MAPK Signaling Pathway Research Articles

HIF-1α/LTBP2 axis activate HSCs to promote liver fibrosis by interacting with LOXL1 via the ERK pathway.

Latent Transforming Growth Factor Beta Binding Protein 2 (LTBP2) is a multi-domain exocrine protein located in the extracellular matrix (ECM) and has been implicated in fibrosis across various organs. However, its role in liver fibrosis remains inadequately understood. This study aims to elucidate the function and mechanism of LTBP2 in hepatic stellate cells (HSCs) activation and liver fibrosis. Our findings indicate that LTBP2 expression is positively correlated with liver fibrosis and is significantly elevated in fibrotic liver tissues from both human and murine models. Importantly, AAV6-mediated knockdown of LTBP2 in HSCs markedly alleviates CCl4-induced liver fibrosis by inhibiting the HSCs activation and reducing collagen deposition in mice. Gain-of-function and loss-of-function experiments confirmed that overexpression or knockdown of LTBP2 can enhance or inhibit the activation of HSCs, proliferation, migration and epithelial-mesenchymal transition (EMT) in LX-2 cells. Mechanistically, chromatin immunoprecipitation (ChIP) assays and dual-luciferase reporter gene assays revealed that Hypoxia-inducible Factor 1α (HIF-1α) promotes LTBP2 expression by directly binding to the LTBP2 promoter region. Furthermore, molecular docking and co-immunoprecipitation (Co-IP) experiments demonstrated an interaction between Lysyl Oxidase Like Protein 1 (LOXL1) and LTBP2. Rescue experiments verified that LTBP2 interacts with LOXL1 via the ERK signaling pathway to promote the activation of HSCs and EMT. Our results provide compelling evidence that the HIF-1α/LTBP2 axis facilitates the activation of HSCs and EMT by interacting with LOXL1 through ERK signaling pathway, suggesting that LTBP2 may serve as a potential therapeutic target for liver fibrosis.

Fibroblast growth factor 8 (FGF8) induces mitochondrial remodeling in chondrocytes via ERK/AMPK signaling pathway.

Osteoarthritis (OA) is a disease characterized by articular cartilage degeneration, and its pathogenic mechanisms are associated with mitochondrial homeostasis disorders. Fibroblast growth factor 8 (FGF8) is a multipotent protein ligand which is upregulated in OA cartilage. However, the molecular mechanisms by which FGF8 regulates mitochondria in chondrocytes are not yet fully understood. Here, we treated chondrocytes with FGF8 and detected the effects of FGF8 on mitochondrial morphology in the cytoplasm using transmission electron and confocal laser scanning microscopy. ATP levels were measured to determine the cellular energy status. Western blotting and immunofluorescence staining experiments were employed to detect the fusion-fission proteins mitofusin 1 (MFN1), mitofusin 2 (MFN2), optic atrophy 1 (OPA1), dynamin-related protein 1 (DRP1), mitochondrial fission 1 protein (FIS1), and related signaling pathways. The FGF receptor (FGFR) inhibitor, AZD4547, and the ERK inhibitor, U0126, were used to verify the specific effects of the FGFR and ERK pathways. We found that FGF8 regulated mitochondrial morphology and dynamics in chondrocytes by inducing mitochondrial elongation. While it upregulated fusion proteins MFN1, MFN2, and OPA1, FGF8 downregulated fission proteins DRP1 and FIS1. ERK and AMPK pathways were activated in chondrocytes after FGF8 treatment. In contrast, both AZD4547 and U0126 inhibitors abolished mitochondrial elongation as well as the alteration of fusion-fission proteins induced by FGF8, and U0126 also inhibited the FGF8-triggered activation of AMPK. This study is the first to reveal that FGF8 remodels mitochondria through ERK/AMPK signaling in chondrocytes, offering novel insights into the potential role of FGF8 in OA.

Total flavonoids of litchi seed inhibit breast cancer metastasis by regulating the PI3K/AKT/mTOR and MAPKs signaling pathways

Context Total flavonoids from Litchi chinensis Sonn. (Sapindaceae) seeds (TFLS) effectively attenuate stem cell-like properties in breast cancer cells. However, their pharmacological effects and mechanisms in suppressing breast cancer metastasis remain unclear. Objective This study aimed to elucidate the inhibitory effects and underlying mechanisms of TFLS on breast cancer metastasis. Materials and methods The antiproliferative, migratory, and invasive activities of breast cancer cells following TFLS treatment were evaluated using CCK-8, wound-healing, and transwell assays. The epithelial-mesenchymal transition (EMT) biomarkers were evaluated via Western blot analysis. The anti-metastatic effects of TFLS were further validated in vivo using zebrafish and mouse models. Network pharmacology methodology was utilized to predict potential targets and signaling pathways, which were subsequently corroborated by Western blot. Potential active compounds were identified through molecular docking, and the chemical constituents of TFLS were analyzed and characterized using UPLC-QTOF/MS. Results TFLS suppressed the proliferation of MDA-MB-231 and MDA-MB-468 cells, with IC50 values of 44.47 μg/mL and 37.35 μg/mL at 72 h, respectively. It effectively suppressed breast cancer metastasis in vitro, demonstrated by a marked reduction in cellular motility and invasiveness, alongside the reversal of EMT. Consistent with pathway enrichment analysis, network pharmacology revealed that TFLS reduced the phosphorylation levels of PI3K, AKT, mTOR, JNK, ERK, and p38 in breast cancer cells. Molecular docking identified seven potential active ingredients, and UPLC-MS/MS confirmed the presence of key compounds, including procyanidin A2. Discussion and conclusion TFLS effectively inhibits breast cancer cell proliferation, migration, and invasion in vitro by reversing the EMT phenotype, while suppressing metastasis in vivo. These effects are likely mediated via the attenuation of the PI3K/AKT/mTOR and MAPK signaling pathways.

Moxidectin unravels the role of Hippo-YAP pathway in maintaining immunity of glioblastoma multiforme.

Glioblastoma multiforme (GBM) is a lethal and aggressive cancer with an extremely poor prognosis. Recent preclinical, clinical and genomic studies have highlighted the role of Hippo-Yap pathway in the progression of GBM. In addition, it has been identified that YAP plays a major role in creating immune suppressive tumor microenvironment facilitating drug resistance, recurrence, and metastasis of GBM tumors. Herein, we report that 'moxidectin' an anti-helminthic drug inhibits the proliferation of SF268, SF295, SF188 and CT-2A Luc GBM cells by inducing apoptosis. Immunoblotting and immunofluorescence data shows that moxidectin mediates its effects by inhibiting MEK-ERK pathway, a regulator of Hippo-YAP signaling. Inhibition of MEK-ERK by moxidectin ultimately led to blockade of the nuclear translocation and transcriptional activity of YAP/TAZ-TEAD complex in various GBM cells. Oral administration of 3.5mg/kg moxidectin suppressed the growth of GBM tumors by 90% in an intracranial tumor model. Ex-vivo analysis of excised tumors confirmed the observations made in in vitro studies. Interestingly, moxidectin enhanced antigen presentation in the tumor draining lymph nodes (TDLN) and reduced pro-tumorigenic macrophage population in brain, indicating that it might play a role in modulating the immune response. Chronic moxidectin treatment did not cause any toxicity in mice based on our toxicological evaluation. Moxidectin is an FDA approved drug, findings from our study will promote its clinical investigation as a potential therapeutic agent for GBM patients.

Concurrent Inhibition of the RAS-MAPK Pathway and PIKfyve Is a Therapeutic Strategy for Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by KRAS- and autophagy-dependent growth. Inhibition of the KRAS-RAF-MEK-ERK pathway enhances autophagic flux and dependency, and concurrent treatment with the nonspecific autophagy inhibitor chloroquine (CQ) and ERK-MAPK pathway inhibitors can synergistically block PDAC growth. However, CQ is limited in terms of specificity and potency. To find alternative anti-autophagy strategies, in this study, we performed a CRISPR-Cas9 loss-of-function screen in PDAC cell lines that identified the lipid kinase phosphatidylinositol-3-phosphate 5-kinase (PIKfyve) as a growth-promoting gene. PIKfyve inhibition by the small molecule apilimod resulted in durable growth suppression, with much greater potency than CQ treatment. PIKfyve inhibition caused lysosomal dysfunction, reduced autophagic flux, and led to the accumulation of autophagy-related proteins. Furthermore, PIKfyve inhibition blocked the compensatory increases in autophagic flux associated both with MEK inhibition and with direct RAS inhibition. Accordingly, combined inhibition of PIKfyve and the RAS-MAPK pathway showed robust growth suppression across a panel of KRAS-mutant PDAC models. Growth suppression was due, in part, to potentiated cell-cycle arrest and induction of apoptosis following loss of inhibitor of apoptosis proteins. These findings indicate that concurrent inhibition of RAS and PIKfyve is a synergistic, cytotoxic combination that may represent a therapeutic strategy for PDAC. Significance: PIKfyve inhibition effectively blocks autophagy in multiple models of KRAS-mutant pancreatic cancer and can synergize with inhibitors of members of the RAS-MAPK pathway, providing an effective combination strategy for pancreatic cancer.

α-Fodrin–CENP-E interaction is critical for pancreatic cancer progression and drug response

ABSTRACT α-Fodrin, a known scaffolding protein for cytoskeleton stabilization, performs various functions including cell adhesion, cell motility, DNA repair and apoptosis. Based on our previous results revealing its role in mitosis in glioblastoma, we have examined its effect in pancreatic cancer, which is often linked to mitotic aberrations including aneuploidy and chromosome instability. Here, we show that the expression of α-Fodrin increases in pancreatic adenocarcinoma tissues compared to its normal counterpart, suggesting its tumor promoting role. shRNA-mediated knock-down of α-Fodrin significantly reduces the xenograft growth in immunocompromised mice underscoring the importance of α-Fodrin in tumor progression. CENP-E (centromere-associated protein E) is a motor protein essential for chromosomal alignment and segregation during mitosis. We have found that α-Fodrin interacts with CENP-E to recruit it to the kinetochore and depletion of α-Fodrin has a crucial role in controlling aneuploidy. As these mitotic defects can lead to apoptosis, we have further evaluated the activation of possible upstream pathways. Paclitaxel, a chemotherapeutic agent that stabilizes microtubules, disrupts mitosis and induces apoptosis. We found that Paclitaxel triggered stronger activation of JNK, ERK, and P38 MAPKs, altered BCL2/BAX ratios, cytochrome C release causing increased apoptosis in α-Fodrin knockdown cells compared to cells with wild-type α-Fodrin. This enhanced sensitivity to paclitaxel is consistent with improved survival in pancreatic cancer patients with low α-Fodrin (SPTAN1) and low CENP-E expression compared to poor prognosis with high expressions of both the genes. Taken together, this study provides the molecular mechanism by which α-Fodrin – CENP-E axis regulates pancreatic cancer progression and drug response.

Using transcriptome analysis to investigate the induction of vitellogenesis in female Japanese eels (Anguilla japonica).

Using transcriptome analysis to investigate the induction of vitellogenesis in female Japanese eels (Anguilla japonica).

Epigenetic Biomarkers in Temporomandibular Joint Osteoarthritis: An Emerging Target in Treatment

Osteoarthritis (OA) of the temporomandibular joint (TMJ) is a progressive disease characterized by the progressive destruction of the internal surfaces of the joint. Certain epigenetic biomarkers have been detected in TMJ-OA. We summarized the available evidence on the epigenetic biomarkers in TMJ-OA. There is an increase in the expression of non-coding RNAs related to the degradation of the extracellular matrix, chondrocyte apoptosis, and proinflammatory cytokines, while there is a decrease in the expression of those related to COL2A1, as well as the osteogenic and chondrogenic differentiation of mesenchymal stem cells. Certain methylated genes and histone modifications in TMJ-OA were also identified. In the early stage, DNA methylation was significantly decreased; that is, the expression of inflammation-related genes such as TNF and genes associated with extracellular matrix degradation, such as Adamts, were increased. While in the late stage, there was an increase in the expression of genes associated with the TGF-β and MAPK signaling pathway and angiogenesis-related genes. Although research on the role of epigenetic markers in TMJ-OA is still ongoing, the results here contribute to improving the basis for the identification of accurate diagnostic and prognostic markers and the development of new therapeutic molecules for the prevention and management of TMJ-OA. It also represents a significant advancement in elucidating its pathogenesis.

The transcriptome reveals the potential mechanism of 20E terminating diapause in cotton bollworm, Helicoverpa armigera

BackgroundDiapause is a crucial adaptive strategy employed across numerous insect species, endowing them to survive in unfavorable environments. Helicoverpa armigera, one of the most destructive pests globally, undergoes diapause in the pupa stage, which is essential for its survival during the overwintering period and ultimately determines the following year's population density. 20E is a primary hormone that regulates the process of pupae diapause. However, a comprehensive analysis of the mechanisms by which 20E regulates the initiation and termination of diapause in H. armigera remains lacking.ResultsIn the present study, exogenous 20E was initially administered to diapausing pupae, and the results demonstrated that 20E markedly enhanced the development and eclosion rate of diapausing pupae, indicating that 20E treatment effectively terminated the diapause of H. armigera. Subsequently, RNA-Seq was employed to construct a comprehensive transcriptome map of the 20E-induced termination of diapause. The results demonstrated that there were 2836 differentially expressed genes, including 1315 genes that were upregulated and 1521 genes that were downregulated, in the 20E injection group relative to the control group. KEGG and GO enrichment analysis showed that these genes were associated with various metabolic pathways. Moreover, additional analysis revealed that the majority of the pivotal genes associated with metabolism (including glycolysis/gluconeogenesis, glycerolipid, amino sugar and nucleotide sugar metabolism), cell signaling pathways (such as insulin, Wnt, MAPK signaling pathways), the cell cycle, and stress resistance exhibited altered expression following 20E injection. These findings suggest that 20E exerts its primary influence on metabolic processes, cell signaling pathways, cell cycle, and stress resistance during the termination of diapause.ConclusionsOur study presents a systematic and comprehensive analysis of the genes associated with 20E-induced diapause termination, thereby providing a foundation for elucidating the molecular mechanism of 20E regulating diapause. Furthermore, the findings lend support to the utilization of ecdysone analogs as pesticides in diapause-based pest management.

Deficiency of Fibroblast Growth Factor 2 Promotes Contractile Phenotype of Pericytes in Ascending Thoracic Aortic Aneurysm.

Pericytes exhibit progenitor cell-like qualities and associate with the vasa vasorum- vital microvessels nourishing larger arteries and veins. How pericytes change in human ascending thoracic aortic aneurysm (ATAA) remains unknown. Here we utilized the public single nuclei sequencing data to reveal a contractile phenotype transition of pericytes in human ATAA specimens. Additionally, we found a protective factor, fibroblast growth factor 2 (FGF2), is decreased in aortic adventitia of both male and female ATAA patients and impacting pericytes. We demonstrated that FGF2 maintained pericytes in a less contractile and high angiogenic phenotype via MAPK and PI3K-AKT signaling pathways. These findings suggested the latent engagement of pericytes in ATAA, providing insights that could guide the development of new therapies against aortic disease.

Bone Modelling and Remodelling in Cold Environment

People engaged in various activities in cold environments—such as those living in cold climates, polar workers, cold storage workers, and athletes engaged in winter sports—are frequently affected by cold environments. Therefore, it is of great significance to explore the modelling and remodelling of bones in cold environments. Cold environments can shorten the length of bones, thin the thickness of bones, decrease bone mineral density (BMD), change the biomechanical properties of bones, and lead to bone loss. In addition, cold directly affects the bone microenvironment. Exposure to cold causes spindle-like and fibroblast-like changes in bone marrow mesenchymal stem cells (BMSCs) and decreases their proliferation, and cold exposure promotes the osteogenic differentiation of BMSCs partly through the p38 MAPK pathway. Cold also alters the dendritic differentiation of OBs by reducing the transmembrane glycoprotein E11/podoplanin and damages endothelial cells (ECs) by elevating levels of VEGF, resulting in a reduced blood supply and thus fewer OBs. In addition, cold promotes lipolysis of marrow adipose tissue (MAT), but in combination with exercise, it can promote the differentiation of BMSCs into MAT. Cold environments interfere with angiogenesis and inhibit bone growth by affecting factors such as platelet-derived growth factor type BB (PDGF-BB), slit guidance ligand 3 (SLIT3), Notch, and VEGF. In addition, cold environments may promote bone resorption by activating sympathetic nerves to activate β-adrenergic receptors and regulating leptin secretion, and regulate bone metabolism by activating the p38 MAPK signalling pathway and increasing the synthesis of brown fat, which ultimately inhibit bone formation and enhance bone resorption. In this paper, we describe the effects of cold environments on bones in the locomotor system in terms of bone structure, bone mass, biomechanical properties, and various skeletal cells, bone blood vessels, and bone fat systems in the bone microenvironment.

Transcriptome Analysis Reveals Anti-inflammatory, Antiapoptotic, and Milk Synthesis-Promoting Effects of Lithium Chloride in Bovine Mammary Epithelial Cells.

Lithium, an essential trace element in higher animals, has anti-inflammatory, anti-apoptotic, and nutritional roles. The mechanism by which lithium chloride (LiCl) promotes milk synthesis has been partially elucidated in our previous study; however, potential regulators remain to be identified, and the potential properties of LiCl to inhibit inflammation and apoptosis in bovine mammary epithelial (MAC-T) cells are yet to be clarified. This study aimed to investigate the effects of LiCl on MAC-T cells induced by differentiation using RNA sequencing technology. A total of 237 differentially expressed genes (DEGs) were identified. Through functional annotation using gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis, we identified several genes associated with LiCl function. These genes include inflammation-related genes such as FOSB, C1QTNF1, ANKRD1, DUSP10, ATF3, FAP, and FGF18; apoptosis-related genes such as FAP, FGF18, TMEM170B, and TBX20; milk fat synthesis-related gene FABP9; and milk protein synthesis-related genes TMEM170B, TBX20, FCER1G, and C1QTNF1. Additionally, we found KRT35, a gene that may promote cell proliferation. The aforementioned genes were confirmed via qPCR, and the expression levels of inflammation-related genes pointing to NF-κB (p65) and cellular pro-inflammatory factors TNFα, IL- 1β, IL- 6, and IL- 8 were determined. Following a comprehensive analysis, we hypothesized that in MACT cells, LiCl could inhibit the transcription of inflammatory cytokines genes through inhibition of NF-κB and MAPK signaling pathways to exert anti-inflammatory effects, and increase milk protein and milk fat synthesis through Wnt/β-catenin and mTOR signaling pathways through the differences in gene expression.

A network pharmacology approach and experimental validation to investigate the neuroprotective mechanism of quercetin against alcoholic brain injury via the JNK/P38 MAPK signaling pathway.

A network pharmacology approach and experimental validation to investigate the neuroprotective mechanism of quercetin against alcoholic brain injury via the JNK/P38 MAPK signaling pathway.

Protect Effects of Perilla Seed Extract and Its Active Ingredient Luteolin Against Inflammatory Bowel Disease Model via the PI3K/AKT Signal Pathway In Vivo and In Vitro

The purpose of this study was to investigate the anti-inflammatory effects of Perilla Seed Extract (PSE) and its active ingredient on Inflammatory Bowel Disease (IBD) in vitro and in vivo. Thirty-two C57/BL mice were randomly divided into four groups (n = 8): control group (CON), PBS group, LPS group (LPS 3.5 mg/kg given intraperitoneally [ip] on day 7 of the study only), and PSE group (100 mg/kg orally daily + LPS ip at 3.5 mg/kg on day 7). Mice were euthanized 24 h after LPS administration. MODE-K cells were divided into five groups: control group (CON), LPS group (50 μg/mL LPS for 2 h), and PSE group (low dose, 25 μg/mL PSE + LPS; middle dose, 50 μg/mL PSE + LPS; high dose, 100 μg/mL PSE + LPS). In vivo, compared with the CON group, LPS revealed a significant decrease in the villus length-to-crypt depth ratio (p < 0.01) and goblet cell density per unit area (p < 0.01). Conversely, PSE administration resulted in a significant increase in the villus length-to-crypt depth ratio (p < 0.01) and goblet cell density (p < 0.01). LPS significantly increased the ROS content (p < 0.01), the secretion of inflammatory cytokines of IL-6 (p < 0.01), TNF-α (p < 0.01), and the mRNA expressions of HO-1 (p < 0.01). LPS significantly decreased the mRNA expressions of Occludin (p < 0.01) and Claudin1 (p < 0.01). In contrast, PSE treatment led to a marked decrease in ROS levels (p < 0.01), along with a reduction in the secretion of inflammatory factors IL-6 (p < 0.01) and TNF-α(p < 0.05), as well as the mRNA expressions of HO-1 (p < 0.01). Concurrently, PSE significantly increased the mRNA expressions of Occludin (p < 0.05) and Claudin1 (p < 0.01). In vitro, PSE treatment also significantly reversed LPS-induced inflammation, oxidation and tight junction–related factors. Network pharmacology identified 97 potential targets for PSE in treating IBD, while transcriptomics analysis revealed 342 differentially expressed genes (DEGs). Network pharmacology and transcriptomics analysis indicated that significant pathways included the PI3K-Akt signaling pathway, MAPK signaling pathway, and TNF signaling pathway, of which the PI3K-AKT pathway may represent the primary mechanism. In an in vivo setting, compared with the CON group, LPS led to a significant increase in the protein expression of p-PI3K/PI3K (p < 0.01) and p-AKT1/AKT1 (p < 0.01). Conversely, PSE resulted in a significant decrease in the protein expression of p-PI3K/PI3K (p < 0.01) and p-AKT1/AKT1 (p < 0.01). In vitro, compared with the LPS group, PSE also significantly blocked the protein expression of p-PI3K/PI3K (p < 0.01) and p-AKT1/AKT1 (p < 0.01). The chemical composition of PSE was analyzed using UPLC-MS/MS, which identified six components including luteolin (content 0.41%), rosmarinic acid (content 0.27%), α-linolenic acid (content 1.2%), and oleic acid (content 0.2%). Molecular docking found that luteolin could establish stable binding with eight targets, and luteolin significantly decreased the p-AKT1/AKT1 ratio (p < 0.01) compared to the LPS group in MODE-K cells. In summary, PSE demonstrates efficacy against IBD progression by enhancing intestinal barrier function and inhibiting inflammatory responses and oxidative stress via the PI3K/AKT signaling pathway, and luteolin’s inhibition of AKT1 protein phosphorylation appears to play a particularly crucial role in this therapeutic mechanism.

Integrated m6A RNA methylation and transcriptomic analysis of Apostichopus japonicus under combined high-temperature and hypoxia stress

BackgroundGlobal climate change has significantly increased environmental stress in marine ecosystems, with rising sea surface temperatures and declining dissolved oxygen (DO) levels. These stressors pose critical challenges to aquaculture, particularly for Apostichopus japonicus, an economically significant species in China. A. japonicus is highly sensitive to combined high-temperature and hypoxia stress, which disrupts physiological processes, suppresses immune responses, and increases mortality. While epigenetic mechanisms such as N6-methyladenosine (m6A) RNA modifications are known to regulate stress adaptation, their role under dual stressors in A. japonicus remains poorly understood.ResultsThis study integrates m6A methylation sequencing (MeRIP-seq) and transcriptomic analysis (RNA-seq) to investigate molecular responses in A. japonicus under combined high-temperature (32 °C) and hypoxia (DO = 2 mg/L). Results show that approximately 90% of genes had 1–3 m6A peaks, with single peaks being the most frequent (∼ 60%). Genes with m6A modifications exhibited varying expression levels, with some showing significantly higher expression, suggesting a complex relationship between m6A methylation and stress-responsive gene expression. GO and KEGG enrichment analyses revealed that m6A-modified genes regulate pathways associated with oxidative stress, protein homeostasis, and energy metabolism, such as the PI3K-Akt and MAPK signaling pathways. Key stress-responsive genes, including HSP70, NOX5, and SLC7A11, exhibited dynamic m6A methylation changes, highlighting their roles in redox homeostasis and cellular resilience. Comparative analysis across experimental groups revealed distinct molecular responses to hypoxia, high-temperature stress, and their combination, with combined stress inducing more pronounced changes in m6A methylation and gene expression.ConclusionIn this study, we explored the central regulatory role of m6A RNA methylation in the response of A. japonicus to the dual environmental stress of high-temperature and hypoxia. The findings show that m6A modification regulates the expression of key genes, allowing A. japonicus to effectively adapt to harsh environmental conditions. This study not only provides an important new perspective on the molecular stress recovery mechanism of marine invertebrates in the face of complex environmental stress, but it also provides theoretical support for aquaculture practice, assisting in the development of more stress-resistant aquaculture systems to deal with the severe challenges posed by global climate change.

Discovery of potent MD2 inhibitors by hierarchical virtual screening strategy and bioactivity evaluation.

Discovery of potent MD2 inhibitors by hierarchical virtual screening strategy and bioactivity evaluation.

Recombinant Microneme Proteins MIC1 and MIC4 from Toxoplasma gondii Cause Cytotoxic Effects in the Human Jurkat T-Lymphocyte Cell Line

Toxoplasma gondii is an obligate intracellular parasite that causes toxoplasmosis, a potentially devastating disease to fetuses and immunocompromised individuals. Among its microneme proteins, MIC1 and MIC4 play crucial roles in host-parasite interactions, facilitating adhesion by binding glycans on host cells. Beyond these roles, these lectins have been implicated in modulating immune responses and inducing apoptosis, but their effects on human immune cells remain unclear. Here, we investigated the interaction of recombinant MIC1 (rMIC1) and rMIC4 with Jurkat T lymphocytes, a human immune cell model. Both lectins bound Jurkat cells in a carbohydrate-dependent manner, with rMIC4 showing competitive binding over rMIC1. Importantly, we observed that rMIC1 and rMIC4 reduced Jurkat cell viability in a time- and dose-dependent manner, inducing apoptosis through caspase activation by extrinsic and intrinsic pathways. The apoptosis was driven by reactive oxygen species production via the NADPH oxidase complex and the activation of p38 and JNK MAPK signaling pathways, emphasizing the ability of these lectins to modulate cellular signaling cascades. This study offers insights into the mechanisms involved in MIC1 and MIC4 interactions with immune cells.

Effects of Ficus carica L. polysaccharide on the intestinal immune function and microbiota of broilers

IntroductionFicus carica L. polysaccharides (FLPs) are groups of biologically active compounds extracted from Ficus carica L.MethodsIn this study, we analyzed the structure of FLPs, predicted their immune enhancement pathway, and detected the impact of FLPs on the growth performance, immune function, and intestinal microflora of broiler chickens.ResultsThe results showed that FLPs are comprised of monosaccharides including rhamnose, arabinose, mannose, glucose, and galactose. Feeding with FLPs significantly promoted the growth performance, slaughtering performance, and immune organs index of chickens compared to the control group (p < 0.05). Moreover, the FLP-h and FLP-m groups had increased levels of sIgA, IgG, IL-4, IL-5, IL-12, and IFN-g; improved immunity and barrier function; and a higher percentage of spleen CD4+ and CD8+ T cell differentiation compared to the control group (p < 0.05). Additionally, the FLP-h group had increased levels of various SCFAs, and increased beneficial bacteria such as Firmicutes at the phylum level and Faecalibacterium, Blautia, Phascolarctobacterium, and Alistipes at the genus level. The results of network pharmacology and KEGG pathway prediction indicate that FLPs may change the structure and metabolism of intestinal microbiota by enhancing carbon fixation pathways in prokaryotes, and promote intestinal immune barrier function through the joint action of bisphenol degradation, retinol metabolism, NODlike signaling pathways, toll-like receptor signaling pathways, and the MAPK signaling pathway. DiscussionThese results suggest that FLP-h supplementation effectively promotes growth performance and enhances the intestinal mucosal immune barrier function in chickens.

The Mechanism of a Novel Mitochondrial-Targeted Icaritin Derivative in Regulating Apoptosis of BEL-7402 Cells Based on the SIRT3 and CypD-Mediated ROS/p38 MAPK Signaling Pathway

Tumorigenesis and progression are closely associated with apoptosis and primarily regulated by mitochondria, which are considered major targets for cancer therapy. In this study, twelve novel icaritin (ICT) derivatives were designed and synthesized, four of which were specifically targeted to mitochondria. Biological studies demonstrated that all compounds containing triphenylphosphine (TPP+) exhibited a substantial increase in antitumor activity compared to ICT and control compounds while also exhibiting notable selectivity for tumor cells over normal cells. Among these derivatives, Mito-ICT-4 exhibited the strongest antiproliferative effect, with an IC50 value of 0.73 ± 0.06 μM for BEL-7402 cells, which is 29 times lower than that of ICT, and an IC50 value of 67.11 ± 2.09 μM for HEK293 cells, indicating approximately 33-fold selectivity for tumor cells. High-performance liquid chromatography (HPLC) analysis revealed that Mito-ICT-4 significantly accumulated in the mitochondria of BEL-7402 cells, with the level of accumulation approximately 2.5 times greater than that of ICT. Further investigations demonstrated that upon entering the mitochondria of tumor cells, Mito-ICT-4 downregulated SIRT3 protein expression, disrupted intracellular redox homeostasis, and led to a substantial increase in mitochondrial ROS levels, abnormal CypD-dependent MPTP opening, mitochondrial membrane potential depolarization, and ROS release into the cytoplasm, ultimately triggering ROS-mediated apoptosis in BEL-7402 cells. Transcriptomic analysis identified differentially expressed genes and enriched pathways, highlighting the ROS-mediated p38-MAPK signaling pathway as a key mediator of Mito-ICT-4-induced mitochondria-dependent apoptosis. The effects of Mito-ICT-4 on the expression of key genes (SIRT3, CypD, P-MKK6, P-P38, and DDIT3) were further validated by qRT-PCR and Western blot analysis, with results aligning with transcriptomic data. The novel ICT derivatives synthesized in this study, with mitochondria-targeting functionality, provide a basis for the development of targeted antitumor drugs.

SIRT5 Regulates Lipid Deposition in Goat Preadipocytes via PI3K-Akt and MAPK Signaling Pathways.

Silent Information Regulator 5 (SIRT5) has been established as a crucial regulator of cellular alanylation modification. Furthermore, accumulating evidence suggests that SIRT5 plays a significant regulatory role in key metabolic pathways, including glycolysis, the tricarboxylic acid (TCA) cycle, and fatty acid oxidation, all of which are closely associated with cellular lipid metabolism. Despite these advancements, the specific role of SIRT5 in regulating intramuscular fat (IMF) deposition in goats, as well as the underlying molecular mechanisms, remains largely unexplored. In this study, we cloned the complete coding sequence of the goat SIRT5 gene and, through amino acid sequence alignment, demonstrated its closest phylogenetic relationship with sheep. Additionally, we characterized the higher expression of SIRT5 during the differentiation of goat intramuscular precursor adipocytes. The silencing of SIRT5 by siRNA-mediated knockdown significantly upregulated the expression of lipogenesis-related genes and enhanced lipid deposition in goat intramuscular preadipocytes. Concurrently, SIRT5 deficiency led to the inhibition of cell proliferation and a marked reduction in apoptosis. Interestingly, although overexpression of SIRT5 promoted cell proliferation, it did not significantly alter lipid deposition in goat intramuscular precursor adipocytes. RNA sequencing (RNA-seq) analysis identified a total of 106 differentially expressed genes (DEGs) following SIRT5 silencing in goat preadipocytes, predominantly involved in the Focal adhesion, HIF-1, PI3K-Akt, and MAPK signaling pathways by KEGG pathway enrichment analysis. Notably, we successfully reversed the phenotypic effects observed in SIRT5 knockdown goat precursor adipocytes by inhibiting the PI3K-Akt and MAPK signaling pathways using the AKT inhibitor LY294002 and the p38 MAPK pathway inhibitor PD169316, respectively. In conclusion, our findings demonstrated that SIRT5 may modulate intramuscular fat deposition in goats through PI3k-Akt and MAPK signaling pathways. These results expand the gene regulatory network associated with IMF formation and provide a theoretical foundation for improving meat quality by targeting IMF deposition.