The expression and role of Lysyl oxidase (LOX) in dentinogenesis. (28th November 2012)

• Record Type: Journal Article
• Authors: Tjäderhane, L.; Vered, M.; Pääkkönen, V.; Peteri, A.; Mäki, J. M.; Myllyharju, J.; Dayan, D.; Salo, T.
• Is Part Of: International endontic journal. Volume 46:Number 6(2013:Jun.)
• Page Start: 581
• Page End: 589
• Publication Date: 2012-11-28
• Subjects: Endodontics -- Periodicals; 617.6342
• DOI: 10.1111/iej.12031
• Languages: English
• ISSNs: 0143-2885

Abstract

<abstract abstract-type="main" id="iej12031-abs-0001"> <title>Abstract</title> <sec id="iej12031-sec-0001" sec-type="section"> <title>Aim</title> <p>To establish whether eliminating Lysyl oxidase (LOX) gene would affect dentine formation.</p> </sec> <sec id="iej12031-sec-0002" sec-type="section"> <title>Methodology</title> <p>Newborn wild‐type (<italic>wt</italic>) and homo‐ and heterozygous LOX knock‐out (<italic>Lox</italic><sup><italic>−/−</italic></sup> and <italic>Lox</italic><sup><italic>+/−</italic></sup>, respectively) mice were used to study developing tooth morphology and dentine formation. Collagen aggregation in the developing dentine was examined histochemically with picrosirius red (PSR) staining followed by polarized microscopy. Because <italic>Lox</italic><sup><italic>−/−</italic></sup> die at birth, adult <italic>wt</italic> and <italic>Lox</italic><sup><italic>+/−</italic></sup> mouse tooth morphologies were examined with FESEM. Human odontoblasts and pulp tissue were used to study the expression of LOX and its isoenzymes with Affymetrix cDNA microarray.</p> </sec> <sec id="iej12031-sec-0003" sec-type="section"> <title>Results</title> <p>No differences between <italic>Lox</italic><sup><italic>−/−</italic></sup>, <italic>Lox</italic><sup><italic>+/−</italic></sup> and <italic>wt</italic> mice developing tooth morphology were seen by light microscopy. Histochemically, however, teeth in <italic>wt</italic> mice demonstrated yellow‐orange and orange‐red polarization colours with PSR staining, indicating thick and more densely packed collagen fibres, whilst in <italic>Lox</italic><sup><italic>−/−</italic></sup> and <italic>Lox</italic><sup><italic>+/−</italic></sup> mice, most of the polarization colours were green to green‐yellow, indicating thinner, less aggregated collagen fibres. Fully developed teeth did not show any differences between <italic>Lox</italic><sup><italic>+/−</italic></sup> and <italic>wt</italic> mice with FESEM. Human odontoblasts expressed LOX and three of four of its isoenzymes.</p> </sec> <sec id="iej12031-sec-0004" sec-type="section"> <title>Conclusions</title> <p>The data indicate that LOX is not essential in dentinogenesis, even though LOX deletion may affect dentine matrix collagen thickness and packing. The absence of functional LOX may be compensated by LOX isoenzymes.</p> </sec> </abstract>