Angiotensin-converting enzyme 2 alleviates liver fibrosis through the renin-angiotensin system

The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.

In vitro cleavage of hepatitis B virus C mRNA by 10-23 DNA enzyme

BACKGROUND: 10-23 DNA enzyme is one kind of de-oxyribozymes for RNA cleavage. The inhibition effects of 10-23 DNA enzyme on the expression of the HBV C gene in HepG2. 2. 15 cells were demonstrated previously. The aim of this study was to further explore the cleavage activities of 10-23 DNA enzyme targeting at HBV C gene mRNA in vitro. METHODS: 10-23 DNA enzyme named Drz-HBV-C-9 specific to HBV C gene ORF A1816UG was designed and synthesized. HBV C gene mRNA was obtained by the in vitro transcription method. Cleavage activities of Drz-HBV-C-9 were observed in vitro. Values of kinetic parameters including Km,Kcat and Kcat/Km were calculated accordingly. RESULTS: Under the certain cleavage conditions, Drz-HBV-C-9 could efficiently cleave target mRNA at specific sites in vitro. Cleavage products of 109nt plus 191nt were obtained. The kinetic parameters, Km,Kcat and Kcat/ Km for Drz-HBV-C-9, were 1.4 ×10-9 mol, 1.6 min-1 and 1.1 × 109 mol-1 · min-1, respectively. CONCLUSIONS: 10-23 DNA enzyme targeting at HBV C gene mRNA possesses specific cleavage activities in vitro. This would be a potent antiviral strategy with respect to HBV gene therapy.

A new angiotensin-converting enzyme inhibitor from Peperomia pellucida(L.) Kunth

Objective:To isolate,identify,and evaluate a new angiotensin-converting enzyme inhibitor from Peperomia pellucida(L.)Kunth herbs.Methods:A dried sample of Peperomia pellucida herb was successively macerated with n-hexane and ethyl acetate.The ethyl acetate extract solution was evaporated to obtain the crude extract.Vacuum liquid column chromatography and thin layer chromatography were performed to obtain two pure compounds.Then,both compounds were elucidated and identified using the spectroscopic method.Angiotensin-converting enzyme inhibitory activity studies of both compounds were determined using angiotensin-converting enzyme kit WST-1 with spectrophotometer microplate reader 96-well at 450 nm wavelength.Results:Two bioactive compounds were successfully isolated from Peperomia pellucida herb,including a new compound of 2,3,5-trimethoxy-9-(12,14,15-trimethoxybenzyl)-1 H-indene and pellucidin A.Both compounds demonstrated angiotensin-converting enzyme inhibitory activity,with IC50 values of 72 μM(27.95 μg/mL)and 1 1μM(4.4 μg/mL),respectively.Conclusions:In the present study,two active angiotensin-converting enzyme inhibitors were successfully isolated and purified from Peperomia pellucida which is used as an antihypertensive in traditional medicine,and support its use as an angiotensin-converting enzyme-inhibiting drug.

Exosomes derived from microglia overexpressing miR-124-3p alleviate neuronal endoplasmic reticulum stress damage after repetitive mild traumatic brain injury

We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear.In this study,we first used an HT22 scratch injury model to mimic traumatic brain injury,then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p.We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress.Furthermore,luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α,while an IRE1αfunctional salvage experiment confirmed that miR-124-3p targeted IRE1αand reduced its expression,thereby inhibiting endoplasmic reticulum stress in injured neurons.Finally,we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced.These findings suggest that,after repetitive mild traumatic brain injury,miR-124-3 can be transferred from microglia-derived exosomes to injured neurons,where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress.Therefore,microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury.

Electrochemical Enzyme Immunoassay of Tumor Marker CA15-3 with Capillary Electrophoresis

Tumor marker CA15-3 was determined by using capillary electrophoretic enzyme immunoassay with electrochemical detection (CE-EIA-ED). The method can be used to detect CA15-3 with a limit of 0.024 U/mL.

Effects of tachykinin neuropeptide NKB and A<i>β</i>(25-35) on antioxidant enzymes status in 17<i>β</i>estradiol treated aging female rats

Aging is the leading risk factor for neurodegenerative diseases and oxidative stress involved in the pathophysiology of these diseases. These changes increase during menopausal condition in females when the level of estradiol is decreased. The aim of the present study was to determine the effect of tachykinin neuropeptide, Neurokinin B (NKB) and Amyloid beta fragment Aβ (25 -?35) on 17β estradiol (E2) treated aging female rat synaptosomes of different age groups. Aging brain functions were assayed by measuring the activities of antioxidant enzymes—superoxide dismutase (SOD) and monoamine oxidase (MAO) with neuropeptides. An in-vitro incubation of Aβ (25 -?35) in E2 treated brain synaptosomes showed toxic effects on all the parameters. However, NKB and NKB combined with Aβ (25 35) showed stimulating effects in E2 treated rat brain synaptosomes. In the present study, an increase in activity of SOD and decrease in the level of MAO, in the presence of NKB and combined NKB and Aβ in E2 treated brain synaptosomes of aging rats. This study elucidates that treatment of NKB and Aβ with E2 incombination exerts more protective influence than their individual application, against excitotoxicity in age related changes.

Correlation of serum Aβ1-42 content with inflammatory factors and receptors as well as antioxidant enzymes in patients with Parkinson's Disease

Objective: To investigate the correlation of serum β-amyloid 1-42 (Aβ1-42) content with inflammatory factors and receptors as well as antioxidant enzymes in patients with Parkinson's Disease. Methods: A total of 48 patients with Parkinson's disease who were treated in this hospital between December 2014 and October 2017 were selected as Parkinson's disease group, and 50 healthy volunteers who received physical examination in this hospital during the same period were selected as normal control group. The differences in serum contents of Aβ1-42, inflammatory factors and receptors as well as antioxidant enzymes were compared between the two groups, and Pearson test was used to assess the correlation between serum Aβ1-42 content and illness in patients with Parkinson's disease. Results: Serum Aβ1-42 content of Parkinson's disease group was lower than that of normal control group;serum inflammatory factors and receptors IL-2, sIL-2R, IL-6 and sIL-6R contents were higher than those of normal control group;serum antioxidant enzymes SOD, GSH-Px, CAT and TPX contents were lower than those of control group. Pearson test showed that serum Aβ1-42 content of patients with Parkinson's disease was directly correlated with the contents of inflammatory factors and receptors as well as antioxidant enzymes. Conclusions: Serum Aβ1-42 content decreases in patient with Parkinson's disease, and the specific content is directly correlated with the condition of Parkinson's disease, and can be used as an important auxiliary indicator for diagnosis and judgment of Parkinson's disease.

Effect of Cl￣ on Behavior of Fertilizer Nitrogen, Nnmberof Microorganisms and Enzyme Activities in Soils

Pot experiments were conducted to study the effect of Cl￣- on transformation of fertilizer N, number ofmicroorganisms and enzyme activities in soils. It is indicated that Cl￣- did not show significant influenceon total number of bacteria, actinomyces and fungi, but significantly reduced the number of nitrosobacteria,which led to decrease of NO content in the soil. Application of Cl￣- to soil could significantly enhance theactivities of phosphatase and urease in the coastal saline soil and orthic aquisols. In hilly red soil, however,the application of Cl￣- at the rate of 500-1000 mg Cl￣- kg￣(-1) soil significantly decreased the activity of thetwo enzymes mentioned above.

Serum levels of angiotensin converting enzyme as a biomarker of liver fibrosis

The renin angiotensin system(RAS) is classically conceived as a circulating hormonal system involved in blood pressure control and hydroelectrolyte balance. The discovery that RAS components are locally expressed in a wide range of organs and tissues,including the liver,pointed to a role for this system in the pathogenesis of several conditions including hepatic fibrosis and cirrhosis. It has been widely reported that the classical RAS axis composed by the angiotensin converting enzyme(ACE)-angiotensin(Ang) Ⅱ-Ang type 1(AT1) receptor mediates pro-inflammatory,pro-thrombotic,and pro-fibrotic processes. On the other hand,the alternative axis comprising ACE2-Ang-(1-7)-Mas receptor seems to play a protective role by frequently opposing Ang Ⅱ action. Chronic hepatitis B(CHB) is one of the leading causes of liver fibrosis,accounting for the death of nearly one million people worldwide. Liver fibrosis is a key factor to determine therapeutic interventions for patients with CHB. However,the establishment of non-invasive and accurate methods to detect reversible stages of liver fibrosis is still a challenge. In an elegant study published in the 36 th issue of the World Journal of Gastroenterology,Noguchi et al showed the predictive value of serum ACE levels in detecting not only advanced stages of liver fibrosis but also initial and intermediate fibrotic stages. The serum levels of ACE might represent an accurate,non-invasive,widely available,and easy method to evaluate fibrosis related to CHB. Moreover,therapies involving the inhibition of the classical RAS axis components might be promising in the control of CHB-related liver fibrosis.

Impact of Stone Enzyme Wash and Acid Wash Based on Denim Garments

The aim of this project is to find out the changes that occur in physical properties of denim when it is subjected to enzyme stone and acid wash or to find out the impact of enzyme stone and acid wash. 97% cotton 3% elastomer twill, weave 3/1, construction 72 × 40/9 × 7 indigo dyed denim fabric leg panels as per lab standard recipe are used here to examine. Firstly, desizing was done as pre-treatments and after treatment was silicon softener. After washing process, different samples from both washing are going to express different behavior on physical properties. This experiment is done to find out the discrimination in tearing strength, shrinkage %, color fastness to wash, color fastness to rubbing, pH rate between stone enzyme wash and acid wash of denim garments.

5'-NT和γ-GT在婴儿肝炎综合征与胆道闭锁鉴别诊断中的价值

目的观察血清5'-核苷酸酶(5'-NT)、γ-谷氨酰转肽酶(γ-GT)活性的变化在淤胆型婴儿肝炎综合征与胆道闭锁鉴别诊断中的价值。方法采用法国梅里埃公司5'-NT诊断试剂盒,同时采用全自动生化分析仪测定60例阻塞性黄疸(28例胆道闭锁和32例婴儿肝炎)患儿及20例正常对照组婴儿血清5'-NT,γ-GT,血清总胆红素(TBILT),直接胆红素(DBILT)水平。结果在28例胆道闭锁和32例婴儿肝炎病例中,5'-NT和γ-GT均数较20例正常对照组升高(P<0.05),5'-NT和γ-GT均数在胆道闭锁组明显高于淤胆型婴儿肝炎综合征组(P<0.05),在胆道闭锁病例中,5'-NT与γ-GT、TBILT和DBILT呈正相关(P<0.05)。结论血清5'-NT及γ-GT的测定有助于淤胆型婴儿肝炎综合征和胆道闭锁的鉴别诊断。

Renin-angiotensin system in the pathogenesis of liver fibrosis

Hepatic fibrosis is considered a common response to many chronic hepatic injuries. It is a multifunctional process that involves several cell types, cytokines, chemokines and growth factors leading to a disruption of homeostatic mechanisms that maintain the liver ecosystem. In spite of many studies regarding the development of fibrosis, the understanding of the pathogenesis remains obscure. The hepatic tissue remodeling process is highly complex, resulting from the balance between collagen degradation and synthesis. Among the many mediators that take part in this process, the components of the Renin angiotensin system （RAS） have progressively assumed an important role. Angiotensin （Ang） II acts as a profibrotic mediator and Ang-（1-7）, the newly recognized RAS component, appears to exert a counter-regulatory role in liver tissue. We briefly review the liver fibrosis process and current aspects of the RAS. This review also aims to discuss some experimental evidence regarding the participation of RAS mediators in the pathogenesis of liver fibrosis, focusing on the putative role of the ACE2-Ang-（1-7）- Mas receptor axis.

Relationship between angiotensin-(1-7) and angiotensin Ⅱ correlates with hemodynamic changes in human liver cirrhosis

AIM： To measure circulating angiotensins at different stages of human cirrhosis and to further evaluate a possible relationship between renin angiotensin system （RAS） components and hemodynamic changes. METHODS： Patients were allocated into 4 groups： mild-to-moderate liver disease （MLD）, advanced liver disease （ALD）, patients undergoing liver transplantation, and healthy controls. Blood was collected to determine plasma renin activity （PRA）, angiotensin （Ang） Ⅰ, Ang Ⅱ, and Ang-（1-7） levels using radioimmunoassays. During liver transplantation, hemodynamic parameters were determined and blood was simultaneously obtained from the portal vein and radial artery in order to measure RAS components. RESULTS： PRA and angiotensins were elevated in ALD when compared to MLD and controls （P 〈 0.05）. In contrast, Ang Ⅱ was significantly reduced in MLD. Ang-（1-7）/Ang Ⅱ ratios were increased in MLD when compared to controls and ALD. During transplantation, Ang Ⅱ levels were lower and Ang-（1-7）/Ang Ⅱ ratios were higher in the splanchnic circulation than in the peripheral circulation （0.52 ± 0.08 vs 0.38 ±0.04, P 〈 0.02）, whereas the peripheral circulating Ang Ⅱ/Ang Ⅰ ratio was elevated in comparison to splanchnic levels （0.18 ±0.02 vs 0.13 ±0.02, P 〈 0.04）. Ang-（1-7）/ Ang Ⅱ ratios positively correlated with cardiac output （r = 0.66） and negatively correlated with systemic vascular resistance （r = -0.70）. CONCLUSION： Our findings suggest that the relationship between Ang-（1-7） and Ang Ⅱ may play a role in the hemodynamic changes of human cirrhosis.

Purification and characterization of cold-active endo-1,4-β-glucanase produced by Pseudoalteromonas sp. AN545 from Antarctica

A bacterium hydrolyzing carboxymethylcellulose, isolated from Antarctic sea ice, was identified as Pseudoalteromonas sp. based on 16S rDNA gene sequences and named as Pseudoalteromonas sp. AN545. The extracellular endo-1,4-β-glucanase AN-1 was purified successively by ammonium sulfate precipitation, DEAE-Sepharose ion exchange chromatography and Sephadex G-75 gel filtration chromatography. The molecular mass of AN-1 was estimated to be 47.5 kDa utilizing SDS-PAGE and gel chromatography analysis. AN-1 could hydrolyze caboxymethylcellulose, avicel and β-glucan, but not cellobiose, xylan and p-Nitrophenyl-β-D-glucopyranoside. The optimal temperature and pH for the β-glucanase activity of AN-1 were determined to be at 30℃ and pH 6.0, respectively. AN-1 was stable at acidic solutions of pH 5.0-6.5 and temperatures below 30℃ for 1 h. Moreover, the specific activity was enhanced by Ca2＋ and Mg2., and inhibited by Cu2＋. The kinetic parameters Michaelis constant （Km） and maximum velocity （Vmax） of AN-1 were 3.96 mg/mL and 6.06×10-2 mg/（min.mL）, respectively.

Crystal Structures of Urokinase-type Plasminogen Activator in Complex with 4-(Aminomethyl) Benzoic Acid and 4-(Aminomethyl-phenyl)-methanol

Urokinase-type plasminogen activator （uPA） is a trypsin-like serine protease and plays a key role in several biological processes, including tissue remodeling, cell migration, and matrix degradation. The inhibitors of uPA have been shown to prevent the spread of metastasis and tumor growth, and accordingly uPA is widely recognized as a target for the treatment of cancer. In this work, we report the crystal structures of the complexes of uPA with its inhibitors： 4- （aminomethyl）-benzoic acid （AMBA） and 4-（aminomethyl-phenyl）-methanol （AMPM）, both at a resolution of 2.35 А. The inhibitory constants of these two inhibitors were measured by a chromogenic competitive assay, and it was found that AMBA is a better inhibitor for uPA （Ki = 2.68 mM） than AMPM （Ki = 13.99 mM）. The structural study shows that the binding mode of inhibitor AMBA on uPA is similar to that of AMPM on uPA, both docked into the active site S1 pocket of uPA. Structural details of these complexes are provided to explain the difference of inhibitory constants.

Ocular renin-angiotensin system with special reference in the anterior part of the eye

The renin-angiotensin system(RAS) regulates blood pressure(BP) homeostasis, systemic fluid volume and electrolyte balance. The RAS cascade includes over twenty peptidases, close to twenty angiotensin peptides and at least six receptors. Out of these, angiotensin Ⅱ, angiotensin converting enzyme 1 and angiotensin Ⅱ type 1 receptor(AngⅡ-ACE1-AT1R) together with angiotensin(1-7), angiotensin converting enzyme 2 and Mas receptor(Ang(1-7)-ACE2-Mas R) are regarded as the main components of RAS. In addition to circulating RAS, local RA-system exists in various organs. Local RA-systems are regarded as tissue-specific regulatory system accounting for local effects and long term changes in different organs. Many of the central components such as the two main axes of RAS: AngⅡ-ACE1-AT1 R and Ang(1-7)-ACE2-Mas R, have been identified in the human eye. Furthermore, it has been shown that systemic antihypertensive RAS- inhibiting medications lower intraocular pressure(IOP). These findings suggest the crucial role of RAS not only in the regulation of BP but also in the regulation of IOP, and RAS potentially plays a role in the development of glaucoma and antiglaucomatous drugs.

Advances in angiotensin-(1-7) and atrial fibrillation

Atrial fibrillation (AF) is one of the most common arrhythmias in clinic. Atrial fibrillation and its complications are one of the important causes of death. Despite the development of new therapies, including catheter ablation, the treatment of atrial fibrillation remains an important and arduous task. Current studies on the mechanism of atrial fibrillation show that the occurrence and development of atrial fibrillation mainly involves the electrophysiological mechanism of the heart and the pathophysiological mechanism of the heart. Atrial remodeling plays an important role in the process of atrial fibrillation. Atrial remodeling includes electrical remodeling of atrial structure. The early stage of atrial remodeling is characterized by electrophysiological and ion channel changes, while the late stage is characterized by amyloidosis and fibrosis of extracellular matrix and atrial muscle. Angiotensin-converting enzyme 2 and angiotensin-(1-7) are important components of renin-angiotensin-aldosterone system. Recent studies have shown that angiotensin - (1-7) plays an important protective role in the occurrence and development of atrial fibrillation. In this paper, the relationship between angiotensin - (1-7) and atrial remodeling during atrial fibrillation and its research progress are reviewed.

Purification and Some Properties of Endo-1,4-β-Glucanases of Trichoderma harzianum UzCF-28

This work aimed at isolation, purification and study of biochemical features of cellulolytic enzymes synthesized by Trichoderma harzianum UzCF-28 strain. Strain UzCF-28 revealed a high cellulolytic activity during submerged cultivation in the liquid culture on modified Mandels nutrient medium, where wheat straw was used as a source of carbon. As a result of purification by precipitation with ammonium sulfate and further ion exchange chromatography, two isoforms of endo- 1,4-β-glucanase-EG II and EG III with molecular weight of 135 and 75 kDa respectively were revealed. The pH optimum for EG I and EG III was 4.5, while for EG II—4.7, irrespective of the applied substrates—either CMC or “Whatman filter” paper. Heating up to 40°C of EG III did not lead to its inactivation, and on the contrary, its activity increased by more than three times comparing to the initial activity of the enzyme, i.e. thermostability of EG III among tested enzymes significantly varied.

Antioxidant metabolic system and comparative proteomics analysis in winter turnip rape(Brassica rapa L.)under cold stress

Winter turnip rape(Brassica rapa L.)is widely cultivated in winter in Northwest China,however,its cold-tolerant mechanism remains insufficiently understood.In this study,winter turnip rape cultivar Longyou 7,a cold-tolerant variety,was used as material,whose accumulation of H_(2)O_(2) and O_(2)^(·-),antioxidant enzyme activity as well as differences in protein expression based on two-dimensional gel electrophoresis(2-DE)technique under -4℃ stress were analyzed.Results showed that,production of H_(2)O_(2) and O_(2)^(·-) were increased in Longyou 7 leaves,simultaneously,SOD and POD activities were also obviously rosed up,but the activities of CAT and APX were gradually reduced with the temperature.Thirty-six differential protein spots were successfully identified between control and treatments group by using mass spectrometry analysis.Among them,4 differential protein spots were induced under cold stress,and 2 were inhibited at-4℃.Functional analysis found that these identified proteins mainly participated in photosynthesis,carbohydrate metabolism,defense,protein synthesis,enzyme activity,redox and membrane metabolism,respectively.Additionally,13 proteins'function were still unknown.In conclusion,strong antioxidant capacity and cell defense ability might play important roles in Longyou 7 response to cold stress.

黑逍遥散对AD模型小鼠海马区Aβ_(1-42),GSK-3β,NEP,IDE表达的影响

目的:研究黑逍遥散对阿尔茨海默症(Alzheimer disease,AD)小鼠海马区β淀粉样多肽1-42(β-amyloid 1-42peptide,Aβ1-42),糖原合成酶激酶-3(glycogen synthase kinase-3β,GSK-3β),脑啡肽酶(neprilysin,NEP),胰岛素抵抗酶(insulindegrading enzyme,IDE)表达的影响。方法:42只APP/PSI双转基因小鼠称体质量后,按随机原则分为4组,分别为模型组,阳性药组(盐酸多奈哌齐,3. 25 mg·kg-1),黑逍遥散高、低剂量组(6,3 g·kg-1)。10只同月龄、同种系的野生型C57BL/6J小鼠为正常组。连续灌胃12周后,Morris水迷宫予以行为学检测,苏木素-伊红(HE)染色观察海马神经元的形态改变,采用免疫组化技术分别检测小鼠海马区Aβ1-42,GSK-3β,NEP,IDE蛋白的表达。结果:治疗3个月后,与正常组比较,AD模型组小鼠,逃避潜伏期均延长,跨原平台次数减少(P <0. 01),小鼠海马区Aβ1-42,GSK-3β蛋白阳性表达显著增强,NEP与IDE蛋白阳性表达显著减弱(P <0. 01),HE染色显示AD模型小鼠海马神经细胞损伤严重;与模型组比较,用药各组小鼠的逃避潜伏期均显著缩短、跨原平台次数均显著增加(P <0. 05,P <0. 01),小鼠海马区Aβ1-42,GSK-3β蛋白阳性表达显著减弱,NEP与IDE蛋白阳性表达显著增强(P <0. 05,P <0. 01),HE染色显示各治疗组小鼠海马神经细胞损伤减轻。结论:黑逍遥散能够显著改善AD小鼠的学习记忆能力,可能与调节Aβ在海马区的异常沉积和降解作用等方面来减轻AD小鼠认知能力损伤有关。