Asperuloside Promotes Apoptosis of Cervical Cancer Cells through Endoplasmic Reticulum Stress-Mitochondrial Pathway / 中国结合医学杂志

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.

Role of Endoplasmic Reticulum Stress in Atherosclerosis and Its Regulation by Traditional Chinese Medicine： A Review / 中国实验方剂学杂志

Atherosclerosis （AS） is a chronic inflammatory pathological process in which lipid and/or fibrous substances are deposited in the intima of arteries， and it is one of the pathological bases of many cardiovascular and cerebrovascular diseases. Endoplasmic reticulum stress （ERS） is a protective mechanism of cell adaptation. Moderate ERS can reduce abnormal protein aggregation and increase the degradation of misfolded proteins to repair and stabilize the internal environment， while excessive ERS can cause unfolded protein reaction， activate inflammation， oxidative stress， apoptosis， autophagy， and other downstream pathways， and lead to cell damage， or even apoptosis. A large number of studies have shown that ERS mediates a variety of pathological processes related to AS， affects endothelial cells， smooth muscle cells， macrophages， endothelial progenitor cells， and other cell components closely related to its occurrence and development， influences the progress of AS by regulating cell function， and promotes the formation of AS plaque， the transformation of stable plaque to unstable plaque， and the rupture of unstable plaque. Regulation of ERS may be a key target for the prevention and treatment of AS， and it is a research hotspot at present. Traditional Chinese medicine （TCM） believes that the origin of AS is the imbalance of Yin and Yang， the disharmony of Zangfu organs， and the abnormal operation of Qi， blood， and body fluid， which leads to the accumulation of phlegm， blood stasis， and other pathological products in the pulse channels， making the blood flow blocked or misfunction and causing the disease， which belongs to the syndrome of deficiency in origin and excess in superficiality. As the pathogenesis of AS is complex， and the symptoms are diverse， TCM has significant advantages in treating AS because of its multiple targets， multiple pathways， stable efficacy， strong individualization， and high safety. This paper systematically elaborated on the role of ERS in the occurrence and development of AS and summarized the mechanism research on the regulation and control of ERS by Chinese herbal monomer， Chinese herbal extract， Chinese herbal compound， and proprietary medicine， so as to provide a theoretical basis for clinical research and drug development in the prevention and treatment of AS.

Effect of low concentration of sodium fluoride on osteogenic/odontogenic differentiation of human dental pulp cells / 口腔疾病防治

Objective@#To study the effect of low concentrations of sodium fluoride on the osteogenic/odontogenic differentiation of human dental pulp cells (hDPCs) in vitro.@*Methods@#This study was reviewed and approved by the Ethics Committee. hDPCs were cultured using a modified tissue explant technique in vitro. The effects of different concentrations of sodium fluoride on the proliferation of hDPCs were measured by methylthiazol tetrazolium (MTT) assay. Appropriate concentrations were added to the osteogenic/odontogenic differentiation induction medium, and the cells were induced in vitro. Alizarin red S staining was used to detect the osteoblastic/odontogenic differentiation ability of the cells, and the mRNA expression of the key differentiation factors was detected by RT-qPCR. Moreover, the expression of key molecules of endoplasmic reticulum stress (ERS) was detected by RT-qPCR and Western blot. The data were analyzed with the SPSS 18.0 software package.@*Results@#Low concentration of NaF (0.1 mmol/L) could stimulate cell proliferation in vitro, while a high concentration (5-10 mmol/L) could inhibit cell proliferation (P<0.05). According to the literature and the experimental data, 0.1 mmol/L NaF was selected as the following experimental concentration. The levels of alizarin red S staining were increased after NaF induction of mixed osteogenic/odontogenic differentiation in vitro. The mRNA expression levels of key molecules for osteogenic/odontogenic differentiation, dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP) and osteocalcin (OCN), were increased (P<0.05). The mRNA levels of ERS markers (splicing x-box binding protein-1 (sXBP1), glucose-regulated protein 78 (GRP78) and activating transcription Factor 4 (ATF4) were increased in NaF-treated cells. The protein expression levels of key ER stress molecules (phosphorylated RNA-activated protein kinase-like ER-resident kinase (p-PERK), phosphorylated eukaryotic initiation factor-2α (p-eIF2α) and ATF4) were higher in NaF-treated cells.@*Conclusion@#A low concentration of NaF promotes the osteogenic/odontogenic differentiation of hDPCs and increases the level of ER stress.

Mechanism of Yishen Tongluo Prescription in Inhibiting Endoplasmic Reticulum Stress and Improving Apoptosis of Renal Tubular Epithelial Cells Based on PERK/ATF4/CHOP / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Yishen Tongluo prescription （YSTLP） on apoptosis of renal tubular epithelial cells and explore the mechanism based on endoplasmic reticulum stress pathway of protein kinase R-like endoplasmic reticulum kinase （PERK）/activating transcription factor 4 （ATF4）/transcription factor C/EBP homologous protein （CHOP）. MethodThe db/db mice were randomly divided into model group， valsartan group （10 mg·kg-1）， and low， middle， high-dose YSTLP groups （1， 2.5， 5 g·kg-1）. Samples were collected after eight weeks of drug intervention. In addition， db/m mice in the same litter served as the control group. Human renal tubular epithelial cells （HK-2） were cultured in vitro and divided into the control group， advanced glycated end-product （AGE） group， and AGE + low， middle， and high-dose YSTLP groups （100， 200， 400 mg·L-1）. TdT-mediated dUTP nick end labeling （TUNEL） staining was used to detect the apoptosis rate of HK-2 cells. Methylthiazolyldiphenyl-tetrazolium bromide （MTT） assay was conducted to detect the viability of HK-2 cells. Calcium fluorescence probe staining and luciferase reporter gene method were adopted to detect the luciferase activity of folded protein response element （UPRE） and endoplasmic reticulum stress. Immunohistochemical （IHC） analysis was carried out to measure the protein expressions of phosphorylated PKR （p-PERK）， CHOP， and ATF4. Real-time polymerase chain reaction （Real-time PCR） was used to measure the mRNA expression levels of CHOP and X-box binding protein 1 （XBP1） in mouse kidney and HK-2 cells. Western blot was used to detect the protein expression level of p-PERK， PERK， CHOP， ATF4， B-cell lymphoma-2 （Bcl-2）， Bcl-2 associated X protein （Bax）， and cleaved Caspase-3 in mouse kidney and HK-2 cells. ResultIn the cellular assay， HK-2 cell viability was significantly reduced， and the apoptosis rate was elevated in the AGE group compared with the control group （P<0.01）. The mRNA and protein expression levels of apoptosis-related factor Bcl-2 were significantly reduced （P<0.01）， and those of Bax were significantly increased （P<0.01）. The protein expression level of cleaved Caspase-3 was significantly increased （P<0.01）. Compared with the AGE group， YSTLP administration treatment resulted in elevated cell viability and reduced apoptosis rate （P<0.01）. The mRNA and protein expression levels of Bcl-2 were significantly elevated in a time- and dose-dependent manner （P<0.01）， and those of Bax were significantly reduced in a time- and dose-dependent manner. The protein expression level of cleaved Caspase-3 was significantly reduced in a time- and dose-dependent manner （P<0.01）. The intracellular Ca2+ imbalance and UPRE luciferase fluorescence intensity were increased in the AGE group compared with the control group （P<0.01）. The mRNA levels of endoplasmic reticulum stress-related factors CHOP and XBP1 were significantly increased （P<0.01）， and the protein expression levels of p-PERK， CHOP， and ATF4 were significantly increased （P<0.05）. Compared with the AGE group， YSTLP effectively improved intracellular Ca2+ imbalance in HK-2 cells and decreased UPRE luciferase fluorescence intensity in a dose-dependent manner （P<0.01）. It reduced the mRNA levels of endoplasmic reticulum stress-related factors CHOP and XBP1 （P<0.01） and the protein expression levels of intracellular p-PERK， CHOP， and ATF4 in a dose- and time-dependent manner （P<0.01）. In animal experiments， the protein expression level of Bcl-2 was significantly reduced（P<0.01）， and that of cleaved Caspase-3 and Bax was significantly increased in the model group compared with the control group （P<0.05）. The protein expression level of Bcl-2 was dose-dependently elevated， and that of cleaved Caspase-3 and Bax was dose-dependently decreased in the YSTLP groups compared with the model group （P<0.01）. Compared with the control group， the mRNA expression levels of CHOP and XBP1 were significantly elevated in the model group （P<0.05， P<0.01）， and the protein expression levels of p-PERK， CHOP， and ATF4 were significantly increased （P<0.05）. Compared with the model group， YSTLP significantly decreased the mRNA expression levels of CHOP and XBP1 （P<0.01） and the protein expression levels of p-PERK， CHOP， and ATF4 （P<0.01）. ConclusionYSTLP can effectively inhibit endoplasmic reticulum stress and improve apoptosis of renal tubular epithelial cells， and its mechanism may be related to the regulation of the PERK/AFT4/CHOP pathway.

Biological principles for "homotherapy for heteropathy" / 药学学报

Non-infectious chronic diseases in human including diabetes, non-alcoholic fatty liver disease (NAFLD), atherosclerosis (AS), neurodegenerative diseases, osteoporosis, as well as malignant tumors may have some common pathogenic mechanisms such as non-resolved inflammation (NRI), gut microbiota dysfunction, endoplasmic reticulum stress, mitochondria dysfunction, and abnormality of the mammalian target of rapamycin (mTOR) pathway. These pathogenic mechanisms could be the basis for "homotherapy for heteropathy" in clinic. Some commonly used clinical drugs, such as metformin, berberine, aspirin, statins, and rapamycin may execute therapeutic effect on their targeted diseases,and also have the effect of "homotherapy for heteropathy". The mechanisms of the above drugs may include anti-inflammation, modulation of gut microbiota, suppression of endoplasmic reticulum stress, improvement of mitochondria function, and inhibition of mTOR. For virus infectious diseases, as some viruses need certain commonly used replicases, the inhibitors of the replicases become examples of "homotherapy for heteropathy" for antiviral therapy in clinic (for example tenofovir for both AIDS and HBV infection). Especially, in case of outbreak of new emerging viruses, these viral enzyme inhibitors such as azvudine and sofibuvir, could be rapidly used in controlling viral epidemic or pandemic, based on the principle of "homotherapy for heteropathy". In this review article, we show the research progress of the biological basis for "homotherapy for heteropathy" and the possible mechanisms of some well-known drugs, in order to provide insights and new references for innovative drug R&D.

Involvement of intracellular organelle stress, autophagy and ferroptosis in cobalt chloride-induced vascular smooth muscle cell injury / 中国临床药理学与治疗学

AIM: To investigate the relationship between vascular smooth muscle cell (VSMC) injury, organelle stress response and autophagic cell death (autophagy) and ferroptosis induced by the chemical hypoxia inducer cobalt chloride (CoCl2) through the bioinformatics analysis and in vitro cell experimentation. METHODS: The dataset GSE119226 of VSMC treated with cobalt chloride was acquired from the gene expression database (GEO). The R language was used to investigate the relationship between CoCl2 treatment and organelle stress response (Golgi stress, endoplasmic reticulum stress) and two forms of cell death (ferroptosis and autophagic cell death). With primary cultured rat VSMC (rVSMC) and CoCl2-induced anoxia model, the changes in cell viability were detected by CCK-8 method, and reactive oxygen species (ROS) levels were measured using DCFH-DA method. The expression levels of HIF-1α (a key molecule in hypoxia), Golgi stress markers GM130 and p115, endoplasmic reticulum stress markers GRP78 and CHOP, autophagy markers LC3-II / LC3-I and Beclin1, and ferroptosis markers GPx4 and xCT were detected by Western blot. The effect of inducing or inhibiting organelle stress and cell death on the CoCl2-induced cell damage was also observed. RESULTS: Differentially expressed genes analysis of GSE119226 dataset showed that CoCl2 treatment of VSMCs had significant effects on organelle function and stress response, autophagy and ferroptosis-related genes, in which endoplasmic reticulum stress, protein processing in endoplasmic reticulum, regulation of Golgi to plasma membrane protein transport, autophagy / autophagic cell death, and ferroptosis pathways were remarkably enriched. The results of in vitro experiment showed that compared with normal rVSMC, cell viability was significantly decreased after CoCl2 treatment, as well as HIF-1α protein expression and ROS levels in rVSMCs were increased. In rVSMC treated with Co-Cl2, the expression levels of Golgi structural proteins GM130 and p115 (reflecting the occurrence of Golgi stress) were decreased, while the markers GRP78 and CHOP (reflecting the occurrence of endoplasmic reticulum stress) were increased. At the same time, CoCl2 treatment also reduced the expression of autophagy markers LC3-II/LC3-I and Beclin1 (indicating the decrease levels of autophagy), while the expression of ferroptosis markers GPx4 and xCT were decreased (indicating the occurrence of ferroptosis). Compared with CoCl2 treatment group, induced Golgi stress, endoplasmic reticulum stress, or ferroptosis could further reduce cell viability, while inhibition of these processes could improve cell viability. On the other hand, increasing the level of autophagy can improve the cell viability. CONCLUSION: Hypoxia induced by cobalt chloride can lead to VSMC injury. Golgi stress, endoplasmic reticulum stress, ferroptosis, and the reduction of autophagy level play an important role in it. Inhibition of organelle stress response and ferroptosis, or increase of autophagy level can improve VSMC injury caused by cobalt chloride.

Improvement of gefitinib-resistance of PC9/GR by thapsigargin combined with gefitinib / 药学实践杂志

Objective To study the effect and mechanism of the thapsigargin combined with gefitinib on the proliferation of human lung adenocarcinoma gefitinib resistance cell line PC9/GR. Methods The cell viability of PC9/GR treated with gefitinib alone or gefitinib combined with thapsigargin was evaluated by CCK8 assay. The flow cytometry was used to analyze the PC9/GR cell apoptosis indued by the two group drugs. The ATF-6 and IRE1α protein expression of PC9/GR cells treated with the two group drugs were detected by Western blotting. Results The group of drug combination exhibited enhanced ability to inhibit cell proliferation, promote cell apoptosis and upregulate the ATF-6 and IRE1α protein expression of the PC9/GR compared with the group gefitinib used alone. Conclusion The sensitivity of PC9/GR to gefitinib was increased when the cells were treated by thapsigargin, which may be related with the state of endoplasmic reticulum stress（ERS） induced by thapsigargin.

Down-regulating XBP1s alleviates hypoxia/reoxygenation injury of renal tubular epithelial cells by inhibiting ITPR-mediated mitochondrial dysfunction / 器官移植

Objective To evaluate the effect of spliced X-box binding protein 1 (XBP1s) on hypoxia/reoxygenation (H/R) injury of mouse renal tubular epithelial cells and unravel underlying mechanism. Methods Mouse renal tubular epithelial cells were divided into adenovirus negative control group (Ad-shNC group), targeted silencing XBP1s adenovirus group (Ad-shXBP1s group), Ad-shNC+H/R group and Ad-shXBP1s+H/R group. The apoptosis level, mitochondrial reactive oxygen activity, mitochondrial membrane potential and mitochondrial calcium ion level were detected in each group. Chromatin immunocoprecipitation followed by sequencing (ChIP-seq) was employed to analyze the binding sites of XBP1s in regulating the inositol 1,4,5-trisphosphate receptor (ITPR) family. The expression levels of XBP1s and ITPR family messenger RNA (mRNA) and protein were determined in each group. Results Compared with the Ad-shNC group, the apoptosis level was higher, mitochondrial reactive oxygen species level was increased, mitochondrial membrane potential was decreased and mitochondrial calcium ion level was elevated in the Ad-shNC+H/R group. Compared with the Ad-shNC+H/R group, the apoptosis level was lower, mitochondrial reactive oxygen species level was decreased, mitochondrial membrane potential was elevated, and mitochondrial calcium ion level was decreased in the Ad-shXBP1s+H/R group (all P<0.05). Compared with the Ad-shNC group, relative expression levels of XBP1s, ITPR1, ITPR2 and ITPR3 mRNAs and proteins were down-regulated in the Ad-shXBP1s group (all P<0.05). Compared with the Ad-shNC group, relative expression levels of XBP1s, ITPR1, ITPR2 and ITPR3 proteins were up-regulated in the Ad-shNC+H/R group. Compared with the Ad-shNC+H/R group, relative expression levels of XBP1s, ITPR1, ITPR2 and ITPR3 were down-regulated in the Ad-shXBP1s+H/R group (all P<0.05). ChIP-seq results showed that XBP1s could bind to the promoter and exon of ITPR1, the exon of ITPR2, and the exon of ITPR3. Conclusions XBP1s may affect mitochondria-associated endoplasmic reticulum membrane structure and function by directly regulating ITPR transcription and translation. Down-regulating XBP1s may inhibit ITPR expression and mitigate mitochondrial damage.

Research Progress of Endoplasmic Reticulum Stress PERK-eIF2α-AFT4-CHOP Signaling Pathway in Hematological Malignancies / 肿瘤防治研究

The biosynthesis and maturation of proteins are primarily regulated by the endoplasmic reticulum in its physiological state. Thus, the disruption of physiological homeostasis initiates the buildup of unfolded and misfolded proteins in the endoplasmic reticulum, resulting in endoplasmic reticulum stress (ERS) and unfolded protein response (UPR). One of the important pathways by which UPR maintains intracellular homeostasis under ERS is activating protein kinase R-like endoplasmic reticulum kinase (PERK). The activation of the PERK pathway stimulates eukaryotic translation initiation factor 2 subunit-α (eIF2α) phosphorylation and the selective translation of active transcription factor 4 (ATF4), and PERK induces cell apoptosis by directly binding to the promoter of pro-apoptotic transcription factor C/EBP homologous protein (CHOP). This signaling pathway is also one of the important mechanisms by which UPR participates in the regulation of hematological malignancies and immune cells in a tumor microenvironment. This article provides an overview of advancements in research into the PERK-eIF2α-ATF4-CHOP signaling pathway in hematological malignancies and the potential therapeutic benefits of targeting this signaling pathway.

High-intensity interval training (treadmill) effects in myokines and endoplasmic reticulum stress of calf muscles in obese mice / Efectos del entrenamiento interválico de alta intensidad (trotadora) en miocinas y estrés del retículo endoplasmático de los músculos surales en ratones obesos

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.

Regulación del calcio por SERC-A antes de la enfermedad de Alzheimer y durante la misma / Calcium regulation by SERC-A before and during Alzheimer disease

Hay muchos factores implicados en la incidencia de la enfermedad de Alzheimer que, en combinación, terminan por impedir o dificultar las funciones neuronales normales. Actualmente, poco se conoce sobre la regulación del calcio, antes de la enfermedad y durante la misma. La inestabilidad interna de los niveles de calcio se asocia a un mayor riesgo vascular, condición prevalente en un gran número de individuos ya comprometidos por la enfermedad de Alzheimer. Esta revisión proporciona una reevaluación de los mecanismos moleculares de la ATPasa dependiente de Ca2+ del retículo sarcoendoplásmico (SERC-A) en la enfermedad y analiza los aspectos más destacados de la función de los canales de calcio dependientes de voltaje; de esta manera, se podrán abrir nuevas alternativas de tratamiento. Estos mecanismos de regulación son clínicamente relevantes, ya que se ha implicado la función irregular de SERC-A en diversas alteraciones de la función cerebral.

There are many factors involved in the incidence of Alzheimer's disease that, in combination, impede or hinder normal neuronal functions. Little is currently known about calcium regulation before and during the disease. Internal instability of calcium levels is associated with increased vascular risk, a prevalent condition in a high number of individuals already compromised by Alzheimer's disease. This review provides a reevaluation of the molecular mechanism of the sarcoendoplasmic reticulum calcium ATPase (SERC-A) in the disease and discusses salient aspects of voltage-gated calcium channel function; in these way new alternatives could be open for its treatment. These regulation mechanisms are clinically relevant since the irregular functions of SERC+A has been implicated in pathologies of brain function.

Screening of endoplasmic reticulum stress signature-related genes in gastric cancer and the establishment of prognostic risk models / 肿瘤研究与临床

Objective:To screen the endoplasmic reticulum stress (ERS) signature-related differentially expressed genes (DEG) in gastric cancer and to construct a prognostic risk model based on a bioinformatics.Methods:Transcriptome sequencing data (RNA-seq) of 375 gastric cancer and 32 paracancerous tissue samples downloaded from The Cancer Genome Atlas (TCGA) database and the corresponding clinical information were obtained as training set samples; data of 387 gastric cancer patients (GSE84437) from Gene Expression Omnibus (GEO) database were downloaded as validation set samples. All data were obtained on December 25, 2021. A total of 785 ERS signature-related genes (ERS-RG) were obtained from the GeneCards database. DEG between gastric cancer tissues and paracancerous tissues in the TCGA database was analyzed. The identified gastric cancer DEG were intersected with ERS-RG from the GeneCards database to obtain gastric cancer ERS signature-related DEG, which were analyzed for gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. Univariate Cox proportional risk model was used to screen ERS signature-related DEG with prognostic value in gastric cancer, and LASSO regression analysis was performed to construct a polygenic prognostic risk model, and to calculate the prognostic risk score. The patients in training set and validation set were divided into high-risk group and low-risk group according to the median of the prognostic risk score (2.369); Kaplan-Meier survival analysis was used to compare the overall survival (OS) and to draw time-dependent receiver operating characteristic (ROC) curves of patients in the two groups; nomogram was drawn based on the prognostic independent influencing factors of gastric cancer. The characteristic immune cell infiltration abundance between the two groups was analyzed by using the inverse convolution-based CIBERSORT algorithm. Cytolytic activity scores were calculated by using the geometric mean of granzyme A and perforin 1 expression. According to the median prognostic risk score (2.369) and median tumor mutation burden (TMB) (3.000), all patients with gastric cancer were divided into high risk score-high TMB group, high risk score-low TMB group, low risk score-high TMB group and low risk score-low TMB group to compare the OS of patients in each group.Results:A total of 444 ERS signature-related DEG in gastric cancer including 168 down-regulated genes and 276 up-regulated genes were obtained, which were mainly enriched in biological processes such as protein processing in the endoplasmic reticulum, extracellular matrix (ECM) receptor interactions and unfolded protein responses (all P < 0.05). Univariate Cox regression analysis showed that 12 prognostic-related ERS signature-related DEG in gastric cancer were screened out. LASSO regression analysis was performed to obtain a prognostic risk score = 0.052×NOS3+0.137×PON1+0.067×CXCR4+0.131×MATN3+0.116×ANXA5+0.090×SERPINE1. The results of Kaplan-Meier analysis showed that the OS of the low-risk group in both the training and validation sets was better than that of the high-risk group (all P < 0.01). The results of the time-dependent ROC curve analysis showed that the AUC for the 3-year, 5-year, 8-year OS rates was 0.695, 0.786, 0.698, respectively in the training set, while the AUC for the 3-year 5-year, 8-year OS rates was 0.580, 0.625, 0.627, respectively in the validation set. Multivariate Cox regression analysis showed that prognostic risk score ( HR = 3.598, 95% CI 2.290-5.655, P < 0.001) and tumor stage ( HR = 1.344, 95% CI 1.057-1.709, P < 0.05) were independent factors influencing the prognosis of gastric cancer. Among 375 gastric cancer patients in the TCGA database, the expression levels of ATF6, HSPA5, XBP1 and ATF4 in the high-risk group were higher than those in the low-risk group (all P < 0.05); CIBERSORT results showed that the abundance of activated CD4 memory T cells in the high-risk group was lower than that in the low-risk group, and the abundance of both M0 and M2 macrophages in the high-risk group was higher than that in the low-risk group (all P < 0.05). The expression levels of common immune checkpoints (CD274, CTLA4, TNFRSF9, TIGIT, PDCD1, LAG3) in the high-risk group were all higher than those in the low-risk group (all P < 0.05). Cytolytic activity score in the high-risk group was higher than that in the low-risk group ( P < 0.05). The prognostic risk score was negatively correlated with TMB ( r = -0.20, P < 0.001). Patients in the low-risk score-high TMB group had the best OS and those in the high-risk score-low TMB group had the worst OS (both P < 0.001). Conclusions:The prognostic risk score model is established based on 6 ERS signature-related DEG in gastric cancer and its prognostic risk score may be effective as an independent prognostic factor to predict the prognosis of gastric cancer patients.

Protective effect of polypyrimidine tract-binding protein-associated splicing factor on endoplasmic reticulum oxidative stress injury of human retinal microvascular endothelial cells / 中华眼底病杂志

Objective:To observe the effects of overexpression of polypyrimidine tract binding protein-associated splicing factor (PSF) on the endoplasmic reticulum (ER) oxidative stress damage of human retinal microvascular endothelial cells (hRMEC) under high concentration of 4-hydroxynonenal (4-HNE).Methods:The logarithmic growth phase hRMEC cultured in vitro was divided into normal group, simple 4-HNE treatment group (simple 4-HNE group), empty plasmid combined with 4-HNE treatment group (Vec+4-HNE group), and PSF high expression combined with 4-HNE treatment group (PSF+4-HNE group). In 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group cell culture medium, 10 μmol/L 4-HNE was added and stimulated for 12 hours. Subsequently, the Vec+4-HNE group and PSF+4-HNE group were transfected with transfection reagent liposome 2000 into pcDNA empty bodies and pcDNA-PSF eukaryotic expression plasmids, respectively, for 24 hours. Flow cytometry was used to detect the effects of 4-HNE and PSF on cell apoptosis. The effect of PSF overexpression on the expression of reactive oxygen species (ROS) in hRMEC was detected by 2', 7'-dichlorodihydrofluorescein double Acetate probe. Western blot was used to detect ER oxide protein 1 (Ero-1), protein disulfide isomerase (PDI), C/EBP homologous transcription factor (CHOP), glucose regulatory protein (GRP) 78, protein kinase R-like ER kinase (PERK)/phosphorylated PERK (p-PERK), and Eukaryotic initiation factor (eIF) 2α/the relative expression levels of phosphorylated eIF (peIF) and activated transcription factor 4 (ATF4) proteins in hRMEC of normal group, 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group. Single factor analysis of variance was performed for inter group comparison.Results:The apoptosis rates of the simple 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group were (22.50±0.58)%, (26.93±0.55)%, and (11.70±0.17)%, respectively. The intracellular ROS expression levels were 0.23±0.03, 1.60±0.06, and 0.50±0.06, respectively. The difference in cell apoptosis rate among the three groups was statistically significant ( F=24.531, P<0.05). The expression level of ROS in the Vec+4-HNE group was significantly higher than that in the simple 4-HNE group and the PSF+4-HNE group, with a statistically significant difference ( F=37.274, P<0.05). The relative expression levels of ER Ero-1 and PDI proteins in the normal group, simple 4-HNE group, Vec+4-HNE group, and PSF+4-HNE group were 1.25±0.03, 0.45±0.03, 0.63±0.03, 1.13±0.09, and 1.00±0.10, 0.27±0.10, 0.31±0.05, and 0.80±0.06, respectively. The relative expression levels of CHOP and GRP78 proteins were 0.55±0.06, 1.13±0.09, 0.90±0.06, 0.48±0.04 and 0.48±0.04, 1.25±0.03, 1.03±0.09, 0.50±0.06, respectively. The relative expression levels of Ero-1 ( F=43.164), PDI ( F=36.643), CHOP ( F=42.855), and GRP78 ( F=45.275) proteins in four groups were compared, and the differences were statistically significant ( P<0.05). Four groups of cells ER p-pERK/pERK ( F=35.755), peIF2 α/ The relative expression levels of eIF ( F=38.643) and ATF4 ( F=31.275) proteins were compared, and the differences were statistically significant ( P<0.05). Conclusion:PSF can inhibit cell apoptosis and ROS production induced by high concentration of 4-HNE, and its mechanism is closely related to restoring the homeostasis of ER and down-regulating the activation level of PERK/eIF2α/ATF4 pathway.

Cytopathic effect of rotavirus NSP4 86-175 protein on rat cardiomyocytes and the possible mechanism / 中华微生物学和免疫学杂志

Objective:To investigate the cytopathic effect of amino acids 86-175 of rotavirus non-structural protein 4 (NSP4 86-175) on rat cardiomyocytes and the possible mechanism. Methods:Rat H9C2 cardiomyocytes were treated with NSP4 86-175 protein. Changes in the growth and morphology of the cells were observed. The activity of LDH in the cell culture medium was detected. Fluo-3AM was used to label intracellular free calcium ions and the concentrations of calcium ions in rat cardiomyocytes with and without NSP4 86-175 treatment were detected by confocal laser microscopy. The expression of Bax, Bcl-2, caspase-3, 78 kDa glucose-regulated protein (GRP78), C/EBP homologous protein (CHOP) and caspase-12 at mRNA level was detected by real-time PCR. The expression of caspase-3, caspase-8, caspase-9, GRP78, CHOP and caspase-12 at protein level was detected by Western blot. Results:Normal cardiomyocytes showed a typical myoblast-like morphology, presenting as spindle-shaped cells with clear boundaries. Obvious cytopathic effect, vacuolar degeneration, shriveled and rounded cells, and cell fragmentation were observed after the treatment with purified NSP4 86-175 protein. The activity of LDH in cell culture medium was enhanced by NSP4 86-175 protein. NSP4 86-175 protein also enhanced the fluorescence of the calcium ions in rat cardiomyocytes, promoted cell apoptosis, up-regulated the expression of apoptotic factors including caspase-3, caspase-8, caspase-9 and Bax-2, and increased the expression of classical markers of endoplasmic reticulum stress such as GRP78, CHOP and caspase-12. Conclusions:NSP4 86-175 had a cytopathic effect on rat cardiomyocytes, which might be related to the induced intracellular calcium overload, endoplasmic reticulum stress, apoptosis and necrosis. These results might be used as theoretical reference for further study on rotavirus infection and myocardial injury.

Role of NORAD in ketamine-induced neurotoxicity in mouse hippocampal neurons: association with endoplasmic reticulum stress / 中华麻醉学杂志

Objective:To evaluate the role of long non-coding RNA (lncRNA) NORAD in ketamine-induced neurotoxicity in mouse hippocampal neurons and the relationship with endoplasmic reticulum stress.Methods:Primary mouse hippocampal neurons were isolated and cultured and then divided into 5 groups ( n=36 each) using a random number table method: control group (group C), ketamine group (group K), ketamine+ pcDNA3.1-NORAD plasmid group (group K+ NORAD), ketamine+ control plasmid group (group K+ NC), and ketamine+ NORAD+ tunicamycin group (group K+ NORAD+ TM). Group C was cultured with normal medium for 24 h. Group K was cultured with 40 μmol/L ketamine for 24 h. Group K+ NORAD was transfected with pcDNA3.1-NORAD overexpressing plasmid for 48 h, followed by treatment with 40 μmol/L ketamine for 24 h. Group K+ NC was transfected with pcDNA3.1 (+ ) plasmid for 48 h, followed by treatment with 40 μmol/L ketamine for 24 h. Group K+ NORAD+ TM was transfected with pcDNA3.1-NORAD overexpressing plasmid, 24 h later endoplasmic reticulum stress activator tunicamycin 1 μg/ml was added and the neurons were cultured for 24 h, and then ketamine 40 μmol/L was added and the neurons were cultured for another 24 h. Cell viability was detected by CCK-8 assay. The amount of lactate dehydrogenase (LDH) released was analyzed. Cell apoptosis was determined by TUNEL and flow cytometry methods. The NORAD expression was detected by real-time polymerase chain reaction. The expression of endoplasmic reticulum stress-related proteins protein kinase R-like ER kinase (PERK), phosphorylated PERK (p-PERK) and C/EBP homologous protein (CHOP) was detected by Western blot. Results:Compared with group C, the cell viability was significantly decreased, the amount of LDH released, percentage of apoptotic neurons and apoptosis rate were increased, NORAD expression was down-regulated, CHOP expression was up-regulated, and p-PERK/PERK was increased in group K ( P<0.05). Compared with group K, the cell viability was significantly increased, the amount of LDH released, percentage of apoptotic neurons and apoptosis rate were decreased, NORAD expression was up-regulated, CHOP expression was down-regulated, and p-PERK/PERK was decreased in group K+ NORAD ( P<0.05), and no significant change was found in the parameters mentioned above in group K+ NC ( P>0.05). Compared with group K+ NORAD, the cell viability was significantly decreased, the amount of LDH released, percentage of apoptotic neurons and apoptosis rate were increased, CHOP expression was up-regulated, and p-PERK/PERK was increased ( P<0.05), and no significant change was found in the NORAD expression in group K+ NORAD+ TM ( P>0.05). Conclusions:Over-expressed NORAD can alleviate ketamine-induced neurotoxicity in mouse hippocampal neurons via inhibition of the endoplasmic reticulum stress.

Role of caveolin 3 in diabetic cardiomyopathy in mice: relationship with endoplasmic reticulum stress / 中华麻醉学杂志

Objective:To evaluate the role of caveolin 3 (Cav-3) in diabetic cardiomyopathy and the relationship with endoplasmic reticulum stress in mice.Methods:This experiment was performed in two parts. Part Ⅰ in vivo experiment Sixteen clean-grade healthy adult male wild type mice weighing 18-20 g, were divided into 2 groups ( n=8 each) using a random number table method: control group(Control group) and diabetic cardiomyopathy group (DCM group). Another 8 Cav-3 KO mice were selected and served as Cav-3 KO + diabetic cardiomyopathy group (Cav-3 KO+ DCM group). Type 2 diabetic models were developed by high fat diet combined with intraperitoneal injection of streptozotocin (100 mg/kg). The left ventricular ejection fraction (EF), left ventricular short axis shortening rate (FS), left ventricular end-systolic diameter (LVESD) and left ventricular end-diastolic diameter (LVEDD) were measured by B ultrasound at 8 weeks. Then the mice were sacrificed, and the myocardial histomorphology was observed using HE staining. Part Ⅱ in vitro experiment HL-1 cardiomyocytes were divided into 3 groups ( n=6 each)using a random number table method: normal glucose group (NG group), high glucose group (HG group) and high glucose+ methyl-β-cyclodextrin group (HG+ β-CD group). The high glucose model was prepared by adding 50% glucose to a specialized culture medium until the final concentration reached 30 mmol/L, and HL-1 cardiomyocytes were continuously cultivated for 36 h. The cellular injury was assessed using LDH and CCK8 kits. The expression of endoplasmic reticulum stress-related proteins binding immunoglobulin protein (BiP), C/EBP-homologous protein (CHOP) and X-box binding protein 1 (XBP1-s) in myocardial tissues and HL-1 cells was detected by Western blot. Results:In vivo experiment Compared with Control group, the food intake, water intake, and heart mass/body mass were significantly increased, EF and FS were decreased, LVESD and LVEDD were increased, the expression of BiP, CHOP and XBP1-s was up-regulated, the expression of Cav-3 was down-regulated ( P<0.05), and the pathological damage was aggravated in DCM group and Cav-3 KO+ DCM group. Compared with DCM group, EF and FS were significantly decreased, LVESD and LVEDD were increased, the expression of BiP, CHOP and XBP1-s was up-regulated, the expression of Cav-3 was down-regulated ( P<0.05), and the pathological damage was aggravated in Cav-3 KO+ DCM group. In vitro experiment Compared with NG group, the cell viability was significantly decreased, LDH activity was increased, the expression of BiP, CHOP and XBP1-s was up-regulated, and the expression of Cav-3 was down-regulated in HG group and HG+ β-CD group ( P<0.05). Compared with HG group, the cell viability was significantly decreased, LDH was increased, the expression of BiP, CHOP and XBP1-s was up-regulated, and the expression of Cav-3 was down-regulated in HG+ β-CD group ( P<0.05). Conclusions:Down-regulation of Cav-3 expression aggravates myocardial injury in diabetes mellitus, and the mechanism is related to excessive activation of endoplasmic reticulum stress in mice.

Role of orphan nuclear receptor Nur77 in tunicamycin-induced injury to hippocampal neurons of mice: relationship with endoplasmic reticulum stress / 中华麻醉学杂志

Objective:To evaluate the role of orphan nuclear receptor Nur77 in tunicamycin(TM)-induced injury to hippocampal neurons and the relationship with endoplasmic reticulum stress in mice.Methods:Mouse HT22 cells were divided into 4 groups ( n=10 each) using a random number table method: control group (C group), Nur77 specific agonist Csn-B group (Csn-B group), endoplasmic reticulum stress inducer TM group (TM group), and TM+ Csn-B group. Cells in C group were cultured for 24 h under normal condition. In Csn-B group, Csn-B at a final concentration of 10 μg/ml was added to the culture medium, and the cells were incubated for 24 h. In TM group, TM at a final concentration of 200 ng/ml was added to the culture medium and the cells were incubated for 24 h to induce cell endoplasmic reticulum stress injury. Cells in TM+ Csn-B group were pretreated with Csn-B at a final concentration of 10 μg/ml for 15 min, then TM at a final concentration of 200 ng/ml was added, and the cells were co-incubated for 24 h. The cell viability was examined by CCK-8 assay kit after treatment in each group. The expression of endoplasmic reticulum stress-related protein CCAAT/enhancer-binding protein homologous protein (CHOP), glucose regulated protein 78 (GRP78)and apoptosis-associated protein Bcl-2, Bax, caspase-3 and cleaved-caspase-3 was detected by Western blot. Results:Compared with C group, the cell viability was significantly decreased, and the expression of CHOP, GRP78, Bax and cleaved-caspase-3 was up-regulated, and the expression of Bcl-2 and caspase-3 was down-regulated in TM group ( P<0.05 or 0.01). Compared with TM group, the cell viability was significantly increased, the expression of CHOP, GRP78, Bax and cleaved-caspase-3 was down-regulated, and the expression of Bcl-2 and caspase-3 was up-regulated in TM+ Csn-B group ( P<0.05 or 0.01). Conclusions:Orphan nuclear receptor Nur77 is involved in TM-induced injury to hippocampal neurons, which is related to activation of the endoplasmic reticulum stress in mice.

Research progress in the role of endoplasmic reticu-lum stress in cerebral ischemia-reperfusion injury / 中国药理学与毒理学杂志

During cerebral ischemia-reperfusion injury(CIRI),endoplasmic reticulum stress(ERS)leads to the development and progression of a series of deleterious physiological responses such as oxidative stress,dis-turbed calcium ion homeostasis,inflammation,apoptosis and autophagy.The unfolded protein response(UPR)is the main pathway activated by ERS,which regulates the expression of related factors within the endoplasmic reticu-lum(ER)and reduces protein translation levels.Prolonged and intense ERS may lead to cell death.Excessive ERS induces apoptosis mediated by C/EBP homologous pro-tein(CHOP),caspase-12 and c-Jun N-terminal kinase(JNK),thereby exacerbating brain damage.The thresh-old for the transition from adaptive mechanisms to apop-totic mechanisms during ERS depends on multiple fac-tors,including the cell status and environment,signaling pathway activity status,cumulative cascade,and the dose and time of ERS inducers.Further research is needed to completely elucidate the mechanism of ERS.Although the factors associated with the PERK and ATF6 path-ways are less extensively studied,their regulators still exist.Deficiency of protein tyrosine phosphatase 1B(PTP1B)leads to increased phosphorylation of PERK-eIF2α,while regulation of the proteasome and regulation of the XBP1 target gene WFS1 may also affect ATF6 sta-bility.In addition,differences in the structure,gene expres-sion,and metabolism of different types of neurons,as well as in their internal environment,may lead to differ-ences in their response to and impact on ERS.Differenc-es in UPR signaling pathways occur in hippocampal neurons and medial thalamic cells,and Purkinje cells and pyramidal cells may be more sensitive to ERS than other types of neurons.Our group's previous study found that ERS induced apoptosis in neurons after the onset of CIRI by regulating proteins such as GRP78,CHOP and caspase-12,but the effects of UPR activation on different cells need to be further investigated.

Investigation on endoplasmic reticulum stress mech-anism of ischemic stroke based on network pharma-cology / 中国药理学与毒理学杂志

OBJECTIVE To investigate the mecha-nism of endoplasmic reticulum stress in cerebral isch-emic stroke from a theoretical perspective based on net-work pharmacology.METHODS GeneCards and OMIM databases were used to screen out the related targets of cerebral ischemic stroke and endoplasmic reticulum stress.And Venny2.1.0 was used to draw Venn's diagram to get the intersecting genes between cerebral ischemic stroke and endoplasmic reticulum stress.String data-base was used to get the protein-protein interaction(PPI)diagram and cytoscape was used for visualization analy-sis.The key genes were screened out by cytohubba plug-in,and enrichment analysis was performed.RESULTS Network pharmacology showed that there were 3744 cerebral ischemic stroke-related targets and 8675 endo-plasmic reticulum stress-related targets.After screening,41 common targets were got.There were 37 nodes,390 edges in the PPI network,namely,there were 37 interact-ing proteins and 390 interacting relationships.The key genes identified by cytohubba plug-in were IL-6,ALB,INS,TNF,AKT1,CASP3,MAPK3,TP53,SIRT1 and VEGF.The biological process involves reaction to oxida-tive stress,the regulation of neuron death,and negative regulation of cell differentiation,etc.;cellular components were related to the membrane raft,smooth endoplasmic reticulum,endoplasmic reticulum lumen and other com-ponents;molecular function aspects were related to sig-naling receptor activator activity,chaperone binding and protease binding.Enrichment analysis of pathway revealed that the intersecting targets were involved in PI3K/Akt pathway and protein processing in endoplasmic reticulum,etc.CONCLUSION The endoplasmic reticu-lum stress in cerebral ischemic stroke is related to the bi-ological processes of reaction to oxidative stress,the reg-ulation of neuron death,and negative regulation of cell differentiation,the mechanism may be related to neuroin-flammation and apoptosis.

Research progress on the mechanism of action of endoplasmic reticulum stress inhibitors / 中国药理学与毒理学杂志

Endoplasmic reticulum stress(ERS)is closely related to the mechanisms of multiple diseases,and regulation of ERS has become a therapeutic target for several diseases.Previous studies by our group have demonstrated that ERS can be alleviated and neuronal cells can be protected by downregulating ERS-related proteins such as GRP78,caspase12 and caspase3.The research on ERS inhibitors has progressed rapidly in recent years,and they can be classified into various types such as molecular chaperones,small molecule compounds and natural products,such as 4-phenylbutyric acid(4-PBA),tauroursodeoxycholic acid(TUDCA)and tumor necrosis factor α-stimulating factor 6(TSG-6),etc.These inhibitors can regulate the ERS signaling pathway through different pathways,such as:silent information regulator 1(SIRT1)promotes the expression of anti-apop-totic proteins by inhibiting the PERK-eIF2α-ATF4-CHOP pathway,thus reducing apoptosis.In addition,SIRT1 deacetylates XBP-1,regulates the IRE1α-XBP1 signaling pathway,and inhibits the expressions of GRP78 and CHOP,thereby reducing the protein load of endoplasmic reticulum(ER)and alleviating ERS;PDE4 inhibitor regu-lates c-Jun-mediated apoptotic pathway,reduces the interaction between IRE1 and TRAF2,and attenuates the level of c-Jun phosphorylation,thereby restoring ER homeostasis.In addition,PDE4 inhibitor activates the antioxidant-acting Nrf-2 pathway,decreases the concen-tration of intracellular calcium ion and reduces the pro-duction of ROS;TSG-6 exerts anti-inflammatory effects by regulating the secretion of inflammatory factors through PERK-eIF-2α-NF-κB p65 and IRE1α-TRAF2-NF-κB p65 signaling pathways.In-depth exploration of the potential mechanism of action of ERS inhibitors is of great signifi-cance for finding ways to treat related diseases by regu-lating ERS.