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Publication
Journal: Immunobiology
August/26/2013
Abstract
This study tested the hypothesis that CD4(+)CD25(+)CD127(low) regulatory T (Treg) cells might induce immunosuppressive properties in apoptotic neutrophils. Treg cells are recognized as a major subset of immune cells possessing potent suppressive properties directed at T effector cells. However, Treg cells have recently been found to inhibit neutrophil function and promote their apoptosis. One of the mechanisms of action of Treg cells is the induction of other suppressor cell populations according to an infectious tolerance model. We showed that LPS-activated Treg cells promote generation of IL-10 and TGF-β1, inhibit IL-6 production by PMNs and induce the expression of heme oxygenase-1 (HO-1) and the suppressor of cytokine signaling 3 molecule (SOCS3). However, CD3/CD28-activated Treg cells were seen to promote TGF-β1 production, as well as IDO and HO-1 expression by PMNs. These findings suggest that Treg cells might play an important role in the direct control of innate immune responses through the induction of neutrophils with immunosuppressive properties that generate IL-10, TGF-β1, IDO and HO-1.
Publication
Journal: International Journal of Molecular Sciences
August/6/2015
Abstract
The mechanisms underlying the pathogenesis of idiopathic pulmonary fibrosis (IPF) involve multiple pathways, such as inflammation, epithelial mesenchymal transition, coagulation, oxidative stress, and developmental processes. The small GTPase, RhoA, and its target protein, Rho-kinase (ROCK), may interact with other signaling pathways known to contribute to pulmonary fibrosis. This study aimed to determine the beneficial effects and mechanisms of fasudil, a selective ROCK inhibitor, on bleomycin-induced pulmonary fibrosis in mice. Our results showed that the Aschcroft score and hydroxyproline content of the bleomycin-treated mouse lung decreased in response to fasudil treatment. The number of infiltrated inflammatory cells in the bronchoalveolar lavage fluid (BALF) was attenuated by fasudil. In addition, fasudil reduced the production of transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), alpha-smooth muscle actin (α-SMA), and plasminogen activator inhibitor-1 (PAI-1) mRNA and protein expression in bleomycin-induced pulmonary fibrosis. These findings suggest that fasudil may be a potential therapeutic candidate for the treatment of pulmonary fibrosis.
Publication
Journal: BMC Gastroenterology
October/4/2015
Abstract
BACKGROUND
Cirrhosis is a long-term consequence of chronic hepatic injury with fibrosis. No effective therapy is currently available for decompensated cirrhosis except liver transplantation. Hence, we investigated the effect of bone marrow-derived mesenchymal stem cells (BM-MSCs) on hepatic fibrosis in a thioacetamide (TAA)-induced cirrhotic rat model.
METHODS
The BM-MSCs were injected directly into the right liver lobe twice, at 6 and 8 weeks during the 12-week TAA administration, in thioacetamide (TAA)-induced cirrhotic rats model, and hepatic fibrosis was evaluated. At 12 weeks, the effect of BM-MSCs on hepatic fibrosis was analyzed histomorphologically using the Laennec fibrosis scoring system, and the collagen proportionate area was quantified. Cirrhosis-related factors, such as transforming growth factor β1 (TGF-β1), type 1 collagen (collagen-1), α-smooth muscle actin (α-SMA), and P-Smad3/Smad3 expression levels, were evaluated using real-time polymerase chain reaction and western blot assays.
RESULTS
According to the Laennec fibrosis scoring system, histological improvement was observed in hepatic fibrosis after BM-MSC treatment (P <0.01). The percentage of the collagen proportionate area decreased from 16.72 ± 5.51 to 5.06 ± 1.27 after BM-MSC treatment (P <0.01). The content of hepatic hydroxyproline was significantly lower in the BM-MSC treated group (46.25 ± 13.19) compared to the untreated cirrhotic group (85.81 ± 17.62; P <0.01). BM-MSC administration significantly decreased TGF-β1, collagen-1, and α-SMA expression in TAA-induced cirrhotic rats (P <0.01). We also confirmed P-Smad3/Smad3, downstream effectors of the TGF-β1 signaling pathway, and found that MSC transplantation inhibited Smad3 phosphorylation.
CONCLUSIONS
BM-MSC treatment attenuated hepatic fibrosis in rats with TAA-induced cirrhosis, raising the possibility of the clinical use of BM-MSCs in the treatment of cirrhosis.
Publication
Journal: American journal of physiology. Renal physiology
August/2/2016
Abstract
Oxidative stress is implicated in the pathogenesis of diabetic kidney injury. SS-31 is a mitochondria-targeted tetrapeptide that can scavenge reactive oxygen species (ROS). Here, we investigated the effect and molecular mechanism of mitochondria-targeted antioxidant peptide SS-31 on injuries in diabetic kidneys and mouse mesangial cells (MMCs) exposed to high-glucose (HG) ambience. CD-1 mice underwent uninephrectomy and streptozotocin treatment prior to receiving daily intraperitoneal injection of SS-31 for 8 wk. The diabetic mice treated with SS-31 had alleviated proteinuria, urinary 8-hydroxy-2-deoxyguanosine level, glomerular hypertrophy, and accumulation of renal fibronectin and collagen IV. SS-31 attenuated renal cell apoptosis and expression of Bax and reversed the expression of Bcl-2 in diabetic mice kidneys. Furthermore, SS-31 inhibited expression of transforming-growth factor (TGF)-β1, Nox4, and thioredoxin-interacting protein (TXNIP), as well as activation of p38 MAPK and CREB and NADPH oxidase activity in diabetic kidneys. In vitro experiments using MMCs revealed that SS-31 inhibited HG-mediated ROS generation, apoptosis, expression of cleaved caspase-3, Bax/Bcl-2 ratio, and cytochrome c (cyt c) release from mitochondria. SS-31 normalized mitochondrial potential (ΔΨm) and ATP alterations, and inhibited the expression of TGF-β1, Nox4, and TXNIP, as well as activation of p38 MAPK and CREB and NADPH oxidase activity in MMCs under HG conditions. SS-31 treatment also could reverse the reduction of thioredoxin (TRX) biologic activity and upregulate expression of thioredoxin 2 (TRX2) in MMCs under HG conditions. In conclusion, this study demonstrates a protective effect of SS-31 against HG-induced renal injury via an antioxidant mechanism in diabetic nephropathy.
Publication
Journal: Diabetologia
January/9/2014
Abstract
OBJECTIVE
Low-grade systemic inflammation and adipose tissue inflammatory macrophages are frequently detected in patients with obesity and type 2 diabetes. Whether inflammatory macrophages also increase in skeletal muscle of individuals with metabolic disorders remains controversial. Here, we assess whether macrophage polarisation markers in skeletal muscle of humans correlate with insulin sensitivity in obesity and type 2 diabetes.
METHODS
Skeletal muscle biopsies were obtained from individuals of normal weight and with normal glucose tolerance (NGT), and overweight/obese individuals with or without type 2 diabetes. Insulin sensitivity was determined by euglycaemic-hyperinsulinaemic clamps. Expression of macrophage genes was analysed by quantitative RT-PCR.
RESULTS
Gene expression of the inflammatory macrophage phenotype marker cluster of differentiation (CD)11c was higher in muscle of type 2 diabetes patients (p = 0.0069), and correlated with HbA1c (p = 0.0139, ρ = 0.48) and fasting plasma glucose (p = 0.0284, ρ = 0.43), but not after correction for age. Expression of TGFB1, encoding the anti-inflammatory marker TGF-β1, correlated inversely with HbA1c (p = 0.0095, ρ = -0.50; p = 0.0484, ρ = -0.50) and fasting plasma glucose (p = 0.0471, ρ = -0.39; p = 0.0374, ρ = -0.52) in two cohorts, as did HbA1c with gene expression of macrophage galactose-binding lectin (MGL) (p = 0.0425, ρ = -0.51). TGFB1 expression was higher in NGT individuals than in individuals with type 2 diabetes (p = 0.0303), and correlated with low fasting plasma insulin (p = 0.0310, ρ = -0.42). In exercised overweight/obese individuals, expression of genes for three anti-inflammatory macrophage markers, MGL (p = 0.0031, ρ = 0.71), CD163 (p = 0.0268, ρ = 0.57) and mannose receptor (p = 0.0125, ρ = 0.63), correlated with high glucose-disposal rate.
CONCLUSIONS
Muscle expression of macrophage genes reveals a link between inflammatory macrophage markers, age and high glycaemia, whereas anti-inflammatory markers correlate with low glycaemia and high glucose-disposal rate.
Publication
Journal: Journal of Pathology
September/8/2011
Abstract
Transforming growth factor β (TGF-β) is known to play a key role in intestinal fibrosis; however, the underlying mechanisms are not well understood. TGF-β signal transduction is through TGF-β receptors, including the TGF-β type 1 receptor. Most cell types contain a TGF-β type 1 receptor form known as activin receptor-like kinase 5 (ALK5), which propagates the signal to the nucleus through the phosphorylation of Smad2 and Smad3 proteins. Therefore, we assessed the effect of the disruption of TGF-β/ALK5/Smad signalling by an ALK5 inhibitor (SD-208) in two experimental animal models of intestinal fibrosis: anaerobic bacteria- and trinitrobenzensulphonic acid-induced colitis. In addition, isolated myofibroblasts were pretreated with SD-208 and exposed to recombinant TGF-β1. Finally, myofibroblasts were transfected with ALK5, Smad2, and Smad3-specific siRNA. Up-regulation of ALK5 and TIMP-1, phosphorylation of Smad2 and Smad3 proteins, and increased intestinal wall collagen deposition were found in both experimental animal models. These effects were decreased by SD-208. TGF-β1 treatment also induced phosphorylation of Smad2 and Smad3 and up-regulation of ALK5 protein, TIMP-1, and α2 type 1 collagen gene expression in isolated myofibroblasts. Again these effects were inhibited by SD-208. Also, ALK5, Smad2, and Smad3 siRNA abolished the induction of TIMP-1 and α2 type 1 collagen. Our findings provide evidence that the TGF-β/ALK5/Smad pathway participates in the pathogenesis of experimental intestinal fibrosis. These data show promise for the development of an effective therapeutic intervention in this condition.
Publication
Journal: American journal of physiology. Renal physiology
June/30/2011
Abstract
Posttranslational modification of proteins could regulate their multiple biological functions. Transforming growth factor-β receptor I and II (ALK5 and TGF-βRII), which are glycoproteins, play important roles in the renal tubular epithelial-mesenchymal transition (EMT). In the present study, we examined the role of core fucosylation of TGF-βRII and ALK5, which is regulated by α-1,6 fucosyltransferase (Fut8), in the process of EMT of cultured human renal proximal tubular epithelial (HK-2) cells. The typical cell model of EMT induced by TGF-β1 was constructed to address the role of core fucosylation in EMT. Core fucosylation was found to be essential for both TGF-βRII and ALK5 to fulfill their functions, and blocking it with Fut8 small interfering RNA greatly reduced the phosphorylation of Smad2/3 protein, caused the inactivation of TGF-β/Smad2/3 signaling, and resulted in remission of EMT. More importantly, even with high levels of expressions of TGF-β1, TGF-βRII, and ALK5, blocking core fucosylation also could attenuate the EMT of HK-2 cells. Thus blocking core fucosylation of TGF-βRII and ALK5 may attenuate EMT independently of the expression of these proteins. This study may provide new insight into the role of glycosylation in renal interstitial fibrosis. Furthermore, core fucosylation may be a novel potential therapeutic target for treatment of renal tubular EMT.
Publication
Journal: Journal of Dental Research
December/22/2010
Abstract
Recently identified as a key component of the murine periodontal ligament (PDL), periostin has been implicated in the regulation of collagen fibrillogenesis and fibroblast differentiation. We investigated whether periostin protein is expressed in the human PDL in situ and the mechanisms regulating periostin expression in PDL fibroblasts in vitro. With immunohistochemistry, periostin protein was identified in the PDL, with expression lower in teeth with reduced occlusal loading. In vitro application of uniaxial cyclic strain to PDL fibroblasts elevated periostin mRNA levels, depending on the age of the patient. Treatment with transforming growth factor-beta1 (TGF-β1) also significantly increased periostin mRNA levels, an effect attenuated by focal adhesion kinase (FAK) inhibition. FAK-null fibroblasts contained no detectable periostin mRNA, even after stimulation with cyclic strain. In conclusion, periostin protein is strongly expressed in the human PDL. In vitro, periostin mRNA levels are modulated by cyclic strain as well as TGF-β1 via FAK-dependent pathways.
Publication
Journal: OncoTargets and Therapy
November/12/2018
Abstract
UNASSIGNED
Temozolomide (TMZ) is commonly used for glioma chemotherapy. However, TMZ resistance limits the therapeutic effect of TMZ in glioma treatment. LncRNA-H19 acts as an oncogenic LncRNA in some types of cancers and has been reported to be up-regulated in glioma.
UNASSIGNED
In our present study, we established TMZ-resistant glioma cells (U-251TMZ and M059JTMZ) to explore the effect of H19 on the chemoresistance of glioma cells.
UNASSIGNED
We observed that the expression of H19 was significantly increased in U-251TMZ and M059JTMZ cells. Knockdown of H19 expression using specific shRNA in U-251TMZ and M059JTMZ led to decreased half maximal inhibitory concentration (IC50) values for TMZ and increased cell apoptosis rates, indicating that the silencing of H19 decreased chemoresistance of glioma cells to TMZ. In addition, silencing of H19 suppressed epithelial-mesenchymal transition (EMT) by increasing the expression of epithelial marker E-cadherin and decreasing the expression of mesenchymal marker Vimentin and ZEB1. Moreover, inducing EMT by TGF-β1 treatment led to increased IC50 values for TMZ and decreased cell apoptosis rates compared with TMZ+H19 shRNA group, suggesting that the induction of EMT counteracted the inhibitory effect of H19 shRNA on chemoresistance of glioma cells to TMZ. Furthermore, the reduced expression of H19 down-regulated the expression of β-Catenin and its downstream targets c-myc and Survivin in TMZ-treated glioma cells. Activation of Wnt/β-Catenin pathway by Licl treatment promoted EMT and enhanced chemoresistance to TMZ compared with TMZ+H19 shRNA group.
UNASSIGNED
Taken together, our data suggest that H19 decreased chemoresistance of glioma cells to TMZ by suppressing EMT via the inhibition of Wnt/β-Catenin pathway. Our study might represent a novel therapeutic target for TMZ-resistant glioma.
Publication
Journal: Molecular and Cellular Biology
July/24/2013
Abstract
Transforming growth factor β1 (TGF-β1) is a pleiotropic factor involved in the regulation of extracellular matrix (ECM) synthesis and remodeling. In search for novel genes mediating the action of TGF-β1 on vascular ECM, we identified the member of the lysyl oxidase family of matrix-remodeling enzymes, lysyl oxidase-like 4 (LOXL4), as a direct target of TGF-β1 in aortic endothelial cells, and we dissected the molecular mechanism of its induction. Deletion mapping and mutagenesis analysis of the LOXL4 promoter demonstrated the absolute requirement of a distal enhancer containing an activator protein 1 (AP-1) site and a Smad binding element for TGF-β1 to induce LOXL4 expression. Functional cooperation between Smad proteins and the AP-1 complex composed of JunB/Fra2 accounted for the action of TGF-β1, which involved the extracellular signal-regulated kinase (ERK)-dependent phosphorylation of Fra2. We furthermore provide evidence that LOXL4 was extracellularly secreted and significantly contributed to ECM deposition and assembly. These results suggest that TGF-β1-dependent expression of LOXL4 plays a role in vascular ECM homeostasis, contributing to vascular processes associated with ECM remodeling and fibrosis.
Publication
Journal: BMC Veterinary Research
June/27/2013
Abstract
BACKGROUND
There is no information on the effects of the breed, gender and age on the cellular content and growth factor (GF) release from equine pure-platelet rich plasma (P-PRP) and pure-platelet rich gel (P-PRG). The objectives of this study were: 1) to compare the cellular composition of P-PRP with whole blood and platelet poor plasma (PPP); 2) to compare the concentration of transforming GF beta 1 (TGF-β1) and platelet derived GF isoform BB (PDGF-BB) between P-PRP treated with non-ionic detergent (P-PRP+NID), P-PRG (activated with calcium gluconate -CG-), PPP+NID, PPP gel (PPG), and plasma and; 3) to evaluate and to correlate the effect of the breed, gender and age on the cellular and GF concentration for each blood component. Forty adult horses, 20 Argentinean Creole Horses (ACH) and, 20 Colombian Creole Horses (CCH) were included. Data were analyzed by parametric (i.e.: t-test, one way ANOVA) and non parametric (Kruskal-Wallis test, Wilcoxon test) tests. Correlation analysis was also performed by using the Spearman and Pearson tests. A p ≤ 0.05 was set as significant for all tests. All the blood components were compared for platelet (PLT), leukocyte (WBC), TGF-β1 and PDGF-BB concentrations. The effect of the breed, gender and age on these variables was analyzed. A P ≤ 0.05 was accepted as significant for all the tests.
RESULTS
PLT counts were 1.8 and 0.6 times higher in P-PRP than in whole blood and PPP, respectively; WBC counts were 0.5 and 0.1 times lower in P-PRP, in comparison with whole blood and PPP, respectively. TGF-β1 and PDGF-BB concentrations were 2.3 and 262 times higher, respectively, in P-PRG than in plasma, and 0.59 and 0.48 times higher, respectively, in P-PRG than in PPG. P-PRG derived from CCH females or young horses presented significantly (P < 0.001) higher PDGF-BB concentrations than P-PRG derived from ACH males or older horses.
CONCLUSIONS
Our results indicated that P-PRP obtained by a manual method was affected by intrinsic factors such as the breed, gender and age. Equine practitioners should be aware that cellular and GF release from P-PRP/P-PRG could change according with the intrinsic variables associated with a patient in particular.
Publication
Journal: Stem Cell Research and Therapy
February/8/2016
Abstract
BACKGROUND
Microparticles (MPs) derived from kidney-derived mesenchymal stem cells (KMSCs) have recently been reported to ameliorate rarefaction of peritubular capillaries (PTC) in ischemic kidneys via delivery of proangiogenic effectors. This study aimed to investigate whether KMSC-derived MPs show anti-fibrotic effects by ameliorating endothelial-to-mesenchymal transition (EndoMT) in human umbilical vein endothelial cells (HUVEC) in vitro and by preserving PTC in kidneys with unilateral ureteral obstruction (UUO) in vivo.
METHODS
MPs isolated from the supernatants of KMSC were co-cultured with HUVEC to assess their in vitro biologic effects on endothelial cells. Mice were treated with MPs via the tail vein after UUO injury to assess their anti-fibrotic and PTC sparing effects. Renal tubulointerstitial damage and inflammatory cell infiltration were examined with Masson's trichrome, F4/80 and α-smooth muscle actin (α-SMA) staining and PTC rarefaction index was determined by CD31 staining.
RESULTS
KMSC-derived MPs significantly ameliorated EndoMT and improved in vitro proliferation of TGF-β1 treated HUVEC. In vivo administration of KMSC-derived MPs significantly inhibited EndoMT of PTC endothelial cells and improved PTC rarefaction in UUO kidneys. Furthermore, administration of KMSC-derived MPs inhibited inflammatory cell infiltration as well as tubulointerstitial fibrosis in UUO mice as demonstrated by decreased F4/80 and α-SMA-positive cells and Masson's trichrome staining, respectively.
CONCLUSIONS
Our results suggest that KMSC-derived MPs ameliorate PTC rarefaction via inhibition of EndoMT and protect against progression of renal damage by inhibiting tubulointerstitial fibrosis.
Publication
Journal: Toxicology Letters
February/5/2014
Abstract
Conversion of hepatic stellate cells (HSCs) into hepatic myofibroblasts is a necessary event during the development of liver fibrosis. DNA methyltransferase 1 (DNMT1), which catalyzes DNA methylation and subsequently leads to the transcriptional repression of profibrotic genes, is selectively induced in myofibroblasts from diseased livers. Treatment of HSC with the DNA methylation inhibitor, 5-aza-2'-deoxycytidine (5-azadC), prevented TGF-β1-induced proliferation and alpha-smooth muscle actin (α-SMA) and collagen expression. 5-AzadC also rescued TGF-β1-induced suppression of Smad7 expression which occurs during HSC activation. Similarly, silencing the expression of the DNMT1 gene ameliorated the suppression of Smad7 expression by TGF-β1. In addition, DNMT1 inhibition, by 5-azadC or DNMT1 silencing, prevented the phosphorylation of Smad2 and Smad3. These studies suggest that epigenetic repression of Smad7 promotes the phosphorylation of Smad2 and Smad3 that may be an important molecular mechanism for perpetuated HSC activation and liver fibrosis.
Publication
Journal: Oncotarget
September/15/2016
Abstract
Regulatory B cells (Bregs) play a critical role in inflammation and autoimmune disease. We characterized the role of Bregs in the progression of gastric cancer. We detected an increase in Bregs producing IL-10 both in peripheral blood mononuclear cells (PBMCs) and in gastric tumors. Multicolor flow cytometry analysis revealed that a subset of CD19+CD24hiCD38hi B cells produces IL-10. Functional studies indicated that increased Bregs do not inhibit the proliferation of CD3+T cells or CD4+ helper T cells (Th cells). However, Bregs do suppress the secretion of IFN-γ and TNF-α by CD4+Th cells. CD19+CD24hiCD38hiBregs were also found to correlate positively with CD4+FoxP3+ regulatory T cells (Tregs). Neutralization experiments showed that Bregs convert CD4+CD25- effector T cells to CD4+FoxP3+Tregs via TGF-β1. Collectively, these findings demonstrate that increased Bregs play a immunosuppressive role in gastric cancer by inhibiting T cells cytokines as well as conversion to Tregs. These results may provide new clues about the underlying mechanisms of immune escape in gastric cancer.
Publication
Journal: European Journal of Heart Failure
May/20/2013
Abstract
OBJECTIVE
MicroRNAs (miRNAs) play a role in cardiac remodelling. MiR208a is essential for the expression of the genes involved in cardiac hypertrophy and fibrosis. The mechanism of regulation of miR208a involved in cardiac hypertrophy by mechanical stress is still unclear. We sought to investigate the mechanism of regulation of miR208a and the target gene of miR208a in cardiac cells by mechanical stretch.
RESULTS
Rat H9c2 cells (cardiac myoblasts) grown on a flexible membrane base were stretched via vacuum to 20% of maximum elongation at 60 cycles/min. Mechanical stretch significantly enhanced miR208a expression after 4 h of stretch. Exogenous addition of transforming growth factor-β1 (TGF-β1) increased miR208a expression, and pre-treatment with TGF-β1 antibody attenuated the miR208a expression induced by stretch. Mechanical stretch significantly increased endoglin and collagen I expression for 6-24 h. Exogenous addition of TGF-β1 and overexpression of miR208a up-regulated endoglin and collagen I expression, while antagomir208a and Smad3/4 inhibitor attenuated endoglin and collagen I expression induced by stretch. Mechanical stretch and TGF-β1 increased Smad3/4-DNA binding activity and miR208a promoter activity, and TGF-β1 antibody and Smad3/4 inhibitor decreased the Smad3/4-DNA binding activity and miR208a promoter activity induced by stretch.
CONCLUSIONS
Cyclic mechanical stretch enhances miR208a expression in cultured rat cardiac myoblasts. The stretch-induced miR208a is mediated by TGF-β1. Mir208a activates endoglin expression and may result in cardiac fibrosis.
Publication
Journal: Oncotarget
February/23/2017
Abstract
The majority of ovarian cancer patients relapse after surgical resection. Evidence is accumulating regarding the role of surgery in disseminating cancer cells; in particular anaesthesia may have an impact on cancer re-occurrence. Here, we have investigated the metastatic potential of volatile anaesthetics isoflurane, sevoflurane and desflurane on ovarian cancer cells. Human ovarian carcinoma cells (SKOV3) were exposed to isoflurane (2%), sevoflurane (3.6%) or desflurane (10.3%) for 2 hours. Metastatic related gene expression profiles were measured using the Tumour Metastasis PCR Array and qRT-PCR. Subsequently vascular endothelial growth factor A (VEGF-A), matrix metalloproteinase 11 (MMP11), transforming growth factor beta-1 (TGF-β1) and chemokine (C-X-C motif) receptor 2 (CXCR2) proteins expression were determined using immunofluorescent staining. The migratory capacities of SK-OV3 cells were assessed with a scratch assay and the potential role of CXCR2 in mediating the effects of volatile anaesthetics on cancer cell biology were further investigated with CXCR2 knockdown by siRNA. All three volatile anaesthetics altered expression of 70 out of 81 metastasic related genes with significant increases in VEGF-A, MMP-11, CXCR2 and TGF-β genes and protein expression with a magnitude order of desflurane (greatest), sevoflurane and isoflurane. Scratch analysis revealed that exposure to these anesthetics increased migration, which was abolished by CXCR2 knockdown. Volatile anaesthetics at clinically relevant concentrations have strong effects on cancer cell biology which in turn could enhance ovarian cancer metastatic potential. This work raises the urgency for further in vivo studies and clinical trials before any conclusions can be made in term of the alteration of clinical practice.
Publication
Journal: Biochimica et Biophysica Acta - General Subjects
February/19/2014
Abstract
Hydrogen sulfide (H2S) produced by cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) in the transsulfuration pathway of homocysteine plays a number of pathophysiological roles. Hyperhomocysteinemia is involved in kidney fibrosis. However, the role of H2S in kidney fibrosis remains to be defined. Here, we investigated the role of H2S and its acting mechanism in unilateral ureteral obstruction (UO)-induced kidney fibrosis in mice. UO decreased expressions of CBS and CSE in the kidney with decrease of H2S concentration. Treatment with sodium hydrogen sulfide (NaHS, a H2S producer) during UO reduced UO-induced oxidative stress with preservations of catalase, copper-zinc superoxide dismutase (CuZnSOD), and manganese superoxide dismutase (MnSOD) expression, and glutathione level. In addition, NaHS mitigated decreases of CBS and CSE expressions, and H2S concentration in the kidney. NaHS treatment attenuated UO-induced increases in levels of TGF-β1, activated Smad3, and activated NF-κB. This study provided the first evidence of involvement of the transsulfuration pathway and H2S in UO-induced kidney fibrosis, suggesting that H2S and its transsulfuration pathway may be a potential target for development of therapeutics for fibrosis-related diseases.
Publication
Journal: Experimental and Therapeutic Medicine
February/19/2017
Abstract
CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) are understood to maintain peripheral tolerance to self-antigens and inhibit antitumor immune responses. However, compelling evidence suggests that, Tregs provide no anti-inflammatory protection in the tumor microenvironment, but rather contribute to a T helper 17 (Th17)-driven pro-carcinogenic process. Using three-color flow cytometry, we evaluated the percentage of circulating CD4(+)CD25(+)FoxP3(+) Tregs in the peripheral blood of pancreatic carcinoma patients prior to and after chemotherapy [gemcitabine (GEM) alone, or GEM+oxaliplatin (GEMOX) or bevacizumab+capecitabine+radiotherapy (BEV+CAPE+RT)]. Correlations were sought between Treg counts and plasma levels of cytokines relevant to controlling the Treg/Th17 balance, i.e., interleukin (IL)-23, IL-17A, IL-6 and transforming growth factor β 1 (TGF-β1), as measured by ELISA and the clinical features of pancreatic cancer. Treg, IL-6 and TGF-β1 levels were higher in locally advanced and metastatic pancreatic carcinoma patients compared to controls. No parameter was correlated with disease stage except IL-6. IL-17A and TGF-β1 were significantly associated with increased risk of poor prognosis. IL-17A was positively correlated with IL-23. Treg and IL-6 levels decreased following GEM monochemotherapy, IL-17A levels decreased after GEMOX, and IL-6 levels were reduced subsequent to BEV+CAPE+RT treatment. IL-23, IL-17A and TGF-β1 levels were significantly lower in patients responding to chemotherapy (partial remission/stable disease) than in nonresponders to chemotherapy (progressive disease). These results suggest an impact of the Treg/Th17-balance in pancreatic carcinoma, highlighting the significance of TGF-β1 and IL-17A as potential prognostic and predictive indicators. Immunological changes induced by mono and/or combined chemotherapy indicate specific windows of opportunity for introducing integrative interventions on a new target in pancreatic cancer, i.e. IL-17A, possibly improving survival in this highly lethal disease.
Publication
Journal: Nature Structural and Molecular Biology
February/17/2015
Abstract
Eight integrin α-β heterodimers recognize ligands with an Arg-Gly-Asp (RGD) motif. However, the structural mechanism by which integrins differentiate among extracellular proteins with RGD motifs is not understood. Here, crystal structures, mutations and peptide-affinity measurements show that αVβ6 binds with high affinity to a RGDLXXL/I motif within the prodomains of TGF-β1 and TGF-β3. The LXXL/I motif forms an amphipathic α-helix that binds in a hydrophobic pocket in the β6 subunit. Elucidation of the basis for ligand binding specificity by the integrin β subunit reveals contributions by three different βI-domain loops, which we designate specificity-determining loops (SDLs) 1, 2 and 3. Variation in a pair of single key residues in SDL1 and SDL3 correlates with the variation of the entire β subunit in integrin evolution, thus suggesting a paradigmatic role in overall β-subunit function.
Publication
Journal: Clinical and Experimental Pharmacology and Physiology
July/28/2011
Abstract
1. Metformin is one of the most commonly used drugs for the treatment of Type 2 diabetes. Accumulating evidence suggests that metformin also has cardioprotective effects. In the present study, we investigated the cardioprotective effects of metformin and the mechanisms involved. 2. A rat model of chronic heart failure was established by permanent left coronary artery occlusion. Heart failure rats were randomly divided into four groups: (i) a saline-treated group given 4 mL/kg day via intragastric gavage; (ii) a metformin-treated group, given 100 mg/kg metformin once daily via intragastric gavage; (iii) a group treated with 5 mg/kg 5'-aminoimidazole-4-carboxyamide-ribonucleoside (AICAR), an AMP-activated protein kinase (AMPK) agonist, every second day; and (iv) a group treated with 100 mg/kg per day metformin + 20 mg/kg, i.p., compound C (an AMPK antagonist). After 4 weeks treatment, echocardiography was used to assess left ventricular (LV) dimensions and function. Expression of AMPK, endothelial nitric oxide synthase (eNOS) and transforming growth factor (TGF)-β1 was determined by reverse transcription-polymerase chain reaction and western blot analysis. 3. Metformin administration significantly improved cardiac function and LV remodelling, as evidenced by increases in LV systolic pressure and LV ejection fraction and decreases in LV end-diastolic diameter and LV end-systolic diameter. These beneficial effects of metformin were associated with increased AMPK and eNOS phosphorylation, as well as reductions in insulin, TGF-β1, basic fibroblast growth factor and tumour necrosis factor-α levels in the circulation and/or myocardium. 4. The results indicate that chronic low-dose metformin confers significant cardioprotective effects against chronic heart failure by activating the AMPK-eNOS pathway.
Publication
Journal: Lasers in Medical Science
December/9/2013
Abstract
The aim of this study was to examine the effect of low-level laser therapy (LLLT) on the cell viability and the expression of hypoxia-inducible factor-1s (HIF-1s), bone morphogenic protein-2 (BMP-2), osteocalcin, type I collagen, transforming growth factor-β1 (TGF-β1), and Akt in hypoxic-cultured human osteoblasts. Human fetal osteoblast cells (cell line 1.19) were cultured under 1 % oxygen tension for 72 h. Cell cultures were divided into two groups. At the experimental side, low-level laser (808 nm, GaAlAs diode) was applied at 0, 24, and 48 h. After irradiation, each cell culture was incubated 24 h more under hypoxia. Total energy was 1.2, 2.4, and 3.6 J/cm(2), respectively. Non-irradiated cultures served as controls. Comparisons between the two groups were analyzed by t test; a p value <0.05 was considered statistically significant. Hypoxia resulted in a decrease in the expression of type I collagen, osteocalcin, and TGF-β1 (p < 0.001, p < 0.001, and p < 0.01, respectively). Cell viability and BMP-2 expression were not decreased by hypoxic condition. On the other hand, LLLT on hypoxic-cultured osteoblast promoted the expression of BMP-2, osteocalcin, and TGF-β1 (p < 0.05, p < 0.01, and p < 0.001, respectively). Cell proliferation was also increased time-dependently. However, hypoxia decreased in type I collagen expression (p < 0.001), and LLLT did not affect type I collagen expression in hypoxic-cultured osteoblasts. Furthermore, LLLT inhibited HIF-1 and Akt expression in hypoxic conditioned osteoblasts. We concluded that LLLT induces the expression of BMP-2, osteocalcin, and TGF- β1 in 1 % hypoxic-cultured human osteoblasts.
Publication
Journal: Nature Cell Biology
March/28/2018
Abstract
Activation of metastatic reprogramming is critical for tumour metastasis. However, more detailed knowledge of the underlying mechanism is needed to enable targeted intervention. Here, we show that paraspeckle component 1 (PSPC1), identified in an aberrant 13q12.11 locus, is upregulated and associated with poor survival in patients with cancer. PSPC1 promotes tumorigenesis, epithelial-to-mesenchymal transition (EMT), stemness and metastasis in multiple cell types and in spontaneous mouse cancer models. PSPC1 is the master activator for transcription factors of EMT and stemness and accompanies c-Myc activation to facilitate tumour growth. PSPC1 increases transforming growth factor-β1 (TGF-β1) secretion through an interaction with phosphorylated and nuclear Smad2/3 to potentiate TGF-β1 autocrine signalling. Moreover, PSPC1 acts as a contextual determinant of the TGF-β1 pro-metastatic switch to alter Smad2/3 binding preference from tumour-suppressor to pro-metastatic genes. Having validated the PSPC1-Smads-TGF-β1 axis in various cancers, we conclude that PSPC1 is a master activator of pro-metastatic switches and a potential target for anti-metastasis drugs.
Publication
Journal: Carcinogenesis
March/23/2016
Abstract
Epigenetic changes through altered DNA methylation have been implicated in critical aspects of tumor progression, and have been extensively studied in a variety of cancer types. In contrast, our current knowledge of the aberrant genomic DNA methylation in tumor-associated fibroblasts (TAFs) or other stromal cells that act as critical coconspirators of tumor progression is very scarce. To address this gap of knowledge, we conducted genome-wide DNA methylation profiling on lung TAFs and paired control fibroblasts (CFs) from non-small cell lung cancer patients using the HumanMethylation450 microarray. We found widespread DNA hypomethylation concomitant with focal gain of DNA methylation in TAFs compared to CFs. The aberrant DNA methylation landscape of TAFs had a global impact on gene expression and a selective impact on the TGF-β pathway. The latter included promoter hypermethylation-associated SMAD3 silencing, which was associated with hyperresponsiveness to exogenous TGF-β1 in terms of contractility and extracellular matrix deposition. In turn, activation of CFs with exogenous TGF-β1 partially mimicked the epigenetic alterations observed in TAFs, suggesting that TGF-β1 may be necessary but not sufficient to elicit such alterations. Moreover, integrated pathway-enrichment analyses of the DNA methylation alterations revealed that a fraction of TAFs may be bone marrow-derived fibrocytes. Finally, survival analyses using DNA methylation and gene expression datasets identified aberrant DNA methylation on the EDARADD promoter sequence as a prognostic factor in non-small cell lung cancer patients. Our findings shed light on the unique origin and molecular alterations underlying the aberrant phenotype of lung TAFs, and identify a stromal biomarker with potential clinical relevance.
Publication
Journal: DMM Disease Models and Mechanisms
September/7/2014
Abstract
Transforming growth factor (TGF)-β1 and TGF-β3 have been reported to exert differential effects on wound healing, and possibly even account for tissue-specific differences in scar formation. Scarring is particularly detrimental in the vocal fold mucosa (VFM), where destruction of the native extracellular matrix causes irreparable biomechanical changes and voice impairment. Here, in a series of in vitro and in vivo experiments, we identified differences in TGF-β1 and TGF-β3 transcription and immunolocalization to various cell subpopulations in naïve and injured rat VFM, compared with oral mucosa (which undergoes rapid healing with minimal scar) and skin (which typically heals with scar). Treatment of cultured human vocal fold fibroblasts with TGF-β3 resulted in less potent induction of profibrotic gene transcription, extracellular matrix synthesis and fibroblast-myofibroblast differentiation, compared with treatment with TGF-β1 and TGF-β2. Finally, delivery of exogenous TGF-β3 to rat VFM during the acute injury phase modulated the early inflammatory environment and reduced eventual scar formation. These experiments show that the TGF-β isoforms have distinct roles in VFM maintenance and repair, and that TGF-β3 redirects wound healing to improve VFM scar outcomes in vivo.
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