miR-33-5p knockdown attenuates abdominal aortic aneurysm progression via promoting target adenosine triphosphate-binding cassette transporter A1 expression and activating the PI3K/Akt signaling pathway

Roles and Mechanisms of miRNAs in Abdominal Aortic Aneurysm: Signaling Pathways and Clinical Insights

PURPOSE OF REVIEW

Abdominal aortic aneurysm refers to a serious medical condition that can cause the irreversible expansion of the abdominal aorta, which can lead to ruptures that are associated with up to 80% mortality. Currently, surgical and interventional procedures are the only treatment options available for treating abdominal aortic aneurysm patients. In this review, we focus on the upstream and downstream molecules of the microRNA-related signaling pathways and discuss the roles, mechanisms, and targets of microRNAs in abdominal aortic aneurysm modulation to provide novel insights for precise and targeted drug therapy for the vast number of abdominal aortic aneurysm patients.

RECENT FINDINGS

Recent studies have highlighted that microRNAs, which are emerging as novel regulators of gene expression, are involved in the biological activities of regulating abdominal aortic aneurysms. Accumulating studies suggested that microRNAs modulate abdominal aortic aneurysm development through various signaling pathways that are yet to be comprehensively summarized. A total of six signaling pathways (NF-κB signaling pathway, PI3K/AKT signaling pathway, MAPK signaling pathway, TGF-β signaling pathway, Wnt signaling pathway, and P53/P21 signaling pathway), and a total of 19 miRNAs are intimately associated with the biological properties of abdominal aortic aneurysm through targeting various essential molecules. MicroRNAs modulate the formation, progression, and rupture of abdominal aortic aneurysm by regulating smooth muscle cell proliferation and phenotype change, vascular inflammation and endothelium function, and extracellular matrix remodeling. Because of the broad crosstalk among signaling pathways, a comprehensive analysis of miRNA-mediated signaling pathways is necessary to construct a well-rounded upstream and downstream regulatory network for future basic and clinical research of AAA therapy.

Advances and challenges in regenerative therapies for abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a significant source of mortality worldwide and carries a mortality of greater than 80% after rupture. Despite extensive efforts to develop pharmacological treatments, there is currently no effective agent to prevent aneurysm growth and rupture. Current treatment paradigms only rely on the identification and surveillance of small aneurysms, prior to ultimate open surgical or endovascular repair. Recently, regenerative therapies have emerged as promising avenues to address the degenerative changes observed in AAA. This review briefly outlines current clinical management principles, characteristics, and pharmaceutical targets of AAA. Subsequently, a thorough discussion of regenerative approaches is provided. These include cellular approaches (vascular smooth muscle cells, endothelial cells, and mesenchymal stem cells) as well as the delivery of therapeutic molecules, gene therapies, and regenerative biomaterials. Lastly, additional barriers and considerations for clinical translation are provided. In conclusion, regenerative approaches hold significant promise for in situ reversal of tissue damages in AAA, necessitating sustained research and innovation to achieve successful and translatable therapies in a new era in AAA management.

miRNA Regulation of Cell Phenotype and Parietal Remodeling in Atherosclerotic and Non-Atherosclerotic Aortic Aneurysms: Differences and Similarities

Aortic aneurysms are a serious health concern as their rupture leads to high morbidity and mortality. Abdominal aortic aneurysms (AAAs) and thoracic aortic aneurysms (TAAs) exhibit differences and similarities in their pathophysiological and pathogenetic features. AAA is a multifactorial disease, mainly associated with atherosclerosis, characterized by a relevant inflammatory response and calcification. TAA is rarely associated with atherosclerosis and in some cases is associated with genetic mutations such as Marfan syndrome (MFS) and bicuspid aortic valve (BAV). MFS-related and non-genetic or sporadic TAA share aortic degeneration with endothelial-to-mesenchymal transition (End-Mt) and fibrosis, whereas in BAV TAA, aortic degeneration with calcification prevails. microRNA (miRNAs) contribute to the regulation of aneurysmatic aortic remodeling. miRNAs are a class of non-coding RNAs, which post-transcriptionally regulate gene expression. In this review, we report the involvement of deregulated miRNAs in the different aortic remodeling characterizing AAAs and TAAs. In AAA, miRNA deregulation appears to be involved in parietal inflammatory response, smooth muscle cell (SMC) apoptosis and aortic wall calcification. In sporadic and MFS-related TAA, miRNA deregulation promotes End-Mt, SMC myofibroblastic phenotypic switching and fibrosis with glycosaminoglycan accumulation. In BAV TAA, miRNA deregulation sustains aortic calcification. Those differences may support the development of more personalized therapeutic approaches.

Etiology of lipid-laden macrophages in the lung

Uniquely positioned as sentinel cells constantly exposed to the environment, pulmonary macrophages are vital for the maintenance of the lung lining. These cells are responsible for the clearance of xenobiotics, pathogen detection and clearance, and homeostatic functions such as surfactant recycling. Among the spectrum of phenotypes that may be expressed by macrophages in the lung, the pulmonary lipid-laden phenotype is less commonly studied in comparison to its circulatory counterpart, the atherosclerotic lesion-associated foam cell, or the acutely activated inflammatory macrophage. Herein, we propose that lipid-laden macrophage formation in the lung is governed by lipid acquisition, storage, metabolism, and export processes. The cellular balance of these four processes is critical to the maintenance of homeostasis and the prevention of aberrant signaling that may contribute to lung pathologies. This review aims to examine mechanisms and signaling pathways that are involved in lipid-laden macrophage formation and the potential consequences of this phenotype in the lung.

Functional significance of cholesterol metabolism in cancer: from threat to treatment

Cholesterol is an essential structural component of membranes that contributes to membrane integrity and fluidity. Cholesterol homeostasis plays a critical role in the maintenance of cellular activities. Recently, increasing evidence has indicated that cholesterol is a major determinant by modulating cell signaling events governing the hallmarks of cancer. Numerous studies have shown the functional significance of cholesterol metabolism in tumorigenesis, cancer progression and metastasis through its regulatory effects on the immune response, ferroptosis, autophagy, cell stemness, and the DNA damage response. Here, we summarize recent literature describing cholesterol metabolism in cancer cells, including the cholesterol metabolism pathways and the mutual regulatory mechanisms involved in cancer progression and cholesterol metabolism. We also discuss various drugs targeting cholesterol metabolism to suggest new strategies for cancer treatment.

Effects of miR-33 Deficiency on Metabolic and Cardiovascular Diseases: Implications for Therapeutic Intervention

MicroRNAs (miRNAs) are small noncoding RNAs that post-transcriptionally inhibit gene expression. These small molecules are involved in several biological conditions such as inflammation, cell growth and proliferation, and regulation of energy metabolism. In the context of metabolic and cardiovascular diseases, miR-33 is of particular interest as it has been implicated in the regulation of lipid and glucose metabolism. This miRNA is located in introns harboured in the genes encoding sterol regulatory element-binding protein (SREBP)-1 and SREBP-2, which are key transcription factors involved in lipid biosynthesis and cholesterol efflux. This review outlines the role of miR-33 in a range of metabolic and cardiovascular pathologies, such as dyslipidaemia, nonalcoholic fatty liver disease (NAFLD), obesity, diabetes, atherosclerosis, and abdominal aortic aneurysm (AAA), and it provides discussion about the effectiveness of miR-33 deficiency as a possible therapeutic strategy to prevent the development of these diseases.

Exosomal microRNA-342-5p from human umbilical cord mesenchymal stem cells inhibits preeclampsia in rats

We aimed to investigate the inhibitory effect of human umbilical cord mesenchymal stem cell (hucMSC)-derived exosomes (hucMSC-Exos) transmitting microRNA-342-5p (miR-342-5p) on the development of preeclampsia (PE) by targeting programmed cell death 4 (PDCD4). The primary hucMSCs were cultured and transfected with miR-342-5p, and the exosomes (Exo) were extracted from the hucMSCs. PE rats were performed with an intraperitoneal injection of L-NAME from days 11 to 19 of gestation, and injection of Exo, Exo-negative control (NC), Exo-miR-342-5p agomir, Exo-miR-342-5p antagomir, and overexpressing PDCD4 (oe-PDCD4) vector into the placenta on the 16th day of pregnancy. HE staining was utilized to observe the pathological changes in placental tissues. TUNEL staining was implemented to evaluate cell apoptosis in placental tissues. Blood pressure and 24-h urinary protein in pregnant rats were measured by a non-invasive rat tail artery blood pressure measurement and protein auto-analyzer. Expressions of miR-342-5p, PDCD4, proinflammatory cytokines (TNF-α and IL-1β), and anti-inflammatory cytokines (IL-10 and TGF-β) were detected by RT-qPCR, and PDCD4 protein expression was determined by Western blot. The interaction between miR-342-5p and PDCD4 was analyzed by luciferase activity assay. MiR-342-5p was downregulated while PDCD4 was upregulated in the placental tissues of PE rats. HucMSC-Exo relieved pathology and suppressed inflammatory response, and apoptosis in the placental tissues, as well as reducing blood pressure and 24-h urinary protein of PE rats. Elevated miR-342-5p enhanced the promoting influence of hucMSC-Exo on PE rats, while inhibited miR-342-5p reversed the functions of hucMSC-Exo on PE rats. miR-342-5p targeted PDCD4. Overexpression of PDCD4 worsened the development of PE in rats. HucMSC-Exo conveying elevated miR-342-5p inhibits the development of PE in a rat model through downregulating PDCD4.

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 human umbilical cord mesenchymal stem cells-derived exosomal microRNA-431-5p in survival and prognosis of colorectal cancer patients

We aim to discuss the role of miR-431-5p in colorectal cancer (CRC) progression via regulating peroxiredoxin 1 (PRDX1). miR-431-5p and PRDX1 expression were detected in CRC tissues and cells, and the relationship between miR-431-5p expression and prognosis of CRC patients was analyzed. Exosomes were extracted from human umbilical cord mesenchymal stem cells (hUCMSCs) and co-cultured with LoVo cells. MTT assay, flow cytometry and Transwell assay were implemented to test cell viability, apoptosis and invasion and migration ability, respectively. The tumor growth was determined as well, and the binding relation between miR-431-5p and PRDX1 was confirmed. miR-431-5p was downregulated and PRDX1 was upregulated in CRC, and miR-431-5p downregulation was associated with poor prognosis. hUCMSC-Exos suppressed the malignant behaviors of LoVo cells, and overexpression of miR-431-5p further aggravated the inhibitory effect of hUCMSC-Exos on LoVo cells. hUCMSC-Exos inhibited PRDX1 expression via miR-431-5p. PRDX1 was targeted by miR-431-5p. miR-431-5p serves as a prognostic biomarker in CRC, and hUCMSC-Exos transfer of miR-431-5p decelerates CRC cell growth by inhibiting PRDX1.

Long non-coding RNA PVT1/microRNA miR-3127-5p/NCK-associated protein 1-like axis participates in the pathogenesis of abdominal aortic aneurysm by regulating vascular smooth muscle cells

The long non-coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) has been implicated in the progression of abdominal aortic aneurysms (AAA). However, the detailed mechanism requires further analysis. Our study was aimed at interrogating the mechanism of PVT1 in an H₂O₂-induced AAA model in vitro. The expression of lncRNA PVT1, microRNA miR-3127-5p, and NCK-associated protein 1-like (NCKAP1L) was examined in AAA tissues and H₂O₂-treated vascular smooth muscle cells (VSMCs). Cell proliferation was assayed using Cell Counting Kit-8 (CCK8) and 5-Bromodeoxyuridine (BrdU) assays. Meanwhile, 5-Ethynyl-2'-deoxyuridine (EdU) staining was performed to assess cell apoptosis and caspase-3 activity. IL-1β and caspase-1 expression was also assessed using Western blotting to determine inflammasome activation in H₂O₂-treated VSMCs. Luciferase reporter assays addressed the possible interaction between miR-3127-5p and PVT1 or NCKAP1L, which was predicted by starBase analysis. PVT1 and NCKAP1L expression was elevated in AAA tissues and induced the AAA model in vitro, whereas miR-3127-5p showed the opposite trend. Functionally, PVT1 silencing promoted cell proliferation and reduced the apoptotic rate and inflammasome activation in H₂O₂-treated VSMCs. Mechanical investigation demonstrated that PVT1 acted as a sponge of miR-3127-5p to modulate NCKAP1L expression, resulting in suppression of VSMC proliferation, induction of apoptosis, and activation of inflammation. In conclusion, PVT1 participates in AAA progression through the miR-3127-5p/NCKAP1L axis and may be a promising biosignature and therapeutic target for AAA.

Genomic Variants and Multilevel Regulation of ABCA1, ABCG1, and SCARB1 Expression in Atherogenesis

Atheroprotective properties of human plasma high-density lipoproteins (HDLs) are determined by their involvement in reverse cholesterol transport (RCT) from the macrophage to the liver. ABCA1, ABCG1, and SR-BI cholesterol transporters are involved in cholesterol efflux from macrophages to lipid-free ApoA-I and HDL as a first RCT step. Molecular determinants of RCT efficiency that may possess diagnostic and therapeutic meaning remain largely unknown. This review summarizes the progress in studying the genomic variants of ABCA1, ABCG1, and SCARB1, and the regulation of their function at transcriptional and post-transcriptional levels in atherosclerosis. Defects in the structure and function of ABCA1, ABCG1, and SR-BI are caused by changes in the gene sequence, such as single nucleotide polymorphism or various mutations. In the transcription initiation of transporter genes, in addition to transcription factors, long noncoding RNA (lncRNA), transcription activators, and repressors are also involved. Furthermore, transcription is substantially influenced by the methylation of gene promoter regions. Post-transcriptional regulation involves microRNAs and lncRNAs, including circular RNAs. The potential biomarkers and targets for atheroprotection, based on molecular mechanisms of expression regulation for three transporter genes, are also discussed in this review.

Anesthetics mediated the immunomodulatory effects via regulation of TLR signaling

Anesthetics have been widely used in surgery and found to suppress inflammatory injury and affect the outcomes of the surgery and diseases. In contrast, anesthetics are also found to induce neuronal injury and inflammation. However, the immune-modulation mechanism of anesthetics is still not clear. Recent studies have shown that the immune-modulation of anesthetics is associated with the regulation of toll-like receptor (TLR)-mediated signaling. Moreover, the regulation of anesthetics in TLR signaling is related to modulations of non-coding RNAs (nc RNAs). Consistently, nc RNAs are mainly divided into micro RNAs (miRs) and long non-coding RNAs (lnc RNAs), which have been found to exert regulatory effects on the immune system. In this review, we summarize the immunomodulatory functions of the widely used anesthetic agents, which are associated with regulation of TLR signaling. In addition, we also focus on the roles of nc RNAs induced by anesthetics in regulations of TLR signaling.

Long non-coding RNA PROX1-AS1 knockdown upregulates microRNA-519d-3p to promote chemosensitivity of retinoblastoma cells via targeting SOX2

OBJECTIVE

Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) participate in tumor progression, while the role of PROX1-antisense RNA1 (PROX1-AS1) sponging miR-519d-3p in retinoblastoma (RB) remains largely unknown. We aim to explore the effect of the PROX1-AS1/miR-519d-3p/sex determining region Y-box 2 (SOX2) in chemosensitivity of RB cells.

METHODS

Expression of PROX1-AS1, miR-519d-3p and SOX2 in RB tissues and cells was determined. The drug-resistant cell lines were established and respectively intervened with PROX1-AS1 or miR-519d-3p expression to explore their roles in drug resistance and malignant behaviors of the drug-resistant cells. The binding relationships between PROX1-AS1 and miR-519d-3p, and between miR-519d-3p and SOX2 were evaluated.

RESULTS

PROX1-AS1 and SOX2 were upregulated while miR-519d-3p was downregulated in RB tissues and cells, especially in drug-resistant cells. The PROX1-AS1 inhibition or miR-519d-3p elevation suppressed the drug resistance, proliferation, migration and invasion, and promoted apoptosis of the drug-resistant RB cells. Moreover, PROX1-AS1 sponged miR-519d-3p and miR-519d-3p targeted SOX2.

CONCLUSION

PROX1-AS1 knockdown upregulates miR-519d-3p to promote chemosensitivity of RB cells via targeting SOX2.

MicroRNA-33-5p inhibits cholesterol efflux in vascular endothelial cells by regulating citrate synthase and ATP-binding cassette transporter A1

Background

A high level of total cholesterol is associated with several lipid metabolism disorders, including atherosclerosis and cardiovascular diseases. ATP-binding cassette (ABC) transporter A1 (ABCA1) and miR-33-5p play crucial roles in atherosclerosis by controlling cholesterol efflux. While citrate is a precursor metabolite for lipid and cholesterol synthesis, little is known about the association between citrate synthase (CS) and cholesterol efflux. This study investigated the role of the miR-33-5p/ABCA1/CS axis in regulating cholesterol efflux in vascular endothelial cells (VECs).

Materials and methods

VECs were treated with oxidized low-density lipoprotein cholesterol (ox-LDL), or pretreated with plasmids overexpressing CS, ABCA1, siRNAs against CS and ABCA1, and an miR-33-5p inhibitor. Cell apoptosis, cellular senescence-associated β-galactosidase activity, inflammation, and cholesterol efflux were detected.

Results

Treatment with ox-LDL decreased ABCA1 and CS levels and increased miR-33-5p expression and apoptosis in dose-dependent manners. In contrast, treatment with the miR-33-5p inhibitor and ABCA1 and CS overexpression plasmids inhibited the above-mentioned ox-LDL-induced changes. In addition, treatment with ox-LDL decreased cholesterol efflux, induced aging, and promoted the production of inflammatory cytokines (i.e., IL-6 and tumor necrosis factor TNF-α), as well as the expression of Bax and Caspase 3 proteins in VECs. All these changes were rescued by miR-33-5p inhibition and ABCA1 and CS overexpression. The inhibition of ABCA1 and CS by siRNAs eliminated the effects mediated by the miR-33-5p inhibitor, and knockdown of CS eliminated the effects of ABCA1 on VECs.

Conclusions

This study demonstrated the crucial roles played by the miR-33-5p/ABCA1/CS axis in regulating cholesterol efflux, inflammation, apoptosis, and aging in VECs, and also suggested the axis as a target for managing lipid metabolism disorders.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02228-7.

Cancer-associated fibroblasts-derived exosomes upregulate microRNA-135b-5p to promote colorectal cancer cell growth and angiogenesis by inhibiting thioredoxin-interacting protein

OBJECTIVE

The role of exosomes in human cancers has been identified, while the effect of cancer-associated fibroblasts (CAFs)-derived exosomes (CAF-exos) transmitting microRNAs (miRNAs) on colorectal cancer (CRC) remains largely unknown. We aim to explore the impact of CAF-derived exosomal miR-135b-5p on CRC progression by targeting thioredoxin-interacting protein (TXNIP).

METHODS

CRC tissues were collected to obtain CAF-exos, which were used to co-culture with LoVo and HT29 cells. The effect of miR-135b-5p and TXNIP on the in vivo growth, in vitro proliferation, apoptosis, migration, invasion and angiogenesis of CRC cells. miR-135b-5p and TXNIP expression in exosomes and CRC cells were detected and their targeting relationship was confirmed.

RESULTS

MiR-135b-5p was upregulated whereas TXNIP was downregulated in CRC tissues and cells. The CAF-exos and CAF-exos upregulating miR-135b-5p promoted in vivo growth, in vitro proliferation, migration and invasion, and suppressed apoptosis of CRC cells, and also promoted the HUVEC angiogenesis. TXNIP was confirmed as a target of miR-135b-5p and overexpression of TXNIP could weaken the pro-CRC effect of exosomal miR-135b-5p, CONCLUSION: CAF-exos upregulate miR-135b-5p to promote CRC cell growth and angiogenesis by inhibiting TXNIP.

Circular RNA Expression: Its Potential Regulation and Function in Abdominal Aortic Aneurysms

Abdominal aortic aneurysms (AAAs) have posed a great threat to human life, and the necessity of its monitoring and treatment is decided by symptomatology and/or the aneurysm size. Accumulating evidence suggests that circular RNAs (circRNAs) contribute a part to the pathogenesis of AAAs. circRNAs are novel single-stranded RNAs with a closed loop structure and high stability, having become the candidate biomarkers for numerous kinds of human disorders. Besides, circRNAs act as molecular "sponge" in organisms, capable of regulating the transcription level. Here, we characterize that the molecular mechanisms underlying the role of circRNAs in AAA development were further elucidated. In the present work, studies on the biosynthesis, bibliometrics, and mechanisms of action of circRNAs were aims comprehensively reviewed, the role of circRNAs in the AAA pathogenic mechanism was illustrated, and their potential in diagnosing AAAs was examined. Moreover, the current evidence about the effects of circRNAs on AAA development through modulating endothelial cells (ECs), macrophages, and vascular smooth muscle cells (VSMCs) was summarized. Through thorough investigation, the molecular mechanisms underlying the role of circRNAs in AAA development were further elucidated. The results demonstrated that circRNAs had the application potential in the diagnosis and prevention of AAAs in clinical practice. The study of circRNA regulatory pathways would be of great assistance to the etiologic research of AAAs.

hsa-miR-33-5p as a Therapeutic Target Promotes Apoptosis of Breast Cancer Cells via Selenoprotein T

Objective: Increasing evidence suggests that microRNA (miRNA) participates in regulating tumor cell apoptosis. We aimed to observe the effect of hsa-miR-33-5p on the apoptosis of breast cancer cells and to explore its regulatory relationship with selenoprotein T (SelT).

Methods: RT-qPCR was used to examine the expression of hsa-miR-33-5p and SelT both in breast cancer tissues and cells. MCF-7 and MDA-MB-231 cells were transfected with hsa-miR-33-5p mimics or si-SelT. Then, a flow cytometry assay was carried out to examine the apoptosis of cells. Furthermore, SelT and apoptosis-related proteins including caspase-3, caspase-8, caspase-9, Bax, and Bcl-2 were detected via RT-qPCR and western blot. A luciferase reporter assay was utilized for assessing whether SelT was targeted by hsa-miR-33-5p.

Results: Downregulated hsa-miR-33-5p was found both in breast cancer tissues and cells. After its overexpression, MCF-7 cell apoptosis was significantly promoted. Furthermore, our data showed that miR-33-5p elevated apoptosis-related protein expression in MCF-7 cells. Contrary to hsa-miR-33-5p, SelT was upregulated both in breast cancer tissues and cells. SelT expression was significantly inhibited by hsa-miR-33-5p overexpression. The luciferase reporter assay confirmed that SelT was a direct target of hsa-miR-33-5p. SelT overexpression could ameliorate the increase in apoptosis induced by hsa-miR-33-5p mimics.

Conclusion: Our findings revealed that hsa-miR-33-5p, as a potential therapeutic target, could accelerate breast cancer cell apoptosis.

MiR-17-5p promotes the endothelialization of endothelial progenitor cells to facilitate the vascular repair of aneurysm by regulating PTEN-mediated PI3K/AKT/VEGFA pathway

The endothelialization of endothelial progenitor cells (EPCs) was proven to facilitate the vascular repair of aneurysm. MiR-17-5p regulated angiogenesis in various cancers. This research focused on exploring the effect of miR-17-5p on EPCs and the vascular repair of aneurysm. In vivo study: the aneurysm rat model was established and treated with AgomiR-17-5p; the histopathology of aneurysm tissues was examined by hematoxylin-eosin staining; and the level of EPCs in the aneurysm tissues and peripheral blood of rats were evaluated by immunofluorescence and flow cytometry, respectively. In vitro study: EPCs were cultured and identified using flow cytometry; the target of miR-17-5p was proven by dual-luciferase reporter assay; after transfection, the viability, migration, and tube formation of the EPCs were detected by MTT, wound healing, and tube formation assays, respectively; the expressions of VEGFA and factors related to PTEN-mediated PI3K/AKT pathway were detected by ELISA, qPCR, or Western blot as needed. In vivo study: miR-17-5p overexpression promoted the vascular repair in aneurysm rats and increased the level of EPCs in the aneurysm tissues and peripheral blood of the rats. In vitro study: miR-17-5p overexpression promoted the viability, migration, and tube formation of EPCs, up-regulated the expressions of VEGFA, p-PI3K, and p-AKT, and down-regulated the PTEN expression in EPCs; miR-17-5p silencing did the opposite; PTEN was targeted by miR-17-3p and further abrogated the effects of miR-17-5p overexpression on EPCs. MiR-17-5p promoted the endothelialization of EPCs to facilitate the vascular repair of aneurysm by regulating PTEN-mediated PI3K/AKT/VEGFA pathway.

The role of autophagy in abdominal aortic aneurysm: protective but dysfunctional

Autophagy, an evolutionarily conserved mechanism that promotes cell survival by recycling nutrients and degrading long-lived proteins and dysfunctional organelles, is an important defense mechanism, and its attenuation has been well documented in senescence and aging-related diseases. Abdominal aortic aneurysm (AAA), a well-known aging-related disease, has been defined as a chronic degenerative process in the abdominal aortic wall; however, the complete mechanism is unknown, and a clinical treatment is lacking. Accumulating evidence has recently revealed that numerous drugs that can induce autophagy are effective in the treatment of AAA. The purpose of this systematic review was to focus on the cross-talk between autophagy and high-risk factors and the potential pathogenesis of AAA to understand not only the host defense and pathogenesis but also potential treatments.