Nerve growth factor gene therapy improves bone marrow sensory innervation and nociceptor-mediated stem cell release in a mouse model of type 1 diabetes with limb ischaemia

• Published in: Diabetologia 2019-07, Vol.62 (7), p.1297-1311
• Main Authors: Dang, Zexu, Avolio, Elisa, Albertario, Ambra, Sala-Newby, Graciela B., Thomas, Anita C., Wang, Nianhong, Emanueli, Costanza, Madeddu, Paolo
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis; Axonogenesis; Blood flow; Bone healing; Bone Marrow; Denervation; Diabetes; Diabetes mellitus; Diabetes mellitus (insulin dependent); Diabetes mellitus (non-insulin dependent); Diabetes Mellitus, Experimental - metabolism; Diabetes Mellitus, Experimental - therapy; Diabetes Mellitus, Type 1 - metabolism; Diabetes Mellitus, Type 1 - therapy; Diabetic neuropathy; Gene therapy; Genetic Therapy - methods; Growth factors; Human Physiology; Immunohistochemistry; Innervation; Internal Medicine; Ischemia; Ischemia - therapy; Male; Medicine; Medicine & Public Health; Metabolic Diseases; Mice; Nerve growth factor; Nerve Growth Factor - metabolism; Neurokinin; Neurokinin NK1 receptors; Nociceptors; Pain perception; Sensory neurons; Sensory Receptor Cells - cytology; Sensory Receptor Cells - metabolism; Signal transduction; Stem cells; Stem Cells - cytology; Stem Cells - metabolism; β-Galactosidase
• ISSN: 0012-186X; 1432-0428
• DOI: 10.1007/s00125-019-4860-y

Aims/hypothesis Sensory neuropathy is common in people with diabetes; neuropathy can also affect the bone marrow of individuals with type 2 diabetes. However, no information exists on the state of bone marrow sensory innervation in type 1 diabetes. Sensory neurons are trophically dependent on nerve growth factor (NGF) for their survival. The aim of this investigation was twofold: (1) to determine if sensory neuropathy affects the bone marrow in a mouse model of type 1 diabetes, with consequences for stem cell liberation after tissue injury; and (2) to verify if a single systemic injection of the NGF gene exerts long-term beneficial effects on these phenomena. Methods A mouse model of type 1 diabetes was generated in CD1 mice by administration of streptozotocin; vehicle was administered to non-diabetic control animals. Diabetic animals were randomised to receive systemic gene therapy with either human NGF or β-galactosidase. After 13 weeks, limb ischaemia was induced in both groups to study the recovery post injury. When the animals were killed, samples of tissue and peripheral blood were taken to assess stem cell mobilisation and homing, levels of substance P and muscle vascularisation. An in vitro cellular model was adopted to verify signalling downstream to human NGF and related neurotrophic or pro-apoptotic effects. Normally distributed variables were compared between groups using the unpaired Student’s t test and non-normally distributed variables were assessed by the Wilcoxon–Mann–Whitney test. The Fisher’s exact test was employed for categorical variables. Results Immunohistochemistry indicated a 3.3-fold reduction in the number of substance P-positive nociceptive fibres in the bone marrow of type 1 diabetic mice ( p