MyJournals Home  

RSS FeedsIJMS, Vol. 22, Pages 9999: Intranasal Delivery of RGD-Containing Osteopontin Heptamer Peptide Confers Neuroprotection in the Ischemic Brain and Augments Microglia M2 Polarization (International Journal of Molecular Sciences)

 
 

16 september 2021 11:20:35

 
IJMS, Vol. 22, Pages 9999: Intranasal Delivery of RGD-Containing Osteopontin Heptamer Peptide Confers Neuroprotection in the Ischemic Brain and Augments Microglia M2 Polarization (International Journal of Molecular Sciences)
 


Osteopontin (OPN), a phosphorylated glycoprotein, is induced in response to tissue damage and inflammation in various organs, including the brain. In our previous studies, we reported the robust neuroprotective effects of the icosamer OPN peptide OPNpt20, containing arginine-glycine-aspartic acid (RGD) and serine-leucine-alanine-tyrosine (SLAY) motifs, in an animal model of transient focal ischemia and demonstrated that its anti-inflammatory, pro-angiogenic, and phagocytosis inducing functions are responsible for the neuroprotective effects. In the present study, we truncated OPNpt20 to 13 or 7 amino acid peptides containing RGD (R) and/or SLAY (S) motifs (OPNpt13RS, OPNpt7R, OPNpt7RS, and OPNpt7S), and their neuroprotective efficacy was examined in a rat middle cerebral artery occlusion (MCAO) model. Intranasal administration of all four peptides significantly reduced infarct volume; OPNpt7R (VPNGRGD), the 7-amino-acid peptide containing an RGD motif, was determined to be the most potent, with efficacy comparable to that of OPNpt20. Additionally, sensory–motor functional deficits of OPNpt7R-administered MCAO animals were significantly improved, as indicated by the modified neurological severity scores and rotarod test. Notably, the expression of M1 markers was suppressed, whereas that of M2 markers (Arginase 1, CD206, and VEGF) was significantly enhanced in OPNpt7R-treated primary microglia cultures. Inflammation resolution by OPNpt7R was further confirmed in MCAO animals, in which upregulation of anti-inflammatory cytokines (Arg1, IL-10, IL-4, and CD36) and enhanced efferocytosis were detected. Moreover, studies using three mutant peptides (OPNpt7R-RAA or OPNpt7R-RAD, where RGD was replaced with RAA or RAD, respectively, and OPNpt7R-sc containing scrambled sequences) revealed that the RGD motif plays a vital role in conferring neuroprotection. In conclusion, the RGD-containing OPN heptamer OPNpt7R exhibits neuroprotective effects in the post-ischemic brain by suppressing M1 markers and augmenting M2 polarization of microglia and the RGD motif plays a critical role in these activities.


 
57 viewsCategory: Biochemistry, Biophysics, Molecular Biology
 
IJMS, Vol. 22, Pages 10000: Oxytocin and Fear Memory Extinction: Possible Implications for the Therapy of Fear Disorders? (International Journal of Molecular Sciences)
IJMS, Vol. 22, Pages 10001: Mechanistic Insights into Axenfeld–Rieger Syndrome from Zebrafish foxc1 and pitx2 Mutants (International Journal of Molecular Sciences)
 
 
blog comments powered by Disqus


MyJournals.org
The latest issues of all your favorite science journals on one page

Username:
Password:

Register | Retrieve

Search:

Molecular Biology


Copyright © 2008 - 2021 Indigonet Services B.V.. Contact: Tim Hulsen. Read here our privacy notice.
Other websites of Indigonet Services B.V.: Nieuws Vacatures News Tweets Nachrichten