scholarly journals High glucose suppresses autophagy through the AMPK pathway while it induces autophagy via oxidative stress in chondrocytes

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Ben Wang ◽  
Yifeng Shi ◽  
Jiaoxiang Chen ◽  
Zhenxuan Shao ◽  
Libin Ni ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
High Glucose ◽  
Combined Treatment ◽  
Dependent Manner ◽  
Pathological Features ◽  
Ampk Signaling ◽  
Ampk Pathway ◽  
Osteoarthritis Progression ◽  
Underlying Mechanisms ◽  
Dose Dependent

AbstractDiabetes (DB) is a risk factor for osteoarthritis progression. High glucose (HG) is one of the key pathological features of DB and has been demonstrated to induce apoptosis and senescence in chondrocytes. Autophagy is an endogenous mechanism that can protect cells against apoptosis and senescence. The effects of HG on autophagy in cells including chondrocytes have been studied; however, the results have been inconsistent. The current study aimed to elucidate the underlying mechanisms, which could be associated with the contrasting outcomes. The present study revealed that HG can induce apoptosis and senescence in chondrocytes, in addition to regulating autophagy dynamically. The present study demonstrated that HG can cause oxidative stress in chondrocytes and suppress the AMPK pathway in a dose-dependent manner. Elimination of oxidative stress by Acetylcysteine, also called N-acetyl cysteine (NAC), downregulated autophagy and alleviated HG-stimulated apoptosis and senescence, while activation of the AMPK signaling pathway by AICAR not only upregulated autophagy but also alleviated HG-stimulated apoptosis and senescence. A combined treatment of NAC and AICAR was superior to treatment with either NAC or AICAR. The study has demonstrated that HG can suppress autophagy through the AMPK pathway and induce autophagy via oxidative stress in chondrocytes.

scholarly journals Genipin and Insulin Combined Treatment Improves Implant Osseointegration in Type 2 Diabetic Rats

2020 ◽  
Author(s):  
Jiajia Zhang ◽  
Ya-nan Wang ◽  
Tingting Jia ◽  
Haiyun Huang ◽  
Dongjiao Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Combined Treatment ◽  
Harmful Effect ◽  
Diabetic Rats ◽  
Control Group ◽  
Ampk Signaling ◽  
Glucose Levels ◽  
Negative Effect ◽  
Underlying Mechanisms

Abstract Background: Type 2 diabetes mellitus (T2DM) has a harmful effect on the stability and osseointegration of dental implants. T2DM induces mitochondrial damage by inhibiting AMPK signaling, resulting in oxidative stress and poor osteogenesis in the peri-implant bone area. Genipin is a major component of gardenia fruits with strong antioxidant, anti-inflammation, and anti-diabetic actions, and it also can activate mitochondrial quality control via the AMPK pathway. The purpose of this study was to investigate the effects of genipin and insulin treatment on implant osseointegration in T2DM rats and explore the underlying mechanisms. Methods: Streptozotocin-induced diabetic rats received implant surgery in their femurs, and were then assigned to five groups that were subjected to different treatments for three months: control group, T2DM group, insulin-treated T2DM group (10 IU/kg), genipin-treated T2DM group (50 mg/kg), and the genipin and insulin combination-treated T2DM group. Then, we regularly assessed the weight and glucose levels of the animals. Rats were euthanized at three months after the implantation procedure, and the femora were harvested for microscopic computerized tomography analysis, biomechanical tests, and different histomorphometric assessment. Results: The results indicated that the highest blood glucose and oxidative stress levels were measured for the T2DM group, resulting in the poorest osseointegration. The combination-treated T2DM group mitigated hyperglycemia and normalized, reactivated AMPK signaling, and alleviated oxidative stress as well as reversed the negative effect of osseointegration. There were beneficial changes observed in the T2DM-genipin and T2DM-insulin groups, but these were less in comparison to the combination treatment group. Conclusion: Our study suggests that treatment with genipin in combination with insulin could be an effective method for promoting implant osseointegration in T2DM rats, which may be related to AMPK signaling.

scholarly journals Genipin and insulin combined treatment improves implant osseointegration in type 2 diabetic rats

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jiajia Zhang ◽  
Ya-nan Wang ◽  
Tingting Jia ◽  
Haiyun Huang ◽  
Dongjiao Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Combined Treatment ◽  
Harmful Effect ◽  
Diabetic Rats ◽  
Control Group ◽  
Ampk Signaling ◽  
Glucose Levels ◽  
Negative Effect ◽  
Underlying Mechanisms

Abstract Background Type 2 diabetes mellitus (T2DM) has a harmful effect on the stability and osseointegration of dental implants. T2DM induces mitochondrial damage by inhibiting AMPK signaling, resulting in oxidative stress and poor osteogenesis in the peri-implant bone area. Genipin is a major component of gardenia fruits with strong antioxidant, anti-inflammation, and antidiabetic actions, and it also can activate mitochondrial quality control via the AMPK pathway. The purpose of this study was to investigate the effects of genipin and insulin treatment on implant osseointegration in T2DM rats and explore the underlying mechanisms. Methods Streptozotocin-induced diabetic rats received implant surgery in their femurs and were then assigned to five groups that were subjected to different treatments for three months: control group, T2DM group, insulin-treated T2DM group (10 IU/kg), genipin-treated T2DM group (50 mg/kg), and the genipin and insulin combination-treated T2DM group. Then, we regularly assessed the weight and glucose levels of the animals. Rats were euthanized at 3 months after the implantation procedure, and the femora were harvested for microscopic computerized tomography analysis, biomechanical tests, and different histomorphometric assessment. Results The results indicated that the highest blood glucose and oxidative stress levels were measured for the T2DM group, resulting in the poorest osseointegration. The combination-treated T2DM group mitigated hyperglycemia and normalized, reactivated AMPK signaling, and alleviated oxidative stress as well as reversed the negative effect of osseointegration. There were beneficial changes observed in the T2DM-genipin and T2DM-insulin groups, but these were less in comparison to the combination treatment group. Conclusion Our study suggests that treatment with genipin in combination with insulin could be an effective method for promoting implant osseointegration in T2DM rats, which may be related to AMPK signaling.

Polydatin Attenuates Carbachol-induced Contraction of Guinea Pig Gallbladder

2019 ◽  
Vol 18 (1) ◽  
pp. 34-38
Author(s):  
Chen Lei ◽  
Pan Xiang ◽  
Shen Yonggang ◽  
Song Kai ◽  
Zhong Xingguo ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Guinea Pig ◽  
Smooth Muscles ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Cyclic Guanosine Monophosphate ◽  
Guanosine Monophosphate ◽  
Dependent Manner ◽  
Underlying Mechanisms ◽  
Dose Dependent

The aim of this study was to determine whether polydatin, a glucoside of resveratrol isolated from the root of Polygonum cuspidatum, warranted development as a potential therapeutic for ameliorating the pain originating from gallbladder spasm disorders and the underlying mechanisms. Guinea pig gallbladder smooth muscles were treated with polydatin and specific inhibitors to explore the mechanisms underpinning polydatin-induced relaxation of carbachol-precontracted guinea pig gallbladder. Our results shown that polydatin relaxed carbachol-induced contraction in a dose-dependent manner through the nitric oxide/cyclic guanosine monophosphate/protein kinase G and the cyclic adenosine monophosphate/protein kinase A signaling pathways as well as the myosin light chain kinase and potassium channels. Our findings suggested that there was value in further exploring the potential therapeutic use of polydatin in gallbladder spasm disorders.

scholarly journals Cardiac Remodeling Induced by All-Trans Retinoic Acid is Detrimental in Normal Rats

2017 ◽  
Vol 43 (4) ◽  
pp. 1449-1459 ◽  
Author(s):  
Renata A. C. Silva ◽  
Andréa F. Gonçalves ◽  
Priscila P. dos Santos ◽  
Bruna Rafacho ◽  
Renan F. T. Claro ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Retinoic Acid ◽  
Energy Metabolism ◽  
Cardiac Remodeling ◽  
Citrate Synthase ◽  
Isolated Heart ◽  
Lipid Hydroperoxide ◽  
Dependent Manner ◽  
Heart Study ◽  
Dose Dependent

Background/Aims: This study aimed to discern whether the cardiac alterations caused by retinoic acid (RA) in normal adult rats are physiologic or pathologic. Methods and Results: Wistar rats were assigned into four groups: control animals (C, n = 20) received a standard rat chow; animals fed a diet supplemented with 0.3 mg/kg/day all-trans-RA (AR1, n = 20); animals fed a diet supplemented with 5 mg/kg/day all-trans-RA (AR2, n = 20); and animals fed a diet supplemented with 10 mg/kg/day all-trans-RA (AR3, n = 20). After 2 months, the animals were submitted to echocardiogram, isolated heart study, histology, energy metabolism status, oxidative stress condition, and the signaling pathway involved in the cardiac remodeling induced by RA. RA increased myocyte cross-sectional area in a dose-dependent manner. The treatment did not change the morphological and functional variables, assessed by echocardiogram and isolated heart study. In contrast, RA changed catalases, superoxide dismutase, and glutathione peroxidases and was associated with increased values of lipid hydroperoxide, suggesting oxidative stress. RA also reduced citrate synthase, enzymatic mitochondrial complex II, ATP synthase, and enzymes of fatty acid metabolism and was associated with increased enzymes involved in glucose use. In addition, RA increased JNK 1/2 expression, without changes in TGF-β, PI3K, AKT, NFκB, S6K, and ERK. Conclusion: In normal rats, RA induces cardiac hypertrophy in a dose-dependent manner. The non-participation of the PI3K/Akt pathway, associated with the participation of the JNK pathway, oxidative stress, and changes in energy metabolism, suggests that cardiac remodeling induced by RA supplementation is deleterious.

scholarly journals Oxidative stress increases megalin expression in the renal proximal tubules during the normoalbuminuric stage of diabetes mellitus

2018 ◽  
Vol 314 (3) ◽  
pp. F462-F470 ◽  
Author(s):  
Yoshifumi Kurosaki ◽  
Akemi Imoto ◽  
Fumitaka Kawakami ◽  
Masanori Yokoba ◽  
Tsuneo Takenaka ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetes Mellitus ◽  
Hydrogen Peroxide ◽  
High Glucose ◽  
Renal Cortex ◽  
Dependent Manner ◽  
Phosphatidylinositol 3 Kinase ◽  
Phosphorylated Akt ◽  
Stress Dependent ◽  
Phosphatidylinositol 3

Megalin, an endocytic receptor expressed in proximal tubule cells, plays a critical role in renal tubular protein reabsorption and is associated with the albuminuria observed in diabetic nephropathy. We have previously reported increased oxidant production in the renal cortex during the normoalbuminuric stage of diabetes mellitus (DM); however, the relationship between oxidative stress and renal megalin expression during the normoalbuminuric stage of DM remains unclear. In the present study, we evaluated whether oxidative stress affects megalin expression in the normoalbuminuric stage of DM in a streptozotocin-induced diabetic rat model and in immortalized human proximal tubular cells (HK-2). We demonstrated that increased expression of renal megalin accompanies oxidative stress during the early stage of DM, before albuminuria development. Telmisartan treatment prevented the diabetes-induced elevation in megalin level, possibly through an oxidative stress-dependent mechanism. In HK-2 cells, hydrogen peroxide significantly increased megalin levels in a dose- and time-dependent manner; however, the elevation in megalin expression was decreased following prolonged exposure to severe oxidative stress induced by 0.4 mmol/l hydrogen peroxide. High-glucose treatment also significantly increased megalin expression in HK-2 cells. Concurrent administration of the antioxidant N-acetyl-cysteine blocked the effects of high glucose on megalin expression. Furthermore, the hydrogen peroxide-induced increase in megalin expression was blocked by treatment with phosphatidylinositol 3-kinase and Akt inhibitors. Increase of phosphorylated Akt expression was also seen in the renal cortex of diabetic rats. Taken together, our results indicate that mild oxidative stress increases renal megalin expression through the phosphatidylinositol 3-kinase-Akt pathway in the normoalbuminuric stage of DM.

scholarly journals Preclinical Study on the Ameliorating Effect of L-Ascorbic Acid for the Oxidative Stress of Caused by Chronic Administration of Organic Nitrates in Cardiovascular Diseases

2021 ◽  
Author(s):  
Ahmed M Hamdan ◽  
Zuhair M. Mohammedsaleh ◽  
Aalaa Aboelnour ◽  
Sherif M.H. Elkhannishi
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Ascorbic Acid ◽  
Chronic Administration ◽  
Stress Factors ◽  
Male Rats ◽  
Oxidative Stress Marker ◽  
Organic Nitrates ◽  
Dependent Manner ◽  
Dose Dependent

Abstract PurposeThe therapeutic activity of Glyceryl trinitrate (GTN) is mainly regulated by liberating nitric oxide (NO) and reactive nitrogen species (RNS). During this biotransformation, oxidative stress and lipid peroxidation inside the red blood cells (RBCs) occur. The principal objective of our research is to explain the ameliorating effect of L-ascorbic acid for the deleterious effects of chronic administration of nitrovasodilator drugs. MethodsWe studied some biochemical parameters for the oxidative stress using groups of high sucrose/fat (HSF) diet Wistar male rats chronically orally administered ISMN. Afterwards, we evaluated the role of L-ascorbic acid against these biochemical changes. ResultsChronic treatment with organic nitrates caused elevated serum levels of lipid peroxidation, hemoglobin derivatives as methemoglobin and carboxyhemoglobin, rate of hemoglobin autoxidation, the cellular levels of pro-inflammatory cytokines marker (NF-κB) and apoptosis markers (caspase-3) in myocardium muscles in a dose dependent manner. Meanwhile, such exposure caused decline in the enzymatic effect of superoxide dismutase (SOD), glutathione (GSH) and catalase activity (CAT) accompanied with a decrease of in the level of mitochondrial oxidative stress marker (nrf2) in myocardium muscles and decrease in the serum iron and total iron binding capacity (TIBC) in a dose dependent manner. Concomitant treatment with L-ascorbic acid significantly diminished these changes for all examined parameters.ConclusionChronic administration of organic nitrates leads to the alteration of the level of oxidative stress factors in the myocardium tissue due to generation of reactive oxygen species. Using vitamin C can effectively ameliorate such intoxication to overcome the nitrate tolerance.

scholarly journals AGEs and Glucose Levels Modulate Type I and III Procollagen mRNA Synthesis in Dermal Fibroblasts Cells Culture

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
Serban Iren Andreea ◽  
Costache Marieta ◽  
Dinischiotu Anca
Keyword(s):  
Extracellular Matrix ◽  
High Glucose ◽  
Dermal Fibroblasts ◽  
Type I ◽  
Dependent Manner ◽  
Human Dermal Fibroblasts ◽  
Mrna Synthesis ◽  
Quantitative Real Time Pcr ◽  
Glucose Levels ◽  
Dose Dependent

In the dermis, fibroblasts play an important role in the turnover of the dermal extracellular matrix. Collagen I and III, the most important dermal proteins of the extracellular matrix, are progressively altered during ageing and diabetes. For mimicking diabetic conditions, the cultured human dermal fibroblasts were incubated with increasing amounts of AGE-modified BSA andD-glucose for 24 hours. The expression of procollagenα2(I) and procollagenα1(III) mRNA was analyzed by quantitative real-time PCR. Our data revealed that the treatment of fibroblasts with AGE-modified BSA upregulated the expression of procollagenα2(I) and procollagenα1(III) mRNA in a dose-dependent manner. High glucose levels mildly induced a profibrogenic pattern, increasing the procollagenα2(I) mRNA expression whereas there was a downregulation tendency of procollagenα1(III) mRNA.

scholarly journals p-Coumaric Acid Protects Human Lens Epithelial Cells against Oxidative Stress-Induced Apoptosis by MAPK Signaling

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Jiao Peng ◽  
Ting-ting Zheng ◽  
Yue Liang ◽  
Li-fang Duan ◽  
Yao-dong Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Mapk Signaling ◽  
Human Lens ◽  
Lens Epithelial Cells ◽  
Dependent Manner ◽  
Coumaric Acid ◽  
Underlying Mechanisms ◽  
Induced Apoptosis

To protect against oxidative stress-induced apoptosis in lens epithelial cells is a potential strategy in preventing cataract formation. The present study aimed at studying the protective effect and underlying mechanisms of p-coumaric acid (p-CA) on hydrogen peroxide- (H2O2-) induced apoptosis in human lens epithelial (HLE) cells (SRA 01–04). Cells were pretreated with p-CA at a concentration of 3, 10, and 30 μM before the treatment of H2O2 (275 μM). Results showed that pretreatment with p-CA significantly protected against H2O2-induced cell death in a dose-dependent manner, as well as downregulating the expressions of both cleaved caspase-3 and cleaved caspase-9 in HLE cells. Moreover, p-CA also greatly suppressed H2O2-induced intracellular ROS production and mitochondrial membrane potential loss and elevated the activities of T-SOD, CAT, and GSH-Px of H2O2-treated cells. As well, in vitro study showed that p-CA also suppressed H2O2-induced phosphorylation of p-38, ERK, and JNK in HLE cells. These findings demonstrate that p-CA suppresses H2O2-induced HLE cell apoptosis through modulating MAPK signaling pathways and suggest that p-CA has a potential therapeutic role in the prevention of cataract.

Oxidative stress biomarkers in the gills of the bivalve Mactra stultorum exposed to acrylamide

2020 ◽  
Vol 84 (2) ◽  
Author(s):  
Wafa Trabelsi ◽  
Chaima Fouzai ◽  
Imene Chetoui ◽  
Safa Bejaoui ◽  
Khaoula Telahigue ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ache Activity ◽  
Reduced Glutathione ◽  
Lipid Hydroperoxides ◽  
Dependent Manner ◽  
Advanced Oxidation Protein Products ◽  
Oxidative Stress Biomarkers ◽  
Stress Biomarkers ◽  
The Subject ◽  
Dose Dependent

Acrylamide (ACR) is among the most deleterious pollutants in the environment and presents a serious risk to humans and ecosystems. The purpose of this study was to assess its effects when administered at different concentrations (5, 10 and 20 mg L–1) to evaluate antioxidant status in the gills of Mactra stultorum. Our results showed, after five days of treat­ment, an increase in malondialdehyde (MDA), lipid hydroperoxides (LOOH), advanced oxidation protein products (AOPP), reduced glutathione (GSH), ascorbic acid (Vit C) and metallothionein (MDA) levels in gills of treated clams compared with controls. Moreover, an increase in superoxide dismutase (SOD) and a significant decrease in glutathione peroxidase (GPx) activities were also observed. Acrylamide induced neurotoxicity, as evidenced by the inhibition of acetylcholinesterase (AChE) activity in a dose-dependent manner. Overall, our results indicated that oxidative stress may be considered one of the mechanisms behind acrylamide toxicity in bivalves, although the subject requires more research.

Wheat germ-derived peptide ADWGGPLPH abolishes high glucose-induced oxidative stress via modulation of the PKCζ/AMPK/NOX4 pathway

2020 ◽  
Vol 11 (8) ◽  
pp. 6843-6854 ◽  
Author(s):  
Fang Wang ◽  
Zebin Weng ◽  
Yi Lyu ◽  
Yifan Bao ◽  
Juncheng Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
High Glucose ◽  
Wheat Germ ◽  
Muscle Cells ◽  
Antioxidative Effect ◽  
Underlying Mechanisms

This study explores the antioxidative effect of a specific wheat germ-derived peptide on high glucose-induced oxidative stress in vascular smooth muscle cells (VSMCs) and the underlying mechanisms.

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