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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.
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Objective@#Oxygen-glucose deprivation (OGD) is used to mimic ischemia in vitro to observe whether endoplasmic reticulum (ER) stress is involved in human dental pulp cells (hDPCs) after OGD and to better understand the regulatory mechanism of hDPCs in ischemia.@*Methods@# hDPCs were cultured in glucose-free DMEM and hypoxia (volume fraction 2% O2) to establish an hDPCs OGD model in vitro, which mimics hDPCs ischemia in vitro. hDPCs were divided into a control group (normal culture) and an experimental group (OGD 0 h, 2 h, 4 h and 8 h groups). After pretreatment with OGD for 0, 2, 4 and 8 h, hDPC viability was measured by methylthiazol tetrazolium (MTT) assay. qRT-PCR was used to detect the mRNA expression of ER stress markers [splicing x-box binding protein1 (sXBP1), activating transcription Factor 4 (ATF4) and C/EBP homologous protein (chop)]. Western blot was used to detect the protein expression of ER stress markers [phosphorylated RNA-activated protein kinase-like ER-resident kinase (p-perk) and phosphorylated eukaryotic initiation factor-2α (p-eIF2α)]. @*Results@#Compared with OGD 0 h group, cell viability of hDPCs decreased when exposed to OGD treatment for 2 h, 4 h and 8 h. Compared with the control group, mRNA expressions of ER stress makers (sXBP1, ATF4 and chop) and the protein expressions of ER stress protein markers (p-perk andp-eIF2α) increased in OGD treatment cells after 4 h were higher in OGD cells. The differences were statistically significant (P<0.05).@*Conclusion@#The results indicate that ER stress response is involved in hDPCs in OGD treatment.
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Polyphyllin I (PPI) purified from Polyphyllarhizomes displays puissant cytotoxicity in many kinds of cancers. Several researches investigated its anti-cancer activity. But novel mechanisms are still worth investigation. This study aimed to explore PPI-induced endoplasmic reticulum (ER) stress as well as the underlying mechanism in non-small cell lung cancer (NSCLC). Cell viability or colony-forming was detected by MTT or crystal violet respectively. Cell cycle, apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential were assessed by flow cytometry. Gene and protein levels were evaluated by qRT-PCR and immunoblotting respectively. Protein interaction was determined by immunoprecipitation or immunofluorescence assay. Gene overexpression or silencing was carried out by transient transfection with plasmids or small interfering RNAs. The Cancer Genome Atlas (TCGA) database was used for Gene Set Enrichment Analysis (GSEA), survival analysis, gene expression statistics or pathway enrichment assay. PPI inhibited the propagation of NSCLC cells, increased non-viable apoptotic cells, arrested cell cycle at G2/M phase, induced ROS levels but failed to decrease mitochondrial membrane potential. High levels of GRP78 indicates poor prognosis in NSCLC patients. PPI selectively suppressed unfolded protein response (UPR)-induced GRP78 expression, subsequently protected CHOP from GRP78-mediated ubiquitination and degradation. We demonstrated that the natural product PPI, obtained from traditional herbal medicine, deserves for further study as a valuable candidate for lead compound in the chemotherapy of NSCLC.
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AIM: To investigate the inhibitory effects of endoplasmic reticulum stress(ERS) and TRAIL on hepatic stellate cells in vitro and how their interaction affect the apoptosis of hepatic stellate cells. METHODS: Take thapsigargin (TG) as the endoplasmic reticulum stress-inducing agents, ursodeoxycholic acid (UDCA) for the endoplasmic reticulum stress inhibitors, SP600125 as a c-Jun N-terminal kinase(JNK) inhibitor, HSC-T6 cells were divided into normal control group, DMSO group, TRAIL group, TG group, UDCA group, siCHOP group and SP600125 group. The apoptosis rate of HSC-T6 cell was detected by flow cytometry. Small interference RNA was applied to silence C/EBP homologous protein(CHOP) gene. The protein expression levels of Caspase-8 were detected by immunohistochemistry method. The ERS marker protein CHOP and TRAIL receptor DR5 expression levels were determined by RT-PCR and Western blot. RESULTS:TG (1 μmol/L, 2 μmol/L, 4 μmol/L, 8 μmol/L, 16 μmol/L) increased cell apoptosis rate of HSC-T6. RT-PCR and Western blot showed that the endoplasmic reticulum stress protein marker CHOP could induce the upregulation of TRAIL receptor DR5 and Caspase-8. Moreover, siCHOP and the JNK inhibitor SP600125 could reduce the expression of DR5 and Caspase-8 in HSC cells. CONCLUSION: These results indicated that CHOP and JNK may be a potential factor regulating DR5 expression, and play an important role in the process of apoptosis of hepatic stellate cells.
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Objective: To investigate the effects and mechanisms of iridoid glycosides of Scrophulariae Radix (IGRS) via endoplasmic reticulum stress-mediated apoptosis pathway on the primary cortical neurons induced by oxygen glucose deprivation/reperfusion (OGD/R). Methods: Newborn SD rats were performed primary cortical neurons culture. And the primary cortical neurons were pretreated with IGRS (50, 100, and 200 μg/mL) for 24 h, and the in vitro model of oxygen-glucose deprivation/reoxygenation (OGD/R) was applied. The neurons purity and morphology were observed under inverted microscope, the cell viability was detected by MTT assay; the intracellular lactate dehydrogenase (LDH) level and superoxide dismutase (SOD) activity were detected by commercial kit. The apoptotic rate was detected by flow cytometry. The expression of C/EBP homologous protein (CHOP), glucose-regulated protein-78 (GRP78) and Caspase-12 protein were detected by western blotting. Results: The cultured primary cortical neurons were plump with high purity in good condition. Compared with the control group, the primary cortical neurons were retracted and rounded after OGD/R treatment, and the surface of the neurons became rough; The cell viability and SOD activity were significantly decreased; The LDH level and apoptotic rate were evidently increased; The expression of CHOP, Caspase-12, and GRP78 were significantly increased. Compared with the model group, IGRS could relieve neurons damage, increase cell viability and SOD activity, decrease LDH level and apoptotic rate, and down-regulate the expression of CHOP, Caspase-12, and GRP78. Conclusion: IGRS can antagonize the neuronal damage induced by OGD/R in primary cortical neurons, and its mechanism is related to the inhibition of endoplasmic reticulum stress-mediated apoptosis.
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AIM:To investigate the effects of Jiawei-Naotai formula (JWNTF) on ATF4/CHOP/Puma pathway in hippocampal neurons of ovariectomized female rats with cerebral ischemia.METHODS:The female rats were randomly divided into sham group, model group, JWNTF group and positive control group.The rats, expect in the sham group, were ovariectomized.The rats in each group were intragastric administration 11 days after ovariectomy.The rats in sham group and model group were given a gavage of 0.9％Na Cl, while the rats in other groups were administrated by corresponding therapy intragastrically for 3 d.The regional cerebral ischemia model was established by middle cerebral artery occlusion (MCAO) suture method 14 days after ovariectomy.The behaviors of the rats were evaluated 24 h after cerebral ischemia.The mRNA levels of Bax, Bcl-2 and caspase-3 were detected by RT-qPCR, and the protein expression of Bax, Bcl-2, caspase-3, ATF4, CHOP and Puma was determined by Western blot.RESULTS:Compared with sham group, the neurobehavioral scores significantly increased in other groups (P<0.05).Compared with model group, the neurobehavioral scores were significantly decreased in positive control group and JWNTF group (P<0.05).The protein expression of Bax, caspase-3, ATF4, CHOP and Puma, and the mRNA expression of Bax and caspase-3 in the hippocampus were much higher, and Bcl-2 was lower in model group than those in sham group (P<0.05).JWNTF significantly reduced the protein expression of Bax, caspase-3, ATF4 and CHOP, and the mRNA expression of Puma, Bax and caspase-3, and markedly increased the expression of Bcl-2 at mRNA and protein levels compared with model group.CONCLUSION:The JWNTF protects against brain damage induced by cerebral ischemia, which may be related to inhibitiing the expression of ATF4/CHOP/Puma pathway-related molecules at mRNA and protein levels.
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Objective To detect the activation levels of endoplasmic reticulum stress ATF6-CHOP pathway,and to investigate the molecular mechanism of tannic acid (TA) combined with cisplatin (CDDP) against hepatocellular carcinoma.Methods HepG2 cells were cultured with 180 μM TA or/and 0.9 μg/ml CDDP for 24 h or 48 h.The levels of ATF6 (ATF6α),ATF6B (ATF6β) and CHOP were analyzed by real-time fluorescence quantitative PCR (q-RT-PCR) and western blot.Results We found that after 24 h or 48 h,compared with the control group,ATF6 mRNA and protein levels,ATF6B protein level,CHOP mRNA and protein levels were significantly increased in the TA group,CDDP group or combination group (P ＜ 0.01 or P ＜ 0.05).Conclusion TA can combine with CDDP to increase the levels of endoplasmic reticulum stress ATF6-CHOP pathway,and the ATF6-CHOP pathway may be one of the molecular mechanisms synergistic anti-hepatocellular carcinoma effect of TA and CDDP on HepG2 cells.
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AIM:To investigate the inhibitory effect of ethanol extract of propolis (EEP) on oxidized low-density lipoprotein (ox-LDL)-induced vascular endothelial cell apoptosis and the underlying molecular mechanisms.METHODS:Human umbilical vein endothelial cells (HUVECs) were pretreated with EEP (7.5,15 and 30 mg/L) or 4-phenylbutyric acid (PBA,4 mmol/L) for 1 h and then treated with ox-LDL (100 mg/L) or tunicamycin (TM,4 mg/L) for 24 h.The cell viability and apoptosis were determined by MTT assay and Annexin V-FITC/PI double staining,respectively.The activities of lactic dehydrogenase (LDH) in the medium and caspase-3 in the HUVECs were measured.The protein and mRNA levels of C/EBP homologous protein (CHOP),a proapoptotic molecule under endoplasmic reticulum stress (ERS),and its downstream Bcl-2 were examined by Western blot and real-time PCR,respectively.RESULTS:Like PBA (an ERS inhibitor),EEP protected HUVECs from ox-LDL-induced injury in a dose-dependent manner,as assessed by the increased cell viability and the decreased LDH release,apoptotic rate and caspase-3 activation.The decrease in cell viability and the increases in LDH release,apoptotic rate and caspase-3 activation induced by TM,an ERS inducer,were also attenuated by EEP.Moreover,EEP suppressed ox-LDL-induced CHOP upregulation and Bcl-2 downregulation,and this effect was similar to that of PBA.Similarly,EEP significantly suppressed TM-induced CHOP upregulation both at the protein and mRNA levels.CONCLUSION:EEP may protect HUVECs from ox-LDL-induced apoptosis,and the mechanism is at least partially involved in suppressing CHOP-mediated ERS-associated apoptotic pathway.
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AIM:To investigate the inhibitory effect of ethanol extract of propolis (EEP) on oxidized low-density lipoprotein (ox-LDL)-induced vascular endothelial cell apoptosis and the underlying molecular mechanisms.METHODS:Human umbilical vein endothelial cells (HUVECs) were pretreated with EEP (7.5,15 and 30 mg/L) or 4-phenylbutyric acid (PBA,4 mmol/L) for 1 h and then treated with ox-LDL (100 mg/L) or tunicamycin (TM,4 mg/L) for 24 h.The cell viability and apoptosis were determined by MTT assay and Annexin V-FITC/PI double staining,respectively.The activities of lactic dehydrogenase (LDH) in the medium and caspase-3 in the HUVECs were measured.The protein and mRNA levels of C/EBP homologous protein (CHOP),a proapoptotic molecule under endoplasmic reticulum stress (ERS),and its downstream Bcl-2 were examined by Western blot and real-time PCR,respectively.RESULTS:Like PBA (an ERS inhibitor),EEP protected HUVECs from ox-LDL-induced injury in a dose-dependent manner,as assessed by the increased cell viability and the decreased LDH release,apoptotic rate and caspase-3 activation.The decrease in cell viability and the increases in LDH release,apoptotic rate and caspase-3 activation induced by TM,an ERS inducer,were also attenuated by EEP.Moreover,EEP suppressed ox-LDL-induced CHOP upregulation and Bcl-2 downregulation,and this effect was similar to that of PBA.Similarly,EEP significantly suppressed TM-induced CHOP upregulation both at the protein and mRNA levels.CONCLUSION:EEP may protect HUVECs from ox-LDL-induced apoptosis,and the mechanism is at least partially involved in suppressing CHOP-mediated ERS-associated apoptotic pathway.
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AIM:To study the effect of transient receptor potential channel 1 ( TRPC1) on the survival of hip-pocampal neurons in mice.METHODS:TRPC1 knockout mice and the control mice (6 months old) were used in this study.Immunofluorescence staining of neuron-specific marker NeuN, Nissl staining and TUNEL staining were performed to measure the changes of the neurons in hippocampal CA1, CA3 and dentate gyrus (DG).Western blot analysis was used to detect the levels of pro-apoptotic protein C/EBP homologous protein ( CHOP) and cleaved caspase-3.RESULTS:Immuno-fluorescence staining and Nissl staining showed that the number of neuronal cells was significantly decreased in hippocampal CA1, CA3 and DG of TRPC1 knockout mice compared with the control mice.TUNEL staining showed that the apoptosis neuronal cell number of the above areas in TRPC1 knockout mice was significantly increased compared with the control mice.The results of Western blot revealed that the levels of CHOP and cleaved caspase-3 were significantly increased in the hippocampus of TRPC1 knockout mice relative to the control mice.CONCLUSION:The depletion of TRPC1 induces neu-ronal loss through a mechanism of TRPC1-mediated apoptosis.
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OBJECTIVE To examine the reversal effect of desipramine (DMI) on resistance to temozolomide(TMZ) in U251/TR cells and explore its mechanism. METHODS U251/TR cells were exposed to DMI (20-80μmol · L-1) or TMZ (0.5-10 mmol · L-1) for 24 h, cell viability was determined by cell counting kit-8 assay with IC50 calculated. The cytotoxicity of U251/TR cells treated with TMZ (1 or 2 mmol·L-1) in combination with DMI (20, 30 or 40 μmol · L-1) for 24 h was detected using CCK-8 assay. Synergism between DMI and TMZ was analyzed by the JIN Zheng-jun method. Apoptosis of U251/TR cells induced by TMZ 1 mmol · L-1, DMI 30 μmol · L-1,or their combination was examined by Hoechst33258 stains and caspase 3 activity was detected by luminescence analysis. Expression of C/EBP homologous protein (CHOP) was measured using quantitative real-time PCR and Western blotting. The survival rate of U251/TR cells treated with TMZ 1 mmol·L-1 and/or DMI 30μmol·L-1 was also assessed after silencing CHOP expression by small interference RNA (siRNA). RESULTS DMI or TMZ alone inhibited the growth of U251/TR cells significantly in a concentration-dependent manner (r 2=0.983,0.982,P1.15), ie, compared with TMZ alone, TMZ (1 mmol·L-1) com?bined with DMI (30 μmol · L-1) produced significant nuclear fragmentation and condensation (P< 0.05). In addition, DMI and TMZ in combination activated caspase 3 activity in U251/TR cells (P<0.05). Knock?down of CHOP by specific siRNA attenuated the synergistic effect of DMI in the presence of TMZ, the survival rate of the combined drug group raised from 51.8%to 62.2%(P<0.05). CONCLUSION The results suggest that DMI reverse resistance of U251/TR cells to TMZ through activation of the CHOP-depend?ently apoptosis pathway.
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Objective To investigate the effect of CCK-8 on CHOP/caspase-11/caspase-1 expressions induced by LPS in RAW264.7 cells.Methods RAW264.7 cells were incubated with LPS and/or CCK-8 and/or CCK-8 1R blocking agent devazepide for indicated times .CHOP and caspase-11 protein expressions were determined by West-ern blot , caspase-1 activity was analyzed by kit , IL-1βexpression level was analyzed by ELISA .Results Both CHOP and caspase-11 expression were upregulated in LPS-activated RAW264.7 cell, which were inhibited by pre-treatment of CCK-8 .Pre-treatment of devazepide inhibited the effects of CCK-8 significantly .The same effects were found in caspase-1 activity and IL-1βexpression .Conclusions CCK-8 exerts an anti-inflammatory effect by inhib-iting CHOP/caspase-11/caspase-1 expressions induced by LPS in RAW264.7 cell.CCK 1R may contribute to the anti-inflammatory effect of CCK-8.
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Objective To investigate the effect and mechanism of phosphorylated protein kinase R-like ER kinase(p-PERK) and C/EBP homologous protein(CHOP) after hypoxic-ischemic brain damage ( HIBD) . Methods Neonatal 7-day-old Sprague Dawley rats were divided into sham-operation control group and HIBD group( n=30 per group) . Each group was divided into 0 h,6 h and 24 h subgroup after operation ( n=10 per group) . The ratio of apoptosis of brain cell was measured by flow cytometer and the expression of p-PERK and CHOP were detected by Western blot. Results (1)Apoptosis cell appeared at 6 h in HIBD group,the ratio of cell apoptosis was(2. 17 ± 0. 19)%. The apoptosis cell obvious increased at 24 h,the ratio of cell apoptosis was(13. 42 ± 0. 83)%. There was a significant increase in the ratio of apoptosis after HIBD 6 h and 24 h, as compared with sham-operation control group [ ( 0. 57 ± 0. 06 )%( P <0. 01 ) ] . ( 2 ) The expression of both p-PERK and CHOP was very low in sham-operation control group. In the HIBD group,the expression of both p-PERK and CHOP began to increase at 6 h and increased furthermore at HIBD 24 h. The differences in the expression levels of p-PERK and CHOP in HIBD group among different time points were significant( P<0. 01 ) . ( 3 ) The expression of p-PERK positively correlated with the expression of CHOP (r=0. 997,P< 0. 05). Conclusion With the emerging of apoptosis after HIBD,the expression of both p-PERK and CHOP increases. The imbalance in the expression of PERK induces the apoptosis of brain cells in the HIBD of neonatal rats by regulation of CHOP expression.
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Objective: To investigate the effect of stachydrine on the expression of protein kinase R-like endoplasmic reticulum kinase (PERK) in renal tissue of rats with unilateral ureteral obstruction (UUO). Methods: To establish the animal model of renal interstitial fibrosis induced by UUO. The rats were randomly divided into the Sham, model Enalapril, high-, mid-, and low-dose stachydrine groups. Rats were sacrificed to collect serum for determining the serum creatinine (Scr) and blood urea nitrogen (BUN) after day 14 of surgery. HE staining was used for observation of kidney pathological changes and the assessment of renal tubular damage indexes. Masson staining was applied to the semi-quantitative analysis of relative area of renal interstitial fibrosis (RIF) and degree of RIF. The expression of PERK, activiting transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP) was detected by immunohistochemical methods. Results: Compared with the model group, the levels of Bun, Scr, the tubular injury, the relative area of renal interstitial collagen, and the expression of PERK, ATF4, and CHOP was significantly reduced in the treatment groups (P < 0.05, 0.01). The high stachydrine was more effective than Enalapril in inhibiting RIF (P < 0.05). Conclusion: The stachydrine could inhibit the increasing expressions of ATF4 induced by PERK signaling pathway and CHOP activated by ATF4. The apoptosis are blocked to slow down the occurrence and development of RIF.
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AIM:To investigate the expression of C/EBP homologous protein (CHOP) and its correlation with proliferative/apoptotic ratio (PAR) in colorectal adenoma-carcinoma sequence under the same genetic background .ME-THODS:Four kinds of tissue samples under the same genetic background from 23 patients, including normal colorectal tissue, adenoma with low-grade intraepithelial neoplasia , adenoma with high-grade intraepithelial neoplasia and colorectal adenocarcinoma samples , were collected .TUNEL method and Ki-67 immunohistochemistry were applied to determine the PAR.The expression of CHOP was detected by immunohistochemistry SABC method .RESULTS: ( 1 ) Under the same genetic background , the level of CHOP expression is significantly higher in colorectal adenocarcinoma than that in the ade -noma with high-grade intraepithelial neoplasia , the adenoma with low-grade intraepithelial neoplasia and the normal muco-sa.The level of CHOP expression was significantly higher in the adenoma with high -grade intraepithelial neoplasia than that in the adenoma with low-grade intraepithelial neoplasia and the normal mucosa .The level of CHOP expression was signifi-cantly higher in the adenoma with low-grade intraepithelial neoplasia than that in normal mucosa .(2) Under the same ge-netic background , PAR was significantly higher in the colorectal adenocarcinoma than that in the adenoma with high -grade intraepithelial neoplasia , the adenoma with low-grade intraepithelial neoplasia and the normal mucosa .PAR was significant-ly higher in the adenoma with high-grade intraepithelial neoplasia than that in the adenoma with low-grade intraepithelial neoplasia and the normal mucosa .PAR was significantly higher in the adenoma with low-grade intraepithelial neoplasia than that in the normal mucosa.(3) CHOP levels were positively correlated with PAR in the adenoma with low-grade intraepi-thelial neoplasia , adenoma with high-grade intraepithelial neoplasia and colorectal adenocarcinoma .CONCLUSION:CHOP expression and PAR continuously increased and positively correlated along the adenoma -carcinoma sequence , indica-ting that endoplasmic reticulum stress mediates the carcinogenesis of colorectal adenomas .