Processing of seminal plasma hCAP-18 to ALL-38 by gastricsin: a novel mechanism of generating antimicrobial peptides in vagina

The human cathelicidin, hCAP-18, is expressed both in neutrophils and in epithelial cells. hCAP-18 is processed to the antimicrobial peptide LL-37 by proteinase 3 in neutrophils. hCAP-18 is highly expressed in the epididymis with a subsequent high concentration in seminal plasma where the protein is present in its unprocessed and antimicrobially inactive form. We report here that hCAP-18 in seminal plasma is processed to generate a 38-amino acid antimicrobial peptide ALL-38 by the prostate-derived protease gastricsin when incubated at a pH corresponding to the vaginal pH. In accordance with this, seminal plasma derived hCAP-18 was found in its processed form in the vagina following sexual intercourse. The antimicrobial activity of ALL-38 against a variety of microorganisms tested is equal to that of LL-37. This enzymatic activation of a proantimicrobial substance in seminal plasma following exposure to the vaginal milieu represents a novel mechanism to prevent infection following sexual intercourse.     

Misfolding, degradation, and aggregation of variant proteins. The molecular pathogenesis of short chain acyl-CoA dehydrogenase (SCAD) deficiency

Short chain acyl-CoA dehydrogenase (SCAD) deficiency is an inborn error of the mitochondrial fatty acid metabolism caused by rare variations as well as common susceptibility variations in the SCAD gene. Earlier studies have shown that a common variant SCAD protein (R147W) was impaired in folding, and preliminary experiments suggested that the variant protein displayed prolonged association with chaperonins and delayed formation of active enzyme. Accordingly, the molecular pathogenesis of SCAD deficiency may rely on intramitochondrial protein quality control mechanisms, including degradation and aggregation of variant SCAD proteins. In this study we investigated the processing of a set of disease-causing variant SCAD proteins (R22W, G68C, W153R, R359C, and Q341H) and two common variant proteins (R147W and G185S) that lead to reduced SCAD activity. All SCAD proteins, including the wild type, associate with mitochondrial hsp60 chaperonins; however, the variant SCAD proteins remained associated with hsp60 for prolonged periods of time. Biogenesis experiments at two temperatures revealed that some of the variant proteins (R22W, G68C, W153R, and R359C) caused severe misfolding, whereas others (R147W, G185S, and Q341H) exhibited a less severe temperature-sensitive folding defect. Based on the magnitude of in vitro defects, these SCAD proteins are characterized as folding-defective variants and mild folding variants, respectively. Pulse-chase experiments demonstrated that the variant SCAD proteins either triggered proteolytic degradation by mitochondrial proteases or, especially at elevated temperature, aggregation of non-native conformers. The latter finding may indicate that accumulation of aggregated SCAD proteins may play a role in the pathogenesis of SCAD deficiency.     

The strength-dexterity test as a measure of dynamic pinch performance

We have developed a method to quantify the dynamic interaction between fingertip force magnitude (strength) and directional control (dexterity) during pinch with a novel strength-dexterity (S-D) test based on the principle of buckling of compression springs. The test consists of asking participants to use key and opposition pinch to attempt to fully compress springs, in random order, with a wide range of combinations of strength and dexterity requirements. The minimum force required to fully compress the spring and the propensity of the spring to buckle define the strength and dexterity requirements, respectively. The S-D score for each pinch style was the sum of the strength values of all springs successfully compressed fully. We tested 3 participant groups: 18 unimpaired young adults (40yr), and 14 adults diagnosed with carpo-metacarpal osteoarthritis (CMC OA) (>or = 36yr). We investigated the repeatability of the S-D test with 74 springs by testing 14 young adults twice on different days. The per-spring repeatability across subjects was >or = 94%. A minimum performance score for young adults was found as they all could compress a subset of 39 springs. Using this subset of springs, we compared the ability of the S-D score vs. maximal pinch force values to distinguish unimpaired hands from those with CMC OA of the thumb. The score for this 39-spring S-D test distinguished between CMC OA and asymptomatic older adults, whereas pinch meter readings did not (p<0.05). We conclude that the S-D test is repeatable and applicable to clinical research. We propose including the S-D test in studies aiming to quantify impairment and compare treatment outcomes in orthopaedic and neurological afflictions that degrade dynamic manipulation.     

Distribution patterns of postmortem damage in human mitochondrial DNA

The distribution of postmortem damage in mitochondrial DNA retrieved from 37 ancient human DNA samples was analyzed by cloning and was compared with a selection of published animal data. A relative rate of damage (rho(v)) was calculated for nucleotide positions within the human hypervariable region 1 (HVR1) and cytochrome oxidase subunit III genes. A comparison of damaged sites within and between the regions reveals that damage hotspots exist and that, in the HVR1, these correlate with sites known to have high in vivo mutation rates. Conversely, HVR1 subregions with known structural function, such as MT5, have lower in vivo mutation rates and lower postmortem-damage rates. The postmortem data also identify a possible functional subregion of the HVR1, termed "low-diversity 1," through the lack of sequence damage. The amount of postmortem damage observed in mitochondrial coding regions was significantly lower than in the HVR1, and, although hotspots were noted, these did not correlate with codon position. Finally, a simple method for the identification of incorrect archaeological haplogroup designations is introduced, on the basis of the observed spectrum of postmortem damage.     

Guidelines for consistent reporting of exchanges/to nature within life cycle inventories (LCI)

Data availability and data quality are still critical factors for successful LCA work. The SETAC-Europe LCA Working Group ‘Data Availability and Data Quality’ has therefore focused on ongoing developments toward a common data exchange format, public databases and accepted quality measures to find science-based solutions than can be widely accepted. A necessary prerequisite for the free flow and exchange of life cycle inventory (LCI) data and the comparability of LCIs is the consistent definition, nomenclature, and use of inventory parameters. This is the main subject of the subgroup ‘Recommended List of Exchanges’ that presents its results and findings here:

Benzyl-functionalized cycloSal-d4T monophosphates

Synthetic routes to benzyl-functionalized cycloSal-d4T monophosphates (7CH2X-cycloSal-d4TMP) have been developed. Their hydrolytic behavior in basic aqueous solution (pH = 7.3) was studied and their hydrolysis half-lives were determined. It turned out that two different degradation pathways are leading to different products: beside the formation of the expected d4TMP and a styrene type derivative, a phenyl-d4T-phosphodiester was obtained as well. The product distribution was specified.     

Determinants of miniprotein stability: can anything replace a buried H-bonded Trp sidechain?

A novel 20-residue fold, designated the `Trp-cage' motif, hasbeen shown to be 98+% folded in both water and 30 vol-%trifluoroethanol solution. Folding is cooperative andhydrophobically driven, resulting in the burial of the Trpsidechain and a stable H-bond from the Trp-NH to a sequenceremote backbone carbonyl. In the present study the effects ofreplacing the Trp with His, Phe and both isomers of -naphthylalanine are examined. The results suggest that thehydrophobic cluster is a specific interaction of proline ringswith the indole ring which can be partially mimicked by anaphthalene ring. The His and Phe mutants are completelyunfolded in aqueous medium. The naphthylalanine mutants forma stable hydrophobic cluster in 30% trifluoroethanol, but areless stable in water than the native structure.     

Effects of sodium intake on cardiovascular variables in humans during posture changes and ambulatory conditions

The hypothesis was tested that cardiac output (CO) and stroke volume (SV) are increased by a moderate physiological elevation in sodium intake with a more pronounced effect in the ambulatory upright seated than supine position. Fourteen healthy males were investigated during ambulatory and controlled laboratory conditions at the end of two consecutive 5-day periods with sodium intakes of 70 (low) and 250 (high) mmol/24 h or vice versa, respectively. Comparing high and low sodium intake, plasma volume and plasma protein concentrations were 9 and 8% higher in the seated and the supine position, respectively. When seated during laboratory conditions, CO was 5.3 +/- 0.2 l/min on the high sodium intake vs. 4.8 +/- 0.2 l/min on the low (P < 0.05), and SV was 81 +/- 3 vs. 68 +/- 3 ml (P < 0.05). In the supine position, SV was 107 +/- 3 ml on the high vs. 99 +/- 3 ml (P < 0.05) on the low sodium intake, while CO remained unchanged. The difference in CO and SV induced by the change in sodium intake was significantly higher in the seated than in the supine position (P < 0.05). During upright ambulatory conditions, CO was 5.9 +/- 0.2 l/min during the high and 5.2 +/- 0.2 l/min during the low sodium intake (P < 0.05), and SV was 84 +/- 3 and 69 +/- 3 ml (P < 0.05), respectively. Mean arterial pressure was unchanged by the variations in sodium intake. In conclusion, increments in sodium intake within the normal physiological range increase CO and SV and more so in the seated vs. the supine position. These changes are readily detectable during upright, ambulatory conditions. The results indicate that the higher SV and CO could constitute an arterial baroreflex stimulus for the augmented renal sodium excretion.