BACKGROUNDLead exposure during pregnancy contributes to fetal abortion and/or teratogenesis. Endoplasmic reticulum (ER) apoptosis can be induced by various pathological conditions when ER function is disturbed. However, it is unclear whether ER stress and apoptosis play a role in the etiology of lead-exposed disease status. We aimed to investigate whether lead induced placental apoptosis and subsequent toxicity is initiated by ER apoptosis via caspase-12.

METHODSSixty-three female Wistar rats were exposed to lead in drinking water during various gestational periods. Blood lead level was determined by atomic absorption spectrophotometry. Placental cytoplasmic organelles were examined by electronic microscopy. Placental caspase-12 mRNA expression was evaluated by qRT-PCR. TUNEL assay was used to determine the placental apoptosis.

RESULTSLead exposure significant induced ER apoptosis compared to that of the controls (P < 0.05), accompanied with increased caspase-12 mRNA expression. Significant differences of caspase-12 mRNA expression levels were observed among the four groups (F = 13.78, P < 0.05). Apoptotic index (AI) was significantly increased in experimental groups compared to that of the controls (F = 96.15, P < 0.05). In lead-exposed groups, trophoblast cells underwent degeneration and fibrin deposition; Mitochondria were swollen and decreased in number; ER swelling, expansion, and vacuolization were observed.

CONCLUSIONLead exposure contributes to placental apoptosis, as well as increased caspase-12 mRNA expression, which in turn promoted ER stress.

Animals ; Apoptosis ; drug effects ; Endoplasmic Reticulum Stress ; drug effects ; Female ; Lead ; toxicity ; Placenta ; cytology ; ultrastructure ; Pregnancy ; Rats ; Rats, Wistar

OBJECTIVEWe investigated the role of endoplasmic reticulum stress (ERS) in silica-induced apoptosis in alveolar macrophages in vitro.

METHODSRAW264.7 cells were incubated with 200 μg/mL silica for different time periods. Cell viability was assayed by the MTT assay. Cell apoptosis was evaluated by DAPI staining, flow cytometry analysis, and Western blot analysis of caspase-3. Morphological changes in the endoplasmic reticulum were observed by transmission electron microscopy. The expression of ERS markers binding protein (BiP) and CCAAT-enhancer-binding protein homologous protein (CHOP) was examined by Western blotting and real-time PCR. As an inhibitor of ERS, 4-phenylbutyric acid (4-PBA) was used in the experiments.

RESULTSSilica exposure induced nuclear condensation and caspase-3 expression in RAW264.7 cells. The number of apoptotic cells increased after silica exposure in a time-dependent manner. Silica treatment induced expansion of the endoplasmic reticulum. In addition, the expression of BiP and CHOP increased in silica-stimulated cells. Furthermore, 4-PBA treatment inhibited silica-induced endoplasmic reticulum expansion and the expression of BiP and CHOP. Moreover, 4-PBA treatment attenuated nuclear condensation, reduced apoptotic cells, and downregulated caspase-3 expression in silica-stimulated cells.

CONCLUSIONSilica-induced ERS is involved in the apoptosis of alveolar macrophages.

Animals ; Apoptosis ; drug effects ; Butylamines ; Cell Survival ; drug effects ; Endoplasmic Reticulum Stress ; physiology ; Mice ; RAW 264.7 Cells ; Silicon Dioxide ; toxicity

This study is aimed to investigate the intervention effect and possible mechanism of ophiopogonin D( OPD) in protecting cardiomyocytes against ophiopogonin D'( OPD')-induced injury,and provide reference for further research on toxicity difference of saponins from ophiopogonins. CCK-8 assay was used to evaluate the effect of OPD and OPD' on cell viability. The effect of OPD on OPD'-induced cell apoptosis was measured by flow cytometry. Morphologies of endoplasmic reticulum were observed by endoplasmic reticulum fluorescent probe. PERK,ATF-4,Bip and CHOP mRNA levels were detected by Real-time quantitative polymerase chain reaction( PCR) analysis. ATF-4,phosphorylated PERK and e IF2α protein levels were detected by Western blot assay. RESULTS:: showed that treatment with OPD'( 6 μmol·L-1) significantly increased the rate of apoptosis; expressions of endoplasmic reticulum stress related genes were increased. The morphology of the endoplasmic reticulum was changed. In addition,different concentrations of OPD could partially reverse the myocardial cell injury caused by OPD'. The experimental results showed that OPD'-induced myocardial toxicity may be associated with the endoplasmic reticulum stress,and OPD may modulate the expression of CYP2 J3 to relieve the endoplasmic reticulum stress caused by OPD'.
Apoptosis ; Cardiotonic Agents ; pharmacology ; Cells, Cultured ; Endoplasmic Reticulum Stress ; drug effects ; Humans ; Myocytes, Cardiac ; drug effects ; Saponins ; pharmacology ; Spirostans ; pharmacology

BackgroundOxidized low-density lipoprotein (ox-LDL)-induced oxidative stress and endothelial apoptosis are essential for atherosclerosis. Our previous study has shown that ox-LDL-induced apoptosis is mediated by the protein kinase RNA-like endoplasmic reticulum kinase (PERK)/eukaryotic translation initiation factor 2α-subunit (eIF2α)/CCAAT/enhancer-binding protein homologous protein (CHOP) endoplasmic reticulum (ER) stress pathway in endothelial cells. Statins are cholesterol-lowering drugs that exert pleiotropic effects including suppression of oxidative stress. This study aimed to explore the roles of simvastatin on ox-LDL-induced ER stress and apoptosis in endothelial cells.

MethodsHuman umbilical vein endothelial cells (HUVECs) were treated with simvastatin (0.1, 0.5, or 2.5 μmol/L) or DEVD-CHO (selective inhibitor of caspase-3, 100 μmol/L) for 1 h before the addition of ox-LDL (100 μg/ml) and then incubated for 24 h, and untreated cells were used as a control group. Apoptosis, expression of PERK, phosphorylation of eIF2α, CHOP mRNA level, and caspase-3 activity were measured. Comparisons among multiple groups were performed with one-way analysis of variance (ANOVA) followed by post hoc pairwise comparisons using Tukey's tests. A value of P < 0.05 was considered statistically significant.

ResultsExposure of HUVECs to ox-LDL resulted in a significant increase in apoptosis (31.9% vs. 4.9%, P < 0.05). Simvastatin (0.1, 0.5, and 2.5 μmol/L) led to a suppression of ox-LDL-induced apoptosis (28.0%, 24.7%, and 13.8%, F = 15.039, all P < 0.05, compared with control group). Ox-LDL significantly increased the expression of PERK (499.5%, P < 0.05) and phosphorylation of eIF2α (451.6%, P < 0.05), if both of which in the control groups were considered as 100%. Simvastatin treatment (0.1, 0.5, and 2.5 μmol/L) blunted ox-LDL-induced expression of PERK (407.8%, 339.1%, and 187.5%, F = 10.121, all P < 0.05, compared with control group) and phosphorylation of eIF2α (407.8%, 339.1%, 187.5%, F = 11.430, all P < 0.05, compared with control group). In contrast, DEVD-CHO treatment had no significant effect on ox-LDL-induced expression of PERK (486.4%) and phosphorylation of eIF2α (418.8%). Exposure of HUVECs to ox-LDL also markedly induced caspase-3 activity together with increased CHOP mRNA level; these effects were inhibited by simvastatin treatment.

ConclusionsThis study suggested that simvastatin could inhibit ox-LDL-induced ER stress and apoptosis in vascular endothelial cells.

Apoptosis ; drug effects ; Cells, Cultured ; Endoplasmic Reticulum Stress ; drug effects ; Human Umbilical Vein Endothelial Cells ; drug effects ; metabolism ; Humans ; Lipoproteins, LDL ; pharmacology ; Oligopeptides ; pharmacology ; Simvastatin ; pharmacology

To study the protective effects of Wuzi Yanzong recipe on testis germ cell apoptosis in natural ageing rats through endoplasmic reticulum stress (ERS), 16-month-old male SPF grade SD rats were randomly divided into three groups: ageing model group, and low and high-dose Wuzi Yanzong recipe groups (WZ, 1 and 4 g·kg⁻¹), with 10 rats in each group. In addition, 2-month-old SD male rats were used as adult control group. The ageing model group and the adult control group were fed with normal diet for 4 months. WZ groups were given the medicated feed for 4 months. After fasting for 12 hours, the rats were put to death. Then, the testes were immediately collected. The change of testicular tissue morphology was observed by HE staining. The expression levels of ER stress-related proteins GRP78, p-PERK, p-eif2, ATF4, p-IRE1, XBP1, ATF6 and apoptosis-related proteins CHOP, caspase12 and p-JNK in testes were detected by Western blot. Compared with the ageing model group, Wuzi Yanzong recipe alleviated the morphological changes of testicular tissue. Western blot results showed that Wuzi Yanzong recipe significantly increased the expression levels of endoplasmic reticulum stress-related proteins GRP78, p-PERK, p-eif2, ATF4, p-IRE1, XBP1, ATF6 and significantly decreased the expression levels of endoplasmic reticulum-induced apoptosis-related proteins CHOP, caspase 12 and p-JNK. In conclusion, Wuzi Yanzong recipe can alleviate the ageing-related apoptosis of testicular germ cells in natural ageing rats by regulating endoplasmic reticulum stress.
Aging ; Animals ; Apoptosis ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Endoplasmic Reticulum Stress ; Germ Cells ; drug effects ; Male ; Rats ; Rats, Sprague-Dawley ; Testis ; drug effects

OBJECTIVEThe explore the mechanism responsible for diaphragmatic contractile and relaxation dysfunction in a rat model of sepsis.

METHODSThirty-six adult male Sprague-Dawley rats were randomized equally into a sham-operated group and two model groups of sepsis induced by cecal ligation and puncture (CLP) for examination at 6 and 12 h following CLP (CLP-6 h and CLP-12 h groups). The parameters of diaphragm contractile and relaxation were measured, and the calcium uptake and release rates of the diaphragmatic sarcoendoplasmic reticulum (SR) and the protein expressions of SERCA1, SERCA2 and RyR in the diaphragmatic muscles were determined.

RESULTSThe half-relaxation time of the diaphragm was extended in both the CLP-6 h and CLP-12 h groups with significantly reduced maximum tension declinerate and the peek uptake rate of SERCA (P<0.01). Diaphragmatic maximum twitch force development rate, the maximal twitch, tetanus tensions and the peek release rate of SR decreased only at 12h after CLP (P<0.01). The expression levels of SERCA1 protein decreased significantly in the diaphragmatic muscles at 12h following CLP (P<0.01) while SERCA2 expression level and SERCA activity showed no significant changes.

CONCLUSIONIn the acute stage of sepsis, both the contractile and relaxation functions of the diaphragm are impaired. Diaphragmatic relaxation dysfunction may result from reduced calcium uptake in the SR and a decreased level of SERCA1 in the diaphragmatic muscles.

Animals ; Calcium ; metabolism ; Cecum ; Diaphragm ; drug effects ; metabolism ; Endoplasmic Reticulum ; metabolism ; Ligation ; Male ; Muscle Contraction ; drug effects ; Rats ; Rats, Sprague-Dawley ; Sarcoplasmic Reticulum ; metabolism ; Sarcoplasmic Reticulum Calcium-Transporting ATPases ; metabolism ; Sepsis

OBJECTIVETo explore the effect of emodin on endoplasmic reticulum (ER) stress of pancreatic acinar AR42J cells.

METHODRat pancreatic acinar AR42J cells were cultured in 6-well plates, and divided into the normal control group, the model group (with the final concentration at 1 x 10(-7) mol · L(-1) for cerulean and lipopolysaccharide at 10 mg · L(-1)) and the emodin group (10, 20, 40 μmol · L(-1)). Cells in each group were cultured in three multiple pores for 24 h, and their supernate was removed after cell attachment. The normal control group was added with haploids, the model group was added with the modeling liquid for haploids, and the treatment groups were added with different concentrations of emodin at 15-20 min before the modeling liquid. The cells were continuously cultured for 3 h under 37 °C and 5% CO2. Their intracellular protease and lipase expressions were detected with kits. The cellular morphology was observed under optical microscope. The level of calcium in endoplasmic reticulum was measured under laser confocal microscopy. Western blot assay were used to determine the protein expression of ER-related signaling molecules.

RESULTEmodin could significantly inhibit levels of amylase, lipase and intracellular calcium and ER.

CONCLUSIONEmodin could reduce pancreatic acinar cell injury induced by the combination of cerulean and lipopolysaccharide. Its action mechanism is correlated with the inhibition of intracellular calcium overload and ER stress.

Animals ; Calcium ; metabolism ; Cell Line, Tumor ; Emodin ; pharmacology ; Endoplasmic Reticulum Stress ; drug effects ; Pancreatic Neoplasms ; metabolism ; pathology ; Rats ; Unfolded Protein Response ; drug effects

BACKGROUNDPodocyte apoptosis is recently indicated as an early phenomenon of diabetic nephropathy. Pancreatic β-cells exposed to saturated free fatty acid palmitate undergo irreversible endoplasmic reticulum (ER) stress and consequent apoptosis, contributing to the onset of diabetes. We hypothesized that palmitate could induce podocyte apoptosis via ER stress, which initiates or aggravates proteinuria in diabetic nephropathy.

METHODSPodocyte apoptosis was detected by 4',6-diamidio-2-phenylindole (DAPI) stained apoptotic cell count and Annexin V-PI stain. The expressions of ER molecule chaperone glucose-regulated protein 78 (GRP78), indicators of ER-associated apoptosis C/EBP homologous protein (CHOP), and Bcl-2 were assayed by Western blotting and real-time PCR. GRP78 and synaptopodin were co-localized by immunofluorescence stain.

RESULTSPalmitate significantly increased the percentage of cultured apoptotic murine podocytes time-dependently when loading 0.75 mmol/L (10 hours, 13 hours, and 15 hours compared with 0 hour, P < 0.001) and dose-dependently when loading palmitate ranging from 0.25 to 1.00 mmol/L for 15 hours (compared to control, P < 0.001). Palmitate time-dependently and dose-dependently increased the protein expression of GRP78 and CHOP, and decreased that of Bcl-2. Palmitate loading ranging from 0.5 to 1.0 mmol/L for 12 hours significantly increased mRNA of GRP78 and CHOP, and decreased that of Bcl-2 compared to control (P < 0.001), with the maximum concentration being 0.75 mmol/L. Palmitate 0.5 mmol/L loading for 3 hours, 8 hours, and 12 hours significantly increased mRNA of GRP78 and CHOP, and decreased that of Bcl-2 compared to 0 hour (P < 0.001), with the maximum effect at 3 hours. Confocal microscopy demonstrated that GRP78 expression was significantly increased when exposed to 0.5 mmol/L of palmitate for 8 hours compared to control.

CONCLUSIONPalmitate could induce podocyte apoptosis via ER stress, suggesting podocyte apoptosis and consequent proteinuria caused by lipotoxic free fatty acid could be ameliorated by relief of ER stress.

Apoptosis ; drug effects ; Cells, Cultured ; Endoplasmic Reticulum Stress ; physiology ; Heat-Shock Proteins ; analysis ; physiology ; Humans ; Insulin Resistance ; Palmitic Acid ; pharmacology ; Podocytes ; drug effects ; pathology

OBJECTIVETo study the role of lipid peroxidation injury and endoplasmic reticulum stress in Al-induced apoptosis.

METHODSNeurons from 0-3 day rats were cultured and treated with different concentrations of AlCl3.6H2O. Morphologic changes of neurons and endoplasmic reticulum were observed under fluorescent and transmission electron microscope; activities of superoxide dismutase (SOD), malondialdehyde (MDA) and ATP enzymes were detected.

RESULTSTypical morphologic changes in neurons apoptosis and endoplasmic reticulum were found under fluorescent and transmission electron microscope; SOD enzyme viability and ATP enzyme viability were significantly increased in the low-dosage group, but reduced in mid and high-dosage group (P < 0.01), whereas MDA levels decreased in the low-dosage group, but increased in mid and high-dosage group (P < 0.01).

CONCLUSIONAluminum may induce neurons apoptosis, and lipid peroxidation injury in endoplasmic reticulum plays an important role in the apoptosis progression.

Aluminum ; toxicity ; Animals ; Apoptosis ; drug effects ; Cells, Cultured ; Endoplasmic Reticulum Stress ; physiology ; Lipid Peroxidation ; physiology ; Neurons ; drug effects ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley

BACKGROUNDObstructive sleep apnea hypopnea syndrome, characterized by chronic intermittent hypoxia (CIH), is closely correlated with genioglossus dysfunction. CIH has been identified to mediate mitochondrial damage in genioglossus. It has been reported that endoplasmic reticulum stress (ERS) could be induced by mitochondrial dysfunction. This study aimed to investigate the role of ERS in CIH-induced genioglossus injury, as well as the possible intervention effect of adiponectin (Ad) supplement in rats.

METHODSForty-five male Wistar rats were randomly divided into three groups and submitted to room air (group A, n=15) as a control or CIH (groups B and C, n=15, respectively). Throughout the exposure period, intravenous Ad was given in group C; while intravenous normal saline was simultaneously given in groups A and B. After 35-day exposure, genioglossus samples were obtained from the pentobarbital-anaesthetized rats via surgical dissection, following blood sampling. Western blotting was applied to detect expressions of ERS signals and associated apoptotic pathways in genioglossus. Serum adiponectin levels were assessed via enzyme-linked immunosorbent assay (ELISA).

RESULTSSignificant hypoadiponectinemia was revealed in group B only (P < 0.05). Compared to those in groups A and C, expressions of markers involved in ERS, such as glucose regulated protein 78 (GRP78), p-PERK, phosphorylated eukaryotic initiation factor 2a (p-eIF2a), phosphorylated inositol-requiring transmembrane kinase/endoribonuclease 1a (p-IRE1a), spliced X-Box binding protein 1 (XBP1s) and activating transcription factor 6 (ATF6), were significantly enhanced in group B (all P < 0.01); while no significant difference was shown between groups A and C (all P > 0.05). ERSassociated apoptotic pathways were remarkably activated in group B. The involved markers detected as the expression of CCAAT/enhancer binding protein homologous protein (CHOP), B-cell lymphoma/leukemia associatied X protein (BAX) and caspase-12 were significantly elevated (all P < 0.01). Transvenous adiponectin supplement improved the above CIHinduced pathological changes in group C.

CONCLUSIONBeyond hypoadiponectinemia, CIH could enhance ERS and induce activation of ERS-associated apoptotic pathways in genioglossus, which could be significantly improved by adiponectin supplement.

Adiponectin ; administration & dosage ; therapeutic use ; Animals ; Endoplasmic Reticulum Stress ; drug effects ; Hypoxia ; drug therapy ; physiopathology ; Male ; Random Allocation ; Rats ; Rats, Wistar ; Sleep Apnea, Obstructive ; drug therapy