Acta Physiologica 2008; Volume 193, Supplement 664
Scandinavian Physiological Society’s Annual Meeting 2008
COLLAGEN XIII IS A POSTSYNAPTIC, MULTIFUNCTIONAL NEUROMUSCULAR JUNCTION PROTEIN
Abstract number: P35
LATVANLEHTO1 A, FOX1 MA, OIKARAINEN1 T, TU1 H, SORMUNEN1 R, KOSKI1 A, KALLIO1 M, SANES1 JR, PIHLAJANIEMI1 T
1Institute of Biomedicine, Division of Medical Biochemistry and Molecular Biology, Biocenter Oulu, P.O. Box 5000, 90014 University of Oulu, Finland
We have generated two targeted mouse lines; 1) a LacZ reporter line to study the exact location and 2) a null line lacking any collagen XIII expression to study biological function of the transmembrane collagen XIII, also found as a shed, soluble protein.
Methods and results:
Beta-galactosidase marker stainings showed that collagen XIII is highly expressed postsynaptically at the neuromuscular junction (NMJ). The endplate structure in homozygous mice in both lines lacking intact collagen XIII was smaller and more fragmented than that seen in controls. These structural changes were accompanied by an electrophysiologically measurable defect in nerve conduction study. Structural and functional defects of the NMJ had impact on mouse weight, behaviour and general condition. Mice developed myopathy at old age, but yet the structure of NMJs was more disturbed in young than in old mice. It was found that postnatal maturation of the postsynaptic apparatus was delayed and the alignment of pre- and postsynaptic portions was incomplete at some junctions. Recombinant extracellular fragment of collagen XIII had in vitro a minor effect on presynaptic differentiation of motoneurons, but it speeded up the postsynaptic maturation on cultured myotubes.
These studies thus indicate that collagen XIII contributes to stabilization of the NMJ structure and promotes postsynaptic maturation, and this may occur in an autocrine fashion.
To cite this abstract, please use the following information:
Acta Physiologica 2008; Volume 193, Supplement 664 :P35