In The Name Of God In The Name Of God EMRI Modeling Group
Cells work together in functionally related groups called tissues Types of tissues: Epithelial lining and covering Connective support Muscle movement Nervous control
Adipose tissue is a loose connective tissue containes: Addipocytes and some collagen and reticular fibers Tissues-lab.ppt 22 Jan. 2013 4
Description Closely packed adipocytes Have nucleus pushed to one side by fat droplet Function Provides reserve food fuel Insulates against heat loss Supports and protects organs Location Under skin Around kidneys Behind eyeballs, within abdomen and in breasts in addition it finds between and around of nerves, muscles. it has own blood supply.
Lipid storage Secretion of different adipokines It plays isolation role in body
Lipid storage Secretion of different adipokines It plays isolation role in body
ontrol of Release of FFA From White Adipose Tissue Lipid storage Diet WAT Starvation Insulin Resistance Lipolysis Insulin Free Fatty Acid Ketone bodies Liver Triglycerides Phospholipids Hypertriglyceridemia Atherosclerosis
Resistin Adiponectin Bone Morphogenic Protein IGF-1 IGFBP Adipose Tissue TNF-α Interleukins TGF β FGF EGF Fatty Acids Lactate Adenosine Prostaglandins Glutamine Unknown Factors Estrogen Ang II Angiotensinogen Leptin PAI-1
Fat consumption is essential: Hormone production Future energy Neurological function Fat soluble vitamins Cell formation Preserving body heat (infants) Shock absorption And much more All calories consumed in excess of what one s body expends will be converted to and stored as fat
Adipocyte fat storage tissue cells Definitions we already know: Once an adipocyte is formed, it can t be removed. Making weight-loss difficult. Hypertrophy increase in volume or size of the adipocyte.(lipogenesis). Result of excess triglycerides Hyperplasia adding more fat storage tissue cells
Hypertrophy (increase in size) Lipogenesis Result of excess triglyceride accumulation in existing adipocytes Hyperplasia (increase in number) adipogenesis results from the recruitment of new adipocytes from precursor cells in adipose tissue and involves proliferation and differentiation Hausman et al. Obesity Reviews (2001) 2, 239-254
Obesity and its prevalence Definitions: Obesity: having a very high amount of body fat in relation to lean body mass, or Body Mass Index (BMI) of 30 or higher Body Mass Index (BMI): a measure of an adult s weight in relation to his or her height, specifically the adult s weight in kilograms divided by the square of his or her height in meters. By the year,2030,2.16 billion people worldwide will be overweight, 1.12 billion will be obese.
Stores excess glucose as glycogen Converts excess glucose into fatty acids
Leptin signals to the brain that the body does not need any more food
Brown Adipose Tissue (BAT): Brown adipose tissue with its special protein named UCP1 ( Termogenin) protects mammals to during periods of nocturnal or hibernoma cold The stress of birth It promoting our survival on diets low in essential micronutrients.
Coactivator protein Ligand PPARγ RXRα Ligand DNA PPRE PPARγ forms a heterodimer with RXR (PPARγ-RXR Complex) to bind to DNA. If ligand binds to either PPAR or RXR, changes in the heterodimer are induced which lead to the release of corepressor molecules and the recruitment of coactivator proteins resulting in the formation of a transcriptional regulatory complex as shown above. This complex then binds to specific PPAR response elements (PPRE) resulting in transcriptional activation of target genes, regulating physiological processes such as adipocyte differentiation, glucose homeostasis, antiinflammation etc.
PPARγ-RXR nuclear receptor complex and transcriptional activity (inhibition) Corepressor protein Mutant PPARγ RXR DNA PPRE Human PPARγ mutants are able to heterodimerise with RXR on DNA but cannot bind ligand. This leads to the recruitment of a corepressor instead of a coactivator protein leading to silencing of target gene transcription.
Low levels of glucose in the blood trigger the mobilization of triglycerides through the action of epinephrine and glucagon. camp pathway activate hormone sensitive lipase to cause hydrolysis of triglycerides into glycerol and FFA
Together, ATGL and HSL are responsible for >95% of TG hydrolysis from WAT
Lipolytic stimulation leads to phosphorylation of HSL and perilipin by PKA Phosphorylation of perilipin causes them to lose their lipolysis-blocking capability Phosphorylation of HSL promotes its translocation from the cytosol to the lipid droplet Required for maximal TG storage in WAT
Hormones include catecholamines, adrenaline, and noradrenaline PKA phosphorylates HSL and perilipin. Receptors are called G-protein coupled receptors called β-adrenergic receptors camp activates PKA When activated, they transmit signals to adenylyl cyclase leading to camp production
Older subjects and those with a higher BMI, have less brown adipose tissue. Suggested that obesity is associated with reduced brown adipose tissue function or activity.
With age adipose tissue primarily shows up in the abdominal region for both men and women. For women, the onset of menopause can lead to the excess abdominal fat due to loss of estrogen.
Pre-menopausal and postmenopausal women have both shown to have a higher amount of intra-abdominal adipose tissue compared to those of younger women.
White circles represent subcutaneous fat, red circles represent visceral fat, and yellow circles represent the appearance of fat in non adipose tissue.
Diabetes: 80% related to obesity Hypertension: prevalence is >40% in obesity Heart disease: 70% related to obesity Cancer: Obesity accounts for 15-20% of cancer-related deaths Death: Obese individuals have a 50-100% increased risk of death from all causes compared to lean individuals (most of this risk is due to cardiovascular disease).
Recent Researchers Dream Will we convert WAT to BAT? If we do it, we will solve many problems, which are related to obesity and its risk factors. Do you agree with us?
Thanks for your In The Name Of God attention