scholarly journals Ascorbate inhibits iNOS expression and preserves vasoconstrictor responsiveness in skeletal muscle of septic mice

2003 ◽  
Vol 285 (1) ◽  
pp. R50-R56 ◽  
Author(s):  
Feng Wu ◽  
John X. Wilson ◽  
Karel Tyml
Keyword(s):  
Skeletal Muscle ◽  
Arterial Pressure ◽  
Vascular Reactivity ◽  
Cecal Ligation ◽  
Interferon Γ ◽  
Inos Expression ◽  
Inos Mrna ◽  
Valuable Adjunct

Inducible nitric oxide synthase (iNOS) expression in blood vessels contributes to the vascular hyporeactivity characteristic of sepsis. Our previous work demonstrated in vitro that ascorbate inhibits iNOS expression in lipopolysaccharide- and interferon-γ-stimulated skeletal muscle endothelial cells (ECs) through an antioxidant mechanism. The present study evaluated in vivo the hypothesis that administration of ascorbate decreases oxidative stress, prevents endothelial iNOS expression, and improves vascular reactivity in septic skeletal muscle. Sepsis was induced in C57BL/6 mice by cecal ligation and puncture (CLP). Plasma nitrite and nitrate (NOx) levels were elevated by 6 h after CLP. Prior ascorbate bolus injection (200 mg/kg body wt iv) blocked the elevation of plasma NOx and abolished the expression of iNOS protein and activity in the septic skeletal muscle. We also demonstrated that iNOS mRNA determined by RT-PCR was induced in the microvascular ECs of the muscle at 3 h after CLP. This induction was attenuated by prior ascorbate administration. Ascorbate inhibition of iNOS expression was associated with decreased oxidant levels in the septic muscle. Moreover, ascorbate administration restored partially the baseline arterial pressure and preserved completely the microvascular constriction and arterial pressure responses to norepinephrine in CLP mice. These results suggest that early administration of ascorbate may be a valuable adjunct treatment of sepsis.

scholarly journals Inhibition of nitric oxide synthase expression by PPM-18, a novel anti-inflammatory agent, in vitro and in vivo

1997 ◽  
Vol 328 (2) ◽  
pp. 363-369 ◽  
Author(s):  
M. Sheu YU ◽  
Jeng F. WU Tzong L. LIN ◽  
C. Sheng KUO
Keyword(s):  
Nuclear Extract ◽  
Inos Expression ◽  
Inos Mrna ◽  
Mobility Shift ◽  
Mrna Accumulation ◽  
Inflammatory Agent ◽  
Nitrite Production ◽  
Anti Inflammatory

We studied the effect of PPM-18, a chemically synthesized naphthoquinone derivative and also an anti-inflammatory agent, on the lipopolysaccharide (LPS)-activated inducible NO synthase (iNOS) expression in rat alveolar macrophages. Pretreatment of macrophages with PPM-18 (0.1-10 μM) significantly inhibited nitrite production, iNOS protein expression and iNOS mRNA accumulation. PPM-18 did not directly affect the enzymic activities of iNOS and other constitutive NOS forms. The LPS-induced increase in nuclear transcription factor κB (NF-κB) p65 and p50 in nucleus was suppressed by PPM-18 (10 μM). Moreover electrophoretic mobility-shift assays demonstrated that PPM-18 inhibited DNA binding to NF-κB induced by LPS in whole cells but not when added in the nuclear extract, suggesting that PPM-18 did not interfere directly with the binding of NF-κB to DNA and that some events had to be processed before NF-κB could bind DNA. Examination of NF-κB showed that PPM-18 stabilized the NF-κB inhibitor, IκBα, by preventing its degradation from NF-κB. Therefore the stabilization of IκBα might have contributed to the inhibition of NF-κB activation. These results also indicate strongly that NF-κB is involved in the production of NO on stimulation by LPS. PPM-18 significantly decreased the production of tumour necrosis factor α in response to LPS. PPM-18 protects mice against LPS-induced lethal toxicity. These results also indicate that PPM-18 is a potent inhibitor of iNOS expression by blocking the binding of NF-κB to promoter and exerts a beneficial effect in the mouse model of sepsis.

Selective in vivo inhibition of inducible nitric oxide synthase in a rat model of sepsis

1999 ◽  
Vol 86 (5) ◽  
pp. 1739-1744 ◽  
Author(s):  
J. A. Scott ◽  
D. G. McCormack
Keyword(s):  
Nitric Oxide ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Thoracic Aorta ◽  
Cecal Ligation ◽  
Selective Inhibition ◽  
Inos Inhibitor ◽  
The Mean

Elevated production of nitric oxide (NO) by the inducible NO synthase (type II, iNOS) may contribute to the vascular hyporesponsiveness and hemodynamic alterations associated with sepsis. Selective inhibition of this isoenzyme is a possible therapeutic intervention to correct these pathophysiological alterations. Aminoguanidine has been shown to be a selective iNOS inhibitor and to correct the endotoxin-mediated vascular hypocontractility in vitro. However, to date aminoguanidine has not been shown to selectively block iNOS activity in vivo. The in vivo effects of aminoguanidine were assessed in the cecal ligation and perforation model of sepsis in rats. Aminoguanidine (1.75–175 mg/kg) was administered to septic and sham-operated rats for 3 h before euthanasia and harvest of tissues. NOS activities were determined in the thoracic aorta and lung from these animals. Aminoguanidine (17.5 mg/kg) did not alter the mean arterial pressure; however, it did inhibit induced iNOS (but not constitutive NOS) activity in the lung and thoracic aorta from septic animals. Only the higher dose of aminoguanidine (175 mg/kg) was able to increase the mean arterial pressure in septic and sham-operated animals. Thus selective inhibition of iNOS in vivo with aminoguanidine is possible, but our data suggest that other mechanisms, in addition to iNOS induction, are responsible for the loss of vascular tone characteristic of sepsis.

scholarly journals Neutral sphingomyelinase 2 is required for cytokine-induced skeletal muscle calpain activation

2015 ◽  
Vol 309 (6) ◽  
pp. L614-L624 ◽  
Author(s):  
Gerald S. Supinski ◽  
Alexander P. Alimov ◽  
Lin Wang ◽  
Xiao-Hong Song ◽  
Leigh A. Callahan
Keyword(s):  
Skeletal Muscle ◽  
Cecal Ligation ◽  
C2c12 Cells ◽  
In Vivo Model ◽  
Calpain Activity ◽  
Calpain Activation ◽  
Neutral Sphingomyelinase ◽  
Cecal Ligation Puncture

Calpain contributes to infection-induced diaphragm dysfunction but the upstream mechanism(s) responsible for calpain activation are poorly understood. It is known, however, that cytokines activate neutral sphingomyelinase (nSMase) and nSMase has downstream effects with the potential to increase calpain activity. We tested the hypothesis that infection-induced skeletal muscle calpain activation is a consequence of nSMase activation. We administered cytomix (20 ng/ml TNF-α, 50 U/ml IL-1β, 100 U/ml IFN-γ, 10 μg/ml LPS) to C2C12 muscle cells to simulate the effects of infection in vitro and studied mice undergoing cecal ligation puncture (CLP) as an in vivo model of infection. In cell studies, we assessed sphingomyelinase activity, subcellular calcium levels, and calpain activity and determined the effects of inhibiting sphingomyelinase using chemical (GW4869) and genetic (siRNA to nSMase2 and nSMase3) techniques. We assessed diaphragm force and calpain activity and utilized GW4869 to inhibit sphingomyelinase in mice. Cytomix increased cytosolic and mitochondrial calcium levels in C2C12 cells ( P < 0.001); addition of GW4869 blocked these increases ( P < 0.001). Cytomix also activated calpain, increasing calpain activity ( P < 0.02), and the calpain-mediated cleavage of procaspase 12 ( P < 0.001). Procaspase 12 cleavage was attenuated by either GW4869 ( P < 0.001), BAPTA-AM ( P < 0.001), or siRNA to nSMase2 ( P < 0.001) but was unaffected by siRNA to nSMase3. GW4869 prevented CLP-induced diaphragm calpain activation and diaphragm weakness in mice. These data suggest that nSMase2 activation is required for the development of infection-induced diaphragm calpain activation and muscle weakness. As a consequence, therapies that inhibit nSMase2 in patients may prevent infection-induced skeletal muscle dysfunction.

scholarly journals Antisense peptide nucleic acid-functionalized cationic nanocomplex for in vivo mRNA detection

2013 ◽  
Vol 3 (3) ◽  
pp. 20120059 ◽  
Author(s):  
Yuefei Shen ◽  
Ritu Shrestha ◽  
Aida Ibricevic ◽  
Sean P. Gunsten ◽  
Michael J. Welch ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Interferon Γ ◽  
Raw264.7 Cells ◽  
Mouse Lung ◽  
Inos Mrna ◽  
Intratracheal Administration ◽  
Specificity And Sensitivity ◽  
Theranostic Agents

Acute lung injury (ALI) is a complex syndrome with many aetiologies, resulting in the upregulation of inflammatory mediators in the host, followed by dyspnoea, hypoxemia and pulmonary oedema. A central mediator is inducible nitric oxide synthase (iNOS) that drives the production of NO and continued inflammation. Thus, it is useful to have diagnostic and therapeutic agents for targeting iNOS expression. One general approach is to target the precursor iNOS mRNA with antisense nucleic acids. Peptide nucleic acids (PNAs) have many advantages that make them an ideal platform for development of antisense theranostic agents. Their membrane impermeability, however, limits biological applications. Here, we report the preparation of an iNOS imaging probe through electrostatic complexation between a radiolabelled antisense PNA-YR 9 · oligodeoxynucleotide (ODN) hybrid and a cationic shell-cross-linked knedel-like nanoparticle (cSCK). The Y (tyrosine) residue was used for 123 I radiolabelling, whereas the R 9 (arginine 9 ) peptide was included to facilitate cell exit of untargeted PNA. Complete binding of the antisense PNA-YR 9 · ODN hybrid to the cSCK was achieved at an 8 : 1 cSCK amine to ODN phosphate (N/P) ratio by a gel retardation assay. The antisense PNA-YR 9 · ODN · cSCK nanocomplexes efficiently entered RAW264.7 cells, whereas the PNA-YR 9 · ODN alone was not taken up. Low concentrations of 123 I-labelled antisense PNA-YR 9 · ODN complexed with cSCK showed significantly higher retention of radioactivity when iNOS was induced in lipopolysaccharide+interferon-γ-activated RAW264.7 cells when compared with a mismatched PNA. Moreover, statistically, greater retention of radioactivity from the antisense complex was also observed in vivo in an iNOS-induced mouse lung after intratracheal administration of the nanocomplexes. This study demonstrates the specificity and sensitivity by which the radiolabelled nanocomplexes can detect iNOS mRNA in vitro and in vivo and their potential for early diagnosis of ALI.

scholarly journals Triptolide suppresses oral cancer cell PD-L1 expression in the interferon-γ-modulated microenvironment in vitro, in vivo, and in clinical patients

2021 ◽  
Vol 133 ◽  
pp. 111057
Author(s):  
Chin-Shan Kuo ◽  
Cheng-Yu Yang ◽  
Chih-Kung Lin ◽  
Gu-Jiun Lin ◽  
Huey-Kang Sytwu ◽  
...  
Keyword(s):  
Oral Cancer ◽  
Cancer Cell ◽  
Interferon Γ ◽  
Oral Cancer Cell

α2-Adrenoceptor agonist dexmedetomidine protects septic acute kidney injury through increasing BMP-7 and inhibiting HDAC2 and HDAC5

2012 ◽  
Vol 303 (10) ◽  
pp. F1443-F1453 ◽  
Author(s):  
Chung-Hsi Hsing ◽  
Chiou-Feng Lin ◽  
Edmund So ◽  
Ding-Ping Sun ◽  
Tai-Chi Chen ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Histone Deacetylases ◽  
Trichostatin A ◽  
Histone H3 ◽  
Cecal Ligation ◽  
Kidney Injury ◽  
Protective Effects ◽  
Tnf Α

Bone morphogenetic protein (BMP)-7 protects sepsis-induced acute kidney injury (AKI). Dexmedetomidine (DEX), an α2-adrenoceptor (α2-AR) agonist, has anti-inflammatory effects. We investigated the protective effects of DEX on sepsis-induced AKI and the expression of BMP-7 and histone deacetylases (HDACs). In vitro , the effects of DEX or trichostatin A (TSA, an HDAC inhibitor) on TNF-α, monocyte chemotactic protein (MCP-1), BMP-7, and HDAC mRNA expression in LPS-stimulated rat renal tubular epithelial NRK52E cells, was determined using real-time PCR. In vivo, mice were intraperitoneally injected with DEX (25 μg/kg) or saline immediately and 12 h after cecal ligation and puncture (CLP) surgery. Twenty-four hours after CLP, we examined kidney injury and renal TNF-α, MCP-1, BMP-7, and HDAC expression. Survival was monitored for 120 h. LPS increased HDAC2, HDAC5, TNF-α, and MCP-1 expression, but decreased BMP-7 expression in NRK52E cells. DEX treatment decreased the HDAC2, HDAC5, TNF-α, and MCP-1 expression, but increased BMP-7 and acetyl histone H3 expression, whose effects were blocked by yohimbine, an α2-AR antagonist. With DEX treatment, the LPS-induced TNF-α expression and cell death were attenuated in scRNAi-NRK52E but not BMP-7 RNAi-NRK52E cells. In CLP mice, DEX treatment increased survival and attenuated AKI. The expression of HDAC2, HDAC5, TNF-α, and MCP-1 mRNA in the kidneys of CLP mice was increased, but BMP-7 was decreased. However, DEX treatment reduced those changes. DEX reduces sepsis-induced AKI by decreasing TNF-α and MCP-1 and increasing BMP-7, which is associated with decreasing HDAC2 and HDAC5, as well as increasing acetyl histone H3.

Pulsatile Pressure and Flow in the Skeletal Muscle Microcirculation

1990 ◽  
Vol 112 (4) ◽  
pp. 437-443 ◽  
Author(s):  
Shou-Yan Lee ◽  
G. W. Schmid-Scho¨nbein
Keyword(s):  
Skeletal Muscle ◽  
Arterial Pressure ◽  
Time Course ◽  
Venous Pressure ◽  
Time Dependent ◽  
Physiological Importance ◽  
Pulsatile Pressure ◽  
Theoretical Predictions ◽  
Skeletal Muscle Microcirculation

Although blood flow in the microcirculation of the rat skeletal muscle has negligible inertia forces with very low Reynolds number and Womersley parameter, time-dependent pressure and flow variations can be observed. Such phenomena include, for example, arterial flow overshoot following a step arterial pressure, a gradual arterial pressure reduction for a step flow, or hysteresis between pressure and flow when a pulsatile pressure is applied. Arterial and venous flows do not follow the same time course during such transients. A theoretical analysis is presented for these phenomena using a microvessel with distensible viscoelastic walls and purely viscous flow subject to time variant arterial pressures. The results indicate that the vessel distensibility plays an important role in such time-dependent microvascular flow and the effects are of central physiological importance during normal muscle perfusion. In-vivo whole organ pressure-flow data in the dilated rat gracilis muscle agree in the time course with the theoretical predictions. Hemodynamic impedances of the skeletal muscle microcirculation are investigated for small arterial and venous pressure amplitudes superimposed on an initial steady flow and pressure drop along the vessel.

scholarly journals Down-regulation of SNHG16 alleviates the acute lung injury in sepsis rats through miR-128-3p/HMGB3 axis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Junli Sun ◽  
Keke Xin ◽  
Chenghui Leng ◽  
Jianlin Ge
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Western Blot ◽  
Cell Viability ◽  
Inflammatory Diseases ◽  
Cecal Ligation ◽  
Inflammatory Factors ◽  
Lung Epithelial

Abstract Background Long noncoding RNAs contribute to various inflammatory diseases, including sepsis. We explore the role of small nucleolar RNA host gene 16 (SNHG16) in sepsis-mediated acute lung injury (ALI) and inflammation. Methods A sepsis-induced ALI rat model was constructed by the cecal ligation and perforation method. The profiles of SNHG16, miR-128-3p, and high-mobility group box 3 (HMGB3) were monitored by quantitative reverse transcription PCR and Western blot. The pathologic changes of lung tissues were evaluated by Hematoxylin–Eosin staining, immunohistochemistry, and dry and wet method. Meanwhile, the pro-inflammatory factors and proteins were determined by ELISA and Western blot. In contrast, a sepsis model in BEAS-2B was induced with lipopolysaccharide (LPS) to verify the effects of SNHG16/miR-128-3p/HMGB3 on lung epithelial cell viability and apoptosis. Results As a result, SNHG16 and HMGB3 were up-regulated, while miR-128-3p was down-regulated in sepsis-induced ALI both in vivo and in vitro. Inhibiting SNHG16 reduced the apoptosis and inflammation in the sepsis-induced ALI model. Overexpressing SNHG16 promoted LPS-mediated lung epithelial apoptosis and inhibited cell viability and inflammation, while miR-128-3p had the opposite effects. Mechanistically, SNHG16 targeted miR-128-3p and attenuated its expression, while miR-128-3p targeted the 3′ untranslated region of HMGB3. Conclusions Overall, down-regulating SNHG16 alleviated the sepsis-mediated ALI by regulating miR-128-3p/HMGB3.

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