Enzyme Histochemistry of Bone Induction by Urinary Bladder Epithelium

Abstract

Homogenous transplants of urinary bladder mucosa were made in guinea pigs, and induced bone formation was observed histochemically for alkaline phosphatase, acid phosphatase, esterase, β-glucuronidase, aminopeptidase, and oxidative enzymes, i.e., succinic dehydrogenase, diphosphopyridine nucleotide-dependent dehydrogenase (lactate, malate, glutamate, α-glycerophosphate, β-hydroxybutyrate) and triphosphopyridine nucleotide-dependent dehydrogenase (glucose-6-phosphate and isocitrate). Normal urinary bladder epithelium contained intense alkaline phosphatase and slight acid phosphatase activity throughout. There was weak esterase activity in intermediate layer and weak β-glucuronidase activity in intermediate layer. Succinic dehydrogenase was present throughout the epithelium, and was most active in the basal layer. Lactic and malic dehydrogenase activities were intense. Glutamic, α-glycerophosphate and β-hydroxybutyric dehydrogenase activities were low, but glucose-6-phosphate and isocitric dehydrogenase activities were high. In the initial stage after transplantation, alkaline phosphatase, aminopeptidase and lactic dehydrogenase appeared in the connective tissue surrounding the transplanted mucosa in association with an inflammatory infiltration. Epithelial transplants formed cysts. Lactic, malic and triphosphopyridine nucleotide-dependent dehydrogenases in cystic epithelium were as intense as in normal bladder, though other enzymes decreased. Hyaline formation occurred around the cyst. No appreciable enzyme activity was demonstrated in this hyalinized portion, but when bone appeared marked activity of alkaline and acid phosphatases was seen around it. Histochemical patterns in the induced bone were essentially the same as in normal bone.

Heterotopic bone formation in tumor stromal tissue. Immunohistochemical considerations.

“…These conditions might participate in either normal bone formation in skeletal tissue or heterotopic ossification. Bone induction is known to occur in transplanted bladder epithelium, and epithelial structures and basement membrane are probably involved actively in this induction (6,12,15).…”

“…In the case of heterotopic ossification, there are no preceding lesions, whereas in metaplastic bone formation, there are preexisting lesions. Examples o£ heterotopic ossification are osteoma cutis (2,11,14), Albright's syndrome ossification (3), calcifying epithelioma Malherbe (16), stromal ossification in tumors of the ovary, kidney and breast (1,(8)(9)(10), and also experimental bone induction in transplanted bladder mucosa (6,12,15).…”

Glycosaminoglycan Distribution in Chondro-Osteogenesis Induced by Bone Morphogenetic Protein in Mouse Muscle Tissue with the Use of Monoclonal Antibodies.

“…Thus, GAGs were found to occur specifically in the 1st stage of the BMP-implanted area. Fibrous or metaplastic ossification was reported to occur in connective tissue cells as seen in tumor stromal ossification (15,16,18,21) or experimental bone induction by urinary bladder transplantation (7,11). It is significant that BMP does not directly induce the replacement of bone tissues, but BMP directly induces the proliferation of neighboring undifferentiated mesenchyme cells, and these cells then induce chondroidal metaplasia.…”

“…Experimental bone induction has likewise been described in urinary bladder transplantation (7,11). The mechanism underlying bone induction is probably related to metaplastic processes from nonspecific mesenchymal cells.…”

Multifunctional roles of growth factors or biologically active peptides in salivary glands and saliva

“…BMP-7 is also an osteogenic protein. Heterotopic bone formation occurs in non-osteogenetic tissues; for instance, BMP transplanted in urinary bladder epithelium results in bone induction (48)(49), and enzyme histochemical studies on such heterotopic bone formation have been evaluated (50). Ectopic or heterotopic ossification are also seen in tumors such as osteoma cutis, osteoma of the tongue, and bone formation in calcifying epithelioma of Malherbe (51), and stromal ossification of the breast and salivary gland tumors are not uncommon.…”