Estradiol inhibits hyaluronic acid synthase 1 expression in human vascular smooth muscle cells

17β-Estradiol Inhibits Proliferation and Oxidative Stress in Vascular Smooth Muscle Cells by Upregulating BHLHE40 Expression

Background: Intimal hyperplasia is a major complication of restenosis after angioplasty. The abnormal proliferation and oxidative stress of vascular smooth muscle cells (VSMCs) are the basic pathological feature of neointimal hyperplasia. 17β-Estradiol can inhibit VSMCs proliferation and inflammation. However, it is still unclear whether and how 17β-Estradiol affects intimal hyperplasia.

Methods: The neointima hyperplasia was observed by hematoxylin/eosin staining. The expression of PCNA, cyclin D1, NOX1, NOX4 and p47^phox in neointima hyperplasia tissues and VSMCs was determined by qRT-PCR and Western blotting. MTS assay, cell counting and EdU staining were performed to detect cells proliferation. The oxidative stress was assessed by ROS staining.

Results: 17β-Estradiol suppressed carotid artery ligation-induced intimal hyperplasia, which is accompanied by an increase of BHLHE40 level. Furthermore, loss- and gain-of-function experiments revealed that BHLHE40 knockdown promotes, whereas BHLHE40 overexpression inhibits TNF-α-induced VSMC proliferation and oxidative stress. 17β-Estradiol inhibited TNF-α-induced VSMC proliferation and oxidative stress by promoting BHLHE40 expression, thereby suppressing MAPK signaling pathways. In addition, enforcing the expression of BHLHE40 leads to amelioration of intimal hyperplasia.

Conclusions: Our study demonstrates that 17β-Estradiol inhibits proliferation and oxidative stress in vivo and in vitro by promotion of BHLHE40 expression.

Antioxidative and Skin Protective Effects of Canarium subulatum Methanol Extract on Keratinocytes

Canarium subulatum is a traditional medical herb used in South Asia. Recently, the anti-inflammatory effects of C. subulatum methanol extract (Cs-ME) have been reported; however, the effect of Cs-ME on skin physiology has not yet been elucidated. Therefore, in this study, we evaluated the protective effect of Cs-ME on UV-induced skin aging and cell death as well as the reinforcing effect on the skin barrier. According to viable cell counting and MTT assays, Cs-ME significantly reduced UV-evoked HaCaT cell death. Cs-ME blocked reactive oxygen species (ROS) generation in UV-irradiated HaCaT cells and showed radical scavenging activity against DPPH and ABTS. In addition, H2O2-induced cell death was inhibited by Cs-ME, indicating that Cs-ME protects cells from UV-derived cell death through the suppression of ROS. PCR analysis revealed that Cs-ME diminished the expression of aging-related HYAL-1 and MMP-1 genes in UV-treated HaCaT cells. Elevated HYAL-1 and MMP-1 mRNA expression in H2O2-stimulated HaCaT cells was also decreased by Cs-ME, suggesting that Cs-ME exerts antiaging activity via the inhibition of ROS. Expression of skin barrier components including filaggrin and hyaluronic acid synthase-1 was increased by Cs-ME and was modulated by ERK/p38-AP-1 signaling. Collectively, our data show that Cs-ME has cytoprotective and antiaging activity based on antioxidant properties. Furthermore, Cs-ME exerts skin barrier protective ability by regulating the AP-1 signaling pathway. Therefore, Cs-ME has the potential for use as an ingredient in cosmetics to protect the skin from UV irradiation, prevent photoaging, and strengthen the skin barrier.

A modified flavonoid accelerates oligodendrocyte maturation and functional remyelination

Myelination delay and remyelination failure following insults to the central nervous system (CNS) impede axonal conduction and lead to motor, sensory and cognitive impairments. Both myelination and remyelination are often inhibited or delayed due to the failure of oligodendrocyte progenitor cells (OPCs) to mature into myelinating oligodendrocytes (OLs). Digestion products of the glycosaminoglycan hyaluronan (HA) have been implicated in blocking OPC maturation, but how these digestion products are generated is unclear. We tested the possibility that hyaluronidase activity is directly linked to the inhibition of OPC maturation by developing a novel modified flavonoid that functions as a hyaluronidase inhibitor. This compound, called S3, blocks some but not all hyaluronidases and only inhibits matrix metalloproteinase activity at high concentrations. We find that S3 reverses HA-mediated inhibition of OPC maturation in vitro, an effect that can be overcome by excess recombinant hyaluronidase. Furthermore, we find that hyaluronidase inhibition by S3 accelerates OPC maturation in an in vitro model of perinatal white matter injury. Finally, blocking hyaluronidase activity with S3 promotes functional remyelination in mice with lysolecithin-induced demyelinating corpus callosum lesions. All together, these findings support the notion that hyaluronidase activity originating from OPCs in CNS lesions is sufficient to prevent OPC maturation, which delays myelination or blocks remyelination. These data also indicate that modified flavonoids can act as selective inhibitors of hyaluronidase activity and can promote OPC maturation, making them excellent candidates to accelerate myelination or promote remyelination following perinatal and adult CNS insults.

Estrogen-Mediated MicroRNA-101-3p Expression Represses Hyaluronan Synthase 2 in Synovial Fibroblasts From Idiopathic Condylar Resorption Patients

PURPOSE

Idiopathic condylar resorption (ICR) is an aggressive form of osteoarthritis that is frequently observed in adolescent female patients. We hypothesized that an estrogen-mediated pathway may contribute to ICR development.

MATERIALS AND METHODS

An enzyme-linked immunosorbent assay was used to detect the levels of estradiol (E2) and hyaluronan in synovial fluid. Immunohistochemistry, real-time polymerase chain reaction, and Western blotting were used to detect the expression of microRNAs (miRNAs) and related genes after transfection of miRNA-101-3p mimics, inhibitor, or short interfering RNA into synovial fibroblasts. Dual-luciferase activity was determined to identify the direct effect of miRNA-101-3p on hyaluronan synthase 2 (HAS2). Linear regression analysis, the nonparametric Mann-Whitney U test, the Student t test, and 1-way analysis of variance were carried out to analyze the results of each group.

RESULTS

The relationship between hyaluronan and E2 was negatively correlated in synovial fluid (Pearson r = -0.3179, P = .0230). Among the screened miRNAs, miRNA-101-3p was the most overexpressed in ICR. E2 mostly upregulated the expression of miRNA-101-3p at a dose of 10 nmol/L 12 hours after transfection in synovial fibroblasts of patients with ICR. However, E2 induction of miRNA-101-3p expression was significantly repressed by estrogen receptor α interference (P = 0.0286). The dual-luciferase assay showed that miRNA-101-3p regulated the expression of HAS2 by directly targeting its 3' untranslated region.

CONCLUSIONS

We speculate that E2 regulates HAS2 expression by targeting miRNA-101-3p in synovial fibroblasts of patients with ICR. Thus, the E2-miRNA-101-3p-HAS2 pathway might play an important role in the pathogenesis of ICR.

Analysis of hyaluronic acid in the endometrium of women with polycystic ovary syndrome

Endometrium extracellular matrix provides a wide range of signals at different cellular levels, like cell death and proliferation, which can be important for regulating menses and reducing the proliferative processes. The objective of this study is to evaluate hyaluronic acid concentration, the enzymes of hyaluronic acid synthases in the endometrium of patients with polycystic ovary syndrome (PCOS) and eumenorrheic women. A total of 60 endometrial samples from 30 patients with PCOS and 30 women with regular menstrual cycles in the proliferative phase, attended at Gynecology Division of Clinical Hospital of the FMUSP (HC-USP). Profile determination and the concentration of hyaluronic acid was performed by the biochemical method of the fluorimetric assay (ELISA-like). Its location in the endometrial tissue as well as the dosage of enzymes synthases (HAS1, HAS2 and HAS3) was done by immunohistochemistry and western blotting. Statistical analyses were performed with one-way ANOVA, followed by the Bonferroni test. Regarding hyaluronic acid synthases, there was a higher HAS1 and HAS2 reactivity and lower HAS3 reactivity in the PCOS endometrium compared to women with regular menstrual cycles in the proliferative phase. We suggest that PCOS patients have different composition of hyaluronic acid in relation to a regular cycle in the proliferative phase.

New insights into arterial stiffening: does sex matter?

This review discusses sexual dimorphism in arterial stiffening, disease pathology interactions, and the influence of sex on mechanisms and pathways. Arterial stiffness predicts cardiovascular mortality independent of blood pressure. Patients with increased arterial stiffness have a 48% higher risk for developing cardiovascular disease. Like other cardiovascular pathologies, arterial stiffness is sexually dimorphic. Young women have lower stiffness than aged-matched men, but this sex difference reverses during normal aging. Estrogen therapy does not attenuate progressive stiffening in postmenopausal women, indicating that currently prescribed drugs do not confer protection. Although remodeling of large arteries is a protective adaptation to higher wall stress, arterial stiffening increases afterload to the left ventricle and transmits higher pulsatile pressure to smaller arteries and target organs. Moreover, an increase in aortic stiffness may precede or exacerbate hypertension, particularly during aging. Additional studies are needed to elucidate the mechanisms by which females are protected from arterial stiffness to provide insight into its mechanisms and, ultimately, therapeutic targets for treating this pathology.

Regulation of hyaluronan biosynthesis and clinical impact of excessive hyaluronan production

The tightly regulated biosynthesis and catabolism of the glycosaminoglycan hyaluronan, as well as its role in organizing tissues and cell signaling, is crucial for the homeostasis of tissues. Overexpression of hyaluronan plays pivotal roles in inflammation and cancer, and markedly high serum and tissue levels of hyaluronan are noted under such pathological conditions. This review focuses on the complexity of the regulation at transcriptional and posttranslational level of hyaluronan synthetic enzymes, and the outcome of their aberrant expression and accumulation of hyaluronan in clinical conditions, such as systemic B-cell cancers, aggressive breast carcinomas, metabolic diseases and virus infection.

The Development of a Novel Therapeutic Strategy to Target Hyaluronan in the Extracellular Matrix of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal diseases to affect humans, regardless of whether patients receive multimodal therapy (including surgery, radiotherapy, and chemotherapy). This resistance to intervention is currently considered to be caused by the desmoplastic change of the extracellular matrix (ECM) in PDAC tissues, which is characterized by the accumulation of cancer-associated fibroblasts, collagen, proteoglycan, and hyaluronan. Among these ECM components, hyaluronan has attracted interest because various studies have indicated that hyaluronan-rich PDAC is correlated with the progressive properties of cancer cells, both in experimental and clinical settings. Hence, the reduction of hyaluronan in cancer tissue may represent a novel therapeutic approach for PDAC. 4-methylumbelliferone (4-MU) is a derivative of coumarin that was reported to suppress the synthesis of hyaluronan in cultured human skin fibroblasts in 1995. As an additional study, our group firstly reported that 4-MU reduced the hyaluronan synthesis of mouse melanoma cells and exerted anti-cancer activity. Subsequently, we have showed that 4-MU inhibited liver metastasis in mice inoculated with human pancreatic cancer cells. Thereafter, 4-MU has been accepted as an effective agent for hyaluronan research and is expected to have clinical applications. This review provides an overview of the interaction between PDAC and hyaluronan, the properties of 4-MU as a suppressor of the synthesis of hyaluronan, and the perspectives of PDAC treatment targeting hyaluronan.

GPER activation ameliorates aortic remodeling induced by salt-sensitive hypertension

The mRen2 female rat is an estrogen- and salt-sensitive model of hypertension that reflects the higher pressure and salt sensitivity associated with menopause. We previously showed that the G protein-coupled estrogen receptor (GPER) mediates estrogenic effects in this model. The current study hypothesized that GPER protects against vascular injury during salt loading. Intact mRen2 female rats were fed a normal (NS; 0.5% Na(+)) or high-salt diet (HS; 4% Na(+)) for 10 wk, which significantly increased systolic blood pressure (149 ± 5 vs. 224 ± 8 mmHg;P< 0.001). Treatment with the selective GPER agonist G-1 for 2 wk did not alter salt-sensitive hypertension (216 ± 4 mmHg;P> 0.05) or ex vivo vascular responses to angiotensin II or phenylephrine (P> 0.05). However, G-1 significantly attenuated salt-induced aortic remodeling assessed by media-to-lumen ratio (NS: 0.43; HS+veh: 0.89; HS+G-1: 0.61;P< 0.05). Aortic thickening was not accompanied by changes in collagen, elastin, or medial proliferation. However, HS induced increases in medial layer glycosaminoglycans (0.07 vs. 0.42 mm(2);P< 0.001) and lipid peroxidation (0.11 vs. 0.51 mm(2);P< 0.01), both of which were reduced by G-1 (0.20 mm(2)and 0.23 mm(2); both P< 0.05). We conclude that GPER's beneficial actions in the aorta of salt-loaded mRen2 females occur independently of changes in blood pressure and vasoreactivity. GPER-induced attenuation of aortic remodeling was associated with a reduction in oxidative stress and decreased accumulation of glycosaminoglycans. Endogenous activation of GPER may protect females from salt- and pressure-induced vascular damage.

Localisation and endocrine control of hyaluronan synthase (HAS) 2, HAS3 and CD44 expression in sheep granulosa cells

The aim of the present study was to investigate the hormonal regulation of hyaluronan (HA) components in sheep granulosa cells. HA components are present in the reproductive tract and have a range of physical and signalling properties related to reproductive function in several species. First, abattoir-derived ovaries of sheep were used to determine the localisation of HA synthase (HAS) 1–3 and CD44 proteins in antral follicles. Staining for HAS1–3 and CD44 proteins was most intense in the granulosa layer. Accordingly, the expression of HAS2, HAS3 and CD44 mRNA was measured in cultured granulosa cells exposed to 0–50 ng mL–1 of 17β-oestradiol and different combinations of oestradiol, gonadotropins, insulin-like growth factor (IGF)-1 and insulin for 48–96 h (1 ng mL–1 FSH, 10 ng mL–1 insulin, 10 ng mL–1 IGF-1, 40 ng mL–1 E2 and 25 ng mL–1 LH.). mRNA expression was quantified by real-time polymerase chain reaction using a fold induction method. The results revealed that the hormones tested generally stimulated mRNA expression of the genes of interest in cultured granulosa cells. Specifically, oestradiol, when combined with IGF-1, insulin and FSH, stimulated HAS2 mRNA expression. Oestradiol and LH had synergistic effects in increasing HAS3 mRNA expression. In conclusion, we suggest that the hormones studied differentially regulate HAS2, HAS3 and CD44 in ovine granulosa cells in vitro. Further work is needed to address the signalling pathways involved.

Hyaluronan synthase 1: a mysterious enzyme with unexpected functions

Hyaluronan synthase 1 (HAS1) is one of three isoenzymes responsible for cellular hyaluronan synthesis. Interest in HAS1 has been limited because its role in hyaluronan production seems to be insignificant compared to the two other isoenzymes, HAS2 and HAS3, which have higher enzymatic activity. Furthermore, in most cell types studied so far, the expression of its gene is low and the enzyme requires high concentrations of sugar precursors for hyaluronan synthesis, even when overexpressed in cell cultures. Both expression and activity of HAS1 are induced by pro-inflammatory factors like interleukins and cytokines, suggesting its involvement in inflammatory conditions. Has1 is upregulated in states associated with inflammation, like atherosclerosis, osteoarthritis, and infectious lung disease. In addition, both full length and splice variants of HAS1 are expressed in malignancies like bladder and prostate cancers, multiple myeloma, and malignant mesothelioma. Interestingly, immunostainings of tissue sections have demonstrated the role of HAS1 as a poor predictor in breast cancer, and is correlated with high relapse rate and short overall survival. Utilization of fluorescently tagged proteins has revealed the intracellular distribution pattern of HAS1, distinct from other isoenzymes. In all cell types studied so far, a high proportion of HAS1 is accumulated intracellularly, with a faint signal detected on the plasma membrane and its protrusions. Furthermore, the pericellular hyaluronan coat produced by HAS1 is usually thin without induction by inflammatory agents or glycemic stress and depends on CD44–HA interactions. These specific interactions regulate the organization of hyaluronan into a leukocyte recruiting matrix during inflammatory responses. Despite the apparently minor enzymatic activity of HAS1 under normal conditions, it may be an important factor under conditions associated with glycemic stress like metabolic syndrome, inflammation, and cancer.

Normal enhanced liver fibrosis (ELF) values in apparently healthy subjects undergoing a health check-up and in living liver donors in South Korea

BACKGROUND

The enhanced liver fibrosis (ELF) value is a non-invasive serum marker used for assessing liver fibrosis in chronic liver disease. To use the ELF value for the purpose of screening the general population and selecting subpopulations at high risk, it is important to know the normal range of ELF values as a prerequisite.

AIMS

We aimed to define the normal range of ELF values by recruiting apparently healthy subjects and investigating factors influencing ELF values in subjects with minimal fibrotic burden.

METHODS

ELF values were determined in a cohort of healthy subjects who underwent a health check-up and in healthy living liver donors who were screened for transplantation. None of subjects suffered from chronic heart disease, diabetes mellitus, metabolic syndrome, hepatitis B, hepatitis C, or human immunodeficiency virus infection, systemic autoimmune disease or liver dysfunction.

RESULTS

Among 183 subjects analyzed, the normal ELF 5th through 95th percentile range was 5.95-8.73. Body mass index (P = 0.014) and male gender (P = 0.015) showed significant positive correlations with ELF value, whereas age did not. In multivariate linear regression analysis, platelet count was identified as the only independent factor influencing the ELF value (β=-0.006, P = 0.016). When considering the difference in ELF values between genders, the normal range of men was defined to be 6.72-8.93, this was slightly higher than that of women, 5.69-8.67.

CONCLUSIONS

We identified the normal range of ELF values and found that it can be significantly influenced by platelet count even in the healthy population.

Novel effects of adenosine receptors on pericellular hyaluronan matrix: implications for human smooth muscle cell phenotype and interactions with monocytes during atherosclerosis

Hyaluronan (HA) is responsive to pro-atherosclerotic growth factors and cytokines and is thought to contribute to neointimal hyperplasia and atherosclerosis. However, the specific function of the pericellular HA matrix is likely depend on the respective stimuli. Adenosine plays an important role in the phenotypic regulation of vascular smooth muscle cells (VSMC) and is thought to inhibit inflammatory responses during atherosclerosis. The aim of this study was to examine the regulation and function of HA matrix in response to adenosine in human coronary artery SMC (HCASMC). The adenosine receptor agonist NECA (10 μM) caused a strong induction of HA synthase (HAS)1 at 6 h and a weaker induction again after 24 h. Use of selective adenosine receptor antagonists revealed that adenosine A2(B) receptors (A2(B)R) mediate the early HAS1 induction, whereas late HAS1 induction was mediated via A2(A)R and A3R. The strong response after 6 h was mediated in part via phosphoinositide-3 kinase- and mitogen-activated protein kinase pathways and was inhibited by Epac. Functionally, NECA increased cell migration, which was abolished by shRNA-mediated knock down of HAS1. In addition to HA secretion, NECA also stimulated the formation of pronounced pericellular HA matrix in HCASMC and increased the adhesion of monocytes. The adenosine-induced monocyte adhesion was sensitive to hyaluronidase. In conclusion, the current data suggest that adenosine via adenosine A2(B)R and A2(A)R/A3R induces HAS1. In turn a HA-rich matrix is formed by HCASMC which likely supports the migratory HCASMC phenotype and traps monocytes/macrophages in the interstitial matrix.