Expression Of Transcription Factors Research Articles

Expression of MAF bZIP transcription factor B protects against ulcerative colitis through the inhibition of the NF-κB pathway.

The aim of this study was to explore whether MAF bZIP transcription factor B (MAFB) might alleviate ulcerative colitis (UC) in dextran sulfate sodium (DSS)-induced mice and LPS-induced IEC-6 cells. UC in vivo and in vitro model was established by using DSS and LPS, respectively. The mice body weight and disease activity index (DAI) score were recorded daily, and colon length was measured. Moreover, the permeability was evaluated utilizing a fluorescein isothiocyanate dextran (FITC-Dextran) probe. Histopathological changes of DSS-induced colitis mice was assessed utilizing H&E staining. Next, qRT-PCR was performed to detect IL-1β, IL-6, TNF-α, and IL-10 level in in vivo and in vitro. Furthermore, the level of MDA, SOD, CAT, and GSH were evaluated in colon tissues. Besides, the expressions of tight junction proteins and NF-κB pathway relative proteins were examined in colitis mice and IEC-6 cells using western blot, immunohistochemistry and immunofluorescence. MAFB level was downregulated in DSS-induced colitis mice. Moreover, the upregulation of MAFB protected mice from DSS-induced colitis by suppressing DSS-induced inflammation, oxidative stress, and intestinal barrier impairment. We also demonstrated that the upregulation of MAFB inactivated NF-κB pathway in DSS-caused colitis mice. Subsequently, we observed that MAFB upregulation could inhibit LPS-caused epithelial barrier impairment and inflammation in IEC-6 cells. Additionally, MAFB overexpression could suppress the activation of NF-κB pathway in IEC-6 cells. The upregulation of MAFB could protect against UC via the suppression of inflammation and the intestinal barrier impairment through inhibiting the NF-κB pathway.

Anti-Inflammatory and Immunoregulatory Effects of Xiaoqinglong Decoction on a Murine Model of Combined Allergic Rhinitis and Asthma Syndrome

Background Xiaoqinglong Decoction (XQLD) is a traditional Chinese medicine formula used for the treatment of allergic rhinitis and asthma, including combined allergic rhinitis and asthma syndrome (CARAS), due to its anti-inflammatory and anti-seizure properties. However, the pharmacological activities and the underlying molecular mechanisms of XQLD remain to be elucidated . Hence, we investigated the effects of XQLD against inflammation in an ovalbumin (OVA)-induced CARAS model in BALB/c mice. Methods BALB/c mice were sensitized by intraperitoneal injection and aerosol inhalation of OVA. XQLD or dexamethasone was administered by oral gavage prior to OVA challenge for 7 consecutive days. Specific airway resistance (sRAW) was evaluated 24 h after the final challenge with OVA. Enzyme-linked immunosorbent assay was used to measure the levels of serum inflammatory factors. The nasal mucosa and lung tissue were examined for general morphology and goblet hyperplasia using hematoxylin and eosin or periodic acid Schiff staining. Flow cytometry was employed to analyze the frequencies of helper T lymphocytes in peripheral blood. Immunohistochemistry was performed to determine the expression of transcription factors in helper T lymphocytes and γδ TCR. Results XQLD significantly ameliorated the symptoms of CARAS model mice, suppressed serum levels of interferon-γ, interleukin (IL)-2, IL-4, IL-5, IL-17, while increasing levels of IL-10, transforming growth factor-β. Epithelium impairment, cilia loss, eosinophil infiltration, and goblet cell metaplasia were significantly reduced in the nasal mucosa and lung tissue sections. XQLD restored the balance of Th1/Th2 and Th17/Treg cell frequency in peripheral blood. Furthermore, XQLD down-modulated the expression of GATA-binding protein 3 (GATA3), retinoic acid receptor-related orphan receptor γt, and γδ T cell receptor (TCR) in the nasal mucosa, along with GATA3 and γδ TCR in the lung tissue. Conclusions XQLD alleviated OVA-induced CARAS in BALB/c mice through its anti-allergic effects and modulation of the immune system.

Coffee pulp improves glucose and lipid metabolism disorder in high-fat diet-induced diabetic mice

BackgroundCoffee berry extracts are anti-lipogenic and lipolytic. This study aims to investigate the effect and mechanism of coffee pulp on high-fat diet (HFD)-induced glucose and lipid metabolism disorder in mice. MethodsThe type 2 diabetes (T2D) mouse model was established by feeding the C57BL/6 J mice with HFD. Mice were administered with coffee pulp diluted in drinking water before or after the establishment of the T2D mouse model. After treatment, the body weight and fasting blood glucose (FBG) of mice were monitored; the intraperitoneal glucose tolerance test (IPGTT) of mice was performed; plasma insulin was determined by ELISA; serum total cholesterol (TC), triglyceride (TG) and liver TG were determined by biochemical analysis; hematoxylin-eosin (H&E) staining was used to evaluate organ histomorphology. Gene expression of key genes in de novo lipogenesis (DNL) in the liver was examined by quantitative reverse transcription PCR (RT-qPCR). ResultsMice that consumed coffee pulp after modeling showed reduced FBG and liver TG, improved IPGTT, and alleviated fatty liver. Consuming coffee pulp before modeling prevented HFD-induced blood glucose and plasma TG increases. Mice consuming coffee pulp also had lower body fat and liver TG compared to the model group. qPCR results showed that the expression of transcription factors (Srebp1, PPARγ) and genes (Fasn, CideA, Plin3, Plin4, Plin5) related to DNL and lipid droplets (LD) formation in the liver of mice consuming coffee pulp were significantly lower than those of the control group. ConclusionsOur study demonstrated that coffee pulp can attenuate HFD-induced disorders of glucose and lipid metabolism, and this effect may be related to the key pathways of lipid synthesis DNL and LD formation pathways in the liver.

Loss of RREB1 reduces adipogenesis and improves insulin sensitivity in mouse and human adipocytes.

There are multiple independent genetic signals at the Ras-responsive element binding protein 1 (RREB1) locus associated with type 2 diabetes risk, fasting glucose, ectopic fat, height, and bone mineral density. We have previously shown that loss of RREB1 in pancreatic beta cells reduces insulin content and impairs islet cell development and function. However, RREB1 is a widely expressed transcription factor and the metabolic impact of RREB1 loss in vivo remains unknown. Here, we show that male and female global heterozygous knockout (Rreb1 +/-) mice have reduced body length, weight, and fat mass on high-fat diet. Rreb1+/- mice have sex- and diet-specific decreases in adipose tissue and adipocyte size; male mice on high-fat diet had larger gonadal adipocytes, while males on standard chow and females on high-fat diet had smaller, more insulin sensitive subcutaneous adipocytes. Mouse and human precursor cells lacking RREB1 have decreased adipogenic gene expression and activated transcription of genes associated with osteoblast differentiation, which was associated with Rreb1 +/- mice having increased bone mineral density in vivo. Finally, human carriers of RREB1 T2D protective alleles have smaller adipocytes, consistent with RREB1 loss-of-function reducing diabetes risk.

Analysis of the interlink between glucose-6-phosphate dehydrogenase (G6PD) and lung cancer through multi-omics databases

Glucose-6-Phosphate Dehydrogenase (G6PD) is a crucial enzyme that executes the pentose phosphate pathway. Due to its critical nodal position in the metabolic network, it is associated with different forms of cancer tumorigeneses and progression. Nonetheless, its functional role and molecular mechanism in lung cancer remain unknown. The present study provides intricate information associated with G6PD and Lung Cancer. Varieties of public datasets were retrieved by us, including UALCAN, TCGA, cBioPortal, and the UCSC Xena browser. The data obtained were used to assess the expression of G6PD, its clinical features, epigenetic regulation, relationship with tumour infiltration, tumour mutation burden, microsatellite instability, tumour microenvironment, immune checkpoint genes, genomic alteration, and patient's overall survival rate. The present study revealed that the G6PD expression was correlated with the clinical features of lung cancer including disease stage, race, sex, age, smoking habits, and lymph node metastasis. Moreover, the expression profile of G6PD also imparts epigenetic changes by modulating the DNA promoter methylation activity. Methylation of promoters changes the expression of various transcription factors, genes leading to an influence on the immune system. These events linked with G6PD-related mutational gene alterations (FAM3A, LAG3, p53, KRAS). The entire circumstance influences the patient's overall survival rate and poor prognosis. Functional investigation using STRING, GO, and KEGG found that G6PD primarily engages in hallmark functions (metabolism, immunological responses, proliferation, apoptosis, p53, HIF-1, FOXO, PI3K-AKT signaling). This work provides a wide knowledge of G6PD's function in lung cancer, as well as a theoretical foundation for possible prognostic therapeutic markers.

Piperlongumine inhibits the early stage of adipogenesis in 3T3-L1 cells

Piperlongumine (PLM), a natural compound isolated from long peppers, has been reported to possess multiple pharmacological roles, including anti-tumor and anti-diabetic. However, the pharmacological role of PLM on adipogenesis is still unknown. In this study, we found that PLM strongly inhibited 3T3-L1 adipocyte differentiation. This inhibition was determined by the accumulation of lipid droplets and intracellular triglycerides. In addition, PLM downregulated both the mRNA and protein expression of adipogenic transcription factors, including CCAAT-enhancer binding proteins β (C/EBPβ), C/EBPα, and peroxisome proliferator-activated receptor γ (PPARγ). Based on the time-course experiment, we found that the inhibitory effect of PLM on adipogenesis was mainly involved in the early stage of adipogenesis. Studying these differential effects could uncover new mechanisms for regulating adipogenesis and new chemicals for treating obesity.

IRF4 Suppresses Osteogenic Differentiation of Periodontal Ligament Stem Cells by Activating IL-18 Signaling Pathway in Periodontitis.

The present study aims to investigate the role of interferon regulatory factor 4 (IRF4) in osteogenic differentiation of periodontal ligament stem cells (PDLSCs) and analyze the underlying signaling of these processes. In this study, IRF4 is upregulated in periodontitis periodontal ligament tissues, as compared to healthy periodontal ligament tissues. IRF4 knockdown increases cell proliferation, decreases levels of tumor necrosis factor-alpha, interleukin-6, and interleukin-8, enhances osteogenic activity, and increases the expression of RUNX family transcription factor 2, Collagen I, and Osteocalcin in PDLSCs. The opposite results are observed in IRF4 overexpressed PDLSCs. Additionally, GSEA shows that IRF4 activates the interleukin-18 (IL-18) signaling pathway. The expressions of IL-18, B-cell translocation gene 2, interleukin-1beta, and caspase-3 are decreased by IRF4 knockdown, while increased by IRF4 overexpression. IL-18 overexpression eliminates the promoting effect of IRF4 knockdown on osteogenic differentiation of PDLSCs. In conclusion, IRF4 suppresses osteogenic differentiation of PDLSCs by activating the IL-18 signaling pathway.

Biocompatibility and expression of transcription factors of a type B gelatin-Extracellular Matrix of Porcin Urinary Blader scaffold.

to evaluate a membrane based on type B gelatin (G) and porcine urinary bladder extracellular matrix (PUB-EM), highlighting the potential effect of the combination evaluated by biocompatibility and regulation of the expression of transcription factors involved in tissue regeneration. G-PUB-EM membranes were prepared at 12.5, 25, and 50% w/v, and evaluated for biocompatibility with Fibroblast. Chemical characterization by FTIR-ATR showed complex spectra during crosslinking process with glutaraldehyde. Physical tests were performed in deionized water and PBS for 48 h. A significant increase in swelling was observed during the first 2 h. Biocompatibility testing (MTS) and evaluation of the expression profile of genes involved in the cell cycle (Cyclin-D1 VEGF, TNF and NF-κ-B) by PCR showed an increase in viability in a PUB-EM content-dependent way, except for 50% PUB-EM membrane which showed cytotoxic effects with a decrease in cell viability below 70%. The membranes showed an increase in the expression of some factors of cell cycle, as well as inflammatory processes that could promote tissue repair. 12.5 and 25% gelatin type B/porcine urinary bladder extracellular matrix (G/PUB-EM) based membranes have potential for tissue regeneration applications. The use of membranes based on type B gelatin and porcine urinary bladder for tissue engineering represents a novel strategy. Biocompatibility and signaling pathways play a primary role in tissue repair and wound recovery. Transcription factors that mediate signaling, cell division and vascularization are part of molecules that intervene in the regenerative potential of cells. These techniques will have a significant impact on tissue repair and regeneration and thus stop depending on tissue donors or other surgical sites from the same patient, as is the case with burn patients.

Molecular and Clinicopathological Correlates of Wild-Type KRAS Expression in Prostate Cancer

Background The clinicopathological significance of KRAS alterations in clinical prostate cancer (PCa) has yet to be comprehensively studied, and the classic KRAS somatic mutations are rare in PCa. Methods The clinico-genomic data of two PCa cohorts were retrieved from the cancer genome databases. KRAS expression-based gene enrichment for cell proliferation, apoptosis, and epithelial-mesenchymal transition /invasion programmes, RAS activation, MAPK and PI3K signalling were sought using gene enrichment analyses, and validated with clinicopathologically relevant tumour biology signatures. Results RAS activation and hallmark tumour biology pathways were enriched in KRAS-high PCa subsets. KRAS expression also demonstrated significant associations with Gleason score and ISUP prognostic grade groups, pathological tumour stage, overall TNM stage, and treatment outcomes, but not with age, pathological node and metastasis statuses. The study further demonstrated that wild-type KRAS expression was deregulated in PCa by a combination of copy number changes, epigenetic/altered transcription factor-expression and microRNA mechanisms. Conclusion The relevance of KRAS expression to clinical PCa biology and therapy outcomes deserves further validation.

Directed differentiation of pancreatic δ cells from human pluripotent stem cells

Dysfunction of pancreatic δ cells contributes to the etiology of diabetes. Despite their important role, human δ cells are scarce, limiting physiological studies and drug discovery targeting δ cells. To date, no directed δ-cell differentiation method has been established. Here, we demonstrate that fibroblast growth factor (FGF) 7 promotes pancreatic endoderm/progenitor differentiation, whereas FGF2 biases cells towards the pancreatic δ-cell lineage via FGF receptor 1. We develop a differentiation method to generate δ cells from human stem cells by combining FGF2 with FGF7, which synergistically directs pancreatic lineage differentiation and modulates the expression of transcription factors and SST activators during endoderm/endocrine precursor induction. These δ cells display mature RNA profiles and fine secretory granules, secrete somatostatin in response to various stimuli, and suppress insulin secretion from in vitro co-cultured β cells and mouse β cells upon transplantation. The generation of human pancreatic δ cells from stem cells in vitro would provide an unprecedented cell source for drug discovery and cell transplantation studies in diabetes.

Up-regulation of IL-1 signaling pathway enhances gene expression of transcription factors (Jun, Junb, Jund, and Fos)

Up-regulation of IL-1 signaling pathway enhances gene expression of transcription factors (Jun, Junb, Jund, and Fos)

A single-cell multimodal view on gene regulatory network inference from transcriptomics and chromatin accessibility data.

Eukaryotic gene regulation is a combinatorial, dynamic, and quantitative process that plays a vital role in development and disease and can be modeled at a systems level in gene regulatory networks (GRNs). The wealth of multi-omics data measured on the same samples and even on the same cells has lifted the field of GRN inference to the next stage. Combinations of (single-cell) transcriptomics and chromatin accessibility allow the prediction of fine-grained regulatory programs that go beyond mere correlation of transcription factor and target gene expression, with enhancer GRNs (eGRNs) modeling molecular interactions between transcription factors, regulatory elements, and target genes. In this review, we highlight the key components for successful (e)GRN inference from (sc)RNA-seq and (sc)ATAC-seq data exemplified by state-of-the-art methods as well as open challenges and future developments. Moreover, we address preprocessing strategies, metacell generation and computational omics pairing, transcription factor binding site detection, and linear and three-dimensional approaches to identify chromatin interactions as well as dynamic and causal eGRN inference. We believe that the integration of transcriptomics together with epigenomics data at a single-cell level is the new standard for mechanistic network inference, and that it can be further advanced with integrating additional omics layers and spatiotemporal data, as well as with shifting the focus towards more quantitative and causal modeling strategies.

Waterlogging‐Induced Changes in ABA, Carbohydrates and CBF6 Modify Freezing Tolerance in Prehardened Festuca pratensis

ABSTRACTChanges in precipitation and snow melt during warmer winters can increase low‐temperature waterlogging. Such conditions may bring about different effects when compared with a single stress trigger, such as low‐temperature or water excess. The effects of waterlogging are clearly related to water temperature, and the consequences of water excess might be less severe, as more oxygen is dissolved in colder water. The effect of waterlogging during cold acclimation (CA) is poorly understood; most experiments concerning water excess are performed at relatively high‐temperatures. In this study, we examined the effect of 3 weeks of waterlogging (approx. 2 cm above the soil level) on CA in Festuca pratensis Huds. (Fp), a cool‐season grass. Measurements were taken before CA (after prehardening, before flooding) and after 3 weeks of CA in waterlogged (treated) and non‐waterlogged (control) plants. The work included: (i) freezing tolerance test (regrowth after freezing), (ii) analysis of abscisic acid (ABA) content in the leaf, (iii) leaf stomatal conductance, (iv) leaf water content, (v) carbohydrates analysis, including fructans, and (vi) transcript levels of selected genes involved in freezing tolerance, ABA signalling and fructan biosynthesis. The aim of the study was to test a hypothesis that low‐temperature waterlogging in Fp enhances freezing tolerance (plant regrowth after freezing) related to increased ABA accumulation, increased C‐repeat‐binding transcription factor expression and/or increased carbohydrate accumulation, including fructans. Two out of four genotypes exhibited enhanced regrowth following freezing due to waterlogging relative to control. Principal component analysis (PCA) revealed a positive correlation between ABA levels and freezing tolerance in both treatments, with a more pronounced effect observed in the waterlogged plants. However, the phytohormone played different roles in these two treatments. In the context of low‐temperature waterlogging, ABA may be involved in the dehydration tolerance response in genotypes suffering from physiological drought, as well as the induction of C‐repeat‐binding transcription factors (CBFs) and sucrose, which may improve freezing tolerance. The increased fructan amount and polymerisation degree due to waterlogging may provide a carbohydrate sink to maintain a high photosynthetic efficiency, but are not directly responsible for freezing tolerance changes. The study indicates that tolerance mechanisms of Fp exposed to low‐temperature waterlogging involve maintaining a high photosynthetic rate, as well as oxidative and dehydration stress tolerance.

ScRNA sequencing technology for PitNET studies.

Pituitary neuroendocrine tumors (PitNETs) are common, most likely benign tumors with complex clinical characteristics related to hormone hypersecretion and/or growing sellar tumor mass. PitNET types are classified according to their expression of specific transcriptional factors (TFs) and hormone secretion levels. Some types show aggressive, invasive, and reoccurrence behavior. Current research is being conducted to understand the molecular mechanisms regulating these high-heterogeneous neoplasms originating from adenohypophysis, and single-cell RNA sequencing (scRNA-seq) technology is now playing an essential role in these studies due to its remarkable resolution at the single-cell level. This review describes recent studies on human PitNETs performed with scRNA-seq technology, highlighting the potential of this approach in revealing these tumor pathologies, behavior, and regulatory mechanisms.

Integrated transcriptomics and metabolomics provides insights into the Nicotiana tabacum response to heat stress.

Heat stress is a prevalent factor that significantly damages crops, especially with the ongoing global warming and increasing frequency of extreme weather events. Tobacco is particularly sensitive to temperature fluctuations, experiencing reduced yield and quality under high temperatures. However, the underlying molecular mechanisms of heat resistance in tobacco remain poorly understood. This study comprehensively analyzed biochemical, transcriptomic, and metabolomic responses to heat stress on the root and shoot of the tobacco cultivar K326 compared to control conditions. Heat stress significantly increased the activities of antioxidant enzymes (CAT, POD, and SOD) and levels of osmotic mediators (soluble sugars, sucrose, and proline) in the shoot. Furthermore, transcriptome analysis identified 13,176 differentially expressed genes (DEGs) in the root (6,129 up-regulated and 7,047 down-regulated) and 12,283 DEGs (6,621 up-regulated and 5,662 down-regulated) in the shoot. The root had 24 enriched KEGG pathways, including phenylpropanoid metabolism, while the shoot had 32 significant pathways, such as galactose metabolism and MAPK signaling. The metabolomic data identified 647 metabolites in the root and 932 in the shoot, with carbohydrates and amino acids being the main categories. The root had 116 differentially abundant metabolites (DAMs) (107 up-regulated and 9 down-regulated), and the shoot contained 256 DAMs (251 up-regulated and 5 down-regulated). Joint transcriptome and metabolome analysis showed that galactose metabolism and starch and sucrose metabolism were co-enriched in both tissues. In contrast, amino sugar and nucleotide sugar metabolism was enriched in the root, and purine metabolism in the shoot. The purine metabolic pathway in the shoot can modulate the expression of MYB transcription factors by influencing ABA synthesis and signaling, thereby controlling the accumulation of HSPs, raffinose, sucrose, and trehalose to enhance heat tolerance. Furthermore, NtMYB78, an MYB transcription factor, enhances tolerance for heat stress in tobacco. This research offers a foundational framework for investigating and implementing heat-resistant genes and metabolic pathways in the root and shoot of tobacco seedlings.

Intravenous BCG induces a more potent airway and lung immune response than intradermal BCG in SIV-infected macaques.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is one of the leading causes of death due to an infectious agent. Coinfection with HIV exacerbates Mtb infection outcomes in people living with HIV (PLWH). Bacillus Calmette-Guérin (BCG), the only approved TB vaccine, is effective in infants, but its efficacy in adolescents and adults is limited. Here, we investigated the immune responses elicited by BCG administered via intravenous (IV) or intradermal (ID) routes in Simian Immunodeficiency Virus (SIV)-infected Mauritian cynomolgus macaques (MCM) without the confounding effects of Mtb challenge. We assessed the impact of vaccination on T cell responses in the airway, blood, and tissues (lung, thoracic lymph nodes, and spleen), as well as the expression of cytokines, cytotoxic molecules, and key transcription factors. Our results showed that IV BCG induces a robust and sustained immune response, including tissue-resident memory T (TRM) cells in lungs, polyfunctional CD4+ and CD8αβ+ T cells expressing multiple cytokines, and CD8αβ+ T cells and NK cells expressing cytotoxic effectors in airways. We also detected higher levels of mycobacteria-specific IgG and IgM in the airways of IV BCG-vaccinated MCM. Although IV BCG vaccination resulted in an influx of TRM cells in lungs of MCM with controlled SIV replication, MCM with high plasma SIV RNA (>105 copies/mL) typically displayed reduced T cell responses, suggesting that uncontrolled SIV or HIV replication would have a detrimental effect on IV BCG-induced protection against Mtb.

Hmga2 knockdown enhances osteogenic differentiation of adipose-derived mesenchymal stem cells and accelerates bone defect healing in mice

To investigate the role of high-mobility group AT-hook 2 (HMGA2) in osteogenic differentiation of adipose-derived mesenchymal stem cells (ADSCs) and the effect of Hmga2 knockdown for promoting bone defect repair. Bioinformatics studies using the GEO database and Rstudio software identified HMGA2 as a key factor in adipogenic-osteogenic differentiation balance of ADSCs. The protein-protein interaction network of HMGA2 in osteogenic differentiation was mapped using String and visualized with Cytoscape to predict the downstream targets of HMGA2. Primary mouse ADSCs (mADSCs) were transfected with Hmga2 siRNA, and the changes in osteogenic differentiation of the cells were evaluated using alkaline phosphatase staining and Alizarin red S staining. The expressions of osteogenic markers Runt-related transcription factor 2 (RUNX2), osteopontin (OPN), and osteocalcein (OCN) in the transfected cells were detected using RT-qPCR and Western blotting. In a mouse model of critical-sized calvarial defects, mADSCs with Hmga2-knockdown were transplanted into the defect, and bone repair was evaluated 6 weeks later using micro-CT scanning and histological staining. GEO database analysis showed that HMGA2 expression was upregulated during adipogenic differentiation of ADSCs. Protein-protein interaction network analysis suggested that the potential HMGA2 targets in osteogenic differentiation of ADSCs included SMAD7, CDH1, CDH2, SNAI1, SMAD9, IGF2BP3, and ALDH1A1. In mADSCs, Hmga2 knockdown significantly upregulated the expressions of RUNX2, OPN, and OCN and increased cellular alkaline phosphatase activity and calcium deposition. In a critical-sized calvarial defect model, transplantation of mADSCs with Hmga2 knockdown significantly promoted new bone formation. HMGA2 is a crucial regulator of osteogenic differentiation in ADSCs, and Hmga2 knockdown significantly promotes osteogenic differentiation of ADSCs and accelerates ADSCs-mediated bone defect repair in mice.

Cytoplasmic binding partners of the Integrator endonuclease INTS11 and its paralog CPSF73 are required for their nuclear function

INTS11 and CPSF73 are metal-dependent endonucleases for Integrator and pre-mRNA 3'-end processing, respectively. Here, we show that the INTS11 binding partner BRAT1/CG7044, a factor important for neuronal fitness, stabilizes INTS11 in the cytoplasm and is required for Integrator function in the nucleus. Loss of BRAT1 in neural organoids leads to transcriptomic disruption and precocious expression of neurogenesis-driving transcription factors. The structures of the human INTS9-INTS11-BRAT1 and Drosophila dIntS11-CG7044 complexes reveal that the conserved C terminus of BRAT1/CG7044 is captured in the active site of INTS11, with a cysteine residue directly coordinating the metal ions. Inspired by these observations, we find that UBE3D is a binding partner for CPSF73, and UBE3D likely also uses a conserved cysteine residue to directly coordinate the active site metal ions. Our studies have revealed binding partners for INTS11 and CPSF73 that behave like cytoplasmic chaperones with a conserved impact on the nuclear functions of these enzymes.

ASM is a therapeutic target in dermatomyositis by regulating the differentiation of naive CD4 + T cells into Th17 and Treg subsets

BackgroundThis study aims to investigate the involvement of acid sphingomyelinase (ASM) in the pathology of dermatomyositis (DM), making it a potential therapeutic target for DM.MethodsPatients with DM and healthy controls (HCs) were included to assess the serum level and activity of ASM, and to explore the associations between ASM and clinical indicators. Subsequently, a myositis mouse model was established using ASM gene knockout and wild-type mice to study the significant role of ASM in the pathology and to assess the treatment effect of amitriptyline, an ASM inhibitor. Additionally, we investigated the potential treatment mechanism by targeting ASM both in vivo and in vitro.ResultsA total of 58 DM patients along with 30 HCs were included. The ASM levels were found to be significantly higher in DM patients compared to HCs, with median (quartile) values of 2.63 (1.80–4.94) ng/mL and 1.64 (1.47–1.96) ng/mL respectively. The activity of ASM in the serum of DM patients was significantly higher than that in HCs. Furthermore, the serum levels of ASM showed correlations with disease activity and muscle enzyme levels. Knockout of ASM or treatment with amitriptyline improved the severity of the disease, rebalanced the CD4 T cell subsets Th17 and Treg, and reduced the production of their secreted cytokines. Subsequent investigations revealed that targeting ASM could regulate the expression of relevant transcription factors and key regulatory proteins.ConclusionASM is involved in the pathology of DM by regulating the differentiation of naive CD4 + T cells and can be a potential treatment target.

YTHDF2 Regulates Advanced Glycation End Products-Induced Melanogenesis through Inhibiting A20 Expression in Human Dermal Fibroblasts.

Fibroblast A20 suppresses advanced glycation end products (AGEs)-induced melanogenesis by inhibiting NLRP3 inflammasome activation. AGEs repress A20 expression and significantly m6A-methylate A20 mRNA in fibroblasts. YTHDF2 is the most studied m6A reader protein and can accelerate degradation of m6A-modified mRNA. Whether YTHDF2 regulates AGEs-induced A20 expression and pigmentation is unknown. In this study, we confirmed that YTHDF2 inversely regulated AGEs-BSA-inhibited A20 expression but facilitated AGEs-BSA-activated NF-κB signaling and NLRP3 inflammasome in fibroblasts via YTHDF2 knockdown and overexpression experiments. Mechanistically, YTHDF2 bound to m6A-modified A20 mRNA induced by AGEs-BSA and increased its degradation. Moreover, fibroblast YTHDF2 robustly promoted AGEs-BSA-induced IL-18 level in coculture supernatants and melanin content, tyrosinase activity, and expression of microphthalmia-associated transcription factor and tyrosinase in melanocytes, which were significantly blocked by IL-18 binding protein. Further, fibroblast YTHDF2 markedly increased AGEs-BSA-induced epidermal melanin level in cocultured ex vivo skin and MAPKs activation in melanocytes. Importantly, upregulated dermal YTHDF2 expression was negatively correlated with dermal A20 level and positively associated with both epidermal melanin and dermal AGEs content in sun-exposed skin and lesions of melasma and solar lentigo. These findings suggest that fibroblast YTHDF2 positively regulates AGEs-induced melanogenesis mainly via A20/ NF-κB /NLRP3 inflammasome/ IL-18 /MAPKs axis in an m6A-dependent manner and functions in photoaging-induced hyperpigmentation skin disorders.