β-globin in cells trarisfected with pcDNA-MEDDF was 3. 43 times higherthan that of control (MEL transfected with blank vector, pcDNA3. 1), and the expression of c-rnyc decreased by66. 3% .Conclusions. MEDDF can induce differentiation of MEL cell and suppress its malignancy.

Growth differentiation factor 15 as an emerging novel biomarker in SARS-CoV-2 infection

BACKGROUND Growth differentiation factor(GDF)-15 is a member of a transforming growth factor-βcytokine superfamily that regulates metabolism and is released in response to inflammation,hypoxia and tissue injury.It has evolved as one of the most potent cytokines for predicting the severity of infections and inflammatory conditions,such as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection.AIM To investigate the utility of GDF-15 in predicting the severity of SARS-CoV-2 infection.METHODS PubMed,Reference Citation Analysis,CNKI,and Goggle Scholar were explored by using related MeSH keywords and data such as the first author’s name,study duration,type and place of study,sample size and subgroups of participants if any,serum/plasma GDF-15 level in pg/mL,area under the curve and cut-off value in receiver operating characteristic analysis,method of measurement of GDF-15,and the main conclusion were extracted.RESULTS In all studies,the baseline GDF-15 level was elevated in SARS-CoV-2-infected patients,and it was significantly associated with severity,hypoxemia,viral load,and worse clinical consequences.In addition,GDF-15 levels were correlated with C-reactive protein,D-dimer,ferritin and procalcitonin,and it had superior discriminatory ability to detect severity and in-hospital mortality of SARS-CoV-2 infection.Hence,GDF-15 might be used to predict the severity and prognosis of hospitalized patients with SARS-CoV-2.CONCLUSION Serial estimation of GDF-15 levels in hospitalized patients with SARS-CoV-2 infection appeared to have useful prognostic value and GDF-15 can be considered a clinically prominent sepsis biomarker for SARS-CoV-2 infection.

Chondrogenic differentiation of human bone mesenchymal stem cells treated with growth differentiation factor 5 under hypoxia

Objective To explore the feasibility and effectiveness of the self-assembly cartilage tissue engineered with chondrogenically differentiated human bone mesenchymal stem cells (hBMCs) induced by growth differentiation factor-5 (GDF-5)

Synergistic effects of brain-derived neurotrophic factor and retinoic acid on inducing the differentiation of bone marrow stromal cells into neuron-like cells in adult rats in vitro

BACKGROUND： Under induction of retinoic acid （RA）, bone marrow stromal cells （BMSCs） can differentiate into nerve cells or neuron-like cells, which do not survive for a long time, so those are restricted to an application. Other neurotrophic factors can also differentiate into neuronal cells through inducing BMSCs; especially, brain-derived neurotrophic factor （BDNF） can delay natural death of neurons and play a key role in survival and growth of neurons. The combination of them is beneficial for differentiation of BMSCs. OBJECTIVE： To investigate the effects of BDNF combining with RA on inducing differentiation of BMSCs to nerve cells of adult rats and compare the results between common medium group and single BDNF group. DESIGN： Randomized controlled animal study SETTING： Department of Neurology, Affiliated Hospital of Xuzhou Medical College MATERIALS： The experiment was carried out in the Clinical Neurological Laboratory of Xuzhou Medical College from September 2003 to April 2005. A total of 24 SD rats, of either gender, 2 months old, weighing 130-150 g, were provided by Experimental Animal Center of Xuzhou Medical College [certification： SYXK （su） 2002-0038]. Materials and reagents： low-glucose DMEM medium, bovine serum, BDNF, RA, trypsin, separating medium of lymphocyte, monoclonal antibody of mouse-anti-nestin, neuro-specific enolase, glial fibrillary acidic protein （GFAP） antibody, SABC kit, and diaminobenzidine （DAB） color agent. All these mentioned above were mainly provided by SIGMA Company, GIBCO Company and Boshide Company. METHODS： Bone marrow of SD rats was selected for density gradient centrifugation. BMSCs were undertaken primary culture and subculture; and then, those cells were induced respectively in various mediums in total of 3 groups, including control group （primary culture）, BDNF group （20 μg/L BDNF） and BDNF＋RA group （20 μg/L BDNF plus 20 μg/L RA）. On the 3^rd and the 7^th days after induction, BMSCs were stained immunocytochemically with nestin （sign of nerve stem cells）, neuron-specific enolase （NSE, sign of diagnosing neurons） and GFAP （diagnosing astrocyte）, and evaluated cellular property. MAIN OUTCOME MEASURES ： Induction and differentiation in vitro of BMSCs in 3 groups RESULTS： （1） Induction and differentiation of BMSCs： Seven days after induction, cells having 2 or more apophyses were observed. Soma shaped like angle or erose form, which were similar to neurons and glial cells having strong refraction. （2） Results of immunocytochemical detection： Three days after induction, rate of positive cells in BDNF＋RA group was higher than that in BDNF group and control group [（86.15±4.58）%, （65.43±4.23）%, （4.18±1.09）%, P 〈 0.01]. Seven days after induction, rate of positive cells was lower in BDNF group and BDNF＋RA group than that in both groups at 3 days after induction [（31.12±3.18）%, （29.35±2.69）%, P 〈 0.01]; however, amounts of positive cells of NSE and GFAP were higher than those at 3 days after induction （P 〈 0.01）; meanwhile, the amount in BDNF＋RA group was remarkably higher than that in BDNF group （P 〈 0.01）. CONCLUSION： Combination of BDNF and RA can cooperate differentiation of BMSCs into neurons and astrocyte, and the effect is superior to single usage of BDNF.

Protective effect of modified Huangqi Chifeng decoction(加味黄芪赤风汤)on immunoglobulin A nephropathy through toll-like receptor 4/myeloid differentiation factor 88/nuclear factor-kappa B signaling pathway

OBJECTIVE:To examine the nephroprotective mechanism of modified Huangqi Chifeng decoction(加味黄芪赤风汤,MHCD)in immunoglobulin A nephropathy(IgAN)rats.METHODS:To establish the IgAN rat model,the bovine serum albumin,lipopolysaccharide,and carbon tetrachloride 4 method was employed.The rats were then randomly assigned to the control,model,telmisartan,and high-,medium-,and low-dose MHCD groups,and were administered the respective treatments via intragastric administration for 8 weeks.The levels of 24-h urinary protein,serum creatinine(CRE),and blood urea nitrogen(BUN)were measured in each group.Pathological alterations were detected.IgA deposition was visualized through the use of immunofluorescence staining.The ultrastructure of the kidney was observed using a transmission electron microscope.The expression levels of interleukin-6(IL-6),monocyte chemoattractant protein-1(MCP-1),and transforming growth factor-β1(TGF-β1)were examined by immunohistochemistry and quantitative polymerase chain reaction.Levels of toll-like receptor 4(TLR4),myeloid differentiation factor 88(MyD88),and nuclear factor-kappa B(NF-κB)P65,were examined by immunohistochemistry,Western blotting,and quantitative polymerase chain reaction.RESULTS:The 24-h urine protein level in each group increased significantly at week 6,and worsen from then on.But this process can be reversed by treatments of telmisartan,and high-,medium-,and low-dose of MHCD,and these treatments did not affect renal function.Telmisartan,and high-,and medium-dose of MHCD reduced IgA deposition.Renal histopathology demonstrated the protective effect of high-,medium-,and low-dose of MHCD against kidney injury.The expression levels of MCP-1,IL-6,and TGF-β1 in kidney tissues were downregulated by low,medium and high doses of MHCD treatment.Additionally,treatment of low,medium and high doses of MHCD decreased the protein and mRNA levels of TLR4,MyD88,and NF-κB.CONCLUSIONS:MHCD exerted nephroprotective effects on IgAN rats,and MHCD regulated the expressions of key targets in TLR4/MyD88/NF-κB signaling pathway,thereby alleviating renal inflammation by inhibiting MCP-1,IL-6 expressions,and ameliorating renal fibrosis by inhibiting TGF-β1 expression.

Taohong Siwu decoction(桃红四物汤)ameliorates atherosclerosis in rats possibly through toll-like receptor 4/myeloid differentiation primary response protein 88/nuclear factor-κB signal pathway

OBJECTIVE:To investigate the effect of Taohong Siwu decoction(桃红四物汤,TSD)on atherosclerosis in rats as well as investigate the underlying mechanism based on molecular docking.METHODS:Sixty healthy male Sprague-Dawley rats were randomly divided into 6 groups with 10 rats in each group:control group,model group,atorvastatin group(AT,2.0 mg/kg),and TSD groups(20,10,5 g/kg)after 7 d of acclimation.The model of atherosclerosis was successfully established except the control group by high fat diet(HFD)and vitamin D2.Biochemical analyzers were used to detect the levels of triglyceride(TG),total cholestero(TC),low density lipoprotein-cholesterol(LDLC)and high density lipid-cholesterol(HDL-C)in blood lipid.The levels of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and interleukin-1β(IL-1β)were determined by enzyme-linked immunosorbent assay.Sudan IV staining and Hematoxylin and eosin staining(HE staining)were performed to observe the pathological changes in aortic tissue.Molecular docking technology was used to predict the best matching between the main components of TSD and the target proteins.The expression of target proteins was further detected by quantitative real time polymerase chain reaction(q RTPCR)and Western blot analysis.RESULTS:The results showed that TSD restricted atherosclerosis development and decreased the inflammatory cytokines in plasma.Molecular docking results predicted that the main components of TSD showed a strong binding ability with toll-like receptor(TLR4),myeloid differentiation primary response protein 88(My D88),and nuclear factor kappa-B(NF-κB).The results of q RT-PCR and Western blot analysis showed that the m RNA and protein expressions of TLR4,My D88 and NF-κB p65 in the aorta were reduced in atorvastatin group and TSD group.CONCLUSIONS:TSD can ameliorate atherosclerosis in rats,and the underlying mechanism is supposed be related to the suppression of inflammatory response by regulating TLR4/My D88/NF-κB signal pathway.

Association between plasma growth differentiation factor 15 levels and pre-eclampsia in China

Background Growth differentiation factor-15(GDF-15)is a stress response protein and is related to cardiovascular diseases(CVD).This study aimed to investigate the association between GDF-15 and pre-eclampsia(PE).Method The study involved 299 pregnant women,out of which 236 had normal pregnancies,while 63 participants had PE.Maternal serum levels of GDF-15 were measured by using enzyme-linked immunosorbent assay kits and then translated into multiple of median(MOM)to avoid the influence of gestational week at blood sampling.Logistic models were performed to estimate the association between GDF-15 MOM and PE,presenting as odd ratios(ORs)and 95%confidence intervals(CIs).Results MOM of GDF-15 in PE participants was higher compared with controls(1.588 vs.1.000,p<0.001).In the logistic model,pregnant women with higher MOM of GDF-15(>1)had a 4.74-fold(95%CI=2.23–10.08,p<0.001)increased risk of PE,adjusted by age,preconceptional body mass index,gravidity,and parity.Conclusions These results demonstrated that higher levels of serum GDF-15 were associated with PE.GDF-15 may serve as a biomarker for diagnosing PE.

Puerarin protects brain tissue against cerebral ischemia/reperfusion injury by inhibiting the inflammatory response

Puerarin, a traditional Chinese medicine, exerts a powerful neuroprotective effect in cerebral ischemia/reperfusion injury, but its mechanism is unknown. Here, we established rat models of middle cerebral artery ischemia/reperfusion injury using the suture method. Puerarin （100 mg/kg） was administered intraperitoneally 30 minutes before middle cerebral artery occlusion and 8 hours after reperfusion. Twenty-four hours after reperfusion, we found that puerarin significantly improved neurological deficit, reduced infarct size and brain water content, and notably diminished the expression of Toll-like receptor-4, myeloid differentiation factor 88, nuclear factor kappa B and tumor necrosis factor-α in the ischemic region. These data indicate that puerarin exerts an anti-inflammatory protective effect on brain tissue with ischemia/reperfusion damage by downregulating the expression of multiple inflammatory factors.

GDF-15 Level Correlates with CMKLR1 and VEGF-A in Tumor-free Margin in Colorectal Cancer

Colorectal cancer(CRC)is the third most frequently diagnosed cancer worldwide,responsible for over 880000 deaths each year.Growth/differentiation factor 15(GDF-15)is reported to be a promising diagnostic and prognostic factor in CRC.It induces pleiotropic effects in tumor cells:proliferation,sternness,invasion and metastasis.Some studies indicate that GDF-15 may stimulate angiogenesis in malignant neoplasms.However,it has not been investigated in CRC yet.The aim of our study was to determine the level of GDF-15 and the concentrations of hypoxia-inducible factor-la(HIF-1α),VEGF-A and chemokine-like receptor 1(CMKLR1)in tumor and margin specimens of CRC in relation to histological grade and TNM staging.The study comprised 33 samples of tumor and margin tissues obtained from CRC patients.To assess the concentration of GDF-15,HIF-1α,VEGF-A and CMKLR1,commercially available enzyme-linked immunosorbent assay(ELISA)kits were used.We found significantly increased levels of GDF-15 and CMKLR1 in tumor tissue compared to margin tissue and higher concentrations of HIF-1α and VEGF-A in margin tissue than in tumor tissue.The levels of GDF-15 and HIF-1α were significantly correlated with VEGF-A and CMKLR1 in margin tissue.In CRC,the increased level of GDF-15 might stimulate angiogenesis through upregulation of HIF-1α,VEGF A and CMKLR1 expression.Our study is the first one to reveal the correlation between the levels of GDF-15 and CMKLR1 in CRC.The elevated levels of HIF-1α and VEGF-A in tumor-free margin tissues suggest that noncancer cells in the tumor microenvironment are an important source of proangiogenic factors.

An algorithm and its application for obtaining some kind of infinite-dimensional Hamiltonian canonical formulation

Using factorization viewpoint of differential operator, this paper discusses how to transform a nonlinear evolution equation to infinite-dimensional Hamiltonian linear canonical formulation. It proves a sufficient condition of canonical factorization of operator, and provides a kind of mechanical algebraic method to achieve canonical ＇σ/σx＇-type expression, correspondingly. Then three examples are given, which show the application of the obtained algorithm. Thus a novel idea for inverse problem can be derived feasibly.

Construction of Self-Assembled Cartilage Tissue from Bone Marrow Mesenchymal Stem Cells Induced by Hypoxia Combined with GDF-5

It is widely known that hypoxia can promote chondrogenesis of human bone marrow de- rived mesenchymal stem cells （hMSCs） in monolayer cultures. However, the direct impact of oxygen tension on hMSC differentiation in three-dimensional cultures is still unknown. This research was de- signed to observe the direct impact of oxygen tension on the ability of hMSCs to ＂self assemble＂ into tissue-engineered cartilage constructs, hMSCs were cultured in chondrogenic medium （CM） containing 100 ng/mL growth differentiation factor 5 （GDF-5） at 5% （hypoxia） and 21% （normoxia） 02 levels in monolayer cultures for 3 weeks. After differentiation, the cells were digested and employed in a self- assembly process to produce tissue-engineered constructs under hypoxic and normoxic conditions in vi- tro. The aggrecan and type ]I collagen expression, and type X collagen in the self-assembled con- structs were assessed by using immunofluorescent and immunochemical staining respectively. The methods of dimethylmethylene blue （DMMB）, hydroxyproline and PicoGreen were used to measure the total collagen content, glycosaminoglycan （GAG） content and the number of viable cells in each con- struct, respectively. The expression of type II collagen and aggrecan under hypoxic conditions was in- creased significantly as compared with that under normoxic conditions. In contrast, type X collagen expression was down-regulated in the hypoxic group. Moreover, the constructs in hypoxic group showed more significantly increased total collagen and GAG than in normoxic group, which were more close to those of the natural cartilage. These findings demonstrated that hypoxia enhanced chondro- genesis of in vitro, scaffold-free, tissue-engineered constructs generated using hMSCs induced by GDF-5. In hypoxic environments, the self-assembled constructs have a Thistological appearance and biochemical parameters similar to those of the natural cartilage.

Expression of OPGmRNA and ODFmRNA in the patients of hip fracture due to osteoporosis

Objective：To investigate the gene expression of osteoprotegerin（OPG） and osteoclast differentiation factor（ODF） in the bone tissue of patients with hip fracture due to osteoporosis. Methods：OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers（over 50 years old） with hip fracture（Observer Group） and 30 cases of hip facture sufferers with no osteoporosis（Control group） were analyzed with the Semi-Quantitative RT-PCR method. Results：The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion：Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.

An analysis of the differentiation rules and influencing factors of venture capital in Beijing-Tianjin-Hebei urban agglomeration

Under China's innovation-driven development strategy, venture capital has become an important driving force in urban agglomeration integration and collaborative innovation. This paper uses social network analysis to analyze spatiotemporal differences of venture capital in the Beijing-Tianjin-Hebei urban agglomeration for the period 2005–2015. A gravity model and panel data regression model are used to reveal the influencing factors on spatiotemporal differences in venture capital in the region. This study finds that there is a certain cyclical fluctuation and uneven differentiation in the venture capital network in the Beijing-Tianjin-Hebei urban agglomeration in terms of total investment, and that the three centers of venture capital(Beijing, Shijiazhuang and Tangshan) have a stimulatory effect on surrounding cities; flows of venture capital between cities display certain networking rules, but they are slow to develop and strongly centripetal; there is a strong positive correlation between levels of information infrastructure development and economic development and venture capital investment; and places with relatively underdeveloped financial environments and service industries are less able to apply the fruits of innovation and entrepreneurship and to attract funds. This study can act as a reference for the Beijing-Tianjin-Hebei urban agglomeration in building a world-class super urban agglomeration with the best innovation capabilities in China.