MYND Domain-containing Protein Research Articles

THAP3 recruits SMYD3 to OXPHOS genes and epigenetically promotes mitochondrial respiration in hepatocellular carcinoma.

Mitochondria harbor the oxidative phosphorylation (OXPHOS) system to sustain cellular respiration. However, the transcriptional regulation of OXPHOS remains largely unexplored. Through the cancer genome atlas (TCGA) transcriptome analysis, transcription factor THAP domain-containing 3 (THAP3) was found to be strongly associated with OXPHOS gene expression. Mechanistically, THAP3 recruited the histone methyltransferase SET and MYND domain-containing protein 3 (SMYD3) to upregulate H3K4me3 and promote OXPHOS gene expression. The levels of THAP3 and SMYD3 were altered by metabolic cues. They collaboratively supported liver cancer cell proliferation and colony formation. In clinical human liver cancer, both of them were overexpressed. THAP3 positively correlated with OXPHOS gene expression. Together, THAP3 cooperates with SMYD3 to epigenetically upregulate cellular respiration and liver cancer cell proliferation.

Epigenetic upregulation of MNAT1 by SMYD2 is linked to PI3K/AKT activation and tumorigenesis of pancreatic adenocarcinoma.

Dysregulation of histone methyltransferase SET and MYND domain-containing protein 2 (SMYD2) has been correlated with human developmental disorders and cancers. This research aims to investigate the roles of SMYD2 and its interacted molecules in pancreatic adenocarcinoma (PAAD). Two PAAD-related gene expression datasets were downloaded to screen key molecules involved in tumor progression. SMYD2 was expressed at high levels in PAAD tissues and cells. SMYD2 silencing suppressed while its overexpression promoted proliferation, invasiveness, migration, apoptosis resistance, and cell cycle progression of PAAD cells. Target molecules of SMYD2 were predicted by online tools and validated by chromatin immunoprecipitation and luciferase assays. SMYD2 catalyzed H3K36me2 modification at the promoter region of MNAT1 component of CDK activating kinase (MNAT1), to promote its transcription. MNAT1 was correlated with an unfavorable clinical outcome of PAAD patients. Alteration of MNAT1 alone also affected the malignant behavior of PAAD cells. Moreover, MNAT1 overexpression in cells rescued the malignant phenotype of cells suppressed by SMYD2 silencing. MNAT1 activated the phosphatidyl inositol 3-kinase/protein kinase B (PI3K/AKT) signaling. In vivo, SMYD2 silencing decreased the growth rate and weight of xenograft tumors in nude mice. Overall, this paper demonstrates that SMYD2-mediated MNAT1 upregulation is linked to PAAD tumorigenesis via PI3K/AKT pathway activation.

The SMYD3-dependent H3K4me3 status of IGF2 intensifies local Th2 differentiation in CRSwNP via positive feedback

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous and common upper airway disease divided into various inflammatory endotypes. Recent epidemiological findings showed a T helper 2 (Th2)-skewed dominance in CRSwNP patients. Histone modification alterations can regulate transcriptional and translational expression, resulting in abnormal pathogenic changes and the occurrence of diseases. Trimethylation of histone H3 lysine 4 (H3K4me3) is considered an activator of gene expression through modulation of accessibility for transcription, which is closely related to CRSwNP. H3K4me3 levels in the human nasal epithelium may change under Th2-biased inflammatory conditions, resulting in exaggerated local nasal Th2 responses via the regulation of naïve CD4+ T-cell differentiation. Here, we revealed that the level of SET and MYND domain-containing protein 3 (SMYD3)-mediated H3K4me3 was increased in NPs from Th2 CRSwNP patients compared with those from healthy controls. We demonstrated that SMYD3-mediated H3K4me3 is increased in human nasal epithelial cells under Th2-biased inflammatory conditions via S-adenosyl-L-methionine (SAM) production and further found that the H3K4me3high status of insulin-like growth factor 2 (IGF2) produced in primary human nasal epithelial cells could promote naïve CD4+ T-cell differentiation into Th2 cells. Moreover, we found that SAM production was dependent on the c-Myc/methionine adenosyltransferase 2A (MAT2A) axis in the nasal epithelium. Understanding histone modifications in the nasal epithelium has immense potential utility in the development of novel classes of therapeutics targeting Th2 polarization in Th2 CRSwNP.Et9-hJKHbB2Mg3CRtXWvn_Video

SMYD2 regulates vascular smooth muscle cell phenotypic switching and intimal hyperplasia via interaction with myocardin.

The SET and MYND domain-containing protein 2 (SMYD2) is a histone lysine methyltransferase that has been reported to regulate carcinogenesis and inflammation. However, its role in vascular smooth muscle cell (VSMC) homeostasis and vascular diseases has not been determined. Here, we investigated the role of SMYD2 in VSMC phenotypic modulation and vascular intimal hyperplasia and elucidated the underlying mechanism. We observed that SMYD2 expression was downregulated in injured carotid arteries in mice and phenotypically modulated VSMCs in vitro. Using an SMC-specific SMYD2 knockout mouse model, we found that SMYD2 ablation in VSMCs exacerbated neointima formation after vascular injury in vivo. Conversely, SMYD2 overexpression inhibited VSMC proliferation and migration in vitro and attenuated arterial narrowing in injured vessels in mice. SMYD2 downregulation promoted VSMC phenotypic switching accompanied with enhanced proliferation and migration. Mechanistically, genome-wide transcriptome analysis and loss/gain-of-function studies revealed that SMYD2 up-regulated VSMC contractile gene expression and suppressed VSMC proliferation and migration, in part, by promoting expression and transactivation of the master transcription cofactor myocardin. In addition, myocardin directly interacted with SMYD2, thereby facilitating SMYD2 recruitment to the CArG regions of SMC contractile gene promoters and leading to an open chromatin status around SMC contractile gene promoters via SMYD2-mediated H3K4 methylation. Hence, we conclude that SMYD2 is a novel regulator of VSMC contractile phenotype and intimal hyperplasia via a myocardin-dependent epigenetic regulatory mechanism.

Histone lysine methyltransferase SMYD3 promotes oral squamous cell carcinoma tumorigenesis via H3K4me3-mediated HMGA2 transcription

BackgroundEpigenetic dysregulation is essential to the tumorigenesis of oral squamous cell carcinoma (OSCC). SET and MYND domain-containing protein 3 (SMYD3), a histone lysine methyltransferase, is implicated in gene transcription regulation and tumor development. However, the roles of SMYD3 in OSCC initiation are not fully understood. The present study investigated the biological functions and mechanisms involved in the SMYD3-mediated tumorigenesis of OSCC utilizing bioinformatic approaches and validation assays with the aim of informing the development of targeted therapies for OSCC.Results429 chromatin regulators were screened by a machine learning approach and aberrant expression of SMYD3 was found to be closely associated with OSCC formation and poor prognosis. Data profiling of single-cell and tissue demonstrated that upregulated SMYD3 significantly correlated with aggressive clinicopathological features of OSCC. Alterations in copy number and DNA methylation patterns may contribute to SMYD3 overexpression. Functional experimental results suggested that SMYD3 enhanced cancer cell stemness and proliferation in vitro and tumor growth in vivo. SMYD3 was observed to bind to the High Mobility Group AT-Hook 2 (HMGA2) promoter and elevated tri-methylation of histone H3 lysine 4 at the corresponding site was responsible for transactivating HMGA2. SMYD3 also was positively linked to HMGA2 expression in OSCC samples. Furthermore, treatment with the SMYD3 chemical inhibitor BCI-121 exerted anti-tumor effects.ConclusionsHistone methyltransferase activity and transcription-potentiating function of SMYD3 were found to be essential for tumorigenesis and the SMYD3–HMGA2 is a potential therapeutic target in OSCC.

Discovery of Novel Lysine Methyltransferase (SMYD3) Inhibitors by Utilizing 3D-QSAR, Molecular Docking and Molecular Dynamics Simulation

Aim: To investigate novel isoxazole amide SMYD3 inhibitors as adjuvant anticancer agents for multiple cancers. Background: SET and MYND Domain-Containing Protein 3 is a hopeful therapeutic target for breast, liver, colon, and prostate cancer. Objective: Novel SMYD3 inhibitors were predicted by the 3D-QSAR models. Method: In this present work, 3D-QSAR, molecular docking and molecular dynamics (MD) simulations were performed on a series of isoxazole amides-based SMYD3 inhibitors. Result: Molecular docking revealed residues important to protein-compound interactions, indicating that SMYD3 inhibitors have a strong affinity with and bind to key protein residues such as TYR239, MET190, LYS297 and VAL368. The molecular docking results were further validated by molecular dynamics simulations. Conclusion: The above information provided significant guidance for the design of novel SMYD3 inhibitors.

Histone methyltransferase Smyd2 drives vascular aging by its enhancer-dependent activity

Vascular aging is one of the important factors contributing to the pathogenesis of cardiovascular diseases. However, the systematic epigenetic regulatory mechanisms during vascular aging are still unclear. Histone methyltransferase SET and MYND domain-containing protein 2 (Smyd2) is associated with multiple diseases including cancer and inflammatory diseases, but whether it is involved in endothelial cell senescence and aging-related cardiovascular diseases has not been directly proved. Thus, we aim to address the effects of Smyd2 on regulating angiotensin II (Ang II)-induced vascular endothelial cells (VECs) senescence and its epigenetic mechanism. The regulatory role of Smyd2 in Ang II-induced VECs senescence was confirmed by performing loss and gain function assays. Chromatin immunoprecipitation-sequencing (ChIP-seq) analysis was used to systematically screen the potential enhancer during VECs senescence. Here, we found that Smyd2 was significantly upregulated in Ang II-triggered VECs, and deficiency of Smyd2 attenuated senescence-associated phenotypes both in vitro and in vivo. Mechanically, Ang II-induced upregulation of Smyd2 could increase the mono-methylation level of histone 3 lysine 4 (H3K4me1), resulting in a hyper-methylated chromatin state, then further activating enhancers adjacent to key aging-related genes, such as Cdkn1a and Cdkn2a, finally driving the development of vascular aging. Collectively, our study uncovered that Smyd2 drives a hyper-methylated chromatin state via H3K4me1 and actives the enhancer elements adjacent to key senescence genes such as Cdkn1a and Cdkn2a, and further induces the senescence-related phenotypes. Targeting Smyd2 possibly unveiled a novel therapeutic candidate for vascular aging-related diseases.

SMYD2 Promotes Hepatocellular Carcinoma Progression by Reprogramming Glutamine Metabolism via c-Myc/GLS1 Axis

Metabolic reprogramming, such as alterations in glutamine metabolism or glycolysis, is the hallmark of hepatocellular carcinoma (HCC). However, the underlying mechanisms are still incompletely elucidated. Previous studies have identified that methyltransferase SET and MYND domain-containing protein 2(SMYD2) is responsible for the pathogenesis of numerous types of cancer. Here, we innovatively uncover how SMYD2 regulates glutamine metabolism in HCC cells and promotes HCC progression. We identified that SMYD2 expression is upregulated in HCC tissues, which correlates with unfavorable clinical outcomes. Our in vitro and in vivo results showed that the depletion of SMYD2 inhibits HCC cell growth. Mechanistically, c-Myc methylation by SMYD2 increases its protein stability through the ubiquitin-proteasome system. We showed SMYD2 depletion destabilized c-Myc protein by increasing the conjugated K48-linked polyubiquitin chain. SMYD2 increased c-Myc expression and further upregulated glutaminase1 (GLS1), a crucial enzyme that catalyzes the conversion of glutamine to glutamic acid, in HCC cells. GLS1 plays an important role in SMYD2-mediated HCC progression and glutamine metabolism regulation. The knockdown of SMYD2 inhibited glutamine metabolism in HCC cells and overcame their chemoresistance to sorafenib. Collectively, our findings demonstrated a novel mechanism of how SMYD2 promotes HCC progression by regulating glutamine metabolism through the c-Myc/GLS1signaling, implicating the therapeutic potential of targeting SMYD2 in HCC patients.

Effect of miRNA-200b on the proliferation of liver cancer cells via targeting SMYD2/p53 signaling pathway.

Our previous study has verified that high level of SET and MYND domain-containing protein 2 (SMYD2) plays an important role in acquiring aggressive ability for liver cancer cells in hepatocellular carcinoma. MiR-200b as a tumor suppressor gene involves in a variety of cancers. This study aims to investigate the correlation between miR-200b and SMYD2 in hepatocellular carcinoma and the underlying mechanism. Firstly, the levels of SMYD2 and miR-200b in hepatocellular carcinoma tissues and matched adjacent non-tumor liver tissues were tested with real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. Secondly, we evaluated the interaction between miR-200b and SMYD2 using dual-luciferase reporter assay. Thirdly, we elucidated the effect of miR-200b on SMYD2 and its downstream targets p53/CyclinE1. Finally, we silenced SMYD2 in hepatocellular carcinoma cell lines to investigate its effect on tumor proliferation and cell cycle progression, and further confirmed the correlation among SMYD2 and p53/CyclinE1. Compared with the matched adjacent non-tumor liver tissues, miR-200b was obviously decreased, and SMYD2 was significantly increased in hepatocellular carcinoma (both P<0.05). Spearman's rank correlation revealed that miR-200b expression was negatively correlated with SMYD2 (P<0.01). Computer algorithm and dual-luciferase reporter assay revealed that miR-200b directly targeted and suppressed SMYD2 in HEK 293T cells. The down-regulated miR-200b expression promoted hepatoma cell proliferation (P<0.05) and increased SMYD2 expression(P<0.01), while the up-regulated expression of miR-200b had an opposite effect. The knockdown of SMYD2 suppressed the proliferation of MHCC-97L cells (P<0.01), down-regulated CyclinE1, and up-regulated p53 expression (both P<0.05). MiR-200b is involved in hepatocellular carcinoma progression via targeting SMYD2 and regulating SMYD2/p53/CyclinE1 signaling pathway and may be used as a potential target for hepatocellular carcinoma treatment.

Histone methyltransferase Smyd2 drives adipogenesis via regulating STAT3 phosphorylation

Adipogenesis is a complex cascade involved with the preadipocytes differentiation towards mature adipocytes, accelerating the onset of obesity. Histone methyltransferase SET and MYND domain-containing protein 2 (Smyd2), is involved in a variety of cellular biological functions but the epigenetic regulation of Smyd2 in adipogenesis and adipocyte differentiation remains unclear. Both Smyd2 siRNA and LLY-507, an inhibitor of Smyd2, were used to examine the effect of Smyd2 on adipogenesis and adipocyte differentiation in vitro. Smyd2 heterozygous knockout (Smyd2+/−) mice were also constructed to validate the relationship between Smyd2 and adipogenesis in vivo. We found that Smyd2 is abundant in white adipose tissue and closely correlated with adipocyte differentiation. Knockdown or inhibition of Smyd2 restrained adipocyte differentiation in vitro, which requires the phosphorylation of STAT3. In vivo functional validation, Smyd2+/− mice exert significant fat loss but not susceptible to HFD-induced obesity. Taken together, our findings revealed that Smyd2 is a novel regulator of adipocyte differentiation by regulating the phosphorylation of STAT3, which provides insights into the effects of epigenetic regulation in adipogenesis. Inhibition of Smyd2 might represent a viable strategy for anti-adipogenesis and maybe further alleviate obesity-related diseases in humans.

The lysine methyltransferases SET and MYND domain containing 2 (Smyd2) and Enhancer of Zeste 2 (Ezh2) co-regulate osteoblast proliferation and mineralization

Bone formation is controlled by histone modifying enzymes that regulate post-translational modifications on nucleosomal histone proteins and control accessibility of transcription factors to gene promoters required for osteogenesis. Enhancer of Zeste homolog 2 (EZH2/Ezh2), a histone H3 lysine 27 (H3K27) methyl transferase, is a suppressor of osteoblast differentiation. Ezh2 is regulated by SET and MYND domain-containing protein 2 (SMYD2/Smyd2), a lysine methyltransferase that modifies both histone and non-histone proteins. Here, we examined whether Smyd2 modulates Ezh2 suppression of osteoblast differentiation. Musculoskeletal RNA-seq data show that SMYD2/Smyd2 is the most highly expressed SMYD/Smyd member in human bone tissues and mouse osteoblasts. Smyd2 loss of function analysis in mouse MC3T3 osteoblasts using siRNA depletion enhances proliferation and calcium deposition. Loss of Smyd2 protein does not affect alkaline phosphatase activity nor does it result in a unified expression response for standard osteoblast-related mRNA markers (e.g., Bglap, Ibsp, Spp1, Sp7), indicating that Smyd2 does not directly control osteoblast differentiation. Smyd2 protein depletion enhances levels of the osteo-suppressive Ezh2 protein and H3K27 trimethylation (H3K27me3), as expected from increased cell proliferation, while elevating the osteo-inductive Runx2 protein. Combined siRNA depletion of both Smyd2 and Ezh2 protein is more effective in promoting calcium deposition when compared to loss of either protein. Collectively, our results indicate that Smyd2 inhibits proliferation and indirectly the subsequent mineral deposition by osteoblasts. Mechanistically, Smyd2 represents a functional epigenetic regulator that operates in parallel to the suppressive effects of Ezh2 and H3K27 trimethylation on osteoblast differentiation.

SMYD3 regulates gastric cancer progression and macrophage polarization through EZH2 methylation.

SET and MYND domain-containing protein 3 (SMYD3), a known histone methyltransferase, was reported to regulate cancer pathogenesis. However, its role in gastric development and progression remains unclear. EZH2 methylation had been associated with cancer metastasis, but the EZH2 methylation status in gastric cancer (GC) is unknown. Here, we report that EZH2 K421 methylation was responsible for gastric cancer cell soft agar colony formation, in vivo metastasis, and macrophage polarization. Mechanically, we identified SMYD3 as the methyltransferase of EZH2 at K421 residue which accelerates EZH2 Ubiquitin proteasome degradation. Cell harboring non-methylated EZH2 mutants promotes gastric cancer cell metastasis. Taken together, our results showed that SMYD3-EZH2 axis restricts gastric cancer metastasis via integrating epigenetic signaling.

STUB1-SMYD2 Axis Regulates Drug Resistance in Glioma cells.

SET and MYND domain-containing protein 2 (SMYD2) is an important epigenetic regulator that methylates histone and non-histone proteins. The study aimed to investigate the oncogenic role of SMYD2 in gliomas and explore its degradation mechanism induced by cisplatin. Tumor tissue microarray of 441 patients with glioma was collected for SMYD2 immunohistochemical staining. Kaplan-Meier survival curves were constructed using the overall survival values. mRNA-sequencing analysis was performed for understanding the downstream mechanisms mediated by SMYD2. The half-inhibitory concentrations (IC50) of temozolomide and cisplatin in AZ505-treated and control cells were calculated. The potential E3 ubiquitin ligase of SMYD2 was predicted in UbiBrowser and confirmed by a knockdown test. The effect of SMYD2 and its E3 ligase on apoptosis and migration of glioma cells was determined via cell-function assays. High SMYD2 expression correlated with a high WHO stage (P = 0.004) and a low survival probability (P = 0.012). The inhibition of SMYD2 suppressed the process of epithelial to mesenchymal transition (EMT) by downregulating the expression of Collagen 1A1 (COL1A1). AZ505 treatment significantly increased the drug sensitivity of glioma cells. SMYD2 expression was markedly reduced by cisplatin treatment via STIP1 Homology And U-Box Containing Protein 1 (STUB1)-mediated degradation. The knockdown of STUB1 could partly reverse the cell function impairment induced by cisplatin. Our findings suggested that SMYD2 could be a potential drug target for the treatment of gliomas, and STUB1-mediated degradation of SMYD2 plays an important role in reversing chemotherapy resistance in patients with gliomas.

Mechanistic and functional extrapolation of SET and MYND domain-containing protein 2 to pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal neoplasms worldwide and represents the vast majority of pancreatic cancer cases. Understanding the molecular pathogenesis and the underlying mechanisms involved in the initiation, maintenance, and progression of PDAC is an urgent need, which may lead to the development of novel therapeutic strategies against this deadly cancer. Here, we review the role of SET and MYND domain-containing protein 2 (SMYD2) in initiating and maintaining PDAC development through methylating multiple tumor suppressors and oncogenic proteins. Given the broad substrate specificity of SMYD2 and its involvement in diverse oncogenic signaling pathways in many other cancers, the mechanistic extrapolation of SMYD2 from these cancers to PDAC may allow for developing new hypotheses about the mechanisms driving PDAC tumor growth and metastasis, supporting a proposition that targeting SMYD2 could be a powerful strategy for the prevention and treatment of PDAC.

SMYD2 epigenetically activates MEX3A and suppresses CDX2 in colorectal cancer cells to augment cancer growth.

Dysfunction of the protein methyltransferase SET and MYND domain-containing protein 2 (SMYD2) is frequently linked to multiple diseases including cancer. The study focused on the role of SMYD2 in colorectal cancer (CRC) development. SMYD2 was expressed at high levels in CRC tissues and cells. Knockdown of SMYD2 in LOVO cells reduced cell proliferation, migration and invasiveness in vitro and it suppressed xenograft tumorigenesis in vivo. Overexpression of SMYD2 in HCT116 cells led to inverse trends. Mex-3 RNA binding family member A (MEX3A) was predicted as a target of SMYD2. Chromatin immunoprecipitation (ChIP)-reverse transcription quantitative polymerase chain reaction (qPCR) and cellular assays were performed and validated that SMYD2 activated MEX3A expression by promoting H3K36me2 modification on its promoter. Data in the STRING bioinformatics system indicated caudal type homeobox 2 (CDX2) as an important MEX3A-related gene. Silencing of MEX3A alone blocked proliferation and growth of CRC cells in vitro and in vivo, whereas MEX3A overexpression promoted cell growth by suppressing CDX2. In rescue experiments, MEX3A silencing suppressed the cell growth augmented by SMYD2, and CDX2 downregulation restored the malignance of cancer cells inhibited by MEX3A silencing. Taken together, this study reports that SMYD2-mediated activation of MEX3A augments progression of CRC by suppressing CDX2.

Clinicopathological and Prognostic Significance of SMYD3 in Human Cancers: A Systematic Review and Meta-analysis.

Background: Dysregulation of the SET and MYND domain-containing protein 3 (SMYD3) has been found in multiple cancers. This meta-analysis aimed to elucidate the association between SMYD3 expression and clinical outcomes in cancer. Methods: A systematic search of Web of Science, Embase, PubMed, Cochrane Library, and CNKI was conducted. The relationship between SMYD3 expression and cancer patients' overall survival (OS) was evaluated using pooled hazard ratios (HRs) and their corresponding confidence intervals (95% CIs). The association between SMYD3 expression and clinicopathological features was assessed using odds ratios (ORs) with 95% CIs, including tumor size, lymph node metastasis (LNM), distance metastasis, and TNM stage. Results: In total, 715 cancer patients with hepatocellular carcinoma, nonsmall cell lung carcinoma, esophageal squamous cell carcinoma, glioma, colorectal cancer, and/or bladder cancer from seven studies were included in our meta-analysis. SMYD3 overexpression was significantly associated with poor OS (HR = 1.81, 95% CI: 1.38-2.37, p < 0.01) with no heterogeneity (I2 = 0.0%, p = 0.929) in various cancers. Subgroup analysis showed that the prognostic value of SMYD3 across multiple tumors was constant as the tumor type, sample size, and methods of data extraction changed. Increased SMYD3 expression was positively associated with LNM (OR = 1.88, 95% CI = 1.33-2.66, p < 0.001), tumor size (OR = 1.68, 95% CI: 1.09-2.60, p = 0.019), and advanced TNM stage (OR = 1.84, 95% CI: 1.25-2.69, p = 0.002). Conclusions: Upregulation of SMYD3 was significantly associated with poor prognosis in various cancers, suggesting that SMYD3 may be a useful prognostic biomarker.

Ensemble Simulations and Experimental Free Energy Distributions: Evaluation and Characterization of Isoxazole Amides as SMYD3 Inhibitors.

Optimization of binding affinities for ligands to their target protein is a primary objective in rational drug discovery. Herein, we report on a collaborative study that evaluates various compounds designed to bind to the SET and MYND domain-containing protein 3 (SMYD3). SMYD3 is a histone methyltransferase and plays an important role in transcriptional regulation in cell proliferation, cell cycle, and human carcinogenesis. Experimental measurements using the scintillation proximity assay show that the distributions of binding free energies from a large number of independent measurements exhibit non-normal properties. We use ESMACS (enhanced sampling of molecular dynamics with approximation of continuum solvent) and TIES (thermodynamic integration with enhanced sampling) protocols to predict the binding free energies and to provide a detailed chemical insight into the nature of ligand–protein binding. Our results show that the 1-trajectory ESMACS protocol works well for the set of ligands studied here. Although one unexplained outlier exists, we obtain excellent statistical ranking across the set of compounds from the ESMACS protocol and good agreement between calculations and experiments for the relative binding free energies from the TIES protocol. ESMACS and TIES are again found to be powerful protocols for the accurate comparison of the binding free energies.

METHYLTRANSFERASE SMYD2 MODULATES THERAPEUTIC EFFECTS OF EPIDERMAL GROWTH FACTOR IN INFLAMMATORY BOWEL DISEASE

Abstract BACKGROUND Inflammatory bowel disease (IBD) is a chronic and remitting inflammatory disorder of the gastrointestinal tract. A prior clinical trial demonstrated the ability of epidermal growth factor receptor (EGFR) ligand EGF to induce and maintain remission in ulcerative colitis. As a protein lysine methyltransferase, SET and MYND domain-containing protein 2 (SMYD2) regulates various cellular functions, including chromatin remodeling and tumorigenesis. A bioinformatic study has shown that EGFR might be a candidate for SMYD2-mediated methylation. In this research, we aimed to investigate whether SMYD2 depletion could synergize with EGFR-activating treatment to promote intestinal goblet cell regeneration in IBD. METHODS SMYD2 flox C57BL/6 (SMYD2fl/fl) and intestine epithelial cell-specific conditional knockout of SMYD2 (SMYD2ΔIEC) male mice (8 to10-week old) were given 3 cycles of DSS treatment, each cycle including 5 days of 2% DSS in drinking water followed by 16 days of normal drinking water. EGF (50 μg/kg/day) was administered via intraperitoneal injection once per day for 6 days during the third cycle of DSS treatment (from day 42 to 47 along with DSS administration). The disease activity index (DAI), including body weight loss, stool consistency and colorectal bleeding, was monitored and calculated daily. Histologic scoring was used to evaluate the extent of histopathologic change in middle colon tissue. Goblet cell differentiation and maturation was analyzed via Alcian Blue/periodic acid-Schiff (AB/PAS) staining and immunostaining. RESULTS EGF treatment significantly increased the number of goblet cells (AB/PAS staining positive cells) in both SMYD2fl/fl and SMYD2ΔIEC mice. However, in SMYD2ΔIEC mice, more mature goblet cells were observed. In contrast, in SMYD2fl/fl mice, most goblet cells were accumulated at the lower half of colon crypts with small mucin particles. As compared with SMYD2fl/fl mice receiving EGF treatment, SMYD2 depletion combined with EGF injection (6 days) failed to significantly improve body weight loss and DAI scoring during DSS treatment, as well as histologic scoring (including inflammatory cell infiltration and epithelial tissue damage). Immunostaining of goblet cell differentiation markers (including ATOH1, SPDEF and KLF4) revealed no significant difference between SMYD2fl/fl and SMYD2ΔIEC mice. CONCLUSION SMYD2 depletion combined with EGF treatment could promote goblet cell expansion and maturation in mouse DSS-induced chronic colitis. However, the mechanism by which SMYD2 depletion facilitates goblet cell maturation needs further investigation.

NOVEL FUNCTION OF MYELOID METHYLTRANSFERASE SMYD5 IN INFLAMMATORY BOWEL DISEASE PROGRESSION

Abstract Background and Aims SET and MYND domain-containing protein 5 (SMYD5) is a lysine methyltransferase and broadly expressed across various tissues, including immune cells. However, the myeloid SMYD5 in inflammatory bowel disease is entirely unknown. Here, we interrogated the role of SMYD5 in IBD pathogenesis and progression. METHODS Colitis was induced in myeloid-specific Smyd5 knockout (Smyd5fl/flLyz2+/-) and floxed control (Smyd5fl/fl) mice through DSS administration in drinking water for 7 days followed by regulator drinking water for 1 day. The induction of colitis was evaluated by measuring relative body weight loss, disease activity index, and histological as well as morphological changes in the colon. The infiltration of macrophages and neutrophils was examined by immunohistochemical staining. Smyd5 depletion in the myeloid cells in Smyd5fl/flLyz2+/- mice was confirmed by quantitative real-time PCR (RT-PCR). The formation of neutrophil extracellular traps (NET) was observed by immunofluorescence microscopy in vitro and in vivo. RESULTS Smyd5fl/flLyz2+/- mice administered with DSS displayed a significantly worsened colitis reflected by profound body weight loss and an exaggerated disease activity compared to Smyd5fl/fl mice that received DSS. Meanwhile, Smyd5fl/flLyz2+/- mice receiving DSS exhibited severer tissue damages and immune cell infiltration compared to Smyd5fl/fl mice. In addition, more infiltrated neutrophils were observed in the colon tissues of Smyd5fl/flLyz2+/- mice than in Smyd5fl/fl mice that received DSS. However, the infiltration of macrophages was comparable between these two groups. Moreover, we also observed exaggerated NET formation when Smyd5 was silenced both in vitro and in vivo. CONCLUSION Our findings suggest that SMYD5 depletion in myeloid cells leads to exaggerated disease in acute experimental colitis. Furthermore, these data revealed that SMYD5 might play a critical role in suppressing inflammatory response and could serve as a potential therapeutic target in IBD.

NOVEL FUNCTION OF MYELOID METHYLTRANSFERASE SMYD5 IN INFLAMMATORY BOWEL DISEASE PROGRESSION

SET and MYND domain-containing protein 5 (SMYD5) is a lysine methyltransferase and broadly expressed across various tissues, including immune cells. However, the myeloid SMYD5 in inflammatory bowel disease is entirely unknown. Here, we interrogated the role of SMYD5 in IBD pathogenesis and progression.