scholarly journals Mettl14 Regulates Cardiac Ishemia/Reperfusion Injury

Author(s):  
Ping Pang ◽  
Zhezhe Qu ◽  
Shuting Yu ◽  
Xiaochen Pang ◽  
Xin Li ◽  
...  

N6-methyladenosine (m6A) methylation in RNA is a dynamic and reversible modification regulated by methyltransferases and demethylases, which has been reported to participate in many pathological processes of various diseases, including cardiac disorders. This study was designed to investigate an m6A writer Mettl14 on cardiac ischemia–reperfusion (I/R) injury and uncover the underlying mechanism. The m6A and Mettl14 protein levels were increased in I/R hearts and neonatal mouse cardiomyocytes upon oxidative stress. Mettl14 knockout (Mettl14+/−) mice showed pronounced increases in cardiac infarct size and LDH release and aggravation in cardiac dysfunction post-I/R. Conversely, adenovirus-mediated overexpression of Mettl14 markedly reduced infarct size and apoptosis and improved cardiac function during I/R injury. Silencing of Mettl14 alone significantly caused a decrease in cell viability and an increase in LDH release and further exacerbated these effects in the presence of H2O2, while overexpression of Mettl14 ameliorated cardiomyocyte injury in vitro. Mettl14 resulted in enhanced levels of Wnt1 m6A modification and Wnt1 protein but not its transcript level. Furthermore, Mettl14 overexpression blocked I/R-induced downregulation of Wnt1 and β-catenin proteins, whereas Mettl14+/− hearts exhibited the opposite results. Knockdown of Wnt1 abrogated Mettl14-mediated upregulation of β-catenin and protection against injury upon H2O2. Our study demonstrates that Mettl14 attenuates cardiac I/R injury by activating Wnt/β-catenin in an m6A-dependent manner, providing a novel therapeutic target for ischemic heart disease.

2020 ◽  
Vol 36 (11) ◽  
pp. 844-851
Author(s):  
Wei Tu ◽  
Weifeng Li ◽  
Xingen Zhu ◽  
Linlin Xu

Di-2-ethylhexyl phthalate (DEHP) has been widely used as a plasticizer in industry and can affect memory; however, the underlying mechanism remains unclear. In the present study, mouse HT22 cells, an immortalized hippocampal neuronal cell line, was utilized as an in vitro model. We showed that DEHP dramatically inhibited cell viability and increased lactate dehydrogenase (LDH) release from the cells in a dose-dependent manner, suggesting that DEHP could cause cytotoxicity of mouse HT22 cells. The protein levels of cleaved Caspase-8, cleaved Caspase-3, and Bax markedly increased in the DEHP-treated cells, whereas there was a significant decrease in the Bcl-2 protein level, implying that DEHP could induce apoptosis of mouse HT22 cells. DEHP exposure significantly increased the content of malondialdehyde, whereas it markedly decreased the level of glutathione and the activities of glutathione peroxidase and superoxide dismutase, suggesting that DEHP induced oxidative stress of the cells. Compared with the DEHP-treated group, the inhibition of cell viability and the release of LDH were rescued in the N-acetyl-l-cysteine plus DEHP group. Furthermore, inhibition of oxidative stress could rescue the induction of apoptosis by DEHP. Collectively, our results indicated that DEHP could induce apoptosis of mouse HT22 cells via oxidative stress.


2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Jialin Duan ◽  
Jia Cui ◽  
Hongnan Zheng ◽  
Miaomiao Xi ◽  
Chao Guo ◽  
...  

Background. Saponin from Aralia taibaiensis (sAT) showed excellent antioxidative effects in several models; however, its effects on brain cells were unknown to us. The present study was designed to evaluate the protective effects of sAT on ischemia/reperfusion- (I/R-) induced injury and clarify its mechanisms. Methods. In vitro, HT22 cells were pretreated with sAT and then subjected to I/R. Apoptosis rate, mitochondrial function, and antioxidant proteins were measured. To clarify the mechanisms, siRNA were used. In vivo, sAT was pretreated through intragastric administration for 7 days and the I/R model was induced. The neurobehavioral scores, infarction volumes, and some cytokines in the brain were measured. Protein levels were investigated by Western blotting. Results. The results showed that sAT treatment significantly protected cells from I/R-induced cell apoptosis and mitochondrial dysfunction. The antioxidant protein levels were increased in a dose-dependent manner. Further study revealed that sAT induced the deacetylation and phosphorylation of PGC-1α and FOXO3a. sAT treatment also induced the phosphorylation levels of Akt and the expression levels of SIRT1. Using the specific targeted siRNA transfection, the interplay relationship between Akt, SIRT1, PGC-1α, and FOXO3a was verified. Furthermore, the same protective effects were also observed in rats subjected to I/R. Conclusion. sAT protected brain cells from I/R-induced mitochondrial oxidative stress and dysfunction through regulating the Akt/SIRT1/FOXO3a/PGC-1α pathway.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Dandan Zhao ◽  
Qing Li ◽  
Qiuping Huang ◽  
Xuguang Li ◽  
Min Yin ◽  
...  

Background. The intravenous anesthetic propofol is reported to be a cardioprotective agent against ischemic-reperfusion injury in the heart. However, the regulatory mechanism still remains unclear.Methods. In this study, we used H9c2 cell line under condition of oxygen glucose deprivation (OGD) followed by reperfusion (OGD/R) to inducein vitrocardiomyocytes ischemia-reperfusion injury. Propofol (5, 10, and 20 μM) was added to the cell cultures before and during the OGD/R phases to investigate the underlying mechanism.Results. Our data showed that OGD/R decreased cell viability, and increased lactate dehydrogenase leakage, and reactive oxygen species and malondialdehyde production in H9c2 cells, all of which were significantly reversed by propofol. Moreover, we found that propofol increased both the activities and protein expressions of superoxide dismutase and catalase. In addition, propofol increased FoxO1 expression in a dose-dependent manner and inhibited p-AMPK formation significantly.Conclusions. These results indicate that the propofol might exert its antioxidative effect through FoxO1 in H9c2 cells, and it has a potential therapeutic effect on cardiac disorders involved in oxidative stress.


2020 ◽  
Vol 19 (7) ◽  
pp. 1359-1364
Author(s):  
Xu Chen ◽  
Yingjie Cao ◽  
Naifeng Guo ◽  
Guoyuan Lu

Purpose: To investigate the effect of Z-ligustilide (Z-lig) on cisplatin-induced nephrotoxicity and examine whether NRF2 signaling mediates the underlying mechanism of action.Methods: Human proximal tubular epithelial cells (HK-2) were pretreated with 20 or 100 μM Z-lig for 2 h, followed by 10 μM cisplatin treatment for 24 h. Cell viability was measured using (3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. A commercial kit was used todetermine lactate dehydrogenase (LDH) release. Apoptosis was determined by flow cytometry while Western blotting was used to evaluate protein levels. Levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GSH-Px) were assessed by enzymelinked immunosorbent assay (ELISA).Results: Cisplatin decreased HK-2 cell viability and increased LDH release, while Z-lig increased cell viability and decreased LDH release in a dose-dependent manner (p < 0.05). Moreover, Z-lig reduced cisplatin-induced apoptosis (p < 0.01), and alleviated cellular oxidative stress caused by cisplatin (p < 0.05). Furthermore, Z-lig activated NRF2/HO-1 signaling in cells treated with cisplatin (p < 0.05).Conclusion: Z-lig reduces cisplatin-induced nephrotoxicity via activation of NRF2/HO-1 signaling. Thus, Z-lig is a potential drug for the treatment of nephrotoxicity caused by cisplatin. Keywords: Z-ligustilide, Cisplatin, Nephrotoxicity, Oxidative stress, Apoptosis, Nuclear factor erythroid 2-related factor 2, Heme oxygenase-1


2007 ◽  
Vol 26 (1) ◽  
pp. 71-80
Author(s):  
Dae Y. Hwang ◽  
Kab R. Chae ◽  
Chuel K. Kim ◽  
Byoung G. Kim ◽  
Sun B. Shim ◽  
...  

Humanized transgenic mice coexpressing tetracycline-controlled transactivator ( tTA) and human cytochrome P450 1B1 (CYP1B1) ( hCYP1B1) have been created by this group. The aims of this study was to determine if 7,12-dimethylbenz[a]anthracene (DMBA) functions as testosterone or doxycycline in its ability to induce or reduce expression of hCYP1B1 or endogenous mouse CYP1B1 (mCYP1B1). This was tested in the livers by treating castrated transgenic males and hCYP1B1/luciferase-transfected cells with DMBA. Herein, DMBA-treated group exhibited (i) gradual reduction of hCYP1B1 expression at the transcript, protein, and activity levels but gradually induced its transcript level during DMBA release; (ii) gradual reduction of hCYP1B1 at the transcript and protein levels, as in the case of doxycycline or testosterone; (iii) gradual induction of mCYP1B1 expression at the transcript and protein levels but gradually reduced its transcript level during DMBA release. In parallel, DMBA-treated transfected cells exhibited gradual increase in luciferase activity in a time- and dose-dependent manner. Thus, castrated transgenic males or in vitro system could be useful as models for the detection of polycyclic aromatic hydrocarbons (PAHs) or environmental toxicants by measuring either hCYP1B1 or mCYP1B1 expressions.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ke Zhang ◽  
Zhuoying Li ◽  
Yunyang Lu ◽  
Linyi Xiang ◽  
Jiadong Sun ◽  
...  

Abstract Background The Wnt planar cell polarity (PCP) pathway is implicated in osteoarthritis (OA) both in animals and in humans. Van Gogh-like 2 (Vangl2) is a key PCP protein that is required for the orientation and alignment of chondrocytes in the growth plate. However, its functional roles in OA still remain undefined. Here, we explored the effects of Vangl2 on OA chondrocyte in vitro and further elucidated the molecular mechanism of silencing Vangl2 in Wnt5a-overexpressing OA chondrocytes. Methods Chondrocytes were treated with IL-1β (10 ng/mL) to simulate the inflammatory microenvironment of OA. The expression levels of Vangl2, Wnt5a, MMPs, and related proinflammatory cytokines were measured by RT-qPCR. Small interfering RNA (siRNA) of Vangl2 and the plasmid targeting Wnt5a were constructed and transfected into ATDC5 cells. Then, the functional roles of silencing Vangl2 in the OA chondrocytes were investigated by Western blotting, RT-qPCR, and immunocytochemistry (ICC). Transfected OA chondrocytes were subjected to Western blotting to analyze the relationship between Vangl2 and related signaling pathways. Results IL-1β induced the production of Vangl2, Wnt5a, and MMPs in a time-dependent manner and the significantly increased expression of Vangl2. Vangl2 silencing effectively suppressed the expression of MMP3, MMP9, MMP13, and IL-6 at both gene and protein levels and upregulated the expression of type II collagen and aggrecan. Moreover, knockdown of Vangl2 inhibited the phosphorylation of MAPK signaling molecules (P38, ERK, and JNK) and P65 in Wnt5a-overexpressing OA chondrocytes. Conclusions For the first time, we demonstrate that Vangl2 is involved in the OA process. Vangl2 silencing can notably alleviate OA progression in vitro by inhibiting the expression of MMPs and increasing the formation of the cartilage matrix and can inhibit the proinflammatory effects of Wnt5a via MAPK and NF-κB pathway. This study provides new insight into the mechanism of cartilage inflammation.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chunyang Li ◽  
Shuangqing Yang ◽  
Huaqing Ma ◽  
Mengjia Ruan ◽  
Luyan Fang ◽  
...  

Abstract Background Cervical cancer is a type of the most common gynecology tumor in women of the whole world. Accumulating data have shown that icariin (ICA), a natural compound, has anti-cancer activity in different cancers, including cervical cancer. The study aimed to reveal the antitumor effects and the possible underlying mechanism of ICA in U14 tumor-bearing mice and SiHa cells. Methods The antitumor effects of ICA were investigated in vivo and in vitro. The expression of TLR4/MyD88/NF-κB and Wnt/β-catenin signaling pathways were evaluated. Results We found that ICA significantly suppressed tumor tissue growth and SiHa cells viability in a dose-dependent manner. Also, ICA enhanced the anti-tumor humoral immunity in vivo. Moreover, ICA significantly improved the composition of the microbiota in mice models. Additionally, the results clarified that ICA significantly inhibited the migration, invasion capacity, and expression levels of TGF-β1, TNF-α, IL-6, IL-17A, IL-10 in SiHa cells. Meanwhile, ICA was revealed to promote the apoptosis of cervical cancer cells by down-regulating Ki67, survivin, Bcl-2, c-Myc, and up-regulating P16, P53, Bax levels in vivo and in vitro. For the part of mechanism exploration, we showed that ICA inhibits the inflammation, proliferation, migration, and invasion, as well as promotes apoptosis and immunity in cervical cancer through impairment of TLR4/MyD88/NF-κB and Wnt/β-catenin pathways. Conclusions Taken together, ICA could be a potential supplementary agent for cervical cancer treatment.


2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Ying-Ying Liang ◽  
Xu-Bin Deng ◽  
Xian-Tao Lin ◽  
Li-Li Jiang ◽  
Xiao-Ting Huang ◽  
...  

Abstract Nasopharyngeal carcinoma (NPC) is a highly aggressive tumor characterized by distant metastasis. Deletion or down-regulation of the tumor suppressor protein ras-association domain family protein1 isoform A (RASSF1A) has been confirmed to be a key event in NPC progression; however, little is known about the effects or underlying mechanism of RASSF1A on the malignant phenotype. In the present study, we observed that RASSF1A expression inhibited the malignant phenotypes of NPC cells. Stable silencing of RASSF1A in NPC cell lines induced self-renewal properties and tumorigenicity in vivo/in vitro and the acquisition of an invasive phenotype in vitro. Mechanistically, RASSF1A inactivated Yes-associated Protein 1 (YAP1), a transcriptional coactivator, through actin remodeling, which further contributed to Platelet Derived Growth Factor Subunit B (PDGFB) transcription inhibition. Treatment with ectopic PDGFB partially increased the malignancy of NPC cells with transient knockdown of YAP1. Collectively, these findings suggest that RASSF1A inhibits malignant phenotypes by repressing PDGFB expression in a YAP1-dependent manner. PDGFB may serve as a potential interest of therapeutic regulators in patients with metastatic NPC.


2004 ◽  
Vol 33 (1) ◽  
pp. 11-19 ◽  
Author(s):  
RY Li ◽  
HD Song ◽  
WJ Shi ◽  
SM Hu ◽  
YS Yang ◽  
...  

In addition to serving as a fat depot, adipose tissue is also considered as an important endocrine organ that synthesizes and secretes a number of factors. Leptin is an adipocyte-derived hormone that plays a vital role in energy balance. Expression of leptin is regulated by dietary status and hormones. In the present study, we report that galanin, an orexigenic peptide, inhibits leptin expression and secretion in rat adipose tissue and in 3T3-L1 adipocytes. Treatment with galanin (25 micro g/animal) induced approximately 46% down-regulation of leptin secretion at 15 min, followed by 40, 37 and 47% decreases in leptin secretion at 1, 2 and 4 h respectively. Although Northern blot analysis of adipose tissue from the same animals showed that leptin mRNA expression in adipose tissue was unaffected by galanin treatment for 2 h, galanin treatment for 4 h led to decline of leptin mRNA expression in a dose-dependent manner. Meanwhile, treating the rats with galanin had no effect on leptin mRNA expression in the hypothalamus. The inhibitory action of the galanin on leptin mRNA and protein levels was also observed in vitro. When incubated with 10 nM galanin for 48 h, leptin mRNA expression and protein secretion also decreased in 3T3-L1 adipocytes. On the other hand, galanin was found not only to express in rat adipose tissue, but also to increase about 8-fold after fasting. Based on these data, we speculate that increased galanin expression in rat adipose tissue after fasting may be involved in reducing leptin expression and secretion in fasting rats.


Blood ◽  
2021 ◽  
Author(s):  
Alexandra Sipol ◽  
Erik Hameister ◽  
Busheng Xue ◽  
Julia Hofstetter ◽  
Maxim Barenboim ◽  
...  

Cancer cells are in most instances characterized by rapid proliferation and uncontrolled cell division. Hence, they must adapt to proliferation-induced metabolic stress through intrinsic or acquired anti-metabolic stress responses to maintain homeostasis and survival. One mechanism to achieve this is to reprogram gene expression in a metabolism-dependent manner. MondoA (also known as MLXIP), a member of the MYC interactome, has been described as an example of such a metabolic sensor. However, the role of MondoA in malignancy is not fully understood and the underlying mechanism in metabolic responses remains elusive. By assessing patient data sets we found that MondoA overexpression is associated with a worse survival in pediatric common acute lymphoblastic leukemia (B-ALL). Using CRISPR/Cas9 and RNA interference approaches, we observed that MondoA depletion reduces transformational capacity of B-ALL cells in vitro and dramatically inhibits malignant potential in an in vivo mouse model. Interestingly, reduced expression of MondoA in patient data sets correlated with enrichment in metabolic pathways. The loss of MondoA correlated with increased tricarboxylic acid (TCA) cycle activity. Mechanistically, MondoA senses metabolic stress in B-ALL cells by restricting oxidative phosphorylation through reduced PDH activity. Glutamine starvation conditions greatly enhance this effect and highlight the inability to mitigate metabolic stress upon loss of MondoA in B-ALL. Our findings give a novel insight into the function of MondoA in pediatric B-ALL and support the notion that MondoA inhibition in this entity offers a therapeutic opportunity and should be further explored.


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