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1.
Clin Res Hepatol Gastroenterol ; 48(7): 102398, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38871250

ABSTRACT

BACKGROUND: Cholangiocarcinoma is a malignant tumor that occurs in the bile duct system, and the prognosis of patients is poor. Currently, research suggests that long non-coding RNAs (lncRNAs) in the treatment and prevention of cholangiocarcinoma. This study primarily focuses on the regulation and potential mechanism of the lncRNA XIST (XIST) in cholangiocarcinoma. METHODS: The levels of XIST and miR-126-3p in cholangiocarcinoma tissues and cells were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Cell transfection status, including migration and invasion, was examined via the Transwell method. The relationship between XIST and miR-126-3p was observed by dual-luciferase gene reporter assay and verified by rescue assays. Additionally, the prognostic significance of XIST in cholangiocarcinoma was determined using Kaplan-Meier and multivariate Cox regression analyses. RESULTS: XIST expression was increased in cholangiocarcinoma, while miR-126-3p was decreased, in both tissues and cells. The successful construction of silencing XIST was found to inhibit the count of cell migration and invasion. XIST directly targeted miR-126-3p to regulate the progression of cholangiocarcinoma. CONCLUSION: XIST sponging miR-126-3p inhibited the progression of cholangiocarcinoma and improved the prognosis for patients. This finding provides new insights and opportunities for future studies on cholangiocarcinoma prognostic biomarkers.

2.
Elife ; 132024 Jun 18.
Article in English | MEDLINE | ID: mdl-38896448

ABSTRACT

ASARs are a family of very-long noncoding RNAs that control replication timing on individual human autosomes, and are essential for chromosome stability. The eight known ASAR lncRNAs remain closely associated with their parent chromosomes. Analysis of RNA-protein interaction data (from ENCODE) revealed numerous RBPs with significant interactions with multiple ASAR lncRNAs, with several hnRNPs as abundant interactors. An ~7 kb domain within the ASAR6-141 lncRNA shows a striking density of RBP interaction sites. Genetic deletion and ectopic integration assays indicate that this ~7 kb RNA binding protein domain contains functional sequences for controlling replication timing of entire chromosomes in cis. shRNA-mediated depletion of 10 different RNA binding proteins, including HNRNPA1, HNRNPC, HNRNPL, HNRNPM, HNRNPU, or HNRNPUL1, results in dissociation of ASAR lncRNAs from their chromosome territories, and disrupts the synchronous replication that occurs on all autosome pairs, recapitulating the effect of individual ASAR knockouts on a genome-wide scale. Our results further demonstrate the role that ASARs play during the temporal order of genome-wide replication, and we propose that ASARs function as essential RNA scaffolds for the assembly of hnRNP complexes that help maintain the structural integrity of each mammalian chromosome.


Subject(s)
Heterogeneous-Nuclear Ribonucleoproteins , RNA, Long Noncoding , RNA, Long Noncoding/metabolism , RNA, Long Noncoding/genetics , Humans , Heterogeneous-Nuclear Ribonucleoproteins/metabolism , Heterogeneous-Nuclear Ribonucleoproteins/genetics , DNA Replication Timing , Protein Binding , RNA-Binding Proteins/metabolism , RNA-Binding Proteins/genetics
3.
Forensic Sci Int ; 361: 112081, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38850616

ABSTRACT

Forensic sample screening is important for establishing an effective DNA typing workflow. The detection of sex-specific markers in forensic samples highlights the necessity for further analysis. Y-chromosome DNA can confirm male contributions, but female contributions are difficult to confirm using DNA-based methods. To address this, we developed a colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay targeting the long non-coding RNA X-inactive specific transcript (XIST) to screen female samples. Operating at 65 °C for 30 min, the assay yielded results discernible from the color change of the pH indicator dye. The assay showed a detection limit of approximately 0.5 µL of blood. The assay also detected XIST RNA in mixed body fluids and mock samples, indicating its potential applicability to casework samples. Taken together, our assay provides a rapid and simple strategy for screening female samples.

4.
Genome Biol ; 25(1): 144, 2024 05 31.
Article in English | MEDLINE | ID: mdl-38822397

ABSTRACT

BACKGROUND: Variation in X chromosome inactivation (XCI) in human-induced pluripotent stem cells (hiPSCs) can impact their ability to model biological sex biases. The gene-wise landscape of X chromosome gene dosage remains unresolved in female hiPSCs. To characterize patterns of de-repression and escape from inactivation, we performed a systematic survey of allele specific expression in 165 female hiPSC lines. RESULTS: XCI erosion is non-random and primarily affects genes that escape XCI in human tissues. Individual genes and cell lines vary in the frequency and degree of de-repression. Bi-allelic expression increases gradually after modest decrease of XIST in cultures, whose loss is commonly used to mark lines with eroded XCI. We identify three clusters of female lines at different stages of XCI. Increased XCI erosion amplifies female-biased expression at hypomethylated sites and regions normally occupied by repressive histone marks, lowering male-biased differences in the X chromosome. In autosomes, erosion modifies sex differences in a dose-dependent way. Male-biased genes are enriched for hypermethylated regions, and de-repression of XIST-bound autosomal genes in female lines attenuates normal male-biased gene expression in eroded lines. XCI erosion can compensate for a dominant loss of function effect in several disease genes. CONCLUSIONS: We present a comprehensive view of X chromosome gene dosage in hiPSCs and implicate a direct mechanism for XCI erosion in regulating autosomal gene expression in trans. The uncommon and variable reactivation of X chromosome genes in female hiPSCs can provide insight into X chromosome's role in regulating gene expression and sex differences in humans.


Subject(s)
Chromosomes, Human, X , Induced Pluripotent Stem Cells , RNA, Long Noncoding , X Chromosome Inactivation , Humans , Induced Pluripotent Stem Cells/metabolism , Female , Chromosomes, Human, X/genetics , Male , RNA, Long Noncoding/genetics , Alleles , Gene Expression Regulation , DNA Methylation
5.
Per Med ; : 1-13, 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38889283

ABSTRACT

There is a significant mortality rate associated with cardiovascular disease despite advances in treatment. long Non-coding RNAs (lncRNAs) play a critical role in many biological processes and their dysregulation is associated with a wide range of diseases in which their downstream pathways are disrupted. A lncRNA X-inactive specific transcript (XIST) is well known as a factor that regulates the physiological process of chromosome dosage compensation for females. According to recent studies, lncRNA XIST is involved in a variety of cellular processes, including apoptosis, proliferation, invasion, metastasis, oxidative stress and inflammation, through molecular networks with microRNAs and their downstream targets in neoplastic and non-neoplastic diseases. Because these cellular processes play a role in the pathogenesis of cardiovascular diseases, we aim to investigate the role that lncRNA XIST plays in this process. Additionally, we wish to determine whether it is a prognostic factor or a potential therapeutic target in these diseases.


[Box: see text].

6.
Biochem Soc Trans ; 52(3): 1099-1107, 2024 Jun 26.
Article in English | MEDLINE | ID: mdl-38747697

ABSTRACT

The long non-coding RNA (lncRNA) Xist is crucially involved in a process called X chromosome inactivation (XCI), the transcriptional silencing of one of the two X chromosomes in female mammals to achieve X dosage compensation between the sexes. Because Xist RNA silences the X chromosome from which it is transcribed, the activation of Xist transcription marks the initiation of the XCI process and thus, mechanisms and players that activate this gene are of central importance to the XCI process. During female mouse embryogenesis, XCI occurs in two steps. At the 2-4 cell stages imprinted XCI (iXCI) silences exclusively the paternally inherited X chromosome (Xp). While extraembryonic cells including trophoblasts keep the Xp silenced, epiblast cells that give rise to the embryo proper reactivate the Xp and undergo random XCI (rXCI) around implantation. Both iXCI and rXCI are dependent on Xist. Rlim, also known as Rnf12, is an X-linked E3 ubiquitin ligase that is involved in the transcriptional activation of Xist. However, while data on the crucial involvement of Rlim during iXCI appear clear, its role in rXCI has been controversial. This review discusses data leading to this disagreement and recent evidence for a regulatory switch of Xist transcription in epiblasts of implanting embryos, partially reconciling the roles of Rlim during Xist activation.


Subject(s)
RNA, Long Noncoding , Ubiquitin-Protein Ligases , X Chromosome Inactivation , Animals , Female , Mice , Gene Expression Regulation, Developmental , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitin-Protein Ligases/genetics , X Chromosome/genetics , X Chromosome/metabolism
7.
Arch Endocrinol Metab ; 68: e230097, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38739522

ABSTRACT

Objective: This study sought to investigate the regulation of long noncoding RNA (lncRNA) XIST on the microRNA (miR)-101-3p/vascular endothelial growth factor A (VEGFA) axis in neovascularization in diabetic retinopathy (DR). Materials and methods: Serum of patients with DR was extracted for the analysis of XIST, miR-101-3p, and VEGFA expression levels. High glucose (HG)-insulted HRMECs and DR model rats were treated with lentiviral vectors. MTT, transwell, and tube formation assays were performed to evaluate cell viability, migration, and angiogenesis, and ELISA was conducted to detect the levels of inflammatory cytokines. Dual-luciferase reporter, RIP, and RNA pull-down experiments were used to validate the relationships among XIST, miR-101-3p, and VEGFA. Results: XIST and VEGFA were upregulated and miR-101-3p was downregulated in serum from patients with DR. XIST knockdown inhibited proliferation, migration, vessel tube formation, and inflammatory responsein HG-treated HRMECs, whereas the above effects were nullified by miR-101-3p inhibition or VEGFA overexpression. miR-101-3p could bind to XIST and VEGFA. XIST promoted DR development in rats by regulating the miR-101-3p/VEGFA axis. Conclusion: LncRNA XIST promotes VEGFA expression by downregulating miR-101-3p, thereby stimulating angiogenesis and inflammatory response in DR.


Subject(s)
Diabetic Retinopathy , MicroRNAs , Neovascularization, Pathologic , RNA, Long Noncoding , Vascular Endothelial Growth Factor A , RNA, Long Noncoding/genetics , Diabetic Retinopathy/genetics , Diabetic Retinopathy/blood , Vascular Endothelial Growth Factor A/metabolism , Animals , Rats , Humans , Male , Neovascularization, Pathologic/genetics , Rats, Sprague-Dawley , Female , Cell Movement/genetics , Cell Proliferation/genetics , Middle Aged , Diabetes Mellitus, Experimental
8.
Cytogenet Genome Res ; : 1-10, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38754392

ABSTRACT

INTRODUCTION: X chromosome inactivation (XCI) is an essential mechanism for dosage compensation between females and males in mammals. In females, XCI is controlled by a complex, conserved locus termed the X inactivation center (Xic), in which the lncRNA Xist is the key regulator. However, little is known about the Xic in species with unusual sex chromosomes. The genus Tokudaia includes three rodent species endemic to Japan. Tokudaia osimensis and Tokudaia tokunoshimensis lost the Y chromosome (XO/XO), while Tokudaia muenninki (TMU) acquired a neo-X region by fusion of the X chromosome and an autosome (XX/XY). We compared the gene location and structure in the Xic among Tokudaia species. METHODS: Gene structure of nine genes in Xic was predicted, and the gene location and genome sequences of Xic were compared between mouse and Tokudaia species. The expression level of the gene was confirmed by transcripts per million calculation using RNA-seq data. RESULTS: Compared to mouse, the Xic gene order and location were conserved in Tokudaia species. However, remarkable structure changes were observed in lncRNA genes, Xist and Tsix, in the XO/XO species. In Xist, important functional repeats, B-, C-, D-, and E-repeats, were partially or completely lost due to deletions in these species. RNA-seq data showed that female-specific expression patterns of Xist and Tsix were confirmed in TMU, however, not in the XO/XO species. Additionally, three deletions and one inversion were confirmed in the intergenic region between Jpx and Ftx in the XO/XO species. CONCLUSION: Our findings indicate that even if the Xist and Tsix lncRNAs are expressed, they are incapable of producing a successful and lasting XCI in the XO/XO species. We hypothesized that the significant structure change in the intergenic region of Jpx-Ftx resulted in the inability to perform the XCI, and, as a result, a lack of Xist expression. Our results collectively suggest that structural changes in the Xic occurred in the ancestral lineage of XO/XO species, likely due to the loss of one X chromosome and the Y chromosome as a consequence of the degradation of the XCI system.

9.
Biomedicines ; 12(5)2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38790894

ABSTRACT

Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14-16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients' blood.

10.
Mol Cell ; 84(10): 1870-1885.e9, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38759625

ABSTRACT

How Polycomb repressive complex 2 (PRC2) is regulated by RNA remains an unsolved problem. Although PRC2 binds G-tracts with the potential to form RNA G-quadruplexes (rG4s), whether rG4s fold extensively in vivo and whether PRC2 binds folded or unfolded rG4 are unknown. Using the X-inactivation model in mouse embryonic stem cells, here we identify multiple folded rG4s in Xist RNA and demonstrate that PRC2 preferentially binds folded rG4s. High-affinity rG4 binding inhibits PRC2's histone methyltransferase activity, and stabilizing rG4 in vivo antagonizes H3 at lysine 27 (H3K27me3) enrichment on the inactive X chromosome. Surprisingly, mutagenizing the rG4 does not affect PRC2 recruitment but promotes its release and catalytic activation on chromatin. H3K27me3 marks are misplaced, however, and gene silencing is compromised. Xist-PRC2 complexes become entrapped in the S1 chromosome compartment, precluding the required translocation into the S2 compartment. Thus, Xist rG4 folding controls PRC2 activity, H3K27me3 enrichment, and the stepwise regulation of chromosome-wide gene silencing.


Subject(s)
G-Quadruplexes , Histones , Polycomb Repressive Complex 2 , RNA, Long Noncoding , X Chromosome Inactivation , Animals , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Mice , Polycomb Repressive Complex 2/metabolism , Polycomb Repressive Complex 2/genetics , Histones/metabolism , Histones/genetics , Mouse Embryonic Stem Cells/metabolism , Chromatin/metabolism , Chromatin/genetics , X Chromosome/genetics , X Chromosome/metabolism , Gene Silencing , RNA Folding , Protein Binding
11.
Technol Health Care ; 2024 May 11.
Article in English | MEDLINE | ID: mdl-38820035

ABSTRACT

BACKGROUND: Long noncoding RNAs (lncRNAs) participate in diseases, especially tumorigenesis, including gastric cancer (GC). Although lncRNAs in GC tissues have been extensively studied in previous research, the possible significance of circulating lncRNAs in diagnosing GC is still unknown. OBJECTIVE: The present work investigated lncRNAs ZFPM2-AS1 and XIST with high expression in GC tissues proved as potential plasma biomarkers from 20 early GC cases, 100 GC cases, and 90 normal subjects. METHODS: The possible correlation between ZFPM2-AS1 and XIST expression levels was analyzed with general characteristics and clinicopathological features. The performance in diagnosis was assessed according to receiver operating characteristic (ROC) analysis. RESULTS: According to the results, XIST and ZFPM2-AS1 expression remarkably increased within GC plasma relative to normal subjects (P< 0.01); besides, lncRNA XIST expression after surgery had a tendency of downregulation compared with preoperative levels (P< 0.05). Moreover, the area under ROC curve (AUC) values were 0.62 for ZFPM2-AS1 and 0.68 for XIST, while the pooled AUC value of CA-724 and two lncRNAs was 0.751. CONCLUSION: Circulating lncRNAs ZFPM2-AS1 and XIST can serve as the candidate plasma biomarkers used to diagnose GC.

12.
Biomed Pharmacother ; 175: 116636, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38677245

ABSTRACT

PURPOSE: Renal interstitial fibrosis is a pathological manifestation of the progression of diabetic kidney disease (DKD). Dendrobium officinale polysaccharides (DOP), one of the major active components of Dendrobium officinale, have hypoglycemic and hypolipidemic effects and are used clinically to treat diabetes. However, the role of DOP in delaying DKD progression remains unclear. This study aimed to explore the potential mechanisms by which DOP delays DKD renal interstitial fibrosis. METHODS: Using db/db mice as a model of DKD, we administered DOP by gavage and observed its therapeutic effectiveness. Employing ASO technology, we knocked down lncRNA XIST expression in kidney tissues and detected the expression of lncRNA XIST, TGF-ß1, and renal interstitial fibrosis-related molecules. RESULTS: DOP was primarily composed of monosaccharides, with 91.57% glucose and 1.41% mannose, forming a spheroid-like structure. It has a high polydispersity index with an Mw/Mn of 6.146, and the polysaccharides are mainly connected by 4-Man(p) and 4-Glc(p) linkages. In the kidneys of db/db mice, lncRNA XIST and TGF-ß1 are highly expressed; however, their expression is significantly reduced after gastric infusion with DOP, and upon knockdown of lncRNA XIST, it might delay the progression of renal interstitial fibrosis in DKD. CONCLUSION: DOP may delay the progression of DKD renal interstitial fibrosis through the regulation of the LncRNA XIST/TGF-ß1 related fibrotic pathway. This provides a new perspective for clinical strategies to delay the progression of DKD renal interstitial fibrosis.


Subject(s)
Dendrobium , Diabetic Nephropathies , Fibrosis , Mice, Inbred C57BL , Polysaccharides , RNA, Long Noncoding , Transforming Growth Factor beta1 , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Animals , Dendrobium/chemistry , Diabetic Nephropathies/metabolism , Diabetic Nephropathies/pathology , Diabetic Nephropathies/genetics , Polysaccharides/pharmacology , Transforming Growth Factor beta1/metabolism , Male , Mice , Kidney/pathology , Kidney/drug effects , Kidney/metabolism
14.
Br J Pharmacol ; 181(15): 2509-2527, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38589338

ABSTRACT

BACKGROUND AND PURPOSE: It is well acknowledged that tobacco-derived lung carcinogens can induce lung injury and even lung cancer through a complex mechanism. MicroRNAs (MiRNAs) are differentially expressed in tobacco-derived carcinogen nicotine-derived nitrosamine ketone (NNK)-treated A/J mice. EXPERIMENTAL APPROACH: RNA sequencing was used to detect the level of long non-coding RNAs (lncRNAs). Murine and human lung normal and cancer cells were used to evaluate the function of lncRNA XIST and miR-328-3p in vitro, and NNK-treated A/J mice were used to test their function in vivo. In vivo levels of miR-328-3p and lncRNA XIST were analysed, using in situ hybridization. miR-328-3p agomir and lncRNA XIST-specific siRNA were used to manipulate in vivo levels of miR-328-3p and lncRNA XIST in A/J mice. KEY RESULTS: LncRNA XIST was up-regulated in NNK-induced lung injury and dominated the NNK-induced ectopic miRNA expression in NNK-induced lung injury both in vitro and in vivo. Either lncRNA XIST silencing or miR-328-3p overexpression exerted opposing effects in lung normal and cancer cells regarding cell migration. LncRNA XIST down-regulated miR-328-3p levels as a miRNA sponge, and miR-328-3p targeted the 3'-UTR of FZD7 mRNA, which is ectopically overexpressed in lung cancer patients. Both in vivo lncRNA XIST silencing and miR-328 overexpression could rescue NNK-induced lung injury and aberrant overexpression of the lung cancer biomarker CK19 in NNK-treated A/J mice. CONCLUSIONS AND IMPLICATIONS: Our results highlight the promotive effect of lncRNA XIST in NNK-induced lung injury and elucidate its post-transcriptional mechanisms, indicating that targeting lncRNA XIST/miR-328-3p could be a potential therapeutic strategy to prevent tobacco carcinogen-induced lung injury in vivo.


Subject(s)
Carcinogens , MicroRNAs , Nitrosamines , RNA, Long Noncoding , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Animals , Nitrosamines/toxicity , MicroRNAs/genetics , MicroRNAs/metabolism , Mice , Humans , Carcinogens/toxicity , Lung Injury/chemically induced , Lung Injury/metabolism , Lung Injury/genetics , Lung Neoplasms/chemically induced , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Male , Nicotiana
15.
Biochem Genet ; 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38609670

ABSTRACT

The polycystic ovary syndrome (PCOS), a common endocrine disorder, is mainly related to infertility. Moreover, it is characterized by promoted androgen, suppressed ovulation and insulin resistance. Long non-coding RNA X inactive specific transcript (lncRNA XIST), known as an oncogene or a cancer inhabited factor, is involved in several disease. However, the diagnostic mechanisms of lncRNA XIST in PCOS have not been clarified. Our study aimed to explain whether lncRNA XIST regulates KGN cells proliferation and apoptosis via microRNA (miR)-212-3p/RASA1 axis in PCOS. Levels of lncRNA XIST, miR-212-3p and RASA1 in KGN cells were detected through reverse transcription quantitative polymerase chain reaction (RT-qPCR) assay. Fluorescence in situ Hybridization (FISH) was performed to confirm the expression of lncRNA XIST and miR-212-3p in KGN cells. StarBase and dual-luciferase reporter assay were applied for exploring the interaction between miR-212-3p and RASA1. Cell viability, apoptosis, protein expression of Bcl-2 and Bax were assessed by MTT, flow cytometry analysis, RT-qPCR and western blot, respectively. We found that lncRNA XIST was low-expressed, miR-212-3p was over-expressed, and RASA1 was dramatically down-regulated in KGN cells. LncRNA XIST negatively regulated miR-212-3p expression in KGN cells. MiR-212-3p interacted with RASA1 and negatively regulated RASA1 levels in KGN cells. Up-regulation of lncRNA XIST signally decreased cells viability, stimulated more apoptotic cells, enhanced Bax expression, and depressed Bcl-2 level in KGN cells. However, these observations were abolished after miR-212-3p mimic treatment. Furthermore, miR-212-3p inhibitor significantly inhibited cell proliferation, enhanced more apoptotic cells, increased Bax expression, and decreased Bcl-2 level in KGN cells, and these effects were eliminated by RASA1-siRNA transfection. Our observations revealed that lncRNA XIST protects against PCOS through regulating miR-212-3p/RASA1 axis, suggesting that lncRNA XIST may be a promising therapeutic target for PCOS therapy.

16.
EMBO Rep ; 25(5): 2258-2277, 2024 May.
Article in English | MEDLINE | ID: mdl-38654121

ABSTRACT

X chromosome inactivation (XCI) in mammals is mediated by Xist RNA which functions in cis to silence genes on a single X chromosome in XX female cells, thereby equalising levels of X-linked gene expression relative to XY males. XCI progresses over a period of several days, with some X-linked genes silencing faster than others. The chromosomal location of a gene is an important determinant of silencing rate, but uncharacterised gene-intrinsic features also mediate resistance or susceptibility to silencing. In this study, we examine mouse embryonic stem cell lines with an inducible Xist allele (iXist-ChrX mESCs) and integrate allele-specific data of gene silencing and decreasing inactive X (Xi) chromatin accessibility over time courses of Xist induction with cellular differentiation. Our analysis reveals that motifs bound by the transcription factor YY1 are associated with persistently accessible regulatory elements, including many promoters and enhancers of slow-silencing genes. We further show that YY1 is evicted relatively slowly from target sites on Xi, and that silencing of X-linked genes is increased upon YY1 degradation. Together our results suggest that YY1 acts as a barrier to Xist-mediated silencing until the late stages of the XCI process.


Subject(s)
Gene Silencing , RNA, Long Noncoding , X Chromosome Inactivation , YY1 Transcription Factor , Animals , YY1 Transcription Factor/metabolism , YY1 Transcription Factor/genetics , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Mice , X Chromosome Inactivation/genetics , Mouse Embryonic Stem Cells/metabolism , Female , Male , Protein Binding , Cell Differentiation/genetics , Chromatin/metabolism , Chromatin/genetics , Promoter Regions, Genetic , Cell Line , X Chromosome/genetics , X Chromosome/metabolism , Alleles
17.
Carcinogenesis ; 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38426786

ABSTRACT

Approximately one-third of activated B-cell-like diffuse large B-cell lymphoma (ABC-DLBCL) cases were unresponsive to standard first-line therapy; thus, identifying biomarkers to evaluate therapeutic efficacy and assessing the emergence of drug resistance is crucial. Through early-stage screening, long noncoding RNA (lncRNA) X-inactive specific transcript (XIST) was found to be correlated with the R-CHOP treatment response. This study aimed to clarify the characteristics of XIST in ABC-DLBCL. The expression level of XIST in 161 patients with ABC-DLBCL receiving R-CHOP therapy was examined via RNA in situ hybridization, and the association between XIST expression and clinicopathological features, treatment response, and prognosis was analyzed in the study cohort and validated in the Gene Expression Omnibus cohort. Cell biological experiments and bioinformatics analyses were conducted to reveal aberrant signaling. The proportion of complete response in patients with high XIST expression was lower than that in patients with low XIST expression (53.8% vs. 77.1%) (P = 0.002). High XIST expression was remarkably associated with the characteristics of tumor progression and was an independent prognostic element for overall survival (P = 0.039) and progression-free survival (P = 0.027) in ABC-DLBCL. XIST was proven to be involved in m6A-related methylation and ATF6-associated autophagy. XIST knockdown repressed ABC-DLBCL cellular proliferation by regulating Raf/MEK/ERK signaling. High XIST expression was associated with ABC-DLBCL tumorigenesis and development and contributed to R-CHOP treatment resistance. XIST may be a promising signal to predict ABC-DLBCL prognosis.

18.
Immunobiology ; 229(3): 152796, 2024 May.
Article in English | MEDLINE | ID: mdl-38484431

ABSTRACT

BACKGROUND: We have previously found that enhancer of zeste homolog 2 (EZH2) is correlated with inflammatory infiltration and mucosal cell injury in ulcerative colitis (UC). This study aims to analyze the role of X-inactive specific transcript (XIST), a possible interactive long non-coding RNA of EZH2, in UC and to explore the mechanisms. METHODS: C57BL/6N mice were treated with dextran sulfate sodium (DSS), and mouse colonic mucosal epithelial cells were treated with DSS and lipopolysaccharide (LPS) for UC modeling. The UC-related symptoms in mice, and the viability and apoptosis of mucosal epithelial cells were determined. Inflammatory injury in animal and cellular models were assessed through the levels of ACS, occludin, IL-1ß, IL-18, TNF-α, caspase-1, and caspase-11. Molecular interactions between XIST, EZH2, and GABA type A receptor-associated protein (GABARAP) were verified by immunoprecipitation assays, and their functions in inflammatory injury were determined by gain- or loss-of-function assays. RESULTS: XIST was highly expressed in DSS-treated mice and in DSS + LPS-treated mucosal epithelial cells. It recruited EZH2, which mediated gene silencing of GABARAP through H3K27me3 modification. Silencing of XIST alleviated body weight loss, colon shortening, and disease active index of mice and reduced inflammatory injuries in their colon tissues. Meanwhile, it reduced apoptosis and inflammation in mucosal epithelial cells. However, these alleviating effects were blocked by either EZH2 overexpression or GABARAP knockdown. Rescue experiments identified caspase-11 as a key effector mediating the inflammatory injury following GABARAP loss. CONCLUSION: This study suggests that the XIST-EZH2 interaction-mediated GABARAP inhibition activates caspase-11-dependent inflammatory injury in UC.


Subject(s)
Apoptosis Regulatory Proteins , Caspases, Initiator , Colitis, Ulcerative , Disease Models, Animal , Enhancer of Zeste Homolog 2 Protein , RNA, Long Noncoding , Animals , Colitis, Ulcerative/metabolism , Colitis, Ulcerative/chemically induced , RNA, Long Noncoding/genetics , Enhancer of Zeste Homolog 2 Protein/metabolism , Mice , Caspases, Initiator/metabolism , Apoptosis Regulatory Proteins/metabolism , Apoptosis Regulatory Proteins/genetics , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Mice, Inbred C57BL , Dextran Sulfate , Apoptosis , Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Signal Transducing/genetics , Inflammation/metabolism , Humans , Male , Lipopolysaccharides , Colon/pathology , Colon/metabolism
19.
Mol Cell ; 84(8): 1442-1459.e7, 2024 Apr 18.
Article in English | MEDLINE | ID: mdl-38458200

ABSTRACT

In mammals, dosage compensation involves two parallel processes: (1) X inactivation, which equalizes X chromosome dosage between males and females, and (2) X hyperactivation, which upregulates the active X for X-autosome balance. The field currently favors models whereby dosage compensation initiates "de novo" during mouse development. Here, we develop "So-Smart-seq" to revisit the question and interrogate a comprehensive transcriptome including noncoding genes and repeats in mice. Intriguingly, de novo silencing pertains only to a subset of Xp genes. Evolutionarily older genes and repetitive elements demonstrate constitutive Xp silencing, adopt distinct signatures, and do not require Xist to initiate silencing. We trace Xp silencing backward in developmental time to meiotic sex chromosome inactivation in the male germ line and observe that Xm hyperactivation is timed to Xp silencing on a gene-by-gene basis. Thus, during the gamete-to-embryo transition, older Xp genes are transmitted in a "pre-inactivated" state. These findings have implications for the evolution of imprinting.


Subject(s)
RNA, Long Noncoding , X Chromosome Inactivation , Female , Mice , Male , Animals , X Chromosome Inactivation/genetics , Genomic Imprinting , Germ Cells , Epigenesis, Genetic , Embryo, Mammalian , RNA, Long Noncoding/genetics , X Chromosome/genetics , Mammals/genetics
20.
Sci Rep ; 14(1): 6180, 2024 03 14.
Article in English | MEDLINE | ID: mdl-38486041

ABSTRACT

Long non-coding RNA (lncRNA) regulates many physiological processes by acting as competitive endogenous RNA (ceRNA). The dysregulation of lncRNA X-inactive specific transcript (XIST) has been shown in various human disorders. However, its role in the pathogenesis of polycystic ovary syndrome (PCOS) is yet to be explored. This study aimed to explore the underlying mechanism of XIST in the pathogenesis of PCOS, specifically through dataset functional analysis. GEO PCOS datasets including RNA-seq, microarray, and miRNA-seq in granulosa cells (GCs) and blood, were examined and comprehensively analyzed. Enrichment analysis, ROC curve constructions, lncRNA-miRNA-mRNA interaction network analyses, and qRT-PCR validation were performed followed by a series of drug signature screenings. Our results revealed significant dysregulation in the expression of 1131 mRNAs, 30 miRNAs, and XIST in GCs of PCOS patients compared to healthy individuals. Of the120 XIST-correlated upregulated genes, 25 were enriched in inflammation-related pathways. Additionally, 5 miRNAs were identified as negative regulators of XIST-correlated genes. Accordingly, a ceRNA network containing XIST-miRNAs-mRNAs interactions was constructed. Furthermore, 6 genes, including AQP9, ETS2, PLAU, PLEK, SOCS3, and TNFRSF1B served as both GCs and blood-based biomarkers. By analyzing the number of interactions among XIST, miRNAs, and mRNAs, we pinpointed ETS2 as the pivotal gene within the ceRNA network. Our findings reveal a novel XIST- hsa-miR-146a-5p, hsa-miR-144-3p, and hsa-miR-1271-5p-ETS2 axis that comprehensively elucidates the XIST-associated mechanism underlying PCOS onset. qRT-PCR analysis further confirmed the, overexpression of both XIST and ETS2 . Furthermore, our results demonstrated that XIST and ETS2 were correlated with some assisted reproductive technologies outcomes. Finally, we identified two novel compounds including, methotrexate/folate and threonine using drug-gene interaction databases for PCOS management. These findings provide novel insights into the molecular etiology, diagnosis, and potential therapeutic interventions for PCOS.


Subject(s)
MicroRNAs , Polycystic Ovary Syndrome , RNA, Long Noncoding , Female , Humans , MicroRNAs/genetics , Polycystic Ovary Syndrome/genetics , RNA, Competitive Endogenous , RNA, Long Noncoding/genetics , Transcriptome
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