1. Regulation of alternative VEGF-A mRNA splicing is a therapeutic target for analgesia
- Author
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Hulse, RP, Beazley-Long, N, Hua, J, Kennedy, H, Prager, J, Bevan, H, Qiu, Y, Fernandes, ES, Gammons, MV, Ballmer-Hofer, K, Gittenberger de Groot, AC, Churchill, AJ, Harper, SJ, Brain, SD, Bates, DO, and Donaldson, LF
- Subjects
Male ,Pain Threshold ,Vascular Endothelial Growth Factor A ,Sensory Receptor Cells ,DNA, Recombinant ,Neural Conduction ,Alternative mRNA splicing ,TRPV Cation Channels ,Mice, Transgenic ,SRPK1, serine arginine protein kinase 1 ,Antibodies ,Article ,lcsh:RC321-571 ,Mice ,Ganglia, Spinal ,VEGF-A, vascular endothelial growth factor-A ,TRPV1, transient receptor potential vanilloid 1 ,Animals ,RNA, Messenger ,Enzyme Inhibitors ,Rats, Wistar ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Benzofurans ,Pain Measurement ,VEGFR2, vascular endothelial growth factor receptor 2 ,IB4, isolectin B4 ,SRSF1, serine arginine splice factor 1 ,Nociceptors ,Rats ,PSNI, partial saphenous nerve ligation injury ,Neuropathy ,DRG, dorsal root ganglia ,Disease Models, Animal ,Neurology ,Hyperalgesia ,Quinolines ,Neuralgia ,CV, conduction velocity - Abstract
Vascular endothelial growth factor-A (VEGF-A) is best known as a key regulator of the formation of new blood vessels. Neutralization of VEGF-A with anti-VEGF therapy e.g. bevacizumab, can be painful, and this is hypothesized to result from a loss of VEGF-A-mediated neuroprotection. The multiple vegf-a gene products consist of two alternatively spliced families, typified by VEGF-A165a and VEGF-A165b (both contain 165 amino acids), both of which are neuroprotective. Under pathological conditions, such as in inflammation and cancer, the pro-angiogenic VEGF-A165a is upregulated and predominates over the VEGF-A165b isoform. We show here that in rats and mice VEGF-A165a and VEGF-A165b have opposing effects on pain, and that blocking the proximal splicing event – leading to the preferential expression of VEGF-A165b over VEGF165a – prevents pain in vivo. VEGF-A165a sensitizes peripheral nociceptive neurons through actions on VEGFR2 and a TRPV1-dependent mechanism, thus enhancing nociceptive signaling. VEGF-A165b blocks the effect of VEGF-A165a. After nerve injury, the endogenous balance of VEGF-A isoforms switches to greater expression of VEGF-Axxxa compared to VEGF-Axxxb, through an SRPK1-dependent pre-mRNA splicing mechanism. Pharmacological inhibition of SRPK1 after traumatic nerve injury selectively reduced VEGF-Axxxa expression and reversed associated neuropathic pain. Exogenous VEGF-A165b also ameliorated neuropathic pain. We conclude that the relative levels of alternatively spliced VEGF-A isoforms are critical for pain modulation under both normal conditions and in sensory neuropathy. Altering VEGF-Axxxa/VEGF-Axxxb balance by targeting alternative RNA splicing may be a new analgesic strategy., Graphical abstract, Highlights • The different vegf-a splice variants, VEGF-A165a and VEGF-A165b have pro- and anti-nociceptive actions respectively. • Pro-nociceptive actions of VEGF-A165a are dependent on TRPV1. • Alternative pre-mRNA splicing underpins peripheral sensitization by VEGF-A isoforms in normal and neuropathic animals.
- Published
- 2014