Skin wound healing tends to slow down with aging, which is detrimental to both minor wound recovery in daily life and the recovery after surgery. The aim of current study was to explore the effect of histone deacetylase 6 (HDAC6) on wound healing during aging. Cultured human dermal fibroblasts (HDFs) and mouse full-thickness skin wound model were used to explore the functional changes of replicative senescent dermal fibroblasts and the effect of aging on skin wound healing. Scratch wound healing assay revealed significantly decreased migration speed of senescent HDFs, and BrdU incorporation assay indicated their considerably retardant proliferation. The protein expression levels of collagen and HDAC6 were significantly decreased in both senescent HDFs and skin tissues from aged mice. HDAC6 activity inhibition with highly selective inhibitor tubastatin A (TsA) or HDAC6 knockdown with siRNA decreased the migration speed of HDFs and considerably suppressed fibroblast differentiation induced by transforming growth factor-β1 (TGF-β1), which suggests the involvement of HDAC6 in regulating fundamental physiological activities of dermal fibroblasts. In vivo full-thickness skin wound healing was significantly delayed in young HDAC6 knockout mice when compared with young wild type mice. In addition, the wound healing was significantly slower in aged wild type mice than that in young wild type mice, and became even worse in aged HDAC6 knockout aged mice. Compared to the aged wild type mice, aged HDAC6 knockout mice exhibited delayed angiogenesis, reduced collagen synthesis, and decreased collagen deposition in skin wounds. Together, these results suggest that delayed skin wound healing in aged mice is associated with impaired fibroblast function. Adequate expression and activity of HDAC6 are required for fibroblasts migration and differentiation.
Humans ; Animals ; Mice ; Aged ; Histone Deacetylase 6 ; Skin ; Wound Healing ; Cell Movement ; Collagen/pharmacology* ; Fibroblasts ; Mice, Knockout ; Cells, Cultured

OBJECTIVE: Acute liver failure (ALF) is characterized by severe liver dysfunction, rapid progression and high mortality and is difficult to treat. Studies have found that sulforaphane (SFN), a nuclear factor E2-related factor 2 (NRF2) agonist, has anti-inflammatory, antioxidant and anticancer effects, and has certain protective effects on neurodegenerative diseases, cancer and liver fibrosis. This paper aimed to explore the protective effect of SFN in ALF and it possible mechanisms of action. METHODS: Lipopolysaccharide and D-galactosamine were used to induce liver injury in vitro and in vivo. NRF2 agonist SFN and histone deacetylase 6 (HDAC6) inhibitor ACY1215 were used to observe the protective effect and possible mechanisms of SFN in ALF, respectively. Cell viability, lactate dehydrogenase (LDH), Fe²⁺, glutathione (GSH) and malondialdehyde (MDA) were detected. The expression of HDAC6, NRF2, glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4) and solute carrier family 7 member 11 (SLC7A11) were detected by Western blotting and immunofluorescence. RESULTS: Our results show that NRF2 was activated by SFN. LDH, Fe²⁺, MDA and ACSL4 were downregulated, while GSH, GPX4 and SLC7A11 were upregulated by SFN in vitro and in vivo, indicating the inhibitory effect of SFN on ferroptosis. Additionally, HDAC6 expression was decreased in the SFN group, indicating that SFN could downregulate the expression of HDAC6 in ALF. After using the HDAC6 inhibitor, ACY1215, SFN further reduced HDAC6 expression and inhibited ferroptosis, indicating that SFN may inhibit ferroptosis by regulating HDAC6 activity. CONCLUSION SFN has a protective effect on ALF, and the mechanism may include reduction of ferroptosis through the regulation of HDAC6. Please cite this article as: Zhang YQ, Shi CX, Zhang DM, Zhang LY, Wang LW, Gong ZJ. Sulforaphane, an NRF2 agonist, alleviates ferroptosis in acute liver failure by regulating HDAC6 activity. J Integr Med. 2023; 21(5): 464-473.
Humans ; Ferroptosis ; NF-E2-Related Factor 2/genetics* ; Liver Failure, Acute/drug therapy* ; Isothiocyanates/pharmacology* ; Glutathione ; Histone Deacetylase 6

BACKGROUNDNicotine, a major component of tobacco, is the main cause of smoking addiction. It was found that asthmatic patients who smoke were insensitive to glucocorticoid treatment. In this paper, we investigated whether nicotine could inhibit histone deacetylase 6 activity (HDAC6) and chaperone-dependent activation of the glucocorticoid receptor (GR) in A549 cells. Furthermore, the expression level of heat shock protein 90 (HSP90) was determined.

METHODSQuantitative real-time polymerase chain reaction was used to detect the levels of RNA transcription, and Western blotting was applied to analyze the levels of protein expression of HDAC6, GR, and HSP90 in A549 cells. Moreover, the effects of dexamethasone and trichostatin A were observed in A549 cells.

RESULTSA549 cell proliferation was inhibited in the presence of nicotine, and the level of RNA and protein expression of HDAC6 and GR were down-regulated.

CONCLUSIONSNicotine could inhibit HDAC6 activity and chaperone-dependent activation of GR. This might be the main reason why asthmatic patients who smoke show insensitivity to the glucocorticoid treatment.

Cell Line, Tumor ; Cell Proliferation ; drug effects ; Enzyme Activation ; drug effects ; Histone Deacetylase 6 ; Histone Deacetylases ; genetics ; metabolism ; Humans ; Nicotine ; pharmacology ; Receptors, Glucocorticoid ; genetics ; metabolism

OBJECTIVES: Subarachnoid hemorrhage (SAH) is a serious cerebrovascular disease. Early brain injury (EBI) and cerebral vasospasm are the main reasons for poor prognosis of SAH patients. The specific inhibitor of histone deacetylase 6 (HDAC6), tubastatin A (TubA), has been proved to have a definite neuroprotective effect on a variety of animal models of acute and chronic central nervous system diseases. However, the neuroprotective effect of TubA on SAH remains unclear. This study aims to investigate the expression and localization of HDAC6 in the early stage of SAH, and to evaluate the protective effects of TubA on EBI and cerebral vasospasm after SAH and the underlying mechanisms. METHODS: Adult male SD rats were treated with modified internal carotid artery puncture to establish SAH model. In the first part of the experiment, rats were randomly divided into 6 groups: a sham group, a SAH-3 h group, a SAH-6 h group, a SAH-12 h group, a SAH-24 h group, and a SAH-48 h group. At 3, 6, 12, and 24 h after SAH modeling, the injured cerebral cortex of rats in each group was taken for Western blotting to detect the expression of HDAC6. In addition, the distribution of HDAC6 in the cerebral cortex of the injured side was measured by immunofluorescence double staining in SAH-24 h group rats. In the second part, rats were randomly divided into 4 groups: a sham group, a SAH group, a SAH+TubA_L group (giving 25 mg/kg TubA), and a SAH+TubA_H group (giving 40 mg/kg TubA). At 24 h after modeling, the injured cerebral cortex tissue was taken for Western blotting to detect the expression levels of HDAC6, endothelial nitric oxide synthase (eNOS), and inducible nitric oxide synthase (iNOS), terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) staining to detect apoptosis, and hematoxylin and eosin (HE) staining to detect the diameter of middle cerebral artery. RESULTS: The protein expression of HDAC6 began to increase at 6 h after SAH (P<0.05), peaked at 24 h (P<0.001), and decreased at 48 h, but there was still a difference compared with the sham group (P<0.05). HDAC6 is mainly expressed in the cytoplasm of the neurons. Compared with the sham group, the neurological score was decreased significantly and brain water content was increased significantly in the SAH group (both P<0.01). Compared with the SAH group, the neurological score was increased significantly and brain water content was decreased significantly in the SAH+TubA_H group (both P<0.05), while the improvement of the above indexes was not significant in the SAH+TubA_L group (both P>0.05). Compared with the sham group, the expression of eNOS was significantly decreased (P<0.01) and the expressions of iNOS and HDAC6 were significantly increased (P<0.05 and P<0.01, respectively) in the SAH group. Compared with the SAH group, the expression of eNOS was significantly increased, and iNOS and HDAC6 were significantly decreased in the SAH+TubA group (all P<0.05). Compared with the SAH group, the number of TUNEL positive cells was significantly decreased and the diameter of middle cerebral artery was significantly increased in the SAH+TubA group (both P<0.05) . CONCLUSIONS HDAC6 is mainly expressed in neurons and is up-regulated in the cerebral cortex at the early stage of SAH. TubA has protective effects on EBI and cerebral vasospasm in SAH rats by reducing brain edema and cell apoptosis in the early stage of SAH. In addition, its effect of reducing cerebral vasospasm may be related to regulating the expression of eNOS and iNOS.
Rats ; Male ; Animals ; Rats, Sprague-Dawley ; Subarachnoid Hemorrhage/drug therapy* ; Vasospasm, Intracranial/metabolism* ; Histone Deacetylase Inhibitors/therapeutic use* ; Neuroprotective Agents/therapeutic use* ; Histone Deacetylase 6/pharmacology* ; Apoptosis ; Brain Injuries/drug therapy*

Angiogenesis, a process by which the preexisting blood vasculature gives rise to new capillary vessels, is associated with a variety of physiologic and pathologic conditions. However, the molecular mechanism underlying this important process remains poorly understood. Here we show that histone deacetylase 6 (HDAC6), a microtubule-associated enzyme critical for cell motility, contributes to angiogenesis by regulating the polarization and migration of vascular endothelial cells. Inhibition of HDAC6 activity impairs the formation of new blood vessels in chick embryos and in angioreactors implanted in mice. The requirement for HDAC6 in angiogenesis is corroborated in vitro by analysis of endothelial tube formation and capillary sprouting. Our data further show that HDAC6 stimulates membrane ruffling at the leading edge to promote cell polarization. In addition, microtubule end binding protein 1 (EB1) is important for HDAC6 to exert its activity towards the migration of endothelial cells and generation of capillary-like structures. These results thus identify HDAC6 as a novel player in the angiogenic process and offer novel insights into the molecular mechanism governing endothelial cell migration and angiogenesis.
Anilides ; pharmacology ; Animals ; Cell Movement ; Cell Polarity ; Cells, Cultured ; Chick Embryo ; Chickens ; Endothelial Cells ; cytology ; Histone Deacetylase 6 ; Histone Deacetylases ; metabolism ; physiology ; Humans ; Hydroxamic Acids ; pharmacology ; Mice ; Microtubule-Associated Proteins ; metabolism ; physiology ; Neovascularization, Physiologic

OBJECTIVES: Neuropathic pain (NP) is a chronic pain caused by somatosensory neuropathy or disease, and genistein (Gen) might be a potential drug for the treatment of NP. Therefore, this study aims to investigate the effect of Gen on lipopolysaccharide (LPS)-induced inflammatory injury of dorsal root ganglion neuron (DRGn) in rats and the possible molecular mechanism. METHODS: The DRGn of 1-day-old juvenile rats were taken for isolation and culture. The DRGn in logarithmic growth phase were divided into a control group, a LPS group, a tubastatin hydrochloride (TSA)+LPS group, a Gen1+LPS group, a Gen2+LPS group, a Gen2+LPS+TSA group, a Gen2+pcDNA-histone deacetylase 6 (HDAC6)+LPS group, and a Gen2+pcDNA3.1+LPS group. The LPS group was treated with 1 μg/mL LPS for 24 h; the TSA+LPS group, the Gen1+LPS group, the Gen2+LPS group were treated with 5 μmol/L TSA, 5 μmol/L Gen, 10 μmol/L Gen respectively for 0.5 h, and then added 1 μg/mL LPS for 24 h; the Gen2+TSA+LPS group was treated with 10 μmol/L Gen and 5 μmol/L TSA for 0.5 h and then added 1 μg/mL LPS for 24 h; the Gen2+pcDNA-HDAC6+LPS group and the Gen2+pcDNA3.1+LPS group received 100 nmol/L pcDNA-HDAC6 and pcDNA3.1 plasmids respectively, and 24 h after transfection, 10 μmol/L Gen was pretreated for 0.5 h, and then added 1 μg/mL LPS for 24 h. Real-time RT-PCR was used to detect the HDAC6 mRNA expression in DRGn; CCK-8 method was used to detect cell viability of DRGn; flow cytometry was used to detect cell apoptosis of DRGn; ELISA was used to detect the levels of IL-1β, IL-6, and TNF-α in DRGn culture supernatant; Western blotting was used to detect the protein expression of HDAC6, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and NF-κB p65 in DRGn. RESULTS: Compared with the control group, the expression levels of HDAC6 mRNA and protein, the expression levels of TLR4 and MyD88 protein in DRGn of LPS group rats were significantly up-regulated, the ratio of p-NF-κB p65/NF-κB p65 was significantly increased, and the activity of DRGn was significantly decreased, the apoptosis rate was significantly increased, and the levels of IL-1β, IL-6 and TNF-α in the DRGn culture supernatant were significantly increased (all P<0.05). Compared with the LPS group, the expression levels of HDAC6 mRNA and protein, TLR4 and MyD88 protein expression levels in DRGn of the TSA+LPS group, the Gen1+LPS group, the Gen2+LPS group and the Gen2+TSA+LPS group were significantly down-regulated, the ratio of p-NF-κB p65/NF-κB p65 was significantly decreased, the activity of DRGn was significantly increased, the apoptosis rate was significantly decreased, and the levels of IL-1β, IL-6 and TNF-α in the DRGn culture supernatant were significantly decreased (all P<0.05), and the above changes were most obvious in the Gen2+TSA+LPS group. Compared with the Gen2+LPS group, the expression levels of HDAC6 mRNA and protein, TLR4 and MyD88 protein expression levels in DRGn of the Gen2+pcDNA-HDAC6+LPS group were significantly up-regulated, the ratio of p-NF-κB p65/NF-κB p65 was significantly increased, the activity of DRGn was significantly decreased, and the apoptosis rate was significantly increased, and the levels of IL-1β, IL-6 and TNF-α in the DRGn culture supernatant were significantly increased (all P<0.05). CONCLUSIONS Gen can alleviate LPS-induced DRGn inflammatory injury in rats, which might be related to down-regulating the expression of HDAC6 and further inhibiting the activation of TLR4/MyD88/NF-κB signaling pathway.
Animals ; Ganglia, Spinal ; Genistein/pharmacology* ; Histone Deacetylase 6/metabolism* ; Interleukin-6/metabolism* ; Lipopolysaccharides ; Myeloid Differentiation Factor 88 ; NF-kappa B/metabolism* ; Neurons/metabolism* ; RNA, Messenger ; Rats ; Toll-Like Receptor 4/metabolism* ; Tumor Necrosis Factor-alpha/metabolism*

OBJECTIVETo investigate the role of histone acetylation in regulating influenza virus replicative intermediate double-stranded RNA (dsRNA)-induced interleukin-6 (IL-6) expression in A549 cells.

METHODSA549 cells were treated with influenza virus replicative intermediate dsRNA, histone deacetylase (HDAC) inhibitor trichostatin A (TSA), or HADC small interfering RNA (siRNA). The changes in the cellular IL-6 promoter activities were detected by dual-luciferase assay, and IL-6 mRNA and protein expressions in the cells were determined using real-time RT-PCR and ELISA, respectively.

RESULTSInfluenza virus replicative intermediate dsRNA obviously up-regulated IL-6 expression in the cells. HDAC inhibitor TSA significantly enhanced the activity of IL-6 promoter and increased IL-6 mRNA expression in A549 cells, and HDAC3 may play an important role in this process. HDAC inhibitor TSA and DNMT inhibitor DAC showed no synergic effect in regulating IL-6 expression.

CONCLUSIONSInfluenza virus replicative intermediate dsRNA-induced IL-6 expression in A549 cells is regulated by histone acetylation.

Acetylation ; Cell Line, Tumor ; Gene Expression Regulation ; Histone Deacetylase Inhibitors ; pharmacology ; Histones ; metabolism ; Humans ; Interleukin-6 ; metabolism ; Orthomyxoviridae ; genetics ; metabolism ; Promoter Regions, Genetic ; RNA, Double-Stranded ; RNA, Messenger ; genetics ; RNA, Viral