title: Doxycycline protects human intestinal cells from hypoxia/reoxygenation injury: Implications from an in-vitro hypoxia model.
abstract: Intestinal ischemia/reperfusion (I/R) injury is a grave clinical emergency and associated with high morbidity and mortality rates. Based on the complex underlying mechanisms, a multimodal pharmacological approach seems necessary to prevent intestinal I/R injury. The antibiotic drug doxycycline, which exhibits a wide range of pleiotropic therapeutic properties, might be a promising candidate for also reducing I/R injury in the intestine. To investigate possible protective effects of doxycycline on intestinal I/R injury, human intestinal CaCo-2 cells were exposed to doxycycline at clinically relevant concentrations. In order to mimic I/R injury, CaCo-2 were thereafter subjected to hypoxia/reoxygenation by using our recently described two-enzyme in-vitro hypoxia model. Investigations of cell morphology, cell damage, apoptosis and hydrogen peroxide formation were performed 24h after the hypoxic insult. Hypoxia/reoxygenation injury resulted in morphological signs of cell damage, elevated LDH concentrations in the respective culture media (P<0.001) and increased protein expression of proapoptotic caspase-3 (P<0.05) in the intestinal cultures. These events were associated with increased levels hydrogen peroxide (P<0.001). Preincubation of CaCo-2 cells with different concentrations of doxycycline (5µM, 10µM, 50µM) reduced the hypoxia induced signs of cell damage and LDH release (P<0.001 for all concentrations). The reduction of cellular damage was associated with a reduced expression of caspase-3 (5µM, P<0.01; 10µM, P<0.01; 50µM, P<0.05), while hydrogen peroxide levels remained unchanged. In summary, doxycycline protects human intestinal cells from hypoxia/reoxygenation injury in-vitro. Further animal and clinical studies are required to prove the protective potential of doxycycline on intestinal I/R injury under in-vivo conditions.
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Hummitzsch
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
authors.forename: Karina
authors.initials: K
authors.lastname: Zitta
authors.affiliation: Department of Cardiovascular Surgery, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
authors.forename: Rouven
authors.initials: R
authors.lastname: Berndt
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Kott
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
authors.forename: Christin
authors.initials: C
authors.lastname: Schildhauer
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Parczany
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Steinfath
authors.affiliation: Department of Anaesthesiology and Intensive Care Medicine, University Hospital Schleswig-Holstein, Campus Kiel, Germany. Electronic address: martin.albrecht@uksh.de.
authors.forename: Martin
authors.initials: M
authors.lastname: Albrecht
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D018938:Caco-2 Cells; D053148:Caspase 3 / Q000096:biosynthesis; D015687:Cell Hypoxia / Q000187:drug effects; D004318:Doxycycline / Q000008:administration & dosage*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D007422:Intestines / Q000187:drug effects* / Q000293:injuries / Q000473:pathology; D019194:Ischemic Preconditioning; D020011:Protective Agents / Q000008:administration & dosage; D015427:Reperfusion Injury / Q000188:drug therapy* / Q000473:pathology
chemical_list: D020011:Protective Agents; D006861:Hydrogen Peroxide; D053148:Caspase 3; D004318:Doxycycline
keywords: Cell protection; Doxycycline; Hypoxia; Intestinal cells; Intestinal ischemia; Ischemia/reperfusion injury