Marla Sokolowski: and now for someone completely different

A comprehensive science, technology, engineering, and mathematics (STEM) education has persistent formative effects on individuals, communities, and society. In this regard, Marla Sokolowski’s academic legacy will forever reflect her unique contributions to STEM education and mentoring. Furthermore, her creative and multidisciplinary approach to research has resulted in groundbreaking advances in our understanding of behavior genetics. Illustrated here are a few of our life-long learning experiences drawn mainly from earlier parts of Marla’s careerinfo:eu-repo/semantics/publishedVersio

Rye Bs disclose ancestral sequences in cereal genomes with a potential role in gametophyte chromatid segregation

Research ArticleTwo sequence families, E3900 and D1100, are amplified on the subtelomeric domain of the long arm of rye B chromosomes, the region that controls its drive mechanism. In this work, polymerase chain reaction (PCR) with a number of primers spanning E3900 shows that the organization and nucleotide sequence of E3900-related portions are present and highly conserved on rye A chromosomes as well as in other cereals. Quantitative Real-Time PCR estimates two E3900 sequences to be represented in 100–150 copies on Bs and at least as single copies on As. A novel E3900- related sequence, with a deletion that results in a frameshift and subsequently an open reading frame with putative DNA binding motifs, is identified. Expression analysis of E3900 indicates identical transcription levels in leaves from plants with and without Bs, showing that the expression of these sequences must be silenced on Bs and tightly regulated on As in leaves. In contrast, E3900 transcription is upregulated during meiosis exclusively in plants with Bs, maintaining a high level of transcription in the gametophyte. Interestingly, Bs not only influence their own chromatid segregation but also that of the regular chromosome complement of both rye and wheat. There is a drastic increase in frequency of disrupted metaphase and anaphase cells in the first mitosis of pollen grains carrying Bs, which appears to be due to anomalous adherences between sister chromatids. Taken together, this work provides insight into how E3900 sequences are potentially associated with important evolutionary mechanisms involved in basic cellular processes

Exploring a novel effect of lactoferrin on the plasma membrane towards the elucidation of the mechanisms of action: from yeast to human cells

Microbiotec'17 - Congress of Microbiology and Biotechnology 2017info:eu-repo/semantics/publishedVersio

Production of iron-peptide complexes from spent yeast for nutraceutical industry

Iron (Fe) deficiencies are a major health condition concern and over the years many solutions in the form of Fe supplementation have been investigated. Organic Fe-complexes are the most promising for Fe deficiencies remediation. The aim of present study was to value peptide rich waste streams from β-glucan and mannan production from spent yeast (Gpep and Mpep, respectively) as Fe-peptide complexes for Fe supplementation. These waste streams were first subjected to ultrafiltration treatment before assessing the capacity of these fractions to complex Fe was evaluated, without, and with nitrogen. Results have shown that Gpep> 1 kDa was the best fraction with a optimal pH of 6.0 and a time of 30 min. The resulting Fe-peptide complex was characterized using powder XDR, fluorescence, FTIR, SEM and Mastersizer Laser Diffraction. Results have shown that Gpep and Mpep waste streams have potential application as Fe supplementation in the form of Fe peptide complexes.info:eu-repo/semantics/publishedVersio

Bisphenol A alters transcript levels of biomarker genes for major depressive disorder

Major depressive disorder is a moderately heritable disorder characterized by one or more major depressive episodes. Laboratory tests to suport MDD diagnosis are not available. Diagnosis and treatment are based on various signs and symptoms not always fitting into strict diagnostic categories. Research for biological markers of neuropsychiatric disorders has been a challenge

Effect of mannan oligosaccharides extracts in uropathogenic escherichia coli adhesion in human bladder cells

Urinary tract infections (UTIs) are a common public health problem, mainly caused by uropathogenic Escherichia coli (UPEC). Patients with chronic UTIs are usually treated with long-acting prophylactic antibiotics, which promotes the development of antibiotic-resistant UPEC strains and may complicate their long-term management. D-mannose and extracts rich in D-mannose such as mannan oligosaccharides (MOS; D-mannose oligomers) are promising alternatives to antibiotic prophylaxis due to their ability to inhibit bacterial adhesion to urothelial cells and, therefore, infection. This highlights the therapeutic potential and commercial value of using them as health supplements. Studies on the effect of MOS in UTIs are, however, scarce. Aiming to evaluate the potential benefits of using MOS extracts in UTIs prophylaxis, their ability to inhibit the adhesion of UPEC to urothelial cells and its mechanism of action were assessed. Additionally, the expression levels of the pro-inflammatory marker interleukin 6 (IL-6) were also evaluated. After characterizing their cytotoxic profiles, the preliminary results indicated that MOS extracts have potential to be used for the handling of UTIs and demonstrated that the mechanism through which they inhibit bacterial adhesion is through the competitive inhibition of FimH adhesins through the action of mannose, validated by a bacterial growth impact assessment.info:eu-repo/semantics/publishedVersio

The effects of field inoculation of arbuscular mycorrhizal fungi through rye donor plants on grapevine performance and soil properties

Grapevines are highly dependent on arbuscular mycorrhizal fungi (AMF) for normal growth and development. However, vineyard soils may have low AMF abundance and diversity due to conventional soil management practices that are detrimental for these fungi. In this context, the establishment of AMF-inoculated cover crops can be a highly convenient strategy to reestablish soil mycorrhizal potential, as it combines the advantages of a vigorous inoculum source coming from mycorrhizal donor plants with the overall benefits of green covers for grape quality, microbial diversity and soil health. In this work, the potential benefits of Funneliformis mosseae-inoculated under-vine cover crops on grapevine growth, physiology and production were compared to those derived from 1) the establishment of non-inoculated under-vine cover crops, and 2) conventional herbicide-based weed control in the under-vine space. In addition, grapevine root AMF community composition was analyzed to assess if the introduction of a non-native AMF species induced changes on resident mycorrhizal community assemblies and to unveil potential variations in AMF diversity associated to herbicide replacement by green covers. Results indicated that under-vine cover crops, inoculated or not, led to a general vigor decrease in grapevines, probably due to competition between the two species. However, after a heat wave that occurred at harvest time in the second year of the experiment, grapevines growing in plots with inoculated cover crops had the highest photochemical reflectance indices and net photosynthesis rates, and partially compensated production losses due to berry sunburn. Root mycorrhizal community analysis by the end of the experiment revealed that the inoculated F. mosseae isolate colonized grapevine roots from inoculated plots, while it was absent in the other ones. Moreover, inoculation of this AMF did not lead to a replacement of native root AMF communities, but allowed further colonization by other resident Glomeraceae and non-Glomeraceae AMF taxa. Overall, the work herein demonstrates that the introduction of F. mosseae through donor plants is a suitable field inoculation method for grapevines and can help them to better withstand heat wavesinfo:eu-repo/semantics/submittedVersio

Iron-peptide complexes from spent yeast: evaluation of iron absorption using a Caco-2 monolayer

Anaemia is one of the most prevalent nutritional diseases worldwide with Fe deficiency being its major cause. In fact, the limited bioavailability of dietary iron and its interaction with food compounds contribute to its poor absorption in the human body and dietary Fe supplementation has been widely used to address this issue. By incorporating a circular economy framework, this study takes a novel approach of production of iron-peptide complexes from spent yeast peptide-rich extracts as a more effective substitute to conventional salt-based iron supplements, which are related with adverse consequences. Considering the regulation of iron absorption on duodenal enterocytes, iron-peptides complexes absorption was assessed using a Caco-2 monolayer, evaluating both iron uptake and the capacity to stimulate ferritin synthesis, after their in vitro simulated gastrointestinal digestion following INFOGEST protocol. An iron salt and a commercially available benchmark (iron bisglycinate) were also included in this study to compare the absorption performance. Results showed that iron-peptide complexes exhibited a similar behaviour (no statistically significant alterations (p > 0.05)) concerning the other tested samples, thus being a promising alternative for iron dietary supplementation. The remaining digested peptides from the complexes also showed potential antioxidant activity, suggesting protection of iron from oxidation within human body.info:eu-repo/semantics/publishedVersio

Lactoferrin perturbs lipid rafts and requires integrity of Pma1p-lipid rafts association to exert its antifungal activity against Saccharomyces cerevisiae

"Available online 07 January 2021"Lactoferrin (Lf) is a bioactive milk-derived protein with remarkable wide-spectrum antifungal activity. To deepen our understanding of the molecular mechanisms underlying Lf cytotoxicity, the role of plasma membrane ergosterol- and sphingolipid-rich lipid rafts and their association with the proton pump Pma1p was explored. Pma1p was previously identified as a Lf-binding protein. Results showed that bovine Lf (bLf) perturbs sterol-rich lipid rafts organization by inducing intracellular accumulation of ergosterol. Using yeast mutant strains lacking lipid rafts-associated proteins or enzymes involved in the synthesis of ergosterol and sphingolipids, we found that perturbations in the composition of these membrane domains increase resistance to bLf-induced yeast cell death. Also, when Pma1p-lipid rafts association is compromised in the Pma110 mutant and in the absence of the Pma1p-binding protein Ast1p, the bLf killing activity is impaired. Altogether, results showed that the perturbation of lipid rafts and the inhibition of both Pma1p and V-ATPase activities mediate the antifungal activity of bLf. Since it is suggested that the combination of conventional antifungals with lipid rafts-disrupting compounds is a powerful antifungal approach, our data will help to pave the way for the use of bLf alone or in combination for the treatment/eradication of clinically and agronomically relevant yeast pathogens/fungi.This work was supported by national funds through the Portuguese Foundation for Science and Technology (FCT I.P.) under the scope of the strategic funding of “Contrato-Programa” UIDB/04050/2020 and UIDB/ 04469/2020 unit; by the BioTecNorte operation (NORTE-01-0145- FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte; and by the Servicio para el Control de la Esterilización, Laboratorio de Microbiología Oral (CN-16-036). Cátia Santos-Pereira acknowledges the PhD fellowship PD/BD/128032/2016 funded by FCT under the scope of the doctoral programme in Applied and Environmental Microbiology (DP_AEM).info:eu-repo/semantics/publishedVersio

Deciphering the mechanisms underlying bovine milk lactoferrin anticancer activity using yeast and cancer cell lines as complementary models

Lactoferrin (Lf) is a milk derived iron-binding protein that exhibits a broad range of interesting biological activities, from which its anticancer and antifungal activities stand out. Our group has been elucidating the mechanisms and identifying the molecular targets underlying Lf anticancer/antifungal activities in order to improve its therapeutic efficacy and rational application. Indeed, we previously demonstrated that Lf triggers a mitochondrial and caspase-dependent regulated cell death in Saccharomyces cerevisiae (1). Moreover, we found that Lf selectively induces apoptosis in highly metastatic cell lines displaying the proton pump V-ATPase at the plasma membrane (2). However, much work is needed to further characterize Lf mechanisms of action. In the present work, we show how functional genomic approaches using yeast deletion mutants provided new insights on the activity of Lf against yeast that were then validated in human cancer cell lines. Results will be discussed in an integrated manner regarding their contribution towards understanding the molecular basis of Lf anticancer activity. In addition, this study highlights the great potential of yeast as a model to uncover mechanisms of action occurring in the more complex human cells. References (1) Acosta-Zaldívar M, Andrés MT, Rego A, Pereira CS, Fierro JF, Côrte-Real M. (2016) Human lactoferrin triggers a mitochondrial- and caspase-dependent regulated cell death in Saccharomyces cerevisiae. Apoptosis. 21(2):163-73. doi: 10.1007/s10495-015-1199-9. (2) Pereira CS, Guedes JP, Gonçalves M, Loureiro L, Castro L, Gerós H, Rodrigues LR, Côrte-Real M. (2016) Lactoferrin selectively triggers apoptosis in highly metastatic breast cancer cells through inhibition of plasmalemmal V-H+-ATPase. Oncotarget. 7(38):62144-62158. doi: 10.18632/oncotarget.11394.info:eu-repo/semantics/publishedVersio