Loss Of Mitochondrial Transmembrane Potential Research Articles

Apoptotic activity of xanthoquinodin JBIR-99, from Parengyodontium album MEXU 30054, in PC-3 human prostate cancer cells

Natural products are a valuable source of anticancer agents, with many naturally derived compounds currently used in clinical and preclinical treatments. This study aims to investigate the antiproliferative activity and potential mechanism of action of the xanthoquinodin JBIR-99, isolated from fungi Parengyodontium album MEXU 30,054 and identified by single-crystal X-ray crystallography. Cytotoxicity of xanthoquinodin was evaluated in a panel of human cancer cells lines and CCD-112-CoN normal colon cells, using the sulforhodamine B assay. PC-3 prostate cancer cells were used in biochemical assays including cell cycle, mitochondrial transmembrane potential (MTP), reactive oxygen species (ROS) and caspase activity. Expression levels of apoptosis-pathway-related proteins were analyzed by Western blot. The in vivo toxicity of xanthoquinodin was determined using a zebrafish model. Xanthoquinodin showed cytotoxicity in all cancer cell lines but demonstrated relative selective potency against PC-3 cells with an IC50 1.7 μM. In CCD-112-CoN cells, xanthoquinodin was non-cytotoxic at 100 μM. In PC-3 cells, the compound induced loss of MTP, production of ROS, and cell cycle arrest in S phase. The expression and activity of caspase-3 was increased, which correlates with the upregulation of Cyt c, Bax, nuclear factor kappa-B (NF-κB) (p65) and IKKβ, and downregulation of poly ADP ribose polymerase (PARP-1) and Bcl-2. Lastly, xanthoquinodin did not cause any visible developmental toxicity in zebrafish at 50 μM. These results demonstrate xanthoquinodin induces apoptosis in PC-3 prostate cancer cells by activation of both intrinsic and extrinsic apoptotic pathways. In addition, the non-toxic effect in vivo indicates that xanthoquinodin could be a useful lead in the development of a novel, anti-cancer agent that is selective for prostate cancer.

Ruthenium(II) complexes with 6-methyl-2-thiouracil selectively reduce cell proliferation, cause DNA double-strand break and trigger caspase-mediated apoptosis through JNK/p38 pathways in human acute promyelocytic leukemia cells

Ruthenium(II) complexes with 6-methyl-2-thiouracil cis-[Ru(6m2tu)2(PPh3)2] (1) and [Ru(6m2tu)2(dppb)] (2) (where PPh3 = triphenylphosphine; dppb = 1,4-bis(diphenylphosphino)butane; and 6m2tu = 6-methyl-2-thiouracil) are potent cytotoxic agents and able to bind DNA. The aim of this study was to evaluate in vitro cellular underlying mechanism and in vivo effectiveness of these ruthenium(II) complexes in human acute promyelocytic leukemia HL-60 cells. Both complexes displayed potent and selective cytotoxicity in myeloid leukemia cell lines, and were detected into HL-60 cells. Reduction of the cell proliferation and augmented phosphatidylserine externalization, caspase-3, -8 and -9 activation and loss of mitochondrial transmembrane potential were observed in HL-60 cells treated with both complexes. Cotreatment with Z-VAD(OMe)-FMK, a pan-caspase inhibitor, reduced Ru(II) complexes-induced apoptosis. In addition, both metal complexes induced phosphorylation of histone H2AX (S139), JNK2 (T183/Y185) and p38α (T180/Y182), and cotreatment with JNK/SAPK and p38 MAPK inhibitors reduced complexes-induced apoptosis, indicating DNA double-strand break and activation of caspase-mediated apoptosis through JNK/p38 pathways. Complex 1 also reduced HL-60 cell growth in xenograft model. Overall, the outcome indicated the ruthenium(II) complexes with 6-methyl-2-thiouracil as a novel promising antileukemic drug candidates.

Di (2-ethylhexyl) phthalate induces cytotoxicity in HEK-293 cell line, implication of the Nrf-2/HO-1 antioxidant pathway.

The di (2-ethylhexyl) phthalate (DEHP) is a plasticizer used in the polyvinyl chloride industry. Human exposure to this plasticizer is inevitable and contributes to several side effects. In this study, we examined whether DEHP induces apoptosis and oxidative stress in embryonic kidney cells (HEK-293) and whether the nuclear factor E2-related factor 2 (Nrf-2)/heme oxygenase-1 (HO-1) antioxidant pathway is involved in the pathogenesis of this process. We demonstrated that DEHP is cytotoxic to HEK-293 cells. It causes oxidative damage through the generation of free radicals, induces lipid peroxidation, and alters superoxide dismutase and catalase activities. Simultaneously, DEHP treatment decreases the expression and the protein level of Nrf-2 and HO-1. Inhibition of the Nrf-2/HO-1 pathway is related to the mitochondrial pathway of apoptosis. This apoptotic process is characterized by a loss of mitochondrial transmembrane potential (ΔΨm) and upregulation of the expression of caspase-3 mRNA as well as its protein level.

ER alpha selective chromone, isoxazolylchromones, induces ROS-mediated cell death without autophagy.

Chromones are recognized as privileged structures and useful templates for the design of novel compounds with promising pharmacological activity. Several reports implicate chromone scaffold as an antitumor agent. The present study highlights synthesis, docking, and potential activity of isoxazolylchromones, 3(a-f), a new class of compounds as potential agents exhibiting ERα antagonism and ERβ agonism. Molecular docking studies determined the binding site of compounds 3(a-f) in ERα and ERβ. All the analogues synthesized showed preferential cytotoxicity in ERα+ cell line (MCF-7) compared to ERα- cell line (MDA-MB-231). Among the analogues synthesized, analogue 3d exhibited increased cytotoxicity. ERα silencing experiments confirmed the ERα selective nature of ligands. Transactivation assay on compound 3d indicated the down-regulation of ERα luciferase reporter gene expression and induction of ERβ GFP in the treated cells. Cell cycle analysis revealed an increase in sub-G0/G1 population on treatment with analogue 3d as compared to control. Similar to tamoxifen, 3d-induced cell death is mediated through an increase in ROS as evidenced by change in roGFP ratio. Interestingly, the compound 3d induced mitochondrial trans-membrane potential loss and caspase activation without indication of autophagy compared to tamoxifen that induced autophagy in the treated cells. Lack of significant autophagy and induction of ERβ signaling by the new compound place them as a better ERα antagonist.

Characterization of the cellular effects of myeloperoxidase-derived oxidants on H9c2 cardiac myoblasts

Oxidative stress is a major hallmark of cardiac ischemia/reperfusion (I/R) injury, which is in part due to the release of the enzyme myeloperoxidase (MPO) from activated infiltrating leukocytes, and the subsequent production of the oxidants hypochlorous acid (HOCl) and hypothiocyanous acid (HOSCN). Although exposure of various cell types to either oxidant is known to cause cellular dysfunction within a variety of pathological settings, the precise role of HOCl and HOSCN in the initiation of tissue damage evident following cardiac I/R injury remains unclear. In this study, we have employed the use of the cardiac myoblast cell line H9c2 as a model for cardiac myocytes and demonstrate that exposure to either oxidant elicits a dose-dependent increase in cytosolic calcium accumulation, depletion of the cellular thiol pool, reduction of glutathione (GSH) levels and loss of mitochondrial inner trans-membrane potential, concomitant with increased necrotic cell death. H9c2 cell recovery from the initial oxidant exposure involves the initiation of cell survival signalling pathways centred around Nrf2-antioxidant response element (ARE) and activator protein 1 (AP-1) activation, with cell survival accompanied by restoration of mitochondrial function following exposure to HOSCN, but not HOCl. These data highlight the cellular responses elicited by HOCl and HOSCN in cardiac myocytes furthering our understanding of the pathogenesis of oxidant injury following cardiac I/R injury.

Glucocorticoid induces osteonecrosis of the femoral head in rats through GSK3β-mediated osteoblast apoptosis

ObjectiveOne of the important causes of glucocorticoids (GCs)-induced osteonecrosis of the femoral head (ONFH) is osteoblast apoptosis. Glycogen synthase kinase 3β (GSK3β) has been reported to be related to dexamethasone (Dex)-induced osteoblast apoptosis. This study aimed to determine whether GSK3β plays role in GC-induced ONFH and investigate the underlying mechanism. Methods18 male Sprague-Dawley rats were divided into 3 groups. Rats from ONFH group underwent lipopolysaccharide and methylprednisolone injection. Lithium chloride (LiCl, a GSK3β inhibitor) group were fed with LiCl solution. The control group were untreated. Osteonecrosis, apoptosis and bone loss were evaluated by HE staining, TUNEL staining and micro-CT respectively. Protein expressions were examined by western blotting. In addition, primary osteoblast cells were transfected by GSK3β-siRNA and related signaling pathway and proteins were examined. ResultsONFH group showed a relative high percentage of empty lacunae and apoptotic cells, whilst LiCl treatment markedly decreased the percentage. LiCl treatment decreased GC-induced bone loss. Immunoblot analysis for GSK3β showed decreased level of Ser9-phosphorylated GSK3β in ONFH group compared with control group. Knockdown of GSK3β by siRNA in primary osteoblast cells attenuated DEX-induced apoptosis and loss of mitochondrial transmembrane potential (Δψm). GSK3β knockdown also reversed the release of cytochrome C (Cyt C) from mitochondria to the cytosol. GSK3β decreased apoptosis-related protein expression both in vitro and in vivo. ConclusionOur findings suggest that GC induces ONFH in rats through GSK3β-mediated osteoblast apoptosis, with involvement of mitochondrial apoptotic pathway.

Antitumor activity in colorectal cancer induced by hinokiflavone.

Colorectal cancer is one of the most common malignant disease worldwide with highly metastatic potential. Identification of effective therapeutic treatment overcoming such disease is an urgent need. Our study focuses on hinokiflavone as an antitumor agent against colorectal cancer. MTT assay, cell colony formation assay, Hoechst staining, flow cytometry, Western blot analysis, real-time polymerase chain reaction, and migration and invasion assay were performed to identify the effects of hinokiflavone on cell proliferation, apoptosis, and metastasis. CT26 tumor-bearing mice model was conducted to explore the antitumor activity of hinokiflavone in vivo. Immunohistochemistry staining was used to detect the protein expression of Ki-67, cleaved caspase-3, and MMP9 in treated tumors. Acute toxicity was evaluated by serological and hematological analyses, and drug side effect on organs was evaluated by hematoxylin and eosin staining. Hinokiflavone reduced the proliferation, migration, and invasion and promoted the apoptosis in colorectal tumor cells in vitro. Treatment of hinokiflavone at a tolerable and safe dose (50mg/kg) significantly suppressed tumor growth in mice bearing CT26 tumors by reducing tumor proliferation and metastasis and inducing apoptosis. Mechanically, treatment of hinokiflavone induced apoptosis by loss of mitochondrial transmembrane potential and increased reactive oxygen species generation. Hinokiflavone suppressed colorectal tumor cell proliferation, induced apoptosis via the reactive oxygen species-mitochondria-mediated apoptotic pathway, and inhibited tumor cell migration and invasion. Antitumor activity of hinokiflavone was also validated in mice model without observed toxicity. Our findings suggested that the plant-derived hinokiflavone could be used as an antitumor agent against colorectal cancer.

Design, graph theoretical analysis and bioinformatic studies of proanthocyanidins encapsulated ethyl cellulose nanoparticles for effective anticancer activity

Phytoconstituent’s has significant antioxidant and anticancer activity against various types of cancer cells. But these water soluble phytoconstituent’s has poor absorption due to their huge molecular size as well as it cannot be reach at the targeted disease site, thus targeted drug delivery system is one of the effective approaches to enhancing the bioavailability and decreasing drug toxicity. To achieve this target, the Proanthocyanidins (Pro) and ethyl cellulose (EC) was used to formulate nanoparticles (NPs) for effective drug delivery system. The Pro encapsulated ECNPs were formulated by simple anti-solvent particle induction method and its physico-chemical characteristics were examined by FTIR, XRD, Zeta size analyzer, SEM, and TEM. The graph theoretical network analysis was implemented to identify the drug target and subsequently molecular docking studies were screened. The identified target using graph theoretical analysis and molecular docking study reported strong interaction of Pro encapsulated ECNPs in binding pockets of MAPK. The formulated ECNPs has been very effective in arresting the proliferation of colon cancer (HT-29) cells with an IC50 value of 33.4 μg ml−1 after 24 h treatment. Further, HT-29 cells exposure with Pro encapsulated ECNPs resulted in typical apoptotic through necrotic cellular morphology, loss of mitochondrial transmembrane potential, and high ROS generation were also observed. The observed results highlight that EC as a potential carrier material for enhancing the bioavailability of anti-cancer drugs.

Mitochondrial division inhibitor-1 potentiates cisplatin-induced apoptosis via the mitochondrial death pathway in cholangiocarcinoma cells

AimsMdivi-1, a selective Drp-1 inhibitor, impedes mitochondrial dynamics and suppresses cancer proliferation and progression. Cholangiocarcinoma (CCA) is a very aggressive malignancy which is refractory to chemotherapy. The study investigated the mechanism of the chemosensitizing effect of mdivi-1 in cholangiocarcinoma. Main methodsCCA cells and HEK293 T cells were employed in the study. Cell viability and induction of apoptotic cell death were determined by the MTT and acridine orange-ethidium bromide methods. Cellular glutathione content and reactive oxygen species (ROS) formation were assessed using thiol green and 2′,7′-dichlorofluorescin diacetate fluorescent probes, respectively. Mitochondrial transmembrane potential and autophagy were detected by JC-1 dye and autophagy assay. Cell cycle progression was analyzed by flow cytometry. Cell migration was measured using the wound healing assay. Proteins involved in cell proliferation and cell cycle were analyzed by western immunoblotting. Key findingsMdivi-1 enhanced cisplatin-induced cytotoxicity in CCA cells but not in HEK293 T cells. Mdivi-1 enhanced cisplatin induced glutathione redox stress, ROS formation, and loss of mitochondrial transmembrane potential. Moreover, mdivi-1 also inhibited autophagic flux and suppressed CCA cell migration. SignificanceMdivi-1 sensitized CCA cells to cytotoxicity of cisplatin in association with increases of oxidative stress and autophagosomes, and induced cell death via the mitochondrial pathway. Disruption of mitochondrial dynamics may be a novel strategy to improve the efficacy of chemotherapy to treat CCA.

Cigarette smoke induces ROS mediated autophagy impairment in human corneal epithelial cells

Cigarette smoke is an important indoor air pollutant which has deleterious effects on human health. Continued daily exposure to cigarette smoke has been attributed to the risk factor of ocular surface diseases. However, the mechanisms underlying the ocular surface damage are not fully elucidated. In this study, exposure to cigarette smoke extract (CSE) induced a dose- and time-dependent cytotoxicity in human corneal epithelial (HCE) cells, supported by the observation of reduced cell viability, increased apoptotic cells, elevated intracellular oxidative stress and loss of mitochondrial transmembrane potential. In addition, CSE exposure led to the impairment of proteostasis and autophagy, which resulted in the accumulation of ubiquitinated proteins as aggregates in peri-nuclear spaces. Furthermore, the autophagy inducer, cysteamine was shown to attenuate the CSE induced cell damage, oxidative stress and mitochondrial dysfunction in HCE cells. Moreover, cysteamine inhibited the formation of ubiquitin-positive aggregates around the peri-nuclear region, through regulating the autophagic activity of HCE cells. Similar to in vitro experiments, cigarette smoke induced proteostasis and autophagy impairment in corneal epithelial cells could be rescued by cysteamine in a cigarette smoke-exposed murine model. Therefore, this study may provide first evidence that dysfunction of autophagy contributes to the pathogenesis of ocular surface diseases associated with cigarette smoke exposure. Besides, it also suggests the potential therapeutic value of cysteamine in the prevention and treatment of cigarette smoke induced ocular surface injury.CSE induces cytotoxicity and accumulation of ubiquitinated proteins in HCE cells due to impairment of proteostasis and autophagy, which can be rescued by cysteamine.

Zearalenone causes embryotoxicity and induces oxidative stress and apoptosis in differentiated human embryonic stem cells

In this study, murine embryonic stem cell test (mEST) and human embryonic stem cell test (hEST) models were developed to evaluate the embryonic toxicity of Zearalenone (ZEN) according to the methods established in our laboratory. The embryotoxicity of ZEN was described by comparing the three functions calculated based on three endpoints, that is, 50% inhibitory proliferation concentration (IC50) of embryonic stem cells (ESCs) and 3T3 cells and 50% inhibition of cardiomyocyte differentiation (ID50) of ESCs determined in the EST model. Moreover, differentiation of human embryonic stem cell (hESC) was initiated by embryoid bodies (EBs) formation; EBs were exposed to different concentrations of ZEN for 24 h to detect cellular reactive oxygen species (ROS) generation, the mitochondrial transmembrane potential (MMP), apoptosis, cell cycle, and the related protein expression. Based on the results of the three endpoints and functions of ZEN in mEST and hEST, ZEN was evaluated to have strong embryonic toxicity both by two models. The increases in cellular ROS and loss of MMP were observed at 2 and 4 μg/ml concentrations. Flow cytometry showed that ZEN induced cell cycle arrest and apoptosis. The upregulation of p53, caspase-9, caspase-3, and the ratio of Bax/Bcl-2 were observed at 2 and 4 μg/ml concentrations. Collectively these results demonstrate that ZEN has strong embryonic toxicity and induces oxidative stress and apoptosis in differentiated human ESCs.

Zeylenone Induces Mitochondrial Apoptosis and Inhibits Migration and Invasion in Gastric Cancer.

The mortality of gastric cancer (GC) is increasing due to its high rates of recurrence and metastasis. Zeylenone (Zey), a type of naturally occurring cyclohexene oxide, was demonstrated to be effective in cancer patients. The aim of this study is to explore the anti-cancer effect of Zey against gastric cancer both in vitro and in vivo, as well as the underlying mechanisms. We found that Zey inhibited gastric tumor growth, as demonstrated by in vitro gastric cancer cell lines and in a human gastric cancer xenograft mouse model. Furthermore, Zey induced substantial apoptosis through a mitochondrial apoptotic pathway, involving mitochondrial transmembrane potential loss, caspase-3 activation, anti-apoptotic protein downregulation, and pro-apoptotic protein upregulation. Notably, we revealed for the first time that Zey suppressed invasion and migration by wound healing and transwell chamber assays. Through Western blotting, we further explored the potential mechanism of Zey’s anti-cancer activity. We found that Zey downregulated the expression of matrix metalloproteinase 2/9 (MMP 2/9) and inhibited the phosphorylation of AKT and ERK. In short, Zey, which induced mitochondrial apoptosis and inhibited proliferation, migration, and invasion, may be developed as a novel drug for the treatment of gastric cancer.

Histone deacetylase 8 protects human proximal tubular epithelial cells from hypoxia-mimetic cobalt- and hypoxia/reoxygenation-induced mitochondrial fission and cytotoxicity

Cell death by hypoxia followed by reoxygenation (H/R) is responsible for tissue injury in multiple pathological conditions. Recent studies found that epigenetic reprogramming mediated by histone deacetylases (HDACs) is implicated in H/R-induced cell death. However, among 18 different isoforms comprising 4 classes (I-IV), the role of each HDAC in cell death is largely unknown. This study examined the role of HDAC8, which is the most distinct isoform of class I, in the hypoxia mimetic cobalt- and H/R-induced cytotoxicity of human proximal tubular HK-2 cells. Using the HDAC8-specific activator TM-2-51 (TM) and inhibitor PCI34051, we found that HDAC8 played a protective role in cytotoxicity. TM or overexpression of wild-type HDAC8, but not a deacetylase-defective HDAC8 mutant, prevented mitochondrial fission, loss of mitochondrial transmembrane potential and release of cytochrome C into the cytoplasm. TM suppressed expression of dynamin-related protein 1 (DRP1) which is a key factor required for mitochondrial fission. Suppression of DRP1 by HDAC8 was likely mediated by decreasing the level of acetylated histone H3 lysine 27 (a hallmark of active promoters) at the DRP1 promoter. Collectively, this study shows that HDAC8 inhibits cytotoxicity induced by cobalt and H/R, in part, through suppressing DRP1 expression and mitochondrial fission.

Mancozeb selectively induces mitochondrial-mediated apoptosis in human gastric carcinoma cells through ROS generation

Mancozeb (Manganese ethylene bis-dithiocarbamate with zinc salt) is a dithiocarbamate fungicide used to control fungal disease in many fruit plants, flowers and the maintenance of field crops. The effect of mancozeb on cell viability of human gastric adenocarcinoma AGS, SNU-1 cells and human normal FHs 74 Int cells were investigated. This study demonstrated that mancozeb was able to inhibit cell proliferation by 56–82% at 5–10 μM concentrations after 48 h. Mancozeb treatment for 48 h resulted in 33% (P < 0.05) and 61% (P < 0.001) increase in apoptotic cells at 5 and 10 μM concentrations in AGS cells, respectively. Treatment with mancozeb did not cause cell cycle arrest, while modulated the expression level of cleaved caspase-3, and cleavage of poly-(ADP-ribose) polymerase. Furthermore, treatment with mancozeb caused a rapid stimulation of reactive oxygen species (ROS) and loss of mitochondrial transmembrane potential. The results also showed that mancozeb-induced apoptosis was accompanied by up-regulation of Bax and down-regulation of Bcl-2 and Bcl-xL. Overall, our data suggested that mancozeb caused ROS generation which induced significant (P < 0.05) apoptosis in AGS cells that was attenuated with pretreatment of NAC. More importantly, same concentration of mancozeb did not show any considerable effect on cell growth, death, cell cycle arrest and ROS generation in normal FHs 74 Int cells. Overall, for the first time these results suggest that mancozeb has selective anticancer activity at lower concentrations against gastric cancer cells.

Cellular responses of normal (HL-7702) and cancerous (HepG2) hepatic cells to dust extract exposure

Cancerous human liver cell line has been used to test the hepatic toxicity of indoor dust, showing its organic extract decreases cell viability. However, little is known about its impact on normal human liver cell line. In the present study, we compared the cellular responses between carcinoma cell line (HepG2) and normal cell line (HL-7702) after exposing to 10–640 μg/100 μL organic dust extract for 24 h. The dust extract caused cytotoxicity, oxidative damage, inflammatory response and loss of mitochondrial transmembrane potential (MMP) in both cells. The inhibition of cell viability in HL-7702 cells was stronger than that in HepG2 cells, with HL-7702 cells having lower LC50. Higher production of oxidative stress, more loss of MMP and stronger suppression of antioxidant enzymes mRNA level occurred in HepG2 cells, while mRNA expression and hepcidin secretion were enhanced in HL-7702 cells at 40/100 μL, indicating the dust extract probably perturbed their liver Fe homeostasis. Our data showed considerable differences in cellular responses between normal and cancerous cell lines. To obtain accurate data, normal hepatocytes should be employed as they better match with the in vivo tissue than cancerous cell lines.

Antitumor activity of Lepidium latifolium and identification of the epithionitrile 1-cyano-2,3-epithiopropane as its major active component.

Consumption of Brassica (Cruciferae) vegetables is associated with a reduced risk of cancer, but identification of the active components and insights into the underlying molecular events are scarce. Here we found that an extract of Lepidium latifolium, a cruciferous plant native to southern Europe, Mediterranean countries and Asia, showed in vitro cytotoxic activity, inducing caspase-dependent apoptosis, in a variety of human tumor cells, and the plant juice showed in vivo antitumor activity in a HT-29 human colon cancer xenograft mouse model. The epithionitrile 1-cyano-2,3-epithiopropane (CETP) was identified as the major active cancer cell-killing principle of L. latifolium. Synthetic and plant-derived CETP displayed similar proapoptotic activities as assessed by biochemical and morphological analyses. Analysis of the antiproliferative capacity of CETP on a wide number of cancer cell lines from the NCI-60 cell line panel followed by COMPARE analysis, showed an activity profile different from known anticancer agents. Flow cytometry and biochemical analyses revealed that CETP-induced apoptosis involved mitochondria, as assessed by loss of mitochondrial transmembrane potential and generation of reactive oxygen species, while overexpression of Bcl-XL and Bcl-2 prevented CETP-induced apoptosis. Inhibition of reactive oxygen species by glutathione and N-acetyl cysteine reduced the apoptotic response induced by CETP. FADD dominant negative form, blocking Fas/CD95 signaling, and a specific caspase-8 inhibitor also inhibited CETP-induced killing. Taken together, our data suggest that the cancer cell-killing action of CETP, involving both intrinsic and extrinsic apoptotic signaling pathways, underlies the antitumor activity of L. latifolium plant, which could be of potential interest in cancer treatment.

25 - Role of selenomethionine supplementation in the modulation of damage during inflammation and myocardial ischemia/reperfusion injury

Oxidative stress is a major hallmark of cardiac ischemia/reperfusion (I/R) injury. This partly arises from the presence of activated phagocytes releasing the heme enzyme myeloperoxidase (MPO) and the associated production of hypochlorous acid (HOCl) and hypothiocyanous acid (HOSCN). The dietary supplement selenomethionine (SeMet) has been shown to both bolster endogenous antioxidant processes and readily react with MPO-derived oxidants, yet its ability to protect against cardiac I/R injury is unknown. The aim of this study was to assess whether supplementation with SeMet could modulate the extent of cellular damage observed in an in vitro cardiac myocyte model exposed to (patho)-physiological levels of HOCl and HOSCN and an in vivo rat model of cardiac I/R injury. Exposure of cardiac myocytes to HOCl resulted in a dose-dependent increase in necrotic cell death, which could be prevented by SeMet supplementation (25 µM). This was attributed to SeMet preventing the HOCl-induced loss of mitochondrial inner trans-membrane potential, and the associated cytosolic calcium accumulation, together with bolstering the activity of the selenium-dependent antioxidant enzyme glutathione peroxidase. In contrast, no apparent protection of SeMet supplementation was evident upon exposure of cells to HOSCN, where higher oxidant concentrations (100 – 125 µM) were required to induce cell death. In vivo, a significant increase in selenium levels in the plasma, brain, kidney, and heart tissue were seen in rats fed a diet supplemented with 2 mg/kg SeMet compared to controls. Echocardiograph assessment of LV function at 4 weeks post-surgical intervention in the I/R injury cohort demonstrated limited improvement in fractional shortening and ejection fraction in SeMet-supplemented fed rats compared to controls. However, a more marked improvement was observed in the sham injury cohort, indicating SeMet supplementation’s potential cardiac health benefit.

β-lactam Structured, 4-(4-(Methylsulfonyl)phenyl)-1-pentyl-3-phenoxyazetidin-2-one: Selectively Targets Cancerous B Lymphocyte Mitochondria.

β lactam-structured Cox-2 inhibitors, possesses anti-proliferative and anti-inflammatory effects. In this research, the actions of a synthetic β lactam-structured Cox-2 inhibitor with 4-(4- (Methylsulfonyl) phenyl)-1-pentyl-3-phenoxyazetidin-2-one on cellular viability of cancerous lymphoblast obtained from patients with acute lymphocytic leukemia (ALL) and normal lymphocytes obtained from healthy donors were compared. % the cell viability of cancerouslymphoblasts and normal lymphocytes treated with β lactam derivatives were assayed with MTT test. Early apoptosis and necrosis were detected by double staining of annexin V/ propidium iodide and activity of caspase 3 as the final mediator in apoptotic mode of cell death was evaluated by colorimetric assay. Our results showed that β lactam derivatives inhibited the proliferation of cancerous lymphoblast but not normal lymphocytes in a concentration-dependent mode by inducing apoptosis. Treatment with β lactam derivatives resulted in a rapid loss of mitochondrial trans-membrane potential and induction of reactive oxygen species (ROS) formation, and cytochrome c release in cytosol of mitochondria resulted in activation of procaspase-9 and formation of active apoptosome. These findings suggest that 4-(4-(Methylsulfonyl)phenyl)-1-pentyl-3-phenoxyazetidin-2-one as a β lactam could induce ROS-mediated death signaling throughmitochondrial pathway that results in apoptosis in only cancerous lymphoblast cells. The stimulationof apoptosis by β lactams may provide a pivotal mechanismfor their anticancer effect in acute lymphocytic leukemia cells.

Hedgehog signaling inhibitor GANT61 induces endoplasmic reticulum stress-mediated protective autophagy in hepatic stellate cells

Hedgehog (Hh) signaling plays an important role in the viability maintenance of hepatic stellate cells (HSC). HSCs have been identified as the major profibrogenic cells in the liver. The present study revealed that a novel Hh signaling antagonist GANT61 induced apoptosis in the activated human hepatic stellate cell line LX-2 cells, as it dose-dependently caused mitochondrial inner transmembrane potential (ΔΨm) loss and caspase-3 cleavage. Autophagic flux was markedly increased after GANT61 treatment. Moreover, we found that autophagy was a pro-survival factor in GANT61-treated LX-2 cells because autophagic inhibitors 3-Methyladenine (3-MA) or Chloroquine (CQ) significantly aggravated GANT61-induced cytotoxicity. Furthermore, the endoplasmic reticulum (ER)-resident molecular chaperone BiP, a marker of ER stress, was markedly increased after incubation with GANT61. Meanwhile, the PERK-eIF2α-ATF4-CHOP pathway was observed to be activated by GANT61. Salubrinal, a selective inhibitor of ER stress, suppressed GANT61-induced LC3BII expression and enhanced poly (ADP-ribose) polymerase (PARP) cleavage, indicating that ER stress is a trigger of autophagy and suppresses apoptosis in GANT61-treated LX-2 cells. Overall, these results demonstrate that simultaneous inhibition of Hh signaling and autophagy or ER stress could be a better way to reduce activated HSCs.

Preferential Mitochondrial Localization of a Goniothalamin Fluorescent Derivative.

A fluorescent 2,1,3-benzothiadiazole-containing goniothalamin derivative, BTD−GTN (1), has been synthesized and successfully tested in bioimaging experiments in live cells. The fluorescent compound proved to be capable of transposing the cell membranes, indicating its subcellular localization. The use of the benzothiadiazole core as the fluorophore revealed the favored localization of the GTN analogue 1 in the cytoplasm of live cells, preferentially in the mitochondria, in line with previous results that indicated the loss of mitochondrial transmembrane potential upon treatment with GTN. The results described herein highlight the potential of the BTD–GTN hybrid structures for future studies regarding the cellular mechanism of action of this family of compounds.