scholarly journals 4-phenylbutyric acid alleviates bleomycin-induced pulmonary fibrosis in mouse via inhibition of endoplasmic reticulum stress

2020 ◽  
Author(s):  
Yun Yang ◽  
Deyue Cui ◽  
Hui Bi ◽  
Qian He ◽  
Yunqi Ge ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Pulmonary Fibrosis ◽  
Er Stress ◽  
Mouse Lung ◽  
Control Group ◽  
Healthy Controls ◽  
Chemical Chaperone ◽  
Expression Levels ◽  
Mouse Lung Tissue ◽  
Phenylbutyric Acid

Abstract Background: 4-phenylbutyric acid (4-PBA) is a chemical chaperone that may aid the folding of proteins and alleviate endoplasmic reticulum (ER) stress by inhibiting the unfolded protein response (UPR). This study explores the effects of 4-PBA on idiopathic pulmonary fibrosis (IPF) using a murine model of bleomycin (BLM)-induced pulmonary fibrosis.Methods: Pulmonary fibrosis was induced in C57BL/6 mice by intratracheal injection of BLM. Sixty mice were randomly allocated into three groups: BLM group (n=20), BLM+4-PBA group (n=20), and control group (n=20). Lung tissues and lung function were analyzed to evaluate the degree of pulmonary fibrosis and the survival of the mice was noted. The expression levels of the ER stress markers activating transcription factor 6 (ATF6) and C/EBP Homologous Protein (CHOP) were analyzed in lung tissues from IPF patients and healthy controls as well as the mice.Results: Lung tissues from IPF patients expressed significantly higher levels of ATF6 and CHOP compared to those from healthy controls. BLM induced significant collagen deposition in the lungs of the mice, which was prevented by 4-PBA. 4-PBA also dramatically improved pulmonary function and increased the survival rate in the BLM+4-PBA group compared to that in the BLM group. Both the protein and mRNA expression levels of ATF6 and CHOP were significantly reduced in mouse lung tissue after 2 weeks of 4-PBA treatment.Conclusions: This study demonstrated that 4-PBA treatment could alleviate BLM-induced pulmonary fibrosis in mice via the attenuation of ER stress.

scholarly journals 4-Phenylbutyric Acid Reduces Endoplasmic Reticulum Stress in Chondrocytes That Is Caused by Loss of the Protein Disulfide Isomerase ERp57

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yvonne Rellmann ◽  
Isabel Gronau ◽  
Uwe Hansen ◽  
Rita Dreier
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Protein Disulfide Isomerase ◽  
Pharmacological Intervention ◽  
Chemical Chaperone ◽  
Disulfide Isomerase ◽  
Cartilage Explant ◽  
Explant Cultures ◽  
Phenylbutyric Acid ◽  
Protein Disulfide

Objective. The integrity of cartilage depends on the correct synthesis of extracellular matrix (ECM) components. In case of insufficient folding of proteins in the endoplasmic reticulum (ER) of chondrocytes, ECM proteins aggregate, ER stress evolves, and the unfolded protein response (UPR) is initiated. By this mechanism, chondrocytes relieve the stress condition or initiate cell death by apoptosis. Especially persistent ER stress has emerged as a pathogenic mechanism in cartilage diseases, such as chondrodysplasias and osteoarthritis. As pharmacological intervention is not available yet, it is of great interest to understand cartilage ER stress in detail and to develop therapeutics to intervene. Methods. ERp57-deficient chondrocytes were generated by CRISPR/Cas9-induced KO. ER stress and autophagy were studied on mRNA and protein level as well as by transmission electron microscopy (TEM) in chondrocyte micromass or cartilage explant cultures of ERp57 KO mice. Thapsigargin (Tg), an inhibitor of the ER-residing Ca2+-ATPase, and 4-Phenylbutyric acid (4-PBA), a small molecular chemical chaperone, were applied to induce or inhibit ER stress. Results. Our data reveal that the loss of the protein disulfide isomerase ERp57 is sufficient to induce ER stress in chondrocytes. 4-PBA efficiently diffuses into cartilage explant cultures and diminishes excessive ER stress in chondrocytes dose dependently, no matter if it is induced by ERp57 KO or stimulation with Tg. Conclusion. ER-stress-related diseases have different sources; therefore, various targets for therapeutic treatment exist. In the future, 4-PBA may be used alone or in combination with other drugs for the treatment of ER-stress-related skeletal disorders in patients.

c-Jun Inhibits Thapsigargin-Induced ER Stress Through Up-Regulation of DSCR1/Adapt78

2008 ◽  
Vol 233 (10) ◽  
pp. 1289-1300 ◽  
Author(s):  
Peng Zhao ◽  
Xiaoyan Xiao ◽  
Agnes S. Kim ◽  
M. Fatima Leite ◽  
Jinxia Xu ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Wild Type Mouse ◽  
Mouse Fibroblast ◽  
Expression Levels ◽  
Mouse Fibroblasts ◽  
The Unfolded Protein Response ◽  
Calcineurin Activity

The endoplasmic reticulum (ER) is exquisitely sensitive to changes in its internal environment. Various conditions, collectively termed “ER stress”, can perturb ER function, leading to the activation of a complex response known as the unfolded protein response (UPR). Although c-Jun N-terminal kinase (JNK) activation is nearly always associated with cell death by various stimuli, the functional role of JNK in ER stress-induced cell death remains unclear. JNK regulates gene expression through the phosphorylation and activation of transcription factors, such as c-Jun. Here, we investigated the role of c-Jun in the regulation of ER stress-related genes. c-Jun expression levels determined the response of mouse fibroblasts to ER stress induced by thapsigargin (TG, an inhibitor of sarco/endoplasmic reticulum Ca2+ ATPase). c-jun−/− mouse fibroblast cells were more sensitive to TG-induced cell death compared to wild-type mouse fibroblasts, while reconstitution of c-Jun expression in c-jun−/− cells (c-Jun Re) enhanced resistance to TG-induced cell death. The expression levels of ER chaperones Grp78 and Gadd153 induced by TG were lower in c-Jun Re than in c-jun−/− cells. Moreover, TG treatment significantly increased calcineurin activity in c-jun−/− cells, but not in c-Jun Re cells. In c-Jun Re cells, TG induced the expression of Adapt78, also known as the Down syndrome critical region 1 (DSCR1), which is known to block calcineurin activity. Taken together, our findings suggest that c-Jun, a transcription factor downstream of the JNK signaling pathway, up-regulates Adapt78 expression in response to TG-induced ER stress and contributes to protection against TG-induced cell death.

scholarly journals Maternal high-fat diet induces metabolic stress response disorders in offspring hypothalamus

2017 ◽  
Vol 59 (1) ◽  
pp. 81-92 ◽  
Author(s):  
Long The Nguyen ◽  
Sonia Saad ◽  
Yi Tan ◽  
Carol Pollock ◽  
Hui Chen
Keyword(s):  
Endoplasmic Reticulum ◽  
Body Weight ◽  
Er Stress ◽  
High Fat Diet ◽  
Maternal Obesity ◽  
Mrna Level ◽  
Metabolic Stress ◽  
High Fat ◽  
Chemical Chaperone ◽  
Protein Levels

Maternal obesity has been shown to increase the risk of obesity and related disorders in the offspring, which has been partially attributed to changes of appetite regulators in the offspring hypothalamus. On the other hand, endoplasmic reticulum (ER) stress and autophagy have been implicated in hypothalamic neuropeptide dysregulation, thus may also play important roles in such transgenerational effect. In this study, we show that offspring born to high-fat diet-fed dams showed significantly increased body weight and glucose intolerance, adiposity and plasma triglyceride level at weaning. Hypothalamic mRNA level of the orexigenic neuropeptide Y (NPY) was increased, while the levels of the anorexigenic pro-opiomelanocortin (POMC), NPY1 receptor (NPY1R) and melanocortin-4 receptor (MC4R) were significantly downregulated. In association, the expression of unfolded protein response (UPR) markers including glucose-regulated protein (GRP)94 and endoplasmic reticulum DNA J domain-containing protein (Erdj)4 was reduced. By contrast, protein levels of autophagy-related genes Atg5 and Atg7, as well as mitophagy marker Parkin, were slightly increased. The administration of 4-phenyl butyrate (PBA), a chemical chaperone of protein folding and UPR activator, in the offspring from postnatal day 4 significantly reduced their body weight, fat deposition, which were in association with increased activating transcription factor (ATF)4, immunoglobulin-binding protein (BiP) and Erdj4 mRNA as well as reduced Parkin, PTEN-induced putative kinase (PINK)1 and dynamin-related protein (Drp)1 protein expression levels. These results suggest that hypothalamic ER stress and mitophagy are among the regulatory factors of offspring metabolic changes due to maternal obesity.

scholarly journals Attenuation of endoplasmic reticulum stress by caffeine ameliorates hyperoxia-induced lung injury

2017 ◽  
Vol 312 (5) ◽  
pp. L586-L598 ◽  
Author(s):  
Ru-Jeng Teng ◽  
Xigang Jing ◽  
Teresa Michalkiewicz ◽  
Adeleye J. Afolayan ◽  
Tzong-Jin Wu ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Lung Injury ◽  
Er Stress ◽  
Saline Control ◽  
Sprague Dawley ◽  
Chemical Chaperone ◽  
Stress Markers ◽  
Rat Pups ◽  
Caffeine Treatment ◽  
Downstream Effectors

Rodent pups exposed to hyperoxia develop lung changes similar to bronchopulmonary dysplasia (BPD) in extremely premature infants. Oxidative stress from hyperoxia can injure developing lungs through endoplasmic reticulum (ER) stress. Early caffeine treatment decreases the rate of BPD, but the mechanisms remain unclear. We hypothesized that caffeine attenuates hyperoxia-induced lung injury through its chemical chaperone property. Sprague-Dawley rat pups were raised either in 90 (hyperoxia) or 21% (normoxia) oxygen from postnatal day 1 (P1) to postnatal day 10 (P10) and then recovered in 21% oxygen until P21. Caffeine (20 mg/kg) or normal saline (control) was administered intraperitoneally daily starting from P2. Lungs were inflation-fixed for histology or snap-frozen for immunoblots. Blood caffeine levels were measured in treated pups at euthanasia and were found to be 18.4 ± 4.9 μg/ml. Hyperoxia impaired alveolar formation and increased ER stress markers and downstream effectors; caffeine treatment attenuated these changes at P10. Caffeine also attenuated the hyperoxia-induced activation of cyclooxygenase-2 and markers of apoptosis. In conclusion, hyperoxia-induced alveolar growth impairment is mediated, in part, by ER stress. Early caffeine treatment protects developing lungs from hyperoxia-induced injury by attenuating ER stress.

scholarly journals Human menstrual blood-derived stem cells mitigate bleomycin-induced pulmonary fibrosis through anti-apoptosis and anti-inflammatory effects

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Xin Chen ◽  
Yi Wu ◽  
Yanling Wang ◽  
Lijun Chen ◽  
Wendi Zheng ◽  
...  
Keyword(s):  
Stem Cells ◽  
Pulmonary Fibrosis ◽  
Therapeutic Potential ◽  
Lung Fibroblasts ◽  
Menstrual Blood ◽  
Inflammatory Factors ◽  
Mouse Lung ◽  
Control Group ◽  
Antibody Array

Abstract Background Idiopathic pulmonary fibrosis is a kind of diffuse interstitial lung disease, the pathogenesis of which is unclear, and there is currently a lack of good treatment to improve the survival rate. Human menstrual blood-derived mesenchymal stem cells (MenSCs) have shown great potential in regenerative medicine. This study aimed to explore the therapeutic potential of MenSCs for bleomycin-induced pulmonary fibrosis. Methods We investigated the transplantation of MenSCs in a pulmonary fibrosis mouse model induced by BLM. Mouse was divided into three groups: control group, BLM group, MenSC group. Twenty-one days after MenSC transplantation, we examined collagen content, pathological, fibrosis area in the lung tissue, and the level of inflammatory factors of serum. RNA sequence was used to examine the differential expressed gene between three groups. Transwell coculture experiments were further used to examine the function of MenSCs to MLE-12 cells and mouse lung fibroblasts (MLFs) in vitro. Results We observed that transplantation of MenSCs significantly improves pulmonary fibrosis mouse through evaluations of pathological lesions, collagen deposition, and inflammation. Transwell coculturing experiments showed that MenSCs suppress the proliferation and the differentiation of MLFs and inhibit the apoptosis of MLE-12 cells. Furthermore, antibody array results demonstrated that MenSCs inhibit the apoptosis of MLE-12 cells by suppressing the expression of inflammatory-related cytokines, including RANTES, Eotaxin, GM-CSF, MIP-1γ, MCP-5, CCL1, and GITR. Conclusions Collectively, our results suggested MenSCs have a great potential in the treatment of pulmonary fibrosis, and cytokines revealed in antibody array are expected to become the target of future therapy of MenSCs in clinical treatment of pulmonary fibrosis.

Losartan attenuates paraquat-induced pulmonary fibrosis in rats

2014 ◽  
Vol 34 (5) ◽  
pp. 497-505 ◽  
Author(s):  
F Guo ◽  
YB Sun ◽  
L Su ◽  
S Li ◽  
ZF Liu ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Lung Injury ◽  
Mrna Expression ◽  
Collagen Type ◽  
Collagen Type I ◽  
Control Group ◽  
Type I ◽  
Expression Levels ◽  
Relative Expression ◽  
Tgf Β1

Paraquat (PQ) is one of the most widely used herbicides in the world and can cause pulmonary fibrosis in the cases with intoxication. Losartan, an angiotensin II type 1 receptor antagonist, has beneficial effects on the treatment of fibrosis. The aim of this study was to examine the effect of losartan on pulmonary fibrosis in PQ-intoxicated rats. Adult male Sprague Dawley rats ( n = 32, 180–220 g) were randomly assigned to four groups: (i) control group; (ii) PQ group; (iii) PQ + losartan 7d group; and (iv) PQ + losartan 14d group. Losartan treatment (intragastrically (i.g.), 10 mg/kg) was performed for 7 and 14 days after a single i.g. dose of 40 mg/kg PQ. All rats were killed on the 16th day, and hematoxylin–eosin and Masson’s trichrome staining were used to examine lung injury and fibrosis. The levels of hydroxyproline and transforming growth factor β1 (TGF-β1), matrix metallopeptidase 9 (Mmp9), and tissue inhibitor of metalloproteinase 1 (TIMP-1) messenger RNA (mRNA) expression and relative expression levels of collagen type I and III were also detected. PQ caused a significant increase in hydroxyproline content, mRNA expression of TGF-β1, Mmp9, and TIMP-1, and relative expression levels of collagen type I and III (  p < 0.05), while losartan significantly decreased the amount of hydroxyproline and downregulated TGF-β1, Mmp9, and TIMP-1 mRNA and collagen type I and III expressions (  p < 0.05). Histological examination of PQ-treated rats showed lung injury and widespread inflammatory cell infiltration in the alveolar space and pulmonary fibrosis, while losartan could markedly reduce such damage and prevent pulmonary fibrosis. The results of this study indicated that losartan could reduce lung damage and prevent pulmonary fibrosis induced by PQ.

scholarly journals Diesel exhaust particulates induce neutrophilic lung inflammation by modulating endoplasmic reticulum stress-mediated CXCL1/KC expression in alveolar macrophages

2020 ◽  
Author(s):  
Dong Im Kim ◽  
Mi-Kyung Song ◽  
Kyuhong Lee
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Alveolar Macrophages ◽  
Diesel Exhaust ◽  
Lung Inflammation ◽  
Inflammatory Responses ◽  
Cell Damage ◽  
Interferon Γ ◽  
Mouse Lung ◽  
Lung Weight

Abstract Background Exposure to particular matter (PM)2.5, including diesel exhaust particulates (DEP), has adverse effects on the respiratory system. Endoplasmic reticulum (ER) abnormalities contribute to respiratory disease pathogenesis such as lung inflammation. However, there is little published research on the relationship between DEP exposure and ER stress in the respiratory immune system and especially the alveolar macrophages (AM). Here, we examined ER stress and inflammatory responses in a DEP-induced murine lung inflammation model and in DEP-stimulated AM.Results DEP treatment increased relative lung weight and the number of total cells, neutrophils, and lymphocytes in mouse BALF. Histological examinations also showed that DEP exposure induced neutrophilic lung inflammation and increased the number of DEP-pigmented AM. Western blot analysis showed that BiP and CHOP were relatively upregulated in DEP-induced mouse lung tissues. DEP caused cell damage, increased intracellular reactive oxygen species (ROS), and upregulated the genes associated with inflammation (tumor necrosis factor-α, interleukin [IL]-1β, IL-6, interferon-γ, and toll-like receptor 4) and with ER stress (bound immunoglobulin protein [BiP], CCAAT/enhancer binding protein-homologous protein [CHOP], sXBP-1, and activating transcription factor 4) in AM. Furthermore, DEP stimulation upregulated the gene encoding the chemokine CXCL1/KC in AM.Conclusions DEP may contribute to neutrophilic lung inflammation pathogenesis by modulating ER stress-mediated CXCL1/KC expression in alveolar macrophages.

scholarly journals Obesity-Linked Variants of Melanocortin-4 Receptor Are Misfolded in the Endoplasmic Reticulum and Can Be Rescued to the Cell Surface by a Chemical Chaperone

2010 ◽  
Vol 31 (4) ◽  
pp. 605-605
Author(s):  
Susana Granell ◽  
Sameer Mohammad ◽  
Ramanagouda Ramanagoudr-Bhojappa ◽  
Giulia Baldini
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Surface ◽  
Er Stress ◽  
Binding Protein ◽  
Intracellular Localization ◽  
Specific Inhibitor ◽  
Surface Expression ◽  
Cell Surface Expression ◽  
Chemical Chaperone ◽  
Melanocortin 4 Receptor

Abstract Melanocortin-4 receptor (MC4R) is a G protein-coupled receptor expressed in the brain where it controls food intake. Many obesity-linked MC4R variants are poorly expressed at the plasma membrane and are retained intracellularly. We have studied the intracellular localization of four obesity-linked MC4R variants, P78L, R165W, I316S, and I317T, in immortalized neurons. We find that these variants are all retained in the endoplasmic reticulum (ER), are ubiquitinated to a greater extent than the wild-type (wt) receptor, and induce ER stress with increased levels of ER chaperones as compared with wt-MC4R and appearance of CCAAT/enhancer-binding protein homologous protein. Expression of the X-box-binding-protein-1 with selective activation of a protective branch of the unfolded protein response did not have any effect on the cell surface expression of MC4R-I316S. Conversely, the pharmacological chaperone 4-phenyl butyric acid (PBA) increased the cell surface expression of wt-MC4R, MC4R-I316S, and I317T by more than 40%. PBA decreased ubiquitination of MC4R-I316S and prevented ER stress induced by expression of the mutant, suggesting that the drug functions to promote MC4R folding. MC4R-I316S rescued to the cell surface is functional, with a 52% increase in agonist-induced cAMP production, as compared with untreated cells. Also direct inhibition of wt-MC4R and MC4R-I316S ubiquitination by a specific inhibitor of the ubiquitin-activating enzyme 1 increased by approximately 40% the expression of the receptors at the cell surface, and the effects of PBA and ubiquitin-activating enzyme 1 were additive. These data offer a cell-based rationale that drugs that improve MC4R folding or decrease ER-associated degradation of the receptor may function to treat some forms of hereditary obesity.

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