The Role of YAP-JNK in the Mitophagy, Migration, and Invasion of Gastric Cancer.

OBJECTIVE: To determine the function of the YAP-JNK-mitophagy signalling pathway in gastric cancer (GC). STUDY DESIGN: An observational study. PLACE AND DURATION OF STUDY: Seventh People's Hospital of Shanghai University of TCM (Traditional Chinese Medicine), between June 2019 and June 2021. METHODOLOGY: Tissues from 30 cases of gastric cancer and corresponding adjacent tissues were collected. RT-qPCR was employed to detect the expression of YAP and JNK in GC samples. MTT, Wound healing and Transwell assays were used to detect changes in GC cell proliferation, migration, and invasion under different stimulation. LC3 immunofluorescence and mitochondrial membrane potential detection were used to analyse the occurrence of mitochondrial autophagy. RESULTS: The expression of YAP and JNK were significantly increased in GC tissues (p=0.024, 0.033). YAP knockdown inhibited GC cell proliferation, migration, and invasion. Further studies showed that YAP affects GC cell function by targeting JNK. In addition, YAP-JNK signalling was found to regulate GC cell proliferation, migration, and invasion mainly through regulating the occurrence of mitophagy. CONCLUSION: These findings revealed that YAP-JNK promotes the development of GC by targeting mitophagy. KEY WORDS: Gastric cancer, YAP, JNK, Autophagy.

Corrigendum to "ALDH2 Overexpression Alleviates High Glucose-Induced Cardiotoxicity by Inhibiting NLRP3 Inflammasome Activation".

[This corrects the article DOI: 10.1155/2019/4857921.].

ALDH2 Overexpression Alleviates High Glucose-Induced Cardiotoxicity by Inhibiting NLRP3 Inflammasome Activation.

Although the underlying mechanisms of diabetes-induced myocardial injury have not been fully illuminated, the inflammation reaction has been reported intently linked with diabetes. The nucleotide binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome, the key component of pyroptosis, is involved in inflammation reaction, which may be one of the important mechanisms in diabetes-induced myocardial injury. The purpose of this study was to investigate the changes of NLRP3 inflammasome and pyroptosis in high glucose-induced H9C2 cardiac cell injury and investigate whether overexpression of mitochondrial aldehyde dehydrogenase 2 (ALDH2) can reduce the occurrence of pyroptosis. The H9C2 cardiac cells were exposed to 35 mM glucose for 24 h to induce cytotoxicity. Mitochondrial ALDH2 overexpression cardiac cell line was constructed. The results showed in high glucose condition that ALDH2 overexpression significantly increased H9C2 cardiac cell viability, increased mitochondrial ALDH2 activity and protein expression, and reduced mitochondrial reactive oxygen species (ROS) production, 4-hydroxynonenal (4-HNE), and lactate dehydrogenase (LDH) levels; meanwhile, the pyroptosis key components-NLRP3 inflammasome-related proteins, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cysteine-containing aspartate specific protease 1 (Caspase-1), and interleukin-18 (IL-18) protein expressions-were significantly decreased, and IL-18 and interleukin-1ß (IL-1ß) levels were also decreased. In high glucose-induced cardiac cell injury, ALDH2 overexpression may reduce ROS production, thereby inhibiting the activation of NLRP3 inflammation and cell pyroptosis. ALDH2 gene might play the potential role in the treatment of high glucose-induced H9C2 cardiac cell injury.

[Effects of activation of mitochondrial aldehyde dehydrogenase 2 on inflammasome production in high glucose induced A549 cells].

OBJECTIVE: To investigate the effects of activation of mitochondrial aldehyde dehydrogenase 2(ALDH2) on high glucose-induced inflammasome production in alveolar epithelial A549 cells. METHODS: The alveolar epithelial A549 cells were cultured with 25 mmol/L high glucose complete medium and divided into 4 groups: Control group, ALDH2 agonist 20 µmol/L Alda-1 group, ALDH2 antagonist 60 µmol/L Daidzin group, 20 µmol/L Alda-1 + 60 µmol/L Daidzin group. After the cells treated for 24 h, the cell proliferation activity was measured by thiazolyl blue tetrazolium bromide(MTT) colorimetric assaymethod, and the cellular reactive oxygen species(ROS) level were detected by dihydroethidium(DHE) fluorescent staining method, the cell migration ability was performed by cell scratching experiments, the protein expressions of ALDH2 and the core components of inflammasome, nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3), apoptosis-associated speck-like protein containing CARD(ASC) and cysteinyl aspartate specific protease-1(caspase-1) were detected by western blot. RESULTS: Compared with the control group, after Alda-1 activated ALDH2 specifically, the cell proliferation activity did not change significantly, but the oxidative stress level and cell migration rate were significantly decreased(P<0.05). ALDH2 protein expression was significantly increased(P<0.05), the protein expressions of NLRP3, ASC and caspase-1 were significantly decreased(P<0.05). After Daidzin blocked ALDH2 specifically, there were no significant changes in cell proliferation, oxidative stress, cell migration rate, ALDH2 and ASC protein expressions, while NLRP3 protein expression was significantly increased(P<0.05), and caspase-1 protein expression was significantly decreased(P<0.05). Compared with Alda-1 group, there was no significant changes in cell proliferation and oxidative stress in Alda-1+Daidzin group, cell migration rate was significantly increased(P<0.05), ALDH2 protein expression was decreased(P<0.05), and the protein expressions of NLRP3, ASC and caspase-1 were significantly increased(P<0.05). CONCLUSION: Increasing ALDH2 expression in alveolar epithelial A549 cells may attenuate high glucose-induced cellular inflammatory reaction, possibly through reducing cellular ROS level and reducing inflammasome expression.

[Activation of aldehyde dehydrogenase 2 alleviates H 2O 2-induced injury in cardiomyocytes].

OBJECTIVE: To investigate the changes of aldehyde dehydrogenase 2 (ALDH2) expression in H 2O 2inducedcardiomyocytes oxidative stress injury. METHODS: Cultured H9C2 cardiomyocytes were exposed to H 2O 2-inducedoxidative stress and the effects of the ALDH2 agonist Alda-1 and ALDH2 inhibitor Daidzin were tested on the stress level ofthe exposed cells. MTT colorimetric assay was used to assess the cell viability after the treatments. The oxidative stress level inthe myocardial cells was detected using DHE fluorescence staining, and the activity and protein level of ALDH2 were detectedwith spectrophotometry and Western blotting. RESULTS: Compared with normal control cells, Alda-1 treatment did notsignificantly affect the cell viability, oxidative stress level, or ALDH2 activity and protein level. H 2O 2 exposure significantlylowered the cell activity and ALDH2 activity and protein expression and increased the oxidative stress level; Alda-1 treatmentobvious antagonized the effects of H 2O 2. Blocking ALDH2 with Daidzin produced similar effects to H 2O 2 exposure on theviability, oxidative stress level, and ALDH2 activity and expression in the myocardial cells. CONCLUSIONS: H 2O 2 exposure lowersthe activity and reduces the protein expression of ALDH2 in cardiomyocyte H9C2 cells, and activation of ALDH2 can alleviateH 2O 2-induced oxidative stress in the cells.

Alterations in necroptosis during ALDH2­mediated protection against high glucose­induced H9c2 cardiac cell injury.

The aim of the present study was to investigate whether necroptosis occurs in high glucose (HG)-induced H9c2 cardiac cell injury and whether the activation of aldehyde dehydrogenase 2 (ALDH2) can inhibit necroptosis. H9c2 cardiac cells were treated with 35 mM glucose to establish a HG­induced cell injury model. Alda­1 (20 µM), a specific activator of ALDH2 and necrostatin­1 (Nec­1, 100 µM), an inhibitor of necroptosis were used to treat H9c2 cardiac cells under HG conditions. Cell viability was measured using a Cell Counting Kit­8 assay and reactive oxygen species (ROS) generation was measured by the dihydroethidium staining method. ALDH2 activity was measured at 450 nm. The mRNA and protein expression of ALDH2, necroptosis­associated genes, receptor­interacting protein (RIP)1, RIP3 and mixed lineage kinase domain like pseudokinase (MLKL), were analyzed by reverse transcription­quantitative polymerase chain reaction and western blotting. The expression of cleaved caspase­3 protein was also examined by western blotting. The results demonstrated that under HG conditions, cell viability, ALDH2 activity, mRNA and protein expression were decreased. Furthermore, ROS generation, mRNA and protein expression of RIP1, RIP3, MLKL and the protein expression of cleaved caspase­3 were increased. Treatment with Alda­1 or Nec­1 attenuated HG­induced downregulation of ALDH2 activity, mRNA and protein expression. In addition, RIP1, RIP3, MLKL mRNA, and protein expression were downregulated. Furthermore, Alda­1 but not Nec­1 decreased cleaved caspase­3 protein expression. Collectively these data indicated that activation of ALDH2 protected H9c2 cardiac cells against HG­induced injury, partly by inhibiting the occurrence of necroptosis.

[Fasudil attenuates mitochondrial injury and apoptosis in rat model of myocardial ischemia/reperfusion injury].

Objective To observe the changes of mitochondria fusion protein 2 (Mfn2) and dynamin-related protein 1 (Drp1) in the cardioprotection of fasudil, and analyze the significance. Methods Hearts isolated from male Sprague-Dawley rats were subjected to ischemia for 30 minutes (occlusion of left anterior descending artery), and continuously perfusion for 120 minutes to establish myocardial ischemia/reperfusion (I/R) injury model. The rats were divided into 3 groups: sham group, I/R group and fasudil group. The left ventricular hemodynamics were continuously recorded; lactate dehydrogenase (LDH) content was measured during reperfusion; myocardial ultrastructure was observed by electron microscopy; the protein expression of phosphorylated protein phosphatase 1 regulatory subunit 12A (p-PPP1R12A/p-MYPT1) was detected by immunohistochemistry; and the protein expressions of Mfn2, Drp1 and cleaved caspase-3 (c-caspase-3) were detected by Western blot analysis. Results Compared with the sham group, the left ventricular systolic and diastolic function was weakened, and LDH release was promoted in the other two groups during reperfusion. Compared with the I/R group, fasudil improved left ventricular systolic and diastolic function and reduced LDH release. Electron microscopy and immunohistochemical results showed that myofibril and mitochondria were damaged obviously, and p-MYPT1 protein expression was enhanced in the I/R group. Compared with the I/R group, fasudil attenuated the damage of myofibril and mitochondria, and decreased p-MYPT1 protein expression. Western blotting showed that, compared with the sham group, Mfn2 protein expression decreased, Drp1 and c-caspase-3 protein expressions increased in the I/R group. Compared with I/R group, there was no obvious change in Mfn2 protein expression, while Drp1 and c-caspase 3 protein expressions decreased in the fasudil group. Conclusion Fasudil can protect against myocardial I/R damage through inhibiting Rho kinase, which has no clear correlation with Mfn2 protein expression, but may be related with decreasing Drp1 protein expression and reducing mitochondrial injury, thereby inhibiting apoptosis.