FXR agonists for MASH therapy: Lessons and perspectives from obeticholic acid.

Nonalcoholic fatty liver disease, also called metabolic dysfunction-associated steatotic liver disease, is the most common liver disease worldwide and has no approved pharmacotherapy. Due to its beneficial effects on metabolic regulation, inflammation suppression, cell death prevention, and fibrogenesis inhibition, farnesoid X receptor (FXR) is widely accepted as a promising therapeutic target for nonalcoholic steatosis (NASH) or called metabolic dysfunction-associated steatohepatitis (MASH). Many FXR agonists have been developed for NASH/MASH therapy. Obeticholic acid (OCA) is the pioneering frontrunner FXR agonist and the first demonstrating success in clinical trials. Unfortunately, OCA did not receive regulatory approval as a NASH pharmacotherapy because its moderate benefits did not outweigh its safety risks, which may cast a shadow over FXR-based drug development for NASH/MASH. This review summarizes the milestones in the development of OCA for NASH/MASH and discuss its limitations, including moderate hepatoprotection and the undesirable side effects of dyslipidemia, pruritus, cholelithiasis, and liver toxicity risk, in depth. More importantly, we provide perspectives on FXR-based therapy for NASH/MASH, hoping to support a successful bench-to-clinic transition.

Bile acid metabolomics identifies chenodeoxycholic acid as a therapeutic agent for pancreatic necrosis.

Bile acids are altered and associated with prognosis in patients with acute pancreatitis (AP). Here, we conduct targeted metabolomic analyses to detect bile acids changes in patients during the acute (n = 326) and the recovery (n = 133) phases of AP, as well as in healthy controls (n = 60). Chenodeoxycholic acid (CDCA) decreases in the acute phase, increases in the recovery phase, and is associated with pancreatic necrosis. CDCA and its derivative obeticholic acid exhibit a protective effect against acinar cell injury in vitro and pancreatic necrosis in murine models, and RNA sequencing reveals that the oxidative phosphorylation pathway is mainly involved. Moreover, we find that overexpression of farnesoid X receptor (FXR, CDCA receptor) inhibits pancreatic necrosis, and interfering expression of FXR exhibits an opposite phenotype in mice. Our results possibly suggest that targeting CDCA is a potential strategy for the treatment of acinar cell necrosis in AP, but further verification is needed.

Alterations in Circulating Bile Acids in Metabolic Dysfunction-Associated Steatotic Liver Disease: A Systematic Review and Meta-Analysis.

Background: Previous studies have suggested that bile acids (BAs) may participate in the development and/or progression of metabolic dysfunction-associated steatotic liver disease (MASLD). The present study aimed to define whether specific BA molecular species are selectively associated with MASLD development, disease severity, or geographic region. Methods: We comprehensively identified all eligible studies reporting circulating BAs in both MASLD patients and healthy controls through 30 July 2023. The pooled results were expressed as the standard mean difference (SMD) and 95% confidence interval (CI). Subgroup, sensitivity, and meta-regression analyses were performed to address heterogeneity. Results: Nineteen studies with 154,807 individuals were included. Meta-analysis results showed that total BA levels in MASLD patients were higher than those in healthy controls (SMD = 1.03, 95% CI: 0.63-1.42). When total BAs were divided into unconjugated and conjugated BAs or primary and secondary BAs, the pooled results were consistent with the overall estimates except for secondary BAs. Furthermore, we examined each individual BA and found that 9 of the 15 BAs were increased in MASLD patients, especially ursodeoxycholic acids (UDCA), taurococholic acid (TCA), chenodeoxycholic acids (CDCA), taurochenodeoxycholic acids (TCDCA), and glycocholic acids (GCA). Subgroup analysis revealed that different geographic regions or disease severities led to diverse BA profiles. Notably, TCA, taurodeoxycholic acid (TDCA), taurolithocholic acids (TLCA), and glycolithocholic acids (GLCA) showed a potential ability to differentiate metabolic dysfunction-associated steatohepatitis (MASH) (all p < 0.05). Conclusions: An altered profile of circulating BAs was shown in MASLD patients, providing potential targets for the diagnosis and treatment of MASLD.

Treatment of cerebrotendinous xanthomatosis in pregnancy: Patient and physician perspectives.

Cerebrotendinous xanthomatosis (CTX) is a rare, autosomal recessive disorder of bile acid synthesis that presents with varied and progressive symptomology. Early treatment with chenodeoxycholic acid (CDCA) improves symptoms and slows degeneration. Patients with CTX are commonly recommended to discontinue CDCA treatment during pregnancy because of theoretical risks to the fetus, but patient and clinician concerns about the risks of stopping treatment cause uncertainty. Herein, we report the experiences and perspectives of two women with CTX from the time of diagnosis through pregnancy, as well as decisions regarding CDCA treatment during pregnancy. Before becoming pregnant, both women were concerned about potential risks to their newborns if they continued or stopped CDCA treatment during pregnancy. Reassurance from their CTX specialist was the primary factor in their decision to continue treatment during pregnancy. After pregnancies complicated by preeclampsia, one gave birth to a healthy infant and the other gave birth to an infant later diagnosed with periventricular leukomalacia. Neither experienced CDCA-related complications.

Gut microbiome determines therapeutic effects of OCA on NAFLD by modulating bile acid metabolism.

Non-alcoholic fatty liver disease (NAFLD), the most common chronic liver disease, had no approved pharmacological agents yet. Obeticholic acid (OCA), a novel bile acid derivative, was demonstrated to ameliorate NAFLD-related manifestations. Regarding the role of gut-liver axis in liver disease development, this study aimed to explore the potential role of gut microbiota in the treatment of OCA in NAFLD mice induced by the high-fat diet (HFD). Antibiotic-induced microbiome depletion (AIMD) and fecal microbiota transplantation (FMT) confirmed the critical role of gut microbiota in OCA treatment for NAFLD by effectively alleviating histopathological lesions and restoring liver function impaired by HFD. Metagenomic analysis indicated that OCA intervention in HFD mice remarkably increased the abundance of Akkermansia muciniphila, Bifidobacterium spp., Bacteroides spp., Alistipes spp., Lactobacillus spp., Streptococcus thermophilus, and Parasutterella excrementihominis. Targeted metabolomics analysis indicated that OCA could modulate host bile acids pool by reducing levels of serum hydrophobic cholic acid (CA) and chenodeoxycholic acid (CDCA), and increasing levels of serum-conjugated bile acids, such as taurodeoxycholic acid (TDCA) and tauroursodesoxycholic acid (TUDCA) in the HFD-fed mice. Strong correlations were observed between differentially abundant microbes and the shifted bile acids. Furthermore, bacteria enriched by OCA intervention exhibited much greater potential in encoding 7alpha-hydroxysteroid dehydrogenase (7α-HSDs) producing secondary bile acids rather than bile salt hydrolases (BSHs) mainly responsible for primary bile acid deconjugation. In conclusion, this study demonstrated that OCA intervention altered gut microbiota composition with specially enriched gut microbes modulating host bile acids, thus effectively alleviating NAFLD in the mice.

Chenodeoxycholic acid rescues axonal degeneration in induced pluripotent stem cell-derived neurons from spastic paraplegia type 5 and cerebrotendinous xanthomatosis patients.

BACKGROUND: Biallelic mutations in CYP27A1 and CYP7B1, two critical genes regulating cholesterol and bile acid metabolism, cause cerebrotendinous xanthomatosis (CTX) and hereditary spastic paraplegia type 5 (SPG5), respectively. These rare diseases are characterized by progressive degeneration of corticospinal motor neuron axons, yet the underlying pathogenic mechanisms and strategies to mitigate axonal degeneration remain elusive. METHODS: To generate induced pluripotent stem cell (iPSC)-based models for CTX and SPG5, we reprogrammed patient skin fibroblasts into iPSCs by transducing fibroblast cells with episomal vectors containing pluripotency factors. These patient-specific iPSCs, as well as control iPSCs, were differentiated into cortical projection neurons (PNs) and examined for biochemical alterations and disease-related phenotypes. RESULTS: CTX and SPG5 patient iPSC-derived cortical PNs recapitulated several disease-specific biochemical changes and axonal defects of both diseases. Notably, the bile acid chenodeoxycholic acid (CDCA) effectively mitigated the biochemical alterations and rescued axonal degeneration in patient iPSC-derived neurons. To further examine underlying disease mechanisms, we developed CYP7B1 knockout human embryonic stem cell (hESC) lines using CRISPR-cas9-mediated gene editing and, following differentiation, examined hESC-derived cortical PNs. Knockout of CYP7B1 resulted in similar axonal vesiculation and degeneration in human cortical PN axons, confirming a cause-effect relationship between gene deficiency and axonal degeneration. Interestingly, CYP7B1 deficiency led to impaired neurofilament expression and organization as well as axonal degeneration, which could be rescued with CDCA, establishing a new disease mechanism and therapeutic target to mitigate axonal degeneration. CONCLUSIONS: Our data demonstrate disease-specific lipid disturbances and axonopathy mechanisms in human pluripotent stem cell-based neuronal models of CTX and SPG5 and identify CDCA, an established treatment of CTX, as a potential pharmacotherapy for SPG5. We propose this novel treatment strategy to rescue axonal degeneration in SPG5, a currently incurable condition.

The FXR mediated anti-depression effect of CDCA underpinned its therapeutic potentiation for MDD.

Emerging evidence from animal and human studies has suggested that small microbial metabolites generated in the gut influence host mood and behavior. Our previous study reported that patients with major depressive disorder (MDD) reduced the abundance of genera Blautia and Eubacterium, the microbials critically regulating cholesterol and bile acid metabolism in the gut. In this study, we further demonstrated that the levels of plasma bile acid chenodeoxycholic acid (CDCA) were significantly lower in Chinese MDD patients (142) than in healthy subjects (148). Such low levels of plasma CDCA in MDD patients were rescued in remitters but not in nonremitters following antidepressant treatment. In a parallel animal study, Chronic Social Defeat Stress (CSDS) depressed mice reduced the plasma CDCA and expression level in prefrontal cortex (PFC) of bile acid receptor (FXR) protein, which is a ligand-activated transcription factor and a member of the nuclear receptor superfamily. We found that CDCA treatment restored the level of FXR in the CSDS mice, suggesting the involvement of bile acid receptors in MDD. We observed that CDCA decreased the activity of the NLRP3 inflammasome and caspase-1 and subsequently increased the levels of phosphorylation and expression of PFC glutamate receptors (GluA1) in the PFC. In addition, CDCA showed antidepressant effects in the tests of sucrose preference, tail suspension, and forced swimming in CSDS mouse model of depression. Finally, in agreement with this idea, blocking these receptors by a FXR antagonist GS abolished CDCA-induced antidepressant effect. Moreover, CDCA treatment rescued the increase of IL-1ß, IL-6, TNF α and IL-17, which also were blocked by GS. These results suggest that CDCA is a biomarker and target potentially important for the diagnosis and treatment of MDD.

Microbiota-induced lipid peroxidation impairs obeticholic acid-mediated antifibrotic effect towards nonalcoholic steatohepatitis in mice.

Obeticholic acid (OCA) has been examined to treat non-alcoholic steatohepatitis (NASH), but has unsatisfactory antifibrotic effect and deficient responsive rate in recent phase III clinical trial. Using a prolonged western diet-feeding murine NASH model, we show that OCA-shaped gut microbiota induces lipid peroxidation and impairs its anti-fibrotic effect. Mechanically, Bacteroides enriched by OCA deconjugates tauro-conjugated bile acids to generate excessive chenodeoxycholic acid (CDCA), resulting in liver ROS accumulation. We further elucidate that OCA reduces triglycerides containing polyunsaturated fatty acid (PUFA-TGs) levels, whereas elevates free PUFAs and phosphatidylethanolamines containing PUFA (PUFA-PEs), which are susceptible to be oxidized to lipid peroxides (notably arachidonic acid (ARA)-derived 12-HHTrE), inducing hepatocyte ferroptosis and activating hepatic stellate cells (HSCs). Inhibiting lipid peroxidation with pentoxifylline (PTX) rescues anti-fibrotic effect of OCA, suggesting combination of OCA and lipid peroxidation inhibitor could be a potential antifibrotic pharmacological approach in clinical NASH-fibrosis.

Obeticholic acid treatment ameliorates the cardiac dysfunction in NASH mice.

BACKGROUND: Suppression of cardiac iinflammasome, which can be inhibited by Farnesoid X receptor (FXR) agonist, can ameliorate cardiac inflammation and fibrosis. Increased cardiac inflammasome decrease the abundance of regulatory T (Treg) cells and exacerbate cardiac dysfunction. Interaction between cardiomyocytes and Treg cells is involved in the development of nonalcoholic steatohepatitis (NASH)-related cardiac dysfunction. AIMS: This study evaluates whether the FXR agonist obeticholic acid (OCA) treatment improves NASH-associated cardiac dysfunction. METHODS: The in vivo and in vitro mechanisms and effects of two weeks of OCA treatment on inflammasome and Treg dysregulation-related cardiac dysfunction in NASH mice (NASH-OCA) at systemic, tissue and cellular levels were investigated. RESULTS: The OCA treatment suppressed the serum and cardiac inflammasome levels, reduced the cardiac infiltrated CD3+ T cells, increased the cardiac Treg-represented anti-inflammatory cytokines (IL-10/IL-10R) and improved cardiac inflammation, fibrosis and function [decreased left ventricle (LV) mass and increased fractional shortening (FS)] in NASH-OCA mice. The percentages of OCA-decreased cardiac fibrosis and OCA-increased FS were positively correlated with the percentage of OCA-increased levels of cardiac FXR and IL-10/IL-10R. In the Treg cells from NASH-OCA mice spleen, in comparison with the Treg cells of the NASH group, higher intracellular FXR but lower inflammasome levels, and more proliferative/active and less apoptotic cells were observed. Incubation of H9c2 cardiomyoblasts with Treg-NASHcm [supernatant of Treg from NASH mice as condition medium (cm)], increased inflammasome levels, decreased the proliferative/active cells, suppressed the intracellular FXR, and downregulated differentiation/contraction marker. The Treg-NASHcm-induced hypocontractility of H9c2 can be attenuated by co-incubation with OCA, and the OCA-related effects were abolished by siIL-10R pretreatment. CONCLUSIONS: Chronic FXR activation with OCA is a potential strategy for activating IL-10/IL-10R signalling, reversing cardiac regulatory T cell dysfunction, and improving inflammasome-mediated NASH-related cardiac dysfunction.

Novel Therapies in Primary Biliary Cholangitis: What Is in the Pipeline?

Primary biliary cholangitis is a chronic autoimmune disease characterized by inflammation and the progressive destruction of small intrahepatic bile ducts. Current first-line treatment includes ursodeoxycholic acid; however, a significant number of patients have an inadequate response to therapy. These patients are at risk of liver failure requiring liver transplantation and experience a poor quality of life due to refractory symptoms. This manuscript aims to shed light on the current and prospective treatment options that may slow disease progression and improve these patients' symptoms.

Long-term MRI Findings in Patients With Cerebrotendinous Xanthomatosis Treated With Chenodeoxycholic Acid.

OBJECTIVES: To describe long-term follow-up brain MRI findings in patients with cerebrotendinous xanthomatosis (CTX) treated with chenodeoxycholic acid (CDCA). METHODS: Of a cohort of 79 Dutch patients with CTX, we retrospectively reviewed brain MRI findings of patients at diagnosis (before the start of treatment) and after long-term follow-up (7-27 years) in 12 patients. In addition, we report on 2 families with remarkable brain MRI findings. RESULTS: MRI abnormalities showed progression in all 7 patients diagnosed at 24 years or older and only in 1 of 5 patients diagnosed younger than 24 years. MRI findings in the other patients diagnosed younger than 24 years were normal at baseline and remained normal even after follow-up of more than 25 years. The total MRI scores at baseline were 2 and 19 and at follow-up 4 and 37, respectively, for patients diagnosed before or after the age of 24 years, despite a comparable number of treatment years. DISCUSSION: MRI findings are fully in line with our long-term treatment effect article, emphasizing the importance of early diagnosis and treatment in CTX. Expanding the spectrum of brain MRI findings (including the finding of a posterior leukoencephalopathy) leads to a better understanding of the heterogeneity of this treatable disease.

Differing clinical features between Japanese siblings with cerebrotendinous xanthomatosis with a novel compound heterozygous CYP27A1 mutation: a case report.

BACKGROUND: Cerebrotendinous xanthomatosis (CTX) is an autosomal-recessive lipid storage disorder caused by mutations in the CYP27A1 gene encoding the key enzyme in the bile acid synthesis, sterol 27-hydroxylase. Here, we report two Japanese CTX siblings with a novel compound heterozygous CYP27A1 mutation, showing different clinical phenotypes and responses to chenodeoxycholic acid (CDCA) therapy. CASE PRESENTATION: The proband, a 32-year-old man, who had chronic diarrhea, bilateral cataracts, and xanthomas, demonstrated progressive neurological manifestations including ataxia, and spastic paraplegia during a 5-year follow-up period despite normalization of serum cholestanol after initiation of CDCA treatment. He also exhibited cognitive decline although improvement had been observed at the beginning of treatment. Follow-up brain magnetic resonance imaging (MRI) revealed pronounced progressive atrophy in the cerebellum, in addition to expanding hyperintense lesions in the dentate nuclei, posterior limb of the internal capsule, cerebral peduncles, and inferior olives on T2-weighted images. In contrast, the two-year-younger sister of the proband presented with chronic diarrhea, cataracts, xanthomas, and intellectual disability but no other neurological symptoms at the time of diagnosis. CDCA treatment lead to improvement of cognitive function and there were no characteristic CTX-related MRI features during the follow-up period. The siblings shared a paternally inherited c.1420C > T mutation (p.Arg474Trp) and a maternally inherited novel c.1176_1177delGA mutation, predicting p.(Glu392Asp*20). CONCLUSIONS: Our cases suggest that early diagnosis and subsequent initiation of CDCA treatment are crucial before the appearance of characteristic MRI findings and severe neurological manifestations related to CTX. Further studies are required to elucidate mechanisms responsible for the clinical diversity of CTX and prognostic factors for long-term outcomes following initiation of CDCA treatment.

Chenodeoxycholic acid inhibits lung adenocarcinoma progression via the integrin α5ß1/FAK/p53 signaling pathway.

BACKGROUND: Lung cancer is the leading cause of cancer-associated death worldwide and is classified into non-small cell lung cancer (NSCLC) and small-cell lung cancer (SCLC). NSCLC accounts for approximately 80%-85% of all lung cancer cases. Chenodeoxycholic acid (CDCA), a primary bile acid, has been reported to inhibit carcinoma cell proliferation. Here, we aimed to determine the effects and mechanism of action of CDCA against lung adenocarcinoma (LUAD). METHODS: Western blotting and quantitative real-time polymerase chain reaction were used to evaluate the protein and mRNA expression levels in LUAD cell lines, respectively. Cell Counting Kit-8 and clone formation assays were performed to evaluate the proliferation ability of different cell types in vitro. Tumor cell motility was evaluated using Transwell assays. The transcriptional profile of A549 cells treated with CDCA was determined through RNA sequencing analysis. A xenograft model was established to evaluate the effects of CDCA on LUAD progression in vivo. RESULTS: CDCA inhibited LUAD cell proliferation, migration, and invasion. Furthermore, it promoted apoptosis in LUAD cells. Mechanistically, CDCA inhibited the integrin α5ß1 signaling pathway in LUAD cells by inhibiting the expression of the α5 and ß1 subunits of integrin and phosphorylated FAK. Moreover, CDCA induced an increase in the levels of p53, a downstream gene of the integrin α5ß1/FAK pathway. In addition, CDCA significantly decreased tumor volume in mice without inducing significant toxicity. CONCLUSIONS: Our findings indicate that CDCA attenuates LUAD pathogenesis in vitro and in vivo via the integrin α5ß1/FAK/p53 axis.

Patents vs patients 1-0: The case of chenodeoxycholic acid.

Profit-driven games with the availability and prices of chenodeoxycholic acid led to the discontinuation of proper treatment for this cerebrotendinous xanthomatosis patient with disastrous consequences to his health.

Using fiber tractography and diffusion kurtosis imaging to evaluate neuroimaging changes in patients with cerebrotendinous xanthomatosis after stopping chenodeoxycholic acid treatment for three years.

BACKGROUND: The aim of this study was to use tractography and diffusion kurtosis imaging (DKI) to evaluate cerebral white matter (WM) changes in patients with cerebrotendinous xanthomatosis (CTX) after stopping chenodeoxycholic acid (CDCA) treatment. METHODS: Two siblings with CTX aged 40 and 38 years, respectively, who had been diagnosed with CTX for 16 years were enrolled. They had received CDCA treatment from 2005 until 2015, after which CDCA was no longer available in Taiwan. Serial brain magnetic resonance imaging (MRI) studies were used to record brain changes, and a seres of neuropsychiatric tests were used to evaluate cognitive changes 3 years after stopping CDCA treatment. RESULTS: The conventional MRI studies revealed progressive changes in dentate nuclei and surrounding cerebellar hemispheres, but no obvious changes in cerebral white matter (WM). Tractography captured in 2018 showed a general reduction in fiber density, especially involving frontal lobe fibers, compared to 2015. In addition, the DKI studies performed in 2018 showed a decreased axonal water fraction in diffuse WM structures and increased RadEAD in frontal WM. Comparisons of the neuropsychiatric test results between 2015 and 2018 showed a marked decline in executive function including design fluency, digit backward span and digit forward span, and this cognitive impairment highly suggested frontal lobe dysfunction. CONCLUSIONS: This study may suggest that cerebral tractography and DKI study results can identify changes in cerebral WM in CTX patients shortly after stopping CDCA treatment, and that they may have a better correlation with the results of neuropsychiatric tests.

Cerebrotendinous xanthomatosis with radiological abnormalities of the chest.

A 55-year-old man with mental retardation and calcaneal tendon thickening was referred for a suspected genetic disease. His serum cholestanol was elevated and genetic analysis of his blood cells for CYP27A1 revealed a homozygous missense mutation. We diagnosed him with cerebrotendinous xanthomatosis (CTX). Chest radiography revealed diffuse micronodular and reticular opacities. Histological findings obtained from the transbronchial lung biopsy revealed foamy macrophages and multinucleate giant cells with marked lipid crystal clefts. Although there are few reports of pulmonary lesions in CTX, we concluded from the radiological and histopathological findings that the pulmonary lesions were indeed caused by the CTX. The patient was treated with chenodeoxycholic acid. His neurological findings and calcaneal tendon thickening were unchanged; however, his serum cholestanol and radiological abnormalities of the chest decreased.

Obeticholic Acid and Fibrates in Primary Biliary Cholangitis: Comparative Effects in a Multicentric Observational Study.

INTRODUCTION: Obeticholic acid (OCA) and fibrates therapy results in biochemical improvement in placebo-controlled trials in patients with primary biliary cholangitis and insufficient response to ursodeoxycholic acid. There is scarce information outside of clinical trials. Therefore, we have assessed the effectiveness and adverse events of these treatments. METHODS: Data from patients included in the ColHai registry treated with OCA, fibrates, or both were recorded during a year, as well as adverse events and treatment discontinuation. RESULTS: Eighty-six patients were treated with OCA, 250 with fibrates (81% bezafibrate; 19% fenofibrate), and 15 with OCA plus fibrates. OCA group had baseline significantly higher alkaline phosphatase (ALP) (P = 0.01) and lower platelets (P = 0.03) than fibrates. Both treatments significantly decreased ALP, gamma-glutamyl transferase (GGT), and transaminases and improved Globe score. Albumin and immunoglobulin type M improved in the fibrates group. ALP decrease was higher under fibrates, whereas alanine aminotransferase decline was higher under OCA. Although baseline transaminases and GGT were higher in patients with OCA plus fibrates, significant ALP, GGT, alanine aminotransferase, and Globe score improvement were observed during triple therapy. Adverse events were reported in 14.7% of patients (21.3% OCA; 17.6% fenofibrate; 10.7% bezafibrate), mainly pruritus (10.1% with OCA). Discontinuation was more frequent in fenofibrate treatment mainly because of intolerance or adverse events. DISCUSSION: Second-line therapy with OCA or fibrates improves hepatic biochemistry and the GLOBE score in primary biliary cholangitis patients with suboptimal response to ursodeoxycholic acid. Simultaneous treatment with OCA and fibrates improved ALP as well.