Signaling mechanisms in Streptococcal M1 proteininduced inflammation and injury in the lung
Författare
Summary, in English
Streptococcus pyogenes of the M1 serotype is frequently associated with severe streptococcal infections.
Acute lung injury is recognized as a key component in the pathophysiology of streptococcal M1 proteininduced
inflammation. Numerous reports have demonstrated that excessive infiltration of neutrophils is a
rate-limiting step in septic lung damage. We observed that targeting neutrophil functions appeared more
relevant than inhibiting platelet activation in severe infections triggered by streptococcal M1 protein. In study
II, it was shown that simvastatin was a powerful inhibitor of neutrophil infiltration in acute lung damage
triggered by streptococcal M1 protein. The inhibitory effect of simvastatin on M1 protein-induced neutrophil
recruitment appeared related to reduced pulmonary generation of CXC chemokines. Following the mevalonate
signaling pathway, checking downstream effectors, both Rho/Rho Kinase and p38 MAPK signaling pathway
played critical roles in M1 protein-induced lung recruitment of neutrophils via formation of CXC chemokines
and Mac-1 expression. In addition, our findings also suggested that farnesyltransferase was a potent regulator
of CXC chemokine formation in alveolar macrophages and that inhibition of farnesyltransferase not only
reduces neutrophil recruitment but also attenuates acute lung injury provoked by streptococcal M1 protein.
Thus, these new data may provide a basis for the development of more specific and effective treatment of
patients with STSS.
Acute lung injury is recognized as a key component in the pathophysiology of streptococcal M1 proteininduced
inflammation. Numerous reports have demonstrated that excessive infiltration of neutrophils is a
rate-limiting step in septic lung damage. We observed that targeting neutrophil functions appeared more
relevant than inhibiting platelet activation in severe infections triggered by streptococcal M1 protein. In study
II, it was shown that simvastatin was a powerful inhibitor of neutrophil infiltration in acute lung damage
triggered by streptococcal M1 protein. The inhibitory effect of simvastatin on M1 protein-induced neutrophil
recruitment appeared related to reduced pulmonary generation of CXC chemokines. Following the mevalonate
signaling pathway, checking downstream effectors, both Rho/Rho Kinase and p38 MAPK signaling pathway
played critical roles in M1 protein-induced lung recruitment of neutrophils via formation of CXC chemokines
and Mac-1 expression. In addition, our findings also suggested that farnesyltransferase was a potent regulator
of CXC chemokine formation in alveolar macrophages and that inhibition of farnesyltransferase not only
reduces neutrophil recruitment but also attenuates acute lung injury provoked by streptococcal M1 protein.
Thus, these new data may provide a basis for the development of more specific and effective treatment of
patients with STSS.
Avdelning/ar
Publiceringsår
2012
Språk
Engelska
Publikation/Tidskrift/Serie
Lund University Faculty of Medicine Doctoral Dissertation Series
Volym
2012:104
Dokumenttyp
Doktorsavhandling
Förlag
Surgery Research Unit, Clinical Science, Malmö
Ämne
- Surgery
Status
Published
Forskningsgrupp
- Surgery
Handledare
ISBN/ISSN/Övrigt
- ISSN: 1652-8220
- ISBN: 978-91-87189-67-8
Försvarsdatum
30 november 2012
Försvarstid
13:00
Försvarsplats
CRC Aula, Entrance 72, Skåne University Hospital, Malmö
Opponent
- Malin Sund