The mouse cathelicidin mCRAMP (LL-37 equivalent) was elevated in psoriatic skin and blood, directly activating platelets through FPR2/ALX receptors — linking antimicrobial peptides to blood clotting complications in inflammatory diseases.
FPR2/ALX-mediated activationCathelicidin activates platelets through FPR2/ALX receptors — blockade significantly reduced platelet activation in psoriatic mice
What the researchers found
mCRAMP levels were elevated in psoriatic mouse skin and plasma. Psoriatic plasma augmented platelet activation in healthy mouse platelets. The effect was partially mediated through Fpr2/3 (FPR2/ALX), as receptor inhibition or knockout significantly reduced platelet activation.
Why it matters
Cardiovascular complications are a major cause of morbidity in psoriasis and other inflammatory diseases. Identifying cathelicidin-FPR2/ALX as a driver of platelet activation reveals a potential therapeutic target.
The numbers in context
Elevated fibrinogen binding, P-selectin, soluble P-selectin, and CRAMP in psoriasis; partial inhibition by WRW4 and Fpr2/3 deficiency
How the study worked
Imiquimod-induced psoriasis mouse model. Measured platelet activation markers (fibrinogen binding, P-selectin), plasma and skin mCRAMP levels, and soluble P-selectin. Used FPR2/ALX inhibitors (WRW4) and Fpr2/3-deficient mice to validate receptor involvement.
Who was studied
Imiquimod-induced psoriasis mice, Fpr2/3-deficient mice, and healthy controls
What this study cannot tell us
Mouse model — mCRAMP and LL-37 are not identical. Psoriasis model (imiquimod) may not fully replicate human disease. FPR2/ALX blockade only partially reduced activation, suggesting other mechanisms. Clinical relevance in human psoriasis not validated.
How to read the evidence
Preliminary — mouse model with clear mechanistic data but no human validation of the cathelicidin-platelet-psoriasis link.
When this study was published
Published in 2020; the cardiovascular risk in psoriasis and the non-antimicrobial roles of cathelicidin continue to be investigated.
The bigger picture
This study reveals a previously unknown role for antimicrobial peptides in platelet biology and cardiovascular risk during inflammation. Since cathelicidin is elevated in psoriasis, atherosclerosis, and IBD, this mechanism could explain platelet complications across multiple diseases.
Questions still open
- Do psoriasis patients with higher LL-37 levels have more cardiovascular events?
- Could FPR2/ALX antagonists reduce thrombotic risk in inflammatory diseases?
- Does anti-platelet therapy in psoriasis patients work partly by blocking cathelicidin-platelet interactions?
Common questions
Why do psoriasis patients have higher blood clot risk?
What is FPR2/ALX and could it be a drug target?
Read the original research
The Antimicrobial Cathelicidin CRAMP Augments Platelet Activation during Psoriasis in Mice.
Biomolecules, 10(9)
Citation
Salamah, Maryam F; Vallance, Thomas M; Kodji, Xenia; Ravishankar, Divyashree; Williams, Harry F; Brain, Susan D; Vaiyapuri, Sakthivel. (2020). The Antimicrobial Cathelicidin CRAMP Augments Platelet Activation during Psoriasis in Mice.. Biomolecules, 10(9). https://doi.org/10.3390/biom10091267