Human hepatic CYP1A1 and CYP1A2 content, determined with specific anti-peptide antibodies, correlates with the mutagenic activation of PhIP

Mono-specific antibodies targeted to human CYP1A1 and CYP1A2have been produced by immunizing rabbits with protein conjugatesof short synthetic peptides corresponding to residues 290–297and 284–296 respectively, of these enzymes. The antibodytargeted to CYP1A1 bound in immunoblotting to the recombinantprotein expressed in yeast but did not bind to any human hepaticmicrosomal protein, whereas the antibody targeted to CYP1A2bound only to this enzyme in immunoblotting of human hepaticmicrosomal fractions and did not recognize recombinant humanCYP1A1. The intensity of hepatic microsomal CYP1A2 immunoreactivity(n = 5) correlated significantly with a number of activitiescharacteristic of this enzyme: phenacetin O-deethylase (POD),ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylaseactivities and the ability to activate the dietary carcinogen2-amino-3, 8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), to amutagen. The anti-CYP1A2 anti-peptide antibody consistentlyinhibited both POD and EROD activities, but inhibition was incomplete(28%). In view of the known (>90%) contribution of CYP1A2to these activities and the correlation with antibody binding,this is consonant with an epitope for the anti-CYP1A2 anti-peptideantibody that forms the edge of a functionally important proinhibitorysurface region previously identified in rat cytochromes CYP1A.CYP1A2 immunoreactivity determined by immunoblotting correlatedsignificantly with the ability of human hepatic microsomal fractionsto activate 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine(PhIP), another dietary carcinogen, to a mutagen. It is concludedthat CYP1A1 is absent from human liver and that CYP1A2 is likelyto be a major catalyst in the hepatic activation of PhIP.     

Profile of families with parkinsonism-predominant spinocerebellar ataxia type 2 (SCA2).

Spinocerebellar ataxia type 2 (SCA2) has been recognized recently as an uncommon cause of parkinsonism, an alternate presentation to the typical cerebellar disorder. This research review summarizes the existing literature on parkinsonism-predominant presentation SCA2 and presents new clinical cases of patients with this condition. Various phenotypes are noted in this subtype of SCA2, including parkinsonism indistinguishable from idiopathic Parkinson's disease (PD), parkinsonism plus ataxia, motor neuron disease, and postural tremor. In several kindreds with multiple affected family members, the SCA2 expansion segregated with disease; in addition, several single cases of parkinsonism with and without a family history are also described. The number of repeats in symptomatic patients ranged from 33 to 43. Interruption of the CAG repeat with CAA, CGG, or CCG was found in some individuals, possibly stabilizing the repeat structure and accounting for the relative stability of the repeat size across generations in some families; allele length is not necessarily indicative of trinucleotide repeat architecture. Positron emission tomography scanning in one family showed reduced fluorodopa uptake and normal to increased raclopride binding with a rostrocaudal gradient similar to that found in idiopathic PD. This review emphasizes the importance of testing for SCA2 in patients with parkinsonism and a family history of neurodegenerative disorders. Testing for SCA2 is also important in studies of inherited parkinsonism.     

Glutamine attenuates endotoxin-induced lung metabolic dysfunction: potential role of enhanced heat shock protein 70

OBJECTIVE: Septic shock leads to derangement of cellular metabolism. Enhanced heat shock protein 70 (HSP-70) can preserve cellular metabolism after other forms of cellular stress. Glutamine (GLN) can enhance lung HSP-70 expression after lethal endotoxemia. However, it is unknown whether GLN can enhance HSP-70 expression and attenuate lung metabolic dysfunction after sublethal endotoxemia. Our aim was to determine whether GLN could upregulate HSP-70 and attenuate metabolic dysfunction in lung tissue after sublethal endotoxemia. METHODS: Sprague-Dawley rats were assigned to one of five groups. The first two groups were treated with Escherichia coli lipopolysaccharide (LPS; 1 mg/kg intravenously). GLN (0.75 g/kg intravenously) or balanced salt solution as a control was administered 5 min after LPS administration. The next two groups of rats were treated with quercetin (HSP-70 inhibitor; 400 mg/kg intraperitoneally) 6 h before LPS administration. The final group received no treatment. Lung tissue was harvested 24-h after LPS and analyzed with immunofluorescence and western blot for HSP-70. Tissue metabolites were quantified by 1H and 31P nuclear magnetic resonance spectroscopy. RESULTS: GLN compared with balanced salt solution (BSS) administration in LPS-treated animals led to significant increases in lung HSP-70. Increased HSP-70 expression was observed in lung epithelial cells and macrophages. GLN significantly improved the ratio of adenosine triphosphate to adenosine diphosphate in the lung after LPS. Quercetin inhibited a GLN-mediated increase in lung HSP-70 and blocked a beneficial effect of GLN on the ratio of adenosine triphosphate to adenosine diphosphate after LPS. CONCLUSIONS: A single dose of GLN can enhance HSP-70 in pulmonary epithelial cells and macrophages after sublethal endotoxemia. Further, GLN can attenuate endotoxin-induced lung metabolic dysfunction. GLN's beneficial effect on lung tissue after metabolic dysfunction caused by sublethal endotoxemia may be mediated in part by enhanced HSP-70.     

Analysis of SCA-2 and SCA-3 repeats in Parkinsonism: evidence of SCA-2 expansion in a family with autosomal dominant Parkinson's disease

The spinocerebellar ataxias (SCAs) are progressive neurodegenerative disorders linked to more than 20 genetic loci. Most often, these diseases are caused by expansion of triplet repeats encoding polyglutamine (polyQ) tracts. The phenotype is variable and can cause a disease that overlaps clinically with Parkinson's disease (PD). l-Dopa-responsive parkinsonism with minimal cerebellar deficits has been described in SCA2 and SCA3. In order to define if mutation at these loci is a common cause of clinically defined parkinsonism we typed the SCA-2 and SCA-3 repeats for expansion in a series of 280 patients diagnosed with PD or parkinsonism. We identified one pathogenic expansion in SCA-2 in a North American family with autosomal dominant parkinsonism.