SMAD specific E3 ubiquitin protein ligase 1 accelerates diabetic macular edema progression by WNT inhibitory factor 1

BACKGROUND Diabetic macular edema(DME)is the most common cause of vision loss in people with diabetes.Tight junction disruption of the retinal pigment epithelium(RPE)cells has been reported to induce DME development.SMAD-specific E3 ubiquitin protein ligase(SMURF)1 was associated with the tight junctions of cells.However,the mechanism of SMURF1 in the DME process remains unclear.AIM To investigate the role of SMURF1 in RPE cell tight junction during DME.METHODS ARPE-19 cells treated with high glucose(HG)and desferrioxamine mesylate(DFX)for establishment of the DME cell model.DME mice models were constructed by streptozotocin induction.The trans-epithelial electrical resistance and permeability of RPE cells were analyzed.The expressions of tight junction-related and autophagy-related proteins were determined.The interaction between insulin like growth factor 2 mRNA binding protein 2(IGF2BP2)and SMURF1 mRNA was verified by RNA immunoprecipitation(RIP).SMURF1 N6-methyladenosine(m6A)level was detected by methylated RIP.RESULTS SMURF1 and vascular endothelial growth factor(VEGF)were upregulated in DME.SMURF1 knockdown reduced HG/DFX-induced autophagy,which protected RPE cell tight junctions and ameliorated retinal damage in DME mice.SMURF1 activated the Wnt/β-catenin-VEGF signaling pathway by promoting WNT inhibitory factor(WIF)1 ubiquitination and degradation.IGF2BP2 upregulated SMURF1 expression in an m6A modification-dependent manner.CONCLUSION M6A-modified SMURF1 promoted WIF1 ubiquitination and degradation,which activated autophagy to inhibit RPE cell tight junctions,ultimately promoting DME progression.

TFE3融合基因相关肿瘤的临床病理研究进展

转录因子E3(translocation facor E3,TFE3)位于X染色体短臂11.22,属于MiT转录因子家族成员。TFE3有许多重要的生物学功能,如参与细胞的生长与维护、DNA依赖型的转录调控、蛋白质翻译时tRNA氨基化等。目前国内外关于TFE3的研究较少,主要集中在Xp11.2易位的相关肾细胞癌、腺泡状软组织肉瘤及血管周上皮细胞肿瘤等。进一步研究TFE3在肿瘤中的作用与分子机制具有重要意义。

Xp11.2易位/TFE3基因融合相关性肾癌1例及文献分析

目的:探讨Xp11.2易位/结合免疫球蛋白重链恒定区μ基因增强子的转录因子3(transcriptionfactor binding to IGHM enhancer 3,TFE3)基因融合相关性肾癌的临床病理特点。方法:报道1例Xp11.2易位/TFE3基因融合相关性肾癌,并进行临床资料分析、病理组织形态及免疫组织化学观察。并复习相关文献报道。结果:患者男,16岁,因右腰痛及无痛性全程血尿4 d,肿瘤大小约3.0 cm×2.5 cm×2.0 cm,切面灰褐色、质软;光镜下可见肿瘤主要由细胞间分界清楚的肿瘤细胞排列呈纤细乳头状。肿瘤细胞胞浆丰富、透亮,呈嗜酸性红染,核染色质呈泡状,核仁明显。核分裂少见。可见沙砾体状钙化。免疫组织化学结果显示:肾细胞癌(renal cell carcinoma,RCC)、TFE3阳性;细胞角蛋白(cytokeratin,CK)、上皮膜抗原(epithelial membrane antigen,EMA)及波形蛋白(vimentin)灶状阳性;白细胞分化抗原34(cluster of differentiation 34,CD34)、黑素瘤标记物抗体-45(melanoma marker antibody,HMB-45)及结蛋白(desmin)均为阴性。结论:Xp11.2易位/TFE3基因融合相关性肾癌少见,好发于儿童及青年人,临床常见肉眼血尿,免疫组织化学、荧光原位杂交及核型分析有助于诊断及鉴别诊断。治疗采用根治性肾脏全切术,预后不明确。

特发性间质性肺炎病人血清STAT3和FOXM1水平与病情程度及预后的关系研究

目的探讨特发性间质性肺炎(IIP)病人血清信号转导及转录激活因子3(STAT3)、叉头框转录因子M1(FOXM1)表达水平与其病情程度和预后的关系。方法选取2017年1月至2022年10月四川省建筑医院收治的298例IIP病人为IIP组,选取同时期该院收治的298例普通型间质性肺炎(UIP)病人为UIP组,另选取同时期在该院体检的280例健康人员为对照组。采用酶联免疫吸附测定(ELISA)检测血清STAT3与FOXM1表达水平,并采用全肺纤维化高分辨率CT(HRCT)评分评价IIP病情严重程度。分析三组受试者血清STAT3与FOXM1表达水平差异。对IIP组病人随访3个月,根据其生存情况分为预后良好组与预后不良组,分析预后不良与预后良好组IIP病人血清STAT3与FOXM1表达水平差异,并采用Spearman法分析IIP病人血清STAT3与FOXM1表达水平与全肺纤维化HRCT评分之间的关系。采用logistic回归分析IIP病人预后不良的影响因素,绘制受试者操作特征曲线(ROC曲线)评估血清STAT3与FOXM1表达水平对IIP病人预后不良的预测效能。结果IIP组、UIP组、对照组血清STAT3[(1.50±0.39)ng/L、(1.32±0.31)ng/L、(1.01±0.27)ng/L]、FOXM1[(34.56±5.64)ng/L、(22.69±4.11)ng/L、(15.51±3.94)ng/L]水平均依次降低(P<0.05)。IIP病人随访3个月共有41例病人死亡,预后不良发生率为13.76%(41/298);预后不良组IIP病人血清STAT3、FOXM1水平均高于预后良好组(P<0.05)。Spearman相关性分析表明,IIP病人血清STAT3、FOXM1水平均与全肺纤维化HRCT评分正相关(rs=0.65,rs=0.57;P<0.001)。另预后不良组年龄、Ⅱ型肺泡细胞表面抗原(KL-6)、白细胞计数、红细胞沉降率(ESR)、C反应蛋白(CRP)水平、全肺纤维化HRCT评分均高于预后良好组(P<0.05);第一秒用力呼气量(FEV1)、最大自主通气量(MVV)均低于预后良好组(P<0.05)。多因素logistic回归分析显示,年龄、KL-6、白细胞、ESR、CRP、STAT3、FOXM1水平、全肺纤维化HRCT评分均是导致IIP病人预后不良的危险因素(P<0.05),FEV1、MVV为保护因素(P<0.05)。ROC分析结果表明,血清STAT3、FOXM1水平联合预测IIP病人预后的灵敏度高于STAT3、FOXM1单独预测的灵敏度(χ^(2)=8.10、6.12,P=0.002、0.008);联合预测的曲线下面积(AUC)高于STAT3、FOXM1单独预测的AUC(Z=3.15、2.54,P=0.002、0.011)。结论IIP病人血清STAT3、FOXM1表达水平均上升,二者与IIP病情程度正相关,均对IIP病人预后具有良好的预测价值,且联合预测效能更高。

基于超高通量筛选的D-阿洛酮糖3-差向异构酶定向进化

D-阿洛酮糖是一种低热量的甜味剂,具有多种生理功能,如维持血糖平衡和调节脂质代谢等。目前,D-阿洛酮糖工业生产主要通过D-阿洛酮糖3-差向异构酶(D-allulose-3-epimerase,DAEase)催化D-果糖的差向异构反应实现,但DAEase的应用性能仍需进一步提升以满足日益增长的市场需求。定向进化作为一种有效的分子改造策略,其筛选方法是限制效率的关键因素之一。通过构建并优化D-阿洛酮糖特异型生物传感器,结合微孔板筛选,对来自Clostridium cellulolyticum H10的DAEase(Cc DAEase)突变体文库进行超高通量筛选,最终获得了比活提高14.6%的优势突变体H209Q,其最适温度为60℃,最适pH值为7.5,并进一步解析了该突变体的构效关系。该研究证明了转录因子型生物传感器可以作为一种有效的定向进化筛选工具,为进一步优化DAEase的性能提供了可能性,亦为D-阿洛酮糖的工业制备提供了理论依据和技术支撑。

Important Roles of Transcription Factors in Regulating Seed Oil Biosynthesis to Increase Plant Storage Lipid Content

In this article, the biosynthetic pathways of storage oil accumulation in oilseed plants were briefly introduced, and the transcription factors, such as B3 do- main supeffamily genes, lecl gene, wril gene etc., and their important role in oil accumulation regulation was mainly elucidated. Overexpession of transcription factors as feasible ways of genetic manipulation to increase oJl content in oilseed crops are promising in a long-term perspective.

Stattic通过调控记忆性CD4^(+)T细胞介导的急性排斥反应对小鼠同种异体心脏移植物存活的影响

目的探讨信号转导和转录激活因子3(STAT3)抑制剂Stattic对小鼠同种异体心脏移植排斥反应的影响及机制。方法将BALB/c小鼠(供体)皮肤移植至C57BL/6小鼠(受体),4周后取受体小鼠脾脏分离获得记忆性CD4^(+)T细胞(CD4^(+)Tm)。将C57BL/6小鼠脾脏淋巴细胞与CD4^(+)Tm进行混合淋巴细胞反应实验,EdU法检测Stattic对CD4^(+)Tm细胞增殖的影响。构建C57BL/6小鼠心脏移植(HTx)模型,实验分为:Non-HTx组、HTx组、Tm/HTx组和Tm/HTx+Stattic组。每日观察小鼠移植心脏存活情况;苏木素-伊红染色观察移植心脏组织病理情况;实时荧光定量聚合酶链反应检测心脏移植组织中干扰素(IFN)-γ、白细胞介素(IL)-2、IL-10和转化生长因子-β1(TGF-β1)信使RNA(mRNA)表达水平;酶联免疫吸附试验检测血清IFN-γ、IL-2、IL-10和TGF-β1含量;流式细胞术检测脾脏淋巴细胞中CD4^(+)Tm(CD4^(+)CD44^(+)CD62L^(+))水平;蛋白质印迹法检测移植心脏组织中STAT3和p-STAT3蛋白表达水平。结果当Stattic浓度超过2.5μmol/L时,可抑制CD4^(+)Tm细胞增殖。与HTx组比较,Tm/HTx组小鼠心脏移植物存活时间缩短,心脏移植组织病理损伤加重,血清IFN-γ和IL-2含量升高,IL-10和TGF-β1含量降低,移植心脏组织IFN-γ、IL-2 mRNA相对表达量升高,IL-10和TGF-β1 mRNA相对表达量降低,脾脏淋巴细胞中CD4^(+)Tm比例升高,移植心脏组织p-STAT3/STAT3比值升高(均为P<0.05)。与Tm/HTx组比较,Tm/HTx+Stattic组小鼠心脏移植物存活时间延长,心脏移植组织病理损伤减轻,血清中IFN-γ、IL-2含量降低,IL-10和TGF-β1含量升高,移植心脏组织中IFN-γ、IL-2 mRNA相对表达量降低,IL-10、TGF-β1 mRNA相对表达量升高,脾脏淋巴细胞中CD4^(+)Tm比例降低,移植心脏组织p-STAT3/STAT3比值降低(均为P<0.05)。结论Stattic可延长小鼠同种异体心脏移植物的存活时间,其机制可能与抑制CD4^(+)Tm介导的急性排斥反应有关。

FUBP3 mediates the amyloid-β-induced neuronal NLRP3 expression

Alzheimer's disease is characterized by deposition of amyloid-β,which forms extracellular neuritic plaques,and accumulation of hyperphosphorylated tau,which aggregates to form intraneuronal neurofibrillary tangles,in the brain.The NLRP3 inflammasome may play a role in the transition from amyloid-βdeposition to tau phosphorylation and aggregation.Because NLRP3 is primarily found in brain microglia,and tau is predominantly located in neurons,it has been suggested that NLRP3 expressed by microglia indirectly triggers tau phosphorylation by upregulating the expression of pro-inflammatory cytokines.Here,we found that neurons also express NLRP3 in vitro and in vivo,and that neuronal NLRP3 regulates tau phosphorylation.Using biochemical methods,we mapped the minimal NLRP3 promoter and identified FUBP3 as a transcription factor regulating NLRP3 expression in neurons.In primary neurons and the neuroblastoma cell line Neuro2A,FUBP3 is required for endogenous NLRP3 expression and tau phosphorylation only when amyloid-βis present.In the brains of aged wild-type mice and a mouse model of Alzheimer's disease,FUBP3 expression was markedly increased in cortical neurons.Transcriptome analysis suggested that FUBP3 plays a role in neuron-mediated immune responses.We also found that FUBP3 trimmed the 5′end of DNA fragments that it bound,implying that FUBP3 functions in stress-induced responses.These findings suggest that neuronal NLRP3 may be more directly involved in the amyloid-β-to–phospho-tau transition than microglial NLRP3,and that amyloid-βfundamentally alters the regulatory mechanism of NLRP3 expression in neurons.Given that FUBP3 was only expressed at low levels in young wild-type mice and was strongly upregulated in the brains of aged mice and Alzheimer's disease mice,FUBP3 could be a safe therapeutic target for preventing Alzheimer's disease progression.

TMED3 promotes prostate cancer via FOXO1a and FOXO3a phosphorylation

Background:Transmembrane emp24 trafficking protein 3(TMED3)is associated with the development of several tumors;however,whether TMED3 regulates the progression of prostate cancer remains unclear.Materials and Methods:Short hairpin RNA was performed to repress TMED3 in prostate cancer cells(DU145 cells)and in a prostate cancer mice model to determine its function in prostate cancer in vitro and in vivo.Results:In the present study,we found that TMED3 was highly expressed in prostate cancer cells.In vitro,shTMED3 treatment suppressed the proliferation,invasion,and migration and promoted the apoptosis of DU145 cells.Additionally,the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed a strong correlation between TMED3 and forkhead box O transcription factor(FOXO)pathway.Furthermore,TMED3 inhibition efficiently decreased FOXO1a and FOXO3a phosphorylation.In vivo,TMED3 downregulation suppressed the apoptosis,growth,and metastasis of prostate cancer cells via FOXO1a and FOXO3a.Conclusion:The present findings show that TMED3 participates in the regulation of prostate cancer progression via FOXO1a and FOXO3a phosphorylation,thereby revealing a novel mechanism underlying prostate cancer development and suggesting that TMED3 inhibition may serve as a novel strategy for prostate cancer treatment.

TKN3 affects cell expansion to regulate fruit development in tomato

Tomato is a model system for studying fleshy fruit development.After fertilization,cell division and expansion in the pericarp are crucial for fruit development and determine the final fruit size.TKN3 was found to be expressed in the tomato ovary wall/pericarp of zero to two days post-anthesis fruits as a KNOX I class member,but its function in fruit development was elusive.Here,we found that mutations of TKN3 by CRISPR/Cas9 caused fruit developmental defects,and fruit weight was dramatically reduced in the tkn3cr mutant.Histological observation of fruit pericarps revealed that mutation of TKN3 repressed cell expansion after fertilization,leading to flattened cells in the mesocarp and thereby thinner pericarps in red fruits.Moreover,tkn3cr mutants also displayed pleiotropic phenotypes including enlarged leaves and floral organs,indicating conserved functions in meristem maintenance and leaf development.Yeast two-hybrid and BiFC assays further showed that TKN3 could interact with Solyc10g086640(a homolog of Arabidopsis PNY),which has a similar expression pattern as TKN3.Genome-wide identification of genes regulated by TKN3 indicated that the auxin and gibberellin(GA)pathways might mediate the function of TKN3.Our works revealed that TKN3 controls cell expansion in pericarps,and provides new insights into the roles of KNOX proteins in fruit development.

Mesalazine alleviated the symptoms of spontaneous colitis in interleukin-10 knockout mice by regulating the STAT3/NF-κB signaling pathway

BACKGROUND Excessive endoplasmic reticulum(ER)stress in intestinal epithelial cells can lead to damage to the intestinal mucosal barrier,activate the signal transducer and activator of transcription 3(STAT3)/nuclear factor kappa B(NF-κB)signaling pathway,and exacerbate the inflammatory response,thus participating in the pathogenesis of ulcerative colitis(UC).Mesalazine is a commonly used drug in the clinical treatment of UC.However,further studies are needed to determine whether mesalazine regulates the ER stress of intestinal epithelial cells,downregulates the STAT3/NF-κB pathway to play a role in the treatment of UC.AIM To study the therapeutic effects of mesalazine on spontaneous colitis in interleukin-10(IL-10)-/-mice.METHODS The 24-week-old IL-10-/-mice with spontaneous colitis were divided into the model group and the 5-amino salicylic acid group.Littermates of wild-type mice of the same age group served as the control.There were eight mice in each group,four males and four females.The severity of symptoms of spontaneous colitis in IL-10-/-mice was assessed using disease activity index scores.On day 15,the mice were sacrificed.The colon length was measured,and the histopathological changes and ultrastructure of colonic epithelial cells were detected.The protein expressions of STAT3,p-STAT3,NF-κB,IκB,p-IκB,and glucoseregulated protein 78 were identified using Western blotting.The STAT3 and NF-κB mRNA expressions were identified using real-time polymerase chain reaction.The glucose-regulated protein 78 and C/EBP homologous protein expressions in colon sections were detected using immunofluorescence.RESULTS Mesalazine reduced the symptoms of spontaneous colitis in IL-10 knockout mice and the histopathological damage of colonic tissues,and alleviated the ER stress in epithelial cells of colitis mice.Western blotting and quantitative real-time polymerase chain reaction results showed that the STAT3/NF-κB pathway in the colon tissue of model mice was activated,suggesting that this pathway was involved in the pathogenesis of UC and might become a potential therapeutic target.Mesalazine could down-regulate the protein expressions of p-STAT3,NF-κB and p-IκB,and down-regulate the mRNA expression of STAT3 and NF-κB.CONCLUSION Mesalazine may play a protective role in UC by reducing ER stress by regulating the STAT3/NF-κB signaling pathway.

抑制TRAF6的E3泛素连接酶活性减轻野百合碱诱导的肺动脉高压大鼠肺血管重构

目的:探讨抑制肿瘤坏死因子受体相关因子6(TRAF6)的E3泛素连接酶活性对野百合碱(MCT)诱导的肺动脉高压(PH)大鼠肺血管重构以及相关信号通路的影响。方法:采用随机数字表法将42只SPF级健康成年雄性Sprague-Dawley大鼠分为4组:对照组(n=6)、MCT模型组(n=15)、C25-140(TRAF6特异性E3泛素连接酶活性抑制剂)组(n=6)和MCT+C25-140组(n=15)。MCT及MCT+C25-140组大鼠于实验开始时颈后皮下单次注射MCT60 mg/kg,建立PH模型,其他2组大鼠皮下注射5%DMSO作为对照。C25-140组及MCT+C25-140组大鼠于第14天、21天和28天腹腔注射9.8 mg/kg C25-140。第28天行超声心动图检测评估大鼠肺动脉压力和心室收缩力变化,之后对大鼠进行安乐死并取肺组织。通过HE染色和α-平滑肌肌动蛋白(α-SMA)免疫荧光染色评估大鼠肺血管形态;采用免疫共沉淀检测大鼠肺动脉平滑肌细胞(PASMCs)中信号转导及转录激活因子3(STAT3)的K63泛素化水平;Western blot检测大鼠肺组织中TRAF6、STAT3、p-STAT3及cyclin D1的表达水平;免疫荧光染色观察大鼠肺血管TRAF6和STAT3的共定位情况。结果:(1)与对照组比较,MCT组大鼠肺动脉血流加速时间(PAAT)和三尖瓣环平面收缩期位移(TAPSE)明显减少(P<0.05),血管中膜厚度明显增加(P<0.05),α-SMA免疫荧光染色显示肺小血管明显肌化,提示造模成功。(2)与对照组相比,PH大鼠PASMCs中STAT3的K63泛素化明显升高。(3)MCT干预后28天,大鼠肺组织中TARF6、p-STAT3/STAT3比值及cyclin D1水平相对于对照组显著升高(P<0.05);与MCT组相比,MCT+C25-140组大鼠PAAT、TAPSE明显上升(P<0.05),血管中膜厚度明显减小(P<0.05)。给予C25-140处理后,肺组织中TARF6、p-STAT3/STAT3比值及cyclin D1水平相对于MCT组显著降低(P<0.05)。(4)免疫荧光染色的结果显示MCT组大鼠肺小动脉中膜TRAF6与STAT3存在显著共定位,C25-140处理能显著抑制两者的相互作用。结论:抑制TRAF6的E3泛素连接酶活性可降低肺血管STAT3的磷酸化,下调cyclin D1表达,而且能减缓PH大鼠肺动脉中膜增厚,减轻肺血管重构。

GATA-3 promotes Th2 responses through three different mechanisms： induction of Th2 cytokine production, selective growth of Th2 cells and inhibition of Thl cell-specific factors

Naive CD4 T cells can differentiate into at least two different types ofT helpers, Thl and Th2 cells. Th2 cells, capable of producing IL-4, IL-5 and IL-13, are involved in humoral immunity against extracellular pathogens and in the induction of asthma and other allergic diseases. In this review, we summarize recent reports regarding the transcription factors involved in Th2 differentiation and cell expansion, including StatS, Gfi- 1 and GATA-3. Stats activation is necessary and sufficient for IL-2-mediated function in Th2 differentiation. Enhanced Stats signaling induces Th2 differentiation independent of IL-4 signaling; although it does not up-regulate GATA-3 expression, it does require the presence of GATA-3 for its action. Gfi-1, induced by IL-4, promotes the expansion of GATA-3-expressing cells. Analysis of conditional Gata3 knockout mice confirmed the critical role of GATA-3 in Th2 cell differentiation （both IL-4 dependent and IL-4 independent） and in Th2 cell proliferation and also showed the importance of basal GATA-3 expression in inhibiting Thl differentiation.

Basic transcription factor 3 is involved in gastric cancer development and progression

AIM: To further analyse cancer involvement of basic transcription factor 3 (BTF3) after detection of its upregulation in gastric tumor samples. METHODS: BTF3 transcription rates in human gastric tumor tissue samples (n = 20) and adjacent normal tissue (n = 18) specimens as well as in the gastric cancer cell lines AGS, SGC-7901, MKN-28, MKN-45 and MGC803 were analyzed via quantitative real-time polymerase chain reaction. The effect of stable BTF3 silencing via infection with a small interfering RNA (siRNA)-BTF3 expressing lentivirus on SGC-7901 cells was measured via Western blotting analysis, proliferation assays, cell cycle and apoptosis profiling by flow cytometry as well as colony forming assays with a Cellomic Assay System. RESULTS: A significant higher expression of BTF3 mRNA was detected in tumors compared to normal gastric tissues (P < 0.01), especially in section tissues from female patients compared to male patients, and all tested gastric cancer cell lines expressed high levels of BTF3. From days 1 to 5, the relative proliferation rates of stable BTF3-siRNA transfected SGC7901 cells were 82%, 70%, 57%, 49% and 44% compared to the control, while the percentage of cells arrested in the G 1 phase was significantly decreased (P = 0.000) and the percentages of cells in the S (P = 0.031) and G 2 /M (P = 0.027) phases were significantly increased. In addition, the colony forming tendency was significantly decreased (P = 0.014) and the apoptosis rate increased from 5.73% to 8.59% (P = 0.014) after BTF3 was silenced in SGC7901 cells. CONCLUSION: BTF3 expression is associated with enhanced cell proliferation, reduced cell cycle regulation and apoptosis and its silencing decreased colony forming and proliferation of gastric cancer cells.

DI-3-n-butylphthalide exerts neuroprotective effects by modulating hypoxia-inducible factor 1-alpha ubiquitination to attenuate oxidative stress-induced apoptosis

DI-3-n-butylphthalide is used to treat mild and moderate acute ischemic stroke.However,the precise underlying mechanism requires further investigation.In this study,we investigated the molecular mechanism of DI-3-n-butylphthalide action by various means.We used hydrogen peroxide to induce injury to PC12cells and RAW264.7 cells to mimic neuronal oxidative stress injury in stroke in vitro and examined the effects of DI-3-n-butylphthalide.We found that DI-3-nbutylphthalide pretreatment markedly inhibited the reduction in viability and reactive oxygen species production in PC12 cells caused by hydrogen peroxide and inhibited cell apoptosis.Furthermore,DI-3-n-butylphthalide pretreatment inhibited the expression of the pro-apoptotic genes Bax and Bnip3.DI-3-nbutylphthalide also promoted ubiquitination and degradation of hypoxia inducible factor 1α,the key transcription factor that regulates Bax and Bnip3 genes.These findings suggest that DI-3-n-butylphthalide exhibits a neuroprotective effect on stroke by promoting hypoxia inducible factor-1α ubiquitination and degradation and inhibiting cell apoptosis.

Expression of p-STAT3 and vascular endothelial growth factor in MNNG-induced precancerous lesions and gastric tumors in rats

AIM: To investigate the dynamic expression of p-signal transducer and activator of transcription 3 (STAT3) and vascular endothelial growth factor (VEGF) in the formation of gastric tumors induced by drinking water containing N-methyl-N’-nitro-N-nitrosoguanidine (MNNG) in Wistar rats. METHODS: One hundred and twenty Wistar rats were randomly divided into two groups (60 in each group): Control group and Model group. The rats in each group were then randomly divided into three groups (20 in each group): C/M15, C/M25 and C/M40 (15, 25 and 40 represent the number of feeding weeks from termination). Rats in the control group received normal drinking water and rats in the model group received drinking water containing 100 μg/mL MNNG. Stomach tissues were collected at the end of the 15th, 25th and 40th week, respectively, for microscopic measurement using hematoxylin and eosin staining. The expression of p-STAT3 and VEGF in different pathological types of gastric tissue, including normal, inflammation, atrophy, hyperplasia and gastric stromal tumor, was observed by immunohistochemistry and Western blot, and the corelation between p-STAT3 and VEGF was analyzed. RESULTS: (1) The expression of p-STAT3 in tissue with gastritis, atrophy, dysplasia and gastric stromal tumor were significantly increased in the model group compared with the control group (2.5 ± 1.0, 2.75 ± 0.36, 6.2 ± 0.45, 5.67 ± 0.55 vs 0.75 ± 0.36, P = 0.026, 0.035, 0.001, 0.002, respectively); the expression of p-STAT3 in tissue with dysplasia was higher than that in samples with gastritis or atrophy (6.2 ± 0.45 vs 2.5 ± 1.0, P = 0.006; 6.2 ± 0.45 vs 2.75 ± 0.36, P = 0.005, respectively); however, the expression of p-STAT3 in gastritis and atrophy was not significantly different (P > 0.05); (2) the expression of VEGF in tissue with gastritis, atrophy, dysplasia and gastric stromal tumor was significantly increased in the model group compared with normal gastric mucosa; and the expression of VEGF in tissue with dysplasia was higher than that in tissue with inflammation and atrophy (10.8 ± 1.96 vs 7.62 ± 0.25, P = 0.029; 10.8 ± 1.96 vs 6.26 ± 0.76, P = 0.033, respectively); similarly, the expression of VEGF in tissue with gastritis and atrophy was not significantly different (P > 0.05); and (3) the expression of VEGF was positively correlated with p-STAT3. CONCLUSION: p-STAT3 plays an important role in gastric cancer formation by regulating the expression of VEGF to promote the progression of gastric tumor from gastritis.

Genome-wide analysis of the B3 transcription factors reveals that RcABI3/VP1 subfamily plays important roles in seed development and oil storage in castor bean(Ricinus communis)

The B3 transcription factors(TFs)in plants play vital roles in numerous biological processes.Although B3 genes have been broadly identified in many plants,little is known about their potential functions in mediating seed development and material accumulation.Castor bean(Ricinus communis)is a non-edible oilseed crop considered an ideal model system for seed biology research.Here,we identified a total of 61 B3 genes in the castor bean genome,which can be classified into five subfamilies,including ABI3/VP1,HSI,ARF,RAV and REM.The expression profiles revealed that RcABI3/VP1 subfamily genes are significantly up-regulated in the middle and later stages of seed development,indicating that these genes may be associated with the accumulation of storage oils.Furthermore,through yeast one-hybrid and tobacco transient expression assays,we detected that ABI3/VP1 subfamily member RcLEC2 directly regulates the transcription of RcOleosin2,which encodes an oil-body structural protein.This finding suggests that RcLEC2,as a seed-specific TF,may be involved in the regulation of storage materials accumulation.This study provides novel insights into the potential roles and molecular basis of B3 family proteins in seed development and material accumulation.

Silencing the SLB3 transcription factor gene decreases drought stress tolerance in tomato

BRI1-EMS-SUPPRESSOR 1(BES1)transcription factor is closely associated with the brassinosteroid(BR)signaling pathway and plays an important role in plant growth and development.SLB3 is a member of BES1 transcription factor family and its expression was previously shown to increase significantly in tomato seedlings under drought stress.In the present study,we used virus-induced gene silencing(VIGS)technology to downregulate SLB3 expression to reveal the function of the SLB3 gene under drought stress further.The downregulated expression of SLB3 weakened the drought tolerance of the plants appeared earlier wilting and higher accumulation of H2 O2 and O2^–·,decreased superoxide dismutase(SOD)activity,and increased proline(PRO)and malondialdehyde(MDA)contents and peroxidase(POD)activity.Quantitative real-time PCR(qRT-PCR)analysis of BR-related genes revealed that the expression of SlCPD,SlDWARF and BIN2-related genes was significantly upregulated in SLB3-silenced seedlings under drought stress,but that the expression of TCH4-related genes was downregulated.These results showed that silencing the SLB3 gene reduced the drought resistance of tomato plants and had an impact on the BR signaling transduction which may be probably responsible for the variation in drought resistance of the tomato plants.

Mechanism of ELL-associated factor 2 and vasohibin 1 regulating invasion,migration,and angiogenesis in colorectal cancer

BACKGROUND As a novel endogenous anti-angiogenic molecule, vasohibin 1(VASH1) is not only expressed in tumor stroma, but also in tumor tissue. Moreover, studies have shown that VASH1 may be a prognostic marker in colorectal cancer(CRC). Knockdown of VASH1 enhanced transforming growth factor-β1(TGF-β1)/Smad3 pathway activity and type Ⅰ/Ⅲ collagen production. Our previous findings suggest that ELL-associated factor 2(EAF2) may play a tumor suppressor and protective role in the development and progression of CRC by regulating signal transducer and activator of transcription 3(STAT3)/TGF-β1 signaling pathway. However, the functional role and mechanism of VASH1-mediated TGF-β1 related pathway in CRC has not been elucidated.AIM To investigate the expression of VASH1 in CRC and its correlation with the expression of EAF2. Furthermore, we studied the functional role and mechanism of VASH1 involved in the regulation and protection of EAF2 in CRC cells in vitro.METHODS We collected colorectal adenocarcinoma and corresponding adjacent tissues to investigate the clinical expression of EAF2 protein and VASH1 protein in patients with advanced CRC. Following, we investigated the effect and mechanism of EAF2 and VASH1 on the invasion, migration and angiogenesis of CRC cells in vitro using plasmid transfection.RESULTS Our findings indicated that EAF2 was down-regulated and VASH1 was upregulated in advanced CRC tissue compared to normal colorectal tissue. KaplanMeier survival analysis showed that the higher EAF2 Level group and the lower VASH1 Level group had a higher survival rate. Overexpression of EAF2 might inhibit the activity of STAT3/TGF-β1 pathway by up-regulating the expression of VASH1, and then weaken the invasion, migration and angiogenesis of CRC cells.CONCLUSION This study suggests that EAF2 and VASH1 may serve as new diagnostic and prognostic markers for CRC, and provide a clinical basis for exploring new biomarkers for CRC. This study complements the mechanism of EAF2 in CRC cells, enriches the role and mechanism of CRC cellderived VASH1, and provides a new possible subtype of CRC as a therapeutic target of STAT3/TGF-β1 pathway.

Chlorophyllase is transcriptionally regulated by CsMYB308/CsDOF3 in young leaves of tea plant

Chlorophyll contributes to tea coloration, which is an important factor in tea quality. Chlorophyll metabolism is induced by light, but the transcriptional regulation responsible for light-induced chlorophyll metabolism is largely unknown in tea leaves. Here, we characterized a chlorophyllase1 gene CsCLH1 from young tea leaves and showed it is essential for chlorophyll metabolism, using transient overexpression and silencing in tea leaves and ectopic overexpression in Arabidopsis. CsCLH1 was significantly induced by high light. The DOF protein CsDOF3, an upstream direct regulator of CsCLH1, was also identified. Acting as a nuclear-localized transcriptional factor, CsDOF3 responded for light and repressed CsCLH1 transcription and increased chlorophyll content by directly binding to the AAAG cis-element in the CsCLH1 promoter. CsDOF3was able to physically interact with the R2R3-MYB transcription factor CsMYB308 and interfere with transcriptional activity of CsCLH1. In addition, CsMYB308 binds to the CsCLH1 promoter to enhance CsCLH1 expression and decrease chlorophyll content. CsMYB308 and CsDOF3 act as an antagonistic complex to regulate CsCLH1 transcription and chlorophyll in young leaves. Collectively, the study adds to the understanding of the transcriptional regulation of chlorophyll in tea leaves in response to light and provides a basis for improving the appearance of tea.