Research concentrated on both the physiological causes and the consequences of prolonged adiposity has recently expanded as a result of the rising prevalence of obesity and related diseases. New studies show that understanding the mechanisms of specific immune cells in adipose tissue, the tissue responsible for storing excess fat, may be the key to understanding and treating the modern obesity epidemic. Group 2 innate lymphoid cells (ILC2s) and their secreted type 2 cytokines have been strongly linked to the metabolic regulation of adipose tissue and promotion of thermogenesis, however the specific mechanisms of this pathway are unknown. The research presented here outlines the examination of how ILC2s and related immune cells are …show more content…
Adipose tissue is the specialized connective tissue which stores energy as fat, as well as being responsible for generating heat within the body (9). The two types of adipose tissue, white adipose tissue (WAT) and brown adipose tissue (BAT), have distinct roles in fat storage and obesity. BAT is a major source of thermogenesis, and its development has been implicated in suppressing diet induced obesity (9). The brown adipocytes which make-up BAT contain many mitochondria and express high levels of uncoupling protein-1 (UCP1), a protein which generates heat through uncoupling of the respiratory chain and substrate oxidation (11). WAT performs the anabolic role of storing energy, and has been linked to diseases such as type 2 diabetes in states of prolonged obesity (1,9). More recently however, an additional subcategory of adipocytes has been discovered, known as beige or brite (brown in white) adipocytes. These cells are similar to brown adipocytes as they express high levels of UCP1 and stimulate thermogenesis, however their presence in WAT can induce lipolysis of WAT stored fat (7,17). This WAT browning pathway is an area of active research, as the energy expenditure presents a potential strategy for treating obesity. The differentiation of brite adipocytes is unknown however, as
Towards the end of his medical training in the early 1980s, Gokhan Hotamisligil was working on a unique tumor case on a patient and found they were comprised primarily of fat cells. The fatty tumors were due to a rare condition, Proteus Syndrome. Working in the field of metabolic regulation Hotamisligil began to explore the underlying pathways for insulin resistance. In his dissertation he discovered that the fat tissue of obese animals and humans were capable of producing inflammatory mediators. His research helped shape the current view of fat tissue as a “discrete, active organ in its own right, continuously exchanging messages with the rest of the body by way of the bloodstream.” By early 2002 Hotamisligil and his laboratory made
Genetic research of obesity was partly successful in establishing obesity in model organisms – rodents where obesity occurs spontaneously together with other pathological aspects (insulin resistance, …). The main cause of monogenic obesity in these model organisms are common mutations always present in only one gene. Results of research on model organisms allowed us to understand biological mechanisms of calorie intake and regulation and maintenance of body weight. The most important insight into obesity was achieved in 1994 after discovery of ob gene encoding for leptin. In two years period, using screening method, candidate homologous genes, selected on genetic study basis on mice, another five genes were identified. Mutations on these genes were found to be the cause of autosomal recessive or dominant monogenic obesity. Products of these genes are leptin and its receptor, proopiomelanocortin (POMC) melanocortin receptor 4 (MC4R) and
The pathophysiology of obesity is when there is a buildup of excess body fat. This excess body fat is determined by calculating a person body mass index (BMI). The BMI is calculated by an individual’s weight in kilograms divided by the square of a person’s height in metersthis allows us to come up with appropriate range of weight to an individual’s height. The body mass index is used to find out if an individual is overweight or obese. Individuals who’s BMI that have a range of 25 to 29.99 are thought to be pre- obese and overweight When an individual body mass index has surpassed 30kg this person is considered obese. As an individual’sBMI increases they become part of a different class of obesity there’s class I which is 30-34.9, class II
The dangers of the obesity epidemic are overwhelming and the percentage of the population which suffers from this condition is increasing exponentially with the increased use of HFCS. Especially in the United States, where almost a third of the adult population is obese, the problems with obesity are readily becoming more apparent. Researchers predict that about 30 serious medical conditions can arise due to obesity. Some of these complications are type II diabetes, high blood pressure, coronary heart disease, and arthritis. Problems can also extend to hypertension, birth defects, increased chances of various cancers, and impaired mobility.
Although the mechanism of obesity development is not fully understood, it is confirmed that obesity occurs when energy intake exceeds energy expenditure. There are multiple etiologies for this imbalance, hence, and the rising prevalence of obesity cannot be addressed by a single etiology (Dehghan et al., 2005, p.
On a molecular level, fat tissue is normally the largest organ in humans and is involved in mechanisms and pathways that deal with longevity. Fat tissue is not only involved in energy storage but is also important in immune and endocrine function, thermoregulation, mechanical protection, and tissue regeneration (Tchkonia et al., 2010). Adipose tissue is able to protect against infection and trauma. It is also able to produce and activate hormones, including IL-6, IGF-1, and glucocorticoids, as well as prevent heat loss (Tchkonia et al., 2010). Throughout life, changes in fat distribution and function is constantly occurring and in older individuals, these changes correspond to a number of health disorders like hypertension, cancers, cognitive dysfunction, and diseases like diabetes, heart attacks, and strokes, as previously noted (Tchkonia et al., 2010). As people age, their body composition increases in fat mass and decreases in muscle mass, regardless of their body weight or BMI (Dorner and Rieder, 2011).
Obesity is described by the World Health Organisation (WHO) as unusual or extreme fat growth that presents a risk to a person’s health. Obesity is a complex disease with multiple drivers such as
“ 1. Adipokines are hormones produced by adipose tissue. /…/ Adipokines have effects not only on tissues but [also] on the hypothalamic and pancreatic function. /…/ 2. Elevated serum free fatty acids and high intracellular deposits of triglycerides and cholesterol. These lead to metabolic overload with interfere of insulin signaling and a decrease in tissue response to insulin. 3. Obesity causes release of inflammatory cytokines. /…/ These play an important role in the genesis of a fatty liver [which impairs the function]. 4.
Although many individuals are uncertain about the increasing statistics associated with obesity, more than seventy percent of men and virtually sixty-two percent of women within the United States adult population are overweight or obese (Wilmore, Costill, & Kenney). Obesity refers to the condition of having an excessive amount of body fat. If an individual’s amount of body fat becomes too excessive, he/she is at a much greater risk of developing life-altering diseases such as heart failure, hypertension, type II diabetes, cancer, gallbladder disease, osteoarthritis, etc. (Wilmore, et al., 2008).
Obesity is defined as the excessive build-up of body fat that has major detrimental effects on an individual’s health (Caballero, 2007). The major cause of this excess accumulation of body fat is due to a positive energy balance i.e. when the input of energy into the body system exceeds the output of energy which in turn facilitates in weight gain (Caballero, 2007). Obesity is a major health issue in modern day society, firstly because it affects approximately 300 million people worldwide (Weight Management Centre and secondly, drastic alteration in the body’s fat intake also leads to the increasing prevalence of other major health conditions such as cardiovascular disease, stroke, non-insulin dependent diabetes and hypertension (WMC, 2010).
Over the past twenty five years, obesity ratio has been rising dramatically. And it is continued to become a problem in the United States. Obesity is a serious problem which should be concerned and solved by our society. The negative effects it has on individual are much larger than we think. Gaining extra weight, heart disease, and serious problems can change our human life forever. Furthermore, obesity also affects the society by costing tax payers and the government money to treat these issues. There are currently many ways of how to fight and stop the problem while it is increasing. One of the ways to help us combat with the obesity is to look at the causes such as: lack of energy balance, physical activity, and heredity.
Obesity is increasing throughout the world and is a combination of poor food choices and physical inactivity. It is the second leading cause of preventable deaths in the United States and is responsible for nearly 300,000 deaths per year. An obese human body consists of it carrying an excess amount of adipose tissue. Adipose tissue is an endocrine organ that secretes many products such as metabolites, cytokines, lipids, and coagulation factors. The human body needs some body fat for insulation, storing energy, and shock absorption, however obesity causes increased levels of circulating fatty acids and inflammation. Being obese can cause numerous problematic disease such as diabetes, heart disease, and high blood pressure. According to a research article by Eric Ravussin, PhD., “Obesity is a disease that affects more than one-third of the U.S. adult population (approximately 78.6 million Americans). The number of Americans with obesity has steadily increased since 1960, a trend that has slowed in recent years but shows no sign of reversing. Today, 69 percent of U.S. adults are categorized as being affected by obesity or having excess weight.” (Obesity Society) Obesity continues to significantly impact our health-care costs in the United States. The cost of health-care for obese adults is close to two-hundred billion dollars a year.
Obesity is known to produce a number of stress and inflammation responses in the body that lead to the activation of the inflammatory signalling molecules, Jun NH2-terminal kinase (JNK) and inhibitory kB kinase (IKK). Activation of these pathways plays a key part in the development of insulin resistance followed by progression to diabetes as they greatly affect inflammatory responses, insulin signalling, and lipid and glucose homeostatis (Nakamura et al. 2014). For example, activating the JNK pathway leads to serine phosphorylation of insulin receptor substrate (IRS) proteins which results in inhibited insulin signalling and thus insulin resistance. Double-stranded RNA-dependent protein kinase (PKR) has recently been shown to control the JNK and other major inflammatory pathways, to directly inhibit insulin signalling, to be activated by fatty acids as well as endoplasmic reticulum (ER) stress, and to be necessary for the activity of inflammasomes (Nakamura et al. 2010; Komiya et al. 2010; Lu et al. 2012). Moreover, PKR has been found to be highly activated in obese people as well as mice with genetically and diet-induced obesity, especially in adipose and hepatic tissues (Boden et al. 2008; Nakamura et al. 2010; Carvalho-Filho et al. 2012). Finally, recent studies have found that PKR knockout obese mice were protected against both IR and obesity-triggered inflammation and that administration of PKR inhibitors reduced JNK activation, reduced inflammation in adipose
Cardiovascular diseases are the number one factor that can erupt from obesity due to the main causes that it brings, like high blood pressure, and LDL cholesterol to a high count while lowering HDL. LDL is the “bad cholesterol”, and HDL is the “good cholesterol”. We need fats in our body for energy or ATP, in our body. If we get more LDL, it can really be a dangerous case, and
The epidemic of obesity is a medical circumstance defined as excess weight in the form of fat which may impair health. (World Obesity Federation, 2012). Obesity can be calculated by BMI which is body mass index. Obesity means BMI greater than 30. (ibid). This essay will outline the causes and effects of obesity. Diet, lifestyle, toxic environment and the causes of obesity are physical, psychological and economic are impacts.