Anti-fibrotic effects of chronic treatment with the selective FXR agonist obeticholic acid in the bleomycin-induced rat model of pulmonary fibrosis

Farnesoid X receptor (FXR) activation by obeticholic acid (OCA) has been demonstrated to inhibit inflammation and fibrosis development in liver, kidney and intestine in multiple disease models. FXR activation has also been demonstrated to suppress the inflammatory response and to promote lung repair after lung injury. This study investigated the protective effects of OCA treatment (3 or 10mg/kg/day) on inflammation, tissue remodeling and fibrosis in the bleomycin-induced pulmonary fibrosis rat model. Effects of OCA treatment on morphological and molecular alterations of the lung, as well as remodeling of the alveoli and the right ventricle were also evaluated. Lung function was assessed by measuring airway resistance to inflation. In the acute phase (7days), bleomycin promoted an initial thickening and fibrosis of the lung interstitium, with upregulation of genes related to epithelial proliferation, tissue remodeling and hypoxia. At 28days, an evident increase in the deposition of collagen in the lungs was observed. This excessive deposition was accompanied by an upregulation of transcripts related to the extracellular matrix (TGFβ1, SNAI1 and SNAI2), indicating lung fibrosis. Administration of OCA protected against bleomycin-induced lung damage by suppressing molecular mechanisms related to epithelial-to-mesenchymal transition (EMT), inflammation and collagen deposition, with a dose-dependent reduction of proinflammatory cytokines such as IL-1β and IL-6, as well as TGF-β1 and SNAI1 expression. Pirfenidone, a recently approved treatment for idiopathic pulmonary fibrosis (IPF), significantly counteracted bleomycin-induced pro-fibrotic genes expression, but did not exert significant effects on IL-1β and IL-6. OCA treatment in bleomycin-challenged rats also improved pulmonary function, by effectively normalizing airway resistance to inflation and lung stiffness in vivo. Results with OCA were similar, or even superior, to those obtained with pirfenidone. In conclusion, our results suggest an important protective effect of OCA against bleomycin-induced lung fibrosis by blunting critical mediators in the pathogenesis of IPF.

Pharmacological interventions for primary biliary cholangitis: an attempted network meta-analysis

BACKGROUND

Primary biliary cholangitis (previously primary biliary cirrhosis) is a chronic liver disease caused by the destruction of small intra-hepatic bile ducts resulting in stasis of bile (cholestasis), liver fibrosis, and liver cirrhosis. The optimal pharmacological treatment of primary biliary cholangitis remains uncertain.

OBJECTIVES

To assess the comparative benefits and harms of different pharmacological interventions in the treatment of primary biliary cholangitis through a network meta-analysis and to generate rankings of the available pharmacological interventions according to their safety and efficacy. However, it was not possible to assess whether the potential effect modifiers were similar across different comparisons. Therefore, we did not perform the network meta-analysis, and instead, assessed the comparative benefits and harms of different interventions using standard Cochrane methodology.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 2), MEDLINE, Embase, Science Citation Index Expanded, World Health Organization International Clinical Trials Registry Platform, and randomised controlled trials registers to February 2017 to identify randomised clinical trials on pharmacological interventions for primary biliary cholangitis.

SELECTION CRITERIA

We included only randomised clinical trials (irrespective of language, blinding, or publication status) in participants with primary biliary cholangitis. We excluded trials which included participants who had previously undergone liver transplantation. We considered any of the various pharmacological interventions compared with each other or with placebo or no intervention.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We calculated the odds ratio (OR) and rate ratio with 95% confidence intervals (CI) using both fixed-effect and random-effects models based on available-participant analysis with Review Manager 5. We assessed risk of bias according to Cochrane, controlled risk of random errors with Trial Sequential Analysis, and assessed the quality of the evidence using GRADE.

MAIN RESULTS

We identified 74 trials including 5902 participants that met the inclusion criteria of this review. A total of 46 trials (4274 participants) provided information for one or more outcomes. All the trials were at high risk of bias in one or more domains. Overall, all the evidence was low or very low quality. The proportion of participants with symptoms varied from 19.9% to 100% in the trials that reported this information. The proportion of participants who were antimitochondrial antibody (AMA) positive ranged from 80.8% to 100% in the trials that reported this information. It appeared that most trials included participants who had not received previous treatments or included participants regardless of the previous treatments received. The follow-up in the trials ranged from 1 to 96 months.The proportion of people with mortality (maximal follow-up) was higher in the methotrexate group versus the no intervention group (OR 8.83, 95% CI 1.01 to 76.96; 60 participants; 1 trial; low quality evidence). The proportion of people with mortality (maximal follow-up) was lower in the azathioprine group versus the no intervention group (OR 0.56, 95% CI 0.32 to 0.98; 224 participants; 2 trials; I² = 0%; low quality evidence). However, it has to be noted that a large proportion of participants (25%) was excluded from the trial that contributed most participants to this analysis and the results were not reliable. There was no evidence of a difference in any of the remaining comparisons. The proportion of people with serious adverse events was higher in the D-penicillamine versus no intervention group (OR 28.77, 95% CI 1.57 to 526.67; 52 participants; 1 trial; low quality evidence). The proportion of people with serious adverse events was higher in the obeticholic acid plus ursodeoxycholic acid (UDCA) group versus the UDCA group (OR 3.58, 95% CI 1.02 to 12.51; 216 participants; 1 trial; low quality evidence). There was no evidence of a difference in any of the remaining comparisons for serious adverse events (proportion) or serious adverse events (number of events). None of the trials reported health-related quality of life at any time point.

FUNDING

nine trials had no special funding or were funded by hospital or charities; 31 trials were funded by pharmaceutical companies; and 34 trials provided no information on source of funding.

AUTHORS' CONCLUSIONS

Based on very low quality evidence, there is currently no evidence that any intervention is beneficial for primary biliary cholangitis. However, the follow-up periods in the trials were short and there is significant uncertainty in this issue. Further well-designed randomised clinical trials are necessary. Future randomised clinical trials ought to be adequately powered; performed in people who are generally seen in the clinic rather than in highly selected participants; employ blinding; avoid post-randomisation dropouts or planned cross-overs; should have sufficient follow-up period (e.g. five or 10 years or more); and use clinically important outcomes such as mortality, health-related quality of life, cirrhosis, decompensated cirrhosis, and liver transplantation. Alternatively, very large groups of participants should be randomised to facilitate shorter trial duration.

Emerging role of obeticholic acid in the management of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is the commonest chronic liver disease and its prevalence is increasing driven by the pandemic of obesity and type 2 diabetes mellitus. NAFLD can progress to cirrhosis and is associated with increased risk for cardiovascular disease and hepatocellular cancer. Diet and exercise are limited by suboptimal long-term adherence in patients with NAFLD. On the other hand, current pharmacological treatment of NAFLD has limited efficacy and unfavorable safety profile. In this context, obeticholic acid (OCA), a selective agonist of the farnesoid X receptors, might represent a useful option in these patients. Preclinical studies suggest that OCA improves hepatic steatosis, inflammation and fibrosis. A proof-of-concept study and the randomized, placebo-controlled Farnesoid X Receptor Ligand Obeticholic Acid in non-alcoholic steatohepatitis Treatment (FLINT) trial also showed improvements in liver histology in patients with NAFLD who received OCA. Weight loss and reduction in blood pressure were also observed. However, the effects of OCA on insulin resistance are conflicting and the lipid profile is adversely affected by this agent. In addition, pruritus is frequently observed during treatment with OCA and might lead to treatment discontinuation. However, given the limitations of existing treatments for NAFLD, OCA might represent a useful therapeutic option in selected patients with NAFLD.

Primary Biliary Cholangitis: Medical and Specialty Pharmacy Management Update

BACKGROUND

Chronic liver disease and cirrhosis are a leading cause of morbidity and mortality in the United States. Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis and which has been designated an orphan condition, is a chronic autoimmune disease resulting in the destruction of the small bile ducts in the liver. Without effective treatment, disease progression frequently leads to liver failure and death. Until May 2016, the only FDA-approved treatment for PBC was ursodiol (UDCA), an oral hydrophilic bile acid, which can slow progression of liver damage due to PBC. However, 1 out of 3 patients taking UDCA has an inadequate biochemical response, leading to increased risk of disease progression, liver transplantation, and mortality. Given this unmet clinical need, new therapies are in development for the treatment of PBC. To provide pharmacists with an overview of the latest research on the pathophysiology of PBC and potential new treatment options and to highlight medical and specialty pharmacy approaches to managing access to drugs to treat orphan diseases such as PBC, a 2-hour satellite symposium was presented in conjunction with the 2015 Academy of Managed Care Pharmacy (AMCP) Nexus meeting. Although obeticholic acid was approved by the FDA for the treatment of PBC in May 2016, this development occurred after the symposium presentation. The symposium was supported by an independent educational grant from Intercept Pharmaceuticals and was managed by Analysis Group. Robert Navarro, PharmD, moderated the CPE-accredited symposium titled "Medical and Specialty Pharmacy Management Update on Primary Biliary Cirrhosis." Expert panelists included Christopher L. Bowlus, MD; James T. Kenney, RPh, MBA; and Gary Rice, RPh, MS, MBA, CSP.

OBJECTIVE

To summarize the educational satellite symposium presentations and discussions.

SUMMARY

Autoimmune liver diseases, including PBC, are responsible for 15% of all liver transplants performed and an equal percentage of deaths related to liver disease. UDCA is the only FDA-approved therapy for treatment of PBC and is considered the standard of care. Nevertheless, many patients do not respond to UDCA, creating the need for new therapeutic options to improve clinical outcomes for PBC patients with inadequate response to treatment. While several agents are being studied in combination with UDCA, monotherapy with the novel agent obeticholic acid, a farnesoid X receptor agonist, has also shown promising results. Health plans are anticipated to assign any newly introduced therapy for the treatment of PBC to specialty pharmacy given its orphan disease status. This assignment enables the health plan to receive disease education, which is particularly important when new drugs are indicated for orphan diseases, and assistance with designing appropriate prior authorization criteria. The clinical value of any new therapeutic options that will inform formulary decisions and prior authorization criteria will be assessed based on evidence of efficacy, safety, and tolerability, among other factors, such as the potential to reduce or delay medical resource utilization (e.g., liver transplant). Key considerations for prior authorization of a new therapy will be determining which PBC patients are appropriate candidates for the new therapy and developing criteria for that determination. These are likely to include clinical diagnostic criteria and degree of response to prior treatment with UDCA. Initially, any new therapy would likely be positioned as noncovered until appropriate prior authorization criteria are established.

CONCLUSIONS

PBC is a chronic liver disease with significant morbidity and mortality, as well as a significant burden on the health care system if the disease progresses to the point at which a liver transplant is needed. Although UDCA, the current standard of care, has improved outcomes for many patients, others have an inadequate response to this treatment. This symposium discussed these issues and also addressed the overall treatment paradigm for orphan drug therapies, key implications for patient management, and the role of specialty pharmacy management and any associated needs both in general and specifically for new therapeutic options for PBC.

A Placebo-Controlled Trial of Obeticholic Acid in Primary Biliary Cholangitis

BACKGROUND

Primary biliary cholangitis (formerly called primary biliary cirrhosis) can progress to cirrhosis and death despite ursodiol therapy. Alkaline phosphatase and bilirubin levels correlate with the risk of liver transplantation or death. Obeticholic acid, a farnesoid X receptor agonist, has shown potential benefit in patients with this disease.

METHODS

In this 12-month, double-blind, placebo-controlled, phase 3 trial, we randomly assigned 217 patients who had an inadequate response to ursodiol or who found the side effects of ursodiol unacceptable to receive obeticholic acid at a dose of 10 mg (the 10-mg group), obeticholic acid at a dose of 5 mg with adjustment to 10 mg if applicable (the 5-10-mg group), or placebo. The primary end point was an alkaline phosphatase level of less than 1.67 times the upper limit of the normal range, with a reduction of at least 15% from baseline, and a normal total bilirubin level.

RESULTS

Of 216 patients who underwent randomization and received at least one dose of obeticholic acid or placebo, 93% received ursodiol as background therapy. The primary end point occurred in more patients in the 5-10-mg group (46%) and the 10-mg group (47%) than in the placebo group (10%; P<0.001 for both comparisons). Patients in the 5-10-mg group and those in the 10-mg group had greater decreases than those in the placebo group in the alkaline phosphatase level (least-squares mean, -113 and -130 U per liter, respectively, vs. -14 U per liter; P<0.001 for both comparisons) and total bilirubin level (-0.02 and -0.05 mg per deciliter [-0.3 and -0.9 μmol per liter], respectively, vs. 0.12 mg per deciliter [2.0 μmol per liter]; P<0.001 for both comparisons). Changes in noninvasive measures of liver fibrosis did not differ significantly between either treatment group and the placebo group at 12 months. Pruritus was more common with obeticholic acid than with placebo (56% of patients in the 5-10-mg group and 68% of those in the 10-mg group vs. 38% in the placebo group). The rate of serious adverse events was 16% in the 5-10-mg group, 11% in the 10-mg group, and 4% in the placebo group.

CONCLUSIONS

Obeticholic acid administered with ursodiol or as monotherapy for 12 months in patients with primary biliary cholangitis resulted in decreases from baseline in alkaline phosphatase and total bilirubin levels that differed significantly from the changes observed with placebo. There were more serious adverse events with obeticholic acid. (Funded by Intercept Pharmaceuticals; POISE ClinicalTrials.gov number, NCT01473524; Current Controlled Trials number, ISRCTN89514817.).

Comparative efficacy of interventions on nonalcoholic fatty liver disease (NAFLD): A PRISMA-compliant systematic review and network meta-analysis

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NAFLD) has significantly increased over the last decades. Despite existence of several interventions, there remains unclear which interventions work the best.

METHODS

A systematic review and network meta-analysis of randomized trials comparing efficacy of all treatment options in NAFLD were performed to determine comparative efficacy and safety of interventions in the management of NAFLD. Several electronic databases were searched up to Nov 15, 2015. Outcomes include liver histological outcomes (i.e., fibrosis), all-cause mortality, cirrhosis, and safety. A network meta-analysis was applied to estimate pooled risk ratios (RR). Quality of evidence was assessed using GRADE criteria.

RESULTS

A total of 44 studies (n = 3802) were eligible. When compared with placebo, obeticholic acid (OCA) was the only intervention that significantly improved fibrosis with RR (95% CI) of 1.91 (1.15, 3.16), while pentoxyfylline (PTX) demonstrated improved fibrosis without statistical significance with RR (95% CI) of 2.27 (0.81, 6.36). Only thiazolidinedione (TZD) and vitamin E use resulted in significant increase in resolution of NASH, while OCA, TZD, and vitamin E significantly improved other outcomes including NAS, steatosis, ballooning, and inflammation outcomes. Quality of evidence varied from very low (i.e., metformin, PTX on mean change of ballooning grade) to high (OCA, TZD, vitamin E on improving histological outcomes). Limitations of this study were lack of relevant long-term outcomes (e.g., cirrhosis, death, safety), possible small study effect, and few head-to-head studies.

CONCLUSIONS

Our study suggests potential efficacy of OCA, TZD, and vitamin E in improving histologic endpoints in NAFLD. These findings are however based on a small number of studies. Additional studies are awaited to strengthen this network meta-analysis.

Emerging Therapies for Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease is the most common cause of liver disease in the United States. There are no drug therapies approved for the treatment of nonalcoholic steatohepatitis (NASH). Multiple different pathways are involved in the pathogenesis and each can be the target of the therapy. It is possible that more than 1 target is involved in disease development and progression. Multiple clinical trials with promising agents are underway. Because NASH is a slowly progressive disease and treatment likely to be of prolonged duration, acceptance and approval of any agent will require information on long-term clinical benefits and safety.

Chenodeoxycholic acid reduces feed intake and modulates the expression of hypothalamic neuropeptides and hepatic lipogenic genes in broiler chickens

Bile acids have recently become an emerging research hot spot in mammals due to their roles as metabolic regulators and molecular signatures controlling whole-body metabolic homeostasis. Such effects are still unknown in avian (non-mammalian) species. We, therefore, undertook this study to determine the effect of chenodeoxycholic acid (CDCA) on growth performance and on the expression of hypothalamic neuropeptides and hepatic lipogenic genes in broiler chickens. Chickens fed with diet-containing 0.1% or 0.5% CDCA for two weeks exhibited a significant and a dose dependent reduction of feed intake and body weight compared to the control (standard diet). These changes were accompanied with a significant decrease in plasma glucose levels at d10 and d15 post-treatment. At molecular levels, CDCA treatment significantly up-regulated the expression of feeding-related hypothalamic neuropeptides (NPY, AgRP, ORX, CRH, Ghrl, and MC1R) and down-regulated the hypothalamic expression of SOCS3. CDCA treatment also decreased the mRNA levels of key hepatic lipogenic genes (FAS, ACCα, ME, ATPcl, and SCD-1) and their related transcription factors SREBP-1/2 and PPARα. In addition, CDCA reduced the hepatic expression of FXR and the adipokine, visfatin, and adiponectin genes compared to the control. Together, our data provide evidence that CDCA alters growth performances in broilers and modulates the expression of hypothalamic neuropeptides and hepatic lipogenic and adipocytokine genes.

Evaluation of cholesterol metabolism in cerebrotendinous xanthomatosis

BACKGROUND

Cerebrotendinous xanthomatosis (CTX) is a treatable bile acid disorder caused by mutations of CYP27A1. The pathogenesis of neurological damage has not been completely explained. Oral chenodeoxycholic acid (CDCA) can lead to clinical stabilization, but in a subgroup of patients the disease progresses despite treatment. In the present study, we aimed at clarifying cholesterol metabolism abnormalities and their response to CDCA treatment, in order to identify reliable diagnostic and prognostic markers and understand if differences exist between stable patients and those with neurological progression.

METHODS

We enrolled 19 untreated CTX patients and assessed serum profile of bile acids intermediates, oxysterols, cholesterol, lathosterol, and plant sterols. Then we performed a long-term follow up during CDCA therapy, and compared biochemical data with neurological outcome.

RESULTS

We observed increase of cholestanol, 7α-hydroxy-4-cholesten-3-one (7αC4), lathosterol, and plant sterols, whereas 27-hydroxycholesterol (27-OHC) was extremely low or absent. CDCA treatment at a daily dose of 750 mg normalized all biochemical parameters except for 7αC4 which persisted slightly higher than normal in most patients, and 27-OHC which was not modified by therapy. Biochemical evaluation did not reveal significant differences between stable and worsening patients.

DISCUSSION

Cholestanol and 7αC4 represent important markers for CTX diagnosis and monitoring of therapy. Treatment with CDCA should aim at normalizing serum 7αC4 as well as cholestanol, since 7αC4 better mirrors 7α-hydroxylation rate and is thought to be correlated with cholestanol accumulation in the brain. Assessment of serum 27-OHC is a very good tool for biochemical diagnosis at any stage of disease. Lathosterol and plant sterols should be considered as additional markers for diagnosis and monitoring of therapy. Further studies including long-term assessment of bile acid intermediates in cerebrospinal fluid are needed in patients who show clinical progression despite treatment.

Therapy of Primary Biliary Cirrhosis: Novel Approaches for Patients with Suboptimal Response to Ursodeoxycholic Acid

Primary biliary cirrhosis (PBC) is a chronic cholestatic disease of presumed autoimmune pathogenesis, characterized by the inflammation and damage of the intrahepatic intermediate and small bile ducts, which eventually results in cirrhosis. A number of randomized and observational and pilot studies using several agents were carried out in the 80s, but no clear results or even harmful effects were reported. Over the past 2 decades, increasing evidence indicates that ursodeoxycholic acid (UDCA) - 13 to 16 mg/kg/day--is the treatment of choice for patients with PBC. Biochemical response to UDCA, assessed at 1 year, clearly predicts the long-term outcome, since in UDCA, responders survival is similar to that estimated for the matched control population. However, about 40% of patients have incomplete biochemical response and increased risk of progression and decreased survival free of transplantation. Patients with suboptimal biochemical response to UDCA outline the group in whom further single or combined treatments with UDCA are needed. Accordingly, data on the effect of fibrates alone or in combination with UDCA, and budesonide in combination with UDCA have been reported. The combined treatment of UDCA and fibrates in patients without optimal biochemical response to UDCA improves the degree of cholestasis and may minimize the long-term management of these patients. The results of the combined therapy of UDCA with budesonide are appealing but they should be established in large randomized trials. The effect of new agents such obeticholic acid are promising, since the addition of this farnesoide-X-receptor agonist bile acid in patients with stable UDCA dosage and increased alkaline phosphatase levels results in an improvement of cholestasis as compared to placebo, with a parallel decrease of aminotransferases and immunoglobulin M, as well as one surrogate marker of bile acid synthesis. New molecular therapies are currently being investigated.

Comparison on Response and Dissolution Rates Between Ursodeoxycholic Acid Alone or in Combination With Chenodeoxycholic Acid for Gallstone Dissolution According to Stone Density on CT Scan: Strobe Compliant Observation Study

Medical dissolution of gallstone is usually performed on radiolucent gallstones in a functioning gallbladder. However, absence of visible gallstone on plain abdominal x-ray does not always preclude calcification. This study aims to compare the response and dissolution rates between ursodeoxycholic acid (UDCA) alone or in combination with chenodeoxycholic acid (CDCA) according to stone density on computed tomography (CT) scan. A total of 126 patients underwent dissolution therapy with either UDCA alone or combination of CDCA and UDCA (CNU) from December 2010 to March 2014 at Korea University Ansan Hospital. In the end, 81 patients (CNU group = 44, UDCA group = 37) completed dissolution therapy for 6 months. Dissolution rate (percentage reduction in the gallstone volume) and response to therapy (complete dissolution or partial dissolution defined as reduction in stone volume of >50%) were compared between the 2 groups. Dissolution and response rates of sludge was also compared between the 2 groups. The overall response rate was 50.6% (CNU group 43.2% vs UDCA group 59.5%, P = 0.14), and the overall dissolution rate was 48.34% (CNU group 41.5% vs UDCA group 56.5%, P = 0.13). When analyzed according to stone density, response rate was 33.3%, 87.1%, 30.0%, and 6.2% for hypodense, isodense, hyperdense, and calcified stones, respectively. Response rate (85.7% vs 88.2%, P = 0.83) and dissolution rate (81.01% vs 85.38%, P = 0.17) of isodense stones were similar between CNU and UDCA group. When only sludge was considered, the overall response rate was 87.5% (CNU group 71.4% vs UDCA group 94.1%, P = 0.19), and the overall dissolution rate was 85.42% (CNU group 67.9% vs UDCA group 92.7%, P = 0.23). Patients with isodense gallstones and sludge showed much better response to dissolution therapy with CNU and UDCA showing comparable efficacy. Therefore, CT scan should be performed before medication therapy if stone dissolution is intended.

[Cerebrotendinous xanthomatosis: physiopathology, clinical manifestations and genetics]

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disease, caused by genetic deficiency of the 27-hydroxylase enzyme (encoded by CYP27A1). It plays a key role in cholesterol metabolism, especially in bile acid synthesis and in the 25-hydroxylation of vitamin D3 in the liver. Its deficiency causes reduced bile acid synthesis and tissue accumulation of cholestanol. Clinical manifestations are related to the presence of cholestanol deposits and include tendon xanthomas, premature cataracts, chronic diarrhea, progressive neurologic impairment and less frequently coronary heart disease, early onset osteoporosis and abnormalities in the optic disk and retina. An early diagnosis and treatment with quenodeoxycholic acid may prevent further complications, mainly neurological manifestations. This review summarizes cholesterol metabolism related to bile acid synthesis, physiopathology, biochemistry and treatment of cerebrotendinous xanthomatosis.

New cellular and molecular targets for the treatment of portal hypertension

Portal hypertension (PH) is a common complication of chronic liver disease, and it determines most complications leading to death or liver transplantation in patients with liver cirrhosis. PH results from increased resistance to portal blood flow through the cirrhotic liver. This is caused by two mechanisms: (a) distortion of the liver vascular architecture and (b) hepatic microvascular dysfunction. Increment in hepatic resistance is latterly accompanied by splanchnic vasodilation, which further aggravates PH. Hepatic microvascular dysfunction occurs early in the course of chronic liver disease as a consequence of inflammation and oxidative stress and determines loss of the normal phenotype of liver sinusoidal endothelial cells (LSEC). The cross-talk between LSEC and hepatic stellate cells induces activation of the latter, which in turn proliferate, migrate and increase collagen deposition around the sinusoids, contributing to fibrogenesis, architectural disruption and angiogenesis. Therapy for PH aims at correcting these pathophysiological abnormalities: liver injury, fibrogenesis, increased hepatic vascular tone and splanchnic vasodilatation. Continuing liver injury may be counteracted specifically by etiological treatments, while architectural disruption and fibrosis can be ameliorated by a variety of anti-fibrogenic drugs and anti-angiogenic strategies. Sinusoidal endothelial dysfunction is ameliorated by statins and other drugs increasing NO availability. Splanchnic hyperemia can be counteracted by non-selective beta-blockers (NSBBs), vasopressin analogs and somatostatin analogs. Future treatment of portal hypertension will evolve to use etiological treatments together with anti-fibrotic agents and/or drugs improving microvascular function in initial stages of cirrhosis (pre-primary prophylaxis), while NSBBs will be added in advanced stages of the disease.

Liver disease in infancy caused by oxysterol 7 α-hydroxylase deficiency: successful treatment with chenodeoxycholic acid

A child of consanguineous parents of Pakistani origin developed jaundice at 5 weeks and then, at 3 months, irritability, a prolonged prothrombin time, a low albumin, and episodes of hypoglycaemia. Investigation showed an elevated alanine aminotransferase with a normal γ-glutamyl-transpeptidase. Analysis of urine by electrospray ionisation tandem mass spectrometry (ESI-MS/MS) showed that the major peaks were m/z 480 (taurine-conjugated 3β-hydroxy-5-cholenoic acid) and m/z 453 (sulphated 3β-hydroxy-5-cholenoic acid). Analysis of plasma by gas chromatography-mass spectrometry (GC-MS) showed increased concentrations of 3β-hydroxy-5-cholenoic acid, 3β-hydroxy-5-cholestenoic acid and 27-hydroxycholesterol, indicating oxysterol 7 α-hydroxylase deficiency. The patient was homozygous for a mutation (c.1249C>T) in CYP7B1 that alters a highly conserved residue in oxysterol 7 α-hydroxylase (p.R417C) - previously reported in a family with hereditary spastic paraplegia type 5. On treatment with ursodeoxycholic acid (UDCA), his condition was worsening, but on chenodeoxycholic acid (CDCA), 15 mg/kg/d, he improved rapidly. A biopsy (after 2 weeks on CDCA), showed a giant cell hepatitis, an evolving micronodular cirrhosis, and steatosis. The improvement in liver function on CDCA was associated with a drop in the plasma concentrations and urinary excretions of the 3β-hydroxy-Δ5 bile acids which are considered hepatotoxic. At age 5 years (on CDCA, 6 mg/kg/d), he was thriving with normal liver function. Neurological development was normal apart from a tendency to trip. Examination revealed pes cavus but no upper motor neuron signs. The findings in this case suggest that CDCA can reduce the activity of cholesterol 27-hydroxylase - the first step in the acidic pathway for bile acid synthesis.

Clinical and radiological findings of a cerebrotendinous xanthomatosis patient with a novel p.A335V mutation in the CYP27A1 gene

We herein describe the case of a Japanese cerebrotendinous xanthomatosis (CTX) patient with a novel CYP27A1 gene mutation. The patient had been diagnosed with cataracts at 25 years of age and subsequently developed neurological symptoms in his forties, being referred to our hospital at 47 years of age. Upon admission, Achilles tendon xanthomas, cognitive impairment, dysphagia, dysarthria, dystonia, spasticity, muscle weakness and ataxia were observed. Brain MRI revealed abnormal signals in the dentate nuclei, periventricular white matter and pyramidal tract, and the serum cholestanol level was elevated. A CYP27A1 gene analysis identified compound heterozygosity for p.A335V, a novel mutation, and p.R405Q, a previously reported mutation. Making an early diagnosis of CTX is crucial, as the administration of chenodeoxycholic acid reverses metabolic derangement.

[Clinical features of a Chinese infant with inborn error of bile acid metabolism-3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency and review of the literature]

OBJECTIVE

To study the clinical features of children with 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency and review the literature.

METHOD

Clinical features and treatment of one Chinese infant with 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency confirmed by HSD3B7 gene mutation analysis were retrospectively reviewed, and 51 cases of 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency who were internationally reported since 2000 were also reviewed in this paper.

RESULT

(1) A 3-month-old infant with neonatal cholestasis was admitted to our hospital because of hyperbilirubinemia and abnormal liver dysfunction (total bilirubin 110.7 µmol/L, direct bilirubin 74.5 µmol/L, γ-glutamyltransferase 24.4 IU/L, total bile acid 0.1 µmol/L).His jaundice disappeared within a few weeks, serum liver biochemistries improved and his growth in weight and height was excellent after oral cholic acid therapy.HSD3B7 gene analysis using peripheral lymphocyte genomic DNA from the patient identified compound heterozygous mutations. This child was confirmed as the most common inborn error of bile acid metabolism-3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency by molecular analysis.(2) Retrospective review of the literature showed that the clinical features of 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency included neonatal cholestasis, some patients progressed to severe liver disease and needed liver transplantation without effective therapy; however, serum biochemical characteristics of normal γ-glutamyltransferase activity, normal or low total bile acid concentrations were not consistent with cholestasis, the replacement treatment with cholic acid produced a dramatic improvements in symptoms, biochemical markers of liver injury; 31 cases were diagnosed by HSD3B7 gene mutation analysis.

CONCLUSION

The clinical characteristics of 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency include neonatal cholestasis, normal serum γ-glutamyltransferase activity, and normal or low serum total bile acid concentration.Oral cholic acid replacement is an effective therapy; definitive diagnosis of 3β-hydroxy-Δ(5)-C27-steroid dehydrogenase deficiency can be identified by molecular genetic testing technology.

Two neonatal cholestasis patients with mutations in the SRD5B1 (AKR1D1) gene: diagnosis and bile acid profiles during chenodeoxycholic acid treatment

BACKGROUND AND AIMS

In two Japanese infants with neonatal cholestasis, 3-oxo-Δ(4)-steroid 5β-reductase deficiency was diagnosed based on mutations of the SRD5B1 gene. Unusual bile acids such as elevated 3-oxo-Δ(4) bile acids were detected in their serum and urine by gas chromatography-mass spectrometry. We studied effects of oral chenodeoxycholic acid treatment.

PATIENTS AND METHODS

SRD5B1 gene analysis used peripheral lymphocyte genomic DNA. Diagnosis and treatment of these two patients were investigated retrospectively and prospectively investigated.

RESULTS

With respect to SRD5B1, one patient was heterozygous (R266Q, a novel mutation) while the other was a compound heterozygote (G223E/R261C). Chenodeoxycholic acid treatment was effective in improving liver function and decreasing unusual bile acids such as 7α-hydroxy- and 7α,12α-dihydroxy-3-oxo-4-cholen-24-oic acids in serum and urine.

CONCLUSION

Primary bile acid treatment using chenodeoxycholic acid was effective for these patients treated in early infancy before the late stage of chronic cholestatic liver dysfunction.

Long-term bone density evaluation in cerebrotendinous xanthomatosis: evidence of improvement after chenodeoxycholic acid treatment

Cerebrotendinous xanthomatosis (CTX) is known to be associated with osteoporosis and a higher incidence of bone fractures. However, the underlying pathogenesis is still unknown, and the effects of long-term replacement therapy with chenodeoxycholic acid (CDCA) on bone mineral density (BMD) have not been fully investigated. We studied 11 CTX patients aged 13-43 years. We performed dual-energy X-ray absorptiometry and assessed serum cholestanol and 25-hydroxyvitamin D (25-OHD) concentrations both at the time of diagnosis and after long-term treatment with CDCA. At baseline, we found low BMD in nine patients, cholestanol elevation in all subjects, and 25-OHD decrease in nine. After a mean follow-up time of 30 months (range 24-36), no substantial clinical changes including bone fractures occurred; and we detected a significant increase of both planar and volumetric BMD as well as normalization of plasma cholestanol levels and increase of serum 25-OHD. Densitometric improvement following CDCA introduction was not correlated to changes of biochemical parameters. Our study confirms the presence of low bone mass in CTX and demonstrates that long-term CDCA treatment increases bone mineral content. In this respect, improvement of vitamin D intestinal absorption secondary to bile acid restoration could play an important role. Moreover, our data strongly suggest the utility of periodic bone density evaluation in CTX patients.

[Cerebrotendinous xanthomatosis is a rare disorder, which requires a specific treatment]

Cerebrotendinous xanthomatosis (CTX) is a rare, but treatable lipid storage disorder caused by mutation in the CYP27A1 gene. The disorder results in deposition of cholestanol in various tissues. The classical CTX phenotype includes diarrhoea, juvenile cataract, xanthoma and progressive neurological symptoms. Studies have shown that progression of symptoms can be halted or even reversed, if treatment with chenodeoxycholic acid is initiated early. The diagnosis of CTX is often delayed due to lack of awareness of the disease. We describe the history, clinical features, biochemical, genetic and magnetic resonance imaging findings of the first reported case of CTX in Denmark.

Testosterone and farnesoid X receptor agonist INT-747 counteract high fat diet-induced bladder alterations in a rabbit model of metabolic syndrome

In the male, metabolic syndrome (MetS) is associated to an increased risk of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). A recently established rabbit model of high fat diet (HFD)-induced MetS showed hypogonadism and the presence of prostate gland alterations, including inflammation, hypoxia and fibrosis. The present study investigated whether HFD-induced MetS might also alter bladder structure and function. Testosterone and the farnesoid X receptor (FXR) agonist INT-747, were evaluated for possible effects on HFD bladder. MetS rabbits develop bladder alterations, including fibrosis (reduced muscle/fiber ratio), hypoxia [2-fold increase as compared to regular diet (RD) group], low-grade inflammation (increased leukocyte infiltration and inflammatory markers) and RhoA/ROCK hyperactivity. Bladder strips from HFD rabbits, pre-contracted with carbachol, showed an overactive response to the selective ROCK inhibitor Y-27632. All these HFD-induced bladder alterations were partially blunted by testosterone and almost completely reverted by INT-747. Both treatments prevented some MetS features (glucose intolerance and visceral fat increase), thus suggesting that their effects on bladder could be ascribed to an improvement of the metabolic and/or hypogonadal state. However, a pathogenetic role for hypogonadism has been ruled out as GnRH analog-induced hypogonadal rabbits, fed a regular diet, did not show any detectable bladder alterations. In addition, INT-747 did not revert the MetS-induced hypogonadal state. FXR mRNA was highly expressed in rabbit bladder and positively associated with visceral fat increase. A direct effect of INT-747 on bladder smooth muscle was further suggested by inhibition of RhoA/ROCK-mediated activity by in vitro experiments on isolated cells. In conclusion, HFD-related MetS features are associated to bladder derangements, which are ameliorated by testosterone or INT-747 administration. INT-747 showed the most marked effects in counteracting MetS-related RhoA/ROCK overactivity, thus opening novel therapeutic opportunities for this drug.

Testosterone protects from metabolic syndrome-associated prostate inflammation: an experimental study in rabbit

Metabolic syndrome (MetS) and benign prostatic hyperplasia (BPH)/lower urinary tract symptoms (LUTS) are often associated. One of their common denominators is hypogonadism. However, testosterone supplementation is limited by concerns for potential prostatic side effects. The objective was to determine whether MetS-associated prostate alterations are prevented by testosterone supplementation. We used a previously described animal model of MetS, obtained by feeding male rabbits a high-fat diet (HFD) for 12 weeks. Subsets of HFD rabbits were treated with testosterone or with the farnesoid X receptor agonist INT-747. Rabbits fed a standard diet were used as controls. HFD-animals develop hypogonadism and all the MetS features: hyperglycemia, glucose intolerance, dyslipidemia, hypertension, and visceral obesity. In addition, HFD-animals show a prostate inflammation. Immunohistochemical analysis demonstrated that HFD-induced prostate fibrosis, hypoxia, and inflammation. The mRNA expression of several proinflammatory (IL8, IL6, IL1β, and TNFα), T lymphocyte (CD4, CD8, Tbet, Gata3, and ROR γt), macrophage (TLR2, TLR4, and STAMP2), neutrophil (lactoferrin), inflammation (COX2 and RAGE), and fibrosis/myofibroblast activation (TGFβ, SM22α, αSMA, RhoA, and ROCK1/ROCK2) markers was significantly increased in HFD prostate. Testosterone, as well as INT-747, treatment prevented some MetS features, although only testosterone normalized all the HFD-induced prostate alterations. Interestingly, the ratio between testosterone and estradiol plasma level retains a significant, negative, association with all the fibrosis and the majority of inflammatory markers analyzed. These data highlight that testosterone protects rabbit prostate from MetS-induced prostatic hypoxia, fibrosis, and inflammation, which can play a role toward the development/progression of BPH/LUTS.

Neuromuscular abnormality and autonomic dysfunction in patients with cerebrotendinous xanthomatosis

BACKGROUND

Cerebrotendinous xanthomatosis (CTX) is a rare lipid-storage disease. Neuromuscular abnormality and autonomic system (ANS) dysfuction in CTX are rarely examined in large-scale studies in the literature. We studied the peripheral nervous system, myopathology, and autonomic system of four CTX patients and performed a literature review of the reported CTX patients with peripheral neuropathy.

METHODS

Four biochemically and genetically confirmed CTX patients, belonging to two families, were included for study and all received nerve conduction study (NCS), muscle biopsy for histopathologic and ultrastructural study, skin biopsy for intraepidermal nerve fiber (INEF) density measurement, autonomic testings including sympathetic skin response, R-R interval variation and head-up tilt test using an automated tilt table to record the changes of blood pressure and heart rate in different postures. The Q-Sweat test was also applied for the detection of sweat amount and onset time of response. The clinical characteristics, study methods and results of 13 studies of peripheral neuropathy in CTX patients in the literature were also recorded for analysis.

RESULTS

The results of NCS study showed axonal sensory-motor polyneuropathy in three CTX cases and mixed axonal and demyelinating sensor-motor polyneuropathy in one. The myopathological and histopathologic studies revealed mild denervation characteristics, but the ultrastructural study revealed changes of mitochondria and the membranous system, and increased amounts of glycogen, lipofuscin and lipid deposition. The ANS study revealed different degrees of abnormalities in the applied tests and the INEF density measurement showed small fiber neuropathy in three of the four CTX patients. The literature review of peripheral neuropathy in CTX revealed different types of peripheral neuropathy, of which axonal peripheral neuropathy was the most common.

CONCLUSIONS

Peripheral neuropathy, especially the subtype of axonal sensori-motor neuropathy, is common in patients with CTX. Evidence of lipid metabolic derangement in CTX can be reflected in ultrastructural studies of muscles. With an adequate multi-parametric evaluation, a high incidence of ANS abnormalities can be seen in this rare lipid-storage disease, and a high incidence of small fiber involvement is also reflected in the IENF density measurement of skin biopsies.

Cerebrotendinous xanthomatosis: a treatable neurodegenerative disease

Cerebrotendinous xanthomatosis is one of the rare forms of treatable hereditary neurodegenerative disorders. It is due to a defect in hydroxylation of cholesterol side chain that impairs oxidative cleavage of cholesterol leading to excess accumulation of cholesterol. Here we present such a case which presented to us with recurrent generalized tonic clonic seizures. He is under treatment for the same and has not neurologically deteriorated since then.

Cerebrotendinous xanthomatosis (CTX): a treatable lipid storage disease

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid storage disease with multi-organ involvement. The clinical manifestations usually start at infancy and develop during the first and second decades of life; infantile-onset diarrhea may be the earliest clinical manifestation of CTX. Additional clinical manifestations are juvenile cataracts, tendon xanthomas, and multiple progressive neurological symptoms. Systemic manifestations that are often found include osteoporosis, heart involvement and premature arteriosclerosis. CTX is caused by mutations in the sterol 27 hydroxylase gene (CYP27) on chromosome 2q35-qter, which is responsible for conversion of cholesterol to cholic and chenodeoxycholic acid. Reduced synthesis of cholic and chenodeoxycholic acid results in failed feedback inhibition of cholesterol production, which in turn leads to increased serum cholestanol concentration and elevated urinary bile alcohols. Early treatment with chenodeoxycholic acid (CDCA) prevents the clinical symptoms and prevents deterioration. Although CTX is rare world wide, genetic islands of high frequency have been reported. In this review we would like to familiarize the reader with this fatal inborn error of metabolism that is possibly under-diagnosed and is preventable once recognized and treated.

Bear bile: dilemma of traditional medicinal use and animal protection

Bear bile has been used in Traditional Chinese Medicine (TCM) for thousands of years. Modern investigations showed that it has a wide range of pharmacological actions with little toxicological side effect and the pure compounds have been used for curing hepatic and biliary disorders for decades. However, extensive consumption of bear bile made bears endangered species. In the 1980's, bear farming was established in China to extract bear bile from living bears with "Free-dripping Fistula Technique". Bear farming is extremely inhumane and many bears died of illness such as chronic infections and liver cancer. Efforts are now given by non-governmental organizations, mass media and Chinese government to end bear farming ultimately. At the same time, systematic research has to be done to find an alternative for bear bile. In this review, we focused on the literature, laboratory and clinical results related to bear bile and its substitutes or alternative in English and Chinese databases. We examined the substitutes or alternative of bear bile from three aspects: pure compounds derived from bear bile, biles from other animals and herbs from TCM. We then discussed the strategy for stopping the trading of bear bile and issues of bear bile related to potential alternative candidates, existing problems in alternative research and work to be done in the future.

Elevated cholesterol precursors other than cholestanol can also be a hallmark for CTX

Cerebrotendinous xanthomatosis (CTX) is an inborn error of bile acid synthesis in which hepatic conversion of cholesterol to cholic and chenodeoxycholic acids is impaired. Patients have abnormal bile alcohols in urine, normal to increased plasma cholesterol concentrations and increased concentrations of plasma cholestanol. Little is known about cholesterol precursors in CTX, however. We studied cholesterol and phytosterol profiles in two siblings with CTX during follow-up. While cholesterol concentrations were low in both patients, plasma cholestanol was 6-fold higher compared to control values. In addition, both siblings had a more than 100-fold increase in 7-dehydrocholesterol (7DHC) and 8-dehydrocholesterol (8DHC). Lathosterol, lanosterol and sitosterol were increased in both patients while concentrations of desmosterol and campesterol were normal. In addition, plasma lathosterol/cholesterol ratios were significantly elevated. After treatment with chenodeoxycholate, both patients showed a marked decrease in cholestanol, 7DHC, 8DHC, lathosterol, lanosterol and sitosterol. In addition, the lathosterol/cholesterol ratio normalized, indicating that overall cholesterol synthesis was sufficiently suppressed. This study shows that elevated cholesterol precursors, other than cholestanol, can be a hallmark for CTX.

[Cerebrotendinous xanthomatosis]

HISTORY AND CLINICAL FINDINGS

A 43-year-old woman had since childhood suffered from progressive dementia. Gait ataxia and mild polyneuropathy were noted in the neurological examination. She also had painful xanthomas of the achilles tendons. A bilateral cataract operation had been performed during adolescence.

INVESTIGATIONS

An elevated concentration of cholestanol and a normal cholesterol level were found in the blood samples. The cerebral computed tomography revealed slight cerebral atrophy, predominantly affecting the cerebellum. Neurophysiological tests detected a sensory polyneuropathy in the legs. In addition the electroencephalogram showed a generalized slowing of electrical activity.

DIAGNOSIS, TREATMENT AND COURSE

Clinical findings and laboratory values indicated the diagnosis of a cerebrotendinous xanthomatosis. After initiation of a drug therapy, based on a combination of an HMG-CoA-reductase inhibitor (simvastatin 20 mg/day) and a bile acid, chenodeoxycholic acid (15 mg/kg/day), further progression of the disease was prevented.

CONCLUSION

The diagnosis of cerebrotendinous xanthomatosis is easily made in patients presenting all clinical symptoms expected in the disease. However, up to 30% of the patients do not show severe xanthomas. Especially in early stages of the disease the diagnosis may be difficult. Treatment can be efficacious and should be started as early as possible to prevent irreversible damage, particularly in the nervous system.

Can pigment gallstones be induced by biliary stricture and prevented by medicine in Guinea pigs?

AIM: To determine the relationship between biliary stricture and pigment gallstone formation, and the prevention of pigment gallstones with medicine.

METHODS: One hundred and eighteen male guinea pigs were randomly divided into four groups: stricture group (S, n = 30) underwent partial ligation of common bile duct, and fed on regular chow; S plus medicine group (S+M, n = 27) underwent the same operation but fed on medicinal chow (0.3 g chenodeoxycholic acid, 0.5 g glucurolactone, and 0.5 g aspirin were mixed up in 1.2 kg regular chow); medicinal control group (C+M, n = 30) was free of operation, and fed on medicinal chow; and control group (C, n = 31) was free of operation and fed on regular chow. One week later, laparotomy was performed, and the bile of gallbladder was collected, measured, and cultured.

RESULTS: Gallstones were identified. Pigment gallstones were induced by biliary stricture in 95% (22/23) of S group. In the S+M group, the incidence of gallstone was reduced to 55% (11/20, vs S group, P < 0.01). The changes of indirect bilirubin and ionized calcium in the bile were consistent with gallstone incidences.

CONCLUSION: Biliary stricture can cause pigment gallstone formation in guinea pigs, and the medicines used can lower the incidence of gallstones. The bilirubin and ionized calcium play important roles in pigment gallstone formation.

Rifampicin-induced CYP3A4 activation in CTX patients cannot replace chenodeoxycholic acid treatment

Cerebrotendinous xanthomatosis (CTX) is a rare neurodegenerative disorder with cholestanol accumulation resulting from mutations in the sterol 27-hydroxylase gene (CYP27A). Conventional treatment includes chenodeoxycholic acid and HMG-CoA reductase inhibitors. Mice with disrupted Cyp27A (Cyp27 KO) do not show elevated cholestanol levels nor develop CTX manifestations. This phenomenon was proposed to be due to murine CYP3A overexpression leading to an alternative pathway for degradation of bile alcohols including cholestanol. Our objective was to examine the influence of CYP3A4 induction on cholestanol elimination in CTX patients. Rifampicin (600 mg/day x 7 days), known to induce the PXR, and thereby to increase CYP3A activity, was used. The degree of CYP3A4 induction was assessed by comparing midazolam pharmacokinetics before and after rifampicin treatment. Cholestanol levels and cholestanol/cholesterol ratios were assayed during the experimental period and compared to a 3 weeks period without treatment. The results show that despite 60% increase in CYP3A4 activity following rifampicin treatment, there is no significant change in cholestanol levels. We conclude that up-regulated expression of CYP3A affects cholestanol elimination in mice differently as compared to its effect in CTX patients. Therefore, CYP3A4 inducers cannot replace chenodeoxycholic acid for the treatment of CTX.

Bile acids and lipoprotein metabolism: effects of cholestyramine and chenodeoxycholic acid on human hepatic mRNA expression

Modulation of bile acid synthesis in human by cholestyramine or by chenodeoxycholic acid (CDCA) treatment affects lipoprotein metabolism leading to altered plasma lipid levels. The molecular changes caused by these treatments, which in turn influence lipoprotein metabolism, are still not entirely known in humans. In this study, mRNA levels were analyzed using real time RT-PCR in liver tissue from patients undergoing cholecystectomy due to gallstone disease. The patients were treated with either CDCA (n=6) or cholestyramine (n=5) for three weeks prior to surgery, six patients received no treatment and served as controls. Cholestyramine increased the expression of the LDL receptor (LDLR) by about 65% and that of proprotein convertase subtilisin kexin 9 (PCSK9) by 70%. After CDCA the levels of both LDLR and hydroxy-methyl-glutaryl coenzyme A reductase mRNA decreased approximately by 50%. The expression of PCSK9 was not changed. The mRNA levels of PCSK9, LDLR, and HMGCoAR were significantly correlated to those of sterol regulatory element binding protein 2 (SREBP2), indicating that SREBP2 is of importance in the regulation of the expression of these genes also in human liver.

A novel chenodeoxycholic derivative HS-1200 enhances radiation-induced apoptosis in MCF-7 cells

HS-1200, a synthetic chenodeoxycholic acid derivative, has cytotoxic activity in various human cancer cells. The present study was undertaken to examine whether HS-1200 sensitizes radiation-induced apoptosis in MCF-7 human breast carcinoma cells. Clonogenic assay elucidated that the combination treatment with HS-1200 and radiation induced more cytotoxic effects than the radiation treatment alone. Nuclear staining, DNA electrophoresis and Western blot analysis for poly(ADP-ribose) polymerase revealed that the increased cytotoxic effect by the combination treatment resulted from the augmentation of apoptosis. There was an increase in the expression level of Bax and its translocation onto the mitochondria, a reduction in the mitochondrial membrane potential in the earlier time-points, and the release of cytochrome c into the cytosol increased in the MCF-7 cells treated with radiation and HS-1200 compared to the cells treated only with radiation. Therefore, the synthetic bile acid derivative, HS-1200, could have the therapeutic potential as a radiosensitizer in MCF-7 cells.

Could steroids mask the diagnosis of cerebrotendinous xanthomatosis?

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder of bile acid synthesis, caused by impaired hydroxylation of cholesterol side chains due to deficiency of the mitochondrial enzyme sterol 27-hydroxylase (CYP27A1), leading to accumulation of cholestanol and cholesterol in brain and other tissues. Elevated plasma cholestanol serves as a key marker for the clinical diagnosis of CTX. In the present report we describe a young man with CTX who was on high dose steroids for a misdiagnosed chronic inflammatory demyelinating polyneuropathy (CIDP) and had normal level of serum cholestanol. When steroids were discontinued, markedly elevated serum cholestanol was measured concomitant with marked clinical worsening. This observation may imply that steroids can lower plasma cholestanol, possibly by directly inducing residual CYP27A1 activity or by inducing alternative pathways for cholestanol elimination.

Cerebrotendinous xanthomatosis: possible higher prevalence than previously recognized

BACKGROUND

Cerebrotendinous xanthomatosis (CTX) is a rare but treatable neurodegenerative disorder caused by 27-sterol hydroxylase (CYP27) deficiency.

OBJECTIVE

To describe clinical features and results of genetic analysis in a family with CTX.

DESIGN

Case report.

SETTING

University hospital. Subjects A 54-year-old woman with CTX, her family members, and 115 white control subjects.

MAIN OUTCOME MEASURES

Results of clinical evaluation and magnetic resonance imaging of the brain in the affected subject; results of mutation analysis of the CYP27 coding sequence in the patient, her parents, and the control subjects.

RESULTS

The proband and her affected sibling had classic features of CTX, including presenile cataracts, tendon xanthomas, diarrhea, and a complex neurodegenerative disorder. They were somewhat atypical, however, because their cataracts were congenital, cognitive impairment had been noted in childhood, and the white matter involvement was more severe than usual. The proband was shown to be homozygous for CYP27 mutation R362C. Similar analysis of 115 control subjects identified 1 subject who was a heterozygous carrier for this same CYP27 mutation.

CONCLUSIONS

The prevalence of CTX due to CYP27 mutation R362C alone is approximately 1 per 50,000 among white individuals. Although the disorder is rare, this incidence is substantially greater than previously recognized. Greater awareness of CTX is important because specific treatment is available.

Inherited cholesterol lipidosis: cerebrotendinous xanthomatosis (van Bogaert Scherer Epstein disease). A clinicopathological study

Cerebrotendinous xanthomathosis (CTX) is a rare autosomal-recessively transmitted disease of the lipid storage system with an array of general and neurological symptoms, based on the pathological storage of cholestanol and cholesterol. The histologic manifestations are foamy cell granulomata and cholesterol crystals within various tissues, associated with a loss of both nerve cells and demyelination inside the CNS. We present a case of CTX with clinical progression as well as the pathomorphologic autopsy findings. The CNS affection in our case will be demonstrated and the pathogenesis be discussed. Medical treatment of CTX is possible but with variable success. In the case shown, the patient profited only marginally from a long-term application of chenodeoxycholic acid.

Synthetic chenodeoxycholic acid derivatives inhibit glioblastoma multiform tumor growth in vitro and in vivo

We previously reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis-inducing activity on various cancer cells in vitro. This study was undertaken to explore whether synthetic CDCA derivatives, HS-1199 and HS-1200, had an anticancer effect on malignant glioblastoma cells. We administered them in culture to U-118MG, U-87MG, T98G, and U-373MG cells. The tested glioblastoma cells showed several lines of apoptotic manifestations, such as activation of caspase-3, degradation of DFF, production of poly(ADP-ribose) polymerase cleavage, nuclear condensation, inhibition of proteasome activity, reduction of mitochondrial membrane potential and the release of cytochrome c to cytosol and translocation of AIF to nuclei. Between the two synthetic derivatives, HS-1200 showed a stronger apoptosis-inducing effect than HS-1199. In vivo efficacy of HS-1200 was tested in U87MG cells inoculated into non-obese diabetic and severe combined immunodeficient (NOD/SCID) mice. The HS-1200 treatment significantly inhibited the increase of tumor size in NOD/SCID mice and prolonged the life spans. This study supports the possibility of synthetic CDCA derivatives as a potential chemotherapeutic agent.

Isotopomer spectral analysis of intermediates of cholesterol synthesis in patients with cerebrotendinous xanthomatosis

Four patients with cerebrotendinous xanthomatosis (CTX) and 2 healthy controls received a constant proximal intraduodenal infusion of 1- 13 C-acetate as a stable-isotope-labeled marker of sterol synthesis. One patient was treated with pravastatin (20 mg twice daily) and another patient with chenodeoxycholic acid (250 mg tid). Every hour, venous blood and duodenal samples were obtained. Stable-isotope enrichment of neutral and polar sterols in serum and bile was assessed by gas chromatography/mass spectrometry. Isotopomer spectral analysis was performed on cholesterol, lathosterol, Delta-8-cholesterol, methylsterol, and lanosterol. Stable-isotope labeling of cholestanol, bile acids, and bile alcohols was analyzed by assessing the change over time of the ratio of M + 3 to M + 0. Eleven hours after marker infusion, we found up to 50% newly synthesized lathosterol in serum and up to 80% in bile, with similar results for other cholesterol precursors. In cholesterol, stable-isotope labeling could be demonstrated in all study subjects with a more prominent labeling in bile than in serum. No stable-isotope labeling was detected in cholestanol. Only minor stable-isotope incorporation was detectable in polar sterols in some subjects. Therapy with pravastatin did not have any effect on fractional or absolute synthesis rates or on the concentrations of cholestanol or cholesterol precursors compared to untreated patients with CTX. In contrast, therapy with chenodeoxycholic acid markedly lowered the concentrations of cholestanol and cholesterol precursors, led to a disappearance of bile alcohols, and reduced absolute synthesis rates of lathosterol. Isotopomer spectral analysis proved to be a powerful method to assess the endogenous synthesis of cholesterol precursors in patients with CTX. Higher fractional synthesis in bile than in serum may be due to the size of the pools in bile vs serum. Cholestanol exhibits no marker uptake and is therefore probably synthesized from preformed cholesterol. Biliary cholesterol secretion in patients with CTX is decreased compared to healthy controls.

Protective effects of 6-ethyl chenodeoxycholic acid, a farnesoid X receptor ligand, in estrogen-induced cholestasis

The farnesoid X receptor (FXR), an endogenous sensor for bile acids, regulates a program of genes involved in bile acid biosynthesis, conjugation, and transport. Cholestatic liver diseases are a group of immunologically and genetically mediated disorders in which accumulation of endogenous bile acids plays a role in the disease progression and symptoms. Here, we describe the effect of 6-ethyl chenodeoxycholic acid (6-ECDCA or INT-747), a semisynthetic bile acid derivative and potent FXR ligand, in a model of cholestasis induced by 5-day administration of 17alpha-ethynylestradiol (E(2)17alpha) to rats. The exposure of rat hepatocytes to 1 microM 6-ECDCA caused a 3- to 5-fold induction of small heterodimer partner (Shp) and bile salt export pump (bsep) mRNA and 70 to 80% reduction of cholesterol 7alpha-hydroxylase (cyp7a1), oxysterol 12beta-hydroxylase (cyp8b1), and Na(+)/taurocholate cotransporting peptide (ntcp). In vivo administration of 6-ECDCA protects against cholestasis induced by E(2)17alpha. Thus, 6-ECDCA reverted bile flow impairment induced by E(2)17alpha, reduced secretion of cholic acid and deoxycholic acid, but increased muricholic acid and chenodeoxycholic acid secretion. In vivo administration of 6-ECDCA increased liver expression of Shp, bsep, multidrug resistance-associated protein-2, and multidrug resistance protein-2, whereas it reduced cyp7a1 and cyp8b1 and ntcp mRNA. These changes were reproduced by GW4064, a synthetic FXR ligand. In conclusion, by demonstrating that 6-ECDCA protects against E(2)17alpha cholestasis, our data support the notion that development of potent FXR ligands might represent a new approach for the treatment of cholestatic disorders.