Search Results (12)

Background: Triple-negative breast cancer (TNBC) is one of the most aggressive breast cancer subtypes due to its rapid growth, poor prognosis, and low response to chemotherapies owing to a lack of therapeutic targets and drug resistance. Histone deacetylases (HDACs) induce stromal changes that increase extracellular matrix density through the activity of cancer-associated fibroblasts (CAFs). HDACs are overexpressed in TNBC and have been linked to the activation and sustained activity of CAFs. Additionally, HDAC inhibitors decrease the fibroblastic activity. Objectives: We aimed to analyze the antifibrotic effect of the N-(2′-hydroxyphenyl)-2-propylpentanamide (HO-AAVPA), an inhibitor of the HDAC1, 6, and 8 (iHDAC) on TNBC. Methods: The TNBC (4T1) cell line was inoculated under the dorsal skin in mice to develop a TNBC tumor. CAF’s activation was determined by measuring collagen-1 and alpha-smooth muscle actin (α-SMA), as well as their association with the G-protein-coupled estrogenic receptor (GPER1) and HDAC1 expression. Results: Dose of 20 mg/kg of HO-AAVPA decreased tumor fibrosis by inducing decreased collagen-1 and alpha-smooth muscle actin (α-SMA) levels and increased GPER1 expression. Moreover, HO-AAVPA reduced the activation and activity of CAFs. Conclusion: Our results support the notion that HDAC1 inhibition may be a novel approach to sensitizing resistant tumor cells to chemotherapy and radiotherapy by increasing GPER1 expression, and thus the use of antiproliferative GPER1 agonists/antagonists, at least in the early stages, without causing significant changes in liver function or morphological alterations. Full article

Ischemic stroke is a complex, multifactorial disorder with a significant heritable component. Recent developments in genome-wide association studies (GWASs) have identified several common variants associated with clinical outcomes, stroke subtypes, and overall risk. Key loci implicated in biological pathways related to vascular integrity, lipid metabolism, inflammation, and atherogenesis include 9p21 (ANRIL), HDAC9, SORT1, and PITX2. Although polygenic risk scores (PRSs) hold promise for early risk prediction and stratification, their clinical utility remains limited by Eurocentric bias and missing heritability. Integrating multiomics approaches, such as functional genomics, transcriptomics, and epigenomics, enhances our understanding of stroke pathophysiology and paves the way for precision medicine. This review summarizes the current genetic landscape of ischemic stroke, emphasizing how evolving methodologies are shaping its prevention, diagnosis, and treatment. Full article

Cornelia de Lange syndrome (CdLS) is a rare, dominantly inherited multisystem developmental disorder. Pathogenic variants in genes encoding the structural subunits and regulatory proteins of the cohesin complex (NIPBL, SMC1A, SMC3, HDAC8, and RAD21) are the primary contributors to the pathogenesis of CdLS. Pathogenic variations in these genes disrupt normal cohesin function, leading to the syndrome’s diverse and complex clinical presentation. In this study, we discovered that cells harboring variants in the NIPBL, SMC1A and HDAC8 genes exhibit spontaneous genome instability, elevated oxidative stress and premature cellular aging. These findings suggest that cohesin plays a critical role in maintaining proper cellular function and highlight its contribution to the pathophysiology seen in the related diagnoses. Full article

Background: Histone deacetylase 4 (HDAC4) is a member of the class II histone deacetylase family, whose members play a crucial role in various biological processes. An in-depth investigation of the transcriptional characteristics of chicken HDAC4 can provide fundamental insights into its function. Methods: We examined HDAC4 expression in chicken embryonic stem cells (ESC) and spermatogonial stem cells (SSC) and cloned a 444 bp fragment from upstream of the chicken HDAC4 transcription start site. Subsequently, we constructed pEGFP-HDAC4 and a series of 5′-deletion luciferase reporter constructs, which we transfected into DF-1 cells to measure their transcriptional activity. The regulatory mechanisms of chicken HDAC4 expression were investigated by performing trichostatin A (TSA) treatment, deleting putative transcription factor binding sites, and altering transcription factor expression levels. Results: HDAC4 exhibited higher expression in SSC than in ESC. We confirmed that the upstream region from −295 bp to 0 bp is the core transcriptional region of HDAC4. TSA effectively inhibited HDAC4 transcription, and bioinformatics analysis indicated that the chicken core HDAC4 promoter sequence exhibits high homology with those of other avian species. The myelocytomatosis viral oncogene homolog (MYC) and hypoxia-inducible factor 1 α (HIF1A) transcription factors were predicted to bind to this core region. Treatment with TSA for 24 h resulted in the upregulation of MYC and HIF1A, which repressed HDAC4 transcription. Conclusions: Our results provide a basis for subsequent investigations into the regulation of HDAC4 expression and biological function. Full article

A large diversity of epigenetic factors, such as microRNAs and histones modifications, are known to be capable of regulating gene expression without altering DNA sequence itself. In particular, miR-1 is considered the first essential microRNA in cardiac development. In this study, miR-1 potential role in early cardiac chamber differentiation was analyzed through specific signaling pathways. For this, we performed in chick embryos functional experiments by means of miR-1 microinjections into the posterior cardiac precursors—of both primitive endocardial tubes—committed to sinoatrial region fates. Subsequently, embryos were subjected to whole mount in situ hybridization, immunohistochemistry and RT-qPCR analysis. As a relevant novelty, our results revealed that miR-1 increased Amhc1, Tbx5 and Gata4, while this microRNA diminished Mef2c and Cripto expressions during early differentiation of the cardiac sinoatrial region. Furthermore, we observed in this developmental context that miR-1 upregulated CrabpII and Rarß and downregulated CrabpI, which are three crucial factors in the retinoic acid signaling pathway. Interestingly, we also noticed that miR-1 directly interacted with Hdac4 and Calm1/Calmodulin, as well as with Erk2/Mapk1, which are three key factors actively involved in Mef2c regulation. Our study shows, for the first time, a key role of miR-1 as an epigenetic regulator in the early differentiation of the cardiac sinoatrial region through orchestrating opposite actions between retinoic acid and Mef2c, fundamental to properly assign cardiac cells to their respective heart chambers. A better understanding of those molecular mechanisms modulated by miR-1 will definitely help in fields applied to therapy and cardiac regeneration and repair. Full article

Skeletal muscle development remarkably affects meat production and growth rate, regulated by complex regulatory mechanisms in pigs. Specific AT sequence-binding protein 2 (SATB2) is a classic transcription factor and chromatin organizer, which holds a profound effect in the regulation of chromatin remodeling. However, the regulation role of SATB2 concerning skeletal muscle cell fate through chromatin remodeling in pigs remains largely unknown. Here, we observed that SATB2 was expressed higher in the lean-type compared to the obese-type pigs, which also enriched the pathways of skeletal muscle development, chromatin organization, and histone modification. Functionally, knockdown SATB2 led to decreases in the proliferation and migration markers at the mRNA and protein expression levels, respectively, while overexpression SATB2 had the opposite effects. Further, we found histone deacetylase 4 (HDAC4) was a key downstream target gene of SATB2 related to chromatin remodeling. The binding relationship between SATB2 and HDAC4 was confirmed by a dual-luciferase reporter system and ChIP-qPCR analysis. Besides, we revealed that HDAC4 promoted the skeletal muscle cell proliferation and migration at the mRNA and protein expression levels, respectively. In conclusion, our study indicates that transcription factor SATB2 binding to HDAC4 positively contributes to skeletal muscle cell proliferation and migration, which might mediate the chromatin remodeling to influence myogenesis in pigs. This study develops a novel insight into understanding the molecular regulatory mechanism of myogenesis, and provides a promising gene for genetic breeding in pigs. Full article

The objective of this study was to explore the molecular mechanism of male sterility in yak hybrids based on HAT1 and HDAC1. Total RNA was extracted from the testes of adult yaks (n = 11) and sterile cattle-yaks (n = 11) followed by reverse transcription. The coding sequence (CDS) of yak HAT1 and HDAC1 were obtained by conventional polymerase chain reaction (PCR) and gene cloning. The testicular mRNA and protein levels of HAT1 and HDAC1 in yaks and cattle-yaks were detected by quantitative PCR (qPCR) and Western blotting, respectively, and the histone H3 lysine 9 (H3K9) histone acetylation level in the testes of yaks and cattle-yaks was assayed using enzyme linked immunosorbent assay (ELISA). The results showed that the CDS of HAT1 and HDAC1 were 1242 bp and 1449 bp in length, encoding 413 and 482 amino acids, respectively; yaks had a similar mRNA sequence as cattle in both genes. The testicular mRNA and protein levels of HAT1 of cattle-yaks were significantly lower than those of yaks, and the protein level of HDAC1 was significantly higher than that of yaks. ELISA showed that the acetylation level of testicular H3K9 was significantly lower in yak hybrids than that of yaks. The present results suggest that the decreased level of HAT1 and increased level of HDAC1 may result in the decreased H3K9 acetylation in cattle-yaks and might be associated with their sterility. Full article

Cornelia de Lange syndrome (CdLS) is a multisystemic genetic disorder characterized by distinctive facial features, growth retardation, and intellectual disability, as well as various systemic conditions. It is caused by genetic variants in genes related to the cohesin complex. Single-nucleotide variations are the best-known genetic cause of CdLS; however, copy number variants (CNVs) clearly underlie a substantial proportion of cases of the syndrome. The NIPBL gene was thought to be the locus within which clinically relevant CNVs contributed to CdLS. However, in the last few years, pathogenic CNVs have been identified in other genes such as HDAC8, RAD21, and SMC1A. Here, we studied an affected girl presenting with a classic CdLS phenotype heterozygous for a de novo ~32 kbp intragenic duplication affecting exon 10 of HDAC8. Molecular analyses revealed an alteration in the physiological splicing that included a 96 bp insertion between exons 9 and 10 of the main transcript of HDAC8. The aberrant transcript was predicted to generate a truncated protein whose accessibility to the active center was restricted, showing reduced ease of substrate entry into the mutated enzyme. Lastly, we conclude that the duplication is responsible for the patient’s phenotype, highlighting the contribution of CNVs as a molecular cause underlying CdLS. Full article

Germline mutations in predisposition genes account for only 20% of all familial colorectal cancers (CRC) and the remaining genetic burden may be due to rare high- to moderate-penetrance germline variants that are not explored. With the aim of identifying such potential cancer-predisposing variants, we performed whole exome sequencing on three CRC cases and three unaffected members of a Polish family and identified two novel heterozygous variants: a coding variant in APC downregulated 1 gene (APCDD1, p.R299H) and a non-coding variant in the 5′ untranslated region (UTR) of histone deacetylase 5 gene (HDAC5). Sanger sequencing confirmed the variants segregating with the disease and Taqman assays revealed 8 additional APCDD1 variants in a cohort of 1705 familial CRC patients and no further HDAC5 variants. Proliferation assays indicated an insignificant proliferative impact for the APCDD1 variant. Luciferase reporter assays using the HDAC5 variant resulted in an enhanced promoter activity. Targeting of transcription factor binding sites of SNAI-2 and TCF4 interrupted by the HDAC5 variant showed a significant impact of TCF4 on promoter activity of mutated HDAC5. Our findings contribute not only to the identification of unrecognized genetic causes of familial CRC but also underline the importance of 5’UTR variants affecting transcriptional regulation and the pathogenesis of complex disorders. Full article

In this study we surveyed a rat skeletal muscle RNA-Seq for genes that are induced by hindlimb immobilization and, in turn, become attenuated by leucine supplementation. This approach, in search of leucine-atrophy protection mediating genes, identified histone deacetylase 4 (HDAC4) as highly responsive to both hindlimb immobilization and leucine supplementation. We then examined the impact of leucine on HDAC4 expression, tissue localization, and target genes. A total of 76 male Wistar rats (~280 g) were submitted to hindlimb immobilization and/or leucine supplementation for 3, 7 and 12 days. These animals were euthanized, and soleus muscle was removed for further analysis. RNA-Seq analysis of hindlimb immobilized rats indicated a sharp induction (log2 = 3.4) of HDAC4 expression which was attenuated by leucine supplementation (~50%). Real-time PCR and protein expression analysis by Western blot confirmed increased HDAC4 mRNA after 7 days of hindlimb immobilization and mitigation of induction by leucine supplementation. Regarding the HDAC4 localization, the proportion of positive nuclei was higher in the immobilized group and decreased after leucine supplementation. Also, we found a marked decrease of myogenin and MAFbx-atrogin-1 mRNA levels upon leucine supplementation, while CAMKII and DACH2 mRNA levels were increased by leucine supplementation. Our data suggest that HDAC4 inhibition might be involved in the anti-atrophic effects of leucine. Full article

Nrf2 is a transcription factor that regulates cellular redox balance and the expression of a wide array of genes involved in immunity and inflammation, including antiviral actions. Nrf2 activity declines with age, making the elderly more susceptible to oxidative stress-mediated diseases, which include type 2 diabetes, chronic inflammation, and viral infections. Published evidence suggests that Nrf2 activity may regulate important mechanisms affecting viral susceptibility and replication. We examined gene expression levels by GeneChip microarray and by RNA-seq assays. We found that the potent Nrf2-activating composition PB125^® downregulates ACE2 and TMPRSS2 mRNA expression in human liver-derived HepG2 cells. ACE2 is a surface receptor and TMPRSS2 activates the spike protein for SARS-CoV-2 entry into host cells. Furthermore, in endotoxin-stimulated primary human pulmonary artery endothelial cells, we report the marked downregulation by PB125 of 36 genes encoding cytokines. These include IL-1-beta, IL-6, TNF-α, the cell adhesion molecules ICAM-1, VCAM-1, and E-selectin, and a group of IFN-γ-induced genes. Many of these cytokines have been specifically identified in the “cytokine storm” observed in fatal cases of COVID-19, suggesting that Nrf2 activation may significantly decrease the intensity of the storm. Full article

Cancer complexity relies on the intracellular pleiotropy of oncogenes/tumor suppressors and in the strong interplay between tumors and micro- and macro-environments. Here we followed a reductionist approach, by analyzing the transcriptional adaptations induced by three oncogenes (RAS, MYC, and HDAC4) in an isogenic transformation process. Common pathways, in place of common genes became dysregulated. From our analysis it emerges that, during the process of transformation, tumor cells cultured in vitro prime some signaling pathways suitable for coping with the blood supply restriction, metabolic adaptations, infiltration of immune cells, and for acquiring the morphological plasticity needed during the metastatic phase. Finally, we identified two signatures of genes commonly regulated by the three oncogenes that successfully predict the outcome of patients affected by different cancer types. These results emphasize that, in spite of the heterogeneous mutational burden among different cancers and even within the same tumor, some common hubs do exist. Their location, at the intersection of the various signaling pathways, makes a therapeutic approach exploitable. Full article