A Histomorphometric, Structural, and Immunocytochemical Study of the Effects of Diet-induced Hypocalcemia on Bone in Growing Rats

Mocetti, P.; Ballanti, P.; Zalzal, S.; Silvestrini, G.; Bonucci, E.; Nanci, Antonio

doi:10.1177/002215540004800804

Cited by 25 publications

(12 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One pathological alteration we have examined using immunocytochemistry is the bone matrix calcification defects during diet-induced hypocalcemia which are similar to those observed in rickets and osteomalacia (Mocetti et al 2000). There were no major changes in the pattern of protein distribution of BSP, osteocalcin, and OPN or concentration at labeled sites that could be inferred from qualitative observation.…”

Section: Pathological and Drugs Alterations Of Protein Distributionmentioning

confidence: 66%

Immunocytochemistry of matrix proteins in calcified tissues: functional biochemistry on section

Nanci¹,

Wazen²,

Nishio³

et al. 2009

Eur J Histochem

View full text Add to dashboard Cite

The organic matrix of calcified tissues comprises collagenous and/or noncollagenous matrix proteins (NCPs). Identification and precise mapping of these matrix components is essential for determining their function, formulating coherent hypotheses on their mechanism(s) of action, and developing novel therapeutic approaches based on biologics. Fibrillar collagen can be readily identified by its conspicuous structure, however, NCPs, in general, do not individually exhibit characteristic structural features that permit to identify them and morphologically determine their localization. To address this limitation, we have used immunocytochemistry, a form of "biochemistry on section", to correlate composition with structure. For cytochemical characterizations, including immunolabeling, our laboratory has opted for colloidal gold labelings and pioneered their application to calcified tissues because they yield high spatial resolution and are quantitative. Over the years, this approach has been applied to identify and map various NCPs in bone and teeth and, in this review of our work, we will emphasize some selected studies that highlight it application to also achieve functional information.

show abstract

Section: Pathological and Drugs Alterations Of Protein Distributionmentioning

confidence: 66%

Immunocytochemistry of matrix proteins in calcified tissues: functional biochemistry on section

Nanci¹,

Wazen²,

Nishio³

et al. 2009

Eur J Histochem

View full text Add to dashboard Cite

show abstract

“…Protein processing and removal are slowed and the enamel layer is actually flooded by exogenous proteins such as albumin, thereby limiting crystal growth. This situation differs from what happens in bone during chronic hypocalcemia, in which calcium availability may have an important and direct effect on mineral deposition (see Mocetti et al 2000).…”

Section: Discussionmentioning

confidence: 91%

Morphological and Immunocytochemical Analyses on the Effects of Diet-induced Hypocalcemia on Enamel Maturation in the Rat Incisor

Nanci

Mocetti

Sakamoto

et al. 2000

J Histochem Cytochem.

Self Cite

View full text Add to dashboard Cite

S U M M A R YDuring the maturation stage of amelogenesis, the loss of matrix proteins combined with an accentuated but regulated influx of calcium and phosphate ions into the enamel layer results in the "hardest" tissue of the body. The aim of the present investigation was to examine the effects of chronic hypocalcemia on the maturation of enamel. Twenty-one-day old male Wistar rats were given a calcium-free diet and deionized water for 28 days, while control animals received a normal chow. The rats were perfused with aldehyde and the mandibular incisors were processed for histochemical and ultrastructural analyses and for postembedding colloidal gold immunolabeling with antibodies to amelogenin, ameloblastin, and albumin. The maturation stage enamel organ in hypocalcemic rats exhibited areas with an apparent increase in cell number and the presence of cyst-like structures. In both cases the cells expressed signals for ameloblastin and amelogenin. The content of the cysts was periodic acid-Schiff-and periodic acid-silver nitrate-methanamine-positive and immunolabeled for amelogenin, ameloblastin, and albumin. Masses of a similar material were also found at the enamel surface in depressions of the ameloblast layer. In addition, there were accumulations of glycoproteinaceous matrix at the interface between ameloblasts and enamel. In decalcified specimens, the superficial portion of the enamel matrix sometimes exhibited the presence of tubular crystal "ghosts." The basal lamina, normally separating ameloblasts and enamel during the maturation stage, was missing in some areas. Enamel crystals extended within membrane invaginations at the apical surface of ameloblasts in these areas. Immunolabeling for amelogenin, ameloblastin, and albumin over enamel was variable and showed a heterogeneous distribution. In contrast, enamel in control rats exhibited a homogeneous labeling for amelogenin, a concentration of ameloblastin at the surface, and weak reactivity for albumin. These results suggest that diet-induced chronic hypocalcemia interferes with both cellular and extracellular events during enamel maturation.

show abstract

“…Thus, there is now a fairly extensive literature documenting expression and staining of osteoblasts/osteocytes/bone lining cells for TRAP [5][6][7][8][9]. Indeed, osteoblastic cells (MSCs) analyzed in Figure 7 of the current paper clearly express the TRAP mRNA.…”

mentioning

confidence: 74%

Letter re: “The 3.6 kb DNA fragment from the rat Col1a1 gene promoter drives the expression of genes in both osteoblast and osteoclast lineage cells” by Boban et al. (Bone 39:1302–1312, 2006)

Khosla

2007

Bone

View full text Add to dashboard Cite

In the paper by Boban and colleagues [1], the authors used a parabiosis mouse model to test whether osteoblast-lineage cells traversed the circulation of the parabiosed pair. Using mice expressing GFP driven by the col3.6 promoter, they found that there were GFP-positive cells lining bone surfaces in the non-GFP-expressing parabiosed mouse, indicating extensive transfer of GFP-positive cells. In addition, when they infused Lin − Sca-1 + c-kit + cells from a col3.6-GFP mouse into a non-GFP-expressing mouse, these cells also appeared on bone surfaces as GFP-positive lining cells. However, based on immunohistochemistry for TRAP and in vitro bone marrow cultures, the investigators concluded that the GFP-positive cells lining bone surfaces in the two experiments described above were osteoclasts (or osteoclastlineage cells), and that there was no transfer of osteoblast-lineage cells between the parabiotic pairs or differentiation of the Lin − Sca-1 + c-kit + cells into osteoblastic cells.There are some concerns with the interpretation of the findings, and the authors are perhaps overlooking another important cell type, the bone lining cell, which is likely closely related to the osteoblast, but probably serves a very distinct functional role [2]. The alternate explanation for the findings in this paper are that the GFP-positive cells that are lining the bone surfaces in the parabiosis model and in the mice infused with the Lin − Sca-1 + c-kit + cells are, in fact, bone lining cells. These cells lie in close proximity to osteoclasts [2], express bone-related proteins such as alkaline phosphatase, low levels of osteocalcin and type I collagen (i.e., they are not highly active in synthesizing matrix as are the osteoblasts on bone surfaces), and are also positive for expression of intercellular adhesion molecule-1 (ICAM-1) [2,3], which appears to be necessary for binding to osteoclast precursors and the subsequent support of osteoclastogenesis [4]. By contrast, matrix-synthesizing osteoblasts express high levels of type I collagen and are ICAM-1 negative [2]. Moreover, since bone lining cells lie adherent to bone surfaces, they are unlikely to be present in the bone marrow cultures used in the paper to support the argument that osteoblastic cells did not transfer in the parabiotic mice.

show abstract

A Histomorphometric, Structural, and Immunocytochemical Study of the Effects of Diet-induced Hypocalcemia on Bone in Growing Rats

Cited by 25 publications

References 54 publications

Immunocytochemistry of matrix proteins in calcified tissues: functional biochemistry on section

Immunocytochemistry of matrix proteins in calcified tissues: functional biochemistry on section

Morphological and Immunocytochemical Analyses on the Effects of Diet-induced Hypocalcemia on Enamel Maturation in the Rat Incisor

Letter re: “The 3.6 kb DNA fragment from the rat Col1a1 gene promoter drives the expression of genes in both osteoblast and osteoclast lineage cells” by Boban et al. (Bone 39:1302–1312, 2006)

Contact Info

Product

Resources

About