High levels of plant sterols and cholesterol precursors in cerebrotendinous xanthomatosis

An elegant technology for ultrasensitive impedimetric and voltammetric determination of cholestanol based on a novel molecularly imprinted electrochemical sensor

In this work, a novel molecularly imprinted electrochemical sensor (MIES) has been fabricated based on electropolymerization of a molecularly imprinted polymer (MIP) onto a glassy carbon electrode (GCE) modified with gold-palladium alloy nanoparticles (AuPd NPs)/polydopamine film (PDA)/multiwalled carbon nanotubes-chitosan-ionic liquid (MWCNTs-CS-IL) for voltammetric and impedimetric determination of cholestanol (CHO). Modifications applied to the bare GCE formed an excellent biocompatible composite film which was able to selectively detect CHO molecules. Modifications applied to the bare GCE were characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (SEM). Under optimal experimental conditions, the sensor was able to detect CHO in the range of 0.1-60 pM and 1-50 pM by EIS and DPV, respectively. Moreover, the sensor showed high sensitivity, selectivity, repeatability, reproducibility, low interference and good stability towards CHO determination. Our records confirmed that the sensor was successfully able to the analysis real samples for determination of CHO.

Case Report: Early Treatment With Chenodeoxycholic Acid in Cerebrotendinous Xanthomatosis Presenting as Neonatal Cholestasis

Background: Cerebrotendinous xanthomatosis (CTX) is an inborn disorder of bile acid synthesis which causes progressive accumulation of toxic metabolites in various organs, particularly in brain and tendons. Most cases are diagnosed and treated in the second or third decade of life, when neurological involvement appears. We describe a case of CTX presenting as neonatal cholestasis. Results: The child presented cholestasis at 2 months of life. In the following months jaundice slowly disappeared, with a normalization of bilirubin and aminotransferases, respectively, at 6 and 8 months. A LC-Mass Spectrometry of the urines showed the presence of cholestanepentols glucuronide, which led to the suspicion of cerebrotendinous xanthomatosis. The diagnosis was confirmed by the dosage of cholestanol in serum and the molecular genetic analysis of the CYP27A1 gene. Therapy with chenodeoxycholic acid (CDCA) was started at 8 months and is still ongoing. The child was monitored for 13 years by dosage of serum cholestanol and urinary cholestanepentols. A strictly biochemical and neurological follow up was performed and no sign of neurological impairment was observed. Conclusions: Prompt diagnosis and treatment of CTX presenting as neonatal cholestasis may prevent further neurological impairment.

The safety and effectiveness of chenodeoxycholic acid treatment in patients with cerebrotendinous xanthomatosis: two retrospective cohort studies

OBJECTIVE

To evaluate the safety and effectiveness of chenodeoxycholic acid (CDCA) treatment in patients with cerebrotendinous xanthomatosis (CTX).

METHODS

Two retrospective cohort studies were conducted in CTX patients who underwent CDCA treatment: one in the Netherlands (NL; CDCA-STUK-15-001) and one in Italy (IT; CDCA-STRCH-CR-14-001). Eligible patients were aged 2-75 years, had been diagnosed with CTX, and were treated with CDCA orally for ≥1 year. The impact of CDCA treatment on biochemical markers (including serum cholestanol levels) and disease signs and symptoms were assessed, in addition to the safety and tolerability of CDCA treatment.

RESULTS

A total of 35 patients were screened in the NL study and were diagnosed with CTX at 25.6 (± 13.7 SD) years on average. These patients were treated with CDCA and followed up for a median of 9.00 (range: 0.4-26.3) years. In addition, 28 patients were enrolled in the IT study and were diagnosed at 35.0 (± 11.4 SD) years on average (median duration of CDCA treatment: 5.75 [range: 0.0-25.0] years). Signs and symptoms of disease resolved, improved, or remained stable in many patients, with concomitant improvements in biochemical marker levels (serum cholestanol, p < 0.001; 7α-hydroxy-4-cholesten-3-one, p < 0.001 [IT study]).

CONCLUSIONS

The outcomes of these retrospective cohort studies indicate that CDCA is effective in the long-term treatment of CTX, with an acceptable safety profile.

Epidemiology, diagnosis, and treatment of cerebrotendinous xanthomatosis (CTX)

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder of bile acid synthesis caused by mutations in the cytochrome P450 CYP27A1 gene that result in production of a defective sterol 27-hydroxylase enzyme. CTX is associated with abnormally high levels of cholestanol in the blood and accumulation of cholestanol and cholesterol in the brain, tendon xanthomas, and bile. Hallmark clinical manifestations of CTX include chronic diarrhea, bilateral cataracts, tendon xanthomas, and neurologic dysfunction. Although CTX is a rare disorder, it is thought to be underdiagnosed, as presenting signs and symptoms may be nonspecific with significant overlap with other more common conditions. There is marked variability in signs and symptoms, severity, and age of onset between patients. The disease course is progressive and potentially debilitating or fatal, particularly with respect to neurologic presentations that can include intellectual disability, autism, behavioral and psychiatric problems, and dementia, among others. Treatment with chenodeoxycholic acid (CDCA; chenodiol) is the current standard of care. CDCA can help restore normal sterol, bile acid, bile alcohol, and cholestanol levels. CDCA also appears to be generally effective in preventing adverse clinical manifestations of the disease from occurring or progressing if administered early enough. Improved screening and awareness of the condition may help facilitate early diagnosis and treatment.

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.

Neurodermatology

Since the skin and the central and/or peripheral nervous system share a common source (the ectoderm), numerous genetic and acquired diseases (infectious, tumoral or autoimmune disorders) equally affect both. Neurologic diseases or symptoms such as stroke, cerebral or medullary vascular malformations, peripheral, brain or medullary tumors, epilepsy, ataxia, neurologic infections, or cognitive disorders (dementia, mental retardation) may be associated with specific cutaneous manifestations of which the discovery can facilitate the final diagnosis, thereby leading to specific treatment and/or genetic investigations. Careful examination of the skin, hair, and nails by the neurologist is consequently of the utmost importance; when unusual abnormalities of the skin are discovered or when greater expertise is required, consultation with a dermatologist is frequently advisable.

An ultra performance liquid chromatographic method for determining phytosterol uptake by Caco-2 cells

A simple method for the determination of cellular uptake of phytosterols by Caco-2 cells has been developed by ultra performance liquid chromatography with ultraviolet detection (UPLC-UV). UPLC-UV was established using an ODS column, acetonitrile/H(2)O (9:1, v/v) as a mobile phase, and a detection wavelength at 210 nm. As analytes, β-sitosterol, campesterol, stigmasterol, and brassicasterol were selected based on the abundance in foods and the similarity of their structures. A linear relation was observed between the peak area and the amount of sterol injected from 50 to 2000 pmol (r>0.999) with a relative standard deviation (RSD) of less than 2.5% (n=6). This method was applied to the determination of cellular uptake of phytosterols by Caco-2 cells. Recovery tests showed that phytosterols were extracted from the cell lysates by chloroform and determined by UPLC-UV with a recovery rate of more than 80.2% and an RSD of less than 11.3% (n=3). When Caco-2 cells were incubated with phytosterols at 37°C, their uptake was increased with time in a concentration-dependent manner. This method will be useful for the simultaneous determination of cellular phytosterols in an in vitro intestine model.

Three siblings with Cerebrotendinous Xanthomatosis: a novel mutation in the CYP27A1 gene

Cerebrotendinous Xanthomatosis (CTX) is a rare autosomal recessive lipid storage disease caused by sterol 27-hydroxylase (CYP27) deficiency. We report three CTX siblings that shared a novel mutation of the CYP27A1 gene. These siblings presented with elevated cholestanol levels and typical manifestations such as tendon xanthomas, cataracts, osteopenia, mental retardation, cerebellar ataxia and peripheral neuropathy. All shared the same genetic mutation, c.1146_1151delins and c.1214G>A of CYP27A1. All were treated with 750 mg/day chenodeoxycholic acid (CDCA). In conclusion, one should consider the possibility of CTX in any individual with normocholesterolemic xanthomatosis, early-onset cataracts, mental retardation, cerebellar ataxia and peripheral neuropathy.

[Usefulness of cholestanol levels in the diagnosis and follow-up of patients with cerebrotendinous xanthomatosis]

INTRODUCTION

cerebrotendinous xanthomatosis (CTX) is an autosomal recessive disease caused by a deficiency of mitochondrial enzyme sterol 27-hydrolylase. Such a deficiency results in a reduced production of chenodeoxycholic acid and in an increased formation of cholestanol. It is clinically characterized by cataracts, diarrhoea, xanthomas, premature arteriosclerosis and a number of progressive neurological symptoms. Although cholestanol levels are used for the diagnosis of CTX, their correlation with the clinical symptoms and their prognostic usefulness have not been assessed so far.

METHODS

we reviewed 14 CTX patients diagnosed between 1995 and 2008 in two reference centres for the genetic diagnosis of this disorder, whose cholestanol levels had been recorded. We studied the main demographic, clinical and therapeutical data and their correlation with plasma cholestanol levels.

RESULTS

the average cholestanol level at diagnosis was 105.8 μmol/l. These levels did not correlate with any neurological symptoms or with disability at diagnosis scored by the EDSS. After treatment, all patients achieved a significant reduction in plasma cholestanol levels (average reduction of 91 μmol/l in an average follow-up of 34 months), although only one patient remained clinically stable.

CONCLUSIONS

high cholestanol levels are very useful for diagnosis of CTX but they do not have a prognostic value (they do not correlate with severity). Normalisation of cholestanol levels is not always associated with clinical stabilisation. However, follow-up of cholestanol levels can be useful for the dose adjustment.

Chronic diarrhea and juvenile cataracts: think cerebrotendinous xanthomatosis and treat

Cerebrotendinous xanthomatosis is an autosomal recessive disease of bile acid synthesis caused by 27-hydroxylase deficiency. Treatment with chenodeoxycholic acid normalizes cholestanol concentrations and abrogates progression of the disease. We present 4 patients with cerebrotendinous xanthomatosis within 1 family who were treated with chenodeoxycholic acid for 14 years. Two young sisters started treatment at the preclinical stage before the appearance of major symptoms. Their 2 older uncles, who had already developed the complete phenotypic form of cerebrotendinous xanthomatosis when diagnosed, commenced treatment at the same time as the sisters, thus establishing a natural control group. After 14 years of chenodeoxycholic acid therapy, the cholestanol levels of all 4 patients decreased to normal levels (<6 microg/mL). Both sisters remained asymptomatic. Only moderate improvement in symptoms was observed in their uncles. In this long-term study, prompt preclinical administration of chenodeoxycholic acid in early childhood completely prevented the cerebrotendinous xanthomatosis phenotype in 2 sisters. Pediatricians should be aware of this diagnostic possibility of cerebrotendinous xanthomatosis in children presenting with chronic diarrhea and juvenile cataracts. Prevention is particularly significant in light of the availability of early genetic diagnosis and the devastating effects of this illness if not treated.

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.

New insights into the pathological mechanisms of cerebrotendinous xanthomatosis in the Taiwanese using genomic and proteomic tools

Cerebrotendinous xanthomatosis (CTX) is an autosomal recessive lipid-storage disorder caused by a deficiency of the mitochondrial sterol 27-hydroxylase. Genetic analysis utilizing SSCP and direct DNA sequencing identified a new mutation. One base-pair of cytosine was deleted at codon 326 on exon 2 of CYP27 in all CTX patients while their father was heterozygotic. This novel point deletion predicts a frameshift in mRNA (Pro(102) -->Leu) and results in the appearance of a premature termination codon (TGA) to substitute for Val(106) (GTG). To characterize the pathological mechanism of CTX patients, the protein profiles of serum and leukocytes extracted from these subjects were presented by means of proteomic technologies including 2-DE and MALDI-TOF analysis. According to the results, the amount of vinculin, ABP-280, talin and vimentin in leukocytes of CTX patients had changed significantly, reflecting the changes in membrane dynamics concerning cholestanol accumulation. The expression of target proteins in CTX patients and control was further verified by western blotting which indicated the same tendency as 2-DE data. This is the first paper to integrate both genomic and proteomic concepts for analyzing the possible mechanism of CTX and provides more information for related study in the future.

A new method for determination of serum cholestanol by high-performance liquid chromatography with ultraviolet detection

We developed a method for the determination of serum 5alpha-cholestan-3beta-ol (cholestanol). The sterols were derivatized to the 4'-bromobenzenesulfonyl esters and heated in isopropanol. The cholesterol-4'-bromobenzenesulfonate was solvolyzed to cholesteryl isopropyl ether, but the derivatized cholestanol did not change and could be measured in a high-performance liquid chromatographic system equipped with a UV detector at 235 nm. On the other hand, the resulting cholesteryl isopropyl ether, having different absorbance and chromatographic mobility was not detected. This method was used for measuring cholestanol levels in patients with cerebrotendinous xanthomatosis (CTX), liver cirrhosis and serum from healthy control subjects. Reproducibility, linearity and recovery tests were done on 0.3 ml of serum samples containing >2 microg/ml cholestanol, using stigmastanol as an internal standard (I.S.). Determining cholestenol by this method can be used for diagnosis and follow-up of patients with CTX and various liver diseases.

Cancer and low levels of plasma cholesterol: the relevance of cholesterol precursors and products to incidence of cancer

BACKGROUND

It is proposed that the mechanism responsible for the low plasma cholesterol-cancer associations reported in the literature is related to blood and tissue levels of cholesterol precursors and products, reflecting rates of cholesterol synthesis rather than the plasma cholesterol level itself.

METHODS

Data have been collated from Japanese and Northern European studies on plasma levels of a cholesterol precursor, lathosterol, and one product, cholestanol, each a marker of cholesterol metabolism. Situations in which the rate of cholesterol synthesis is altered have also been examined for their relationship to cancer incidence.

RESULTS

The data though minimal suggest that lathosterol and cholestanol may be higher in the blood of the Japanese compared with the Northern Europeans, despite lower plasma cholesterol levels in the Japanese. In accord with the hypothesis the Japanese have a low incidence of many cancers. Cholesterol synthesis is lowered when dietary cholesterol and fat intake are increased and incidence of cancer is increased in these states. Conversely cholesterol synthesis is raised in vegetarianism, the Mediterranean diet, pregnancy, and lactation, and incidence of some cancers is lowered.

CONCLUSIONS

At least some of the variation in cancer incidence with plasma cholesterol levels and also with dietary saturated fat and cholesterol, as well as vegetarianism, the Mediterranean diet, pregnancy, and lactation, can be accounted for by their effects on the rate of cholesterol synthesis and the level of cholesterol precursors and/or products so generated.

Treatment of cerebrotendinous xanthomatosis: effects of chenodeoxycholic acid, pravastatin, and combined use

Treatments by oral administration of chenodeoxycholic acid (CDCA) alone, 3-hydroxy-3-methylglutaryl (HMG) CoA reductase inhibitor (pravastatin) alone, and combination of the two drugs were attempted for 7 patients with cerebrotendinous xanthomatosis (CTX). CDCA treatment at a dose of 300 mg/day reduced serum cholestanol (67.3% reduction), lathosterol (50.8%), campesterol (61.7%) and sitosterol (12.7%). However, the sera of the patients changed to be "atherogenic"; total cholesterol, triglyceride and low-density lipoprotein (LDL)-cholesterol were increased, while high-density lipoprotein (HDL)-cholesterol was decreased. Contrarily, pravastatin at a dose of 10 mg/day improved the sera of the patients to be markedly "anti-atherogenic", but the reductions of cholestanol (30.4%), lathosterol (44.0%), campesterol (22.9%) and sitosterol (9.6%) were inadequate. Combined treatment with CDCA and pravastatin showed good overlapping of the effects of each drug alone. The sera of the patients were apparently more "anti-atherogenic" than those after CDCA treatment. Serum cholestanol concentration was still 2.7 times higher than in controls, but the serum lathosterol level was within the normal range, indicating that the enhancement of overall cholesterol synthesis in the patients was sufficiently suppressed. Plant sterol levels were also within the normal range. The combination of CDCA and pravastatin was a good treatment for CTX, based on the improvement of serum lipoprotein metabolism, the suppression of cholesterol synthesis, and reductions of cholestanol and plant sterol levels. In all of 7 patients, the progression of disease was arrested, but dramatic effects on clinical manifestations, xanthoma, and electrophysiological findings could not be found after the treatment of these drugs.

Treatment of cerebrotendinous xanthomatosis with low-density lipoprotein (LDL)-apheresis

We studied the effects of LDL-apheresis on the biochemical and clinical abnormalities of 5 patients with cerebrotendinous xanthomatosis (CTX). Levels of both cholestanol and cholesterol decreased to approximately 60% of those of pretreatment after one perfusion and gradually returned to their initial levels within 2 weeks. Improvement of clinical manifestations and regression of Achilles tendon xanthomas were detected after several perfusions, though dramatic changes could not be recognized. EEG abnormalities were improved immediately after LDL-apheresis in one patient. We conclude that LDL-apheresis may affect the serum cholestanol level and clinical manifestations in patients with CTX.