Differential Role of Aldosterone and Transforming Growth Factor Beta-1 in Cardiac Remodeling

Angiotensin II, a major culprit in cardiovascular disease, activates mediators that are also involved in pathological cardiac remodeling. In this context, we aimed at investigating the effects of two of them: aldosterone (Ald) and transforming growth factor beta-1 (TGF-β1) in an in vivo model. Six-week-old male wild-type (WT) and TGF-β1-overexpressing transgenic (TGF-β1-TG) mice were infused with subhypertensive doses of Ald for 2 weeks and/or treated orally with eplerenone from postnatal day 21. Thehearts' ventricles were examined by morphometry, immunoblotting to assess the intracellular signaling pathways and RT qPCR to determine hypertrophy and fibrosis marker genes. The TGF-β1-TG mice spontaneously developed cardiac hypertrophy and interstitial fibrosis and exhibited a higher baseline phosphorylation of p44/42 and p38 kinases, fibronectin and ANP mRNA expression. Ald induced a comparable increase in the ventricular-heart-weight-to-body-weight ratio and cardiomyocyte diameter in both strains, but a less pronounced increase in interstitial fibrosis in the transgenic compared to the WT mice (23.6% vs. 80.9%, p < 0.005). Ald increased the phosphorylation of p44/42 and p38 in the WT but not the TGF-β1-TG mice. While the eplerenone-enriched chow partially prevented Ald-induced cardiac hypertrophy in both genotypes and interstitial fibrosis in the WT controls, it completely protected against additional fibrosis in transgenic mice. Ald appears to induce cardiac hypertrophy independently of TGF-β1, while in the case of fibrosis, the downstream signaling pathways of these two factors probably converge.

Intra- and Intertumoral Microglia/Macrophage Infiltration and Their Associated Molecular Signature Is Highly Variable in Canine Oligodendroglioma: A Preliminary Evaluation

The goal of this study was to define the glioma-associated microglia/macrophage (GAM) response and associated molecular landscape in canine oligodendrogliomas. Here, we quantified the intratumoral GAM density of low- and high-grade oligodendrogliomas compared to that of a normal brain, as well as the intratumoral concentration of several known GAM-derived pro-tumorigenic molecules in high-grade oligodendrogliomas compared to that in a normal brain. Our analysis demonstrated marked intra- and intertumoral heterogeneity of GAM infiltration. Correspondingly, we observed significant variability in the intratumoral concentrations of several GAM-associated molecules, unlike what we previously observed in high-grade astrocytomas. However, high-grade oligodendroglioma tumor homogenates (n = 6) exhibited an increase in the pro-tumorigenic molecules hepatocyte growth factor receptor (HGFR) and vascular endothelial growth factor (VEGF), as we observed in high-grade astrocytomas. Moreover, neoplastic oligodendrocytes displayed robust expression of GAL-3, a chimeric galectin implicated in driving immunosuppression in human glioblastoma. While this work identifies shared putative therapeutic targets across canine glioma subtypes (HGFR, GAL-3), it highlights several key differences in the immune landscape. Therefore, a continued effort to develop a comprehensive understanding of the immune microenvironment within each subtype is necessary to inform therapeutic strategies going forward.

Early-immediate gene Egr1 is associated with TGFβ1 regulation of epigenetic reader Bromodomain-containing protein 4 via the canonical Smad3 signaling in hepatic stellate cells in vitro and in vivo

Upon chronic damage to the liver, multiple cytokines stimulate hepatic stellate cells (HSCs), causing the alterations of gene expression profiles and thus leading to HSC activation, a key step in liver fibrogenesis. Activated HSCs are the dominant contributors to liver fibrosis. Bromodomain containing protein 4 (BrD4), an important epigenetic reader, was demonstrated to concentrate on hundreds of enhancers associated with genes involved in multiple profibrotic pathways, thereby directing HSC activation and the fibrotic responses. The present studies were designed to examine the effect of transforming growth factor beta-1 (TGFβ1), the most potent pro-fibrotic cytokine, on BrD4 expression in HSCs and, if so, elucidated the underlying mechanisms in vitro and in vivo. The experiments employed the heterogeneous TGFβ1 knockout (TGFβ1^+/- ) mice, gene knockdown in vivo, and a model of thioacetamide (TAA)-induced liver injury. The results revealed that TGFβ1 enhanced BrD4 expression in HSCs, which was mediated, at least, by Smad3 signaling and early-immediate gene Egr1 (early growth response-1). TGFβ1-induced Smad3 signaling increased Egr1 expression and promoted Egr1 binding to BrD4 promoter at a site around -111 bp, promoting BrD4 expression. Egr1 knockdown reduced BrD4 expression in HSCs in a mouse model of TAA-induced liver injury and lessened liver fibrosis. Double fluorescence staining demonstrated a strong increase in BrD4 expression in activated HSCs in fibrotic areas of the human livers, paralleling the upregulation of p-Smad3 and Egr1. This research suggested novel molecular events underlying the roles of the master pro-fibrotic cytokine TGFβ1 in HSC activation and liver fibrogenesis.

miR-29b Regulates TGF-β1-Induced Epithelial-Mesenchymal Transition by Inhibiting Heat Shock Protein 47 Expression in Airway Epithelial Cells

Tissue remodeling contributes to ongoing inflammation and refractoriness of chronic rhinosinusitis (CRS). During this process, epithelial-mesenchymal transition (EMT) plays an important role in dysregulated remodeling and both microRNA (miR)-29b and heat shock protein 47 (HSP47) may be engaged in the pathophysiology of CRS. This study aimed to determine the role of miR-29b and HSP47 in modulating transforming growth factor (TGF)-β1-induced EMT and migration in airway epithelial cells. Expression levels of miR-29b, HSP47, E-cadherin, α-smooth muscle actin (α-SMA), vimentin and fibronectin were assessed through real-time PCR, Western blotting, and immunofluorescence staining. Small interfering RNA (siRNA) targeted against miR-29b and HSP47 were transfected to regulate the expression of EMT-related markers. Cell migration was evaluated with wound scratch and transwell migration assay. miR-29b mimic significantly inhibited the expression of HSP47 and TGF-β1-induced EMT-related markers in A549 cells. However, the miR-29b inhibitor more greatly induced the expression of them. HSP47 knockout suppressed TGF-β1-induced EMT marker levels. Functional studies indicated that TGF-β1-induced EMT was regulated by miR-29b and HSP47 in A549 cells. These findings were further verified in primary nasal epithelial cells. miR-29b modulated TGF-β1-induced EMT-related markers and migration via HSP47 expression modulation in A549 and primary nasal epithelial cells. These results suggested the importance of miR-29b and HSP47 in pathologic tissue remodeling progression in CRS.

Decitabine Inhibits Bone Resorption in Periodontitis by Upregulating Anti-Inflammatory Cytokines and Suppressing Osteoclastogenesis

DNA methylation controls several inflammatory genes affecting bone homeostasis. Hitherto, inhibition of DNA methylation in vivo in the context of periodontitis and osteoclastogenesis has not been attempted. Ligature-induced periodontitis in C57BL/6J mice was induced by placing ligature for five days with Decitabine (5-aza-2′-deoxycytidine) (1 mg/kg/day) or vehicle treatment. We evaluated bone resorption, osteoclast differentiation by tartrate-resistant acid phosphatase (TRAP) and mRNA expression of anti-inflammatory molecules using cluster differentiation 14 positive (CD14⁺) monocytes from human peripheral blood. Our data showed that decitabine inhibited bone loss and osteoclast differentiation experimental periodontitis, and suppressed osteoclast CD14⁺ human monocytes; and conversely, that it increased bone mineralization in osteoblastic cell line MC3T3-E1 in a concentration-dependent manner. In addition to increasing IL10 (interleukin-10), TGFB (transforming growth factor beta-1) in CD14⁺ monocytes, decitabine upregulated KLF2 (Krüppel-like factor-2) expression. Overexpression of KLF2 protein enhanced the transcription of IL10 and TGFB. On the contrary, site-directed mutagenesis of KLF2 binding site in IL10 and TFGB abrogated luciferase activity in HEK293T cells. Decitabine reduces bone loss in a mouse model of periodontitis by inhibiting osteoclastogenesis through the upregulation of anti-inflammatory cytokines via KLF2 dependent mechanisms. DNA methyltransferase inhibitors merit further investigation as a possible novel therapy for periodontitis.

TGF-β1 Activates Nasal Fibroblasts through the Induction of Endoplasmic Reticulum Stress

(1) Background: Tissue remodeling and extracellular matrix (ECM) accumulation contribute to the development of chronic inflammatory diseases of the upper airway. Endoplasmic reticulum (ER) stress is considered to be the key signal for triggering tissue remodeling in pathological conditions. The present study aimed to investigate the role of ER-stress in TGF-β1-stimulated nasal fibroblasts and inferior turbinate organ cultures; (2) Methods: Fibroblasts and organ cultures were pretreated with 4-phenylbutyric acid (PBA) and stimulated with TGF-β1 or thapsigargin (TG). Expression of ER-stress markers, myofibroblast marker, and ECM components was measured by Western blotting and real-time PCR. Reactive oxygen species (ROS) were quantified using 2',7'-dichlorofluorescein diacetate. Cell migration was evaluated using Transwell assays. Contractile activity was measured by collagen contraction assay; (3) Results: 4-PBA inhibited TGF-β1 or TG-induced ER-stress marker expression, phenotypic changes, and ECM. Pre-treatment with ROS scavengers inhibited the expression of TGF-β1-induced ER-stress markers. Migration and collagen contraction of TGF-β1 or TG-stimulated fibroblasts were ameliorated by 4-PBA treatment. These findings were confirmed in ex vivo organ cultures; (4) Conclusions: 4-PBA downregulates TGF-β1-induced ER-stress marker expression, migration, and collagen contraction via ROS in fibroblasts and organ cultures. These results suggest that ER-stress may play an important role in progression of chronic upper airway inflammatory diseases by aiding pathological tissue remodeling.

Pirfenidone anti-fibrotic effects are partially mediated by the inhibition of MUC1 bioactivation

Pirfenidone is a pleiotropic molecule approved to treat idiopathic pulmonary fibrosis (IPF). Pirfenidone has demonstrated to downregulate transforming growth factor-β1 (TGF-β1) cellular effects. However, its anti-fibrotic mechanism remains unclear. Here, we aim to analyze the effects of pirfenidone on the TGF-β1 canonical and non-canonical pathways, as well as, on the most characteristic IPF cellular processes. Results observed in this work showed that TGF-β1-induced canonical SMAD3 and non-canonical ERK1/2 phosphorylations were not inhibited by pirfenidone in alveolar A549 and lung fibroblasts MRC5 cells. In contrast, pirfenidone inhibited TGF-β1-induced MUC1-CT Thr⁴¹ (1224) and Tyr⁴⁶ (1229) phosphorylations, thus reducing the β-catenin activation. Additionally, immunoprecipitation and immunofluorescence studies in ATII cells and lung fibroblasts showed that pirfenidone inhibited the formation and nuclear translocation of the transcriptional fibrotic TGF-β1-induced phospho-SMAD3/MUC1-CT/active-β-catenin complex, and consequently the SMAD-binding element activation (SBE). This study provided also evidence of the inhibitory effect of pirfenidone on the TGF-β1-induced ATII to mesenchymal and fibroblast to myofibroblast transitions, fibroblast proliferation and ATII and fibroblast senescence. Therefore, it indicates that pirfenidone’s inhibitory effect on TGF-β1-induced fibrotic cellular processes is mediated by the inhibition of MUC1-CT phosphorylation, β-catenin activation, nuclear complex formation of phospho-SMAD3/MUC1-CT/active β-catenin and SBE activation, which may be of value to further develop anti-fibrotic IPF therapies.

Structural consequences of transforming growth factor beta-1 activation from near-therapeutic X-ray doses

Dissociation of transforming growth factor beta-1 (TGFβ-1) from the inhibitory protein latency-associated peptide (LAP) can occur from low doses of X-ray irradiation of the LAP-TGFβ-1 complex, resulting in the activation of TGFβ-1, and can have health-related consequences. Using the tools and knowledge developed in the study of radiation damage in the crystallographic setting, small-angle X-ray scattering (SAXS) and complementary techniques suggest an activation process that is initiated but not driven by the initial X-ray exposure. LAP is revealed to be extended when not bound to TGFβ-1 and has a different structural conformation compared to the bound state. These studies pave the way for the structural understanding of systems impacted at therapeutic X-ray doses and show the potential impact of radiation damage studies beyond their original intent.

Anti-fibrotic effect of rosmarinic acid on inhibition of pterygium epithelial cells

AIM

To investigate the anti-fibrosis effect of rosmarinic acid (RA) in pterygium epithelial cells (PECs) to determine if RA is a potent agent for treating pterygium.

METHODS

The PECs (1×10⁴ cells/mL) were treated with 100 µmol/L of RA for 1, 3 and 6h. After RA treatment, the cell viability was determined by staining with acridine orange/DAPI and analysis via a NucleoCounter NC-3000. The protein expression levels of type I collagen, transforming growth factor beta-1 (TGF-β1), TGF-β type II receptor (TGF-βRII), p-Smad1/5, p-Smad2, p-Smad3, and Smad4 of the cell lysates were measured by Western blot analysis.

RESULTS

The cell viability of PECs was significantly decreased after RA treatment (P<0.01). As the result, RA reduced the protein expression of type I collagen and TGF-β1 of PECs. Additionally, RA also inhibited TGF-β1/Smad signaling by decreasing the protein expressions of TGF-βRII, p-Smad1/5, p-Smad2, p-Smad3, and Smad4.

CONCLUSION

This study demonstrate that RA could inhibit fibrosis of PECs by down-regulating type I collagen expression and TGF-β1/Smad signaling. Therefore, RA is a potent therapeutic agent for the treatment of pterygium.

MMP-14 and TGFβ-1 methylation in pituitary adenomas

Pituitary adenoma (PA) is one of the most common abnormalities in the sellar region. Despite the fact that PA is a benign monoclonal neoplasm, it can cause serious complications, including ophthalmological, neurological and endocrinological abnormalities. Currently, the causes that increase the progression of tumors are unknown. Epigenetic silencing of the matrix metalloproteinase-14 (MMP-14) and transforming growth factor beta-1 (TGFβ-1) genes may be associated with the development of PA, since these genes are important in the processes of tumor metastasis and angiogenesis. The purpose of the present study was to determine if the methylation status of the MMP-14 and TGFβ-1 promoters is associated with PA development. In the present study, 120 tissue samples of PA were used. The methylation status of the MMP-14 and TGFβ-1 promoters was investigated by methylation specific-polymerase chain reaction. Statistical analysis was conducted to investigate the associations between the methylation status, age and gender of PA patients, PA tumoral activity, recurrence and invasiveness. The MMP-14 gene was methylated in 30.00% (17/56 functioning and 19/64 non-functioning) of patients with PA, while the TGFβ-1 gene was methylated in 13.33% (9/56 functioning and 7/64 non-functioning) of patients with PA. It was also observed that promoter methylation of MMP-14 correlated with the male gender (58.8 vs. 35.7%, P=0.022), while unmethylated (non-silenced) MMP-14 correlated with the female gender (64.3 vs. 41.7%, P=0.027). Associations between the promoter methylation status of the MMP-14 and TGFβ-1 genes and PA functioning or recurrence were not identified. The present study reveals that silencing of the MMP-14 gene correlates with patients' gender. However, MMP-14 and TGFβ-1 promoter methylation cannot be considered as a prognostic marker in PAs.

Modified Adenovirus Reduces De Novo Peritoneal Adhesions in Rats and Limits Off-Target Transfection. Role of EZH2 in Adhesion Formation

AIM OF THE STUDY

Adenovector encoding tissue plasminogen activator (tPA) was shown to reduce experimental peritoneal adhesion. We investigated the targeting potential of our modified adenovector, its ability to reduce adhesions and the epigenetic role of histone methyltransferase EZH2 in adhesion formation.

MATERIALS AND METHODS

Control lacZ, nonmodified tPA or modified tPA vectors were instilled in the peritoneal cavity after injury in de novo adhesions or after lysis of adhesions in recurrent adhesions. Adhesion severity was scored and adhesions and liver tissues were examined for adenovirus E4 gene and tPA mRNA expression. Levels of tPA, plasminogen activator inhibitor-1 (PAI-1), transforming growth factor-β1 (TGF-β1), and EZH2 expression were measured.

RESULTS

E4 transcripts were detected in adhesions of nonmodified and modified and in livers of nonmodified but not in livers of modified de novo adhesions. Both nonmodified (p = 0.021) and modified vectors (p = 0.036) reduced the severity of de novo adhesions compared to lacZ vector. Levels of tPA in nonmodified (p = 0.021) and modified adhesions (p = 0.001) were elevated while PAI-1 (p = 0.013 and p = 0.001, respectively) and TGF-β1 levels (p = 0.002 and p = 0.016, respectively) were reduced compared with lacZ group. All vectors were not expressed in recurrent adhesions and severity score were not different among groups. EZH2 levels were elevated in de novo nontreated (p = 0.001) and was further increased in recurrent (p = 0.001) nontreated adhesions compared with noninjured peritoneum.

CONCLUSION

Modified adenovirus successfully targeted de novo adhesions but not liver tissues and reduced the severity of de novo adhesions. EZH2 is involved in the development and progression of peritoneal adhesions.

Salvianolic acid B inhibits hepatic stellate cell activation through transforming growth factor beta-1 signal transduction pathway in vivo and in vitro

Salvianolic acid B (Sal B) is a major water soluble component extracted from Radix Salviae miltiorrhizae, a traditional Chinese herb widely used for treating cardiovascular and hepatic diseases. Sal B has been reported to inhibit transforming growth factor (TGF)-β1-stimulated hepatic stellate cells (HSCs) activation and collagen type I expression. In this study, we further investigated the mechanisms of Sal B on liver fibrosis relating to TGF-β/Smads signalling pathway, especially to TGF-β1 receptors. Liver fibrosis model was induced by intraperitoneal injection of dimethylnitrosamine (DMN) for four weeks. Rats were randomly divided into three groups: normal, model, and Sal B groups. Rats in Sal B group were treated by oral administration of Sal B for four weeks from the first day of DMN exposure. Hydroxyproline (Hyp) content in liver tissue was assayed using Jamall's method and collagen deposition was visualized using Sirius red staining. HSCs were isolated from normal rats, and were cultured primarily in uncoated plastics. At day 4 after isolation, cells were stimulated with 2.5 ng/mL TGF-β1, and treated with 1 and 10 µmol/L Sal B and 10 µmol/L SB-431542 (TβR-I inhibitor) for 24 h, respectively. Cell proliferation was examined with 5-ethynyl-2'-deoxyuridine assay. The expressions of alpha smooth muscle actin (α-SMA) and Smad3 were assayed by immunofluorescent stain and Western blotting. The expression of TβR-I was analysed by Western blotting and real-time polymerase chain reaction. The activity of TβR-I kinase was measured by ADP-Glo kinase assay. The results showed that Sal B could inhibit collagen deposition and reduce Hyp content significantly, and decrease expressions of TGF-β1 and TβR-I in fibrotic liver in vivo. Also, Sal B decreased the expressions of α-SMA and TβR-I, inhibited Smad3 nuclear translocation and down-regulated TβR-I kinase activity in vitro. These findings suggested that Sal B could prevent HSCs activation through TGF-β signalling pathway, i.e. inhibiting TGF-β1 expression, activity of TβR-I kinase and Smads phosphorylation.

Computer-aided identification of novel protein targets of bisphenol A

The xenoestrogen bisphenol A (2,2-bis-(p-hydroxyphenyl)-2-propane, BPA) is a known endocrine-disrupting chemical used in the fabrication of plastics, resins and flame retardants, that can be found throughout the environment and in numerous every day products. Human exposure to this chemical is extensive and generally occurs via oral route because it leaches from the food and beverage containers that contain it. Although most of the effects related to BPA exposure have been linked to the activation of the estrogen receptor (ER), the mechanisms of the interaction of BPA with protein targets different from ER are still unknown. Therefore, the objective of this work was to use a bioinformatics approach to identify possible new targets for BPA. Docking studies were performed between the optimized structure of BPA and 271 proteins related to different biochemical processes, as selected by text-mining. Refinement docking experiments and conformational analyses were carried out using LigandScout 3.0 for the proteins selected through the affinity ranking (lower than -8.0kcal/mol). Several proteins including ERR gamma (-9.9kcal/mol), and dual specificity protein kinases CLK-4 (-9.5kcal/mol), CLK-1 (-9.1kcal/mol) and CLK-2 (-9.0kcal/mol) presented great in silico binding affinities for BPA. The interactions between those proteins and BPA were mostly hydrophobic with the presence of some hydrogen bonds formed by leucine and asparagine residues. Therefore, this study suggests that this endocrine disruptor may have other targets different from the ER.

Expression of Clu and Tgfb1 during murine tooth development: effects of in-vivo transfection with anti-miR-214

Expression of clusterin (Clu) in the murine first molar tooth germ was markedly increased at postnatal developmental stages. The time-course of expression of this gene paralleled those of other genes encoding proteins involved during the secretory phase of odontogenesis, as described previously. Immunohistochemical studies of clusterin in murine molar tooth germs suggested this protein to be located in outer enamel epithelium, regressing enamel organ, secretory ameloblasts, and the dental epithelium connecting the tooth to the oral epithelium at an early eruptive stage. Immunolabelling of transforming growth factor beta-1 (TGF-β1) revealed it to be located close to clusterin. The levels of expression of Clu and Tgfb1 were markedly decreased following in-vivo transfection with anti-miR-214. In contrast, the expression of several genes associated with regulation of growth and development were increased by this treatment. We suggest that clusterin has functions during secretory odontogenesis and the early eruptive phase. Bioinformatic analysis after treatment with anti-miR-214 suggested that, whilst cellular activities associated with tooth mineralization and eruption were inhibited, activities associated with an alternative developmental activity (i.e. biosynthesis of contractile proteins) appeared to be stimulated. These changes probably occur through regulation mediated by a common cluster of transcription factors and support suggestions that microRNAs (miRNAs) are highly significant as regulators of differentiation during odontogenesis.

Serum TGF-β, Serum MMP-1, and HOMA-IR as non-invasive predictors of fibrosis in Egyptian patients with NAFLD

BACKGROUND/AIM

Non-alcoholic fatty liver disease (NAFLD) is an increasingly prevalent cause of chronic liver disease worldwide. A number of these patients progress to nonalcoholic steatohepatitis (NASH) which carries significant morbidity and mortality. The aim of this study is to evaluate the diagnostic value of serum levels of transforming growth factor beta-1 (TGF-β1) matrix metalloproteinase-1 (MMP-1), and insulin resistance as predictors of fibrosis in Egyptian NAFLD patients.

PATIENTS AND METHODS

Fifty patients with NAFLD and different stages of fibrosis were studied. Serum levels of TGF-β1, MMP-1, and fasting serum insulin were measured; calculation of the homeostasis model assessment for insulin resistance (HOMA-IR) was done.

RESULTS

TGF-β1 gives a sensitivity of 100% and specificity of 94.4% for stage 1 fibrosis, 100% and 93.9%, respectively, for stage 2 fibrosis, and 97.7% and 100%, respectively, for stage 3 fibrosis. MMP-1 showed sensitivity and specificity of 88% and 81.8%, respectively, for stage 2 fibrosis, 90.9% and 55.56%, respectively, for stage 3 fibrosis, but it is of no diagnostic value in stage 1 fibrosis.

CONCLUSION

Serum TGF-β1, MMP-1, and insulin resistance (HOMA-IR) proved to be potentially useful noninvasive markers in predicting fibrosis in NASH patients.