BACKGROUND: Abdominal aortic aneurysm (AAA) is a catastrophic disease with little effective therapy, likely due to the limited understanding of the mechanisms underlying AAA development and progression. ATF3 (activating transcription factor 3) has been increasingly recognized as a key regulator of cardiovascular diseases. However, the role of ATF3 in AAA development and progression remains elusive. METHODS: Genome-wide RNA sequencing analysis was performed on the aorta isolated from saline or Ang II (angiotensin II)–induced AAA mice, and ATF3 was identified as the potential key gene for AAA development. To examine the role of ATF3 in AAA development, vascular smooth muscle cell–specific ATF3 knockdown or overexpressed mice by recombinant adeno-associated virus serotype 9 vectors carrying ATF3, or shRNA-ATF3 with SM22α (smooth muscle protein 22-α) promoter were used in Ang II–induced AAA mice. In human and murine vascular smooth muscle cells, gain or loss of function experiments were performed to investigate the role of ATF3 in vascular smooth muscle cell proliferation and apoptosis. RESULTS: In both Ang II–induced AAA mice and patients with AAA, the expression of ATF3 was reduced in aneurysm tissues but increased in aortic lesion tissues. The deficiency of ATF3 in vascular smooth muscle cell promoted AAA formation in Ang II–induced AAA mice. PDGFRB (platelet-derived growth factor receptor β) was identified as the target of ATF3, which mediated vascular smooth muscle cell proliferation in response to TNF-alpha (tumor necrosis factor-α) at the early stage of AAA. ATF3 suppressed the mitochondria-dependent apoptosis at the advanced stage by upregulating its direct target BCL2. Our chromatin immunoprecipitation results also demonstrated that the recruitment of NFκB1 and P300/BAF/H3K27ac complex to the ATF3 promoter induces ATF3 transcription via enhancer activation. NFKB1 inhibitor (andrographolide) inhibits the expression of ATF3 by blocking the recruiters NFKB1 and ATF3-enhancer to the ATF3-promoter region, ultimately leading to AAA development. CONCLUSIONS: Our results demonstrate a previously unrecognized role of ATF3 in AAA development and progression, and ATF3 may serve as a novel therapeutic and prognostic marker for AAA.

Purpose: With the continuous development of Internet technology, virtual brand communities (VBCs) have increasingly become essential fronts for enterprises and consumers to carry out professional communication and the leading platform for consumers and other consumers to engage in social and brand discussion. Meanwhile, numerous scholars began to pay attention to VBCs as their research topic. However, there is no systematic understanding of the existing literature on the VBCs research. Therefore, this study aims to provide a comprehensive and systematic review of VBCs research over the past twenty years.Design/methodology/approach: Based on HistCite and CiteSpace software, descriptive statistics and bibliometric analysis were conducted in this study. Specifically, by adopting research cooperation network analysis, co-citation analysis of literature, cluster analysis and co-word analysis, the authors analyzed 1,157 articles on VBCs in the Web of Science database from 2000 to 2020.Findings: This study summarizes the research of VBCs from three aspects. First, the general characteristics of VBCs literature are analyzed. Second, knowledge bases, research contents, theoretical foundations and theoretical contributions of VBCs are dug and integrated into a knowledge framework. Third, the evolution and trend of VBCs research topics are visualized and analyzed in two phases (from 2005 to 2012 and from 2013 to 2020).Originality/value: This study describes the research status, knowledge structure and famous topics of VBCs research over the past twenty years. Further, the research topics for VBCs have maintained continuity in the last twenty years. Furthermore, the research topics have also been evolving with the development of network technology and changes in the external environment. These results also provide valuable clues about this field's future directions and practical implications.

PIEZO channels are critical for sensory mechanotransduction. While MyoD-family inhibitor proteins were identified as PIEZO1 auxiliary subunits, their broader regulatory roles, particularly in sensory cells, remained unclear. Here, we demonstrate native MDFIC and MDFI regulate endogenous PIEZO channel currents in various nonsensory cell types. However, neither MDFIC nor MDFI are expressed in primary sensory neurons. In these cell types, we identified an uncharacterized third member of this family, Mdfic2 / Gm765 , that shares the ability to physically bind to PIEZO1 and PIEZO2. MDFIC2 is selectively expressed in subsets of mechanosensitive neurons, including dorsal root ganglia, trigeminal ganglia, and vagal sensory neurons. Like its paralogues, MDFIC2 alters PIEZO1/2 mechanosensitivity and inactivation kinetics, converting them into high-threshold slowly inactivating mechanoreceptors. Extensive cryo-EM reveals a conserved binding pocket for these auxiliary subunits in the pore modules of both PIEZO1 and PIEZO2 mediated by the posttranslationally modified distal C termini of MyoD-family inhibitor proteins. This structural and functional characterization of MyoD-family inhibitor proteins as PIEZO1/2 channel auxiliary subunits offers insights into the mechanobiology of nonsensory and sensory cells.

PIEZO channels are critical for sensory mechanotransduction. While MyoD-family inhibitor proteins were identified as PIEZO1 auxiliary subunits, their broader regulatory roles, particularly in sensory cells, remained unclear. Here we demonstrate native MDFIC and MDFI regulate endogenous PIEZO channel currents in various non-sensory cell types. However, neither MDFIC nor MDFI are expressed in primary sensory neurons. In these cell types we identified an uncharacterised member of this family, Mdfic2 / Gm765 , that shares the ability to physically bind to PIEZO1 and PIEZO2. MDFIC2 is selectively expressed in subsets of mechanosensitive neurons, including dorsal root ganglia, trigeminal ganglia, and vagal sensory neurons. Like its paralogues, MDFIC2 alters PIEZO1/2 mechanosensitivity and inactivation kinetics, converting them into high-threshold slowly inactivating mechanoreceptors. Extensive cryo-EM reveals a conserved binding pocket for these auxiliary subunits in the pore modules of both PIEZO1 and PIEZO2 mediated by the post-translationally modified distal C-termini of MyoD-family inhibitor proteins. This provides a comprehensive structural and functional characterisation of MyoD-family inhibitor proteins as PIEZO1/2 channel regulators and offers new insights into sensory physiology and mechanical pain mechanisms.