Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of aluminum on the bone inductive properties of implanted bone matrix was studied in rats. After decalcification femur sections were placed in either 0.1 or 0.01 M AlCl3 or a solution of similar pH without Al for 24 hours. Following 28 days of implantation in subcutaneous pouches the aluminum content was 3232 +/- 1020 and 51 +/- 6 mg/kg in the matrix pretreated with 0.1 and 0.01 M AlCl3. At the same time period following implantation the matrix calcium content was 794 +/- 539 and 3038 +/- 692 mmol/kg in the 0.1 and 0.01 M AlCl3 pretreated groups versus 4252 +/- 579 mmol/kg in the control group (P less than 0.01). In the control group bone histology showed extensive osteoblastic and osteoclastic remodeling, tetracycline labeling and bone formation. In contrast all of these histological features were virtually absent in aluminum treated matrix. Aluminum-induced resistance of bone matrix to collagenase degradation and restoration of bone inductive properties with chelation suggests that aluminum forms intermolecular cross links between collagen fibrils. Aluminum-induced cross links of collagen fibrils and/or its effects on bone inductive proteins present in bone matrix could explain the mechanism by which aluminum induces osteomalacia.
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PMID:Effect of aluminum on bone matrix inductive properties. 207 56

The mechanism of aluminum-induced bone disease was studied by experiments in vitro and in rats. After decalcification femur sections were treated with 0.1 M AlCl3 and implanted with control bone matrices into weanling male rats. After 4 or 8 weeks of implantation the tissue values of calcium(Ca), phosphorus(P) and aluminum(Al) were measured. The results showed that both Ca and P values in Al-treated bones were obviously lower than those of the controls (P less than 0.01), Al level in these bones remained considerably high. Histological examination indicated that aluminum deposited diffusely in Al-treated bones, the bone formation rate and mineralization rate markedly decreased, osteoclastic and osteoblastic activities were also inhibited. In collagenase incubation test the bone matrices pretreated with different concentrations of AlCl3 showed different degrees of resistance to digestion of collagenase. It is considered that aluminum forms tight complexes with bone collagen causing cross linkage and destroying the inductive effect in bone matrix, thus leading to aluminum-induced bone disease. Our study also suggests that the usage of chelating agents can remove aluminum from matrix and recover its abilities of bone formation and mineralization.
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PMID:[Experimental study of the mechanism of aluminum-induced bone disease]. 208 19

Cathepsin L (CTSL) is a lysosomal cysteine protease with potent elastase and collagenase activities. Its high activity in the uterine lumen during the period of placental attachment has led to speculation that CTSL may play an important role during embryonic implantation in the pig. Cathepsins have also been implicated in blastocyst implantation in other species like cat, rat and man. We isolated a PAC clone containing the porcine CTSL gene and determined the complete DNA sequence of the gene, which spans about 5.6 kb and consists of eight exons. The CTSL transcript encodes a primary peptide of 334 amino acids sharing 73-78% identity with other mammalian cathepsin L precursor proteins. Based on fluorescence in situ hybridization and radiation hybrid mapping, the porcine CTSL gene was assigned to chromosome 10q11--> q12.
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PMID:Characterization and comparative mapping of the porcine CTSL gene indicates a novel synteny between HSA9q21-->q22 and SSC10q11-->q12. 1197 77