Karina H. M. Cardozo

Palythine-threonine, a major novel mycosporine-like amino acid (MAA) isolated from the hermatypic coral Pocillopora capitata.

Using a high-resolution reverse-phase liquid chromatography method we found that the tissues of the hermatypic coral Pocillopora capitata (collected in Santiago Bay, Mexico) contain a high diversity of primary and secondary mycosporine-like amino acids (MAAs) typical of some reef-building coral species: mycosporine-glycine, shinorine, porphyra-334, mycosporine-methylamine-serine, mycosporine-methylamine-threonine, palythine-serine, palythine and one additional novel predominant MAA, with an absorbance maximum of 320 nm. Here we document the isolation and characterization of this novel MAA from the coral P. capitata. Using low multi-stage mass analyses of deuterated and non deuterated compounds, high-resolution mass analyses (Time of Flight, TOF) and other techniques, this novel compound was characterized as palythine-threonine. Palythine-threonine was also present in high concentrations in the corals Pocillopora eydouxi and Stylophora pistillata indicating a wider distribution of this MAA among reef-building corals. From structural considerations we suggest that palythine-threonine is formed by decarboxylation of porphyra-334 followed by demethylation of mycosporine-methylamine-threonine.

Rhythmicity and oxidative/nitrosative stress in algae

We review here the evidence linking molecular control of the biological clocks to the cellular toxicity and the generation of ROS/RNS (reactive oxygen species/reactive nitrogen species) in algae. A discussion is also made of the possible relevant relationships between the rhythmicity of photosynthetic activity (particularly insofar as it concerns the circadian fluctuations of light-absorbing pigments and chlorophyll a/b binding proteins), nitrate reductase (a potential .NO source in algae and higher plants under specific circumstances) and major antioxidant enzyme activities, aiming to gain a better understanding of the oscillatory levels of oxidative/nitrosative modifications in algal cells. A comparison is also made of the biosynthesis of low molecular weight antioxidants such as carotenoids, melatonin, reduced gluthatione, mycosporine-like amino acids and ROS targets, such as polyunsaturated fatty acids, and the biological clocks and oxidative stress.

Daily Oscillation of Fatty Acids and Malondialdehyde in the Dinoflagellate Lingulodinium polyedrum

The levels of the fatty acids, cis eicosahexenoic acid and cis linolenic acid, as well as the extent of lipoperoxidation, measured as malondialdehyde (MDA), were analyzed in the photosynthetic marine dinoflagellate Lingulodinium polyedrum at different times during the light : dark (L : D) cycle. Levels of MDA were twice as high during the day phase than during the night phase. This may be related to the circadian rhythm in photosynthesis as during photosynthetic electron flux, electrons can leak and react with molecular oxygen producing reactive oxygen species (ROS) which in turn react with lipids, proteins, and DNA among other biomolecules. Fatty acid levels were highest during the day phase. Our findings indicate that unsaturated fatty acids are more susceptible to attack and degradation when L. polyedrum is exposed to light and that the cells compensate for this by an increased fatty acid content during the day. Excessive lipoperoxidation during the light phase could result in a higher level of chloroplast or plasma membrane disruption leading to cell death.

Unraveling the sperm proteome and post-genomic pathways associated with sperm nuclear DNA fragmentation

PurposeSperm DNA fragmentation has been suggested as a marker for infertility diagnosis and prognosis. Hence, understanding its impact on male physiology and post-genomic pathways would be clinically important. We performed the proteomics and functional enrichment analyses of viable spermatozoa from ejaculates with low and high sperm DNA fragmentation to identify protein expression and pathways altered in association with sperm DNA fragmentation.MethodsSperm DNA fragmentation using the Comet assay and the Komet 6.0.1 software was assessed in raw samples from 89 subjects from a human reproduction service. The Low and High sperm DNA fragmentation groups were formed according to the Olive Tail Moment variable. Spermatozoa proteins from these groups were pooled and analyzed by a shotgun proteomic approach (2D nanoUPLC-ESI-MSE). Differentially expressed proteins were used for a functional enrichment study.ResultsTwo hundred and fifty-seven proteins were identified or quantified in sperm from the Low and High sperm DNA fragmentation groups. Of these, seventy-one proteins were exclusively or overexpressed in the Low group, whereas twenty-three proteins were exclusively or overexpressed in the High group. One hundred and sixty-three proteins were conserved between these groups. We also functionally related the differentially expressed proteins in viable spermatozoa from the groups. Processes such as triacylglycerol metabolism, energy production, protein folding, response to unfolded proteins, and cellular detoxification were found to be altered in these cells.ConclusionsSperm DNA fragmentation is associated with differential protein expression in viable spermatozoa. These proteins may potentially be used as biomarkers for sperm DNA integrity.

Analyses of photoprotective compounds in red algae from the Brazilian coast

Qualitative and quantitative studies of mycosporine-like amino acids (MAAs) in three species of the genus Gracilaria Greville (G. birdiae, G. domingensis and G. tenuistipitata) were performed. A simple and efficient extraction procedure based on ethanol was described. HPLC, UV and mass spectrometry experiments revealed different profiles between extracts obtained from one species cultivated in the laboratory (G. tenuistipitata) and two species collected in their natural environment (G. birdiae and G. domingensis). The levels detected in the latter two species were approximately 150 times higher than in the species cultivated in vitro. This study revealed that G. birdiae and G. domingensis present a potential source for economical exploration of MAAs.

Analysis of the functional aspects and seminal plasma proteomic profile of sperm from smokers

To evaluate the effect of smoking on sperm functional quality and seminal plasma proteomic profile.

Comparison of diode array and electrochemical detection in the C30 reverse phase HPLC analysis of algae carotenoids

Qualitative and quantitative determination of carotenoids pigments can provide valuable information about the organisms in which this important class of compounds is found. In the HPLC analysis of pigments, diode array (DAD), electrochemical (ED) and other kinds of detector may be used. The aim of this work is to develop an HPLC method using a C30 column to identify and quantify sixteen different pigments from algae. A further aim is to compare precision and accuracy obtained by DAD and ED. ED is normally more sensible than DAD. On the other hand, the highest precision and accuracy was obtained with DAD. In conclusion, the method was efficient for quantitative and qualitative analyses of pigments from cyanobacteria and different microalgae classes. Their pigment patterns for several organisms are also discussed.

Sperm nuclear DNA fragmentation rate is associated with differential protein expression and enriched functions in human seminal plasma.

To analyse the proteomic profile of seminal plasma with the aim of identifying the proteins and post‐genomic pathways associated with sperm DNA fragmentation.

Follicular fluid alterations in endometriosis: label-free proteomics by MSE as a functional tool for endometriosis

Abstract Endometriosis is a chronic gynecological condition that affects 10-32% of women of reproductive age and may lead to infertility. The study of protein profiles in follicular fluid may assist in elucidating possible biomarkers related to this disease. For this, follicular fluid samples were obtained from women with tubal factor or minimal male factor infertility who had pregnancy outcomes after in vitro fertilization (IVF) treatment (control group, nu2009=u200910), women with endometriosis (endometriosis group, nu2009=u200910), along with the endometrioma from these same patients were included (endometrioma group, nu2009=u200910). For proteomic analysis, samples were pooled according to their respective groups and normalized to protein content. Proteins were analyzed by in tandem mass spectrometry (MSE) Spectra processing and the ProteinLynx Global Server v.2.5. was used for database searching. Data was submitted to the biological network analysis using Cytoscape 2.8.2 with ClueGO plugin. As a result, 535 proteins were identified among all groups. The control group differentially or uniquely expressed 33 (6%) proteins and equal expression of 98 (18%) proteins was observed in the control and endometriosis groups of which 41 (7%) proteins were further identified and/or quantified. Six (1%) proteins were observed in both the endometriosis and endometrioma groups, but 212 (39%) proteins were exclusively identified and/or quantified in the endometrioma group. There were 9 (1%) proteins observed in both the control and endometrioma groups and there were 139 (25%) proteins common among all three groups. Distinct differences among the protein profiles in the follicular fluid of patients included in this study were found, identifying proteins related to the disease progression and IVF success. Thus, some pathways related to endometriosis are associated with the presence of specific proteins, as well as the absence of others. This study provides a first step to the development of more sensitive diagnostic tests and treatment.

A Fragmentation study of di-acidic mycosporine-like amino acids in electrospray and nanospray mass spectrometry

Two mycosporine (MAAs), containing an extra acid function, were analyzed by nanospray and electrospray ionization tandem mass spectrometry. In contrast to the previous studies it is demonstrated that no significant characteristic methyl radical loss occurred in positive mode. The fragmentation pathway in negative mode was also proposed in this work, along with theoretical calculations to characterize the site of protonation.