scholarly journals Enhancement of Cellular Antioxidant-Defence Preserves Diastolic Dysfunction via Regulation of Both Diastolic Zn2+and Ca2+and Prevention of RyR2-Leak in Hyperglycemic Cardiomyocytes

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Erkan Tuncay ◽  
Esma N. Okatan ◽  
Aysegul Toy ◽  
Belma Turan
Keyword(s):  
Diastolic Dysfunction ◽  
Ryanodine Receptors ◽  
Diabetic Rats ◽  
Oxidative Stress Marker ◽  
Macromolecular Complex ◽  
Resting Cells ◽  
Dependent Manner ◽  
Antioxidant Defence ◽  
Concentration Dependent Manner ◽  
Protein Levels

We examined whether cellular antioxidant-defence enhancement preserves diastolic dysfunction via regulation of both diastolic intracellular free Zn2+and Ca2+levels (Zn2+iandCa2+i) levelsN-acetyl cysteine (NAC) treatment (4 weeks) of diabetic rats preserved altered cellular redox state and also prevented diabetes-induced tissue damage and diastolic dysfunction with marked normalizations in the restingZn2+iandCa2+i. The kinetic parameters of transient changes in Zn2+and Ca2+under electrical stimulation and the spatiotemporal properties of Zn2+and Ca2+sparks in resting cells are found to be normal in the treated diabetic group. Biochemical analysis demonstrated that the NAC treatment also antagonized hyperphosphorylation of cardiac ryanodine receptors (RyR2) and significantly restored depleted protein levels of both RyR2 and calstabin2. Incubation of cardiomyocytes with 10 µM ZnCl2exerted hyperphosphorylation in RyR2 as well as higher phosphorphorylations in both PKA and CaMKII in a concentration-dependent manner, similar to hyperglycemia. Our present data also showed that a subcellular oxidative stress marker, NF-κB, can be activated if the cells are exposed directly to Zn2+. We thus for the first time report that an enhancement of antioxidant defence in diabetics via directly targeting heart seems to prevent diastolic dysfunction due to modulation of RyR2 macromolecular-complex thereby leading to normalizedCa2+iandZn2+iin cardiomyocytes.

scholarly journals The Antinociceptive, Antioxidant and Anti-Inflammatory Effects of 5-Fluoro-2-Oxindole during Inflammatory Pain

Antioxidants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1249
Author(s):  
Alejandro Redondo ◽  
Gabriela Riego ◽  
Olga Pol
Keyword(s):  
Inflammatory Pain ◽  
Inflammatory Responses ◽  
Protoporphyrin Ix ◽  
Mitogen Activated Protein Kinase ◽  
Oxidative Stress Marker ◽  
Heme Oxygenase 1 ◽  
Peripheral Inflammation ◽  
Dependent Manner ◽  
Protein Levels ◽  
Antinociceptive Effects

Recent studies demonstrate that 5-fluoro-2-oxindole inhibits neuropathic pain but the antinociceptive actions of this drug and its effects on the plasticity, oxidative and inflammatory changes induced by peripheral inflammation as well as on the effects and expression of µ-opioid receptors (MOR) have not been evaluated. In C57BL/6 male mice with inflammatory pain provoked by the subplantar administration of complete Freund’s adjuvant (CFA), we evaluated: (1) the antinociceptive actions of 5-fluoro-2-oxindole and its reversion with the HO-1 inhibitor, tin protoporphyrin IX (SnPP); (2) the effects of 5-fluoro-2-oxindole in the protein levels of mitogen-activated protein kinase (MAPK), Nrf2, NADPH quinone oxidoreductase1 (NQO1), heme oxygenase 1 (HO-1), oxidative stress marker (4-hydroxy-2-nonenal; 4-HNE), inducible nitric oxide synthase (NOS2), microglial markers (CD11b/c and IBA-1), and MOR in the spinal cord and/or paw of animals with inflammatory pain; (3) the antinociceptive effects of morphine in 5-fluoro-2-oxindole pre-treated animals. Treatment with 5 and 10 mg/kg of 5-fluoro-2-oxindole inhibited the allodynia and hyperalgesia induced by CFA in a different, time-dependent manner. These effects were reversed by SnPP. Treatment with 5-fluoro-2-oxindole increased the expression of NQO1, HO-1 and MOR and inhibited the CFA-induced upregulation of phosphorylated MAPK, 4-HNE, NOS2, CD11b/c and IBA-1 in spinal cords and/or paws. The local effects of morphine were improved with 5-fluoro-2-oxindole. This work reveals that 5-fluoro-2-oxindole inhibits the plasticity, oxidative and inflammatory responses provoked by peripheral inflammation and potentiates the antinociceptive effects of morphine. Thus, treatment with 5-fluoro-2-oxindole alone and/or combined with morphine are two remarkable new procedures for chronic inflammatory pain management.

scholarly journals The contribution of inositol 1,4,5-trisphosphate and ryanodine receptors to agonist-induced Ca2+ signaling of airway smooth muscle cells

2009 ◽  
Vol 297 (2) ◽  
pp. L347-L361 ◽  
Author(s):  
Yan Bai ◽  
Martin Edelmann ◽  
Michael J. Sanderson
Keyword(s):  
Wave Propagation ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Airway Smooth Muscle ◽  
Ryanodine Receptors ◽  
Muscle Cells ◽  
Airway Smooth Muscle Cells ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Inositol 1,4,5 Trisphosphate

The relative contribution of inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) and ryanodine receptors (RyRs) to agonist-induced Ca2+ signaling in mouse airway smooth muscle cells (SMCs) was investigated in lung slices with phase-contrast or laser scanning microscopy. At room temperature (RT), methacholine (MCh) or 5-hydroxytryptamine (5-HT) induced Ca2+ oscillations and an associated contraction in small airway SMCs. The subsequent exposure to an IP3R antagonist, 2-aminoethoxydiphenyl borate (2-APB), inhibited the Ca2+ oscillations and induced airway relaxation in a concentration-dependent manner. 2-APB also inhibited Ca2+ waves generated by the photolytic release of IP3. However, the RyR antagonist ryanodine had no significant effect, at any concentration, on airway contraction or agonist- or IP3-induced Ca2+ oscillations or Ca2+ wave propagation. By contrast, a second RyR antagonist, tetracaine, relaxed agonist-contracted airways and inhibited agonist-induced Ca2+ oscillations in a concentration-dependent manner. However, tetracaine did not affect IP3-induced Ca2+ release or wave propagation nor the Ca2+ content of SMC Ca2+ stores as evaluated by Ca2+-release induced by caffeine. Conversely, both ryanodine and tetracaine completely blocked agonist-independent slow Ca2+ oscillations induced by KCl. The inhibitory effects of 2-APB and absence of an effect of ryanodine on MCh-induced airway contraction or Ca2+ oscillations of SMCs were also observed at 37°C. In Ca2+-permeable SMCs, tetracaine inhibited agonist-induced contraction without affecting intracellular Ca2+ levels indicating that relaxation also resulted from a reduction in Ca2+ sensitivity. These results indicate that agonist-induced Ca2+ oscillations in mouse small airway SMCs are primary mediated via IP3Rs and that tetracaine induces relaxation by both decreasing Ca2+ sensitivity and inhibiting agonist-induced Ca2+ oscillations via an IP3-dependent mechanism.

scholarly journals Liver X Receptor Agonists Inhibit the Phospholipid Regulatory Gene CTP: Phosphoethanolamine Cytidylyltransferase-Pcyt2

2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Lin Zhu ◽  
Marica Bakovic
Keyword(s):  
Inflammatory Responses ◽  
Regulatory Gene ◽  
Liver X Receptor ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Protein Levels ◽  
Kennedy Pathway ◽  
Mrna And Protein Expression ◽  
Novel Target ◽  
Lxr Agonists

Metabolic pulse-chase experiments demonstrated that 25-hydroxycholesterol (25-OH), the endogenous activator of the liver X receptor (LXR), significantly reduced the biosynthesis of phosphatidylethanolamine via CDP-ethanolamine (Kennedy) pathway at the step catalyzed by CTP: phosphoethanolamine cytidylyltransferase (Pcyt2). In the mouse embryonic fibroblasts C3H10T1/2, the LXR synthetic agonist TO901317 lowered Pcyt2 promoter-luciferase activity in a concentration-dependent manner. Furthermore, 25-OH and TO901317 reduced mouse Pcyt2 mRNA and protein levels by 35–60%. The inhibitory effects of oxysterols and TO901317 on the Pcyt2 promoter function, mRNA and protein expression were conserved in the human breast cancer cells MCF-7. These studies identify the Pcyt2 gene as a novel target whereby LXR agonists may indirectly modulate inflammatory responses and atherosclerosis.

scholarly journals Pyridoxine Stimulates Filaggrin Production in Human Epidermal Keratinocytes

2021 ◽  
Author(s):  
Miyuki Fujishiro ◽  
Shoichi Yahagi ◽  
Shota Takemi ◽  
Takafumi Sakai ◽  
ichiro sakata
Keyword(s):  
Pyridoxal Phosphate ◽  
Seborrheic Dermatitis ◽  
Epidermal Differentiation ◽  
Disulfonic Acid ◽  
Epidermal Keratinocytes ◽  
Marker Genes ◽  
Dependent Manner ◽  
Human Epidermal Keratinocytes ◽  
Concentration Dependent Manner ◽  
Protein Levels

Abstract Pyridoxine (PN), one of the vitamers of vitamin B6, plays an important role in the maintenance of epidermal function and is used to treat acne and rough skin. Clinical studies have revealed that PN deficiency causes skin problems such as seborrheic dermatitis and stomatitis. However, the detailed effects of PN and its mechanism of action in epidermal function are poorly understood. In this study, we examined the effects of PN on epidermal function in normal human epidermal keratinocytes and found that PN specifically causes an increase in the expression of profilaggrin mRNA, among marker genes of terminal epidermal differentiation. In addition, PN treatment caused an increase in the production of filaggrin protein in a concentration-dependent manner. Treatment with P2x purinoceptor antagonists, namely, pyridoxal phosphate-6-azo (benzene-2,4-disulfonic acid) tetrasodium salt hydrate and TNP-ATP hydrate, induced an increase in the filaggrin protein levels. Moreover, we showed that elevated filaggrin production induced upon PN treatment was suppressed by ATP (known as P2x purinoceptor agonist). This study is the first to report that PN causes an increase in filaggrin transcription and production, and these results suggest that PN-induced filaggrin production may be a useful target as a daily care component in atopic dermatitis, wherein filaggrin levels are specifically reduced.

Abstract 15558: Characterization of Sarcolemmal K Atp Channels in Human Ipsc-derived Cardiomyocytes

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Robert Geiger ◽  
Naheed Fatima ◽  
Michael Klein ◽  
Robert E Goldstein ◽  
Mark C HAIGNEY ◽  
...  
Keyword(s):  
Katp Channel ◽  
Field Potential ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Protein Levels ◽  
Typical Composition ◽  
Human Ipsc ◽  
Action Potential Shortening

Background: The ATP-sensitive potassium channel (KATP) plays a key role in protecting heart muscle during metabolic challenges such as ischemia. KATP activation causes action potential shortening that reduces calcium entry and contraction thus reducing calcium overload induced damage and preserving energy reserves. Cardiomyocytes derived from human inducible pluripotent stem cell (hiPSC) have emerged as a model to study cardiac function, however there are few studies that have focused on KATP. Methods: In the present study, cardiomyocytes were either generated from hiPSC using heparin- based chemically defined media or purchased from Cellular Dynamics (iCells2). Expression of the pore-forming (Kir6.2) and regulatory (SUR1 & SUR2) subunits of the KATP channel during differentiation were assessed using western blot. KATP function was assessed by measuring the field potential duration (FPD) and spontaneous beat rate in a confluent monolayer using the Axion Maestro multielectrode array system. Cells were probed using the KATP activators P1075 and diazoxide, specific for SUR2 and SUR1, respectively. Results: We found that the pore-forming subunit of the sarcolemmal KATP channel (Kir6.2) was expressed in iPSC and maintained throughout the course of differentiation. Consistent with the typical composition of sarcolemmal KATP, we observe a significant increase of SUR2 but little SUR1 protein following Wnt inhibition. Functionally, the FPD is markedly reduced by P1075 in a concentration-dependent manner, with 24% reduction at 100 nM and 92 % reduction at 100 μM. Moreover, glibenclamide 10μM reduces FPD shortening confirming a role for KATP. Finally, we observe little change in FPD when cells are exposed to diazoxide (100 μM) consistent with reduced SUR1 protein levels. Conclusion: These results indicate that cardiomyocytes derived from human iPSC express the KATP channel composed of primarily the SUR2 isoform and suggest that iPSC derived cardiomyocytes would be an effective model for studying the role of KATP during metabolic challenges.

cADP-ribose activates reconstituted ryanodine receptors from coronary arterial smooth muscle

2001 ◽  
Vol 280 (1) ◽  
pp. H208-H215 ◽  
Author(s):  
Pin-Lan Li ◽  
Wang-Xian Tang ◽  
Hector H. Valdivia ◽  
Ai-Ping Zou ◽  
William B. Campbell
Keyword(s):  
Smooth Muscle ◽  
Lipid Bilayers ◽  
Ryanodine Receptors ◽  
Fold Increase ◽  
Ruthenium Red ◽  
Dependent Manner ◽  
High Concentration ◽  
Open Probability ◽  
Arterial Smooth Muscle ◽  
Concentration Dependent Manner

The present study was designed to test the hypothesis that cADP-ribose (cADPR) increases Ca2+release through activation of ryanodine receptors (RYR) on the sarcoplasmic reticulum (SR) in coronary arterial smooth muscle cells (CASMCs). We reconstituted RYR from the SR of CASMCs into planar lipid bilayers and examined the effect of cADPR on the activity of these Ca2+ release channels. In a symmetrical cesium methanesulfonate configuration, a 245 pS Cs+ current was recorded. This current was characterized by the formation of a subconductance and increase in the open probability (NPo) of the channels in the presence of ryanodine (0.01–1 μM) and imperatoxin A (100 nM). A high concentration of ryanodine (50 μM) and ruthenium red (40–80 μM) substantially inhibited the activity of RYR/Ca2+ release channels. Caffeine (0.5–5 mM) markedly increased the NPo of these Ca2+release channels of the SR, but d- myo-inositol 1,4,5-trisphospate and heparin were without effect. Cyclic ADPR significantly increased the NPo of these Ca2+release channels of SR in a concentration-dependent manner. Addition of cADPR (0.01 μM) into the cis bath solution produced a 2.9-fold increase in the NPo of these RYR/Ca2+release channels. An eightfold increase in the NPo of the RYR/Ca2+ release channels (0.0056 ± 0.001 vs. 0.048 ± 0.017) was observed at a concentration of cADPR of 1 μM. The effect of cADPR was completely abolished by ryanodine (50 μM). In the presence of cADPR, Ca2+-induced activation of these channels was markedly enhanced. These results provide evidence that cADPR activates RYR/Ca2+ release channels on the SR of CASMCs. It is concluded that cADPR stimulates Ca2+ release through the activation of RYRs on the SR of these smooth mucle cells.

Alpha 1-adrenoceptor-mediated phosphoinositide breakdown and inotropic responses in diabetic hearts

1991 ◽  
Vol 260 (2) ◽  
pp. H557-H562 ◽  
Author(s):  
H. Xiang ◽  
J. H. McNeill
Keyword(s):  
Positive Inotropic Effect ◽  
Binding Assay ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Protein Binding Assay ◽  
Rat Hearts ◽  
Induced Changes ◽  
Inotropic Responses

The mechanism(s) involved in diabetes-induced changes in the heart is still unclear, but one defect appears to occur in the alpha 1-adrenoceptor system. We evaluated the possibility that the changes in the inotropic responsiveness to alpha 1-adrenoceptor stimulation in streptozotocin-diabetic rat hearts may be linked to altered phosphoinositide turnover. Stimulation of alpha 1-adrenoceptor by norepinephrine (in the presence of propranolol) in right ventricles resulted in the formation of D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] [measured with an Ins(1,4,5)P3 protein binding assay kit] in a time- and concentration-dependent manner in both control and diabetic rats. The increase in Ins(1,4,5)P3 preceded the increase in the norepinephrine-mediated positive inotropic effect. Diabetic hearts showed a greater maximum inotropic response to norepinephrine stimulation and also had higher Ins(1,4,5)P3 levels. These observations suggest that the changes in Ins(1,4,5)P3 levels may be implicated in the increased inotropic responsiveness to alpha 1-adrenoceptor stimulation in diabetic hearts. Ca2+ overload, induced by Ins(1,4,5)P3, could further be involved in the development of diabetic cardiomyopathy.

scholarly journals The Role of Nrf2 Signaling in PPARβ/δ-Mediated Vascular Protection against Hyperglycemia-Induced Oxidative Stress

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Rosario Jimenez ◽  
Marta Toral ◽  
Manuel Gómez-Guzmán ◽  
Miguel Romero ◽  
Manuel Sanchez ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
High Glucose ◽  
Vascular Complications ◽  
Diabetic Rats ◽  
Heme Oxygenase 1 ◽  
Peroxisome Proliferator ◽  
Related Factor ◽  
Dependent Manner ◽  
Vascular Protection ◽  
Concentration Dependent Manner

Hyperglycemia induces oxidative stress and plays a substantial role in the progression of vascular diseases. Here, we demonstrated the potentiality of peroxisome proliferator-activated receptor (PPAR)β/δ activation in attenuating high glucose-induced oxidative stress in endothelial cells and diabetic rats, pointing to the involvement of nuclear factor erythroid 2-related factor 2 (Nrf2). HUVECs exposed to high glucose showed increased levels of reactive oxygen species (ROS) and upregulated NOX-2, NOX-4, Nrf2, and NQO-1 effects that were significantly reversed by the PPARβ/δ agonists GW0742 and L165041. Both PPARβ/δ agonists, in a concentration-dependent manner, induced transcriptional and protein upregulation of heme oxygenase-1 (HO-1) under low- and high-glucose conditions. All effects of PPARβ/δ agonists were reversed by either pharmacological inhibition or siRNA-based downregulation of PPARβ/δ. These in vitro findings were confirmed in diabetic rats treated with GW0742. In conclusion, PPARβ/δ activation confers vascular protection against hyperglycemia-induced oxidative stress by suppressing NOX-2 and NOX-4 expression plus a direct induction of HO-1; with the subsequent downregulation of the Nrf2 pathway. Thus, PPARβ/δ activation could be of interest to prevent the progression of diabetic vascular complications.

scholarly journals B7-H4 Expression is Upregulated by PKCδ Activation and Contributes to PKCδ-Induced Cell Mobility in Colorectal Cancer

2021 ◽  
Author(s):  
Bin Zhou ◽  
Youwei Lu ◽  
Zhiming Zhao ◽  
Tongguo Shi ◽  
Hongya Wu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Expression Patterns ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Colorectal Tumour ◽  
Protein Levels ◽  
Cell Mobility ◽  
Unknown Protein ◽  
Poor Differentiation

Abstract Background B7-H4 is overexpressed in colorectal cancer (CRC) and plays important roles in tumour growth and immunosuppression. However, the exact mechanism that regulates B7-H4 expression remains largely unknown. Protein kinase δ (PKCδ) plays a significant role in a range of cancers, including CRC. Here, we investigated whether PKCδ regulates the expression of B7-H4 in CRC.Methods By using immunohistochemical and immunofluorescence (IF) staining, we analysed the expression of B7-H4 and phospho-PKCδ (p-PKCδ) in 225 colorectal tumour samples, and the clinical significance of these expression patterns was determined. In vitro experiments were performed with the CRC cell lines HCT116 and SW620 to detect the effect of PKCδ activation on B7-H4 expression.Results B7-H4 expression was significantly correlated with p-PKCδ expression (r=0.378, P<0.001) in tumour tissues. The co-expression of p-PKCδ and B7-H4 was significantly associ­ated with moderate/poor differentiation (P=0.024), lymph node metastasis (P=0.001) and an advanced Dukes’ stage (P=0.002). Western blot analysis showed that TPA increased B7-H4 levels in a concentration-dependent manner and rottlerin also abrogated TPA-induced B7-H4 enhancement. The expression of B7-H4 and p-STAT3 were significantly reduced by PKCδ-specific siRNA. Moreover, STAT3 inhibitor cryptotanshinone significantly decreased B7-H4 protein levels in HCT116 cells. Knockdown of B7-H4 or PKCδ expression suppressed cell migration and mobility.Conclusion B7-H4 expression was significantly correlated with p-PKCδ expression in CRC samples. B7-H4 expression was upregulated by STAT3 activation via PKCδ and played roles in PKCδ-induced cancer cell mobility and metastasis.

scholarly journals Procyanidin B2 Alleviates Palmitic Acid-Induced Injury in HepG2 Cells via Endoplasmic Reticulum Stress Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yi-Ming Li ◽  
Shao-Yang Zhao ◽  
Huan-Huan Zhao ◽  
Bao-Hua Wang ◽  
Sai-Mei Li
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Er Stress ◽  
Hepg2 Cells ◽  
Cellular Injury ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Protein Levels ◽  
Caspase 1 ◽  
The Metabolic Syndrome

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome featuring ectopic lipid accumulation in hepatocytes. NAFLD has been a severe threat to humans with a global prevalence of over 25% yet no approved drugs for the treatment to date. Previous studies showed that procyanidin B2 (PCB2), an active ingredient from herbal cinnamon, has an excellent hepatoprotective effect; however, the mechanism remains inconclusive. The present study aimed to investigate the protective effect and underlying mechanism of PCB2 on PA-induced cellular injury in human hepatoma HepG2 cells. Our results showed that PA-induced oxidative stress, calcium disequilibrium, and subsequent endoplasmic reticulum stress (ERS) mediated cellular injury, with elevated protein levels of GRP78, GRP94, CHOP, and hyperphosphorylation of PERK and IRE1α as well as the increased ratio of Bax/Bcl-2, which was restored by PCB2 in a concentration-dependent manner, proving the excellent antiapoptosis effect. In addition, 4-phenylbutyric acid (4-PBA), the ER stress inhibitor, increased cell viability and decreased protein levels of GRP78 and CHOP, which is similar to PCB2, and thapsigargin (TG), the ER stress agonist, exhibited conversely meanwhile partly counteracted the hepatic protection of PCB2. What is more, upregulated protein expression of p-IKKα/β, p-NF-κB p65, NLRP3, cleaved caspase 1, and mature IL-1β occurred in HepG2 cells in response to PA stress while rescued with the PCB2 intervention. In conclusion, our study demonstrated that PA induces ERS in HepG2 cells and subsequently activates downstream NLRP3 inflammasome-mediated cellular injury, while PCB2 inhibits NLRP3/caspase 1/IL-1β pathway, inflammation, and apoptosis with the presence of ERS, thereby promoting cell survival, which may provide pharmacological evidence for clinical approaches on NAFLD.

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