LDLR gene synonymous mutation c.1813C>T results in mRNA splicing variation in a kindred with familial hypercholesterolaemia.

Familial hypercholesterolaemia, one of the most common inherited diseases in the general population, is associated with mutations in at least three different genes including the low density lipoprotein receptor (LDLR), apolipoprotein B (APOB) and protein convertase subtilisin/kexin type 9 (PCSK9) genes. In this report, we describe an unclassified DNA variant (c.1813C>T; p.Leu605Leu) within exon 12 of the LDLR gene in a kindred in which familial hypercholesterolaemia is associated with c.1813C>T heterozygosity. In silico analysis suggested that c.1813C>T might affect splicing of the LDLR gene by creating a cryptic donor splice site, which was confirmed by RT-PCR coupled with cDNA sequencing, to result in the loss of 34 base pairs in the coding sequence. The latter truncated mRNA is predicted to generate a frameshift leading to a premature stop at codon 652 and early termination of the low density lipoprotein receptor polypeptide chain, and thus provides a molecular basis for the hypercholesterolaemic phenotype. This case report highlights the emerging utility of RNA studies for the molecular diagnosis of familial hypercholesterolaemia in patients with potential mRNA splicing variants.

Profiling the impact of medium formulation on morphology and functionality of primary hepatocytes in vitro.

The characterization of fully-defined in vitro hepatic culture systems requires testing of functional and morphological variables to obtain the optimal trophic support, particularly for cell therapeutics including bioartificial liver systems (BALs). Using serum-free fully-defined culture medium formulations, we measured synthetic, detoxification and metabolic variables of primary porcine hepatocytes (PPHs)--integrated these datasets using a defined scoring system and correlated this hepatocyte biological activity index (HBAI) with morphological parameters. Hepatic-specific functions exceeded those of both primary human hepatocytes (PHHs) and HepaRG cells, whilst retaining biotransformation potential and in vivo-like ultrastructural morphology, suggesting PPHs as a potential surrogate for PHHs in various biotech applications. The HBAI permits assessment of global functional capacity allowing the rational choice of optimal trophic support for a defined operational task (including BALs, hepatocellular transplantation, and cytochrome P450 (CYP450) drug metabolism studies), mitigates risk associated with sub-optimal culture systems, and reduces time and cost of research and therapeutic applications.

Elevated levels of the long pentraxin 3 in paracetamol-induced human acute liver injury.

OBJECTIVES: Pentraxin 3 (PTX3) is a long pentraxin with diverse humoral innate immune functions. The aims of this study were to measure levels of PTX3 and C-reactive protein (CRP), a hepatocyte-derived short pentraxin, in patients after acute liver injury. METHODS: PTX3 and CRP levels were measured in a total of 60 patients [48 paracetamol overdose (POD), 12 non-POD]. PTX3 expression was assessed by immunohistochemical analysis in explanted liver tissue. RESULTS: Admission PTX3 levels were significantly higher in POD acute liver failure (ALF) patients compared with POD non-ALF patients (P=0.0005) and non-POD patients (P=0.004). PTX3 levels in POD patients who died or required orthotopic liver transplantation (OLT, n=14) were significantly higher compared with those in spontaneous survivors (n=34, P=0.0011). The area under the receiver operator characteristic for PTX3 for death/OLT in POD patients was 0.80 (95% confidence interval 0.67-0.93). PTX3 levels were significantly higher in those POD patients who developed the systemic inflammatory response syndrome (P=0.001). Conversely, admission CRP levels were significantly lower in POD compared with non-POD patients (P=0.011), with no significant differences between survivors and nonsurvivors. After emergency OLT, PTX3 levels fell markedly; in contrast, CRP levels rapidly increased. Immunohistochemical analysis showed PTX3 expression in sinusoidal lining cells of a normal liver, infiltrating inflammatory cells in patients with ALF, and in a membranous distribution on injured hepatocytes in POD patients. CONCLUSION: Increased PTX3 levels are associated with adverse outcomes following POD, suggesting that the humoral innate immune system plays an underrecognized role in this condition.

Antipsychotics and abnormal liver function tests: systematic review.

OBJECTIVE: Systematic assessment of the prevalence and pattern of liver function test (LFT) abnormalities associated with regular antipsychotics in adult humans and consideration of management of such abnormalities. DATA SOURCES: Systematic search identifying cohort, cross-sectional or case studies/series, reporting LFT abnormalities in patients receiving regular antipsychotics. EMBASE, PsychINFO, and MEDLINE were searched for studies in English from record onset. STUDY SELECTION: Abstracts were independently screened for eligibility by 2 researchers. Ineligible studies included those that did not report LFT reference ranges, those that studied fewer than 10 patients on a given antipsychotic, and those studying children. DATA EXTRACTION: Key variables in group studies were extracted. Case studies/series were examined for patient outcome. DATA SYNTHESIS: Ten group studies and 91 case studies/series were eligible, although quality was poor. All groups receiving regular antipsychotics had a prevalence of LFT abnormalities greater than chance. The median percentage of patients with any abnormal LFT on any antipsychotic was 32%, with a range of 5% to 78%. The median percentage of patients with clinically significant elevations was 4%, with a range of 0% to 15%. Transaminases were most commonly elevated. Abnormalities were generally asymptomatic, arose within 6 weeks, and were either stably persistent or resolved with continued treatment. Case reports suggested that antipsychotics can be associated with severe hepatitis, fatal in a small minority of cases. Chlorpromazine is most commonly associated with acute liver injury. CONCLUSIONS: The LFT abnormalities in patients receiving regular antipsychotics are common but generally mild and transient. Very rarely, a severe or fatal hepatic injury can emerge.

Statins and their interactions with other lipid-modifying medications: safety issues in the elderly.

Inhibitors of the enzyme 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, commonly known as statins, are widely used in both primary and secondary prevention of occlusive cardiovascular disease. Statins are effective not only in improving total and low-density lipoprotein cholesterol concentrations in blood but also in decreasing morbidity and mortality associated with cardiovascular diseases resulting from underlying atheroma. There is, however, evidence that statins are underutilized in elderly patients, possibly due to concerns about safety/tolerability issues or potential drug interactions, including interactions with other lipid-modifying medications, or both. In this review, we summarize the major adverse events associated with statin use, with particular reference to the elderly patient, including factors which might increase the risk of adverse effects. Potential drug interactions between statins and other lipid-modifying medications including fibrates, ezetimibe, nicotinic acid, bile acid sequestrants and omega-3-acid ethyl esters (fish oils) are specifically discussed. Clinical management strategies to avoid these drug interactions are outlined.

Current parathyroid hormone immunoassays do not adequately meet the needs of patients with chronic kidney disease.

BACKGROUND: There are significant differences in plasma parathyroid hormone (PTH) results obtained by current immunoassay methods. However, many clinical guidelines relevant to patients with chronic kidney disease (CKD) that recommend PTH target values do not take account of these differences. This raises major questions about the validity of the evidence underpinning current use of PTH measurements in the management of CKD as well as of published relevant audit data. METHODS: PTH was measured in plasma from patients with CKD in six commercially available immunoassays. The initial pilot study included 19 patients while 98 patients were included in a second extended study. Data from the second study were analysed by regression analysis to obtain assay-specific targets for each immunoassay. RESULTS: Although similar PTH reference intervals are provided by most manufacturers, both studies confirmed substantial between-method differences in observed PTH for all patients, with results varying by as much as 4.2-fold between the lowest and highest reading methods. These differences were sufficient to have treatment implications for 79% of the patients in the pilot study. Applying the assay-specific targets derived here to results from the extended study decreased treatment misclassifications from 53% to 12%. CONCLUSIONS: Existing between-method differences in PTH measurements clearly have treatment implications. International initiatives to address these differences are in progress and will require support and input from all stakeholders. Adoption of assay-specific target values such as those reported here provides a convenient and practical interim solution that should lead to significant improvement in patient management, while also enabling meaningful audit.

Low-shear modelled microgravity environment maintains morphology and differentiated functionality of primary porcine hepatocyte cultures.

Hepatocytes cultured in conventional static culture rapidly lose polarity and differentiated function. This could be explained by gravity-induced sedimentation, which prevents formation of complete three-dimensional (3D) cell-cell/cell-matrix interactions and disrupts integrin-mediated signals (including the most abundant hepatic integrin alpha(5)beta(1)), important for cellular polarity and differentiation. Cell culture in a low fluid shear modelled microgravity (about 10(-2) g) environment promotes spatial colocation/self-aggregation of dissociated cells and induction of 3D differentiated liver morphology. Previously, we demonstrated the utility of a NASA rotary bioreactor in maintaining key metabolic functions and 3D aggregate formation of high-density primary porcine hepatocyte cultures over 21 days. Using serum-free chemically defined medium, without confounding interactions of exogenous bioscaffolding or bioenhancing surface materials, we investigated features of hepatic cellular polarity and differentiated functionality, including expression of hepatic integrin alpha(5), as markers of functional morphology. We report here that in the absence of exogenous biomatrix scaffolding, hepatocytes cultured in serum-free chemically defined medium in a microgravity environment rapidly (<24 h) form macroscopic (2-5 mm), compacted 3D hepatospheroid structures consisting of a shell of glycogen-positive viable cells circumscribing a core of eosinophilic cells. The spheroid shell layers exhibited ultrastructural, morphological and functional features of differentiated, polarized hepatic tissue including strong expression of the integrin alpha(5) subunit, functional bile canaliculi, albumin synthesis, and fine ultrastructure reminiscent of in vivo hepatic tissue. The low fluid shear microgravity environment may promote tissue-like self-organization of dissociated cells, and offer advantages over spheroids cultured in conventional formats to delineate optimal conditions for enhanced directed tissue self-assembly.

Selenium supplementation attenuates procollagen-1 and interleukin-8 production in fat-loaded human C3A hepatoblastoma cells treated with TGFbeta1.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is associated with obesity, insulin resistance and hepatic steatosis. Non-alcoholic steatohepatitis (NASH) is a serious consequence of NAFLD where chronic tissue damage and inflammation result in fibrosis which may progress to cirrhosis. Transforming growth factor beta1 (TGFbeta1), proinflammatory cytokines and oxidative stress are thought to play crucial roles in the pathogenesis of these conditions. The contributions of individual liver cell types to fibrogenesis remain controversial and the influence of selenium status has not been investigated. METHODS: In this study we have used a cell culture model of fat-loading using oleate-treated human hepatoblastoma (C3A) cells to investigate how fat-loading and selenium status might influence the production of collagen in response to TGFbeta1. The secretion of inflammatory cytokines was also investigated, together with the epithelial character of the treated cells. RESULTS: We found that in response to treatment with TGFbeta1, C3A cells produced mRNA encoding the pro-alphaI chain of procollagen I, secreted procollagen I peptide, up-regulated production of the proinflammatory cytokine interleukin-8 (IL-8) and the mesenchymal marker vimentin, and down-regulated albumin production. Most of these responses were considerably enhanced when cells were fat-loaded with oleate and were attenuated by selenium addition at a dose that optimised the expression of thioredoxin reductase and glutathione peroxidase. CONCLUSIONS: Our data establish that both fat-loading and suboptimal selenium status enhance collagen and IL-8 production by C3A hepatocytes in response to TGFbeta1, possibly as part of an epithelial to mesenchymal transition. GENERAL SIGNIFICANCE: These findings suggest that the hepatocyte may be an important contributor to the pathogenesis of fibrosis associated with NAFLD.

Selenium supplementation acting through the induction of thioredoxin reductase and glutathione peroxidase protects the human endothelial cell line EAhy926 from damage by lipid hydroperoxides.

The human endothelial cell line EAhy926 was used to determine the importance of selenium in preventing oxidative damage induced by tert-butyl hydroperoxide (tert-BuOOH) or oxidised low density lipoprotein (LDLox). In cells grown in a low selenium medium, tert-BuOOH and LDLox killed cells in a dose-dependent manner. At 555 mg/l LDLox or 300 microM tert-BuOOH, >80% of cells were killed after 20 h. No significant cell kill was achieved by these agents if cells were pre-incubated for 48 h with 40 nM sodium selenite, a concentration that maximally induced the activities of cytoplasmic glutathione peroxidase (cyGPX; 5.1-fold), phospholipid hydroperoxide glutathione peroxidase (PHGPX;1.9-fold) and thioredoxin reductase (TR; 3.1-fold). Selenium-deficient cells pre-treated with 1 microM gold thioglucose (GTG) (a concentration that inhibited 25% of TR activity but had no inhibitory effect on cyGPX or PHGPX activity) were significantly (P<0.05) more susceptible to tert-BuOOH toxicity (LC(50) 110 microM) than selenium-deficient cells (LC(50) 175 microM). This was also the case for LDLox. In contrast, cells pre-treated with 40 nM selenite prior to exposure to GTG were significantly more resistant to damage from tert-BuOOH and LDLox than Se-deficient cells. Treatment with GTG or selenite had no significant effect on intracellular total glutathione concentrations. These results suggest that selenium supplementation, acting through induction of TR and GPX, has the potential to protect the human endothelium from oxidative damage.