scholarly journals Protective Mechanisms of Avocado Oil Extract Against Ototoxicity

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 947 ◽  
Author(s):  
Thu Nguyen Minh Pham ◽  
Seo Yeon Jeong ◽  
Do Hoon Kim ◽  
Yu Hwa Park ◽  
Jung Suk Lee ◽  
...  
Keyword(s):  
Glutathione Metabolism ◽  
Protective Mechanism ◽  
Autophagic Flux ◽  
Protective Mechanisms ◽  
Antioxidant Genes ◽  
Avocado Oil ◽  
Tnf Α ◽  
Antioxidant Gene Expression ◽  
Oil Extract ◽  
Inner Ear Damage

Despite the excellent antimicrobial activity of aminoglycoside antibiotics, permanent inner ear damage associated with the use of these drugs has resulted in the need to develop strategies to address the ototoxic risk given their widespread use. In a previous study, we showed that avocado oil protects ear hair cells from damage caused by neomycin. However, the detailed mechanism by which this protection occurs is still unclear. Here, we investigated the auditory cell-protective mechanism of enhanced functional avocado oil extract (DKB122). RNA sequencing followed by pathway analysis revealed that DKB122 has the potential to enhance the expression of detoxification and antioxidant genes associated with glutathione metabolism (Hmox4, Gsta4, Mgst1, and Abcc3) in HEI-OC1 cells. Additionally, DKB122 effectively decreased ROS levels, resulting in the inhibition of apoptosis in HEI-OC1 cells. The expression of the inflammatory genes that encode chemokines and interleukins was also downregulated by DKB122 treatment. Consistent with these results, DKB122 significantly inhibited p65 nuclear migration induced by TNF-α or LPS in HEI-OC1 cells and THP-1 cells and the expression of inflammatory chemokine and interleukin genes induced by TNF-α was significantly reduced. Moreover, DKB122 treatment increased LC3-II and decreased p62 in HEI-OC1 cells, suggesting that DKB122 increases autophagic flux. These results suggest that DKB122 has otoprotective effects attributable to its antioxidant activity, induction of antioxidant gene expression, anti-inflammatory activity, and autophagy activation.

TNF-α Suppresses Autophagic Flux in Acinar Cells in IgG4-Related Sialadenitis

2019 ◽  
Vol 98 (12) ◽  
pp. 1386-1396 ◽  
Author(s):  
X. Hong ◽  
S.N. Min ◽  
Y.Y. Zhang ◽  
Y.T. Lin ◽  
F. Wang ◽  
...  
Keyword(s):  
Acinar Cell ◽  
Cell Injury ◽  
Ex Vivo ◽  
Secretory Granules ◽  
Acinar Cells ◽  
Autophagic Flux ◽  
C6 Cells ◽  
Tnf Α ◽  
Α Level

IgG4-related sialadenitis (IgG4-RS) is a newly recognized immune-mediated systemic fibroinflammatory disease that affects salivary glands and leads to hyposalivation. Tumor necrosis factor–α (TNF-α) is a critical proinflammatory cytokine involved in several salivary gland disorders, but its role and mechanism regarding acinar cell injury in IgG4-RS are unknown. Here, we found that TNF-α level was significantly increased in serum and submandibular gland (SMG) of patients and that serum TNF-α level was negatively correlated with saliva flow rate. Ultrastructural observations of IgG4-RS SMGs revealed accumulation of large autophagic vacuoles, as well as dense fibrous bundles, decreased secretory granules, widened intercellular spaces, swollen mitochondria, and expanded endoplasmic reticulum. Expression levels of LC3 and p62 were both increased in patients’ SMGs. TNF-α treatment led to elevated levels of LC3II and p62 in both SMG-C6 cells and cultured human SMG tissues but did not further increase their levels when combined with bafilomycin A1 treatment. Moreover, transfection of Ad-mCherry-GFP-LC3B in SMG-C6 cells confirmed the suppression of autophagic flux after TNF-α treatment. Immunofluorescence imaging revealed that costaining of LC3 and the lysosomal marker LAMP2 was significantly decreased in patients, TNF-α–treated SMG-C6 cells, and cultured human SMGs, indicating a reduction in autophagosome-lysosome fusion. Furthermore, the ratio of pro/mature cathepsin D was elevated in vivo, ex vivo, and in vitro. TNF-α also appeared to induce abnormal acidification of lysosomes in acinar cells, as assessed by lysosomal pH and LysoTracker DND-26 fluorescence intensity. In addition, TNF-α treatment induced transcription factor EB (TFEB) redistribution in SMG-C6 cells, which was consistent with the changes observed in IgG4-RS patients. TNF-α increased the phosphorylation of extracellular signal–regulated kinase (ERK) 1/2, and inhibition of ERK1/2 by U0126 reversed TNF-α–induced TFEB redistribution, lysosomal dysfunction, and autophagic flux suppression. These findings suggest that TNF-α is a key cytokine related to acinar cell injury in IgG4-RS through ERK1/2-mediated autophagic flux suppression.

scholarly journals Molecular Targets of Manganese-Induced Neurotoxicity: A Five-Year Update

2021 ◽  
Vol 22 (9) ◽  
pp. 4646
Author(s):  
Alexey A. Tinkov ◽  
Monica M. B. Paoliello ◽  
Aksana N. Mazilina ◽  
Anatoly V. Skalny ◽  
Airton C. Martins ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Mitochondrial Dysfunction ◽  
Synaptic Dysfunction ◽  
Future Research ◽  
Protective Mechanism ◽  
Autophagic Flux ◽  
Future Research Directions ◽  
The Impact

Understanding of the immediate mechanisms of Mn-induced neurotoxicity is rapidly evolving. We seek to provide a summary of recent findings in the field, with an emphasis to clarify existing gaps and future research directions. We provide, here, a brief review of pertinent discoveries related to Mn-induced neurotoxicity research from the last five years. Significant progress was achieved in understanding the role of Mn transporters, such as SLC39A14, SLC39A8, and SLC30A10, in the regulation of systemic and brain manganese handling. Genetic analysis identified multiple metabolic pathways that could be considered as Mn neurotoxicity targets, including oxidative stress, endoplasmic reticulum stress, apoptosis, neuroinflammation, cell signaling pathways, and interference with neurotransmitter metabolism, to name a few. Recent findings have also demonstrated the impact of Mn exposure on transcriptional regulation of these pathways. There is a significant role of autophagy as a protective mechanism against cytotoxic Mn neurotoxicity, yet also a role for Mn to induce autophagic flux itself and autophagic dysfunction under conditions of decreased Mn bioavailability. This ambivalent role may be at the crossroad of mitochondrial dysfunction, endoplasmic reticulum stress, and apoptosis. Yet very recent evidence suggests Mn can have toxic impacts below the no observed adverse effect of Mn-induced mitochondrial dysfunction. The impact of Mn exposure on supramolecular complexes SNARE and NLRP3 inflammasome greatly contributes to Mn-induced synaptic dysfunction and neuroinflammation, respectively. The aforementioned effects might be at least partially mediated by the impact of Mn on α-synuclein accumulation. In addition to Mn-induced synaptic dysfunction, impaired neurotransmission is shown to be mediated by the effects of Mn on neurotransmitter systems and their complex interplay. Although multiple novel mechanisms have been highlighted, additional studies are required to identify the critical targets of Mn-induced neurotoxicity.

scholarly journals Protective effects and mechanisms of high-dose vitamin C on sepsis-associated cognitive impairment in rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ning Zhang ◽  
Wei Zhao ◽  
Zhen-Jie Hu ◽  
Sheng-Mei Ge ◽  
Yan Huo ◽  
...  
Keyword(s):  
Vitamin C ◽  
Escape Latency ◽  
Morris Water Maze Test ◽  
Protective Mechanism ◽  
High Dose ◽  
Maze Test ◽  
Tnf Α ◽  
Histopathologic Changes ◽  
High Dose Vitamin ◽  
Necrosis Factor

AbstractSepsis survivors present long-term cognitive deficits. The present study was to investigate the effect of early administration of high-dose vitamin C on cognitive function in septic rats and explore its possible cerebral protective mechanism. Rat sepsis models were established by cecal ligation and puncture (CLP). Ten days after surgery, the Morris water maze test was performed to evaluate the behavior and cognitive function. Histopathologic changes in the hippocampus were evaluated by nissl staining. The inflammatory cytokines, activities of antioxidant enzymes (superoxide dismutase or SOD) and oxidative products (malondialdehyde or MDA) in the serum and hippocampus were tested 24 h after surgery. The activity of matrix metalloproteinase-9 (MMP-9) and expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1(HO-1) in the hippocampus were measured 24 h after surgery. Compared with the sham group in the Morris water maze test, the escape latency of sepsis rats was significantly (P = 0.001) prolonged in the navigation test, whereas the frequency to cross the platform and the time spent in the target quadrant were significantly (P = 0.003) reduced. High-dose vitamin C significantly decreased the escape latency (P = 0.01), but increased the time spent in the target quadrant (P = 0.04) and the frequency to cross the platform (P = 0.19). In the CLP+ saline group, the pyramidal neurons were reduced and distributed sparsely and disorderly, the levels of inflammatory cytokines of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 in the serum and hippocampus were significantly increased (P = 0.000), the blood brain barrier (BBB) permeability in the hippocampus was significantly (P = 0.000) increased, the activities of SOD in the serum and hippocampus were significantly (P = 0.000 and P = 0.03, respectively) diminished while the levels of MDA in the serum and hippocampus were significantly (P = 0.007) increased. High-dose vitamin C mitigated hippocampus histopathologic changes, reduced systemic inflammation and neuroinflammation, attenuated BBB disruption, inhibited oxidative stress in brain tissue, and up-regulated the expression of nuclear and total Nrf2 and HO-1. High-dose vitamin C significantly (P < 0.05) decreased the levels of tumor necrosis factor- (TNF)-α, interleukin-6 (IL-6), MDA in the serum and hippocampus, and the activity of MMP-9 in the hippocampus, but significantly (P < 0.05) increased the levels of SOD, the anti-inflammatory cytokine (IL-10) in the serum and hippocampus, and nuclear and total Nrf2, and HO-1 in the hippocampus. In conclusion, high-dose vitamin C can improve cognition impairment in septic rats, and the possible protective mechanism may be related to inhibition of inflammatory factors, alleviation of oxidative stress, and activation of the Nrf2/HO-1 pathway.

scholarly journals Cangrelor ameliorates CLP-induced pulmonary injury in sepsis by inhibiting GPR17

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Qiancheng Luo ◽  
Rui Liu ◽  
Kaili Qu ◽  
Guorong Liu ◽  
Min Hang ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Lavage Fluid ◽  
Surface Expression ◽  
Pulmonary Injury ◽  
Protective Mechanisms ◽  
Tnf Α ◽  
Anti Platelet Drug ◽  
G Protein Coupled ◽  
Very High ◽  
Masson Staining

Abstract Background Sepsis is a common complication of severe wound injury and infection, with a very high mortality rate. The P2Y12 receptor inhibitor, cangrelor, is an antagonist anti-platelet drug. Methods In our study, we investigated the protective mechanisms of cangrelor in CLP-induced pulmonary injury in sepsis, using C57BL/6 mouse models. Results TdT-mediated dUTP Nick-End Labeling (TUNEL) and Masson staining showed that apoptosis and fibrosis in lungs were alleviated by cangrelor treatment. Cangrelor significantly promoted surface expression of CD40L on platelets and inhibited CLP-induced neutrophils in Bronchoalveolar lavage fluid (BALF) (p < 0.001). We also found that cangrelor decreased the inflammatory response in the CLP mouse model and inhibited the expression of inflammatory cytokines, IL-1β (p  < 0.01), IL-6 (p < 0.05), and TNF-α (p < 0.001). Western blotting and RT-PCR showed that cangrelor inhibited the increased levels of G-protein-coupled receptor 17 (GPR17) induced by CLP (p < 0.001). Conclusion Our study indicated that cangrelor repressed the levels of GPR17, followed by a decrease in the inflammatory response and a rise of neutrophils in BALF, potentially reversing CLP-mediated pulmonary injury during sepsis.

An Insight into the Role of Apoptosis and Autophagy in Nitric Oxide–Induced Articular Chondrocyte Cell Death

Cartilage ◽  
2020 ◽  
pp. 194760352097676
Author(s):  
Ekkapol Akaraphutiporn ◽  
Takafumi Sunaga ◽  
Eugene C. Bwalya ◽  
Wang Yanlin ◽  
Mwale Carol ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cell Death ◽  
Western Blot ◽  
Cell Apoptosis ◽  
Molecular Mechanisms ◽  
Interleukin 1 ◽  
Chondrocyte Apoptosis ◽  
Protective Mechanism ◽  
Autophagic Flux ◽  
Qpcr Analysis

Objective To investigate the role and characterize the molecular mechanisms regulating apoptosis and autophagy in nitric oxide (NO)–induced chondrocyte cell death. Design Cell apoptosis and autophagy were evaluated in chondrocytes treated with sodium nitroprusside (SNP) combined with the presence or absence of interleukin-1 beta (IL-1β) and nutrient-deprived conditions. The concentration of nitrite was determined by Griess reaction. Activation of apoptosis and autophagy were determined by immunocytochemistry, Western blot, and quantitative real-time polymerase chain reaction (qPCR) analysis. Flow cytometry and MTT assay were used to assess cell viability. Results Cotreatment of chondrocytes with SNP and IL-1β under nutrient-deprived condition potentially enhanced the effect of NO-induced cell death. Immunocytochemistry, Western blot, and qPCR analysis indicated that treatment of chondrocytes with SNP significantly reduced autophagic activity, autophagic flux, and multiple autophagy-related (Atg) genes expression. These findings were associated with an increase in ERK, Akt, and mTOR phosphorylation, whereas autophagy induction through mTOR/p70S6K inhibition by rapamycin significantly suppressed NO-induced cell apoptosis. Furthermore, the cleavage of poly(ADP-ribose) polymerase (PARP) and caspase-3 activation in response to apoptosis was weakly detected. These results corresponded with a significant increase in apoptosis-inducing factor (AIF) expression, suggesting the involvement of the caspase-independent pathway. Conclusions These results demonstrate that in chondrocyte cultures with cells induced into an osteoarthritis state, NO inhibits autophagy and induces chondrocyte apoptosis mainly, but not completely through the caspase-independent pathway. Our data suggest that autophagy is a protective mechanism in the pathogenesis of osteoarthritis and could be proposed as a therapeutic target for degenerative joint diseases.

scholarly journals Effects of spaceflight on innate immune function and antioxidant gene expression

2009 ◽  
Vol 106 (6) ◽  
pp. 1935-1942 ◽  
Author(s):  
Farnaz P. Baqai ◽  
Daila S. Gridley ◽  
James M. Slater ◽  
Xian Luo-Owen ◽  
Louis S. Stodieck ◽  
...  
Keyword(s):  
Space Shuttle ◽  
Ex Vivo ◽  
Innate Immune ◽  
Oxygen Species ◽  
Bacterial Product ◽  
Th1 Response ◽  
Antioxidant Gene ◽  
Tnf Α ◽  
Antioxidant Gene Expression ◽  
Cell Mitogen

Spaceflight conditions have a significant impact on a number of physiological functions due to psychological stress, radiation, and reduced gravity. To explore the effect of the flight environment on immunity, C57BL/6NTac mice were flown on a 13-day space shuttle mission (STS-118). In response to flight, animals had a reduction in liver, spleen, and thymus masses compared with ground (GRD) controls ( P < 0.005). Splenic lymphocyte, monocyte/macrophage, and granulocyte counts were significantly reduced in the flight (FLT) mice ( P < 0.05). Although spontaneous blastogenesis of splenocytes in FLT mice was increased, response to lipopolysaccharide (LPS), a B-cell mitogen derived from Escherichia coli, was decreased compared with GRD mice ( P < 0.05). Secretion of IL-6 and IL-10, but not TNF-α, by LPS-stimulated splenocytes was increased in FLT mice ( P < 0.05). Finally, many of the genes responsible for scavenging reactive oxygen species were upregulated after flight. These data indicate that exposure to the spaceflight environment can increase anti-inflammatory mechanisms and change the ex vivo response to LPS, a bacterial product associated with septic shock and a prominent Th1 response.

scholarly journals The protective mechanism of Ginkgolides and Ginkgo flavonoids on the TNF-α induced apoptosis of rat hippocampal neurons and its mechanisms in vitro

Heliyon ◽  
2015 ◽  
Vol 1 (1) ◽  
pp. e00020 ◽  
Author(s):  
Maojuan Guo ◽  
Yanrong Suo ◽  
Qing Gao ◽  
Huan Du ◽  
Wenyun Zeng ◽  
...  
Keyword(s):  
Hippocampal Neurons ◽  
Protective Mechanism ◽  
Tnf Α ◽  
Induced Apoptosis

Abstract 266: Autophagy Reverses Intramuscular Lipid Accumulation in Myocytes

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Truong N Lam ◽  
Romain Harmancey ◽  
Heinrich Taegtmeyer
Keyword(s):  
Fatty Acids ◽  
Cell Death ◽  
Lipid Accumulation ◽  
Protective Mechanism ◽  
Autophagic Flux ◽  
Protein Markers ◽  
Failing Heart ◽  
Intracellular Lipid Accumulation ◽  
Intramuscular Lipid ◽  
L6 Myocytes

Autophagy, or “self-eating” of the cell, is a tightly regulated “housekeeping” process involved in the degradation and recycling of protein aggregates and damaged organelles. In the failing heart, autophagy has been shown to be an adaptive response. We have previously demonstrated that a common feature of non-ischemic heart failure is lipid accumulation, which in excess can mediate cardiac dysfunction via lipotoxicity. Since autophagy mediates the clearance of lipids through a specific process, known as lipophagy, in hepatocytes, we wondered whether the activation of autophagy in the failing heart protects myocyte from lipotoxicity. To test this hypothesis, L6 myocytes were incubated over a period of 6 days with long chain fatty acids, either 0.5mM or 1.0mM fatty acids (equimolar mixture of oleate and palmitate). On the sixth day of treatment, an autophagic inhibitor (bafilomycin A1, 200nM) or autophagic activator (rapamycin, 1uM) was added to the cell culture medium for 24 hours. Intracellular triglyceride (TG) accumulation was measured in the cells using enzyme quantification assay as well as Oil Red O stain. Immunoblotting was also performed on protein markers to confirm autophagic flux (LC3 and P62) and cell death (Caspase3) in the myocytes. The results indicated that increasing concentrations of fatty acids gradually increased intracellular TG accumulation. Inhibition of autophagy using bafilomycin increased this effect whereas activation of autophagy using rapamycin reduced lipid accumulation in the L6 myocytes. Moreover, fatty acid mediated cell death was increased when autophagy is inhibited. We conclude that autophagy promotes the clearance of lipids from cultured myocytes. These findings suggest that lipophagy may be a protective mechanism in the myocyte through the decrease and reversal of intracellular lipid accumulation.

scholarly journals Comparative Transcriptome Analysis Reveals the Protective Mechanism of Glycyrrhinic Acid for Deoxynivalenol-Induced Inflammation and Apoptosis in IPEC-J2 Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiaoxiang Xu ◽  
Guorong Yan ◽  
Juan Chang ◽  
Ping Wang ◽  
Qingqiang Yin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Transcriptome Analysis ◽  
Animal Feed ◽  
Control Group ◽  
Protective Mechanism ◽  
Dependent Manner ◽  
Gene Expressions ◽  
Lactate Dehydrogenase Release ◽  
Tnf Α

Deoxynivalenol (DON) is the most common mycotoxin that frequently contaminates human food and animal feed, resulting in intestinal diseases and systemic immunosuppression. Glycyrrhinic acid (GA) exhibits various pharmacological activities. To investigate the protective mechanism of GA for DON-induced inflammation and apoptosis in IPEC-J2 cells, RNA-seq analysis was used in the current study. The IPEC-J2 cells were treated with the control group (CON), 0.5 μg/mL DON, 400 μg/mL GA, and 400 μg/mL GA+0.5 μg/mL DON (GAD) for 6 h. Results showed that 0.5 μg/mL DON exposure for 6 h could induce oxidative stress, inflammation, and apoptosis in IPEC-J2 cells. GA addition could specifically promote the proliferation of DON-induced IPEC-J2 cells in a dose- and time-dependent manner. In addition, GA addition significantly increased Bcl-2 gene expression ( P < 0.05 ) and superoxide dismutase and catalase activities ( P < 0.01 ) and decreased lactate dehydrogenase release, the contents of malonaldehyde, IL-8, and NF-κB ( P < 0.05 ), the relative mRNA abundances of IL-6, IL-8, TNF-α, COX-2, NF-κB, Bax, and caspase 3 ( P < 0.01 ), and the protein expressions of Bax and TNF-α. Moreover, a total of 1576, 289, 1398, and 154 differentially expressed genes were identified in CON vs. DON, CON vs. GA, CON vs. GAD, and DON vs. GAD, respectively. Transcriptome analysis revealed that MAPK, TNF, and NF-κB signaling pathways and some chemokines played significant roles in the regulation of inflammation and apoptosis induced by DON. GA may alleviate DON cytotoxicity via the TNF signaling pathway by downregulating IL-15, CCL5, and other gene expressions. These results indicated that GA could alleviate DON-induced oxidative stress, inflammation, and apoptosis via the TNF signaling pathway in IPEC-J2 cells.

scholarly journals Anticolitic Effect of Berberine in Rat Experimental Model: Impact of PGE2/p38 MAPK Pathways

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Li Jia ◽  
Kuijin Xue ◽  
Junheng Liu ◽  
Ola A. Habotta ◽  
Lianhai Hu ◽  
...  
Keyword(s):  
Mrna Expression ◽  
P38 Mapk ◽  
Experimental Colitis ◽  
Mucosal Damage ◽  
Isoquinoline Alkaloid ◽  
Protective Mechanism ◽  
Colon Mucosa ◽  
Tnf Α ◽  
Anti Inflammatory ◽  
High Doses

Berberine (BER), a natural isoquinoline alkaloid, has been demonstrated to have appreciable anticolitis effects. Nevertheless, the protective mechanism of BER in ulcerative colitis (UC) is barely understood. The present study was aimed at exploring the therapeutic efficacy of BER on UC in experimental colitis rat model. Rats were orally administered with BER for seven days at low and high doses (25 and 50 mg/kg/day) before AcOH intracolonic instillation. BER significantly retrieved colon inflammation and mucosal damage indicated by inhibition of macroscopic score and lessened the levels of inflammatory biomarkers (IL-1β, IL-6, TNF-α, MPO, and PGE2). Notable downregulation of mRNA expression of p38 MAPK and increased protein expression of TGF-β were achieved by BER treatment. The anti-inflammatory potential of BER was supported by the histopathological screening of colon mucosa. In addition, BER restored colonic antioxidant capacity through elevation of GSH level and antioxidant enzymatic activities (SOD, CAT, GPx, and GR) together with reductions of both MDA and NO levels. Marked downregulation of Nos2 mRNA expression is accompanied by increased Nrf2 and Hmox-1 expressions in colon specimens treated by BER. Furthermore, BER exhibited noticeable antiapoptotic activities through decreasing proapoptotic proteins (Bax and caspase-3) and lessening antiapoptotic Bcl-2 protein in the colon mucosa. Based on these findings, BER may improve colitis markedly which may be mediated by its striking antioxidant, anti-inflammatory, and antiapoptotic properties.

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