Effect of tanshinone IIA in an in vitro model of Graves’ orbitopathy

PURPOSE: We investigated the therapeutic effect of nontoxic concentrations of tanshinone IIA (TanIIA) from Salvia miltiorrhiza in primary cultures of orbital fibroblasts from Graves' orbitopathy (GO). METHODS: The effect of TanIIA on IL-1β-induced proinflammatory cytokine (IL-6, IL-8, MCP-1) expression was determined by real-time PCR. Antioxidant activity was investigated by measuring intracellular reactive oxygen species (ROS) generation stimulated by cigarette smoke extract (CSE) and heme oxygenase-1 (HO-1) expression. To evaluate antiadipogenic activity, fibroblasts were subjected to a differentiation protocol, including peroxisome proliferator activator gamma (PPARγ) agonist, for 10 days, and exposed to TanIIA during adipocyte differentiation. Differentiated cells were stained with Oil Red O, and the expression of adipogenesis-related factors, PPARγ, and CCAAT-enhancer-binding proteins (C/EBP) α and β were determined by Western blot. RESULTS: Expression of IL-6, IL-8, and MCP-1 mRNA was inhibited by TanIIA pretreatment in a dose-dependent manner in GO orbital fibroblasts (P < 0.05). Tanshinone IIA decreased CSE- or H2O2-induced ROS levels in a dose-dependent manner and upregulated HO-1 protein expression in a time- and dose-dependent manner (P < 0.001). Treatment of orbital fibroblasts with TanIIA increased phosphorylated extracellular signal-regulated kinase (pERK), and an ERK inhibitor significantly blocked TanIIA-induced HO-1 upregulation. Adipogenesis was inhibited by TanIIA in a dose-dependent manner (P < 0.001), as evidenced by Oil Red O stain and decreased PPARγ and C/EBPα expression in Western blot analysis. CONCLUSIONS: Our study results suggest that TanIIA possesses significant anti-inflammatory, antioxidant, and antiadipogenic effects in primary orbital fibroblasts. These results provide the basis for further study of the potential use of TanIIA to treat GO. Tanshinone IIA showed significant anti-inflammatory, antioxidant, and antiadipogenic effects in primary orbital fibroblasts from Graves' orbitopathy patients. These results provide the basis for further study of the potential use of tanshinone IIA to treat Graves' orbitopathy.ope

Pentoxifylline attenuates methionine- and choline-deficient-diet-induced steatohepatitis by suppressing TNF-α expression and endoplasmic reticulum stress.

BACKGROUND: Pentoxifylline (PTX) anti-TNF properties are known to exert hepatoprotective effects in various liver injury models. The aim of this study was to investigate whether PTX has beneficial roles in the development of methionine- and choline-deficient-(MCD-) diet-induced NAFLD SD rats in vivo and TNF-α-induced Hep3B cells in vitro. METHODS: SD Rats were classified according to diet (chow or MCD diet) and treatment (normal saline or PTX injection) over a period of 4 weeks: group I (chow + saline, n = 4), group II (chow + PTX), group III (MCD + saline), and group IV (MCD + PTX). Hep3B cells were treated with 100 ng/ml TNF-α (24 h) in the absence or presence of PTX (1 mM). RESULTS: PTX attenuated MCD-diet-induced serum ALT levels and hepatic steatosis. In real-time PCR and western blotting analysis, PTX decreased MCD-diet-induced TNF-alpha mRNA expression and proapoptotic unfolded protein response by ER stress (GRP78, p-eIF2, ATF4, IRE1α, CHOP, and p-JNK activation) in vivo. PTX (1 mM) reduced TNF-α-induced activation of GRP78, p-eIF2, ATF4, IRE1α, and CHOP in vitro. CONCLUSION: PTX has beneficial roles in the development of MCD-diet-induced steatohepatitis through partial suppression of TNF-α and ER stress.ope

4-Methylumbelliferone suppresses hyaluronan and adipogenesis in primary cultured orbital fibroblasts from Graves' orbitopathy

Purpose: In Graves' orbitopathy (GO), hyaluronan secreted by orbital fibroblasts contributes to orbital tissue expansion. The goal of this research was to evaluate the potential benefit of 4-methylumbelliferone (4-MU), a hyaluronan synthase (HAS) inhibitor, in primary cultured orbital fibroblasts from Graves' orbitopathy. Methods: We assessed the viability of orbital fibroblasts using a live/dead cell assay. Hyaluronan synthesis was evaluated by enzyme-linked immunosorbent assay (ELISA) and quantitative real-time PCR (qPCR). Adipogenesis was assessed by Oil Red O staining and qPCR of adipogenic transcription factors. Results: In orbital fibroblasts treated with 4-MU (up to 1000 μM), cell viability was preserved by 90%. 4-MU significantly inhibited HAS gene expression and hyaluronan production (*P < 0.05). With respect to adipogenesis, 4-MU suppressed the accumulation of lipids and reduced the number of adipocytes, while decreasing expression of adipogenic transcription factors. Conclusions: 4-MU represents a promising new therapeutic agent for GO based on its ability to inhibit hyaluronan production and adipogenesis, without decreasing cell viability.restrictio

Cigarette smoke extract-induced adipogenesis in Graves' orbital fibroblasts is inhibited by quercetin via reduction in oxidative stress

Cigarette smoking is known to aggravate Graves' orbitopathy (GO) severity by enhancing adipogenesis. We investigated the effect of quercetin, an antioxidant, on adipocyte differentiation induced by cigarette smoke extract (CSE) in primary cultured orbital fibroblasts (OFs) from GO patients. Freshly prepared CSE was added to the cells and H(2)O(2) was used as a positive control. Intracellular reactive oxygen species (ROS) generation and adipogenesis were measured. The expressions of proteins peroxisome proliferator-activated receptor (PPAR) γ, CCAAT-enhancer-binding proteins (C/EBP) α and β, and heme oxygenase-1 (HO-1), an antioxidant enzyme, were examined during adipogenic differentiation. In result, CSE and H(2)O(2) dose-dependently stimulated intracellular ROS production in normal and Graves' OFs. The effect of 2% CSE was similar to that of 10 μM H(2)O(2); both concentrations were noncytotoxic and were used throughout the experiment. Quercetin pretreatment reduced the ROS generation stimulated by either CSE or H(2)O(2) in preadipocyte OFs. CSE and H(2)O(2) stimulated adipocyte differentiation in cultured OFs. The addition of quercetin (50 or 100 μM) suppressed adipogenesis. Quercetin also suppressed ROS generation in differentiating OFs during adipogenesis stimulated by CSE and H(2)O(2). Additionally, the expressions of PPARγ, C/EBPα, and C/EBPβ proteins were reduced in the quercetin-treated OFs. Quercetin also reduced the CSE- and H(2)O(2)-induced upregulation of ROS and HO-1 protein in differentiated OFs and preadipocyte OFs. As shown in this study, quercetin inhibited adipogenesis by reducing ROS in vitro, supporting the use of quercetin in the treatment of GO.ope

Autophagy is involved in the initiation and progression of Graves' orbitopathy

BACKGROUND: Differentiation of orbital fibroblasts into mature adipocytes and subsequent accumulation of adipose tissue has been shown in the progression of Graves' orbitopathy (GO). Autophagy is involved in adipogenesis, but little is known about the role of autophagy in the initiation and progression of GO. The aim of this study is to investigate the role of autophagy in the pathogenesis of GO. METHODS: Orbital adipose/connective tissue explants from patients with GO and from normal subjects, as well as isolated orbital fibroblasts, were analyzed. Adipogenesis was induced using differentiating medium with or without hydrogen peroxide, and autophagy was manipulated using bafilomycin A1 and Atg5-targeted short hairpin RNA (shRNA). Autophagosomes were identified by electron microscopy. Expression of autophagy-related genes and adipogenesis-related transcription factors were analyzed by real time reverse transcription-polymerase chain reaction and/or Western blot analysis. Lipid droplet accumulation was examined by Oil Red O staining. RESULTS: Autophagic vacuoles were more abundant in GO cells than in non-GO cells (p<0.05). Expression of autophagy-related genes was significantly higher in GO tissues and cells than in their non-GO counterparts, respectively. Interleukin-1β increased LC3-II, p62, and Atg7 protein in GO cells. Autophagosome accumulation was shown at day 4 of adipogenesis and decreased by day 10, along with lipid droplet formation. Expression of LC3 and p62 proteins increased within 48 hours of differentiation and diminished gradually from day 4 to 10. Bafilomycin A1 treatment and Atg5 knockdown by shRNA inhibited lipid droplet accumulation and suppressed expression of adipogenic markers. CONCLUSIONS: Autophagy was increased in GO tissue and cells compared to non-GO tissue and cells, suggesting that autophagy plays a role in GO pathogenesis. Autophagy manipulation may be a therapeutic target for GO.ope

Decreased endothelial progenitor cells and increased serum glycated albumin are independently correlated with plaque-forming carotid artery atherosclerosis in type 2 diabetes patients without documented ischemic disease.

BACKGROUND: The aim of the present study was to investigate the serum levels of endothelial progenitor cells (EPCs) in type 2 diabetic patients without documented ischemic disease and the association between EPCs and atherosclerotic plaque formation in the carotid artery. METHODS AND RESULTS: A clinic-based, prospective study of type 2 diabetic patients was conducted. A total of 73 subjects were enrolled in this study after cardiac magnetic resonance imaging and ankle-brachial index measurements to exclude patients with ischemic disease. Plaque formation in the carotid artery was measured on ultrasonography. Circulating EPCs (CD34(+)/CD133(+)/CD309(+) cells) were counted on flow cytometry. Compared to subjects without carotid artery plaques, patients with plaques were significantly older (P=0.006) and had decreased EPC count (P=0.027). Serum glycated albumin (GA) level and the GA/glycated hemoglobin ratio tended to decrease in patients with plaques (P=0.091 and 0.067, respectively). Other cardiovascular disease risk factors were not significantly different between the 2 groups. On binary logistic regression analysis old age, low EPC count, and high serum GA level were independently correlated with carotid artery plaque formation. CONCLUSIONS: EPC count and serum GA level appear to be a protective and an aggravating factor for endothelial damage, respectively, and therefore, a reduced EPC count or an increased GA level results in atherosclerotic plaque formation in type 2 diabetic patients.ope

Association between EPCs count and rate of coronary revascularization in asymptomatic type 2 diabetic patients

Coronary arterial disease (CAD) is common in diabetic patients, and endothelial progenitor cells (EPCs) are considered a surrogate marker for CAD, but controversies regarding this issue still remain. We investigated the potential clinical role of EPCs during coronary screening in asymptomatic type 2 diabetic patients screened with cardiovascular magnetic resonance (CMR). A total of 100 asymptomatic type 2 diabetic subjects (51 men and 49 women) were enrolled. Clinical and laboratory parameters, including EPCs (CD34(+)/CD133(+)/VEGFR-2(+)) count, were evaluated and CMR was performed. A total of 51 patients [silent myocardial infarction (n = 3), inducible ischemia (n = 11), suspected CAD (n = 37)] had abnormal finding on CMR. Of the 20 patients who later underwent invasive coronary angiography, 8 were treated with revascularization. Fifty-one subjects with abnormal finding on CMR were divided into two groups [subjects with revascularization (group I, n = 8) vs. without revascularization (group II, n = 43)]. Group I had a significantly increased EPCs level than group II (833 vs. 415, P = 0.027). Multivariate logistic regression analysis revealed that an increased EPCs level (OR = 1.003, P = 0.024) and a high body-mass index (OR = 1.907, P = 0.028) were independently correlated with revascularization. In our study, increased EPCs count is associated with performing revascularization in asymptomatic type 2 diabetic patients, and that increased EPCs count can provide clinically important information while performing intervention.ope