Annexin-A5 monomer as a membrane repair agent for the treatment of renal ischemia-reperfusion injury.

BACKGROUND: Renal ischemia-reperfusion injury (IRI) is one of the causes of acute kidney injury. Annexin A5 (AnxA5), a calcium-dependent cell membrane-binding protein, shows protective effects in various organ IRI models. This study explored the therapeutic effect of exogenous AnxA5 monomer protein on renal IRI and its potential mechanism of action. METHODS AND RESULTS: Different doses of AnxA5 were injected intravenously to treat bilateral renal IRI in SD rats. This model confirmed the protective effects of AnxA5 on kidney structure and function. In vitro, HK-2 cells were subjected to hypoxia for 12 h, followed by restoration of normal oxygen supply to simulate IRI. In vitro experiments demonstrated the mechanism of action of AnxA5 by measuring cellular activity and permeability. A comparison of the mutant AnxA5 protein M23 and the application of a calcium-free culture medium further validated the protective effect of AnxA5 by forming a network structure. CONCLUSIONS: Exogenous AnxA5 monomers prevented renal IRI by binding to the damaged renal tubular epithelial cell membrane, forming a two-dimensional network structure to maintain cell membrane integrity, and ultimately prevent cell death.

Fludioxonil induces cardiotoxicity via mitochondrial dysfunction and oxidative stress in two cardiomyocyte models.

Fludioxonil (Flu) is a phenylpyrrole fungicide and is currently used in over 900 agricultural products globally. Flu possesses endocrine-disrupting chemical-like properties and has been shown to mediate various physiological and pathological changes, such as apoptosis and differentiation, in diverse cell lines. However, the effects of Flu on cardiomyocytes have not been studied so far. The present study investigated the effects of Flu on mitochondria in AC16 human cardiomyocytes and H9c2 rat cardiomyoblasts. Flu decreased cell viability in a water-soluble tetrazolium assay and mediated morphological changes suggestive of apoptosis in AC16 and H9c2 cells. We confirmed that annexin V positive cells were increased by Flu through annexin V/propidium iodide staining. This suggests that the decrease in cell viability due to Flu may be associated with increased apoptotic changes. Flu consistently increased the expression of pro-apoptotic markers such as Bcl-2-associated X protein (Bax) and cleaved-caspase 3. Further, Flu reduced the oxygen consumption rate (OCR) in AC16 and H9c2 cells, which is associated with decreased mitochondrial membrane potential (MMP) as observed through JC-1 staining. In addition, Flu augmented the production of mitochondrial reactive oxygen species, which can trigger oxidative stress in cardiomyocytes. Taken together, these results indicate that Flu induces mitochondrial dysregulation in cardiomyocytes via the downregulation of the OCR and MMP and upregulation of the oxidative stress, consequently resulting in the apoptosis of cardiomyocytes. This study provides evidence of the risk of Flu toxicity on cardiomyocytes leading to the development of cardiovascular diseases and suggests that the use of Flu in agriculture should be done with caution and awareness of the probable health consequences of exposure to Flu.

Interleukin-18 binding protein regulates the apoptosis and necroptosis of fibroblast-like synoviocytes and chondrocytes in rheumatoid arthritis.

OBJECTIVES: Interleukin (IL)-18 plays a pro-inflammatory role in rheumatoid arthritis (RA), and its soluble inhibitor IL-18 binding protein (IL-18BP) has a potential therapeutic role. We investigated the role of IL-18BP on the joint destruction process of RA by accessing the effects of IL-18BP on fibroblast-like synoviocytes (FLSs) and chondrocytes. METHODS: Peripheral blood mononuclear cells (PBMCs) from patients with RA and healthy controls were cultured under T cell proliferative conditions with 10, 50, or 100 ng/mL of IL-18BP. After three days of culture, flow cytometry for CD4+ T cells was performed using various IL-18BP concentrations. The apoptosis and necroptosis of FLSs and chondrocytes were measured by flow cytometry using annexin V and propidium iodide (PI) and western blot under TNF-α stimulation with IL-18BP (10, 50, and 100 ng/mL). RESULTS: Differentiation of CD4+ IL-17A+ and CD4+ IL-4+ cells decreased and that of CD4+ CD25high Foxp3+ and CD4+ interferon (IFN)-γ+ cells increased on addition of IL-18BP to cultured RA patient-driven PBMCs. RA-FLS migration ability was not suppressed by IL-18BP after 12 or 24 h. IL-18BP increased annexin V+ FLS level and reduced annexin V+ chondrocyte level in a dose-dependent manner, whereas PI+ annexin V- FLS and chondrocyte levels were suppressed by 50, 100 ng/mL IL-18BP in culture. CONCLUSIONS: The administration of IL-18BP regulated the type 17 helper T cell/ regulatory T cell imbalance and attenuated the production of pro-inflammatory cytokines. IL-18BP further increased FLS apoptosis and decreased the necroptosis of FLS/chondrocytes and apoptosis of chondrocytes suggesting the joint preservative potential of IL-18BP.

Supplemental fibrinogen restores thrombus formation in cardiopulmonary bypass-induced platelet dysfunction ex vivo.

BACKGROUND: Major cardiac surgery related blood loss is associated with increased postoperative morbidity and mortality. Platelet dysfunction is believed to contribute to post-cardiopulmonary bypass (CPB)-induced microvascular bleeding. We hypothesised that moderately hypothermic CPB induces platelet dysfunction and that supplemental fibrinogen can restore in vitro thrombus formation. METHODS: Blood from 18 patients, undergoing first-time elective isolated aortic valve surgery was drawn before CPB, 30 min after initiation of CPB, and after CPB and protamine administration, respectively. Platelet aggregation was quantified by optical aggregometry, platelet activation by flow-cytometric detection of platelet surface expression of P-selectin, annexin V, and activated glycoprotein IIb/IIIa, thrombus formation under flow and effect of supplemental fibrinogen (4 mg ml-1) on in vitro thrombogenesis. RESULTS: Post-CPB adenosine-diphosphate and TRAP-6-induced aggregation decreased by 40% and 10% of pre-CPB levels, respectively (P<0.0001). Although CPB did not change glycoprotein IIb/IIIa receptor expression, it increased the percentage of unstimulated P-selectin (1.2% vs 7%, P<0.01) positive cells and annexin V mean fluorescence intensity (15.5 vs 17.2, P<0.05), but decreased percentage of stimulated P-selectin (52% vs 26%, P<0.01) positive cells and annexin V mean fluorescence intensity (508 vs 325, P<0.05). Thrombus area decreased from 6820 before CPB to 5230 after CPB (P<0.05, arbitrary units [a.u.]). Supplemental fibrinogen increased thrombus formation to 20 324 and 11 367 a.u. before CPB and after CPB, respectively (P<0.001), thereby restoring post-CPB thrombus area to levels comparable with or higher than pre-CPB baseline. CONCLUSIONS: Single valve surgery using moderately hypothermic CPB induces partial platelet dysfunction. Thrombus formation was restored in an experimental study design by ex vivo supplementation of fibrinogen.

Design, synthesis and molecular docking study of new pyrimidine-based hydrazones with selective anti-proliferative activity against MCF-7 and MDA-MB-231 human breast cancer cell lines.

Efforts were directed on the design, synthesis and evaluation of the anticancer activity of some pyrimidine-based hydrazones against two breast cancer cell lines, MCF-7 and MDA-MB-231. Preliminary screening results revealed that some candidates scrutinized for their antiproliferative activities exhibited IC50 values of 0.87 µM-12.91 µM in MCF-7 and 1.75 µM-9.46 µM in MDA-MB-231 cells, indicating almost equal activities on both cell lines and better growth inhibition activities than those of the positive control 5-fluorouracil (5-FU) which displayed IC50 values of 17.02 µM and 11.73 µM respectively. Selectivity of the significantly active compounds was estimated against MCF-10A normal breast cells when compounds 7c, 8b, 9a and 10b exhibited superior activity for cancerous cells than for normal cells when compound 10b presented the best selectivity Index (SI) with respect to both MCF-7 and MDA-MB-231 cancer cells in comparison to the reference drug 5-FU. Mechanisms of their actions were explored by inspecting activation of caspase-9, annexin V staining and cell cycle analysis. It was noticed that compounds 7c, 8b, 8c 9a-c and 10b produced an increase in caspase-9 levels in MCF-7 treated cells with 10b inducing the highest elevation (27.13 ± 0.54 ng/mL) attaining 8.26-fold when compared to control MCF-7 which was higher than that of staurosporine (19.011 ± 0.40 ng/mL). The same compounds boosted caspase-9 levels in MDA-MB-231 treated cells when an increase in caspase-9 concentration reaching 20.40 ± 0.46 ng/mL (4.11-fold increase) was observed for compound 9a. We also investigated the role of these compounds for their increasing apoptosis ability against the 2 cell lines. Compounds 7c, 8b and 10b tested on MCF-7 cells displayed pre-G1 apoptosis and arrested cell cycle in particular at the S and G1 phases. Further clarification of their effects was made by modulating their related activities as inhibitors of ARO and EGFR enzymes when 8c and 9b showed 52.4% and 58.9% inhibition activity relative to letrozole respectively and 9b and 10b showed 36% and 39% inhibition activity of erlotinib. Also, the inhibition activity was verified by docking into the chosen enzymes.

Annexin A5 suppression promotes the progression of cervical cancer.

BACKGROUND: Cervical cancer is a common malignant gynecological disease that threatens the health of women all over the world. The abnormal expression of Annexin A5 (ANXA5) is closely related to the biological behavior of various malignant tumors, however, the relationship between ANXA5 and cervical cancer is still unclear. Therefore, the effects of low expression of ANXA5 on the proliferation, apoptosis, migration and invasion of cervical cancer cells (HeLa) and its related mechanism were explored. METHODS: The cells were divided into three groups: ANXA5-si group, negative control group and blank group. RNA interference was used to suppress ANXA5 expression. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, flow cytometry and propidium iodide (PI) staining, wound healing assay and transwell assay were employed to detect cell proliferation, apoptosis, migration and invasion respectively. Meanwhile, gene expression was detected by qPCR and Western blotting. RESULTS: ANXA5 suppression lead to the increase of proliferation, migration, invasion and the decrease of apoptosis of cervical cancer HeLa cells. Furthermore, the expression of both pPI3K and pAkt increased. CONCLUSION: ANXA5 might inhibit Hela cells proliferation and metastasis by regulating PI3K/Akt signal pathway.

SHP-1 knockdown suppresses mitochondrial biogenesis and aggravates mitochondria-dependent apoptosis induced by all trans retinal through the STING/AMPK pathways.

BACKGROUND: Oxidative stress-caused damage to the retinal pigment epithelium (RPE) underlies the onset and progression of age-related macular degeneration (AMD). Impaired mitochondrial biogenesis sensitizes RPE cells to mitochondrial dysfunction, energy insufficiency and death. Src-homology 2 domain-containing phosphatase (SHP)-1 is important in regulating immune responses and cell survival. However, its roles in cell survival are not always consistent. Until now, the effects of SHP-1 on RPE dysfunction, especially mitochondrial homeostasis, remain to be elucidated. We sought to clarify the effects of SHP-1 in RPE cells in response to atRAL-induced oxidative stress and determine the regulatory mechanisms involved. METHODS: In the all trans retinal (atRAL)-induced oxidative stress model, we used the vector of lentivirus to knockdown the expression of SHP-1 in ARPE-19 cells. CCK-8 assay, Annexin V/PI staining and JC-1 staining were utilized to determine the cell viability, cell apoptosis and mitochondrial membrane potential. We also used immunoprecipitation to examine the ubiquitination modification of stimulator of interferon genes (STING) and its interaction with SHP-1. The expression levels of mitochondrial marker, proteins related to mitochondrial biogenesis, and signaling molecules involved were examined by western blotting analysis. RESULTS: We found that SHP-1 knockdown predisposed RPE cells to apoptosis, aggravated mitochondrial damage, and repressed mitochondrial biogenesis after treatment with atRAL. Immunofluoresent staining and immunoprecipitation analysis confirmed that SHP-1 interacted with the endoplasmic reticulum-resident STING and suppressed K63-linked ubiquitination and activation of STING. Inhibition of STING with the specific antagonist H151 attenuated the effects of SHP-1 knockdown on mitochondrial biogenesis and oxidative damage. The adenosine monophosphate-activated protein kinase (AMPK) pathway acted as the crucial downstream target of STING and was involved in the regulatory processes. CONCLUSIONS: These findings suggest that SHP-1 knockdown potentiates STING overactivation and represses mitochondrial biogenesis and cell survival, at least in part by blocking the AMPK pathway in RPE cells. Therefore, restoring mitochondrial health by regulating SHP-1 in RPE cells may be a potential therapeutic strategy for degenerative retinal diseases including AMD.

PPARγ activation by pioglitazone enhances the anti-proliferative effects of doxorubicin on pro-monocytic THP-1 leukemia cells via inducing apoptosis and G2/M cell cycle arrest.

PURPOSE: Doxorubicin (DOX) is a common chemotherapeutic agent, with toxic side effects, and chemoresistance. Combination chemotherapy is a successful approach to overcome these limitations. Here, we investigated the effects of pioglitazone (PGZ), a PPARγ agonist, and/or DOX on the viability, cell cycle, apoptosis on THP-1 cells and normal human monocytes (NHMs). METHODS: MTT assay was used to evaluate the cytotoxicity of DOX and/or PGZ. Cell cycle progression and apoptosis induction were examined by PI or Annexin V-PI double staining, and analyzed by flow cytometry. Quantitative RT-PCR was used to evaluate the changes in the mRNA expression of cell cycle progression or apoptosis-associated genes including P27, P21, CDK2, P53, BCL2 and FasR. RESULTS: DOX, PGZ and DOX + PGZ exerted their cytotoxic effects in a dose- and time-dependent manner with low toxicity on NHMs. The cell growth inhibitory effects of DOX were in association with G2/M arrest, while PGZ executed S phase arrest. PGZ treatment enhanced G2/M among DOX-treated combinations with moderate elevation in the S phase. DOX, PGZ and combined treatments induced apoptosis (mostly late phase) in a dose-dependent manner. All treatments resulted in the significant overexpression of p21, p27, p53 and FasR genes and downregulation of CDK2. DOX + PGZ combined treatments exhibited the most significant changes in mRNA expression. CONCLUSION: We demonstrated that the antiproliferative, cell cycle regulation and apoptosis-inducing capacity of DOX was enhanced by PGZ in THP-1 leukemia cells in a dose-dependent manner. Therefore, the combination of DOX + PGZ could be used as a novel combination to target AML.

The adhesion protein of Mycoplasma genitalium inhibits urethral epithelial cell apoptosis through CypA-CD147 activating PI3K/ Akt/NF-κB pathway.

By interacting with the receptor on the host cells membrane, Mycoplasma genitalium, a prokaryotic bacterium primarily transmitted through sexual contact, can adhere to and even enter cells. The adhesion protein of M. genitalium (MgPa) plays a critical function in the adhering and subsequent invasion into host cells. Our prior studies verified that cyclophilin A (CypA) was the receptor of MgPa on human urethral epithelial cells (SV-HUC-1) membrane and could induce pro-inflammatory cytokines production through the CypA-CD147-ERK-NF-κB pathway. This research aims to understand how MgPa interacts with its membrane receptor CypA to cause apoptosis in host cells. We employed flow cytometry to see if MgPa prevents or enhances apoptosis of SV-HUC-1 cells. The apoptosis-related proteins such as Bax, caspase-3, and cleaved caspase-3 were assayed using Western blot. Results suggested that MgPa could inhibit the apoptosis of SV-HUC-1 cells. And we demonstrated that interference with the expression of CypA or CD147 significantly reversed the inhibitory effect of MgPa on SV-HUC-1 cells apoptosis, indicating that MgPa inhibited urothelial cells apoptosis through CypA/CD147. Furthermore, we discovered that MgPa regulates the PI3K/Akt/NF-κB pathway through CypA/CD147 to inhibit SV-HUC-1 cells apoptosis. Ultimately, the inhibitory effect of MgPa on the apoptosis of the urothelial epithelial cells extracted from CypA-knockout mice was validated by Annexin V/PI assay. The results corroborated that MgPa could also inhibit mouse urothelial epithelial cells apoptosis. In summary, we demonstrated that MgPa could inhibit SV-HUC-1 cells apoptosis via regulating the PI3K/Akt/NF-κB pathway through CypA/CD147, providing experimental evidence for elucidating the survival strategies of M. genitalium in host cells. KEY POINTS: • M. genitalium protein of adhesion inhibited human urethral epithelial cells apoptosis through CypA-CD147 activating the signal pathway of PI3K/Akt/NF-κB • The knockdown of CypA and CD147 could downregulate the M. genitalium -activated PI3K/Akt/NF-κB pathway in SV-HUC-1 cells • MgPa could inhibit the apoptosis of normal C57BL mouse primary urethral epithelial cells, but not for CypA-knockout C57BL mouse primary urethral epithelial cells.

TCQA, A Natural Caffeoylquinic Acid Derivative Attenuates H2O2-Induced Neuronal Apoptosis by Suppressing Phosphorylation of MAPKs Signaling Pathway.

1,3,5-Tri-O-caffeoyl quinic acid is a caffeoylquinic acid derivative isolated from the roots of Arctium lappa L. Our previous studies have revealed that the ethyl acetate extract of the roots of A. lappa L. and the caffeoylquinic acids contained in it possess antioxidant properties, especially 1,3,5-tri-O-caffeoyl quinic acid. The present study aimed to investigate the protective effects of 1,3,5-tri-O-caffeoyl quinic acid against hydrogen peroxide-induced oxidative stress and explore the underlying mechanism. We found that 1,3,5-tri-O-caffeoyl quinic acid prevented the decline of cell viability and excessive release of lactate dehydrogenase induced by hydrogen peroxide. In addition, Hoechst 33 342 staining and Annexin V-PI double staining showed that 1,3,5-tri-O-caffeoyl quinic acid inhibited hydrogen peroxide-induced neuronal cell apoptosis. 1,3,5-Tri-O-caffeoyl quinic acid reduced the excessive production of intracellular reactive oxygen species, decreased the malondialdehyde content, and improved the activity of superoxide dismutase. Furthermore, 1,3,5-tri-O-caffeoyl quinic acid restored the loss of mitochondrial membrane potential in SH-SY5Y cells induced by hydrogen peroxide. 1,3,5-Tri-O-caffeoyl quinic acid downregulated the overexpression of proapoptotic proteins, including Bax, cytochrome c, cleaved caspase-9, and cleaved caspase-3 as well as promoted the expression of the antiapoptotic protein Bcl-2. Moreover, the phosphorylation of mitogen-activated protein kinases induced by hydrogen peroxide was inhibited by 1,3,5-tri-O-caffeoyl quinic acid. Pretreatment with 1,3,5-tri-O-caffeoyl quinic acid also promoted the activation of phosphorylated Akt. Taken together, these findings suggest that 1,3,5-tri-O-caffeoyl quinic acid exerts protective effects against hydrogen peroxide-induced neuronal apoptosis. In addition, inhibition of the mitogen-activated protein kinase signaling pathway and the activation of Akt are implicated in the antioxidant activity of 1,3,5-tri-O-caffeoyl quinic acid, giving new insight in searching for a compound with antioxidant activity for the treatment of oxidative stress-associated neurological diseases.

Anlotinib inhibits the proliferation and induces apoptosis by inactivating the AKT pathway in androgen receptor-negative prostate cancer cells.

Prostate cancer is one of the most frequently diagnosed cancers in men. The medical treatment of metastatic prostate cancer relies heavily on androgen deprivation. The present study aimed to explore the inhibitory effect of anlotinib on androgen receptor (AR)-negative prostate cancer cell lines in vitro and investigate its mechanism of action. Two prostate cancer cell lines, DU145 and PC-3, were treated with different concentrations (0-80 µM) of anlotinib. Cell proliferation was accessed by CCK-8 assay and EdU staining. Cell nuclear morphology was observed after DAPI staining, cell apoptosis level was evaluated by Annexin-V-FITC/PI staining, and western blot was used to detect the proliferation- and apoptosis-related proteins. The potential interaction between anlotinib and AKT was revealed by molecular docking. After treatment with anlotinib, the cell proliferation rate was significantly inhibited in a dose-dependent manner. The DAPI staining showed that anlotinib could induce apoptosis. Further, Annexin V/PI double staining confirmed the occurrence of apoptosis, accompanied by the increase of cleaved caspase-3 and activated PARP. Moreover, anlotinib significantly decreased the phosphorylation of protein kinase B (AKT) and its downstream pathway proteins in prostate cells (p<0.05). Experiments further confirmed that the activation of the AKT pathway reversed the inhibitory effect of anlotinib on DU145 and PC-3 cell proliferation. In addition, molecular docking analysis revealed potential interactions between anlotinib and AKT1 at multiple sites. Overall, the present study suggested that anlotinib could inhibit the proliferation and induce apoptosis in the AR-negative prostate cancer cell lines, possibly via the inactivation of the AKT pathway.

C-Phycocyanin Suppresses Cell Proliferation and Promotes Apoptosis by Regulating the AMPK Pathway in NCL-H292 Non-Small Cell Lung Cancer Cells.

Non-small cell lung cancer (NSCLC) results in high mortality and has gained increasing attention. C-Phycocyanin (C-PC) has been identified as a potential therapeutic inhibitor for NSCLC, but its underlying mechanism remains obscure. The gene expression of the long noncoding RNA neighbour of BRCAI RNA 2 (NBR2) in NSCLC cells was evaluated by quantitative reverse transcription-PCR. The cell capacity for proliferation and migration was examined by EdU and wound-healing assays. Furthermore, the viability and apoptosis of cells was measured with CCK-8 and annexin V/PI, respectively. Next, the protein level of activation of adenosine monophosphate- activated protein kinase and the rapamycin kinase (mTOR) signalling pathway-associated molecules was evaluated by western blotting. H292 cells were pre-treated with C-PC or transfected with plasmids encoding NBR2 or the shNBR2 plasmid, to over-express or knock down NBR2 expression, respectively. NBR2 expression was robustly down-regulated in NSCLC cell lines compared with a normal cell line (BEAS-2B). NBR2 over-expression inhibited migration and promoted apoptosis of H292 cells. Treatment of H292 cells with C-PC enhanced NBR2 levels in a dose- and time-dependent manner. Downregulation of NBR2 in H292 cells inhibited the activity of C-PC on cell proliferation, viability and clone formation. Further mechanistic investigation showed that the down-regulation of NBR2 abolished the modulatory effects of C-PC on the AMPK/mTOR signalling pathway. In conclusion, C-PC inhibits H292 cell growth by enhancing the NBR2/AMPK signalling pathway.

Anticancer activity of linalool: comparative investigation of ultrastructural changes and apoptosis in breast cancer cells.

Breast cancer is the most common cancer in women in the world. Many anticancer drugs are currently used clinically have been isolated from plant species or are based on such substances. Linalool is aromatic compounds from the monoterpene group. It is the main constituents of essential oils and show antiproliferative, antioxidant, and antiseptic properties. The aim of this study was to investigate the antiproliferativeand apoptotic, effects of linalool in MCF-7 and MDA-MB-231 human breast cancer cells. MCF-7 and MDA-MB-231 human breast cancer cells were treated with different concentrations of linalool (100, 200, 400, 600, 800, 1000 µM) at 24 h and 48 h. MTT assay for cell proliferation and Annexin V assay for apoptosis was done. The morphology of breast cancer cells was investigated by light microscope and scanning electron microscope (SEM). The study show that linalool significantly induced apoptosis in all groups as dose and time-dependent (p < .05). Linalool has apoptotic and antiproliferative properties in a concentration and time-dependent manner in breast cancer cells. The cytotoxic effects of linalool on MCF-7 and MDA-MB-231 human breast cancer cells was found to be associated with apoptotic cell death. Linalool was more effective on MCF-7 human breast cancer cells in smaller amounts.

ROS/JNK-mediated lysosomal injury in rat intestinal epithelial-6 cells during heat stress.

Injury to the intestinal epithelial cells and loss of the intestinal barrier are critical to heatstroke. To reveal the mechanism through which heatstroke leads to intestinal epithelial injury, the relationship between reactive oxygen species (ROS), c-Jun NH2-terminal kinase (JNK), and lysosomes were studied in intestinal epithelial cells subjected to heat stress. Cells of heat stress groups were incubated at 43 °C for 1 h, then incubated at 37 °C as indicated. Control group cells were incubated at 37 °C. Cell-counting kit-8 assay was used to assess cell viability. Cells were labeled with 2'-7'dichlorofluorescin diacetate and acridine orange (AO) staining, respectively, the total ROS and AO were detected by confocal laser scanning microscopy and flow cytometry. Apoptosis was analyzed by flow cytometry using annexin V-fluorescein isothiocyanate/prodium iodide staining, the expressions of mitogen-activated protein kinases were detected by western blotting. Heat stress induced apoptosis and inhibited cell viability, the production of ROS, and lysosomal injury in IEC-6 cells. After pretreatment with the lysosomal cathepsin inhibitor E64, the JNK inhibitor SP600125, or the ROS scavenger NAC, the effect of heat stress on apoptosis or lysosomal injury was significantly attenuated. In conclusion, heat stress induced apoptosis, lysosomal injury, and the accumulation of ROS in IEC-6 cells; mechanistically, this occurred through the ROS-induced activation of JNK signaling, which mediated the lysosomal injury and ultimately apoptosis.

Anti-cancer effects of selective cannabinoid agonists in pancreatic and breast cancer cells.

OBJECTIVE: Cancer ranks first among the causes of morbidity and mortality all over the world, and it is expected to continue to be the main cause of death in the coming years. Therefore, new molecular targets and therapeutic strategies are urgently needed. In many cases, some reports show increased levels of endocannabinoids and their receptors in cancer, a condition often associated with tumour aggressiveness. Recent studies have suggested that cannabinoid-1/2 receptors contribute to tumour growth in a variety of cancers, including pancreatic, colon, prostate, and breast cancer. Understanding how cannabinoids can regulate key cellular processes involved in tumorigenesis, such as: cell proliferation and cell death, is crucial to improving existing and new therapeutic approaches for the cancer patients. The present study was aimed to characterize the in-vitro effect of L-759633 (a selective CB2 receptor agonist), ACPA (a selective CB1 receptor agonist) and ACEA (a selective CB1 receptor agonist) on the cell proliferation, clonogenicity, and apoptosis in pancreatic (PANC1) and breast (MDA-MB-231) cancer cells. METHODS: The viability and/or proliferation of cells were detected by MTS assay. A clonogenic survival assay was used to detect the ability of a single cell to grow into a colony. Apoptosis was determined with Annexin V staining (Annexin V-FITC/PI test) and by analyzing the expression of Bcl-2-associated X protein (Bax) and B-cell lymphoma 2 (Bcl-2). RESULTS: We found that selective CB1/2 agonists suppressed cell proliferation, clonogenicity and induced proapoptotic function in human PANC1 pancreatic and MDA-MB-231 breast cancer cells. Based on our findings, these agonists led to the inhibition of both cell viability and clonogenic growth in a dose dependent manner. CB1/2 agonists were observed to induce intrinsic apoptotic pathway by upregulating Bax, while downregulating Bcl-2 expression levels. CONCLUSION: Our data suggests that CB1/2 agonists have the therapeutic potential through the inhibition of survival of human PANC1 pancreatic and MDA-MB-231 breast cancer cells and also might be linked with further cellular mechanisms for the prevention (Fig. 5, Ref. 49).

Diannexin Can Ameliorate Acute Respiratory Distress Syndrome in Rats by Promoting Heme Oxygenase-1 Expression.

BACKGROUND: The recombinant protein diannexin can inhibit platelet-mediated events, which contribute to acute respiratory distress syndrome (ARDS). Here, we investigated the effect of diannexin and its effect on heme oxygenase-1 (HO-1) in ARDS. METHODS: A total of 32 rats were randomized into sham, ARDS, diannexin (D), and diannexin+HO-1 inhibitor (DH) groups. Alveolar-capillary permeability was evaluated by testing the partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) ratio, lung wet/dry weight ratio, and protein levels in the lung. Inflammation was assessed by measuring cytokine levels in the bronchial alveolar lavage fluid (BALF) and serum and nuclear factor-κB (NF-κB) in the lung tissue. Inducible nitric oxide synthase (iNOS), malondialdehyde (MDA), and myeloperoxidase (MPO) were measured to evaluate the oxidative stress response. Lung tissue pathology and apoptosis were also evaluated. We measured HO-1 expression in the lung tissue to investigate the effect of diannexin on HO-1 in ARDS. RESULTS: Compared with the ARDS group, diannexin improved PaO2/FiO2, lung wet/dry weight ratio, and protein levels in the BALF and decreased levels of cytokines and NF-κB in the lung and serum. Diannexin inhibited the oxidative stress response and significantly ameliorated pathological lung injury and apoptosis. The partial reversal of diannexin effects by a HO-1 inhibitor suggests that diannexin may promote HO-1 expression to ameliorate ARDS. CONCLUSIONS: We showed that diannexin can improve alveolar-capillary permeability, inhibit the oxidative stress response and inflammation, and protect against ARDS-induced lung injury and apoptosis.

Controlled Supramolecular Assembly Inside Living Cells by Sequential Multistaged Chemical Reactions.

Synthetic assembly within living cells represents an innovative way to explore purely chemical tools that can direct and control cellular behavior. We use a simple and modular platform that is broadly accessible and yet incorporates highly intricate molecular recognition, immolative, and rearrangement chemistry. Short bimodular peptide sequences undergo a programmed sequence of events that can be tailored within the living intracellular environment. Each sequential stage of the pathways beginning with the cellular uptake, intracellular transport, and localization imposes distinct structural changes that result in the assembly of fibrillar architectures inside cells. The observation of apoptosis, which is characterized by the binding of Annexin V, demonstrates that programmed cell death can be promoted by the peptide assembly. Higher complexity of the assemblies was also achieved by coassembly of two different sequences, resulting in intrinsically fluorescent architectures. As such, we demonstrate that the in situ construction of architectures within cells will broaden the community's perspective toward how structure formation can impact a living system.

Vincristine induces procoagulant activity of the human lymphoblastic leukemia cell line Jurkat through the release of extracellular vesicles.

Thromboembolic events are frequent and serious complications of acute lymphoblastic leukaemia treatment. The importance of chemotherapy in the pathogenesis of this increased risk is enhanced by the fact that thrombosis rarely occurs at diagnosis. Our study aims at investigating the effect of chemotherapy on pro-coagulant activity (PCA), phosphatidylserine (PS) exposure, tissue factor (TF) activity and derived extracellular vesicles (EV) of Jurkat cells. Jurkat cells were treated with two commonly used chemotherapeutics: Vincristine (VCR) or Daunorubicin (DNR), at relevant concentrations. PCA of cells and derived EV were evaluated using Thrombin generation Assay (TGA). Cells or EV were incubated with annexin V or anti TF antibodies to assess the respective contribution of TF and PS. PS exposure on cells was analysed by flow cytometry. Derived EV were evaluated in fluorescence microscopy and flow cytometry. Untreated Jurkat cells and EV support thrombin generation. Thrombin generation was abolished when PS activity was inhibited by annexin V. VCR treatment resulted in a time dependent increase of thrombin generation. After VCR exposure, TF activity increased as well as PS exposure increased on the cell surface. The increase in TF activity was abolished by annexin V indicating that PS was required. A spontaneous release of EV from Jurkat cells was observed and VCR treatment increased the number of generated EV. Our results indicate that VCR increased the PCA of Jurkat cells predominantly through PS exposure and increased EV generation. Lymphoid blasts derived EV could be biomarkers to determine high thrombotic risk ALL patients.

Wild-type microglia arrest pathology in a mouse model of Rett syndrome.

Rett syndrome is an X-linked autism spectrum disorder. The disease is characterized in most cases by mutation of the MECP2 gene, which encodes a methyl-CpG-binding protein. Although MECP2 is expressed in many tissues, the disease is generally attributed to a primary neuronal dysfunction. However, as shown recently, glia, specifically astrocytes, also contribute to Rett pathophysiology. Here we examine the role of another form of glia, microglia, in a murine model of Rett syndrome. Transplantation of wild-type bone marrow into irradiation-conditioned Mecp2-null hosts resulted in engraftment of brain parenchyma by bone-marrow-derived myeloid cells of microglial phenotype, and arrest of disease development. However, when cranial irradiation was blocked by lead shield, and microglial engraftment was prevented, disease was not arrested. Similarly, targeted expression of MECP2 in myeloid cells, driven by Lysm(cre) on an Mecp2-null background, markedly attenuated disease symptoms. Thus, through multiple approaches, wild-type Mecp2-expressing microglia within the context of an Mecp2-null male mouse arrested numerous facets of disease pathology: lifespan was increased, breathing patterns were normalized, apnoeas were reduced, body weight was increased to near that of wild type, and locomotor activity was improved. Mecp2(+/-) females also showed significant improvements as a result of wild-type microglial engraftment. These benefits mediated by wild-type microglia, however, were diminished when phagocytic activity was inhibited pharmacologically by using annexin V to block phosphatydilserine residues on apoptotic targets, thus preventing recognition and engulfment by tissue-resident phagocytes. These results suggest the importance of microglial phagocytic activity in Rett syndrome. Our data implicate microglia as major players in the pathophysiology of this devastating disorder, and suggest that bone marrow transplantation might offer a feasible therapeutic approach for it.

BCL-2 family member BOK promotes apoptosis in response to endoplasmic reticulum stress.

B-cell lymphoma 2 (BCL-2) ovarian killer (BOK) is a BCL-2 family protein with high homology to the multidomain proapoptotic proteins BAX and BAK, yet Bok(-/-) and even Bax(-/-)Bok(-/-) and Bak(-/-)Bok(-/-) mice were reported to have no overt phenotype or apoptotic defects in response to a host of classical stress stimuli. These surprising findings were interpreted to reflect functional compensation among the BAX, BAK, and BOK proteins. However, BOK cannot compensate for the severe apoptotic defects of Bax(-/-)Bak(-/-) mice despite its widespread expression. Here, we independently developed Bok(-/-) mice and found that Bok(-/-) cells are selectively defective in their response to endoplasmic reticulum (ER) stress stimuli, consistent with the predominant subcellular localization of BOK at the ER. Whereas Bok(-/-) mouse embryonic fibroblasts exposed to thapsigargin, A23187, brefeldin A, DTT, geldanamycin, or bortezomib manifested reduced activation of the mitochondrial apoptotic pathway, the death response to other stimuli such as etoposide, staurosporine, or UV remained fully intact. Multiple organs in Bok(-/-) mice exhibited resistance to thapsigargin-induced apoptosis in vivo. Although the ER stress agents activated the unfolded protein response, both ATF4 and CHOP activation were diminished in Bok(-/-) cells and mice. Importantly, BAX and BAK were unable to compensate for the defective apoptotic response to ER stress observed in SV40-transformed and primary Bok(-/-) cells, and in vivo. These findings support a selective and distinguishing role for BOK in regulating the apoptotic response to ER stress, revealing--to our knowledge--the first bona fide apoptotic defect linked to Bok deletion.