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67 Cards in this Set
- Front
- Back
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What is the role of mechanical fxn of the ECM?
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strength and support, elasticity and scaffolding for cell crawling
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What is the role of protection fxn of ECM?
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hydrate cells and filter to control movement between undissolved material between cells
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What is the role of organization fxn of ECM?
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integrates cells into tissues, reservoirs for extracellular signaling molecules, influences deve. and differentiation
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What are the 3 major components of the ECM?
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1. polysaccharides
2. structural proteins 3. adhesion proteins |
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What are resistant to compression and sequester growth factors?
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polysaccharides
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What are the 2 main polysaccharides?
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GAGs and proteoglycans
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What are large, give strength, and elasticty to the ECM and consist of collagen and elastin?
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Structural proteins
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What adhere cells to ECM and ECM to ECM and consists of Fibronectin and Laminin?
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Adhesive Proteins
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What are unbranched polymers of repeat disaccharide derivatives?
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GAGs
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What make up GAGs?
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Hyaluronan and other GAGs
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What have compressive strength, attract H20 and cell swells, make up 10% ECM mass and 90% volume?
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Hyaluronan
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What are sulfated, secreted and covalently bound to proteoglycans?
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other GAGs such as chrondoitin, dermatan, heparan, keratan
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What is a serine rich protein decorated with O-linked acidic, sufated GAG's?
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Proteoglycans
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What is the most common proteoglycan and what is it made up of?
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Aggrecan= core protein + 100 chondroitin + 30 keratin chains
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What bind hyalorun via linker proteins?
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Aggrecan-Hyalorun Complex
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Heparan Sulfate is a proteoglycan that can be divided into what 2 families?
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1. Syndecan- transmembrane protein
2. Glypican- covalently attached to membrane |
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What proteoglycan has a role in cell division and growth?
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Glypican
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What proteoglycan serves as a coreceptor for GPCR?
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Syndecan
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What are the 4 main functions of Proteoglycans?
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1. fxns as coreceptor for GF
2. increase GF concentration in ECM 3. localizes GF to specific tissues 4. protects GF from degradation |
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What are two examples of Adhesive proteins?
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Fibronectin
Laminin |
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What is the most abundant protein in animals?
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Collagen
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What is fibrous protein consisting of 3alpha chains and forms a rope-like triple helix?
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Collagen
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What provides tensile strength to ECM?
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Collagen
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What makes up the triple helix of collagen?
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Gly-X-Y
Glycine any (usually proline) hydroxyproline |
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What are fibrils coated with fibrillin microfibrils?
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Elastin
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How is Elastin synthesized?
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by fibroblasts and smooth muscle cells
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What forms a crosslink between fibrils to form a stretchy net?
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Elastin
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What results in a defect in Fibrillin 1 and has symptoms of weak elastic tissue causing long fingers, pigeon chest and weak aorta?
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Marfan's syndrome
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What does lack of vitamin C result in?
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Scurvy. no vitamin c- no formation of proline hydrozylase- no formation of hydroxyproline- so you get weak collagen- weak gums, skin and capillaries
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What is the most common fibrillar collagen?
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Type 1 (90%)- found in bones, skin and tendons
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What type of collagen provides cartilage tensile strength?
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Type II
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What is a fibril assoc. collagen that links Type I and Type II fibrils together?
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Type IX and XII
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What are network forming collagens (meshworks of basal lamina)?
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Type IV and VII
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What adds "stickiness" to ECM?
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Fibronectin
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What is a v-shaped dimer with multiple domains with binding sites for various ECM proteins?
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Fibronectin
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Fibronectin has an Integrin binding site that has what sequence?
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RGD (Arginine, Glycine, Aspartate)
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RGD sequence allows for binding of integrin to fibronectin. what is the main integrin?
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alpha5beta1
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Integrin is bound directly to what in the ECM?
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Laminin
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What is the major component of the basal lamina?
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laminar
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What makes up a weblike structure that is resistant to tensile strength?
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Laminin
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What binds Type IV and attaches to Laminin?
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Perlecan
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What interacts with ECM and thus promotes cell survival?
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integrins
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Integrins promote cell survival by phosphorylation of what?
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FAK and src tyrosine kinase
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What do Integrins require to bind to ligands?
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Ca and Mg ions
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What Integrin binds to Fibronectin?
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alpha5beta1
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What integrin binds to Laminin?
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alpha6beta1
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Integrins associated with Hemidesmosomes and Focal Adhesion Areas. What is each made of?
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Hemi- Intermediate filaments
Focal- Actin filaments |
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What cell adhesion molecule is calcium dependent and binds to cytoplasmic adaptor proteins (catenins)?
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Cadherins
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what is essential for tissue morphogenesis during development?
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Cadherins
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What contributes to contact inhinbition signal when epithelial cells interact?
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Cadherins
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What is expressed on endothelial and recognizes by WBC integrin and move WBC into CT?
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Ig CAM
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What type of selectins are expressed on tissues?
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P and E-selectins
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What are cell-cell adhesion molecules expressed exclusively on cells of vascular system?
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Selectins
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What stimulates selectin expression on cell surface?
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Inflammation
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What are 3 ligands of selectins?
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1. PSG-1
2. GlyCAM-1 3. MadCAM-1 |
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At infection site, macrophages produce what?
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cytokines (TNF and IL 1)
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With inflammation, cytokines activate nearby endothelial cells to produce what?
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1. selectins
2. chemokines |
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What mediate weak tethering and rolling of blood leukocytes on endothelium?
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Selectins
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What has a high affinity for integrins and stimulate migration of cells thru endothelium to site of infection?
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Chemokines
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What are the 3 steps to chemokine and leukocyte adhesion?
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1. Tethering
2. Triggering 3. Adhesion |
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What lymphocyte do you have with NO inflammation?
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Naive lymphocyte homing to lymph node
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What is unique to Naive Lymphocytes?
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L-selectin and CCR7
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What does L-selectin bind to?
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PNAd (peripheral node vascular addressin)
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What does CCR7 bind to?
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either CCL21 or CCL19 (both secreted by HEV)
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CCL21 or CCL19 is activated to express what?
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increase in LFA-1, this will bind to ICAM-1 on HEV
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Cell migration thru ECM requires what?
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proteases
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What can degrade all classes of ECM proteins?
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MMPs (matrix metalloproteinase) thus allow cells to extravacate
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