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Chen Z, Guo H, Lu Z, Sun K, Jin Q. Hyperglycemia aggravates spinal cord injury through endoplasmic reticulum stress mediated neuronal apoptosis, gliosis and activation. Biomed Pharmacother 2019; 112:108672. [PMID: 30784940 DOI: 10.1016/j.biopha.2019.108672] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 01/29/2019] [Accepted: 02/05/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Hyperglycemia has been shown to influence prognostic outcome of spinal cord injury (SCI). However, the corresponding mechanism is not very clear. AIM This study is expected to explore the role of endoplasmic reticulum (ER) stress in hyperglycemia aggravated SCI. METHODS Hyperglycemia was established in rats by intraperitoneal (i.p.) injection of streptozotocin. SCI was performed at the T10 of spinal cord through weight dropping. ER stress was suppressed by oral gavage of 4-PBA. ER stress, histological change of the injured spinal cords, neuronal apoptosis, demyelination, glial proliferation, inflammatory factor production, blood-spinal cord barrier (BSCB) permeability, TJ (Occludin, Claudin5) and AJ (β-catenin, P120) protein degradation, and locomotor recovery were determined using western blotting, immunohistochemistry, HE staining, Evan's Blue assay, BBB scores and inclined plane test, respectively. In vitro, rat spinal cord neurons cells (RSCNCs) and cerebral microvascular endothelial cells (RCMECs) were stimulated with high glucose (HG) and/or thapsigargin (TG). The effects of HG and/or TG on RSCNCs apoptosis, and AJ and TJ expression by RCMECs were evaluated with flow cytometry and western blotting, respectively. RESULTS Hyperglycemic rats exhibited enhanced ER stress, increased neuronal apoptosis, aggravated demyelination, increased glial proliferation and inflammatory factors secretion, more serious BSCB disruption and disturbed locomotor recovery. ER stress inhibition alleviated hyperglycemia induced adverse effect on neuronal apoptosis and BSCB permeability, whereas showed little influence on glial activation and inflammation. CONCLUSION ER stress was aggravated in hyperglycemic rats after SCI, and subsequently promoted neuronal apoptosis and BSCB disruption in rats.
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Affiliation(s)
- Zhirong Chen
- Department of Orthopedics, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Haohui Guo
- Department of Orthopedics, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Zhidong Lu
- Department of Orthopedics, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Kening Sun
- Department of Orthopedics, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China
| | - Qunhua Jin
- Department of Orthopedics, General Hospital of Ningxia Medical University, Yinchuan, 750004, Ningxia, China.
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Shi D, He T, Tang W, Li H, Wang C, Zheng M, Hu J, Song X, Ding Y, Chen YY, Shen Y, Jin H, Wang LL. Local application of MDL28170-loaded PCL film improves functional recovery by preserving survival of motor neurons after traumatic spinal cord injury. Neurosci Lett 2019; 694:161-167. [PMID: 30528875 DOI: 10.1016/j.neulet.2018.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Revised: 11/30/2018] [Accepted: 12/03/2018] [Indexed: 11/27/2022]
Abstract
Neuronal death and organization degeneration can happen inordinately after spinal cord injury (SCI), which lead to nerve dysfunction. We aimed to determine whether local application of a cell permeable calpain I inhibitor (MDL28170) can promote SCI recovery by increasing neuronal cell viability. MDL28170-loaded polycaprolactone (PCL) film was fabricated. Scanning electron microscopy showed the surface of PCL film was smooth with holes (diameter at μM level). The PCL film was non-toxic, biological compatibility, and had good neuron adhension and slow release characteristic. MDL28170 increased VSC4.1 motor neurons' viability under tunicamycin (an endoplasmic reticulum stress) induced injury. In a traumatic SCI rat model, MDL28170-loaded PCL film reduced the area of lesion cavity, and promoted recovery of locomotor behavior. Moreover, the expression of GAP-43 was upregulated after MDL28170-loaded PCL film treatment. Thus, our findings demonstrated that localized delivery of MDL28170 could promote SCI recovery by inhibiting endoplasmic reticulum stress, preserving survival of the motor neurons, which may point out a promising therapeutic target for treating SCI patient.
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Affiliation(s)
- Dongling Shi
- Academy of Chinese Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, 311400, China
| | - Teng He
- Department of Basic Medicine Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Weijian Tang
- Department of Basic Medicine Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Heyangzi Li
- Department of Basic Medicine Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Chao Wang
- Department of Basic Medicine Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Mingzhi Zheng
- Department of Pharmacology, Hangzhou Medical College, Hangzhou, 310053, China
| | - Jue Hu
- Department of Pharmacology, Hangzhou Medical College, Hangzhou, 310053, China
| | - Xinghui Song
- Core Facilities, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Yuemin Ding
- Department of Clinical Medicine, School of Medicine, Zhejiang University City College, Hangzhou, 310015, China
| | - Ying-Ying Chen
- Department of Basic Medicine Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Yueliang Shen
- Department of Basic Medicine Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Hongfeng Jin
- Department of Cardiology, Zhejiang Hospital, Hangzhou, 310030, China.
| | - Lin-Lin Wang
- Department of Basic Medicine Sciences, School of Medicine, Zhejiang University, Hangzhou, 310058, China.
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Li H, Zhang X, Qi X, Zhu X, Cheng L. Icariin Inhibits Endoplasmic Reticulum Stress-induced Neuronal Apoptosis after Spinal Cord Injury through Modulating the PI3K/AKT Signaling Pathway. Int J Biol Sci 2019; 15:277-286. [PMID: 30745820 PMCID: PMC6367543 DOI: 10.7150/ijbs.30348] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/28/2018] [Indexed: 12/13/2022] Open
Abstract
Endoplasmic reticulum (ER) stress-induced neuronal apoptosis is a crucial pathological process of spinal cord injury (SCI). In our previous study, icariin (ICA) showed neuroprotective effects in SCI. However, the relationships between ER stress and ICA in SCI are unclear yet. Therefore, whether ICA could ameliorate SCI via attenuating ER stress was investigated in vitro and in vivo. Adult mice were established SCI model and received vehicle solution or ICA by gavage once per day in vivo. The primary cultured cells were treated with or without thapsigargin (TG), ICA or LY294002 to induce ER stress in vitro. Motor dysfunction, neuronal apoptosis, tissue damage and inhibition of PI3K/AKT pathway were induced by ER stress after SCI. But ICA administration significantly enhanced motor recovery and protected spinal cord tissues against infraction and hemorrhage, etc. post injury. Meanwhile, the expression of ER stress markers ATF6, IRE1α, GRP78, XBP1 and eIF2α was decreased, while the level of p-AKT/AKT was increased by ICA. Furthermore, ICA significantly inhibited the expression of ER stress apoptotic proteins caspase-12, CHOP, Bax/Bcl-2, caspase-9 and caspase-3. Moreover, immunofluorescence double staining indicated that ICA reduced GRP78, CHOP and TUNEL positive neurons following SCI. However, this beneficial effect of ICA was abolished by PI3K/AKT inhibitor LY294002 in vitro. Finally, ICA preserved the ultra-structure of ER by transmission electron microscope histologically. This study suggested that the neuroprotective effect of ICA on motor recovery and neuronal survival was related to attenuating ER stress via PI3K/AKT signaling pathway after SCI.
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Affiliation(s)
- Haotian Li
- Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China.,Key Laboratory of spine and spinal cord injury repair and regeneration (Tongji University), Ministry of Education, Shanghai, China
| | - Xinran Zhang
- School & Hospital of Stomatology, Tongji University, Shanghai Engineering Research Center of Tooth Restoration and Regeneration, Shanghai 200072, China
| | - Xi Qi
- Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China.,Key Laboratory of spine and spinal cord injury repair and regeneration (Tongji University), Ministry of Education, Shanghai, China
| | - Xu Zhu
- Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China.,Key Laboratory of spine and spinal cord injury repair and regeneration (Tongji University), Ministry of Education, Shanghai, China
| | - Liming Cheng
- Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai 200065, China.,Key Laboratory of spine and spinal cord injury repair and regeneration (Tongji University), Ministry of Education, Shanghai, China
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Inhibition of Endoplasmic Reticulum Stress Preserves the Integrity of Blood-Spinal Cord Barrier in Diabetic Rats Subjected to Spinal Cord Injury. Sci Rep 2017; 7:7661. [PMID: 28794417 PMCID: PMC5550423 DOI: 10.1038/s41598-017-08052-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 07/04/2017] [Indexed: 12/23/2022] Open
Abstract
The blood-spinal cord barrier (BSCB) plays significance roles in recovery following spinal cord injury (SCI), and diabetes mellitus (DM) impairs endothelial cell function and integrity of BSCS. Endoplasmic reticulum (ER) stress occurs in the early stages of SCI and affects prognosis and cell survival. However, the relationship between ER stress and the integrity of BSCB in diabetic rats after SCI remains unclear. Here we observed that diabetic rats showed increased extravasation of Evans Blue (EB) dye, and loss of endothelial cells and pericytes 1 day after SCI compared to non-diabetic rats. Diabetes was also shown to induce activation of ER stress. Similar effects were observed in human brain microvascular endothelial cells. 4-phenylbutyric acid (4-PBA), an ER stress inhibitor lowered the adverse effect of diabetes on SCI, reduced EB dye extravasation, and limited the loss of endothelial cells and pericytes. Moreover, 4-PBA treatment partially reversed the degradation of tight junction and adherens junction both in vivo and in vitro. In conclusion, diabetes exacerbates the disruption of BSCB after SCI via inducing ER stress, and inhibition of ER stress by 4-PBA may play a beneficial role on the integrity of BSCB in diabetic SCI rats, leading to improved prognosis.
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Ge G, Yan Y, Cai H. Ginsenoside Rh2 Inhibited Proliferation by Inducing ROS Mediated ER Stress Dependent Apoptosis in Lung Cancer Cells. Biol Pharm Bull 2017; 40:2117-2124. [DOI: 10.1248/bpb.b17-00463] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Guanqun Ge
- Department of Breast Surgery, The First Affiliated Hospital of Xi’an Jiaotong University
| | - Yan Yan
- The Second Department of Thoracic Surgery, The First Affiliated Hospital of Xi’an Jiaotong University
| | - Hui Cai
- Department of Vascular Surgery, The First Affiliated Hospital of Xi’an Jiaotong University
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Hyperbaric Oxygen Treatment Protects Against Spinal Cord Injury by Inhibiting Endoplasmic Reticulum Stress in Rats. Spine (Phila Pa 1976) 2015; 40:E1276-83. [PMID: 26192724 DOI: 10.1097/brs.0000000000001056] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Experimental animal study of treatment of SCI. OBJECTIVE To explore whether HBO treatment protects against secondary SCI by inhibiting the ER stress response. SUMMARY OF BACKGROUND DATA SCI is a neurological disorder that can severely limit the execution of the simplest day-to-day functions. ER stress plays an important role in the induction of neuronal apoptosis after SCI. HBO treatment can alleviate secondary injury and benefit neurological recovery after SCI, but the effect of HBO on ER stress response after SCI is yet to be characterized. METHODS The spinal cord of rats was injured via T10 laminectomy. Experimental animals were randomly assigned to 1 of 3 groups: sham-operated, SCI, and SCI+HBO. Each group was analyzed 1, 2, 3, 7, and 14 days after injury. Neurological recovery was evaluated using the Basso-Beattie-Bresnahan (BBB) scoring system and the TdT-mediated dUTP nick-end labeling reaction was carried out to visualize apoptotic cells. The expression of ER stress-related factors was evaluated by immunohistochemical, western blot, and real-time reverse transcription-polymerase chain reaction analyses. RESULTS SCI-induced apoptosis and an increase in the levels of CCAAT-enhancer-binding protein homologous protein (CHOP), and caspase-12 and caspase-3 compared with the sham-operated group. HBO treatment decreased CHOP and caspase-12 and caspase-3 expression as well as apoptosis compared with the SCI group. In addition, BBB scores were improved in the SCI+HBO relative to the SCI group at 7 and 14 days. CONCLUSION These results suggest that HBO treatment alleviates secondary injury to the spinal cord by inhibiting ER stress induced apoptosis, thereby promoting the recovery of neurological function. LEVEL OF EVIDENCE N/A.
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Zhou KL, Zhou YF, Wu K, Tian NF, Wu YS, Wang YL, Chen DH, Zhou B, Wang XY, Xu HZ, Zhang XL. Stimulation of autophagy promotes functional recovery in diabetic rats with spinal cord injury. Sci Rep 2015; 5:17130. [PMID: 26597839 PMCID: PMC4657088 DOI: 10.1038/srep17130] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 10/26/2015] [Indexed: 11/09/2022] Open
Abstract
In this study we examined the relationship between autophagy and apoptosis in diabetic rats after spinal cord injury (SCI), also we determined the role of autophagy in diabetes-aggravated neurological injury in vivo and in vitro. Our results showed that diabetes decreased the survival of neurons, promoted astrocytes proliferation, increased inflammatory cells infiltration and inhibited functional recovery after SCI. Diabetes was shown to confer increased activation of apoptotic pathways, along with an increase in autophagy; similar effects were also observed in vitro in neuronal PC12 cells. Treatment with rapamycin, an autophagy activator, partially abolished the adverse effect of diabetes, suggesting that diabetes may enhance neurological damage and suppress locomotor recovery after SCI, in addition to its effects on apoptosis and autophagy. In contrast, further stimulation of autophagy improved neurological function via inhibition of apoptosis. These results explained how diabetes exacerbates SCI in cellular level and suggested autophagy stimulation to be a new therapeutic strategy for diabetic SCI.
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Affiliation(s)
- Kai-liang Zhou
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Yi-fei Zhou
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Kai Wu
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Nai-feng Tian
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Yao-sen Wu
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Yong-li Wang
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - De-heng Chen
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Bin Zhou
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Xiang-yang Wang
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Hua-zi Xu
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
| | - Xiao-lei Zhang
- Department of Orthopaedics, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China.,Zhejiang Provincial Key Laboratory of Orthopaedics, Wenzhou, Zhejiang Province, China
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Hong Z, Hong H, Chen H, Wang Z, Hong D. Protective effects of erythropoietin in experimental spinal cord injury by reducing the C/EBP-homologous protein expression. Neurol Res 2013; 34:85-90. [PMID: 22196867 DOI: 10.1179/1743132811y.0000000026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Affiliation(s)
- Zhenghua Hong
- Department of OrthopedicsTaizhou Hospital of Zhejiang Province, China
| | - Huaxing Hong
- Department of OrthopedicsTaizhou Hospital of Zhejiang Province, China
| | - Haixiao Chen
- Department of OrthopedicsTaizhou Hospital of Zhejiang Province, China
| | - Zhangfu Wang
- Department of OrthopedicsTaizhou Hospital of Zhejiang Province, China
| | - Dun Hong
- Department of OrthopedicsTaizhou Hospital of Zhejiang Province, China
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Liu W, Ding Y, Zhang X, Wang L. Bone marrow stromal cells inhibit caspase-12 expression in rats with spinal cord injury. Exp Ther Med 2013; 6:671-674. [PMID: 24137244 PMCID: PMC3786846 DOI: 10.3892/etm.2013.1201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 06/25/2013] [Indexed: 02/06/2023] Open
Abstract
The mechanisms underlying the potentially beneficial effect of bone marrow stem cells (BMSCs) on spinal cord injury (SCI) are unknown. Therefore, the aim of the present study was to explore the protective effect of BMSCs in rats with SCI. A total of 45 adult male Sprague-Dawley rats were randomly divided into three groups; the SCI group (n=15), the BMSC group (n=15) and the sham-operation group (n=15). In the SCI and BMSC treatment groups, a modified Allen’s weight-drop technique was used to induce SCI. The BMSC treatment group received an injection of BMSCs using a microneedle into the epicenter of the spinal cord 24 h after injury. Rats in the sham-operation group were not subjected to SCI; however, the corresponding vertebral laminae were removed. Seven days after transplantation, a rapid recovery was observed in the Basso, Beattie and Bresnahan (BBB) scores of the BMSC treatment group, whereas the BBB scores in the SCI group remained low (P<0.05). Caspase-12 expression in the SCI group was increased compared with that in the sham-operation group, whereas caspase-12 expression was attenuated 24 h after transplantation in the BMSC treatment group (P<0.05). In conclusion, the transplantation of BMSCs may improve locomotor function and attenuate caspase-12 expression following SCI. Therefore, it is likely to be an effective strategy for preventing severe injury of the spinal cord.
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Affiliation(s)
- Wei Liu
- Department of Prosthodontics, Stomatology Hospital, College of Medical Sciences, Zhejiang University, Hangzhou, Zhejiang 310006, P.R. China
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Refined Qingkailing Protects MCAO Mice from Endoplasmic Reticulum Stress-Induced Apoptosis with a Broad Time Window. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:567872. [PMID: 22536287 PMCID: PMC3320064 DOI: 10.1155/2012/567872] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Revised: 01/02/2012] [Accepted: 01/03/2012] [Indexed: 11/18/2022]
Abstract
In the current study, we are investigating effect of refined QKL on ischemia-reperfusion-induced brain injury in mice. Methods. Mice were employed to induce ischemia-reperfusion injury of brain by middle cerebral artery occlusion (MCAO). RQKL solution was administered with different doses (0, 1.5, 3, and 6 mL/kg body weight) at the same time of onset of ischemia, and with the dose of 1.5 mL/kg at different time points (0, 1.5, 3, 6, and 9 h after MCAO). Neurological function and brain infarction were examined and cell apoptosis and ROS at prefrontal cortex were evaluated 24 h after MCAO, and western blot and intracellular calcium were also researched, respectively. Results. RQKL of all doses can improve neurological function and decrease brain infarction, and it performed significant effect in 0, 1.5, 3, and 6 h groups. Moreover, RQKL was able to reduce apoptotic process by reduction of caspase-3 expression, or restraint of eIF2a phosphorylation and caspase-12 activation. It was also able to reduce ROS and modulate intracellular calcium in the brain. Conclusion. RQKL can prevent ischemic-induced brain injury with a time window of 6 h, and its mechanism might be related to suppress ER stress-mediated apoptotic signaling.
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Yan Z, Hoffmann A, Kaiser EK, Grunwald WC, Cool DR. Misfolding of Mutated Vasopressin Causes ER-Retention and Activation of ER-Stress Markers in Neuro-2a Cells. ACTA ACUST UNITED AC 2011; 4:136-146. [PMID: 24567768 PMCID: PMC3932059 DOI: 10.2174/1876528901104010136] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Arginine-vasopressin (AVP) is a peptide hormone normally secreted from neuroendocrine cells via the regulated secretory pathway. In Familial Neurohypophyseal Diabetes Insipidus (FNDI), an autosomal dominant form of central diabetes insipidus, mutations of pro-vasopressin appear to accumulate in the endoplasmic reticulum (ER) causing a lack of biologically active AVP in the blood. To investigate the effect of pro-vasopressin mutations regarding intracellular functions of protein targeting and secretion, we created two FNDI-associated amino acid substitution mutants, e.g., G14R, and G17V in frame with green fluorescent protein (GFP) and pro-vasopressin (VP) in frame with red fluorescent protein (VP-RFP). Fluorescence microscopy of Neuro-2a cells expressing these constructs revealed co-localization of VP-GFP and VP-RFP to punctate granules along the length and accumulating at the tips of neurites, characteristic of regulated secretory granules. In contrast, the two FNDI-associated amino acid substitution mutants, e.g., G14R-GFP, and G17VGFP, were localized to a perinuclear region of the Neuro-2a cells characteristic of the endoplasmic reticulum. Co-expression of these mutants with VP-RFP showed VP-RFP was retained in the ER, co-localized with the mutants suggesting the formation of heterodimers as found in FNDI. Stimulated secretion experiments indicated that VP-GFP was secreted in an inducible manner whereas, G14R-GFP and G17V-GFP were retained to nearly 100% within the cells. Analysis by western blotting and semi-quantitative RT-PCR indicated an increased protein and mRNA expression for an ER resident molecular chaperone, BiP. Further analysis of ER-storage disease-associated proteins such as caspase 12 and CHOP showed an increase in these as well. The results suggest that G14R-GFP and G17V-GFP are retained in the ER of Neuro-2a cells, resulting in up-regulation of the molecular chaperone BiP, and activation of the ER-storage disease-associated caspase cascade system.
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Affiliation(s)
- Zhongyu Yan
- Department of Pharmacology & Toxicology, Wright State University, Dayton, OH 45435
| | - Andrea Hoffmann
- Department of Pharmacology & Toxicology, Wright State University, Dayton, OH 45435
| | - Erin Kelly Kaiser
- Department of Pharmacology & Toxicology, Wright State University, Dayton, OH 45435
| | - William C Grunwald
- Department of Pharmacology & Toxicology, Wright State University, Dayton, OH 45435
| | - David R Cool
- Department of Pharmacology & Toxicology, Wright State University, Dayton, OH 45435
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The galactosylation of N(ω)-nitro-L-arginine enhances its anti-nocifensive or anti-allodynic effects by targeting glia in healthy and neuropathic mice. Eur J Pharmacol 2011; 656:52-62. [PMID: 21296071 DOI: 10.1016/j.ejphar.2011.01.045] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 01/24/2011] [Accepted: 01/25/2011] [Indexed: 11/23/2022]
Abstract
This study has investigated whether the galactosyl ester prodrug of N(ω)-nitro-L-arginine (NAGAL), shows enhanced analgesic efficacy in healthy mice and in models of visceral and neuropathic pain: the writhing test and the spared nerve injury (SNI), respectively. NAGAL was compared to methyl ester pro-drug of N(ω)-nitro-l-arginine (L-NAME), a widely exploited non-specific nitric oxide synthase (NOS) inhibitor, for analgesic potential. The writhing test revealed that the ED(50) value, along with the 95% confidence limit (CL) was 3.82 (1.77-6.04) mg/kg for NAGAL and, 36.75 (20.07-68.37) mg/kg for L-NAME. Notably, NAGAL elicited a greater anti-allodynic effect than L-NAME did in neuropathic mice. Biomolecular and morphological studies revealed that spared nerve injury increased the expressions of pro-inflammatory enzymes (caspase-1) and two glial cell biomarkers: integrin alpha M (ITGAM) and glial fibrillary acidic protein (GFAP) in the spinal cord. Finally, GLUT-3, an isoform of the hexose transporters capable to bind NAGAL and inducible NOS (iNOS), were found to be over-expressed in the activated astrocytes of the spinal cord of neuropathic mice. NAGAL administration normalized expression levels of these biomarkers. NAGAL showed a greater efficacy in inhibiting visceral pain and allodynia than L-NAME possibly by a greater cell permeation through the hexose transporter which is highly over-expressed by activated glia.
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Matus S, Glimcher LH, Hetz C. Protein folding stress in neurodegenerative diseases: a glimpse into the ER. Curr Opin Cell Biol 2011; 23:239-52. [PMID: 21288706 DOI: 10.1016/j.ceb.2011.01.003] [Citation(s) in RCA: 177] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 01/05/2011] [Accepted: 01/11/2011] [Indexed: 01/19/2023]
Abstract
Several neurodegenerative diseases share common neuropathology, primarily featuring the presence in the brain of abnormal protein inclusions containing specific misfolded proteins. Recent evidence indicates that alteration in organelle function is a common pathological feature of protein misfolding disorders, highlighting perturbations in the homeostasis of the endoplasmic reticulum (ER). Signs of ER stress have been detected in most experimental models of neurological disorders and more recently in brain samples from human patients with neurodegenerative disease. To cope with ER stress, cells activate an integrated signaling response termed the unfolded protein response (UPR), which aims to reestablish homeostasis in part through regulation of genes involved in protein folding, quality control and degradation pathways. Here we discuss the particular mechanisms currently proposed to be involved in the generation of protein folding stress in different neurodegenerative conditions and speculate about possible therapeutic interventions.
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Affiliation(s)
- Soledad Matus
- Center for Molecular Studies of Cell, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
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