Impact of endogenous and exogenous nitrogen species on macrophage extracellular trap (MET) formation by bone marrow-derived macrophages.

Macrophage extracellular traps (METs) represent a novel defense mechanism in the antimicrobial arsenal of macrophages. However, mechanisms of MET formation are still poorly understood and this is at least partially due to the lack of reliable and reproducible models. Thus, we aimed at establishing a protocol of MET induction by bone marrow-derived macrophages (BMDMs) obtained from cryopreserved and then thawed bone marrow (BM) mouse cells. We report that BMDMs obtained in this way were morphologically (F4/80+) and functionally (expression of inducible nitric oxide (NO) synthase and NO production) differentiated and responded to various stimuli of bacterial (lipopolysaccharide, LPS), fungal (zymosan) and chemical (PMA) origin. Importantly, BMDMs were successfully casting METs composed of extracellular DNA (extDNA) serving as their backbone to which proteins such as H2A.X histones and matrix metalloproteinase 9 (MMP-9) were attached. In rendered 3D structure of METs, extDNA and protein components were embedded in each other. Since studies had shown the involvement of oxygen species in MET release, we aimed at studying if reactive nitrogen species (RNS) such as NO are also involved in MET formation. By application of NOS inhibitor - L-NAME or nitric oxide donor (SNAP), we studied the involvement of endogenous and exogenous RNS in traps release. We demonstrated that L-NAME halted MET formation upon stimulation with LPS while SNAP alone induced it. The latter phenomenon was further enhanced in the presence of LPS. Taken together, our findings demonstrate that BMDMs obtained from cryopreserved BM cells are capable of forming METs in an RNS-dependent manner.

Anti-cancer effect of Rumex obtusifolius in combination with arginase/nitric oxide synthase inhibitors via downregulation of oxidative stress, inflammation, and polyamine synthesis.

Cancer continues to be a leading cause of death worldwide, making the development of new treatment methods crucial in the fight against it. With cancer incidence rates increasing worldwide, ongoing research must focus on identifying new and effective ways to prevent and treat the disease. The combination of herbal extracts with chemotherapeutic agents has gained much interest as a novel strategy to combat cancer. Rumex obtusifolius L. is a wild plant known for its medicinal properties and is widely distributed worldwide. Our preclinical evaluations suggested that R. obtusifolius seed extracts possessed cancer-inhibiting properties and we also evaluated the beneficial effects of the arginase inhibitor NG-hydroxy-nor-L-arginine and nitric oxide inhibitor NG-nitro-L-arginine methyl ester in the treatment of breast cancer. The current study aimed to combine these observations and evaluate the antioxidant and antitumor properties of R. obtusifolius extracts alone and in combination with the arginase and nitric oxide synthase inhibitors. Metabolic characterization of the plant extract using a liquid chromatography/high-resolution mass spectrometry advanced system revealed the presence of 240 phenolic compounds many of which possess anticancer properties, according to the literature. In vitro studies revealed a significant cytotoxic effect of the R. obtusifolius extracts on the human colon (HT29) and breast cancer (MCF-7) cell lines. Thus, a new treatment approach of combining R. obtusifolius bioactive phytochemicals with the arginase and nitric oxide synthase inhibitors NG-nitro-L-arginine methyl ester and/or NG-hydroxy-nor-L-arginine, respectively, was proposed and could potentially be an effective way to treat breast cancer. Indeed, these combinations showed immunostimulatory, antiproliferative, antioxidant, anti-inflammatory, and antiangiogenic properties in a rat breast cancer model.

The Angiogenesis Inhibitor Isthmin-1 (ISM1) Is Overexpressed in Experimental Models of Glomerulopathy and Impairs the Viability of Podocytes.

Focal segmental glomerulosclerosis (FSGS) is a major cause of end-stage renal disease and remains without specific treatment. To identify new events during FSGS progression, we used an experimental model of FSGS associated with nephroangiosclerosis in rats injected with L-NAME (Nω-nitro-L-arginine methyl ester). After transcriptomic analysis we focused our study on the role of Isthmin-1 (ISM1, an anti-angiogenic protein involved in endothelial cell apoptosis. We studied the renal expression of ISM1 in L-NAME rats and other models of proteinuria, particularly at the glomerular level. In the L-NAME model, withdrawal of the stimulus partially restored basal ISM1 levels, along with an improvement in renal function. In other four animal models of proteinuria, ISM1 was overexpressed and localized in podocytes while the renal function was degraded. Together these facts suggest that the glomerular expression of ISM1 correlates directly with the progression-recovery of the disease. Further in vitro experiments demonstrated that ISM1 co-localized with its receptors GRP78 and integrin αvß5 on podocytes. Treatment of human podocytes with low doses of recombinant ISM1 decreased cell viability and induced caspase activation. Stronger ISM1 stimuli in podocytes dropped mitochondrial membrane potential and induced nuclear translocation of apoptosis-inducing factor (AIF). Our results suggest that ISM1 participates in the progression of glomerular diseases and promotes podocyte apoptosis in two different complementary ways: one caspase-dependent and one caspase-independent associated with mitochondrial destabilization.

Hydrogen suppresses oxidative stress by inhibiting the p38 MAPK signaling pathway in preeclampsia.

BACKGROUND: Hypertensive disorders complicating pregnancy (HDCP) are one of the most serious medical disorders during pregnancy. OBJECTIVES: To investigate the effects of hydrogen on the mitogen-activated protein kinase (MAPK) signaling pathway in preeclampsia (PE). MATERIAL AND METHODS: The N(omega)-nitro-L-arginine methyl ester (L-NAME)-induced PE model with Sprague Dawley (SD) rats was employed. An inhibitor of MAPK signaling pathways (SB203580) was used as a p38 MAPK inhibitor. The SD rats were randomized into 5 groups: non-pregnant (NP); normal pregnancy (P); pregnancy + L-NAME (L); pregnancy + L-NAME + hydrogen-rich saline (LH); and pregnancy + L-NAME + hydrogen-rich saline + SB203580 (LHS). The pregnancies were terminated on day 22 of gestation, and the placentas and kidneys were microscopically inspected. Tumor necrosis factor alpha (TNF-α), interleukin-1ß (IL-1ß) and malondialdehyde (MDA) levels were assessed. The mean systolic blood pressure (SBP) and level of proteinuria were recorded. The p38 MAPK mRNA expression and p-p38 MAPK protein levels were measured using real-time polymerase chain reaction (RT-PCR) and western blot, respectively. RESULTS: It was found that hydrogen-rich saline (LH group) decreased placental MDA, proteinuria, TNF-α, and IL-1ß levels in the placental tissues compared with the L group (all p < 0.05). Additionally, hydrogen-rich saline (LH group) treatment significantly decreased the p38 MAPK mRNA expression and p-p38 MAPK protein levels compared with the L group (p < 0.05). The p38 MAPK inhibitor SB203580 (LHS group) further decreased the p38 MAPK mRNA expression and p-p38 MAPK protein levels compared with the LH group (p < 0.05). CONCLUSIONS: Hydrogen can decrease the reactive oxygen species (ROS) content and inhibit the MAPK pathway. The protective effect of hydrogen may be associated with the inhibition of the p38 MAPK signaling pathway.

The L-NAME mouse model of preeclampsia and impact to long-term maternal cardiovascular health.

Preeclampsia affects ∼2-8% of pregnancies worldwide. It is associated with increased long-term maternal cardiovascular disease risk. This study assesses the effect of the vasoconstrictor N(ω)-nitro-L-arginine methyl ester (L-NAME) in modelling preeclampsia in mice, and its long-term effects on maternal cardiovascular health. In this study, we found that L-NAME administration mimicked key characteristics of preeclampsia, including elevated blood pressure, impaired fetal and placental growth, and increased circulating endothelin-1 (vasoconstrictor), soluble fms-like tyrosine kinase-1 (anti-angiogenic factor), and C-reactive protein (inflammatory marker). Post-delivery, mice that received L-NAME in pregnancy recovered, with no discernible changes in measured cardiovascular indices at 1-, 2-, and 4-wk post-delivery, compared with matched controls. At 10-wk post-delivery, arteries collected from the L-NAME mice constricted significantly more to phenylephrine than controls. In addition, these mice had increased kidney Mmp9:Timp1 and heart Tnf mRNA expression, indicating increased inflammation. These findings suggest that though administration of L-NAME in mice certainly models key characteristics of preeclampsia during pregnancy, it does not appear to model the adverse increase in cardiovascular disease risk seen in individuals after preeclampsia.

Dibutyl phthalate promotes angiogenesis in EA.hy926 cells through estrogen receptor-dependent activation of ERK1/2, PI3K-Akt, and NO signaling pathways.

Dibutyl phthalate (DBP) is an endocrine disruptor that has been widely used in various products of human use. DBP exposure has been associated with reproductive and cardiovascular diseases and metabolic disorders. Although dysfunction of the vascular endothelium is responsible for many cardiovascular and metabolic diseases, little is known about the effects of DBP on human endothelium. In this study, we investigated the effect of three concentrations of DBP (10-6, 10-5, and 10-4 M) on angiogenesis in human endothelial cell (EC) line EA.hy926 after acute exposure. Tube formation assay was used to investigate in vitro angiogenesis, whereas qRT-PCR was employed to measure mRNA expression. The effect of DBP on extracellular signal-regulated kinase 1/2 (ERK1/2), phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt), and endothelial nitric oxide (NO) synthase (eNOS) activation was examined using Western blotting, whereas the Griess method was used to assess NO production. Results show that the 24-h-long exposure to 10-4 M DBP increased endothelial tube formation, which was prevented by addition of U0126 (ERK1/2 inhibitor), wortmannin (PI3K-Akt inhibitor), and l-NAME (NOS inhibitor). Short exposure to 10-4 M DBP (from 15 to 120 min) phosphorylated ERK1/2, Akt, and eNOS in different time points and increased NO production after 24 and 48 h of exposure. Application of nuclear estrogen receptor (ER) and G protein-coupled ER (GPER) inhibitors ICI 182,780 and G-15, respectively, abolished the DBP-mediated ERK1/2, Akt, and eNOS phosphorylation and increase in NO production. In this study, we report for the first time that DBP exerts a pro-angiogenic effect on human vascular ECs and describe the molecular mechanism involving ER- and GPER-dependent activation of ERK1/2, PI3K-Akt, and NO signaling pathways.

Preeclampsia associated changes in volume density of fetoplacental vessels in Chinese women and mouse model of preeclampsia.

INTRODUCTION: Preeclampsia (PE) is associated with abnormal placental vascular structure. However, the volume density of fetoplacental vessels in PE remains unclear. Additionally, manually annotated CT angiography, which is widely used to analyze placental vessels, has issues regarding inaccuracy. Thus, computer-aided CT angiography for analyzing the volume density of fetoplacental vessels would facilitate the understanding of PE pathogenesis. METHODS: We performed computer-aided CT angiography to compare differences in placentas among 17 women with PE and 34 normotensive women. The contrast ratio in CT angiography was significantly enhanced using a three-dimensional (3-D) Hessian matrix algorithm. The PE-like mouse model was established by administration of 125 mg/kg/day NG-nitro-l-arginine methyl ester (l-NAME) for 10 days. The presence of endothelial marker CD31 was confirmed by quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC). The expression of angiogenic factors (PlGF, VEGFA, and sFlt1) in placentas was detected using qRT-PCR and western blotting. RESULTS: The volume density in fetoplacental vessels and CD31 expression were significantly reduced in women with PE and l-NAME-induced mice. Additionally, the downregulation of angiogenic factors (PlGF/VEGFA) and upregulation of an anti-angiogenic factor (sFlt1) were determined in a mouse model. DISCUSSION: Contrast-enhanced CT angiography with the aid of a 3-D Hessian matrix algorithm was performed. PE significantly affects the formation of vascular vessels, resulting in a lower volume density of fetoplacental vessels in humans and mice. This may be explained by the abnormal release of angiogenic factors during PE.

Resveratrol improved kidney function and structure in malignantly hypertensive rats by restoration of antioxidant capacity and nitric oxide bioavailability.

BACKGROUND: The main cause of death among patients with malignant hypertension is a kidney failure. The promising field in essential and malignant hypertension therapy could be centered on the amelioration of oxidative stress using antioxidant molecules like resveratrol. Resveratrol is a potent antioxidative agent naturally occurred in many plants that possess health-promoting properties. METHODS: In the present study, we investigated the therapeutic potential of resveratrol, a polyphenol with anti-oxidative activity, in NG-L-Arginine Methyl Ester (L-NAME) treated spontaneously hypertensive rats (SHR) - malignantly hypertensive rats (MHR). RESULTS: Resveratrol significantly improves oxidative damages by modulation of antioxidant enzymes and suppression of prooxidant factors in the kidney tissue of MHR. Enhanced antioxidant defense in the kidney improves renal function and ameliorates the morphological changes in this target organ. Besides, protective properties of resveratrol are followed by the restoration of the nitrogen oxide (NO) pathway. 4) Conclusion: Antioxidant therapy with resveratrol could represent promising therapeutical approach in hypertension, especially malignant, against kidney damage.

The Protective Benefit of Heme Oxygenase-1 Gene-Modified Human Placenta-Derived Mesenchymal Stem Cells in a N-Nitro-L-Arginine Methyl Ester-Induced Preeclampsia-Like Rat Model: Possible Implications for Placental Angiogenesis.

We previously reported that cytoprotective Heme oxygenase-1, HO-1 (HMOX1) gene-modified human placenta-derived mesenchymal stem cell (HO-1-PMSC) improved placental vascularization in vitro. In the current study, we explored the protective benefit of HO-1-PMSC transplantation in a preeclampsia (PE)-like rat model. A model of PE was successfully constructed by intraperitoneal injection of N-nitro-L-arginine methyl ester (L-NAME). Blood pressure and urinary protein levels were measured. Doppler ultrasound was examined to understand uteroplacental perfusion. ELISA was used to examine the serum levels of VEGF, PlGF, sFlt-1, and sEng. The placentas and fetuses were weighed to verify the improvement in pregnancy outcome. Immunohistochemical and H&E staining was used to detect microvessel density (MVD) in placental tissues and kidney pathology, respectively. The distribution of GFP-labeled PMSC in the placenta were observed under fluorescence microscopy. Blood pressure and proteinuria were reduced and kidney damage was improved. PE rat models treated with PMSC and HO-1-PMSC exhibited an increase in the quality of fetuses and placentas, MVD, VEGF, and PlGF expression, but substantially decreased expression of sFlt-1 and sEng. Doppler ultrasound showed that the placental perfusion was improved. Green fluorescent tracing experiments verified that the cells were successfully transplanted into the placenta and distributed in the blood vessels, indicating that the cells might participate in the process of angiogenesis. These results indicate that therapy with HO-1-PMSC could improve placental vascular dysplasia, increase placental perfusion, control PE symptoms, and promote pregnancy outcome by regulating the balance of angiogenic and antiangiogenic factors or directly participating in the repair of placental vessels in a PE-like rat model.

Caffeic acid attenuates gastric mucosal damage induced by ethanol in rats via nitric oxide modulation.

Anti-oxidant and anti-inflammatory properties of caffeic acid (CA) have been reported recently. In this study, the therapeutic effects of CA on ethanol-induced ulcer and the roles of nitric oxide and cholinergic pathways in these effects were investigated. Ulcer was induced by ethanol via oral gavage. Ulcer induced rats were treated with either vehicle (ulcer group) or CA (100, 250 or 500 mg/kg, per oral gavage). Macroscopic evaluation showed that 250 mg/kg CA was the effective dose. To elucidate the action mechanism of CA, 10 mg/kg l-NAME or 1 mg/kg atropine sulfate was administered to 250 mg/kg CA treated groups. All rats were decapitated 1 h after ulcer induction and gastric samples were scored macroscopically and microscopically, and analyzed for myeloperoxidase (MPO), malondialdehyde (MDA), and glutathione (GSH) levels. ANOVA test was used for statistical analyses. Macroscopic and microscopic damage scores, MDA levels and MPO activity were increased while GSH levels were decreased in ulcer group. Treatment with 250 mg/kg and 500 mg/kg CA reduced macroscopic and microscopic damage scores, decreased MPO activity and MDA levels, and preserved the depleted glutathione significantly. l-NAME administration before CA treatment elevated MDA levels, MPO activity and depleted glutathione. However, atropine sulfate had no effect on biochemical parameters. We conclude that CA ameliorates ethanol-induced gastric mucosal damage, and NO pathway contributes to this effect. On the other hand, there is a lack of evidence for the contribution of the muscarinic cholinergic system.

Novel Insights into the Mode of Action of Vasorelaxant Synthetic Polyoxygenated Chalcones.

Polyphenols consumption has been associated with a lower risk of cardiovascular diseases (CVDs) notably through nitric oxide (NO)- and estrogen receptor α (ERα)-dependent pathways. Among polyphenolic compounds, chalcones have been suggested to prevent endothelial dysfunction and hypertension. However, the involvement of both the NO and the ERα pathways for the beneficial vascular effects of chalcones has never been demonstrated. In this study, we aimed to identify chalcones with high vasorelaxation potential and to characterize the signaling pathways in relation to ERα signaling and NO involvement. The evaluation of vasorelaxation potential was performed by myography on wild-type (WT) and ERα knock-out (ERα-KO) mice aorta in the presence or in absence of the eNOS inhibitor Nω-nitro-L-arginine methyl ester (L-NAME). Among the set of chalcones that were synthesized, four (3, 8, 13 and 15) exhibited a strong vasorelaxant effect (more than 80% vasorelaxation) while five compounds (6, 10, 11, 16, 17) have shown a 60% relief of the pre-contraction and four compounds (12, 14, 18, 20) led to a lower vasorelaxation. We were able to demonstrate that the vasorelaxant effect of two highly active chalcones was either ERα-dependent and NO-independent or ERα-independent and NO-dependent. Thus some structure-activity relationships (SAR) were discussed for an optimized vasorelaxant effect.

5-Lipoxagenase deficiency attenuates L-NAME-induced hypertension and vascular remodeling.

BACKGROUND: Abnormalities of the L-arginine-nitric oxide pathway induce hypertension. 5-Lipoxygenase (5-LO) is the key enzyme involved in synthesis of leukotrienes (LTs). However, whether nitricoxide synthase dysfunction induces hypertensive vascular remodeling by regulating 5-LO activity and its downstream inflammatory metabolites remains unknown. METHODS AND RESULTS: Six-week L-NAME treatment significantly induced hypertension and vascular remodeling in both wild-type (WT) and 5-LO-knockout (5-LO-KO) mice, and blood pressure in caudal and carotid arteries was lower in 5-LO-KO than WT mice with L-NAME exposure. On histology, L-NAME induced less media thickness, media-to-lumen ratio, and collagen deposition and fewer Ki-67-positive vascular smooth muscle cells (VSMCs) but more elastin expression in thoracic and mesenteric aortas of 5-LO-KO than L-NAME-treated WT mice. L-NAME significantly increased LT content, including LTB4 and cysteinyl LT (CysLTs), in plasma and neutrophil culture supernatants from WT mice. On immunohistochemistry, L-NAME promoted the colocalization of 5-LO and 5-LO-activating protein on the nuclear envelope of cultured neutrophils, which was accompanied by elevated LT content in culture supernatants. In addition, LTs significantly promoted BrdU incorporation, migration and phenotypic modulation in VSMCs. CONCLUSION: L-NAME may activate the 5-LO/LT pathway in immune cells, such as neutrophils, and promote the products of 5-LO metabolites, including LTB4 and CysLTs, which aggravate vascular remodeling in hypertension. 5-LO deficiency may protect against hypertension and vascular remodeling by reducing levels of 5-LO downstream inflammatory metabolites.

Tetramethylpyrazine reduces the consequences of nitric oxide inhibition in pregnant rats.

Pre-eclampsia (PE) is closely associated with perinatal morbidity and mortality and we want to investigate tetramethylpyrazine (TMP)'s effects on PE. Pregnant Sprague-Dawley rats were randomly divided into five groups: normal pregnant (PC), PE, PE+TMP 20 mg/kg, PE+TMP 40 mg/kg, and PE+TMP 60 mg/kg group. The PE rat model was established via L-NAME treatment. Systolic blood pressures (SBP) and urinary protein concentration were detected via the tail-cuff method and CBB kit, respectively. mRNA levels of key genes were analyzed via quantitative PCR and protein levels of key genes were measured by ELISA or western blot. TMP decreased SBP and urinary protein concentration of PE rats. TMP inhibited L-NAME-induced decrease in pups alive ratio, pups weight, and the ratio of pups/placenta weight and reversed L-NAME induced changes in placental histology, whereas it had little effect on placental weight. Urinary nephrin and podocin expressions were enhanced and serum placental growth factor level was decreased in PE rats, whereas TMP inhibited the above phenomena. TMP suppressed L-NAME-induced sFlt-1 upregulation in serums and kidneys of PE rats, whereas it downregulated IL-6 and MCP-1 expression in PE rats' serums, placentas and kidneys. TMP also suppressed the increase in placental sFlt-1 and vascular endothelial growth factor level caused by L-NAME. In addition, TMP inhibited CHOP and GRP78 expressions and decreased the ratio of p-elF2α/elF2α in PE rats. TMP attenuated the consequences of NO inhibition in pregnant rats.

Copper nanoparticles modify the blood plasma antioxidant status and modulate the vascular mechanisms with nitric oxide and prostanoids involved in Wistar rats.

BACKGROUND: We aimed to analyze whether a diet supplemented with a standard dose of copper (Cu) in the form of nanoparticles, as an alternative to carbonate, exerts beneficial effects within the vasculature and improves the blood antioxidant status. METHODS: Male Wistar rats were fed for 8 weeks with a diet supplemented with Cu (6.5 mg Cu/kg in the diet) either as nanoparticles (40 nm diameter) or carbonate - the control group. Moreover, a negative control was not supplemented with Cu. At 12 weeks of age, blood samples, internal organs and thoracic aorta were taken for further analysis. Blood antioxidant mechanism was measured together with Cu and Zn. RESULTS: Diet with Cu as nanoparticles resulted in an elevated catalase activity and ferric reducing ability of plasma, however decreased Cu (plasma), and ceruloplasmin (Cp) compared to carbonate. The participation of vasoconstrictor prostanoid was increased, as indomethacin did not modify the acetylcholine (ACh)-induced response. Arteries from Cu nanoparticle and carbonate rats exhibited a reduced maximal contraction to potassium chloride and an increased response to noradrenaline. The endothelium-dependent vasodilation to ACh was enhanced while exogenous NO donor, sodium nitroprusside, did not modify the vascular response. Down-regulation of BKCa channels influenced hyperpolarizing mechanism. The superoxide dismutase and HDL-cholesterol were decreased opposite to an increased lipid hydroperoxides, malondialdehyde, Cu (plasma and liver) and Cp. CONCLUSION: Despite the increased antioxidant capacity in blood of Cu nanoparticle fed rats, vasoconstrictor prostanoids and NO are involved in vascular regulation.

Physical exercise prevents memory impairment in an animal model of hypertension through modulation of CD39 and CD73 activities and A2A receptor expression.

: Background: Central nervous system function has been emerging as an approach to understand hypertension-mediated memory dysfunction, and chronic exercise is able to modulate the purinergic system. METHOD: Herein, we investigated the effect of chronic swimming training on the purinergic system in cortex and hippocampus of L-NAME-induced hypertensive rats. Male Wistar rats were divided into four groups: Control, Exercise, L-NAME and Exercise L-NAME. Inhibitory avoidance test was used to assess memory status. NTPDase, CD73 and adenosine deaminase activities and expression, and P2 receptors expression were analyzed. Data were analyzed using two-way ANOVA and Kruskal-Wallis tests, considering P less than 0.05. RESULTS: Physical exercise reduced the blood pressure and prevented memory impairment induced by L-NAME model of hypertension. L-NAME treatment promoted an increase in NTPDase1, NTPDase3 and CD73 expression and activity in the cortex. A2A expression is increased in hippocampus and cortex in the hypertension group and exercise prevented this overexpression. CONCLUSION: These changes suggest that hypertension increases adenosine generation, which acts through A2A receptors, and exercise prevents these effects. These data may indicate a possible mechanism by which exercise may prevent memory impairment induced by L-NAME.

Protective effect of human umbilical cord mesenchymal stem cell exosomes on preserving the morphology and angiogenesis of placenta in rats with preeclampsia.

AIM: This study aims to investigate the effect of human umbilical cord mesenchymal stem cell exosomes (hucMSC-Ex) on placental tissue and angiogenesis in rats with preeclampsia (PE). METHOD: The expression of MSC surface markers were identified by flow cytometry. Alizarin red staining and oil red O staining were used to examine osteogenic and adipogenic differentiation of hucMSCs. Western blotting was used to determine expressions of CD63 and CD81 in hucMSC-Ex. PE rat models were established using endothelial nitric oxide synthase, eNOS)NG-Nitro-l-arginine Methyl Ester, which were then treated with exosome (Exo) of low dosage (L-Exo), Exo of medium dosage (M-Exo) and Exo of high dosage (H-Exo). The blood pressure at the 15d, 17d and 19d of pregnancy and 24-h urinary protein were measured. TUNEL staining and immunohistochemistry were applied to detect the cell apoptosis and micro-vascular density (MVD) in placental tissues, respectively. Enzyme-linked immunosorbent assay (ELISA) was used to examine serum levels of vascular endothelial growth factor (VEGF) and soluble fms-like tyrosine kinase receptor-1 (sFlt1). RESULTS: In vitro cultured hucMSCs showed expression of MSC surface markers (CD29, CD90 and CD105), and no expression of CD34 and CD45. Besides, the isolated exosomes expressed the exosome markers (CD63 and CD81). In response to the treatment of L-Exo, M-Exo and H-Exo, the blood pressure of PE rat models on the 17 d and the 19 d as well as the 24-h urinary protein were substantially decreased. Moreover, at the 21 d, PE rat models treated with L-Exo, M-Exo and H-Exo exhibited an increase in the number and quality of fetuses, placenta quality, MVD and VEGF expression, but substantial decreased cell apoptosis and expression of sFlt1. The influence of Exos was exerted in a dosage dependent manner. CONCLUSION: hucMSC-Ex, in a dose-dependent manner, can improve the morphology of placental tissue in rats with PE, by inhibiting cell apoptosis and promoting angiogenesis in placental tissue.

Establishment of a radiotelemetric recording technique in mice to investigate gastric slow waves: Modulatory role of putative neurotransmitter systems.

NEW FINDINGS: What is the central question of this study? Gastric slow waves originating from the interstitial cells of Cajal-smooth muscle syncytium are usually studied in culture or in tissue segments, but nobody has described recordings of slow waves from awake, freely moving mice. Can radiotelemetry be used to record slow waves, and do they respond predictably to drug treatment? What is the main finding and its importance? Radiotelemetry can be used to record slow waves from awake, freely moving mice, permitting an examination of drug actions in vivo, which is crucial to drug discovery projects for characterizing the effects of drugs and metabolites on gastrointestinal function. ABSTRACT: The mouse is the most commonly used species in preclinical research, and isolated tissues are used to study slow waves from the interstitial cells of Cajal-smooth muscle syncytium of the gastrointestinal tract. The aim of this study was to establish a radiotelemetric technique in awake mice to record gastric myoelectric activity from the antrum to gain insight into the effects of endogenous modulatory systems on slow waves. Under general anaesthesia, two biopotential wires from a telemetry transmitter were sutured into the antrum of male ICR (imprinting control region) mice. The animals were allowed 1 week to recover from surgery before the i.p. administration of drugs to stimulate or inhibit slow waves. The basal dominant frequency of slow waves was 6.96 ± 0.43 c.p.m., and the percentages of power in the bradygastric, normogastric and tachygastric ranges were 6.89 ± 0.98, 37.32 ± 1.72 and 34.38 ± 0.77%, respectively (n = 74). Nicotine at 1 mg kg-1 increased normogastric power, but at 3 mg kg-1 it increased bradygastric power (P < 0.05). Metoclopramide at 10 mg kg-1 increased normogastric power; sodium nitroprusside at 10 mg kg-1 had latent effects on tachygastric power (P < 0.05); and l-NAME at 10 mg kg-1 had no effect (P > 0.05). Nicotine and bethanechol also caused varying degrees of hypothermia (>1°C reductions; P < 0.05). In conclusion, radiotelemetry can be used to record slow waves from awake, freely moving mice. In light of our findings, we recommend that studies assessing slow waves should also assess body temperature simultaneously.

L-NAME decreases the amount of nitric oxide and enhances the toxicity of cadmium via superoxide generation in barley root tip.

Exposure of barley roots to mM concentrations of L-NAME for 30 min caused a considerable root growth inhibition in a dose-dependent manner. The inhibition of root growth was higher in seedlings co-treated with Cd and L-NAME, compared with roots treated with Cd alone, despite the fact that L-NAME markedly reduced the uptake of Cd by roots. Treatment of roots with L-NAME evoked a decrease in NO level in both control and Cd-treated root tips only after a relatively long lag period, which overlaps with an increase in superoxide and H2O2 levels and peroxynitrite generation. L-NAME-induced root growth inhibition is alleviated not only by the application of the NO donor SNP but also by the ROS and peroxynitrite scavengers. Our results indicate that L-NAME, a NOS inhibitor in the animal kingdom, indeed evokes NO depletion also in the plant tissues; however, it does not occur due to the action of L-NAME as an inhibitor of NOS or NOS-like activity, but as a consequence of L-NAME-induced enhanced superoxide generation, leading to increased peroxynitrite level in the root tips due to the reaction between superoxide and NO.

Herpes Simplex Virus Type 1 Infects Enteric Neurons and Triggers Gut Dysfunction via Macrophage Recruitment.

Herpes Simplex Virus type 1 (HSV-1), a neurotropic pathogen widespread in human population, infects the enteric nervous system (ENS) in humans and rodents and causes intestinal neuromuscular dysfunction in rats. Although infiltration of inflammatory cells in the myenteric plexus and neurodegeneration of enteric nerves are common features of patients suffering from functional intestinal disorders, the proof of a pathogenic link with HSV-1 is still unsettled mainly because the underlying mechanisms are largely unknown. In this study we demonstrated that following intragastrical administration HSV-1 infects neurons within the myenteric plexus resulting in functional and structural alterations of the ENS. By infecting mice with HSV-1 replication-defective strain we revealed that gastrointestinal neuromuscular anomalies were however independent of viral replication. Indeed, enteric neurons exposed to UV-inactivated HSV-1 produced monocyte chemoattractant protein-1 (MCP-1/CCL2) to recruit activated macrophages in the longitudinal muscle myenteric plexus. Infiltrating macrophages produced reactive oxygen and nitrogen species and directly harmed enteric neurons resulting in gastrointestinal dysmotility. In HSV-1 infected mice intestinal neuromuscular dysfunctions were ameliorated by in vivo administration of (i) liposomes containing dichloromethylene bisphosphonic acid (clodronate) to deplete tissue macrophages, (ii) CCR2 chemokine receptor antagonist RS504393 to block the CCL2/CCR2 pathway, (iii) Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME) and AR-C 102222 to quench production of nitrogen reactive species produced via iNOS. Overall these data demonstrate that HSV-1 infection makes enteric neurons recruit macrophages via production of a specific chemoattractant factor. The resulting inflammatory reaction is mandatory for intestinal dysmotility. These findings provide insights into the neuro-immune communication that occurs in the ENS following HSV-1 infection and allow recognition of an original pathophysiologic mechanism underlying gastrointestinal diseases as well as identification of novel therapeutic targets.

Nitric oxide modulates ATP-evoked currents in mouse Leydig cells.

Testosterone synthesis within Leydig cells is a calcium-dependent process. Intracellular calcium levels are regulated by different processes including ATP-activated P2X purinergic receptors, T-type Ca2+ channels modulated by the luteinizing hormone, and intracellular calcium storages recruited by a calcium-induced calcium release mechanism. On the other hand, nitric oxide (NO) is reported to have an inhibitory role in testosterone production. Based on these observations, we investigated the interaction between the purinergic and nitrergic systems in Leydig cells of adult mice. For this purpose, we recorded ATP-evoked currents in isolated Leydig cells using the whole cell patch clamp technique after treatment with L-NAME (300 µM and 1 mM), L-arginine (10, 100, 300, and 500 µM), ODQ (300 µM), and 8-Br-cGMP (100 µM). Our results show that NO produced by Leydig cells in basal conditions is insufficient to change the ATP-evoked currents and that extra NO provided by adding 300 µM L-arginine positively modulates the current through a mechanism involving the NO/cGMP signaling pathway. Thus, we report an interaction between the nitrergic and purinergic systems in Leydig cells and suggest that Ca2+ entry via the purinergic receptors can be regulated by NO.