小分子多肽与人类免疫缺陷病毒感染的关系

目的 探讨人类免疫缺陷病毒（HIV-1）感染者体内可能存在的保护性中和抗体。方法 方法 应用ELISA等方法检测正常对照人群，HIV-1感染无症状组，长期生存组和艾滋病患者体内小分子多肽抗体（抗-R7V）分布状况。结果 抗R7V在无症状组和长期存活组中检出率较高，而在进展者和艾滋病患者中存在较低，并发现抗-R7V能中和HIVRNA。结论 抗-R7V的存在与病情进展有密切关系。能够使HIV感染者长期处于无进展状态，延缓或者阻止感染者发展为艾滋病。     

Content of Dynorphins and k-Opioid Receptors in Distinct Brain Regions of C57BL/6 and DBA/2 Mice

Differences in the activity of various components of the endogenous opioid system under basal conditions and after ethanol exposure have been reported between strains and lines of animals showing either high or low ethanol consumption. The objective of the present studies was to investigate the presence of differences in (a) the density of k-opioid binding sites, (b) the content of prodynorphin mRNA, and (c) the content of dynorphin peptides in distinct brain regions between the C57BL/6 (ethanol-preferring) and the DBA/2 (ethanol-avoiding) mice. Results indicated that the C57BL/6 mice have a higher content of k-opioid binding sites and dynorphin A1-13 in the amygdala, and dynorphin A 1–8 in the ventral tegmental area, whereas the DBA/2 mice presented a significantly higher content of k-opioid binding sites, prodynorphin mRNA, as well as dynorphin A 1–13 and dynorphin A 1–8 peptides in the nucleus accumbens and septum. In addition, the DBA/2 mice presented a higher content of k-opioid receptors in the periaqueductal gray and dynorphin A1-13 and dynorphin A 1–8 in the caudate putamen. Because enhanced stimulation of the k-opioid receptors at the level of the nucleus accumbens has been associated with decreased dopamine release and aversive states, the higher content of k-opioid receptors, prodynorphin mRNA, and dynorphin peptides (the endogenous ligand of k-binding sites) in regions of the limbic system of the DBA/2 mice may play an important role in determining their low alcohol consumption.     

B-type Natriuretic Peptide: Perioperative Patterns in Congenital Heart Disease

Objective. B-type natriuretic peptide (BNP) has diagnostic, prognostic, and therapeutic roles in adults with heart failure. BNP levels in children undergoing surgical repair of congenital heart disease (CHD) were characterized broadly, and distinguishable subgroup patterns delineated. Design. Prospective, blinded, observational case series. Setting. Academic, tertiary care, free-standing pediatric hospital. Patients. Children with CHD; controls without cardiopulmonary disease. Interventions. None. Measurements. Preoperative cardiac medications/doses, CHD lesion types, perioperative BNP levels, intraoperative variables (lengths of surgery, bypass, cross-clamp), postoperative outcomes (lengths of ventilation, hospitalization, open chest; averages of inotropic support, central venous pressure, perfusion, urine output; death, low cardiac output syndrome (LCOS), cardiac arrest; readmission; and discharge medications). Results. Median BNP levels for 102 neonatal and non-neonatal controls were 27 and 7 pg/mL, respectively. Serial BNP measures from 105 patients undergoing CHD repair demonstrated a median postoperative peak at 12 hours. The median and interquartile postoperative 24-hour average BNP levels for neonates were 1506 (782–3784) pg/mL vs. 286 (169–578) pg/mL for non-neonates (P < 0.001). Postoperative BNP correlated with inotropic requirement, durations of open chest, ventilation, intensive care unit stay, and hospitalization (r = 0.33–0.65, all P < 0.001). Compared with biventricular CHD, Fontan palliations demonstrated lower postoperative BNP (median 150 vs. 306 pg/mL, P < 0.001), a 3-fold higher incidence of LCOS (P < 0.01), and longer length of hospitalization (median 6.0 vs. 4.5 days, P= 0.01). Conclusions. Perioperative BNP correlates to severity of illness and lengths of therapy in the CHD population, overall. Substantial variation in BNP across time as well as within and between CHD lesions limits its practical utility as an isolated point-of-care measure. BNP commonly peaks 6–12 hours postoperatively, but the timing and magnitude of BNP elevation demonstrates notable age-dependency, peaking earlier and rising an order of magnitude higher in neonates. In spite of higher clinical acuity, non-neonatal univentricular CHD paradoxically demonstrates lower BNP levels compared with biventricular physiologies.     

PrP106-126多肽抑制14-3-3β蛋白二聚体形成的研究

目的 探讨PrP蛋白和PrP106-126多肽对14-3-3蛋白二聚体形成的影响 方法 将重组表达纯化的0.25 μg、0.5 μg和1μg PrP蛋白、人工合成的PrP06-126肽分别与重组的14-3-3β共孵育,分别通过非变性聚丙烯酰胺凝胶的Western Blott检测PrP蛋白和PrP106-126肽对14-3-3β二聚体和多聚体的形成影响.将不同浓度的PrP与250 μmol/L的PrP106-126肽和14-3-3蛋白共孵育,检测PrP蛋白对PrP106-126肽对14-3-3β二聚体和多聚体的形成影响.随后,将200μmol/L、100 μmol/L、50 μmol/L的PrP106-126多肽分别作用于HeLa细胞8h后,检测细胞内的14-3-3二聚体形成.结果 PrP蛋白与14-3-3蛋白共孵育后,14-3-3二聚体和多聚体的信号随着PrP浓度的增加明显增强；PrP106-126多肽共孵育时,14-3-3二聚体和多聚体的信号随着PrP浓度的增加而减弱；不同浓度的PrP蛋白可以拮抗PrP106-126多肽对14-3-3β二聚体的形成.而且PrP106-126多肽可以干扰HeLa细胞中的二聚体形成.结论 PrP蛋白促进14-3-3二聚体的形成,而PrP106-126多肽干扰二聚体的形成,且PrP蛋白具有拮抗PrP106-126肽干扰14-3-3二聚体形成的作用.     

Cell-selective intracellular drug delivery using doxorubicin and α-helical peptides conjugated to gold nanoparticles

Cell penetrating peptides (CPPs), which can enter a cell through the cell membrane, have potential research applications in the fields of drug delivery, gene therapy, and cancer therapy. However, CPPs are associated with problems such as low cell selectivity, low cell penetrating activity, and cell toxicity. To overcome the disadvantages of CPPs, we constructed a drug delivery system by developing 25 nm gold nanospheres (GNSs) conjugated to four α-helical CPPs from our peptide library. We examined the applicability of this cell-selective drug delivery system by evaluating its cell-penetrating and cell death activities and comparing them with those activities of the TAT peptide. Using the 25 nm GNS, we obtained higher cell death induction activity by the anti-cancer drug doxorubicin compared with our previous study using a 41 nm GNS. After entering the cell, the peptide-conjugated 25 nm GNS accumulated around the cell nucleus. High cell selectivity by α-helical CPP sequences was also demonstrated. Our results indicate that these α-helical peptide and 25 nm GNS conjugates are useful elements in an efficient cell-selective drug delivery system.     

应用MALDI-TOF-MS检测原发性肝癌骨转移患者血清的多肽差异谱

目的:应用基质辅助激光解析电离飞行时间质谱(matrix-assisted laser desorption ionization-time of flight mass spectrometry,MALDI-TOF-MS)系统分析原发性肝细胞癌(hepatocellular carcinoma,HCC)骨转移患者血清多肽差异谱,寻找具有潜在诊断意义的血清分子标志物.方法:收集50例HCC骨转移患者和50例HCC未骨转移患者的血清,分成训练组(76例)和验证组(24例).所有样本分别经ClinProt磁珠纯化、MALDI-TOF-MS检测及ClinProTools软件进行血清多肽差异谱分析.应用液相色谱质谱联用的方法对差异多肽进行序列鉴定.应用径向基神经网络(radial basis function neural network,RBFNN)算法建立诊断模型,并对诊断模型进行单盲法实验验证.结果:HCC骨转移患者中,共获得10条差异有统计学意义[P (Wilcoxon-test)＜0.001]的多肽峰,并成功鉴定了其中7条肽段(质荷比分别为1 780.7、1 866.5、2 131.6、2 880.4、1 532.4、2 489.8和2 234.3)的氨基酸序列,这些肽段的来源蛋白分别为甲胎蛋白(alpha-fetoprotein)、凝血酶原(prothrombin)、丝甘蛋白聚糖(serglycin)、交联-α-胰蛋白酶抑制物H4重链异构体2(isoform 2 of inter-alpha-trypsin inhibitor heavy chain H4)、自噬相关蛋白16-2异构体1(isoform 1 of autophagy-related protein 16-2)、转甲状腺素蛋白(transthyretin)和纤维蛋白β链(fibrinogen beta chain).选取2组间统计学差异最显著的6条多肽峰(质荷比分别为1 535.4、1 780.7、1 866.5、2 131.6、2 880.4和2 901.9)建立的诊断模型的识别率为89.47％,预测率为82.89％;单盲法验证模型的灵敏度为83％,特异度为92％.结论:筛选获得的差异血清多肽可能成为潜在的诊断HCC骨转移的分子标志物.     

鸡蛋膜活性肽在食管癌患者放化疗期的临床观察

目的 了解鸡蛋膜活性肽对食管癌患者放化疗期间的营养免疫效应.方法 选取2019年2月至10月淮安市第一人民医院和淮安市肿瘤医院肿瘤内科、放疗科患者116例,随机分为常规营养治疗组(TNSG组)和肽强化支持组(PNSG组),每组58例.PNSG组采用鸡蛋膜活性肽强化制剂与TNSG组采用能全素进行口服营养补充.两组患者均在...     

多肽探针在肿瘤成像中的研究进展

肿瘤的精准成像在识别肿瘤位置和分期以及确定合适的治疗方法方面发挥着重要作用。多肽是在成像方面具有前途的工具,已证明相应的受体在肿瘤细胞中过表达,通过与受体特异性结合导致显像剂在肿瘤细胞内成像。此外,由于多肽具有分子量小、免疫原性低、亲和力和特异性高等众多优点使其在肿瘤诊断和治疗中受到越来越多的关注,一些基于多肽的成像探针和治疗剂已成功进入临床试验。本文就多肽探针在肿瘤成像中的研究进展进行综述。     

肾上腺髓质素前体肽内不同片段间的相互作用

肾上腺髓质素(adrenomedullin,ADM)是1993年由Kitamura等[1]发现的一种心血管活性肽.ADM除具有强大的舒张血管、降低血压、抑制血管平滑肌细胞(vascular smooth muscle cells,VSMC)迁移、增殖作用外,还有利钠、利尿和心脏保护等作用,在维持循环稳态和心血管疾病中具有重要意义[1].随后人们发现ADM前体(preproADM,185个氨基酸残基)在体内经内源性肽酶降解后产生的另外3个片段也具有生物学效应:肾上腺髓质素原N末端20肽(preproADM22-41,proADM N terminal20 peptide,PAMP)具有弱的舒张血管、降低血压作用[2];preproADM153-185具有升高血压、促进VSMC增殖的作用[3];preproADM45-92亦具有弱的舒张血管、轻度降低血压的作用[3,4 ].     

Labeling and distribution of linear peptides identified using in vivo phage display selection for tumors

To develop targeting molecules to be used for vascular targeting of short half-lived α-emitters for radioimmunotherapy, linear peptide phage display libraries were selected in vivo for binding to IC-12 rat tracheal tumors growing in severe combined immune deficient mice. After three rounds of selection, 15 phage clones were analyzed for DNA sequence, and the deduced translation products of cDNA inserts were compared. Three consensus sequences were chosen from three separate experimental selection series and peptides of these sequences with added -gly-gly-tyr were obtained. Peptides were radiolabeled on tyrosine with ¹²⁵I and the biodistribution in tumor-bearing mice was determined. The radioiodinated peptides were stable in vitro and when injected in tumor-bearing mice 3.0 %ID/g accumulated in the tumor; however, much of the ¹²⁵I was found in the gastrointestinal tract and thyroid, indicative of dehalogenation of the labeled peptide. Radiolabeling peptide 2 with N-succinimidyl-3-¹²⁵I-iodobenzoate resulted in faster excretion, which in turn resulted in lower levels in tumor and other organs, especially thyroid and gastrointestinal tract. Peptide 2 was derivatized with the bifunctional isothiocyanates of cyclohexyl-B diethylenetriaminepentaacetic acid (DTPA) or CHX-A″ DTPA by direct conjugation or with a hydroxylamine derivative of 1B4M-DTPA (2-(p-[O-(carboxamylmethyl)hydroxylamine]benzyl)-6-methyl-diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid ) coupled at the N-terminus. The primary molecular species in the conjugated products were shown by mass spectrometry to have one DTPA per peptide. Peptide chelate conjugates were radiolabeled with ²¹³Bi and the products tested for biodistribution in tumor-bearing mice. The data show that chelation of ²¹³Bi to peptides was accomplished by both the direct method of DTPA attachment and by the method using the linker at the N-terminus. Only small amounts of peptide accumulated at tumor sites. We conclude that phage display is a powerful tool to select peptides with restricted binding specificity; however, the peptides isolated to date do not bind with high retention to tumor sites in vivo.