Downregulation Of Caspase-3 Research Articles

Resveratrol Ameliorates Retinal Ischemia/Reperfusion Injury in C57BL/6J Mice via Downregulation of Caspase-3

ABSTRACTPurpose: Ischemia/reperfusion (I/R) injury induces apoptosis in retinal ganglion cells (RGCs). Resveratrol (Res) is a potent natural antioxidant with beneficial effects in many ocular diseases, such as age-related macular degeneration, diabetic retinopathy, and glaucoma. Because caspase-3 expression is highly correlated with activation of the apoptotic pathway, the present study aimed to determine whether Res regulates the expression of caspase-3 using an I/R retinal injury mouse model.Methods: Male C57BL/6J mice were injected with Res for 2 consecutive days before I/R retinal injury. I/R retinal injury was induced by increasing the intraocular pressure for 1 h. Res was then injected for 3 consecutive days. Changes in retinal morphology were monitored for 3 days after injury by histochemistry using hematoxylin and eosin staining. mRNAs and proteins were extracted 2 days after injury. The expression levels of caspase-8 and caspase-3 mRNA and protein were determined using reverse-transcriptase polymerase chain reaction (RT-PCR) and western blot analyses.Results: I/R injury induced declines in retinal thickness and number of RGCs during 5 days after injury. Caspase-8 and caspase-3 mRNA and protein activation increased. Res treatment reduced the significant loss of retinal morphology and downregulated the expression of mRNA and activation of caspase-8 and caspase-3 protein.Conclusions: The observed changes in retinal morphology suggest that I/R injury promotes retinal degeneration. Increased expression of caspase-8 and caspase-3 mRNA indicates apoptosis activation. Res, however, suppresses apoptosis via downregulation of caspase-8 and caspase-3 expression.

Diazoxide prevents H2O2-induced chondrocyte apoptosis and cartilage degeneration in a rat model of osteoarthritis by reducing endoplasmic reticulum stress

Osteoarthritis (OA) is a common disease affecting elderly individuals. Its incidence rises sharply with age, and chondrocyte apoptosis plays a vital role in its pathogenesis. Diazoxide opens mitochondrial ATP-sensitive potassium (mitoKATP) channels and exerts multiple pharmacological effects, including reductions in blood pressure and blood sugar levels. It also exerts anti-apoptotic activities, but the cellular and molecular mechanisms by which diazoxide inhibits chondrocyte apoptosis are unknown, as is whether apoptosis is related to endoplasmic reticulum stress (ERS). In the present study, we explored the mechanism underlying the chondroprotective effect of diazoxide on hydrogen peroxide (H2O2)-stimulated chondrocyte apoptosis in rats with surgically induced OA. A cell counting kit-8 (CCK-8) assay showed that the viability of H2O2-stimulated chondrocytes was enhanced in a dose-dependent manner. However, at a concentration ≥400μM, diazoxide had other, negative effects. The protective effect of diazoxide in vitro included inhibition of the ERS response and of mitochondrial dysfunction induced by H2O2 stimulation. These responses were related to activation of the PERK1/2 and ERK1/2 signaling pathways; the prevention of chondrocyte apoptosis; the down-regulation of caspase-3, Bax, ATF-6 and C/EBP-homologous protein (CHOP) expression; and the up-regulation of Bcl-2 and Col II. In vivo, histological and immunohistochemical analyses of caspase-3 and CHOP expression revealed that diazoxide ameliorated cartilage degeneration in a rat model of OA, as revealed by histological and immunohistochemical analyses of caspase-3 and CHOP expression. Diazoxide suppressed H2O2-triggered chondrocyte apoptosis, and ameliorated cartilage degeneration, by inhibiting the development of ERS.

The neuroprotective role of rosiglitazone in advanced glycation end product treated human neural stem cells is PPARgamma-dependent.

Hyperglycemia is accompanied by an accelerated formation rate of advanced glycation end products (AGEs), which is associated with the pathogenesis of diabetic neuronal deficits. Peroxisome proliferator-activated receptor gamma (PPARγ) belongs to a family of ligand-activated nuclear receptors and its ligands are known to control many physiological, pathological and inflammatory pathways. Weinvestigated the hypothesis that the PPARγ agonist (rosiglitazone) would abrogate AGEs-mediated neurotoxic effects on human neural stem cells (hNSCs), by whichAGEs may play a role in diabetic-related neuronal impairment. Here, we show that rosiglitazone treatment increases cell viability of hNSCs via downregulation of caspase 3 activity. These rescue effects were extended in our studies showingrosiglitazone-mediated activation of PPARγ reversed the expression levels of two neuroprotective factors (Bcl-2 and PGC1α) that were downregulated in hNSCs exposed to AGEs alone. The stimulation of mitochondrial function and anti-oxidative stress by rosiglitazone was associated with activation of the PGC1α pathway by up-regulation of mitochondrial (NRF-1 and Tfam) and oxidative defense (SOD1, SOD2 and Gpx1) genes. Moreover, rosiglitazone significantly normalized the inflammatory responses (TNF-α and IL-1β), NF-κB (p65), and inflammatory genes (iNOS and COX-2) in the hNSCs treated with AGEs. This neuroprotective effect of rosiglitazone was effectively blocked by PPARγ-specific antagonist (GW9662), demonstrating that the action of rosiglitazone was mediated by at PPARγ-dependent pathway. Collectively, these novel findings show AGEs induce neurotoxic effects in hNSCs, and provide important mechanistic insights that may explain the increased risk of neuronal impairment deficits in diabetic patients. More importantly, these data show rosiglitazone-mediated activation of PPARγ-dependent signaling is neuroprotective in AGE-treated hNSCs, and suggests PPARγ ligands may be useful in the therapeutic management of patients with neurodegenerative diseases.

The post-therapeutic effect of rapamycin in mild traumatic brain-injured rats ensuing in the upregulation of autophagy and mitophagy.

Mild traumatic brain injury (mTBI), common in juveniles, has been reported to be caused by sports-related concussion. Many young children may suffer from post-concussion syndrome. mTBI, in early stages of life, could play a part in neuron apoptosis and degeneration, cognitive and motor coordination impairment, as well as dementia. Our study was aimed at further investigating the post-therapeutic efficacy of rapamycin in the recuperation of mTBI while at the same time investigating the metamorphosis in both autophagy and mitophagy in mTBI. We created a weight-drop rat mTBI model with the administration of rapamycin at 4 h after every mTBI. Behavioral tests of beam walking and open field task indicated the expected improvement of cognitive and motor coordination functions. Both Western blot and immunofluorescence examinations revealed increased Beclin-1 and PINK1 in the treated rats as well as reduction of caspase-3 and cytochrome C (Cyt C). More so, the TUNEL staining evidenced curtailment of apoptotic cells following treatment with rapamycin. The upregulation of Beclin-1 and PINK1 and the downregulation of caspase-3 and Cyt C extrapolate that rapamycin plays neuroprotective as well as anti-apoptotic role via interposition of both autophagy and mitophagy.

Abstract 2243: Elucidating the mechanism of action of molecular iodine on breast cancer cells

Abstract Each year, over 1.7 million women are diagnosed with breast cancer worldwide and about 35% of these diagnosed are expected to die from the disease. A significant barrier to improving treatment of breast cancer lies in our incomplete understanding of breast cancer initiation and metastasis. Regular use of molecular iodine has been shown to reduce the sensitivity of breast cells to the proliferative effects of estrogen, resulting in normalization of breast tissue.The aim of the current study was to evaluate the mechanisms of molecular iodine on two common breast cancer sub-types using well-established breast cancer cell lines. In order to study Luminal A and triple-negative breast cancer in vitro, MCF7 (cells from a luminal A subtype) and MDA-MB231 (cells from a triple-negative subtype), were treated with molecular iodine at various concentrations to measure proliferation and cell death. This was subsequently followed by gene expression analysis of key important molecular markers, which are primarily responsible for cell growth and apoptosis. Primary human mammary epithelial cells derived from healthy female donor were used as an internal control. Data from this study indicated that molecular iodine had potent inhibitory effects on cell growth and showed a dramatic increase in cell death in both breast cancer cell lines. Gene expression analysis using quantitative RT-PCR further confirmed that cell cycle genes controlling G1-S phase transition were largely up-regulated. Changes were not seen in Cyclin B expression levels, which further suggest that cells were arrested before entry into cell division. BCL-2, PPAR-α and PPAR-γ were also up-regulated along with down-regulation of Caspase 3, suggesting molecular iodine induced cell death through activation of a caspase-independent apoptosis pathway. Interestingly, mesenchymal-epithelial transition (MET) occurrence was noticed upon molecular iodine treatment as indicated by sharp increase of GATA3 and E-Cadherin and significant down-regulation of Vimentin in invasive MDA-MB231 cells. Our current study enables us to understand a molecular mechanism controlling tumor cell growth and demonstrates potent cellular effects of molecular iodine on breast cancer cell lines. These results also demonstrate promising effects of molecular iodine for regulation of breast cancer EMT differentiation, which is required for tumor initiation and metastasis. Further studies are underway to determine possible effects of molecular iodine in these breast cancer subtypes using in vitro 3D models. Note: This abstract was not presented at the meeting. Citation Format: Zack Xu, Xin Chen, Noymi Yam, kin Chan, Usha Nagavarapu. Elucidating the mechanism of action of molecular iodine on breast cancer cells [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 2243. doi:10.1158/1538-7445.AM2017-2243

PCDH18 is frequently inactivated by promoter methylation in colorectal cancer

Protocadherin18 (PCDH18) was found to be preferentially methylated and inactivated in colorectal cancer (CRC) using bioinformatics tools. However, its biologic role in tumorgenesis remains unclear. Herein, we aimed to elucidate its epigenetic regulation and biological functions in CRC. The methylation status of PCDH18 was significant higher in CRC tissues than in adjacent non-tumor tissues (median, 15.17% vs. median, 0.4438%). Expression level of PCDH18 was significantly lower in primary CRCs than in nonmalignant tissues. Importantly, methylation status of PCDH18 in cell-free DNA of CRC patients was also significantly higher than in healthy subjects. PCDH18 was readily expressed in NCM460 cells, but downregulated in 100% (4/4) of CRC cell lines by promoter methylation, despite its expression could be restored through demethylation treatment. Overexpression of PCDH18 suppressed CRC cell viability, colony formation and migration. Meanwhile, the depletion of PCDH18 by siRNA in NCM460 cells enhanced the colonogenicity and migration ability and promoted β-catenin nuclear accumulation, whereas it inhibited cell cycle arrest. These effects were associated with upregulation of phospho-GSK-3β and cyclin D1, and downregulation of caspase3 and p21. Our results suggested that PCDH18 was a putative tumor suppressor with epigenetic silencing in CRC and a potential biomarker for CRC diagnosis.

Proteomic characterization of EL4 lymphoma-derived tumors upon chemotherapy treatment reveals potential roles for lysosomes and caspase-6 during tumor cell death in vivo.

The murine mouse lymphoblastic lymphoma cell line (EL4) tumor model is an established in vivo apoptosis model for the investigation of novel cancer imaging agents and immunological treatments due to the rapid and significant response of the EL4 tumors to cyclophosphamide and etoposide combination chemotherapy. Despite the utility of this model system in cancer research, little is known regarding the molecular details of in vivo tumor cell death. Here, we report the first in-depth quantitative proteomic analysis of the changes that occur in these tumors upon cyclophosphamide and etoposide treatment in vivo. Using a label-free quantitative proteomic approach a total of 5838 proteins were identified in the treated and untreated tumors, of which 875 were determined to change in abundance with statistical significance. Initial analysis of the data reveals changes that may have been predicted, such as the downregulation of ribosomes, but demonstrates the robustness of the dataset. Analysis of the dataset also reveals the unexpected downregulation of caspase-3 and an upregulation of caspase-6 in addition to a global upregulation of lysosomal proteins in the bulk of the tumor.

Shielding Engineered Islets With Mesenchymal Stem Cells Enhance Survival Under Hypoxia.

In the present study we focused on the improvisation of islet survival in hypoxia.The Islet like cell aggregates (ICAs) derived from wharton's jelly mesenchymal stem cells (WJ MSC) were cultured with and without WJ MSC for 48 h in hypoxia and normoxia and tested for their direct trophic effect on β cell survival. The WJ MSCs themselves secreted insulin upon glucose challenge and expressed the pancreatic markers at both transcription and translational level (C-peptide, Insulin, Glucagon, and Glut 2). Direct contact of MSCs with ICAs facilitated highest viability under hypoxia as evidenced by fluorescein diacetate/propidium iodide and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cytokine analysis of the co-cultured ICAs revealed amplification of anti-inflammatory cytokine like TGFβ and TNFα accompanied by depletion of pro-inflammatory cytokines. The increment in VEGF and PDGFa was also seen showing their ability to vascularize upon transplantation. This was further accompanied by reduction in total reactive oxygen species, nitric oxide, and super oxide ions and down regulation of Caspase3, Caspase8, p53, and up regulation of Bcl2 confirming prevention of apoptosis in ICAs. The western blot analysis confirmed the cytoprotective effect of WJ MSC on ICAs as they enhanced the anti-apoptotic marker BCL2 and reduced the expression of apoptotic markers, Annexin 5 and Caspase 3. There was a significant reduction in the expression of p38 protein in the presence of MSCs making the ICAs responsive to glucose. Taken together our data demonstrate for the first time that the WJ MSC expressed pancreatic markers and their supplementation protected engineered islets against hypoxia and oxidative stress. J. Cell. Biochem. 118: 2672-2683, 2017. © 2017 Wiley Periodicals, Inc.

The promoting effects of insulin-like growth factor 1 on the biological behaviour of human retinal vascular endothelial cells

Background The suppression of retinal angiogenesis is one of primary treatment targets for retinal vascular diseases, so seeking the intervention targets of retinal neovascularization is a hot research.Studies showed that insulin-like growth factor 1 (IGF-1) can promote the growth and restrain the apoptosis of vascular endothelial cells.However, whether IGF-1 is an intervention target for the treatment of retinal vascular diseases is unelucidated. Objective This study was to address the effects of IGF-1 on the migration, apoptosis and capillary tube formation of human retinal vascular endothelial cells (HRECs) and mechanism. Methods HRECs were cultured in vitro, and the cells in the exponential phase were prepared for subsequent experiments.The expression of IGF-1R mRNA in the cells was examined using reverse transcriptase PCR assay.Different concentrations of IGF-1 were added in the medium based on the difference of tests.The relative free-cell area difference (ΔS) after test was measured by Photoshop CS4 software and compared among 0, 10 and 200 ng/ml IGF-1 groups 12 and 24 hours after cell scratching, respectively.The cell apoptotic rate was assayed by flow cytometry and compared between 0 ng/ml IGF-1 group and 1 000 ng/ml IGF-1 group, and the number of capillary tubes was examined by Matrigel test and assessed among 0, 10, 100 and 200 ng/ml IGF-1 groups 24 hours after addition of IGF-1.The expressions of platelet derived growth factor (PDGF)-BB mRNA and caspase-3 mRNA in the cells of the 0, 500 and 1 000 ng/ml IGF-1 groups were detected by real-time fluorescence quantitative PCR after adding IGF-1 for 6 hours. Results Cultured cells grew well and attached 90% confluence 2-3 days after incubation, and IGF-1R mRNA was positively expressed in the cells.In 12 and 24 hours after scratching, the relative migrating area of the cells was gradually reduced with the increase of IGF-1 contents.The ΔS was (4.83±0.61)×105 μm2 in the 200 ng/ml IGF-1 group, which was significantly larger than (3.28±0.64) ×105 μm2 in the 0 ng/ml IGF-1 group 24 hours after stretching (t=-3.707, P=0.021). The apoptotic rate in the 0 ng/ml IGF-1 group and 1 000 ng/ml IGF-1 group was (18.77±2.37)% and (12.05±0.88)%, with a significant difference between them (t=2.869, P=0.046). The number of intact tubes was significantly increased in the 200 ng/ml IGF-1 group compared with the 0 ng/ml IGF-1 group ([20.33±2.83]/well vs.[17.94±1.96]/well; t=-2.940, P=0.042). Compared with 0 ng/ml IGF-1 group, the relative expression level of PDGF-BB mRNA was elevated and that caspase-3 mRNA was evidently reduced in the 1 000 ng/ml IGF-1 group (t=-3.489, P=0.025; t=7.287, P=0.002). Conclusions IGF-1 can promote the migration and angiogenesis of HRECs and inhibit the apoptosis of HRECs.These effects of IGF-1 probably are associated with the up-regulation of PDGF-BB and down-regulation of caspase-3 in the cells. Key words: Insulin-like growth factor 1/metabolism; Retinal vascular endothelial cells; Angiogenesis; RNA, messenger/analysis; Migration; Apoptosis; Human

MutY DNA Glycosylase Protects Cells From Tumor Necrosis Factor Alpha-Induced Necroptosis.

Numerous studies have implied that mutY DNA glycosylase (MYH) is involved in the repair of post-replicative mispairs and plays a critical role in the base excision repair pathway. Recent in vitro studies have shown that MYH interacts with tumor necrosis factor receptor type 1-associated death domain (TRADD), a key effector protein of tumor necrosis factor receptor-1 (TNFR1) signaling. The association between MYH and TRADD is reversed during tumor necrosis factor alpha (TNF-α)- and camptothecin (CPT)-induced apoptosis, and enhanced during TNF-α-induced survival. After investigating the role of MYH interacts with various proteins following TNF-α stimulation, here, we focus on MYH and TRADD interaction functions in necroptosis and its effects to related proteins. We report that the level of the MYH and TRADD complex was also reduced during necroptosis induced by TNF-α and zVAD-fmk. In particular, we also found that MYH is a biologically important necrosis suppressor. Under combined TNF-α and zVAD-fmk treatment, MYH-deficient cells were induced to enter the necroptosis pathway but primary mouse embryonic fibroblasts (MEFs) were not. Necroptosis in the absence of MYH proceeds via the inactivation of caspase-8, followed by an increase in the formation of the kinase receptor- interacting protein 1 (RIP1)-RIP3 complex. Our results suggested that MYH, which interacts with TRADD, inhibits TNF-α necroptotic signaling. Therefore, MYH inactivation is essential for necroptosis via the downregulation of caspase-8. J. Cell. Biochem. 118: 1827-1838, 2017. © 2017 Wiley Periodicals, Inc.

DNA methylation-mediated caspase-8 downregulation is associated with anti-apoptotic activity and human malignant glioma grade.

The methylation-mediated silencing of tumor suppressors, including key apoptosis-related genes plays an important role in the pathogenesis and therapeutic resistance in human cancer. In this study, we aimed to elucidate the role and mechanisms of resistance to apoptosis with caspase-8 gene downregulation in human malignant glioma. Reverse transcription-polymerase chain reaction (RT-PCR) and methylation-specific PCR(MSP) were used to examine caspase-8 expressoin at the mRNA level and gene methylation status in normal brain tissue, glioma tissue and cancer cell lines. Caspase-8 protein kinase activity was measured by caspase-8 colorimetric assays; cell apoptosis was examined by AnnexinV/propidium iodide(PI) staining; the rates of tumor cell apoptosis were detected by flow cytometry. Our results revealed that caspase-8 gene silencing may result from the methylation of its gene promoter in human glioma tissues. The expression of caspase-8 at the mRNA level was significantly associated with the grade of human glioma. In certain human cancer cell lines, the expression at the mRNA level, protein kinase activity and tumor cell anti-apoptotic activity and resistance were related to the methylation status of the caspase-8 gene promoter. Thus, the caspase-8 gene methylation status may be used as an indicator for the early diagnosis of human malignant glioma. Combination therapy with demethylation reagents may overcome therapeutic resistance in the same malignancy.

Knockdown of TCTN1 Strongly Decreases Growth of Human Colon Cancer Cells.

BackgroundTectonic family member 1 (TCTN1), a member of the tectonic family, is involved in several developmental processes and is aberrantly expressed in multiple solid tumors. However, the expression and regulation of TCTN1 in human colorectal cancer (CRC) is still not clear.Material/MethodsThe expression of TCTN1 mRNA was first explored by using Oncomine microarray datasets. TCTN1 expression was silenced in human CRC cell lines HCT116 and SW1116 via RNA interference (RNAi). Furthermore, we investigated the effect of TCTN1 depletion on CRC cell growth by MTT, colony formation, and flow cytometry in vitro.ResultsIn this study, meta-analysis showed that the expressions of TCTN1 mRNA in CRC specimens were significantly higher than that in normal specimens. Knockdown of TCTN1 expression potently inhibited the abilities of cell proliferation and colony formation as determined. Flow cytometry analysis showed that depletion of TCTN1 could cause cell cycle arrest at the G2/M phase. In addition, Annexin V/7-AAD double-staining indicated that TCTN1 silencing promoted cell apoptosis through down-regulation of caspase 3 and Bcl-2 and upregulation of cleaved caspase 3 and PARP.ConclusionsOur results indicate that TCTN1 may be crucial for CRC cell growth, providing a novel alternative to target therapies of CRC. Further research on this topic is warranted.

Microvesicles Derived from Inflammation-Challenged Endothelial Cells Modulate Vascular Smooth Muscle Cell Functions.

Purpose: Microvesicles (MV) can modulate the function of recipient cells by transferring their contents. Our previous study highlighted that MV released from tumor necrosis factor-α (TNF-α) plus serum deprivation (SD)-stimulated endothelial progenitor cells, induce detrimental effects on endothelial cells. In this study, we investigated the potential effects of endothelial MV (EMV) on proliferation, migration, and apoptosis of human brain vascular smooth cells (HBVSMC).Methods: EMV were prepared from human brain microvascular endothelial cells (HBMEC) cultured in a TNF-α plus SD medium. RNase-EMV were made by treating EMV with RNase A for RNA depletion. The proliferation, apoptosis and migration abilities of HBVSMC were determined after co-culture with EMV or RNase-EMV. The Mek1/2 inhibitor, PD0325901, was used for pathway analysis. Western blot was used for analyzing the proteins of Mek1/2, Erk1/2, phosphorylation Erk1/2, activated caspase-3 and Bcl-2. The level of miR-146a-5p was measured by qRT-PCR.Results: (1) EMV significantly promoted the proliferation and migration of HBVSMC. The effects were accompanied by an increase in Mek1/2 and p-Erk1/2, which could be abolished by PD0325901; (2) EMV decreased the apoptotic rate of HBVSMC by approximately 35%, which was accompanied by cleaved caspase-3 down-regulation and Bcl-2 up-regulation; (3) EMV increased miR-146a-5p level in HBVSMC by about 2-folds; (4) RNase-treated EMV were less effective than EMV on HBVSMC activities and miR-146a-5p expression.Conclusion: EMV generated under inflammation challenge can modulate HBVSMC function and fate via their carried RNA. This is associated with activation of theMek1/2/Erk1/2 pathway and caspase-3/Bcl-2 regulation, during which miR-146a-5p may play an important role. The data suggest that EMV derived from inflammation-challenged endothelial cells are detrimental to HBVSMC homeostatic functions, highlighting potential novel therapeutic targets for vascular diseases.

Acyl-CoA Synthetase 5 Promotes the Growth and Invasion of Colorectal Cancer Cells.

Background and Aims Acyl-CoA synthetase 5 (ACS5) has been reported to be associated with the development of various cancers, but the role of it in colorectal cancer (CRC) is not well understood. The present study aimed to explore the potential role of ACS5 in the development and progression of CRC. Methods ACS5 expression in CRC tissues and CRC cell lines was examined, and its clinical significance was analyzed. The role of ACS5 in cell proliferation, apoptosis, and invasion was examined in vitro. Results We found that ACS5 expression was upregulated in CRC cells and CRC tissues and that high ACS5 expression was more frequent in CRC patients with excess muscular layer and with poor tumor differentiation. Furthermore, knockdown of ACS5 in HT29 and SW480 cells significantly dampened cell proliferation, induced cell apoptosis, and reduced cell migration and invasion. In contrast, the ectopic overexpression of ACS5 in LOVO and SW620 cells remarkably promoted cell proliferation, inhibited cell apoptosis, and enhanced cell migration and invasion. Enhanced cell growth and invasion ability mediated by the gain of ACS5 expression were associated with downregulation of caspase-3 and E-cadherin and upregulation of survivin and CD44. Conclusions Our data demonstrate that ACS5 can promote the growth and invasion of CRC cells and provide a potential target for CRC gene therapy.

Protective Effects of Curcumin on Manganese-Induced BV-2 Microglial Cell Death.

Curcumin, a bioactive component in tumeric, has been shown to exert antioxidant, anti-inflammatory, anticarcinogenic, hepatoprotective, and neuroprotective effects, but the effects of curcumin against manganese (Mn)-mediated neurotoxicity have not been studied. This study examined the protective effects of curcumin on Mn-induced cytotoxicity in BV-2 microglial cells. Curcumin (0.1-10 µM) dose-dependently prevented Mn (250 µM)-induced cell death. Mn-induced mitochondria-related apoptotic characteristics, such as caspase-3 and -9 activation, cytochrome c release, Bax increase, and Bcl-2 decrease, were significantly suppressed by curcumin. In addition, curcumin significantly increased intracellular glutathione (GSH) and moderately potentiated superoxide dismutase (SOD), both which were diminished by Mn treatment. Curcumin pretreatment effectively suppressed Mn-induced upregulation of malondialdehyde (MDA), total reactive oxygen species (ROS). Moreover, curcumin markedly inhibited the Mn-induced mitochondrial membrane potential (MMP) loss. Furthermore, curcumin was able to induce heme oxygenase (HO)-1 expression. Curcumin-mediated inhibition of ROS, down-regulation of caspases, restoration of MMP, and recovery of cell viability were partially reversed by HO-1 inhibitor (SnPP). These results suggest the first evidence that curcumin can prevent Mn-induced microglial cell death through the induction of HO-1 and regulation of oxidative stress, mitochondrial dysfunction, and apoptotic events.

Topical Application of Adipose Tissue-Derived Mesenchymal Stem Cells Ameliorates Renal Ischemia-Reperfusion Injury in Rats

Ischemia-Reperfusion Injury (IRI) was induced by clamping bilateral renal pedicles simultaneously for 60-min using bulldog clamps in Sprague-Dawley rats. They were then randomized into five groups: Group-I-3 × 106 MSCs were topically applied to the surface of each kidney with a layer of fibrin sealant, Group-II-only fibrin sealant was added, Group-III-only 3 × 106 MSCs were added, Group-IV-1 × 106 MSCs were injected directly into tail-vein and Group-V received no additional treatment (control). Serum creatinine in Group-I at Day-3 was significantly lower than the other groups. By Day-7, survival rates of animals with renal IRI were 81.3% in Group-I, 31.3% in Group-II, 37.6% in Group-III, 30.8% in Group-IV, and 25% in Group-V. At Day-3, histology of kidneys from Group-I showed less tubular necrosis and interstitial inflammation, when compared to Group-V. Reverse transcription polymerase chain reaction showed down-regulation of caspase-3 (indicator of apoptosis) and endothelin-1 (indicator of endothelial damage) and up-regulation of NQO-1 (antioxidative molecule) (p<0.05). A total of 4168 unique genes of the topical MSCs growing on the surface of ischemic kidneys were differentially regulated with reference to the MSC pellet (greater than twofold change; p<0.05). In conclusion, application of topical MSCs with fibrin sealant could improve outcomes of renal IRI ischemia in rats.

Azithromycin ameliorates airway remodeling via inhibiting airway epithelium apoptosis

AimsAzithromycin can benefit treating allergic airway inflammation and remodeling. In the present study, we hypothesized that azithromycin alleviated airway epithelium injury through inhibiting airway epithelium apoptosis via down regulation of caspase-3 and Bax/Bcl2 ratio in vivo and in vitro. Main methodsOvalbumin induced rat asthma model and TGF-β1-induced BEAS-2B cell apoptosis model were established, respectively. In vivo experiments, airway epithelium was stained with hematoxylin and eosin (HE) and periodic acid–Schiff (PAS) to histologically evaluate the airway inflammation and remodeling. Airway epithelium apoptotic index (AI) was further analyzed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), while expression of apoptosis related gene (Bax, Bcl2, Caspase-3) in lungs were measured by qRT-PCR and western blotting, respectively. In vitro experiments, apoptosis were evaluated by Flow cytometry (FCM) and TUNEL. Above apoptosis related gene were also measured by qRT-PCR and western blotting. Key findingsCompared with the OVA group, azithromycin significantly reduced the inflammation score, peribronchial smooth muscle layer thickness, epithelial thickening and goblet cell metaplasia (P<0.05), and effectively suppressed AI of airway epithelium (P<0.05). Moreover, the increasing mRNA and protein expressions of Caspase-3 and Bax/Bcl-2 ratio in lung tissue were all significantly decreased in azithromycin-treated rats (P<0.05). In vitro, azithromycin significantly suppressed TGF-β1-induced BEAS-2B cells apoptosis (P<0.05) and reversed TGF-β1 elevated Caspase-3 mRNA level and Bax/Bcl-2 ratio (P<0.05). SignificanceAzithromycin is an attractive treatment option for reducing airway epithelial cell apoptosis by improving the imbalance of Bax/Bcl-2 ratio and inhibiting Caspase-3 level in airway epithelium.

Effects and Mechanisms of Metformin on the Proliferation of Esophageal Cancer Cells In Vitro and In Vivo.

PurposeThe purpose of this study was to observe the effects of metformin on human esophageal cancer cell and to investigate its possible mechanisms.Materials and MethodsCell viability was detected by using a Cell Counting Kit-8, while cell cycle and apoptosis were assessed by flow cytometry and western blot was used to measure the expression of the related proteins. RNAi was used to knockout pyruvate kinase muscle isozyme 2 (PKM2). An Eca109 tumor model was established to evaluate the antitumor effect in vivo. Immunohistochemistry was determined based on the expression of PKM2 and Bim in tumor tissues. Tunnel was used to assess tumor cell apoptosis.ResultsEsophageal cancer cells viability was reduced after metformin treatment. The cell cycle was arrested in the G0/G1 phase, apoptosis was induced, caspase 3 was activated, caspase 9 was downregulated, and the pro-apoptotic protein Bim increased. Further study revealed that metformin could suppress the expression of insulin-like growth factor 1 receptor and its downstream proteins, phosphoinositide 3-kinase (PI3K), protein kinase B (AKT/PKB), phosphorylation of AKT (pAKT), mammalian target of rapamycin (mTOR), p70S6K, and PKM2. Insulin-like growth factor 1 partly reversed metfromin-induced apoptosis and attenuated the repression effect of metfomin to PI3K, pAKT, and PKM2. Knockout PKM2 resulted in the activation of caspase 3, down-regulation of caspase 9, and increased expression of Bim. In the Eca109 xenograft model, metformin significantly reduced tumor growth. Furthermore, we found that metformin treatment increased the rate of apoptosis, down-regulation of PKM2, and up-regulation of Bim in tumor tissues.ConclusionMetformin restrained esophageal cancer cell proliferation partly by suppressing the PI3K/AKT/mTOR pathway.

Atorvastatin Pretreatment Inhibits Myocardial Inflammation and Apoptosis in Swine After Coronary Microembolization.

In addition to its cholesterol-lowering effect, atorvastatin (ATV) has been thought to have multiple cardiovascular benefits, including anti-inflammatory and anti-apoptotic properties. The present study was undertaken to determine whether ATV pretreatment could attenuate myocardial apoptosis and inflammation and improve cardiac function in a swine model of coronary microembolization (CME). Twenty-four swine were randomly and equally divided into a sham-operated (control) group, CME group, and CME plus ATV group. Swine CME was induced by intracoronary injection of inert plastic microspheres (diameter 42 μm) into the left anterior descending coronary, with or without pretreatment of ATV. Echocardiographic measurements, a pathological examination, terminal deoxynucleotidyl transferase-mediated nick end labeling staining, and Western blotting were performed to assess the functional, morphological, and molecular effects in CME. The expression levels of caspase 3 and tumor necrosis factor-α (TNF-α) were aberrantly upregulated in cardiomyocytes following CME. Downregulation of caspase 3 and TNF-α with ATV pretreatment was associated with improved cardiac function and attenuated serum cardiac troponin I (cTnI) and high-sensitivity C-reactive protein. In addition, through a Pearson correlation analysis, the left ventricular ejection fraction negatively correlated with caspase 3, TNF-α, and cTnI. This study demonstrated that ATV pretreatment could significantly inhibit CME-induced myocardial apoptosis and inflammation and improve cardiac function. The data generated from this study provide a rationale for the development of myocardial apoptosis and inflammation-based therapeutic strategies for CME-induced myocardial injury.

Polypeptides from the Skin of Rana chensinensis Exert the Antioxidant and Antiapoptotic Activities on HaCaT Cells

ABSTRACTStudies have shown that frog skin secretes many types of peptides that are good for human skin. In this study, acid and enzymatic extracts of Rana skin peptides (acid/enzymatic Rana skin peptides, ARPs/ERPs) were obtained. The chemical and physical properties of the ARPs and ERPs were identified through UV scanning, HGLC, FRIT, and MS. MTS and flow cytometry were used to test the proproliferative and antiapoptotic effects of the ARPs and ERPs on human immortalized keratinocytes (HaCaT cells). To elucidate the antiapoptotic mechanisms, the mRNA and protein levels of EGF (epidermal growth factor, which enhances stimulation of cellular proliferation in both cells and epithelial tissues) and caspase-3 were evaluated using quantitative RT-PCR. The results indicated that the ARPs and ERPs were extracted from the Rana skin with yields of 0.65% and 0.52%, respectively. Treatment with ARPs (1.6 g/L) and ERPs (0.8 g/L) showed a 1.66-fold (p < 0.001) and 2.1-fold (p < 0.001) enhancement in the proliferation rates of HaCaT cells. The rate of apoptosis decreased by 2.6 fold (p < 0.01) and 3.4 fold (p < 0.01) under the UVB stimulation, respectively, at the same time, the up-regulation of EGF and down-regulation of caspase-3 were found. These results suggested that we can dig into the potential value of ARPs/ERPs in a new field.