The Erk Mapk Pathway Causes Osteoporosis And Formation During Bone Remodeling

An imbalance in the regulation of bone remodeling's two contrasting events, bone resorption and bone formation, results in many of the metabolic bone diseases, such as OSTEOPOROSIS.

As generally stated in the introduction, osteoporosis is a skeletal disorder that involves the strength and integrity of one’s bones. The WHO defines osteoporosis as, “a systemic skeletal disorder characterized by low-bone mass, deterioration of bone tissue, increased bone fragility, and its susceptibly to recurrent fractures.” 2 The most important factor to take into account when addressing osteoporosis is the mass of bone, also referred to as, bone mineral density (BMD). As bone mass begins to decline, typically in the older population, specifically postmenopausal women, individuals are at an increased risk for fractures.3 As a result of this serious condition, many people are affected by morbidity, mortality, and economic difficulty.1

Osteoporosis develops when the remodeling cycle, which is when the disruption of the bone resorption and bone formation occurs. The imbalance of the remodeling cycle causes osteoporosis. Hormones, cytokines, and paracrine stromal-cell interactions affect the osteoclast’s processes, which includes proliferation, maturation, fusion and activation. The osteoclasts are controlled by the interaction between several interleukins, tumor necrosis factor, transforming growth factor-beta, prostaglandin E2 and hormones. The glucocorticoid-induced osteoporosis is related to increased destruction of osteocytes. Glucocorticoid increase receptor activator of nuclear factor ligand (RANKL) effect and inhibit osteoprotegerin (OPG) production through

same amount of bone being replaced is equivalent to the same amount of bone that is

Osteoporosis is commonly known around the world as the numbers continue to increase every year. Osteoporosis is known to cause problems in middle aged women and occasionally effecting some men (1), currently reaching the number of 200million women diagnosed with osteoporosis (2). Arthritis Organisation states that anyone can get osteoporosis but women are about four times more likely than men to develop it, with two main reasons contributing to this fact. For several years after menopause occurs (ovaries stop producing oestrogen), the process of bone loss speeds up, increasing the chance of being diagnosed with osteoporosis. Yet men generally reach a higher level of bone density before the process of bone loss begins. Although

Fragility fracture is occasionally the first presentation of osteoporosis. The incidence of osteoporosis-related fractures has been reported to increase with age and over 50% of the incidents occurring in menopausal women aged > 75 years. Vertebral column and hip are the most common site of fracture contributing to a significant morbidity and mortality in the elderly. Additionally, patients with a history of a fracture have a higher chance of encountering future fractures (Anders et al. 2007).

Osteoporosis is when bones become weak or brittle, and have reduced mass. The bones in the human body are constantly renewing themselves, meaning, the old bone is replaced by new bone and then broken down. At a young age, the body makes new bone at a faster rate than it tears down old bone resulting in an increase of bone mass. However, at a older age, the body stops producing new bone and has to rely on the bone mass that was built up at a younger age.

Osteoporosis is referred to as the decrease in bone density and mass over time. The interior bones become progressively weaker and can cause a stooped posture. This makes the individual more susceptible to bone fractures. Osteopenia regards a condition where the bone material density is considered lower than normal. This is usually a precursor to the musculoskeletal disorder, known as osteoporosis. The term ‘osteoporosis’ means ‘porous bones’. In this case, bone is a living tissue that is continuously being broken down and replaced. Thus, osteoporosis happens when the creation of bone does not keep up with the removal of the old bone. In this disorder, the bones are diminished and deteriorated in structure. This condition is typically prevalent in older women due to an estrogen deficiency with menopause. The lack of estrogen increases bone resorption and decreases bone deposition. In addition, osteoporosis can occur with atrophy, which is caused by disuse. Additionally, osteoporosis can occur in men due to the aging process as well as patients who have received corticosteroids, which are hormones used to treat inflammatory conditions.

Those who are genetically predisposed, intake a diet that is low in nutrients especially calcium and vitamin D, live a solitary lifestyle or drink or smoke regularly are at higher risk of contracting this disease. However, one of the greatest contributors of all is hormones. Hormones, in particular oestrogen are linked heavily to bone growth (Dr. Alice Robert,2002). Oestrogen controls the rate in which your Osteoblast and Osteoclast cells do their job. Osteoblast cells repair and create new bone while your Osteoclast cells break down old bone .A drop in oestrogen results in a

Osteoporosis is an imbalance between bone loss and bone remodeling. Basically the bone density has become extremely low causing much pain and a higher chance of fractures and or bone breakages. Bone remodeling is responsible for removing mature bone tissue and replacing it with new bone tissue. This disease is more common in older adults, Asians, and Hispanics due to the lack of calcium consumption. Women are often more prone to getting osteoporosis than men because women are born with less bone mass than men. This disease often occurs if full bone mass was not achieved during the bone-building years.

Currently in my family my mother and my grandmother both have osteoporosis. “Osteoporosis is a condition characterized by a decrease in the density of bone, decreasing its strength and resulting in fragile bones” ("Osteoporosis", 2012). Osteoporosis can cause bones to break very easily. All it takes is the slightest accident and you can end up with a fracture or a complete break. The spine, hips, ribs and wrists are the most common bones broken because of this disorder. All of these most often are a result in a fall, but can happen at any point during a slight trauma. Currently there is about 55% of the population over the age of 50 that have osteoporosis or osteopenia. ("Osteoporosis", 2012) “One in two Caucasian women will

According to the National Osteoporosis Foundation, “About 54 million Americans have osteoporosis and low bone mass, placing them at increased risk for osteoporosis. Studies suggest that approximately one in two women and up to one in four men age 50 and older will break a bone due to osteoporosis.” The bone disorder may be common, but there are many risk factors for osteoporosis. Osteoporosis usually happens with elders, especially in postmenopausal women. According to Human Anatomy and

Agnes Heinz, Ph. D. former director of Nutrition and Biochemistry with the A.C.S.H. made great points about osteoporosis in her article. Osteoporosis is a bone disease where bones begin to weaken and get brittle. Bones store calcium to make bones stronger. As we gradually get older the harder it is to absorb calcium is why children should get as much calcium as they can. Once our bones stop developing we can’t absorb calcium as well and over time we will become weaker, which could lead to the development of osteoporosis from having weak bones. Osteoporosis usually affects the vertebrae, hip, or wrist. The older we get the more bone loss progresses making it harder to perform typical daily activities. The bone loss makes us more vulnerable to fractures. The smallest fall or thing you pick up the higher chance you have of fracturing a bone if you have osteoporosis. The disease affects people in many ways than one. Besides it being painful it also slows people down on what they can and can’t do. This disease is a very complex one that has a couple types, risk factors, ways of identifying the disease, and ways to avoid getting osteoporosis.

Osteoporosis is the weakening of bones, hence making bones more fragile. Just like any other illness out there, osteoporosis can be treated better the earlier it is detected. Since the bones are weak, one prognosis of this bone disease will be many types of fractures. According to emedicine, osteoporosis is responsible for 1.5 million fractures every year. It is safe to say that patients will be likely to suffer from a bone fracture at least once in their lives. Elders are more prone to suffer from hip fractures, which is the most dangerous fracture an osteoporosis patient can receive. However, once patients find out that they have this disease, they will be more cautious of their surroundings and will become less likely to have a fracture.

Estrogen plays many functions in our body. One of its primary functions is associated with skeletal growth and bone homeostasis, including the inhibition of bone reabsorption. In women affected by estrogen deficiency, the decrease levels trigger an increased production of cell mediators such as cytokines (interleukin-1, interleukin-6, and TNF) leading to the stimulation and proliferation of osteoclast precursors. Decreased level of estrogen also contributes to osteoclast differentiation via RANK pathways. Therefore, even in the presence of osteoblastic activity as a compensatory mechanism, to produce new bone formation, this activity cannot keep up with the higher rate of bone loss, leading to early osteoporotic