Dataset Information

ERp29 Attenuates Nicotine-Induced Endoplasmic Reticulum Stress and Inhibits Choroidal Neovascularization.

ABSTRACT: Nicotine-induced endoplasmic reticulum (ER) stress in retinal pigment epithelium (RPE) cells is thought to be one pathological mechanism underlying age-related macular degeneration (AMD). ERp29 attenuates tobacco extract-induced ER stress and mitigates tight junction damage in RPE cells. Herein, we aimed to further investigate the role of ERp29 in nicotine-induced ER stress and choroidal neovascularization (CNV). We found that the expression of ERp29 and GRP78 in ARPE-19 cells was increased in response to nicotine exposure. Overexpression of ERp29 decreased the levels of GRP78 and the C/EBP homologous protein (CHOP). Knockdown of ERp29 increased the levels of GRP78 and CHOP while reducing the viability of ARPE-19 cells under nicotine exposure conditions. In the ARPE-19 cell/macrophage coculture system, overexpression of ERp29 decreased the levels of M2 markers and increased the levels of M1 markers. The viability, migration and tube formation of human umbilical vein endothelial cells (HUVECs) were inhibited by conditioned medium from the ERp29-overexpressing group. Moreover, overexpression of ERp29 inhibits the activity and growth of CNV in mice exposed to nicotine in vivo. Taken together, our results revealed that ERp29 attenuated nicotine-induced ER stress, regulated macrophage polarization and inhibited CNV.

SUBMITTER: Lu T

PROVIDER: S-EPMC10649101 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

ERp29 Attenuates Nicotine-Induced Endoplasmic Reticulum Stress and Inhibits Choroidal Neovascularization.

Lu Tu T Xie Fangfang F Huang Chuangxin C Zhou Lijun L Lai Kunbei K Gong Yajun Y Li Zijing Z Li Longhui L Liang Jiandong J Cong Qifeng Q Li Weihua W Ju Rong R Zhang Sarah X SX Jin Chenjin C

International journal of molecular sciences 20231024 21

Nicotine-induced endoplasmic reticulum (ER) stress in retinal pigment epithelium (RPE) cells is thought to be one pathological mechanism underlying age-related macular degeneration (AMD). ERp29 attenuates tobacco extract-induced ER stress and mitigates tight junction damage in RPE cells. Herein, we aimed to further investigate the role of ERp29 in nicotine-induced ER stress and choroidal neovascularization (CNV). We found that the expression of ERp29 and GRP78 in ARPE-19 cells was increased in r ...[more]

PMID: 37958506

Similar Datasets

Project description:Choroidal neovascularization (CNV) is a major cause of severe visual loss in patients with age-related macular degeneration (AMD). Recently, itraconazole has shown potent and dose-dependent inhibition of tumor-associated angiogenesis. We evaluated the anti-angiogenic effect of itraconazole in a rat model of laser-induced CNV. After laser photocoagulation in each eye to cause CNV, right eyes were administered intravitreal injections of itraconazole; left eyes received balanced salt solution (BSS) as controls. On day 14 after laser induction, fluorescein angiography (FA) was used to assess abnormal vascular leakage. Flattened retinal pigment epithelium (RPE)-choroid tissue complex was stained with Alexa Fluor 594-conjugated isolectin B4 to measure the CNV area and volume. Vascular endothelial growth factor receptor 2 (VEGFR2) mRNA and protein expression was determined 1, 4, 7, and 14 days after intravitreal injection by quantitative RT-PCR or Western blot. VEGF levels were analyzed by enzyme-linked immunosorbent assay (ELISA). Intravitreal itraconazole significantly reduced leakage from CNV as assessed by FA and CNV area and volume on flat mounts compared with intravitreal BSS (p = 0.002 for CNV leakage, p<0.001 for CNV area and volume). Quantitative RT-PCR showed significantly lower expression of VEGFR2 mRNA in the RPE-choroid complexes of itraconazole-injected eyes than those of BSS-injected eyes on days 7 and 14 (p = 0.003 and p = 0.006). Western blots indicated that VEGFR2 was downregulated after itraconazole treatment. ELISA showed a significant difference in VEGF level between itraconazole-injected and BSS-injected eyes on days 7 and 14 (p = 0.04 and p = 0.001). Our study demonstrated that intravitreal itraconazole significantly inhibited the development of laser-induced CNV in rats. Itraconazole had anti-angiogenic activity along with the reduction of VEGFR2 and VEGF levels. Itraconazole may prove beneficial for treating CNV as an alternative or adjunct to other therapies.

Project description:Endoplasmic reticulum (ER) stress and apoptotic cell death play an important role in the pathogenesis and perpetuation of inflammatory bowel disease (IBD). We aimed to explore the potential of glutamine to reduce ER stress and apoptosis in a rat model of experimental IBD. Colitis was induced in male Wistar rats by intracolonic administration of 30 mg of 2,4,6-trinitrobenzene sulfonic acid (TNBS). Glutamine (25 mg/dL) was given by rectal route daily for 2 d or 7 d. Both oxidative stress (TBARS concentration and oxidised/reduced glutathione ratio) and ER stress markers (CHOP, BiP, calpain-1 and caspase-12 expression) increased significantly within 48 h of TNBS instillation, and glutamine attenuated the extent of the changes. Glutamine also inhibited the significant increases of ATF6, ATF4 and spliced XBP-1 mRNA levels induced by TNBS instillation. TNBS-colitis resulted in a significant increase in p53 and cytochrome c expression, and a reduced Bcl-xL expression and Bax/Bcl-2 ratio. These effects were significantly inhibited by glutamine. Treatment with the amino acid also resulted in significant decreases of caspase-9, caspase-8 and caspase-3 activities. Double immunofluorescence staining showed co-localization of CHOP and cleaved caspase-3 in colon sections. Phospho-JNK and PARP-1 expression was also significantly higher in TNBS-treated rats, and treatment with glutamine significantly decreased JNK phosphorylation and PARP-1 proteolysis. To directly address the effect of glutamine on ER stress and apoptosis in epithelial cells, the ER stress inducers brefeldin A and tunicamycin were added to Caco-2 cells that were treated with glutamine (5 mM and 10 mM). The significant enhancement in PERK, ATF6 phosphorylated IRE1, BiP and cleaved caspase-3 expression induced by brefeldin A and tunicamycin was partly prevented by glutamine. Data obtained indicated that modulation of ER stress signalling and anti-apoptotic effects contribute to protection by glutamine against damage in TNBS-induced colitis.

Project description:Glucosamine impairs hepatic apolipoprotein B100 (apoB100) production by inducing endoplasmic reticulum (ER) stress and enhancing cotranslational and posttranslational apoB100 degradation (Qiu, W., R. K. Avramoglu, A. C. Rutledge, J. Tsai, and K. Adeli. Mechanisms of glucosamine-induced suppression of the hepatic assembly and secretion of apolipoprotein B-100-containing lipoproteins. J. Lipid Res. 2006. 47: 1749-1761). Here, we report that glucosamine also regulates apoB100 protein synthesis via ER-stress-induced PERK activation. Short-term (4 h) glucosamine treatment of HepG2 cells reduced both cellular (by 62%) and secreted apoB100 (by 43%) without altering apoB100 mRNA. Treatment with proteasomal inhibitors only partially prevented the suppressive effects of glucosamine, suggesting that mechanisms other than proteasomal degradation may also be involved. Glucosamine-induced ER stress was associated with a significantly reduced apoB100 synthesis with no significant change in posttranslational decay rates, suggesting that glucosamine exerted its effect early during apoB biosynthesis. The role of PERK and its substrate, alpha-subunit of eukaryotic initiation factor 2 (eIF2alpha), in the suppressive effects of glucosamine on apoB synthesis was then investigated. Coexpression of apoB15 (normally resistant to intracellular degradation) with wild-type double stranded (ds) RNA activated protein kinase (PKR)-like endoplasmic reticulum kinase (PERK) in COS-7 cells resulted in a dramatic reduction in the levels of newly synthesized apoB15. Interestingly, cotransfection with apoB15 and a kinase inactive PERK mutant (K618A) increased apoB15 expression. In addition, short-term glucosamine treatment stimulated an increase in phosphorylation of PERK and eIF2alpha. Taken together, these data suggest that in addition to the induction of ER-associated degradation and other degradative pathways, ER stress is associated with suppression of apoB synthesis via a PERK-dependent mechanism.

Project description:BackgroundPalmitic acid (PA), the main component of dietary saturated fat, causes apoptosis in many cell types, including mouse granulosa cell. Melatonin, an important endogenous hormone, has beneficial effects on female reproductive processes. Since elevated PA levels are present in follicular fluid (FF) of patients with infertility and are shown to be toxic for granulosa cells, we investigated the molecular mechanisms of PA toxicity in mouse granulosa cells and explored the effects of melatonin on PA-induced apoptosis.MethodsGranulosa cells from immature female mice were cultured for 24 h in medium containing PA and/or melatonin. Then, the effects of PA alone or combined with melatonin on viability, apoptosis and endoplasmic reticulum (ER) stress in granulosa cells were detected by methyl thiazolyl tetrazolium (MTT) assay, flow cytometry assay and western blot. After 48 h of PA and/or melatonin treatment, the concentrations of estradiol (E2) and progesterone (P4) in the culture supernatants were measured with ELISA kits.ResultsIn this study, we explored the effects of melatonin on cell viability and apoptosis in PA-treated mouse granulosa cells and uncovered the signaling pathways involved in these processes. Our results showed that 200-800 μM PA treatment reduces cell viability, induces cell apoptosis, enhances the expression of apoptosis-related genes (Caspase 3 and B-cell lymphoma-2 (BCL-2) associated X protein (BAX)), and activates the expression of ER stress marker genes (glucose-regulated protein 78 (GRP78) and CCAAT/enhancer binding protein homologous protein (CHOP)). Melatonin treatment (1-10 μM) suppresses 400 μM PA-induced cell viability decrease, cell apoptosis, Caspase 3 activation, and BAX, CHOP, and GRP78 expression. In addition, we found that 10 μM melatonin successfully attenuated the 400 μM PA-induced estrogen (E2) and progesterone (P4) decreases.ConclusionsThis study suggests that PA triggers cell apoptosis via ER stress and that melatonin protects cells against apoptosis by inhibiting ER stress in mouse granulosa cells.

Dataset Information

ERp29 Attenuates Nicotine-Induced Endoplasmic Reticulum Stress and Inhibits Choroidal Neovascularization.

Publications

ERp29 Attenuates Nicotine-Induced Endoplasmic Reticulum Stress and Inhibits Choroidal Neovascularization.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets