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Pușcașu C, Negreș S, Zbârcea CE, Ungurianu A, Ștefănescu E, Blebea NM, Chiriță C. Evaluating the Antihyperalgesic Potential of Sildenafil-Metformin Combination and Its Impact on Biochemical Markers in Alloxan-Induced Diabetic Neuropathy in Rats. Pharmaceuticals (Basel) 2024; 17:783. [PMID: 38931450 PMCID: PMC11206800 DOI: 10.3390/ph17060783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 06/03/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
(1) Background: Globally, about 600 million people are afflicted with diabetes, and one of its most prevalent complications is neuropathy, a debilitating condition. At the present time, the exploration of novel therapies for alleviating diabetic-neuropathy-associated pain is genuinely captivating, considering that current therapeutic options are characterized by poor efficacy and significant risk of side effects. In the current research, we evaluated the antihyperalgesic effect the sildenafil (phosphodiesterase-5 inhibitor)-metformin (antihyperglycemic agent) combination and its impact on biochemical markers in alloxan-induced diabetic neuropathy in rats. (2) Methods: This study involved a cohort of 70 diabetic rats and 10 non-diabetic rats. Diabetic neuropathy was induced by a single dose of 130 mg/kg alloxan. The rats were submitted to thermal stimulus test using a hot-cold plate and to tactile stimulus test using von Frey filaments. Moreover, at the end of the experiment, the animals were sacrificed and their brains and livers were collected to investigate the impact of this combination on TNF-α, IL-6, nitrites and thiols levels. (3) Results: The results demonstrated that all sildenafil-metformin combinations decreased the pain sensitivity in the von Frey test, hot plate test and cold plate test. Furthermore, alterations in nitrites and thiols concentrations and pro-inflammatory cytokines (specifically TNF-α and IL-6) were noted following a 15-day regimen of various sildenafil-metformin combinations. (4) Conclusions: The combination of sildenafil and metformin has a synergistic effect on alleviating pain in alloxan-induced diabetic neuropathy rats. Additionally, the combination effectively decreased inflammation, inhibited the rise in NOS activity, and provided protection against glutathione depletion.
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Affiliation(s)
- Ciprian Pușcașu
- Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, Traian Vuia 6, 020956 Bucharest, Romania; (C.P.); (S.N.); (A.U.); (E.Ș.); (C.C.)
| | - Simona Negreș
- Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, Traian Vuia 6, 020956 Bucharest, Romania; (C.P.); (S.N.); (A.U.); (E.Ș.); (C.C.)
| | - Cristina Elena Zbârcea
- Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, Traian Vuia 6, 020956 Bucharest, Romania; (C.P.); (S.N.); (A.U.); (E.Ș.); (C.C.)
| | - Anca Ungurianu
- Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, Traian Vuia 6, 020956 Bucharest, Romania; (C.P.); (S.N.); (A.U.); (E.Ș.); (C.C.)
| | - Emil Ștefănescu
- Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, Traian Vuia 6, 020956 Bucharest, Romania; (C.P.); (S.N.); (A.U.); (E.Ș.); (C.C.)
| | - Nicoleta Mirela Blebea
- Faculty of Pharmacy, “Ovidius” University of Constanța, Căpitan Aviator Al. Şerbănescu 6, 900470 Constanța, Romania;
| | - Cornel Chiriță
- Faculty of Pharmacy, “Carol Davila” University of Medicine and Pharmacy, Traian Vuia 6, 020956 Bucharest, Romania; (C.P.); (S.N.); (A.U.); (E.Ș.); (C.C.)
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Liu Y, Zhao F, Song T, Tang M, Tian L, He T, Li D, Xiao Y, Zhang X. Nanohybrid dual-network chitosan-based hydrogels: Synthesis, characterization, quicken infected wound healing by angiogenesis and immune-microenvironment regulation. Carbohydr Polym 2024; 325:121589. [PMID: 38008479 DOI: 10.1016/j.carbpol.2023.121589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 11/10/2023] [Accepted: 11/11/2023] [Indexed: 11/28/2023]
Abstract
Infectious wounds are difficult to heal because of vascular damage and immune imbalance. The multi-functional hydrogel dressing can regulate vascular regeneration and immune microenvironment through continuous supply of bioactive ingredients to the wound site, which can effectively accelerate the healing speed of infected wounds. In this work, a multifunctional dual-network hydrogel (QCMOD) with good injectability, stability, self-healing and adhesion was designed by combining methacrylic anhydride-modified quaternized chitosan (QCM) with oxidized dextran (OD) via Schiff base reaction and photo-crosslinked polymerization. Subsequently, MgO/Icariin composite nanoparticles with icariin coating were prepared and loaded in QCMOD hydrogel to establish nanohybrid dual-network chitosan-based hydrogels (QCMOD@MI), which possessed a controlled release of Mg2+ and icariin as well as the ability of guiding physiological behavior in wound healing progress. In vitro results showed the nanohybrid hydrogel reduced bacterial infection and possessed multiple physiological functions including promoting cell migration, angiogenesis and reducing secretion of inflammatory factors. In vivo, the nanohybrid hydrogel showed excellent pro-healing abilities for infected full-thickness wounds by reducing bacterial infections and improving the microenvironment of ischemia and inflammation. This study provides a new paradigm for the design of multifunctional bioactive hydrogels and the obtained hydrogel is expected to become a new type of functional dressing.
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Affiliation(s)
- Yifan Liu
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610065, China; College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Fengxin Zhao
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610065, China; College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Tao Song
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610065, China; College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Ming Tang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610065, China; College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Luoqiang Tian
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610065, China; College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Tinghan He
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610065, China; College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Dongxiao Li
- Sichuan Academy of Chinese Medicine Science, Chengdu, Sichuan 610042, China
| | - Yumei Xiao
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610065, China; College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, China.
| | - Xingdong Zhang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, Sichuan 610065, China; College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
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Zhang ZY, Zuo ZY, Liang Y, Zhang SM, Zhang CX, Chi J, Fan B, Li GY. Promotion of axon regeneration and protection on injured retinal ganglion cells by rCXCL2. Inflamm Regen 2023; 43:31. [PMID: 37340465 DOI: 10.1186/s41232-023-00283-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 05/31/2023] [Indexed: 06/22/2023] Open
Abstract
BACKGROUND In addition to rescuing injured retinal ganglion cells (RGCs) by stimulating the intrinsic growth ability of damaged RGCs in various retinal/optic neuropathies, increasing evidence has shown that the external microenvironmental factors also play a crucial role in restoring the survival of RGCs by promoting the regrowth of RGC axons, especially inflammatory factors. In this study, we aimed to screen out the underlying inflammatory factor involved in the signaling of staurosporine (STS)-induced axon regeneration and verify its role in the protection of RGCs and the promotion of axon regrowth. METHODS We performed transcriptome RNA sequencing for STS induction models in vitro and analyzed the differentially expressed genes. After targeting the key gene, we verified the role of the candidate factor in RGC protection and promotion of axon regeneration in vivo with two RGC-injured animal models (optic nerve crush, ONC; retinal N-methyl-D-aspartate, NMDA damage) by using cholera toxin subunit B anterograde axon tracing and specific immunostaining of RGCs. RESULTS We found that a series of inflammatory genes expressed upregulated in the signaling of STS-induced axon regrowth and we targeted the candidate CXCL2 gene since the level of the chemokine CXCL2 gene elevated significantly among the top upregulated genes. We further demonstrated that intravitreal injection of rCXCL2 robustly promoted axon regeneration and significantly improved RGC survival in ONC-injured mice in vivo. However, different from its role in ONC model, the intravitreal injection of rCXCL2 was able to simply protect RGCs against NMDA-induced excitotoxicity in mouse retina and maintain the long-distance projection of RGC axons, yet failed to promote significant axon regeneration. CONCLUSIONS We provide the first in vivo evidence that CXCL2, as an inflammatory factor, is a key regulator in the axon regeneration and neuroprotection of RGCs. Our comparative study may facilitate deciphering the exact molecular mechanisms of RGC axon regeneration and developing high-potency targeted drugs.
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Affiliation(s)
- Zi-Yuan Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Zhao-Yang Zuo
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Yang Liang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Si-Ming Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Chun-Xia Zhang
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Jing Chi
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China
| | - Bin Fan
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China.
| | - Guang-Yu Li
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, 130041, China.
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Reda H. Neurologic Complications of Endocrine Disorders. Continuum (Minneap Minn) 2023; 29:887-902. [PMID: 37341334 DOI: 10.1212/con.0000000000001262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
OBJECTIVE This article provides an overview of the neurologic complications of the most prevalent endocrine disorders in adults with an emphasis on relevant neurologic symptoms, signs, and laboratory and neuroimaging findings. LATEST DEVELOPMENTS Although the mechanisms of many of the neurologic complications discussed here remain unclear, our understanding of the impacts of diabetes and hypothyroidism on the nervous system and muscle, including complications of rapid correction of chronic hyperglycemia, has advanced in recent years. Recent large studies have not demonstrated a convincing association between subclinical or overt hypothyroidism and cognitive decline. ESSENTIAL POINTS Neurologists must become familiar with the neurologic complications of endocrine disorders not only because they are common and treatable (and often reversible) but also because they may be iatrogenic, as is the case with adrenal insufficiency in the setting of long-term corticosteroid therapy.
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Zheng SY, Wan XX, Kambey PA, Luo Y, Hu XM, Liu YF, Shan JQ, Chen YW, Xiong K. Therapeutic role of growth factors in treating diabetic wound. World J Diabetes 2023; 14:364-395. [PMID: 37122434 PMCID: PMC10130901 DOI: 10.4239/wjd.v14.i4.364] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/16/2023] [Accepted: 03/21/2023] [Indexed: 04/12/2023] Open
Abstract
Wounds in diabetic patients, especially diabetic foot ulcers, are more difficult to heal compared with normal wounds and can easily deteriorate, leading to amputation. Common treatments cannot heal diabetic wounds or control their many complications. Growth factors are found to play important roles in regulating complex diabetic wound healing. Different growth factors such as transforming growth factor beta 1, insulin-like growth factor, and vascular endothelial growth factor play different roles in diabetic wound healing. This implies that a therapeutic modality modulating different growth factors to suit wound healing can significantly improve the treatment of diabetic wounds. Further, some current treatments have been shown to promote the healing of diabetic wounds by modulating specific growth factors. The purpose of this study was to discuss the role played by each growth factor in therapeutic approaches so as to stimulate further therapeutic thinking.
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Affiliation(s)
- Shen-Yuan Zheng
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013, Hunan Province, China
| | - Xin-Xing Wan
- Department of Endocrinology, Third Xiangya Hospital, Central South University, Changsha 410013, Hunan Province, China
| | - Piniel Alphayo Kambey
- Department of Neurobiology and Anatomy, Xuzhou Medical University, Xuzhou 221004, Jiangsu Province, China
| | - Yan Luo
- Clinical Medicine Eight-Year Program, Xiangya School of Medicine, Central South University, Changsha 410013, Hunan Province, China
| | - Xi-Min Hu
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013, Hunan Province, China
| | - Yi-Fan Liu
- Clinical Medicine Eight-Year Program, Xiangya School of Medicine, Central South University, Changsha 410013, Hunan Province, China
| | - Jia-Qi Shan
- Clinical Medicine Eight-Year Program, Xiangya School of Medicine, Central South University, Changsha 410013, Hunan Province, China
| | - Yu-Wei Chen
- Clinical Medicine Eight-Year Program, Xiangya School of Medicine, Central South University, Changsha 410013, Hunan Province, China
| | - Kun Xiong
- Department of Anatomy and Neurobiology, School of Basic Medical Science, Central South University, Changsha 410013, Hunan Province, China
- Key Laboratory of Emergency and Trauma, College of Emergency and Trauma, Hainan Medical University, Haikou 571199, Hainan Province, China
- Hunan Key Laboratory of Ophthalmology, Central South University, Changsha 410013, Hunan Province, China
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Standardized Quantitative Sensory Testing to Assess Insufficient Recovery of Touch Discrimination in Free Flap Surgery. Plast Reconstr Surg 2023; 151:429-438. [PMID: 36374559 DOI: 10.1097/prs.0000000000009860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND With major advances in microsurgical techniques, free tissue transfer has become a widely adopted approach to treat complex soft-tissue defects. However, sensory recovery is poor, leaving the anesthetic skin prone to injuries. METHODS Twenty-eight patients with 22 anterior lateral thigh flaps and six latissimus dorsi flaps on their extremities participated in the study. Quantitative sensory testing and two-point discrimination was performed in three test areas and one control on the contralateral unaffected extremity. Physical disability, mental health, quality of life, and characteristics of pain were assessed by the painDetect, Disabilities of the Arm, Shoulder, and Hand, Lower Extremity Functional Scale, and 12-Item Short Form questionnaires, respectively. RESULTS Somatosensory profiles of all flaps were characterized by an overall loss of nerve function. Small-fiber function was mostly recovered, whereas large-fiber function, and thus touch discrimination, was severely impaired. Mechanical detection thresholds improved over time and from center to the periphery. Reported pain was mild to moderate and correlated with decreased physical function. CONCLUSIONS Standardized quantitative sensory testing provides a useful tool kit to assess the sensory regeneration after surgical treatment of soft-tissue defects. After free tissue transfer, small-fiber function recovers with nerve ingrowth in a centripetal direction from the flap margins to the center, likely by way of collateral axonal sprouting from the undamaged nerves surrounding the flap. Myelinated fibers recover slowly and inefficiently. CLINICAL QUESTION/LEVEL OF EVIDENCE Therapeutic, IV.
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Zhou S, Wan L, Liu X, Hu D, Lu F, Chen X, Liang F. Diminished schwann cell repair responses play a role in delayed diabetes-associated wound healing. Front Physiol 2022; 13:814754. [PMID: 36620211 PMCID: PMC9813439 DOI: 10.3389/fphys.2022.814754] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
Diabetes mellitus is the most common metabolic disease associated with impaired wound healing. Recently, Schwann cells (SCs), the glia of the peripheral nervous system, have been suggested to accelerate normal skin wound healing. However, the roles of SCs in diabetic wound healing are not fully understood. In this study, Full-thickness wounds were made in the dorsal skin of C57/B6 mice and db/db (diabetic) mice. Tissue samples were collected at different time points, and immunohistochemical and immunofluorescence analyses were performed to detect markers of de-differentiated SCs, including myelin basic protein, Sox 10, p75, c-Jun, and Ki67. In addition, in vitro experiments were performed using rat SC (RSC96) and murine fibroblast (L929) cell lines to examine the effects of high glucose conditions (50 mM) on the de-differentiation of SCs and the paracrine effects of SCs on myofibroblast formation. Here, we found that, compared with that in normal mice, wound healing was delayed and SCs failed to rapidly activate a repair program after skin wound injury in diabetic mice. Furthermore, we found that SCs from diabetic mice displayed functional impairments in cell de-differentiation, cell-cycle re-entry, and cell migration. In vitro, hyperglycemia impaired RSC 96 cell de-differentiation, cell-cycle re-entry, and cell migration, as well as their paracrine effects on myofibroblast formation, including the secretion of TGF-β and Timp1. These results suggest that delayed wound healing in diabetes is due in part to a diminished SC repair response and attenuated paracrine effects on myofibroblast formation.
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Affiliation(s)
- Shaolong Zhou
- Aesthetic Medical School, Yichun University, Yichun, China
| | - Lingling Wan
- School of Chemical and Biological Engineering, Yichun University, Yichun, China,Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xu Liu
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Delin Hu
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Feng Lu
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China,*Correspondence: Feng Lu, ; Fangguo Liang, ; Xihang Chen,
| | - Xihang Chen
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China,*Correspondence: Feng Lu, ; Fangguo Liang, ; Xihang Chen,
| | - Fangguo Liang
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China,*Correspondence: Feng Lu, ; Fangguo Liang, ; Xihang Chen,
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Downregulation of LKB1/AMPK Signaling in Blood Mononuclear Cells Is Associated with the Severity of Guillain-Barre Syndrome. Cells 2022; 11:cells11182897. [PMID: 36139470 PMCID: PMC9496801 DOI: 10.3390/cells11182897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 11/30/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is an intracellular energy sensor that regulates metabolic and immune functions mainly through the inhibition of the mechanistic target of rapamycin (mTOR)-dependent anabolic pathways and the activation of catabolic processes such as autophagy. The AMPK/mTOR signaling pathway and autophagy markers were analyzed by immunoblotting in blood mononuclear cells of 20 healthy control subjects and 23 patients with an acute demyelinating form of Guillain–Barré syndrome (GBS). The activation of the liver kinase B1 (LKB1)/AMPK/Raptor signaling axis was significantly reduced in GBS compared to control subjects. In contrast, the phosphorylated forms of mTOR activator AKT and mTOR substrate 4EBP1, as well as the levels of autophagy markers LC3-II, beclin-1, ATG5, p62/sequestosome 1, and NBR1 were similar between the two groups. The downregulation of LKB1/AMPK signaling, but not the activation status of the AKT/mTOR/4EBP1 pathway or the levels of autophagy markers, correlated with higher clinical activity and worse outcomes of GBS. A retrospective study in a diabetic cohort of GBS patients demonstrated that treatment with AMPK activator metformin was associated with milder GBS compared to insulin/sulphonylurea therapy. In conclusion, the impairment of the LKB1/AMPK pathway might contribute to the development/progression of GBS, thus representing a potential therapeutic target in this immune-mediated peripheral polyneuropathy.
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Eftekharpour E, Fernyhough P. Oxidative Stress and Mitochondrial Dysfunction Associated with Peripheral Neuropathy in Type 1 Diabetes. Antioxid Redox Signal 2022; 37:578-596. [PMID: 34416846 DOI: 10.1089/ars.2021.0152] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Significance: This review highlights the many intracellular processes generating reactive oxygen species (ROS) in the peripheral nervous system in the context of type 1 diabetes. The major sources of superoxide and hydrogen peroxide (H2O2) are described, and scavenging systems are explained. Important roles of ROS in regulating normal redox signaling and in a disease setting, such as diabetes, contributing to oxidative stress and cellular damage are outlined. The primary focus is the role of hyperglycemia in driving elevated ROS production and oxidative stress contributing to neurodegeneration in diabetic neuropathy (within the dorsal root ganglia [DRG] and peripheral nerve). Recent Advances: Contributors to ROS production under high intracellular glucose concentration such as mitochondria and the polyol pathway are discussed. The primarily damaging impact of ROS on multiple pathways including mitochondrial function, endoplasmic reticulum (ER) stress, autophagy, and epigenetic signaling is covered. Critical Issues: There is a strong focus on mechanisms of diabetes-induced mitochondrial dysfunction and how this may drive ROS production (in particular superoxide). The mitochondrial sites of superoxide/H2O2 production via mitochondrial metabolism and aerobic respiration are reviewed. Future Directions: Areas for future development are highlighted, including the need to clarify diabetes-induced changes in autophagy and ER function in neurons and Schwann cells. In addition, more clarity is needed regarding the sources of ROS production at mitochondrial sites under high glucose concentration (and lack of insulin signaling). New areas of study should be introduced to investigate the role of ROS, nuclear lamina function, and epigenetic signaling under diabetic conditions in peripheral nerve.
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Affiliation(s)
- Eftekhar Eftekharpour
- Department of Physiology and Pathophysiology and Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Paul Fernyhough
- Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada.,Division of Neurodegenerative Disorders, St. Boniface Hospital Albrechtsen Research Centre, Winnipeg, Canada
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Ebenezer GJ, Pena MT, Daniel AS, Truman RW, Adams L, Duthie MS, Wagner K, Zampino S, Tolf E, Tsottles D, Polydefkis M. Mycobacterium leprae induces Schwann cell proliferation and migration in a denervated milieu following intracutaneous excision axotomy in nine-banded armadillos. Exp Neurol 2022; 352:114053. [PMID: 35341747 DOI: 10.1016/j.expneurol.2022.114053] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 02/15/2022] [Accepted: 03/21/2022] [Indexed: 01/23/2023]
Abstract
Nine-banded armadillos develop peripheral neuropathy after experimental Mycobacterium leprae infection that recapitulates human disease. We used an intracutaneous excision axotomy model to assess the effect of infection duration by M. leprae on axonal sprouting and Schwan cell density. 34 armadillos (17 naïve and 17 M. leprae-infected) underwent 3 mm skin biopsies to create an intracutaneous excision axotomy followed by a concentric 4-mm overlapping biopsy 3 and 12-months post M. leprae inoculation. A traditional distal leg biopsy was obtained at 15mo for intraepidermal nerve fiber (IENF) density. Serial skin sections were immunostained against a axons (PGP9.5, GAP43), and Schwann cells (p75, s100) to visualize regenerating nerves. Regenerative axons and proliferation of Schwann cells was measured and the rate of growth at each time point was assessed. Increasing anti-PGL antibody titers and intraneural M. leprae confirmed infection. 15mo following infection, there was evidence of axon loss with reduced distal leg IENF versus naïve armadillos, p < 0.05. This was associated with an increase in Schwann cell density (11,062 ± 2905 vs. 7561 ± 2715 cells/mm3, p < 0.01). Following excisional biopsy epidermal reinnervation increased monotonically at 30, 60 and 90 days; the regeneration rate was highest at 30 days, and decreased at 60 and 90 days. The reinnervation rate was highest among animals infected for 3mo vs those infected for 12mo or naïve animals (mean ± SD, 27.8 ± 7.2 vs.16.2 ± 5.8vs. 15.3 ± 6.5 mm/mm3, p < 0.05). The infected armadillos displayed a sustained Schwann cell proliferation across axotomy time points and duration of infection (3mo:182 ± 26, 12mo: 256 ± 126, naive: 139 ± 49 cells/day, p < 0.05). M. leprae infection is associated with sustained Schwann cell proliferation and distal limb nerve fiber loss. Rates of epidermal reinnervation were highest 3mo after infection and normalized by 12 mo of infection. We postulate that excess Schwann cell proliferation is the main pathogenic process and is deleterious to sensory axons. There is a compensatory initial increase in regeneration rates that may be an attempt to compensate for the injury, but it is not sustained and eventually followed by axon loss. Aberrant Schwann cell proliferation may be a novel therapeutic target to interrupt the pathogenic cascade of M. leprae.
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Affiliation(s)
| | - Maria T Pena
- DHHS/HRSA/HSB/National Hansen's Disease Program, Baton Rouge, LA 70816, USA
| | | | - Richard W Truman
- DHHS/HRSA/HSB/National Hansen's Disease Program, Baton Rouge, LA 70816, USA
| | - Linda Adams
- DHHS/HRSA/HSB/National Hansen's Disease Program, Baton Rouge, LA 70816, USA
| | | | - Kelly Wagner
- Neurology, Johns Hopkins University, Baltimore, MD, USA
| | | | - Eleanor Tolf
- Neurology, Johns Hopkins University, Baltimore, MD, USA
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Kan HW, Hsieh JH, Wang SW, Yeh TY, Chang MF, Tang TY, Chao CC, Feng FP, Hsieh ST. Nonpermissive skin environment impairs nerve regeneration in diabetes via Sec31a. Ann Neurol 2022; 91:821-833. [PMID: 35285061 DOI: 10.1002/ana.26347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/09/2022] [Accepted: 03/02/2022] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Although the microenvironment for peripheral nerve regeneration is permissive, such a mechanism is defective in diabetes, and the molecular mediators remain elusive. This study aimed to (1) investigate the relationship between skin innervation and collagen pathology in diabetic neuropathy and to (2) clarify the molecular alterations that occur in response to hyperglycemia and their effects on axon regeneration. METHODS We addressed this issue using two complementary systems: (1) human skin from patients with diabetic neuropathy and to (2) a coculture model of human dermal fibroblasts (HDFs) with rat dorsal root ganglia neurons in the context of intrinsic neuronal factor and extrinsic microenvironmental collagen and its biosynthetic pathways. RESULTS In diabetic neuropathy, the skin innervation of intraepidermal nerve fiber density (IENFd), a measure of sensory nerve degeneration, was reduced with similar expression of a growth associated protein 43, a marker of nerve regeneration. In contrast, the content and packing of collagen in the diabetic skin became more rigid than the control skin. Sec31a, a protein that regulates the collagen biosynthetic pathway, was upregulated and inversely correlated with IENFd. In the cell model, activated HDFs exposed to high-glucose medium enhanced the expression of Sec31a and collagen I through the activation of transforming growth factor β, a profibrotic molecule. Sec31a upregulation impaired neurite outgrowth. This effect was reversed by silencing Sec31a expression and neurite outgrowth was resumed. INTERPRETATION The current study provides evidence that Sec31a plays a key role in inhibiting nerve regeneration in diabetic neuropathy. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Hung-Wei Kan
- School of Medicine for International Students, College of Medicine, I-Shou University, Kaohsiung, 824005, Taiwan
| | - Jung-Hsien Hsieh
- Department of Surgery, National Taiwan University Hospital, Taipei, 100225, Taiwan
| | - Shih-Wei Wang
- Division of Rheumatology and Immunology, E-DA Hospital/I-Shou University, Kaohsiung, 824005, Taiwan
| | - Ti-Yen Yeh
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei, 100233, Taiwan
| | - Ming-Fong Chang
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei, 100233, Taiwan
| | - Tsz-Yi Tang
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei, 100233, Taiwan
| | - Chi-Chao Chao
- Department of Neurology, National Taiwan University Hospital, Taipei, 100225, Taiwan
| | - Fang-Ping Feng
- Department of Neurology, National Taiwan University Hospital, Taipei, 100225, Taiwan
| | - Sung-Tsang Hsieh
- Department of Anatomy and Cell Biology, National Taiwan University, Taipei, 100233, Taiwan.,Department of Neurology, National Taiwan University Hospital, Taipei, 100225, Taiwan.,Center of Precision Medicine, College of Medicine, National Taiwan University, Taipei, 100233, Taiwan
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12
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Bönhof GJ, Herder C, Ziegler D. Diagnostic Tools, Biomarkers, and Treatments in Diabetic polyneuropathy and Cardiovascular Autonomic Neuropathy. Curr Diabetes Rev 2022; 18:e120421192781. [PMID: 33845748 DOI: 10.2174/1573399817666210412123740] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/24/2021] [Accepted: 03/02/2021] [Indexed: 11/22/2022]
Abstract
The various manifestations of diabetic neuropathy, including distal symmetric sensorimotor polyneuropathy (DSPN) and cardiovascular autonomic neuropathy (CAN), are among the most prevalent chronic complications of diabetes. Major clinical complications of diabetic neuropathies, such as neuropathic pain, chronic foot ulcers, and orthostatic hypotension, are associated with considerable morbidity, increased mortality, and diminished quality of life. Despite the substantial individual and socioeconomic burden, the strategies to diagnose and treat diabetic neuropathies remain insufficient. This review provides an overview of the current clinical aspects and recent advances in exploring local and systemic biomarkers of both DSPN and CAN assessed in human studies (such as biomarkers of inflammation and oxidative stress) for better understanding of the underlying pathophysiology and for improving early detection. Current therapeutic options for DSPN are (I) causal treatment, including lifestyle modification, optimal glycemic control, and multifactorial risk intervention, (II) pharmacotherapy derived from pathogenetic concepts, and (III) analgesic treatment against neuropathic pain. Recent advances in each category are discussed, including non-pharmacological approaches, such as electrical stimulation. Finally, the current therapeutic options for cardiovascular autonomic complications are provided. These insights should contribute to a broader understanding of the various manifestations of diabetic neuropathies from both the research and clinical perspectives.
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Affiliation(s)
- Gidon J Bönhof
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Department of Endocrinology, Medical Faculty and University Hospital, Heinrich Heine University, Düsseldorf, Germany
| | - Christian Herder
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Department of Endocrinology, Medical Faculty and University Hospital, Heinrich Heine University, Düsseldorf, Germany
- German Center for Diabetes Research, Partner Düsseldorf, München-Neuherberg, Germany
| | - Dan Ziegler
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Department of Endocrinology, Medical Faculty and University Hospital, Heinrich Heine University, Düsseldorf, Germany
- German Center for Diabetes Research, Partner Düsseldorf, München-Neuherberg, Germany
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13
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Cutaneous innervation in impaired diabetic wound healing. Transl Res 2021; 236:87-108. [PMID: 34029747 PMCID: PMC8380642 DOI: 10.1016/j.trsl.2021.05.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/09/2021] [Accepted: 05/11/2021] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes is associated with several potential comorbidities, among them impaired wound healing, chronic ulcerations, and the requirement for lower extremity amputation. Disease-associated abnormal cellular responses, infection, immunological and microvascular dysfunction, and peripheral neuropathy are implicated in the pathogenesis of the wound healing impairment and the diabetic foot ulcer. The skin houses a dense network of sensory nerve afferents and nerve-derived modulators, which communicate with epidermal keratinocytes and dermal fibroblasts bidirectionally to effect normal wound healing after trauma. However, the mechanisms through which cutaneous innervation modulates wound healing are poorly understood, especially in humans. Better understanding of these mechanisms may provide the basis for targeted treatments for chronic diabetic wounds. This review provides an overview of wound healing pathophysiology with a focus on neural involvement in normal and diabetic wound healing, as well as future therapeutic perspectives to address the unmet needs of diabetic patients with chronic wounds.
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14
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Karlsson P, Provitera V, Caporaso G, Stancanelli A, Saltalamacchia AM, Borreca I, Manganelli F, Santoro L, Jensen TS, Nolano M. Increased peptidergic fibers as a potential cutaneous marker of pain in diabetic small fiber neuropathy. Pain 2021; 162:778-786. [PMID: 32833793 DOI: 10.1097/j.pain.0000000000002054] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 08/12/2020] [Indexed: 12/14/2022]
Abstract
ABSTRACT Diabetic polyneuropathy (DPN) is a common complication of diabetes and is often associated with neuropathic pain. The mechanisms underlying development and maintenance of painful DPN are largely unknown, and quantification of intraepidermal nerve fiber density from skin biopsy, one of the neuropathological gold standard when diagnosing DPN, does not differentiate between patients with and without pain. Identification of possible pain pathophysiological biomarkers in patients with painful DPN may increase our knowledge of mechanisms behind neuropathic pain. Animal models of painful DPN have been shown to have an increased density of peptidergic nerve fibers (substance P and calcitonin gene-related peptide). In this study, we performed a detailed skin biopsy analysis in a well-characterized group of DPN patients with primarily small fiber involvement, with and without pain, and in healthy controls and test for correlation between skin biopsy findings and pain intensity and quantitative sensory testing. We found that although there was no difference in intraepidermal nerve fiber density using protein gene product 9.5 between patients with and without pain, patients with pain had increased density of dermal peptidergic fibers containing substance P and calcitonin gene-related peptide compared with patients with painless DPN and healthy controls. Peptidergic nerve fiber density correlated with pain ratings in patients with pain (R = 0.33; P = 0.019), but not with quantitative sensory testing results. In this article, we show, for the first time in humans, an increased density of dermal peptidergic fibers in painful DPN. These findings provide new insight in the pathophysiological mechanisms of pain in diabetes and open the research towards new therapeutic targets.
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Affiliation(s)
- Pall Karlsson
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Core Center for Molecular Morphology, Section for Stereology and Microscopy , Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Vincenzo Provitera
- Istituti Clinici Scientifici Maugeri IRCCS, Department of Neurology, Institute of Telese Terme, Italy
| | - Giuseppe Caporaso
- Istituti Clinici Scientifici Maugeri IRCCS, Department of Neurology, Institute of Telese Terme, Italy
| | - Annamaria Stancanelli
- Istituti Clinici Scientifici Maugeri IRCCS, Department of Neurology, Institute of Telese Terme, Italy
| | - Anna Maria Saltalamacchia
- Istituti Clinici Scientifici Maugeri IRCCS, Department of Neurology, Institute of Telese Terme, Italy
| | - Ilaria Borreca
- Istituti Clinici Scientifici Maugeri IRCCS, Department of Neurology, Institute of Telese Terme, Italy
| | - Fiore Manganelli
- Department of Neuroscience and Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
| | - Lucio Santoro
- Department of Neuroscience and Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
| | - Troels Staehelin Jensen
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Maria Nolano
- Istituti Clinici Scientifici Maugeri IRCCS, Department of Neurology, Institute of Telese Terme, Italy
- Department of Neuroscience and Reproductive and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
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15
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Gibbons CH, Wang N, Kim JY, Campagnolo M, Freeman R. Skin Biopsy in Evaluation of Autonomic Disorders. Continuum (Minneap Minn) 2020; 26:200-212. [PMID: 31996629 DOI: 10.1212/con.0000000000000814] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE OF REVIEW This article provides an up-to-date assessment of the role of skin biopsy in the evaluation of autonomic disorders. The standard methodology for completing a skin biopsy, the anatomic structures of interest detected within a skin biopsy, and the disease states in which skin biopsies may provide valuable information are reviewed. RECENT FINDINGS Several recent advances in the studies of hereditary amyloidosis and the various degenerative synucleinopathies have demonstrated that simple skin biopsies can provide valuable pathologic evidence of neurologic disease. In addition to diagnosis of the underlying disorder, skin biopsies provide a quantitative structural measurement of the associated autonomic damage. SUMMARY Skin biopsies are making great inroads into the study of autonomic and peripheral nerve disorders. Complex immunohistochemical staining protocols are challenging to complete, but the rich data derived from these studies in the diagnosis and monitoring of different disease states suggest that the role of skin biopsies in the study of the autonomic nervous system will continue to expand in the years to come.
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16
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Xu X, Wang W, Wang Z, Lv J, Xu X, Xu J, Yang J, Zhu X, Lu Y, Duan W, Huang X, Wang J, Zhou J, Shen X. DW14006 as a Direct AMPKα Activator Ameliorates Diabetic Peripheral Neuropathy in Mice. Diabetes 2020; 69:1974-1988. [PMID: 32647036 DOI: 10.2337/db19-1084] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 06/29/2020] [Indexed: 11/13/2022]
Abstract
Diabetic peripheral neuropathy (DPN) is a long-term complication of diabetes with a complicated pathogenesis. AMP-activated protein kinase (AMPK) senses oxidative stress, and mitochondrial function plays a central role in the regulation of DPN. Here, we reported that DW14006 (2-[3-(7-chloro-6-[2'-hydroxy-(1,1'-biphenyl)-4-yl]-2-oxo-1,2-dihydroquinolin-3-yl)phenyl]acetic acid) as a direct AMPKα activator efficiently ameliorated DPN in both streptozotocin (STZ)-induced type 1 and BKS db/db type 2 diabetic mice. DW14006 administration highly enhanced neurite outgrowth of dorsal root ganglion neurons and improved neurological function in diabetic mice. The underlying mechanisms have been intensively investigated. DW14006 treatment improved mitochondrial bioenergetics profiles and restrained oxidative stress and inflammation in diabetic mice by targeting AMPKα, which has been verified by assay against the STZ-induced diabetic mice injected with adeno-associated virus 8-AMPKα-RNAi. To our knowledge, our work might be the first report on the amelioration of the direct AMPKα activator on DPN by counteracting multiple risk factors including mitochondrial dysfunction, oxidative stress, and inflammation, and DW14006 has been highlighted as a potential leading compound in the treatment of DPN.
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Affiliation(s)
- Xu Xu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Wei Wang
- Department of Medicinal Chemistry, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Zhengyu Wang
- Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing, China
| | - Jianlu Lv
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Xiaoju Xu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jiawen Xu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Juanzhen Yang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Xialin Zhu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yin Lu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Wenhu Duan
- Department of Medicinal Chemistry, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xi Huang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jiaying Wang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jinpei Zhou
- Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing, China
| | - Xu Shen
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
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17
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Gonçalves NP, Jager SE, Richner M, Murray SS, Mohseni S, Jensen TS, Vaegter CB. Schwann cell p75 neurotrophin receptor modulates small fiber degeneration in diabetic neuropathy. Glia 2020; 68:2725-2743. [PMID: 32658363 DOI: 10.1002/glia.23881] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/10/2020] [Accepted: 06/10/2020] [Indexed: 02/06/2023]
Abstract
Diabetic neuropathy has an incidence as high as 50% of diabetic patients and is characterized by damage to neurons, Schwann cells and blood vessels within the peripheral nervous system. The low-affinity neurotrophin receptor p75 (p75NTR ), particularly expressed by the Schwann cells in the peripheral nerve, has previously been reported to play a role in developmental myelination and cell survival/death. Increased levels of p75NTR , in the endoneurium and plasma from diabetic patients and rodent models of disease, have been observed, proposing that this receptor might be involved in the pathogenesis of diabetic neuropathy. Therefore, in this study, we addressed this hypothesis by utilizing a mouse model of selective nerve growth factor receptor (Ngfr) deletion in Schwann cells (SC-p75NTR -KO). Electron microscopy of sciatic nerves from mice with high fat diet induced obesity demonstrated how loss of Schwann cell-p75NTR aggravated axonal atrophy and loss of C-fibers. RNA sequencing disclosed several pre-clinical signaling alterations in the diabetic peripheral nerves, dependent on Schwann cell p75NTR signaling, specially related with lysosome, phagosome, and immune pathways. Morphological and biochemical analyses identified abundant lysosomes and autophagosomes in the C-fiber axoplasm of the diabetic SC-p75NTR -KO nerves, which together with increased Cathepsin B protein levels corroborates gene upregulation from the phagolysosomal pathways. Altogether, this study demonstrates that Schwann cell p75NTR deficiency amplifies diabetic neuropathy disease by triggering overactivation of immune-related pathways and increased lysosomal stress.
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Affiliation(s)
- Nádia P Gonçalves
- Department of Biomedicine, Danish Research Institute of Translational Neuroscience-DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus C, Denmark.,International Diabetic Neuropathy Consortium (IDNC), Aarhus University Hospital, Aarhus N, Denmark
| | - Sara E Jager
- Department of Biomedicine, Danish Research Institute of Translational Neuroscience-DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus C, Denmark.,Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - Mette Richner
- Department of Biomedicine, Danish Research Institute of Translational Neuroscience-DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus C, Denmark
| | - Simon S Murray
- Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Victoria, Australia
| | - Simin Mohseni
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Troels S Jensen
- International Diabetic Neuropathy Consortium (IDNC), Aarhus University Hospital, Aarhus N, Denmark.,Department of Neurology and Danish Pain Research Center, Aarhus University, Aarhus C, Denmark
| | - Christian B Vaegter
- Department of Biomedicine, Danish Research Institute of Translational Neuroscience-DANDRITE, Nordic-EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus C, Denmark.,International Diabetic Neuropathy Consortium (IDNC), Aarhus University Hospital, Aarhus N, Denmark
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18
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Abstract
PURPOSE The purpose of this study was to establish an age-dependent normative range and factors affecting the migration rate of the corneal subbasal nerve plexus in a healthy control population. METHODS Corneal nerve migration rate was measured in 60 healthy participants grouped by age: A, aged 20 to 39 years (n = 20); B, 40 to 59 years (n = 20); and C, 60 to 79 years (n = 20). Laser-scanning corneal confocal microscopy was performed on the right eye of all participants at baseline and again after 3 weeks. Fully automated software was used to montage the frames. Distinctive nerve landmarks were manually reidentified between the two montages, and a software program was developed to measure the migration of these landmark points to determine corneal nerve migration rate in micrometers per week (μm/wk). RESULTS The mean ± SD age of all participants in the study was 47.5 ± 15.5 years; 62% of participants were male. The average corneal nerve migration rates of groups A, B, and C were 42.0 ± 14.0, 42.3 ± 15.5, and 42.0 ± 10.8 μm/wk, respectively (P = .99). There was no difference in corneal nerve migration rate between male (41.1 ± 13.5 μm/wk) and female (43.7 ± 13.2 μm/wk) participants (P = .47). There was no significant correlation between age (P = .97), smoking (P = .46), alcohol use (P = .61), and body mass index (P = .49, respectively) with corneal nerve migration rate. However, exercise frequency correlated significantly (P = .04) with corneal nerve migration rate. CONCLUSIONS Corneal nerve migration rate varies in healthy individuals and is not affected by age, sex, or body mass index but is related to physical activity.
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19
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Khoshnoodi M, Truelove S, Polydefkis M. Effect of diabetes type on long-term outcome of epidermal axon regeneration. Ann Clin Transl Neurol 2019; 6:2088-2096. [PMID: 31560176 PMCID: PMC6801164 DOI: 10.1002/acn3.50904] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/05/2019] [Indexed: 12/12/2022] Open
Abstract
Objective To assess the effect of diabetes type on the long‐term rate and extent of epidermal nerve regeneration. Methods Subjects with well controlled type 1 diabetes mellitus (n = 11) or type 2 diabetes mellitus (n = 36), with normal nerve conduction studies and baseline intraepidermal nerve fiber density (IENFD), and healthy controls (n = 10) underwent chemical axotomy of the intraepidermal nerves at the thigh using topical capsaicin. Skin biopsies were performed at 30, 90, 150, and 180 days post‐axotomy. Results After 180 days, IENFD in diabetic subjects remained significantly below baseline levels, while healthy controls returned to normal. At each time point, regeneration rates were significantly slower among diabetic subjects, although type 1 subjects regenerated significantly faster and achieved higher percentages of baseline IENFD compared with type 2. Interpretation Among diabetic patients, nerve injury recovery is likely to take significantly longer than in healthy individuals, and remains incomplete, particularly among type 2 patients. This may partially explain the progression of neuropathy among diabetic patients: damage accumulates because nerve recovery is slowed and incomplete. Furthermore, these findings support caution when recommending certain procedures, such as carpal tunnel repair, to patients with progressed diabetic disease.
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Affiliation(s)
| | - Shaun Truelove
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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20
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Liu C, Chen G, Bentley AR, Doumatey A, Zhou J, Adeyemo A, Yang J, Rotimi C. Genome-wide association study for proliferative diabetic retinopathy in Africans. NPJ Genom Med 2019; 4:20. [PMID: 31482010 PMCID: PMC6715701 DOI: 10.1038/s41525-019-0094-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 08/07/2019] [Indexed: 11/08/2022] Open
Abstract
Proliferative diabetic retinopathy (PDR) is a sight-threatening complication of diabetes that is associated with longer duration of diabetes and poor glycemic control under a genetic susceptibility background. Although GWAS of PDR have been conducted in Europeans and Asians, none has been done in continental Africans, a population at increased risk for PDR. Here, we report a GWAS of PDR among Africans. PDR cases (n = 64) were T2D patients with neovascularization in the retina and/or retinal detachment. Controls (n = 227) were T2D patients without listed eye complications despite high risk (T2D duration ≥10 years and fasting blood glucose >169 mg/dl). Replication was assessed in African Americans enrolled in the ARIC study. We identified 4 significant loci: WDR72, HLA-B, GAP43/RP11-326J18.1, and AL713866.1. At WDR72 the most strongly associated SNPs were rs12906891 (MAF = 0.071; p = 9.68 × 10-10; OR = 1.46, 95% CI [1.30,1.64]) and rs11070992 (MAF = 0.14; p = 4.23 × 10-8; OR = 1.28, 95%CI [1.17-1.40]). rs11070992 replicated in African Americans (p = 0.04). Variants in this gene have been associated with diabetic retinopathy, glycemic control, revascularization, and kidney disease.
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Affiliation(s)
- Chang Liu
- The Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD USA
- Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, 10730 China
- Beijing Diabetes institute, Beijing, 100730 China
| | - Guanjie Chen
- The Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD USA
| | - Amy R. Bentley
- The Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD USA
| | - Ayo Doumatey
- The Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD USA
| | - Jie Zhou
- The Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD USA
| | - Adebowale Adeyemo
- The Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD USA
| | - Jinkui Yang
- Department of Endocrinology, Beijing Tongren Hospital, Capital Medical University, Beijing, 10730 China
- Beijing Diabetes institute, Beijing, 100730 China
| | - Charles Rotimi
- The Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD USA
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21
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Mangus LM, Rao DB, Ebenezer GJ. Intraepidermal Nerve Fiber Analysis in Human Patients and Animal Models of Peripheral Neuropathy: A Comparative Review. Toxicol Pathol 2019; 48:59-70. [PMID: 31221022 DOI: 10.1177/0192623319855969] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Analysis of intraepidermal nerve fibers (IENFs) in skin biopsy samples has become a standard clinical tool for diagnosing peripheral neuropathies in human patients. Compared to sural nerve biopsy, skin biopsy is safer, less invasive, and can be performed repeatedly to facilitate longitudinal assessment. Intraepidermal nerve fiber analysis is also more sensitive than conventional nerve histology or electrophysiological tests for detecting damage to small-diameter sensory nerve fibers. The techniques used for IENF analysis in humans have been adapted for large and small animal models and successfully used in studies of diabetic neuropathy, chemotherapy-induced peripheral neuropathy, HIV-associated sensory neuropathy, among others. Although IENF analysis has yet to become a routine end point in nonclinical safety testing, it has the potential to serve as a highly relevant indicator of sensory nerve fiber status in neurotoxicity studies, as well as development of neuroprotective and neuroregenerative therapies. Recently, there is also interest in the evaluation of IENF via skin biopsy as a biomarker of small fiber neuropathy in the regulatory setting. This article provides an overview of the anatomic and pathophysiologic principles behind IENF analysis, its use as a diagnostic tool in humans, and applications in animal models with focus on comparative methodology and considerations for study design.
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Affiliation(s)
- Lisa M Mangus
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University, Baltimore, MD, USA.,Department of Pathology, Johns Hopkins University, Baltimore, MD, USA
| | - Deepa B Rao
- US Food and Drug Administration, Center for Drug Evaluation and Research, Silver Spring, MD, USA
| | - Gigi J Ebenezer
- Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
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22
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Chen J, Liu W, Yi H, Hu X, Peng L, Yang F. MicroRNA-155 mimics ameliorates nerve conduction velocities and suppresses hyperglycemia-induced pro-inflammatory genes in diabetic peripheral neuropathic mice. Am J Transl Res 2019; 11:3905-3918. [PMID: 31312398 PMCID: PMC6614614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 05/26/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND MicroRNA-155 (miR-155) regulates inflammatory cytokines, however its role in Diabetic neuropathy (DN) remains unexplored. METHODS A strain of mice (db/db) having type II diabetes were studied for expression of miR-155 in plasma and in sciatic nerves. The miR-155 mimic treated mice were studied for effect on motor and sensory nerve conduction velocities along with blood perfusion in sciatic nerves and response to thermal stimuli test. The mice were evaluated for density of blood vessels, quantity of intra-epidermal nerve fibers (IENF), diameters of axons & thickness of myelin sheath of sciatic nerves. Bioinformatics analysis was done to confirm target genes of miR-155. RESULTS The db/db mice showed significant suppression of miR-155 in sciatic nerves. The treatment of miR-155 mimic elevated levels of miR-155 in both sciatic nerves and plasma; it also enhanced the blood flow in sciatic nerves and velocities of conduction for both sensory and motor nerves. The treatment showed significant decrease in the threshold to thermal stimuli in db/db mice. A significant improvement in density of perfused blood vessels was observed, along with elevation of IENF and thickness of myelin and axon diameters of sciatic nerves. The treatment attenuated levels of TNF-α, iNOS, IL1-β and Ym1. Microarray analysis showed that the treatment decreased the expression of proinflammatory genes TRAF2 and Notch2, SORT1 and were identified as target by in silico studies. CONCLUSION Treatment of miR-155 mimic in db/db mice attenuated DN, suppressed diabetic associated proinflammatory genes and confirmed miR-155 mimic as therapeutic strategy for treating DN.
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Affiliation(s)
- Ji Chen
- Department of Endocrinology, The First Affiliated Hospital of University of South ChinaHunan Province 421001, China
| | - Wenjie Liu
- Department of Anesthesiology, The First Affiliated Hospital of University of South ChinaHunan Province 421001, China
| | - Han Yi
- Department of Anesthesiology, The First Affiliated Hospital of University of South ChinaHunan Province 421001, China
| | - Xiaoling Hu
- Department of Anesthesiology, The First Affiliated Hospital of University of South ChinaHunan Province 421001, China
| | - Liangyu Peng
- Department of Anesthesiology, The First Affiliated Hospital of University of South ChinaHunan Province 421001, China
| | - Fengrui Yang
- Department of Anesthesiology, The First Affiliated Hospital of University of South ChinaHunan Province 421001, China
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23
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Princz A, Kounakis K, Tavernarakis N. Mitochondrial contributions to neuronal development and function. Biol Chem 2019; 399:723-739. [PMID: 29476663 DOI: 10.1515/hsz-2017-0333] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 02/20/2018] [Indexed: 12/17/2022]
Abstract
Mitochondria are critical to tissues and organs characterized by high-energy demands, such as the nervous system. They provide essential energy and metabolites, and maintain Ca2+ balance, which is imperative for proper neuronal function and development. Emerging findings further underline the role of mitochondria in neurons. Technical advances in the last decades made it possible to investigate key mechanisms in neuronal development and the contribution of mitochondria therein. In this article, we discuss the latest findings relevant to the involvement of mitochondria in neuronal development, placing emphasis on mitochondrial metabolism and dynamics. In addition, we survey the role of mitochondrial energy metabolism and Ca2+ homeostasis in proper neuronal function, and the involvement of mitochondria in axon myelination.
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Affiliation(s)
- Andrea Princz
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, N. Plastira 100, Vassilika Vouton, Heraklion 70013, Crete, Greece
- Department of Biology, University of Crete, N. Plastira 100, Vassilika Vouton, Heraklion 70013, Crete, Greece
| | - Konstantinos Kounakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, N. Plastira 100, Vassilika Vouton, Heraklion 70013, Crete, Greece
- Department of Basic Sciences, Faculty of Medicine, University of Crete, N. Plastira 100, Vassilika Vouton, Heraklion 70013, Crete, Greece
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, N. Plastira 100, Vassilika Vouton, Heraklion 70013, Crete, Greece
- Department of Basic Sciences, Faculty of Medicine, University of Crete, N. Plastira 100, Vassilika Vouton, Heraklion 70013, Crete, Greece
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Bönhof GJ, Herder C, Strom A, Papanas N, Roden M, Ziegler D. Emerging Biomarkers, Tools, and Treatments for Diabetic Polyneuropathy. Endocr Rev 2019; 40:153-192. [PMID: 30256929 DOI: 10.1210/er.2018-00107] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 08/23/2018] [Indexed: 12/12/2022]
Abstract
Diabetic neuropathy, with its major clinical sequels, notably neuropathic pain, foot ulcers, and autonomic dysfunction, is associated with substantial morbidity, increased risk of mortality, and reduced quality of life. Despite its major clinical impact, diabetic neuropathy remains underdiagnosed and undertreated. Moreover, the evidence supporting a benefit for causal treatment is weak at least in patients with type 2 diabetes, and current pharmacotherapy is largely limited to symptomatic treatment options. Thus, a better understanding of the underlying pathophysiology is mandatory for translation into new diagnostic and treatment approaches. Improved knowledge about pathogenic pathways implicated in the development of diabetic neuropathy could lead to novel diagnostic techniques that have the potential of improving the early detection of neuropathy in diabetes and prediabetes to eventually embark on new treatment strategies. In this review, we first provide an overview on the current clinical aspects and illustrate the pathogenetic concepts of (pre)diabetic neuropathy. We then describe the biomarkers emerging from these concepts and novel diagnostic tools and appraise their utility in the early detection and prediction of predominantly distal sensorimotor polyneuropathy. Finally, we discuss the evidence for and limitations of the current and novel therapy options with particular emphasis on lifestyle modification and pathogenesis-derived treatment approaches. Altogether, recent years have brought forth a multitude of emerging biomarkers reflecting different pathogenic pathways such as oxidative stress and inflammation and diagnostic tools for an early detection and prediction of (pre)diabetic neuropathy. Ultimately, these insights should culminate in improving our therapeutic armamentarium against this common and debilitating or even life-threatening condition.
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Affiliation(s)
- Gidon J Bönhof
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christian Herder
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, Munich-Neuherberg, Neuherberg, Partner Düsseldorf, Düsseldorf, Germany.,Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Alexander Strom
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, Munich-Neuherberg, Neuherberg, Partner Düsseldorf, Düsseldorf, Germany
| | - Nikolaos Papanas
- Second Department of Internal Medicine, Diabetes Center, Diabetic Foot Clinic, Democritus University of Thrace, Alexandroupolis, Greece
| | - Michael Roden
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, Munich-Neuherberg, Neuherberg, Partner Düsseldorf, Düsseldorf, Germany.,Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Dan Ziegler
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, Munich-Neuherberg, Neuherberg, Partner Düsseldorf, Düsseldorf, Germany.,Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
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25
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Taylor S, Mehina E, White E, Reeson P, Yongblah K, Doyle KP, Brown CE. Suppressing Interferon-γ Stimulates Microglial Responses and Repair of Microbleeds in the Diabetic Brain. J Neurosci 2018; 38:8707-8722. [PMID: 30201775 PMCID: PMC6596226 DOI: 10.1523/jneurosci.0734-18.2018] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/06/2018] [Accepted: 08/06/2018] [Indexed: 12/15/2022] Open
Abstract
Microcirculatory damage is a common complication for those with vascular risk factors, such as diabetes. To resolve vascular insults, the brain's immune cells (microglia) must rapidly envelop the site of injury. Currently, it is unknown whether Type 1 diabetes, a condition associated with chronic immune system dysfunction, alters microglial responses to damage and what mechanisms are responsible. Using in vivo two-photon microscopy in adult male mice, we show that microglial envelopment of laser-induced cerebral microbleeds is diminished in a hyperglycemic mouse model of Type 1 diabetes, which could not be fully rescued with chronic insulin treatment. Microglia were important for vessel repair because reduced microglial accumulation in diabetic mice or near-complete depletion in healthy controls was associated with greater secondary leakage of the damaged vessel. Broadly suppressing inflammation with dexamethasone in diabetic mice but not healthy controls, significantly enhanced microglial responses to microbleeds and attenuated secondary vessel leakage. These enhancements were associated with changes in IFN-γ signaling because dexamethasone suppressed abnormally high levels of IFN-γ protein levels in brain and blood serum of diabetic mice. Further, blocking IFN-γ in diabetic mice with neutralizing antibodies restored normal microglial chemotaxic responses and purinoceptor P2ry12 gene expression, as well as mitigated secondary leakage. These results suggest that abnormal IFN-γ signaling disrupts microglial function in the diabetic brain, and that immunotherapies targeting IFN-γ can stimulate microglial repair of damaged vessels.SIGNIFICANCE STATEMENT Although Type 1 diabetes is an established risk factor for vascular complications, such as microbleeds, and is known to hinder wound healing in the body, no study has examined how diabetes impacts the brain's innate immune reparative response (involving cells called microglia) to vascular injury. Here we show that microglial responses to brain microbleeds were diminished in diabetic animals, which also exacerbated secondary leakage from damaged vessels. These impairments were related to abnormally high levels of the proinflammatory cytokine IFN-γ because reducing IFN-γ with immunosuppressant drugs or blocking antibodies helped restore normal microglial responses and repair of damaged vessels. These data highlight the use of IFN-γ modulating therapeutics to enhance vascular repair in at-risk populations.
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Affiliation(s)
- Stephanie Taylor
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Eslam Mehina
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Emily White
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Patrick Reeson
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Kevin Yongblah
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Kristian P Doyle
- Department of Immunobiology, University of Arizona College of Medicine, Tucson, Arizona 85724, and
| | - Craig E Brown
- Division of Medical Sciences, University of Victoria, Victoria, British Columbia V8P 5C2, Canada,
- Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 2A1, Canada
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26
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Sloan G, Shillo P, Selvarajah D, Wu J, Wilkinson ID, Tracey I, Anand P, Tesfaye S. A new look at painful diabetic neuropathy. Diabetes Res Clin Pract 2018; 144:177-191. [PMID: 30201394 DOI: 10.1016/j.diabres.2018.08.020] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 08/24/2018] [Indexed: 02/06/2023]
Abstract
The prevalence of diabetes mellitus and its chronic complications continue to increase alarmingly. Consequently, the massive expenditure on diabetic distal symmetrical polyneuropathy (DSPN) and its sequelae, will also likely rise. Up to 50% of patients with diabetes develop DSPN, and about 20% develop neuropathic pain (painful-DSPN). Painful-DSPN can cast a huge burden on sufferers' lives with increased rates of unemployment, mental health disorders and physical co-morbidities. Unfortunately, due to limited understanding of the mechanisms leading to painful-DSPN, current treatments remain inadequate. Recent studies examining the pathophysiology of painful-DSPN have identified maladaptive alterations at the level of both the peripheral and central nervous systems. Additionally, genetic studies have suggested that patients with variants of voltage gated sodium channels may be more at risk of developing neuropathic pain in the presence of a disease trigger such as diabetes. We review the recent advances in genetics, skin biopsy immunohistochemistry and neuro-imaging, which have the potential to further our understanding of the condition, and identify targets for new mechanism based therapies.
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Affiliation(s)
- Gordon Sloan
- Diabetes Research Unit, Sheffield Teaching Hospitals NHS Foundation Trust & Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom
| | - Pallai Shillo
- Diabetes Research Unit, Sheffield Teaching Hospitals NHS Foundation Trust & Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom
| | - Dinesh Selvarajah
- Diabetes Research Unit, Sheffield Teaching Hospitals NHS Foundation Trust & Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom
| | - Jing Wu
- Department of Endocrinology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Iain D Wilkinson
- Diabetes Research Unit, Sheffield Teaching Hospitals NHS Foundation Trust & Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom
| | - Irene Tracey
- FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Praveen Anand
- Peripheral Neuropathy Unit, Centre for Clinical Translation, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Solomon Tesfaye
- Diabetes Research Unit, Sheffield Teaching Hospitals NHS Foundation Trust & Academic Unit of Radiology, University of Sheffield, Sheffield, United Kingdom.
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Liu XS, Fan B, Szalad A, Jia L, Wang L, Wang X, Pan W, Zhang L, Zhang R, Hu J, Zhang XM, Chopp M, Zhang ZG. MicroRNA-146a Mimics Reduce the Peripheral Neuropathy in Type 2 Diabetic Mice. Diabetes 2017; 66:3111-3121. [PMID: 28899883 PMCID: PMC5697943 DOI: 10.2337/db16-1182] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 09/02/2017] [Indexed: 12/27/2022]
Abstract
MicroRNA-146a (miR-146a) regulates multiple immune diseases. However, the role of miR-146a in diabetic peripheral neuropathy (DPN) has not been investigated. We found that mice (db/db) with type 2 diabetes exhibited substantial downregulation of miR-146a in sciatic nerve tissue. Systemic administration of miR-146a mimics to diabetic mice elevated miR-146a levels in plasma and sciatic nerve tissue and substantially increased motor and sensory nerve conduction velocities by 29 and 11%, respectively, and regional blood flow by 50% in sciatic nerve tissue. Treatment with miR-146a mimics also considerably decreased the response in db/db mice to thermal stimuli thresholds. Histopathological analysis showed that miR-146a mimics markedly augmented the density of fluorescein isothiocyanate-dextran-perfused blood vessels and increased the number of intraepidermal nerve fibers, myelin thickness, and axonal diameters of sciatic nerves. In addition, miR-146a treatment reduced and increased classically and alternatively activated macrophage phenotype markers, respectively. Analysis of miRNA target array revealed that miR-146a mimics greatly suppressed expression of many proinflammatory genes and downstream related cytokines. Collectively, our data indicate that treatment of diabetic mice with miR-146a mimics robustly reduces DPN and that suppression of hyperglycemia-induced proinflammatory genes by miR-146a mimics may underlie its therapeutic effect.
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Affiliation(s)
- Xian Shuang Liu
- Department of Neurology, Henry Ford Health System, Detroit, MI
| | - Baoyan Fan
- Department of Neurology, Henry Ford Health System, Detroit, MI
| | | | - Longfei Jia
- Department of Neurology, Henry Ford Health System, Detroit, MI
| | - Lei Wang
- Department of Neurology, Henry Ford Health System, Detroit, MI
| | - Xinli Wang
- Department of Neurology, Henry Ford Health System, Detroit, MI
| | - Wanlong Pan
- Department of Neurology, Henry Ford Health System, Detroit, MI
- Sichuan Key Laboratory of Medical Imaging and Department of Microbiology and Immunology, North Sichuan Medical College, Nanchong, Sichuan, China
| | - Li Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI
| | - Ruilan Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI
| | - Jiani Hu
- Department of Radiology, Wayne State University, Detroit, MI
| | - Xiao Ming Zhang
- Sichuan Key Laboratory of Medical Imaging and Department of Radiology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan, China
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, MI
- Department of Physics, Oakland University, Rochester, MI
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28
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Bönhof GJ, Strom A, Püttgen S, Ringel B, Brüggemann J, Bódis K, Müssig K, Szendroedi J, Roden M, Ziegler D. Patterns of cutaneous nerve fibre loss and regeneration in type 2 diabetes with painful and painless polyneuropathy. Diabetologia 2017; 60:2495-2503. [PMID: 28914336 DOI: 10.1007/s00125-017-4438-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 08/02/2017] [Indexed: 12/17/2022]
Abstract
AIMS/HYPOTHESIS The determinants and mechanisms of the development of diabetic sensorimotor polyneuropathy as a painful (DSPN+p) or painless (DSPN-p) entity remain unclear. We examined the degree of cutaneous nerve fibre loss and regeneration in individuals with type 2 diabetes with DSPN+p or DSPN-p compared with individuals with recent-onset type 2 diabetes and corresponding healthy volunteers. METHODS In this cross-sectional study, skin biopsies taken from the distal lateral calf were obtained from individuals with recent-onset type 2 diabetes (n = 32) from the German Diabetes Study, with DSPN+p (n = 34) and DSPN-p (n = 32) from the PROPANE study, and volunteers with normal glucose tolerance (n = 50). Double immunofluorescence staining for protein gene product 9.5 (PGP9.5) (pan-neuronal marker) and growth-associated protein 43 (GAP-43) (nerve regeneration marker) was applied to assess intraepidermal nerve fibre density (IENFD) and length (IENFL) and dermal nerve fibre length (DNFL). DSPN was diagnosed using the modified Toronto Consensus (2011) criteria, while neuropathic pain was assessed using an 11-point Numerical Rating Scale. RESULTS After adjustment for age, sex, BMI and HbA1c, IENFD and IENFL were reduced for both markers in individuals with recent-onset diabetes and both DSPN groups compared with control participants (all p < 0.05), but did not differ between the DSPN groups. The DNFL GAP-43/PGP9.5 ratio was higher in the DSPN+p and DSPN-p groups compared with control participants (1.18 ± 0.28 and 1.07 ± 0.10 vs 1.02 ± 0.10; p ≤ 0.05) and in the DSPN + p group compared with DSPN-p (p < 0.05). Correlation analyses showed distinct inverse associations between the DNFL GAP-43/PGP9.5 ratio and PGP9.5 positive IENFD as well as DNFL (IENFD: β = -0.569, DNFL: β = -0.639; both p < 0.0001) in individuals with type 2 diabetes, but not in the control group. A similar pattern was found for correlations between the DNFL GAP-43/PGP9.5 ratio and peripheral nerve function tests. CONCLUSIONS/INTERPRETATION Dermal nerve fibre regeneration is enhanced in DSPN, particularly in DSPN+p, and increases with advancing intraepidermal nerve fibre loss. These data suggest that, despite progressive epidermal fibre loss, dermal nerve repair is preserved, particularly in DSPN+p, but fails to adequately counteract epidermal neurodegenerative processes.
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Affiliation(s)
- Gidon J Bönhof
- Institute for Clinical Diabetology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Auf'm Hennekamp 65, 40225, Düsseldorf, Germany
| | - Alexander Strom
- Institute for Clinical Diabetology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Auf'm Hennekamp 65, 40225, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Munich, Neuherberg, Germany
| | - Sonja Püttgen
- Institute for Clinical Diabetology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Auf'm Hennekamp 65, 40225, Düsseldorf, Germany
| | - Bernd Ringel
- Institute for Clinical Diabetology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Auf'm Hennekamp 65, 40225, Düsseldorf, Germany
| | - Jutta Brüggemann
- Institute for Clinical Diabetology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Auf'm Hennekamp 65, 40225, Düsseldorf, Germany
| | - Kálmán Bódis
- Institute for Clinical Diabetology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Auf'm Hennekamp 65, 40225, Düsseldorf, Germany
| | - Karsten Müssig
- Institute for Clinical Diabetology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Auf'm Hennekamp 65, 40225, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Munich, Neuherberg, Germany
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Julia Szendroedi
- Institute for Clinical Diabetology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Auf'm Hennekamp 65, 40225, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Munich, Neuherberg, Germany
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Michael Roden
- Institute for Clinical Diabetology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Auf'm Hennekamp 65, 40225, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Munich, Neuherberg, Germany
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Dan Ziegler
- Institute for Clinical Diabetology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University, Auf'm Hennekamp 65, 40225, Düsseldorf, Germany.
- German Center for Diabetes Research (DZD), Munich, Neuherberg, Germany.
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany.
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Investigation of the Effect of Diabetes on Radiculopathy Induced by Nucleus Pulposus Application to the DRG in a Spontaneously Diabetic Rat Model. Spine (Phila Pa 1976) 2017; 42:1749-1756. [PMID: 28658037 DOI: 10.1097/brs.0000000000002299] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN A controlled, interventional animal study. OBJECTIVE The aim of this study was to evaluate the effect of diabetes mellitus (DM) on radiculopathy due to lumbar disc herniation (LDH), by investigating pain-related behavior and the expression of tumor necrosis factor-alpha (TNF-α) and growth-associated protein 43 (GAP43) in type 2 diabetic rats following application of nucleus pulposus (NP) to the dorsal root ganglion (DRG). SUMMARY OF BACKGROUND DATA Previous clinical studies suggested negative effects of DM on radiculopathy due to LDH, and that inflammation and nerve regeneration could interact with DM and radiculopathy. METHODS We applied autologous NP to the left L5 DRG of adult male Wistar rats and Goto-Kakizaki rats. Behavioral testing measured the mechanical withdrawal threshold of rats. We immunohistochemically evaluated the localization of ionized calcium-binding adapter molecule-1 (Iba-1), receptor of advanced glycation end products (RAGE), and TNF-α in DRGs. TNF-α and GAP43 expression levels in DRG were determined by quantitative real-time PCR and western blotting. RESULTS The mechanical withdrawal threshold significantly declined in the non-DM NP group compared with the non-DM sham group for 28 days, whereas the decline in threshold extended to 35 days in the DM NP group compared with the DM sham group. RAGE and TNF-α expression in DRGs was colocalized in Iba-1 positive cells. The non-DM NP rats had higher TNF-α protein expression levels versus the non-DM sham rats on day 7, and the DM NP group had higher levels versus the DM sham group on days 7 and 14. The non-DM NP group had higher GAP43 mRNA expression than the non-DM sham group for 28 days, while the DM NP group had a higher level than the DM sham group for 35 days. CONCLUSION DM prolongs the pain-related behavior caused by NP. The prolonged inflammation and nerve regeneration could elucidate the pathogenesis of continuous pain of radiculopathy initiated by LDH. LEVEL OF EVIDENCE N /A.
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Abstract
We compared patterns of intraepidermal nerve fibers and mechanoreceptors from affected and unaffected plantar skin from patients with pachyonychia congenita (PC) and control subjects. Plantar biopsies from 10 genetically confirmed patients with PC (with a mutation in KRT6A) were performed at the ball of the foot (affected skin) and the arch (unaffected) and were compared to biopsies from corresponding locations in 10 control subjects. Tissue was processed to visualize intraepidermal nerve fibers (IENF) (PGP9.5), subsets of IENF (CGRP, substance P, tyrosine hydroxylase), myelinated nerve fiber (neurofilament H, NFH), blood vessels (CD31), Meissner corpuscles, and Merkel cells (MCs). Structures were quantified using stereology or validated quantification methods. We observed that PC-affected plantar skin had significantly lower sweat gland innervation (sweat gland nerve fiber density) and reduced numbers of Meissner corpuscles compared to PC-unaffected or anatomically matched control skin. In contrast, Merkel cell densities and blood vessel counts were higher in PC-affected skin compared to either control or PC-unaffected skin. There were no differences in myelinated nerve fiber densities, SP, or CGRP between the groups. Pressure pain thresholds in PC-affected skin were lower compared to PC-unaffected and anatomically matched control skin. Additionally, MC densities in callused plantar skin from healthy runners with callus and one subject with a nonpainful palmoplantar keratoderma (AQP5 mutation) were similar to PC-unaffected and control skin consistent with callus alone not being sufficient to increase MC number. These findings suggest that alterations in PC extend beyond keratinocytes and may provide strategies to study neuropathic pain in PC.
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31
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Paik JJ, Mammen AL, Wigley FM, Shah AA, Hummers LK, Polydefkis M. Symptomatic and Electrodiagnostic Features of Peripheral Neuropathy in Scleroderma. Arthritis Care Res (Hoboken) 2017; 68:1150-7. [PMID: 26663579 DOI: 10.1002/acr.22818] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 11/16/2015] [Accepted: 12/08/2015] [Indexed: 01/05/2023]
Abstract
OBJECTIVE To determine the prevalence of peripheral neuropathy in scleroderma. METHODS The prevalence of length-dependent peripheral neuropathy was rigorously assessed using signs and symptoms of neuropathy derived from the Total Neuropathy Score (TNS), and standardized nerve conduction study (NCS). All subjects underwent TNS and NCS. Those who were symptomatic or had NCS evidence of peripheral neuropathy underwent laboratory evaluation for secondary causes of neuropathy. RESULTS A total of 130 subjects were approached for participation and 60 enrolled. Of the 60 subjects, 50 (83.3%) were female and 37 (61.7%) were of the limited cutaneous subtype. The mean ± SD age was 55 ± 11.1 years, and mean ± SD disease duration was 15.3 ± 10.1 years. A total of 17 of 60 (28%) had evidence of a peripheral neuropathy as defined by the presence of neuropathic symptoms on the TNS (12 of 60) and/or electrophysiologic evidence of neuropathy (5 subjects with neuropathic symptoms and 5 without neuropathic symptoms). Subjects with neuropathy were more likely to be male (60% versus 40%; P = 0.02), African American (41% versus 4.6%; P = 0.001), have diabetes mellitus (17.7% versus 0%; P = 0.02), have limited cutaneous scleroderma (82.3% versus 53.5%; P = 0.04), and have anti-U1 RNP antibodies (23.5% versus 0%; P = 0.009) than those without neuropathy. A potential nonscleroderma etiology for the peripheral neuropathy such as diabetes mellitus was found in 82.3% (14 of 17) of subjects with neuropathy. CONCLUSION While symptoms or objective evidence of peripheral neuropathy are common among patients with scleroderma, the cause may often be attributed to comorbid nonscleroderma-related conditions.
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Affiliation(s)
- Julie J Paik
- Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Andrew L Mammen
- National Institute of Arthritis and Musculoskeletal and Skin Diseases/NIH, Bethesda, Maryland, and Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Ami A Shah
- Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Laura K Hummers
- Johns Hopkins University School of Medicine, Baltimore, Maryland
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Niemi JP, Filous AR, DeFrancesco A, Lindborg JA, Malhotra NA, Wilson GN, Zhou B, Crish SD, Zigmond RE. Injury-induced gp130 cytokine signaling in peripheral ganglia is reduced in diabetes mellitus. Exp Neurol 2017. [PMID: 28645526 DOI: 10.1016/j.expneurol.2017.06.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Neuropathy is a major diabetic complication. While the mechanism of this neuropathy is not well understood, it is believed to result in part from deficient nerve regeneration. Work from our laboratory established that gp130 family of cytokines are induced in animals after axonal injury and are involved in the induction of regeneration-associated genes (RAGs) and in the conditioning lesion response. Here, we examine whether a reduction of cytokine signaling occurs in diabetes. Streptozotocin (STZ) was used to destroy pancreatic β cells, leading to chronic hyperglycemia. Mice were injected with either low doses of STZ (5×60mg/kg) or a single high dose (1×200mg/kg) and examined after three or one month, respectively. Both low and high dose STZ treatment resulted in sustained hyperglycemia and functional deficits associated with the presence of both sensory and autonomic neuropathy. Diabetic mice displayed significantly reduced intraepidermal nerve fiber density and sudomotor function. Furthermore, low and high dose diabetic mice showed significantly reduced tactile touch sensation measured with Von Frey monofilaments. To look at the regenerative and injury-induced responses in diabetic mice, neurons in both superior cervical ganglia (SCG) and the 4th and 5th lumbar dorsal root ganglia (DRG) were unilaterally axotomized. Both high and low dose diabetic mice displayed significantly less axonal regeneration in the sciatic nerve, when measured in vivo, 48h after crush injury. Significantly reduced induction of two gp130 cytokines, leukemia inhibitory factor and interleukin-6, occurred in diabetic animals in SCG 6h after injury compared to controls. Injury-induced expression of interleukin-6 was also found to be significantly reduced in the DRG at 6h after injury in low and high dose diabetic mice. These effects were accompanied by reduced phosphorylation of signal transducer and activator of transcription 3 (STAT3), a downstream effector of the gp130 signaling pathway. We also found decreased induction of several gp130-dependent RAGs, including galanin and vasoactive intestinal peptide. Together, these data suggest a novel mechanism for the decreased response of diabetic sympathetic and sensory neurons to injury.
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Affiliation(s)
- Jon P Niemi
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Angela R Filous
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Alicia DeFrancesco
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Jane A Lindborg
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Nisha A Malhotra
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Gina N Wilson
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA; School of Biomedical Sciences, Kent State University, Kent, OH, USA
| | - Bowen Zhou
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| | - Samuel D Crish
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, OH, USA
| | - Richard E Zigmond
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA.
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Peric S, Bozovic I, Bjelica B, Berisavac I, Stojiljkovic O, Basta I, Beslac-Bumbasirevic L, Rakocevic-Stojanovic V, Lavrnic D, Stevic Z. Diabetes mellitus may affect short-term outcome of Guillain-Barré syndrome. J Peripher Nerv Syst 2017; 22:127-130. [DOI: 10.1111/jns.12206] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Revised: 02/01/2017] [Accepted: 02/02/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Stojan Peric
- Neurology Clinic, Clinical Center of Serbia, School of Medicine; University of Belgrade; Belgrade Serbia
| | - Ivo Bozovic
- Neurology Clinic, Clinical Center of Serbia, School of Medicine; University of Belgrade; Belgrade Serbia
| | - Bogdan Bjelica
- Neurology Clinic, Clinical Center of Serbia, School of Medicine; University of Belgrade; Belgrade Serbia
| | - Ivana Berisavac
- Neurology Clinic, Clinical Center of Serbia, School of Medicine; University of Belgrade; Belgrade Serbia
| | - Olivera Stojiljkovic
- Neurology Clinic, Clinical Center of Serbia, School of Medicine; University of Belgrade; Belgrade Serbia
| | - Ivana Basta
- Neurology Clinic, Clinical Center of Serbia, School of Medicine; University of Belgrade; Belgrade Serbia
| | | | | | - Dragana Lavrnic
- Neurology Clinic, Clinical Center of Serbia, School of Medicine; University of Belgrade; Belgrade Serbia
| | - Zorica Stevic
- Neurology Clinic, Clinical Center of Serbia, School of Medicine; University of Belgrade; Belgrade Serbia
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Thomsen NOB, Andersson GS, Björk J, Dahlin LB. Neurophysiological recovery 5 years after carpal tunnel release in patients with diabetes. Muscle Nerve 2017; 56:E59-E64. [PMID: 28241376 DOI: 10.1002/mus.25633] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 02/18/2017] [Accepted: 02/22/2017] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The long-term results of neurophysiological recovery after carpal tunnel release in patients with diabetes have not been studied. METHODS Thirty-five patients with diabetes and carpal tunnel syndrome (CTS) were matched with 31 patients without diabetes who had idiopathic CTS, and 27 and 30 patients, respectively, participated in this follow-up study. Nerve conduction results at 5 years were compared with previously published results at baseline and 1 year. RESULTS Significant neurophysiological improvement continued from 1 to 5 years after carpal tunnel release for patients with and without diabetes. However, wrist-palm sensory conduction velocity was still abnormal for 85% and 43% of patients with and without diabetes, respectively. Although diabetes had an impact on 4 of 10 measured neurophysiological parameters, the influence of peripheral neuropathy seemed insignificant. DISCUSSION After carpal tunnel release, significant long-term neurophysiological improvement is possible for patients with diabetes, and it is not influenced by the presence of peripheral neuropathy. Muscle Nerve 56: E59-E64, 2017.
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Affiliation(s)
- Niels O B Thomsen
- Department of Hand Surgery, Skåne University Hospital, SE-205 02, Malmö, Sweden.,Department of Translational Medicine, Hand Surgery, Lund University, Malmö, Sweden
| | - Gert S Andersson
- Department of Clinical Neurophysiology, Skåne University Hospital, Lund, Sweden.,Department of Clinical Sciences Lund, Clinical Neurophysiology, Lund University, Lund, Sweden
| | - Jonas Björk
- Division of Occupational and Environmental Medicine, Lund University, Lund, Sweden
| | - Lars B Dahlin
- Department of Hand Surgery, Skåne University Hospital, SE-205 02, Malmö, Sweden.,Department of Translational Medicine, Hand Surgery, Lund University, Malmö, Sweden
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Zhong W, Yang M, Zhang W, Visocchi M, Chen X, Liao C. Improved neural microcirculation and regeneration after peripheral nerve decompression in DPN rats. Neurol Res 2017; 39:285-291. [PMID: 28290778 DOI: 10.1080/01616412.2017.1297557] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OBJECTIVE Recently, neural microcirculation and regeneration were regarded as critical factors in diabetic peripheral neuropathy (DPN) improvement. In the present study, we explored the cytological and molecular mechanisms how peripheral nerve decompression impaired nerve injury. METHODS Forty-five male SD rats were established as the DPN model. HE staining was used to observe the morphology and distribution of microvessels. Transmission electron microscopy was applied to observe the morphology and distribution of Schwann cells. Immunohistochemical staining was performed to measure nerve growth factor (NGF), tyrosine kinase receptor A (TrkA) and growth-associated protein 43 (GAP-43) in the distal sciatic nerve. RESULTS Distribution of microvessels and Schwann cells decreased in the DPN group (p < 0.05). NGF, TrkA and GAP-43 also decreased significantly in the DPN group (p < 0.05). NGF, TrkA, GAP-43 and distribution of microvessels and Schwann cells increased in the decompressed group (p < 0.05). DISCUSSION In DPN rats, after nerves are compressed, microcirculation disturbance and hypoxia ischemia will happen, which cause decreased expression of NGF, TrkA and GAP-43. Finally, the self-healing function of compressed nerves is impacted. Conversely, nerve decompression can improve neural microcirculation and regeneration and change the former pathological process.
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Affiliation(s)
- Wenxiang Zhong
- a Department of Neurosurgery , Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Min Yang
- a Department of Neurosurgery , Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Wenchuan Zhang
- a Department of Neurosurgery , Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai , China
| | - Massimiliano Visocchi
- b Institute of Neurosurgery, Policlinico Gemelli, Catholic University School of Medicine , Rome , Italy
| | - Xiangjun Chen
- c Department of Neurology , Huashan Hospital, Affiliated to Fudan University , Shanghai , China
| | - Chenlong Liao
- a Department of Neurosurgery , Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine , Shanghai , China
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Gonçalves NP, Vægter CB, Andersen H, Østergaard L, Calcutt NA, Jensen TS. Schwann cell interactions with axons and microvessels in diabetic neuropathy. Nat Rev Neurol 2017; 13:135-147. [PMID: 28134254 DOI: 10.1038/nrneurol.2016.201] [Citation(s) in RCA: 163] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The prevalence of diabetes worldwide is at pandemic levels, with the number of patients increasing by 5% annually. The most common complication of diabetes is peripheral neuropathy, which has a prevalence as high as 50% and is characterized by damage to neurons, Schwann cells and blood vessels within the nerve. The pathogenic mechanisms of diabetic neuropathy remain poorly understood, impeding the development of targeted therapies to treat nerve degeneration and its most disruptive consequences of sensory loss and neuropathic pain. Involvement of Schwann cells has long been proposed, and new research techniques are beginning to unravel a complex interplay between these cells, axons and microvessels that is compromised during the development of diabetic neuropathy. In this Review, we discuss the evolving concept of Schwannopathy as an integral factor in the pathogenesis of diabetic neuropathy, and how disruption of the interactions between Schwann cells, axons and microvessels contribute to the disease.
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Affiliation(s)
- Nádia P Gonçalves
- The International Diabetic Neuropathy Consortium (IDNC), Aarhus University, Nørrebrogade, 8000 Aarhus C, Denmark
| | - Christian B Vægter
- Danish Research Institute of Translational Neuroscience DANDRITE, Nordic-EMBL Partnership, Department of Biomedicine, Aarhus University, Ole Worms Alle 3, 8000 Aarhus C, Denmark
| | - Henning Andersen
- Department of Neurology, Danish Pain Research Center and IDNC, Aarhus University Hospital, Nørrebrogade, 8000 Aarhus C, Denmark
| | - Leif Østergaard
- Department of Neuroradiology and Center for Functionally Integrative Neuroscience, Aarhus University Hospital, Nørrebrogade, 8000 Aarhus C, Denmark
| | - Nigel A Calcutt
- Department of Pathology, University of California San Diego, Gilman Drive, La Jolla, California 92093, USA
| | - Troels S Jensen
- Department of Neurology, Danish Pain Research Center and IDNC, Aarhus University Hospital, Nørrebrogade, 8000 Aarhus C, Denmark
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Zhao CC, Wang CF, Li WP, Lin Y, Tang QL, Feng JF, Mao Q, Gao GY, Jiang JY. Mild Hypothermia Promotes Pericontusion Neuronal Sprouting via Suppressing Suppressor of Cytokine Signaling 3 Expression after Moderate Traumatic Brain Injury. J Neurotrauma 2017; 34:1636-1644. [PMID: 27923323 DOI: 10.1089/neu.2016.4759] [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] [Indexed: 12/22/2022] Open
Abstract
Mild therapeutic hypothermia is a candidate for the treatment of traumatic brain injury (TBI). However, the role of mild hypothermia in neuronal sprouting after TBI remains obscure. We used a fluid percussion injury (FPI) model to assess the effect of mild hypothermia on pericontusion neuronal sprouting after TBI in rats. Male Sprague-Dawley rats underwent FPI or sham surgery, followed by mild hypothermia treatment (33°C) or normothermia treatment (37°C) for 3 h. All the rats were euthanized at 7 days after FPI. Neuronal sprouting that was confirmed by an increase in growth associated protein-43 (GAP-43) expression was evaluated using immunofluorescence and Western blot assays. The expression levels of several intrinsic and extrinsic sprouting-associated genes such as neurite outgrowth inhibitor A (NogoA), phosphatase and tensin homolog (PTEN), and suppressor of cytokine signaling 3 (SOCS3) were analyzed by quantitative real-time polymerase chain reaction (RT-PCR). Our results revealed that mild hypothermia significantly increased the expression level of GAP-43 and dramatically suppressed the expression level of interleukin-6 (IL-6) and SOCS3 at 7 days after FPI in the ipsilateral cortex compared with that of the normothermia TBI group. These data suggest that post-traumatic mild hypothermia promotes pericontusion neuronal sprouting after TBI. Moreover, the mechanism of hypothermia-induced neuronal sprouting might be partially associated with decreased levels of SOCS3.
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Affiliation(s)
- Cheng-Cheng Zhao
- 1 Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University , Shanghai Institute of Head Trauma, Shanghai, People's Republic of China
| | - Chuan-Fang Wang
- 1 Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University , Shanghai Institute of Head Trauma, Shanghai, People's Republic of China
| | - Wei-Ping Li
- 2 Department of Neurosurgery, Shenzhen Second People's Hospital, Shenzhen University , Shenzhen, Guangdong, People's Republic of China
| | - Yong Lin
- 1 Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University , Shanghai Institute of Head Trauma, Shanghai, People's Republic of China
| | - Qi-Lin Tang
- 1 Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University , Shanghai Institute of Head Trauma, Shanghai, People's Republic of China
| | - Jun-Feng Feng
- 1 Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University , Shanghai Institute of Head Trauma, Shanghai, People's Republic of China
| | - Qing Mao
- 1 Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University , Shanghai Institute of Head Trauma, Shanghai, People's Republic of China
| | - Guo-Yi Gao
- 1 Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University , Shanghai Institute of Head Trauma, Shanghai, People's Republic of China
| | - Ji-Yao Jiang
- 1 Department of Neurosurgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University , Shanghai Institute of Head Trauma, Shanghai, People's Republic of China
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Repeatability of Measuring Corneal Nerve Migration Rate in Individuals With and Without Diabetes. Cornea 2016; 35:1355-61. [DOI: 10.1097/ico.0000000000000913] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Van Acker N, Ragé M, Vermeirsch H, Schrijvers D, Nuydens R, Byttebier G, Timmers M, De Schepper S, Streffer J, Andries L, Plaghki L, Cras P, Meert T. NRP-1 Receptor Expression Mismatch in Skin of Subjects with Experimental and Diabetic Small Fiber Neuropathy. PLoS One 2016; 11:e0161441. [PMID: 27598321 PMCID: PMC5012683 DOI: 10.1371/journal.pone.0161441] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 08/07/2016] [Indexed: 12/27/2022] Open
Abstract
The in vivo cutaneous nerve regeneration model using capsaicin is applied extensively to study the regenerative mechanisms and therapeutic efficacy of disease modifying molecules for small fiber neuropathy (SFN). Since mismatches between functional and morphological nerve fiber recovery are described for this model, we aimed at determining the capability of the capsaicin model to truly mimic the morphological manifestations of SFN in diabetes. As nerve and blood vessel growth and regenerative capacities are defective in diabetes, we focused on studying the key regulator of these processes, the neuropilin-1 (NRP-1)/semaphorin pathway. This led us to the evaluation of NRP-1 receptor expression in epidermis and dermis of subjects presenting experimentally induced small fiber neuropathy, diabetic polyneuropathy and of diabetic subjects without clinical signs of small fiber neuropathy. The NRP-1 receptor was co-stained with CD31 vessel-marker using immunofluorescence and analyzed with Definiens® technology. This study indicates that capsaicin application results in significant loss of epidermal NRP-1 receptor expression, whereas diabetic subjects presenting small fiber neuropathy show full epidermal NRP-1 expression in contrast to the basal expression pattern seen in healthy controls. Capsaicin induced a decrease in dermal non-vascular NRP-1 receptor expression which did not appear in diabetic polyneuropathy. We can conclude that the capsaicin model does not mimic diabetic neuropathy related changes for cutaneous NRP-1 receptor expression. In addition, our data suggest that NRP-1 might play an important role in epidermal nerve fiber loss and/or defective regeneration and that NRP-1 receptor could change the epidermal environment to a nerve fiber repellant bed possibly through Sem3A in diabetes.
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Affiliation(s)
- Nathalie Van Acker
- Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- HistoGeneX NV, Antwerp, Belgium
- * E-mail:
| | - Michael Ragé
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | | | | | - Rony Nuydens
- Janssen Research and Development, Janssen Pharmaceutics NV, Beerse, Belgium
| | - Geert Byttebier
- Janssen Research and Development, Janssen Pharmaceutics NV, Beerse, Belgium
| | - Maarten Timmers
- Janssen Research and Development, Janssen Pharmaceutics NV, Beerse, Belgium
- Reference Center for Biological Markers of Dementia (BIODEM), Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | | | - Johannes Streffer
- Janssen Research and Development, Janssen Pharmaceutics NV, Beerse, Belgium
- Reference Center for Biological Markers of Dementia (BIODEM), Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
| | | | - Léon Plaghki
- Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - Patrick Cras
- Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp, Belgium
- Department of Neurology, Antwerp University Hospital, Born Bunge Institute, University of Antwerp, Antwerp, Belgium
| | - Theo Meert
- Janssen Research and Development, Janssen Pharmaceutics NV, Beerse, Belgium
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Mangus LM, Dorsey JL, Weinberg RL, Ebenezer GJ, Hauer P, Laast VA, Mankowski JL. Tracking Epidermal Nerve Fiber Changes in Asian Macaques: Tools and Techniques for Quantitative Assessment. Toxicol Pathol 2016; 44:904-12. [PMID: 27235324 PMCID: PMC4965306 DOI: 10.1177/0192623316650286] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Quantitative assessment of epidermal nerve fibers (ENFs) has become a widely used clinical tool for the diagnosis of small fiber neuropathies such as diabetic neuropathy and human immunodeficiency virus-associated sensory neuropathy (HIV-SN). To model and investigate the pathogenesis of HIV-SN using simian immunodeficiency virus (SIV)-infected Asian macaques, we adapted the skin biopsy and immunostaining techniques currently employed in human patients and then developed two unbiased image analysis techniques for quantifying ENF in macaque footpad skin. This report provides detailed descriptions of these tools and techniques for ENF assessment in macaques and outlines important experimental considerations that we have identified in the course of our long-term studies. Although initially developed for studies of HIV-SN in the SIV-infected macaque model, these methods could be readily translated to a range of studies involving peripheral nerve degeneration and neurotoxicity in nonhuman primates as well as preclinical investigations of agents aimed at neuroprotection and regeneration.
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Affiliation(s)
- Lisa M Mangus
- Department of Molecular and Comparative Pathobiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jamie L Dorsey
- Department of Molecular and Comparative Pathobiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Rachel L Weinberg
- Department of Molecular and Comparative Pathobiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Gigi J Ebenezer
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Peter Hauer
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA Current Affiliation: Department of Neurology, School of Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Victoria A Laast
- Department of Molecular and Comparative Pathobiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA Current Affiliation: Covance Pharmaceutical Research and Development (Shanghai) Co. Ltd., Shanghai, China
| | - Joseph L Mankowski
- Department of Molecular and Comparative Pathobiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA Department of Pathology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
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Wang L, Chopp M, Szalad A, Lu X, Jia L, Lu M, Zhang RL, Zhang ZG. Tadalafil Promotes the Recovery of Peripheral Neuropathy in Type II Diabetic Mice. PLoS One 2016; 11:e0159665. [PMID: 27438594 PMCID: PMC4954704 DOI: 10.1371/journal.pone.0159665] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 07/05/2016] [Indexed: 12/16/2022] Open
Abstract
We previously demonstrated that treatment of diabetic peripheral neuropathy with the short (4 hours) half-life phosphodiesterase 5 (PDE5) inhibitor, sildenafil, improved functional outcome in diabetic db/db mice. To further examine the effect of PDE5 inhibition on diabetic peripheral neuropathy, we investigated the effect of another potent PDE5 inhibitor, tadalafil, on diabetic peripheral neuropathy. Tadalafil is pharmacokinetically distinct from sildenafil and has a longer half-life (17+hours) than sildenafil. Diabetic mice (BKS.Cg-m+/+Leprdb/J, db/db) at age 20 weeks were treated with tadalafil every 48 hours for 8 consecutive weeks. Compared with diabetic mice treated with saline, tadalafil treatment significantly improved motor and sensory conduction velocities in the sciatic nerve and peripheral thermal sensitivity. Tadalafil treatment also markedly increased local blood flow and the density of FITC-dextran perfused vessels in the sciatic nerve concomitantly with increased intraepidermal nerve fiber density. Moreover, tadalafil reversed the diabetes-induced reductions of axon diameter and myelin thickness and reversed the diabetes-induced increased g-ratio in the sciatic nerve. Furthermore, tadalafil enhanced diabetes-reduced nerve growth factor (NGF) and platelet-derived growth factor-C (PDGF-C) protein levels in diabetic sciatic nerve tissue. The present study demonstrates that tadalafil increases regional blood flow in the sciatic nerve tissue, which may contribute to the improvement of peripheral nerve function and the amelioration of diabetic peripheral neuropathy.
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Affiliation(s)
- Lei Wang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
- * E-mail:
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
- Department of Physics, Oakland University, Rochester, Michigan, 48309, United States of America
| | - Alexandra Szalad
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - XueRong Lu
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - LongFei Jia
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - Mei Lu
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - Rui Lan Zhang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
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Havrdova T, Boucek P, Saudek F, Voska L, Lodererova A, Üçeyler N, Vondrova H, Skibova J, Lipar K, Sommer C. Severe Epidermal Nerve Fiber Loss in Diabetic Neuropathy Is Not Reversed by Long-Term Normoglycemia After Simultaneous Pancreas and Kidney Transplantation. Am J Transplant 2016; 16:2196-201. [PMID: 26751140 DOI: 10.1111/ajt.13715] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 12/16/2015] [Accepted: 01/02/2016] [Indexed: 01/25/2023]
Abstract
Whether nerve fiber loss, a prominent feature of advanced diabetic neuropathy, can be reversed by reestablishment of normal glucose control remains questionable. We present 8-year follow-up data on epidermal nerve fiber (ENF) density and neurological function in patients with type 1 diabetes after simultaneous pancreas and kidney transplantation (SPK) with long-term normoglycemia. Distal thigh skin biopsies with ENF counts, vibration perception thresholds (VPTs), autonomic function testing (AFT) and electrophysiological examinations were performed at time of SPK and 2.5 and 8 years after SPK in 12 patients with type 1 diabetes. In comparison to controls, baseline ENF density, VPT and AFT results of patients indicated severe neuropathy. At follow-up, all SPK recipients were insulin independent with excellent glycemic control and kidney graft function; however, the severe ENF depletion present at baseline had not improved, with total ENF absence in 11 patients at 8-year follow-up. Similarly, no amelioration occurred in the VPT and AFT results. Numerical improvement was seen in some electrophysiological parameters; however, statistical significance was achieved only in median motor nerve conduction velocity. ENF loss and functional deficits in advanced diabetic peripheral neuropathy are rarely reversible, even by long-term normoglycemia, which underscores the importance of neuropathy prevention by early optimal glycemic control.
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Affiliation(s)
- T Havrdova
- Diabetes and Transplant Centers, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - P Boucek
- Diabetes and Transplant Centers, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - F Saudek
- Diabetes and Transplant Centers, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - L Voska
- Diabetes and Transplant Centers, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - A Lodererova
- Diabetes and Transplant Centers, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - N Üçeyler
- Department of Neurology, University of Würzburg, Würzburg, Germany
| | - H Vondrova
- Department of Neurology, Thomayer Hospital, Prague, Czech Republic
| | - J Skibova
- Diabetes and Transplant Centers, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - K Lipar
- Diabetes and Transplant Centers, Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - C Sommer
- Department of Neurology, University of Würzburg, Würzburg, Germany
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Khoshnoodi MA, Ebenezer GJ, Polydefkis M. Epidermal innervation as a tool to study human axonal regeneration and disease progression. Exp Neurol 2016; 287:358-364. [PMID: 27317299 DOI: 10.1016/j.expneurol.2016.06.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/10/2016] [Accepted: 06/13/2016] [Indexed: 01/14/2023]
Affiliation(s)
- Mohammad A Khoshnoodi
- Neurology, Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Meyer 5-119, Baltimore, MD 21287, USA.
| | - Gigi J Ebenezer
- Neurology, Cutaneous Nerve Laboratory, Johns Hopkins University School of Medicine, The John G Rangos Building, 855 N. Wolfe Street, room 440, Baltimore, MD 21205, USA.
| | - Michael Polydefkis
- Neurology, Johns Hopkins University School of Medicine, Cutaneous Nerve Laboratory, Johns Hopkins Bayview EMG Laboratory, The John G Rangos Building, 855 N. Wolfe Street, room 435, Baltimore, MD 21205, USA.
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Persistent Peripheral Nervous System Damage in Simian Immunodeficiency Virus-Infected Macaques Receiving Antiretroviral Therapy. J Neuropathol Exp Neurol 2016; 74:1053-60. [PMID: 26426267 DOI: 10.1097/nen.0000000000000249] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Human immunodeficiency virus (HIV)-induced peripheral neuropathy is the most common neurologic complication associated with HIV infection. In addition to virus-mediated injury of the peripheral nervous system (PNS), treatment of HIV infection with combination antiretroviral therapy (cART) may induce toxic neuropathy as a side effect. Antiretroviral toxic neuropathy is clinically indistinguishable from the sensory neuropathy induced by HIV; in some patients, these 2 processes are likely superimposed. To study these intercurrent PNS disease processes, we first established a simian immunodeficiency virus (SIV)/pigtailed macaque model in which more than 90% of animals developed PNS changes closely resembling those seen in HIV-infected individuals with distal sensory neuropathy. To determine whether cART alters the progression of SIV-induced PNS damage, dorsal root ganglia and epidermal nerve fibers were evaluated in SIV-infected macaques after long-term suppressive cART. Although cART effectively suppressed SIV replication and reduced macrophage activation in the dorsal root ganglia, PGP 9.5 immunostaining and measurements of epidermal nerve fibers in the plantar surface of the feet of treated SIV-infected macaques clearly showed that cART did not normalize epidermal nerve fiber density. These findings illustrate that significant PNS damage persists in SIV-infected macaques on suppressive cART.
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Abstract
Diabetic neuropathy is a dying back neurodegenerative disease of the peripheral nervous system where mitochondrial dysfunction has been implicated as an etiological factor. Diabetes (type 1 or type 2) invokes an elevation of intracellular glucose concentration simultaneously with impaired growth factor support by insulin, and this dual alteration triggers a maladaptation in metabolism of adult sensory neurons. The energy sensing pathway comprising the AMP-activated protein kinase (AMPK)/sirtuin (SIRT)/peroxisome proliferator-activated receptor-γ coactivator α (PGC-1α) signaling axis is the target of these damaging changes in nutrient levels, e.g., induction of nutrient stress, and loss of insulin-dependent growth factor support and instigates an aberrant metabolic phenotype characterized by a suppression of mitochondrial oxidative phosphorylation and shift to anaerobic glycolysis. There is discussion of how this loss of mitochondrial function and transition to overreliance on glycolysis contributes to the diminishment of collateral sprouting and axon regeneration in diabetic neuropathy in the context of the highly energy-consuming nerve growth cone.
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Affiliation(s)
- Paul Fernyhough
- Division of Neurodegenerative Disorders, St Boniface Hospital Research Centre, R4046-351 Taché Ave, Winnipeg, Manitoba, R2H 2A6, Canada.
- Department of Pharmacology & Therapeutics, University of Manitoba, Winnipeg, MB, R3E 0T6, Canada.
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Ward NH, Wainwright DJ. Outcomes research: Mandibular fractures in the diabetic population. J Craniomaxillofac Surg 2015; 44:763-9. [PMID: 27160339 DOI: 10.1016/j.jcms.2015.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 09/18/2015] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE The study aimed to examine the management and outcomes of mandibular fractures in patients with diabetes mellitus by examining the injury modalities, treatment methods, and complications. METHODS The study conducted was a retrospective case review of patients admitted to Memorial Hermann Hospital from 2007 to 2011 with diagnoses of diabetes mellitus and mandibular fracture. The electronic medical records were reviewed for patient demographics, injury data, surgery methodology, treatment variables, and complications. RESULTS Out of the 34 diabetic patients, the average age was 52 with the majority of the fractures being the result of falls, 12 (35.3%). Of the 63 total fractures, 24 (38.1%) fractures were repaired through closed reduction and 39 (61.9%) fractures required open reduction with internal fixation. 17 (50.0%) patients had at least one complication following mandibular fracture repair. The most common complications in this sample population included nerve injury, 7 (20.6%), infection, 7 (20.6%), wound dehiscence with or without hardware exposure, 6 (17.7%), and malocclusion, 5 (14.7%). CONCLUSION When compared to the limited published data our findings imply that diabetic patients with mandibular fractures present as an older population than commonly seen with mandibular fractures and suggest a higher overall rate of complications.
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Affiliation(s)
- Norman H Ward
- Department of Surgery: Division of Plastic & Reconstructive Surgery, The University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA.
| | - David J Wainwright
- Department of Surgery: Division of Plastic & Reconstructive Surgery, The University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA
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Single-fiber electromyography of facial and limb muscles in diabetic patients with or without neuropathy. J Clin Neurophysiol 2015; 31:450-5. [PMID: 25271685 DOI: 10.1097/wnp.0000000000000087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
PURPOSE In diabetic patients, single-fiber electromyography (SFEMG) is often abnormal in the limb muscles and is considered unreliable in diagnosis of synaptic disorders. We aimed to compare SFEMG abnormalities of frontalis muscle (FM) and extensor digitorum communis muscle in diabetic patients with neuropathy and without neuropathy. METHODS Stimulation SFEMG of FM and extensor digitorum communis muscle was performed in matched groups of 30 diabetic patients with neuropathy and 20 diabetic patients without neuropathy. RESULTS Single-fiber electromyography in the FM was abnormal in four diabetic patients with neuropathy and in one diabetic patient without neuropathy. Changes were rather mild. Extensor digitorum communis abnormalities were significantly more frequent-in 20 diabetic patients with neuropathy and in 7 diabetic patients without neuropathy (P < 0.001). We never observed a patient with abnormal FM but normal extensor digitorum communis muscle. CONCLUSIONS In diabetes, FM exhibits rare and quite mild SFEMG changes. This muscle may be suitable for SFEMG in diabetic patients with clinical suspicion for synaptic disorder.
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Merkies ISJ, Faber CG, Lauria G. Advances in diagnostics and outcome measures in peripheral neuropathies. Neurosci Lett 2015; 596:3-13. [PMID: 25703220 DOI: 10.1016/j.neulet.2015.02.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 02/05/2015] [Accepted: 02/17/2015] [Indexed: 12/13/2022]
Abstract
Peripheral neuropathies are a group of acquired and hereditary disorders presenting with different distribution and nerve fiber class involvement. The overall prevalence is 2.4%, increasing to 8% in the elderly population. However, the frequency may vary depending on the underlying pathogenesis and association with systemic diseases. Distal symmetric polyneuropathy is the most common form, though multiple mononeuropathies, non-length dependent neuropathy and small fiber neuropathy can occur and may require specific diagnostic tools. The use of uniform outcome measures in peripheral neuropathies is important to improve the quality of randomized controlled trials, enabling comparison between studies. Recent developments in defining the optimal set of outcome measures in inflammatory neuropathies may serve as an example for other conditions. Diagnostic and outcome measure advances in peripheral neuropathies will be discussed.
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Affiliation(s)
- Ingemar S J Merkies
- Department of Neurology, Spaarne Hospital, Hoofddorp, The Netherlands; Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Catharina G Faber
- Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Giuseppe Lauria
- 3rd Neurology Unit, IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy.
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50
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Wang L, Chopp M, Szalad A, Jia L, Lu X, Lu M, Zhang L, Zhang Y, Zhang R, Zhang ZG. Sildenafil ameliorates long term peripheral neuropathy in type II diabetic mice. PLoS One 2015; 10:e0118134. [PMID: 25689401 PMCID: PMC4331563 DOI: 10.1371/journal.pone.0118134] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 01/07/2015] [Indexed: 12/22/2022] Open
Abstract
Diabetic peripheral neuropathy is a common complication of long-standing diabetes mellitus. To mimic clinical trials in which patients with diabetes enrolled have advanced peripheral neuropathy, we investigated the effect of sildenafil, a specific inhibitor of phosphodiesterase type 5 enzyme, on long term peripheral neuropathy in middle aged male mice with type II diabetes. Treatment of diabetic mice (BKS.Cg-m+/+Leprdb/J, db/db) at age 36 weeks with sildenafil significantly increased functional blood vessels and regional blood flow in the sciatic nerve, concurrently with augmentation of intra-epidermal nerve fiber density in the skin and myelinated axons in the sciatic nerve. Functional analysis showed that the sildenafil treatment considerably improved motor and sensory conduction velocities in the sciatic nerve and peripheral thermal stimulus sensitivity compared with the saline treatment. In vitro studies showed that mouse dermal endothelial cells (MDE) cultured under high glucose levels exhibited significant down regulation of angiopoietin 1 (Ang1) expression and reduction of capillary-like tube formation, which were completely reversed by sildenafil. In addition, incubation of dorsal root ganglia (DRG) neurons with conditioned medium harvested from MDE under high glucose levels suppressed neurite outgrowth, where as conditional medium harvested from MDE treated with sildenafil under high glucose levels did not inhibit neurite outgrowth of DRG neurons. Moreover, blockage of the Ang1 receptor, Tie2, with a neutralized antibody against Tie2 abolished the beneficial effect of sildenafil on tube formation and neurite outgrowth. Collectively, our data indicate that sildenafil has a therapeutic effect on long term peripheral neuropathy of middle aged diabetic mice and that improvement of neurovascular dysfunction by sildenafil likely contributes to the amelioration of nerve function. The Ang1/Tie2 signaling pathway may play an important role in these restorative processes.
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Affiliation(s)
- Lei Wang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
- * E-mail:
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
- Department of Physics, Oakland University, Rochester, Michigan, 48309, United States of America
| | - Alexandra Szalad
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - LongFei Jia
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - XueRong Lu
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - Mei Lu
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - Li Zhang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - Yi Zhang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - RuiLan Zhang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
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