L-arginine enhances nitrative stress and exacerbates tumor necrosis factor-alpha toxicity to human endothelial cells in culture: prevention by propofol

BPA exposure and Se deficiency caused spleen damage in chickens by nitrification stress-TNF-α

With the increasing production and demand of plastic products in life, inescapable bisphenol A (BPA) exposure results in a threat to the health of organisms. Selenium (Se) is an essential trace element for living organisms. The insufficient Se intake can cause multi-tissue organ damage. In the process of production and life, the exposure of BPA is usually accompanied by Se deficiency. In this study, the models of chicken with BPA exposure and/or Se deficiency was duplicated, the status of nitrification stress, apoptosis, necroptosis, and changes in TNF-α/FADD signaling pathways in chicken spleen were examined. At the same time, nitrification stress inhibitor and TNF-α inhibitor were introduced into MSB-1 cell model tests in vitro, indicating that BPA exposure and Se deficiency up-regulated TNF-α/FADD signaling pathway through nitrification stress, inducing necroptosis and apoptosis, and heat shock protein was also involved in this process. This study provides a new control idea for healthy poultry breeding based on Se, and also provides a new reference for toxicity control of environmental pollutants.

Preoperative Management of Surgical Patients Using Dietary Supplements: Society for Perioperative Assessment and Quality Improvement (SPAQI) Consensus Statement

The widespread use of complementary products poses a challenge to clinicians in the perioperative period and may increase perioperative risk. Because dietary supplements are regulated differently from traditional pharmaceuticals and guidance is often lacking, the Society for Perioperative Assessment and Quality Improvement convened a group of experts to review available literature and create a set of consensus recommendations for the perioperative management of these supplements. Using a modified Delphi method, the authors developed recommendations for perioperative management of 83 dietary supplements. We have made our recommendations to discontinue or continue a dietary supplement based on the principle that without a demonstrated benefit, or with a demonstrated lack of harm, there is little downside in temporarily discontinuing an herbal supplement before surgery. Discussion with patients in the preoperative visit is a crucial time to educate patients as well as gather vital information. Patients should be specifically asked about use of dietary supplements and cannabinoids, as many will not volunteer this information. The preoperative clinic visit provides the best opportunity to educate patients about the perioperative management of various supplements as this visit is typically scheduled at least 2 weeks before the planned procedure.

The impact of l-arginine supplementation on the enteral phase of experimental Trichinella spiralis infection in treated and untreated mice

The role of nitric oxide (NO) in the immunopathological response during Trichinella spiralis (T. spiralis) infection remains controversial. The amino acid, l-arginine is a NO precursor commonly used by athletes and bodybuilders as a protein supplement. As to our knowledge, there are no published studies which have tested the effect of l-arginine on the intestinal phase of experimental trichinellosis. The present work aims to investigate the effect of l-arginine on the enteral phase of experimental T. spiralis infection in albendazole-treated and untreated mice. Forty BALB/C mice infected orally with T. spiralis larvae were divided into 4 groups as follows: Group A were infected and untreated (control) mice, Group B received albendazole alone, Group C received l-arginine alone, and Group D received both l-arginine and albendazole. Compared to the control group, l-arginine supplementation showed; a significant increase in the intestinal adult worm burden, a significantly high inducible NO synthase (iNOS) expression, elevated immune markers; tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), and enhanced apoptosis. Albendazole treated-group had a significant reduction in the adult worm number (90.9%), while combined albendazole-arginine regimen showed a lower percentage of worm reduction (72.7%). During the enteral phase of T. spiralis infection, l-arginine supplementation should be taken cautiously, as it may modulate the proinflammatory immune response and subsequently affect the outcome of the infection and/or treatment.

Overexpression of inducible nitric oxide synthase in the diabetic heart compromises ischemic postconditioning

Ischemia postconditioning (PTC) can reduce myocardial ischemia/reperfusion injury. However, the effectiveness of PTC cardioprotection is reduced or lost in diabetes and the mechanisms are largely unclear. Hyperglycemia can induce overexpression of inducible nitric oxide synthesis (iNOS) in the myocardium of diabetic subjects. However, it is unknown whether or not iNOS especially its overexpression plays an important role in the loss of cardioprotection of PTC in diabetes. C57BL6 and iNOS^-/- mice were treated with streptozotocin to induce diabetes. Part of diabetic C57BL6 mice were also treated with an iNOS specific inhibitor, 1400 W. Mice were subjected to myocardial ischemia/ reperfusion with/without PTC. The hemodynamic parameters, plasma levels of cardiac troponin T (cTnT), TNF-α, IL-6 and nitric oxide (NO) were monitored. The myocardial infarct size, superoxide anion (O₂^-) generation, nitrotyrosine production and apoptosis were measured. The expression of phosphorylated Akt, endothelial NOS (eNOS), iNOS and Erk1/2 in ischemic heart were detected by immunoblot analysis. In diabetic C57BL6 and iNOS^-/- mice, the post-ischemic hemodynamics were impaired, the cTnT, TNF-α, IL-6 level, myocardial infarct size, apoptotic index, O₂^- and nitrotyrosine generation were increased and the Akt/eNOS signal pathways were inhibited. PTC improved hemodynamic parameters, reduced cTnT level, myocardial infarct size, apoptotic index, O₂^- and nitrotyrosine generation and activated Akt/eNOS and Erk1/2 signal pathways in both non-diabetic C57BL6 and iNOS^-/- mice as well as diabetic iNOS^-/- mice, but not in diabetic C57BL6 mice. PTC also increased NO production in both non-diabetic and diabetic C57BL6 and iNOS^-/- mice, and enhanced iNOS expression in non-diabetic C57BL6 mice. 1400 W restored the cardioprotection of PTC in diabetic C57BL6 mice. Our data demonstrated that PTC reduced myocardial ischemia/reperfusion injury in non-diabetic mice but not C57BL6 diabetic mice. Deletion of iNOS restored the cardioprotection of PTC in diabetic mice. Our findings suggest that iNOS plays a key role in the reduction of cardioprotection of PTC in diabetes and may provide a therapeutic target for diabetic patients.

Propofol prevents human umbilical vein endothelial cell injury from Ang II-induced apoptosis by activating the ACE2-(1-7)-Mas axis and eNOS phosphorylation

Angiotensin II (AngII), a vasoactive peptide that elevates arterial blood pressure and results in hypertension, has been reported to directly induce vascular endothelial cell apoptosis. Recent work has demonstrated that propofol pre-treatment attenuates angiotensin II-induced apoptosis in human coronary artery endothelial cells. However, the underlying mechanism remains largely unknown. Here, we investigated human umbilical vein endothelial cells (HUVECs) subjected to angiotensin II-induced apoptosis in the presence or absence of propofol treatment and found that angiotensin II-induced apoptosis was attenuated by propofol in a dose-dependent manner. Furthermore, ELISA assays demonstrated that the ratio of angiotensin (1–7) (Ang (1–7)) to Ang II was increased after propofol treatment. We examined the expression of ACE2, Ang (1–7) and Mas and found that the ACE2-Ang (1–7)-Mas axis was up-regulated by propofol, while ACE2 overexpression increased phosphorylated endothelial nitric oxide synthase (phosphorylated eNOS) expression and siACE2 resulted in the repression of endothelial nitric oxide synthase (eNOS) phosphorylation. In conclusion, our study revealed that propofol can inhibit endothelial cell apoptosis induced by Ang II by activating the ACE2-Ang (1–7)-Mas axis and further up-regulating the expression and phosphorylation of eNOS.

An increased need for dietary cysteine in support of glutathione synthesis may underlie the increased risk for mortality associated with low protein intake in the elderly

Restricted dietary intakes of protein or essential amino acids tend to slow aging and boost lifespan in rodents, presumably because they downregulate IGF-I/Akt/mTORC1 signaling that acts as a pacesetter for aging and promotes cancer induction. A recent analysis of the National Health and Nutrition Examination Survey (NHANES) III cohort has revealed that relatively low protein intakes in mid-life (under 10 % of calories) are indeed associated with decreased subsequent risk for mortality. However, in those over 65 at baseline, such low protein intakes were associated with increased risk for mortality. This finding accords well with other epidemiology correlating relatively high protein intakes with lower risk for loss of lean mass and bone density in the elderly. Increased efficiency of protein translation reflecting increased leucine intake and consequent greater mTORC1 activity may play a role in this effect; however, at present there is little solid evidence that leucine supplementation provides important long-term benefits to the elderly. Aside from its potential pro-anabolic impact, higher dietary protein intakes may protect the elderly in another way-by providing increased amino acid substrate for synthesis of key protective factors. There is growing evidence, in both rodents and humans, that glutathione synthesis declines with increasing age, likely reflecting diminished function of Nrf2-dependent inductive mechanisms that boost expression of glutamate cysteine ligase (GCL), rate-limiting for glutathione synthesis. Intracellular glutathione blunts the negative impact of reactive oxygen species (ROS) on cell health and functions both by acting as an oxidant scavenger and by opposing the pro-inflammatory influence of hydrogen peroxide on cell signaling. Fortunately, since GCL's K m for cysteine is close to intracellular cysteine levels, increased intakes of cysteine-achieved from whole proteins or via supplementation with N-acetylcysteine (NAC)-can achieve a compensatory increase in glutathione synthesis, such that more youthful tissue levels of this compound can be restored. Supplementation with phase 2 inducers-such as lipoic acid-can likewise increase glutathione levels by promoting increased GCL expression. In aging humans and/or rodents, NAC supplementation has exerted favorable effects on vascular health, muscle strength, bone density, cell-mediated immunity, markers of systemic inflammation, preservation of cognitive function, progression of neurodegeneration, and the clinical course of influenza-effects which could be expected to lessen mortality and stave off frailty. Hence, greater cysteine availability may explain much of the favorable impact of higher protein intakes on mortality and frailty risk in the elderly, and joint supplementation with NAC and lipoic acid could be notably protective in the elderly, particularly in those who follow plant-based diets relatively low in protein. It is less clear whether the lower arginine intake associated with low-protein diets has an adverse impact on vascular health.

Effects of Glyprolines on DNA Synthesis and Free Radical Oxidation in Mouse Gastric Mucosa Under Physiological Conditions and During Therapy with Oral Non-Steroid Anti-Inflammatory Drugs

Studies by (3)H-thymidin autoradiography showed that injections of Pro-Gly-Pro and Arg-Gly-Pro peptides caused no changes in the DNA synthesis processes in the gastric mucosa. Both peptides induced a reduction of free radical oxidation activity, which was shown by chemiluminescence. Indomethacin induced lesions in the gastric mucosa, triggered oxidative stress, and reduced proliferative activity. Injection of Pro-Gly-Pro peptide before indomethacin corrected disorders in oxidative status and normalized DNA synthesis. Preinjection of Arg-Gly-Pro led to enlargement (by 4.6 times) of the focus of lesions in animals treated by indomethacin and augmented oxidative stress.

Effects of helium on inflammatory and oxidative stress-induced endothelial cell damage

Helium induces preconditioning in human endothelium protecting against postischemic endothelial dysfunction. Circulating endothelial microparticles are markers of endothelial dysfunction derived in response to injury. Another noble gas, xenon, protected human umbilical vein endothelial cells (HUVEC) against inflammatory stress in vitro. We hypothesised that helium protects the endothelium in vitro against inflammatory and oxidative stress. HUVEC were isolated from fresh umbilical cords and grown upon confluence. Cells were subjected to starving medium for 12h before the experiment and treated for either 3 × 5 min or 1 × 30 min with helium (5% CO2, 25% O2, 70% He) or control gas (5% CO2, 25% O2, 70% N2) in a specialised gas chamber. Subsequently, cells were stimulated with TNF-α (40 ng/ml for 24h or 10 ng/ml for 2h) or H2O2 (500 μM for 2h) or left untreated. Adhesion molecule expression was analysed using real-time quantitative polymerase chain reaction. Caspase-3 expression and viability of the cells was measured by flowcytometry. Microparticles were investigated by nanoparticle tracking analysis. Helium had no effect on adhesion molecule expression after TNF-α stimulation but in combination with oxidative stress decreased cell viability (68.9 ± 1.3% and 58 ± 1.9%) compared to control. Helium further increased TNF-α induced release of caspase-3 containing particles compared to TNF-α alone (6.4 × 10(6) ± 1.1 × 10(6) and 2.9 × 10(6) ± 0.7 × 10(6), respectively). Prolonged exposure of helium increased microparticle formation (2.4 × 10(9) ± 0.5 × 10(9)) compared to control (1.7 × 10(9) ± 0.2 × 10(9)). Summarized, helium increases inflammatory and oxidative stress-induced endothelial damage and is thus not biologically inert. A possible noxious effects on the cellular level causing alterations in microparticle formation both in number and content should be acknowledged.

Propofol attenuated acute kidney injury after orthotopic liver transplantation via inhibiting gap junction composed of connexin 32

BACKGROUND

Postliver transplantation acute kidney injury (AKI) severely affects patient survival, whereas the mechanism is unclear and effective therapy is lacking. The authors postulated that reperfusion induced enhancement of connexin32 (Cx32) gap junction plays a critical role in mediating postliver transplantation AKI and that pretreatment/precondition with the anesthetic propofol, known to inhibit gap junction, can confer effective protection.

METHODS

Male Sprague-Dawley rats underwent autologous orthotopic liver transplantation (AOLT) in the absence or presence of treatments with the selective Cx32 inhibitor, 2-aminoethoxydiphenyl borate or propofol (50 mg/kg) (n = 8 per group). Also, kidney tubular epithelial (NRK-52E) cells were subjected to hypoxia-reoxygenation and the function of Cx32 was manipulated by three distinct mechanisms: cell culture in different density; pretreatment with Cx32 inhibitors or enhancer; Cx32 gene knock-down (n = 4 to 5).

RESULTS

AOLT resulted in significant increases of renal Cx32 protein expression and gap junction, which were coincident with increases in oxidative stress and impairment in renal function and tissue injury as compared to sham group. Similarly, hypoxia-reoxygenation resulted in significant cellular injury manifested as reduced cell growth and increased lactate dehydrogenase release, which was significantly attenuated by Cx32 gene knock-down but exacerbated by Cx32 enhancement. Propofol inhibited Cx32 function and attenuated post-AOLT AKI. In NRK-52E cells, propofol reduced posthypoxic reactive oxygen species production and attenuated cellular injury, and the cellular protective effects of propofol were reinforced by Cx32 inhibition but cancelled by Cx32 enhancement.

CONCLUSION

Cx32 plays a critical role in AOLT-induced AKI and that inhibition of Cx32 function may represent a new and major mechanism whereby propofol reduces oxidative stress and subsequently attenuates post-AOLT AKI.

Aging aggravates nitrate-mediated ROS/RNS changes

Nitrates are the most frequently prescribed and utilized drugs worldwide. The elderly are a major population receiving nitrate therapy. Both nitrates and aging can increase in vivo reactive oxygen species (ROS) and reactive nitrogen species (RNS). To date, the effects of aging upon nitrate-induced ROS/RNS alteration are unknown. The present study tested the effects of aging upon nitrate-induced ROS/RNS alteration in vivo. 32 adults and 43 elderly unstable angina (UA) patients were subjected to 48 hours of isosorbide dinitrate intravenous injection (50 μg/minutes) in this clinical study. Blood samples were obtained at baseline and conclusion. Outcome measures of oxidative stress included plasma malondialdehyde (MDA), myeloperoxidase (MPO), and reduced glutathione (GSH). Plasma concentrations of NOx and nitrotyrosine served as markers of RNS. Because of the significant differences in basic clinical characters between adults and the elderly, we designed an additional experiment determining ROS/RNS stress in rat cardiac tissue. Additionally, rat thoracic aortic NOS activity served as a marker indicating endothelial function. Our study demonstrated that nitrate therapy significantly increased in vivo ROS/RNS stress in the elderly compared to adult patients, confirmed by animal data. Decreased NOS activity was observed in old rats. Taken together, the present study's data suggests a synergism between nitrate treatment and the aging process.

Nitroglycerine-induced nitrate tolerance compromises propofol protection of the endothelial cells against TNF-α: the role of PKC-β2 and NADPH oxidase

Continuous treatment with organic nitrates causes nitrate tolerance and endothelial dysfunction, which is involved with protein kinase C (PKC) signal pathway and NADPH oxidase activation. We determined whether chronic administration with nitroglycerine compromises the protective effects of propofol against tumor necrosis factor (TNF-) induced toxicity in endothelial cells by PKC-β₂ dependent NADPH oxidase activation. Primary cultured human umbilical vein endothelial cells were either treated or untreated with TNF-α (40 ng/mL) alone or in the presence of the specific PKC-β₂ inhibitor CGP53353 (1 μM)), nitroglycerine (10 μM), propofol (100 μM), propofol plus nitroglycerin, or CGP53353 plus nitroglycerine, respectively, for 24 hours. TNF-α increased the levels of superoxide, Nox (nitrate and nitrite), malondialdehyde, and nitrotyrosine production, accompanied by increased protein expression of p-PKC-β₂, gP91phox, and endothelial cell apoptosis, whereas all these changes were further enhanced by nitroglycerine. CGP53353 and propofol, respectively, reduced TNF-α induced oxidative stress and cell toxicity. CGP53353 completely prevented TNF-α induced oxidative stress and cell toxicity in the presence or absence of nitroglycerine, while the protective effects of propofol were neutralized by nitroglycerine. It is concluded that nitroglycerine comprises the protective effects of propofol against TNF-α stimulation in endothelial cells, primarily through PKC-β₂ dependent NADPH oxidase activation.

Changes in granulosa cells' gene expression associated with increased oocyte competence in bovine

One of the challenges in mammalian reproduction is to understand the basic physiology of oocyte quality. It is believed that the follicle status is linked to developmental competence of the enclosed oocyte. To explore the link between follicles and competence in cows, previous research at our laboratory has developed an ovarian stimulation protocol that increases and then decreases oocyte quality according to the timing of oocyte recovery post-FSH withdrawal (coasting). Using this protocol, we have obtained the granulosa cells associated with oocytes of different qualities at selected times of coasting. Transcriptome analysis was done with Embryogene microarray slides and validation was performed by real-time PCR. Results show that the major changes in gene expression occurred from 20 to 44  h of coasting, when oocyte quality increases. Secondly, among upregulated genes (20-44  h), 25% were extracellular molecules, highlighting potential granulosa signaling cascades. Principal component analysis identified two patterns: one resembling the competence profile and another associated with follicle growth and atresia. Additionally, three major functional changes were identified: (i) the end of follicle growth (BMPR1B, IGF2, and RELN), involving interactions with the extracellular matrix (TFPI2); angiogenesis (NRP1), including early hypoxia, and potentially oxidative stress (GFPT2, TF, and VNN1) and (ii) apoptosis (KCNJ8) followed by iii) inflammation (ANKRD1). This unique window of analysis indicates a progressive hypoxia during coasting mixed with an increase in apoptosis and inflammation. Potential signaling pathways leading to competence have been identified and will require downstream testing. This preliminary analysis supports the potential role of the follicular differentiation in oocyte quality both during competence increase and decrease phases.

Endothelial dysfunction: the early predictor of atherosclerosis

Since the discovery in the 1980s that nitric oxide (NO) is in fact the elusive endothelium-derived relaxing factor, it has become evident that NO is not only a major cardiovascular signalling molecule, but that changes in its bioavailability are crucial in determining whether atherosclerosis will develop or not. Sustained high levels of harmful circulating stimuli associated with cardiovascular risk factors such as diabetes mellitus elicit responses in endothelial cells that appear sequentially, namely endothelial cell activation and endothelial dysfunction (ED). ED, characterised by reduced NO bioavailability, is now recognised by many as an early, reversible precursor of atherosclerosis. The pathogenesis of ED is multifactorial; however, oxidative stress appears to be the common underlying cellular mechanism in the ensuing loss of vaso-active, inflammatory, haemostatic and redox homeostasis in the body's vascular system. The role of ED as a pathophysiological link between early endothelial cell changes associated with cardiovascular risk factors and the development of ischaemic heart disease is of importance to basic scientists and clinicians alike.

Risperidone enhances the vulnerability to stroke in hypertensive rats

BACKGROUND

Stroke is the second most common cause of death and a major cause of disability worldwide. Risperidone is an atypical antipsychotic drug that may increase the risk of stroke. The present work examined whether risperidone enhances the vulnerability to stroke in hypertensive rats and the potential mechanisms underlying such action.

METHODS

Experiment 1: Wistar-Kyoto (WKY) rats, spontaneously hypertensive rats (SHRs) and stroke-prone SHRs (SHR-SPs) were treated with risperidone (0.8 and 2.4 mg/kg/d) or vehicle for 30 consecutive days. Tissue damage in response to middle cerebral artery occlusion (MCAO) was measured microscopically. The activity of superoxide dismutase, glutathione peroxidase, the levels of malondialdehyde were also determined. Experiment 2: Survival data were recorded in SHR-SPs that received daily risperidone perpetually. Experiment 3: Effect of risperidone on interleukin-6 and tumor necrosis factor-α was examined in quiescent or LPS-activated cortical microglias from WKY rats. Experiment 4: Potential damage of risperidone exposure to neurons was examined in primary neuronal culture obtained from WKY rats, SHRs, and SHR-SPs.

RESULTS

Risperidone increased infarct areas upon MCAO in SHR-SPs and SHRs, but not in WKY rats. Survival time in SHR-SPs was shortened by risperidone. Apoptosis was augmented by risperidone through enhanced Bax. Risperidone also increased endothelial injury.

CONCLUSIONS

Risperidone enhances the vulnerability to stroke in hypertensive rats through increasing neuronal apoptosis and endothelial injury.

Iptakalim ameliorates monocrotaline-induced pulmonary arterial hypertension in rats

OBJECTIVES

We sought to investigate the experimental therapeutic effects and mechanisms of iptakalim, a new adenosine triphosphate (ATP)-sensitive potassium channel (K(ATP)) opener, on monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) and right heart ventricle remodeling in rats.

METHODS

Rats were injected with a single dose (50 mg/kg, ip) of MCT and given iptakalim (1, 3, and 9 mg/kg·per d, orally [po]) or saline for 28 days. The hemodynamic and morphometric parameters were assessed. Tissue and plasma samples were collected for histological and molecular analysis.

RESULTS

Treatment with iptakalim at daily oral doses of 1, 3, and 9 mg/kg from the day of MCT injection attenuated the high right ventricle systolic pressure (RVSP) and the increased weight ratio of right ventricle (RV) to left ventricle (LV) plus septum (S) (RV/(LV+S)), decreased heart rate (HR) and decreased mean arterial pressure (MAP), inhibited the RV myocardial tissue cell apoptosis, and the RV myocardial cell B-type natriuretic peptide (BNP) protein expression. Iptakalim also decreased the serum levels of nitric oxide (NO), endothelin 1 (ET-1), BNP, and the levels of NO, ET-1, and tumor necrosis factor-alpha (TNF-α) in the lung tissue.

CONCLUSION

These results indicate that iptakalim prevents MCT-induced PAH and RV remodeling and its mechanisms are related to inhibiting the pathological increases in NO, ET-1, BNP, and TNF-α, and Iptakalim may be a promising candidate for the treatment of PAH.

Mast cells activation contribute to small intestinal ischemia reperfusion induced acute lung injury in rats

BACKGROUND

Small intestinal ischemia-reperfusion (IIR) injury may lead to severe local and remote tissue injury, especially acute lung injury (ALI). Mast cell activation plays an important role in IIR injury. It is unknown whether IIR mediates lung injury via mast cell activation.

METHODS

Adult SD rats were randomized into sham operated group (S), sole IIR group (IIR) in which rats were subjected to 75 min of superior mesenteric artery occlusion followed by 4h reperfusion, or IIR being respectively treated with the mast cell stabilizer Cromolyn Sodium (IIR+CS group), with the tryptase antagonist Protamine (IIR+P group), with the histamine receptor antagonist Ketotifen (IIR+K group), or with the mast cell degranulator Compound 48/80 (IIR+CP group). The above agents were, respectively, administrated intravenously 5 min before reperfusion. At the end of experiment, lung tissue was obtained for histologic assessment and assays for protein expressions of tryptase and mast cell protease 7(MCP7). Pulmonary mast cell number and levels of histamine, TNF-α and IL-8 were quantified.

RESULTS

IIR resulted in lung injury evidenced as significant increases in lung histological scores (P<0.05 IIR vs. S), accompanied with concomitant increases of mast cell counts and elevations in TNF-α and IL-8 concentrations and reductions in histamine levels (all P<0.05 IIR vs. S). IIR also increased lung tissue tryptase and MCP7 protein expressions (all P<0.05, IIR vs. S). Cromolyn Sodium, Ketotifen and Protamine significantly reduced whilst Compound 48/80 aggravated IIR mediated ALI and the above biochemical changes (P<0.05).

CONCLUSIONS

Mast cells activation play a critical role in IIR mediated ALI.

Impairment and Differential Expression of PR3 and MPO on Peripheral Myelomonocytic Cells with Endothelial Properties in Granulomatosis with Polyangiitis

Background. Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are autoimmune-mediated diseases characterized by vasculitic inflammation of respiratory tract and kidneys. Clinical observations indicated a strong association between disease activity and serum levels of certain types of autoantibodies (antineutrophil cytoplasm antibodies with cytoplasmic [cANCA in GPA] or perinuclear [pAN CA in MPA] immunofluorescence). Pathologically, both diseases are characterized by severe microvascular endothelial cell damage. Early endothelial outgrowth cells (eEOCs) have been shown to be critically involved in neovascularization under both physiological and pathological condition. Objectives. The principal aims of our study were (i) to analyze the regenerative activity of the eEOC system and (ii) to determine mPR3 and MPO expression in myelo monocytic cells with endothelial characteristics in GPA and MPA patients. Methods. In 27 GPA and 10 MPA patients, regenerative activity blood-derived eEOCs were analyzed using a culture-forming assay. Flk-1⁺, CD133⁺/Flk-1⁺, mPR3⁺, and Flk-1⁺/mPR3⁺ myelomonocytic cells were quantified by FACS analysis. Serum levels of Angiopoietin-1 and TNF-α were measured by ELISA. Results. We found reduced eEOC regeneration, accompanied by lower serum levels of Angiopoietin-1 in GPA patients as compared to healthy controls. In addition, the total numbers of Flk-1⁺ myelomonocytic cells in the peripheral circulation were decreased. Membrane PR3 expression was significantly higher in total as well as in Flk-1⁺ myelomonocytic cells. Expression of MPO was not different between the groups. Conclusions. These data suggest impairment of the eEOC system and a possible role for PR3 in this process in patients suffering from GPA.

Involvement of nitrosative stress in experimental periodontitis in diabetic rats

AIM

Periodontal disease is highly prevalent and severe in diabetic patients, and is considered one of the diabetic complications. To elucidate how periodontitis progresses in diabetes, we examined an animal model of periodontitis in diabetic rats.

MATERIALS AND METHODS

Two weeks after the induction of diabetes by streptozotocin, surgical nylon thread was ligated around the cervical portion of the unilateral maxillary second molar to induce periodontitis. Periodontitis was evaluated 2 weeks after the ligation by gingival blood flow, mRNA expressions, Western blot analysis, histological examination and micro CT.

RESULTS

Ligation-induced severe periodontitis in the diabetic rats, which was apparently shown by the increase of TNF-α and iNOS mRNA expressions and inflammatory cell infiltration in the gingiva and alveolar bone loss. The number of nitrotyrosine, a footprint of nitrosative stress, -positive cells was significantly higher in the periodontitis of the diabetic rats compared with that in the normal rats. Western blot analysis confirmed that the nitrotyrosine was increased in the periodontitis of the diabetic rats.

CONCLUSIONS

This is the first study to confirm increased nitrosative stress due to periodontitis in diabetic rats. Nitrosative stress may play a crucial role in the exacerbation of periodontitis in diabetic patients.

Synergy of isoflurane preconditioning and propofol postconditioning reduces myocardial reperfusion injury in patients

Either isoflurane preconditioning or high-dose propofol treatment has been shown to attenuate myocardial IRI (ischaemia/reperfusion injury) in patients undergoing CABG (coronary artery bypass graft) surgery. It is unknown whether isoflurane and propofol may synergistically attenuate myocardial injury in patients. The present study investigated the efficacy of IsoPC (isoflurane preconditioning), propofol treatment (postconditioning) and their synergy in attenuating postischaemic myocardial injury in patients undergoing CABG surgery using CPB (cardiopulmonary bypass). Patients (n = 120) selected for CABG surgery were randomly assigned to one of four groups (n = 30 each). After induction, anaesthesia was maintained either with fentanyl and midazolam (control; group C); with propofol at 100 μg x kg(-1) of body weight x min(-1) before and during CPB followed by propofol at 60 μg x kg(-1) of body weight x min(-1) for 15 min after aortic declamping (group P); with isoflurane 1-1.5% end tidal throughout the surgery (group I) or with isoflurane 1-1.5% end tidal before CPB and switching to propofol at 100 μg x kg(-1) of body weight x min(-1) during CPB followed by propofol at 60 μg x kg(-1) of body weight x min(-1) for 15 min after aortic declamping (group IP, i.e. IsoPC plus propofol postconditioning). A joint isoflurane and propofol anaesthesia regimen synergistically reduced plasma levels of cTnI (cardiac troponin I) and CK-MB (creatine kinase MB) and f-FABP (heart-type fatty acid-binding protein) (all P < 0.05 compared with control, group P or group I) and facilitated postoperative myocardial functional recovery. During reperfusion, myocardial tissue eNOS (endothelial NO synthase) protein expression in group IP was significantly higher, whereas nitrotyrosine protein expression was lower than those in the control group. In conclusion, a joint isoflurane preconditioning and propofol anaesthesia regimen synergistically attenuated myocardial reperfusion injury in patients.

Nitric oxide suppression of cellular proliferation depends on cationic amino acid transporter activity in cytokine-stimulated pulmonary endothelial cells

Inducible nitric oxide (NO) synthase (iNOS) is a stress response protein upregulated in inflammatory conditions, and NO may suppress cellular proliferation. We hypothesized that preventing L-arginine (L-arg) uptake in endothelial cells would prevent lipopolysaccharide/tumor necrosis factor-α (LPS/TNF)-induced, NO-mediated suppression of cellular proliferation. Bovine pulmonary arterial endothelial cells (bPAEC) were treated with LPS/TNF or vehicle (control), and either 10 mM L-leucine [L-leu; a competitive inhibitor of L-arg uptake by the cationic amino acid transporter (CAT)] or its vehicle. In parallel experiments, iNOS or arginase II were overexpressed in bPAEC using an adenoviral vector (AdiNOS or AdArgII, respectively). LPS/TNF treatment increased the expression of iNOS, arginase II, CAT-1, and CAT-2 mRNA in bPAEC, resulting in greater NO and urea production than in control bPAEC, which was prevented by L-leu. LPS/TNF treatment resulted in fewer viable cells than in controls, and LPS/TNF-stimulated bPAEC treated with L-leu had more viable cells than LPS/TNF treatment alone. LPS/TNF treatment resulted in cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase expression, which was attenuated by L-leu. AdiNOS reduced viable cell number, and treatment of AdiNOS transfected bPAEC with L-leu preserved cell number. AdArgII increased viable cell number, and treatment of AdArgII transfected bPAEC with L-leu prevented the increase in cell number. These data demonstrate that iNOS expression in pulmonary endothelial cells leads to decreased cellular proliferation, which can be attenuated by preventing cellular L-arg uptake. We speculate that CAT activity may represent a novel therapeutic target in inflammatory lung diseases characterized by NO overproduction.

Ischemic postconditioning attenuates lung reperfusion injury and reduces systemic proinflammatory cytokine release via heme oxygenase 1

OBJECTIVE

Systemic inflammatory response following ischemia-reperfusion injury (IRI) to a specific organ may cause injuries in multiple remote organs. The emergence of ischemic postconditioning (IPO) provides a potential method for experimentally and clinically attenuating various types of organ postischemic injuries. We have shown that IPO can attenuate lung IRI by up-regulating the protein expression of heme oxygenase-1(HO-1). This study tested the hypothesis that IPO attenuates systemic inflammatory responses following lung IRI by activating HO-1.

METHODS

Anaesthetized and mechanically ventilated adult Sprague-Dawley rats were randomly assigned to one of the following groups (n = 8 each): the sham-operated control group, the ischemia-reperfusion (IR) group (40 min of left-lung ischemia and 120 min of reperfusion), the IPO group (three successive cycles of 30-s reperfusion per 30-s occlusion before restoring full perfusion), and the zinc protoporphyrin IX (ZnP) plus IPO group (ZnP, an inhibitor of HO-1, was injected intraperitoneally at 20 mg/kg 24 h prior to the experiment, and the rest of the procedures were similar to that of the IPO group). Lung injury was assessed by arterial blood gas analysis, wet-to-dry lung weight ratio and tissue histologic and biochemical changes. The lung tissue and plasma levels of lipid peroxidation were determined by measuring the contents of malondialdehyde (MDA) production. Protein expression of HO-1 was determined by Western blotting. Pulmonary neutrophil was counted. Lung tissue myeloperoxidase (MPO) activity as well as plasma levels of proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukines 6 and 8 (IL-6, IL-8) were determined by spectrophotography.

RESULTS

Lung ischemia-reperfusion led to severe lung pathologic morphologic changes and increased pulmonary MDA production, neutrophil count, and MPO activity and reduced arterial oxygen partial pressure (all P < 0.05 IR versus sham), accompanied with a compensatory increase in HO-1 protein and activity. Plasma levels of TNF-α, IL-6, and IL-8 were increased in the IR group (all P < 0.05 versus sham). IPO attenuated or prevented all the above changes, except that it further increased lung HO-1 activity. Treatment with ZnP abolished all the protective effects of postconditioning.

CONCLUSION

Postconditioning attenuated pulmonary neutrophil accumulation and activation and lung IRI and reduced systemic inflammatory responses by activating HO-1.