Apoptosis-associated Proteins Caspase-3 Research Articles

Sanguinarine Attenuates Lung Cancer Progression via Oxidative Stress-induced Cell Apoptosis.

Lung cancer (LC) incidence is rising globally and is reflected as a leading cause of cancer-associated deaths. Lung cancer leads to multistage carcinogenesis with gradually increasing genetic and epigenetic changes. Sanguinarine (sang) mediated the anticancer effect in LCC lines by involving the stimulation of reactive oxygen species (ROS), impeding Bcl2, and enhancing Bax and other apoptosis-associated protein Caspase-3, -9, and -PARP, subsequently inhibiting the LC invasion and migration. This study was conducted to investigate the apoptotic rate and mechanism of Sang in human LC cells (LCC) H522 and H1299. MTT assay to determine the IC50, cell morphology, and colony formation assay were carried out to show the sanguinarine effect on the LC cell line. Moreover, scratch assay and transwell assay were performed to check the migration. Western blotting and qPCR were done to show its effects on targeted proteins and genes. ELISA was performed to show the VEGF effect after Sanguinarine treatment. Immunofluorescence was done to check the interlocution of the targeted protein. Sang significantly inhibited the growth of LCC lines in both time- and dose-dependent fashions. Flow cytometry examination and Annexin-V labeling determined that Sang increased the apoptotic cell percentage. H522 and H1299 LCC lines treated with Sang showed distinctive characteristics of apoptosis, including morphological changes and DNA fragmentation. Sang exhibited anticancer potential in LCC lines and could induce apoptosis and impede the invasion and migration of LCC, emerging as a promising anticancer natural agent in lung cancer management.

Licochalcone B, a Natural Autophagic Agent for Alleviating Oxidative Stress-Induced Cell Death in Neuronal Cells and Caenorhabditis elegans Models.

Autophagy has been implicated in the regulation of neuroinflammation and neurodegenerative disorders. Licochalcone B (LCB), a chalcone from Glycyrrhiza inflata, has been reported to have anti-cancer, anti-oxidation and anti-β–amyloid fibrillation effects; however, its effect in autophagy remain un-investigated. In the current study, the potential neuro-protective role of LCB in terms of its anti-oxidative, anti-apoptotic, and autophagic properties upon oxidative stress-induced damage in neuronal cells was investigated. With the production of reactive oxygen species (ROS) as a hallmark of neuroinflammation and neurodegeneration, hydrogen peroxide (H2O2) was adopted to stimulate ROS-induced cell apoptosis in PC-12 cells. Our findings revealed that LCB reduced cell cytotoxicity and apoptosis of PC-12 cells upon H2O2-stimulation. Furthermore, LCB increased the level of the apoptosis-associated proteins caspase-3 and cleaved caspase-3 in H2O2-induced cells. LCB effectively attenuated the level of oxidative stress markers such as MDA, SOD, and ROS in H2O2-induced cells. Most importantly, LCB was confirmed to possess its anti-apoptotic effects in H2O2-induced cells through the induction of ATG7-dependent autophagy and the SIRT1/AMPK signaling pathway. As a novel autophagic inducer, LCB increased the level of autophagy-related proteins LC3–II and decreased p62 in both neuronal cells and Caenorhabditis elegans (C. elegans) models. These results suggested that LCB has potential neuroprotective effects on oxidative damage models via multiple protective pharmacological mechanisms.

The regulation of dermal mesenchymal stem cells on keratinocytes apoptosis.

Dermal mesenchymal stem cells (DMSCs) are progenitor cells with the capacity of self-renewal, multilineage differentiation, and immunomodulation, which were reported to induce the proliferation of keratinocytes, however the regulation on keratinocytes apoptosis was unknown. In this study, we isolated DMSCs from normal skin and co-cultured with keratinocytes, and then detected apoptosis of keratinocytes by flow cytometry and expression of apoptosis associated proteins by western blot. The mRNA expression profile of normal DMSCs was investigated by RNA sequencing. The results of our study presented that the DMSCs promoted HaCaT cells apoptosis both in early apoptotic state (13.8 vs. 2.9, p < 0.05) and late apoptotic state (4.2 vs. 0.7, p < 0.05). The expression of apoptosis associated proteins caspase-3 (3.51 vs. 1.99, p < 0.05) and lymphoid enhancer-binding factor 1 (3.10 vs. 0.83, p < 0.05) were upregulated. However, the cell cycle protein cyclin E1 was similar (9.38 vs. 9.05, p > 0.05). Moreover, 33 genes with the function of induced cell apoptosis were highly expressed in DMSCs, including insulin-like growth factor-binding protein 4 (2828.13), IGFBP7 (1805.69), cathepsin D (1694.34), cathepsin B (CTSB, 1641.40) and dickkopf WNT signaling pathway inhibitor 1 (DKK1, 384.79). This study suggested DMSCs induce the apoptosis of keratinocytes through non-G1/S phase blockade via highly expression of apoptosis inducer.

Metformin reduces pancreatic cancer cell proliferation and increases apoptosis through MTOR signaling pathway and its dose-effect relationship.

To study the influences of metformin on the proliferation and apoptosis of pancreatic cancer cells and its dose-effect relationship and crucial molecular mechanism. With human pancreatic cancer cell line PANC-1 as the study object, different concentrations of metformin were added for intervention. Then, the proliferation of PANC-1 cells was detected via methyl thiazolyl tetrazolium (MTT) assay to determine the dose-effect relationship of metformin in PANC-1 cell proliferation. PANC-1 cells were treated with metformin at three appropriate concentrations as Metformin treatment groups, and an equal amount of dimethyl sulfoxide (DMSO) was added in Control group. Flow cytometry was performed to detect PANC-1 cell cycle and apoptosis, and the apoptosis of PANC-1 cells was also evaluated via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Caspase-3 protein localization and expression in PANC-1 cells were detected using immunofluorescence assay. Besides, the expressions of the apoptosis-associated proteins Caspase-3, B-cell lymphoma 2 (Bcl-2), and Bcl-2 associated X protein (Bax) and phosphatidylinositol 3-hydroxy kinase (PI3K), phosphorylated protein kinase B (p-Akt), and p-mammalian target of rapamycin (mTOR) proteins related to the mTOR pathway were detected using Western blotting. Metformin repressed the proliferation of human pancreatic cancer PANC-1 cells in a concentration-dependent and time-dependent manner. Compared with Control group, Metformin treatment groups (0, 20 and 40 mM) exhibited a higher proportion of PANC-1 cells in G0/G1 phases, and a lower proportion of PANC-1 cells in S phase (p<0.05), and the change in the proportion of cells in G2/M phase was not statistically significant (p>0.05). Moreover, Metformin treatment groups (0, 20, and 40 mM) had more apoptotic PANC-1 cells, higher expression levels of pro-apoptosis proteins Caspase-3 and Bax and lower expression levels of anti-apoptosis protein Bcl-2 and the mTOR pathway-related proteins PI3K, p-Akt, and p-mTOR in cells than Control group (p<0.05). Metformin modulates the mTOR signaling pathway to reduce the proliferation of pancreatic cancer cell, but increase their apoptosis.

Preliminary study of antimicrobial peptide cathelicidin-PY therapy in mice with acute liver failure

Objective: To investigate the feasibility of cationic antimicrobial peptide cathelicidin-PY(PY) therapy through a mouse model of acute liver failure. Methods: The ability of different concentrations of antimicrobial peptide PY to neutralize endotoxin / lipopolysaccharide (LPS) in vitro was detected by Limulus Amebocyte Lysate (LAL) assay. Cell counting kit-8 (CCK-8) was used to detect the toxic effect of different concentrations of antimicrobial peptide PY on mouse monocyte macrophages (RAW264.7). An in vitro hemolysis experiment was used to evaluate the activity of antimicrobial peptide PY on healthy human erythrocytes. D-galactosamine combined with LPS- induced mouse model of acute liver failure was constructed. The antimicrobial peptide PY effect on survival rate of mouse model was observed. HE staining was used to observe the pathological changes of liver tissue. Immunohistochemistry and Western blotting were used to detect the expression of apoptosis-associated protein caspase-3. Intra-group comparisons were performed using t-test and analysis of variance. χ (2) test was used for the comparison of rates. Results: An in vitro experiment showed that the endotoxin neutralization rate was higher at very low dose (0.01 μmol/L), and exceeded 70% at medium-dose (10-40 μmol/L), and the difference between groups with different concentration was statistically significant (F = 569.22, P < 0.05). Medium-dose antimicrobial peptide PY had strong endotoxin neutralizing effect, low cytotoxicity and hemolytic activity. Moreover, in vivo experiments showed that the degree of liver injury and survival rate of mouse model was significantly improved with the medium-dose of antimicrobial peptide PY. Immunohistochemistry results showed that the expression of caspase-3 in the liver tissue was significantly depleted in the medium-dose group than that of the liver failure group, and the results were consistent with protein immunoblotting testing. Conclusion: Antimicrobial peptide PY possesses a strong ability to neutralize endotoxin and few toxic side effects. A specific dose of antimicrobial peptide PY can attenuate hepatocyte apoptosis and significantly improve the survival rate of animal model, and thus provides a new idea for the liver failure treatment.

MiR-328 inhibits cell apoptosis and improves cardiac function in rats with myocardial ischemia-reperfusion injury through MEK-ERK signaling pathway.

To explore the influences of micro ribonucleic acid (miR)-328 on rats with myocardial ischemia-reperfusion (IR) injury through the methyl ethyl ketone (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway. A total of 36 Sprague-Dawley rats were randomly assigned into the sham group (n=12), model group (n=12), and miR-328 group (n=12). The model of myocardial IR injury was established by ligating the left anterior descending coronary artery, without any intervention in the model group, while 200 μL of miR-328 antagomir was intravenously injected before modeling in the miR-328 group. The activity of the serum myocardial enzymes lactate dehydrogenase (LDH) and creatine kinase-muscle/brain (CK-MB) was determined via ELISA to assess the cardiac function in the three groups of rats, and the mRNA expression level of miR-328 in myocardial tissues was measured through real-time fluorescence qRT-PCR in the sham group, model group, and miR-328 group. TUNEL staining was performed to detect apoptotic cells, and the levels of myocardial apoptosis-associated protein Caspase-3 and phosphorylated MEK1/2 (p-MEK1/2) and p-ERK1/2 proteins were determined using Western blotting. Compared with the sham group, the model group exhibited increased activity of LDH and CK-MB, miR-328 expression level, apoptotic cells, the relative expression level of Caspase-3, and protein levels of p-MEK and p-ERK, with statistically significant differences (p<0.05). Besides, in comparison with the model group, miR-328 group showed a decreased activity of LDH and CK-MB, miR-328 expression level, the relative expression level of Caspase-3, and protein levels of p-MEK and p-ERK, displaying statistically significant differences (p<0.05). MiR-328 modulates the MEK-ERK signaling pathway to inhibit cell apoptosis and improve the cardiac function in rats with myocardial IR injury.

CCL2 influences the sensitivity of lung cancer A549 cells to docetaxel.

Lung cancer is one of the most common malignant tumor types globally. Acquisition of chemoresistance in lung cancer cells is the primary cause of chemotherapy failure. Inflammatory chemokine C-C motif chemokine ligand 2 (CCL2) has been reported to be involved in the progression of cancer and drug resistance. However, its function in docetaxel (DTX) resistance of lung cancer remains unclear. In the present study, the mechanism underlying DTX-induced drug resistance was investigated. Reverse transcription-quantitative polymerase chain reaction and western blot analysis revealed that DTX treatment increased the mRNA and protein expression of CCL2 in lung cancer A549 cells. CCL2 was knocked down by small interfering RNA or was overexpressed by recombinant CCL2 lentivirus, and cell viability was determined. An MTT assay indicated that CCL2 downregulation decreased the viability of A549 cells and augmented the DTX-induced cytotoxicity, whereas CCL2 upregulation protected A549 cells from DTX-induced cytotoxicity. Additionally, it was revealed that CCL2 overexpression activated phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling and inhibited apoptosis-associated protein caspase-3 activation and B-cell lymphoma 2 (Bcl-2) phosphorylation at Ser70 induced by DTX, and enhanced DTX-induced Bcl-2-associated death promoter phosphorylation at Ser112. PI3K/AKT inhibitor LY294002 restored DTX-induced caspase-3 activation and Bcl-2 phosphorylation, reversed the effect of CCL2 on the viability of A549 cells and enhanced DTX-induced cytotoxicity. These results demonstrated that chemoresistance may be mediated by cell stress responses involving CCL2 expression, suggesting that CCL2 may be a potential target for enhancing the therapeutic effect of DTX in lung cancer.

The neuroprotective effect of apelin-13 in a mouse model of intracerebral hemorrhage

Adipocytokine apelin-13 is a peptide which could reportedly protect the brain against ischemic reperfusion injury and traumatic brain injury (TBI). Whether apelin-13 has any roles to play in intracerebral hemorrhage (ICH) has not been clarified. We aimed to investigate the roles of apelin-13 in ICH and effects on ICH-induced apoptosis. Firstly, CD-1 mice were subjected to infusion of Type IV collagenase (to induce ICH) or saline (for shams) into the left striatum. ICH animals received intracerebroventricular administration of vehicle, apelin-13 (50μg dissolved in 5μl saline) immediately after ICH. The motor function and the cerebral water content (CWC) as well as blood brain barrier (BBB) disruption were measured, coupled with determination of ICH-induced neural cell death by Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL). The apoptosis-associated proteins caspase-3 and Bcl-2 as well as the brain edema-associated proteins aquaporin-4 (AQP4) and MMP-9 were all assessed with western blotting. The results showed that apelin-13 decreased CWC and reduced Evans blue leakage into injured hemispheres, with the motor function significantly improved. Additionally, apelin-13 also acutely decreased the number of ICH-induced TUNEL-positive (TUNEL+) cells at 48h after ICH. The expressions of AQP4, MMP-9, caspse-3 and Bcl-2 were all downregulated by apelin-13 at 24h and 48h after ICH. All these results revealed that apelin-13 attenuated brain edema and reduced cellular death by suppressing apoptosis after ICH in mice.

Effect of temozolomide on the viability of musculoskeletal sarcoma cells

Musculoskeletal sarcomas (MSS) are a heterogeneous group of malignancies with relatively high mortality rates. The prognosis for patients with MSS is poor, with few drugs inducing measurable activity. Alkylating agents, namely ifosfamide and dacarbazine, which act nonspecifically on proliferating cells, are the typical therapy prescribed for advanced MSS. A novel alkylating agent, temozolomide (TMZ), has several advantages over existing alkylating agents. TMZ induces the formation of O6-methylguanine in DNA, thereby inducing mismatches during DNA replication and the subsequent activation of apoptotic pathways. However, due to conflicting data in the literature, the mechanism of TMZ action has remained elusive. Therefore, the present study aimed to evaluate apoptosis in MSS cells treated with TMZ, and to evaluate the correlation between TMZ action and survival pathways, including the phosphoinositide 3-kinase (PI3K)/Akt and extracellular signal-regulated kinase (ERK)1/2 mitogen activated protein kinase (MAPK) pathways. Cell proliferation was evaluated by performing an XTT (sodium 3'-[1-(phenylaminocarbonyl)-3,4-tetrazolium]-bis (4-methoxy-6-nitro) benzene sulfonic acid hydrate) assay. Apoptotic morphological changes, for example chromatin condensation, were evaluated by fluorescence confocal microscopy. The expression of the apoptosis-associated proteins caspase-3, poly adenosine diphosphate ribose polymerase (PARP), Akt and ERK1/2, was determined by western blotting. The results of the present study indicated that, in certain MSS cells, the IC50 value was lower than that in TMZ-sensitive U-87 MG cells. Furthermore, TMZ treatment was associated with apoptotic morphological changes and the expression levels of pro-apoptotic cleaved caspase-3 and PARP were also increased in TMZ-treated MSS cells. In addition, the results indicated that PI3K/Akt and ERK1/2 MAPK were constitutively phosphorylated in MSS cells, and phosphorylation of PI3K/Akt was suppressed in certain cells, and maintained in other cells, by TMZ. These observations emphasized the plasticity of MSS cells, and suggested that this plasticity may contribute to the variance in cell sensitivity to TMZ and TMZ-resistance in MSS.