Hepatocyte growth factor regulates the TGF-β1-induced proliferation, differentiation and secretory function of cardiac fibroblasts

Action of Platelet-Rich Plasma on In Vitro Cellular Bioactivity: More than Platelets

Platelet-rich plasma (PRP) is a biological therapy in which one of the mechanisms of action is the stimulation of biological processes such as cell proliferation. The size of PRP’s effect depends on multiple factors, one of the most important being the composition of PRP. The aim of this study was to analyze the relationship between cell proliferation and the levels of certain growth factors (IGF-1, HGF, PDGF, TGF-β and VEG) in PRP. First, the composition and effect on cell proliferation of PRP versus platelet-poor plasma (PPP) were compared. Subsequently, the correlation between each growth factor of PRP and cell proliferation was evaluated. Cell proliferation was higher in cells incubated with lysates derived from PRP compared to those cultured with lysates derived from PPP. In terms of composition, the levels of PDGF, TGF-β, and VEGF were significantly higher in PRP. When analyzing the PRP growth factors, IGF-1 was the only factor that correlated significantly with cell proliferation. Of those analyzed, the level of IGF-1 was the only one that did not correlate with platelet levels. The magnitude of PRP’s effect depends not only on platelet count but also on other platelet-independent molecules.

Microparticles Decorated with Cell-Instructive Surface Chemistries Actively Promote Wound Healing

Wound healing is a complex biological process involving close crosstalk between various cell types. Dysregulation in any of these processes, such as in diabetic wounds, results in chronic nonhealing wounds. Fibroblasts are a critical cell type involved in the formation of granulation tissue, essential for effective wound healing. 315 different polymer surfaces are screened to identify candidates which actively drive fibroblasts toward either pro- or antiproliferative functional phenotypes. Fibroblast-instructive chemistries are identified, which are synthesized into surfactants to fabricate easy to administer microparticles for direct application to diabetic wounds. The pro-proliferative microfluidic derived particles are able to successfully promote neovascularization, granulation tissue formation, and wound closure after a single application to the wound bed. These active novel bio-instructive microparticles show great potential as a route to reducing the burden of chronic wounds.

Combined role for YAP-TEAD and YAP-RUNX2 signalling in substrate-stiffness regulation of cardiac fibroblast proliferation

Cardiac fibrosis is associated with increased stiffness of the myocardial extracellular matrix (ECM) in part mediated by increased cardiac fibroblast proliferation However, our understanding of the mechanisms regulating cardiac fibroblast proliferation are incomplete. Here we characterise a novel mechanism involving a combined activation of Yes-associated protein (YAP) targets RUNX Family Transcription Factor 2 (RUNX2) and TEA Domain Transcription Factor (TEAD). We demonstrate that cardiac fibroblast proliferation is enhanced by interaction with a stiff ECM compared to a soft ECM. This is associated with activation of the transcriptional co-factor, YAP. We demonstrate that this stiffness induced activation of YAP enhances the transcriptional activity of both TEAD and RUNX2 transcription factors. Inhibition of either TEAD or RUNX2, using gene silencing, expression of dominant-negative mutants or pharmacological inhibition, reduces cardiac fibroblast proliferation. Using mutants of YAP, defective in TEAD or RUNX2 activation ability, we demonstrate a dual role of YAP-mediated activation of TEAD and RUNX2 for substrate stiffness induced cardiac fibroblast proliferation. Our data highlights a previously unrecognised role of YAP mediated RUNX2 activation for cardiac fibroblast proliferation in response to increased ECM stiffness.

Circulating Hepatocyte Growth Factor Reflects Activation of Vascular Repair in Response to Stress

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HGF is released by stressed human vascular cells and promotes vascular cell repair responses in autocrine and/or paracrine ways.

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Subjects with a low capacity to express HGF in response to systemic stress have an increased cardiovascular risk.

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Human atherosclerotic plaques with a low content of HGF have a more unstable phenotype.

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The present study shows that subjects with a low ability to express HGF in response to metabolic stress have an increased risk to suffer cardiovascular events.

Hepatocyte growth factor (HGF) is released by stressed human vascular cells and promotes vascular cell repair responses in both autocrine and paracrine ways. Subjects with a low capacity to express HGF in response to systemic stress have an increased cardiovascular risk. Human atherosclerotic plaques with a low content of HGF have a more unstable phenotype. The present study shows that subjects with a low ability to express HGF in response to metabolic stress have an increased risk to suffer myocardial infarction and stroke.

Targeted deletion of TGFβ1 in basal keratinocytes causes profound defects in stratified squamous epithelia and aberrant melanocyte migration

Transforming Growth Factor Beta 1 (TGFβ1) is a multifunctional cytokine that regulates proliferation, apoptosis, and epithelial-mesenchymal transition of epithelial cells. While its role in cancer is well studied, less is known about TGFβ1 and regulation of epithelial development. To address this, we deleted TGFβ1 in basal keratinocytes of stratified squamous epithelia. Newborn mice with a homozygous TGFβ1 deletion had significant defects in proliferation and differentiation of the epidermis and oral mucosa, and died shortly after birth. Hair follicles were sparse in TGFβ1 depleted skin and had delayed development. Additionally, the Wnt pathway transcription factor LEF1 was reduced in hair follicle bulbs and nearly absent from the basal epithelial layer. Hemizygous knockout mice survived to adulthood but were runted and had sparse coats. The skin of these mice had irregular hair follicle morphology and aberrant hair cycle progression, as well as abnormally high melanin expression and delayed melanocyte migration. In contrast to newborn TGFβ1 null mice, the epidermis was hyperproliferative, acanthotic and inflamed. Expression of p63, a master regulator of stratified epithelial identity, proliferation and differentiation, was reduced in TGFβ1 null newborn epidermis but expanded in the postnatal acanthotic epidermis of TGFβ1 hemizygous mice. Thus, TGFβ1 is both essential and haploinsufficient with context dependent roles in stratified squamous epithelial development and homeostasis.

Transforming growth factor-β in myocardial disease

Transforming growth factor-β (TGFβ) isoforms are upregulated and activated in myocardial diseases and have an important role in cardiac repair and remodelling, regulating the phenotype and function of cardiomyocytes, fibroblasts, immune cells and vascular cells. Cardiac injury triggers the generation of bioactive TGFβ from latent stores, through mechanisms involving proteases, integrins and specialized extracellular matrix (ECM) proteins. Activated TGFβ signals through the SMAD intracellular effectors or through non-SMAD cascades. In the infarcted heart, the anti-inflammatory and fibroblast-activating actions of TGFβ have an important role in repair; however, excessive or prolonged TGFβ signalling accentuates adverse remodelling, contributing to cardiac dysfunction. Cardiac pressure overload also activates TGFβ cascades, which initially can have a protective role, promoting an ECM-preserving phenotype in fibroblasts and preventing the generation of injurious, pro-inflammatory ECM fragments. However, prolonged and overactive TGFβ signalling in pressure-overloaded cardiomyocytes and fibroblasts can promote cardiac fibrosis and dysfunction. In the atria, TGFβ-mediated fibrosis can contribute to the pathogenic substrate for atrial fibrillation. Overactive or dysregulated TGFβ responses have also been implicated in cardiac ageing and in the pathogenesis of diabetic, genetic and inflammatory cardiomyopathies. This Review summarizes the current evidence on the role of TGFβ signalling in myocardial diseases, focusing on cellular targets and molecular mechanisms, and discussing challenges and opportunities for therapeutic translation.

Hopes and Hurdles of Employing Mesenchymal Stromal Cells in the Treatment of Cardiac Fibrosis

Excessive cardiac fibrosis plays a crucial role in almost all types of heart disease. Generally, cardiac fibrosis is a scarring process triggered in response to stress, injury, or aging and is characterized by the accumulation of activated myofibroblasts that deposit high levels of extracellular matrix proteins in the myocardium. While it is beneficial for cardiac repair in the short term, it can also result in pathological remodeling, tissue stiffening, and cardiac dysfunction, contributing to the progression of heart failure, arrhythmia, and sudden cardiac death. Despite its high prevalence, there is a lack of effective and safe therapies that specifically target myofibroblasts to inhibit or even reverse pathological cardiac fibrosis. In the past few decades, cell therapy has been under continuous evaluation as a potential treatment strategy, and several studies have shown that transplantation of mesenchymal stromal cells (MSCs) can reduce cardiac fibrosis and improve heart function. Mechanistically, it is believed that the heart benefits from MSC therapy by stimulating innate anti-fibrotic and regenerative reactions. The mechanisms of action include paracrine signaling and cell-to-cell interactions. In this review, we provide an overview of the anti-fibrotic properties of MSCs and approaches to enhance them and discuss future directions of MSCs for the treatment of cardiac fibrosis.

Pharmacology active microcarriers delivering HGF associated with extracellular vesicles for myocardial repair

Despite the curative approaches developed against myocardial infarction, cardiac cell death causes dysfunctional heart contractions that depend on the extent of the ischemic area and the reperfusion period. Cardiac regeneration may allow neovascularization and limit the ventricular remodeling caused by the scar tissue. We have previously found that large extracellular vesicles, carrying Sonic Hedgehog (lEVs), displayed proangiogenic and antioxidant properties, and decreased myocardial infarction size when administrated by intravenous injection. We propose to associate lEVs with pharmacology active microcarriers (PAMs) to obtain a combined cardioprotective and regenerative action when administrated by intracardiac injection. PAMs made of poly-D,L-lactic-coglycolic acid-poloxamer 188-poly-D,L-lactic-coglycolic acid and covered by fibronectin/poly-D-lysine provided a biodegradable and biocompatible 3D biomimetic support for the lEVs. When compared with lEVs alone, lEVs-PAMs constructs possessed an enhanced in vitro pro-angiogenic ability. PAMs were designed to continuously release encapsulated hepatocyte growth factor (PAMs_HGF) and thus, locally increase the activity of the lEVs by the combined anti-fibrotic properties and regenerative properties. Intracardiac administration of either lEVs alone or lEVs-PAMs_HGF improved cardiac function in a similar manner, in a rat model of ischemia-reperfusion. Moreover, lEVs alone or the IEVs-PAMs_HGF induced arteriogenesis, but only the latter reduced tissue fibrosis. Taken together, these results highlight a promising approach for lEVs-PAMs_HGF in regenerative medicine for myocardial infarction.

Potential Mechanisms of the Impact of Hepatocyte Growth Factor Gene-Modified Tendon Stem Cells on Tendon Healing

The therapeutic impact of stem cells is potentially largely attributable to secretion of exosomes and soluble factors. The present study evaluates the impact of hepatocyte growth factor (HGF)-expressing tendon stem cells (TSCs) on tendon healing in a rat model. Patellar tendon TSCs were isolated and underwent transfection with lentiviral vectors containing HGF or green fluorescent protein (GFP) genes. In vivo, immunohistochemistry of tendons sampled 1 week postsurgery demonstrated that all stem cell-treated groups exhibited higher numbers of CD163⁺ M2 monocytes and IL-10⁺ cells (anti-inflammatory), and lower numbers of CCR7⁺ M1 monocytes and IL-6⁺ as well as COX-2⁺ cells (pro-inflammatory). Effects were most pronounced in the HGF-expressing TSCs (TSCs + HGF) treated group. Histology ± immunohistochemistry of tendons sampled 4 and 8 weeks postsurgery demonstrated that all stem cell-treated groups exhibited more ordered collagen fiber arrangement and lower levels of COLIII, α-SMA, TGF-β1, and fibronectin (proteins relevant to fibroscarring). Effects were most pronounced in the TSCs + HGF-treated group. For the in vitro study, isolated tendon fibroblasts pretreated with TGF-β1 to mimic the in vivo microenvironment of tendon injury were indirectly cocultured with TSCs, TSCs + GFP, or TSCs + HGF using a transwell system. Western blotting demonstrated that all stem cell types decreased TGF-β1-induced increases in fibroblast levels of COX-2, COLIII, and α-SMA, concomitant with decreased activation of major TGF-β1 signaling pathways (p38 MAPK, ERK1/2, but not Smad2/3). This effect was most pronounced for TSCs + HGF, which also decreased the TGF-β1-induced increase in activation of the Smad2/3 signaling pathway. The presence of specific inhibitors of these pathways during fibroblast TGF-β1 stimulation also attenuated increases in levels of COX-2, COLIII, and α-SMA. In conclusion, TSCs + HGF, which exhibit HGF overexpression, may promoting tendon healing via decreasing inflammation and fibrosis, perhaps partly via inhibiting TGF-β1-induced signaling. These findings identify a novel potential therapeutic strategy for tendon injuries, warranting additional research.

A novel role of kallikrein-related peptidase 8 in the pathogenesis of diabetic cardiac fibrosis

Rationale: Among all the diabetic complications, diabetic cardiomyopathy, which is characterized by myocyte loss and myocardial fibrosis, is the leading cause of mortality and morbidity in diabetic patients. Tissue kallikrein-related peptidases (KLKs) are secreted serine proteases, that have distinct and overlapping roles in the pathogenesis of cardiovascular diseases. However, whether KLKs are involved in the development of diabetic cardiomyopathy remains unknown.The present study aimed to determine the role of a specific KLK in the initiation of endothelial-to-mesenchymal transition (EndMT) during the pathogenesis of diabetic cardiomyopathy.

Methods and Results-By screening gene expression profiles of KLKs, it was found that KLK8 was highly induced in the myocardium of mice with streptozotocin-induced diabetes. KLK8 deficiency attenuated diabetic cardiac fibrosis, and rescued the impaired cardiac function in diabetic mice. Small interfering RNA (siRNA)-mediated KLK8 knockdown significantly attenuated high glucose-induced endothelial damage and EndMT in human coronary artery endothelial cells (HCAECs). Diabetes-induced endothelial injury and cardiac EndMT were significantly alleviated in KLK8-deficient mice. In addition, transgenic overexpression of KLK8 led to interstitial and perivascular cardiac fibrosis, endothelial injury and EndMT in the heart. Adenovirus-mediated overexpression of KLK8 (Ad-KLK8) resulted in increases in endothelial cell damage, permeability and transforming growth factor (TGF)-β1 release in HCAECs. KLK8 overexpression also induced EndMT in HCAECs, which was alleviated by a TGF-β1-neutralizing antibody. A specificity protein-1 (Sp-1) consensus site was identified in the human KLK8 promoter and was found to mediate the high glucose-induced KLK8 expression. Mechanistically, it was identified that the vascular endothelial (VE)-cadherin/plakoglobin complex may associate with KLK8 in HCAECs. KLK8 cleaved the VE-cadherin extracellular domain, thus promoting plakoglobin nuclear translocation. Plakoglobin was required for KLK8-induced EndMT by cooperating with p53. KLK8 overexpression led to plakoglobin-dependent association of p53 with hypoxia inducible factor (HIF)-1α, which further enhanced the transactivation effect of HIF-1α on the TGF-β1 promoter. KLK8 also induced the binding of p53 with Smad3, subsequently promoting pro-EndMT reprogramming via the TGF-β1/Smad signaling pathway in HCAECs. The in vitro and in vivo findings further demonstrated that high glucose may promote plakoglobin-dependent cooperation of p53 with HIF-1α and Smad3, subsequently increasing the expression of TGF-β1 and the pro-EndMT target genes of the TGF-β1/Smad signaling pathway in a KLK8-dependent manner.

Conclusions: The present findings uncovered a novel pro-EndMT mechanism during the pathogenesis of diabetic cardiac fibrosis via the upregulation of KLK8, and may contribute to the development of future KLK8-based therapeutic strategies for diabetic cardiomyopathy.

Transforming growth factor-β1 promotes fibrosis but attenuates calcification of valvular tissue applied as a three-dimensional calcific aortic valve disease model

Calcific aortic valve disease (CAVD) is characterized by valvular fibrosis and calcification and driven by differentiating valvular interstitial cells (VICs). Expression data from patient biopsies suggest that transforming growth factor (TGF)-β1 is implicated in CAVD pathogenesis. However, CAVD models using isolated VICs failed to deliver clear evidence on the role of TGF-β1. Thus, employing cultures of aortic valve leaflets, we investigated effects of TGF-β1 in a tissue-based three-dimensional (3-D) CAVD model. We found that TGF-β1 induced phosphorylation of Mothers against decapentaplegic homolog (SMAD) 3 and expression of SMAD7, indicating effective downstream signal transduction in valvular tissue. Thus, TGF-β1 increased VIC contents of rough endoplasmic reticulum, Golgi, and secretory vesicles as well as tissue levels of RNA and protein. In addition, TGF-β1 raised expression of proliferation marker cyclin D1, attenuated VIC apoptosis, and upregulated VIC density. Moreover, TGF-β1 intensified myofibroblastic VIC differentiation as evidenced by increased α-smooth muscle actin and collagen type I along with diminished vimentin expression. In contrast, TGF-β1 attenuated phosphorylation of SMAD1/5/8 and upregulation of β-catenin while inhibiting osteoblastic VIC differentiation as revealed by downregulation of osteocalcin expression, alkaline phosphatase activity, and extracellular matrix incorporation of hydroxyapatite. Collectively, these effects resulted in blocking of valvular tissue calcification and associated disintegration of collagen fibers. Instead, TGF-β1 induced development of fibrosis. Overall, in a tissue-based 3-D CAVD model, TGF-β1 intensifies expressional and proliferative activation along with myofibroblastic differentiation of VICs, thus triggering dominant fibrosis. Simultaneously, by inhibiting SMAD1/5/8 activation and canonical Wnt/β-catenin signaling, TGF-β1 attenuates osteoblastic VIC differentiation, thus blocking valvular tissue calcification. These findings question a general phase-independent CAVD-promoting role of TGF-β1.NEW & NOTEWORTHY Employing aortic valve leaflets as a tissue-based three-dimensional disease model, our study investigates the role of transforming growth factor (TGF)-β1 in calcific aortic valve disease pathogenesis. We find that, by activating Mothers against decapentaplegic homolog 3, TGF-β1 intensifies expressional and proliferative activation along with myofibroblastic differentiation of valvular interstitial cells, thus triggering dominant fibrosis. Simultaneously, by inhibiting activation of Mothers against decapentaplegic homolog 1/5/8 and canonical Wnt/β-catenin signaling, TGF-β1 attenuates apoptosis and osteoblastic differentiation of valvular interstitial cells, thus blocking valvular tissue calcification. These findings question a general phase-independent calcific aortic valve disease-promoting role of TGF-β1.

Unique patterns of cardiogenic and fibrotic gene expression in rat cardiac fibroblasts

BACKGROUND AND AIM

Cardiac fibroblasts are important for both normal and pathological states of the heart, but the knowledge in cell physiology and genomics is still poorly understood. The aims of the present study were; first, to investigate the expression of cardiac and fibrotic genes in rat cardiac fibroblasts compared to cardiomyocytes and other fibroblasts (skin and muscle fibroblasts), second, to examine the in vitro effect of serum concentration on fibroblast gene expression. The findings can potentially be applied in ischemia/reperfusion models.

MATERIALS AND METHODS

Rat cardiac fibroblasts were collected and cultured in different conditions, and their gene expression (21 cardiogenic genes and 16 fibrotic genes) was compared with cardiomyocytes and other fibroblasts using comparative quantitative polymerase chain reaction. We also mimicked myocardial ischemia/reperfusion by depleting and then adding a serum into the culture in conventional culture (10% serum).

RESULTS

Cardiac fibroblasts expressed most of the cardiogenic genes, but their expression levels were significantly lower than in cardiomyocytes, while almost all fibrotic genes in the cardiac fibroblasts were significantly more highly expressed than in cardiomyocytes, except matrix metallopeptidase 9 (Mmp9) which also had greater expression in other fibroblasts. After mimicking cardiac ischemia and reperfusion in vitro by starving and then adding a serum into the cardiac fibroblast culture, the results revealed that Mmp9 expression was significantly increased (>30 times) after increasing but not reducing the serum in the culture. The expression of most cardiogenic and fibrotic genes in cardiac fibroblasts tended to decrease after increasing the serum in the culture. These changes were specific to cardiac fibroblasts but no other fibroblasts.

CONCLUSION

Cardiac fibroblasts have a distinct pattern of gene expression from other fibroblasts and cardiomyocytes. They are also sensitive to high serum concentration but not affected by serum depletion, suggesting that the process of developing cardiac fibrosis might be stimulated by reperfusion or overcirculation rather than ischemia. The cell starvation followed the adding of serum may serve as a useful model to study cardiac fibrosis cause by the change of blood flow.

A Systematic Review on Cornea Epithelial-Stromal Homeostasis

INTRODUCTION

This review aims to summarise the role of different cells, genes, proteins and lipid in regulating cornea epithelial-stromal homeostasis.

METHODS

We performed an Entrez PubMed literature search using keywords "human," "cornea," "epithelial," "stromal," "homeostasis," "fibrosis response," and "pathogenesis" on 24th of September 2019, resulting in 35 papers, of which 18 were chosen after filtering for "English language" and "published within 10 years" as well as curation for relevance by the authors.

RESULTS

The 18 selected papers showed that corneal epithelial cells, fibroblasts and telocytes, together with genes such as Klf4, Pax6 and Id found in the cells, play important roles in achieving homeostasis to maintain corneal integrity and transparency. Proteins classified as pro-fibrotic ligands and anti-fibrotic ligands are responsible for regulating cornea stromal fibrosis and extracellular matrix deposition, thus regulators of scar formation during wound healing. Anti-inflammatory ligands and wound repairing ligands are critical in eliciting protective inflammation and promoting epithelial healing, respectively. Protein receptors located on cellular membrane play a role in maintaining intercellular connections as well as corneal hydration.

DISCUSSION/CONCLUSION

These studies prompt development of novel therapeutic strategies such as tear drops or ointments that target certain proteins to maintain corneal homeostasis. However, more in vitro and in vivo studies are required to prove the effectiveness of exogenous administration of molecules in improving healing outcome. Hence, future investigations of the molecular pathways highlighted in this review will reveal novel therapeutic tools such as gene or cell therapy to treat corneal diseases.

Atorvastatin attenuates TGF‑β1‑induced fibrogenesis by inhibiting Smad3 and MAPK signaling in human ventricular fibroblasts

Excessive proliferation and myofibroblasts transformation of cardiac fibroblasts play a critical role in the process of cardiac fibrosis. Atorvastatin (ATV), a 3‑hydroxy‑3‑methyl‑glutaryl‑coenzyme A reductase inhibitor, is commonly used to treat hypercholesterolemia. It has previously been shown that ATV has potential anti‑fibrotic effects. However, the underlying mechanisms of ATV against cardiac fibrosis remain to be fully elucidated, and to the best of our knowledge, there are no reports focusing on the effects of ATV on transforming growth factor‑β1 (TGF‑β1)‑induced human ventricular fibroblasts (hVFs) activation. In the present study, hVFs were stimulated with TGF‑β1 with or without pretreatment with ATV. Subsequently, hVF proliferation, cytotoxicity, myofibroblast differentiation and pro‑fibrotic gene expression were assessed. Canonical and non‑canonical signaling downstream of TGF‑β1, such as Smad3 and mitogen‑activated protein kinase (MAPK) signaling, were investigated by evaluating the phosphorylation levels of Smad3, extracellular signal‑regulated kinase 1/2, p38 MAPK and c‑Jun N‑terminal kinase. The results indicated that ATV significantly prevented TGF‑β1‑induced cell proliferation, myofibroblast differentiation and production of extracellular matrix proteins, such as matrix metalloproteinase‑2, collagen I and collagen III, in hVFs. Furthermore, ATV effectively inhibited TGF‑β1‑induced activation of Smad3 and MAPK signaling in hVFs. In conclusion, the present results demonstrated that ATV prevented TGF‑β1‑induced fibrogenesis in hVFs, at least in part by inhibiting the Smad3 and MAPK signaling pathways. Therefore, these results imply that ATV may be a promising agent to treat myocardial fibrosis.

Odontogenic infection by Porphyromonas gingivalis exacerbates fibrosis in NASH via hepatic stellate cell activation

Odontogenic infection of Porphyromonas gingivalis (P.g.), a major periodontal pathogen, exacerbates pathological progression of non-alcoholic steatohepatitis (NASH). In this study, we aimed to clarify the detailed mechanism in which P.g. induced hepatic stellate cells (HSCs; key effector cells in liver fibrosis) activation. In the liver of high fat diet-induced NASH mouse model with P.g. odontogenic infection, immunolocalization of P.g. was detected. The number of hepatic crown-like structure, which was macrophage aggregation and related to liver fibrosis, was drastically increased and fibrosis area was also increased through upregulating immunoexpression of Phosphorylated Smad2 (key signaling molecule of TGF-β1) and Galectin-3. P.g.-secreted trypsin-like enzyme [gingipain; an activator of protease-activated receptor 2 (PAR2)] stimulated HSC proliferation and differentiation through Smad and ERK signaling induced by TGF-β1 produced from HSCs with P.g.-infection. Further, Galectin-3 produced from HSCs with P.g. infection and P.g.-derived LPS/lipoprotein stimulation stabilized TGFβ-receptor II resulting in increasing sensitivity for TGF-β1, finally leading to HSC differentiation via activating Smad and ERK signaling. In addition to them, hepatocytes (main component cells of liver) contributed to HSC activation through TGF-β1 and Galectin-3 production in paracrine manner. Collectively, P.g.-odontogenic infection exacerbates fibrosis of NASH by HSC activation through TGF-β1 and Gal-3 production from HSCs and hepatocytes.

Comprehensive circRNA expression profile and construction of circRNA-related ceRNA network in cardiac fibrosis

Cardiac fibrosis is a common pathological condition that contributes to the progression of many cardiac diseases. Circular RNAs (circRNAs) are emerging as new regulators of cardiac fibrosis. However, the expression and function of circRNAs in cardiac fibrosis remain largely unknown. The present study aims to investigate the circRNA expression profile and identify the roles of circRNAs in cardiac fibrosis. Transforming growth factor-β1 (TGF-β1) was used to establish an in vitro model of cardiac fibrosis in cardiac fibroblasts. CircRNA sequencing revealed that a total of 283 circRNAs were aberrantly expressed in fibrotic cardiac fibroblasts, with 79 upregulated and 204 downregulated. The expression changes of randomly selected circRNAs were validated by real-time PCR. A circRNA-based competing endogenous RNA network 1755 nodes and 30394 edges was established, and module analysis was conducted using the plug-in MCODE. KEGG pathway enrichment analysis was performed for mRNAs involved in the top three enriched modules. The results showed that these mRNAs were enriched in cardiac fibrosis-related signalling pathways, including the 'TGF-beta signaling pathway', 'MAPK signaling pathway', 'AMPK signaling pathway', and 'PI3K-Akt signaling pathway'. The predicted ceRNAs and bioinformatics analysis revealed the potential role of circRNAs in cardiac fibrosis, which would provide useful information for understanding the mechanism and finding effective prevention and treatment targets for cardiac fibrosis.

Hypoxia and transforming growth factor β1 regulation of long non-coding RNA transcriptomes in human pulmonary fibroblasts

One of the key characteristics of idiopathic pulmonary fibrosis (IPF) is accumulation of excess fibrous tissue in the lung, which leads to hypoxic conditions. Transforming growth factor (TGF) β is a major mediator that promotes the differentiation of fibroblasts to myofibroblasts. However, how hypoxia and TGFβ together contribute the pathogenesis of IPF is poorly understood. Long non-coding RNAs (lncRNAs) have regulatory effects on certain genes and are involved in many diseases. In this study, we determined the effects of hypoxia and/or TGFβ on mRNA and lncRNA transcriptomes in pulmonary fibroblasts. Hypoxia and TGFβ1 synergistically increased myofibroblast marker expression. RNA sequencing revealed that hypoxia and TGFβ1 treatment resulted in significant changes in 669 lncRNAs and 2,676 mRNAs compared to 150 lncRNAs and 858 mRNAs in TGFβ1 alone group and 222 lncRNAs and 785 mRNAs in hypoxia alone group. TGFβ1 induced the protein expression of HIF-1α, but not HIF-2α. On the other hand, hypoxia enhanced the TGFβ1-induced phosphorylation of Smad3, suggesting a cross-talk between these two signaling pathways. In all, 10 selected lncRNAs (five-up and five-down) in RNA sequencing data were validated using real-time PCR. Two lncRNAs were primarily located in cytoplasm, three in nuclei and five in both nuclei and cytoplasm. The silencing of HIF-1α and Smad3, but not Smad2 and HIF-2α rescued the downregulation of FENDRR by hypoxia and TGFβ1. In conclusion, hypoxia and TGFβ1 synergistically regulate mRNAs and lncRNAs involved in several cellular processes, which may contribute to the pathogenesis of IPF.

Useful applications of growth factors for cardiovascular regenerative medicine

Novel advances for cardiovascular diseases (CVDs) include regenerative approaches for fibrosis, hypertrophy, and neoangiogenesis. Studies indicate that growth factor (GF) signaling could promote heart repair since most of the evidence is derived from preclinical models. Observational studies have evaluated GF serum/plasma levels as feasible biomarkers for risk stratification of CVDs. Noteworthy, two clinical interventional published studies showed that the administration of growth factors (GFs) induced beneficial effect on left ventricular ejection fraction (LVEF), myocardial perfusion, end-systolic volume index (ESVI). To date, large scale ongoing studies are in Phase I-II and mostly focussed on intramyocardial (IM), intracoronary (IC) or intravenous (IV) administration of vascular endothelial growth factor (VEGF) and fibroblast growth factor-23 (FGF-23) which result in the most investigated GFs in the last 10 years. Future data of ongoing randomized controlled studies will be crucial in understanding whether GF-based protocols could be in a concrete way effective in the clinical setting.

Tissue-specific transcriptional regulation of epithelial/endothelial and mesenchymal markers during renovascular hypertension

Epithelial-to-mesenchymal transition (EMT) and endothelial-to-mesenchymal transition are processes that can occur under different biological conditions, including tissue healing due to hypertension and oxidative stress. The purpose of the present study was to evaluate the differences in gene expression of epithelial/endothelial and mesenchymal markers in different tissues. A two-kidney, one-clip (2K1C) renovascular hypertension rat model was used. Hypertension was induced by the clipping of the left renal artery; the rats were randomized into sham and 2K1C groups and monitored for up to 4 weeks. The gene expressions of E-cadherin (E-cad), N-cadherin (N-cad), α-smooth muscle actin (α-SMA), collagen I (COL1A1), collagen III (COL3A1) and hepatocyte growth factor (HGF) were determined by reverse transcription-PCR. The levels of the cytokines transforming growth factor-β1, tumor necrosis factor-α, interleukin (IL)-4, IL-6 and IL-10 were evaluated using ELISAs. The levels of thiobarbituric acid reactive substances and thiol groups were measured to evaluate oxidative stress. All analyses were performed on the liver, heart and kidneys tissues of sham and model rats. The 2K1C animals exhibited a higher systolic blood pressure, as well as cardiac hypertrophy and atrophy of the left kidney. Fibrotic alterations in the heart and kidneys were observed, as was an increase in the collagen fiber areas, and higher levels of inflammatory cytokines, which are associated with the increased expression of fibroproliferative and anti-fibrotic genes. Renovascular hypertension regulated epithelial/endothelial and mesenchymal markers, including E-cad, N-cad, α-SMA and COL1A1 in the kidneys and heart. EMT in the kidneys was mediated by an increased level of inflammatory and profibrotic cytokines, as well as by oxidative stress. The data in the present study suggested that the expression of epithelial/endothelial and mesenchymal markers are differentially regulated by hypertension in the liver, heart and kidneys.

Role of calcium channels and endothelial factors in nickel induced aortic hypercontraction in Wistar rats

Aim: To investigate the mechanism of nickel augmented phenylephrine (PE)-induced contraction in isolated segments of Wistar rat aorta. Materials and Methods: Effect of varying concentrations of nickel on PE-induced contraction were investigated in isolated segments of Wistar rat aorta using an organ bath system. Aortic rings were pre-incubated with verapamil (1 µM and 20 µM), gadolinium, apocynin, indomethacin or N-G-nitro-L-arginine methyl ester (L-NAME) separately before incubation with nickel. Results: Endothelium intact aortic rings incubated with 100 nM, 1 µM or 100 µM of nickel exhibited 80%, 43% and 28% increase in PE-induced contraction, respectively, while no such enhancing responses were observed in endothelium denuded aorta. Incubation of aortic rings with 1 µM and 20 µM verapamil suggested an involvement of influx of calcium through T-type calcium channels in smooth muscle cells, while aortic rings pre-incubated with gadolinium showed no role of store operated calcium channels in the nickel effect on PE-induced contractions. The enhancing effect of nickel on PE-induced contractions was inhibited by apocynin, indomethacin or L-NAME. Conclusion: Nickel has caused augmentation of PE-induced contractions as a result of the endothelial generation of reactive oxygen species (ROS) and cyclooxygenase 2 (COX2) dependent endothelium contracting factors (EDCFs), which increases the influx of extracellular calcium through T-type Ca²⁺ channels in smooth muscle cells.

The Effects of Adipose Stem Cell-Conditioned Media on Fibrogenesis of Dermal Fibroblasts Stimulated by Transforming Growth Factor-β1

Adipose-derived stem cells (ASCs) have been shown to enhance wound healing by human dermal fibroblasts; however, the interactions between ASCs and fibroblasts during injury remain unclear. Fibroblasts were treated with ASC-conditioned medium (ASC-CM) with and without transforming growth factor-β1 (TGF-β1) stimulation. Fibroblast proliferation, apoptosis, differentiation and expression of extracellular matrix genes and proteins, type I collagen, and type III collagen were measured. Also, wound-healing effect of ASC-CM was verified with in vivo animal study. ASC-CM inhibited proliferation and enhanced apoptosis of fibroblasts under TGF-β1 stimulation. Furthermore, 10% ASC-CM inhibited α-smooth muscle actin expression in fibroblasts, whereas 100% ASC-CM increased collagen, especially type III, expression in fibroblasts. ASC-CM was found to contain more basic fibroblast growth factor than hepatocyte growth factor, and 100% ASC-CM increased hepatocyte growth factor gene expression in fibroblasts. These results suggest ASCs affect fibrogenesis by dermal fibroblasts stimulated with TGF-β1 via paracrine signaling by adipocytokines present in ASC-CM. These results also suggest that higher concentrations of ASC-CM increase collagen production and inhibit fibroblast proliferation to avoid excessive fibrogenesis. We demonstrated that a lower ASC-CM concentration attenuated fibroblast differentiation. Additionally, 100% ASC-CM significantly reduced the wound size in an in vivo wound-healing model. In this study, we provided evidence that ASCs modulate fibrogenesis by fibroblasts via paracrine signaling, suggesting that application of ASCs during wound healing may improve the quality of wound repair.

The Role of the TGF-β Superfamily in Myocardial Infarction

The members of the transforming growth factor β (TGF-β) superfamily are essential regulators of cell differentiation, phenotype and function, and have been implicated in the pathogenesis of many diseases. Myocardial infarction is associated with induction of several members of the superfamily, including TGF-β1, TGF-β2, TGF-β3, bone morphogenetic protein (BMP)-2, BMP-4, BMP-10, growth differentiation factor (GDF)-8, GDF-11 and activin A. This manuscript reviews our current knowledge on the patterns and mechanisms of regulation and activation of TGF-β superfamily members in the infarcted heart, and discusses their cellular actions and downstream signaling mechanisms. In the infarcted heart, TGF-β isoforms modulate cardiomyocyte survival and hypertrophic responses, critically regulate immune cell function, activate fibroblasts, and stimulate a matrix-preserving program. BMP subfamily members have been suggested to exert both pro- and anti-inflammatory actions and may regulate fibrosis. Members of the GDF subfamily may also modulate survival and hypertrophy of cardiomyocytes and regulate inflammation. Important actions of TGF-β superfamily members may be mediated through activation of Smad-dependent or non-Smad pathways. The critical role of TGF-β signaling cascades in cardiac repair, remodeling, fibrosis, and regeneration may suggest attractive therapeutic targets for myocardial infarction patients. However, the pleiotropic, cell-specific, and context-dependent actions of TGF-β superfamily members pose major challenges in therapeutic translation.

Combination of HGF and IGF-1 promotes connexin 43 expression and improves ventricular arrhythmia after myocardial infarction through activating the MAPK/ERK and MAPK/p38 signaling pathways in a rat model

Background

In this study, we hypothesized that the combination of hepatocyte growth factor (HGF) and insulin-like growth factor-1 (IGF-1) alters the expression of connexin 43 (Cx43) and results in a reduced frequency of induced ventricular arrhythmia in rats after myocardial infarction (MI) and explored the preliminary mechanisms involved.

Methods

Cardiomyocytes were cultured in vitro in medium with PBS, HGF, IGF-1, GFs (HGF + IGF-1), HGF + p38 inhibitor, HGF + ERK inhibitor, IGF-1 + p38 inhibitor or IGF-1 + ERK inhibitor. The expression of Cx43 was tested by real-time PCR and Western blotting after 48 hours. MI was induced in 48 male Sprague-Dawley rats. The rats were randomly divided into four groups and received an injection of PBS, HGF, IGF-1 or GFs into the infarct border zone two weeks after MI. Six weeks after injection, the expression levels of Cx43 and programmed stimulation-induced ventricular arrhythmias were examined.

Results

In vitro, the expression of Cx43 mRNA and the Cx43 protein in cardiomyocytes was higher in the HGF, IGF-1, and GFs groups than in the PBS group. GFs had a combinatorial effect on the Cx43 mRNA level but not on the Cx43 protein level. There was a significant reduction in Cx43 mRNA and Cx43 protein levels in the IGF-1 + p38 inhibitor group and IGF-1 + ERK inhibitor group compared to the IGF-1 group. In vivo, programmed stimulation significantly decreased the frequency of ventricular arrhythmia in the GFs, HGF and IGF-1 groups, and this effect was accompanied by increased immunohistochemical staining for Cx43, myocardial Cx43 protein levels and Cx43 mRNA levels in the infarct border zone of the left ventricle compared with those in the PBS group. The combinatorial effect of GFs on Cx43 expression was only observed at the mRNA level.

Conclusions

Both HGF and IGF-1 enhanced the expression of Cx43 and improved induced ventricular arrhythmia in rats with MI. Both synergistic and antagonistic effects of HGF and IGF-1 were not observed. In addition, IGF-1 may function through the MAPK/p38 and ERK1/2 signaling pathways to regulate Cx43 expression.

Epidermal Growth Factor Stimulates Transforming Growth Factor-Beta Receptor Type II Expression In Corneal Epithelial Cells

We previously demonstrated that inhibition of epidermal growth factor receptor (EGFR) slowed corneal epithelial migration. Here we examine the effect of EGF on transforming growth factor-beta receptor II (TGF-βRII) in a corneal wound-healing model and primary human corneal epithelial cells (pHCE). Corneal debridement wounds were made and allowed to heal ± Tyrphostin AG1478 (EGFR inhibitor), and assayed for EGFR activation and EGFR and TGF-βRII localization. Primary HCE were treated with EGF ± U0126 (MEK inhibitor) and assayed for TGF-βRII expression. EGFR activation was maximal 15 minutes after wounding and localized in the migrating epithelial cells. TGF-βRII localization was also observed in the migrating epithelium and was reduced when EGFR was blocked. When pHCE were treated with EGF for 6 hours, the cells produced enhanced levels of TGF-βRII, which was blocked by U0126. Downstream signaling pathways of MEK (p38^MAPK and ERK1/2^MAPK) were then examined, and TGF-β1 and EGF were found to have differential effects on the phosphorylation of p38 and ERK1/2, with TGF-β1 upregulating p-p38 but not pERK1/2 and EGF upregulating pERK1/2 but not p-p38. Taken together, these data indicate that EGF stimulates TGF-βRII through ERK1/2 and EGFR signaling, suggesting interplay between EGF- and TGF-β-signaling pathways during corneal wound repair.

Renal Injury during Long-Term Crizotinib Therapy

Crizotinib is highly effective against anaplastic lymphoma kinase-positive and c-ros oncogen1-positive non-small cell lung cancer. Renal dysfunction is associated with crizotinib therapy but the mechanism is unknown. Here, we report a case of anaplastic lymphoma kinase positive non-small cell lung cancer showing multiple cysts and dysfunction of the kidneys during crizotinib administration. We also present results demonstrating that long-term crizotinib treatment induces fibrosis and dysfunction of the kidneys by activating the tumor necrosis factor-α/nuclear factor-κB signaling pathway. In conclusion, this study shows the renal detrimental effects of crizotinib, suggesting the need of careful monitoring of renal function during crizotinib therapy.

Nrf2 Is a Key Regulator on Puerarin Preventing Cardiac Fibrosis and Upregulating Metabolic Enzymes UGT1A1 in Rats

Puerarin is an isoflavone isolated from Radix puerariae. Emerging evidence shown that puerarin possesses therapeutic benefits that aid in the prevention of cardiovascular diseases. In this study, we evaluated the effects of puerarin on oxidative stress and cardiac fibrosis induced by abdominal aortic banding (AB) and angiotensin II (AngII). We also investigated the mechanisms underlying this phenomenon. The results of histopathological analysis, as well as measurements of collagen expression and cardiac fibroblast proliferation indicated that puerarin administration significantly inhibited cardiac fibrosis induced by AB and AngII. These effects of puerarin may reflect activation of Nrf2/ROS pathway. This hypothesis is supported by observed decreases of reactive oxygen species (ROS), decreases Keap 1, increases Nrf2 expression and nuclear translocation, and decreases of collagen expressions in cardiac fibroblasts treated with a combination of puerarin and AngII. Inhibition of Nrf2 with specific Nrf2 siRNA or Nrf2 inhibitor brusatol attenuated anti-fibrotic and anti-oxidant effects of puerarin. The metabolic effects of puerarin were mediated by Nrf2 through upregulation of UDP-glucuronosyltransferase (UGT) 1A1. The Nrf2 agonist tBHQ upregulated protein expression of UGT1A1 over time in cardiac fibroblasts. Treatment with Nrf2 siRNA or brusatol dramatically decreased UGT1A1 expression in puerarin-treated fibroblasts. The results of chromatin immunoprecipitation–qPCR further confirmed that puerarin significantly increased binding of Nrf2 to the promoter region of Ugt1a1. Western blot analysis showed that puerarin significantly inhibited AngII-induced phosphorylation of p38-MAPK. A specific inhibitor of p38-MAPK, SB203580, decreased collagen expression, and ROS generation induced by AngII in cardiac fibroblast. Together, these results suggest that puerarin prevents cardiac fibrosis via activation of Nrf2 and inactivation of p38-MAPK. Nrf2 is the key regulator of anti-fibrotic effects and upregulates metabolic enzymes UGT1A1. Autoregulatory circuits between puerarin and Nrf2-regulated UGT1A1 attenuates side effects associated with treatment, but it does not weaken puerarin’s pharmacological effects.

NMDA receptor activation inhibits the antifibrotic effect of BM-MSCs on bleomycin-induced pulmonary fibrosis

Endogenous glutamate (Glu) release and N-methyl-d-aspartate (NMDA) receptor (NMDAR) activation are associated with lung injury in different animal models. However, the underlying mechanism is unclear. Bone marrow-derived mesenchymal stem cells (BM-MSCs), which show potential use for immunomodulation and tissue protection, play a protective role in pulmonary fibrosis (PF) process. Here, we found the increased Glu release from the BM cells of bleomycin (BLM)-induced PF mice in vivo. BLM stimulation also increased the extracellular Glu in BM-MSCs via the antiporter system x_c⁻ in vitro. The gene expression of each subunit of NMDAR was detected in BM-MSCs. NMDAR activation inhibited the proliferation, migration, and paracrine function of BM-MSCs in vitro. BM-MSCs were derived from male C57BL/6 mice, transfected with lentiviral vectors carrying the enhanced green fluorescence protein gene, pretreated with NMDA, and transplanted into the female recipient mice that were intratracheally injected with BLM to induce PF. Transplantation of NMDA-pretreated BM-MSCs significantly aggravated PF as compared with that in the normal BM-MSCs transplantation group. The sex determination gene Y chromosome and green fluorescence protein genes of BM-MSCs were detected to observe BM-MSCs homing in the fibrotic lungs. Moreover, NMDAR activation inhibited BM-MSC migration by downregulating the stromal cell-derived factor-1/C-X-C chemokine receptor type 4 signaling axis. NMDAR activation aggravated the transforming growth factor-β1-induced extracellular matrix production in alveolar epithelial cells and fibroblasts through the paracrine effects of BM-MSCs. In summary, these findings suggested that NMDAR activation-mediated Glu excitotoxicity induced by BLM in BM-MSCs abolished the therapeutic effects of normal BM-MSCs transplantation on BLM-induced PF.

[Association between hepatocyte growth factor in tears and corneal haze in rabbits early after epipolis laser in situ keratomileusis]

OBJECTIVE

To study the dynamic changes of levels of hepatocyte growth factor (HGF) in tears and their association with corneal haze in rabbits early after epipolis laser in situ keratomileusis (Epi-LASIK).

METHODS

Twenty-four New Zealand rabbits received Epi-LASIK with an ablation depth of 100 µm in one eye and of 150 µm in the other eye. Before and at 3, 7, 14, and 30 days after the surgery, the level of HGF in tears collected from the rabbits was measured using enzyme-linked immunosorbent assay (ELISA), and corneal haze was graded after surgery.

RESULTS

In all the rabbits, corneal epithelium healing occurred in 3 to 5 days after Epi-LASIK. Corneal haze appeared 3 days postoperatively in the rabbits accompanied by increased levels of HGF in tears. At 3, 7, 14, and 30 days after the surgery, the rabbits with an ablation depth of 150 µm showed more obvious corneal haze (P<0.05) and significantly higher levels of HGF in tears than those with an ablation depth of 100 µm (P<0.05).

CONCLUSION

In rabbits receiving Epi-LASIK, HGF levels in tears and the grade of corneal haze show a positive correlation early after the surgery and are both related with the depth of ablation.

Nephrotoxicity Induced by Cisplatin Intake in Experimental Rats and Therapeutic Approach of Using Mesenchymal Stem Cells and Spironolactone

Chronic kidney disease may lead to subsequent tissue fibrosis. However, many factors can combat injurious stimuli in these tissues aiming to repair, heal, and alleviate any disturbance. Chemokines release, migration of inflammatory cells to the affected site, and activation of fibroblasts for the production of extracellular matrix are commonly observed in this disease. In the last years, many studies have focused on spironolactone (SPL), a mineralocorticoid receptor antagonist, and its pharmacological effects. In the present study, SPL was selected as an anti-inflammatory agent to combat nephrotoxicity and renal fibrosis induced by cisplatin. Mesenchymal stem cells (MSCs) were also selected in addition as a referring agent. Renal fibrosis induced by cisplatin intake significantly increased creatinine, urea, nuclear factor kappa B, insulin-like growth factor-1, fibroblast growth factor-23, and kidney malondialdehyde (MDA) content. Hepatocyte growth factor and renal content of reduced glutathione demonstrated a significant decrease. Histopathological examination of kidney tissues demonstrated marked cellular changes which are correlated with the biochemical results. Oral SPL intake (20 mg/kg/body weight) daily for 4 weeks and MSCs administration (3 × 10⁶ cell/rat) intravenous to the experimental rats resulted in a significant improvement of both the biomarkers studied and the histopathological profile of the renal tissue. Individual administration of spironolactone and MSCs exhibited a marked anti-inflammatory potential and alleviated to a great extent the nephrotoxicity and renal fibrotic pattern induced by cisplatin.

Naringenin inhibits transforming growth factor-β1-induced cardiac fibroblast proliferation and collagen synthesis via G0/G1 arrest

The Traditional Chinese Medicine naringenin (NRG) has a number of biological effects, including anti-inflammatory, anti-oxidative, anti-tumor and anti-atherosclerotic effects. However, the mechanism underlying its effects remains unclear. The aim of the present study is to investigate the role and mechanism of NRG on proliferation and collagen synthesis of cardiac fibroblasts (CFs) induced by transforming growth factor β1 (TGF-β1). Firstly, proliferation and collagen synthesis in CFs subjected to TGF-β1 was assessed subsequent to the consumption of NRG or control treatment. Additionally, the cell cycle of different groups and the roles of cyclins and cyclin-dependent kinases (CDKs) in NRG treatment of CFs were detected. In the present study, it was revealed that treatment of CFs with NRG resulted in attenuated fibroblast α-smooth muscle actin expression, deceased proliferation and collagen synthesis when compared with a TGF-β1 stimulus. Additionally, it was demonstrated that cell population of CFs treated with NRG in the S-phase became smaller whereas that of CFs in the G0/G1-phase increased when compared with the TGF-β1 group. Mechanistically, the expression of cyclin D1-CDK4/6 and cyclin E2-CDK2 were inhibited in the NRG treatment group. These results illustrated that the protective effects of NRG on proliferation and collagen synthesis of CFs were at least in part due to G0/G1 arrest. Therefore, NRG may become a novel strategy for treating cardiac fibrosis in the future.

Hepatocyte Growth Factor Mediates Enhanced Wound Healing Responses and Resistance to Transforming Growth Factor-β₁-Driven Myofibroblast Differentiation in Oral Mucosal Fibroblasts

Oral mucosal wounds are characterized by rapid healing with minimal scarring, partly attributable to the "enhanced" wound healing properties of oral mucosal fibroblasts (OMFs). Hepatocyte growth factor (HGF) is a pleiotropic growth factor, with potential key roles in accelerating healing and preventing fibrosis. HGF can exist as full-length or truncated (HGF-NK), NK1 and NK2 isoforms. As OMFs display elevated HGF expression compared to dermal fibroblasts (DFs), this study investigated the extent to which HGF mediates the preferential cellular functions of OMFs, and the influence of pro-fibrotic, transforming growth factor-β₁ (TGF-β₁) on these responses. Knockdown of HGF expression in OMFs by short-interfering RNA (siHGF) significantly inhibited OMF proliferative and migratory responses. Supplementation with exogenous TGF-β₁ also significantly inhibited proliferation and migration, concomitant with significantly down-regulated HGF expression. In addition, knockdown abrogated OMF resistance to TGF-β₁-driven myofibroblast differentiation, as evidenced by increased α-smooth muscle actin (α-SMA) expression, F-actin reorganisation, and stress fibre formation. Responses were unaffected in siHGF-transfected DFs. OMFs expressed significantly higher full-length HGF and NK1 levels compared to patient-matched DFs, whilst NK2 expression was similar in both OMFs and DFs. Furthermore, NK2 was preferentially expressed over NK1 in DFs. TGF-β₁ supplementation significantly down-regulated full-length HGF and NK1 expression by OMFs, while NK2 was less affected. This study demonstrates the importance of HGF in mediating "enhanced" OMF cellular function. We also propose that full-length HGF and HGF-NK1 convey desirable wound healing properties, whilst fibroblasts preferentially expressing more HGF-NK2 readily undergo TGF-β₁-driven differentiation into myofibroblasts.

The role of transforming growth factor (TGF)-β in the infarcted myocardium

The adult mammalian heart has negligible regenerative capacity. Following myocardial infarction, sudden necrosis of cardiomyocytes triggers an intense inflammatory reaction that clears the wound from dead cells and matrix debris, while activating a reparative program. A growing body of evidence suggests that members of the transforming growth factor (TGF)-β family critically regulate the inflammatory and reparative response following infarction. Although all three TGF-β isoforms (TGF-β1, -β2 and -β3) are markedly upregulated in the infarcted myocardium, information on isoform-specific actions is limited. Experimental studies have suggested that TGF-β exerts a wide range of actions on cardiomyocytes, fibroblasts, immune cells, and vascular cells. The findings are often conflicting, reflecting the context-dependence of TGF-β-mediated effects; conclusions are often based exclusively on in vitro studies and on associative evidence. TGF-β has been reported to modulate cardiomyocyte survival responses, promote monocyte recruitment, inhibit macrophage pro-inflammatory gene expression, suppress adhesion molecule synthesis by endothelial cells, promote myofibroblast conversion and extracellular matrix synthesis, and mediate both angiogenic and angiostatic effects. This review manuscript discusses our understanding of the cell biological effects of TGF-β in myocardial infarction. We discuss the relative significance of downstream TGF-β-mediated Smad-dependent and -independent pathways, and the risks and challenges of therapeutic TGF-β targeting. Considering the high significance of TGF-β-mediated actions in vivo, study of cell-specific effects and dissection of downstream signaling pathways are needed in order to design safe and effective therapeutic approaches.

Oncostatin M-Preconditioned Mesenchymal Stem Cells Alleviate Bleomycin-Induced Pulmonary Fibrosis Through Paracrine Effects of the Hepatocyte Growth Factor

Mesenchymal stem cells (MSCs) are widely considered for treatment of pulmonary fibrosis based on the anti‐inflammatory, antifibrotic, antiapoptotic, and regenerative properties of the cells. Recently, elevated levels of oncostatin M (OSM) have been reported in the bronchoalveolar lavage fluid of a pulmonary fibrosis animal model and in patients. In this work, we aimed to prolong engrafted MSC survival and to enhance the effectiveness of pulmonary fibrosis transplantation therapy by using OSM‐preconditioned MSCs. OSM‐preconditioned MSCs were shown to overexpress type 2 OSM receptor (gp130/OSMRβ) and exhibited high susceptibility to OSM, resulting in upregulation of the paracrine factor, hepatocyte growth factor (HGF). Moreover, OSM‐preconditioned MSCs enhanced cell proliferation and migration, attenuated transforming growth factor‐β1‐ or OSM‐induced extracellular matrix production in MRC‐5 fibroblasts through paracrine effects. In bleomycin‐induced lung fibrotic mice, transplantation of OSM‐preconditioned MSCs significantly improved pulmonary respiratory functions and downregulated expression of inflammatory factors and fibrotic factors in the lung tissues. Histopathologic examination indicated remarkable amelioration of the lung fibrosis. LacZ‐tagged MSCs were detected in the lung tissues of the OSM‐preconditioned MSC‐treated mice 18 days after post‐transplantation. Taken together, our data further demonstrated that HGF upregulation played an important role in mediating the therapeutic effects of transplanted OSM‐preconditioned MSCs in alleviating lung fibrosis in the mice. Stem Cells Translational Medicine2017;6:1006–1017

Restoration of Corneal Transparency by Mesenchymal Stem Cells

Transparency of the cornea is indispensable for optimal vision. Ocular trauma is a leading cause of corneal opacity, leading to 25 million cases of blindness annually. Recently, mesenchymal stem cells (MSCs) have gained prominence due to their inflammation-suppressing and tissue repair functions. Here, we investigate the potential of MSCs to restore corneal transparency following ocular injury. Using an in vivo mouse model of ocular injury, we report that MSCs have the capacity to restore corneal transparency by secreting high levels of hepatocyte growth factor (HGF). Interestingly, our data also show that HGF alone can restore corneal transparency, an observation that has translational implications for the development of HGF-based therapy.

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Inflammation drives MSCs to secrete elevated levels of hepatocyte growth factor (HGF)

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MSC-derived HGF restores corneal transparency by inhibiting myofibroblast generation

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HGF alone can restore corneal transparency

Cardiac concentric hypertrophy promoted by activated Met receptor is mitigated in vivo by inhibition of Erk1,2 signalling with Pimasertib

Cardiac hypertrophy is a major risk factor for heart failure. Hence, its attenuation represents an important clinical goal. Erk1,2 signalling is pivotal in the cardiac response to stress, suggesting that its inhibition may be a good strategy to revert heart hypertrophy. In this work, we unveiled the events associated with cardiac hypertrophy by means of a transgenic model expressing activated Met receptor. c-Met proto-oncogene encodes for the tyrosine kinase receptor of Hepatocyte growth factor and is a strong inducer of Ras-Raf-Mek-Erk1,2 pathway. We showed that three weeks after the induction of activated Met, the heart presents a remarkable concentric hypertrophy, with no signs of congestive failure and preserved contractility. Cardiac enlargement is accompanied by upregulation of growth-regulating transcription factors, natriuretic peptides, cytoskeletal proteins, and Extracellular Matrix remodelling factors (Timp1 and Pai1). At a later stage, cardiac hypertrophic remodelling results into heart failure with preserved systolic function. Prevention trial by suppressing activated Met showed that cardiac hypertrophy is reversible, and progression to heart failure is prevented. Notably, treatment with Pimasertib, Mek1 inhibitor, attenuates cardiac hypertrophy and remodelling. Our results suggest that modulation of Erk1.2 signalling may constitute a new therapeutic approach for treating cardiac hypertrophies.

Berberine regulates proliferation, collagen synthesis and cytokine secretion of cardiac fibroblasts via AMPK-mTOR-p70S6K signaling pathway

OBJECTIVE

The traditional Chinese medicinal berberine has long been used to treat cardiovascular diseases; however, the mechanism underlying its effects remains unclear. Here, this study would to investigate the effects of berberine on proliferation, collagen synthesis and cytokine secretion of cardiac fibroblasts.

METHODS

We assessed proliferation, collagen synthesis and cytokine secretion in cardiac fibroblasts subjected to angiotensin II (Ang II) subsequent to the consumption of berberine or a control treatment. And then we detected the role of AMPK/mTOR signaling pathway in berberine treatment of cardiac fibroblasts.

RESULTS

In the present study, the cellular behaviors of cardiac fibroblasts induced by Ang II were significantly activated including proliferation, transformation into myofibroblasts and collagen synthesis. Additionally, the ability of cytokine secretion was enhanced obviously. It was demonstrated that treatment of cardiac fibroblasts with berberine resulted in deceased proliferation, and attenuated fibroblast α-smooth muscle actin expression and collagen synthesis. And the protein secretion of TGFβ1 was inhibited; however, the protein secretion of IL-10 was increased in cardiac fibroblasts with berberine treatment. Mechanistically, the phosphorylation level of AMPK was increased; and the phosphorylation levels of mTOR and p70S6K were decreased in berberine treatment group.

CONCLUSION

These results illustrated that the protective effects of berberine on cellular behaviors of cardiac fibroblasts were at least in part due to activate AMPK signaling pathway and downregulate mTOR/p70S6K signaling pathway. Berberine might become a new strategy for treating cardiac fibrosis in the future.

Toxicity of nickel ions and comprehensive analysis of nickel ion-associated gene expression profiles in THP-1 cells

The aim of the present study was to explore the toxic effects and underlying mechanisms of nickel ions during therapeutic nickel‑based alloy‑treatment in congenital heart disease by investigating the metal‑induced cytotoxicity to the human monocyte‑derived macrophage cell line THP‑1. THP‑1 cells were treated with NiCl2·6H2O (25, 50, 100, 200, 400 and 800 µM) for 24, 48 and 72 h, respectively. MTT was applied to detect THP‑1 cell proliferation following NiCl2 treatment. Apoptosis of THP‑1 cells was quantified using flow cytometry. Illumina sequencing was used for screening the associated genes, whose mRNA expression levels were further confirmed by quantitative real‑time polymerase chain reaction. High concentrations of nickel ions had a significant suppressive effect on cell proliferation at the three concentrations investigated (200, 400 and 800 µM). Treatment with nickel ions (25‑400 µM) for 48 h reduced cell viability in a dose‑dependent manner. The mRNA expression levels of RELB, FIGF, SPI‑1, CXCL16 and CRLF2 were significantly increased following nickel treatment. The results of the present study suggested that nickel ions exert toxic effects on THP‑1 cell growth, which may indicate toxicity of the nickel ion during treatment of congenital heart disease. The identification of genes modified by the toxic effects of nickel on THP‑1 cells (EPOR, RELB, FIGF, SPI‑1, TGF‑β1, CXCL16 and CRLF2) may aid in the development of interventional measures for the treatment/prevention of nickel ion‑associated toxic effects during the treatment of congenital heart disease.

C1q/tumor necrosis factor-related protein-6 attenuates post-infarct cardiac fibrosis by targeting RhoA/MRTF-A pathway and inhibiting myofibroblast differentiation

C1q/tumor necrosis factor-related protein-6 (CTRP6) is a newly identified adiponectin paralog with modulation effects on metabolism and inflammation. However, the cardiovascular function of CTRP6 remains unknown. This study aimed to determine its role in cardiac fibrosis and explore the possible mechanism. Myocardial infarction (MI) was induced by left anterior descending coronary artery ligation in rats. CTRP6 was mainly expressed in the cytoplasm of adult rat cardiomyocytes and significantly decreased in the border and infarct zones post-MI. Adenovirus-mediated CTRP6 delivery improved cardiac function, attenuated cardiac hypertrophy, alleviated cardiac fibrosis, and inhibited myofibroblast differentiation as well as the expression of collagen I, collagen III, and connective tissue growth factor post-MI. In cultured adult rat cardiac fibroblasts (CFs), exogenous or cardiomyocyte-secreted CTRP6 inhibited, whereas knockdown of CTRP6 facilitated transforming growth factor-β1 (TGF-β1)-induced expression of α-smooth muscle actin, smooth muscle 22α, and profibrotic molecules. CTRP6 had no effect on CFs proliferation but attenuated CFs migration induced by TGF-β1. CTRP6 increased the phosphorylation of AMP-activated protein kinase (AMPK) and Akt in CFs and post-MI hearts. Pretreatment with adenine 9-β-D-arabinofuranoside (AraA), an AMPK inhibitor, or LY294002, a phosphatidylinositol-3-kinase (PI3 K) inhibitor, abolished the protective effect of CTRP6 on TGF-β1-induced profibrotic response. Furthermore, CTRP6 had no effect on TGF-β1-induced Smad3 phosphorylation and nuclear translocation, whereas significantly decreased TGF-β1-induced RhoA activation and myocardin-related transcription factor-A (MRTF-A) nuclear translocation, and these effects were blocked by AMPK or Akt inhibition. In conclusion, CTRP6 attenuates cardiac fibrosis via inhibiting myofibroblast differentiation. AMPK and Akt activation are responsible for the CTRP6-mediated anti-fibrotic effect by targeting RhoA/MRTF-A pathway.

Effects of angiotensin II on transient receptor potential melastatin 7 channel function in cardiac fibroblasts

The aim of the present study was to investigate the electrophysiological properties of transient receptor potential melastatin 7 (TRPM7) channels in the cell membranes of cardiac fibroblasts (CFs). CFs obtained from Sprague-Dawley rats were treated with six different concentrations of angiotensin (Ang) II for 12 h. The optimum concentration of Ang II for inducing fibrosis was selected by measuring collagen protein expression levels at each concentration. The optimum concentration of Ang II was then used to treat the CFs at five different time-points, and the TRPM7 current across the CF membranes was recorded along with the collagen protein levels in each group. The optimum Ang II concentration for inducing fibrosis was found to be 1 nmol/l; when it was administered to CFs at 0, 6, 12, 24 and 48 h, the protein expression levels of TRPM7 and collagen III initially increased, reaching maximum levels at 12 h, and then decreased. This result positively correlated with the TRPM7 current levels on either side of the CF membranes: The TRPM7 current under the effect of the optimal Ang II concentration for inducing fibrosis was initially increased and then later decreased. This is one of the key mechanisms by which Ang II mediates the proliferation and apoptosis of CFs. This knowledge may be used to identify treatments for the prevention of cardiac fibrosis.

Genistein alleviates pressure overload-induced cardiac dysfunction and interstitial fibrosis in mice

BACKGROUND AND PURPOSE

Pressure overload-induced cardiac interstitial fibrosis is viewed as a major cause of heart failure in patients with hypertension or aorta atherosclerosis. The purpose of this study was to investigate the effects and the underlying mechanisms of genistein, a natural phytoestrogen found in soy bean extract, on pressure overload-induced cardiac fibrosis.

EXPERIMENTAL APPROACH

Genisten was administered to mice with pressure overload induced by transverse aortic constriction. Eight weeks later, its effects on cardiac dysfunction, hypertrophy and fibrosis were determined. Its effects on proliferation, collagen production and myofibroblast transformation of cardiac fibroblasts (CFs) and the signalling pathways were also assessed in vitro.

KEY RESULTS

Pressure overload-induced cardiac dysfunction, hypertrophy and fibrosis were markedly attenuated by genistein. In cultured CFs, genistein inhibited TGFβ1-induced proliferation, collagen production and myofibroblast transformation. Genistein suppressed TGFβ-activated kinase 1 (TAK1) expression and produced anti-fibrotic effects by blocking the TAK1/MKK4/JNK pathway. Further analysis indicated that it up-regulated oestrogen-dependent expression of metastasis-associated gene 3 (MTA3), which was found to be a negative regulator of TAK1. Silencing MTA3 by siRNA, or inhibiting the activity of the MTA3-NuRD complex with trichostatin A, abolished genistein's anti-fibrotic effects.

CONCLUSIONS AND IMPLICATIONS

Genistein improved cardiac function and inhibited cardiac fibrosis in response to pressure overload. The underlying mechanism may involve regulation of the MTA3/TAK1/MKK4/JNK signalling pathway. Genistein may have potential as a novel agent for prevention and therapy of cardiac disorders associated with fibrosis.

Hepatocyte growth factor-modified adipose tissue-derived stem cells improve erectile function in streptozotocin-induced diabetic rats

TGFβ1-Smad signaling pathway is closely related to various tissues fibrosis. Hepatocyte growth factor (HGF) has been shown to antagonize TGFβ1-Smad signaling and may improve kidney tissue fibrosis in diabetic models. Penile fibrosis is a pathological condition which occurs during diabetic erectile dysfunction (ED). The aim of this study was to examine the effect of the treatment of ED in diabetic rats with a combination of HGF and adipose tissue-derived stem cells (ADSC). In this diabetes model, rats were injected intraperitoneally with 60 mg streptozotocin (STZ) to induce diabetes. Three months later, the diabetic rats were divided into a negative control(NC) group, an ADSC-treated group and an ADSC + HGF-treated group while normal rats were assigned into a sham group. Rats in the sham and NC groups were injected in the corpus cavernosum with phosphate-buffered saline, while rats in the other groups were injected with either ADSC or ADSC + HGF. One month later, erectile function was examined in each group and penile tissues were collected for experiments. The expression of smooth muscle actin (SMA) and platelet-endothelial cell adhesion molecule-1 (PECAM-1) was analyzed by Western blotting. The smooth muscle and collagen deposition in corpus cavernosum was evaluated by Masson staining, while endothelial changes were assessed immunohistochemically. Cell apoptosis was detected by the TdT-mediated dUTP nick-end labeling (TUNEL) assay. The results revealed that ADSC alone can significantly improve erectile function in diabetic rats, but in combination with HGF the improvement was more prominent, showing higher content of smooth muscle and endothelial cells and lower cell apoptotic index in corpus cavernosum. Treatment with HGF can significantly enhance the beneficial effect of ADSC on erectile function in diabetic rats, and this effect might be closely related to the down-regulation of TGFβ1-Smad signaling.