Inducible NO Research Articles

Ранні маркери гострої доксорубіциніндукованої кардіотоксичності та механізми її розвитку

Arrhythmias and congestive heart failure, which pose the greatest risk of toxic cardiomyopathy, are the clinically limiting side effects of doxorubicin, the main highly active anticancer agent. The difficulty of early diagnosis of cardiomyopathy and timely detection of cardiac dysfunction associated with chemotherapy remains a significant medical problem. The aim of our study was to identify early signs of acute doxorubicin-induced cardiotoxicity in adult rats by assessing ECG changes and biochemical parameters. Acute cardiotoxicity was modelled by short-term intraperitoneal injection of doxorubicin at a total dose of 15 mg/kg. On the 5th day of the experiment, visual fluctuations of electrocardiogram (ECG) waveforms, duration and amplitude of the main teeth and intervals, as well as heart rate (HR) in the control and experimental groups of rats were studied to determine early ECG signs of cardiotoxicity. The most significant ECG changes were a doubling of the QT interval duration and significant ST-segment elevation in the rats of the experimental group. In experiments on isolated aortic rings, we demonstrated doxorubicin-induced disruption of both vascular relaxation and contraction mechanisms. The endothelium-dependent relaxation of vascular preparations of animals after administration of doxorubicin to acetylcholine (0.1 μmol/l) was 47% less than in the control group. The vascular ring contractions in rats under the influence of norepinephrine (10 μmol/l) were 59% lower than in control rats. After doxorubicin administration, oxidative stress developed against the background of cardiovascular disorders. Thus, the content of diene conjugates and malondialdehyde increased by 4 and 2.5 times, respectively. At the same time, in isolated cardiac mitochondria, the activity of inducible NO synthase increased 3.7-fold with a simultaneous significant 4.8-fold inhibition of constitutive NO synthase. An increase in the content of acute-phase biochemical parameters that are markers of damage, namely alanine aminotransferase (ALT), aspartate aminotransferase (AST) and creatine phosphokinase myocardial fraction (CPK MB) by 2.2, 1.4 and 1.5 times, respectively, was detected. Thus, the acute cardiotoxic effect of doxorubicin results in changes in the systolic-diastolic function of the left ventricle of the heart and its conduction, automaticity and contractility, as well as impaired relaxation and contraction of isolated preparations of the aorta against the background of increased activity of inducible and decreased constitutive NO synthesis, accompanied by oxidative stress and increased content of biochemical markers of myocardial damage.

Contractive function of mesenteric lymph nodes in obese rats

Over the past 50 years, the prevalence of obesity around the world has increased several times and has become a pandemic. The effect of obesity on the lymphatic system, which plays a key role in the regulation of fluid homeostasis, immune cell migration, antigen presentation, and resolution of inflammatory responses, is poorly understood, and there is no data on the contractile activity of the lymph nodes in obesity. The purpose of the research was to investigate the parameters and mechanisms of dysfunction of the contractile function of the mesenteric lymph nodes of rats in obesity caused by the feeding with the high-fat diet (HFD). Material and methods. The study was conducted on 50 male Sprague-Dawley rats. Rats aged 6 weeks were randomly divided into groups: a control group (n=10) fed a standard diet and a group of rats (n=40) kept on HFD (60% fat content by calorie value). Rats received food and water ad libitum for 16 weeks. Before the end of the experiment, four groups of HFD rats were formed: obesity resistant animals (HFD-OR, n=11), without additional interventions (HFD, n=10), rats which were administered dexamethasone three days before the study (HFD+Dexa, n=9), HFD followed by 8-week diet restriction (HFD+DR, n=9). At the end of the experiment, mesenteric lymph nodes (LNs) were taken from rats under anesthesia and their contractile function was studied in a myograph using 1400W, dynastat and Tempol. Results. LNs of control rats had a high level of tone and generated spontaneous high-amplitude phasic contractions. The LNs of HFD rats had a low initial tone, and rare low-amplitude phasic contractions were recorded in them. The parameters of contractile activity of the LNs of rats in HFD-OR and HFD+Dexa groups differed slightly from the corresponding parameters of the LNs of rats in the control group. Calorie restriction for 8 weeks in obese rats (HFD+DR) resulted in an increase in tone, frequency and amplitude of phasic contractions of the LNs compared to those in HFD rats. iNOS inhibition caused a significant increase in the tone, amplitude and frequency of phasic contractions of the LNs in the HFD group. An increase in the frequency of phasic contractions was observed only in the LNs of HFD+Dex and HFD+DR rats. Inhibition of cyclooxygenase 2 did not affect the contractile function of the LNs of rats of all groups, with the exception of animals from the HFD group (increase in the amplitude and frequency of phasic contractions). Tempol significantly increased the tone, frequency and amplitude of phasic contractions of the LNs in rats of the HFD group and increased the frequency of phasic contractions of the LNs of the HFD+DR rats. Conclusion. A high-fat diet leads to impaired contractile function of rat LNs and can create additional obstacles to the movement of lymph, promoting its leakage into surrounding tissues. Obesity is accompanied by the development of inflammation in the LNs and perinodal adipose tissue, which induces the expression of inducible NO synthase, cyclooxygenase-2 and the accumulation of reactive oxygen species (ROS). NO, prostaglandins and ROS have an inhibitory effect on the SMC capsules of the LNs, leading to a decrease in tonic tension and a weakening of spontaneous phasic contractions. The reason for inhibition of LN contractile function is obesity, but not consumption of food high in fat. Transferring obese rats to a calorie-restricted diet results in a decrease in body weight and visceral fat mass and an improvement in LN contractile function.

Indicators of oxidative-nitrosative stress of men injured as a result of combat actions

The article presents data on the state of lipid peroxidation and the activity of NO-synthase isoforms and arginase in lymphocytes and peripheral blood serum in men injured in combat (bullet and shrapnel wounds). 68 men injured as a result of hostilities (shrapnel and bullet wounds), who made up the main group, were examined. 48 practically healthy men were included in the control group. Patients of the main and control groups were divided into two age subgroups each: 20–39 years and 40–60 years. The MDA content in the blood serum of patients of both subgroups of the main group was 1.4 times higher than in the individuals of the corresponding subgroups of the control group (p<0.05). In peripheral blood lymphocytes, the MDA content in patients of both age subgroups of the main group was 1.3–1.4 times higher than in individuals of the corresponding subgroups of the control group (p<0.05; p<0.01). The activity of inducible (Ca2+-independent) de novo synthesis of NO significantly increases in blood serum and lymphocytes of men injured as a result of hostilities. At the same time, the activity of Ca2+-dependent NO-synthase in blood lymphocytes of men injured as a result of hostilities was 2.4 times lower compared to the values in practically healthy men (p<0.001), while it almost did not change in blood serum. It was confirmed that the inducible NOS can activate the processes of lipid peroxidation in men injured as a result of hostilities, as a direct significant correlation of high strength was recorded between the activity of Ca2+-independent iNOS and the MDA content (r=0.74; p<0.05). A significant correlation of medium strength was also established between arginase activity and MDA content (r=0.52; p<0.05). Keywords: malondialdehyde, NO-synthase, arginase.

Selenium Deficiency Can Promote the Expression of VEGF and Inflammatory Factors in Cartilage Differentiation and Mediates Cartilage Injury.

Selenium plays a crucial role as a micronutrient, primarily exerting its biological functions through selenoproteins. It has been established that selenium deficiency adversely impacts cartilage development, leading to alterations in chondrocyte function. In regions with low selenium intake, endemic osteochondrosis has been documented, characterized by compromised growth plate and articular cartilage formation. Vascular endothelial growth factor (VEGF) stands out as a pivotal angiogenic factor, with elevated levels contributing significantly to vascular invasion into chondrocytes. This VEGF-mediated invasion serves as a key signal, prompting morphological changes in the growth plate and initiating cartilage remodeling. In animal models, the selenium deficiency group exhibited heightened levels of the cartilage damage marker matrix metalloproteinases 13 (MMP13). This resulted in articular cartilage degeneration, accompanied by a substantial increase in VEGF expression within the growth plate and articular cartilage, as compared to the normal group. In a chondrogenic progenitor cell (CPC) differentiation model, insufficient selenium induced chondrocyte damage and upregulated inflammatory factors such as inducible NO synthase (iNOS) and cyclooxygenase-2 (COX2). The selenium-deficient groups showed elevated expressions of VEGF, VEGFR2, MMP13, Collagen X, and Angiopoietin 1, accelerating the degradation of the extracellular matrix (ECM), which further promoted the development of cartilage-related diseases. Taken together, these findings provide novel insights for a better understanding of the role of low selenium in cartilage degeneration and angiogenesis. They shed light on the intricate influence of low selenium levels on the development of articular cartilage, emphasizing the interconnected pathways and processes involved.

LAPAROTOMY ENHANCES THE PRODUCTION OF REACTIVE NITROGEN SPECIES IN THE HEARTS OF RATS EXPOSED TO A SINGLE PROLONGED STRESS

The aim of this study was to assess the production of reactive nitrogen species in the hearts of rats subjected to surgical trauma simulated against the background of post-traumatic stress disorder (PTSD). Materials and methods.The study was conducted on 42 white Wistar rats weighing 210-230 g, then divided into 6 groups: Group 1 consisted of intact animals, Group 2 included animals exposed to the induction of the PTSD model through single-prolonged stress (SPS), Group 3 – rats subjected to a sham operation, Group 4 – animals undergoing laparotomy, Group 5 – rats undergoing a sham surgical operation following SPS, and Group 6 – animals undergoing laparotomy under modeled SPS. NO synthase activity in the heart homogenate was determined spectrophotometrically. Results. The formation of peroxynitrite was assessed by the content of peroxynitrite of alkaline and alkaline-earth metals. SPS exposure significantly increases the production of reactive nitrogen species in the hearts of rats, in particular, it enhances NO synthase activity by activating the inducible isoform and reduces the activity of constitutive NO synthases, which is accompanied by the growth in the concentration of peroxynitrites. On the 7th day after laparotomy against the background of the experimental PTSD model, the indicators of nitrosative stress in the hearts of rats (total and inducible NO synthase activity and peroxynitrite concentration) significantly exceeded their values in the groups subjected to a single laparotomy and to a sham operation against the background of simulated SPS.

Sodium-Glucose Cotransporter-2 Inhibitor, Empagliflozin, Suppresses the Inflammatory Immune Response to Influenza Infection.

Influenza is a highly contagious, acute respiratory disease that causes significant public health and economic threats. Influenza infection induces various inflammatory mediators, IFNs, and recruitment of inflammatory cells in the host. This inflammatory "cytokine storm" is thought to play a role in influenza-induced lung pathogenesis. Empagliflozin is a drug primarily used to lower blood glucose in type II diabetes patients by inhibiting the sodium-glucose cotransporter-2 (SGLT-2) found in the proximal tubules in the kidneys. In this study, we have investigated the effects of empagliflozin on the pulmonary immune response to influenza infection. C57BL/6 mice (wild type) were infected with influenza A/PR/8/34 and treated with empagliflozin, and the disease outcomes were analyzed. Empagliflozin treatment decreased the expression of the inflammatory cytokines IL-1β, IL-6, and CCL2; the percentage of inflammatory monocytes and inducible NO synthase-positive macrophages; and IFN response genes Stat1 and CXCL9 during influenza infection. Further, empagliflozin treatment decreases the expression of IL-6, CCL2, and CCL5 in RAW264.7 macrophages and bone marrow-derived macrophages. However, empagliflozin treatment increased influenza viral titer during infection. Despite fostering an increased viral burden, treatment with empagliflozin decreases the mortality in wild type and high fat diet-induced atherosclerotic LDLR-/- mice. Based on our findings, empagliflozin may have therapeutic implications for use in patients to prevent lung damage and acute respiratory illness.

The Role of Potassium Channels in the Regulation of the Transport Function of Rats Lymph Nodes during Inflammation

Lymph formed in tissues necessarily passes through lymph nodes (LN), which not only perform an immune function, but also take part in lymph flow through rhythmic high-amplitude contractions. During inflammation, inducible NO synthase (iNOS) is expressed in the lymph nodes, which promotes relaxation of the LN capsule. This study examined the role of KATP- and BKCa-channels in sepsis-induced LN remodeling. Sepsis was induced in rats by cecal ligation-puncture surgery. After 12 and 24 h, mesenteric LN were removed and examined in a myograph. KATP-channels were activated by pinacidil and blocked by glibenclamide. BKCa-channels blocked TEA and activated NS 1619. The strength of tonic contraction of the LN under the action of activators and blockers was assessed. LN of septic rats named low level of tone during standard stretching. Pinacidil led to greater relaxation of LN in septic rats compared to the control group; the effect of glibenclamide was accompanied by an increase in tone. Pinacidil combined with glibenclamide did not lead to significant changes in LN tone. The use of NS 1619 was accompanied by relaxation of the LN; in the LN of septic rats, the effect was more pronounced. TEA (3 mM) led to an increase in LN tone; the LN of septic rats responded to the use of TEA with a greater contraction. We concluded that NO produced by expressed iNOS in animals with sepsis directly or indirectly activates KATP- and BKCa-channels of smooth muscle cells of the capsule in the LN, which leading to hyperpolarization of the smooth muscle cell membrane and their relaxation, which that promotes relaxation of the LN capsule and their hypertrophy of LN. In the future, KATP- and BKCa-channels of smooth muscle cells of the lymph node LN capsule may be a potential target for therapeutic intervention to correct the immune response by slowing down or accelerating the flow of lymph through the LN.

INOS inhibitor S-methylisothiourea alleviates smoke inhalation-induced acute lung injury by suppressing inflammation and macrophage infiltration

ObjectiveWe investigated the effects of the inducible NO synthase (iNOS) inhibitor, S-methylisothiourea (SMT), in a mouse model of smoke inhalation-induced acute lung injury (ALI) and explored the underlying molecular mechanism. Methods and analysisA mouse model of smoke inhalation-induced ALI was established. RNA-sequencing (seq) analysis was conducted to identify the differentially expressed genes (DEGs). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed for functional annotation of DEGs. Moreover, an immunofluorescence assay using macrophage marker F4/80 was performed to assess macrophage infiltration. A hypoxia-induced HUVEC model was used to mimic smoke inhalation-induced injury in endothelial cells. Finally, a transwell assay was used to analyze the chemoattractive effects of endothelial cells on macrophages. ResultsSMT markedly alleviated the pulmonary pathological symptoms, edema, and inflammatory response in the mouse smoke inhalation-induced ALI model. RNA-seq analysis revealed that SMT may diminish lung injury by regulating the levels of genes associated with inflammatory responses, cell chemokines, and adhesion. In vivo data revealed that the protective effects of SMT against smoke inhalation-induced ALI were partly achieved by inhibiting the production of adhesion molecules and infiltration of macrophages. Furthermore, in vitro data from the hypoxia-induced HUVEC model revealed that SMT reduced macrophage chemotaxis by inhibiting the production of chemokines and adhesion molecules in endothelial cells. ConclusioniNOS inhibitor SMT protects the lungs from smoke inhalation-induced ALI by reducing the production of pro-inflammatory cytokines, adhesion molecules, and chemokines in endothelial cells, thereby inhibiting inflammation and macrophage infiltration.

MECHANISMS OF NITROSATIVE STRESS AND DESTRUCTION OF THE ORGANIC MATRIX OF THE RAT MANDIBLE IN THE RECOVERY PERIOD AFTER ITS INCOMPLETE FRACTURE UNDER CONDITIONS OF CHRONIC ALCOHOL INTOXICATION

The mechanisms of nitrosative stress and depolymerization of biopolymers of the mandibular bone tissue after its incomplete fracture under conditions of chronic alcohol intoxication were investigated. The experiments were conducted on 20 white Wistar rats weighing 190-240 g, divided into 4 groups: Group 1 - intact animals, Group 2 - after reproduction of chronic alcohol intoxication, Group 3 - after modeling of mandibular fracture, Group 4 - after reproduction of mandibular fracture in the setting of chronic alcohol intoxication. The activity of total NO synthase, its constitutive and inducible isoforms, ornithine decarboxylase, concentrations of peroxynitrites of alkaline and alkaline-earth metals, free hydroxyproline, N-acetylneuraminic and hexuronic acids were determined in the homogenate of the standard mandible area by spectrophotometric method. It has been shown that the reproduction of chronic alcohol intoxication significantly increases the total and inducible NO synthase activity in the mandibular homogenate, accompanied by an increase in the concentration of the key marker of nitrosative stress – peroxynitrite. On the 14th day after the reconstruction of a mandibular fracture on the background of chronic alcohol intoxication, NO synthase activity and the content of peroxynitrites of alkaline and alkaline-earth metals in the bone homogenate exceed the results of groups with separate action of pathogenic factors. Under these conditions, the activity of the key enzyme of polyamine biosynthesis, ornithine decarboxylase, significantly decreases, and the depolymerization of bone biopolymers (collagen, glycoproteins, and proteoglycans) increases, which creates prerequisites for disruption of reparative processes in the fracture site.

Complement C3-Deficiency-Induced Constipation in FVB/N-C3em1Hlee/Korl Knockout Mice Was Significantly Relieved by Uridine and Liriope platyphylla L. Extracts.

Complement component 3 (C3) deficiency has recently been known as a cause of constipation, without studies on the therapeutic efficacy. To evaluate the therapeutic agents against C3-deficiency-induced constipation, improvements in the constipation-related parameters and the associated molecular mechanisms were examined in FVB/N-C3em1Hlee/Korl knockout (C3 KO) mice treated with uridine (Urd) and the aqueous extract of Liriope platyphylla L. (AEtLP) with laxative activity. The stool parameters and gastrointestinal (GI) transit were increased in Urd- and AEtLP-treated C3 KO mice compared with the vehicle (Veh)-treated C3 KO mice. Urd and AEtLP treatment improved the histological structure, junctional complexes of the intestinal epithelial barrier (IEB), mucin secretion ability, and water retention capacity. Also, an improvement in the composition of neuronal cells, the regulation of excitatory function mediated via the 5-hydroxytryptamine (5-HT) receptors and muscarinic acetylcholine receptors (mAChRs), and the regulation of the inhibitory function mediated via the neuronal nitric oxide synthase (nNOS) and inducible NOS (iNOS) were detected in the enteric nervous system (ENS) of Urd- and AEtLP-treated C3 KO mice. Therefore, the results of the present study suggest that C3-deficiency-induced constipation can improve with treatment with Urd and AEtLP via the regulation of the mucin secretion ability, water retention capacity, and ENS function.

Ethanol Extracts from the Aerial Parts of Inula japonica and Potentilla chinensis Alleviate Airway Inflammation in Mice That Inhaled Particulate Matter 10 and Diesel Particulate Matter.

Air pollution causes various airway diseases. However, many commonly used treatments can have high risks of side effects or are costly. To examine the anti-inflammatory properties of Inula japonica Thunb. and Potentilla chinensis Ser., a mouse model was generated via inhalation of both particulate matter 10 and diesel particulate matter, and 30% ethanol extracts of either I. japonica (IJ) or P. chinensis (PC) and a mixture of both ethanol extracts (IP) were orally administered to BALB/c mice for 12 days. IJ, PC, and IP inhibited immune cell numbers and their regulation in both the bronchoalveolar lavage fluid (BALF) and lungs. These agents suppressed the levels of interleukin (IL)-1α, IL-17, tumor necrosis factor (TNF)-α, C-X-C motif chemokine ligand (CXCL)-1, and CXCL-2 in BALF, and also inhibited F4/80 and IL-1 receptor-associated kinase (IRAK)-1 in lungs. They reduced the gene expression of TNF-α, CXCL-1, inducible NOS, COX-2, Mucin 5AC, and transient receptor potential cation channel subfamily V member 1 in lungs. These extracts also reduced histopathological changes and inflammatory progression, manifested as decreased cell infiltration, collagen deposition, and respiratory epithelial cell thickness. I. japonica and P. chinensis show potential for development as pharmaceuticals that suppress inflammatory progression and alleviate airway inflammation diseases caused by air pollutants.

Protective effect of hydrangenol on lipopolysaccharide-induced endotoxemia by suppressing intestinal inflammation

Hydrangenol, a dihydroisocoumarin, isolated from the leaves of Hydrangea serrata, possesses anti-inflammatory, anti-obesity, and anti-photoaging activities. In this study, we investigated the protective effects of hydrangenol (HG) against lipopolysaccharide (LPS)-induced endotoxemia and elucidated the underlying molecular mechanisms of action in C57BL/6 mice. Oral administration of HG (20 or 40 mg/kg) significantly restored the survival rate and population of macrophages, T helper cells (CD3+/CD4+), and Th17 cells (CD3+/CD4+/CCR6+) in the spleens of mice with LPS-induced endotoxemia. HG suppressed the expression of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β, and Interferon (IFN)-γ and the mRNA and protein expressions of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) in the intestine and lung of LPS-treated mice. Molecular data showed that HG ameliorated the activation of nuclear factor kappa B (NF-κB) p65, signal transducers and activators of transcription 3 (STAT3), and c-Fos and c-Jun (AP-1 subunits) via the myeloid differentiation primary response 88 (MyD88) dependent toll-like receptor 4 (TLR4) signaling pathway in the LPS-treated mouse intestines. HG treatment caused the recovery of LPS-induced impaired tight junction (occludin and claudin-2) protein and mRNA expressions. Furthermore, HG improved LPS-induced gut dysbiosis in mice. Taken together, our results suggest that HG protects against LPS-induced endotoxemia by restoring immune cells and the capacity of the intestinal barrier, reducing intestinal inflammation, and improving the composition of the gut microbiota.

NRF2 interacts with distal enhancer and inhibits nitric oxide synthase 2 expression in KRAS-driven pancreatic cancer cells

Nitric oxide is a pleiotropic free radical produced by three nitric oxide synthases (NOS1–3), of which inducible NOS2 is involved in tumor initiation and progression. In this study, RNA-seq, ChIP-seq and qRT-PCR experiments combined with bioinformatic analyses showed that NRF2 is a repressor of NOS2 gene by maintaining a distal enhancer located 22 kb downstream of TSS in an inactive state. Deletion of NRF2 leads to activation of the enhancer, which exerts a pioneering function before it is fully activated. Specifically, NRF2 controls the expression of NOS2 in response to intracellular oxidative stress and extracellular oxygen pressure. We found that abrogation of NOS2 expression by siRNAs partially reduced the ability of WT Panc-1 cells to form 3D spheroids, but strongly reduced the formation of 3D spheroids by NRF2-depleted Panc-1 cells. Mechanistically, this effect correlates with the finding that NOS2 and nitric oxide stimulate epithelial-to-mesenchymal transition in NRF2-depleted Panc-1 and MIA PaCa-2 cells. We also found that knockdown of NOS2 leads to blockade of 3D matrigel invasion of NRF2-depleted PDAC cells, demonstrating that a short-circuit in the reciprocal regulation of NOS2 and NRF2 attenuates the malignancy of PDAC cells. In summary, we show for the first time that: (i) NRF2 is a suppressor of NOS2 in pancreatic cancer cells; (ii) NRF2 binds to and inactivates an enhancer located 22 kb downstream of TSS of the NOS2 gene; (iii) activation of NOS2 requires suppression of NRF2; (iv) NOS2 is required for NRF2-depleted Panc-1 cells to maintain their malignancy and invasiveness.

Combined Lycium barbarum Polysaccharides with Plasmon-Activated Water Affect IFN-γ/TNF-α Induced Inflammation in Caco-2 Cells.

The effects of Lycium barbarum polysaccharides (LBP) and plasmon-activated water (PAW) against IFN-γ/TNF-α induced inflammation in human colon Caco-2 cells were investigated. Cells were divided into the control, induction, LBP treatment (100-500 μg/mL), and combination groups with PAW. Inflammation was induced 24 h with 10 ng/mL IFN-γ when cell confluency reached >90%, and various doses of LBP with or without PAW were treated for 3 h, and subsequently 50 ng/mL TNF-α was added for another 24 h to provoke inflammation. Combination of LBP with PAW significantly decreased the secretion of IL-6 and IL-8. Cyclooxygenase-2 and inducible NO synthase expression was attenuated in all LBP-treated groups with or without PAW. NLRP3 inflammasome and related protein PYCARD expression were inhibited by LBP at the highest dose (500 μg/mL). All doses of LBP alone significantly decreased p-ERK expression, but combination with PAW increased p-ERK expression compared to those without PAW. Additionally, 250 and 500 μg/mL of LBP with or without PAW inhibited procaspase-3/caspase-3 expression. Therefore, LBP possesses anti-inflammation and anti-apoptosis by inhibiting the secretion of inflammatory cytokines and the expression of NLRP3 inflammasome-related protein. The combination with PAW exerts additive or synergistic effect on anti-inflammation.

MEK inhibitors increase the mortality rate in mice with LPS-induced inflammation through IL-12-NO signaling

Lipopolysaccharide (LPS) is an endotoxin that can cause an acute inflammatory response. Nitric oxide (NO) is one of the most important innate immune system components and is synthesized by inducible NOS (iNOS) in macrophages in response to stimulation with LPS. LPS activates the RAS-RAF-mitogen-activated protein kinase/ERK kinase (MEK)-extracellular-signal-regulated kinase (ERK) signaling cascade in macrophages. The purpose of this study was to examine how the combination of LPS and MEK inhibitors, which have been used as anticancer agents in recent years, affects inflammation. We showed that MEK inhibitors enhanced iNOS expression and NO production in LPS-stimulated mouse bone marrow-derived macrophages. A MEK inhibitor increased the mortality rate in mice with LPS-induced inflammation. The expression of the cytokine interleukin-12 (IL-12) in macrophages was enhanced by the MEK inhibitor, as shown by a cytokine array and ELISA. IL-12 enhanced iNOS expression and NO production in response to LPS. We also showed that tumor necrosis factor (TNF-α) was secreted by macrophage after stimulation with LPS and that TNF-α and IL-12 synergistically induced iNOS expression and NO production. An anti-IL-12 neutralizing antibody prevented NO production and mortality in an LPS-induced inflammation mouse model in the presence of a MEK inhibitor. These results suggest that the MEK inhibitor increases the mortality rate in mice with LPS-induced inflammation through IL-12-NO signaling.

Nasal Nitric Oxide in Children: A Review of Current Outreach in Pediatric Respiratory Medicine.

Nasal nitric oxide (nNO) is a gas synthesized by the inducible and constitutive NO synthase (NOS) enzyme in the airway cells of the nasal mucosa. Like lung nitric oxide, it is thought to be associated with airway inflammation in various respiratory diseases in children. The aim of our review was to investigate the current state of use of nNO measurement in children. A comprehensive search was conducted using the Web of Science and PubMed databases specifically targeting publications in the English language, with the following keywords: nasal NO, children, allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, primary ciliary dyskinesia (PCD), and cystic fibrosis (CF). We describe the use of nNO in pediatric allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, PCD, and CF based on the latest literature. nNO is a noninvasive, clinically applicable test for use in pediatric allergic rhinitis, chronic rhinosinusitis, acute rhinosinusitis, PCD, and CF. It can be used as a complementary method in the diagnosis of these respiratory diseases and as a monitoring method for the treatment of allergic rhinitis and acute and chronic rhinosinusitis.

Cytokine-Induced iNOS in A549 Alveolar Epithelial Cells: A Potential Role in COVID-19 Lung Pathology.

In COVID-19, an uncontrolled inflammatory response might worsen lung damage, leading to acute respiratory distress syndrome (ARDS). Recent evidence points to the induction of inducible nitric oxide synthase (NOS2/iNOS) as a component of inflammatory response since NOS2 is upregulated in critical COVID-19 patients. Here, we explore the mechanisms underlying the modulation of iNOS expression in human alveolar cells. A549 WT and IRF1 KO cells were exposed to a conditioned medium of macrophages treated with SARS-CoV-2 spike S1. Additionally, the effect of IFNγ, IL-1β, IL-6, and TNFα, either alone or combined, was addressed. iNOS expression was assessed with RT-qPCR and Western blot. The effect of baricitinib and CAPE, inhibitors of JAK/STAT and NF-kB, respectively, was also investigated. Treatment with a conditioned medium caused a marked induction of iNOS in A549 WT and a weak stimulation in IRF1 KO. IFNγ induced NOS2 and synergistically cooperated with IL-1β and TNFα. The inhibitory pattern of baricitinb and CAPE indicates that cytokines activate both IRF1 and NF-κB through the JAK/STAT1 pathway. Cytokines secreted by S1-activated macrophages markedly induce iNOS, whose expression is suppressed by baricitinib. Our findings sustain the therapeutic efficacy of this drug in COVID-19 since, besides limiting the cytokine storm, it also prevents NOS2 induction.

Influence of a Nitric Oxide Synthase Inhibitor on the Anxiolytic, Stimulating, and Analgesic Effects of Long-Term Perinatal Caffeine Exposure in Rats.

We studied the effect of inducible NO synthase (iNOS) inhibitor aminoguanidine on the behavioral effects of chronic perinatal caffeine exposure. Administration of caffeine in the prenatal and early postnatal periods led to the development of anxiolytic, stimulating, and analgesic effects. Administration of aminoguanidine attenuated the anxiolytic and stimulating effects and potentiated the analgesic effect of perinatal administration of caffeine. Chronic perinatal administration of caffeine leads to significant changes in the level of anxiety, motor activity, and pain sensitivity, and inhibition of iNOS has a pronounced multidirectional effect on these effects.

Precancerous nature of intestinal metaplasia with increased chance of conversion and accelerated DNA methylation

ObjectiveThe presence of intestinal metaplasia (IM) is a risk factor for gastric cancer. However, it is still controversial whether IM itself is precancerous or paracancerous. Here, we aimed to explore...

Variation in Exon 29 of the NOS1 Gene Does Not Contribute to Parkinson's Disease in the North Karnataka Population.

Nitric oxide (NO) overproduction has been found to have neurotoxic effects on the brain. Moreover, in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced, the suppression of the NO-synthesizing enzymes, such as neuronal nitric oxide synthase (nNOS) and inducible NOS (iNOS), has neuroprotective benefits in Parkinson's disease (PD). These findings imply that NOS may have a role in regulating the nigral dopaminergic neurons' tolerance to environmental stressors in PD. In the present study, we investigated variations in the NOS1 gene that may raise the likelihood of PD. PD patients who visited the neurology departments of several medical colleges and hospitals in North Karnataka, India, between 2009 and 2011 were included in the study. The detailed clinic pathological details were obtained from 100 PD patients. Genomic DNA was isolated using the kit method followed by the evaluation of the quality and quantity of isolated gDNA. Polymerase chain reaction (PCR) amplification of exon 29 was performed, and sequencing was performed using the Applied BiosystemsABI 3500 Sanger sequencing platform. The present study is comprised of 100 PD patients, which includes 65 males and 35 females. There were 64 sporadic, 34 idiopathic, and two familial PD cases. The majority (67.1%) of PD cases were from metropolitan areas. Community-based segregation showed that the maximum cases were from Hindu Lingayat. A proportion (90.8%) of the patients had tremors, 32.7% of them displayed slowness in their daily tasks, and 8.1% of them had dyskinesia. Molecular analysis showed two untranslated region(UTR) variations g.151787 del T (rs1434015950) and g.151745 C>T (rs2682826) in our study group. The absence of mutations in the targeted NOS1 gene in the PD patients from North Karnataka shows the involvement of other genes in the molecular pathophysiology. Thus, it is crucial to screen other possible genes using cutting-edge technology to obtain a clear picture of the genetics of PD.