Model Of Cholestasis Research Articles

Yinchen decoction protects against cholic acid diet-induced cholestatic liver injury in mice through liver and ileal FXR signaling

Ethnopharmacological relevanceCholestasis is a pathophysiological syndrome characterized by the accumulation of bile acids (BAs) that leads to severe liver disease. Artemisia capillaris is documented in Chinese Pharmacopoeia as the authentic resources for Yinchen. Although Yinchen (Artemisia capillaris Thunb.) decoction (YCD) has been used in China for thousands of years to treat jaundice, the underlying mechanisms to ameliorate cholestatic liver injury have not been elucidated. Aim of the studyTo investigate the molecular mechanism of how YCD protects against 1% cholic acid (CA) diet-induced intrahepatic cholestasis through FXR signaling. Materials and methodsWild-type and Fxr-deficient mice were fed a diet containing 1% CA to establish the intrahepatic cholestasis model. The mice received low-, medium-, or high-dose YCD for 10 days. Plasma biochemical markers were analyzed, liver injury was identified by histopathology, and hepatic and plasma BA content was analyzed. Western blot was used to determine the expression levels of transporters and enzymes involved in BA homeostasis in the liver and intestine. ResultsIn wild-type mice, YCD significantly improved plasma transaminase levels, multifocal hepatocellular necrosis, and hepatic and plasma BA contents, upregulated the expression of hepatic FXR and downstream target enzymes and transporters. Meanwhile, YCD significantly induced the expressions of intestinal FXR and FGF15 and hepatic FGFR4. In contrast, the hepatic protective effect of YCD on cholestasis was abolished in Fxr-deficient mice. ConclusionYCD protects against cholestatic liver injury induced by a CA diet by restoring the homeostasis of BAs via activation of the liver FXR/SHP and ileal FXR/FGF15 signaling pathways. Furthermore, chlorogenic acid and caffeic acid may be the pharmacological agents in YCD responsible for protecting against cholestatic liver injury.

Exploration of the Molecular Basis of Forsythia Fruit in the Prevention and Treatment of Cholestatic Liver Injury through Network Pharmacology and Molecular Docking.

Forsythia fruit, edible fruit of Forsythia suspensa (Thunb.) Vahl, which has been found to be effective in treating cholestasis. However, its key component for alleviating cholestasis has not been determined. In this study, four representative active ingredients in forsythia fruit were selected. Through network pharmacology and molecular docking technology, we tried to find the key component for its treatment of cholestasis. Furthermore, the model of cholestasis in mice was established to verify the protective effect of the key component on cholestasis. Network pharmacology and molecular docking showed that forsythoside A (FTA) is the key component of forsythia fruit in the treatment of cholestasis. In vivo experiments revealed that FTA treatment could alleviate liver injury, dysfunction, and collagen deposition induced by cholestasis in mice. At the same time, FTA treatment inhibited inflammatory factor release and fibrosis-related factor expression. In addition, FTA treatment also reduced MMP-2, TLR4, MYD88, NF-κB p65, and p-NF-κB p65 protein expression. In conclusion, FTA, a key component of forsythia fruit, alleviated liver damage and fibrosis caused by cholestasis via inhibiting the TLR4/NF-κB pathway, extracellular matrix accumulation, and inflammatory cytokine expression. The research results could provide a scientific reference for the development of forsythia fruit as a drug or functional food to prevent and treat cholestasis.

A3907, a systemic ASBT inhibitor, improves cholestasis in mice by multiorgan activity and shows translational relevance to humans.

Cholestasis is characterized by intrahepatic accumulation of bile constituents, including bile acids (BAs), which promote liver damage. The apical sodium-dependent BA transporter (ASBT) plays an important role in BA reabsorption and signaling in ileum, bile ducts, and kidneys. Our aim was to investigate the pharmacokinetics and pharmacological activity of A3907, an oral and systemically available ASBT inhibitor in experimental mouse models of cholestasis. In addition, the tolerability, pharmacokinetics, and pharmacodynamics of A3907 were examined in healthy humans. A3907 was a potent and selective ASBT inhibitor in vitro. In rodents, orally administered A3907 distributed to the ASBT-expressing organs, that is, ileum, liver, and kidneys, and dose dependently increased fecal BA excretion. A3907 improved biochemical, histological, and molecular markers of liver and bile duct injury in Mdr2-/- mice and also had direct protective effects on rat cholangiocytes exposed to cytotoxic BA concentrations in vitro . In bile duct ligated mice, A3907 increased urinary BA elimination, reduced serum BA levels, and prevented body weight loss, while improving markers of liver injury. A3907 was well tolerated and demonstrated target engagement in healthy volunteers. Plasma exposure of A3907 in humans was within the range of systemic concentrations that achieved therapeutic efficacy in mouse. The systemic ASBT inhibitor A3907 improved experimental cholestatic disease by targeting ASBT function at the intestinal, liver, and kidney levels, resulting in marked clearance of circulating BAs and liver protection. A3907 is well tolerated in humans, supporting further clinical development for the treatment of cholestatic liver diseases.

Correction to: Pulmonary inflammation, oxidative stress, and fibrosis in a rat model of cholestasis: the potential protective properties of the dipeptide carnosine

Correction to: Pulmonary inflammation, oxidative stress, and fibrosis in a rat model of cholestasis: the potential protective properties of the dipeptide carnosine

Melatonin attenuates cholestatic liver injury via inhibition of the inflammatory response.

Melatonin, an indole neurohormone secreted mainly by the pineal gland, has been found to be involved in a variety of liver diseases. However, the underlying mechanism by which melatonin ameliorates cholestatic liver injury is not fully understood. In this study, we investigated the mechanism by which melatonin attenuates cholestatic liver injury via inhibition of the inflammatory response. We measured the levels of serum melatonin in patients with obstructive cholestasis (n = 9), patients with primary biliary cholangitis (PBC) (n = 11), and control patients (n = 7). We performed experiments with C57BL/6J mice treated with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) and melatonin to verify the role of melatonin in the mouse model of cholestasis. Primary mouse hepatocytes were used for in vitro studies to study the mechanisms of action of melatonin in cholestasis. The levels of serum melatonin were markedly increased and negatively correlated with serum markers of liver injury in cholestatic patients. As expected, oral administration of melatonin significantly attenuated cholestasis-induced liver inflammation and fibrosis in 0.1% DDC diet-fed mice. Further mechanistic studies in cholestatic mice and primary hepatocytes revealed that melatonin reduced the conjugate BA-stimulated expression of cytokines (e.g. Ccl2, Tnfα, and Il6) through the ERK/Egr1 signalling pathway in these models. The levels of serum melatonin are significantly elevated in cholestatic patients. Melatonin treatment ameliorates cholestatic liver injury by suppressing the inflammatory response in vivo and in vitro. Therefore, melatonin is a promising novel therapeutic strategy for cholestasis.

Granulocyte colony-stimulating factor reduces biliary fibrosis and ductular reaction in a mouse model of chronic cholestasis

BackgroundBiliary atresia is a rare congenital bile duct disease that is the leading cause of liver fibrosis in neonates. Granulocyte colony-stimulating factor (GCSF) is a potential therapy for hepatocellular diseases, but data on GCSF for cholestatic conditions remain limited. Materials and methodsThe current study examines the role of GCSF in improving bile duct obstruction in mice. Two doses were administered: 10.0 μg/kg/day and 61.5 μg/kg/day, which is the animal equivalent dose of 5.0 μg/kg in humans. Seven days (D7) after bile duct ligation (BDL), Swiss mice were treated with phosphate buffered saline or GCSF for 5 days. The intrahepatic adaptive response of BDL mice was evaluated on postsurgical days D12, D19, and D26. ResultsTreatment with 61.5 μg/kg of GCSF resulted in a significant increase in circulating leukocytes and neutrophils on D12. Amelioration of liver injury, as shown by reduced aspartate aminotransferase levels, increased albumin levels and survival rate, as well as reduced intrahepatic inflammation and hepatic myeloperoxidase expression, downregulated ductular proliferation, periportal fibroblast activation, and fibrosis, enhanced expressions of hepatocyte growth factor, peroxisome proliferator-activated receptor-alpha, and ki67, and suppressed expression of cleaved caspase-3 protein, was noted after treatment with 61.5 μg/kg of GCSF. Additionally, GCSF treatment was associated with an increased number of intrahepatic cd3-Sca1+c-Kit+ bone marrow cells. ConclusionsTreatment with 61.5 μg/kg of GCSF resulted in liver regeneration and survival in BDL mice was seen, suggesting its potential use for human liver diseases.

The choleretic role of tauroursodeoxycholicacid exacerbates alpha-naphthylisothiocyanateinduced cholestatic liver injury through the FXR/BSEP pathway.

The aim of this study was to determine the effect of tauroursodeoxycholic acid (TUDCA) on the alpha-naphthylisothiocyanate (ANIT)-induced model of cholestasis in mice. Wild-type and farnesoid X receptor (FXR)-deficient (Fxr-/- ) mice were used to generate cholestasis models by gavage with ANIT. Obeticholic acid (OCA) was used as a positive control. In wild-type mice, treatment with TUDCA for 7days resulted in a dramatic increase in serum levels of alanine aminotransferase (ALT), with aggravation of bile infarcts and hepatocyte necrosis with ANIT-induction. TUDCA activated FXR to upregulate the expression of bile salt export pump (BSEP), increasing bile acids (BAs)-dependent bile flow, but aggravating cholestatic liver injury when bile ducts were obstructed resulting from ANIT. In contrast, TUDCA improved the liver pathology and decreased serum ALT and alkaline phosphatase (ALP) levels in ANIT-induced Fxr-/- mice. Furthermore, TUDCA inhibited the expression of cleaved caspase-3 and reduced the area of terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining in the model mice. TUDCA also upregulated anion exchanger 2 (AE2) protein expression, protecting cholangiocytes against excessive toxic BAs. Our results showed that TUDCA aggravated cholestatic liver injury via the FXR/BSEP pathway when bile ducts were obstructed, although TUDCA inhibited apoptotic activity and protected cholangiocytes against excessive toxic BAs.

Pulmonary inflammation, oxidative stress, and fibrosis in a mouse model of cholestasis: the potential protective properties of the dipeptide carnosine.

Cholestasis is a clinical complication that primarily influences the liver. However, it is well known that many other organs could be affected by cholestasis. Lung tissue is a major organ influenced during cholestasis. Cholestasis-induced lung injury could induce severe complications such as respiratory distress, serious pulmonary infections, and tissue fibrosis. Unfortunately, there is no specific pharmacological intervention against this complication. Several studies revealed that oxidative stress and inflammatory response play a role in cholestasis-induced lung injury. Carnosine (CARN) is a dipeptide found at high concentrations in different tissues of humans. CARN's antioxidant and antiinflammatory properties are repeatedly mentioned in various experimental models. This study aimed to assess the role of CARN on cholestasis-induced lung injury. Rats underwent bile duct ligation (BDL) to induce cholestasis. Broncho-alveolar lavage fluid (BALF) levels of inflammatory cells, pro-inflammatory cytokines, and immunoglobulin were monitored at scheduled intervals (7, 14, and 28days after BDL). Moreover, lung tissue histopathological alterations and biomarkers of oxidative stress were evaluated. A significant increase in BALF inflammatory cells, TNF-α, IL-1β, IL-6, and immunoglobulin-G (IgG) was detected in the BALF of BDL rats. Moreover, lung tissue histopathological changes, collagen deposition, increased TGF-β, and elevated levels of oxidative stress biomarkers were evident in cholestatic animals. It was found that CARN (100 and 500mg/kg, i.p.) significantly alleviated lung oxidative stress biomarkers, inflammatory response, tissue fibrosis, and histopathological alterations. These data indicate the potential protective properties of CARN in the management of cholestasis-induced pulmonary damage. The effects of CARN on inflammatory response and oxidative stress biomarkers seems to play a crucial role in its protective properties in the lung of cholestatic animals.

The Investigation of Therapeutic Implications of Mast Cell Stabilizer Cromolyn Sodium on Cholestasis and Cholestatic Pruritus in Experimental Cholestasis.

Relevant studies have indicated that hepatic mast cells may have potential roles in the progression of cholestasis and cholestasis-induced itch. We aimed to compare the effects of cromolyn sodium and other medications on cholestatic pruritus, serum biochemistry, histamine, total bile acids, autotaxin, liver histopathology, and mast cell distribution in tissues in an experimental cholestasis model conducted by bile duct ligation. Rats received the determined treatment consecutively for 10 days in addition to bile duct ligation. On the 5th and 10th days of the experiment, the rats' itching behaviors were observed for 5 minutes. After 10 days, blood and tissue samples were taken. Significant decreases in serum histamine and autotaxin levels, plasma total bile acids, total bilirubin, and biliary enzymes were reported only in cromolyn sodium-treated rats compared to the control group. In immunohistochemistry of the liver samples, the peribiliary mast cells stained positive for autotaxin. Except for bile duct infarctus, all histopathological findings of cholestasis significantly improved only in cromolyn sodium-treated and sertraline-treated rats. The liver and peritoneal mast cells significantly decreased only in cromolyn sodium-treated rats compared to the control group. On the 10th day of the experiment, the mean duration of itching was significantly lower in all groups, except for naloxone- and ondansetron-treated rats. Cromolyn sodium has promising antipruritic efficacy and provides biochemical and histopathological recovery of the relevant parameters of cholestasis induced by bile duct ligation. For the first time in the literature, we showed that peribiliary mast cells can produce autotaxin, which is a very important pruritogenic signal in the setting of cholestasis.

Kupffer Cells Contested as Early Drivers in the Pathogenesis of Primary Sclerosing Cholangitis

Primary sclerosing cholangitis (PSC) is an idiopathic chronic immune-mediated cholestatic liver disease characterized by fibro-inflammatory bile duct strictures, progressive hepatobiliary fibrosis, and gut-liver axis disruption. The pathophysiology of PSC remains insufficiently characterized, which hampers the development of effective therapies. Hepatic macrophages (MFs) such as Kupffer cells (KCs) are implicated in PSC pathogenesis, but their exact role is unclear. Using the latest markers to discriminate resident KCs (ResKCs) from their monocyte-derived counterparts (MoKCs), and two models of intrahepatic and extrahepatic cholestasis, respectively, this study showed that CLEC4F+TIM4+ ResKCs were depleted after chronic cholestatic liver injury. The infiltrating CLEC4F+TIM4- MoKCs were already enriched during the acute phase of PSC. Transcriptional profiling of hepatic MF subsets during early cholestatic injury indicated that ResKCs were indeed activated and that MoKCs expressed higher levels of pro-inflammatory and proliferative markers compared with those of ResKCs. As indicated in experiments with Clec4fDTR transgenic mice, conditional depletion of KCs, before and during early cholestasis induction, had no effect on the composition of the hepatic myeloid cell pool following injury progression and did not affect disease outcomes. Taken together, these results provide new insights into the heterogeneity of the MF pool during experimental PSC and evidence that depletion of resident and activated KCs during sclerosing cholangitis does not affect disease outcome in mice.

Ellagic acid from whole pomegranate fruit reduces liver injury in a rat model of hepatic cholestasis.

Cholestasis is a health problem, both in humans and animals, which in the disease's course involves oxidative stress, inflammation, and liver fibrosis. EA has been proven to have beneficial effects on various diseases. This study was conducted to determine the effect of EA in protecting liver damage because of cholestasis. In addition, to understand the underlying mechanism of liver damage in rats as a model animal by bile duct ligation (BDL) technique. In this study, male adult rats were used and randomly divided into three treatment groups. S is the sham-operated group, BDL is the group that is treated with BDL and the BDL-EA group is treated with BDL and given EA by gavage at a dose of 60 mg/kg bw/day, starting on the second day after BDL and given for 21 days. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT) were evaluated using spectrophotometer; tumor necrosis factor alpha (TNF-α) and transforming growth factor beta (TGF-β1) were evaluated using sandwich ELISA and histopathological examination using HE and Massion's Trichrome staining. In this study, BDL significantly increased serum levels of AST, ALT, ALP, and hepatic GGT. In addition, BDL also increased levels of TNF-α, and TGF-β1 compared to sham-operated controls. Histological studies in the BDL group also showed that the BDL increased the degree of necro-inflammation and collagen deposition area in the liver compared to the sham-operated group. Administration of EA has been shown to significantly improve liver morpho-function of the liver. I attenuated these changes in the BDL-EA group, where all observed study variables appeared to have improved. EA has been shown to reduce cholestasis that causes liver injury and improves liver enzyme profiles, and is suspected to have occurred because of its activities as an antioxidant, anti-inflammatory, and anti-fibrotic.

Inhibiting Wnt Signaling Reduces Cholestatic Injury by Disrupting the Inflammatory Axis

β-Catenin, the effector molecule of the Wnt signaling pathway, has been shown to play a crucial role in bile acid homeostasis through direct inhibition of farnesoid X receptor (FXR), which has pleiotropic effects on bile acid homeostasis. We hypothesize that simultaneous suppression of β-catenin signaling and activation of FXR in a mouse model of cholestasis will reduce injury and biliary fibrosis through inhibition of bile acid synthesis. To induce cholestasis, we performed bile duct ligation (BDL) on wild-type male mice. Eight hours after surgery, mice received FXR agonists obeticholic acid, tropifexor, or GW-4064 or Wnt inhibitor Wnt-C59. Severity of cholestatic liver disease and expression of target genes were evaluated after either 5 days or 12 days of treatment. We found that although the FXR agonists worsened BDL-induced injury and necrosis after 5 days, Wnt-C59 did not. After 12 days of BDL, Wnt-C59 treatment, but not GW-4064 treatment, reduced both the number of infarcts and the number of inflammatory cells in liver. RNA sequencing analysis of whole livers revealed a notable suppression of nuclear factor kappa B signaling when Wnt signaling is inhibited. We then analyzed transcriptomic data to identify a cholangiocyte-specific signature in our model and demonstrated that Wnt-C59-treated livers were enriched for genes expressed in quiescent cholangiocytes, whereas genes expressed in activated cholangiocytes were enriched in BDL alone. A similar decrease in biliary injury and inflammation occurred in Mdr2 KO mice treated with Wnt-C59. Inhibiting Wnt signaling suppresses cholangiocyte activation and disrupts the nuclear factor kappa B-dependent inflammatory axis, reducing cholestatic-induced injury.

A feasible protocol to profile bile acids in dried blood spots from rats using a UHPLC-MS/MS method combining a surrogate matrix.

Dried blood spot (DBS) sampling is a promising method for microliter blood sample collection with the advantages of convenient transportation, storage and clinical operations. However, it is challenging to develop an analytical protocol to determine endogenous metabolites, such as bile acids (BAs) in DBSs, due to the low-blood-volume character of DBSs and the complex features of filter paper. Herein, we developed a method of fast ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) to profile and quantify BAs in DBSs. The pretreatment methods were optimized and a two-step solvent addition method, where a small amount of water was firstly added to moisten the DBS and then methanol was added, showed high extraction efficiency for multiple BAs in DBSs. The UHPLC-MS/MS conditions were optimized and 35BAs in different types could be profiled with good resolution and quantified with acceptable precision and accuracy. Preparation of a DBS surrogate matrix without endogenous BAs has been well developed using rat erythrocytes in BSA solution and showed good performance on both the signal suppression/enhancement percentage and parallelism assessment evaluation of three different stable-isotope-labeled (SIL) BAs. The established protocol was successfully applied to profile BAs in DBSs of intrahepatic cholestasis model and healthy control rats with good repeatability. To our knowledge, it is the first time that 35 BAs in DBSs could be well profiled and an appropriate DBS surrogate matrix has been developed. This protocol presents future-oriented applications of DBSs for relevant preclinical studies to profile BAs and probe biomarkers.

The bile acid receptor TGR5 and cholestasis

During liver injury and cholestasis, the mechanisms allowing the organ to protect itself with the aim of maintaining biliary homeostasis are not completely understood. Central to their biological roles, bile acids (BAs) and their receptors constitute a signaling network with multiple molecular and cellular impacts on both liver repair and protection from BA overload. BA signal through nuclear [mainly farnesoid X receptor (FXR)] and membrane [mainly G protein-coupled BA receptor 1 (GPBAR-1), aka Takeda G protein-coupled receptor 5 (TGR5)] receptors, in which activation elicits a wide array of biological responses. So far, most of the studies have been focused on FXR signaling as hepato-protective, TGR5 being less explored to this regard. While the liver faces massive and potentially harmful BA overload during cholestasis, it is crucial to understand that BAs induce also protective responses contributing not only to reduce the inflammatory burden, but also to spare liver cells and their repair capacities. Based on the available literature, the TGR5 BA receptor protects the liver in the cholestatic context and counteracts BA overload with the aim of restoring biliary homeostasis mainly through the control of inflammatory processes, biliary epithelial barrier permeability, and BA pool composition. Mouse experimental models of cholestasis reveal that the lack of TGR5 was associated with exacerbated inflammation and necrosis, leaky biliary epithelium, and excessive BA pool hydrophobicity, resulting in biliary cell and parenchymal insult, and compromising optimal restoration of biliary homeostasis and liver repair. There are thus widely opened translational perspectives with the aim of targeting TGR5-related signaling or biological responses to trigger protection of the cholestatic liver.

Transcriptome and Gut Microbiota Profiling Analysis of ANIT-Induced Cholestasis and the Effects of Da-Huang-Xiao-Shi Decoction Intervention.

Cholestasis is characterized by bile acid (BA) circulation disorders, which is usually related to damage of hepatocyte barrier function. Currently, patients with cholestasis face several obstacles in seeking diagnosis and therapy. Da-Huang-Xiao-Shi decoction (DHXSD) is an ancient classic formula that has been used clinically for cholestasis treatment. Nevertheless, the underlying biological activities and therapeutic mechanisms remain unclear. In this study, an alpha-naphthylisothiocyanate (ANIT)-induced cholestasis rat model was established to examine the anticholestatic effects of DHXSD using histopathological and molecular analyses. Transcriptomic analysis combined with 16S rRNA gene sequencing analysis was systematically applied to study the mechanism of action of DHXSD. Simultaneously, the effect of DHXSD on gut microbiota, short-chain fatty acids (SCFAs), and intestinal barrier function were evaluated based on the ANIT-induced cholestasis model in rats. The results showed that DHXSD effectively attenuated ANIT-induced cholestasis by reducing liver function indicators (alanine transaminase [ALT], P < 0.05; alkaline phosphatase [ALP], P < 0.05; total bile acid [TBA], P < 0.01; γ-glutamyl transpeptidase [GGT], P < 0.001) and levels of hepatotoxicity-related enzymes (P < 0.05), thus improving the recovery of histopathological injuries, and regulating levels of inflammatory cytokines (P < 0.05). In addition, 16S rRNA gene sequencing analysis combined with intestinal barrier function analysis revealed that the DHXSD significantly ameliorated ANIT-induced gut microbiota dysbiosis. Significantly altered genes in the model and treatment groups were screened using transcriptomic analysis. Sixty-eight genes and four microbial genera were simultaneously altered with opposing trends in variation after ANIT and DHXSD treatments. We built a framework for predicting targets and host-microbe interaction mechanisms, as well as identifying alternative treatment for cholestasis, which should be validated further for clinical application. In conclusion, DHXSD appears to be a promising agent for protection against liver injury. IMPORTANCE Cholestasis is a serious manifestation of liver diseases resulting in liver injury, fibrosis, and liver failure with limited therapies. To date, only ursodeoxycholic acid (UDCA) has been approved by the U.S. Food and Drug Administration for the treatment of cholestasis. However, approximately one-third of patients with cholestasis are unresponsive to UDCA. Therefore, it is urgent to search for appropriate therapeutic agents for restoring stoppage status of the bile components to treat cholestasis. In this study, we investigated how the microbiome and transcriptome data sets correlated with each other to clarify the role of microbiome alterations in host metabolism. In combination, this research offers potential molecular biomarkers that should be validated for more accurate diagnosis of cholestasis and the clinical utilisation of gut microbiota as a target for treatment.

This Month in AJP

The cellular mechanisms leading to cognitive symptoms in rodent bile duct ligation (BDL) models of cholestasis are unclear. Using BDL mice and human neuronal cell cultures, Gee et al (Am J Pathol, AJPA-D-22-00224) studied these mechanisms. BDL reduced spatial learning capabilities as well as exhibited cellular changes, which were partly restored by treatment with obeticholic acid (OCA)—farnesoid X receptor (FXR) agonist and a clinically approved treatment agent. OCA therapy or FXR agonism may limit cholestasis-induced neuronal senescence.

Anti–Cholestatic Therapy with Obeticholic Acid Improves Short-Term Memory in Bile Duct–Ligated Mice

Patients with cholestatic liver disease, including those with primary biliary cholangitis, can experience symptoms of impaired cognition or brain fog. This phenomenon remains unexplained and is currently untreatable. Bile duct ligation (BDL) is an established rodent model of cholestasis. In addition to liver changes, BDL animals develop cognitive symptoms early in the disease process (before development of cirrhosis and/or liver failure). The cellular mechanisms underpinning these cognitive symptoms are poorly understood. Herein, the study explored the neurocognitive symptom manifestations, and tested potential therapies, in BDL mice, and used human neuronal cell cultures to explore translatability to humans. BDL animals exhibited short-term memory loss and showed reduced astrocyte coverage of the blood-brain barrier, destabilized hippocampal network activity, and neuronal senescence. Ursodeoxycholic acid (first-line therapy for most human cholestatic diseases) did not reverse symptomatic or mechanistic aspects. In contrast, obeticholic acid (OCA), a farnesoid X receptor agonist and second-line anti-cholestatic agent, normalized memory function, suppressed blood-brain barrier changes, prevented hippocampal network deficits, and reversed neuronal senescence. Co-culture of human neuronal cells with either BDL or human cholestatic patient serum induced cellular senescence and increased mitochondrial respiration, changes that were limited again by OCA. These findings provide new insights into the mechanism of cognitive symptoms in BDL animals, suggesting that OCA therapy or farnesoid X receptor agonism could be used to limit cholestasis-induced neuronal senescence.

TREM-2 plays a protective role in cholestasis by acting as a negative regulator of inflammation.

Inflammation, particularly that mediated by bacterial components translocating from the gut to the liver and binding to toll-like receptors (TLRs), is central to cholestatic liver injury. The triggering receptor expressed on myeloid cells-2 (TREM-2) inhibits TLR-mediated signaling and exerts a protective role in hepatocellular injury and carcinogenesis. This study aims to evaluate the role of TREM-2 in cholestasis. TREM-2 expression was analyzed in the livers of patients with primary biliary cholangitis (PBC) or primary sclerosing cholangitis (PSC), and in mouse models of cholestasis. Wild-type (WT) and Trem-2 deficient (Trem-2-/-) mice were subjected to experimental cholestasis and gut sterilization. Primary cultured Kupffer cells were incubated with lipopolysaccharide and/or ursodeoxycholic acid (UDCA) and inflammatory responses were analyzed. TREM-2 expression was upregulated in the livers of patients with PBC or PSC, and in murine models of cholestasis. Compared to WT, the response to bile duct ligation (BDL)-induced obstructive cholestasis or alpha-naphtylisothiocyanate (ANIT)-induced cholestasis was exacerbated in Trem-2-/- mice. This was characterized by enhanced necroptotic cell death, inflammatory responses and biliary expansion. Antibiotic treatment partially abrogated the effects observed in Trem-2-/- mice after BDL. Experimental overexpression of TREM-2 in the liver of WT mice downregulated ANIT-induced IL-33 expression and neutrophil recruitment. UDCA regulated Trem-1 and Trem-2 expression in primary cultured mouse Kupffer cells and dampened inflammatory gene transcription via a TREM-2-dependent mechanism. TREM-2 acts as a negative regulator of inflammation during cholestasis, representing a novel potential therapeutic target. Cholestasis (the reduction or cessation of bileflow) causes liver injury. This injury is exacerbated when gut-derived bacterial components interact with receptors (specifically Toll-like receptors or TLRs) on liver-resident immune cells, promoting inflammation. Herein, we show that the anti-inflammatory receptor TREM-2 dampens TLR-mediated signaling and hence protects against cholestasis-induced liver injury. Thus, TREM-2 could be a potential therapeutic target in cholestasis.

Fluorofenidone ameliorates cholestasis and fibrosis by inhibiting hepatic Erk/-Egr-1 signaling and Tgfβ1/Smad pathway in mice

Cholestasis is characterized by intrahepatic accumulation of bile acids (BAs), resulting in liver injury, fibrosis, and liver failure. To date, only ursodeoxycholic acid and obeticholic acid have been approved for the treatment of cholestasis. As fluorofenidone (AKF-PD) was previously reported to play significant anti-fibrotic and anti-inflammatory roles in various diseases, we investigated whether AKF-PD ameliorates cholestasis. A mouse model of cholestasis was constructed by administering a 0.1 % 3,5-diethoxycarbonyl-1,4-dihydroxychollidine (DDC) diet for 14 days. Male C57BL/6 J mice were treated with either AKF-PD or pirfenidone (PD) orally in addition to the DDC diet. Serum and liver tissues were subsequently collected and analyzed. We found that AKF-PD significantly reduced the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bile salts (TBA), as well as hepatic bile acids (BAs) levels. Hepatic histological analyses demonstrated that AKF-PD markedly attenuated hepatic inflammation and fibrosis. Further mechanistic analyses revealed that AKF-PD markedly inhibited expression of Cyp7a1, an enzyme key to BAs synthesis, by increasing Fxr nuclear translocation, and decreased hepatic inflammation by attenuating Erk/-Egr-1-mediated expression of inflammatory cytokines and chemokines Tnfα, Il-1β, Il-6, Ccl2, Ccl5 and Cxcl10. Moreover, AKF-PD was found to substantially reduce liver fibrosis via inhibition of Tgfβ1/Smad pathway in our mouse model. Here, we found that AKF-PD effectively attenuates cholestasis and hepatic fibrosis in the mouse model of DDC-induced cholestasis. As such, AKF-PD warrants further investigation as a candidate drug for treatment of cholestasis.

Synergetic Effect of Lupeol and Naringin Against Bile Duct Ligation Induced Cardiac Injury in Rats via Modulating Nitrite Level (eNos) and NF-kB /p65 Expression.

Cardiac dysfunction such as cirrhotic cardiomyopathy is more common in liver cirrhosis related disorders including primary biliary cholangitis or biliary cirrhosis and primary sclerosing cholangitis. Bile duct ligation (BDL) is an effective model of biliary cholestasis, producing oxidative damage and fibrosis. This research was designed to evaluate the effect of Lupeol and Naringin and its combination on bile duct ligation induced cardiac injury in rats. For pharmacological evaluation, rats were randomly divided into seven groups; intrahepatic cholestasis induced by ligation of the bile duct might lead to cirrhotic cardiomyopathy. The results were analyzed by physical, biochemical and histological examination. The Lupeol (100 mg/kg, p.o.), Naringin (100 mg/kg, p.o.) and its combination (100 mg/kg each) treated group significantly improved physical infarct size, biochemical (Nitrite, SOD, CAT, and GSH) and histological (heart tissue- mitochondrial function/integrity and fibrosis) alterations occurs due to BDL-ligation. This study was concluded that oral administration of Lupeol, Naringin, and its combination has a curative potential against BDL-induced cardiac injury in rats by reducing oxidative stress and inflammatory reactions, resulting in reduced heart necrosis/myocardial infarction and increased myocardial activity. It also inhibits cardiac damage in the rat heart, these effects may be linked to the NO level (eNOS) is increased and the inactivation of the NF-kB-p65 expression pathways.This study also provides new insights into the development of lupeol and Naringin combination that can be used as supportive therapy for cardiovascular diseases.