Molecular mechanisms in prostate cancer. A review

Genetic studies have provided remarkable clues to the causes of prostate cancer (PCa). For example, in addition to the expected role of androgens in facilitating the development of PCa, the possibility that infections might lead to prostate cancer has been raised with the identification of RNASEL and MSR1 as familial prostate cancer genes; that insight will profoundly affect future studies and may ultimately lead to new approaches to the prevention of prostate cancer. The identification of key molecular alterations in prostate cancer cells implicates carcinogen defenses, including GSTP1, growth factor signaling pathways (such as NKX3.1, PTEN and p27) and androgens as critical determinants of the phenotype of PCa cells and defines specific targets for detection, diagnosis and treatment of PCa.     

Lipovitellins and phosvitins of the fertilized eggs during embryo growth in the oviparous lizard Podarcis sicula

In the lizard Podarcis sicula, the major vitellogenin (VTG)-derived yolk proteins, lipovitellins and phosvitins, were extracted from the yolk globules of laid and fertilized eggs at different periods of incubation up to 44 days close to hatching. Embryonic development was almost over at this time. Yolk proteins were isolated by precipitation in saturated (NH(4))(2)SO(4), separated on SDS-PAGE and detected by Western blotting with homologous polyclonal anti/VTG antibody. Two lipovitellins of 110 and 116 kDa were always present in the yolk of laid eggs after 1, 10, 18, and 44 days from oviposition. Both these proteins were glycosylated and were recognized by the anti/VTG antibody; their N-terminal sequences were analyzed. Four phosvitins were detected in freshly laid eggs, but their number decreased during incubation, and after 44 days only a single protein of approximately 6.5 kDa was present. The results indicated that, in this lizard, during embryonic development, lipovitellins remain unchanged, whereas the phosphorylated components of yolk undergo continuous degradation.     

SAR study and conformational analysis of a series of novel peptide G protein‐coupled receptor kinase 2 inhibitors

G protein‐coupled receptor kinase 2 (GRK2) plays a central role in the cellular transduction network. In particular, during chronic heart failure GRK2 is upregulated and believed to contribute to disease progression. Thereby, its inhibition offers a potential therapeutic solution to several pathological conditions. In the present study, we performed a SAR study and a NMR conformational analysis of peptides derived from HJ loop of GRK2 and able to selectively inhibit GRK2. From Ala‐scan and d ‐Ala point replacement, we found that Arg residues don't affect the inhibitory properties, while a d ‐amino acid at position 5 is key to the activity. Conformational analysis identified two β‐turns that involve N‐terminal residues, followed by a short extended region. These information can help the design of peptides and peptido‐mimetics with enhanced GRK2 inhibition properties. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 121–128, 2014.     

High CO2 Levels Cause Skeletal Muscle Atrophy via AMP-activated Kinase (AMPK), FoxO3a Protein,and Muscle-specific Ring Finger Protein 1 (MuRF1)

Patients with chronic obstructive pulmonary disease, acute lung injury, and critical care illness may develop hypercapnia. Many of these patients often have muscle dysfunction which increases morbidity and impairs their quality of life. Here, we investigated whether hypercapnia leads to skeletal muscle atrophy. Mice exposed to high CO₂ had decreased skeletal muscle wet weight, fiber diameter, and strength. Cultured myotubes exposed to high CO₂ had reduced fiber diameter, protein/DNA ratios, and anabolic capacity. High CO₂ induced the expression of MuRF1 in vivo and in vitro, whereas MuRF1^−/− mice exposed to high CO₂ did not develop muscle atrophy. AMP-activated kinase (AMPK), a metabolic sensor, was activated in myotubes exposed to high CO₂, and loss-of-function studies showed that the AMPKα2 isoform is necessary for muscle-specific ring finger protein 1 (MuRF1) up-regulation and myofiber size reduction. High CO₂ induced AMPKα2 activation, triggering the phosphorylation and nuclear translocation of FoxO3a, and leading to an increase in MuRF1 expression and myotube atrophy. Accordingly, we provide evidence that high CO₂ activates skeletal muscle atrophy via AMPKα2-FoxO3a-MuRF1, which is of biological and potentially clinical significance in patients with lung diseases and hypercapnia.     

Gleason grading of prostate carcinoma in needle biopsies vs. radical prostatectomy specimens

The Gleason grading system for prostatic carcinoma is the dominant method used around the world in research and in daily practice. It is based on glandular architecture. The grading system should be applied to all prostatic tissue samples, including needle core biopsies and radical prostatectomy specimens. Its prognostic value was tested in a large population with long-term follow-up that included use of survival as an end point. The Gleason grading system shows a reasonable degree of correlation between biopsy and radical prostatectomy specimens. Several sources of discrepancy between these 2 types of specimen have been identified. Further educational endeavors are needed to arrive at a greater consensus and accuracy in the use of the Gleason system.     

Genetic heterogeneity in Italian families with IgA nephropathy: suggestive linkage for two novel IgA nephropathy loci

IgA nephropathy (IgAN) is the most common glomerulonephritis worldwide, but its etiologic mechanisms are still poorly understood. Different prevalences among ethnic groups and familial aggregation, together with an increased familial risk, suggest important genetic influences on its pathogenesis. A locus for familial IgAN, called "IGAN1," on chromosome 6q22-23 has been described, without the identification of any responsible gene. The partners of the European IgAN Consortium organized a second genomewide scan in 22 new informative Italian multiplex families. A total of 186 subjects (59 affected and 127 unaffected) were genotyped and were included in a two-stage genomewide linkage analysis. The regions 4q26-31 and 17q12-22 exhibited the strongest evidence of linkage by nonparametric analysis (best P=.0025 and .0045, respectively). These localizations were also supported by multipoint parametric analysis, in which peak LOD scores of 1.83 ( alpha =0.50) and 2.56 ( alpha =0.65) were obtained using the affected-only dominant model, and by allowance for the presence of genetic heterogeneity. Our results provide further evidence for genetic heterogeneity among families with IgAN. Evidence of linkage to multiple chromosomal regions is consistent with both an oligo/polygenic and a multiple-susceptibility-gene model for familial IgAN, with small or moderate effects in determining the pathological phenotype. Although we identified new candidate regions, replication studies are required to confirm the genetic contribution to familial IgAN.     

Diagnosing Severe Falciparum Malaria in Parasitaemic African Children: A Prospective Evaluation of Plasma PfHRP2 Measurement

Background

In African children, distinguishing severe falciparum malaria from other severe febrile illnesses with coincidental Plasmodium falciparum parasitaemia is a major challenge. P. falciparum histidine-rich protein 2 (PfHRP2) is released by mature sequestered parasites and can be used to estimate the total parasite burden. We investigated the prognostic significance of plasma PfHRP2 and used it to estimate the malaria-attributable fraction in African children diagnosed with severe malaria.

Methods and Findings

Admission plasma PfHRP2 was measured prospectively in African children (from Mozambique, The Gambia, Kenya, Tanzania, Uganda, Rwanda, and the Democratic Republic of the Congo) aged 1 month to 15 years with severe febrile illness and a positive P. falciparum lactate dehydrogenase (pLDH)-based rapid test in a clinical trial comparing parenteral artesunate versus quinine (the AQUAMAT trial, ISRCTN 50258054). In 3,826 severely ill children, Plasmadium falciparum PfHRP2 was higher in patients with coma (p = 0.0209), acidosis (p<0.0001), and severe anaemia (p<0.0001). Admission geometric mean (95%CI) plasma PfHRP2 was 1,611 (1,350–1,922) ng/mL in fatal cases (n = 381) versus 1,046 (991–1,104) ng/mL in survivors (n = 3,445, p<0.0001), without differences in parasitaemia as assessed by microscopy. There was a U-shaped association between log₁₀ plasma PfHRP2 and risk of death. Mortality increased 20% per log₁₀ increase in PfHRP2 above 174 ng/mL (adjusted odds ratio [AOR] 1.21, 95%CI 1.05–1.39, p = 0.009). A mechanistic model assuming a PfHRP2-independent risk of death in non-malaria illness closely fitted the observed data and showed malaria-attributable mortality less than 50% with plasma PfHRP2≤174 ng/mL. The odds ratio (OR) for death in artesunate versus quinine-treated patients was 0.61 (95%CI 0.44–0.83, p = 0.0018) in the highest PfHRP2 tertile, whereas there was no difference in the lowest tertile (OR 1.05; 95%CI 0.69–1.61; p = 0.82). A limitation of the study is that some conclusions are drawn from a mechanistic model, which is inherently dependent on certain assumptions. However, a sensitivity analysis of the model indicated that the results were robust to a plausible range of parameter estimates. Further studies are needed to validate our findings.

Conclusions

Plasma PfHRP2 has prognostic significance in African children with severe falciparum malaria and provides a tool to stratify the risk of “true” severe malaria-attributable disease as opposed to other severe illnesses in parasitaemic African children. Please see later in the article for the Editors'' Summary.     

Population dynamics of Triatoma vitticeps (Stål, 1859) in Itanhomi, Minas Gerais, Brazil

Taxonomic markers (head structure morphometry, isoenzymes and randon amplified polymorphism of DNA - RAPD) were used to understand the population dynamics of Triatoma vitticeps, predominant triatomine species in Itanhomi district, using samples obtained from domestic, peridomiciliary and sylvatic habitats. Morphometric analysis revealed sexual dimorphism within the three samples although specimens could not be separated according to the habitat in which they were captured. Forty-two bands were analyzed from RAPD profiles generated using four primers. A dendrogram constructed from Dice's similarity coefficient values showed that migration of the insects between the habitats has occurred, without structuring of populations. Moreover, the dendrogram obtained from the genetic distance values showed an important gene flow between the sylvatic and domestic habitats. No polymorphism was found in the electrophoretic mobility of proteins for the ten enzymes studied. Our results revealed movement of triatomines between the three habitats, suggesting that the presence of T. vitticeps in houses should not be ignored. As invasion of houses by sylvatic insects is frequent and the natural infection indices of this species are among the highest known, epidemiological vigilance studies may reveal possible changes in T. vitticeps behaviour which could present future risks to public health.     

Molecular characterisation of two novel starch granule proteins 1 in wild and cultivated diploid A genome wheat species

Starch synthase IIa, also known as starch granule protein 1 (SGP-1), plays a key role in amylopectin biosynthesis. The absence of SGP-1 in cereal grains is correlated to dramatic changes in the grains’ starch content, structure, and composition. An extensive investigation of starch granule proteins in this study revealed a polymorphism in the electrophoretic mobility of SGP-1 between two species of wheat, Triticum urartu and T. monococcum; this protein was, however, conserved among all other Triticum species that share the A genome inherited from their progenitor T. urartu. Two different electrophoretic profiles were identified: SGP-A1 proteins of T. urartu accessions had a SDS–PAGE mobility similar to those of tetraploid and hexaploid wheat species; conversely, SGP-A1 proteins of T. monococcum ssp. monococcum and ssp. boeoticum accessions showed a different electrophoretic mobility. The entire coding region of the two genes was isolated and sequenced in an attempt to explain the polymorphism identified. Several single nucleotide polymorphisms (SNPs) responsible for amino acid changes were identified, but no indel polymorphism was observed to explain the difference in electrophoretic mobility. Amylose content did not differ significantly among T. urartu, T. monococcum ssp. boeoticum and T. monococcum ssp. monococcum, except in one accession of the ssp. boeoticum. Conversely, several interspecific differences were observed in viscosity properties (investigated as viscosity profiles using a rapid visco analyzer—RVA profiles) of these cereal grains. T. monococcum ssp. boeoticum accessions had the lowest RVA profiles, T. urartu accessions had an intermediate RVA profile, whereas T. monococcum ssp. monococcum showed the highest RVA profile. These differences could be associated with the numerous amino acid and structural changes evident among the SGP-1 proteins.