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  • Scarabello Stape, Thiago Henrique; Tjäderhane, Leo; Tezvergil-Mutluay, Arzu; Da Silva, Wagner Gomes; dos Santos Silva, Alan Roger; da Silva, Wander Jose; Marques, Marcelo Rocha (2018)
    Matrix metalloproteinases (MMPs) such as gelatinases are differentially expressed in human tissues. These enzymes cleave specific substrates involved in cell signaling, tissue development and remodeling and tissue breakdown. Recent evidences show that gelatinases are crucial for normal dentin development and their activity is maintained throughout the entire tooth function in the oral cavity. Due to the lack of information about the exact location and activity of gelatinases in mature human dentin, the present study was designed to examine gelatinolytic levels In sound dentin. In situ zymography using confocal microscopy was performed on both mineralized and demineralized dentin samples. Sites presenting gelatinase activity were identified throughout the entire biological tissue pursuing different gelatinolytic levels for distinct areas: predentin and dentinal tubule regions presented higher gelatinolytic activity compared to intertubular dentin. Dentin regions with higher gelatinolytic activity immunohistochemically were partially correlated with MMP-2 expression. The maintenance of gelatinolytic activity in mature dentin may have biological implications related to biomineralization of predentin and tubular/peritubular dentinal regions, as well as regulation of defensive mechanisms of the dentin-pulp complex.
  • Salmenkari, Hanne; Issakainen, Tomi; Vapaatalo, Heikki; Korpela, Riitta (2015)
    AIM: To investigate local corticosterone production and angiotensin- I converting enzyme (ACE) protein expression and their interaction in healthy and inflamed intestine. METHODS: Acute intestinal inflammation was induced to six weeks old male Balb/c mice by administration of either 3% or 5% dextran sodium sulfate (DSS) in drinking water for 7 d (n = 12 in each group). Healthy controls (n = 12) were given tap water. Corticosterone production and ACE protein shedding were measured from ex vivo incubates of the small and large intestine using EIA and ELISA, respectively. Morphological changes of the intestinal wall were assessed in hematoxylin-eosin stained tissue preparations of jejunum and distal colon. Effects of angiotensin II, captopril and metyrapone on corticosterone production was assessed by incubating pieces of small intestine of healthy mice in the presence of 0.1, 1 or 10 mu mol/L angiotensin II, 1, 10 or 100 mu mol/L captopril or 1, 10 or 100 mu mol/L metyrapone solutions and measuring corticosterone released to the incubation buffer after 90 min (n = 5 in each group). RESULTS: Both concentrations of DSS induced inflammation and morphological changes in large intestines but not in small intestines. Changes were observed as distortions of the crypt structure, mucosal erosion, immune cell infiltration to the mucosa and submucosal edema. Ex vivo corticosterone production (2.9 +/- 1.0 ng/mL vs 2.0 +/- 0.8 ng/mL, P = 0.034) and ACE shedding (269.2 +/- 97.1 ng/mL vs 175.7 +/- 52.2 ng/mL, P = 0.016) were increased in small intestines in 3% DSS group compared to the controls. In large intestine, corticosterone production was increased compared to the controls in both 3% DSS (229 +/- 81 pg/mL vs 158 +/- 30 pg/mL, P = 0.017) and 5% DSS groups (366 +/- 163 pg/mL vs 158 +/- 30 pg/mL, P = 0.002). Large intestine ACE shedding was increased in 5% DSS group (41.5 +/- 9.0 ng/mL vs 20.9 +/- 5.2 ng/mL, P = 0.034). Angiotensin II treatment augmented corticosterone production in small intestine at concentration of 10 mu mol/L (0.97 +/- 0.21 ng/mg protein vs 0.40 +/- 0.09 ng/mg protein, P = 0.036). CONCLUSION: Intestinal ACE shedding is increased by DSS-induced intestinal inflammation and parallels local corticosterone production. ACE product angiotensin. stimulates corticosterone formation in healthy intestine.