Effects of serum containing natural cerebrolysin on glucose-regulated protein 78 and CCAAT enhancer-binding protein homologous protein expression in neuronal PC12 cells following tunicamycin-induced endoplasmic reticulum stress

BACKGROUND： Glucose-regulated protein 78 （GRP78）, a marker of endoplasmic reticulum stress, can prolong cell survival. Alternatively, CCAAT enhancer-binding protein homologous protein （CHOP）, a transcription factor specific for endoplasmic reticulum stress, can cause cell cycle arrest and cell apoptosis. OBJECTIVE： To study the protective effects of serum containing natural cerebrolysin on endoplasmic reticulum stress in tunicamycin-induced neuronal PC12 cells, and analyze the influence on GRP78 and CHOP expressions. DESIGN, TIME AND SETTING： A parallel controlled study was performed at the Institute of Integrated Western and Traditional Chinese Medicine, Shenzhen Hospital, Southern Medical University, between March 2006 and August 2008. MATERIALS： Adult Sprague-Dawley rats were perfused with natural Cerebrolysin aqueous extract （0.185 g/kg/d） to produce serum containing natural Cerebrolysin. Physiological saline was used to produce blank serum. PC12 cell line was provided by Shanghai Institute of Cell Biology, Chinese Academy of Science. Tunicamycin was provided by Sigma （St. Louis, USA）, and natural Cerebrolysin, containing ginseng, rhizoma gastrodiae, and gingko leaf （1：2：2）, by Shengzhen Institute of Integrated Western and Traditional Chinese Medicine. METHODS： PC12 cells were treated with DMEM culture media containing 10% blank serum （normal control group）, tunicamycin （1 μg/mL; model group）, and 5%, 10%, and 15% serum containing natural cerebrolysin and tunicamycin （1 μ g/mL; low-, moderate-, and high-dose serum containing natural cerebrotysin groups）, for 2 hours. MAIN OUTCOME MEASURES： PC12 cells were treated with tunicamycin for 48 hours after which apoptosis was measured using the TUNEL method to calculate apoptotic index. GRP78 expression was detected using immunocytochemistry. After 24 hours of treatment with tunicamycin, GRP78 and CHOP mRNA expressions were measured using RT-PCR. RESULTS： The apoptotic index and CHOP mRNA expression were in the model group and three cerebrolysin groups were significantly increased when compared to the normal control group （P 〈 0.05）. In contrast, GRP78 mRNA and protein expressions were significantly decreased （P 〈 0.05）. CONCLUSION： Serum containing natural cerebrolysin significantly reduced apoptosis in neuronal PC12 cells following tunicamycin-induced endoplasmic reticulum stress. These results may be related to an up-regulation of GRP78 expression and down-regulation of CHOP expression, both of which displayed dose-dependent effects.

Overexpression of GATA binding protein 4 and myocyte enhancer factor 2C induces differentiation of mesenchymal stem cells into cardiac-like cells

BACKGROUND Heart diseases are the primary cause of death all over the world.Following myocardial infarction,billions of cells die,resulting in a huge loss of cardiac function.Stem cell-based therapies have appeared as a new area to support heart regeneration.The transcription factors GATA binding protein 4(GATA-4)and myocyte enhancer factor 2C(MEF2C)are considered prominent factors in the development of the cardiovascular system.AIM To explore the potential of GATA-4 and MEF2C for the cardiac differentiation of human umbilical cord mesenchymal stem cells(hUC-MSCs).METHODS hUC-MSCs were characterized morphologically and immunologically by the presence of specific markers of MSCs via immunocytochemistry and flow cytometry,and by their potential to differentiate into osteocytes and adipocytes.hUC-MSCs were transfected with GATA-4,MEF2C,and their combination to direct the differentiation.Cardiac differentiation was confirmed by semiquant itative real-time polymerase chain reaction and immunocytochemistry.RESULTS hUC-MSCs expressed specific cell surface markers CD105,CD90,CD44,and vimentin but lack the expression of CD45.The transcription factors GATA-4 and MEF2C,and their combination induced differentiation in hUC-MSCs with significant expression of cardiac genes i.e.,GATA-4,MEF2C,NK2 homeobox 5(NKX2.5),MHC,and connexin-43,and cardiac proteins GATA-4,NKX2.5,cardiac troponin T,and connexin-43.CONCLUSION Transfection with GATA-4,MEF2C,and their combination effectively induces cardiac differentiation in hUC-MSCs.These genetically modified MSCs could be a promising treatment option for heart diseases in the future.

Hepatitis B virus X protein regulates the mEZH2 promoter via the E2F1-binding site in AML12 cells

Histone lysine methyltransferase EZH2 has been reported to be frequently overexpressed in hepatocellular carcinoma(HCC) tissues and associated with hepatocarcinogenesis.However,the exact mechanism of EZH2 up-regulation in HCC has not been determined.In this study,we used murine hepatocyte AML12 cells to investigate the role of hepatitis B virus X protein(HBx) in regulating the expression of mEZH2.Western blot analysis demonstrated that the expression level of mEZH2 protein in AML12 cells was up-regulated by HBx in a dose-dependent manner.To further investigate the mechanism of mEZH2 overexpression,the 2500 bp regulatory sequence upstream from the first exon of the mEZH2 gene was amplified from AML12 genomic DNA and constructed into a luciferase reporter plasmid.The luciferase activity of the mEZH2 promoter significantly increased in AML12 cells co-transfected with HBx plasmid,and deleting the-486/-214 promoter region decreased HBx-induced mEZH2 promoter activation by nearly 50%.The-486/-214 region was then analyzed in the TRANSFAC 6.0 database and a typical E2F1-binding site was found.Mutation of this E2F1-binding site or knockdown of E2F1 expression by RNAi led to a dramatic decrease in HBx-induced activation of the mEZH2 promoter and mEZH2 overexpression in AML12 cells.These results provide evidence that HBx up-regulates mEZH2 expression by transactivating the mEZH2 promoter through E2F1 transcription factor,thereby providing new epigenetic evidence for the carcinogenic effect of HBx.

Targeting Enhancer of Zeste Homolog 2 as a promising strategy for cancer treatment

Polycomb group proteins represent a global silencing system involved in development regulation.In specific,they regulate the transition from proliferation to differentiation,contributing to stem-cell maintenance and inhibiting an inappropriate activation of differentiation programs.Enhancer of Zeste Homolog 2(EZH2) is the catalytic subunit of Polycomb repressive complex 2,which induces transcriptional inhibition through the tri-methylation of histone H3,an epigenetic change associated with gene silencing.EZH2 expression is high in precursor cells while its level decreases in differentiated cells.EZH2 is upregulated in various cancers with high levels associated with metastatic cancer and poor prognosis.Indeed,aberrant expression of EZH2 causes the inhibition of several tumor suppressors and differentiation genes,resulting in an uncontrolled proliferation and tumor formation.This editorial explores the role of Polycomb repressive complex 2 in cancer,focusing in particular on EZH2.The canonical function of EZH2 in gene silencing,the non-canonical activities as the methylation of other proteins and the role in gene transcriptional activation,were summarized.Moreover,mutations of EZH2,responsible for an increased methyltransferase activity in cancer,were recapitulated.Finally,various drugs able to inhibit EZH2 with different mechanism were described,specifically underscoring the effects in several cancers,in order to clarify the role of EZH2 and understand if EZH2 blockade could be a new strategy for developing specific therapies or a way to increase sensitivity of cancer cells to standard therapies.

L-4F Inhibits Oxidized Low-density Lipoprotein-induced Inflammatory Adipokine Secretion via Cyclic AMP/Protein Kinase A-CCAAT/Enhancer Binding Protein β Signaling Pathway in 3T3-L1 Adipocytes

Background： Adipocytes behave like a rich source of pro-inflammatory cytokines including monocyte chemoattractant protein- 1 （MCP- 1）. Oxidized low-density lipoprotein （oxLDL） participates in the local chronic inflammatory response, and high-density lipoprotein could counterbalance the proinftammatory function of αLDL, but the underlying mechanism is not completely understood. This study aimed to evaluate the effect of apolipoprotein A-I mimetic peptide L-4F on the secretion and expression of MCP-1 in fully differentiated 3T3-L 1 adipocytes induced by oxLDL and to elucidate the possible mechanisms. Methods： Fully differentiated 3T3-L 1 adipocytes were incubated in the medium containing various concentration of L-4F （0-50 gg/ml） with oxLDL （50 Lag/ml） stimulated, with/without protein kinase A （PKA） inhibitor H-89 （10 gmol/L） preincubated. The concentrations of MCP- 1 in the supematant, the mRNA expression of MCP- 1, the levels of CCAAT/enhancer binding protein α （C/EBPα）, and CCAAT/ enhancer binding protein 13 （C/EBPβ） were evaluated. The monocyte chemotaxis assay was performed by micropore filter method using a modified Boyden chamber. Results： OxLDL stimulation induced a significant increase ofMCP-1 expression and secretion in 3T3-L 1 adipocytes, which were inhibited by L-4F preincubation in a dose-dependent manner. PKA inhibitor H-89 markedly reduced the oxLDL-induced MCP-1 expression, but no further decrease was observed when H-89 was used in combination with L-4F （50 μg/ml） （P 〉 0.05）. OxLDL stimulation showed no significant effect on C/EBPa protein level but increased C/EBPβ protein level in a time-dependent manner. H-89 and L-4F both attenuated C/EBPI3 protein level in oxLDL-induced 3T3-L1 adipocytes. Conclusions： OxLDL induces C/EBPI3 protein synthesis in a time-dependent manner and enhances MCP-1 secretion and expression in 3T3-L 1 adipocytes. L-4F dose-dependently counterbalances the pro-inflammatory effect of oxLDL, and cyclic AMP/PKA-C/EBP-β signaling pathway may participate in it.

IMMUNOHISTOCHEMICAL DEMONSTRATION OF CCAAT/ENHANCER BINDING PROTEIN (C/EBP) IN HUMAN LIVER TISSUES OF VARIOUS ORIGIN

C / EBP is a sequence-specific DNA-binding protein. In order to indentify its distribution and localization, immunohistochemical technique (ABC method) was done using anti-C / EBP polypeptide antibodies 1103#, 425# in liver specimens from 20 normal adults, 5 neonates, 6 patients with hepatitis, 25 with liver cirrhosis, 80 with hepatocellular carcinoma (40 cases were associated with surrounding nontumorous tissues) and 26 patients with cholangiocarcinoma (15 cases were associated with surrounding nontumorous tissues). The results showed that C / EBP was diffusely distributed in nuclei and cytoplasm of differentiated liver cells and very low or undetectable in liver cancer cells. The manifestation of C / EBP correlated with degree of differentiation of tumour cells, and was obviously weaker than that in surrounding nontumorous tussues. C / EBP positive staining has also been found in regenerating epithelial cells of bile ductules. The results suggested that C / EBP should play an important role in establishing and maintaining the differentiation of liver cells.

Expression of COX-2 and transcription factor CCAAT enhancer binding proteinβin refractory sinusitis with nasal polyps and its significance

Objective To study the expression and significance of COX-2 and C/EBP-βin refractory sinusitis with nasal polyps,and to explore the relationship between them and the recurrence of sinusitis with nasal polyps.Methods The protein expression of COX-2 and C/EBP-βin 20 cases of refractory sinusitis with nasal polyps,20 cases of sinusitis with nasal polyps and 20 cases of normal nasal mucosa were detected by western blot,and the relationship between the two was compared.Results The expression levels of COX-2 and C/EBP-βin refractory sinusitis with nasal polyps were significantly different from those in refractory sinusitis with nasal polyps(P<0.05);The expression levels of COX-2 and C/EBP-βin sinusitis tissues with nasal polyps were significantly different from those in normal nasal mucosa tissues(P<0.05);The expression levels of COX-2 and C/EBP-βin each group were significantly correlated(P<0.05).Conclusions The high expression of COX-2 and C/EBP-βmay be closely related to postoperative recurrence of sinusitis patients with nasal polyps.Both may be used as objective indicators to judge the postoperative follow-up and recurrence tendency of patients with sinusitis with nasal polyps..

Yinchenhao decoction attenuates obstructive jaundice-induced liver injury and hepatocyte apoptosis by suppressing protein kinase RNA-like endoplasmic reticulum kinase-induced pathway

BACKGROUND Chronic biliary obstruction results in ischemia and hypoxia of hepatocytes,and leads to apoptosis.Apoptosis is very important in regulating the homeostasis of the hepatobiliary system.Endoplasmic reticulum(ER)stress is one of the signaling pathways that induce apoptosis.Moreover,the protein kinase RNA-like endoplasmic reticulum kinase(PERK)-induced apoptotic pathway is the main way;but its role in liver injury remains unclear.Yinchenhao decoction(YCHD)is a traditional Chinese medicine formula that alleviates liver injury and apoptosis,yet its mechanism is unknown.We undertook this study to investigate the effects of YCHD on the expression of ER stress proteins and hepatocyte apoptosis in rats with obstructive jaundice(OJ).AIM To investigate whether YCHD can attenuate OJ-induced liver injury and hepatocyte apoptosis by inhibiting the PERK-CCAAT/enhancer-binding protein homologous protein(CHOP)-growth arrest and DNA damage-inducible protein 34(GADD34)pathway and B cell lymphoma/leukemia-2 related X protein(Bax)/B cell lymphoma/leukemia-2(Bcl-2)ratio.METHODS For in vivo experiments,30 rats were divided into three groups:control group,OJ model group,and YCHD-treated group.Blood was collected to detect the indicators of liver function,and liver tissues were used for histological analysis.For in vitro experiments,30 rats were divided into three groups:G1,G2,and G3.The rats in group G1 had their bile duct exposed without ligation,the rats in group G2 underwent total bile duct ligation,and the rats in group G3 were given a gavage of YCHD.According to the serum pharmacology,serum was extracted and centrifuged from the rat blood to cultivate the BRL-3A cells.Terminal deoxynucleotidyl transferase mediated dUTP nick end-labelling(TUNEL)assay was used to detect BRL-3A hepatocyte apoptosis.Alanine aminotransferase(ALT)and aspartate transaminase(AST)levels in the medium were detected.Western blot and quantitative real-time polymerase chain reaction(qRT-PCR)analyses were used to detect protein and gene expression levels of PERK,CHOP,GADD34,Bax,and Bcl-2 in the liver tissues and BRL-3A cells.RESULTS Biochemical assays and haematoxylin and eosin staining suggested severe liver function injury and liver tissue structure damage in the OJ model group.The TUNEL assay showed that massive BRL-3A rat hepatocyte apoptosis was induced by OJ.Elevated ALT and AST levels in the medium also demonstrated that hepatocytes could be destroyed by OJ.Western blot or qRT-PCR analyses showed that the protein and mRNA expression levels of PERK,CHOP,and GADD34 were significantly increased both in the rat liver tissue and BRL-3A rat hepatocytes by OJ.The Bax and Bcl-2 levels were increased,and the Bax/Bcl-2 ratio was also increased.When YCHD was used,the PERK,CHOP,GADD34,and Bax levels quickly decreased,while the Bcl-2 levels increased,and the Bax/Bcl-2 ratio decreased.CONCLUSION OJ-induced liver injury and hepatocyte apoptosis are associated with the activation of the PERK-CHOP-GADD34 pathway and increased Bax/Bcl-2 ratio.YCHD can attenuate these changes.

腺苷预处理对脑缺血再灌注损伤大鼠脑组织中CCAAT/增强子结合蛋白同源蛋白表达的影响

目的 观察腺苷预处理(AP)对脑缺血再灌注损伤大鼠脑组织中CCAAT/增强子结合蛋白同源蛋白(CHOP)表达的影响,探讨AP对脑缺血再灌注损伤大鼠的神经保护作用机制。方法 将36只健康雄性Sprague Dawley大鼠按随机数字表法分为假手术组、缺血再灌注(IR)组和AP组,每组12只。AP组大鼠术前3 d腹腔注射1.5 mg·kg^(-1)腺苷注射液,每日1次;假手术组和IR组大鼠术前3 d腹腔注射等量生理盐水,每日1次。IR组及AP组大鼠采用线栓法制备大脑中动脉栓塞(MCAO)模型,并于栓塞2 h后拔出栓线恢复血供制备IR模型;假手术组大鼠不插入栓线,余处理同IR组及AP组。于再灌注24 h时,根据5分制神经行为学评分标准对3组大鼠进行神经功能缺损评分;然后,断头处死3组大鼠,取脑组织;应用苏木精-伊红染色法观察3组大鼠脑组织病理学改变,实时荧光定量聚合酶链式反应法检测3组大鼠脑组织中CHOP mRNA相对表达量,免疫组织化学法检测3组大鼠脑组织中CHOP蛋白阳性表达情况,脱氧核糖核苷酸末端转移酶介导的缺口末端标记法检测3组大鼠脑组织细胞凋亡情况。结果 3组大鼠神经功能缺损评分比较差异有统计学意义(F=157.923,P<0.05);IR组和AP组大鼠神经功能缺损评分显著高于假手术组(t=17.663、7.133,P<0.05),AP组大鼠神经功能缺损评分显著低于IR组(t=-10.530,P<0.05)。假手术组大鼠脑组织神经元形态结构正常,细胞核完整,间质无水肿;IR组大鼠脑组织神经元数目减少、细胞核溶解、出现空泡,间质水肿,组织疏松;AP组大鼠神经元损伤程度显著低于IR组。3组大鼠脑组织中CHOP mRNA相对表达量比较差异有统计学意义(F=2 989.751,P<0.05);IR组和AP组大鼠脑组织中CHOP mRNA相对表达量显著高于假手术组(t=75.514、23.502,P<0.05),AP组大鼠脑组织中CHOP mRNA相对表达量显著低于IR组(t=-52.171,P<0.05)。3组大鼠脑组织中CHOP蛋白阳性细胞表达率比较差异有统计学意义(F=2 257.096,P<0.05);IR组和AP组大鼠脑组织中CHOP蛋白阳性细胞表达率显著高于假手术组(t=65.927、21.744,P<0.05),AP组大鼠脑组织中CHOP蛋白阳性细胞表达率显著低于IR组(t=-44.183,P<0.05)。3组大鼠脑组织细胞凋亡率比较差异有统计学意义(F=1 519.372,P<0.05);IR组和AP组大鼠脑组织细胞凋亡率显著高于假手术组(t=5.512、2.693,P<0.05),AP组大鼠脑组织细胞凋亡率显著低于IR组(t=-2.818,P<0.05)。结论 AP可通过抑制CHOP的表达减轻脑缺血再灌注损伤。

Computational Determination of the Binding Mode of α-Conotoxin to Nicotinic Acetylcholine Receptor

Abstract Conotoxins belong to the large families of disulfide-rich peptide toxins from cone snail venom, and can act on a broad spectrum of ion channels and receptors. They are classified into different subtypes based on their targets. The a-conotoxins selectively inhibit the current of the nicotinic acetylcholine receptors. Because of their unique selectivity towards distinct nAChR subtypes, a-conotoxins become valuable tools in nAChR study. In addition to the X-ray structures of a-conotoxins in complex with acetyleholine-binding protein, a homolog of the nAChR ligand-binding domain, the high-resolution crystal structures of the extracellular domain of the al and a9 subunits are also obtained. Such structures not only revealed the details of the configuration of nAChR, but also provided higher sequence identity templates for modeling the binding modes of a-conotoxins to nAChR. This mini-review summarizes recent modeling studies for the determination of the binding modes of a-conotoxins to nAChR. As there are not crystal structures of the nAChR in complex with conotoxins, computational modeling in combination of mutagenesis data is expected to reveal the molecular recognition mechanisms that govern the interactions between a-conotoxins and nAChR at molecular level. An accurate determination of the binding modes of a-conotoxins on AChRs allows rational design of a-conotoxin analogues with improved potency or selectivity to nAChRs.

茯苓酸对人骨肉瘤细胞系MG-63的增殖凋亡、迁移侵袭影响及PERK/CCAAT信号通路调控作用

目的观察茯苓酸(PA)对人骨肉瘤细胞系MG-63增殖、迁移、凋亡和侵袭的影响,并探讨PA对蛋白激酶R样内质网激酶(PERK)/CCAAT增强子结合蛋白同源蛋白(CHOP)信号通路的调控作用。方法体外培养MG-63细胞,分为对照组、低浓度PA组(PA-L组)、中浓度PA组(PA-M组)、高浓度PA组(PA-H组)、高浓度PA+蛋白激酶R样内质网激酶(PERK)抑制剂GSK2606414组(PA-H+GSK2606414组),PA-L组、PA-M组及PA-H组分别用含20、40及80μmol/L PA的培养基培养,PA-H+GSK2606414组用含80μmol/L的PA和5μmol/L的GSK2606414培养基培养,对照组用空白培养基培养。分别于培养24、48、72 h时采用MTT法观察各组细胞增殖情况;培养24 h时采用细胞划痕实验观察各组细胞迁移情况;培养48 h时采用Transwell实验观察各组细胞侵袭情况;培养48 h时采用流式细胞术测算各组细胞凋亡率;培养48 h时,采用RT-qPCR法检测PERK及CHOP的mRNA表达,并采用WESTERN Blotting法检测PERK/CHOP信号通路相关蛋白及凋亡相关蛋白真核生物起始因子2α(eIF2α)、活化转录因子4(ATF4)、CHOP、BCL2相关X蛋白(Bax)及B淋巴细胞瘤-2(Bcl-2)。结果与对照组比较,PA-M组及PA-H组培养48与72 h时细胞OD_(570nm)值低、细胞迁移率低、细胞侵袭数少、细胞凋亡率高(P均<0.05);与PA-M组相比,PA-H组培养48及72 h时的细胞OD_(570nm)值低、细胞迁移率低、细胞侵袭数少、细胞凋亡率高(P均<0.05);与PA-H组相比,PA-H+GSK2606414组细胞培养48及72 h时的OD_(570nm)值高、细胞迁移率高、细胞侵袭数多、细胞凋亡率低(P均<0.05)。与对照组比较,PA-M组及PA-H组细胞PERK及CHOP mRNA相对表达量高,PERK及eIF2α磷酸化水平高,ATF4、CHOP、Bax蛋白相对表达量高,Bcl-2相对表达量低(P均<0.05);与PA-M组相比,PA-H组细胞PERK及CHOP mRNA相对表达量高,PERK及eIF2α磷酸化水平高,ATF4、CHOP、Bax蛋白相对表达量高,Bcl-2相对表达量低(P均<0.05);与PA-H组相比,PA-H+GSK2606414组细胞PERK及CHOP mRNA相对表达量低,PERK及eIF2α磷酸化水平低,ATF4、CHOP、Bax蛋白相对表达量低,Bcl-2相对表达量高(P均<0.05)。结论PA可抑制MG-63细胞的增殖、迁移及侵袭,促进细胞凋亡。PA可能通过激活PERK/CHOP信号通路,抑制MG-63细胞的增殖迁移及侵袭,促进MG-63细胞的凋亡。

CCAAT增强子结合蛋白β在骨关节炎中对基质金属蛋白酶表达调控的研究进展

骨关节炎是一种常见的关节退行性疾病,其发生机制复杂,目前尚未明确。研究发现,基质金属蛋白酶(Matrixmetallo proteinases,MMPs)的增多可引起骨关节炎中软骨细胞外基质降解进而导致进行性关节软骨受损,MMPs是诱导骨关节炎发病进程的主要因素,MMPs的表达受到多种因素调控。研究表明,CCAAT增强子结合蛋白β(CCAAT enhancer-binding protein-beta,C/EBPβ)作为一种转录因子在调控MMPs表达的过程中发挥着重要作用。本文就骨关节炎中C/EBPβ对基质金属蛋白酶家族的表达调控进行综述,以期为骨关节炎的防治提供新的研究思路。

膀胱癌100例血清Zeste基因增强子同源物2和信号传导蛋白3表达水平及诊断价值分析

目的探讨膀胱癌病人血清Zeste基因增强子同源物2(EZH2)和信号传导蛋白3(SMAD3)表达水平及临床意义。方法纳入江苏省人民医院宿迁医院于2021年1月至2022年12月收治的膀胱癌病人进行研究(100例),另选取同期于该院就诊的泌尿系统良性疾病病人作为良性疾病组(93例)以及健康体检者作为对照(100例)。采用Pearson相关性分析法分析膀胱癌病人血清中EZH2和SMAD3表达水平的相关性;采用logistic多因素回归分析法分析膀胱癌发生的影响因素;采用ROC曲线分析EZH2和SMAD3对膀胱癌的诊断效能。结果膀胱癌病人血清中EZH2(101.34±15.09)ng/L和SMAD3(226.53±25.94)ng/L表达水平均高于良性疾病组(85.96±11.23)ng/L、(203.11±22.18)ng/L和对照组(83.91±9.14)ng/L、(198.03±20.30)ng/L(均P<0.001);膀胱癌病人血清EZH2和SMAD3表达水平呈正相关(r=0.72,P<0.001);膀胱癌组年龄≥60岁(74/187)、有吸烟史的病人(76/166)所占比例均高于良性疾病组(65/187、55/166)及对照组(48/187、35/166)(均P<0.05);年龄、吸烟史、EZH2、SMAD3为发生膀胱癌的危险因素(P<0.05);以良性疾病组为对照,血清EZH2和SMAD3单独检测诊断膀胱癌的曲线下面积(AUC)分别为0.78、0.78,二者联合检测的AUC为0.85,优于各自单独检测(Z_(二者联合-EZH2)=2.81、Z_(二者联合-SMAD3)=2.68,P=0.009、0.007)。结论血清EZH2和SMAD3与膀胱癌的发生有关,二者联合对膀胱癌具有一定的诊断价值。

USP7-MDM2-p53信号轴对子宫内膜癌细胞增殖、凋亡和细胞周期的影响

目的:探讨泛素特异性蛋白酶7(USP7)调节Mdm2 p53结合蛋白同源物(MDM2)-p53轴对子宫内膜癌细胞增殖、凋亡和细胞周期的影响。方法:Western blot检测人子宫内膜癌组织、癌旁组织、人子宫内膜上皮细胞hEEC及人子宫内膜癌细胞系Ishikawa、HEC-1-A、KLE中USP7蛋白表达。将Ishikawa细胞分为NC组、P22077(USP7抑制剂)组、pcDNA组、pcDNA-MDM2组、P22077+pcDNA组、P22077+pcDNA-MDM2组,CCK-8法和克隆形成实验检测Ishikawa细胞增殖;流式细胞术检测Ishikawa细胞凋亡与细胞周期变化;Western blot检测Ishikawa细胞中USP7、细胞周期蛋白D1(CyclinD1)、周期素依赖性激酶2(CDK2)、Bcl-2相关X蛋白(Bax)、MDM2、p53蛋白表达。以RG7388(MDM2抑制剂)或PFT-α(p53抑制剂)与20μmol/L P22077共处理Ishikawa细胞48 h以验证USP7-MDM2-p53信号轴上下游关系。结果:USP7蛋白在子宫内膜癌组织和细胞中高表达,且Ishikawa细胞中USP7蛋白表达量最高,因此,选择Ishikawa细胞为研究对象。与NC组比较,P22077组Ishikawa细胞OD 450值、克隆形成率、S期和G 2/M期细胞数、USP7、CyclinD1、CDK2、MDM2蛋白表达降低,细胞凋亡率、G_(0)/G_(1)期细胞数、p53、Bax蛋白表达升高(P<0.05);与NC组、pcDNA组比较,pcDNA-MDM2组Ishikawa细胞OD 450值、克隆形成率、S期和G 2/M期细胞数、USP7、CyclinD1、CDK2、MDM2蛋白表达升高,细胞凋亡率、G_(0)/G_(1)期细胞数、p53、Bax蛋白表达降低(P<0.05);与P22077组、P22077+pcDNA组比较,P22077+pcDNA-MDM2组Ishikawa细胞OD 450值、克隆形成率、S期和G 2/M期细胞数、USP7、CyclinD1、CDK2、MDM2蛋白表达升高,细胞凋亡率、G_(0)/G_(1)期细胞数、p53、Bax蛋白表达降低(P<0.05)。p53为USP7-MDM2通路下游分子。结论:抑制USP7表达可能通过下调MDM2来激活p53进而抑制Ishikawa细胞增殖、促进细胞凋亡及周期停滞。

lncSIL通过EZH2/P21/CDK6信号通路负向调控TGF-β1诱导的肺泡上皮细胞间质转化

目的研究在转化生长因子β1(TGF-β1)诱导肺泡上皮细胞间质转化(EMT)进程中lncSIL的作用及其相关信号通路。方法采用Western blot法研究沉默lncSIL后对TGF-β1诱导EMT进程中细胞标志蛋白E-钙黏蛋白(E-cad)、α-平滑肌肌动蛋白(α-SMA)和Ⅰ型胶原蛋白(ColⅠ)表达的影响;通过RNA pulldown分析lncSIL相互作用蛋白,并检测过表达或沉默lncSIL后对其靶基因组蛋白赖氨酸N-甲基转移酶(EZH2)以及下游因子P21蛋白(P21)和细胞周期蛋白依赖性激酶6(CDK6)表达的影响,并结合流式细胞术分析lncSIL对细胞周期进程的作用。结果沉默lncSIL后,间质细胞标志蛋白α-SMA和Col I表达升高,肺泡上皮细胞标志蛋白E-cad表达下降;RNA pulldown实验结果显示EZH2是与lncSIL相互作用的靶蛋白,并且沉默lncSIL后EZH2表达升高,其下游基因P21表达下调,CDK6表达上调,同时S期细胞的数量显著升高;过表达lncSIL时,EZH2与CDK6表达下调,P21表达上调,同时S期细胞的数量明显降低。结论lncSIL通过负向调控EZH2/P21/CDK6信号通路抑制细胞周期进程进而抑制TGF-β1诱导的肺泡上皮细胞向间质转化。

温肺降浊方对血管性痴呆大鼠海马神经元的作用机制

目的:观察温肺降浊方对血管性痴呆(VaD)大鼠的作用机制。方法:建立VaD大鼠模型,随机分为模型组、西药组、温肺降浊方低剂量组、温肺降浊方中剂量组、温肺降浊方高剂量组,每组6只。另取6只大鼠设为假手术组,模型组和假手术组给予0.9%氯化钠溶液灌胃;西药组给予尼莫地平灌胃;温肺降浊方各剂量组给予相应剂量的温肺降浊汤灌胃。给药28 d后,采用Morris水迷宫实验评价各组大鼠学习记忆能力;HE及Nissl染色法进行组织病理学检测。采用RT-qPCR和Western blot检测各组大鼠海马组织中沉默信息调节因子1(SIRT1)/肌醇需求酶1α(IRE1α)/剪接型X-盒结合蛋白1(XBP1S)/CCAAT增强子结合蛋白同源蛋白(CHOP)信号通路相关mRNA和蛋白表达。结果:与假手术组比较,模型组大鼠逃避潜伏期明显延长,穿越平台次数则减少。与假手术组比较,模型组大鼠海马CA1区病理损伤严重,神经元细胞明显减少,尼氏小体数量明显减少,SIRT1 mRNA和蛋白表达则降低(均P<0.01)。与假手术组比较,模型组大鼠IRE1α、XBP1S、CHOP mRNA和XBP1S、CHOP蛋白及p-IRE1α/IRE1α明显升高(均P<0.01)。与模型组比较,温肺降浊方中剂量组、温肺降浊方高剂量组、西药组大鼠逃避潜伏期缩短,穿越平台次数增加(均P<0.05)。与模型组比较,西药组和温肺降浊方各剂量组大鼠海马CA1区病理损伤减轻,神经元细胞数量增加,尼氏小体数量增加。与模型组比较,西药组和温肺降浊方各剂量组SIRT1 mRNA和蛋白表达升高,且温肺降浊方高剂量组和西药组表达较高。IRE1α、XBP1S、CHOP mRNA和XBP1S、CHOP蛋白以及p-IRE1α/IRE1α水平降低,且温肺降浊方高剂量组和西药组水平更低(均P<0.01)。结论:温肺降浊方通过激活SIRT1/IRE1α/XBP1S/CHOP信号通路,减轻VaD大鼠海马神经元区病变,从而发挥改善VaD大鼠认知能力的作用。

甲基化SIM2、GNA12、CTGF在子痫前期孕妇中表达水平及其对疾病的预测价值

目的 探究子痫前期孕妇血浆中甲基化DNA的表达水平及对子痫前期发生的预测价值。方法 纳入2022年1-12月在该院确诊的82例子痫前期孕妇作为观察组,另外纳入82例健康孕妇作为对照组。提取患者游离总DNA,经过DNA亚硫酸氢盐修饰后通过实时荧光定量PCR反应(qRT-PCR)检测患者血浆中甲基化单意同源物2(SIM2)、结缔组织生长因子(CTGF)及鸟嘌呤核苷酸结合蛋白(GNA12)基因的相对表达水平,并采用相关性分析及受试者工作特征(ROC)曲线对各甲基化DNA预测子痫前期发生的价值进行评估。结果 观察组血浆甲基化SIM2、GNA12、CTGF相对表达水平均高于对照组(P<0.05),且重度子痫前期孕妇各甲基化DNA相对表达水平更高(P<0.05)。相关性分析结果表明,血浆甲基化SIM2、GNA12、CTGF相对表达水平与孕妇发生子痫前期均呈正相关(P<0.05)。ROC曲线分析结果表明,血浆甲基化SIM2、GNA12、CTGF相对表达水平单独及联合检测对预测孕妇子痫前期的效能均较好,且三者联合检测的预测效能最高(曲线下面积为0.888,95%CI:0.827~0.949)。结论 相较于健康孕妇,子痫前期孕妇血浆中甲基化SIM2、GNA12、CTGF相对表达水平均较高,且其与孕妇子痫前期的发生率呈正相关,血浆甲基化SIM2、GNA12及CTGF相对表达水平有望成为判断子痫前期是否发生的重要指标。

Zeste同源物2增强子在桥本甲状腺炎B淋巴细胞亚群中的表达及其抑制剂的治疗机制及效果研究

背景甲状腺自身抗体是诊断桥本甲状腺炎(HT)的标志,B淋巴细胞在HT的发病机制中发挥重要作用。Zeste同源物2增强子(EZH2)是一种表观遗传学蛋白,在淋巴细胞的发育与功能调控中扮演重要角色。目的本研究探讨EZH2在HT甲状腺组浆母细胞及浆细胞中的表达,进一步探讨EZH2抑制剂在实验性自身免疫甲状腺炎(EAT)模型中的治疗作用。方法收集北京大学第一医院2010—2020年6例行甲状腺手术的患者,取肿瘤对侧的甲状腺组织(HT及正常甲状腺组织各3例),通过RNA-seq筛选B淋巴细胞相关基因的表达情况;收集16例HT患者的甲状腺组织和8例健康对照(HD)甲状腺组织,分别利用免疫组化及免疫荧光验证EZH2在HT甲状腺组织中B淋巴细胞中的表达;收集25例HT甲状腺细针穿刺液(FNA)、19例HT外周血以及12例健康人外周血样本应用流式细胞分析检测EZH2在浆母细胞及浆细胞中的表达改变。将15只7周龄NOD.H-2^(h4)小鼠EAT模型分为对照组(n=5)、EAT无注射(n=5)或注射EZH2抑制剂GSK126处理组(10 mg/kg,腹腔注射3次/周,n=5),8周后观察甲状腺炎症程度及甲状腺球蛋白抗体(TgAb)水平的改变。结果RNA-seq结果显示,相较于正常甲状腺组织,HT甲状腺组织中EZH2水平上调,一些与B淋巴细胞表型相关的基因例如CD19、CD27、CD38、CD52相应增加。免疫组化结果显示,16例HT甲状腺组织标本中EZH2免疫组化染色均可在生发中心(GC)见到阳性细胞,呈强阳性,8例正常甲状腺组织染色中未观察到阳性细胞。HT甲状腺组织中EZH2染色高表达在GC区,EZH2特异性地表达在CD_(19)^(+)B淋巴细胞中。流式细胞术检测结果显示HT FNA样本中CD_(19)^(+)B淋巴细胞、浆母细胞及浆细胞比例均高于HD外周血、HT外周血样本(P<0.01),HT FNA样本中EZH2在CD_(19)^(+)B淋巴细胞、浆母细胞中的阳性比例高于HT外周血(P<0.005)。小鼠实验中,EAT组甲状腺的淋巴细胞浸润较对照组增加。GSK126处理组炎症程度评分和TgAb水平高于对照组,低于EAT组(P<0.001)。结论EZH2在HT甲状腺组织CD_(19)^(+)B淋巴细胞中表达异常升高,可能促进了B淋巴细胞分化成浆细胞进而促进自身抗体生成破坏甲状腺,EZH2抑制剂可以减缓EAT模型甲状腺炎症程度。浆母细胞中EZH2表达增加可能参与了HT的发病机制,EZH2可能成为治疗HT的新靶点,相关机制需要进一步深入研究。

幽门螺杆菌对CCAAT增强子结合蛋白α和Cx43表达的影响及其在胃癌发生中的作用

目的:探讨CCAAT增强子结合蛋白α(CCAAT enhancer binding proteinα,C/EBPα)和间隙连接蛋白43(connexin43,Cx43)表达改变在H.pylori致胃癌中的作用。方法:扩大培养不同胃黏膜上皮细胞株(GES-1细胞、AGS细胞、SGC-7901细胞);胃镜下采集H.pylori感染慢性非萎缩性胃炎患者6例、胃癌前病变和胃癌患者各12例胃黏膜组织;采用realtime PCR法检测上述细胞和组织中C/EBPα和Cx43 mRNA的表达;同时将东亚型Cag A+H.pylori与GES-1细胞共培养24和48 h为实验组,以不加H.pylori的GES-1细胞株为对照组,培养24和48 h;采用real-time PCR法和Western印迹检测C/EBPα和Cx43 m RNA和蛋白的表达。结果:C/EBPα和Cx43 m RNA在AGS细胞、SGC-7901细胞中的表达均显著低于GES-1细胞(均P<0.05),且两者在SGC-7901细胞中的表达量较AGS细胞更低(均P<0.05);C/EBPα和Cx43 m RNA在胃癌胃黏膜组织中的表达明显低于慢性非萎缩性胃炎(均P<0.05)和胃癌前病变(均P<0.05),C/EBPα与Cx43表达呈正相关(胃癌前病变:r=0.679;胃癌:r=0.792,均P<0.05);实验组24,48 h的C/EBPα和CX43表达量在转录及蛋白水平均低于对照组(均P<0.05),且48 h表达量均低于24 h(均P<0.05)。结论:H.pylori感染可下调胃黏膜上皮细胞C/EBPα和CX43的表达,这可能与胃癌发生有关。

CCAAT/增强子结合蛋白α对K562细胞分化和凋亡的影响及其机制

目的:研究CCAAT/增强子结合蛋白α(CCAAT/enhancer-binding protein-alpha,C/EBPα)对K562细胞株分化和凋亡的影响及对相关基因的调控,为慢性粒细胞白血病的治疗提供新的治疗靶点。方法:将C/EBPα表达质粒pEGFP-C/EBPα及空载体对照质粒pEGFP分别经阳离子脂质体2000介导转染K562细胞,用G418筛选出C/EBPα稳定表达细胞株。Wright-Giemsa染色观察细胞形态学变化,FCM分析细胞表面分化抗原CD11b的表达、细胞周期及细胞凋亡,电子显微镜观察细胞凋亡,RT-PCR和Western印迹法检测细胞中相关基因Per2、cyclin B1和C-myc的表达。结果:筛选得到稳定表达C/EBPα的细胞株pEGFP-C/EBPα-K562。与空载体转染组及对照组细胞相比,转染组K562细胞分化明显,同时粒系细胞表面分化抗原CD11b表达增加;细胞周期分析发现,转染组细胞中G2期细胞增多,与空载体组和对照组相比,差异有统计学意义(P<0.05),同时出现细胞凋亡峰。细胞凋亡检测结果显示,转染组细胞凋亡明显增加(21.1%),与空载体组(6.0%)和对照组(4.2%)比较,差异有统计学意义(P<0.05);电子显微镜观察发现,转染组细胞中出现染色质浓集、断裂和核固缩等现象,并见凋亡小体;RT-PCR和Western印迹法检测发现,C/EBPα明显上调Per2 mRNA和蛋白表达,抑制cyclinB1、C-myc mRNA和蛋白的表达。结论:C/EBPα能促进K562细胞分化,并诱导细胞凋亡,其机制可能是通过对细胞周期相关基因的调控来实现的。