adipose cells kibbe sandin 11/21/05
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ADIPOSE CELLS
Kibbe Sandin
11/21/05
Overview:
-Types of tissue
- Storage of Fat
- Components of Adipose tissue and how they bond
- Location
- Purpose
-Types
-Relation to cancer
-Relation to Insulin
• There are four main tissue types– epithelial tissue
– connective tissue
– nervous tissue
– muscle tissue
Adipose tissue is another loose form of connective tissue
- stores fat in adipose cells that is distributed throughout the matrix.
How does this store fat? …..
• Adipose cells store fat
• Swell when fat is stored and shrink when the fat is used as fuel.
• Key in storing fuel molecules and insulating and padding the body
• fat stored in these cells –– fats eaten – manufactured within the body from fats,
carbohydrates and protein in the food
• Key components of adipose cells
• neutral glycerol esters – part of a group of Carboxylic acids
• Stearic acid CH3(CH2)16COOH
• Oleic acid CH3(CH2)7CH=CH(CH2)7COOH
• Palmitic acids CH3(CH2)14COOH
• Bonding of carboxylic acids
• Carboxylic acids are the most acidic class of compounds that contain only carbon, hydrogen, and oxygen
• Hydrophilic
• Lipophilic
• Amphiphilic
• Found?• Mainly beneath the skin - panniculus adiposus
• deposits between the muscles
• among the intestines and in their mesentery
• around the heart
• Purpose – Uses…
• fuel reserve
• Conservation of heat of the body
• forms soft and elastic pads between the various organs.
• Types
• White – single large lipid
vacuole directly
below skin
• Brown – multiple lipid vacuole • interscapular region and the axillae
• When adipocytes (adipose cells) fill with lipid and get to a critical size, it results in an increase in their numbers
• This critical size does not occur with moderate overfeeding, but rather long term
• Once new adipocytes are formed, they remain throughout life and only a reduction in size of the cell is possible
• This increased number of adipocytes has consequences for the treatment and prevention of obesity
• Lipogenesis is the deposition of fat.
• Lipolysis is the chemical decomposition and release of fat from adipose tissue.
• Adipose cells related to cancer?
• Relationship between adipocytokines (adipose tissue hormone) and cell regulation - Leptin : main effect is regulation of homeostasis
Glucose and lipid metabolism, angiogenesis, blood pressure reglation, bone formation
- Adioponecctin: protein exclusive in white adipose cells
anti-atherogenic, anti-inflammatory, insulin-sensitizing
- Well documented that obesity increases risk of prostate, breast and colon cancer
- Leptin – shown to stimulate growth migration and invasion of cancer cells in vitro,promoting malignant biological behavior
• Insulin and Adipose cells?
• Insulin well known to play a key
role in adipose differentiation
• Insulin signals for Lipogenesis and Adipogenesis– Insulin is a major hormone controlling energy function
due to insulin binding to receptors
• Large lipid droplets observed
• Glycerol released form cells increased
• Glucose uptake increased
Mouse study:–Stromal cell line used – differentiation by
treating cells with alpha –MEM
(a mimal essential medium for in vitro experimentation)
–Preadipocyte cell line – cultured in DMEM and Dex ( dexamethasone)
–Differentiation initiated by addition
of insulin
The Stromal line was found to be able to convert to mature adipose cells and accumulate tryglicerides and glycerol
Showing stimulation between intracellular signaling = easy reaction and binding = easy growth and multiplication
• References• Adipose Tissue, Encyclopedia Britannica, 2005
• Ann L. Albright, Judith S. Stern, Adipose Tissue, Encyclopedia of Sports Medicine and Science, May 1998
• Christopher F. Lurat, Klaus Natter, Julia Petshnig, Heino Wolinski, Kim Scheuringer, Harald Scholz,
Robert Zimmerman, Regina Leber, Rudolf Zechner, Sepp D. Kohlein, Obese yeast: Triglycerides Lipolysis is Funtionally conserved from Mammals to Yeast, JBC Papers in Press. Nov. 2, 2005
• D. Housa, J. Housova, Z. Vernerova, M. Haluzik, Adipocytes and Cancer, Psychological Research Pre-Press Article, 1-22
• Leonard Napolitano Ph.D., The Differentiation of White Adipose Cells: An Electron Microscope
Study, The Journal of Cell Biology, Vol. 18, 663-679, 1963 • Satoshi Morito, Kuniko Yaguchi, Mikki Imada, Chihiro Tachikawa, Masaaki Nomuro, Shuzo
Moritani, Manabu Igarashi, Kiochi Yokogawa, Ken-ichi Miyamoto, Insulin Signaling in Adipocytes Differentiated form Mouse Stromal MC3T3-G2/PA6 Cells, Biology Pharmacy Bullitin, Vol. 28, No. 11, 2040-2045, July 2005
• Varastehpour Ali, Radaelli Tatjana, Minium Judi, Ortega Henar, Herrera Emilio, Castalano Patrick, Hauguel-de Mouzon Sylvie, Activation of Phospholipase A2 is associated with Generation of Placental Lipid Signals and Fetal Obesity, Journal of Clinical Endocrinology & Metabolism. October 25, 2005
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