scholarly journals GanDouLing combined with Penicillamine improves cerebrovascular injury via PERK/eIF2α/CHOP endoplasmic reticulum stress pathway in the mouse model of Wilson’s disease

2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Yonghua Chen ◽  
Bo Zhang ◽  
Shijian Cao ◽  
Wei Huang ◽  
Ni Liu ◽  
...  

We aim to investigate the function and mechanism of GanDouLing combinated with Penicillamine on cerebrovascular injury in Wilson’s disease (WD). ELISA was performed to analyze the expression of vascular injury factors. Pathological changes of cerebral vessels were observed by HE stain. Immunohistochemistry assays were performed to analyze the expression of ICAM-1, VCAM-1, and GRP78. Western blotting was measured to analyze the expression of caspase-3, caspase-12, PERK, eIF2α, and CHOP. Apoptosis was detected with TUNEL assay. The expression of vascular injury factors and ICAM-1, VCAM-1 was significantly increased by WD and markedly decreased in GanDouLing-Penicillamine group. The expression of caspase-3, caspase-12, PERK, eIF2α, and CHOP were obviously expressed in Wilson group, GanDouLing-Penicillamine suppressed apoptosis and endoplasmic reticulum (ER) stress. Our findings suggested that GanDouLing-Penicillamine improved cerebrovascular injury through PERK/eIF2α/CHOP ER stress pathway in the mouse model of WD.

2021 ◽  
Vol 15 ◽  
Author(s):  
Fengwu Li ◽  
Xiaokun Geng ◽  
Hangil Lee ◽  
Melissa Wills ◽  
Yuchuan Ding

While it is well-known that pre-stroke exercise conditioning reduces the incidence of stroke and the development of comorbidities, it is unclear whether post-stroke exercise conditioning is also neuroprotective. The present study investigated whether exercise postconditioning (PostE) induced neuroprotection and elucidated the involvement of SIRT1 regulation on the ROS/ER stress pathway. Adult rats were subjected to middle cerebral artery occlusion (MCAO) followed by either: (1) resting; (2) mild exercise postconditioning (MPostE); or (3) intense exercise postconditioning (IPostE). PostE was initiated 24 h after reperfusion and performed on a treadmill. At 1 and 3 days thereafter, we determined infarct volumes, neurological defects, brain edema, apoptotic cell death through measuring pro- (BAX and Caspase-3) and anti-apoptotic (Bcl-2) proteins, and ER stress through the measurement of glucose-regulated protein 78 (GRP78), inositol-requiring 1α (IRE1α), protein kinase RNA-like endoplasmic reticulum kinase (PERK), activating transcription factor 6 (ATF6), C/EBP homologous protein (CHOP), Caspase-12, and SIRT1. Proteins were measured by Western blot. ROS production was detected by flow cytometry.Compared to resting rats, both MPostE and IPostE significantly decreased brain infarct volumes and edema, neurological deficits, ROS production, and apoptotic cell death. MPostE further increased Bcl-2 expression and Bcl-2/BAX ratio as well as BAX and Caspase-3 expressions and ROS production (*p < 0.05). Both PostE groups saw decreases in ER stress proteins, while MPostE demonstrated a further reduction in GRP78 (***p < 0.001) and Caspase-12 (*p < 0.05) expressions at 1 day and IRE1α (**p < 0.01) and CHOP (*p < 0.05) expressions at 3 days. Additionally, both PostE groups saw significant increases in SIRT1 expression.In this study, both mild and intense PostE levels induced neuroprotection after stroke through SIRT1 and ROS/ER stress pathway. Additionally, the results may provide a base for our future study regarding the regulation of SIRT1 on the ROS/ER stress pathway in the biochemical processes underlying post-stroke neuroprotection. The results suggest that mild exercise postconditioning might play a similar neuroprotective role as intensive exercise and could be an effective exercise strategy as well.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Zarith Nameyrra Md Nesran ◽  
Nurul Husna Shafie ◽  
Amirah Haziyah Ishak ◽  
Norhaizan Mohd Esa ◽  
Amin Ismail ◽  
...  

Epigallocatechin-3-gallate (EGCG) is the most abundant bioactive polyphenolic compound among the green tea constituents and has been identified as a potential anticancer agent in colorectal cancer (CRC) studies. This study was aimed to determine the mechanism of actions of EGCG when targeting the endoplasmic reticulum (ER) stress pathway in CRC. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay was performed on HT-29 cell line and normal cell line (3T3) to determine the EGCG toxicity. Next, western blot was done to observe the expression of the related proteins for the ER stress pathway. The Caspase 3/7 assay was performed to determine the apoptosis induced by EGCG. The results demonstrated that EGCG treatment was toxic to the HT-29 cell line. EGCG induced ER stress in HT-29 by upregulating immunoglobulin-binding (BiP), PKR-like endoplasmic reticulum kinase (PERK), phosphorylation of eukaryotic initiation factor 2 alpha subunit (eIF2α), activating transcription 4 (ATF4), and inositol-requiring kinase 1 alpha (IRE1α). Apoptosis was induced in HT-29 cells after the EGCG treatment, as shown by the Caspase 3/7 activity. This study indicates that green tea EGCG has the potential to inhibit colorectal cancer cells through the induction of ER stress.


2005 ◽  
Vol 25 (3) ◽  
pp. 358-370 ◽  
Author(s):  
Koji Aoyama ◽  
David M Burns ◽  
Sang Won Suh ◽  
Philippe Garnier ◽  
Yasuhiko Matsumori ◽  
...  

Endoplasmic reticulum (ER) stress leads to activation of caspase-12, which in turn can lead to activation of caspase-3 and cell death. Here we report that transient acidosis induces ER stress and caspase-12-mediated cell death in mouse astrocytes. After a 3-hour incubation at pH 6.0, astrocytes exhibited delayed cell death associated with nuclear condensation and fragmentation. Cell death was reduced by the protein synthesis inhibitor cycloheximide, further suggesting an active cell death program. Acidosis increased the expression of the ER chaperone protein GRP-78, indicative of ER stress. Acidosis also increased caspase-12 mRNA expression, caspase-12 protein expression, cleavage of caspase-12 to its active form, and activation of caspase-3. Each of these effects was suppressed in astrocytes pretreated with caspase-12 antisense phosphorodiamidate morpholino oligodeoxynucleotides (PMOs). Caspase-12 antisense PMOs also reduced the cell death induced by acidosis. Immunoprecipitation studies showed dissociation of both caspase-12 and Ire1-α from GRP-78, thereby suggesting a mechanism by which acidosis can initiate the ER stress response. To evaluate caspase-12 activation in vivo, rats were subjected to middle cerebral artery ischemia–reperfusion. Immunostaining of brain sections harvested 24 hours later showed increased caspase-12 expression and nuclear condensation in astrocytes of the periinfarct region exposed to acidosis during ischemia. These findings suggest that acidosis induces ER stress and caspase-12 activation, and that these changes may contribute to delayed cell death after ischemia.


2019 ◽  
Vol 174 (1) ◽  
pp. 147-158 ◽  
Author(s):  
Muhammad M Hossain ◽  
Jason R Richardson

Abstract Neurotrophins are a family of growth factors crucial for growth and survival of neurons in the developing and adult brain. Reduction in neurotrophin levels is associated with reduced neurogenesis and cognitive deficits in rodents. Recently, we demonstrated that long-term exposure to low levels of the pyrethroid pesticide deltamethrin causes hippocampal endoplasmic reticulum (ER) stress and learning deficits in mice. Here, we found that nerve growth factor (NGF) mRNA and protein were selectively reduced in the hippocampus of deltamethrin-treated mice. To explore potential mechanisms responsible for this observation, we employed mouse primary hippocampal neurons. Exposure of neurons to deltamethrin (1–5 μM) caused ER stress as indicated by increased levels of C/EBP-homologous protein (CHOP) and glucose-regulated protein 78 (GRP78). These changes were accompanied by increased levels of caspase-12, activated caspase-3, and decreased levels of NGF. Inhibition of ER stress with the eukaryotic initiation factor 2 alpha (eIF2α) inhibitor salubrinal abolished deltamethrin-induced activation of caspase-12 and caspase-3, and restored NGF levels. Furthermore, deltamethrin decreased Akt (protein kinase B) phosphorylation, which was significantly prevented by co-treatment with NGF or SC-79 in cells. Collectively, these results demonstrate that the loss of NGF following ER stress may contribute to deltamethrin-induced apoptosis in the hippocampus through the Akt signaling pathway, and that this may provide a plausible mechanism for impaired learning and memory observed following exposure of mice to deltamethrin.


Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Daisuke Kudo ◽  
Hajime Furukawa ◽  
Satoru Eguchi ◽  
Tomoki Hashimoto

Background: Aneurysmal subarachnoid hemorrhage (SAH) can cause significant mortality and morbidity. To develop a therapy for prevention of intracranial aneurysmal rupture and subsequent SAH, it is important to clarify the mechanism of intracranial aneurysmal rupture. Stimulation of the renin-angiotensin system (RAS) causes hypertension and cardiovascular remodeling. Recent evidence shows that angiotensin II enhances endoplasmic reticulum (ER) stress and inhibition of ER stress prevents angiotensin II-induced vascular remodeling but not hypertension in mice. RAS has also been implicated in intracranial aneurysms. We have previously shown that angiotensin II receptor blocker (losartan) prevented intracranial aneurysmal rupture in a mouse model without affecting systemic hypertension. To clarify the mechanism of intracranial aneurysmal rupture via RAS, we have tested our hypothesis that inhibition of ER stress prevents intracranial aneurysmal rupture in a mouse model. Method: We used a mouse model of intracranial aneurysms in which spontaneous aneurysmal rupture causes neurologic symptoms. Intracranial aneurysms were induced in wild type mice by a single stereotactic injection of elastase (35mU) into the cerebrospinal fluid at right basal cistern and deoxycorticosterone (DOCA)-salt hypertension. Vehicle or 4-phenylbutyric acid (PBA, ER stress inhibitor , 100mg/kg/day) was subcutaneously injected into all mice once a day. To detect aneurysmal rupture, we performed daily neurological examinations. Symptomatic mice were euthanized immediately when they developed neurological symptoms, and all asymptomatic mice were euthanized 21 days after aneurysm induction. The incidence of aneurysms and rupture rate were compared between vehicle group and PBA group. Results: The incidence of aneurysms was not significantly different between two groups (100% in vehicle, 20 of 20 vs. 87% in PBA, 20 of 23, p=0.09). However, rupture rate was significantly lower in the PBA group (60%, 12 of 20) than the vehicle group (95%, 19 of 20). (p=0.008). Conclusion: Inhibition of ER stress reduced aneurysmal rupture in a mouse model of intracranial aneurysm induced by combination of elastase injection and DOCA-salt hypertension.


2011 ◽  
Vol 406 (1) ◽  
pp. 44-58 ◽  
Author(s):  
Jason L. Burkhead ◽  
Martina Ralle ◽  
Phillip Wilmarth ◽  
Larry David ◽  
Svetlana Lutsenko

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Woong Park ◽  
Hyeongwan Kim ◽  
Yujin Jung ◽  
Kyung Pyo Kang ◽  
Won Kim

Abstract Background and Aims Nephrotoxicity is an important cisplatin-induced adverse reaction and restricts the use of cisplatin to treat malignant tumors. Endoplasmic reticulum (ER) stress is caused by the accumulation of misfolded proteins, and is induced by cisplatin in kidneys. SIRT2 nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase is a member of the sirtuin family, but its role in cisplatin-induced ER stress remains unclear. Method To investigate the effect of SIRT2 on cisplatin-induced ER stress using SIRT2 knockout mice and human proximal tubular epithelial cells (HK-2 cells). We treated cisplatin (20 µg/mL) or induced by intraperitoneal injection of cisplatin (20 mg/kg) and evaluated the changes of ER stress and its signal mechanism. Results Cisplatin administration was found to significantly increase the expressions of PRKR-like ER kinase (PERK), phosphorylation of eukaryotic translation initiation factor 2α (eIF2α), and the C/EBP homologous protein (CHOP) and caspase-12 in the kidneys of SIRT2-wild type mice. However, cisplatin-induced increases in the expressions of p-PERK, p-eIF2α, CHOP and, caspase-12 were diminished in kidneys of SIRT2 knockout mice. In vitro, cisplatin significantly increased the expressions of p-PERK, p-eIF2α, CHOP, and caspase-12 in HK-2 cells. When the effect of SIRT2 on cisplatin-induced ER stress was evaluated using SIRT2-siRNA (ON-TARGET plus human SIRT2 siRNA) or the SIRT2 inhibitors, AGK2 and AK1, knockdown or inhibition of SIRT2 significantly attenuated the cisplatin-induced protein expression of p-PERK, p-eIF2α, CHOP, and caspase-12. Immunoprecipitation studies showed SIRT2 bound physically to heat shock factor (HSF)1 and that HSF1 acetylation was significantly increased by cisplatin. In addition, knockdown of SIRT2 increased cisplatin-induced HSF1 acetylation and increased the expression of heat shock protein (HSP)70. Conclusion These observations suggest that suppression of SIRT2 ameliorates cisplatin-induced ER stress by increasing HSF1 acetylation and HSP expression.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jingyang Feng ◽  
Yuhong Chen ◽  
Bing Lu ◽  
Xiangjun Sun ◽  
Hong Zhu ◽  
...  

Abstract Background Retinal pigment epithelium cells (RPEs) are critical for maintaining retinal homeostasis. Accumulation of age-related lipofuscin, N-retinylidene-N-retinylethanolamine (A2E), makes RPEs vulnerable to blue light-mediated damage, which represents an initial cause of some retinal degenerative diseases. This study investigated the activation of autophagy and the signaling pathway involved in glucose-related protein 78 (GRP78) induced autophagy in blue light-mediated damage of A2E-laden RPEs. In addition, we explored whether autophagy could play a protective role by alleviating endoplasmic reticulum (ER) stress to promote RPEs survival. Methods RPEs were incubated with 25 μM A2E for 2 h and exposed to blue light for 20 min. The expression of ER stress-related apoptotic proteins, CHOP and caspase-12, as well as autophagy marker LC3 were measured by western blot analysis. Autophagosomes were observed by both transmission electron microscopy and immunofluorescence assays. GRP78 interference performed by short hairpin RNA (shRNA) was used to identify the signaling pathway involved in GRP78 induced autophagy. Cell death was assessed using TUNEL analysis. Results Treatment with A2E and blue light markedly increased the expression of ER stress-related apoptotic molecules CHOP and caspase-12. The activation of autophagy was recognized by observing autophagosomes at ultrastructural level. Additionally, punctate distributions of LC3 immunofluorescence and enhanced conversions of LC3-I to LC3-II were found in A2E and blue light-treated RPEs. Moreover, GRP78 interference reduced AMPK phosphorylation and promoted mTOR activity, thereby downregulating autophagy. In addition, the inhibition of autophagy made RPEs vulnerable to A2E and blue light damage. In contrast, the autophagy inducer rapamycin alleviated ER stress to promote RPEs survival. Conclusions GRP78 activates autophagy via AMPK/mTOR in blue light-mediated damage of A2E-laden RPEs in vitro. Autophagy may be a vital endogenous cytoprotective process to alleviate stress for RPEs survival in retinal degenerative diseases.


2020 ◽  
Vol 2020 ◽  
pp. 1-7 ◽  
Author(s):  
Shen Yan ◽  
Liu Yingchao ◽  
Wang Zhangliu ◽  
Ruan Xianli ◽  
Li Si ◽  
...  

The purpose of this study was to verify the effect of berberine (BBR) on endoplasmic reticulum stress (ERS) and apoptosis of intestinal epithelial cells (IECs) in mice with ulcerative colitis (UC). BALB/c mice were randomly divided into five groups as follows: blank control, model, and low-, medium-, and high-dose BBR. A dextran sodium sulfate- (DSS-) induced model of UC was prepared, and the low-, medium-, and high-dose BBR groups were simultaneously gavaged with a BBR suspension for 7 d. Disease activity index (DAI) was assessed, and tissue damage index (TDI) was assessed from colon samples after the last administration. TUNEL assays were used to detect apoptosis of IECs. Immunohistochemistry and/or real-time PCR were applied to determine the expression of GRP78, caspase-12, and caspase-3. In all BBR treatment groups, clinical symptoms of colitis and histopathological damage were significantly reduced. The high-dose BBR group exhibited particularly pronounced decrease (p<0.01) in both DAI (0.48 ± 0.36) and TDI (1.62 ± 0.64) relative to the model group (1.50 ± 0.65 and 3.88 ± 0.04, respectively). In colon tissues of the model group, the number of apoptotic IECs was significantly increased; the expression of GRP78, caspase-12, and caspase-3 proteins was significantly increased; and the expression of the GRP78 mRNA was upregulated. In low-, medium-, and high-dose BBR groups, the number of apoptotic IECs was significantly reduced. Moreover, GRP78 and caspase-3 expression levels were significantly decreased in the medium- and high-dose BBR groups, caspase-12 expression was significantly decreased in the high-dose BBR group, and the GRP78 mRNA expression level was significantly decreased in the high-dose BBR group. BBR can effectively reduce the rate of IEC apoptosis in UC mice and alleviate the inflammatory response in the colon. The underlying mechanism seems to involve ERS modulation and inhibition of ERS-mediated activation of the caspase-12/caspase-3 apoptosis signaling pathway.


2019 ◽  
Vol 14 (7) ◽  
pp. 948-961 ◽  
Author(s):  
William D Rees ◽  
Martin Stahl ◽  
Kevan Jacobson ◽  
Brian Bressler ◽  
Laura M Sly ◽  
...  

Abstract Background and Aims Endoplasmic reticulum [ER] stress in intestinal epithelial cells [IECs] contributes to the pathogenesis of inflammatory bowel disease [IBD]. We hypothesized that ER stress changes innate signalling in human IECs, augmenting toll-like receptor [TLR] responses and inducing pro-inflammatory changes in underlying dendritic cells [DCs]. Methods Caco-2 cells and primary human colon-derived enteroid monolayers were exposed to ATP [control stressor] or thapsigargin [Tg] [ER stress inducer], and were stimulated with the TLR5 agonist flagellin. Cytokine release was measured by an enzyme immunoassay. ER stress markers CHOP, GRP78 and XBP1s/u were measured via quantitative PCR and Western blot. Monocyte-derived DCs [moDCs] were cultured with the IEC supernatants and their activation state was measured. Responses from enteroids derived from IBD patients and healthy control participants were compared. Results ER stress enhanced flagellin-induced IL-8 release from Caco-2 cells and enteroids. Moreover, conditioned media activated DCs to become pro-inflammatory, with increased expression of CD80, CD86, MHCII, IL-6, IL-15 and IL-12p70 and decreased expression of CD103 and IL-10. Flagellin-induced IL-8 production correlated with DC activation, suggesting a common stress pathway. Moreover, there were distinct differences in cytokine expression and basal ER stress between IBD and healthy subject-derived enteroid monolayers, suggesting a dysregulated ER stress pathway in IBD-derived enteroids. Conclusions Cellular stress enhances TLR5 responses in IECs, leading to increased DC activation, indicating a previously unknown mechanistic link between epithelial ER stress and immune activation in IBD. Furthermore, dysregulated ER stress may be propagated from the intestinal epithelial stem cell niche in IBD patients.


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