Effect of carrier and axial ligand on the photocatalytic activity of cobalt thioporphyrazine

The photocatalytic activity of cobalt octakis（butylthio） porphyrazine（CoPz（BuS）8） was assessed through photodegradation of the dye rhodamine B（RhB） in water under irradiation with a Xe lamp and aerated conditions.The photocatalytic activity of CoPz（BuS）8 loaded on Al2O3 or SiO2@Fe3O4nanoparticles or coordinated with an axial azide ligand was also investigated.The results demonstrated that the photocatalytic activity of CoPz（BuS）8 loaded on Al2O3 was higher than that loaded on SiO2@Fe3O4.The kinetic curves of RhB degradation in aqueous solutions at different pH indicated the pseudo first-order kinetics of the reaction.The highest degradation rate for CoPz（BuS）8 loaded Al2O3 at pH = 4 after 160 min was 84.6%.However,the advantages of easier separation and recycling as well as the ability to terminate the reaction at any time for the CoPz（BuS）8 loaded SiO2@Fe3O4 cannot be ignored.When electron-rich NaN3 was coordinated with CoPz（BuS）8 as an axial ligand and loaded on Al2O3,the resulting catalyst produced more active oxygen species such as O2^- and HO· to promote the quicker degradation of RhB than that by the other catalysts.For the N3-coordinated CoPz（BuS）8 loaded on Al2O3,the reactions at pH = 4 and 7 distinctly deviated from first-order kinetics,and the degradation rate reached 77.6%after 80 min at pH = 4.

Influence of up-regulation of Notch ligand DLL4 on biological behaviors of human gastric cancer cells

AIM: To investigate the potential roles of Delta-like ligand 4 (DLL4) on the biological behavior of gastric cancer cells and its molecular mechanisms. METHODS: A recombinant eukaryotic expression vector containing human DLL4 gene was constructed and transfected into the human gastric cancer cell line SGC7901. Clones with up-regulated DLL4 were selected and amplified. The effect of DLL4 up-regulation on gastric cancer cell growth was assessed using cell growth assay. The migration and invasion were assessed using a transwell migration assay and matrigel invasion assay. Matrix metalloproteinases were detected using the zymogram technique. Cells were implanted subcutaneously into male BALB/c nu/nu mice. Tumor volumes were then calculated and compared. DLL4 staining in the implanted tumor was performed using immunohistochemistry technique. RESULTS: Growth curves over a six-day time course showed significantly promoted cell proliferation of SGC7901 cells with up-regulated DLL4. DLL4 up-regulation in SGC7901 cells promoted the migration (205.4 ± 15.2 vs 22.3 ± 12.1, P < 0.05) and invasion (68.8 ± 5.3 vs 18.2 ± 6.0, P < 0.05) in vitro and tumorigenicity in vivo (2640.5 ± 923.6 mm 3 vs 1115.1 ± 223.8 mm 3 , P < 0.05). Furthermore, significantly increased mRNA level and increased secretion of matrix metalloproteinase-2 (MMP-2) proenzyme were observed in SGC7901 cells with up-regulated DLL4. However, increased MMP-9 mRNA level but decreased extracellular MMP-9 proenzyme level was observed. CONCLUSION: Our observations indicated a mechanism by which activation of DLL4-mediated Notch signaling promotes the expression and secretion of MMP-2 proenzyme and influences the progress of gastric cancer.

Delta-like ligand 4 in hepatocellular carcinoma intrinsically promotes tumour growth and suppresses hepatitis B virus replication

AIM To investigate the role of Delta-like ligand 4(DLL4) on tumour growth in hepatitis B virus(HBV)-associated hepatocellular carcinoma(HCC) in vivo.METHODS We suppressed DLL4 expression in an HBV expressing HCC cell line, HepG2.2.15 and analysed the growth ability of cells as subcutaneous tumours in nude mice. The expression of tumour angiogenesis regulators, VEGF-A and VEGF-R2 in tumour xenografts were examined by western blotting. The tumour proliferation and neovasculature were examined by immunohistochemistry. The viral replication and viral protein expression were measured by quantitative PCR and western blotting, respectively.RESULTS Eighteen days after implantation, tumour volume in mice implanted with sh DLL4 HepG2.2.15 was significantly smaller than in mice implanted with control HepG2.2.15(P < 0.0001). The levels of angiogenesis regulators, VEGF-A and VEGF-R2 were significantly decreased in implanted tumours with suppressed DLL4 compared with the control group(P < 0.001 and P < 0.05, respectively). Furthermore, the suppression of DLL4 expression in tumour cells reduced cell proliferation and the formation of new blood vessels in tumours. Unexpectedly, increased viral replication was observed after suppression of DLL4 in the tumours.CONCLUSION This study demonstrates that DLL4 is important in regulating the tumour growth of HBV-associated HCC as well as the neovascularization and suppression of HBV replication.

Expression and function of Delta-like ligand 4 in a rat model of retinopathy of prematurity

The Delta-like ligand 4/Notch signaling pathway was shown to participate in the process of retinal development and angiogenesis. However, the function of the Delta-like ligand 4/Notch signaling pathway in retinopathy of prematurity requires further study. Retinopathy of prematurity was induced in 5-day-old Sprague-Dawley rats exposed to hyperoxia for 7 days, and then returned to room air. Reverse transcription-PCR and western blot revealed that Delta-like ligand 4 levels decreased at postnatal day 12 and increased at postnatal day 17 in retinopathy of prematurity rats. Flat-mounted adenosine diphosphatase stained retina and hematoxylin-eosin stained retinal tissue slices showed that the clock hour scores and the nuclei counts in retinopathy of prematurity rats were significantly different compared to normal control rats. After retinopathy of prematurity rats were intravitreally injected with Delta-like ligand 4 monoclonal antibody to inhibit the Delta-like ligand 4/Notch signaling pathway, there was a significant increase in the severity of retinal neovascularization （clock hours） in the intravitreally injected eyes. The nuclei count was highly correlated with the clock hour score. These results suggest that Delta-like ligand 4/Notch signaling plays an essential role in the process of physiological and pathological angiogenesis in the retina.

Association of gene and protein expression and genetic polymorphism of CC chemokine ligand 4 in colorectal cancer

BACKGROUND Leukocytes,such as T cells and macrophages,play an important role in tumorigenesis.CC chemokine ligand(CCL)4,which is produced by lymphocytes and macrophages,has been found to be expressed in the mucosa of the gastrointestinal tract and is a potent chemoattractant for various leukocytes.AIM To examine CCL4 expression and its genetic polymorphism rs10491121 in patients with colorectal cancer(CRC)and evaluate their prognostic significance.METHODS Luminex technology was used to determine CCL4 Levels in CRC tissue(n=98),compared with paired normal tissue,and in plasma from patients with CRC(n=103),compared with healthy controls(n=97).Included patients had undergone surgical resection for primary colorectal adenocarcinomas between 1996 and 2019 at the Department of Surgery,Ryhov County Hospital,Jönköping,Sweden.Reverse transcription quantitative PCR was used to investigate the CCL4 gene expression in CRC tissue(n=101).Paired normal tissue and TaqMan single nucleotide polymorphism assays were used for the CCL4 rs10491121 polymorphism in 610 CRC patients and 409 healthy controls.RESULTS The CCL4 protein and messenger RNA expression levels were higher in CRC tissue than in normal paired tissue(90%,P<0.001 and 45%,P<0.05,respectively).CRC tissue from patients with localized disease had 2.8-fold higher protein expression levels than that from patients with disseminated disease.Low CCL4 protein expression levels in CRC tissue were associated with a 30%lower cancer-specific survival rate in patients(P<0.01).The level of plasma CCL4 was 11%higher in CRC patients than in healthy controls(P<0.05)and was positively correlated(r=0.56,P<0.01)with the CCL4 protein level in CRC tissue.The analysis of CCL4 gene polymorphism rs10491121 showed a difference(P<0.05)between localized disease and disseminated disease in the right colon,with a dominance of allele A in localized disease.Moreover,the rate of the A allele was higher among CRC patients with mucinous cancer than among those with nonmucinous cancer.CONCLUSION The present study indicates that the CRC tissue levels of CCL4 and CCL4 gene polymorphism rs10491121,particularly in the right colon,are associated with clinical outcome in CRC patients.

The ligand coordination approach for improving the stability of low-mercury catalyst in the hydrochlorination of acetylene

Mercuric chloride supported on activated carbon(HgCl_2/AC) is used as an industrial catalyst for the hydrochlorination of acetylene. Loss of HgCl_2 by sublimating from the surface of activated carbon causes the irreversible deactivation of mercury catalyst and environmental pollution. In this work, a ligand coordination approach based on the Principle of Hard and Soft Acids and Bases(HSAB) was employed to design more stable lowmercury catalyst. The low-mercury catalysts(4% HgCl_2 loading) were prepared by using HgCl_2 and potassium halides(KX, X = Cl, I) as precursors. The HgCl_2-4KI/AC catalyst showed best catalytic stability than HgCl_2/AC and HgCl_2-4KCl/AC in the hydrochloriantion of acetylene. HgCl_2 could form more stable complex with KI,K_2HgI_4 as the main active component of the HgCl_2-4KI/AC catalyst. The characterizations of XRD and EDX analysis illustrated that the active component of HgCl_2-4KI/AC was highly dispersed on the surface of activated carbon.The sublimation rates of HgCl_2 from the catalysts verified that the active component with larger stability constant had better thermal stability. Using Hg(Ⅱ) complexes with high stability constant as the active component may be the research direction of developing highly stable low-mercury catalyst for the hydrochlorination of acetylene.

Levels of soluble delta-like ligand 1 in the serum and cerebrospinal fluid of tuberculous meningitis patients

In this study, the levels of soluble delta-like ligand 1 in cerebmspinal fluid and serum of 50 patients with tuberculous meningitis, 30 patients with viral meningitis, 20 patients with purulent meningitis and 40 subjects without central nervous system disease were determined using an enzyme-linked immunosorbent assay. The mean levels of soluble delta-like ligand 1 in both cerebrospinal fluid and serum from patients with tuberculous meningitis were significantly higher compared with those from patients with viral meningitis or purulent meningitis or from subjects without central nervous system disease. Meanwhile, the level of soluble delta-like ligand 1 gradually decreased as tuberculous meningitis patients recovered. If patients deteriorated after treatment, the level of soluble delta-like ligand 1 in cerebrospinal fluid gradually increased. There was no correlation between the level of soluble delta-like ligand 1 and the protein level/cell number in cerebrospinal fluid. Our findings indicate that the levels of soluble delta-like ligand 1 in cerebrospinal fluid and serum are reliable markers for the diagnosis of tuberculous meningitis and for monitoring treatment progress. At the same time, this index is not influenced by protein levels or cell numbers in cerebrospinal fluid.

Delta-like ligand 4在脑星形细胞瘤中的表达及临床意义

目的探讨Delta-like ligand4(DLL4)在脑星形细胞瘤中的表达及与微血管密度(MVD)的关系。方法脑星形细胞瘤标本40例,分Ⅰ级,Ⅱ级,Ⅲ～Ⅳ级三组,分别使用DLL4单克隆抗体、抗人CD31多克隆抗体行免疫组织化学染色,Image-Pro Plus6.0软件分析DLL4光密度(optical density,OD)半定量分析DLL4表达,统计微血管数。结果各组DLL4蛋白OD值为Ⅰ级514.71±179.56,Ⅱ级961.97±88.53,Ⅲ～Ⅳ级1125.31±225.35,P<0.01;MVD值Ⅰ级24.75±10.33,Ⅱ级57.62±12.45,Ⅲ～Ⅳ级114.60±25.28,P<0.01。DLL4的OD值与MVD的相关系数为γ=0.68(P<0.01)。结论 DLL4表达随星型细胞瘤恶性程度的升高逐步增加,与微血管密度密切相关,对判断星型细胞瘤的恶性程度及血供有指导意义。

Synthesis, Characterization and Antibacterial Activity of Mixed Ligand (HL) Complexes Mn(ll), Co(ll), Ni(ll), Zn(ll), Cd(ll) and Hg(ll) with Azide (N₃<sup style="margin-left:-6px;">-</sup>)

The complexes of mixed ligand (HL) as primary ligand with azide ion (N3-) as co-ligand with Mn(ll), Co(ll), Ni(ll), Zn(ll), Cd(ll) and Hg(ll) were prepared via reaction metal (ll) chloride salt with ligand (HL) and sodium azide (NaN3) using 1:2:2 mole ratio in ethanol solvent, respectively. The complexes of mixed ligand (HL) were characterized by elemental microanalysis (C.H.N), atomic absorption chloride content, molar conductance, magnetic susceptibility, melting point, FTIR and UV-Vis spectral data. The anti bacterial activity with four kinds of bacteria, Staphylococcus aureus, Bacillus, Escherichia coli and Pseudomonas aureus was studied.

Syntheses, Characterization and Biological Activity of Coordination Compounds of 3-Hydroxy-2-methyl-4<i>H</i>-pyran-4-one and Its Mixed Ligand Complexes with 1,2-Diaminocyclohexane

Coordination compounds of 3-hydroxy-2-methyl-4H-pyran-4-one with iron(III), cobat(III) and chromium(III) were synthesized with M:L (1:2). Mixed ligand coordination compounds of 3-hydroxy-2-methyl-4H-pyran-4-one and 1,2-diaminocyclohexane using the same metal ions were also synthesized M:L1:L2 (1:1:1) where L1 is 3-hydroxy-2-methyl-4H-pyran-4-one and L2 is 1,2-diaminocyclohexane. The coordination compounds obtained were characterized using electronic and infrared spectral analyses, magnetic susceptibility and percentage metal analysis. They were also evaluated for their cytotoxic and antioxidant activities. The result obtained suggested that octahedral geometry was obtained for all the compounds, as a result of additional two molecules of the solvent coordinated to the metal ions. Both the primary and secondary ligands coordinated in a bidentate fashion. The synthesized compounds exhibited moderate cytotoxicity, although none was as active as the standard. The cobalt(III) mixed ligand complex elicited the highest activity. The synthesized compounds all exhibited good to moderate antioxidant activity.

Organophosphine ligand derived sandwich-structural electrocatalyst for oxygen evolution reaction

The synchronous construction of metal phosphate and phosphorus-doped carbon structures is of great significance to innovate the design,synthesis,and application of catalysts,as these phosphoruscontaining composite materials have shown a remarkable contribution to electrocatalysts.However,their preparation procedure generally involves using large amounts of excess phosphorus sources for phosphorization,which inevitably release poisonous PH_(3) or dangerous phosphorus vapor.Here,a strategy for in-situ formation of FePO_(4) embedded in P-doped carbon 2D nano film(FePO_(4)/PdC)is developed using a highly integrated precursor,which is a small molecular organophosphine ligand,1,1’bis(diphenylphosphine)ferrocene(DPPF).The multi-source precursor DPPF that contains Fe,P,and C is molecular-vapor-deposited on the nickel foam(NF)supported ZIF-67 nanosheets to obtain the composite catalyst,namely DPPF-500/ZIF-67/NF.FePO_(4)/PdC encapsulated the ZIF-67 derived Co/N-doped carbon matrix(Co NC)to form a sandwich structure FePO_(4)/PdC@CoNC.The constructed catalyst shows good performance for OER,requiring an overpotential of only 297 m V to deliver 600 m A/cm^(2) with a Tafel slope of 42.7 m V dec^(-1).DFT calculations demonstrate that the synergistic effects between the metal active center and P-doped carbon film reduce the energy barriers and improve electron transport.This method of constructing P-containing catalysts overcomes the demand for additional P sources to realize eco-friendly fabrication and yields a unique structure with good catalytic activity.

Gold （III） Complexes with Thiolactate and bis-（1,4-Sodiumthiolactate） Butane Ligands

The new ligand bis-（1,4-sodium thiolactate） butane （L）-O2CCH3S-（CH2）4SCHCH3CO2- has been prepared from the reaction of disodium salt of thiolactic acid and 1,4-dichlorobutane, while the disodium thiolactate was prepared instanteously through the reaction of thiolactic acid with NaOH. Mono and dinuclear complexes were obtained by direct reaction of the above ligands with H[AuCI4] in 1 ： 1, 2：1, 1：2, 2：2 and 3：1 ligands to metal molar ratio. The prepared complexes were characterized by elemental analysis, spectral studies FTIR （Fourier transform Infrared） and UV-Vis, magnetic measurement, conductivity measurement and IHNMR for the ligand （L） and some of the complexes. The conductance data indicate that the complexes of the formulas Na[Au（SCH3CHCOO）2], Na[Au（SCH3CHCOO）（OOCCHCH3SH）2] and [Au（L）]Cl are 1：1 electrolyte. Electronic spectra and magnetic moment values indicate the presence of square planner geometry around Au（III） ions.

In situ meso-tetra(4-carboxyphenyl)porphyrin ligand substitution in Hf-MOF for enhanced catalytic activity and stability in photoredox reactions

Though there are numerous intrinsic merits of metal-organic frameworks(MOFs),low charge separation efficiency has imposed heavy restrictions on their photocatalytic application.Herein,in situ porphyrin ligand substitution,as a strategy for improving the charge separation efficiency and increasing the amounts of active sites,has been designed and realized in a Hf-biphenyl dicarboxylic acid(BPDC)MOF.Specifically,a size and geometry matched meso-tetra(4-carboxyphenyl)porphyrin(TCPP)ligand was selected and doped into Hf-BPDC MOF by forming coordinating bonds with Hf centers,forming dualligand Hf-BPDC-TCPP MOF.The resultant Hf-BPDC-TCPP MOF showed significantly improved activity and chemical stability in the photocatalytic H_(2)generation(261μmol·g^(-1)·h^(-1))and tetracycline(TC)degradation reactions(95.8%),which was 48 and 1.47 folds higher than that of the Hf-BPDC MOF.Photophysical and electrochemical studies revealed that the introduction of porphyrin ligand could generate a stronger internal electric field for boosting the charge separation and transfer,increase the specific surface area for providing more active sites,and narrow the band gap to enhance the visible light absorption.This in situ ligand substitution method provides a promising approach to build a tunable platform for constructing high-performance MOF photocatalysts.

Different-shaped ligand mediating efficient structurally similar cage-to-cage transformation

The transformation of a Palladium-based metal-organic cage to a structurally similar one by direct ligand replacement usually leads to unwanted ligand scrambling. In this work, an intermediate ligand with different shape and basicity from the initial/final ones was introduced to avoid ligand scrambling to achieve the efficient indirect cage-to-similar-cage transformation. Compared with the direct transformation, the stepwise conversion has the advantages of high efficiency(93%) and simple workup.

西藏地区结直肠癌免疫治疗和靶向治疗相关分子标志物的检测及意义

目的研究西藏地区结直肠癌中SWI/SNF相关、基质相关、肌动蛋白依赖性染色质调节因子A亚科成员4(SMARCA4)/Brahma相关基因1、V-raf鼠类肉瘤病毒癌基因同源物B(BRAF)、P53、程序性死亡受体1(PD-1)及程序性死亡配体1(PD-L1)免疫组织化学表达和BRAF、神经营养因子酪氨酸受体激酶(NTRK)基因改变情况,为西藏地区结直肠癌患者的靶向治疗及免疫治疗提供依据。方法收集2015年1月至2021年7月西藏自治区人民医院经手术切除病理确诊为结直肠癌病例64例,全部病例均进行SMARCA4、BRAF、P53、PD-1、PD-L1免疫组织化学染色和NTRK1、NTRK2、NTRK3融合基因荧光原位杂交检测及BRAF V600E基因突变PCR检测。结果64例结直肠癌病例男女比例1.21∶1,平均年龄(56.59±13.27)岁;46例(71.88%)位于结肠,18例(28.12%)位于直肠;60例(93.75%)为腺癌,4例(6.25%)为其他类型;11例(17.19%)为T1或T2期,53例(82.81%)为T3或T4期;24例(37.50%)出现淋巴结转移。免疫组织化学方面,64例中1例(1.56%)SMARCA4部分肿瘤细胞表达减弱或缺失,4例(6.25%)BRAF肿瘤细胞阳性表达,35例(54.69%)P53为突变型表达;45例(70.31%)PD-1肿瘤相关免疫细胞阳性比例分数<10%,19例(29.69%)≥10%;52例(81.25%)PD-L1联合阳性分数<10,12例(18.75%)≥10。64例NTRK1、NTRK2、NTRK3融合基因检测均为阴性;4例(6.25%)检测到BRAF V600E基因突变;1例SMARCA4表达缺失病例未检测到SMARCA4基因改变。PD-L1的表达与错配修复缺陷/高度微卫星不稳定和PD-1的高表达呈显著正相关(χ^(2)=10.223,P=0.001;χ^(2)=11.979,P=0.001)。结论西藏地区结直肠癌中较少出现SMARCA4表达减弱或缺失及NTRK融合基因改变,少数病例有BRAF V600E基因突变,Pan-TRK和BRAF免疫组织化学可作为NTRK融合基因及BRAF基因突变的初筛方法。错配修复缺陷/高度微卫星不稳定的病例中更容易出现PD-L1蛋白高表达,这部分患者有望获益于免疫治疗。P53突变与PD-L1表达无相关性,PD-1的高表达和PD-L1的高表达呈正相关。

利用受体配体亲和技术筛选黄芩中血管紧张素转换酶2和二肽基肽酶4抑制剂

目的筛选中药黄芩中血管紧张素转换酶2(ACE2)和二肽基肽酶4(DPP-4)抑制剂。方法以ACE2和DPP-4作为靶蛋白,利用受体配体亲和超滤和液质联用技术,对黄芩中与ACE2和DPP-4亲和的化合物进行筛选和分析,以筛选具有同时抑制ACE2和DPP-4的化合物。结果从黄芩中筛选出了5,7,2′,6′-4羟基黄酮、5,7,2′,5′-4羟基-8,6′-二甲氧基黄酮、白杨素-7-O-葡萄糖醛酸苷、黄芩素-6-O-葡萄糖醛酸苷、千层纸素A-7-O-葡萄糖醛酸苷、汉黄芩苷、白杨素、千层纸素A,可以同时亲和抑制ACE2和DPP-4,具有潜在的抗新型冠状病毒的作用。结论从黄芩中筛选出与新型冠状病毒肺炎有关的靶蛋白抑制剂,具备潜在开发价值。

宣肺合剂联合西药治疗慢性支气管炎急性发作的疗效

目的 观察宣肺合剂联合西药治疗慢性支气管炎急性发作的疗效,及其对血清CXC趋化因子受体4(CXCR4)、半乳糖凝集素-9(Gal-9)和趋化因子3(CCL3)水平的影响。方法 选择2020年1月-2021年12月在本院诊治的慢性支气管炎急性发作的患者96例,分为观察组和对照组各48例。对照组予以常规西药治疗,观察组在对照组的基础上予以宣肺合剂治疗。比较两组治疗后的疗效和不良反应,比较治疗前后喘息、咳痰、咳嗽积分、第一秒用力呼气量(FEV1)、用力肺活量(FVC)、最大通气量(MVV)、CXCR4、Gal-9和CCL3水平的变化。结果 观察组的总有效率为95.83%,对照组的总有效率为79.17%,观察组显著优于对照组(P<0.05);两组的不良反应率差异无统计学意义(P>0.05)。两组治疗前喘息、咳痰、咳嗽积分、FEV1、FVC、MVV、CXCR4、Gal-9和CCL3水平差异无统计学意义(P>0.05);治疗后两组的喘息、咳痰、咳嗽积分、CXCR4、Gal-9和CCL3水平均较治疗前显著降低,与对照组比较观察组出现明显降低(均P<0.01);治疗后两组的FEV1、FVC和MVV水平均较治疗前显著升高,与对照组比较观察组显著升高(均P<0.01)。结论 宣肺合剂能够提高西药对慢性支气管炎急性发作的疗效,缓解症状和改善肺功能,其机制可能与降低机体CXCR4、Gal-9和CCL3的水平有关。

高表达Delta4增加Notch基因的表达

Notch信号传导系统在介导造血细胞增殖与分化过程中具有重要作用。通过分子克隆技术成功构建含标记基因FLAG的Notch配基Delta4的高表达载体pTracer CMV Delta4 FLAG ,瞬时转染COS7细胞 ,4 8h后收获细胞并制备融合蛋白 ,SDS PAGE凝胶电泳和Western blot证实后 ,将其稳定转染CHO细胞 ,Western blot鉴定并筛选高表达Delta4的Delta4 CHO1 4及Delta4 CHO1 5细胞株 ,利用Luciferase分析方法进行Delta4功能性研究。研究结果发现Delta4对Notch1及Notch2均具有信号功能活性 ,且对后者的活性功能水平大于前者 ,说明Delta4为Notch1及Notch2的配基。与其他配基功能比较 :对Notch1,Delta4的功能活性高于Delta1及Jagged1,但略低于Jagged2 ;对Notch2 ,Delta4的功能活性低于Delta1、Jagged1及Jagged2 ,但亦具有较强的活性水平。

Delta4的功能性研究及与其他Notch配体的比较

目的:探讨Delta4基因在Notch传导机制中的作用。方法:构建pTracer.CMV.Delta4.FLAG载体,瞬时转染COS7细胞、稳定转染CHO细胞,筛选高表达Delta4的稳定CHO细胞系。用Luciferase分析,观察并比较Delta4对Notch1-CHO及Notch2-CHO两个宿主细胞的信号功能活性,与Delta1、Jagged1及Jagged2比较,从而对此基因定性并获知其信号功能活性水平。结果:Western-blot证实pTracer.CMV.Delta4.FLAG可瞬时转染COS7细胞及稳定转染CHO细胞,并根据Delta4蛋白表达条带的强弱筛选高表达Delta4-CHO细胞系。Delta4对Notch1及Notch2均具有信号功能活性,且对后者的活性功能水平大于前者。对Notch1,Delta4的功能活性略低于Jagged2,但高于Delta1及Jagged1;对Notch2,Delta4的功能活性低于Delta1、Jagged1及Jagged2,但亦具有较强的活性水平。结论:建立的Delta4-CHO细胞系功能稳定,Delta4为Notch1及Notch2的配体,且对Notch2的活性水平高于Notch1。

基于Notch4和Delta4研究当归补血汤协同肌源性干细胞移植促造血重建的作用

目的:基于Notch4和Delta4探讨当归补血汤(Danggui Buxue Decoction,DBD)协同肌源性干细胞(Musclederived stem cells,MDSCs)向造血方向调控的作用机制。方法:将雌性昆明小鼠随机分成6组,分别为照射模型组、骨髓移植组、MDSCs移植组、等效剂量DBD预处理+MDSCs组(给药1组)、3倍DBD预处理+MDSCs组(给药2组)和5倍DBD预处理+MDSCs移植组(给药3组)。照射前各组分别给予生理盐水和不同剂量DBD灌胃1周,经8Gy^(137)Cs-γ射线照射后,尾静脉分别移植骨髓细胞和MDSCs。用real-time PCR检测3周末时小鼠骨髓中CD34、Notch4和Delta4 mRNA表达量。结果:与照射模型组比,干预组中CD34 mRNA上调(P<0.05),且以给药3组上调幅度最大;Notch4 mRNA下调(P<0.05),且给药1组下调幅度最大;除骨髓移植组外,其余各组Delta4 mRNA均上调(P<0.05),且给药3组上调幅度最大。结论:当归补血汤协同肌源性干细胞移植能促进受照射小鼠造血重建,且5倍当归补血汤协同MDSCs移植效果最佳。Notch4和Delta4在骨髓造血干细胞移植和MDSCs移植中的作用不同,其促进骨髓造血干细胞、MDSCs向造血细胞分化的具体调控机制尚待深入探索。