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Results for “Down-Regulation”

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PubMed2026

Individual differences in brain dynamics across a social cognition network induced by cortico-cerebellar tDCS in adults with autism spectrum disorder (ASD).

Autism spectrum disorder (ASD) is a neurodevelopmental condition with core diagnostic domains of social communication impairments, restricted interests and repetitive behaviors. Idiosyncratic brain organization is a potential hallmark of ASD. Previous transcranial direct current stimulation (tDCS) studies often targeted dorsolateral prefrontal cortex, with changes oin brain dynamics averaged across the cohort. We utilized a magnetoencephalographic (MEG) array to characterize individual differences in brain dynamics induced by cortico-cerebellar tDCS across nodes of a social cognition network. A randomized, sham-controlled, double-blind, within-subject clinical trial was conducted in a cohort of 24 young adults with ASD or high autistic traits. Two separate sessions of computerized social learning activities were combined with verum/sham tDCS, with anodal electrode over right temporoparietal junction (TPJ) and cathode on right deltoid. Following stimulation, theta- and alpha-band activity were evaluated within nodes of a social cognition network: bilateral TPJ, fusiform, medial prefrontal cortex and Crus I/II of cerebellum. Idiosyncratic participant-specific up- and down-regulation of theta- and alpha-band activity occurred across the network. Activity in right Crus I/II, a region inundated by the stimulation current, strongly correlated with the change of activity summed across all cerebral cortical nodes in theta- but not alpha-band. Intrinsic theta-band activity is believed to mediate input/output relationships in cerebellar cortex and to drive synaptic plasticity. These results suggest that theta-band stimulation of cerebellar cortex might be an effective therapy for individuals on the autism spectrum who present with cerebellar hyperactivity.

Humans↗

PubMed2026

Integrating transcriptomics and metabolomics reveals the molecular landscape of sperm maturation driven by regional differentiation in the epididymis of Guizhou-Guiqian semi-fine wool sheep.

Epididymal regionalized differentiation is crucial for sperm maturation. However, little is known about the synergistic remodeling mechanisms of different epididymal segments at the transcriptional and metabolic levels during sexual maturation in ruminants (especially sheep). We investigated the caput, corpus, and cauda epididymidis of pre-pubertal (2-month-old) and post-pubertal (7-month-old) Guizhou-Guiqian semi-fine wool sheep using histology, RNA sequencing, and metabolomics. Post-pubertal tissues exhibited increased luminal diameters, cilia lengths, and abundant cauda spermatozoa. Transcriptomic analysis revealed increasing differentially expressed genes (DEGs) along the caput-corpus-cauda axis (4642, 6103, and 7698 DEGs, respectively). Metabolomics detected 786 unique differentially accumulated metabolites (DAMs). Region-specific analysis showed that in the caput, up-regulated pathways (fructose/mannose metabolism; HK2, ALDOA, HKDC1) provide energy and substrates for initial sperm motility. In the corpus, down-regulated genes associated with extracellular matrix and tight junctions suggested epithelial barrier remodeling to establish an immune-tolerant microenvironment. The cauda specifically up-regulated the pentose phosphate pathway (FBP1, GPI) and glutathione metabolism, maintaining redox homeostasis for long-term sperm storage. Additionally, glycerophospholipid metabolism was enriched across all segments, where PEMT, AGPAT5, and LCAT likely regulate sperm plasma membrane fluidity. In conclusion, during sexual maturation, the caput drives energy metabolism and glycosylation, the corpus establishes immune tolerance, and the cauda maintains antioxidant homeostasis. The glycerophospholipid network throughout the across all epididymal segments synergistically remodels sperm membrane. This study reveals the underlying multi-omics regulatory mechanisms of epididymal functional differentiation, providing a theoretical basis for elucidating the molecular mechanisms of sperm maturation in this breed and for the molecular breeding of early reproductive performance in rams.

Animals↗

PubMed2026

Maternal immune activation disrupts epigenomic and functional maturation of cortical excitatory neurons.

Elevated levels of maternal pro-inflammatory cytokines following severe infection during gestation can disrupt offspring neural development and increase the risk of neurodevelopmental disorders. The viral mimetic Poly(I:C) reproduces the effects of gestational influenza exposure, leading to behavioral outcomes that recapitulate neurodevelopmental disorder phenotypes. Although Poly(I:C)-induced maternal immune activation (PIC-MIA) alters the epigenome, behavior and cognition of offspring in adulthood, it remains unclear when these changes occur and how MIA influences the epigenomic regulatory programming across the transition from embryonic development to the mature brain. Here, we examined the effects of PIC-MIA on the epigenomic maturation of the frontal cortex, focusing on excitatory neuron-specific DNA methylation and transcriptomic dynamics throughout perinatal development. Mid-gestation PIC-MIA disrupted development of the excitatory neuron transcriptome, with the largest alterations observed at birth. PIC-MIA altered the development of the mature DNA methylation program of excitatory neurons at thousands of genomic regulatory regions that normally gain or lose methylation during development. Transcription factor binding site analyses of these differentially methylated regions revealed a significant enrichment of Tbr1 motifs within hyper-methylated deep-layer neuron-specific regions at birth. Notably, transcriptional targets of Tbr1 were down-regulated at birth despite up-regulation of Tbr1 transcription, suggesting PIC-MIA uncouples Tbr1 expression from its regulatory function in deep-layer neurons. Electrophysiological recordings of intrinsic and firing properties further confirmed a lasting disruption in deep-layer neuronal activity. Our results suggest that mid-gestation MIA may alter the development of deep-layer neurons through an epigenomic blockade of Tbr1 function, thereby perturbing normal cortical circuit formation.

Journal Article↗

PubMed2026

Proteomic profiling reveals that DPP4 overexpression increases cell adhesion, inhibits cell migration, and restores androgen sensitivity in prostate cancer.

Dipeptidyl peptidase-4 (DPP4), a serine protease with both enzymatic and non-enzymatic roles, has emerged as a context-dependent modulator of tumor progression. In the present study, we investigated the expression and function of DPP4 in androgen-sensitive and castration-resistant prostate cancer (CRPC) models. Proteomic analysis of androgen-resistant prostate cells overexpressing DPP4 identified the involvement of the cellular adhesion molecules pathway. In prostate cells, lentiviral-mediated DPP4 overexpression restored androgen receptor signaling, inhibited epithelial-to-mesenchymal transition, and reduced cell migration, whereas DPP4 silencing produced the opposite effects. We demonstrate that DPP4 expression is down-regulated in CRPC cells and that treatment with capsaicin (CAP), a bioactive compound derived from red peppers, restores DPP4 expression. Moreover, DPP4 restoration by CAP suppresses prostate tumorigenesis in the TRAMP mice in vivo model of prostate cancer. Our results suggest that DPP4 could be a new target for CRPC.

Male↗

PubMed2026

Phase 3 Trial of Oral Infigratinib in Children with Achondroplasia.

BACKGROUND: Achondroplasia is a genetic skeletal condition caused by FGFR3 pathogenic variants. Infigratinib, an oral FGFR1-3 tyrosine kinase inhibitor, down-regulates key pathways in the pathogenesis of achondroplasia. METHODS: In this phase 3, multicenter, double-blind, placebo-controlled trial, we randomly assigned children with achondroplasia (3 to 17 years of age) in a 2:1 ratio to receive infigratinib (at a dose of 0.25 mg per kilogram of body weight) or placebo once daily for 52 weeks. The primary end point was the change from baseline in the annualized height velocity in the infigratinib group as compared with the placebo group at week 52. Key secondary end points were the change from baseline in the height z score and in the upper-to-lower body segment ratio at week 52. The primary analysis evaluated the treatment effect at week 52 in the full analysis population, with missing data handled with a prespecified imputation approach. RESULTS: In all, 114 patients underwent randomization: 75 patients to receive infigratinib (with 1 withdrawal before treatment) and 39 patients to receive placebo. The difference between infigratinib and placebo in the least-squares mean change from baseline to week 52 was 1.74 cm per year (95% confidence interval [CI], 1.31 to 2.17; P<0.001) for the annualized height velocity, 0.32 (96% CI, 0.23 to 0.41; P<0.001) for the height z score, and -0.02 (96% CI, -0.06 to 0.01) for the upper-to-lower body segment ratio. Adverse events occurred in 71 of 74 patients (96%) in the infigratinib group and in 37 of 39 patients (95%) in the placebo group; serious adverse events occurred in 4 of 74 patients (5%) and 1 of 39 patients (3%), respectively. No serious adverse events or adverse events leading to treatment discontinuation were considered by the investigator to be related to infigratinib or placebo. CONCLUSIONS: In children with achondroplasia, treatment with once-daily oral infigratinib for 52 weeks resulted in a significantly greater increase from baseline in the annualized height velocity than placebo. (Funded by BridgeBio Pharma; PROPEL 3 ClinicalTrials.gov number, NCT06164951; EudraCT number, 2023-506130-67.).

Adolescent↗

PubMed2025

Amylin inhibits gastric cancer progression by targeting CCN1 and affecting the PI3K/AKT signalling pathway.

METHODS: This study used a combination of in vitro and in vivo experiments to investigate the role of amylin in the progression of GC. The expression of amylin in GC and its clinical correlation were evaluated using 38 pairs of GC and healthy human clinical samples. In vitro studies, human GC cell lines were treated with amylin to evaluate the effects of amylin on the proliferation, apoptosis and migration of GC cells. In in vivo studies, xenograft mouse models were established by subcutaneous injection of GC cells into nude mice, followed by treatment with amylin to assess tumor growth. Finally, Next-Generation Sequencing Technology (RNA-seq) was used to explore the potential mechanism of amylin on GC. RESULTS: We found that amylin expression was reduced in GC compared to adjacent normal gastric tissues and that elevated amylin expression was negatively correlated with adverse pathological factors (p < 0.05). Additionally, we demonstrated that amylin impeded the growth, invasion, migration, and colony formation of GC cells and suppressed the epithelial-to-mesenchymal transformation of these cells (p < 0.05). Tumour xenograft model experiments confirmed the tumour-suppressive effect of amylin in subcutaneous tumours in nude mice (p < 0.05). Transcriptome sequencing (RNA-seq) revealed that amylin significantly down-regulated CCN1 gene expression in GC cells (p < 0.001). Further intervention targeting CCN1 verified its significance as a target of amylin's anti-carcinogenic function in GC. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that amylin exerted its oncogenic effects by inhibiting the PI3K/Akt signalling pathway (p < 0.05). CONCLUSIONS: Our findings demonstrate that amylin plays a crucial role in suppressing gastric cancer progression by targeting CCN1 and inhibiting the PI3K/Akt signalling pathway. These results suggest that amylin could serve as a potential therapeutic agent for GC treatment.

Humans↗

PubMed2026

Plasma proteome profiling identifies XPNPEP3 as a novel biomarker associated with metabolic dysfunction-associated steatotic liver disease in patients with type 2 diabetes mellitus.

OBJECTIVE: To identify plasma protein differences between type 2 diabetes mellitus (T2DM) patients with and without metabolic dysfunction-associated steatotic liver disease (MASLD), and to evaluate the diagnostic potential of X-prolyl aminopeptidase 3 (XPNPEP3) for identifying MASLD in T2DM patients. METHODS: Twenty T2DM inpatients were categorized into groups with and without MASLD and their plasma samples were analyzed using data-independent acquisition mass spectrometry, followed by bioinformatics analysis to identify differentially expressed proteins. The cohort was then expanded to 84 patients, and plasma XPNPEP3 levels were validated by enzyme-linked immunosorbent assay. Correlation between XPNPEP3 and clinical indicators were evaluated, and diagnostic performance was determined via receiver operating characteristic (ROC) analysis. Immunohistochemistry was employed to compare hepatic XPNPEP3 expression between the two groups. RESULTS: Proteomic analysis identified 176 differentially expressed proteins, with XPNPEP3 exhibiting the most significant down-regulation by fold change. In the validation cohort, plasma XPNPEP3 was significantly lower in T2DM+MASLD versus T2DM alone. XPNPEP3 levels were negatively correlated with diabetes duration, liver function markers, and triglyceride levels, and was identified as an independent factor inversely associated with MASLD in T2DM.ROC analysis demonstrated strong diagnostic performance for XPNPEP3, further enhanced when combined with BMI and diabetes duration.  Immunohistochemistry confirmed reduced hepatic XPNPEP3 expression in T2DM+MASLD patients. CONCLUSIONS: Lower plasma XPNPEP3 is independently associated with MASLD in T2DM patients and demonstrates strong diagnostic potential, positioning XPNPEP3 as a promising biomarker for diagnosing MASLD in T2DM patients and a novel target for non-invasive diagnostic tool development.

Humans↗

PubMed2026

An XRE-type regulator in Streptococcus mutans plays an important role in brpA expression and oxidative stress tolerance response.

This study used a functional genomics approach to explore the role of a xenobiotic response element (XRE)-type regulator (SMU.405c) in Streptococcus mutans physiology, including the expression of biofilm regulatory protein BrpA. Results showed that deletional mutation of xre significantly reduced the ability of the deficient mutant to grow in the presence of methyl viologen, a commonly used oxidative stressor (P < 0.001). When challenged in a hydrogen peroxide killing assay, the survival rate of the ∆xre mutant was >2-log less than the parent strain after 60 min (P < 0.001). Luciferase reporter fusion assays showed that xre deficiency had no significant effect on luciferase expression when it was under the control of the intact brpA promoter, but the reporter activity increased by >6-fold (P < 0.001) when the reporter gene was fused to a brpA promoter derivative with deletion of a putative XRE-binding box. Electrophoretic mobility shift assay (EMSA) showed that recombinant XRE interacted with the brpA promoter, resulting in an electrophoretic shift of the promoter probes. In vitro transcription assay also showed that inclusion of XRE caused transcription to fall off, significantly reducing full-length brpA transcripts. RNA-seq analysis revealed that deficiency of XRE led to altered expression of >102 genes by >2-fold (P < 0.05), including 28 with increased expression, and 74 with decreased expression. Among the down-regulated were genes for DNA repair and oxidative stress tolerance response. These results suggest that XRE (SMU.405c) in S. mutans plays an important role in brpA expression and oxidative stress tolerance response.IMPORTANCEStreptococcus mutans, a keystone pathogen in human dental caries, primarily lives in the highly diverse microbiota on tooth surfaces, where the conditions are often harsh and fluctuate frequently. Locus SMU.405c was annotated to encode a xenobiotic response element (XRE)-like transcriptional regulator, but no information is available concerning the role of this protein in S. mutans pathophysiology. This study used a functional genomics approach along with molecular and transcriptomic analysis to characterize a deletional xre mutant, and the results showed that xre deficiency in S. mutans resulted in weakened oxidative stress tolerance response and alterations in transcription of >102 genes, including those known to play an important role in cell envelope biogenesis and stress tolerance response. Reporter fusion assay, electrophoretic mobility shift assay (EMSA), and in vitro transcription further demonstrated that the XRE-like regulator encoded by SMU.405c is a repressor of brpA expression and plays an important role in oxidative stress tolerance response.

Streptococcus mutans↗

PubMed2026

CRISPR/Cas9-Mediated Mutagenesis of OsERF94 Enhances Pre-Harvest Sprouting in Rice.

Pre-harvest sprouting (PHS), where seeds germinate on panicles before harvest under humid conditions, is a serious global issue in cereal crop production, including rice. Fine-mapping of the previously reported chromosome 4 locus identified OsERF94 as a strong candidate gene for functional validation. In this study, we investigated the role of OsERF94 in PHS using CRISPR/Cas9 gene editing. The CRISPR/Cas9-mediated mutagenesis of OsERF94 induced frameshift mutations, resulting in a loss-of-function of OsERF94 in the 1-I-ET and 2-D-ET lines. The 1-I-ET and 2-D-ET lines exhibited significantly higher germination rates under PHS conditions compared to the wild type, indicating increased susceptibility to PHS. Whole-genome re-sequencing confirmed that few or no mutations could be detected at off-target candidate sites in both edited lines, ensuring the precision of the CRISPR/Cas9 gene editing. A transcriptome analysis revealed altered expression patterns of several GA-related genes, including OsLOL1, OsKO3, OsGA3ox2, and OsGA2ox5 in the OsERF94 mutant lines. The up-regulation of GA biosynthetic genes and the down-regulation of GA deactivation genes observed in both the OsERF94 mutant lines suggest possible alterations in GA metabolism during the early stages of PHS. Transient luciferase reporter assays using a single-luciferase system suggested that OsERF94 may be associated with changes in the promoter activities of several GA- and ethylene-related genes. These findings suggest that OsERF94 may contribute to the regulation of PHS, potentially through moderation of GA- and ethylene-related pathways. Overall, this study improves our understanding of the molecular role of OsERF94 in PHS and highlights its potential as a target for the genetic improvement of PHS resistance in rice-breeding programs.

OsERF94↗

PubMed2026

Screening and identification of the ncRNA-mRNA regulatory network associated with DNA methylation in goose embryonic myoblasts.

BACKGROUND: Local goose breeds Shitou and Wuzong exhibit distinct growth rates, implying divergent embryonic muscle development. This study used embryonic myoblasts from the Magang goose, an established model with superior growth traits, to explore the underlying common regulatory mechanisms. Extending our previous findings that 5-AZA (DNA methylation inhibitor) and BC339 (DNA hydroxylation inhibitor) oppositely affect myoblast proliferation and differentiation, we performed whole-transcriptome sequencing on inhibitor-treated goose embryonic myoblasts. This aimed to identify DNA methylation-mediated ncRNA-mRNA networks governing myoblast fate, with key interactions being functionally validated. RESULT: 5-AZA significantly promotes cell proliferation and differentiation by inhibiting DNA methyltransferase activity and reducing DNA methylation levels, whereas BC339 significantly suppresses cell proliferation and differentiation by inhibiting demethylation and increasing DNA methylation levels. Specifically, we identified 6,309 mRNAs, 579 lncRNAs, 194 miRNAs, and 825 circRNAs that were differentially expressed in response to 5-AZA and BC339 treatment. Based on GO and KEGG enrichment analyses, differentially expressed genes related to muscle development were selected to construct a ceRNA network. This network comprises 5 differentially expressed lncRNAs (DELs: MSTRG.17572.1, XR_001211738.1, MSTRG.1886.1, XR_001212555.1, MSTRG.8995.2), 2 differentially expressed circRNAs (DECs: novel_circ_029953, novel_circ_017636), 11 differentially expressed miRNAs (DEMs: miR-383-x, miR-10174-y, miR-191-x, miR-24-x, miR-9619-y, novel-m0303-5p, novel-m0105-3p, miR-204-x, miR-211-z, novel-m0075, miR-26-y), 5 differentially expressed genes (DEGs: KIF3A, CCND1, PPM1A, Table 2, TGFBR1), forming a total of 24 interactions. This study identified miR-9619-y as a critical negative regulator of goose embryonic myoblast development through targeted inhibition of CCND1. Dual-luciferase reporter assays confirmed the direct binding of miR-9619-y to the 3'-untranslated region of CCND1. Functional experiments demonstrated that overexpression of miR-9619-y significantly reduced the EdU-positive cell ratio and myotube area percentage, accompanied by cell cycle arrest at the G0/G1 phase. Conversely, inhibition of miR-9619-y promoted myoblast proliferation and differentiation while decreasing the proportion of cells in G0/G1 phase. During the proliferation stage, miR-9619-y overexpression significantly suppressed CCND1 expression at both mRNA and protein levels, down-regulated MyoD expression, and reduced Myf5 mRNA abundance; whereas miR-9619-y inhibition up-regulated these genes and their corresponding proteins. During the differentiation stage, overexpression of miR-9619-y similarly decreased the mRNA levels of CCND1, Myh1, and MyoG, as well as the protein levels of MyHC and CCND1, with inhibition producing the opposite effects. CONCLUSION: In this study, we predicted a ceRNA network based on bioinformatics analysis governing goose embryonic myoblast development, identifying key molecular components including mRNAs, miRNAs, lncRNAs, and circRNAs, along with 24 regulatory axes. Functional experiments further demonstrated that miR-9619-y arrests cell cycle progression and negatively regulates the proliferation and differentiation of goose embryonic myoblasts, as evidenced by its impact on both the mRNA and protein expression of key myogenic factors through targeted inhibition of CCND1. These findings, together with the bioinformatically predicted ceRNA network, suggest potential complex post-transcriptional regulatory mechanisms underlying myogenesis in geese and offer candidate molecular targets for genetic improvement of meat production performance in waterfowl breeding programs.

Animals↗

PubMed2026

Identification of Critical Genes Related to Breast Cancer with Brain Metastasis Through Bioinformatics Analysis.

INTRODUCTION: Distant metastasis accounts for the majority of Breast Cancer (BC)-related mortality. The brain is one of the most common regions of metastasis. However, the underlying molecular mechanisms remain uncertain. METHODS: In this study, gene expression profiles were downloaded from the Gene Expression Omnibus (GEO) database. Datasets GSE100534 and GSE52604, containing 16 primary brain tumor samples and 38 breast cancer brain metastasis samples, were used to identify the Differentially Expressed Genes (DEGs). The Metascape database was used to analyze enriched Gene Ontology (GO) entries and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway entries in DEGs. The STRING database was then used to construct a Protein-Protein Interaction (PPI) network, and the Cytoscape platform was employed to visualize the network. Furthermore, the Kaplan-Meier curve was used to analyze the Relapse-Free Survival (RFS) among the hub genes. Finally, the iRegulon plugin was used to construct a regulatory network to find the transcription factors (TFs) that regulate the expression of the hub genes. RESULTS: A total of 344 DEGs, including 182 up-regulated and 162 down-regulated genes, were identified by using the limma package in R. A module with 18 nodes and 9 hub genes was selected from the PPI network by using the plugins MCODE and Cyto- Hubba, respectively. KEGG pathway analysis demonstrated that brain metastasis in BC was closely related to the oocyte cell cycle. The Kaplan-Meier curve showed that high expression of these 9 hub genes was associated with poor RFS in BC patients. TFs' analysis showed that E2F4, SIN3A, FOXM1, and TFDP1 interacted with these hub genes. DISCUSSION: This study revealed that Breast Cancer Brain Metastasis (BCBM) may have a promoting effect on the cell cycle of oocytes and affect the maturation and division of oocytes through the KEGG and GO analyses of 344 DEGs. The selected 9 hub genes (ASPM, BUB1, BUB1B, CCNA2, CCNB1, CDK1, NDC80, NCAPG, and TOP2A) and 4 transcription factors (E2F4, SIN3A, FOXM1, TFDP1) may play a critical role in brain metastasis of BC. CONCLUSION: The results of this study may aid in the early diagnosis and suggest potential targets for the treatment of BCBM.

Brain Neoplasms↗

PubMed2026

Single nucleus multiomics reveals an early inflammatory response to high-fat diet in mouse islets.

In periods of sustained hyper-nutrition, pancreatic β-cells undergo functional compensation through transcriptional upregulation of gene programs driving insulin secretion. This adaptation is essential for maintaining systemic glucose homeostasis and metabolic health. Using single nuclei multiomics, we have mapped the early transcriptional adaptive mechanisms in murine islets of Langerhans exposed to high-fat diet (HFD) for 1 and 3 wk. We show that β-cells exhibit the largest transcriptional response to HFD, characterized by early activation of pro-inflammatory eRegulons and down-regulation of β-cell identity genes, particularly in a distinct subset of β-cells. These observations extend to humans, where the prevalence of an β-cells with a high inflammatory signature is increased in diabetes. Collectively, these observations point to cellular crosstalk through pro-inflammatory signaling as a central and early driver of β-cell dysfunction that limits the compensatory capacity of β-cells, which is closely linked to the development of diabetes.

Animals↗

PubMed2026

A truncated COL10A1 protein causes Schmid metaphyseal chondrodysplasia via protein downregulation and impairing α1 trimer formation and secretion.

Schmid-type metaphyseal chondrodysplasia (SMCD) is primarily caused by mutations in the COL10A1 gene. This study reports a novel frameshift mutation, c.1940dup (p.Asn647Lysfs*2), identified in a Chinese SMCD pedigree. The mutation did not alter messenger RNA levels but significantly reduced COL10A1 protein expression. The mutant protein lacks the C-terminal 33 amino acids, resulting in a truncated polypeptide of 648 residues with a lower molecular weight than the wild-type protein. Degradation kinetics analysis showed no evidence of accelerated turnover. Notably, even under complete inhibition of degradation pathways, mutant protein expression remained substantially lower than that of wild-type, suggesting a potential defect in translational efficiency. Furthermore, the mutation severely disrupted the assembly of the characteristic collagen X trimer and led to markedly reduced extracellular secretion, as measured by accumulated protein levels in conditioned medium. These findings demonstrate that the c.1940dup mutation contributes to SMCD pathogenesis through coordinated mechanisms involving protein truncation, reduced expression, probable translational deficiency, and defective trimer formation and secretion, thereby revealing new potential therapeutic targets.

Osteochondrodysplasias↗

PubMed2026

Mechanistic insights into CAR-mediated repression of the HNF4α-FABP1 axis and inhibition of HepG2 cell proliferation.

The constitutive androstane receptor (CAR) modulates the transcription of numerous genes involving drug metabolism, energy homeostasis, and cell proliferation. While rodent studies suggest an oncogenic role for murine CAR in liver cancer development, emerging evidence indicates that human CAR (hCAR) may exhibit a tumor-suppressive role in hepatocellular carcinoma; notably, overexpressing hCAR suppresses human hepatoma cell proliferation. Yet, the molecular mechanisms whereby hCAR suppresses hepatoma cell proliferation are poorly understood. Our recent RNA-seq analysis of human hepatoma cells revealed that fatty acid binding protein 1 (FABP1), a pleiotropic modulator of lipid metabolism and cancer progression, was a top gene downregulated by hCAR. Here, we report a molecular mechanism whereby hCAR downregulates FABP1 expression by modulating HNF4α signaling. Knocking down hCAR expression in a HepG2-hCAR stable cell line restores the suppressed expression of FABP1 and HNF4α, while knocking down HNF4α alone is sufficient to suppress FABP1 expression. Luciferase reporter assays revealed concentration-dependent hCAR suppression of HNF4α-mediated FABP1 transactivation. This inhibitory crosstalk between hCAR and HNF4α was further confirmed by chromatin immunoprecipitation assays, where hCAR decreased HNF4α occupancy of the FABP1 promoter. Mechanistically, hCAR inhibits HNF4α expression by prompting deacetylation of histone H3 in the HNF4α P1 enhancer region, resulting in a repressive chromatin configuration and reduced HNF4α transcription. Furthermore, overexpressing FABP1 partially rescued hCAR-suppressed cell growth. Collectively, these results uncover the hCAR-HNF4α-FABP1 axis as a novel mechanism underlying hCAR-mediated gene repression.

Humans↗

PubMed2025

UHRF1 restricts HCoV-229E infection through epigenetic silencing of the viral receptor APN.

The emergence of SARS-CoV-2 has posed significant threats to global health, particularly for the older population. Similarly, common human coronaviruses, such as HCoV-229E, which typically cause mild cold-like symptoms, can lead to severe diseases, underscoring the need to understand virus-host interactions and identify host factors contributing to viral pathogenesis and disease progression. In this study, we perform a genome-wide CRISPR knockout screen using HCoV-229E and identify UHRF1 as a potent restriction factor. Mechanistically, UHRF1 suppresses HCoV-229E infection by downregulating the expression of its cell entry receptor, APN, through promoter hypermethylation. Focused CRISPR activation screens of UHRF1-downregulated genes confirm the critical role of APN in HCoV-229E infection and identify additional genes (e.g., SIGLEC1, PLAC8, and heparan sulfate biosynthesis genes) contributing to the restrictive functions of UHRF1. Transcriptomic and single-cell RNA sequencing analysis reveal that UHRF1 expression decreases with age, negatively correlating with increased APN expression. This age-related decline in UHRF1 is validated in primary alveolar macrophages from elderly individuals, which exhibit heightened susceptibility to HCoV-229E compared to those from younger individuals. Our findings highlight UHRF1 as a key age-related host defense factor against coronavirus and provide insights into the epigenetic regulation of viral entry receptors.

Animals↗

PubMed2025

MicroRNA-122 overexpression suppresses the colon cancer cell proliferation by downregulating the astrocyte elevated gene-1/metadherin oncoprotein.

BACKGROUND: MicroRNAs (miRNAs) are small non-coding RNAs that regulate essential cellular functions, such as cell adhesion, proliferation, migration, invasion, and programmed cell death, and therefore, alterations in miRNAs can contribute to carcinogenesis. Previous studies have shown that miRNA-122 is abundant in the liver and regulates cell proliferation, migration, and apoptosis. However, the expression pattern and mechanism of actions of miR-122 remain primarily unknown in colon cancer. METHODS: In this study, we analyzed The Cancer Genome Atlas Colon Adenocarcinoma (TCGA-COAD) database to assess the clinical significance of astrocyte elevated gene-1 (AEG-1)/metadherin (MTDH) and miR-122 in colon cancer. MiR-122 overexpression studies were performed in HCT116, SW480, and SW620 cell lines. Dual-luciferase assay was carried out to confirm the interaction between AEG-1 and miR-122. In vivo-JetPEI-transfection reagent was used for in-vivo transient transfection of miR-122 in the AOM/DSS-induced colon tumor mouse model. RESULTS: Our results demonstrate that miR-122 was downregulated in colon cancer cells, and it influences the expressions of apoptotic factors and inflammatory cytokines. MiR-122 overexpression in HCT116, SW480, and SW620 cells showed upregulation of Caspase 3, Caspase 9, and BAX and decreased expression of BCL2, which are pro-apoptotic and anti-apoptotic members that maintain a ratio between cellular survival and cell death. In vivo transient transfection of miR-122 mimic in AOM/DSS induced colon tumor mouse model showed less inflammation and disease activity. The TCGA-COAD data indicated that AEG-1 expression was higher in patients with low expression of miR-122 and lower AEG-1 expression in patients with higher expression miR-122. CONCLUSION: Our findings highlight the key role of miR-122 in the high grade of colonic inflammation, and possibly in colon cancer, and the use of miR-122 mimic might be a therapeutic option.

MicroRNAs↗

PubMed2025

Identification of circulating miRNA alterations in diabetes patients excluding periodontitis effects: insights into target gene downregulation in diabetic complications.

BACKGROUND: Diabetes mellitus (DM) induces systemic complications through chronic metabolic dysregulation. Circulating exosomal microRNAs (miRNAs) are emerging as key regulators of post-transcriptional gene expression and may drive diabetes-associated pathologies. Although miRNAs have been widely studied in diabetes, the characterization of PD-independent miRNA signatures across tissues remains limited. This study aimed to identify DM-specific miRNA alterations and their contribution to systemic metabolic dysfunction independent of PD. METHODS: Exosomes were isolated from plasma samples, and small RNA sequencing was performed to identify differentially expressed miRNAs (DE-miRs) using the limma R package. Predicted target genes were identified using TargetScan and validated through bulk RNA sequencing datasets from four tissues-foot, kidney, pancreas, and retina. Differentially expressed genes (DEGs) were analyzed, followed by Gene Ontology Biological Process (GOBP) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment to elucidate diabetes-related mechanisms. RESULTS: We identified 9 upregulated and 6 downregulated DE-miRs specific to the diabetic group. TargetScan predicted 216 upregulated and 64 downregulated target genes. Functional validation revealed that these genes were enriched in pathways related to glucose metabolism, cellular stress response, and tissue repair. Notably, SREK1 and GLIPR1 were commonly detected across all four tissues, suggesting potential systemic regulators of diabetes-related complications. CONCLUSION: This study suggests that circulating exosomal miRNAs, independent of periodontitis, may function as systemic regulators in diabetes. Unlike previous studies, which did not distinguish co-morbid periodontitis, we specifically defined PD-independent miRNA signatures and validated their cross-organ regulatory effects on target genes. Our results revealed a cross-organ miRNA-mRNA regulatory network and identified common regulatory targets. These findings provide insights into both systemic and organ-specific mechanisms underlying diabetic complications and highlight the potential of miRNAs as biomarkers and therapeutic targets.

Humans↗

PubMed2025

MLL1 downregulation drives hair cell ferroptosis via mitochondrial and endoplasmic reticulum stress mechanisms through PERK-eIF2α-ATF4-Chop and PI3K/Akt-Lrp1 signaling pathway.

BACKGROUND: Sensorineural hearing loss is characterized by irreversible hair cell (HC) degeneration. Ferroptosis, which is marked by the accumulation of reactive oxygen species and elevated levels of lipid peroxidation products, has been shown to contribute to drug-mediated auditory impairment. This study aimed to elucidate the role of mixed-lineage leukemia 1 (MLL1) in HC survival in the auditory system. METHODS: The HEI-OC1 auditory cell line and postnatal cochlear explants were evaluated using MM-102, a specific MLL1 histone methyltransferase inhibitor. Western blotting, quantitative polymerase chain reaction, electron microscopy, and immunofluorescence were used to elucidate the role of MLL1 in regulating ferroptosis in HC injury. RNA sequencing (RNA-seq) was used to analyze the molecular mechanisms of MLL1 intervention in HC injury from an epigenetic perspective. RESULTS: Our findings demonstrated that immunofluorescence staining revealed a crucial role of MM-102 in promoting intracellular accumulation of lipid peroxides and ferrous ions. Subsequent analysis showed MLL1 downregulation-induced mitochondrial dysfunction and endoplasmic reticulum (ER) stress, with transmission electron microscopy imaging confirming ultrastructural alterations in mitochondria and ER. Mechanistic investigations identified the PERK-eIF2α-ATF4-Chop signaling axis as the regulatory pathway, evidenced by Western blotting quantification of phosphorylated PERK (p-PERK), ATF4, and Chop levels. RNA-seq analysis revealed 741 differentially expressed genes (335 upregulated and 406 downregulated). Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis specifically highlighted significant enrichment of the PI3K/Akt-Lrp1 pathway, with corresponding activation patterns of phospho (p)-Akt and Lrp1 confirmed through Western blotting analysis. CONCLUSIONS: MLL1 downregulation initiates ferroptosis in cochlear HCs. This process is intrinsically associated with the activation of mitochondrial dysfunction and ER stress. The study highlights the importance of MLL1 in HC survival, suggesting its potential as a therapeutic target for treating hearing loss.

Endoplasmic Reticulum Stress↗