( ( Along ( a ( similar vein ) ) ) ( , ( ( ( an epitope ) ( unique ( to ( type ( II collagen ) ) ) ) ) ( ( ( ( ( has ( been ( described ( in ( OA cartilage ) ) ) ) ) , ) and ) ( can ( be ( ( unmasked ( in vitro ) ) ( by ( ( exposing ( normal cartilage ) ) ( to MMPs ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN Along) (NP (DT a) (JJ similar) (NN vein))) (, ,) (NP (NP (DT an) (NN epitope)) (ADJP (JJ unique) (PP (TO to) (NP (NN type) (NNP II) (NNP collagen))))) (VP (VP (VBZ has) (VP (VBN been) (VP (VBN described) (PP (IN in) (NP (NNP OA) (NN cartilage)))))) (, ,) (CC and) (VP (MD can) (VP (VB be) (VP (VBN unmasked) (PP (IN in) (ADJP (NN vitro))) (PP (IN by) (S (VP (VBG exposing) (NP (JJ normal) (NN cartilage)) (PP (TO to) (NP (NNP MMPs)))))))))) (. .)))
Along a similar vein, an epitope unique to type II collagen has been described in OA cartilage, and can be unmasked in vitro by exposing normal cartilage to MMPs.
(ROOT (S (NP (JJ Lamprey) (NN cartilage)) (VP (VBZ contains) (NP (DT no) (NN collagen))) (. .)))