SHP2-Triggered Endothelial Cell Activation Fuels Estradiol-Independent Endometrial Sterile Inflammation.

Sterile inflammation occurs in various chronic diseases due to many nonmicrobe factors. Examples include endometrial hyperplasia (EH), endometriosis, endometrial cancer, and breast cancer, which are all sterile inflammation diseases induced by estrogen imbalances. However, how estrogen-induced sterile inflammation regulates EH remains unclear. Here, a single-cell RNA-Seq is used to show that SHP2 upregulation in endometrial endothelial cells promotes their inflammatory activation and subsequent transendothelial macrophage migration. Independent of the initial estrogen stimulation, IL1ß and TNFα from macrophages then create a feedforward loop that enhances endothelial cell activation and IGF1 secretion. This endothelial cell-macrophage interaction sustains sterile endometrial inflammation and facilitates epithelial cell proliferation, even after estradiol withdrawal. The bulk RNA-Seq results and phosphoproteomic analysis show that endothelial SHP2 mechanistically enhances RIPK1 activity by dephosphorylating RIPK1Tyr380. This event activates downstream activator protein 1 (AP-1) and instigates the inflammation response. Furthermore, targeting SHP2 using SHP099 (an allosteric inhibitor) or endothelial-specific SHP2 deletion alleviates endothelial cell activation, macrophage infiltration, and EH progression in mice. Collectively, the findings demonstrate that SHP2 mediates the transition of endothelial activation from estradiol-driven acute inflammation to macrophage-amplified chronic inflammation. Targeting sterile inflammation mediated by endothelial cell activation is a promising strategy for nonhormonal intervention in estrogen-related diseases.

Knocking down RAD51AP1 enhances chemosensitivity by inhibiting the self-renewal of CD133 positive ovarian cancer stem-like cells.

PURPOSE: This study was designed to investigate the function of RAD51AP1 in the self-renewal and chemosensitivity of CD133 positive (CD133+) ovarian cancer (OC) stem-like cells. METHODS: CD133+ (CD133 positive) OVCAR4 and CD133 negative (CD133-) OVCAR4 cells were separated from OVCAR4 by flow cytometry. Then, the separated CD133+OVCAR4 cells were divided into the following groups: Vector group; RAD51AP1 group; siNC group; si-RAD51AP1 group. Next, sphere-formation assay and colony forming assay were used to evaluate the self-renewal and proliferation ability of cells; western blot to detect the expression of RAD51AP1, transforming growth factor beta 1 (TGF-ß1) and SMAD4 proteins in tissues and cells; qRT-PCR to assess the mRNA levels of sex-determining region Y-box 2 (SOX2), octamer-binding transcription factor 4 (OCT4), NANOG and Kruppel-like factor 4 (KLF4). RESULTS: The performance of CD133+OVCAR4 cells was much better than that of CD133-OVCAR4 cells in sphere-formation assay and colony forming assay. Besides, compared with adjacent group and CD133-OVCAR4 cells, the expression level of RAD51AP1 increased significantly in OC group and CD133+OVCAR4 cells. Moreover, the over-expression of RAD51AP1 promoted the self-renewal and proliferation of CD133+OVCAR4 cells. On the contrary, knocking down the expression level of RAD51AP1 could inhibit the self-renewal and proliferation of CD133+OVCAR4 cells and improve the sensitivity of cells to chemotherapy drugs. CONCLUSION: The findings of this study showed that RAD51AP1 was highly expressed in OC tissue and CD133+OVCAR4 cells, and regulated the self-renewal and chemosensitivity of tumor cells through the TGF-ß1/SMAD4 signaling pathway.

Interpreting the pharmacological mechanisms of Juanbi recipe on rheumatoid arthritis through network pharmacology, molecular docking.

Background: Traditional Chinese medicine (TCM) offers the advantage of effectively relieving rheumatoid arthritis (RA) with minimal side effects. The Juanbi recipe is a commonly utilized TCM treatment for RA, yet its pharmacological mechanism remains unclear. Network pharmacology serves as an effective tool for identifying pharmaceutical ingredients and potential therapeutic targets of TCM, thereby uncovering its mechanisms. This study aimed to identify the core target genes and explore the mechanisms underlying the treatment of RA with the Juanbi recipe. Methods: This study adopted the method of network pharmacology to filter key gene targets of Juanbi recipe in RA treatment. Single-cell ribonucleic acid (RNA) sequencing data was used to screen the key genes to form the core genes of Juanbi recipe in RA treatment. The molecular docking technique was used to verify the core target genes and explore the mechanisms of Juanbi recipe in RA treatment. The RA model of mice was induced by the collagen-induced arthritis and the effect of Juanbi recipe was evaluated by intragastric administrating of extraction of Juanbi recipe. Enzyme linked immunosorbent assay was used to analysis serum inflammatory factors. Hematoxylin and eosin staining was used to evaluate inflammation and immunohistochemical (IHC) staining was used to evaluate core target genes and pathways in synovium of ankle. Results: This study screened out 281 active molecules in Juanbi recipe, found 105 key target genes of Juanbi recipe in RA treatment, and drew an "ingredient - molecule - gene" diagram. Juanbi recipe reduced the levels of serum interleukin (IL)-1 and IL-6, the inflammatory infiltration in synovium, demonstration that Juanbi recipe reduced both systemic and synovial inflammatory response. Single cell RNA sequencing data were used to select six core target genes and six core active molecules of Juanbi recipe in RA treatment. The pathways of Juanbi recipe in RA treatment involved in activator protein-1 (AP-1) and nuclear factor kappa B (NF-κB) pathway. Results of western blot and IHC staining showed that Juanbi recipe decreased the expressions of c-jun and p65, which demonstrated that Juanbi recipe inhibited the expression of AP-1 and NF-κB pathway in RA. Conclusions: The core active molecules of Juanbi recipe could inhibit key factors of AP-1 and NF-κB pathway to inhibit the inflammation, which played a protective role in RA.

Lnc NBAT1 Inhibits the Proliferation and Migration of Liver Cancer Cells Through the miR-21/PDCD4/AP-1 Signaling Axis.

Long non-coding RNAs (Lnc RNAs) are proven to participate in liver cancer (LC) regulation. The regulation of miR-21 by lnc NBAT1 has been studied in other cancers. However, the effect of this regulation on LC and its specific mechanism remains unclear. Lnc NBAT1 and miR-21 expressions in clinical tissues were measured by RT-qPCR. PDCD4, AP-1, p-c-Fos, p-c-Jun, and cyclin D1 expressions were analyzed by Western blot. Overexpression of lnc NBAT1 was studied to explore its influence on malignant behaviors of Bel7402 cells and the development of LC in the xenograft mouse model (XMM). The regulation mechanism of lnc NBAT1 in LC was explored by lnc NBAT1 overexpression, miR-21 mimic treatment, or PDCD4 silencing in Bel7402 cells. Lnc NBAT1 expression was downregulated while miR-21 expression was upregulated in LC tissues and cell lines. In comparison with LX-2 cells, the expressions of PDCD4 and AP-1 were downregulated in Bel7402 cells, while those of p-c-Fos, p-c-Jun, and cyclin D1 were upregulated. Further, lnc NBAT1 was found to localize primarily in the cytoplasm of Bel7402 cells. Overexpression of lnc NBAT1 enhanced cell apoptosis, blocked the cell cycle, suppressed malignant behaviors of Bel7402 cells, and inhibited tumor progression in the XMM. Mechanistically, lnc NBAT1 functioned as a competing endogenous RNA (ceRNA) by binding to the downstream target miR-21 to stabilize the expressions of PDCD4 and AP-1, thereby inhibiting malignant behaviors of Bel7402 cells. Lnc NBAT1 suppressed malignant behaviors of LC cells through the miR-21/PDCD4/AP-1 axis. Lnc NBAT1 might be a promising biomarker for LC treatment.

Exploration of the potential mechanism of aqueous extract of Artemisia capillaris for the treatment of non-alcoholic fatty liver disease based on network pharmacology and experimental verification.

OBJECTIVES: Non-alcoholic fatty liver disease (NAFLD) is a nutritional and metabolic disease with a high prevalence today. Artemisia capillaris has anti-inflammatory, antioxidant, and other effects. However, the mechanism of A. capillaris in treating NAFLD is still poorly understood. METHODS: This study explored the mechanism of A. capillaris in the treatment of NAFLD through network pharmacology and molecular docking, and verified the results through in vivo experiments using a high-fat diet-induced mouse model and in vitro experiments using an oleic acid-induced HepG2 cell model. KEY FINDINGS: Aqueous extract of A. capillaris (AEAC) can reduce blood lipids, reduce liver lipid accumulation and liver inflammation in NAFLD mice, and improve NAFLD. Network pharmacology analysis revealed that 51 drug ingredients in A. capillaris correspond to 370 targets that act on NAFLD. GEO data mining obtained 93 liver differentially expressed genes related to NAFLD. In the UHPLC-MS detection results, 36 components were characterized and molecular docked with JNK. Verified in vitro and in vivo, the results show that JNK and the phosphorylation levels of IL-6, IL-1ß, c-Jun, c-Fos, and CCL2 are key targets and pathways. CONCLUSIONS: This study confirmed that AEAC reduces lipid accumulation and inflammation in the liver of NAFLD mice by inhibiting the JNK/AP-1 pathway.

CRKL Enhances YAP Signaling through Binding and JNK/JUN Pathway Activation in Liver Cancer.

The Hippo pathway transducers yes-associated protein (YAP) and WW-domain containing transcription regulator 1 (WWTR1/TAZ) are key regulators of liver tumorigenesis, promoting tumor formation and progression. Although the first inhibitors are in clinical trials, targeting the relevant upstream regulators of YAP/TAZ activity could prove equally beneficial. To identify regulators of YAP/TAZ activity in hepatocarcinoma (HCC) cells, we carried out a proximity labelling approach (BioID) coupled with mass spectrometry. We verified CRK-like proto-oncogene adaptor protein (CRKL) as a new YAP-exclusive interaction partner. CRKL is highly expressed in HCC patients, and its expression is associated with YAP activity as well as poor survival prognosis. In vitro experiments demonstrated CRKL-dependent cell survival and the loss of YAP binding induced through actin disruption. Moreover, we delineated the activation of the JNK/JUN pathway by CRKL, which promoted YAP transcription. Our data illustrate that CRKL not only promoted YAP activity through its binding but also through the induction of YAP transcription by JNK/JUN activation. This emphasizes the potential use of targeting the JNK/JUN pathway to suppress YAP expression in HCC patients.

The JNK and Hippo pathways control epithelial integrity and prevent tumor initiation by regulating an overlapping transcriptome.

Epithelial organs maintain their integrity and prevent tumor initiation by actively removing defective cells, such as those that have lost apicobasal polarity. Here, we identify how transcription factors of two key signaling pathways-Jun-N-terminal kinase (JNK) and Hippo-regulate epithelial integrity by controlling transcription of an overlapping set of target genes. Targeted DamID experiments reveal that, in proliferating cells of the Drosophila melanogaster eye, the AP-1 transcription factor Jun and the Hippo pathway transcription regulators Yorkie and Scalloped bind to a common suite of target genes that promote organ growth. In defective neoplastic cells, AP-1 transcription factors repress transcription of growth genes together with the C-terminal binding protein (CtBP) co-repressor. If gene repression by AP-1/CtBP fails, neoplastic tumor growth ensues, driven by Yorkie/Scalloped. Thus, AP-1/CtBP eliminates defective cells and prevents tumor initiation by acting in parallel to Yorkie/Scalloped to repress expression of a shared transcriptome. These findings shed new light on the maintenance of epithelial integrity and tumor suppression.

AP-1 contributes to endosomal targeting of ubiquitin ligase RNF13 via a secondary and novel non-canonical binding motif.

Cellular trafficking between organelles is typically assured by short motifs that contact carrier proteins to transport them to their destination. Ubiquitin E3 ligase RING finger protein 13 (RNF13), a regulator of proliferation, apoptosis, and protein trafficking, localizes to endolysosomal compartments through the binding of a dileucine motif to clathrin adaptor protein complex AP-3. Mutations within this motif reduce the ability of RNF13 to interact with AP-3. Here, our study shows the discovery of a glutamine-based motif that resembles a tyrosine-based motif within RNF13's C-terminal region that binds to the clathrin adaptor protein complex AP-1, notably without a functional interaction with AP-3. Using biochemical, molecular, and cellular approaches in HeLa cells, our study demonstrates that a RNF13 dileucine variant uses an AP-1-dependent pathway to be exported from the Golgi towards the endosomal compartment. Overall, this study provides mechanistic insights into the alternate route used by variant of RNF13's dileucine sorting motif.

A non-canonical repressor function of JUN restrains YAP activity and liver cancer growth.

Yes-associated protein (YAP) and its homolog, transcriptional coactivator with PDZ-binding motif (TAZ), are the main transcriptional downstream effectors of the Hippo pathway. Decreased Hippo pathway activity leads to nuclear translocation of YAP/TAZ where they interact with TEAD transcription factors to induce target gene expression. Unrestrained YAP/TAZ activity can lead to excessive growth and tumor formation in a short time, underscoring the evolutionary need for tight control of these two transcriptional coactivators. Here, we report that the AP-1 component JUN acts as specific repressor of YAP/TAZ at joint target sites to decrease YAP/TAZ activity. This function of JUN is independent of its heterodimeric AP-1 partner FOS and the canonical AP-1 function. Since expression of JUN is itself induced by YAP/TAZ, our work identifies a JUN-dependent negative feedback loop that buffers YAP/TAZ activity at joint genomic sites. This negative feedback loop gets disrupted in liver cancer to unlock the full oncogenic potential of YAP/TAZ. Our results thus demonstrate an additional layer of control for the interplay of YAP/TAZ and AP-1.

EWS-FLI1 and Activator Protein-1 (AP-1) Reciprocally Regulate Extracellular-Matrix Proteins in Ewing sarcoma Cells.

Ribonucleotide reductase (RNR) is the rate-limiting enzyme in the synthesis of deoxyribonucleotides and the target of multiple chemotherapy drugs, including gemcitabine. We previously identified that inhibition of RNR in Ewing sarcoma tumors upregulates the expression levels of multiple members of the activator protein-1 (AP-1) transcription factor family, including c-Jun and c-Fos, and downregulates the expression of c-Myc. However, the broader functions and downstream targets of AP-1, which are highly context- and cell-dependent, are unknown in Ewing sarcoma tumors. Consequently, in this work, we used genetically defined models, transcriptome profiling, and gene-set -enrichment analysis to identify that AP-1 and EWS-FLI1, the driver oncogene in most Ewing sarcoma tumors, reciprocally regulate the expression of multiple extracellular-matrix proteins, including fibronectins, integrins, and collagens. AP-1 expression in Ewing sarcoma cells also drives, concurrent with these perturbations in gene and protein expression, changes in cell morphology and phenotype. We also identified that EWS-FLI1 dysregulates the expression of multiple AP-1 proteins, aligning with previous reports demonstrating genetic and physical interactions between EWS-FLI1 and AP-1. Overall, these results provide novel insights into the distinct, EWS-FLI1-dependent features of Ewing sarcoma tumors and identify a novel, reciprocal regulation of extracellular-matrix components by EWS-FLI1 and AP-1.

p-Hydroxy benzaldehyde, a phenolic compound from Nostoc commune, ameliorates DSS-induced colitis against oxidative stress via the Nrf2/HO-1/NQO-1/NF-κB/AP-1 pathway.

BACKGROUND: Ulcerative colitis (UC), a chronic idiopathic inflammatory bowel disease (IBD), presents with limited current drug treatment options. Consequently, the search for safe and effective drug for UC prevention and treatment is imperative. Our prior studies have demonstrated that the phenolic compound p-Hydroxybenzaldehyde (HD) from Nostoc commune, effectively mitigates intestinal inflammation. However, the mechanisms underlying HD's anti-inflammatory effects remain unclear. PURPOSE: This study delved into the pharmacodynamics of HD and its underlying anti-inflammation mechanisms. METHODS: For in vivo experiments, dextran sodium sulfate (DSS)-induced colitis mouse model was established. In vitro inflammation model was established using lipopolysaccharide (LPS)-induced RAW264.7 and bone marrow-derived macrophages (BMDMs). The protective effect of HD against colitis was determined by monitoring clinical symptoms and histological morphology in mice. The levels of inflammatory factors and oxidative stress markers were subsequently analyzed with enzyme-linked immunosorbent assay (ELISA) and biochemical kits. Furthermore, western blotting (WB), immunofluorescence (IF), luciferase reporter gene, drug affinity reaction target stability (DARTS) assay, molecular docking, and molecular dynamics (MD) simulation were used to determine the potential target and molecular mechanism of HD. RESULTS: Our findings indicate that HD significantly alleviated the clinical symptoms and histological morphology of colitis in mice, and curtailed the production of pro-inflammatory cytokines, including TNF-α, IL-6, IFN-γ, COX-2, and iNOS. Furthermore, HD stimulated the production of SOD, CAT, and GSH-px, enhanced total antioxidant capacity (T-AOC), and reduced MDA levels. Mechanically, HD augmented the expression of Nrf2, HO-1, and NQO-1, while concurrently downregulating the phosphorylation of p65, IκBα, c-Jun, and c-Fos. ML385 and siNrf2 largely attenuated the protective effect of HD in enteritis mice and RAW 264.7 cells, as well as the promotion of HO-1 expression levels. ZnPP-mediated HO-1 knockdown reversed HD-induced inhibition of colonic inflammation. Luciferase reporter assay and IF assay confirmed the transcriptional activation of Nrf2 by HD. DARTS analysis, molecular docking, and MD results showed high binding strength, interaction efficiency and remarkable stability between Nrf2 and HD. CONCLUSION: These outcomes extend our previous research results that HD can combat oxidative stress through the Nrf2/HO-1/NQO-1/NF-κB/AP-1 pathways, effectively alleviating colitis, and propose new targets for HD to protect against intestinal barrier damage.

Neuroprotective effect of diosmin against chlorpyrifos-induced brain intoxication was mediated by regulating PPAR-γ and NF-κB/AP-1 signals.

Chlorpyrifos (CPF) is a widely used organophosphate (OP) pesticide. Unfortunately, pesticides are known to cause neuronal intoxication. Diosmin (DS) is an antioxidant, anti-inflammatory, and neuroprotective flavonoid with high efficacy and safety. We plan to investigate the efficacy of DS in treating CPF-induced neurotoxicity, as well as the mechanisms underlying the protective effects. In our study, rats were randomized into 5 groups: control, DS (50 mg/kg), CPF (10 mg/kg), CPF + DS (25 mg/kg), and CPF + DS (50 mg/kg). The results indicated that DS ameliorated neuronal intoxication induced by CPF, evidenced by decreasing Tau, p-Tau, and ß-amyloid. Histological examinations support these findings. DS significantly ameliorated CPF-induced neuronal oxidative injury by decreasing MDA content and elevating GSH, GST, and SOD levels mediated by PPAR-γ upregulation. DS suppressed CPF-induced brain inflammation by decreasing MPO enzymatic activity and TNF-α, IL-1ß, and IL-6 levels mediated by downregulation of NF-κB/AP-1(c-FOS and c-JUN) signal. Of note, DS protective effects were dose dependent. In conclusion, our data suggested that DS was a promising therapeutic strategy for attenuating CPF-induced neuronal intoxication by restoring oxidant-antioxidant balance and inhibiting inflammatory response in brain tissues.

Dynamic regulation of tissue fluidity controls skin repair during wound healing.

During wound healing, different pools of stem cells (SCs) contribute to skin repair. However, how SCs become activated and drive the tissue remodeling essential for skin repair is still poorly understood. Here, by developing a mouse model allowing lineage tracing and basal cell lineage ablation, we monitor SC fate and tissue dynamics during regeneration using confocal and intravital imaging. Analysis of basal cell rearrangements shows dynamic transitions from a solid-like homeostatic state to a fluid-like state allowing tissue remodeling during repair, as predicted by a minimal mathematical modeling of the spatiotemporal dynamics and fate behavior of basal cells. The basal cell layer progressively returns to a solid-like state with re-epithelialization. Bulk, single-cell RNA, and epigenetic profiling of SCs, together with functional experiments, uncover a common regenerative state regulated by the EGFR/AP1 axis activated during tissue fluidization that is essential for skin SC activation and tissue repair.

Two-polarized roles of transcription factor FOSB in lung cancer progression and prognosis: dependent on p53 status.

BACKGROUND: Activator protein-1 (AP-1) represents a transcription factor family that has garnered growing attention for its extensive involvement in tumor biology. However, the roles of the AP-1 family in the evolution of lung cancer remain poorly characterized. FBJ Murine Osteosarcoma Viral Oncogene Homolog B (FOSB), a classic AP-1 family member, was previously reported to play bewilderingly two-polarized roles in non-small cell lung cancer (NSCLC) as an enigmatic double-edged sword, for which the reasons and significance warrant further elucidation. METHODS AND RESULTS: Based on the bioinformatics analysis of a large NSCLC cohort from the TCGA database, our current work found the well-known tumor suppressor gene TP53 served as a key code to decipher the two sides of FOSB - its expression indicated a positive prognosis in NSCLC patients harboring wild-type TP53 while a negative one in those harboring mutant TP53. By constructing a panel of syngeneically derived NSCLC cells expressing p53 in different statuses, the radically opposite prognostic effects of FOSB expression in NSCLC population were validated, with the TP53-R248Q mutation site emerging as particularly meaningful. Transcriptome sequencing showed that FOSB overexpression elicited diversifying transcriptomic landscapes across NSCLC cells with varying genetic backgrounds of TP53 and, combined with the validation by RT-qPCR, PREX1 (TP53-Null), IGFBP5 (TP53-WT), AKR1C3, and ALDH3A1 (TP53-R248Q) were respectively identified as p53-dependent transcriptional targets of FOSB. Subsequently, the heterogenous impacts of FOSB on the tumor biology in NSCLC cells via the above selective transcriptional targets were confirmed in vitro and in vivo. Mechanistic investigations revealed that wild-type or mutant p53 might guide FOSB to recognize and bind to distinct promoter sequences via protein-protein interactions to transcriptionally activate specific target genes, thereby creating disparate influences on the progression and prognosis in NSCLC. CONCLUSIONS: FOSB expression holds promise as a novel prognostic biomarker for NSCLC in combination with a given genetic background of TP53, and the unique interactions between FOSB and p53 may serve as underlying intervention targets for NSCLC.

The WDR11 complex is a receptor for acidic-cluster-containing cargo proteins.

Vesicle trafficking is a fundamental process that allows for the sorting and transport of specific proteins (i.e., "cargoes") to different compartments of eukaryotic cells. Cargo recognition primarily occurs through coats and the associated proteins at the donor membrane. However, it remains unclear whether cargoes can also be selected at other stages of vesicle trafficking to further enhance the fidelity of the process. The WDR11-FAM91A1 complex functions downstream of the clathrin-associated AP-1 complex to facilitate protein transport from endosomes to the TGN. Here, we report the cryo-EM structure of human WDR11-FAM91A1 complex. WDR11 directly and specifically recognizes a subset of acidic clusters, which we term super acidic clusters (SACs). WDR11 complex assembly and its binding to SAC-containing proteins are indispensable for the trafficking of SAC-containing proteins and proper neuronal development in zebrafish. Our studies thus uncover that cargo proteins could be recognized in a sequence-specific manner downstream of a protein coat.

The natural sesquiterpene lactone inulicin suppresses the production of pro-inflammatory mediators via inhibiting NF-κB and AP-1 pathways in LPS-activated macrophages.

OBJECTIVE: Inulicin is a sesquiterpene lactone in Inulae Flos which is clinically used for the treatment of inflammatory diseases, such as cough, sputum production, and vomiting. This study aimed to demonstrate the anti-inflammatory activity and the underlying mechanism of inulicin by using lipopolysaccharide (LPS)-induced in vitro and in vivo models. METHODS: LPS-stimulated RAW264.7 macrophages and mouse peritoneal macrophages (MPMs) were used for evaluating the in vitro anti-inflammatory activity of inulicin, while endotoxemia mice were used for evaluating its in vivo action. Cytokines' levels were determined by ELISA. RT-qPCR and western blot were used for assaying the mRNA and protein levels of target genes. RAW264.7 macrophages transfected with reporter plasmid pNFκB-TA-luc or pAP1-TA-luc were used for assaying the activation of NF-κB or AP-1 signaling. RESULTS: Inulicin significantly inhibited LPS-induced production of NO, IL-6, c-c motif chemokine ligand 2 (CCL2), and IL-1ß in both RAW264.7 cells and MPMs. Mechanism study indicated that it could suppress inducible nitric oxide synthase, IL-6, CCL2, and IL-1ß mRNA levels in LPS-stimulated RAW264.7 cells. Moreover, inulicin inhibited IκBα phosphorylation and prevented the nuclear translocation of p65, thereby inactivating NF-κB signaling. Concurrently, it also inhibited AP-1 signaling by reducing the phosphorylation of C-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK). In endotoxemia mice, a single intraperitoneal administration of inulicin could decrease the production of pro-inflammatory cytokines in serum and peritoneal lavage fluid. CONCLUSIONS: The present study demonstrates that inulicin possesses anti-inflammatory effects in vitro and in vivo, which suggests that inulicin might be a promising candidate for the treatment of inflammatory diseases.

Intestinal epithelium dysfunctions cause IgA deposition in the kidney glomeruli of intestine-specific Ap1m2-deficient mice.

BACKGROUND: Intestinal epithelial cells (IECs) serve as robust barriers against potentially hostile luminal antigens and commensal microbiota. Epithelial barrier dysfunction enhances intestinal permeability, leading to leaky gut syndrome (LGS) associated with autoimmune and chronic inflammatory disorders. However, a causal relationship between LGS and systemic disorders remains unclear. Ap1m2 encodes clathrin adaptor protein complex 1 subunit mu 2, which facilitates polarized protein trafficking toward the basolateral membrane and contributes to the establishment of epithelial barrier functions. METHODS: We generated IEC-specific Ap1m2-deficient (Ap1m2ΔIEC) mice with low intestinal barrier integrity as an LSG model and examined the systemic impact. FINDINGS: Ap1m2ΔIEC mice spontaneously developed IgA nephropathy (IgAN)-like features characterized by the deposition of IgA-IgG immune complexes and complement factors in the kidney glomeruli. Ap1m2 deficiency markedly enhanced aberrantly glycosylated IgA in the serum owing to downregulation and mis-sorting of polymeric immunoglobulin receptors in IECs. Furthermore, Ap1m2 deficiency caused intestinal dysbiosis by attenuating IL-22-STAT3 signaling. Intestinal dysbiosis contributed to the pathogenesis of IgAN because antibiotic treatment reduced aberrantly glycosylated IgA production and renal IgA deposition in Ap1m2ΔIEC mice. INTERPRETATION: IEC barrier dysfunction and subsequent dysbiosis by AP-1B deficiency provoke IgA deposition in the mouse kidney. Our findings provide experimental evidence of a pathological link between LGS and IgAN. FUNDING: AMED, AMED-CREST, JSPS Grants-in-Aid for Scientific Research, JST CREST, Fuji Foundation for Protein Research, and Keio University Program for the Advancement of Next Generation Research Projects.

A multi-omics approach to reveal critical mechanisms of activator protein 1 (AP-1).

The Activator Protein 1 (AP-1) transcription factor complex plays a pivotal role in the regulation of cancer-related genes, influencing cancer cell proliferation, invasion, migration, angiogenesis, and apoptosis. Composed of multiple subunits, AP-1 has diverse roles across different cancer types and environmental contexts, but its specific mechanisms remain unclear. The advent of multi-omics approaches has shed light on a more comprehensive understanding of AP-1's role and mechanism in gene regulation. This review collates recent genome-wide data on AP-1 and provides an overview of its expression, structure, function, and interaction across different diseases. An examination of these findings can illuminate the intricate nature of AP-1 regulation and its significant involvement in the progression of different diseases. Moreover, we discuss the potential use of AP-1 as a target for individual therapy and explore the various challenges associated with such an approach. Ultimately, this review provides valuable insights into the biology of AP-1 and its potential as a therapeutic target for cancer and disease treatments.

Assessing the therapeutic potential of long-chain isomaltooligosaccharides in diabetic and hyperlipidemic rats.

BACKGROUND: The global rise in diabetes prevalence necessitates effective treatments. Rats, mimicking physiological changes seen in Type 2 diabetes, serve as valuable models for studying metabolic disorders. Natural health supplements, especially prebiotics, are gaining interest for improving metabolic health. Isomaltooligosaccharides (IMOs), classified as functional oligosaccharides and prebiotics, have attracted attention due to their beneficial effects on gut microbiota balance and cholesterol reduction. However, commercial IMOs often contain undesirable sugars, leading to the development of long-chain IMOs with enhanced prebiotic properties. METHODS: This study assessed the therapeutic potential of long-chain IMOs derived from Bacillus subtilis strain AP-1 compared to inulin, a widely recognized prebiotic, in addressing hyperglycemia and hyperlipidemia in rats. RESULTS: IMOs treatment effectively reduced blood sugar and triglyceride levels similarly to inulin supplementation. Proteomic analysis revealed changes in hepatic protein profiles, with upregulated pathways including glutathione metabolism, oxidative phosphorylation, and pentose and glucuronate interconversion, while pathways related to fatty acid and amino acid biosynthesis exhibited downregulation. These results suggest promising therapeutic effects of IMOs treatment on diabetes and hyperlipidemia by influencing key metabolic pathways. CONCLUSIONS: Our findings highlight the potential of long-chain IMOs as targeted interventions for metabolic disorders, warranting further investigation into their clinical applicability and mechanisms of action.

The activity of early-life gene regulatory elements is hijacked in aging through pervasive AP-1-linked chromatin opening.

A mechanistic connection between aging and development is largely unexplored. Through profiling age-related chromatin and transcriptional changes across 22 murine cell types, analyzed alongside previous mouse and human organismal maturation datasets, we uncovered a transcription factor binding site (TFBS) signature common to both processes. Early-life candidate cis-regulatory elements (cCREs), progressively losing accessibility during maturation and aging, are enriched for cell-type identity TFBSs. Conversely, cCREs gaining accessibility throughout life have a lower abundance of cell identity TFBSs but elevated activator protein 1 (AP-1) levels. We implicate TF redistribution toward these AP-1 TFBS-rich cCREs, in synergy with mild downregulation of cell identity TFs, as driving early-life cCRE accessibility loss and altering developmental and metabolic gene expression. Such remodeling can be triggered by elevating AP-1 or depleting repressive H3K27me3. We propose that AP-1-linked chromatin opening drives organismal maturation by disrupting cell identity TFBS-rich cCREs, thereby reprogramming transcriptome and cell function, a mechanism hijacked in aging through ongoing chromatin opening.