17ß-Estradiol, through activating the G protein-coupled estrogen receptor, exacerbates the complication of benign prostatic hyperplasia in type 2 diabetes mellitus patients by inducing prostate proliferation.

Benign prostatic hyperplasia (BPH) is one of the major chronic complications of type 2 diabetes mellitus (T2DM), and sex steroid hormones are common risk factors for the occurrence of T2DM and BPH. The profiles of sex steroid hormones are simultaneously quantified by LC-MS/MS in the clinical serum of patients, including simple BPH patients, newly diagnosed T2DM patients, T2DM complicated with BPH patients and matched healthy individuals. The G protein-coupled estrogen receptor (GPER) inhibitor G15, GPER knockdown lentivirus, the YAP1 inhibitor verteporfin, YAP1 knockdown/overexpression lentivirus, targeted metabolomics analysis, and Co-IP assays are used to investigate the molecular mechanisms of the disrupted sex steroid hormones homeostasis in the pathological process of T2DM complicated with BPH. The homeostasis of sex steroid hormone is disrupted in the serum of patients, accompanying with the proliferated prostatic epithelial cells (PECs). The sex steroid hormone metabolic profiles of T2DM patients complicated with BPH have the greatest degrees of separation from those of healthy individuals. Elevated 17ß-estradiol (E2) is the key contributor to the disrupted sex steroid hormone homeostasis, and is significantly positively related to the clinical characteristics of T2DM patients complicated with BPH. Activating GPER by E2 via Hippo-YAP1 signaling exacerbates high glucose (HG)-induced PECs proliferation through the formation of the YAP1-TEAD4 heterodimer. Knockdown or inhibition of GPER-mediated Hippo-YAP1 signaling suppresses PECs proliferation in HG and E2 co-treated BPH-1 cells. The anti-proliferative effects of verteporfin, an inhibitor of YAP1, are blocked by YAP1 overexpression in HG and E2 co-treated BPH-1 cells. Inactivating E2/GPER/Hippo/YAP1 signaling may be effective at delaying the progression of T2DM complicated with BPH by inhibiting PECs proliferation.

Exploring the significance and potential mechanisms of hippo pathway-associated genes in prognosis of glioma patients.

PURPOSE: Despite the efforts of countless researchers to develop glioma treatment strategies, the current therapeutic effect of glioma is still not ideal, and it is necessary to further explore the mechanism to guide treatment. Thus, this study aims to introduce a novel approach for predicting patient prognosis and guiding further treatment interventions. METHODS: Initially, we conducted a differential gene expression analysis to identify Hippo pathway-associated genes overexpressed in tumors and determined genes correlated with prognosis. Subsequently, employing cluster analysis, we categorized samples into two groups and performed further analyses including prediction, immune cell infiltration abundance, and drug response rates. We utilized weighted gene co-expression analysis to reveal gene sets with high co-variation, delineate inter-sample gene correlation patterns, and conduct enrichment analysis. Prognostic models were built using ten machine learning algorithms combined in 101 different combinations, followed by evaluation and validation. Immune infiltration analysis, differential expression analysis of depleted T cell-related markers, drug sensitivity analysis, and exploration of pathway dysregulation were performed for different risk groups. Quality control and batch integration were performed, and single-cell data were analyzed using dimensionality reduction clustering algorithms and annotation tools to evaluate the activity of the prognostic model in malignant cells. RESULTS: We conducted data filtering to identify genes overexpressed in tumors, intersecting these genes with Hippo pathway-related genes, identifying 62 genes correlated with prognosis, and performing cluster analysis to divide tumor tissues into two groups. Cluster 2 exhibited a poorer prognosis and demonstrated differences in immune cell infiltration. Utilizing weighted gene co-expression analysis on Cluster 2, we identified gene modules, conducted functional enrichment analysis, and delineated pathways. Employing a combined model based on ten machine learning algorithm combinations, we selected the optimal prognostic model system and validated the model's predictive ability within the dataset. Through immune-related analysis and drug sensitivity analysis, we uncovered differences in immune infiltration and varying sensitivities to chemotherapy drugs. Additionally, the enrichment analysis of gene set revealed discrepancies in upregulation within relevant pathways between the high and low-risk groups. Finally, annotation and evaluation of malignant cells via single-cell analysis showed increased activity of the prognostic model and variations in distribution across different prognostic levels in malignant cells. CONCLUSION: This study introduces a novel approach utilizing the Hippo pathway and associated genes for glioma prognosis research, demonstrating the potential and significance of this method in evaluating the outcome for patients with glioma. These findings hold substantial clinical significance in guiding therapy and predicting outcomes for individuals diagnosed with glioma, offering significant clinical utility.

Targeting the Hippo pathway in Schwann cells ameliorates peripheral nerve degeneration via a polypharmacological mechanism.

Peripheral neuropathies (PNs) are common diseases in elderly individuals characterized by Schwann cell (SC) dysfunction and irreversible Wallerian degeneration (WD). Although the molecular mechanisms of PN onset and progression have been widely studied, therapeutic opportunities remain limited. In this study, we investigated the pharmacological inhibition of Mammalian Ste20-like kinase 1/2 (MST1/2) by using its chemical inhibitor, XMU-MP-1 (XMU), against WD. XMU treatment suppressed the proliferation, dedifferentiation, and demyelination of SCs in models of WD in vitro, in vivo, and ex vivo. As a downstream mediator of canonical and noncanonical Hippo/MST1 pathway activation, the mature microRNA (miRNA) let-7b and its binding partners quaking homolog (QKI)/nucleolin (NCL) modulated miRNA-mediated silencing of genes involved in protein transport. Hence, direct phosphorylation of QKI and NCL by MST1 might be critical for WD onset and pathogenesis. Moreover, p38α/mitogen-activated protein kinase 14 (p38α) showed a strong affinity for XMU, and therefore, it may be an alternative XMU target for controlling WD in SCs. Taken together, our findings provide new insights into the Hippo/MST pathway function in PNs and suggest that XMU is a novel multitargeted therapeutic for elderly individuals with PNs.

Targeting Canonical Wnt-signaling Through GSK-3ß in Arrhythmogenic Cardiomyopathy: Conservative or Progressive?

Arrhythmogenic cardiomyopathy is a primary myocardial disease and a major cause of sudden death in all populations of the world. Canonical Wnt signalling is a critical pathway controlling numerous processes including cellular differentiation, hypertrophy and development. GSK3ß is a ubiquitous serine/threonine kinase, which acts downstream of Wnt to promote protein ubiquitination and proteasomal degradation. Several studies now suggest that inhibiting GSK3ß can prevent and reverse key pathognomonic features of ACM in a range of experimental models. However, varying concerns are reported throughout the literature including the risk of paradoxical arrhythmias, cancer and off-target effects in upstream or downstream pathways. CLINICAL RELEVANCE: In light of the start of the phase 2 TaRGET clinical trial, designed to evaluate the potential therapeutic efficacy of GSK3ß inhibition in patients with arrhythmogenic cardiomyopathy, this report aims to review the advantages and disadvantages of this strategy.

PRMT1-mediated arginine methylation promotes YAP activation and hepatocellular carcinoma proliferation.

The activity of Hippo signaling is commonly dysregulated in various human malignancies, including hepatocellular carcinoma (HCC). YAP, the key effector of Hippo pathway, is regulated through several posttranslational modifications. However, the mechanism by which YAP is regulated by arginine methylation remains unknown. In this study, immunoprecipitation and mass spectrometry were used to identify the arginine methylation site of YAP in HCC cells. The transcriptional activity of YAP and TEAD were further characterized by real-time qPCR and immunofluorescence assay, and a subcutaneous and orthotopic tumor mouse model was used to assess the effect of PRMT1-knockdown on HCC tumor growth. The result of mass spectrometry analysis identified that YAP was methylated at arginine 124. Moreover, we found that arginine methyltransferase PRMT1 interacted with YAP to mediate its arginine methylation, thus inhibited YAP phosphorylation and promoted YAP activity in the nucleus. PRMT1 was up-regulated in HCC tissues and positively associated with the expressions of YAP target genes. Silencing PRMT1 in HCC cells inhibited cell proliferation and tumor growth, while PRMT1-overexpression promoted HCC growth through YAP methylation. Our study reveals that PRMT1-mediated arginine methylation at R124 is mutually exclusive with YAP S127 phosphorylation, thereby facilitating YAP activity in the nucleus and promoting tumorigenesis in HCC.

Gene therapy for diffuse pleural mesotheliomas in preclinical models by concurrent expression of NF2 and SuperHippo.

Diffuse pleural mesothelioma (DPM) is a lethal cancer with a poor prognosis and limited treatment options. The Hippo signaling pathway genes, such as NF2 and LATS1/2, are frequently mutated in DPM, indicating a tumor suppressor role in the development of DPM. Here, we show that in DPM cell lines lacking NF2 and in mice with a conditional Nf2 knockout, downregulation of WWC proteins, another family of Hippo pathway regulators, accelerates DPM progression. Conversely, the expression of SuperHippo, a WWC-derived minigene, effectively enhances Hippo signaling and suppresses DPM development. Moreover, the adeno-associated virus serotype 6 (AAV6) has been engineered to deliver both NF2 and SuperHippo genes into mesothelial cells, which substantially impedes tumor growth in xenograft and genetic DPM models and prolongs the median survival of mice. These findings serve as a proof of concept for the potential use of gene therapy targeting the Hippo pathway to treat DPM.

Discovery of reversible and covalent TEAD 1 selective inhibitors MSC-1254 and MSC-5046 based on one scaffold.

The Transcriptional Enhanced Associated Domain (TEAD) family of transcription factors are key components of the Hippo signalling family which play a crucial role in the regulation of cell proliferation, differentiation and apoptosis. The identification of inhibitors of the TEAD transcription factors are an attractive strategy for the development of novel anticancer therapies. A HTS campaign identified hit 1, which was optimised using structure-based drug design, to deliver potent TEAD1 selective inhibitors with both a reversible and covalent mode of inhibition. The preference for TEAD1 could be rationalised by steric differences observed in the lower pocket of the palmitoylation-site between subtypes, with TEAD1 having the largest available volume to accommodate substitution in this region.

ASIC1a regulates ferroptosis in hepatic stellate cells via the Hippo/Yap-1 pathway in liver fibrosis.

BACKGROUND: Liver fibrosis is a sustained process of liver tissue damage and repair caused by various physiological and pathological factors, with the activation and proliferation of hepatic stellate cells being central. Therefore, understanding and clarifying the relevant mechanisms of hepatic stellate cell activation and death is of great clinical significance for the treatment of liver fibrosis diseases. METHODS: In vivo, recombinant adeno-associated virus was used to infect the liver of experimental mice, overexpressing ASIC1a, and based on this, a liver fibrosis model treated with sorafenib was constructed. In vitro, using RNA plasmid technology to transfect HSC-T6 cells, ASIC1a was overexpressed or silenced in the cells, and on this basis, PDGF-BB and Sorafenib were used to stimulate HSC-T6 cells, causing activated HSC-T6 to undergo ferroptosis. RESULTS: The ferroptosis inducers Sorafenib and erastin can induce ferroptosis in HSCs, effectively inhibiting or reversing the progression of liver fibrosis. We found that the expression level of ASIC1a was significantly reduced in the livers of mice with liver fibrosis treated with Sorafenib. After treatment with an adeno-associated virus overexpressing ASIC1a, the therapeutic effect of Sorafenib was inhibited, and the level of ferroptosis induced by Sorafenib was also inhibited. The induction of ferroptosis in hepatic stellate cells in vitro depends on the presence of ASIC1a. By further exploring the potential mechanism, we observed that the overexpression of ASIC1a can promote an increase in YAP nuclear translocation, thereby regulating the activity of Hippo/YAP pathway signaling. After treatment with Sorafenib, the influx of Ca2+ significantly increased when ASIC1a was overexpressed, and BAPTA-AM intervention eliminated the intracellular Ca2+ accumulation induced by ASIC1a overexpression. CONCLUSIONS: This indicated that the activation of YAP depends on the calcium ion influx induced by ASIC1a, which regulates ferroptosis in hepatic stellate cells by regulating the calcium ion-dependent Hippo/YAP pathway.

The Multifaceted Roles of Hippo-YAP in Cardiovascular Diseases.

The Hippo-yes-associated protein (YAP) signaling pathway plays a crucial role in cell proliferation, differentiation, and death. It is known to have impact on the progression and development of cardiovascular diseases (CVDs) as well as in the regeneration of cardiomyocytes (CMs). However, further research is needed to understand the molecular mechanisms by which the Hippo-YAP pathway affects the pathological processes of CVDs in order to evaluate its potential clinical applications. In this review, we have summarized the recent findings on the role of the Hippo-YAP pathway in CVDs such as myocardial infarction, heart failure, and cardiomyopathy, as well as its in CM development. This review calls attention to the potential roles of the Hippo-YAP pathway as a relevant target for the future treatment of CVDs.

Angiomotin cleavage promotes leader formation and collective cell migration.

Collective cell migration (CCM) is involved in multiple biological processes, including embryonic morphogenesis, angiogenesis, and cancer invasion. However, the molecular mechanisms underlying CCM, especially leader cell formation, are poorly understood. Here, we show that a signaling pathway regulating angiomotin (AMOT) cleavage plays a role in CCM, using mammalian epithelial cells and mouse models. In a confluent epithelial monolayer, full-length AMOT localizes at cell-cell junctions and limits cell motility. After cleavage, the C-terminal fragment of AMOT (AMOT-CT) translocates to the cell-matrix interface to promote the maturation of focal adhesions (FAs), generate traction force, and induce leader cell formation. Meanwhile, decreased full-length AMOT at cell-cell junctions leads to tissue fluidization and coherent migration of cell collectives. Hence, the cleavage of AMOT serves as a molecular switch to generate polarized contraction, promoting leader cell formation and CCM.

YAP Overcomes Mechanical Barriers to Induce Mitotic Rounding and Adult Cardiomyocyte Division.

BACKGROUND: Many specialized cells in adult organs acquire a state of cell cycle arrest and quiescence through unknown mechanisms. Our limited understanding of mammalian cell cycle arrest is derived primarily from cell culture models. Adult mammalian cardiomyocytes, a classic example of cell cycle arrested cells, exit the cell cycle postnatally and remain in an arrested state for the life of the organism. Cardiomyocytes can be induced to re-enter the cell cycle by YAP5SA, an active form of the Hippo signaling pathway effector YAP. METHODS: We performed clonal analyses to determine the cell kinetics of YAP5SA cardiomyocytes. We also performed single-cell RNA sequencing, marker gene analysis, and functional studies to examine how YAP5SA cardiomyocytes progress through the cell cycle. RESULTS: We discovered that YAP5SA-expressing cardiomyocytes divided efficiently, with >20% of YAP5SA cardiomyocyte clones containing ≥2 cardiomyocytes. YAP5SA cardiomyocytes re-entered cell cycle at the G1/S transition and had an S phase lasting ≈48 hours. Sarcomere disassembly is required for cardiomyocyte progression from S to G2 phase and the induction of mitotic rounding. Although oscillatory Cdk expression was induced in YAP5SA cardiomyocytes, these cells inefficiently progressed through G2 phase. This is improved by inhibiting P21 function, implicating checkpoint activity as an additional barrier to YAP5SA-induced cardiomyocyte division. CONCLUSIONS: Our data reveal that YAP5SA overcomes the mechanically constrained myocardial microenvironment to induce mitotic rounding with cardiomyocyte division, thus providing new insights into the in vivo mechanisms that maintain cell cycle quiescence in adult mammals.

Aggressive high-grade NF2 mutant meningiomas downregulate oncogenic YAP signaling via the upregulation of VGLL4 and FAT3/4.

Background: Meningiomas are the most common primary central nervous system tumors in adults. Although generally benign, a subset is of higher grade and ultimately fatal. Around half of all meningiomas harbor inactivating mutations in NF2, leading to deregulation of oncogenic YAP1 activity. While benign NF2 mutant meningiomas exhibit few genetic events in addition to NF2 inactivation, aggressive high-grade NF2 mutant meningiomas frequently harbor a highly aberrant genome. It is unclear if NF2 mutant meningiomas of different grades are equally reliant on YAP activity. Methods: We analyzed bulk and single-cell RNA-Seq data from a large cohort of human meningiomas for the expression of YAP1 target genes and Hippo effectors as well as in vitro cell line experiments. Results: Aggressive NF2 mutant meningiomas harbor decreased expression levels of YAP1 target genes and increased expression levels of the YAP1 antagonist VGLL4 and the upstream regulators FAT3/4 compared to their benign counterparts. Decreased expression of YAP1 target genes as well as high expression of VGLL4 and FAT3/4 is significantly associated with an increased risk of recurrence. In vitro, overexpression of VGLL4 resulted in the downregulation of YAP activity in benign NF2 mutant meningioma cells, confirming the direct link between VGLL4 expression and decreased levels of YAP activity observed in aggressive NF2 mutant meningiomas. Conclusions: Our results shed new insight into the biology of benign and aggressive NF2 mutant meningiomas and may have important implications for the efficacy of therapies targeting oncogenic YAP1 activity in NF2 mutant meningiomas.

HPV-YAP1 oncogenic alliance drives malignant transformation of fallopian tube epithelial cells.

High grade serous ovarian carcinoma (HGSOC) is the most common and aggressive ovarian malignancy. Accumulating evidence indicates that HGSOC may originate from human fallopian tube epithelial cells (FTECs), although the exact pathogen(s) and/or molecular mechanism underlying the malignant transformation of FTECs is unclear. Here we show that human papillomavirus (HPV), which could reach FTECs via retrograde menstruation or sperm-carrying, interacts with the yes-associated protein 1 (YAP1) to drive the malignant transformation of FTECs. HPV prevents FTECs from natural replicative and YAP1-induced senescence, thereby promoting YAP1-induced malignant transformation of FTECs. HPV also stimulates proliferation and drives metastasis of YAP1-transformed FTECs. YAP1, in turn, stimulates the expression of the putative HPV receptors and suppresses the innate immune system to facilitate HPV acquisition. These findings provide critical clues for developing new strategies to prevent and treat HGSOC.

BMAL1 alleviates sepsis-induced AKI by inhibiting ferroptosis.

BACKGROUND: The role of BMAL1 in various diseases remains unclear, particularly its impact on sepsis-induced acute kidney injury (AKI). This study aims to investigate the role of BMAL1 in sepsis-induced AKI and its potential effects on cell ferroptosis. Initially, we assessed BMAL1 expression levels in mice treated with sepsis-induced AKI (via LPS injection) and in LPS-stimulated renal tubular epithelial cells. Subsequently, we explored the correlation between BMAL1 and ferroptosis using sequencing technology, validating our findings throughout experimental approaches. To further elucidate BMAL1's specific effects on AKI-related ferroptosis, we constructed BMAL1 overexpression models in mice and cells, analysing its impact on AKI and ferroptosis both in vivo and in vitro. Furthermore, using transcriptome sequencing technology, we identified key BMAL1-regulated genes and their associated biological pathways, validating these findings through in vivo and in vitro experiments. RESULTS: Our findings indicate decreased BMAL1 expression in sepsis-induced AKI. BMAL1 overexpression effectively mitigated renal tubular injury by reducing ferroptosis levels in renal tubular epithelial cells. Using transcriptome sequencing and ChIP-qPCR technology, we identified YAP as a target of BMAL1. The overexpression of BMAL1 significantly reduced the transcriptional activity of YAP and inhibited the Hippo signalling pathway. Treatment with the Hippo inhibitor Verteporfin (VP) reversed the BMAL1-downregulation-induced damage. Additionally, our study revealed that YAP positively regulates ACSL4 gene expression and its downstream signalling pathways. CONCLUSION: This study demonstrates that BMAL1 overexpression alleviates renal tubular epithelial cell injury and ferroptosis by inhibiting YAP expression and the Hippo pathway, thereby exerting protective effects in sepsis-induced AKI. These findings underscore the therapeutic potential of targeting BMAL1 in managing sepsis-induced AKI.

Wnt/ß-Catenin Signaling Regulates Yap/Taz Activity during Embryonic Development in Zebrafish.

Hippo-YAP/TAZ and Wnt/ß-catenin signaling pathways, by controlling proliferation, migration, cell fate, stemness, and apoptosis, are crucial regulators of development and tissue homeostasis. We employed zebrafish embryos as a model system to elucidate in living reporter organisms the crosstalk between the two signaling pathways. Co-expression analysis between the Wnt/ß-catenin Tg(7xTCF-Xla.Siam:GFP)ia4 and the Hippo-Yap/Taz Tg(Hsa.CTGF:nlsmCherry)ia49 zebrafish reporter lines revealed shared spatiotemporal expression profiles. These patterns were particularly evident in key developmental regions such as the midbrain-hindbrain boundary (MHB), epidermis, muscles, neural tube, notochord, floorplate, and otic vesicle. To investigate the relationship between the Wnt/ß-catenin pathway and Hippo-Yap/Taz signaling in vivo, we conducted a series of experiments employing both pharmacological and genetic strategies. Modulation of the Wnt/ß-catenin pathway with IWR-1, XAV939, or BIO resulted in a significant regulation of the Yap/Taz reporter signal, highlighting a clear correlation between ß-catenin and Yap/Taz activities. Furthermore, genetic perturbation of the Wnt/ß-catenin pathway, by APC inhibition or DKK1 upregulation, elicited evident and robust alteration of Yap/Taz activity. These findings revealed the intricate regulatory mechanisms underlying the crosstalk between the Wnt/ß-catenin and Hippo-Yap/Taz signaling, shedding light on their roles in orchestrating developmental processes in vivo.

Activation of Piezo1 by intracranial hypertension induced neuronal apoptosis via activating hippo pathway.

AIM: Most of the subarachnoid hemorrhage (SAH) patients experienced the symptom of severe headache caused by intracranial hypertension. Piezo1 is a mechanosensitive ion channel protein. This study aimed to investigate the effect of Piezo1 on neurons in response to intracranial hypertension. METHODS: The SAH rat model was performed by the modified endovascular perforation method. Piezo1 inhibitor GsMTx4 was administered intraperitoneally after SAH induction. To investigate the underlying mechanism, the selective Piezo1 agonist Yoda1, Piezo1 shRNA, and MY-875 were administered via intracerebroventricular injection before SAH induction. In vitro, we designed a pressurizing device to exclusively explore the effect of Piezo1 activation on primary neurons. Neurons were pretreated with Piezo1 inhibition followed by intracranial hypertension treatment, and then apoptosis-related proteins were detected. RESULTS: Piezo1 inhibition significantly attenuated neuronal apoptosis and improved the outcome of neurological deficits in rats after SAH. The Hippo pathway agonist MY-875 reversed the anti-apoptotic effects of Piezo1 knockdown. In vitro, intracranial hypertension mimicked by the pressurizing device induced Piezo1 expression, resulting in Hippo pathway activation and neuronal apoptosis. The Hippo pathway inhibitor Xmu-mp-1 attenuated Yoda1-induced neuronal apoptosis. In addition, the combination of hypertension and oxyhemoglobin treatment exacerbated neuronal apoptosis. CONCLUSIONS: Intracranial hypertension induced Piezo1 expression, neuronal apoptosis, and the Hippo pathway activation; the Hippo signaling pathway is involved in Piezo1 activation-induced neuronal apoptosis in respond to intracranial hypertension. Primary neurons treated with intracranial hypertension and oxyhemoglobin together can better characterize the circumstance of SAH in vivo, which is contributed to construct an ideal in vitro SAH model.

Wedelolactone Attenuates Liver Fibrosis and Hepatic Stellate Cell Activation by Suppressing the Hippo Pathway.

Liver fibrosis is a commonly observed pathological phenomenon that occurs during the progression of various types of chronic liver diseases. The Hippo pathway is closely associated with the pathogenesis of liver fibrosis. Previous studies have shown that wedelolactone (WED) has a significant antihepatic fibrosis effect, whereas the target and mechanism underlying WED remain elusive. In this study, we found that WED significantly alleviated liver fibrosis and injury by inhibiting the expression of Yes-associated protein (YAP) and tafazzin (TAZ). In an in vitro model, WED suppressed the activation of hepatic stellate cells (HSCs) induced by transforming growth factor (TGF-ß1), as well as the mRNA and protein expression of α-smooth muscle actin (α-SMA), YAP, and TAZ. The allosteric regulation of YAP by WED was confirmed using MD and cellular thermal shift assay. Moreover, specific knockdown or inhibition of YAP did not enhance the suppressive effect of WED on HSC activation or protein expression associated with fibrosis. These findings demonstrated that the administration of WED effectively alleviated liver fibrosis by suppressing the Hippo/YAP/TAZ pathways. In addition, YAP activity may be regulated by WED via allosteric regulation.

Bimetallic clusterzymes-loaded dendritic mesoporous silica particle regulate arthritis microenvironment via ROS scavenging and YAP1 stabilization.

Clusterzymes are synthetic enzymes exhibiting substantial catalytic activity and selectivity, which are uniquely driven by single-atom constructs. A dramatic increase in antioxidant capacity, 158 times more than natural trolox, is noted when single-atom copper is incorporated into gold-based clusterzymes to form Au24Cu1. Considering the inflammatory and mildly acidic microenvironment characteristic of osteoarthritis (OA), pH-dependent dendritic mesoporous silica nanoparticles (DMSNs) coupled with PEG have been employed as a delivery system for the spatial-temporal release of clusterzymes within active articular regions, thereby enhancing the duration of effectiveness. Nonetheless, achieving high therapeutic efficacy remains a significant challenge. Herein, we describe the construction of a Clusterzymes-DMSNs-PEG complex (CDP) which remarkably diminishes reactive oxygen species (ROS) and stabilizes the chondroprotective protein YAP by inhibiting the Hippo pathway. In the rabbit ACLT (anterior cruciate ligament transection) model, the CDP complex demonstrated inhibition of matrix metalloproteinase activity, preservation of type II collagen and aggregation protein secretion, thus prolonging the clusterzymes' protective influence on joint cartilage structure. Our research underscores the efficacy of the CDP complex in ROS-scavenging, enabled by the release of clusterzymes in response to an inflammatory and slightly acidic environment, leading to the obstruction of the Hippo pathway and downstream NF-κB signaling pathway. This study illuminates the design, composition, and use of DMSNs and clusterzymes in biomedicine, thus charting a promising course for the development of novel therapeutic strategies in alleviating OA.

Role of the Hippo-YAP/TAZ Pathway in Epithelioid Hemangioendothelioma and its Potential as a Therapeutic Target.

Epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor arising from vascular endothelial cells. This study delves into the molecular mechanisms underlying EHE, with a specific focus on the Hippo-YAP/TAZ pathway. EHE is characterized molecularly by transcriptional co-activator with a PDZ-motif (TAZ)-calmodulin binding transcription activator 1 (CAMTA1) or Yes-associated protein (YAP)-transcription factor E3 (TFE3) fusions. YAP/TAZ, a transcription co-activator, binds to transcription factors and regulates gene expression. The YAP/TAZ and its upstream Hippo pathway are involved in cell proliferation and cell contact inhibition, regulating organ size and carcinogenesis. In addition to oncogenic effects, dysfunction or gene duplication of the Hippo pathway results in a poor prognosis due to epithelial-mesenchymal transformation of epithelial cells, stem cell transformation, and increased drug resistance. Notably, the TAZ-CAMTA1 fusion is specific to EHE, and genetic alterations in the Hippo pathway other than this fusion gene are absent in EHE. The TAZ-CAMTA1 fusion is a promising therapeutic target. This review summarizes recent advances in EHE, focusing on the role of the Hippo-YAP/TAZ pathway in EHE and its potential as a therapeutic target for drug development.