TRAP1 drives smooth muscle cell senescence and promotes atherosclerosis via HDAC3-primed histone H4 lysine 12 lactylation.

BACKGROUND AND AIMS: Vascular smooth muscle cell (VSMC) senescence is crucial for the development of atherosclerosis, characterized by metabolic abnormalities. Tumour necrosis factor receptor-associated protein 1 (TRAP1), a metabolic regulator associated with ageing, might be implicated in atherosclerosis. As the role of TRAP1 in atherosclerosis remains elusive, this study aimed to examine the function of TRAP1 in VSMC senescence and atherosclerosis. METHODS: TRAP1 expression was measured in the aortic tissues of patients and mice with atherosclerosis using western blot and RT-qPCR. Senescent VSMC models were established by oncogenic Ras, and cellular senescence was evaluated by measuring senescence-associated ß-galactosidase expression and other senescence markers. Chromatin immunoprecipitation (ChIP) analysis was performed to explore the potential role of TRAP1 in atherosclerosis. RESULTS: VSMC-specific TRAP1 deficiency mitigated VSMC senescence and atherosclerosis via metabolic reprogramming. Mechanistically, TRAP1 significantly increased aerobic glycolysis, leading to elevated lactate production. Accumulated lactate promoted histone H4 lysine 12 lactylation (H4K12la) by down-regulating the unique histone lysine delactylase HDAC3. H4K12la was enriched in the senescence-associated secretory phenotype (SASP) promoter, activating SASP transcription and exacerbating VSMC senescence. In VSMC-specific Trap1 knockout ApoeKO mice (ApoeKOTrap1SMCKO), the plaque area, senescence markers, H4K12la, and SASP were reduced. Additionally, pharmacological inhibition and proteolysis-targeting chimera (PROTAC)-mediated TRAP1 degradation effectively attenuated atherosclerosis in vivo. CONCLUSIONS: This study reveals a novel mechanism by which mitonuclear communication orchestrates gene expression in VSMC senescence and atherosclerosis. TRAP1-mediated metabolic reprogramming increases lactate-dependent H4K12la via HDAC3, promoting SASP expression and offering a new therapeutic direction for VSMC senescence and atherosclerosis.

Anti-tumour activity of Panobinostat in oesophageal adenocarcinoma and squamous cell carcinoma cell lines.

BACKGROUND: Oesophageal cancer remains a challenging disease with high mortality rates and few therapeutic options. In view of these difficulties, epigenetic drugs have emerged as potential alternatives for patient care. The goal of this study was to evaluate the effect and biological consequences of Panobinostat treatment, an HDAC (histone deacetylase) inhibitor already approved for treatment of patients with multiple myeloma, in oesophageal cell lines of normal and malignant origin, with the latter being representative of the two main histological subtypes: adenocarcinoma and squamous cell carcinoma. RESULTS: Panobinostat treatment inhibited growth and hindered proliferation, colony formation and invasion of oesophageal cancer cells. Considering HDAC tissue expression, HDAC1 was significantly upregulated in normal oesophageal epithelium in comparison with tumour tissue, whereas HDAC3 was overexpressed in oesophageal cancer compared to non-malignant mucosa. No differences between normal and tumour tissue were observed for HDAC2 and HDAC8 expression. CONCLUSIONS: Panobinostat exposure effectively impaired malignant features of oesophageal cancer cells. Because HDAC3 was shown to be overexpressed in oesophageal tumour samples, this epigenetic drug may represent an alternative therapeutic option for oesophageal cancer patients.

A novel histone deacetylase inhibitor W2A-16 improves the barrier integrity in brain vascular endothelial cells.

The maturation of brain microvascular endothelial cells leads to the formation of a tightly sealed monolayer, known as the blood-brain barrier (BBB). The BBB damage is associated with the pathogenesis of age-related neurodegenerative diseases including vascular cognitive impairment and Alzheimer's disease. Growing knowledge in the field of epigenetics can enhance the understanding of molecular profile of the BBB and has great potential for the development of novel therapeutic strategies or targets to repair a disrupted BBB. Histone deacetylases (HDACs) inhibitors are epigenetic regulators that can induce acetylation of histones and induce open chromatin conformation, promoting gene expression by enhancing the binding of DNA with transcription factors. We investigated how HDAC inhibition influences the barrier integrity using immortalized human endothelial cells (HCMEC/D3) and the human induced pluripotent stem cell (iPSC)-derived brain vascular endothelial cells. The endothelial cells were treated with or without a novel compound named W2A-16. W2A-16 not only activates Wnt/ß-catenin signaling but also functions as a class I HDAC inhibitor. We demonstrated that the administration with W2A-16 sustained barrier properties of the monolayer of endothelial cells, as evidenced by increased trans-endothelial electrical resistance (TEER). The BBB-related genes and protein expression were also increased compared with non-treated controls. Analysis of transcript profiles through RNA-sequencing in hCMEC/D3 cells indicated that W2A-16 potentially enhances BBB integrity by influencing genes associated with the regulation of the extracellular microenvironment. These findings collectively propose that the HDAC inhibition by W2A-16 plays a facilitating role in the formation of the BBB. Pharmacological approaches to inhibit HDAC may be a potential therapeutic strategy to boost and/or restore BBB integrity.

Dissecting transposable elements and endogenous retroviruses upregulation by HDAC inhibitors in leiomyosarcoma cells: Implications for the interferon response.

Transposable elements (TEs) are of interest as immunomodulators for cancer therapies. TEs can fold into dsRNAs that trigger the interferon response. Here, we investigated the effect of different HDAC inhibitors (HDACIs) on the expression of TEs in leiomyosarcoma cells. Our data show that endogenous retroviruses (ERVs), especially ERV1 elements, are upregulated after treatment with HDAC1/2/3-specific inhibitors. Surprisingly, the interferon response was not activated. We observed an increase in A-to-I editing of upregulated ERV1. This could have an impact on the stability of dsRNAs and the activation of the interferon response. We also found that H3K27ac levels are increased in the LTR12 subfamilies, which could be regulatory elements controlling the expression of proapoptotic genes such as TNFRSF10B. In summary, we provide a detailed characterization of TEs modulation in response to HDACIs and suggest the use of HDACIs in combination with ADAR inhibitors to induce cell death and support immunotherapy in cancer.

DNA mismatch repair defect and intratumor heterogeneous deficiency differently impact immune responses in diffuse large B-cell lymphoma.

Deficient (d) DNA mismatch repair (MMR) is a biomarker predictive of better response to PD-1 blockade immunotherapy in solid tumors. dMMR can be caused by mutations in MMR genes or by protein inactivation, which can be detected by sequencing and immunohistochemistry, respectively. To investigate the role of dMMR in diffuse large B-cell lymphoma (DLBCL), MMR gene mutations and expression of MSH6, MSH2, MLH1, and PMS2 proteins were evaluated by targeted next-generation sequencing and immunohistochemistry in a large cohort of DLBCL patients treated with standard chemoimmunotherapy, and correlated with the tumor immune microenvironment characteristics quantified by fluorescent multiplex immunohistochemistry and gene-expression profiling. The results showed that genetic dMMR was infrequent in DLBCL and was significantly associated with increased cancer gene mutations and favorable immune microenvironment, but not prognostic impact. Phenotypic dMMR was also infrequent, and MMR proteins were commonly expressed in DLBCL. However, intratumor heterogeneity existed, and increased DLBCL cells with phenotypic dMMR correlated with significantly increased T cells and PD-1+ T cells, higher average nearest neighbor distance between T cells and PAX5+ cells, upregulated immune gene signatures, LE4 and LE7 ecotypes and their underlying Ecotyper-defined cell states, suggesting the possibility that increased T cells targeted only tumor cell subsets with dMMR. Only in patients with MYC¯ DLBCL, high MSH6/PMS2 expression showed significant adverse prognostic effects. This study shows the immunologic and prognostic effects of genetic/phenotypic dMMR in DLBCL, and raises a question on whether DLBCL-infiltrating PD-1+ T cells target only tumor subclones, relevant for the efficacy of PD-1 blockade immunotherapy in DLBCL.

N-Myc and STAT Interactor is an Endometriosis Suppressor.

In patients with endometriosis, refluxed endometrial fragments evade host immunosurveillance, developing into endometriotic lesions. However, the mechanisms underlying this evasion have not been fully elucidated. N-Myc and STAT Interactor (NMI) have been identified as key players in host immunosurveillance, including interferon (IFN)-induced cell death signaling pathways. NMI levels are markedly reduced in the stromal cells of human endometriotic lesions due to modulation by the Estrogen Receptor beta/Histone Deacetylase 8 axis. Knocking down NMI in immortalized human endometrial stromal cells (IHESCs) led to elevated RNA levels of genes involved in cell-to-cell adhesion and extracellular matrix signaling following IFNA treatment. Furthermore, NMI knockdown inhibited IFN-regulated canonical signaling pathways, such as apoptosis mediated by Interferon Stimulated Gene Factor 3 and necroptosis upon IFNA treatment. In contrast, NMI knockdown with IFNA treatment activated non-canonical IFN-regulated signaling pathways that promote proliferation, including ß-Catenin and AKT signaling. Moreover, NMI knockdown in IHESCs stimulated ectopic lesions' growth in mouse endometriosis models. Therefore, NMI is a novel endometriosis suppressor, enhancing apoptosis and inhibiting proliferation and cell adhesion of endometrial cells upon IFN exposure.

SARS-CoV-2 nucleocapsid protein promotes self-deacetylation by inducing HDAC6 to facilitate viral replication.

BACKGROUND: The global outbreak of COVID-19 caused by the SARS-CoV-2 has led to millions of deaths. This unanticipated emergency has prompted virologists across the globe to delve deeper into the intricate dynamicity of the host-virus interface with an aim to identify antiviral targets and elucidate host and viral determinants of severe disease. AIM: The present study was undertaken to analyse the role of histone deacetylase 6 (HDAC6) in regulating SARS-CoV-2 infection. RESULTS: Gradual increase in HDAC6 expression was observed in different SARS-CoV-2-permissive cell lines following SARS-CoV-2 infection. The SARS-CoV-2 nucleocapsid protein (N protein) was identified as the primary viral factor responsible for upregulating HDAC6 expression. Downregulation of HDAC6 using shRNA or a specific inhibitor tubacin resulted in reduced viral replication suggesting proviral role of its deacetylase activity. Further investigations uncovered the interaction of HDAC6 with stress granule protein G3BP1 and N protein during infection. HDAC6-mediated deacetylation of SARS-CoV-2 N protein was found to be crucial for its association with G3BP1. CONCLUSION: This study provides valuable insights into the molecular mechanisms underlying the disruption of cytoplasmic stress granules during SARS-CoV-2 infection and highlights the significance of HDAC6 in the process.

Potential role of short-chain fatty acids in the pathogenesis and management of acute lymphocytic leukemia.

Acute lymphocytic leukemia (ALL) is an aggressive hematological malignancy of highly proliferative lymphoblasts. ALL is the most common cancer in children, and is typically treated with combination chemotherapy. The 5-year survival of ALL improved significantly in recent decades with this treatment approach. However, certain age groups (below 2 and over 10 years of age) have much worse prognosis, and over 50% of patients with ALL experience long-term side effects proportional to the dosage of anticancer drugs. Therefore, different treatment strategies are required to improve survival in ALL and to reduce side effects of chemotherapy. Since epigenetic modifications are dominantly reversible, "epidrugs" (drugs targeting epigenetic markers) are considered for feasibility in the treatment of ALL as epigenetic modifications, and acetylation of histones was demonstrated to play a critical role in the pathogenesis of ALL. Histone deacetylases (HDACs) have been shown to be differentially expressed in several hematological malignancies, including ALL. HDAC inhibitors (HDACis) have been shown to express selective toxicity for ALL cells, but they showed limited efficacy and higher than expected toxicity in mouse models or clinical trials in ALL. The aim of this review is to examine the role of the microbiota and microbial metabolites in the mechanisms of HDAC functions, and explore the utilization of the microbiota and microbial metabolites in improving the efficacy of HDACi in ALL. HDAC regulators and natural HDACi are depleted in ALL due to microbiota change leading to a decrease in butyrate and propionate, and HDACi treatment is not effective in ALL due to their short half-life. We propose that HDACi released by the microbiota may be necessary in HDAC regulation and this process is impaired in ALL. Furthermore, the review will also consider the role of restoration of the microbiota or supplementation of natural HDACi in potentially restoring HDAC and HDACi functions.

A patent review of histone deacetylase 8 (HDAC8) inhibitors (2013-present).

INTRODUCTION: The processes and course of several fatal illnesses, such as cancer, inflammatory diseases, and neurological disorders, are closely correlated with HDAC8. Therefore, novel HDAC8 inhibitors represent effective therapeutic possibilities that may help treat these conditions. To yet, there aren't any such particular HDAC8 inhibitors available for sale. This review was conducted to examine recent HDAC8 inhibitors that have been patented over the last ten years. AREAS COVERED: This review focuses on HDAC8 inhibitor-related patents and their therapeutic applications that have been published within the last ten years and are accessible through the Patentscope and Google Patents databases. EXPERT OPINION: A handful of HDAC8 inhibitor-related patents have been submitted over the previous ten years, more selective, and specific HDAC8 inhibitors that are intended to treat a variety of medical diseases. This could lead to the development of novel treatment approaches that target HDAC8. Employing theoretical frameworks and experimental procedures can reveal the creation of new HDAC8 inhibitors with enhanced pharmacokinetic characteristics. A thorough understanding of the role that HDAC8 inhibitors play in cancer including the mechanisms behind HDAC8 in other disorders is necessary.

The effect of intra spinal administration of cerium oxide nanoparticles on central pain mechanism: An experimental study.

This study investigated Cerium oxide nanoparticles (CeONPs) effect on central neuropathic pain (CNP). The compressive method of spinal cord injury (SCI) model was used for pain induction. Three groups were formed by a random allocation of 24 rats. In the treatment group, CeONPs were injected above and below the lesion site immediately after inducing SCI. pain symptoms were evaluated using acetone, Radian Heat, and Von Frey tests weekly for six weeks. Finally, we counted fibroblasts using H&E staining. We evaluated the expression of Cx43, GAD65 and HDAC2 proteins using the western blot method. The analysis of results was done by PRISM software. At the end of the study, we found that CeONPs reduced pain symptoms to levels similar to those observed in normal animals. CeONPs also increased the expression of GAD65 and Cx43 proteins but did not affect HDAC2 inhibition. CeONPs probably have a pain-relieving effect on chronic pain by potentially preserving GAD65 and Cx43 protein expression and hindering fibroblast infiltration.

N-(2-Hydroxyphenyl)-2-Propylpentanamide (HO-AAVPA) Induces Apoptosis and Cell Cycle Arrest in Breast Cancer Cells, Decreasing GPER Expression.

In this work, we performed anti-proliferative assays for the compound N-(2-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA) on breast cancer (BC) cells (MCF-7, SKBR3, and triple-negative BC (TNBC) MDA-MB-231 cells) to explore its pharmacological mechanism regarding the type of cell death associated with G protein-coupled estrogen receptor (GPER) expression. The results show that HO-AAVPA induces cell apoptosis at 5 h or 48 h in either estrogen-dependent (MCF-7) or -independent BC cells (SKBR3 and MDA-MB-231). At 5 h, the apoptosis rate for MCF-7 cells was 68.4% and that for MDA-MB-231 cells was 56.1%; at 48 h, that for SKBR3 was 61.6%, that for MCF-7 cells was 54.9%, and that for MDA-MB-231 (TNBC) was 43.1%. HO-AAVPA increased the S phase in MCF-7 cells and reduced the G2/M phase in MCF-7 and MDA-MB-231 cells. GPER expression decreased more than VPA in the presence of HO-AAVPA. In conclusion, the effects of HO-AAVPA on cell apoptosis could be modulated by epigenetic effects through a decrease in GPER expression.

In vivo vulnerabilities to GPX4 and HDAC inhibitors in drug-persistent versus drug-resistant BRAFV600E lung adenocarcinoma.

The current targeted therapy for BRAFV600E-mutant lung cancer consists of a dual blockade of RAF/MEK kinases often combining dabrafenib/trametinib (D/T). This regimen extends survival when compared to single-agent treatments, but disease progression is unavoidable. By using whole-genome CRISPR screening and RNA sequencing, we characterize the vulnerabilities of both persister and D/T-resistant cellular models. Oxidative stress together with concomitant induction of antioxidant responses is boosted by D/T treatment. However, the nature of the oxidative damage, the choice of redox detoxification systems, and the resulting therapeutic vulnerabilities display stage-specific differences. Persister cells suffer from lipid peroxidation and are sensitive to ferroptosis upon GPX4 inhibition in vivo. Biomarkers of lipid peroxidation are detected in clinical samples following D/T treatment. Acquired alterations leading to mitogen-activated protein kinase (MAPK) reactivation enhance cystine transport to boost GPX4-independent antioxidant responses. Similarly to BRAFV600E-mutant melanoma, histone deacetylase (HDAC) inhibitors decrease D/T-resistant cell viability and extend therapeutic response in vivo.

Acquired Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL) Resistance of Human Colorectal Cancer Cells Is Linked to Histone Acetylation and Is Synergistically Ameliorated by Combination with HDAC Inhibitors.

BACKGROUND: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an attractive target for the treatment of various malignancies; however, its therapeutic potential is limited because of the frequent occurrence of tumor cell resistance. In this study, we determined whether TRAIL resistance acquired by repeated administration could be overcome by HDAC inhibition in human colorectal cancer cells. METHODS: TRAIL-resistant HCT116 human colorectal cancer cells (HCT116-TR) were generated by repeated treatment with 10 and 25 ng/mL TRAIL twice weekly for 28 days. RESULTS: The resulting TRAIL-resistant cells were noncross-resistant to other chemotherapeutic agents. The levels of histone acetylation-related proteins, such as ac-histone H4 and HDAC1, were altered in HCT116-TR cells compared with the parental HCT116 cell line. The combined treatment with TRAIL and HDAC inhibitors significantly increased apoptosis in HCT116-TR cells and indicated a synergistic effect. The mechanism by which HDAC inhibition sensitizes HCT116-TR cells to TRAIL is dependent on the intrinsic pathway. In addition, we found that HDAC inhibition enhanced the sensitivity of cells to TRAIL through mitogen-activated protein kinases/CCAAT/enhancer-binding protein homologs of protein-dependent upregulation of death receptor 5. CONCLUSION: These results suggest that histone acetylation is responsible for acquired TRAIL resistance after repeated exposure and acquired resistance to TRAIL may be overcome by combination therapies with HDAC inhibitors.

A novel selenium analog of HDACi-based twin drug induces apoptosis and cell cycle arrest via CDC25A to improve prostate cancer therapy.

Cancer therapy has moved from single agents to more mechanism-based targeted approaches. In recent years, the combination of HDAC inhibitors and other anticancer chemicals has produced exciting progress in cancer treatment. Herein, we developed a novel prodrug via the ligation of dichloroacetate to selenium-containing potent HDAC inhibitors. The effect and mechanism of this compound in the treatment of prostate cancer were also studied. Methods: The concerned prodrug SeSA-DCA was designed and synthesized under mild conditions. This compound's preclinical studies, including the pharmacokinetics, cell toxicity, and anti-tumor effect on prostate cancer cell lines, were thoroughly investigated, and its possible synergistic mechanism was also explored and discussed. Results: SeSA-DCA showed good stability in physiological conditions and could be rapidly decomposed into DCA and selenium analog of SAHA (SeSAHA) in the tumor microenvironment. CCK-8 experiments identified that SeSA-DCA could effectively inhibit the proliferation of a variety of tumor cell lines, especially in prostate cancer. In further studies, we found that SeSA-DCA could also inhibit the metastasis of prostate cancer cell lines and promote cell apoptosis. At the animal level, oral administration of SeSA-DCA led to significant tumor regression without obvious toxicity. Moreover, as a bimolecular coupling compound, SeSA-DCA exhibited vastly superior efficacy than the mixture with equimolar SeSAHA and DCA both in vitro and in vivo. Our findings provide an important theoretical basis for clinical prostate cancer treatment. Conclusions: Our in vivo and in vitro results showed that SeSA-DCA is a highly effective anti-tumor compound for PCa. It can effectively induce cell cycle arrest and growth suppression and inhibit the migration and metastasis of PCa cell lines compared with monotherapy. SeSA-DCA's ability to decrease the growth of xenografts is a little better than that of docetaxel without any apparent signs of toxicity. Our findings provide an important theoretical basis for clinical prostate cancer treatment.

Efficacy and Safety of Chidamide in Combination with PD-1 Inhibitor and Radiotherapy for HER2-Negative Advanced Breast Cancer: Study Protocol of a Single Arm Prospective Study.

Purpose: As one of the most important breakthroughs in cancer therapy, immune checkpoint inhibitors have greatly prolonged survival of patients with breast cancer. However, their application and efficacy are limited, especially for advanced HER2-negative breast cancer. It has been reported that epigenetic modulation of the histone deacetylase (HDAC) inhibitor chidamide, as well as immune microenvironment modulation of radiotherapy are potentially synergistic with immunotherapy. Thus, the combination of chidamide, radiotherapy and immunotherapy is expected to improve prognosis of patients with advanced HER2-negative breast cancer. Patients and Methods: This is a single-arm, open, prospective clinical trial investigating the efficacy and safety of the combination of HDAC inhibitor chidamide, anti-PD-1 antibody sintilimab, and the novel immuno-radiotherapy, which aims to enhance efficacy of immunotherapy, in subsequent lines of therapy of HER2-negative breast cancer. Our study will include 35 patients with advanced breast cancer that has failed endocrine therapy and first-line chemotherapy. Participants will receive 30 mg of chidamide twice a week, 200 mg of sintilimab once every 3 weeks, combined with immuno-radiotherapy. Radiotherapy will be centrally 8 Gy for at least one lesion, and at least 1 Gy for the other lesions. We will complete three fractions of radiotherapy in one cycle. The primary endpoint is progression-free survival, and secondary endpoints are objective response rate, disease control rate and safety. Moreover, biomarkers including cytokines and lymphocyte subgroups will be explored. Conclusion: As a single-arm clinical trial, the analysis of the influence of each single treatment is limited. Besides, our study is an open study, which involves neither randomization nor blinding. In spite of the abovementioned limitations, this prospective clinical trial will give an insight into subsequent lines of therapy of HER2-negative advanced breast cancer, prolong the survival or achieve long remission for these participants, and identify potential responders.

Chitosan/PLGA-based tissue engineered nerve grafts with SKP-SC-EVs enhance sciatic nerve regeneration in dogs through miR-30b-5p-mediated regulation of axon growth.

Extracellular vesicles from skin-derived precursor Schwann cells (SKP-SC-EVs) promote neurite outgrowth in culture and enhance peripheral nerve regeneration in rats. This study aimed at expanding the application of SKP-SC-EVs in nerve grafting by creating a chitosan/PLGA-based, SKP-SC-EVs-containing tissue engineered nerve graft (TENG) to bridge a 40-mm long sciatic nerve defect in dogs. SKP-SC-EVs contained in TENGs significantly accelerated the recovery of hind limb motor and electrophysiological functions, supported the outgrowth and myelination of regenerated axons, and alleviated the denervation-induced atrophy of target muscles in dogs. To clarify the underlying molecular mechanism, we observed that SKP-SC-EVs were rich in a variety of miRNAs linked to the axon growth of neurons, and miR-30b-5p was the most important among others. We further noted that miR-30b-5p contained within SKP-SC-EVs exerted nerve regeneration-promoting effects by targeting the Sin3a/HDAC complex and activating the phosphorylation of ERK, STAT3 or CREB. Our findings suggested that SKP-SC-EVs-incorporating TENGs represent a novel type of bioactive material with potential application for peripheral nerve repair in the clinic.

Complete hematologic response in a patient with multiple pretreated angioimmunoblastic T-cell lymphoma after belinostat therapy followed by allogeneic stem cell transplantation: A case report.

Key Clinical Message: Belinostat therapy followed by hematopoietic stem cell transplantation is a promising salvage strategy for heavily pretreated patients with peripheral T-cell lymphoma. Abstract: Effective treatments for peripheral T-cell lymphoma in the relapsed and refractory (r/r) setting are limited. However, with the development and approval of innovative therapies, effective therapeutic options are becoming available for this patient population. This case report describes the treatment course of a patient with multiple r/r nodal follicular T-helper cell lymphoma of angioimmunoblastic type. Treatment with the histone deacetylase inhibitor belinostat as bridging, enabled allogeneic stem cell transplantation and resulted in a durable complete hematologic response for at least 21 months post-transplantation.

LncRNA SNHG12 suppresses adipocyte inflammation and insulin resistance by regulating the HDAC9/Nrf2 axis.

Obesity is often associated with low-grade inflammation. The incidence of obesity has increased annually worldwide, which seriously affects human health. A previous study indicated that long noncoding RNA SNHG12 was downregulated in obesity. Nevertheless, the role of SNHG12 in obesity remains to be elucidated. In this study, qRT-PCR, western blot, and ELISA were utilized to examine the gene and protein expression. Flow cytometry was employed to investigate the M2 macrophage markers. RNA pull-down assay and RIP were utilized to confirm the interactions of SNHG12, hnRNPA1, and HDAC9. Eventually, a high-fat diet-fed mouse model was established for in vivo studies. SNHG12 overexpression suppressed adipocyte inflammation and insulin resistance and promoted M2 polarization of macrophages that was caused by TNF-α treatment. SNHG12 interacted with hnRNPA1 to downregulate HDAC9 expression, which activated the Nrf2 signaling pathway. HDAC9 overexpression reversed the effect of SNHG12 overexpression on inflammatory response, insulin resistance, and M2 phenotype polarization. Overexpression of SNHG12 improved high-fat diet-fed mouse tissue inflammation. This study revealed the protective effect of SNHG12 against adipocyte inflammation and insulin resistance. This result further provides a new therapeutic target for preventing inflammation and insulin resistance in obesity.

Utilization of an optimized AlphaFold protein model for structure-based design of a selective HDAC11 inhibitor with anti-neuroblastoma activity.

AlphaFold is an artificial intelligence approach for predicting the three-dimensional (3D) structures of proteins with atomic accuracy. One challenge that limits the use of AlphaFold models for drug discovery is the correct prediction of folding in the absence of ligands and cofactors, which compromises their direct use. We have previously described the optimization and use of the histone deacetylase 11 (HDAC11) AlphaFold model for the docking of selective inhibitors such as FT895 and SIS17. Based on the predicted binding mode of FT895 in the optimized HDAC11 AlphaFold model, a new scaffold for HDAC11 inhibitors was designed, and the resulting compounds were tested in vitro against various HDAC isoforms. Compound 5a proved to be the most active compound with an IC50 of 365 nM and was able to selectively inhibit HDAC11. Furthermore, docking of 5a showed a binding mode comparable to FT895 but could not adopt any reasonable poses in other HDAC isoforms. We further supported the docking results with molecular dynamics simulations that confirmed the predicted binding mode. 5a also showed promising activity with an EC50 of 3.6 µM on neuroblastoma cells.