Pharmacological Treatment with Annexin A1 Reduces Atherosclerotic Plaque Burden in LDLR-/- Mice on Western Type Diet

OBJECTIVE: To investigate therapeutic effects of annexin A1 (anxA1) on atherogenesis in LDLR-/- mice. METHODS: Human recombinant annexin A1 (hr-anxA1) was produced by a prokaryotic expression system, purified and analysed on phosphatidylserine (PS) binding and formyl peptide receptor (FPR) activation. Biodistribution of 99mTechnetium-hr-anxA1 was determined in C57Bl/6J mice. 12 Weeks old LDLR-/- mice were fed a Western Type Diet (WTD) during 6 weeks (Group I) or 12 weeks (Group P). Mice received hr-anxA1 (1 mg/kg) or vehicle by intraperitoneal injection 3 times per week for a period of 6 weeks starting at start of WTD (Group I) or 6 weeks after start of WTD (Group P). Total aortic plaque burden and phenotype were analyzed using immunohistochemistry. RESULTS: Hr-anxA1 bound PS in Ca2+-dependent manner and activated FPR2/ALX. It inhibited rolling and adherence of neutrophils but not monocytes on activated endothelial cells. Half lives of circulating 99mTc-hr-anxA1 were <10 minutes and approximately 6 hours for intravenously (IV) and intraperitoneally (IP) administered hr-anxA1, respectively. Pharmacological treatment with hr-anxA1 had no significant effect on initiation of plaque formation (-33%; P = 0.21)(Group I) but significantly attenuated progression of existing plaques of aortic arch and subclavian artery (plaque size -50%, P = 0.005; necrotic core size -76% P = 0.015, hr-anxA1 vs vehicle) (Group P). CONCLUSION: Hr-anxA1 may offer pharmacological means to treat chronic atherogenesis by reducing FPR-2 dependent neutrophil rolling and adhesion to activated endothelial cells and by reducing total plaque inflammation

Proposal to change the conserved type of Ipomoea, nom. cons. (Convolvulaceae)

Ipomoea L. is the largest (650–900 species, depending on the concept adopted) and most iconic genus in Convolvulaceae, a family of c. 1880 species (data from Staples, Convolvulaceae Unlimited, 2012 at: http//convolvulaceae.myspecies.info), including the important crop sweetpotato, Ipomoea batatas (L.) Lam. (Tabl. Encycl. 1: 465. 1793), and several ornamental species commonly known as “bindweeds” or “morning glories” (Wilkin in Kew Bull. 54: 853–876. 1999; Mabberley, Mabberley's Plant‐book. 2008). The genus has a long history of taxonomic and nomenclatural problems, mainly for the lack of a clear morphological circumscription and overlap with other genera. In his Species plantarum (1753), Linnaeus distinguished two genera, Convolvulus L. and Ipomoea, whose species suffered numerous re‐arrangements, between Ipomoea and Convolvulus, but especially into numerous more recently described genera, which amount today to a total of 60 (Staples in World Checklist of Vascular Plants, v.2.0. 2020, http://wcvp.science.kew.org/ retrieved 2 Apr 2020)