Variability within the human iNOS gene and Achilles tendon injuries: Evidence for a heterozygous advantage effect

ObjectivesThe aim of this case control genetic association study was to explore whether two variants within the inducible nitric oxide synthase (iNOS) gene, rs2779249 (C/A) and rs2248814 (A/G), influenced the risk of Achilles tendinopathy in a British population.DesignCandidate gene, case control association study.MethodWe recruited 145 individuals diagnosed with Achilles tendon pathology and 132 asymptomatic controls. All participants were genotyped for the iNOS variants using qPCR and significant associations were discovered using a combination of Chi squared and ANOVA type analysis.ResultsThe CA genotype of the iNOS rs2779249 variant was protective and conformed to a heterozygous advantage model of inheritance as it was overrepresented in the control participants (p = 0.009). In sex specific analysis the protective association persisted in male participants (p = 0.016) but not in females. Unlike the rs2779249 variant, the rs2248814 variant was not associated with Achilles tendinopathy or Achilles tendon rupture.ConclusionThe rs2779249 CA genotype within the human iNOS gene appears to protect individuals from Achilles tendinopathy. This study further supports a genetic contribution to modifying the risk of Achilles tendon problems. The study also infers an important role for nitric oxide in tendon healing and/or degradation.     

Tangeretin ameliorates erectile and testicular dysfunction in a rat model of hypertension

Tangeretin is a polymethoxyflavone concentrated in citrus peels and has several biological activities. This study examined whether tangeretin improved reproductive dysfunction in N^ω-nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced hypertensive rats. Male Sprague-Dawley rats received L-NAME to induce hypertension and reproductive dysfunction for 5 w and were treated with tangeretin (15 or 30 mg/kg) or sildenafil citrate (10 mg/kg) for the final two weeks. Mean arterial pressure (MAP), intracavernosal pressure (ICP) response to cavernous nerve stimulation, endothelial nitric oxide synthase (eNOS), Angiotensin II receptor type 1 (AT₁R) and gp91^phox protein expressions and malondialdehyde (MDA) level in penile tissues were measured. Sperm concentrations and motility, seminiferous tubule morphology, serum testosterone, testicular eNOS and steroidogenic acute regulatory protein (StAR) expression were evaluated. Aortic superoxide generation, plasma and testicular MDA and plasma nitrate/nitrite levels were determined. Tangeretin reduced blood pressure and increased the maximum ICP/MAP associated with suppression of AT₁R/gp91phox and upregulation of eNOS expression in hypertensive rats (P < 0.05). Furthermore, improvement of sperm quality relevant to increased testicular eNOS and StAR expression was found in tangeretin treated rats (P < 0.05). Changes in seminiferous tubule morphology in hypertensive rats were recovered by tangeretin (P < 0.05). It increased testosterone levels and reduced oxidative stress biomarkers and raised plasma nitrate/nitrite levels in L-NAME rats (P < 0.05). In conclusion, tangeretin improved maximum ICP/MAP and testicular dysfunction and morphology in rats treated with L-NAME. The molecular mechanisms are mediated by modulations of penile eNOS and AT₁R/gp91^phox expressions and testicular eNOS and StAR expression.     

Nitric oxide producing coating mimicking endothelium function for multifunctional vascular stents

The continuous release of nitric oxide (NO) by the native endothelium of blood vessels plays a substantial role in the cardiovascular physiology, as it influences important pathways of cardiovascular homeostasis, inhibits vascular smooth muscle cell (VSMC) proliferation, inhibits platelet activation and aggregation, and prevents atherosclerosis. In this study, a NO-catalytic bioactive coating that mimics this endothelium functionality was presented as a hemocompatible coating with potential to improve the biocompatibility of vascular stents. The NO-catalytic bioactive coating was obtained by covalent conjugation of 3,3-diselenodipropionic acid (SeDPA) with glutathione peroxidase (GPx)-like catalytic activity to generate NO from S-nitrosothiols (RSNOs) via specific catalytic reaction. The SeDPA was immobilized to an amine bearing plasma polymerized allylamine (PPAam) surface (SeDPA-PPAam). It showed long-term and continuous ability to catalytically decompose endogenous RSNO and generate NO. The generated NO remarkably increased the cGMP synthesis both in platelets and human umbilical artery smooth muscle cells (HUASMCs). The surface exhibited a remarkable suppression of collagen-induced platelet activation and aggregation. It suppressed the adhesion, proliferation and migration of HUASMCs. Additionally, it was found that the NO catalytic surface significantly enhanced human umbilical vein endothelial cell (HUVEC) adhesion, proliferation and migration. The in vivo results indicated that the NO catalytic surface created a favorable microenvironment of competitive growth of HUVECs over HUASMCs for promoting re-endothelialization and reducing restenosis of stents in vivo.     

口服硝酸盐对大鼠背部随意皮瓣的保护作用及机制探讨

目的 探讨口服硝酸盐对大鼠背部随意皮瓣的影响,以硝酸盐-亚硝酸盐-NO通路为切入点,探讨其可能的机制。方法 将24只雄性Wistar大鼠随机分为硝酸盐组、氯化钠组和对照组,每组8只。采用改良大鼠背部随意皮瓣制作方法造模。硝酸盐干预组在术前7 d及术后每天口服0.5 mmol/L硝酸钠,氯化钠组每天口服等量氯化钠,对照组每天口服蒸馏水。术后第7天,检测各组皮瓣的存活情况,大鼠血清中硝酸盐、亚硝酸盐、肿瘤坏死因子（tumor necrosis factor alpha,TNF-a）和白介素6（interleukin-6,IL-6）水平,以及皮瓣组织中超氧化物歧化酶（superoxide dismutase,SOD）和丙二醛（malondialdehyde,MDA）水平。采用SPSS 20.0软件包对数据进行t检验。结果 硝酸盐组皮瓣的存活面积显著高于对照组（P<0.05）。H-E染色显示,硝酸盐明显减轻了皮瓣的组织学损伤。硝酸钠显著增加了血清中硝酸盐和亚硝酸盐水平（P<0.05）,并显著下调血清中TNF-a和IL-6水平（P<0.05）。此外,硝酸盐组皮瓣组织内MDA表达显著减少（P<0.05）,SOD表达显著增加（P<0.05）。结论 口服硝酸盐可通过调控皮瓣的氧化应激和炎症反应保护皮瓣。     

冠心Ⅲ号对缺血性心肌病氧化及纤维化指标的影响

目的:探讨冠心Ⅲ号对缺血性心肌病机体氧化应激及心肌组织纤维化的影响。方法:选取2017年11月至2019年5月广州中医药大学深圳医院收治的ICM患者100例作为研究对象,按照住院号单双分为对照组和观察组,每组50例。对照组常规西医治疗,观察组在对照组基础上加用冠心Ⅲ号治疗,均治疗4周，观察治疗前后NO、SOD、BNP和心肌纤维化指标变化。结果:1)2组患者治疗4周后ET、CRP、BNP、LVEDd、、透明质酸(HA)、Ⅲ型前胶原(PCⅢ)、层粘连蛋白(LN)较治疗前比较均显著降低，NO、SOD、LVEF、△FS、E/A值及SV较治疗前均显著升高,组内比较差异有统计学意义(P<0.01),且观察组显著优于对照组(P<0.01)；2)治疗前后2组全血高切、全血中切、全血低切、血浆黏度、红细胞压积、纤维蛋白原差异无统计学意义(P>0.05)；3)对照组不良反应率合计12%,观察组为8%,比较差异无统计学意义(P>0.05)。结论:冠心Ⅲ号可通过提高NO、SOD,降低BNP和心肌纤维化,促进血液循环,从而改善心功能,防治ICM。     

Nitric oxide donors offer protection to RBC from storage lesion

BackgroundRed blood cell (RBC), which is the most commonly transfused blood component, due to its ability to save a life in absence of any other blood components, can be stored up to maximum 6 weeks by following standard preservation procedure. During storage, RBC undergoes various biophysical and biochemical changes (commonly known as storage lesion) for which blood transfusion with “old RBC” shows a lot of clinical problems especially relevant to critically ill patients. Recent research on S-nitrosylation of haemoglobin to improve oxygen delivery of banked blood revealed the important role of nitric oxide (NO) in protecting storage lesion.Materials and methodsIn the present study, we used various “NO donating” chemicals with different NO release dynamics and chemistries in RBC storage cocktails to test the effects of NO on storage lesion. Changes in different storage markers were evaluated after 7 days storage of pre-treated RBC.ResultsAll the NO donors have shown protection against hemolysis. However, S-nitroso glutathione (GSNO) ranks first in shielding RBCs from storage lesion and additionally, it helps in elevating the value of 2, 3-di phosphoglycerate (2, 3-DPG), improving the RBC membrane fluidity and decreasing the adhesion towards endothelial monolayer.DiscussionPresent study reveals that NO released from NO donors confers protection against storage lesions of the RBC. Further, the study confirms that pre-treatment with GSNO, a NO donor and a nitrosylating agent, ensures the best protection to RBC during low temperature storage, when compared to other NO donor treatments.     

Different profiles of circulating arginase 2 in subtypes of preeclampsia pregnant women

Background and aimsPreeclampsia (PE) is a gestational hypertensive disease responsible for high maternal and fetal morbidity and mortality. The increase in blood pressure is associated with a decrease in the bioavailability of nitric oxide (NO). Arginase interferes with NO production consuming L-arginine, a substrate required by endothelial NO synthase to NO formation. No previous study has quantified the circulating levels of the two arginase isoforms (arginase 1 and arginase 2) in the plasma of pregnant women with PE. Therefore, our objective is to evaluate these plasma levels in healthy pregnant women and PE with or without severe features and who respond or not to antihypertensive therapy.MethodsWe compared 29 healthy pregnant women with 56 pregnant women with PE, who were also divided into with severe features (n = 24) or without severe features (n = 32) and into responsive (n = 29) or nonresponsive to antihypertensive therapy (n = 27). We quantified the plasmatic expression of arginase 1 and arginase 2 by ELISA kits.ResultsWhile similar levels of arginase 1 were found among groups, lower arginase 2 plasma levels were found in PE without severe features and responsive to antihypertensive drugs when compared to healthy pregnant women. There was no difference between arginase 2 levels in PE with severe features and nonresponsive group when compared to healthy pregnant women.ConclusionThis shows different circulation profiles of arginase 2 among groups, suggesting the existence of mechanisms of arginase 2 modulation in pregnant women with PE associated with the severity of the disease and responsiveness to antihypertensive treatment.     

Single-dose combination nanovaccine induces both rapid and durable humoral immunity and toxin neutralizing antibody responses against Bacillus anthracis

Bacillus anthracis, the causative agent of anthrax, continues to be a prominent biological warfare and bioterrorism threat. Vaccination is likely to remain the most effective and user-friendly public health measure to counter this threat in the foreseeable future. The commercially available AVA BioThrax vaccine has a number of shortcomings where improvement would lead to a more practical and effective vaccine for use in the case of an exposure event. Identification of more effective adjuvants and novel delivery platforms is necessary to improve not only the effectiveness of the anthrax vaccine, but also enhance its shelf stability and ease-of-use. Polyanhydride particles have proven to be an effective platform at adjuvanting the vaccine-associated adaptive immune response as well as enhancing stability of encapsulated antigens. Another class of adjuvants, the STING pathway-targeting cyclic dinucleotides, have proven to be uniquely effective at inducing a beneficial inflammatory response that leads to the rapid induction of high titer antibodies post-vaccination capable of providing protection against bacterial pathogens. In this work, we evaluate the individual contributions of cyclic di-GMP (CDG), polyanhydride nanoparticles, and a combination thereof towards inducing neutralizing antibody (nAb) against the secreted protective antigen (PA) from B. anthracis. Our results show that the combination nanovaccine elicited rapid, high titer, and neutralizing IgG anti-PA antibody following single dose immunization that persisted for at least 108 DPI.     

吸入一氧化氮对急性肺损伤大鼠内源性一氧化氮及纤溶酶原激活物抑制剂-1表达的影响及其相关研究

目的 探讨早期吸入一氧化氮(NO)对急性肺损伤大鼠纤溶酶原激活物抑制剂-1(PAI-1)mRNA和蛋白表达的影响及其意义;观察吸入NO后急性肺损伤大鼠诱生性NO合酶(iNOS)和内源性NO的变化及其与PAI-1表达的关系.方法 采用内毒素(LPS)二次打击方法建立4～5周SD大鼠急性肺损伤模型.对照组和LPS组分别随机给予吸入空气(A)、20×10-6 NO,干预24 h.应用荧光实时定量PCR方法测定大鼠肺组织PAI-1 mRNA水平,免疫组织化学测定2组大鼠肺组织PAI-1蛋白的表达水平,并测定肺组织iNOS活性和NO水平;同时行肺组织病理评分和纤维素染色.结果 造模后气体干预24 h时肺组织PAI-1 mRNA和蛋白表达在NO干预的LPS-NO组较LPS-A组显著降低(4.94 ±0.52比5.56±0.27;1.31 ±0.40比1.69 ±0.16,P均＜0.05).同时NO干预后LPS-NO组iNOS活性和肺组织NO水平均显著低于LPS-A组[(0.84±0.36)U/mg prot比(2.30±0.25) U/mg prot;(1.90±0.84) μmol/g prot比(3.38±0.73) μmol/g prot,P均＜0.05).iNOS活性与PAI-1 mRNA和蛋白表达呈正相关(r=0.481,P=0.005;r =0.667,P=0.000);肺组织NO水平与PAI-1 mRNA和蛋白表达呈正相关(r=0.532,P=0.002;r =0.784,P=0.000).肺病理评分在干预24 h时,LPS-NO组较LPS-A组下降,差异有统计学意义(4.28±0.94比6.12±1.51,P＜0.05).光镜下LPS-NO组大鼠肺纤维素沉积较吸入空气的大鼠有所减少.结论 早期吸入20×10-6 NO可抑制急性肺损伤大鼠PAI-1的高表达,缓解纤溶失衡,减少纤维蛋白沉积,减轻肺损伤;吸入NO可减少急性肺损伤时肺组织iNOS活性和NO产量,此作用与PAI-1表达下调密切相关,因此可将研究内源性NO系统调节PAI-1表达的信号通路作为下一步的研究方向,为设计新疗法提供思路.