Hepatic fibrosis -- overview

Cold and hot fibrosis define clinically distinct cardiac pathologies

Fibrosis remains a major unmet medical need. Simplifying principles are needed to better understand fibrosis and to yield new therapeutic approaches. Fibrosis is driven by myofibroblasts that interact with macrophages. A mathematical cell-circuit model predicts two types of fibrosis: hot fibrosis driven by macrophages and myofibroblasts and cold fibrosis driven by myofibroblasts alone. Testing these concepts in cardiac fibrosis resulting from myocardial infarction (MI) and heart failure (HF), we revealed that acute MI leads to cold fibrosis whereas chronic injury (HF) leads to hot fibrosis. MI-driven cold fibrosis is conserved in pigs and humans. We computationally identified a vulnerability of cold fibrosis: the myofibroblast autocrine growth factor loop. Inhibiting this loop by targeting TIMP1 with neutralizing antibodies reduced myofibroblast proliferation and fibrosis post-MI in mice. Our study demonstrates the utility of the concepts of hot and cold fibrosis and the feasibility of a circuit-to-target approach to pinpoint a treatment strategy that reduces fibrosis. A record of this paper's transparent peer review process is included in the supplemental information.

Recent advances in small molecule design strategies against hepatic fibrosis

Hepatic fibrosis, a widespread pathological process observed across various liver diseases, is acknowledged as a potentially reversible condition. In recent years, liver fibrosis has garnered extensive research attention, with a primary emphasis on developing drugs that can directly block or reverse this condition. This paper presents a comprehensive review of the design strategies for various anti-hepatic fibrosis agents that have been many efficacious small-molecule drugs. This review encompasses the synthesis and design of nuclear receptor ligands (such as VDR and Nurr7), kinase inhibitors (including ALK5 and JAK1), selective PDE inhibitors, small-molecule monomers derived from natural products, and other small molecules. The aim of this review is to provide promising avenues and valuable insights for the continued development of anti-hepatic fibrosis drugs.

Hepatoprotective action mechanism and quantification of soyasaponin Bb in Abri Herba by HPLC and network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

The herb of Abrus cantoniensis Hance (AC) is an important Traditional Chinese Medicine (TCM) and is also used as an herbal tea with hepatoprotective action. Soyasaponin Bb is one of the pharmacodynamic substances of AC for the herb's effective pharmacological activity. This study aims to investigate the anti-fibrotic and hepatoprotective activities of soyasaponin Bb in vivo and in vitro experiments, mechanism by network pharmacology and quantification by HPLC.

MATERIALS AND METHODS

High-performance liquid chromatography (HPLC) was applied to evaluate the quality of the herb and determine the contents of soyasaponin Bb from different sources and parts of the AC. In vivo experiments were conducted to induce an acute liver injury model by injecting CCl4 into mice, and an in vitro hepatic fibrosis model was established by cultivating LX-2 cells with TGF-β1. These models were used to explore the anti-fibrotic and hepatoprotective effects of soyasaponin Bb and its underlying mechanisms. In addition, the potential target genes corresponding to soyasaponin Bb were identified using the Swiss Target Prediction database through network pharmacology methods. Meanwhile, hepatic fibrosis targets were screened using the GeneCards, TTD, and OMIM disease databases. The STING database was used to construct the protein-protein interaction (PPI) network of soyasaponin Bb-hepatic fibrosis. The soyasaponin Bb-hepatic fibrosis disease target-pathway network was constructed using Cytoscape 3.9.1 software. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to enrich and analyze the common targets of the drug and the disease, aiming to identify the potential targets and pathways involved in the anti-fibrotic and hepatoprotective effects of soyasaponin Bb.

RESULTS

The content of soyasaponin Bb varied across different sources, with the roots containing the highest concentration, up to 0.2480%. In vivo experiments showed that soyasaponin Bb had a protective effect against CCl4-induced acute liver injury, effectively inhibiting the increase in ALT and AST levels and slowing down the hepatocyte inflammatory damage caused by CCl4. Soyasaponin Bb also down-regulated MDA levels and up-regulated SOD levels, indicating a certain antioxidant capacity. In vitro cell experiments showed that soyasaponin Bb could effectively inhibit the proliferation of HSC-LX2 cells induced by TGF-β1 by regulating the TGF-β1/α-SMA pathway, significantly down-regulate the protein expression of TGF-β1 and α-SMA, while also reducing the levels of inflammatory cytokines IL-6 and IL-1β. Further network pharmacology analysis suggested that soyasaponin Bb can exert anti-fibrosis activity by regulating the IBD signaling pathway, Th17 signaling pathway, Hepatitis B signaling pathway, and JAK-STAT signaling pathway.

CONCLUSION

Soyasaponin Bb is primarily distributed in the root of AC, and it has a strong protective effect against CCl4-induced acute liver injury. It can reduce the level of inflammatory factors, relieve inflammation, and exert anti-fibrotic activity by regulating the TGF-β1/α-SMA pathway. Its potential anti-hepatic fibrosis mechanism has been investigated through network pharmacology.

The role of macrophage-derived exosomes in noncancer liver diseases: From intercellular crosstalk to clinical potential

Chronic liver disease has a substantial global prevalence and mortality rate. Macrophages, pivotal cells in innate immunity, exhibit remarkable heterogeneity and plasticity and play a considerable role in maintaining organ homeostasis, modulating inflammatory responses, and influencing disease progression in the liver. Exosomes, which can serve as conduits for intercellular communication, biomarkers, and therapeutic targets for a spectrum of diseases, have recently garnered increasing attention recently. Given that the liver is the organ with the highest macrophage content, a thorough understanding of the influence of macrophage-derived exosomes (MDEs) on noncancer liver disease pathogenesis and their potential therapeutic applications is paramount. Interactions among MDEs, hepatocytes, hepatic stellate cells (HSCs), and other nonparenchymal cells constitute a complex network regulates liver immune homeostasis. In this review, we summarize the latest progress in the current understanding of MDE heterogeneity and cellular crosstalk in noncancer liver diseases, as well as their potential clinical applications. Additionally, challenges and future directions are underscored.

Engineered SPIONs functionalized with endothelin a receptor antagonist ameliorate liver fibrosis by inhibiting hepatic stellate cell activation

Endothelin-1/endothelin A receptor (ET-1/ETAR) pathway plays an important role in the progression of liver fibrosis by activating hepatic stellate cells (HSCs) - a key cell type involved in the pathogenesis of liver fibrosis. Inactivating HSCs by blocking the ET-1/ETAR pathway using a selective ETAR antagonist (ERA) represents a promising therapeutic approach for liver fibrosis. Unfortunately, small-molecule ERAs possess limited clinical potential due to poor bioavailability, short half-life, and rapid renal clearance. To improve the clinical applicability, we conjugated ERA to superparamagnetic iron-oxide nanoparticles (SPIONs) and investigated the therapeutic efficacy of ERA and ERA-SPIONs in vitro and in vivo and analyzed liver uptake by in vivo and ex vivo magnetic resonance imaging (MRI), HSCs-specific localization, and ET-1/ETAR-pathway antagonism in vivo. In murine and human liver fibrosis/cirrhosis, we observed overexpression of ET-1 and ETAR that correlated with HSC activation, and HSC-specific localization of ETAR. ERA and successfully synthesized ERA-SPIONs demonstrated significant attenuation in TGFβ-induced HSC activation, ECM production, migration, and contractility. In an acute CCl4-induced liver fibrosis mouse model, ERA-SPIONs exhibited higher liver uptake, HSC-specific localization, and ET-1/ETAR pathway antagonism. This resulted in significantly reduced liver-to-body weight ratio, plasma ALT levels, and α-SMA and collagen-I expression, indicating attenuation of liver fibrosis. In conclusion, our study demonstrates that the delivery of ERA using SPIONs enhances the therapeutic efficacy of ERA in vivo. This approach holds promise as a theranostic strategy for the MRI-based diagnosis and treatment of liver fibrosis.

Advancements of non‐invasive imaging technologies for the diagnosis and staging of liver fibrosis: Present and future

Liver fibrosis is a reparative response triggered by liver injury. Non‐invasive assessment and staging of liver fibrosis in patients with chronic liver disease are of paramount importance, as treatment strategies and prognoses depend significantly on the degree of fibrosis. Although liver fibrosis has traditionally been staged through invasive liver biopsy, this method is prone to sampling errors, particularly when biopsy sizes are inadequate. Consequently, there is an urgent clinical need for an alternative to biopsy, one that ensures precise, sensitive, and non‐invasive diagnosis and staging of liver fibrosis. Non‐invasive imaging assessments have assumed a pivotal role in clinical practice, enjoying growing popularity and acceptance due to their potential for diagnosing, staging, and monitoring liver fibrosis. In this comprehensive review, we first delved into the current landscape of non‐invasive imaging technologies, assessing their accuracy and the transformative impact they have had on the diagnosis and management of liver fibrosis in both clinical practice and animal models. Additionally, we provided an in‐depth exploration of recent advancements in ultrasound imaging, computed tomography imaging, magnetic resonance imaging, nuclear medicine imaging, radiomics, and artificial intelligence within the field of liver fibrosis research. We summarized the key concepts, advantages, limitations, and diagnostic performance of each technique. Finally, we discussed the challenges associated with clinical implementation and offer our perspective on advancing the field, hoping to provide alternative directions for the future research.

Linking fatty liver diseases to hepatocellular carcinoma by hepatic stellate cells

Hepatic stellate cells (HSCs), a distinct category of non-parenchymal cells in the liver, are critical for liver homeostasis. In healthy livers, HSCs remain non-proliferative and quiescent. However, under conditions of acute or chronic liver damage, HSCs are activated and participate in the progression and regulation of liver diseases such as liver fibrosis, cirrhosis, and liver cancer. Fatty liver diseases (FLD), including nonalcoholic (NAFLD) and alcohol-related (ALD), are common chronic inflammatory conditions of the liver. These diseases, often resulting from multiple metabolic disorders, can progress through a sequence of inflammation, fibrosis, and ultimately, cancer. In this review, we focused on the activation and regulatory mechanism of HSCs in the context of FLD. We summarized the molecular pathways of activated HSCs (aHSCs) in mediating FLD and their role in promoting liver tumor development from the perspectives of cell proliferation, invasion, metastasis, angiogenesis, immunosuppression, and chemo-resistance. We aimed to offer an in-depth discussion on the reciprocal regulatory interactions between FLD and HSC activation, providing new insights for researchers in this field.

Identification of functional genes in liver fibrosis based on bioinformatics analysis of a lncRNA-mediated ceRNA network

BACKGROUND

Liver fibrosis is a major global healths problem; nevertheless, its molecular mechanism are not completely clear. This study aimed to build a lncRNA-miRNA-mRNA network, identify potentially related lncRNAs, and explore the pathogenesis of liver fibrosis.

MATERIALS AND METHODS

We used the Gene Expression Omnibus databases and bioinformatics analysis to identify differentially expressed genes (DEGs) between liver fibrosis and normal tissues. The ceRNA network was constructed according to the interactions between DElncRNA, miRNA, and DEmRNA. Then, these DEGs were identified using functional enrichment analysis, and a protein-protein interaction (PPI) network was established. The critical lncRNAs were verified using the quantitative real-time polymerase chain reaction (qRT-PCR).

RESULTS

The ceRNA network was composed of three lncRNAs, five miRNAs, and 93 mRNAs. Gene Ontology functional enrichment analysis revealed significant enhancement in cell components, molecular function, and biological process. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed pathways associated with transcriptional misregulation in cancer, including the Rap1 signaling pathway, proteoglycans in cancer, mineral absorption, HTLV-l infection, and central carbon metabolism in cancer. According to the PPI network and the GSE84044 database, seven hub genes associated with liver fibrosis were identified. In addition, qRT-PCR revealed that lncRNA AC100861 (lncRNA TNFRSF10A-DT) was explicitly decreased in liver fibrosis tissues and activated hepatic stellate cells.

CONCLUSIONS

In summary, this study preliminarily found that lncRNA TNFRSF10A-DT may be a biomarker for the diagnosis and outcome of liver fibrosis. We uncovered a novel lncRNA-mediated ceRNA regulatory mechanism in the pathogenesis of liver fibrosis.

Isolation and Biological Evaluation of Alfa-Mangostin as Potential Therapeutic Agents against Liver Fibrosis

The increased proliferation and activation of hepatic stellate cells (HSCs) are associated with liver fibrosis development. To date, there are no FDA-approved drugs for the treatment of liver cirrhosis. Augmentation of HSCs apoptosis is one of the resolutions for liver fibrosis. In this study, we extracted α-mangostin (1,3,6-trihydroxy-7-methoxy-2,8-bis(3-methyl-2-butenyl)-9H-xanthen-9-one) from the fruit waste components of mangosteen pericarp. The isolated α-mangostin structure was determined and characterized with nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HRMS) and compared with those known compounds. The intracellular signaling pathway activities of α-mangostin on Transforming growth factors-beta 1 (TGF-β1) or Platelet-derived growth factor subunit B (PDGF-BB) induced HSCs activation and were analyzed via Western blot and Real-time Quantitative Polymerase Chain Reaction (Q-PCR). α-Mangostin-induced mitochondrial dysfunction and apoptosis in HSCs were measured by seahorse assay and caspase-dependent cleavage. The in vivo anti-fibrotic effect of α-mangostin was assessed by carbon tetrachloride (CCl4) treatment mouse model. The data showed that α-mangostin treatment inhibited TGF-β1-induced Smad2/3 phosphorylation and alpha-smooth muscle actin (α-SMA) expression in HSCs in a dose-dependent manner. Regarding the PDGF-BB-induced HSCs proliferation signaling pathways, α-mangostin pretreatment suppressed the phosphorylation of extracellular-signal-regulated kinase (ERK) and p38. The activation of caspase-dependent apoptosis and dysfunction of mitochondrial respiration (such as oxygen consumption rate, ATP production, and maximal respiratory capacity) were observed in α-mangostin-treated HSCs. The CCl4-induced liver fibrosis mouse model showed that the administration of α-mangostin significantly decreased the expression of the fibrosis markers (α-SMA, collagen-a2 (col1a2), desmin and matrix metalloproteinase-2 (MMP-2)) as well as attenuated hepatic collagen deposition and liver damage. In conclusion, this study demonstrates that α-mangostin attenuates the progression of liver fibrosis through inhibiting the proliferation of HSCs and triggering apoptosis signals. Thus, α-mangostin may be used as a potential novel therapeutic agent against liver fibrosis.

Mining host candidate regulators of schistosomiasis-induced liver fibrosis in response to artesunate therapy through transcriptomics approach

BACKGROUND

Artesunate (ART) has been reported to have an antifibrotic effect in various organs. The underlying mechanism has not been systematically elucidated. We aimed to clarify the effect of ART on liver fibrosis induced by Schistosoma japonicum (S. japonicum) in an experimentally infected rodent model and the potential underlying mechanisms.

METHODS

The effect of ART on hepatic stellate cells (HSCs) was assessed using CCK-8 and Annexin V-FITC/PI staining assays. The experimental model of liver fibrosis was established in the Mongolian gerbil model infected with S. japonicum cercariae and then treated with 20 mg/kg or 40 mg/kg ART. The hydroxyproline (Hyp) content, malondialdehyde (MDA) content, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities in liver tissue were measured and histopathological changes of liver tissues were observed. Whole-transcriptome RNA sequencing (RNA-seq) of the liver tissues was performed. Differentially expressed genes (DEGs) were identified using bioinformatic analysis and verified by quantitative PCR (qPCR) and western blot assay.

RESULTS

ART significantly inhibited the proliferation and induce the apoptosis of HSCs in a dose-dependent manner. In vivo, Hyp content decreased significantly in the ART-H group compared to the model (MOD) group and GPX activity was significantly higher in the ART-H group than in the MOD group. Besides, ART treatment significantly reduced collagen production (p <0.05). A total of 158 DEGs and 44 differentially expressed miRNAs related to ART-induced anti-schistosomiasis liver fibrosis were identified. The qPCR and western blot results of selected DEGs were consistent with the sequencing results. These DEGs were implicated in key pathways such as immune and inflammatory response, integrin-mediated signaling and toll-like receptor signaling pathways.

CONCLUSION

ART is effective against liver fibrosis using Mongolian gerbil model induced by S. japonicum infection. We identified host candidate regulators of schistosomiasis-induced liver fibrosis in response to ART through transcriptomics approach.

Advancements in Research on Constructing Physiological and Pathological Liver Models and Their Applications Utilizing Bioprinting Technology

In recent decades, significant progress has been made in liver tissue engineering through the use of 3D bioprinting technology. This technology offers the ability to create personalized biological structures with precise geometric design capabilities. The complex and multifaceted nature of liver diseases underscores the need for advanced technologies to accurately mimic the physiological and mechanical characteristics, as well as organ-level functions, of liver tissue in vitro. Bioprinting stands out as a superior option over traditional two-dimensional cell culture models and animal models due to its stronger biomimetic advantages. Through the use of bioprinting, it is possible to create liver tissue with a level of structural and functional complexity that more closely resembles the real organ, allowing for more accurate disease modeling and drug testing. As a result, it is a promising tool for restoring and replacing damaged tissue and organs in the field of liver tissue engineering and drug research. This article aims to present a comprehensive overview of the progress made in liver tissue engineering using bioprinting technology to provide valuable insights for researchers. The paper provides a detailed account of the history of liver tissue engineering, highlights the current 3D bioprinting methods and bioinks that are widely used, and accentuates the importance of existing in vitro liver tissue models based on 3D bioprinting and their biomedical applications. Additionally, the article explores the challenges faced by 3D bioprinting and predicts future trends in the field. The progress of 3D bioprinting technology is poised to bring new approaches to printing liver tissue in vitro, while offering powerful tools for drug development, testing, liver disease modeling, transplantation, and regeneration, which hold great academic and practical significance.

Discovery and development of benzene sulfonamide derivatives as anti-hepatic fibrosis agents

A novel benzene sulfonamide compound named IMB16-4 exhibits excellent anti-hepatic fibrosis activity in a recent study. To develop potential anti-hepatic fibrosis agents, a series of benzene sulfonamide derivatives were designed and synthesized based on the scaffold of the lead compound IMB16-4. As it turned out, most of the derivatives displayed potential anti-hepatic fibrosis activity, among which, compounds 11a, 11b, 11d, 13a, 36b, and 47b exhibited inhibition rates of 42.3%, 48.7%, 42.4%, 40.0%, 39.4%, and 49.3%, respectively, which were equivalent to the control IMB16-4 with an inhibition rate of 35.9%, Costunolide with an inhibition rate of 45.4%, and much more potent than that of Epigallocatechin gallate (EGCG) with an inhibition rate of 25.3%. Especially, compounds 46a, 46b, and 46c exhibited excellent anti-hepatic fibrosis activity with inhibition rates of 61.7%, 54.8%, and 60.7%, which were almost 1.5-fold inhibition rates of IMB16-4. In addition, compounds 46a, 46b, and 46c exhibited remarkable inhibitory activity in the gene expression of COL1A1, MMP-2, and the protein expression of COL1A1, FN, α-SMA, and TIMP-1 by inhibiting the JAK1-STAT1/3 pathway. These findings furnished valuable inspiration for the further development of anti-hepatic fibrosis agents.

TKF, a mexicanolide-type limonoid derivative, suppressed hepatic stellate cells activation and liver fibrosis through inhibition of the YAP/Notch3 pathway

BACKGROUND

Liver fibrosis is a common scarring response and may ultimately lead to liver cancer, unfortunately, there is currently no effective antifibrotic drug approved for human use. Limonoids exhibit a broad spectrum of biological activities; however, the potential role of limonoids against fibrosis is largely unknown.

PURPOSE

This study investigates the antifibrotic activities and potential mechanisms of TKF (3-tigloyl-khasenegasin F), a natural mexicanolide-type limonoid derivative.

STUDY DESIGN/METHODS

Two well-established mouse models (CCl₄ challenge and bile duct ligation) were used to assess anti-fibrotic effects of TKF in vivo. Human hepatic stellate cell (HSC) line LX-2 and mouse primary hepatic stellate cells (pHSCs) also served as in vitro liver fibrosis models.

RESULT

TKF administration significantly attenuated hepatic histopathological injury and collagen accumulation and suppressed fibrogenesis-associated gene expression including Col1a1, Acta2, and Timp1. In LX-2 cells and mouse pHSCs, TKF dose-dependently suppressed HSC activation and the expression levels of fibrogenic markers. Mechanistic studies showed that TKF inhibited Notch3-Hes1 and YAP signalings in vivo and in vitro. Furthermore, YAP inhibition or knockdown downregulated the Notch3 expression; however, Notch3 inhibition or knockdown did not affect the level of YAP in activated HSC. We revealed that TKF inhibited Notch3-Hes1 activation and downregulated hepatic fibrogenic gene expression via inhibiting YAP.

CONCLUSION

The therapeutic benefit of TKF against liver fibrosis results from inhibition of YAP and Notch3-Hes1 pathways, indicating that TKF may be a novel therapeutic candidate for liver fibrosis.

LncRNA Airn maintains LSEC differentiation to alleviate liver fibrosis via the KLF2-eNOS-sGC pathway

BACKGROUND

Long noncoding RNAs (lncRNAs) have emerged as important regulators in a variety of human diseases. The dysregulation of liver sinusoidal endothelial cell (LSEC) phenotype is a critical early event in the fibrotic process. However, the biological function of lncRNAs in LSEC still remains unclear.

METHODS

The expression level of lncRNA Airn was evaluated in both human fibrotic livers and serums, as well as mouse fibrotic livers. Gain- and loss-of-function experiments were performed to detect the effect of Airn on LSEC differentiation and hepatic stellate cell (HSC) activation in liver fibrosis. Furthermore, RIP, RNA pull-down-immunoblotting, and ChIP experiments were performed to explore the underlying mechanisms of Airn.

RESULTS

We have identified Airn was significantly upregulated in liver tissues and LSEC of carbon tetrachloride (CCl₄)-induced liver fibrosis mouse model. Moreover, the expression of AIRN in fibrotic human liver tissues and serums was remarkably increased compared with healthy controls. In vivo studies showed that Airn deficiency aggravated CCl₄- and bile duct ligation (BDL)-induced liver fibrosis, while Airn over-expression by AAV8 alleviated CCl₄-induced liver fibrosis. Furthermore, we revealed that Airn maintained LSEC differentiation in vivo and in vitro. Additionally, Airn inhibited HSC activation indirectly by regulating LSEC differentiation and promoted hepatocyte (HC) proliferation by increasing paracrine secretion of Wnt2a and HGF from LSEC. Mechanistically, Airn interacted with EZH2 to maintain LSEC differentiation through KLF2-eNOS-sGC pathway, thereby maintaining HSC quiescence and promoting HC proliferation.

CONCLUSIONS

Our work identified that Airn is beneficial to liver fibrosis by maintaining LSEC differentiation and might be a serum biomarker for liver fibrogenesis.

Quantitative Assessment of Liver Impairment in Chronic Viral Hepatitis with [99mTc]Tc-Mebrofenin: A Noninvasive Attempt to Stage Viral Hepatitis-Associated Liver Fibrosis

Background and objectives—Chronic viral hepatitis B and C infections are one of the leading causes of chronic liver impairment, resulting in liver fibrosis and liver cirrhosis. An early diagnosis with accurate liver fibrosis staging leads to a proper diagnosis, thus tailoring correct treatment. Both invasive and noninvasive techniques are used in the diagnosis and staging of chronic liver impairment. Those techniques include liver biopsy, multiple serological markers (as either single tests or combined panels), and imaging examinations, such as ultrasound or magnetic resonance elastography. Nuclear medicine probes may also be employed in staging liver fibrosis, although the literature scarcely reports this. The purpose of our study was to investigate whether a dynamic liver scintigraphy with [^99mTc]Tc-mebrofenin has any value in staging or grading chronic liver damage. Materials and Methods—We prospectively enrolled patients with chronic viral hepatitis B and C infection referred for liver biopsy. All patient underwent dynamic liver scintigraphy with 99mTc-mebrofenin prior to liver biopsy. Dynamic liver scintigraphy was performed immediately after intravenous tracer injection for 30 min scanning time. Multiple scintigraphy parameters were calculated (whole liver lobe and focal area time to peak (TTP), 30 min to peak ratio (30/peak), whole lobe and focal area slope index in 350 s (slope_350). Liver biopsy took place shortly after imaging. Results—We found that many dynamic scintigraphic parameters are positively or negatively associated with different stages of liver fibrosis. The main parameters that showed most value are the ratio between 30 min and the peak of the dynamic curve (30/peak_dex (ratio)), and liver clearance corrected for body surface area and liver area (LCL_m²_dm² (%/min/m²/dm²)). Conclusions—Our present study proves that conducting dynamic liver scintigraphies with [^99mTc]Tc-mebrofenin has potential value in staging liver fibrosis. The benefits of this method, including whole liver imaging and direct imaging of the liver function, provide an advantage over presently used quantitative imaging modalities.

Compound Biejia-Ruangan tablet as an adjunctive therapy to entecavir for chronic hepatitis B complicated with hepatic fibrosis: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The compound Biejia-Ruangan tablet (CBRT), as an adjunctive therapy to entecavir, is a potential treatment for hepatic fibrosis (HF) in patients with chronic hepatitis B (HBV). However, the present study yielded inconsistent results. In this systematic review and meta-analysis, we comprehensively investigated the efficacy and safety of CBRT as an adjunctive modality to entecavir for the treatment of HBV infection complicated with HF.

METHODS

We searched the Cochrane Library, PubMed, Embase, CNKI, VIP, CBM, and Wangfang databases through April 1, 2022, for randomized controlled trials (RCTs) assessing the effect and safety of CBRT as an adjunctive modality to entecavir for HBV complicated with HF. The primary outcomes were biochemical parameters of serum hyaluronic acid, laminin (LN), pretype-III collagen (PC-III), and type IV collagen (IV-C). The secondary outcomes were liver function indices of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBiL) levels, total effect rate, and occurrence rate of adverse events. Two researchers independently conducted study selection, data extraction, and quality assessment. Statistical analysis was performed using the RevMan 5.3 software.

RESULTS

Eight RCTs involving 747 patients were included. Compared with entecavir monotherapy, CBRT as an adjunctive therapy to entecavir exerted more encouraging effect in serum levels of hyaluronic acid (mean difference [MD] = -28.15; 95% confidence interval [CI]: -43.82 to -12.47; P < .001), LN (MD = -29.46; 95% CI: -50.69 to -8.23; P < .001), PC-III (MD = -11.83; 95% CI: -19.43 to -4.23; P < .001), and IV-C (MD = -19.62; 95% CI: -29.76 to -9.49; P < .001); levels of serum ALT (MD = -16.83; 95% CI: -26.30 to -7.36; P < .001), AST (MD = -20.52; 95% CI: -33.11 to -7.93; P < .001), and TBiL (MD = -7.54; 95% CI: -11.58 to -3.49; P < .001); and total effect rate (odds ratio = 3.53; 95% CI: 1.71-7.29; P < .001). Meta-analysis results also showed that CBRT as an adjunctive therapy to entecavir had a lower occurrence rate of adverse events (odds ratio = 0.54; 95% CI: 0.22-1.34; P < .001) than entecavir alone.

CONCLUSION

The results of this study showed that CBRT as an adjunctive modality to entecavir may benefit HBV patients complicated with HF. High-quality RCTs are needed to confirm the current findings in the future.

Loss of FOCAD, operating via the SKI messenger RNA surveillance pathway, causes a pediatric syndrome with liver cirrhosis

Cirrhosis is usually a late-onset and life-threatening disease characterized by fibrotic scarring and inflammation that disrupts liver architecture and function. While it is typically the result of alcoholism or hepatitis viral infection in adults, its etiology in infants is much less understood. In this study, we report 14 children from ten unrelated families presenting with a syndromic form of pediatric liver cirrhosis. By genome/exome sequencing, we found recessive variants in FOCAD segregating with the disease. Zebrafish lacking focad phenocopied the human disease, revealing a signature of altered messenger RNA (mRNA) degradation processes in the liver. Using patient's primary cells and CRISPR-Cas9-mediated inactivation in human hepatic cell lines, we found that FOCAD deficiency compromises the SKI mRNA surveillance pathway by reducing the levels of the RNA helicase SKIC2 and its cofactor SKIC3. FOCAD knockout hepatocytes exhibited lowered albumin expression and signs of persistent injury accompanied by CCL2 overproduction. Our results reveal the importance of FOCAD in maintaining liver homeostasis and disclose a possible therapeutic intervention point via inhibition of the CCL2/CCR2 signaling axis.

Liver fibrosis quantification

Liver fibrosis (LF) is the wound healing response to chronic liver injury. LF is the endpoint of chronic liver disease (CLD) regardless of etiology and the single most important determinant of long-term liver-related clinical outcomes. Quantification of LF is important for staging, to evaluate response to treatment and to predict outcomes. LF is traditionally staged by liver biopsy. However, liver biopsy is invasive and suffers from sampling errors when biopsy size is inadequate; therefore, non-invasive tests (NITs) have found important roles in clinical care. NITs include simple laboratory-based serum tests, panels of serum tests, and imaging biomarkers. NITs are validated against the liver biopsy and will be used in the future for evaluation of nearly all CLDs with invasive liver biopsy reserved for some cases. Both serum tests and some imaging biomarkers such as elastography are currently used clinically as surrogate markers for LF. Several other imaging biomarkers are still considered research and awaiting clinical application in the future. As the evaluation of imaging biomarkers will likely become the norm in the future, understanding pathogenesis of LF is important. Knowledge of properties measured by imaging biomarkers and its correlation with LF is important to understand the application of NITs by abdominal radiologists. In this review, we present a brief overview of pathogenesis of LF, spatiotemporal evolution of LF in different CLD, and severity assessment with liver biopsy. This will be followed by a brief discussion on properties measured by imaging biomarkers and their relationship to the LF.

Effect of miR-183-5p on Cholestatic Liver Fibrosis by Regulating Fork Head Box Protein O1 Expression

Liver fibrosis is a common pathological feature of end-stage liver disease and has no effective treatment. MicroRNAs (miRNAs) have been found to modulate gene expression in liver disease. But the potential role of miRNA in hepatic fibrosis is still unclear. The objective of this research is to study the potential mechanism and biological function of miR-183-5p in liver fibrosis. In this study, we used high-throughput sequencing to find that miR-183-5p is upregulated in human fibrotic liver tissues. In addition, miR-183-5p was upregulated both in rat liver fibrosis tissue induced by bile-duct ligation (BDL) and activated LX-2 cells (human hepatic stellate cell line) according to the result of quantitative real-time PCR (RT-qPCR). Moreover, the inhibition of miR-183-5p alleviated liver fibrosis, decreased the fibrotic biomarker levels in vitro and in vivo, and led toLX-2 cell proliferation inhibition and, apoptosis induction. The result of dual-luciferase assay revealed that miR-183-5p suppressed fork head box protein O1 (FOXO1) expression by binding to its 3'UTR directly. Next, we used lentivirus to overexpress FOXO1 in LX-2 cells, and we found that overexpression of FOXO1 reversed the promotion of miR-183-5p on liver fibrosis, reducing the fibrotic biomarker levels inLX-2 cells, inhibitingLX-2 cell proliferation, and promoting apoptosis. Furthermore, overexpression of FOXO1 prevented the activation of the transforming growth factor (TGF)-β signaling pathway in TGF-β1-induced LX-2 cells according to the result of western blotting. In conclusion, the findings showed thatmiR-183-5p might act as a key regulator of liver fibrosis, and miR-183-5p could promote cholestatic liver fibrosis by inhibiting FOXO1 expression through the TGF-β signaling pathway. Thus, inhibition of miR-183-5pmay be a new way to prevent and improve liver fibrosis.

Pantoprazole ameliorates liver fibrosis and suppresses hepatic stellate cell activation in bile duct ligation rats by promoting YAP degradation

Liver fibrosis is one of the most severe pathologic consequences of chronic liver diseases, and effective therapeutic strategies are urgently needed. Proton pump inhibitors (PPIs) are H⁺/K⁺-ATPase inhibitors and currently used to treat acid-related diseases such as gastric ulcers, which have shown other therapeutic effects in addition to inhibiting acid secretion. However, few studies have focused on PPIs from the perspective of inhibiting hepatic fibrosis. In the present study, we investigated the effects of pantoprazole (PPZ), a PPI, against liver fibrosis in a bile duct ligation (BDL) rat model, human hepatic stellate cell (HSC) line LX-2 and mouse primary HSCs (pHSCs), and explored the potential mechanisms underlying the effects of PPZ in vitro and in vivo. In BDL rats, administration of PPZ (150 mg· kg^-1· d^-1, i.p. for 14 d) significantly attenuated liver histopathological injury, collagen accumulation, and inflammatory responses, and suppressed fibrogenesis-associated gene expression including Col1a1, Acta2, Tgfβ1, and Mmp-2. In LX-2 cells and mouse pHSCs, PPZ (100-300 μM) dose-dependently suppressed the levels of fibrogenic markers. We conducted transcriptome analysis and subsequent validation in PPZ-treated LX-2 cells, and revealed that PPZ inhibited the expression of Yes-associated protein (YAP) and its downstream targets such as CTGF, ID1, survivin, CYR61, and GLI2. Using YAP overexpression and silencing, we demonstrated that PPZ downregulated hepatic fibrogenic gene expression via YAP. Furthermore, we showed that PPZ promoted the proteasome-dependent degradation and ubiquitination of YAP, thus inhibiting HSC activation. Additionally, we showed that PPZ destabilized YAP by disrupting the interaction between a deubiquitinating enzyme OTUB2 and YAP, and subsequently blocked the progression of hepatic fibrosis.

Wild Bitter Melon Extract Regulates LPS-Induced Hepatic Stellate Cell Activation, Inflammation, Endoplasmic Reticulum Stress, and Ferroptosis

The activation of hepatic stellate cells (HSCs) is a key component of liver fibrosis. Two antifibrosis pathways have been identified, the reversion to quiescent-type HSCs and the clearance of HSCs through apoptosis. Lipopolysaccharide- (LPS-) induced HSCs activation and proliferation have been associated with the development of liver fibrosis. We determined the pharmacological effects of wild bitter melon (WM) on HSC activation following LPS treatment and investigated whether WM treatment affected cell death pathways under LPS-treated conditions, including ferroptosis. WM treatment caused cell death, both with and without LPS treatment. WM treatment caused reactive oxygen species (ROS) accumulation without LPS treatment and reversed the decrease in lipid ROS production in HSCs after LPS treatment. We examined the effects of WM treatment on fibrosis, endoplasmic reticulum (ER) stress, inflammation, and ferroptosis in LPS-activated HSCs. The western blotting analysis revealed that the WM treatment of LPS-activated HSCs induced the downregulation of the connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), integrin-β1, phospho-JNK (p-JNK), glutathione peroxidase 4 (GPX4), and cystine/glutamate transporter (SLC7A11) and the upregulation of CCAAT enhancer-binding protein homologous protein (CHOP). These results support WM as an antifibrotic agent that may represent a potential therapeutic solution for the management of liver fibrosis.

Exploring Interactions between Primary Hepatocytes and Non-Parenchymal Cells on Physiological and Pathological Liver Stiffness

Simple Summary

Chronic liver disease is characterized by progressive hepatic fibrosis leading to the formation of cirrhosis irrespective of the etiology with no effective treatment currently available. Liver stiffness (LS) is currently the best clinical predictor of this fibrosis progression irrespective of the cause of the disease. However, it is not well understood how does LS regulate the critical hepatocytes–non parenchymal cell interactions. We here present, to the best of our knowledge, the first analyses of the impact of physiological and pathological stiffness on hepatocytes–non parenchymal cell interaction. Our findings indicate the role of stiffness in regulating the hepatocytes interactions with NPCs necessary for maintenance of hepatocytes function.

Abstract

Chronic liver disease is characterized by progressive hepatic fibrosis leading to the formation of cirrhosis irrespective of the etiology with no effective treatment currently available. Liver stiffness (LS) is currently the best clinical predictor of this fibrosis progression irrespective of the etiology. LS and hepatocytes-nonparenchymal cells (NPC) interactions are two variables known to be important in regulating hepatic function during liver fibrosis, but little is known about the interplay of these cues. Here, we use polydimethyl siloxane (PDMS) based substrates with tunable mechanical properties to study how cell–cell interaction and stiffness regulates hepatocytes function. Specifically, primary rat hepatocytes were cocultured with NIH-3T3 fibroblasts on soft (2 kPa) and stiff substrates that recreates physiologic (2 kPa) and cirrhotic liver stiffness (55 kPa). Urea synthesis by primary hepatocytes depended on the presence of fibroblast and was independent of the substrate stiffness. However, albumin synthesis and Cytochrome P450 enzyme activity increased in hepatocytes on soft substrates and when in coculture with a fibroblast. Western blot analysis of hepatic markers, E-cadherin, confirmed that hepatocytes on soft substrates in coculture promoted better maintenance of the hepatic phenotype. These findings indicate the role of stiffness in regulating the hepatocytes interactions with NPCs necessary for maintenance of hepatocytes function.

Pathological Study of Facial Eczema (Pithomycotoxicosis) in Sheep

Simple Summary

Facial eczema (FE) is a secondary photosensitization disease of farm ruminants caused by the sporidesmin A, present in the spores of the saprophytic fungus Pithomyces chartarum. This study communicates an outbreak of ovine FE in Asturias (Spain) and characterizes the local immune response that may contribute to liver damage promoting cholestasis and progression towards fibrosis and cirrhosis. Animals showed clinical signs of photosensitivity and lower gain of weight, loss of wool and crusting in the head for at least 6 months after the FE outbreak. Some sheep presented acute lesions characterized by subcutaneous edema in the head, cholestasis and nephrosis with macrophages and neutrophils present in areas of canalicular cholestasis. In chronic cases, alopecia and crusting, hepatic atrophy with regenerative nodules, fibrosis and gallstones were seen. The surviving parenchyma persisted with a jigsaw pattern characteristic of biliary cirrhosis. Concentric and eccentric myointimal proliferation was found in arteries near damaged bile ducts, where macrophages and lymphocytes were also observed.

Abstract

Facial eczema (FE) is a secondary photosensitization disease of farm ruminants caused by the sporidesmin A, produced in the spores of the saprophytic fungus Pithomyces chartarum. This study communicates an outbreak of ovine FE in Asturias (Spain) and characterizes the serum biochemical pattern and the immune response that may contribute to liver damage, favoring cholestasis and the progression to fibrosis and cirrhosis. Animals showed clinical signs of photosensitivity, with decrease of daily weight gain and loss of wool and crusting for at least 6 months after the FE outbreak. Serum activity of γ-glutamyltransferase and alkaline phosphatase were significantly increased in sheep with skin lesions. In the acute phase, edematous skin lesions in the head, hepatocytic and canalicular cholestasis in centrilobular regions, presence of neutrophils in small clumps surrounding deposits of bile pigment, ductular proliferation, as well as cholemic nephrosis, were observed. Macrophages, stained positively for MAC387, were found in areas of canalicular cholestasis. In the chronic phase, areas of alopecia and crusting were seen in the head, and the liver was atrophic with large regeneration nodules and gallstones. Fibrosis around dilated bile ducts, “typical” and “atypical” ductular reaction and an inflammatory infiltrate composed of lymphocytes and pigmented macrophages, with iron deposits and lipofuscin, were found. The surviving parenchyma persisted with a jigsaw pattern characteristic of biliary cirrhosis. Concentric and eccentric myointimal proliferation was found in arteries near damaged bile ducts. In cirrhotic livers, stellated cells, ductular reaction, ectatic bile ducts and presence of M2 macrophages and lymphocytes, were observed in areas of bile ductular reaction.

Neoagarooligosaccharide Protects against Hepatic Fibrosis via Inhibition of TGF-β/Smad Signaling Pathway

Hepatic fibrosis occurs when liver tissue becomes scarred from repetitive liver injury and inflammatory responses; it can progress to cirrhosis and eventually to hepatocellular carcinoma. Previously, we reported that neoagarooligosaccharides (NAOs), produced by the hydrolysis of agar by β-agarases, have hepatoprotective effects against acetaminophen overdose-induced acute liver injury. However, the effect of NAOs on chronic liver injury, including hepatic fibrosis, has not yet been elucidated. Therefore, we examined whether NAOs protect against fibrogenesis in vitro and in vivo. NAOs ameliorated PAI-1, α-SMA, CTGF and fibronectin protein expression and decreased mRNA levels of fibrogenic genes in TGF-β-treated LX-2 cells. Furthermore, downstream of TGF-β, the Smad signaling pathway was inhibited by NAOs in LX-2 cells. Treatment with NAOs diminished the severity of hepatic injury, as evidenced by reduction in serum alanine aminotransferase and aspartate aminotransferase levels, in carbon tetrachloride (CCl4)-induced liver fibrosis mouse models. Moreover, NAOs markedly blocked histopathological changes and collagen accumulation, as shown by H&E and Sirius red staining, respectively. Finally, NAOs antagonized the CCl4-induced upregulation of the protein and mRNA levels of fibrogenic genes in the liver. In conclusion, our findings suggest that NAOs may be a promising candidate for the prevention and treatment of chronic liver injury via inhibition of the TGF-β/Smad signaling pathway.

Complexation with Random Methyl-β-Cyclodextrin and (2-Hidroxypropyl)-β-Cyclodextrin Enhances In Vivo Anti-Fibrotic and Anti-Inflammatory Effects of Chrysin via the Inhibition of NF-κB and TGF-β1/Smad Signaling Pathways and Modulation of Hepatic Pro/Anti-Fibrotic miRNA

Chrysin (CHR) is a natural flavonoid with a wide range of pharmacological activities, including hepatoprotection, but poor water solubility. By including water-soluble hydroxypropyl (HPBCD) and randomly methylated (RAMEB) β-cyclodextrin, we aimed to increase its biodisponibility and the effectiveness of the antifibrotic effects of chrysin at oral administration. Liver fibrosis in mice was induced in 7 weeks by CCl₄ i.p. administration, and afterwards treated with 50 mg/kg of CHR-HPBCD, CHR-RAMEB, and free chrysin. CCl₄ administration increased hepatic inflammation (which was augmented by the upregulation of nuclear factor kappa-light-chain enhancer of activated B cells (NF-kB), tumor necrosis factor (TNF)-α, and interleukin 6 (IL-6) and induced fibrosis, as determined using histopathology and electron microscopy. These results were also confirmed by the upregulation of Collagen I (Col I) and matrix metalloproteinase (MMP) expression, which led to extracellular fibrotic matrix proliferation. Moreover, the immunopositivity of alpha-smooth muscle actin (a-SMA) in the CCl₄ group was evidence of hepatic stellate cell (HSC) activation. The main profibrotic pathway was activated, as confirmed by an increase in the transforming growth factor- β1 (TGF-β1) and Smad 2/3 expression, while Smad 7 expression was decreased. Treatment with CHR–HPBCD and CHR–RAMEB considerably reduced liver injury, attenuated inflammation, and decreased extracellular liver collagen deposits. CHR–RAMEB was determined to be the most active antifibrotic complex. We conclude that both nanocomplexes exert anti-inflammatory effects and antifibrotic effects in a considerably stronger manner than for free chrysin administration.

Oral Bisphenol A Worsens Liver Immune-Metabolic and Mitochondrial Dysfunction Induced by High-Fat Diet in Adult Mice: Cross-Talk between Oxidative Stress and Inflammasome Pathway

Lines of evidence have shown the embryogenic and transgenerational impact of bisphenol A (BPA), an endocrine-disrupting chemical, on immune-metabolic alterations, inflammation, and oxidative stress, while BPA toxic effects in adult obese mice are still overlooked. Here, we evaluate BPA’s worsening effect on several hepatic maladaptive processes associated to high-fat diet (HFD)-induced obesity in mice. After 12 weeks HFD feeding, C57Bl/6J male mice were exposed daily to BPA (50 μg/kg per os) along with HFD for 3 weeks. Glucose tolerance and lipid metabolism were examined in serum and/or liver. Hepatic oxidative damage (reactive oxygen species, malondialdehyde, antioxidant enzymes), and mitochondrial respiratory capacity were evaluated. Moreover, liver damage progression and inflammatory/immune response were determined by histological and molecular analysis. BPA amplified HFD-induced alteration of key factors involved in glucose and lipid metabolism, liver triglycerides accumulation, and worsened mitochondrial dysfunction by increasing oxidative stress and reducing antioxidant defense. The exacerbation by BPA of hepatic immune-metabolic dysfunction induced by HFD was shown by increased toll-like receptor-4 and its downstream pathways (i.e., NF-kB and NLRP3 inflammasome) amplifying inflammatory cytokine transcription and promoting fibrosis progression. This study evidences that BPA exposure represents an additional risk factor for the progression of fatty liver diseases strictly related to the cross-talk between oxidative stress and immune-metabolic impairment due to obesity.

Fuzheng Huayu Recipe Prevented and Treated CCl4-Induced Mice Liver Fibrosis through Regulating Polarization and Chemotaxis of Intrahepatic Macrophages via CCL2 and CX3CL1

Background

Fuzheng Huayu recipe (FZHY) is an original Chinese patent medicine which was developed and marketed by our institute. It could markedly improve liver tissue inflammation and ameliorate hepatic fibrosis in the clinical study. The intrahepatic macrophages recruitment and polarization play an important role in the progress of liver inflammation and fibrosis. Whether FZHY exerted its antiliver fibrosis effects through regulating intrahepatic macrophages phenotypic ratios is still unknown. This study aims to explore the antifibrosis mechanism of FZHY on regulating the recruitment and polarization of intrahepatic macrophages.

Methods

C57/B6 mice were used for the establishment of the CCl4-induced mice liver fibrosis model. Liver inflammation and fibrosis were evaluated by HE and Sirius red staining, hydroxyproline assays, and biochemical tests. The levels of chemokines and inflammatory cytokines in liver tissue were measured by RNA-Seq transcriptome analysis, western blot assay, RT-qPCR, and immunofluorescence assay. The macrophages recruitment and phenotypic polarization were observed by flow cytometry.

Results

FZHY significantly improved liver inflammation and reduced liver fibrosis degree. TNF signaling pathway, involved in macrophages recruitment and phenotypic polarization, was discovered by RNA-Seq transcriptome analysis. In TNF signaling pathway, CCL2 expression was significantly decreased and CX3CL1 expression was significantly upregulated by FZHY in liver tissue and primary intrahepatic macrophages. The ratio of proinflammatory hepatic resident macrophage-Kupffer cells (F4/80⁺CD11b⁻CD86⁺) was downregulated by FZHY, while the proportion of anti-inflammatory Kupffer cells (F4/80⁺CD11b⁻CD206⁺) was upregulated. Meanwhile, the ratio of proinflammatory Ly6C^high macrophages (F4/80⁺CD11b⁺Ly6C^high) which were recruited from blood circulation by CCL2 was reduced by FZHY, while the ratio of restorative Ly6C^low macrophages (F4/80⁺CD11b⁺Ly6C^low) which were recruited from blood circulation or induced from Ly6C^high macrophages polarization by CX3CL1 was significantly increased.

Conclusions

FZHY could regulate the recruitment and polarization of intrahepatic macrophages via CCL2 and CX3CL1, so as to play its anti-inflammation and antifibrosis pharmacological effects in the liver.

Hawthorn Herbal Preparation from Crataegus oxyacantha Attenuates In Vivo Carbon Tetrachloride -Induced Hepatic Fibrosis via Modulating Oxidative Stress and Inflammation

Hawthorn (HAW) is a herbal preparation extracted from Crataegus oxyacantha. HAW has cardioprotective, antioxidants, anti-inflammatory, and anti-hypotensive effects. HAW’s effect on hepatic fibrosis remains, however, unknown. This study evaluated the impact of HAW on carbon tetrachloride (CCl4)-induced hepatic fibrosis in rats and elucidated its mechanisms. HAW reduced liver index and the serum liver enzyme markers and reduced liver damage, and fibrosis as confirmed by histopathological scoring of hematoxylin-eosin staining. Collagen deposition was reduced in HAW group compared to CCl4 group as confirmed by Masson staining, hydroxyproline content, and both mRNA and protein levels of alpha-smooth muscle actin, collagen 1 and 3. HAW also down regulated the gene expressions of inflammatory markers including interleukin-IL-1β, tumor necrosis factor-α, transforming growth factor-β 1, nuclear factor kappa-B, and cyclooxygenase-2 and decreased the myeloperoxidase activity. The effects of HAW was also associated with decreased levels of hepatic oxidative stress markers (malondialdehyde and P.Carbonyl) and with increased activity of superoxide dismutase. Those effects are possibly mediated by blocking the pro-oxidant machinery and down regulating the inflammatory and profibrotic responses. Finally, chlorogenic acid, epicatechin, rutin, vitexin quercetin, and iso quercetin were identified as the major species of polyphenols of the HAW herbal preparation used here. Therefore, HAW’s potent protecting effects against liver fibrosis predicts a significant beneficial application.

High-fat diet induces fibrosis in mice lacking CYP2A5 and PPARα: a new model for steatohepatitis-associated fibrosis

Obesity is linked to nonalcoholic steatohepatitis. Peroxisome proliferator-activated receptor-α (PPARα) regulates lipid metabolism. Cytochrome P-450 2A5 (CYP2A5) is a potential antioxidant and CYP2A5 induction by ethanol is CYP2E1 dependent. High-fat diet (HFD)-induced obesity and steatosis are more severe in CYP2A5 knockout (cyp2a5^-/-) mice than in wild-type mice although PPARα is elevated in cyp2a5^-/- mice. To examine why the upregulated PPARα failed to prevent the enhanced steatosis in cyp2a5^-/- mice, we abrogate the upregulated PPARα in cyp2a5^-/- mice by cross-breeding cyp2a5^-/- mice with PPARα knockout (pparα^-/-) mice to create pparα^-/-/cyp2a5^-/- mice. The pparα^-/-/cyp2a5^-/- mice, pparα^-/- mice, and cyp2a5^-/- mice were fed HFD to induce steatosis. After HFD feeding, more severe steatosis was developed in pparα^-/-/cyp2a5^-/- mice than in pparα^-/- mice and cyp2a5^-/- mice. The pparα^-/-/cyp2a5^-/- mice and pparα^-/- mice exhibited comparable and impaired lipid metabolism. Elevated serum alanine transaminase and liver interleukin-1β, liver inflammatory cell infiltration, and foci of hepatocellular ballooning were observed in pparα^-/-/cyp2a5^-/- mice but not in pparα^-/- mice and cyp2a5^-/- mice. In pparα^-/-/cyp2a5^-/- mice, although redox-sensitive transcription factor nuclear factor erythroid 2-related factor 2 and its target antioxidant genes were upregulated as a compensation, thioredoxin was suppressed, and phosphorylation of JNK and formation of nitrotyrosine adduct were increased. Liver glutathione was decreased, and lipid peroxidation was increased. Interestingly, inflammation and fibrosis were all observed within the clusters of lipid droplets, and these lipid droplet clusters were all located inside the area with CYP2E1-positive staining. These results suggest that HFD-induced fibrosis in pparα^-/-/cyp2a5^-/- mice is associated with steatosis, and CYP2A5 interacts with PPARα to participate in regulating steatohepatitis-associated fibrosis.

Friend or Foe: Lipid Droplets as Organelles for Protein and Lipid Storage in Cellular Stress Response, Aging and Disease

Lipid droplets (LDs) were considered as a mere lipid storage organelle for a long time. Recent evidence suggests that LDs are in fact distinct and dynamic organelles with a specialized proteome and functions in many cellular roles. As such, LDs contribute to cellular signaling, protein and lipid homeostasis, metabolic diseases and inflammation. In line with the multitude of functions, LDs interact with many cellular organelles including mitochondria, peroxisomes, lysosomes, the endoplasmic reticulum and the nucleus. LDs are highly mobile and dynamic organelles and impaired motility disrupts the interaction with other organelles. The reduction of interorganelle contacts results in a multitude of pathophysiologies and frequently in neurodegenerative diseases. Contacts not only supply lipids for β-oxidation in mitochondria and peroxisomes, but also may include the transfer of toxic lipids as well as misfolded and harmful proteins to LDs. Furthermore, LDs assist in the removal of protein aggregates when severe proteotoxic stress overwhelms the proteasomal system. During imbalance of cellular lipid homeostasis, LDs also support cellular detoxification. Fine-tuning of LD function is of crucial importance and many diseases are associated with dysfunctional LDs. We summarize the current understanding of LDs and their interactions with organelles, providing a storage site for harmful proteins and lipids during cellular stress, aging inflammation and various disease states.

Chrysophanol attenuates hepatitis B virus X protein-induced hepatic stellate cell fibrosis by regulating endoplasmic reticulum stress and ferroptosis

Hepatitis B virus X protein (HBx) and hepatic stellate cells (HSCs) are critical for liver fibrosis development. Anti-fibrosis occurs via reversion to quiescent-type HSCs or clearance of HSCs via apoptosis or ferroptosis. We aimed to elucidate the role of chrysophanol in rat HSC-T6 cells expressing HBx and investigate whether chrysophanol (isolated from Rheum palmatum rhizomes) influences cell death via ferroptosis in vitro. Analysis of lipid reactive oxygen species (ROS), Bip, CHOP, p-IRE1α, GPX4, SLC7A11, α-SMA, and CTGF showed that chrysophanol attenuated HBx-repressed cell death. Chrysophanol can impair HBx-induced activation of HSCs via endoplasmic reticulum stress (ER stress) and ferroptosis-dependent and GPX4-independent pathways.

The roles of galectins in hepatic diseases

Hepatic diseases include all diseases that occur in the liver, including hepatitis, cirrhosis, hepatocellular carcinoma, etc. Hepatic diseases worldwide are characterized by high incidences of digestive system diseases, which present with subtle symptoms, are difficult to treat and have high mortality. Galectins are β-galactoside-binding proteins that have been found to be aberrantly expressed during hepatic disease progression. An increasing number of studies have shown that abnormal expression of galectins is extensively involved in hepatic diseases, such as hepatocellular carcinoma (HCC), liver cirrhosis, hepatitis and liver fibrosis. Galectins function as intracellular and extracellular hepatic disease regulators mainly through the binding of their carbohydrate recognition domain to glycoconjugates expressed in hepatocytes. In this review, we summarize current research on the various roles of galectins in cirrhosis, hepatitis, liver fibrosis and HCC, which may provide a preliminary theoretical basis for the exploration of new targets for the treatment of hepatic diseases.

GNS561 acts as a potent anti-fibrotic and pro-fibrolytic agent in liver fibrosis through TGF-β1 inhibition

Background:

Hepatic fibrosis is the result of chronic liver injury that can progress to cirrhosis and lead to liver failure. Nevertheless, there are no anti-fibrotic drugs licensed for human use. Here, we investigated the anti-fibrotic activity of GNS561, a new lysosomotropic molecule with high liver tropism.

Methods:

The anti-fibrotic effect of GNS561 was determined in vitro using LX-2 hepatic stellate cells (HSCs) and primary human HSCs by studying cell viability, activity of caspases 3/7, autophagic flux, cathepsin maturation and activity, HSC activation and transforming growth factor-β1 (TGF-β1) maturation and signaling. The contribution of GNS561 lysosomotropism to its anti-fibrotic activity was assessed by increasing lysosomal pH. The potency of GNS561 on fibrosis was evaluated in vivo in a rat model of diethylnitrosamine-induced liver fibrosis.

Results:

GNS561 significantly decreased cell viability and promoted apoptosis. Disrupting the lysosomal pH gradient impaired its pharmacological effects, suggesting that GNS561 lysosomotropism mediated cell death. GNS561 impaired cathepsin activity, leading to defective TGF-β1 maturation and autophagic processes. Moreover, GNS561 decreased HSC activation and extracellular matrix deposition by downregulating TGF-β1/Smad and mitogen-activated proteine kinase signaling and inducing fibrolysis. Finally, oral administration of GNS561 (15 mg/kg per day) was well tolerated and attenuated diethylnitrosamine-induced liver fibrosis in this rat model (decrease of collagen deposition and of pro-fibrotic markers and increase of fibrolysis).

Conclusion:

GNS561 is a new potent lysosomotropic compound that could represent a valid medicinal option for hepatic fibrosis treatment through both its anti-fibrotic and its pro-fibrolytic effects. In addition, this study provides a rationale for targeting lysosomes as a promising therapeutic strategy in liver fibrosis.

Platycodin D alleviates liver fibrosis and activation of hepatic stellate cells by regulating JNK/c-JUN signal pathway

Liver fibrosis is involved in the progression of most chronic liver diseases. Even though we have made a huge progress in order to understand the pathogenesis of liver fibrosis, however, there is still a lack of productive treatments. Being a traditional Chinese medicine, Platycodin D (PD), an oleanane kind of triterpenoid saponin has been put to extensive use for treating different kinds of illnesses that include not just anti-nociceptive, but also antiviral, anti-inflammatory, and anti-cancer for thousands of years. Nonetheless, there has been no clarification made for its effects on the progression of liver fibrosis. In this manner, we carried out in vitro studies for the purpose of investigating the anti-fibrosis impact of PD. Activation of hepatic stellate cells was evaluated by means of the detection of the proliferation of HSCs and the expression of specific proteins. We discovered the fact that PD had the potential of activating HSCs. Thereafter, we detected the apoptosis and autophagy of the HSCs; as the results suggested, PD induced apoptosis and autophagy of the HSCs. It augmented the expression level of apoptotic proteins that included Bax, Cytochrome C (cyto-c), cleaved caspase3 and cleaved caspase9, in addition to the autophagy relevant proteins, for instance, LC3II, beclin1, Atg5 and Atg9. Further research was carried out for the investigation of the underlying molecular mechanism, and discovered that PD promoted the phosphorylation of JNK and c-Jun. Treating the JNK inhibitor P600125 inhibited the effect of PD, confirming the impact of PD on the regulation of JNK/c-Jun pathway. Thus, we speculated that PD alleviates liver fibrosis and activation of hepatic stellate via promoting phosphorylation of JNK and c-Jun and further altering the autophagy along with apoptosis of HSCs.

Effect of hepato-toxins in the acceleration of hepatic fibrosis in hepatitis B mice

Chronic liver diseases such as hepatitis B viral (HBV) infection and liver fibrosis have been a major health problem worldwide. However, less research has been conducted owing to the lack of animal models. The key purpose of this study was to determine the effects of different hepatotoxins in HBV-affected liver. In this study, we successfully generated a combined liver fibrosis model by administering HBV 1.2 plasmid and thioacetamide/ethanol (TAA/EtOH). To our knowledge, this is the first study in which an increase in the liver fibrosis level is observed by the intraperitoneal administration of TAA and EtOH in drinking water after the hydrodynamic transfection of the HBV 1.2 plasmid in C3H/HeN mice. The HBV+TAA/EtOH group exhibited higher level of hepatic fibrosis than that of the control groups. The hepatic stellate cell activation in the TAA- and EtOH-administered groups was demonstrated by the elevation in the level of fibrotic markers. In addition, high levels of collagen content and histopathological results were also used to confirm the prominent fibrotic levels. We established a novel HBV mice model by hydrodynamic injection-based HBV transfection in C3H/HeN mice. C3H/HeN mice were reported to have a higher HBV persistence level than that of the C57BL/6 mouse model. All the results showed an increased fibrosis level in the HBV mice treated with TAA and EtOH; hence, this model would be useful to understand the effect of hepatotoxins on the high risk of fibrosis after HBV infection. The acceleration of liver fibrosis can occur with prolonged administration as well as the high dosage of hepatotoxins in mice.

Co-administration of silymarin elevates the therapeutic effect of praziquantel through modulation of specific antibody profiles, Th1/Th2/Tregs cytokines and down-regulation of fibrogenesis in mice with Mesocestoides vogae (Cestoda) infection

Silymarin (SIL) represents a natural mixture of polyphenols showing an array of health benefits. The present study, carried out on a model cestode infection induced by Mesocestoides vogae tetrathyridia in the ICR strain of mice, was aimed at investigating the impact of SIL as adjunct therapy on the activity of praziquantel (PZQ) in relation to parasite burden, immunity and liver fibrosis within 20 days post-therapy. In comparison with PZQ alone, co-administration of SIL and PZQ stimulated production of total IgG antibodies to somatic and excretory-secretory antigens of metacestodes and modified the expression patterns of immunogenic molecules in both antigenic preparations. The combined therapy resulted in the elevation of IFN-γ and a decline of TNF-α and TGF-β1 in serum as compared to untreated group; however, SIL attenuated significantly the effect of PZQ on IL-4 and stimulated PZQ-suppressed phagocytosis of peritoneal macrophages. In the liver, SIL boosted the effect of PZQ on gene expression of the same cytokines in a similar way as was found in serum, except for down-regulation of PZQ-stimulated TNF-α. Compared to PZQ therapy, the infiltration of mast cells into liver after SIL co-administration was nearly abolished and correlated with suppressed activities of genes for collagen I, collagen III and α-SMA. In conclusion, co-administration of SIL modified the effects of PZQ therapy on antigenic stimulation of the immune system and modulated Th1/Th2/Tregs cytokines. In liver this was accompanied by reduced fibrosis, which correlated with significantly higher reduction of total numbers of tetrathyridia after combined therapy as compared with PZQ treatment.

Liver regeneration in traditional Chinese medicine: advances and challenges

Liver diseases pose a serious problem for national health care system all over the world. Liver regeneration has profound impacts on the occurrence and development of various liver diseases, and it remains an extensively studied topic. Although current knowledge has suggested two major mechanisms for liver regeneration, including compensatory hyperplasia of hepatocytes and stem or progenitor cell-mediated regeneration, the complexity of this physiopathological process determines that its effective regulation cannot be achieved by single-target or single-component approaches. Alternatively, using traditional Chinese medicine (TCM) to regulate liver regeneration is an important strategy for prevention and treatment of liver disorder and the related diseases. From the perspectives of TCM, liver regeneration can be caused by the disrupted balance between hepatic damage and regenerative capacity, and the "marrow"-based approaches have important therapeutic implications for liver regeneration. These two points have been massively supported by a number of basic studies and clinical observations during recent decades. TCM has the advantages of overall dynamic fine-tuning and early adjustment, and has exhibited enormous therapeutic benefits for various liver diseases. Here, we review the recent advances in the understanding of liver regeneration in TCM system in the hope of facilitating the application of TCM for liver diseases via regulation of liver regeneration.

Down-regulation of microRNA-31 suppresses hepatic fibrosis induced by carbon tetrachloride

MicroRNA-31 (miR-31) is among the most frequently altered microRNAs in human diseases, and altered expression of miR-31 has been detected in a large variety of diseases types. miR-31 could also regulate a variety of cell functions including hepatic fibrosis. Hepatic stellate cells (HSCs) are regarded as the major cell type involved in hepatic fibrosis. Male BALB/c mice (five mice per group aged 6 weeks) received 200 μL of body weight of carbon tetrachloride (10% CCl4) mixed with olive oil intraperitoneally, and the first dose was doubled. To induce hepatic fibrosis, carbon tetrachloride was injected twice a week for 4, 6, 8, and 10 weeks. Control animals were injected with an equal volume of olive oil at the same time intervals. We found that miR-31 expression and fibrosis-related factors in four hepatic fibrosis stages. However, we noted that inhibition of miR-31 was down-regulated fibrosis-related factor expression in F1–F3 stages, but no F4 stage. Thus, we hypothesize that miR-31 may mediate hepatic fibrosis. In this research, we found that inhibition of miR-31 expression significantly inhibited HSC activation. The biological function of miR-31 during HSC activation might be through targeting hypoxia-inducible factor 1-alpha inhibitor (HIF1AN). Inhibition of miR-31 can reduce the transcription factor activity of hypoxia inducible factor 1 (HIF-1) by targeting the biological effects of HIF1AN with the condition of hypoxia. In later hepatic fibrosis could be rescue combining with inhibition of miR-31 and adding heparin-binding EGF-like growth factor (HBEGF).

Synthesis of radioiodinated carnosine for hepatotoxicity imaging induced by carbon tetrachloride and its biological assessment in rats

The imaging of organs is very important in the field of diagnosis especially in case of liver diseases. In the present work, carnosine was successfully labeled with iodine-131 at room temperature in acidic medium using chloramine-T (Ch-T) as moderate oxidizing agent. The parameters affecting labeling of carnosine such as amount of oxidizing agent, amount of substrate, pH value of the reaction mixture, reaction temperature and reaction time, were investigated. The best conditions for formation of 131I-carnosine (131I-CAR) complex were 40 μg of chloramine-T (Ch-T), 75 μg of carnosine, pH 4 and 45 min reaction time at room temperature. The radiochemical yield for 131I-CAR complex was (91 ± 0.11) % at optimum conditions and the labeled complex was stable for 2 h after labeling process. Biodistribution study was achieved using three groups of rats (normal, treated by inactive carnosine and hepatotoxicity rats induced by CCl4). Hepatotoxicity of liver was evaluated using different biochemical markers such as ALT, AST and ALK.P. The 131I-CAR complex showed selective bio-localization in stomach and liver and its selectivity increases in acquired hepatotoxicity. The biological distribution indicates that the suitability of 131I-CAR as a potential hepatotoxicity imaging to detect hepatitis and medical prognosis.

Acoustic radiation force impulse elastography of liver as a screening tool for liver fibrosis in alcoholic liver disease

Context:

Acoustic radiation force impulse (ARFI) elastography is a noninvasive and quantitative technique for diagnosis of liver fibrosis. To the best of our knowledge, there are only two studies reported in literature for evaluation of alcoholic liver disease using ARFI.

Aims:

The aim of this study was to evaluate the diagnostic performance of ARFI elastography for assessing liver fibrosis in alcoholic liver disease and compare it with biochemical indices aspartate transaminase-to-platelet ratio index (APRI) and fibrosis-4 Index (FIB-4) using histopathology as the reference standard.

Settings and Design:

Institutional cross-sectional study.

Methods and Materials:

The patients visiting our hospital over a period of 2 years with a high-risk consumption of alcohol (>40 g/day for men and >20 g/day for women for a cumulative period of more than 5 years) were subjected to ARFI elastography of liver, Liver Function Tests (to calculate APRI and FIB-4 indices), and liver biopsy.

Statistical Analysis Used:

Area under the receiver operating characteristic (AUROC) curve analysis, Kruskal--Wallis test for ANOVA.

Results:

A total of 50 patients of chronic alcoholic liver disease were evaluated with ARFI elastography, which performed better than the biochemical indices in distinguishing cirrhosis of the liver (F = 4) from the severe fibrosis (F ≥ 3) with area under the receiver operating characteristic of 0.97, whereas for significant fibrosis (F ≥ 2) and severe fibrosis (F ≥ 3), it was comparable to the biochemical indices with AUROC of 0.65 and 0.70. In our study, the median shear wave velocity cutoff values were 1.37 m/s, 1.51 m/s, and 1.87 m/s for F ≥ 2, F ≥ 3, and F = 4 fibrosis stages, respectively.

Conclusions:

ARFI elastography is a noninvasive, reliable, and repeatable diagnostic test for grading of liver fibrosis. It performs better than the biochemical indices to differentiate severe fibrosis and cirrhosis of liver.

Integration of VEGF and α-SMA Expression Improves the Prediction Accuracy of Fibrosis in Chronic Hepatitis C Liver Biopsy

INTRODUCTION

The progression of fibrosis in chronic hepatitis C (CHC) is a multifactorial process. The high adverse effects and the cost of standard health care increase the demand to discover new predictors for the progression of fibrosis in CHC patients. Our study aims to establish the relation between the angiogenic marker [vascular endothelial growth factor (VEGF)] and activated hepatic stellate cells (HSCs) represented by the expression of α-smooth muscle actin (α-SMA) and whether these 2 markers can be used as predictors for the progression of fibrosis in patients with CHC.

MATERIALS AND METHODS

Histopathologic and immunohistochemical analyses were used for examining the morphology and the expression of VEGF and α-SMA in 60 CHC biopsies procured from CHC patients. Multivariate analysis was used to correlate the protein expression with staging and grading of liver fibrosis. Cutoff values of α-SMA and VEGF were determined by the receiver operating characteristics curve.

RESULTS

There was a positive correlation between VEGF and HSCs expressing α-SMA (ρ=0.287, P=0.026) and both factors were correlated with the stage of fibrosis (P<0.001). Using the receiver operating characteristics curve, both VEGF (area under the curve=0.71, P<0.006) and α-SMA (area under the curve=0.82, P<0.001) were positive predictors for moderate and severe fibrosis.

CONCLUSIONS

This study demonstrates the relation between VEGF expression and the activated HSCs denoted by the expression of α-SMA in CHC biopsies and together can be used as a predictor for the progression of fibrosis.

Plumbagin ameliorates liver fibrosis via a ROS-mediated NF-кB signaling pathway in vitro and in vivo

AIMS

The purpose of this study was to investigate plumbagin (PL) on liver fibrosis in vitro and in vivo and to explore the underlying mechanisms.

METHODS

Carbon tetrachloride (CCl₄) was used to establish a rat liver fibrosis model, primary hepatic stellate cells (HSCs) were isolated from the rat liver, and fibrosis-related indicators were detected.

RESULTS

The results revealed that PL significantly prevented CCl₄-induced liver fibrosis, as evidenced by the attenuation of histopathological changes, the decrease of MDA and the increase of SOD and GSH-P X . In addition, PL downregulated the mRNA levels of NOX4 and procollagen I; the protein expression levels of NOX4 and p-IκB; and the transcriptional activity of NF-κB in liver fibrosis rats. Moreover, PL significantly decreased ROS expression, protein expression of α-SMA and collagen III, and activation of NF-κB and inhibited the nuclear translocation of NF-κB p65 in IL-1β-stimulated HSCs in vitro.

CONCLUSION

The results of our study indicate that PL can mitigate liver fibrosis in vitro and in vivo, which may be related to the ROS-mediated NF-кB signaling pathway.

The multi-functional roles of menstrual blood-derived stem cells in regenerative medicine

Menstrual blood-derived stem cells (MenSCs) are a novel source of mesenchymal stem cells (MSCs). MenSCs are attracting more and more attention since their discovery in 2007. MenSCs also have no moral dilemma and show some unique features of known adult-derived stem cells, which provide an alternative source for the research and application in regenerative medicine. Currently, people are increasingly interested in their clinical potential due to their high proliferation, remarkable versatility, and periodic acquisition in a non-invasive manner with no other sources of MSCs that are comparable in adult tissue. In this review, the plasticity of pluripotent biological characteristics, immunophenotype and function, differentiative potential, and immunomodulatory properties are assessed. Furthermore, we also summarize their therapeutic effects and functional characteristics in various diseases, including liver disease, diabetes, stroke, Duchenne muscular dystrophy, ovarian-related disease, myocardial infarction, Asherman syndrome, Alzheimer’s disease, acute lung injury, cutaneous wound, endometriosis, and neurodegenerative diseases. Subsequently, the clinical potential of MenSCs is investigated. There is a need for a deeper understanding of its immunomodulatory and diagnostic properties with safety concern on a variety of environmental conditions (such as epidemiological backgrounds, age, hormonal status, and pre-contraceptive). In summary, MenSC has a great potential for reducing mortality and improving the quality of life of severe patients. As a kind of adult stem cells, MenSCs have multiple properties in treating a variety of diseases in regenerative medicine for future clinical applications.

Alleviation of hepatic fibrosis and autophagy via inhibition of transforming growth factor-β1/Smads pathway through shikonin

BACKGROUND AND AIM

Liver fibrosis is a worldwide clinical challenge during the progression of chronic liver disease to liver cirrhosis. Shikonin is extracted from the root of Lithospermum erythrorhizon with antioxidant, anti-inflammatory, anticancer, and wound-healing properties. The study aims to investigate the protective effect of shikonin on liver fibrosis and its underlying mechanism.

METHODS

Two liver fibrosis models were established in male C57 mice by intraperitoneal injection of CCl₄ or bile duct ligation. Shikonin was administered orally three times weekly at a dose of 2.5 or 5 mg/kg. Protein and mRNA expressions were assayed by quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemical staining.

RESULTS

Shikonin significantly inhibited activation of hepatic stellate cells and extracellular matrix formation by downregulating the transforming growth factor-β1 expression and maintaining the normal balance between metalloproteinase-2 and tissue inhibitor of metalloproteinase-1. Shikonin also decreased hepatic stellate cell energy production by inhibiting autophagy.

CONCLUSIONS

The results confirmed that shikonin attenuated liver fibrosis by downregulating the transforming growth factor-β1/Smads pathway and inhibiting autophagy.

Spontaneous Cancers, But Not Many Induced Ones in Animals, Resemble Semi-New Organisms that Possess a Unique Programmed Cell Death Mode Different from Apoptosis, Senescent Death, Necrosis and Stress-Induced Cell Death

There are four basic cell death modes in animals, i.e. physiological senescent death (SD) and apoptosis as well as pathological necrosis and stress-induced cell death (SICD). There have been numerous publications describing “apoptosis” in cancer, mostly focused on killing cancer cells using radio- or chemo-therapy, with few on exploring how cancer cells die naturally without such treatments. Spontaneous benign or malignant neoplasms are immortal and autonomous, but they still retain some allegiance to their parental tissue or organ and thus are still somewhat controlled by the patient's body. Because of these properties of immortality, semi-autonomy, and semi-allegiance to the patient's body, spontaneous tumors have no redundant cells and resemble “semi-new organisms” parasitizing the patients, becoming a unique tissue type possessing a hitherto unannotated cell death mode besides SD, apoptosis, necrosis and SICD. Particularly, apoptosis aims to expunge redundant cells, whereas this new mode does not. In contrast to spontaneous tumors, many histologically malignant tumors induced in experimental animals, before they reach an advanced stage, regress after withdrawal of the inducer. This mortal and non-autonomous nature disqualifies these animal lesions as authentic neoplasms and as semi-new organisms but makes them a good tissue type for apoptosis studies. Ruminating over cell death in spontaneous cancers and many inauthentic tumors induced in animals from these new slants makes us realize that “whether cancer cells undergo apoptosis” is not an easy question with a simple answer. Our answer is that cancer cells have an uncharacterized programmed cell death mode, which is not apoptosis.