Acute systemic knockdown of <i>Atg7</i> is lethal and causes pancreatic destruction in shRNA transgenic mice
Creators: name: Mainz, Laura
name: Sarhan, Mohamed A. F. E.
name: Roth, Sabine
name: Sauer, Ursula
name: Kalogirou, Charis
name: Eckstein, Markus
name: Gerhard-Hartmann, Elena
name: Seibert, Helen-Desiree
name: Voelker, Hans-Ulrich
name: Geppert, Carol
name: Rosenwald, Andreas
name: Eilers, Martin
name: Schulze, Almut
name: Diefenbacher, Markus
name: Rosenfeldt, Mathias T.
Publisher: name: Taylor & Francis
Year: 2022
Subjects: subject: Biochemistry
subject: Cell Biology
subject: Genetics
subject: FOS: Biological sciences
subject: Pharmacology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Immunology
subject: FOS: Clinical medicine
subject: Biological Sciences not elsewhere classified

description: The notion that macroautophagy/autophagy is a potentially attractive therapeutic target for a variety of diseases, including cancer, largely stems from pre-clinical mouse studies. Most of these examine the effects of irreversible and organ confined autophagy deletion using site specific <i>Cre</i>-loxP recombination of the essential autophagy regulating genes <i>Atg7</i> or <i>Atg5</i>. Model systems with the ability to impair autophagy systemically and reversibly at all disease stages would allow a more realistic approach to evaluate the consequences of authophagy inhibition as a therapeutic concept and its potential side effects. Here, we present shRNA transgenic mice that via doxycycline (DOX) regulable expression of a highly efficient miR30-E-based shRNA enabled knockdown of <i>Atg7</i> simultaneously in the majority of organs, with the brain and spleen being noteable exceptions. Induced animals deteriorated rapidly and experienced profound destruction of the exocrine pancreas, severe hypoglycemia and depletion of hepatic glycogen storages. Cessation of DOX application restored apparent health, glucose homeostasis and pancreatic integrity. In a similar <i>Atg5</i> knockdown model we neither observed loss of pancreatic integrity nor diminished survival after DOX treatment, but identified histological changes consistent with steatohepatitis and hepatic fibrosis in the recovery period after termination of DOX. Regulable <i>Atg7</i>-shRNA mice are valuable tools that will enable further studies on the role of autophagy impairment at various disease stages and thereby help to evaluate the consequences of acute autophagy inhibition as a therapeutic concept. <b>Abbreviations:</b> ACTB: actin, beta; AMY: amylase complex; ATG4B: autophagy related 4B, cysteine peptidase; ATG5: autophagy related 5; ATG7: autophagy related 7; Cag: CMV early enhancer/chicken <i>ACTB</i> promoter; <i>Col1a1</i>: collagen, type I, alpha 1; Cre: cre recombinase; DOX: doxycycline; GCG: glucagon; GFP: green fluorescent protein; INS: insulin; LC3: microtubule-associated protein 1 light chain 3; miR30-E: optimized microRNA backbone; NAFLD: non-alcoholic fatty liver disease; NASH: non-alcoholic steatohepatitis; PNLIP: pancreatic lipase; rtTA: reverse tetracycline transactivator protein; SQSTM1/p62: sequestome 1; TRE: tetracycline responsive element.