Avtor/Urednik		Trinkaus, M; Pregelj, P; Trkov, S; Sketelj, J
Naslov		Neural regulation of acetylcholinesterase-associated collagen Q in rat skeletal muscles
Tip		članek
Vir		J Neurochem
Vol. in št.		Letnik 105
Leto izdaje		2008
Obseg		str. 2535-44
Jezik		eng
Abstrakt		Acetylcholinesterase-associated collagen Q is expressed also outside of neuromuscular junctions in the slow soleus muscle, but not in fast muscles. We examined the nerve dependence of muscle collagen Q expression and mechanisms responsible for these differences. Denervation decreased extrajunctional collagen Q mRNA levels in the soleus muscles and junctional levels in fast sternomastoid muscles to about one third. Cross-innervation of denervated soleus muscles by a fast muscle nerve, or electrical stimulation by 'fast' impulse pattern, reduced their extrajunctional collagen Q mRNA levels by 70-80%. In contrast, stimulation of fast muscles by 'slow' impulse pattern had no effect on collagen Q expression. Calcineurin inhibitors tacrolimus and cyclosporin A decreased collagen Q mRNA levels in the soleus muscles to about 35%, but did not affect collagen Q expression in denervated soleus muscles or the junctional expression in fast muscles. Therefore, high extrajunctional expression of collagen Q in the soleus muscle is maintained by its tonic nerve-induced activation pattern via the activated Ca(2+)-calcineurin signaling pathway. The extrajunctional collagen Q expression in fast muscles is independent of muscle activation pattern and seems irreversibly suppressed. The junctional expression of collagen Q in fast muscles is partly nerve-dependent, but does not encompass the Ca(2+)-calcineurin signaling pathway.
Deskriptorji		ACETYLCHOLINESTERASE COLLAGEN MUSCLE, SKELETAL NEUROMUSCULAR JUNCTION MUSCLE DENERVATION RNA, MESSENGER ELECTRIC STIMULATION TACROLIMUS CYCLOSPORINE POLYMERASE CHAIN REACTION RATS