Biology subjects

Sobral, J.

Publications and source records attributed to Sobral, J..

4 recordsLinked to original sources

bioRxiv2025

Microbiota and Small Cell Lung Cancer.A casual bystander or a hidden culprit?

The tumor-associated microbiome is a key player in cancer development, progression, prognosis, and therapeutic response. Notably, distinct microbial signatures have been identified across cancer types. Small cell lung carcinoma (SCLC) accounts for approximately 15% of all lung cancer, yet its microbiome remains unclear. Analyzing the bacteriome composition in tissue from ten SCLC cases and in 10 cases of a heterogenous lung pathology group, we found a distinct microbial signature associated with SCLC with significantly lower diversity and higher dissimilarity, characterized by a higher relative abundance of Firmicutes and Bacteroidota, and a markedly different set of dominant genera (Pseudomonas, Streptococcus and Haemophilus) resulting in an increased Proteobacteria-to-Actinobacteria ratio. Unexpectedly, mycobiome analysis comparing pooled samples of these SCLC cases with ten pooled lung adenocarcinoma (LUAD) cases revealed that the fungal genus Taphrina was uniquely represented in SCLC. Strikingly, mycobiome individual analysis of twenty-one additional SCLC cases compared with 10 LUAD cases showed an increased prevalence of Taphrina sp. in SLCL tissue. Overall, the results suggest that SCLC microbiome is distinct from other lung pathologies and uncovers a novel link between the biotrophic plant pathogenic Taphrina and human cancer.

cancer biology↗

bioRxiv2025

Gut3Gel as an in vitro model to investigate dietary modulation of the intestinal microbiota: An inulin supplementation case study

The intestinal microbiota plays a key role in human health, influencing digestion, immunity, and metabolism. While factors such as genetics and medications shape its composition, diet remains a primary driver of microbial modulation. Despite growing interest in using dietary interventions to beneficially alter the intestinal microbiota, assessing their effects in humans is challenging due to individual variability and the complexity of in vivo systems. This study explores Gut3Gel gradient colonic (G3GG) preclinical model as a tool to assess its representativeness on studying the effect of inulin supplementation on the intestinal microbiota of five healthy individuals compared to clinical evaluation studies. Significant inter-individual variability in baseline microbiota composition was observed, which strongly influenced microbiota response to inulin. While inulin supplementation led to a general decrease in alpha diversity, it significantly increased the abundance of health-associated genera such as Bifidobacterium and Lacticaseibacillus, along with enhanced microbial metabolic activity. Despite the intrinsic selectivity of G3GG for beneficial microbes, the model successfully captured inulins prebiotic effects and inter-individual differences, underscoring its relevance as a physiologically relevant high throughput tool for evaluating microbiota-targeting compounds and supporting personalized nutrition strategies.

microbiology↗

bioRxiv2025

Gut3Gel: A High Throughput Mucus Model for Culturing Human Intestinal Microbiota

The human intestinal microbiota plays a crucial role in health and disease, yet recreating its complex interactions in vitro remains a significant challenge. Gut3Gel introduced herein as a novel in vitro mucus model, designed for culturing complex microbial communities without the need for anaerobic conditions. Intestinal microbiota samples from five donors were individually inoculated in Gut3Gel and cultured for 72 hours. Taxonomic composition assessment revealed that Gut3Gel sustains diverse microbial species and particularly promotes the growth of mucus-associated bacteria including Bifidobacterium, Lactobacillus, and Faecalibacterium. Microbial metabolic activity within Gut3Gel was confirmed by the increased production of acetate and butyrate, as well as of exopolysaccharides. Gut3Gel reproduces physiological features of intestinal mucus, providing a reproducible and scalable culturing platform. These features make Gut3Gel a promising tool for advancing microbiota research with potential applications in drug screening, microbiome mining, and high throughput testing of microbiome-modulating molecules.

microbiology↗

bioRxiv2018

The Trithorax group protein dMLL3/4 instructs the assembly of the zygotic genome at fertilization

The transition from fertilized oocyte to totipotent embryo relies on maternally-provided factors that are synthetized and accumulated in developing oocytes. Yet, it is still unclear how oocytes regulate the expression of these embryo fate-promoting genes within the general transcriptional program of oogenesis. Here we report that the Drosophila Trithorax group protein MLL3/4 (dMLL3/4, also known as Trr) is essential for the transition to embryo fate at fertilization. In the absence of dMLL3/4, oocytes develop normally but fail to initiate the embryo mitotic divisions after fertilization. This incapability results from defects in both paternal genome reprogramming and maternal meiotic completion. We show that, during oogenesis, dMLL3/4 promotes the expression of a functionally coherent gene subset that is later required for the correct assembly of the zygotic genome. Accordingly, we identify the evolutionarily-conserved IDGF4 glycoprotein (known as oviductin in mammals) as a new oocyte-to-embryo transition gene under dMLL3/4 transcriptional control. Based on these observations, we propose that dMLL3/4 plays an instructive role in the oocyte-to-embryo transition that is functionally uncoupled from the requirements of normal oocyte differentiation.

developmental biology↗