Osteopontin or OPN is a protein in human body, encoded by the SPP1 gene. It is an extracellular matrix protein and an organic component of the bone. As the name itself suggests, this protein is expressed primarily in bone (the term prefix “osteo” indicates that). But it is present in other tissues as well. The suffix “pon” stands equivalent to bridge in Latin and therefore, asserts its role as a protein linker.
This matricellular protein mediates diverse biological functions. It is used in the pathogenesis of a variety of diseases like glomerulonephritis, cancer, atherosclerosis and other inflammatory diseases. It possesses a negative charge because of acidic amino acids and serine phosphorylation.
Now, coming to OPN’s role in health issues. Since its first description almost two decades ago, Osteopontin has been an active component in physiological and pathological studies. Areas of its implication include tissue remodeling, inflammation, and biomineralization. OPN in inflammation causes IL-17 production and is hence, seen in a variety of inflammatory diseases like IBD. The level of its secretion increases in bone and kidney during wound healing and inflammation processes. It is induced in macrophages by several inflammatory cytokines.
Chronic inflammation is characterized by the persistence of macrophages at sites of injury and disease. Therefore, in scientific researches when OPN-null animals were put into chronic inflammatory conditions, a deficit in macrophage was found.
OPN in obesity and diabetes is another major risk factor for osteopontin, is the development of resistance towards insulin that leads to Type 2 Diabetes and subsequent complications such as obesity. Several medical researchers have asserted OPN as a critical regulator of adipose tissue inflammation and insulin resistance. This can cause disrupted functionality of body systems. It, in turn, can be harmful and can also make the patient prone to weaker immunity system.
Osteopontin in biomineralization continuous high negative path with OPS which leads to its identification as a poly-aspartic-acid motif (ployAsp) and acidic serine and aspirate rich motif (ASARM). The fact that it is a negatively charged and has a highly disordered structure allows it a stong bond of available calcium atoms at surfaces of different biominerals. If it continues to happen for a long time, it can easily be a major cause of problem in the bodily functions causing pain. Surprisingly, it is mostly women who suffer from this condition and every one after the age of 30 years should visit doctors regularly to check their OPN level.
Therefore, the following kinds of binding of osteopontin to various types of calcium based biominerals inhibits mineralization like calcium phosphate minerals in teeth and bone which makes the enamel and bone swell up causing pain and inflammation. Next is calcium carbonate mineral deposition in the inner part of ear and calcium oxalate mineral in a kidney stone. This excess deposition will cause unnecessary pain and trouble in the body. This calls for immediate action and help.
The best way to avoid all these medical conditions and keep the bones stronger and healthier is to maintain a healthy lifestyle. If one can maintain osteopontin level in body, there is a better chance that their body will not be able to fight age properly.