title: Selective targeting of ASIC3 using artificial miRNAs inhibits primary and secondary hyperalgesia after muscle inflammation.
abstract: Acid-sensing ion channels (ASICs) are activated by acidic pH and may play a significant role in the development of hyperalgesia. Earlier studies show ASIC3 is important for induction of hyperalgesia after muscle insult using ASIC3-/- mice. ASIC3-/- mice lack ASIC3 throughout the body, and the distribution and composition of ASICs could be different from wild-type mice. We therefore tested whether knockdown of ASIC3 in primary afferents innervating muscle of adult wild-type mice prevented development of hyperalgesia to muscle inflammation. We cloned and characterized artificial miRNAs (miR-ASIC3) directed against mouse ASIC3 (mASIC3) to downregulate ASIC3 expression in vitro and in vivo. In CHO-K1 cells transfected with mASIC3 cDNA in culture, the miR-ASIC3 constructs inhibited protein expression of mASIC3 and acidic pH-evoked currents and had no effect on protein expression or acidic pH-evoked currents of ASIC1a. When miR-ASIC3 was used in vivo, delivered into the muscle of mice using a herpes simplex viral vector, both muscle and paw mechanical hyperalgesia were reduced after carrageenan-induced muscle inflammation. ASIC3 mRNA in DRG and protein levels in muscle were decreased in vivo by miR-ASIC3. In CHO-K1 cells co-transfected with ASIC1a and ASIC3, miR-ASIC3 reduced the amplitude of acidic pH-evoked currents, suggesting an overall inhibition in the surface expression of heteromeric ASIC3-containing channels. Our results show, for the first time, that reducing ASIC3 in vivo in primary afferent fibers innervating muscle prevents the development of inflammatory hyperalgesia in wild-type mice, and thus, may have applications in the treatment of musculoskeletal pain in humans.
authors.affiliation: Physical Therapy and Rehabilitation Sciences Graduate Program, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, IA, USA Neuroscience Graduate Program, Pain Research Program, The University of Iowa, Iowa City, IA, USA Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, USA Department of Internal Medicine, Pain Research Program, Roy J. and Lucille A. Carver College of Medicine, The University of Iowa, Iowa City, IA, USA.
authors.forename: Roxanne Y
authors.initials: RY
authors.lastname: Walder
authors.forename: Mamta
authors.initials: M
authors.lastname: Gautam
authors.forename: Steven P
authors.initials: SP
authors.lastname: Wilson
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Benson
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Sluka
mesh_terms: D062565:Acid Sensing Ion Channels; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004195:Disease Models, Animal; D018390:Gene Targeting / Q000379:methods*; D015316:Genetic Therapy / Q000379:methods; D006930:Hyperalgesia / Q000235:genetics / Q000473:pathology / Q000517:prevention & control*; D018836:Inflammation Mediators / Q000138:chemical synthesis / Q000502:physiology / Q000627:therapeutic use; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D035683:MicroRNAs / Q000138:chemical synthesis / Q000494:pharmacology* / Q000627:therapeutic use; D059352:Musculoskeletal Pain / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D009220:Myositis / Q000150:complications / Q000235:genetics* / Q000473:pathology; D015222:Sodium Channels / Q000172:deficiency / Q000235:genetics* / Q000502:physiology
chemical_list: C508378:ASIC3 protein, mouse; D062565:Acid Sensing Ion Channels; D018836:Inflammation Mediators; D035683:MicroRNAs; D015222:Sodium Channels