IL-15 Prevents Renal Fibrosis by Inhibiting Collagen Synthesis: A New Pathway in Chronic Kidney Disease?

Chronic kidney disease (CKD), secondary to renal fibrogenesis, is a public health burden. The activation of interstitial myofibroblasts and excessive production of extracellular matrix (ECM) proteins are major events leading to end-stage kidney disease. Recently, interleukin-15 (IL-15) has been implicated in fibrosis protection in several organs, with little evidence in the kidney. Since endogenous IL-15 expression decreased in nephrectomized human allografts evolving toward fibrosis and kidneys in the unilateral ureteral obstruction (UUO) model, we explored IL-15's renoprotective role by pharmologically delivering IL-15 coupled or not with its soluble receptor IL-15Rα. Despite the lack of effects on myofibroblast accumulation, both IL-15 treatments prevented tubulointerstitial fibrosis (TIF) in UUO as characterized by reduced collagen and fibronectin deposition. Moreover, IL-15 treatments inhibited collagen and fibronectin secretion by transforming growth factor-ß (TGF-ß)-treated primary myofibroblast cultures, demonstrating that the antifibrotic effect of IL-15 in UUO acts, in part, through a direct inhibition of ECM synthesis by myofibroblasts. In addition, IL-15 treatments resulted in decreased expression of monocyte chemoattractant protein 1 (MCP-1) and subsequent macrophage infiltration in UUO. Taken together, our study highlights a major role of IL-15 on myofibroblasts and macrophages, two main effector cells in renal fibrosis, demonstrating that IL-15 may represent a new therapeutic option for CKD.

The effect of Guanxin Shutong capsule on alleviating the myocardial fibrosis in heart failure rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Guanxin Shutong (GXST) capsule is a renowned traditional Chinese medicine widely used for the treatment of cardiovascular diseases in the clinic. However, no pharmacological experimental studies of GXST has been reported on the treatment of pressure overload-induced heart failure. This study aimed to investigate the effects of GXST capsule on ameliorating myocardial fibrosis conditions in pressure overload-induced heart failure rats. MATERIAL AND METHODS: Rats were randomly divided into 6 groups: Normal group, Model group, GXST-treated group at a dose of 0.5 g/kg, 1 g/kg, 2 g/kg, respectively, and digoxin positive control group at a dose of 1 mg/kg. After 4 weeks of administration, cardiac function was evaluated by echocardiography. Cardiac injury and fibrotic conditions were evaluated by H&E staining, Masson staining, and Sirius Red staining. Myocardial fibrosis was evaluated by immunohistochemistry staining and Western blot. RESULTS: GXST significantly inhibited cardiac fibrosis, reduced the excessive deposition of collagen, and finally improved cardiac function. GXST reversed ventricular remodeling might be through the TGF-ß/Smad3 pathway. CONCLUSION: GXST capsule demonstrated a strong anti-fibrosis effect in heart failure rats by inhibiting the TGF-ß/Smad3 signaling pathway.

Adrenomedullin Ameliorates Pulmonary Fibrosis by Regulating TGF-ß-Smads Signaling and Myofibroblast Differentiation.

Pulmonary fibrosis is an irreversible, potentially fatal disease. Adrenomedullin (AM) is a multifunctional peptide whose activity is regulated by receptor activity-modifying protein 2 (RAMP2). In the present study, we used the bleomycin (BLM)-induced mouse pulmonary fibrosis model to investigate the pathophysiological significance of the AM-RAMP2 system in the lung. In heterozygous AM knockout mice (AM+/-), hydroxyproline content and Ashcroft scores reflecting the fibrosis severity were significantly higher than in wild-type mice (WT). During the acute phase after BLM administration, FACS analysis showed significant increases in eosinophil, monocyte, and neutrophil infiltration into the lungs of AM+/-. During the chronic phase, fibrosis-related molecules were upregulated in AM+/-. Notably, nearly identical changes were observed in RAMP2+/-. AM administration reduced fibrosis severity. In the lungs of BLM-administered AM+/-, the activation level of Smad3, a receptor-activated Smad, was higher than in WT. In addition, Smad7, an antagonistic Smad, was downregulated and microRNA-21, which targets Smad7, was upregulated compared to WT. Isolated AM+/- lung fibroblasts showed less proliferation and migration capacity than WT fibroblasts. Stimulation with TGF-ß increased the numbers of α-SMA-positive myofibroblasts, which were more prominent among AM+/- cells. TGF-ß-stimulated AM+/- myofibroblasts were larger and exhibited greater contractility and extracellular matrix production than WT cells. These cells were α-SMA (+), F-actin (+), and Ki-67(-) and appeared to be nonproliferating myofibroblasts (non-p-MyoFbs), which contribute to the severity of fibrosis. Our findings suggest that in addition to suppressing inflammation, the AM-RAMP2 system ameliorates pulmonary fibrosis by suppressing TGF-ß-Smad3 signaling, microRNA-21 activity and differentiation into non-p-MyoFbs.

The Scar-in-a-Jar: In Vitro Fibrosis Model for Anti-Fibrotic Drug Testing.

Excessive deposition of type I collagen follows in the wake of chronic inflammation processes in dysregulated tissue healing and causes fibrosis that can ultimately lead to organ failure. While the development of antifibrotic drugs is targeting various upstream events in collagen matrix formation (synthesis, secretion, deposition, stabilization, remodeling), the evaluation of drug effects would use as net read-out of the above effects the presence of a deposited collagen matrix by activated cells, mainly myofibroblasts. Conventional methods comprise lengthy and labor-intensive protocols for the quantification of deposited collagen, some with sensitivity and/or specificity issues. Here we describe the Scar-in-a-Jar assay, an in vitro fibrosis model for anti-fibrotic drug testing that benefits from a substantially accelerated extracellular matrix deposition employing macromolecular crowding and a collagen-producing cell type of choice (e.g., lung fibroblasts like WI-38). The system can be aided by activating compounds such as transforming growth factor-ß1, a classical inducer of the myofibroblast phenotype in fibroblasts. Direct image analysis of the well plate not only eliminates the need for matrix extraction or solubilization methods, but also allows for direct imaging and monitoring of phenotypical markers and offers the option for high-content screening applications when adapted to well formats compatible with a screening format.

Huoxin Pill inhibits isoproterenol-induced transdifferentiation and collagen synthesis in cardiac fibroblasts through the TGF-ß/Smads pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: The abnormal proliferation and differentiation of cardiac fibroblasts (CFs) are universally regarded as the key process for the progressive development of cardiac fibrosis following various cardiovascular diseases. Huoxin Pill (Concentrated pill, HXP) is a Chinese herbal formula for treating coronary heart disease. However, the cellular and molecular mechanisms of HXP in the treatment of myocardial fibrosis are still unclear. AIM OF THE STUDY: To investigate the effects of HXP on CFs transdifferentiation and collagen synthesis under isoproterenol (ISO) conditions, as well as the potential mechanism of action. MATERIALS AND METHODS: In vivo, we established a rat model of cardiac fibrosis induced by ISO, and administered with low or high dose of HXP (10 mg/kg/day or 30 mg/kg/day). The level of α-SMA was detected by immunohistochemistry examination, and combined with RNA-sequencing analysis to determine the protective effect of HXP on myocardial fibrosis rats. In vitro, by culturing primary rat CFs, we examined the effects of HXP on the proliferation and transdifferentiation of CFs using CCK8, scratch wound healing and immunofluorescence assays. Western blot was used to determine protein expression. RESULTS: The findings revealed that HXP protects against ISO-induced cardiac fibrosis and CFs transdifferentiation in rats. RNA-sequencing and pathway analyses demonstrated 238 or 295 differentially expressed genes (DEGs) and multiple enriched signal pathways, including transforming growth factor-beta (TGF-ß) receptor signaling activates Smads, downregulation of TGF-ß receptor signaling, signaling by TGF-ß receptor complex, and collagen formation under treatment with low or high-dose of HXP. Moreover, HXP also markedly inhibited ISO-induced primary rat CFs proliferation, transdifferentiation, collagen synthesis and the upregulation of TGF-ß1 and phosphorylated Smad2/3 protein expression. CONCLUSION: HXP suppresses ISO-induced CFs transdifferentiation and collagen synthesis, and it may exert these effects in part by inhibiting the activation of the TGF-ß/Smads pathway. This may be a new therapeutic tool for cardiac fibrosis.

Salvianolic acid B inhibits myofibroblast differentiation and extracellular matrix accumulation in nasal polyp fibroblasts via the TGF-ß1 signaling pathway.

In the process of nasal tissue remodeling, nasal fibroblasts serve an important role via myofibroblast differentiation and the production of extracellular matrix (ECM). Nasal fibroblast abnormalities can lead to conditions such as chronic rhinosinusitis. Salvianolic acid B (Sal B), a water-soluble active pharmaceutical compound extract from the root of the traditional Chinese medicine Salvia miltiorrhiza, displays antioxidative, antiproliferative and antifibrosis properties. The present study aimed to investigate the mechanism underlying the effects of Sal B on nasal polyp fibroblast (NPF) myofibroblast differentiation and ECM accumulation. Primary NPFs were obtained from nasal polyps of patients with chronic sinusitis. The proliferative and cytotoxic effects of Sal B on NPFs were evaluated by performing the Cell Counting Kit-8 assay. The Transwell assay was conducted to assess cell migration. α-smooth muscle actin (α-SMA), TGF-ß1 receptor (TßR)-I, TßR-II, Smad2/3 mRNA and protein expression levels and (p)-Smad2/3 phosphorylation levels were measured via reverse transcription-quantitative PCR and western blotting, respectively. Type III collagen and fibronectin levels were analyzed by ELISA. The results indicated that Sal B significantly downregulated TGF-ß1-induced α-SMA, fibronectin and collagen III expression levels in NPFs. Similarly, Sal B significantly decreased TGF-ß1-induced TßR-I, TßR-II, p-Smad2/3, MMP-2 and MMP-9 mRNA and protein expression levels in NPFs. Furthermore, Sal B significantly decreased TGF-ß1-induced NPF migration. Therefore, the present study indicated that Sal B inhibited myofibroblast differentiation and ECM accumulation in nasal fibroblasts, suggesting that Sal B may inhibit nasal polyp formation via certain mechanisms.

Inhibition of proliferation-linked signaling cascades with atractylenolide I reduces myofibroblastic phenotype and renal fibrosis.

Renal fibrosis is a frequent axis contributing to the occurrence of end-stage nephropathy. Previously, it has been reported that atractylenolide Ⅰ (ATL-1), a natural compound extracted from Atractylodes macrocephala, has anti-cancer and antioxidant effects. However, the renal anti-fibrotic effects of action remain unclear. In this study, the anti-fibrotic effects of ATL-1 were examined in fibroblasts, tubular epithelial cells (TECs) triggered by TGF-ß1 in vitro, and using a unilateral ureteral obstruction (UUO) mouse model in vivo. We found that ATL-1 represses the myofibroblastic phenotype and fibrosis development in UUO kidneys by targeting the fibroblast-myofibroblast differentiation (FMD), as well as epithelial-mesenchymal transition (EMT). The anti-fibrotic effects of ATL-1 were associated with reduced cell growth in the interstitium and tubules, leading to suppression of the proliferation-linked cascades activity consisting of JAK2/STAT3, PI3K/Akt, p38 MAPK, and Wnt/ß-catenin pathways. Besides, ATL-1 treatment repressed TGF-ß1-triggered FMD and the myofibroblastic phenotype in fibroblasts by antagonizing the activation of proliferation-linked cascades. Likewise, TGF-ß1-triggered excessive activation of the proliferation-linked signaling in TECs triggered EMT. The myofibroblastic phenotype was repressed by ATL-1. The anti-fibrotic and anti-proliferative effects of ATL-1 were linked to the inactivation of Smad2/3 signaling, partially reversing FMD, as well as EMT and the repression of the myofibroblastic phenotype. Thus, the inhibition of myofibroblastic phenotype and fibrosis development in vivo and in vitro through proliferation-linked cascades of ATL-1 makes it a prospective therapeutic bio-agent to prevent renal fibrosis.

Betulinic acid attenuated bleomycin-induced pulmonary fibrosis by effectively intervening Wnt/ß-catenin signaling.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fatal and progressive fibrotic lung disease lacking a validated and effective therapy. Aberrant activation of the Wnt/ß-catenin signaling cascade plays the key role in the pathogenesis of IPF. Betulinic acid is a natural pentacyclic triterpenoid molecule that has excellent antitumor and antiviral activities. HYPOTHESIS: We hypothesized that BA has an anti-pulmonary fibrosis effect mediated by the suppression of the Wnt/ß-catenin pathway. Study design Pulmonary fibrosis markers were detected in vitro and in vivo to confirm the antifibrotic effect of BA. The Wnt/ß-catenin pathway-related proteins were overexpressed to determine the effect of BA on Wnt signaling. METHODS AND RESULTS: BA dose-dependently inhibited Wnt3a-induced fibroblast activation in vitro. Moreover, BA decreased Wnt3a- and LiCl-induced transcriptional activity, as assessed by the TOPFlash assay in fibroblasts, and repressed the expression of the Wnt target genes cyclin D1, axin 2, and S100A4. Further investigation indicated that BA restrained the nuclear accumulation of ß-catenin, mainly by increasing the phospho-ß-catenin ratio (S33/S37/T41 and S45), inhibited the phosphorylation of DVL2 and LRP, and decreased the levels of Wnt3a and LRP6. In agreement with the results of the in vitro assays, the in vivo experiments indicated that BA significantly decreased bleomycin-induced pulmonary fibrosis in mice and suppressed myofibroblast activation by inhibiting Wnt/ß-catenin signaling. CONCLUSION: BA may directly interfere with the Wnt/ß-catenin pathway to subsequently repress myofibroblast activation and pulmonary fibrosis.

Mechanism of turnover or persistence of radiation-induced myofibroblast in vitro.

We recently made an important discovery that radiation induces myofibroblasts, which play a role in radiation-related carcinogenesis via tumor microenvironment formation. Here, we investigated the threshold dose and the mechanisms of myofibroblast induction to assess adverse radiation effects on normal cells. Single-dose of healthy human fibroblasts in vitro promotes myofibroblast induction at high doses (≥ 5 Gy). In contrast, repeated low dose of fractionated radiation is at least equivalent to high-dose single radiation regarding myofibroblast induction. ROS play a pivotal role in the process of myofibroblast induction in normal tissue injury. Antioxidants, such as epicatechin and ascorbic acid can prevent myofibroblast induction by scavenging ROS. We further investigated the role of DNA damage responses (DDR) on myofibroblast induction. Blocking the DDR using DNA-PK or AKT inhibitors enhanced cellular sensitivity to radiation and facilitated myofibroblast induction, whereas an ATM inhibitor also enhanced radiation sensitivity but abrogated ROS accumulation and myofibroblast induction. In contrast to standard culture conditions, myofibroblasts remained after low or moderate doses of radiation (below 2.5 Gy) under growth-restricted conditions. In conclusion, the recovery of damaged cells from radiation is essential for myofibroblast clearance, which restores stromal cell dormancy and prevents tumor microenvironment formation. However, residual ROS, by way of sustaining myofibroblast presence, can facilitate tumor microenvironment formation. Targeting ROS using antioxidants is effective in the mitigation of radiation-related adverse effects, such as growth retardation and myofibroblast induction, and helps protect normal tissues.

Biochanin-A ameliorates pulmonary fibrosis by suppressing the TGF-ß mediated EMT, myofibroblasts differentiation and collagen deposition in in vitro and in vivo systems.

BACKGROUND: Idiopathic Pulmonary Fibrosis (IPF) is a progressive inflammatory disorder driven by a fibrotic cascade of events such as epithelial to mesenchymal transition, extracellular matrix production and collagen formation in the lungs in a sequential manner. IPF incidences were raising rapidly across the world. FDA approved pirfenidone and nintedanib (tyrosine kinase inhibitors) are being used as a first-line treatment drugs for IPF, however, neither the quality of life nor survival rates have been improved because of patient noncompliance due to multiple side effects. Thus, the development of novel therapeutic approaches targeting TGF-ß mediated cascade of fibrotic events is urgently needed to improve the survival of the patients suffering from devastating disease. PURPOSE: The aim of this study was to investigate and validate the anti-fibrotic properties of Biochanin-A (isoflavone) against TGF-ß mediated fibrosis in in vitro, ex vivo, in vivo models and to determine the molecular mechanisms that mediate these anti-fibrotic effects. METHODS: The therapeutic activity of BCA was determined in in vitro/ex vivo models. Cells were pre-treated with BCA and incubated in presence or absence of recombinant-TGF-ß to stimulate the fibrotic cascade of events. Pulmonary fibrosis was developed by intratracheal administration of bleomycin in rats. BCA treatment was given for 14 days from post bleomycin instillation and then various investigations (collagen content, fibrosis gene/protein expression and histopathological changes) were performed to assess the anti-fibrotic activity of BCA. RESULTS: In vitro/ex vivo (Primary normal, IPF cell line and primary IPF cells/ Precision cut mouse lung slices) experiments revealed that, BCA treatment significantly (p < 0.001) reduced the expression of TGF-ß modulated fibrotic genes/protein expressions (including their functions) which are involved in the cascade of fibrotic events. BCA treatment significantly (p < 0.01) reduced the bleomycin-induced inflammatory cell-infiltration, inflammatory markers expression, collagen deposition and expression of fibrotic markers in lung tissues equivalent or better than pirfenidone treatment. In addition, BCA treatment significantly (p < 0.001) attenuated the TGF-ß1/BLM-mediated increase of TGF-ß/Smad2/3 phosphorylation and resulted in the reduction of pathological abnormalities in lung tissues determined by histopathology observations. CONCLUSION: Collectively, BCA treatment demonstrated the remarkable therapeutic effects on TGF-ß/BLM mediated pulmonary fibrosis using IPF cells and rodent models. This current study may offer a novel treatment approach to halt and may be even rescue the devastating lung scarring of IPF.

Pien Tze Huang accelerated wound healing by inhibition of abnormal fibroblast apoptosis in Streptozotocin induced diabetic mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Diabetic foot ulcer is one of the most serious complications of diabetes. Effective medical treatment regarding improvement of ulcer healing in patients is essential. Pien Tze Huang (PZH), a valuable Chinese traditional medicine, has been found significant efficacy on the curing of diabetic wound in clinic recently. AIM OF THE STUDY: This work was conducted to confirm the efficacy, and compare the therapeutic effect through the oral administration and local delivery route, providing a rationale for the new PZH form development; besides, the mechanisms through which PZH promoted the wound healing was also discussed. MATERIALS AND METHODS: First, the chemical composition of PZH was characterized by 1H-NMR and HPLC. The anti-apoptosis effects of PZH on high concentration glucose injured epidermal fibroblast (HFF-1) was investigated in a dose dependent way. Then, the effects of the systematical administration of PZH, and the topical used route on excisional wounds of Streptozotocin (STZ) induced diabetic mice were compared. RESULTS: The results illustrated that PZH decreased the reactive oxygen species (ROS) levels in cells, preventing cell damage/apoptosis through an ROS/Bcl-2/Bax/Caspase-3 pathway. The in vivo study proved that topical use of PZH exceeded the systematical route both in accelerating the wound closure and improving the healing quality. Meanwhile, PZH promoted wound closure through stimulating the secretion of Col-I, decreasing fibroblast apoptosis, and enhancing myo-fibroblast differentiation, in consistent with the mechanism study in vitro. CONCLUSIONS: Local used PZH improves wound healing by inhibiting the abnormal HFF-1 apoptosis and senescence. The study held a great promise for development of a topical dosage form of PZH for diabetic wound healing.

Antifibrotic Effects of the Thiazolidinediones in Eosinophilic Esophagitis Pathologic Remodeling: A Preclinical Evaluation.

INTRODUCTION: Eosinophilic esophagitis (EoE) is a T-helper 2 (Th2), eosinophilic disease associated with pathologic tissue remodeling that leads to end-organ dysfunction. During early-stage disease, inflammation and subepithelial fibrosis are coupled and reversible, but in late-stage or therapy-resistant disease, there can be uncoupling of these features with progressive esophageal rigidity and strictures contributing to clinical dysphagia and food impactions. No current pharmacotherapeutic interventions directly target esophageal fibrosis. Based on the ability of the thiazolidinediones (TZD) to regulate intestinal and hepatic fibrosis, we tested the antifibrotic effects of the TZDs, rosiglitazone and pioglitazone, in preclinical studies using primary human esophageal fibroblasts. METHODS: Primary fibroblasts isolated from normal or EoE esophagi were treated with transforming growth factor (TGF)-ß1 in the absence or presence of TZDs and, in some experiments, without or with budesonide and analyzed by quantitative real-time PCR and immunoblotting. Immunohistochemical analysis of human esophageal biopsies was performed. RESULTS: EoE esophageal biopsies and esophageal fibroblasts expressed higher levels of the TZD receptor, peroxisome proliferator-activated receptor-γ (PPAR-γ), than normal controls. PPAR-γ was inducible by the Th2 cytokine, interleukin 4 (IL-4). TZD significantly reduced TGF-ß1-induced myofibroblast and fibrotic gene and protein expression preferentially in EoE, but not normal esophageal fibroblasts. In esophageal fibroblasts, TGF-ß1 increased phosphorylated Smad2/3 and p38, but TZDs preferentially inhibited p38 phosphorylation, suggesting signaling pathway-specific effects. The TZDs were more potent than budesonide at decreasing collagen-1α1 expression. DISCUSSION: The TZDs preferentially exert antifibrotic effects in TGF-ß1-activated EoE fibroblasts and provide a preclinical foundation for further investigation of the potential of the TZDs in EoE pathologic remodeling.

Aesculus hippocastanum L. Extract Does Not Induce Fibroblast to Myofibroblast Conversion but Increases Extracellular Matrix Production In Vitro Leading to Increased Wound Tensile Strength in Rats.

The ability of horse chestnut extract (HCE) to induce contraction force in fibroblasts, a process with remarkable significance in skin repair, motivated us to evaluate its wound healing potential in a series of experiments. In the in vitro study of the ability of human dermal fibroblasts to form myofibroblast-like cells was evaluated at the protein level (Western blot and immunofluorescence). The in vivo study was conducted on male Sprague-Dawley rats with inflicted wounds (one open circular and one sutured incision) on their backs. Rats were topically treated with two tested HCE concentrations (0.1% and 1%) or sterile water. The control group remained untreated. The incisions were processed for wound tensile strength (TS) measurement whereas the open wounds were subjected to histological examination. On the in vitro level the HCE extract induced fibronectin-rich extracellular matrix formation, but did not induced α-smooth muscle actin (SMA) expression in dermal fibroblasts. The animal study revealed that HCE increased wound TS and improved collagen organization. In conclusion, the direct comparison of both basic wound models demonstrated that the healing was significantly increased following HCE, thus this extract may be found useful to improve healing of acute wounds. Nevertheless, the use of an experimental rat model warrants a direct extrapolation to the human clinical situation.

Curdione ameliorates bleomycin-induced pulmonary fibrosis by repressing TGF-ß-induced fibroblast to myofibroblast differentiation.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a progressive and irreversible disease characterized by excessive fibroblast to myofibroblast differentiation with limited therapeutic options. Curdione, a sesquiterpene compound extracted from the essential oil of Curcuma aromatica Salisb, has anti-inflammatory and anti-tumor effects. However, the role of curdione in IPF is still unclear. METHODS: The effects of curdione were evaluated in a bleomycin (BLM)-induced pulmonary fibrosis mouse model. C57BL/6 mice were treated with BLM on day 0 by intratracheal injection and intraperitoneal administered curdione or vehicle. In vitro study, expression of fibrotic protein was examined and the transforming growth factor (TGF)-ß-related signaling was evaluated in human pulmonary fibroblasts (HPFs) treated with curdione following TGF-ß1 stimulation. RESULTS: Histological and immunofluorescent examination showed that curdione alleviated BLM-induced lung injury and fibrosis. Specifically, curdione significantly attenuated fibroblast to myofibroblast differentiation in the lung in BLM induced mice. Furthermore, curdione also decreased TGF-ß1 induced fibroblast to myofibroblast differentiation in vitro, as evidenced by low expression of α-SMA, collagen 1 and fibronectin in a dose dependent manner. Mechanistically, curdione suppressed the phosphorylation of Smad3 following TGF-ß1 treatment, thereby inhibiting fibroblast differentiation. CONCLUSIONS: Overall, curdione exerted therapeutic effects against pulmonary fibrosis via attenuating fibroblast to myofibroblast differentiation. As curdione had been shown to be safe and well-tolerated in BLM-induced mouse model, curdione might be useful for developing novel therapeutics for IPF.

Andrographolide ameliorates bleomycin-induced pulmonary fibrosis by suppressing cell proliferation and myofibroblast differentiation of fibroblasts via the TGF-ß1-mediated Smad-dependent and -independent pathways.

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with no effective medication. Andrographolide (Andro), extracted from Chinese herbal Andrographis paniculata, could attenuate bleomycin (BLM)-induced pulmonary fibrosis via inhibition of inflammation and oxidative stress, however, the anti-fibrotic mechanisms have not been clarified. Myofibroblasts are the primary cell types responsible for the accumulation of extracellular matrix (ECM) in fibrotic diseases, and targeting fibroblast proliferation and differentiation is an important therapeutic strategy for the treatment of IPF. Hence, this study aimed to investigate the effects of Andro on the fibroblast proliferation and differentiation in the in vivo and in vitro models. The results showed that Andro improved pulmonary function and inhibited BLM-induced fibroblast proliferation and differentiation and ECM deposition in the lungs. In vitro, Andro inhibited proliferation and induced apoptosis of TGF-ß1-stimulated NIH 3T3 fibroblasts and primary lung fibroblasts (PLFs). Andro also inhibited TGF-ß1-induced myofibroblast differentiation and ECM deposition in both cells. We also found that Andro suppressed TGF-ß1-induced Smad2/3 and Erk1/2 activation, suggesting that Smad2/3 and Erk1/2 inactivation mediates Andro-induced effects on TGF-ß1-induced fibroblast proliferation and differentiation. These results indicated that Andro has novel and potent anti-fibrotic effects in lung fibroblasts via inhibition of the proliferation and myofibroblast differentiation of fibroblasts and subsequent ECM deposition, which are modulated by TGF-ß1-mediated Smad-dependent and -independent pathways.

Salvia miltiorrhiza Restrains Reactive Oxygen Species-Associated Pulmonary Fibrosis via Targeting Nrf2-Nox4 Redox Balance.

Pulmonary fibrosis (PF) is characterized by myofibroblast activation, which can be triggered by oxidative stress. In this study, we investigated the antifibrotic effect of the ethyl acetate extract of Salvia miltiorrhiza (EASM) on PF and examined the underlying molecular mechanism. EASM suppressed myofibroblast activation with reduced extracellular matrix deposition in the lungs of mice subjected to bleomycin (BLM) challenge, demonstrating the inhibitory effects on PF. EASM positively alleviated oxidative stress by upregulating nuclear factor-erythroid 2-related factor 2 (Nrf2) and concomitantly downregulating NADPH oxidase 4 (Nox4) in the lungs of BLM-treated mice. This effect was also observed in an in vitro model of transforming growth factor beta 1 (TGF-ß1)-stimulated fibroblast activation. EASM reduced reactive oxygen species (ROS) generation in fibroblasts by stabilizing Nrf2 protein with promoting kelch-like ECH-associated protein 1 (Keap1) degradation. Nrf2 knockdown in the lungs of BLM-treated mice diminished the inhibitory effects of EASM on fibrosis, providing evidence in vivo to address the unique role of Nrf2. Additionally, EASM inhibited TGF-ß1/Smad3 signaling by downregulating protein kinase C delta (PKC-δ) and Smad3 phosphorylation (p-Smad3), which led to suppression of the TGF-ß1-induced fibrogenic response. These results indicate that EASM exhibits potent antifibrotic activity in vitro and in vivo, which might be associated with activation of Nrf2 pathway and inhibition of TGF-ß1/Smad3 pathway. Our findings support that EASM may act as an effective antifibrotic remedy for PF.

Protocatechuic acid attenuates angiotensin II-induced cardiac fibrosis in cardiac fibroblasts through inhibiting the NOX4/ROS/p38 signaling pathway.

Cardiac fibrosis plays a crucial role in the pathogenesis of myocardial infarction (MI). It has been found that differentiation of cardiac fibroblasts (CFs) into myofibroblasts is a major event in the process of cardiac fibrosis. In the present study, we aimed to investigate the effects of protocatechuic acid (PCA), a cardiac protective agent, on the CFs differentiation in vitro. The results showed that PCA exhibited inhibitory effects on the cell proliferation and migration in angiotensin II (Ang II)-induced CFs. PCA treatment suppressed the Ang II-induced expression of α-smooth muscle actin (α-SMA), which is a hallmark of myofibroblasts. In addition, the production of extracellular matrix (ECM) proteins, including type I collagen (Col I) and connective tissue growth factor (CTGF), were significantly decreased in the PCA-treated CFs. The Ang II-induced increased levels of matrix metalloproteinase (MMP)-2, and MMP-9 were reduced by PCA. Furthermore, PCA resulted in decrease in reactive oxygen species (ROS) generation, as well as the expressions of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase enzyme 4 (NOX4) and p-p38 in Ang II-induced CFs. These findings showed that PCA treatment prevented the Ang II-induced cardiac fibrosis by inhibiting the NOX4/ROS/p38 signaling pathway in vitro, suggesting that PCA might be a therapeutic agent for MI.

Healing effect of andiroba-based emulsion in cutaneous wound healing via modulation of inflammation and transforming growth factor beta 31.

PURPOSE: To evaluate the effects and mechanisms of andiroba-based emulsion (ABE) topical treatment on full-thickness cutaneous wounds in rats. METHODS: The wounds were harvested on days 3, 7, 15, and 20 post-surgery. Wound contraction rate, quantitative immunohistochemistry [macrophages, myofibroblasts, capillaries, collagens (col) I and III, transforming growth factor ß3ß (TGFß3)], and tensile strength were assessed. RESULTS: Treated wounds were smaller, contracted earlier and had increased angiogenesis, fewer CD68+ and M2 macrophages on days 7 and 15, but higher on day 20. Myofibroblasts appeared on days 3 to 7 in untreated wounds and on days 7 to 15 in treated wounds. TGFß3 levels were higher in the treated wounds, less dense collagen fibers, lower col I/III ratios and a higher tensile strength. CONCLUSION: These results demonstrate the important anti-inflammatory role of treatment and the associated modulation of macrophages, myofibroblasts, and TGFß3 levels. Collagen fibers in the treated wounds were more organized and less dense, similar to unwounded skin, which likely contributed to the higher tensile strength.

Novel high-throughput myofibroblast assays identify agonists with therapeutic potential in pulmonary fibrosis that act via EP2 and EP4 receptors.

Pathological features of pulmonary fibrosis include accumulation of myofibroblasts and increased extracellular matrix (ECM) deposition in lung tissue. Contractile α-smooth muscle actin (α-SMA)-expressing myofibroblasts that produce and secrete ECM are key effector cells of the disease and therefore represent a viable target for potential novel anti-fibrotic treatments. We used primary normal human lung fibroblasts (NHLF) in two novel high-throughput screening assays to discover molecules that inhibit or revert fibroblast-to-myofibroblast differentiation. A phenotypic high-content assay (HCA) quantified the degree of myofibroblast differentiation, whereas an impedance-based assay, multiplexed with MS / MS quantification of α-SMA and collagen 1 alpha 1 (COL1) protein, provided a measure of contractility and ECM formation. The synthetic prostaglandin E1 (PGE1) alprostadil, which very effectively and potently attenuated and even reversed TGF-ß1-induced myofibroblast differentiation, was identified by screening a library of approved drugs. In TGF-ß1-induced myofibroblasts the effect of alprostadil was attributed to activation of prostanoid receptor 2 and 4 (EP2 and EP4, respectively). However, selective activation of the EP2 or the EP4 receptor was already sufficient to prevent or reverse TGF-ß1-induced NHLF myofibroblast transition. Our high-throughput assays identified chemical structures with potent anti-fibrotic properties acting through potentially novel mechanisms.

Healing effect of andiroba-based emulsion in cutaneous wound healing via modulation of inflammation and transforming growth factor beta 3

Abstract Purpose: To evaluate the effects and mechanisms of andiroba-based emulsion (ABE) topical treatment on full-thickness cutaneous wounds in rats. Methods: The wounds were harvested on days 3, 7, 15, and 20 post-surgery. Wound contraction rate, quantitative immunohistochemistry [macrophages, myofibroblasts, capillaries, collagens (col) I and III, transforming growth factor β3β (TGFβ3)], and tensile strength were assessed. Results: Treated wounds were smaller, contracted earlier and had increased angiogenesis, fewer CD68+ and M2 macrophages on days 7 and 15, but higher on day 20. Myofibroblasts appeared on days 3 to 7 in untreated wounds and on days 7 to 15 in treated wounds. TGFβ3 levels were higher in the treated wounds, less dense collagen fibers, lower col I/III ratios and a higher tensile strength. Conclusion: These results demonstrate the important anti-inflammatory role of treatment and the associated modulation of macrophages, myofibroblasts, and TGFβ3 levels. Collagen fibers in the treated wounds were more organized and less dense, similar to unwounded skin, which likely contributed to the higher tensile strength.