title: Development of second generation peptides modulating cellular adiponectin receptor responses.
abstract: The adipose tissue participates in the regulation of energy homeostasis as an important endocrine organ that secretes a number of biologically active adipokines, including adiponectin. Recently we developed and characterized a first-in-class peptide-based adiponectin receptor agonist by using in vitro and in vivo models of glioblastoma and breast cancer (BC). In the current study, we further explored the effects of peptide ADP355 in additional cellular models and found that ADP355 inhibited chronic myeloid leukemia (CML) cell proliferation and renal myofibroblast differentiation with mid-nanomolar IC50 values. According to molecular modeling calculations, ADP355 was remarkably flexible in the global minimum with a turn present in the middle of the peptide. Considering these structural features of ADP355 and the fact that adiponectin normally circulates as multimeric complexes, we developed and tested the activity of a linear branched dimer (ADP399). The dimer exhibited approximately 20-fold improved cellular activity inhibiting K562 CML and MCF-7 cell growth with high pM-low nM relative IC50 values. Biodistribution studies suggested superior tissue dissemination of both peptides after subcutaneous administration relative to intraperitoneal inoculation. After screening of a 397-member adiponectin active site library, a novel octapeptide (ADP400) was designed that counteracted 10-1000 nM ADP355- and ADP399-mediated effects on CML and BC cell growth at nanomolar concentrations. ADP400 induced mitogenic effects in MCF-7 BC cells perhaps due to antagonizing endogenous adiponectin actions or acting as an inverse agonist. While the linear dimer agonist ADP399 meets pharmacological criteria of a contemporary peptide drug lead, the peptide showing antagonist activity (ADP400) at similar concentrations will be an important target validation tool to study adiponectin functions.
authors.affiliation: Department of Biology, Temple University Philadelphia, PA, USA.
authors.forename: Laszlo
authors.initials: L
authors.lastname: Otvos
authors.affiliation: Faculty of Chemistry and Mineralogy, Center for Biotechnology and Biomedicine, Institute of Bioanalytical Chemistry, Universität Leipzig Leipzig, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Knappe
authors.affiliation: Faculty of Chemistry and Mineralogy, Center for Biotechnology and Biomedicine, Institute of Bioanalytical Chemistry, Universität Leipzig Leipzig, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Hoffmann
authors.affiliation: 1st Institute of Pathology and Experimental Cancer Research, Faculty of Medicine, Semmelweis University Budapest, Hungary.
authors.forename: Ilona
authors.initials: I
authors.lastname: Kovalszky
authors.affiliation: 1st Institute of Pathology and Experimental Cancer Research, Faculty of Medicine, Semmelweis University Budapest, Hungary.
authors.forename: Julia
authors.initials: J
authors.lastname: Olah
authors.affiliation: Department of Medicine, The University of Melbourne Melbourne, VIC, Australia.
authors.forename: Tim D
authors.initials: TD
authors.lastname: Hewitson
authors.affiliation: Torrey Pines Institute for Molecular Studies Port St. Lucie, Florida, FL, USA.
authors.forename: Roma
authors.initials: R
authors.lastname: Stawikowska
authors.affiliation: Torrey Pines Institute for Molecular Studies Port St. Lucie, Florida, FL, USA.
authors.forename: Maciej
authors.initials: M
authors.lastname: Stawikowski
authors.affiliation: Torrey Pines Institute for Molecular Studies Port St. Lucie, Florida, FL, USA.
authors.forename: Predrag
authors.initials: P
authors.lastname: Cudic
authors.affiliation: Florey Institute of Neuroscience and Mental Health and School of Chemistry, The University of Melbourne Melbourne, VIC, Australia.
authors.forename: Feng
authors.initials: F
authors.lastname: Lin
authors.affiliation: Florey Institute of Neuroscience and Mental Health and School of Chemistry, The University of Melbourne Melbourne, VIC, Australia.
authors.forename: John D
authors.initials: JD
authors.lastname: Wade
authors.affiliation: Sbarro Institute for Cancer Research and Molecular Medicine, Temple University Philadelphia, PA, USA.
authors.forename: Eva
authors.initials: E
authors.lastname: Surmacz
authors.affiliation: Department of Biomedical Sciences, Creighton University NE, USA.
authors.forename: Sandor
authors.initials: S
authors.lastname: Lovas
keywords: antiproliferation; biodistribution; dimeric peptide; molecular dynamics simulations; nanomolar activity