LATS Kinases Research Articles

A ZO-2 scaffolding mechanism regulates the Hippo signalling pathway.

Contact inhibition of proliferation is a critical cell density control mechanism governed by the Hippo signalling pathway. The biochemical signalling underlying cell density-dependent cues regulating Hippo signalling and its downstream effectors, YAP, remains poorly understood. Here, we reveal that the tight junction protein ZO-2 is required for the contact-mediated inhibition of proliferation. We additionally determined that the well-established molecular players of this process, namely Hippo kinase LATS1 and YAP, are regulated by ZO-2 and that the scaffolding function of ZO-2 promotes the interaction with and phosphorylation of YAP by LATS1. Mechanistically, YAP is phosphorylated when ZO-2 brings LATS1 and YAP together via its SH3 and PDZ domains, respectively, subsequently leading to the cytoplasmic retention and inactivation of YAP. In conclusion, we demonstrate that ZO-2 maintains Hippo signalling pathway activation by promoting the stability of LATS1 to inactivate YAP.

HPV18 E7 inhibits LATS1 kinase and activates YAP1 by degrading PTPN14.

High-risk human papillomavirus (HPV) oncoproteins inactivate cellular tumor suppressors to reprogram host cell signaling pathways. HPV E7 proteins bind and degrade the tumor suppressor PTPN14, thereby promoting the nuclear localization of the YAP1 oncoprotein and inhibiting keratinocyte differentiation. YAP1 is a transcriptional coactivator that drives epithelial cell stemness and self-renewal. YAP1 activity is inhibited by the highly conserved Hippo pathway, which is frequently inactivated in human cancers. MST1/2 and LATS1/2 kinases form the core of the Hippo kinase cascade. Active LATS1 kinase is phosphorylated on threonine 1079 and inhibits YAP1 by phosphorylating it on amino acids including serine 127. Here, we tested the effect of high-risk (carcinogenic) HPV18 E7 on Hippo pathway activity. We found that either PTPN14 knockout or PTPN14 degradation by HPV18 E7 decreased the phosphorylation of LATS1 T1079 and YAP1 S127 in human keratinocytes and inhibited keratinocyte differentiation. Conversely, PTPN14-dependent differentiation required LATS kinases and certain PPxY motifs in PTPN14. Neither MST1/2 kinases nor the putative PTPN14 phosphatase active sites were required for PTPN14 to promote differentiation. Together, these data support that PTPN14 inactivation or degradation of PTPN14 by HPV18 E7 reduce LATS1 activity, promoting active YAP1 and inhibiting keratinocyte differentiation.IMPORTANCEThe Hippo kinase cascade inhibits YAP1, an oncoprotein and driver of cell stemness and self-renewal. There is mounting evidence that the Hippo pathway is targeted by tumor viruses including human papillomavirus. The high-risk HPV E7 oncoprotein promotes YAP1 nuclear localization and the carcinogenic activity of high-risk HPV E7 requires YAP1 activity. Blocking HPV E7-dependent YAP1 activation could inhibit HPV-mediated carcinogenesis, but the mechanism by which HPV E7 activates YAP1 has not been elucidated. Here we report that by degrading the tumor suppressor PTPN14, HPV18 E7 inhibits LATS1 kinase, reducing inhibitory phosphorylation on YAP1. These data support that an HPV oncoprotein can inhibit Hippo signaling to activate YAP1 and strengthen the link between PTPN14 and Hippo signaling in human epithelial cells.

Emerging Role of Hippo-YAP (Yes-Associated Protein)/TAZ (Transcriptional Coactivator with PDZ-Binding Motif) Pathway Dysregulation in Renal Cell Carcinoma Progression.

Although Hippo-YAP/TAZ pathway involvement has been extensively studied in the development of certain cancers, the involvement of this cascade in kidney cancer progression is not well-established and, therefore, will be the focus of this review. Renal cell carcinoma (RCC), the most prevalent kidney tumor subtype, has a poor prognosis and a high mortality rate. Core Hippo signaling inactivation (e.g., LATS kinases) leads to the nuclear translocation of YAP/TAZ where they bind to co-transcriptional factors such as TEAD promoting transcription of genes which initiates various fibrotic and neoplastic diseases. Loss of expression of LATS1/2 kinase and activation of YAP/TAZ correlates with poor survival in RCC patients. Renal-specific ablation of LATS1 in mice leads to the spontaneous development of several subtypes of RCC in a YAP/TAZ-dependent manner. Genetic and pharmacological inactivation of YAP/TAZ reverses the oncogenic potential in LATS1-deficient mice, highlighting the therapeutic benefit of network targeting in RCC. Here, we explore the unique upstream controls and downstream consequences of the Hippo-YAP/TAZ pathway deregulation in renal cancer. This review critically evaluates the current literature on the role of the Hippo pathway in RCC progression and highlights the recent scientific evidence designating YAP/TAZ as novel therapeutic targets against kidney cancer.

Hippo pathway-mediated YAP1/TAZ inhibition is essential for proper pancreatic endocrine specification and differentiation.

The Hippo pathway plays a central role in tissue development and homeostasis. However, the function of Hippo in pancreatic endocrine development remains obscure. Here, we generated novel conditional genetically engineered mouse models to examine the roles of Hippo pathway-mediated YAP1/TAZ inhibition in the development stages of endocrine specification and differentiation. While YAP1 protein was localized to the nuclei in bipotent progenitor cells, Neurogenin 3 expressing endocrine progenitors completely lost YAP1 expression. Using genetically engineered mouse models, we found that inactivation of YAP1 requires both an intact Hippo pathway and Neurogenin 3 protein. Gene deletion of Lats1 and 2 kinases (Lats1&2) in endocrine progenitor cells of developing mouse pancreas using Neurog3Cre blocked endocrine progenitor cell differentiation and specification, resulting in reduced islets size and a disorganized pancreas at birth. Loss of Lats1&2 in Neurogenin 3 expressing cells activated YAP1/TAZ transcriptional activity and recruited macrophages to the developing pancreas. These defects were rescued by deletion of Yap1/Wwtr1 genes, suggesting that tight regulation of YAP1/TAZ by Hippo signaling is crucial for pancreatic endocrine specification. In contrast, deletion of Lats1&2 using β-cell-specific Ins1CreER resulted in a phenotypically normal pancreas, indicating that Lats1&2 are indispensable for differentiation of endocrine progenitors but not for that of β-cells. Our results demonstrate that loss of YAP1/TAZ expression in the pancreatic endocrine compartment is not a passive consequence of endocrine specification. Rather, Hippo pathway-mediated inhibition of YAP1/TAZ in endocrine progenitors is a prerequisite for endocrine specification and differentiation.

HPV18 E7 inhibits LATS1 kinase and activates YAP1 by degrading PTPN14.

High-risk human papillomavirus (HPV) oncoproteins inactivate cellular tumor suppressors to reprogram host cell signaling pathways. HPV E7 proteins bind and degrade the tumor suppressor PTPN14, thereby promoting the nuclear localization of the YAP1 oncoprotein and inhibiting keratinocyte differentiation. YAP1 is a transcriptional coactivator that drives epithelial cell stemness and self-renewal. YAP1 activity is inhibited by the highly conserved Hippo pathway, which is frequently inactivated in human cancers. MST1/2 and LATS1/2 kinases form the core of the Hippo kinase cascade. Active LATS1 kinase is phosphorylated on threonine 1079 and inhibits YAP1 by phosphorylating it on amino acids including serine 127. Here, we tested the effect of high-risk (carcinogenic) HPV18 E7 on Hippo pathway activity. We found that either PTPN14 knockout or PTPN14 degradation by HPV18 E7 decreased phosphorylation of LATS1 T1079 and YAP1 S127 in human keratinocytes and inhibited keratinocyte differentiation. Conversely, PTPN14-dependent differentiation required LATS kinases and certain PPxY motifs in PTPN14. Neither MST1/2 kinases nor the putative PTPN14 phosphatase active site were required for PTPN14 to promote differentiation. Taken together, these data support that PTPN14 inactivation or degradation of PTPN14 by HPV18 E7 reduce LATS1 activity, promoting active YAP1 and inhibiting keratinocyte differentiation.

Phytic acid inhibits RafGOFScrib−/− tumor growth and invasion by suppressing the Yki-mediated JAK/STAT pathway in Drosophila melanogaster

Metastasis is one of the most important factors related to malignant tumor development and therapeutic failure. Phytic acid (PA), a poly-phosphorylated inositol derivative in plant seeds and grains, has been shown to have antitumoral activity. However, the effect of PA on tumor metastasis and the underlying mechanisms remain uncharacterized. In the current study, we aimed to identify the effect of PA on tumor metastasis by employing a Drosophila model of malignant tumor RafGOFScrib−/−. We observed that PA supplementation in food inhibited the invasion and migration of tumors. Further studies indicated that PA drives Yki phosphorylation and inactivation through Lats kinase, which subsequently results in decreased expression of the JAK/STAT pathway ligands unpaired cytokines (Upds). Moreover, the reduced JAK/STAT pathway inhibits the recruitment and proliferation of hemocytes. To summarize, these findings provide valuable pathological and mechanistic insights into the potential application of PA for functional food or natural medicine development.

Inhibiting Hippo pathway kinases releases WWC1 to promote AMPAR-dependent synaptic plasticity and long-term memory in mice.

The localization, number, and function of postsynaptic AMPA-type glutamate receptors (AMPARs) are crucial for synaptic plasticity, a cellular correlate for learning and memory. The Hippo pathway member WWC1 is an important component of AMPAR-containing protein complexes. However, the availability of WWC1 is constrained by its interaction with the Hippo pathway kinases LATS1 and LATS2 (LATS1/2). Here, we explored the biochemical regulation of this interaction and found that it is pharmacologically targetable in vivo. In primary hippocampal neurons, phosphorylation of LATS1/2 by the upstream kinases MST1 and MST2 (MST1/2) enhanced the interaction between WWC1 and LATS1/2, which sequestered WWC1. Pharmacologically inhibiting MST1/2 in male mice and in human brain-derived organoids promoted the dissociation of WWC1 from LATS1/2, leading to an increase in WWC1 in AMPAR-containing complexes. MST1/2 inhibition enhanced synaptic transmission in mouse hippocampal brain slices and improved cognition in healthy male mice and in male mouse models of Alzheimer's disease and aging. Thus, compounds that disrupt the interaction between WWC1 and LATS1/2 might be explored for development as cognitive enhancers.

Identification of PTPN12 Phosphatase as a Novel Negative Regulator of Hippo Pathway Effectors YAP/TAZ in Breast Cancer.

The Hippo pathway plays crucial roles in governing various biological processes during tumorigenesis and metastasis. Within this pathway, upstream signaling stimuli activate a core kinase cascade, involving MST1/2 and LATS1/2, that subsequently phosphorylates and inhibits the transcriptional co-activators YAP and its paralog TAZ. This inhibition modulates the transcriptional regulation of downstream target genes, impacting cell proliferation, migration, and death. Despite the acknowledged significance of protein kinases in the Hippo pathway, the regulatory influence of protein phosphatases remains largely unexplored. In this study, we conducted the first gain-of-functional screen for protein tyrosine phosphatases (PTPs) regulating the Hippo pathway. Utilizing a LATS kinase biosensor (LATS-BS), a YAP/TAZ activity reporter (STBS-Luc), and a comprehensive PTP library, we identified numerous novel PTPs that play regulatory roles in the Hippo pathway. Subsequent experiments validated PTPN12, a master regulator of oncogenic receptor tyrosine kinases (RTKs), as a previously unrecognized negative regulator of the Hippo pathway effectors, oncogenic YAP/TAZ, influencing breast cancer cell proliferation and migration. In summary, our findings offer valuable insights into the roles of PTPs in the Hippo signaling pathway, significantly contributing to our understanding of breast cancer biology and potential therapeutic strategies.

LATS1 controls CTCF chromatin occupancy and hormonal response of 3D-grown breast cancer cells

The cancer epigenome has been studied in cells cultured in two-dimensional (2D) monolayers, but recent studies highlight the impact of the extracellular matrix and the three-dimensional (3D) environment on multiple cellular functions. Here, we report the physical, biochemical, and genomic differences between T47D breast cancer cells cultured in 2D and as 3D spheroids. Cells within 3D spheroids exhibit a rounder nucleus with less accessible, more compacted chromatin, as well as altered expression of ~2000 genes, the majority of which become repressed. Hi-C analysis reveals that cells in 3D are enriched for regions belonging to the B compartment, have decreased chromatin-bound CTCF and increased fusion of topologically associating domains (TADs). Upregulation of the Hippo pathway in 3D spheroids results in the activation of the LATS1 kinase, which promotes phosphorylation and displacement of CTCF from DNA, thereby likely causing the observed TAD fusions. 3D cells show higher chromatin binding of progesterone receptor (PR), leading to an increase in the number of hormone-regulated genes. This effect is in part mediated by LATS1 activation, which favors cytoplasmic retention of YAP and CTCF removal.

NIBR-LTSi is a selective LATS kinase inhibitor activating YAP signaling and expanding tissue stem cells in vitro and in vivo

The YAP/Hippo pathway is an organ growth and size regulation rheostat safeguarding multiple tissue stem cell compartments. LATS kinases phosphorylate and thereby inactivate YAP, thus representing a potential direct drug target for promoting tissue regeneration. Here, we report the identification and characterization of the selective small-molecule LATS kinase inhibitor NIBR-LTSi. NIBR-LTSi activates YAP signaling, shows good oral bioavailability, and expands organoids derived from several mouse and human tissues. In tissue stem cells, NIBR-LTSi promotes proliferation, maintains stemness, and blocks differentiation invitro and invivo. NIBR-LTSi accelerates liver regeneration following extended hepatectomy in mice. However, increased proliferation and cell dedifferentiation in multiple organs prevent prolonged systemic LATS inhibition, thus limiting potential therapeutic benefit. Together, we report a selective LATS kinase inhibitor agonizing YAP signaling and promoting tissue regeneration invitro and invivo, enabling future research on the regenerative potential of the YAP/Hippo pathway.

The ability of the LIMD1 and TRIP6 LIM domains to bind strained f-actin is critical for their tension dependent localization to adherens junctions and association with the Hippo pathway kinase LATS1.

A key step in regulation of Hippo pathway signaling in response to mechanical tension is recruitment of the LIM domain proteins TRIP6 and LIMD1 to adherens junctions. Mechanical tension also triggers TRIP6 and LIMD1 to bind and inhibit the Hippo pathway kinase LATS1. How TRIP6 and LIMD1 are recruited to adherens junctions in response to tension is not clear, but previous studies suggested that they could be regulated by the known mechanosensory proteins α-catenin and vinculin at adherens junctions. We found that the three LIM domains of TRIP6 and LIMD1 are necessary and sufficient for tension-dependent localization to adherens junctions. The LIM domains of TRIP6, LIMD1, and certain other LIM domain proteins have been shown to bind to actin networks under strain/tension. Consistent with this, we show that TRIP6 and LIMD1 colocalize with the ends of actin fibers at adherens junctions. Point mutations in a key conserved residue in each LIM domain that are predicted to impair binding to f-actin under strain inhibits TRIP6 and LIMD1 localization to adherens junctions and their ability to bind to and recruit LATS1 to adherens junctions. Together these results show that the ability of TRIP6 and LIMD1 to bind to strained actin underlies their ability to localize to adherens junctions and regulate LATS1 in response to mechanical tension.

Inhibition of LATS kinases reduces tumorigenicity and increases the sensitivity of human chronic myelogenous leukemia cells to imatinib

Chronic myelogenous leukemia (CML) is a clonal hematologic malignancy of the myeloid lineage caused by the oncogenic BCR/ABL fusion protein that promotes CML cell proliferation and protects them against drug-induced apoptosis. In this study, we determine LATS1 and LATS2 expression in CML cells derived from patients who are resistant to imatinib (IM) treatment. Significant upregulation of LATS1 and LATS2 was found in these CML patients compared to healthy donors. To further explore whether the expression of LATS1/2 contributes to the IM-resistant phenotype, IM-resistant CML cell lines generated by culturing CML-derived erythroblastic K562 cells in increasing concentrations of IM were used as in vitro models. Up-regulation of LATS1 and LATS2 was observed in IM-resistant K562 cells. Reduction of LATS using either Lats-IN-1 (TRULI), a specific LATS inhibitor, or shRNA targeting LATS1/2 significantly reduced clonogenicity, increased apoptosis and induced differentiation of K562 cells to late-stage erythroid cells. Furthermore, depletion of LATS1 and LATS2 also increased the sensitivity of K562 cells to IM. Taken together, our results suggest that LATS could be one of the key factors contributing to the rapid proliferation, reduced apoptosis, and IM resistance of CML cells. Targeting LATS could be a promising treatment to enhance the therapeutic effect of a conventional BCR/ABL tyrosine kinase inhibitor such as IM.

Efficient Reprogramming of Mouse Embryonic Stem Cells into Trophoblast Stem-like Cells via Lats Kinase Inhibition.

Mouse zygotes undergo multiple rounds of cell division, resulting in the formation of preimplantation blastocysts comprising three lineages: trophectoderm (TE), epiblast (EPI), and primitive endoderm (PrE). Cell fate determination plays a crucial role in establishing a healthy pregnancy. The initial separation of lineages gives rise to TE and inner cell mass (ICM), from which trophoblast stem cells (TSC) and embryonic stem cells (ESC) can be derived in vitro. Studying lineage differentiation is greatly facilitated by the clear functional distinction between TSC and ESC. However, transitioning between these two types of cells naturally poses challenges. In this study, we demonstrate that inhibiting LATS kinase promotes the conversion of ICM to TE and also effectively reprograms ESC into stable, self-renewing TS-like cells (TSLC). Compared to TSC, TSLC exhibits similar molecular properties, including the high expression of marker genes such as Cdx2, Eomes, and Tfap2c, as well as hypomethylation of their promoters. Importantly, TSLC not only displays the ability to differentiate into mature trophoblast cells in vitro but also participates in placenta formation in vivo. These findings highlight the efficient reprogramming of ESCs into TSLCs using a small molecular inducer, which provides a new reference for understanding the regulatory network between ESCs and TSCs.

Unveiling the mechanistic link between extracellular amyloid fibrils, mechano-signaling and YAP activation in cancer

The tumor microenvironment is a complex ecosystem that plays a critical role in cancer progression and treatment response. Recently, extracellular amyloid fibrils have emerged as novel components of the tumor microenvironment; however, their function remains elusive. In this study, we establish a direct connection between the presence of amyloid fibrils in the secretome and the activation of YAP, a transcriptional co-activator involved in cancer proliferation and drug resistance. Furthermore, we uncover a shared mechano-signaling mechanism triggered by amyloid fibrils in both melanoma and pancreatic ductal adenocarcinoma cells. Our findings highlight the crucial role of the glycocalyx protein Agrin which binds to extracellular amyloid fibrils and acts as a necessary factor in driving amyloid-dependent YAP activation. Additionally, we reveal the involvement of the HIPPO pathway core kinase LATS1 in this signaling cascade. Finally, we demonstrate that extracellular amyloid fibrils enhance cancer cell migration and invasion. In conclusion, our research expands our knowledge of the tumor microenvironment by uncovering the role of extracellular amyloid fibrils in driving mechano-signaling and YAP activation. This knowledge opens up new avenues for developing innovative strategies to modulate YAP activation and mitigate its detrimental effects during cancer progression.

YAP governs cellular adaptation to perturbation of glutamine metabolism by regulating ATF4-mediated stress response.

Proliferating cells have metabolic dependence on glutamine to fuel anabolic pathways and to refill the mitochondrial carbon pool. The Hippo pathway is essential for coordinating cell survival and growth with nutrient availability, but no molecular connection to glutamine deprivation has been reported. Here, we identify a non-canonical role of YAP, a key effector of the Hippo pathway, in cellular adaptation to perturbation of glutamine metabolism. Whereas YAP is inhibited by nutrient scarcity, enabling cells to restrain proliferation and to maintain energy homeostasis, glutamine shortage induces a rapid YAP dephosphorylation and activation. Upon glutaminolysis inhibition, an increased reactive oxygen species production inhibits LATS kinase via RhoA, leading to YAP dephosphorylation. Activated YAP promotes transcriptional induction of ATF4 to induce the expression of genes involved in amino acid homeostasis, including Sestrin2. We found that YAP-mediated Sestrin2 induction is crucial for cell viability during glutamine deprivation by suppressing mTORC1. Thus, a critical relationship between YAP, ATF4, and mTORC1 is uncovered by our findings. Finally, our data indicate that targeting the Hippo-YAP pathway in combination with glutaminolysis inhibition may provide potential therapeutic approaches to treat tumors.

Abstract P2187: SARS-CoV2 Nonstructural Protein, But Not The Omicron Ba.4/5 Mutant, Suppresses YAP Transcriptional Activity In The Heart

Coronavirus disease 2019 (COVID-19), caused by SARS-CoV2, is a worldwide epidemic resulting in global healthcare crises and strained health resources. Currently, the omicron subvariants of SARS-CoV2, BA.4 and BA.5, have become the predominant variant in circulation around the world. Compared to previous variants, omicron BA.4 and BA.5 escape antibodies created by past COVID-19 vaccines and prior infections due to spike protein mutations. However, why omicron subvariants induce milder symptoms after infection are poorly understood. Here we screened SARS-CoV2 proteins and found that one nonstructural protein suppresses the transcriptional activity of YAP, the Hippo pathway signaling effector, independent of negative regulation by upstream Lats kinases in the heart. Our findings correlate with RNA sequencing data from COVID-19 patient lung samples and iPS cardiomyocytes showing decreased expression levels of YAP target genes, which suggested that SARS-CoV2 infection may affect lung epithelial cell and neonatal cardiomyocyte proliferation. Additionally, we found that the Omicron BA.4/5 variant of this viral protein suppresses YAP activity significantly less compared to the wildtype protein whose mechanism are under exploring now. These findings reveal the previously unknown function and mechanism of SARS-CoV2 nonstructural proteins in host cells. Considering the critical role of Hippo signaling in cell proliferation, apoptosis, and immune response, our data on SARS-CoV2 protein function may partially explain the lesser toxicity of Omicron BA.4/5 to the host cells.

RGS16 regulates Hippo-YAP activity to promote esophageal cancer cell proliferation and migration

Esophageal Squamous Cell Carcinoma (ESCC) is a common malignant tumor of digestive tract, accounting for 90% of all pathological types of esophageal cancer. Despite the rapid development of multi-disciplinary treatment such as surgery, chemotherapy, radiotherapy and chemoradiotherapy, the prognosis of patients with ESCC is still poor. Regulators of G-protein signaling (RGSs) are involved in the processes of various cancers. The expression levels of its family member RGS16 are abnormally elevated in a variety of tumors, but its role in ESCC is still unclear. We found that RGS16 expression is aberrantly increased in ESCC tissues and correlated with poor prognosis of ESCC patients from The Cancer Genome Atlas (TCGA) database and our collected ESCC tissues. Moreover, knockdown of RGS16 in two ESCC cells could indeed inhibit their proliferation and migration. We further explored the molecular mechanism of RGS16 in ESCC, and the correlation analysis from TCGA database showed that the mRNA levels of RGS16 was positively correlated with that of CTGF and CYR61, two target genes of Hippo-YAP signaling. Consistently, RGS16- knockdown significantly inhibited the expression of CTGF and CYR61 in ESCC cells. We found that the phosphorylation levels of LATS1 and YAP were significantly increased and YAP translocated into the cytoplasm after depletion of RGS16 in ESCC cells. Also, RGS16-knockdown promoted the interaction between LATS1 and upstream kinase MST1. In addition, reintroduction of a constitutive active YAP5A mutant significantly rescued CTGF expression and cell proliferation in RGS16-knockdown cells. Together, our work revealed that RGS16 promoted YAP activity through disrupting the interaction between LATS1 and MST1, thus promoting the proliferation and migration of ESCC cells.

Role of mechanotransduction mediated by YAP/TAZ in the treatment of neurogenic erectile dysfunction with low-intensity pulsed ultrasound.

Erectile dysfunction (ED) and weakness of the penis are processes related to hemodynamic alteration. Low-intensity pulsed ultrasound (LIPUS), as a new mechanical modality for the treatment of ED, deserves to be explored in depth for the biomechanical mechanisms it exerts. The aim of this study was to explore the role of YAP/TAZ-mediated mechanotransduction in mechanical therapy for the treatment of neurogenic erectile dysfunction (NED). Forty-two male SD rats (12 w old) were randomly divided into sham-operated (n=14), bilateral cavernous nerve injury (BCNI, n=14), and LIPUS-treated (n=14) groups. Intracavernosal pressure/mean arterial pressure (ICP/MAP) was measured 14 and 28 days after treatment. Penile tissue specimens were collected for pathological examination, and the changes in YAP, TAZ, connective tissue growth factor (CTGF), CYR61, LATS1, and p38 mitogen-activated protein kinase expression levels were assessed by Western blot, real-time quantitative polymerase chain reaction (RT-qPCR) and immunological staining. Compared with BCNI, LIPUS significantly improved ICP/MAP levels and enhanced histopathological changes. The penile expression levels of YAP, TAZ, CTGF, and CYR61 were significantly downregulated in the BCNI group (p<0.01), and LIPUS upregulated the expression levels of these proteins (p<0.05). The expression levels of p-LATS1 and LATS1 were not significantly different among the groups (p>0.05). Interestingly, the expression level of p-p38/p38 significantly increased in BCNI rats (p<0.05), which was reversed by LIPUS treatment (p<0.05). However, the p38 inhibitor SB203580 did not change the expression of YAP/TAZ in rat primary smooth muscle cells or mouse MOVAS cells (p>0.05). LIPUS can effectively improve penile erectile function in NED rats. The underlying mechanism may be related to the regulation of YAP/TAZ-mediated mechanotransduction. However, the upstream regulatory signal may differ from the classical Hippo pathway.

A conserved role of the Hippo signalling pathway in initiation of the first lineage specification event across mammals.

Our understanding of the molecular events driving cell specification in early mammalian development relies mainly on mouse studies, and it remains unclear whether these mechanisms are conserved across mammals, including humans. We have shown that the establishment of cell polarity via aPKC is a conserved event in the initiation of the trophectoderm (TE) placental program in mouse, cow, and human embryos. However, the mechanisms transducing cell polarity into cell fate in cow and human embryos are unknown. Here, we have examined the evolutionary conservation of Hippo signalling, which is thought to function downstream of aPKC activity, in four different mammalian species: mouse, rat, cow, and human. In all four species, inhibition of the Hippo pathway by targeting LATS kinases is sufficient to drive ectopic TE initiation and downregulation of SOX2. However, the timing and localisation of molecular markers differs across species with rat embryos more closely recapitulating human and cow developmental dynamics, compared to the mouse. Our comparative embryology approach uncovered intriguing differences as well as similarities in a fundamental developmental process among mammals, reinforcing the importance of cross-species investigations.

ACADL suppresses PD-L1 expression to prevent cancer immune evasion by targeting Hippo/YAP signaling in lung adenocarcinoma.

Lung cancer is the leading cause of cancer-related death. Cancer immune evasion is a key barrier in the treatment of lung cancer and the development of effective anticancer therapeutics. Long-chain Acyl-CoA dehydrogenase (ACADL), a key enzyme that regulates β-oxidation of long-chain fatty acyl-CoAs, has been found to act as a tumor suppressor in cancers. However, the role of ACADL in lung adenocarcinoma (LUAD) has not been explored. In the current study, we find that ACADL functions as a tumor suppressor in LUAD to inhibit proliferation and enhanced chemotherapeutic drug-induced apoptosis. Interestingly, ACADL prevents tumor immune evasion by suppressing PD-L1 expression in LUAD. ACADL is critical for Hippo/YAP pathway-mediated PD-L1 regulation. Moreover, YAP activation is essential for ACADL suppression of PD-L1 transcription. In addition, ACADL increases the protein stability and kinase activity of LATS kinase to inhibit YAP activation and PD-L1 transcription. Furthermore, we show that ACADL expression is positively correlated with a better OS and FP in LUAD. Our data reveals that ACADL could be a promising target for regulating Hippo/YAP pathway to prevent tumor immune evasion in LUAD.