Cell Signaling Pathways Research Articles

KIF1C and new Huntingtin-interacting protein 1 binding proteins regulate rheumatoid arthritis fibroblast-like synoviocytes' phenotypes.

Huntingtin-interacting protein-1 (HIP1) is a new arthritis severity gene implicated in the regulation of the invasive properties of rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS). These invasive properties of FLS strongly correlate with radiographic and histology damage in patients with RA and rodent models of arthritis. While HIP1 has several intracellular functions, little is known about its binding proteins, and identifying them has the potential to expand our understanding of its role in cell invasion and other disease-contributing phenotypes, and potentially identify new targets for therapy. FLS cell lines from arthritic DA (highly invasive) and from arthritis-protected congenic rats R6 (minimally invasive), which differ in an amino-acid changing HIP1 SNP, were cultured and lysed, and proteins were immunoprecipitated with an anti-HIP1 antibody. Immunoprecipitates were analyzed by mass spectrometry. Differentially detected (bound) proteins were selected for functional experiments using siRNA knockdown in human RA FLS to examine their effect in cell invasiveness, adhesion, cell migration and proliferation, and immunofluorescence microscopy. Proteins detected included a few known HIP1-binding proteins and several new ones. Forty-five proteins differed in levels detected in the DA versus R6 congenic mass spectrometry analyses. Thirty-two of these proteins were knocked down and studied in vitro, with 10 inducing significant changes in RA FLS phenotypes. Specifically, knockdown of five HIP1-binding protein genes (CHMP4BL1, COPE, KIF1C, YWHAG, and YWHAH) significantly decreased FLS invasiveness. Knockdown of KIF1C also reduced RA FLS migration. The binding of four selected proteins to human HIP1 was confirmed. KIF1C colocalized with lamellipodia, and its knockdown prevented RA FLS from developing an elongated morphology with thick linearized actin fibers or forming polarized lamellipodia, all required for cell mobility and invasion. Unlike HIP1, KIF1C knockdown did not affect Rac1 signaling. We have identified new HIP1-binding proteins and demonstrate that 10 of them regulate key FLS phenotypes. These HIP1-binding proteins have the potential to become new therapeutic targets and help better understand the RA FLS pathogenic behavior. KIF1C knockdown recapitulated the morphologic changes previously seen in the absence of HIP1, but did not affect the same cell signaling pathway, suggesting involvement in the regulation of different processes.

Method for Determining Radioresistance of Cancer Cell Lines Based on Cluster Analysis of Clonogenic Cell Survival Data

Background: The outcome of radiation therapy, the duration and quality of life of cancer patients significantly depend on the radiosensitivity (RS) of a cancerous tumor, and the duration of the patient’s relapse-free period is largely determined by the degree of its radioresistance (RR). Today the results of molecular mechanism investigation of cancer radioresistance and the classification of cancer cells according to their radiophenotypes mostly contribute to improving prognosis methods of treatment outcomes and increasing effectiveness of radiation therapy. In this work, we developed a classification method of cancer cells according to their radiosensitivity using machine learning based on the data analysis of clonogenic cell survival under ionizing radiation. Material and methods: The method consists of clustering parameters of experimental dose-effect relationships, which were approximated using the equation of a linear-quadratic (LQ) model, which is used to evaluate RS of cancer cells in radiobiology. The training of the statistical model included published experimental dataset of 96 cancer cell lines, for which parameters a, b and their ratio a/b of the LQ model were determined. Classification of cancer cells according to their radiosensitivity was carried out based on principal component analysis (PCA) in the parameter space (a, a/b), k-means clustering and hierarchical clustering methods. Results: Application of the developed statistical model to a large dataset of cancer cells made it possible to reliably separate radiosensitive and radioresistant (RR) cells into two clusters according to the parameters a and a/b. Application of the model to cancer cells with acquired RR, in which RS was suppressed as a result of exposure to irradiation or hypoxia, allowed tracing the shift of parent cells’ parameters from the RS cluster to the RR cell cluster. To study the genetic mechanisms of radiosensitivity, we performed bioinformatic analysis of the mutation distribution in genes encoding proteins in the cellular signalling pathways of cancer cells, i.e. proliferation, apoptosis, repair of damaged DNA molecules and antioxidant defence cellular system. Conclusion: The developed statistical model of radiophenotypic classification of cancer cells based on their radiosensitivity can be used in the development of radiation therapy treatment plans taking into account radiosensitivity of patient’s tumour. The model may be also helpful in a joint analysis of the phenotypic and genotypic characteristics of cancer cells, aiming at the elucidation of the molecular and genetic mechanisms of radiosensitivity and development of biomarkers of radioresistance.

Effect of Haoqin Qingdan Tang on influenza A virus through the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway

ObjectiveInfluenza, a viral respiratory illness, leads to seasonal epidemics and occasional pandemics. Given the rising resistance and adverse reactions associated with anti-influenza drugs, Traditional Chinese Medicine (TCM) emerges as a promising approach to counteract the influenza virus. Specifically, Haoqin Qingdan Tang (HQQDT), a TCM formula, has been employed as an adjuvant treatment for influenza in China. However, the active compounds and underlying mechanisms of HQQDT remain unknown. AimThe aim of this study was to investigate HQQDT's antiviral and anti-inflammatory activities in both in vivo and in vitro, and further reveal its active ingredients and mechanism. MethodsIn vivo and in vitro experiments were conducted to verify the antiviral and anti-inflammatory activities of HQQDT. Subsequently, the active ingredients and mechanism of HQQDT were explored through combining high performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (HPLC-Q-TOF-MS) analysis and network pharmacology. Finally, the examinations of cell cytokines and signaling pathways aimed to elucidate the predicted mechanisms. ResultsThe results indicated that HQQDT exhibited inhibitory effects on influenza viruses A/PR/8/34 (H1N1), A/HK/1/68 (H3N2), and A/California/4/2009 (H1N1) in vitro. Furthermore, HQQDT enhanced the survival rate of influenza-infected mice, reduced the lung index and lung virus titer, and mitigated lung tissue damage in vivo. The proinflammatory cytokine expression levels upon influenza virus infection in PR8-induced A549 cells or mice were suppressed by HQQDT, including IL-6, IL-1β, CCL2, CCL4, IP-10, interferon β1 (IFN-β1), the interferon regulatory factor 3 (IRF3), and hemagglutinin (HA). Twenty-two active components of HQQDT against influenza were identified using HPLC-Q-TOF-MS analysis. Based on network pharmacological predictions, the JAK/STAT signaling pathway is considered the most relevant for HQQDT's action against influenza. Finally, western blot assays revealed that HQQDT regulated the protein level of the JAK/STAT signaling pathway in PR8-infected A549 cells and lung tissue. ConclusionThese findings verified the antiviral and anti-inflammatory effects of HQQDT through JAK-STAT signaling pathway in influenza infections, laying the foundation for its further development.

Generation of Slco1a4-CreERT2-tdTomato Knock-in Mice for Specific Cerebrovascular Endothelial Cell Targeting.

The cerebrovascular endothelial cells with distinct characteristics line cerebrovascular blood vessels and are the fundamental structure of the blood-brain barrier, which is important for the development and homeostatic maintenance of the central nervous system. Cre-LoxP system-based spatial gene manipulation in mice is critical for investigating the physiological functions of key factors or signaling pathways in cerebrovascular endothelial cells. However, there is a lack of Cre recombinase mouse lines that specifically target cerebrovascular endothelial cells. Here, using a publicly available single-cell RNAseq database, we screened the solute carrier organic anion transporter family member 1a4 (Slco1a4) as a candidate marker of cerebrovascular endothelial cells. Then, we generated an inducible Cre mouse line in which a CreERT2-T2A-tdTomato cassette was placed after the initiation codon ATG of the Slco1a4 locus. We found that tdTomato, which can indicate the endogenous Slco1a4 expression, was expressed in almost all cerebrovascular endothelial cells but not in any other non-endothelial cell types in the brain, including neurons, astrocytes, oligodendrocytes, pericytes, smooth muscle cells, and microglial cells, as well as in other organs. Consistently, when crossing the ROSA26LSL-EYFP Cre reporter mouse, EYFP also specifically labeled almost all cerebrovascular endothelial cells upon tamoxifen induction. Overall, we generated a new inducible Cre line that specifically targets cerebrovascular endothelial cells.

Promotion of neurite outgrowth by 3,5,7,3',4'-pentamethoxyflavone is mediated through ERK signaling pathway in Neuro2a cells.

In this study, the effects of 3,5,7,3',4'-pentamethoxyflavone (KP1), a major bioactive ingredient isolated from the Kaempferia parviflora rhizomes, on a neurite outgrowth in Neuro2a cells and its mechanism have been investigated. KP1 increased concentration-dependently the percentage of neurite-bearing cells. KP1 showed a remarkable capability to elicit neurite outgrowth in Neuro2a cells, as evidenced by morphological alterations and immunostaining using anti-class III β-tubulin and anti-NeuN antibodies. KP1 also displayed a higher neurogenic activity than retinoic acid (RA), a promoter of neurite outgrowth in Neuro2a cells. KP1 treatment caused significant elevation in phosphorylation of extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (p38 MAPK) and glycogen synthase kinase-3β (GSK-3β). However, KP1-triggered neurite outgrowth was markedly inhibited by treatment with the ERK inhibitor U0126, whereas p38 MAPK inhibitor SB203580 and GSK-3β inhibitor SB216763 did not influence KP1-induced neurite outgrowth. These results demonstrate that KP1 elicits neurite outgrowth and triggers cell differentiation of Neuro2a cells through ERK signal pathway.

Fuyuan decoction prevents nasopharyngeal carcinoma metastasis by inhibiting circulating tumor cells/ endothelial cells interplay and enhancing anti-cancer immune response.

Distant metastasis is a major cause of treatment failure in cancer patients and a key challenge to improving cancer care today. We hypothesized that enhancing anti-cancer immune response and inhibiting circulating tumor cells (CTCs) adhesion and transendothelial migration through synergistic multi-target approaches may effectively prevent cancer metastasis. "Fuyuan Decoction" (FYD) is a traditional Chinese medicine compound that is widely used to prevent postoperative metastasis in cancer patients, but its underlying mechanism remains unclear. In this work, we systematically elucidated the underlying molecular mechanism by which FYD prevents cancer metastasis through multi-compound and multi-target synergies in vitro and in vivo. FYD significantly prevented cancer metastasis at non-cytotoxic concentrations by suppressing the adhesion of CTCs to endothelial cells and their subsequent transendothelial migration, as well as enhancing anti-cancer immune response. Mechanistically, FYD interrupts adhesion of CTCs to vascular endothelium by inhibiting TNF-α-induced CAMs expression via regulation of the NF-κB signaling pathway in endothelial cells. FYD inhibits invasion and migration of CTCs by suppressing EMT, PI3K/AKT and FAK signaling pathways. Moreover, FYD enhances the anti-cancer immune response by significantly increasing the population of Tc and NK cells in the peripheral immune system. In addition, the chemical composition of FYD was determined by UPLC-HRMS, and the results indicated that multiple compounds in FYD prevents cancer metastasis through multi-target synergistic treatment. This study provides a modern medical basis for the application of FYD in the prevention of cancer metastasis, and suggesting that multi-drug and multi-target synergistic therapy may be one of the most effective ways to prevent cancer metastasis.

Nobiletin Inhibits Breast Cancer Stem Cell by Regulating the Cell Cycle: A Comprehensive Bioinformatics Analysis and In Vitro Experiments

Inhibiting breast cancer stem cell (BCSC) signaling pathways is a strategic method for successfully treating breast cancer. Nobiletin (NOB) is a compound widely found in orange peel that exhibits a toxic effect on various types of cancer cells, and inhibits the signaling pathways that regulate the properties of BCSCs; however, the effects of NOB on BCSCs remain elusive. The purpose of this study was to determine the target genes of NOB for inhibiting BCSCs using in vitro three-dimensional breast cancer cell culture (mammospheres) and in silico approaches. We combined in vitro experiments to develop mammospheres and conducted cytotoxicity, next-generation sequencing, and bioinformatics analyses, such as gene ontology, the Reactome pathway enrichment, network topology, gene set enrichment analysis, hub genes selection, genetic alterations, prognostic value related to the mRNA expression, and mRNA and protein expression of potential NOB target genes that inhibit BCSCs. Here, we show that NOB inhibited BCSCs in mammospheres from MCF-7 cells. We also identified CDC6, CHEK1, BRCA1, UCHL5, TOP2A, MTMR4, and EXO1 as potential NOB targets inhibiting BCSCs. NOB decreased G0/G1, but increased the G2/M cell population. These findings showed that NOB is a potential therapeutic candidate for BCSCs treatment by regulating cell cycle.

Effect of MEHP on testosterone synthesis via Sirt1/Foxo1/Rab7 signaling pathway inhibition of lipophagy in TM3 cells

Mono-2-ethylhexyl phthalic acid (MEHP) is the most toxic metabolite of the plasticizer di-2-ethylhexyl phthalic acid (DEHP), and studies have shown that MEHP causes serious reproductive effects. However, its exact mechanisms of action remain elusive. In this study, we aimed to investigate the reproductive effects of MEHP and preliminarily explore its underlying molecular mechanisms. We found that TM3 cells gradually secreted less testosterone and intracellular free cholesterol with increasing MEHP exposure. MEHP exposure inhibited lipophagy and the Sirt1/Foxo1/Rab7 signaling pathway in TM3 cells, causing aberrant accumulation of intracellular lipid droplets. Addition of the Sirt1 agonist SRT1720 and Rab7 agonist ML-098 alleviated the inhibition of lipophagy and increased free cholesterol and testosterone contents in TM3 cells. SRT1720 alleviated the inhibitory effect of MEHP on the Sirt1/Foxo1/Rab7 signaling pathway, whereas ML-098 only alleviated the inhibition of Rab7 protein expression by MEHP and had no effect on Sirt1 and Foxo1 protein expression. This suggests that MEHP inhibits lipophagy in TM3 cells by suppressing the Sirt1/Foxo1/Rab7 signaling pathway, ultimately leading to a further decrease in cellular testosterone secretion. This study improves our current understanding of the toxicity and molecular mechanisms of action of MEHP and provides new insights into the reproductive effects of phthalic acid esters.

Tricetin suppresses the cell migration and BMP-6 expression through p38 signaling pathways in human retinal pigment epithelium cells.

Proliferative vitreoretinopathy (PVR) is a visual-threatening disease, which cause from the migration of retinal pigment epithelium (RPE). Tricetin, a family of flavonoids, can inhibit the metastasis of several cancers. Herein, we aim to evaluate the possible effect of tricetin on inhibiting ARPE-19 cells migration. The Boyden chamber assay, wound healing assay, RNA sequencing, and Western blot analysis were applied in our experiment. The results revealed that tricetin inhibited the cell migration abilities of ARPE-19 cells. Moreover, using RNA sequencing technology, we revealed that tricetin repressed bone morphogenetic protein-6 (BMP-6) gene expressions in ARPE-19 cells. Overexpression of BMP-6 resulted in significant restoration of cell migration capabilities of tricetin-treated ARPE-19 cells. Furthermore, tricetin suppressed the phosphorylation of the p38 signaling pathway. Moreover, blocking the p38 pathway also inhibits BMP-6 expression and migration in the ARPE-19 cells. In conclusion, this study revealed that tricetin inhibits the ARPE-19 cell migration mainly via the suppression of BMP-6 expression and p38 signaling pathway.

Alkaloids from Zanthoxylum nitidum and their anti-proliferative activity against A549 cells by regulating the EGFR/AKT/mTOR pathway

Zanthoxylum nitidum is frequently used as a traditional Chinese medicine and food supplement. Our previous study revealed that its constituent compounds were able to inhibit cancer cell proliferation. In our continuous exploration of bioactive compounds in Z. nitidum, we isolated ten alkaloids (1-10), including one new natural compound (1), and nine known alkaloids (2-10), from an ethanolic extract of the whole plant. The chemical structures were elucidated based on a combination of comprehensive NMR and HRESIMS analyses. Compounds 5, 8 and 10 exhibited significant antiproliferative effects against A549 cancer cell lines. We further elucidated the underlying molecular mechanisms of the antiproliferative activity of compound 8 in A549 human lung cancer cells. Compound 8 was found to induce cell cycle arrest in the G0/G1 phase via p53 activation and CDK4/6 suppression. Compound 8 also effectively inhibited cell migration through the modulation of the epithelial-mesenchymal transition (EMT), as indicated by the expression of biomarkers, such as N-cadherin downregulation and E-cadherin upregulation. Compound 8 significantly suppressed the activation of the EGFR/AKT/mTOR signalling pathway in A549 cells. These results indicate that alkaloid 8 from Z. nitidum has potential to be a lead antiproliferative compound in cancer cells.

Dopamine signalling in pancreatic islet cells and role in adaptations to metabolic stress.

Dopamine and related receptors are evidenced in pancreatic endocrine tissue, but the impact on islet β-cell stimulus-secretion as well as (patho)physiological role are unclear. The present study has evaluated islet cell signalling pathways and biological effects of dopamine, as well as alterations of islet dopamine in rodent models of diabetes of different aetiology. The dopamine precursor L-DOPA partially impaired glucose tolerance in mice and attenuated glucose-, exendin-4, and alanine-induced insulin secretion. The latter effect was echoed by the attenuation of glucose-induced [Ca2+]i dynamics and elevation of ATP levels in individual mouse islet cells. L-DOPA significantly decreased β-cell proliferation rates, acting predominantly via the D2 receptor, which was most abundant at the mRNA level. The administration of streptozotocin (STZ) or high-fat diet (HFD) in mice significantly elevated numbers of dopamine-positive islet cells, with HFD also increasing colocalization of dopamine with insulin. At the same time, colocalization of dopamine with glucagon was increased in STZ-treated and pregnant mice, but unaffected by HFD. These findings highlight a role for dopamine receptor signalling in islet cell biology adaptations to various forms of metabolic stress.

A dual fluorescent herpes simplex virus type 1 recombinant reveals divergent outcomes of neuronal infection.

Critical stages of lytic herpes simplex virus type 1 (HSV-1) replication are marked by the sequential expression of immediate early (IE) to early (E), then late (L) viral genes. HSV-1 can also persist in neuronal cells via a non-replicative, transcriptionally repressed infection called latency. The regulation of lytic and latent transcriptional profiles is critical to HSV-1 pathogenesis and persistence. We sought a fluorescence-based approach to observe the outcome of neuronal HSV-1 infection at the single-cell level. To achieve this goal, we constructed and characterized a novel HSV-1 recombinant that enables discrimination between lytic and latent infection. The dual reporter HSV-1 encodes a human cytomegalovirus-immediate early (hCMV-IE) promoter-driven enhanced yellow fluorescent protein (eYFP) to visualize the establishment of infection and an endogenous mCherry-VP26 fusion to report lytic replication. We confirmed that viral gene expression, replication, and spread of infection are not altered by the incorporation of the fluorescent reporters, and fluorescent protein (FP) detection virtuously reports the progression of lytic replication. We demonstrate that the outcome of HSV-1 infection of compartmentalized primary neurons is determined by viral inoculating dose: high-dose axonal inoculation proceeds to lytic replication, whereas low-dose axonal inoculation establishes a latent HSV-1 infection. Interfering with low-dose axonal inoculation via small molecule drugs reports divergent phenotypes of eYFP and mCherry reporter detection, correlating with altered states of viral gene expression. We report that the transcriptional state of neuronal HSV-1 infection is variable in response to changes in the intracellular neuronal environment.IMPORTANCEHerpes simplex virus type 1 (HSV-1) is a prevalent human pathogen that infects approximately 67% of the global human population. HSV-1 invades the peripheral nervous system, where latent HSV-1 infection persists within the host for life. Immunological evasion, viral persistence, and herpetic pathologies are determined by the regulation of HSV-1 gene expression. Studying HSV-1 gene expression during neuronal infection is challenging but essential for the development of antiviral therapeutics and interventions. We used a recombinant HSV-1 to evaluate viral gene expression during infection of primary neurons. Manipulation of cell signaling pathways impacts the establishment and transcriptional state of HSV-1 latency in neurons. The work here provides critical insight into the cellular and viral factors contributing to the establishment of latent HSV-1 infection.

Single-cell RNA sequencing reveals cellular and molecular landscape of fetal cystic hygroma

BackgroundThe molecular mechanism of fetal cystic hygroma (CH) is still unclear, and no study has previously reported the transcriptome changes of single cells in CH. In this study, single-cell transcriptome sequencing (scRNA-seq) was used to investigate the characteristics of cell subsets in the lesion tissues of CH patients.MethodsLymphoid tissue collected from CH patients and control donors for scRNA-seq analysis. Differentially expressed gene enrichment in major cell subpopulations as well as cell-cell communication were analyzed. At the same time, the expression and interactions of important VEGF signaling pathway molecules were analyzed, and potential transcription factors that could bind to KDR (VEGFR2) were predicted.ResultsThe results of scRNA-seq showed that fibroblasts accounted for the largest proportion in the lymphatic lesions of CH patients. There was a significant increase in the proportion of lymphatic endothelial cell subsets between the cases and controls. The VEGF signaling pathway is enriched in lymphatic endothelial cells and participates in the regulation of cell-cell communication between lymphatic endothelial cells and other cells. The key regulatory gene KDR in the VEGF signaling pathway is highly expressed in CH patients and interacts with other differentially expressed EDN1, TAGLN, and CLDN5 Finally, we found that STAT1 could bind to the KDR promoter region, which may play an important role in promoting KDR up-regulation.ConclusionOur comprehensive delineation of the cellular composition in tumor tissues of CH patients using single-cell RNA-sequencing identified the enrichment of lymphatic endothelial cells in CH and highlighted the activation of the VEGF signaling pathway in lymphoid endothelial cells as a potential modulator.Simple summaryThe molecular and cellular pathogenesis of fetal cystic hygroma (CH) remains largely unknown. This study examined the distribution and gene expression signature of each cell subpopulation and the possible role of VEGF signaling in lymphatic endothelial cells in regulating the progression of CH by single-cell transcriptome sequencing. The enrichment of lymphatic endothelial cells in CH and the activation of the VEGF signaling pathway in lymphatic endothelial cells provide some clues to the pathogenesis of CH from the perspective of cell subpopulations.

TIN2-mediated reduction of mitophagy induces RPE senescence under high glucose

The telomere-associated protein TIN2 localizes to both telomeres and mitochondria. Nevertheless, the impact of TIN2 on retinal pigment epithelial (RPE) cells in diabetic retinopathy (DR) remains unclear. This research aims to examine the role of TIN2 in the senescence of RPE and its potential as a therapeutic target. Western blotting and immunofluorescence staining were utilized to identify TIN2 expression and mitophagy. RT-qPCR was employed to identify senescent associated secretory phenotype (SASP) in ARPE-19 cells infected with TIN2 overexpression. To examine mitochondria and the cellular senescence of RPE, TEM, SA-β-gal staining, and cell cycle analysis were used. The impact of TIN2 was examined using OCT and immunohistochemistry in mice. DHE staining and ZO-1 immunofluorescence were applied to detect RPE oxidative stress and tight junctions. Our research revealed that increased mitochondria-localized TIN2 aggravated the cellular senescence of RPE cells both in vivo and in vitro under hyperglycemia. TIN2 overexpression stimulated the mTOR signaling pathway in ARPE-19 cells and exacerbated the inhibition of mitophagy levels under high glucose, which can be remedied through the mTOR inhibitor, rapamycin. Knockdown of TIN2 significantly reduced senescence and mitochondrial oxidative stress in ARPE-19 cells under high glucose and restored retinal thickness and RPE cell tight junctions in DR mice. Our study indicates that increased mitochondria-localized TIN2 induced cellular senescence in RPE via compromised mitophagy and activated mTOR signaling. These results propose that targeting TIN2 could potentially serve as a therapeutic strategy in the treatment of DR.

Trilobatin regulates glucose metabolism by ameliorating oxidative stress and insulin resistance in vivo and in vitro.

Trilobatin, a glycosylated dihydrochalcone, has been reported to have anti-diabetic properties. However, the underlying mechanism remains unexplained. In this investigation, the regulation of trilobatin on glucose metabolism of insulin resistance (IR)-HepG2 cells and streptozocin (STZ)-induced mice and its mechanism were evaluated. Different doses of trilobatin (5, 10 and 20 μM) increased glucose consumption, glycogen content, hexokinase (HK), and pyruvate kinase (PK) activity in IR-HepG2 cells. Among them, the HK and PK activity in IR-HepG2 cells treated with 20 μM trilobatin were 1.84 and 2.05 times than those of the IR-group. The overeating, body and tissue weight, insulin levels, liver damage, and lipid accumulation of STZ-induced mice were improved after feeding with different doses of trilobatin (10, 50, and 100mg/kg/d) for 4 weeks. Compared with STZ-induced mice, fasting blood glucose decreased by 61.11% and fasting insulin (FINS) increased by 48.6% after feeding trilobatin (100mg/kg/d). Meanwhile, data from quantitative real-time polymerase chain reaction (qRT-PCR) revealed trilobatin ameliorated glycogen synthesis via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/glycogen synthase kinase-3β (GSK-3β) signaling pathway in IR-HepG2 cells and in STZ-induced mice. Furthermore, in vitro and in vivo experiments showed that trilobatin ameliorated oxidative stress by regulating the mRNA expression of nuclear erythroid-2 related factor 2 (Nrf2)/kelch-like ECH associated protein-1 (Keap-1) pathway as well as heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase-1 (NQO-1). Our research reveals a novel pharmacological activity of trilobatin: regulating glucose metabolism through PI3K/Akt/GSK-3β and Nrf2/Keap-1 signaling pathways, improving insulin resistance and reducing oxidative stress. Trilobatin can be used as a reliable drug resource for the treatment of glucose metabolism disorders.

Geniposide Attenuates Oxygen-glucose Deprivation/Recovery-induced Retinal Ganglion Cell Injury via Akt/Nrf-2 Signaling Pathway.

Glaucoma is an eye disease. Its pathological process involves retinal ischemia-reperfusion (I/R), which causes irreversible blindness in patients. Geniposide (Gen), a bioactive iridoid glycoside extracted from the fruit of gardenia, exhibits many biological effects, such as anti-oxidative stress, anti-inflammation, anti-apoptosis, anti-endoplasmic reticulum stress, and anti-thrombotic effects. However, its therapeutic potential for the retinal I/R injury remains unclear. This study investigated the protective effect of Gen against I/R injury by inhibiting abnormal reactive oxygen species (ROS) and retinal neuron apoptosis. We used oxygen-glucose deprivation/reoxygenation (OGD/R) to induce R28 cells to mimic the pathological process of I/R in glaucoma. We conducted CCK-8 analysis and TUNEL staining to examine cell proliferation and apoptosis in glaucoma. Western blotting was used to assay the expressions of apoptosis and Akt/Nrf-2 pathway-related proteins. The production of ROS was detected by using the corresponding kit. Cell viability decreased, whereas TUNEL staining-positive cells and ROS production increased after the OGD/R injury. The contents of cleaved caspase-3 and Bax/Bcl-2 increased after the OGD/R injury. Treatment with 200 μM of Gen effectively improved the cell viability and suppressed cell apoptosis and ROS production. In addition, Gen could significantly promote the activation of the Akt/Nrf-2 signaling pathway in R28 cells, which was blocked by the inhibition of Akt/Nrf-2. We in vivo verified the neuroprotective effect of Gen by establishing an acute high intraocular pressure (aHIOP) model and obtained similar results to those of the in vitro experimental results. Hence, it can be suggested that Gen provides neuroprotection against the OGD/R-induced injury of R28 cells by activating the Akt/Nrf-2 signaling pathway, which is beneficial for the clinical treatment of glaucoma.

Wnt signaling in cranial bones as a proponent of TH-induced craniosynostosis.

Craniosynostosis (CS) is the premature fusion of the sutures within the skull during embryonic development. Recently, thyrotoxicosis in pregnant women has been shown to increase the risk of craniosynostosis in the developing fetus, but the specific mechanism relating the accelerated bone development in CS to increased thyroid hormone (TH) is unknown. Different cell signaling pathways, such as Wnt, Ihh, BMP, and IGF-1, have been identified in TH regulated bone development. However, the Wnt pathway has been chosen in this study for its extensive involvement in bone development. It is known that Wnt-signaling increases levels of β-catenin which then drives the transcription of Wnt/β-catenin target genes such as Twist1 and Runx2. When upregulated, these genes have been linked to increased osteoblast differentiation and bone formation. In this study, we aimed to determine the level of Wnt signaling activation, in cranial bones of differing embryonic origins (frontal and parietal bones) from an avian model of thyrotoxicosis. Collected bones were processed for assessing β-catenin protein expression by western blotting and Twist1 and Runx2 gene expression by qRT-PCR. Analysis is currently in progress. We predict that differences will be observed between the parietal and frontal bones as the parietal bones derive from the mesoderm whereas the frontal bones derive from the neural crest.

Mitomycin C and its analog trigger cytotoxicity in MCF-7 and K562 cancer cells through the regulation of RAS and MAPK/ERK pathways

Mitomycin C (MC) is an anti-cancer drug which functions by forming interstrand crosslinks (ICLs) between opposing DNA strands. MC analog, 10-decarbamoyl mitomycin C (DMC), unlike MC, has stronger cytotoxic effects on cancer cells with TP53 mutation. We previously demonstrated that MC/DMC could activate p21WAF1/CIP1 in MCF-7 (TP53-proficient) and K562 (TP53 deficient) cells in a TP53-independent mode. We also found that MC/DMC regulate AKT activation in a TP53-dependent manner and that AKT deactivation is not associated with the activation of p21WAF1/CIP1 in response to MC/DMC treatment. RAS proteins are known players in the upstream mediated signaling of p21WAF1/CIP1 activation that leads to control of cell proliferation and cell death. Thus, this prompted us to investigate the effect of both drugs on the expression of RAS proteins and regulation of the MAPK/ERK signaling pathways in MCF-7 and K562 cancer cells. To accomplish this goal, we performed comparative label free proteomics profiling coupled to bioinformatics/complementary phosphoprotein arrays and Western blot validations of key signaling molecules. The MAPK/ERK pathway exhibited an overall downregulation upon MC/DMC treatment in MCF-7 cells but only DMC exhibited a mild downregulation of that same pathway in TP53 mutant K562 cells. Furthermore, treatment of MCF-7 and K562 cell lines with oligonucleotides containing the interstrand crosslinks (ICLs) formed by MC or DMC shows that both ICLs had a stronger effect on the downregulation of RAS protein expression in mutant TP53 K562 cells. We discuss the implication of this regulation of the MAPK/ERK pathway in relation to cellular TP53 status.

IL-33 regulates adipogenesis via Wnt/β-catenin/PPAR-γ signaling pathway in preadipocytes

Interleukin-33 (IL-33), an emerging cytokine within the IL-1 family, assumes a pivotal function in the control of obesity. However, the specific mechanism of its regulation of obesity formation remains unclear. In this study, we found that the expression level of IL-33 increased in visceral adipose tissue in mice fed with a high-fat diet (HFD) compared with that in mice fed with a normal diet (ND). In vitro, we also found the expression level of IL-33 was upregulated during the adipogenesis of 3T3-L1 cells. Functional test results showed that knockdown of IL-33 in 3T3-L1 cells differentiation could promote the accumulation of lipid droplets, the content of triglyceride and the expression of adipogenic–related genes (i.e. PPAR-γ, C/EBPα, FABP4, LPL, Adipoq and CD36). In contrast, overexpression of IL-33 inhibits adipogenic differentiation. Meanwhile, the above tests were repeated after over-differentiation of 3T3-L1 cells induced by oleic acid, and the results showed that IL-33 played a more significant role in the regulation of adipogenesis. To explore the mechanism, transcriptome sequencing was performed and results showed that IL-33 regulated the PPAR signaling pathway in 3T3-L1 cells. Further, Western blot and confocal microscopy showed that the inhibition of IL-33 could promote PPAR-γ expression by inhibiting the Wnt/β-catenin signal in 3T3-L1 cells. This study demonstrated that IL-33 was an important regulator of preadipocyte differentiation and inhibited adipogenesis by regulating the Wnt/β-catenin/PPAR-γ signaling pathway, which provided a new insight for further research on IL-33 as a new intervention target for metabolic disorders.

Decabromodiphenyl ether exposure reduces dabrafenib sensitivity of papillary thyroid carcinoma harboring BRAFV600E mutation through the EGFR-CRAF-MAPK pathway: An in vitro study

Decabromodiphenyl ether (BDE209) has been demonstrated to be associated with thyroid dysfunction and thyroid carcinoma risk as a widely used brominated flame retardants. Although dabrafenib has been confirmed to be a promising therapeutic agent for papillary thyroid carcinoma (PTC) harboring BRAFV600E mutation, the rapid acquired dabrafenib resistance has brought a great challenge to clinical improvement and the underpinning mechanisms remain poorly defined. By treating PTC-derived and normal follicular epithelial cell lines with BDE209, we assessed its impact on the MAPK pathway's activation and evaluated the resultant effects on cell viability and signaling pathways, utilizing methods such as Western blot, IF staining, and RNA-seq bioinformatic analysis. Our findings reveal that BDE209 exacerbates MAPK activation, undermining dabrafenib's inhibitory effects by triggering the EGFR pathway, thereby highlighting BDE209's potential to diminish the pharmacological efficacy of dabrafenib in treating BRAF-mutated PTC. This research underscores the importance of considering environmental factors like BDE209 exposure in the effective management of thyroid carcinoma treatment strategies.