A contribution with review to the description of mineralization of bone and other calcified tissues in vivo

Abstract

This manuscript considers certain aspects of mineral deposition in bone and other vertebrate calcifying tissues in order to examine physical, chemical, and biological factors important in the mineralization process. The paper in a discussion format principally presents a new data and the formulation of concepts based on such data as well as a summary of background material as necessary review. Mineralization is found to occur at spatially independent sites throughout the organic extracellular tissue matrices. Matrix vesicles and collagen fibrils each may serve as independent nucleation centers for mineral with vesicle mineralization being local and collagen mineralization dominating the tissues as a whole. Collagen fibril organization is suggested to be such that hole zones are aligned in three dimensions, creating extensive channels for mineral accommodation. Nucleation occurs initially in hole zones and crystal growth leads to the development of plate-like mineral particles whose orientation, disposition, and sizes within fibrils are detailed. Effects of diffusion, crystallinity, and critical nucleation and growth events are described with respect to their influence on mineral deposition in bulk and local regions of tissue matrices.

Mineralized Blood Vessels in the Capsules of Human Pineal Glands

“…In our previous study 2 , the pineal gland capsular concretions showed variable amounts of fibrous globular structures that could represent the calcification of cell remnants or matrix vesicles [11][12][13][14] . In this scenario, some of the cell remnants might become the minute spherical deposits MSD showing hyper mineralization 2 observed herein.…”

“…However, the three-dimensional BSE images of blood vessels taken in this study showed the position of the mineralized deposits generally consistent with the circular arrangement of smooth muscle cells in the media walls. In addition, the smooth muscle cells of aortic 14 or arterial walls 15 are calcified in several diseases as well as the collagen fibers of connective tissues 11,[16][17][18] and the collagen and elastic fibers of aortic or arterial walls 18 .…”

“…These pineal glands also contained mineralized blood vessels as seen in Fahr s disease 15 , and many capsular concretions. Therefore, in a human pineal gland susceptible to mineralization, a process is most likely to occur in the connective tissue capsule [12][13][14][15][16] of the gland as well as in the matrix 11,12,14 .…”

A Locus on Chromosome 7 Determines Dramatic Up-Regulation of Osteopontin in Dystrophic Cardiac Calcification in Mice

“…Physiological and certain forms of pathological calcification may share common elements (eg, the formation of matrix vesicles) depending on the type of tissue and the etiology of tissue injury. [41][42][43] The aim of the present study was to explore a putative role of Opn for the development of one type of pathological calcification, DCC, that occurs in the myocardium of genetically predisposed inbred strains. We used a model of severe myocardial freeze-thaw injury to produce reliably necrotic calcifications within a few days.…”

Biology of bone and how it orchestrates the form and function of the skeleton

“…At a point of supersaturation, mineral crystalization begins and as the matrix vesicles disintegrate, the mineral is exposed to the matrix where the process of mineralization proceeds in a self-perpetuating manner. During this process, collagen fibrils, fibronectin, and glycoproteins such as osteonectin and osteopontin determine the orientation and organization of the bone mineral crystal [11]. Other glycoproteins such as matrix-gla protein and glycosaminoglycans appear to play a role in the inhibition of excessive mineralization [50].…”