Increased NO Levels Research Articles

Tiger nut and walnut extracts modulate extracellular metabolism of ATP and adenosine through the NOS/cGMP/PKG signalling pathway in kidney slices

BackgroundTiger nut (Cyperus esculentus L.) and walnut (Tetracarpidium conophorum Müll. Arg.) have been reportedly used in the treatment of inflammatory diseases such as atherosclerosis, prevent heart attack and improve blood circulation, reduce serum cholesterol level as well as inhibit oxidation reactions. PurposeThis study investigated the effect of tiger nut and walnut hydro-alcoholic extracts on extracellular metabolism of ATP through the NOS/cGMP/PKG signaling pathway induced by Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) in kidney slices. MethodsThe plants were extracted for 24 h in 10 ml of 70% ethanol and 30% distilled water per gram milled material on a mechanical shaker and filtered using Whatman filter paper. The effect of the extracts on ecto-nucleotidases (NTPDase and 5′ nucleotidase) and adenosine deaminase activities, nitrites and nitrates levels (NO, markers of NO production) as well as lipid and protein oxidation reactions in kidney slices were evaluated. Also, the phenolic components of the nut samples were determined using High Performance Liquid Chromatography (HPLC). ResultsThe results revealed a protective effect of tiger nut and walnut on co-incubation with L-NAME of the enzyme activities, increased NO significantly (P < 0.05) when compared to the vehicle. L-NAME also increased the thiobabituric reactive substances but co-incubation with the extracts caused a significant reduction while protein oxidation across groups showed no significant difference when compared to the vehicle group. HPLC finger printing revealed the presence of quercetin and kaempferol as the most abundant phenolic compounds in tiger nut and walnut respectively. ConclusionTiger nut and walnut extracts showed a protective effect on L-NAME induced kidney slices by reducing the activities of NTPDase (ATP as substrate) and adenosine deaminase, increased NO levels as well as prevent oxidative damage. The effect observed may be attributed to the phenolic compounds present in both nuts as depicted by HPLC finger printing.

Water extract of Semecarpus parvifolia Thw. leaves inhibits cell proliferation and induces apoptosis on HEp-2 cells

BackgroundSemecarpus parvifolia Thw is used as an ingredient of poly herbal decoctions to treat cancer in traditional medicine. The present study aims to investigate the antiproliferative activity on HEp 2 cells by the water extract of S. parvifolia leaves and to evaluate potential mechanisms.MethodsThe plant extract was exposed to S. parvifolia for 24 hours and antiproliferative activity was quantified by Sulforhodamine B (SRB), 3-(4, 5-dimethythiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) and Lactate dehydrogenase (LDH) assays. Morphological changes were observed after staining cells with ethidium bromide/acridine orange (EB/AO) and Giemsa dye. Comet assay was performed to evaluate the DNA damage. The toxicity of the plant extract was determined by brine shrimp lethality assay.ResultsS. parvifolia leaves reduced the cell proliferation in a dose and time dependent manner. A two fold increase in NO level was observed at higher concentrations. Morphological changes characteristic to apoptosis were observed in light microscopy, Giemsa and EB/AO stained cells. Fragmented DNA further confirmed its capacity to induce apoptosis. No lethality was observed with brine shrimps.ConclusionThe results suggest that Semecarpus parvifolia Thw induces apoptosis in HEp-2 cells through a NO dependent pathway.

Involvement of NR and PM-NR in NO biosynthesis in cucumber plants subjected to salt stress

Nitrate reductase (NR) mainly reduces nitrate to nitrite. However, in certain conditions it can reduce nitrite to NO. In plants, a plasma membrane-associated form of NR (PM-NR) is present. It produces NO2− for nitrite NO/reductase (Ni-NOR), which can release NO into the apoplastic space. The effect of 50 mM NaCl on NO formation and the involvement of NR in NO biosynthesis were studied in cucumber seedling roots under salt stress. In salt-stressed roots, the amount of NO was higher than in control. The application of tungstate abolished the increase of NO level in stressed roots, indicating that NR was responsible for NO biosynthesis under the test conditions. The involvement of other molybdoenzymes was excluded using specific inhibitors. Furthermore, higher cNR and PM-NR activities were observed in NaCl-treated roots. The increase in NR activity was due to the stimulation of CsNR genes expression and posttranslational modifications, such as enzyme dephosphorylation. This was confirmed by Western blot analysis. Moreover, the increase of nitrite tissue level in short-term stressed roots and the nitrite/nitrate ratio, with a simultaneous decrease of nitrite reductase (NiR) activity, in both short- and long-term stressed roots, could promote the production of NO by NR in roots under salt stress.

Heat shock protein 70/nitric oxide effect on stretched tubular epithelial cells linked to WT-1 cytoprotection during neonatal obstructive nephropathy.

Mechanical stress is a key pathogenic driver of apoptosis in the tubular epithelium in obstructive nephropathy. Heat shock protein 70 (Hsp70) and Wilms' tumor (WT-1) have been proposed to represent linked downstream effectors of the cytoprotective properties of NO. In the present study, we sought to evaluate whether the cytoprotective effects of L-arginine in neonatal obstructive nephropathy may be associated with NO-dependent increases in WT-1 and Hsp70 expression. Neonatal Wistar-Kyoto rats were submitted to complete unilateral ureteral obstruction (UUO) and treated thereafter with vehicle, L-NAME or L-arginine by daily gavage for 14days to block or augment NO levels, respectively. Normal rat kidney epithelial cells by NRK-52E were exposed to mechanical stress in vitro in the presence or absence of L-NAME, L-arginine, sodium nitroprusside (SNP), L-arginine+SNP or L-arginine/L-NAME. Induction of apoptosis and the mRNA expression of WT-1 and Hsp70 genes were assessed. WT-1 and Hsp70 genes expression decreased in the presence of L-NAME and following UUO coincident with increased tubular apoptosis. L-arginine treatment increased NO levels, reduced apoptosis and restored expression levels of WT-1 and Hsp70 to control levels. L-arginine treatment in vitro reduced basal apoptotic rates and prevented apoptosis in response to mechanical strain, an effect enhanced by SNP co-incubation. L-NAME increased apoptosis and prevented the anti-apoptotic action of L-arginine. L-arginine treatment in experimental neonatal UUO reduces apoptosis coincident with restoration of WT-1 and Hsp70 expression levels and directly inhibits mechanical strain-induced apoptosis in an NO-dependent manner in vitro. This potentially implicates an NO-Hsp70-WT-1 axis in the cytoprotective effects of L-arginine.

Treatment with Standard and Low Dose of Conjugated Equine Estrogen Differentially Modulates Estrogen Receptor Expression and Response to Angiotensin II in Mesenteric Venular Bed of Surgically Postmenopausal Hypertensive Rats.

Standard hormone therapy for menopausal women [conjugated equine estrogen (CEE) 0.625 mg] has been associated with increased risk of venous thrombosis. Regimens containing a lower CEE dose (0.30 mg) have been used clinically to decrease side effects of supraphysiologic doses of estrogen. In this study, we determined the effects of standard (SD) and low dose (LD) of CEE on venular function in ovariectomized (OVX) spontaneously hypertensive rats (SHR). Contractions by angiotensin-II (Ang-II 10 μM) in perfused mesenteric venular bed were markedly increased in OVX (21.5 ± 1.3 mmHg) compared with Sham (14.7 ± 1.1 mm Hg, P < 0.05). CEE-SD did not modify Ang-II responses in OVX, whereas CEE-LD restored Ang-II contraction to Sham levels. Endothelial nitric oxide synthase (eNOS) inhibition by L-NAME increased Ang-II contractions in Sham and CEE-LD and was without effect in venules of OVX SHR and CEE-SD. In OVX there was decreased NO generation in association with diminished eNOS phosphorylation and increased O2- generation in the venular wall. CEE-LD reverted the deleterious effects of ovariectomy. Although CEE-SD augmented eNOS phosphorylation in OVX, it was unable to increase NO levels, probably owing to its inability to reduce O2- Distinct effects by CEE-SD and CEE-LD parallel the differential modulation of Ang-II and estrogen receptors. Compared with Sham, CEE-LD increases Ang II receptor type 2, whereas CEE-SD modified ERβ expression in the venous bed. Interestingly, both CEE doses increased G protein-coupled estrogen receptor in OVX. Our data suggest that estrogen dose is an important factor for venous function. Although CEE-LD reversed deleterious effects of OVX, CEE-SD showed null effects despite its ability to increase eNOS activity.

Class side effects: decreased pressure in the lower oesophageal and the pyloric sphincters after the administration of dopamine antagonists, neuroleptics, anti-emetics, L-NAME, pentadecapeptide BPC 157 and L-arginine.

The ulcerogenic potential of dopamine antagonists and L-NAME in rats provides unresolved issues of anti-emetic neuroleptic application in both patients and experimental studies. Therefore, in a 1-week study, we examined the pressures within the lower oesophageal and the pyloric sphincters in rats [assessed manometrically (cm H2O)] after dopamine neuroleptics/prokinetics, L-NAME, L-arginine and stable gastric pentadecapeptide BPC 157 were administered alone and/or in combination. Medication (/kg) was given once daily intraperitoneally throughout the 7days, with the last dose at 24h before pressure assessment. Given as individual agents to healthy rats, all dopamine antagonists (central [haloperidol (6.25mg, 16mg, 25mg), fluphenazine (5mg), levomepromazine (50mg), chlorpromazine (10mg), quetiapine (10mg), olanzapine (5mg), clozapine (100mg), sulpiride (160mg), metoclopramide (25mg)) and peripheral(domperidone (10mg)], L-NAME (5mg) and L-arginine (100mg) decreased the pressure within both sphincters. As a common effect, this decreased pressure was rescued, dose-dependently, by BPC 157 (10µg, 10ng) (also note that L-arginine and L-NAME given together antagonized each other's responses). With haloperidol, L-NAME worsened both the lower oesophageal and the pyloric sphincter pressure, while L-arginine ameliorated lower oesophageal sphincter but not pyloric sphincter pressure, and antagonized L-NAME effect. With domperidone, L-arginine originally had no effect, while L-NAME worsened pyloric sphincter pressure. This effect was opposed by L-arginine. All these effects were further reversed towards a stronger beneficial effect, close to normal pressure values, by the addition of BPC 157. In addition, NO level was determined in plasma, sphincters and brain tissue. Thiobarbituric acid reactive substances (TBARS) were also assessed. Haloperidol increased NO levels (in both sphincters, the plasma and brain), consistently producing increased TBARS levels in the plasma, sphincters and brain tissues. These effects were all counteracted by BPC 157 administration. In conclusion, we revealed that BPC 157 counteracts the anti-emetic neuroleptic class side effect of decreased pressure in sphincters and the dopamine/NO-system/BPC 157 relationship.

Asthma management among allergists in Italy: results from a survey

BackgroundIn Europe more than 50% of asthmatic treated patients have not well-controlled asthma. Asthma affects about 2.5 million of patients in Italy.Aims and objectivesThe present survey aims at investigating how Italian allergists approach asthmatic patients, in order to highlight pitfalls and unmet needs concerning real-life asthma management.MethodsAn anonymous 16 item web questionnaire was available (April–October 2015) to all allergists who visited the web site of SIAAIC (Società Italiana di Allergologia, Asma Immunologia Clinica). Those who wished to give their contribution had the opportunity to answer about epidemiology, risk factors, treatment approaches, and adherence to therapy.ResultsOne hundred and seventy four allergists answered the survey. 54% of them reported up to 10 patient visits per week and 35.3% between 10 and 30. The most frequent reasons of follow up visits are routine check-up (56.5% of allergists), and worsening of symptoms (41% of allergists). Nocturnal apnoeas, gastro-esophageal reflux and obesity are the most important comorbidities/risk factors of poorly controlled asthma. Bronchial hyper-responsiveness, increased NO levels and reduced exercise tolerance are the most important indicators of asthma severity. Concerning therapy, ICS combined with LABA is the treatment of choice suitable for the majority of patients. A rapid onset of action and a flexible ICS dosage are indicated as the optimal characteristics for achieving the therapeutic goals. Poor adherence to therapy is an important reason for symptom worsening for the majority of allergists. Complex dosage regimens and economic aspects are considered the most important factors impacting on adherence.ConclusionsAllergists are involved in the management of asthma, regularly seeing their patients. Co-morbidities are frequent in asthmatic patients and may impact negatively on disease control, thus identifying patients who need a more careful and strict monitoring. Airway hyper-responsiveness to methacholine challenge test and nitric oxide are considered important indicators of asthma severity. The combination of LABA and inhaled steroids is considered the treatment of choice for most asthmatic patients, in keeping with broad evidence indicating that the combination therapy is more effective and rapid in gaining asthma control than inhaled corticosteroids alone. Adherence to medication regimens is considered of essence to achieve the therapeutic goals.

НАПРАВЛЕНИЯ ЗАЩИТНОГО ДЕЙСТВИЯ БИФЕРМЕНТНОГО КОНЪЮГАТА АНТИОКСИДАНТНЫХ БИОКАТАЛИЗАТОРОВ IN VIVO

Endotoxin shock in rats led to intravenous bolus of bacterial lipopolysaccharide (LPS) was accompanied by oxidative stress and increase of NO level in livers, lungs, kidneys, hearts of animals. The intravenous administration of bienzyme superoxide dismutase - chondroitin sulphate - catalase conjugate (SOD-CHS-CAT) showed its anti-endotoxemia action in rats at preventive (before initiation of injury) and therapeutic (after start of injury) application during cytokine phase of injury and influence on further stages of the damage. The injection of antioxidant SOD-CHS-CAT conjugate in a therapeutic regime did not demonstrate significant alterations of No level in livers, lungs, kidneys, hearts of rats (as compared to indices of the rat group with LpS action only) and displayed protective action on the kidney function by altered urea and creatinine in blood. The therapeutic effect of SOD-CHS-CAT was demonstrated by increase in organism viability. The effects of intravenous injection of SOD-CHS-CAT in a rat model of endotoxin shock showed a variety in the activity of this conjugate in addition to prevention of NO conversion in peroxynitrite upon interaction with O 2 superoxide radical. The results of accelerated normalization of arterial blood pressure and heart rate, a significant decrease in rat lethality because of using SOD-CHS-CAT conjugate indicate the importance of the determination of action mechanism of the cardiovascular injury models associated with other vasoactive agents besides NO. The further research of vascular damage pathogenesis and evaluation of its role in oxidative stress (time and place) are of paramount importance.

Plasma membrane calcium ATPase 4 (PMCA4) co-ordinates calcium and nitric oxide signaling in regulating murine sperm functional activity.

Reduced sperm motility (asthenospermia) and resulting infertility arise from deletion of the Plasma Membrane Ca2+ -ATPase 4 (Pmca4) gene which encodes the highly conserved Ca2+ efflux pump, PMCA4. This is the major Ca2+ clearance protein in murine sperm. Since the mechanism underlying asthenospermia in PMCA4's absence or reduced activity is unknown, we investigated if sperm PMCA4 negatively regulates nitric oxide synthases (NOSs) and when absent NO, peroxynitrite, and oxidative stress levels are increased. Using co-immunoprecipitation (Co-IP) and Fluorescence Resonance Energy Transfer (FRET), we show an association of PMCA4 with the NOSs in elevated cytosolic [Ca2+ ] in capacitated and Ca2+ ionophore-treated sperm and with neuronal (nNOS) at basal [Ca2+ ] (ucapacitated sperm). FRET efficiencies for PMCA4-eNOS were 35% and 23% in capacitated and uncapacitated sperm, significantly (p < 0.01) different, with the molecules being <10 nm apart. For PMCA4-nNOS, this interaction was seen only for capacitated sperm where FRET efficiency was 24%, significantly (p < 0.05) higher than in uncapacitated sperm (6%). PMCA4 and the NOSs were identified as interacting partners in a quaternary complex that includes Caveolin1, which co-immunoprecipitated with eNOS in a Ca2+ -dependent manner. In Pmca4-/- sperm NOS activity was elevated twofold in capacitated/uncapacitated sperm (vs. wild-type), accompanied by a twofold increase in peroxynitrite levels and significantly (p < 0.001) increased numbers of apoptotic germ cells. The data support a quaternary complex model in which PMCA4 co-ordinates Ca2+ and NO signaling to maintain motility, with increased NO levels resulting in asthenospermia in Pmca4-/- males. They suggest the involvement of PMCA4 mutations in human asthenospermia, with diagnostic relevance.

Abstract WP431: Functionally Distinct Neuronal Nitric Oxide Synthase Expressed in the Brain Microvascular Endothelial Cells Mediates Anoxic-injury to Blood-Brain Barrier

Objective: Mice with genetic deletion of endothelial (eNOS; protective) and neuronal (nNOS; detrimental) nitric oxide synthase isoforms exhibit dramatically opposite consequences of ischemic brain injury. nNOS has been identified recently in endothelial cells, however, its functional significance is unclear. Our objective was to identify nNOS and characterize its functional role in primary brain microvascular endothelial cells (MECs). Methods and Results: MECs from humans (hMECs), rats (rMECs), and mice (mMECs) along with cultured primary rat cortical neurons were used. In addition, rat brain microvessels were freshly isolated. Transendothelial electrical resistance (TEER) measurements of monolayers of hMECs cultured in transwells were used to quantitate in vitro blood-brain barrier (BBB) integrity. Immunocytochemistry identified von Willebrand factor, eNOS, and nNOS in MECs but stained negative for glial (GFAP) and neuronal (Neu1) markers. PCR studies confirmed the expression of eNOS and nNOS mRNA in MECs and microvessels. We utilized electron spin resonance spectrometry to measure reactive oxygen species (ROS) (1-Hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine; CMH) and NO (colloid Fe(DETC)2). Inhibition of nNOS (N-ω-Propyl-L-arginine and ARL-17477) reduced ROS but increased NO levels in MECs and rat brain microvessels. In contrast, eNOS inhibitor (L-N5-(1-Iminoethyl)ornithine) increased ROS but reduced NO levels. Inhibition of nNOS in neurons, similarly increased ROS and decreased NO levels. siRNA targeting rat nNOS in rMECs was able to knockdown nNOS mRNA as well as ROS levels. BBB studies of hMECs treated with NOS inhibitors followed by oxygen-glucose deprivation (OGD) revealed that nNOS inhibition increased TEER at baseline and promoted TEER recovery following OGD. In contrast, eNOS inhibition had no effect on TEER at baseline but weakly albeit transiently helps in the post-OGD recovery of BBB function. Conclusions: Thus, we identified a constitutively active nNOS in MECs that is functionally distinct from the nNOS isoform expressed in neurons and eNOS. In addition, nNOS inhibition enhances the BBB integrity and affords protection against anoxic-injury induced impairment of BBB function.

Nitric oxide participates in IFN-gamma-induced HUVECs hyperpermeability.

The endothelial barrier function is tightly controlled by a broad range of signaling cascades including nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway. It has been proposed that disturbances in NO and cGMP production could interfere with proper endothelial barrier function. In this study, we assessed the effect of interferon-gamma (IFN-gamma), a pro-inflammatory cytokine, on NO and cGMP levels and examined the mechanisms by which NO and cGMP regulate the IFN-gamma-mediated HUVECs hyperpermeability. The flux of fluorescein isothiocyanate-labeled dextran across cell monolayers was used to study the permeability of endothelial cells. Here, we found that IFN-gamma significantly attenuated basal NO concentration and the increased NO levels supplied by a NO donor, sodium nitroprusside (SNP). Besides, application of IFN-gamma also significantly attenuated both the basal cGMP concentration and the increased cGMP production donated by a cell permeable cGMP analogue, 8-bromo-cyclic GMP (8-Br-cGMP). In addition, exposure of the cell monolayer to IFN-gamma significantly increased HUVECs basal permeability. However, L-NAME pretreatment did not suppress IFN-gamma-induced HUVECs hyperpermeability. L-NAME pretreatment followed by SNP or SNP pretreatment partially reduced IFN-gamma-induced HUVECs hyperpermeability. Pretreatment with a guanylate cyclase inhibitor, 6-anilino-5,8-quinolinedione (LY83583), led to a further increase in IFN-gamma-induced HUVECs hyperpermeability. The findings suggest that the mechanism underlying IFN-gamma-induced increased HUVECs permeability is partly related to the inhibition of NO production.

Lectins from Synadenium carinatum (ScLL) and Artocarpus heterophyllus (ArtinM) Are Able to Induce Beneficial Immunomodulatory Effects in a Murine Model for Treatment of Toxoplasma gondii Infection.

Infection by Toxoplasma gondii affects around one-third of world population and the treatment for patients presenting toxoplasmosis clinically manifested disease is mainly based by a combination of sulfadiazine, pyrimethamine, and folinic acid. However, this therapeutic protocol is significantly toxic, causing relevant dose-related bone marrow damage. Thus, it is necessary to improve new approaches to investigate the usefulness of more effective and non-toxic agents for treatment of patients with toxoplasmosis. It has been described that lectins from plants can control parasite infections, when used as immunological adjuvants in vaccination procedures. This type of lectins, such as ArtinM and ScLL is able to induce immunostimulatory activities, including efficient immune response against parasites. The present study aimed to evaluate the potential immunostimulatory effect of ScLL and ArtinM for treatment of T. gondii infection during acute phase, considering that there is no study in the literature accomplishing this issue. For this purpose, bone marrow-derived macrophages (BMDMs) were treated with different concentrations from each lectin to determine the maximum concentration without or with lowest cytotoxic effect. After, it was also measured the cytokine levels produced by these cells when stimulated by the selected concentrations of lectins. We found that ScLL showed high capacity to induce of pro-inflammatory cytokine production, while ArtinM was able to induce especially an anti-inflammatory cytokines production. Furthermore, both lectins were able to increase NO levels. Next, we evaluated the treatment effect of ScLL and ArtinM in C57BL/6 mice infected by ME49 strain from T. gondii. The animals were infected and treated with ScLL, ArtinM, ArtinM plus ScLL, or sulfadiazine, and the following parameters analyzed: Cytokines production, brain parasite burden and survival rates. Our results demonstrated that the ScLL or ScLL plus ArtinM treatment induced production of pro-inflammatory and anti-inflammatory cytokines, showing differential but complementary profiles. Moreover, when compared with non-treated mice, the parasite burden was significantly lower and survival rates higher in mice treated with ScLL or ScLL plus ArtinM, similarly with sulfadiazine treatment. In conclusion, the results demonstrated the suitable potential immunotherapeutic effect of ScLL and ArtinM lectins to control acute toxoplasmosis in this experimental murine model.

Overexpression of Glutamate Decarboxylase in Mesenchymal Stem Cells Enhances Their Immunosuppressive Properties and Increases GABA and Nitric Oxide Levels.

The neurotransmitter GABA has been recently identified as a potent immunosuppressive agent that targets both innate and adaptive immune systems and prevents disease progression of several autoimmunity models. Mesenchymal stem cells (MSCs) are self-renewing progenitor cells that differentiate into various cell types under specific conditions, including neurons. In addition, MSC possess strong immunosuppressive capabilities. Upon cytokine priming, undifferentiated MSC suppress T-cell proliferation via cell-to-cell contact mechanisms and the secretion of soluble factors like nitric oxide, prostaglandin E2 and IDO. Although MSC and MSC-derived neuron-like cells express some GABAergic markers in vitro, the role for GABAergic signaling in MSC-mediated immunosuppression remains completely unexplored. Here, we demonstrate that pro-inflammatory cytokines selectively regulate GAD-67 expression in murine bone marrow-MSC. However, expression of GAD-65 is required for maximal GABA release by MSC. Gain of function experiments using GAD-67 and GAD-65 co-expression demonstrates that GAD increases immunosuppressive function in the absence of pro-inflammatory licensing. Moreover, GAD expression in MSC evokes an increase in both GABA and NO levels in the supernatants of co-cultured MSC with activated splenocytes. Notably, the increase in NO levels by GAD expression was not observed in cultures of isolated MSC expressing GAD, suggesting crosstalk between these two pathways in the setting of immunosuppression. These results indicate that GAD expression increases MSC-mediated immunosuppression via secretion of immunosuppressive agents. Our findings may help reconsider GABAergic activation in MSC for immunological disorders.

Prolonged insulin treatment sensitizes apoptosis pathways in pancreatic β cells.

Insulin resistance results from impaired insulin signaling in target tissues that leads to increased levels of insulin required to control plasma glucose levels. The cycle of hyperglycemia and hyperinsulinemia eventually leads to pancreatic cell deterioration and death by a mechanism that is yet unclear. Insulin induces ROS formation in several cell types. Furthermore, death of pancreatic cells induced by oxidative stress could be potentiated by insulin. Here, we investigated the mechanism underlying this phenomenon. Experiments were done on pancreatic cell lines (Min-6, RINm, INS-1), isolated mouse and human islets, and on cell lines derived from nonpancreatic sources. Insulin (100nM) for 24h selectively increased the production of ROS in pancreatic cells and isolated pancreatic islets, but only slightly affected the expression of antioxidant enzymes. This was accompanied by a time- and dose-dependent decrease in cellular reducing power of pancreatic cells induced by insulin and altered expression of several ER stress response elements including a significant increase in Trb3 and a slight increase in iNos The effect on iNos did not increase NO levels. Insulin also potentiated the decrease in cellular reducing power induced by H2O2 but not cytokines. Insulin decreased the expression of MCL-1, an antiapoptotic protein of the BCL family, and induced a modest yet significant increase in caspase 3/7 activity. In accord with these findings, inhibition of caspase activity eliminated the ability of insulin to increase cell death. We conclude that prolonged elevated levels of insulin may prime apoptosis and cell death-inducing mechanisms as a result of oxidative stress in pancreatic cells.

Linking mitochondrial dysfunction, metabolic syndrome and stress signaling in Neurodegeneration

Mounting evidence suggests a link between metabolic syndrome (MetS) such as diabetes, obesity, non-alcoholic fatty liver disease in the progression of Alzheimer's disease (AD), Parkinson's disease (PD) and other neurodegenerative diseases (NDDs). For instance, accumulated Aβ oligomer is enhancing neuronal Ca2+ release and neural NO where increased NO level in the brain through post translational modification is modulating the level of insulin production. It has been further confirmed that irrespective of origin; brain insulin resistance triggers a cascade of the neurodegeneration phenomenon which can be aggravated by free reactive oxygen species burden, ER stress, metabolic dysfunction, neuorinflammation, reduced cell survival and altered lipid metabolism. Moreover, several studies confirmed that MetS and diabetic sharing common mechanisms in the progression of AD and NDDs where mitochondrial dynamics playing a critical role. Any mutation in mitochondrial DNA, exposure of environmental toxin, high-calorie intake, homeostasis imbalance, glucolipotoxicity is causative factors for mitochondrial dysfunction. These cumulative pleiotropic burdens in mitochondria leads to insulin resistance, increased ROS production; enhanced stress-related enzymes that is directly linked MetS and diabetes in neurodegeneration. Since, the linkup mechanism between mitochondrial dysfunction and disease phenomenon of both MetS and NDDs is quite intriguing, therefore, it is pertinent for the researchers to identify and implement the therapeutic interventions for targeting MetS and NDDs. Herein, we elucidated the pertinent role of MetS induced mitochondrial dysfunction in neurons and their consequences in NDDs. Further, therapeutic potential of well-known biomolecules and chaperones to target altered mitochondria has been comprehensively documented. This article is part of a Special Issue entitled: Oxidative Stress and Mitochondrial Quality in Diabetes/Obesity and Critical Illness Spectrum of Diseases - edited by P. Hemachandra Reddy.

Endothelium protecting properties of taurin in chronic heart failure with type 2 diabetes

High prevalence of chronic heart failure (CHF) and type 2 diabetes (DM2), poor prognosis and low life quality determine the aim for optimum treatment strategy invention. Cornerstone of the treatment in this category of patients is correction of endothelial dysfunction and metabolism disorders that underlie development and progression of CHF and DM2: lipid- and glucose toxicity, insulin resistance (IR). Aim. To study the effects of taurin treatment as part of combination therapy for CHF with DM2, taking its influence on endothelial dysfunction. Material and methods. Totally, 60 patients included, after myocardial infarction (MI) lasting 6-12 months, with CHF I-III functional class and comorbid DM2. They were selected to 2 groups: 1st (controls) — patients receiving CHF treatment in postinfarction period and oral glucose lowering drugs, and 2nd (experimental) — patients also taking taurin 500 mg b.i.d. together with CHF and DM2 treatment. Assessment included 6-minute walking test, measurement of brain natriuretic peptide (NT-proBNP) in blood, echocardiography, vascular components of endothelium functioning, plasmatic factors of endothelial function (NO metabolites concentration and endotheline-1 in serum), glucose level, insulin with IR-index, glycosilated hemoglobine, total cholesterol, low density and high density lipoproteides, triglycerides. Results. It is found, that taurin shows endothelium protecting properties when used as part of combination therapy for CHF and DM2. These properties were noted on microcirculatory (significant in spastic pattern of disorder) level and in elastic arteries. While taking taurin, there was statistically significant increase of NO level in blood and decrease of endotheline-1. Conclusion. Positive endothelium protecting properties of taurin as part of combination therapy of CHF with DM2 were followed by significant decrease of CHF severity by NT-proBNP levels dynamics, and significant hypolipidemic effect, decrease of IR.

Regulatory parameters of the lung immune response during the early phase of experimental trichinellosis

Parasitic infection caused by Trichinella spiralis provokes an early stimulation of the mucosal immune system which causes an allergic inflammatory response in the lungs. The present work was intended to characterize the kinetics of emergence of regulatory parameters in Wistar rat lungs during this early inflammatory response, between days 0 and 13p.i. The presence of regulatory cells such as regulatory T cells (Tregs) and alternatively activated macrophages (AAM) was analyzed in lung cell suspensions. Moreover, a regulatory cytokine (TGF-β) was studied in lung tissue extracts. Considering that newborn larvae (NBL) travel along the pulmonary microvasculature, the ability of this parasite stage to modulate the activation of lung macrophages was evaluated. For this purpose, lung macrophages from non-infected or infected rats (day 6p.i.) were cultured with live or dead NBL. Arginase activity (characteristic of AAM) and nitric oxide (NO produced by iNOS, characteristic of classical activated macrophages) were measured after 48h. Our results revealed a significant increase in the percentage of Tregs on days 6 and 13p.i., arginase activity on day 13p.i. and TGF-β levels on days 6 and 13p.i. Lung macrophages from non-infected rats cultured with live NBL showed a significant increase in arginase activity and NO levels. Live and dead NBL induced a significant increase in arginase activity in lung macrophages from infected rats. Only live NBL significantly increased NO levels in these macrophages. The present work demonstrates for the first time, the emergence of regulatory parameters in the early lung immune response during T. spiralis infection. The immumodulatory properties exerted by NBL during its passage through this organ could be the cause of such regulation. Moreover, we have shown the ability of NBL to activate macrophages from the lung parenchyma by the classical and alternative pathways.

Wen-Xin Decoction ameliorates vascular endothelium dysfunction via the PI3K/AKT/eNOS pathway in experimental atherosclerosis in rats.

BackgroundNitric oxide (NO) is the most powerful vasodilator that inhibits leukocyte adhesion, platelet aggregation, and vascular smooth muscle cell proliferation. However, excessive NO can cause lipid peroxidation and direct endothelial cell damage. Therefore, investigation of the role of NO in artherosclerosis development is important. Wen-Xin Decoction (WXD) has been shown to relieve myocardial ischemia reperfusion injury and prevent leukocyte adhesion and invasion; in addition, it can accelerate angiogenesis and prevent platelet activation and aggregation. In this study, we focused on the NO pathway to further clarify the protective effects of WXD on the vascular endothelium in rat models of artherosclerosis.MethodsWistar rats were randomly divided into a normal group (n = 10) and a model group (n = 75). Rat models of atherosclerosis were generated by intraperitoneal vitamin D3 (3 months) injections and administration of a high-fat diet (3 months with vitamin D3 and 2 months alone). The model rats were randomly divided into five groups (n = 15 each): model (saline), atorvastatin (4.8 mg/kg/d atorvastatin), high-dose WXD (9 g/kg/d), medium-dose WXD (4.5 g/kg/d), and low-dose WXD (2.25 g/kg/d) groups. Each group received continuous drug or saline administration (suspended liquid gavage) for 30 days, following which all animals were sacrificed. The ultrastructure and histopathological changes of vascular endothelial cells and the expression of PI3K/AKT/eNOS and iNOS in the thoracic aorta tissue were analyzed.ResultsWXD increased NO levels, modulated the NO/ET-1 ratio, and promoted repair of the injured vascular endothelium in a dose-dependent manner. At a high dose, WXD regulated the NO/ET-1 ratio as effectively as atorvastatin; furthermore, it increased NO levels within the physiological range to prevent endothelial damage caused by excessive NO expression. Real-time polymerase chain reaction and Western blot analysis showed that WXD significantly upregulated the mRNA and protein expressions of PI3K, AKT, and eNOS mRNA and significantly increased AKT and eNOS phosphorylation.ConclusionsOur results suggest that WXD protects and maintains the integrity of the vascular endothelium by activating the PI3K/AKT/eNOS pathway, decreasing iNOS expression, and promoting the release of physiological NO levels.

Effects of olanzapine on LPS-induced inflammation in rat primary glia cells.

Olanzapine (OLZ) is an atypical antipsychotic drug that also has mood-stabilizing effects. The mechanism of action of OLZ is not fully understood. Accumulating data suggest that inflammation plays a role in the pathophysiology of mental disorders and that psychotropic drugs exhibit some anti-inflammatory properties. This study was undertaken to examine the effects of OLZ on LPS-induced inflammation in rat primary glia cells. Glia cells were extracted from newborn rat brains. OLZ (1 or 50 µM) was added to culture medium at 6 or 72 h before addition of LPS for another 18 h, and levels of IL-10, prostaglandin (PG) E2, NO and TNF-α, and expression of cyclo-oxygensase (COX)-2 and inducible NO synthase (iNOS) were determined. Treatment with 50 µM OLZ (but not 1 µM) significantly decreased LPS-induced secretion of IL-10, PGE2 and TNF-α. In contrast, 50 µM OLZ significantly increased NO levels. OLZ did not alter the expression of COX-2 or iNOS in LPS-treated cells. These results suggest that OLZ differently affects the secretion of inflammatory mediators. Most of the significant effects of OLZ were obtained when 50 µM was used, which is a high and probably therapeutically irrelevant concentration. Therefore, under the conditions used in the present study OLZ seemed to lack a potent anti-inflammatory effect.

Enhanced hypoxic tolerance by Seabuckthorn is due to upregulation of HIF-1α and attenuation of ER stress

An imbalance in the redox homeostasis causes activation of multifaceted signaling responses which may be protective or deleterious. Amelioration of oxidative stress is one of the major modes of action of herbal supplements like Seabuckthorn (SBT). While the antioxidant potential of SBT is known, investigations into its effect on stress inducible signaling cascades are in progress. Here, we examine the impact of SBT on hypoxic tolerance and the mechanism behind its cardioprotective action. The efficacy of SBT was evaluated using the onset of gasping time (GT) at an altitude of 9754m as the indicator for hypoxic tolerance. SBT led to a 100% increase in GT and curtailed hypoxia induced cardiac damage and free radical production. SBT upregulated HIF-1α and led to a two-fold increase in HO-1. A 100% increase in NO levels was observed. SBT reduced protein carbonylation and enhanced HSP70 levels. A statistically significant decline was seen in the markers of ER stress, GRP78, PERK and CHOP. SBT potentiated anti-inflammatory effects and downregulated NF-κB and TNF-α. Our study provides a novel insight into the mechanism behind the pro-survival effects of SBT against hypoxia, highlighting the cross talk between key adaptive responses mediated by HIF-1α and ER stress.