1.Mechanism of Gegen Qinlian Decoction in improving glucose metabolism in vitro and in vivo by alleviating hepatic endoplasmic reticulum stress.
Yue JIANG ; Li-Ke YAN ; Ying WANG ; Jun-Feng DING ; Zhong-Hua XU ; Can CUI ; Jun TU
China Journal of Chinese Materia Medica 2023;48(20):5565-5575
This study investigated the mechanism of Gegen Qinlian Decoction(GQD) in improving glucose metabolism in vitro and in vivo by alleviating endoplasmic reticulum stress(ERS). Molecular docking was used to predict the binding affinity between the main effective plasma components of GQD and ERS-related targets. Liver tissue samples were obtained from normal rats, high-fat-induced diabetic rats, rats treated with metformin, and rats treated with GQD. RNA and protein were extracted. qPCR was used to measure the mRNA expression of ERS marker glucose-regulated protein 78(GRP78), and unfolded protein response(UPR) genes inositol requiring enzyme 1(Ire1), activating transcription factor 6(Atf6), Atf4, C/EBP-homologous protein(Chop), and caspase-12. Western blot was used to detect the protein expression of GRP78, IRE1, protein kinase R-like ER kinase(PERK), ATF6, X-box binding protein 1(XBP1), ATF4, CHOP, caspase-12, caspase-9, and caspase-3. The calcium ion content in liver tissues was determined by the colorimetric assay. The ERS-HepG2 cell model was established in vitro by inducing with tunicamycin for 6 hours, and 2.5%, 5%, and 10% GQD-containing serum were administered for 9 hours. The glucose oxidase method was used to measure extracellular glucose levels, flow cytometry to detect cell apoptosis, glycogen staining to measure cellular glycogen content, and immunofluorescence to detect the expression of GRP78. The intracellular calcium ion content was measured by the colorimetric assay. Whereas Western blot was used to detect GRP78 and ERS-induced IRE1, PERK, ATF6, and eukaryotic translation initiation factor 2α(eIF2α) phosphorylation. Additionally, the phosphorylation levels of insulin receptor substrate 1(IRS1), phosphatidylinositol 3-kinase regulatory subunit p85(PI3Kp85), and protein kinase B(Akt), which were involved in the insulin signaling pathway, were also measured. In addition, the phosphorylation levels of c-Jun N-terminal kinases(JNKs), which were involved in both the ERS and insulin signaling pathways, were measured by Western blot. Molecular docking results showed that GRP78, IRE1, PERK, ATF4, and various compounds such as baicalein, berberine, daidzein, jateorhizine, liquiritin, palmatine, puerarin and wogonoside had strong binding affinities, indicating that GQD might interfere with ERS-induced UPR. In vivo results showed that GQD down-regulated the mRNA transcription of Ire1, Atf6, Atf4, Grp78, caspase-12, and Chop in diabetic rats, and down-regulated GRP78, IRE1, PERK, as well as ERS-induced apoptotic factors ATF4 and CHOP, caspase-12, caspase-9, and caspase-3, while up-regulating XBP1 to enhance adaptive UPR. In addition, GQD increased the calcium ion content in liver tissues, which facilitated correct protein folding. In vitro results showed that GQD increased glucose consumption in ERS-induced HepG2 cells without significantly affecting cell viability, increased liver glycogen synthesis, down-regulated ATF6 and p-eIF2α(Ser51), and down-regulated IRE1, PERK, and GRP78, as well as p-IRS1(Ser312) and p-JNKs(Thr183/Tyr185), while up-regulating p-PI3Kp85(Tyr607) and p-Akt(Ser473). These findings suggested that GQD alleviates excessive ERS in the liver, reduces insulin resistance, and improves hepatic glucose metabolism in vivo and in vitro.
Rats
;
Animals
;
Proto-Oncogene Proteins c-akt
;
Endoplasmic Reticulum Chaperone BiP
;
Caspase 3
;
Caspase 9
;
Diabetes Mellitus, Experimental
;
Caspase 12
;
Calcium/pharmacology*
;
Molecular Docking Simulation
;
Endoplasmic Reticulum Stress
;
Protein Serine-Threonine Kinases/genetics*
;
Liver
;
Apoptosis
;
Insulin
;
Glucose
;
Glycogen/pharmacology*
;
RNA, Messenger
2.Cordycepin, a metabolite of Cordyceps militaris, inhibits xenograft tumor growth of tongue squamous cell carcinoma in nude mice.
Qingwei ZHENG ; Yidan SHAO ; Wanting ZHENG ; Yingxu ZOU
Journal of Southern Medical University 2023;43(6):873-878
OBJECTIVE:
To evaluate the inhibitory effect of cordycepin on oral cancer xenograft in nude mice and explore the underlying mechanisms.
METHODS:
Sixteen BALB/c mice bearing subcutaneous human tongue squamous cell carcinoma (TSCC) TCA-8113 cell xenografts were randomized into model group and cordycepin treatment group for daily treatment with saline and cordycepin for 4 weeks. After the treatment, the tumor xenografts were dissected and weighed to assess the tumor inhibition rate. Histological changes in the heart, spleen, liver, kidney, and lung of the mice were evaluated with HE staining, and tumor cell apoptosis was examined using TUNEL staining; The expressions of Bax, Bcl-2, GRP78, CHOP, and caspase-12 in the xenografts were detected using RT-qPCR and Western blotting.
RESULTS:
Cordycepin treatment resulted in a tumor inhibition rate of 56.09% in the nude mouse models, induced obvious changes in tumor cell morphology and significantly enhanced apoptotic death of the tumor cells without causing pathological changes in the vital organs. Cordycepin treatment also significantly reduced Bcl-2 expression (P < 0.05) and increased Bax, GRP78, CHOP, and caspase-12 expressions at both the RNA and protein levels in the tumor tissues.
CONCLUSION
Cordycepin treatment can induce apoptotic death of TCA-8113 cell xenografts in nude mice via the endogenous mitochondrial pathway and endoplasmic reticulum stress pathways.
Humans
;
Animals
;
Mice
;
Carcinoma, Squamous Cell/drug therapy*
;
Heterografts
;
Mice, Nude
;
Tongue Neoplasms/drug therapy*
;
Cordyceps
;
Caspase 12
;
Endoplasmic Reticulum Chaperone BiP
;
bcl-2-Associated X Protein
;
Tongue
3.Effect of moxibustion at "oppositely-located points" on neurogenic bladder after spinal cord injury and endoplasmic reticulum stress pathway in rats.
Wei WEI ; Zhi-Xin YANG ; Tian-Yu WANG ; Tao-Tao CUI ; Jian-Shuang CHEN ; Chao ZHANG ; Na LI ; Li-Qun REN
Chinese Acupuncture & Moxibustion 2022;42(4):413-418
OBJECTIVE:
To observe the effect of moxibustion at oppositely-located points "Mingmen" (GV 4) and "Shenque" (CV 8) on the motor function of the hind limbs and bladder function in rats with neurogenic bladder after suprasacral spinal cord injury (SCI), so as to explore the effect of this therapy on bladder tissue apoptosis mediated by endoplasmic reticulum stress pathway.
METHODS:
Twenty-eight female Wistar rats were randomly divided into a sham-operation group (8 rats) and a model establishment group (20 rats). Using the modified Allen's method, the spinal cord of T10 segment was injured to establish a neurogenic bladder model in the model establishment group. Sixteen rats were modeled successfully and then divided into a model group (8 rats) and a moxibustion group (8 rats). In the moxibustion group, 2 h after consciousness regaining from modeling anesthesia, moxibustion was exerted at "Shenque" (CV 8) and "Mingmen" (GV 4), 2 cones at each acupoint in one intervention. The intervention was administered once every two days and 5-time intervention was required totally. After intervention, Basso, Beattie and Bresnahan locomotor rating scale (BBB) score for the motor function of the hind limbs, and the urodynamics indexes (maximum bladder capacity, urine leakage pressure and bladder compliance) were compared among groups. HE staining method was adopted to observe the morphological changes of bladder tissue. With Western blot method and real-time PCR assay, the protein and mRNA expressions of the endoplasmic reticulum stress-related genes (glucose- regulated protein 78 [GRP78], activating transcription factor 4 [ATF4] and cysteinyl aspartate specific proteinase-12 [Caspase-12]) were determined.
RESULTS:
The transitional epithelial cells were arranged irregularly, the bladder wall was getting thinner, and the cellular vacuolar degeneration and neutrophil infiltration were found in the model group. Whereas, compared with the model group, in the moxibustion group, the arrangement of transitional epithelial cells was clear and continuous in layers, the cellular vacuolar degeneration was mild and the infiltration presented in a small amount of neutrophil granulocytes. Compared with the sham-operation group, in the model group, the BBB score was reduced (P<0.01), the maximum bladder capacity and bladder compliance were increased (P<0.01), and the protein expression levels of GRP78, ATF4 and Caspase-12, as well as mRNA expressions were all increased (P<0.01). In comparison with the model group, in the moxibustion group, BBB score was increased (P<0.01), the maximum bladder capacity and bladder compliance were decreased (P<0.01), and the protein and mRNA expression levels of GRP78, ATF4 and Caspase-12 were all decreased (P<0.01).
CONCLUSION
Moxibustion at the "oppositely-located points" improves the urination function, alleviate urine retention in neurogenic bladder rats after spinal cord injury. The underlying mechanism may be related to the down-regulation of the expressions of GRP78, ATF4 and Caspase-12 in the endoplasmic reticulum stress pathway of the bladder tissues, and thus to alleviate the apoptosis of bladder tissue.
Animals
;
Caspase 12/genetics*
;
Electroacupuncture
;
Endoplasmic Reticulum Stress
;
Female
;
Moxibustion
;
RNA, Messenger
;
Rats
;
Rats, Sprague-Dawley
;
Rats, Wistar
;
Spinal Cord
;
Spinal Cord Injuries/therapy*
;
Urinary Bladder, Neurogenic/therapy*
4.Mechanism of atractylenolide Ⅲ in alleviating H9c2 cell apoptosis through ROS/GRP78/caspase-12 signaling pathway based on molecular docking.
Meng-Yu ZUO ; Tong-Juan TANG ; Peng ZHOU ; Xiang WANG ; Rui DING ; Jin-Fan GU ; Jian CHEN ; Liang WANG ; Juan YAO ; Xiang-Yang LI ; Jin-Ling HUANG
China Journal of Chinese Materia Medica 2022;47(16):4436-4445
This study aims to investigate the effect of atractylenolide Ⅲ(ATL-Ⅲ) on hydrogen peroxide(H_2O_2)-induced endoplasmic reticulum stress and apoptosis of H9 c2 cells via the ROS/GRP78/caspase-12 signaling pathway.The binding activity of ATL-Ⅲ to GRP78 was determined by molecular docking.The result showed that ATL-Ⅲ had a good binding activity to GRP78, and the binding activity of ATL-Ⅲ was stronger than that of its specific inhibitor.The endoplasmic reticulum stress model of H9 c2 was established by H_2O_2(100 μmol·L~(-1)) treatment.Five groups were designed: blank control group, model group, and ATL-Ⅲ(15, 30, and 60 μmol·L~(-1)) groups.Apoptosis was detected by Hoechst/PI double staining and flow cytometry.The levels of superoxide dismutase(SOD), malondialdehyde(MDA), and lactate dehydrogenase(LDH) were measured by colorimetry.The levels of reactive oxygen species(ROS) and calcium(Ca~(2+)) in cytoplasm were determined by the fluorescence probe DCFH-DA and the calcium fluorescence probe Flou-4, respectively.The protein levels of GRP78, caspase-12, and caspase-3 were determined by Western blot, and the mRNA levels of GRP78 and caspase-12 by RT-qPCR.N-acetyl-L-cysteine(NAC) and 4-phenylbutyric acid(4-PBA) were respectively used to inhibit ROS and GRP78, and then the mechanism of ATL-Ⅲ in protecting the cells from endoplasmic reticulum stress induced by H_2O_2 were deduced.ATL-Ⅲ(15, 30, and 60 μmol·L~(-1)) decreased the apoptosis rate and ROS, MDA, and LDH levels(P<0.01), increased the SOD activity(P<0.01), and down-regulated the protein levels of GRP78, caspase-12, and caspase-3 and the mRNA levels of GRP78 and caspase-12(P<0.05).The addition of NAC decreased the apoptosis rate and ROS, MDA, GRP78, caspase-12, and caspase-3 levels(P<0.01), while it elevated the SOD level(P<0.01).The addition of 4-PBA also decreased the apoptosis rate and the levels of GRP78, caspase-12, caspase-3, and Ca~(2+)(P<0.01).The effect of inhibitors were consistent with that of ATL-Ⅲ.In conclusion, ATL-Ⅲ can protect H9 c2 cardiomyocytes by regulating ROS/GRP78/caspase-12 signaling pathway to inhibit H_2O_2-induced endoplasmic reticulum stress and apoptosis.
Apoptosis
;
Calcium/pharmacology*
;
Caspase 12/metabolism*
;
Caspase 3/metabolism*
;
Endoplasmic Reticulum Chaperone BiP
;
Endoplasmic Reticulum Stress
;
Lactones
;
Molecular Docking Simulation
;
RNA, Messenger
;
Reactive Oxygen Species/metabolism*
;
Sesquiterpenes
;
Signal Transduction
;
Superoxide Dismutase/metabolism*
5.G protein-coupled estrogen receptor alleviates cerebral ischemia-reperfusion injury through inhibiting endoplasmic reticulum stress.
Zi-Wei HAN ; Li-Cang ZHU ; Yue-Chen CHANG ; Ying ZHOU ; Jia-An ZONG ; Ke-Tao MA ; Jun-Qiang SI ; Li LI
Acta Physiologica Sinica 2019;71(4):527-536
The aim of this study was to investigate whether G protein-coupled estrogen receptor (GPER) could alleviate hippocampal neuron injury under cerebral ischemia-reperfusion injury (CIRI) by acting on endoplasmic reticulum stress (ERS). The CIRI animal model was established by middle cerebral artery occlusion (MCAO). Female ovariectomized (OVX) Sprague-Dawley (SD) female rats were randomly divided into 4 groups: control, ischemia-reperfusion injury (MCAO), vehicle (MCAO+DMSO), and GPER-specific agonist G1 (MCAO+G1) groups. The neurobehavioral score was assessed by the Longa score method, the morphological changes of the neurons were observed by the Nissl staining, the cerebral infarction was detected by the TTC staining, and the neural apoptosis in the hippocampal CA1 region was detected by TUNEL staining. The distribution and expression of GRP78 (78 kDa glucose-regulated protein 78) in the hippocampal CA1 region were observed by immunofluorescent staining. The protein expression levels of GRP78, Caspase-12, CHOP and Caspase-3 were detected by Western blot, and the mRNA expression levels of GRP78, Caspase-12, and CHOP were detected by the real-time PCR. The results showed that the neurobehavioral score, cerebral infarct volume, cellular apoptosis index, as well as GRP78, Caspase-12 and CHOP protein and mRNA expression levels in the MCAO group were significantly higher than those of control group. And G1 reversed the above-mentioned changes in the MCAO+G1 group. These results suggest that the activation of GPER can decrease the apoptosis of hippocampal neurons and relieve CIRI, and its mechanism may involve the inhibition of ERS.
Animals
;
Apoptosis
;
Brain Ischemia
;
CA1 Region, Hippocampal
;
cytology
;
Caspase 12
;
metabolism
;
Caspase 3
;
metabolism
;
Endoplasmic Reticulum Stress
;
Female
;
Heat-Shock Proteins
;
metabolism
;
Neurons
;
cytology
;
Random Allocation
;
Rats
;
Rats, Sprague-Dawley
;
Receptors, Estrogen
;
physiology
;
Receptors, G-Protein-Coupled
;
agonists
;
Reperfusion Injury
;
Transcription Factor CHOP
;
metabolism
6.Puromycin aminonucleoside triggers apoptosis in podocytes by inducing endoplasmic reticulum stress.
Seo Yoon MIN ; Dong Soo HA ; Tae Sun HA
Kidney Research and Clinical Practice 2018;37(3):210-221
BACKGROUND: Puromycin aminonucleoside (PAN) is a known podocytotoxin. PAN-induced nephrosis is a widely used animal model for studying human idiopathic nephrotic syndrome. Abnormal protein accumulation associated with podocyte-specific endoplasmic reticulum (ER) stress damages cells structurally and functionally, which in turn induces apoptosis and severe proteinuria. In the present study, we investigated the effect of PAN on ER stress and apoptosis in podocytes in vitro. METHODS: Mouse podocytes were cultured and treated with various concentrations of PAN. ER stress markers were then evaluated by western blotting, and apoptosis was evaluated by fluorescence-activated cell sorting (FACS) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays. RESULTS: PAN treatment increased ER stress markers such as activating transcription factor (ATF) 6α and caspase-12 in a dose-dependent manner at 12 and 24 hours, respectively. These markers were reduced by chemical chaperones, such as sodium 4-phenylbutyric acid and tauroursodeoxycholic acid. PAN treatment also increased 78 kD glucose-regulated protein (GRP78)/binding immunoglobulin protein (BiP) at the earlier stage of 12 hours. PAN significantly induced podocyte apoptosis in concentration- and time-dependent manners, as seen using FACS and TUNEL assays. This result was improved by Nox4 siRNA, ATF6 siRNA, and chemical chaperones. LY294002, a PI3-kinase inhibitor, significantly boosted ER stress and apoptosis. PAN-induced ER stress increased oxidative stress and subsequently induced apoptosis, and could be mitigated by inhibition of PI3-kinase signaling. CONCLUSION: Our findings suggest that PAN induces ER stress in podocytes mainly through the GRP78/BiP, ATF6α, and caspase-12 pathways, which trigger apoptosis via induction of oxidative stress. This stress is mitigated by inhibiting PI3-kinase signaling.
Animals
;
Apoptosis*
;
Blotting, Western
;
Caspase 12
;
DNA Nucleotidylexotransferase
;
Endoplasmic Reticulum Stress*
;
Endoplasmic Reticulum*
;
Flow Cytometry
;
Humans
;
Immunoglobulins
;
In Situ Nick-End Labeling
;
In Vitro Techniques
;
Mice
;
Models, Animal
;
Nephrosis
;
Nephrotic Syndrome
;
Oxidative Stress
;
Phosphatidylinositol 3-Kinases
;
Podocytes*
;
Proteinuria
;
Puromycin Aminonucleoside*
;
Puromycin*
;
RNA, Small Interfering
;
Sodium
;
Transcription Factors
7.Effect of naringin on oxidative stress and endoplasmic reticulum stress in diabetic cardiomyopathy.
Yu-Fei ZHANG ; Na-Na MENG ; Hou-Zhong LI ; Yi-Jie WEN ; Jie-Ting LIU ; Chun-Lei ZHANG ; Xiao-Huan YUAN ; Xiu-Dong JIN
China Journal of Chinese Materia Medica 2018;43(3):596-602
To explore the protective effect of naringin(Nar) on the injury of myocardium tissues induced by streptozotocin(STZ) in diabetic rats and the relationship with oxidative stress and endoplasmic reticulum stress(ERS), the male SD rats were intraperitoneally injected with streptozotocin(STZ, 60 mg·kg⁻¹) to establish the diabetic rat model and then randomly divided into the type 1 diabetic rat group(T1DR), the low-dose Nar group(Nar25), the middle-dose Nar group(Nar50) and the high-dose Nar group(Nar100). The normal rats were designed as control group(Con). Nar25, Nar50, Nar100 groups were orally administered with Nar at the doses of 25.0, 50.0, 100.0 mg·kg⁻¹ per day, respectively, while the normal group and the T1DR group were orally administered with saline. At the 8th week after treatment, fasting plasma glucose and heart mass index were measured. The pathological changes in myocardial tissues were observed by microscope. The cardiac malondialdehyde(MDA) level and superoxide dismutase(SOD) activities were measured. The gene and protein expressions of glucose-regulated protein 78(GRP78), C/EBP homologous protein(CHOP), cysteinyl aspartate-specific proteinase 12(caspase 12) were detected by qRT-PCR and Western blot. According to the results, compared with control group, the myocardial structure was damaged, the content of MDA was increased, while the activities of SOD were decreased(<0.05) in T1DR group. GRP78, CHOP and caspase 12 mRNA and protein expressions were increased significantly in T1DR group(<0.05, <0.01). Compared with T1DR group, myocardial structure damage was alleviated in Nar treatment group. The content of MDA was decreased, while the activities of SOD were increased significantly. The mRNA and protein expressions of GRP78, CHOP and caspase 12 were increased, especially in middle and high-dose groups(<0.05, <0.01). After treatment with Nar for 8 weeks, myocardial structure damage was obviously alleviated in Nar treatment groups. The content of MDA was decreased, while the activities of SOD were increased significantly in myocardial tissues. The mRNA and protein expressions of GRP78, CHOP and caspase 12 were increased, especially in middle and high-dose groups(<0.05, <0.01). The findings suggest that Nar may protect myocardium in diabetic rats by reducing mitochondrial oxidative stress injuries and inhibiting the ERS-mediated cell apoptosis pathway.
Animals
;
Apoptosis
;
Cardiotonic Agents
;
pharmacology
;
Caspase 12
;
metabolism
;
Diabetes Mellitus, Experimental
;
Diabetic Cardiomyopathies
;
drug therapy
;
Endoplasmic Reticulum Stress
;
drug effects
;
Flavanones
;
pharmacology
;
Heat-Shock Proteins
;
metabolism
;
Male
;
Malondialdehyde
;
metabolism
;
Oxidative Stress
;
drug effects
;
Rats
;
Rats, Sprague-Dawley
;
Superoxide Dismutase
;
metabolism
;
Transcription Factor CHOP
;
metabolism
8.Effects of excessive endoplasmic reticulum stress on lung ischemia/reperfusion induced myocardial injury in mice.
Bing-Qian XIANG ; Hui GAO ; Mao-Lin HAO ; Yong-Yue DAI ; Wan-Tie WANG
Chinese Journal of Applied Physiology 2018;34(1):8-13
OBJECTIVE:
To investigate the effects of excessive endoplasmic reticulum stress on lung ischemia/reperfusion (I/R) induced myocardial injury in mice.
METHODS:
Forty healthy SPF male C57BL/6J mice were divided into 4 groups randomly (=10):sham operation group (Sham group), lung I/R group (I/R group), endoplasmic reticulum stress (ERS) pathway agonist Tunicamycin group (TM) and ERS inhibitor 4-phenyl butyric acid group (4-PBA). The model of lung I/R injury was established by clamping the left hilum of lung for 30 min followed by 180 min of reperfusion. In sham group, only sternotomy was performed, the hilum of lung was not clamped, and the mice were mechanically ventilated for 210 min. In TM and 4-PBA groups, TM 1mg/kg and 4-PBA 400 mg/kg were injected intraperitoneally, respectively, at 30 min before establishment of the model. At 180 min of reperfusion, blood samples were collected from the orbit for determination of myocardial enzyme. The animals were then sacrificed, and hearts were removed for determination of light microscope, TUNEL, Caspase 3 enzymatic activity, real-time polymerase chain reaction and Western blot.
RESULTS:
Compared with sham group, the cardiomyocytes had obvious damage under light microscope, and the serum creatine kinase-MB (CK-MB) and lactic dehydrogenase (LDH) activities, apoptosis index and Caspase 3 enzymatic activity were increased significantly, the expressions of p-Jun N-terminalkinase(p-JNK), Caspase 12, CCAAT/enhancer-binding protein homologous protein (CHOP) and glucose regulated protein 78(GRP78) protein and mRNA were up-regulated in I/R, TM and 4-PBA groups (<0.01). Compared with I/R group, the cardiomyocytes damage was obvious under light microscope, and the serum CK-MB and LDH activities, apoptosis index and Caspase 3 enzymatic activity were increased significantly, the expressions of p-JNK, Caspase 12, CHOP and GRP78 protein and mRNA were up-regulated in group TM; while all above changes were relieved in group 4-PBA (<0.01). Compared with TM group, the cardiomyocytes damage was relieved under light microscope, and the serum CK-MB and LDH activities, apoptosis index and Caspase 3 enzymatic activity were decreased significantly, the expressions of p-JNK, Caspase 12,CHOP and GRP78 protein and mRNA were down-regulated in group 4-PBA.
CONCLUSIONS
The excessive endoplasmic reticulum stress participates in myocardial injury induced by lung ischemia/reperfusion (I/R) and inhibit excessive endoplasmic reticulum stress response can relieved myocardial injury.
Animals
;
Apoptosis
;
Caspase 12
;
Caspase 3
;
metabolism
;
Creatine Kinase, MB Form
;
blood
;
Endoplasmic Reticulum Stress
;
Heart Injuries
;
physiopathology
;
Heat-Shock Proteins
;
metabolism
;
L-Lactate Dehydrogenase
;
blood
;
Lung
;
pathology
;
MAP Kinase Kinase 4
;
metabolism
;
Male
;
Mice
;
Mice, Inbred C57BL
;
Myocardium
;
pathology
;
Random Allocation
;
Reperfusion Injury
;
Transcription Factor CHOP
;
metabolism
9.Endoplasmic Reticulum Stress Induces the Early Appearance of Pro-apoptotic and Anti-apoptotic Proteins in Neurons of Five Familial Alzheimer's Disease Mice.
Hui SHEN ; Xiao-Dong PAN ; Jing ZHANG ; Yu-Qi ZENG ; Meng ZHOU ; Lu-Meng YANG ; Bing YE ; Xiao-Man DAI ; Yuan-Gui ZHU ; Xiao-Chun CHEN ;
Chinese Medical Journal 2016;129(23):2845-2852
BACKGROUNDAmyloid β (Aβ) deposits and the endoplasmic reticulum stress (ERS) are both well established in the development and progression of Alzheimer's disease (AD). However, the mechanism and role of Aβ-induced ERS in AD-associated pathological progression remain to be elucidated.
METHODSThe five familial AD (5×FAD) mice and wild-type (WT) mice aged 2, 7, and 12 months were used in the present study. Morris water maze test was used to evaluate their cognitive performance. Immunofluorescence and Western blot analyses were used to examine the dynamic changes of pro-apoptotic (CCAAT/enhancer-binding protein homologous protein [CHOP] and cleaved caspase-12) and anti-apoptotic factors (chaperone glucose-regulated protein [GRP] 78 and endoplasmic reticulum-associated protein degradation-associated ubiquitin ligase synovial apoptosis inhibitor 1 [SYVN1]) in the ERS-associated unfolded protein response (UPR) pathway.
RESULTSCompared with age-matched WT mice, 5×FAD mice showed higher cleaved caspase-3, lower neuron-positive staining at the age of 12 months, but earlier cognitive deficit at the age of 7 months (all P < 0.05). Interestingly, for 2-month-old 5×FAD mice, the related proteins involved in the ERS-associated UPR pathway, including CHOP, cleaved caspase-12, GRP 78, and SYVN1, were significantly increased when compared with those in age-matched WT mice (all P < 0.05). Moreover, ERS occurred mainly in neurons, not in astrocytes.
CONCLUSIONSThese findings suggest that compared with those of age-matched WT mice, ERS-associated pro-apoptotic and anti-apoptotic proteins are upregulated in 2-month-old 5×FAD mice, consistent with intracellular Aβ aggregation in neurons.
Alzheimer Disease ; metabolism ; Amyloid beta-Peptides ; metabolism ; Animals ; Apoptosis ; physiology ; Blotting, Western ; Caspase 12 ; metabolism ; Endoplasmic Reticulum Stress ; physiology ; Frontal Lobe ; metabolism ; Heat-Shock Proteins ; metabolism ; Immunohistochemistry ; Mice ; Mice, Transgenic ; Neurons ; metabolism ; Transcription Factor CHOP ; metabolism ; Ubiquitin-Protein Ligases ; metabolism ; Unfolded Protein Response ; physiology
10.Advanced glycated albumin induces macrophage apoptosis via activating caspase-12 pathway.
Jin-Guo LI ; Qi HAO ; Ying-Xue LIU ; Peng LI ; Peng LI ; Xia-Yan SHAO ; Hua TIAN ; Yong-Qi FANG ; Shu-Tong YAO
Acta Physiologica Sinica 2016;68(6):733-739
The purpose of the present study was to investigate the effect of advanced glycated albumin (AGE-alb) on the activation of caspase-12, a key molecule in endoplasmic reticulum stress (ERS)-associated apoptotic pathway, and to elucidate the underlying molecular mechanisms of macrophage apoptosis. RAW264.7 macrophages were treated with AGE-alb (2, 4 and 6 g/L), control albumin (C-alb, 4 g/L), tunicamycin (TM, 4 mg/L), or pretreated with 4-phenylbutyric acid (PBA, 5 mmol/L) for 1 h and then treated with AGE-alb (4 g/L). After incubation for 24 h, the cell viability and apoptosis were determined by using MTT assay and TUNEL detection kit, respectively. Lactate dehydrogenase (LDH) activity in media was determined by using an assay kit. The protein levels of caspase-12 were examined by Western blot analysis. The results showed that like TM (an ERS inducer), incubation with AGE-alb led to significant decrease in viability and increase in LDH activity in media and apoptotic rate in a dose-dependent manner. In addition, AGE-alb induced activation of caspase-12 especially at the concentration of 4 and 6 g/L (P < 0.01), which was similar to TM. However, PBA (an ERS inhibitor) protected RAW264.7 macrophages from AGE-alb-induced decrease in viability and increases in LDH activity and apoptosis. Moreover, PBA also inhibited the caspase-12 activation induced by AGE-alb (P < 0.05). These results suggest that AGE-alb may induce apoptosis in RAW 264.7 macrophages, and the mechanism may be related to the activation of ERS-associated apoptotic pathway mediated by caspase-12.
Animals
;
Apoptosis
;
Caspase 12
;
Cell Line, Tumor
;
Cell Survival
;
Endoplasmic Reticulum Stress
;
Macrophages
;
Mice
;
Phenylbutyrates
;
Serum Albumin
;
Tunicamycin

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