The CYP51C gene, a reliable marker to resolve interspecific phylogenetic relationships within the Fusarium species complex and a novel target for species-specific PCR

Early diagnosis and control of different Fusarium species is essential for successful management of plant disease and subsequent prevention of toxins entering the food chain. This issue can be addressed using phylogenetic analyses and other molecular techniques, including the design of species-specific primers and corresponding PCR assays. In practice, only a few genes are sequenced for most species and insights into the evolutionary mechanisms at the species level usually stem from phylogenetic analyses of only one or a small number of genetic loci. This poses the question of whether the recovered tree accurately reflects the relationships among species or rather more local interrelationships particular to the genetic marker employed. This study examined if the Fusarium-specific CYP51C gene can be used to establish evolutionary relationships between Fusarium species and enable species-specific detection. The resolving power of the CYP51C gene was studied for 46 Fusarium isolates representing 18 different species. The resulting phylogeny analysis showed clear and well-structured separation of the isolates according to their species rank, synthesised toxin and Fusarium section. Moreover, a comparison between the individual CYP51C phylogeny and a reference tree (inferred from the concatenation of ITS, CYP51C, β-tubulin and TEF-1α sequences) indicated superior resolution of CYP51C relative to ITS and β-tubulin sequences. In addition to its suitability as a reliable marker for diagnosis of different toxigenic Fusarium species, we also show that the CYP51C gene is a promising target for development of species-specific PCR. This was demonstrated by the specific detection of Fusarium cerealis in grain samples of wheat.     

Aflatoxins and ochratoxin A in different cocoa clones (Theobroma cacao L.) developed in the southern region of Bahia,Brazil

Brazil is the sixth largest producer of cocoa beans in the world, after Côte d’Ivoire, Ghana, Indonesia, Nigeria and Cameroon. The southern region of Bahia stands out as the country’s largest producer, accounting for approximately 60% of production. Due to damage caused by infestation of the cocoa crop with the fungus Moniliophthora perniciosa, which causes ‘witch’s broom disease’, research in cocoa beans has led to the cloning of species that are resistant to the disease; however, there is little information about the development of other fungal genera in these clones, such as Aspergillus, which do not represent a phytopathogenicity problem but can grow during the pre-processing of cocoa beans and produce mycotoxins. Thus, the aim of this work was to determine the presence of aflatoxin (AF) and ochratoxin A (OTA) in cocoa clones developed in Brazil. Aflatoxin and ochratoxin A contamination were determined in 130 samples from 13 cocoa clones grown in the south of Bahia by ultra-performance liquid chromatography with a fluorescence detector. The method was evaluated for limit of detection (LOD) (0.05–0.90 μg kg^?1), limit of quantification (0.10–2.50 μg kg^?1) and recovery (RSD) (89.40–95.80%) for AFB₁, AFB₂, AFG₁, AFG₂ and OTA. Aflatoxin contamination was detected in 38% of the samples in the range of ?1, with AFB₁ in 25% of the total samples, whereas ochratoxin A was positive in 18% of the samples in the range of ?1.     

Key factors influencing food security of smallholder farmers in Tanzania and the role of cassava as a strategic crop

Due to beneficial characteristics of cassava such as robustness and versatility for multiple uses, it can have a major role in contributing to local food security. The objective of this study was to find out whether and how the cultivation of cassava benefits smallholder farmers in the regions of Dodoma and Morogoro, Tanzania. In addition, the study assessed the main factors that support or threaten food security of smallholder farmer households in the survey region and analysed whether cassava cultivation could counteract them. We applied a mixed methods approach. Quantitative data were provided by a comprehensive household survey of the Trans-SEC project, and qualitative data were collected by conducting semi-structured interviews. To approach the complexity of our chosen food security definition, three approaches for household food security measurement were applied. These covered the components of food availability, food access, and food utilization. Additionally, dependent variables for regression models were constructed and a multivariate analysis was run. The results show that cassava contributes to food security in the households, but achieving food security through cassava cultivation was constrained by several factors, including pests, missing markets, poor processing, social perception and lack of knowledge. Besides these, other factors affecting food security in the study area were found, uncovering some roots of local food insecurity and serving as a basis for further research and action on how to enhance food security.     

Chemokine CXCL10 Modulates the Tumor Microenvironment of Fibrosis-Associated Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) constitutes a devastating health burden. Recently, tumor microenvironment-directed interventions have profoundly changed the landscape of HCC therapy. In the present study, the function of the chemokine CXCL10 during fibrosis-associated hepatocarcinogenesis was analyzed with specific focus on its impact in shaping the tumor microenvironment. C57BL/6J wild type (WT) and Cxcl10 knockout mice (Cxcl10^−/−) were treated with diethylnitrosamine (DEN) and tetrachloromethane (CCl₄) to induce fibrosis-associated HCCs. Cxcl10 deficiency attenuated hepatocarcinogenesis by decreasing tumor cell proliferation as well as tumor vascularization and modulated tumor-associated extracellular matrix composition. Furthermore, the genetic inactivation of Cxcl10 mediated an alteration of the tumor-associated immune response and modified chemokine/chemokine receptor networks. The DEN/CCl₄-treated Cxcl10^−/− mice presented with a pro-inflammatory tumor microenvironment and an accumulation of anti-tumoral immune cells in the tissue. The most striking alteration in the Cxcl10^−/− tumor immune microenvironment was a vast accumulation of anti-tumoral T cells in the invasive tumor margin. In summary, our results demonstrate that CXCL10 exerts a non-redundant impact on several hallmarks of the tumor microenvironment and especially modulates the infiltration of anti-tumorigenic immune cells in HCC. In the era of microenvironment-targeted HCC therapies, interfering with CXCL10 defines a novel asset for further improvement of therapeutic strategies.     

Regulatory T Cells with Additional COX-2 Expression Are Independent Negative Prognosticators for Vulvar Cancer Patients

Vulvar cancer incidence numbers have been steadily rising over the past decades. In particular, the number of young patients with vulvar cancer has recently increased. Therefore, the need to identify new prognostic factors and, in addition, therapeutic options for vulvar carcinoma is more apparent. The aim of this study was to analyze the influx of COX-2 positive tumor-infiltrating lymphocytes and monocytes and their influence on prognosis. Using subtyping by immunofluorescence, the majority of COX-2 expressing immune cells were identified as FOXP3-positive regulatory T cells. In addition, peri- and intra-tumoral macrophages in the same tumor tissue were detected simultaneously as M2-polarized macrophages. COX-2 positive immune cells were independent negative prognostic markers in long-term overall survival of patients with vulvar cancer. These results show an influence of immune cell infiltration for vulvar carcinoma patients. Immune cell infiltration and immune checkpoint expression may, therefore, become interesting targets for further research on new vulvar cancer treatment strategies.     

Making Connections: Mesenchymal Stem Cells Manifold Ways to Interact with Neurons

Mesenchymal Stem Cells (MSCs) are adult multipotent cells able to increase sensory neuron survival: direct co-culture of MSCs with neurons is pivotal to observe a neuronal survival increase. Despite the identification of some mechanisms of action, little is known about how MSCs physically interact with neurons. The aim of this paper was to investigate and characterize the main mechanisms of interaction between MSCs and neurons. Morphological analysis showed the presence of gap junctions and tunneling nanotubes between MSCs and neurons only in direct co-cultures. Using a diffusible dye, we observed a flow from MSCs to neurons and further analysis demonstrated that MSCs donated mitochondria to neurons. Treatment of co-cultures with the gap junction blocker Carbenoxolone decreased neuronal survival, thus demonstrating the importance of gap junctions and, more in general, of cell communication for the MSC positive effect. We also investigated the role of extracellular vesicles; administration of direct co-cultures-derived vesicles was able to increase neuronal survival. In conclusion, our study demonstrates the presence and the importance of multiple routes of communication between MSCs and neurons. Such knowledge will allow a better understanding of the potential of MSCs and how to maximize their positive effect, with the final aim to provide the best protective treatment.     

Brain Proteome and Behavioural Analysis in Wild Type,BDNF+/− and BDNF−/− Adult Zebrafish (Danio rerio) Exposed to Two Different Temperatures

Experimental evidence suggests that environmental stress conditions can alter the expression of BDNF and that the expression of this neurotrophin influences behavioural responses in mammalian models. It has been recently demonstrated that exposure to 34 °C for 21 days alters the brain proteome and behaviour in zebrafish. The aim of this work was to investigate the role of BDNF in the nervous system of adult zebrafish under control and heat treatment conditions. For this purpose, zebrafish from three different genotypes (wild type, heterozygous BDNF^+/− and knock out BDNF^−/−) were kept for 21 days at 26 °C or 34 °C and then euthanized for brain molecular analyses or subjected to behavioural tests (Y-maze test, novel tank test, light and dark test, social preference test, mirror biting test) for assessing behavioural aspects such as boldness, anxiety, social preference, aggressive behaviour, interest for the novel environment and exploration. qRT-PCR analysis showed the reduction of gene expression of BDNF and its receptors after heat treatment in wild type zebrafish. Moreover, proteomic analysis and behavioural tests showed genotype- and temperature-dependent effects on brain proteome and behavioural responding. Overall, the absent expression of BDNF in KO alters (1) the brain proteome by reducing the expression of proteins involved in synapse functioning and neurotransmitter-mediated transduction; (2) the behaviour, which can be interpreted as bolder and less anxious and (3) the cellular and behavioural response to thermal treatment.