title: Determination of tissue levels of a neuroprotectant drug: the cell permeable JNK inhibitor peptide.
abstract: BACKGROUND
  Cell permeable peptides (CPPs) represent a novel tool for the delivery of bioactive molecules into scarcely accessible organs, such as the brain. CPPs have been successfully used in pre-clinical studies for a variety of diseases, ranging from cancer to neurological disorders. However, the mechanisms by which CPPs cross biological membranes, as well as their pharmacokinetic properties, have been poorly explored due to the lack of specific and sensitive analytical methods.
  
  
  METHODS
  In this paper we describe a protocol to quantitatively determine the amount of CPPs in in vitro and in vivo experimental models. To this end we selected the peptide D-JNKI1 that was shown to prevent neurodegeneration in both acute and chronic degenerative disorders. This method allows an accurate quantitative analysis of D-JNKI1 in both neuronal lysates and tissue homogenates using mass spectrometry and stable isotope dilution approach.
  
  
  RESULTS
  We found that D-JNKI1 crosses cellular membranes with fast kinetics, through an active and passive mechanism. After acute intraperitoneal (ip) administration of D-JNKI1 in mice, the peptide was found in the main organs with particular regard to the liver and kidney. Interestingly, D-JNKI1 crosses the blood brain barrier (BBB) and reaches the brain, where it remains for one week.
  
  
  CONCLUSIONS
  The challenge lies in developing the clinical application of therapeutic cell permeable peptides. Discerning pharmacokinetic properties is a high priority to produce a powerful therapeutic strategy. Overall, our data shed light on the pharmacokinetic properties of D-JNKI1 and supports its powerful neuroprotective effect.
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milano, Italy.
authors.forename: Enrico
authors.initials: E
authors.lastname: Davoli
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milano, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Sclip
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milano, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Cecchi
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milano, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Cimini
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milano, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Carrà
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milano, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Salmona
authors.affiliation: IRCCS - Istituto di Ricerche Farmacologiche "Mario Negri", Via La Masa 19, 20156 Milano, Italy. Electronic address: tiziana.borsello@marionegri.it.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Borsello
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001812:Blood-Brain Barrier / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects*; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D051379:Mice; D009474:Neurons / Q000187:drug effects; D018696:Neuroprotective Agents / Q000378:metabolism* / Q000494:pharmacology*; D010455:Peptides / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: D018696:Neuroprotective Agents; D010455:Peptides; C478085:D-JNKI-1
keywords: Cell permeable peptide; D-JNKI1; In vivo sensitive analytic method; Mass spectrometry; Neurons; Pharmacokinetics