Cell Differentiation I & II Flashcards
What is replacement?
unable to make cells os same type as those lost. CT types “fill in” the space previously occupied by lost cells
Proliferation is controlled by variety of mediators (GF and inhibitors)
What is regeneration?
make new cells of same type as those lost. Depends on ability of cells to proliferate
Proliferation is controlled by variety of mediators (GF and inhibitors)
Regeneration involves what 2 types of tissues?
Renewing tissues (regeneration - skin & GI)
Compensatory growth (liver & kidney)
Replacement involves what 2 responses?
Wound - wound healing, scar formation
Chronic inflammation - fibrosis
What is labile?
constantly cycling the cell cycle
What is stable?
those cells in Go quiescent - hepatocytes
What are permanent cells?
cardiac myocyte & neurons
What is glioblastoma multiforme? What is the specific signaling pathway?
The malignant of astrocytes. Vascular that can be leaky.
Contrast enhancing mass
The malignant astrocytes produce VEGF in response to hypoxia.
What are examples of tyrosine kinase receptors?
EGF, FGF, VEGF, PDGF, TGF-beta. Found in wound healing
What is systemic sclerosis or scleroderma?
disease of chronic inflammation likely due to autoimmunity
involves widespread damage to small blood vessels
injured endothelium releases PDGF & TGF-beta (both are fibrogenic)
Patients develop progressive interstitial & perivascular fibrosis in skin & multiple organs (can have dyspnea)
sclera - hardening
What is the proposed mechanism for systemic sclerosis?
Immune system activation (effector T & other leuks (B)) create cytokines that injure & narrow blood vessels. Blood vessels then secrete PDGF & TGF-beta which entices fibroblasts to grow –> increases ECM –> fibrosis
What type of signaling do you see with systemic scleraderma?
cytokine signaling.
EPO (GF) & JAK (Janus kinase receptor) –> phosphorylates STAT (signal transducer & activator of transcription) –> gene transcription
Can also lead similar to RTK pathway – GRB2–>SoS–> Ras–> Raf —> MAPKK–> MAPK –> TF of gene transcription
What are examples of cytokine receptors?
Erythropoietin, IFN, IL2-IL4…
What is multiple myeloma?
plasma cell neoplasm - bone marrow disease
Patient can be tired - b/c crowding out other cell types
What increases with multiple myeloma? What can it lead to?
Increase IL6 production by osteoclasts
IL- stimulates the growth of multiple myeloma cells
Multiple myeloma increase bone resorption by osteoclasts
High serum levels of IL6 correlate with poor prognosis
Bone destruction can lead to hypercalcemia
What are the 4 ligand classes of G protein linked signaling? What are examples of each? What is their function?
Small biogenic amines - histamine - capillary dilation, smooth muscle contraction; epinephrine - vasopressor
Peptides - substance P - neurotransmitter; bradykinin - vasodilator
Glycoprotein hormones - parathyroid hormone - Ca homeostasis
Phospholipid signaling molecule - platelet activating factor - immune cell regulation
Known inhibitors of growth signaling include ___
Neurofibromin 1 & 2
TGF-beta
WT-1
Interferon-beta
What are features of neurofibromatosis type 1?
autosomal dominant disorder
1/3000
seen in individuals who inherit 1 mutant allele of NF1 gene
Multiple tumors of peripheral nerves (neurofibromas)
Numerous pigmented skin lesions
Pigmented iris hamartomas
The NF-1 gene product turns ___ off
Ras
ECM can contribute to different diseases
slide 36 - integrins communicate to basal membrane