A New Regulatory Mechanism Between P53 And YAP Crosstalk By SIRT1 Mediated Deacetylation To Regulate Cell Cycle And Apoptosis In A549 Cell Lines

Idebenone Antagonizes P53-Mediated Neuronal Oxidative Stress Injury by Regulating CD38-SIRT3 Protein Level

Idebenone, an antioxidant used in treating oxidative damage-related diseases, has unclear neuroprotective mechanisms. Oxidative stress affects cell and mitochondrial membranes, altering Adp-ribosyl cyclase (CD38) and Silent message regulator 3 (SIRT3) protein expression and possibly impacting SIRT3's ability to deacetylate Tumor protein p53 (P53). This study explores the relationship between CD38, SIRT3, and P53 in H2O2-injured HT22 cells treated with Idebenone. Apoptosis was detected using flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining after determining appropriate H2O2 and Idebenone concentrations.In this study, Idebenone was found to reduce apoptosis and decrease P53 and Caspase3 expression in H2O2-injured HT22 cells by detecting apoptosis-related protein expression. Through bioinformatics methods, CD38 was identified as the target of Idebenone, and it further demonstrated that Idebenone decreased the expression of CD38 and increased the level of SIRT3. An increased NAD+/NADH ratio was detected, suggesting Idebenone induces SIRT3 expression and protects HT22 cells by decreasing apoptosis-related proteins. Knocking down SIRT3 downregulated acetylated P53 (P53Ac), indicating SIRT3's importance in P53 deacetylation.These results supported that CD38 was used as a target of Idebenone to up-regulate SIRT3 to deacetylate activated P53, thereby protecting HT22 cells from oxidative stress injury. Thus, Idebenone is a drug that may show great potential in protecting against reactive oxygen species (ROS) induced diseases such as Parkinson's disease, and Alzheimer's disease. And it might be able to compensate for some of the defects associated with CD38-related diseases.

BDE-209-induced genotoxicity, intestinal damage and intestinal microbiota dysbiosis in zebrafish (Danio Rerio)

The environmental presence of polybrominated diphenyl ethers (PBDEs) is ubiquitous due to their wide use as brominated flame retardants in industrial products. As a common congener of PBDEs, decabromodiphenyl ether (BDE-209) can pose a health risk to animals as well as humans. However, to date, few studies have explored BDE-209's toxic effects on the intestinal tract, and its relevant mechanism of toxicity has not been elucidated. In this study, adult male zebrafish were exposed to BDE-209 at 6 μg/L, 60 μg/L and 600 μg/L for 28 days, and intestinal tissue and microbial samples were collected for analysis to reveal the underlying toxic mechanisms. Transcriptome sequencing results demonstrated a dose-dependent pattern of substantial gene differential expression in the group exposed to BDE-209, and the differentially expressed genes were mainly concentrated in pathways related to protein synthesis and processing, redox reaction, and steroid and lipid metabolism. In addition, BDE-209 exposure caused damage to intestinal structure and barrier function, and promoted intestinal oxidative stress, inflammatory response, apoptosis and steroid and lipid metabolism disorders. Mechanistically, BDE-209 induced intestinal inflammation by increasing the levels of TNF-α and IL-1β and activating the NFκB signaling pathway, and might induce apoptosis through the p53-Bax/Bcl2-Caspase3 pathway. BDE-209 also significantly inhibited the gene expression of rate-limiting enzymes such as Sqle and 3βhsd (p < 0.05) to inhibit cholesterol synthesis. In addition, BDE-209 induced lipid metabolism disorders through the mTOR/PPARγ/RXRα pathway. 16S rRNA sequencing results showed that BDE-209 stress reduced the richness and diversity of intestinal microbiota, and reduced the abundance of probiotics (e.g., Bifidobacterium and Faecalibacterium). Overall, the results of this study help to clarify the intestinal response mechanism of BDE-209 exposure, and provide a basis for evaluating the health risks of BDE-209 in animals.

YAP/TAZ: Molecular pathway and disease therapy

The Yes-associated protein and its transcriptional coactivator with PDZ-binding motif (YAP/TAZ) are two homologous transcriptional coactivators that lie at the center of a key regulatory network of Hippo, Wnt, GPCR, estrogen, mechanical, and metabolism signaling. YAP/TAZ influences the expressions of downstream genes and proteins as well as enzyme activity in metabolic cycles, cell proliferation, inflammatory factor expression, and the transdifferentiation of fibroblasts into myofibroblasts. YAP/TAZ can also be regulated through epigenetic regulation and posttranslational modifications. Consequently, the regulatory function of these mechanisms implicates YAP/TAZ in the pathogenesis of metabolism-related diseases, atherosclerosis, fibrosis, and the delicate equilibrium between cancer progression and organ regeneration. As such, there arises a pressing need for thorough investigation of YAP/TAZ in clinical settings. In this paper, we aim to elucidate the signaling pathways that regulate YAP/TAZ and explore the mechanisms of YAP/TAZ-induce diseases and their potential therapeutic interventions. Furthermore, we summarize the current clinical studies investigating treatments targeting YAP/TAZ. We also address the limitations of existing research on YAP/TAZ and propose future directions for research. In conclusion, this review aims to provide fresh insights into the signaling mediated by YAP/TAZ and identify potential therapeutic targets to present innovative solutions to overcome the challenges associated with YAP/TAZ.

Multi-OMICs landscape of SARS-CoV-2-induced host responses in human lung epithelial cells

COVID-19 pandemic continues to remain a global health concern owing to the emergence of newer variants. Several multi-Omics studies have produced extensive evidence on host-pathogen interactions and potential therapeutic targets. Nonetheless, an increased understanding of host signaling networks regulated by post-translational modifications and their ensuing effect on the cellular dynamics is critical to expanding the current knowledge on SARS-CoV-2 infections. Through an unbiased transcriptomics, proteomics, acetylomics, phosphoproteomics, and exometabolome analysis of a lung-derived human cell line, we show that SARS-CoV-2 Norway/Trondheim-S15 strain induces time-dependent alterations in the induction of type I IFN response, activation of DNA damage response, dysregulated Hippo signaling, among others. We identified interplay of phosphorylation and acetylation dynamics on host proteins and its effect on the altered release of metabolites, especially organic acids and ketone bodies. Together, our findings serve as a resource of potential targets that can aid in designing novel host-directed therapeutic strategies.

Deacetylation of YAP1 Promotes the Resistance to Chemo- and Targeted Therapy in FLT3-ITD+ AML Cells

The FLT3-ITD mutation occurs in about 30% of acute myeloid leukemia (AML) and is associated with poor prognosis. However, FLT3 inhibitors are only partially effective and prone to acquired resistance. Here, we identified Yes-associated protein 1 (YAP1) as a tumor suppressor in FLT3-ITD⁺ AML. YAP1 inactivation conferred FLT3-ITD⁺ AML cell resistance to chemo- and targeted therapy. Mass spectrometric assay revealed that DNA damage repair gene poly (ADP-ribose) polymerase 1 (PARP1) might be the downstream of YAP1, and the pro-proliferative effect by YAP1 knockdown was partly reversed via PARP1 inhibitor. Importantly, histone deacetylase 10 (HDAC10) contributed to decreased YAP1 acetylation levels through histone H3 lysine 27 (H3K27) acetylation, leading to the reduced nuclear accumulation of YAP1. Selective HDAC10 inhibitor chidamide or HDAC10 knockdown activated YAP1, enhanced DNA damage, and significantly attenuated FLT3-ITD⁺ AML cell resistance. In addition, combination chidamide with FLT3 inhibitors or chemotherapy agents synergistically inhibited growth and increased apoptosis of FLT3-ITD⁺ AML cell lines and acquired resistant cells from the relapse FLT3-ITD⁺ AML patients. These findings demonstrate that the HDAC10-YAP1-PARP1 axis maintains FLT3-ITD⁺ AML cells and targeting this axis might improve clinical outcomes in FLT3-ITD⁺ AML patients.

The Hippo Signaling Pathway in Cancer: A Cell Cycle Perspective

Simple Summary

Cancer is increasingly viewed as a cell cycle disease in that the dysregulation of the cell cycle machinery is a common feature in cancer. The Hippo signaling pathway consists of a core kinase cascade as well as extended regulators, which together control organ size and tissue homeostasis. The aberrant expression of cell cycle regulators and/or Hippo pathway components contributes to cancer development, and for this reason, we specifically focus on delineating the roles of the Hippo pathway in the cell cycle. Improving our understanding of the Hippo pathway from a cell cycle perspective could be used as a powerful weapon in the cancer battlefield.

Abstract

Cell cycle progression is an elaborate process that requires stringent control for normal cellular function. Defects in cell cycle control, however, contribute to genomic instability and have become a characteristic phenomenon in cancers. Over the years, advancement in the understanding of disrupted cell cycle regulation in tumors has led to the development of powerful anti-cancer drugs. Therefore, an in-depth exploration of cell cycle dysregulation in cancers could provide therapeutic avenues for cancer treatment. The Hippo pathway is an evolutionarily conserved regulator network that controls organ size, and its dysregulation is implicated in various types of cancers. Although the role of the Hippo pathway in oncogenesis has been widely investigated, its role in cell cycle regulation has not been comprehensively scrutinized. Here, we specifically focus on delineating the involvement of the Hippo pathway in cell cycle regulation. To that end, we first compare the structural as well as functional conservation of the core Hippo pathway in yeasts, flies, and mammals. Then, we detail the multi-faceted aspects in which the core components of the mammalian Hippo pathway and their regulators affect the cell cycle, particularly with regard to the regulation of E2F activity, the G1 tetraploidy checkpoint, DNA synthesis, DNA damage checkpoint, centrosome dynamics, and mitosis. Finally, we briefly discuss how a collective understanding of cell cycle regulation and the Hippo pathway could be weaponized in combating cancer.

Control of tissue homeostasis, tumorigenesis, and degeneration by coupled bidirectional bistable switches

The Hippo-YAP/TAZ signaling pathway plays a critical role in tissue homeostasis, tumorigenesis, and degeneration disorders. The regulation of YAP/TAZ levels is controlled by a complex regulatory network, where several feedback loops have been identified. However, it remains elusive how these feedback loops contain the YAP/TAZ levels and maintain the system in a healthy physiological state or trap the system in pathological conditions. Here, a mathematical model was developed to represent the YAP/TAZ regulatory network. Through theoretical analyses, three distinct states that designate the one physiological and two pathological outcomes were found. The transition from the physiological state to the two pathological states is mechanistically controlled by coupled bidirectional bistable switches, which are robust to parametric variation and stochastic fluctuations at the molecular level. This work provides a mechanistic understanding of the regulation and dysregulation of YAP/TAZ levels in tissue state transitions.

Tissue development and homeostasis require well-controlled cell proliferation. Lack of this control could lead to degenerative or tumorigenic diseases. Signaling pathways have been explored in promoting or inhibiting these diseases. The Hippo signaling pathway is one of these, which has been found to control tissue homeostasis and organ size through cell proliferation and apoptosis, as evidenced by extensive experimental data. However, the question remains of how tissue can transition from a homeostatic state to either a degenerative or tumorigenic state. By theoretically analyzing a mathematical model of its regulatory network, we present a mechanism that underlies Hippo signaling to control tissue transition from a homeostatic state to a disease state. This provides us with a mechanistic understanding of how the parts of the regulatory network are coordinated for the transitions between the homeostasis state and the disease states. In addition, we looked at the role of system noise and found that it could promote the transition to one of the disease states. Our model allows for experimental hypotheses to be generated and could lead to the development of therapeutic strategies by targeting the Hippo signaling pathway.

The Hippo pathway: a renewed insight in the craniofacial diseases and hard tissue remodeling

The Hippo pathway plays an important role in many pathophysiological processes, including cell proliferation and differentiation, cell death, cell migration and invasion. Because of its extensive functions, Hippo pathway is closely related to not only growth and development, but also many diseases, including inflammation and cancer. In this study, the role of Hippo pathway in craniofacial diseases and hard tissue remodeling was reviewed, in attempting to find new research directions.

MicroRNA-146b-5p suppresses cholangiocarcinoma cells by targeting TRAF6 and modulating p53 translocation

BACKGROUND

In view of the poor prognosis and high mortality of cholangiocarcinoma, there is a need for new therapeutic strategies. This study aims to reveal the biological function of miR-146b-5p in cholangiocarcinoma cell and its possible mechanism.

METHODS

The expression level and prognostic information on miR-146b-5p in cholangiocarcinoma were obtained in TCGA database. The biological function of miR-146b-5p on proliferation and vitality of cholangiocarcinoma cell HUCCT-1 was examined by EdU and MTT assay, and the apoptosis of HUCCT-1 cells transfected with miR-146b-5p mimic, mimic control, inhibitor, inhibitor control was detected by flow cytometry analysis. The western blot was done to evaluate the effect of miR-146b-5p targeting substrate and the expression of p53 in whole-cell protein and mitochondria fractions.

RESULTS

Our finding revealed that miR-146b-5p expression in patients with CHOL was lower than the normal group(p＜0.001). MiR-146b-5p expression was down-regulated in human cholangiocarcinoma HUCCT-1 and RBE cells compared to normal control HIBEC and other cancer cells. The miR-146b-5p mimic could inhibit HUCCT-1 cell proliferation (p＜0.05) and promote HUCCT-1 cell apoptosis significantly (p＜0.05). The results of western blot showed that miR-146b-5p mimic could directly target TRAF6 3'UTR region and up-regulate the expression of p53 in mitochondria and miR-146b-5p inhibitor could down-regulated the level of p53 in mitochondria.

CONCLUSION

MiR-146b-5p is a cholangiocarcinoma suppressor by inhibiting cell proliferation and promoting cell apoptosis with targeting TRAF6, possibly via modulating p53 translocation to mitochondria.

Low dose of zearalenone elevated colon cancer cell growth through G protein-coupled estrogenic receptor

Colon cancer is one of the leading causes of cancer death worldwide. It is widely believed that environmental factors contribute to colon cancer development. Zearalenone (ZEA) is non-steroidal estrogenic mycotoxin that is widely found in the human diet and animal feeds. Most cancer studies of ZEA focused on estrogen sensitive cancers, while few focused on other types, such as colon cancer; despite the gastrointestinal tract being the first barrier exposed to food contaminants. This study investigated the stimulatory effects of ZEA on colon cancer cell lines and their underlying molecular mechanisms. ZEA promoted anchorage independent cell growth and cell cycle progression through promoting G1-to-S phase transition. Proliferative marker, cyclin D1 and Ki67 were found to be upregulated upon ZEA treatment. G protein-coupled estrogenic receptor 1 (GPER) protein expression was promoted upon ZEA treatment suggesting the involvement of GPER. The growth promoting effect mediated through GPER were suppressed by its antagonist G15. ZEA were found to promote the downstream parallel pathway, MAPK signaling pathway and Hippo pathway effector YAP1. Altogether, our observations suggest a novel mechanism by which ZEA could promote cancer growth and provide a new perspective on the carcinogenicity of ZEA.

Overexpression of histone deacetylase SIRT1 exerts an antiangiogenic role in diabetic retinopathy via miR-20a elevation and YAP/HIF1α/VEGFA depletion

As a basic member of the Class III histone deacetylases, SIRT1 has been implicated in the occurrence and progression of diabetic retinopathy (DR). The current study aimed to investigate the roles of SIRT1/miR-20a/Yse-associated protein (YAP)/hypoxia-inducible factor 1 α (HIF1α)/vascular endothelial growth factor A (VEGFA) in DR. The expression of SIRT1 was initially determined through quantitative RT-PCR and Western blot analysis following the successful establishment of a DR mouse model, followed by detection of SIRT1 catalytic activity. Retinal microvascular endothelial cells (RMECs) were cultured in media supplemented with normal glucose (NG) or high glucose (HG). Thereafter, SIRT1 was either silenced or overexpressed in RMECs, after which EdU staining and Matrigel-based tube formation assay were performed to assess cell proliferation and tube formation. The binding relationship between YAP, HIF1α, and VEGFA was further illustrated using dual-luciferase reporter assay. Preretinal neovascular cell number was tallied with the IB4-positive vascular endothelial cells, as determined by immunofluorescence. SIRT1 was poorly expressed in mice with DR and HG-treated RMECs with low catalytic activity. The proliferation and tube formation capabilities of RMECs were elevated under HG conditions, which could be reversed following overexpression of SIRT1. SIRT1 was identified as positively regulating the expression of miR-20a with YAP detected as the key target gene of miR-20a. Our data suggested that YAP could upregulate VEGFA via induction of HIF1α. Moreover, SIRT1 overexpression strongly repressed RMEC proliferation and angiogenesis, which could be reversed via restoration of YAP/HIF1α/VEGFA expression. Taken together, the key findings of our study suggest that upregulation of SIRT1 inhibits the development of DR via miR-20a-induced downregulation of YAP/HIF1α/VEGFA.

IRF9 promotes apoptosis and innate immunity by inhibiting SIRT1-p53 axis in fish

As a NAD⁺-dependent deacetylase, SIRT1 is widely involved in apoptosis and cellular inflammation via multiple pathways such as p53, NF-кB and STAT. More and more studies have shown that p53 is the first non-histone deacetylation target of SIRT1. SIRT1-p53 axis thus plays an important role in mammalian cells. IRF9 is an important member of interferon regulator factor family and performs an important role in innate immunity against foreign virus invasion. More importantly, human IRF9 can suppress the SIRT1-p53 axis. However, the functions and relationship between IRF9 and SIRT1-p53 axis are rarely studied in fish. To this end, we made a preliminary research on the functions of grass carp (Ctenopharyngodon idella) IRF9, SIRT1 and p53 in apoptosis and innate immunity. Firstly, we cloned and identified the ORF of SIRT1 (named CiSIRT1, MN125614) from C. idella and demonstrated that CiIRF9 promoted apoptosis, while CiSIRT1 inhibited apoptosis by flow cytometry and TUNEL experiments. Next, we found the interaction between CiSIRT1 and Cip53 in vivo by co-immunoprecipitation experiments. Moreover, the colocalization analysis also showed CiSIRT1 and Cip53 were mainly distributed in nucleus. Thirdly, we got a conclusion that CiIRF9 can repress the expression of CiSIRT1, implying that CiIRF9 regulates CiSIRT1-p53 axis. Finally, CiSIRT1 mRNA level was significantly up-regulated and the expression reached the highest level at 24 h post poly (I:C) stimulation in CIK cells. So, CiSIRT1 may exert an important function in innate immunity. Furthermore, we found CiSIRT1 down-regulated the expression of CiIFN1. In summary, CiIRF9 promotes apoptosis and innate immunity by inhibiting SIRT1-p53 axis. These findings will provide a new theoretical basis for the research on teleost innate immunity.

DNA damage response signaling pathways and targets for radiotherapy sensitization in cancer

Radiotherapy is one of the most common countermeasures for treating a wide range of tumors. However, the radioresistance of cancer cells is still a major limitation for radiotherapy applications. Efforts are continuously ongoing to explore sensitizing targets and develop radiosensitizers for improving the outcomes of radiotherapy. DNA double-strand breaks are the most lethal lesions induced by ionizing radiation and can trigger a series of cellular DNA damage responses (DDRs), including those helping cells recover from radiation injuries, such as the activation of DNA damage sensing and early transduction pathways, cell cycle arrest, and DNA repair. Obviously, these protective DDRs confer tumor radioresistance. Targeting DDR signaling pathways has become an attractive strategy for overcoming tumor radioresistance, and some important advances and breakthroughs have already been achieved in recent years. On the basis of comprehensively reviewing the DDR signal pathways, we provide an update on the novel and promising druggable targets emerging from DDR pathways that can be exploited for radiosensitization. We further discuss recent advances identified from preclinical studies, current clinical trials, and clinical application of chemical inhibitors targeting key DDR proteins, including DNA-PKcs (DNA-dependent protein kinase, catalytic subunit), ATM/ATR (ataxia–telangiectasia mutated and Rad3-related), the MRN (MRE11-RAD50-NBS1) complex, the PARP (poly[ADP-ribose] polymerase) family, MDC1, Wee1, LIG4 (ligase IV), CDK1, BRCA1 (BRCA1 C terminal), CHK1, and HIF-1 (hypoxia-inducible factor-1). Challenges for ionizing radiation-induced signal transduction and targeted therapy are also discussed based on recent achievements in the biological field of radiotherapy.

Effects of acute ammonia toxicity on oxidative stress, DNA damage and apoptosis in digestive gland and gill of Asian clam (Corbicula fluminea)

Ammonia is one of the major pollutants associated with the main river basins due to ammonification of uneaten food and animal excretion, which usually brings detrimental health effects to aquatic invertebrate. However, the mechanisms of ammonia toxicity in aquatic invertebrate have rarely been reported. In this study, C. fluminea was exposed to different levels of ammonia (control group, 10 mg/L, and 25 mg/L) for 24 h and 48 h, and digestive gland and gill were collected to explore toxic effects on oxidative stress, DNA damage and apoptosis under ammonia stress. The results showed that ammonia poisoning could increase the activity of oxidative stress enzyme (SOD and CAT), inducing differentially expressed genes (DRAM2, GADD45, P53, BAX, BCL2, CASP8, CASP9, CASP3, HSP70 and HSP90) and different cytokines (IL-1 beta, IL-8, IL-17 and TNF-alpha) of DNA damage and apoptosis. The difference of toxic effects induced by ammonia among digestive gland and gill were also observed by real-time PCR and TUNEL staining. Our results will be helpful to understand the mechanism of aquatic toxicology induced by ammonia in C. fluminea.