Apoptosis Of Smooth Muscle Cells Research Articles

Intracranial aneurysm circulating exosome-derived LncRNA ATP1A1-AS1 promotes smooth muscle cells phenotype switching and apoptosis.

Exosomal long non-coding RNAs (LncRNAs) play a crucial role in the pathogenesis of cerebrovascular diseases. However, the expression profiles and functional significance of exosomal LncRNAs in intracranial aneurysms (IAs) remain poorly understood. Through high-throughput sequencing, we identified 1303 differentially expressed LncRNAs in the plasma exosomes of patients with IAs and healthy controls. Quantitative real-time polymerase chain reaction (qRT-PCR) verification confirmed the differential expression of LncRNAs, the majority of which aligned with the sequencing results. ATP1A1-AS1 showed the most significant upregulation in the disease group. Importantly, subsequent in vitro experiments validated that ATP1A1-AS1 overexpression induced a phenotype switching in vascular smooth muscle cells, along with promoting apoptosis and upregulating MMP-9 expression, potentially contributing to IAs formation. Furthermore, expanded-sample validation affirmed the high diagnostic value of ATP1A1-AS1. These findings suggest that ATP1A1-AS1 is a potential therapeutic target for inhibiting IAs progression and serves as a valuable clinical diagnostic marker.

Pentamethylquercetin attenuates angiotensin II-induced abdominal aortic aneurysm formation by blocking nuclear translocation of C/EBPβ at Lys253

BackgroundPentamethylquercetin (PMQ) is a natural polymethyl flavonoid that possesses anti-apoptotic and other biological properties. Abdominal aortic aneurysm (AAA), a fatal vascular disease with a high risk of rupture, is associated with phenotypic switching and apoptosis of medial vascular smooth muscle cells (VSMCs). This study aimed to investigate the protective effects of PMQ on the development of AAA and the underlying mechanism. MethodsApoE−/− mice were continuously infused with angiotensin II (Ang II) for 4 weeks to develop the AAA model. Intragastric administration of PMQ was initiated 5 days before Ang II infusion and continued for 4 weeks. In vitro, VSMCs were cultured and pretreated with PMQ, stimulated with Ang II. Real-time PCR, western blotting, and immunofluorescence staining were used to examine the roles and mechanisms of PMQ on the phenotypic switching and apoptosis of VSMCs. ResultsPMQ dose-dependently reduced the incidence of Ang II-induced AAA, aneurysm diameter enlargement, elastin degradation, VSMCs phenotypic switching and apoptosis. Furthermore, PMQ also inhibited phenotypic switching and apoptosis in Ang II-stimulated VSMCs. PMQ exerted protective effects by regulating the C/EBPβ/PTEN/AKT/GSK-3β axis. AAV-mediated overexpression of PTEN reduced the therapeutic effects of PMQ in the AAA model mice, suggesting that the effects of PMQ on Ang II-mediated AAA formation were related to the PTEN/AKT/GSK-3β axis. PMQ inhibited VSMCs phenotypic switching and apoptosis by bounding to C/EBPβ at Lys253 with hydrogen bond to regulate C/EBPβ nuclear translocation and PTEN/AKT/GSK-3β axis, thereby inhibiting Ang II-induced AAA formation. ConclusionsPentamethylquercetin inhibits angiotensin II-induced abdominal aortic aneurysm formation by bounding to C/EBPβ at Lys253. Therefore, PMQ prevents the formation of AAA and reduces the incidence of AAA.

Caveolin-1 scaffolding domain-derived peptide enhances erectile function by regulating oxidative stress, mitochondrial dysfunction, and apoptosis of corpus cavernosum smooth muscle cells in rats with cavernous nerve injury

AimIncreased corpus cavernosum smooth muscle cells (CCSMCs) apoptosis in the penis due to cavernous nerve injury (CNI) is a crucial contributor to erectile dysfunction (ED). Caveolin-1 scaffolding domain (CSD)-derived peptide has been found to exert potential antiapoptotic properties. However, whether CSD peptide can alleviate CCSMCs apoptosis and ED in CNI rats remains unknown. The study aimed to determine whether CSD peptide can improve bilateral CNI-induced ED (BCNI-ED) by enhancing the antiapoptotic processes of CCSMCs. Main methodsFifteen 10-week-old male Sprague-Dawley (SD) rats were randomly classified into three groups: sham surgery (Sham) group and BCNI groups that underwent saline or CSD peptide treatment respectively. At 3 weeks postoperatively, erectile function was assessed and the penis tissue was histologically examined. Furthermore, an in vitro model of CCSMCs apoptosis was established using transforming growth factor-beta 1 (TGF-β1) to investigate the mechanism of CSD peptide in treating BCNI-ED. Key findingsIn BCNI rats, CSD peptide significantly prevented ED and decreased oxidative stress, the Bax/Bcl-2 ratio, and the levels of caspase3. TGF-β1-treated CCSMCs exhibited severe oxidative stress, mitochondrial dysfunction, and apoptosis. However, CSD peptide partially reversed these alterations. SignificanceExogenous CSD peptide could improve BCNI-ED by inhibiting oxidative stress, the Bax/Bcl-2 ratio, and caspase3 expression in penile tissue. The underlying mechanism might involve the regulatory effects of CSD peptide on oxidative stress, mitochondrial dysfunction, and apoptosis of CCSMCs following CNI. This study highlights CSD peptide as an effective therapy for post-radical prostatectomy ED (pRP-ED).

CCR10 Deficiency Reduces Blood Pressure Elevations, End-Organ Damage, and Cutaneous Infiltration of Regulatory T Cells in a Murine Model of Hypertension

Emerging evidence suggests a key role for inflammation and immune cell activation in the pathogenesis of hypertension and its associated end-organ damage. Regulatory T cells (Tregs) function primarily to limit inflammation and are generally considered protective in hypertension. However, Treg subsets can also have tissue-specific functions and play pathogenic roles in some inflammatory diseases through mechanisms, such as limiting angiogenesis. As such, the role of Tregs and its subsets in hypertension remain unclear. Recently, we demonstrated that CCR10+ Tregs are selectively decreased in the circulation of hypertensive patients. CCR10 is a key chemokine receptor for recruitment of immune cells to the skin. Although the skin has not been well studied in hypertension, prior reports in humans demonstrate that loss of skin microvessels (microvascular rarefaction) is a putative mechanism for blood pressure (BP) elevations in hypertension. Recent evidence also suggests that Tregs can promote apoptosis of vascular smooth muscle cells and endothelial cells (ECs). Thus, we hypothesized that CCR10+ Tregs promote hypertension through skin infiltration leading to enhanced microvascular rarefaction. Herein, we demonstrate that, compared to normotensive littermates, male mice with angiotensin II (Ang II)-induced hypertension have selectively increased abundance of CCR10+ Tregs in the skin (p=0.0004) with a corresponding decrease in the circulation (p=0.003). These mice also displayed increased cutaneous levels of the CCR10 ligand CCL27 (p=0.0007), suggesting a mechanism for increased CCR10+ Treg infiltration. To test a causal role of CCR10 in hypertension, we infused Ang II in control CCR10+/+ or CCR10-deficient (CCR10−/−) mice for 4 weeks. Our results demonstrate that CCR10−/− mice exhibit significant reductions in systolic blood pressure (p=0.004), albuminuria (p=0.01), and cardiac fibrosis (p=0.04) compared to wild type mice after Ang II infusion. In addition, CCR10−/− mice had a selective decrease in Tregs in the skin (p=0.02) without change in abundance of conventional CD4+ or CD8+ T cells after Ang II. CCR10−/− mice also exhibited greater cutaneous arteriolar density (p=0.02) after Ang II, consistent with reduced skin microvascular rarefaction. Finally, using PrediXcan, we demonstrate that higher genetically predicted levels of CCR10 are associated with increased risk of hypertension in humans. Taken together, our data suggest that CCR10 promotes Ang II-induced BP elevations and associated end-organ injury, at least in part by promoting Treg recruitment to the skin leading to microvascular rarefaction. K08HL153786, 5T32HL144446-05. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Spatiotemporal ATF3 Expression Determines VSMC Fate in Abdominal Aortic Aneurysm.

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. Activating transcription factor (ATF) 3 has been increasingly recognized as a key regulator of cardiovascular diseases. However, the role of ATF3 (activating transcription factor 3) in AAA development and progression remains elusive. 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 adenoassociated virus serotype 9 vectors carrying ATF3, or shRNA-ATF3 with SM22α (smooth muscle protein 22-α) promoter were used in Ang II (angiotensin 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. 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. 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.

Ncf1 knockout in SMCs exacerbates angiotensin II-induced aortic aneurysm and dissection by activating the STING pathway.

Aortic aneurysm and dissection (AAD) is caused by the progressive loss of aortic smooth muscle cells (SMCs) and is associated with a high mortality rate. Identifying the mechanisms underlying SMC apoptosis is crucial for preventing AAD. Neutrophil cytoplasmic factor 1 (Ncf1) is essential in reactive oxygen species (ROS) production and SMC apoptosis; Ncf1 absence leads to autoimmune diseases and chronic inflammation. Here, the role of Ncf1 in angiotensin II (Ang II)-induced AAD was investigated. Ncf1 expression increased in injured SMCs. Bioinformatics analysis identified Ncf1 as a mediator of AAD-associated SMC damage. Ncf1 expression is positively correlated with DNA replication and repair in SMCs of AAD aortas. AAD incidence increased in Ang II-challenged Sm22CreNcf1fl mice. Transcriptomics showed that Ncf1 knockout activated the stimulator of interferon genes (STING) and cell death pathways. The effects of Ncf1 on SMC death and the STING pathway in vitro were examined. Ncf1 regulated the hydrogen peroxide-mediated activation of the STING pathway and inhibited SMC apoptosis. Mechanistically, Ncf1 knockout promoted the ubiquitination of nuclear factor erythroid 2-related factor 2 (NRF2), thereby inhibiting the negative regulatory effect of NRF2 on the stability of STING mRNA and ultimately promoting STING expression. Additionally, the pharmacological inhibition of STING activation prevented AAD progression. Ncf1 deficiency in SMCs exacerbated Ang II-induced AAD by promoting NRF2 ubiquitination and degradation and activating the STING pathway. These data suggest that Ncf1 may be a potential therapeutic target for AAD treatment.

Morphological study of incompetent saphenous veins: apoptosis and ultrastructural changes of smooth muscle cells.

Varicose veins affect approximately 25% of people in industrialized countries. The study aimed at detecting apoptotic cells and histopathological changes in varicose vein walls. Patients (N.=41) with varicose veins and 30 control group patients were divided into two groups according to their age (younger and older than 50 years). Apoptosis was determined by the TUNEL assay, elastin and collagen IV expression by immunohistochemistry and ultrastructural changes by transmission electron microscopy. The results show that the number of apoptotic cells in the layers of varicose veins increased, in particular in a group of patients aged over 50 years. In the varicose veins as compared to control veins the elastic fibers were found to be thinner, more fragmented and disorderly arranged. Elastin and collagen IV expression was found to decline in the intima and the media of varicose veins in both age groups. Electron microscopy demonstrated hypertrophy and degeneration of smooth muscle cells. Furthermore, cells with ultrastructural feature of apoptosis were noted. In the disorganized and expanded extracellular matrix membrane-bound vesicles, ghost bodies with different size and electron density were observed. Ghost bodies seem to bud off from smooth muscle cells and are likely to be involved in extracellular matrix remodeling as they are seen in close contact with collagen fibers. The study demonstrates increase of apoptotic cells in the wall of varicose veins along with vein wall structural abnormalities including alterations of smooth muscle cells and decline of elastin and collagen IV expression.

MicroRNA-503-5p protects streptozotocin-induced erectile dysfunction in diabetic rats by downregulating SYDE2.

Plentiful studies have clarified miRNAs take on a key role in the sexual dysfunction of diabetic rats. This study aimed to figure out microRNA (miR)-503-5p/SYDE2 axis' latent mechanisms in streptozotocin-induced diabetic rat sexual dysfunction. A model of erectile dysfunction (ED) in diabetic rats was established by injecting streptozotocin. MiR-503-5p and SYDE2 in ED rats were altered by injection of miR-503-5p mimic or si/oe-SYDE2. The targeting link between miR-503-5p and SYDE2 was testified. ICP/MAP value was tested by pressure sensor; Penile capillary abundance was assessed; Penile cGMP and AGEs were detected; penile smooth muscle cell apoptosis was assessed; MiR-503-5p and SYDE2 were tested. In streptozotocin-induced ED rats, miR-503-5p was reduced and SYDE2 was elevated. Elevating miR-503-5p or silencing of SYDE2 can enhance penile erection rate, ICP/MAP value, capillary abundance, and cGMP but reduce AGEs and penile smooth muscle cell apoptosis rate in ED rats. Strengthening SYDE2 with elevating miR-503-5p turned around the accelerating effect of elevated miR-503-5p on penile erection in ED rats. SYDE2 was a downstream target gene of miR-503-5p. MiR-503-5p protects streptozotocin-induced sexual dysfunction in diabetic rats by targeting SYDE2.

A decrease in integrin α5β1/FAK is associated with increased apoptosis of aortic smooth muscle cells in acute type a aortic dissection

BackgroundAcute type A aortic dissection (AAAD) is a devastating disease. Human aortic smooth muscle cells (HASMCs) exhibit decreased proliferation and increased apoptosis, and integrin α5β1 and FAK are important proangiogenic factors involved in regulating angiogenesis. The aim of this study was to investigate the role of integrin α5β1 and FAK in patients with AAAD and the potential underlying mechanisms.MethodsAortic tissue samples were obtained from 8 patients with AAAD and 4 organ donors at Zhongshan Hospital of Fudan University. The level of apoptosis in the aortic tissues was assessed by immunohistochemical (IHC) staining and terminal-deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assays. The expression of integrin α5β1 and FAK was determined. Integrin α5β1 was found to be significantly expressed in HASMCs, and its interaction with FAK was assessed via coimmunoprecipitation (Co-IP) analysis. Proliferation and apoptosis were assessed by Cell Counting Kit-8 (CCK-8) assays and flow cytometry after integrin α5β1 deficiency.ResultsThe levels of integrin α5β1 and FAK were both significantly decreased in patients with AAAD. Downregulating the expression of integrin α5β1-FAK strongly increased apoptosis and decreased proliferation in HASMCs, indicating that integrin α5β1-FAK might play an important role in the development of AAAD.ConclusionsDownregulation of integrin α5β1-FAK is associated with increased apoptosis and decreased proliferation in aortic smooth muscle cells and may be a potential therapeutic strategy for AAAD.

Development, techniques, and utility of experimental animal models of thoracic and abdominal aortic aneurysms

Aneurysms are clinical entities that can develop and affect human aorta; and although in most cases they have an asymptomatic course, these pathological dilatations can lead to a lethal outcome when rupture occurs, thus the establishment of predictors is crucial for death prevention. Essential events that take place in the vessel wall have been identified and described, such as inflammation, proteolysis, smooth muscle cell apoptosis, angiogenesis, and vascular remodeling. Porcine and ovinemodels have been useful for the development and evaluation of endovascular devices of the aorta. However, since the worldwide introduction and adoption of these minimally invasive techniques for aneurysm repair, there is lesser availability of diseased aortic tissue for molecular, cellular, and histopathological analysis, therefore over the last three decades it has been proposed various small species models that have allowed the focal induction of these lesions for the study of physiopathological mechanisms and possible useful biomarkers as diagnostic and therapeutic targets. The present review article presents and discusses the animal models available as their applications, characteristics, advantages, and limitations for the development of preclinical studies, and their importance in the comprehension of this pathology in humans.

Application of Photodynamic Therapy in Cardiology.

The origins of photodynamic therapy (PDT) date back to 1904. Since then, the amount of research proving PDT and, consequently, its applicability to various disease states has steadily increased. Currently, PDT is mainly used in oncology to destroy cancer cells. It is being worked on for possible use in other medical fields as well, including cardiology. It can be used in the prevention of restenosis, often occurring after vascular surgical interventions, for destroying atherosclerotic plaques and as a new ablative method of ectopic centers in the treatment of atrial fibrillation. The purpose of this review is to summarize the knowledge to date regarding the therapeutic potential of using PDT for various pathological conditions in cardiology. The review also focuses on the current limitations associated with the use of PDT and identifies areas where more research is needed to develop better drug regimens. Materials and methods: The study analyzed 189 medical articles. The articles came from PubMed, Frontiers, Google Scholar, Science Direct and Web of Science databases. Through the excitation of light, a photosensitizer (PS) introduced into the body, the destruction of pathological cells occurs. PTD is widely used in oncology of the central nervous system (CNS). This process is made possible by the production of free oxygen radicals (ROS) and singlet oxygen, which generate oxidative stress that destroys sensitive cancer cells. In recent years, photosensitizers have also been discovered to have a strong affinity for macrophages that fill atherosclerotic plaques, making these compounds suitable for treating atherosclerosis. By inducing apoptosis of smooth muscle cells, inactivating basic fibroblast growth factor (FGF-β) and inhibiting endothelial cell hyperplasia, PDT can be used to prevent restenosis after surgical proceduresPDT appears to be a minimally invasive and highly effective therapeutic method, especially when combined with other therapeutic methods. Unfortunately, the small number of animal model studies and human clinical trials greatly limit the applicability of PDT on a wider scale. Current limitations, such as the depth of penetration, delivery of photosensitizer particles to the direct site of the lesion or the appropriate choice of photosensitizer in relation to the nature of the pathology, unfortunately make it impossible to replace current therapeutic approaches.

Bronchial thermoplasty decreases airway remodeling by inhibiting autophagy via the AMPK/mTOR signaling pathway.

Bronchial thermoplasty (BT), an effective treatment for severe asthma, requires heat to reach the airway to reduce the mass of airway smooth muscle cells (ASMCs). Autophagy is involved in the pathological process of airway remodeling in patients with asthma. However, it remains unclear whether autophagy participates in controlling airway remodeling induced by BT. In this study, we aim to elucidate the autophagy-mediated molecular mechanisms in BT. Our study reveal that the number of autophagosomes and the level of alpha-smooth muscle actin (α-SMA) fluorescence are significantly decreased in airway biopsy tissues after BT. As the temperature increased, BT causes a decrease in cell proliferation and a concomitant increase in the apoptosis of human airway smooth muscle cells (HASMCs). Furthermore, increase in temperature significantly downregulates cellular autophagy, autophagosome accumulation, the LC3II/LC3I ratio, and Beclin-1 expression, upregulates p62 expression, and inhibits the AMPK/mTOR pathway. Furthermore, cotreatment with AICAR (an AMPK agonist) or RAPA (an mTOR antagonist) abolishes the inhibition of autophagy and attenuates the increase in the apoptosis rate of HASMCs induced by the thermal effect. Therefore, we conclude that BT decreases airway remodeling by blocking autophagy induced by the AMPK/mTOR signaling pathway in HASMCs.

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.

CircCDYL Contributes to Apoptosis, Ferroptosis, and Oxidative Stress of Ang II-Induced Vascular Smooth Muscle Cells in Thoracic Aortic Aneurysm.

Circular RNAs (circRNAs) have important regulation in thoracic aortic aneurysm (TAA). The function and mechanism of circCDYL (circ_0008285) was explored in TAA here. Angiotensin II (Ang II) was used to construct a TAA model. Real-time quantitative polymerase chain reaction (RT-qPCR) was performed for the detection of circCDYL, miR-1270, and a disintegrin and metalloproteinase 10 (ADAM10). Cell viability was examined via cell counting kit-8 (CCK-8) assay and proliferation was analyzed using Ethynyl-2'-deoxyuridine (EdU) assay. Apoptosis rate was assessed via flow cytometry. Western blot was used for protein detection. Oxidative stress was evaluated by commercial kits. CircCDYL was upregulated in TAA tissues and Ang II-induced circCDYL upregulation in vascular smooth muscle cells (VSMCs). Knockdown of circCDYL weakened Ang II-aroused inhibition of viability, proliferation, and promotion of apoptosis, ferroptosis, and oxidative stress in VSMCs. CircCDYL served as a miR-1270 sponge. The mitigated regulation of circCDYL knockdown for Ang II-induced injury was restored after miR-1270 downregulation. CircCDYL positively regulated ADAM10 through interacting with miR-1270. Overexpression of miR-1270 abated Ang II-induced injury by downregulating ADAM10. In conclusion, circCDYL was involved in the Ang II-induced VSMC injury in TAA via the miR-1270/ADAM10 axis.

Cannabidiol protects against acute aortic dissection by inhibiting macrophage infiltration and PMAIP1-induced vascular smooth muscle cell apoptosis

Acute aortic dissection (AAD) progresses rapidly and is associated with high mortality; therefore, there remains an urgent need for pharmacological agents that can protect against AAD. Herein, we examined the therapeutic effects of cannabidiol (CBD) in AAD by establishing a suitable mouse model. In addition, we performed human AAD single-cell RNA sequencing and mouse AAD bulk RNA sequencing to elucidate the potential underlying mechanism of CBD. Pathological assays and in vitro studies were performed to verify the results of the bioinformatic analysis and explore the pharmacological function of CBD. In a β-aminopropionitrile (BAPN)-induced AAD mouse model, CBD reduced AAD-associated morbidity and mortality, alleviated abnormal enlargement of the ascending aorta and aortic arch, and suppressed macrophage infiltration and vascular smooth muscle cell (VSMC) apoptosis. Bioinformatic analysis revealed that the pro-apoptotic gene PMAIP1 was highly expressed in human and mouse AAD samples, and CBD could inhibit Pmaip1 expression in AAD mice. Using human aortic VSMCs (HAVSMCs) co-cultured with M1 macrophages, we revealed that CBD alleviated HAVSMCs mitochondrial-dependent apoptosis by suppressing the BAPN-induced overexpression of PMAIP1 in M1 macrophages. PMAIP1 potentially mediates HAVSMCs apoptosis by regulating Bax and Bcl2 expression. Accordingly, CBD reduced AAD-associated morbidity and mortality and mitigated the progression of AAD in a mouse model. The CBD-induced effects were potentially mediated by suppressing macrophage infiltration and PMAIP1 (primarily expressed in macrophages)-induced VSMC apoptosis. Our findings offer novel insights into M1 macrophages and HAVSMCs interaction during AAD progression, highlighting the potential of CBD as a therapeutic candidate for AAD treatment.

Toll-like receptor 4 mediated autophagy regulates airway smooth muscle cells behavior

Objectives Airway remodeling, a prominent feature of asthma, involves aberrant proliferation, apoptosis, and migration of airway smooth muscle cells (ASMCs). Toll-like receptors (TLRs) are implicated in the regulation of the autophagy pathway. In this study, we aimed to investigate the influence of Toll-like receptor 4 (TLR4) on autophagy and its underlying mechanism in ASMC proliferation, apoptosis, and migration. Methods Histopathological changes in the lungs of asthmatic mice assessed by Hematoxylin-Eosin (HE) and Masson staining. Cell proliferation, apoptosis and migration were evaluated utilizing CCK8, Edu, Flow cytometry and wound heading assays. The effectiveness of siRNA transfection and the expression of TLR4, autophagy, and proliferation-related proteins after siRNA treatment were examined through RT-PCR and Western blot (WB). Conclusion We observed an increase in TLR4 expression and autophagy in a mouse model of OVA-induced asthma. In vitro experiments showed that siRNA-mediated inhibition of TLR4 suppressed autophagy, proliferation, and migration of ASMCs, whereas TLR4 activation by lipopolysaccharide (LPS) had the opposite effect. Furthermore, the autophagy inhibitor 3-Methyladenine (3MA) inhibited ASMCs proliferation and migration while promoting apoptosis. Significantly, our study demonstrated that autophagy inhibition reversed the promotion effect of LPS on ASMC proliferation and migration. These findings suggest that TLR4 may modulate ASMC behavior through the regulation of autophagy.

Downregulation of LILRB4 Promotes Human Aortic Smooth Muscle Cell Contractile Phenotypic Switch and Apoptosis in Aortic Dissection.

Aortic dissection (AD) is a severe vascular disease with high rates of mortality and morbidity. However, the underlying molecular mechanisms of AD remain unclear. Differentially expressed genes (DEGs) were screened by bioinformatics methods. Alterations of histopathology and inflammatory factor levels in β-aminopropionitrile (BAPN)-induced AD mouse model were evaluated through Hematoxylin-Eosin (HE) staining and Enzyme-linked immunosorbent assay (ELISA), respectively. Reverse transcription quantitative real-time polymerase chain reaction was performed to detect DEGs expression. Furthermore, the role of LILRB4 in AD was investigated through Cell Counting Kit-8 (CCK-8), wound healing, and flow cytometry. Western blotting was employed to assess the phenotypic switch and extracellular matrix (ECM)-associated protein expressions in platelet-derived growth factor-BB (PDGF-BB)-stimulated in vitro model of AD. In the AD mouse model, distinct dissection formation was observed. TNF-α, IL-1β, IL-8, and IL-6 levels were higher in the AD mouse model than in the controls. Six hub genes were identified, including LILRB4, TIMP1, CCR5, CCL7, MSR1, and CLEC4D, all of which were highly expressed. Further exploration revealed that LILRB4 knockdown inhibited the cell vitality and migration of PDGF-BB-induced HASMCs while promoting apoptosis and G0/G1 phase ratio. More importantly, LILRB4 knockdown promoted the protein expression of α-SMA and SM22α, while decreasing the expression of Co1, MMP2, and CTGF, which suggested that LILRB4 silencing promoted contractile phenotypic transition and ECM stability. LILRB4 knockdown inhibits the progression of AD. Our study provides a new potential target for the clinical treatment of AD.

Terazosin attenuates abdominal aortic aneurysm formation by downregulating Peg3 expression to inhibit vascular smooth muscle cell apoptosis and senescence

Abdominal aortic aneurysm (AAA), a vascular degenerative disease, is a potentially life-threatening condition characterised by the loss of vascular smooth muscle cells (VSMCs), degradation of extracellular matrix (ECM), inflammation, and oxidative stress. Despite the severity of AAA, effective drugs for treatment are scarce. At low doses, terazosin (TZ) exerts antiapoptotic and anti-inflammatory effects in several diseases, but its potential to protect against AAA remains unexplored. Herein, we investigated the effects of TZ in two AAA animal models: Angiotensin II (Ang II) infusion in Apoe−/− mice and calcium chloride application in C57BL/6J mice. Mice were orally administered with TZ (100 or 1000 μg/kg/day). The in vivo results indicated that low-dose TZ alleviated AAA formation in both models. Low-dose TZ significantly reduced aortic pulse wave velocity without exerting an apparent antihypertensive effect in the Ang II-induced AAA model. Paternally expressed gene 3 (Peg3) was identified via RNA sequencing as a novel TZ target. PEG3 expression was significantly elevated in both mouse and human AAA tissues. TZ suppressed PEG3 expression and reduced the abundance of matrix metalloproteinases (MMP2/MMP9) in the tunica media. Functional experiments and molecular analyses revealed that TZ (10 nM) treatment and Peg3 knockdown effectively prevented Ang II-induced VSMC senescence and apoptosis in vitro. Thus, Peg3, a novel target of TZ, mediates inflammation-induced VSMC apoptosis and senescence. Low-dose TZ downregulates Peg3 expression to attenuate AAA formation and ECM degradation, suggesting a promising therapeutic strategy for AAA.

PCSK9 increases vulnerability of carotid plaque by promoting mitochondrial dysfunction and apoptosis of vascular smooth muscle cells.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) has been recognized as a novel lipid-lowing target. Recent clinical studies suggested the value of inhibiting PCSK9 in decreasing the vulnerability of coronary plaques. However, the evidence of PCSK9-regulated evolution of unstable carotid plaques is unclear, which has limited the use of PCSK9 inhibitor in carotid plaques. This study aimed to determine the effect and molecular mechanisms of PCSK9 on vulnerability of carotid plaques, to provide potential therapeutic targets for stabilizing carotid plaques. The expression of PCSK9 in stable and unstable carotid plaques were examined in tissue and plasma. Human aortic vascular smooth muscle cells (VSMCs) and carotid VSMCs were employed to transfect lentivirus for overexpression and knockdown of PCSK9, respectively. Morphological and functional changes of mitochondria were observed by live-cell imaging. Cell apoptosis was evaluated by propidium iodide staining. RNA-sequencing and biological examinations were performed to explore and validate the underlying mechanisms. Truncated plasmids were employed to identify the functional domain of PCSK9 in regulation of VSMCs' mitochondrial morphology, function and apoptosis. Clinically, PCSK9 was closely related with vulnerability of human carotid plaques. Increased expression of PCSK9 in human VSMCs was accompanied by higher level of apoptosis. At subcellular level of VSMCs, the morphology of mitochondria was shifted toward the fission state, followed by mitochondrial dysfunction. Inhibition of p38 MAPK activation partially rescued the above morphological and behavioral changes caused by PCSK9. Furthermore, inhibiting of dynamin-related protein 1 (DRP1) attenuated PCSK9-related mitochondrial dysfunction and cell apoptosis. The 1-149aa domain of PCSK9 protein was essential to achieve functional regulation to VSMCs. Our findings demonstrated that PCSK9 induced morphology-related mitochondrial dysfunction and apoptosis of VSMCs, which may be related to increased vulnerability of carotid plaque.

Interaction of Sp1 and Setd8 promotes vascular smooth muscle cells apoptosis by activating Mark4 in vascular calcification.

Vascular calcification (VC) is directly related to high mortality in chronic kidney disease (CKD), and cellular apoptosis of vascular smooth muscle cells (VSMCs) is a crucial process in the initiation of VC. Microtubule affinity-regulating kinase 4 (Mark4), known as a serine/threonine protein kinase, can induce cell apoptosis and autophagy by modulating Akt phosphorylation. However, the potential functions and molecular mechanisms of Mark4 in VSMCs apoptosis and calcification need to be further explored. Initially, our data indicated that the mRNA expression of Mark4 was prominently elevated in high phosphorus-stimulated human VSMCs compared with the other members in Marks. Consistently, Mark4 expression was found to be significantly increased in the calcified arteries of both CKD patients and rats. In vitro, silencing Mark4 suppressed apoptosis-specific marker expression by promoting Akt phosphorylation, finally attenuating VSMCs calcification induced by high phosphate. Mechanically, the transcription factor Sp1 was enriched in the Mark4 promoter region and modulated Mark4 transcription. Moreover, SET domain-containing protein 8 (Setd8) was proved to interact with Sp1 and jointly participated in the transcriptional regulation of Mark4. Finally, rescue experiments revealed that Setd8 contributed to VSMCs apoptosis and calcification by modulating Mark4 expression. In conclusion, these findings reveal that Mark4 is transcriptionally activated by Sp1, which is interacted with Setd8, to promote VSMCs calcification through Akt-mediated antiapoptotic effects, suggesting that Mark4 represents a potent and promising therapeutic target for VC in CKD.