SKI activates the Hippo pathway via LIMD1 to inhibit cardiac fibroblast activation.

Autor: Landry NM; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada.; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada.; Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada., Rattan SG; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada.; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada.; Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada., Filomeno KL; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada.; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada.; Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada., Meier TW; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada.; Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada., Meier SC; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada.; Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada., Foran SJ; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada., Meier CF; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada., Koleini N; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada.; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada.; Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada., Fandrich RR; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada., Kardami E; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada.; Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada.; Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada., Duhamel TA; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada.; Faculty of Kinesiology and Recreation Management, University of Manitoba, Winnipeg, Canada., Dixon IMC; Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, 351 Taché Avenue, Winnipeg, MB, Canada. idixon@sbrc.ca.; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Canada. idixon@sbrc.ca.; Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada. idixon@sbrc.ca.
Jazyk: angličtina
Zdroj: Basic research in cardiology [Basic Res Cardiol] 2021 Apr 13; Vol. 116 (1), pp. 25. Date of Electronic Publication: 2021 Apr 13.
DOI: 10.1007/s00395-021-00865-9
Abstrakt: We have previously shown that overexpression of SKI, an endogenous TGF-β 1 repressor, deactivates the pro-fibrotic myofibroblast phenotype in the heart. We now show that SKI also functions independently of SMAD/TGF-β signaling, by activating the Hippo tumor-suppressor pathway and inhibiting the Transcriptional co-Activator with PDZ-binding motif (TAZ or WWTR1). The mechanism(s) by which SKI targets TAZ to inhibit cardiac fibroblast activation and fibrogenesis remain undefined. A rat model of post-myocardial infarction was used to examine the expression of TAZ during acute fibrogenesis and chronic heart failure. Results were then corroborated with primary rat cardiac fibroblast cell culture performed both on plastic and on inert elastic substrates, along with the use of siRNA and adenoviral expression vectors for active forms of SKI, YAP, and TAZ. Gene expression was examined by qPCR and luciferase assays, while protein expression was examined by immunoblotting and fluorescence microscopy. Cell phenotype was further assessed by functional assays. Finally, to elucidate SKI's effects on Hippo signaling, the SKI and TAZ interactomes were captured in human cardiac fibroblasts using BioID2 and mass spectrometry. Potential interactors were investigated in vitro to reveal novel mechanisms of action for SKI. In vitro assays on elastic substrates revealed the ability of TAZ to overcome environmental stimuli and induce the activation of hypersynthetic cardiac myofibroblasts. Further cell-based assays demonstrated that SKI causes specific proteasomal degradation of TAZ, but not YAP, and shifts actin cytoskeleton dynamics to inhibit myofibroblast activation. These findings were supported by identifying the bi-phasic expression of TAZ in vivo during post-MI remodeling and fibrosis. BioID2-based interactomics in human cardiac fibroblasts suggest that SKI interacts with actin-modifying proteins and with LIM Domain-containing protein 1 (LIMD1), a negative regulator of Hippo signaling. Furthermore, we found that LATS2 interacts with TAZ, whereas LATS1 does not, and that LATS2 knockdown prevented TAZ downregulation with SKI overexpression. Our findings indicate that SKI's capacity to regulate cardiac fibroblast activation is mediated, in part, by Hippo signaling. We postulate that the interaction between SKI and TAZ in cardiac fibroblasts is arbitrated by LIMD1, an important intermediary in focal adhesion-associated signaling pathways. This study contributes to the understanding of the unique physiology of cardiac fibroblasts, and of the relationship between SKI expression and cell phenotype.
Databáze: MEDLINE
Externí odkaz: