Interaction between insulin-like growth factor binding protein-related protein 1 and transforming growth factor beta 1 in primary hepatic stellate cells

IGFBP7 remodels the tumor microenvironment of esophageal squamous cell carcinoma by activating the TGFβ1/SMAD signaling pathway

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer, and its development, growth, and invasiveness are regulated by the tumor microenvironment (TME). Insulin-like growth factor-binding protein-7 (IGFBP7), which is closely related to various tumors, transforming growth factor-β1 (TGFβ1), which is a key signal mediator in oncogenesis, α-smooth muscle actin (α-SMA), and collagen I are important components of the TME. IGFBP7 can upregulate the expression of TGFβ1 and activate the TGFβ1/SMAD signaling pathway, which leads to an increase in collagen I in hepatic stellate cells (HSCs). However, the contribution of IGFBP7 to TGFβ1 and the TME in the progression of ESCC remains unknown. In the present study, we investigated IGFBP7 expression and its effects on TGFβ1 and the TME in ESCC. A total of 45 patients were divided into three groups: early-tumor group (n=15), advanced-tumor group (n=15), and paracancer control group (n=15). The EC109 cell line was cultured and treated with AdIGFBP7 and LvshTGFβ1, and the expression levels of IGFBP7, TGFβ1, α-SMA, collagen I, and p-SMAD2/3 were determined by immunohistochemical staining and western blotting analysis. IGFBP7, TGFβ1, α-SMA, and collagen I were upregulated in the ESCC samples compared with the control samples (P<0.05), and the values peaked in the advanced-tumor group (P<0.05). Compared with the control group, the TGFβ1, α-SMA, p-SMAD2/3, and collagen I proteins were gradually increased from 24 to 72 h in the EC109 cells treated with AdIGFBP7 (P<0.05). Inhibition of TGFβ1 expression in the EC109 cells treated with AdIGFBP7 gradually reduced the expression of α-SMA, collagen I, and p-SMAD2/3 from 24 to 72 h (P<0.05). These findings suggest that increased IGFBP7 may accelerate the progression of ESCC by upregulating TGFβ1, α-SMA, and collagen I via activating the TGFβ1/SMAD signaling pathway, which could remodel the TME.

IGFBP-6/sonic hedgehog/TLR4 signalling axis drives bone marrow fibrotic transformation in primary myelofibrosis

Primary myelofibrosis is a Ph-negative chronic myeloproliferative neoplasm characterized by bone marrow fibrosis and associated with the involvement of several pathways, in addition to bone marrow microenvironment alterations, mostly driven by the activation of the cytokine receptor/JAK2 pathway. Identification of driver mutations has led to the development of targeted therapy for myelofibrosis, contributing to reducing inflammation, although this currently does not translate into bone marrow fibrosis remission. Therefore, understanding the clear molecular cut underlying this pathology is now necessary to improve the clinical outcome of patients. The present study aims to investigate the involvement of IGFBP-6/sonic hedgehog /Toll-like receptor 4 axis in the microenvironment alterations of primary myelofibrosis. We observed a significant increase in IGFBP-6 expression levels in primary myelofibrosis patients, coupled with a reduction to near-normal levels in primary myelofibrosis patients with JAK2V617F mutation. We also found that both IGFBP-6 and purmorphamine, a SHH activator, were able to induce mesenchymal stromal cells differentiation with an up-regulation of cancer-associated fibroblasts markers. Furthermore, TLR4 signaling was also activated after IGFBP-6 and purmorphamine exposure and reverted by cyclopamine exposure, an inhibitor of the SHH pathway, confirming that SHH is involved in TLR4 activation and microenvironment alterations. In conclusion, our results suggest that the IGFBP-6/SHH/TLR4 axis is implicated in alterations of the primary myelofibrosis microenvironment and that IGFBP-6 may play a central role in activating SHH pathway during the fibrotic process.

Role of long non‑coding RNAs and related epigenetic mechanisms in liver fibrosis (Review)

Liver fibrosis is one of the major liver pathologies affecting patients worldwide. It results from an improper tissue repair process following liver injury or inflammation. If left untreated, it ultimately leads to liver cirrhosis and liver failure. Long non‑coding RNAs (lncRNAs) have been implicated in a wide variety of diseases. They can regulate gene expression and modulate signaling. Some of the lncRNAs promote, while others inhibit liver fibrosis. Similarly, other epigenetic processes, such as methylation and acetylation regulate gene transcription and can modulate gene expression. Notably, there are several regulatory associations of lncRNAs with other epigenetic processes. A major mechanism of action of long non‑coding RNAs is to competitively bind to their target microRNAs (miRNAs or miRs), which in turn affects miRNA availability and bioactivity. In the present review, the role of lncRNAs and related epigenetic processes contributing to liver fibrosis is discussed. Finally, various potential therapeutic approaches targeting lncRNAs and related epigenetic processes, which are being considered as possible future treatment targets for liver fibrosis are identified.

SIRT1/IGFBPrP1/TGF β1 axis involved in cucurbitacin B ameliorating concanavalin A-induced mice liver fibrosis

The present study investigated the improving effect of cucurbitacin B on liver fibrosis induced by concanavalin A in mice and explored its possible mechanism. AST, ALT and TB were detected by kits. ELISA was performed to detect the levels of IL 5, IL 6, IL 13 and TNF-α in serum. Haematoxylin-eosin (HE) staining and Masson's trichrome staining were used to evaluate pathological changes. Western blotting was performed to observe expression levels of sirtuin (SIRT) 1, insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) and TGF β1. The activity of SIRT 1 also was detected. Results showed that cucurbitacin B could effectively improve the abnormal liver function, inhibit liver fibrosis and suppress releases of inflammatory factors in mice induced by concanavalin A. Furthermore, cucurbitacin B could down-regulate the expressions of TGF β1 and IGFBPrP1, increase the expression and activity of SIRT 1. Interestingly, when SIRT1 activity was inhibited by EX 527, a selective inhibitor of SIRT 1, the preventive effect of cucurbitacin B was significantly attenuated. Taken together, the above results showed that cucurbitacin B could significantly suppress releases of inflammatory cytokines and improve liver fibrosis induced by concanavalin A in mice, and those may be achieved through SIRT1/IGFBPrP1/TGF β1 axis.

Differential production of insulin-like growth factor-binding proteins in liver fibrosis progression

Noninvasive methods for liver disease diagnoses offer great advantages over biopsy, but they cannot be utilized in all cases. Therefore, specific indicators for chronic liver disease management are necessary. The aim was to assess the production of insulin-like growth factor-binding proteins (IGFBPs) 1-7 and their correlation with the different stages of fibrosis in chronic hepatitis C (CHC). A prospective, cross-sectional, multicenter study was conducted. CHC patients were categorized by FibroTest® and/or FibroScan®. Serum concentrations of IGFBPs 1-7 were determined through multiple suspension arrangement array technology. Significant differences were validated by the Kruskal-Wallis and Mann-Whitney U tests. Logistic regression models were performed to assess the association between the IGFBPs and fibrosis stages. The association was determined utilizing odds ratios (ORs), and receiver operating characteristic (ROC) curves were constructed to distinguish the IGFBPs in relation to the diagnosis of fibrosis. IGFBP-1 and IGFBP-7 concentrations were higher in CHC than in the healthy individuals, whereas IGFBP-3, IGFBP-5, and IGFBP-6 were downregulated in the patients. An apparent increase of all the IGFBPs was found at fibrosis stage F4, but with different regulations. IGFBP-2, -4, -6, and -7 had the best OR, showing the relation to fibrosis progression. The ROC curves showed that IGFBP-7 was the only protein that distinguished F1 from F3 and F2 from F3. IGFBPs participate in liver fibrosis progression and could be employed as circulating novel protein panels for diagnosis and as possible therapeutic targets in liver fibrosis progression.

The Roles and Mechanisms of lncRNAs in Liver Fibrosis

Many studies have revealed that circulating long noncoding RNAs (lncRNAs) regulate gene and protein expression in the process of hepatic fibrosis. Liver fibrosis is a reversible wound healing response followed by excessive extracellular matrix accumulation. In the development of liver fibrosis, some lncRNAs regulate diverse cellular processes by acting as competing endogenous RNAs (ceRNAs) and binding proteins. Previous investigations demonstrated that overexpression of lncRNAs such as H19, maternally expressed gene 3 (MEG3), growth arrest-specific transcript 5 (GAS5), Gm5091, NR_002155.1, and HIF 1alpha-antisense RNA 1 (HIF1A-AS1) can inhibit the progression of liver fibrosis. Furthermore, the upregulation of several lncRNAs [e.g., nuclear paraspeckle assembly transcript 1 (NEAT1), hox transcript antisense RNA (Hotair), and liver-enriched fibrosis-associated lncRNA1 (lnc-LFAR1)] has been reported to promote liver fibrosis. This review will focus on the functions and mechanisms of lncRNAs, the lncRNA transcriptome profile of liver fibrosis, and the main lncRNAs involved in the signalling pathways that regulate hepatic fibrosis. This review provides insight into the screening of therapeutic and diagnostic markers of liver fibrosis.

Insulin-Like Growth Factor Binding Protein-Related Protein 1 Activates Primary Hepatic Stellate Cells via Autophagy Regulated by the PI3K/Akt/mTOR Signaling Pathway

BACKGROUND

Autophagy is a self-degrading process. Previously, we showed that insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) is a novel transforming growth factor β1 (TGFβ1)-interacting factor in liver fibrosis; the role of TGFβ1-mediated autophagy in hepatic stellate cells (HSCs) activation has been investigated. However, whether autophagy is regulated by IGFBPrP1 remains unknown.

AIMS

We investigated the interactions among IGFBPrP1, autophagy, and activation of primary rat HSCs.

METHODS

Primary HSCs were separated from Sprague Dawley rats by two-step enzymatic digestion, and then, we overexpressed or inhibited IGFBPrP1 expression in HSCs under serum-starved condition. Autophagy inducer rapamycin or inhibitor 3-methyladenine (3MA) was used to assess the relationship between autophagy and HSCs activation.

RESULTS

We observed the expression of activation marker α-SMA and autophagy markers such as LC3B and Beclin1, which were significantly increased in HSCs treated with adenovirus vector harboring the IGFBPrP1 gene (AdIGFBPrP1) compared to cells cultured under serum-starved. In comparison, HSCs treated with shIGFBPrP1 showed opposite results. Furthermore, HSCs activation and autophagy increased when cells were treated with rapamycin, whereas opposite results were obtained when cells were treated with 3MA. AdIGFBPrP1 treatment downregulated the phosphorylation of Akt and mTOR.

CONCLUSION

Autophagy was induced in IGFBPrP1-treated primary HSCs, and IGFBPrP1-induced autophagy promoted the activation of HSCs and extracellular matrix expression, the underlying mechanism of which may involve the phosphatidylinositide 3-kinase/Akt/mTOR signaling pathway.

Production of insulin-like growth factor-binding proteins during the development of hepatic fibrosis due to chronic hepatitis C

INTRODUCTION AND AIMS

Insulin-like growth factor 1 is modulated by the insulin-like growth factor-binding proteins (IGFBPs) that are synthesized in the liver. The aim of the present study was to evaluate the concentrations of IGFBPs 1-7 in patients with chronic hepatitis C and study their association with fibrosis stage.

PATIENTS AND METHODS

A prospective, cross-sectional study was conducted that included patients with chronic hepatitis C. The stages of fibrosis were determined through FibroTest and FibroScan and the patients were compared with a control group. Serum levels of IGFBPs 1-7 were quantified through multiple suspension arrays. The Kruskal-Wallis test, Mann-Whitney U test, Spearman's correlation, and ROC curves were used for the statistical analysis.

RESULTS

Upon comparing the patients and controls, the highest concentrations were found in IGFBPs 1, 2, 4, and 7 (p=0.02, p=0.002, p=0.008, and p<0.001, respectively). IGFBP-3 levels had a tendency to be lower in the patients (p=0.066), whereas values were similar between patients and controls for IGFBP-5 and 6 (p=0.786 and p=0.244, respectively). Of the seven IGFBPs, IGFBP-3 concentrations were the highest. There were significant differences between fibrosis stages for IGFBP-5 and IGFBP-7.

CONCLUSION

IGFBPs play a relevant role in the fibrotic process in liver damage. IGFBP-7, in particular, differentiates fibrosis stages, making it a potential serum biomarker.

The lncRNA NEAT1/miR-29b/Atg9a axis regulates IGFBPrP1-induced autophagy and activation of mouse hepatic stellate cells

AIMS

Insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) promotes hepatic stellate cell (HSC) autophagy and activation. However, the underlying mechanism remains unknown. Noncoding RNAs (ncRNAs) including long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), have received increasing attention. We aimed to investigate the roles of the lncRNA nuclear enriched abundant transcript 1 (NEAT1), miR-29b, and autophagy related protein 9a (Atg9a), and their relationships with each other during IGFBPrP1-induced HSC autophagy and activation.

MAIN METHODS

Levels of NEAT1, miR-29b, Atg9a, and autophagy were detected in adenovirus-mediated IGFBPrP1 (AdIGFBPrP1)-treated mouse liver tissue and immortalized mouse hepatic stellate cell line JS1 transfected with either AdIGFBPrP1 or siIGFBPrP1. In AdIGFBPrP1-treated JS1 cells, autophagy and activation were detected after altering NEAT1, miR-29b, or Atg9a levels. In AdIGFBPrP1-treated JS1 cells, relationships among NEAT1, miR-29b, and Atg9a were explored using dual-luciferase reporter assays, Western blot, qRT-PCR, and immunofluorescence.

KEY FINDINGS

IGFBPrP1 increased levels of NEAT1, Atg9a, and autophagy while decreasing the level of miR-29b in mouse liver tissues and mouse HSCs. Moreover, NEAT1 increased HSC autophagy and activation while miR-29b decreased both processes. Atg9a also participated in IGFBPrP1-induced HSC autophagy and activation. Importantly, NEAT1, miR-29b, and Atg9a formed a NEAT1/miR-29b/Atg9a regulatory axis for IGFBPrP1-induced HSC autophagy and activation.

SIGNIFICANCE

Our study unveiled the new NEAT1/miR-29b/Atg9a regulatory axis involved in IGFBPrP1-induced mouse HSC autophagy and activation. The study thus provides new insights in the pathogenesis and potential therapeutic strategies of liver fibrosis.

Insulin-like growth factor binding protein related protein 1 knockdown attenuates hepatic fibrosis via the regulation of MMPs/TIMPs in mice

BACKGROUND

Previous research suggested that insulin-like growth factor binding protein related protein 1 (IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) play an essential role in hepatic fibrogenesis by regulating homeostasis and remodeling of the extracellular matrix (ECM). However, the interaction between IGFBPrP1 and MMP/TIMP is not clear. The present study was to knockdown IGFBPrP1 to investigate the correlation between IGFBPrP1 and MMP/TIMP in hepatic fibrosis.

METHODS

Hepatic fibrosis was induced by thioacetamide (TAA) in mice. Knockdown of IGFBPrP1 expression by ultrasound-targeted microbubble destruction-mediated CMB-shRNA-IGFBPrP1 delivery, or inhibition of the Hedgehog (Hh) pathway by cyclopamine treatment, was performed in TAA-induced liver fibrosis mice. Hepatic fibrosis was determined by hematoxylin and eosin and Sirius red staining. Hepatic expression of IGFBPrP1, α-smooth muscle actin (α-SMA), transforming growth factor β 1 (TGFβ1), collagen I, MMPs/TIMPs, Sonic Hedgehog (Shh), and glioblastoma family transcription factors (Gli1) were investigated by immunohistochemical staining and Western blotting analysis.

RESULTS

We found that hepatic expression of IGFBPrP1, TGFβ1, α-SMA, and collagen I were increased longitudinally in mice with TAA-induced hepatic fibrosis, concomitant with MMP2/TIMP2 and MMP9/TIMP1 imbalance and Hh pathway activation. Knockdown of IGFBPrP1 expression, or inhibition of the Hh pathway, reduced the hepatic expression of IGFBPrP1, TGFβ1, α-SMA, and collagen I and re-established MMP2/TIMP2 and MMP9/TIMP1 balance.

CONCLUSIONS

Our findings suggest that IGFBPrP1 knockdown attenuates liver fibrosis by re-establishing MMP2/TIMP2 and MMP9/TIMP1 balance, concomitant with the inhibition of hepatic stellate cell activation, down-regulation of TGFβ1 expression, and degradation of the ECM. Furthermore, the Hh pathway mediates IGFBPrP1 knockdown-induced attenuation of hepatic fibrosis through the regulation of MMPs/TIMPs balance.