scholarly journals Investigating polystyrene nanoplastics-induced reproductive toxicity in vitro: Focus on Nrf2-PKM2-autophagy signaling pathway

2021 ◽  
Author(s):  
Siwen Li ◽  
Yu Ma ◽  
Shuzi Ye ◽  
Ying Su ◽  
Die Hu ◽  
...  
Keyword(s):  
Reproductive Toxicity ◽  
Environmental Pollutant ◽  
Nuclear Accumulation ◽  
Seminiferous Tubules ◽  
Related Factor ◽  
Mitochondrial Apoptosis ◽  
Inverted Microscope ◽  
Toxicity In Vitro ◽  
Nrf2 Protein

Abstract As an issue of widespread concern, microplastics pollution has emerged as a harmful environmental pollutant. Nanoplastics (NaPs) has reported to accumulate in the testes and cause degeneration in the seminiferous tubules. However, the current research involving NaPs-induced reproductive toxicity remains poorly understood. The current work aimed to investigate the mechanisms of NaPs-induced reproductive injury in vitro. At first, we found that 80 nm fluorescent NaPs could enter into GC-2spd(ts) cells by fluorescent inverted microscope. Our results also demonstrated that suppression of reactive oxygen species (ROS) inhibited NaPs-triggered mitochondrial apoptosis and autophagy in GC-2spd(ts) cells. We also found that NaPs treatment did not change the interaction between nuclear factor erythroid-derived 2-related factor (Nrf2) and Kelch-like ECH associated protein 1 (Keap1), while inhibiting nuclear accumulation of Nrf2 protein. Further in vitro experiments showed that NaPs-induced reproductive toxicity associated with reducing dimerize pyruvate kinase M2 (PKM2), which are ascribed to the loss of Nrf2. Meanwhile, improving nuclear accumulation of Nrf2 might interact with PKM2 to rescue mitochondrial apoptosis caused by NaPs. Together, this study highlight that disturbing Nrf2-PKM2 signaling is essential process of NaPs-induced reproductive toxicity and provide valuable insights into the mechanism of microplastics-induced reproductive toxicity.

scholarly journals Curcumin Protects Human Keratinocytes against Inorganic Arsenite-Induced Acute Cytotoxicity through an NRF2-Dependent Mechanism

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Rui Zhao ◽  
Bei Yang ◽  
Linlin Wang ◽  
Peng Xue ◽  
Baocheng Deng ◽  
...  
Keyword(s):  
Inorganic Arsenic ◽  
Human Keratinocytes ◽  
Antioxidant Response ◽  
Nuclear Accumulation ◽  
Related Factor ◽  
High Concentration ◽  
Low Concentrations ◽  
Acute Cytotoxicity ◽  
Nrf2 Protein ◽  
Dependent Mechanism

Human exposure to inorganic arsenic leads to various dermal disorders, including hyperkeratosis and skin cancer. Curcumin is demonstrated to induce remarkable antioxidant activity in a variety of cells and tissues. The present study aimed at identifying curcumin as a potent activator of nuclear factor erythroid 2-related factor 2 (NRF2) and demonstrating its protective effect against inorganic arsenite- (iAs3+-) induced cytotoxicity in human keratinocytes. We found that curcumin led to nuclear accumulation of NRF2 protein and increased the expression of antioxidant response element- (ARE-) regulated genes in HaCaT keratinocytes in concentration- and time-dependent manners. High concentration of curcumin (20 μM) also increased protein expression of long isoforms of NRF1. Treatment with low concentrations of curcumin (2.5 or 5 μM) effectively increased the viability and survival of HaCaT cells against iAs3+-induced cytotoxicity as assessed by the MTT assay and flow cytometry and also attenuated iAs3+-induced expression of cleaved caspase-3 and cleaved PARP protein. Selective knockdown ofNRF2orKEAP1by lentiviral shRNAs significantly diminished the cytoprotection conferred by curcumin, suggesting that the protection against iAs3+-induced cytotoxicity is dependent on the activation of NRF2. Our results provided a proof of the concept of using curcumin to activate the NRF2 pathway to alleviate arsenic-induced dermal damage.

scholarly journals 275.Calmodulin-dependent nuclear import pathway of the testis-determining factor SRY

2004 ◽  
Vol 16 (9) ◽  
pp. 275
Author(s):  
G. Kaur ◽  
A. Delluc-Clavieres ◽  
I. Poon ◽  
D. A. Jans
Keyword(s):  
Nuclear Import ◽  
Protein Import ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Gonadal Development ◽  
Nuclear Accumulation ◽  
Related Factor ◽  
Testis Development ◽  
New Findings

Modulation of the nuclear entry of transcription factors (TFs) and chromatin components is a means by which eukaryotic cells can regulate gene expression in response to extracellular signals and the cell cycle during differentiation and development. TFs and chromatin components access the nucleus through nuclear localisation sequences (NLSs), which mediate interaction with components of the cellular nuclear import machinery, such as members of the importin superfamily. The Ca2+-binding protein calmodulin (CaM ) has previously been shown to bind at or near NLSs in several nuclear-localising proteins that have important roles in testis development including the Y chromosome-encoded HMG-domain-carrying chromatin remodelling factor SRY, and related factor SOX9, both of which are key regulators of gonadal development. SRY function in the nucleus of somatic cells of the fetal gonad, in particular, is essential for development of a testis in males. Here we present new findings implicating a role for CaM in modulating SRY nuclear accumulation, whereby treatment of transfected cells with CaM antagonists significantly reduces nuclear accumulation of green fluorescent protein (GFP)-fusion proteins encoding either full length SRY or the SRY HMG domain alone. An in vitro nuclear transport assay using bacterially expressed fluorescent proteins showed similar results, with native gel electrophoresis/fluorimaging and fluorescence polarisation assays, indicating direct binding of CaM to the SRY HMG domain in Ca2+-dependent fashion. Since clinical mutations resulting in sex reversal occur within SRY's CaM-binding NLS, these results may shed new insight into CaM-dependent pathways of nuclear protein import, and how this may relate to testis development.

Abstract 80: Activation of Nrf2 by Sulforaphane via the AKT/GSK-3β/Fyn Pathway Prevents Angiotensin II-induced Cardiomyopathy

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Ying Xin ◽  
Yang Bai ◽  
Xin Jiang ◽  
Shanshan Zhou ◽  
Yuehui Wang ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Glycogen Synthase ◽  
Critical Role ◽  
Nuclear Accumulation ◽  
Related Factor ◽  
Ang Ii ◽  
H9c2 Cells ◽  
Cardiac Damage ◽  
Gsk 3Β

Aims: Sulforaphane (SFN) as a nuclear factor erythroid 2-related factor 2 (Nrf2) activator protects the heart from, and deletion of the Nrf2 gene exaggerates, the effects of diabetes. Angiotensin II (Ang II) plays a critical role in the development of diabetic cardiomyopathy; therefore, whether SFN prevents Ang II-induced cardiomyopathy through activation of Nrf2 was examined. Methods and Results: The chronic cardiac effects of Ang II with and without SFN were examined in wild-type mice, transgenic Nrf2 knockout (Nrf2-KO) mice, and mice in which cardiac tissue overexpressed Nrf2 (Nrf2-TG). The signaling pathways of SFN-mediated Nrf2 activation were examined in H9C2 cells. Administration of a subpressor dose of Ang II to WT mice induced cardiac oxidative stress, inflammation, remodeling and dysfunction, all of which could be prevented by SFN treatment, which also up-regulated Nrf2 expression and activation. Nrf2-TG mice showed resistance and Nrf2-KO mice displayed resistance to Ang II-induced cardiomyopathy. Meanwhile, the ability of SFN to protect against Ang II-induced cardiac damage was lost in Nrf2-KO mice. Up-regulation and activation of Nrf2 by SFN is accompanied by activation of AKT, inhibition of glycogen synthase kinase (GSK)-3β, and increased nuclear accumulation of Fyn. In vitro up-regulation of Nrf2 by SFN in H9C2 cells was abolished and nuclear Fyn accumulation was increased when cells were exposed to a PI3K inhibitor or GSK-3β-specific activator. Conclusion: Nrf2 plays a central role in the prevention of Ang II-induced pathological effects, and SFN can prevent Ang II-induced cardiomyopathy through activation of Nrf2 partially via the AKT/GSK-3β/Fyn pathway.

scholarly journals AMPK Facilitates Nuclear Accumulation of Nrf2 by Phosphorylating at Serine 550

2016 ◽  
Vol 36 (14) ◽  
pp. 1931-1942 ◽  
Author(s):  
Min Sung Joo ◽  
Won Dong Kim ◽  
Ki Young Lee ◽  
Ji Hyun Kim ◽  
Ja Hyun Koo ◽  
...  
Keyword(s):  
Cell Survival ◽  
Nuclear Export ◽  
Glycogen Synthase ◽  
Nuclear Export Signal ◽  
Direct Interaction ◽  
Antioxidant Response ◽  
Nuclear Accumulation ◽  
Related Factor ◽  
Ampk Activation

Nrf2 (nuclear factor erythroid 2-related factor 2) is an antioxidant transcription factor. AMP-activated protein kinase (AMPK) functions as a central regulator of cell survival in response to stressful stimuli. Nrf2 should be coordinated with the cell survival pathway controlled by AMPK, but so far the mechanistic connections remain undefined. This study investigated the role of AMPK in Nrf2 trafficking and its activity regulation. A subnetwork integrating neighbor molecules suggested direct interaction between AMPK and Nrf2. In cells, AMPK activation caused nuclear accumulation of Nrf2. In thein vitrokinase and peptide competition assays, AMPK phosphorylated Nrf2 at the Ser558 residue (Ser550 in mouse) located in the canonical nuclear export signal. Nrf2 with an S550A mutation failed to be accumulated in the nucleus after AMPK activation. Leptomycin B, a nuclear export inhibitor, did not enhance nuclear accumulation of wild-type Nrf2 (WT-Nrf2) activated by AMPK or a phospho-Ser550-mimetic Nrf2 mutant, corroborating the finding that AMPK facilitated nuclear accumulation of Nrf2, probably by inhibiting nuclear export. Activated glycogen synthase kinase 3β (GSK3β) diminished the basal nuclear level of Myc-S550A-Nrf2. Taking the data collectively, AMPK phosphorylates Nrf2 at the Ser550 residue, which, in conjunction with AMPK-mediated GSK3β inhibition, promotes nuclear accumulation of Nrf2 for antioxidant response element (ARE)-driven gene transactivation.

scholarly journals Triptolide Induces Leydig Cell Apoptosis by Disrupting Mitochondrial Dynamics in Rats

2021 ◽  
Vol 12 ◽  
Author(s):  
Linyan Lv ◽  
Yajie Chang ◽  
Yanqing Li ◽  
Haicheng Chen ◽  
Jiahui Yao ◽  
...  
Keyword(s):  
Leydig Cell ◽  
Cell Apoptosis ◽  
Mitochondrial Dynamics ◽  
Reproductive Toxicity ◽  
Mitochondrial Apoptosis ◽  
Mitochondrial Dynamic ◽  
Apoptosis Pathway ◽  
Mitochondrial Apoptosis Pathway

Triptolide is widely used in the clinical treatment of various diseases. Side effects, including reproductive toxicity to male patients, limit its application. However, no detailed mechanisms or potential intervention targets have been reported. In this study, we show that triptolide activated the mitochondrial apoptosis pathway in rat testicular Leydig cells and induced apoptosis both in vivo and in vitro, which may cause hypoleydigism and impair spermatogenesis. Mechanistically, triptolide-induced dynamin-related protein 1 (Drp1) overexpression, which interfered with mitochondrial dynamic stability to activate the mitochondrial apoptosis pathway. Mdivi-1, a selective Drp1 inhibitor, partially reversed the mitochondrial dynamic disturbance and rat testicular Leydig cell apoptosis induced by triptolide. Inhibiting Drp1 over-activation may be a new strategy for mitigating the reproductive toxicity of triptolide.

1-Bromopropane-induced apoptosis in OVCAR-3 cells via oxidative stress and inactivation of Nrf2

2020 ◽  
pp. 074823372097942
Author(s):  
Guangtao Yang ◽  
Yingping Xiang ◽  
Wei Zhou ◽  
Xiaohuan Zhong ◽  
Yanfang Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathway ◽  
Reproductive Toxicity ◽  
Antioxidant Vitamin ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Ovarian Carcinoma Cell Line ◽  
Nrf2 Signaling Pathway ◽  
Induced Apoptosis

The bromoalkane, 1-bromopropane (1-BP), may damage the reproductive system though oxidative stress, while the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) plays an important role in regulating intracellular antioxidant levels against oxidative stress. This study explored the role of oxidative stress and the Nrf2 signaling pathway in mediating the reproductive toxicity of 1-BP using the ovarian carcinoma cell line OVCAR-3 as an in vitro model of the human ovary. OVCAR-3 cells were treated with 1, 5, 10 and 15 mM 1-BP. After 24 h, the cellular reactive oxygen species and malondialdehyde concentrations significantly increased, while the superoxide dismutase activity decreased; translocation of Nrf2 from the cytosol to the nucleus as well as downstream protein expression of Nrf2-regulated genes heme oxygenase-1 and Bcl-2 was inhibited. Apoptosis was also observed, accompanied by increased caspase-3 and caspase-9 activity. The antioxidant vitamin C alleviated 1-BP-induced apoptosis by inhibiting caspase activity activating the Nrf2 signaling pathway. These findings suggested that 1-BP induced oxidative stress and apoptosis in OVCAR-3 cells through inactivation of Nrf2 signaling.

scholarly journals Oxidative and Electrophilic Stresses Activate Nrf2 through Inhibition of Ubiquitination Activity of Keap1

2006 ◽  
Vol 26 (1) ◽  
pp. 221-229 ◽  
Author(s):  
Akira Kobayashi ◽  
Moon-Il Kang ◽  
Yoriko Watai ◽  
Kit I. Tong ◽  
Takahiro Shibata ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
De Novo ◽  
Degradation Mechanism ◽  
Nuclear Accumulation ◽  
Protein Synthesis Inhibitor ◽  
Synthesis Inhibitor ◽  
Nrf2 Activation ◽  
Nrf2 Protein

ABSTRACT The Keap1-Nrf2 system is the major regulatory pathway of cytoprotective gene expression against oxidative and/or electrophilic stresses. Keap1 acts as a stress sensor protein in this system. While Keap1 constitutively suppresses Nrf2 activity under unstressed conditions, oxidants or electrophiles provoke the repression of Keap1 activity, inducing the Nrf2 activation. However, the precise molecular mechanisms behind the liberation of Nrf2 from Keap1 repression in the presence of stress remain to be elucidated. We hypothesized that oxidative and electrophilic stresses induce the nuclear accumulation of Nrf2 by affecting the Keap1-mediated rapid turnover of Nrf2, since such accumulation was diminished by the protein synthesis inhibitor cycloheximide. While both the Cys273 and Cys288 residues of Keap1 are required for suppressing Nrf2 nuclear accumulation, treatment of cells with electrophiles or mutation of these cysteine residues to alanine did not affect the association of Keap1 with Nrf2 either in vivo or in vitro. Rather, these treatments impaired the Keap1-mediated proteasomal degradation of Nrf2. These results support the contention that Nrf2 protein synthesized de novo after exposure to stress accumulates in the nucleus by bypassing the Keap1 gate and that the sensory mechanism of oxidative and electrophilic stresses is closely linked to the degradation mechanism of Nrf2.

scholarly journals The Protective Effect of Polyherbal Formulation, Harak Formula, on UVA-Induced Photoaging of Human Dermal Fibroblasts and Mouse Skin via Promoting Nrf2-Regulated Antioxidant Defense

2021 ◽  
Vol 12 ◽  
Author(s):  
Jinapath Lohakul ◽  
Anyamanee Chaiprasongsuk ◽  
Saowanee Jeayeng ◽  
Malinee Saelim ◽  
Phetthinee Muanjumpon ◽  
...  
Keyword(s):  
Mouse Skin ◽  
Dermal Fibroblasts ◽  
Antioxidant Defenses ◽  
Nuclear Accumulation ◽  
Therapeutic Effects ◽  
Related Factor ◽  
Human Dermal Fibroblasts ◽  
Polyherbal Formulation ◽  
Ros Formation

Polyherbal formulation combining multiple herbs is suggested to achieve enhanced therapeutic effects and reduce toxicity. Harak herbal formula (HRF) extracts were proposed to regulate skin responses to UVR through their ability to suppress UVA-induced matrix metalloproteinase-1 (MMP-1) and pigmentation via promoting antioxidant defenses in in vitro models. Therefore, natural products targeting Nrf2 (nuclear factor erythroid 2-related factor 2)-regulated antioxidant response might represent promising anti-photoaging candidates. Hesperetin (HSP) was suggested as a putative bioactive compound of the HRF, as previously shown by its chemical profiling using the liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). In this study, we explored the anti-photoaging effects of HRF extracts and HSP on normal human dermal fibroblasts (NHDFs) and mouse skin exposed to UVA irradiation. Pretreatment of NHDFs with HRF extracts and HSP protected against UVA (8 J/cm2)-mediated cytotoxicity and reactive oxygen species (ROS) formation. The HRF and HSP pretreatment also attenuated the UVA-induced MMP-1 activity and collagen depletion concomitant with an upregulation of Nrf2 activity and its downstream genes (GST and NQO-1). Moreover, our findings provided the in vivo relevance to the in vitro anti-photoaging effects of HRF as topical application of the extracts (10, 30 and 100 mg/cm2) and HSP (0.3, 1, and 3 mg/cm2) 1 h before UVA exposure 3 times per week for 2 weeks (a total dose of 60 J/cm2) mitigated MMP-1 upregulation, collagen loss in correlation with enhanced Nrf2 nuclear accumulation and its target protein GST and NQO-1 as well as reduced 8-hydroxy-2′-deoxyguanosine (8-OHdG) in irradiated mouse skin. Thus, our findings revealed that HRF extracts and HSP attenuated UVA-induced photoaging via upregulating Nrf2, together with their abilities to reduce ROS formation and oxidative damage. Our study concluded that the HRF and its bioactive ingredient HSP may represent potential candidates for preventing UVA-induced photoaging via restoration of redox balance.

Astrocytic Expression of the Immunoreceptor CD300f Protects Hippocampal Neurons from Amyloid-β Oligomer Toxicity In Vitro

2017 ◽  
Vol 14 (7) ◽  
Author(s):  
Thiago Zaqueu Lima ◽  
Luis Roberto Sardinha ◽  
Joan Sayos ◽  
Luiz Eugenio Mello ◽  
Hugo Peluffo
Keyword(s):  
Hippocampal Neurons ◽  
Amyloid Β ◽  
Toxicity In Vitro

Derivatives of Deoxypodophyllotoxin Induce Apoptosis Through Bcl-2/Bax Proteins Expression

2020 ◽  
Vol 20 ◽  
Author(s):  
Ya-Nan Li ◽  
Ni Ning ◽  
Lei Song ◽  
Yun Geng ◽  
Jun-Ting Fan ◽  
...  
Keyword(s):  
Annexin V ◽  
Mtt Method ◽  
Anthriscus Sylvestris ◽  
Anti Tumor Activity ◽  
Derivatives Of ◽  
Toxicity In Vitro ◽  
Ht 29 ◽  
Mcf 7

Background: Deoxypodophyllotoxin, isolated from theTraditional Chinese Medicine Anthriscus sylvestris, is well-known because of its significant antitumor activity with strong toxicity in vitro and in vivo. Objective: In this article, we synthesized a series of deoxypodophyllotoxin derivatives, and evaluated their antitumor effectiveness.Methods:The anti tumor activity of deoxypodophyllotoxin derivatives was investigated by the MTT method. Apoptosis percentage was measured by flow cytometer analysis using Annexin-V-FITC. Results: The derivatives revealed obvious cytotoxicity in the MTT assay by decreasing the number of late cancer cells. The decrease of Bcl-2/Bax could be observed in MCF-7, HepG2, HT-29 andMG-63 using Annexin V-FITC. The ratio of Bcl-2/Bax in the administration group was decreased, which was determined by the ELISA kit. Conclusion: The derivatives of deoxypodophyllotoxin could induce apoptosis in tumor cell lines by influencing Bcl-2/Bax.

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