c-Cbl Inhibition Improves Cardiac Function and Survival in Response to Myocardial Ischemia

Rafiq, Khadija; Kolpakov, Mikhail A.; Seqqat, Rachid; Guo, Jia; Guo, Xinji; Zhao, Qi; Yu, Daohai; Mohapatra, Bhopal; Zutshi, Neha; An, Wei; Band, Hamid; Sanjay, Archana; Houser, Steven R.; Sabri, Abdelkarim

doi:10.1161/circulationaha.113.007004

Cited by 46 publications

(27 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Myocardial infarction (MI) caused by coronary artery blockade is the major cause of death worldwide (Rafiq et al ., ). The continuous inflammatory response and necrosis of ischaemic tissue are two of the most marked characteristics that could mutually enhance during the process of MI‐induced heart damage and eventually lead to heart failure (Jones et al ., ).…”

Section: Introductionmentioning

confidence: 97%

Toll‐interacting protein contributes to mortality following myocardial infarction through promoting inflammation and apoptosis

Wan

Liu

Zhang

et al. 2015

British J Pharmacology

View full text Add to dashboard Cite

BACKGROUND AND PURPOSEToll-interacting protein (Tollip) is an endogenous inhibitor of toll-like receptors, a superfamily that plays a pivotal role in various pathological conditions, including myocardial infarction (MI). However, the exact role of Tollip in MI remains unknown. EXPERIMENTAL APPROACHMI models were established in Tollip knockout (KO) mice, mice with cardiac-specific overexpression of human Tollip gene and in their Tollip +/+ and non-transgenic controls respectively. The effects of Tollip on MI were evaluated by mortality, infarct size and cardiac function. Hypoxia-induced cardiomyocyte damage was investigated in vitro to confirm the role of Tollip in heart damage. KEY RESULTSTollip expression was dramatically up-regulated in human ischaemic hearts and infarcted mice hearts. MI-induced mortality, infarct size and cardiac dysfunction were decreased in Tollip-KO mice compared with Tollip +/+ controls. Ischaemic hearts from Tollip-KO mice exhibited decreased inflammatory cell infiltration and reduced NF-κB activation. Tollip depletion also alleviated myocardial apoptosis by down-regulating pro-apoptotic protein levels and up-regulating anti-apoptotic protein expressions in infarct border zone. Conversely, MI effects were exacerbated in mice with cardiac-specific Tollip overexpression. This aggravated MI injury by Tollip in vivo was confirmed with in vitro assays. Inhibition of Akt signalling was associated with the detrimental effects of Tollip on MI injury; activation of Akt largely reversed the deleterious effects of Tollip on MI-induced cardiomyocyte death. CONCLUSIONS AND IMPLICATIONSTollip promotes inflammatory and apoptotic responses after MI, leading to increased mortality and aggravated cardiac dysfunction. These findings suggest that Tollip may serve as a novel therapeutic target for the treatment of MI.

show abstract

Section: Introductionmentioning

confidence: 97%

Toll‐interacting protein contributes to mortality following myocardial infarction through promoting inflammation and apoptosis

Wan

Liu

Zhang

et al. 2015

British J Pharmacology

View full text Add to dashboard Cite

show abstract

“…These data show that concurrent CBL and CBL-B deletion during T-cell development using CD4-Cre largely recapitulates the T-cell activation and systemic immune cell infiltration phenotype previously described, providing direct support that the new CBL-B-flox model and its combination with the existing CBL-flox model will allow controlled, tissue-specific deletion of CBL and/or CBL-B in specific cell types. Importantly, the newly-validated floxed models will allow, for the first time, a dissection of the specific as well as redundant roles of CBL and CBL-B to fully explore their roles in adult mammalian tissue function and pathology without the inherent developmental issues associated with the whole body CBL KO mice [76–78], immune hyperactivity of CBL-B-null mice [19], and importantly eliminate the issue of embryonic lethality of germline double KO mice. Importantly, this model will allow concurrent CBL and CBL-B deletion in non-hematopoietic tissues to understand the role of these proteins in physiology and tumorigenesis, without spontaneous tumor rejection.…”

Section: Discussionmentioning

confidence: 99%

A novelCBL-Bflox/floxmouse model allows tissue-selective fully conditionalCBL/CBL-Bdouble-knockout: CD4-Cre mediatedCBL/CBL-Bdeletion occurs in both T-cells and hematopoietic stem cells

Goetz

Mohapatra

et al. 2016

Oncotarget

Self Cite

View full text Add to dashboard Cite

CBL-family ubiquitin ligases are critical negative regulators of tyrosine kinase signaling, with a clear redundancy between CBL and CBL-B evident in the immune cell and hematopoietic stem cell studies. Since CBL and CBL-B are negative regulators of immune cell activation, elimination of their function to boost immune cell activities could be beneficial in tumor immunotherapy. However, mutations of CBL are associated with human leukemias, pointing to tumor suppressor roles of CBL proteins; hence, it is critical to assess the tumor-intrinsic roles of CBL and CBL-B in cancers. This has not been possible since the only available whole-body CBL-B knockout mice exhibit constitutive tumor rejection. We engineered a new CBL-Bflox/flox mouse, combined this with an existing CBLflox/flox mouse to generate CBLflox/flox; CBL-Bflox/flox mice, and tested the tissue-specific concurrent deletion of CBL and CBL-B using the widely-used CD4-Cre transgenic allele to produce a T-cell-specific double knockout. Altered T-cell development, constitutive peripheral T-cell activation, and a lethal multi-organ immune infiltration phenotype largely resembling the previous Lck-Cre driven floxed-CBL deletion on a CBL-B knockout background establish the usefulness of the new model for tissue-specific CBL/CBL-B deletion. Unexpectedly, CD4-Cre-induced deletion in a small fraction of hematopoietic stem cells led to expansion of certain non-T-cell lineages, suggesting caution in the use of CD4-Cre for T-cell-restricted gene deletion. The establishment of a new model of concurrent tissue-selective CBL/CBL-B deletion should allow a clear assessment of the tumor-intrinsic roles of CBL/CBL-B in non-myeloid malignancies and help test the potential for CBL/CBL-B inactivation in immunotherapy of tumors.

show abstract

“…C57BL/6-derived Csk AS mice are hemizygous for the Csk AS BAC transgene on a Csk −/− background, as described previously (20, 26). Due to sterility of c-Cbl −/− male mice, we were not able to produce a sustained lineage of Csk AS Cbl −/− mice, but we obtained three individuals by crossing c-Cbl −/− female mice from E. Peterson (University of Minnesota) (72) with Csk +/− (26) and Csk AS male mice from our colony and then crossing Cbl +/− Csk +/− with Cbl +/− Csk AS mice. All mice were housed in specific pathogen-free conditions and genotyped using real-time PCR (Transnetyx, Inc., Memphis, TN).…”

Section: Methodsmentioning

confidence: 99%

An orthogonal c-Cbl recognition mode targets LynA for rapid degradation and builds specificity into the LynA checkpoint

Brian

Nunez

Schwertfeger

et al. 2019

Preprint

View full text Add to dashboard Cite

11The activity of Src-family kinases (SFKs), which phosphorylate immunoreceptor tyrosine-based 12 activation motifs (ITAMs), is critical factor regulating myeloid-cell activation. In a previous paper 13 (Freedman et al., 2015) we showed in macrophages that the SFK LynA is uniquely susceptible to rapid 14 ubiquitin-mediated degradation, functioning as a rheostat regulating ITAM signaling. We now report the 15 mechanism by which LynA is preferentially targeted for degradation and how cell specificity is built into 16 the LynA rheostat. Using genetic and biochemical analysis, we found that the E3 ubiquitin ligase c-Cbl 17 preferentially targets LynA via tyrosine 32 in its unique insert region. This orthogonal mode of c-Cbl 18 recognition depresses the steady-state level of macrophage LynA. Mast cells, however, express little c- 19Cbl and have correspondingly high steady-state levels of LynA. Upon activation, mast-cell LynA is not 20 rapidly degraded, and SFK-mediated signaling is amplified relative to macrophages. Cell-specific c-Cbl 21 expression therefore builds cell specificity into the LynA checkpoint. 2245 macrophage activation (20). The mechanism preferentially targeting LynA for polyubiquitination and the 46 molecular basis of this selectivity have not been elucidated previously. 47Unlike Dectin-1 and FcγR signaling in macrophages, which is typically triggered in the context of 48 pathogen-induced µm-scale clusters of receptors (5, 9, 20), mast-cell FcεR signaling has a low 49 threshold for activation--small or even monovalent antigen-IgE complexes are sufficient to induce a 50 signaling response (21, 22). Like macrophages, mast cells express LynA, and this disparity in receptor 51 sensitivity has not previously been explained. This paper describes the mechanism by which active LynA is selectively recognized and rapidly 53 degraded, tuning its activation kinetics and its steady-state protein levels in a cell-specific manner. To 54 reveal the requirements for LynA degradation, we synchronized receptor-independent SFK activation 55 using the designer inhibitor 3-IB-PP1 (23-25), which specifically inhibits a variant of the SFK-inhibitory 56 kinase Csk (Csk AS ) (20, 25, 26). Csk is responsible for phosphorylating a key inhibitory tyrosine in the 57 C-terminus of all the SFKs. Inhibiting Csk AS leads to rapid and robust SFK activation due to the loss of 58 the dynamic equilibrium between Csk and the phosphatases CD45 and CD148 (27, 28). We showed 59 previously that SFK activation induced via 3-IB-PP1 treatment leads to the phosphorylation of the E3 60 ubiquitin ligase c-Cbl and the preferential polyubiquitination and degradation of the SFK LynA, but it 61 was not clear whether these two events were linked. Using knockdown, overexpression, and genetic 62 models, we now demonstrate that c-Cbl, but not its homolog Cbl-b, controls the steady-state expression 63 of LynA and mediates its rapid degradation upon activation in macrophages. LynA is targeted by c-Cbl 64 via a phosphorylation site, Tyr32 within its unique r...

show abstract

c-Cbl Inhibition Improves Cardiac Function and Survival in Response to Myocardial Ischemia

Cited by 46 publications

References 43 publications

Toll‐interacting protein contributes to mortality following myocardial infarction through promoting inflammation and apoptosis

Toll‐interacting protein contributes to mortality following myocardial infarction through promoting inflammation and apoptosis

A novelCBL-Bflox/floxmouse model allows tissue-selective fully conditionalCBL/CBL-Bdouble-knockout: CD4-Cre mediatedCBL/CBL-Bdeletion occurs in both T-cells and hematopoietic stem cells

An orthogonal c-Cbl recognition mode targets LynA for rapid degradation and builds specificity into the LynA checkpoint

Contact Info

Product

Resources

About