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Cell Reports Oct 2023Perturbing the transcriptome of mammalian oocytes results in meiotic failure. We previously reported that RNA-exosome-associated RNase, EXOSC10, degrades unwanted...
Perturbing the transcriptome of mammalian oocytes results in meiotic failure. We previously reported that RNA-exosome-associated RNase, EXOSC10, degrades unwanted protein-coding RNA and processes ribosomal RNA to ensure proper oocyte maturation. Here, we establish oocyte-specific knockout mice of another RNA-exosome-associated RNase, DIS3. Mutant females (Dis3) exhibit significantly reduced fertility because oocytes arrest after the growth phase. Single-oocyte RNA sequencing (RNA-seq) and CUT&Tag analyses show that DIS3 degrades intergenic RNA and mediates transcription silencing that is essential for chromatin condensation and resumption of meiosis. Dis3 oocytes exhibit elevated H3K27me3 in a pre-defined manner due to insufficient demethylation. During oocyte growth, EXOSC10 functions with DIS3 to degrade intergenic RNA. Double-knockout oocytes have earlier growth defects and more accumulated transcripts. We conclude that RNA exosomes synergistically degrade unwanted RNA and mediate transcription termination to ensure transcriptome integrity during oocyte development.
Topics: Mice; Animals; Female; RNA Polymerase II; Exosomes; Oocytes; Meiosis; RNA; Endoribonucleases; Fertility; Mammals
PubMed: 37831603
DOI: 10.1016/j.celrep.2023.113247 -
JCI Insight Dec 2023Regulatory T cells (Tregs) have potential for the treatment of autoimmune diseases and graft rejection. Antigen specificity and functional stability are considered...
Regulatory T cells (Tregs) have potential for the treatment of autoimmune diseases and graft rejection. Antigen specificity and functional stability are considered critical for their therapeutic efficacy. In this study, expansion of human Tregs in the presence of porcine PBMCs (xenoantigen-expanded Tregs, Xn-Treg) allowed the selection of a distinct Treg subset, coexpressing the activation/memory surface markers HLA-DR and CD27 with enhanced proportion of FOXP3+Helios+ Tregs. Compared with their unsorted and HLA-DR+CD27+ double-positive (DP) cell-depleted Xn-Treg counterparts, HLA-DR+CD27+ DP-enriched Xn-Tregs expressed upregulated Treg function markers CD95 and ICOS with enhanced suppression of xenogeneic but not polyclonal mixed lymphocyte reaction. They also had less Treg-specific demethylation in the region of FOXP3 and were more resistant to conversion to effector cells under inflammatory conditions. Adoptive transfer of porcine islet recipient NOD/SCID IL2 receptor γ-/- mice with HLA-DR+CD27+ DP-enriched Xn-Tregs in a humanized mouse model inhibited porcine islet graft rejection mediated by 25-fold more human effector cells. The prolonged graft survival was associated with enhanced accumulation of FOXP3+ Tregs and upregulated expression of Treg functional genes, IL10 and cytotoxic T lymphocyte antigen 4, but downregulated expression of effector Th1, Th2, and Th17 cytokine genes, within surviving grafts. Collectively, human HLA-DR+CD27+ DP-enriched Xn-Tregs expressed a specific regulatory signature that enabled identification and isolation of antigen-specific and functionally stable Tregs with potential as a Treg-based therapy.
Topics: Mice; Humans; Animals; Swine; T-Lymphocytes, Regulatory; Mice, SCID; Mice, Inbred NOD; HLA-DR Antigens; Forkhead Transcription Factors
PubMed: 37874660
DOI: 10.1172/jci.insight.162978 -
Cancers Jul 2023Since their discovery at the beginning of this millennium, glioma stem cells (GSCs) have sparked extensive research and an energetic scientific debate about their... (Review)
Review
Since their discovery at the beginning of this millennium, glioma stem cells (GSCs) have sparked extensive research and an energetic scientific debate about their contribution to glioblastoma (GBM) initiation, progression, relapse, and resistance. Different molecular subtypes of GBM coexist within the same tumor, and they display differential sensitivity to chemotherapy. GSCs contribute to tumor heterogeneity and recapitulate pathway alterations described for the three GBM subtypes found in patients. GSCs show a high degree of plasticity, allowing for interconversion between different molecular GBM subtypes, with distinct proliferative potential, and different degrees of self-renewal and differentiation. This high degree of plasticity permits adaptation to the environmental changes introduced by chemo- and radiation therapy. Evidence from mouse models indicates that GSCs repopulate brain tumors after therapeutic intervention, and due to GSC plasticity, they reconstitute heterogeneity in recurrent tumors. GSCs are also inherently resilient to standard-of-care therapy, and mechanisms of resistance include enhanced DNA damage repair, MGMT promoter demethylation, autophagy, impaired induction of apoptosis, metabolic adaptation, chemoresistance, and immune evasion. The remarkable oncogenic properties of GSCs have inspired considerable interest in better understanding GSC biology and functions, as they might represent attractive targets to advance the currently limited therapeutic options for GBM patients. This has raised expectations for the development of novel targeted therapeutic approaches, including targeting GSC plasticity, chimeric antigen receptor T (CAR T) cells, and oncolytic viruses. In this review, we focus on the role of GSCs as drivers of GBM and therapy resistance, and we discuss how insights into GSC biology and plasticity might advance GSC-directed curative approaches.
PubMed: 37444568
DOI: 10.3390/cancers15133458 -
Proceedings of the National Academy of... Aug 2023Dysregulation of histone lysine methyltransferases and demethylases is one of the major mechanisms driving the epigenetic reprogramming of transcriptional networks in...
Dysregulation of histone lysine methyltransferases and demethylases is one of the major mechanisms driving the epigenetic reprogramming of transcriptional networks in castration-resistant prostate cancer (CRPC). In addition to their canonical histone targets, some of these factors can modify critical transcription factors, further impacting oncogenic transcription programs. Our recent report demonstrated that LSD1 can demethylate the lysine 270 of FOXA1 in prostate cancer (PCa) cells, leading to the stabilization of FOXA1 chromatin binding. This process enhances the activities of the androgen receptor and other transcription factors that rely on FOXA1 as a pioneer factor. However, the identity of the methyltransferase responsible for FOXA1 methylation and negative regulation of the FOXA1-LSD1 oncogenic axis remains unknown. SETD7 was initially identified as a transcriptional activator through its methylation of histone 3 lysine 4, but its function as a methyltransferase on nonhistone substrates remains poorly understood, particularly in the context of PCa progression. In this study, we reveal that SETD7 primarily acts as a transcriptional repressor in CRPC cells by functioning as the major methyltransferase targeting FOXA1-K270. This methylation disrupts FOXA1-mediated transcription. Consistent with its molecular function, we found that SETD7 confers tumor suppressor activity in PCa cells. Moreover, loss of SETD7 expression is significantly associated with PCa progression and tumor aggressiveness. Overall, our study provides mechanistic insights into the tumor-suppressive and transcriptional repression activities of SETD7 in mediating PCa progression and therapy resistance.
Topics: Male; Humans; Histones; Prostatic Neoplasms, Castration-Resistant; Lysine; Receptors, Androgen; Methyltransferases; Histone Demethylases; Cell Line, Tumor; Gene Expression Regulation, Neoplastic; Histone-Lysine N-Methyltransferase; Hepatocyte Nuclear Factor 3-alpha
PubMed: 37549269
DOI: 10.1073/pnas.2220472120 -
IScience Oct 2023HS3ST3B1-IT1 was identified as a downregulated long noncoding RNA in osteoarthritic cartilage. However, its roles and mechanisms in the pathogenesis of osteoarthritis...
HS3ST3B1-IT1 was identified as a downregulated long noncoding RNA in osteoarthritic cartilage. However, its roles and mechanisms in the pathogenesis of osteoarthritis (OA) are unclear. In this study, we demonstrated that the expressions of HS3ST3B1-IT1 and its maternal gene HS3ST3B1 were downregulated and positively correlated in osteoarthritic cartilage. Overexpression of HS3ST3B1-IT1 significantly increased chondrocyte viability, inhibited chondrocyte apoptosis, and upregulated extracellular matrix (ECM) proteins, whereas HS3ST3B1-IT1 knockdown had the opposite effects. In addition, HS3ST3B1-IT1 significantly ameliorated monosodium-iodoacetate-induced OA . Mechanistically, HS3ST3B1-IT1 upregulated HS3ST3B1 expression by blocking its ubiquitination-mediated degradation. Knockdown of HS3ST3B1 reversed the effects of HS3ST3B1-IT1 on chondrocyte viability, apoptosis, and ECM metabolism. AlkB homolog 5 (ALKBH5)-mediated N-methyladenosine (mA) demethylation stabilized HS3ST3B1-IT1 RNA. Together, our data revealed that ALKBH5-mediated upregulation of HS3ST3B1-IT1 suppressed OA progression by elevating HS3ST3B1 expression, suggesting that HS3ST3B1-IT1/HS3ST3B1 may serve as potential therapeutic targets for OA treatment.
PubMed: 37752950
DOI: 10.1016/j.isci.2023.107838 -
Current Opinion in Structural Biology Dec 2023Histone methylation, one of the most common histone modifications, has fundamental roles in regulating chromatin-based processes. Jumonji histone lysine demethylases... (Review)
Review
Histone methylation, one of the most common histone modifications, has fundamental roles in regulating chromatin-based processes. Jumonji histone lysine demethylases (JMJC KDMs) influence regulation of gene transcription through both their demethylation and chromatin scaffolding functions. It has recently been demonstrated that dysregulation of JMJC KDMs contributes to pathogenesis and progression of several diseases, including cancer. These observations have led to an increased interest in modulation of enzymes that regulate lysine methylation. Here, we highlight recent progress in understanding catalysis of JMJC KDMs. Specifically, we focus on recent research advances on elucidation of JMJC KDM substrate recognition and interactomes. We also highlight recently reported JMJC KDM inhibitors and describe their therapeutic potentials and challenges. Finally, we discuss alternative strategies to target these enzymes, which rely on targeting JMJC KDMs accessory domains as well as utilization of the targeted protein degradation strategy.
Topics: Histone Demethylases; Histones; Jumonji Domain-Containing Histone Demethylases; Catalysis; Chromatin
PubMed: 37832177
DOI: 10.1016/j.sbi.2023.102707 -
Nucleic Acids Research Jul 2023Iron metabolism is closely associated with the pathogenesis of obesity. However, the mechanism of the iron-dependent regulation of adipocyte differentiation remains...
Iron metabolism is closely associated with the pathogenesis of obesity. However, the mechanism of the iron-dependent regulation of adipocyte differentiation remains unclear. Here, we show that iron is essential for rewriting of epigenetic marks during adipocyte differentiation. Iron supply through lysosome-mediated ferritinophagy was found to be crucial during the early stage of adipocyte differentiation, and iron deficiency during this period suppressed subsequent terminal differentiation. This was associated with demethylation of both repressive histone marks and DNA in the genomic regions of adipocyte differentiation-associated genes, including Pparg, which encodes PPARγ, the master regulator of adipocyte differentiation. In addition, we identified several epigenetic demethylases to be responsible for iron-dependent adipocyte differentiation, with the histone demethylase jumonji domain-containing 1A and the DNA demethylase ten-eleven translocation 2 as the major enzymes. The interrelationship between repressive histone marks and DNA methylation was indicated by an integrated genome-wide association analysis, and was also supported by the findings that both histone and DNA demethylation were suppressed by either the inhibition of lysosomal ferritin flux or the knockdown of iron chaperone poly(rC)-binding protein 2. In summary, epigenetic regulations through iron-dependent control of epigenetic enzyme activities play an important role in the organized gene expression mechanisms of adipogenesis.
Topics: Iron; Genome-Wide Association Study; DNA Methylation; Epigenesis, Genetic; Adipocytes; Jumonji Domain-Containing Histone Demethylases
PubMed: 37158274
DOI: 10.1093/nar/gkad342 -
Communications Biology Dec 2023N-methyladenosine (mA) plays a crucial role in the development and functional homeostasis of the central nervous system. The fat mass and obesity-associated (FTO) gene,...
N-methyladenosine (mA) plays a crucial role in the development and functional homeostasis of the central nervous system. The fat mass and obesity-associated (FTO) gene, which is highly expressed in the hypothalamus, is closely related to female pubertal development. In this study, we found that mA methylation decreased in the hypothalamus gradually with puberty and decreased in female rats with precocious puberty. FTO expression was increased at the same time. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) showed that the mA methylation of PLCβ, a key enzyme of the Ca signalling pathway, was decreased significantly in the hypothalamus in precocious rats. Upregulating FTO increased PLCβ3 expression and activated the Ca signalling pathway, which promoted GnRH expression. Dual-luciferase reporter and MeRIP-qPCR assays confirmed that FTO regulated mA demethylation of PLCβ and promoted PLCβ expression. Upon overexpressing FTO in the hypothalamic arcuate nucleus (ARC) in female rats, we observed advanced puberty onset. Meanwhile, PLCβ and GnRH expression in the hypothalamus increased significantly, and the Ca signalling pathway was activated. Our study demonstrates that FTO enhances GnRH expression, which promotes puberty onset, by regulating mA demethylation of PLCβ3 and activating the Ca signalling pathway.
Topics: Animals; Female; Rats; Demethylation; Gonadotropin-Releasing Hormone; Hypothalamus; Methylation; Signal Transduction
PubMed: 38129517
DOI: 10.1038/s42003-023-05677-2 -
Cell Reports Oct 2023Maintaining healthy adipose tissue is crucial for metabolic health, requiring a deeper understanding of adipocyte development and response to high-calorie diets. This...
Maintaining healthy adipose tissue is crucial for metabolic health, requiring a deeper understanding of adipocyte development and response to high-calorie diets. This study highlights the importance of TET3 during white adipose tissue (WAT) development and expansion. Selective depletion of Tet3 in adipose precursor cells (APCs) reduces adipogenesis, protects against diet-induced adipose expansion, and enhances whole-body metabolism. Transcriptomic analysis of wild-type and Tet3 knockout (KO) APCs unveiled TET3 target genes, including Pparg and several genes linked to the extracellular matrix, pivotal for adipogenesis and remodeling. DNA methylation profiling and functional studies underscore the importance of DNA demethylation in gene regulation. Remarkably, targeted DNA demethylation at the Pparg promoter restored its transcription. In conclusion, TET3 significantly governs adipogenesis and diet-induced adipose expansion by regulating key target genes in APCs.
Topics: Animals; Humans; Mice; Adipocytes; Adipogenesis; Adipose Tissue; Adipose Tissue, White; Cell Differentiation; Diet; Dioxygenases; Obesity; PPAR gamma
PubMed: 37777963
DOI: 10.1016/j.celrep.2023.113196 -
Frontiers in Molecular Biosciences 2023Regulatory T cells (Tregs) adoptive immunotherapy is emerging as a viable treatment option for both autoimmune and alloimmune diseases. However, numerous challenges... (Review)
Review
Regulatory T cells (Tregs) adoptive immunotherapy is emerging as a viable treatment option for both autoimmune and alloimmune diseases. However, numerous challenges remain, including limitations related to cell number, availability of target-specific cells, stability, purity, homing ability, and safety concerns. To address these challenges, cell engineering strategies have emerged as promising solutions. Indeed, it has become feasible to increase Treg numbers or enhance their stability through Foxp3 overexpression, post-translational modifications, or demethylation of the Treg-specific demethylated region (TSDR). Specificity can be engineered by the addition of chimeric antigen receptors (CARs), with new techniques designed to fine-tune specificity (tandem chimeric antigen receptors, universal chimeric antigen receptors, synNotch chimeric antigen receptors). The introduction of B-cell targeting antibody receptor (BAR) Tregs has paved the way for effective regulation of B cells and plasma cells. In addition, other constructs have emerged to enhance Tregs activation and function, such as optimized chimeric antigen receptors constructs and the use of armour proteins. Chimeric antigen receptor expression can also be better regulated to limit tonic signaling. Furthermore, various opportunities exist for enhancing the homing capabilities of CAR-Tregs to improve therapy outcomes. Many of these genetic modifications have already been explored for conventional CAR-T therapy but need to be further considered for CAR-Tregs therapies. This review highlights innovative CAR-engineering strategies that have the potential to precisely and efficiently manage immune responses in autoimmune diseases and improve transplant outcomes. As these strategies are further explored and optimized, CAR-Treg therapies may emerge as powerful tools for immune intervention.
PubMed: 37900916
DOI: 10.3389/fmolb.2023.1267762