Expression of chemokine receptor-4 in bone marrow mesenchymal stem cells on experimental rat abdominal aortic aneurysms and the migration of bone marrow mesenchymal stem cells with stromal-derived factor-1

Integrated analysis of bulk RNA-seq and single-cell RNA-seq reveals the function of pyrocytosis in the pathogenesis of abdominal aortic aneurysm

Pyrocytosis is involved in the development of abdominal aortic aneurysm (AAA), we explored the pyrocytosis-related hub genes in AAA and conducted a diagnostic model based on the pyrocytosis-related genes score (PRGs). A total of 2 bulk RNA-seq (GSE57691 and GSE47472) datasets and pyrocytosis-related genes were integrated to obtain 24 pyrocytosis-related different expression genes (DEGs). The LASSO Cox regression analysis was conducted to filter out 7 genes and further establish the nomogram signature based on the PRGs that exhibited a good diagnosis value. Weighted gene co-expression network analysis (WGCNA) established 14 gene modules and further identified 6 hub genes which were involved in the regulatory process of pyrocytosis in AAA. At the single cell level, we further identified 3 immune cells were highly associated with the pyrocytosis process in AAA. Finally, the cell-cell communication demonstrated that fibroblasts and endothelial cells and myeloid cells maintained close communications. Here, we identified the dysfunctional expressed pyrocytosis-related genes and immune cells in AAA, which provide a comprehensive understanding of the pathogenesis of AAA.

Long Noncoding RNA SBF2-AS1 Promotes Abdominal Aortic Aneurysm Formation through the miRNA-520f-3p/SMARCD1 Axis

Abdominal aortic aneurysm (AAA) is a chronic vascular inflammatory disease. The regulatory mechanisms during AAA formation remain unclear. Bone marrow stem cells (BMSCs) are pluripotent cells capable of regulating the progression of various diseases by delivering exosomes and exosomal lncRNAs. In this study, we investigated its function in AAA by isolating BMSC exosome-derived lncRNA SBF2-AS1. The results showed that BF2-AS1 could be transferred to vascular smooth muscle cells (VSMCs) and human aortic VSMCs (HASMCs) via BMSC-derived exosomes. Depletion of SBF2-AS1 enhanced the cell viability and proliferation of VSMCs. Conversely, SBF2-AS1 knockdown inhibited VSMC apoptosis. Caspase-3 activity was inhibited by depletion of SBF2-AS1, whereas overexpression of SBF2-AS1 in VSMC promoted Caspase-3 activity. SBF2-AS1 enhances SMARCD1 expression by forming miR-520f-3p in VSMC and HASMC. Overexpression of SMARCD1 or miR-520f-3p inhibitor reversed cell viability and caspase-3 activity mediated by SBF2-AS1 depletion in VSMC and HASMC. Therefore, BMSC exosome-derived SBF2-AS1 promotes AAA formation through the miRNA-520f-3p/SMARCD1 axis. Targeting SBF2-AS1 could serve as a promising therapeutic strategy for AAA.

The role of phosphoinositide 3-kinases in immune-inflammatory responses: potential therapeutic targets for abdominal aortic aneurysm

The pathogenesis of abdominal aortic aneurysm (AAA) includes inflammatory responses, matrix metalloproteinases (MMPs) degradation, VSMC apoptosis, oxidative stress, and angiogenesis, among which the inflammatory response plays a key role. At present, surgery is the only curing treatment, and no effective drug can delay AAA progression in clinical practice. Therefore, searching for a signaling pathway related to the immune-inflammatory response is an essential direction for developing drugs targeting AAA. Recent studies have confirmed that the PI3K family plays an important role in many inflammatory diseases and is involved in regulating various cellular functions, especially in the immune-inflammatory response. This review focuses on the role of each isoform of PI3K in each stage of AAA immune-inflammatory response, making available explorations for a deeper understanding of the mechanism of inflammation and immune response during the formation and development of AAA.

The Role of CXC Chemokines in Cardiovascular Diseases

Cardiovascular disease (CVD) is a class of diseases with high disability and mortality rates. In the elderly population, the incidence of cardiovascular disease is increasing annually. Between 1990 and 2016, the age-standardised prevalence of CVD in China significantly increased by 14.7%, and the number of cardiovascular disease deaths increased from 2.51 million to 3.97 million. Much research has indicated that cardiovascular disease is closely related to inflammation, immunity, injury and repair. Chemokines, which induce directed chemotaxis of reactive cells, are divided into four subfamilies: CXC, CC, CX3C, and XC. As cytokines, CXC chemokines are similarly involved in inflammation, immunity, injury, and repair and play a role in many cardiovascular diseases, such as atherosclerosis, myocardial infarction, cardiac ischaemia-reperfusion injury, hypertension, aortic aneurysm, cardiac fibrosis, postcardiac rejection, and atrial fibrillation. Here, we explored the relationship between the chemokine CXC subset and cardiovascular disease and its mechanism of action with the goal of further understanding the onset of cardiovascular disease.

Combined Treatment With CCR1-Overexpressing Mesenchymal Stem Cells and CCL7 Enhances Engraftment and Promotes the Recovery of Simulated Birth Injury-Induced Stress Urinary Incontinence in Rats

Objective: To observe whether urethral injection of chemokine (c-c motif) ligand 7 (CCL7) and overexpressing CC receptor 1 (CCR1) in mesenchymal stem cells (MSCs) can promote their homing and engraftment to the injured tissue, and improve the recovery of simulated birth injury-induced stress urinary incontinence (SUI) in rats.

Methods: Female rats underwent a dual injury consisting of vaginal distension (VD) and pudendal nerve crush (PNC) to induce SUI. Bone marrow-derived MSCs were transduced with lentivirus carrying CCR1 (MSC-CCR1) and green fluorescent protein (GFP). Forty virgin Sprague–Dawley rats were evenly distributed into four groups: sham SUI + MSC-CCR1+CCL7, SUI + MSCs, SUI + MSC-CCR1, and SUI + MSC-CCR1+CCL7 group. The engrafted MSCs in urethra were quantified. Another three groups of rats, including sham SUI + sham MSC-CCR1+CCL7 treatment, SUI + sham MSC-CCR1+CCL7 treatment, and SUI + MSC-CCR1+CCL7 treatment group, were used to evaluate the functional recovery by testing external urethral sphincter electromyography (EUS EMG), pudendal nerve motor branch potentials (PNMBP), and leak point pressure (LPP) 1 week after injury and injection. Urethra and vagina were harvested for histological examination.

Results: The SUI + MSC-CCR1+CCL7 group received intravenous injection of CCR1-overexpressing MSCs and local injection of CCL7 after simulated birth injury had the most engraftment of MSCs to the injured tissues and best functional recovery from SUI compared to other groups. Histological examination showed a partial repair in the SUI + MSC-CCR1+CCL7 group.

Conclusions: Our study demonstrated combined treatment with CCR1-overexpressing MSCs and CCL7 can increase engraftment of MSCs and promote the functional recovery of simulated birth trauma-induced SUI in rats, which could be a new therapeutic strategy for SUI.

Chemokine (C-X-C motif) receptor 2 blockade by SB265610 inhibited angiotensin II-induced abdominal aortic aneurysm in Apo E-/- mice

Inflammation plays a critical role in the development of abdominal aortic aneurysm (AAA). Chemokine receptor CXCR2 mediates inflammatory cell chemotaxis in several diseases. However, the role of CXCR2 in AAA and the underlying mechanisms remain unknown. In this study, we found that the CXCR2 expressions in AAA tissues from human and angiotensin II (Ang II)-infused apolipoprotein E knockout (Apo E^-/-) mice were significantly increased. The pharmacological inhibition of CXCR2 (SB265610) markedly reduced Ang II-induced AAA formation. Furthermore, SB265610 treatment significantly reduced collagen deposition, elastin degradation, the metal matrix metalloprotease expression and accumulation of macrophage cells. In conclusion, these results showed CXCR2 plays a pathogenic role in AAA formation. Inhibition of CXCR2 pathway may represent a novel therapeutic approach to treat AAA.

Modulation of Immune-Inflammatory Responses in Abdominal Aortic Aneurysm: Emerging Molecular Targets

Abdominal aortic aneurysm (AAA), a deadly vascular disease in human, is a chronic degenerative process of the abdominal aorta. In this process, inflammatory responses and immune system work efficiently by inflammatory cell attraction, proinflammatory factor secretion and subsequently MMP upregulation. Previous studies have demonstrated various inflammatory cell types in AAA of human and animals. The majority of cells, such as macrophages, CD4+ T cells, and B cells, play an important role in the diseased aortic wall through phenotypic modulation. Furthermore, immunoglobulins also greatly affect the functions and differentiation of immune cells in AAA. Recent evidence suggests that innate immune system, especially Toll-like receptors, chemokine receptors, and complements are involved in the progression of AAAs. We discussed the innate immune system, inflammatory cells, immunoglobulins, immune-mediated mechanisms, and key cytokines in the pathogenesis of AAA and particularly emphasis on a further trend and application of these interventions. This current understanding may offer new insights into the role of inflammation and immune response in AAA.

In vitro cell behaviors of bone mesenchymal stem cells derived from normal and postmenopausal osteoporotic rats

Postmenopausal osteoporosis (PMO) increases bone fragility and the risk of fractures, and impairs the healing procedure of bone defects in aged women. The stromal cell-derived factor-1α (SDF-1α)/CXC chemokine receptor type 4 (CXCR4) axis helps to maintain the biological and physiological functions of bone marrow mesenchymal stem cells (BMSCs) and increase the homing efficiency of BMSCs. The present study aimed to provide insights into the possible association between migration and osteogenic ability and the SDF-1α/CXCR4 axis in BMSCs derived from a rat model of PMO. In order to do this, the general and SDF-1α/CXCR4-associated biological characteristics as well as associated molecular mechanisms in BMSCs isolated from a PMO rat model (OVX-BMSCs) and normal rats (Sham-BMSCs) were investigated and compared. In comparison with Sham-BMSCs, OVX-BMSCs exhibited an impaired osteogenic ability, but a stronger adipogenic activity as well as a higher proliferative ability. In addition, OVX-BMSCs presented a lower chemotactic activity towards SDF-1α, lower expression levels of CXCR4 and reduced levels of phosphorylated AKT (p-AKT). Therefore, the lower expression levels of CXCR4 and p-AKT may be responsible for the impaired osteogenic ability and lower chemotactic activity towards SDF-1α of OVX-BMSCs.