Diabetes Flashcards
Type one initiation?
Up regulation of IFN alpha
Which stimulates cytotoxic Tcells
Up regulation of MHC class 1 enables cytotoxic T cells to attack
TCell attack
Beta cells become available due to apoptosis and the antigens are then displayed to the autoimmune system which creates antibodies
CD8 cytotoxic T cells
Attack the beta cells and bind the cell receptors causing apoptosis as the fasl bind the gas on the B cell
CD4
Present the Antigen receptor on the surface causing the B cell to release cytokines such as TNF alpha which induces apoptosis on other beta cells
Autoimmune diseases
Generally occur when an issue with the Tcell suppression cells, auto reactive cells
Process of increasing autoantibodies
Increased production of IFN before MHC1 increases as well then CD8 binds eating the beta cells before the antigen from the beta cells are transported
Can be extended when CD8 binds and destroys periforin and the process repeats
Time of diagnosis in T1
8years
Type 2
Insulin sensing and signalling
Glucose induced secretion
Glut1 allows glucose into the cell and glucokinase causes its metabolism releasing ATP to close the k channel and sends PDX1 to the nucleus to increase production of insulin and calcium channel opens causing the release of insulin from its capsules
Incretin and glucose induced secretion
GLP1 released when glucose is sensed in the gut and binds the receptor on the B cell increasing camp levels and then PKA and epac2 converge on the exocytosis path increasing insulin secretion
Glucose kinase mutation
Loss of metabolism as glucose cannot be metabolised
Kcnd11 abbc8
Loss of function mutations in the k channel so it cannot be closed
PDX1 mutation
Lethal so no cases present as no insulin at all can be transcribed as its a TF for islet cell or birth
Insulin receptor
TRK docking to IRS1 which activates pi3 kinase which the catalysed the phosphorylation of pip2 converting it to pip3 which activates akt which catalysed phosphorylation of key proteins such as glycogen synthase
Non receptor mutation
The serine is phosphorylated on IRS as opposed to the tyrosine