The histone methyltransferase SETD2 modulates oxidative stress to attenuate experimental colitis

Recent advances in targeting histone H3 lysine 36 methyltransferases for cancer therapy

Histone H3 lysine 36 (H3K36) methylation is a typical epigenetic histone modification that is involved in various biological processes such as DNA transcription, repair and recombination in vivo. Mutations, translocations, and aberrant gene expression associated with H3K36 methyltransferases have been implicated in different malignancies such as acute myeloid leukemia, lung cancer, multiple myeloma, and others. Herein, we provided a comprehensive overview of the latest advances in small molecule inhibitors targeting H3K36 methyltransferases. We analyzed the structures and biological functions of the H3K36 methyltransferases family members. Additionally, we discussed the potential directions for future development of inhibitors targeting H3K36 methyltransferases.

SPA inhibits hBMSC osteogenic differentiation and M1 macrophage polarization by suppressing SETD2 in acute suppurative osteomyelitis

To clarify the impact of SETD2 on macrophage function in pediatric patients with acute suppurative osteomyelitis and to elucidate the precise underlying mechanism. To gain insights into the potential functions of SETD2, a comprehensive study was conducted utilizing a co-culture model of human bone mesenchymal stem cells (hBMSCs) and bone marrow-derived macrophages (THP-1). A range of techniques were employed, including quantitative polymerase chain reaction, western blotting, ELISA, alkaline phosphatase activity assays, alizarin red S staining, luciferase reporter gene assays, and chromatin immunoprecipitation, to unravel the intricate interactions and molecular mechanisms involving SETD2 in this system. It was observed that SETD2 expression was reduced in THP-1 cells stimulated by staphylococcal protein A (SPA). Furthermore, the downregulation of SETD2 resulted in elevated M1 macrophage polarization and glycolysis, effects that were mitigated by SPA stimulation. Notably, SPA-stimulated THP-1 cells exhibited an increase in HIF-1α expression, which exhibited an inverse correlation with SETD2 levels. Moreover, it was discovered that SETD2 functioned as a catalyst for H3K36me3 and bound to the HIF-1α gene, which, in turn, regulated HIF-1α expression. Furthermore, the suppression of HIF-1α abrogated the consequences of SETD2 downregulation on glycolysis and M1 macrophage polarization. Lastly, the study demonstrated that M1 macrophage polarization serves as a mediator for BMP4's inhibitory effect on osteogenic differentiation of hBMSCs. This research has uncovered a previously unknown role of SETD2 in macrophages during osteomyelitis, revealing its significance in the pathogenesis of this condition. These findings suggest SETD2 as a novel target for the treatment of osteomyelitis.

Controllers of histone methylation-modifying enzymes in gastrointestinal cancers

Gastrointestinal (GI) cancers have been considered primarily genetic malignancies, caused by a series of progressive genetic alterations. Accumulating evidence shows that histone methylation, an epigenetic modification program, plays an essential role in the different pathological stages of GI cancer progression, such as precancerous lesions, tumorigenesis, and tumor metastasis. Histone methylation-modifying enzymes, including histone methyltransferases (HMTs) and demethylases (HDMs), are the main executor of post-transcriptional modification. The abnormal expression of histone methylation-modifying enzymes characterizes GI cancers with complex pathogenesis and progression. Interactions between upstream controllers and histone methylation-modifying enzymes have recently been revealed, and have provided numerous opportunities to elucidate the pathogenesis of GI cancers in depth and clearly. Here we focus on the association between histone methylation-modifying enzymes and their controllers, aiming to provide a new perspective on the molecular research and clinical management of GI cancers.

Plant-derived vesicle-like nanoparticles: A new tool for inflammatory bowel disease and colitis-associated cancer treatment

Long-term use of conventional drugs to treat inflammatory bowel diseases (IBD) and colitis-associated cancer (CAC) has an adverse impact on the human immune system and easily leads to drug resistance, highlighting the urgent need to develop novel biotherapeutic tools with improved activity and limited side effects. Numerous products derived from plant sources have been shown to exert antibacterial, anti-inflammatory and antioxidative stress effects. Plant-derived vesicle-like nanoparticles (PDVLNs) are natural nanocarriers containing lipids, protein, DNA and microRNA (miRNA) with the ability to enter mammalian cells and regulate cellular activity. PDVLNs have significant potential in immunomodulation of macrophages, along with regulation of intestinal microorganisms and friendly antioxidant activity, as well as overcoming drug resistance. PDVLNs have utility as effective drug carriers and potential modification, with improved drug stability. Since immune function, intestinal microorganisms, and antioxidative stress are commonly targeted key phenomena in the treatment of IBD and CAC, PDVLNs offer a novel therapeutic tool. This review provides a summary of the latest advances in research on the sources and extraction methods, applications and mechanisms in IBD and CAC therapy, overcoming drug resistance, safety, stability, and clinical application of PDVLNs. Furthermore, the challenges and prospects of PDVLN-based treatment of IBD and CAC are systematically discussed.

Methyltransferase Setd2 prevents T cell-mediated autoimmune diseases via phospholipid remodeling

Coordinated metabolic reprogramming and epigenetic remodeling are critical for modulating T cell function and differentiation. However, how the epigenetic modification controls Th17/Treg cell balance via metabolic reprogramming remains obscure. Here, we find that Setd2, a histone H3K36 trimethyltransferase, suppresses Th17 development but promotes iTreg cell polarization via phospholipid remodeling. Mechanistically, Setd2 up-regulates transcriptional expression of lysophosphatidylcholine acyltransferase 4 (Lpcat4) via directly catalyzing H3K36me3 of Lpcat4 gene promoter in T cells. Lpcat4-mediated phosphatidylcholine PC(16:0,18:2) generation in turn limits endoplasmic reticulum stress and oxidative stress. These changes decrease HIF-1α transcriptional activity and thus suppress Th17 but enhance Treg development. Consistent with this regulatory paradigm, T cell deficiency of Setd2 aggravates neuroinflammation and demyelination in experimental autoimmune encephalomyelitis due to imbalanced Th17/Treg cell differentiation. Overall, our data reveal that Setd2 acts as an epigenetic brake for T cell-mediated autoimmunity through phospholipid remodeling, suggesting potential targets for treating neuroinflammatory diseases.

Setd2 deficiency promotes gastric tumorigenesis through inhibiting the SIRT1/FOXO pathway

Gastric cancer (GC) is the fifth most common cancer and the second leading cause of cancer death globally. SETD2 is a histone methyltransferase catalyzing tri-methylation of H3K36 (H3K36me3) and has been shown to participate in diverse biological processes and human tumors. However, the mechanism of SETD2 in GC remains unclear. Here, we reported that Setd2 deficiency predicts poor prognosis of gastric cancer. SETD2 loss facilitated H. felis/MNU and c-Myc-induced gastric tumorigenesis, respectively. The mouse model of stomach-specific Setd2 depletion together with c-MYC overexpression (AMS) developed high-grade epithelial defects, intestinal metaplasia and dysplasia at only 10-12 weeks of age. Mechanistically, Setd2 depletion resulted in impaired epigenetic regulation of Sirt1, thus inhibiting the SIRT1/FOXO pathway. Moreover, the agonists of FOXO signaling or overexpression of SIRT1 significantly rescued the enhanced cell proliferation and migration caused by Setd2 deficiency in SGC7901 cells. Together, our findings highlight an epigenetic mechanism by which SETD2 regulates gastric tumorigenesis through SIRT1/FOXO pathway. It may also pave the way for the development of targeted, patient-tailored therapies for GC patients with Setd2 deficiency.

Loss of SETD2 aggravates colorectal cancer progression caused by SMAD4 deletion through the RAS/ERK signalling pathway

BACKGOUND

Colorectal cancer (CRC) is a complex, multistep disease that arises from the interplay genetic mutations and epigenetic alterations. The histone H3K36 trimethyltransferase SET domain-containing 2 (SETD2), as an epigenetic signalling molecule, has a 5% mutation rate in CRC. SETD2 expression is decreased in the development of human CRC and mice treated with Azoxymethane /Dextran sodium sulfate (AOM/DSS). Loss of SETD2 promoted CRC development. SMAD Family member 4 (SMAD4) has a 14% mutation rate in CRC, and SMAD4 ablation leads to CRC. The co-mutation of SETD2 and SMAD4 predicted advanced CRC. However, little is known on the potential synergistic effect of SETD2 and SMAD4.

METHODS

CRC tissues from mice and SW620 cells were used as research subjects. Clinical databases of CRC patients were analyzed to investigate the association between SETD2 and SMAD4. SETD2 and SMAD4 double-knockout mice were established to further investigate the role of SETD2 in SMAD4-deficient CRC. The intestinal epithelial cells (IECs) were isolated for RNA sequencing and chromatin immunoprecipitation sequencing (ChIP-seq) to explore the mechanism and the key molecules resulting in CRC. Molecular and cellular experiments were conducted to analyze the role of SETD2 in SMAD4-deficient CRC. Finally, rescue experiments were performed to confirm the molecular mechanism of SETD2 in the development of SMAD4-dificient CRC.

RESULTS

The deletion of SETD2 promotes the malignant progression of SMAD4-deficient CRC. Smad4Vil-KO ; Setd2Vil-KO mice developed a more severe CRC phenotype after AOM/DSS induction, with a larger tumour size and a more vigorous epithelial proliferation rate. Further mechanistic findings revealed that the loss of SETD2 resulted in the down-regulation of DUSP7, which is involved in the inhibition of the RAS/ERK signalling pathway. Finally, the ERK1/2 inhibitor SCH772984 significantly attenuated the progression of CRC in Smad4Vil-KO ;Setd2Vil-KO mice, and overexpression of DUSP7 significantly inhibited the proliferation rates of SETD2KO ; SMAD4KO SW620 cells.

CONCLUSIONS

Our results demonstrated that SETD2 inhibits the RAS/ERK signaling pathway by facilitating the transcription of DUSP7 in SMAD4-deficient CRC, which could provide a potential therapeutic target for the treatment of advanced CRC.

Vitamin B12 is a limiting factor for induced cellular plasticity and tissue repair

Transient reprogramming by the expression of OCT4, SOX2, KLF4 and MYC (OSKM) is a therapeutic strategy for tissue regeneration and rejuvenation, but little is known about its metabolic requirements. Here we show that OSKM reprogramming in mice causes a global depletion of vitamin B12 and molecular hallmarks of methionine starvation. Supplementation with vitamin B12 increases the efficiency of reprogramming both in mice and in cultured cells, the latter indicating a cell-intrinsic effect. We show that the epigenetic mark H3K36me3, which prevents illegitimate initiation of transcription outside promoters (cryptic transcription), is sensitive to vitamin B12 levels, providing evidence for a link between B12 levels, H3K36 methylation, transcriptional fidelity and efficient reprogramming. Vitamin B12 supplementation also accelerates tissue repair in a model of ulcerative colitis. We conclude that vitamin B12, through its key role in one-carbon metabolism and epigenetic dynamics, improves the efficiency of in vivo reprogramming and tissue repair.

SETD2 deficiency promotes renal fibrosis through the TGF-β/Smad signalling pathway in the absence of VHL

BACKGROUND

Renal fibrosis is the final development pathway and the most common pathological manifestation of chronic kidney disease. Epigenetic alteration is a significant intrinsic factor contributing to the development of renal fibrosis. SET domain-containing 2 (SETD2) is the sole histone H3K36 trimethyltransferase, catalysing H3K36 trimethylation. There is evidence that SETD2-mediated epigenetic alterations are implicated in many diseases. However, it is unclear what role SETD2 plays in the development of renal fibrosis.

METHODS

Kidney tissues from mice as well as HK2 cells were used as research subjects. Clinical databases of patients with renal fibrosis were analysed to investigate whether SETD2 expression is reduced in the occurrence of renal fibrosis. SETD2 and Von Hippel-Lindau (VHL) double-knockout mice were used to further investigate the role of SETD2 in renal fibrosis. Renal tubular epithelial cells isolated from mice were used for RNA sequencing and chromatin immunoprecipitation sequencing to search for molecular signalling pathways and key molecules leading to renal fibrosis in mice. Molecular and cell biology experiments were conducted to analyse and validate the role of SETD2 in the development of renal fibrosis. Finally, rescue experiments were performed to determine the molecular mechanism of SETD2 deficiency in the development of renal fibrosis.

RESULTS

SETD2 deficiency leads to severe renal fibrosis in VHL-deficient mice. Mechanically, SETD2 maintains the transcriptional level of Smad7, a negative feedback factor of the transforming growth factor-β (TGF-β)/Smad signalling pathway, thereby preventing the activation of the TGF-β/Smad signalling pathway. Deletion of SETD2 leads to reduced Smad7 expression, which results in activation of the TGF-β/Smad signalling pathway and ultimately renal fibrosis in the absence of VHL.

CONCLUSIONS

Our findings reveal the role of SETD2-mediated H3K36me3 of Smad7 in regulating the TGF-β/Smad signalling pathway in renal fibrogenesis and provide an innovative insight into SETD2 as a potential therapeutic target for the treatment of renal fibrosis.

Identification of 6 cuproptosis-related genes for active ulcerative colitis with both diagnostic and therapeutic values

Cuproptosis has been reported to affect a variety of diseases. Therefore, we aimed to examine the role of cuproptosis-related genes in active ulcerative colitis (UC). We acquired 2 datasets of active UC from the Gene Expression Omnibus database and created immune cell infiltrations to research immune cell dysregulation. Based on the cuproptosis gene set and differentially expressed genes (DEGs), we identified the differentially expressed genes of cuproptosis (CuDEGs). We then used 2 machine learning methods to screen hub CuDEGs. Subsequently, we performed validation on additional datasets and investigated the relationship between hub CuDEGs and drug treatments. Thirty-five controls with inactive UC and 90 patients with active UC were obtained from the training sets. A total of 9157 DEGs and 27 CuDEGs were identified, respectively. Immune cell infiltration analysis revealed that patients with active UC exhibited higher levels of activated dendritic cells and neutrophils as well as lower levels of CD8+ T cells, regulatory T cells (Tregs), and macrophage M2. A six-gene cuproptosis signature was identified using machine learning algorithms. We further validated that the 6 hub CuDEGs showed a strong correlation with active UC and acted as cuproptosis-related biomarkers of active UC. Moreover, the expression of ATOX1 was downregulated, and SUMF1, MT1G, ATP7B, FDX1, and LIAS expression was upregulated in the colonic mucosa of active UC patients who responded to golimumab or vedolizumab therapy. With the exception of ATP7B, the expression patterns of hub CuDEGs before and after infliximab treatment of patients with active UC were similar to those of golimumab and vedolizumab. Cuproptosis and active UC have a complex relationship, as illustrated in our study. ATOX1, SUMF1, MT1G, ATP7B, FDX1, and LIAS are cuproptosis-related hub genes of active UC. Our study opens new avenues for investigating UC progression and developing novel therapeutic potential targets for the disease.

Colitis-associated carcinogenesis: crosstalk between tumors, immune cells and gut microbiota

Colorectal cancer (CRC) is the third most common cancer worldwide. One of the main causes of colorectal cancer is inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD). Intestinal epithelial cells (IECs), intestinal mesenchymal cells (IMCs), immune cells, and gut microbiota construct the main body of the colon and maintain colon homeostasis. In the development of colitis and colitis-associated carcinogenesis, the damage, disorder or excessive recruitment of different cells such as IECs, IMCs, immune cells and intestinal microbiota play different roles during these processes. This review aims to discuss the various roles of different cells and the crosstalk of these cells in transforming intestinal inflammation to cancer, which provides new therapeutic methods for chemotherapy, targeted therapy, immunotherapy and microbial therapy.

Role of glycolysis in inflammatory bowel disease and its associated colorectal cancer

Inflammatory bowel disease (IBD) has been referred to as the "green cancer," and its progression to colorectal cancer (CRC) poses a significant challenge for the medical community. A common factor in their development is glycolysis, a crucial metabolic mechanism of living organisms, which is also involved in other diseases. In IBD, glycolysis affects gastrointestinal components such as the intestinal microbiota, mucosal barrier function, and the immune system, including macrophages, dendritic cells, T cells, and neutrophils, while in CRC, it is linked to various pathways, such as phosphatidylinositol-3-kinase (PI3K)/AKT, AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), and transcription factors such as p53, Hypoxia-inducible factor (HIF), and c-Myc. Thus, a comprehensive study of glycolysis is essential for a better understanding of the pathogenesis and therapeutic targets of both IBD and CRC. This paper reviews the role of glycolysis in diseases, particularly IBD and CRC, via its effects on the intestinal microbiota, immunity, barrier integrity, signaling pathways, transcription factors and some therapeutic strategies targeting glycolytic enzymes.

Histone methyltransferase SETD2 inhibits M1 macrophage polarization and glycolysis by suppressing HIF-1α in sepsis-induced acute lung injury

Sepsis is a severe syndrome caused by the imbalance of the host response to infection, accompanied by multiple organ damage, especially acute lung injury. SET Domain-Containing 2 (SETD2) is a methyltransferase catalyzing H3 lysine 36 trimethylation (H3K36me3) that regulates multiple biological processes. This study focused on explicating the action of SETD2 on macrophage function in sepsis and the precise mechanism involved. Enzyme-linked immunosorbent assay, real-time quantitative polymerase chain reaction (RT-qPCR), and Western blotting were used to determine expression. Luciferase reporter assay and chromatin immunoprecipitation assay were conducted to detect the binding of SETD2 or H3K36me3 with the hypoxia-inducible factor 1, alpha subunit (Hif1a) gene. A sepsis-induced acute lung injury model was constructed via cecal ligation and puncture (CLP). SETD2 was decreased in RAW 264.7 cells stimulated by lipopolysaccharide (LPS). Besides, SETD2 suppressed M1 macrophage polarization and glycolysis caused by LPS. HIF-1α was enhanced in RAW 264.7 cells stimulated by LPS and inversely related to SETD2 expression. In addition, SETD2-catalyzed H3K36me3 bound to the Hif1a gene to modulate HIF-1α expression. Furthermore, Hif1a silencing suppressed Setd2 silencing-induced M1 macrophage polarization and glycolysis in RAW 264.7 cells. Moreover, overexpression of Setd2 inhibited CLP-induced lung injury and M1 macrophage polarization in mice. SETD2 suppressed M1 macrophage polarization and glycolysis via regulating HIF-1α through catalyzing H3K36me3 in sepsis.

Metabolic transcriptomics dictate responses of cone photoreceptors to retinitis pigmentosa

Most mutations in retinitis pigmentosa (RP) arise in rod photoreceptors, but cone photoreceptors, responsible for high-resolution daylight and color vision, are subsequently affected, causing the most debilitating features of the disease. We used mass spectroscopy to follow 13C metabolites delivered to the outer retina and single-cell RNA sequencing to assess photoreceptor transcriptomes. The S cone metabolic transcriptome suggests engagement of the TCA cycle and ongoing response to ROS characteristic of oxidative phosphorylation, which we link to their histone modification transcriptome. Tumor necrosis factor (TNF) and its downstream effector RIP3, which drive ROS generation via mitochondrial dysfunction, are induced and activated as S cones undergo early apoptosis in RP. The long/medium-wavelength (L/M) cone transcriptome shows enhanced glycolytic capacity, which maintains their function as RP progresses. Then, as extracellular glucose eventually diminishes, L/M cones are sustained in long-term dormancy by lactate metabolism.

Knockdown of SETD2 promotes erastin-induced ferroptosis in ccRCC

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer and is associated with poor prognosis. The histone H3 lysine 36 methyltransferase SET-domain-containing 2 (SETD2) has been reported to be expressed at low levels and frequently mutated in ccRCC. Ferroptosis, a form of death distinct from apoptosis and necrosis, has been reported in recent years in renal cancer. However, the relationship between SETD2 and ferroptosis in renal cancer is not clear. Here, we demonstrated that SETD2 was expressed at low levels in ccRCC and was associated with poor prognosis. Moreover, we found that knockdown of SETD2 increased lipid peroxidation and Fe2+ levels in tumor cells, thereby increasing the sensitivity of erastin, a ferroptosis inducer. Mechanistically, histone H3 lysine 36 trimethylation (H3K36me3) which was catalyzed by SETD2, interacted with the promoter of ferrochelatase (FECH) to regulate its transcription and ferroptosis-related signaling pathways. In conclusion, the presesnt study revealed that knockdown of the epigenetic molecule, SETD2, significantly increases the sensitivity of ferroptosis inducers which promotes tumor cell death, thereby indicating that SETD2 may be a potential therapeutic target for ccRCC.

miR-200a attenuated oxidative stress, inflammation, and apoptosis in dextran sulfate sodium-induced colitis through activation of Nrf2

Introduction

Oxidative stress and inflammatory responses are critical factors in ulcerative colitis disease pathogenesis. Nuclear factor erythroid 2-related factor 2 (Nrf2) modulates oxidative stress and suppresses inflammatory responses, and the protective benefits of Nrf2 activation have been associated with the therapy of ulcerative colitis. MicroRNA-200a (miR-200a) could target Kelch-like ECH-associated protein 1 (Keap1) and activate the Nrf2-regulated antioxidant pathway. Nevertheless, whether miR-200a modulates the Keap1/Nrf2 pathway in dextran sulfate sodium (DSS)-induced colonic damage is unknown. Here, our research intends to examine the impact of miR-200a in the model of DSS-induced colitis.

Methods

Prior to DSS intervention, we overexpressed miR-200a in mice for four weeks using an adeno-associated viral (AAV) vector to address this problem. ELISA detected the concentration of inflammation-related cytokines. The genes involved in inflammatory reactions and oxidative stress were identified using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blot, and immunofluorescence. Moreover, we applied siRNAs to weakened Nrf2 expression to confirm the hypothesis that miR-200a provided protection via Nrf2.

Results

The present study discovered miR-200a down-regulation, excessive inflammatory activation, enterocyte apoptosis, colonic dysfunction, and Keap1/Nrf2 antioxidant pathway inactivation in mouse colitis and NCM460 cells under DSS induction. However, our data demonstrated that miR-200a overexpression represses Keap1 and activates the Nrf2 antioxidant pathway, thereby alleviating these adverse alterations in animal and cellular models. Significantly, following Nrf2 deficiency, we failed to observe the protective benefits of miR-200a against colonic damage.

Discussion

Taken together, through activating the Keap1/Nrf2 signaling pathway, miR-200a protected against DSS-induced colonic damage. These studies offer an innovative therapeutic approach for ulcerative colitis.

SETD2-H3K36ME3: an important bridge between the environment and tumors

Epigenetic regulation plays an important role in the occurrence, development and treatment of tumors. The histone methyltransferase SET-domain-containing 2 (SETD2) plays a key role in mammalian epigenetic regulation by catalyzing histone methylation and interacting with RNA polymerase II to mediate transcription elongation and mismatch repair. As an important bridge between the environment and tumors, SETD2-H3K36me3 plays an important role in the occurrence and development of tumors. Many tumors, including renal cancer, gastric cancer, lung cancer, are closely related to SETD2 gene mutations. As a key component of common tumor suppressor mechanisms, SETD2-H3K36me3is an important target for clinical disease diagnosis and treatment. Here, we reviewed the structure and function of the SETD2 and how SETD2-H3K36me3 functions as a bridge between the environment and tumors to provide an in-depth understanding of its role in the occurrence and development of various tumors, which is of great significance for future disease diagnosis and treatment.

Inhibition of Histone H3K18 Acetylation-Dependent Antioxidant Pathways Involved in Arsenic-Induced Liver Injury in Rats and the Protective Effect of Rosa roxburghii Tratt Juice

Arsenic is a common environmental toxicant. Long-term arsenic exposure can induce various types of liver injury, but the underlying mechanism remains unclear, so effective prevention and treatment measures are unknown. This study aims to explore the mechanism of arsenic-induced rat liver injury based on the histone H3K18 acetylation-dependent antioxidant pathway and to identify the role of a medicinal and edible resource, Rosa roxburghii Tratt juice, in combating it. Hepatic steatosis and inflammatory cell infiltration were observed in rats exposed to different doses of NaAsO₂ using histopathological measurement. Increased 8-OHdG and MDA in liver tissue corroborated hepatic oxidative damage. We further found that a reduction in H3K18ac in the liver showed a dose-response relationship, with an increase in the NaAsO₂ treatment dose, and it was remarkably associated with increased 8-OHdG and MDA. The results of ChIP-qPCR identified that the decreased enrichment of H3K18ac in promoters of the Hspa1a and Hspb8 genes culminated in the inhibition of the genes' expression, which was found to be involved in the aggravation of hepatic oxidative damage induced by arsenic. Notably, Rosa roxburghii Tratt juice was found to reduce 8-OHdG and MDA in the liver, thereby alleviating the histopathological lesions induced by arsenic, which was modulated by recovering the H3K18ac-dependent transcriptional activation of the Hspa1a and Hspb8 genes. Taken together, we provide a novel epigenetics insight into clarifying the mechanism of arsenic-induced liver injury and its rescue by Rosa roxburghii Tratt juice.

Epigenotoxicity: a danger to the future life

Environmental toxicants can regulate gene expression in the absence of DNA mutations via epigenetic mechanisms such as DNA methylation, histone modifications, and non-coding RNAs' (ncRNAs). Here, all three epigenetic modifications for seven important categories of diseases and the impact of eleven main environmental factors on epigenetic modifications were discussed. Epigenetic-related mechanisms are among the factors that could explain the root cause of a wide range of common diseases. Its overall impression on the development of diseases can help us diagnose and treat diseases, and besides, predict transgenerational and intergenerational effects. This comprehensive article attempted to address the relationship between environmental factors and epigenetic modifications that cause diseases in different categories. The studies main gap is that the precise role of environmentally-induced epigenetic alterations in the etiology of the disorders is unknown; thus, still more well-designed researches need to be accomplished to fill this gap. The present review aimed to first summarize the adverse effect of certain chemicals on the epigenome that may involve in the onset of particular disease based on in vitro and in vivo models. Subsequently, the possible adverse epigenetic changes that can lead to many human diseases were discussed.

Clinical and histopathologic characterization of SETD2-mutated colorectal cancer

With the advent of next-generation sequencing (NGS), identifying and better understanding genetic mutations in cancer pathways has become more feasible. A mutation now commonly reported in NGS panels is the SETD2 gene (H3K36 trimethyltransferase). However, its contributions to colorectal cancer (CRC) are not well described. In this study, we describe the clinicopathologic characteristics of SETD2-mutated CRC, determine common mutation sites on the SETD2 gene, and correlate these mutations with the loss of H3K36 trimethylation and the aberrant expression of beta-catenin. By searching pathology reports at our institution which included the 161-gene NGS panel from 2019 to 2021, we identify 24 individuals with SETD2-mutated CRC. All samples were evaluated for microsatellite status, H3K36 trimethylation, and beta-catenin via immunohistochemistry. In this cohort of 24 SETD2-mutated CRC individuals (a median age of 62.4 years [interquartile range: 49.1-73.6]), 10 (41.7%) patients presented at American Joint Committee on Cancer (AJCC) tumor stage II, seven (29.2%) at stage III, six (25%) at stage IV, and one (4.2%) at stage I. Most tumors studied were adenocarcinomas with no further specification (22, 92%), and most tumors were microsatellite stable (18, 82.5%). Thirty-three mutation locations were represented by 24 patients, with one patient having six mutations in the SETD2 gene and two patients having three mutations. The dominant mutation type is missense mutations (N = 29, 87.9%), and no mutation hotspots were found. Only two samples lost trimethylation of histone H3K36, both from individuals with multiple SETD2 mutations and aberrant nuclear beta-catenin expression. SETD2-mutated CRC is similar in clinical and histologic presentation to other commonly reported CRC. SETD2 mutations were missense dominantand showed no hotspots, and multiple mutations are likely necessary for loss of H3K36 trimethylation. These results warrant further study on determining a role of SETD2-histone H3K36 pathway in CRC.

Setd2 supports GATA3+ST2+ thymic-derived Treg cells and suppresses intestinal inflammation

Treg cells acquire distinct transcriptional properties to suppress specific inflammatory responses. Transcription characteristics of Treg cells are regulated by epigenetic modifications, the mechanism of which remains obscure. Here, we report that Setd2, a histone H3K36 methyltransferase, is important for the survival and suppressive function of Treg cells, especially those from the intestine. Setd2 supports GATA3⁺ST2⁺ intestinal thymic-derived Treg (tTreg) cells by facilitating the expression and reciprocal relationship of GATA3 and ST2 in tTreg cells. IL-33 preferentially boosts Th2 cells rather than GATA3⁺ Treg cells in Foxp3^Cre-YFPSetd2 ^flox/flox mice, corroborating the constraint of Th2 responses by Setd2 expression in Treg cells. SETD2 sustains GATA3 expression in human Treg cells, and SETD2 expression is increased in Treg cells from human colorectal cancer tissues. Epigenetically, Setd2 regulates the transcription of target genes (including Il1rl1) by modulating the activity of promoters and intragenic enhancers where H3K36me3 is typically deposited. Our findings provide mechanistic insights into the regulation of Treg cells and intestinal immunity by Setd2.

Curcumin-Loaded Microspheres Are Effective in Preventing Oxidative Stress and Intestinal Inflammatory Abnormalities in Experimental Ulcerative Colitis in Rats

Curcumin’s role in the treatment of ulcerative colitis (UC) has been proven by numerous studies, but its preventive administration, with the aim of reducing the remission episodes that are characteristic of this disease, must be further investigated. This study investigates the effects of a novel curcumin-loaded polymeric microparticulate oral-drug-delivery system for colon targeting (Col-CUR-MPs) in an experimental model of UC. Male Wistar rats (n = 40) were divided into five groups (n = 8), which were treated daily by oral gavage for seven days with a 2% aqueous solution of carboxymethylcellulose sodium salt (CMCNa) (healthy and disease control), free curcumin powder (reference), Col-CUR-MPs (test) and prednisolone (reference) prior to UC induction by the intrarectal administration of acetic acid (AA), followed by animal sacrification and blood and colonic samples’ collection on the eighth day. Col-CUR-MPs exhibited an important preventive effect in the severity degree of oxidative stress that resulted following AA intrarectal administration, which was proved by the highest catalase (CAT) and total antioxidant capacity (TAC) levels and the lowest nitrites/nitrates (NOx), total oxidative status (TOS) and oxidative stress index (OSI) levels. Biochemical parameter analysis was supported by histopathological assessment, confirming the significant anti-inflammatory and antioxidant effects of this novel colon-specific delivery system in AA-induced rat models of UC. Thus, this study offers encouraging perspectives regarding the preventive administration of curcumin in the form of a drug delivery system for colon targeting.

Setd2 determines distinct properties of intestinal ILC3 subsets to regulate intestinal immunity

Subsets of group 3 innate lymphoid cells (ILC3s) are heterogeneous in development and function and play differential roles in intestinal immunity. Histone modifications are involved in the fate commitment of immune cells, including ILC3s. Here, we report that deletion of Setd2, histone H3K36 methyltransferase, in ILC3s results in increased generation of NKp46⁺ILC3s with enhanced cytotoxic signatures and tumor-suppressive capacity. Meanwhile, Rag1^-/-Rorc^CreSetd2^flox/flox mice have fewer CCR6⁺ILC3s and less defective solitary intestinal lymphoid tissue formation, accompanied by reduced granulocyte-macrophage colony-stimulating factor (GM-CSF) production by NKp46^-ILC3s and decreased CD11b⁺CD103⁺ dendritic cell accumulation. The deficiency of Setd2^-/-NKp46^-ILC3s may contribute to disturbed RORγt⁺Treg homeostasis and intestinal inflammation in Rag1^-/-Rorc^CreSetd2^flox/flox mice upon T cell reconstitution. Setd2 regulates genome accessibility imprinting gene mRNA expression, with a more profound effect on NKp46⁺ILC3s than NKp46^-ILC3s. Therefore, Setd2 determines distinct chromatin status and transcriptomic programs of ILC3 subsets to affect their function and intestinal immunity.

New Insights Into the Epigenetic Regulation of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the colonic mucosa. Environmental factors, genetics, intestinal microbiota, and the immune system are all involved in the pathophysiology of IBD. Lately, accumulating evidence has shown that abnormal epigenetic changes in DNA methylation, histone markers, and non-coding RNA expression greatly contribute to the development of the entire disease. Epigenetics regulates many functions, such as maintaining the homeostasis of the intestinal epithelium and regulating the immune system of the immune cells. In the present study, we systematically summarized the latest advances in epigenetic modification of IBD and how epigenetics reveals new mechanisms of IBD. Our present review provided new insights into the pathophysiology of IBD. Moreover, exploring the patterns of DNA methylation and histone modification through epigenetics can not only be used as biomarkers of IBD but also as a new target for therapeutic intervention in IBD patients.

Loss of Setd2 associates with aberrant microRNA expression and contributes to inflammatory bowel disease progression in mice

Both SETD2-mediated H3K36me3 and miRNAs play critical epigenetic roles in inflammatory bowel disease (IBD) and involve in the dysfunctional intestinal barrier. However, little is known about cross-talk between these two types of regulators in IBD progression. We performed small RNA sequencing of Setd2 epithelium-specific knockout mice (Setd2^Vil-KO) and wild-type controls, both with DSS-induced colitis, and designed a framework for integrative analysis. Firstly, we integrated the downloaded ChIP-seq data with miRNA expression profiles and identified a significant intersection of pre-miRNA expression and H3K36me3 modification. A significant inverse correlation was detected between changes of H3K36me3 modification and expression of the 171 peak-covered miRNAs. We further integrated RNA-seq data with predicted miRNA targets to screen negatively regulated miRNA-mRNA pairs and found the H3K36me3-associated differentially expressed microRNAs significantly enriched in cell-cell junction and signaling pathways. Using network analysis, we identified ten hub miRNAs, among which six are H3K36me3-associated, suggesting therapeutic targets for IBD patients with SETD2-deficiency.