Genetic and pharmacological inhibition of CDK9 drives neutrophil apoptosis to resolve inflammation in zebrafish in vivo.
Neutrophilic inflammation is tightly regulated and subsequently resolves to limit tissue damage and promote repair. When the timely resolution of inflammation is dysregulated, tissue damage and disease results. One key control mechanism is neutrophil apoptosis, followed by apoptotic cell clearance by phagocytes such as macrophages. Cyclin-dependent kinase (CDK) inhibitor drugs induce neutrophil apoptosis in vitro and promote resolution of inflammation in rodent models. Here we present the first in vivo evidence, using pharmacological and genetic approaches, that CDK9 is involved in the resolution of neutrophil-dependent inflammation. Using live cell imaging in zebrafish with labelled neutrophils and macrophages, we show that pharmacological inhibition, morpholino-mediated knockdown and CRISPR/cas9-mediated knockout of CDK9 enhances inflammation resolution by reducing neutrophil numbers via induction of apoptosis after tailfin injury. Importantly, knockdown of the negative regulator La-related protein 7 (LaRP7) increased neutrophilic inflammation. Our data show that CDK9 is a possible target for controlling resolution of inflammation.
MRC Centre for Inflammation Research, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, EH16 4TJ, United Kingdom.
Laura J
LJ
Hoodless
MRC Centre for Inflammation Research, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, EH16 4TJ, United Kingdom.
Christopher D
CD
Lucas
MRC Centre for Inflammation Research, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, EH16 4TJ, United Kingdom.
Rodger
R
Duffin
BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, EH16 4TJ, United Kingdom.
Martin A
MA
Denvir
MRC Centre for Inflammation Research, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, EH16 4TJ, United Kingdom.
Christopher
C
Haslett
BHF Centre for Cardiovascular Science, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, EH16 4TJ, United Kingdom.
Carl S
CS
Tucker
MRC Centre for Inflammation Research, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, EH16 4TJ, United Kingdom.
Adriano G
AG
Rossi
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D064113:CRISPR-Cas Systems; D042863:Cyclin-Dependent Kinase 9 / Q000235:genetics* / Q000378:metabolism*; D004195:Disease Models, Animal; D005419:Flavonoids / Q000494:pharmacology; D055785:Gene Knockdown Techniques / Q000379:methods*; D007249:Inflammation / Q000276:immunology* / Q000378:metabolism; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009504:Neutrophils / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011720:Pyrazoles / Q000494:pharmacology; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism*
C531230:4-(2,6-dichlorobenzoylamino)-1H-pyrazole-3-carboxylic acid piperidin-4-ylamide; D005419:Flavonoids; D010880:Piperidines; D047428:Protein Kinase Inhibitors; D011720:Pyrazoles; D012261:Ribonucleoproteins; D029961:Zebrafish Proteins; C077990:alvocidib; C517155:Cdk9 protein, zebrafish; D042863:Cyclin-Dependent Kinase 9