The mechanism and potential targets of class II HDACs in angiogenesis

Molecular mechanism of VE-cadherin in regulating endothelial cell behaviour during angiogenesis

Vascular endothelial (VE)-cadherin, an endothelium-specific adhesion protein, is found in the junctions between endothelial cells (ECs). It's crucial to maintain the homogeneity of ECs. Keeping and controlling the contact between ECs is essential. In addition to its adhesive function, VE-cadherin plays important roles in vascular development, permeability, and tumour angiogenesis. Signal transfer, cytoskeletal reconstruction, and contractile integrating, which are crucial for constructing and maintaining monolayer integrity as well as for repair and regeneration, are the foundation of endothelial cell (EC) junctional dynamics. The molecular basis of adhesion junctions (AJs), which are closely related and work with actin filaments, is provided by the VE-cadherin-catenin complex. They can activate intracellular signals that drive ECs to react or communicate structural changes to junctions. An increasing number of molecules, including the vascular endothelial growth factor receptor 2 (VEGFR2) and vascular endothelial protein tyrosine phosphatase (VE-PTP), have been connected to VE-cadherin in addition to the conventional VE-cadherin-catenin complex. This review demonstrates significant progress in our understanding of the molecular mechanisms that affect VE-cadherin's function in the regulation of EC behaviour during angiogenesis. The knowledge of the molecular processes that control VE-cadherin's role in the regulation of EC behaviour during angiogenesis has recently advanced, as shown in this review.

miR-101-3p improves neuronal morphology and attenuates neuronal apoptosis in ischemic stroke in young mice by downregulating HDAC9

Objective

MiRNAs play a key role in ischemic stroke (IS). Although miR-101-3p can participate in multiple disease processes, its role and mechanism in IS are not clear. The aim of the present study was to observe the effect of miR-101-3p activation on IS in young mice and the role of HDAC9 in this effect.

Methods

The young mice were first subjected to transient middle cerebral artery occlusion (tMCAO) or sham surgery, and the cerebral infarct area was assessed with 2,3,5-triphenyltetrazolium chloride staining. Meanwhile, the expressions of miR-101-3p and HDAC9 were tested using RT-qPCR or western blot. Besides, neuron morphology and apoptosis were confirmed using Nissl staining and TUNEL staining.

Results

We first verified that miR-101-3p was downregulated and HDAC9 was upregulated in the brain tissue of tMCAO young mice. Moreover, we proved that overexpression of miR-101-3p could improve cerebral infarction, neuronal morphology, and neuronal apoptosis in tMCAO young mice by lowering the expression of HDAC9.

Conclusions

Activation of miR-101-3p can protect against IS in young mice, and its mechanism is relevant to the inhibition of HDAC9. Therefore, miR-101-3p and HDAC9 might be the latent targets for IS therapy.

Yeast beta-glucan mediates histone deacetylase 5-induced angiogenesis in vascular endothelial cells

The role of yeast-derived β-glucan in angiogenesis has not been elucidated because there have been few specific studies on its clinical and physiological significance. Therefore, this study investigated the correlation between β-glucan and histone deacetylase 5 (HDAC5) in human umbilical vein endothelial cells (HUVECs), revealing the role of β-glucan in angiogenesis. We confirmed that HDAC5 was phosphorylated by β-glucan stimulation and released from the nucleus to the cytoplasm. Furthermore, we found that β-glucan-stimulated HDAC5 translocation mediates the transcriptional activation of MEF2. As a result, the expression of KLF2, EGR2, and NR4A2, whose expression is MEF2-dependent and involved in angiogenesis, increased. Thus, we showed the activity of β-glucan in angiogenesis through in vitro and ex vivo assays including cell migration, tube formation, and aortic ring analyses. Specifically, application of an HDAC5 inhibitor repressed MEF2 transcriptional activation in both in vitro and ex vivo angiogenesis. HDAC5 inhibitor LMK235 inhibited the proangiogenic activity of beta-glucan, suggesting that β-glucan induces angiogenesis through HDAC5. These findings suggest that HDAC5 is essential for angiogenesis, and that β-glucan induces angiogenesis. In conclusion, this study demonstrates that β-glucan induces angiogenesis through HDAC5. It also suggests that β-glucan has potential value as a novel therapeutic agent for modulating angiogenesis.

Comprehensive analysis of histone deacetylases genes in the prognosis and immune infiltration of glioma patients

The occurrence and development of tumors are closely related to histone deacetylases (HDACs). However, their relationship with the overall biology and prognosis of glioma is still unknown. In the present study, we developed and validated a prognostic model for glioma based on HDAC genes. Glioma patients can be divided into two subclasses based on eleven HDAC genes, and patients from the two subclasses had markedly different survival outcomes. Then, using six HDAC genes (HDAC1, HDAC3, HDAC4, HDAC5, HDAC7, and HDAC9), we established a prognostic model for glioma patients, and this prognostic model was validated in an independent cohort. Furthermore, the calculated risk score from six HDACA genes expression was found to be an independent prognostic factor that could predict the five-year overall survival of glioma patients well. High-risk patients have changes in multiple complex functions and molecular signaling pathways, and the gene alterations of high- and low-risk patients were significantly different. We also found that the different survival outcomes of high- and low-risk patients could be related to the differences in immune filtration levels and the tumor microenvironment. Subsequently, we identified several small molecular compounds that could be favorable for glioma patient treatment. Finally, the expression levels of HDAC genes from the prognostic model were validated in glioma and nontumor tissue samples. Our results revealed the clinical utility and potential molecular mechanisms of HDAC genes in glioma. A model based on six HDAC genes can predict the overall survival of glioma patients well, and these genes are potential therapeutic targets.

Combining histone deacetylase inhibitors (HDACis) with other therapies for cancer therapy

Histone deacetylases (HDACs) play an important role in regulating the expression of genes involved in tumorigenesis and tumor maintenance, and hence they have been considered as key targets in cancer therapy. As a novel category of antitumor agents, histone deacetylase inhibitors (HDACis) can induce cell cycle arrest, apoptosis, and differentiation in cancer cells, ultimately combating cancer. Although in the United States, the use of HDACis for the treatment of certain cancers has been approved, the therapeutic efficacy of HDACis as a single therapeutic agent in solid tumorshas been unsatisfactory and drug resistance may yet occur. To enhance therapeutic efficacy and limit drug resistance, numerous combination therapies involving HDACis in synergy with other antitumor therapies have been studied. In this review, we describe the classification of HDACs. Moreover, we summarize the antitumor mechanism of the HDACis for targeting key cellular processes of cancers (cell cycle, apoptosis, angiogenesis, DNA repair, and immune response). In addition, we outline the major developments of other antitumor therapies in combination with HDACis, including chemotherapy, radiotherapy, phototherapy, targeted therapy, and immunotherapy. Finally, we discuss the current state and challenges of HDACis-drugs combinations in future clinical studies, with the aim of optimizing the antitumor effect of such combinations.