This extremely technical article explains why and how magnesium is essential to connective tissue, The original article contains far more detail, but left me flummoxed.
The cells which constitute tissue of vertebrates are in charge of the synthesis and remodelling during the life of the four extracellular macromolecules contained in the connective tissue.
- Magnesium stimulates collagen synthesis expressed by fibroblasts in culture.
- Magnesium inhibits prolyl and lysyl hydroxylases and could be considered as antifibrotic.
- Magnesium is associated with elastin and plays a protective role in maintaining the extensibility of elastin.
- Magnesium associated proteoglycans in cartilage prevent the swelling and degradation of this tissue.
- Magnesium regulates the functional activity of integrins.
This non exhaustive list of some properties linked to magnesium makes it a potential leader in physiological and pathological situations which occur at the level of the connective tissue and also at the level of the matrix associated cells.
Magnesium and connective tissue
Magnesium (Mg2+) is the fourth most abundant cation and the second most abundant intracellular cation in vertebrates. The normal adult total Mg2+ content is estimated at 25g (for 70 kg body weight) of which about 53% is found in bone
Magnesium plays an essential role in a wide range of biological processes and is crucial for life. Mg2+ is essential for many enzymatic reactions and develops two interactions
(1) Mg2+ binds to the substrate thereby forming a complex with which the enzyme interacts, for example enzymes that utilize ATP do so with Mg ATP, and
(2) Mg2+ binds to the enzyme and plays an allosteric activator role
Furthermore Mg is critical for some cellular functions such as DNA transcription and protein synthesis
Extracellular matrix is a complex integrated system responsible for the biological and mechanical properties of our tissues. The extracellular matrix is in constant remodelling and tissue homeostasis is a dynamic process involving a balance between protein synthesis and degradation
Cells, which constitute the tissues of vertebrates, are in charge of the synthesis and renewal of the four extracellular macromolecules which compose the connective tissue:
- two fibrillar components, collagens and elastin and
- two other families of macromolecules which do not belong to the fibrillar component, namely proteoglycans and structural glycoproteins.
Collagens and magnesium
The connective tissue exists in a wide variety of specialized forms; the most abundant and ubiquitous element of the extracellular matrix is the collagen family.
Among this family, the classical fibrous collagens (types I, II, III, and V) are found in greatest amounts and type I collagen is quantitatively the most important . The biosynthesis of the collagen molecule is a complex process with intra and extracellular phases.
It has been shown that ascorbic acid stimulates collagen synthesis in dermal fibroblasts by increasing the rate of collagen gene transcription, but unfortunately experiments involving the use of ascorbic acid require daily supplementation of this molecule  due to its instability
Proteoglycans and magnesium
The collagen fibers form a network which appears to be formed by individual fibers interacting with neighboring fibers via other matrix constituents
The cartilage is a highly specialized connective tissue, essentially avascular, the main matrix components are type II collagen and large aggregating proteoglycans (aggrecan), not binding covalently to hyaluronic acid and forming a macromolecular complex with a relative mass exceeding 3 106kDa
Thus we can propose that magnesium maintains the structure and function of the cartilage.
Elastin and magnesium
Elastic recoil is a critical property of several tissues and organs; such as lungs, aorta, and skin... Elastic fibers are found in the extracellular matrix of the connective tissue providing elasticity and resilience to tissue which have the ability to deform repetitively and reversibly.
Elastic fibers are made of two major components: elastin and microfibrils . Deposition of tropoelastin (soluble elastin) into the extracellular space occurs at specific sites on the cell surface, then tropoelastin is incorporated into the forming elastic fiber. Before elastin deposition into the extracellular space, microfibrils are secreted
It has been reported that Mg2+ is associated with the elastin core of elastic fibers and not with the associated microfibrils
Elastin degradation is extensive in many physiological processes such as growth, wound healing, and tissue remodeling
Mg2+ plays a protective role in maintaining the extensibility of elastin
So it appears that Mg 2+ is active in maintaining the structure and mechanical properties of elastic fibers and it is also actively involved in elastic fiber elastolysis.
This non exhaustive list of some properties linked to magnesium make it a potential leader in physiological and pathological situation, which occur at the level of the connective tissue macromolecular components and also at the level of the matrix associated cells.
Magnesium (Mg2+) one of the most abundant cations in vertebrates was shown to be involved in fundamental cellular functions such as adhesion migration and also in protein synthesis
Interestingly Mg2+ is associated with elastin and collagen, two fibrillar components of the extracellular matrix, and also with non fibrillar macromolecules namely proteoglycans and glycoproteins
The cells which constitute the connective tissue are in constant dialogue with the extracellular matrix components.
Due to Mg2+ functions with cells and on extracellular macromolecule structuring, Mg2+ can be considered a pivotal actor in tissue homeostasis.