Role and mechanism of tissue plasminogen activator in venous wall fibrosis remodeling after deep venous thrombosis via the glycogen synthase kinase-3 beta signaling pathway

Hormonal influence: unraveling the impact of sex hormones on vascular smooth muscle cells

Sex hormones play a pivotal role as endocrine hormones that exert profound effects on the biological characteristics and vascular function of vascular smooth muscle cells (VSMCs). By modulating intracellular signaling pathways, activating nuclear receptors, and regulating gene expression, sex hormones intricately influence the morphology, function, and physiological state of VSMCs, thereby impacting the biological properties of vascular contraction, relaxation, and growth. Increasing evidence suggests that abnormal phenotypic changes in VSMCs contribute to the initiation of vascular diseases, including atherosclerosis. Therefore, understanding the factors governing phenotypic alterations in VSMCs and elucidating the underlying mechanisms can provide crucial insights for refining interventions targeted at vascular diseases. Additionally, the varying levels of different types of sex hormones in the human body, influenced by sex and age, may also affect the phenotypic conversion of VSMCs. This review aims to explore the influence of sex hormones on the phenotypic switching of VSMCs and the development of associated vascular diseases in the human body.

TNFα activation and TGFβ blockage act synergistically for smooth muscle cell calcification in patients with venous thrombosis via TGFβ/ERK pathway

Venous calcification has been observed in post‐thrombotic syndrome (PTS) patients; yet, the cell types and possible mechanisms regulating this process are still unclear. We evaluated the calcium deposition within the venous wall, the cell type involved in the calcified remodelling of the venous wall after thrombosis and explored possible mechanisms in vitro. Calcium deposition was found in human specimens of superficial thrombotic veins and was co‐localized with VSMCs markers αSMA and TAGLN (also known as SM22α). Besides, the expression of osteogenesis‐related genes was dramatically changed in superficial thrombotic veins. Moreover, the inhibition of the TGFβ signalling pathway after TNFα treatment effectively induced the expression of osteogenic phenotype markers, the calcium salt deposits and the obvious phosphorylation of ERK1/2 and JNK2 in the VSMCs calcification model. Supplementing TGFβ2 or blocking the activation of the ERK/MAPK signalling pathway prevented the transformation of VSMCs into osteoblast‐like cells in vitro. Taken together, VSMCs have an important role in venous calcification after thrombosis. Supplementing TGFβ2 or inhibiting the ERK/MAPK signalling pathway can reduce the appearance of VSMCs osteogenic phenotype. Our findings may present a novel therapeutic approach to prevent of vascular calcification after venous thrombosis.

Integrating microRNA and messenger RNA expression profiles in a rat model of deep vein thrombosis

Deep vein thrombosis (DVT) is a disease involving multiple genes and systems. MicroRNAs (miRNAs) represent a class of non-coding small RNAs that post-transcriptionally suppress their target genes. The expression patterns of miRNA and messenger RNA (mRNA) in DVT remain poorly characterized. The aim of the present study was to evaluate miRNA and mRNA expression profiles in a stasis-induced DVT rat model. Male SD rats were randomly divided into three groups as follows: DVT, sham and control. The inferior vena cava (IVC) of rats was ligated to construct stasis-induced DVT models. Rats were sacrificed three days after ligation, and morphological changes in the vein tissues were observed by hematoxylin and eosin and Masson staining. The miRNA and mRNA expression profiles were evaluated by microarrays, followed by bioinformatics analysis. The microarray analysis identified 22 miRNAs and 487 mRNAs that were significantly differentially expressed between the experimental and control groups, and between the experimental and sham groups, but not between the control and sham groups (P≤0.05; ≥2.0-fold change). By subsequent bioinformatics analysis, a 19 miRNA-98 mRNAs network was constructed in the stasis-induced DVT rat model. Notably, the majority of these miRNAs and mRNAs are reported to be expressed by endothelial cells (ECs) and are associated with the function of ECs. The results provide evidence indicating that the regulatory association of miRNA and mRNA points to key roles played by ECs in thrombosis. These findings advance our understanding of the molecular regulatory mechanisms underlying the pathophysiology of DVT.

β1-Integrin Deletion From the Lens Activates Cellular Stress Responses Leading to Apoptosis and Fibrosis

Purpose

Previous research showed that the absence of β1-integrin from the mouse lens after embryonic day (E) 13.5 (β1MLR10) leads to the perinatal apoptosis of lens epithelial cells (LECs) resulting in severe microphthalmia. This study focuses on elucidating the molecular connections between β1-integrin deletion and this phenotype.

Methods

RNA sequencing was performed to identify differentially regulated genes (DRGs) in β1MLR10 lenses at E15.5. By using bioinformatics analysis and literature searching, Egr1 (early growth response 1) was selected for further study. The activation status of certain signaling pathways (focal adhesion kinase [FAK]/Erk, TGF-β, and Akt signaling) was studied via Western blot and immunohistochemistry. Mice lacking both β1-integrin and Egr1 genes from the lenses were created (β1MLR10/Egr1-/-) to study their relationship.

Results

RNA sequencing identified 120 DRGs that include candidates involved in the cellular stress response, fibrosis, and/or apoptosis. Egr1 was investigated in detail, as it mediates cellular stress responses in various cell types, and is recognized as an upstream regulator of numerous other β1MLR10 lens DRGs. In β1MLR10 mice, Egr1 levels are elevated shortly after β1-integrin loss from the lens. Further, pErk1/2 and pAkt are elevated in β1MLR10 LECs, thus providing the potential signaling mechanism that causes Egr1 upregulation in the mutant. Indeed, deletion of Egr1 from β1MLR10 lenses partially rescues the microphthalmia phenotype.

Conclusions

β1-integrin regulates the appropriate levels of Erk1/2 and Akt phosphorylation in LECs, whereas its deficiency results in the overexpression of Egr1, culminating in reduced cell survival. These findings provide insight into the molecular mechanism underlying the microphthalmia observed in β1MLR10 mice.

Natural product derivative BIO promotes recovery after myocardial infarction via unique modulation of the cardiac microenvironment

The cardiac microenvironment includes cardiomyocytes, fibroblasts and macrophages, which regulate remodeling after myocardial infarction (MI). Targeting this microenvironment is a novel therapeutic approach for MI. We found that the natural compound derivative, BIO ((2′Z,3′E)-6-Bromoindirubin-3′-oxime) modulated the cardiac microenvironment to exert a therapeutic effect on MI. Using a series of co-culture studies, BIO induced proliferation in cardiomyocytes and inhibited proliferation in cardiac fibroblasts. BIO produced multiple anti-fibrotic effects in cardiac fibroblasts. In macrophages, BIO inhibited the expression of pro-inflammatory factors. Significantly, BIO modulated the molecular crosstalk between cardiac fibroblasts and differentiating macrophages to induce polarization to the anti-inflammatory M2 phenotype. In the optically transparent zebrafish-based heart failure model, BIO induced cardiomyocyte proliferation and completely recovered survival rate. BIO is a known glycogen synthase kinase-3β inhibitor, but these effects could not be recapitulated using the classical inhibitor, lithium chloride; indicating novel therapeutic effects of BIO. We identified the mechanism of BIO as differential modulation of p27 protein expression and potent induction of anti-inflammatory interleukin-10. In a rat MI model, BIO reduced fibrosis and improved cardiac performance. Histological analysis revealed modulation of the cardiac microenvironment by BIO, with increased presence of anti-inflammatory M2 macrophages. Our results demonstrate that BIO produces unique effects in the cardiac microenvironment to promote recovery post-MI.

Effects of hesperetin on platelet-derived growth factor-BB-induced pulmonary artery smooth muscle cell proliferation

Hesperetin is a natural flavonoid, which has been reported to exert various biological activities and positive health effects on mammalian cells. The present study aimed to investigate the effects of hesperetin on the proliferation of primary cultured rat pulmonary artery smooth muscle cells (PASMCs), and to elucidate the possible underlying molecular mechanisms. The results of the present study indicated that hesperetin was able to inhibit the proliferation and DNA synthesis of platelet‑derived growth factor‑BB (PDGF‑BB)‑induced PASMCs in a dose‑ and time‑dependent manner, without exerting cell cytotoxicity. In addition, hesperetin blocked the progression of the cell cycle from G0/G1 to S phase, which was correlated with the decreased mRNA expression levels of cyclin D1, cyclin E, cyclin‑dependent kinase (CDK)2 and CDK4, and the increased mRNA expression levels of p27. Furthermore, the anti‑proliferative effects of hesperetin were associated with suppression of the AKT/glycogen synthase kinase (GSK)3β and p38 signaling pathway, but were not associated with the extracellular signal‑regulated kinases 1/2 and c‑Jun N‑terminal kinases signaling pathways. These results suggested that hesperetin may inhibit PDGFa‑BB‑induced PASMC proliferation via the AKT/GSK3β signaling pathway, and that it may possess therapeutic potential for the treatment of pulmonary vascular remodeling diseases.

Molecular contributions to neurovascular unit dysfunctions after brain injuries: lessons for target-specific drug development

The revised 'expanded' neurovascular unit (eNVU) is a physiological and functional unit encompassing endothelial cells, pericytes, smooth muscle cells, astrocytes and neurons. Ischemic stroke and traumatic brain injury are acute brain injuries directly affecting the eNVU with secondary damage, such as blood-brain barrier (BBB) disruption, edema formation and hypoperfusion. BBB dysfunctions are observed at an early postinjury time point, and are associated with eNVU activation of proteases, such as tissue plasminogen activator and matrix metalloproteinases. BBB opening is accompanied by edema formation using astrocytic AQP4 as a key protein regulating water movement. Finally, nitric oxide dysfunction plays a dual role in association with BBB injury and dysregulation of cerebral blood flow. These mechanisms are discussed including all targets of eNVU encompassing endothelium, glial cells and neurons, as well as larger blood vessels with smooth muscle. In fact, the feeding blood vessels should also be considered to treat stroke and traumatic brain injury. This review underlines the importance of the eNVU in drug development aimed at improving clinical outcome after stroke and traumatic brain injury.

Targeted introduction of tissue plasminogen activator (TPA) at the AAVS1 locus in mesenchymal stem cells (MSCs) and its stable and effective expression

Thrombolytic therapy using tissue plasminogen activator (TPA) is an effective method for treating acute myocardial infarction. However, the systemic administration of TPA is associated with the risk of hemorrhage. Mesenchymal stem cells (MSCs) from bone marrow are characterized by low immunogenicity and homing toward damaged tissues and are therefore ideal cell carriers to achieve lesion-targeting medication. In this article, TPA gene was integrated into the AAVS1 of mesenchymal stem cells, which has been confirmed to be a safe chromosomal locus. The targeting efficiency was 83%. The clones with the site-specific integration retained the stem cell traits of MSCs, displayed a normal karyotype and could persistently and effectively express TPA, as demonstrated by an average expression activity of 1.5 units/mL (3.4-fold that of the control group). After subculture and subsequent growth for two weeks, the clones showed an average TPA activity of 1.43 units/mL and exhibited no significant differences among the individual clones. In summary, the foreign TPA gene can be specifically introduced to the AAVS1 locus, whereby it can be stably and effectively expressed. MSCs can serve as cell carriers for the targeted treatment of a thrombus using TPA.