Effects of electroacupuncture and the retinoid X receptor (RXR) signalling pathway on oligodendrocyte differentiation in the demyelinated spinal cord of rats

• Published in: Acupuncture in medicine : journal of the British Medical Acupuncture Society 2017-04, Vol.35 (2), p.122-132
• Main Authors: Yang, Xiao-Hua, Ding, Ying, Li, Wen, Zhang, Rong-Yi, Wu, Jin-Lang, Ling, Eng-Ang, Wu, Wutian, Zeng, Yuan-shan
• Format: Article
• Language: English
• Subjects: Acids; Animals; Cell Differentiation; Demyelinating Diseases - metabolism; Demyelinating Diseases - therapy; Electroacupuncture; Female; Gene expression; Humans; Laboratory animals; Multiple sclerosis; Oligodendroglia - cytology; Oligodendroglia - metabolism; Original Paper; Rats; Rats, Sprague-Dawley; Retinoid X Receptors - metabolism; Rodents; Signal Transduction; Spinal cord; Spinal Cord - metabolism; Stem cells; Surgery
• ISSN: 0964-5284; 1759-9873
• DOI: 10.1136/acupmed-2016-011134

ObjectivesIn spinal cord demyelination, some oligodendrocyte precursor cells (OPCs) remain in the demyelinated region but have a reduced capacity to differentiate into oligodendrocytes. This study investigated whether ‘Governor Vessel’ (GV) electroacupuncture (EA) would promote the differentiation of endogenous OPCs into oligodendrocytes by activating the retinoid X receptor γ (RXR-γ)-mediated signalling pathway.MethodsAdult rats were microinjected with ethidium bromide (EB) into the T10 spinal cord to establish a model of spinal cord demyelination. EB-injected rats remained untreated (EB group, n=26) or received EA treatment (EB+EA group, n=26). A control group (n=26) was also included that underwent dural exposure without EB injection. After euthanasia at 7 days (n=5 per group), 15 days (n=8 per group) or 30 days (n=13 per group), protein expression of RXR-γ in the demyelinated spinal cord was evaluated by immunohistochemistry and Western blotting. In addition, OPCs derived from rat embryonic spinal cord were cultured in vitro, and exogenous 9-cis-RA (retinoic acid) and RXR-γ antagonist HX531 were administered to determine whether RA could activate RXR-γ and promote OPC differentiation.ResultsEA was found to increase the numbers of both OPCs and oligodendrocytes expressing RXR-γ and RALDH2, and promote remyelination in the remyelinated spinal cord. Exogenous 9-cis-RA enhanced the differentiation of OPCs into mature oligodendrocytes by activating RXR-γ.ConclusionsThe results suggest that EA may activate RXR signalling to promote the differentiation of OPCs into oligodendrocytes in spinal cord demyelination.