L9 Targeting NLRP3 Inflammasome

Question 1

__ tend to activate the inflammasome

Answer 1

DAMPs

Question 2

The priming signal leads to…

Answer 2

increased transcription of NLRP3 gene (via NF-κβ activation)

Question 3

Post-translational modifications that stabilise the inflammasome

Answer 3

Phosphorylation and ubiquitylation

Question 4

NLRP3 inflammasome activation leads to release of which pro-inflammatory cytokines?

Answer 4

IL-1β and IL-18

Question 5

NLRP3 contains an amino-terminal __ domain

Answer 5

pyrin

Question 6

NLRP3 inflammasome components

Answer 6

• sensor molecule (NLRP3)
• adaptor molecule (ASC)
• effector molecule (caspase 1)

Question 7

NLRP3 NACHT domain contains __ activity

Answer 7

ATPase

Question 8

ASC proteolytically cleaves __ , which cleaves pro-IL-1β and pro-IL-18

Answer 8

caspase 1

Question 9

NLRP3 binds to __ to secure structure and recruit ASC

Answer 9

NEK7

Question 10

Inflammatory cell death

Answer 10

pyroptosis

Question 11

Rate-limiting step in activating the inflammasome

Answer 11

The amount of NLRP3 expressed (abundance of NLRP3 gene)

Question 12

Predominant function of a secondary signal

Answer 12

Help recruit ASC component and ultimately cleave procaspase 1

Question 13

Most abundance and best described secondary signal

Answer 13

Efflux of K⁺ out of primed cell to activate NLRP3 inflammasome

Question 14

Caspase 1 also cleaves __ , which inserts into the membrane and forms pores.

Answer 14

Gasdermin D (GSDMD)

Question 15

__ position in LRR domain inhibits activation of NLRP3

Answer 15

Y861

Question 16

Phosphorylation at S295 in NACHT domain by __ inhibits NLRP3

Answer 16

PKA (while PKD activates NLRP3)

Question 17

__ at S198 in linker region between NACHT and pyrin domains inhibits NLRP3

Answer 17

Dephosphorylation

Question 18

Unifying factor of NLRP3 activators

Answer 18

they all induce cellular stress, which is then sensed by NLRP3

Question 19

Most common activating stimuli for NLRP3

Answer 19

• Potassium efflux
• Cathepsin release
• Mitochondrial dysfunction
• Metabolic changes

Question 20

Examples of second signals

Answer 20

• K⁺ efflux and pore formation
• Lysosomal disruption
• Mitochondrial dysfunction
• Metabolic changes e.g. SCFAs

Question 21

Saturated fatty acid, palmitate, __ NLRP3 priming

Answer 21

activates

Question 22

SCFAs, butyrate and propionate, __ NLRP3 priming

Answer 22

inhibit

Question 23

Example of a ketone body that inhibits NLRP3

Answer 23

β-hydroxybutyrate (BHB) (via inhibition of K⁺ efflux)

Question 24

What is CAPS?

Answer 24

Cryopryin-associated periodic syndromes (caused by gain-of function mutations in NLRP3 gene)

Question 25

Increased IL-18 found in patients with __

Answer 25

Crohn's disease

Question 26

NLRP3-activating crystals in atherosclerosis

Answer 26

Cholesterol crystals

Question 27

NLRP3-activating crystals in gout

Answer 27

Monosodium urate crystals

Question 28

NLRP3-activating crystals in kidney dysfunction

Answer 28

Calcium oxalate crystals

Question 29

3 biologics that target the IL-1 signalling pathway

Answer 29

- Anakinra (IL-1R antagonist) - Rilonacept (soluble decoy receptor that binds both IL-1β & IL-1α) - Canakinumab (IL-1β nAb)

Question 30

Advantage of Canakinumab over Anakinra

Answer 30

Longer half-life (26h vs 4-6h) - less frequent dosing

Question 31

Pharmacological agents that directly inhibit NLRP3 activation

Answer 31

- MCC950 - Glyburide - OLT1177 (Dapansutrile)

Question 32

What is Dapansutrile?

Answer 32

- Orally active β-sulfonyl nitrile molecule that inhibits NLRP3 activation (upstream of ASC), which reduces caspase 1 activity & subsequent IL-1β release - Good safety profile in patients with gout but quite a high dose needed

Question 33

What is glyburide?

Answer 33

- Potently inhibits NLRP3 activation (by blocking K⁺ efflux), but requires high doses - Commonly used to treat T2DM (associated hypoglycaemia)

Question 34

What is MCC950?

Answer 34

- Diarylsulfonylurea small molecule compound – most potent and specific NLRP3 inhibitor - Binds NLRP3 and blocks its ability to hydrolyse ATP (causing instability) - Inhibits ATP-triggered, NLRP3-mediated IL-1β release in monocytes

Question 35

Main issue with MCC950

Answer 35

Hepatotoxicity