Yes-associated Protein Overexpression Research Articles

YAP1 exacerbates pyroptosis and senescence in nucleus pulposus cells by promoting BNIP3-mediated mitophagy

Yes-associated protein 1 (YAP1) is a crucial downstream effector of the Hippo pathway that plays a role in regulating inflammation and mitochondrial function. However, whether YAP1 regulates pyroptosis in nucleus pulposus (NP) cells caused by inflammation via mitophagy remains unclear. This study aimed to investigate the effects of YAP1 on the pyroptosis of NP cells induced by LPS. Here, we demonstrated that the protein expression of YAP1 in the NP tissue of degenerative discs was significantly reduced. Next, we found that NLRP3 inflammasome activation in YAP1-overexpressing (YAP1-ov) NP cells was further enhanced in the LPS-induced inflammatory microenvironment. YAP1-ov strongly aggravated inflammation-induced pyroptosis and senescence, but these effects were reversed by the inhibition of BNIP3-mediated mitophagy. However, comparative analysis of the overexpression of YAP1 in normal discs and discs after annulus fibrosus puncture revealed that YAP1-ov accelerated the degeneration of normal discs and attenuated the degeneration of annulus fibrosus punctured discs in vivo. Additionally, YAP1-ov upregulated the expression of TNFAIP3, an anti-inflammatory protective protein, and CLPP, a vital protein in the mitochondrial unfolded protein response, in NP cells. Collectively, the above results revealed that YAP1 exacerbates LPS-induced pyroptosis and senescence of NP cells by promoting BNIP3-mediated mitophagy, which causes disc degeneration. Notably, YAP1-ov mitigated the degeneration of the disc caused by annular needle puncture in vivo, suggesting its potential as a therapeutic candidate foracute IDD injury.

YAP1 preserves tubular mitochondrial quality control to mitigate diabetic kidney disease

Renal tubule cells act as a primary site of injury in diabetic kidney disease (DKD), with dysfunctional mitochondrial quality control (MQC) closely associated with progressive kidney dysfunction in this context. Our investigation delves into the observed inactivation of yes-associated protein 1 (YAP1) and consequential dysregulation of MQC within renal tubule cells among DKD subjects through bioinformatic analysis of transcriptomics data from the Gene Expression Omnibus (GEO) dataset. Receiver operating characteristic curve analysis unequivocally underscores the robust diagnostic accuracy of YAP1 and MQC-related genes for DKD. Furthermore, we observed YAP1 inactivation, accompanied by perturbed MQC, within cultured tubule cells exposed to high glucose (HG) and palmitic acid (PA). This pattern was also evident in the tubulointerstitial compartment of kidney sections from biopsy-approved DKD patients. Additionally, renal tubule cell-specific Yap1 deletion exacerbated kidney injury in diabetic mice. Mechanistically, Yap1 deletion disrupted MQC, leading to mitochondrial aberrations in mitobiogenesis and mitophagy within tubule cells, ultimately culminating in histologic tubular injury. Notably, Yap1 deletion-induced renal tubule injury promoted the secretion of C-X-C motif chemokine ligand 1 (CXCL1), potentially augmenting M1 macrophage infiltration within the renal microenvironment. These multifaceted events were significantly ameliorated by administrating the YAP1 activator XMU-MP-1 in DKD mice. Consistently, bioinformatic analysis of transcriptomics data from the GEO dataset revealed a noteworthy upregulation of tubule cells-derived chemokine CXCL1 associated with macrophage infiltration among DKD patients. Crucially, overexpression of YAP1 via adenovirus transfection sustained mitochondrial membrane potential, mtDNA copy number, oxygen consumption rate, and activity of mitochondrial respiratory chain complex, but attenuated mitochondrial ROS production, thereby maintaining MQC and subsequently suppressing CXCL1 generation within cultured tubule cells exposed to HG and PA. Collectively, our study establishes a pivotal role of tubule YAP1 inactivation-mediated MQC dysfunction in driving DKD progression, at least in part, facilitated by promoting M1 macrophage polarization through a paracrine-dependent mechanism.

PLOD2 exacerbates cervical squamous cell carcinoma by suppressing p53 by binding to YAP1.

Procollagen‑lysine, 2‑oxoglutarate 5‑dioxygenase 2 (PLOD2) has been identified as an oncogene involved in the progression of several human cancers. However, its role in cervical squamous cell carcinoma (CESC) and its underlying mechanisms are not well understood. In the present study, several public databases, RT‑qPCR and western blotting were employed to detect the expression of PLOD2 and the prognosis in CESC. Cell counting kit‑8 assay, wound healing assay, Transwell assay, western blotting and flow cytometry were utilized to assess the proliferation, migration and cell apoptosis of CESC cells. Cellular senescence was examined by RT‑qPCR and β‑galactosidase staining. Prediction of PLOD2 binding to Yes‑associated protein 1 (YAP1) was assessed using BioGrid, HDock and co‑immunoprecipitation, and p53 and p21 signaling were assessed using immunofluorescence staining. The findings indicated that the expression of PLOD2 was elevated in CESC tissues and cell lines, and PLOD2 silencing caused the inhibition of CESC cell proliferation, migration and the promotion of apoptosis and senescence of CESC cells. PLOD2 was predicted to be bound to YAP1 and YAP1 overexpression reversed the effects of PLOD2 silencing on CESC cell proliferation, cell migration, apoptosis and senescence. In addition, PLOD2 facilitated CESC progression by regulating the P53 pathway through YAP1. PLOD2 exerted pro‑oncogenic effects on CESC through the p53 pathway by binding to YAP1. These findings provide new perspectives for the future study of PLOD2‑targeted therapy for CESC.

A role for YAP/FOXM1/Nrf2 axis in oxidative stress and apoptosis of cataract induced by UVB irradiation.

This study aims to investigate the hypothesis that Yes-associated protein (YAP) significantly regulates antioxidant potential and anti-apoptosis in UVB-induced cataract by exploring the underlying molecular mechanisms. To investigate the association between YAP and cataract, various experimental techniques were employed, including cell viability assessment, Annexin V FITC/PI assay, measurement of ROS production, RT-PCR, Western blot assay, and Immunoprecipitation. UVB exposure on human lens epithelium cells (HLECs) reduced total and nuclear YAP protein expression, increased cleaved/pro-caspase 3 ratios, decreased cell viability, and elevated ROS levels compared to controls. Similar Western blot results were observed in invivo experiments involving UVB-treated mice. YAP knockdown invitro demonstrated a decrease in the protein expression of FOXM1, Nrf2, and HO-1, which correlated with the mRNA expression, accompanied by an increase in cell apoptosis, caspase 3 activation, and the release of ROS. Conversely, YAP overexpression mitigated these effects induced by UVB irradiation. Immunoprecipitation revealed a FOXM1-YAP interaction. Notably, inhibiting FOXM1 decreased Nrf2 and HO-1, activating caspase 3. Additionally, administering the ROS inhibitor N-acetyl-L-cysteine (NAC) effectively mitigated the apoptotic effects induced by oxidative stress from UVB irradiation, rescuing the protein expression levels of YAP, FOXM1, Nrf2, and HO-1. The initial findings of our study demonstrate the existence of a feedback loop involving YAP, FOXM1, Nrf2, and ROS that significantly influences the cell apoptosis in HLECs under UVB-induced oxidative stress.

Knockout of C1q/tumor necrosis factor-related protein-9 aggravates cardiac fibrosis in diabetic mice by regulating YAP-mediated autophagy.

Diabetic cardiomyopathy (DCM) is predominantly distinguished by impairment in ventricular function and myocardial fibrosis. Previous studies revealed the cardioprotective properties of C1q/tumor necrosis factor-related protein 9 (CTRP9). However, whether CTRP9 affects diabetic myocardial fibrosis and its underlying mechanisms remains unclear. We developed a type 1 diabetes (T1DM) model in CTRP9-KO mice via streptozotocin (STZ) induction to examine cardiac function, histopathology, fibrosis extent, Yes-associated protein (YAP) expression, and the expression of markers for autophagy such LC3-II and p62. Additionally, we analyzed the direct impact of CTRP9 on high glucose (HG)-induced transdifferentiation, autophagic activity, and YAP protein levels in cardiac fibroblasts. In diabetic mice, CTRP9 expression was decreased in the heart. The absence of CTRP9 aggravated cardiac dysfunction and fibrosis in mice with diabetes, alongside increased YAP expression and impaired autophagy. In vitro, HG induced the activation of myocardial fibroblasts, which demonstrated elevated cell proliferation, collagen production, and α-smooth muscle actin (α-SMA) expression. CTRP9 countered these adverse effects by restoring autophagy and reducing YAP protein levels in cardiac fibroblasts. Notably, the protective effects of CTRP9 were negated by the inhibition of autophagy with chloroquine (CQ) or by YAP overexpression through plasmid intervention. Notably, the protective effect of CTRP9 was negated by inhibition of autophagy caused by chloroquine (CQ) or plasmid intervention with YAP overexpression. Our findings suggest that CTRP9 can enhance cardiac function and mitigate cardiac remodeling in DCM through the regulation of YAP-mediated autophagy. CTRP9 holds promise as a potential candidate for pharmacotherapy in managing diabetic cardiac fibrosis.

A highly selective inhibitor of discoidin domain receptor-1 (DDR1-IN-1) protects corneal epithelial cells from YAP/ACSL4-mediated ferroptosis in dry eye.

This study investigated the involvement of discoidin domain receptor (DDR) in dry eye and assessed the potential of specific DDR inhibitors as a therapeutic strategy for dry eye by exploring the underlying mechanism. Dry eye was induced in Wistar rats by applying 0.2% benzalkonium chloride (BAC), after which rats were treated topically for 7 days with DDR1-IN-1, a selective inhibitor of DDR1. Clinical manifestations of dry eye were assessed on Day-7 post-treatment. Histological evaluation of corneal damage was performed using haematoxylin and eosin (H&E) staining. In vitro, immortalized human corneal epithelial cells (HCECs) exposed to hyperosmotic stress (HS) were treated with varying doses of DDR1-IN-1 for 24 h. The levels of lipid peroxidation in dry eye corneas or HS-stimulated HCECs were assessed. Protein levels of DDR1/DDR2 and related pathways were detected by western blotting. The cellular distribution of acyl-CoA synthetase long chain family member 4 (ACSL4) and Yes-associated protein (YAP) was evaluated using immunohistochemistry or immunofluorescent staining. In dry eye corneas, only DDR1 expression was significantly up-regulated compared with normal controls. DDR1-IN-1 treatment significantly alleviated dry eye symptoms in vivo. The treatment remarkably reduced lipid hydroperoxide (LPO) levels and suppressed the expression of ferroptosis markers, particularly ACSL4. Overexpression or reactivation of YAP diminished the protective effects of DDR1-IN-1, indicating the involvement of the Hippo/YAP pathway in DDR1-targeted therapeutic effects. This study confirms the significance of DDR1 in dry eye and highlights the potential of selective DDR1 inhibitor(s) for dry eye treatment.

Suppression of YAP Ameliorates Cartilage Degeneration in Ankle Osteoarthritis via Modulation of the Wnt/β-Catenin Signaling Pathway.

Ankle osteoarthritis is a relatively understudied condition and the molecular mechanisms involved in its development are not well understood. This investigation aimed to explore the role and underlying molecular mechanisms of Yes-associated protein (YAP) in rat ankle osteoarthritis. The results demonstrated that YAP expression levels were abnormally increased in the ankle osteoarthritis cartilage model. In addition, knockdown of YAP expression was shown to hinder the imbalance in ECM metabolism induced by IL-1β in chondrocytes, as demonstrated by the regulation of matrix metalloproteinase (MMP)-3, MMP-9, and MMP-13, a disintegrin, metalloprotease with thrombospondin motifs, aggrecan, and collagen II expression. Additional studies revealed that downregulation of YAP expression markedly inhibited the overexpression of β-catenin stimulated by IL-1β. Furthermore, inhibition of the Wnt/β-catenin signaling pathway reversed the ECM metabolism imbalance caused by YAP overexpression in chondrocytes. It is important to note that the YAP-specific inhibitor verteporfin (VP) significantly delayed the progression of ankle osteoarthritis. In conclusion, the findings highlighted the crucial role of YAP as a regulator in modulating the progression of ankle osteoarthritis via the Wnt/β-catenin signaling pathway. These findings suggest that pharmacological inhibition of YAP can be an effective and critical therapeutic target for alleviating ankle osteoarthritis.

YAP1 inhibits the senescence of alveolar epithelial cells by targeting Prdx3 to alleviate pulmonary fibrosis

The senescence of alveolar type II (AT2) cells impedes self-repair of the lung epithelium and contributes to lung injury in the setting of idiopathic pulmonary fibrosis (IPF). Yes-associated protein 1 (YAP1) is essential for cell growth and organ development; however, the role of YAP1 in AT2 cells during pulmonary fibrosis is still unclear. YAP1 expression was found to be downregulated in the AT2 cells of PF patients. Deletion of YAP1 in AT2 cells resulted in lung injury, exacerbated extracellular matrix (ECM) deposition, and worsened lung function. In contrast, overexpression of YAP1 in AT2 cells promoted alveolar regeneration, mitigated pulmonary fibrosis, and improved lung function. In addition, overexpression of YAP1 alleviated bleomycin (BLM) -induced senescence of alveolar epithelial cells both in vivo and in vitro. Moreover, YAP1 promoted the expression of peroxiredoxin 3 (Prdx3) by directly interacting with TEAD1. Forced expression of Prdx3 inhibited senescence and improved mitochondrial dysfunction in BLM-treated MLE-12 cells, whereas depletion of Prdx3 partially abrogated the protective effect of YAP1. Furthermore, overexpression of Prdx3 facilitated self-repair of the injured lung and reduced ECM deposition, while silencing Prdx3 attenuated the antifibrotic effect of YAP1. In conclusion, this study demonstrated that YAP1 alleviates lung injury and pulmonary fibrosis by regulating Prdx3 expression to improve mitochondrial dysfunction and block senescence in AT2 cells, revealing a potential novel therapeutic strategy for pulmonary fibrosis.

YAP prevents senescence of dermal fibroblast and inhibits melanogenesis via paracrine effect of DKK1.

Senile skin hyperpigmentation displays remarkable histopathological features of dermal aging. The crosstalk between melanocytes and dermal fibroblasts plays crucial roles in aging-related pigmentation. While senescent fibroblasts can upregulate pro-melanogenic factors, the role of anti-melanogenic factors, such as dickkopf1 (DKK1), and the upstream regulatory mechanism during aging remain obscure. This study investigated the roles of yes-associated protein (YAP) and DKK1 in the regulation of dermal fibroblast senescence and melanogenesis. Our findings demonstrated decreased YAP activity and DKK1 levels in intrinsic and extrinsic senescent fibroblasts. YAP depletion induced fibroblast senescence and downregulated the expression and secretion of DKK1, whereas YAP overexpression partially reversed the effect. The transcriptional regulation of DKK1 by YAP was supported by dual-luciferase reporter and chromatin immunoprecipitation assays. Moreover, YAP depletion in fibroblasts upregulated Wnt/β-catenin in melanocytes and stimulated melanogenesis, which was partially rescued by the re-supplementation of DKK1. Conversely, overexpression of YAP in senescent fibroblasts decreased Wnt/β-catenin levels in melanocytes and inhibited melanogenesis. Additionally, reduced levels of YAP and DKK1 were verified in the dermis of solar lentigines. These findings suggest that, during skin aging, epidermal pigmentation may be influenced by YAP in the dermal microenvironment via the paracrine effect of DKK1.

Inhibition of Connective Tissue Growth Factor Expression in Adult Retinal Pigment Epithelial-19 Cells by Blocking Yes-Associated Protein/Transcriptional Coactivator with PDZ-Binding Motif Activity.

Purpose: To investigate the effect of yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) on connective tissue growth factor (CTGF) expression in adult retinal pigment epithelial (ARPE)-19 cells. We also studied the inhibitory effect of K-975, a new pan-transcriptional enhanced associate domain (TEAD) inhibitor, and luteolin, a plant-derived flavonoid on CTGF expression. Methods: ARPE-19 cells were transfected with either YAP or TAZ overexpression plasmid or treated with transforming growth factor (TGF)-β2. The cells were cultured either with or without K-975 or luteolin. The expression of YAP, TAZ, and CTGF was examined using real-time PCR. Results: ARPE-19 cells overexpressing YAP or TAZ exhibited significantly increased CTGF expression. This increase was attenuated by K-975 or luteolin alone. TGF-β2 treatment significantly raised the expression of not just YAP and TAZ, but also CTGF in ARPE-19 cells. TGF-β2 treatment-enhanced CTGF expression was considerably lowered by the addition of K-975 or luteolin. Conclusions: Overexpression of YAP or TAZ and treatment with TGF-β2 led to an increase in the expression of CTGF in ARPE-19 cells. These increases were attenuated by treatment with K-975 and luteolin. These findings suggest that YAP and TAZ may be related to the expression of CTGF in ARPE-19 cells and that K-975 and luteolin can be explored as potential therapeutic agents for preventing CTGF production in vitreoretinal fibrosis.

ENO1 contributes to the gemcitabine resistance of pancreatic cancer through the YAP1 signaling pathway.

Pancreatic cancer (PC), a leading cause of cancer-related deaths, has a 5-year survival rate of approximately 10%. α-Enolase (ENO1) is a junction channel protein involved in tumor cell apoptosis and chemoresistance. However, the role of ENO1 in PC remains unclear. The expression and prognosis of ENO1 levels were determined in PC using public databases based on The Cancer Genome Atlas (TCGA) data sets. Cell viability, half maximal inhibitory concentration (IC50), autophagy, apoptosis, and autophagy markers were examined using cell counting kit-8 (CCK-8), transmission electron microscope, flow cytometry assays, and immunoblot, respectively. Using the Gene Expression Omnibus (GEO) and TCGA data sets, we found that ENO1 was significantly enriched in PC tumor tissues, and high expression levels of ENO1 were associated with an unfavorable prognosis. Whereas ENO1 silencing suppressed proliferation, autophagy, and induced cell apoptosis in PC cells, and inhibited tumor growth in vivo. Mechanistically, knockdown of ENO1 enhanced cellular cytotoxicity of gemcitabine (GEM), as well as reducing the expression of yes-associated protein 1 (YAP1), a major downstream effector of the Hippo pathway in vitro. YAP1 promoted autophagy and protected PC cells from GEM-induced apoptotic cell death. Furthermore, YAP1 overexpression attenuated the inhibition effects of ENO1 silencing. Our results suggest that ENO1 overexpression promotes cell growth and tumor progression by increasing the expression of YAP1 in PC. Further studies are required to understand the detailed mechanisms between ENO1 and YAP1 in PC.

Regulation mechanism of EBV-encoded EBER1 and LMP2A on YAP1 and the impact of YAP1 on the EBV infection status in EBV-associated gastric carcinoma

This study aims to explore the role and regulatory mechanism of Yes-associated protein 1 (YAP1) in the development of Epstein-Barr virus-associated gastric cancer (EBVaGC). Here we showed that EBV can upregulate the expression and activity of YAP1 protein through its encoded latent products EBV-encoded small RNA 1 (EBER1) and latent membrane protein 2A (LMP2A), enhancing the malignant characteristics of EBVaGC cells. In addition, we also showed that overexpression of YAP1 induced the expression of EBV encoding latent and lytic phase genes and proteins in the epithelial cell line AGS-EBV infected with EBV, and increased the copy number of the EBV genome, while loss of YAP1 expression reduced the aforementioned indicators. Moreover, we found that YAP1 enhanced EBV lytic reactivation induced by two known activators, 12-O-tetradecanoylhorbol-13-acetate (TPA) and sodium butyrate (NaB). These results indicated a bidirectional regulatory mechanism between EBV and YAP1 proteins, providing new experimental evidence for further understanding the regulation of EBV infection patterns and carcinogenic mechanisms in gastric cancer.

Overexpression of YAP confers radioresistance to esophageal cancer by altering the tumor microenvironment.

This study aimed to investigate the role of yes-associated protein (YAP) in the radiotherapy sensitivity of esophageal squamous cell carcinoma (ESCC). The clonogenic ability of ESCC cells was reduced after YAP silencing and radiotherapy. Overexpression of YAP promoted cell survival and had a synergistic effect with the hypoxic microenvironment. YAP was found to directly regulate hypoxia-inducible factor 1α (HIF-1α). Bioinformatics analysis revealed the involvement of YAP in modulating the tumor immune microenvironment. Inhibition of YAP expression reduced myeloid-derived suppressor cells (MDSCs) and influenced the immunosuppressive state, leading to radio resistance. These findings provide insights into the YAP-HIF-1α interaction and support YAP as a potential target for enhancing radiotherapy sensitivity in esophageal cancer.

YAP/TAZ Signaling Enhances Angiogenesis of Retinal Microvascular Endothelial Cells in a High-Glucose Environment

Purpose Diabetic retinopathy (DR) is a major cause of irreversible blindness in the working-age population. Neovascularization is an important hallmark of advanced DR. There is evidence that Yes-associated protein (YAP)/transcriptional co-activator with a PDZ binding domain (TAZ) plays an important role in angiogenesis and that its activity is regulated by vascular endothelial growth factor (VEGF). Therefore, the aim of this study was to investigate the effect of YAP/TAZ-VEGF crosstalk on the angiogenic capacity of human retinal microvascular endothelial cells (hRECs) in a high-glucose environment. Methods The expression of YAP and TAZ of hRECs under normal conditions, hypertonic conditions and high glucose were observed. YAP overexpression (OE-YAP), YAP silencing (sh-YAP), VEGF overexpression (OE-VEGF) and VEGF silencing (sh-VEGF) plasmids were constructed. Cell counting kit-8 assay was performed to detect cells proliferation ability, transwell assay to detect cells migration ability, and tube formation assay to detect tube formation ability. The protein expression of YAP, TAZ, VEGF, matrix metalloproteinase (MMP)-8, MMP-13, vessel endothelium (VE)-cadherin and alpha smooth muscle actin (α-SMA) was measured by western blot. Results The proliferation of hRECs was significantly higher in the high glucose group compared with the normal group, as well as the protein expression of YAP and TAZ (p < 0.01). YAP and VEGF promoted the proliferation, migration and tube formation of hRECs in the high glucose environment (p < 0.01), and increased the expression of TAZ, VEGF, MMP-8, MMP-13 and α-SMA while reducing the expression of VE-cadherin (p < 0.01). Knockdown of YAP effectively reversed the above promoting effects of OE-VEGF (p < 0.01) and overexpression of YAP significantly reversed the inhibition effects of sh-VEGF on above cell function (p < 0.01). Conclusion In a high-glucose environment, YAP/TAZ can significantly promote the proliferation, migration and tube formation ability of hRECs, and the mechanism may be related to the regulation of VEGF expression.

YAP1 expression in colorectal cancer confers the aggressive phenotypes via its target genes

ABSTRACT Yes-associated protein1 (YAP1), a downstream effector of the Hippo pathway, is over-expressed in several types of malignancies. We analyzed retrospectively the TCGA database using 447 colorectal cancer (CRC) samples to determine the correlation between YAP1 expression level and CRC patient prognosis. YAP1-enforced expressed CRC cell lines were constructed using the lentivirus particles containing a YAP1 insert. YAP1 was highly expressed in CRC cancerous tissues and is associated with distant metastasis of CRC patients. Kaplan – Meier analysis indicated that CRC patients with a higher YAP1 expression group (n = 104) had worse disease-free survival (DFS) and overall survival (OS) than lower YAP1 expression group (n = 343) (p = 0.008 and p = 0.022). Univariate and multivariate analysis indicated that the elevated YAP1 expression predicted the aggressive phenotype and was an independent indicator for OS and DFS of CRC patients. YAP1 over-expression in CRC cells enhanced their migration and invasion significantly which can be reversed by AXL, CTGF, or CYR61 interference. The study suggested that YAP1 affected the prognosis of CRC patients and controlled the abilities of invasion and migration of CRC cells via its target genes AXL, CTGF, and CYR61.

Yes-Associated Protein Promotes Endothelial-Mesenchymal Transition to Mediate Diabetes Mellitus Erectile Dysfunction by Phosphorylating Smad3.

The main objective of this study is to elucidate the role of endothelial-mesenchymal transition (EndMT) regulated by yes-associated protein (YAP) on diabetes mellitus erectile dysfunction (DMED). High concentrations of glucose and palmitic acid (HGP) culturing simulated a diabetic condition in vitro. Cell proliferation, migration, tube formation, and marker gene changes of rat cavernous endothelial cells (RCECs) were measured after YAP overexpression or knockdown. Erectile function and histological outcomes were evaluated in vivo. Nuclear YAP in RCECs was significantly increased after pretreatment with HGP. YAP overexpression enhanced the cell proliferation (0.236±0.004 vs. 0.148±0.008, p<0.001), migration (1.908±0.099 vs. 1.000±0.116, p<0.001), and tube formation (290.6±10.96 and 21,440.3±762.9 vs. 175.0±24.82 and 13,538.6±1,819.0, p<0.001) compared to the control group. Moreover, the ratios of intracavernous pressure (ICP) to mean arterial pressure (MAP) (0.642±0.051 vs. 0.850±0.070, p<0.05), and smooth muscle to collagen (0.155±0.010 vs. 0.274±0.023, p<0.01) were decreased in rats with YAP overexpression. The effects of HGP on CD31, eNOS, CD34, VE-cadherin, vimentin, α-SMA, and p-Smad3 expression were abrogated by inhibiting YAP in RCECs. YAP knockdown also restored the ICP/MAP (0.597±0.019 vs. 0.346±0.033, p<0.01), smooth muscle/collagen (0.13±0.010 vs. 0.08±0.026, p<0.05) and p-Smad3/Smad3 (1.61±0.291 vs. 3.26±0.332, p<0.01) ratios in type 2 diabetic rats. YAP promotes EndMT to impair erectile function in type 2 diabetic rats by phosphorylating Smad3, providing a new strategy for treating DMED.

Circular RNA hsa_circ_0051246 acts as a microRNA-375 sponge to promote the progression of gastric cancer stem cells via YAP1.

Gastric cancer (GC) stem cells play an important role in GC progression. Circular RNAs (circRNAs) act as microRNA (miRNA) sponges and inhibit the biological function of miRNAs in GC cytoplasm. MiRNAs also participate in GC progress. circ_0051246 was shown to be associated with miR-375 after analyzing GC microarray data GSE78091 and GSE83521. The oncoprotein Yes-associated protein 1 (YAP1) is targeted by miR-375 and can be inactivated via the Hippo tumor suppressor pathway. Due to insufficient research on circ_0051246, this study aimed to investigate its relationship with miR-375 and YAP1 in cancer stem cells (CSCs). SGC-7901 CSCs were used to establish knockdown/overexpression models of circ_0051246, miR-375, and YAP1. Malignant phenotypes of CSCs were assessed using Cell Counting Kit 8, colony/sphere formation, 5-Ethynyl-2'-deoxyuridine assay, flow cytometry, Transwell, and wound healing assays. To detect the interactions between circ_0051246, miR-375, and YAP1 in CSCs, a dual-luciferase reporter assay and fluorescence in situ hybridization were performed. In addition, 24 BALB/c nude mice were used to establish orthotopic xenograft tumor models. Four groups of mice were injected with CSCs (1 × 106 cells/100 µL) with circ_0051246 knockdown, miR-375 overexpression, or their respective control cells, and tumor progression and gene expression were observed by hematoxylin-eosin staining, immunohistochemistry. Western blot and quantitative real-time PCR were utilized to examine protein and gene expression, respectively. Circ_0051246 silencing reduced viability, promoted apoptosis, and inhibited proliferation, migration and invasion of CSCs. The functional effects of miR-375 mimics were comparable to those of circ_0051246 knockdown; however, the opposite was observed after miR-375 inhibitors treatment of CSCs. Furthermore, circ_0051246-overexpression antagonized the miR-375 mimics' effects on CSCs. Additionally, YAP1 overexpression promoted CSC features, such as self-renewal, migration, and invasion, inhibited apoptosis and E-cadherin levels, and upregulated the expression of N-cadherin, vimentin, YAP1, neurogenic locus notch homolog protein 1, and jagged canonical notch ligand 1. Conversely, YAP1-silenced produced the opposite effect. Moreover, miR-375 treatment antagonized the malignant effects of YAP1 overexpression in CSCs. Importantly, circ_0051246 knockdown and miR-375 activation suppressed CSC tumorigenicity in vivo. This study highlights the promotion of circ_0051246-miR-375-YAP1 axis activation in GC progression and provides a scientific basis for research on the molecular mechanism of CSCs.

Endothelial YAP Mediates Hyperglycemia-Induced Platelet Hyperactivity and Arterial Thrombosis.

Hyperglycemia-a symptom that characterizes diabetes-is highly associated with atherothrombotic complications. However, the underlying mechanism by which hyperglycemia fuels platelet activation and arterial thrombus formation is still not fully understood. The profiles of polyunsaturated fatty acid metabolites in the plasma of patients with diabetes and healthy controls were determined with targeted metabolomics. FeCl3-induced carotid injury model was used to assess arterial thrombus formation in mice with endothelial cell (EC)-specific YAP (yes-associated protein) deletion or overexpression. Flow cytometry and clot retraction assay were used to evaluate platelet activation. RNA sequencing and multiple biochemical analyses were conducted to unravel the underlying mechanism. The plasma PGE2 (prostaglandin E2) concentration was elevated in patients with diabetes with thrombotic complications and positively correlated with platelet activation. The PGE2 synthetases COX-2 (cyclooxygenase-2) and mPGES-1 (microsomal prostaglandin E synthase-1) were found to be highly expressed in ECs but not in other type of vessel cells in arteries from both patients with diabetes and hyperglycemic mice, compared with nondiabetic individuals and control mice, respectively. A combination of RNA sequencing and ingenuity pathway analyses indicated the involvement of YAP signaling. EC-specific deletion of YAP limited platelet activation and arterial thrombosis in hyperglycemic mice, whereas EC-specific overexpression of YAP in mice mimicked the prothrombotic state of diabetes, without affecting hemostasis. Mechanistically, we found that hyperglycemia/high glucose-induced endothelial YAP nuclear translocation and subsequently transcriptional expression of COX-2 and mPGES-1 contributed to the elevation of PGE2 and platelet activation. Blockade of EP3 (prostaglandin E receptor 3) activation by oral administration of DG-041 reversed the hyperactivity of platelets and delayed thrombus formation in both EC-specific YAP-overexpressing and hyperglycemic mice. Collectively, our data suggest that hyperglycemia-induced endothelial YAP activation aggravates platelet activation and arterial thrombus formation via PGE2/EP3 signaling. Targeting EP3 with DG-041 might be therapeutic for diabetes-related thrombosis.

YAP Facilitates NEDD4L-Mediated Ubiquitination and Degradation of ACSL4 to Alleviate Ferroptosis in Myocardial Ischemia-Reperfusion Injury.

Ferroptosis is a novel iron-dependent type of cell death that takes part in the progression of myocardial ischemia/reperfusion injury (MIRI). However, the detailed mechanism of ferroptosis underlying MIRI remains unclear. This study aimed to investigate the regulatory role of yes-associated protein (YAP) in ferroptosis during MIRI. The invivo and invitro MIRI models were established in the Sprague-Dawley (SD) rats and H9C2 cardiomyocytes. The infarct volume, pathologic changes, cardiac function, serum levels of lactate dehydrogenase (LDH) and creatine kinase (CK)-MB were detected. Western blotting and immunohistochemistry were performed to measure the expression of YAP, neural precursor cell expressed developmentally downregulated 4-like (NEDD4L) and ferroptosis-related proteins. Ferroptosis was evaluated by Fe2+, malondialdehyde (MDA), LDH, glutathione (GSH), and lipid reactive oxygen species (ROS) levels. Molecular mechanism was analyzed by co-immunoprecipitation (Co-IP), chromatin immunoprecipitation (ChIP), and dual-luciferase reporter assay. YAP and NEDD4L were remarkably low expressed in MIRI models. YAP overexpression reduced myocardial infarct volume and improved cardiac function. In addition, YAP inhibited MIRI-induced ferroptosis as confirmed by reducing levels of Fe2+, MDA, LDH, lipid ROS, and ferroptosis-related protein ACSL4, and enhancing GSH level and cell viability. Mechanistically, YAP facilitated NEDD4L transcription that consequently caused ubiquitination and degradation of ACSL4, thereby restraining ferroptosis in MIRI. YAP knockdown aggravated MIRI-induced ferroptosis, which was counteracted by NEDD4L overexpression. YAP represses MIRI-induced cardiomyocyte ferroptosis via promoting NEDD4L transcription and subsequent ubiquitination and degradation of ACSL4. YAP-mediated ferroptosis inhibition might be a novel therapeutic strategy for MIRI.

Verteporfin Suppresses YAP-Induced Glycolysis in Breast Cancer Cells

Objective The inhibition of the Hippo pathway through targeting the Yes-associated protein (YAP) presents a novel and promising approach for treating tumors. However, the efficacy of YAP inhibitors in the context of breast cancer (BC) remains incompletely understood. Here, we aimed to investigate the involvement of YAP in BC's metabolic reprogramming and reveal the potential underlying mechanisms. To this end, we assessed the function of verteporfin (VP), a YAP-TEAD complex inhibitor, on the glycolytic activity of BC cells. Methods We evaluated the expression of YAP by utilizing immunohistochemistry (IHC) in BC patients who have undergone 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) prior to biopsy/surgery. We employed RNA immunoprecipitation (RIP) and fluorescent in situ hybridization (FISH) assays to assess the interaction between YAP mRNA and human antigen R (HuR) in BC cells. The biological importance of YAP in the metabolism and malignancy of BC was evaluated in vitro. Finally, the effect of VP on glycolysis was determined by using 18F-FDG uptake, glucose consumption, and lactate production assays. Results Our studies revealed that high expression of YAP was positively correlated with the maximum uptake value (SUVmax) determined by 18F-FDG PET/CT imaging in BC samples. Inhibition of YAP activity suppressed glycolysis in BC. The mechanism underlying this phenomenon could be the binding of YAP to HuR, which promotes glycolysis in BC cells. Treatment with VP effectively suppressed glycolysis induced by YAP overexpression in BC cells. Conclusion VP exhibited anti-glycolytic effect on BC cells, indicating its therapeutic value as an FDA-approved drug.