Ch. 2&3 Inflammation and Repair Flashcards
What is inflammation?
The reaction of BVs, leading to accumulation of fluid and leukocytes in extravascular tissues
What are the components of inflammation (WBCs) in order of %?
Neutrophils, Lymphocytes, Monocytes, Eosinophils, Basophils (Never Let Monkeys Eat Bananas)
What is the function of a neutrophil?
First responder, used in ACUTE inflammation. Bacterial or fungal infections. Increased activity and death => PUS
When are lymphocytes more common?
Chronic inflammation
What are lymphocytes?
T cells and B cells
What are monocytes and what is their function?
Long-lived phagocytes, present pathogen parts to T cells
What do monocytes become in tissues?
Macrophages
When are eosinophils used?
Parasite and allergic responses
When are basophils used?
Allergic and antigen responses - release HISTAMINE
What do basophils become in tissues?
Mast cells
What is the life span of an RBC?
120 days
What is the life span of a WBC?
days - years
What is the life span of a platelet?
8 days
What does a lymphocyte become in tissues?
Plasma cell
Onset of acute vs chronic inflammation?
Acute = Rapid onset Chronic = Slower onset
Duration of acute vs chronic inf.?
Acute = short duration Chronic = Longer duration
Which type of inflammation has edema?
Acute
What is the predominant WBC involved in acute inf.?
Neutrophils
Which type of inflammation has new blood vessels, fibrosis, and tissue necrosis?
Chronic inflammation
What are the predominant WBCs involved in chronic inf.?
macrophages and lymphocytes
What is fibrosis?
Space occupying lesion (SOL) on cellular/molecular level
What are the signs/symptoms of acute inflammation?
Redness (rubor), Heat (calor), Swelling (tumor), Pain (dolor), Loss of function (functio laesa)
What are the 3 main vascular changes in acute inflammation?
- Vascular dilation and increased blood flow 2. Extravasation and deposition of plasma fluid and proteins (edema) 3. Leukocyte emigration and accumulation in the site of injury
What is the normal avg. colloid osmotic pressure in a capillary?
25 mmHg
What is the avg. colloidal osmotic pressure in a capillary during acute inflammation?
20 mmHg
Why does colloidal osmotic pressure drop during acute inflammation?
Protein leakage across venule
What is the net result of decresed colloidal osmotic pressure?
Excess of extravasated fluid
What causes oncotic pressure?
Concentration of proteins increases in capillaries, pushing fluid out. Increased concentration of proteins in venules “suck” proteins back in
What controls arteriole pressure?
Precapillary sphincters
What happens when precapillary sphincters relax in acute inflammation?
Hyperemia
What is a Rouleaux?
Stacking of RBCs
What is neutrophil margination?
Pushed to outside of bloodstream due to RBC rouleaux
What is the process of Leukocyte extravasation?
- Margination 2. Pavementing (Rolling -> Tight binding -> Diapedesis) 3. Extravascular migration
What is the relation of Rouleaux to ESR?
Directly correlated - increased rouleaux = increased ESR
What initiates Leukocyte rolling?
P-Selectin and E-Selectin on endothelial cells
What causes Leukocyte binding?
Expression of endothelial adhesion molecules like ICAM-1 (by TNF and IL-1) and increased aviditiy of integrins on Leukocytes (by chemokines)
What causes leukocyte migration after diapedesis?
Chemokines
How are microbes destroyed by macrophages?
- Recognition and attachment 2. Engulfment 3. Microbe ingested in phagosome 4. Fusion of phagosome with lysosome => phagolysosome 5. Killing of microbes by lysosomal enzymes (ROIs and NO)
How are microbicidal reactive Oxygen intermediates produced within phagocytic vesicles?
Cytoplasmic oxidases, membrane oxidases, and myeloperoxidase
What are the 2 groups of mediators of inflammation?
Plasma derived and cell derived
What type of inflammation mediator is histamine?
Cell derived - biogenic amine
What is histamine released from?
Platelets and mast cells
What does histamine induce in endothelial cells?
Retraction - creates gaps => increased permeability
Why does histamine have short action (immediate transient reaction)?
Inactivated by histaminase
What Vitamin stabilizes mast cells?
Vitamin C (acute bolus of ascorbic acid when having a reaction)
What is bradykinin?
Plasma protein derived from kininogen
What enzyme is used to make bradykinin?
Kallikrein
What is kallikrein activated by?
Hageman factor
What does Hageman factor act on besides kallikrein?
Clotting and fibrinolytic systems of blood
What does bradykinin do?
Similar actions to histamine - also induces pain.
What are the preformed chemical mediators in secretory granules?
Histamine, serotonin, lysosomal enzymes
What are the newly synthesized chemical mediators of inf.?
PGs, Leukotrienes, Platelet-activating factors, Activated oxygen species, Nitric oxide, cytokines
What are the chemical mediators that are activated by Hageman factor?
Bradykinin, coagulation/fibrinolysis system
What are the chemical mediators that are activated by complement?
C3a, C3b, C5a, C5b (MAC attack)
What is the complement system?
Group of plasma proteins produced by liver, circulating in inactive form
How is complement activated?
Classical or alternative pathways
What does complement activation lead to?
formation of biologically active fragments, intermediate complexes, and MAC attack complex
What are the 4 main functions of activated complement derivatives?
- Opsonization 2. Anaphylaxis 3. Chemotaxis 4. Cell lysis
What is opsonization?
Flagging of antigens for macrophages to recognize
What is anaphylaxis?
Histamine release with increased vessel wall permeability
What is chemotaxis?
migration of leukocytes
How does complement cause cell lysis?
Through action of MAC - makes cell membranes “leaky”
3 steps of phagocytosis of bacteria?
- Attachment of opsonized bacterium to PMN 2. Engulfment of bacterium 3. Formation of phagocytic vacuole
How is arachidonic acid derived?
From phospholipids through the action of phospholipases
Two pathways which further metabolize arachidonic acid?
Lipoxygenase pway, Cyclooxygenase pway
5 types of arachidonic acid derivatives?
Leukotrienes, Lipoxins, Thromboxane, Prostacyclin, Prostaglandins
What do leukotrienes control?
chemotaxis, vascular permeability, bronchospasms
What do lipoxins control?
vasodilation, inhibition of neutrophil chemotaxis, monocyte adhesion
What does thromboxane control?
platelet aggregation, thrombosis
What does prostacyclin control?
Opposes the effects of thromboxane - antagonist to clot formation
What does prostaglandin control?
smooth muscle contraction
Acute-phase inflammation effects of TNF/IL-1?
Fever, increase sleep, decrease appetite, increase acute-phase proteins, hemodynamic effects, neutrophilia
Long term endothelial effects of TNF/IL-1?
Increased leukocyte adherence, Increased PGI synthesis, increased procoagulant activity, decreased anticoagulant activity, increased IL-1, IL-6, IL-8, PDGF
Fibroblast effects of TNF/IL-1?
Increased proliferation, Increased collagen synthesis (=> FIBROSIS), Increased collagenase, Increased protease, Increased PGE synthesis
Leukocyte effects of TNF/IL-1?
Increased cytokine secretion (IL-1, IL-6)
What is the pathogenesis of fever?
IL-1/TNF change the basal body temp to a higher set point
What is eNOS?
endothelial Nitric Oxide Synthase
What is iNOS?
Inducible Nitric Oxide Synthase
What effect does eNOS have on endothelial cells of BVs?
Local effect - relaxes smooth muscle => vasodilation (increased blood flow => more WBCs)
What does long-term TNF production cause?
Cachexia
When is iNOS activated?
When need to initiate microbial destruction - iNOS makes Nitric Oxide in macrophages
What type of granule is lactoferrin?
Specific granule
What type of granule is lysozyme?
Specific granule
What type of granule is Alkaline phosphatase?
Specific granule
What type of granule is type IV collagenase?
Specific granule
What type of granule is Leukocyte adhesion molecule?
Specific granule
What type of granule is plasminogen activation?
Specific granule
What type of granule is phospolipase A2?
Specific granule OR azurophil granule
What type of granule is myeloperoxidase?
Azurophil granule
What type of granule is lysozyme - bactericidal factors?
Azurophil granule
What type of granule is cationic protein?
Azurophil granule
What type of granule is acid hydrolase?
Azurophil granule
What type of granule is elastase?
Azurophil granule
What type of granule is nonspecific collagenase?
Azurophil granule
What type of granule is BPI?
Azurophil granule
What type of granule is defensin?
Azurophil granule
What type of granule is cathepsin G?
Azurophil granule
Events in resolution of inflammation?
- return to normal vascular permeability 2. drainage of edema and proteins into lymphatics or by pinocytosis into macrophages 3. phagocytosis of apoptotic neutrophils and necrotic debris 4. disposal of macrophages
What cell type has a central role in resolution of inflammation?
Macrophage
What do macrophages produce to initiate process of repair?
Growth factors
What is serous inflammation?
Early stage of most inflammations. Clear, non-viscous fluid
Examples of serous inflammation?
Viral infection of skin vesicles (eg Herpesvirus), joint swelling in RA, eczema, skin burn (blister)
What is effusion?
Fluid secreted from lining of peritoneal, pleural, or pericardial cavities - trapped in compartment
What is fibrinous pericarditis?
deposits of fibrin on pericardium
What is purulent inflammation?
Pus from dead/dying neutrophils
What is an abscess?
Purulent inflammation encapsulated beneath tissue
What is a sinus (in inflammation)?
Purulent inflammation can escape to surface
What is a fistula?
Connection from one place to another
What is a granuloma?
Lymphocytes, epithelioid cells, and multinucleated giant cells
What are epithelioid cells?
Macrophages that resemble epithelial cells - line up around area of inflammation and wall it off
What is granulomatous inflammation characteristic of?
tuberculosis (caseous necrosis)
At what point does a monocyte become a macrophage?
When it leaves bloodstream/enters tissues
When does a macrophage become activated?
In tissues
What cytokine secreted by T cells activates macrophages?
Interferon(IFN)-gamma
Non-immune activators of macrophages?
endotoxin, fibronectin, chemical mediators
What are microglia and where are they located?
Macrophages in the CNS
What are Kupffer cells and where aer they located?
Macrophages in liver
Where are alveolar macrophages located?
Lungs
What are osteoclasts and where are they located?
Macrophages in bone
What are sinus histocytes and where are they located?
Macrophages in spleen and lymph nodes
Products made by macrophages that cause tissue injury/destruction?
Toxic oxygen metabolites, proteases, neutrophil chemotactics, coagulation factors, AA metabolites, Nitric Oxide
Products made by macrophages that cause fibrosis?
Growth factors (PDGF, FGF, TGF-beta), Fibrogenic cytokines, angiogenesis factors, “remodeling” collagenesis
3 characteristic histologic features of chronic lung inflammation?
- collection of chronic inflammatory cells 2. destruction of parenchyma 3. replacement by connective tissue (FIBROSIS)
3 steps of macrophage amplification?
- recruitment 2. division 3. immobilization
Chronic inflammation effects?
SLIDE 67 activated lymphocytes and macrophages influence each other, and release inflammatory mediators that affect other cells
Wound healing vs regeneration?
Healing = wound healing or fibrosis Regeneration = renewing tissues (epidermis, GI epithelium) or compensatory growth (liver/kidney)
What is the cell cycle?
G1 -> S -> G2 -> M -> cell division -> permanent cells OR quiescent cells (G0)
What are quiescent cells?
Stable cells, focus on normal functions instead of generation but are capable of reentering cell cycle. In G0 phase
Can permanent cells (neurons, cardiac myocytes) reenter the cell cycle?
NO
What are the differentiation factors for pluripotent bone marrow stromal cells?
Myo D, myogenin, VEGF, FGF2, Sox9, CBFA1, PPAR-gamma
What does myo D or myogenin cause pluripotent cell to differentiate into?
Myotube
What does VEGF or FGF2 cause pluripotent stromal cells to differentiate into?
endothelial cells
What does Sox9 cause pluripotent stromal cells to differentiate into?
Chondroblasts
What does CBFA1 cause pluripotent stromal cells to differentiate into?
Osteoblasts
What does PPAR-gamma cause pluripotent stromal cells to differentiate into?
Fat cell
What is autocrine signaling?
Target sites on same cell
What is paracrine signaling?
Target sites on adjacent cells
What is endocrine signaling?
Target sites on distant cells - signals enter bloodstream
What is the general signaling pathway used in tissue regeneration?
Ligand binds to target cells, causes cascade of enzymes ->->-> turn on transcription/translation processes for repair
What does binding of growth factor to tyrosine kinase receptors cause?
Receptor dimerization and autophosphorylation of tyrosine residues
How does liver regenerate after partial hepatectomy?
Enlargement of remaining lobe without regrowth of removed lobe
Cytokines that prime quiescent hepatocytes?
TNF, IL-6
Growth factors that act on primed hepatocytes to make them progress through cell cycle?
HGF, TGF-alpha
Adjuvants for liver regeneration?
Norephinephrine, insulin, thyroid hormone, growth hormone
Major components of basement membrane?
Type IV collagen, laminin, proteoglycans
Components of Interstitial Matrix?
Fibrillar collagens, elastin, proteoglycan and hyaluronan
What vitamin is needed for HO-ization in collagen synthesis?
Vitamin C
What reaction needs to happen for collagen to twist properly while being synthesized?
Hydroxylation
What are focal adhesion complexes?
protein aggregates that include vinculin, paxillin, and talin
What do focal adhesion complexes bind to?
ECM components (fibronectin and laminin)
Process of angiogenesis from bone marrow?
endothelial precursor cells (EPCs) mobilized from bone marrow and migrate to site of injury/tumor growth. Once there, EPCs differentiate and form mature network by linking w/ existing vessels
Process of angiogenesis from pre-existing vessels?
endothelial cells become motile and proliferate to form capillary sprouts.
What stimulates matrix metalloproteinases?
PDGF, EGF, TNF/IL-1
What inhibits metalloproteinases?
TGF-beta, steroids
How are metalloproteinases activated?
Plasmin
What do metalloproteinases do?
Break down collagen/debris
What do TIMPs do?
block metalloproteinases with specific tissue inhibitors
What mineral are MMPs dependent on?
Zinc
What are the phases of wound healing?
Inflammation, granulation tissue, wound contraction, remodeling
What are the three intentions of wound healing?
Primary, Secondary, Tertiary
When is wound healing considered primary intention?
wound edges directly next to each other (eg surgical incisions)
When is wound healing considered secondary?
Wider, not clean edges
Does scarring occur with primary intention healing?
Minimal
Does scarring occur with secondary intention healing?
Yes - granulation
What is delayed primary closure?
tertiary intention - wound is purposely left open
What is a keloid?
excess collagen deposition in the skin forming a raised scar
What causes “cauliflower ear”?
Chronic tissue damage to ears
What does persistent stimulus (chronic inflammation) cause?
Activation of macrophages/lymphocytes => Growth factors, cytokines, decreased metalloproteinase activity => increased collagen synthesis/decreased collagen degradation => FIBROSIS diagram slide 98
What is tissue regeneration?
Restitution of normal structure
What is tissue healing?
Scar formation, organization of exudate
What is tissue fibrosis?
Tissue scar