Purification and characterization of cytoplasmic 14C-arginine rich basic proteins of Ehrlich ascites tumor cells

Summary Arginine rich basic proteins from cytoplasm of Ehrlich ascites tumor cells have been separated and partially characterized. All proteins show a cationic character with the following isoelectric points: 8.45, 8.60, 8.70, 8.90, and possess various amount of arginine. The protein of the highest molecular weight (75000) has the greatest amount of arginine (18.1%), specific radioactivity (19760 cpm/mg, min) and isoelectric point (8.9). The significance of those proteins in the cytoplasm of tumor cells has been discussed briefly.     

The chemical synthesis of oligoribonucleotides with selectively placed 2'-O-phosphates

A phosphoramidite, solid support method for the chemical synthesis of oligoribonucleotides containing 2'-O-phosphate at a selected position is presented. Synthesis of these oligoribonucleotides is based on uridine- and adenosine-(2'-O-phosphate)-3'-phosphoramidites, and a new condition for removal of 2'-O-phosphate protecting groups, which does not cleave internucleotide bonds. The structure of oligoribonucleotides with 2'-O-phosphate has been proven by enzymatic digestions and dephosphorylation by yeast 2'-phosphotransferase.     

Neuronal Autophagy: Self-eating or Self-cannibalism in Alzheimer’s Disease

Autophagy is a major intracellular degeneration pathway involved in the elimination and recycling of damaged organelles and long-lived proteins by lysosomes. Many of the pathological factors, which trigger neurodegenerative diseases, can perturb the autophagy activity, which is associated with misfolded protein aggregates accumulation in these disorders. Alzheimer’s disease, the first neurodegenerative disorder between dementias, is characterized by two aggregating proteins, β-amyloid peptide (plaques) and τ-protein (tangles). In Alzheimer’s disease autophagosomes dynamically form along neurites within neuronal cells and in synapses but effective clearance of these structures needs retrograde transportation towards the neuronal soma where there is a major concentration of lysosomes. Maturation of autophago-lysosomes and their retrograde trafficking are perturbed in Alzheimer’s disease, which causes a massive concentration of autophagy elements along degenerating neurites. Transportation system is disturbed along defected microtubules in Alzheimer’s disease brains. τ-protein has been found to control the stability of microtubules, however, phosphorylation of τ-protein or an increase in the total level of τ-protein can cause dysfunction of neuronal cells microtubules. Current evidence has shown that autophagy is developing in Alzheimer’s disease brains because of ineffective degradation of autophagosomes, which hold amyloid precursor protein-rich organelles and secretases important for β-amyloid peptides generation from amyloid precursor. The combination of raised autophagy induction and abnormal clearance of β-amyloid peptide-generating autophagic vacuoles creates circumstances helpful for β-amyloid peptide aggregation and accumulation in Alzheimer’s disease. However, the key role of autophagy in Alzheimer’s disease development is still under consideration today. One point of view suggests that abnormal autophagy induction causes a concentration of autophagic vacuoles rich in amyloid precursor protein, β-amyloid peptide and the elements crucial for its formation, whereas other hypothesis points to marred autophagic clearance or even decrease in autophagic effectiveness playing a role in maturation of Alzheimer’s disease. In this review we present the recent evidence linking autophagy to Alzheimer’s disease and the role of autophagic regulation in the development of full-blown Alzheimer’s disease.     

Association analysis of vitamin D receptor gene polymorphisms with bone mineral density in young women with Graves' disease

Graves' (GD) hyperthyroidism induces accelerated bone turnover that leads to decreased bone mineral density (BMD). The role of the VDR gene in predisposition to primary osteoporosis has been recognized. Recent studies show associations between the VDR gene polymorphisms and susceptibility to autoimmune diseases. Here we analyzed if VDR gene polymorphisms: BsmI, ApaI, TaqI, and FokI may predispose women with Graves' hyperthyroidism to BMD reduction or to disease development. The subjects were 75 premenopausal female Polish patients with GD and 163 healthy women. The genotyping was performed by the use of the restriction fragment length polymorphism analysis (RFLP). We studied the association of the VDR polymorphisms and their haplotypes with patients' BMD and also SNPs and haplotypes association with Graves' disease. We found a strong linkage disequilibrium for the BsmI, ApaI, and TaqI polymorphims that formed three most frequent haplotypes in Graves' women: baT (47.9%), BAt (34.9%), and bAT (16.4%). We did not show statistically significant association of analyzed VDR polymorphisms or haplotypes with decreased bone mineral density in Graves' patients. However, the presence of F allele had a weak tendency to be associated with Graves' disease (with OR=1.93; 95% CI: 0.97-3.84; p=0.058). In conclusion: VDR gene polymorphisms do not predict the risk of decreased BMD in Polish women with Graves'. It may be speculated that the F allele carriers of the VDR-FokI polymorphism are predisposed to Graves' disease development.     

Class 1 Integrons and Antibiotic Resistance of Clinical Acinetobacter calcoaceticus–baumannii Complex in Poznań, Poland

Sixty-three clinical isolates of Acinetobacter calcoaceticus–baumannii complex were analyzed for the presence of integrons and antimicrobial resistance. Class 1 integrons were detected in 40 (63.5 %) isolates. None of them had class 2 or class 3 integrons. The majority of the integrons contained aacC1–orfA–orfB–aadA1 gene cassette array. The presence of integrons was associated with the increased frequency of resistance to 12 of 15 antimicrobials tested, multi-drug resistance phenotype, and the overall resistance ranges of the strains.     

Chemosensory proteins in the honey bee: Insights from the annotated genome, comparative analyses and expressional profiling

Small chemosensory proteins (CSPs) belong to a conserved, but poorly understood protein family that has been implicated in transporting chemical stimuli within insect sensilla. However, their expression patterns suggest that these molecules are also critical for other functions including early development. Here we used both bioinformatics and experimental approaches to characterize the CSP gene family in a social insect, the Western honey bee Apis mellifera, and then compared its members to CSPs in other arthropods. The number of CSPs in the honey bee genome (six) is similar to that found in the sequenced dipteran species (four-seven), but is much lower than the number of CSPs in the moth or in the beetle (around 20 each). These differences seem to be the result of lineage specific expansions. Our analysis of CSPs in a number of arthropods reveals a conserved gene family found in both Mandibulates and Chelicerates. Expressional profiling in diverse tissues and throughout development reveals broader than expected patterns of expression with none of the CSPs restricted to the antennae and one found only in the queen ovaries and in embryos. We conclude that CSPs are multifunctional context-dependent proteins involved in diverse cellular processes ranging from embryonic development to chemosensory signal transduction. Some CSPs may function in cuticle synthesis, consistent with their evolutionary origins in the arthropods.     

Maternal Lead Exposure Produces Long-Term Enhancement of Dopaminergic Reactivity in Rat Offspring

To determine the effect of prenatal lead exposure on brain monoaminergic systems, pregnant rats were given tap water containing 250 ppm lead acetate, for the duration of pregnancy, while tap water without lead (Pb²⁺) was substituted at birth. Control rats were derived from dams that consumed tap water during pregnancy, and had no exposure to lead afterwards. At 12 weeks after birth, Pb²⁺ content of brain cortex was increased 3- to 4-fold (P < 0.05). At this time the endogenous striatal levels of 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid were 19% lower in Pb²⁺ exposed rats (P < 0.05), while there was no change in the striatal level of dopamine (DA), noradrenaline, 3,4-dihydroxyphenylglycol, serotonin (5-HT) and 5-hydroxyindoleacetic acid (HPLC/ED). Also there was no change in these monoamines and metabolites in the prefrontal cortex of Pb²⁺ exposed rats. However, turnover of 5-HT in prefrontal cortex, as indicated by 5-hydroxytryptophan accumulation 30 min after acute treatment with the decarboxylase inhibitor NSD-1015 (100 mg/kg IP), was lower in the Pb²⁺ exposed rats. In the striatum AMPH-induced (1 mg/kg IP) turnover of DA, evidenced as L-DOPA accumulation after NSD-1015, was increased to a lesser extent in the Pb²⁺ exposed rats (P < 0.05). The nitric oxide synthase inhibitor 7-nitroindazole (10 mg/kg IP) attenuated the latter effect, indicating that neuronal NO mediates this AMPH effect, at least in part. Moreover, DA D₂ receptor sensitivity developed in Pb²⁺ exposed rats, as evidenced by enhanced quinpirole-induced yawning activity and enhanced quinpirole-induced locomotor activity (each, P < 0.05). These findings indicate that ontogenetic exposure to lead can have consequences on monoaminergic neuronal function at an adult stage of life, generally promoting accentuated behavioral effects of direct and indirect monoaminergic agonists, and related to increased dopamine turnover in basal ganglia. Special issue dedicated to Dr. Moussa Youdim.     

Assignment of the absolute configuration of P-chiral 5' mRNA cap analogues containing phosphorothioate moiety

Enzymatic cleavage of the P-chiral diastereoisomers of the 5' mRNA cap analogue bearing phosphorothioate moiety in alfa position of 5',5'-triphosphate bridge (m(7)Gppp(S)G D1 and D2) was performed by human Decapping Scavenger (DcpS) enzyme. Analysis of the degradation products allowed to estimate the absolute configuration at the asymmetric phosphorus atoms in examined compounds via correlation with the R(P) and S(P) diastereoisomers of guanosine 5'-O-(1-thiodiphosphate) (GDPalphaS).