scholarly journals METTL3-mediated m6A methylation negatively modulates autophagy to support porcine blastocyst development‡

Author(s):  
Zubing Cao ◽  
Ling Zhang ◽  
Renyun Hong ◽  
Yunsheng Li ◽  
Yiqing Wang ◽  
...  

Abstract N6-methyladenosine (m6A) catalyzed by METTL3 regulates the maternal-to-zygotic transition in zebrafish and mice. However, the role and mechanism of METTL3-mediated m6A methylation in blastocyst development remains unclear. Here, we show that METTL3-mediated m6A methylation sustains porcine blastocyst development via negatively modulating autophagy. We found that reduced m6A levels triggered by METTL3 knockdown caused embryonic arrest during morula-blastocyst transition and developmental defects in trophectoderm cells. Intriguingly, overexpression of METTL3 in early embryos resulted in increased m6A levels and these embryos phenocopied METTL3 knockdown embryos. Mechanistically, METTL3 knockdown or overexpression resulted in a significant increase or decrease in expression of ATG5 (a key regulator of autophagy) and LC3 (an autophagy marker) in blastocysts, respectively. m6A modification of ATG5 mRNA mainly occurs at 3’UTR, and METTL3 knockdown enhanced ATG5 mRNA stability, suggesting that METTL3 negatively regulated autophagy in an m6A dependent manner. Furthermore, single-cell qPCR revealed that METTL3 knockdown only increased expression of LC3 and ATG5 in trophectoderm cells, indicating preferential inhibitory effects of METTL3 on autophagy activity in the trophectoderm lineage. Importantly, autophagy restoration by 3MA (an autophagy inhibitor) treatment partially rescued developmental defects of METTL3 knockdown blastocysts. Taken together, these results demonstrate that METTL3-mediated m6A methylation negatively modulates autophagy to support blastocyst development.

2020 ◽  
Author(s):  
Zubing Cao ◽  
Ling Zhang ◽  
Renyun Hong ◽  
Yiqing Wang ◽  
Xin Qi ◽  
...  

Abstract Background: N6-methyladenosine (m6A) catalyzed by METTL3 regulates the maternal-to-zygotic transition in zebrafish and mice. However, the role and mechanism of METTL3-mediated m6A methylation in blastocyst development remains unclear. Results: We found that reduced m6A levels triggered by METTL3 knockdown caused embryonic arrest during morula-blastocyst transition and developmental defects in trophectoderm cells. Intriguingly, overexpression of METTL3 in early embryos resulted in increased m6A levels and these embryos phenocopied METTL3 knockdown embryos. Mechanistically, METTL3 knockdown or overexpression resulted in a significant increase or decrease in expression of ATG5 and LC3 (an autophagy marker) in blastocysts, respectively. m6A modification of ATG5 mRNA mainly occurs at 3’UTR, and METTL3 knockdown enhanced ATG5 mRNA stability, suggesting that METTL3 negatively regulated autophagy in an m6A dependent manner. Furthermore, single-cell analysis revealed that METTL3 knockdown only increased expression of LC3 and ATG5 in trophectoderm cells, indicating preferential inhibitory effects of METTL3 on autophagy activity in the trophectoderm lineage. Importantly, autophagy restoration by 3MA (an autophagy inhibitor) treatment partially rescued developmental defects of METTL3 knockdown blastocysts. Conclusions: Our results demonstrate that METTL3-mediated m6A methylation negatively modulates autophagy to support blastocyst development.


1984 ◽  
Vol 193 (3) ◽  
pp. 164-179 ◽  
Author(s):  
Kenneth T. R. Denich ◽  
Einhard Schierenberg ◽  
Edoardo Isnenghi ◽  
Randall Cassada

1998 ◽  
Vol 157 (2) ◽  
pp. 209-215 ◽  
Author(s):  
AE Calogero ◽  
N Burrello ◽  
AM Ossino

Endothelin (ET)-1 and ET-3, two peptides with a potent vasoconstrictive property, produce a variety of biological effects in different tissues by acting through two different receptors, the ET-1 selective ET(A) receptor and the non-selective ETB receptor. An increasing body of literature suggests that ET-1 acts as a paracrine/autocrine regulator of ovarian function. Indeed, ETB receptors have been identified in rat granulosa cells and ET-1 is a potent inhibitor of progesterone production. In contrast, inconsistent data have been reported about the role of ET-1 on estrogen production and the effects of ET-3 are not known. Therefore, the present study was undertaken to evaluate the effects of ET-1 and ET-3 on estrogen and cAMP production, and the receptor type involved. Given that prostanoids modulate ovarian steroidogenesis and that many actions of ETs are mediated by these compounds, we also evaluated whether the effects of ETs on estrogen and cAMP production might be prostanoid-mediated. ET-1, ET-3, and safarotoxin-S6c (SFX-S6c), a selective ETB receptor agonist, inhibited basal estrogen production by granulosa cells obtained from immature, estrogen-primed female rats, in a concentration-dependent manner. All three peptides were also capable of inhibiting the production of estrogen stimulated by a half-maximal (1 mIU/ml) and a maximally stimulatory (3 mIU/ml) concentration of FSH, ET-1 and ET-3 dose-dependently suppressed basal and FSH (1 mIU/ml)-stimulated cAMP production. ET-3 and SFX-S6c were significantly more potent than ET-1 in suppressing estrogen production, suggesting that this effect was not mediated by the ET(A) receptor. Indeed, BQ-123, a selective ET(A) receptor antagonist, did not influence the inhibitory effects of ET-1 and ET-3 on basal and FSH-stimulated estrogen release. To determine a possible involvement of prostanoids, we evaluated the effects of maximally effective concentrations of ET-1 and ET-3 on estrogen and cAMP production in the presence of indomethacin, a prostanoid synthesis inhibitor. This compound did not have any effect on the suppressive effects of ETs on basal or FSH (1 mIU/ml)-stimulated estrogen or cAMP production. In conclusion, ET-1 and ET-3 were able to inhibit estrogen and cAMP production by rat granulosa cells, indicating that the inhibitory effects of ETs on ovarian steroidogenesis are not limited to progesterone biosynthesis. This effect does not appear to be mediated by prostanoids or by the classical ET(A) and ETB receptors, at least under these experimental conditions.


2021 ◽  
Vol 19 (3) ◽  
pp. 355-363
Author(s):  
Jung-Wook Kang ◽  
In-Chul Lee

Purpose: This study aimed to investigate the effects of the Cassia obtusifolia L. seed extract (CSE) on particulate matter (PM)-induced skin.Methods: The effects of CSE on cell viability were evaluated using a skin cell line. To determine the anti-inflammatory effects and matrix metallopeptidase-1 (MMP-1)-inhibitory effects of CSE on PM-induced skin, NO and MMP-1 expressions were measured using an enzyme-linked immunosorbent assay (ELISA) kit. Also, the effects of CSE was investigated the induction of IL-8 and TNF-α treated PM on reconstructed human full thickness skin models.Results: It was observed that CSE decreased NO production in PM-induced RAW 264.7 cells without cytotoxicity. In addition, CSE decreased the expression of MMP-1 in PM-induced cells in a dose-dependent manner. CSE decreased IL-8 and TNF-α production in a PM-reconstructed human skin model.Conclusion: These results indicate that CSE could be used as a cosmetic material to induce anti-inflammation and inhibition of MMP-1 in PM-induced skin.


2018 ◽  
Vol 115 (15) ◽  
pp. 3930-3935 ◽  
Author(s):  
Dongshi Chen ◽  
Jingshan Tong ◽  
Liheng Yang ◽  
Liang Wei ◽  
Donna B. Stolz ◽  
...  

Necroptosis, a form of regulated necrotic cell death, is governed by RIP1/RIP3-mediated activation of MLKL. However, the signaling process leading to necroptotic death remains to be elucidated. In this study, we found that PUMA, a proapoptotic BH3-only Bcl-2 family member, is transcriptionally activated in an RIP3/MLKL-dependent manner following induction of necroptosis. The induction of PUMA, which is mediated by autocrine TNF-α and enhanced NF-κB activity, contributes to necroptotic death in RIP3-expressing cells with caspases inhibited. On induction, PUMA promotes the cytosolic release of mitochondrial DNA and activation of the DNA sensors DAI/Zbp1 and STING, leading to enhanced RIP3 and MLKL phosphorylation in a positive feedback loop. Furthermore, deletion of PUMA partially rescues necroptosis-mediated developmental defects in FADD-deficient embryos. Collectively, our results reveal a signal amplification mechanism mediated by PUMA and cytosolic DNA sensors that is involved in TNF-driven necroptotic death in vitro and in vivo.


Development ◽  
1985 ◽  
Vol 90 (1) ◽  
pp. 197-209
Author(s):  
E. Lehtonen

Monoclonal antibodies were raised to detergent-extracted cytoskeleton preparations of mouse oocytes. In immunofluorescence microscopy, one of the antibodies, OCS-1, localizes exclusively to epithelial cells in frozen tissue sections, including various simple and stratified epithelia. The antibody decorates a keratin-type of fibrillax, vinblastine-resistant network in various cultured, epithelial-type cells, but not in myoid or fibroblastoid cells. In mouse oocytes and cleavage-stage embryos, the OCS-1 antibody gives a diffuse, spotty staining pattern. In blastocyst-stage embryos, the antibody reveals a keratin-type filamentous organization in the trophectoderm cells. In immunoelectron microscopy, the OCS-1 antibody decorates 10 nm-thick filaments, often identifiable as desmosome-attached tonofilaments, in detergent-treated trophectoderm cells. The antigen(s) recognized by the OCS-1 antibody is apparently present in, or closely associated with, cytokeratin filaments. In addition to mouse oocytes and early embryos, a wide variety of epithelial cells in various species seem to share this antigen(s). The present results suggest that at the early stages, the cytokeratin-related antigen(s) defined by the OCS-1 antibody are stored in a non-fibrillar form which is then converted into a fibrillar network at the blastocyst stage. A pre-existing supply of cytokeratin-related protein may be essential for the development of the blastocyst.


2020 ◽  
Vol 26 (2) ◽  
pp. 287-296
Author(s):  
Kyung-Tae Shin ◽  
Zheng-Wen Nie ◽  
Wenjun Zhou ◽  
Dongjie Zhou ◽  
Ju-Yeon Kim ◽  
...  

AbstractConnexin 43 (CX43) is a component of gap junctions. The lack of functional CX43 induces oxidative stress, autophagy, and apoptosis in somatic cells. However, the role of CX43 in the early development of porcine embryos is still unknown. Thus, the aim of this study was to investigate the role of CX43, and its underlying molecular mechanisms, on the developmental competence of early porcine embryos. We performed CX43 knockdown by microinjecting dsRNA into parthenogenetically activated porcine parthenotes. The blastocyst development rate and the total number of cells in the blastocysts were significantly reduced by CX43 knockdown. Results from FITC-dextran assays showed that CX43 knockdown significantly increased membrane permeability. ZO-1 protein was obliterated in CX43 knockdown blastocysts. Mitochondrial membrane potential and ATP production were significantly reduced following CX43 knockdown. Reactive oxygen species (ROS) levels were significantly increased in the CX43 knockdown group compared to those in control embryos. Moreover, CX43 knockdown induced autophagy and apoptosis. Our findings indicate that CX43 is essential for the development and preimplantation of porcine embryos and maintains mitochondrial function, cell junction structure, and cell homeostasis by regulating membrane permeability, ROS generation, autophagy, and apoptosis in early embryos.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Ihcen Khacheba ◽  
Amar Djeridane ◽  
Mohamed Yousfi

In the present work, we have studied the inhibitory effects of aqueous and alcoholic extracts of six Algerian medicinal plants known by their therapeutic virtues against diabetes. The total phenolic compounds content, assayed using Folin-Ciocalteu’s reagent, of the samples ranged from 0.183 mg/g to 43.088 mg/g and from 1.197 mg/g to 7.445 mg/g, expressed as gallic acid equivalent (GAE), for the, respectively, whereas the total flavonoids concentrations, detected using 2% of the aluminium chloride, ranged from 0.41 mg/g to 11.613 mg/g and from 0.0097 mg/g to 1.591 mg/g, expressed as rutin equivalents (RE), for the aqueous and methanolic extracts, respectively. The major plants were found to inhibit enzymatic activities of Aspergillus oryzae-amylase in a concentration dependent manner. The values of the inhibition constants (Ki) have been determined according to the Dixon and Lineweaver-Burk methods. The results showed that the Ki values were less than 55 ppm for the all extracts. A strong inhibition was found in the phenolic extract of Salvia officinalis with a Ki of 8 ppm.


2004 ◽  
Vol 101 (4) ◽  
pp. 888-894 ◽  
Author(s):  
Yasushi Mio ◽  
Norio Fukuda ◽  
Yoichiro Kusakari ◽  
Yoshikiyo Amaki ◽  
Yasumasa Tanifuji ◽  
...  

Background Recent evidence suggests that ropivacaine exerts markedly less cardiotoxicity compared with bupivacaine; however, the mechanisms are not fully understood at the molecular level. Methods Isolated ferret ventricular papillary muscles were microinjected with the Ca-binding photoprotein aequorin, and intracellular Ca transients and tension were simultaneously measured during twitch in the absence and presence of bupivacaine or ropivacaine. Results Bupivacaine and ropivacaine (10, 30, and 100 microm) reduced peak systolic [Ca]i and tension in a concentration-dependent manner. The effects were significantly greater for bupivacaine, particularly on tension (approximately twofold). The percentage reduction of tension was linearly correlated with that of [Ca]i for both anesthetics, with the slope of the relationship being approximately equal to 1.0 for ropivacaine and approximately equal to 1.3 for bupivacaine (slope difference, P < 0.05), suggesting that the cardiodepressant effect of ropivacaine results predominantly from inhibition of Ca transients, whereas bupivacaine suppresses Ca transients and the reaction beyond Ca transients, i.e., myofibrillar activation, as well. BAY K 8644, a Ca channel opener, abolished the inhibitory effects of ropivacaine on Ca transients and tension, whereas BAY K 8644 only partially inhibited the effects of bupivacaine, particularly the effects on tension. Conclusion The cardiodepressant effect of bupivacaine is approximately twofold greater than that of ropivacaine. Bupivacaine suppresses Ca transients more markedly than does ropivacaine and reduces myofibrillar activation, which may at least in part underlie the greater inhibitory effect of bupivacaine on cardiac contractions. These results suggest that ropivacaine has a more favorable profile as a local anesthetic in the clinical settings.


Glycobiology ◽  
2018 ◽  
Vol 29 (2) ◽  
pp. 151-162 ◽  
Author(s):  
Fang-Yen Li ◽  
I-Chun Weng ◽  
Chun-Hung Lin ◽  
Mou-Chieh Kao ◽  
Ming-Shiang Wu ◽  
...  

Abstract Galectin-8, a beta-galactoside-binding lectin, is upregulated in the gastric tissues of rhesus macaques infected with Helicobacter pylori. In this study, we found that H. pylori infection triggers intracellular galectin-8 aggregation in human-derived AGS gastric epithelial cells, and that these aggregates colocalize with lysosomes. Notably, this aggregation is markedly reduced following the attenuation of host O-glycan processing. This indicates that H. pylori infection induces lysosomal damage, which in turn results in the accumulation of cytosolic galectin-8 around damaged lysosomes through the recognition of exposed vacuolar host O-glycans. H. pylori-induced galectin-8 aggregates also colocalize with autophagosomes, and galectin-8 ablation reduces the activation of autophagy by H. pylori. This suggests that galectin-8 aggregates may enhance autophagy activity in infected cells. We also observed that both autophagy and NDP52, an autophagy adapter, contribute to the augmentation of galectin-8 aggregation by H. pylori. Additionally, vacuolating cytotoxin A, a secreted H. pylori cytotoxin, may contribute to the increased galectin-8 aggregation and elevated autophagy response in infected cells. Collectively, these results suggest that H. pylori promotes intracellular galectin-8 aggregation, and that galectin-8 aggregation and autophagy may reciprocally regulate each other during infection.


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