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Bibi T, Bano S, Ud Din F, Ali H, Khan S. Preparation, characterization, and pharmacological application of oral Honokiol-loaded solid lipid nanoparticles for diabetic neuropathy. Int J Pharm 2023; 645:123399. [PMID: 37703961 DOI: 10.1016/j.ijpharm.2023.123399] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/24/2023] [Accepted: 09/08/2023] [Indexed: 09/15/2023]
Abstract
Honokiol is a phytochemical component with a variety of pharmacological properties. However, the major limitation of Honokiol is its poor solubility and low oral bioavailability. In this study, we formulated and characterized oral Honokiol-loaded solid lipid nanoparticles (SLNs) to enhance bioavailability and then evaluated their effectiveness in experimental diabetic neuropathy (DN). The finalized formulation has a spherical morphology, a particle size (PS) of 121.31 ± 9.051 nm, a polydispersity index (PDI) of 0.249 ± 0.002, a zeta potential (ZP) of -20.8 ± 2.72 mV, and an entrapment efficiency (% EE) of 88.66 ± 2.30 %. In-vitro release data shows, Honokiol-SLNs displayed a sustained release profile at pH (7.4). The oral bioavailability of Honokiol-SLNs was remarkably greater (8-fold) than Honokiol-Pure suspension. The neuroprotective property of Honokiol-SLNs was initially demonstrated against hydrogen peroxide H2O2-stimulated PC12 (pheochromocytoma) cells. Furthermore, results of in-vivo studies demonstrated that treatment with Honokiol-SLNs significantly (p < 0.001) suppressed oxidative stress by inhibition of nuclear factor kappa B (NF-κB) and significant (p < 0.001) upregulation of nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling in the spinal cord. The expression of transient receptor potential melastatin 8(TRPM8) and transient receptor potential vanilloid 1 (TRPV1) was significantly (p < 0.001) downregulated. Honokiol-SLNs inhibited apoptosis by significant (p < 0.001) downregulation of cleaved caspase-3 expression in the spinal cord. These findings demonstrate that Honokiol-SLNs providedbetter neuroprotection in DN because of higher oral bioavailability.
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Affiliation(s)
- Tehmina Bibi
- Pharmacological Sciences Research Lab, Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Shahar Bano
- Pharmacological Sciences Research Lab, Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Fakhar Ud Din
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; Nanomedicine Research Group, Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Hussain Ali
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Salman Khan
- Pharmacological Sciences Research Lab, Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan; Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan.
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Ding R, Zhu S, Zhao X, Yue R. Vascular endothelial growth factor levels in diabetic peripheral neuropathy: a systematic review and meta-analysis. Front Endocrinol (Lausanne) 2023; 14:1169405. [PMID: 37251664 PMCID: PMC10213658 DOI: 10.3389/fendo.2023.1169405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 04/28/2023] [Indexed: 05/31/2023] Open
Abstract
Objective Vascular endothelial growth factors (VEGFs, including VEGF-A, VEGF-B, VEGF-C, VEGF-D and PLGF) have important roles in the development and function of the peripheral nervous system. Studies have confirmed that VEGFs, especially VEGF-A (so called VEGF) may be associated with the diabetic peripheral neuropathy (DPN) process. However, different studies have shown inconsistent levels of VEGFs in DPN patients. Therefore, we conducted this meta-analysis to evaluate the relationship between cycling levels of VEGFs and DPN. Methods This study searched 7 databases, including PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), VIP Database, WanFang Database, and Chinese Biomedical Literature (CBM), to find the target researches. The random effects model was used to calculate the overall effect. Results 14 studies with 1983 participants were included, among which 13 studies were about VEGF and 1 was VEGF-B, so only the effects of VEGF were pooled. The result showed that there were obviously increased VEGF levels in DPN patients compared with diabetic patients without DPN (SMD:2.12[1.34, 2.90], p<0.00001) and healthy people (SMD:3.50[2.24, 4.75], p<0.00001). In addition, increased circulating VEGF levels were not associated with an increased risk of DPN (OR:1.02[0.99, 1.05], p<0.00001). Conclusion Compared with healthy people and diabetic patients without DPN, VEGF content in the peripheral blood of DPN patients is increased, but current evidence does not support the correlation between VEGF levels and the risk of DPN. This suggests that VEGF may play a role in the pathogenesis and repairment of DPN.
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Affiliation(s)
- Rui Ding
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Shicong Zhu
- Department of Respiratory, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Xiaoyan Zhao
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Rensong Yue
- Department of Endocrinology, Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, China
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Kim AH, Kolesnikova M, Ngo WK, Tsang SH. Effects of medications on hypoxia-inducible factor in the retina: A review. Clin Exp Ophthalmol 2023; 51:205-216. [PMID: 36594241 DOI: 10.1111/ceo.14161] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/22/2022] [Accepted: 08/26/2022] [Indexed: 01/04/2023]
Abstract
Hypoxia-inducible factor (HIF) plays a critical role in the mechanisms that allow cells to adapt to various oxygen levels in the environment. Specifically, HIF-1⍺ has shown to be widely involved in cellular repair, survival, and energy metabolism. HIF-1⍺ has also been found in increased levels in cancer cells, highlighting the importance of balance in the hypoxic response. Promoting HIF-1⍺ activity as a potential therapy for degenerative diseases and inhibiting HIF-1⍺ as a therapy for pathologies with overactive cell proliferation are actively being explored. Digoxin and metformin, HIF-1⍺ inhibitors, and deferoxamine and ⍺-ketoglutarate analogues, HIF-1⍺ activators, are being studied for application in age-related macular degeneration, diabetic retinopathy, and retinitis pigmentosa. However, these same medications have retinal toxicities that must be assessed before implementation of therapeutic care. Herein, we highlight the duality of therapeutic and toxic potential of HIF-1⍺ that must be carefully assessed prior to its clinical application in retinal disorders.
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Affiliation(s)
- Angela H Kim
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, New York-Presbyterian Hospital, New York, New York, USA.,Edward S. Harkness Eye Institute, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, New York, USA.,SUNY Downstate Medical School, Brooklyn, New York, USA
| | - Masha Kolesnikova
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, New York-Presbyterian Hospital, New York, New York, USA.,Edward S. Harkness Eye Institute, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, New York, USA.,SUNY Downstate Medical School, Brooklyn, New York, USA
| | - Wei Kiong Ngo
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, New York-Presbyterian Hospital, New York, New York, USA.,Edward S. Harkness Eye Institute, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, New York, USA.,National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore, Singapore
| | - Stephen H Tsang
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, New York-Presbyterian Hospital, New York, New York, USA.,Edward S. Harkness Eye Institute, Columbia University Irving Medical Center/New York-Presbyterian Hospital, New York, New York, USA.,Departments of Pathology & Cell Biology, Columbia Stem Cell Initiative, New York, New York, USA.,Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, New York, USA
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Li J, Lu X, Wei L, Ye D, Lin J, Tang X, Cui K, Yu S, Xu Y, Liang X. PHD2 attenuates high-glucose-induced blood retinal barrier breakdown in human retinal microvascular endothelial cells by regulating the Hif-1α/VEGF pathway. Inflamm Res 2021; 71:69-79. [PMID: 34773469 DOI: 10.1007/s00011-021-01518-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 10/20/2021] [Accepted: 10/25/2021] [Indexed: 01/20/2023] Open
Abstract
OBJECTIVE Diabetic macular edema (DME) is one of the most frequent causes of severe vision loss. The pathogenesis of DME is still not fully understood; however, it is hypothesized to result from breakdown of the blood-retinal barrier (BRB) due to retinal inflammation by vascular endothelial growth factor (VEGF) secretion under hyperglycemic conditions. In this investigation, we discovered that Prolyl-4-hydroxylase 2 (PHD2), an upstream regulator of hypoxia-inducible factor 1 (HIF-1) modulates VEGF expression and thus preserves BRB function in the mouse retina. MATERIALS AND METHODS Primary human retinal microvascular endothelial cells (hRMECs) were cultured in human endothelial serum-free growth medium and exposed to hyperglycemia. Changes in cell viability were investigated by an MTT assay. BRB function in each group was revealed by a paracellular permeability assay and trans-endothelial electrical resistance (TEER). Morphological changes in the BRB were investigated by immunofluorescence staining of occludin and zonula occludens-1 (ZO-1). The mRNA and protein levels of the tight junction proteins, PHD2, HIF-1α, and VEGF were measured by reverse transcription-quantitative PCR (RT-qPCR), western blot analysis and ELISA. RESULTS Under hyperglycemic conditions, the viability of hRMECs was decreased, and PHD2 expression was downregulated, accompanied by increased paracellular permeability and decreased trans-endothelial electrical resistance. Additionally, HIF-1α and VEGF expression levels were increased, whereas the expression levels of tight junction proteins, including occludin and ZO-1, were decreased and BRB function was compromised. The PHD2 activator R59949 (diacylglycerol kinase inhibitor II), altered these pathological changes, and the PHD2 inhibitor dimethyloxalylglycine (DMOG) resulted in the opposite effects. CONCLUSION These results demonstrated that PHD2 inhibited HIF-1 activity by inhibiting HIF-1α expression in hRMECs under hyperglycemic conditions, which led to the downregulation of the expression of the angiogenic factor VEGF, and thus helped to maintain the functions of hRMECs. Therefore, it is reasonable to propose that PHD2 could be a potential novel target for the treatment of DME or other diseases with a similar pathogenesis.
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Affiliation(s)
- Jia Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.7 Jinsui Rd, Tianhe District, Guangzhou, Guangdong, People's Republic of China, 510030
| | - Xi Lu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.7 Jinsui Rd, Tianhe District, Guangzhou, Guangdong, People's Republic of China, 510030
| | - Liqing Wei
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.7 Jinsui Rd, Tianhe District, Guangzhou, Guangdong, People's Republic of China, 510030
- Eye Hospital of Wenzhou Medical University, Hangzhou Xihu Zhijiang Eye Hospital, No.7 Jinsui Rd, Hangzhou, Zhejiang, People's Republic of China, 310024
| | - Dan Ye
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.7 Jinsui Rd, Tianhe District, Guangzhou, Guangdong, People's Republic of China, 510030
| | - Jianqiang Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.7 Jinsui Rd, Tianhe District, Guangzhou, Guangdong, People's Republic of China, 510030
| | - Xiaoyu Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.7 Jinsui Rd, Tianhe District, Guangzhou, Guangdong, People's Republic of China, 510030
| | - Kaixuan Cui
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.7 Jinsui Rd, Tianhe District, Guangzhou, Guangdong, People's Republic of China, 510030
| | - Shanshan Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.7 Jinsui Rd, Tianhe District, Guangzhou, Guangdong, People's Republic of China, 510030
| | - Yue Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.7 Jinsui Rd, Tianhe District, Guangzhou, Guangdong, People's Republic of China, 510030.
| | - Xiaoling Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, No.7 Jinsui Rd, Tianhe District, Guangzhou, Guangdong, People's Republic of China, 510030.
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Abstract
Hypoxia can be defined as a relative deficiency in the amount of oxygen reaching the tissues. Hypoxia-inducible factors (HIFs) are critical regulators of the mammalian response to hypoxia. In normal circumstances, HIF-1α protein turnover is rapid, and hyperglycemia further destabilizes the protein. In addition to their role in diabetes pathogenesis, HIFs are implicated in development of the microvascular and macrovascular complications of diabetes. Improving glucose control in people with diabetes increases HIF-1α protein and has wide-ranging benefits, some of which are at least partially mediated by HIF-1α. Nevertheless, most strategies to improve diabetes or its complications via regulation of HIF-1α have not currently proven to be clinically useful. The intersection of HIF biology with diabetes is a complex area in which many further questions remain, especially regarding the well-conducted studies clearly describing discrepant effects of different methods of increasing HIF-1α, even within the same tissues. This Review presents a brief overview of HIFs; discusses the range of evidence implicating HIFs in β cell dysfunction, diabetes pathogenesis, and diabetes complications; and examines the differing outcomes of HIF-targeting approaches in these conditions.
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Affiliation(s)
- Jenny E Gunton
- Centre for Diabetes, Obesity and Endocrinology, Westmead Institute for Medical Research, Westmead, New South Wales, Australia.,Westmead Hospital, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia.,Garvan Institute of Medical Research, Darlinghurst, New South Wales, Australia
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Abstract
Neuropathy is a common complication of long-term diabetes that impairs quality of life by producing pain, sensory loss and limb amputation. The presence of neuropathy in both insulin-deficient (type 1) and insulin resistant (type 2) diabetes along with the slowing of progression of neuropathy by improved glycemic control in type 1 diabetes has caused the majority of preclinical and clinical investigations to focus on hyperglycemia as the initiating pathogenic lesion. Studies in animal models of diabetes have identified multiple plausible mechanisms of glucotoxicity to the nervous system including post-translational modification of proteins by glucose and increased glucose metabolism by aldose reductase, glycolysis and other catabolic pathways. However, it is becoming increasingly apparent that factors not necessarily downstream of hyperglycemia can also contribute to the incidence, progression and severity of neuropathy and neuropathic pain. For example, peripheral nerve contains insulin receptors that transduce the neurotrophic and neurosupportive properties of insulin, independent of systemic glucose regulation, while the detection of neuropathy and neuropathic pain in patients with metabolic syndrome and failure of improved glycemic control to protect against neuropathy in cohorts of type 2 diabetic patients has placed a focus on the pathogenic role of dyslipidemia. This review provides an overview of current understanding of potential initiating lesions for diabetic neuropathy and the multiple downstream mechanisms identified in cell and animal models of diabetes that may contribute to the pathogenesis of diabetic neuropathy and neuropathic pain.
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Wang X, Guo K, Huang B, Lin Z, Cai Z. Role of Glucose Transporters in Drug Membrane Transport. Curr Drug Metab 2020; 21:947-958. [PMID: 32778021 DOI: 10.2174/1389200221666200810125924] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/12/2020] [Accepted: 06/01/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Glucose is the main energy component of cellular activities. However, as a polar molecule, glucose cannot freely pass through the phospholipid bilayer structure of the cell membrane. Thus, glucose must rely on specific transporters in the membrane. Drugs with a similar chemical structure to glucose may also be transported through this pathway. METHODS This review describes the structure, distribution, action mechanism and influencing factors of glucose transporters and introduces the natural drugs mediated by these transporters and drug design strategies on the basis of this pathway. RESULTS The glucose transporters involved in glucose transport are of two major types, namely, Na+-dependent and Na+-independent transporters. Glucose transporters can help some glycoside drugs cross the biological membrane. The transmembrane potential is influenced by the chemical structure of drugs. Glucose can be used to modify drugs and improve their ability to cross biological barriers. CONCLUSION The membrane transport mechanism of some glycoside drugs may be related to glucose transporters. Glucose modification may improve the oral bioavailability of drugs or achieve targeted drug delivery.
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Affiliation(s)
- Xin Wang
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Kunkun Guo
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Baolin Huang
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Zimin Lin
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Zheng Cai
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
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Time-dependent changes in hypoxia- and gliosis-related factors in experimental diabetic retinopathy. Eye (Lond) 2018; 33:600-609. [PMID: 30401898 PMCID: PMC6461831 DOI: 10.1038/s41433-018-0268-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 08/21/2018] [Accepted: 08/30/2018] [Indexed: 01/26/2023] Open
Abstract
Diabetes causes various biochemical changes in the retina; long-term changes in the factors associated with hypoxia and gliosis have rarely been reported. The present study was conducted to explore the changes in these factors in a time-dependent manner in experimental diabetic retinopathy (DR). Diabetes was induced in Sprague-Dawley rats by intraperitoneal injection of streptozotocin. The expression of the following factors was examined using immunofluorescence and western blot analysis at 0.5, 1, 2, 4 and 6 months after diabetes onset: hypoxia-inducible factor-1alpha (HIF-1alpha), vascular endothelial growth factor (VEGF), erythropoietin (EPO), erythropoietin receptor (EPOR), glial fibrillary acidic protein (GFAP), vimentin, glutamate-aspartate transporter (GLAST) and glutamine synthase (GS). The expression of factors such as HIF-1alpha, VEGF, EPO, EPOR, GFAP and vimentin, was up-regulated with the progression of diabetes in the diabetic rat retinas compared to the expression in normal control retinas, whereas the expression of GS and GLAST was down-regulated. Changes in EPO and EPOR appeared 2 weeks after diabetes onset. HIF-1alpha, VEGF and GFAP started to increase at 1 month and vimentin at 4 months after diabetes onset. GS and GLAST started to decrease at 1 month after diabetes onset. The expression of these factors, which are involved in the processes of hypoxia and gliosis, varied at different stages of DR. The time-course change may be helpful in the evaluation of the progression of DR, and it may indicate the optimal intervention time points for DR.
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Guo G, Liu Y, Ren S, Kang Y, Duscher D, Machens HG, Chen Z. Comprehensive analysis of differentially expressed microRNAs and mRNAs in dorsal root ganglia from streptozotocin-induced diabetic rats. PLoS One 2018; 13:e0202696. [PMID: 30118515 PMCID: PMC6097669 DOI: 10.1371/journal.pone.0202696] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Accepted: 08/06/2018] [Indexed: 01/22/2023] Open
Abstract
Diabetic peripheral neuropathy is a common complication associated with diabetes mellitus with a pathogenesis that is incompletely understood. By regulating RNA silencing and post-transcriptional gene expression, microRNAs participate in various biological processes and human diseases. However, the relationship between microRNAs and the progress of diabetic peripheral neuropathy still lacks a thorough exploration. Here we used microarray microRNA and mRNA expression profiling to analyze the microRNAs and mRNAs which are aberrantly expressed in dorsal root ganglia from streptozotocin-induced diabetic rats. We found that 37 microRNAs and 1357 mRNAs were differentially expressed in comparison to non-diabetic samples. Bioinformatics analysis indicated that 399 gene ontology terms and 29 Kyoto Encyclopedia of Genes and Genomes pathways were significantly enriched in diabetic rats. Additionally, a microRNA-gene network evaluation identified rno-miR-330-5p, rno-miR-17-1-3p and rno-miR-346 as important players for network regulation. Finally, quantitative real-time polymerase chain reaction analysis was used to confirm the microarray results. In conclusion, this study provides a systematic perspective of microRNA and mRNA expression in dorsal root ganglia from diabetic rats, and suggests that dysregulated microRNAs and mRNAs may be important promotors of peripheral neuropathy. Our results may be the underlying framework of future studies regarding the effect of the aberrantly expressed genes on the pathophysiology of diabetic peripheral neuropathy.
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Affiliation(s)
- Guojun Guo
- Department of Hand Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yutian Liu
- Department of Hand Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sen Ren
- Department of Hand Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Kang
- Department of Hand Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Dominik Duscher
- Department of Plastic and Hand Surgery, Technical University of Munich, Munich, Germany
| | - Hans-Günther Machens
- Department of Plastic and Hand Surgery, Technical University of Munich, Munich, Germany
| | - Zhenbing Chen
- Department of Hand Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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An S, Zhou M, Li Z, Feng M, Cao G, Lu S, Liu L. Administration of CoCl 2 Improves Functional Recovery in a Rat Model of Sciatic Nerve Transection Injury. Int J Med Sci 2018; 15:1423-1432. [PMID: 30443161 PMCID: PMC6216053 DOI: 10.7150/ijms.27867] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/29/2018] [Indexed: 12/28/2022] Open
Abstract
Peripheral nerve injury is known to activate the hypoxia-inducible factor-1α (HIF-1α) pathway as one of pro-regenerative transcriptional programs, which could stimulate multiple injury-induced gene expression and contribute to axon regeneration and functional recovery. However, the role of HIF-1α in peripheral nerve regeneration remains to be fully elucidated. In this study, rats were divided into three groups and treated with sham surgery, surgery with cobalt chloride (CoCl2) and surgery with saline, respectively. Sciatic functional index, morphologic evaluations of muscle fibers, and never conduction velocity were performed to measure the functional recovery at 12 weeks postoperatively. In addition, the effects of CoCl2 on the expression of HIF-1α, glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were determined at mRNA levels; as well as HIF-1α, the dual leucine zipper kinase (DLK), the c-Jun N-terminal kinase (JNK), phosphorylated JNK (p-JNK), BDNF and NGF were measured at protein level at 4 weeks postoperatively. Systemic administration of CoCl2 (15 mg/kg/day intraperitoneally) significantly promoted functional recovery of rats with sciatic nerve transection injury. This study demonstrated in rats treated with CoCl2, the expression of HIF-1α, GDNF, BDNF and NGF was significantly increased at mRNA level, while HIF-1α, DLK, p-JNK, BDNF and NGF was significantly increased at protein level.
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Affiliation(s)
- Shuai An
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University
| | - Meng Zhou
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University
| | - Zheng Li
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University
| | - Mingli Feng
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University
| | - Guanglei Cao
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University
| | - Shibao Lu
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University
| | - Limin Liu
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University
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11
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Comparison of the Hydroxylase Inhibitor Dimethyloxalylglycine and the Iron Chelator Deferoxamine in Diabetic and Aged Wound Healing. Plast Reconstr Surg 2017; 139:695e-706e. [PMID: 28234841 DOI: 10.1097/prs.0000000000003072] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND A hallmark of diabetes mellitus is the breakdown of almost every reparative process in the human body, leading to critical impairments of wound healing. Stabilization and activity of the transcription factor hypoxia-inducible factor (HIF)-1α is impaired in diabetes, leading to deficits in new blood vessel formation in response to injury. In this article, the authors compare the effectiveness of two promising small-molecule therapeutics, the hydroxylase inhibitor dimethyloxalylglycine and the iron chelator deferoxamine, for attenuating diabetes-associated deficits in cutaneous wound healing by enhancing HIF-1α activation. METHODS HIF-1α stabilization, phosphorylation, and transactivation were measured in murine fibroblasts cultured under normoxic or hypoxic and low-glucose or high-glucose conditions following treatment with deferoxamine or dimethyloxalylglycine. In addition, diabetic wound healing and neovascularization were evaluated in db/db mice treated with topical solutions of either deferoxamine or dimethyloxalylglycine, and the efficacy of these molecules was also compared in aged mice. RESULTS The authors show that deferoxamine stabilizes HIF-1α expression and improves HIF-1α transactivity in hypoxic and hyperglycemic states in vitro, whereas the effects of dimethyloxalylglycine are significantly blunted under hyperglycemic hypoxic conditions. In vivo, both dimethyloxalylglycine and deferoxamine enhance wound healing and vascularity in aged mice, but only deferoxamine universally augmented wound healing and neovascularization in the setting of both advanced age and diabetes. CONCLUSION This first direct comparison of deferoxamine and dimethyloxalylglycine in the treatment of impaired wound healing suggests significant therapeutic potential for topical deferoxamine treatment in ischemic and diabetic disease.
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12
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Ramalho AR, Toscano A, Pereira P, Girão H, Gonçalves L, Marques C. Hyperglycemia-induced degradation of HIF-1α contributes to impaired response of cardiomyocytes to hypoxia. Rev Port Cardiol 2017; 36:367-373. [PMID: 28479269 DOI: 10.1016/j.repc.2016.09.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 09/02/2016] [Accepted: 09/12/2016] [Indexed: 12/30/2022] Open
Abstract
INTRODUCTION AND OBJECTIVES Cardiovascular disease is the leading cause of mortality and morbidity associated with diabetes. Although impairment of the cell response to hypoxia due to destabilization of the transcription factor hypoxia-inducible factor-1α (HIF-1α), which regulates the expression of genes that help cells to cope with low oxygen tension, has been implicated in diabetes-associated disease, the molecular mechanisms involved remain elusive. It is known that hyperglycemia leads to the enhanced production of methylglyoxal (MGO). Therefore, the main objective of this study was to establish whether MGO leads to the degradation of HIF-1α in cardiomyocytes subjected to hypoxia. METHODS The mouse atrial cardiomyocyte cell line, HL-1, was exposed to chemical hypoxia with CoCl2 in the absence or presence of MGO. Cell viability was assessed by MTT assay, and levels of HIF-1α and endogenous ubiquitin conjugates were determined by western blotting. Proteasome activity was analyzed using a specific chymotrypsin-like fluorogenic substrate. RESULTS The results obtained indicate that MGO induces time- and dose-dependent degradation of HIF-1α accumulated under hypoxia. Additionally, we show that accumulation of endogenous ubiquitin conjugates in the presence of MGO is associated with decreased proteasome activity. CONCLUSION Taken together, the results obtained in this study suggest that MGO compromises the ability of cells to adapt to low oxygen tensions, by stimulating the degradation of HIF-1α, likely contributing to the development of diabetes-associated cardiac dysfunction.
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Affiliation(s)
- Ana Rita Ramalho
- Coimbra Hospital and University Center - Cardiology Department, Coimbra, Portugal
| | - Adriana Toscano
- CNC.IBILI, Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Paulo Pereira
- CNC.IBILI, Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Henrique Girão
- CNC.IBILI, Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Lino Gonçalves
- Coimbra Hospital and University Center - Cardiology Department, Coimbra, Portugal
| | - Carla Marques
- CNC.IBILI, Institute of Biomedical Imaging and Life Sciences (IBILI), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.
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Ramalho AR, Toscano A, Pereira P, Girão H, Gonçalves L, Marques C. Hyperglycemia-induced degradation of HIF-1α contributes to impaired response of cardiomyocytes to hypoxia. REVISTA PORTUGUESA DE CARDIOLOGIA (ENGLISH EDITION) 2017. [DOI: 10.1016/j.repce.2016.09.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Role of Hypoxia Inducible Factor 1 in Hyperglycemia-Exacerbated Blood-Brain Barrier Disruption in Ischemic Stroke. Neurobiol Dis 2016; 95:82-92. [PMID: 27425889 DOI: 10.1016/j.nbd.2016.07.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 06/16/2016] [Accepted: 07/13/2016] [Indexed: 12/18/2022] Open
Abstract
Diabetes is a major stroke risk factor and is associated with poor functional recovery after stroke. Accumulating evidence indicates that the worsened outcomes may be due to hyperglycemia-induced cerebral vascular complications, especially disruption of the blood-brain barrier (BBB). The present study tested a hypothesis that the activation of hypoxia inducible factor-1 (HIF-1) was involved in hyperglycemia-aggravated BBB disruption in an ischemic stroke model. Non-diabetic control and Streptozotocin-induced type I diabetic mice were subjected to 90min transient middle cerebral artery occlusion (MCAO) followed by reperfusion. Our results demonstrated that hyperglycemia induced higher expression of HIF-1α and vascular endothelial growth factor (VEGF) in brain microvessels after MCAO/reperfusion. Diabetic mice showed exacerbated BBB damage and tight junction disruption, increased infarct volume as well as worsened neurological deficits. Furthermore, suppressing HIF-1 activity by specific knock-out endothelial HIF-1α ameliorated BBB leakage and brain infarction in diabetic animals. Moreover, glycemic control by insulin abolished HIF-1α up-regulation in diabetic animals and reduced BBB permeability and brain infarction. These findings strongly indicate that HIF-1 plays an important role in hyperglycemia-induced exacerbation of BBB disruption in ischemic stroke. Endothelial HIF-1 inhibition warrants further investigation as a therapeutic target for the treatment of stroke patients with diabetes.
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Peng J, Hui K, Hao C, Peng Z, Gao QX, Jin Q, Lei G, Min J, Qi Z, Bo C, Dong QN, Bing ZH, Jia XY, Fu DL. Low bone turnover and reduced angiogenesis in streptozotocin-induced osteoporotic mice. Connect Tissue Res 2016; 57:277-89. [PMID: 27028715 DOI: 10.3109/03008207.2016.1171858] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
It is known that type 1 diabetes (T1D) reduces bone mass and increases the risk for fragility fractures, an effect that has been largely ascribed to decreased bone formation. However, the potential role of decreased angiogenesis as a factor in osteogenesis reduction has not been extensively studied. Furthermore, there is controversy surrounding the effect of T1D on bone resorption. This study characterized bone microstructure, bone strength, and bone turnover of streptozotocin (STZ)-induced diabetic mice (T1D mice) and explored the role of angiogenesis in the pathogenesis of T1D-induced osteoporosis. Results demonstrate that T1D deteriorated trabecular microarchitecture and led to reduced bone strength. Furthermore, T1D mice showed reduced osteoblast number/bone surface (N.Ob/BS), mineral apposition rate, mineral surface/BS, and bone formation rate/BS, suggesting attenuated bone formation. Decreased angiogenesis was shown by a reduced number of blood vessels in the femur and decreased expression of platelet endothelial cell adhesion molecule (CD31), nerve growth factor, hypoxia-inducible factor-1α, and vascular endothelial growth factor was observed. On the other hand, reduced bone resorption, an effect that could lead to impaired osteogenesis, was demonstrated by lower osteoclast number/BS and decreased tartrate-resistant acid phosphatase and cathepsin K mRNA levels. Reduced number of osteoblasts and decreased expression of receptor activator for nuclear factor-κB ligand could be responsible for compromised bone resorption in T1D mice. In conclusion, T1D mice display reduced bone formation and bone resorption, suggesting decreased bone turnover. Furthermore, this study points to impairments in angiogenesis as a pivotal cause of decreased bone formation.
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Affiliation(s)
- Jia Peng
- a Department of Orthopaedics , The Second Affiliated Hospital of Soochow University , Suzhou , Jiangsu Province , China.,b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Kang Hui
- b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Chen Hao
- b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Zhao Peng
- c Intensive Care Unit , The Second Affiliated Hospital of Soochow University , Suzhou , Jiangsu Province , China
| | - Qian Xing Gao
- d Department of Rehabilitation, 359th Hospital of Chinese People's Liberation Army , Zhen Jiang , Jiangsu Province , China
| | - Qi Jin
- b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Guo Lei
- b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Jiang Min
- b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Zhou Qi
- b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Chen Bo
- b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Qian Nian Dong
- b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Zhou Han Bing
- b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Xu You Jia
- a Department of Orthopaedics , The Second Affiliated Hospital of Soochow University , Suzhou , Jiangsu Province , China
| | - Deng Lian Fu
- b Shanghai Institute of Traumatology and Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases with Integrated Chinese-Western Medicine, Ruijin Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
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16
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Preventive Effects of the Chinese Herbal Medicine Prescription Tangkuei Decoction for Frigid Extremities on Sciatic Neuropathy in Streptozotocin-Induced Diabetic Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2016; 2016:9138328. [PMID: 27057201 PMCID: PMC4789444 DOI: 10.1155/2016/9138328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 01/24/2016] [Accepted: 02/01/2016] [Indexed: 11/18/2022]
Abstract
Ischemia and hypoxia are important physiological changes in diabetic peripheral neuropathy (DPN). Chinese herbal medicine prescription Tangkuei Decoction for Frigid Extremities (TDFE) is useful for increasing blood flow. To help determine whether TDFE could protect the peripheral nerves of diabetic patients from the degeneration caused by high blood glucose, TDFE was administered to streptozotocin-induced diabetic rats for 6 or 12 weeks. Plantar thermal stimulation reaction time thresholds, sciatic nerve conduction velocities, and the levels of HIF-1α mRNA, HIF-1α protein, VEGF protein, and the endothelial marker vWF in sciatic nerves were measured at the end of the sixth and twelfth weeks. The thermal thresholds and sciatic nerve conduction velocities of the rats differed after 12 weeks, and the sciatic nerves of the diabetic rats that were given TDFE displayed higher levels of HIF-1α protein, VEGF protein, and HIF-1α mRNA than those of the diabetic model rats. The results at 6 weeks differed from those at 12 weeks. These results suggest that the early preventive application of TDFE effectively delayed the development of DPN and that TDFE increased HIF-1α mRNA levels in the sciatic nerves of diabetic rats through 12 weeks of treatment.
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Downs CA, Faulkner MS. Toxic stress, inflammation and symptomatology of chronic complications in diabetes. World J Diabetes 2015; 6:554-565. [PMID: 25987953 PMCID: PMC4434076 DOI: 10.4239/wjd.v6.i4.554] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 12/30/2014] [Accepted: 02/12/2015] [Indexed: 02/05/2023] Open
Abstract
Diabetes affects at least 382 million people worldwide and the incidence is expected to reach 592 million by 2035. The incidence of diabetes in youth is skyrocketing as evidenced by a 21% increase in type 1 diabetes and a 30.5% increase in type 2 diabetes in the United States between 2001 and 2009. The effects of toxic stress, the culmination of biological and environmental interactions, on the development of diabetes complications is gaining attention. Stress impacts the hypothalamus-pituitary-adrenal axis and contributes to inflammation, a key biological contributor to the pathogenesis of diabetes and its associated complications. This review provides an overview of common diabetic complications such as neuropathy, cognitive decline, depression, nephropathy and cardiovascular disease. The review also provides a discussion of the role of inflammation and stress in the development and progression of chronic complications of diabetes, associated symptomatology and importance of early identification of symptoms of depression, fatigue, exercise intolerance and pain.
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18
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Wang F, Stefano GB, Kream RM. Epigenetic modification of DRG neuronal gene expression subsequent to nerve injury: etiological contribution to complex regional pain syndromes (Part II). Med Sci Monit 2014; 20:1188-200. [PMID: 25027291 PMCID: PMC4106931 DOI: 10.12659/msm.890707] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Cumulating evidence indicated that nerve injury-associated cellular and molecular changes play an essential role in contributing to the development of pathological pain, and more recent findings implicated the critical role of epigenetic mechanisms in pain-related sensitization in the DRG subsequent to nerve injury. In this part of the dyad review (Part II), we reviewed and paid special attention on the etiological contribution of DGR gene expression modulated by epigenetic mechanisms of CRPS. As essential effectors to different molecular activation, we first discussed the activation of various signaling pathways that subsequently from nerve injury, and in further illustrated the fundamental and functional underpinnings of nerve injury-induced pain, in which we argued for the potential epigenetic mechanisms in response to sensitizing stimuli or injury. Therefore, understanding the specific mediating factors that influence individual epigenetic differences contributing to pain sensitivity and responsiveness to analgesics possesses crucial clinical implications.
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Affiliation(s)
- Fuzhou Wang
- Department of Anesthesiology and Critical Care Medicine, Affiliated Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing, China (mainland)
| | - George B Stefano
- Neuroscience Research Institute, State University of New York at Old Westbury, Old Westbury, China (mainland)
| | - Richard M Kream
- Neuroscience Research Institute, State University of New York at Old Westbury, Old Westbury, China (mainland)
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Zhou J, Zhou S. Inflammation: therapeutic targets for diabetic neuropathy. Mol Neurobiol 2013; 49:536-46. [PMID: 23990376 DOI: 10.1007/s12035-013-8537-0] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 08/15/2013] [Indexed: 11/26/2022]
Abstract
There are still no approved treatments for the prevention or of cure of diabetic neuropathy, and only symptomatic pain therapies of variable efficacy are available. Inflammation is a cardinal pathogenic mechanism of diabetic neuropathy. The relationships between inflammation and the development of diabetic neuropathy involve complex molecular networks and processes. Herein, we review the key inflammatory molecules (inflammatory cytokines, adhesion molecules, chemokines) and pathways (nuclear factor kappa B, JUN N-terminal kinase) implicated in the development and progression of diabetic neuropathy. Advances in the understanding of the roles of these key inflammatory molecules and pathways in diabetic neuropathy will facilitate the discovery of the potential of anti-inflammatory approaches for the inhibition of the development of neuropathy. Specifically, many anti-inflammatory drugs significantly inhibit the development of different aspects of diabetic neuropathy in animal models and clinical trials.
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Affiliation(s)
- Jiyin Zhou
- National Drug Clinical Trial Institution, Xinqiao Hospital, Third Military Medical University, Chongqing, 400037, China,
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Yan J, Zhang Z, Shi H. HIF-1 is involved in high glucose-induced paracellular permeability of brain endothelial cells. Cell Mol Life Sci 2012; 69:115-28. [PMID: 21617913 PMCID: PMC11115066 DOI: 10.1007/s00018-011-0731-5] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 04/22/2011] [Accepted: 05/09/2011] [Indexed: 01/04/2023]
Abstract
Experimental evidence from human patients and animal models of diabetes has demonstrated that hyperglycemia increases blood-brain barrier (BBB) permeability, which is associated with increased risk of neurological dysfunction. However, the mechanism underlying high glucose-induced BBB disruption is not understood. Here we investigated the role of hypoxia-inducible factor-1 (HIF-1) in high glucose-induced endothelial permeability in vitro using mouse brain microvascular endothelial cells (b.End3). Our results demonstrated that high glucose (30 mM) upregulated the protein level of HIF-1α, the regulatable subunit of HIF-1, and increased the transcriptional activity of HIF-1 in the endothelial cells. At the same time, high glucose increased the paracellular permeability associated with diminished expression and disrupted continuity of tight junction proteins occludin and zona occludens protein-1 (ZO-1) of the endothelial cells. Upregulating HIF-1 activity by cobalt chloride increased the paracellular permeability of the endothelial cells exposed to normal glucose (5.5 mM). In contrast, downregulating HIF-1 activity by HIF-1α inhibitors and HIF-1α specific siRNA ameliorated the increased paracellular permeability and the alterations of distribution pattern of occludin and ZO-1 induced by high glucose. In addition, high glucose increased expression of vascular endothelial growth factor (VEGF), a downstream gene of HIF-1. Inhibiting VEGF improved the expression pattern of occludin and ZO-1, and attenuated the endothelial leakage. Furthermore, key results were confirmed in human brain microvascular endothelial cells. These results strongly indicate that HIF-1 plays an important role in high glucose-induced BBB dysfunction. The results will help us understand the molecular mechanisms involved in hyperglycemia-induced BBB dysfunction and neurological outcomes.
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Affiliation(s)
- Jingqi Yan
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, 1251 Wescoe Hall Drive, Malott Hall 5044, Lawrence, KS 66045 USA
| | - Ziyan Zhang
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, 1251 Wescoe Hall Drive, Malott Hall 5044, Lawrence, KS 66045 USA
| | - Honglian Shi
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, 1251 Wescoe Hall Drive, Malott Hall 5044, Lawrence, KS 66045 USA
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Ochiai D, Goda N, Hishiki T, Kanai M, Senoo-Matsuda N, Soga T, Johnson RS, Yoshimura Y, Suematsu M. Disruption of HIF-1α in hepatocytes impairs glucose metabolism in diet-induced obesity mice. Biochem Biophys Res Commun 2011; 415:445-9. [PMID: 22051049 DOI: 10.1016/j.bbrc.2011.10.089] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 10/18/2011] [Indexed: 11/16/2022]
Abstract
The liver plays a central role in glucose homeostasis in the whole-body by responding to environmental factors including nutrients, hormones, and oxygen. In conditions of metabolic overload such as diabetes mellitus and obesity, coordinated regulation between oxygen supply and consumption has been reported to be disrupted and subsequently cause tissue hypoxia, although pathological significance of the disease-related hypoxia remains elusive. To investigate the role of tissue hypoxia in the liver on systemic glucose homeostasis, mice lacking HIF-1α gene, a critical component of a master regulator of hypoxic response, in hepatocytes were exposed to high fat/sucrose diet (HFSD). Exposure to HFSD for 5 weeks elicited liver hypoxia with a transient increase in HIF-1α protein expression in the liver of control mice. Glucose disposal was marginally impaired in control mice when challenged oral glucose tolerance test, but such impairment was enhanced in the mutant mice. This alteration was accompanied by a complete inhibition of glucokinase induction with a significant reduction of hepatic glucose uptake. Mice fed HFSD for 20 weeks exhibited fasting hyperglycemia and glucose intolerance, whereas these metabolic phenotypes deteriorated considerably with severe insulin resistance in skeletal muscles and adipose tissues in the mutant mice. These findings suggest that HIF-1 in hepatocytes plays protective roles against the progression of diabetes mellitus.
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Affiliation(s)
- Daigo Ochiai
- Department of Obstetrics & Gynecology, School of Medicine, Keio University, Japan
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Wang Y, Tang Z, Xue R, Singh GK, Shi K, Lv Y, Yang L. Combined effects of TNF-α, IL-1β, and HIF-1α on MMP-2 production in ACL fibroblasts under mechanical stretch: an in vitro study. J Orthop Res 2011; 29:1008-14. [PMID: 21344498 DOI: 10.1002/jor.21349] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 12/09/2010] [Indexed: 02/04/2023]
Abstract
The dynamics between inflammatory factors, mechanical stress, and healing factors, in an intra-articular joint, are very complex after injury. Injury to intra-articular tissue [anterior cruciate ligament (ACL), synovium] results in hypoxia, accumulation of various pro-inflammatory factors, cytokines, and metalloproteases. Although the presence of increased amounts of matrix-metalloproteinases (MMP) in the joint fluid after knee injury is considered the key factor for ACL poor healing ability; however, the exact role of collective participants of the joint fluid on MMP-2 activity and production has not been fully studied yet. To investigate the combined effects of mechanical injury, inflammation and hypoxia induced factor-1α (HIF-1α) on induction of MMP-2; we mimicked the microenvironment of joint cavity after ACL injury. The results show that TNF-α and IL-1β elevate the activity of MMP-2 in a dose- and time-dependent manner. In addition, mechanical stretch further enhances the MMP-2 protein levels with TNF-α, IL-1β, and their mixture. CoCl(2) -induced HIF-1α (100 and 500 µM) also increases the levels and activity of MMP-2. Mechanical stretch has a strong additional effect on MMP-2 production with HIF-1α. Our results conclude that mechanical injury, HIF-1α and inflammatory factors collectively induce increased MMP-2 production in ACL fibroblasts, which was inhibited by NF-κB pathway inhibitor (Bay-11-7082).
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Affiliation(s)
- Yequan Wang
- Key Laboratory of Biorheological Science and Technology (Chongqing University), Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044, PR China
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Lin M, Chen Y, Jin J, Hu Y, Zhou KK, Zhu M, Le YZ, Ge J, Johnson RS, Ma JX. Ischaemia-induced retinal neovascularisation and diabetic retinopathy in mice with conditional knockout of hypoxia-inducible factor-1 in retinal Müller cells. Diabetologia 2011; 54:1554-66. [PMID: 21360191 PMCID: PMC6592825 DOI: 10.1007/s00125-011-2081-0] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Accepted: 01/19/2011] [Indexed: 12/22/2022]
Abstract
AIMS/HYPOTHESIS Retinal Müller cells are known to produce inflammatory and angiogenic cytokines, which play important roles in diabetic retinopathy. Hypoxia-inducible factor (HIF)-1 has been shown to play a crucial role in retinal inflammation and neovascularisation. We sought to determine the role of Müller cell-derived HIF-1 in oxygen-induced retinopathy (OIR) and diabetic retinopathy using conditional Hif-1α (also known as Hif1a) knockout (KO) mice. METHODS Conditional Hif-1α KO mice were generated by crossing mice expressing cyclisation recombinase (cre, also known as P1_gp003) in Müller cells with floxed Hif-1α mice and used for OIR and streptozotocin-induced diabetes to induce retinal neovascularisation and inflammation, respectively. Abundance of HIF-1α and pro-angiogenic and pro-inflammatory factors was measured by immunoblotting and immunohistochemistry. Retinal neovascularisation was visualised by angiography and quantified by counting pre-retinal nuclei. Retinal inflammation was evaluated by leucostasis and vascular leakage. RESULTS While the Hif-1α KO mice showed significantly decreased HIF-1α levels in the retina, they exhibited no apparent histological or visual functional abnormalities under normal conditions. Compared with wild-type counterparts, Hif-1α KO mice with OIR demonstrated attenuated overproduction of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule (ICAM)-1, reduced vascular leakage and alleviated neovascularisation in the retina. Under diabetes conditions, disruption of Hif-1α in Müller cells attenuated the increases of retinal vascular leakage and adherent leucocytes, as well as the overproduction of VEGF and ICAM-1. CONCLUSIONS/INTERPRETATION Müller cell-derived HIF-1α is a key mediator of retinal neovascularisation, vascular leakage and inflammation, the major pathological changes in diabetic retinopathy. Müller cell-derived HIF-1α is therefore a promising therapeutic target for diabetic retinopathy.
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Affiliation(s)
- M Lin
- Department of Physiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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Hypoxia-induced sensitization of transient receptor potential vanilloid 1 involves activation of hypoxia-inducible factor-1 alpha and PKC. Pain 2011; 152:936-945. [DOI: 10.1016/j.pain.2011.02.024] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 12/26/2010] [Accepted: 02/07/2011] [Indexed: 02/01/2023]
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de Preux Charles AS, Verdier V, Zenker J, Peter B, Médard JJ, Kuntzer T, Beckmann JS, Bergmann S, Chrast R. Global transcriptional programs in peripheral nerve endoneurium and DRG are resistant to the onset of type 1 diabetic neuropathy in Ins2 mice. PLoS One 2010; 5:e10832. [PMID: 20520806 PMCID: PMC2877074 DOI: 10.1371/journal.pone.0010832] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 04/20/2010] [Indexed: 12/13/2022] Open
Abstract
While the morphological and electrophysiological changes underlying diabetic peripheral neuropathy (DPN) are relatively well described, the involved molecular mechanisms remain poorly understood. In this study, we investigated whether phenotypic changes associated with early DPN are correlated with transcriptional alterations in the neuronal (dorsal root ganglia [DRG]) or the glial (endoneurium) compartments of the peripheral nerve. We used Ins2(Akita/+) mice to study transcriptional changes underlying the onset of DPN in type 1 diabetes mellitus (DM). Weight, blood glucose and motor nerve conduction velocity (MNCV) were measured in Ins2(Akita/+) and control mice during the first three months of life in order to determine the onset of DPN. Based on this phenotypic characterization, we performed gene expression profiling using sciatic nerve endoneurium and DRG isolated from pre-symptomatic and early symptomatic Ins2(Akita/+) mice and sex-matched littermate controls. Our phenotypic analysis of Ins2(Akita/+) mice revealed that DPN, as measured by reduced MNCV, is detectable in affected animals already one week after the onset of hyperglycemia. Surprisingly, the onset of DPN was not associated with any major persistent changes in gene expression profiles in either sciatic nerve endoneurium or DRG. Our data thus demonstrated that the transcriptional programs in both endoneurial and neuronal compartments of the peripheral nerve are relatively resistant to the onset of hyperglycemia and hypoinsulinemia suggesting that either minor transcriptional alterations or changes on the proteomic level are responsible for the functional deficits associated with the onset of DPN in type 1 DM.
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Avogaro A, Fadini GP. Role of endothelial progenitor cells in diabetes mellitus. Expert Rev Endocrinol Metab 2009; 4:575-589. [PMID: 30780783 DOI: 10.1586/eem.09.49] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Endothelial progenitor cells (EPCs) are bone marrow-derived cells involved in endothelial healing and angiogenesis. EPCs are considered an integrated component of the cardiovascular system, which promotes vascular health. Derangement of EPC biology in diabetes has been hailed as a novel concept in the pathogenesis of micro- and macro-vascular complications. Additionally, EPCs are considered to be disease biomarkers, as they provide an index of cardiovascular risk. The mechanisms leading to EPC dysfunction in diabetes may include defective mobilization from bone marrow to peripheral blood and reduced half-life. Hyperglycemia is considered the major determinant of microvascular complications, while other mechanisms concur to increase the risk of cardiovascular disease in diabetic patients. EPCs may represent a novel pathophysiological connection to understand development and progression of diabetic complications.
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Affiliation(s)
- Angelo Avogaro
- a Dipartimento di Medicina Clinica e Sperimentale, Cattedra di Malattie del Metabolismo, Università di Padova, Via Giustiniani 2, 35128 Padova, Italy.
| | - Gian Paolo Fadini
- b Dipartimento di Medicina clinica e Sperimentale, Cattedra di Malattie del Metabolismo, Università di Padova, Via Giustiniani 2, 35128 Padova, Italy.
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Zhu X, Zhou W, Cui Y, Zhu L, Li J, Feng X, Shao B, Qi H, Zheng J, Wang H, Chen H. Pilocarpine protects cobalt chloride-induced apoptosis of RGC-5 cells: involvement of muscarinic receptors and HIF-1 alpha pathway. Cell Mol Neurobiol 2009; 30:427-35. [PMID: 19816768 DOI: 10.1007/s10571-009-9467-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2009] [Accepted: 09/25/2009] [Indexed: 12/26/2022]
Abstract
The retina is the most metabolically active tissue in the human body and hypoxia-induced retinal ganglion cell (RGC) death has been implicated in glaucomatous optic neuropathy. The aim of this study is to determine whether muscarinic receptor agonist pilocarpine, a classic antiglaucoma drug, possesses neuroprotection against cobalt chloride (CoCl(2))-mimetic hypoxia-induced apoptosis of rat retinal ganglion cells (RGC-5 cells) and its underlying mechanisms. Cell viability was determined by Cell Counting Kit-8 assay and apoptosis was examined by annexin V and mitochondrial membrane potential (MMP) assays. Expressions of hypoxia-induced factor-1 alpha (HIF-1 alpha), p53, and BNIP3 were investigated by quantitative real-time PCR and western blot analysis. After treatment of 200 microM CoCl(2) for 24 h, RGC-5 cells showed a marked decrease of cell viability by approximately 30%, increased apoptosis rate and obvious decline in MMP, which could largely be reversed by the pretreatment of 1 microM pilocarpine mainly via the activation of muscarinic receptors. Meanwhile, pretreatment of 1 microM pilocarpine could significantly prevent CoCl(2)-induced HIF-1 alpha translocation from cytoplasm to nucleus and down-regulate the expression of HIF-1 alpha, p53, and BNIP3. These studies demonstrated that pilocarpine had effective protection against hypoxia-induced apoptosis in RGCs via muscarinic receptors and HIF-1 alpha pathway. The findings suggest that HIF-1 alpha pathway as a "master switch" may be used as a therapeutic target in the cholinergic treatment of glaucoma.
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Affiliation(s)
- Xu Zhu
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China
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Quattrini C, Jeziorska M, Boulton AJM, Malik RA. Reduced vascular endothelial growth factor expression and intra-epidermal nerve fiber loss in human diabetic neuropathy. Diabetes Care 2008; 31:140-5. [PMID: 17934147 DOI: 10.2337/dc07-1556] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To assess the relevance of vascular endothelial growth factor (VEGF) in the maintenance of peripheral nerve integrity in diabetic neuropathy we have assessed the expression of VEGF and intra-epidermal nerve fiber density (IENFD) in skin biopsy samples from diabetic patients. RESEARCH DESIGN AND METHODS Fifty-three diabetic patients and 12 nondiabetic control subjects underwent neurological evaluation, electrophysiology, quantitative sensory, and autonomic function testing. Dermal blood flow responses were evaluated with laser Doppler flowmetry. Skin biopsies were performed on the dorsum of the foot, and IENFD was quantified and compared with the expression of vascular endothelial growth factor A (VEGF-A), its receptor vascular endothelial growth factor receptor 2 (VEGFR-2), hypoxia-inducible factor 1alpha (HIF-1alpha), and microvessel density. RESULTS IENFD decreased progressively with increasing severity of diabetic neuropathy (P < 0.001). The dermal blood flow response to acetylcholine was reduced in diabetic patients with mild and moderate neuropathy (P < 0.01), and the intensity of staining for epidermal VEGF-A was significantly reduced in diabetic patients compared with control subjects (P < 0.01). Epidermal HIF-1alpha and VEGFR-2 expression did not differ between groups. CONCLUSIONS Progressive endothelial dysfunction, a reduction in VEGF expression, and loss of intra-epidermal nerve fibers occurs in the foot skin of diabetic patients with increasing neuropathic severity.
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Affiliation(s)
- Cristian Quattrini
- Division of Cardiovascular Medicine, University of Manchester and Manchester Diabetes Centre, Manchester Royal Infirmary, Manchester, UK
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Oka N, Kawasaki T, Mizutani K, Sugiyama H, Akiguchi I. Hypoxia-inducible factor 1α may be a marker for vasculitic neuropathy. Neuropathology 2007; 27:509-15. [DOI: 10.1111/j.1440-1789.2007.00817.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Fadini GP, Sartore S, Agostini C, Avogaro A. Significance of endothelial progenitor cells in subjects with diabetes. Diabetes Care 2007; 30:1305-13. [PMID: 17277037 DOI: 10.2337/dc06-2305] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Gian Paolo Fadini
- Department of Clinical and Experimental Medicine, University of Padova Medical School, Padova, Italy.
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31
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Jagodic MM, Pathirathna S, Nelson MT, Mancuso S, Joksovic PM, Rosenberg ER, Bayliss DA, Jevtovic-Todorovic V, Todorovic SM. Cell-specific alterations of T-type calcium current in painful diabetic neuropathy enhance excitability of sensory neurons. J Neurosci 2007; 27:3305-16. [PMID: 17376991 PMCID: PMC6672477 DOI: 10.1523/jneurosci.4866-06.2007] [Citation(s) in RCA: 210] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recent data indicate that T-type Ca2+ channels are amplifiers of peripheral pain signals, but their involvement in disorders of sensory neurons such as those associated with diabetes is poorly understood. To address this issue, we used a combination of behavioral, immunohistological, molecular, and electrophysiological studies in rats with streptozotocin (N-[methylnitrosocarbamoil]-D-glucosamine)-induced early diabetic neuropathy. We found that, in parallel with the development of diabetes-induced pain, T-type current density increased by twofold in medium-size cells from L4-L5 dorsal root ganglia (DRG) with a depolarizing shift in steady-state inactivation. This not only correlated closely with more prominent afterdepolarizing potentials (ADPs) but also increased cellular excitability manifested as a lower threshold for burst firing in diabetic than in control cells. T-type currents and ADPs were potently inhibited by nickel and enhanced by L-cysteine, suggesting that the Ca(V)3.2 T-type channel isoform was upregulated. Both control and diabetic DRG cells with ADPs stained positively for isolectin B4, but only diabetic cells responded robustly to capsaicin, suggesting enhanced nociceptive function. Because increased excitability of sensory neurons may result in such pathological perceptions of pain as hyperalgesia and allodynia, upregulation of T-type Ca2+ currents and enhanced Ca2+ entry into these cells could contribute to the development of symptoms in diabetic neuropathy.
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Affiliation(s)
| | | | - Michael T. Nelson
- Departments of Anesthesiology
- Neuroscience Graduate Program, University of Virginia Health System, Charlottesville, Virginia 22908
| | | | | | | | - Douglas A. Bayliss
- Departments of Anesthesiology
- Pharmacology and
- Neuroscience Graduate Program, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Vesna Jevtovic-Todorovic
- Departments of Anesthesiology
- Neuroscience, and
- Neuroscience Graduate Program, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Slobodan M. Todorovic
- Departments of Anesthesiology
- Neuroscience, and
- Neuroscience Graduate Program, University of Virginia Health System, Charlottesville, Virginia 22908
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Abu El-Asrar AM, Missotten L, Geboes K. Expression of hypoxia-inducible factor-1alpha and the protein products of its target genes in diabetic fibrovascular epiretinal membranes. Br J Ophthalmol 2007; 91:822-6. [PMID: 17229797 PMCID: PMC1955571 DOI: 10.1136/bjo.2006.109876] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
AIMS To investigate the expression of the hypoxia-inducible factor-1alpha (HIF-1alpha) and the protein products of its target genes vascular endothelial growth factor (VEGF), erythropoietin (Epo) and angiopoietins (Angs), and the antiangiogenic pigment epithelium-derived factor (PEDF) in proliferative diabetic retinopathy (PDR) epiretinal membranes. METHODS Sixteen membranes were studied by immunohistochemical techniques. RESULTS Vascular endothelial cells expressed HIF-1alpha, Ang-2 and VEGF in 15 (93.75%), 6 (37.5%) and 9 (56.25%) membranes, respectively. There was no immunoreactivity for Epo, Ang-1 and PEDF. There were significant correlations between the number of blood vessels expressing the panendothelial marker CD34 and the numbers of blood vessels expressing HIF-1alpha (r = 0.554; p = 0.026), Ang-2 (r = 0.830; p<0.001) and VEGF (r = 0.743; p = 0.001). The numbers of blood vessels expressing Ang-2 and VEGF in active membranes were higher than that in inactive membranes (p = 0.015 and 0.028, respectively). CONCLUSIONS HIF-1alpha, Ang-2 and VEGF may play an important role in the pathogenesis of PDR. The findings suggest an adverse angiogenic milieu in PDR epiretinal membranes favouring aberrant neovascularisation and endothelial abnormalities.
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Affiliation(s)
- Ahmed M Abu El-Asrar
- Department of Ophthalmology, King Abdulaziz University Hospital, Airport Road, PO Box 245, Riyadh 11411, Saudi Arabia.
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Cipriani P, Franca Milia A, Liakouli V, Pacini A, Manetti M, Marrelli A, Toscano A, Pingiotti E, Fulminis A, Guiducci S, Perricone R, Kahaleh B, Matucci-Cerinic M, Ibba-Manneschi L, Giacomelli R. Differential expression of stromal cell-derived factor 1 and its receptor CXCR4 in the skin and endothelial cells of systemic sclerosis patients: Pathogenetic implications. ACTA ACUST UNITED AC 2006; 54:3022-33. [PMID: 16948134 DOI: 10.1002/art.22047] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Systemic sclerosis (SSc) is characterized by early endothelial damage evolving to vascular desertification. Stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4 regulate specific steps in new vessel formation. We undertook this study to determine whether an alteration of the SDF-1/CXCR4 axis might be involved in the pathogenetic mechanisms following ischemic damage during SSc. METHODS We enrolled 36 SSc patients and 15 controls. Skin biopsy samples were obtained from each subject, and the expression of SDF-1 and CXCR4 was assessed by immunohistochemistry, reverse transcription-polymerase chain reaction (RT-PCR), and Western blot analyses. Furthermore, isolated microvascular endothelial cells (MVECs) from 4 patients with diffuse cutaneous SSc (dcSSc) and 3 controls were analyzed for SDF-1 and CXCR4 by confocal laser scanning microscopy, RT-PCR, and Western blotting. RESULTS SDF-1 and CXCR4 were up-regulated in the skin of patients with early (edematous) SSc, both in the diffuse and limited cutaneous forms, and progressively decreased, with the lowest expression in the latest phases of both SSc subsets. MVECs from patients with dcSSc expressed significantly higher amounts of both isoforms of SDF-1 in the early stage of disease, with a progressive reduction of SDF-1 and CXCR4 in later stages. On the surface of cultured MVECs from patients with dcSSc, SDF-1 and CXCR4 colocalized in polarized areas, suggesting that they are activated in vivo and that they are under strict genetic control to retain capping function. CONCLUSION Due to its transient expression, SDF-1 could be considered a future therapeutic target to induce new vessel formation in SSc.
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Arjamaa O, Nikinmaa M. Oxygen-dependent diseases in the retina: Role of hypoxia-inducible factors. Exp Eye Res 2006; 83:473-83. [PMID: 16750526 DOI: 10.1016/j.exer.2006.01.016] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Revised: 01/04/2006] [Accepted: 01/05/2006] [Indexed: 12/30/2022]
Abstract
The function of the retina is sensitive to oxygen tension. Any change in the perfusion pressure of the eye affects the retina although the eye is able to autoregulate its hemodynamics. Systemic hypoxemia (lung or heart disease) or a vascular disease in the retina can cause retinal hypoxia. All the hypoxia-dependent events in cells appear to share a common denominator: hypoxia-inducible factor (HIF), which is a heterodimeric transcription factor, a protein. HIF comprises a labile alpha subunit (1-3), which is regulated, and a stable beta subunit, which is constitutively expressed. Both are helix-loop-helix factors and belong to the PAS-domain family of transcription factors. Oxygen plays the key role in stabilizing HIF-1alpha and its function. When the oxygen tension is normal, HIF-1alpha is rapidly oxidized by hydroxylase enzymes, but when cells become hypoxic, HIF-1alpha escapes the degradation and starts to accumulate, triggering the activation of a large number of genes, like vascular endothelial growth factor (VEGF) and erythropoietin. HIF-1alpha has been shown to have, either clinically or experimentally, a mediating or contributing role in several oxygen-dependent retinal diseases such as von Hippel-Lindau, proliferative diabetic retinopathy, retinopathy of prematurity and glaucoma. In retinitis pigmentosa and high-altitude retinopathy, however, the evidence is still indirect. There are three different strategies available for treating retinal diseases, which have all shown promising results: retinal cell transplantation or replacement, gene replacement, and pharmacological intervention. Specifically, recent results show that the HIF pathway can be used as a therapeutic target, although there is still a long way to go from bench to clinic. HIF can be stabilized by inhibiting prolyl hydroxylase or by blocking the VHL:HIF-alpha complex if angiogenesis is the goal, as in retinitis pigmentosa. On the other hand, the downregulation of HIF has a pivotal role if we are to inhibit neovascularization, as in proliferative diabetic retinopathy. To date, several small-molecule inhibitors of HIF have been developed and are entering clinical trials. HIF is a remarkable example of a single transcription factor that can be regarded as a "master switch" regulating all the oxygen-dependent retinal diseases.
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Affiliation(s)
- Olli Arjamaa
- Laboratory of Animal Physiology, Department of Biology, Center of Excellence in Evolutionary Genetics and Physiology, 20014 University of Turku, Finland.
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Malik RA, Veves A, Tesfaye S. Ameliorating human diabetic neuropathy: Lessons from implanting hematopoietic mononuclear cells. Exp Neurol 2006; 201:7-14. [PMID: 16808913 DOI: 10.1016/j.expneurol.2006.04.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2006] [Revised: 03/24/2006] [Accepted: 04/12/2006] [Indexed: 11/24/2022]
Affiliation(s)
- R A Malik
- Division of Cardiovascular and Endocrine Sciences, University of Manchester, Manchester, UK.
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