Signal-regulated Kinase Signaling Pathway Research Articles

ZDHHC2 promoted antimycobacterial responses by selective autophagic degradation of B-RAF and C-RAF in macrophages.

S-Palmitoylation is a reversible post-translational modification involving saturated fatty acid palmitate-to-cysteine linkage in the protein, which guides many aspects of macrophage physiology in health and disease. However, the precise role and underlying mechanisms of palmitoylation in Mycobacterium tuberculosis infection of macrophages remain elusive. Here, we found that M. tuberculosis infection induced the expression of zinc-finger DHHC domain-type palmitoyl-transferases (ZDHHCs), particularly ZDHHC2, in mouse macrophages. Furthermore, ZDHHC2 deficiency in mouse macrophages impaired the immunity against M. tuberculosis and reduced the production of various proinflammatory cytokines. Mechanistic studies revealed the involvement of ZDHHC2 in mediating the palmitoylation of B-RAF and C-RAF, affecting their autophagic degradation and stabilizing protein levels. The increased abundance of B-RAF and C-RAF subsequently increases the activity of the extracellular signal-regulated kinase (ERK) signaling pathway, affecting the survival of M. tuberculosis within macrophages. These findings suggest that ZDHHC2 is a potential target for treating tuberculosis.

DOP035 Anti-inflammatory potential of novel tethered agonists of the adhesion G protein-coupled receptor F5

Abstract Background An accumulating data suggest that the adhesion G protein-coupled receptor F5 (ADGRF5) is fundamental for human health and diseases1-3. It was noted that ADGRF5 mediates immune response in cancers but its impact on colitis development is still unknown. Moreover, recent findings identified mature tethered agonist of ADGRF5 which corresponds to Stachel sequence of this receptor4. The purpose of this work was to design peptides corresponding to Stachel sequence able to activate ADGRF5 with higher activity than the mature ADGRF5 tethered agonist and evaluate them in colitis model. Methods Single amino acid substitutions in the mature ADGRF5 tethered agonist sequence combined with calcium accumulation and inositol phosphate conversion assays as well as ADGRF5 overexpressing cells were used to identify novel ADGRF5 tethered agonists. The downstream signalling pathway induced by ADGRF5 tethered agonists was estimated using Western blot technique. In vivo studies employing murine model of colitis induced by dextran sulphate sodium salt (DSS) administration were performed. Anti-inflammatory potential of novel ADGRF5 tethered agonists was assessed using macroscopic and microscopic damage score as well as total length of inflamed colon. Results The comparison of mature and modified ADGRF5 tethered agonist activity documented that substitution of the amino acids in position 11 and 13 improves their activity in ADGRF5 overexpressing cells when compared to wild-type cells. In vitro approach using calcium accumulation and inositol phosphate conversion assays revealed that novel ADGRF5 tethered agonists are characterized by 6-fold lower EC50 value than parent ADGRF5 tethered agonist. Moreover, our novel ADGRF5 tethered agonists are able to induce phosphorylation of protein kinase A and B as well as extracellular signal-regulated kinase signalling pathways in time and dose-dependent manner. Finally, administration of novel ADGRF5 tethered agonists in the murine model of colitis led to a significant improvement of macroscopic and microscopic damage score compared to animals treated with mature ADGRF5 tethered agonist. Additionally, the colons of mice treated with novel ADGRF5 tethered agonists but not with mature ADGRF5 tethered agonist were characterized by reduction of total length of inflammation and improvement of colon architecture. Conclusion We found critical positions in the Stachel sequence of ADGRF5 agonists which are required for their activity. New ADGRF5 tethered agonists displayed anti-inflammatory action highlighting that modulation of ADGRF5 activity may serve as an attractive target in colitis treatment.

Multifunctions of Sustainable Chondroitin Sulfates with Predominant Subtypes and Low Molecular Weights on Neurite Outgrowth.

Three chondroitin sulfate (CS) analogues with predominant subtypes (A, C, and E) were prepared from engineered Escherichia coli K4 combined with regioselective sulfation. CS with the designed sulfates as the main components was characterized by nuclear magnetic resonance spectroscopy, elementary analysis, and disaccharide analysis. CS prepared from the native or degraded capsular polysaccharide had molecular weights of 1.55 × 104-1.90 × 104 and 5.6 × 103-7.4 × 103, respectively. We found that CS with dual sulfates promoted the outgrowth and survival of hippocampal neurons, whereas CS with monosulfate had an inhibitory effect. CS interacted with the nerve growth factor (NGF) and tyrosine kinase (TrkA), which activated the extracellular signal-regulated kinase (ERK) signaling pathway to modulate the outgrowth of hippocampal neurons. This work clarified the multiple effects of CS on neurite outgrowth based on nonanimal-sourced glycosaminoglycans, which would benefit efforts in discovering their novel functions and therapeutic applications.

IL-17A mediates inflammation-related retinal pigment epithelial cells injury via ERK signaling pathway.

To investigate whether interleukin-17A (IL-17A) gets involved in the mechanisms of inflammation-related retinal pigment epithelium (RPE) cells injury and its significance in age-related macular degeneration (AMD). A sodium iodate (NaIO3) mouse model as well as IL-17A -/- mice were established. The effects of inflammatory cytokines in RPE cells and retinal microglia before and after NaIO3 modeling in vivo and in vitro, were investigated using immunofluorescence, immunoprotein blotting, and quantitative real-time fluorescence polymerase chain reaction (qRT-PCR), respectively. Interventions using recombinant IL-17A protein (rIL-17A) or IL-17A neutralizing antibody (IL-17A NAb) were used to observe the subsequent differences in fundus, fundus photography and optical coherence tomography (OCT), cell viability, and expression of oxidative stress-related markers before and after modeling, and to screen for key signaling pathways. In the scenario of NaIO3 stimulation, RPE cells obviously tended to degenerate. Simultaneously proliferation and activation of retinal microglia was confirmed in NaIO3-stimulated mice, whereas such effects induced by NaIO3 were significantly ameliorated with IL-17A NAb intervention or in IL-17A -/- mice. In addition, IL-17A promoted the proliferation and activation of microglia as well as oxidative damage and the secretion of inflammatory cytokines alongside NaIO3-induced damage in RPE cells in vivo and ex vivo. Meanwhile, the extracellular signal-regulated kinase (ERK) signaling pathway was shown to be participated in the regulation of NaIO3-induced RPE cells injury mediated by IL-17A in vivo and ex vivo, as IL-17A-induced inflammatory cytokines release in the NaIO3 model was alleviated after blocking the ERK pathway. IL-17A probably promotes the NaIO3-induced RPE cells injury through exacerbating inflammation in terms of retinal microglia activation and inflammatory cytokines release via ERK signaling pathway. Inhibition of IL-17A may be a new potential target for dry AMD treatment.

Analysis of Fibroblast Growth Factor 2 Impact and Mechanism on Broncho-Pulmonary Dysplasia.

Epithelial-mesenchymal transition (EMT) of alveolar epithelial cells is an important mechanism for the onset and development of broncho-pulmonary dysplasia (BPD).The role of FGF-2 in BPD is currently unclear. The aim of our study is to investigate the expression of FGF-2 in lung tissue of BPD mice, to further clarify the effect of FGF-2 on EMT in alveolar epithelial cells and to actively search for possible signaling pathways. The BPD model was induced by exposure to hyperoxia. Lung tissue samples were collected and Hematoxylin and eosin (HE) staining was used to determine the modelling effect. Quantitative Real-time Polymerase Chain Reaction (QRT-PCR), immunohistochemistry were used to detect FGF-2 expression in BPD mice. To further investigate the effect of FGF-2 supplementation and deficiency on EMT in alveolar epithelial cells, A549 cells were cryopreserved, resuspended, cultured and passaged. Transforming growth factor-β1 (TGFβ1) was used to induce EMT. FGF-2 small interfering RNA fragments were synthesised and screened. Fbroblast growth factor receptor1 (FGFR1) expression was inhibited by BGJ398. (3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H tetrazolium) (MTS) assay was used to detect the effect of FGF-2 and Infigratinib (BGJ398) on cell proliferation. We used qRT-PCR and Western blot to detect the expression of epithelial cell markers, mesenchymal cell markers and EMT-related signaling pathway proteins. Our results showed that the successful established hyperoxia mice model were characteristic by BPD. Hyperoxia decreased FGF-2 on day 4, upregulated FGF-2 on day 21, which resulted in EMT. In vitro, we found that FGF-2 alone increased the expression of mesenchymal markers, decreased the expression of epithelial markers and activated Phosphatidylinositol 3-kinase/Protein kinase B (PI3K/AKT), Small mother against decapentaplegic (Smad), mitogen-activated protein kinase (P38) and extracellular signal-regulated kinase (ERK) signaling pathways. FGF-2 could not reverse but synergistically promote TGF-β1-induced EMT of alveolar epithelial cells. Silencing FGF-2 increased the expression of epithelial marker E-cadherin, inhibited the PI3K/AKT, Smad, and P38 signaling pathways activated by TGF-β1, but activated ERK signaling. FGF-2 receptor inhibitor BGJ398 reversed TGF-β1-induced EMT, decreased the expression of FGFR1, and inhibited ERK signaling pathway activation. FGF2 was closely associated with EMT in BPD mice. Both high and low levels of FGF2 promoted EMT in A549. The FGF-2 receptor inhibitor BGJ398 reversed TGF-β1-induced EMT in A549 by inhibiting the FGFR1/P-ERK signaling pathway.

General anesthesia induces acute cell-free DNA methylation changes in peripheral blood.

Short-term and long-term adverse events could occur after general anesthesia (GA) and the specific mechanism driving these effects has not yet been well-characterized. In this study, we aimed to evaluate the global effect of GA on DNA methylation in the cell-free DNA (cfDNA) of surgical lung-nodule patients. This large retrospective cohort study enrolled 1,006 surgical lung nodule patients (529 pre-anesthesia, and 477 post-anesthesia). Methylation profiles of the cfDNA isolated from plasma were analyzed by targeted bisulfite sequencing using an enrichment panel covering 12,899 biologically informative methylation regions and 105,844 CpG sites. By comparing the pre-anesthesia to the post-anesthesia group, a total of 4,562 differentially methylated regions (DMRs) were identified as GA-induced DMRs. Pathway enrichment analysis annotated with cellular processes including pattern specification process, head/heart/bone/tissues development and morphogenesis pathways, cell-adhesion, extra-cellular matrix (ECM) remodeling pathways, and signaling pathways including PI3K-AKT pathway, Ca2+ dependent pathway and RAS/extracellular signal-regulated kinase (RAS/ERK) signaling pathway. Prediction models using 20 DMR markers were derived using Random Forest, which could accurately predict biochemical indicators for post-operative abnormal coagulation function including activated-partial-thromboplastin-time [APTT, area under curve (AUC) 0.81], international normalized ratio (INR, AUC 0.87), D-dimer (AUC 0.82), neutrophil (AUC 0.84) and monocyte (AUC 0.79). Low methylation level in one of the top DMR markers, cg02032606 (DLX-4 gene), was found to be associated with worse overall survival in both lung adenocarcinoma and squamous carcinoma patients. This study demonstrated that GA could result in acute DNA methylation changes, which were associated with tissue damage and repair responses. These GA-induced methylation changes were associated with postoperative coagulation functions and could serve as a promising predictive biomarker for coagulation disorders after surgery.

IL-17A is a key regulator of neuroinflammation and neurodevelopment in cognitive impairment induced by sevoflurane

Increasing numbers of animal studies have shown that repeat sevoflurane exposure during developmental stage may lead to long-term cognitive impairment. Nevertheless, the exact pathogenesis remains unclear. Interleukin 17A (IL-17A) has been associated with cognitive decline in various neurological disorders. Here we found that the expression of IL-17A was up-regulated in hippocampus of sevoflurane exposed neonatal mice. Genetic deletion of IL-17A or inhibition of IL-17A improved behavioral function and down-regulated neuroinflammation related genes, interleukin 1β (IL-1β), interleukin 6 (IL-6), Nicotinamide adenine dinucleotide phosphate(NADPH) oxidase 2 (NOX2) and NADPH oxidase 4 (NOX4) in hippocampus of sevoflurane exposed neonatal mice. Moreover, negative regulation of IL-17A/Interleukin 17A receptor(IL-17RA) promoted the extracellular signal-regulated protein kinase (ERK) signaling pathway and nucleation of cyclic adenosine monophosphate (cAMP) response element-binding (CREB) in neurons of cognitive impaired mice. Knockdown of IL-17A in vivo identified neurons-localized IL-17A as a major factor in neuroinflammation and neurodevelopment. Collectively, our results suggested that IL-17A was required for the pathogenesis of neuroinflammatory response and identify IL-17A as a potential therapeutic target for cognitive impairment exposed by general anesthetics during infancy.

Utility of patient-derived xenografts to evaluate drug sensitivity and select optimal treatments for individual non-small-cell lung cancer patients

BackgroundPatient-derived xenograft (PDX) is currently considered a preferred preclinical model to evaluate drug sensitivity, explore drug resistance mechanisms, and select individualized treatment regimens.MethodsHistopathological examination, immunohistochemistry and whole-exome sequencing confirmed similarity between our PDX tumors and primary tumors in terms of morphology and genetic characteristics. The drug reactivity of the PDX tumor was validated in vivo. The mechanisms of acquired resistance to Osimertinib PDX tumors were investigated by WES and WB.ResultsWe successfully established 13 NSCLC-PDXs derived from 62 patients, including eight adenocarcinomas, four squamous-cell carcinoma, and one large-cell neuroendocrine carcinoma. Histological subtype and clinical stage were significant factors affecting the successful PDXs establishment. The treatment responses to conventional chemotherapy in PDXs were entirely consistent with that of their corresponding patients. According to the genetic status of tumors, more appropriate targeted agents were selected in PDXs for their corresponding patients as alternative treatment options. In addition, a PDX model with acquired resistance to osimertinib was induced, and the overactivation of RAS mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase (ERK) signaling pathway caused by the dual-specificity phosphatase 6 (DUSP6) M62I mutation was found to play a key role in the development of osimertinib resistance. Trametinib, a specific inhibitor of the MAPK-ERK pathway significantly slowed down the tumor growth in osimertinib-resistant PDX models, providing an alternative treatment in patients after osimertinib failure.

Differential Effects of Extracellular Vesicles from Two Different Glioblastomas on Normal Human Brain Cells.

Background/Objectives: Glioblastomas (GBMs) are dreadful brain tumors with abysmal survival outcomes. GBM extracellular vesicles (EVs) dramatically affect normal brain cells (largely astrocytes) constituting the tumor microenvironment (TME). We asked if EVs from different GBM patient-derived spheroid lines would differentially alter recipient brain cell phenotypes. This turned out to be the case, with the net outcome of treatment with GBM EVs nonetheless converging on increased tumorigenicity. Methods: GBM spheroids and brain slices were derived from neurosurgical patient tissues following informed consent. Astrocytes were commercially obtained. EVs were isolated from conditioned culture media by ultrafiltration, concentration, and ultracentrifugation. EVs were characterized by nanoparticle tracking analysis, electron microscopy, biochemical markers, and proteomics. Astrocytes/brain tissues were treated with GBM EVs before downstream analyses. Results: EVs from different GBMs induced brain cells to alter secretomes with pro-inflammatory or TME-modifying (proteolytic) effects. Astrocyte responses ranged from anti-viral gene/protein expression and cytokine release to altered extracellular signal-regulated protein kinase (ERK1/2) signaling pathways, and conditioned media from EV-treated cells increased GBM cell proliferation. Conclusions: Astrocytes/brain slices treated with different GBM EVs underwent non-identical changes in various omics readouts and other assays, indicating "personalized" tumor-specific GBM EV effects on the TME. This raises concern regarding reliance on "model" systems as a sole basis for translational direction. Nonetheless, net downstream impacts from differential cellular and TME effects still led to increased tumorigenic capacities for the different GBMs.

Bushen Huoxue Decoction regulates ADSCs-Exos to affect nucleus pulposus cell apoptosis and ERK signaling pathway in intervertebral disc degeneration

This study aims to investigate the effects of Bushen Huoxue Decoction regulating adipose-derived stem cells(ADSCs)-exosomes(Exos) on the apoptosis of intervertebral disc nucleus pulposus cells(NPCs) and extracellular signal-regulated kinase(ERK) signaling pathway. Tert-butyl hydrogen peroxide(TBHP)-induced NPCs were divided into control, model, drug-containing serum, blank Exos, normal serum Exos, and drug-containing serum Exos groups. Cell viability and proliferation were examined by the CCK-8 assay and EdU staining, respectively. The cell cycle and apoptosis were evaluated by flow cytometry. Enzyme-linked immunosorbent assay was employed to measure the levels of interleukin(IL)-1β, tumor necrosis factor(TNF)-α, and IL-6. The mRNA levels of aggrecan, collagen type Ⅱ alpha 1 chain(COL2A1), and ERK were determined by qRT-PCR, and the protein levels of aggrecan, COL2A1, and p-ERK were determined by Western blot. The results showed that compared with the model group, the treatments with drug-containing serum, blank Exos, and normal serum Exos enhanced the viability and proliferation of NPCs, decreased the proportion of cells in the G_0/G_1 phase, increased the proportion of cells in the S phase, reduced apoptosis, lowered the levels of IL-1β, TNF-α, and IL-6, up-regulated the mRNA and protein levels of aggrecan and COL2A1, and down-regulated the mRNA level of ERK and the protein level of p-ERK. Compared with the drug-containing serum, blank Exos, and normal serum Exos groups, the treatment with drug-containing serum Exos enhanced the viability and proliferation of NPCs, decreased the proportion of cells in the G_0/G_1 phase, increased the cells in the S phase, reduced apoptosis, lowered the levels of IL-1β, TNF-α, and IL-6, up-regulated the mRNA and protein levels of aggrecan and COL2A1, and down-regulated the mRNA level of ERK and the protein level of p-ERK. The results confirmed that the Exos secreted by ADSCs after treatment with Bushen Huoxue Decoction-containing serum promoted the proliferation of degenerated NPCs, inhibited apoptosis and the expression of inflammatory mediators, and promoted the production of proteoglycans and collagen, thus delaying the progression of intervertebral disc degeneration, the mechanism of which was related to the regulation of the ERK signaling pathway.

ARL8B promotes hepatocellular carcinoma progression and inhibits antitumor activity of lenvatinib via MAPK/ERK signaling by interacting with RAB2A

Tumor recurrence and metastasis are important factors affecting postoperative survival in hepatocellular carcinoma (HCC) patients. ADP Ribosylation factor-like GTPase 8B (ARL8B) plays a crucial role in many biological processes, including lysosomal function, immune response, and cellular communication, all of which are related to the occurrence and development of tumors. However, its role in HCC remains unclear. Herein, we revealed that ARL8B is consistently elevated in HCC tissues compared to normal liver tissues, suggesting an unfavorable outcome in HCC patients. Increased ARL8B levels promoted the malignant phenotype of HCC in vitro and in vivo. Notably, ARL8B also induced epithelial-to-mesenchymal transition (EMT) in HCC cells. Mechanistically, the results of bioinformatics analysis combined with mass spectrometry revealed the potential downstream target molecule RAB2A of ARL8B. ARL8B directly interacted with RAB2A and increased the levels of GTP-bound RAB2A, thereby contributing to the activation of the extracellular signal-regulated kinase (ERK) signaling pathway. Interestingly, knockout of ARL8B in Hep3B cells enhanced the antitumor activity of lenvatinib in vitro and in vivo. Furthermore, AAV-shARL8B enhanced the inhibition of HCC growth through lenvatinib, providing new insights into its mechanism of action in lenvatinib-insensitive patients. In conclusion, ARL8B promotes the malignant phenotype of HCC and EMT via RAB2A mediated activation of the MAPK/ERK signaling pathway and is expected to be a valuable prognostic indicator and therapeutic target for HCC patients.

Effects of Proteasome 20S Subunit Beta 8 on Proliferation,Migration,and Invasion of Clear Cell Renal Cell Carcinoma Cells via Mitogen-Activated Protein Kinase Kinase/Extracellular Signal-Regulated Kinase Signaling Pathway

Objective To explore the effects of proteasome 20S subunit beta 8 (PSMB8) on the proliferation,migration,and invasion of clear cell renal cell carcinoma (ccRCC) cells and whether PSMB8 promotes tumor progression by activating the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway. Methods The Cancer Genome Atlas was employed to analyze the mRNA levels of PSMB8 in ccRCC and normal tissue,and the expression levels of PSMB8 in ccRCC tissue and cells were determined by real-time quantitative PCR,Western blotting,and immunohistochemistry.Furthermore,the cell lines with stable overexpression and knockdown of PSMB8 were constructed.The CCK-8 assay and colony formation assay were employed to examine the cell proliferation,and the wound healing assay and Transwell assay were employed to examine the invasion and migration of cells.Kyoto Encyclopedia of Genes and Genomes pathway enrichment was performed to analyze the co-expressed genes of PSMB8.Western blotting was used to measure the phosphorylation levels of the proteins in the MEK/ERK signaling pathway.Finally,the rescue experiment was carried out with the ERK agonist C16-PAF. Results Compared with the normal tissue,the ccRCC tissue showed up-regulated mRNA and protein levels of PSMB8 (both P<0.001),which were associated with the TNM stage of patients with ccRCC (P<0.001).Compared with the negative control group,overexpression of PSMB8 promoted the proliferation (P=0.021,P=0.039),migration and invasion (all P<0.001) of 786-O and ACHN cells,and the knockdown of PSMB8 inhibited the proliferation (P=0.022,P=0.005),migration and invasion (all P<0.001) of 786-O and ACHN cells.The pathway enrichment analysis of co-expressed genes of PSMB8 predicted the mitogen-activated protein kinase signaling pathway (P<0.001).After the knockdown of PSMB8,786-O and ACHN cells showed lowered phosphorylation levels of MEK1/2 (P=0.017,P=0.016) and ERK1/2 (P=0.010,P=0.040) and down-regulated transcription levels of ERK downstream factors c-Myc (P=0.043,P=0.038),c-Fos (P=0.025,P=0.008),and CyclinD1 (P=0.006,P=0.047).Compared with the ERK agonist C16-PAF group,the PSMB8 knockdown + C16-PAF group showed inhibited proliferation (P=0.003,P=0.002),migration and invasion (all P<0.001) of 786-O and ACHN cells. Conclusion PSMB8 may promote the proliferation,migration,and invasion of ccRCC cells by activating the MEK/ERK signaling pathway.

FUT6 Suppresses the Proliferation, Migration, Invasion, and Epithelial-Mesenchymal Transition of Esophageal Carcinoma Cells via the Epidermal Growth Factor Receptor/Extracellular Signal-Regulated Kinase Signaling Pathway.

Esophageal cancer (ESCA) is a high-incidence disease worldwide, of which the 5-year survival rate remains dismal since the cellular basis of ESCA remains largely unclear. Herein, we attempted to examine the manifestation of fucosyltransferase-6 (FUT6) in ESCA and the associated mechanisms. The GSE161533 dataset was used to analyze a crucial gene in ESCA. The expression of FUT6 was investigated in normal esophageal epithelial cells and ESCA cell lines. Following FUT6 knockdown or overexpression, cell proliferation, migration, invasion, and levels of epithelial–mesenchymal transition (EMT)-related and epidermal growth factor receptor (EGFR)/extracellular signal-regulated kinase (ERK) signaling pathway-related proteins were evaluated using CCK-8, Transwell, and Western blotting with antibodies against EGFR, p-EGFR, E-cadherin, Vimentin, N-cadherin, ERK1/2, and p-ERK1/2), respectively. EGF was administered to stimulate the EGFR/ERK signaling pathway, followed by the assessment of cellular activity. Database analysis revealed that FUT6 was downregulated in the ESCA cells. Our study indicated that FUT6 is suppressed in various ESCA cell lines. Moreover, cell proliferation, invasion, migration, and EMT-related protein levels were conspicuously enhanced or restrained by FUT6 disruption or overexpression. FUT6 overexpression suppressed the malignant activities of the cells when stimulated by EGF, including inhibition of cell growth, movement, invasion, and EMT advancement, as well the reduction the levels of EGFR/ERK pathway proteins. In conclusion, FUT6 can suppress the EGFR/ERK signaling pathway activated by EGF, leading to the potential attenuation of ESCA cell proliferation, invasion, migration, and EMT.

Jaranol Loaded in Ferroferric Oxide Nanoparticles Inhibits the Activities of Liver Cancer Cell Through Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase Signaling Pathway

Liver cancer is highly aggressive and the MEK/ERK signaling regulates tumor cell proliferation and metastasis. Jaranol is a natural product with anti-proliferative and anti-metastatic effects in several tumors. However, its interaction with the MEK/ERK pathway in liver cancer is unclear. This study explores whether ferroferric oxide nanoparticles-loaded Jaranol inhibits proliferation and metastasis in liver cancer cell Hep3B by regulating MEK/ERK signaling, and its underlying mechanism. Fe3O4-Jaranol nanoparticles were prepared and used in Hep3B experiments to observe the biological efficacy of Fe3O4-Jaranol, and further explore its effect and mechanism on the MEK/ERK pathway using PCR, WB, etc. Fe3O4-Jaranol were successfully prepared with a certain tumor suppressor effect in liver cancer. The expression of MEK/ERK was increased in liver cancer. Inhibiting its pathway activity suppressed the development of liver cancer. Trametinib and C16-PAF were used to inhibit Hep3B respectively. MEK expression in cells treated with Trametinib was reduced accompanied by a low expression of ERK, while the expression of MEK and ERK levels in the C16-PAF group showed an opposite trend, indicating that Trametinib, C16-PAF successfully intervened on MEK and ERK. Further analysis of the activity of Hep3B cells found that the proliferation ability of the Trametinib group was significantly inhibited. Fe3O4-Jaranol significantly inhibited liver cancer cell Hep3B and this effect was accomplished by inhibiting MEK/ERK signaling, causing tumor cell proliferation to be restricted and reducing the ability to metastasize. This research result provides strong evidence for a deep understanding of the mechanism of Jaranol in treating liver cancer, so as to better guide clinical practice.

Neural Development and Repair Induced by Femtosecond Laser Stimulation.

Dendritic spines function as postsynaptic sites, receiving excitatory signals from presynaptic axons. The synaptic plasticity of spines underlies the refinement of neuronal circuits. Neural cognitive disorders are commonly associated with the impairment and elimination of dendritic spines. In this study, we report an all-optical method to activate dendritic spine growth and regeneration by a single short flash of femtosecond laser stimulation. The inhibited development and loss of spines can be rescued by a transient illumination of the laser inside a micrometer region of the soma by activating the extracellular signal-regulated kinase (ERK) signaling pathway. The rescued neurons exhibit function. Hence we provide a potential noninvasive method for the regeneration of dendritic spines.

Decoding the Genetic Threads of Disc Degeneration

Abstract Degenerative disc disease (DDD) is a prevalent musculoskeletal disorder characterized by the progressive degeneration of intervertebral discs, often leading to chronic low back pain and disability. While the etiology of DDD is multifactorial, genetic factors play a significant role in disease susceptibility and progression. This review provides a comprehensive overview of the genetic aspects of DDD, summarizing previously reported genes and variations associated with the disease. Through an analysis of animal studies and molecular pathways implicated in disc degeneration, including the lipid kinase phoshoinositide-3-kinase signaling pathway (PI3K-Akt), mitogen-activated protein kinase/extracellular signal-regulated kinase signaling pathway (MAPK-ERK), Wingless-related integration (Wnt)/β-catenin, Sonic Hedgehog (Shh), and mammalian target of rapamycin (mTOR) pathways, this review elucidates the intricate interplay between genetic factors and disc pathology. Several candidate genes have been identified in association with DDD, including those involved in extracellular matrix regulation, inflammation, and cell signaling. Genome-wide association studies have further expanded our understanding of the genetic architecture underlying DDD, revealing novel susceptibility loci and pathways. Animal studies utilizing genetically modified models have provided valuable insights into the molecular mechanisms driving disc degeneration and have validated the relevance of specific genetic pathways in disease pathogenesis. Understanding the genetic basis of DDD holds promise for identifying individuals at risk, developing predictive biomarkers, and informing personalized treatment approaches. Furthermore, elucidating the molecular pathways involved in disc degeneration may lead to the identification of novel therapeutic targets for DDD management. Overall, this review consolidates current knowledge on DDD genetics and pathways, providing a foundation for future research endeavors aimed at unraveling the intricate genetic mechanisms underlying this prevalent musculoskeletal disorder.

MAPK signaling pathway participates in the regulation of intestinal phosphorus and calcium absorption in broiler chickens via 1,25-dihydroxyvitamin D3

Four experiments were performed to investigate the role of the mitogen-activated protein kinase (MAPK) signaling pathway in intestinal absorption of phosphorus (P) and calcium (Ca) in broiler chickens. Experiment 1 assessed how dietary levels of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) influence the gene expression of intestinal P and Ca transporters in broilers. Experiment 2 evaluated the effects of 1,25(OH)2D3 administered via intraperitoneal injection on the extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (p38MAPK) signaling pathways. Experiments 3 and 4 investigated the effect of ERK and p38MAPK inhibitors on the expression of intestinal P and Ca transporters. The findings demonstrated that broilers (1-21 days old) fed a 1,25(OH)2D3-deficient diet (0.625 µg/kg) exhibited reduced body weight, tibia P and Ca levels, and mRNA levels of P transporters (NaPi-IIb, PiT-1, and PiT-2), Ca transporters (NCX1, PMCA1b, and CaBP-D28k), vitamin D receptors (VDR), ERK, and p38MAPK in the duodenum (Experiment 1) (P < 0.05). By comparison, the growth, bone quality, and mRNA levels of genes (except for duodenal NaPi-IIb) in broilers were similar to those in broilers fed the control diet when dietary 1,25(OH)2D3 was adequate (5 µg/kg) (Experiment 1) (P > 0.05). After intraperitoneal injection of 1,25(OH)2D3, the mRNA level of jejunal NaPi-IIb and the protein level of p-p38MAPK/t-p38MAPK in broilers (9-14 days old) decreased (P < 0.05), whereas the mRNA level of CaBP-D28k and the protein level of p-ERK/t-ERK increased (Experiment 2) (P < 0.05). The mRNA and protein expression of jejunal NaPi-IIb and the protein expression of CaBP-D28k in broilers (9-17 days old) treated with the ERK inhibitor PD98059 were greater than those in the control group (Experiment 3) (P < 0.05). Similarly, compared with control broilers, broilers (9-17 days old) treated with the p38MAPK inhibitor SB203580 showed elevated mRNA expression of jejunal NaPi-IIb and CaBP-D28k (Experiment 4) (P < 0.05). These results suggest that adequate supplementation with 1,25(OH)2D3 (5 µg/kg) can restore broiler growth and bone quality by upregulating the transcription of genes involved in intestinal P and Ca absorption. Additionally, the ERK and p38MAPK signaling pathways are implicated in the modulatory effect of 1,25(OH)2D3 on the absorption of P and Ca in broilers.

Electrical Stimulations Generated by P(VDF-TrFE) Films Enhance Adhesion Forces and Odontogenic Differentiation of Dental Pulp Stem Cells (DPSCs).

Biophysical and biochemical cues of biomaterials can regulate cell behaviors. Dental pulp stem cells (DPSCs) in pulp tissues can differentiate to odontoblast-like cells and secrete reparative dentin to form a barrier to protect the underlying pulp tissues and enable complete pulp healing. Promotion of the odontogenic differentiation of DPSCs is essential for dentin regeneration. The effects of the surface potentials of biomaterials on the adhesion and odontogenic differentiation of DPSCs remain unclear. Here, poly(vinylidene fluoride-trifluoro ethylene) (P(VDF-TrFE)) films with different surface potentials were prepared by the spin-coating technique and the contact poling method. The cytoskeletal organization of DPSCs grown on P(VDF-TrFE) films was studied by immunofluorescence staining. Using atomic force microscopy (AFM), the lateral detachment forces of DPSCs from P(VDF-TrFE) films were quantified. The effects of electrical stimulation generated from P(VDF-TrFE) films on odontogenic differentiation of DPSCs were evaluated in vitro and in vivo. The unpolarized, positively polarized, and negatively polarized films had surface potentials of -52.9, +902.4, and -502.2 mV, respectively. DPSCs on both negatively and positively polarized P(VDF-TrFE) films had larger cell areas and length-to-width ratios than those on the unpolarized films (P < 0.05). During the detachment of DPSCs from P(VDF-TrFE) films, the average magnitudes of the maximum detachment forces were 29.4, 72.1, and 53.9 nN for unpolarized, positively polarized, and negatively polarized groups, respectively (P < 0.05). The polarized films enhanced the mineralization activities and increased the expression levels of the odontogenic-related proteins of DPSCs compared to the unpolarized films (P < 0.05). The extracellular signal-regulated kinase (ERK) signaling pathway was involved in the odontogenic differentiation of DPSCs as induced by surface charge. In vivo, the polarized P(VDF-TrFE) films enhanced adhesion of DPSCs and promoted the odontogenic differentiation of DPSCs by electrical stimulation, demonstrating a potential application of electroactive biomaterials for reparative dentin formation in direct pulp capping.

Downregulation of KLF5 by EBER1 via the ERK signaling pathway in EBV-positive nasopharyngeal carcinoma cells: implications for latent EBV infection.

Nasopharyngeal carcinoma (NPC) carcinogenesis and malignant transformation are intimately associated with Epstein-Barr virus (EBV) infection. A zinc-fingered transcription factor known as Krüppel-like factor 5 (KLF5) has been shown to be aberrantly expressed in a number of cancer types. However, little is known about the regulatory pathways and roles of KLF5 in EBV-positive NPC. Our study found that KLF5 expression was significantly lower in EBV-positive NPC than in EBV-negative NPC. Further investigation revealed that EBER1, which is encoded by EBV, down-regulates KLF5 via the extracellular signal-regulated kinase (ERK) signalling pathway. This down-regulation of KLF5 by EBER1 contributes to maintaining latent EBV infection in NPC. Furthermore, we uncovered the biological roles of KLF5 in NPC cells. Specifically, KLF5 may influence the cell cycle, prevent apoptosis, and encourage cell migration and proliferation - all of which have a generally pro-cancer impact. In conclusion, these findings offer novel strategies for EBV-positive NPC patients' antitumour treatment.

Abstract 1677: The emerging role of the Plasminogen-Apple-Nematode (PAN) domain in cancer therapy

Abstract The Plasminogen-Apple-Nematode (PAN) domain, with a core of four to six cysteine residues, is found in more than 28,000 proteins across 959 genera. However, its role in protein function still needs to be elucidated. Numerous proteins initially characterized the PAN domain, including a well-known master regulator for cancer cell proliferation, HGF (Hepatocyte growth factor). Abnormal regulation of HGF-mediated signaling results in multiple deadly cancers. The binding of HGF to its cell surface receptor, c-MET, triggers signaling pathways, which leads to cancer. Here, we show that mutating four core cysteine residues in the HGF PAN domain reduces c-MET interaction, subsequent c-MET autophosphorylation, and phosphorylation of its downstream targets, perinuclear localization, cellular internalization of HGF and its receptor, c-MET, and c-MET ubiquitination. Furthermore, transcriptional activation of HGF/c-MET signaling-related genes involved in cancer progression, invasion, metastasis, and cell survival was impaired. Thus, targeting the PAN domain of HGF may represent a mechanism for selectively regulating the binding and activation of the c-MET pathway. Additionally, we found this domain in the tumor suppressor gene, MST1 (macrophage stimulating 1), and mutating the domain altered the protein function through protein stability and ubiquitination. In another study, we show that cysteine residues in the vestigial plasminogen-apple-nematode (PAN) domain of NRP1 are necessary for SARS-CoV-2 spike protein internalization. Mutating novel cysteine residues in the PAN altered NRP1 stability and downstream activation of the extracellular signal-regulated kinase (ERK) signaling pathway, impairing its interaction with the spike protein. These results show the diverse critical role of the PAN domain beyond cancer therapy. Citation Format: Kuntal De, Debjani Pal, Wellington Muchero. The emerging role of the Plasminogen-Apple-Nematode (PAN) domain in cancer therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1677.