Iron-Overload Induces Apoptosis in Cardiomyocytes and Hepatocytes Via Mitochondrial/Caspase-3 Pathways.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1872-1872
Author(s):  
Mo Yang ◽  
Shing Chan ◽  
Yiu Fai Cheung ◽  
Shau Yin Ha ◽  
Godfrey ChiFung Chan
Keyword(s):  
Iron Overload ◽  
Protective Effect ◽  
Cell Viability ◽  
Caspase 3 ◽  
Annexin V ◽  
Apoptotic Cells ◽  
H9c2 Cells ◽  
Plot Analysis ◽  
Iron Treatment ◽  
Induced Apoptosis

Abstract Cardiomyopathy and liver damage due to iron-overload are the major complications in patients with beta-thalassaemia major. Iron-overload may induce apoptosis in cardiomyocytes and hepatic cells, and that TPO may exert protective effect on apoptosis of cardiomyocytes (Circulation, 2006). In this study, we demonstrated firstly that iron induced apoptosis in cardiomyocytes. Using H9C2 cells, we have shown that iron reduced cell viability in a dose-dependent manner (0.003–3 mM) (n=6). By annexin V and PI staining, apoptotic cells were found to be significantly increased after iron treatment (0.3 mM, 72 hrs) (n=6). The expression of active caspase-3 was significantly increased in iron-treated cells. Furthermore, iron treatment increased the proportion of cells containing JC-1 monomers, indicating a trend in the drop of mitochondrial membrane potential (n=6). Secondly, we found that TPO exerted cardio-protective effect on iron-induced apoptosis. H9C2 cells were cultured in the presence of iron (0.3 mM) with or without TPO (5, 10, 20, 50, 100 ng/mL, 72 hrs). The cell viability was significantly increased with the treatment of TPO at 50 ng/mL and 100 ng/mL (n=4). Dot-plot analysis of annexin V/PI staining demonstrated that TPO (50 ng/mL) significantly reduced the population of apoptotic cells (n=6). Incubation with TPO also decreased the iron-induced caspase-3 expression (n=6). Flow cytometric dot-plot analysis of H9C2 cells also showed trends of amelioration of the increase in JC-1 monomers in the iron plus TPO group (n=6). The population of phospho-Akt and Erk1/2 were also significantly increased after treatment by TPO (P<0.05, n=4). Human liver cell line MIHA was also used as a cell model. We showed that iron-overload reduced cell viability in a dose-dependent manner (0.0375–0.6 mM) (n=7). By annexin V and PI staining, apoptotic cells were found to be significantly increased after iron treatment (0.15–0.6 mM) for 72 hrs (n=7). The expression of active caspase-3 was also significantly increased in iron-treated cells (n=5). We also found that TPO exerted proliferation effect on MIHA cell by activation of phospho-Akt. However, MIHA cells were cultured in the presence of iron (0.3 mM) with TPO (50 ng/mL, 72 hrs). The cell viability was not significantly increased with the treatment of TPO (n=5). Dot-plot analysis of annexin V/PI staining did not demonstrated that TPO reduced the population of apoptotic cells induced by iron-overload (n=5). Also, incubation with TPO did not decrease the iron-induced caspase-3 expression in these cells (n=5). Our findings suggest that iron-overload induces apoptosis in cardiomyocytes and hepatocytes via mitochondrial/caspase-3 pathways and that TPO might exert a protective effect on iron-overload induced apoptosis via the activation of Akt and Erk1/2 pathways in cardiomyocytes.

TPO exerts a protective effect on iron-overload induces apoptosis in cardiomyocytes via mitochondrial pathways

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4668-4668 ◽  
Author(s):  
Mo Yang ◽  
Shing Chan ◽  
Jie yu Ye ◽  
Godfrey ChiFung Chan
Keyword(s):  
Oxidative Stress ◽  
Iron Overload ◽  
Protective Effect ◽  
Mitochondrial Membrane ◽  
Caspase 3 ◽  
Ros Production ◽  
H9c2 Cells ◽  
Plot Analysis ◽  
Iron Treatment ◽  
Induced Apoptosis

Thalassaemia companied with iron-overload is common in Hong Kong. Iron overload induced cardiomyopathy is the commonest cause of morbidity and mortality in b-thalassaemia patients. One of the causes of cardiac failure is chronic iron overload of blood transfusion. Some studies showed that iron overload can cause toxic effect in heart cells. Iron-overload induced cardiomyopathy damages are the major complications in patients with beta-thalassaemia major. Iron-overload may induce apoptosis in cardiomyocytes. Our previous study showed TPO has cardiac protective effect (Li et al, Circulation, 2007). In this study, we demonstrated firstly that iron induced oxidative stress can cause apoptosis in cardiomyocytes. By using H9C2 cells, we showed that iron increased reactive oxygen species (ROS) production (n=3) and reduced cell viability in a dose-dependent manner (0-0.6 mM) (n=6). Apoptotic cells were found to be significantly increased under iron treatment (0.3 mM, 72 hrs) in the AnnexinV/PI assay (n=6). The expression of active caspase-3 significantly increased in iron-treated cells. Furthermore, iron treatment increased the proportion of cells containing JC-1 monomers, indicating a trend in the drop of mitochondrial membrane potential (n=6). Secondly, we found that TPO exerted cardio-protective effect on iron-induced apoptosis. H9C2 cells were cultured in the presence of iron (0.3 mM) with or without TPO (50 ng/mL). The ROS production was significantly decreased with the addition of TPO at 50 ng/mL (n=3). Dot-plot analysis of AnnexinV/PI staining demonstrated that TPO significantly reduced the population of apoptotic cells (n=6). Incubation with TPO also decreased the iron-induced caspase-3 expression (n=6). Flow cytometric dot-plot analysis also showed trends of amelioration of the increase in JC-1 monomers in the iron plus TPO group (n=6), indicating a trend in attenuation of the drop of mitochondrial membrane potential. Our findings suggest that iron-overload lead to generation of ROS which further induces apoptosis in cardiomyocytes via mitochondrial pathways and TPO might exert a protective effect on iron-overload induced apoptosis via inhibiting oxidative stress and mitochondrial pathway in cardiomyocytes. Disclosures: No relevant conflicts of interest to declare.

TPO Exerts a Protective Effect on Iron-Induced Apoptosis Via Erk1/2 Signaling in Human Mesenchymal Stem Cells.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1871-1871
Author(s):  
Wei Zhang ◽  
Mo Yang ◽  
Shing Chan ◽  
Godfrey ChiFung Chan
Keyword(s):  
Iron Overload ◽  
Protective Effect ◽  
Calcium Channel ◽  
Calcium Channel Blocker ◽  
Channel Blocker ◽  
Annexin V ◽  
Plot Analysis ◽  
Haematopoietic Growth Factor ◽  
Iron Treatment ◽  
Induced Apoptosis

Abstract Osteoporosis is a very common problem among adolescent and adult patients with thalassaemia major (TM). The pathogenesis of osteoporosis in TM is related to several factors including iron overload. Bone is derived from osteoblasts. And osteoblasts are differentiated from mesenchymal stem cells (MSC). Therefore, iron-overload induced MSC damage may contribute to osteopenia and osteoporosis. The effect of iron-overload on MSC has not been investigated previously. We hypothesize that iron-overload may induce apoptosis in MSC by caspase-dependent pathway, and haematopoietic growth factor thrombopoietin (TPO) and calcium channel blocker amlodipine may have a protective effect on iron-induced apoptosis in these cells. We have shown that iron (FeCl3) reduced hMSCs viability in a dose-dependent manner (0–0.6 mM) (n=5). By annexin V and PI staining, apoptotic cells were found to be significantly increased after iron treatment (0.3 mM) for 72 hrs (n=4). The expression of active caspase-3 was significantly increased in iron-treated cells (0.15mM, 0.3mM) (n=5). Iron treatment also increased the proportion of cells containing JC-1 monomers, indicating a trend in the drop of mitochondrial membrane potential. TPO exerted protective effect on iron-induced apoptosis in hMSCs. Human MSCs were cultured in the presence of iron (0.3 mM) with or without TPO (50 ng/ml) for 72 hrs (n=4). The cell viability was significantly increased with the treatment of TPO. Dot-plot analysis of annexin V/PI staining demonstrated that TPO significantly reduced the population of apoptotic cells. Incubation with TPO also decreased the iron-induced caspase-3 expression. Flow cytometric dot-plot analysis of hMSCs also showed trends of amelioration of the increase in JC-1 monomers in the iron plus TPO. The population of phospho-Erk1/2 was also significantly increased in TPO-treatment, and the increased phospho-Erk was significantly reversed by the upstream signaling inhibitor PD098059. Calcium channel blocker amlodipine (10−9M) also had a protective effect on iron-induced apoptosis in these cells. Our findings suggest that iron-overload induces apoptosis in hMSCs via the caspase-dependent pathway and that TPO and amlodipine might exert a protective effect on iron-induced apoptosis via the activation of Erk1/2 signaling. The use of either haematopoietic growth factor or calcium channel blocker for the protection of hMSCs from iron induced toxicity is a novel concept. Our study has the potential in minimizing the bone damage induced by iron-overload in patients with thalassaemia major.

Angelica Polysaccharide and TPO Have a Protective Effect On Hcmv-Induced Apoptosis In Megakaryocytes

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3553-3553
Author(s):  
Mo Yang ◽  
Jian Liang Chen ◽  
Jie yu Ye ◽  
Su yi Li ◽  
En yu Liang ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Protective Effect ◽  
Caspase 3 ◽  
Hcmv Infection ◽  
Annexin V ◽  
Angelica Sinensis ◽  
Control Group ◽  
Mock Control ◽  
Apoptotic Effect ◽  
Induced Apoptosis

Abstract Human cytomegalovirus (hCMV) infection is often associated with thrombocytopenia. Megakaryocytes may be one of the major sites of hCMV infection, then inducing this cell apoptosis. Angelica Sinensis (Danggui) is an important ingredient of many commonly used herbal Medicine for promoting blood production. Our previous study has showed that the hematopoietic effect of Angelica Sinensis is related to its constituent, angelica polysaccharide (APS) (Yang M et al, J Ethnopharma, 2009). This present study investigated the anti-apoptotic effect of APS and TPO on hCMV-induced apoptosis in megakaryocytes. Human bone marrow mononuclear cells (MNC) or megakaryocytic cell line CHRF-288-11 and hCMV AD169 strain were co-cultured in this study. hCMV significantly inhibited the formation of CFU-MK as shown in three different concentrations of viral infection groups (103, 104 and 105 pfu/ml), compared with blank control and mock control (n=10, P<0.05). hCMV also significantly inhibited the growth of CHRF cells in these three different concentrations after incubation for 3 days, which compared with control group (n=10, P<0.01). hCMV DNA and mRNA were also positively detected in CHRF cells and the cells of CFU-MK with IS-PCR and RT-PCR respectively, while it was negative in blank and mock control groups. We further studied the effect of APS and TPO on CFU-MK formation. Results showed that APS (50 ug/ml) like TPO (50 ng/ml) enhanced hCMV-reduced CFU-MK (P=0.05, n=6). CHRF cells were also analyzed by Annexin V/PI with flow cytometry at day 3 after infection with hCMV AD169. The percentage of apoptotic cells in group of 103 pfu/ml was 19.0 ± 2.0%; The group of 104 pfu/ml was 23.0 ± 1.5%; The group of 105 pfu/ml was 28.0 ± 3.0%. The control group was 2.0 ± 0.5%. The apoptotic cells were confirmed by morphologic observation. In addition, apoptotic signals from megakaryocytic surface, cytoplasma and mitochondria were detected in hCMV infected cells by flow cytometry with Caspase-3 and JC-1 assay. Compared to mock infection control at day 5, Annexin-V positive cells population increased by 58%; active caspase-3 signal increased by 120% in viable cell population; and cell population with damaged mitochondial membrane showed a 5-times increase. Moreover, the anti-apoptotic effect of APS and TPO on CHRF cells was also demonstrated by using Annexin-V assay. Our studies showed that hCMV induces the apoptosis in megakaryocytes via mitochondrial and caspase-3 signaling, and angelica polysaccharide (APS) like TPO has a protective effect on hCMV-induced apoptosis in these cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Sheng Mai San protects H9C2 cells against hyperglycemia-induced apoptosis

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Bing Pang ◽  
Li-Wei Shi ◽  
Li-juan Du ◽  
Yun-Chu Li ◽  
Mei-Zhen Zhang ◽  
...  
Keyword(s):  
Cell Viability ◽  
Molecular Mechanisms ◽  
Annexin V ◽  
Signalling Pathway ◽  
H9c2 Cell ◽  
Protective Effects ◽  
H9c2 Cells ◽  
P53 Expression ◽  
Fasl Gene ◽  
Induced Apoptosis

Abstract Background Sheng Mai San (SMS) has been proven to exhibit cardio-protective effects. This study aimed to explore the molecular mechanisms of SMS on hyperglycaemia (HG)-induced apoptosis in H9C2 cells. Methods HG-induced H9C2 cells were established as the experimental model, and then treated with SMS at 25, 50, and 100 μg/mL. H9C2 cell viability and apoptosis were quantified using MTT and Annexin V-FITC assays, respectively. Furthermore, Bcl-2/Bax signalling pathway protein expression and Fas and FasL gene expression levels were quantified using western blotting and RT-PCR, respectively. Results SMS treatments at 25, 50, 100 μg/mL significantly improved H9C2 cell viability and inhibited H9C2 cell apoptosis (p < 0.05). Compared to the HG group, SMS treatment at 25, 50, and 100 μg/mL significantly downregulated p53 and Bax expression and upregulated Bcl-2 expression (p < 0.05). Moreover, SMS treatment at 100 μg/mL significantly downregulated Fas and FasL expression level (p < 0.05) when compared to the HG group. Conclusion SMS protects H9C2 cells from HG-induced apoptosis probably by downregulating p53 expression and upregulating the Bcl-2/Bax ratio. It may also be associated with the inhibition of the Fas/FasL signalling pathway.

scholarly journals Protective effect of resveratrol against corticosterone-induced neurotoxicity in PC12 cells

2019 ◽  
Vol 10 (1) ◽  
pp. 235-240 ◽  
Author(s):  
Ye Zhang ◽  
Yun He ◽  
Ning Deng ◽  
Yan Chen ◽  
Jiecong Huang ◽  
...  
Keyword(s):  
Protein Expression ◽  
Protective Effect ◽  
Cell Viability ◽  
Pc12 Cells ◽  
Caspase 3 ◽  
Annexin V ◽  
Cell Counting ◽  
Depressant Effect ◽  
Protective Efficiency ◽  
Related Proteins

Abstract Objective Resveratrol(RES) is a natural polyphenol which possesses an anti-depressant effect. However, the mechanisms of its anti-depressant effect remain unclear. The aim of the study is to investigate the potential mechanisms in the neuro-protective efficiency in the corticosterone-induced pheochromacytoma 12 (PC12) cells. Methods PC12 cells were treated with 200 μM of corticosterone in the absence or presence of different concentrations of RES for 24 h. Then, cell viability was measured by Cell Counting Kit-8 assay. Apoptosis of PC12 cells was measured by Annexin V-FITC and Propidium iodide (PI) labelling. The expression of apoptosis-related proteins including Bax, Bcl-2, caspase-3 was determined by western blotting. Results The results showed that treatment with 200 μM of corticosterone induced cytotoxicity in PC12 cells. However, different concentrations of RES (2.5μmol/L, 5μmol/L and 10 μmol/L) significantly increased the cell viability, suppressed the apoptosis of PC12 cells, down-regulated Bax and caspase-3 protein expression, and up-regulated Bcl-2 protein expression, compared to the model group (p<0.05). Conclusion Resveratrol has a protective effect on corticosterone-induced neurotoxicity in PC12 cells, which may be related to the apoptosis via inhibition of apoptosis-related proteins and displays the antidepressant-like effect.

scholarly journals Mitigation of H2O2-Induced Mitochondrial-Mediated Apoptosis in NG108-15 Cells by Novel Mesuagenin C fromMesua kunstleri(King) Kosterm

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Gomathi Chan ◽  
Muhamad Noor Alfarizal Kamarudin ◽  
Daniel Zin Hua Wong ◽  
Nor Hadiani Ismail ◽  
Faizuri Abdul Latif ◽  
...  
Keyword(s):  
Cell Viability ◽  
Caspase 3 ◽  
Chromatin Condensation ◽  
Annexin V ◽  
Data Interpretation ◽  
Hexane Extract ◽  
Neuroprotective Activity ◽  
Apoptotic Pathway ◽  
Chemical Structures ◽  
Induced Apoptosis

This study was aimed to isolate and evaluate neuroprotective compounds from the hexane extract of the bark ofMesua kunstleri(Clusiaceae) on H2O2-induced apoptosis in NG108-15 cells. Five 4-phenylcoumarins were isolated by using various chromatographic techniques via neuroprotective activity-guided fractionation and isolation from the active hexane extract. The chemical structures of the isolated compounds were confirmed by NMR spectroscopic data interpretation and comparison with literature values. Cell viability data demonstrated that mesuagenin C3significantly increased cell viability. Hoechst 33342/PI staining illustrated mesuagenin C3was able to abate the nuclear shrinkage, chromatin condensation and formation of apoptotic bodies. Pretreatment with mesuagenin C3reduced total annexin V positive cells and increased the level of intracellular glutathione (GSH). Mesuagenin C3attenuated membrane potential (Δψm), reduced Bax/Bcl-2 ratio and inactivated of caspase-3/7 and -9. These results indicated that mesuagenin C3could protect NG108-15 cells against H2O2-induced apoptosis by increasing intracellular GSH level, aggrandizingΔψm, and modulating apoptotic signalling pathway through Bcl-2 family and caspase-3/7 and -9. These findings confirmed the involvement of intrinsic apoptotic pathway in H2O2-induced apoptosis and suggested that mesuagenin C3may have potential therapeutic properties for neurodegenerative diseases.

scholarly journals Thrombopoietin Protects Cardiomyocytes from Iron-Overload Induced Oxidative Stress and Mitochondrial Injury

2015 ◽  
Vol 36 (5) ◽  
pp. 2063-2071 ◽  
Author(s):  
Shing Chan ◽  
Godfrey Chifung Chan ◽  
Jieyu Ye ◽  
Qizhou Lian ◽  
Jianliang Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Membrane Potential ◽  
Iron Overload ◽  
Protective Effect ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Lipid Hydroperoxides ◽  
Ros Production ◽  
H9c2 Cells ◽  
Induced Apoptosis

Background/Aims: Thalassaemia accompanied with iron-overload is common in Hong Kong. Iron-overload induced cardiomyopathy is the commonest cause of morbidity and mortality in patients with β-thalassaemia. Chronic iron-overload due to blood transfusion can cause cardiac failure. Decreased antioxidant defence and increased ROS production may lead to oxidative stress and cell injury. Iron-overload may lead to heart tissue damage through lipid peroxidation in response to oxidative stress, and a great diversity of toxic aldehydes are formed when lipid hydroperoxides break down in heart and plasma. Methods: Iron entry into embryonic heart H9C2 cells was determined by calcein assay using a fluorometer. Reactive oxygen species (ROS) production in cells treated with FeCl3 or thrombopoietin (TPO) was monitored by using the fluorescent probe H2DCFDA. Changes in mitochondrial membrane potential of H9C2 cells were quantified by using flow cytometry. Results: We demonstrated that iron induced oxidative stress and apoptosis in cardiomyocytes, and that iron increased ROS production and reduced cell viability in a dose-dependent manner. Iron treatment increased the proportion of cells with JC-1 monomers, indicating a trend of drop in the mitochondrial membrane potential. TPO exerted a cardio-protective effect on iron-induced apoptosis. Conclusions: These findings suggest that iron-overload leads to the generation of ROS and further induces apoptosis in cardiomyocytes via mitochondrial pathways. TPO might exert a protective effect on iron-overload induced apoptosis via inhibiting oxidative stress and suppressing the mitochondrial pathways in cardiomyocytes.

scholarly journals Protective Effect of Two Alkaloids from Hippophae rhamnoides Linn. against Doxorubicin-Induced Toxicity in H9c2 Cardiomyoblasts

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1946
Author(s):  
Wenna Zhou ◽  
Jian Ouyang ◽  
Na Hu ◽  
Gang Li ◽  
Honglun Wang
Keyword(s):  
Protein Expression ◽  
Protective Effect ◽  
Caspase 3 ◽  
Cardiac Cells ◽  
Potential Candidate ◽  
H9c2 Cells ◽  
Cardiac Muscle Cells ◽  
Anti Cancer ◽  
H9c2 Cardiomyoblasts ◽  
Induced Apoptosis

Background: Doxorubicin (Dox) is one of the most frequently prescribed anti-cancer drugs. However, clinical application with Dox is limited due to its potentially fatal cumulative cardiotoxicity. N-p-coumaroyl-4-aminobutan-1-ol (alk-A), an organic amide alkaloid and hippophamide (alk-B), a rare pyridoindole alkaloid were successfully obtained by purification and separation of seabuckthorn seed residue in our previous research. This study was undertaken to investigate the protective effect of alk-A and alk-B against Dox-induced embryonic rat cardiac cells (H9c2 cells) apoptosis. Methods: H9c2 cells were treated with Dox (2.5 µM) in the presence of alk-A and alk-B (10, 20, and 40 µM) and incubated for 24 h. Results: It was shown that pretreatment of the H9c2 cells with alk-A and alk-B significantly reduced Dox-induced apoptosis. Alk-A and alk-B both inhibited reactive oxygen species (ROS) production and suppressed cleaved-caspase-3 protein expression and the activation of JNK (Jun N-terminal kinases), as well as increasing ATP levels, favoring mitochondrial mitofusin protein expression, and relieving damage to mitochondrial DNA. Conclusions: These results suggest that alk-A and alk-B can inhibit Dox-induced apoptosis in H9C2 cardiac muscle cells via inhibition of cell apoptosis and improvement of mitochondrial function, while alk-B showed more protection. Alk-B could be a potential candidate agent for protecting against cardiotoxicity in Dox-exposed patients.

Thiocyanate-Dependent Inhibition of Spontaneous and Agonist-Induced Eosinophil Apoptosis by Eosinophil Peroxidase (EPO): A Potential Physiologic Role for Endogenously Generated HOSCN in Maintaining Eosinophil Viability.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1633-1633 ◽  
Author(s):  
Shawn A. Mahmud ◽  
Jianguo Wang ◽  
Arne Slungaard
Keyword(s):  
Protective Effect ◽  
Time Course ◽  
Tissue Injury ◽  
Annexin V ◽  
Immunomagnetic Separation ◽  
Relative Increase ◽  
Apoptotic Cells ◽  
Western Blots ◽  
Induced Apoptosis

Abstract Apoptotic eosinophils (EOs), atypically, release cytotoxic specific granule proteins that promote tissue damage in eosinophilic inflammatory states such as asthma. PMN myleloperoxidase strongly promotes PMN apoptosis by generating HOCl. We tested whether EPO plays a similarly pivotal role in EO apoptosis. In vivo, bromide (Br−), nitrite (NO2−), and thiocyanate (SCN−) compete for oxidation by EPO and H2O2 yielding, respectively, HOBr, NO2°, and HOSCN. We have shown that SCN- is the strongly preferred substrate for EPO in vivo and that HOSCN, in striking contrast to HOBr, NO2° and HOCl, is a weak, sulfhydryl-specific oxidant. Because we recently showed that HOSCN is a uniquely potent oxidant activator of endothelial cell NF-kB (Blood 107:558 2006), a powerful antagonist of apoptosis, we hypothesized that endogenously generated HOSCN would inhibit EO apoptosis. Blood EOs were isolated from mildly atopic donors by immunomagnetic separation to > 95% purity. EOs were cultured in RPMI + 10% FCS without added IL-5 and assayed for cell viability by Annexin V and Propidium Iodide (PI) staining and flow cytometry. Apoptosis was confirmed using an immunoassay of cytoplasmic histone-associated DNA fragments, caspase 3 activation and morphology. In every time course examined, EOs were first annexin+/PI-, then later annexin+/PI+. Therefore data are here reported as viability normalized to a control of EOS with 1 ng/ml IL-5, the remainder being comprised of early and late apoptotic cells. EOs cultured 2 days with 1 mM SCN− were 69% viable, a 77% relative increase (n=9, p < 0.0001) over those cultured with nothing (i.e., Cl- only), 1 mM Br-, or 1 mM NO2-, all of which had the same viability (~39%). When 0.5 nM PMA was added to activate the respiratory burst, viability with SCN− after 2 days was 63%, Cl- 5%, Br- 2%, and NO2- 14%. Surprisingly, viability with PMA and SCN− was 20% higher than that with Cl- without PMA (p < 0.05), suggesting that HOSCN not only fails to promote apoptosis but instead engenders an anti-apoptotic tone. Addition of the EPO inhibitor azide (1 mM) abrogated the protective effect of SCN− with PMA. Moreover, SCN- failed to protect EPO-devoid monocytes and lymphocytes from both spontaneous and PMA-induced apoptosis. EOs activated with the physiologic agonists C5a (33 nM) and PAF (5 μM) exhibited the same protective effect of SCN− and increased viability in activated vs. unactivated EOs. EOs treated 2 hours with and without 1mM H2O2 before adding an agonist anti-Fas antibody (1 μg/ml) had viabilities ~30% higher with SCN− than with the other halides at day 1 and at day 2, late-apoptotic cells were 42% that in Cl-. BAY 11-7085 (10μM), an inhibitor of NF-kB activation, caused rapid EO apoptosis (70% at day 1) but in this setting SCN− was not protective with or without PMA activation. Unlike PMN, Western blots for IkB-alpha showed no degradation with PMA irrespective of halide. We conclude that HOSCN generated endogenously in EOs by the EPO/H2O2/ SCN− system plays a previously unsuspected role to maintain both constitutive and agonist-stimulated EO survival. HOSCN antagonizes EO apoptosis through a mechanism that may require constitutive, but not inducible, activation of NF-kB. Because serum SCN− levels vary widely (10–300 μM) and are dietarily determined, oral supplementation with this inexpensive and innocuous pseudohalide may mitigate tissue injury in eosinophilic inflammatory states by inhibiting EO apoptosis in infiltrated organs.

Lentivirus-mediated angiopoietin-2 gene silencing decreases TNF-α induced apoptosis of alveolar epithelium cells

2016 ◽  
Vol 94 (5) ◽  
pp. 491-497 ◽  
Author(s):  
Nan-Nan Sun ◽  
Chong Li ◽  
Lei Zhou ◽  
Yan Peng ◽  
Bin Zhang ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Alveolar Epithelium ◽  
Annexin V ◽  
Expression Level ◽  
Apoptotic Cells ◽  
Tnf Α ◽  
Protein Expressions ◽  
Induced Apoptosis ◽  
Angiopoietin 2 ◽  
Epithelium Cells

Objective: To investigate the role of angiopoietin-2 (Ang-2) in tumor necrosis factor-α (TNF-α) induced apoptosis of alveolar epithelium cells (AECs). Methods: TNF-α was used to induce human alveolar epithelial HPAEpiC cells, and Ang-2 siRNA vector was transfected to the HPAEpiC cells. RT–PCR and Western blot were used. TUNEL staining was applied to observe apoptosis, and annexin V–FITC–PI staining was used to calculate apoptosis rate. Results: mRNA and protein expressions of Ang-2, activated Bax, and cleaved caspase-3 in HPAEpiC cells were up-regulated, but the expression level of Bcl-2 decreased (P < 0.05). After transfection of Ang-2 siRNA, mRNA and protein expressions of Ang-2, activated Bax, and cleaved caspase-3 in HPAEpiC cells were down-regulated, but the expression level of Bcl-2 increased (P < 0.05). The number of apoptotic cells increased after TNF-α treatment; however, the number decreased after Ang-2 siRNA transfection. Annexin V–FITC–PI staining verified that the total number of apoptotic cells was elevated with TNF-α treatment, but declined after transfection of Ang-2 siRNA. Conclusions: The expression level of Ang-2 increased during TNF-α-induced apoptosis. Inhibiting Ang-2 expression may suppress the early stages of cell apoptosis and the degree of TNF-α-induced apoptosis.

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