Spinal cord injury (SCI) animal model

All experimental procedures were conducted in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals and the animal use protocol, reviewed and approved by the Institutional Animal Use and Care Committee at the University of Nevada. All methods are reported in accordance with ARRIVE guidelines. C57BL/6 (male mice, 8–12 wks old), Pdgfra^{tm11(EGFP)Sor}/J (PDGFRα/eGFP, Jackson lab) and smMHC/Cre/eGFP (SMC/eGFP) from Jackson Lab used for SCI operations and age-matched control. Laminectomies were performed under isoflurane anesthesia (3—4% with a balance of oxygen for induction followed by 2% for maintenance), and the spinal cord (T11–T13) were exposed without any damage or compression to the surrounding dura. Dumont #5 forceps were positioned in the middle of the exposed spinal cord segment to perform complete spinal cord transection. Complete spinal cord transection was done at T 12 confirmed by retraction of rostal and caudal cut ends of spinal cord under surgical microscope, which had a space approximately at 2 mm. Control animals received sham operations with exposing the vertebrae at same level as SCI without damaging any spinal cord and dura. Enrofloxacin (5 mg/kg) was applied subcutaneously for three days after SCI followed by twice a week after SCI surgery until ex vivo or molecular evaluation was done. The bladder was manually squeezed to eliminate the residual urine of bladder once daily. Bladders were collected for experiments at D1, D3, D7, D14 and D30 after SCI surgery and in sham control.