Cezanne is a critical regulator of pathological arterial remodelling by targeting β-catenin signalling

JOSD2 mediates isoprenaline-induced heart failure by deubiquitinating CaMKIIδ in cardiomyocytes

Prolonged stimulation of β-adrenergic receptor (β-AR) can lead to sympathetic overactivity that causes pathologic cardiac hypertrophy and fibrosis, ultimately resulting in heart failure. Recent studies suggest that abnormal protein ubiquitylation may contribute to the pathogenesis of cardiac hypertrophy and remodeling. In this study, we demonstrated that deficiency of a deubiquitinase, Josephin domain-containing protein 2 (JOSD2), ameliorated isoprenaline (ISO)- and myocardial infarction (MI)-induced cardiac hypertrophy, fibrosis, and dysfunction both in vitro and in vivo. Conversely, JOSD2 overexpression aggravated ISO-induced cardiac pathology. Through comprehensive mass spectrometry analysis, we identified that JOSD2 interacts with Calcium-calmodulin-dependent protein kinase II (CaMKIIδ). JOSD2 directly hydrolyzes the K63-linked polyubiquitin chains on CaMKIIδ, thereby increasing the phosphorylation of CaMKIIδ and resulting in calcium mishandling, hypertrophy, and fibrosis in cardiomyocytes. In vivo experiments showed that the cardiac remodeling induced by JOSD2 overexpression could be reversed by the CaMKIIδ inhibitor KN-93. In conclusion, our study highlights the role of JOSD2 in mediating ISO-induced cardiac remodeling through the regulation of CaMKIIδ ubiquitination, and suggests its potential as a therapeutic target for combating the disease. Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary. All have been checked.

Nuclear receptor subfamily 1 group D member 1 suppresses the proliferation, migration of adventitial fibroblasts, and vascular intimal hyperplasia via mammalian target of rapamycin complex 1/β-catenin pathway

BACKGROUND

In-stent restenosis hardly limits the therapeutic effect of the percutaneous vascular intervention. Although the restenosis is significantly ameliorated after the application of new drug-eluting stents, the incidence of restenosis remains at a high level.

OBJECTIVE

Vascular adventitial fibroblasts (AFs) play an important role in intimal hyperplasia and subsequent restenosis. The current study was aimed to investigate the role of nuclear receptor subfamily 1, group D, member 1 (NR1D1) in the vascular intimal hyperplasia.

METHODS AND RESULTS

We observed increased expression of NR1D1 after the transduction of adenovirus carrying Nr1d1 gene (Ad-Nr1d1) in AFs. Ad-Nr1d1 transduction significantly reduced the numbers of total AFs, Ki-67-positive AFs, and the migration rate of AFs. NR1D1 overexpression decreased the expression level of β-catenin and attenuated the phosphorylation of the effectors of mammalian target of rapamycin complex 1 (mTORC1), including mammalian target of rapamycin (mTOR) and 4E binding protein 1 (4EBP1). Restoration of β-catenin by SKL2001 abolished the inhibitory effects of NR1D1 overexpression on the proliferation and migration of AFs. Surprisingly, the restoration of mTORC1 activity by insulin could also reverse the decreased expression of β-catenin, attenuated proliferation, and migration in AFs induced by NR1D1 overexpression. In vivo, we found that SR9009 (an agonist of NR1D1) ameliorated the intimal hyperplasia at days 28 after injury of carotid artery. We further observed that SR9009 attenuated the increased Ki-67-positive AFs, an essential part of vascular restenosis at days 7 after injury to the carotid artery.

CONCLUSION

These data suggest that NR1D1 inhibits intimal hyperplasia by suppressing the proliferation and migration of AFs in a mTORC1/β-catenin-dependent manner.

Causal Role for Neutrophil Elastase in Thoracic Aortic Dissection in Mice

BACKGROUND

Thoracic aortic dissection (TAD) is a life-threatening aortic disease without effective medical treatment. Increasing evidence has suggested a role for NE (neutrophil elastase) in vascular diseases. In this study, we aimed at investigating a causal role for NE in TAD and exploring the molecular mechanisms involved.

METHODS

β-aminopropionitrile monofumarate was administrated in mice to induce TAD. NE deficiency mice, pharmacological inhibitor GW311616A, and adeno-associated virus-2-mediated in vivo gene transfer were applied to explore a causal role for NE and associated target gene in TAD formation. Multiple functional assays and biochemical analyses were conducted to unravel the underlying cellular and molecular mechanisms of NE in TAD.

RESULTS

NE aortic gene expression and plasma activity was significantly increased during β-aminopropionitrile monofumarate-induced TAD and in patients with acute TAD. NE deficiency prevents β-aminopropionitrile monofumarate-induced TAD onset/development, and GW311616A administration ameliorated TAD formation/progression. Decreased levels of neutrophil extracellular traps, inflammatory cells, and MMP (matrix metalloproteinase)-2/9 were observed in NE-deficient mice. TBL1x (F-box-like/WD repeat-containing protein TBL1x) has been identified as a novel substrate and functional downstream target of NE in TAD. Loss-of-function studies revealed that NE mediated inflammatory cell transendothelial migration by modulating TBL1x-LTA4H (leukotriene A4 hydrolase) signaling and that NE regulated smooth muscle cell phenotype modulation under TAD pathological condition by regulating TBL1x-MECP2 (methyl CpG-binding protein 2) signal axis. Further mechanistic studies showed that TBL1x inhibition decreased the binding of TBL1x and HDAC3 (histone deacetylase 3) to MECP2 and LTA4H gene promoters, respectively. Finally, adeno-associated virus-2-mediated Tbl1x gene knockdown in aortic smooth muscle cells confirmed a regulatory role for TBL1x in NE-mediated TAD formation.

CONCLUSIONS

We unravel a critical role of NE and its target TBL1x in regulating inflammatory cell migration and smooth muscle cell phenotype modulation in the context of TAD. Our findings suggest that the NE-TBL1x signal axis represents a valuable therapeutic for treating high-risk TAD patients.

OTUD7B Activates Wnt Signaling Pathway through the Interaction with LEF1

The Wnt signaling pathway plays a critical role in regulating normal cellular processes, including proliferation, differentiation, and apoptosis. Dysregulation of Wnt signaling has been implicated in various human diseases, including cancer. β-catenin and LEF1 are key mediators of Wnt signaling, and their dysregulation is a hallmark of many cancer types. In this study, we aimed to identify the deubiquitinases (DUBs) that regulate the Wnt signaling pathway through the essential component LEF1. Screening candidate DUBs from the human DUB library, we discovered that OTUD7B interacts with LEF1 and activates Wnt signaling. OTUD7B and LEF1 interact with each other through the UBA and HMG domains, respectively. Furthermore, OTUD7B promotes the nuclear localization of LEF1, leading to an increased interaction with β-catenin in the nucleus while not noticeably affecting ubiquitination on LEF1. Using qPCR array analysis, we found that OTUD7B overexpression leads to an upregulation of 75% of the tested Wnt target genes compared to the control. These findings suggest that OTUD7B may serve as a potential therapeutic target in human diseases, including cancers where Wnt signaling is frequently dysregulated.

Clinical implications of inflammation in atheroma formation and novel therapies in cardiovascular diseases

Cardiovascular diseases (CVD) are the leading causes of death and disability in the world. Among all CVD, the most common is coronary artery disease (CAD). CAD results from the complications promoted by atherosclerosis, which is characterized by the accumulation of atherosclerotic plaques that limit and block the blood flow of the arteries involved in heart oxygenation. Atherosclerotic disease is usually treated by stents implantation and angioplasty, but these surgical interventions also favour thrombosis and restenosis which often lead to device failure. Hence, efficient and long-lasting therapeutic options that are easily accessible to patients are in high demand. Advanced technologies including nanotechnology or vascular tissue engineering may provide promising solutions for CVD. Moreover, advances in the understanding of the biological processes underlying atherosclerosis can lead to a significant improvement in the management of CVD and even to the development of novel efficient drugs. To note, over the last years, the observation that inflammation leads to atherosclerosis has gained interest providing a link between atheroma formation and oncogenesis. Here, we have focused on the description of the available therapy for atherosclerosis, including surgical treatment and experimental treatment, the mechanisms of atheroma formation, and possible novel therapeutic candidates such as the use of anti-inflammatory treatments to reduce CVD.

Ant-Neointimal Formation Effects of SLC6A6 in Preventing Vascular Smooth Muscle Cell Proliferation and Migration via Wnt/β-Catenin Signaling

Vascular smooth muscle cells (VSMCs) play an important role in the pathogenesis of vascular remolding, such as atherosclerosis and restenosis. Solute carrier family 6 member 6 (SLC6A6) is a transmembrane transporter that maintains a variety of physiological functions and is highly expressed in VSMCs. However, its role on VSMCs during neointimal formation remains unknown. In this study, mRNA and protein levels of SLC6A6 were examined using models of VSMC phenotype switching in vivo and in vitro and human artery samples with or without atherosclerosis. SLC6A6 gain- and loss-of-function approaches were performed by adenovirus infection or small interfering RNA (siRNA) transfection, respectively. Reactive oxygen species (ROS), proliferation, migration, and phenotype-related proteins of VSMCs were measured. Vascular stenosis rate and related genes were assessed in a rat vascular balloon injury model overexpressing SLC6A6. SLC6A6 was downregulated in dedifferentiated VSMCs, atherosclerotic vascular tissues, and injured vascular tissues. SLC6A6 suppressed VSMC proliferation and migration, while increasing contractile VSMC proteins. Mechanistically, SLC6A6 overexpression reduced ROS production and inhibited the Wnt/β-catenin pathway. Furthermore, SLC6A6 overexpression suppressed neointimal formation in vivo. Collectively, overexpression of SLC6A6 suppresses neointimal formation by inhibiting VSMC proliferation and migration via Wnt/β-catenin signaling and maintaining the VSMC contractile phenotype.

Protective role of cezanne in doxorubicin-induced cardiotoxicity by inhibiting autophagy, apoptosis and oxidative stress

Doxorubicin (DOX) is frequently used in clinical practice for its broad-spectrum effects. However, its benefit is limited by a series of complications, including excessive apoptosis and autophagy of cardiomyocytes, overproduction of reactive oxygen species (ROS) and high level of oxidative stress. As a new protein, OTU domain-containing 7B (OTUD7B), also called Cezanne, has been reported to regulate many pathological processes. However, whether it plays a role in DOX-induced cardiotoxicity is still unclear. We discovered that the Cezanne level was significantly increased in DOX-treated neonatal rat cardiomyocytes (NRCMs) and C57BL/6 J mice hearts. In vitro, the knockdown of Cezanne with adenovirus in NRCMs significantly worsened DOX-induced apoptosis, autophagy and oxidative stress, while Cezanne overexpression showed opposite results. In vivo, the overexpression of Cezanne using cardiomyocyte-targeted adeno-associated virus 9 (AAV9) significantly reduced cardiomyocyte apoptosis, autophagy and oxidative stress level when C57BL/6 J mice were subjected to DOX. Mechanistically, the overexpression of Cezanne significantly reversed the in-activation of the PI3K/AKT/mTOR pathway induced by DOX, while the inhibitors of this pathway abolished the effect of Cezanne, suggesting that the PI3K/AKT/mTOR pathway plays a role in the protective function of Cezanne. These findings indicate that Cezanne could ameliorate DOX-induced cardiotoxicity by attenuating the apoptosis and autophagy of cardiomyocytes and decreasing the level of oxidative stress.

Targeted Inhibition of Matrix Metalloproteinase-8 Prevents Aortic Dissection in a Murine Model

Aortic dissection (AD) is a lethal aortic pathology without effective medical treatments since the underlying pathological mechanisms responsible for AD remain elusive. Matrix metalloproteinase-8 (MMP8) has been previously identified as a key player in atherosclerosis and arterial remodeling. However, the functional role of MMP8 in AD remains largely unknown. Here, we report that an increased level of MMP8 was observed in 3-aminopropionitrile fumarate (BAPN)-induced murine AD. AD incidence and aortic elastin fragmentation were markedly reduced in MMP8-knockout mice. Importantly, pharmacologic inhibition of MMP8 significantly reduced the AD incidence and aortic elastin fragmentation. We observed less inflammatory cell accumulation, a lower level of aortic inflammation, and decreased smooth muscle cell (SMC) apoptosis in MMP8-knockout mice. In line with our previous observation that MMP8 cleaves Ang I to generate Ang II, BAPN-treated MMP8-knockout mice had increased levels of Ang I, but decreased levels of Ang II and lower blood pressure. Additionally, we observed a decreased expression level of vascular cell adhesion molecule-1 (VCAM1) and a reduced level of reactive oxygen species (ROS) in MMP8-knockout aortas. Mechanistically, our data show that the Ang II/VCAM1 signal axis is responsible for MMP8-mediated inflammatory cell invasion and transendothelial migration, while MMP8-mediated SMC inflammation and apoptosis are attributed to Ang II/ROS signaling. Finally, we observed higher levels of aortic and serum MMP8 in patients with AD. We therefore provide new insights into the molecular mechanisms underlying AD and identify MMP8 as a potential therapeutic target for this life-threatening aortic disease.

Inhibition of VRK1 suppresses proliferation and migration of vascular smooth muscle cells and intima hyperplasia after injury via mTORC1/β-catenin axis

Characterized by abnormal proliferation and migration of vascular smooth muscle cells (VSMCs), neointima hyperplasia is a hallmark of vascular restenosis after percutaneous vascular interventions. Vaccinia-related kinase 1 (VRK1) is a stress adaption-associated ser/thr protein kinase that can induce the proliferation of various types of cells. However, the role of VRK1 in the proliferation and migration of VSMCs and neointima hyperplasia after vascular injury remains unknown. We observed increased expression of VRK1 in VSMCs subjected to platelet-derived growth factor (PDGF)-BB by western blotting. Silencing VRK1 by shVrk1 reduced the number of Ki-67-positive VSMCs and attenuated the migration of VSMCs. Mechanistically, we found that relative expression levels of β-catenin and effectors of mTOR complex 1 (mTORC1) such as phospho (p)-mammalian target of rapamycin (mTOR), p-S6, and p-4EBP1 were decreased after silencing VRK1. Restoration of β-catenin expression by SKL2001 and re-activation of mTORC1 by Tuberous sclerosis 1 siRNA (siTsc1) both abolished shVrk1-mediated inhibitory effect on VSMC proliferation and migration. siTsc1 also rescued the reduced expression of β-catenin caused by VRK1 inhibition. Furthermore, mTORC1 re-activation failed to recover the attenuated proliferation and migration of VSMC resulting from shVrk1 after silencing β-catenin. We also found that the vascular expression of VRK1 was increased after injury. VRK1 inactivation in vivo inhibited vascular injury-induced neointima hyperplasia in a β-catenindependent manner. These results demonstrate that inhibition of VRK1 can suppress the proliferation and migration of VSMC and neointima hyperplasia after vascular injury via mTORC1/β-catenin pathway.

Ferulic Acid Alleviates Atherosclerotic Plaques by Inhibiting VSMC Proliferation Through the NO/p21 Signaling pathway

The benefits and risks of inhibiting the proliferation and migration of vascular smooth muscle cells (VSMCs) in atherosclerosis (AS) remain a subject of debate. In this study, we investigated the effect of ferulic acid (FA) on the proliferation and migration of VSMCs induced by platelet-derived growth factor (PDGF) and the associated mechanism and used ApoE^-/- mice to study whether the effect of FA on VSMC proliferation and migration is beneficial in alleviating AS plaques. It was found that FA not only reduced blood lipid levels but also promoted the production of nitric oxide (NO) by MOVAS cells through the endothelial nitric oxide synthase (eNOS) pathway, inhibited the migration and proliferation of VSMCs induced by PDGF, promoted the expression of p21 in VSMCs, and exerted a therapeutic effect against AS.