An adenosine derivative compound, IFC305, reverses fibrosis and alters gene expression in a pre-established CCl4-induced rat cirrhosis

An adenosine derivative promotes mitochondrial supercomplexes reorganization and restoration of mitochondria structure and bioenergetics in a diethylnitrosamine-induced hepatocellular carcinoma model

Hepatocellular carcinoma (HCC) progression is associated with dysfunctional mitochondria and bioenergetics impairment. However, no data about the relationship between mitochondrial supercomplexes (hmwSC) formation and ATP production rates in HCC are available. Our group has developed an adenosine derivative, IFC-305, which improves mitochondrial function, and it has been proposed as a therapeutic candidate for HCC. We aimed to determine the role of IFC-305 on both mitochondrial structure and bioenergetics in a sequential cirrhosis-HCC model in rats. Our results showed that IFC-305 administration decreased the number and size of liver tumors, reduced the expression of tumoral markers, and reestablished the typical architecture of the hepatic parenchyma. The livers of treated rats showed a reduction of mitochondria number, recovery of the mtDNA/nDNA ratio, and mitochondrial length. Also, IFC-305 increased cardiolipin and phosphatidylcholine levels and promoted hmwSC reorganization with changes in the expression levels of hmwSC assembly-related genes. IFC-305 in HCC modified the expression of several genes encoding elements of electron transport chain complexes and increased the ATP levels by recovering the complex I, III, and V activity. We propose that IFC-305 restores the mitochondrial bioenergetics in HCC by normalizing the quantity, morphology, and function of mitochondria, possibly as part of its hepatic restorative effect.

Liver fibrotic development is reduced through inflammation prevention by an adenosine derivative compound

BACKGROUND

Liver fibrosis is a global health problem, and studying its development provides important information to address its treatment. Here, we characterized the effects of an adenosine compound (IFC-305) on preventing fibrosis and liver inflammation.

METHODS

We studied the impact of IFC-305 on a carbon tetrachloride-induced liver fibrosis model in Wistar male rats at 4, 6, and 8 weeks. The effects were characterized by liver tissue histology, macrophages identification by flow cytometry with CD163+/CD11b/c+ antibodies, hepatic and plasmatic cytokine levels employing MILLIPLEX MAP and ELISA, Col1a1 and Il6 gene expression by RTqPCR, lipoperoxidation by TBARS reaction, and reactive oxygen species using 2'-7'dichlorofluorescin diacetate.

RESULTS

CCl4-induced liver fibrosis and inflammation were significantly reduced in rats treated with IFC-305 at 6 and 8 weeks. In addition, we observed diminished expression of Col1a1; a decrease in the inflammatory cytokines IL-1β, IL-6, MCP-1, TNF-α, and IL-4 a; reduction in inflammatory macrophages; inhibition of lipoperoxidation; and ROS production in Kupffer cells.

CONCLUSION

This study showed that IFC-305 can inhibit liver fibrosis establishment by regulating the immune response during CCl4-induced damage. The immunomodulatory action of IFC-305 supports its use as a potential therapeutic strategy for preventing liver fibrosis.

IFC-305 attenuates renal ischemia-reperfusion injury by promoting the production of hydrogen sulfide (H2S) via suppressing the promoter methylation of cystathionine γ-lyase (CSE)

Renal ischemia-reperfusion (I/R) injury is characterized by elevated expression of homocysteine and decreased production of hydrogen sulfide (H₂S). Cystathionine γ-lyase (CSE) is a key factor in the onset of renal I/R injury, while IFC-305 can regulate the expression of CSE via epigenetic modification. Animal and cellular models of I/R were established in this work, followed by H&E staining to evaluate the extent of renal tissue injury under distinct conditions. Several methods, including ELISA, qPCR and Western blot, were used to analyze the levels of creatinine, CSE and H₂S in various I/R models. Bisulfite sequencing PCR was used to evaluate the level of DNA methylation. The severity of the renal injury was significantly elevated in I/R rats and alleviated by the IFC-305 treatment. The level of Hcy was increased in the renal tissue and peripheral blood of I/R rats, while the IFC-305 treatment inhibited the expression of homocysteine (Hcy). Mechanistically, the DNA methylation in the CSE promoter was dramatically enhanced in I/R rats and cells, while the IFC-305 treatment reduced the level of DNA methylation in the CSE promoter. Moreover, the IFC-305 increased the concentration of H₂S, which was reduced in I/R rats and cells. Finally, I/R rats and cells showed aberrantly high levels of MDA and superoxide, while the IFC-305 treatment reduced the levels of malondialdehyde (MDA) and superoxide. IFC-305, an adenosine derivative, promoted the production of H₂S and attenuated renal injury in cellular and animal models of renal I/R by modifying the methylation status of the CSE promoter.

Therapeutic Effects of Berberine on Liver Fibrosis are associated With Lipid Metabolism and Intestinal Flora

Liver cirrhosis is a form of liver fibrosis resulting from chronic hepatitis caused by various liver diseases, such as viral hepatitis, alcoholic liver damage, nonalcoholic steatohepatitis, autoimmune liver disease, and by parasitic diseases such as schistosomiasis. Liver fibrosis is the common pathological base and precursors of cirrhosis. Inflammation and disorders of lipid metabolism are key drivers in liver fibrosis. Studies have determined that parts of the arachidonic acid pathway, such as its metabolic enzymes and biologically active products, are hallmarks of inflammation, and that aberrant peroxisome proliferator-activated receptor gamma (PPARγ)-mediated regulation causes disorders of lipid metabolism. However, despite the ongoing research focus on delineating the mechanisms of liver fibrosis that underpin various chronic liver diseases, effective clinical treatments have yet to be developed. Berberine (BBR) is an isoquinoline alkaloid with multiple biological activities, such as anti-inflammatory, anti-bacterial, anti-cancer, and anti-hyperlipidemic activities. Many studies have also found that BBR acts via multiple pathways to alleviate liver fibrosis. Furthermore, the absorption of BBR is increased by nitroreductase-containing intestinal flora, and is strengthened via crosstalk with bile acid metabolism. This improves the oral bioavailability of BBR, thereby enhancing its clinical utility. The production of butyrate by intestinal anaerobic bacteria is dramatically increased by BBR, thereby amplifying butyrate-mediated alleviation of liver fibrosis. In this review, we discuss the effects of BBR on liver fibrosis and lipid metabolism, particularly the metabolism of arachidonic acid, and highlight the potential mechanisms by which BBR relieves liver fibrosis through lipid metabolism related and intestinal flora related pathways. We hope that this review will provide insights on the BBR-based treatment of liver cirrhosis and related research in this area, and we encourage further studies that increase the ability of BBR to enhance liver health.

cAMP Signaling in Pathobiology of Alcohol Associated Liver Disease

The importance of cyclic adenosine monophosphate (cAMP) in cellular responses to extracellular signals is well established. Many years after discovery, our understanding of the intricacy of cAMP signaling has improved dramatically. Multiple layers of regulation exist to ensure the specificity of cellular cAMP signaling. Hence, disturbances in cAMP homeostasis could arise at multiple levels, from changes in G protein coupled receptors and production of cAMP to the rate of degradation by phosphodiesterases. cAMP signaling plays critical roles in metabolism, inflammation and development of fibrosis in several tissues. Alcohol-associated liver disease (ALD) is a multifactorial condition ranging from a simple steatosis to steatohepatitis and fibrosis and ultimately cirrhosis, which might lead to hepatocellular cancer. To date, there is no FDA-approved therapy for ALD. Hence, identifying the targets for the treatment of ALD is an important undertaking. Several human studies have reported the changes in cAMP homeostasis in relation to alcohol use disorders. cAMP signaling has also been extensively studied in in vitro and in vivo models of ALD. This review focuses on the role of cAMP in the pathobiology of ALD with emphasis on the therapeutic potential of targeting cAMP signaling for the treatment of various stages of ALD.

Genome-wide 5-hydroxymethylcytosine (5hmC) emerges at early stage of in vitro differentiation of a putative hepatocyte progenitor

A basic question linked to differential patterns of gene expression is how cells reach different fates despite using the same DNA template. Since 5-hydroxymethylcytosine (5hmC) emerged as an intermediate metabolite in active DNA demethylation, there have been increasing efforts to elucidate its function as a stable modification of the genome, including a role in establishing such tissue-specific patterns of expression. Recently we described TET1-mediated enrichment of 5hmC on the promoter region of the master regulator of hepatocyte identity, HNF4A, which precedes differentiation of liver adult progenitor cells in vitro. Here, we studied the genome-wide distribution of 5hmC at early in vitro differentiation of human hepatocyte-like cells. We found a global increase in 5hmC as well as a drop in 5-methylcytosine after one week of in vitro differentiation from bipotent progenitors, at a time when the liver transcript program is already established. 5hmC was overall higher at the bodies of overexpressed genes. Furthermore, by modifying the metabolic environment, an adenosine derivative prevents 5hmC enrichment and impairs the acquisition of hepatic identity markers. These results suggest that 5hmC could be a marker of cell identity, as well as a useful biomarker in conditions associated with cell de-differentiation such as liver malignancies.

Purinergic signaling in hepatic disease

Extracellular purines (ATP and adenosine) are ubiquitous intercellular messengers. During tissular damage, they function as damage-associated molecular patterns (DAMPs). In this context, purines announce tissue alterations to initiate a reparative response that involve the formation of the inflammasome complex and the recruitment of specialized cells of the immune system. The present review focuses on the role of the purinergic system in liver damage, mainly during the onset and development of fibrosis. After hepatocellular injury, extracellular ATP promotes a signaling cascade that ameliorates tissue alterations to restore the hepatic function. However, if cellular damage becomes chronic, ATP orchestrates an aberrant reparative process that results in severe liver diseases such as fibrosis and cirrhosis. ATP and adenosine, their receptors, and extracellular ectonucleotidases are mediators of unique processes that will be reviewed in detail.

An adenosine derivative (IFC-305) reduced the risk of radiation-induced intestinal toxicity in the treatment of colon cancer by suppressing the methylation of PPAR-r promoter

BACKGROUND

IFC-305, an adenosine derivative, has been proved to exert a therapeutic effect on radiation-induced intestinal toxicity in colon cancer (CC). The aim of the present study was to investigate the underlying molecular mechanism of protective role of IFC-305 in CC by modifying the methylation of peroxisome proliferator-activated receptor (PPAR)-r promoter.

METHOD

Peripheral blood and cancerous tissues samples were collected from the CC patients. Irradiation (IR) mice models were established in comparison with control mice accordingly. Bisulfite sequencing, real-time PCR, Western-blot analysis, immunohistochemistry (IHC) and hematoxylin eosin (HE) staining were performed upon both human and animal samples.

RESULT

The results upon the human CC samples demonstrated that the level of methylation of PPAR-r promoter in methylated patients was increased, while the risk of radiation-induced intestinal toxicity in methylated patients was also increased compared with unmethylated patients. Also, the PPAR-r mRNA/protein expression was lower in methylated patients compared with unmethylated patients, thus indicating the presence of PPAR-r promoter methylation repressed PPAR-r expression in vivo. Moreover, in the mice models, IFC-305 treatment partially alleviated radiation-induced toxicity in the columnar epithelia and tubular glands of IR mice, and villus height and the number/circumference of crypts were also increased while the relative number of inflammatory cells was decreased in IR + IFC-305 mice group compared with the control mice. Compared with the control group, the levels of PPAR-r mRNA/protein expression were significantly decreased in IR mice, while the presence of IFC-305 exerted therapeutic effect upon IR rats via elevating the PPAR-r mRNA/protein expression to a certain extent.

CONCLUSION

In this study, we demonstrated the relationship between PPAR-r promoter methylation and the risk of radiation-induced intestinal toxicity via studying the clinical samples collected from CC patients. And the study upon mice models suggested that the administration of IFC-305 could alleviate radiation-induced intestinal toxicity through decreasing the methylation of PPAR-r promoter and enhancing the expression of PPAR-r in IR mice.

Nucleotides and nucleoside signaling in the regulation of the epithelium to mesenchymal transition (EMT)

The epithelium-mesenchymal transition (EMT) is an important process of cell plasticity, consisting in the loss of epithelial identity and the gain of mesenchymal characteristics through the coordinated activity of a highly regulated informational program. Although it was originally described in the embryonic development, an important body of information supports its role in pathology, mainly in cancerous and fibrotic processes. The purinergic system of inter-cellular communication, mainly based in ATP and adenosine acting throughout their specific receptors, has emerged as a potent regulator of the EMT in several pathological entities. In this context, cellular signaling associated to purines is opening the understanding of a new element in the complex regulatory network of this phenotypical differentiation process. In this review, we have summarized recent information about the role of ATP and adenosine in EMT, as a growing field with high therapeutic potential.

Functional, Metabolic, and Dynamic Mitochondrial Changes in the Rat Cirrhosis-Hepatocellular Carcinoma Model and the Protective Effect of IFC-305

Background: Mitochondrion is an important metabolic and energetic organelle that regulates several cellular processes. Mitochondrial dysfunction has been related to liver diseases including hepatocellular carcinoma. As a result, the energetic demand is not properly supplied and mitochondrial morphologic changes have been observed, resulting in an altered metabolism. We previously demonstrated the chemopreventive effect of the hepatoprotector IFC-305. Aim: In this work we aimed to evaluate the functional, metabolic, and dynamic mitochondrial alterations in the sequential model of cirrhosis-hepatocellular carcinoma induced by diethylnitrosamine in rats and the possible beneficial effect of IFC-305. Methods: Experimental groups of rats were formed to induce cirrhosis-hepatocellular carcinoma and to assess the IFC-305 effect during cancer development and progression through the evaluation of functional, metabolic, and dynamic mitochondrial parameters. Results: In this experimental model, dysfunctional mitochondria were observed and suspension of the diethylnitrosamine treatment was not enough to restore them. Administration of IFC-305 maintained and restored the mitochondrial function and regulated parameters implicated in metabolism as well as the mitochondrial dynamics modified by diethylnitrosamine intoxication. Conclusion: This study supports IFC-305 as a potential hepatocellular carcinoma treatment or as an adjuvant in chemotherapy.

Cancer chemoprevention by an adenosine derivative in a model of cirrhosis-hepatocellular carcinoma induced by diethylnitrosamine in rats

Hepatocellular carcinoma is one of the most common cancers, and approximately 80% develop from cirrhotic livers. We have previously shown that the aspartate salt of adenosine prevents and reverses carbon tetrachloride–induced liver fibrosis in rats. Considering the hepatoprotective role of this adenosine derivative in fibrogenesis, we were interested in evaluating its effect in a hepatocarcinogenesis model induced by diethylnitrosamine in rats, where multinodular cancer is preceded by cirrhosis. Rats were injected with diethylnitrosamine for 12 weeks to induce cirrhosis and for 16 weeks to induce hepatocarcinogenesis. Groups of rats were treated with aspartate salt of adenosine from the beginning of carcinogen administration for 12 or 18 weeks total, and another group received the compound from weeks 12 to 18. Fibrogenesis was estimated and the proportion of preneoplastic nodules and tumors was measured. The apoptotic and proliferation rates in liver tissues were evaluated, as well as the expression of cell signaling and cell cycle proteins participating in hepatocarcinogenesis. The adenosine derivative treatment reduced diethylnitrosamine-induced collagen expression and decreased the proportion of nodules positive for the tumor marker γ-glutamyl transferase. This compound down-regulated the expression of thymidylate synthase and hepatocyte growth factor, and augmented the protein level of the cell cycle inhibitor p27; these effects could be part of its chemopreventive mechanism. These findings suggest a hepatoprotective role of aspartate salt of adenosine that could be used as a therapeutic compound in the prevention of liver tumorigenesis as described earlier for hepatic fibrosis.

The hepatic phosphatidylcholine transporter ABCB4 as modulator of glucose homeostasis

The hepatic phosphatidylcholine (PC) transporter ATP-binding cassette (ABC) B4 flops PC from hepatocytes into bile, and its dysfunction causes chronic cholestasis and fibrosis. Because a nuclear receptor-dependent PC pathway has been determined to exert antidiabetic effects, we now analyzed the role of ABCB4 in glucose metabolism. We bred congenic Abcb4-knockout (Abcb4(-/-)) mice on the fibrosis-susceptible BALB/cJ background. Knockout mice and wild-type controls were phenotyped by measuring plasma glucose concentrations, intraperitoneal glucose tolerance, hepatic RNA expression profiles, and liver histology. In addition, 4 procholestatic ABCB4 gene variants were correlated with blood glucose levels in 682 individuals from 2 independent European cohorts. Systemic glucose levels differ significantly between Abcb4(-/-) mice and wild-type controls, and knockout mice display improved glucose tolerance with significantly lower area under the curve values on intraperitoneal glucose challenge. Of note, hepatic expression of the antidiabetic nuclear receptor 5A2 (LRH-1) is induced consistently in Abcb4(-/-) mice, and its specific rare PC ligands are detected in liver by mass spectrometry imaging. In humans, serum glucose levels are associated significantly with the common ABCB4 variant c.711A>T. In summary, ABCB4 might play a critical role in glucose homeostasis in mice and humans. We speculate that the effects could be mediated via LRH-1-dependent PC pathways.

Recovery of the Cell Cycle Inhibition in CCl(4)-Induced Cirrhosis by the Adenosine Derivative IFC-305

Introduction. Cirrhosis is a chronic degenerative illness characterized by changes in normal liver architecture, failure of hepatic function, and impairment of proliferative activity. The aim of this study is to know how IFC-305 compound induces proliferation of the liver during reversion of cirrhosis. Methods. Once cirrhosis has been installed by CCl(4) treatment for 10 weeks in male Wistar rats, they were divided into four groups: two received saline and two received the compound; all were euthanized at 5 and 10 weeks of treatment. Liver homogenate, mitochondria, and nucleus were used to measure cyclins, CDKs, and cell cycle regulatory proteins PCNA, pRb, p53, E2F, p21, p27, HGF, liver ATP, and mitochondrial function. Results. Diminution and small changes were observed in the studied proteins in the cirrhotic animals without treatment. The IFC-305-treated rats showed a clear increase in most of the proteins studied mainly in PCNA and CDK6, and a marked increased in ATP and mitochondrial function. Discussion/Conclusion. IFC-305 induces a recovery of the cell cycle inhibition promoting recovery of DNA damage through the action of PCNA and p53. The increase in energy and preservation of mitochondrial function contribute to recovering the proliferative function.

Prevention of in vitro hepatic stellate cells activation by the adenosine derivative compound IFC305

We have previously shown that adenosine and the aspartate salt of adenosine (IFC305) reverse pre-established CCl(4)-induced cirrhosis in rats. However, their molecular mechanism of action is not clearly understood. Hepatic stellate cells (HSC) play a pivotal role in liver fibrogenesis leading to cirrhosis, mainly through their activation, changing from a quiescent adipogenic state to a proliferative myofibrogenic condition. Therefore, we decided to investigate the effect of IFC305 on primary cultured rat HSC. Our results reveal that this compound suppressed the activation of HSC, as demonstrated by the maintenance of a quiescent cell morphology, including lipid droplets content, inhibition of α-smooth muscle actin (α-SMA) and collagen α1(I) expression, and up-regulation of MMP-13, Smad7, and PPARγ expression, three key antifibrogenic genes. Furthermore, IFC305 was able to repress the platelet-derived growth factor (PDGF)-induced proliferation of HSC. This inhibition was independent of adenosine receptors stimulation; instead, IFC305 was incorporated into cells by adenosine transporters and converted to AMP by adenosine kinase. On the other hand, addition of pyrimidine ribonucleoside as uridine reversed the suppressive effect of IFC305 on the proliferation and activation of HSC, suggesting that intracellular pyrimidine starvation would be involved in the molecular mechanism of action of IFC305. In conclusion, IFC305 inhibits HSC activation and maintains their quiescence in vitro; these results could explain in part the antifibrotic liver beneficial effect previously described for this compound on the animal model.