Scedosporium Cell Wall: From Carbohydrate-Containing Structures to Host–Pathogen Interactions

Scedosporium species are filamentous fungi usually found in sewage and soil from human-impacted areas. They cause a wide range of diseases in humans, from superficial infections, such as mycetoma, to invasive and disseminated cases, especially associated in immunocompromised patients. Scedosporium species are also related to lung colonization in individuals presenting cystic fibrosis and are considered one of the most frequent fungal pathogens associated to this pathology. Scedosporium cell wall contains glycosylated molecules involved in important biological events related to virulence and pathogenicity and represents a significant source of antigens. Polysaccharides, peptidopolysaccharides, O-linked oligosaccharides and glycosphingolipids have been identified on the Scedosporium surface. Their primary structures were determined based on a combination of techniques including gas chromatography, ESI-MS, and ¹H and ¹³C nuclear magnetic resonance. Peptidorhamnnomannans are common cell wall components among Scedosporium species. Comparing different species, minor structural differences in the carbohydrate portions were detected which could be useful to understand variations in virulence observed among the species. N- and O-linked peptidorhamnomannans are major pathogen-associated molecular patterns and, along with α-glucans, play important roles in triggering host innate immunity. Glycosphingolipids, such as glucosylceramides, have highly conserved structures in Scedosporium species and are crucial for fungal growth and virulence. The present review presents current knowledge on structural and functional aspects of Scedosporium glycoconjugates that are relevant for understanding pathogenicity mechanisms and could contribute to the design of new agents capable of inhibiting growth and differentiation of Scedosporium species. Other cell components such as melanin and ectophosphatases will be also included.

     

Hyper response to ovarian stimulation affects the follicular fluid metabolomic profile of women undergoing IVF similarly to polycystic ovary syndrome

Introduction

During in vitro fertilization (IVF), the hyper response to controlled ovarian stimulation (COS) is a common characteristic among patients diagnosed with polycystic ovary syndrome (PCOS), although non-diagnosed patients may also demonstrate this response.

Objectives

In an effort to investigate follicular metabolic characteristics associated with hyper response to COS, the present study analyzed follicular fluid (FF) samples from patients undergoing IVF.

Methods

FF samples were obtained from patients with PCOS and hyper response during IVF (PCOS group, N?=?15), patients without PCOS but with hyper response during IVF (HR group, N?=?44), and normo-responder patients receiving IVF (control group, N?=?22). FF samples underwent Bligh and Dyer extraction, followed by metabolomic analysis by ultra-performance liquid chromatography mass spectrometry, considering two technical replicates. Clinical data was analyzed by ANOVA and chi-square tests. The metabolomic dataset was analyzed by multivariate statistics, and the significance of biomarkers was confirmed by ANOVA.

Results

Clinical data showed differences regarding follicles production, oocyte and embryo quality. From the 15 proposed biomarkers, 14 were of increased abundance in the control group and attributed as fatty acids, diacylglycerol, triacylglycerol, ceramide, ceramide-phosphate, phosphatidylcholine, and sphingomyelin. The PCOS patients showed increased abundance of a metabolite of m/z 144.0023 that was not attributed to a class.

Conclusion

The clinical and metabolic similarities observed in the FF of hyper responders with and without PCOS diagnosis indicate common biomarkers that could assist on the development of accessory tools for assessment of IVF parameters.

     

Follicular fluid lipidomics reveals lipid alterations by LH addition during IVF cycles

Introduction

Ovulation induction protocols are key components for performing assisted reproduction treatments successfully. The importance of adding exogenous LH to the controlled ovarian stimulation protocols in young women is still a matter of discussion in the clinical practice.

Objective

To estimate how LH addition to controlled ovarian stimulation protocols may affect the follicular fluid lipid profile of women undergoing in vitro fertilization treatment.

Methods

We conducted the study using 28 self-paired samples, 14 per group. The patients received FSH during their first cycle of ovarian stimulation (FSH group). If the treatment did not result in pregnancy, the same patients returned for a new cycle and received stimulus with the addition of LH to the previous protocol (Low-dose-LH group). Lipidomics analysis was performed by UPLC-MS^E mass spectrometry. The software Progenesis QI was used to identify potential lipid biomarkers. Statistical analysis was performed using the SPSS 18.0 and MetaboAnalyst 2.0 software.

Results

The analysis of clinical data showed no statistically significant differences between groups, in contrast to lipidomic analysis. Concerning lipidomic profile, the lipids differentially expressed in FSH group belong to the following subclasses:triacylglycerols; branched fatty acids and diacylglycerophosphoethanolamines; while in Low-dose-LH group the subclasses are gangliosides; acylglycerophosphoethanolamines; triacylglycerols; acylglycerophosphoserines; GalNAcβ1-3Galα1-4Galβ1-4Glc-(Globo series); amino fatty acids; triacylglycerols and prostaglandins.

Conclusion

The differences found between the groups may contribute to the establishment of potential therapeutical targets based on LH-associated lipid biomarkers aiming to individualize treatments and obtain reproductive success.