Skeletal muscles are essential for locomotion, posture, and metabolic regulation. To understand physiological processes, exercise adaptation, and muscle-related disorders, it is critical to understand the molecular pathways that underlie skeletal muscle function. The process of muscle contraction, orchestrated by a complex interplay of molecular events, is at the core of skeletal muscle function. Muscle contraction is initiated by an action potential and neuromuscular transmission requiring a neuromuscular junction. Within muscle fibers, calcium ions play a critical role in mediating the interaction between actin and myosin filaments that generate force. Regulation of calcium release from the sarcoplasmic reticulum plays a key role in excitation-contraction coupling. The development and growth of skeletal muscle are regulated by a network of molecular pathways collectively known as myogenesis. Myogenic regulators coordinate the differentiation of myoblasts into mature muscle fibers. Signaling pathways regulate muscle protein synthesis and hypertrophy in response to mechanical stimuli and nutrient availability. Several muscle-related diseases, including congenital myasthenic disorders, sarcopenia, muscular dystrophies, and metabolic myopathies, are underpinned by dysregulated molecular pathways in skeletal muscle. Therapeutic interventions aimed at preserving muscle mass and function, enhancing regeneration, and improving metabolic health hold promise by targeting specific molecular pathways. Other molecular signaling pathways in skeletal muscle include the canonical Wnt signaling pathway, a critical regulator of myogenesis, muscle regeneration, and metabolic function, and the Hippo signaling pathway. In recent years, more details have been uncovered about the role of these two pathways during myogenesis and in developing and adult skeletal muscle fibers, and at the neuromuscular junction. In fact, research in the last few years now suggests that these two signaling pathways are interconnected and that they jointly control physiological and pathophysiological processes in muscle fibers. In this review, we will summarize and discuss the data on these two pathways, focusing on their concerted action next to their contribution to skeletal muscle biology. However, an in-depth discussion of the non-canonical Wnt pathway, the fibro/adipogenic precursors, or the mechanosensory aspects of these pathways is not the focus of this review.

Colorectal cancer (CRC) is linked to the WNT/β-catenin signaling as its primary driver. Aberrant activation of WNT/β-catenin signaling is closely correlated with increased incidence, malignancy, poorer prognosis, and even higher cancer-related death. Research over the years has postulated various experimental models that have facilitated an understanding of the complex mechanisms underlying WNT signaling in CRC. In the present review, we have comprehensively summarized the in vitro, in vivo, patient-derived, and computational models used to study the role of WNT signaling in CRC. We discuss the use of CRC cell lines and organoids in capturing the molecular intricacies of WNT signaling and implementing xenograft and genetically engineered mouse models to mimic the tumor microenvironment. Patient-derived models, including xenografts and organoids, provide valuable insights into personalized medicine approaches. Additionally, we elaborated on the role of computational models in simulating WNT signaling dynamics and predicting therapeutic outcomes. By evaluating the advantages and limitations of each model, this review highlights the critical contributions of these systems to our understanding of WNT signaling in CRC. We emphasize the need to integrate diverse model systems to enhance translational research and clinical applications, which is the primary goal of this review.

The liver has a unique ability to regenerate to meet the body's metabolic needs, even following acute or chronic injuries. The cellular and molecular mechanisms underlying normal liver regeneration have been well investigated to improve organ transplantation outcomes. Once liver regeneration is impaired, pathological regeneration occurs, and the underlying cellular and molecular mechanisms require further investigations. Nevertheless, a plethora of cytokines and growth factor-mediated pathways have been reported to modulate physiological and pathological liver regeneration. Regenerative mitogens play an essential role in hepatocyte proliferation. Accelerator mitogens in synergism with regenerative ones promote liver regeneration following hepatectomy. Finally, terminator mitogens restore the proliferating status of hepatocytes to a differentiated and quiescent state upon completion of regeneration. Chronic loss of hepatocytes, which can manifest in chronic liver disorders of any etiology, often has undesired structural consequences, including fibrosis, cirrhosis, and liver neoplasia due to the unregulated proliferation of remaining hepatocytes. In fact, any impairment in the physiological function of the terminator mitogens results in the progression of pathological liver regeneration. In the current review, we intend to highlight the updated cellular and molecular mechanisms involved in liver regeneration and discuss the impairments in central regulating mechanisms responsible for pathological liver regeneration.

Insights into the molecular processes that drive early development of the human placenta is crucial for our understanding of pregnancy complications such as preeclampsia and fetal growth restriction, since defects in maturation of its epithelial cell, the trophoblast, have been detected in the severe forms of these diseases. However, key regulators specifying the differentiated trophoblast subtypes of the placenta are only slowly emerging. By using diverse trophoblast cell models, we herein show that the transcriptional coactivator of HIPPO signaling, TAZ, plays a pivotal role in the development of invasive extravillous trophoblasts (EVTs), cells that are essential for decidual vessel remodeling and adaption of maternal blood flow to the placenta. Ribonucleic acid sequencing (RNA-seq) or protein analyses upon TAZ gene silencing or CRISPR-Cas9-mediated knockout in differentiating trophoblast stem cells, organoids, primary EVTs, choriocarcinoma cells, or villous explant cultures unraveled that the coactivator promoted expression of genes associated with EVT identity, motility, and survival. Accordingly, depletion or chemical inhibition of TAZ, interacting with TEA domain family member 1 (TEAD1), impaired EVT differentiation, invasion, and migration and triggered apoptosis in the different trophoblast models. Notably, the coactivator also suppressed cell cycle genes and regulators of trophoblast self-renewal and prevented EVTs from cell fusion in organoids and primary cultures. Moreover, TAZ promoted human leukocyte antigen G (HLA-G) surface expression and increased NUAK1 kinase in EVTs thereby maintaining its own expression. In summary, the transcriptional coactivator TAZ plays a multifaceted role in the development of the EVT cell lineage by controlling different biological processes that initiate and preserve differentiation.

The PDZ domain-containing protein ZO-2 is defined as a tight junction (TJ) protein, but is also known to have a role in the maintenance of cellular apicobasal polarity and to function as a signalling molecule in several pathways, including the Hippo pathway. In this issue, Liu OX et al. [(2024) FEBS J, https://doi.org/10.1111/febs.17304] report how the multiple protein binding sites of ZO2 protein allow it to act as a scaffold to facilitate its signalling functions.

Increased evidence reveals that glycolysis is one of the key metabolic hallmarks of cancer cells. However, the roles of lncRNA FTX in energy metabolism and cancer progression remain unclear. In this study we aim to show that lncRNA FTX was significantly upregulated in cancer tissues and serum of CRC patients and CRC cell lines. Function study indicated that it could promote aerobic glycolysis, cell proliferation, migration and invasion in colorectal cancer cells. Further mechanistic studies showed, lncRNA FTX was found to function as a sponge for miR-215-3p, which reduced the ability of miR-215-3p to repress the YAP1 oncoprotein. Additionally, a negative correlation was observed between lncRNA FTX and miR-215-3p expression, and the knockdown of lncRNA FTX or miR-215-3p overexpression yielded opposite effects. In conclusion, this study demonstrates that FTX could directly combine with miR-215-3p as a competitive endogenous RNA, thus promoting the aerobic glycolysis and progression of CRC in vitro and in vivo.

The tumor suppressor protein, p53, which is mutated in half of human tumors, plays a critical role in cellular responses to DNA damage and maintenance of genome stability. Therefore, increasing our understanding of the p53 pathway is essential for improving cancer treatment and diagnosis.

This study, which aimed to identify genes and pathways that mediate resistance to p53 upregulation, used genome-wide CRISPR-Cas9 loss-of-function screening done with Nutlin-3a, which inhibits p53-MDM2 interaction, resulting in p53 accumulation and apoptotic cell death. We used bioinformatics analysis for the identification of genes and pathways that are involved in the p53 pathway and cell survival assays to validate specific genes. In addition, we used RNA-seq to identify differentially expressed p53 target genes in gene knockout (KO) cell lines.

Our screen revealed three significantly enriched pathways: The heparan sulfate glycosaminoglycan biosynthesis, diphthamide biosynthesis and Hippo pathway. Notably, TRIP12 was significantly enriched in our screen. We found that TRIP12 is required for the p53-dependent transcription of several pro-apoptotic genes.

Our study has identified two novel pathways that play a role in p53-mediated growth restriction. Moreover, we have highlighted the interaction between the Hippo and the p53 pathways. Interestingly, we have shown that TRIP12 plays an important function in the p53 pathway by selectively affecting its role as a transcription factor.

5-methylcytosine (5mC) is a common form of DNA methylation, essentially acting as an epigenetic modification that regulates gene expression by affecting the binding of transcription factors to DNA or by recruiting proteins that make it difficult to recognize and transcribe genes. 5mC methylation is present in eukaryotes in a variety of places, such as in CpG islands, within gene bodies, and in regions of repetitive sequences, whereas in prokaryotic organisms, it is mainly present in genomic DNA. The Hippo pathway is a highly conserved signal transduction pathway, which is extremely important in cell proliferation and death, controlling the size of tissues and organs and regulating cell differentiation, in addition to its important regulatory roles in lipid synthesis, transport, and catabolism. Lipid metabolism is an important part of various metabolic pathways in the human body, and problems in lipid metabolism are related to abnormalities in key enzymes, related proteins, epigenetic inheritance, and certain specific amino acids, which are the key factors affecting its proper regulation. In this article, we will introduce the molecular mechanisms of 5mC methylation and the Hippo signaling pathway, and the possibility of their co-regulation of lipid metabolism, with the aim of providing new ideas for further research and novel therapeutic modalities for lipid metabolism and a reference for the development and exploration of related research.

Astrocytes contribute to the development and regulation of the higher-level functions of the brain, the critical targets of evolution. However, how astrocytes evolve in primates is unsettled. Here, we obtain human, chimpanzee, and macaque induced pluripotent stem-cell-derived astrocytes (iAstrocytes). Human iAstrocytes are bigger and more complex than the non-human primate iAstrocytes. We identify new loci contributing to the increased human astrocyte. We show that genes and pathways implicated in long-range intercellular signaling are activated in the human iAstrocytes and partake in controlling iAstrocyte complexity. Genes downregulated in human iAstrocytes frequently relate to neurological disorders and were decreased in adult brain samples. Through regulome analysis and machine learning, we uncover that functional activation of enhancers coincides with a previously unappreciated, pervasive gain of "stripe" transcription factor binding sites. Altogether, we reveal the transcriptomic signature of primate astrocyte evolution and a mechanism driving the acquisition of the regulatory potential of enhancers.

Bone defects caused by fractures and diseases often do not heal spontaneously. They require external agents for repair and regeneration. Bone tissue engineering is emerging as a promising alternative to traditional therapies like autografts and allografts. Nanobiomaterials enhance osteoblast resistance to harsh environments by promoting cell differentiation. Black phosphorus (BP), a novel 2D material in biomedicine, displays unique osteogenic and antimicrobial properties. However, BP nanosheets still face clinical limitations like rapid degradation and high-dose cytotoxicity. To address these, the introduction of amino-silicon phthalocyanine (SiPc-NH2) is investigated to see if it can enhance BP dispersion, reduce BP oxidation, and improve stability and safety for better osteogenesis and antibacterial effects through noncovalent interactions (van der Waals, π-π stacking and electrostatic interactions). Here, the self-healing hydrogel is successfully designed using a step-by-step co-assembly of BP and SiPc-NH2. SiPc-NH2 as a "structural stabilizer" of BP nanosheets reconstructed well-dispersed BP-SiPc-NH2 nanosheets, which improves the biocompatibility of BP, reduces oxidation and enhances photothermal conversion, guaranteeing osteogenic and antimicrobial properties. Furthermore, findings show BP-SiPc-NH2-induced mitochondrial changes support osteogenesis by regulating the crosstalk between Hippo and Wnt signaling pathways-mediated mitochondrial homeostasis, and boosting cellular bioenergetics. Overall, this mitochondrial morphology-based BP-SiPc-NH2 strategy holds great promise for bone repair applications.

Wolff's Law and the Mechanostat Theory elucidate how bone tissues detect and convert mechanical stimuli into biological signals, crucial for maintaining bone equilibrium. Abnormal mechanics can lead to diseases such as osteoporosis, osteoarthritis, and nonunion fractures. However, the detailed molecular mechanisms by which mechanical cues are transformed into biological responses in bone remain underexplored. Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ), key regulators of bone homeostasis, are instrumental in this process. Emerging research highlights bone cells' ability to sense various mechanical stimuli and relay these signals intracellularly. YAP/TAZ are central in receiving these mechanical cues and converting them into signals that influence bone cell behavior. Abnormal YAP/TAZ activity is linked to several bone pathologies, positioning these proteins as promising targets for new treatments. Thus, this review aims to provide an in-depth examination of YAP/TAZ's critical role in the interpretation of mechanical stimuli to biological signals, with a special emphasis on their involvement in bone cell mechanosensing, mechanotransduction, and mechanoresponse. The translational potential of this article: Clinically, appropriate stress stimulation promotes fracture healing, while bed rest can lead to disuse osteoporosis and excessive stress can cause osteoarthritis or bone spurs. Recent advancements in the understanding of YAP/TAZ-mediated mechanobiological signal transduction in bone diseases have been significant, yet many aspects remain unknown. This systematic review summarizes current research progress, identifies unaddressed areas, and highlights potential future research directions. Advancements in this field facilitate a deeper understanding of the molecular mechanisms underlying bone mechanics regulation and underscore the potential of YAP/TAZ as therapeutic targets for bone diseases such as fractures, osteoporosis, and osteoarthritis.

CCN2 is widely regarded as a profibrotic factor involved in fibrotic disorders by regulating extracellular matrix (ECM). We report here that CCN2 functions as a critical cell cycle regulator in primary human dermal fibroblasts (HDFs). siRNA-mediated knockdown of CCN2 halted proliferation of primary HDFs, which was rescued by a siRNA-resistant CCN2 expression vector. Furthermore, CCN2 knockdown caused a significant accumulation of cells in G1/G0 phase and blocked entry into S-phase. Mechanistically, CCN2 knockdown blocked cyclin E and CDK4/cyclin D nuclear translocation, and abrogated CDK2 activity. Markedly, CCN2 translocated to the nucleus and co-localized with cyclin D1 upon cell cycle stimulation. Finally, we show that CCN2, a bona fide YAP/TAZ target gene, partially mediates YAP/TAZ-dependent proliferation of primary HDFs. These data provide evidence of a novel CCN2 function as a cell cycle regulator in primary HDFs proliferation, in addition to its known role in ECM regulation.

Endothelial cell (EC) senescence is an accomplice for vascular aging, which leads to cardiovascular diseases (CVDs). Evidences showed that Hippo-Yes-associated protein (YAP) signaling pathway plays an essential role in aging-associated CVDs. Here, we reported that YAP was elevated in senescent human umbilical vein endothelial cells (HUVECs) and inhibition of YAP could attenuate HUVECs senescence. Besides, our findings revealed that the activity of UFMylation and the level of YAP were both elevated in senescent cells. Furthermore, UFM1-modified YAP was upregulated in senescent ECs, and increased the stability of YAP. Importantly, we found that compound 8.5, an inhibitor of E1 of UFMylation, can alleviate vascular aging in aged mice. Together, our finding provides molecular mechanism by which UFMylation maintains YAP stability and exerts an important role in promoting cell senescence, and identified that a previously unrecognized UFMylation is a potential therapeutic target for anti-aging.

Myofibroblasts accumulation contributes to airway remodeling, with the mechanisms being poorly understood. It is steroid-insensitive and has not been therapeutically targeted in asthma. In this study, we explored the potential of yes-associated protein (YAP) as a therapeutic target for myofibroblasts formation in asthma, by revealing the novel role and mechanisms by which YAP activation in type II alveolar epithelial (ATII) cells promotes the fibroblast-to-myofibroblast transition in vitro and in vivo. By performing immunofluorescence staining, we showed that myofibroblasts were increased in the bronchial walls and alveolar parenchyma in clinical asthmatic and house dust mite (HDM)-induced mouse lung samples. This was accompanied by YAP overexpression and nuclear translocation in ATII cells, and connective tissue growth factor (CTGF) upregulation. In vitro, HDM or combination of rhIL-1β with rhTNF-α upregulated and activated YAP in human primary ATII cells and A549 cells, but not in the bronchial epithelial cells, BEAS-2B. This effect was mediated by F-actin polymerization and could be suppressed by pretreatment with latrunculin A but not budesonide. Inhibition of YAP/transcriptional coactivator with PDZ-binding motif (TAZ) in A549 cells by pretreatment with YAP/TAZ siRNA or verteporfin, but not budesonide, impaired the fibroblast-to-myofibroblast transition in vitro. In vivo, verteporfin partly or completely prevented HDM-induced bronchial or alveolar myofibroblast accumulation, and significantly suppressed CTGF expression and collagen deposition in mouse lungs, without profoundly affecting airway inflammation. Our results provide novel mechanistic insights into airway remodeling, and holds promise for the development of novel therapeutic strategies.

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.

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.

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.

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.

Neonatal mammals must rapidly adapt to significant physiological changes during the transition from the intrauterine to extrauterine environments. This adaptation, particularly in the metabolic and respiratory systems, is essential for survival. MicroRNAs (miRNAs) are small noncoding RNAs that regulate various physiological and pathological processes by binding to the 3' untranslated regions of mRNAs. This study aimed to identify miRNAs involved in the early extrauterine adaptation of neonatal piglets and explore their functions. We performed small RNA sequencing on six tissues (heart, liver, spleen, lung, multifidus muscle, and duodenum) from piglets 24 h before birth (day 113 of gestation) and 6 h after birth. A total of 971 miRNA precursors and 1511 mature miRNAs were identified. Tissue-specific expression analysis revealed 881 tissue-specific miRNAs and 164 differentially expressed miRNAs (DE miRNAs) across the tissues. Functional enrichment analysis showed that these DE miRNAs are significantly enriched in pathways related to early extrauterine adaptation, such as the NFκB, PI3K/AKT, and Hippo pathways. Specifically, miR-22-3p was significantly upregulated in the liver post-birth and may regulate the PI3K/AKT pathway by targeting AKT3, promoting gluconeogenesis, and maintaining glucose homeostasis. Dual-luciferase reporter assays and HepG2 cell experiments confirmed AKT3 as a target of miR-22-3p, which activates the AKT/FoxO1 pathway, enhancing gluconeogenesis and glucose production. Furthermore, changes in blood glucose and liver glycogen levels in newborn piglets further support the role of miR-22-3p in glucose homeostasis. This study highlights the importance of miRNAs, particularly miR-22-3p, in the early extrauterine adaptation of neonatal piglets, offering new insights into the physiological adaptation of neonatal mammals.

Amphiregulin (AREG) stimulates human epithelial ovarian cancer (EOC) cell invasion by downregulating E-cadherin expression. YAP is a transcriptional cofactor that has been shown to regulate tumorigenesis. This study aimed to examine whether AREG activates YAP in EOC cells and explore the roles of YAP in AREG-induced downregulation of E-cadherin and cell invasion. Analysis of the Cancer Genome Atlas (TCGA) showed that upregulation of AREG and EGFR were associated with poor survival in human EOC. Treatment of SKOV3 human EOC cells with AREG induced the activation of YAP. In addition, AREG downregulated E-cadherin, upregulated Egr-1 and Slug, and stimulated cell invasion. Using gain- and loss-of-function approaches, we showed that YAP was required for the AREG-upregulated Egr-1 and Slug expression. Furthermore, YAP was also involved in AREG-induced downregulation of E-cadherin and cell invasion. This study provides evidence that AREG stimulates human EOC cell invasion by downregulating E-cadherin expression through the YAP/Egr-1/Slug signaling.

Elevated uptake of saturated fatty acid palmitic acid (PA) is associated with tumor metastasis; however, the precise mechanisms remain partially understood, hindering the development of therapy for PA-driven tumor metastasis. The Hippo-Yes-associated protein (Hippo/YAP) pathway is implicated in cancer progression. Here it is shown that a high-palm oil diet potentiates tumor metastasis in murine xenografts in part through YAP. It is found that the palmitoyltransferase ZDHHC15 is a YAP-regulated gene that forms a feedback loop with YAP. Notably, PA drives the ZDHHC15-YAP feedback loop, thus enforces YAP signaling, and hence promotes tumor metastasis in murine xenografts. In addition, it is shown that ZDHHC15 associates with Kidney and brain protein (KIBRA, also known as WW- and C2 domain-containing protein 1, WWC1), an upstream component of Hippo signaling, and mediates its palmitoylation. KIBRA palmitoylation leads to its degradation and regulates its subcellular localization and activity toward the Hippo/YAP pathway. Moreover, PA enhances KIBRA palmitoylation and degradation. It is further shown that combinatorial targeting of YAP and fatty acid synthesis exhibits augmented effects against metastasis formation in mice fed with a Palm diet. Collectively, these findings uncover a ZDHHC15-YAP feedback loop as a previously unrecognized mechanism underlying PA-promoted tumor metastasis and support targeting YAP and fatty acid synthesis as potential therapeutic targets in PA-driven tumor metastasis.

The present knowledge on hematopoietic stem and progenitor cell (HSPC) biology and aging is based largely on studies in mouse models. Although mouse models are invaluable, they are not without limitations for defining how physical properties of HSPCs and their niche change with age. The bone marrow (BM) niche is a complex, interactive environment with multiple cell types. The structure and organization of the BM niche, especially the extracellular matrix (ECM), change with age. Provided with recent advances in quantitative analytical techniques and in vitro niche models, we have developed novel tools to quantitatively assess the impact of specific biochemical and physical cues on homing, adhesion, and migration of HSPCs. Recent developments in in vitro niche models have also provided new insights into the interactions between HSPCs and their niche, particularly the role of matrix stiffness. Further research is needed to integrate physical biomarkers into comprehensive mathematical models of age-dependent HSPC-niche interactions. The key is to use mouse models in conjunction with direct analyses in in vitro niche models to achieve a more comprehensive understanding of age-dependent alterations in niche function and regulation.

Until now, Hippo pathway-mediated nucleocytoplasmic translocation has been considered the primary mechanism by which yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) transcriptional coactivators regulate cell proliferation and differentiation via transcriptional enhanced associate domain (TEAD)-mediated target gene expression. In this study, however, we found that TAZ, but not YAP, is associated with the Golgi apparatus in macrophages activated via Toll-like receptor ligands during the resolution phase of inflammation. Golgi-associated TAZ enhanced vesicle trafficking and secretion of proinflammatory cytokines in M1 macrophage independent of the Hippo pathway. Depletion of TAZ in tumor-associated macrophages promoted tumor growth by suppressing the recruitment of tumor-infiltrating lymphocytes. Moreover, in a diet-induced metabolic dysfunction-associated steatohepatitis model, macrophage-specific deletion of TAZ ameliorated liver inflammation and hepatic fibrosis. Thus, targeted therapies being developed against YAP/TAZ-TEAD are ineffective in macrophages. Together, our results introduce Golgi-associated TAZ as a potential molecular target for therapeutic intervention to treat tumor progression and chronic inflammatory diseases.

Progressive fibrosis can lead to tissue malfunction and organ failure due to the pathologic accumulation of a collagen-rich extracellular matrix. In vitro models provide useful tools for deconstructing the roles of specific biomechanical or biological mechanisms, such as substrate micro- and nanoscale architecture, in these processes for identifying potential therapeutic targets. Here, we investigated how the mechanosensitive ion channel PIEZO1 influences fibrotic gene and protein expression in adipose-derived stem cells (hASCs). Specifically, we examined the role of PIEZO1 and the mechanosensitive transcription factors YAP/TAZ in sensing aligned or non-aligned substrate architecture to regulate collagen formation. We utilized both 2D microphotopatterned substrates and 3D electrospun polycaprolactone (PCL) substrates to study the role of culture dimensionality. We found that PIEZO1 regulates collagen synthesis in hASCs in a manner that is sensitive to substrate architecture. Activation of PIEZO1 induced significant morphological changes in hASCs, particularly when cultured on aligned substrates, leading to a 30-40 % reduction in cell spreading area and increased cell elongation, in 3D-aligned cultures. Picrosirius Red staining and immunoblotting revealed that PIEZO1 activation reduced collagen accumulation in 3D culture. While YAP translocated to the cytoplasm following PIEZO1 activation, depleting YAP and TAZ did not change collagen expression significantly downstream of PIEZO1 activation, implying that YAP/TAZ translocation from the nucleus and decreased collagen synthesis may be independent consequences of PIEZO1 activation. Our studies demonstrate a role for PIEZO1 in cellular mechanosensing of substrate architecture and provide targetable pathways for treating fibrosis and for enhancing tissue-engineered and regenerative approaches for fibrous tissue repair. STATEMENT OF SIGNIFICANCE: This study examines how cells sense and respond to their physical environment via PIEZO1 mechanotransduction. We discovered that cells use PIEZO1 to detect the alignment of surrounding structures, influencing the production of collagen - a key component in fibrosis. Our study used both 2D and 3D models to mimic different tissue environments, providing new insights into how cellular responses change in more complex settings. Importantly, we found that activating PIEZO1 alters cell shape and collagen production, especially on aligned surfaces. Interestingly, while PIEZO1 activation caused YAP translocation to the cytoplasm, this translocation did not directly affect collagen production. This work advances our understanding of fibrosis development and identifies PIEZO1 as a potential target for new therapies.

Cellular behavior is strongly influenced by mechanical signals in the surrounding microenvironment, along with external factors such as temperature fluctuations, changes in blood flow, and muscle activity, etc. These factors are key in shaping cellular states and can contribute to the development of various diseases. In the realm of rehabilitation physical therapies, therapeutic exercise and manual treatments, etc., are frequently employed, not just for pain relief but also to support recovery from diverse health conditions. However, the detailed molecular pathways through which these therapies interact with tissues and influence gene expression are not yet fully understood. The identification of YAP has been instrumental in closing this knowledge gap. YAP is known for its capacity to perceive and translate mechanical signals into specific transcriptional programs within cells. This insight has opened up new perspectives on how physical and rehabilitation medicine may exert its beneficial effects. The review investigates the involvement of the Hippo/YAP signaling pathway in various diseases and considers how different rehabilitation techniques leverage this pathway to aid in healing. Additionally, it examines the therapeutic potential of modulating the Hippo/YAP pathway within the context of rehabilitation, while also addressing the challenges and controversies that surround its use in physical and rehabilitation medicine.

The tumor microenvironment (TME) comprises a heterogenous cell population within a complex three-dimensional (3D) extracellular matrix (ECM). Stromal cells within this TME are altered by signaling cues from cancer cells to support uncontrolled tumor growth and invasion events. Moreover, the ECM also plays a fundamental role in tumor development through pathological remodeling, stiffening and interaction with TME cells. In healthy tissues, Hippo signaling pathway actively contributes to tissue growth, cell proliferation and apoptosis. However, in cancer, the Hippo signaling pathway is highly dysregulated, leading to nuclear translocation of the YAP/TAZ complex, which directly contributes to uncontrolled cell proliferation and tissue growth, and ECM remodeling and stiffening processes. Here, we compare the effect of increasing cell culture substrate stiffness, derived from tumor progression, upon the dysregulation of the Hippo signaling pathway in colorectal cancer-associated fibroblasts (CAFs) and normal colorectal fibroblasts (NFs). We correlate the dysregulation of Hippo pathway with the magnitude of the traction forces exerted by healthy and malignant stromal cells. We found that ECM stiffening is crucial in Hippo pathway dysregulation in CAFs, but not in normal fibroblasts.

Mechanisms underlying bile duct injury in biliary atresia (BA) remain unclear and mechanisms of bile duct repair are unknown. This study aimed to explore the roles of microtubule instability and Wnt and Hippo signaling pathways in a biliatresone-induced BA model.

Using primary murine neonatal cholangiocytes in both 2D and 3D cultures, and ex-vivo extra hepatic bile ducts (EHBD) which also has peri-cholangiocyte area, we analyzed injury and recovery processes. Injury was induced by the toxin biliatresone and recovery was induced by toxin wash-out.

Microtubule stabilizer paclitaxel prevented biliatresone-induced injury, both to cholangiocytes as well as reduced periductal αSMA stain, this process is mediated by decreased glutathione levels. RhoU and Wnt11 (Wnt signaling) and Pard6g and Amotl1 (Hippo signaling) are involved in both injury and recovery processes, with the latter acting upstream to Wnt signaling.

Early stages of biliatresone-induced EHBD injury in cholangiocytes and periductal structures are reversible. Wnt and Hippo signaling pathways play crucial roles in injury and recovery, providing insights into BA injury mechanisms and potential recovery avenues.

Microtubule stabilization prevents cholangiocyte injury and lumen obstruction in a toxic model of biliary atresia (biliatresone induced). Early stages of biliatresone-induced injury, affecting both cholangiocytes and periductal structures, are reversible. Both Wnt and Hippo signaling pathways play a crucial role in bile duct injury and recovery, with a noted interplay between the two. Understanding mechanisms of cholangiocyte recovery is imperative to unveil potential therapeutic avenues.

The evolutionarily conserved Hippo pathway plays a pivotal role in governing a variety of biological processes. Heart failure (HF) is a major global health problem with a significant risk of mortality. This review provides a contemporary understanding of the Hippo pathway in regulating different cell types during HF. Through a systematic analysis of each component's regulatory mechanisms within the Hippo pathway, we elucidate their specific effects on cardiomyocytes, fibroblasts, endothelial cells, and macrophages in response to various cardiac injuries. Insights gleaned from both in vitro and in vivo studies highlight the therapeutic promise of targeting the Hippo pathway to address cardiovascular diseases, particularly HF.

Transcriptional coactivator with PDZ-binding motif (TAZ), a Hippo signaling pathway effector, maintains the balance of cell proliferation, differentiation, and death. However, the role of TAZ in tubular cell survival and acute kidney injury (AKI) remains largely unknown.

We used the RNA-seq database, Western blot, and immunohistochemistry to examine TAZ expression in kidneys from cisplatin-induced AKI. We generated tubular-specific TAZ knockout mice to assess the role of TAZ in cisplatin-induced renal toxicity. Immunoprecipitation-mass spectrometry followed standard procedures.

TAZ was activated in tubular cells in kidneys injected with cisplatin. Conditional deletion of TAZ in tubular cells confers ferroptosis resistance and protects kidneys from cisplatin-induced AKI, whereas overexpression of TAZ(S89A) exacerbates cisplatin-induced ferroptosis. Inhibition of ferroptosis with ferrostatin-1 potently preserves renal function and alleviates morphological injury and tubular cell ferroptosis induced by cisplatin. Mechanistically, in a PPARδ-dependent manner, but not TEAD, TAZ reduces the expression of glutathione peroxidase 4 (GPX4), thus exacerbating cisplatin-induced ferroptosis.

Our findings show that cisplatin-induced AKI and tubular cell ferroptosis are mediated by TAZ-PPARδ interaction through regulation of GPX4, highlighting TAZ as a potential therapeutic candidate for AKI.

As one of the most prevalent malignant neoplasms among women globally, the optimization of therapeutic strategies for breast cancer has perpetually been a research hotspot. The tumor microenvironment (TME) is of paramount importance in the progression of breast cancer, among which the extracellular matrix (ECM) and hypoxia are two crucial factors. The alterations of these two factors are predominantly regulated by the Hippo signaling pathway, which promotes tumor invasiveness, metastasis, therapeutic resistance, and susceptibility. Hence, this review focuses on the Hippo pathway in breast cancer, specifically, how the ECM and hypoxia impact the biological traits and therapeutic responses of breast cancer. Moreover, the role of miRNAs in modulating ECM constituents was investigated, and hsa-miR-33b-3p was identified as a potential therapeutic target for breast cancer. The review provides theoretical foundations and potential therapeutic direction for clinical treatment strategies in breast cancer, with the aspiration of attaining more precise and effective treatment alternatives in the future.

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.

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.

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.

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.

The transcriptional coactivator Yes-associated protein (YAP)/transcriptional co-activator with PDZ binding motif (TAZ) induces cell proliferation through nuclear localization at low cell density. Conversely, at extremely high cell density, the Hippo pathway, which regulates YAP/TAZ, is activated. This activation leads to the translocation of YAP/TAZ into the cytoplasm, resulting in cell cycle arrest. Various cancer cells have several times more YAP/TAZ than normal cells. However, it is not entirely clear whether this several-fold increase in YAP/TAZ alone is sufficient to overcome proliferation inhibition (contact inhibition) under high-density conditions, thereby allowing continuous proliferation. In this study, we construct a three-dimensional (3D) mathematical model of cell proliferation incorporating the Hippo-YAP/TAZ pathway. Herein, a significant innovation in our approach is the introduction of a novel modeling component that inputs cell density, which reflects cell dynamics, into the Hippo pathway and enables the simulation of cell proliferation as the output response. We assume such 3D model with cell-cell interactions by solving reaction and molecular dynamics (MD) equations by applying adhesion and repulsive forces that act between cells and frictional forces acting on each cell. We assume Lennard-Jones (12-6) potential with a softcore character so that each cell secures its exclusive domain. We set cell cycles composed of mitotic and cell growth phases in which cells divide and grow under the influence of cell kinetics. We perform mathematical simulations at various YAP/TAZ levels to investigate the extent of YAP/TAZ increase required for sustained proliferation at high density. The results show that a twofold increase in YAP/TAZ levels of cancer cells was sufficient to evade cell cycle arrest compared to normal cells, enabling cells to continue proliferating even under high-density conditions. Finally, this mathematical model, which incorporates cell-cell interactions and the Hippo-YAP/TAZ pathway, may be applicable for evaluating cancer malignancy based on YAP/TAZ levels, developing drugs to suppress the abnormal proliferation of cancer cells, and determining appropriate drug dosages. The source codes are freely available.

This review outlines some of the many approaches taken over a decade or more to repair damaged hearts. We showcase the recent breakthroughs in organ regeneration elicited by reprogramming factors OCT3/4, SOX2, KLF4, and C-MYC (OKSM). Transient OKSM transgene expression rejuvenated senescent organs in mice. OKSM transgenes also caused murine heart cell regeneration. A triplet alanine mutation of the N-terminus of Serum Response Factor's MADS box SRF153(A3), termed STEMIN, and the YAP mutant, YAP5SA synergized and activated OKSM and NANOG in adult rat cardiac myocytes; thus, causing rapid nuclear proliferation and blocked myocyte differentiation. In addition, ATAC seq showed induced expression of growth factor genes FGFs, BMPs, Notchs, IGFs, JAK, STATs and non-canonical Wnts. Injected STEMIN and YAP5SA synthetic modifying mRNA (mmRNA) into infarcted adult mouse hearts, brought damaged hearts back to near normal contractility without severe fibrosis. Thus, STEMIN and YAP5SA mmRNA may exert additional regenerative potential than OKSM alone for treating heart diseases.

Ovarian cancer, a malignant tumor that poses a significant threat to women's health, has seen a rise in incidence, prompting the urgent need for more effective treatment. This study primarily aimed to explore the potential of bovine collagen peptides in inhibiting ovarian cancer. The investigation in this study began with the identification of 268 peptide sequences through LC-MS/MS, followed by a screening process using molecular docking techniques to identify potential peptides capable of binding to EGFR. Subsequently, a series of experiments were performed, demonstrating the inhibitory effects of the peptide GPAGADGDRGEAGPAGPAGPAGPR on the proliferation of ovarian cancer cells. Transcriptomic analysis further revealed that this peptide can regulate cholesterol metabolism in ovarian cancer cells. Finally, a combination of time-resolved fluorescence resonance energy transfer, isothermal titration calorimetry, molecular docking, and molecular dynamics simulations were utilized to validate the ability of this peptide to bind to the epidermal growth factor receptor (EGFR) and impede the binding of epidermal growth factor (EGF) and EGFR.

Bladder fibrosis is the final common pathway of neurogenic bladder (NB), and its underlying mechanisms are not fully understood. The current study aims to evaluate the involvement of Piezo1, a mechanosensitive channel, in bladder fibrosis. A full-thickness bladder specimen was taken during ileocystoplasty or ureteral reimplantation from the surgical cut's edge. By chopping off the bilateral lumbar 6 (L6) and sacral 1 (S1) spinal nerves, NB rat models were produced. Utilizing both pharmacological inhibition and Piezo1 deletion, the function of Piezo1 in the TGF-β1-induced fibrosis model of SV-HUC-1 cells was delineated. RNA-seq, immunofluorescence, immunohistochemistry (IHC), and Western blotting were used to evaluate the degrees of fibrosis and biochemical signaling pathways. Piezo1 protein expression was noticeably elevated in the human NB bladder. The abundance of Piezo1 protein in bladder of NB rats was significantly increased. RNA-seq analysis revealed that the ECM-receptor interaction signaling pathway and collagen-containing ECM were increased in spinal cord injury (SCI)-induced bladder fibrosis. Moreover, the bladder of the NB rat model showed activation of YAP1 and TGF-β1/Smad. In SV-HUC-1 cells, siRNA suppression of Piezo1 led to profibrotic responses and activation of the TGF-β1/Smad pathway. However, Yoda1, a Piezo1-specific agonist, significantly reduced these effects. TGF-β1 increased Piezo1 activation and profibrotic responses in SV-HUC-1 cells. In the TGF-β1-induced fibrosis model of SV-HUC-1 cells, the TGF-β1/Smad pathway was activated, whereas the Hippo/YAP1 signal pathway was blocked. Inhibition of Piezo1 further prevented this process. Piezo1 is involved in the progression of NB bladder fibrosis and profibrotic alterations in SV-HUC-1 cells, likely through regulating the TGF-β1/Smad and Hippo/YAP1 pathways.

Mutations of human TBC1D24 are associated with deafness, epilepsy, or DOORS syndrome (deafness, onychodystrophy, osteodystrophy, cognitive disability, and seizures). The causal relationships between TBC1D24 variants and the different clinical phenotypes are not understood. Our hypothesis is that phenotypic heterogeneity of missense mutations of TBC1D24 results, in part, from perturbed binding of different protein partners. To discover novel protein partners of TBC1D24, we conducted yeast two-hybrid (Y2H) screen using mouse full-length TBC1D24 as bait. Kidney and brain protein (KIBRA), a scaffold protein encoded by Wwc1, was identified as a partner of TBC1D24. KIBRA functions in the Hippo signaling pathway and is important for human cognition and memory. The TBC1D24 TLDc domain binds to KIBRA full-length and to its C2 domain, confirmed by Y2H assays. No interaction was detected with Y2H assays between the KIBRA C2 domain and TLDc domains of NCOA7, MEAK7, and OXR1. Moreover, the C2 domains of other WWC family proteins do not interact with the TLDc domain of TBC1D24, demonstrating specificity. The mRNAs encoding TBC1D24 and KIBRA proteins in mouse are coexpressed at least in a subset of hippocampal cells indicating availability to interact in vivo. As two epilepsy-associated recessive variants (Gly511Arg and Ala515Val) in the TLDc domain of human TBC1D24 disrupt the interaction with the human KIBRA C2 domain, this study reveals a pathogenic mechanism of TBC1D24-associated epilepsy, linking the TBC1D24 and KIBRA pathways. The interaction of TBC1D24-KIBRA is physiologically meaningful and necessary to reduce the risk of epilepsy.

In solid tumors such as hepatocellular carcinoma (HCC), hypoxia is one of the important mechanisms of cancer development that closely influences cancer development, survival, and metastasis. The development of treatments for cancer was temporarily revolutionized by immunotherapy but continues to be constrained by limited response rates and the resistance and high costs required for the development of new and innovative strategies. In particular, solid tumors, including HCC, a multi-vascular tumor type, are sensitive to hypoxia and generate many blood vessels for metastasis and development, making it difficult to treat HCC, not only with immunotherapy but also with drugs targeting blood vessels. Therefore, in order to develop a treatment strategy for hypoxic tumors, various mechanisms must be explored and analyzed to treat these impregnable solid tumors. To date, tumor growth mechanisms linked to hypoxia are known to be complex and coexist with various signal pathways, but recently, mechanisms related to the Hippo signal pathway are emerging. Interestingly, Hippo YAP/TAZ, which appear during early tumor and normal tumor growth, and YAP/TAZ, which appear during hypoxia, help tumor growth and proliferation in different directions. Peculiarly, YAP/TAZ, which have different phosphorylation directions in the hypoxic environment of tumors, are involved in cancer proliferation and metastasis in various carcinomas, including HCC. Analyzing the mechanisms that regulate the function and expression of YAP in addition to HIF in the complex hypoxic environment of tumors may lead to a variety of anti-cancer strategies and combining HIF and YAP/TAZ may develop the potential to change the landscape of cancer treatment.

The transcriptional coactivator Yorkie (Yki) regulates organ size by promoting cell proliferation. It is unclear how cells control Yki activity when exposed to harmful stimuli such as oxidative stress. In this study, we show that oxidative stress inhibits the binding of Yki to Scalloped (Sd) but promotes the interaction of Yki with another transcription factor, forkhead box O (Foxo), ultimately leading to a halt in cell proliferation. Mechanistically, Foxo normally exhibits a low binding affinity for Yki, allowing Yki to form a complex with Sd and activate proliferative genes. Under oxidative stress, Usp7 deubiquitinates Foxo to promote its interaction with Yki, thereby activating the expression of proliferation suppressors. Finally, we show that Yki is essential for Drosophila survival under oxidative stress. In summary, these findings suggest that oxidative stress reprograms Yki from a proliferation-promoting factor to a proliferation suppressor, forming a self-protective mechanism.

Metastasis is a crucial stage in tumour progression, and cancer-associated fibroblasts (CAFs) support metastasis through their participation in extracellular matrix (ECM) stiffness. CD248 is a possible biomarker for non-small cell lung cancer (NSCLC)-derived CAFs, but its role in mediating ECM stiffness to promote NSCLC metastasis is unknown. We investigated the significance of CD248+ CAFs in activating the Hippo axis and promoting connective tissue growth factor (CTGF) expression, which affects the stromal collagen I environment and improves ECM stiffness, thereby facilitating NSCLC metastasis. In this study, we found that higher levels of CD248 in CAFs induced the formation of collagen I, which in turn increased extracellular matrix stiffness, thereby enabling NSCLC cell infiltration and migration. Hippo axis activation by CD248+ CAFs induces CTGF expression, which facilitates the formation of the collagen I milieu in the stromal matrix. In a tumour lung metastasis model utilizing fibroblast-specific CD248 gene knockout mice, CD248 gene knockout mice showed a significantly reduced ability to develop tumour lung metastasis compared to that of WT mice. Our findings demonstrate that CD248+ CAFs activate the Hippo pathway, thereby inducing CTGF expression, which in turn facilitates the collagen I milieu of the stromal matrix, which promotes NSCLC metastasis.