Details

Autor(en) / Beteiligte

• Aujla, Paven K.
• Huntley, George W.

Titel

Early postnatal expression and localization of matrix metalloproteinases-2 and -9 during establishment of rat hippocampal synaptic circuitry

Ist Teil von

• Journal of comparative neurology (1911), 2014-04, Vol.522 (6), p.1249-1263

Ort / Verlag

United States: Blackwell Publishing Ltd

Erscheinungsjahr

2014

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• ABSTRACT Matrix metalloproteinases (MMPs) are extracellular proteolytic enzymes that contribute to pericellular remodeling in a variety of tissues, including brain, where they function in adult hippocampal synaptic structural and functional plasticity. Synaptic plasticity and remodeling are also important for development of connectivity, but it is unclear whether MMPs—particularly MMP‐2 and ‐9, the major MMPs operative in brain—contribute at these stages. Here, we use a combination of biochemical and anatomical methods to characterize expression and localization of MMP‐2 and MMP‐9 in early postnatal and adult rat hippocampus. Gene and protein expression of these MMPs were evident throughout hippocampus at all ages examined, but expression levels were highest during the first postnatal week. MMP‐2 and MMP‐9 immunolocalized to punctate structures within the neuropil that codistributed with foci of proteolytic activity, as well as with markers of growing axons and synapses. Taken together, discrete foci of MMP proteolysis are likely important for actively shaping and remodeling cellular and connectional architecture as hippocampal circuitry is becoming established during early postnatal life. J. Comp. Neurol. 522:1249–1263, 2014. © 2013 Wiley Periodicals, Inc. Using biochemical, immunocytochemical, and in situ zymographic methods, the authors show that in developing hippocampus, expression levels of the extracellularly acting proteases matrix metalloproteinase (MMP)‐2 and ‐9 peak during the first postnatal week. At all postnatal ages, MMP‐immunoreactive puncta codistribute with foci of proteolytic activity and with markers of growing axons and synapses. Thus, discrete foci of MMP proteolysis actively shape and remodel cellular and synaptic architecture in developing hippocampus.