Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.23.5 (cathepsin D)
 4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Young rats, fed a low calcium and vitamin D deficient diet for 2 weeks, developed hypocalcemia, an increased activity of serum alkaline phosphatase and an increase in the serum concentration of immunoreactive parathyroid hormone. An increased activity of lactate dehydrogenase and cytochrome oxidase in odontoblasts was found. No shift in the general energy metabolic pathway was found as visualized in the lactate dehydrogenase iso-enzyme pattern. The dominating lactate dehydrogenase isoenzyme in odontoblasts from both the normal and the deficient rats was LDH 1 (H4, LD5), thus indicating primarily an aerobic energy-metabolism Also the activities of the lysosomal enzymes acid phosphatase, cathepsin D and hyaluronidase in the odontoblasts from the deficient animals were increased when compared to the normal animals. No significant change could be demonstrated for beta-glucuronidase and beta-N-acetylglucosaminidase. It was earlier found that this deficient diet caused an increase in odontoblast alkaline phosphatase activities and protein synthesis in vitro. In view of the present findings it might be concluded that the low calcium and vitamin D deficient diet causes a general increase in the odontoblast metabolism. It is not known whether this is due to the increase in parathyroid hormone or if it is a direct effect of the lowered serum calcium concentration.
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PMID:Odontoblast metabolism in rats deficient in vitamin D and calcium. IV. Lysosomal and energy metabolic enzymes. 625 18

X-linked hypophosphatemia (XLH), the most common form of hereditary rickets, is caused by loss-of-function mutations of PHEX gene in osteoblast cells, leading to rachitic bone disease and hypophosphatemia. Available evidence today indicates that the bone defect in XLH is caused not only by hypophosphatemia and altered vitamin D metabolism, but also by locally released osteoblastic mineralization inhibitory factor(s), referred to as minhibin. In our present study, we found that suppression of PHEX expression by PHEX antisense in human osteoblast cells caused an increase in cathepsin D expression at protein, but not mRNA, levels. This was associated with a decrease in cathepsin D degradation and an increased cathepsin D release into culture media. Our results also showed that lowering cathepsin D activity in antisense cell conditioned media abolished their inhibitory effect on osteoblast cell calcification, suggesting the involvement of cathepsin D in mediating the minhibin activity of the antisense cell conditioned media.
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PMID:Altered cathepsin D metabolism in PHEX antisense human osteoblast cells. 1589 24