Peripheral interactions between cannabinoid and opioid systems contribute to the antinociceptive effect of crotalphine

Background and Purpose

Crotalphine is an antinociceptive peptide that, despite its opioid-like activity, does not induce some of the characteristic side effects of opioids, and its amino acid sequence has no homology to any known opioid peptide. Here, we evaluated the involvement of the peripheral cannabinoid system in the crotalphine effect and its interaction with the opioid system.

Experimental Approach

Hyperalgesia was evaluated using the rat paw pressure test. Involvement of the cannabinoid system was determined using a selective cannabinoid receptor antagonist. Cannabinoid and opioid receptor activation were evaluated in paw slices by immunofluorescence assays using conformation state-sensitive antibodies. The release of endogenous opioid peptides from skin tissue was measured using a commercial enzyme immunoassay (EIA).

Key Results

Both p.o. (0.008–1.0 μg·kg⁻¹) and intraplantar (0.0006 μg per paw) administration of crotalphine induced antinociception in PGE₂-induced hyperalgesia. Antinociception by p.o. crotalphine (1 μg·kg⁻¹) was blocked by AM630 (50 μg per paw), a CB₂ receptor antagonist, and by antiserum anti-dynorphin A (1 μg per paw). Immunoassay studies confirmed that crotalphine increased the activation of both κ-opioid (51.7%) and CB₂ (28.5%) receptors in paw tissue. The local release of dynorphin A from paw skin was confirmed by in vitro EIA and blocked by AM630.

Conclusions and Implications

Crotalphine-induced antinociception involves peripheral CB₂ cannabinoid receptors and local release of dynorphin A, which is dependent on CB₂ receptor activation. These results enhance our understanding of the mechanisms involved in the peripheral effect of crotalphine, as well as the interaction between the opioid and cannabinoid systems.     

HERV-K Gag RNA and Protein Levels Are Elevated in Malignant Regions of the Prostate in Males with Prostate Cancer

Heightened expression of human endogenous retrovirus (HERV) sequences has been associated with a range of malignancies, including prostate cancer, suggesting that they may serve as useful diagnostic or prognostic cancer biomarkers. We analysed the expression of HERV-K (Gag and Env/Np9 regions), HERV-E 4.1 (Pol and Env regions), HERV-H (Pol) and HERV-W (Gag) sequences in prostate cancer cells lines and normal prostate epithelial cells using qRT-PCR. HERV expression was also analysed in matched malignant and benign prostate tissue samples from men with prostate cancer (n = 27, median age 65.2 years (range 47–70)) and compared to prostate cancer-free male controls (n = 11). Prostate cancer epithelial cell lines exhibited a signature of HERV RNA overexpression, with all HERVs analysed, except HERV-E Pol, showing heightened expression in at least two, but more commonly all, cell lines analysed. Analysis of primary prostate material indicated increased expression of HERV-E Pol but decreased expression of HERV-E Env in both malignant and benign regions of the prostate in men with prostate cancer as compared to those without. Expression of HERV-K Gag was significantly higher in malignant regions of the prostate in men with prostate cancer as compared to matched benign regions and prostate cancer-free men (p < 0.001 for both), with 85.2% of prostate cancers donors showing malignancy-associated upregulation of HERV-K Gag RNA. HERV-K Gag protein was detected in 12/18 (66.7%) malignant tissues using immunohistochemistry, but only 1/18 (5.6%) benign tissue sections. Heightened expression of HERV-K Gag RNA and protein appears to be a sensitive and specific biomarker of prostate malignancy in this cohort of men with prostate carcinoma, supporting its potential utility as a non-invasive, adjunct clinical biomarker.     

动物内源性多肽CGA—N46抗菌谱及对动物细胞的作用

目的研究抗真菌肽CGA-N46的抗菌谱及对不同动物细胞的作用效果。方法采用微量稀释法测定CGA-N46对14种常见病原真菌的抗菌活性;采用分光光度法检测CGA-N46对红细胞的溶解作用,采用MTT法测定CGAN46对鸡胚成纤维细胞的毒性作用及对癌细胞的抑制作用。结果CGA-N46对光滑念珠菌、近平滑念珠菌、克柔念珠菌、热带念珠菌、白念珠菌具有抑菌活性,其MIC分别为4．0、4．0、0．5、1．0、1．0mg／ml;最小抑菌浓度的CGA-N46无溶血作用,对鸡胚成纤维细胞无毒性,但对肺癌A549细胞有抑制作用,72h最大抑制率为60．53％。结论CGA-N46多肽具有抗念珠菌作用,且具有抗癌潜力,而对正常细胞安全、无毒性。     

Inhibition of porcine endogenous retrovirus in PK15 cell line by efficient multitargeting RNA interference

To effectively suppress porcine endogenous retroviruses (PERV)s, RNAi technique was utilized. RNAi is the up‐to‐date skill for gene knockdown which simultaneously multitargets both gag and pol genes critical for replication of PERVs. Previously, two of the most effective siRNAs (gag2, pol2) were found to reduce the expression of PERVs. Concurrent treatment of these two siRNAs (gag2+pol2) showed knockdown efficiency of up to 88% compared to negative control. However, despite the high initial knockdown efficiency 48 h after transfection caused by siRNA, it may only be a transient effect of suppressing PERVs. The multitargeting vector was designed, containing both gag and pol genes and making use of POL II miR Expression Vector, which allowed for persistent and multiple targeting. This is the latest shRNA system technique expressing and targeting like miRNA. Through antibiotics resistance characteristics utilizing this vector, miRNA‐transfected PK15 cells (gag2‐pol2) were selected during 10 days. An 88.1% reduction in the level of mRNA expression was found. In addition, we performed RT‐activity analysis and fluorescence in situ hybridization assay, and it demonstrated the highest knockdown efficiency in multitargeting (gag2+pol2) miRNA group. Therefore, according to the results above, gene knockdown system (siRNA and shRNA) through multitargeting strategy could effectively inhibit PERVs.     

无神经损伤的脊柱胸腰段爆裂型骨折治疗的临床观察

目的观察手术治疗与保守治疗无神经损伤的脊柱腰段爆裂性骨折的临床疗效,分析两种治疗方法的临床应用价值。方法选取2011年2月～2013年2月期间在我院住院治疗的脊柱腰段爆裂性骨折患者90例作为研究对象。根据治疗方法分为实验组和对照组,实验组患者采取手术治疗,对照组患者采取保守治疗,对比两组的临床疗效。结果实验组患者的临床有效率为81．82％,对照组患者的临床有效率为82．61％,两组临床有效率比较差异无统计学意义（P〉0．05）。两组患者治疗前的椎体前高、Cobb角以及椎管占位程度比较差异无统计学意义（P〉0．05）。两组患者治疗后的椎体前高、Cobb角以及椎管占位程度比较差异具有统计学意义（P〈0．05）。结论手术治疗与保守治疗无神经损伤的脊柱腰段爆裂性骨折的临床疗效无明显差异,但手术治疗对患者的椎体前、Cobb角以及椎管占位程度等指标改善修复效果更显著,有助于患者的恢复。     

电刺激联合神经营养素3可促进脊髓损伤大鼠内源性神经干细胞的增殖和分化

文题释义： 神经营养素3：是神经生长因子基因家族的成员,可促进多种中枢和外周神经元的存活和分化,调节神经元突触活动,并对神经系统发育和成熟起重要作用。神经营养素3在损伤条件下对神经元具有保护作用,因而在治疗神经系统疾病和神经损伤中有临床应用前景。 内源性神经干细胞：正常机体中,神经干细胞一般处于静息状态,在特定的生理或病理刺激下被激活,其中侧脑室外侧壁的室下带和海马齿状回的颗粒下带是产生神经干细胞最为活跃的区域,神经系统损伤后,在多种细胞因子、调控基因的调节下发生增殖、迁移和分化等。 背景：由于外源性神经干细胞的获取有限,且容易产生免疫排斥以及伦理问题等严重制约其向临床转化,因此如何激活内源性神经干细胞并促进其生长增殖、分化,成为近期科研工作者究的热点。 目的：探讨电刺激联合神经营养素3对大鼠脊髓损伤后内源性神经干细胞增殖及向神经元分化的作用。 方法：将96只SD大鼠随机分为假手术组、脊髓损伤组、电刺激组、电刺激+神经营养素3组,每组24只。假手术组仅暴露脊髓,其他3组大鼠应用改良Allen法建立脊髓损伤模型,造模后给予相应措施进行干预。造模后7,14,21,28 d时,以BBB评分评价大鼠后肢运动功能,电生理学检查运动诱发电位潜伏期;造模后28 d取材,进行苏木精-伊红染色观察脊髓病理变化,免疫组化染色观察内源性神经干细胞的增殖和分化情况。实验方案经兰州大学第二医院医学伦理委员会批准。 结果与结论：①与假手术组相比,脊髓损伤组大鼠的BBB评分明显降低(P < 0.01),脊髓组织可见大量炎症细胞浸润,并存在多个空洞;与脊髓损伤组相比,电刺激组、电刺激+神经营养素3组大鼠后肢功能开始逐渐恢复,电刺激+神经营养素3组BBB评分明显高于电刺激组(P < 0.05),上述病理损伤变化明显改善;②脊髓损伤组7,14 d及电刺激组大鼠7 d时双后肢运动诱发电位潜伏期均未测出,电刺激组、电刺激+神经营养素3组21,28 d时运动诱发电位潜伏期较模型组缩短(P < 0.05),电刺激+神经营养素3组潜伏期缩短更显著    (P < 0.05);③BrdU和Nestin阳性细胞数、微管相关蛋白2的表达：电刺激+神经营养素3组>电刺激组>脊髓损伤组;胶质纤维酸性蛋白的表达：脊髓损伤组>电刺激组>电刺激+神经营养素3组。结果表明脊髓损伤大鼠经电刺激及神经营养素3干预后,促进内源性神经干细胞增殖和向神经元分化,病理损伤明显减轻,后肢运动功能显著改善。 ORCID: 0000-0002-6353-8874(张培根) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

血红素氧合酶-1/一氧化碳系统的变化对兔动脉粥样硬化进程的影响

目的研究食饵性动脉粥样硬化(AS)形成中,主动脉壁内血红素氧合酶-1(HO-1)活性及一氧化碳(CO)生成的变化及对AS进程的影响,以探讨HO-1/CO系统在AS进程中的作用。方法32只新西兰大白兔,随机均分为4组。对照组:喂饲普通饲料;胆固醇组:喂饲含1.5%胆固醇饲料;卟啉锌组及血红素组:在予以高胆固醇饮食的同时,分别经腹腔注射氯化血红素(15mg·kg-1·d-1)或锌原卟啉-9(45μmol·kg-1·d-1),共12周。采血测定血脂、血清总胆红素(TBil)水平;取主动脉,测定CO生成量及HO-1活性,采用油红O染色及图像分析软件检测主动脉斑块面积。结果与对照组比较,胆固醇组主动脉CO生成量及HO-1活性显著增高(P均<0·01),实验结束时主动脉斑块面积达54·00%±4·16%;锌原卟啉-9显著降低了主动脉CO生成量及HO-1活性(P均<0·01),主动脉斑块面积达61·13%±3·50%;与胆固醇组比较,氯化血红素显著增高了血清TBil水平、主动脉CO生成量及HO-1活性(P均<0·01),主动脉斑块面积仅17·88%±3·01%(P<0·05)。结论HO-1/CO系统具有延缓AS的作用,HO-1活性增高可能是HO-1/CO系统发挥抗AS作用的基础。