Biology subjects

Goncalves, I.

Publications and source records attributed to Goncalves, I..

8 recordsLinked to original sources

bioRxiv2025

FrlP, an ABC type I importer component of Bacillus subtilis: regulation and impact in bacterial fitness

Bacillus subtilis is able to catabolize fructosamines, also known as Amadori rearrangement products. The frlBONMD-frlP operon mediates this process and is subjected to specific and global regulation. Although the degradation pathway favoring -glycated amino acids is known, the mechanisms of substrate uptake have remained unclear. In this study, mutagenic and functional analyses revealed that FrlONM, a type I ABC importer, along with the nucleotide-binding domain (NBD) FrlP, is required for the uptake of fructosevaline. Transcriptional and translation frlP-lacZ fusions indicated that frlP is induced by fructosevaline and negatively regulated by the FrlR repressor. Furthermore, by targeting an RNA molecule (S1254) encoded upstream from frlP and overlapping the repressor flrR gene transcribed in the opposite direction, we provide evidence for the dual regulation of frlP by this anti-sense RNA and FrlR. This result adds a posttranscriptional layer to the intricate regulation of the fructosamines operon. In addition, we show that MsmX, a multitask NBD of B. subtilis, is also able to serve as energy motor of this type I ABC importer, and that its presence alongside FrlP is vital for optimal growth on fructosevaline. To address the physiological significance of this functional redundancy we assessed the distribution of ABC type I NBDs FrlP and MsmX across the Bacillaceae family. MsmX is homogeneously distributed in Bacillaceae family tree, while FrlP is restricted to the Bacillus subtilis group, suggesting that the presence of FrlP together with other components of the fructosamines operon is important for bacteria fitness in plant-associated ecological niches. ImportanceBacillus subtilis is widely applied in the industry as a microbial cell factory, as a biofertilizer for sustainable agriculture, in the animal feed industry and as human probiotic. In its natural environment B. subtilis helps to shape the gut microbiome and the phytomicrobiome. Fructosamines, or Amadori rearrangement products, are ubiquitously found in nature and serve as precursors of toxic cell end-products implicated in the pathology of human diseases. This study provides a solid contribution to a deep knowledge of transport mechanisms, genetic regulation and physiological relevance of fructosamines utilization in B. subtilis. Moreover, it highlights an unusual strategy to adapt to alterations in nutrient availability by swapping the energy providing domain of ABC transporters.

microbiology↗

bioRxiv2025

Glioblastoma cells taste temozolomide via TAS2R43

Bitter taste receptors (TAS2Rs) have a widespread expression in various extraoral organs where they detect the chemical composition of body fluids and trigger biological responses accordingly. Among the chemicals recognised by TAS2Rs there are natural and synthetic compounds including therapeutic drugs. We have shown that TAS2Rs are expressed in the blood-cerebrospinal fluid barrier where they regulate efflux transporters, thereby controlling the transport of compounds into the cerebrospinal fluid. More recently, we assessed the expression of these receptors in human glioblastoma cells, where 20 out of the 26 human TAS2Rs were identified. In this study, we investigated if temozolomide, the standard chemotherapy for glioblastoma, activates the bitter signalling pathway with impact in its therapeutic efficacy. Notably, we found that blocking the bitter taste signalling pathway significantly reduced the anti-proliferative and pro-apoptotic effects of temozolomide, and identified TAS2R43 as the receptor mediating these effects. We propose that upon ligand binding, TAS2R43 modulates multidrug resistance proteins (MDRs) activity, facilitating temozolomide entrance into glioblastoma cells. These findings underscore the importance of the taste transduction pathway in evaluating the chemical composition of the glioblastoma microenvironment. Furthermore, our data suggest that TAS2R43 could serve as a biomarker for the efficacy of temozolomide and other drugs that are substrates of MDRs.

cancer biology↗

bioRxiv2025

Sweet taste receptor regulates proliferation and glucose uptake in glioblastoma cells

Glioblastoma is a brain tumour classified by the World Health Organization as grade 4 due to its aggressiveness, invasiveness, and poor differentiation. Current standard therapies remain largely ineffective, reinforcing the need for novel targets to improve glioblastoma prognosis. Reprogramming of cellular metabolism is an important hallmark of cancer, marked by a shift from oxidative phosphorylation to glycolysis as the primary energy source. This metabolic switch, known as the Warburg effect, is exacerbated by the reduced oxygen and glucose availability in the tumour microenvironment. The sweet taste receptor (STR) is an important glucosensor with recognised role in the regulation of glucose uptake in several organs and in astrocytes, the glioblastoma precursor cells. We hypothesised that STR may regulate glucose uptake and metabolism in glioblastoma, representing a potential anticancer target. To test this, we investigated the effects of STR inhibition with lactisole, a specific TAS1R3 inhibitor, in three glioblastoma cell lines (U-87MG, SNB-19 and U-373MG) and in the UPCI-SCC-154 tongue cancer cell line. We provided evidence that STR inhibition consistently reduced cell viability and migration, without inducing apoptosis or necrosis, and impaired glucose uptake and L-lactate production, particularly in tongue cancer UPCI-SCC-154, and glioblastoma U-87MG and SNB-19 cells. Moreover, in a 3D spheroid model, lactisole reduced the invasion capacity of U-87MG glioblastoma spheroids. These results suggest that STR contributes to glioblastoma cell metabolism and behaviour and may represent a promising therapeutic target.

cancer biology↗

bioRxiv2025

Taste receptors' profiling in glioblastoma

Glioblastoma is the most common and aggressive form of primary brain cancer. Despite significant progress in the development of promising therapeutic agents, cancer-targeting therapies often fail to achieve effective concentrations in the brain, limiting their therapeutic efficacy. As such, a deeper understanding of how glioblastoma tumours interact with their microenvironment and assess the chemical composition therein can reveal novel therapeutic strategies. Recent studies have highlighted the critical role of taste receptors, particularly bitter taste receptors (TAS2Rs) and their ligands in cancer progression and metastasis. Activation of TAS2Rs by both natural and synthetic compounds has been associated with drug resistance, apoptosis, and the proliferation of malignant tumours. The sweet taste receptor TAS1R2/TAS1R3, or the umami receptor TAS1R1/TAS1R3, as recognised sensors of glucose levels and aminoacids, respectively, are also of interest in the context of cancer metabolism. In this study, we investigated the expression and function of TAS2Rs, TAS1R2/TAS1R3 and TAS1R1/TAS1R3 and all the taste signalling pathway machinery in glioblastoma. Our findings demonstrate that TAS1R2/TAS1R3, TAS1R1/TAS1R3, and 20 out of the 26 human TAS2Rs are present and active in glioblastoma cells, with expression differences in glioblastoma cells and human tumours. The expression of such a large number of members of this family of receptors, highlight the significance of the taste transduction pathway in this form of brain cancer, where these receptors might be essential for the crosstalk between glioblastoma and its microenvironment.

cancer biology↗

bioRxiv2025

TWIST1 drives endothelial-to-mesenchymal-transition to stabilize atherosclerotic plaques

Atherosclerosis progresses from fatty streaks to complex plaques, with rupture leading to life-threatening complications. Endothelial-to-mesenchymal transition (EndMT) is associated with advanced atherosclerotic plaques, but its role in plaque progression remains unclear. To investigate this, we analyzed the role of TWIST1, a key EndMT-driving transcription factor, in plaque development. Using single-cell RNA sequencing of atherosclerotic plaques from hypercholesterolemic mice with inducible deletion of Twist1 from endothelial cells (Twist1ECKO ApoE-/-) we demonstrate that Twist1 regulates endothelial cell heterogeneity by promoting cell states expressing EndMT markers. Cell tracking confirmed that Twist1 induces EndMT in advanced plaques. Mechanistically, we found that TWIST1 contributes to EndMT by promoting endothelial migration and proliferation through the transcriptional coactivator PELP1. Additionally, TWIST1 induces AEBP1 transcription, which upregulates COL4A1 to drive endothelial proliferation. Analyses of murine brachiocephalic plaques show that endothelial Twist1 promotes plaque growth, collagen deposition, and ACTA2-positive cell accumulation, hallmarks of plaque stability, while reducing necrosis and macrophage infiltration, features of plaque instability. Moreover, TWIST1 expression was associated with asymptomatic human carotid atherosclerosis and predicts favourable clinical outcomes. These findings challenge the prevailing view that EndMT destabilizes plaques, by suggesting that TWIST1-driven EndMT can promote plaque stability, offering new insights into atherosclerosis pathophysiology and therapeutic potential.

pathology↗

bioRxiv2024

Embedding bioprinting of low viscous, photopolymerizable blood-based bioinks in a self-healing transparent supporting bath

Protein-based hydrogels have great potential to be used as bioinks for biofabrication-driven tissue regeneration strategies due to their innate bioactivity. Nevertheless, their use as bioinks in conventional 3D bioprinting is impaired due to their intrinsic low viscosity. Using embedding bioprinting, a liquid bioink is printed whithin a support that physically holds the patterned filament. Inspired by the recognized microencapsulation technique complex coacervation, we introduce crystal self-healing embedding bioprinting (CLADDING) based on a highly transparent crystal supporting bath. The suitability of distinct classes of gelatins was evaluated (i.e., molecular weight distribution, isoelectric point and ionic content), as well as the formation of gelatin-gum arabic microparticles as a function of pH, temperature, solvent and mass ratios. Characterizing and controlling this parametric window resulted in high yields of support bath with ideal self-healing properties for interaction with protein-based bioinks during bioprinting. This support bath achieved transparency, which boosted light permeation within the bath. CLADDING bioprinted constructs fully composed of platelet lysates encapsulating a co-culture of human mesenchymal stem cells and endothelial cells were obtained, demonstrating high-dense cellular network with excellent cell viability and stability over a month. CLADDING broadens the spectrum of photocrosslinkable materials with extremely low viscosity that can now be bioprinted with sensitive cells using embedding bioprinting without any additional support.

bioengineering↗

bioRxiv2020

The infection cushion: a fungal weapon of plant-biomass destruction

O_LIGrey mold disease affects fruits, vegetables and ornamental plants around the world, causing considerable losses every year. Its causing agent, the necrotrophic fungus Botrytis cinerea, produces infection cushions (IC) that are compound appressorial structures dedicated to the penetration of the plant tissues. C_LIO_LIA microarray analysis was performed to identify genes up-regulated in mature IC. The expression data were supported by RT-qPCR analysis performed in vitro and in planta, proteomic analysis of the IC secretome and mutagenesis of two candidate genes. C_LIO_LI1,231 up-regulated genes and 79 up-accumulated proteins were identified. They highlight a secretion of ROS, secondary metabolites including phytotoxins, and proteins involved in virulence: proteases, plant cell wall degrading enzymes and necrosis inducers. The role in pathogenesis was confirmed for two up-regulated fasciclin genes. DHN-melanin pathway and chitin deacetylases genes are up-regulated and the conversion of chitin into chitosan was confirmed by differential staining of the IC cell wall. In addition, up-regulation of sugar transport and sugar catabolism encoding genes was found. C_LIO_LIThese results support a role for the B. cinerea IC in plant penetration and suggest other unexpected roles for this fungal organ, in camouflage, necrotrophy or nutrition of the pathogen. C_LI

microbiology↗

bioRxiv2017

Combining Bayesian Approaches and Evolutionary Techniques for the Inference of Breast Cancer Networks

Gene and protein networks are very important to model complex large-scale systems in molecular biology. Inferring or reverseengineering such networks can be defined as the process of identifying gene/protein interactions from experimental data through computational analysis. However, this task is typically complicated by the enormously large scale of the unknowns in a rather small sample size. Furthermore, when the goal is to study causal relationships within the network, tools capable of overcoming the limitations of correlation networks are required. In this work, we make use of Bayesian Graphical Models to attach this problem and, specifically, we perform a comparative study of different state-of-the-art heuristics, analyzing their performance in inferring the structure of the Bayesian Network from breast cancer data.

bioinformatics↗