Aim Apoptosis of vascular smooth muscle cells (VSMCs) influenced by abnormal cyclic stretch is crucial for vascular remodelling during hypertension. Lamin A/C, a nuclear envelope protein, is mechano‐responsive, but the role of lamin A/C in VSMC apoptosis is still unclear. Methods FX‐5000T Strain Unit provided cyclic stretch (CS) in vitro. AnnexinV/PI and cleaved Caspase 3 ELISA detected apoptosis. qPCR was used to investigate the expression of miR‐124‐3p and a luciferase reporter assay was used to evaluate the ability of miR‐124‐3p binding to the Lmna 3’UTR. Protein changes of lamin A/C and relevant molecules were detected using western blot. Ingenuity Pathway Analysis and Protein/DNA array detected the potential transcription factors. Renal hypertensive rats verified these changes. Results High cyclic stretch (15%‐CS) induced VSMC apoptosis and repressed lamin A/C expressions compared with normal (5%‐CS) control. Downregulation of lamin A/C enhanced VSMC apoptosis. In addition, 15%‐CS had no significant effect on mRNA expression of Lmna, and lamin A/C degradation was not induced by autophagy. 15%‐CS elevated miR‐124‐3p bound to the 3’UTR of Lmna and negatively regulated protein expression of lamin A/C. Similar changes occurred in renal hypertensive rats compared with sham controls. Lamin A/C repression affected activity of TP53, CREB1, MYC, STAT1/5/6 and JUN, which may in turn affect apoptosis. Conclusion Our data suggested that the decreased expression of lamin A/C upon abnormal cyclic stretch and hypertension may induce VSMC apoptosis. These mechano‐responsive factors play important roles in VSMC apoptosis and might be novel therapeutic targets for vascular remodelling in hypertension.

Dendritic cells (DCs) have crucial roles in immune‐related diseases. However, it is difficult to explore DCs because of their rareness and heterogeneity. Although previous studies had been performed to detect the phenotypic characteristics of DC populations, the functional diversity has been ignored. Using a combination of flow cytometry, single‐cell quantitative PCR, and bioinformatic analysis, we depicted the DC panorama with not only phenotypic but also functional markers. Functional classification of DCs in mouse lymphoid tissue (spleen) and nonlymphoid tissue (liver) was performed. The results revealed that expression of macrophage scavenger receptor 1 (MSR1) and C–C motif chemokine receptors (CCR)1, CCR2, and CCR4 were elevated in liver DCs, suggesting increased lipid uptake and migration abilities. The enriched expression of costimulatory molecule CD80, TLR9, and TLR adaptor MYD88 in spleen DCs indicated a more‐mature phenotype, enhanced pathogen recognition, and T‐cell stimulation abilities. Furthermore, we compared DCs in the atherosclerotic mouse models with healthy controls. In addition to the quantitative increase in DCs in the liver and spleen of the apolipoprotein E‐knockout (ApoE−/−) mice, the functional expression patterns of the DCs also changed at the single‐cell level. These results promote our understanding of the participation of DCs in inflammatory diseases and have potential applications in DC clinical assessment.—Shi, Q., Zhuang, F., Liu, J.‐T., Li, N., Chen, Y.‐X., Su, X.‐B., Yao, A.‐H., Yao, Q.‐P., Han, Y., Li, S.‐S., Qi, Y.‐X., Jiang, Z.‐L. Single‐cell analyses reveal functional classification of dendritic cells and their potential roles in inflammatory disease. FASEB J. 33, 3784–3794 (2019). www.fasebj.org

Endothelial cells (ECs) are located at the interface between flowing blood and the vessel wall, and abnormal EC proliferation induced by pathologic environments plays an important role in vascular remodeling in hypertensive conditions. Exchanges of information between blood components and ECs are important for EC function. Hence, the present study sought to determine how platelets induce EC dysfunction under hypertensive conditions. EC proliferation was increased in renal hypertensive rats established by abdominal aortic coarctation compared with control rats and that elevated thrombin in plasma promoted platelet activation, which may induce the release of platelet‐derived microparticles (PMPs). MicroRNA (MiR) array and qPCR revealed a higher level of miR‐142–3p in platelets and PMPs. In vitro, PMPs delivered miR‐142–3p into ECs and enhanced their proliferation via Bcl‐2‐associated transcription factor (BCLAF)1 and its downstream genes. These results indicate that PMPs deliver miR‐142–3p from activated platelets into ECs and that miR‐142–3p may play important roles in EC dysfunction in hypertensive conditions and may be a novel therapeutic target for maintaining EC homeostasis in hypertension.—Bao, H., Chen, Y.‐X., Huang, K., Zhuang, F., Bao, M., Han, Y., Chen, X.‐H., Shi, Q., Yao, Q.‐P., Qi, Y.‐X. Platelet‐derived microparticles promote endothelial cell proliferation in hypertension via miR‐142‐3p. FASEB J. 32, 3912–3923 (2018). www.fasebj.org

Vascular endothelial cells (ECs) and smooth muscle cells (VSMCs) are constantly exposed to hemodynamic forces in vivo, including flow shear stress and cyclic stretch caused by the blood flow. Numerous researches revealed that during various cardiovascular diseases such as atherosclerosis, hypertension, and vein graft, abnormal (pathological) mechanical forces play crucial roles in the dysfunction of ECs and VSMCs, which is the fundamental process during both vascular homeostasis and remodeling. Hemodynamic forces trigger several membrane molecules and structures, such as integrin, ion channel, primary cilia, etc., and induce the cascade reaction processes through complicated cellular signaling networks. Recent researches suggest that nuclear envelope proteins act as the functional homology of molecules on the membrane, are important mechanosensitive molecules which modulate chromatin location and gene transcription, and subsequently regulate cellular functions. However, the studies on the roles of nucleus in the mechanotransduction process are still at the beginning. Here, based on the recent researches, we focused on the nuclear envelope proteins and discussed the roles of pathological hemodynamic forces in vascular remodeling. It may provide new insight into understanding the molecular mechanism of vascular physiological homeostasis and pathophysiological remodeling and may help to develop hemodynamic-based strategies for the prevention and management of vascular diseases.

Background: Long noncoding RNAs (lncRNAs) are being discovered in multiple diseases at a rapid pace. However, the contribution of lncRNAs to hypertension remains largely unknown. In hypertension, the vascular walls are exposed to abnormal mechanical cyclic strain, which leads to vascular remodelling. Here, we investigated the mechanobiological role of lncRNAs in hypertension. Methods and results: Differences in the lncRNAs and mRNAs between spontaneously hypertensive rats and Wistar–Kyoto rats were screened using a gene microarray. The results showed that 68 lncRNAs and 255 mRNAs were upregulated in the aorta of spontaneously hypertensive rats, whereas 167 lncRNAs and 272 mRNAs were downregulated. Expressions of the screened lncRNAs, including XR007793, were validated by real-time PCR. A coexpression network was composed, and gene function was analysed using Ingenuity Pathway Analysis. In vitro, vascular smooth muscle cells (VSMCs) were subjected to cyclic strain at a magnitude of 5 (physiological normotensive cyclic strain) or 15% (pathological hypertensive cyclic strain) by Flexcell-4000T. A total of 15% cyclic strain increased XR007793 expression. XR007793 knockdown attenuated VSMC proliferation and migration and inhibited coexpressed genes such as signal transducers and activators of transcription 2 (stat2), LIM domain only 2 (lmo2) and interferon regulatory factor 7 (irf7). Conclusion: The profile of lncRNAs was varied in response to hypertension, and pathological elevated cyclic strain may play crucial roles during this process. Our data revealed a novel mechanoresponsive lncRNA-XR007793, which modulates VSMC proliferation and migration, and participates in vascular remodelling during hypertension.

Aims Mechanical factors play significant roles in neointimal hyperplasia after vein grafting, but the mechanisms are not fully understood. Here, we investigated the roles of microRNA-33 (miR-33) in neointimal hyperplasia induced by arterial mechanical stretch after vein grafting. Methods and results Grafted veins were generated by the ‘cuff’ technique. Neointimal hyperplasia and cell proliferation was significantly increased, and miR-33 expression was decreased after 1-, 2-, and 4-week grafts. In contrast, the expression of bone morphogenetic protein 3 (BMP3), which is a putative target of miR-33, and the phosphorylation of smad2 and smad5, which are potential downstream targets of BMP3, were increased in the grafted veins. miR-33 mimics/inhibitor and dual luciferase reporter assay confirmed the interaction of miR-33 and BMP3. miR-33 mimics attenuated, while miR-33 inhibitor accelerated, proliferation of venous smooth muscle cells (SMCs). Moreover, recombinant BMP3 increased SMC proliferation and P-smad2 and P-smad5 levels, whereas BMP3-directed siRNAs had the opposite effect. Then, venous SMCs were exposed to a 10%-1.25 Hz cyclic stretch (arterial stretch) by using the FX4000 cyclic stretch loading system in vitro to mimic arterial mechanical conditions. The arterial stretch increased venous SMC proliferation and repressed miR-33 expression, but enhanced BMP3 expression and smad2 and smad5 phosphorylation. Furthermore, perivascular multi-point injection in vivo demonstrated that agomiR-33 not only attenuates BMP3 expression and smad2 and smad5 phosphorylation, but also slows neointimal formation and cell proliferation in grafted veins. These effects of agomiR-33 on grafted veins could be reversed by local injection of BMP3 lentivirus. Conclusion The miR-33-BMP3-smad signalling pathway protects against venous SMC proliferation in response to the arterial stretch. miR-33 is a target that attenuates neointimal hyperplasia in grafted vessels and may have potential clinical applications.

Abnormal proliferation of endothelial cells (ECs) is important in vascular remodeling during hypertension, but the mechanisms are still unclear. In hypertensive rats caused by abdominal aortic coarctation, the expression of G-protein-coupled receptor kinase 6 (GRK6) in ECs at common carotid artery was repressed in vivo, and EC proliferation was increased. 15% cyclic stretch in vitro, which mimics the pathologically increased stretch in hypertension, repressed EC GRK6 expression via paracrine control by vascular smooth muscle cells (VSMCs). Furthermore, VSMC-derived microparticles (VSMC-MPs) were detected in the conditioned medium from VSMCs and in artery. VSMC-MPs from cells exposed to 15% cyclic stretch decreased GRK6 expression and increased EC proliferation. miR-27a was detected in VSMC-MPs and was upregulated by 15% cyclic stretch. miR-27a was transferred from VSMCs to ECs via VSMC-MPs and directly targeted on GRK6. Finally, a multi-point injection of antagomiR-27a around carotid artery decreased miR-27a expression in vivo, induced GRK6 expression, and reversed the abnormal EC proliferation. Pathologically elevated cyclic stretch increased the secretion of miR-27a, which was transferred from VSMCs to ECs via the VSMC-MPs, subsequently targeted GRK6, and induced EC proliferation. Locally decreasing miR-27a could be a novel therapeutic approach to attenuate the abnormal EC proliferation in hypertension.

Cyclic stretch is an important inducer of vascular smooth muscle cell (VSMC) proliferation, which is crucial in vascular remodeling during hypertension. However, the molecular mechanism remains unclear. We studied the effects of emerin and lamin A/C, two important nuclear envelope proteins, on VSMC proliferation in hypertension and the underlying mechano-mechanisms. In common carotid artery of hypertensive rats in vivo and in cultured cells subjected to high (15%) cyclic stretch in vitro, VSMC proliferation was increased significantly, and the expression of emerin and lamin A/C was repressed compared with normotensive or normal (5%) cyclic stretch controls. Using targeted siRNA to mimic the repressed expression of emerin or lamin A/C induced by 15% stretch, we found that VSMC proliferation was enhanced under static and 5%-stretch conditions. Overexpression of emerin or lamin A/C reversed VSMC proliferation induced by 15% stretch. Hence, emerin and lamin A/C play critical roles in suppressing VSMC hyperproliferation induced by hyperstretch. ChIP-on-chip and MOTIF analyses showed that the DNAs binding with emerin contain three transcription factor motifs: CCNGGA, CCMGCC, and ABTTCCG; DNAs binding with lamin A/C contain the motifs CVGGAA, GCCGCYGC, and DAAGAAA. Protein/DNA array proved that altered emerin or lamin A/C expression modulated the activation of various transcription factors. Furthermore, accelerating local expression of emerin or lamin A/C reversed cell proliferation in the carotid artery of hypertensive rats in vivo. Our findings establish the pathogenetic role of emerin and lamin A/C repression in stretch-induced VSMC proliferation and suggest mechanobiological mechanism underlying this process that involves the sequence-specific binding of emerin and lamin A/C to specific transcription factor motifs.

We developed a quantum-dot-based fluorescence resonance energy transfer (QD-FRET) nanosensor to visualize the activity of matrix metalloproteinase (MT1-MMP) at cell membrane. A bended peptide with multiple motifs was engineered to position the FRET pair at a close proximity to allow energy transfer, which can be cleaved by active MT1-MMP to result in FRET changes and the exposure of cell penetrating sequence. Via FRET and penetrated QD signals, the nanosensor can profile cancer cells.

The dysfunction of vascular endothelial cells (ECs) influenced by flow shear stress is crucial for vascular remodeling. However, the roles of nuclear envelope (NE) proteins in shear stress-induced EC dysfunction are still unknown. Our results indicated that, compared with normal shear stress (NSS), low shear stress (LowSS) suppressed the expression of two types of NE proteins, Nesprin2 and LaminA, and increased the proliferation and apoptosis of ECs. Targeted small interfering RNA (siRNA) and gene overexpression plasmid transfection revealed that Nesprin2 and LaminA participate in the regulation of EC proliferation and apoptosis. A protein/DNA array was further used to detect the activation of transcription factors in ECs following transfection with target siRNAs and overexpression plasmids. The regulation of AP-2 and TFIID mediated by Nesprin2 and the activation of Stat-1, Stat-3, Stat-5 and Stat-6 by LaminA were verified under shear stress. Furthermore, using Ingenuity Pathway Analysis software and real-time RT-PCR, the effects of Nesprin2 or LaminA on the downstream target genes of AP-2, TFIID, and Stat-1, Stat-3, Stat-5 and Stat-6, respectively, were investigated under LowSS. Our study has revealed that NE proteins are novel mechano-sensitive molecules in ECs. LowSS suppresses the expression of Nesprin2 and LaminA, which may subsequently modulate the activation of important transcription factors and eventually lead to EC dysfunction.