C Edmead Lec 3 & 4 Therapy Rationale Flashcards
Steroids are specific anti-______ agents unlike the DMARDs
Anti-inflammatory
Steroids decrease ______. Decrease the flow of WBC’s from blood vessels into tissue therefore less activation that can drive inflammatory response.
Extravasation
Steroids dampen down activation of cells in tissue e.g macrophages and decrease secretion of cytokines from _ cells.
Therefore fewer inflammatory cytokines produced.
T-cells
Steroids work at the gene level by altering ____ ______.
DNA encode genes - transcribed to proteins - function in the cell.
Want to decrease expression of inflammatory proteins and increase expression of anti-inflammatory proteins.
Glucocorticoids are lipophilic so diffuse across cell membrane and enters cell and binds receptors inside cell (intracellular). This steroid bound to the receptor (transcription factor) then translocates to _____ and effects which genes switched on and off by inhibit binding of other transcription factors (__-_ and ____).
- Try and target proteins that target pro-inflam gene transcriptions.
Gene transcription
Nucleus
AP-1 and NFKB
Idea is that glucocorticoids prevent transcription of __-_ and ___ and other inflammatory mediators and increase gene transcription of __-__ and __-_ that are anti-inflammatory cytokines.
IL-1 and TNF
IL-10 and IL-4
Side effects due to inability to get steroids that do not interfere with other effects of steroids e.g ________ (thinning of the bone)
Osteoporosis
Steroids decrease ____ synthesis. Which can be a good thing as we know the antigen is in collagen and new collagen can activate the immune synthesis even more! BUT we need to keep the joints working so need some of it!
Collagen
Osteoblasts lose function due to ______ use. And this use can also cause a reduction in _____ absorption which is needed to make strong bones.
Steroid
Calcium
Use of steroids can also increase ____ and also induce type 2 ____. This increases risk of obesity which can lead to stress on joints.
Appetite
Diabetes
Mineralocorticoid effects when using steroids can lead to __/__ retention. This can lead to hypertension, oedema and CV events.
Sodium/water retention
If too high a dose of steroids will block inflammation and WBCs (_____) can’t enter tissue. This can leave patient open to other opportunistic infections.
Leukocytes
TNF - Tumour Necrosis Factor
Is a ___-______ cytokine that can also cause _____
IL-1 is also a __-_____ cytokine that can stimulate NFKb transcription factor which switches on pro-inflammatory genes along with TNF.
TNF and IL-1 binding to receptors up regulates theirselves and each other,
Pro-inflammatory cytokine
Apoptosis
TNF and IL-1 activate the ____ immune system. This activates macrophages etc. This can then lead on through cytokines and presentation of antigens to activate the ____ ______
Innate immune system
Adaptive immune system
TNF and IL-1 are both produced by _ _ _ or endotoxic activated monocytes (in blood) become macrophages when enter tissue.
LPS
IL-1 is found in 2 forms.
Target IL-1 _ form as alpha is not involved.
BETA
Most proteins made in the __ whereas IL-1 synthesised in ________.
IL-1 synthesised as precursor and cleaved by IL-1 Converting Enzyme (ICE) - this is known as _____-1
Endoplasmic reticulum.
Microtubules.
Caspase-1
Targeting ICE inhibitors would be a good ___ ______ _____ but this has not been shown to be effective!
Release of enzyme facilitated by P2X7 receptor so interest in developing P2X7 ______ as an anti-inflammatory agent.
Anti inflammatory agent
Antagonist
- IL-1 initially localised effect but then circulates bloodstream ( _____ effect) and can cause fever (heat and swelling in joints).
Systemic
IL-1 production leads to increased synthesis of COX-2 (leads to _____ formation) and INOS (leads to ___ _____). These enzymes are only upregulated in inflammation.
Prostaglandins Nitric oxid (Inducable nitric oxide synthetase)
- IL-1 can lead to increased expression of VCAM and ICAM (selectins and _____ molecules) lead to extravasation of WBC into tissue.
Block this and WBC’s stay in blood vessels.
Adhesion
IL-1 increases bone erosion and activates RANK ligand and osteoclasts that digest _____ - can lead to osteoporosis.
Bone
IL-1 DOESN’T induce apoptosis but induces ___ which induces apoptosis (and septic shock)
TNF
IL-1 activation:
- Release of complement C5a due to activation of innate immune system (antigen/antibody driven)
- Complement can increase gene transcription of IL-1
- ______ feedback pathway
Positive
IL-1 release is increased in IFNg stimulated monocytes/_______.
T cells are main producers of IFNg (T cells activated, make more IFNg, feedback onto macrophages and produce more IL-1)
Macrophages
- CD40L activates ICE (interleukin 1 converting enzyme in endothelial cells and ___ ____ ___)
- CD40L is expressed on ___ cells.
Smooth muscle cells
TH2 cells (which activate B cells - lead to feedback and induces IL-1 release)
IL-1 receptors are members of the IG (________) superfamily.
Immunoglobulin