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F Descalzi Cancedda

Publications and source records attributed to F Descalzi Cancedda.

9 recordsLinked to original sources
PubMed1995

Chondrocyte differentiation.

Data obtained while investigating growth plate chondrocyte differentiation during endochondral bone formation both in vivo and in vitro indicate that initial chondrogenesis depends on positional signaling mediated by selected homeobox-containing genes and soluble mediators. Continuation of the process strongly relies on interactions of the differentiating cells with the microenvironment, that is, other cells and extracellular matrix. Production of and response to different hormones and growth factors are observed at all times and autocrine and paracrine cell stimulations are key elements of the process. Particularly relevant is the role of the TGF-beta superfamily, and more specifically of the BMP subfamily. Other factors include retinoids, FGFs, GH, and IGFs, and perhaps transferrin. The influence of local microenvironment might also offer an acceptable settlement to the debate about whether hypertrophic chondrocytes convert to bone cells and live, or remain chondrocytes and die. We suggest that the ultimate fate of hypertrophic chondrocytes may be different at different microanatomical sites.

Animals↗
PubMed1995

Production of angiogenesis inhibitors and stimulators is modulated by cultured growth plate chondrocytes during in vitro differentiation: dependence on extracellular matrix assembly.

Secretion of angiogenesis inhibitors and stimulators is modulated during in vitro differentiation of embryonic chick growth plate chondrocytes. Supernatants from dedifferentiated cells undergoing maturation to hypertrophic chondrocytes in suspension progressively inhibited vascular cell random migration and invasion of basement membrane matrix by endothelial cells. Maximal inhibition was exhibited by conditioned medium from hypertrophic chondrocytes. The same medium also repressed vascular cell migration induced by highly angiogenic Kaposi's sarcoma cell supernatants and prevented formation of an anastomosed network of tube-like structures by endothelial cells plated on matrigel. On the contrary, when the suspension culture of hypertrophic chondrocytes was supplemented with ascorbic acid, a condition leading to the formation of a mineralized tissue similar to calcified cartilage, a dramatic switch to production of angiogenic activity was observed. Medium conditioned by osteoblast-like cells derived from hypertrophic chondrocytes also induced vascular cell migration and invasion of basement membrane matrix. The presence of angiogenic activity in the conditioned medium was assessed also by an in vivo assay in mice using reconstituted basement membrane associated with heparin. Therefore, interactions of chondrocytes with their extracellular matrix are an absolute requirement for the expression of angiogenic activities by hypertrophic chondrocytes at late developmental stages.

Animals↗
PubMed1992

Hypertrophic chondrocytes undergo further differentiation in culture.

Conditions have been defined for promoting growth and differentiation of hypertrophic chondrocytes obtained in culture starting from chick embryo tibiae. Hypertrophic chondrocytes, grown in suspension culture as described (Castagnola P., G. Moro, F. Descalzi Cancedda, and R. Cancedda. 1986. J. Cell Biol. 102:2310-2317), when they reached the stage of single cells, were transferred to substrate-dependent culture conditions in the presence of ascorbic acid. Cells showed a change in morphology, became more elongated and flattened, expressed alkaline phosphatase, and eventually mineralized. Type II and X collagen synthesis was halted and replaced by type I collagen synthesis. In addition the cells started to produce and to secrete in large amount a protein with an apparent molecular mass of 82 KD in reducing conditions and 63 KD in unreducing conditions. This protein is soluble in acidic solutions, does not contain collagenous domains, and is glycosylated. The Ch21 protein, a marker of hypertrophic chondrocytes and bone cells, was synthesized throughout the culture. We have defined this additional differentiation stage as an osteoblast-like stage. Calcium deposition in the extracellular matrix occurred regardless of the addition of beta glycerophosphate to the culture medium. Comparable results were obtained both when the cells were plated at low density and when they were already at confluence and maintained in culture without passaging up to 50 d. When retinoic acid was added to the hypertrophic chondrocyte culture between day 1 and day 5 the maturation of the cells to the osteoblast-like stage was highly accelerated. The switch in the collagen secretion was already observed after 2 d and the production of the 63-kD protein after 3 d. Mineralization was observed after 15-20 d.

Animals↗
PubMed1992

Chondrogenic differentiation in chick embryo osteoblast cultures.

Expression of specific differentiation markers was investigated by histochemistry, immunofluorescence, and biosynthetic studies in osteoblasts outgrown from chips derived from tibia diaphyses of 18-day-old chick embryos. The starting osteoblast population expressed type I collagen and alkaline phosphatase in addition to other bone and cartilage markers as the lipocalin Ch21; the extracellular matrix deposited by these cells was not stainable for cartilage proteoglycans, and mineralization was observed when the culture was maintained in the presence of ascorbic acid, calcium and beta-glycerophosphate. During culture, clones of cells presenting a polygonal chondrocyte morphology and surrounded by an Alcian-positive matrix appeared in the cell population. Type II collagen and type X collagen were synthesized in these areas of chondrogenesis. In addition, chondrocytes isolated from these cultures expressed Ch21 and alkaline phosphatase. Chondrocytes were generated also from homogeneous osteoblast populations derived from a single cloned cell. The coexistence of chondrocytes and osteoblasts was observed during amplification of primary clones as well as in subclones. The data show the existence, within embryonic bone, of cells capable in vitro of both osteogenic and chondrogenic differentiation.

Alkaline Phosphatase↗
PubMed1990

The amino terminal sequence of the developmentally regulated Ch21 protein shows homology with amino terminal sequences of low molecular weight proteins binding hydrophobic molecules.

Ch21 protein, a developmentally regulated chick embryo protein of 21,000 apparent molecular weight, was purified from culture medium of hypertrophic chondrocytes. The purification method included a DEAE cellulose chromatography column, a CM cellulose chromatography column and a HPLC molecular sieve column. The amino acid sequence of the amino terminal end of the protein was determined. Computer assisted analysis showed significant homology between this sequence and the amino terminal sequences of proteins that belong to the superfamily of the low molecular weight binding proteins sharing a basic framework for the binding and transport of small hydrophobic molecules. Determination of the amino terminal sequence of the chicken retinol binding protein excluded identity between this protein and the Ch21.

Amino Acid Sequence↗
PubMed1989

Synthesis and secretion of Ch 21 protein in embryonic chick skeletal tissues.

We reported the identification, purification and characterization of a low molecular weight protein (Ch 21) expressed in vitro by differentiating chondrocytes at a late stage of development and observed in vivo in the growth plate region of the long bones at the border between hypertrophic cartilage and newly formed bone (Descalzi Cancedda, F., P. Manduca, C. Tacchetti, P. Fossa, R. Quarto, R. Cancedda, J. Cell Biol. 107, 2455-2463 (1988]. In this article, the synthesis and location of Ch 21 protein in the chick embryo tibia at late stage of development were further investigated. Ch 21 was observed in the cartilage matrix surrounding marrow cavities and in the prearticular outer layer by immunolocalization. In addition, the timing of Ch 21 appearance during the tibia development and its distribution in the growth plate region was better defined. We first observed presence of Ch 21 in the perichondral mid-diaphyseal sleeve of 7-day-old tibia. Ch 21 antibodies stained also the newly formed bone. Synthesis and secretion in the culture medium of Ch 21 protein was observed when bone fragments or cultured osteoblasts isolated from 19-day-old embryo tibiae were labeled in vitro. A search for the presence of Ch 21 in the chick embryo sternum was performed. The synthesis of Ch 21, both in the presumptive calcification cranial portion and in the permanent cartilaginous caudal portion of the sternum, was shown by metabolic labeling of tissue slices.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Developmentally regulated synthesis of a low molecular weight protein (Ch 21) by differentiating chondrocytes.

When transferred to suspension culture on agarose-coated dishes, dedifferentiated chick embryo chondrocytes resume the chondrocyte phenotype and continue their maturation to hypertrophic chondrocytes (Castagnola, P., G. Moro, F. Descalzi Cancedda, and R. Cancedda. 1986. J. Cell Biol. 102:2310-2317). In this paper we report the identification, purification, and characterization of a low molecular weight protein, named Ch 21, expressed and secreted by in vitro differentiating chondrocytes at a late stage of development. This protein is detectable in the cells after a short pulse labeling and is directly secreted in the culture medium. The Ch 21 protein has a peculiar resistance to limited pepsin digestion; nevertheless it is not collagenous in nature as revealed by its unaltered mobility when isolated from cells grown in the presence of alpha-alpha' dipyridyl, its resistance to bacterial collagenase, and its amino acid composition. By metabolic labeling of tissue slices and by immunohistochemistry, we show that in the chick embryo tibia the Ch 21 protein first appears at the boundary of the cone of hypertrophic cartilage and in the newly formed bone between the 6 and 10 d of embryo development and localizes in calcifying hypertrophic cartilage thereafter. The Ch 21 protein synthesized by the cultured chondrocytes is closely related and possibly identical to a 21K transformation-sensitive protein associated to the cell substratum of chick embryo fibroblasts.

Age Factors↗
PubMed1986

In vitro translation of chicken type X collagen in the presence of pancreas microsomes.

Total RNA from epiphysis of 17-day-old chick embryo tibiae was used to direct protein synthesis in a wheat germ cell free system. The type X collagen chain, identified on the basis of its electrophoretic migration and of peptides obtained by S. aureus V8 protease digestion, was the major translation product. The newly synthesized chain included a signal sequence that was removed when dog pancreas membranes were added at the time of the protein synthesis.

Animals↗