Changes In Caspase Research Articles

Platelets express adaptor proteins of the extrinsic apoptosis pathway and can activate caspase-8.

BackgroundApoptotic pathways in platelets are important for their survival and function. Platelet apoptosis may be involved in the pathogenesis of immune thrombocytopenia (ITP), an autoimmune-mediated disease. In contrast to the intrinsic apoptosis pathway, not much is known about the extrinsic pathway mechanisms in platelets.ObjectivesTo investigate the expression of proteins involved in the extrinsic apoptosis pathway, including the death receptors, adaptor and regulator proteins in human platelets. To determine a possible trigger of the extrinsic apoptosis pathway in platelets.MethodsTo investigate the expression of key markers of the extrinsic pathway we used targeted immunofluorescence and flow cytometry assays. To study their expression and interaction we performed Western blotting and co-immunoprecipitation. Treated platelets with different apoptosis triggers were subjected to flow cytometry.ResultsWe could identify the protein expression of the pro-apoptotic proteins TRADD (Tumor Necrosis Factor Receptor type 1- Associated DEATH Domain protein), TRAF2/5, (TNF Associated Factor) and DEDAF (Death Effector Domain- Associated Factor), FADD (Fas-Associated protein with death domain) as well as the anti-apoptotic proteins DJ-1 (Deglycase 1) and c-FLIP in human platelets. ABT-737 treatment induced a disruption in the co-localization of DJ-1 with FADD. Platelets treated with ABT-737 showed an activation in caspase-3 and -8. The exposure to TNF (Tumor Necrosis Factor), FasL (Fas ligand), and TWEAK or to plasma derived from ITP patients, did not lead to changes in caspase-3 and -8 activation in platelets.ConclusionsHuman platelets express some proteins of the extrinsic apoptosis pathway which can be modulated only by ABT-737 treatment. However so far, no other apoptosis trigger or interaction with an external receptor have been yet identified.

The effect of long-term dehydration and subsequent rehydration on markers of inflammation, oxidative stress and apoptosis in the camel kidney

BackgroundDehydration has deleterious effects in many species, but camels tolerate long periods of water deprivation without serious health compromise. The kidney plays crucial role in water conservation, however, some reports point to elevated kidney function tests in dehydrated camels. In this work, we investigated the effects of dehydration and rehydration on kidney cortex and medulla with respect to pro-inflammatory markers, oxidative stress and apoptosis along with corresponding gene expression.ResultsThe cytokines IL-1β and IL-18 levels were significantly elevated in the kidney cortex of dehydrated camel, possibly expressed by tubular epithelium, podocytes and/or mesangial cells. Elevation of IL-18 persisted after rehydration. Dehydration induced oxidative stress in kidney cortex evident by significant increases in MDA and GSH, but significant decreases in SOD and CAT. In the medulla, CAT decreased significantly, but MDA, GSH and SOD levels were not affected. Rehydration abolished the oxidative stress. In parallel with the increased levels of MDA, we observed increased levels of PTGS1 mRNA, in MDA synthesis pathway. GCLC mRNA expression level, involved in GSH synthesis, was upregulated in kidney cortex by rehydration. However, both SOD1 and SOD3 mRNA levels dropped, in parallel with SOD activity, in the cortex by dehydration. There were significant increases in caspases 3 and 9, p53 and PARP1, indicating apoptosis was triggered by intrinsic pathway. Expression of BCL2l1 mRNA levels, encoding for BCL-xL, was down regulated by dehydration in cortex. CASP3 expression level increased significantly in medulla by dehydration and continued after rehydration whereas TP53 expression increased in cortex by rehydration. Changes in caspase 8 and TNF-α were negligible to instigate extrinsic apoptotic trail. Generally, apoptotic markers were extremely variable after rehydration indicating that animals did not fully recover within three days.ConclusionsDehydration causes oxidative stress in kidney cortex and apoptosis in cortex and medulla. Kidney cortex and medulla were not homogeneous in all parameters investigated indicating different response to dehydration/rehydration. Some changes in tested parameters directly correlate with alteration in steady-state mRNA levels.

LncRNA-P21 suppresses apoptosis of myocardial cells in rats with acute myocardial infarction via regulating Wnt/β-catenin signaling pathway.

The aim of this study was to investigate the expression of long non-coding ribonucleic acid (lncRNA)-p21 in rats with acute myocardial infarction (AMI) and its influences on the viability and apoptosis of myocardial cells. Sprague-Dawley rats were utilized to establish the AMI model. Myocardial tissues were extracted, and myocardial cells were isolated. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to detect the expression of lncRNA-p21. Subsequently, myocardial cells of AMI rats were cultured and transfected with lncRNA-p21 or small interfering (si)-lncRNA-p21. 48 h later, cell proliferation was determined using Cell Counting Kit-8 (CCK-8). Caspase-3 kit was applied to examine the changes in Caspase-3 after myocardial cell transfection. Moreover, Western blotting assay was performed to measure the protein expressions of apoptosis-associated indexes [B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax)] and key members of the Wnt signaling pathway (Wnt-5a and β-catenin). The expression of lncRNA-p21 decreased significantly in myocardial tissues (p<0.01). However, the mRNA expression of inflammatory factors was significantly upregulated in AMI group compared with those in Sham group (p<0.01). Compared with Vehicle group, LncRNA-p21 group exhibited remarkably enhanced myocardial cell viability (p<0.05). However, Si-lncRNA-p21 group weakened myocardial cell viability (p<0.05). The expression of Caspase-3 in myocardial cells was reduced in LncRNA-p21 group (p<0.05), but remarkably rose in Si-lncRNA-p21 group (p<0.05) in comparison with Vehicle group. In addition, the protein expressions of Wnt-5a and β-catenin in myocardial cells were significantly higher in LncRNA-p21 group (p<0.05), whereas were lower in Si-lncRNA-p21 group (p<0.05) than those in Vehicle group. LncRNA-p21 was lowly expressed in myocardial tissues of AMI rats. Furthermore, it affected the proliferation, apoptosis and inflammation level of myocardial cells in AMI rats by activating the Wnt/β-catenin signaling pathway.

Immunohistochemical Signs of Apoptosis and Neuroplasticity in the Cerebral Cortex of White Rats after Occlusion of the Common Carotid Arteries

Objective. To study the activity of apoptotic proteins (bcl-2, p53, caspase-3) and neuroplasticity proteins (p38, MAP-2) in the sensorimotor cortex (SMC) in the brains of white rats in health and at different times after 20-min occlusion of the common carotid arteries (OCCA). Materials and methods. Light microscopy (hematoxylin and eosin staining), immunohistochemistry, and morphometry methods were used. Study materials: the control group consisted of sham-operated animals (n = 5) and the study group consisted of animals 1, 3, 7, 14, and 30 days after OCCA (n = 25). Results. OCCA was followed, on the background of irreversible destruction of a proportion of SMCC neurons (layer III 25.1%, layer V 19.0%), by reorganization of processes (MAP-2) and synapses (p38) of surviving neurons. The relative contents of labeled anti-p38 and anti-caspase-3 antibodies located in synaptic terminals decreased (on days 1 and 3) and then recovered (on day 7). The most marked changes in caspase-3 during the postischemic period were noted at 7, 14, and 30 days, when its content was greater than that of p38. Conclusions. Postischemic compensatory reorganization of the neuronal communication system (processes, synapses) occurred on the background of a high axon caspase-3 level. No signs of apoptosis (activation of caspase-3 in the perikaryon) were seen. Caspase-3 should be regarded as aspect of pleiotropy, as it is involved in adaptive and restorative processes, i.e., neuroplasticity.

Induction of growth cessation by acacetin via β-catenin pathway and apoptosis by apoptosis inducing factor activation in colorectal carcinoma cells.

Acacetin, a bioflavanoid, contains anti-inflammatory and anti-cancer activities as shown in different experimental models. However, its anticancer potential and mechanism of action against colorectal cancer cells is largely unknown. Here, we have investigated the efficacy of acacetin using two colorectal adenocarcinoma SW480 and HCT-116 cell lines. Cell survival was examined by Trypan-blue exclusion and MTT assays, cell cycle analysis by FACS, apoptosis was assessed using Annexin V FITC assay and nuclear condensation by Hoechst staining, ROS level by DCFDA and Mitosox, and protein expression level by Western blotting. Acacetin reduced the cell survival and proliferation of both types of cells, and induced S- and G2-M phase arrest and also reduced the levels of β-catenin and its downstream target c-myc. Further, acacetin induced apoptosis as examined by Annexin-V FITC and nuclear condensation. It increased intracellular ROS production, especially mitochondrial ROS. Acacetin increased mitochondrial membrane potential depolarization and Bax:Bcl-2 ratio. Although significant changes in caspases -8 and -9 and PARP level was not observed, acacetin could induce the truncation and subsequent translocation of activated AIF from mitochondria to cytosol, which could further induce chromosomal breakage leading to apoptosis. In conclusion, Acacetin induces mitochondrial ROS-mediated cell death in a caspase-independent manner in SW480 and HCT-116 colon carcinoma cells by inducing apoptosis inducing factor (AIF), which may potentiate its anticancer and chemotherapeutic prospects against colorectal carcinoma.

Novel application of amino-acid buffered solution for neuroprotection against ischemia/reperfusion injury.

Ischemic neuron loss contributes to brain dysfunction in patients with cardiac arrest (CA). Histidine–tryptophan–ketoglutarate (HTK) solution is a preservative used during organ transplantation. We tested the potential of HTK to protect neurons from severe hypoxia (SH) following CA. We isolated rat primary cortical neurons and induced SH with or without HTK. Changes in caspase-3, hypoxia-inducible factor 1-alpha (HIF-1α), and nicotinamide adenine dinucleotide phosphate oxidase-4 (NOX4) expression were evaluated at different time points up to 72 h. Using a rat asphyxia model, we induced CA-mediated brain damage and then completed resuscitation. HTK or sterile saline was administered into the left carotid artery. Neurological deficit scoring and mortality were evaluated for 3 days. Then the rats were sacrificed for evaluation of NOX4 and H2O2 levels in blood and brain. In the in vitro study, HTK attenuated SH- and H2O2-mediated cytotoxicity in a volume- and time-dependent manner, associated with persistent HIF-1α expression and reductions in procaspase-3 activation and NOX4 expression. The inhibition of HIF-1α abrogated HTK’s effect on NOX4. In the in vivo study, neurological scores were significantly improved by HTK. H2O2 level, NOX4 activity, and NOX4 gene expression were all decreased in the brain specimens of HTK-treated rats. Our results suggest that HTK acts as an effective neuroprotective solution by maintaining elevated HIF-1α level, which was associated with inhibited procaspase-3 activation and decreased NOX4 expression.

Relationship between loss of desiccation tolerance and programmed cell death (PCD) in mung bean (Vigna radiata) seeds.

Mung bean (Vigna radiata), an important legume crop, has the property of desiccation tolerance (DT), which is lost in the final stage of germination (preimbibition, 18 h-24 h). We compared parameters related to the programmed cell death (PCD) of mung bean seeds before and after dehydration at different imbibition stages through various detection methods. The results of Evans blue and TTC staining methods showed that the dehydration process could lead to cell death. The results of optical and subcellular morphology showed that PCD occurred after dehydration. The destruction of DNA integrity and the activity changes in caspase and total nuclease in mung bean seeds after dehydration treatment indicated that the loss of desiccation tolerance was related to PCD. Dehydration resulted in the destruction of the mitochondrial structure, reversal of the membrane potential, and the entrance of cytochrome C into the cytoplasm. These processes all indicate that the mitochondrial apoptosis pathway was the main form of dehydration-induced PCD. The results of cytoplasmic Ca2+ concentration showed that Ca2+ signaling also played a role in inducing PCD, with the upstream signal being dehydration-induced changes in water potential and the downstream signal being the ROS and mitochondrial PT channel, according to the order in which these signals happened. The mitochondrial apoptosis pathway can be considered the main mechanism of dehydration-induced PCD based on our analysis of the sequence of major events in PCD. The main processes include dehydration induction, changes in Ca2+ and mitochondrial respiratory electron transport, the reversal of mitochondrial membrane potential induced by ROS and Ca2+, and the transmission and execution of PCD downstream signals induced by cytochrome C release.

MiR-890 inhibits proliferation and invasion and induces apoptosis in triple-negative breast cancer cells by targeting CD147

BackgroundTriple-negative breast cancer (TNBC) is a type of breast cancer with a high degree of malignancy. Because of the remarkable biological characteristics of high invasion, metastasis and recurrence, TNBC is often accompanied by a poor prognosis. As a molecular characteristic of TNBC, high expression of CD147 has been confirmed by a large number of studies. However, the mechanism of CD147 expression regulation in TNBC remains elusive. In this study, we investigated the roles of miR-890 in inhibiting CD147.MethodsQuantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) was used to detect CD147 mRNA and miR-890 level, and western blotting was used to detect CD147 protein. Bioinformatics screening and 3′-Untranslated Region (3′-UTR) luciferase assays were used to analyze the microRNAs (miRNA) binding site. Cell proliferation, apoptosis and invasion were assessed by using CCK-8, flow cytometry and transwell assays.ResultsThe upregulation of miR-890 inhibited cell proliferation and invasion, induced apoptosis in MDA-MB-231 and HCC-70 TNBC cells by negatively regulating its target gene, CD147, and the upregulation of CD147 rescued the inhibitory effects of miR-890. miR-890 targeted CD147 by binding to its 3′-UTR. Further results showed that the upregulation of miR-890 also inhibited the expression of MMPs, the downstream genes of CD147, and promoted the cleavage of Caspase-3. The CD147 recovery experiment was further confirmed by the activity changes in the downstream MMPs of CD147. In addition, it was confirmed that the effect of CD147 in promoting TNBC cell proliferation and invasion, inhibiting apoptosis was related to the change in caspase-3 activity.ConclusionThe downregulation of miR-890 is the potential cause of high CD147 expression in TNBC, which can promote the malignant transformation of TNBC.

The anti-tumor growth effect of a novel agent DMAMCL in rhabdomyosarcoma in vitro and in vivo

BackgroundRhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children with poor survival. New treatment approaches are urgently needed to improve treatment efficacy in RMS patients. DMAMCL is a novel agent from Asteraceae family that has been tested in phase I clinical trials in adult glioma in Australia.MethodsFive RMS cell lines (RD, RH18, RH28, RH30 and RH41) were used. The in vitro anti-tumor effect of DMAMCL, alone or in combination with VCR or Epirubicin, was studied using MTS assay or IncuCyte-Zoom cell confluency assay, and further validated by xenograft-mouse model in vivo. Changes in caspase-3/7 activity, cell-cycle progression and generation of ROS after DMAMCL treatment were investigated. Bim mRNA expression was measured by RT-qPCR, and protein expressions of Bim and phosphorylated-NF-κB(p65) by Western blotting. Small interfering RNAs (siRNA) of Bim were used to study the role of Bim in DMAMCL-induced cell death.ResultsIn vitro, DMAMCL treatment induced a dose-dependent increase in cell death that could be blocked by pan-caspase-inhibitor-Z-VAD-fmk in five RMS cell lines. The percent of cells in SubG1 phase and activities of caspase-3/7 increased after DMAMCL treatment; The combination of DMAMCL with VCR or Epirubicin significantly increased cell death compared to each reagent alone. In vivo, DMAMCL(75 mg/kg or 100 mg/kg) inhibited tumor growth and prolonged survival of mice bearing xenograft RMS tumors (RD, RH18, RH30, RH41). Compared to treatment with DMAMCL or VCR, a combination of two reagents caused significant inhibition of tumor growth (RD, RH41), even after treatment termination. The expression of Bim increased at protein level after DMAMCL treatment both in vitro and in vivo. The expression of p-NF-κB(p65) had a transient increase and the generation of ROS increased after DMAMCL treatment in vitro. Transfection of Bim siRNA into RMS cells blocked the DMAMCL-induced increase of Bim and partially attenuated the DMAMCL-induced cell death.ConclusionDMAMCL had an anti-tumor growth effect in vitro and in vivo that potentially mediated by Bim, NF-κB pathway and ROS. A combination of DMAMCL with chemotherapeutic drugs significantly increased the treatment efficacy. Our study supports further clinical evaluation of DMAMCL in combination with conventional chemotherapy.

Melatonin regulates tumor aggressiveness under acidosis condition in breast cancer cell lines.

Breast cancer progression is composed of multiple steps that are influenced by tumor cell adaptations to survive under acidic conditions in the tumor microenvironment. Regulation of this cell survival behavior is a promising strategy to avoid cancer development. Melatonin is a natural hormone produced and secreted by the pineal gland capable of modulating different biological pathways in cancer. Although the anti-cancer effects of melatonin are currently widespread, its role in the acid tumor microenvironment remains poorly understood. The aim of the present study was to investigate the effect of low pH (6.7) on human breast cancer cell lines MCF-7 and MDA-MB-231, and the effectiveness of melatonin in acute acidosis survival mechanisms. Cell viability was measured by a MTT assay and the protein expression of glucose transporter (GLUT)-1, Ki-67 and caspase-3 was evaluated by immunocytochemical (ICC) analysis following low pH media and melatonin treatment. In both cell lines the viability was decreased after melatonin treatment (1 mM) under acidosis conditions for 24 h. ICC analysis showed a significant increase in GLUT-1 and Ki-67 expression at pH 6.7, and a decrease after treatment with melatonin for 12 and 24 h. The low pH media decreased the expression of caspase-3, which was increased after melatonin treatment for 12 and 24 h. Overall, the results of the present study revealed melatonin treatment increases apoptosis, as indicated by changes in caspase-3, and decreases proliferation, indicated by changes to Ki-67, and GLUT-1 protein expression under acute acidosis conditions in breast cancer cell lines.

Investigation of novel chemotherapeutics for feline oral squamous cell carcinoma.

Feline oral squamous cell carcinomas (FOSCC) are highly aggressive neoplasms with short survival times despite multimodal treatment. FOSCC are similar to squamous cell carcinomas of the head and neck (SCCHN) in humans, which also present therapeutic challenges. The current study was undertaken to identify novel chemotherapeutics using FOSCC cell lines. A high throughput drug screen using 1,952 drugs was performed to identify chemotherapeutics for further investigation. Two of the drugs identified in the drug screen, actinomycin D and methotrexate, and two drugs with similar molecular targets to drugs found to be efficacious in the screening, dinaciclib and flavopiridol, were selected for further investigation. Drug inhibition profiles were generated for each drug and cell line using an MTS assay. In addition, the effects of the drugs of interest on cell cycle progression were analyzed via a propidium iodide DNA labeling assay. Changes in caspase-3/7 activity after treatment with each drug were also determined. The findings demonstrated effectiveness of the drugs at nanomolar concentrations with sensitivity varying across cell lines. With all of the drugs except for actinomycin D, evidence for G1 arrest was found. Dinaciclib and flavopiridol were demonstrated to induce apoptosis. The results of the study suggest that the selected drugs are potential candidates for developing novel chemotherapeutic approaches to FOSCC. Through these studies, novel therapeutic strategies for the treatment of FOSCC can be developed to provide better care for affected cats which can also serve as proof of concept studies to inform translational studies in SCCHN in humans.

An answer to colon cancer treatment by mesenchymal stem cell originated from adipose tissue.

Objective(s):Colon cancer is risen up with its complex mechanism that directly impacts on its treatment as well as its common prevalence. Mesenchymal stem cells (MSCs) have been considered as a therapeutic candidate for conventional disease including cancer. In this research, we have focused on apoptotic effects of adipose tissue-derived MSCs in colon cancer.Materials and Methods:MSCs were obtained from adipose tissue and characterized by Flowcytometer using suitable antibodies. MSCs, HT-29, HCT-116, RKO and healthy cell line MRC5 were cultured by different seeding procedure. After cell viability assay, changes in caspase 3 enzyme activity and the level of phosphatidylserine were measured.Results:For cell viability assay, a 48 hr incubation period was chosen to seed all cells together. There was a 1.36-fold decrease in caspase 3 enzyme activity by co-treatment of RKO and MSCs in addition to 2.02-fold decrease in HT-29 and MSCs co-treatment, and 1.103-fold increase in HCT-116 and MSCs. The results demonstrated that HCT-116 led to the highest rate of apoptotic cell death (7.5%) compared with other cells.Conclusion:We suggest that MSCs might remain a new treatment option for cancer by its differentiation and repair capacity.

Dual function of programmed cell death 10 (PDCD10) in drug resistance

Drug resistance, a major challenge in cancer chemotherapy, is a result of several mechanistic alterations including resistance to apoptosis. Apoptosis is a well-controlled cell death mechanism which is regulated by several signaling pathways. Alterations in structure, function, and expression pattern of the proteins involved in the regulation of apoptosis have been linked to drug resistance. Programmed Cell Death 10 (PDCD10) protein is recently associated with the regulation of cell survival and apoptosis. However, the role of PDCD10 in drug resistance has not been clearly established. Here, we aimed to figure out the role of PDCD10 in resistance to anti-cancer agents in different cell lines. We found that PDCD10 expression was cell- and anti-cancer agent-specific; down-regulated in doxorubicin- and docetaxel-resistant MCF7 cells while up-regulated in doxorubicin-resistant HeLa cells. Down-regulation of PDCD10 expression by siRNA in parental MCF7 cells increased the resistance while it increased sensitivity in doxorubicin-resistant HeLa cells. Similarly, over-expression of PDCD10 in parental HeLa cells increased the resistance to doxorubicin while it re-sensitized doxorubicin-resistant MCF7 cells. Moreover, the alterations in PDCD10 expression led to changes in caspase 3/7 activity and the levels of apoptosis-related genes. Our results point out a possible dual role of PDCD10 in drug resistance for the first time in the literature and emphasize PDCD10 as a novel target for reversal of drug resistance in cancer.

Effects of disodium cantharidinate on dendritic cells of patients with bladder carcinoma

The present study explored the effects of disodium cantharidinate (DC) on the peripheral blood-derived dendritic cells of patients with bladder carcinoma. The peripheral blood mononuclear cells from the 15 cases of urinary bladder carcinoma of middle and advanced stage were separated, and dendritic cells were prepared. The morphological changes of dendritic cells were observed. Flow cytometry was used to detect the expression levels of CD1a and CD83 on dendritic cell surface. MTT assay was utilized to measure the proliferation ability of allogeneic lymphocyte stimulated by DC. Annexin V-FITC/propidium iodide (PI) double staining flow cytometry method was carried out to detect cell apoptosis after treatment with DC. The changes in caspase-3 and PARP expression levels were investigated by western blot method. The high-dose DC resulted in a significant increase in the expressions of dendritic cell phenotyptic molecules CDla and CD83 as compared to control group. In addition, the proliferation index of allogenic lymphocyte stimulated by DC was significantly higher than that of control group. Moreover, MTT assay showed significant inhibition of the growth of BIU-87 cells. After 24 h of DC treatment, double staining flow cytometry confirmed the ability of DC to induce cell apoptosis. Further, western blot method showed a significant elevation of caspase-3 and PARP protein expression after DC treatment. In conclusion, DC treatment could induce dendritic cell maturation of patient with carcinoma of urinary bladder and promote its functional changes. Furthermore, DC was able to inhibit the proliferation of cell BIU-87 and also has the ability to induce cell apoptosis.

Aliskiren Improves Ischemia- and Oxygen Glucose Deprivation-Induced Cardiac Injury through Activation of Autophagy and AMP-Activated Protein Kinase.

Aliskiren is a direct renin inhibitor that has been effective in anti-hypertension. We investigated whether aliskiren could improve the ischemia-induced cardiac injury and whether the autophagy was involved in this effect. A myocardial infarction (MI) model was created by the ligation of the left anterior coronary artery in C57J/BL6 mice. They were treated for 1, 3, 7, and 14 days with vehicle or aliskiren (25 mg/kg/day via subcutaneous injection). In vivo, the MI mice exhibited worse cardiac function by echocardiographic assessment and showed larger myocardial scarring by light microscopy, whereas aliskiren treatment reversed these effects, which were also associated with the changes in caspase-3 and Bcl-2 expression as well as in the number of apoptotic cells. Aliskiren increased autophagy, as demonstrated by LC3B-II expression and transmission electron microscopy. Furthermore, H9c2 cardiomyocytes were employed as an in vitro model to examine the effects of aliskiren on apoptosis and autophagy under oxygen glucose deprivation (OGD)-induced injury. Aliskiren significantly increased cell viability in a dose-dependent manner. The beneficial effects of aliskiren were associated with decreased apoptosis and mitochondrial membrane potential as well as increased autophagy via increased autophagosome formation. We also found that aliskiren-induced cardiomyocyte survival occurred via AMP-activated protein kinase (AMPK)-dependent autophagy. Taken together, these results indicated that aliskiren increased cardiomyocyte survival through increased autophagosomal formation and decreased apoptosis and necrosis via modulating AMPK expression. AMPK-dependent autophagy may represent a novel mechanism for aliskiren in ischemic cardiac disease therapy.

Thrombopoietin protects H9C2 cells from excessive autophagy and apoptosis in doxorubicin-induced cardiotoxicity.

Cardiac toxicity has been the major concern when using doxorubicin (DOX) in cancer therapy. Thrombopoietin (TPO) protects cardiac cells from DOX-induced cell damage; however, its molecular mechanism remains exclusive. The anti-autophagic and anti-apoptotic effects of TPO upon DOX treatment were studied in the cardiac H9C2 cell line, with bafilomycin A1 treatment as a positive control for autophagy inhibition. Cell viability was measured by Cell Counting Kit-8 assay in different treatment groups. The mRNA and/or protein levels of apoptotic markers and autophagy-associated factors were detected. The mean number of microtubule-associated protein 1A/1B-light chain 3 (LC3) puncta per cell was quantified to indicate autophagosomes and autolysosomes, of which the ones co-stained with lysosomal-associated membrane protein 1 were considered as autolysosomes. DOX treatment (5 µg/ml, 24 h) significantly impaired H9C2 cell viability compared with the control, while TPO pretreatment (10 ng/ml, 36 h) improved cell viability upon DOX treatment. DOX exposure markedly increased LC3 puncta in H9C2 cells, and TPO pretreatment reduced the number of autophagosomes, but showed no significant inhibitory effect on autolysosome formation. The autophagy inhibition by TPO upon DOX treatment was confirmed according to protein quantification of LC3-II and nucleoporin 62. TPO also suppressed autophagy-promoting protein Beclin-1, and elevated the anti-autophagic factors GATA-binding protein-4 and B cell lymphoma-2. Furthermore, TPO reduced DOX-induced apoptosis in H9C2 cells, as reflected by the amount changes of caspase-3. Taken together, these results revealed that TPO has a protective role in H9C2 cells from DOX-induced autophagy as well as apoptosis, and indicated that TPO may act as a cardioprotective drug in DOX-treated patients.

Estrogen-induced disruption of intracellular iron metabolism leads to oxidative stress, membrane damage, and cell cycle arrest in MCF-7 cells.

It is well established that several forms of cancer associate with significant iron overload. Recent studies have suggested that estrogen (E2) disrupts intracellular iron homeostasis by reducing hepcidin synthesis and maintaining ferroportin integrity. Here, the ability of E2 to alter intracellular iron status and cell growth potential was investigated in MCF-7 cells treated with increasing concentrations of E2. Treated cells were assessed for intracellular iron status, the expression of key proteins involved in iron metabolism, oxidative stress, cell survival, growth, and apoptosis. E2 treatment resulted in a significant reduction in hepcidin expression and a significant increase in hypoxia-inducible factor 1 alpha, ferroportin, transferrin receptor, and ferritin expression; a transient decrease in labile iron pool; and a significant increase in total intracellular iron content mainly at 20 nM/48 h E2 dose. Treated cells also showed increased total glutathione and oxidized glutathione levels, increased superoxide dismutase activity, and increased hemoxygenase 1 expression. Treatment with E2 at 20 nM for 48 h resulted in a significant reduction in cell growth (0.35/1 migration rate) and decreased cell survival (<80%) as compared with controls. Survivin expression significantly increased at 24 h post treatment with 5, 10, or 20 nM; however, that of γ-H2AX increased only after survivin levels dropped and only at the 20 nM E2 dose. Minimal upregulation and splitting of caspase 9 was only evident in cells treated with 20 nM E2; no changes in caspase 3 expression were evident. Although Annexin V staining studies showed that E2 treatment did not induce apoptosis, scanning electron microscopy studies showed marked membrane blebbing at 20 nM/48 h of E2. These findings suggest that estrogen treatment disrupts intracellular iron metabolism and precipitates adverse effects concerning cell viability, membrane integrity, and growth potential.

The effects of dexamethasone administered during pregnancy on the postpartum spiny mouse ovary.

Excessive exposure to glucocorticoids can alter ovarian function by modulating oogenesis, folliculogenesis and steroidogenesis. The aim of the present study was to examine the effects of dexamethasone (DEX) administered during pregnancy on folliculogenesis and corpus luteum development in the postpartum spiny mouse ovary. DEX (125 μg kg-1 body weight per day) was applied to pregnant spiny mouse from day 20 of gestation to parturition. The obtained ovaries were fixed and used for immunohistochemistry and TEM analysis. The expression of proteins related to apoptosis (caspase-3, Bax, Bcl-2) and autophagy (Beclin1, Lamp1) as well as PCNA and GR receptors were evaluated by western-blot. In comparison with DEX-treated group a higher percentage of TUNEL positive granulosa and luteal cells was observed in the control group. These data were consistent with changes in caspase-3 and Bax expression, which increased in the control and decreased after DEX exposure. In turn, the proliferation index and PCNA expression were higher in the DEX-treated group. Moreover, the higher level of Beclin1, Lamp1, anti-apoptotic Bcl-2 protein and GR was observed in the DEX-treated females than in the control group. Beclin1 and Lamp1 were strongly expressed in luteal cells which exhibited an autophagic ultrastructure. Surprisingly, DEX augmented the number of ovarian follicles and corpora lutea, which resulted in a significant increase in ovarian weight. These findings suggest that DEX exerts anti-apoptotic action on granulosa layer and stimulates follicular maturation. Moreover, DEX induces autophagy in luteal cells promoting cell survival rather than cell death, which can prolong the corpus luteum life span.

Abstract 319: Cholesterol inhibition reduces Hh mediated chondrosarcoma

Abstract Constitutive activation of Hh signaling is a common occurrence in chondrosarcoma(CSA). Gene profiling analysis showed that Gli transcription regulates genes that govern cholesterol homeostasis, which alters cholesterol accumulation in chondrocytes; a higher level of Gli-mediated transcription results in accumulation of intracellular cholesterol. Here we determined if targeting cholesterol-processing genes downstream of Hh signalling could be used as a novel treatment approach. With institutional review board approval, human CSA samples were obtained fresh from surgery. For in vitro studies, CSA explants of 2mmx2mm x2 mm cubic in size establihed as organ cultures. For in vivo studies, one million CSA cells were subcutanously injected into NSG mice. Cells from five CSAs were treated both in vitro and in vivo with a hedgehog inhibitor, Cur61414, a cholesterol inhibitor, Lovastatin, or both. In vitro, CSA explants were treated for 48 hrs at concentration of 20 μM of each drug. In vivo, mice were treated with 4.5mg/kg/day of Cur61414, Lovastatin, or both by intraperitoneal injection for 4 wks. At the end of treatment, the explants or xenografts were harvested and processed for further analysis. RT-PCR was used to meausre the expression of Hh and cholesterol target genes. Tumor size was meausred from the xenografts. Blockade of Hh signaling significantly decreased Gli1 gene expression by 30%, increased 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) expression for more than 300% indicating decreased intracellular cholesterol. Treatment with the cholesterol inhibitor Lovastatin increased expression of HMGCR for more than 500%. The combination of Hh and cholesterol blockage resulted in increased expression of HMGCR for more than 3400%. Analysis of chondrosarcoma xenografts in vivo showed a significnat decrease in tumor size with Lovastatin (32% decline), 3 folds reducation of Brdu(+) cells, and 2.4 fold increase of Caspase-3 + cells, treatment with Cur 61414 reduced the tumor growth by 5% with no significant reduction of Brdu(+) cells but 2.6 fold increase of Caspase-3 (+) cells . The combination treatment of lovastatin and Cur61414 on xenografts resulted in a significnat decrease in tumor size (32% decline), 3 fold reduction of Brdu (+) cells, but no significant changes of Caspase-3 (+) cells . These data suggest that cholesterol functions downstream of Hh signaling pathway in CSA. The more effective reduction in tumor growth with cholesterol inhibition compared to Hh blockade suggests cholesterol blockade is an effective therapeutic approach. Citation Format: Qingxia Wei, Eyal Ramu, Mushriq AL-Jazrawe, Raymond Poon, Jay Wunder, Benjamin Alman. Cholesterol inhibition reduces Hh mediated chondrosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 319. doi:10.1158/1538-7445.AM2017-319

Effects of Silver Nanoparticle on the Developing Liver of Rat Pups after Maternal Exposure.

The extensive application of silver nanoparticles (AgNPs) has been increased due to their antimicrobial properties, however numerous concerns has been arisen about their toxicity potential. Since nanoparticles can cross through the placenta and accumulate in the embryonic organs especially liver, in this study, developmental hepatotoxicity of AgNPs was investigated. Pregnant rats were divided into two groups, vehicle control group and treated group. Treated group received AgNPs (25 mg/Kg) through intra-gastric gavage in a period of gestational days 1-19. Pups were sacrificed after the birth and their livers collected. Histopathology, ICP- mass spectrometry, Spectrophotometric assay, and ELISA were employed to evaluate AgNPs toxicity in the liver of pups. Glutathione peroxidase (GPX) activity and glutathione (GSH) level were significantly decreased and malondialdehyde (MDA) and caspase 9 levels were significantly increased, although there was no significant change in caspase 8 content in the liver of offspring. Fatty degeneration and congested dilated sinusoids were also observed in histo-pathological examination. These results suggest that maternal oral exposure to AgNPs may induce oxidative stress and apoptosis in the liver of their offspring. Further investigations are required to clarify molecular events behind this happening.