Apoptosis repressor with caspase recruitment domain promotes cell proliferation and phenotypic modulation through 14-3-3ε/YAP signaling in vascular smooth muscle cells

IRE1α: from the function to the potential therapeutic target in atherosclerosis

Inositol requiring enzyme 1 (IRE1) is generally thought to control the most conserved pathway in the unfolded protein response (UPR). Two isoforms of IRE1, IRE1α and IRE1β, have been reported in mammals. IRE1α is a ubiquitously expressed protein whose knockout shows marked lethality. In contrast, the expression of IRE1β is exclusively restricted in the epithelial cells of the respiratory and gastrointestinal tracts, and IRE1β-knockout mice are phenotypically normal. As research continues to deepen, IRE1α was showed to be tightly linked to inflammation, lipid metabolism regulation, cell death and so on. Growing evidence also suggests an important role for IRE1α in promoting atherosclerosis (AS) progression and acute cardiovascular events through disrupting lipid metabolism balance, facilitating cells apoptosis, accelerating inflammatory responses and promoting foam cell formation. In addition, IRE1α was recognized as novel potential therapeutic target in AS prevention. This review provides some clues about the relationship between IRE1α and AS, hoping to contribute to further understanding roles of IRE1α in atherogenesis and to be helpful for the design of novel efficacious therapeutics agents targeting IRE1α-related pathways.

14-3-3ε: a protein with complex physiology function but promising therapeutic potential in cancer

Over the past decade, the role of the 14-3-3 protein has received increasing interest. Seven subtypes of 14-3-3 proteins exhibit high homology; however, each subtype maintains its specificity. The 14-3-3ε protein is involved in various physiological processes, including signal transduction, cell proliferation, apoptosis, autophagy, cell cycle regulation, repolarization of cardiac action, cardiac development, intracellular electrolyte homeostasis, neurodevelopment, and innate immunity. It also plays a significant role in the development and progression of various diseases, such as cardiovascular diseases, inflammatory diseases, neurodegenerative disorders, and cancer. These immense and various involvements of 14-3-3ε in diverse processes makes it a promising target for drug development. Although extensive research has been conducted on 14-3-3 dimers, studies on 14-3-3 monomers are limited. This review aimed to provide an overview of recent reports on the molecular mechanisms involved in the regulation of binding partners by 14-3-3ε, focusing on issues that could help advance the frontiers of this field. Video Abstract.

A double-edged sword: role of apoptosis repressor with caspase recruitment domain (ARC) in tumorigenesis and ischaemia/reperfusion (I/R) injury

Apoptosis repressor with caspase recruitment domain (ARC) acts as a potent and multifunctional inhibitor of apoptosis, which is mainly expressed in postmitotic cells, including cardiomyocytes. ARC is special for its N-terminal caspase recruitment domain and caspase recruitment domain. Due to the powerful inhibition of apoptosis, ARC is mainly reported to act as a cardioprotective factor during ischaemia‒reperfusion (I/R) injury, preventing cardiomyocytes from being devastated by various catastrophes, including oxidative stress, calcium overload, and mitochondrial dysfunction in the circulatory system. However, recent studies have found that ARC also plays a potential regulatory role in tumorigenesis especially in colorectal cancer and renal cell carcinomas, through multiple apoptosis-associated pathways, which remains to be explored in further studies. Therefore, ARC regulates the body and maintains the balance of physiological activities with its interesting duplex. This review summarizes the current research progress of ARC in the field of tumorigenesis and ischaemia/reperfusion injury, to provide overall research status and new possibilities for researchers.

Neutrophil extracellular traps induce abdominal aortic aneurysm formation by promoting the synthetic and proinflammatory smooth muscle cell phenotype via Hippo-YAP pathway

The neutrophil plays an important role during abdominal aortic aneurysm (AAA) formation by undergoing histone citrullination with peptidyl arginine deiminase 4 (encoded by Padi4) and releasing neutrophil extracellular traps (NETs). However, the specific role of NETs during AAA formation is elusive. We found the levels of NET components in serum and tissues were found to be significantly associated with the clinical outcome of AAA patients. Furthermore, we reported that NETs induced the synthetic and proinflammatory smooth muscle cells (SMCs) phenotype and promoted AAA formation in a Hippo-YAP pathway-dependent manner by in vitro and in vivo experiments. Padi4 or Yap global knockout mice, exhibited significantly less synthetic and proinflammatory phenotypes of SMCs and developed AAA with lower frequency and severity compared with those of controls. Further studies indicated that the phenotypic switch of SMCs was associated with NETs-regulated enrichment status of H3K4me3 and H3K27me3 at promoters of synthetic and proinflammatory genes in SMCs. Cumulatively, these data suggest that NETs contribute to AAA formation by promoting the synthetic and proinflammatory phenotype of SMCs via inhibiting the Hippo-YAP pathway. A better understanding of the molecular mechanisms that regulate NETs and SMC phenotype is important to provide suitable cellular targets to prevent AAA.

Hippo: a new hub for atherosclerotic disease

Abstract:

Hippo,an evolutionarily conserved kinase cascade reaction in organisms,can respond to a set of signals,such as mechanical signals and cell metabolism,to maintain cell growth,differentiation,tissue/organ development and homeostasis.In the past ten years,HIPPO has controlled the development of tissues and organs by regulating the process of cell proliferation,especially in the field of cardiac regeneration after myocardial infarction.This suggests that HIPPO signaling is closely linked to cardiovascular disease.Atherosclerosis is the most common disease of the cardiovascular system. It is characterised by chronic inflammation of the vascular wall, mainly involving dysfunction of endothelial cells, smooth muscle cells and macrophages.Oxidized Low density lipoprotein (LDL) damages the barrier function of endothelial cells, which enter the middle membrane of the vascular wall, accelerates the formation of foam cells and promotes the occurrence and development of atherosclerosis.Autophagy is associated with the development of atherosclerosis.However, the mechanism of HIPPO regulation of atherosclerosis has not meant to clarified.In view of the pivotal role of this signaling pathway in maintaining cell growth,proliferation and differentiation,the imbalance of Hippo is related to atherosclerosis and related diseases.In this review,we emphasized Hippo as a hub for regulating atherosclerosis and discussed its potential targets in pathophysiology,human diseases,and related pharmacology.