scholarly journals The key role of microtubules in hypoxia preconditioning-induced nuclear translocation of HIF-1α in rat cardiomyocytes

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3662 ◽  
Author(s):  
Hai Guo ◽  
Hong Zheng ◽  
Jianjiang Wu ◽  
Hai-ping Ma ◽  
Jin Yu ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Hypoxic Preconditioning ◽  
Glycolytic Enzymes ◽  
Laser Scanning Microscopy ◽  
Rat Cardiomyocytes ◽  
Hypoxia Group ◽  
Stabilizer Group ◽  
Microtubule Stabilizer ◽  
Microtubule Structure

Background Hypoxia-inducible factor (HIF)-1 is involved in the regulation of hypoxic preconditioning in cardiomyocytes. Under hypoxic conditions, HIF-1α accumulates and is translocated to the nucleus, where it forms an active complex with HIF-1β and activates transcription of approximately 60 kinds of hypoxia-adaptive genes. Microtubules are hollow tubular structures in the cell that maintain cellular morphology and that transport substances. This study attempted to clarify the role of microtubule structure in the endonuclear aggregation of HIF-1α following hypoxic preconditioning of cardiomyocytes. Methods Primary rat cardiomyocytes were isolated and cultured. The cardiomyocyte culture system was used to establish a hypoxia model and a hypoxic preconditioning model. Interventions were performed on primary cardiomyocytes using a microtubule-depolymerizing agent and different concentrations of a microtubule stabilizer. The microtubule structure and the degree of HIF-1α nuclear aggregation were observed by confocal laser scanning microscopy. The expression of HIF-1α in the cytoplasm and nucleus was detected using Western blotting. Cardiomyocyte energy content, reflected by adenosine triphosphate/adenosine diphosphate (ATP/ADP), and key glycolytic enzymes were monitored by colorimetry and high-performance liquid chromatography (HPLC). Reactive oxygen species (ROS) production was also used to comprehensively assess whether microtubule stabilization can enhance the myocardial protective effect of hypoxic preconditioning. Results During prolonged hypoxia, it was found that the destruction of the microtubule network structure of cardiomyocytes was gradually aggravated. After this preconditioning, an abundance of HIF-1α was clustered in the nucleus. When the microtubules were depolymerized and hypoxia pretreatment was performed, HIF-1α clustering occurred around the nucleus, and HIF-1α nuclear expression was low. The levels of key glycolytic enzymes were significantly higher in the microtubule stabilizer group than in the hypoxia group. Additionally, the levels of lactate dehydrogenase and ROS were significantly lower in the microtubule stabilizer group than in the hypoxia group. Conclusion The microtubules of cardiomyocytes may be involved in the process of HIF-1α endonuclear aggregation, helping to enhance the anti-hypoxic ability of cardiomyocytes.

scholarly journals Potential role of nuclear translocation of glyceraldehyde-3-phosphate dehydrogenase in apoptosis and oxidative stress

2001 ◽  
Vol 114 (9) ◽  
pp. 1643-1653 ◽  
Author(s):  
Z. Dastoor ◽  
J.L. Dreyer
Keyword(s):  
Oxidative Stress ◽  
Laser Scanning ◽  
Fluorescent Protein ◽  
Nuclear Translocation ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Apoptotic Cells ◽  
Transfected Cells ◽  
And Oxidative Stress

Recent studies indicating a role of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in apoptosis or oxidative stress has been reported. Using confocal laser-scanning microscopy, we have investigated the cellular distribution of GAPDH in central nervous system (CNS)-derived cells (neuroblastoma mNB41A3), in non-CNS derived cells (R6 fibroblast) and in an apoptosis-resistant Bcl2 overexpressing cell line (R6-Bcl2). Induction of apoptosis by staurosporine or MG132 and oxidative stress by H(2)O(2) or FeCN enhanced the nuclear translocation of endogenous GAPDH in all cell types, as detected by immunocytochemistry. In apoptotic cells, GAPDH expression is three times higher than in non-apoptotic cells. Consistent with a role for GAPDH in apoptosis, overexpression of a GAPDH-green fluorescent protein (GAPDH-GFP) hybrid increased nuclear import of GAPDH-GFP into transfected cells and the number of apoptotic cells, and made them more sensitive to agents that induce apoptosis. Bcl2 overexpression prevents nuclear translocation of GAPDH and apoptosis in untransfected cells, but not in transfected cells that overexpress GAPDH-GFP. Our observations indicate that nuclear translocation of GAPDH may play a role in apoptosis and oxidative stress, probably related to the activity of GAPDH as a DNA repair enzyme or as a nuclear carrier for pro-apoptotic molecules.

Delayed cytoprotection induced by hypoxic preconditioning in cultured neonatal rat cardiomyocytes: Role of GRP78

Life Sciences ◽  
2007 ◽  
Vol 81 (13) ◽  
pp. 1042-1049 ◽  
Author(s):  
Yan-Xia Pan ◽  
An-Jing Ren ◽  
Juan Zheng ◽  
Wei-Fang Rong ◽  
Hong Chen ◽  
...  
Keyword(s):  
Hypoxic Preconditioning ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Neonatal Rat Cardiomyocytes

scholarly journals Activation of nuclear factor-κB during doxorubicin-induced apoptosis in endothelial cells and myocytes is pro-apoptotic: the role of hydrogen peroxide

2002 ◽  
Vol 367 (3) ◽  
pp. 729-740 ◽  
Author(s):  
Suwei WANG ◽  
Srigiridhar KOTAMRAJU ◽  
Eugene KONOREV ◽  
Shasi KALIVENDI ◽  
Joy JOSEPH ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Nuclear Translocation ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Apoptotic Pathway ◽  
Toxic Side Effect ◽  
Rat Cardiomyocytes ◽  
A Cell ◽  
Induced Apoptosis

Doxorubicin (DOX) is a widely used anti-tumour drug. Cardiotoxicity is a major toxic side effect of DOX therapy. Although recent studies implicated an apoptotic pathway in DOX-induced cardiotoxicity, the mechanism of DOX-induced apoptosis remains unclear. In the present study, we investigated the role of reactive oxygen species and the nuclear transcription factor nuclear factor κB (NF-κB) during apoptosis induced by DOX in bovine aortic endothelial cells (BAECs) and adult rat cardiomyocytes. DOX-induced NF-κB activation is both dose- and time-dependent, as demonstrated using electrophoretic mobility-shift assay and luciferase and p65 (Rel A) nuclear-translocation assays. Addition of a cell-permeant iron metalloporphyrin significantly suppressed NF-κB activation and apoptosis induced by DOX. Overexpression of glutathione peroxidase, which detoxifies cellular H2O2, significantly decreased DOX-induced NF-κB activation and apoptosis. Inhibition of DOX-induced NF-κB activation by a cell-permeant peptide SN50 that blocks translocation of the NF-κB complex into the nucleus greatly diminished DOX-induced apoptosis. Apoptosis was inhibited when IκB mutant vector, another NF-κB inhibitor, was added to DOX-treated BAECs. These results suggest that NF-κB activation in DOX-treated endothelial cells and myocytes is pro-apoptotic, in contrast with DOX-treated cancer cells, where NF-κB activation is anti-apoptotic. Removal of intracellular H2O2 protects endothelial cells and myocytes from DOX-induced apoptosis, possibly by inhibiting NF-κB activation. These findings suggest a novel mechanism for enhancing the therapeutic efficacy of DOX.

Abstract 862: Ser517:-phosphorylation Of Sirt1 Is Required For Its Pi3k/akt-mediated Nuclear Translocation And Cardiomyocyte Protection Against Oxidant Stress In Failing Hearts.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Masaya Tanno ◽  
Tetsuji Miura ◽  
Takayuki Miki ◽  
Toshiyuki Yano ◽  
Yoshiyuki Horio ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Oxidant Stress ◽  
C2c12 Cells ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Intracellular Location ◽  
Transfected Cells ◽  
Induced Apoptosis

[Purpose] We recently found that SIRT1, a protein deacetylase, shuttles between the nucleus and cytoplasm. In this study, we examined the role of nuclear SIRT1 in cardiomyocyte protection against oxidant stress and involvement of PI3K/Akt in the nuclear translocation. [Methods and Results] First, the critical intracellular location of SIRT1 for its anti-apoptotic function was examined. C2C12 cells were transfected with wild-type SIRT1 (WT) or SIRT1 with site-directed mutations in the nuclear localizing signal (mtNLS) and exposed to antimycin A (AA), an oxidative stressor. AA-induced apoptosis was suppressed in WT-transfected cells expressing SIRT1 in the nuclei compared with that in mtNLS-transfected cells expressing SIRT1 in the cytoplasm (TUNEL-positive cells = 4.4±0.7% vs. 34.6±8.0%). AA-induced apoptosis and also angiotensin II-(angII)-induced apoptosis in neonatal rat cardiomyocytes (NRCM) were suppressed by resveratrol, a SIRT1 activator. This protective effect of resveratrol was attenuated by transfection of SIRT1-siRNA but not by transfection of control siRNA. Next, we assessed the role of PI3K/Akt in nuclear translocation of SIRT1. SIRT1 in NRCM was localized in both the nucleus and cytoplasm under baseline conditions, and IGF-1 induced its nuclear translocation. This effect of IGF-1 was suppressed by LY294002 (LY), a PI3K inhibitor. Deletion mutagenesis study showed that LY-induced nuclear exclusion was observed for SIRT1[223–540] but not for SIRT1[223– 489]. Replacement of serine517 with alanine (S517A) increased cytoplasmic SIRT1, and S517A showed attenuated nuclear translocation in response to IGF-1, indicating that serine517 is the target site of PI3K/Akt. Finally, to confirm heart failure-associated SIRT1 translocation in vivo, myocardial infarction was induced in WKY rats. The number of ventricular cardiomyocytes with nuclear SIRT1 at 4 weeks after infarction was significantly larger than that in sham-operated hearts (10.2±2.9% vs. 0.7±0.2%). [Conclusion] The results suggest that phosphorylation of SIRT1 at Ser517 by PI3K/Akt is involved in nuclear translocation of SIRT1, which contributes to cardiomyocyte protection from oxidant stress-mediated injury in failing hearts.

scholarly journals EGFR-ERK induced activation of GRHL1 promotes cell cycle progression by up-regulating cell cycle related genes in lung cancer

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Yiming He ◽  
Mingxi Gan ◽  
Yanan Wang ◽  
Tong Huang ◽  
Jianbin Wang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Potential Role ◽  
Target Genes ◽  
Nuclear Translocation ◽  
Phosphorylation Site ◽  
Promoter Regions ◽  
Cycle Progression

AbstractGrainyhead-like 1 (GRHL1) is a transcription factor involved in embryonic development. However, little is known about the biological functions of GRHL1 in cancer. In this study, we found that GRHL1 was upregulated in non-small cell lung cancer (NSCLC) and correlated with poor survival of patients. GRHL1 overexpression promoted the proliferation of NSCLC cells and knocking down GRHL1 inhibited the proliferation. RNA sequencing showed that a series of cell cycle-related genes were altered when knocking down GRHL1. We further demonstrated that GRHL1 could regulate the expression of cell cycle-related genes by binding to the promoter regions and increasing the transcription of the target genes. Besides, we also found that EGF stimulation could activate GRHL1 and promoted its nuclear translocation. We identified the key phosphorylation site at Ser76 on GRHL1 that is regulated by the EGFR-ERK axis. Taken together, these findings elucidate a new function of GRHL1 on regulating the cell cycle progression and point out the potential role of GRHL1 as a drug target in NSCLC.

scholarly journals Phaseolin Attenuates Lipopolysaccharide-Induced Inflammation in RAW 264.7 Cells and Zebrafish

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 420
Author(s):  
Su-Jung Hwang ◽  
Ye-Seul Song ◽  
Hyo-Jong Lee
Keyword(s):  
Nitric Oxide ◽  
Nuclear Translocation ◽  
Raw 264.7 Cells ◽  
Network Pharmacology ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Bioactive Constituents

Kushen (Radix Sophorae flavescentis) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of S. flavescentis. However, the role of phaseolin (one of the primary components of S. flavescentis) in the direct regulation of inflammation and inflammatory processes is not well known. In this study, the beneficial role of phaseolin against inflammation was explored in lipopolysaccharide (LPS)-induced inflammation models of RAW 264.7 macrophages and zebrafish larvae. Phaseolin inhibited LPS-mediated production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), without affecting cell viability. In addition, phaseolin suppressed pro-inflammatory mediators such as cyclooxygenase 2 (COX-2), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in a dose-dependent manner. Furthermore, phaseolin reduced matrix metalloproteinase (MMP) activity as well as macrophage adhesion in vitro and the recruitment of leukocytes in vivo by downregulating Ninjurin 1 (Ninj1), an adhesion molecule. Finally, phaseolin inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB). In view of the above, our results suggest that phaseolin could be a potential therapeutic candidate for the management of inflammation.

scholarly journals Kindlin-2 in Sertoli cells is essential for testis development and male fertility in mice

2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Xiaochun Chi ◽  
Weiwei Luo ◽  
Jiagui Song ◽  
Bing Li ◽  
Tiantian Su ◽  
...  
Keyword(s):  
Sertoli Cells ◽  
Male Fertility ◽  
Nuclear Translocation ◽  
Hippo Pathway ◽  
Reproductive Organs ◽  
Male Reproduction ◽  
Barrier Structure ◽  
Male Mice ◽  
Sperm Development

AbstractKindlin-2 is known to play important roles in the development of mesoderm-derived tissues including myocardium, smooth muscle, cartilage and blood vessels. However, nothing is known for the role of Kindlin-2 in mesoderm-derived reproductive organs. Here, we report that loss of Kindlin-2 in Sertoli cells caused severe testis hypoplasia, abnormal germ cell development and complete infertility in male mice. Functionally, loss of Kindlin-2 inhibits proliferation, increases apoptosis, impairs phagocytosis in Sertoli cells and destroyed the integration of blood-testis barrier structure in testes. Mechanistically, Kindlin-2 interacts with LATS1 and YAP, the key components of Hippo pathway. Kindlin-2 impedes LATS1 interaction with YAP, and depletion of Kindlin-2 enhances LATS1 interaction with YAP, increases YAP phosphorylation and decreases its nuclear translocation. For clinical relevance, lower Kindlin-2 expression and decreased nucleus localization of YAP was found in SCOS patients. Collectively, we demonstrated that Kindlin-2 in Sertoli cells is essential for sperm development and male reproduction.

scholarly journals A Yes-Associated Protein (YAP) and Insulin-Like Growth Factor 1 Receptor (IGF-1R) Signaling Loop Is Involved in Sorafenib Resistance in Hepatocellular Carcinoma

Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3812
Author(s):  
Mai-Huong T. Ngo ◽  
Sue-Wei Peng ◽  
Yung-Che Kuo ◽  
Chun-Yen Lin ◽  
Ming-Heng Wu ◽  
...  
Keyword(s):  
Nuclear Translocation ◽  
Combination Index ◽  
Specific Inhibitor ◽  
In Vivo Model ◽  
Mrna Levels ◽  
Margin Distribution ◽  
Related Proteins ◽  
Emt Markers

The role of a YAP-IGF-1R signaling loop in HCC resistance to sorafenib remains unknown. Method: Sorafenib-resistant cells were generated by treating naïve cells (HepG2215 and Hep3B) with sorafenib. Different cancer cell lines from databases were analyzed through the ONCOMINE web server. BIOSTORM–LIHC patient tissues (46 nonresponders and 21 responders to sorafenib) were used to compare YAP mRNA levels. The HepG2215_R-derived xenograft in SCID mice was used as an in vivo model. HCC tissues from a patient with sorafenib failure were used to examine differences in YAP and IGF-R signaling. Results: Positive associations exist among the levels of YAP, IGF-1R, and EMT markers in HCC tissues and the levels of these proteins increased with sorafenib failure, with a trend of tumor-margin distribution in vivo. Blocking YAP downregulated IGF-1R signaling-related proteins, while IGF-1/2 treatment enhanced the nuclear translocation of YAP in HCC cells through PI3K-mTOR regulation. The combination of YAP-specific inhibitor verteporfin (VP) and sorafenib effectively decreased cell viability in a synergistic manner, evidenced by the combination index (CI). Conclusion: A YAP-IGF-1R signaling loop may play a role in HCC sorafenib resistance and could provide novel potential targets for combination therapy with sorafenib to overcome drug resistance in HCC.

scholarly journals AIF3 splicing switch triggers neurodegeneration

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Shuiqiao Liu ◽  
Mi Zhou ◽  
Zhi Ruan ◽  
Yanan Wang ◽  
Calvin Chang ◽  
...  
Keyword(s):  
Cell Death ◽  
Neurodegenerative Diseases ◽  
Mitochondrial Dysfunction ◽  
Nuclear Translocation ◽  
Chromatin Condensation ◽  
Neuronal Cell ◽  
Adult Brain ◽  
Postmortem Brain ◽  
Mitochondrial Functions

Abstract Background Apoptosis-inducing factor (AIF), as a mitochondrial flavoprotein, plays a fundamental role in mitochondrial bioenergetics that is critical for cell survival and also mediates caspase-independent cell death once it is released from mitochondria and translocated to the nucleus under ischemic stroke or neurodegenerative diseases. Although alternative splicing regulation of AIF has been implicated, it remains unknown which AIF splicing isoform will be induced under pathological conditions and how it impacts mitochondrial functions and neurodegeneration in adult brain. Methods AIF splicing induction in brain was determined by multiple approaches including 5′ RACE, Sanger sequencing, splicing-specific PCR assay and bottom-up proteomic analysis. The role of AIF splicing in mitochondria and neurodegeneration was determined by its biochemical properties, cell death analysis, morphological and functional alterations and animal behavior. Three animal models, including loss-of-function harlequin model, gain-of-function AIF3 knockin model and conditional inducible AIF splicing model established using either Cre-loxp recombination or CRISPR/Cas9 techniques, were applied to explore underlying mechanisms of AIF splicing-induced neurodegeneration. Results We identified a nature splicing AIF isoform lacking exons 2 and 3 named as AIF3. AIF3 was undetectable under physiological conditions but its expression was increased in mouse and human postmortem brain after stroke. AIF3 splicing in mouse brain caused enlarged ventricles and severe neurodegeneration in the forebrain regions. These AIF3 splicing mice died 2–4 months after birth. AIF3 splicing-triggered neurodegeneration involves both mitochondrial dysfunction and AIF3 nuclear translocation. We showed that AIF3 inhibited NADH oxidase activity, ATP production, oxygen consumption, and mitochondrial biogenesis. In addition, expression of AIF3 significantly increased chromatin condensation and nuclear shrinkage leading to neuronal cell death. However, loss-of-AIF alone in harlequin or gain-of-AIF3 alone in AIF3 knockin mice did not cause robust neurodegeneration as that observed in AIF3 splicing mice. Conclusions We identified AIF3 as a disease-inducible isoform and established AIF3 splicing mouse model. The molecular mechanism underlying AIF3 splicing-induced neurodegeneration involves mitochondrial dysfunction and AIF3 nuclear translocation resulting from the synergistic effect of loss-of-AIF and gain-of-AIF3. Our study provides a valuable tool to understand the role of AIF3 splicing in brain and a potential therapeutic target to prevent/delay the progress of neurodegenerative diseases.

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