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Publication
Journal: Journal of Biomedical Science
May/24/2006
Abstract
A novel culture system included a self-designed bi-layer 3-D collagen scaffold with different pore size on both sides and specific culture media for different culture stages. This skin equivalent culture model provides a new investigating system to study the role of extracellular matrix and growth factors including epidermal growth factor (EGF), keratinocyte growth factor (KGF), transforming growth factor beta 1 (TGF-beta1), in the cell-cell and cell-matrix interactions. Keratinocytes were seeded onto the dermal equivalent and incubated under submerged condition for 5 days then proceeding to air-liquid interface cultured either with or without EGF addition. In this study, EGF has a positive effect on the keratinocyte migration and proliferation in the submerged stage. However, when 10 ng per ml of EGF was continual added in the air-lifted stage, a less organized and thin differentiated keratinocyte layers were found. Continual 10 ng per ml of EGF addition in the air-lifted stage resulted in uneven cell-matrix interface, and disorganization of the suprabasal layers. On the contrary, in the air-lifted stage without excess EGF, the epithelium cells will stratify, differentiate, and form an epidermis completed with basal, spinous, granular, and cornified layers. The results showed that time scale modulation of EGF on keratinocyte cell behavior depend on the expression of paracrine or autocrine growth factors (e.g. KGF and TGF-beta1).
Publication
Journal: Molecular and Cellular Endocrinology
August/17/2014
Abstract
CPS-2, a Cordyceps sinensis polysaccharide, has been demonstrated to have significant therapeutic activity against chronic renal failure. However, little is known about the underlying molecular mechanism. In this study, we found that CPS-2 could inhibit PDGF-BB-induced human mesangial cells (HMCs) proliferation in a dose-dependent manner. In addition, CPS-2 notably suppressed the expression of α-SMA, PDGF receptor-beta (PDGFRβ), TGF-β1, and Smad 3 in PDGF-BB-treated HMCs. Furthermore, PDGF-BB-stimulated ERK activation was significantly inhibited by CPS-2, and this inhibitory effect was synergistically potentiated by U0126. CPS-2 could prevent the PDGFRβ promoter activity induced by PDGF-BB, and return expression of PDGFRβ, TGF-β1, and TGFβRI to normal levels while cells were under PDGFRβ and ERK silencing conditions and transfected with DN-ERK. Taken together, these findings demonstrated that CPS-2 reduces PDGF-BB-induced cell proliferation through the PDGF/ERK and TGF-β1/Smad pathways, and it may have bi-directional regulatory effects on the PDGF/ERK cellular signaling pathway.
Publication
Journal: International Immunopharmacology
January/23/2013
Abstract
The present study investigated the effects of the anthraquinone derivative (O,O'-bis-(3'-iodopropyl)-1,4-dihidroxyanthraquinone - DIPDHAQ), mitoxantrone analog, in an experimental autoimmune encephalomyelitis (EAE) model. The results showed that DIPDHAQ treatment improved the clinical signs of the disease (n=10; vehicle: 3.8 ± 0.3; DIPDHAQ: 1.4 ± 0.9). The improvement was associated with a decrease of inflammatory cells, demyelination, IL-17, IFN-γ, IL-12p40, IL-6, TGF-β, CCL5 and CCL20 levels in the spinal cord. DIPDHAQ presented a low cytotoxicity when in vitro assays were performed. Therefore, the findings suggest a major role for DIPDHAQ in multiple sclerosis, disease characterized as an autoimmune inflammatory disorder against myelin proteins of the brain and spinal cord. The attenuation of inflammation and consequently improvement of clinical signs, involving a decrease of pro-inflammatory cytokines and the low cytotoxicity of DIPDHAQ, suggest that this compound could be used as an alternative treatment for autoimmune diseases in the central nervous system.
Publication
Journal: Bone Marrow Transplantation
February/15/2005
Abstract
Pulmonary fibrosis is a severe complication associated with bis-chloronitrosourea (BCNU) therapy. However, the pathogenetic mechanism has never been well investigated. We report here a 26-year-old female with diffuse large B-cell lymphoma who died of severe pulmonary fibrosis 81 days after the administration of high-dose BCNU (600 mg/m2). Thoracoscopic wedge resection of left upper lung performed 10 days before patient's death showed severe pulmonary fibrosis with prominent hyperplasia of alveolar macrophages and type II pneumocytes. We further used immunohistochemistry (IHC) to examine the relative role of platelet-derived growth factor-B (PDGF-B), insulin-like growth factor I (IGF-I), transforming growth factor-beta1 (TGF-beta1) and cyclooxygenase-2 (COX-2) in the pathogenesis of BCNU-related pulmonary fibrosis. Strong expressions of PDGF-B and IGF-1 on alveolar macrophages and type II pneumocytes were clearly demonstrated, but in contrast, the expressions of TGF-beta1 and COX-2 were almost undetectable. In conclusion, pulmonary fibrosis can develop early and progress rapidly after the administration of high-dose BCNU. The markedly increased expression of fibrogenic factors PDGF-B and IGF-1 on hyperplastic alveolar macrophages and hyperplastic type II pneumocytes may play an important role in the fibrogenesis of this disease. These novel findings may offer specific therapeutic targets in the treatment of BCNU-associated pulmonary fibrosis.
Publication
Journal: Chinese Journal of Pathology
September/23/2004
Abstract
OBJECTIVE
To investigate the effects of PDGF on the proliferation of rat HSC, its gene expression of collagens and the autocrine excretion of PDGF in vitro.
METHODS
(3)H-TdR incorporation was used to estimate the DNA synthesis elicited by PDGF, TGF-beta1 and EGF in HSC cultured in an absolutely serum-free medium. Northern blot was employed to detect the levels of mRNA expressions of type I and III procollagens and PDGF induced by PDGF added in the same medium for HSC.
RESULTS
Both PDGF and EGF enabled to stimulate the proliferation of HSC in a dose-dependent manner, and the effect of the former was stronger. The proliferation was dose-dependently increased in PDGF and EGF with a dosage between 0.5 and 10 ng/ml, and the synthesis of DNA became saturated when the dosage was over 10 ng/ml. TGF-beta1 gave no effects on the proliferation of HSC under current experimental condition. Furthermore, PDGF was able to enhance the mRNA expression for type I and III procollagens and PDGF itself. The promoting effect for the expressions of type I and III procollagen mRNAs by PDGF was bi-phasic between 6 to 48 hours of the cultivation. For type I procollagen, mRNA expression began to increase 12 hours after PDGF stimulation, and the increase became prominent at 48 hours. For type III procollagen, an increase of mRNA expression was seen before the stimulation of PDGF, and the expression level was comparatively increased 48 hours later. The mRNA expression of PDGF was increased by 2-3 times 6 hours after PDGF stimulation, and back to the original level 24 hours later.
CONCLUSIONS
PDGF enabled to promote the proliferation of HSC and expression of collagens in HSC. The bi-phasic effect on the expression of collagens may be interrelated with the autocrine excretion of PDGF.
Publication
Journal: Current Medical Science
October/28/2018
Abstract
Low-temperature plasma (LTP) has shown great promise in wound healing, although the underlying mechanism remains poorly understood. In the present study, an argon atmospheric pressure plasma jet was employed to treat L929 murine fibroblasts cultured in vitro and skin wounds in BALB/c mice. The in vitro analysis revealed that treatment of fibroblasts with LTP for 15 s resulted in a significant increase in cell proliferation, secretion of epidermal growth factor (EGF) and transforming growth factor-βi (TGF-βi), production of intracellular reactive oxygen species (ROS), and the percentage of cells in S phase, protein expression of phosphorylated p65 (P-p65) and cyclinD1, but a noted decrease in the protein expression of inhibitor kappa B (IκB). The in vitro experiments demonstrated that 30-s LTP treatment enhanced the number of fibroblasts and the ability of collagen synthesis, while 50-s treatment led to the opposite outcomes. These results suggested that LTP treatment promotes the fibroblast proliferation in wound healing by inducing the generation of ROS, upregulating the expression of P-p65, downregulating the expression of IκB, and activating the NF-κB signaling pathway and consequently altering cell cycle progression (increased DNA synthesis in S phage).
Publication
Journal: Cancer Immunology, Immunotherapy
August/31/2005
Abstract
An ascitic lymphosarcoma (LS-A) of Swiss mice that regressed spontaneously on subcutaneous (s.c.) transplantation was investigated for the mechanism of its progressive growth and host mortality on intraperitoneal (i.p.) transplantation. In vitro studies indicated significant inhibition of LS-A proliferation seeded at higher cell density (>10(4)/ml). Culture supernatants of LS-A caused bi-modal growth effects, the early supernatants (24 h) caused stimulation and the late (72 h) supernatants inhibited LS-A proliferation. The 72-h supernatants also suppressed T and B cell response to mitogens in a dose-dependent manner. Pan anti-transforming growth factor-beta antibody abrogated the inhibitory effects of supernatants. The supernatants contained both latent as well as bio-active form of transforming growth factor-beta1 (TGF-beta1) as determined by ELISA. Mice bearing i.p. ascites tumor had elevated serum TGF-beta1, hemoglobulinemia, splenic lymphopenia, impaired response of the T cells to mitogen and reduced expression of transferrin receptor (CD71) on the bone marrow cells. However, mice which rejected s.c. transplants, did not show significant changes in these parameters. Our studies indicated profound influence of site of tumor growth on tumor progression and host immune system mediated by tumor-derived TGF-beta1. It is possible that human tumors which secrete TGF-beta1 may exhibit similar patho-physiological effects in the host depending on the anatomical site of the tumor.
Publication
Journal: Communications Biology
February/22/2019
Abstract
The cornea plays an important role in transmitting light and providing protection to the eye, but is susceptible to injury and infection. Standard treatments for corneal wounds include topical lubricants, antibiotics, bandage contact lens, and surgery. However, these measures are often ineffective. Here we show that MG53, a protein with an essential role in cell membrane repair, contributes to the corneal injury-repair process. Native MG53 is present in the corneal epithelia, tear film, and aqueous humor, suggesting its potential function in corneal homeostasis. Knockout of MG53 in mice causes impaired healing and regenerative capacity following injury. Exogenous recombinant human MG53 (rhMG53) protein protects the corneal epithelia against mechanical injury and enhances healing by promoting migration of corneal fibroblasts. Using in vivo alkaline-induced injury to the rat cornea, we show that rhMG53 promotes re-epithelialization and reduces post-injury fibrosis and vascularization. Finally, we show that rhMG53 modulates TGF-β-mediated fibrotic remodeling associated with corneal injury. Overall, our data support the bi-functional role of MG53 in facilitating corneal healing and maintaining corneal transparency by reducing fibrosis and vascularization associated with corneal injuries.
Publication
Journal: Zeitschrift für Naturforschung - Section C Journal of Biosciences
January/5/2012
Abstract
Fractionation of a 70% ethanolic extract from twigs of Lindera obtusiloba BLUME (Japanese spicebush, Tohaku) yielded five fractions of different polarity. The antifibrotic activity within the chloroform phase was best assessed by an in vitro bioassay using rat hepatic stellate cell (HSC) proliferation and their autocrine transforming growth factor beta (TGF-beta) expression as sensitive fibrosis-associated read out. Chromatography of the chloroform extract on Sephadex LH-20 or liquid-liquid extractions yielded a crystalline compound as an active principle, which was identified from NMR and ESI-MS analyses, its melting point, and its optical rotation as (7S,7'R,8R,8'R)-3,4:3',4'-bis(methylenedioxy)-7,9':7',9-diepoxy-lignane [(+)-episesamin]. X-Ray diffraction confirmed the structure and provided, for the first time, directly its absolute configuration. (+)-Episesamin blocked proliferation and the profibrotic autocrine TGF-beta expression HSC without significant cytotoxicity.
Publication
Journal: Cancer Letters
March/24/2019
Abstract
Epithelial to mesenchymal transition (EMT) is compulsory for metastatic dissemination and is stimulated by TGF-β. Although targeting EMT has significant therapeutic potential, very few pharmacological agents have been shown to exert anti-metastatic effects. BI-69A11, a competitive Akt inhibitor, displays anti-tumor activity toward melanoma and colon carcinoma. This study provides molecular and biochemical insights into the effects of BI-69A11 on EMT in colon carcinoma cells in vitro and in vivo. BI-69A11 inhibited metastasis-associated cellular migration, invasion and adhesion by inhibiting the Akt-β-catenin pathway. The underlying mechanism of BI-69A11-mediated inhibition of EMT included suppression of nuclear transport of β-catenin and diminished phosphorylation of β-catenin, which was accompanied by enhanced E-cadherin-β-catenin complex formation at the plasma membrane. Additionally, BI-69A11 caused increased accumulation of vinculin in the plasma membrane, which fortified focal adhesion junctions leading to inhibition of metastasis. BI-69A11 downregulated activation of the TGF-β-induced non-canonical Akt/NF-κB pathway and blocked TGF-β-induced enhanced expression of Snail causing restoration of E-cadherin. Overall, this study enhances our understanding of the molecular mechanism of BI-69A11-induced reversal of EMT in colorectal carcinoma cells in vitro, in vivo and in TGF-β-induced model systems.
Publication
Journal: Veterinary Parasitology
December/27/2016
Abstract
The muscle-stage larvae of the parasite Trichinella spiralis have the ability to survive within host muscle tissue by virtue of the formation a nurse cell-parasite complex, which is surrounded by collagen. The formation of the complex is initiated by excretory-secretory (ES) proteins produced by the parasite. To determine the mechanisms underlying collagen capsule formation, we investigated the expression levels of several types of collagen genes and TGF-βI signaling-related genes (Smad2 and Smad3) in muscle cells. Synthesis of type I, IV, and VI collagen, which are major constituents of the collagen capsule, significantly increased during T. spiralis infection. In addition, we found that expression of the protease-activated receptor 2 (PAR2) gene was significantly increased during this period. Expression levels of the collagen genes and TGF-βI, Smad2, and Smad3 were induced by ES proteins and a PAR2 agonist, whereas their enhanced expression levels were reduced by a PAR2 antagonist and serine protease inhibitors. To evaluate the involvement of PAR2 during T. spiralis infection in vivo, we infected wild-type and PAR2 knockout (KO) mice with T. spiralis. Expression levels of type I, IV, and VI collagen genes and TGF-βI signaling-related genes (Smad2 and Smad3) were also decreased in the PAR2 KO mice. Phosphorylation of Smad2/3, which was increased by T. spiralis infection, was significantly diminished in the PAR2 KO mice. In conclusion, ES proteins containing serine protease most likely activate collagen synthesis via PAR2 and TGF-βI signaling, and this event could influence collagen capsule formation.
Publication
Journal: Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences
November/4/2012
Abstract
OBJECTIVE
To isolate exosomes from rabbit aqueous humor and to investigate their immunosuppression function.
METHODS
Aqueous humor was collected from 40 New Zealand rabbits and exosomes were isolated by fractional separation and ultracentrifugation methods; the morphology was studied with electron microscopy. The immunosuppressive-related proteins of exosomes were detected with Western blotting; their inhibitory effect on ConA-induced proliferation of T lymphocyte was estimation with CCK-8 cells proliferation assay.
RESULTS
Eight milliliters of aqueous humor were collected from 40 New Zealand rabbits and 200 μg exosomes was yielded. Under electron microscope, the exosomes had typical structure of lipid bi-layer with a diameter of 50-100 nm. The results of Western blotting showed that these exosomes expressed Hsp70, CD9 and Alix but not Grp94, presenting a typical exosomes protein profile. Moreover, exosomes expressed high level of TGF-β and significantly inhibited the proliferation of T lymphocytes.
CONCLUSIONS
Immunosuppressive exosomes can be isolated from rabbit aqueous humor, which may be involved in immunotolerance of the eye.
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Publication
Journal: GLIA
August/3/2017
Abstract
The electrogenic sodium bicarbonate cotransporter NBCe1 (SLC4A4) expressed in astrocytes regulates intracellular and extracellular pH. Here, we introduce transforming growth factor beta (TGF-β) as a novel regulator of NBCe1 transcription and functional expression. Using hippocampal slices and primary hippocampal and cortical astrocyte cultures, we investigated regulation of NBCe1 and elucidated the underlying signaling pathways by RT-PCR, immunoblotting, immunofluorescence, intracellular H(+ ) recording using the H(+ ) -sensitive dye 2',7'-bis-(carboxyethyl)-5-(and-6)-carboxyfluorescein, mink lung epithelial cell (MLEC) assay, and chromatin immunoprecipitation. Activation of TGF-β signaling significantly upregulated transcript, protein, and surface expression of NBCe1. These effects were TGF-β receptor-mediated and suppressed following inhibition of JNK and Smad signaling. Moreover, 4-aminopyridine (4AP)-dependent NBCe1 regulation requires TGF-β. TGF-β increased the rate and amplitude of intracellular H+ changes upon challenging NBCe1 in wild-type astrocytes but not in cortical astrocytes from Slc4a4-deficient mice. A Smad4 binding sequence was identified in the NBCe1 promoter and Smad4 binding increased after activation of TGF-β signaling. The data show for the first time that NBCe1 is a direct target of TGF-β/Smad4 signaling. Through activation of the canonical pathway TGF-β acts directly on NBCe1 by binding of Smad4 to the NBCe1 promoter and regulating its transcription, followed by increased protein expression and transport activity.
Publication
Journal: Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
May/20/2019
Abstract

BACKGROUND
This study tested the hypothesis that Entresto could safely and effectively preserve heart and kidney function in rats with cardiorenal syndrome (CRS) induced by 5/6 nephrectomy and intra-peritoneal doxorubicin administration (accumulated dosage up to 7.5 mg/kg) together with daily high-protein-diet (HPD).

METHODS AND RESULTS
Adult male Sprague-Dawley rats (n = 24) were equally categorized into Group 1 (sham-operated control + HPD), Group 2 (CRS + HPD) and Group 3 [CRS + HPD + Entresto (100 mg/kg/day orally) since Day 14 after CRS induction] and euthanized by Day 63 after CRS induction. By Day 63, circulatory BUN and creatinine levels and ratios of urine protein to creatinine were significantly higher in Group 2 than those in Groups 1 and 3, and significantly higher in Group 3 than in Group 1, whereas left-ventricular ejection fraction and kidney weight showed an opposite pattern among all groups (all p < 0.001). Microscopically, fibrosis area and intensity of oxidative stress (i.e., DCFDA stain) in kidney/heart tissues exhibited a pattern identical to that of creatinine level among all groups (all p < 0.0001). Kidney injury score and protein expressions of autophagy (i.e., beclin-1/Atg-5/protein ratio of LC3-BII/LC3-BI), fibrosis (Smad3/TGF-ß), apoptosis (mitochondrial-Bax/capase2/3/9), oxidative-stress (NOX-4/oxidized protein/xanthine-oxidase/catalase), membranous p47phox phosphorylation and mitochondrial-damage biomarker (cytosolic-cytochrome-C) were higher in Group 2 than those in Groups 1 and 3, and significantly higher in Group 3 than in Group 1, while protein expressions of anti-apoptosis (Bcl-2/Bcl-XL) and mitochondrial integrity (mitochondrial-cytochrome-C) markers displayed an opposite pattern among all groups in kidney tissues (all p < 0.0001).

Oral administration of entresto was safe and could offer protection against CRS-induced heart and kidney damage.
Publication
Journal: Journal of Gastroenterology and Hepatology
May/14/2012
Abstract
OBJECTIVE
The identification of gastric carcinomas (GC) has traditionally been based on histomorphology. Recently, DNA microarrays have successfully been used to identify tumors through clustering of the expression profiles. Random forest clustering is widely used for tissue microarrays and other immunohistochemical data, because it handles highly-skewed tumor marker expressions well, and weighs the contribution of each marker according to its relatedness with other tumor markers. In the present study, we identified biologically- and clinically-meaningful groups of GC by hierarchical clustering analysis of immunohistochemical protein expression.
METHODS
We selected 28 proteins (p16, p27, p21, cyclin D1, cyclin A, cyclin B1, pRb, p53, c-met, c-erbB-2, vascular endothelial growth factor, transforming growth factor [TGF]-βI, TGF-βII, MutS homolog-2, bcl-2, bax, bak, bcl-x, adenomatous polyposis coli, clathrin, E-cadherin, β-catenin, mucin (MUC)1, MUC2, MUC5AC, MUC6, matrix metalloproteinase [MMP]-2, and MMP-9) to be investigated by immunohistochemistry in 482 GC. The analyses of the data were done using a random forest-clustering method.
RESULTS
Proteins related to cell cycle, growth factor, cell motility, cell adhesion, apoptosis, and matrix remodeling were highly expressed in GC. We identified protein expressions associated with poor survival in diffuse-type GC.
CONCLUSIONS
Based on the expression analysis of 28 proteins, we identified two groups of GC that could not be explained by any clinicopathological variables, and a subgroup of long-surviving diffuse-type GC patients with a distinct molecular profile. These results provide not only a new molecular basis for understanding the biological properties of GC, but also better prediction of survival than the classic pathological grouping.
Publication
Journal: Oncotarget
February/23/2017
Abstract
In this study, the bleomycin model of pulmonary fibrosis was utilized to investigate putative anti-fibrotic activity of Ac-SDKP in vivo. Male CD-1 mice received intra-tracheal bleomycin (BLEO, 1 mg/kg) instillation in the absence or presence of Ac-SDKP (a dose of 0.6 mg/kg delivered intra-peritoneally on the day of BLEO treatment, d0, followed by bi-weekly additional doses). To evaluate therapeutic effects in a subset of mice, Ac-SDKP was administered one week after BLEO instillation (d7). Animals were sacrificed at one, two, or three weeks later. Measurement of fluid and collagen content in the lung, Broncho Alveolar Lavage Fluid (BALF) analysis, lung histology, immunohistochemistry (IHC), and molecular analysis were performed. Compared to BLEO-treated mice, animals that received also Ac-SDKP (at both d0 and d7) had significantly decreased mortality, weight loss, inflammation (edema, and leukocyte lung infiltration), lung damage (histological evidence of lung injury), and fibrosis (collagen histological staining and soluble collagen content in the lung) at up to 21 days. Moreover, IHC and quantitative RT-PCR results demonstrated a significant decrease in BLEO-induced IL-17 and TGF-β expression in lung tissue. Importantly, α-SMA expression, the hallmark of myofibroblast differentiation, was also decreased. This is the first report showing not only a preventive protective role of Ac-SDKP but also its significant therapeutic effects in the bleomycin model of pulmonary fibrosis, thus supporting further preclinical and clinical studies.
Publication
Journal: Life Sciences
January/31/2019
Abstract
Arsenic exposure can cause fibrosis of organs including the liver, heart and lung. It was reported that TGF-β/Smad pathway played a crucial role in the process of fibrosis. However, the mechanism of arsenic-induced fibrosis through TGF-β/Smad signaling pathway has remained controversial.A systematic review and meta-analysis was performed to clarify the relationship between arsenic and TGF-β/Smad pathway, providing a theoretical basis of fibrosis process caused by arsenic.

METHODS
A meta-analysis was used to reveal a correlation between arsenic and fibrosis markers of TGF-β/Smad pathway, including 47 articles of both in vivo and in vitro studies. (Standardized Mean Difference) SMD was employed to compare and analyze the combined effects. When I2 > was 50%, random effect model was selected and subgroup analysis was used to explore the source of heterogeneity.

Arsenic exposure up-regulated the expression of TGF-β1, p-Smad2/3, α-SMA, Collagen1/3 and FN. The dose-response relationship showed that low dose (≤5 μmol/L) arsenic exposure up-regulated the expression of TGF-β1, whereas high doses had a tendency to down-regulate that of TGF-β1. Subgroup analysis showed that low or short-term arsenic exposure induced the expression of TGF-β1 and fibrosis markers.The results indicated that arsenic activates the TGF-β/Smad pathway and induced fibrosis. The mechanism is related to the up-regulation of NADPH oxidase and ROS accumulation. However, high-dose arsenic exposure may inhibit this pathway.
Publication
Journal: Journal of Lipid Research
June/4/2013
Abstract
Cellular cholesterol is known to be under homeostatic control in nonsteroidogenic cells, and this intrigued us to understand how such control works in steroidogenic cells that additionally use cholesterol for steroid hormone synthesis. We employed primary culture of rat ovarian granulosa cells to study how steroidogenic cells adapt to acquire sufficient cholesterol to meet the demand of active steroidogenesis under the stimulation of gonadotropin follicle-stimulating hormone (FSH) and cytokine transforming growth factor (TGF)β1. We found that TGFβ1 potentiated FSH to upregulate scavenger receptor class B member I (SR-BI) and LDL receptor (LDLR), both functional in uptaking cholesterol as hHDL(3) and hLDL supplementation enhanced progesterone production, and the effect of each lipoprotein was completely or partially blocked by SR-BI selective inhibitor BLT-1. Uptaken cholesterol could also be stored in lipid droplets. Importantly, LDLR and SR-BI responded to sterol with different sensitivity. Giving cells lipoproteins or 25-hydroxycholesterol downregulated Ldlr but not Scarb1; Scarb1 was ultimately downregulated by excessive sterol accumulation under 25-hydroxycholesterol and aminoglutethimide (inhibitor of steroidogenesis) cotreatment. Furthermore, transcription factors sterol regulatory element-binding protein (SREBP)-2 and liver receptor homolog (LRH)-1 crucially mediated Ldlr and Scarb1 differential response to sterol challenge. This study reveals that ovarian granulosa cells retain the cholesterol homeostatic control machinery like nonsteroidogenic cells, although during active steroidogenesis, they utilize SR-BI to evade such feedback control.
Publication
Journal: Archives of Environmental Contamination and Toxicology
April/22/1998
Abstract
Numerous studies suggest that tributyltin (TBT) is a potent immunotoxicant in nontarget organisms with lymphoid atrophy being a hallmark response. Two of the most common formulations of TBT are bis (tri-n-butyl)-tin oxide (TBTO) and tri-n-butyl-tin chloride (TBTCl). Most of studies investigating TBT-related immunotoxicity have used relatively high doses of both compounds, but little is known about the effects of very low doses. In addition, no studies have directly compared the effects of both formulations on immune function(s). We exposed female B6C3F1 mice to a single dose of TBTO or TBTCl at 0.3, 3.0, 30 mM/kg or corn oil as a carrier control. Forty-eight h later mice received a 4% solution of thioglycolate intraperitoneally to elicit peritoneal macrophages. Ninety-six h later macrophages were harvested and stimulated with a mixture of gamma-interferon (IFN-gamma) and lipopolysaccharide (LPS). Nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), transforming growth factor beta-1 (TGF-beta1), and phorbol ester-stimulated oxidative burst activity were then measured. Nitric oxide and TNF-alpha production were significantly elevated in the 0.3 and 3.0 mM TBTO/kg-treated groups but not in those treated by TBTCl. Background TNF-alpha production (without stimulation) was also elevated at these two doses but suppressed in TBTCl-treated animals. Oxidative burst activity was elevated at 0.3 mM TBTO/kg but not by TBTCl. TGF-beta1 production was not altered by either treatment, nor were body wts and organ-body wt ratios. To further evaluate the difference between the effects of TBTO and TBTCl on macrophage function, the in vitro toxicity of the two was determined using elicited peritoneal macrophages from untreated mice. Following a 24-h exposure to increasing concentrations of TBTO or TBTCl, functional viability was evaluated using the MTT assay. There were no differences between the two compounds in terms of treatment-related viability except that at the very highest concentrations (10(-6) M) TBTO was more toxic than TBTCl.
Publication
Journal: Pathobiology
June/12/2005
Abstract
OBJECTIVE
Tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta (TGF-beta) are cytokines that play key roles in the myelodysplastic syndrome (MDS). There have been several reports on the presence of genetic polymorphisms in the DNA sequence encoding the leader sequence of the TGF-beta1 protein, located in codon 10 in exon 1 and in the -308 promoter region of TNF-alpha. The objective of this study was to investigate the association between TNF-alpha and TGF-beta1 gene polymorphisms and the susceptibility to MDS and the progression of the disease among patients with MDS belonging to the refractory anemia (RA) subtype.
METHODS
The diagnosis of MDS (n = 50) was based on the FAB criteria. The TNF-alpha genotypes were analyzed by PCR-RFLP and the TGF-beta genotypes were analyzed using an amplification refractory mutation system.
CONCLUSIONS
Compared with healthy control subjects, patients with RA showed no significant deviations in genotype or allele frequencies of TNF-alpha. The TT homozygosity at codon 10 of TGF-beta1 was significantly higher among patients with bi- or pancytopenia (severe group) than in the patients with anemia only (mild group; odds ratio = 6.99, p = 0.003). These findings suggest that the TGF-beta1 gene polymorphism in codon 10 and the -308 TNF-alpha gene polymorphism do not predispose to the development of RA, but the TGF-beta1 gene polymorphism may affect disease progression.
Publication
Journal: Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics
June/27/2011
Abstract
OBJECTIVE
Transforming growth factor β1 (TGF-β1) plays a role in repair and dentinogenesis in dental pulp. The purpose of this study was to study how TGF-β1 affects 2 differentiation markers, Runt-related transcription factor 2 (Runx-2) and ALP, in dental pulp cells.
METHODS
Primary-cultured human dental pulp cells were treated with TGF-β1 with or without pretreatment and coincubation with 1,4-diamino-2,3-dicyano-1,4-bis(o-aminophenylmercapto)butadiene (U0126, a mitogen-induced extracellular kinase (MEK)/extracellular signal-regulated kinase (ERK) inhibitor), Noggin (a bone morphogenetic protein inhibitor), or 4-(5-benzol[1,3]dioxol-5-yl-4-pyrldin-2-yl-1H-imidazol-2-yl)-benzamide hydrate (SB431542, an activin receptor-like kinase (ALK) 5/Smad2/3 inhibitor). The differentiation status of pulp cells was evaluated by ALP staining and quantitative ALP activity assay. Changes in ALP and Runx-2 mRNA expression were determined by reverse-transcription polymerase chain reaction.
RESULTS
Cells under the treatment of TGF-β1 (5 and 10 ng/mL) showed a decrease in ALP activity and gene expression of ALP and Runx-2. Pretreatment by U0126 and Noggin was not effective to prevent the TGF-β1-induced decline of ALP activity. Interestingly, SB431542 prevented the TGF-β1-induced decline of ALP activity and ALP and Runx-2 gene expression.
CONCLUSIONS
TGF-β1 down-regulates Runx-2 and ALP in human dental pulp cells via ALK5/Smad2/3 signaling. These events may play important roles at specific stages of pulpal repair and dentinogenesis.
Publication
Journal: Liver International
February/10/2011
Abstract
BACKGROUND
Transforming growth factor (TGF)-β-1 is a very efficient inhibitor of hepatocyte proliferation in various in vivo and in vitro experimental systems. However, there are no data on whether it can influence the mitogenic response induced by primary hepatocyte mitogens.
OBJECTIVE
In this study, we compared the proliferative response in the liver between wild-type and transgenic mice, overexpressing active TGF-β-1 in their liver following the treatment by a primary hepatocyte mitogen TCPOBOP (1,4-bis[2-(3,5-dichloropyridyloxy)]benzene).
METHODS
The proliferative response was characterized by the immunohistochemical examination of pulse and cumulative bromodeoxyuridine labelling and by quantitative real-time polymerase chain reaction analysis of cell cycle-related genes.
RESULTS
Neither of the applied techniques revealed significant differences between the two groups of mice; furthermore, we observed the upregulation of TGF-β-1 expression following the mitogenic treatment.
CONCLUSIONS
TGF-β-1 does not inhibit the primary mitogen-induced proliferative response of the hepatocytes. This observation may provide an explanation for the divergent consequences of hepatic proliferations induced by partial hepatectomy or primary mitogenic treatment.
Publication
Journal: Nature Communications
December/3/2019
Abstract
Integrin αVβ8, which like αVβ6 functions to activate TGF-βs, is atypical. Its β8 subunit binds to a distinctive cytoskeleton adaptor and does not exhibit large changes in conformation upon binding to ligand. Here, crystal structures, hydrogen-deuterium exchange dynamics, and affinity measurements on mutants are used to compare αVβ8 and αVβ6. Lack of a binding site for one of three βI domain divalent cations and a unique β6-α7 loop conformation in β8 facilitate movements of the α1 and α1' helices at the ligand binding pocket toward the high affinity state, without coupling to β6-α7 loop reshaping and α7-helix pistoning that drive large changes in βI domain-hybrid domain orientation seen in other integrins. Reciprocal swaps between β6 and β8 βI domains increase affinity of αVβ6 and decrease affinity of αVβ8 and define features that regulate affinity of the βI domain and its coupling to the hybrid domain.
Publication
Journal: Journal of Ethnopharmacology
July/22/2015
Abstract
BACKGROUND
Tulbaghia violacea has been used traditionally for the treatment of several ailments, including hypertension. The herb has been shown to have antihypertensive properties which have been attributed to its angiotensin-converting enzymeinhibitory (ACEI) activity. It could, therefore, prove beneficial in ameliorating renal pathology associated with hypertension. To evaluate the effects of long-term administration of Tulbaghia violacea on renal function and morphology in the Dahl salt-sensitive (DSS) rat model.
METHODS
Male DSS rats were treated intra-peritoneally (i.p.) as follows: methanolic extract of Tulbaghia violacea: (TVL) (50 mg/kg/b.w.), captopril: (CAP) (25 mg/kg/b.w.), or distilled water, control: (CON) (3 ml/kg/b.w.). Blood pressure (BP) was measured bi-weekly, whilst 24-h urine volumes and electrolyte concentrations were assessed weekly. Animals were sacrificed on day 49 by halothane overdose. Blood was removed for determination of plasma and serum electrolytes. Left kidney tissues were harvested for the determination of nuclear factor-kappaβ (NF-kβ) and transforming growth factor-β (TGF-β) gene expressions.
RESULTS
TVL significantly reduced mean arterial pressure (MAP) and diastolic blood pressure (DBP). TVL showed reduced blood urea nitrogen, serum creatinine, total protein in urine as well as increased serum total protein. TVL decreased thiobarbituric acid reactive substances (TBARS) and increased glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity and nitric oxide significantly. NF-kβ and TGF-β) gene expressions were significantly reduced in TVL and CAP treated rats. Moreover, renal morphology improved significantly in TVL and CAP treated animals.
CONCLUSIONS
TVL and CAP demonstrated marked improvement in renal function and morphology.
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