Transforming growth factor-β and fibrosis

Revisiting Cell Death Responses in Fibrotic Lung Disease: Crosstalk between Structured and Non-Structured Cells

Fibrosis is a life-threatening disorder caused by excessive formation of connective tissue that can affect several critical organs. Innate immune cells are involved in the development of various disorders, including lung fibrosis. To date, several hematopoietic cell types have been implicated in fibrosis, including pro-fibrotic monocytes like fibrocytes and segregated-nucleus-containing atypical monocytes (SatMs), but the precise cellular and molecular mechanisms underlying its development remain unclear. Repetitive injury and subsequent cell death response are triggering events for lung fibrosis development. Crosstalk between lung structured and non-structured cells is known to regulate the key molecular event. We recently reported that RNA-binding motif protein 7 (RBM7) expression is highly upregulated in the fibrotic lung and plays fundamental roles in fibrosis development. RBM7 regulates nuclear degradation of NEAT1 non-coding RNA, resulting in sustained apoptosis in the lung epithelium and fibrosis. Apoptotic epithelial cells produce CXCL12, which leads to the recruitment of pro-fibrotic monocytes. Apoptosis is also the main source of autoantigens. Recent studies have revealed important functions for natural autoantibodies that react with specific sets of self-antigens and are unique to individual diseases. Here, we review recent insights into lung fibrosis development in association with crosstalk between structured cells like lung epithelial cells and non-structured cells like migrating immune cells, and discuss their relevance to acquired immunity through natural autoantibody production.

Biological effects of a new ultraviolet A1 prototype based on light-emitting diodes on the treatment of localized scleroderma

Ultraviolet A₁ (UVA₁ ) phototherapy (spectral range 340-400 nm) is a well-established treatment option for various skin diseases such as localized scleroderma. Recent improvements of conventional UVA₁ light sources (metal-halide or fluorescent lamps) have brought attention to a new light-emitting diode (LED) technology with remarkable advantages in handling and clinical routine. This study provides a preclinical histological and molecular evaluation of an LED-based UVA₁ prototype with a narrower spectral range (360-400 nm) for treating localized scleroderma. Scleroderma mouse models and fibroblasts in vitro were exposed to LED-based UVA₁ phototherapy or to irradiation with a commercially available metal-halide lamp emitting low-dose (20, 40 J/cm² ), medium-dose (60 J/cm² ) and high-dose (80, 100 J/cm² ) UVA₁ light. Both UVA₁ light sources affected inflammatory genes (IL-1α and IL-6) and growth factors (TGFß-1 and TGFß-2). Increased collagen type 1 was reduced after UVA₁ phototherapy. Matrix metalloproteinase-1 was more enhanced after a medium dose of LED-based UVA₁ phototherapy than after conventional treatment. In vivo, dermal thickness and the amount of collagen were reduced after both treatment methods. Remarkably, myofibroblasts were more effectively reduced by a medium dose of LED-based UVA₁ phototherapy. The study indicates that LED-based UVA₁ phototherapy yields similar or even better results than conventional treatment. In terms of biosafety and patient comfort, LED-based UVA₁ phototherapy offers clear advantages over conventional treatment because of the use of a narrower and less harmful UVA₁ spectrum, less heat generation and shorter treatment times at the same irradiation intensity. Clinical studies are required to confirm these results in patients with localized scleroderma.

Protective effect of miRNA-containing extracellular vesicles derived from mesenchymal stromal cells of old rats on renal function in chronic kidney disease

Introduction

Mesenchymal stromal cells (MSCs) play an important role in the prevention of cell and tissue fibrosis. Senescence may decrease the function of MSCs during recovery from tissue and organ damage. Extracellular vesicles (EVs) released from MSCs contribute to the repair of kidney injury. We explored the influence of senescence on EVs derived from MSCs (MSC-EVs) and detected the protective effects of MSC-EVs expressing low levels of miR-294/miR-133 derived from old rats against chronic kidney disease (CKD).

Methods

The effects of MSC-EVs derived from 3-month-old and 18-month-old male Fisher 344 rats on renal fibrosis were explored in a unilateral ureteral obstruction (UUO) model. pLV-miR-294/pLV-miR-133 mimic/inhibitor were injected into young and old rats before UUO to detect the effects of miR-294/miR-133, which were decreased in MSC-EVs and sera from old rats, on renal function in CKD. Transforming growth factor-β1 (TGF-β1)-induced human renal proximal tubular epithelial (HK2) cells were used to imitate the pathological process of renal fibrosis in vitro. Western blotting was used to assess the expression of epithelial/mesenchymal markers and phosphorylation of proteins in HK2 cells.

Results

The inhibition of UUO-induced CKD by MSC-EVs was weaker in old rats than in young rats. Downregulation of miRNAs (miR-294 and miR-133) in both MSC-EVs and sera from old rats obviously attenuated UUO-induced renal injury in old rats. miR-294 and miR-133 overexpression mitigated TGF-β1-mediated epithelial-mesenchymal transition (EMT) in HK2 cells, and the obvious increase in the phosphorylation of both SMAD2/3 and ERK1/2 induced by TGF-β1 was prevented in miR-294- and miR-133-overexpressing HK2 cells.

Conclusions

The ability of MSC-EVs to inhibit renal fibrosis decreased with age. miR-294/miR-133 in MSC-EVs and sera had an important effect on renal fibrosis in old rats and on EMT in HK2 cells. Furthermore, miR-294/miR-133 overexpression prevented SMAD2/3 and ERK1/2 phosphorylation in HK2 cells during TGF-β1-mediated EMT. These findings show that miR-294/miR-133 may be therapeutic in renal fibrosis and related renal dysfunction in elderly individuals.

Immune response and Raman scattering assessment in rats skin after contact with Fusarium oxysporum metabolites

The secondary metabolites produced by Fusarium can cause disease and death when consumed and produce biological responses even in the absence of the microorganism. The IL-6, TNF-α and TGF-β1 cytokines immune reactivity was associated with histopathological and physico-chemical changes in skin of immune competent rats after administration of Fusarium oxysporum crude extract. Rats were intradermally injected with 50 μl of 0.5 mg/ml crude extract and were euthanized at 3, 6, 12 and 24 h after injection. The inflammatory response was quantified by enzyme myeloperoxidase activity and by immunohistochemical method to detect the IL-6, TNF-α and TGF-β1. Physico-chemical analysis was performed using FT-Raman Spectroscopy. The inflammatory response was most intense at 6 and 12 h after crude extract administration and the most significant histopathological changes were observed in the dermis. Myeloperoxidase activity was intense from 3 to 24 h after injection. The immunostaining of pro-inflammatory cytokines IL-6 and TNF-α peaked at 6 h. Immunostaining for TGF-β1 was highest at 12 and 24 h. FT-Raman spectral analysis showed both, the most intense Fusarium interaction with the skin at 6 h, as revealed by the changes in the stretching of -CH bands (3100-2800 cm^-1) in the dermis, and skin recovery trending after 12 h after crude extract injection. The results showed that secondary metabolites stimulated histopathologic changes and inflammatory responses even in the absence of the fungus, increasing myeloperoxidase activity and pro-inflammatory cytokine expression besides promoting physico-chemical changes.

Levofloxacin nanoemulsion gel has a powerful healing effect on infected wound in streptozotocin-induced diabetic rats

The aim of this study was to develop a novel oil-in-water (o/w) nanoemulsion gel containing levofloxacin for enhanced topical efficacy. Average particle size of sesame oil nanoemulsion without (SONE) and containing levofloxacin (SONEL) was found as 25.2 and 26.3 nm, respectively. Results from scratch test showed that SONEL had better proliferation effect in comparison with negative control. Treated animals with SONEL showed significant reduction in period of epithelialization, wound contraction, and number of inflammatory cells among all groups. Also, SONEL-treated group had the greatest collagen synthesis. Immunohistochemical analysis showed high intensity of CD31 and TGF-β at wound site of treatment groups with SONEL on day 12 post-treatment (P < 0.05). Skin irritation test demonstrated safety of SONEL gel for skin topical application. In conclusion, our studies suggest that SONEL could be an effective formulation for treatment of diabetic wound infection by controlling infection and improving the healing process. Graphical Abstract .

Exogenous dihydrosphingosine 1 phosphate mediates collagen synthesis in cardiac fibroblasts through JAK/STAT signalling and regulation of TIMP1

Cardiac fibrosis and myocyte hypertrophy are hallmarks of the cardiac remodelling process in cardiomyopathies such as heart failure (HF). Dyslipidemia or dysregulation of lipids contribute to HF. The dysregulation of high density lipoproteins (HDL) could lead to altered levels of other lipid metabolites that are bound to it such as sphingosine-1- phosphate (S1P). Recently, it has been shown that S1P and its analogue dihydrosphingosine-1-phosphate (dhS1P) are bound to HDL in plasma. The effects of dhS1P on cardiac cells have been obscure. In this study, we show that extracellular dhS1P is able to increase collagen synthesis in neonatal rat cardiac fibroblasts (NCFs) and cause hypertrophy of neonatal cardiac myocytes (NCMs). The janus kinase/signal transducer and activator (JAK/STAT) signalling pathway was involved in the increased collagen synthesis by dhS1P, through sustained increase of tissue inhibitor of matrix metalloproteinase 1 (TIMP1). Extracellular dhS1P increased phosphorylation levels of STAT1 and STAT3 proteins, also caused an early increase in gene expression of transforming growth factor-β (TGFβ), and sustained increase in TIMP1. Inhibition of JAKs led to inhibition of TIMP1 and TGFβ gene and protein expression. We also show that dhS1P is able to cause NCM hypertrophy through S1P-receptor-1 (S1PR1) signalling which is opposite to that of its analogue, S1P. Taken together, our results show that dhS1P increases collagen synthesis in cardiac fibroblasts causing fibrosis through dhS1P-JAK/STAT-TIMP1 signalling.

Lung-targeted delivery of TGF-β antisense oligonucleotides to treat pulmonary fibrosis

Pulmonary fibrosis is a serious respiratory disease, with limited therapeutic options. Since TGF-β is a critical factor in the fibrotic process, downregulation of this cytokine has been considered a potential approach for disease treatment. Herein, we designed a new lung-targeted delivery technology based on the complexation of polymeric antisense oligonucleotides (pASO) and dimeric human β-defensin 23 (DhBD23). Antisense oligonucleotides targeting TGF-β mRNA were polymerized by rolling circle amplification and complexed with DhBD23. After complexation with DhBD23, pASO showed improved serum stability and enhanced uptake by fibroblasts in vitro and lung-specific accumulation upon intravenous injection in vivo. The pASO/DhBD23 complex delivered into the lung downregulated target mRNA, and subsequently alleviated lung fibrosis in mice, as demonstrated by western blotting, quantitative reverse-transcriptase PCR (qRT-PCR), immunohistochemistry, and immunofluorescence imaging. Moreover, as the complex was prepared only with highly biocompatible materials such as DNA and human-derived peptides, no systemic toxicity was observed in major organs. Therefore, the pASO/DhBD23 complex is a promising gene therapy platform with lung-targeting ability to treat various pulmonary diseases, including pulmonary fibrosis, with low side effects.

Administration of Steamed and Freeze-Dried Mature Silkworm Larval Powder Prevents Hepatic Fibrosis and Hepatocellular Carcinogenesis by Blocking TGF-β/STAT3 Signaling Cascades in Rats

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related deaths worldwide and the majority of HCC patients occur with a background of hepatic fibrosis and cirrhosis. We have previously reported the hepatoprotective effects of steamed and freeze-dried mature silkworm larval powder (SMSP) in a chronic ethanol-treated rat model. Here, we assessed the anti-fibrotic and anti-carcinogenic effects of SMSP on diethylnitrosamine (DEN)-treated rats. Wistar rats were intraperitoneally injected with DEN once a week for 12 or 16 weeks with or without SMSP administration (0.1 and 1 g/kg). SMSP administration significantly attenuated tumor foci formation and proliferation in the livers of the rats treated with DEN for 16 weeks. SMSP administration also inhibited hepatic fibrosis by decreasing the levels of collagen fiber and the expression of pro-collagen I and alpha-smooth muscle actin (α-SMA). Moreover, SMSP supplementation improved the major parameters of fibrosis such as transforming growth factor-β (TGF-β), connective tissue growth factor (CTGF), tumor necrosis factor-alpha (TNF-α), plasminogen activator inhibitor-1 (PAI-1), and collagen type I (Col1A1) in the livers from the rats treated with DEN for 16 weeks. As s possible mechanisms, we investigated the effects of SMSP on the TGF-β and signal transducer and activator of transcription 3 (STAT3)-mediated signaling cascades, which are known to promote hepatic fibrosis. We found that SMSP treatment inhibited the activation of TGF-β and the phosphorylation of STAT3 pathway in DEN-treated rats. Moreover, SMSP administration suppressed the expressions of the target genes of TGF-β and STAT3 induced by DEN treatment. Our findings provide experimental evidences that SMSP administration has inhibitory effects of hepatic fibrosis and HCC induced by DEN in vivo and could be a promising strategy for the prevention or treatment of hepatic fibrosis and hepatocellular carcinogenesis.

Altered expression of proteoglycan, collagen and growth factor genes in a TGF-β1 stimulated genetic risk model for musculoskeletal soft tissue injuries

OBJECTIVES

To investigate the functional effect of implicated variants within BGN and COL5A1 on gene expression of components of the extracellular matrix (ECM) in a TGF-β-stimulated risk model for musculoskeletal soft tissue injuries.

DESIGN

Experimental research, laboratory study.

METHODS

Skin biopsies were obtained from nine healthy participants with either a combined increased or reduced risk profile for COL5A1 rs12722 C>T and BGN rs1126499 C>T - rs1042103 G>A, and primary fibroblast cell lines were established. Total RNA was extracted at baseline (10% FBS), after serum starvation (1% FBS) and TGF-β1 treatment (1% FBS, 10ng/mL TGF-1β). Relative mRNA levels of BGN, COL5A1, DCN and VEGFA was quantified using Taqman® array pre-spotted plate assays (Applied Biosystems, Foster city, CA, USA).

RESULTS

At baseline, the reduced risk group had 2.5, 1.9 and 2 fold increases (p<0.001) in relative BGN, COL5A1 and VEGFA mRNA levels respectively. In the serum starved experiments, except for a significant 1.5 fold (p=0.017) increase in relative DCN mRNA expression in the reduced risk group, similar observations were noted for the other three genes. After TGF-1β treatment, the reduced risk group had 1.3 (p=0.011) and 1.4 fold (p=0.001) increases in the relative COL5A1 and VEGFA mRNA levels, respectively.

CONCLUSIONS

Altered mRNA levels associated with genetic risk profiles for musculoskeletal soft injury risk at baseline (BGN, COL5A1 and VEGFA), with serum starvation (DCN) and after TGF-β1 treatment (COL5A1 and VEGFA) provide additional functional evidence to support the association of implicated genetic loci with several musculoskeletal soft tissue injuries. Implication of altered gene expression profiles underpinning these genetic risk associated loci potentially highlight key therapeutic targets for management of these injuries.

Inhibition of plasminogen activator inhibitor-1 attenuates against intestinal fibrosis in mice

Background/Aims

Intestinal fibrosis is a major complication of Crohn’s disease (CD). The profibrotic protein transforming growth factor-β (TGF-β) has been considered to be critical for the induction of the fibrotic program. TGF-β has the ability to induce not only the expression of extracellular matrix (ECM) including collagen, but also the production of plasminogen activator inhibitor-1 (PAI-1) that prevents enzymatic degradation of the ECM during the onset of fibrotic diseases. However, the significance of PAI-1 in the developing intestinal fibrosis has not been fully understood. In the present study, we examined the actual expression of PAI-1 in fibrotic legion of intestinal inflammation and its correlation with the abnormal ECM deposition.

Methods

Chronic intestinal inflammation was induced in BALB/c mice using 8 repeated intrarectal injections of 2,4,6-trinitrobenzene sulfonic acid (TNBS). TM5275, a PAI-1 inhibitor, was orally administered as a carboxymethyl cellulose suspension each day for 2 weeks after the sixth TNBS injection.

Results

Using a publicly available dataset (accession number, GSE75214) and TNBS-treated mice, we observed increases in PAI-1 transcripts at active fibrotic lesions in both patients with CD and mice with chronic intestinal inflammation. Oral administration of TM5275 immediately after the onset of intestinal fibrosis upregulated MMP-9 (matrix metalloproteinase 9) and decreased collagen accumulation, resulting in attenuation of the fibrogenesis in TNBS-treated mice.

Conclusions

PAI-1-mediated fibrinolytic system facilitates collagen degradation suppression. Hence, PAI-1 inhibitor could be applied as an anti-fibrotic drug in CD treatment.

Topical administration of mangiferin promotes healing of the wound of streptozotocin-nicotinamide-induced type-2 diabetic male rats

Purpose: This study identifies the potential use of mangiferin gel to promote wound healing in diabetes mellitus (DM).Materials and methods: Male rats were rendered diabetes mellitus via intraperitoneal injection of streptozotocin and nicotinamide. Following diabetes development, wound was created at the back of the neck. 1% and 2% mangiferin gel and 1% silver sulphurdiazine (SS) gel (positive control) were applied to the wound for twenty-one (21) days. Fasting blood glucose (FBG) levels were weekly monitored. At the end of the treatment, rats were sacrificed and wound was excised and subjected for histopathological and molecular biological analysis.Results: No changes to serum FBG levels was noted throughout the period of mangiferin treatment. Albeit, a significant decrease in the size of the wound with increased in the skin thickness of surrounding the wound were observed. Increased expression and distribution of EGF, FGF, TGF-β, VEGF, PI3K, MMP and Nrf2 and decreased expression and distribution of TNFα and NF-κB p65 were observed in diabetic wound treated with topical mangiferin.Conclusions: Mangiferin has potential to be used as an agent to promote wound healing in diabetic condition.

Human Skin Keratinocytes on Sustained TGF-β Stimulation Reveal Partial EMT Features and Weaken Growth Arrest Responses

Defects in wound closure can be related to the failure of keratinocytes to re-epithelize. Potential mechanisms driving this impairment comprise unbalanced cytokine signaling, including Transforming Growth Factor-β (TFG-β). Although the etiologies of chronic wound development are known, the relevant molecular events are poorly understood. This lack of insight is a consequence of ethical issues, which limit the available evidence to humans. In this work, we have used an in vitro model validated for the study of epidermal physiology and function, the HaCaT cells to provide a description of the impact of sustained exposure to TGF-β. Long term TGF-β1 treatment led to evident changes, HaCaT cells became spindle-shaped and increased in size. This phenotype change involved conformational re-arrangements for actin filaments and E-Cadherin cell-adhesion structures. Surprisingly, the signs of consolidated epithelial-to-mesenchymal transition were absent. At the molecular level, modified gene expression and altered protein contents were found. Non-canonical TGF-β pathway elements did not show relevant changes. However, R-Smads experienced alterations best characterized by decreased Smad3 levels. Functionally, HaCaT cells exposed to TGF-β1 for long periods showed cell-cycle arrest. Yet, the strength of this restraint weakens the longer the treatment, as revealed when challenged by pro-mitogenic factors. The proposed setting might offer a useful framework for future research on the mechanisms driving wound chronification.

Evasion of apoptosis by myofibroblasts: a hallmark of fibrotic diseases

Organ fibrosis is a lethal outcome of autoimmune rheumatic diseases such as systemic sclerosis. Myofibroblasts are scar-forming cells that are ultimately responsible for the excessive synthesis, deposition and remodelling of extracellular matrix proteins in fibrosis. Advances have been made in our understanding of the mechanisms that keep myofibroblasts in an activated state and control myofibroblast functions. However, the mechanisms that help myofibroblasts to persist in fibrotic tissues remain poorly understood. Myofibroblasts evade apoptosis by activating molecular mechanisms in response to pro-survival biomechanical and growth factor signals from the fibrotic microenvironment, which can ultimately lead to the acquisition of a senescent phenotype. Growing evidence suggests that myofibroblasts and senescent myofibroblasts, rather than being resistant to apoptosis, are actually primed for apoptosis owing to concomitant activation of cell death signalling pathways; these cells are poised to apoptose when survival pathways are inhibited. This knowledge of apoptotic priming has paved the way for new therapies that trigger apoptosis in myofibroblasts by blocking pro-survival mechanisms, target senescent myofibroblast for apoptosis or promote the reprogramming of myofibroblasts into scar-resolving cells. These novel strategies are not only poised to prevent progressive tissue scarring, but also have the potential to reverse established fibrosis and to regenerate chronically injured tissues.

Effect of platelet-rich fibrin on cell proliferation, migration, differentiation, inflammation, and osteoclastogenesis: a systematic review of in vitro studies

Objective

To systematically assess the effects of platelet-rich fibrin (PRF) on in vitro cellular behavior.

Methods

A systematic electronic search using MEDLINE database was performed. In vitro studies using PRF were considered and articles published up to June 31, 2018 were screened. Eligible studies were selected based on the use of human PRF.

Results

In total, 1746 titles were identified with the search terms, from these 37 met the inclusion criteria and were chosen for data extraction. In addition, 16 new studies, mainly published in 2019, were also included in the analysis resulting in 53 studies. No meta-analysis could be performed due to the heterogeneity of study designs. Included studies show that PRF enhances proliferation, migration, adhesion, and osteogenic differentiation on a variety of cell types along with cell signaling activation. Furthermore, PRF reduces inflammation, suppresses osteoclastogenesis, and increases the expression of various growth factors in mesenchymal cells.

Summary and conclusions

Despite some notable differences of the studies, the overall findings suggest a positive effect of PRF on cell proliferation, migration, adhesion, differentiation, and inflammation pointing towards a therapeutic potential in regenerative dentistry.

Clinical relevance

PRF serves as a reservoir of bioactive molecules to support wound healing and bone regeneration. Although the cellular mechanisms by which PRF supports the clinical outcomes remain unclear, in vitro research provides possible explanations. This systematic review aims to provide an update of the existing research on how PRF affects basic physiological processes in vitro. The overall findings suggest that PRF induces cell proliferation, migration, adhesion, and differentiation along with possessing anti-inflammatory properties further supporting its therapeutic potential in wound healing and bone regeneration.

Current Advances in the Synthesis and Biological Evaluation of Pharmacologically Relevant 1,2,4,5-Tetrasubstituted-1H-Imidazole Derivatives

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In recent years, the synthesis and evaluation of the biological properties of 1,2,4,5-tetrasubstituted-1H-imidazole derivatives have been the subject of a large number of studies by academia and industry. In these studies it has been shown that this large and highly differentiated class of heteroarene derivatives includes high valuable compounds having important biological and pharmacological properties such as antibacterial, antifungal, anthelmintic, anti-inflammatory, anticancer, antiviral, antihypertensive, cholesterol-lowering, antifibrotic, antiuricemic, antidiabetic, antileishmanial and antiulcer activities.

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The present review with 411 references, in which we focused on the literature data published mainly from 2011 to 2017, aims to update the readers on the recent developments on the synthesis and biological evaluation of pharmacologically relevant 1,2,4,5-tetrasubstituted-1H-imidazole derivatives with an emphasis on their different molecular targets and their potential use as drugs to treat various types of diseases. Reference was also made to substantial literature data acquired before 2011 in this burgeoning research area.

Hexokinase 2 couples glycolysis with the profibrotic actions of TGF-β

Metabolic dysregulation in fibroblasts is implicated in the profibrotic actions of transforming growth factor-β (TGF-β). Here, we present evidence that hexokinase 2 (HK2) is important for mediating the fibroproliferative activity of TGF-β both in vitro and in vivo. Both Smad-dependent and Smad-independent TGF-β signaling induced HK2 accumulation in murine and human lung fibroblasts through induction of the transcription factor c-Myc. Knockdown of HK2 or pharmacological inhibition of HK2 activity with Lonidamine decreased TGF-β-stimulated fibrogenic processes, including profibrotic gene expression, cell migration, colony formation, and activation of the transcription factors YAP and TAZ, with no apparent effect on cellular viability. Fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) exhibited an increased abundance of HK2. In a mouse model of bleomycin-induced lung fibrosis, Lonidamine reduced the expression of genes encoding profibrotic markers (collagenΙα1, EDA-fibronectin, α smooth muscle actin, and connective tissue growth factor) and stabilized or improved lung function as assessed by measurement of peripheral blood oxygenation. These findings provide evidence of how metabolic dysregulation through HK2 can be integrated within the context of profibrotic TGF-β signaling.

Salacia chinensis L. Stem Extract Exerts Antifibrotic Effects on Human Hepatic Stellate Cells Through the Inhibition of the TGF-β1-Induced SMAD2/3 Signaling Pathway

Salacia chinensis L. (SC) stems have been used as an ingredient in Thai traditional medicine for treating patients with hepatic fibrosis and liver cirrhosis. However, there is no scientific evidence supporting the antifibrotic effects of SC extract. Therefore, this study aimed to determine the antifibrotic activity of SC stem extract in human hepatic stellate cell-line called LX-2. We found that upon TGF-β1 stimulation, LX-2 cells transformed to a myofibroblast-like phenotype with a noticeable increase in α-SMA and collagen type I production. Interestingly, cells treated with SC extract significantly suppressed α-SMA and collagen type I production and reversed the myofibroblast-like characteristics back to normal. Additionally, TGF-β1 also influenced the development of fibrogenesis by upregulation of MMP-2, TIMP-1, and TIMP-2 and related cellular signaling, such as pSmad2/3, pErk1/2, and pJNK. Surprisingly, SC possesses antifibrotic activity through the suppression of TGF-β1-mediated production of collagen type 1, α-SMA, and the phosphorylation status of Smad2/3, Erk1/2, and JNK. Taken together, the present study provides accumulated information demonstrating the antifibrotic effects of SC stem extract and revealing its potential for development for hepatic fibrosis patients.

Transforming growth factor beta induces fibroblasts to express and release the immunomodulatory protein PD-L1 into extracellular vesicles

Transforming growth factor-beta (TGFβ) is an enigmatic protein with various roles in healthy tissue homeostasis/development as well as the development or progression of cancer, wound healing, fibrotic disorders, and immune modulation, to name a few. As TGFβ is causal to various fibroproliferative disorders featuring localized or systemic tissue/organ fibrosis as well as the activated stroma observed in various malignancies, characterizing the pathways and players mediating its action is fundamental. In the current study, we found that TGFβ induces the expression of the immunoinhibitory molecule Programed death-ligand 1 (PD-L1) in human and murine fibroblasts in a Smad2/3- and YAP/TAZ-dependent manner. Furthermore, PD-L1 knockdown decreased the TGFβ-dependent induction of extracellular matrix proteins, including collagen Iα1 (colIα1) and alpha-smooth muscle actin (α-SMA), and cell migration/wound healing. In addition to an endogenous role for PD-L1 in profibrotic TGFβ signaling, TGFβ stimulated-human lung fibroblast-derived PD-L1 into extracellular vesicles (EVs) capable of inhibiting T cell proliferation in response to T cell receptor stimulation and mediating fibroblast cell migration. These findings provide new insights and potential targets for a variety of fibrotic and malignant diseases.

Targeting inflammatory sites through collagen affinity enhances the therapeutic efficacy of anti-inflammatory antibodies

Enhancing the therapeutic efficacy of drugs for inflammatory diseases is of high demand. One possible approach is targeting drugs to the extracellular matrix of the inflamed area. Here, we target collagens in the matrix, which are inaccessible in most tissues yet are exposed to the bloodstream in the inflamed area because of vascular hyperpermeability. We conferred collagen affinity to anti-tumor necrosis factor-α (α-TNF) antibody by conjugating a collagen-binding peptide (CBP) derived from the sequence of decorin. CBP-α-TNF accumulated in the inflamed paw of the arthritis model, and arthritis development was significantly suppressed by treatment with CBP-α-TNF compared with the unmodified antibody. Similarly, CBP-anti-transforming growth factor-β (α-TGF-β) accumulated in the inflamed lung of pulmonary fibrosis model and significantly suppressed pulmonary fibrosis compared with the unmodified antibody. Together, collagen affinity enables the anticytokine antibodies to target arthritis and pulmonary fibrosis accompanied by inflammation, demonstrating a clinically translational approach to treat inflammatory diseases.

Radiation-Induced Skin Fibrosis: Pathogenesis, Current Treatment Options, and Emerging Therapeutics

Radiotherapy (RT) has become an indispensable part of oncologic treatment protocols for a range of malignancies. However, a serious adverse effect of RT is radiodermatitis; almost 95% of patients develop moderate to severe skin reactions following radiation treatment. In the acute setting, these can be erythema, desquamation, ulceration, and pain. Chronically, soft tissue atrophy, alopecia, and stiffness can be noted. Radiodermatitis can delay oncologic treatment protocols and significantly impair quality of life. There is currently a paucity of effective treatment options and prevention strategies for radiodermatitis. Importantly, recent preclinical and clinical studies have suggested that fat grafting may be of therapeutic benefit, reversing detrimental changes to soft tissue following RT. This review outlines the damaging effects of RT on the skin and soft tissue as well as discusses available treatment options for radiodermatitis. Emerging strategies to mitigate detrimental, chronic radiation-induced changes are also presented.

Radiation-Induced Lung Injury (RILI)

Radiation pneumonitis (RP) and radiation fibrosis (RF) are two dose-limiting toxicities of radiotherapy (RT), especially for lung, and esophageal cancer. It occurs in 5-20% of patients and limits the maximum dose that can be delivered, reducing tumor control probability (TCP) and may lead to dyspnea, lung fibrosis, and impaired quality of life. Both physical and biological factors determine the normal tissue complication probability (NTCP) by Radiotherapy. A better understanding of the pathophysiological sequence of radiation-induced lung injury (RILI) and the intrinsic, environmental and treatment-related factors may aid in the prevention, and better management of radiation-induced lung damage. In this review, we summarize our current understanding of the pathological and molecular consequences of lung exposure to ionizing radiation, and pharmaceutical interventions that may be beneficial in the prevention or curtailment of RILI, and therefore enable a more durable therapeutic tumor response.

microRNA-29b knocks down collagen type I production in cultured rainbow trout (Oncorhynchus mykiss) cardiac fibroblasts

Warm acclimation of rainbow trout can cause a decrease in the collagen content of the heart. This ability to remove cardiac collagen is particularly interesting considering that collagen deposition in the mammalian heart, following an injury, is permanent. We hypothesized that collagen removal can be facilitated by microRNA-29b (miR-29b), a highly conserved, small, non-coding RNA, as a reduction in this microRNA has been reported during the development of fibrosis in the mammalian heart. We also used a bioinformatics approach to investigate the binding potential of miR-29b to the seed sequences of vertebrate collagen isoforms. Cultured trout cardiac fibroblasts were transfected with zebrafish mature miR-29b mimic for 7 days with re-transfection occurring after 3 days. Transfection induced a 17.8-fold increase in miR-29b transcript abundance (P<0.05) as well as a 54% decrease in the transcript levels of the col1a3 collagen isoform, compared with non-transfected controls (P<0.05). Western blotting demonstrated that the level of collagen type I protein was 85% lower in cells transfected with miR-29b than in control cells (P<0.05). Finally, bioinformatic analysis suggested that the predicted 3'-UTR of rainbow trout col1a3 has a comparatively higher binding affinity for miR-29b than the 3'-UTR of col1a1 Together, these results suggest that miR-29b is a highly conserved regulator of collagen type I protein in vertebrates and that this microRNA decreases collagen in the trout heart by targeting col1a3.

The Morphopathogenetic Aspects of Intraabdominal Adhesions in Children under One Year of Age

Background and Objectives: The morphopathogenesis of adhesions is a complex process, characterized by the accumulation of an extracellular matrix, inflammation and hypoxia. The regulatory role between morphopathogenic factors in adhesions has not yet been defined. The aim was to investigate the appearance of transforming growth factor beta (TGFβ), basic fibroblast growth factor (FGF-2), fibroblast growth factor receptor 1 (FGFR1), protein gene product 9.5 (PGP 9.5), chromogranin A (CgA), interleukin-1 alpha (IL-1α), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-7 (IL-7), interleukin-8 (IL-8), interleukin-10 (IL-10), tumor necrosis factor alpha (TNFα), matrix metaloproteinase-2 (MMP-2) and matrix metaloproteinase-2 tissue inhibitor (TIMP-2) in intraabdominal adhesions. Materials and Methods: The study material was obtained from 49 patients under one year of age with total or partial bowel obstruction. All factors were detected using immunohistochemistry methods and their relative distribution was evaluated by means of the semiquantitative counting method. Results: Intraabdominal adhesions are characterized by increased TGFβ, FGFR1 and decreased FGF-2, PGP 9.5, IL-1, IL-4, IL-8, TIMP-2 findings. The most significant changes observed were the remodulation of the extracellular matrix, promotion of neoangiogenesis and the maintenance of a prolonged inflammation. Conclusions: The increase in TGFβ, as well as the disbalance between MMP-2 and TIMP-2 proves an increased fibrosis in intraabdominal adhesions. Less detected FGF-2 and more prominent FGR1 findings points out a compensatory receptor stimulation in response to the lacking same factor. The decrease in PGP 9.5 indicate hypoxic injury and proves the stimulation of neoangiogenesis. An unpronounced IL-1 and marked IL-10 finding indicate the local tissue protection reaction, the decrease in IL-4 could be the direct cause of giant cells, but the decrease of IL-8 could confirm a delayed chemotaxis of inflammatory cells.

Wnt, Notch, and TGF-β Pathways Impinge on Hedgehog Signaling Complexity: An Open Window on Cancer

Constitutive activation of the Hedgehog (Hh) signaling pathway is associated with increased risk of developing several malignancies. The biological and pathogenic importance of Hh signaling emphasizes the need to control its action tightly, both physiologically and therapeutically. Evidence of crosstalk between Hh and other signaling pathways is reported in many tumor types. Here, we provide an overview of the current knowledge about the communication between Hh and major signaling pathways, such as Notch, Wnt, and transforming growth factor β (TGF-β), which play critical roles in both embryonic and adult life. When these pathways are unbalanced, impaired crosstalk contributes to disease development. It is reported that more than one of these pathways are active in different type of tumors, at the same time. Therefore, starting from a plethora of stimuli that activate multiple signaling pathways, we describe the signals that preferentially converge on the Hh signaling cascade that influence its activity. Moreover, we highlight several connection points between Hh and Notch, Wnt, or TGF-β pathways, showing a reciprocal synergism that contributes to tumorigenesis, supporting a more malignant behavior by tumor cells, such as in leukemia and brain tumors. Understanding the importance of these molecular interlinking networks will provide a rational basis for combined anticancer drug development.

Melon GliSODin® Prevents Diet-Induced NASH Onset by Reducing Fat Synthesis and Improving Liver Function

A high-calorie diet causes fat accumulation and oxidative stress in the liver, leading to fatty liver and eventually non-alcoholic steatohepatitis (NASH). Melon GliSODin^® is used as a nutritional supplement because of its antioxidant activity. This study aimed to assess the antioxidant activity of Melon GliSODin^® and its effectiveness in preventing NASH, which primarily results from oxidative stress. Furthermore, we verified the protective effect of Melon GliSODin^® by administering it to a mouse model of diet-induced NASH. Melon GliSODin^® suppressed liver fibrosis and fat accumulation, which is characteristic of the NASH phenotype. Gene expression analysis confirmed the suppression of fat synthesis and activation of antioxidative mechanisms. These results show that Melon GliSODin^® mitigates NASH onset at the molecular level, suggesting its potential application as a NASH preventive agent.

Cross-talk between TH2 and TH17 pathways in patients with chronic rhinosinusitis with nasal polyps

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous disease with a spectrum of endotypes. T_H2- and T_H17-related cytokines are 2 central regulators involved in the inflammation associated with CRSwNP.

OBJECTIVE

We sought to investigate the interregulation of T_H2 and T_H17 pathways in Chinese patients with CRSwNP.

METHODS

Levels of key T_H2- and T_H17-related factors were measured in homogenates of polyp tissue obtained from patients with CRSwNP. The relationship of these factors and their expression in groups classified according to tissue IL-5 and IL-17 concentrations were analyzed. Cross-regulation of T_H2 and T_H17 cytokines and the effects of dexamethasone treatment were studied in dispersed nasal polyp cells. Associations between T_H2- and T_H17 related factors and comorbid atopic status and asthma, disease recurrence, and edema scores were also explored.

RESULTS

Four CRSwNP groups were classified based on expression or nonexpression of mutually exclusive T_H2- and T_H17-related factors. The T_H2 cytokines IL-4 and IL-13 inhibited expression of T_H17-related factors, whereas the T_H17 cytokines IL-17 and TGF-β1 enhanced expression of T_H2-related factors. Dexamethasone treatment inhibited both the T_H2 and T_H17 pathways. A patient's atopic status was related to their T_H2 immune response. Edema scores were positively correlated with the T_H2 pathway and negatively correlated with the T_H17 pathway.

CONCLUSION

The T_H2 and T_H17 pathways are mutually exclusive and regulate each other, favoring the development of a T_H2 immune response in Chinese patients with CRSwNP.

Loss of the transcription factor RBPJ induces disease-promoting properties in brain pericytes

Sufficient vascular supply is indispensable for brain development and function, whereas dysfunctional blood vessels are associated with human diseases such as vascular malformations, stroke or neurodegeneration. Pericytes are capillary-associated mesenchymal cells that limit vascular permeability and protect the brain by preserving blood-brain barrier integrity. Loss of pericytes has been linked to neurodegenerative changes in genetically modified mice. Here, we report that postnatal inactivation of the Rbpj gene, encoding the transcription factor RBPJ, leads to alteration of cell identity markers in brain pericytes, increases local TGFβ signalling, and triggers profound changes in endothelial behaviour. These changes, which are not mimicked by pericyte ablation, imperil vascular stability and induce the acquisition of pathological landmarks associated with cerebral cavernous malformations. In adult mice, loss of Rbpj results in bigger stroke lesions upon ischemic insult. We propose that brain pericytes can acquire deleterious properties that actively enhance vascular lesion formation and promote pathogenic processes.

Pericytes are perivascular cells essential for blood-brain barrier maintenance. Here Diéguez-Hurtado et al. show that depletion of the transcription factor RBPJ in pericytes affects their molecular identity and disturbs endothelial cell behaviour, inducing the formation of vascular lesions in the brain.

High-Performance Acellular Tissue Scaffold Combined with Hydrogel Polymers for Regenerative Medicine

Decellularization of tissues provides extracellular matrix (ECM) scaffolds for regeneration therapy and an experimental model to understand ECM and cellular interactions. However, decellularization often causes microstructure disintegration and reduction of physical strength, which greatly limits the use of this technique in soft organs or in applications that require maintenance of physical strength. Here, we present a new tissue decellularization procedure, namely CASPER (Clinically and Experimentally Applicable Acellular Tissue Scaffold Production for Tissue Engineering and Regenerative Medicine), which includes infusion and hydrogel polymerization steps prior to robust chemical decellularization treatments. Polymerized hydrogels serve to prevent excessive damage to the ECM while maintaining the sophisticated structures and biological activities of ECM components in various organs, including soft tissues such as brains and embryos. CASPERized tissues were successfully recellularized to stimulate a tissue-regeneration-like process after implantation without signs of pathological inflammation or fibrosis in vivo, suggesting that CASPERized tissues can be used for monitoring cell-ECM interactions and for surrogate organ transplantation.

N-acetylcysteine prevents bladder tissue fibrosis in a lipopolysaccharide-induced cystitis rat model

Therapeutic options for non-Hunner type interstitial cystitis (IC), which is histologically characterized by fibrosis and mast cell infiltration, are limited. We developed a rat model that replicates chronic inflammation and fibrosis and evaluated the therapeutic effect of N-acetylcysteine (NAC), a well-known anti-fibrotic agent, on the model. Intravesical instillation of lipopolysaccharide (LPS, 750 μg) after protamine sulfate (10 mg) was conducted twice per week for five consecutive weeks. One week after final instillation, 200 mg/kg NAC (n = 10, IC + NAC group) or phosphate-buffered saline (n = 10, IC group) was daily injected intraperitoneally once daily for 5 days. LPS instillation induced bladder fibrosis, mast cell infiltration, and apoptotic tissue damage. Functionally, LPS insult led to irregular micturition, decreased inter-contraction intervals, and decreased micturition volume. NAC significantly improved most of the voiding parameters and reversed histological damages including fibrosis. NAC inhibited the induction and nuclear localization of phospho-Smad2 protein in bladder tissues and the upregulation of genes related to fibrosis, such as Tgfb2, Tgfb3, Smad2, Smad3, Cxcl10, and Card10. This is the first study to demonstrate the beneficial effects on NAC in restoring voiding function, relieving tissue fibrosis and related bladder injuries, in the LPS-induced cystitis rat model.

QiShenYiQi Pills® ameliorates ischemia/reperfusion-induced myocardial fibrosis involving RP S19-mediated TGFβ1/Smads signaling pathway

QiShenYiQi Pills (QSYQ) is a compound Chinese medicine widely used in China for treatment of cardiovascular disease. However, limited data are available regarding the anti-fibrotic role of QSYQ after ischemia/reperfusion (I/R) injury. This study aimed to investigate the effect of post-treatment with QSYQ on myocardial fibrosis after I/R-induced myocardium injury, and the role of different compounds of QSYQ, focusing especially on the involvement of chemokine ribosomal protein S19 (RP S19) dimer and monocyte migration. Male Sprague-Dawley rats were subjected to left anterior descending coronary artery occlusion for 30 min followed by reperfusion with or without administration of QSYQ (0.6, 1.2, or 1.8 g/kg) once daily by gavage for 6 days. Post-treatment with QSYQ diminished I/R-induced infarct size, alleviated myocardium injury, attenuated myocardial fibrosis after 6 days of reperfusion, and restored heart function and myocardial blood flow after I/R. In addition, the drug significantly inhibited monocyte infiltration and macrophage polarization towards M2, which was attributable to chemokine RP S19 dimer. Moreover, Western blots revealed that QSYQ blocked I/R-induced increase in TGFβ1 and TGFβRⅡ and reversed its relevant gene expression, such as Smad3,4,6,7, and inhibited the increase of MMP 2,9 expression. As the major components of QSYQ, astragaloside IV (AsIV), 3,4-dihydroxy-phenyl lactic acid (DLA), and notoginsenoside R1 (R1) were assessed as to the contribution of each of them to the expression of the proteins concerned. The results showed that the effect of AsIV was similar to QSYQ, while DLA and R1 only partly simulated the effect of QSYQ. The results provide evidence for the potential role of QSYQ in treating myocardial fibrosis following I/R injury. This effect may be associated with QSYQ's inhibition effect on monocyte chemotaxis and TGFβ1/Smads signaling pathway with different component targeting distinct link (s) of the signaling.

Chemoirradiated neutrophils and T cells differentially affect immune functions of APCs

Extracorporeal photopheresis (ECP) is known as an immunomodulatory therapy with few side effects, which is mainly used in the treatment of cutaneous T cell lymphoma, graft-versus-host disease, and allograft rejection. During ECP, leukocytes are separated from whole blood by leukapheresis, subsequently chemoirradiated with 8-methoxypsoralen and UVA light, and re-infused into the patient. Although clinically effective, its mode of action has not been fully elucidated. In the present study, we analyzed the interaction of chemoirradiated neutrophils and CD3+ lymphocytes with APC in an in vitro model. We report that chemoirradiated CD3+ T cells induced increased expression of activation markers on dendritic cells (DC), macrophages, and monocytes. Coculture of chemoirradiated CD3+ T cells with these APC also led to significantly increased secretion of TNF-α. Although less pronounced, additional activation of APC took place when APC were stimulated with LPS or IFN-γ. In contrast, chemoirradiated neutrophils did not show activating effects on APC. The presence of chemoirradiated neutrophils during LPS and IFN-γ stimulation of DC rather diminished DC and macrophage activation. In line with these findings DC cocultured with chemoirradiated CD3+ T cells, but not neutrophils, showed significantly increased activation of CD3+ responder lymphocytes in a mixed lymphocyte reaction. With this study, we demonstrate that chemoirradiated leukocytes have differential indirect immunomodulatory effects. Whereas chemoirradiated CD3+ T cells activate APC, chemoirradiated neutrophils suppress activation of APC in the presence of other activating factors, suggesting that the composition of the ECP-treated buffy coat might be of importance for its immunomodulatory effects.

Quality and Quantity-Cultured Murine Endothelial Progenitor Cells Increase Vascularization and Decrease Fibrosis in the Fat Graft

BACKGROUND

Fat grafting has become a valuable technique for soft-tissue reconstruction; however, long-lasting success depends on several determinants. An early blood supply to the transplanted adipocytes is important to prevent ischemia. The recently developed quality and quantity (QQ) culture increases the vasculogenic potential of endothelial progenitor cells. The authors used a murine fat grafting model to address the hypothesis that QQ-cultured endothelial progenitor cells stimulate the establishment of a blood vessel network and increase graft success.

METHODS

c-KitSca-1Lin (KSL) cells were isolated as endothelial progenitor cell precursors from C57BL/6 mice. Adipose tissue was grafted with QQ-cultured KSL cells (QQKSL group), uncultured KSL cells (KSL group), adipose-derived stem cells (ASC group), and a combination (QQKSL+ASC group), and compared to a control group. Five and 10 weeks later, grafts were weighed, histologic and immunohistochemical parameters were evaluated, and gene expression was quantified by quantitative polymerase chain reaction.

RESULTS

The highest vessel density was observed in the combined QQKSL+ASC group (68.0 ± 4.3/mm; p < 0.001) and the QQKSL group (53.9 ± 3.0/mm; p < 0.001). QQKSL cells were engrafted in proximity to the graft vasculature. QQKSL cells decreased the fibrosis percentage (13.8 ± 1.8 percent; p < 0.05). The combined QQKSL+ASC group (22.4 ± 1.8/mm; p < 0.001) showed the fewest local inflammation units. A significant up-regulation of platelet-derived growth factor and adiponectin expression was observed in the QQKSL group and QQKSL+ASC group. Graft weight persistence was not significantly different between groups.

CONCLUSIONS

Supplementing fat grafts with quality and quantity-cultured endothelial progenitor cells improves graft quality by stimulating vascularization. The increased vessel density is associated with less fibrosis, less inflammation, and better adipose tissue integrity. Enriching fat grafts with QQ-cultured endothelial progenitor cells is a potential solution to their clinical shortcomings.

Stroma in normal and cancer wound healing

It is currently believed that stroma, the connective framework of biological tissues, plays a central role in normal wound healing and in cancer. In both these contexts, stromal cellular components such as activated fibroblasts interact with complex protein networks that include growth factors, structural protein or proteinases in order to initiate and sustain an extensive remodelling process. However, although this process is usually spatially and temporally self-limited, it is unregulated in the case of cancer and leads to uncontrolled cell proliferation and invasion within tissues, metastasis and therapeutic resistance. In this review, we outline the role of stroma in normal healing, cancer and post radiotherapy, with a particular focus on the crosstalk between normal or cancer cells and fibroblasts. Understanding these mechanisms is particularly important as several stromal components have been proposed as potential therapeutic targets.

A novel STAT3 inhibitor, STX-0119, attenuates liver fibrosis by inactivating hepatic stellate cells in mice

Liver fibrosis is characterized by formation of scar tissue in the liver. The role of STAT3 signaling has been implicated on activating hepatic stellate cells (HSC) to myofibroblast-like cells in liver fibrosis. Major factors that activate STAT3 signaling are TGF-β1 and IL-6, which are upregulated in the liver in patients afflicted with liver fibrosis. Recent reports indicate that not only IL-6, but also the non-canonical signaling pathway of TGF-β1 is associated with STAT3 signaling. In this study, we demonstrate a new function of the STAT3 inhibitor, STX-0119, in liver fibrosis. STX-0119 is an inhibitor of STAT3 dimerization, which is required for nuclear localization of STAT3. We first investigated the anti-fibrotic effect of STX-0119 in in vitro experiments. Exposure to STX-0119 inhibited the nuclear localization of STAT3 in HSCs, resulting in decreased expression of its target genes, such as col1a1 and αSMA. In addition, STX-0119 also inhibited the TGF-β1/IL-6-induced activation of HSCs. Next, we examined the in vivo effect of STX-0119 in the liver fibrosis mouse model using thioacetamide (TAA) and carbon tetrachloride (CCl₄). STX-0119 attenuated the TAA-induced liver fibrosis by inhibiting activation of HSCs to myofibroblast-like cells. Consistent with the in vivo results using TAA-induced liver fibrosis model, treatment of STX-0119 similarly attenuated CCl₄-induced liver fibrosis. In conclusion, we believe that STX-0119 inhibits the development of liver fibrosis by blocking the activation of hepatic stellate cells. These results indicate that STX-0119 is a potential new therapeutic strategy to prevent disease progression to cirrhosis.

TGFβ-facilitated optic fissure fusion and the role of bone morphogenetic protein antagonism

The optic fissure is a transient gap in the developing vertebrate eye, which must be closed as development proceeds. A persisting optic fissure, coloboma, is a major cause for blindness in children. Although many genes have been linked to coloboma, the process of optic fissure fusion is still little appreciated, especially on a molecular level. We identified a coloboma in mice with a targeted inactivation of transforming growth factor β2 (TGFβ2). Notably, here the optic fissure margins must have touched, however failed to fuse. Transcriptomic analyses indicated an effect on remodelling of the extracellular matrix (ECM) as an underlying mechanism. TGFβ signalling is well known for its effect on ECM remodelling, but it is at the same time often inhibited by bone morphogenetic protein (BMP) signalling. Notably, we also identified two BMP antagonists among the downregulated genes. For further functional analyses we made use of zebrafish, in which we found TGFβ ligands expressed in the developing eye, and the ligand binding receptor in the optic fissure margins where we also found active TGFβ signalling and, notably, also gremlin 2b (grem2b) and follistatin a (fsta), homologues of the regulated BMP antagonists. We hypothesized that TGFβ is locally inducing expression of BMP antagonists within the margins to relieve the inhibition from its regulatory capacity regarding ECM remodelling. We tested our hypothesis and found that induced BMP expression is sufficient to inhibit optic fissure fusion, resulting in coloboma. Our findings can likely be applied also to other fusion processes, especially when TGFβ signalling or BMP antagonism is involved, as in fusion processes during orofacial development.

TGF-β1/p65/MAT2A pathway regulates liver fibrogenesis via intracellular SAM

Background

Hepatic stellate cell (HSC) activation induced by transforming growth factor β1 (TGF-β1) plays a pivotal role in fibrogenesis, while the complex downstream mediators of TGF-β1 in such process are largely unknown.

Methods

We performed pharmacoproteomic profiling of the mice liver tissues from control, carbon tetrachloride (CCl₄)-induced fibrosis and NPLC0393 administrated groups. The target gene MAT2A was overexpressed or knocked down in vivo by tail vein injection of AAV vectors. We examined NF-κB transcriptional activity on MAT2A promoter via luciferase assay. Intracellular SAM contents were analyzed by LC-MS method.

Findings

We found that methionine adenosyltransferase 2A (MAT2A) is significantly upregulated in the CCl₄-induced fibrosis mice, and application of NPLC0393, a known small molecule inhibitor of TGF-β1 signaling pathway, inhibits the upregulation of MAT2A. Mechanistically, TGF-β1 induces phosphorylation of p65, i.e., activation of NF-κB, thereby promoting mRNA transcription and protein expression of MAT2A and reduces S-adenosylmethionine (SAM) concentration in HSCs. Consistently, in vivo and in vitro knockdown of MAT2A alleviates CCl₄- and TGF-β1-induced HSC activation, whereas in vivo overexpression of MAT2A facilitates hepatic fibrosis and abolishes therapeutic effect of NPLC0393.

Interpretation

This study identifies TGF-β1/p65/MAT2A pathway that is involved in the regulation of intracellular SAM concentration and liver fibrogenesis, suggesting that this pathway is a potential therapeutic target for hepatic fibrosis.

Fund

This work was supported by National Natural Science Foundation of China (No. 81500469, 81573873, 81774196 and 31800693), Zhejiang Provincial Natural Science Foundation of China (No. Y15H030004), the National Key Research and Development Program from the Ministry of Science and Technology of China (No. 2017YFC1700200) and the Key Program of National Natural Science Foundation of China (No. 8153000502).

Targeted Drug Delivery to Hepatic Stellate Cells for the Treatment of Liver Fibrosis

Liver fibrosis is caused by excessive accumulation of extracellular matrix during chronic liver injuries. Although clinical evidence suggests that liver fibrosis can be reversed, there is no standard therapy for liver fibrosis. Moreover, there is a lack of diagnostic tools to detect early-stage liver fibrosis. Activation of hepatic stellate cells (HSCs) is the key step during liver fibrogenesis, and its mechanism has been extensively studied by various cell culture and animal models. Targeted delivery of therapeutic agents to activated HSCs is therefore critical for the successful treatment of liver fibrosis. A number of protein markers have been found to be overexpressed in activated HSCs, and their ligands have been used to specifically deliver various antifibrotic agents. In this review, we summarize these HSC-specific protein markers and their ligands for targeted delivery of antifibrotic agents.

Inactivation of platelet-derived TGF-β1 attenuates aortic stenosis progression in a robust murine model

Aortic stenosis (AS) is a degenerative heart condition characterized by fibrosis and narrowing of aortic valves (AV), resulting in high wall shear stress (WSS) across valves. AS is associated with high plasma levels of transforming growth factor-β1 (TGF-β1), which can be activated by WSS to induce organ fibrosis, but the cellular source of TGF-β1 is not clear. Here, we show that platelet-derived TGF-β1 plays an important role in AS progression. We first established an aggressive and robust murine model of AS, using the existing Ldlr -/- Apob100/100 (LDLR) breed of mice, and accelerated AS progression by feeding them a high-fat diet (HFD). We then captured very high resolution images of AV movement and thickness and of blood flow velocity across the AV, using a modified ultrasound imaging technique, which revealed early evidence of AS and distinguished different stages of AS progression. More than 90% of LDLR animals developed AS within 6 months of HFD. Scanning electron microscopy and whole-mount immunostaining imaging of AV identified activated platelets physically attached to valvular endothelial cells (VEC) expressing high phosphorylated Smad2 (p-Smad2). To test the contribution of platelet-derived TGF-β1 in AS, we derived LDLR mice lacking platelet TGF-β1 (TGF-β1platelet-KO-LDLR) and showed reduced AS progression and lower p-Smad2 and myofibroblasts in their AV compared with littermate controls fed the HFD for 6 months. Our data suggest that platelet-derived TGF-β1 triggers AS progression by inducing signaling in VEC, and their subsequent transformation into collagen-producing-myofibroblasts. Thus, inhibiting platelet-derived TGF-β1 might attenuate or prevent fibrotic diseases characterized by platelet activation and high WSS, such as AS.

Bi-directional regulation of TGF-β/Smad pathway by arsenic: A systemic review and meta-analysis of in vivo and in vitro studies

BACKGROUND

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.

OBJECTIVE

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.

RESULTS

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.

CONCLUSION

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.

Dendropanax morbifera Ameliorates Thioacetamide-Induced Hepatic Fibrosis via TGF-β1/Smads Pathways

Hepatic fibrosis, characterized by persistent deposition of extracellular matrix (ECM) proteins, occurs in most types of chronic liver disease. The prevention of liver damage using extract of Dendropanax morbifera has been widely studied, but its molecular mechanism on the therapeutic efficacy of hepatic fibrosis is unclear. The aim of this study was to assess whether aquatic extract (DM) of D. morbifera ameliorates thioacetamide (TAA)-induced hepatic fibrosis. Hepatic fibrosis was induced by an intraperitoneal (i.p.) injection (150 mg/kg, twice per week) of TAA for 6 weeks. DM (50 mg/kg/day) or silymarin (50 mg/kg/day) was administered daily for 6 weeks. DM markedly reduced serum AST, ALT, ALP, and r-GTP in TAA-treated rats. DM significantly ameliorated the total glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT) activity in TAA-treated rats. In particular, DM significantly reduced expression of α-SMA, type I collagen, vimentin, TGF-β1 and p-Smad2/3 in hepatic fibrosis rats. The protective effects of DM on progression of hepatic fibrosis were clearly shown by detecting 4-hydroxyproline concentration and histopathological examination in the liver. Therefore, our data suggest that DM dramatically prevented hepatic fibrosis by inhibiting oxidative stress and the TGF-β1/Smads signaling pathways.

Reprogramming of Energy Metabolism in Response to Radiotherapy in Head and Neck Squamous Cell Carcinoma

Head and neck cancer (HNC) is the sixth cause of cancer-related death worldwide. Head and neck squamous cells carcinoma (HNSCC) is the most frequent subtype of HNC. The development of HNSCC is associated to alcohol consumption, smoking or infection by high-risk human Papillomavirus (HR-HPV). Although the incidence of cancers associated with alcohol and tobacco has diminished, HNSCC associated with HR-HPV has significantly increased in recent years. However, HPV-positive HNSCC responds well to treatment, which includes surgery followed by radiation or chemoradiation therapy. Radiation therapy (RT) is based on ionizing radiation (IR) changing cell physiology. IR can directly interact with deoxyribonucleic acid (DNA) or produce reactive oxygen and nitrogen species (RONS), provoking DNA damage. When DNA damage is not repaired, programmed cell death (apoptosis and/or autophagy) is induced. However, cancer cells can acquire resistance to IR avoiding cell death, where reprogramming of energy metabolism has a critical role and is intimately connected with hypoxia, mitochondrial physiology, oxidative stress (OS) and autophagy. This review is focused on the reprogramming of energy metabolism in response to RT in HPV-positive and HPV-negative HNSCC, showing their differences in cellular metabolism management and the probable direction of treatments for each subtype of HNSCC.

Human Novel MicroRNA Seq-915_x4024 in Keratinocytes Contributes to Skin Regeneration by Suppressing Scar Formation

Early in gestation, wounds in fetal skin heal by regeneration, in which microRNAs play key roles. Seq-915_x4024 is a novel microRNA candidate confirmed by deep sequencing and mirTools 2.0. It is highly expressed in fetal keratinocytes during early gestation. Using an in vitro wound-healing assay, Transwell cell migration assay, and MTS proliferation assay, we demonstrated that keratinocytes overexpressing seq-915_x4024 exhibited higher proliferative activity and the ability to promote fibroblast migration and fibroblast proliferation. These characteristics of keratinocytes are the same biological behaviors as those of fetal keratinocytes, which contribute to skin regeneration. In addition, seq-915_x4024 suppressed the expression of the pro-inflammatory markers TNF-α, IL-6, and IL-8 and the pro-inflammatory chemokines CXCL1 and CXCL5. We also demonstrated that seq-915_x4024 regulates TGF-β isoforms and the extracellular matrix. Moreover, using an in vivo wound-healing model, we demonstrated that overexpression of seq-915_x4024 in keratinocytes suppresses inflammatory cell infiltration and scar formation. Using bioinformatics analyses, luciferase reporter assays, and western blotting, we further demonstrated that Sar1A, Smad2, TNF-α, and IL-8 are direct targets of seq-915_x4024. Furthermore, the expression of phosphorylated Smad2 and Smad3 was reduced by seq-915_x4024. Seq-915_x4024 could be used as an anti-fibrotic factor for the treatment of wound healing.

Effects of dipeptidyl peptidase-4 inhibitors on transforming growth factor-β1 signal transduction pathways in the ovarian fibrosis of polycystic ovary syndrome rats

Aim

Examine the effects of dipeptidyl peptidase‐4 (DPP4) inhibitor Sitagliptin on the transforming growth factor‐β1 (TGF‐β1) signal transduction pathway in polycystic ovary syndrome (PCOS) rats with ovarian fibrosis.

Methods

Thirty rats were divided randomly into the PCOS model group, Sitagliptin treatment group and blank control group. Dehydroepiandrosterone was administered to the model group and treatment group to establish the models. Then, the phenotype of rats was recorded, and the serum sex hormone levels were measured. The pathological structures of the rat ovaries were observed. The protein and mRNA expression levels of DPP4, connective tissue growth factor (CTGF), TGF‐β1 and Smad2/3 in the ovaries were analyzed.

Results

There was no statistically difference in fasting body weight and blood glucose among the three groups before Sitagliptin treatment (P > 0.05). The fasting blood glucose level was significantly decreased after the administration of Sitagliptin (P < 0.05). The level of testosterone in the model group was reduced remarkably after Sitagliptin treatment (P < 0.001). The protein expression levels of DPP4, CTGF and TGF‐β1 in the ovarian stroma were lower in the treatment group than in the model group (P < 0.01, P < 0.001, P < 0.05). The mRNA levels of DPP4, CTGF and TGF‐β1 in the model group also greatly declined after Sitagliptin treatment (P < 0.05, P < 0.001, P < 0.01).

Conclusion

The DPP4 inhibitor Sitagliptin lowers fasting blood glucose, relieves the high androgen state of PCOS rats and delays the process of ovarian fibrosis, which may be related to reducing the levels of factors related to the TGF‐β1/Smad2/3 signaling pathway.