The Hippo pathway in intestinal regeneration and disease

Therapeutic targeting of the NOTCH1 and neddylation pathways in T cell acute lymphoblastic leukemia

Gamma Secretase Inhibitors (GSIs) effectively block oncogenic Notch homolog-1 (NOTCH1), a characteristic feature of T cell acute lymphoblastic leukemias (T-ALL). However, their clinical application has been stalled by the induction of severe gastrointestinal toxicity resulting from the inhibition of NOTCH signaling in the gut, which translates into increased goblet cell differentiation. Genome-wide CRISPR loss-of-function screen in the colon cancer cell line LS174T identified the neddylation pathway as a main regulator of goblet cell differentiation upon NOTCH1 inhibition. Consistently, pharmacologic inhibition of the neddylation pathway with the small molecule inhibitor MLN4924, rescued GSI-induced differentiation in LS174T cells. Mechanistically, neddylation inhibition by MLN4924 increases the protein stability of Hairy and enhancer of split-1, a direct NOTCH1 transcriptional target and key regulator of absorptive and secretory cell fate decisions. Combined treatment with GSI and MLN4924 in a murine Notch1-dependent model of T-ALL led to leukemia regression and improved overall survival in the absence of gut toxicity. Overall, these results support the combined targeting of the NOTCH1 and neddylation pathways for the treatment of NOTCH1-induced T-ALL.

Nuclear receptor coactive 4-mediated ferritinophagy: a key role of heavy metals toxicity

Nuclear receptor coactive 4 (NCOA4) is a specific receptor for ferritinophagy, transporting ferritin to lysosomal degradation, releasing free iron, and excessive iron levels may lead to cellular redox imbalance, contributing to cell death, predominantly ferroptosis. NCOA4 is regulated by a variety of transcriptional, post-transcriptional, translational, and post-translational modifications. Targeted modulation of NCOA4-mediated ferritinophagy has been successfully used as a therapeutic strategy in several disease models. Recent evidences have elucidated that ferritinophagy and ferroptosis played a major role in heavy metals toxicity. In this review, we explored the regulatory mechanism of NCOA4 as the sole receptor for ferritinophagy from multiple perspectives based on previous studies. The significant role of ferritinophagy-mediated ferroptosis in heavy metals toxicity was discussed in detail, emphasizing the great potential of NCOA4 as a target for heavy metals toxicity.

The emerging role of intestinal stem cells in ulcerative colitis

Ulcerative colitis (UC) is a chronic idiopathic inflammatory disease affecting the colon and rectum. Characterized by recurrent attacks, UC is often resistant to traditional anti-inflammatory therapies, imposing significant physiological, psychological, and economic burdens on patients. In light of these challenges, innovative targeted therapies have become a new expectation for patients with UC. A crucial pathological feature of UC is the impairment of the intestinal mucosal barrier, which underlies aberrant immune responses and inflammation. Intestinal stem cells (ISCs), which differentiate into intestinal epithelial cells, play a central role in maintaining this barrier. Growing studies have proved that regulating the regeneration and differentiation of ISC is a promising approach to treating UC. Despite this progress, there is a dearth of comprehensive articles describing the role of ISCs in UC. This review focuses on the importance of ISCs in maintaining the intestinal mucosal barrier in UC and discusses the latest findings on ISC functions, markers, and their regulatory mechanisms. Key pathways involved in ISC regulation, including the Wnt, Notch, Hedgehog (HH), Hippo/Yap, and autophagy pathways, are explored in detail. Additionally, this review examines recent advances in ISC-targeted therapies for UC, such as natural or synthetic compounds, microbial preparations, traditional Chinese medicine (TCM) extracts and compounds, and transplantation therapy. This review aims to offer novel therapeutic insights and strategies for patients who have long struggled with UC.

[Research Advances in Targeting the YAP/TAZ Signaling Pathway to Improve Cancer Immunotherapy]

Despite the groundbreaking advances in cancer immunotherapy achieved by immune checkpoint inhibitors (ICIs), their efficacy remains limited by the immunosuppressive tumor microenvironment (TME). Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), key effectors of the Hippo signaling pathway, play pivotal roles in tumor immune evasion. They directly regulate the expression of immune checkpoints, mediate the formation of an immunosuppressive microenvironment, inhibit T cell function, and interact with other signaling pathways to promote immune escape. Diverse strategies targeting YAP/TAZ have been developed, including direct inhibition, modulation of upstream regulators, and suppression of downstream target genes. Preclinical studies have demonstrated that combining YAP/TAZ inhibition with ICIs significantly enhances therapeutic efficacy across various tumor models. This review summarizes recent advances in understanding the role of YAP/TAZ in immune evasion within the TME and explores the potential of targeting this pathway to improve immunotherapy outcomes. Furthermore, it discusses the translational value of combination therapies based on YAP/TAZ inhibition, providing a theoretical framework and practical guidance for the development of innovative immunotherapeutic strategies and precision medicine approaches.
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Targeting CDK4/6 suppresses colorectal cancer by destabilizing YAP1

Colorectal cancer (CRC) is among the most prevalent and deadly cancers worldwide. The Yes-associated protein 1 (YAP1) is frequently dysregulated in cancers, contributing to cancer stemness, chemoresistance, and cancer-related death. However, strategies directly targeting YAP1 have not yet been successful because of the lack of active binding pockets and unregulated toxicity. In this study, our Food and Drug Administration (FDA)-approved drug screening reveals that abemaciclib, a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, dramatically promotes the proteasome-dependent degradation of YAP1, thereby inhibiting tumor progression in CRC cells and patient-derived xenograft models. We further identify deubiquitinating enzyme 3 (DUB3) as the bona fide deubiquitinase of YAP1 in CRC. Mechanistically, CDK4/6 directly phosphorylates DUB3 at Ser41, activating DUB3 to deubiquitinate and stabilize YAP1. Conversely, loss of Ser41 phosphorylation by CDK4/6 inhibition or Ser41A mutation, promotes YAP1 degradation and suppresses YAP1-driven tumor progression. Histological analysis shows a positive correlation between DUB3 and YAP1 expression in CRC specimens. Collectively, our study uncovers a novel oncogenic role of the CDK4/6-DUB3 pathway, which promotes YAP1 stabilization and tumor-promoting function, highlighting that targeting CDK4/6 offers a potential therapeutic strategy for CRC with aberrantly upregulated DUB3 and YAP1.

The Role of Yes-Associated Protein in Inflammatory Diseases and Cancer

Yes-associated protein (YAP) plays a central role in the Hippo pathway, primarily governing cell proliferation, differentiation, and apoptosis. Its significance extends to tumorigenesis and inflammatory conditions, impacting disease initiation and progression. Given the increasing relevance of YAP in inflammatory disorders and cancer, this study aims to elucidate its pathological regulatory functions in these contexts. Specifically, we aim to investigate the involvement and molecular mechanisms of YAP in various inflammatory diseases and cancers. We particularly focus on how YAP activation, whether through Hippo-dependent or independent pathways, triggers the release of inflammation and inflammatory mediators in respiratory, cardiovascular, and digestive inflammatory conditions. In cancer, YAP not only promotes tumor cell proliferation and differentiation but also modulates the tumor immune microenvironment, thereby fostering tumor metastasis and progression. Additionally, we provide an overview of current YAP-targeted therapies. By emphasizing YAP's role in inflammatory diseases and cancer, this study aims to enhance our understanding of the protein's pivotal involvement in disease processes, elucidate the intricate pathological mechanisms of related diseases, and contribute to future drug development strategies targeting YAP.

Mesenchymal Hippo signaling regulates intestinal homeostasis in adult mice

Intestinal homeostasis is tightly regulated by the reciprocal interaction between the gut epithelium and adjacent mesenchyme. The Hippo pathway is intimately associated with intestinal epithelial homeostasis and regeneration; however, its role in postnatal gut mesenchyme remains poorly defined. Here, we find that removal of the core Hippo kinases Lats1/2 or activation of YAP in adult intestinal smooth muscle layers has largely no effect; however, Hippo-YAP signaling in the niche-forming Gli1+ mesenchymal cells plays intrinsic roles in regulating intestinal homeostasis. We find that Lats1/2 deletion drives robust mesenchymal over-proliferation, and YAP activation in Gli1+ pericryptal cells disrupts the intestinal epithelial-mesenchymal crosstalk via promoting Wnt ligand production. We show that YAP is upregulated in the stroma during dextran sodium sulfate (DSS)-induced injury, and mesenchymal YAP activation facilitates intestinal epithelial regeneration. Altogether, our data suggest an important role for mesenchymal Hippo-YAP signaling in the stem cell niche during intestinal homeostasis and pathogenesis.

Decoding gene expression profiles of Hippo signaling pathway components in breast cancer

INTRODUCTION

The Hippo signaling pathway is an evolutionarily conserved, tumor suppressor, stem cell pathway. This is the very less explored pathway in Breast Cancer. It is a crucial regulator of several biological processes, such as organ size, differentiation, tissue homeostasis, cellular proliferation, and stemness. Interestingly, deregulation of this pathway leads to tumorigenesis. Hence, the present study aims to identify the role of the Hippo signaling pathway in Breast Cancer.

MATERIALS AND METHODS

The mRNA expression of the Hippo signaling pathway molecules was evaluated in 120 pre-therapeutic patients by quantitative real-time PCR. Statistical analysis was carried out using SPSS 23. The association between the gene expression and clinicopathological parameters was analyzed by the paired sample t-test, and Pearson chi-square test. ROC curve analysis was carried out using Med Cal. A p-value of ≤ 0.05 was considered statistically significant.

RESULTS

The hippo signaling pathway contains 10 core components i.e.SAV1, MOB1A, MOB1B, MST1, MST2, LATS1, LATS2, YAP, TAZ, and TEAD1 which were downregulated in malignant tissues as compared to adjacent normal tissue in breast cancer. In the correlation of hippo signaling pathway molecules with clinico pathological parameters, only LATS1, MST1, and SAV1 were found to be significantly negatively associated with stages of Breast Cancer. MOB1B was found to be significantly positively correlated with stages of Breast Cancer. ROC curve analysis of YAP, TAZ, LATS2, and TEAD showed significant discrimination between adjacent normal and malignant tissue.

CONCLUSION

In the current study, all the molecules of the hippo signaling pathway i.e. YAP, TAZ, LATS1, LATS2, MST1, MST2, SAV1, MOB1, MOB1B, TEAD1 were downregulated in BC suggesting the activation of hippo pathway which played a significant role in tumor suppression.

YTHDF3-induced degradation of P4HA2 mRNA inhibits glycolysis in papillary thyroid cancer through Hippo signaling pathway

BACKGROUND

Prolyl-4-hydroxylase-A2 (P4HA2) is a pivotal enzyme involved in the regulation of tumorigenesis and progression. However, the precise biological roles and potential functions of P4HA2 in papillary thyroid cancer (PTC) remain poorly elucidated.

METHODS

Gain-of-function and loss-of-function approaches were employed to investigate the underlying biological effects of P4HA2 on PTC cell proliferation and metastasis both in vitro and in vivo. Furthermore, RIP assay, MeRIP assay, polysome fractionation, dual luciferase reporter assay, LC-MS/MS, and rescue experiments were conducted to explore the intricate relationships between YTHDF3, P4HA2 and Hippo signaling pathway.

RESULTS

P4HA2 exhibited significant up-regulation in PTC and was associated with unfavorable clinical characteristics and prognosis. In vitro and in vivo experiments demonstrated that P4HA2 promoted PTC cell proliferation and metastasis, while also contributing to tumorigenesis through the activation of glycolysis. Mechanistically, P4HA2 facilitated hydroxylation-mediated ubiquitination and degradation of SAV1, leading to enhanced expression of YAP1 in the Hippo signaling pathway. Additionally, YTHDF3 binding to P4HA2 mRNA in an N6-methyladenosine (m6A)-dependent manner decreased its stability, thereby inhibiting glycolysis in PTC.

CONCLUSION

The YTHDF3-regulated P4HA2 acts as an oncogenic factor, regulating glycolysis in PTC through the Hippo signaling pathway. This suggests that P4HA2 holds potential as a promising diagnostic marker and therapeutic target for patients with PTC.

DNA Methylation Regulatory Axis miR-29b-3p/DNMT3B Regulates Liver Regeneration Process by Altering LATS1

DNA methylation is a crucial epigenetic alteration involved in diverse biological processes and diseases. Hippo signalling pathway is a key signalling regulatory network in the growth and development of tissues and organs. Nevertheless, the precise role of DNA methylation and Hippo signalling pathway during liver regeneration (PH) is still unclear. In this study, we investigated the regulatory mechanism of LATS1, a pivotal protein in the Hippo signalling pathway, on liver regeneration and explored the specific mechanism of DNA methylation regulating LATS1. To analyse the regulation of LATS1 by DNA methylation, following 2/3 partial hepatectomy (PH) in liver-specific AAV-8 shDNMT3B deleted mice (DNMT3B, KD) mice and sex-matched AAV-8 shControl (Control). We determined that DNMT3B regulates the protein expression of LATS1 by DNA methylation. miR-29b-3p significantly regulates the expression of DNMT3B and alters LATS1 expression to inactivate the Hippo signalling pathway, thereby reducing the expression of cell proliferation and cycle proteins and inhibiting liver regeneration. Our results indicated that the miR-29b-3p/DNMT3B regulatory axis influences LATS1 expression through DNA methylation, and thereby promotes liver regeneration.

YAP/TAZ-associated cell signaling - at the crossroads of cancer and neurodevelopmental disorders

YAP/TAZ (Yes-associated protein/paralog transcriptional co-activator with PDZ-binding domain) are transcriptional cofactors that are the key and major downstream effectors of the Hippo signaling pathway. Both are known to play a crucial role in defining cellular outcomes, including cell differentiation, cell proliferation, and apoptosis. Aside from the canonical Hippo signaling cascade with the key components MST1/2 (mammalian STE20-like kinase 1/2), SAV1 (Salvador homologue 1), MOB1A/B (Mps one binder kinase activator 1A/B) and LATS1/2 (large tumor suppressor kinase 1/2) upstream of YAP/TAZ, YAP/TAZ activation is also influenced by numerous other signaling pathways. Such non-canonical regulation of YAP/TAZ includes well-known growth factor signaling pathways such as the epidermal growth factor receptor (EGFR)/ErbB family, Notch, and Wnt signaling as well as cell-cell adhesion, cell-matrix interactions and mechanical cues from a cell's microenvironment. This puts YAP/TAZ at the center of a complex signaling network capable of regulating developmental processes and tissue regeneration. On the other hand, dysregulation of YAP/TAZ signaling has been implicated in numerous diseases including various cancers and neurodevelopmental disorders. Indeed, in recent years, parallels between cancer development and neurodevelopmental disorders have become apparent with YAP/TAZ signaling being one of these pathways. This review discusses the role of YAP/TAZ in brain development, cancer and neurodevelopmental disorders with a special focus on the interconnection in the role of YAP/TAZ in these different conditions.

CK2α-mediated phosphorylation of DUB3 promotes YAP1 stability and oncogenic functions

The aberrant upregulation of Yes-associated protein 1 (YAP1) in a variety of solid cancers contributes to tumor progression and poor clinical outcomes, rendering it an appealing therapeutic target. However, effective therapies to directly target YAP1 remain challenging. In this study, we perform a high-throughput screening and identify Casein kinase II (CK2) as an uncharacterized upstream regulator of YAP1 turnover in cancer cells of ovarian cancer and several other cancer types. Pharmacological inhibition of Casein kinase II by Silmitasertib or genetic depletion of the catalytic subunit of Casein kinase II (CK2α) markedly destabilizes YAP1 and consequently suppresses its oncogenic functions in vitro and in vivo. Moreover, we reveal that DUB3 as a bona fide deubiquitinase of YAP1, which functionally links CK2 and YAP1 stability in a variety of human cancers. Mechanistically, CK2α directly phosphorylates DUB3 at Thr495, thereby facilitating DUB3-mediated deubiquitination process of YAP1. On the contrary, the loss of Thr495 phosphorylation by the phosphorylation-defective mutant DUB3 T495A, the cancer-related mutant DUB3 D496H and CK2 inhibition failed to deubiquitinate and stabilize YAP1 effectively. Notably, upregulated expressions of CK2α and DUB3 in ovarian cancer positively correlate with YAP1 overexpression. Collectively, our findings demonstrate the functional significance of the CK2α-DUB3 axis in YAP1 stabilization and YAP1-driven tumor progression, highlighting that strategies to target this axis might be of benefit in the clinical management of ovarian cancer and several other lethal cancers with aberrantly upregulated YAP1.

Positive feedback between arginine methylation of YAP and methionine transporter SLC43A2 drives anticancer drug resistance

Yes-associated protein (YAP) activation confers resistance to chemotherapy and targeted therapy. Methionine participates in cellular processes by converting to methyl donor for the methylation of DNA, RNA and protein. However, it remains unclear whether methionine affects drug resistance by influencing YAP activity. In this study, we report that methionine deprivation remarkably suppresses the transcriptional activity of YAP-TEAD in cancer cells. Methionine promotes PRMT1-catalyzed asymmetric dimethylation at R124 of YAP (YAP R124me2a). Mimicking of YAP methylation abolishes the reduction effect of methionine-restricted diet on YAP-induced drug resistance. YAP activates the transcription of SLC43A2, the methionine transporter, to increase methionine uptake in cancer cells. Knockdown of SLC43A2 decreases the level of YAP R124me2a. BCH, the inhibitor of SLC43A2, sensitizes tumors to anticancer drugs. Thus, our results unravel the positive feedback between YAP R124 methylation and SLC43A2 that contributes to anticancer drug resistance. Disrupting this positive feedback could be a potential strategy for cancer therapy.

Surviving the heat: The homeostatic regulation mechanism of endangered Brachymystax tsinlingensis

Conservation and utilization of Brachymystax tsinlingensis Li, 1966 (B. tsinlingensis), an endangered cold-water fish, is severely hampered by heat stress. In this study, heat stress and recovery experiments were firstly performed and implied that the intestine of B. tsinlingensis remained capable of self-regulation under heat stress. Therefore, transcriptome analysis was used to investigate the homeostatic mechanisms of B. tsinlingensis during temperature fluctuations. The results showed that a total of 5775 differentially expressed genes (DEGs) (1725 up- and 4050 down-regulated) were identified in the heat stress group, and 4312 DEGs (2024 up- and 2228 down-regulated) were identified in the recovery group when compared to their expression levels in the control group. Through Gene Set Enrichment Analysis (GSEA), citrate cycle (TCA cycle), oxidative phosphorylation, apoptosis, ferroptosis, focal adhesion, and tight junction pathways were found to be significantly up-regulated during heat stress, and declined during the recovery process. The results illustrated that heat stress caused ferroptosis and apoptosis in B. tsinlingensis. However, the organism was able to maintain homeostasis during temperature fluctuations modulating its energy metabolism, as well as the barrier and immune functions of the intestine. These findings help to enhance our understanding of the acclimation mechanisms of cold-water fish in present-day climate change.

Dual function of PHF16 in reinstating homeostasis of murine intestinal epithelium after crypt regeneration

Intestinal stem cells (ISCs) are highly vulnerable to damage, being in a constant state of proliferation. Reserve stem cells repair the intestinal epithelium following damage-induced ablation of ISCs. Here, we report that the epigenetic regulator plant homology domain (PHD) finger protein 16 (PHF16) restores homeostasis of the intestinal epithelium after initial damage-induced repair. In Phf16-/Y mice, revival stem cells (revSCs) showed defects in exiting the regenerative state, and intestinal crypt regeneration failed even though revSCs were still induced in response to tissue damage, as observed by single-cell RNA sequencing (scRNA-seq). Analysis of Phf16-/Y intestinal organoids by RNA sequencing (RNA-seq) and ATAC sequencing identified that PHF16 restores homeostasis of the intestinal epithelium by inducing retinoic acid receptor (RAR)/retinoic X receptor (RXR) target genes through HBO1-mediated histone H3K14 acetylation, while at the same time counteracting YAP/TAZ activity by ubiquitination of CDC73. Together, our findings demonstrate the importance of timely suppression of regenerative activity by PHF16 for the restoration of gut homeostasis after acute tissue injury.

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.

Notch signaling in digestive system cancers: Roles and therapeutic prospects

Digestive system cancers rank among the most prevalent malignant tumors, maintaining persistently high incidence and mortality rates. Notch signaling activity, often aberrant in esophageal, gastric, hepatic, pancreatic, and colorectal cancers, plays a pivotal role in the initiation, progression, and therapy resistance of these malignancies. As a highly conserved pathway, Notch signaling is integral to cell differentiation, survival, proliferation, stem cell renewal, development, and morphogenesis. Its dysregulation has been increasingly linked to various diseases, particularly digestive system cancers. In these malignancies, altered Notch signaling influences multiple biological processes, including cell proliferation, invasion, cell cycle progression, immune evasion, drug resistance, and stemness maintenance. Understanding the mechanisms of Notch signaling in digestive system cancers is essential for the development of novel targeted therapies. Numerous Notch pathway-targeting drugs are currently in preclinical studies, demonstrating promising efficacy both as monotherapies and in combination with conventional anti-cancer treatments. This review summarizes recent high-quality findings on the involvement of Notch signaling in digestive system cancers, focusing on the expression changes and pathological mechanisms of its dysregulated components. Special emphasis is placed on the potential of translating Notch-targeted approaches into therapeutic strategies, which hold promise for overcoming the limitations of existing treatments and improving the poor prognosis associated with these cancers.

The E3 ubiquitin ligase RNF6 facilitates the progression of cervical cancer by inhibiting the Hippo/Yap pathway

PURPOSE

Cervical cancer (CC), a significant global health threat, necessitates comprehensive understanding for improved therapeutic interventions. Many research indicates that dysregulation of the Hippo-YAP1 pathway leads to uncontrolled proliferation and invasion of tumor cells, promoting the progression of various cancers. This article aims to elucidate the role of RNF6 in CC and its regulation of the Hippo-YAP1 signaling pathway.

METHODS

The public tumor dataset analyses, immunohistochemistry, and western blotting were used to explore the expression of RNF6 in CC. Gain- and loss-of-function assays were conducted to elucidate the role of RNF6 in the proliferation and invasion of CC cells. Transcriptome sequencing was used to explore RNF6's role in cervical cancer, with validation of its regulation of the Hippo-YAP1 pathway through western blotting and RT-qPCR. Co-transfection of YAP overexpression plasmids into RNF6-silenced CC cells were preformed to confirm YAP1's pivotal role in RNF6-mediated CC progression. Animal experiments were preformed to further validate RNF6 interference's inhibitory effect on CC proliferation in vivo.

RESULTS

Clinical samples and bioinformatics analysis revealed high expression of RNF6 in CC, and closely associated with advanced FIGO (International Federation of Gynecology and Obstetrics) stage, larger tumor size, and poor prognosis. Cellular functional experiments demonstrate that RNF6 promotes the proliferation, invasion, and migration of CC cells, while knockdown of RNF6 yields the opposite effect. Transcriptome sequencing further reveals that RNF6 may promote CC progression through the Hippo-YAP signaling pathway. Western blotting and RT-qPCR further unveil that RNF6 enhances the upregulation of YAP1 protein levels, thereby activating downstream oncogenes CTGF and CYR61 transcription. Additionally, exogenous overexpression of YAP1 reverses the inhibitory effect of RNF6 silencing on CC proliferation and invasion. Furthermore, RNF6 interference significantly attenuates tumor growth in vivo experiments.

CONCLUSION

Our research reveals that RNF6 is highly expressed in CC, driving malignant progression by upregulating YAP1 protein expression and enhancing the transcription of downstream target genes CTGF and CYR61, offering potential therapeutic targets for CC treatment.

The long noncoding RNA ELFN1-AS1 promotes gastric cancer growth and metastasis by interacting with TAOK1 to inhibit the Hippo signaling pathway

Gastric cancer (GC) is a common digestive malignancy that causes numerous cancer-related deaths. Long noncoding RNAs (lncRNAs) play a crucial role in the development of various tumors, including GC. In this study, we revealed that ELFN1-AS1, a lncRNA with aberrantly high expression, contributes to the proliferation and metastasis of GC. Mechanically, ELFN1-AS1 plays an oncogenic role by binding to the protein kinase domain of thousand and one amino acid protein kinase (TAOK1), a tumor suppressor in GC, and disrupting the TAOK1-STK3 interaction, leading to decreased STK3 phosphorylation. This decrease is accompanied by attenuation of the Hippo kinase cascade, resulting in reduced YAP1 phosphorylation, a crucial effector of the Hippo signaling pathway. Subsequently, the reduced YAP1 phosphorylation promotes its nuclear translocation, thereby enhancing the expression of MYC, a downstream target of the pathway and well-known oncogene. Taken together, the ELFN1-AS1/TAOK1/STK3/YAP1 axis may promote GC progression and is a promising target for GC treatment.

The Hippo Signaling Pathway, Reactive Oxygen Species Production, and Oxidative Stress: A Two-Way Traffic Regulation

The Hippo signaling pathway is recognized for its significant role in cell differentiation, proliferation, survival, and tissue regeneration. Recently, the Hippo signaling pathway was also found to be associated with oxidative stress and reactive oxygen species (ROS) regulation, which are important in the regulation of cell survival. Studies indicate a correlation between components of the Hippo signaling pathway, including MST1, YAP, and TAZ, and the generation of ROS. On the other hand, ROS and oxidative stress can activate key components of the Hippo signaling pathway. For example, ROS production activates MST1, which subsequently phosphorylates FOXO3, leading to apoptotic cell death. ROS was also found to regulate YAP, in addition to MST1/2. Oxidative stress and ROS formation can impair lipids, proteins, and DNA, leading to many disorders, including aging, neurodegeneration, atherosclerosis, and diabetes. Consequently, understanding the interplay between the Hippo signaling pathway, ROS, and oxidative stress is crucial for developing future disease management strategies. This paper aimed to review the association between the Hippo signaling pathway, regulation of ROS production, and oxidative stress to provide beneficial information in understanding cell function and pathological processes.

Exposure to High Concentrations of Tetrabromobisphenol A Slows the Process of Tissue Regeneration and Induces an Imbalance of Metabolic Homeostasis in the Regenerated Intestines of Apostichopus japonicus

BACKGROUND

Tissue regenerative capacity following evisceration, potentially influenced by environmental contaminants and intestinal microflora, is essential for the financial success of Apostichopus japonicus farming. However, the morphological structure, gut microbiome composition, and genes expression pattern of the regenerated gut after exposure to high levels of TBBPA remain poorly unclear.

METHODS

In this research, the effect of TBBPA exposure on tissue regeneration in A. japonicus was investigated through a comprehensive multi-omics approach.

RESULTS

Our results showed that the integrity, the intestinal wall thickness, and the villi length of the regenerated intestines in A. japonicus decreased after treatment with high levels of TBBPA. The findings from PCoA and NMDS analyses revealed that the microbial community composition was significantly altered following exposure to high concentrations of TBBPA in the regenerated intestines of A. japonicus. The KEGG pathway enrichment analysis indicated that the DEGs (differentially expressed genes) were predominantly enriched on metabolism and immunity-related signaling pathways after exposure to high levels of TBBPA. These included pathways involved in the PPAR signaling pathway, ECM receptor interaction, glycerolipid metabolism, and fatty acid degradation. Interestingly, the results have demonstrated that there are 77 transcript factors that were significantly different after exposure to TBBPA.

CONCLUSIONS

These results suggested that high levels of exposure to TBBPA induces an imbalance of the metabolic homeostasis by regulating the expression levels of transcription factors in the regenerated intestines of A. japonicus.

Characterizing the effects of triclosan and triclocarban on the intestinal epithelial homeostasis using small intestinal organoids

Intestinal epithelium has the largest surface of human body, contributes dramatically to defense of toxicant-associated intestinal injury. Triclosan (TCS) and triclocarban (TCC), extensively employed as antibacterial agents in personal care products (PCPs) and healthcare facilities, caused serious damage to human intestine. However, the role of the intestinal epithelium in TCS/TCC-induced intestinal toxicity and its underlying toxic mechanisms remain incompletely understood. In this study, a novel 3D intestinal organoid model was utilized to investigate that exposure to TCS/TCC led to a compromised self-renewal and differentiation of intestinal stem cells (ISCs). Consequently, this disrupted intestinal epithelial homeostasis ultimately caused a reduction in nutrient absorption and deficient of epithelial defense to exogenous and endogenous pathogens stimulation. The inhibition of the Wnt signaling pathway in intestinal stem cell was contributed to the intestinal toxicity of TCS/TCC. These results were further confirmed in vivo with mice exposed to TCS/TCC. The findings of this study provide evidence that TCS/TCC possess the capacity to disturb the homeostasis of the intestinal epithelium, and emphasize the credibility of organoids as a valuable model for toxicological studies, as they could faithfully recapitulate in vivo phenomena.

Carboxypeptidase inhibitor Latexin (LXN) regulates intestinal organogenesis and intestinal remodeling involved in intestinal injury repair in mice

The self-renewal and regeneration of intestinal epithelium are mainly driven by intestinal stem cells resided in crypts, which are crucial for rapid recovery intestinal tissue following injury. Latexin (LXN) is a highly expressed stem cell proliferation and differentiation related gene in intestinal tissue. However, it is still ambiguous whether LXN participates in intestine regeneration by regulating intestinal stem cells (ISCs). Here, we report that LXN colocalizes with Leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5) in intestinal crypts, and deletion of LXN upregulates the expression of Lgr5 in intestinal crypts. LXN deficiency promotes the proliferation of ISCs, thereby enhances the development of intestinal organoids. Mechanically, we show that LXN deficiency enhances the expression of Lgr5 in ISCs by activating the Yes-associated protein (YAP) and wingless (Wnt) signal pathways, thus accelerating intestinal normal growth and regeneration post-injury. In summary, these findings uncover a novel function of LXN in intestinal regeneration post-injury and intestinal organogenesis, suggesting the potential role of LXN in the treatment of inflammatory bowel diseases.

Quiescent cancer cells induced by high-density cultivation reveals cholesterol-mediated survival and lung metastatic traits

BACKGROUND

The metastatic cascade, a multifaceted and highly aggressive process, is the primary cause of mortality. The survival of quiescent cancer cells in circulatory system during metastasis is crucial, yet our comprehension is constrained by the absence of universally accepted quiescent cancer models.

METHOD

We developed a quiescent cancer cell model using high-density cultivation. Based on the scRNA-seq analysis, IP-MS, metabolomics, mouse lung metastasis models, cholesterol assay, PLA and other molecular experiments, we explored the molecular mechanism. Immunofluorescence, atomic force microscope, FluidFM, and shear stress stimulation were used to analyze the cytoskeleton and membrane properties contributing to mechanical force resistance.

RESULT

We established a quiescent cancer cell model induced by high-density cultivation. Single-cell RNA sequencing (scRNA-seq) analysis reveals that CDC25A plays a crucial role in the transition to quiescence, with its expression significantly elevated in the quiescent state. Depletion of CDC25A leads to an increased proliferative capacity, and reduced metastasis under high-density conditions. Mechanistically, upregulated CDC25A in quiescent cells enhances cholesterol metabolism via endosome pathways, leading to cell cycle arrest. This increase in cholesterol reinforces the cytoskeleton, alters membrane properties, and improves resistance to mechanical forces in circulatory system.

CONCLUSION

CDC25A significantly increased the cholesterol metabolism through endosome pathway in quiescent cancer cells, leading to the significant changes in cytoskeleton and membrane properties so as to enhance the resistance of mechanical force in circulatory system, facilitating lung metastasis. In high-density cultivation, quiescent cancer cells, up-regulate cholesterol metabolism by CDC25A through endosome pathway, enhancing the resistance to mechanical force in circulatory system, facilitating lung metastasis.

MAFLD-related hepatocellular carcinoma: Exploring the potent combination of immunotherapy and molecular targeted therapy

Hepatocellular carcinoma (HCC) is a common cause of cancer-related mortality and morbidity globally, and with the prevalence of metabolic-related diseases, the incidence of metabolic dysfunction-associated fatty liver disease (MAFLD) related hepatocellular carcinoma (MAFLD-HCC) continues to rise with the limited efficacy of conventional treatments, which has created a major challenge for HCC surveillance. Immune checkpoint inhibitors (ICIs) and molecularly targeted drugs offer new hope for advanced MAFLD-HCC, but the evidence for the use of both types of therapy in this type of tumour is still insufficient. Theoretically, the combination of immunotherapy, which awakens the body's anti-tumour immunity, and targeted therapies, which directly block key molecular events driving malignant progression in HCC, is expected to produce synergistic effects. In this review, we will discuss the progress of immunotherapy and molecular targeted therapy in MAFLD-HCC and look forward to the opportunities and challenges of the combination therapy.

Hippo Signaling Pathway in Colorectal Cancer: Modulation by Various Signals and Therapeutic Potential

Colorectal cancer (CRC) stands as a significant global health issue, marked by elevated occurrence and mortality statistics. Despite the availability of various treatments, including chemotherapy, radiotherapy, and targeted therapy, CRC cells often exhibit resistance to these interventions. As a result, it is imperative to identify the disease at an earlier stage and enhance the response to treatment by acquiring a deeper comprehension of the processes driving tumor formation, aggressiveness, metastasis, and resistance to therapy. The Hippo pathway plays a critical role in facilitating the initiation of tumorigenesis and frequently experiences disruption within CRC because of genetic mutations and modified expression in its fundamental constituents. Targeting upstream regulators or core Hippo pathway components may provide innovative therapeutic strategies for modulating Hippo signaling dysfunction in CRC. To advance novel therapeutic techniques for CRC, it is imperative to grasp the involvement of the Hippo pathway in CRC and its interaction with alternate signaling pathways, noncoding RNAs, gut microbiota, and the immune microenvironment. This review seeks to illuminate the function and control of the Hippo pathway in CRC, ultimately aiming to unearth innovative therapeutic methodologies for addressing this ailment.

Pathways regulating intestinal stem cells and potential therapeutic targets for radiation enteropathy

Radiotherapy is a pivotal intervention for cancer patients, significantly impacting their treatment outcomes and survival prospects. Nevertheless, in the course of treating those with abdominal, pelvic, or retroperitoneal malignant tumors, the procedure inadvertently exposes adjacent intestinal tissues to radiation, posing risks of radiation-induced enteropathy upon reaching threshold doses. Stem cells within the intestinal crypts, through their controlled proliferation and differentiation, support the critical functions of the intestinal epithelium, ensuring efficient nutrient absorption while upholding its protective barrier properties. Intestinal stem cells (ISCs) regulation is intricately orchestrated by diverse signaling pathways, among which are the WNT, BMP, NOTCH, EGF, Hippo, Hedgehog and NF-κB, each contributing to the complex control of these cells' behavior. Complementing these pathways are additional regulators such as nutrient metabolic states, and the intestinal microbiota, all of which contribute to the fine-tuning of ISCs behavior in the intestinal crypts. It is the harmonious interplay among these signaling cascades and modulating elements that preserves the homeostasis of intestinal epithelial cells (IECs), thereby ensuring the gut's overall health and function. This review delves into the molecular underpinnings of how stem cells respond in the context of radiation enteropathy, aiming to illuminate potential biological targets for therapeutic intervention. Furthermore, we have compiled a summary of several current treatment methodologies. By unraveling these mechanisms and treatment methods, we aspire to furnish a roadmap for the development of novel therapeutics, advancing our capabilities in mitigating radiation-induced intestinal damage.

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.

Research progress of the Hippo signaling pathway in renal cell carcinoma

Objective

This review aimed to summarize the role of the Hippo signaling pathway in renal cell carcinoma (RCC), a urologic malignancy with subtle initial symptoms and high mortality rates due to metastatic RCC. The Hippo signaling pathway, which regulates tissue and organ sizes, plays a crucial role in RCC progression and metastasis. Understanding the involvement of the Hippo signaling pathway in RCC provides valuable insights for the development of targeted therapies and improved patient outcomes.

Methods

In this review, we explored the impact of the Hippo signaling pathway on RCC. Through an analysis of existing literature, we examined its role in RCC progression and metastasis. Additionally, we discussed potential therapeutic strategies targeting the Hippo pathway for inhibiting RCC cell growth and invasion. We also highlighted the importance of investigating interactions between the Hippo pathway and other signaling pathways such as Wnt, transforming growth factor-beta, and PI3K/AKT, which may uncover additional therapeutic targets.

Results

The Hippo signaling pathway has shown promise as a target for inhibiting RCC cell growth and invasion. Studies have demonstrated its dysregulation in RCC, with altered expression of key components such as yes-associated protein/transcriptional coactivator with PDZ-binding motif (YAP/TAZ). Targeting the Hippo pathway has been associated with suppressed tumor growth and metastasis in preclinical models of RCC. Furthermore, investigating crosstalk between the Hippo pathway and other signaling pathways has revealed potential synergistic effects that could be exploited for therapeutic interventions.

Conclusion

Understanding the role of the Hippo signaling pathway in RCC is of paramount importance. Elucidating its functions and molecular interactions contributes to RCC diagnosis, treatment, and the discovery of novel mechanisms. This knowledge informs the development of innovative therapeutic strategies and opens new avenues for research in RCC. Further investigations are warranted to fully comprehend the complex interplay between the Hippo pathway and other signaling pathways, ultimately leading to improved outcomes for RCC patients.

The hippo-YAP1/HIF-1α pathway mediates arsenic-induced renal fibrosis

Epidemiological evidence reveals that arsenic increases the risk of chronic kidney disease (CKD) in humans, but its mechanism of action has so far been unclear. Fibrosis is the manifestation of end-stage renal disease. Hypoxia is recognized as a vital event accompanying the progression of renal fibrosis. KM mice were exposed to 0, 20, 40, and 80 mg/L NaAsO2 for 12 weeks. HK-2 cells were treated with 1 μM NaAsO2 for 4 weeks. The results showed that arsenic increased the expression of hypoxia-inducible factor 1α (HIF-1α) (P < 0.05), which is involved in inorganic arsenic-induced renal fibrosis. The Hippo signaling pathway is the upstream signal of HIF-1α and the kinase cascade of Large tumor suppressor kinase 1 (LATS1) and Yes-associated protein 1 (YAP1) is the heart of the Hippo pathway. Our results showed that protein expressions of LATS1 and phosphorylated YAP1 were decreased, and dephosphorylated YAP1 expression increased in arsenic-treated mouse kidneys and human HK-2 cells (P < 0.05). Our research manifested that arsenic treatment suppressed the Hippo signaling and induced high expression of YAP1 into the nucleus. We also found that YAP1 was involved in arsenic-induced renal fibrosis by forming a complex with HIF-1α and maintaining HIF-1α stability. Our findings indicate that YAP1 is a potential target for molecular-based therapy for arsenic-mediated renal fibrosis.

Targeting the Hippo/YAP1 signaling pathway in hepatocellular carcinoma: From mechanisms to therapeutic drugs (Review)

The Hippo signaling pathway plays a pivotal role in regulating cell growth and organ size. Its regulatory effects on hepatocellular carcinoma (HCC) encompass diverse aspects, including cell proliferation, invasion and metastasis, tumor drug resistance, metabolic reprogramming, immunomodulatory effects and autophagy. Yes‑associated protein 1 (YAP1), a potent transcriptional coactivator and a major downstream target tightly controlled by the Hippo pathway, is influenced by various molecules and pathways. The expression of YAP1 in different cell types within the liver tumor microenvironment exerts varying effects on tumor outcomes, warranting careful consideration. Therefore, research on YAP1‑targeted therapies merits attention. This review discusses the composition and regulation mechanism of the Hippo/YAP1 signaling pathway and its relationship with HCC, offering insights for future research and cancer prevention strategies.

Urolithin A attenuates hexavalent chromium-induced small intestinal injury by modulating PP2A/Hippo/YAP1 pathway

Hexavalent chromium (Cr(VI)) exposure has been linked with gastrointestinal toxicity, whereas the molecular pathways and key targets remain elusive. Computational toxicology analysis predicted the correlation between protein phosphatase 2A (PP2A) and genes regarding Cr(VI)-induced intestinal injury. Here, we generated a mouse model with intestinal epithelium-specific knock out of Ppp2r1a (encoding PP2A Aα subunit) to investigate the mechanisms underlying Cr(VI)-induced small intestinal toxicity. Heterozygous (HE) mice and matched WT littermates were administrated with Cr(VI) at 0, 5, 20, and 80 mg/l for 28 successive days. Cr(VI) treatment led to crypt hyperplasia, epithelial cell apoptosis, and intestinal barrier dysfunction, accompanied by the decline of goblet cell counts and Occludin expression in WT mice. Notably, these effects were aggravated in HE mice, indicating that PP2A Aα deficiency conferred mice with susceptibility to Cr(VI)-induced intestinal injury. The combination of data analysis and biological experiments revealed Cr(VI) exposure could decrease YAP1 phosphorylation at Ser127 but increase protein expression and activity, together with elevated transcriptional coactivator with PDZ-binding motif protein driving epithelial crypt cells proliferation following damage, suggesting the involvement of Hippo/YAP1 signaling pathway in Cr(VI)-induced intestinal toxicity. Nevertheless, the enhanced phosphorylation of YAP1 in HE mice resulted in proliferation/repair defects in intestinal epithelium, thereby exacerbating Cr(VI)-induced gut barrier dysfunction. Notably, by molecular docking and further studies, we identified urolithin A, a microbial metabolite, attenuated Cr(VI)-induced disruption of intestinal barrier function, partly by modulating YAP1 expression and activity. Our findings reveal the novel molecular pathways participated in Cr(VI)-caused small intestinal injury and urolithin A could potentially protect against environmental hazards-induced intestinal diseases.

FATP5 modulates biological activity and lipid metabolism in prostate cancer through the TEAD4-mediated Hippo signaling

Introduction

Prostate cancer (PCa), one of the most prevalent malignant tumors in the genitourinary system, is characterized by distant metastasis and the development of castration-resistant prostate cancer (CRPC), which are major determinants of poor prognosis. Current treatment approaches for PCa primarily involve surgery and endocrine therapy, but effective strategies for managing distant metastasis and CRPC remain limited.

Methods

We utilized qPCR, WB, and other methods to measure the expression levels of respective proteins, concurrently assessing lipid metabolism to validate the role of FATP5 in lipid metabolism. Additionally, we employed bioinformatics analysis and WB techniques to explore the corresponding mechanisms.

Results

In this study, we conducted an analysis of clinical samples and public databases to identify differential expression of FATP5 and further investigated its association with clinical outcomes. Through biochemical and functional experiments, we elucidated the potential underlying mechanisms by which FATP5 facilitates the progression of PCa. Our findings demonstrate that specific upregulation of FATP5 significantly enhances proliferation, migration, and invasion of PCa cell lines, while also modulating lipid metabolism in PCa. Mechanistically, the expression of FATP5 is closely associated with the Hippo signaling pathway, as it promotes the nuclear accumulation of YAP1 by inhibiting AMPK and facilitating the activation of β-catenin and RHOA. Furthermore, the transcription of FATP5 is mediated by TEAD4, and this transcriptional activation requires the involvement of YAP1.

Discussion

FATP5 is highly expressed in prostate cancer and can enhance the biological activity and lipid metabolism of prostate cancer. We have also elucidated that FATP5 is regulated by the Hippo signaling pathway. This provides a new potential target for the treatment of prostate cancer.

The Prognostic Biomarker RAB7A Promotes Growth and Metastasis of Liver Cancer Cells by Regulating Glycolysis and YAP1 Activation

Activating transcription factor 6 (ATF6) and its downstream genes are involved in progression of hepatocellular carcinoma (HCC). Herein, we demonstrated that sulfhydration of Ras-related protein Rab-7a (RAB7A) was regulated by ATF6. High expression of RAB7A indicated poor prognosis of HCC patients. RAB7A overexpression contributed to proliferation, colony formation, migration, and invasion of HepG2 and Hep3B cells. Furthermore, we found that RAB7A enhanced aerobic glycolysis in HepG2 cells, indicating a higher degree of tumor malignancy. Mechanistically, RAB7A suppressed Yes-associated protein 1 (YAP1) binding to 14-3-3 and conduced to YAP1 nuclear translocation and activation, promoting its downstream gene expression, thereby promoting growth and metastasis of liver cancer cells. In addition, knocking down RAB7A attenuated the progression of orthotopic liver tumors in mice. These findings illustrate the important role of RAB7A in regulating HCC progression. Thus, RAB7A may be a potential innovative target for HCC treatment.

Hippo kinases Mst1 and Mst2 maintain NK cell homeostasis by orchestrating metabolic state and transcriptional activity

Natural killer (NK) cells play a crucial role in immune response against viral infections and tumors. However, further investigation is needed to better understand the key molecules responsible for determining the fate and function of NK cells. In this study, we made an important discovery regarding the involvement of the Hippo kinases Mst1 and Mst2 as novel regulators in maintaining mouse NK cell homeostasis. The presence of high Mst1 and Mst2 (Mst1/2) activity in NK cells is essential for their proper development, survival and function in a canonical Hippo signaling independent mode. Mechanistically, Mst1/2 induce cellular quiescence by regulating the processes of proliferation and mitochondrial metabolism, thereby ensuring the development and survival of NK cells. Furthermore, Mst1/2 effectively sense IL-15 signaling and facilitate the activation of pSTAT3-TCF1, which contributes to NK cell homeostasis. Overall, our investigation highlights the crucial role of Mst1/2 as key regulators in metabolic reprogramming and transcriptional regulation for mouse NK cell survival and function, emphasizing the significance of cellular quiescence during NK cell development and functional maturation.

Preparation of polyclonal antibodies to chicken P62 protein and its application in nephropathogenic infectious bronchitis virus-infected chickens

p62, also known as SQSTM1, has been shown to be closely related to the coronavirus. However, it remains unclear on the relationship between p62 and NIBV infection. Moreover, there are no available antibodies against the chicken p62 protein. Thus, this study aimed to prepare p62 polyclonal antibody and investigate the correlation between the p62 protein and NIBV infection. Here, PET-32a-p62 prokaryotic fusion expression vector was constructed for prokaryotic protein expression, and then p62 polyclonal antibody was prepared by immunizing rabbits. Lastly, these antibodies were then utilized in Western blotting (WB), immunohistochemistry (IHC), and immunofluorescence (IF) assays. The results showed that we successfully prepared chicken p62 polyclonal antibody. Meanwhile, WB and IF demonstrated that the expression of p62 showed a trend of first increase and then decrease after NIBV infection. IHC showed that the expression of p62 in the spleen, lung, kidney, bursa of Fabricius and trachea of chickens infected with NIBV in 11 dpi was significantly higher than that of normal chickens. Taken together, this study successfully prepared a polyclonal antibody for chicken p62 protein and confirmed its application and expression in chickens, as well as the expression of p62 in tissues after NIBV infection.

Endometrial stem cell-derived exosomes repair cisplatin-induced premature ovarian failure via Hippo signaling pathway

Stem cells have been documented as a new therapeutic method for ovarian injuries such as premature ovarian failure (POF). However, effects of exosomes (Exos) derived from human endometrial stem cells (EnSCs) on diminished ovarian failure remain to be carefully elucidated. Our study aims to investigate the mechanisms of EnSC-Exos in the recovery of the cisplatin-induced granulosa cell injury model in vitro or POF mouses model in vivo and whether the Hippo signaling pathway is involved in the regulation. In this study, we established successful construction of the cisplatin-induced granulosa cell injury model and evaluated Hippo signaling pathway activation in cisplatin-damaged granulosa cells (GCs). Furthermore, laser scanning confocal microscope and immunofluorescence demonstrated that EnSC-Exos can be transferred to cisplatin-damaged GCs to decrease apoptosis. In addition, the enhanced expression of YAP at the protein level as well as YAP/TEAD target genes, such as CTGF, ANKRD1, and the increase of YAP into the nucleus in immunofluorescence staining after the addition of EnSC-Exos to cisplatin-damaged GCs confirmed the suppression of Hippo signaling pathway. While in vivo, EnSC-Exos successfully remedied POF in a mouse model. Collectively, our findings suggest that chemotherapy-induced POF was associated with the activating of Hippo signaling pathway. Human EnSC-Exos significantly elevated the proliferation of ovarian GCs and the ovarian function by regulating Hippo signaling pathway. These findings provide new insights for further understanding of EnSC-Exos in the recovery of ovary function.

The AAA-ATPase Ter94 regulates wing size in Drosophila by suppressing the Hippo pathway

Insect wing development is a fascinating and intricate process that involves the regulation of wing size through cell proliferation and apoptosis. In this study, we find that Ter94, an AAA-ATPase, is essential for proper wing size dependently on its ATPase activity. Loss of Ter94 enables the suppression of Hippo target genes. When Ter94 is depleted, it results in reduced wing size and increased apoptosis, which can be rescued by inhibiting the Hippo pathway. Biochemical experiments reveal that Ter94 reciprocally binds to Mer, a critical upstream component of the Hippo pathway, and disrupts its interaction with Ex and Kib. This disruption prevents the formation of the Ex-Mer-Kib complex, ultimately leading to the inactivation of the Hippo pathway and promoting proper wing development. Finally, we show that hVCP, the human homolog of Ter94, is able to substitute for Ter94 in modulating Drosophila wing size, underscoring their functional conservation. In conclusion, Ter94 plays a positive role in regulating wing size by interfering with the Ex-Mer-Kib complex, which results in the suppression of the Hippo pathway.

Nuclear Localization of Yes-Associated Protein Is Associated With Tumor Progression in Cutaneous Melanoma

Yes-associated protein (YAP), an effector molecule of the Hippo signaling pathway, is expressed at high levels in cutaneous melanoma. However, the role of YAP in melanoma progression according to cellular localization is poorly understood. Tissues from 140 patients with invasive melanoma were evaluated by immunohistochemistry. Flow cytometry, western blotting, viability assays, wound healing assays, verteporfin treatment, and xenograft assays were conducted using melanoma cell lines B16F1 and B16F10 subjected to YapS127A transfection and siYap knockdown. Nuclear YAP localization was identified in 63 tumors (45.0%) and was more frequent than cytoplasmic YAP in acral lentiginous and nodular subtypes (P = .007). Compared with cytoplasmic YAP melanomas, melanomas with nuclear YAP had higher mitotic activity (P = .016), deeper invasion (P < .001), and more frequently metastasized to lymph nodes (P < .001) and distant organs (P < .001). Patients with nuclear YAP melanomas had poorer disease-free survival (P < .001) and overall survival (P < .001). Nuclear YAP was an independent risk factor for distant metastasis (hazard ratio: 3.206; 95% CI, 1.032-9.961; P = .044). Proliferative ability was decreased in siYapB16F1 (P < .001) and siYapB16F10 (P = .001) cells and increased in YapS127AB16F1 (P = .003) and YapS127AB16F10 (P = .002) cells. Cell cycle analysis demonstrated relative G1 retention in siYapB16F1 (P < .001) and siYapB16F10 (P < .001) cells and S retention in YapS127AB16F1 cells (P = .008). Wound healing assays showed that Yap knockdown inhibited cell invasion (siYapB16F1, P = .001; siYapB16F10, P < .001), whereas nuclear YAP promoted it (YapS127AB16F, P < .001; YapS127AB16F1, P = .017). Verteporfin, a direct YAP inhibitor, reduced cellular proliferation in B16F1 (P = .003) and B16F10 (P < .001) cells. Proliferative effects of nuclear YAP were confirmed in xenograft mice (P < .001). In conclusion, nuclear YAP in human melanomas showed subtype specificity and correlated with proliferative activity and proinvasiveness. It is expected that YAP becomes a useful prognostic marker, and its inhibition may be a potential therapy for melanoma patients.

Colonic crypt stem cell functions are controlled by tight junction protein claudin-7 through Notch/Hippo signaling

The tight junction protein claudin-7 is essential for tight junction function and intestinal homeostasis. Cldn7 deletion in mice leads to an inflammatory bowel disease-like phenotype exhibiting severe intestinal epithelial damage, weight loss, inflammation, mucosal ulcerations, and epithelial hyperplasia. Claudin-7 has also been shown to be involved in cancer metastasis and invasion. Here, we test our hypothesis that claudin-7 plays an important role in regulating colonic intestinal stem cell function. Conditional knockout of Cldn7 in the colon led to impaired epithelial cell differentiation, hyperproliferative epithelium, a decrease in active stem cells, and dramatically altered gene expression profiles. In 3D colonoid culture, claudin-7-deficient crypts were unable to survive and form spheroids, emphasizing the importance of claudin-7 in stem cell survival. Inhibition of the Hippo pathway or activation of Notch signaling partially rescued the defective stem cell behavior. Concurrent Notch activation and Hippo inhibition resulted in restored colonoid survival, growth, and differentiation to the level comparable to those of wild-type derived crypts. In this study, we highlight the essential role of claudin-7 in regulating Notch and Hippo signaling-dependent colonic stem cell functions, including survival, self-renewal, and differentiation. These new findings may shed light on potential avenues to explore for drug development in colorectal cancer.

Hippo/YAP1 promotes osteoporotic mice bone defect repair via the activating of Wnt signaling pathway

BACKGROUND

This study is to investigate the role and mechanism of Hippo/YAP1 in the repair of osteoporotic bone defects in aged mice, both in vivo and in vitro.

METHODS

We investigated the expression differences of the Hippo signaling in young and aged individuals both in vivo and in vitro. By manipulating the expression of Lats1/2 and Yap1, we investigated the role of Hippo/YAP1 in regulating osteogenic differentiation in aged BMSCs. In vivo, by intervening in the local and systemic expression of Lats1/2 and Yap1 respectively, we sought to demonstrate whether Hippo/YAP1 promotes the repair of bone defects in aged osteoporotic conditions. Finally, we delved into the underlying mechanisms of Hippo/YAP1 in regulating osteogenic differentiation.

RESULTS

We observed differences in the expression of the Hippo signaling between young and aged individuals. After knocking out Lats1/2 in aged BMSCs, we observed that the upregulation of endogenous YAP1 promotes cellular osteogenic differentiation and proliferation capacity. Through interference with Yap1 expression, we provided strong evidence for the role of Hippo/YAP1 in promoting osteogenic differentiation in aged BMSCs. In vivo, we confirmed that Hippo/YAP1 promotes the repair of bone defects in aging osteoporosis. Moreover, we discovered an interaction relationship among YAP1, β-catenin, and TEAD1.

CONCLUSION

This study elucidates the role of Hippo/YAP1 in promoting the repair of osteoporotic bone defects in aged mice. Mechanistically, YAP1 functions by activating the Wnt/β-catenin pathway, and this process is not independent of TEAD1.

Pasteurella multocida activates Rassf1-Hippo-Yap pathway to induce pulmonary epithelial apoptosis

Pasteurella multocida is an opportunistic zoonotic pathogen that primarily causes fatal respiratory diseases, such as pneumonia and respiratory syndromes. However, the precise mechanistic understanding of how P. multocida disrupts the epithelial barrier in mammalian lung remains largely unknown. In this study, using unbiased RNA-seq analysis, we found that the evolutionarily conserved Hippo-Yap pathway was dysregulated after P. multocida infection. Given the complexity of P. multocida infection associated with lung injury and systemic inflammatory processes, we employed a combination of cell culture models, mouse models, and rabbit models to investigate the dynamics of the Hippo-Yap pathway during P. multocida infection. Our findings reveal that P. multocida infection activates the Hippo-Yap pathway both in vitro and in vivo, by upregulating the upstream factors p-Mst1/2, p-Lats1, and p-Yap, and downregulating the downstream effectors Birc5, Cyr61, and Slug. Conversely, pharmacological inhibition of the Hippo pathway by XMU-MP-1 significantly rescued pulmonary epithelial cell apoptosis in vitro and reduced lung injury, systemic inflammation, and mouse mortality in vivo. Mechanistic studies revealed that P. multocida induced up-regulation of Rassf1 expression, and Rassf1 enhanced Hippo-Yap pathway through phosphorylation. Accordingly, in vitro knockdown of Rassf1 significantly enhanced Yap activity and expression of Yap downstream factors and reduced apoptosis during P. multocida infection. P. multocida-infected rabbit samples also showed overexpression of Rassf1, p-Lats1, and p-Yap, suggesting that P. multocida activates the Rassf1-Hippo-Yap pathway. These results elucidate the pathogenic role of the Rassf1-Hippo-Yap pathway in P. multocida infection and suggest that this pathway has the potential to be a drug target for the treatment of pasteurellosis.

Hippo cooperates with p53 to maintain foregut homeostasis and suppress the malignant transformation of foregut basal progenitor cells

Basal progenitor cells serve as a stem cell pool to maintain the homeostasis of the epithelium of the foregut, including the esophagus and the forestomach. Aberrant genetic regulation in these cells can lead to carcinogenesis, such as squamous cell carcinoma (SCC). However, the underlying molecular mechanisms regulating the function of basal progenitor cells remain largely unknown. Here, we use mouse models to reveal that Hippo signaling is required for maintaining the homeostasis of the foregut epithelium and cooperates with p53 to repress the initiation of foregut SCC. Deletion of Mst1/2 in mice leads to epithelial overgrowth in both the esophagus and forestomach. Further molecular studies find that Mst1/2-deficiency promotes epithelial growth by enhancing basal cell proliferation in a Yes-associated protein (Yap)-dependent manner. Moreover, Mst1/2 deficiency accelerates the onset of foregut SCC in a carcinogen-induced foregut SCC mouse model, depending on Yap. Significantly, a combined deletion of Mst1/2 and p53 in basal progenitor cells sufficiently drives the initiation of foregut SCC. Therefore, our studies shed light on the collaborative role of Hippo signaling and p53 in maintaining squamous epithelial homeostasis while suppressing malignant transformation of basal stem cells within the foregut.

Prognostic analysis of Yes-associated protein 1 in patients with colorectal cancer. A systematic review and meta-analysis

BACKGROUND

colorectal cancer (CRC) is the most common carcinoma worldwide, but a lack of effective prognostic markers limits clinical diagnosis and treatment. Yes-associated protein 1 (YAP1) is an effector of the HIPPO-pathway, which plays a critical role in cancer development and prognosis, including CRC. However, previous reports have suggested that it plays a dual role in CRC.

METHODS

a meta-analysis using RevMan 5.4 and Stata 14.0 was performed to evaluate the relationship between YAP1 and clinical outcomes of CRC, after searching for eligible studies in the PubMed, Web of Science and Embase databases. Online datasets GEPIA and LOGpc were also used to calculate survival results and for comparison with the meta-analysis results. Besides, "DESeq" packages were used for the expression analysis of YAP1 from the TCGA dataset.

RESULTS

YAP1 was overexpressed in the cancer tissues when compared to normal tissues in patients with CRC from the TCGA database (p = 0.000164) and GEPIA database. A total of 10 studies involving 2305 patients from the literature were selected. Pooled HR indicated that overexpression of YAP1 was associated with poor clinical outcomes (HR = 1.70, 95 % CI: 1.28-2.26, p = 0.0003). Subgroup analysis showed a clear correlation between overexpression of YAP1 and worse survival rate in Chinese patients (HR = 1.94, 95 % CI: 1.40-2.69, p = 0.0001), nuclear YAP1 overexpression (HR = 2.07, 95 % CI: 1.29-3.31, p = 0.003), 60 months of follow-up (HR = 1.89, 95 % CI: 1.30-2.73, p = 0.0008), IHC test (HR = 1.65, 95 % CI: 1.17-2.33, p = 0.005), IHC combined with other tests (HR = 1.77, 95 % CI: 1.13-2.77, p = 0.01) and multivariate analysis (HR = 1.70, 95 % CI: 1.24-2.31, p = 0.0009). Nevertheless, disease-free survival (DFS) showed no significant results in the patients with CRC in our meta-analysis (HR = 1.38, 95 % CI: 0.51-3.75, p = 0.52) as well as in the GEPIA and LOGpc databases. Meanwhile, YAP1 overexpression was also significantly associated with worse overall survival (OS) in GSE17536, GSE40967, GSE29623 and GSE71187.

CONCLUSION

YAP1 overexpression is common in CRC tissues. Overexpression of YAP1 in CRC patients, particularly in the nucleus, might be related to shorter OS, maybe in the early stages. YAP1 could serve as a potential predictor of poor prognosis in CRC.

Mechanisms of Immune Sensing of DNA Damage

Genomic stability relies on a multifaceted and evolutionarily conserved DNA damage response (DDR). In multicellular organisms, an integral facet of the DDR involves the activation of the immune system to eliminate cells with persistent DNA damage. Recent research has shed light on a complex array of nucleic acid sensors crucial for innate immune activation in response to oncogenic stress-associated DNA damage, a process vital for suppressing tumor formation. Yet, these immune sensing pathways may also be co-opted to foster tolerance of chromosomal instability, thereby driving cancer progression. This review aims to provide an updated overview of how the innate immune system detects and responds to DNA damage. An improved understanding of the regulatory intricacies governing this immune response may uncover new avenues for cancer prevention and therapeutic intervention.

YAP represses intestinal inflammation through epigenetic silencing of JMJD3

BACKGROUND

Epigenetics plays an important role in the pathogenesis of inflammatory bowel disease (IBD). Some studies have reported that YAP is involved in inflammatory response and can regulate target genes through epigenetic modifications. JMJD3, a histone H3K27me3 demethylase, is associated with some inflammatory diseases. In this study, we investigated the role of YAP in the development of IBD and the underlying epigenetic mechanisms.

RESULTS

YAP expression was significantly increased in both in vitro and in vivo colitis models as well as in patients with IBD. Epithelial-specific knockout of YAP aggravates disease progression in dextran sodium sulfate (DSS)-induced murine colitis. In the TNF-α-activated cellular inflammation model, YAP knockdown significantly increased JMJD3 expression. Coimmunoprecipitation experiments showed that YAP and EZH2 bind to each other, and chromatin immunoprecipitation-PCR (ChIP-PCR) assay indicated that silencing of YAP or EZH2 decreases H3K27me3 enrichment on the promoter of JMJD3. Finally, administration of the JMJD3 pharmacological inhibitor GSK-J4 alleviated the progression of DSS-induced murine colitis.

CONCLUSION

Our findings elucidate an epigenetic mechanism by which YAP inhibits the inflammatory response in colitis through epigenetic silencing of JMJD3 by recruiting EZH2.

The underlying mechanisms of DNA methylation in high salt memory in hypertensive vascular disease

This study demonstrates the effect and DNA methylation-related mechanisms of a high-salt diet and salt memory-induced hypertension and vasculopathy. Thirty Sprague Dawley rats were randomly divided into a control (CON) group (n = 6) and a modeling group (n = 24). A 12% NaCl solution (1 mL/100 g) was intragastrically administered for 60 consecutive days for modeling. An increase in blood pressure up to 140 mmHg was considered successful modeling. Twelve of fifteen successfully modeled rats were randomly selected and divided into a High Salt Diet (HSD) group and a High Salt Memory (HSM) group (n = 6). Rats in HSD group were intragastrically administered a 12% NaCl solution, while rats in HSM group were administered a 3% NaCl solution twice a day for 30 days. At the end of the intervention, blood pressure and the serum levels of ET-1, NO, TNF-α and IL-1β were measured. RRBS-heavy sulfite sequencing technology was selected for DNA methylation analysis. The systolic blood pressure of rats in the HSD group and HSM group was significantly higher than that in the CON group. Compared with those in the CON group, the serum levels of ET-1 in the HSM group and the serum levels of NO in the HSD group and HSM group were significantly increased. The methylation level of the CON group was lower than that of the HSD group and the HSM group, and there was no significant difference between the HSD group and the HSM group. The methylation level of Myoz3 was downregulated in the HSD group and HSM group. The methylation level of Fgd3 were upregulated in HSD group and downregulated in the HSM group. The methylation levels of AC095693.1, Adamts3, PDGFA and PDGFRα were downregulated in the HSD group and upregulated in the HSM group. According to the GO database, the differentially methylated genes were significantly enriched in the coordination of cell function, genetic development, and RNA transcription. There were three main metabolic pathways that were enriched in the differentially expressed genes between the groups: the PI3K-Akt signaling pathway, MAPK signaling pathway, and Hippo signaling pathway. Excessive salt intake may cause hypertension and vascular damage, and this damage may continue after the reduction of salt intake. Therefore, salt memory phenomenon exists, and this memory effect may be correlated with the levels of DNA methylation.

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

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.

Regulation of Hippo-YAP/CTGF signaling by combining an HDAC inhibitor and 5-fluorouracil in gastric cancer cells

Histone deacetylase (HDAC) inhibitors diminish carcinogenesis, metastasis, and cancer cell proliferation by inducing death in cancer cells. Tissue regeneration and organ development are highly dependent on the Hippo signaling pathway. Targeting the dysregulated hippo pathway is an excellent approach for cancer treatment. According to the results of this study, the combination of panobinostat, a histone deacetylase inhibitor, and 5-fluorouracil (5-FU), a chemotherapy drug, can act synergistically to induce apoptosis in gastric cancer cells. The combination of panobinostat and 5-FU was more effective in inhibiting cell viability than either treatment alone by elevating the protein levels of cleaved PARP and cleaved caspase-9. By specifically targeting E-cadherin, vimentin, and MMP-9, the combination of panobinostat and 5-FU significantly inhibited cell migration. Additionally, panobinostat significantly increased the anticancer effects of 5-FU by activating Hippo signaling (Mst 1 and 2, Sav1, and Mob1) and inhibiting the Akt signaling pathway. As a consequence, there was a decrease in the amount of Yap protein. The combination therapy of panobinostat with 5-FU dramatically slowed the spread of gastric cancer in a xenograft animal model by deactivating the Akt pathway and supporting the Hippo pathway. Since combination treatment exhibits much higher anti-tumor potential than 5-FU alone, panobinostat effectively potentiates the anti-tumor efficacy of 5-FU. As a result, it is believed that panobinostat and 5-FU combination therapy will be useful as supplemental chemotherapy in the future.

YAP-mediated trophoblast dysfunction: the common pathway underlying pregnancy complications

Yes-associated protein (YAP) is a pivotal regulator in cellular proliferation, survival, differentiation, and migration, with significant roles in embryonic development, tissue repair, and tumorigenesis. At the maternal-fetal interface, emerging evidence underscores the importance of precisely regulated YAP activity in ensuring successful pregnancy initiation and progression. However, despite the established association between YAP dysregulation and adverse pregnancy outcomes, insights into the impact of aberrant YAP levels in fetal-derived, particularly trophoblast cells, and the ensuing dysfunction at the maternal-fetal interface remain limited. This review comprehensively examines YAP expression and its regulatory mechanisms in trophoblast cells throughout pregnancy. We emphasize its integral role in placental development and maternal-fetal interactions and delve into the correlations between YAP dysregulation and pregnancy complications. A nuanced understanding of YAP's functions during pregnancy could illuminate intricate molecular mechanisms and pave the way for innovative prevention and treatment strategies for pregnancy complications. Video Abstract.