Δημή ριος Σάκος , fesc, fscai Επ. καθηηής Καριολοίας...
TRANSCRIPT
Ο ρόλος των ουδετερόφιλων στην θρόμβωση
Δημήτριος Στάκος, FESC, FSCAIΕπ. καθηγητής ΚαρδιολογίαςΔ.Π.Θ. Αλεξανδρούπολη
Αιμόσταση vs θρόμβωση
Αγγειακός ιστικός παράγοντας (TF) και blood-born TF
Αιμόσταση vs θρόμβωση
Η συμμετοχή ανοσιακών διαδικασιών βασική διαφορά μεταξύ αιμόστασης - θρόμβωσης
Ποια είναι η σημασία των κυττάρων της φυσικής ανοσίας στη θρόμβωση ?
Pawlinski R, et al. Blood, 2010
Control mice transplanted with low-hTF bone marrow cells
Hematopoietic TF, but not vessel wall TF is responsible for initiation of DVT
ctrl ctrl +BM
(low TF)
Neutropenic mice and thrombus size
* Ab to deplete neutrophils
anti-Ly6G antibody*
*
von Brühl, et al. J Exp Med. 2012
How innate immune cells initiate DVT development ? The significance of TF
Furie B. J Thromb. Haemost. 2007Manly DA. Annu. Rev. Physiol 2011
Fibrin formation
ctrl
ctrl
What signals supporting thrombogenesis are delivered by neutrophils?
Darbousset R, et al. Blood 2012
PMNs expressing TF is the main source of TF needed for platelet thrombus formation and fibrin generation following a laser-induced injury in vivo.
Encrypted TF
Brinkmann V, et al. Neutrophil extracellular traps kill bacteria. Science 2004
Neutrophil-derived structures composed of extruded DNA, decorated with antimicrobial proteins
NET’s function
High local concentration of antimicrobial components
Kill microbes extracellularly independent of phagocytic uptake
Physical barrier that prevents further spread of the pathogens
Delivery of granule proteins into NETs (keep injurious proteins - proteases from diffusing)
Less energy consuming
PMN
Pathogen
NET formation
Firm attachment to the substratum
Disintegration of membranes - mixture
Cell contraction –membrane rupture
Brinkmann V. J Cell Biol. 2012
Our hypothesis
Normal artery
of the same patient
Culprit lesion in Lcx
(STEMI)
NETS in STEMI
MP
O/D
NA
co
mp
lex
ELIS
A
Στην ένοχη αρτηρία υπάρχει σημαντική απελευθέρωση ΝΕΤs (τοπικά)
Έκφραση ιστικού παράγοντα στα STEMI NETs
Παραγωγή θρομβίνης (ενεργότητα TF)
Ο ιστικός παράγοντας στα NETs είναι ενεργός και η ενεργότητα του εξαρτάται από το ΝΕΤ
Ενεργοποίηση αιμοπεταλίων (ενεργότητα TF)
Ο ιστικός παράγοντας στα NETs είναι ενεργός και η ενεργότητα του εξαρτάται από το ΝΕΤ
ΝΕΤs με ιστικό παράγοντα μέσα στο θρόμβο
Intracellular TF upregulation in circulatinh PMNs of STEMIC
ircu
lati
ng
PM
Ns
STEM
I
TF mRNA (PCR)
Western
1st stimulus intracellular TF upregulation (systemic)
2nd stimulus (highly local) release of NETs expressing TF thrombosis
A mechanism for TF-bearing NET release in STEMI
A substance in STEMI plasma (inflammatory) is responsible for the 1st hit
NETs in arterial thrombosis
Platelet aggregation (RED)
Activated platelets induce the formation of NETs not expressing TF in the absence of the 1st hit (STEMI plasma)
In vitro reproduction of double hit phenomenon
IRA-derived platelets
Conclusions
1. Abundant NET release in IRA of STEMI patients
2. Local phenomenon
3. Functional TF is expressed on NETs able to induce thrombin generation and PLT activation into thrombus
4. Thrombin-activated platelets induce more NET release in a vicious cycle
5. NET (DNA) scaffold in imperative for TF functionality
6. TF-bearing NET release is a double-hit mechanism
initial intracellular TF upregulation is followed by TF-bearing NET release
7. DNase treatment may potentiated the effects of current antithrombotic treatment
8. NETs may represent another mechanism that link thrombosis-inflammation and innate immunity
Do PMNs regulate the delivery of intracellular substances on their NETs depending on the circumstances?
PMNs
NETs decorated with anti-microbial enzymes (NE, MPO)
NETosis
Pathogen invasion
Elimination
Sterile inflammation
NETs decorated with prothrombotic material (TF) Thrombosis
INFLAMMATION
Thrombosis
NETs exposing TF
Intracellular TF
TF gene
NETs as a possible link between innate immunity and Thrombosis
Microcirculation
Platelets
PMNs
Sterile
Ruptured atherosclerotic plaque
Pathogen invasion
Vascular wall
Vasculitis
Microcirculation
DVT/arterial thrombosis/STEMI
NETosis
Sepsis
Large vessels
Thrombosis
Sh2-199, Soul NebulaIC 1848. NASA
Baboon DVT Immunostaining DNA/Histone and VWF
Baboon DVTStaining for extracellular DNA
NGC 6334 "Cat's Paw Nebula", Scorpius Constellation - NASA