NP603, a novel and potent inhibitor of FGFR1 tyrosine kinase, inhibits hepatic stellate cell proliferation and ameliorates hepatic fibrosis in rats

IFNγ-IL12 axis regulates intercellular crosstalk in metabolic dysfunction-associated steatotic liver disease

Obesity is a major cause of metabolic dysfunction-associated steatohepatitis (MASH) and is characterized by inflammation and insulin resistance. Interferon-γ (IFNγ) is a pro-inflammatory cytokine elevated in obesity and modulating macrophage functions. Here, we show that male mice with loss of IFNγ signaling in myeloid cells (Lyz-IFNγR2-/-) are protected from diet-induced insulin resistance despite fatty liver. Obesity-mediated liver inflammation is also attenuated with reduced interleukin (IL)-12, a cytokine primarily released by macrophages, and IL-12 treatment in vivo causes insulin resistance by impairing hepatic insulin signaling. Following MASH diets, Lyz-IFNγR2-/- mice are rescued from developing liver fibrosis, which is associated with reduced fibroblast growth factor (FGF) 21 levels. These results indicate critical roles for IFNγ signaling in macrophages and their release of IL-12 in modulating obesity-mediated insulin resistance and fatty liver progression to MASH. In this work, we identify the IFNγ-IL12 axis in regulating intercellular crosstalk in the liver and as potential therapeutic targets to treat MASH.

An oral phenylacrylic acid derivative suppressed hepatic stellate cell activation and ameliorated liver fibrosis by blocking TGF-β1 signalling

BACKGROUND AND AIMS

Liver fibrosis is an excessive wound-healing response governed by activated hepatic stellate cells (HSCs). To date, there is no drug available for liver fibrosis. Although ferulic acid (FA) has multiple pharmacological functions, its anti-hepatic fibrosis activity is weak. Based on the activity modification of the FA structure, we synthesized a series of phenylacrylic derivatives and found a superior compound, FA11. In this study, we investigated its antifibrotic effect and mechanism.

METHODS

Activated HSC and CCl₄ -induced mouse liver fibrosis were established and followed by FA11 treatment. Cell viability was measured by CCK-8 assay. Apoptosis and cell cycle analysis were conducted by flow cytometry. Western blot and Real-time qPCR were used to examine the expression of fibrotic and M1/M2-type macrophages markers. Degree of liver fibrosis was shown by histological staining.

RESULTS

In vitro, FA11 inhibited TGF-β1-induced LX-2 proliferation and led to apoptosis and cycle arrest. Furthermore, elevation of fibrotic markers in TGF-β1-induced LX-2 and primary activated HSC was reversed by FA11. In vivo, FA11 administration alleviated collagen deposition and blocked HSC activation and epithelial-mesenchymal transition (EMT). Additionally, FA11 reduced macrophage infiltration in fibrotic liver and prevented macrophage polarization to a profibrotic phenotype. Meanwhile, the systemic toxicity of CCl₄ was also ameliorated by FA11. Mechanistically, FA11 reversed the phosphorylation of canonical and noncanonical TGF-β1 signalling, as well as FGFR1 signalling.

CONCLUSIONS

We reported an oral phenylacrylic acid derivative, FA11, which showed excellent antifibrotic activity and was expected to be an anti-hepatic fibrosis candidate.

A single-nucleus and spatial transcriptomic atlas of the COVID-19 liver reveals topological, functional, and regenerative organ disruption in patients

The molecular underpinnings of organ dysfunction in acute COVID-19 and its potential long-term sequelae are under intense investigation. To shed light on these in the context of liver function, we performed single-nucleus RNA-seq and spatial transcriptomic profiling of livers from 17 COVID-19 decedents. We identified hepatocytes positive for SARS-CoV-2 RNA with an expression phenotype resembling infected lung epithelial cells. Integrated analysis and comparisons with healthy controls revealed extensive changes in the cellular composition and expression states in COVID-19 liver, reflecting hepatocellular injury, ductular reaction, pathologic vascular expansion, and fibrogenesis. We also observed Kupffer cell proliferation and erythrocyte progenitors for the first time in a human liver single-cell atlas, resembling similar responses in liver injury in mice and in sepsis, respectively. Despite the absence of a clinical acute liver injury phenotype, endothelial cell composition was dramatically impacted in COVID-19, concomitantly with extensive alterations and profibrogenic activation of reactive cholangiocytes and mesenchymal cells. Our atlas provides novel insights into liver physiology and pathology in COVID-19 and forms a foundational resource for its investigation and understanding.

Targeting FAPα-expressing hepatic stellate cells overcomes resistance to antiangiogenics in colorectal cancer liver metastasis models

Vessel co-option has been demonstrated to mediate colorectal cancer liver metastasis (CRCLM) resistance to antiangiogenic therapy. The current mechanisms underlying vessel co-option have mainly focused on "hijacker" tumor cells, whereas the function of the "hijackee" sinusoidal blood vessels has not been explored. Here, we found that the occurrence of vessel co-option in bevacizumab-resistant CRCLM xenografts was associated with increased expression of fibroblast activation protein α (FAPα) in the co-opted hepatic stellate cells (HSCs), which was dramatically attenuated in HSC-specific conditional Fap-knockout mice bearing CRCLM allografts. Mechanistically, bevacizumab treatment induced hypoxia to upregulate the expression of fibroblast growth factor-binding protein 1 (FGFBP1) in tumor cells. Gain- or loss-of-function experiments revealed that the bevacizumab-resistant tumor cell-derived FGFBP1 induced FAPα expression by enhancing the paracrine FGF2/FGFR1/ERK1/-2/EGR1 signaling pathway in HSCs. FAPα promoted CXCL5 secretion in HSCs, which activated CXCR2 to promote the epithelial-mesenchymal transition of tumor cells and the recruitment of myeloid-derived suppressor cells. These findings were further validated in tumor tissues derived from patients with CRCLM. Targeting FAPα+ HSCs effectively disrupted the co-opted sinusoidal blood vessels and overcame bevacizumab resistance. Our study highlights the role of FAPα+ HSCs in vessel co-option and provides an effective strategy to overcome the vessel co-option-mediated bevacizumab resistance.

Emerging therapeutic potential of adeno-associated virus-mediated gene therapy in liver fibrosis

Liver fibrosis is a wound-healing response that results from various chronic damages. If the causes of damage are not removed or effective treatments are not given in a timely manner, it will progress to cirrhosis, even liver cancer. Currently, there are no specific medical therapies for liver fibrosis. Adeno-associated virus (AAV)-mediated gene therapy, one of the frontiers of modern medicine, has gained more attention in many fields due to its high safety profile, low immunogenicity, long-term efficacy in mediating gene expression, and increasingly known tropism. Notably, increasing evidence suggests a promising therapeutic potential for AAV-mediated gene therapy in different liver fibrosis models, which helps to correct abnormally changed target genes in the process of fibrosis and improve liver fibrosis at the molecular level. Moreover, the addition of cell-specific promoters to the genome of recombinant AAV helps to limit gene expression in specific cells, thereby producing better therapeutic efficacy in liver fibrosis. However, animal models are considered to be powerless predictive of tissue tropism, immunogenicity, and genotoxic risks in humans. Thus, AAV-mediated gene therapy will face many challenges. This review systemically summarizes the recent advances of AAV-mediated gene therapy in liver fibrosis, especially focusing on cellular and molecular mechanisms of transferred genes, and presents prospective challenges.

Exploring the Gamut of Receptor Tyrosine Kinases for Their Promise in the Management of Non-Alcoholic Fatty Liver Disease

Recently, non-alcoholic fatty liver disease (NAFLD) has emerged as a predominant health concern affecting approximately a quarter of the world’s population. NAFLD is a spectrum of liver ailments arising from nascent lipid accumulation and leading to inflammation, fibrosis or even carcinogenesis. Despite its prevalence and severity, no targeted pharmacological intervention is approved to date. Thus, it is imperative to identify suitable drug targets critical to the development and progression of NAFLD. In this quest, a ray of hope is nestled within a group of proteins, receptor tyrosine kinases (RTKs), as targets to contain or even reverse NAFLD. RTKs control numerous vital biological processes and their selective expression and activity in specific diseases have rendered them useful as drug targets. In this review, we discuss the recent advancements in characterizing the role of RTKs in NAFLD progression and qualify their suitability as pharmacological targets. Available data suggests inhibition of Epidermal Growth Factor Receptor, AXL, Fibroblast Growth Factor Receptor 4 and Vascular Endothelial Growth Factor Receptor, and activation of cellular mesenchymal-epithelial transition factor and Fibroblast Growth Factor Receptor 1 could pave the way for novel NAFLD therapeutics. Thus, it is important to characterize these RTKs for target validation and proof-of-concept through clinical trials.

Therapeutic and diagnostic targeting of fibrosis in metabolic, proliferative and viral disorders

Fibrosis is a common denominator in many pathologies and crucially affects disease progression, drug delivery efficiency and therapy outcome. We here summarize therapeutic and diagnostic strategies for fibrosis targeting in atherosclerosis and cardiac disease, cancer, diabetes, liver diseases and viral infections. We address various anti-fibrotic targets, ranging from cells and genes to metabolites and proteins, primarily focusing on fibrosis-promoting features that are conserved among the different diseases. We discuss how anti-fibrotic therapies have progressed over the years, and how nanomedicine formulations can potentiate anti-fibrotic treatment efficacy. From a diagnostic point of view, we discuss how medical imaging can be employed to facilitate the diagnosis, staging and treatment monitoring of fibrotic disorders. Altogether, this comprehensive overview serves as a basis for developing individualized and improved treatment strategies for patients suffering from fibrosis-associated pathologies.

A novel multikinase inhibitor SKLB-YTH-60 ameliorates inflammation and fibrosis in bleomycin-induced lung fibrosis mouse models

OBJECTIVES

Idiopathic pulmonary fibrosis (IPF) is marked by the excessive accumulation of extracellular matrix, which participates in a variety of chronic diseases or injuries and seriously threatens human health. Due to the side effects of clinical drugs, there is still a need to develop novel and less toxic drugs to treat pulmonary fibrosis.

MATERIALS AND METHODS

SKLB-YTH-60 was developed through computer-aided drug design, de novo synthesis and high-throughput screening. We employed the bleomycin (BLM)-induced lung fibrosis animal models and used TGF-β₁ to induce the epithelial-mesenchymal transition (EMT) of A549 cells in vitro. Meanwhile, the protein expression of collagen I and the α-smooth muscle actin (α-SMA), E-cadherin, p-FGFR1, p-PLCγ, p-Smad2/3 and p-Erk1/2 was detected by western blot.

RESULTS

YTH-60 has obvious anti-proliferative activity on fibroblasts and A549 cells. Moreover, YTH-60 could impair the EMT of A549 cells and suppressed fibrosis by inhibiting FGFR and TGF-β/Smad-dependent pathways. Intraperitoneal administration of preventive YTH-60 could significantly reduce the degree of fibrosis in mice and regulate the imbalance of the immune microenvironment. In addition, we observed that therapeutic YTH-60 treatment attenuated fibrotic changes in mice during the period of fibrosis. Importantly, YTH-60 has shown an acceptable oral bioavailability (F = 17.86%) and appropriate eliminated half-life time (T_1/2  = 8.03 hours).

CONCLUSIONS

Taken together, these preclinical evaluations suggested that YTH-60 could be a promising drug candidate for treating IPF.

Role of fibroblast growth factor signalling in hepatic fibrosis

Fibrotic remodelling is a highly conserved protective response to tissue injury and it is essential for the maintenance of structural and functional tissue integrity. Also hepatic fibrosis can be considered as a wound-healing response to liver injury, reflecting a balance between liver repair and scar formation. In contrast, pathological fibrosis corresponds to impaired wound healing. Usually, the liver regenerates after acute injury. However, if the damaging mechanisms persist, the liver reacts with progressive and uncontrolled accumulation of extracellular matrix proteins. Eventually, excessive fibrosis can lead to cirrhosis and hepatic failure. Furthermore, cirrhosis is the major risk factor for the development of hepatocellular cancer (HCC). Therefore, hepatic fibrosis is the most critical pathological factor that determines the morbidity and mortality of patients with chronic liver disease. Still, no effective anti-fibrogenic therapies exist, despite the very high medical need. The regulation of fibroblast growth factor (FGF) signalling is a prerequisite for adequate wound healing, repair and homeostasis in various tissues and organs. The FGF family comprises 22 proteins that can be classified into paracrine, intracrine and endocrine factors. Most FGFs signal through transmembrane tyrosine kinase FGF receptors (FGFRs). Although FGFRs are promising targets for the treatment of HCC, the expression and function of FGFR-ligands in hepatic fibrosis is still poorly understood. This review summarizes the latest advances in our understanding of FGF signalling in hepatic fibrosis. Furthermore, the potential of FGFs as targets for the treatment of hepatic fibrosis and remaining challenges for the field are discussed.

Lenvatinib prevents liver fibrosis by inhibiting hepatic stellate cell activation and sinusoidal capillarization in experimental liver fibrosis

Molecular targeted agents are pharmacologically used to treat liver fibrosis and have gained increased attention. The present study examined the preventive effect of lenvatinib on experimental liver fibrosis and sinusoidal capillarization as well as the in vitro phenotypes of hepatic stellate cells. LX-2, a human stellate cell line, was used for in vitro studies. In vivo liver fibrosis was induced in F344 rats using carbon tetrachloride by intraperitoneal injection for 8 weeks, and oral administration of lenvatinib was started two weeks after initial injection of carbon tetrachloride. Lenvatinib restrained proliferation and promoted apoptosis of LX-2 with suppressed phosphorylation of extracellular signal-regulated kinase 1/2 and AKT. It also down-regulated COL1A1, ACTA2 and TGFB1 expressions by inhibiting the transforming growth factor-β1/Smad2/3 pathway. Treatment with lenvatinib also suppressed platelet-derived growth factor-BB-stimulated proliferation, chemotaxis and vascular endothelial growth factor-A production, as well as basic fibroblast growth factor-induced LX-2 proliferation. In vivo study showed that lenvatinib attenuated liver fibrosis development with reduction in activated hepatic stellate cells and mRNA expression of profibrogenic markers. Intrahepatic neovascularization was ameliorated with reduced hepatic expressions of Vegf1, Vegf2 and Vegfa in lenvatinib-treated rats. Collectively, these results suggest the potential use of lenvatinib as a novel therapeutic strategy for liver fibrosis.

Force dependent effects of chronic overuse on fibrosis-related genes and proteins in skeletal muscles

AIM

To examine the chronic effect of force on mRNA and protein expression levels of fibrosis-related genes in flexor digitorum muscles in a rat model of repetitive overuse injury that induces muscle fibrosis at high force levels.

MATERIALS AND METHODS

Two groups of rats were trained to perform a voluntary repetitive lever-pulling task at either a high (HFHR) or a low force (LFHR) for 18 weeks, while a control group (FRC) performed no task. RNA and protein were prepared from forelimb flexor digitorum muscles. Fibrosis-related gene RNA transcripts were evaluated using quantitative PCR (qPCR) and analyzed using the geometric mean of three housekeeping genes or the mean of each individually as reference. Protein levels were quantified using ELISA, western blot, or immunohistofluorescence.

RESULTS

Of eight fibrosis-related mRNAs examined, only FGF2 demonstrated a consistent significant increase in the HFHR group, compared to the FRC group. However, protein amounts of collagen type 1, collagen type 3, and TGFβ1 were significantly higher in the HFHR, compared to the FRC and LFHR groups, while CCN2 and FGF2 were higher in both HFHR and LFHR, compared to the FRC group.

CONCLUSIONS

Our results suggest that there is steady-state transcription of fibrogenic genes in muscles with established fibrosis, implying that post-transcriptional processes are responsible for the increased protein levels of fibrotic factors during muscle overuse conditions. We hypothesize that targeting such pathways represents a valid approach to treat overuse injury. Alternatively, FGF2 gene expression may represent a valid target for therapy.

Tyrosine kinase inhibitor neratinib attenuates liver fibrosis by targeting activated hepatic stellate cells

Liver fibrosis, a common outcome of chronic liver disease characterized by excessive accumulation of extracellular matrix (ECM), is a leading cause of mortality worldwide. The tyrosine kinase inhibitor neratinib is a human epidermal growth factor receptor 2 (HER2) inhibitor approved by the FDA for HER2-positive breast cancer treatment; however, it has not yet been evaluated for liver fibrosis treatment. We elucidated the anti-fibrotic effects of neratinib in hepatic stellate cells (HSCs) and in vivo models of CCl₄-induced liver fibrosis. HSC activation is a key step in liver fibrogenesis and has a crucial role in collagen deposition, as it is primarily responsible for excessive ECM production. The effect of neratinib on HSC was evaluated in transforming growth factor (TGF-β)-incubated LX-2 cells and culture-activated primary human HSCs. In vivo study results indicated that neratinib inhibited the inflammatory response, HSC differentiation, and collagen accumulation induced by CCl₄. Moreover, the anti-fibrotic effects of neratinib were not associated with the HER2 signaling pathways. Neratinib inhibited FGF2 expression in activated HSCs and serum FGF2 level in the model, suggesting that neratinib possessed therapeutic potency against liver fibrosis and the potential for application against other fibrotic diseases.

Blocking CTGF/CCN2 reduces established skeletal muscle fibrosis in a rat model of overuse injury

Tissue fibrosis is a hallmark of overuse musculoskeletal injuries and contributes to functional declines. We tested whether inhibition of CCN2 (cellular communication network factor 2, previously known as connective tissue growth factor, CTGF) using a specific antibody (termed FG‐3019 or pamrevlumab) reduces established overuse‐induced muscle fibrosis in a clinically relevant rodent model of upper extremity overuse injury. Young adult rats performed a high repetition high force (HRHF) reaching and lever‐pulling task for 18 weeks, after first being shaped for 6 weeks to learn this operant task. Rats were then euthanized (HRHF‐Untreated), or rested and treated for 6 weeks with FG‐3019 (HRHF‐Rest/FG‐3019) or a human IgG as a vehicle control (HRHF‐Rest/IgG). HRHF‐Untreated and HRHF‐Rest/IgG rats had higher muscle levels of several fibrosis‐related proteins (TGFβ1, CCN2, collagen types I and III, and FGF2), and higher muscle numbers of alpha SMA and pERK immunopositive cells, compared to control rats. Each of these fibrogenic changes was restored to control levels by the blocking of CCN2 signaling in HRHF‐Rest/FG‐3019 rats, as were HRHF task‐induced increases in serum CCN2 and pro‐collagen I intact N‐terminal protein. Levels of cleaved CCN3, an antifibrotic protein, were lowered in HRHF‐Untreated and HRHF‐Rest/IgG rats, compared to control rats, yet elevated back to control levels in HRHF‐Rest/FG‐3019 rats. Significant grip strength declines observed in HRHF‐Untreated and HRHF‐Rest/IgG rats, were restored to control levels in HRHF‐Rest/FG‐3019 rats. These results are highly encouraging for use of FG‐3019 for therapeutic treatment of persistent skeletal muscle fibrosis, such as those induced with chronic overuse.

A new FGFR inhibitor disrupts the TGF-β1-induced fibrotic process

Pulmonary fibrosis (PF) is chronic and irreversible damage to the lung characterized by fibroblast activation and matrix deposition. Although recently approved novel anti‐fibrotic agents can improve the lung function and survival of patients with PF, the overall outcomes remain poor. In this study, a novel imidazopurine compound, 3‐(2‐chloro‐6‐fluorobenzyl)‐1,6,7‐trimethyl‐1H‐imidazo[2,1‐f]purine‐2,4(3H,8H)‐dione (IM‐1918), markedly inhibited transforming growth factor (TGF)‐β‐stimulated reporter activity and reduced the expression of representative fibrotic markers, such as connective tissue growth factor, fibronectin, collagen and α‐smooth muscle actin, on human lung fibroblasts. However, IM‐1918 neither decreased Smad‐2 and Smad‐3 nor affected p38MAPK and JNK. Instead, IM‐1918 reduced Akt and extracellular signal‐regulated kinase 1/2 phosphorylation increased by TGF‐β. Additionally, IM‐1918 inhibited the phosphorylation of fibroblast growth factor receptors 1 and 3. In a bleomycin‐induced murine lung fibrosis model, IM‐1918 profoundly reduced fibrotic areas and decreased collagen and α‐smooth muscle actin accumulation. These results suggest that IM‐1918 can be applied to treat lung fibrosis.

PIN1, a perspective on genetic biomarker for nonalcoholic fatty liver disease (NAFLD)

OBJECTIVE

A novel genetic and molecular basis of nonalcoholic fatty liver disease (NAFLD) was explored.

STUDY DESIGN

A 38-year-old male, who has no bad living and dietary habits, was diagnosed as NAFLD. The potential pathogenic role of Pin1 was evaluated by enzyme-linked immunosorbent (ELISA) assay and single nucleotide polymorphism (SNP) sequencing.

RESULTS

ELISA determined a six-time higher concentration of plasma Pin1 compared to our previous data. Nine PIN1 SNPs were sequenced and classified according to their NAFLD-pathogenic risks, suggesting that rs2233678 and rs2287839 may be the most important genotypes that result in Pin1 overexpression and NAFLD development.

CONCLUSION

In summary, this work explores a novel basis for early-onset NAFLD and highlights that elevated plasma Pin1 may predict NAFLD risk at early stage. Hypothetically, inhibiting Pin1 may benefit NAFLD prevention in the future.

Developmental pathways in the pathogenesis of lung fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and terminal lung disease with no known cure. IPF is a disease of aging, with median age of diagnosis over 65 years. Median survival is between 3 and 5 years after diagnosis. IPF is characterized primarily by excessive deposition of extracellular matrix (ECM) proteins by activated lung fibroblasts and myofibroblasts, resulting in reduced gas exchange and impaired pulmonary function. Growing evidence supports the concept of a pro-fibrotic environment orchestrated by underlying factors such as genetic predisposition, chronic injury and aging, oxidative stress, and impaired regenerative responses may account for disease development and persistence. Currently, two FDA approved drugs have limited efficacy in the treatment of IPF. Many of the genes and gene networks associated with lung development are induced or activated in IPF. In this review, we analyze current knowledge in the field, gained from both basic and clinical research, to provide new insights into the disease process, and potential approaches to treatment of pulmonary fibrosis.

Fibroblast growth factor receptor 1 antagonism attenuates lipopolysaccharide-induced activation of hepatic stellate cells via suppressing inflammation

Activated hepatic stellate cells (HSCs) serve key roles in hepatic fibrosis by producing excessive extracellular matrix (ECM) components. Lipopolysaccharide (LPS) has been found to be associated with hepatic fibrogenesis through direct interactions with HSCs. Recently, the fibroblast growth factor receptor 1 (FGFR1) signalling system was identified as a key player in the process of liver fibrosis. In the present study it was evaluated whether FGFR1 mediated LPS-induced HSCs activation. In cultured cells, FGFR1 was inhibited by either siRNA silencing or by a small-molecule inhibitor in LPS-stimulated HSCs. The blockade of FGFR1 decreased LPS-induced nuclear factor-κB (NF-κB) activation, inflammatory cytokine release, fibrosis, and cell proliferation in HSCs. It was further indicated that LPS triggered FGFR1 phosphorylation via TLR4/c-Src. These findings confirmed the detrimental effect of FGFR1 activation in the pathogenesis of LPS-related HSC activation and revealed that FGFR1 may be an ideal therapeutic target for LPS-induced liver fibrosis.

Key Anti-Fibrosis Associated Long Noncoding RNAs Identified in Human Hepatic Stellate Cell via Transcriptome Sequencing Analysis

Hepatic fibrosis is the main pathological basis for chronic cirrhosis, and activated hepatic stellate cells (HSCs) are the primary cells involved in liver fibrosis. Our study analyzed anti-fibrosis long noncoding RNAs (lncRNAs) in activated human HSCs (hHSCs). We performed RNA sequencing (RNA-seq) and bioinformatics analysis to determine whether lncRNA expression profile changes between hHSCs activation and quiescence. Eight differentially expressed (DE) lncRNAs and three pairs of co-expression lncRNAs-mRNAs were verified by quantitative Real-Time Polymerase Chain Reaction (qRT-PCR). A total of 34146 DE lncRNAs were identified in this study. Via gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, we found several DE lncRNAs regulated hHSC activation by participating in DNA bending/packaging complex, growth factor binding and the Hippo signaling pathway (p < 0.05). With lncRNA–mRNA co-expression analysis, three lncRNAs were identified to be associated with connective tissue growth factor (CTGF), fibroblast growth factor 2 (FGF2) and netrin-4 (NTN4). The quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) results of the eight DE lncRNAs and three pairs of co-expression lncRNAs–mRNAs were consistent with the RNA-seq data and previous reports. Several lncRNAs may serve as potential targets to reverse the progression of liver fibrosis. This study provides a first insight into lncRNA expression profile changes associated with activated human HSCs.

Flavanones from Sedum sarmentosum Bunge Alleviate CCl4-Induced Liver Fibrosis in Rats by Targeting TGF-β1/TβR/Smad Pathway In Turn Inhibiting Epithelial Mesenchymal Transition

Objective

The aim of the study is to evaluate the therapeutic effects of flavanones from Sedum sarmentosum Bunge (FSSB) on CCl₄-induced liver fibrosis in rats and the underlying mechanisms of action.

Methods

An experimental model of liver fibrosis was established by subcutaneous injection of rats with CCl₄ (40% v/v, 3 ml/kg) twice per week for six weeks. FSSB (100, 200, and 400 mg/kg) was intragastrically administered once per day consecutively for five weeks.

Results

Our results showed that FSSB significantly attenuated CCl₄-induced liver fibrosis as evidenced by reducing the elevated levels of serum biochemical indexes and improving the histological changes, including decreasing the elevation in serum alanine transaminase (ALT), aspartate transaminase (AST), hyaluronic acid (HA), and laminin (LN) level, reducing infiltration of inflammatory cells and collagen fibers in liver tissue. In addition, compared to the model group, FSSB markedly downregulated the protein and mRNA expression of TGF-β1, TGF-β1 receptors I and II (TβRI and TβRII), Smad2, Smad3, and Vimentin in liver tissue, at the mean time upregulating the expression of Smad7 and E-cadherin.

Conclusions

The results suggest that FSSB alleviated CCl₄-induced liver fibrosis probably through inhibition of TGF-β/TβR/Smad pathway in turn inhibiting epithelial mesenchymal transition.

Therapeutic pro-fibrogenic signaling pathways in fibroblasts

Myofibroblasts (MFs) play a critical role in the progression of chronic inflammatory and fibroproliferative diseases in different tissues/organs, whatever the etiology. Fibrosis is preceded and sustained by persistent injury and inflammatory response in a profibrogenic scenario involving mutual interactions, operated by several mediators and pathways, of MFs and related precursor cells with innate immunity cells and virtually any cell type in a defined tissue. These interactions, mediators and related signaling pathways are critical in initiating and perpetuating the differentiation of precursor cells into MFs that in different tissues share peculiar traits and phenotypic responses, including the ability to proliferate, produce ECM components, migrate and contribute to the modulation of inflammatory response and tissue angiogenesis. Literature studies related to liver, lung and kidney fibrosis have outlined a number of MF-related core regulatory fibrogenic signaling pathways conserved across these different organs and potentially targetable in order to develop effective antifibrotic therapeutic strategies.

Pulmonary fibrosis requires cell-autonomous mesenchymal fibroblast growth factor (FGF) signaling

Idiopathic pulmonary fibrosis (IPF) is characterized by progressive pulmonary scarring, decline in lung function, and often results in death within 3-5 five years after diagnosis. Fibroblast growth factor (FGF) signaling has been implicated in the pathogenesis of IPF; however, the mechanism through which FGF signaling contributes to pulmonary fibrosis remains unclear. We hypothesized that FGF receptor (FGFR) signaling in fibroblasts is required for the fibrotic response to bleomycin. To test this, mice with mesenchyme-specific tamoxifen-inducible inactivation of FGF receptors 1, 2, and 3 (Col1α2-CreER; TCKO mice) were lineage labeled and administered intratracheal bleomycin. Lungs were collected for histologic analysis, whole lung RNA and protein, and dissociated for flow cytometry and FACS. Bleomycin-treated Col1α2-CreER; TCKO mice have decreased pulmonary fibrosis, collagen production, and fewer α-smooth muscle actin-positive (αSMA+) myofibroblasts compared with controls. Freshly isolated Col1α2-CreER; TCKO mesenchymal cells from bleomycin-treated mice have decreased collagen expression compared with wild type mesenchymal cells. Furthermore, lineage labeled FGFR-deficient fibroblasts have decreased enrichment in fibrotic areas and decreased proliferation. These data identify a cell autonomous requirement for mesenchymal FGFR signaling in the development of pulmonary fibrosis, and for the enrichment of the Col1α2-CreER-positive (Col1α2+) mesenchymal lineage in fibrotic tissue following bleomycin exposure. We conclude that mesenchymal FGF signaling is required for the development of pulmonary fibrosis, and that therapeutic strategies aimed directly at mesenchymal FGF signaling could be beneficial in the treatment of IPF.

Regulation of Hepatic Stellate Cells and Fibrogenesis by Fibroblast Growth Factors

Fibroblast growth factors (FGFs) are a family of growth factors critically involved in developmental, physiological, and pathological processes, including embryogenesis, angiogenesis, wound healing, and endocrine functions. In the liver, several FGFs are produced basally by hepatocytes and hepatic stellate cells (HSCs). Upon insult to the liver, expression of FGFs in HSCs is greatly upregulated, stimulating hepatocyte regeneration and growth. Various FGF isoforms have also been shown to directly induce HSC proliferation and activation thereby enabling autocrine and paracrine regulation of HSC function. Regulation of HSCs by the endocrine FGFs, namely, FGF15/19 and FGF21, has also recently been identified. With the ability to modulate HSC proliferation and transdifferentiation, targeting FGF signaling pathways constitutes a promising new therapeutic strategy to treat hepatic fibrosis.

Thalidomide Accelerates the Degradation of Extracellular Matrix in Rat Hepatic Cirrhosis via Down-Regulation of Transforming Growth Factor-β1

PURPOSE

The degradation of the extracellular matrix has been shown to play an important role in the treatment of hepatic cirrhosis. In this study, the effect of thalidomide on the degradation of extracellular matrix was evaluated in a rat model of hepatic cirrhosis.

MATERIALS AND METHODS

Cirrhosis was induced in Wistar rats by intraperitoneal injection of carbon tetrachloride (CCl₄) three times weekly for 8 weeks. Then CCl₄ was discontinued and thalidomide (100 mg/kg) or its vehicle was administered daily by gavage for 6 weeks. Serum hyaluronic acid, laminin, procollagen type III, and collagen type IV were examined by using a radioimmunoassay. Matrix metalloproteinase-13 (MMP-13), tissue inhibitor of metalloproteinase-1 (TIMP-1), and α-smooth muscle actin (α-SMA) protein in the liver, transforming growth factor β1 (TGF-β1) protein in cytoplasm by using immunohistochemistry and Western blot analysis, and MMP-13, TIMP-1, and TGF-β1 mRNA levels in the liver were studied using reverse transcriptase polymerase chain reaction.

RESULTS

Liver histopathology was significantly better in rats given thalidomide than in the untreated model group. The levels of TIMP-1 and TGF-β1 mRNA and protein expressions were decreased significantly and MMP-13 mRNA and protein in the liver were significantly elevated in the thalidomide-treated group.

CONCLUSION

Thalidomide may exert its effects on the regulation of MMP-13 and TIMP-1 via inhibition of the TGF-β1 signaling pathway, which enhances the degradation of extracellular matrix and accelerates the regression of hepatic cirrhosis in rats.

Validated prediction of pro-invasive growth factors using a transcriptome-wide invasion signature derived from a complex 3D invasion assay

The invasion of activated fibroblasts represents a key pathomechanism in fibrotic diseases, carcinogenesis and metastasis. Invading fibroblasts contribute to fibrotic extracellular matrix (ECM) formation and the initiation, progression, or resistance of cancer. To construct transcriptome-wide signatures of fibroblast invasion, we used a multiplex phenotypic 3D invasion assay using lung fibroblasts. Microarray-based gene expression profiles of invading and non-invading fibroblasts demonstrated that 1,049 genes were differentially regulated (>1.5-fold). Unbiased pathway analysis (Ingenuity) identified significant enrichment for the functional clusters 'invasion of cells', 'idiopathic pulmonary fibrosis', and 'metastasis'. Matrix metalloprotease 13 (MMP13), transforming growth factor (TGF)-β1, Caveolin (Cav) 1, Phosphatase and Tensin Homolog (Pten), and secreted frizzled-related protein (Sfrp) 1 were among the highest regulated genes, confirmed by qRT-PCR and Western Blotting. We next performed in silico analysis (Ingenuity Pathway Analysis) to predict mediators that induced fibroblast invasion. Of these, TGFβ1, epidermal growth factor (EGF), fibroblast growth factor (FGF) 2, and platelet-derived growth factor (PDGF)-BB were tested in our 3D invasion assay and found to significantly induce invasion, thus validating the transcriptome profile. Accordingly, our transcriptomic invasion signature describes the invading fibroblast phenotype in unprecedented detail and provides a tool for future functional studies of cell invasion and therapeutic modulation thereof using complex phenotypic assays.

Fibroblast growth factor 2 is required for epithelial recovery, but not for pulmonary fibrosis, in response to bleomycin

The pathogenesis of pulmonary fibrosis involves lung epithelial injury and aberrant proliferation of fibroblasts, and results in progressive pulmonary scarring and declining lung function. In vitro, fibroblast growth factor (FGF) 2 promotes myofibroblast differentiation and proliferation in cooperation with the profibrotic growth factor, transforming growth factor-β1, but the in vivo requirement for FGF2 in the development of pulmonary fibrosis is not known. The bleomycin model of lung injury and pulmonary fibrosis was applied to Fgf2 knockout (Fgf2(-/-)) and littermate control mice. Weight loss, mortality, pulmonary fibrosis, and histology were analyzed after a single intranasal dose of bleomycin. Inflammation was evaluated in bronchoalveolar lavage (BAL) fluid, and epithelial barrier integrity was assessed by measuring BAL protein and Evans Blue dye permeability. Fgf2 is expressed in mouse and human lung epithelial and inflammatory cells, and, in response to bleomycin, Fgf2(-/-) mice have significantly increased mortality and weight loss. Analysis of BAL fluid and histology show that pulmonary fibrosis is unaltered, but Fgf2(-/-) mice fail to efficiently resolve inflammation, have increased BAL cellularity, and, importantly, deficient recovery of epithelial integrity. Fgf2(-/-) mice similarly have deficient recovery of club cell secretory protein(+) bronchial epithelium in response to naphthalene. We conclude that FGF2 is not required for bleomycin-induced pulmonary fibrosis, but rather is essential for epithelial repair and maintaining epithelial integrity after bleomycin-induced lung injury in mice. These data identify that FGF2 acts as a protective growth factor after lung epithelial injury, and call into question the role of FGF2 as a profibrotic growth factor in vivo.

Mistletoe alkaloid fractions alleviates carbon tetrachloride-induced liver fibrosis through inhibition of hepatic stellate cell activation via TGF-β/Smad interference

ETHNOPHARMACOLOGICAL RELEVANCE

Mistletoe (Viscum coloratum (Kom.) Nakai) has long been categorized as a traditional herbal medicine in Asia. In addition to its application in cancer therapy, mistletoe has also been used in the treatment of chronic hepatic disorders in China. In the present study, we investigated the antifibrotic effect and mechanisms of action of mistletoe extracts in a rat model of carbon tetrachloride (CCl4)-induced hepatotoxicity.

MATERIALS AND METHODS

An experimental model of hepatic fibrosis was established by intraperitoneal injection of rats with CCl4 for 8 weeks. Rats were subsequently treated with a mistletoe alkaloid fraction preparation via oral administration (120mg/kg daily for 8 weeks) or with distilled water as a control. Histopathological changes were observed by hematoxylin and eosin staining and Masson׳s trichrome staining. The expression of markers relevant to hepatic stellate cell (HSC) activation in the liver was assessed by real-time reverse transcription-polymerase chain reaction, immunohistochemistry and western blotting. The anti-fibrosis activity and mechanisms of action of mistletoe alkaloid fractions were further investigated in the HSC-T6 HSC line, following treatment with mistletoe alkaloid fractions (12mg/ml) for 48h.

RESULTS

Hepatic fibrosis decreased markedly in CCl4-treated animals following treatment with mistletoe alkaloid fractions, compared to controls. The mRNA levels of transforming growth factor-β1 (TGF-β1), procollagen I and tissue inhibitors of metalloproteinases (TIMPs) were significantly downregulated, by about 40%, 40% and 45%, respectively, in liver tissues from rats treated with mistletoe alkaloid fractions. Furthermore, significant downregulation of TGF-β1, TGF-β1 receptor, phosphorylated Smad 2 and alpha smooth muscle actin (α-SMA) proteins, by about 45%, 30% and 40%, respectively, was also observed in liver tissues from mistletoe alkaloid fractions-treated rats. In contrast, Smad 7 levels were significantly increased by about 30% in mistletoe alkaloid fractions-treated rats. Treatment of HSC-T6 cells with mistletoe alkaloid fractions significantly induced Smad 7 expression and inhibited the expression of α-SMA, TGFβ1, TGF-β1 receptor, Smad 2 and TIMP-1, in vitro.

CONCLUSION

We demonstrate that mistletoe alkaloid fractions decrease extracellular matrix accumulation by inhibiting HSC activation. Mechanistically, this may occur via inhibition of TGF-β1/Smad 2 and Smad 7 signal transduction, thereby blocking the synthesis of procollagen I and TIMP-1. These findings suggest that mistletoe alkaloid fractions may be a potential therapeutic agent for the treatment of hepatic fibrosis.

Current strategies for inhibiting FGFR activities in clinical applications: opportunities, challenges and toxicological considerations

Aberrations in fibroblast growth factor receptor (FGFR) signaling are instrumental to the pathophysiology of several malignancies and disorders. Hence, FGFR inhibitors are explored in therapeutics with early candidates developed as competitors for the ATP-binding pocket in the kinase domain. More recent programs yielded compounds of diverse scaffolds with alternative binding modes. Concurrently, monoclonal antibodies and peptide-based agents provide independent options for clinical development. Notwithstanding this rapid progress, we contemplate the toxicological impact of FGFR inhibition based on the defined role of FGFR family members in physiology and homeostasis. The high homology among FGFR1-4 and also with other kinase subfamilies creates an additional challenge in developing selective inhibitors. It orchestrates an ongoing conundrum of moderating a balance between synergism through multitargeting kinase inhibition and minimizing off-target toxicities.

FGF receptors: cancer biology and therapeutics

Fibroblast growth factors (FGFs) are involved in a variety of cellular processes, such as stemness, proliferation, anti-apoptosis, drug resistance, and angiogenesis. Here, FGF signaling network, cancer genetics/genomics of FGF receptors (FGFRs), and FGFR-targeted therapeutics will be reviewed. FGF signaling to RAS-MAPK branch and canonical WNT signaling cascade mutually regulate transcription programming. FGF signaling to PI3K-AKT branch and Hedgehog, Notch, TGFβ, and noncanonical WNT signaling cascades regulate epithelial-to-mesenchymal transition (EMT) and invasion. Gene amplification of FGFR1 occurs in lung cancer and estrogen receptor (ER)-positive breast cancer, and that of FGFR2 in diffuse-type gastric cancer and triple-negative breast cancer. Chromosomal translocation of FGFR1 occurs in the 8p11 myeloproliferative syndrome and alveolar rhabdomyosarcoma, as with FGFR3 in multiple myeloma and peripheral T-cell lymphoma. FGFR1 and FGFR3 genes are fused to neighboring TACC1 and TACC3 genes, respectively, due to interstitial deletions in glioblastoma multiforme. Missense mutations of FGFR2 are found in endometrial uterine cancer and melanoma, and similar FGFR3 mutations in invasive bladder tumors, and FGFR4 mutations in rhabdomyosarcoma. Dovitinib, Ki23057, ponatinib, and AZD4547 are orally bioavailable FGFR inhibitors, which have demonstrated striking effects in preclinical model experiments. Dovitinib, ponatinib, and AZD4547 are currently in clinical trial as anticancer drugs. Because there are multiple mechanisms of actions for FGFR inhibitors to overcome drug resistance, FGFR-targeted therapy is a promising strategy for the treatment of refractory cancer. Whole exome/transcriptome sequencing will be introduced to the clinical laboratory as the companion diagnostic platform facilitating patient selection for FGFR-targeted therapeutics in the era of personalized medicine.

An integrative genomic and transcriptomic analysis reveals potential targets associated with cell proliferation in uterine leiomyomas

Background

Uterine Leiomyomas (ULs) are the most common benign tumours affecting women of reproductive age. ULs represent a major problem in public health, as they are the main indication for hysterectomy. Approximately 40–50% of ULs have non-random cytogenetic abnormalities, and half of ULs may have copy number alterations (CNAs). Gene expression microarrays studies have demonstrated that cell proliferation genes act in response to growth factors and steroids. However, only a few genes mapping to CNAs regions were found to be associated with ULs.

Methodology

We applied an integrative analysis using genomic and transcriptomic data to identify the pathways and molecular markers associated with ULs. Fifty-one fresh frozen specimens were evaluated by array CGH (JISTIC) and gene expression microarrays (SAM). The CONEXIC algorithm was applied to integrate the data.

Principal Findings

The integrated analysis identified the top 30 significant genes (P<0.01), which comprised genes associated with cancer, whereas the protein-protein interaction analysis indicated a strong association between FANCA and BRCA1. Functional in silico analysis revealed target molecules for drugs involved in cell proliferation, including FGFR1 and IGFBP5. Transcriptional and protein analyses showed that FGFR1 (P = 0.006 and P<0.01, respectively) and IGFBP5 (P = 0.0002 and P = 0.006, respectively) were up-regulated in the tumours when compared with the adjacent normal myometrium.

Conclusions

The integrative genomic and transcriptomic approach indicated that FGFR1 and IGFBP5 amplification, as well as the consequent up-regulation of the protein products, plays an important role in the aetiology of ULs and thus provides data for potential drug therapies development to target genes associated with cellular proliferation in ULs.

Transforming growth factor-β genetic polymorphisms on development of liver cirrhosis in a meta-analysis

Transforming growth factor-β (TGF-β) protein has been supposed to be a risk factor for liver cirrhosis; however, the associations between its genes (TGF-β -509C>T and +869T>C) and liver cirrhosis remained unclear. This study was to quantitatively analyze the correlations by using a meta-analysis. Pubmed, Embase, Wanfang databases were retrieved up to November 1st, 2011. Odds ratio (OR) and 95 % confidence interval (95 %CI) were used to demonstrate the strength of association, and P < 0.05 of Z test indicated statistical significance. Combined analyses were performed by using fixed or random-effect model, depending on between-study heterogeneity. Seven studies were for TGF-β -509C>T polymorphism, and eight studies were for +869T>C polymorphism. Combined results indicated that neither TGF-β -509C>T nor +869T>C polymorphisms were associated with risk of liver cirrhosis [OR (95 % CI): 0.79 (0.60-1.04) for CT vs. TT of -509C>T and 0.87 (0.68-1.12) for CT vs. CC of +869T>C], with no between-study heterogeneity. In addition, subgroups analyses still inferred that two polymorphisms were not associated with risk of liver cirrhosis for HBV-infected patients, Asians and for Population-based studies. This meta-analysis indicated that neither TGF-β -509C>T nor +869T>C polymorphisms were associated with risk of liver cirrhosis, regardless of HBV infection or not.

Annexin A10 in human oral cancer: biomarker for tumoral growth via G1/S transition by targeting MAPK signaling pathways

Background

Annexins are calcium and phospholipid binding proteins that form an evolutionary conserved multigene family. Considerable evidence indicates that annexin A10 (ANXA10) is involved in tumoral progression, although little is known about its role in human oral carcinogenesis. In this study, we investigated the involvement of ANXA10 in oral squamous cell carcinoma (OSCC).

Methodology/Principal Findings

ANXA10 mRNA and protein expressions were assessed by quantitative reverse transcriptase polymerase chain reaction and immunoblotting, and we conducted a proliferation assay and cell-cycle analysis in ANXA10 knockdown cells in vitro. We evaluated the correlation between the ANXA10 expression status in 100 primary OSCCs and the clinicopathological features by immunohistochemistry. ANXA10 mRNA and protein expression levels were up-regulated in all cellular lines examined (n = 7, p<0.05). ANXA10 knockdown cells showed that cellular proliferation decreased by inactivation of extracellular regulated kinase (ERK) (p<0.05), and cell-cycle arrest at the G1 phase resulted from up-regulation of cyclin-dependent kinase inhibitors. ANXA10 protein expression in primary OSCCs was also significantly greater than in normal counterparts (p<0.05), and higher expression was correlated with tumoral size (p = 0.027).

Conclusions/Significance

Our results proposed for the first time that ANXA10 is an indicator of cellular proliferation in OSCCs. Our results suggested that ANXA10 expression might indicate cellular proliferation and ANXA10 might be a potential therapeutic target for the development of new treatments for OSCCs.

Correlation between TGF-β1-509 C>T polymorphism and risk of digestive tract cancer in a meta-analysis for 21,196 participants

The association between transforming growth factor β1 (TGF-β1)-509 C>T and risk of digestive tract cancer (DTC) remained uncertain as previous studies reported conflicting results. The aim of this study was to assess the association by using a meta-analysis. The databases of MEDLINE, EMBASE and WANGFANG (Chinese database) were retrieved, and latest update was on 2nd February, 2012. Pooled odds ratio and 95% confidence interval (OR and 95% CI) were calculated by using a fixed- or random-effect model. Ultimately, twenty nine case-control studies with 8664 cases and 12,532 controls were included in this meta-analysis. Overall, there was no association between TGF-β1-509 C>T and risk of DTC in all genetic comparison models (OR and 95% CI: 0.96 and 0.81-1.15 for TT vs. CC, 0.98 and 0.91-1.05 for T carriers vs. C carriers). When subgroup analyses were conducted according to ethnicity, types of cancer and sample size, T allele was significantly associated with decreased risk of DTC for Caucasians and for large sample-sized studies, and was associated with decreased risk of colorectal cancer (OR and 95% CI for TT vs. CC: 0.82 and 0.70-0.97 for Caucasians, 0.80 and 0.68-0.98 for large sample-sized studies, 0.78 and 0.62-0.97 for colorectal cancer). This study indicated that TGF-β1-509 C>T polymorphism was probably associated with risk of DTC, especially for Caucasians. Because of modest limitation, our findings should be confirmed by future studies.

Blocking Fibroblast Growth Factor receptor signaling inhibits tumor growth, lymphangiogenesis, and metastasis

Fibroblast Growth Factor receptor (FGFR) activity plays crucial roles in tumor growth and patient survival. However, FGF (Fibroblast Growth Factor) signaling as a target for cancer therapy has been under-investigated compared to other receptor tyrosine kinases. Here, we studied the effect of FGFR signaling inhibition on tumor growth, metastasis and lymphangiogenesis by expressing a dominant negative FGFR (FGFR-2DN) in an orthotopic mouse mammary 66c14 carcinoma model. We show that FGFR-2DN-expressing 66c14 cells proliferate in vitro slower than controls. 66c14 tumor outgrowth and lung metastatic foci are reduced in mice implanted with FGFR-2DN-expressing cells, which also exhibited better overall survival. We found 66c14 cells in the lumen of tumor lymphatic vessels and in lymph nodes. FGFR-2DN-expressing tumors exhibited a decrease in VEGFR-3 (Vascular Endothelial Growth Factor Receptor-3) or podoplanin-positive lymphatic vessels, an increase in isolated intratumoral lymphatic endothelial cells and a reduction in VEGF-C (Vascular Endothelial Growth Factor-C) mRNA expression. FGFs may act in an autocrine manner as the inhibition of FGFR signaling in tumor cells suppresses VEGF-C expression in a COX-2 (cyclooxygenase-2) or HIF1-α (hypoxia-inducible factor-1 α) independent manner. FGFs may also act in a paracrine manner on tumor lymphatics by inducing expression of pro-lymphangiogenic molecules such as VEGFR-3, integrin α9, prox1 and netrin-1. Finally, in vitro lymphangiogenesis is impeded in the presence of FGFR-2DN 66c14 cells. These data confirm that both FGF and VEGF signaling are necessary for the maintenance of vascular morphogenesis and provide evidence that targeting FGFR signaling may be an interesting approach to inhibit tumor lymphangiogenesis and metastatic spread.