Chronic Exposure to TDI Induces Cell Migration and Invasion via TGF-β1 Signal Transduction

Toluene diisocyanate (TDI) is commonly used in manufacturing, and it is highly reactive and causes respiratory damage. This study aims to identify the mechanism of tumorigenesis in bronchial epithelial cells induced by chronic TDI exposure. In addition, transcriptome analysis results confirmed that TDI increases transforming growth factor-beta 1 (TGF-β1) expression and regulates genes associated with cancerous characteristics in bronchial cells. Our chronically TDI-exposed model exhibited elongated spindle-like morphology, a mesenchymal characteristic. Epithelial-mesenchymal transition (EMT) was evaluated following chronic TDI exposure, and EMT biomarkers increased concentration-dependently. Furthermore, our results indicated diminished cell adhesion molecules and intensified cell migration and invasion. In order to investigate the cellular regulatory mechanisms resulting from chronic TDI exposure, we focused on TGF-β1, a key factor regulated by TDI exposure. As predicted, TGF-β1 was significantly up-regulated and secreted in chronically TDI-exposed cells. In addition, SMAD2/3 was also activated considerably as it is the direct target of TGF-β1 and TGF-β1 receptors. Inhibiting TGF-β1 signaling through blocking of the TGF-β receptor attenuated EMT and cell migration in chronically TDI-exposed cells. Our results corroborate that chronic TDI exposure upregulates TGF-β1 secretion, activates TGF-β1 signal transduction, and leads to EMT and other cancer properties.

The Prognostic Value of Lung Injury and Fibrosis Markers, KL-6, TGF-β1, FGF-2 in COVID-19 Patients

Background:

Biomarkers of lung injury and interstitial fibrosis give insight about the extent of involvement and prognosis in well-known interstitial lung diseases (ILD). Serum Krebs von den Lungen-6 (KL-6) reflects direct alveolar injury and, transforming growth factor-beta1 (TGF-β1) and fibroblast growth factor-2 (FGF-2) are principal mediators of fibrosis in ILD and in almost all fibrotic diseases. In this sense, we aimed to assess associations of these biomarkers with traditional inflammatory markers and clinical course of COVID-19.

Methods:

Patients with COVID-19 who had confirmed diagnosis with SARS-CoV-2 nucleic acid RT-PCR were enrolled and followed up prospectively with a standardized approach one month after diagnosis. Patients were divided into severe and non-severe groups according to National Institutes of Health criteria. Outcome was assessed for the requirement of intensive care unit (ICU) admission, long term respiratory support and death. Blood samples were collected at enrollment and serum levels of KL-6, TGF-β1, FGF-2 were determined by ELISA. Association between these markers with other prognostic markers and prognosis were analyzed.

Results:

Overall 31 severe and 28 non-severe COVID-19 patients were enrolled and were compared with healthy control subjects (n = 30). Serum KL-6 levels in COVID-19 patients were significantly higher (median [IQR]; 11.54 [4.86] vs 8.54 [3.98] ng/mL, P = .001] and FGF-2 levels were lower (median [IQR]; 76.84 [98.2] vs 101.62 [210.6] pg/mL) compared to healthy control group. A significant correlation was found between KL-6 values and CRP, fibrinogen, d-dimer and lymphocyte counts. However, we did not find an association between these markers and subsequent severity of COVID-19, mortality and long-term prognosis.

Conclusions:

Serum KL-6 levels were significantly elevated at the diagnosis of COVID-19 and correlated well with the other traditional prognostic inflammatory markers. Serum levels of principal fibrosis mediators, TGF-β1, FGF-2, were not elevated at diagnosis of COVID-19, therefore did not help to anticipate long term prognosis.

Dynamics of Mycobacterium tuberculosis-Specific and Nonspecific Immune Responses in Women with Tuberculosis Infection during Pregnancy

The immune control of tuberculosis (TB) infection could be influenced by pregnancy. To elucidate this, we longitudinally characterized Mycobacterium tuberculosis (Mtb)-specific and nonspecific immune responses in women during pregnancy and postpartum. HIV-uninfected women without past or current active TB, and with blood samples available from the 1st/2nd trimester, 3rd trimester, and 9 months postpartum, were identified at Ethiopian antenatal care clinics. Twenty-two TB+ women and 10 TB- women, defined according to Mtb-stimulated interferon-γ levels (≥0.35 and <0.20 IU/mL, respectively, in the Quantiferon-TB Gold-Plus assay), were included in the study. Longitudinal dynamics of six cytokines (IL-1ra, IL-2, IP-10, MCP-2, MCP-3, and TGF-β1) were analyzed in supernatants from Mtb-stimulated and unstimulated whole blood. In TB+ women, Mtb-specific expression of IL-2 and IP-10 was higher at 3rd compared to 1st/2nd trimester (median 139 pg/mL versus 62 pg/mL, P = 0.006; 4,999 pg/mL versus 2,310 pg/mL, P = 0.031, respectively), whereas level of Mtb-triggered TGF-β1 was lower at 3rd compared to 1st/2nd trimester (-6.8 ng/mL versus 2.3 ng/mL, P = 0.020). Unstimulated IL-2, IP-10, and MCP-2 levels were increased postpartum, compared with those noted during pregnancy, in TB+ women. Additionally, postpartum levels of proinflammatory cytokines in unstimulated blood were higher in TB+ women, than in TB- women. None of the women developed active TB during follow-up. Taken together, dynamic changes of Mtb-specific cytokine expression revealed during the 3rd trimester in TB+ women indicate increased Mtb-antigen stimulation at later stages of pregnancy. This could reflect elevated bacterial activity, albeit without transition to active TB, during pregnancy. IMPORTANCE Tuberculosis (TB) is globally one of the most common causes of death, and a quarter of the world's population is estimated to have TB infection. The risk of active TB is increased in connection to pregnancy, a phenomenon that could be due to physiological immune changes. Here, we studied the effect of pregnancy on immune responses triggered in HIV-uninfected women with TB infection, by analyzing blood samples obtained longitudinally during pregnancy and after childbirth. We found that the dynamics of Mtb-specific and nonspecific immune responses changed during pregnancy, especially in later stages of pregnancy, although none of the women followed in this study developed active TB. This suggests that incipient TB, with elevated bacterial activity, occurs during pregnancy, but progression of infection appears to be counteracted by Mtb-specific immune responses. Thus, this study sheds light on immune control of TB during pregnancy, which could be of importance for future intervention strategies.

TGF-β1 Receptor Inhibitor SB525334 Attenuates the Epithelial to Mesenchymal Transition of Peritoneal Mesothelial Cells via the TGF-β1 Signaling Pathway

We investigated the effect of SB525334 (TGF-β receptor type 1 (TβRI) inhibitor) on the epithelial to mesenchymal transition (EMT) signaling pathway in human peritoneal mesothelial cells (HPMCs) and a peritoneal fibrosis mouse model. In vitro experiments were performed using HPMCs. HPMCs were treated with TGF-β1 and/or SB525334. In vivo experiments were conducted with male C57/BL6 mice. The 0.1% chlorhexidine gluconate (CG) was intraperitoneally injected with or without SB52534 administration by oral gavage. Mice were euthanized after 28 days. EMT using TGF-β1-treated HPMCs included morphological changes, cell migration and invasion, EMT markers and collagen synthesis. These pathological changes were reversed by co-treatment with SB525334. CG injection was associated with an increase in peritoneal fibrosis and thickness, which functionally resulted in an increase in the glucose absorption via peritoneum. Co-treatment with SB525334 attenuated these changes. The levels of EMT protein markers and immunohistochemical staining for fibrosis showed similar trends. Immunofluorescence staining for EMT markers showed induction of transformed cells with both epithelial and mesenchymal cell markers, which decreased upon co-treatment with SB525334. SB525334 effectively attenuated the TGF-β1-induced EMT in HPMCs. Cotreatment with SB525334 improved peritoneal thickness and fibrosis and recovered peritoneal membrane function in a peritoneal fibrosis mouse model.

Transforming Growth Factor-Beta1 and Human Gingival Fibroblast-to-Myofibroblast Differentiation: Molecular and Morphological Modifications

After oral mucosal injury, the healing response following specific steps that lead to wound closure and to tissue repair. Multiple cell populations are involved in this process; in particular, fibroblasts play a key role in the production of extracellular matrix (ECM). During wound healing the remodeling of ECM is a key stage to restore the tissue functionality through multifunctional fibroblast populations that are placed in the connective tissues of gingiva and periodontal ligament. Notably, a fibroblast sub-type (myofibroblast) is centrally involved in collagen synthesis and fibrillar remodeling. The present work evidenced the role of Transforming Growth Factor-beta1 (TGF-β1) to mediate human gingival fibroblasts (hGFs) differentiation into myofibroblasts derived from gingival fibroblasts (myo-hGFs). The morphological and functional features were analyzed through Confocal Laser Scanning Microscopy (CLSM), flow cytometry, and western blotting analyses. The specific markers, such as alpha-Smooth Muscle Actin (α-SMA), Vimentin, E-cadherin, β-catenin, and Smad 2/3, were modulated in myo-hGFs after the induction with TGF-β1, at different time points (24, 48, and 72 h). After 72 h of treatment TGF-β1 operates as an inducer of hGFs into myo-hGFs differentiation. We propose that TGF-β1 may promote in vitro the fibroblasts-to-myofibroblasts transition via the morphological and molecular modifications, as the induction of α-SMA, Vimentin, E-cadherin, β-catenin, and Smad 2/3.

Protective and anti-inflammatory effect of selenium nano-particles against bleomycin-induced pulmonary injury in male rats

Pulmonary fibrosis (PF) is an interstitial lung disease, in which the exact pathologic mechanisms are not fully understood. Drug trials for the treatment of PF have shown disappointing results and controversial. Recently, selenium nanoparticles (SeNPs) have received great attention for potential use in treatments, due to high bioactivity features and lower toxicity. This study evaluated the protective effect of SeNPs against pulmonary injury induced by bleomycin (single dose, 4 mg/kg, intratracheal) in male rats in early and late phases of the disease. The rats were treated with SeNPs by intraperitoneal injection (0.5 mg SeNP/kg) for five consecutive days in the early phase (a day after injection of bleomycin) and late phase (a week after injection of bleomycin). The results showed that injection of SeNPs in the early phase improved the degree of alveolitis and inflammation and lung structure damage. Also, led to significant decreases in density of transforming growth factor- β1 (TGF-β1) in the lung and tumor necrosis factor-α (TNF-α) levels in the serum and lung homogenates compared with bleomycin-administrated group. Notably, treatment with the SeNP during the late phase did not show any ameliorative effects. Thus, the data suggest that SeNP has a protective effect against bleomycin-induced pulmonary injury in rats in the early phase of the disease. This might mean that SeNPs may be a new therapeutic agent for the improvement of this disease in the early phases.

Anti-fibrotic Actions of Equine Interleukin-10 on Transforming Growth Factor-Beta1-Stimulated Dermal Fibroblasts Isolated From Limbs of Horses

Fibroproliferative disorders occur in both humans and horses following skin injury. In horses, wound healing on the limb is often complicated by the formation of fibroproliferative exuberant granulation tissue, characterized by persistent expression of pro-fibrotic transforming growth factor-beta1 (TGF-β1) and deficient expression of anti-inflammatory interleukin-10 (IL-10). IL-10 has been shown to directly modulate fibrotic gene expression in human fibroblasts, so we hypothesized that equine IL-10 (eIL-10) may exert similar anti-fibrotic effects on equine dermal fibroblasts. Cell-lines were created from the limb skin of six individual horses. Recombinant eIL-10 was produced and purified, and its effects on the cells investigated in the presence and absence of equine TGF-β1 (eTGF-β1). Myofibroblast differentiation and collagen production were examined using immunofluorescent cytometry, cell contractility in a collagen gel assay, and fibrotic gene expression using quantitative PCR. In response to eTGF-β1, fibroblasts increased in contractility and expression of alpha-smooth muscle actin, collagen types 1 and 3, and matrix metalloproteinase 1, 2, and 9. Equine IL-10 limited cell contractility and production of alpha-smooth muscle actin and type 3 collagen, and decreased mRNA levels of eCol3a1 and eMMP9, while increasing that of eMMP1. Opposing effects on eTGF-βR3 and eIL-10R1 gene expression were also observed, with mRNA levels decreasing following eTGF-β1 treatment, and increasing with eIL-10 treatment. These findings indicate that eIL-10 limits the pro-fibrotic effects of eTGF-β1, potentially through the modulation of fibrotic and receptor gene expression. Further investigations are warranted to assess the therapeutic utility of eIL-10 in the treatment of exuberant granulation tissue.

Relationship between Helicobacter pylori cagA Genotypes Infection and IL-10 and TGFβ1 Genes' Expression in Gastric Epithelial Cells

Background

The correlation of Helicobacter pylori infection with gastritis, peptic ulcer, and gastric cancer has been proven. The aim of this study was to determine the effects of cagA ⁺ and cagA ^- genotypes of H. pylori on genes expression of interleukin (IL) -10 and tumor growth factor (TGF) β1 in gastric epithelial cells of patients with gastritis and H. pylori infection.

Methods

In all, 45 gastric biopsy samples were collected from patients with gastritis and H. pylori infection admitted to Tohid Hospital in Sanandaj city. Status of urease and cagA genes of H. pylori were directly determined from the biopsy samples using polymerase chain reaction (PCR) method. Expression of IL-10 and TGF-β1 genes in gastric epithelial cells of patients with gastritis and cagA ⁺ and cagA^- genotypes of H. pylori infection was serveyed using real-time PCR method.

Results

Overall, 25 samples had infection with H. pylori cagA ⁺ and 20 with cagA ^- genotypes. This study showed that there is a positive correlation between cagA ^- genotypes of H. pylori and increasing of IL-10 gene expression in gastric epithelial cells of patients with gastritis (P = 0.001).

Conclusions

Level of gene expression of IL-10 as an anti-inflammatory cytokine in gastric epithelial cells of patients with H. pylori infection is connected to cagA- genotypes.

Empagliflozin Protects Against Proximal Renal Tubular Cell Injury Induced by High Glucose via Regulation of Hypoxia-Inducible Factor 1-Alpha

BACKGROUND

Evidence from both animal and human studies clearly supports the renal beneficial effects of empagliflozin (emp), a sodium glucose co-transporter 2 (SGLT2) inhibitor, but the mechanism in which it exerts its effect is not well understood. In this study, we investigated the capability of emp on reducing hyperglycemia-induced renal proximal tubular epithelial cells injury and we evaluated if the renoprotective effect of emp associates with hypoxia-inducible factor-1α (HIF-1α).

MATERIALS AND METHODS

Human kidney cell lines (HK-2 cells) were incubated in normoxia, high glucose with or without emp treatment for 72 hours to evaluate the induction of HIF-1α, glucose transporter-1, SGLT2, the fibrosis signal pathway and epithelial-mesenchymal transition (EMT) markers.

RESULTS

High glucose (HG) increased expression of Collagen IV, Fibronectin, transforming growth factor-beta1 (TGF-β1). However, emp treatment remarkably decreased expression of TGF-β1, accumulation of extracellular matrix proteins (Fibronectin, Collagen IV), as well as (phosphorylated-smad3) P-smad3. HG increased SGLT2 protein expression compared to normal glucose (NG) while emp significantly decreased SGLT2 expression. Furthermore, emp decreased high glucose-induced alpha-smooth muscle actin (α-SMA) expression and reversed epithelial marker (E-catherin) suppression induced by high glucose. In addition, emp treatment for 72 h increased expression of HIF-1α protein (95% CI: -0.5918 to -0.002338, at 100nM, P < 0.05, 95% CI -0.6631 to -0.07367 at 500nM, P < 0.05) in hyperglycemic normoxic HK-2 cells. Furthermore, we observed increased expression of GLUT-1 protein after emp treatment and remarkably decreased cell proliferation.

CONCLUSION

Emp treatment protected proximal renal tubular cells injury induced by high glucose. Induction of HIF-1α expression by emp may play an essential role in the protection of high glucose-induced proximal renal tubular epithelial cells injury.

C-reactive protein promotes inflammation through TLR4/NF-κB/TGF-β pathway in HL-1 cells

Atrial fibrillation (AF) is the most common type of heart arrhythmia. Currently, the pathogenesis of AF is not fully understood yet. A growing body of evidence highlighted the strong association between inflammation and the pathogenesis of AF. C-reactive protein (CRP) is an inflammation marker with increased expression in AF. Therefore, the aim of this study was to determine if CRP promotes inflammation, which may sequentially mediate the onset of AF and the concurrent atrial fibrosis, through TLR4/NF-κB/TGF-β pathway. HL-1 cells were treated with either 25 or 50 μg/ml recombinant human CRP. TGF-β1 and NF-κB inhibitors were given either solely or together to the 50 μg/ml CRP-treated cells. Cell proliferation, apoptosis, the expression of apoptotic factors and TLR4, IL-6, TGF-β1, Smad2, and the phosphorylation of Smad2 were determined. Data showed that CRP induced dose-dependent inhibition on cell proliferation and promoted cell apoptosis, which was induced through both intrinsic and extrinsic pathways. Such effects were reversed by inhibiting TGF-β1 and/or NF-κB. Inhibition of TGF-β1 and/or NF-κB also reduced the expression of TLR4 and IL-6. Inhibition of NF-κB alone weakened the expression of TGF-β1 and phosphorylation of Smad2. Our study demonstrated that CRP is not only a marker, but also an important mediator in the induction of inflammation and likely the pathogenesis of AF. We for the first time reported CRP-induced activation and cross-talk between TLR4 and NF-κB/TGF-β1 signaling pathway in a cardiomyocyte model. Reducing CRP and targeting TLR4/NF-κB/TGF-β1 pathway may provide new insights in the therapeutic interventions to inflammation-induced AF.

The Cocktail Effect of BMP-2 and TGF-β1 Loaded in Visible Light-Cured Glycol Chitosan Hydrogels for the Enhancement of Bone Formation in a Rat Tibial Defect Model

Bone tissue engineering scaffolds offer the merits of minimal invasion as well as localized and controlled biomolecule release to targeted sites. In this study, we prepared injectable hydrogel systems based on visible light-cured glycol chitosan (GC) hydrogels containing bone morphogenetic protein-2 (BMP-2) and/or transforming growth factor-beta1 (TGF-β1) as scaffolds for bone formation in vitro and in vivo. The hydrogels were characterized by storage modulus, scanning electron microscopy (SEM) and swelling ratio analyses. The developed hydrogel systems showed controlled releases of growth factors in a sustained manner for 30 days. In vitro and in vivo studies revealed that growth factor-loaded GC hydrogels have no cytotoxicity against MC3T3-E1 osteoblast cell line, improved mRNA expressions of alkaline phosphatase (ALP), type I collagen (COL 1) and osteocalcin (OCN), and increased bone volume (BV) and bone mineral density (BMD) in tibia defect sites. Moreover, GC hydrogel containing BMP-2 (10 ng) and TGF-β1 (10 ng) (GC/BMP-2/TGF-β1-10 ng) showed greater bone formation abilities than that containing BMP-2 (5 ng) and TGF-β1 (5 ng) (GC/BMP-2/TGF-β1-5 ng) in vitro and in vivo. Consequently, the injectable GC/BMP-2/TGF-β1-10 ng hydrogel may have clinical potential for dental or orthopedic applications.

Chronic obstructive sleep apnea accelerates pulmonary remodeling via TGF-β/miR-185/CoLA1 signaling in a canine model

Chronic obstructive sleep apnea syndrome (OSAS) is considered to be associated with pulmonary diseases. However, the roles and mechanisms of OSA in pulmonary remodeling remain ambiguous. Thus, this study was aimed to elucidate the morphological and mechanical action of OSA in lung remodeling. In the present study, we employed a novel OSA model to mimic the OSA patient and investigate the role of OSA in pulmonary remodeling. We showed that pulmonary artery pressure of OSA group has no significant increased compared with the sham group. Nevertheless, we found that fibrotic tissue was predominantly located around the bronchi and vascular in the lung. Additionally, inflammatory cell infiltration was also detected in the peribonchial and perivascular space. The morphological change in OSA canines was ascertained by ultrastructure variation characterized by mitochondrial swelling, lamellar bodies degeneration and vascular smooth muscle incrassation. Moreover, sympathetic nerve sprouting was markedly increased in OSA group. Mechanistically, we showed that several pivotal proteins including collagen type I(CoLA1), GAP-43, TH and NGF were highly expressed in OSA groups. Furthermore, we found OSA could activated the expression of TGF-β, which subsequently suppressed miR-185 and promoted CoL A1 expression. This signaling cascade leads to pulmonary remodeling. In conclusion, Our data demonstrates that OSA can accelerate the progression of pulmonary remodeling through TGF-β/miR-185/CoLA1 signaling, which would potentially provide therapeutic strategies for chronic OSAS.

Involvement of Rho-associated coiled-coil kinase signaling inhibition in TGF-β1/Smad2, 3 signal transduction in vitro

AIM

To research the effect of Y-27632, a selective Rho-associated coiled-coil kinase (ROCK) inhibitor, on TGF-β1/Smad2, 3 signal transduction in ocular Tenon's capsule fibroblasts (OTFs).

METHODS

Primary ocular Tenon's capsule fibroblasts had been cultured in vitro. The effect of Y27632 on proliferation of OTF stimulated by lysophosphatidic acid (LPA) was evaluated by MTT colorimetric assay so as to sift out the proper concentrations range of Y-27632 for the next experiment. Real time-polymerase chain reactor (RT-PCR) was to analyze the changes of Smad2 and Smad3 genes of cells affected by Y-27632, though unaffected by transforming growth factor-beta1 (TGF-β1). Proteins of Smad2, Smad3, phosphorylated Smad2 (Ser245/250/255), and phosphorylated Smad3 (Ser423/425/203) were respectively quantified by Western blot after OTFs were successively incubated by TGF-β1 and Y-27632. Meanwhile, α-smooth muscular actin (α-SMA) protein was also quantified after the small intervening gene fragments of human Smad2 and Smad3 were designed, synthesized, and then transfected to OTFs.

RESULTS

Y-27632 significantly inhibited OTFs proliferation stimulated by LPA. Also Y-27632 significantly suppressed the expressions of Smad2 mRNA, Smad2, 3 proteins expressions, Smad3 phosphorylation at the carboxylic terminals of Ser423/425/203 which had been radically promoted by TGF-β1. SiRNA-Smad2, 3 suppressed α-SMA expressions, but less effectively than Y-27632.

CONCLUSION

The inhibition of ROCK signaling may be a potential therapeutic candidate for the treatment of the filtration channel fibrosis.

TGF-β1 -509C/T polymorphism and susceptibility to keloid disease: a systematic review and meta-analysis

Background:

Keloid disease (KD) is common and often refractory to treatment. Definition of the genetic mechanisms of KD can lead to a better understanding of the disease and suggest more effective treatment strategies.

Objectives:

To quantitatively estimate the association between KD susceptibility and the -509C/T polymorphism in the TGF-β1 gene.

Methods:

PubMed, Embase and CNKI databases were searched using a combination of the Medical Subject Headings (MeSH) and relevant words in titles. Analyses were performed with STATA 12.0.

Results:

Five case-control studies encompassing a total of 564 keloid cases and 620 healthy controls were pooled in the final meta-analysis. Among the five studies, no significant association was detected between the TGF-β1 -509C/T polymorphism and KD under all of the five genetic models (allele comparison, heterozygote comparison, homozygote comparison, dominant model and recessive model) for the overall analyses and for the subgroup analyses based on DNA extraction method, participant ethnicity and group size. When stratified by study quality, three high-quality studies showed significant association under allele comparison and homozygote model (C versus T: OR = 0.80, 95% confidence interval [CI] = 0.65–0.98, P = 0.03; I² = 0%, P = 0.64; CC versus TT: OR = 0.62, 95% CI = 0.41–0.94, P = 0.02; I² = 0%, P = 0.79); while two moderate-quality studies showed significant association under allele comparison, homozygote model and recessive model (C versus T: OR = 1.52, 95% CI = 1.15–2.01, P = 0.004; I² = 39%, P = 0.20; CC versus TT: OR = 2.14, 95% CI = 1.24–3.70, P = 0.02; I² = 19%, P = 0.27; CC versus CT+TT: OR = 2.04, 95% CI = 1.29–3.24, P = 0.002; I² = 0%, P = 0.35).

Conclusions:

The current meta-analysis suggests that the TGF-β1 -509C/T polymorphism is not associated with KD susceptibility. High-quality and large-scale studies are needed to validate our findings.

Keloid scars are thick and lumpy scars that behave almost like tumours. They grow, are unsightly and itchy, and difficult to treat as they can get worse after attempts at treating them. This article reviews the scientific evidence for a link between a certain gene variation, specifically `509C/T polymorphism in the TGF-β1 gene’. After an extensive scientific database search, five studies were found, and no significant association was detected between the TGF-β1 -509C/T polymorphism and Keloid scarring. High quality and large-scale studies are needed to validate our findings.

Role of endothelial-to-mesenchymal transition induced by TGF-β1 in transplant kidney interstitial fibrosis

Chronic allograft dysfunction (CAD) induced by kidney interstitial fibrosis is the main cause of allograft failure in kidney transplantation. Endothelial‐to‐mesenchymal transition (EndMT) may play an important role in kidney fibrosis. We, therefore, undertook this study to characterize the functions and potential mechanism of EndMT in transplant kidney interstitial fibrosis. Proteins and mRNAs associated with EndMT were examined in human umbilical vein endothelial cells (HUVECs) treated with transforming growth factor‐beta1 (TGF‐β1) at different doses or at different intervals with western blotting, qRT‐PCR and ELISA assays. Cell motility and migration were evaluated with motility and migration assays. The mechanism of EndMT induced by TGF‐β1 was determined by western blotting analysis of factors involved in various canonical and non‐canonical pathways. In addition, human kidney tissues from control and CAD group were also examined for these proteins by HE, Masson's trichrome, immunohistochemical, indirect immunofluorescence double staining and western blotting assays. TGF‐β1 significantly promoted the development of EndMT in a time‐dependent and dose‐dependent manner and promoted the motility and migration ability of HUVECs. The TGF‐β/Smad and Akt/mTOR/p70S6K signalling pathways were found to be associated with the pathogenesis of EndMT induced by TGF‐β1, which was also proven in vivo by the analysis of specimens from the control and CAD groups. EndMT may promote transplant kidney interstitial fibrosis by targetting the TGF‐β/Smad and Akt/mTOR/p70S6K signalling pathways, and hence, result in the development of CAD in kidney transplant recipients.

Transforming growth factor-β1 and TGF-β2 act synergistically in the fibrotic pathway in oral submucous fibrosis: An immunohistochemical observation

Background and objectives:

Oral Submucous Fibrosis (OSF) is a potentially malignant oral disorder which leads to fibrosis of the oral mucosa and has a high rate of malignant transformation. The consumption of various forms of areca nut is causatively linked to the condition. The constituents of areca nut activate several pro-fibrotic cytokines, chiefly transforming growth factor-β1, β2, which leads to an increased deposition and decreased degradation of extracellular matrix and collagen. TGF-β1, β2 probably represent the major pathway in the deposition of collagen fibres in this condition. The present study aims to identify and correlate the expressions of TGF-β1 and TGF-β2 immunohistochemically on paraffin sections of various stages of OSF. A comparison was also made between normal oral mucosa and scar tissue and OSF to judge the mode, extent and type of expression of TGF β1, β2.

Methods:

The expression of TGF-β1 antibody (8A11, NovusBio, USA) and TGF-β2 antibody (TB21, NovusBio, USA) was detected immunohistochemically on paraffin sections of 58 and 70 cases of OSF respectively, 10 cases of normal oral mucosal tissue and 4 cases of scar tissue. A mapping of the positivity of the two cytokines was done using JenOptik camera and ProReg image analysis software. The results were statistically analysed using one way ANOVA and students “t” test.

Results:

Expression of TGF-β1 and TGF-β2 was more in OSF as compared with normal oral mucosa, scar/keloid tissue showing highest values. Positivity for both the markers was seen in epithelium, around the blood vessels, in areas of inflammatory infiltrate, fibroblasts and in muscles. TGF-β1 expression was higher and more intense than that of TGF-β2 in all the cases. TGF-β2 was restricted in its expression to submucosal area with minimal involvement of the epithelium and the deeper muscle tissue.

Conclusion:

TGF-β1 is the most prominent cytokine in the fibrotic pathway and TGF-β2 plays a contributory role.

Different localization and expression of protein kinase C-beta in kidney cortex of diabetic nephropathy mice and its role in telmisartan treatment

AIM

This study aims to investigate the localization and expression of protein kinase C-beta I and beta II in kidney cortex of diabetic nephropathy mice and their roles in telmisartan treatment.

METHODS

18 mice were randomly divided into three groups: normal group, diabetic nephropathy group and telmisartan-treated group. The localization and expression of protein kinase C-beta I and beta II were measured with confocal immunofluorescence laser scanning microscopy, immunohistochemistry and western blotting. The expression of transforming growth factor-beta 1 and vascular endothelial growth factor in glomeruli was detected by immunohistochemistry.

RESULTS

Compared to the normal mice, the expression and localization of protein kinase C-beta I and beta II are differed in diabetic nephropathy mice, with increased expression of protein kinase C-beta I but decreased level of protein kinase C-beta II. Meanwhile, the expression of transforming growth factor-beta 1 and vascular endothelial growth factor showed increase in the glomeruli of diabetic nephropathy, compared to the controls. Also, protein kinase C-beta I exhibited a positive correlation to transforming growth factor-beta 1 (r = 0.649, P = 0.030), but no correlation to vascular endothelial growth factor (r = 0.387, P = 0.079). Telmisartan treatment exercised significant beneficial role in diabetic nephropathy, which is associated with protein kinase C-beta I, but not beta II.

CONCLUSIONS

The expression and localization of protein kinase C-beta I and beta II differ in the diabetic nephropathy, and such difference is associated with the pathogeneses of diabetic nephropathy.

Endogenous versus exogenous growth factor regulation of articular chondrocytes

Anabolic growth factors that regulate the function of articular chondrocytes are candidates for articular cartilage repair. Such factors may be delivered by pharmacotherapy in the form of exogenous proteins, or by gene therapy as endogenous proteins. It is unknown whether delivery method influences growth factor effectiveness in regulating articular chondrocyte reparative functions. We treated adult bovine articular chondrocytes with exogenous recombinant insulin-like growth factor-I (IGF-I) and transforming growth factor-beta1 (TGF-β1), or with the genes encoding these growth factors for endogenous production. Treatment effects were measured as change in chondrocyte DNA content, glycosaminoglycan production, and aggrecan gene expression. We found that IGF-I stimulated chondrocyte biosynthesis similarly when delivered by either exogenous or endogenous means. In contrast, exogenous TGF-β1 stimulated these reparative functions, while endogenous TGF-β1 had little effect. Endogenous TGF-β1 became more bioactive following activation of the transgene protein product. These data indicate that effective mechanisms of growth factor delivery for articular cartilage repair may differ for different growth factors. In the case of IGF-I, gene therapy or protein therapy appear to be viable options. In contrast, TGF-β1 gene therapy may be constrained by a limited ability of chondrocytes to convert latent complexes to an active form.

Overexpression of cyclooxygenase-2 and transforming growth factor-beta 1 is an independent predictor of poor virological response to interferon therapy in chronic HCV genotype 4 patients

BACKGROUND/AIMS

COX-2 and TGF-β1 are overexpressed in hepatitis C virus (HCV) infection and are related to hepatitis pathogenesis and hepatic fibrosis. The current study investigated the relationship between pretreatment COX-2 and TGF-β1 hepatic expression in HCV genotype 4 and the virological response to interferon therapy.

PATIENTS AND METHODS

Liver biopsies of 55 patients with HCV infection genotype 4 were selected together with 10 liver biopsies as control. The patients' clinicopathological data were collected. Immunohistochemistry was done using anti-COX-2 and anti-TGF-β1 antibodies. Statistical tests were used to determine the association between both COX-2 and TGF-β1 expression in relation to clinicopathological parameters and response to interferon therapy.

RESULTS

COX-2 was upregulated especially in nonresponders and was an independent predictor of poor virological response. However, COX-2 showed no association with other clinicopathological features. TGF-β1 was upregulated and associated with nonresponders, histological activity, and fibrosis stage. There was no association between TGF-β1 and other clinicopathological features. There was an association between COX-2 and TGF-β1 immunoexpression.

CONCLUSION

Overexpression of COX-2 and TGF-β1 is an independent predictor for poor outcome of interferon and ribavirin therapy and these might be useful markers for the response to treatment. Both molecules are associated together; however, their role during hepatitis treatment has to be clarified.

Attenuation of diabetic nephropathy by Chaihuang-Yishen granule through anti-inflammatory mechanism in streptozotocin-induced rat model of diabetics

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medical herbs have been used in China for a long time to treat different diseases. Based on traditional Chinese medicine (TCM) principle, Chaihuang-Yishen granule (CHYS) was developed and has been employed clinically to treat chronic kidney disease including diabetic nephropathy (DN). The present study was designed to investigate its mechanism of action in treatment of DN.

MATERIALS AND METHODS

Diabetic rats were established by having a right uninephrectomy plus a single intraperitoneal injection of STZ. Rats were divided into four groups of sham, diabetes, diabetes with CHYS and diabetes with fosinopril. CHYS and fosinopril were given to rats by gavage for 20 weeks. Samples from blood, urine and kidney were collected for biochemical, histological, immunohistochemical and molecular analyses.

RESULTS

Rats treated with CHYS showed reduced 24h urinary protein excretion, decreased serum TC and TG levels, but CHYS treatment did not affect blood glucose level. Glomerular mesangial expansion and tubulointerstitial fibrosis in diabetic rats were significantly alleviated by CHYS treatment. Moreover, CHYS administration markedly reduced mRNA levels of NF-κB p65 and TGF-β1, as well as decreased protein levels of NF-κB p65, MCP-1, TNF-α and TGF-β1 in the kidney of diabetic rats.

CONCLUSIONS

CHYS ameliorates renal injury in diabetic rats through reduction of inflammatory cytokines and their intracellular signaling.

Curcumin ameliorates intrahepatic angiogenesis and capillarization of the sinusoids in carbon tetrachloride-induced rat liver fibrosis

Neoangiogenesis and the development of an abnormal angio-architecture in the liver are strongly linked with progressive fibrogenesis. This study aimed to evaluate the ability of curcumin to protect liver fibrosis-associated angiogenesis and capillarization of the sinusoids in experimental rats. Liver fibrosis was induced by intraperitoneal injection of carbon tetrachloride (CCl₄) with or without curcumin for 6 weeks. The results suggest that curcumin treatment markedly attenuated CCl₄-induced liver fibrosis, as assessed by histology and hydroxyproline content, and inhibited hepatic stellate cell activation. Curcumin ameliorated hepatic angiogenesis, as assessed by measuring microvessel density using Von Willebrand factor staining and by examining the expression of the endothelial cell markers CD31 and vascular endothelial growth factor receptor (VEGFR)-2 in the livers. Pathologic remodeling of liver sinusoidal capillarization, as assessed by electron-microscopic analysis of Disse's space and by evaluation of the levels of basement membrane protein expression, was also attenuated by curcumin administration. The intrahepatic gene or protein expression of hypoxia-inducible factor-1α, VEGFR-1, placental growth factor, and cyclooxygenase-2 decreased with treatment with curcumin in fibrotic rats. In conclusion, curcumin ameliorates hepatic angiogenesis and sinusoidal capillarization in CCl₄-induced rat liver fibrosis through suppressing multiple proangiogenic factors.

AEG-1 participates in TGF-beta1-induced EMT through p38 MAPK activation

Epithelial-mesenchymal transition (EMT) is an important cellular event in organogenesis, cancer and renal tubulointerstitial fibrosis. Transforming growth factor-beta1 (TGF-beta1) is the key inducer of EMT and the p38 mitogen-activated protein kinases (p38 MAPK), an major intracellular signal transduction pathway is involved in TGF-beta1-induced EMT. Astrocyte elevated gene-1 (AEG-1) represents an chief genetic determinant regulating multiple events in tumorigenesis. Our present study is to explore the role of AEG-1 in TGF-beta1-induced p38 MAPK activation and EMT process in human renal tubular epithelial (HK-2) cells. The protein expressions of AEG-1, the markers of EMT and p38 phosphorylation were measured by Western blot. The protein expression of AEG-1 was increased in HK-2 cells treated with TGF-beta1. Knockdown of AEG-1 potently inhibited phosphorylation of p38 MAPK and reversed TGF-beta1-induced EMT. Over-expression of AEG-1 via AEG-1 transfection elicited p38 MAPK phosphorylation and promoted EMT. The effects of AEG-1 during EMT were blocked by a p38-specific inhibitor. Our findings suggest that AEG-1 plays an important role in TGF-beta1-induced EMT through activation of p38 MAPK in proximal tubular epithelial cells.

Rapamycin inhibits transforming growth factor β1-induced fibrogenesis in primary human lung fibroblasts

PURPOSE

The present study was designed to determine whether rapamycin could inhibit transforming growth factor β1 (TGF-β1)-induced fibrogenesis in primary lung fibroblasts, and whether the effect of inhibition would occur through the mammalian target of rapamycin (mTOR) and its downstream p70S6K pathway.

MATERIALS AND METHODS

Primary normal human lung fibroblasts were obtained from histological normal lung tissue of 3 patients with primary spontaneous pneumothorax. Growth arrested, synchronized fibroblasts were treated with TGF-β1 (10 ng/mL) and different concentrations of rapamycin (0.01, 0.1, 1, 10 ng/mL) for 24 h. We assessed m-TOR, p-mTOR, S6K1, p-S6K1 by Western blot analysis, detected type III collagen and fibronectin secreting by ELISA assay, and determined type III collagen and fibronectin mRNA levels by real-time PCR assay.

RESULTS

Rapamycin significantly reduced TGF-β1-induced type III collagen and fibronectin levels, as well as type III collagen and fibronectin mRNA levels. Furthermore, we also found that TGF-β1-induced mTOR and p70S6K phosphorylation were significantly down-regulated by rapamycin. The mTOR/p70S6K pathway was activated through the TGF-β1-mediated fibrogenic response in primary human lung fibroblasts.

CONCLUSION

These results indicate that rapamycin effectively suppresses TGF-β1-induced type III collagen and fibronectin levels in primary human lung fibroblasts partly through the mTOR/p70S6K pathway. Rapamycin has a potential value in the treatment of pulmonary fibrosis.

Amitriptyline aggravates the fibrosis process in a rat model of infravesical obstruction

Infravesical obstruction (IVO) secondary to benign prostatic hypertrophy can affect up to 50% of men over 50 years old and may cause serious and irreversible alterations throughout the urinary tract, especially in the bladder. Therapeutic approaches are currently limited. Amitriptyline has recently been described as an analgesic, anti-inflammatory and myorelaxant in some experimental models. The objective of this study was to investigate the effects of amitriptyline hydrochloride on the process of fibrosis in a bladder outlet obstruction model in rats. Male Wistar rats were subjected to IVO and studied at intervals of 1 and 14 days postprocedure. The rats were randomly divided into five groups: sham, IVO1-T, IVO1-NT, IVO14-T and IVO14-NT. Bladder tissue was processed for histopathology, immunohistochemistry and RT-PCR. The IVO14 groups presented bladder fibrosis, smooth muscle cell hypertrophy and bladder wall thickening. The IVO14-T group demonstrated a higher intensity of fibrosis, higher macrophage infiltration rate and higher gene expression of Transforming growth factor (TGF) Tgf-β1. Thus this data shows that in this experimental mode amitriptyline had an amplifying effect on the process of fibrosis as a whole.

Local administration of carbon monoxide inhibits neointima formation in balloon injured rat carotid arteries

Recent studies indicate that systemic induction of heme oxygenase-1 (HO-1), which oxidatively degrades heme into iron, biliverdin, and carbon monoxide (CO), or adenoviral-mediated gene transfer of HO-1 inhibits neointima formation after experimental vascular injury. In the present study, we investigated whether the acute, local administration of the HO-1 product, CO, regulates the arterial remodeling response following injury. Immediately after balloon injury of rat carotid arteries, a saturated solution of CO or nitrogen (N2), or phosphate buffered saline (PBS) was incubated luminally within the injured vessels for 30 min. Two weeks after injury, arteries exposed to CO exhibited significantly reduced neointimal area, neointimal area/medial wall area ratio, neointimal thickness, and medial wall area compared to arteries exposed to N2 or PBS. Arteries exposed to CO also demonstrated significantly reduced DNA synthesis in the medial wall two days after injury as suggested by proliferating cell nuclear antigen immunostaining, and this was associated with a decrease in the protein expression of the G1 cyclins, cyclin E and A, and transforming growth factor-beta1. These results indicate that the acute, local delivery of CO blocks the pathophysiological remodeling response to vascular injury, and identifies CO as a potentially important therapeutic agent in the treatment of vasculoproliferative disease.