Hippo pathway regulation by phosphatidylinositol transfer protein and phosphoinositides

NDR2 kinase: A review of its physiological role and involvement in carcinogenesis

The Hippo kinase, NDR2, plays a key role in the natural history of several human cancers, particularly lung cancer, by regulating processes such as proliferation, apoptosis, migration, invasion, vesicular trafficking, autophagy, ciliogenesis and immune response. To examine the specificity of NDR2's action, interaction and function in physiological or tumoral contexts, we first focus on the structural differences in the amino-acid sequence between NDR1 and NDR2. We then establish a correlation between these NDR1/2 differences and specific post-translational regulation, as well as the distinct action, interactions, and functions of NDR2 in physiological or tumoral paradigms, such as lung cancer. Furthermore, the full set of NDR2 partners and/or substrates remains to be identified. Given that it is hypothesized that NDR2 and its partners may offer new perspectives for anticancer therapies, we emphasize potential clustering or functional enrichment networks among the NDR2-specific interactants. Additionally, we provide an unpublished proteomic comparison of the NDR1 versus NDR2 interactome, focusing on human bronchial epithelial cells (HBEC-3), lung adenocarcinoma cells (H2030), and their brain metastasis-derived counterparts (H2030-BrM3). In conclusion, this study underscores the pivotal role of NDR2 in cancer progression, particularly lung cancer, and helps to better understand their specific functions and interactions in both normal and tumor contexts. The identification of NDR2 partners and substrates remains essential, with the potential to open new avenues for anticancer therapies.

A brief history of phosphatidylinositol transfer proteins: from the backwaters of cell biology to prime time in lipid signaling

How lipids are sorted between intracellular compartments and what mechanisms support inter-organellar lipid transport define questions that have enjoyed long-standing interest in the cell biology community. Despite tantalizing evidence to the effect that lipids can move between organelles independently of standard modes of vesicular membrane trafficking through the secretory pathway, biochemical dissection of these non-vesicular pathways was initially fraught with experimental challenges. Many of the obstacles have now been overcome and, following initial breakthroughs, the last two decades have witnessed a renaissance in the field of lipid trafficking. Indeed, lipid trafficking and mobilization are now significant components of any discussion regarding secretory vesicle trafficking, organelle biogenesis, agonist-stimulated lipid signaling, and inter-compartmental communication pathways that involve every organelle in the eukaryotic cell. In accord with the theme of this special issue, we focus on the topic of soluble lipid transfer proteins that interface with the metabolism of phosphatidylinositol (PtdIns) and its phosphorylated derivatives - the phosphoinositides. Although phosphoinositides are quantitatively minor lipids in cells, these molecules represent the chemical codes for a major pathway of intracellular signaling in all eukaryotic cells. It is now clear that soluble PtdIns transfer proteins (PITPs) are physiologically critical regulators of specific pathways of phosphoinositide - particularly PtdIns-4-phosphate - signaling. The 'where' PITPs determine the biological outcomes of phosphoinositide signaling, and the 'how' by which PITPs do so, represent increasingly active areas of research in contemporary cell biology. It is these issues we explore from a historical perspective with a focus on the Sec14-like PITPs.

Identification of candidate blood biomarkers through metabolomics analysis in bovine superovulation

Superovulation and embryo transfer technologies provide strong support for improving the productivity of cattle population. A non-invasive diagnostic method for superovulation prediction is necessary to improve its efficiency. Compared to macromolecular substances, there has been an increasing number of studies on small molecular metabolites as biomarkers. This study aimed to identify key biomarkers associated with superovulation outcomes in cows through serum metabolomics analysis. In this study, 36 induced estrus cows were selected, and the blood samples were collected at three time points: before FSH injection, before artificial insemination, and before embryo collection. Then, the cows were classified into high embryonic yield (HEY) and low embryonic yield (LEY) groups based on the total number of embryos. Furthermore, a serum untargeted metabolomics analysis of the two groups was conducted using liquid chromatography with tandem mass spectrometry (LC-MS/MS). A total of 372 embryos were collected. The metabolomics analysis revealed that 1,158 metabolites were detected, and 617 were annotated. In the before FSH injection samples, 121 differential metabolites were identified between the two groups. In the before artificial insemination samples, 129 differential metabolites were identified. In the before embryo collection samples, 201 differential metabolites were identified. A total of 11 differential metabolites were shared between the before FSH injection and before artificial insemination samples, while five differential metabolites were shared across all three samples. The majority of the differential metabolites were significantly enriched in pathways related to amino acid and fatty acid metabolism, digestive system secretion, and ovarian steroidogenesis. This study showed that phosphatidylcholine [PC; 14:0/22:1(13Z)], phosphatidylethanolamine [PE; DiMe (11, 3)], triacylglycerol [TG; 15:0/16:0/22:4 (7Z, 10Z, 13Z, 16Z)], phosphatidylinositol [PI; 16:0/22:2 (13Z, 16Z)], and phosphatidylserine [PS; 18:0/20:4(8Z, 11Z, 14Z, 17Z)] were differentially expressed in the serum during the superovulation period. These could serve as potential biomarkers for embryonic yield prediction in bovine superovulation. The lipid and amino acid metabolic pathways may have an impact on the ovarian response. The results of this study could provide novel screening indexes of donors for bovine superovulation, although the accuracy of the relevant factors requires further investigation.

Phosphatidylinositol 4-phosphate; A minor lipid with multiple personalities

Phosphorylated products of phosphatidylinositol (PI), named Diphosphoinositide (DPI) and triphosphoinositide (TPI) were identified long time ago and found to exhibit high turnover rates based on their rapid 32P-phosphate labeling. The PI kinase activities that were responsible for their production were subsequently identified and found to be associated with different organelle membranes, including the plasma membrane. These activities were then linked with a certain group of cell surface receptors that activated phospholipase C enzymes to hydrolyze PI and used calcium or cGMP as a second messenger. This visionary concept was introduced in the seminal BBA review written by Robert Michell, exactly 50 years ago. The enzymology and functional diversity of PI 4-phosphate (PI4P) (the term that has replaced DPI) has since underwent an expansion that could not have been foreseen. In this review I will attempt to revisit this expansion with some historical reflections celebrating the 50th anniversary of the Michell review.

CD44 on cancer stem cell is a potential immunological and prognostic pan-cancer biomarker

BACKGROUND

CD44, a widely recognized cancer stem cell marker, displayed a vital participation in the cancer immune invasion and may related with the response to the immunotherapy. However, the role of CD44 in cancer immunology is not well defined. Therefore, we intended to explore its prognostic value and potential immunological functions across 33 human cancer types.

METHODS

Based on the data of patients from The Cancer Genome Atlas (TCGA), Sangerbox was used to analyze the correlations between CD44 expression and tumor-infiltrated immune cells, immune checkpoints, neoantigens, microsatellite instability (MSI), and tumor mutational burden (TMB) in human cancers. A mouse model xenografted with shRNA-CD44 MC38 was established.

RESULTS

The elevated CD44 was associated with tumor stage and prognosis in several different cancers. GSEA results showed that upregulated CD44 involved in cancer stem cell associated process, antigen processing and presentation, and immune cells proliferation and activation. CD44 plays an essential role in the tumor immune regulation and immune checkpoints inhibitor response. The correlation of CD44 gene expression and infiltration levels of immune cells varied across different cancer types. Notably, the upregulation of CD44 expression is positively correlated with regulatory CD4 T cells, macrophages M1 and M2 in several analyzed cancers. Furthermore, we verified the effect of CD44 on tumor growth and immune microenvironment in mouse xenografted with shRNA-CD44 MC38. Moreover, DNA methylation existed in CD44 expression and associated with dysfunctional T-cell phenotypes via different mechanisms, thus resulting in tissue-dependent prognoses.

CONCLUSION

CD44 is both a cancer stem cell marker and a potential prognostic and immunological biomarker in various malignant tumors. Moreover, CD44 could be a novel target for immune-based therapy.

A Potential Role of EFR3A in Human Disease States

EFR3A is a conserved peripheral membrane protein required for the plasma membrane localization of the phosphatidylinositol-4 kinase (PI4KIIIα/PI4KA) complex and for regulating the responsiveness of G-protein-coupled receptors. Additionally, it was implicated in several other potentially unrelated physiological functions. In metazoan organisms, EFR3A is ubiquitously co-expressed with its paralog EFR3B which shares similar biological roles. This brief review summarizes the current knowledge regarding the potential roles of EFR3A in human disease states, including neurological and cardiovascular disorders, as well as various neoplasia-based diseases.

Lipid Transfer Proteins and PI4KIIα Initiate Nuclear p53-Phosphoinositide Signaling

Phosphoinositide (PIP n ) messengers are present in non-membranous regions of nuclei where they are assembled into a phosphatidylinositol (PI) 3-kinase (PI3K)/Akt pathway that is distinct from the cytosolic membrane-localized pathway. In the nuclear pathway, PI kinases/phosphatases bind the p53 tumor suppressor protein (wild-type and mutant) to generate p53-PIP n complexes (p53-PIP n signalosome) that activate Akt by a PI3,4,5P 3 -dependent mechanism in non-membranous regions of the nucleus. This pathway is dependent on a source of nuclear PIP n s that is poorly characterized. Here we report that a subset of PI transfer proteins (PITPs), which transport PI between membranes to enable membrane-localized PIP n synthesis, also interact with p53 in the nucleus upon genotoxic stress. Class I PITPs (PITPα/β) specifically supply the PI required for the generation of p53-PIP n complexes and subsequent signaling in the nucleus. Additionally, the PI 4-kinase PI4KIIα binds to p53 and the PITPs to catalyze the formation of p53-PI4P. p53-PI4P is then sequentially phosphorylated to synthesize p53-PIP n complexes that regulate p53 stability, nuclear Akt activation and genotoxic stress resistance. In this way, PITPα/β and PI4KIIα bind p53 and collaborate to initiate p53-PIP n signaling by mechanisms that require PI transfer by PITPα/β and the catalytic activity of PI4KIIα. Moreover, the identification of these critical upstream regulators of p53-PIP n signaling point to PITPα/β and PI4KIIα as novel therapeutic targets in this pathway for diseases like cancer.

Significance statement

PI transfer proteins and a PI 4-kinase initiate nuclear p53-phosphoinositide signaling in membrane-free regions to promote stress resistance.

The Hippo pathway: Organ size control and beyond

The Hippo signaling pathway is a highly conserved signaling network for controlling organ size, tissue homeostasis, and regeneration. It integrates a wide range of intracellular and extracellular signals, such as cellular energy status, cell density, hormonal signals, and mechanical cues, to modulate the activity of YAP/TAZ transcriptional coactivators. A key aspect of Hippo pathway regulation involves its spatial organization at the plasma membrane, where upstream regulators localize to specific membrane subdomains to regulate the assembly and activation of the pathway components. This spatial organization is critical for the precise control of Hippo signaling, as it dictates the dynamic interactions between pathway components and their regulators. Recent studies have also uncovered the role of biomolecular condensation in regulating Hippo signaling, adding complexity to its control mechanisms. Dysregulation of the Hippo pathway is implicated in various pathological conditions, particularly cancer, where alterations in YAP/TAZ activity contribute to tumorigenesis and drug resistance. Therapeutic strategies targeting the Hippo pathway have shown promise in both cancer treatment, by inhibiting YAP/TAZ signaling, and regenerative medicine, by enhancing YAP/TAZ activity to promote tissue repair. The development of small molecule inhibitors targeting the YAP-TEAD interaction and other upstream regulators offers new avenues for therapeutic intervention. SIGNIFICANCE STATEMENT: The Hippo signaling pathway is a key regulator of organ size, tissue homeostasis, and regeneration, with its dysregulation linked to diseases such as cancer. Understanding this pathway opens new possibilities for therapeutic approaches in regenerative medicine and oncology, with the potential to translate basic research into improved clinical outcomes.

Exploring the genetic correlation and causal relationships between breast cancer and meningioma using bidirectional Mendelian randomization

Previous studies have indicated a significantly higher prevalence of breast cancer (BC) among female patients with meningioma compared to the general female population. Therefore, this study aimed to assess the causal relationship between BC and meningioma at the genetic level. Genetic instrumental variables (IVs) for BC were identified from the Breast Cancer Association Consortium (BCAC), the Discovery Biology and Risk of Inherited Variants in Breast Cancer Consortium (DRIVE), the Collaborative Oncological Gene-environment Study (iCOGS), and 11 other BC genome-wide association studies (GWAS). Meningioma GWAS data were obtained from the FinnGen consortium and were further divided into intracranial and spinal meningioma groups for analysis. The primary analysis employed the inverse-variance weighted (IVW) method, supported by sensitivity analysis to address pleiotropy and enhance robustness. Next, linkage disequilibrium score regression (LDSC) was used to assess the genetic correlation between BC and meningioma. Finally, we applied the Functional Mapping and Annotation (FUMA) platform to conduct an in-depth analysis of the GWAS data. After rigorous screening and Mendelian randomization (MR) tests, genetically predicted overall BC (OR: 1.17, P = 0.0045) and ER(estrogen receptors) + BC (OR: 1.21, P = 0.0006) showed a potential causal association with intracranial meningioma. No causal relationships were found between intracranial meningioma and three BC subtypes. No bidirectional causal relationships were found between spinal meningioma and any BC subtype. The LDSC results suggested a modest positive genetic correlation between overall BC (rg: 0.152, SE: 0.077, P = 0.048), ER + BC (rg: 0.181, SE: 0.086, P = 0.035), and intracranial meningioma. FUMA analysis identified PITPNB, TTC28, and CHEK2 as shared risk genes between overall BC, ER + BC, and intracranial meningioma. These findings suggest that BC, especially ER + BC, may be a risk factor for intracranial meningioma. ER-related signaling pathways and the regulation of DNA damage may play a critical role in the pathogenesis of both diseases.

Cancer-associated fibroblasts induce almonertinib resistance in non-small cell lung cancer

BACKGROUND

Almonertinib is the initial third-generation EGFR-TKI in China, but its resistance mechanism is unknown. Cancer-associated fibroblasts (CAFs) are essential matrix components in the tumor microenvironment, but their impact on almonertinib resistance is unknown. This study aimed to explore the correlation between CAFs and almonertinib resistance in non-small cell lung cancer (NSCLC).

METHODS

The anti-cancer effects of almonertinib on NSCLC cells, as well as the reversal of these effects mediated by CAFs, were validated through phenotypic experiments. Differential gene expression analysis, along with GO and KEGG enrichment analyses, was performed to predict the potential mechanisms underlying resistance to third-generation EGFR-TKIs. Finally, qPCR and Western blot analyses were used to explore the signaling pathways by which CAFs induce resistance to almonertinib in NSCLC cells.

RESULTS

Our findings revealed that almonertinib significantly suppressed the invasion, migration, and proliferation of EGFR T790M-mutant NSCLC cells. TGF-β1 successfully induced the differentiation of CAFs and upregulated the expression of CAF markers, including α-SMA and fibroblast activation protein (FAP). Exposure of H1975 cells to almonertinib increased TGF-β1 secretion. Additionally, CAFs enhanced the survival of almonertinib-treated NSCLC cells, whereas normal fibroblasts (NFs) exerted the opposite effect. qPCR analysis demonstrated that the expression of the core molecules of the Hippo pathway, YAP and TAZ, was lower in A549 cells than in H1975 cells, and CAF intervention further reduced YAP/TAZ expression in H1975 cells. Western blot analysis confirmed a significant reduction in YAP/TAZ protein levels in cancer cells treated with CAF-conditioned medium (CAF-CM) compared to those treated with normal control-conditioned medium (NC-CM). Finally, we demonstrated that CAFs induced resistance to almonertinib in NSCLC cells, potentially through a mechanism involving YAP/TAZ.

CONCLUSION

This study demonstrated that H1975 cells stimulated by almonertinib promoted the accumulation of CAFs in NSCLC cells, likely through increased secretion of TGF-β1. The accumulation of CAFs enhanced the survival of NSCLC cells undergoing almonertinib treatment and induced drug resistance. Additionally, the mechanism underlying CAF-induced drug resistance in NSCLC cells was potentially linked to the activation of the YAP/TAZ signaling pathway.

Mammalian START-like phosphatidylinositol transfer proteins - Physiological perspectives and roles in cancer biology

PtdIns and its phosphorylated derivatives, the phosphoinositides, are the biochemical components of a major pathway of intracellular signaling in all eukaryotic cells. These lipids are few in terms of cohort of unique positional isomers, and are quantitatively minor species of the bulk cellular lipidome. Nevertheless, phosphoinositides regulate an impressively diverse set of biological processes. It is from that perspective that perturbations in phosphoinositide-dependent signaling pathways are increasingly being recognized as causal foundations of many human diseases - including cancer. Although phosphatidylinositol transfer proteins (PITPs) are not enzymes, these proteins are physiologically significant regulators of phosphoinositide signaling. As such, PITPs are conserved throughout the eukaryotic kingdom. Their biological importance notwithstanding, PITPs remain understudied. Herein, we review current information regarding PITP biology primarily focusing on how derangements in PITP function disrupt key signaling/developmental pathways and are associated with a growing list of pathologies in mammals.

EIF4A3-Induced Upregulation of hsa_circ_0049396 Attenuates the Tumorigenesis of Nasopharyngeal Carcinoma by Regulating the Hippo-YAP Pathway

Circular RNAs (circRNAs) and eukaryotic translation initiation factor 4A3 (EIF4A3) have been reported to participate in the pathogenesis of nasopharyngeal carcinoma (NPC), but their mechanism has not been fully understood. This research aimed to confirm the role and regulatory mechanism of hsa_circ_0049396 interacting with EIF4A3 in NPC tumorigenesis. Quantitative real time polymerase chain reaction (qRT-PCR) was executed to detect the levels of hsa_circ_0049396 and EIF4A3. Cell function experiments and nude mice xenograft assay were used to confirm the role of hsa_circ_0049396 in NPC. The regulatory effect of EIA4A3 on hsa_circ_0049396 was determined by circInteractome prediction, RNA binding protein immunoprecipitation (RIP) assay, and qRT-PCR. In addition, the Hippo-YAP pathway-related proteins and EIF4A3 protein were detected by western blotting. hsa_circ_0049396 was proved to be downregulated in NPC samples, and its low expression indicated the poor prognosis of NPC. After upregulating hsa_circ_0049396 in NPC cells, the proliferation, migration, invasion, and tumor growth in vivo were suppressed by inhibiting the Hippo-YAP pathway. Moreover, EIF4A3 bound to the flanking regions of the hsa_circ_0049396 to enhance hsa_circ_0049396 expression in NPC cells. hsa_circ_0049396 mediated by EIF4A3 in NPC can attenuate NPC tumorigenesis by inhibiting the Hippo-YAP pathway. This finding may provide a potential early diagnostic biomarker or drug target to improve the precision medicine approaches of NPC.

Plastic takeaway food containers may cause human intestinal damage in routine life usage: Microplastics formation and cytotoxic effect

The microplastics and organic additives formed in routine use of plastic takeaway food containers may pose significant health risks. Thus, we collected plastic containers made of polystyrene, polypropylene, polyethylene terephthalate, polylactic acid and simulated two thermal usages, including hot water (I) and microwave treatments (M). Nile Red fluorescence staining was developed to improve accurate counting of microplastics with the aid of TEM and DLS analysis. The quantity of MPs released from thermal treatments was determined ranging from 285.7 thousand items/cm2 to 681.5 thousand items/cm2 in containers loaded with hot water with the following order: IPS>IPP>IPET>IPLA, while microwave treatment showed lower values ranging from 171.9 thousand items/cm2 to 301.6 thousand items/cm2. In vitro toxicity test using human intestinal epithelial Caco-2 cells indicated decrease of cell viability in raw leachate, resuspended MPs and supernatants, which might further lead to cell membrane rupture, ROS production, and decreased mitochondrial membrane potential. Moreover, the leachate inhibited the expression of key genes in the electron transport chain (ETC) process, disrupted energy metabolism. For the first time, we isolate the actually released microplastics and organic substances for in vitro toxicity testing, and demonstrate their potential impacts to human intestine. SYNOPSIS: Plastic take-out containers may release microplastics and organic substances during daily usage, both of which can cause individual and combined cytotoxic effects on human colon adenocarcinoma cells Caco-2.

PI4P-mediated solid-like Merlin condensates orchestrate Hippo pathway regulation

Despite recent studies implicating liquid-like biomolecular condensates in diverse cellular processes, many biomolecular condensates exist in a solid-like state, and their function and regulation are less understood. We show that the tumor suppressor Merlin, an upstream regulator of the Hippo pathway, localizes to both cell junctions and medial apical cortex in Drosophila epithelia, with the latter forming solid-like condensates that activate Hippo signaling. Merlin condensation required phosphatidylinositol-4-phosphate (PI4P)-mediated plasma membrane targeting and was antagonistically controlled by Pez and cytoskeletal tension through plasma membrane PI4P regulation. The solid-like material properties of Merlin condensates are essential for physiological function and protect the condensates against external perturbations. Collectively, these findings uncover an essential role for solid-like condensates in normal physiology and reveal regulatory mechanisms for their formation and disassembly.

Circular RNA circ_ARHGEF28 inhibits MST1/2 dimerization to suppress Hippo pathway to induce cisplatin resistance in ovarian cancer

BACKGROUND

Cisplatin is integral to ovarian cancer treatment, yet resistance to this drug often results in adverse patient outcomes. The association of circular RNA (circRNA) with cisplatin resistance in ovarian cancer has been observed, but the mechanisms governing this relationship require further elucidation.

METHODS

High-throughput sequencing was utilized to profile circRNA expression in cisplatin-resistant ovarian cancer cells. Gain-and-loss-of-function experiments assessed the impact on cisplatin sensitivity, both in vitro and in vivo. Fluorescence in situ hybridization was conducted to determine the cellular distribution of circRNAs, and RNA pulldown and immunoprecipitation experiments were performed to identify associated binding proteins.

RESULTS

The study revealed that circ_ARHGEF28 is overexpressed in certain cisplatin-resistant ovarian cancer tissues and cell lines, and is associated with reduced progression-free survival in patients. It was observed that circ_ARHGEF28 contributes to cisplatin resistance in ovarian cancer models, both in vitro and in vivo. Importantly, circ_ARHGEF28 was found to interact directly with MST1/2, inhibiting the SARAH coiled-coil binding domains and consequently deactivating the Hippo pathway.

CONCLUSION

This investigation identifies circ_ARHGEF28 as a novel circRNA that contributes to cisplatin resistance in ovarian cancer by suppressing the Hippo pathway. Therapeutic strategies targeting circ_ARHGEF28 may offer a potential avenue to mitigate cisplatin resistance in ovarian cancer treatment.

Inhibition of YAP/TAZ pathway contributes to the cytotoxicity of silibinin in MCF-7 and MDA-MB-231 human breast cancer cells

Breast cancer is one of the most common cancers threatening women's health. Our previous study found that silibinin induced the death of MCF-7 and MDA-MB-231 human breast cancer cells. We noticed that silibinin-induced cell damage was accompanied by morphological changes, including the increased cell aspect ratio (cell length/width) and decreased cell area. Besides, the cytoskeleton is also destroyed in cells treated with silibinin. YAP/TAZ, a mechanical signal sensor interacted with extracellular pressure, cell adhesion area and cytoskeleton, is also closely associated with cell survival, proliferation and migration. Thus, the involvement of YAP/TAZ in the cytotoxicity of silibinin in breast cancer cells has attracted our interests. Excitingly, we find that silibinin inhibits the nuclear translocation of YAP/TAZ in MCF-7 and MDA-MB-231 cells, and reduces the mRNA expressions of YAP/TAZ target genes, ACVR1, MnSOD and ANKRD. More importantly, expression of YAP1 gene is negatively correlated with the survival of the patients with breast cancers. Molecular docking analysis reveals high probabilities for binding of silibinin to the proteins in the YAP pathways. DARTS and CETSA results confirm the binding abilities of silibinin to YAP and LATS. Inhibiting YAP pathway either by addition of verteporfin, an inhibitor of YAP/TAZ-TEAD, or by transfection of si-RNAs targeting YAP or TAZ further enhances silibinin-induced cell damage. While enhancing YAP activity by silencing LATS1/2 or overexpressing YAPS127/397A, an active form of YAP, attenuates silibinin-induced cell damage. These findings demonstrate that inhibition of the YAP/TAZ pathway contributes to cytotoxicity of silibinin in breast cancers, shedding lights on YAP/TAZ-targeted cancer therapies.

Research progress on Hippo signaling pathway effector molecules in rheumatic immune system diseases

The core components of the Hippo signaling pathway encompass upstream regulatory molecules, core kinase cascade complexes, and downstream transcriptional regulation complexes. This pathway modulates cellular behaviors by influencing the effector molecules of its core components and plays a pivotal role in immune regulation. Effector molecules,such as Yes-associated protein (YAP), transcriptional coactivator with PDZ-binding motif (TAZ), transcriptional enhanced associate domain transcriptional factor (TEAD), monopolar spindle-one binder (MOB1), large tumor suppressor (LATS), can stimulate fibroblast-like synovial cell migration and invasion in rheumatoid arthritis, regulate osteoarthritis disease progression, promote pathological new bone formation in ankylosing spondylitis, sustain submandibular gland development while delaying Sjogren's syndrome progression, mediate alpha-smooth muscle actin in systemic sclerosis, and refine the regulation of target genes associated with pulmonary fibrosis. This article provides an overview of the regulatory mechanisms involving Hippo signaling pathway-related effector molecules in the pathogenesis and progression of rheumatic immune system diseases, to serve as a reference for exploring novel therapeutic targets of rheumatic immune system diseases.

Neurofibromin 2 modulates Mammalian Ste2-like kinases1/2 and large tumor suppressor gene1 expression in A549 lung cancer cell line

AIM

To explore the impact of up- or down-regulation of Neurofibromin 2 (NF2) on the expression of downstream Hippo pathway genes, large tumor suppressor gene1 (LATS1), and phosphorylation of Mammalian Ste2-like kinases1/2 (MST1/2), in lung cancer cells.

METHODS

A549 lung cancer cells were used. The NF2 was down-regulated by si-RNA interference and upregulated by lentiviral vector mediated overexpression. The LATS1 and MST1/2 expressions were evaluated by real-time PCR and western blot.

RESULTS

Down-regulation of NF2 decreased LATS1 and MST1/2 level (P<0.05). Overexpression of NF2 increased LATS1 (P<0.05) and Mammalian Ste2-like kinases1 (MST1) (P<0.05), suggesting LATS1 and MST1 are modulated by NF2 in a lung cancer cell line.

CONCLUSIONS

NF2 mediates the downstream LATS1 and MST1/2 expressions in a lung cancer cell line.

Hippo and PI5P4K signaling intersect to control the transcriptional activation of YAP

Phosphoinositides are essential signaling molecules. The PI5P4K family of phosphoinositide kinases and their substrates and products, PI5P and PI4,5P2, respectively, are emerging as intracellular metabolic and stress sensors. We performed an unbiased screen to investigate the signals that these kinases relay and the specific upstream regulators controlling this signaling node. We found that the core Hippo pathway kinases MST1/2 phosphorylated PI5P4Ks and inhibited their signaling in vitro and in cells. We further showed that PI5P4K activity regulated several Hippo- and YAP-related phenotypes, specifically decreasing the interaction between the key Hippo proteins MOB1 and LATS and stimulating the YAP-mediated genetic program governing epithelial-to-mesenchymal transition. Mechanistically, we showed that PI5P interacted with MOB1 and enhanced its interaction with LATS, thereby providing a signaling connection between the Hippo pathway and PI5P4Ks. These findings reveal how these two important evolutionarily conserved signaling pathways are integrated to regulate metazoan development and human disease.

Nuclear phosphoinositide signaling promotes YAP/TAZ-TEAD transcriptional activity in breast cancer

The Hippo pathway effectors Yes-associated protein 1 (YAP) and its homolog TAZ are transcriptional coactivators that control gene expression by binding to TEA domain (TEAD) family transcription factors. The YAP/TAZ-TEAD complex is a key regulator of cancer-specific transcriptional programs, which promote tumor progression in diverse types of cancer, including breast cancer. Despite intensive efforts, the YAP/TAZ-TEAD complex in cancer has remained largely undruggable due to an incomplete mechanistic understanding. Here, we report that nuclear phosphoinositides function as cofactors that mediate the binding of YAP/TAZ to TEADs. The enzymatic products of phosphoinositide kinases PIPKIα and IPMK, including phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and phosphatidylinositol 3,4,5-trisphosphate (P(I3,4,5)P3), bridge the binding of YAP/TAZ to TEAD. Inhibiting these kinases or the association of YAP/TAZ with PI(4,5)P2 and PI(3,4,5)P3 attenuates YAP/TAZ interaction with the TEADs, the expression of YAP/TAZ target genes, and breast cancer cell motility. Although we could not conclusively exclude the possibility that other enzymatic products of IPMK such as inositol phosphates play a role in the mechanism, our results point to a previously unrecognized role of nuclear phosphoinositide signaling in control of YAP/TAZ activity and implicate this pathway as a potential therapeutic target in YAP/TAZ-driven breast cancer.

Non-vesicular phosphatidylinositol transfer plays critical roles in defining organelle lipid composition

Phosphatidylinositol (PI) is the precursor lipid for the minor phosphoinositides (PPIns), which are critical for multiple functions in all eukaryotic cells. It is poorly understood how phosphatidylinositol, which is synthesized in the ER, reaches those membranes where PPIns are formed. Here, we used VT01454, a recently identified inhibitor of class I PI transfer proteins (PITPs), to unravel their roles in lipid metabolism, and solved the structure of inhibitor-bound PITPNA to gain insight into the mode of inhibition. We found that class I PITPs not only distribute PI for PPIns production in various organelles such as the plasma membrane (PM) and late endosomes/lysosomes, but that their inhibition also significantly reduced the levels of phosphatidylserine, di- and triacylglycerols, and other lipids, and caused prominent increases in phosphatidic acid. While VT01454 did not inhibit Golgi PI4P formation nor reduce resting PM PI(4,5)P2 levels, the recovery of the PM pool of PI(4,5)P2 after receptor-mediated hydrolysis required both class I and class II PITPs. Overall, these studies show that class I PITPs differentially regulate phosphoinositide pools and affect the overall cellular lipid landscape.

The expanding roles of PI4P and PI(4,5)P2 at the plasma membrane: Role of phosphatidylinositol transfer proteins

Phosphoinositides are phosphorylated derivatives of phosphatidylinositol, a phospholipid that is synthesised at the endoplasmic reticulum. The plasma membrane contains the enzymes to phosphorylate phosphatidylinositol and is therefore rich in the phosphorylated derivatives, PI4P and PI(4,5)P2. PI(4,5)P2 is a substrate for phospholipase C and during cell signaling, PI(4,5)P2 levels are reduced. Here I discuss a family of proteins, phosphatidylinositol transfer proteins (PITPs) that can restore PI(4,5)P2 levels.

Evaluating the Metabolic Basis of α-Gal A mRNA Therapy for Fabry Disease

mRNA injection-based protein supplementation has emerged as a feasible treatment for Fabry disease. However, whether the introduction of LNP-encapsulated mRNA results in the alteration of metabolomics in an in vivo system remains largely unknown. In the present study, α-galactosidase A (α-Gal A) mRNA was generated and injected into the Fabry disease mouse model. The α-Gal A protein was successfully expressed. The level of globotriaosylsphingosine (Lyso-Gb3), a biomarker for Fabry disease, as well as pro-inflammatory cytokines such as nuclear factor kappa-B (NF-κB), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α), were greatly decreased compared to the untreated control, indicating the therapeutic outcome of the mRNA drug. Metabolomics analysis found that the level of 20 metabolites was significantly altered in the plasma of mRNA-injected mice. These compounds are primarily enriched in the arachidonic acid metabolism, alanine, aspartate and glutamate metabolism, and glycolysis/gluconeogenesis pathways. Arachidonic acid and 5-hydroxyeicosatetraenoic acid (5-HETE), both of which are important components in the eicosanoid pathway and related to inflammation response, were significantly increased in the injected mice, possibly due to the presence of lipid nanoparticles. Moreover, mRNA can effectively alter the level of metabolites in the amino acid and energy metabolic pathways that are commonly found to be suppressed in Fabry disease. Taken together, the present study demonstrated that in addition to supplementing the deficient α-Gal A protein, the mRNA-based therapeutic agent can also affect levels of metabolites that may help in the recovery of metabolic homeostasis in the full body system.

Potential Regulatory Gene Network Associated with the Ameliorative Effect of Oat Antibacterial Peptides on Rat Colitis

Oat protein is unstable in intestinal fluid digestion, and it is easily degraded by trypsin and chymotrypsin, producing low molecular weight peptides. Endopeptidase hydrolysis can improve the bioavailability of active peptides and avoid further digestion in the gastrointestinal tract. Antimicrobial peptides (AMPs) can effectively improve host immunity, but most related studies focus on physiology and ecology, and there are few reports on their molecular level. Therefore, in this article, oat peptides were prepared via the simulated digestion method in vitro, and the main metabolites and action factors affecting colitis were screened by using the multi-omics methods in a high-throughput mode to analyze the effect and mechanism of colitis. Firstly, oat antimicrobial peptides were prepared from cationic resin combined with HPLC, and the anti-inflammatory effects of antimicrobial peptides were analyzed in vitro through the use of human colon epithelial (HCoEpiC) anti-inflammatory cells. In vivo experiments using rats have verified that AMPs can effectively prevent colitis caused by dextran sodium sulfate (DSS), reduce intestinal inflammatory cell infiltration and glandular disappearance in the colon, and reduce the apoptosis rate of colon cells. Secondly, metabolomics and transcriptomics were combined to analyze the mechanism of preventing enteritis, and it was found that oat antimicrobial peptides can promote DAG diglycerol production and inhibit the activation of T helper cells (TH), resulting in the down-regulation of key factors in the main downstream pathways of TH1, TH2 and TH17, and inhibit the production of inflammatory cells. At the same time, AMP can activate the wnt pathway, improve the expression of key genes of wnt and frizzled, promote the generation of intestinal stem cells, facilitate the differentiation and repair of intestinal epithelial cells, and prevent the generation of enteritis. Finally, the underlying genetic regulatory network of the important pathway was constructed from the effect of AMP on rat colitis.

Integrated Metabolomics and Transcriptomics Analyses Reveal the Candidate Genes Regulating the Meat Quality Change by Castration in Yudong Black Goats (Capra hircus)

Yudong black goats (YDGs) are a local breed in southwest China that possess unique meat qualities and produce a high meat yield, making them ideal models for studying goat meat quality. Castration may decrease off-odors, significantly change metabolites and improve meat quality. Using multi-omics techniques, this study focused on Yudong black goat wethers (YDW, n = 4) and Yudong black bucks (YDB, n = 4). The findings revealed that 33 differentially expressed genes (DEGs) and 279 significantly changed metabolites (SCMs) influenced goat meat quality by affecting fat accumulation and lipolysis regulatory processes. Herein, several candidate genes (IGF1, TNNT2, PPP2R2C, MAPK10 and VNN1, etc.) were identified that play a role in regulating meat quality, non-castrated and castrated, alongside a series of metabolites that may serve as potential meat quality biomarkers. Lipids (triglycerides, oxidized lipids_5-iso PGF2VI, ceramide (t18:1/36:2(2OH)) and Carnitine C20:5, etc.) were significantly higher in the castrated goats. These results revealed that lipids and hydrophilic metabolites were affected by castration, which might be beneficial in terms of goat meat quality. This study aimed to investigate the differences in meat quality between uncastrated and castrated male goats and the possible molecular regulatory mechanisms.

Microcolin H, a novel autophagy inducer, exerts potent antitumour activity by targeting PITPα/β

The identification of effective drug targets and the development of bioactive molecules are areas of high need in cancer therapy. The phosphatidylinositol transfer protein alpha/beta isoform (PITPα/β) has been reported to play an essential role in integrating phosphoinositide trafficking and lipid metabolism in diverse cellular processes but remains unexplored as a potential target for cancer treatment. Herein, data analysis of clinical cancer samples revealed that PITPα/β expression is closely correlated with the poor prognosis. Target identification by chemical proteomic methods revealed that microcolin H, a naturally occurring marine lipopeptide, directly binds PITPα/β and displays antiproliferative activity on different types of tumour cell lines. Furthermore, we identified that microcolin H treatment increased the conversion of LC3I to LC3II, accompanied by a reduction of the level of p62 in cancer cells, leading to autophagic cell death. Moreover, microcolin H showed preeminent antitumour efficacy in nude mouse subcutaneous tumour models with low toxicity. Our discoveries revealed that by targeting PITPα/β, microcolin H induced autophagic cell death in tumours with efficient anti-proliferating activity, which sheds light on PITPα/β as a promising therapeutic target for cancer treatment.

Natural Products in Renal-Associated Drug Discovery

The global increase in the incidence of kidney failure constitutes a major public health problem. Kidney disease is classified into acute and chronic: acute kidney injury (AKI) is associated with an abrupt decline in kidney function and chronic kidney disease (CKD) with chronic renal failure for more than three months. Although both kidney syndromes are multifactorial, inflammation and oxidative stress play major roles in the diversity of processes leading to these kidney malfunctions. Here, we reviewed various publications on medicinal plants with antioxidant and anti-inflammatory properties with the potential to treat and manage kidney-associated diseases in rodent models. Additionally, we conducted a meta-analysis to identify gene signatures and associated biological processes perturbed in human and mouse cells treated with antioxidants such as epigallocatechin gallate (EGCG), the active ingredient in green tea, and the mushroom Ganoderma lucidum (GL) and in kidney disease rodent models. We identified EGCG- and GL-regulated gene signatures linked to metabolism; inflammation (NRG1, E2F1, NFKB1 and JUN); ion signalling; transport; renal processes (SLC12A1 and LOX) and VEGF, ERBB and BDNF signalling. Medicinal plant extracts are proving to be effective for the prevention, management and treatment of kidney-associated diseases; however, more detailed characterisations of their targets are needed to enable more trust in their application in the management of kidney-associated diseases.

Crystal Structure of the ORP8 Lipid Transport ORD Domain: Model of Lipid Transport

ORPs are lipid-transport proteins belonging to the oxysterol-binding protein family. They facilitate the transfer of lipids between different intracellular membranes, such as the ER and plasma membrane. We have solved the crystal structure of the ORP8 lipid transport domain (ORD8). The ORD8 exhibited a β-barrel fold composed of anti-parallel β-strands, with three α-helices replacing β-strands on one side. This mixed alpha-beta structure was consistent with previously solved structures of ORP2 and ORP3. A large cavity (≈1860 Å3) within the barrel was identified as the lipid-binding site. Although we were not able to obtain a lipid-bound structure, we used computer simulations based on our crystal structure to dock PS and PI4P molecules into the putative lipid-binding site of the ORD8. Comparative experiments between the short ORD8ΔLid (used for crystallography) and the full-length ORD8 (lid containing) revealed the lid's importance for stable lipid binding. Fluorescence assays revealed different transport efficiencies for PS and PI4P, with the lid slowing down transport and stabilizing cargo. Coarse-grained simulations highlighted surface-exposed regions and hydrophobic interactions facilitating lipid bilayer insertion. These findings enhance our comprehension of ORD8, its structure, and lipid transport mechanisms, as well as provide a structural basis for the design of potential inhibitors.

The Hippo signaling pathway in gastric cancer

Gastric cancer (GC) is an aggressive malignant disease which still lacks effective early diagnosis markers and targeted therapies, representing the fourth-leading cause of cancer-associated death worldwide. The Hippo signaling pathway plays crucial roles in organ size control and tissue homeostasis under physiological conditions, yet its aberrations have been closely associated with several hallmarks of cancer. The last decade witnessed a burst of investigations dissecting how Hippo dysregulation contributes to tumorigenesis, highlighting the therapeutic potential of targeting this pathway for tumor intervention. In this review, we systemically document studies on the Hippo pathway in the contexts of gastric tumor initiation, progression, metastasis, acquired drug resistance, and the emerging development of Hippo-targeting strategies. By summarizing major open questions in this field, we aim to inspire further in-depth understanding of Hippo signaling in GC development, as well as the translational implications of targeting Hippo for GC treatment.

Multiscale fluorescence imaging of living samples

Fluorescence microscopy is a highly effective tool for interrogating biological structure and function, particularly when imaging across multiple spatiotemporal scales. Here we survey recent innovations and applications in the relatively understudied area of multiscale fluorescence imaging of living samples. We discuss fundamental challenges in live multiscale imaging and describe successful examples that highlight the power of this approach. We attempt to synthesize general strategies from these test cases, aiming to help accelerate progress in this exciting area.