Antifibrotic Effect of Baicalin on Arecoline Induced Human Oral Fibroblast: An In-Vitro Study.

BACKGROUND: Baicalin is a flavonoid obtained from the Chinese herb Scutellaria baicalensis, which has a wide varieties of health benefits and scope to be studied for its therapeutic potential in oral fibrosis. AIM: The aim of the study was to investigate the antifibrotic effect of a Baicalin in arecoline induced human oral fibroblast in vitro setting. MATERIAL AND METHODS: Arecoline and ethanolic extracts of Baicalin were commercially purchased from Sigma-Aldrich. Human oral fibroblasts were cultured and characterized with specific fibroblast markers, and cells were stimulated with arecoline. An MTT assay (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) was executed to determine the half-maximal inhibitory concentration of arecoline and Baicalin. Arecoline-induced cells (25µg/ml) were treated with a non-toxic dose of Baicalin (proliferative dose of 25µg/ml). Cytokine (CCL2, CXCL-8, IL17, IL-beta, and IL-6) and fibrotic marker genes were studied by reverse transcription-polymerase chain reaction (RT-PCR). The inhibitory effect of Baicalin was studied to prove its antifibrotic properties. RESULTS: Arecoline significantly upregulated all inflammatory and fibrotic markers. On treatment with 25µg/ml of Baicalin, all inflammatory and fibrotic markers were inhibited. Arecoline affects fibroblast morphology, supporting the fact that arecoline is cytotoxic to cells. CONCLUSION: Baicalin can be used as an antifibrotic herb to treat OSMF.

Mimosa pudica L. extract ameliorates pulmonary fibrosis via modulation of MAPK signaling pathways and FOXO3 stabilization.

ETHNOPHARMACOLOGICAL RELEVANCE: Idiopathic pulmonary fibrosis (IPF) is a progressive fibrosing pulmonary disorder that has a poor prognosis and high mortality. Although there has been extensive effort to introduce several new anti-fibrotic agents in the past decade, IPF remains an incurable disease. Mimosa pudica L., an indigenous Vietnamese plant, has been empirically used to treat respiratory disorders. Nevertheless, the therapeutic effects of M. pudica (MP) on lung fibrosis and the mechanisms underlying those effects remain unclear. AIM OF THE STUDY: This study investigated the protective effect of a crude ethanol extract of the above-ground parts of MP against pulmonary fibrogenesis. MATERIALS AND METHODS: Inflammatory responses triggered by TNFα in structural lung cells were examined in normal human lung fibroblasts and A549 alveolar epithelial cells using Western blot analysis, reverse transcription-quantitative polymerase chain reaction assays, and immunocytochemistry. The epithelial-to-mesenchymal transition (EMT) was examined via cell morphology observations, F-actin fluorescent staining, gene and protein expression measurements, and a wound-healing assay. Anti-fibrotic assays including collagen release, differentiation, and measurements of fibrosis-related gene and protein expression levels were performed on TGFß-stimulated human lung fibroblasts and lung fibroblasts derived from mice with fibrotic lungs. Finally, in vitro anti-fibrotic activities were validated using a mouse model of bleomycin-induced pulmonary fibrosis. RESULTS: MP alleviated the inflammatory responses of A549 alveolar epithelial cells and lung fibroblasts, as revealed by inhibition of TNFα-induced chemotactic cytokine and chemokine expression, along with inactivation of the MAPK and NFκB signalling pathways. MP also partially reversed the TGFß-promoted EMT via downregulation of mesenchymal markers in A549 cells. Importantly, MP decreased the expression levels of fibrosis-related genes/proteins including collagen I, fibronectin, and αSMA; moreover, it suppressed collagen secretion and prevented myofibroblast differentiation in lung fibroblasts. These effects were mediated by FOXO3 stabilization through suppression of TGFß-induced ERK1/2 phosphorylation. MP consistently protected mice from the onset and progression of bleomycin-induced pulmonary fibrosis. CONCLUSION: This study explored the multifaceted roles of MP in counteracting the pathobiological processes of lung fibrosis. The results suggest that further evaluation of MP could yield candidate therapies for IPF.

FLECS technology for high-throughput screening of hypercontractile cellular phenotypes in fibrosis: A function-first approach to anti-fibrotic drug discovery.

The pivotal role of myofibroblast contractility in the pathophysiology of fibrosis is widely recognized, yet HTS approaches are not available to quantify this critically important function in drug discovery. We developed, validated, and scaled-up a HTS platform that quantifies contractile function of primary human lung myofibroblasts upon treatment with pro-fibrotic TGF-ß1. With the fully automated assay we screened a library of 40,000 novel small molecules in under 80 h of total assay run-time. We identified 42 hit compounds that inhibited the TGF-ß1-induced contractile phenotype of myofibroblasts, and enriched for 19 that specifically target myofibroblasts but not phenotypically related smooth muscle cells. Selected hits were validated in an ex vivo lung tissue models for their inhibitory effects on fibrotic gene upregulation by TGF-ß1. Our results demonstrate that integrating a functional contraction test into the drug screening process is key to identify compounds with targeted and diverse activity as potential anti-fibrotic agents.

[Research progress of anti-fibrotic drugs that inhibit epithelial-mesenchymal transition in pulmonary fibrosis].

Pulmonary fibrosis is the end-stage pathological change of lung diseases, which seriously affects the respiratory function of human body. A large number of studies at home and abroad have confirmed that epithelial-mesenchymal transition (EMT) is an important intermediate stage in the development of pulmonary fibrosis. Inhibition of multiple pathways upstream and downstream of EMT, such as the classical Smads pathway and non-Smads pathway of TGF-1 can effectively inhibit the process of EMT and alleviate pulmonary fibrosis. This article will review the main conclusions of the mechanism of action of EMT as a target to improve the pathology of pulmonary fibrosis so far, and provide a theoretical basis and research direction for further research and development of anti-pulmonary fibrosis drugs.

Tamoxifen Alters TGF-ß1/Smad Signaling in Vocal Fold Injury.

OBJECTIVES: Effective treatments for vocal fold fibrosis remain elusive. Tamoxifen (TAM) is a selective estrogen receptor modulator and was recently reported to have antifibrotic actions. We hypothesized that TAM inhibits vocal fold fibrosis via altered transforming growth factor beta 1 (TGF-ß1) signaling. Both in vitro and in vivo approaches were employed to address this hypothesis. METHODS: In vitro, vocal fold fibroblasts were treated with TAM (10-8 or 10-9 M) ± TGF-ß1 (10 ng/ml) to quantify cell proliferation. The effects of TAM on genes related to fibrosis were quantified via quantitative real-time polymerase chain reaction. In vivo, rat vocal folds were unilaterally injured, and TAM was administered by oral gavage from pre-injury day 5 to post-injury day 7. The rats were randomized into two groups: 0 mg/kg/day (sham) and 50 mg/kg/day (TAM). Histological changes were examined on day 56 to assess tissue architecture. RESULTS: TAM (10-8 M) did not affect Smad3, Smad7, Acta2, or genes related to extracellular matrix metabolism. TAM (10-8 or 10-9 M) + TGF-ß1, however, significantly increased Smad7 and Has3 expression and decreased Col1a1 and Acta2 expression compared to TGF-ß1 alone. In vivo, TAM significantly increased lamina propria area, hyaluronic acid concentration, and reduced collagen deposition compared to sham treatment. CONCLUSIONS: TAM has antifibrotic potential via the regulation of TGF-ß1/Smad signaling in vocal fold injury. These findings provide foundational data to develop innovative therapeutic options for vocal fold fibrosis. LEVEL OF EVIDENCE: NA Laryngoscope, 133:2248-2254, 2023.

Discovery and development of palmatine analogues as anti-NASH agents by activating farnesoid X receptor (FXR).

Sixty-one palmatine (PMT) derivatives, of which twenty-eight were new, were synthesized and evaluated for their anti-fibrogenic activities via collagen type I α 1 (COL1A1)-promoter based luciferase model in LX-2 cells, taking 2,3,10-trimethoxy-9-p-isopropyloxyprotopalmatine bromide (1) as the lead. Among them, compound 3a exerted the highest potency with the IC50 value of 8.19 µmol/L and SI value of 8.59, and reduced the expressions of multiple fibrogenic biomarkers, including COL1A1, TGF-ß1, α-SMA and TIMP1 in a dose-dependent manner. In addition, it significantly reduced liver steatosis and inflammation, and especially attenuated the degree of liver fibrosis in choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD)-induced NASH mice model in vivo. Mechanism study indicated that it significantly ameliorated liver injury by activating farnesoid X receptor (FXR). BDL-induced fibrosis rats model further verified its liver-protective and anti-fibrosis activities. Therefore, PMT derivatives constituted a new family of non-steroidal FXR agonists as anti-NASH candidates, with the advantage of good safety profile, and are worthy for further investigation.

Kasugamycin Is a Novel Chitinase 1 Inhibitor with Strong Antifibrotic Effects on Pulmonary Fibrosis.

Pulmonary fibrosis is a devastating lung disease with few therapeutic options. CHIT1 (chitinase 1), an 18 glycosyl hydrolase family member, contributes to the pathogenesis of pulmonary fibrosis through the regulation of TGF-ß (transforming growth factor-ß) signaling and effector function. Therefore, CHIT1 is a potential therapeutic target for pulmonary fibrosis. This study aimed to identify and characterize a druggable CHIT1 inhibitor with strong antifibrotic activity and minimal toxicity for therapeutic application to pulmonary fibrosis. Extensive screening of small molecule libraries identified the aminoglycoside antibiotic kasugamycin (KSM) as a potent CHIT1 inhibitor. Elevated concentrations of CHIT1 were detected in the lungs of patients with pulmonary fibrosis. In in vivo bleomycin- and TGF-ß-stimulated murine models of pulmonary fibrosis, KSM showed impressive antifibrotic effects in both preventive and therapeutic conditions. In vitro studies also demonstrated that KSM inhibits fibrotic macrophage activation, fibroblast proliferation, and myofibroblast transformation. Null mutation of TGFBRAP1 (TGF-ß-associated protein 1), a recently identified CHIT1 interacting signaling molecule, phenocopied antifibrotic effects of KSM in in vivo lungs and in vitro fibroblasts responses. KSM inhibits the physical association between CHIT1 and TGFBRAP1, suggesting that the antifibrotic effect of KSM is mediated through regulation of TGFBRAP1, at least in part. These studies demonstrate that KSM is a novel CHIT1 inhibitor with a strong antifibrotic effect that can be further developed as an effective and safe therapeutic drug for pulmonary fibrosis.

Integrated bioinformatics analysis identifies established and novel TGFß1-regulated genes modulated by anti-fibrotic drugs.

Fibrosis is a leading cause of morbidity and mortality worldwide. Although fibrosis may involve different organ systems, transforming growth factor-ß (TGFß) has been established as a master regulator of fibrosis across organs. Pirfenidone and Nintedanib are the only currently-approved drugs to treat fibrosis, specifically idiopathic pulmonary fibrosis, but their mechanisms of action remain poorly understood. To identify novel drug targets and uncover potential mechanisms by which these drugs attenuate fibrosis, we performed an integrative 'omics analysis of transcriptomic and proteomic responses to TGFß1-stimulated lung fibroblasts. Significant findings were annotated as associated with pirfenidone and nintedanib treatment in silico via Coremine. Integrative 'omics identified a co-expressed transcriptomic and proteomic module significantly correlated with TGFß1 treatment that was enriched (FDR-p = 0.04) with genes associated with pirfenidone and nintedanib treatment. While a subset of genes in this module have been implicated in fibrogenesis, several novel TGFß1 signaling targets were identified. Specifically, four genes (BASP1, HSD17B6, CDH11, and TNS1) have been associated with pirfenidone, while five genes (CLINT1, CADM1, MTDH, SYDE1, and MCTS1) have been associated with nintedanib, and MYDGF has been implicated with treatment using both drugs. Using the Clue Drug Repurposing Hub, succinic acid was highlighted as a metabolite regulated by the protein encoded by HSD17B6. This study provides new insights into the anti-fibrotic actions of pirfenidone and nintedanib and identifies novel targets for future mechanistic studies.

Nifuroxazide-loaded cubosomes exhibit an advancement in pulmonary delivery and attenuate bleomycin-induced lung fibrosis by regulating the STAT3 and NF-κB signaling: A new challenge for unmet therapeutic needs.

Pulmonary fibrosis (PF) is a chronic progressive disease that portends a very poor prognosis. It has been suggested that STAT3 is a potential target in PF. This study highlights the importance of cubosomes as a drug delivery system in enhancing the bioavailability of nifuroxazide (NXZD), a poorly soluble STAT3 inhibitor. NXZD-loaded cubosomes (NXZD-LC) were in vitro and in vivo evaluated. In vitro, cubosomes presented a poly-angular nanosized particles with a mean size and zeta potential of 223.73 ± 4.73 nm and - 20.93 ± 2.38 mV, respectively. The entrapment efficiency of nifuroxazide was 90.56 ± 4.25%. The in vivo pharmacokinetic study and the lung tissue accumulation of NXZD were performed by liquid chromatography-tandem mass spectrometry after oral administration to rats. The nanoparticles exhibited a two-fold increase and 1.33 times of bioavailability and lung tissue concentration of NXZD compared to NXZD dispersion, respectively. In view of this, NXZD-LC effectively attenuated PF by targeting STAT3 and NF-κB signals. As a result, NXZD-LC showed a potential anti-inflammatory effect as revealed by the significant decrease in MCP-1, ICAM-1, IL-6, and TNF-α and suppressed fibrogenic mediators as indicated by the significant reduction in TGF-ß, TIMP-1, and PDGF-BB in lung tissues. Besides, NXZD-LC improved antioxidant defense mechanisms and decreased LDH and BALF total protein. These effects contributed to decreased collagen deposition. To conclude, cubosomes represent an advantageous pharmaceutical delivery system for enhancing pulmonary delivery of poorly soluble drugs. Additionally, repurposing NXZD as an antifibrotic agent is a promising challenge and new therapeutic approach for unmet therapeutic needs.

Transcriptomic analysis of choroidal neovascularization reveals dysregulation of immune and fibrosis pathways that are attenuated by a novel anti-fibrotic treatment.

Neovascular AMD (nAMD) leads to vision loss and is a leading cause of visual impairment in the industrialised world. Current treatments that target blood vessel growth have not been able to treat subretinal fibrosis and nAMD patients continue to lose vision. The molecular mechanisms involved in the development of fibrotic lesions in nAMD are not well understood. The aim of this study was to further understand subretinal fibrosis in the laser photocoagulation model of choroidal neovascularization (CNV) by studying the whole transcriptome of the RPE/choroid following CNV and the application of an anti-fibrotic following CNV. Seven days after laser induced CNV, RPE and choroid tissue was separated and underwent RNAseq. Differential expression analysis and pathway analysis revealed an over representation of immune signalling and fibrotic associated pathways in CNV compared to control RPE/choroid tissue. Comparisons between the mouse CNV model to human CNV revealed an overlap in upregulated expression for immune genes (Ccl2, Ccl8 and Cxcl9) and extracellular matrix remodeling genes (Comp, Lrcc15, Fndc1 and Thbs2). Comparisons between the CNV model and other fibrosis models showed an overlap of over 60% of genes upregulated in either lung or kidney mouse models of fibrosis. Treatment of CNV using a novel cinnamoyl anthranilate anti-fibrotic (OCX063) in the laser induced CNV model was selected as this class of drugs have previously been shown to target fibrosis. CNV lesion leakage and fibrosis was found to be reduced using OCX063 and gene expression of genes within the TGF-beta signalling pathway. Our findings show the presence of fibrosis gene expression pathways present in the laser induced CNV mouse model and that anti-fibrotic treatments offer the potential to reduce subretinal fibrosis in AMD.

Discovery of Potent and Selective 2-(Benzylthio)pyrimidine-based DCN1-UBC12 Inhibitors for Anticardiac Fibrotic Effects.

DCN1, a co-E3 ligase, interacts with UBC12 and activates cullin-RING ligases (CRLs) by catalyzing cullin neddylation. Although DCN1 has been recognized as an important therapeutic target for human diseases, its role in the cardiovascular area remains unknown. Here, we first found that DCN1 was upregulated in isolated cardiac fibroblasts (CFs) treated by angiotensin (Ang) II and in mouse hearts after pressure overload. Then, structure-based optimizations for DCN1-UBC12 inhibitors were performed based on our previous work, yielding compound DN-2. DN-2 specifically targeted DCN1 at molecular and cellular levels as shown by molecular modeling studies, HTRF, cellular thermal shift and co-immunoprecipitation assays. Importantly, DN-2 effectively reversed Ang II-induced cardiac fibroblast activation, which was associated with the inhibition of cullin 3 neddylation. Our findings indicate a potentially unrecognized role of DCN1 inhibition for anticardiac fibrotic effects. DN-2 may be used as a lead compound for further development.

Relaxin as an anti-fibrotic treatment: Perspectives, challenges and future directions.

Fibrosis refers to the scarring and hardening of tissues, which results from a failed immune system-coordinated wound healing response to chronic organ injury and which manifests from the aberrant accumulation of various extracellular matrix components (ECM), primarily collagen. Despite being a hallmark of prolonged tissue damage and related dysfunction, and commonly associated with high morbidity and mortality, there are currently no effective cures for its regression. An emerging therapy that meets several criteria of an effective anti-fibrotic treatment, is the recombinant drug-based form of the human hormone, relaxin (also referred to as serelaxin, which is bioactive in several other species). This review outlines the broad anti-fibrotic and related organ-protective roles of relaxin, mainly from studies conducted in preclinical models of ageing and fibrotic disease, including its ability to ameliorate several aspects of fibrosis progression and maturation, from immune cell infiltration, pro-inflammatory and pro-fibrotic cytokine secretion, oxidative stress, organ hypertrophy, cell apoptosis, myofibroblast differentiation and ECM production, to its ability to facilitate established ECM degradation. Studies that have compared and/or combined these therapeutic effects of relaxin with current standard of care medication have also been discussed, along with the main challenges that have hindered the translation of the anti-fibrotic efficacy of relaxin to the clinic. The review then outlines the future directions as to where scientists and several pharmaceutical companies that have recognized the therapeutic potential of relaxin are working towards, to progress its development as a treatment for human patients suffering from various fibrotic diseases.

Dihydrotestosterone through blockade of TGF-ß/Smad signaling mediates the anti-fibrosis effect under hypoxia in canine Sertoli cells.

The hypoxic microenvironment of cryptorchidism is an important factor to induce the impairment of the structure and function of Sertoli cells and thus lead to spermatogenesis loss or tumorigenesis. Dihydrotestosterone (DHT), as a potent nonaromatizable 5α-reduced androgen, has both positive and negative effect on pathological fibrosis process. However, it is still unknown whether DHT can regulate hypoxia-induced fibrosis of Sertoli cells. Herein, in this study, we evaluate the DHT level, two 5α-reductase isoforms, 5α-red1 and 5α-red2, as well as HIF-1α expression pattern in canine cryptorchidism and contralateral normal testis. Results showed that the abdominal testes presented low DHT levels and 5α-red1 and 5α-red2 expression, while significantly higher HIF-1α expression and ECM production compared with the scrotum. Moreover, we established a hypoxia-induced fibrosis model in canine Sertoli cells induced by cobalt chloride (CoCl2), and found that DHT inhibited the fibrosis of Sertoli cells in a dose-dependent manner. Meanwhile, DHT interfered with the TGF-ß signaling by reducing the expression of TGF-ßRI and TGF-ßRII and inhibiting the expression and phosphorylation of Smad2 and Smad3, while flutamide (androgen receptor inhibitor) inhibited these effects of DHT. Furthermore, use of LY2109761 (TGF-ß receptor type I/II inhibitor) to interfere with the TGF-ß/Smad pathway showed a similar effect with DHT suppression of the fibrosis in Sertoli cells. Our research data demonstrated that cryptorchidism is located in a hypoxic and DHT deficiency microenvironment. Moreover, supplementing DHT can alleviate the fibrosis process of Sertoli cells caused by hypoxia, which is associated with AR regulating the inhibition of TGF-ß/Smad signaling.

Synthesis and in vitro evaluation of anti-inflammatory, antioxidant, and anti-fibrotic effects of new 8-aminopurine-2,6-dione-based phosphodiesterase inhibitors as promising anti-asthmatic agents.

Phosphodiesterase (PDE) inhibitors are currently an extensively studied group of compounds that can bring many benefits in the treatment of various inflammatory and fibrotic diseases, including asthma. Herein, we describe a series of novel N'-phenyl- or N'-benzylbutanamide and N'-arylidenebutanehydrazide derivatives of 8-aminopurine-2,6-dione (27-43) and characterized them as prominent pan-PDE inhibitors. Most of the compounds exhibited antioxidant and anti-inflammatory activity in lipopolysaccharide (LPS)-induced murine macrophages RAW264.7. The most active compounds (32-35 and 38) were evaluated in human bronchial epithelial cells (HBECs) derived from asthmatics. To better map the bronchial microenvironment in asthma, HBECs after exposure to selected 8-aminopurine-2,6-dione derivatives were incubated in the presence of two proinflammatory and/or profibrotic factors: transforming growth factor type ß (TGF-ß) and interleukin 13 (IL-13). Compounds 32-35 and 38 significantly reduced both IL-13- and TGF-ß-induced expression of proinflammatory and profibrotic mediators, respectively. Detailed analysis of their inhibition preferences for selected PDEs showed high affinity for isoenzymes important in the pathogenesis of asthma, including PDE1, PDE3, PDE4, PDE7, and PDE8. The presented data confirm that structural modifications within the 7 and 8 positions of the purine-2,6-dione core result in obtaining preferable pan-PDE inhibitors which in turn exert an excellent anti-inflammatory and anti-fibrotic effect in the bronchial epithelial cells derived from asthmatic patients. This dual-acting pan-PDE inhibitors constitute interesting and promising lead structures for further anti-asthmatic agent discovery.

Resveratrol against Cardiac Fibrosis: Research Progress in Experimental Animal Models.

Cardiac fibrosis is a heterogeneous disease, which is characterized by abundant proliferation of interstitial collagen, disordered arrangement, collagen network reconstruction, increased cardiac stiffness, and decreased systolic and diastolic functions, consequently developing into cardiac insufficiency. With several factors participating in and regulating the occurrence and development of cardiac fibrosis, a complex molecular mechanism underlies the disease. Moreover, cardiac fibrosis is closely related to hypertension, myocardial infarction, viral myocarditis, atherosclerosis, and diabetes, which can lead to serious complications such as heart failure, arrhythmia, and sudden cardiac death, thus seriously threatening human life and health. Resveratrol, with the chemical name 3,5,4'-trihydroxy-trans-stilbene, is a polyphenol abundantly present in grapes and red wine. It is known to prevent the occurrence and development of cardiovascular diseases. In addition, it may resist cardiac fibrosis through a variety of growth factors, cytokines, and several cell signaling pathways, thus exerting a protective effect on the heart.

Schisandrin B Attenuates Hepatic Stellate Cell Activation and Promotes Apoptosis to Protect against Liver Fibrosis.

The activation of hepatic stellate cells (HSC) plays a key role in the progression of hepatic fibrosis, it is essential to remove activated HSC through apoptosis to reverse hepatic fibrosis. Schisandrin B (Sch B) is the main chemical component of schisandrin lignan, and it has been reported to have good hepatoprotective effects. However, Schisandrin B on HSC apoptosis remains unclear. In our study, we stimulated the HSC-T6 and LX-2 cell lines with TGF-ß1 to induce cell activation, and the proliferation and apoptosis of the activated HSC-T6 and LX-2 cells were detected after treatment with different doses of Schisandrin B. Flow cytometry results showed that Sch B significantly reduced the activity of activated HSC-T6 and LX-2 cells and significantly induced apoptosis. In addition, the cleaved-Caspase-3 levels were increased, the Bax activity was increased, and the Bcl-2 expression was decreased in HSC-T6 and LX-2 cells treated with Sch B. Our study showed that Sch B inhibited the TGF-ß1-induced activity of hepatic stellate cells by promoting apoptosis.

Up-regulation of Nrf2/P62/Keap1 involves in the anti-fibrotic effect of combination of monoammonium glycyrrhizinate and cysteine hydrochloride induced by CCl4.

Combination of monoammonium glycyrrhizinate and cysteine hydrochloride (MG-CH) has been used in the treatment of chronic liver disease for decades, however, its mechanism is still unclear. Our previous studies showed that MG-CH confers the optimal therapeutic effect at the ratio of 2:1 to against acute liver damage. In this study, it was used to investigate the anti-fibrotic effect induced by CCl4. The results showed that injection of MG-CH produced anti-fibrotic effect ranged from 30 mg/kg to 60 mg/kg, evidenced by decreased the collagens deposition and inhibited the production of hydroxyproline. Mechanism study found that Nrf2/ARE signaling pathway was activated by MG-CH, whereas loss of hepatocytic Nrf2 abolished its anti-fibrotic effect significantly. Furthermore, it was demonstrated that MG-CH is a non-canonical NRF2 inducer, which promoted the autophagy activity and release the Nrf2 from keap 1 by promoting the phosphorylation of p62 at Ser351. Knockdown of p62 abolished the enhancement of nuclear accumulation of Nrf2 by MG-CH. All of these results suggested that up-regulation of Nrf2/P62/Keap1 involves in the anti-fibrotic effect of MG-CH, which provide a rational explanation for the usage of MG-CH in the treatment of fibrosis.

Pharmacological characterisation of GSK3335103, an oral αvß6 integrin small molecule RGD-mimetic inhibitor for the treatment of fibrotic disease.

Fibrosis is the formation of scar tissue due to injury or long-term inflammation and is a leading cause of morbidity and mortality. Activation of the pro-fibrotic cytokine transforming growth factor-ß (TGFß) via the alpha-V beta-6 (αvß6) integrin has been identified as playing a key role in the development of fibrosis. Therefore, a drug discovery programme to identify an orally bioavailable small molecule αvß6 arginyl-glycinyl-aspartic acid (RGD)-mimetic was initiated. As part of a medicinal chemistry programme GSK3335103 was identified and profiled in a range of pre-clinical in vitro and in vivo systems. GSK3335103 was shown to bind to the αvß6 with high affinity and demonstrated fast binding kinetics. In primary human lung epithelial cells, GSK3335103-induced concentration- and time-dependent internalisation of αvß6 with a rapid return of integrin to the cell surface observed after washout. Following sustained engagement of the αvß6 integrin in vitro, lysosomal degradation was induced by GSK3335103. GSK3335103 was shown to engage with the αvß6 integrin and inhibit the activation of TGFß in both ex vivo IPF tissue and in a murine model of bleomycin-induced lung fibrosis, as measured by αvß6 engagement, TGFß signalling and collagen deposition, with a prolonged duration of action observed in vivo. In summary, GSK3335103 is a potent αvß6 inhibitor that attenuates TGFß signalling in vitro and in vivo with a well-defined pharmacokinetic/pharmacodynamic relationship. This translates to a significant reduction of collagen deposition in vivo and therefore GSK3335103 represents a potential novel oral therapy for fibrotic disorders.