scholarly journals Mitophagy Eliminates the Accumulation of SARM1 on the Mitochondria, Alleviating Axon Degeneration in Acrylamide Neuropathy

2021 ◽  
Author(s):  
Shuai Wang ◽  
Hui Yong ◽  
Cuiqin Zhang ◽  
Kang Kang ◽  
Mingxue Song ◽  
...  
Keyword(s):  
Latent Period ◽  
Molecular Mechanisms ◽  
Mitochondrial Dynamics ◽  
Interleukin 1 ◽  
Biological Significance ◽  
Axon Degeneration ◽  
Dependent Manner ◽  
Mitochondrial Localization ◽  
Irreversible Damage ◽  
Axon Damage

Abstract Background: Sterile-α and toll/interleukin 1 receptor motif containing protein 1 (SARM1) is the central executioner of axon degeneration. Although it has been confirmed to have a mitochondrial targeting sequence and can bind to and stabilize PINK1 on depolarized mitochondria, the biological significance for mitochondrial localization of SARM1 is still unclear. Chronic acrylamide (ACR) intoxication can cause typical pathology of axonal injury, owning the potential to explore the interaction between mitochondria and SARM1 during the latent period of axon destruction.Methods: The expression and the mitochondria distribution of SARM1 were evaluated in in vivo and in vitro ACR neuropathy models. Transmission electron microscopy, immunoblotting, and immunofluorescence were performed to evaluate mitochondrial dynamics and PINK1-dependent mitophagy. LC3 turnover experiment and live cell imaging were conducted to further assess the state of mitophagy flux. In order to verify the effect of mitophagy in SARM1-mediated axon degeneration, low-dose and low-frequency rapamycin was administered in ACR-exposed rats to increase basal autophagy.Results: In a time- and dose-dependent manner, ACR induced peripheral nerve injury in rats and truncated axons of differentiated N2a cell. Moreover, the severity of this axon damage was consistent with the up-regulation of SARM1. SARM1 prominently accumulated on mitochondria, and at the same time mitophagy was activated. Importantly, rapamycin (RAPA) administration eliminated mitochondrial accumulated SARM1 and alleviated SARM1 dependent axonal degeneration.Conclusions: Complementing to the coordinated activity of NMNAT2 and SARM1, mitochondrial localization of SARM1 may be part of the self-limiting molecular mechanisms of Wallerian axon destruction. In the early latent period of axon damage, the mitochondrial localization of SARM1 will help it to be isolated by the mitochondrial network and to be degraded through PINK1-dependent mitophagy to maintain local axon homeostasis. When the mitochondrial quality control mechanisms are broken down, SARM1 will cause irreversible damage for axon degeneration. Moderate autophagy activation can be invoked as potential strategies to alleviate axon degeneration in ACR neuropathy and even other axon degeneration diseases.

scholarly journals Mitophagy Eliminates the Accumulation of SARM1 on the Mitochondria, Alleviating Programmed Axon Death in Acrylamide Neuropathy

2022 ◽  
Author(s):  
Shuai Wang ◽  
Hui Yong ◽  
Cuiqin Zhang ◽  
Kang Kang ◽  
Mingxue Song ◽  
...  
Keyword(s):  
Quality Control ◽  
Molecular Mechanisms ◽  
Interleukin 1 ◽  
Biological Significance ◽  
Control Mechanisms ◽  
Dependent Manner ◽  
Mitochondrial Network ◽  
Mitochondrial Localization ◽  
Mitochondrial Quality Control ◽  
Axon Loss

Abstract Sterile-α and toll/interleukin 1 receptor motif containing protein 1 (SARM1) is the central executioner of programmed axon death (Wallerian degeneration). Although it has been confirmed to have a mitochondrial targeting sequence and can bind to and stabilize PINK1 on mitochondria, the biological significance for mitochondrial localization of SARM1 is still unclear. The relationship between mitochondrial quality control mechanisms and programmed axon death also needs to be clarified. Chronic acrylamide (ACR) intoxication cause typical pathology of axon degeneration involving early axon loss. Here, we demonstrated that the SARM1 dependent Wallerian axon self-destruction pathway was activated following ACR intoxication. Moreover, increased SARM1 was observed on the mitochondria, which interfered with the mitochondrial quality control mechanisms. As a protective response to stress, mitochondrial components enriched in SARM1 were isolated from the mitochondrial network through an increased fission process and were degraded in an autophagy-dependent manner. Importantly, rapamycin (RAPA) administration eliminated mitochondrial accumulated SARM1 and inhibited axon loss. Thus, mitochondrial localization of SARM1 may be complement to the coordinated activity of NMNAT2 and SARM1, and may be part of the self-limiting molecular mechanisms of programmed axon death. In the early latent period, the mitochondrial localization of SARM1 will help it to be isolated by the mitochondrial network and to be degraded through mitophagy to maintain local axon homeostasis. When the mitochondrial quality control mechanisms are broken down, SARM1 will cause irreversible damage for axon death.

scholarly journals Molecular Machinery and Pathophysiology of Mitochondrial Dynamics

2021 ◽  
Vol 9 ◽  
Author(s):  
Yi-Han Chiu ◽  
Shu-Chuan Amy Lin ◽  
Chen-Hsin Kuo ◽  
Chia-Jung Li
Keyword(s):  
Molecular Mechanisms ◽  
Mitochondrial Dynamics ◽  
Biological Significance ◽  
Lipid Synthesis ◽  
Mitochondrial Morphology ◽  
Animal Cells ◽  
Main Site ◽  
Mechanical Proteins ◽  
Molecular Machinery ◽  
Active Processes

Mitochondria are double-membraned organelles that exhibit fluidity. They are the main site of cellular aerobic respiration, providing energy for cell proliferation, migration, and survival; hence, they are called “powerhouses.” Mitochondria play an important role in biological processes such as cell death, cell senescence, autophagy, lipid synthesis, calcium homeostasis, and iron balance. Fission and fusion are active processes that require many specialized proteins, including mechanical enzymes that physically alter mitochondrial membranes, and interface proteins that regulate the interaction of these mechanical proteins with organelles. This review discusses the molecular mechanisms of mitochondrial fusion, fission, and physiopathology, emphasizing the biological significance of mitochondrial morphology and dynamics. In particular, the regulatory mechanisms of mitochondria-related genes and proteins in animal cells are discussed, as well as research trends in mitochondrial dynamics, providing a theoretical reference for future mitochondrial research.

scholarly journals NFκB-dependent Down-regulation of Tumor Necrosis Factor Receptor-associated Proteins Contributes to Interleukin-1-mediated Enhancement of Ultraviolet B-induced Apoptosis

2005 ◽  
Vol 280 (16) ◽  
pp. 15635-15643 ◽  
Author(s):  
Birgit Pöppelmann ◽  
Kerstin Klimmek ◽  
Elwira Strozyk ◽  
Reinhard Voss ◽  
Thomas Schwarz ◽  
...  
Keyword(s):  
Tumor Necrosis ◽  
Molecular Mechanisms ◽  
Interleukin 1 ◽  
Tumor Necrosis Factor Receptor ◽  
Ultraviolet B ◽  
Dependent Manner ◽  
Tnf Receptor ◽  
Inhibitory Protein ◽  
Down Regulation ◽  
Induced Apoptosis

Activation of the transcription factor nuclear factor-κB (NFκB) by inflammatory cytokines like tumor necrosis (TNF) factor and interleukin-1 (IL-1) is generally associated with the induction of antiapoptotic pathways. Therefore, NFκB inhibits both intrinsically and extrinsically induced apoptosis and thus is regarded to act universally in an antiapoptotic fashion. Accordingly, activation of NFκB by IL-1 was shown to result in reduction of death ligand-induced apoptosis via up-regulation of antiapoptotic inhibitor of apoptosis proteins (IAPs). In contrast, apoptosis induced by ultraviolet-B radiation (UVB) was shown to be enhanced in an NFκB-dependent manner, indicating that NFκB can also act in a proapoptotic fashion. This study investigates the molecular mechanisms underlying IL-1-mediated enhancement of UVB-induced apoptosis. We show that NFκB activation in costimulation with UVB treatment results in repression of antiapoptotic genes and consequently in down-regulation of the respective proteins, like c-IAP, FLICE-inhibitory protein (FLIP), and some members of the TNF receptor-associated (TRAF)2 protein family. In parallel, TNFα is released, leading to activation of signaling pathways mediated by TNF receptor-1 (TNF-R1). Although TNF is well known to induce both proapoptotic and antiapoptotic effects, the down-regulated levels of TRAF-1, -2, and -6 proteins by IL-1 plus UVB action leads to a shift toward promotion of the proapoptotic pathway. In concert with the down-regulation of IAPs and FLIP, TNF-R1 activation as an additional proapoptotic stimulus now results in significant enhancement of UVB-induced apoptosis. Taken together, elucidation of the molecular mechanisms underlying IL-1-mediated enhancement of UVB-induced apoptosis revealed that NFκB does not exclusively act in an antiapoptotic fashion but may also mediate proapoptotic effects.

scholarly journals Mitochondrial Aurora kinase A induces mitophagy by interacting with MAP1LC3 and Prohibitin 2

2020 ◽  
Author(s):  
Giulia Bertolin ◽  
Marie-Clotilde Alves-Guerra ◽  
Agnès Burel ◽  
Claude Prigent ◽  
Roland Le Borgne ◽  
...  
Keyword(s):  
Mitochondrial Membrane ◽  
Molecular Mechanisms ◽  
Mitochondrial Dynamics ◽  
Aurora Kinase ◽  
Dependent Manner ◽  
Inner Mitochondrial Membrane ◽  
Serine Threonine Kinase ◽  
Independent Manner ◽  
Atp Production ◽  
Core Components

AbstractEpithelial and haematologic tumours often show the overexpression of the serine/threonine kinase AURKA. Recently, AURKA was shown to localise at mitochondria, where it regulates mitochondrial dynamics and ATP production. Here we define the molecular mechanisms of AURKA in regulating mitochondrial turnover by mitophagy. When overexpressed, AURKA induces the rupture of the Outer Mitochondrial Membrane in a proteasome-dependent manner. Then, AURKA triggers the degradation of Inner Mitochondrial Membrane (IMM)/matrix proteins by interacting with core components of the autophagy pathway. On the IMM, the kinase forms a tripartite complex with MAP1LC3 and the mitophagy receptor PHB2. This complex is necessary to trigger mitophagy in a PARK2/Parkin-independent manner. The formation of the tripartite complex is induced by the phosphorylation of PHB2 on Ser39, which is required for MAP1LC3 to interact with PHB2. Last, treatment with the PHB2 ligand Xanthohumol blocks AURKA-induced mitophagy by destabilising the tripartite complex. This treatment also restores normal ATP production levels. Altogether, these data provide evidence for a previously undetected role of AURKA in promoting mitophagy through the interaction with PHB2 and MAP1LC3. This work paves the way to the use of function-specific pharmacological inhibitors to counteract the effects of the overexpression of AURKA in cancer.

The Anti-Atherogenic Properties of Sesamin are Mediated via Improved Macrophage Cholesterol Efflux Through PPARγ1-LXRα and MAPK Signaling

2014 ◽  
Vol 84 (1-2) ◽  
pp. 79-91 ◽  
Author(s):  
Amin F. Majdalawieh ◽  
Hyo-Sung Ro
Keyword(s):  
Cholesterol Efflux ◽  
Transcriptional Activity ◽  
Molecular Mechanisms ◽  
Foam Cell ◽  
Mapk Signaling ◽  
Luciferase Reporter ◽  
Foam Cell Formation ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Macrophage Cholesterol Efflux

Background: Foam cell formation resulting from disrupted macrophage cholesterol efflux, which is triggered by PPARγ1 and LXRα, is a hallmark of atherosclerosis. Sesamin and sesame oil exert anti-atherogenic effects in vivo. However, the exact molecular mechanisms underlying such effects are not fully understood. Aim: This study examines the potential effects of sesamin (0, 25, 50, 75, 100 μM) on PPARγ1 and LXRα expression and transcriptional activity as well as macrophage cholesterol efflux. Methods: PPARγ1 and LXRα expression and transcriptional activity are assessed by luciferase reporter assays. Macrophage cholesterol efflux is evaluated by ApoAI-specific cholesterol efflux assays. Results: The 50 μM, 75 μM, and 100 μM concentrations of sesamin up-regulated the expression of PPARγ1 (p< 0.001, p < 0.001, p < 0.001, respectively) and LXRα (p = 0.002, p < 0.001, p < 0.001, respectively) in a concentration-dependent manner. Moreover, 75 μM and 100 μM concentrations of sesamin led to 5.2-fold (p < 0.001) and 6.0-fold (p<0.001) increases in PPAR transcriptional activity and 3.9-fold (p< 0.001) and 4.2-fold (p < 0.001) increases in LXR transcriptional activity, respectively, in a concentration- and time-dependent manner via MAPK signaling. Consistently, 50 μM, 75 μM, and 100 μM concentrations of sesamin improved macrophage cholesterol efflux by 2.7-fold (p < 0.001), 4.2-fold (p < 0.001), and 4.2-fold (p < 0.001), respectively, via MAPK signaling. Conclusion: Our findings shed light on the molecular mechanism(s) underlying sesamin’s anti-atherogenic effects, which seem to be due, at least in part, to its ability to up-regulate PPARγ1 and LXRα expression and transcriptional activity, improving macrophage cholesterol efflux. We anticipate that sesamin may be used as a therapeutic agent for treating atherosclerosis.

Antioxidant and Anti-inflammatory Activities of Organic and Aqueous Extracts of Northeast Algerian Marrubium vulgare

2018 ◽  
Vol 16 (S1) ◽  
pp. S119-S129
Author(s):  
I. Namoune ◽  
B. Khettal ◽  
A.M. Assaf ◽  
S. Elhayek ◽  
L. Arrar
Keyword(s):  
Ethyl Acetate ◽  
Methanolic Extract ◽  
Ethyl Acetate Extract ◽  
Interleukin 1 ◽  
Total Phenolic ◽  
Dependent Manner ◽  
Aqueous Extracts ◽  
Traditional Use ◽  
Marrubium Vulgare ◽  
Anti Inflammatory

Marrubium vulgare (Lamiaceae) is frequently used in traditional medicine to treat many illnesses from ancient times. Its beneficial effects include antibacterial, antioedematogenic, and analgesic activities. This study was designed to evaluate the antioxidant and anti-inflammatory activities of organic and aqueous extracts of the leaves, the flowers, the stems, and the roots of Marrubium vulgare. The total phenolic and flavonoid contents as well as the antioxidant and the anti-inflammatory effects of methanol, chloroform, ethyl acetate, and aqueous extracts have been investigated by using different in-vitro methods. It was found that the ethyl acetate extract from Marrubium vulgare stems had the highest total phenolic content, while the ethyl acetate extract from the leaves yielded a high concentration of flavonoids. The ethyl acetate extract from the stems exhibited the highest activity in scavenging of 2,2-diphenyl- 1-picrylhydrazyl (DPPH), as well as in protecting erythrocytes. The leaves aqueous extract exhibited the highest ferrous chelating activity and its methanolic extract was found to be the strongest inhibitor of lipid peroxidation in β-carotene bleaching assay. The leaves chloroform extracts as well as the flowers methanol, chloroform, and ethyl acetate extracts were found to decrease the pro-inflammatory tumor necrosis factor alpha (TNF-α) cytokine levels in a dose-dependent manner. On the other hand, the flowers methanolic extract and the leaves methanol, ethyl acetate, and aqueous extracts decreased the interleukin-1 beta (IL- 1β) release. It was also found that the methanol extract from the flowers and the chloroform extract from the stems of Marrubium vulgare inhibited interleukin-8 (IL-8) release. This study provides a scientific basis for the traditional use of Marrubium vulgare as an anti-inflammatory agent and for the plant to be considered as an important resource of natural antioxidants.

Neuroblastoma: An Updated Review on Biology and Treatment

2020 ◽  
Vol 20 (13) ◽  
pp. 1014-1022 ◽  
Author(s):  
Suresh Mallepalli ◽  
Manoj Kumar Gupta ◽  
Ramakrishna Vadde
Keyword(s):  
Survival Rate ◽  
High Risk ◽  
Molecular Mechanisms ◽  
Definitive Treatment ◽  
Therapeutic Drug ◽  
Mycn Amplification ◽  
Dependent Manner ◽  
High Risk Patients ◽  
Treatment And Prevention ◽  
Risk Patients

Background: Neuroblastoma (NB) is the second leading extracranial solid tumors of early childhood and clinically characterized by the presence of round, small, monomorphic cells with excess nuclear pigmentation (hyperchromasia).Owing to a lack of definitive treatment against NB and less survival rate in high-risk patients, there is an urgent requirement to understand molecular mechanisms associated with NB in a better way, which in turn can be utilized for developing drugs towards the treatment of NB in human. Objectives: In this review, an approach was adopted to understand major risk factors, pathophysiology, the molecular mechanism associated with NB, and various therapeutic agents that can serve as drugs towards the treatment of NB in humans. Conclusions: Numerous genetic (e.g., MYCN amplification), perinatal, and gestational factors are responsible for developing NB. However, no definite environmental or parental exposures responsible for causing NB have been confirmed to date. Though intensive multimodal treatment approaches, namely, chemotherapy, surgery &radiation, may help in improving the survival rate in children, these approaches have several side effects and do not work efficiently in high-risk patients. However, recent studies suggested that numerous phytochemicals, namely, vincristine, and matrine have a minimal side effect in the human body and may serve as a therapeutic drug during the treatment of NB. Most of these phytochemicals work in a dose-dependent manner and hence must be prescribed very cautiously. The information discussed in the present review will be useful in the drug discovery process as well as treatment and prevention on NB in humans.

Pisosterol Induces G2/M Cell Cycle Arrest and Apoptosis via the ATM/ATR Signaling Pathway in Human Glioma Cells

2020 ◽  
Vol 20 (6) ◽  
pp. 734-750
Author(s):  
Wallax A.S. Ferreira ◽  
Rommel R. Burbano ◽  
Claudia do Ó. Pessoa ◽  
Maria L. Harada ◽  
Bárbara do Nascimento Borges ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Signaling Pathway ◽  
Glioma Cell ◽  
Molecular Mechanisms ◽  
Glioma Cells ◽  
Dependent Manner ◽  
M Cell ◽  
Trypan Blue Exclusion ◽  
Cycle Arrest

Background: Pisosterol, a triterpene derived from Pisolithus tinctorius, exhibits potential antitumor activity in various malignancies. However, the molecular mechanisms that mediate the pisosterol-specific effects on glioma cells remain unknown. Objective: This study aimed to evaluate the antitumoral effects of pisosterol on glioma cell lines. Methods: The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and trypan blue exclusion assays were used to evaluate the effect of pisosterol on cell proliferation and viability in glioma cells. The effect of pisosterol on the distribution of the cells in the cell cycle was performed by flow cytometry. The expression and methylation pattern of the promoter region of MYC, ATM, BCL2, BMI1, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, MDM2, p14ARF and TP53 was analyzed by RT-qPCR, western blotting and bisulfite sequencing PCR (BSP-PCR). Results: Here, it has been reported that pisosterol markedly induced G2/M arrest and apoptosis and decreased the cell viability and proliferation potential of glioma cells in a dose-dependent manner by increasing the expression of ATM, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, p14ARF and TP53 and decreasing the expression of MYC, BCL2, BMI1 and MDM2. Pisosterol also triggered both caspase-independent and caspase-dependent apoptotic pathways by regulating the expression of Bcl-2 and activating caspase-3 and p53. Conclusions: It has been, for the first time, confirmed that the ATM/ATR signaling pathway is a critical mechanism for G2/M arrest in pisosterol-induced glioma cell cycle arrest and suggests that this compound might be a promising anticancer candidate for further investigation.

VDAC1 Mediated Anticancer Activity of Gallic Acid in Human Lung Adenocarcinoma A549 Cells

2018 ◽  
Vol 18 (2) ◽  
pp. 255-262 ◽  
Author(s):  
Aikebaier Maimaiti ◽  
Amier Aili ◽  
Hureshitanmu Kuerban ◽  
Xuejun Li
Keyword(s):  
Western Blot ◽  
Cell Viability ◽  
Gallic Acid ◽  
Molecular Mechanisms ◽  
A549 Cells ◽  
Dependent Manner ◽  
Lung Carcinoma Cells ◽  
Induced Apoptosis ◽  
The Impact

Aims: Gallic acid (GA) is generally distributed in a variety of plants and foods, and possesses cell growth-inhibiting activities in cancer cell lines. In the present study, the impact of GA on cell viability, apoptosis induction and possible molecular mechanisms in cultured A549 lung carcinoma cells was investigated. Methods: In vitro experiments showed that treating A549 cells with various concentrations of GA inhibited cell viability and induced apoptosis in a dose-dependent manner. In order to understand the mechanism by which GA inhibits cell viability, comparative proteomic analysis was applied. The changed proteins were identified by Western blot and siRNA methods. Results: Two-dimensional electrophoresis revealed changes that occurred to the cells when treated with or without GA. Four up-regulated protein spots were clearly identified as malate dehydrogenase (MDH), voltagedependent, anion-selective channel protein 1(VDAC1), calreticulin (CRT) and brain acid soluble protein 1(BASP1). VDAC1 in A549 cells was reconfirmed by western blot. Transfection with VDAC1 siRNA significantly increased cell viability after the treatment of GA. Further investigation showed that GA down regulated PI3K/Akt signaling pathways. These data strongly suggest that up-regulation of VDAC1 by GA may play an important role in GA-induced, inhibitory effects on A549 cell viability.

Molecular Mechanisms of Curcumin in Neuroinflammatory Disorders: A Mini Review of Current Evidences

2019 ◽  
Vol 19 (3) ◽  
pp. 247-258 ◽  
Author(s):  
Mahsa Hatami ◽  
Mina Abdolahi ◽  
Neda Soveyd ◽  
Mahmoud Djalali ◽  
Mansoureh Togha ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
English Language ◽  
Molecular Mechanisms ◽  
Randomized Clinical Trials ◽  
Mitochondrial Dynamics ◽  
Nuclear Factor Κb ◽  
General Term ◽  
Neuroinflammatory Disease ◽  
Tnf Α ◽  
Factor Α

Objective: Neuroinflammatory disease is a general term used to denote the progressive loss of neuronal function or structure. Many neuroinflammatory diseases, including Alzheimer’s, Parkinson’s, and multiple sclerosis (MS), occur due to neuroinflammation. Neuroinflammation increases nuclear factor-κB (NF-κB) levels, cyclooxygenase-2 enzymes and inducible nitric oxide synthase, resulting in the release of inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). It could also lead to cellular deterioration and symptoms of neuroinflammatory diseases. Recent studies have suggested that curcumin (the active ingredient in turmeric) could alleviate the process of neuroinflammatory disease. Thus, the present mini-review was conducted to summarize studies regarding cellular and molecular targets of curcumin relevant to neuroinflammatory disorders. Methods: A literature search strategy was conducted for all English-language literature. Studies that assessed the various properties of curcuminoids in respect of neuroinflammatory disorders were included in this review. Results: The studies have suggested that curcuminoids have significant anti- neuroinflammatory, antioxidant and neuroprotective properties that could attenuate the development and symptom of neuroinflammatory disorders. Curcumin can alleviate neurodegeneration and neuroinflammation through multiple mechanisms, by reducing inflammatory mediators (such as TNF-α, IL-1β, nitric oxide and NF-κB gene expression), and affect mitochondrial dynamics and even epigenetic changes. Conclusion: It is a promising subject of study in the prevention and management of the neuroinflammatory disease. However, controlled, randomized clinical trials are needed to fully evaluate its clinical potential.

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