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PeerJ 2024PLAUR has been found upregulated in various tumors and closely correlated with the malignant phenotype of tumor cells. The aim of this study was to investigate the...
BACKGROUND
PLAUR has been found upregulated in various tumors and closely correlated with the malignant phenotype of tumor cells. The aim of this study was to investigate the relationship between PLAUR and clear cell renal cell carcinoma (ccRCC) and its potential mechanism of promoting tumor progression.
METHODS
The expression levels and clinical significance of PLAUR, along with the associated signaling pathways, were extensively investigated in ccRCC samples obtained from The Cancer Genome Atlas (TCGA). PLAUR expression in 20 pairs of ccRCC tumor tissues and the adjacent tissues was assessed using qRT-PCR and IHC staining. Additionally, a series of experiments were conducted to investigate the impact of PLAUR suppression on cellular proliferation, migration, invasion, cell cycle progression, and apoptosis in ccRCC. The Western blot analysis was employed to investigate the expression levels of pivotal genes associated with the PI3K/AKT/mTOR signaling pathway.
RESULTS
The expression of PLAUR was significantly upregulated in ccRCC compared to normal renal tissues, and higher PLAUR expression in ccRCC was associated with a poorer prognosis than low expression. The functional investigations demonstrated that knockdown of PLAUR significantly attenuated the proliferation, migration, and invasion capabilities of ccRCC cells. Concurrently, PLAUR knockdown effectively induced cellular apoptosis, modulated the cell cycle, inhibited the EMT process, and attenuated the activation of the PI3K/AKT/mTOR signaling pathway. PLAUR may represent a key mechanism underlying ccRCC progression.
CONCLUSIONS
The involvement of PLAUR in ccRCC progression may be achieved through the activation of the PI3K/AKT/mTOR signaling pathway, making it a reliable biomarker for the identification and prediction of ccRCC.
Topics: Humans; Carcinoma, Renal Cell; TOR Serine-Threonine Kinases; Kidney Neoplasms; Signal Transduction; Proto-Oncogene Proteins c-akt; Phosphatidylinositol 3-Kinases; Disease Progression; Cell Proliferation; Cell Line, Tumor; Male; Female; Apoptosis; Cell Movement; Middle Aged; Gene Expression Regulation, Neoplastic; Prognosis; Up-Regulation
PubMed: 38948215
DOI: 10.7717/peerj.17555 -
Theranostics 2024PRL1 and PRL3, members of the protein tyrosine phosphatase family, have been associated with cancer metastasis and poor prognosis. Despite extensive research on their...
PRL1 and PRL3, members of the protein tyrosine phosphatase family, have been associated with cancer metastasis and poor prognosis. Despite extensive research on their protein phosphatase activity, their potential role as lipid phosphatases remains elusive. We conducted comprehensive investigations to elucidate the lipid phosphatase activity of PRL1 and PRL3 using a combination of cellular assays, biochemical analyses, and protein interactome profiling. Functional studies were performed to delineate the impact of PRL1/3 on macropinocytosis and its implications in cancer biology. Our study has identified PRL1 and PRL3 as lipid phosphatases that interact with phosphoinositide (PIP) lipids, converting PI(3,4)P and PI(3,5)P into PI(3)P on the cellular membranes. These enzymatic activities of PRLs promote the formation of membrane ruffles, membrane blebbing and subsequent macropinocytosis, facilitating nutrient extraction, cell migration, and invasion, thereby contributing to tumor development. These enzymatic activities of PRLs promote the formation of membrane ruffles, membrane blebbing and subsequent macropinocytosis. Additionally, we found a correlation between PRL1/3 expression and glioma development, suggesting their involvement in glioma progression. Combining with the knowledge that PRLs have been identified to be involved in mTOR, EGFR and autophagy, here we concluded the physiological role of PRL1/3 in orchestrating the nutrient sensing, absorbing and recycling via regulating macropinocytosis through its lipid phosphatase activity. This mechanism could be exploited by tumor cells facing a nutrient-depleted microenvironment, highlighting the potential therapeutic significance of targeting PRL1/3-mediated macropinocytosis in cancer treatment.
Topics: Pinocytosis; Protein Tyrosine Phosphatases; Humans; Cell Line, Tumor; Animals; Neoplasm Proteins; Cell Movement; Mice; Cell Membrane; Phosphatidylinositols; Membrane Proteins; Cell Cycle Proteins
PubMed: 38948056
DOI: 10.7150/thno.93127 -
IScience Jun 2024The intracellular loops of G protein-coupled receptors (GPCRs) have been shown to play a key role in G protein coupling and selectivity. We recently showed that the...
The intracellular loops of G protein-coupled receptors (GPCRs) have been shown to play a key role in G protein coupling and selectivity. We recently showed that the intrinsically disordered third intracellular loop (ICL3) of β2-adrenergic receptor is dynamic and equilibrates between open and closed conformations to regulate the G protein coupling. In this study, using the extensive molecular dynamics simulations in multi-lipid bilayer models, we show that the lipid phosphatidylinositol 4,5-bisphosphate (PIP2) stabilizes the active state of β2-adrenergic receptor by keeping ICL3 in an open conformation. This stabilization results in a tilt of the receptor within the membrane. Additionally, the ganglioside lipid, GM3 interacts with extracellular loops, impacting the ligand binding site allosterically. This demonstrates the active role of the chemistry of lipids in stabilizing specific GPCR conformations.
PubMed: 38947516
DOI: 10.1016/j.isci.2024.110086 -
Quantitative phosphoproteomics reveals molecular pathway network in wheat resistance to stripe rust.Stress Biology Jul 2024Protein phosphorylation plays an important role in immune signaling transduction in plant resistance to pathogens. Wheat stripe rust, caused by Puccinia striiformis f....
Protein phosphorylation plays an important role in immune signaling transduction in plant resistance to pathogens. Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), severely devastates wheat production. Nonetheless, the molecular mechanism of wheat resistance to stripe rust remains limited. In this study, quantitative phosphoproteomics was employed to investigate the protein phosphorylation changes in wheat challenged by Pst. A total of 1537 and 2470 differentially accumulated phosphoproteins (DAPs) were identified from four early infection stage (6, 12, 18 and 24 h post-inoculation) in incompatible and compatible wheat-Pst interactions respectively. KEGG analysis revealed that Oxidative Phosphorylation, Phosphatidylinositol Signaling, and MAPK signaling processes are distinctively enriched in incompatible interaction, while Biosynthesis of secondary metabolites and RNA degradation process were significantly enriched in compatible interactions. In particular, abundant changes in phosphorylation levels of chloroplast proteins were identified, suggesting the regulatory role of photosynthesis in wheat-Pst interaction, which is further emphasized by protein-protein interaction (PPI) network analysis. Motif-x analysis identified [xxxxSPxxxx] motif, likely phosphorylation sites for defensive response-related kinases, and a new [xxxxSSxxxx] motif significantly enriched in incompatible interaction. The results shed light on the early phosphorylation events contributing to wheat resistance against Pst. Moreover, our study demonstrated that the phosphorylation levels of Nucleoside diphosphate kinase TaNAPK1 are upregulated at 12 hpi with CYR23 and at 24 hpi with CYR31. Transient silencing of TaNAPK1 was able to attenuate wheat resistance to CYR23 and CYR31. Our study provides new insights into the mechanisms underlying Pst-wheat interactions and may provide database to find potential targets for the development of new resistant varieties.
PubMed: 38945963
DOI: 10.1007/s44154-024-00170-0 -
Journal of Diabetes Investigation Jun 2024Regulatory T cells (Tregs) have protected against many cardiovascular diseases. This study was intended to explore the effect of Tregs on diabetic cardiomyopathy (DCM)...
AIMS/INTRODUCTION
Regulatory T cells (Tregs) have protected against many cardiovascular diseases. This study was intended to explore the effect of Tregs on diabetic cardiomyopathy (DCM) using a db/db mouse model.
MATERIALS AND METHODS
Eight-week-old male db/db mice were randomly divided into four groups: the control group, administered 200 μL phosphate-buffered saline; the small-dose Treg group, administered 10 Tregs; the large-dose Treg group, administered 10 Tregs; and the PC group, administered 100 μg anti-CD25 specific antibody (PC61) and 10 Tregs. After 12 weeks, mice were euthanized. Transthoracic echocardiography was carried out at the beginning and end of the experiment. Relevant basic experiments to evaluate the effects of Tregs on DCM were carried out.
RESULTS
Echocardiography showed that the impaired diastolic and systolic functions were significantly improved in mice administered large-dose Tregs. Large-dose Tregs significantly ameliorated myocardial hypertrophy and fibrosis, and decreased hypertrophic gene expression and collagen deposition. The protective effects of Tregs on diabetic hearts were associated with decreased oxidative stress, inflammatory response and apoptosis. In addition, Tregs promoted the activation of the phosphatidylinositol 3-kinase-protein kinase B signaling pathway, whereas they inhibited extracellular signal-regulated kinase 1/2 and Jun N-terminal kinase phosphorylation, which might be responsible for the cardioprotective role of Tregs against DCM.
CONCLUSIONS
Tregs ameliorated myocardial hypertrophy and fibrosis, improved cardiac dysfunction, and protected against DCM progression in db/db mice. The mechanisms involved a decrease of inflammatory response, oxidative stress and apoptosis, which might be mediated by phosphatidylinositol 3-kinase-protein kinase B and mitogen-activated protein kinase pathways. Hence, Tregs might serve as a promising therapeutic approach for DCM treatment.
PubMed: 38943657
DOI: 10.1111/jdi.14251 -
Cancer & Metabolism Jun 2024Even with systemic chemotherapy, cytoreductive surgery (CRS), and hyperthermic intraperitoneal chemotherapy (HIPEC), peritoneal metastases (PM) remain a common site of...
Even with systemic chemotherapy, cytoreductive surgery (CRS), and hyperthermic intraperitoneal chemotherapy (HIPEC), peritoneal metastases (PM) remain a common site of disease progression for colorectal cancer (CRC) and are frequently associated with a poor prognosis. The mass spectrometry (MS) method known as Matrix-Assisted Laser Desorption/Ionization - Time of Flight (MALDI-TOF) is frequently used in medicine to identify structural compounds and biomarkers. It has been demonstrated that lipids are crucial in mediating the aggressive growth of tumors. In order to investigate the lipid profiles, particularly with regard to histological distribution, we used MALDI-TOF MS (MALDI-MS) and MALDI-TOF imaging MS (MALDI-IMS) on patient-derived tumor organoids (PDOs) and PM clinical samples. According to the MALDI-IMS research shown here, the predominant lipid signature of PDOs in PM tissues, glycosphingolipid (GSL) sulfates or sulfatides, or STs, is unique to the areas containing tumor cells and absent from the surrounding stromal compartments. Bioactive lipids are derived from arachidonic acid (AA), and AA-containing phosphatidylinositol (PI), or PI (18:0-20:4), is shown to be highly expressed in the stromal components. On the other hand, the tumor components contained a higher abundance of PI species with shorter and more saturated acyl chains (C34 and C36 carbons). The cellular subversion of PI and ST species may alter in ways that promote the growth, aggressiveness, and metastasis of tumor cells. Together, these findings suggest that the GSL/ST metabolic programming of PM may contain novel therapeutic targets to impede or halt PM progression.
PubMed: 38943216
DOI: 10.1186/s40170-024-00345-3 -
Nature Communications Jun 2024Cancer treatment continues to shift from utilizing traditional therapies to targeted ones, such as protein kinase inhibitors and immunotherapy. Mobilizing dendritic...
Cancer treatment continues to shift from utilizing traditional therapies to targeted ones, such as protein kinase inhibitors and immunotherapy. Mobilizing dendritic cells (DC) and other myeloid cells with antigen presenting and cancer cell killing capacities is an attractive but not fully exploited approach. Here, we show that PIKFYVE is a shared gene target of clinically relevant protein kinase inhibitors and high expression of this gene in DCs is associated with poor patient response to immune checkpoint blockade (ICB) therapy. Genetic and pharmacological studies demonstrate that PIKfyve ablation enhances the function of CD11c cells (predominantly dendritic cells) via selectively altering the non-canonical NF-κB pathway. Both loss of Pikfyve in CD11c cells and treatment with apilimod, a potent and specific PIKfyve inhibitor, restrained tumor growth, enhanced DC-dependent T cell immunity, and potentiated ICB efficacy in tumor-bearing mouse models. Furthermore, the combination of a vaccine adjuvant and apilimod reduced tumor progression in vivo. Thus, PIKfyve negatively regulates the function of CD11c cells, and PIKfyve inhibition has promise for cancer immunotherapy and vaccine treatment strategies.
Topics: Animals; Humans; Dendritic Cells; Mice; Phosphatidylinositol 3-Kinases; CD11c Antigen; Morpholines; Cell Line, Tumor; Immunotherapy; Neoplasms; Mice, Inbred C57BL; Female; Immune Checkpoint Inhibitors; NF-kappa B; T-Lymphocytes; Protein Kinase Inhibitors; Hydrazones; Pyrimidines
PubMed: 38942798
DOI: 10.1038/s41467-024-48931-9 -
Science Advances Jun 2024The formation of vascular niche is pivotal during the early stage of peripheral nerve regeneration. Nevertheless, the mechanisms of vascular niche in the regulation of...
The formation of vascular niche is pivotal during the early stage of peripheral nerve regeneration. Nevertheless, the mechanisms of vascular niche in the regulation of peripheral nerve repair remain unclear. Netrin-1 (NTN1) was found up-regulated in nerve stump after peripheral nerve injury (PNI). Herein, we demonstrated that NTN1-high endothelial cells (NTN1+ECs) were the critical component of vascular niche, fostering angiogenesis, axon regeneration, and repair-related phenotypes. We also found that NTN1+EC-derived exosomes (NTN1 EC-EXO) were involved in the formation of vascular niche as a critical role. Multi-omics analysis further verified that NTN1 EC-EXO carried a low-level expression of let7a-5p and activated key pathways associated with niche formation including focal adhesion, axon guidance, phosphatidylinositol 3-kinase-AKT, and mammalian target of rapamycin signaling pathway. Together, our study suggested that the construction of a pre-regenerative niche induced by NTN1 EC-EXO could establish a beneficial microenvironment for nerve repair and facilitate functional recovery after PNI.
Topics: Netrin-1; Exosomes; Nerve Regeneration; Animals; Endothelial Cells; Peripheral Nerve Injuries; Mice; Neovascularization, Physiologic; Signal Transduction; Humans; Peripheral Nerves
PubMed: 38941462
DOI: 10.1126/sciadv.adm8454 -
European Journal of Cancer (Oxford,... Jun 2024Phosphatidylinositol 3-kinase (PI3-K) signalling pathway is a crucial path in cancer for cell survival and thus represents an intriguing target for new paediatric... (Review)
Review
Phosphatidylinositol 3-kinase (PI3-K) signalling pathway is a crucial path in cancer for cell survival and thus represents an intriguing target for new paediatric anti-cancer drugs. However, the unique clinical toxicities of targeting this pathway (resulting in hyperglycaemia) difficulties combining with chemotherapy, rarity of mutations in childhood tumours and concomitant mutations have resulted in major barriers to clinical translation of these inhibitors in treating both adults and children. Mutations in PIK3CA predict response to PI3-K inhibitors in adult cancers. The same mutations occur in children as in adults, but they are significantly less frequent in paediatrics. In children, high-grade gliomas, especially diffuse midline gliomas (DMG), have the highest incidence of PIK3CA mutations. New mutation-specific PI3-K inhibitors reduce toxicity from on-target PI3-Kα wild-type activity. The mTOR inhibitor everolimus is approved for subependymal giant cell astrocytomas. In paediatric cancers, mTOR inhibitors have been predominantly evaluated by academia, without an overall strategy, in empiric, mutation-agnostic clinical trials with very low response rates to monotherapy. Therefore, future trials of single agent or combination strategies of mTOR inhibitors in childhood cancer should be supported by very strong biological rationale and preclinical data. Further preclinical evaluation of glycogen synthase kinase-3 beta inhibitors is required. Similarly, even where there is an AKT mutation (∼0.1 %), the role of AKT inhibitors in paediatric cancers remains unclear. Patient advocates strongly urged analysing and conserving data from every child participating in a clinical trial. A priority is to evaluate mutation-specific, central nervous system-penetrant PI3-K inhibitors in children with DMG in a rational biological combination. The choice of combination, should be based on the genomic landscape e.g. PTEN loss and resistance mechanisms supported by preclinical data. However, in view of the very rare populations involved, innovative regulatory approaches are needed to generate data for an indication.
PubMed: 38936103
DOI: 10.1016/j.ejca.2024.114145 -
PloS One 2024To investigate the therapeutic effect and mechanism of sivelestat sodium on acute lung injury (AIL).
OBJECTIVE
To investigate the therapeutic effect and mechanism of sivelestat sodium on acute lung injury (AIL).
METHODS
A rat model for ALI/acute respiratory distress syndrome (ALI/ARDS) was established. Pathological examination of lung tissue was conducted to assess lung injury. Blood gas in the arteries was measured using a blood analyzer. Changes in PaO2, PaO2/FiO2, and lung wet/dry (W/D) weight ratio were carefully compared. ELISA assay was conducted to estimate cell adhesion and inflammation response. Finally, real-time reverse transcription polymerase chain reaction and western blotting assay was used to determine the activation of PI3K/AKT/mTOR pathway.
RESULTS
ARDS in vivo model was successfully constructed by LPS injection. Compared with the sham group, PaO2 and PaO2/FiO2 were significantly lower in the vehicle group, while the lung W/D ratio, the lung injury score, NE, VCAM-1, IL-8 andTNF-αwere significantly increased. After treatment with different doses of sivelestat sodium, we found PaO2, PaO2/FiO2 were prominently increased, while the lung W/D ratio, the lung injury score, NE, VCAM-1, IL-8, TNF-α levels were decreased in the dose-dependent manner. Meanwhile, compared with the vehicle group, the expression levels of Bax, PI3K, Akt and mTOR were significantly lower, and the expression of Bcl-2 was significantly higher after injection with sivelestat sodium.
CONCLUSION
Sivelestat sodium has an interventional effect on ALI in sepsis by inhibiting the PI3K/AKT/mTOR signalling pathway.
Topics: Animals; TOR Serine-Threonine Kinases; Acute Lung Injury; Signal Transduction; Proto-Oncogene Proteins c-akt; Phosphatidylinositol 3-Kinases; Rats; Male; Glycine; Sulfonamides; Rats, Sprague-Dawley; Lung; Disease Models, Animal
PubMed: 38935660
DOI: 10.1371/journal.pone.0302721