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Barut EN, Engin S, Yasar YK, Sezen SF. Riluzole, a neuroprotective agent, preserves erectile function following bilateral cavernous nerve injury in male rats. Int J Impot Res 2024; 36:275-282. [PMID: 36788353 DOI: 10.1038/s41443-023-00680-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 02/01/2023] [Accepted: 02/03/2023] [Indexed: 02/16/2023]
Abstract
Neurogenic erectile dysfunction is a highly prevalent complication in men undergoing radical prostatectomy. The underlying mechanisms remain incompletely defined and the effective therapy has been limited. This study aimed to evaluate the protective effect of riluzole and the role of PKC β and excitatory amino acid transporters (EAATs) mediating this effect in a rat model of bilateral cavernous injury (BCNI). A total of 48 male Sprague-Dawley rats were divided into sham, BCNI (at 7, 15 days post-injury) and BCNI treated with riluzole (8 mg/kg/day) groups. Erectile function was measured as maximum intracavernosal pressure (mICP)/mean arterial pressure (MAP) and total ICP/MAP. Changes in protein expressions of phospho (p)-PKC β IIser660 and EAATs were analysed in penis and major pelvic ganglion with western blotting. BCNI decreased erectile function at 7 and 15 days post-injury (mICP/MAP at 4 V: 0.45 ± 0.06 vs 0.84 ± 0.07; 0.34 ± 0.04 vs 0.77 ± 0.04 respectively; p < 0.001) whereas riluzole treatment (for 15 days) preserved erectile function (mICP/MAP at 4 V: 0.62 ± 0.03 vs 0.34 ± 0.04; p < 0.01). The decline in the expression of p-PKC β IIser660 was observed in penis at 7 and 15 days post-injury (p = 0.0003, p = 0.0033), which was prevented by riluzole treatment for 15 days (p = 0.0464). While expressions of EAAT-1 and EAAT-2 decreased in major pelvic ganglion following BCNI (p = 0.0428, p = 0.002), riluzole treatment for 15 days prevented the decrease only in EAAT-2 expression (p = 0.0456). Riluzole improved erectile function via possibly interacting with PKC β II and glutamatergic pathways, as a potential therapeutic candidate for erectile dysfunction.
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Affiliation(s)
- Elif Nur Barut
- Karadeniz Technical University, Faculty of Pharmacy, Department of Pharmacology, Trabzon, Türkiye.
| | - Seckin Engin
- Karadeniz Technical University, Faculty of Pharmacy, Department of Pharmacology, Trabzon, Türkiye
| | - Yesim Kaya Yasar
- Karadeniz Technical University, Faculty of Pharmacy, Department of Pharmacology, Trabzon, Türkiye
- Karadeniz Technical University, Drug and Pharmaceutical Technology Application and Research Center, Trabzon, Türkiye
| | - Sena F Sezen
- Karadeniz Technical University, Faculty of Pharmacy, Department of Pharmacology, Trabzon, Türkiye
- Karadeniz Technical University, Drug and Pharmaceutical Technology Application and Research Center, Trabzon, Türkiye
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Pistritu DV, Vasiliniuc AC, Vasiliu A, Visinescu EF, Visoiu IE, Vizdei S, Martínez Anghel P, Tanca A, Bucur O, Liehn EA. Phospholipids, the Masters in the Shadows during Healing after Acute Myocardial Infarction. Int J Mol Sci 2023; 24:ijms24098360. [PMID: 37176067 PMCID: PMC10178977 DOI: 10.3390/ijms24098360] [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: 04/03/2023] [Revised: 05/02/2023] [Accepted: 05/03/2023] [Indexed: 05/15/2023] Open
Abstract
Phospholipids are major components of cell membranes with complex structures, high heterogeneity and critical biological functions and have been used since ancient times to treat cardiovascular disease. Their importance and role were shadowed by the difficulty or incomplete available research methodology to study their biological presence and functionality. This review focuses on the current knowledge about the roles of phospholipids in the pathophysiology and therapy of cardiovascular diseases, which have been increasingly recognized. Used in singular formulation or in inclusive combinations with current drugs, phospholipids proved their positive and valuable effects not only in the protection of myocardial tissue, inflammation and fibrosis but also in angiogenesis, coagulation or cardiac regeneration more frequently in animal models as well as in human pathology. Thus, while mainly neglected by the scientific community, phospholipids present negligible side effects and could represent an ideal target for future therapeutic strategies in healing myocardial infarction. Acknowledging and understanding their mechanisms of action could offer a new perspective into novel therapeutic strategies for patients suffering an acute myocardial infarction, reducing the burden and improving the general social and economic outcome.
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Affiliation(s)
- Dan-Valentin Pistritu
- Victor Babes' National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania
| | | | - Anda Vasiliu
- Victor Babes' National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania
| | - Elena-Florentina Visinescu
- Faculty of Human Medicine, Carol Davila University of Medicine and Pharmacy, 37 Dionisie Lupu Street, 020021 Bucharest, Romania
| | - Ioana-Elena Visoiu
- Faculty of Human Medicine, Carol Davila University of Medicine and Pharmacy, 37 Dionisie Lupu Street, 020021 Bucharest, Romania
| | - Smaranda Vizdei
- Faculty of Human Medicine, Carol Davila University of Medicine and Pharmacy, 37 Dionisie Lupu Street, 020021 Bucharest, Romania
| | - Paula Martínez Anghel
- Victor Babes' National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania
- Business Academy Aarhus, 30 Sønderhøj, 8260 Viby J, Denmark
| | - Antoanela Tanca
- Victor Babes' National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania
- Faculty of Human Medicine, Carol Davila University of Medicine and Pharmacy, 37 Dionisie Lupu Street, 020021 Bucharest, Romania
| | - Octavian Bucur
- Victor Babes' National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania
- Viron Molecular Medicine Institute, 201 Washington Street, Boston, MA 02108, USA
| | - Elisa Anamaria Liehn
- Victor Babes' National Institute of Pathology, 99-101 Splaiul Independentei, 050096 Bucharest, Romania
- Institute for Molecular Medicine, University of Southern Denmark, 25 J.B Winsløws Vej, 5230 Odense, Denmark
- National Heart Center Singapore, 5 Hospital Dr., Singapore 169609, Singapore
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Sen CK, Roy S, Khanna S. Diabetic Peripheral Neuropathy Associated with Foot Ulcer: One of a Kind. Antioxid Redox Signal 2023. [PMID: 35850520 DOI: 10.1089/ars.2022.0093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Significance: Diabetic peripheral neuropathy (DPN) associated with a diabetic foot ulcer (DFU) is likely to be complicated with critical factors such as biofilm infection and compromised skin barrier function of the diabetic skin. Repaired skin with a history of biofilm infection is known to be compromised in barrier function. Loss of barrier function is also observed in the oxidative stress affected diabetic and aged skin. Recent Advances: Loss of barrier function makes the skin prone to biofilm infection and cellulitis, which contributes to chronic inflammation and vasculopathy. Hyperglycemia favors biofilm formation as glucose lowering led to reduction in biofilm development. While vasculopathy limits oxygen supply, the O2 cost of inflammation is high increasing hypoxia severity. Critical Issues: The host nervous system can be inhabited by bacteria. Because electrical impulses are a part of microbial physiology, polymicrobial colonization of the host's neural circuit is likely to influence transmission of action potential. The identification of perineural apatite in diabetic patients with peripheral neuropathy suggests bacterial involvement. DPN starts in both feet at the same time. Future Directions: Pair-matched studies of DPN in the foot affected with DFU (i.e., DFU-DPN) compared with DPN in the without ulcer, and intact skin barrier function, are likely to provide critical insight that would help inform effective care strategies. This review characterizes DFU-DPN from a translational science point of view presenting a new paradigm that recognizes the current literature in the context of factors that are unique to DFU-DPN.
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Affiliation(s)
- Chandan K Sen
- Indiana Center for Regenerative Medicine & Engineering, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Sashwati Roy
- Indiana Center for Regenerative Medicine & Engineering, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Savita Khanna
- Indiana Center for Regenerative Medicine & Engineering, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA
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BHF177 Suppresses Diabetic Neuropathic Pain by Blocking PKC/CaMKII/ERK1/2/CREB Signaling Pathway through Activating GABAB Receptor. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:4661519. [DOI: 10.1155/2022/4661519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 01/15/2022] [Indexed: 11/19/2022]
Abstract
The gamma-aminobutyric acid type B (GABAB) receptor may participate in the development of diabetic neuropathic pain (DNP). BHF177 serves as a positive allosteric modulator of the GABAB receptor. In the current study, we sought to study the role of the BHF177-GABAB receptor in DNP and its underlying mechanism. Streptozotocin was adopted to induce a rat model of DNP, followed by determination of the paw withdrawal threshold (PWT), paw withdrawal latency (PWL), and glucose level. The effect of BHF177 on DNP by regulating the GABAB receptor in vivo was determined by the injection of BHF177 and/or CGP46381 (a GABAB receptor antagonist) into rat models of DNP. Hippocampal neuronal cells were isolated and cultured, and the neurons and DNP model rats were treated with activators of PKC (PMA), CaMKII (CaCl2), or ERK1/2 (EGF) to study the role of GABAB receptors in DNP via regulation of the NR2B-PKC-CaMKII-ERK-CREB pathway. BHF177 suppressed DNP symptoms by activating the GABAB receptors, as evidenced by increased PWT and PWL of DNP rats and the increased number of neurons expressing the GABAB receptor, but this effect was reversed by CGP46381 treatment. BHF177 treatment markedly repressed PKC, CaMKII, p-ERK1/2, and p-CREB expressions in the rat DNP model, but these suppressive effects were abrogated by treatments with PMA, CaCl2, or EGF treatment, respectively. To sum up, BHF177 suppresses DNP symptoms by blocking the PKC/CaMKII/ERK1/2/CREB signaling pathway to activate the GABAB receptors.
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Raghav A, Singh M, Jeong GB, Giri R, Agarwal S, Kala S. New horizons of biomaterials in treatment of nerve damage in diabetes mellitus: A translational prospective review. Front Endocrinol (Lausanne) 2022; 13:1036220. [PMID: 36387914 PMCID: PMC9647066 DOI: 10.3389/fendo.2022.1036220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 09/28/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Peripheral nerve injury is a serious concern that leads to loss of neuronal communication that impairs the quality of life and, in adverse conditions, causes permanent disability. The limited availability of autografts with associated demerits shifts the paradigm of researchers to use biomaterials as an alternative treatment approach to recover nerve damage. PURPOSE The purpose of this study is to explore the role of biomaterials in translational treatment approaches in diabetic neuropathy. STUDY DESIGN The present study is a prospective review study. METHODS Published literature on the role of biomaterials in therapeutics was searched for. RESULTS Biomaterials can be implemented with desired characteristics to overcome the problem of nerve regeneration. Biomaterials can be further exploited in the treatment of nerve damage especially associated with PDN. These can be modified, customized, and engineered as scaffolds with the potential of mimicking the extracellular matrix of nerve tissue along with axonal regeneration. Due to their beneficial biological deeds, they can expedite tissue repair and serve as carriers of cellular and pharmacological treatments. Therefore, the emerging research area of biomaterials-mediated treatment of nerve damage provides opportunities to explore them as translational biomedical treatment approaches. CONCLUSIONS Pre-clinical and clinical trials in this direction are needed to establish the effective role of several biomaterials in the treatment of other human diseases.
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Affiliation(s)
- Alok Raghav
- Multidisciplinary Research Unit, Department of Health Research, Ganesh Shankar Vidyarthi Memorial (GSVM) Medical College, Kanpur, India
- *Correspondence: Alok Raghav,
| | - Manish Singh
- Multidisciplinary Research Unit, Department of Health Research, Ganesh Shankar Vidyarthi Memorial (GSVM) Medical College, Kanpur, India
- Department of Neurosurgery, Ganesh Shankar Vidyarthi Memorial (GSVM) Medical College, Kanpur, India
| | - Goo-Bo Jeong
- Department of Anatomy and Cell Biology, College of Medicine, Gachon University, Incheon, South Korea
| | - Richa Giri
- Multidisciplinary Research Unit, Department of Health Research, Ganesh Shankar Vidyarthi Memorial (GSVM) Medical College, Kanpur, India
- Kamlapat Singhania (KPS) Institute of Medicine, Ganesh Shankar Vidyarthi Memorial (GSVM) Medical College, Kanpur, India
| | - Saurabh Agarwal
- Multidisciplinary Research Unit, Department of Health Research, Ganesh Shankar Vidyarthi Memorial (GSVM) Medical College, Kanpur, India
- Kamlapat Singhania (KPS) Institute of Medicine, Ganesh Shankar Vidyarthi Memorial (GSVM) Medical College, Kanpur, India
| | - Sanjay Kala
- Department of Surgery, Ganesh Shankar Vidyarthi Memorial (GSVM) Medical College, Kanpur, India
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Therapeutic Potential of Polyphenols in the Management of Diabetic Neuropathy. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2021; 2021:9940169. [PMID: 34093722 PMCID: PMC8137294 DOI: 10.1155/2021/9940169] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 04/27/2021] [Indexed: 12/12/2022]
Abstract
Diabetic neuropathy (DN) is a common and serious diabetes-associated complication that primarily takes place because of neuronal dysfunction in patients with diabetes. Use of current therapeutic agents in DN treatment is quite challenging because of their severe adverse effects. Therefore, there is an increased need of identifying new safe and effective therapeutic agents. DN complications are associated with poor glycemic control and metabolic imbalances, primarily oxidative stress (OS) and inflammation. Various mediators and signaling pathways such as glutamate pathway, activation of channels, trophic factors, inflammation, OS, advanced glycation end products, and polyol pathway have a significant contribution to the progression and pathogenesis of DN. It has been indicated that polyphenols have the potential to affect DN pathogenesis and could be used as potential alternative therapy. Several polyphenols including kolaviron, resveratrol, naringenin, quercetin, kaempferol, and curcumin have been administered in patients with DN. Furthermore, chlorogenic acid can provide protection against glutamate neurotoxicity via its hydrolysate, caffeoyl acid group, and caffeic acid through regulating the entry of calcium into neurons. Epigallocatechin-3-gallate treatment can protect motor neurons by regulating the glutamate level. It has been demonstrated that these polyphenols can be promising in combating DN-associated damaging pathways. In this article, we have summarized DN-associated metabolic pathways and clinical manifestations. Finally, we have also focused on the roles of polyphenols in the treatment of DN.
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Fan B, Chopp M, Zhang ZG, Liu XS. Emerging Roles of microRNAs as Biomarkers and Therapeutic Targets for Diabetic Neuropathy. Front Neurol 2020; 11:558758. [PMID: 33192992 PMCID: PMC7642849 DOI: 10.3389/fneur.2020.558758] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 09/16/2020] [Indexed: 12/12/2022] Open
Abstract
Diabetic neuropathy (DN) is the most prevalent chronic complication of diabetes mellitus. The exact pathophysiological mechanisms of DN are unclear; however, communication network dysfunction among axons, Schwann cells, and the microvascular endothelium likely play an important role in the development of DN. Mounting evidence suggests that microRNAs (miRNAs) act as messengers that facilitate intercellular communication and may contribute to the pathogenesis of DN. Deregulation of miRNAs is among the initial molecular alterations observed in diabetics. As such, miRNAs hold promise as biomarkers and therapeutic targets. In preclinical studies, miRNA-based treatment of DN has shown evidence of therapeutic potential. But this therapy has been hampered by miRNA instability, targeting specificity, and potential toxicities. Recent findings reveal that when packaged within extracellular vesicles, miRNAs are resistant to degradation, and their delivery efficiency and therapeutic potential is markedly enhanced. Here, we review the latest research progress on the roles of miRNAs as biomarkers and as potential clinical therapeutic targets in DN. We also discuss the promise of exosomal miRNAs as therapeutics and provide recommendations for future research on miRNA-based medicine.
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Affiliation(s)
- Baoyan Fan
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States.,Department of Physics, Oakland University, Rochester, MI, United States
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | - Xian Shuang Liu
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
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Singh R, Rao HK, Singh TG. Neuropathic pain in diabetes mellitus: Challenges and future trends. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.obmed.2020.100215] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Nebuloni CC, Máximo RDO, de Oliveira C, Alexandre TDS. Uncontrolled Diabetes as an Associated Factor with Dynapenia in Adults Aged 50 Years or Older: Sex Differences. J Gerontol A Biol Sci Med Sci 2020; 75:1191-1197. [PMID: 31665234 PMCID: PMC7243578 DOI: 10.1093/gerona/glz257] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Indexed: 12/25/2022] Open
Abstract
Background Epidemiological studies demonstrate an association between diabetes and low neuromuscular strength (NMS). However, none have grouped participants into nondiabetics (ND), undiagnosed diabetics (UDD), controlled diabetics (CD), and uncontrolled diabetics (UCD) or investigated what glycated hemoglobin levels (HbA1c) are associated with low NMS (dynapenia) by sex. Methods We analyzed the association between UDD, CD, and UCD and dynapenia, the extent to which the different groupings of these individuals modifies this association and the association between HbA1c levels and NMS, by sex, in a cross-sectional study involving 5,290 participants ≥50 years from the ELSA study. In the first two analyses, logistic regression models were used with dynapenia (grip strength <26 kg in men and <16 kg in women) as outcome and diabetes (ND, UDD, CD, and UCD) as exposure. Next, linear regression was performed with grip strength as the outcome, and the participants were classified based on HbA1c level as exposure. The models were adjusted by sociodemographic, behavioral, and clinical characteristics. Results Compared to ND, only UCD was associated with dynapenia (men OR = 2.37 95% CI 1.36–4.14; women OR = 1.67 95% CI 1.01–2.79). This association was less clear, particularly in women, when CD and UCD groups were merged. HbA1c ≥6.5% in men and ≥8.0% in women were associated with lower NMS. Conclusions UCD increases the chance of dynapenia in both sexes. The different groupings based on diabetes status modify the association between UCD and dynapenia. The threshold of HbA1c associated with reduced NMS is lower in men compared to women.
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Affiliation(s)
- Clarice Cavalero Nebuloni
- Gerontology Graduate Program, Federal University of Sao Carlos, Brazil.,Geriatrics and Gerontology Sector, Federal University of Sao Paulo, Brazil
| | | | - Cesar de Oliveira
- Department of Epidemiology and Public Health, University College London, UK
| | - Tiago da Silva Alexandre
- Gerontology Graduate Program, Federal University of Sao Carlos, Brazil.,Physical Therapy Graduate Program, Federal University of Sao Carlos, Sao Carlos, SP, Brazil.,Department of Epidemiology and Public Health, University College London, UK.,Gerontology Department, Federal University of Sao Carlos, Brazil
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Sodium nitrate preconditioning prevents progression of the neuropathic pain in streptozotocin-induced diabetes Wistar rats. J Diabetes Metab Disord 2020; 19:105-113. [PMID: 32550160 DOI: 10.1007/s40200-019-00481-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 12/17/2019] [Indexed: 12/14/2022]
Abstract
Purpose The purpose of the study was to evaluate the possible protective effects of low dose sodium nitrate preconditioning on the peripheral neuropathy in streptozotocin (STZ)-induced diabetic model. Methods Male Wistar rats were randomly divided into five groups: control (no intervention), control treated sodium nitrate (100 mg/L in drinking water), diabetic (no intervention), diabetic treated NPH insulin (2-4 U), and diabetic treated sodium nitrate (100 mg/L in drinking water). Diabetes was induced by intraperitoneal injection of STZ (60 mg/kg). All interventions were done for 60 days immediately following diabetes confirmation. Thermal and mechanical algesia thresholds were measured by means of hot-plate test, von Frey test, and tail-withdrawal test before the diabetic induction and after diabetes confirmation. At the end of the experiment, serum NOx level and serum insulin level were assessed. Blood glucose concentration and body weight have recorded at the base and duration of the experiment. Results Both hypoalgesia, hyperalgesia along with allodynia developed in diabetic rats. Significant alterations including, decrease in tail withdrawal latency (30th day), decreased mechanical threshold (60th day), and an increase in hot plate latency (61st day) were displayed in diabetic rats compared to control rats. Nitrate and insulin preconditioning produced protective effects against diabetes-induced peripheral neuropathy. Data analysis also showed a significant increase in glucose level as well as a considerable reduction in serum insulin and body weight of diabetic rats, which restored by both insulin and nitrate preconditioning. Conclusion Sodium nitrate preconditioning produces a protective effect in diabetic neuropathy, which may be mediated by its antihyperglycemic effects and increased serum insulin level.
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Naseri R, Farzaei F, Fakhri S, El-Senduny FF, Altouhamy M, Bahramsoltani R, Ebrahimi F, Rahimi R, Farzaei MH. Polyphenols for diabetes associated neuropathy: Pharmacological targets and clinical perspective. Daru 2019; 27:781-798. [PMID: 31352568 PMCID: PMC6895369 DOI: 10.1007/s40199-019-00289-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Accepted: 07/01/2019] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVES Diabetic neuropathy (DNP) is a widespread and debilitating complication with complex pathophysiology that is caused by neuronal dysfunction in diabetic patients. Conventional therapeutics for DNP are quite challenging due to their serious adverse effects. Hence, there is a need to investigate novel effective and safe options. The novelty of the present study was to provide available therapeutic approaches, emerging molecular mechanisms, signaling pathways and future directions of DNP as well as polyphenols' effect, which accordingly, give new insights for paving the way for novel treatments in DNP. EVIDENCE ACQUISITION A comprehensive review was done in electronic databases including Medline, PubMed, Web of Science, Scopus, national database (Irandoc and SID), and related articles regarding metabolic pathways on the pathogenesis of DNP as well as the polyphenols' effect. The keywords "diabetic neuropathy" and "diabetes mellitus" in the title/abstract and "polyphenol" in the whole text were used. Data were collected from inception until May 2019. RESULTS DNP complications is mostly related to a poor glycemic control and metabolic imbalances mainly inflammation and oxidative stress. Several signaling and molecular pathways play key roles in the pathogenesis and progression of DNP. Among natural entities, polyphenols are suggested as multi-target alternatives affecting most of these pathogenesis mechanisms in DNP. CONCLUSION The findings revealed novel pathogenicity signaling pathways of DNP and affirmed the auspicious role of polyphenols to tackle these destructive pathways in order to prevent, manage, and treat various diseases. Graphical Abstract .
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Affiliation(s)
- Rozita Naseri
- Faculty of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Fatemeh Farzaei
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Sajad Fakhri
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Fardous F El-Senduny
- Biochemistry division, Chemistry Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt
| | - Miram Altouhamy
- Biochemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Roodabeh Bahramsoltani
- Department of Pharmacy in Persian Medicine, School of Persian Medicine, Tehran University of Medical Sciences, Tehran, Iran
- PhytoPharmacology Interest Group (PPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Farnaz Ebrahimi
- Pharmacy students` research committee, School of pharmacy, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Roja Rahimi
- Department of Pharmacy in Persian Medicine, School of Persian Medicine, Tehran University of Medical Sciences, Tehran, Iran
- PhytoPharmacology Interest Group (PPIG), Universal Scientific Education and Research Network (USERN), Tehran, Iran
| | - Mohammad Hosein Farzaei
- Pharmaceutical Sciences Research Center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.
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Rojas DR, Tegeder I, Kuner R, Agarwal N. Hypoxia-inducible factor 1α protects peripheral sensory neurons from diabetic peripheral neuropathy by suppressing accumulation of reactive oxygen species. J Mol Med (Berl) 2018; 96:1395-1405. [PMID: 30361814 DOI: 10.1007/s00109-018-1707-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 10/11/2018] [Accepted: 10/16/2018] [Indexed: 12/11/2022]
Abstract
Diabetic peripheral neuropathy (DPN) is one of the most common diabetic complications. Mechanisms underlying nerve damage and sensory loss following metabolic dysfunction remain largely unclear. Recently, hyperglycemia-induced mitochondrial dysfunction and the generation of reactive oxygen species (ROS) have gained attention as possible mechanisms of organ damage in diabetes. Hypoxia-inducible factor 1 (HIF1α) is a key transcription factor activated by hypoxia, hyperglycemia, nitric oxide as well as ROS, suggesting a fundamental role in DPN susceptibility. We analyzed regulation of HIF1α in response to prolonged hyperglycemia. Genetically modified mutant mice, which conditionally lack HIF1α in peripheral sensory neurons (SNS-HIF1α-/-), were analyzed longitudinally up to 6 months in the streptozotocin (STZ) model of type1 diabetes. Behavioral measurements of sensitivity to thermal and mechanical stimuli, quantitative morphological analyses of intraepidermal nerve fiber density, measurements of ROS, ROS-induced cyclic GMP-dependent protein kinase 1α (PKG1α), and levels of vascular endothelial growth factor (VEGF) in sensory neurons in vivo were undertaken over several months post-STZ injections to delineate the role of HIF1α in DPN. Longitudinal behavioral and morphological analyses at 5, 13, and 24 weeks post-STZ treatment revealed that SNS-HIF1α-/- developed stronger hyperglycemia-evoked losses of peripheral nociceptive sensory axons associated with stronger losses of mechano- and heat sensation with a faster onset than HIF1αfl/fl mice. Mechanistically, these histomorphologic, behavioral, and biochemical differences were associated with a significantly higher level of STZ-induced production of ROS and ROS-induced PKG1α dimerization in sensory neurons of SNS-HIF1α-/- mice as compared with HIF1αfl/fl. We found that prolonged hyperglycemia induced VEGF expression in the sciatic nerve which is impaired in SNS-HIF1α mice. Our results indicate that HIF1α is as an upstream modulator of ROS in peripheral sensory neurons and exerts a protective function in suppressing hyperglycemia-induced nerve damage by limiting ROS levels and by inducing expression of VEGF which may promote peripheral nerve survival. Our data suggested that HIF1α stabilization may be thus a new strategy target for limiting sensory loss, a debilitating late complication of diabetes. KEY MESSAGES: • Impaired hypoxia-inducible factor 1α (HIF1α) signaling leads to early onset of STZ-induced loss of sensation in mice. • STZ-induced loss of sensation in HIF1α mutant mice is associated with loss of sensory nerve fiber in skin. • Activation of HIF1α signaling in diabetic mice protects the sensory neurons by limiting ROS formation generated due to mitochondrial dysfunction and by inducing VEGF expression.
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Affiliation(s)
- Daniel Rangel Rojas
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, D-69120, Heidelberg, Germany
| | - Irmgard Tegeder
- Institute for Clinical Pharmacology, Goethe-University Hospital, Frankfurt, Germany
| | - Rohini Kuner
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, D-69120, Heidelberg, Germany
| | - Nitin Agarwal
- Institute of Pharmacology, Heidelberg University, Im Neuenheimer Feld 366, D-69120, Heidelberg, Germany.
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Shen H, Zhao J, Liu Y, Sun G. Interactions between and Shared Molecular Mechanisms of Diabetic Peripheral Neuropathy and Obstructive Sleep Apnea in Type 2 Diabetes Patients. J Diabetes Res 2018; 2018:3458615. [PMID: 30116739 PMCID: PMC6079583 DOI: 10.1155/2018/3458615] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Accepted: 06/26/2018] [Indexed: 02/07/2023] Open
Abstract
Type 2 diabetes (T2D) accounts for about 90% of all diabetes patients and incurs a heavy global public health burden. Up to 50% of T2D patients will eventually develop neuropathy as T2D progresses. Diabetic peripheral neuropathy (DPN) is a common diabetic complication and one of the main causes of increased morbidity and mortality of T2D patients. Obstructive sleep apnea (OSA) affects over 15% of the general population and is associated with a higher prevalence of T2D. Growing evidence also indicates that OSA is highly prevalent in T2D patients probably due to diabetic peripheral neuropathy. However, the interrelations among diabetic peripheral neuropathy, OSA, and T2D hitherto have not been clearly elucidated. Numerous molecular mechanisms have been documented that underlie diabetic peripheral neuropathy and OSA, including oxidative stress, inflammation, endothelin-1, vascular endothelial growth factor (VEGF), accumulation of advanced glycation end products, protein kinase C (PKC) signaling, poly ADP ribose polymerase (PARP), nitrosative stress, plasminogen activator inhibitor-1, and vitamin D deficiency. In this review, we seek to illuminate the relationships among T2D, diabetic peripheral neuropathy, and OSA and how they interact with one another. In addition, we summarize and explain the shared molecular mechanisms involved in diabetic peripheral neuropathy and OSA for further mechanistic investigations and novel therapeutic strategies for attenuating and preventing the development and progression of diabetic peripheral neuropathy and OSA in T2D.
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Affiliation(s)
- Hong Shen
- Department of Endocrinology, The Second Hospital of Jilin University, Changchun 130041, China
| | - Junrong Zhao
- Department of Nephrology, The Second Hospital of Jilin University, Changchun 130041, China
| | - Ying Liu
- Department of Nephrology, The Second Hospital of Jilin University, Changchun 130041, China
| | - Guangdong Sun
- Department of Nephrology, The Second Hospital of Jilin University, Changchun 130041, China
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Barrett EJ, Liu Z, Khamaisi M, King GL, Klein R, Klein BEK, Hughes TM, Craft S, Freedman BI, Bowden DW, Vinik AI, Casellini CM. Diabetic Microvascular Disease: An Endocrine Society Scientific Statement. J Clin Endocrinol Metab 2017; 102:4343-4410. [PMID: 29126250 PMCID: PMC5718697 DOI: 10.1210/jc.2017-01922] [Citation(s) in RCA: 287] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 08/29/2017] [Indexed: 01/18/2023]
Abstract
Both type 1 and type 2 diabetes adversely affect the microvasculature in multiple organs. Our understanding of the genesis of this injury and of potential interventions to prevent, limit, or reverse injury/dysfunction is continuously evolving. This statement reviews biochemical/cellular pathways involved in facilitating and abrogating microvascular injury. The statement summarizes the types of injury/dysfunction that occur in the three classical diabetes microvascular target tissues, the eye, the kidney, and the peripheral nervous system; the statement also reviews information on the effects of diabetes and insulin resistance on the microvasculature of skin, brain, adipose tissue, and cardiac and skeletal muscle. Despite extensive and intensive research, it is disappointing that microvascular complications of diabetes continue to compromise the quantity and quality of life for patients with diabetes. Hopefully, by understanding and building on current research findings, we will discover new approaches for prevention and treatment that will be effective for future generations.
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Affiliation(s)
- Eugene J. Barrett
- Division of Endocrinology, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908
| | - Zhenqi Liu
- Division of Endocrinology, Department of Medicine, University of Virginia, Charlottesville, Virginia 22908
| | - Mogher Khamaisi
- Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215
| | - George L. King
- Section of Vascular Cell Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts 02215
| | - Ronald Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705
| | - Barbara E. K. Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53705
| | - Timothy M. Hughes
- Sticht Center for Healthy Aging and Alzheimer’s Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Suzanne Craft
- Sticht Center for Healthy Aging and Alzheimer’s Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Barry I. Freedman
- Divisions of Nephrology and Endocrinology, Department of Internal Medicine, Centers for Diabetes Research, and Center for Human Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Donald W. Bowden
- Divisions of Nephrology and Endocrinology, Department of Internal Medicine, Centers for Diabetes Research, and Center for Human Genomics and Personalized Medicine Research, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Aaron I. Vinik
- EVMS Strelitz Diabetes Center, Eastern Virginia Medical Center, Norfolk, Virginia 23510
| | - Carolina M. Casellini
- EVMS Strelitz Diabetes Center, Eastern Virginia Medical Center, Norfolk, Virginia 23510
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Feldman EL, Nave KA, Jensen TS, Bennett DLH. New Horizons in Diabetic Neuropathy: Mechanisms, Bioenergetics, and Pain. Neuron 2017; 93:1296-1313. [PMID: 28334605 PMCID: PMC5400015 DOI: 10.1016/j.neuron.2017.02.005] [Citation(s) in RCA: 527] [Impact Index Per Article: 75.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 02/02/2017] [Accepted: 02/02/2017] [Indexed: 12/13/2022]
Abstract
Pre-diabetes and diabetes are a global epidemic, and the associated neuropathic complications create a substantial burden on both the afflicted patients and society as a whole. Given the enormity of the problem and the lack of effective therapies, there is a pressing need to understand the mechanisms underlying diabetic neuropathy (DN). In this review, we present the structural components of the peripheral nervous system that underlie its susceptibility to metabolic insults and then discuss the pathways that contribute to peripheral nerve injury in DN. We also discuss systems biology insights gleaned from the recent advances in biotechnology and bioinformatics, emerging ideas centered on the axon-Schwann cell relationship and associated bioenergetic crosstalk, and the rapid expansion of our knowledge of the mechanisms contributing to neuropathic pain in diabetes. These recent advances in our understanding of DN pathogenesis are paving the way for critical mechanism-based therapy development.
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Affiliation(s)
- Eva L Feldman
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany
| | - Troels S Jensen
- Department of Neurology and Danish Pain Research Center, Aarhus University, 8000 Aarhus C, Denmark
| | - David L H Bennett
- Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford OX3 9DU, UK
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16
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Abstract
The clinical manifestations, underlying pathology and aetiology of human diabetic neuropathy are varied and complex. Much data has been generated from preclinical models to provide a conceptual framework for the cause and treatment of human diabetic neuropathy. Despite this there remains much debate and controversy on the pathophysiology of the condition. Furthermore, many of the interventions reaching phase III clinical trials have failed to prove effective. To date we have no evidence-based and effective treatment(s) for human diabetic neuropathy.
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Affiliation(s)
- Rayaz Malik
- Department of Medicine, Manchester Royal Infirmary, Oxford Road, Manchester, M13 9WL, UK,
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17
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Tang-Tong-Fang Confers Protection against Experimental Diabetic Peripheral Neuropathy by Reducing Inflammation. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:574169. [PMID: 26539228 PMCID: PMC4619908 DOI: 10.1155/2015/574169] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 07/19/2015] [Accepted: 08/04/2015] [Indexed: 01/12/2023]
Abstract
Tang-tong-fang (TTF) is a Chinese herbal formula that has been shown to be beneficial in diabetic peripheral neuropathy (DPN), a common complication secondary to diabetic microvascular injury. However, the underlying mechanism of protection in nerve ischemia provided by TTF is still unclear. We hypothesized that TTF alleviates DPN via inhibition of ICAM-1 expression. Therefore, we tested the effect of TTF in a previously established DPN model, in which nerve injury was induced by ischemia/reperfusion in streptozotocin-induced diabetic rats. We found that the conduction velocity and amplitude of action potentials of sciatic nerve conduction were reduced in the DPN model group but were rescued by TTF treatment. In addition, TTF treatment also attenuated the effect of DPN on other parameters including histology and ultrastructural changes, expression of ICAM-1, MPO, and TNF-α in rat sciatic nerves, and plasma sICAM-1 and MPO levels. Together, our data suggest that TTF treatment may alleviate DPN via ICAM-1 inhibition.
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Combined therapy of diabetic peripheral neuropathy with breviscapine and mecobalamin: a systematic review and a meta-analysis of Chinese studies. BIOMED RESEARCH INTERNATIONAL 2015; 2015:680756. [PMID: 25866802 PMCID: PMC4383387 DOI: 10.1155/2015/680756] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 01/13/2015] [Accepted: 01/16/2015] [Indexed: 01/27/2023]
Abstract
Objective. A meta-analysis on combined therapy of diabetic peripheral neuropathy (DPN) with breviscapine and mecobalamin was performed to evaluate the efficacy of this therapy. Methods. Six English databases (Medline, Cochrane Library, PubMed, EMBASE, Web of Science, and CINAHL) and four Chinese databases (China National Knowledge Infrastructure, VIP Journals Database, CBM, and Wanfang database) were searched for studies on the clinical trials in which DPN was treated with breviscapine and mecobalamin, and RevMan 5.1 package was employed for analyzing pooled trials and publication bias. Results. A total of 17 articles including 1398 DPN patients were identified. Homogeneity was observed among different studies (P = 0.74). The efficacy of combined therapy with breviscapine and mecobalamin was significantly better than that in control group [P < 0.0001 (OR = 5.01, 95% CI: 3.70–6.78)]. Conclusion. Available findings suggest that the therapeutic efficacy of breviscapine combining mecobalamin is superior to mecobalamin alone, and this strategy is required to be popularized in clinical practice.
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Premkumar LS, Pabbidi RM. Diabetic peripheral neuropathy: role of reactive oxygen and nitrogen species. Cell Biochem Biophys 2014; 67:373-83. [PMID: 23722999 DOI: 10.1007/s12013-013-9609-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The prevalence of diabetes has reached epidemic proportions. There are two forms of diabetes: type 1 diabetes mellitus is due to auto-immune-mediated destruction of pancreatic β-cells resulting in absolute insulin deficiency and type 2 diabetes mellitus is due to reduced insulin secretion and or insulin resistance. Both forms of diabetes are characterized by chronic hyperglycemia, leading to the development of diabetic peripheral neuropathy (DPN) and microvascular pathology. DPN is characterized by enhanced or reduced thermal, chemical, and mechanical pain sensitivities. In the long-term, DPN results in peripheral nerve damage and accounts for a substantial number of non-traumatic lower-limb amputations. This review will address the mechanisms, especially the role of reactive oxygen and nitrogen species in the development and progression of DPN.
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Affiliation(s)
- Louis S Premkumar
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL, 62702, USA,
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20
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Wang D, Couture R, Hong Y. Activated microglia in the spinal cord underlies diabetic neuropathic pain. Eur J Pharmacol 2014; 728:59-66. [PMID: 24508519 DOI: 10.1016/j.ejphar.2014.01.057] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 01/23/2014] [Accepted: 01/29/2014] [Indexed: 12/22/2022]
Abstract
Diabetes mellitus is an increasingly common chronic medical condition. Approximately 30% of diabetic patients develop neuropathic pain, manifested as spontaneous pain, hyperalgesia and allodynia. Hyperglycemia induces metabolic changes in peripheral tissues and enhances oxidative stress in nerve fibers. The damages and subsequent reactive inflammation affect structural properties of Schwann cells and axons leading to the release of neuropoietic mediators, such as pro-inflammatory cytokines and pro-nociceptive mediators. Therefore, diabetic neuropathic pain (DNP) shares some histological features and underlying mechanisms with traumatic neuropathy. DNP displays, however, other distinct features; for instance, sensory input to the spinal cord decreases rather than increasing in diabetic patients. Consequently, development of central sensitization in DNP involves mechanisms that are distinct from traumatic neuropathic pain. In DNP, the contribution of spinal cord microglia activation to central sensitization and pain processes is emerging as a new concept. Besides inflammation in the periphery, hyperglycemia and the resulting production of reactive oxygen species affect the local microenvironment in the spinal cord. All these alterations could trigger resting and sessile microglia to the activated phenotype. In turn, microglia synthesize and release pro-inflammatory cytokines and neuroactive molecules capable of inducing hyperactivity of spinal nociceptive neurons. Hence, it is imperative to elucidate glial mechanisms underlying DNP for the development of effective therapeutic agents. The present review highlights the recent developments regarding the contribution of spinal microglia as compelling target for the treatment of DNP.
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Affiliation(s)
- Dongmei Wang
- College of Life Sciences and Provincial Key Laboratory of Developmental Biology and Neuroscience, Fujian Normal University, New campus, Fuzhou, Fujian 350108, People׳s Republic of China
| | - Réjean Couture
- Department of Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128, Succursale Downtown, Montréal, Québec, Canada H3C 3J7
| | - Yanguo Hong
- College of Life Sciences and Provincial Key Laboratory of Developmental Biology and Neuroscience, Fujian Normal University, New campus, Fuzhou, Fujian 350108, People׳s Republic of China.
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21
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Xu Q, Pan J, Yu J, Liu X, Liu L, Zuo X, Wu P, Deng H, Zhang J, Ji A. Meta-analysis of methylcobalamin alone and in combination with lipoic acid in patients with diabetic peripheral neuropathy. Diabetes Res Clin Pract 2013; 101:99-105. [PMID: 23664235 DOI: 10.1016/j.diabres.2013.03.033] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 02/12/2013] [Accepted: 03/25/2013] [Indexed: 11/24/2022]
Abstract
AIMS To compare the efficacy and safety of daily lipoic acid (300-600 mg i.v.) plus methylcobalamin (500-1000 mg i.v. or im.) (LA-MC) with that of methylcobalamin alone (MC) on diabetic peripheral neuropathy (DPN). METHODS Electronic database were searched for studies published up to November 1, 2012 and study quality was assessed in duplicate. A random or a fixed effect model was used to analyse outcomes which were expressed as risk ratios (RRs) or mean difference (MD). I(2) statistic was used to assess heterogeneity. RESULTS Seventeen studies were included. Combined data from all studies showed that the LA-MC combination therapy was significantly superior to MC monotherapy (RR=1.47; 95% CI: 1.37-1.58). Superiority of the LA-MC combination was shown in nerve conduction velocity (NCV) with WMDs of 6.89 (95% CI: 4.24-9.73) for median motor nerve conduction velocity (MNCV), 5.24 (4.14-6.34) for median sensory nerve conduction velocity (SNCV), 4.34 (3.03-5.64) for peroneal MNCV, and 4.53 (3.2-5.85) for peroneal SNCV. There were no serious adverse events associated with treatment. CONCLUSIONS The results of the meta-analysis show that treatment with LA-MC for 2-4 weeks is associated with better outcomes in NCV and neuropathic symptoms relative to MC treatment. However larger well-designed studies are required to confirm this conclusion.
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Affiliation(s)
- Qian Xu
- Department of Pharmacy, Zhu-Jiang Hospital, Southern Medical University, Guangzhou, China.
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22
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Van Dam PS, Cotter MA, Bravenboer B, Cameron NE. Pathogenesis of diabetic neuropathy: focus on neurovascular mechanisms. Eur J Pharmacol 2013; 719:180-186. [PMID: 23872412 DOI: 10.1016/j.ejphar.2013.07.017] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Accepted: 07/11/2013] [Indexed: 02/08/2023]
Abstract
Neuropathies of the peripheral and autonomic nervous systems affect up to half of all people with diabetes, and are major risk factors for foot ulceration and amputation. The aetiology is multifactorial: metabolic changes in diabetes may directly affect neural tissue, but importantly, neurodegenerative changes are precipitated by compromised nerve vascular supply. Experiments in animal models of diabetic neuropathy suggest that similar metabolic sequelae affect neurons and vasa nervorum endothelium. These include elevated polyol pathway activity, oxidative stress, the formation of advanced glycation and lipoxidation end products, and various pro-inflammatory changes such as elevated protein kinase C, nuclear factor κB and p38 mitogen activated protein kinase signalling. These mechanisms do not work in isolation but strongly interact in a mutually facilitatory fashion. Nitrosative stress and the induction of the enzyme poly (ADP-ribose) polymerase form one important link between physiological stressors such as reactive oxygen species and the pro-inflammatory mechanisms. Recently, evidence points to endoplasmic stress and the unfolded protein response as forming another crucial link. This review focuses on the aetiopathogenesis of neurovascular changes in diabetic neuropathy, elucidated in animal studies, and on putative therapeutic targets the majority of which have yet to be tested for efficacy in clinical trials.
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Affiliation(s)
- P Sytze Van Dam
- Onze Lieve Vrouwe Gasthuis, Department of internal Medicine, PO Box 95500, 1090HM Amsterdam, The Netherlands
| | - Mary A Cotter
- School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland UK
| | | | - Norman E Cameron
- School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, Scotland UK.
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23
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Alaverdyan AR, Vartanyan GS. The effects of protein kinase C inhibitors on the contents of several transcription and apoptosis modulating factors in the spinal cords of rats with diabetic neuropathy. NEUROCHEM J+ 2012. [DOI: 10.1134/s1819712412030026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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24
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Treatment of diabetic neuropathy with baicalein: intervention at multiple sites. Exp Neurol 2011; 232:105-9. [PMID: 21907195 DOI: 10.1016/j.expneurol.2011.08.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 08/10/2011] [Accepted: 08/18/2011] [Indexed: 01/03/2023]
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25
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Chowdhury SKR, Dobrowsky RT, Fernyhough P. Nutrient excess and altered mitochondrial proteome and function contribute to neurodegeneration in diabetes. Mitochondrion 2011; 11:845-54. [PMID: 21742060 DOI: 10.1016/j.mito.2011.06.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 04/28/2011] [Accepted: 06/24/2011] [Indexed: 01/01/2023]
Abstract
Diabetic neuropathy is a major complication of diabetes that results in the progressive deterioration of the sensory nervous system. Mitochondrial dysfunction has been proposed to play an important role in the pathogenesis of the neurodegeneration observed in diabetic neuropathy. Our recent work has shown that mitochondrial dysfunction occurs in dorsal root ganglia (DRG) sensory neurons in streptozotocin (STZ) induced diabetic rodents. In neurons, the nutrient excess associated with prolonged diabetes may trigger a switching off of AMP kinase (AMPK) and/or silent information regulator T1 (SIRT1) signaling leading to impaired peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1α) expression/activity and diminished mitochondrial activity. This review briefly summarizes the alterations of mitochondrial function and proteome in sensory neurons of STZ-diabetic rodents. We also discuss the possible involvement of AMPK/SIRT/PGC-1α pathway in other diabetic models and different tissues affected by diabetes.
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Affiliation(s)
- Subir K Roy Chowdhury
- Division of Neurodegenerative Disorders, St Boniface Hospital Research Centre, Winnipeg, MB, Canada R2H 2A6
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26
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Mizukami H, Ogasawara S, Yamagishi SI, Takahashi K, Yagihashi S. Methylcobalamin effects on diabetic neuropathy and nerve protein kinase C in rats. Eur J Clin Invest 2011; 41:442-50. [PMID: 21128935 DOI: 10.1111/j.1365-2362.2010.02430.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Methyl-base-attached cobalamin (Methycobalamin) (MC) has a special affinity for nerve tissues to promote myelination and transport of axonal cytoskeleton. It is not known, however, how MC influences on peripheral nerve in experimental diabetic neuropathy. MATERIALS AND METHODS We studied the effects of MC on expressions and activities of protein kinase C (PKC) in peripheral nerve of streptozotocin-induced diabetic rats. Wistar rats, 8 weeks of age, were rendered diabetic by streptozotocin (40 mg kg(-1), iv) and followed for 16 weeks. A half of diabetic animals were treated with MC (10 mg kg(-1) per every other day, im) after the induction of diabetes. Normal Wistar rats were served as control. RESULTS At the end, untreated diabetic animals developed significant delay of nerve conduction velocity (NCV), and MC treatment normalized the NCV. Nerve PKC activity was significantly suppressed in untreated diabetic rats, while the activity was normalized in treated animals. While PKCα located in Schwann cells, PKCβΙα and βII distributed in axoplasm, vascular walls and macrophages. The decreased PKC activity in diabetic nerve was associated with reduced expression of membrane PKCα and increased membrane expression of PKCβII, and MC treatment corrected these changes. Diabetic nerve contained an increased number of macrophages and 8-hydroxydeoxyguanosine-positive cells in the endoneurium, the latter of which was significantly suppressed by MC treatment. Elevated nerve polyol levels in diabetic nerve were partially corrected by MC treatment. CONCLUSIONS This study suggested that correction of impaired neural signalling of PKC and oxidative stress-induced damage may be a major attribute to the beneficial effects of MC on diabetic nerve.
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Affiliation(s)
- Hiroki Mizukami
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
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27
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Pulsed Electromagnetic Fields to Reduce Diabetic Neuropathic Pain and Stimulate Neuronal Repair: A Randomized Controlled Trial. Arch Phys Med Rehabil 2009; 90:1102-9. [DOI: 10.1016/j.apmr.2009.01.019] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2008] [Revised: 12/16/2008] [Accepted: 01/11/2009] [Indexed: 01/13/2023]
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28
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Vardanyan GS, Alaverdyan AR. Protein kinase C: from its specific molecular structure to its role in diabetic neuropathy. NEUROCHEM J+ 2009. [DOI: 10.1134/s1819712409010024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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29
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Obrosova IG. Diabetes and the peripheral nerve. Biochim Biophys Acta Mol Basis Dis 2008; 1792:931-40. [PMID: 19061951 DOI: 10.1016/j.bbadis.2008.11.005] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2008] [Revised: 11/05/2008] [Accepted: 11/06/2008] [Indexed: 12/11/2022]
Abstract
Diabetes-induced damage to peripheral nerve culminates in development of peripheral diabetic neuropathy (PDN), one of the most devastating complications of diabetes mellitus and a leading cause of foot amputation. The pathogenesis of PDN occurs as a consequence of complex interactions among multiple hyperglycemia-initiated mechanisms, impaired insulin signaling, inflammation, hypertension, and disturbances of fatty acid and lipid metabolism. This review describes experimental new findings in animal and cell culture models as well as clinical data suggesting the importance of 1) previously established hyperglycemia-initiated mechanisms such as increased aldose reductase activity, non-enzymatic glycation/glycooxidation, activation of protein kinase C, 2) oxidative-nitrosative stress and poly(ADP-ribose) polymerase activation; 3) mitogen-activated protein kinase and cyclooxygenase-2 activation, impaired Ca(++) homeostasis and signaling, and several other mechanisms, in PDN.
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Affiliation(s)
- Irina G Obrosova
- Pennington Biomedical Research Center, Louisiana State University, 6400 Perkins Road, Baton Rouge, Louisiana 70808, USA.
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30
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Huang SM, Hsu CL, Chuang HC, Shih PH, Wu CH, Yen GC. Inhibitory effect of vanillic acid on methylglyoxal-mediated glycation in apoptotic Neuro-2A cells. Neurotoxicology 2008; 29:1016-22. [DOI: 10.1016/j.neuro.2008.07.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2008] [Revised: 06/17/2008] [Accepted: 07/14/2008] [Indexed: 02/02/2023]
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31
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Pabbidi RM, Yu SQ, Peng S, Khardori R, Pauza ME, Premkumar LS. Influence of TRPV1 on diabetes-induced alterations in thermal pain sensitivity. Mol Pain 2008; 4:9. [PMID: 18312687 PMCID: PMC2275252 DOI: 10.1186/1744-8069-4-9] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Accepted: 03/01/2008] [Indexed: 12/24/2022] Open
Abstract
A common complication associated with diabetes is painful or painless diabetic peripheral neuropathy (DPN). The mechanisms and determinants responsible for these peripheral neuropathies are poorly understood. Using both streptozotocin (STZ)-induced and transgene-mediated murine models of type 1 diabetes (T1D), we demonstrate that Transient Receptor Potential Vanilloid 1 (TRPV1) expression varies with the neuropathic phenotype. We have found that both STZ- and transgene-mediated T1D are associated with two distinct phases of thermal pain sensitivity that parallel changes in TRPV1 as determined by paw withdrawal latency (PWL). An early phase of hyperalgesia and a late phase of hypoalgesia are evident. TRPV1-mediated whole cell currents are larger and smaller in dorsal root ganglion (DRG) neurons collected from hyperalgesic and hypoalgesic mice. Resiniferatoxin (RTX) binding, a measure of TRPV1 expression is increased and decreased in DRG and paw skin of hyperalgesic and hypoalgesic mice, respectively. Immunohistochemical labeling of spinal cord lamina I and II, dorsal root ganglion (DRG), and paw skin from hyperalgesic and hypoalgesic mice reveal increased and decreased TRPV1 expression, respectively. A role for TRPV1 in thermal DPN is further suggested by the failure of STZ treatment to influence thermal nociception in TRPV1 deficient mice. These findings demonstrate that altered TRPV1 expression and function contribute to diabetes-induced changes in thermal perception.
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Affiliation(s)
- Reddy M Pabbidi
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield, IL 62702, USA.
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32
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Malik RA, Veves A, Tesfaye S. Ameliorating human diabetic neuropathy: Lessons from implanting hematopoietic mononuclear cells. Exp Neurol 2006; 201:7-14. [PMID: 16808913 DOI: 10.1016/j.expneurol.2006.04.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2006] [Revised: 03/24/2006] [Accepted: 04/12/2006] [Indexed: 11/24/2022]
Affiliation(s)
- R A Malik
- Division of Cardiovascular and Endocrine Sciences, University of Manchester, Manchester, UK.
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Joy SV, Scates AC, Bearelly S, Dar M, Taulien CA, Goebel JA, Cooney MJ. Ruboxistaurin, a protein kinase C beta inhibitor, as an emerging treatment for diabetes microvascular complications. Ann Pharmacother 2005; 39:1693-9. [PMID: 16160002 DOI: 10.1345/aph.1e572] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To review current clinical data regarding the pharmacologic actions of ruboxistaurin (LY333531) mesylate, an inhibitor of protein kinase C (PKC) beta, and its role to potentially reduce the development and/or the progression of diabetic microvascular complications. DATA SOURCES Primary literature was obtained via a MEDLINE search (1966-August 2004) and through review of pertinent abstracts and presentations at major medical meetings. STUDY SELECTION AND DATA EXTRACTION Literature relevant to PKC physiology, the pharmacokinetics of ruboxistaurin, and data evaluating the use of ruboxistaurin in treating diabetic microvascular complications in human and relevant animal models was reviewed. DATA SYNTHESIS PKC is part of a group of intracellular signaling molecules activated in response to various specific hormonal, neuronal, and growth factor stimuli. Hyperglycemia leads to PKC beta 1 and 2 isoform activation, which experimentally has been shown to contribute to the development and progression of diabetic microvascular complications (retinopathy, nephropathy, neuropathy) through various biochemical mechanisms. Animal and/or human studies using ruboxistaurin mesylate, a novel, highly selective inhibitor of PKC beta, have shown delay in the progression and, in some cases, reversal of diabetic retinopathy, nephropathy, and neuropathy. CONCLUSIONS Ruboxistaurin mesylate, by inhibiting excessive activation of certain PKC isoforms, has the potential to reduce the burden of microvascular complications for patients with diabetes.
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Affiliation(s)
- Scott V Joy
- Department of Medicine, Duke University Medical Center, Durham, NC 27705-0493, USA
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Van Buren JJ, Bhat S, Rotello R, Pauza ME, Premkumar LS. Sensitization and translocation of TRPV1 by insulin and IGF-I. Mol Pain 2005; 1:17. [PMID: 15857517 PMCID: PMC1142339 DOI: 10.1186/1744-8069-1-17] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Accepted: 04/27/2005] [Indexed: 12/27/2022] Open
Abstract
Insulin and insulin-like growth factors (IGFs) maintain vital neuronal functions. Absolute or functional deficiencies of insulin or IGF-I may contribute to neuronal and vascular complications associated with diabetes. Vanilloid receptor 1 (also called TRPV1) is an ion channel that mediates inflammatory thermal nociception and is present on sensory neurons. Here we demonstrate that both insulin and IGF-I enhance TRPV1-mediated membrane currents in heterologous expression systems and cultured dorsal root ganglion neurons. Enhancement of membrane current results from both increased sensitivity of the receptor and translocation of TRPV1 from cytosol to plasma membrane. Receptor tyrosine kinases trigger a signaling cascade leading to activation of phosphatidylinositol 3-kinase (PI(3)K) and protein kinase C (PKC)-mediated phosphorylation of TRPV1, which is found to be essential for the potentiation. These findings establish a link between the insulin family of trophic factors and vanilloid receptors.
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Affiliation(s)
- Jeremy J Van Buren
- Department of Pharmacology, Southern Illinois University School of Medicine Springfield, IL 62702, USA
| | - Satyanarayan Bhat
- Department of Pharmacology, Southern Illinois University School of Medicine Springfield, IL 62702, USA
| | - Rebecca Rotello
- Department of Pharmacology, Southern Illinois University School of Medicine Springfield, IL 62702, USA
| | - Mary E Pauza
- Department of Medical Microbiology and Immunology, Southern Illinois University School of Medicine Springfield, IL 62702, USA
- Department of Internal Medicine, Southern Illinois University School of Medicine Springfield, IL 62702, USA
| | - Louis S Premkumar
- Department of Pharmacology, Southern Illinois University School of Medicine Springfield, IL 62702, USA
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Uehara K, Yamagishi SI, Otsuki S, Chin S, Yagihashi S. Effects of polyol pathway hyperactivity on protein kinase C activity, nociceptive peptide expression, and neuronal structure in dorsal root ganglia in diabetic mice. Diabetes 2004; 53:3239-47. [PMID: 15561956 DOI: 10.2337/diabetes.53.12.3239] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We explored the specific impact of polyol pathway hyperactivity on dorsal root ganglia (DRG) using transgenic mice that overexpress human aldose reductase because DRG changes are crucial for the development of diabetic sensory neuropathy. Littermate mice served as controls. Half of the animals were made diabetic by streptozotocin injection and followed for 12 weeks. After diabetes onset, diabetic transgenic mice showed a significant elevation of pain sensation threshold after transient decrease and marked slowing of motor and sensory nerve conduction at the end of the study, while these changes were modest in diabetic littermate mice. Protein kinase C (PKC) activities were markedly reduced in diabetic transgenic mice, and the changes were associated with reduced expression of membrane PKC-alpha isoform that was translocated to cytosol. Membrane PKC-betaII isoform expression was contrariwise increased. Calcitonin gene-related peptide-and substance P-positive neurons were reduced in diabetic transgenic mice and less severely so in diabetic littermate mice. Morphometric analysis disclosed neuronal atrophy only in diabetic transgenic mice. Treatment with an aldose reductase inhibitor (fidarestat 4 mg x kg(-1) x day(-1), orally) corrected all of the changes detected in diabetic transgenic mice. These findings underscore the pathogenic role of aldose reductase in diabetic sensory neuropathy through the altered cellular signaling and peptide expressions in DRG neurons.
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Affiliation(s)
- Kenji Uehara
- Department of Pathology, Hirosaki University School of Medicine, Hirosaki, Japan
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Affiliation(s)
- Andrew J M Boulton
- Division of Endocrinology, University of Miami School of Medicine, P.O. Box 016960 (D-110), Miami, Florida, USA.
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Abstract
The first purpose of this article is to examine general signaling transduction processes that become deranged in diabetes and the means by which they damage cells. However, among the cells that can be damaged by diabetes, the primary sensory neurons, also known as dorsal root ganglion (DRG) neurons, are uniquely sensitive. Damage to these cells results in diabetic peripheral neuropathy (DPN), one of the costliest and most common diabetic complications. Therefore, the second purpose of this article is to focus attention on factors that make these cells particularly vulnerable to hyperglycemic damage. Some clinical inferences are drawn from these considerations. Finally, limitations in our knowledge about the effects of diabetes on signaling in DRG neurons are illustrated in an overview of the basic research literature.
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Affiliation(s)
- Jeannette M McHugh
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, USA
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Bierhaus A, Humpert PM, Rudofsky G, Wendt T, Morcos M, Hamann A, Nawroth PP. New treatments for diabetic neuropathy: pathogenetically oriented treatment. Curr Diab Rep 2003; 3:452-8. [PMID: 14611740 DOI: 10.1007/s11892-003-0007-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although there is clear evidence from experimental diabetic neuropathy (DN) models that the multiple pathways involved in neuronal degeneration cause overproduction of reactive oxygen species, oxidative stress, and cellular dysfunction, therapeutic approaches addressing these mechanisms have not yet provided a basis for a successful treatment of patients with DN. This review discusses the current knowledge on the pathomechanisms of unchecked reactive oxygen species accumulation, implications for specific treatment, and the need for carefully designed experimental studies and clinical trials closing the gap between promising results in experimental DN and its implementation into a pathogenetically oriented treatment.
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Abstract
Peripheral diabetic neuropathy (PDN) affects up to 60% to 70% of diabetic patients, and is the leading cause of foot amputation. The pathogenesis of PDN involves multiple mechanisms. The findings obtained in 1999 to 2003 support the role of previously established mechanisms such as increased aldose reductase activity, nonenzymatic glycation or glyco-oxidation, activation of protein kinase C, enhanced oxidative stress, impaired neurotrophic support, and reveal the importance of new downstream effectors of oxidative injury. Those include mitogen-activated protein kinases and poly (ADP-ribose) polymerase that are activated by diabetes, and contribute to such neuropathic changes as motor and sensory nerve conduction deficits, decreased nerve blood flow, and energy failure. Further studies are needed to understand the role of other signaling pathways as well as interactions among previously discovered mechanisms in the pathogenesis of PDN.
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Affiliation(s)
- Irina G Obrosova
- University of Michigan, Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Michigan Medical Center, 1150 West Medical Center Drive, MSRB II, Room 5570, Ann Arbor, MI 48109-0678, USA.
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Abstract
Diabetic neuropathy is common, related to increased morbidity and mortality, and has no effective treatment at present. Interventions based on putative pathways thought to contribute to damage and repair of nerve fibres have yielded little success to date. Pain is a potentially debilitating manifestation of diabetic neuropathy and has many potential sites of origin and, hence, modulation. Its cause is unclear and it does not respond well to traditional pain therapies, proposed to mediate their benefits via multiple peripheral and central mechanisms. A better understanding of the mechanisms leading to nerve fibre degeneration and regeneration as well as pain has recently resulted in the development of a more targeted approach to the treatment of diabetic neuropathy. Thus, specific NMDA receptor antagonists and more specific neuronal serotonin and norepinephrine (noradrenaline) uptake inhibitors offer promise in the treatment of painful diabetic neuropathy. A number of treatments which include the aldose reductase inhibitors and neurotrophins have failed to reach the clinical arena. However, the antioxidant alpha-lipoic acid, as well as compounds which correct vascular dysfunction and hence neuropathy, such as ACE inhibitors and protein kinase C-beta inhibitors, have demonstrated more success.
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Affiliation(s)
- Rayaz A Malik
- Department of Medicine, Manchester Royal Infirmary, Manchester, UK.
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