A randomized trial to examine the impact of food on pharmacokinetics of 4-phenylbutyrate and change in amino acid availability after a single oral administration of sodium 4-phenylbutyrarte in healthy volunteers.

Urea cycle disorders (UCDs), inborn errors of hepatocyte metabolism, result in the systemic accumulation of ammonia to toxic levels. Sodium 4-phenylbutyrate (NaPB), a standard therapy for UCDs for over 20 years, generates an alternative pathway of nitrogen deposition through glutamine consumption. Administration during or immediately after a meal is the accepted use of NaPB. However, this regimen is not based on clinical evidence. Here, an open-label, single-dose, five-period crossover study was conducted in healthy adults to investigate the effect of food on the pharmacokinetics of NaPB and determine any subsequent change in amino acid availability. Twenty subjects were randomized to one of four treatment groups. Following an overnight fast, NaPB was administered orally at 4.3 g/m2 (high dose, HD) or 1.4 g/m2 (low dose, LD) either 30 min before or just after breakfast. At both doses, compared with post-breakfast administration, pre-breakfast administration significantly increased systemic exposure of PB and decreased plasma glutamine availability. Pre-breakfast LD administration attenuated plasma glutamine availability to the same extent as post-breakfast HD administration. Regardless of the regimen, plasma levels of branched-chain amino acids (BCAA) were decreased below baseline in a dose-dependent manner. In conclusion, preprandial oral administration of NaPB maximized systemic exposure of the drug and thereby its potency to consume plasma glutamine. This finding may improve poor medication compliance because of the issues with odor, taste, and pill burden of NaPB and reduce the risk of BCAA deficiency in NaPB therapy.

O-glycosylated clusterin as a sensitive marker for diagnosing early stages of prostate cancer.

BACKGROUND: Prostate-specific antigen (PSA) has been the most popular diagnostic marker for prostate cancer. The frequent occurrence of low PSA values (<10 ng/ml) in patients with highly suspicious prostate cancer, however, has undermined the accuracy of clinical examinations. The aim of this study was to develop a better resolution for diagnosing prostate cancer to overcome the disadvantage of PSA. METHODS: We focused on the glycosylation status of patients' serum proteins and conducted comprehensive lectin microarray analyses to characterize N- and O-glycans using sera from prostate cancer and benign prostatic diseases. Next, we retrieved candidate serum proteins with characteristic glycan structures using lectin-immobilized beads and identified them by quantitative mass spectrometry using a technique referred to as isobaric tag for relative and absolute quantitation (iTRAQ) labeling. Finally, we constructed a new assay to quantify a candidate glycoprotein with the newly identified glycans. RESULTS: Lectin microarray analyses revealed that sera from patients with prostate cancer had a higher affinity for Jacalin, Amaranthus caudatus (ACA) lectin, and Maclura pomifera (MPA) lectin, compared with that from patients with benign prostatic diseases and normal subjects, suggesting that O-glycosylated proteins are more abundant in sera from patients with prostate cancer. Then, serum glycoproteins preferentially adsorbed onto Jacalin-Agarose as well as biotin-ACA/and biotin-MPA/streptavidin-immobilized magnetic beads were isolated, labeled with iTRAQ, and identified using quantitative mass spectrometry. It was found that the ACA- and MPA-recognizable clusterin was more enriched in patients' sera from prostate cancer compared with those from benign prostatic diseases. Following this discovery, we constructed a Luminex-based assay to quantify O-glycosylated clusterin, in which total serum clusterin was first captured on anti-clusterin antibody-immobilized beads, and then clusterin-associated O-glycans were determined by the pair of biotin-MPA and streptavidin-phycoerythrin. When PSA values registered less than 10 ng/ml, the corresponding serum level of MPA-recognized clusterin determined by this assay was beneficial for distinguishing the patients with prostate cancer from the patients with benign prostatic disease. CONCLUSION: For PSA values that measure less than 10 ng/ml, the serum O-glycosylated clusterin level can be a complementary indicator for the malignancy of prostate cancer.

FABP3 and brown adipocyte-characteristic mitochondrial fatty acid oxidation enzymes are induced in beige cells in a different pathway from UCP1.

Cold exposure and ß3-adrenergic receptor agonist (CL316,243) treatment induce the production of beige cells, which express brown adipocytes(BA)-specific UCP1 protein, in white adipose tissue (WAT). It remains unclear whether the beige cells, which have different gene expression patterns from BA, express BA-characteristic fatty acid oxidation (FAO) proteins. Here we found that 5 day cold exposure and CL316,243 treatment of WAT, but not CL316,243 treatment of primary adipocytes of C57BL/6J mice, increased mRNA levels of BA-characteristic FAO proteins. These results suggest that BA-characteristic FAO proteins are induced in beige cells in a different pathway from UCP1.

Rats harboring S284L Chrna4 mutation show attenuation of synaptic and extrasynaptic GABAergic transmission and exhibit the nocturnal frontal lobe epilepsy phenotype.

Mutations of genes encoding alpha4, beta2, or alpha2 subunits (CHRNA4, CHRNB2, or CHRNA2, respectively) of nAChR [neuronal nicotinic ACh (acetylcholine) receptor] cause nocturnal frontal lobe epilepsy (NFLE) in human. NFLE-related seizures are seen exclusively during sleep and are characterized by three distinct seizure phenotypes: "paroxysmal arousals," "paroxysmal dystonia," and "episodic wandering." We generated transgenic rat strains that harbor a missense mutation S284L, which had been identified in CHRNA4 in NFLE. The transgenic rats were free of biological abnormalities, such as dysmorphology in the CNS, and behavioral abnormalities. The mRNA level of the transgene (mutant Chrna4) was similar to the wild type, and no distorted expression was detected in the brain. However, the transgenic rats showed epileptic seizure phenotypes during slow-wave sleep (SWS) similar to those in NFLE exhibiting three characteristic seizure phenotypes and thus fulfilled the diagnostic criteria of human NFLE. The therapeutic response of these rats to conventional antiepileptic drugs also resembled that of NFLE patients with the S284L mutation. The rats exhibited two major abnormalities in neurotransmission: (1) attenuation of synaptic and extrasynaptic GABAergic transmission and (2) abnormal glutamate release during SWS. The currently available genetically engineered animal models of epilepsy are limited to mice; thus, our transgenic rats offer another dimension to the epilepsy research field.