Co-distribution of cysteine cathepsins and matrix metalloproteases in human dentin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) It has been hypothesized that cysteine cathepsins (CTs) along with matrix metalloproteases (MMPs) may work in conjunction in the proteolysis of mature dentin matrix. The aim of this study was to verify simultaneously the distribution and presence of cathepsins B (CT-B) and K (CT-K) in partially demineralized dentin; and further to evaluate the activity of CTs and MMPs in the same tissue. The distribution of CT-B and CT-K in sound human dentin was assessed by immunohistochemistry. A double-immunolabeling technique was used to identify, at once, the occurrence of those enzymes in dentin. Activities of CTs and MMPs in dentin extracts were evaluated spectrofluorometrically. In addition, in situ gelatinolytic activity of dentin was assayed by zymography. The results revealed the distribution of CT-B and CT-K along the dentin organic matrix and also indicated co-occurrence of MMPs and CTs in that tissue. The enzyme kinetics studies showed proteolytic activity in dentin extracts for both classes of proteases. Furthermore, it was observed that, at least for sound human dentin matrices, the activity of MMPs seems to be predominant over the CTs one. Univ Estadual Campinas, Fac Dent Piracicaba, BR-13414903 Piracicaba, Brazil Univ Sao Paulo, Bauru Sch Dent, Dept Biol Sci, BR-17012901 Bauru, SP, Brazil Univ Bologna, Dept Biomed & Neuromotor Sci, I-40126 Bologna, Italy Univ Trieste, Dept Med Sci, I-34128 Trieste, Italy Univ Iowa, Coll Dent, Dept Operat Dent, 801 Newton Rd, Iowa City, IA 52246 USA CNR, IGM, Unit Bologna, IOR, I-40136 Bologna, Italy Univ Fed Ceara, Dept Pharm Dent & Nursing, BR-60020181 Fortaleza, Ceara, Brazil Univ Carlo Bo, Dept SteVA, I-61029 Urbino, Italy Georgia Hlth Sci Univ, Dent Coll Georgia, Oral Biol, Augusta, GA 30912 USA Univ Oulu, Inst Dent, FI-90014 Oulu, Finland Oulu Univ Hosp, Med Res Ctr Oulu, FI-90014 Oulu, Finland Univ Oulu, FI-90014 Oulu, Finland Univ Helsinki, Dept Oral & Maxillofacial Dis, FI-00014 Helsinki, Finland Helsinki Univ Hosp, FI-00014 Helsinki, Finland Univ Fed Sao Paulo, Dept Biochem, BR-04021001 Sao Paulo, Brazil Univ Mogi das Cruzes, Ctr Interdisciplinar Invest Bioquim, BR-08773520 Mogi Das Cruzes, Brazil Anhanguera Univ Sao Paulo UNIAN SP, Biomat Dent Program, BR-05145200 Sao Paulo, Brazil Anhanguera Univ Sao Paulo UNIAN SP, Biotechnol & Innovat Hlth Program, BR-05145200 Sao Paulo, Brazil Univ Fed Sao Paulo, Dept Biochem, BR-04021001 Sao Paulo, Brazil FAPESP: 2007/54618-4 FAPESP: 2009/14005-9 CNPq: 312768/2013-3 Web of Science