An acquisition system of digital nuclear signal processing for the algorithm development

A principle and method of constructing the digital acquisition system is presented in this work,which is convenient for the study on the theories and algorithms of digital nuclear signal processing.The hardware system of the digital acquisition system consists of front-end controller,waveform digitizer and PC workstation,on which the software system has been developed based on Visual C++under Windows environment.The alterable-frequency sampling(AFS)algorithm and the alterable-frequency trapezoidal filter(AFTF)algorithm have also been studied in the real-time environment,along with a digital nuclear spectrum acquisition system being set up based on the new algorithms and theγ-ray spectra of 241Am being shown.A useful experimental platform could be provided by this work for the successive work such as the development of global digitized nuclear measurement system and the study of digital nuclear signal processing.

Presence of a long nuclear-localization signal sequence in homeodomain transcription factor Nkx 1.2

Homeodomains,a 60-amino acid sequence encoded by 180 nucleotides,are highly conserved DNA-binding motifs that are present in a variety of transcription factors in species ranging from yeast to humans.The NKX proteins belong to the homeodomain(HD)-containing transcription factor family.They play vital roles in the regulation of morphogenesis.NKX1-2 is one member of the NKX subfamily.At present,information about its nuclear localization signal(NLS)sequence is limited.We studied the NLS sequence of zebrafish Nkx1.2 by introducing sequence changes such as deletion,mutation,and truncation,and identified an NLS motif(QNRRTKWKKQ)that is localized at the C-terminus of the homeodomain.Moreover,the deletion of two amino acid residues(RR)in this NLS motif prevents Nkx1.2 from entering the nucleus,indicating that the two amino acids are essential for Nkx1.2 nuclear localization.However,the NLS motif alone is unable to target cytoplasmic protein glutathione S-transferase(GST)to the nucleus.An intact homeodomain is necessary for mediating the complete nuclear transport of cytoplasmic protein.Unlike most nuclear import proteins with short NLS sequences,a long NLS is present in zebrafish Nkx1.2.We also demonstrated that the sequences of homeodomain of NKX1.2 are well conserved among different species.This study is informative to verify the function of the NKX1.2 protein.

Identification and characterization of a novel bipartite nuclear localization signal in the hepatitis B virus polymerase

AIM: To characterize the nuclear import of hepatitis B virus (HBV) polymerase (P) and its relevance for the viral life cycle.METHODS: Sequence analysis was performed to predict functional motives within P. Phosphorylation of P was analyzed by in vitro phosphorylation. Phosphorylation site and nuclear localization signal (NLS) were destroyed by site directed mutagenesis. Functionality of the identified NLS was analyzed by confocal fluorescence microscopy and characterizing the karyopherin binding. Relevance of the structural motives for viral life cycle was studied by infection of primary Tupaia hepatocytes with HBV.RESULTS: We identified by sequence alignment and functional experiments a conserved bipartite NLS containing a casein kinase II (CKII) phosphorylation site located within the terminal protein domain (TP) of the HBV polymerase. Inhibition of CKII impairs the functionality of this NLS and thereby prevents the nuclear import of the polymerase. Binding of the import factor karyopherin-α2 to the polymerase depends on its CKII-mediated phosphorylation of the bipartite NLS. In HBV-infected primary Tupaia hepatocytes CKII inhibition in the early phase (post entry phase) of the infection process prevents the establishment of the infection.CONCLUSION: Based on these data it is suggested that during HBV infection the final import of the genome complex into the nucleus is mediated by a novel bipartite NLS localized in the TP domain of HBV polymerase.

Digitalization of inverting filter shaping circuit for nuclear pulse signals

In the design of filter shaping circuits for nuclear pulse signals,inverting filter shaping circuits perform better than non-inverting filter shaping circuits.Because these circuits facilitate changing the phase of a pulse signal,they are widely used in processing nuclear pulse signals.In this study,the transfer functions of four types of inverting filter shaping circuits,namely the common inverting filter shaping,improved inverting filter shaping,multiple feedback low-pass filter shaping,and third-order multiple feedback low-pass filter shaping,in the Laplacian domain,are derived.We establish the numerical recursive function models and digitalize the four circuits,obtain the transfer functions in the Z domain,and analyze the filter performance and amplitude-frequency response characteristics in the frequency domain.Based on the actual nuclear pulse signal of the Si-PIN detector,we realize four types of inverting digital shaping.The results show that under the same shaping parameters,the common inverting digital shaping has better amplitude extraction characteristics,the third-order multiple feedback low-pass digital shaping has better noise suppression performance,and the multiple feedback digital shaping takes into account both pulse amplitude extraction and noise suppression performance.

Developing high-efficiency base editors by combining optimized synergistic core components with new types of nuclear localization signal peptide

The clustered regularly interspaced short palindromic repeats(CRISPR)–CRISPR-associated protein(Cas) system has been widely used for genome editing. In this system, the cytosine base editor(CBE) and adenine base editor(ABE) allow generating precise and irreversible base mutations in a programmable manner and have been used in many different types of cells and organisms. However, their applications are limited by low editing efficiency at certain genomic target sites or at specific target cytosine(C) or adenine(A) residues. Using a strategy of combining optimized synergistic core components, we developed a new multiplex super-assembled ABE(sABE) in rice that showed higher base-editing efficiency than previously developed ABEs. We also designed a new type of nuclear localization signal(NLS) comprising a FLAG epitope tag with four copies of a codon-optimized NLS(F4NLS^(r2)) to generate another ABE named F4NLS-sABE. This new NLS increased editing efficiency or edited additional A at several target sites. A new multiplex super-assembled CBE(sCBE) and F4NLS^(r2) involved F4NLS-sCBE were also created using the same strategy. F4NLS-sCBE was proven to be much more efficient than sCBE in rice. These optimized base editors will serve as powerful genome-editing tools for basic research or molecular breeding in rice and will provide a reference for the development of superior editing tools for other plants or animals.

Identification and Characterization of Nuclear Localization Signals within the Nucleocapsid Protein VP15 of White Spot Syndrome Virus

The nucleocapsid protein VP15 of white spot syndrome virus (WSSV) is a basic DNA-binding protein. Three canonical bipartite nuclear localization signals (NLSs), called NLS1 (aa 11-27), NLS2 (aa 33-49) and NLS3 (44-60), have been detected in this protein, using the ScanProsite computer program. To determine the nuclear localization sequence of VP15, the full-length open reading frame, or the sequence of one of the three NLSs, was fused to the green fluorescent protein (GFP) gene, and transiently expressed in insect Sf9 cells. Transfection with full-length VP15 resulted in GFP fluorescence being distributed exclusively in the nucleus. NLS1 alone could also direct GFP to the nucleus, but less efficiently. Neither of the other two NLSs (NLS2 and 3) was functional when expressed alone, but exhibited similar activity to NLS1 when they were expressed as a fusion peptide. Furthermore, a mutated VP15, in which the two basic amino acids (11RR12) of NLS1 were changed to two alanines (11AA12), caused GFP to be localized only in the cytoplasm of Sf9 cells. These results demonstrated that VP15, as a nuclear localization protein, needs cooperation between its three NLSs, and that the two residues (11RR12) of NLS1 play a key role in transporting the protein to the nucleus.

Atsttrin reduces lipopolysaccharide-induced neuroinflammation by inhibiting the nuclear factor kappa B signaling pathway

Progranulin is closely related to neuronal survival in a neuroinflammatory mouse model and attenuates inflammatory reactions. Atsttrin is an engineered protein composed of three progranulin fragments and has been shown to have an effect similar to that of progranulin. Atsttrin has anti-inflammatory actions in multiple arthritis mouse models, and it protects against further arthritis development. However, whether Atsttrin has a role in neuroinflammation remains to be elucidated. In this study, we produced a neuroinflammatory mouse model by intracerebroventricular injection of 1 μL lipopolysaccharide(10 μg/μL). Atsttrin(2.5 mg/kg) was administered via intraperitoneal injection every 3 days over a period of 7 days before intracerebroventricular injection of 1 μL lipopolysaccharide(10 μg/μL). In addition, astrocyte cultures were treated with 0, 100 or 300 ng/mL lipopolysaccharide, with 200 ng/mL Atsttrin simultaneously. Immunohistochemistry, enzyme-linked immunosorbent assay and real-time reverse transcription-polymerase chain reaction were performed to examine the protein and mRNA levels of inflammatory mediators and to assess activation of the nuclear factor kappa B signaling pathway. Progranulin expression in the brain of wild-type mice and in astrocyte cultures was increased after lipopolysaccharide administration. The protein and mRNA expression levels of tumor necrosis factor-α, interleukin-1β and inducible nitric oxide synthase were increased in the brain of progranulin knockout mice after lipopolysaccharide administration. Atsttrin treatment reduced the lipopolysaccharide-induced increase in the protein and mRNA levels of tumor necrosis factor-α, interleukin-1β, matrix metalloproteinase-3 and inducible nitric oxide synthase in the brain of progranulin knockout mice. Atsttrin also reduced the expression of cyclooxygenase-2, inducible nitric oxide synthase and matrix metalloproteinase 3 mRNA in lipopolysaccharide-treated astrocytes in vitro, and decreased the concentration of tumor necrosis factor α and interleukin-1β in the supernatant. Furthermore, Atsttrin significantly reduced the levels of phospho-nuclear factor kappa B inhibitor α in the brain of lipopolysaccharide-treated progranulin knockout mice and astrocytes, and it decreased the expression of nuclear factor kappa B2 in astrocytes. Collectively, our findings show that the anti-neuroinflammatory effect of Atsttrin involves inhibiton of the nuclear factor kappa B signaling pathway, and they suggest that Atsttrin may have clinical potential in neuroinflammatory therapy.

松果菊苷对尿毒症大鼠肾损伤的影响及机制

目的研究松果菊苷(ECH)对尿毒症(URE)大鼠肾损伤的影响及机制。方法采用5/6肾切除法建立URE大鼠模型。建模成功的大鼠分为尿毒症(URE)组、ECH低剂量[10 mg/(kg·d)]组、ECH中剂量组[20 mg/(kg·d)]、ECH高剂量组[40 mg/(kg·d)]和ECH高剂量+茴香霉素[p38丝裂原活化蛋白激酶(p38 MAPK)信号通路激活剂]组[ECH-H+Ani组,40 mg/(kg·d)ECH+2 mg/(kg·d)茴香霉素],另设假手术组,每组12只。各药物组灌胃相应的ECH,ECH-H+Ani组再尾静脉注射茴香霉素,每天1次,连续给药8周。检测大鼠血清中肿瘤细胞因子α(TNF-α)、白细胞介素1β(IL-1β)、IL-6、血尿素氮(BUN)、β2-微球蛋白(β2-MG)、血肌酐(Scr)、中性粒细胞明胶酶相关载脂蛋白(NGAL)、肾损伤分子1(KIM-1)、胱抑素C(Cys-C)水平,24 h尿蛋白(24 h UP)和肾组织中丙二醛(MDA)水平、超氧化物歧化酶(SOD)活性;观察肾组织病理学变化;检测大鼠肾组织中α-平滑肌肌动蛋白(α-SMA)、E-上皮钙黏素(E-cadherin)阳性表达率和p38 MAPK、核因子κB(NF-κB)p65的磷酸化水平。结果与URE组相比,ECH各剂量组大鼠肾小球肿胀及上皮细胞损伤坏死明显减轻,炎症细胞浸润明显减少;肾损伤评分和TNF-α、IL-1β、IL-6、BUN、Scr、β2-MG、24 h UP、NGAL、KIM-1、Cys-C、MDA水平及α-SMA阳性表达率、p38 MAPK和NF-κB p65的磷酸化水平均呈剂量依赖性降低而SOD活性和E-cadherin阳性表达率均呈剂量依赖性升高(P<0.05)。茴香霉素可显著逆转高剂量ECH对URE大鼠肾损伤及相关指标的改善作用(P<0.05)。结论ECH可能通过抑制p38 MAPK/NF-κB信号通路激活来抑制URE大鼠的炎症反应和氧化应激反应,增强肾功能,改善肾损伤。

针刺对干眼兔角膜形态学及角膜组织NF-κB信号通路的影响

目的 探讨针刺对干眼兔角膜形态学及角膜组织NF-κB信号通路的影响,分析针刺对干眼的作用机制。方法 取雌雄不拘的健康新西兰兔24只,随机分为空白组、模型组、针刺组、假针刺组,每组6只。空白组为正常对照组,不加任何处理;其余3组动物每天800、 1100、1400和1800时于皮下注射氢溴酸东莨菪碱2.0 mg·kg-1,连续35 d直至实验结束。假针刺组:于造模后第22天给予假针刺治疗(睛明BL1、攒竹BL2、丝竹空SJ23、太阳穴EX-HN5、瞳子髎GB1),钝针头点刺穴位,不刺进穴位,每天1次,连续14 d。针刺组:于造模成功后第22天给予针刺治疗,穴位同假针刺组。造模后第0、21、28、35天分别进行角膜荧光素染色,第35天进行角膜共焦显微镜检查,之后处死动物,在光学显微镜、透射电子显微镜下观察角膜形态学变化,采用Western blot检测角膜组织NF-κB蛋白的表达。结果 与模型组相比,造模后第28、35天,针刺组、空白组兔角膜荧光素染色评分均减小,差异均有统计学意义(均为P<0.05)。造模后第35天共焦显微镜检查结果显示,模型组和假针刺组与其他组相比,兔角膜基质层出现大量球状免疫细胞和边界不清大小不规律的活化基质层细胞,可见具有不规则细胞间间隙的区域,存在炎症;针刺组基质层细胞形态得到改善,细胞呈轻微激活状态,角膜神经形态未见明显异常。造模后第35天光学显微镜检查结果显示,模型组和假针刺组兔角膜组织表面可见角化过度的扁平上皮细胞,淋巴细胞浸润,局灶上皮细胞层数增多,表面上皮细胞脱落;针刺组角膜上皮有接近4~6层上皮细胞,上皮脱落减少,与模型组相比,淋巴细胞浸润减少。造模后第35天透射电子显微镜检查结果显示,模型组和假针刺组兔角膜上皮细胞出现异常的微绒毛结构和上皮细胞缺失,细胞间隙增宽,粗面内质网严重扩张,桥粒解体伴随线粒体肿胀;针刺组上皮细胞微绒毛结构稀疏且短,仍见局部缺失,粗面内质网轻度扩张,线粒体未见明显肿胀。造模后第35天Western blot检测结果显示,与空白组相比,模型组、假针刺组p-NF-κB p65表达均上调(均为P<0.05);与模型组、假针刺组相比,针刺组p-NF-κB p65表达均下调(均为P<0.05)。结论 针刺可以抑制NF-κB信号通路从而发挥抗炎作用,改善兔干眼模型角膜炎症和损伤。

黄连素治疗大鼠种植体周围炎的机制

目的探讨黄连素治疗大鼠种植体周围炎的作用以及对Toll样受体4(Toll-like receptor 4,TLR4)/核因子κB(nuclear factorκB,NF-κB)信号通路的影响。方法建立SD大鼠种植体周围炎大鼠模型,随机分为模型组、黄连素低剂量组、黄连素高剂量组和抗生素组,另设阴性对照组。黄连素低、高剂量组予以100、200 mg·kg^(-1)黄连素,抗生素组予以200 mg·kg^(-1)阿莫西林胶囊和100 mg·kg^(-1)甲硝唑片,模型组和阴性对照组予以等体积生理盐水,连续干预4周。观察各组大鼠种植体一般情况,用牙周探针测量大鼠种植体探诊深度(probing depth,PD)和牙龈指数(gingival index,GI);计算机断层扫描(computed tomography,CT)测量大鼠种植体周围骨高度与骨密度;用酶联免疫吸附试验(enzyme linked immunosorbent assay,ELISA)检测大鼠种植体周围牙龈组织中肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)和白细胞介素-6(interleukin-6,IL-6)的含量;蛋白印迹法(Western blotting)检测大鼠种植体周围牙龈组织中TLR4/NF-κB信号通路相关蛋白的表达情况。结果模型组、黄连素低剂量组、黄连素高剂量组、抗生素组及阴性对照组大鼠PD和GI指数逐渐降低,种植体周围骨高度、骨密度逐渐升高,牙龈组织中TNF-α、IL-1β水平逐渐降低,种植体龈沟液中Ⅱ型胶原(collagen-Ⅱ,COL-Ⅱ)和基质金属蛋白酶13(matrix metalloproteinase-13,MMP-13)活性逐渐升高(P<0.05)。模型组、黄连素低剂量组和黄连素高剂量组及阴性对照组,大鼠种植体周围牙龈组织中TLR4、MyD88和p-NF-κB-65蛋白的相对表达量逐渐降低(P<0.05)。结论黄连素对大鼠种植体周围炎有一定治疗作用,其机制可能与抑制TLR4/NF-κB信号通路有关。

三黄益肾胶囊调控NF-κB信号通路减轻糖尿病肾病大鼠炎症反应的机制研究

目的:旨在探究三黄益肾胶囊治疗糖尿病肾病(DN)可能的炎症反应机制。方法:按照随机数字表法将60只大鼠分为正常组、模型组、厄贝沙坦组及三黄益肾低、中、高剂量组,每组10只。除正常组外,其余各组大鼠用高糖高脂饲料联合链脲佐菌素(STZ)注射建立DN模型。正常组和模型组给予生理盐水2 mL灌胃;厄贝沙坦组给予厄贝沙坦11.51 mg/kg灌胃;三黄益肾低、中、高剂量组分别给予三黄益肾胶囊0.41、0.81、1.62 g/kg灌胃。各组大鼠均1次/d,连续给药4周。比较各组大鼠空腹血糖(FBG)、体质量、24 h尿白蛋白、肾功能指标、肾组织病理学变化、肾组织抗氧化相关指标(SOD、GSH-Px活性及MDA水平)、肾组织炎症介质[白细胞介素6(IL-6)、白细胞介素1β(IL-1β)、肿瘤坏死因子α(TNF-α)]、肾组织诱导型一氧化氮合酶(iNOS)、肾组织CD68、CC趋化因子受体2(CCR2)表达、肾组织CC趋化因子配体2(CCL2)、NF-κB P65、p-NF-κB P65、IκB、p-IκB表达。结果:与模型组比较,各三黄益肾胶囊组大鼠体质量高,FBG、血清肌酐(Cr)、尿素氮(BUN)及24 h尿蛋白水平低,肾脏组织病理变化减轻,三肾组织中SOD、GSH-Px活性高,MDA水平低,IL-6、IL-1β、TNF-α水平低,肾组织中iNOS水平低,肾组织CCR2与CD68共定位水平低,CCL2、p-NF-κB P65、p-IκB蛋白表达低。结论:三黄益肾胶囊治疗DN的机制可能与抑制肾组织中NF-κB信号通路激活,减轻肾脏氧化应激及炎症反应有关。

子宫内膜癌组织NF-κB、STAT3蛋白对子宫内膜癌的诊断及预后价值意义分析

目的探讨与分析子宫内膜癌(EC)组织核因子κB(NF-κB)、信号转导与转录激活因子3(STAT3)蛋白对子宫内膜癌的诊断及预后价值意义。方法选择2019年9月—2022年11月石河子大学第一附属医院收治的88例子宫内膜癌患者作为研究对象,取所有患者术中切除的新鲜子宫内膜癌肿瘤组织标本(肿瘤组)和癌旁正常子宫内膜组织(癌旁组),采用免疫组化法检测NF-κB、STAT3蛋白表达阳性率,调查患者的病理特征、随访预后并进行相关性分析。结果肿瘤组NF-κB、STAT3蛋白表达阳性率显著高于癌旁组,差异具有统计学意义(P<0.05)。在88例患者中,不同年龄、临床分期、分化程度、肌层浸润、淋巴结转移患者的NF-κB、STAT3蛋白表达阳性率比较,差异具有统计学意义(P<0.05)。所有患者随访到2023年6月1日,生存患者NF-κB、STAT3蛋白表达阳性率明显低于死亡患者,差异具有统计学意义(P<0.05)。Cox回归分析显示NF-κB、STAT3蛋白表达阳性率为影响预后中位生存时间的重要因素,差异有统计学意义(P<0.05)。结论子宫内膜癌组织多伴随有NF-κB、STAT3蛋白的高表达,其表达水平与患者的临床病理特征和预后生存情况都存在相关性。

术后腹腔粘连形成机制及间充质干细胞外泌体的治疗前景

背景:术后腹腔粘连的形成是一个复杂的过程,预防术后粘连是临床上亟待解决的问题。目的:旨在从细胞及分子水平分析粘连的发生机制,为间充质干细胞外泌体预防和治疗粘连提供理论依据。方法:以“腹腔粘连,盆腔粘连,术后粘连,上皮间充质转化,间充质干细胞,干细胞外泌体,间充质干细胞外泌体”为中文检索词,以“Abdominal adhesion,pelvic adhesion,postoperative adhesion,epithelial mesenchymal transformation,mesenchymal stem cell,stem cell exosomes,mesenchymal stem cell exosomes”为英文检索词,检索PubMed、中国知网和中国生物医学文献数据库,筛选各数据库建库至2023年8月发表的术后腹腔粘连及间充质干细胞外泌体干预研究的相关文章,并进行系统的整理分析,最终纳入54篇文献进行综述。结果与结论:(1)任何腹膜炎症、机械损伤、组织缺血和异物植入等病理因素均可引起腹膜表面的损伤,引起术后腹腔粘连;腹腔粘连的形成过程包括腹膜间皮细胞修复、炎性反应、纤溶系统及凝血途径等过程的相互作用,涉及多种细胞因子及信号通路,包括Wnt/β-catenin通路能诱导纤维化和血管生成,并与转化生长因子β/Smads信号通路相互协同,能刺激成纤维细胞增殖,引起腹膜纤维化;同时,核转录因子kB信号通路上调细胞炎症因子的表达,促进成纤维细胞增生,组织纤维化的过程中发挥关键作用。(2)干细胞的旁分泌功能是目前以再生医学为基础的分子干预腹腔粘连的重要方向,可以参与作用于腹腔粘连中的多种复杂细胞因子及信号通路。(3)相对于传统治疗腹腔粘连的方法,间充质干细胞外泌体具有生物活性、使用安全、无需特殊培养和扩增、更低的免疫原性及较长的稳定性等优势,能通过多种途径引导一种正常的修复和愈合。(4)间充质干细胞外泌体在以往研究中均被证明可以参与调节粘连形成的上述各过程,在临床研究中显示出潜在的应用前景,但需要进一步临床研究以探索适当的间充质干细胞外泌体治疗方案,来解决临床转化的问题。

基于差分结构的地面核磁共振数据噪声压制技术

地面核磁共振(surface nuclear magnetic resonance,SNMR)技术是一种可直接定性定量探测地下水的非侵害式地球物理方法,已广泛应用于资源勘探、地质灾害预警和环境检测等方面。但在实际应用中,复杂的环境噪声导致微弱的SNMR信号常常被淹没,很难获取有效的SNMR信号。针对这一问题,本文提出了一种基于差分结构的SNMR数据噪声压制技术,采用两个接收线圈等距设置在发射线圈上下位置。这种分布可以实时抵消大部分环境噪声以及消除收发线圈耦合影响。理论建模和仿真结果验证了新方法能够有效压制噪声,并可靠获取到早期自由感应衰减(free induction decay,FID)信号。

Observation of intermolecular double-quantum coherence signal dips in nuclear magnetic resonance

The correlated spectroscopy revamped by asymmetric Z-gradient echo detection （CRAZED） sequence is modified to investigate intermolecular double-quantum coherence nuclear magnetic resonance signal dips in highly polarized spin systems. It is found that the occurrence of intermolecular double-quantum coherence signal dips is related to sample geometry, field inhomogeneity and dipolar correlation distance. If the field inhomogeneity is refocused, the signal dip occurs at a fixed position whenever the dipolar correlation distance approaches the sample dimension. However, the position is shifted when the field inhomogeneity exists. Experiments and simulations are performed to validate our theoretic analysis. These signal features may offer a unique way to investigate porous structures and may find applications in biomedicine and material science.

白细胞介素1β调控信号素3A表达诱发椎间盘退变的机制

背景:信号素3A是重要的神经血管生长抑制因子,目前尚不清楚信号素3A是如何参与盘源性腰痛发病的,研究信号素3A在椎间盘退变中的潜在机制可为防治盘源性腰痛提供新的靶点和理论依据。目的:通过激活核因子κB信号通路影响信号素3A的表达,探讨白细胞介素1β诱导大鼠椎间盘退变的机制。方法:采用RT-qPCR检测人未退变与退变髓核组织内的信号素3A mRNA表达。分离培养SD大鼠髓核细胞,传代至第3代时分3组培养:空白对照组常规培养48 h,退变组加入10 ng/mL白细胞介素1β干预48 h,退变+抑制剂组加入5μmol/L核因子κB信号通路特异性抑制剂BAY11-7082干预1 h后加入白细胞介素1β干预48 h。干预结束后,采用CCK-8法检测细胞活力,Annexin V/FITC染色法检测细胞凋亡,RT-qPCR检测细胞基质、血管、神经标志物及信号素3A的mRNA表达,Western blot检测标志蛋白、核因子κB信号通路蛋白p65及p-p65的蛋白表达。结果与结论:①RT-qPCR检测显示,人退变髓核组织内的信号素3A mRNA表达低于未退变髓核组织(P<0.05);②CCK-8检测与Annexin V/FITC染色显示,与空白对照组比较,退变组髓核细胞活力降低、凋亡率增加(P<0.05);与退变组比较,退变+抑制剂组髓核细胞活力升高、凋亡率降低(P<0.05);③RT-qPCR检测显示,与空白对照组比较,退变组Ⅱ型胶原蛋白、聚蛋白多糖、信号素3A的mRNA表达降低(P<0.05),CD31、神经丝蛋白200的mRNA表达升高(P<0.05);与退变组比较,退变+抑制剂组Ⅱ型胶原蛋白、聚蛋白多糖、信号素3A的mRNA表达升高(P<0.05),CD31、神经丝蛋白200的mRNA表达降低(P<0.05);④Western blot检测显示,与空白对照组比较,退变组Ⅱ型胶原蛋白、聚蛋白多糖、信号素3A的蛋白表达降低(P<0.05),CD31、神经丝蛋白200、p65及p-p65的蛋白表达升高(P<0.05);与退变组比较,退变+抑制剂组Ⅱ型胶原蛋白、聚蛋白多糖、信号素3A的蛋白表达升高(P<0.05),CD31、神经丝蛋白200、p65及p-p65的蛋白表达降低(P<0.05);⑤结果表明,白细胞介素1β通过激活核因子κB信号通路抑制信号素3A的表达,同时促进细胞外基质的降解和椎间盘内血管神经的长入,可能为椎间盘退变及相关盘源性腰痛的诱发因素之一。

菟丝子治疗骨关节炎:网络药理学分析及实验验证

背景:菟丝子具有补肝肾、益精髓的功效,而骨关节炎的主要病机为肝肾亏虚,推测菟丝子与骨关节炎之间有一定的联系。目的:基于网络药理学和分子对接的分析手段挖掘骨关节炎和菟丝子之间的潜在联系,对中药本草菟丝子的作用机制进行合理的推测与验证。方法:先在中草药数据库TCMSP中筛选菟丝子的有效活性成分和作用靶点,另在疾病数据库GeneCards、OMIM、TTD中收集骨关节炎的相关基因;取交集后进行一系列分析,并筛选出核心基因;通过对核心基因的富集分析选择菟丝子作用于骨关节炎的通路,通过分子对接验证核心基因的作用,并依此选择合适的有效活性成分进行实验验证。结果与结论:①筛选出11种菟丝子的有效活性成分,菟丝子和骨关节炎有66个交集靶点基因,后续筛选出12个核心基因,包括肿瘤坏死因子、白细胞介素1B、TP53、RACα丝氨酸/苏氨酸蛋白激酶(AKT1)、血管内皮生长因子A、基质金属蛋白酶9、前列腺素过氧合酶2、胱天蛋白酶3、表皮生长因子、过氧化物酶体增生激活受体γ、白细胞介素10、血管细胞黏附因子1;②对核心基因进行富集分析后,选择经典炎症通路核因子κB信号通路进行后续菟丝子缓解骨关节炎炎症的分析验证;根据各活性成分和通路核心基因前列腺素过氧合酶2进行分子对接后得到的结果,选择亲和力最高的芝麻素进行后续细胞实验验证,结果证实了菟丝子的有效成分芝麻素可以通过抑制白细胞介素1β诱导的核因子κB信号通路降低环氧合酶2的表达;③结果表明,菟丝子的活性有效成分芝麻素通过抑制白细胞介素1β诱导的核因子κB信号通路降低环氧合酶2的表达,达到改善骨关节炎炎症的作用,证实了菟丝子在骨关节炎方面的治疗效果。

基于三角函数的核信号类高斯成形算法研究

高斯信号具有高信噪比、抗弹道亏损和易于提取幅度等优点。因此,在核辐射测量系统中,核信号的高斯成形被广泛应用于探测器输出信号的滤波和幅度提取。然而,目前实时高斯成形核脉冲信号仍然具有挑战性。常见的Sallen-Key滤波器和CR-(RC)^(m)滤波器输出的类高斯信号还存在对称性差和下冲等问题。本文提出了一种基于三角函数的双指数信号类高斯脉冲成形算法。该算法以三角函数为基础,通过平移和反转可得到左右对称的类高斯信号(1-cosx),采用Z变换方法推导了该算法的数字递推式。仿真和实测结果表明:在相同达峰时间条件下,相较于正弦函数(sin)脉冲成形,类高斯脉冲成形具有更好的滤波性能,信噪比(SNR)提升了8.95%。同时,类高斯脉冲成形所得能谱的能量分辨率较sin脉冲成形更优。与梯形脉冲成形相比,类高斯脉冲成形具有更好的堆积脉冲分离能力,展现出良好的应用前景。

SR9009联合吲哚丙酸通过核因子κB信号通路减轻C2C12成肌细胞的炎症反应

背景:钟基因Rev-erbα参与调节炎症,但激活Rev-erbα会增加心脑血管疾病风险。为降低相关风险,探索Rev-erbα激动剂SR9009联合其他药物来减轻骨骼肌成肌细胞炎症,奠定治疗炎症相关性骨骼肌萎缩的理论基础。目的:探讨脂多糖刺激C2C12成肌细胞时吲哚丙酸、SR9009与核因子κB信号通路的关系。方法:①1μg/mL脂多糖刺激C2C12成肌细胞,RNA转录组测序结合KEGG通路富集分析信号通路。②CCK-8法检测C2C12成肌细胞活性,筛选吲哚丙酸的最佳给药浓度;然后将细胞分为空白对照组、脂多糖(1μg/mL)组、SR9009(10μmol/L)+脂多糖组、吲哚丙酸(80μmol/L)+脂多糖组、吲哚丙酸+SR9009+脂多糖组,ELISA检测细胞上清液中白细胞介素6水平,RT-qPCR检测白细胞介素6、肿瘤坏死因子α、Toll样受体4、CD14 mRNA表达,Western blot检测NF-κB p65、p-NF-κB p65蛋白表达。③siRNA敲减Rev-erbα,RT-qPCR评估敲减效率,检测白细胞介素6、肿瘤坏死因子αmRNA表达。结果与结论:①与空白对照组比较,脂多糖时间依赖性抑制成肌细胞融合形成肌管,白细胞介素6、肿瘤坏死因子αmRNA表达水平升高,细胞上清液中白细胞介素6水平显著升高;KEGG通路分析支持脂多糖刺激激活核因子κB信号通路。②吲哚丙酸浓度>80μmol/L时抑制C2C12成肌细胞活性;吲哚丙酸和SR9009通过抑制核因子κB信号通路发挥抗炎作用,降低白细胞介素6、肿瘤坏死因子α、Toll样受体4、CD14 mRNA表达水平,p-NF-κB p65/NF-κB p65蛋白表达比值低于脂多糖组。SR9009联合吲哚丙酸显著降低脂多糖诱导的炎症,Toll样受体4、CD14、白细胞介素6和肿瘤坏死因子αmRNA表达水平进一步下调,p-NF-κB p65/NF-κB p65蛋白表达比值显著低于吲哚丙酸+脂多糖组和SR9009+脂多糖组。③Rev-erbα随脂多糖刺激时间依赖性升高;siRNA敲减Rev-erbα效率达58%以上,成功敲减Rev-erbα后添加脂多糖,白细胞介素6和肿瘤坏死因子αmRNA表达较脂多糖组显著上调。④结果说明,Rev-erbα可以作为调节炎症反应的靶点,SR9009靶向激活Rev-erbα联合吲哚丙酸能抑制核因子κB信号通路显著减轻C2C12成肌细胞的炎症反应,联合抗炎效果优于单独干预。