1
|
Pardo ID, Rao DB, Butt MT, Jortner BS, Valentine WM, Arezzo J, Sharma AK, Bolon B. Toxicologic Pathology of the Peripheral Nervous System (PNS): Overview, Challenges, and Current Practices. Toxicol Pathol 2018; 46:1028-1036. [DOI: 10.1177/0192623318800707] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Peripheral nervous system (PNS) toxicity is a frequent adverse effect encountered in patients treated with certain therapeutics (e.g., antiretroviral drugs, cancer chemotherapeutics), in occupational workers exposed to industrial chemicals (e.g., solvents), or during accidental exposures to household chemicals and/or environmental agents (e.g., pesticides). However, the literature and expertise needed for the effective design, conduct, analysis, and reporting of safety studies to identify and define PNS toxicity are hard to find. This half-day course familiarized participants with basic PNS biology; causes and mechanisms of PNS pathology; classic methods and current best practice recommendations for PNS sampling, preparation, and evaluation; and examples of commonly observed lesions and artifacts. Three concluding case presentations synthesized information from the prior technical lectures by presenting real-world examples of lesions caused by drugs and chemicals to demonstrate how PNS toxicity may be addressed in evaluating product safety during nonclinical studies. Topics emphasized comparative and correlative data among animal species used in toxicity studies and clinical evaluation in humans in order to facilitate the translation of animal data into human risk assessment with respect to PNS toxicologic pathology.
Collapse
Affiliation(s)
| | - Deepa B. Rao
- Current employer: Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland, USA
| | - Mark T. Butt
- Tox Path Specialists, LLC, Frederick, Maryland, USA
| | - Bernard S. Jortner
- Virginia–Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA
| | | | - Joseph Arezzo
- Albert Einstein College of Medicine, Bronx, New York, USA
| | | | - Brad Bolon
- GEMpath Inc., Longmont, Colorado, USA *Ingrid D. Pardo and Deepa B. Rao contributed equally to production of this article
| |
Collapse
|
2
|
Jensen VFH, Molck AM, Soeborg H, Nowak J, Chapman M, Lykkesfeldt J, Bogh IB. Proximal Neuropathy and Associated Skeletal Muscle Changes Resembling Denervation Atrophy in Hindlimbs of Chronic Hypoglycaemic Rats. Basic Clin Pharmacol Toxicol 2017; 122:165-175. [PMID: 28815909 DOI: 10.1111/bcpt.12870] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/19/2017] [Indexed: 11/29/2022]
Abstract
Peripheral neuropathy is one of the most common complications of diabetic hyperglycaemia. Insulin-induced hypoglycaemia (IIH) might potentially exacerbate or contribute to neuropathy as hypoglycaemia also causes peripheral neuropathy. In rats, IIH induces neuropathy associated with skeletal muscle changes. Aims of this study were to investigate the progression and sequence of histopathologic changes caused by chronic IIH in rat peripheral nerves and skeletal muscle, and whether such changes were reversible. Chronic IIH was induced by infusion of human insulin, followed by an infusion-free recovery period in some of the animals. Sciatic, plantar nerves and thigh muscle were examined histopathologically after four or eight weeks of infusion and after the recovery period. IIH resulted in high incidence of axonal degeneration in sciatic nerves and low incidence in plantar nerves indicating proximo-distal progression of the neuropathy. The neuropathy progressed in severity (sciatic nerve) and incidence (sciatic and plantar nerve) with the duration of IIH. The myopathy consisted of groups of angular atrophic myofibres which resembled histopathologic changes classically seen after denervation of skeletal muscle, and severity of the myofibre atrophy correlated with severity of axonal degeneration in sciatic nerve. Both neuropathy and myopathy were still present after four weeks of recovery, although the neuropathy was less severe. In conclusion, the results suggest that peripheral neuropathy induced by IIH progresses proximo-distally, that severity and incidence increase with duration of the hypoglycaemia and that these changes are partially reversible within four weeks. Furthermore, IIH-induced myopathy is most likely secondary to the neuropathy.
Collapse
Affiliation(s)
- Vivi F H Jensen
- Section for Experimental Animal Models, Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Toxicology, Safety Pharm and Pathology, Novo Nordisk A/S, Maaloev, Denmark
| | - Anne-Marie Molck
- Department of Toxicology, Safety Pharm and Pathology, Novo Nordisk A/S, Maaloev, Denmark
| | - Henrik Soeborg
- Department of Toxicology, Safety Pharm and Pathology, Novo Nordisk A/S, Maaloev, Denmark
| | - Jette Nowak
- Department of Toxicology, Safety Pharm and Pathology, Novo Nordisk A/S, Maaloev, Denmark
| | | | - Jens Lykkesfeldt
- Section for Experimental Animal Models, Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ingrid B Bogh
- Department of Toxicology, Safety Pharm and Pathology, Novo Nordisk A/S, Maaloev, Denmark
| |
Collapse
|
3
|
Jensen VFH, Mølck AM, Heydenreich A, Jensen KJ, Bertelsen LO, Alifrangis L, Andersen L, Søeborg H, Chapman M, Lykkesfeldt J, Bøgh IB. Histopathological nerve and skeletal muscle changes in rats subjected to persistent insulin-induced hypoglycemia. J Toxicol Pathol 2015; 29:17-30. [PMID: 26989298 PMCID: PMC4766526 DOI: 10.1293/tox.2015-0041] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 09/16/2015] [Indexed: 11/19/2022] Open
Abstract
New insulin analogues with a longer duration of action and a flatter pharmacodynamic profile are developed to improve convenience and safety for diabetic patients. During the nonclinical development of such analogues, safety studies must be conducted in nondiabetic rats, which consequently are rendered chronically hypoglycemic. A rat comparator model using human insulin would be valuable, as it would enable differentiation between effects related to either persistent insulin-induced hypoglycemia (IIH) or a new analogue per se. Such a model could alleviate the need for an in-study-comparator and thereby reduce the number of animals used during development. Thus, the aims of the present study were i) to develop a preclinical animal model of persistent hypoglycemia in rats using human insulin infusion for four weeks and ii) to investigate histopathological changes in sciatic nerves and quadriceps femoris muscle tissue, as little is known about the response to persistent hypoglycemia in these tissues. Histopathologic changes in insulin-infused animals included axonal degeneration and myofibre degeneration. To our knowledge, this is the first study to show that persistent IIH provokes peripheral nerve and skeletal myofiber degeneration within the same animals. This suggests that the model can serve as a nonclinical comparator model during development of long-acting insulin analogues.
Collapse
Affiliation(s)
- Vivi Flou Hjorth Jensen
- Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870 Frederiksberg C, Denmark; Novo Nordisk A/S, Novo Nordisk Park 1, 2760 Maaloev, Denmark
| | | | | | | | | | - Lene Alifrangis
- Novo Nordisk A/S, Novo Nordisk Park 1, 2760 Maaloev, Denmark
| | - Lene Andersen
- Novo Nordisk A/S, Novo Nordisk Park 1, 2760 Maaloev, Denmark
| | - Henrik Søeborg
- Novo Nordisk A/S, Novo Nordisk Park 1, 2760 Maaloev, Denmark
| | - Melissa Chapman
- Huntingdon Life Sciences, Barric Lane, Eye, Suffolk, IP23 7PX, UK
| | - Jens Lykkesfeldt
- Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1870 Frederiksberg C, Denmark
| | | |
Collapse
|
4
|
Lozeron P. Neuropatie delle ipoglicemie. Neurologia 2015. [DOI: 10.1016/s1634-7072(15)72179-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
5
|
Mojaddidi MA, Ahmed MS, Ali R, Jeziorska M, Al-Sunni A, Thomsen NOB, Dahlin LB, Malik RA. Molecular and pathological studies in the posterior interosseous nerve of diabetic and non-diabetic patients with carpal tunnel syndrome. Diabetologia 2014; 57:1711-9. [PMID: 24865616 DOI: 10.1007/s00125-014-3271-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 04/22/2014] [Indexed: 12/24/2022]
Abstract
AIMS/HYPOTHESIS We sought to establish the molecular and pathological changes predisposing diabetic and non-diabetic patients to the development of carpal tunnel syndrome (CTS). METHODS The posterior interosseous nerve (PIN) was biopsied in 25 diabetic and 19 non-diabetic patients undergoing carpal tunnel decompression for CTS. Detailed morphometric and immunohistological analyses were performed in the nerve biopsy. RESULTS In diabetic patients median nerve distal motor latency was prolonged (p < 0.05 vs non-diabetic patients), PIN myelinated fibre density (p < 0.05), fibre area (p < 0.0001) and axon area (p < 0.0001) were reduced, the percentage of unassociated Schwann cell profiles (p < 0.0001) and unmyelinated axon density (p < 0.0001) were increased and the axon diameter was reduced (p < 0.0001). Endoneurial capillary basement membrane area was increased (p < 0.0001) in diabetic patients, but endothelial cell number was increased (p < 0.01) and luminal area was reduced (p < 0.05) in non-diabetic patients with CTS. There was no difference in the expression of hypoxia-inducible factor 1α between diabetic and non-diabetic patients with CTS. However, the expression of vascular endothelial growth factor A (VEGF) (p < 0.05) and its receptors VEGFR-1 (p < 0.01) and VEGFR-2 (p < 0.05) was significantly increased in diabetic patients, particularly those with type 1 diabetes, and related to the severity of nerve fibre pathology. CONCLUSIONS/INTERPRETATION This study demonstrates increased nerve fibre and microvascular pathology in relation to enhanced expression of VEGF and its receptors in a non-compressed nerve in diabetic compared with non-diabetic patients with CTS. It therefore provides a potential molecular and pathological basis for the predisposition of diabetic patients to the development of CTS.
Collapse
Affiliation(s)
- Moaz A Mojaddidi
- Centre for Endocrinology and Diabetes, Institute of Human Development, Faculty of Medical and Human Sciences, The University of Manchester, AV Hill Building, Oxford Road, Manchester, M13 9PT, UK
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Jensen VFH, Mølck AM, Bøgh IB, Lykkesfeldt J. Effect of insulin-induced hypoglycaemia on the peripheral nervous system: focus on adaptive mechanisms, pathogenesis and histopathological changes. J Neuroendocrinol 2014; 26:482-96. [PMID: 24921897 DOI: 10.1111/jne.12170] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 05/22/2014] [Accepted: 06/05/2014] [Indexed: 12/31/2022]
Abstract
Insulin-induced hypoglycaemia (IIH) is a common acute side effect in type 1 and type 2 diabetic patients, especially during intensive insulin therapy. The peripheral nervous system (PNS) depends on glucose as its primary energy source during normoglycaemia and, consequently, it may be particularly susceptible to IIH damage. Possible mechanisms for adaption of the PNS to IIH include increased glucose uptake, utilisation of alternative energy substrates and the use of Schwann cell glycogen as a local glucose reserve. However, these potential adaptive mechanisms become insufficient when the hypoglycaemic state exceeds a certain level of severity and duration, resulting in a sensory-motor neuropathy with associated skeletal muscle atrophy. Large myelinated motor fibres appear to be particularly vulnerable. Thus, although the PNS is not an obligate glucose consumer, as is the brain, it appears to be more prone to IIH than the central nervous system when hypoglycaemia is not severe (blood glucose level ≤ 2 mm), possibly reflecting a preferential protection of the brain during periods of inadequate glucose availability. With a primary focus on evidence from experimental animal studies investigating nondiabetic IIH, the present review discusses the effect of IIH on the PNS with a focus on adaptive mechanisms, pathogenesis and histological changes.
Collapse
Affiliation(s)
- V F H Jensen
- Department of Veterinary Disease, Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Diabetes Toxicology and Safety Pharmacology, Novo Nordisk A/S, Maaloev, Denmark
| | | | | | | |
Collapse
|
7
|
Abstract
Hypoglycemia occurs in diabetic patients as a consequence of treatment with hypoglycemic agents, in insulinoma patients as a result of excessive insulin production, and in infants as a result of abnormal regulation of metabolism. Profound hypoglycemia can cause structural and functional disturbances in both the central (CNS) and the peripheral nervous system (PNS). The brain is damaged by a short and severe episode of hypoglycemia, whereas PNS pathology appears after a mild and prolonged episode. In the CNS, damaged mitochondria, elevated intracellular Ca2(+) level, released cytochrome c to the cytosol, extensive production of superoxide, increased caspase-3 activity, release of aspartate and glutamate from presynaptic terminals, and altered biosynthetic machinery can lead to neuronal cell death in the brain. Considering the PNS, chronic hypoglycemia is associated with delayed motor and sensory conduction velocities in peripheral nerves. With respect to pathology, hypoglycemic neuropathy in the PNS is characterized by Wallerian-like axonal degeneration that starts at the nerve terminal and progresses to a more proximal part of the axon, and motor axons to the muscles may be more severely damaged than sensory axons. Since excitatory neurotransmitters primarily involve the neuron in the CNS, this "dying back" pattern of axonal damage in the PNS may involve mechanisms other than excitotoxicity.
Collapse
Affiliation(s)
- Simin Mohseni
- Department of Clinical and Experimental Medicine, Division of Cell Biology, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
| |
Collapse
|
8
|
Sugimoto K, Baba M, Suzuki S, Yagihashi S. The impact of low-dose insulin on peripheral nerve insulin receptor signaling in streptozotocin-induced diabetic rats. PLoS One 2013; 8:e74247. [PMID: 24023699 PMCID: PMC3758356 DOI: 10.1371/journal.pone.0074247] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 07/31/2013] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND The precise mechanisms of the neuroprotective effects of insulin in streptozotocin (STZ)-induced diabetic animals remain unknown, but altered peripheral nerve insulin receptor signaling due to insulin deficiency might be one cause. METHODOLOGY AND PRINCIPAL FINDINGS Diabetes was induced in 10-week-old, male Wistar rats by injecting them with STZ (45 mg/kg). They were assigned to one group that received half of an insulin implant (∼1 U/day; I-group, n = 11) or another that remained untreated (U-group, n = 10) for 6 weeks. The controls were age- and sex-matched, non-diabetic Wistar rats (C-group, n = 12). Low-dose insulin did not change haemoglobin A1c, which increased by 136% in the U-group compared with the C-group. Thermal hypoalgesia and mechanical hyperalgesia developed in the U-group, but not in the I-group. Sensory and motor nerve conduction velocities decreased in the U-group, whereas sensory nerve conduction velocity increased by 7% (p = 0.0351) in the I-group compared with the U-group. Western blots showed unaltered total insulin receptor (IR), but a 31% decrease and 3.1- and 4.0-fold increases in phosphorylated IR, p44, and p42 MAPK protein levels, respectively, in sciatic nerves from the U-group compared with the C-group. Phosphorylated p44/42 MAPK protein decreased to control levels in the I-group (p<0.0001). CONCLUSIONS AND SIGNIFICANCE Low-dose insulin deactivated p44/42 MAPK and ameliorated peripheral sensory nerve dysfunction in rats with STZ-induced diabetes. These findings support the notion that insulin deficiency per se introduces impaired insulin receptor signaling in type 1 diabetic neuropathy.
Collapse
MESH Headings
- Animals
- Behavior, Animal/drug effects
- Blotting, Western
- Body Weight/drug effects
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Diabetes Mellitus, Experimental/physiopathology
- Dose-Response Relationship, Drug
- Fluorescent Antibody Technique
- Ganglia, Spinal/drug effects
- Ganglia, Spinal/enzymology
- Ganglia, Spinal/pathology
- Insulin/administration & dosage
- Insulin/pharmacology
- Insulin/therapeutic use
- Male
- Mitogen-Activated Protein Kinase 3/metabolism
- Myelin Sheath/metabolism
- Neural Conduction/drug effects
- Nociception/drug effects
- Phosphorylation/drug effects
- Rats
- Rats, Wistar
- Receptor, Insulin/metabolism
- Sciatic Nerve/drug effects
- Sciatic Nerve/metabolism
- Sciatic Nerve/physiopathology
- Signal Transduction/drug effects
Collapse
Affiliation(s)
- Kazuhiro Sugimoto
- Department of Laboratory Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
- Diabetes Center, Ohta Nishinouchi Hospital, Koriyama, Japan
| | - Masayuki Baba
- Department of Neurology, Aomori Prefectural Central Hospital, Aomori, Japan
| | - Susumu Suzuki
- Diabetes Center, Ohta Nishinouchi Hospital, Koriyama, Japan
| | - Soroku Yagihashi
- Department of Pathology and Molecular Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| |
Collapse
|
9
|
Abstract
OBJECTIVE Angiotensin (ANG) II type 1 receptor (AT1R) blockers have neuroprotective effects against neuronal lesions. The present study examines whether the AT1R blocker olmesartan improves peripheral nerve dysfunction in rats with type 2 diabetes. METHODS Fourteen-week-old male type 2 diabetic Zucker diabetic fatty (ZDF) rats were orally administered with olmesartan (6 mg/kg per day; n = 7) or not treated (n = 7) and then followed up for nine weeks. Age-matched and sex-matched nondiabetic lean rats served as controls (n = 7). RESULTS Olmesartan for 9 weeks did not influence blood glucose and A1c levels that were higher in untreated ZDF (U-ZDF) rats than in control rats. In U-ZDF rats, myelinated fiber density and myelin areas of myelinated fibers in peroneal nerves significantly increased and decreased, respectively, and the intraepidermal nerve fiber density (IENFD) of footpad skin tended to decrease. The U-ZDF rats developed mechanical hyperalgesia, thermal hypoalgesia and slower sensory and motor nerve conduction in the sciatic-tibial nerves. Olmesartan increased myelin areas and IENFD and ameliorated sensory nerve conduction deficits. These beneficial effects of olmesartan were associated with ANG II and insulin receptor upregulation in sensory neurons as well as deactivation of Erk1/2 in sciatic nerves. CONCLUSION Olmesartan appears to improve the structure and function of small and large nerves and upregulate ANG II and insulin receptors in sensory neurons of rats with type 2 diabetes.
Collapse
|
10
|
Bosco D, Plastino M, Bosco F, Consoli A, Labate A, Pirritano D, Consoli D, Fava A. Bell's palsy: a manifestation of prediabetes? Acta Neurol Scand 2011; 123:68-72. [PMID: 20545630 DOI: 10.1111/j.1600-0404.2010.01365.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Idiopathic peripheral facial nerve palsy or Bell's palsy (BP) is the most common cause of facial nerve palsy. OBJECTIVE To evaluate the role of glucose metabolism abnormalities in BP. METHODS We identified 148 patients with unilateral BP and 128 control subjects. In all we evaluated glucose level at fasting and after a 2-h oral glucose tolerance test (2h-OGTT). In addition we determined insulin resistance (IR), by HOMA-index. Patients and controls were divided in to two groups, according to their Body Mass Index (BMI). RESULTS Following a 2h-OGTT, the prevalence of glucose metabolism abnormalities was significantly higher in patients with BP than in controls (P < 0.001). Impaired glucose tolerance (IGT) was found in 57 (38%) patients and in 23 (18%) controls, while a new-diagnosed DM (NDDM) was found in 29 (19%) patients and in 8 (6%) controls. The IR was significantly increased only in BP patients with BMI ≥ 24.9 (P = 0.005). BMI, waist circumference, blood pressure, tryglicerides, serum lipid, drugs use were not significantly different between patients and controls. CONCLUSIONS In this study we found that prediabetes is frequently associated with facial palsy. We propose to perform a 2h-OGTT in patients with peripheral facial palsy and normal fasting glycaemia. HOMA-index should be evaluated in obese facial palsy patients.
Collapse
Affiliation(s)
- D Bosco
- Department of Neuroscience, S. Giovanni di Dio Hospital, Crotone, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Glucose metabolism in the idiopathic blepharoptosis: Utility of the Oral Glucose Tolerance Test (OGTT) and of the Insulin Resistance Index. J Neurol Sci 2009; 284:24-8. [DOI: 10.1016/j.jns.2009.03.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Revised: 03/01/2009] [Accepted: 03/13/2009] [Indexed: 11/22/2022]
|