scholarly journals Chitinase 3-like 1 is a profibrogenic factor overexpressed in the aging liver and in patients with liver cirrhosis

2021 ◽  
Vol 118 (17) ◽  
pp. e2019633118
Author(s):  
Norihisa Nishimura ◽  
Davide De Battista ◽  
David R. McGivern ◽  
Ronald E. Engle ◽  
Ashley Tice ◽  
...  
Keyword(s):  
Gene Expression ◽  
Liver Fibrosis ◽  
Liver Tissue ◽  
Messenger Rna ◽  
Normal Liver ◽  
In Vitro Models ◽  
Hepatitis D ◽  
Fibrosis Progression ◽  
Increased Risk

Older age at the time of infection with hepatitis viruses is associated with an increased risk of liver fibrosis progression. We hypothesized that the pace of fibrosis progression may reflect changes in gene expression within the aging liver. We compared gene expression in liver specimens from 54 adult donors without evidence of fibrosis, including 36 over 40 y old and 18 between 18 and 40 y old. Chitinase 3-like 1 (CHI3L1), which encodes chitinase-like protein YKL-40/CHI3L1, was identified as the gene with the greatest age-dependent increase in expression in liver tissue. We investigated the cellular source of CHI3L1 in the liver and its function using liver tissue specimens and in vitro models. CHI3L1 expression was significantly higher in livers of patients with cirrhosis of diverse etiologies compared with controls represented by patients who underwent liver resection for hemangioma. The highest intrahepatic CHI3L1 expression was observed in cirrhosis due to hepatitis D virus, followed by hepatitis C virus, hepatitis B virus, and alcohol-induced cirrhosis. In situ hybridization of CHI3L1 messenger RNA (mRNA) identified hepatocytes as the major producers of CHI3L1 in normal liver and in cirrhotic tissue, wherein hepatocytes adjacent to fibrous septa showed higher CHI3L1 expression than did those in more distal areas. In vitro studies showed that recombinant CHI3L1 promotes proliferation and activation of primary human hepatic stellate cells (HSCs), the major drivers of liver fibrosis. These findings collectively demonstrate that CHI3L1 promotes liver fibrogenesis through a direct effect on HSCs and support a role for CHI3L1 in the increased susceptibility of aging livers to fibrosis progression.

scholarly journals Ruxolitinib Suppresses Liver Fibrosis Progression and Accelerates Fibrosis Reversal via Selectively Targeting Janus Kinase 1/2

2021 ◽  
Author(s):  
Zhenghui Song ◽  
Xinhui Liu ◽  
Wan Zhang ◽  
Yue Luo ◽  
Hua Xiao ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Liver Tissue ◽  
Cell Damage ◽  
Underlying Mechanism ◽  
Janus Kinase ◽  
Human Liver Tissue ◽  
Downstream Signaling ◽  
Fibrosis Progression ◽  
And Migration

Abstract BackgroundJAK1 and JAK2 have been implicated in fibrosis and cancer as a fibroblast-related marker; however, their role in liver fibrosis has not been elucidated. Here, we aim to determine the effect and underlying mechanism of JAK1/2 inhibition on liver fibrosis and hepatic stellate cells (HSCs) and further explore the therapeutic efficacy of Ruxolitinib, a JAK1/2 selective inhibitor, on preventing and reversing liver fibrosis in mice. MethodsImmunohistochemistry staining of JAK1 and JAK2 were performed on liver tissue in mice with hepatic fibrosis and human liver tissue microarray of liver cirrhosis and liver cancer. LX-2 cells treated with specific siRNA of JAK1 and JAK2 were used to analysis activation, proliferation and migration of HSCs regulated by JAK1/2. The effects of Ruxolitinib (JAK1/2 inhibitor) on liver fibrosis were studied in LX-2 cells and two progressive and reversible fibrosis animal models (carbon tetrachloride (CCl4), Thioacetamide (TAA)). ResultsWe found that JAK1/2 expression was positively correlated with the progression of HCC in humans and the levels of liver fibrosis in mice. Silencing of JAK1/2 down-regulated their downstream signaling and inhibited proliferation, migration, and activation of HSCs in vitro, while Ruxolitinib had similar effects on HSCs. Importantly, Ruxolitinib significantly attenuated fibrosis progression, improved cell damage, and accelerated fibrosis reversal in the liver of mice treated with CCl 4 or TAA. ConclusionsJAK1/2 regulates the function of HSCs and plays an essential role in liver fibrosis and HCC development. Its inhibitor, Ruxolitinib, may be an effective drug for preventing and treating liver fibrosis.

scholarly journals Differential Effects of Gonadotropin-Releasing Hormone (GnRH) Pulse Frequency on Gonadotropin Subunit and GnRH Receptor Messenger Ribonucleic Acid Levels in Vitro*

Endocrinology ◽  
1997 ◽  
Vol 138 (3) ◽  
pp. 1224-1231 ◽  
Author(s):  
Ursula B. Kaiser ◽  
Andrzej Jakubowiak ◽  
Anna Steinberger ◽  
William W. Chin
Keyword(s):  
Gene Expression ◽  
Messenger Rna ◽  
Pulse Frequency ◽  
Gnrh Receptor ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Subunit Gene ◽  
Differential Effects ◽  
Messenger Ribonucleic Acid

Abstract The hypothalamic hormone, GnRH, is released and transported to the anterior pituitary in a pulsatile manner, where it binds to specific high-affinity receptors and regulates gonadotropin biosynthesis and secretion. The frequency of GnRH pulses changes under various physiological conditions, and varying GnRH pulse frequencies have been shown to regulate differentially the secretion of LH and FSH and the expression of the gonadotropin α, LHβ, and FSHβ subunit genes in vivo. We demonstrate differential effects of varying GnRH pulse frequency in vitro in superfused primary monolayer cultures of rat pituitary cells. Cells were treated with 10 nm GnRH pulses for 24 h at a frequency of every 0.5, 1, 2, or 4 h. α, LHβ, and FSHβ messenger RNA (mRNA) levels were increased by GnRH at all pulse frequencies. α and LHβ mRNA levels and LH secretion were stimulated to the greatest extent at a GnRH pulse frequency of every 30 min, whereas FSHβ mRNA levels and FSH secretion were stimulated maximally at a lower GnRH pulse frequency, every 2 h. GnRH receptor (GnRHR) mRNA levels also were increased by GnRH at all pulse frequencies and were stimulated maximally at a GnRH pulse frequency of every 30 min. Similar results were obtained when the dose of each pulse of GnRH was adjusted to maintain a constant total cumulative dose of GnRH over 24 h. These data show that gonadotropin subunit gene expression is regulated differentially by varying GnRH pulse frequencies in vitro, suggesting that the differential effects of varying GnRH pulse frequencies on gonadotropin subunit gene expression occur directly at the level of the pituitary. The pattern of regulation of GnRHR mRNA levels correlated with that of α and LHβ but was different from that of FSHβ. This suggests that α and LHβ mRNA levels are maximally stimulated when GnRHR levels are relatively high, whereas FSHβ mRNA levels are maximally stimulated at lower levels of GnRHR expression, and that the mechanism for differential regulation of the gonadotropins by varying pulse frequencies of GnRH may involve levels of GnRHR. Furthermore, these data suggest that the mechanisms whereby varying GnRH pulse frequencies stimulate α, LHβ, and GnRHR gene expression are similar, whereas the stimulation of FSHβ mRNA levels may be different.

scholarly journals Identification of GDF15 as A Pro-Fibrotic Factor in Mouse Liver Fibrosis Progression

2021 ◽  
Author(s):  
Peng Qi ◽  
Ming-Ze Ma ◽  
Jing-Hua Kuai
Keyword(s):  
Carbon Tetrachloride ◽  
Liver Fibrosis ◽  
Hepatic Stellate Cell ◽  
Hepatic Stellate Cells ◽  
Liver Tissue ◽  
Cell Activation ◽  
Stellate Cell ◽  
Neutralizing Antibody ◽  
Stellate Cells ◽  
Fibrosis Progression

Abstract Aim:To elucidate the inhibitory role of growth differentiation factor 15 (GDF15) in liver fibrosis and its possible activation mechanism in hepatic stellate cells of mice.Methods:We generated a GDF15-neutralizing antibody that can inhibit TGF-β1-induced activation of the TGF-β/Smad2/3 pathway in LX-2 cells. All the mice in this study were induced by carbon tetrachloride and thioacetamide. In addition, primary hepatic stellate cells from mice were isolated from fresh livers using Nycodenz density gradient separation. The severity and extent of liver fibrosis in mice were evaluated by Sirius Red and Masson staining. The effect of GDF15 on the activation of the TGF-β pathway was detected using dual-luciferase reporter assays and Western blotting assays.Results:The expression of GDF15 in cirrhotic liver tissue was higher than that in normal liver tissue. Blocking GDF15 with a neutralizing antibody resulted in a delay in primary hepatic stellate cell activation and remission of liver fibrosis induced by carbon tetrachloride or thioacetamide. Meanwhile, TGF-β pathway activation was partly inhibited by a GDF15-neutralizing antibody in primary hepatic stellate cells. These results indicated that GDF15 plays an important role in regulating HSC activation and liver fibrosis progression.Conclusions:The inhibition of GDF15 attenuates chemical-inducible liver fibrosis and delays hepatic stellate cell activation, and this effect is probably mainly attributed to its regulatory role in TGF-β signalling.

scholarly journals Absence of leptin expression and secretion by human luteinized granulosa cells

2003 ◽  
Vol 31 (1) ◽  
pp. 233-239 ◽  
Author(s):  
M Karamouti ◽  
P Kollia ◽  
E Karligiotou ◽  
A Kallitsaris ◽  
N Prapas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Granulosa Cells ◽  
Messenger Rna ◽  
Limit Of Detection ◽  
Culture Media ◽  
Point Of View ◽  
In Vitro Fertilisation ◽  
Ob Gene ◽  
Human Granulosa Cells

Whether leptin is secreted by the human ovary is not known. The available data on leptin gene (ob gene) expression by human granulosa cells are conflicting. The aim of the present study was first to re-examine the expression of leptin messenger RNA (mRNA) by human granulosa cells and second to investigate if these cells have the ability to secrete leptin in cultures. Human luteinized granulosa cells were obtained from normal women undergoing in vitro fertilisation treatment after ovarian stimulation and follicle aspiration. The expression of ob gene was studied by Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) both in primary granulosa cells treated immediately after oocyte recovery and in cells cultured up to 24 h under baseline and hormonally stimulated conditions (FSH: 100 ng/ml, LH: 100 ng/ml). ob mRNA transcripts were not detected in luteinized granulosa cells, while they were present in adipose tIssue cDNA. Actin gene expression was detected in all studied samples. Using a sensitive radioimmunoassay (lower limit of detection 0.05 ng/ml), leptin was undetectable in the culture media at all points during the 72 h cultures, while at the same time significant amounts of oestradiol and progesterone were produced particularly after the addition of androstendione (1 microM) to the incubation media. These results demonstrate for the first time that leptin is not secreted by human luteinized granulosa cells in cultures. From a physiological point of view, this may contribute to the development of the optimal follicular environment for oocyte maturation during the preovulatory period.

scholarly journals Hydrogels for Liver Tissue Engineering

2019 ◽  
Vol 6 (3) ◽  
pp. 59 ◽  
Author(s):  
Shicheng Ye ◽  
Jochem W.B. Boeter ◽  
Louis C. Penning ◽  
Bart Spee ◽  
Kerstin Schneeberger
Keyword(s):  
Tissue Engineering ◽  
Liver Tissue ◽  
Drug Testing ◽  
In Vitro Models ◽  
Liver Tissue Engineering ◽  
Synthetic Materials ◽  
Toxicological Studies ◽  
End Stage

Bioengineered livers are promising in vitro models for drug testing, toxicological studies, and as disease models, and might in the future be an alternative for donor organs to treat end-stage liver diseases. Liver tissue engineering (LTE) aims to construct liver models that are physiologically relevant. To make bioengineered livers, the two most important ingredients are hepatic cells and supportive materials such as hydrogels. In the past decades, dozens of hydrogels have been developed to act as supportive materials, and some have been used for in vitro models and formed functional liver constructs. However, currently none of the used hydrogels are suitable for in vivo transplantation. Here, the histology of the human liver and its relationship with LTE is introduced. After that, significant characteristics of hydrogels are described focusing on LTE. Then, both natural and synthetic materials utilized in hydrogels for LTE are reviewed individually. Finally, a conclusion is drawn on a comparison of the different hydrogels and their characteristics and ideal hydrogels are proposed to promote LTE.

scholarly journals Evaluation of NV556, a Novel Cyclophilin Inhibitor, as a Potential Antifibrotic Compound for Liver Fibrosis

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1409 ◽  
Author(s):  
Sonia Simón Serrano ◽  
Alvar Grönberg ◽  
Lisa Longato ◽  
Krista Rombouts ◽  
Joseph Kuo ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Stellate Cell ◽  
Unmet Need ◽  
Potential Candidate ◽  
In Vivo Models ◽  
Fibrotic Process ◽  
Increased Risk ◽  
Cyclophilin Inhibitor

Hepatic fibrosis can result as a pathological response to nonalcoholic steatohepatitis (NASH). Cirrhosis, the late stage of fibrosis, has been linked to poor survival and an increased risk of developing hepatocellular carcinoma, with limited treatment options available. Therefore, there is an unmet need for novel effective antifibrotic compounds. Cyclophilins are peptidyl-prolyl cis-trans isomerases that facilitate protein folding and conformational changes affecting the function of the targeted proteins. Due to their activity, cyclophilins have been presented as key factors in several stages of the fibrotic process. In this study, we investigated the antifibrotic effects of NV556, a novel potent sanglifehrin-based cyclophilin inhibitor, in vitro and in vivo. NV556 potential antifibrotic effect was evaluated in two well-established animal models of NASH, STAM, and methionine-choline-deficient (MCD) mice, as well as in an in vitro 3D human liver ECM culture of LX2 cells, a human hepatic stellate cell line. We demonstrate that NV556 decreased liver fibrosis in both STAM and MCD in vivo models and decreased collagen production in TGFβ1-activated hepatic stellate cells in vitro. Taken together, these results present NV556 as a potential candidate for the treatment of liver fibrosis.

scholarly journals Fighting Liver Fibrosis with Naturally Occurring Antioxidants

Planta Medica ◽  
2018 ◽  
Vol 84 (18) ◽  
pp. 1318-1333 ◽  
Author(s):  
Ligen Lin ◽  
Fayang Zhou ◽  
Shengnan Shen ◽  
Tian Zhang
Keyword(s):  
Oxidative Stress ◽  
Liver Fibrosis ◽  
Normal Liver ◽  
Natural Antioxidants ◽  
In Vivo Studies ◽  
Lead Compounds ◽  
Naturally Occurring ◽  
Wound Healing Response

AbstractLiver fibrosis is a wound-healing response characterized by the accumulation of extracellular matrix following various liver injuries, which results in the deformation of the normal liver architecture and the development of liver cirrhosis and even hepatocellular carcinoma. Numerous in vitro and in vivo studies indicated that oxidative stress mediates the initiation and progression of liver fibrosis. Overaccumulation of reactive oxygen species disrupts macromolecules, induces necrosis and apoptosis of hepatocytes, stimulates the production of pro-fibrogenic mediators, and directly activates hepatic stellate cells, thereby resulting in liver damage and initiating liver fibrosis. Ameliorating oxidative stress is a potential therapeutic strategy for the treatment of liver fibrosis. Natural antioxidants have attracted increasing attention in treating liver fibrosis due to their safety and efficacy. In this review, the pathogenesis of liver fibrosis and the role of oxidative stress in liver fibrosis were discussed. Naturally occurring antioxidants that can treat and prevent liver fibrosis were summarized. Advances in clinical trials were also presented. The main purpose of this review is to provide a comprehensive and up-to-date knowledge from the biological importance of oxidative stress in liver fibrosis to representative antioxidants for treating liver fibrosis. Naturally occurring antioxidants show a potential for further investigations as lead compounds in fighting liver fibrosis.

LIVER TISSUE MODEL FOR DRUG TOXICITY SCREENING

2011 ◽  
Vol 11 (02) ◽  
pp. 369-390 ◽  
Author(s):  
CHUKWUEMEKA ANENE-NZELU ◽  
YAN WANG ◽  
HANRY YU ◽  
LEO HWA LIANG
Keyword(s):  
Liver Tissue ◽  
Drug Testing ◽  
Normal Liver ◽  
3D Models ◽  
New Drugs ◽  
Toxicity Screening ◽  
Cell Sources ◽  
Current Shift ◽  
And Function

Understanding the mechanisms involved in the biotransformation of new drugs and their toxicological implications is important for drug development. In this regard, a lot of effort has been put into research to recreate the liver tissue in the laboratory for the purpose of drug screening. This has also helped to minimize the use of laboratory animal and reduce incidence of post-market withdrawal of drugs. Despite the progress made so far, cell source remains a major limitation since primary human hepatocytes are scarce and the various cell alternatives do not express all the genes found in the normal liver. In terms of tissue construct, there is a current shift to 3D models since the cell–cell interactions found in the 3D configuration enhance the morphology and function of hepatocytes. Furthermore, the engineered tissue's performance can be optimized by cocultures, perfusion-based systems, and the use of scaffolds. Nanotechnology seems promising in the field of tissue engineering, as it has been proven that cell–matrix interactions at the nano level can influence greatly on the outcome of the tissue. The review explores the various cell sources, the 3D model, flow-based systems, cocultures, and nanoscaffolds use in hepatocytes in vitro drug testing

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