title: Biodistribution and Efficacy of Targeted Pulmonary Delivery of a Protein Kinase C-δ Inhibitory Peptide: Impact on Indirect Lung Injury.
abstract: Sepsis and sepsis-induced lung injury remain a leading cause of death in intensive care units. We identified protein kinase C-δ (PKCδ) as a critical regulator of the acute inflammatory response and demonstrated that PKCδ inhibition was lung-protective in a rodent sepsis model, suggesting that targeting PKCδ is a potential strategy for preserving pulmonary function in the setting of indirect lung injury. In this study, whole-body organ biodistribution and pulmonary cellular distribution of a transactivator of transcription (TAT)-conjugated PKCδ inhibitory peptide (PKCδ-TAT) was determined following intratracheal (IT) delivery in control and septic [cecal ligation and puncture (CLP)] rats to ascertain the impact of disease pathology on biodistribution and efficacy. There was negligible lung uptake of radiolabeled peptide upon intravenous delivery [<1% initial dose (ID)], whereas IT administration resulted in lung retention of >65% ID with minimal uptake in liver or kidney (<2% ID). IT delivery of a fluorescent-tagged (tetramethylrhodamine-PKCδ-TAT) peptide demonstrated uniform spatial distribution and cellular uptake throughout the peripheral lung. IT delivery of PKCδ-TAT at the time of CLP surgery significantly reduced PKCδ activation (tyrosine phosphorylation, nuclear translocation and cleavage) and acute lung inflammation, resulting in improved lung function and gas exchange. Importantly, peptide efficacy was similar when delivered at 4 hours post-CLP, demonstrating therapeutic relevance. Conversely, spatial lung distribution and efficacy were significantly impaired at 8 hours post-CLP, which corresponded to marked histopathological progression of lung injury. These studies establish a functional connection between peptide spatial distribution, inflammatory histopathology in the lung, and efficacy of this anti-inflammatory peptide.
authors.affiliation: Center for Inflammation, Clinical and Translational Lung Research (M.J.M., P.A.K., J.W., M.K., S.T.B., M.R.W., L.E.K.), Department of Physiology (M.J.M., P.A.K., J.W., S.T.B., M.R.W., L.E.K.), Sol Sherry Thrombosis Research Center (M.J.M., L.C.K., L.E.K.), Departments of Pediatrics and Medicine (M.R.W.), and Department of Radiology (L.C.K.), Temple University School of Medicine, Philadelphia, Pennsylvania.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Mondrinos
authors.affiliation: Center for Inflammation, Clinical and Translational Lung Research (M.J.M., P.A.K., J.W., M.K., S.T.B., M.R.W., L.E.K.), Department of Physiology (M.J.M., P.A.K., J.W., S.T.B., M.R.W., L.E.K.), Sol Sherry Thrombosis Research Center (M.J.M., L.C.K., L.E.K.), Departments of Pediatrics and Medicine (M.R.W.), and Department of Radiology (L.C.K.), Temple University School of Medicine, Philadelphia, Pennsylvania.
authors.forename: Linda C
authors.initials: LC
authors.lastname: Knight
authors.affiliation: Center for Inflammation, Clinical and Translational Lung Research (M.J.M., P.A.K., J.W., M.K., S.T.B., M.R.W., L.E.K.), Department of Physiology (M.J.M., P.A.K., J.W., S.T.B., M.R.W., L.E.K.), Sol Sherry Thrombosis Research Center (M.J.M., L.C.K., L.E.K.), Departments of Pediatrics and Medicine (M.R.W.), and Department of Radiology (L.C.K.), Temple University School of Medicine, Philadelphia, Pennsylvania.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Kennedy
authors.affiliation: Center for Inflammation, Clinical and Translational Lung Research (M.J.M., P.A.K., J.W., M.K., S.T.B., M.R.W., L.E.K.), Department of Physiology (M.J.M., P.A.K., J.W., S.T.B., M.R.W., L.E.K.), Sol Sherry Thrombosis Research Center (M.J.M., L.C.K., L.E.K.), Departments of Pediatrics and Medicine (M.R.W.), and Department of Radiology (L.C.K.), Temple University School of Medicine, Philadelphia, Pennsylvania.
authors.forename: Jichuan
authors.initials: J
authors.lastname: Wu
authors.affiliation: Center for Inflammation, Clinical and Translational Lung Research (M.J.M., P.A.K., J.W., M.K., S.T.B., M.R.W., L.E.K.), Department of Physiology (M.J.M., P.A.K., J.W., S.T.B., M.R.W., L.E.K.), Sol Sherry Thrombosis Research Center (M.J.M., L.C.K., L.E.K.), Departments of Pediatrics and Medicine (M.R.W.), and Department of Radiology (L.C.K.), Temple University School of Medicine, Philadelphia, Pennsylvania.
authors.forename: Matthew
authors.initials: M
authors.lastname: Kauffman
authors.affiliation: Center for Inflammation, Clinical and Translational Lung Research (M.J.M., P.A.K., J.W., M.K., S.T.B., M.R.W., L.E.K.), Department of Physiology (M.J.M., P.A.K., J.W., S.T.B., M.R.W., L.E.K.), Sol Sherry Thrombosis Research Center (M.J.M., L.C.K., L.E.K.), Departments of Pediatrics and Medicine (M.R.W.), and Department of Radiology (L.C.K.), Temple University School of Medicine, Philadelphia, Pennsylvania.
authors.forename: Sandy T
authors.initials: ST
authors.lastname: Baker
authors.affiliation: Center for Inflammation, Clinical and Translational Lung Research (M.J.M., P.A.K., J.W., M.K., S.T.B., M.R.W., L.E.K.), Department of Physiology (M.J.M., P.A.K., J.W., S.T.B., M.R.W., L.E.K.), Sol Sherry Thrombosis Research Center (M.J.M., L.C.K., L.E.K.), Departments of Pediatrics and Medicine (M.R.W.), and Department of Radiology (L.C.K.), Temple University School of Medicine, Philadelphia, Pennsylvania.
authors.forename: Marla R
authors.initials: MR
authors.lastname: Wolfson
authors.affiliation: Center for Inflammation, Clinical and Translational Lung Research (M.J.M., P.A.K., J.W., M.K., S.T.B., M.R.W., L.E.K.), Department of Physiology (M.J.M., P.A.K., J.W., S.T.B., M.R.W., L.E.K.), Sol Sherry Thrombosis Research Center (M.J.M., L.C.K., L.E.K.), Departments of Pediatrics and Medicine (M.R.W.), and Department of Radiology (L.C.K.), Temple University School of Medicine, Philadelphia, Pennsylvania laurie.kilpatrick@temple.edu.
authors.forename: Laurie E
authors.initials: LE
authors.lastname: Kilpatrick
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D001692:Biological Transport; D018450:Disease Progression; D004305:Dose-Response Relationship, Drug; D015696:Gene Products, tat / Q000737:chemistry; D008168:Lung / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D055370:Lung Injury / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008297:Male; D010446:Peptide Fragments / Q000378:metabolism / Q000493:pharmacokinetics* / Q000494:pharmacology* / Q000627:therapeutic use; D011014:Pneumonia / Q000188:drug therapy / Q000382:microbiology; D051745:Protein Kinase C-delta / Q000037:antagonists & inhibitors*; D047428:Protein Kinase Inhibitors / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use; D011659:Pulmonary Gas Exchange / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D018805:Sepsis / Q000188:drug therapy; D013667:Technetium / Q000737:chemistry; D014018:Tissue Distribution
chemical_list: D000893:Anti-Inflammatory Agents; D015696:Gene Products, tat; D010446:Peptide Fragments; D047428:Protein Kinase Inhibitors; D013667:Technetium; D051745:Protein Kinase C-delta