scholarly journals Liraglutide Treatment Ameliorates Neurotoxicity Induced by Stable Silencing of Pin1

2019 ◽  
Vol 20 (20) ◽  
pp. 5064 ◽  
Author(s):  
Marzia Bianchi ◽  
Valentina D’Oria ◽  
Maria Rita Braghini ◽  
Stefania Petrini ◽  
Melania Manco
Keyword(s):  
Glucose Metabolism ◽  
Cell Viability ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Fission ◽  
Protein Glycation ◽  
Oxygen Species ◽  
Impaired Glucose Metabolism ◽  
Altered Glucose ◽  
Peptidylprolyl Isomerase ◽  
In Cells

Post-translational modulation of peptidylprolyl isomerase Pin1 might link impaired glucose metabolism and neurodegeneration, being Pin1 effectors target for the glucagon-Like-Peptide1 analog liraglutide. We tested the hypotheses in Pin1 silenced cells (SH-SY5Y) treated with 2-deoxy-d-glucose (2DG) and methylglyoxal (MG), stressors causing altered glucose trafficking, glucotoxicity and protein glycation. Rescue by liraglutide was investigated. Pin1 silencing caused increased levels of reactive oxygen species, upregulated energy metabolism as suggested by raised levels of total ATP content and mRNA of SIRT1, PGC1α, NRF1; enhanced mitochondrial fission events as supported by raised protein expression of FIS1 and DRP1. 2DG and MG reduced significantly cell viability in all the cell lines. In Pin1 KD clones, 2DG exacerbated altered mitochondrial dynamics causing higher rate of fission events. Liraglutide influenced insulin signaling pathway (GSK3b/Akt); improved cell viability also in cells treated with 2DG; but it did not revert mitochondrial dysfunction in Pin1 KD model. In cells treated with MG, liraglutide enhanced cell viability, reduced ROS levels and cell death (AnnexinV/PI); and trended to reduce anti-apoptotic signals (BAX, BCL2, CASP3). Pin1 silencing mimics neuronal metabolic impairment of patients with impaired glucose metabolism and neurodegeneration. Liraglutide rescues to some extent cellular dysfunctions induced by Pin1 silencing.

Abstract P049: Circadian Clock Dysfunction Impairs Mitochondrial Fitness And Contributes To Myocardial Ischemic Injury

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Inna Rabinovich-Nikitin ◽  
Illana Posen ◽  
Victoria Margulets ◽  
Tami A Martino ◽  
Lorrie A Kirshenbaum
Keyword(s):  
Quality Control ◽  
Cell Viability ◽  
Circadian Clock ◽  
Cardiac Myocytes ◽  
Mitochondrial Dynamics ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Control Mechanisms ◽  
Complex Activity ◽  
Mitochondrial Dynamic

Cardiac function is highly reliant on mitochondrial oxidative metabolism and fitness. The circadian clock is critically linked to vital physiological process including mitochondrial fission, fusion and quality control mechanisms. However, little is known of how the circadian clock regulates these vital processes in the heart. Herein, we identified a putative circadian Clock - mitochondrial interactome that gates an adaptive stress response for cell viability during myocardial ischemia reperfusion (I-R) injury. We show that Clock transcriptionally coordinates expression of mitochondrial dynamic fusion and fission, bioenergetic and quality control proteins in cardiac myocytes. Transcriptome and gene ontology mapping revealed Clock defective hearts subjected to I-R exhibited major transcriptional deficits in several key survival processes including mitochondrial dynamics, bioenergetics and autophagy that were reduced further following I-R. Gain of function of Clock activity re-established gene transcription of mitochondrial respiratory complex activity, quality control mechanisms and cell viability. Collectively, our data show that mitochondrial fitness and cell survival is mutually dependent upon and obligatorily linked to transcription of the circadian Clock gene in cardiac myocytes. Our data suggest the functional loss of Clock activity predisposes cardiac myocytes to metabolic catastrophe. Hence, therapeutic strategies designed to preserve circadian clock activity in the hearts may prove beneficial in reducing morbidity and mortality following ischemia -related pathologies such as myocardial infarction.

scholarly journals Mitochondrial dynamics and reactive oxygen species initiate thrombopoiesis from mature megakaryocytes

2021 ◽  
Vol 5 (6) ◽  
pp. 1706-1718
Author(s):  
Sonia Poirault-Chassac ◽  
Valérie Nivet-Antoine ◽  
Amandine Houvert ◽  
Alexandre Kauskot ◽  
Evelyne Lauret ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Bone Marrow ◽  
Early Stage ◽  
Mitochondrial Dynamics ◽  
Blood Platelets ◽  
Mitochondrial Fission ◽  
Reactive Oxygen ◽  
Functional Coupling ◽  
Oxygen Species ◽  
Nox Inhibitors

Abstract Blood platelets are essential for controlling hemostasis. They are released by megakaryocytes (MKs) located in the bone marrow, upon extension of cytoplasmic protrusions into the lumen of bone marrow sinusoids. Their number increases in postpulmonary capillaries, suggesting a role for oxygen gradient in thrombopoiesis (ie, platelet biogenesis). In this study, we show that initiation of thrombopoiesis from human mature MKs was enhanced under hyperoxia or during pro-oxidant treatments, whereas antioxidants dampened it. Quenching mitochondrial reactive oxygen species (mtROS) with MitoTEMPO decreased thrombopoiesis, whereas genetically enhancing mtROS by deacetylation-null sirtuin-3 expression increased it. Blocking cytosolic ROS production by NOX inhibitors had no impact. Classification according to the cell roundness index delineated 3 stages of thrombopoiesis in mature MKs. Early-stage round MKs exhibited the highest index, which correlated with low mtROS levels, a mitochondrial tubular network, and the mitochondrial recruitment of the fission activator Drp1. Intermediate MKs at the onset of thrombopoiesis showed high mtROS levels and small, well-delineated mitochondria. Terminal MKs showed the lowest roundness index and long proplatelet extensions. Inhibiting Drp1-dependent mitochondrial fission of mature MKs by Mdivi-1 favored a tubular mitochondrial network and lowered both mtROS levels and intermediate MKs proportion, whereas enhancing Drp1 activity genetically had opposite effects. Reciprocally, quenching mtROS limited mitochondrial fission in round MKs. These data demonstrate a functional coupling between ROS and mitochondrial fission in MKs, which is crucial for the onset of thrombopoiesis. They provide new molecular cues that control initiation of platelet biogenesis and may help elucidate some unexplained thrombocytopenia.

MiR-485-5p Promotes Neuron Survival through Mediating Rac1/Notch2 Signaling Pathway after Cerebral Ischemia/Reperfusion

2020 ◽  
Vol 17 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Xuan Chen ◽  
Sumei Zhang ◽  
Peipei Shi ◽  
Yangli Su ◽  
Dong Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Viability ◽  
Therapeutic Option ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Small Gtpase ◽  
Luciferase Reporter ◽  
Pathological Feature ◽  
In Cells

Objective: Ischemia-reperfusion (I/R) injury is a pathological feature of ischemic stroke. This study investigated the regulatory role of miR-485-5p in I/R injury. Methods: SH-SY5Y cells were induced with oxygen and glucose deprivation/reoxygenation (OGD/R) to mimic I/R injury in vitro. Cells were transfected with designated constructs (miR-485- 5p mimics, miR-485-5p inhibitor, lentiviral vectors overexpressing Rac1 or their corresponding controls). Cell viability was evaluated using the MTT assay. The concentrations of lactate dehydrogenase, malondialdehyde, and reactive oxygen species were detected to indicate the degree of oxidative stress. Flow cytometry and caspase-3 activity assay were used for apoptosis assessment. Dual-luciferase reporter assay was performed to confirm that Rac family small GTPase 1 (Rac1) was a downstream gene of miR-485-5p. Results: OGD/R resulted in decreased cell viability, elevated oxidative stress, increased apoptosis, and downregulated miR-485-5p expression in SH-SY5Y cells. MiR-485-5p upregulation alleviated I/R injury, evidenced by improved cell viability, decreased oxidative markers, and reduced apoptotic rate. OGD/R increased the levels of Rac1 and neurogenic locus notch homolog protein 2 (Notch2) signaling-related proteins in cells with normal miR-485-5p expression, whereas miR- 485-5p overexpression successfully suppressed OGD/R-induced upregulation of these proteins. Furthermore, the delivery of vectors overexpressing Rac1 in miR-485-5p mimics-transfected cells reversed the protective effect of miR-485-5p in cells with OGD/R-induced injury. Conclusion: This study showed that miR-485-5p protected cells following I/R injury via targeting Rac1/Notch2 signaling suggest that targeted upregulation of miR-485-5p might be a promising therapeutic option for the protection against I/R injury.

scholarly journals Adipose Tissue Immunomodulation and Treg/Th17 Imbalance in the Impaired Glucose Metabolism of Children with Obesity

Children ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 554
Author(s):  
Stefania Croce ◽  
Maria Antonietta Avanzini ◽  
Corrado Regalbuto ◽  
Erika Cordaro ◽  
Federica Vinci ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Glucose Metabolism ◽  
Th17 Cells ◽  
Metabolic Disorders ◽  
Potential Role ◽  
Immune Monitoring ◽  
Metabolic Dysfunction ◽  
Impaired Glucose Metabolism ◽  
T Cell Infiltration

In the last few decades, obesity has increased dramatically in pediatric patients. Obesity is a chronic disease correlated with systemic inflammation, characterized by the presence of CD4 and CD8 T cell infiltration and modified immune response, which contributes to the development of obesity related diseases and metabolic disorders, including impaired glucose metabolism. In particular, Treg and Th17 cells are dynamically balanced under healthy conditions, but imbalance occurs in inflammatory and pathological states, such as obesity. Some studies demonstrated that peripheral Treg and Th17 cells exhibit increased imbalance with worsening of glucose metabolic dysfunction, already in children with obesity. In this review, we considered the role of adipose tissue immunomodulation and the potential role played by Treg/T17 imbalance on the impaired glucose metabolism in pediatric obesity. In the patient care, immune monitoring could play an important role to define preventive strategies of pediatric metabolic disease treatments.

scholarly journals CBIO-07. CELL DEATH INDUCED BY AN OSCILLATING MAGNETIC FIELD IN PATIENT DERIVED GLIOBLASTOMA CELLS IS MEDIATED BY REACTIVE OXYGEN SPECIES

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii17-ii17
Author(s):  
Shashank Hambarde ◽  
Martyn Sharpe ◽  
David Baskin ◽  
Santosh Helekar
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Cell Viability ◽  
Cortical Neurons ◽  
Reactive Oxygen ◽  
Great Promise ◽  
Antioxidant Vitamin ◽  
Ros Generation ◽  
Oxygen Species ◽  
Novel Therapy

Abstract Noninvasive cancer therapy with minimal side effects would be ideal for improving patient outcome in the clinic. We have developed a novel therapy using strong rotating magnets mounted on a helmet. They generate oscillating magnetic fields (OMF) that penetrate through the skull and cover the entire brain. We have demonstrated that OMF can effectively kill patient derived glioblastoma (GBM) cells in cell culture without having cytotoxic effects on cortical neurons and normal human astrocytes (NHA). Exposure of GBM cells to OMF reduced the cell viability by 33% in comparison to sham-treated cells (p< 0.001), while not affecting NHA cell viability. Time lapse video-microscopy for 16 h after OMF exposure showed a marked elevation of mitochondrial reactive oxygen species (ROS), and rapid apoptosis of GBM cells due to activation of caspase 3. Addition of a potent antioxidant vitamin E analog Trolox effectively blocked OMF-induced GBM cell death. Furthermore, OMF significantly potentiated the cytotoxic effect of the pro-oxidant Benzylamine. The results of our studies demonstrate that OMF-induced cell death is mediated by ROS generation. These results demonstrate a potent oncolytic effect on GBM cells that is novel and unrelated to any previously described therapy, including a very different mechanism of action and different technology compared to Optune therapy. The effect is very powerful, and unlike Optune, can be seen within hours after initiation of treatment. We believe that this technology holds great promise for new, effective and nontoxic treatment of glioblastoma.

scholarly journals Mitochondrial fission and mitophagy are independent mechanisms regulating ischemia/reperfusion injury in primary neurons

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Anthony R. Anzell ◽  
Garrett M. Fogo ◽  
Zoya Gurm ◽  
Sarita Raghunayakula ◽  
Joseph M. Wider ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Ischemia Reperfusion Injury ◽  
Mitochondrial Dynamics ◽  
Ischemia Reperfusion ◽  
Mitochondrial Fission ◽  
Conditional Knockout ◽  
Mitochondrial Morphology ◽  
Primary Neurons ◽  
Mitochondrial Fragmentation

AbstractMitochondrial dynamics and mitophagy are constitutive and complex systems that ensure a healthy mitochondrial network through the segregation and subsequent degradation of damaged mitochondria. Disruption of these systems can lead to mitochondrial dysfunction and has been established as a central mechanism of ischemia/reperfusion (I/R) injury. Emerging evidence suggests that mitochondrial dynamics and mitophagy are integrated systems; however, the role of this relationship in the context of I/R injury remains unclear. To investigate this concept, we utilized primary cortical neurons isolated from the novel dual-reporter mitochondrial quality control knockin mice (C57BL/6-Gt(ROSA)26Sortm1(CAG-mCherry/GFP)Ganl/J) with conditional knockout (KO) of Drp1 to investigate changes in mitochondrial dynamics and mitophagic flux during in vitro I/R injury. Mitochondrial dynamics was quantitatively measured in an unbiased manner using a machine learning mitochondrial morphology classification system, which consisted of four different classifications: network, unbranched, swollen, and punctate. Evaluation of mitochondrial morphology and mitophagic flux in primary neurons exposed to oxygen-glucose deprivation (OGD) and reoxygenation (OGD/R) revealed extensive mitochondrial fragmentation and swelling, together with a significant upregulation in mitophagic flux. Furthermore, the primary morphology of mitochondria undergoing mitophagy was classified as punctate. Colocalization using immunofluorescence as well as western blot analysis revealed that the PINK1/Parkin pathway of mitophagy was activated following OGD/R. Conditional KO of Drp1 prevented mitochondrial fragmentation and swelling following OGD/R but did not alter mitophagic flux. These data provide novel evidence that Drp1 plays a causal role in the progression of I/R injury, but mitophagy does not require Drp1-mediated mitochondrial fission.

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