ABSTRACT
OBJECTIVE@#To investigate the effects of asperuloside on cervical cancer based on endoplasmic reticulum (ER) stress and mitochondrial pathway.@*METHODS@#Different doses (12.5-800 µg/mL) of asperuloside were used to treat cervical cancer cell lines Hela and CaSki to calculate the half maximal inhibitory concentration (IC50) of asperuloside. The cell proliferation was analyzed by clone formation assay. Cell apoptosis, intracellular reactive oxygen species (ROS) and mitochondrial membrane potential were determined by flow cytometry. The protein expressions of cleaved-caspase-3, Bcl-2, Bax, Cyt-c, cleaved-caspase-4 and glucose-regulated protein 78 (GRP78) were analyzed by Western blot. And the inhibitor of ER stress, 4-phenyl butyric acid (4-PBA) was used to treat cervical cancer cells to further verify the role of ER stress in the apoptosis of cervical cancer cells induced by asperuloside.@*RESULTS@#Asperuloside of 325, 650, and 1300 µg/mL significantly inhibited the proliferation and promoted apoptosis of Hela and CaSki cells (P<0.01). All doses of asperuloside significantly increased intracellular ROS levels, reduced mitochondrial membrane potential, significantly reduced Bcl-2 protein expression level, and increased Bax, Cyt-c, GRP78 and cleaved-caspase-4 expressions (P<0.01). In addition, 10 mmol/L 4-PBA treatment significantly promoted cell proliferation and reduced apoptosis (P<0.05), and 650 µg/mL asperuloside could reverse 4-PBA-induced increased cell proliferation, decreased apoptosis and cleaved-caspase-3, -4 and GRP78 protein expressions (P<0.05).@*CONCLUSION@#Our study revealed the role of asperuloside in cervical cancer, suggesting that asperuloside promotes apoptosis of cervical cancer cells through ER stress-mitochondrial pathway.
Subject(s)
Female , Humans , Uterine Cervical Neoplasms/metabolism , Caspase 3/metabolism , bcl-2-Associated X Protein/metabolism , Reactive Oxygen Species/metabolism , Endoplasmic Reticulum Chaperone BiP , HeLa Cells , Proto-Oncogene Proteins c-bcl-2/metabolism , Apoptosis , Endoplasmic Reticulum Stress , Cell Line, TumorABSTRACT
SUMMARY: Obesity is commonly associated with chronic tissue inflammation and skeletal muscle dysfunction. The study aimed to investigate the effects of High-Intensity Interval training (HIIT) on myokines and endoplasmic reticulum (ER) stress of diet- induced obese (DIO) mice. Three-month-old C57BL/6 male mice were fed a control (C) diet (n=20) or a high-fat (HF) diet (n=20) for 16 weeks. Then, half of the groups underwent HIIT (treadmill running) for an additional four weeks. HIIT increased calf muscles' contribution to BW (+24 %) and reduced weight gain in HF/HIIT than in HF (-120 %). Intramuscular fat accumulation was observed in HF and HF/ HIIT. Peak velocity was higher in HF/HIIT compared to HF (+26 %). Plasma insulin did not change, but glycemia was lower in HF/HIIT than in HF (-30 %). Fndc5 (+418 %) and Irisin (+72 %) were higher in HF/HIIT than in HF. Muscle Fgf21 was higher in HF/HIIT compared to HF (+30 %). In addition, NfKb (-53 %) and Tnfa (-63 %) were lower in HF/HIIT than in HF. However, Il1b (-86 %), Il6 (- 48 %), Il7 (-76 %), and Il15 (-21 %) were lower in HF/HIIT than in HF. Finally, HIIT reduced ER stress in HF/HIIT compared to HF: Atf4, -61 %; Chop, -61 %; Gadd45, -95 %. In conclusion, HIIT leads to weight loss and avoids muscle depletion. HIIT improves blood glucose, Irisin-Fndc5, and peak velocity. In addition, HIIT mitigates muscle inflammation and ER stress.
La obesidad es asociada comúnmente con inflamación tisular crónica y disfunción del músculo esquelético. El estudio tuvo como objetivo investigar los efectos del entrenamiento de intervalos de alta intensidad (HIIT) en las mioquinas y el estrés del retículo endoplásmico (ER) de ratones obesos inducidos por dieta (DIO). Se alimentó a ratones macho C57BL/6 de tres meses de edad con una dieta control (C) (n=20) o una dieta rica en grasas (HF) (n=20) durante 16 semanas. Luego, la mitad de los grupos se sometieron a HIIT (carrera en una trotadora) durante cuatro semanas más. HIIT aumentó la contribución de los músculos de la pantorrilla al BW (+24 %) y redujo el aumento de peso en HF/HIIT en HF (-120 %). Se observó acumulación de grasa intramuscular en HF y HF/HIIT. La velocidad máxima fue mayor en HF/HIIT en comparación con HF (+26 %). La insulina plasmática no cambió, pero la glucemia fue menor en HF/HIIT que en HF (-30 %). Fndc5 (+418 %) e Irisin (+72 %) fueron mayores en HF/HIIT que en HF. El Fgf21 muscular fue mayor en HF/ HIIT en comparación con HF (+30 %). Además, NfKb (-53 %) y Tnfa (-63 %) fueron menores en HF/HIIT que en HF. Sin embar- go, Il1b (-86 %), Il6 (-48 %), Il7 (-76 %) e Il15 (-21 %) fueron más bajos en HF/HIIT que en HF. Finalmente, HIIT redujo el estrés de RE en HF/HIIT en comparación con HF: Atf4, -61 %; Picar, - 61 %; Gadd45, -95 %. En conclusión, HIIT conduce a la pérdida de peso y evita el agotamiento muscular. HIIT mejora la glucosa en sangre, Irisin-Fndc5 y la velocidad máxima. Además, HIIT mitiga la inflamación muscular y el estrés ER.
Subject(s)
Animals , Male , Mice , Cytokines/physiology , Muscle, Skeletal/physiology , Endoplasmic Reticulum Stress/physiology , High-Intensity Interval Training , Obesity , Gene Expression , Inflammation , Mice, Inbred C57BL , Molecular BiologyABSTRACT
Endoplasmic reticulum (ER) stress, as an emerging hallmark feature of cancer, has a considerable impact on cell proliferation, metastasis, invasion, and chemotherapy resistance. Ovarian cancer (OvCa) is one of the leading causes of cancer-related mortality across the world due to the late stage of disease at diagnosis. Studies have explored the influence of ER stress on OvCa in recent years, while the predictive role of ER stress-related genes in OvCa prognosis remains unexplored. Here, we enrolled 552 cases of ER stress-related genes involved in OvCa from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) cohorts for the screening of prognosis-related genes. The least absolute shrinkage and selection operator (LASSO) regression was applied to establish an ER stress-related risk signature based on the TCGA cohort. A seven-gene signature revealed a favorable predictive efficacy for the TCGA, International Cancer Genome Consortium (ICGC), and another GEO cohort (P<0.001, P<0.001, and P=0.04, respectively). Moreover, functional annotation indicated that this signature was enriched in cellular response and senescence, cytokines interaction, as well as multiple immune-associated terms. The immune infiltration profiles further delineated an immunologic unresponsive status in the high-risk group. In conclusion, ER stress-related genes are vital factors predicting the prognosis of OvCa, and possess great application potential in the clinic.
Subject(s)
Humans , Female , Ovarian Neoplasms/genetics , Cell Proliferation , Cytokines , Endoplasmic Reticulum Stress/geneticsABSTRACT
Renal tubular injury in patients with diabetic kidney disease(DKD) may be accompanied by glomerular and microvascular diseases. It plays a critical role in the progression of renal damage in DKD, and is now known as diabetic tubulopathy(DT). To explore the multi-targeted therapeutic effects and pharmacological mechanisms in vivo of total flavones of Abelmoschus manihot(TFA), an extract from traditional Chinese medicine for treating kidney disease, in attenuating DT, the authors randomly divided all rats into four groups: a normal control group(normal group), a DT model group(model group), a DT model+TFA-treated group(TFA group) and a DT model+rosiglitazone(ROS)-treated group(ROS group). The DT rat model was established based on the DKD rat model by means of integrated measures. After successful modeling, the rats in the four groups were continuously given double-distilled water, TFA suspension, and ROS suspension, respectively by gavage every day. After 6 weeks of treatment, all rats were sacrificed, and the samples of their urine, blood, and kidneys were collected. The effects of TFA and ROS on various indicators related to urine and blood biochemistry, renal tubular injury, renal tubular epithelial cell apoptosis and endoplasmic reticulum stress(ERS), as well as the activation of the protein kinase R-like endoplasmic reticulum kinase(PERK)-eukaryotic translation initiation factor 2α(eIF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP) signaling pathway in the kidney of the DT model rats were investigated. The results indicated that hypertrophy of renal tubular epithelial cells, renal tubular hyperplasia and occlusion, as well as interstitial extracellular matrix and collagen deposition occurred in the DT model rats. Moreover, significant changes were found in the expression degree and the protein expression level of renal tubular injury markers. In addition, there was an abnormal increase in tubular urine proteins. After TFA or ROS treatment, urine protein, the characteristics of renal tubular injury, renal tubular epithelial cell apoptosis and ERS, as well as the activation of the PERK-eIF2α-ATF4-CHOP signaling pathway in the kidney of the DT model rats were improved to varying degrees. Therein, TFA was superior to ROS in affecting the pathological changes in renal tubule/interstitium. In short, with the DT model rats, this study demonstrated that TFA could attenuate DT by multiple targets through inhibiting renal tubular ERS-induced cell apoptosis in vivo, and its effect and mechanism were related to suppressing the activation of the PERK-eIF2α-ATF4-CHOP signaling pathway in the kidney. These findings provided preliminary pharmacological evidence for the application of TFA in the clinical treatment of DT.
Subject(s)
Rats , Animals , Abelmoschus , Reactive Oxygen Species/metabolism , Flavones/pharmacology , Endoplasmic Reticulum Stress , Diabetic Nephropathies/drug therapy , Apoptosis , Diabetes MellitusABSTRACT
Epilepsies are a group of chronic neurological disorders characterized by spontaneous recurrent seizures caused by abnormal synchronous firing of neurons and transient brain dysfunction. The underlying mechanisms are complex and not yet fully understood. Endoplasmic reticulum (ER) stress, as a condition of excessive accumulation of unfolded and/or misfolded proteins in the ER lumen, has been considered as a pathophysiological mechanism of epilepsy in recent years. ER stress can enhance the protein processing capacity of the ER to restore protein homeostasis through unfolded protein response, which may inhibit protein translation and promote misfolded protein degradation through the ubiquitin-proteasome system. However, persistent ER stress can also cause neuronal apoptosis and loss, which may aggravate the brain damage and epilepsy. This review has summarized the role of ER stress in the pathogenesis of genetic epilepsy.
Subject(s)
Humans , Endoplasmic Reticulum Stress/genetics , Unfolded Protein Response , Endoplasmic Reticulum/pathology , Apoptosis , Epilepsy/geneticsABSTRACT
Preeclampsia and intrauterine growth restriction (IUGR) of the fetus are the two most common pregnancy complications worldwide, affecting 5%-10% of pregnant women. Preeclampsia is associated with significantly increased maternal and fetal morbidity and mortality. Hypoxia-induced uteroplacental dysfunction is now recognized as a key pathological factor in preeclampsia and IUGR. Reduced oxygen supply (hypoxia) disrupts mitochondrial and endoplasmic reticulum (ER) function. Hypoxia has been shown to alter mitochondrial reactive oxygen species (ROS) homeostasis and induce ER stress. Hypoxia during pregnancy is associated with excessive production of ROS in the placenta, leading to oxidative stress. Oxidative stress occurs in a number of human diseases, including high blood pressure during pregnancy. Studies have shown that uterine placental tissue/cells in preeclampsia and IUGR show high levels of oxidative stress, which plays an important role in the pathogenesis of both the complications. This review summarizes the role of hypoxia-induced mitochondrial oxidative stress and ER stress in the pathogenesis of preeclampsia/IUGR and discusses the potential therapeutic strategies targeting oxidative stress to treat both the pregnancy complications.
Subject(s)
Pregnancy , Female , Humans , Placenta , Fetal Growth Retardation/etiology , Pre-Eclampsia/pathology , Reactive Oxygen Species , Hypoxia/pathology , Pregnancy Complications/pathology , Endoplasmic Reticulum StressABSTRACT
The aim of this study was to investigate the role of selenoprotein M (SelM) in endoplasmic reticulum stress and apoptosis in nickel-exposed mouse hearts and to explore the detoxifying effects of melatonin. At 21 d after intraperitoneal injection of nickel chloride (NiCl2) and/or melatonin into male wild-type (WT) and SelM knockout (KO) C57BL/6J mice, NiCl2 was found to induce changes in the microstructure and ultrastructure of the hearts of both WT and SelM KO mice, which were caused by oxidative stress, endoplasmic reticulum stress, and apoptosis, as evidenced by decreases in malondialdehyde (MDA) content and total antioxidant capacity (T-AOC) activity. Changes in the messenger RNA (mRNA) and protein expression of genes related to endoplasmic reticulum stress (activating transcription factor 4 (ATF4), inositol-requiring protein 1 (IRE1), c-Jun N-terminal kinase (JNK), and C/EBP homologous protein (CHOP)) and apoptosis (B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), Caspase-3, Caspase-9, and Caspase-12) were also observed. Notably, the observed damage was worse in SelM KO mice. Furthermore, melatonin alleviated the heart injury caused by NiCl2 in WT mice but could not exert a good protective effect in the heart of SelM KO mice. Overall, the findings suggested that the antioxidant capacity of SelM, as well as its modulation of endoplasmic reticulum stress and apoptosis, plays important roles in nickel-induced heart injury.
Subject(s)
Animals , Male , Mice , Antioxidants/pharmacology , Apoptosis , Endoplasmic Reticulum Stress , Melatonin/pharmacology , Mice, Inbred C57BL , Nickel/adverse effects , Selenoproteins/genetics , Heart/drug effectsABSTRACT
Alkaloids are a class of naturally occurring bioactive compounds that are widely distributed in various food sources and Traditional Chinese Medicine. This study aimed to investigate the therapeutic effects and underlying mechanisms of alkaloid extract from Codonopsis Radix (ACR) in ameliorating hepatic lipid accumulation in a mouse model of non-alcoholic fatty liver disease (NAFLD) induced by a high-fat diet (HFD). The results revealed that ACR treatment effectively mitigated the abnormal weight gain and hepatic injury associated with HFD. Furthermore, ACR ameliorated the dysregulated lipid metabolism in NAFLD mice, as evidenced by reductions in serum triglyceride, total cholesterol, and low-density lipoprotein levels, accompanied by a concomitant increase in the high-density lipoprotein level. ACR treatment also demonstrated a profound anti-oxidative effect, effectively alleviating HFD-induced oxidative stress and promoting ATP production. These effects were achieved through the up-regulation of the activities of mitochondrial electron transfer chain complexes I, II, IV, and V, in addition to the activation of the AMPK/PGC-1α pathway, suggesting that ACR exhibits therapeutic potential in alleviating the HFD-induced dysregulation of mitochondrial energy metabolism. Moreover, ACR administration mitigated HFD-induced endoplasmic reticulum (ER) stress and suppressed the overexpression of ubiquitin-specific protease 14 (USP14) in NAFLD mice. In summary, the present study provides compelling evidence supporting the hepatoprotective role of ACR in alleviating lipid deposition in NAFLD by improving energy metabolism and reducing oxidative stress and ER stress. These findings warrant further investigation and merit the development of ACR as a potential therapeutic agent for NAFLD.
Subject(s)
Mice , Animals , Non-alcoholic Fatty Liver Disease/metabolism , Codonopsis , Liver , Lipid Metabolism , Antineoplastic Agents/pharmacology , Alkaloids/pharmacology , Endoplasmic Reticulum Stress , Energy Metabolism , Lipids , Diet, High-Fat/adverse effects , Mice, Inbred C57BLABSTRACT
OBJECTIVE@#To demonstrate the mechanism of mechanical ventilation (MV) induced endoplasmic reticulum stress (ERS) promoting mechanical ventilation-induced pulmonary fibrosis (MVPF), and to clarify the role of angiotensin receptor 1 (AT1R) during the process.@*METHODS@#The C57BL/6 mice were randomly divided into four groups: Sham group, MV group, AT1R-shRNA group and MV+AT1R-shRNA group, with 6 mice in each group. The MV group and MV+AT1R-shRNA group mechanically ventilated for 2 hours after endotracheal intubation to establish MVPF animal model (parameter settings: respiratory rate 70 times/minutes, tidal volume 20 mL/kg, inhated oxygen concentration 0.21). The Sham group and AT1R-shRNA group only underwent intubation after anesthesia and maintained spontaneous breathing. AT1R-shRNA group and MV+AT1R-shRNA group were airway injected with the adeno-associated virus one month before modeling to inhibit AT1R gene expression in lung tissue. The expressions of AT1R, ERS signature proteins [immunoglobulin heavy chain-binding protein (BIP), protein disulfide isomerase (PDI)], fibrosis signature proteins [collagen I (COL1A1), α-smooth muscle actin (α-SMA)] in lung tissues were detected by immunofluorescence and Western blotting. Hematoxylin-eosin (HE) staining was used to evaluate lung injury and Masson staining was used to evaluate pulmonary fibrosis.@*RESULTS@#Compared with the Sham group, the degree of pulmonary fibrosis and lung injury were more significant in the MV group. In the MV group, the protein expressions of AT1R, BIP, PDI, COL1A1 and α-SMA were increased (AT1R/β-actin: 1.40±0.02 vs. 1, BIP/β-actin: 2.79±0.07 vs. 1, PDI/β-actin: 2.07±0.02 vs. 1, COL1A1/α-Tubulin: 2.60±0.15 vs. 1, α-SMA/α-Tubulin: 2.80±0.25 vs. 1, all P < 0.01). The number of E-cad+/AT1R+ and E-cad+/BIP+ cells in lung tissue increased, and the fluorescence intensity of COL1A1 and α-SMA increased. Compared with the MV group, the degree of pulmonary fibrosis and lung injury were significantly relieved in the MV+AT1R-shRNA group. In the MV+AT1R-shRNA group, the protein expressions of AT1R, BIP, PDI, COL1A1 and α-SMA were decreased (AT1R/β-actin: 0.53±0.03 vs. 1.40±0.02, BIP/β-actin: 1.73±0.15 vs. 2.79±0.07, PDI/β-actin: 1.04±0.07 vs. 2.07±0.02, COL1A1/α-Tubulin: 1.29±0.11 vs. 2.60±0.15, α-SMA/α-Tubulin: 1.27±0.10 vs. 2.80±0.25, all P < 0.01). The number of E-cad+/AT1R+ and E-cad+/BIP+ cells in lung tissue decreased, and the fluorescence intensity of COL1A1 and α-SMA decreased. There was no statistically significant difference in the indicators between AT1R-shRNA group and Sham group.@*CONCLUSIONS@#MV up-regulate the expression of AT1R in alveolar epithelial cells, activate the AT1R pathway, induce ERS and promote the progression of MVPF.
Subject(s)
Mice , Animals , Pulmonary Fibrosis/chemically induced , Lung Injury , Respiration, Artificial/adverse effects , Actins/metabolism , Tubulin , Mice, Inbred C57BL , Endoplasmic Reticulum Stress , RNA, Small InterferingABSTRACT
This study investigated the mechanism of Gegen Qinlian Decoction(GQD) in improving glucose metabolism in vitro and in vivo by alleviating endoplasmic reticulum stress(ERS). Molecular docking was used to predict the binding affinity between the main effective plasma components of GQD and ERS-related targets. Liver tissue samples were obtained from normal rats, high-fat-induced diabetic rats, rats treated with metformin, and rats treated with GQD. RNA and protein were extracted. qPCR was used to measure the mRNA expression of ERS marker glucose-regulated protein 78(GRP78), and unfolded protein response(UPR) genes inositol requiring enzyme 1(Ire1), activating transcription factor 6(Atf6), Atf4, C/EBP-homologous protein(Chop), and caspase-12. Western blot was used to detect the protein expression of GRP78, IRE1, protein kinase R-like ER kinase(PERK), ATF6, X-box binding protein 1(XBP1), ATF4, CHOP, caspase-12, caspase-9, and caspase-3. The calcium ion content in liver tissues was determined by the colorimetric assay. The ERS-HepG2 cell model was established in vitro by inducing with tunicamycin for 6 hours, and 2.5%, 5%, and 10% GQD-containing serum were administered for 9 hours. The glucose oxidase method was used to measure extracellular glucose levels, flow cytometry to detect cell apoptosis, glycogen staining to measure cellular glycogen content, and immunofluorescence to detect the expression of GRP78. The intracellular calcium ion content was measured by the colorimetric assay. Whereas Western blot was used to detect GRP78 and ERS-induced IRE1, PERK, ATF6, and eukaryotic translation initiation factor 2α(eIF2α) phosphorylation. Additionally, the phosphorylation levels of insulin receptor substrate 1(IRS1), phosphatidylinositol 3-kinase regulatory subunit p85(PI3Kp85), and protein kinase B(Akt), which were involved in the insulin signaling pathway, were also measured. In addition, the phosphorylation levels of c-Jun N-terminal kinases(JNKs), which were involved in both the ERS and insulin signaling pathways, were measured by Western blot. Molecular docking results showed that GRP78, IRE1, PERK, ATF4, and various compounds such as baicalein, berberine, daidzein, jateorhizine, liquiritin, palmatine, puerarin and wogonoside had strong binding affinities, indicating that GQD might interfere with ERS-induced UPR. In vivo results showed that GQD down-regulated the mRNA transcription of Ire1, Atf6, Atf4, Grp78, caspase-12, and Chop in diabetic rats, and down-regulated GRP78, IRE1, PERK, as well as ERS-induced apoptotic factors ATF4 and CHOP, caspase-12, caspase-9, and caspase-3, while up-regulating XBP1 to enhance adaptive UPR. In addition, GQD increased the calcium ion content in liver tissues, which facilitated correct protein folding. In vitro results showed that GQD increased glucose consumption in ERS-induced HepG2 cells without significantly affecting cell viability, increased liver glycogen synthesis, down-regulated ATF6 and p-eIF2α(Ser51), and down-regulated IRE1, PERK, and GRP78, as well as p-IRS1(Ser312) and p-JNKs(Thr183/Tyr185), while up-regulating p-PI3Kp85(Tyr607) and p-Akt(Ser473). These findings suggested that GQD alleviates excessive ERS in the liver, reduces insulin resistance, and improves hepatic glucose metabolism in vivo and in vitro.
Subject(s)
Rats , Animals , Proto-Oncogene Proteins c-akt , Endoplasmic Reticulum Chaperone BiP , Caspase 3 , Caspase 9 , Diabetes Mellitus, Experimental , Caspase 12 , Calcium/pharmacology , Molecular Docking Simulation , Endoplasmic Reticulum Stress , Protein Serine-Threonine Kinases/genetics , Liver , Apoptosis , Insulin , Glucose , Glycogen/pharmacology , RNA, MessengerABSTRACT
El retículo endoplásmico es un organelo abundante, dinámico y sensor de energía. Sus abundantes membranas, rugosa y lisa, se encuentran distribuidas en diferentes proporciones dependiendo del linaje y requerimiento celular. Su función es llevar a cabo la síntesis de proteínas y lípidos, y es el almacén principal de Ca2+ intracelular. La sobrecarga calórica y la glucolipotoxicidad generada por dietas hipercalóricas provoca la alteración del retículo endoplásmico, activando la respuesta a proteínas mal plegadas (UPR, Unfolded Protein Response, por sus siglas en inglés) como reacción al estrés celular relacionado con el retículo endoplásmico y cuyo objetivo es restablecer la homeostasis del organelo al disminuir el estrés oxidante, la síntesis de proteínas y la fuga de Ca2+. Sin embargo, durante un estrés crónico, la UPR induce formación de especies reactivas de oxígeno, inflamación y apoptosis, exacerbando el estado del retículo endoplásmico y propagando un efecto nocivo para los demás organelos. Es por ello que el estrés del retículo endoplásmico se ha considerado un inductor del inicio y desarrollo de enfermedades metabólicas, incluido el agravamiento de COVID-19. Hasta el momento, existen pocas estrategias para reestablecer la homeostasis del retículo endoplásmico, las cuales son dirigidas a los sensores que desencadenan la UPR. Por tanto, se justifica con urgencia la identificación de nuevos mecanismos y terapias novedosas relacionadas con mitigar el impacto del estrés del retículo endoplásmico y las complicaciones asociadas.
The endoplasmic reticulum is an abundant, dynamic and energy-sensing organelle. Its abundant membranes, rough and smooth, are distributed in different proportions depending on the cell lineage and requirement. Its function is to carry out protein and lipid synthesis, and it is the main intracellular Ca2+ store. Caloric overload and glycolipotoxicity generated by hypercaloric diets cause alteration of the endoplasmic reticulum, activating the Unfolded Protein Response (UPR) as a reaction to cellular stress related to the endoplasmic reticulum and whose objective is to restore the homeostasis of the organelle by decreasing oxidative stress, protein synthesis and Ca2+ leakage. However, during chronic stress, the UPR induces reactive oxygen species formation, inflammation and apoptosis, exacerbating the state of the endoplasmic reticulum and propagating a deleterious effect on the other organelles. This is why endoplasmic reticulum stress has been considered an inducer of the onset and development of metabolic diseases, including the aggravation of COVID-19. So far, few strategies exist to reestablish endoplasmic reticulum homeostasis, which are targeted to sensors that trigger UPR. Therefore, the identif ication of new mechanisms and novel therapies related to mitigating the impact of endoplasmic reticulum stress and associated complications is urgently warranted.
Subject(s)
Humans , Dietary Carbohydrates/adverse effects , Dietary Fats/adverse effects , Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum Stress/physiology , COVID-19/complications , Metabolic Diseases/etiology , COVID-19/therapy , HomeostasisABSTRACT
OBJECTIVE@#To explore the role of heat shock protein 90α (HSP90α) and endoplasmic reticulum (ER) stress pathway in allergic airway inflammation induced by house dust mite (HDM) in bronchial epithelial cells.@*METHODS@#A HDM- induced asthmatic cell model was established in human bronchial epithelial (HBE) cells by exposure to a concentration gradient (200, 400 and 800 U/mL) of HDM for 24 h. To test the effect of siHSP90α and HSP90 inhibitor 17-AAG on HDM-induced asthmatic inflammation, HBE cells were transfected with siHSP90α (50 nmol, 12 h) or pretreated with 17-AAG (900 nmol, 6 h) prior to HDM exposure (800 U/mL) for 24 h, and the changes in the expression of HSP90α and ER stress markers were assessed. We also tested the effect of nasal drip of 17-AAG, HDM, or their combination on airway inflammation and ER stress in C57BL/6 mice.@*RESULTS@#In HBE cells, HDM exposure significantly up-regulated the expression of HSP90α protein (P=0.011) and ER stress markers XBP-1 (P=0.044), ATF-6α (P=0.030) and GRP-78 (P=0.027). Knocking down HSP90α and treatment with 17-AAG both significantly inhibited HDM-induced upregulation of XBP-1 (P=0.008). In C57BL/6 mice, treatment with 17-AAG obviously improved HDM-induced airway inflammation and significantly reduced the number of inflammatory cells in the airway (P=0.014) and lowered the levels of IL-4 (P=0.030) and IL-5 (P=0.035) in alveolar lavage fluid. Immunohistochemical staining showed that the expressions of XBP-1 and GRP-78 in airway epithelial cells decreased significantly after the treatment of 17-AAG.@*CONCLUSIONS@#HSP90α promotes HDM-induced airway allergic inflammation possibly by upregulating ER stress pathway in bronchial epithelial cells.
Subject(s)
Animals , Mice , Asthma/metabolism , Endoplasmic Reticulum Stress , Epithelial Cells , Inflammation/metabolism , Mice, Inbred C57BL , PyroglyphidaeABSTRACT
Objective: To investigate the effects and molecular mechanism of exogenous L-carnitine on hepatic pyroptosis mediated by excessive endoplasmic reticulum stress in severely scald rats. Methods: The experimental research method was adopted. According to the random number table (the same group method below), fifteen female Sprague Dawley rats aged 6-8 weeks were divided into sham-injury group, scald alone group, and scald+carnitine group (with 5 rats in each group), and full-thickness scald of 30% total body surface area were made on the back of rats in scald alone group and scald+carnitine group, and rats in scald+carnitine group were additionally given intraperitoneal injection of L-carnitine. At post injury hour (PIH) 72, The levels of aspartate aminotransferase (AST) and alanine dehydrogenase (ALT) of biochemical indicators of liver injury were detected by automatic biochemical analyzer with the sample number of 5. At PIH 72, liver tissue damage was detected by hematoxylin-eosin staining. At PIH 72, The mRNA levels of nucleotide-binding oligomerization domain-containing protein-like receptor family pyrin domain containing 3 (NLRP3), cysteine aspartic acid specific protease 1 (caspase-1), gasderminD (GSDMD), and interleukin 1β(IL-1β) in liver tissue as pyroptosis-related markers and glucose regulatory protein 78 (GRP78) and CCAAT/enhancer binding protein homologous protein (CHOP) in liver tissue as endoplasmic reticulum stress-related markers were detected by real-time fluorescence quantitative reverse transcription polymerase chain reaction (RT-qPCR). Protein expression levels of GRP78, CHOP, NLRP3, caspase-1, caspase-1/p20, GSDMD-N, and cleaved IL-1β in liver tissue were detected by Western blotting, and the sample numbers were all 5. HepG2 cells as human liver cancer cells were divided into dimethyl sulfoxide (DMSO) group, 0.1 μmol/L tunicamycin (TM) group, 0.2 μmol/L TM group, 0.4 μmol/L TM group, and 0.8 μmol/L TM group and were treated accordingly. After 24 h of culture, cell viability was detected by cell counting kit 8, and the intervention concentration of TM was screened, and the sample number was 5. HepG2 cells were divided into DMSO group, TM alone group, and TM+carnitine group, and treated accordingly. After 24 h of culture, the protein expression levels of GRP78, CHOP, NLRP3, caspase-1, caspase-1/p20, GSDMD-N, and cleaved IL-1β in cells were detected by Western blotting, and the sample numbers were all 3. Data were statistically analyzed with one-way analysis of variance and least significant difference-t test. Results: At PIH 72, the AST and ALT levels of serum in scald alone group were (640±22) and (157±8) U/L, which were significantly higher than (106±13) and (42±6) U/L in sham-injury group, respectively, with t values of -46.78 and -25.98, respectively, P<0.01. The AST and ALT levels of serum in scald+carnitine group were (519±50) and (121±10) U/L, which were significantly lower than those in scald alone group, respectively, with t values of 4.93 and 6.06, respectively, P<0.01. At PIH 72, the morphology of liver tissue of rats in sham-injury group were basically normal with no obvious inflammatory cell infiltration; compared with those in sham-injury group, the liver tissue of rats in scald alone group showed a large number of inflammatory cell infiltration and disturbed cell arrangement; compared with that in scald alone group, the liver tissue of rats in scald+carnitine group showed a small amount of inflammatory cell infiltration. At PIH 72, the mRNA expression on levels of NLRP3, caspase-1, GSDMD, and IL-1β in liver tissue of rats in scald alone group were significantly higher than those in sham-injury group (with t values of 34.42, 41.93, 30.17, and 15.68, respectively, P<0.01); the mRNA levels of NLRP3, caspase-1, GSDMD, and IL-1β in liver tissue of rats in scald+carnitine group were significantly lower than those in scald alone group (with t values of 34.40, 37.20, 19.95, and 7.88, respectively, P<0.01). At PIH 72, the protein expression levels of NLRP3, caspase-1, caspase-1/p20, GSDMD-N, and cleaved IL-1β in liver tissue of rats in scald alone group were significantly higher than those in sham-injury group (with t values of 12.28, 26.92, 5.20, 10.02, and 24.78, respectively, P<0.01); compared with those in scald alone group, the protein expression levels of NLRP3, caspase-1, caspase-1/p20, GSDMD-N, and cleaved IL-1β in liver tissue of rats in scald+carnitine group were significantly decreased (with t values of 10.99, 27.96, 12.69, 8.96, and 12.27, respectively, P<0.01). At PIH 72, the mRNA levels of GRP78 and CHOP in liver tissue of rats in scald alone group were significantly higher than those in sham-injury group (with t values of 21.00 and 16.52, respectively, P<0.01), and the mRNA levels of GRP78 and CHOP in liver tissue of rats in scald+carnitine group were significantly lower than those in scald alone group (with t values of 8.92 and 8.21, respectively, P<0.01); the protein expression levels of GRP78 and CHOP in liver tissue of rats in scald alone group were significantly higher than those in sham-injury group (with t values of 22.50 and 14.29, respectively, P<0.01), and the protein expression levels of GRP78 and CHOP in liver tissue of rats in scald+carnitine group were significantly lower than those in scald alone group (with t values of 14.29 and 5.33 respectively, P<0.01). After 24 h of culture, the cell survival rates of 0.1 μmol/L TM group, 0.2 μmol/L TM group, 0.4 μmol/L TM group, and 0.8 μmol/L TM group were significantly decreased than that in DMSO group (with t values of 4.90, 9.35, 18.64, and 25.09, respectively, P<0.01). Then 0.8 μmol/L was selected as the intervention concentration of TM. After 24 h of culture, compared with that in DMSO group, the protein expression levels of GRP78 and CHOP in cells in TM alone group were significantly increased (with t values of 10.48 and 17.67, respectively, P<0.01), and the protein expression levels of GRP78 and CHOP in TM+carnitine group were significantly lower than those in TM alone group (with t values of 8.08 and 13.23, respectively, P<0.05 or P<0.01). After 24 h of culture, compared with those in DMSO group, the protein expression levels of NLRP3 and GSDMD-N in cells in TM alone group were significantly increased (with t values of 13.44 and 27.51, respectively, P<0.01), but the protein expression levels of caspase-1, caspase-1/p20, and cleaved IL-1β in cells were not significantly changed (P>0.05); compared with that in TM alone group, the protein expression levels of NLRP3 and GSDMD-N in cells in TM+carnitine group were significantly decreased (with t values of 20.49 and 21.95, respectively, P<0.01), but the protein expression levels of caspase-1, caspase-1/p20, and cleaved IL-1β in cells were not significantly changed (P>0.05). Conclusions: In severely scald rats, exogenous L-carnitine may play a protective role against liver injury by inhibiting the pathways related to excessive endoplasmic reticulum stress-mediated pyroptosis.
Subject(s)
Animals , Female , Humans , Rats , Burns , Carnitine/pharmacology , Caspase 1/pharmacology , Dimethyl Sulfoxide/pharmacology , Endoplasmic Reticulum Stress , Liver , NLR Family, Pyrin Domain-Containing 3 Protein , Pyroptosis , RNA, Messenger , Rats, Sprague-DawleyABSTRACT
OBJECTIVE@#To observe the effect of moxibustion at oppositely-located points "Mingmen" (GV 4) and "Shenque" (CV 8) on the motor function of the hind limbs and bladder function in rats with neurogenic bladder after suprasacral spinal cord injury (SCI), so as to explore the effect of this therapy on bladder tissue apoptosis mediated by endoplasmic reticulum stress pathway.@*METHODS@#Twenty-eight female Wistar rats were randomly divided into a sham-operation group (8 rats) and a model establishment group (20 rats). Using the modified Allen's method, the spinal cord of T10 segment was injured to establish a neurogenic bladder model in the model establishment group. Sixteen rats were modeled successfully and then divided into a model group (8 rats) and a moxibustion group (8 rats). In the moxibustion group, 2 h after consciousness regaining from modeling anesthesia, moxibustion was exerted at "Shenque" (CV 8) and "Mingmen" (GV 4), 2 cones at each acupoint in one intervention. The intervention was administered once every two days and 5-time intervention was required totally. After intervention, Basso, Beattie and Bresnahan locomotor rating scale (BBB) score for the motor function of the hind limbs, and the urodynamics indexes (maximum bladder capacity, urine leakage pressure and bladder compliance) were compared among groups. HE staining method was adopted to observe the morphological changes of bladder tissue. With Western blot method and real-time PCR assay, the protein and mRNA expressions of the endoplasmic reticulum stress-related genes (glucose- regulated protein 78 [GRP78], activating transcription factor 4 [ATF4] and cysteinyl aspartate specific proteinase-12 [Caspase-12]) were determined.@*RESULTS@#The transitional epithelial cells were arranged irregularly, the bladder wall was getting thinner, and the cellular vacuolar degeneration and neutrophil infiltration were found in the model group. Whereas, compared with the model group, in the moxibustion group, the arrangement of transitional epithelial cells was clear and continuous in layers, the cellular vacuolar degeneration was mild and the infiltration presented in a small amount of neutrophil granulocytes. Compared with the sham-operation group, in the model group, the BBB score was reduced (P<0.01), the maximum bladder capacity and bladder compliance were increased (P<0.01), and the protein expression levels of GRP78, ATF4 and Caspase-12, as well as mRNA expressions were all increased (P<0.01). In comparison with the model group, in the moxibustion group, BBB score was increased (P<0.01), the maximum bladder capacity and bladder compliance were decreased (P<0.01), and the protein and mRNA expression levels of GRP78, ATF4 and Caspase-12 were all decreased (P<0.01).@*CONCLUSION@#Moxibustion at the "oppositely-located points" improves the urination function, alleviate urine retention in neurogenic bladder rats after spinal cord injury. The underlying mechanism may be related to the down-regulation of the expressions of GRP78, ATF4 and Caspase-12 in the endoplasmic reticulum stress pathway of the bladder tissues, and thus to alleviate the apoptosis of bladder tissue.
Subject(s)
Animals , Female , Rats , Caspase 12/genetics , Electroacupuncture , Endoplasmic Reticulum Stress , Moxibustion , RNA, Messenger , Rats, Sprague-Dawley , Rats, Wistar , Spinal Cord , Spinal Cord Injuries/therapy , Urinary Bladder, Neurogenic/therapyABSTRACT
Purpose: To investigate the role of peptidyl-prolyl cis/trans isomerase 1 (Pin1) on renal ischemia-reperfusion (I/R) injury and underlying mechanism. Methods: By establishing the in vitro and in vivo models of renal I/R, the role of Pin1 was explored by using molecular assays. Results: In renal I/R, endogenous Pin1 level was up-regulated in I/R-impaired kidney. Suppression of Pin1 with juglone afforded protection against I/R-mediated kidney dysfunction, and reduced I/R-induced endoplasmic reticulum (ER) stress in vivo. Consistent with the in vivo results, repression of Pin1 with juglone or gene knockdown with si-Pin1 conferred cytoprotection and restricted hypoxia/reoxygenation (H/R)-driven ER stress in HK-2 cells. Simultaneously, further study uncovered that Nrf-2/HO-1 signals was the association between Pin1 and ER stress in response to renal I/R. In addition, Nrf-2/HO-1 signal pathway was inactivated after kidney exposed to I/R, as indicated by the down-regulation of Nrf-2/HO-1 levels. Furthermore, inhibition of Pin1 remarkably rescued the inactivation ofNrf-2/HO-1. Conclusions: Pin1 modulated I/R-mediated kidney injury in ER stress manner dependent on Nrf2-HO-1 pathway in I/R injury.
Subject(s)
Animals , Male , Rats , Heme Oxygenase-1 , NF-E2-Related Factor 2/analysis , NIMA-Interacting Peptidylprolyl Isomerase/analysis , Ischemia/veterinary , Reperfusion/veterinary , Rats, Sprague-Dawley , Endoplasmic Reticulum StressABSTRACT
C18 ceramide plays an important role in the occurrence and development of oral squamous cell carcinoma. However, the function of ceramide synthase 1, a key enzyme in C18 ceramide synthesis, in oral squamous cell carcinoma is still unclear. The aim of our study was to investigate the relationship between ceramide synthase 1 and oral cancer. In this study, we found that the expression of ceramide synthase 1 was downregulated in oral cancer tissues and cell lines. In a mouse oral squamous cell carcinoma model induced by 4-nitroquinolin-1-oxide, ceramide synthase 1 knockout was associated with the severity of oral malignant transformation. Immunohistochemical studies showed significant upregulation of PCNA, MMP2, MMP9, and BCL2 expression and downregulation of BAX expression in the pathological hyperplastic area. In addition, ceramide synthase 1 knockdown promoted cell proliferation, migration, and invasion in vitro. Overexpression of CERS1 obtained the opposite effect. Ceramide synthase 1 knockdown caused endoplasmic reticulum stress and induced the VEGFA upregulation. Activating transcription factor 4 is responsible for ceramide synthase 1 knockdown caused VEGFA transcriptional upregulation. In addition, mild endoplasmic reticulum stress caused by ceramide synthase 1 knockdown could induce cisplatin resistance. Taken together, our study suggests that ceramide synthase 1 is downregulated in oral cancer and promotes the aggressiveness of oral squamous cell carcinoma and chemotherapeutic drug resistance.
Subject(s)
Animals , Mice , Apoptosis , Carcinoma, Squamous Cell , Cell Line, Tumor , Down-Regulation , Endoplasmic Reticulum Stress , Head and Neck Neoplasms , Mouth Neoplasms , OxidoreductasesABSTRACT
Endoplasmic reticulum (ER) is an important organelle where folding and post-translational modification of secretory and transmembrane proteins take place. During virus infection, cellular or viral unfolded and misfolded proteins accumulate in the ER in an event called ER stress. To maintain the equilibrium homeostasis of the ER, signal-transduction pathways, known as unfolded protein response (UPR), are activated. The viruses in turn manipulate UPR to maintain an environment favorable for virus survival and replication. Herpesviruses are enveloped DNA viruses that produce over 70 viral proteins. Modification and maturation of large quantities of viral glycosylated envelope proteins during virus replication may induce ER stress, while ER stress play both positive and negative roles in virus infection. Here we summarize the research progress of crosstalk between herpesvirus infection and the virus-induced ER stress.
Subject(s)
Endoplasmic Reticulum/metabolism , Endoplasmic Reticulum Stress , Herpesviridae , Signal Transduction , Unfolded Protein ResponseABSTRACT
As an extremely important organelle in eukaryotic cells, endoplasmic reticulum (ER) plays a key role in the synthesis and processing of biomacromolecules, material transport, ion homeostasis maintenance, signal transduction, exchange of materials and signals between organelles. Many important human diseases, such as cancers, autoimmune diseases, pathogenic infections, neurodegenerative diseases and diabetes, are closely related to ER dysfunction. With the development of nanotechnology, the exploration and application of ER-targeted nanodrugs gradually become a research hotspot in the field of nanomedicine, bioengineering, material chemistry and other fields. In this paper, the relationship between ER dysfunction and disease occurrence, the principle of designing ER-targeted nanodrugs and their biomedical application are reviewed. ER-targeted nanodrugs are designed based on nanodrug carriers or self-assembly of bioactive molecules. These nanodrugs could target the ER in an active or passive manner and function by disrupting or maintaining the ER functions. The ER-targeting nanodrugs have a wide application prospect in cancer therapy, immune regulation, nervous system repairment, and so on.
Subject(s)
Humans , Endoplasmic Reticulum , Endoplasmic Reticulum Stress , Homeostasis , Neoplasms/drug therapy , Signal TransductionABSTRACT
To explore the protective effect and mechanism of ethyl acetate extract from Bidens bipinnata on hepatocyte damage induced by endoplasmic reticulum stress. Tunicamycin was used to establish the damage model in L02 cells. Methyl thiazolyl tetrazolium(MTT) colorimetric assay was used to investigate the survival rate of ethyl acetate extract from B. bipinnata in L02 cells injury induced by endoplasmic reticulum stress; the protein expressions of endoplasmic reticulum stress-related molecule glucose regulated protein 78(GRP78), PKR-like ER kinase(PERK), eukaryotic initiation factor-2(eIF2α), activating transcription factor 4(ATF4), C/EBP homologous protein(CHOP), B-cell CLL/lymphoma 2(Bcl-2), Bal-2 associated X apoptosis regulator(Bax) were examined by Wes-tern blot. The expressions of the above proteins were also detected after endoplasmic reticulum stress inhibitor(4-phenyl butyric acid) and CHOP shRNA-mediated knockdowns were added. The expressions of GRP78, PERK, CHOP in L02 cells were observed by immunofluorescence method. The results showed that ethyl acetate extract from B. bipinnata could significantly increase the survival rate of L02 cell injury caused by endoplasmic reticulum stress in a dose and time-dependent manner(P<0.05 or P<0.01). The expression levels of GRP78, PERK, eIF2α, ATF4, CHOP and Bax in the drug treatment groups were significantly down-regulated(P<0.05 or P<0.01), while Bcl-2 was significantly up-regulated(P<0.01). After endoplasmic reticulum stress inhibitor and CHOP shRNA-mediated knockdowns were added, the expression levels of GRP78, PERK, eIF2α, ATF4, CHOP, Bax in the drug treatment groups were significantly down-regulated(P<0.01), whereas Bcl-2 was significantly up-regulated(P<0.01). Immunofluorescence results showed that the expressions of GRP78, PERK, CHOP were consistent with the Western blot method. In conclusion, ethyl acetate extract from B. bipinnata has a significant protective effect on the damage of L02 cells caused by endoplasmic reticulum stress. The mechanism may be related to the inhibition of endoplasmic reticulum stress and the down-regulation of apoptosis in cells through the PERK/eIF2α/ATF4/CHOP signaling pathway.
Subject(s)
Acetates , Apoptosis , Bidens , Endoplasmic Reticulum Stress , Hepatocytes , Transcription Factor CHOP/genetics , eIF-2 Kinase/geneticsABSTRACT
There have been recent extensive studies and rapid advancement on the pathogenesis underlying idiopathic pulmonary fibrosis (IPF), and intricate pathogenesis of IPF has been suggested. The purpose of this study was to clarify the logical relationship between these mechanisms. An extensive search was undertaken of the PubMed using the following keywords: "etiology," "pathogenesis," "alveolar epithelial cell (AEC)," "fibroblast," "lymphocyte," "macrophage," "epigenomics," "histone," acetylation," "methylation," "endoplasmic reticulum stress," "mitochondrial dysfunction," "telomerase," "proteases," "plasminogen," "epithelial-mesenchymal transition," "oxidative stress," "inflammation," "apoptosis," and "idiopathic pulmonary fibrosis." This search covered relevant research articles published up to April 30, 2020. Original articles, reviews, and other articles were searched and reviewed for content; 240 highly relevant studies were obtained after screening. IPF is likely the result of complex interactions between environmental, genetic, and epigenetic factors: environmental exposures affect epigenetic marks; epigenetic processes translate environmental exposures into the regulation of chromatin; epigenetic processes shape gene expression profiles; in turn, an individual's genetic background determines epigenetic marks; finally, these genetic and epigenetic factors act in concert to dysregulate gene expression in IPF lung tissue. The pathogenesis of IPF involves various imbalances including endoplasmic reticulum, telomere length homeostasis, mitochondrial dysfunction, oxidant/antioxidant imbalance, Th1/Th2 imbalance, M1-M2 polarization of macrophages, protease/antiprotease imbalance, and plasminogen activation/inhibition imbalance. These affect each other, promote each other, and ultimately promote AEC/fibroblast apoptosis imbalance directly or indirectly. Excessive AEC apoptosis and impaired apoptosis of fibroblasts contribute to fibrosis. IPF is likely the result of complex interactions between environmental, genetic, and epigenetic factors. The pathogenesis of IPF involves various imbalances centered on AEC/fibroblast apoptosis imbalance.