Early changes in muscle atrophy and muscle fiber type conversion after spinal cord transection and peripheral nerve transection in rats

Abstract

BackgroundSpinal cord transection and peripheral nerve transection cause muscle atrophy and muscle fiber type conversion. It is still unknown how spinal cord transection and peripheral nerve transection each affect the differentiation of muscle fiber type conversion mechanism and muscle atrophy. The aim of our study was to evaluate the difference of muscle weight change, muscle fiber type conversion, and Peroxisome proliferator-activated receptor-γ coactivatior-1α (PGC-1α) expression brought about by spinal cord transection and by peripheral nerve transection.MethodsTwenty-four Wistar rats underwent surgery, the control rats underwent a laminectomy; the spinal cord injury group underwent a spinal cord transection; the denervation group underwent a sciatic nerve transection. The rats were harvested of the soleus muscle and the TA muscle at 0 week, 1 week and 2 weeks after surgery. Histological examination was assessed using hematoxylin and eosin (H&E) staining and immunofluorescent staing. Western blot was performed with 3 groups.ResultsBoth sciatic nerve transection and spinal cord transection caused muscle atrophy with the effect being more severe after sciatic nerve transection. Spinal cord transection caused a reduction in the expression of both sMHC protein and PGC-1α protein in the soleus muscle. On the other hand, sciatic nerve transection produced an increase in expression of sMHC protein and PGC-1α protein in the soleus muscle. The results of the expression of PGC-1α were expected in other words muscle atrophy after sciatic nerve transection is less than after spinal cord transection, however muscle atrophy after sciatic nerve transection was more severe than after spinal cord transection.ConclusionIn the conclusion, spinal cord transection diminished the expression of sMHC protein and PGC-1α protein in the soleus muscle. On the other hand, sciatic nerve transection enhanced the expression of sMHC protein and PGC-1α protein in the soleus muscle.

Locomotor training with adjuvant testosterone preserves cancellous bone and promotes muscle plasticity in male rats after severe spinal cord injury

“…To gain insight into known regulators of type I fiber expression and mitochondrial status, we evaluated PGC‐1α and PGC‐1β protein expression, which regulate type I fiber gene expression and mitochondrial biogenesis (Kang, Goodman, Hornberger, & Ji, ; Lin et al, ), and mitochondrial function (Gali Ramamoorthy et al, ), respectively. In spinalized rodents, PGC‐1α protein levels are suppressed within two weeks (Higashino et al, ), with 50% lower total and nuclear PGC‐1α protein expression (Wu et al, ) and 50% lower PGC‐1β mRNA (Wu et al, ) persisting for at least 8 weeks. In our primary study, PGC‐1α expression appeared relatively lower at 8 weeks after severe SCI versus SHAM and near‐identical in SCI+TE+TM and SHAM groups, although these differences were not significant and were less pronounced than after spinal transection.…”

Evidence for cervical muscle morphometric changes on magnetic resonance images after whiplash: A systematic review and meta-analysis

“…Karlsson et al [30] included both WAD II and III while Elliott et al [27] included only WAD II. Therefore, morphological changes might be expected to be greater in the group with positive neurological signs (WAD III) but this was not the case [47]. Only 50% of the Matsumoto et al [31] cohort reported head, neck or shoulder pain at 10 year follow-up.…”

Isoquercitrin Delays Denervated Soleus Muscle Atrophy by Inhibiting Oxidative Stress and Inflammation

“…Therefore, in the present study, we established a denervated muscle atrophy model using sciatic nerve disruption in mice, followed by intraperitoneal injection. The atrophy of soleus muscle, containing 98% slow type muscle fibers, was greater affected by sciatic nerve transection as compared to tibialis anterior and extensor digitorum longus muscles (Beehler et al, 2006;Higashino et al, 2013). The wet weight ratio, muscle fiber cross-sectional area (CSA), mitophagy, and muscle fiber type conversion of the soleus muscle were investigated to evaluate the protective effect of isoquercitrin on denervated muscle atrophy.…”