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Hsueh YY, Chang YJ, Huang CW, Handayani F, Chiang YL, Fan SC, Ho CJ, Kuo YM, Yang SH, Chen YL, Lin SC, Huang CC, Wu CC. Synergy of endothelial and neural progenitor cells from adipose-derived stem cells to preserve neurovascular structures in rat hypoxic-ischemic brain injury. Sci Rep 2015; 5:14985. [PMID: 26447335 PMCID: PMC4597209 DOI: 10.1038/srep14985] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 09/15/2015] [Indexed: 01/28/2023] Open
Abstract
Perinatal cerebral hypoxic-ischemic (HI) injury damages the architecture of neurovascular units (NVUs) and results in neurological disorders. Here, we differentiated adipose-derived stem cells (ASCs) toward the progenitor of endothelial progenitor cells (EPCs) and neural precursor cells (NPCs) via microenvironmental induction and investigated the protective effect by transplanting ASCs, EPCs, NPCs, or a combination of EPCs and NPCs (E+N) into neonatal HI injured rat pups. The E+N combination produced significant reduction in brain damage and cell apoptosis and the most comprehensive restoration in NVUs regarding neuron number, normal astrocytes, and vessel density. Improvements in cognitive and motor functions were also achieved in injured rats with E+N therapy. Synergistic interactions to facilitate transmigration under in vitro hypoxic microenvironment were discovered with involvement of the neuropilin-1 (NRP1) signal in EPCs and the C-X-C chemokine receptor 4 (CXCR4) and fibroblast growth factor receptor 1 (FGFR1) signals in NPCs. Therefore, ASCs exhibit great potential for cell sources in endothelial and neural lineages to prevent brain from HI damage.
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Affiliation(s)
- Yuan-Yu Hsueh
- Division of Plastic Surgery, National Cheng Kung University Hospital, North District, Tainan City, Taiwan
- Institute of Clinical Medicine, National Cheng Kung University, North District, Tainan City, Taiwan
| | - Ya-Ju Chang
- Department of Cell Biology and Anatomy, National Cheng Kung University, North District, Tainan City, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University, North District, Tainan City, Taiwan
| | - Chia-Wei Huang
- Institute of Basic Medical Sciences, National Cheng Kung University, North District, Tainan City, Taiwan
| | - Fitri Handayani
- Department of Cell Biology and Anatomy, National Cheng Kung University, North District, Tainan City, Taiwan
| | - Yi-Lun Chiang
- Department of Cell Biology and Anatomy, National Cheng Kung University, North District, Tainan City, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University, North District, Tainan City, Taiwan
| | - Shih-Chen Fan
- Department of Occupational Therapy, I-Shou University, Kaohsiung City, Taiwan
| | - Chien-Jung Ho
- Institute of Clinical Medicine, National Cheng Kung University, North District, Tainan City, Taiwan
- Department of Pediatrics, Taipei Medical University, Xinyi District, Taipei City, Taiwan
| | - Yu-Min Kuo
- Department of Cell Biology and Anatomy, National Cheng Kung University, North District, Tainan City, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University, North District, Tainan City, Taiwan
| | - Shang-Hsun Yang
- Institute of Basic Medical Sciences, National Cheng Kung University, North District, Tainan City, Taiwan
- Department of Physiology, National Cheng Kung University, North District, Tainan City, Taiwan
| | - Yuh-Ling Chen
- Institute of Oral Medicine, National Cheng Kung University, North District, Tainan City, Taiwan
| | - Sheng-Che Lin
- Division of Plastic Surgery, National Cheng Kung University Hospital, North District, Tainan City, Taiwan
| | - Chao-Ching Huang
- Institute of Clinical Medicine, National Cheng Kung University, North District, Tainan City, Taiwan
- Department of Pediatrics, Taipei Medical University, Xinyi District, Taipei City, Taiwan
- Department of Pediatrics, Wan-fan Hospital, College of Medicine, Taipei Medical University, Xinyi District, Taipei City, Taiwan
| | - Chia-Ching Wu
- Department of Cell Biology and Anatomy, National Cheng Kung University, North District, Tainan City, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University, North District, Tainan City, Taiwan
- Department of Biomedical Engineering, National Cheng Kung University, North District, Tainan City, Taiwan
- Medical Device Innovation Center, National Cheng Kung University, North District, Tainan City, Taiwan
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Huang CW, Huang CC, Chen YL, Fan SC, Hsueh YY, Ho CJ, Wu CC. Shear Stress Induces Differentiation of Endothelial Lineage Cells to Protect Neonatal Brain from Hypoxic-Ischemic Injury through NRP1 and VEGFR2 Signaling. Biomed Res Int 2015; 2015:862485. [PMID: 26509169 PMCID: PMC4609802 DOI: 10.1155/2015/862485] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Revised: 06/30/2015] [Accepted: 07/01/2015] [Indexed: 11/18/2022]
Abstract
Neonatal hypoxic-ischemic (HI) brain injuries disrupt the integrity of neurovascular structure and lead to lifelong neurological deficit. The devastating damage can be ameliorated by preserving the endothelial network, but the source for therapeutic cells is limited. We aim to evaluate the beneficial effect of mechanical shear stress in the differentiation of endothelial lineage cells (ELCs) from adipose-derived stem cells (ASCs) and the possible intracellular signals to protect HI injury using cell-based therapy in the neonatal rats. The ASCs expressed early endothelial markers after biochemical stimulation of endothelial growth medium. The ELCs with full endothelial characteristics were accomplished after a subsequential shear stress application for 24 hours. When comparing the therapeutic potential of ASCs and ELCs, the ELCs treatment significantly reduced the infarction area and preserved neurovascular architecture in HI injured brain. The transplanted ELCs can migrate and engraft into the brain tissue, especially in vessels, where they promoted the angiogenesis. The activation of Akt by neuropilin 1 (NRP1) and vascular endothelial growth factor receptor 2 (VEGFR2) was important for ELC migration and following in vivo therapeutic outcomes. Therefore, the current study demonstrated importance of mechanical factor in stem cell differentiation and showed promising protection of brain from HI injury using ELCs treatment.
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Affiliation(s)
- Chia-Wei Huang
- Institute of Basic Medical Sciences, National Cheng Kung University, No. 1 Daxue Road, Tainan 701, Taiwan
| | - Chao-Ching Huang
- Institute of Clinical Medicine, National Cheng Kung University, No. 1 Daxue Road, Tainan 701, Taiwan
- Department of Pediatrics, Taipei Medical University, No. 250 Wuxing Street, Taipei 110, Taiwan
| | - Yuh-Ling Chen
- Institute of Oral Medicine, National Cheng Kung University, No. 1 Daxue Road, Tainan 701, Taiwan
| | - Shih-Chen Fan
- Department of Occupational Therapy, I-Shou University, No. 1 Syuecheng Road, Kaohsiung 824, Taiwan
| | - Yuan-Yu Hsueh
- Division of Plastic Surgery, National Cheng Kung University Hospital, No. 138 Sheng Li Road, Tainan 701, Taiwan
| | - Chien-Jung Ho
- Institute of Clinical Medicine, National Cheng Kung University, No. 1 Daxue Road, Tainan 701, Taiwan
| | - Chia-Ching Wu
- Institute of Basic Medical Sciences, National Cheng Kung University, No. 1 Daxue Road, Tainan 701, Taiwan
- Department of Cell Biology and Anatomy, National Cheng Kung University, No. 1 Daxue Road, Tainan 701, Taiwan
- Department of Biomedical Engineering, National Cheng Kung University, No. 1 Daxue Road, Tainan 701, Taiwan
- International Research Center for Wound Regeneration and Repair, National Cheng Kung University, No. 1 Daxue Road, Tainan 701, Taiwan
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Tu YF, Lin CH, Lee HT, Yan JJ, Sze CI, Chou YP, Ho CJ, Huang CC. Elevated cerebrospinal fluid endothelin 1 associated with neurogenic pulmonary edema in children with enterovirus 71 encephalitis. Int J Infect Dis 2015; 34:105-11. [PMID: 25820093 DOI: 10.1016/j.ijid.2015.03.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/04/2015] [Accepted: 03/21/2015] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVES Neurogenic pulmonary edema (NPE) is a fatal complication in children with enterovirus 71 (EV71) encephalitis. Endothelin 1 (ET-1), a potent vasoconstrictor, can induce pulmonary edema in rats via intrathecal injections. Thus, it was hypothesized that ET-1 in the central nervous system may correlate with NPE in children with EV71 encephalitis. METHODS Clinical data and ET-1 in the cerebrospinal fluid (CSF) were compared between three groups: (1) EV71 encephalitis with NPE; (2) EV71 encephalitis without NPE; and (3) non-EV71 aseptic meningitis. ET-1 immunostaining was performed on the brainstem of autopsy patients. RESULTS The EV71 with NPE group showed significantly increased CSF levels of ET-1 compared to the EV71 without NPE and the non-EV71 aseptic meningitis groups (both p<0.01). The optimum cut-off point of ET-1 to predict NPE in EV71 patients, based on the receiver operating characteristic curve, was 0.5 pg/ml (sensitivity 83%, specificity 100%). Immunostaining in the brainstem showed increased ET-1 expression, mainly in the oligodendrocytes, in EV71 with NPE patients compared with control patients. CONCLUSION ET-1 in the central nervous system may play a role in the development of NPE in children with EV71 infection and could be used as a biomarker or therapeutic target for NPE in EV71 encephalitis.
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Affiliation(s)
- Yi-Fang Tu
- Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70403, Taiwan.
| | - Chih-Hao Lin
- Department of Emergency Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Hsueh-Te Lee
- Institute of Anatomy and Cell Biology, National Yang Ming University, Taipei, Taiwan
| | - Jing-Jou Yan
- Department of Pathology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chun-I Sze
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Ya-Ping Chou
- Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70403, Taiwan
| | - Chien-Jung Ho
- Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70403, Taiwan
| | - Chao-Ching Huang
- Department of Pediatrics, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70403, Taiwan; Department of Pediatrics, Wan-Fang Hospital, College of Medicine, Taipei Medical University, Taipei, Taiwan
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Wang LW, Chang YC, Chen SJ, Tseng CH, Tu YF, Liao NS, Huang CC, Ho CJ. TNFR1-JNK signaling is the shared pathway of neuroinflammation and neurovascular damage after LPS-sensitized hypoxic-ischemic injury in the immature brain. J Neuroinflammation 2014; 11:215. [PMID: 25540015 PMCID: PMC4300587 DOI: 10.1186/s12974-014-0215-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 12/04/2014] [Indexed: 01/13/2023] Open
Abstract
Background Hypoxic-ischemia (HI) and inflammation are the two major pathogenic mechanisms of brain injury in very preterm infants. The neurovascular unit is the major target of HI injury in the immature brain. Systemic inflammation may worsen HI by up-regulating neuroinflammation and disrupting the blood–brain barrier (BBB). Since neurons and oligodendrocytes, microvascular endothelial cells, and microglia may closely interact with each other, there may be a common signaling pathway leading to neuroinflammation and neurovascular damage after injury in the immature brain. TNF-α is a key pro-inflammatory cytokine that acts through the TNF receptor (TNFR), and c-Jun N-terminal kinases (JNK) are important stress-responsive kinases. Objective To determine if TNFR1-JNK signaling is a shared pathway underlying neuroinflammation and neurovascular injury after lipopolysaccharide (LPS)-sensitized HI in the immature brain. Methods Postpartum (P) day-5 mice received LPS or normal saline (NS) injection before HI. Immunohistochemistry, immunoblotting and TNFR1- and TNFR2-knockout mouse pups were used to determine neuroinflammation, BBB damage, TNF-α expression, JNK activation, and cell apoptosis. The cellular distribution of p-JNK, TNFR1/TNFR2 and cleaved caspase-3 were examined using immunofluorescent staining. Results The LPS + HI group had significantly greater up-regulation of activated microglia, TNF-α and TNFR1 expression, and increases of BBB disruption and cleaved caspase-3 levels at 24 hours post-insult, and showed more cortical and white matter injury on P17 than the control and NS + HI groups. Cleaved caspase-3 was highly expressed in microvascular endothelial cells, neurons, and oligodendroglial precursor cells. LPS-sensitized HI also induced JNK activation and up-regulation of TNFR1 but not TNFR2 expression in the microglia, endothelial cells, neurons, and oligodendrocyte progenitors, and most of the TNFR1-positive cells co-expressed p-JNK. Etanercept (a TNF-α inhibitor) and AS601245 (a JNK inhibitor) protected against LPS-sensitized HI brain injury. The TNFR1-knockout but not TNFR2-knockout pups had significant reduction in JNK activation, attenuation of microglial activation, BBB breakdown and cleaved caspase-3 expression, and showed markedly less cortical and white matter injury than the wild-type pups after LPS-sensitized HI. Conclusion TNFR1-JNK signaling is the shared pathway leading to neuroinflammation and neurovascular damage after LPS-sensitized HI in the immature brain. Electronic supplementary material The online version of this article (doi:10.1186/s12974-014-0215-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lan-Wan Wang
- Department of Pediatrics, Chi Mei Medical Center, Tainan, 710, Taiwan. .,Department of Pediatrics, College of Medicine, Taipei Medical University, #250, Wu-Hsing Street, Taipei, 11031, Taiwan. .,Department of Pediatrics, School of Medicine, Chung Shan Medical University, Taichung, 402, Taiwan.
| | - Ying-Chao Chang
- Department of Pediatrics, Chang Gung Memorial Hospital - Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, 833, Taiwan.
| | - Shyi-Jou Chen
- Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei, 114, Taiwan.
| | - Chien-Hang Tseng
- Department of Pediatrics, College of Medicine, National Cheng Kung University Hospital, National Cheng Kung University, Tainan, 704, Taiwan.
| | - Yi-Fang Tu
- Department of Pediatrics, College of Medicine, National Cheng Kung University Hospital, National Cheng Kung University, Tainan, 704, Taiwan.
| | - Nan-Shih Liao
- Institute of Molecular Biology, Academia Sinica, Taipei, 115, Taiwan.
| | - Chao-Ching Huang
- Department of Pediatrics, College of Medicine, Taipei Medical University, #250, Wu-Hsing Street, Taipei, 11031, Taiwan. .,Department of Pediatrics, Wan-Fang Hospital, Taipei Medical University, Taipei, 110, Taiwan. .,Department of Pediatrics, College of Medicine, National Cheng Kung University Hospital, National Cheng Kung University, Tainan, 704, Taiwan.
| | - Chien-Jung Ho
- Department of Pediatrics, College of Medicine, National Cheng Kung University Hospital, National Cheng Kung University, Tainan, 704, Taiwan.
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Hsu YC, Chang YC, Lin YC, Sze CI, Huang CC, Ho CJ. Cerebral microvascular damage occurs early after hypoxia-ischemia via nNOS activation in the neonatal brain. J Cereb Blood Flow Metab 2014; 34:668-76. [PMID: 24398931 PMCID: PMC3982088 DOI: 10.1038/jcbfm.2013.244] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 12/16/2013] [Indexed: 11/09/2022]
Abstract
Microvascular injury early after hypoxic ischemia (HI) may contribute to neonatal brain damage. N-methyl-D-aspartate receptor overstimulation activates neuronal nitric oxide synthases (nNOS). We hypothesized that microvascular damage occurs early post-HI via nNOS activation and contributes to brain injury. Postpartum day-7 rat pups were treated with 7-nitroindazole (7-NI) or aminoguanidine (AG) before or after HI. Electron microscopy was performed to measure neuronal and endothelial cell damage. There were vascular lumen narrowing at 1 hour, pyknotic neurons at 3 hours, and extensive neuronal damage and loss of vessels at 24 hours post HI. Early after reoxygenation, there were neurons with heterochromatic chromatin and endothelial cells with enlarged nuclei occluding the lumen. There was also increased 3-nitrotyrosin in the microvessels and decreased cerebral blood perfusion. 7-NI and AG treatment before hypoxia provided complete and partial neuroprotection, respectively. Early post-reoxygenation, the AG group showed significantly increased microvascular nitrosative stress, microvascular interruptions, swollen nuclei that narrowed the vascular lumen, and decreased cerebral perfusion. The 7-NI group showed significantly decreased microvascular nitrosative stress, patent vascular lumen, and increased cerebral perfusion. Our results indicate that microvascular damage occurs early and progressively post HI. Neuronal nitric oxide synthases activation contributes to microvascular damage and decreased cerebral perfusion early after reoxygenation and worsens brain damage.
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Affiliation(s)
- Yi-Ching Hsu
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan City, Taiwan
| | - Ying-Chao Chang
- Department of Pediatrics, Chang Gung Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung City, Taiwan
| | - Yung-Chieh Lin
- 1] Institute of Clinical Medicine, National Cheng Kung University Medical College, Tainan City, Taiwan [2] Department of Pediatrics, National Cheng Kung University Hospital, Tainan City, Taiwan
| | - Chun-I Sze
- Institute of Cell Biology and Anatomy, National Cheng Kung University Medical College, Tainan City, Taiwan
| | - Chao-Ching Huang
- 1] Department of Pediatrics, National Cheng Kung University Hospital, Tainan City, Taiwan [2] Department of Pediatrics, Taipei Medical University, College of Medicine, Taipei, Taiwan
| | - Chien-Jung Ho
- Department of Pediatrics, National Cheng Kung University Hospital, Tainan City, Taiwan
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Wu CC, Chen YC, Chang YC, Wang LW, Lin YC, Chiang YL, Ho CJ, Huang CC. Human umbilical vein endothelial cells protect against hypoxic-ischemic damage in neonatal brain via stromal cell-derived factor 1/C-X-C chemokine receptor type 4. Stroke 2013; 44:1402-9. [PMID: 23449265 DOI: 10.1161/strokeaha.111.000719] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE Agents that protect against neurovascular damage provide a powerful neuroprotective strategy. Human umbilical vein endothelial cells (HUVECs) may be used to treat neonates with hypoxic-ischemia (HI) because of its autologous capability. We hypothesized that peripherally injected HUVECs entered the brain after HI, protected against neurovascular damage, and provided protection via stromal cell-derived factor 1/C-X-C chemokine receptor type 4 pathway in neonatal brain. METHODS Postpartum day 7 rat pups received intraperitoneal injections of low-passage HUVEC-P4, high-passage HUVEC-P8, or conditioned medium before and immediately after HI. HUVECs were transfected with adenovirus-green fluorescent protein for cell tracing. Oxygen-glucose deprivation was established by coculturing HUVEC-P4 with mouse neuroblastoma neuronal cells (Neuro-2a) and with mouse immortalized cerebral vascular endothelial cells (b.End3). RESULTS HUVEC-P4-treated group had more blood levels of green fluorescent protein-positive cells than HUVEC-P8-treated group 3 hours postinjection. Intraperitoneally injected HUVEC-P4, but not HUVEC-P8, entered the cortex after HI and positioned closed to the neurons and microvessels. Compared with the condition medium-treated group, the HUVEC-P4-treated but not the HUVEC-P8-treated group showed significantly less neuronal apoptosis and blood-brain barrier damage and more preservation of microvessels in the cortex 24 hours after HI. On postpartum day 14, the HUVEC-P4-treated group showed significant neuroprotection compared with the condition medium-treated group. Stromal cell-derived factor 1 was upregulated in the ipsilateral cortex 3 hours after HI, and inhibiting the stromal cell-derived factor 1/C-X-C chemokine receptor type 4 reduced the protective effect of HUVEC-P4. In vitro transwell coculturing of HUVEC-P4 also significantly protected against oxygen-glucose deprivation cell death in neurons and endothelial cells. CONCLUSIONS Cell therapy using HUVECs may provide a powerful therapeutic strategy in treating neonates with HI.
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Affiliation(s)
- Chia-Ching Wu
- Department of Cell Biology and Anatomy, National Cheng Kung University Hospital, No. 138 Sheng-Li Rd, Tainan City 704, Taiwan
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Lin WY, Chang YC, Ho CJ, Huang CC. Ischemic preconditioning reduces neurovascular damage after hypoxia-ischemia via the cellular inhibitor of apoptosis 1 in neonatal brain. Stroke 2012. [PMID: 23192759 DOI: 10.1161/strokeaha.112.677617] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
BACKGROUND AND PURPOSE The neurovascular unit is a major target of hypoxia-ischemia (HI) injury in the neonatal brain. Although neurons are the cellular target of ischemic preconditioning (IP), vessel tolerance also contributes greatly to protection. Nerves and vessels cross-talk and use common signals during development. Cellular inhibitor of apoptosis 1 (cIAP1) is an important regulator that inhibits apoptosis. This study hypothesized that cIAP1 is a shared molecule underlying IP-mediated neurovascular protection against HI in the neonatal brain. METHODS In vivo IP was induced by 2-hour reversible occlusion of right carotid artery 24 hours before HI on postpartum day 7 in rat pups. In vitro oxygen-glucose deprivation (OGD) preconditioning was established in SH-SY5Y neuronal cells and in human microvascular endothelial cell-1 vascular endothelial cells. cIAP1 expression was inhibited by cIAP1 small interfering RNA in vivo or by lentivirus-mediated short hairpin RNA in vitro, or was upregulated by the lentiviral expression system. RESULTS IP reduced apoptosis, selectively increased cIAP1 in neurons and vascular endothelial cells, and provided long-term neuroprotection against HI. Intracerebroventricular delivery of cIAP1 small interfering RNA significantly attenuated IP-mediated cIAP1 upregulation and neuroprotection in vivo. In vitro, OGD preconditioning induced cIAP1 and protected against OGD cell death in SH-SY5Y neuronal and human microvascular endothelial cells-1. Knockdown of cIAP1 by lentivirus-mediated short hairpin RNA decreased the protective effect of OGD preconditioning in SH-SY5Y and human microvascular endothelial cell-1, whereas overexpression of cIAP1 by lentivirus protected against OGD in these cells. CONCLUSIONS cIAP1 is a shared molecule underlying IP-induced protection in neurons and vascular endothelial cells against HI in the neonatal brain.
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Affiliation(s)
- Wan-Ying Lin
- Department of Pediatrics, National Cheng Kung University Hospital, No. 138 Sheng-Li Rd, Tainan City 704, Taiwan
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Wang LW, Tu YF, Huang CC, Ho CJ. JNK signaling is the shared pathway linking neuroinflammation, blood-brain barrier disruption, and oligodendroglial apoptosis in the white matter injury of the immature brain. J Neuroinflammation 2012; 9:175. [PMID: 22805152 PMCID: PMC3414763 DOI: 10.1186/1742-2094-9-175] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 07/17/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND White matter injury is the major form of brain damage in very preterm infants. Selective white matter injury in the immature brain can be induced by lipopolysaccharide (LPS)-sensitized hypoxic-ischemia (HI) in the postpartum (P) day 2 rat pups whose brain maturation status is equivalent to that in preterm infants less than 30 weeks of gestation. Neuroinflammation, blood-brain barrier (BBB) damage and oligodendrocyte progenitor apoptosis may affect the susceptibility of LPS-sensitized HI in white matter injury. c-Jun N-terminal kinases (JNK) are important stress-responsive kinases in various forms of insults. We hypothesized that LPS-sensitized HI causes white matter injury through JNK activation-mediated neuroinflammation, BBB leakage and oligodendroglial apoptosis in the white matter of P2 rat pups. METHODS P2 pups received LPS (0.05 mg/kg) or normal saline injection followed by 90-min HI. Immunohistochemistry and immunoblotting were used to determine microglia activation, TNF-α, BBB damage, cleaved caspase-3, JNK and phospho-JNK (p-JNK), myelin basic protein (MBP), and glial fibrillary acidic protein (GFAP) expression. Immunofluorescence was performed to determine the cellular distribution of p-JNK. Pharmacological and genetic approaches were used to inhibit JNK activity. RESULTS P2 pups had selective white matter injury associated with upregulation of activated microglia, TNF-α, IgG extravasation and oligodendroglial progenitor apoptosis after LPS-sensitized HI. Immunohistochemical analyses showed early and sustained JNK activation in the white matter at 6 and 24 h post-insult. Immunofluorescence demonstrated upregulation of p-JNK in activated microglia, vascular endothelial cells and oligodendrocyte progenitors, and also showed perivascular aggregation of p-JNK-positive cells around the vessels 24 h post-insult. JNK inhibition by AS601245 or by antisense oligodeoxynucleotides (ODN) significantly reduced microglial activation, TNF-α immunoreactivity, IgG extravasation, and cleaved caspase-3 in the endothelial cells and oligodendrocyte progenitors, and also attenuated perivascular aggregation of p-JNK-positive cells 24 h post-insult. The AS601245 or JNK antisense ODN group had significantly increased MBP and decreased GFAP expression in the white matter on P11 than the vehicle or scrambled ODN group. CONCLUSIONS LPS-sensitized HI causes white matter injury through JNK activation-mediated upregulation of neuroinflammation, BBB leakage and oligodendrocyte progenitor apoptosis in the immature brain.
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Affiliation(s)
- Lan-Wan Wang
- Institute of Clinical Medicine, National Cheng Kung University College of Medicine, 35 Hsiao-Tung Road, North District, 704, Tainan, Taiwan
- Department of Pediatrics, Chi Mei Medical Center, 901 Chung-Hua Road, Yung-Kang Disctrict, 710, Tainan, Taiwan
| | - Yi-Fang Tu
- Departments of Emergency Medicine, National Cheng Kung University College of Medicine and Hospital, 138 Sheng-Li Road, 704, Tainan, Taiwan
| | - Chao-Ching Huang
- Institute of Clinical Medicine, National Cheng Kung University College of Medicine, 35 Hsiao-Tung Road, North District, 704, Tainan, Taiwan
- Departments of Pediatrics, National Cheng Kung, University College of Medicine and Hospital, 138 Sheng-Li Road, 704, Tainan, Taiwan
| | - Chien-Jung Ho
- Departments of Pediatrics, National Cheng Kung, University College of Medicine and Hospital, 138 Sheng-Li Road, 704, Tainan, Taiwan
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Tu YF, Lu PJ, Huang CC, Ho CJ, Chou YP. Moderate dietary restriction reduces p53-mediated neurovascular damage and microglia activation after hypoxic ischemia in neonatal brain. Stroke 2011; 43:491-8. [PMID: 22076005 DOI: 10.1161/strokeaha.111.629931] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
BACKGROUND AND PURPOSE Neurovascular damage, including neuronal apoptosis and blood-brain barrier (BBB) damage, and microglia activation account for the hypoxic-ischemia (HI) susceptibility in neonatal brain. The p53 upregulation is involved in apoptosis, endothelial cell damage, and microglia activation. We hypothesized that underweight induced by dietary restriction (DR) protects against HI in rat pups by attenuating p53-mediated neurovascular damage. METHODS Male rat pups were grouped as normal litter (NL) size (12 pups/dam), DR (18 pups/dam), and extreme DR (24 pups/dam) from postnatal day 1 and subjected to HI on postnatal day 7. Immunohistochemistry and immunoblotting were used to determine p53, phospho-murine double minute-2, caspases, BBB damage and microglia activation, and immunofluorescence to determine the cellular distribution of p53. Pharmacological approaches were used to regulate p53. RESULTS The NL, DR, and extreme DR pups had similar TUNEL-positive cells and caspases on postnatal day 7 and comparable learning performance at adulthood. After HI, the DR-HI, but not extreme DR-HI, pups had significantly lower p53, higher phospho-murine double minute-2, lower cleaved caspases, less BBB damage and microglia activation, and less brain volume loss than NL-HI pups. In NL-HI pups, p53 expression was located mainly in the neurons, endothelial cells, and microglia. The p53 blockage by pifithrin-α in NL-HI pups decreased apoptosis, BBB damage, and microglia activation, and was neuroprotective. In contrast, upregulating p53 by nutlin-3 in DR-HI pups increased apoptosis, BBB damage, and microglia activation, and worsened brain damage. CONCLUSIONS Moderate DR, but not extreme DR, reduces p53-mediated neurovascular damage after HI and confers long-term protection in neonatal brain.
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Affiliation(s)
- Yi-Fang Tu
- Institute of Clinical Medicine, National Cheng Kung University, Medical College and Hospital, Tainan, Taiwan
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Tu YF, Tsai YS, Wang LW, Wu HC, Huang CC, Ho CJ. Overweight worsens apoptosis, neuroinflammation and blood-brain barrier damage after hypoxic ischemia in neonatal brain through JNK hyperactivation. J Neuroinflammation 2011; 8:40. [PMID: 21518436 PMCID: PMC3090337 DOI: 10.1186/1742-2094-8-40] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Accepted: 04/25/2011] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Apoptosis, neuroinflammation and blood-brain barrier (BBB) damage affect the susceptibility of the developing brain to hypoxic-ischemic (HI) insults. c-Jun N-terminal kinase (JNK) is an important mediator of insulin resistance in obesity. We hypothesized that neonatal overweight aggravates HI brain damage through JNK hyperactivation-mediated upregulation of neuronal apoptosis, neuroinflammation and BBB leakage in rat pups. METHODS Overweight (OF) pups were established by reducing the litter size to 6, and control (NF) pups by keeping the litter size at 12 from postnatal (P) day 1 before HI on P7. Immunohistochemistry and immunoblotting were used to determine the TUNEL-(+) cells and BBB damage, cleaved caspase-3 and poly (ADP-ribose) polymerase (PARP), and phospho-JNK and phospho-BimEL levels. Immunofluorescence was performed to determine the cellular distribution of phospho-JNK. RESULTS Compared with NF pups, OF pups had a significantly heavier body-weight and greater fat deposition on P7. Compared with the NF-HI group, the OF-HI group showed significant increases of TUNEL-(+) cells, cleaved levels of caspase-3 and PARP, and ED1-(+) activated microglia and BBB damage in the cortex 24 hours post-HI. Immunofluorescence of the OF-HI pups showed that activated-caspase 3 expression was found mainly in NeuN-(+) neurons and RECA1-(+) vascular endothelial cells 24 hours post-HI. The OF-HI group also had prolonged escape latency in the Morris water maze test and greater brain-volume loss compared with the NF-HI group when assessed at adulthood. Phospho-JNK and phospho-BimEL levels were higher in OF-HI pups than in NF-HI pups immediately post-HI. JNK activation in OF-HI pups was mainly expressed in neurons, microglia and vascular endothelial cells. Inhibiting JNK activity by AS601245 caused more attenuation of cleaved caspase-3 and PARP, a greater reduction of microglial activation and BBB damage post-HI, and significantly reduced brain damage in OF-HI than in NF-HI pups. CONCLUSIONS Neonatal overweight increased HI-induced neuronal apoptosis, microglial activation and BBB damage, and aggravated HI brain damage in rat pups through JNK hyperactivation.
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Affiliation(s)
- Yi-Fang Tu
- Institute of Clinical Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan
- Department of Emergency Medicine, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan
| | - Yau-Sheng Tsai
- Institute of Clinical Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan
| | - Lan-Wan Wang
- Institute of Clinical Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan
- Department of Pediatrics, Chi Mei Medical Center, Tainan, Taiwan
| | - Hsin-Chieh Wu
- Department of Pediatrics, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan
| | - Chao-Ching Huang
- Institute of Clinical Medicine, National Cheng Kung University College of Medicine, Tainan, Taiwan
- Department of Pediatrics, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan
| | - Chien-Jung Ho
- Department of Pediatrics, National Cheng Kung University College of Medicine and Hospital, Tainan, Taiwan
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Chang YC, Tzeng SF, Yu L, Huang AM, Lee HT, Huang CC, Ho CJ. Early-life fluoxetine exposure reduced functional deficits after hypoxic-ischemia brain injury in rat pups. Neurobiol Dis 2006; 24:101-13. [PMID: 16887358 DOI: 10.1016/j.nbd.2006.06.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2006] [Revised: 05/24/2006] [Accepted: 06/05/2006] [Indexed: 11/21/2022] Open
Abstract
Neuroplasticity after perinatal programming may allow for neuroprotection against hypoxic-ischemia (HI) at birth. The cAMP response element-binding protein (CREB) is a key mediator of stimulus-induced nuclear responses that underlie survival, memory and plasticity of nervous system. Chronic treatment of fluoxetine, a selective serotonin reuptake inhibitor, can upregulate CREB activation in the hippocampus. We examined whether fluoxetine administration before HI may protect against neonatal HI brain injury through CREB-mediated mechanisms. We found that low-dose fluoxetine pretreatment in a neonatal HI brain injury model significantly reduced functional deficits at adulthood. The neuroprotective mechanisms were associated with increased CREB phosphorylation and increased brain-derived neurotrophic factor and synapsin I mRNA expression in the hippocampus. Neurogenesis also increased because of greater precursor cell survival in the hippocampal dentate gyrus. These findings suggest that functional deficits after HI in the developing brain can be reduced by agents that enhance neural plasticity and neurogenesis through CREB activation.
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Affiliation(s)
- Ying-Chao Chang
- Department of Pediatrics, Chang Gung Memorial Hospital-Kaohsiung Medical Center, Chang Guang University College of Medicine, Kaohsiung, Taiwan
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12
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Lee HT, Chang YC, Wang LY, Wang ST, Huang CC, Ho CJ. cAMP response element-binding protein activation in ligation preconditioning in neonatal brain. Ann Neurol 2005; 56:611-23. [PMID: 15470752 DOI: 10.1002/ana.20259] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Perinatal hypoxic-ischemic (HI) brain injury is a major cause of permanent neurological dysfunction in children. An approach to study the treatment of neonatal HI encephalopathy that allows for neuroprotection is to investigate the states of tolerance to HI. Twenty-four-hour carotid-artery ligation preconditioning established by delaying the onset of hypoxia for 24 hours after permanent unilateral carotid ligation rats markedly diminished the cerebral injury, however, the signaling mechanisms of this carotid-artery ligation preconditioning in neonatal rats remain unknown. Ligation of the carotid artery 24 hours before hypoxia provided complete neuroprotection and produced improved performance on the Morris water maze compared with ligation performed 1 hour before hypoxia. Carotid artery ligation 6 hours before hypoxia produced intermediate benefit. The 24-hour carotid-artery ligation preconditioning was associated with a robust and sustained activation of a transcription factor, the cAMP response element-binding protein (CREB), on its phosphorylation site on Ser133. Intracerebroventricular infusions of antisense CREB oligodeoxynucleotides significantly reduced the 24-hour carotid-artery ligation-induced neuroprotection effects by decreasing CREB expressions. Pharmacological activation of the cAMP-CREB signaling with rolipram 24 hours before hypoxia protected rat pups at behavioral and pathological levels by sustained increased CREB phosphorylation. This study suggests that 24-hour carotid-artery ligation preconditioning provides important mechanisms for potential pharmacological preconditioning against neonatal HI brain injury.
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MESH Headings
- Analysis of Variance
- Animals
- Animals, Newborn
- Autoradiography/methods
- Behavior, Animal
- Blotting, Western/methods
- Brain-Derived Neurotrophic Factor/genetics
- Brain-Derived Neurotrophic Factor/metabolism
- Carotid Stenosis
- Cerebrovascular Circulation/physiology
- Colforsin/pharmacology
- Cyclic AMP Response Element-Binding Protein/antagonists & inhibitors
- Cyclic AMP Response Element-Binding Protein/metabolism
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Enzyme Activation
- Female
- Fetal Hypoxia/enzymology
- Fetal Hypoxia/metabolism
- Fetal Hypoxia/prevention & control
- Functional Laterality
- Hypoxia-Ischemia, Brain/enzymology
- Hypoxia-Ischemia, Brain/metabolism
- Hypoxia-Ischemia, Brain/prevention & control
- Immunohistochemistry/methods
- Ischemic Preconditioning/methods
- Ligation/methods
- Male
- Maze Learning/physiology
- Oligodeoxyribonucleotides, Antisense/therapeutic use
- Organ Size/physiology
- Phosphodiesterase Inhibitors/pharmacology
- Phosphorylation
- RNA, Messenger/biosynthesis
- Rats
- Reaction Time/physiology
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Rolipram/pharmacology
- Serine/metabolism
- Time Factors
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Affiliation(s)
- Hsueh-Te Lee
- Institute of Basic Medical Science, Medical College, National Cheng Kung University, Tainan, Taiwan
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13
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Lin SY, Ho CJ, Li MJ. Precision and reproducibility of temperature response of a thermo-responsive membrane embedded by binary liquid crystals for drug delivery. J Control Release 2001; 73:293-301. [PMID: 11516506 DOI: 10.1016/s0168-3659(01)00300-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A thermo-responsive membrane embedding with the binary mixture of 36% cholesteryl oleyl carbonate (COC) and 64% cholesteryl nonanoate (CN) was successfully developed to achieve a rate-controlled and time-controlled drug release in response to the skin temperature (i.e., 32 degrees C) of the human body. The thermophysical properties of this binary mixture were determined by differential scanning calorimetry (DSC) and a microscopic Fourier transform infrared (FT-IR) spectrometer equipped with a thermal analyzer (FT-IR/DSC microscopic system). The phase transition temperatures of this binary mixture at 35.1 and 64.0 degrees C were clearly evidenced by both analytical methods. The temperature response of this binary mixture of COC and CN with 36%:64% ratio were also investigated for eight cycles by the isothermal FT-IR/DSC microscopic system to continuously and repeatedly alter the temperature cycle between 25 and 37 degrees C. The results show that this binary mixture revealed a good temperature response in precision, sensitivity, obedience and reproducibility. The temperature-sensitive on-off pulsatile function of drug penetration through this thermo-responsive membrane was investigated. The switching mechanism of this thermo-responsive membrane was also proposed. The present result strongly indicates that the binary COC-CN mixture-embedded membrane can be used to deliver the drug in a pulsatile fashion with respect to skin temperature.
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Affiliation(s)
- S Y Lin
- Biopharmaceutics Laboratory, Department of Medical Research and Education, Veterans General Hospital-Taipei, Taipei, Taiwan.
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Abstract
The changes in turbidity and protein secondary structure of alpha-crystallin after a 72 h UV-B (302 nm) irradiation in aqueous solution have been determined by UV spectrophotometry and Fourier transform infrared (FT-IR) microspectroscopy with reflection mode. The relative transmission of alpha-crystallin aqueous solution gradually decreases with the exposure time, indicating that the transparent alpha-crystallin aqueous solution becomes opaque with prolonged UV-B irradiation. The turbidity induced by UV-B shows first-order kinetics due to the photo-induced aggregation. The modification of the secondary structure of the alpha-crystallin molecule in aqueous solution caused by this aggregation might enhance the alpha-helix and beta-turn structures from 8.14 to 14.92% and from 24.46 to 35.54%, respectively; reduce the beta-sheet structure from 60.20% to 43.77%; and leave the random coil structure almost unaltered. The secondary conformation of alpha-crystallin changes gradually but evidently with its increase of turbidity during UV-B exposure.
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Affiliation(s)
- S Y Lin
- Department of Medical Research and Education, Veterans General Hospital-Taipei, Taiwan.
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15
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Au LC, Lin SY, Li MJ, Ho CJ. pH-dependent secondary conformation of the peptide hormone leptin in different buffer solutions. Artif Cells Blood Substit Immobil Biotechnol 1999; 27:119-34. [PMID: 10092934 DOI: 10.3109/10731199909117687] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The secondary structure of leptin in each different pH buffer solution (pH 5.35, 6.75, 7.58 and 8.45) was first determined by attenuated total reflection (ATR)/Fourier transform infrared (FT-IR) spectrometer with second-derivative, Fourier self-deconvolution and band curve-fitting methods to quantitatively estimate the secondary structure of leptin. The results indicate that pH induced more stretching vibration of CH2 and bending vibration of C-H and/or symmetric stretching of carboxylate of leptin structure in higher pH buffer solution than in lower pH buffer solution. Moreover, the band area of amide I for leptin in the higher pH buffer solution markedly enlarged, suggesting the amide I contour of leptin was very sensitive to pH to alter the secondary conformation of leptin structure. The structural component and composition of amide I band for leptin in both pH 6.75 and pH 7.58 buffer solutions were similar and had 50-52% helical structure including alpha-helix at 1654 cm-1 and 3(10)-helical structure at 1659-1667 cm-1 and 1640 cm-1. Although the secondary structure of leptin in pH 5.35 and 8.45 buffer solutions were also similar, a different structural information was obtained.
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Affiliation(s)
- L C Au
- Department of Medical Research and Education, Veterans General Hospital-Taipei, Taiwan
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Lin SY, Li MJ, Ho CJ. pH-dependent secondary conformation of bovine lens alpha-crystallin: ATR infrared spectroscopic study with second-derivative analysis. Graefes Arch Clin Exp Ophthalmol 1999; 237:157-60. [PMID: 9987633 DOI: 10.1007/s004170050211] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND In order to simulate the usage of different formulations of ophthalmic solution, the protein conformational changes of lens alpha-crystallin in buffer solutions of different pH were investigated. METHODS The secondary structure of bovine lens alpha-crystallin in different Mcllvaine buffer solutions (pH 2.2, 4.0, 6.0, 7.2 and 8.0) was determined by attenuated total reflection (ATR)/Fourier transform infrared (FT-IR) spectrometry with second-derivative technique. The turbidity of alpha-crystallin in different buffer solutions was observed. RESULTS AND CONCLUSION The results indicate that alpha-crystallin exists mainly in beta-sheet structure at 1627-1637 cm-1. The conformational components of alpha-crystallin may be closely similar in pH 7.2 buffer solution and in pH 8.0 buffer solution. Once alpha-crystallin dissolved in pH 6.0 and 4.0 buffer solution, the appearance of a component at 1618 or 1620 cm-1, associated with the presence of intermolecular beta-sheet structure or beta-turn structure or amino acid side chains, implied the denaturation of alpha-crystallin, which was even more marked in pH 4.0 buffer solution. Due to the effect of dissociation and stability of alpha-crystallin in pH 2.2 buffer solution, the secondary structure of the intact alpha-crystallin was difficult to evaluate. This study demonstrates that different pH can vary secondary conformational structure of alpha-crystallin, particularly if the pH is below 6.0. This suggests that the secondary structure of alpha-crystallin in buffer solution exhibits pH-dependent characteristics.
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Affiliation(s)
- S Y Lin
- Department of Medical Research and Education, Veterans General Hospital Taipei, Taipei, Taiwan, Republic of China.
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Abstract
Reflectance FT-IR/DSC microspectroscopy was first used to study the structural conformation of alpha-crystallin membranes in the heating-cooling-reheating cycle. The thermotropic transition and the changes in secondary structure of alpha-crystallin membrane during heating and reheating processes were investigated. A thermal transition ranging between 50 and 70 degrees C with a midpoint at 60 degrees C for the alpha-crystallin membrane was easily obtained from the three-dimensional plots of the reflectance FT-IR spectra as a function of temperature. The secondary structural components of the alpha-crystallin membrane were modified step-by-step with the increase of temperature from 25 to 120 degrees C, but restored to original values after cooling to 25 degrees C. During the heating process, the compositions of the alpha-helix, random coil and beta-sheet structure decreased with temperature, but the content of the beta-turn structure increased, however, all of them were restored after cooling. The absence of significant alteration in the secondary structures for the alpha-crystallin membrane before and after the first-heating process strongly suggests the high thermal stability and reversibility of alpha-crystallin. Interestingly, the thermal behavior of the first-heated alpha-crystallin membrane during the reheating process exhibited a unique thermal behavior with two transitional temperatures at 35-50 and 55-70 degrees C. The reflectance FT-IR/DSC microscopic data indicated that alpha-crystallin in the membrane state had higher thermal stability and reversibility.
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Affiliation(s)
- S Y Lin
- Department of Medical Research and Education, Veterans General Hospital-Taipei, Taiwan.
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18
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Ho CJ, Tsan KW, Wang CH, Huang CH. [The effect of sex, body build and age with respect to C-peptide]. Zhonghua Yi Xue Za Zhi (Taipei) 1987; 39:105-11. [PMID: 3455313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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