Biology subjects

de Oliveira, S.

Publications and source records attributed to de Oliveira, S..

6 recordsLinked to original sources

bioRxiv2026

Embryonic TGF-β signaling imposes persistent changes to HSPC clonality and inflammatory landscape

Embryonic hematopoiesis is essential for establishing lifelong blood and immune system function. During development, hematopoietic stem and progenitor cells (HSPCs) acquire intrinsic programs that persist into adulthood and can influence disease susceptibility, yet the molecular signals governing these early-life decisions remain poorly understood. Here, we investigated the role of developmental Transforming Growth Factor-{beta} (TGF-{beta}) signaling in regulating HSPC lineage bias and long-term hematopoietic outcomes. Using the zebrafish model, we found that transient embryonic TGF-{beta} signaling inhibition during the HSPC specification window altered their frequency and migration after emergence from the hemogenic endothelium and movement into the key secondary maturation and expansion niche. Single-cell transcriptomic analysis of embryonic HSPCs revealed repression of migration- and cytoskeleton-associated genes alongside dampened expression of myeloid/macrophage-related genes following ALK5 inhibition. Functionally, early ALK5 blockade reduced macrophage numbers and promoted an M2-like immunosuppressive transcriptional profile. These developmental perturbations produced sustained effects on hematopoietic and immune function into adulthood, including diminished inflammatory gene expression, reduced clonal complexity, and impaired regenerative capacity. Together, our findings identify embryonic TGF-{beta} signaling as a key developmental regulator of HSPC fate and immune programming, with potential implications for immune dysfunction and susceptibility to inflammatory-related disease later in life. PAPER HIGHLIGHTS- Transient developmental signaling perturbations reshape hematopoietic trajectories - Embryogenic TGF-{beta} signaling instructs HSPC lineage priming and macrophage specialization - Early HSPC programming establishes persistent inflammatory states, clonal diversity, and modifies regenerative capacity

developmental biology↗

bioRxiv2025

Synthetic multicolor antigen-stabilizable nanobody platform for intersectional labelling and functional imaging.

We present a synthetic toolkit of antigen-stabilizable fluorescent nanobodies (VIS-Fbs) spanning the entire visible spectrum from 450 nm to 660 nm. By engineering over twenty fluorescent proteins (FPs) and biosensors into eight nanobodies, we established a generalizable design of VIS-Fbs, which fluoresce brightly only upon binding to cognate antigens. Our synthetic approach includes constitutive, photoactivatable and photoswitchable FPs, and intensiometric FP-based biosensors. VIS-Fbs carrying biosensors enable simultaneous monitoring of two metabolites at confined locations, while FP-based VIS-Fbs targeting biosensors allow ratiometric functional imaging in the mouse brain. We further used VIS-Fbs to track endogenous {beta}-catenin dynamics in zebrafish embryos during normal development and under Wnt/{beta}-catenin signaling modulation. VIS-Fbs provide background-free visualization of intracellular proteins, multicolor detection of multiple antigens, and selective targeting of defined cell populations and compartments. This synthetic biology-driven platform enables precise studies of protein dynamics, cellular processes, and complex biological systems with high specificity and minimal background.

synthetic biology↗

bioRxiv2024

Neutrophil immune profile controls spinal cord regeneration in zebrafish

Spinal cord injury triggers a strong innate inflammatory response in both non-regenerative mammals and regenerative zebrafish. Neutrophils are the first immune population to be recruited to the injury site. Yet, their role in the repair process, particularly in a regenerative context, remains largely unknown. Here, we show that, following rapid recruitment to the injured spinal cord, neutrophils mostly reverse migrate throughout the zebrafish body. In addition, promoting neutrophil inflammation resolution by inhibiting Cxcr4 boosts cellular and functional regeneration. Neutrophil-specific RNA-seq analysis reveals an enhanced activation state that correlates with a transient increase in tnf- expression in macrophage/microglia populations. Conversely, blocking neutrophil recruitment through Cxcr1/2 inhibition diminishes the presence of macrophage/microglia at the injury site and impairs spinal cord regeneration. Altogether, these findings provide new insights into the role of neutrophils in spinal cord regeneration, emphasizing the significant impact of their immune profile on the outcome of the repair process. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=185 HEIGHT=200 SRC="FIGDIR/small/576035v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@6153f1org.highwire.dtl.DTLVardef@1ce09faorg.highwire.dtl.DTLVardef@1f11187org.highwire.dtl.DTLVardef@1b5c152_HPS_FORMAT_FIGEXP M_FIG C_FIG

developmental biology↗

bioRxiv2023

A zebrafish xenotransplant model of anaplastic thyroid cancer to study the tumor microenvironment and innate immune cell interactions in vivo.

Anaplastic thyroid cancer (ATC) is a rare malignant subtype of thyroid cancer. While ATC is rare it accounts for a disproportionately high number of thyroid cancer-related deaths. Here we developed an ATC xenotransplant model in zebrafish larvae, where we can study tumorigenesis and therapeutic response in vivo. Using both mouse (T4888M) and human (C643) derived fluorescently labeled ATC cell lines we show these cell lines display different engraftment rates, mass volume, proliferation, and angiogenic potential. Next, using a PIP-FUCCI reporter to track proliferation in-vivo we observed cells in each phase of the cell cycle. Additionally, we performed long-term non-invasive intravital microscopy over 48 hours to understand cellular dynamics in the tumor microenvironment at the single cell level. Lastly, we tested a well-known mTOR inhibitor to show our model could be used as an effective screening platform for new therapeutic compounds. Altogether, we show that zebrafish xenotransplants make a great model to study thyroid carcinogenesis and the tumor microenvironment, while also being a suitable model to test new therapeutics in vivo. SUMMARY STATEMENTAnaplastic thyroid cancer xenotransplant model in zebrafish larvae to study thyroid cancer tumorigenesis and tumor microenvironment. Using confocal microscopy to understand cell cycle progression, interactions with the innate immune system, and test therapeutic compounds in vivo.

cancer biology↗

bioRxiv2021

Neutrophil reverse migration from liver fuels neutrophilic inflammation to tissue injury in Nonalcoholic Steatohepatitis.

Inflammation is a hallmark in the progression of nonalcoholic-fatty liver disease (NAFLD) to non-alcoholic steatohepatitis (NASH). Patients with NAFLD are characterized by a chronic low-grade systemic metabolic inflammation (i.e., metainflammation), which contributes to exacerbated however dysfunctional immune response. Neutrophils play an important pathological role in NAFLD progression to NASH; however, how NASH and associated chronic systemic inflammation impact overall the neutrophil response to injury is completely unexplored. Here, we investigated how neutrophil response to tissue injury is altered by the presence of NASH. We used a diet-induced NASH zebrafish model combined with tailfin transection in transgenic zebrafish larvae to study neutrophilic inflammation. Live non-invasive confocal microscopy was used to investigate neutrophil recruitment to tailfin injury through time. Photoconvertion of neutrophils at the liver area followed by time-lapse microscopy was performed to evaluate migration of neutrophils from liver to tailfin injury. Metformin and Pentoxifylline were used to pharmacologically reduce NASH and liver inflammation. We found that larvae with NASH display systemic inflammation and increased myelopoiesis. NASH larvae display a dysfunctional and exacerbated neutrophil response to tailfin injury, characterized by increased neutrophil recruitment, and delayed resolution of inflammation. Interestingly, we showed that neutrophils undergo reverse migration from the NASH liver to the wounded tailfin area. Finally, pharmacological treatment of NASH with Pentoxifylline and Metformin significantly reduced systemic chronic inflammation and the exacerbated recruitment of neutrophils to tissue injury. Taken together, our findings suggest that NASH exacerbates neutrophilic inflammation probably via neutrophil priming at the liver, which can further undergo reverse migration and respond to secondary inflammatory triggers such as tissue injury. Reverse migration of primed neutrophils from the liver might be an important mechanism that fuels the exacerbated neutrophil response observed in NASH conditions and associated metainflammation contributing to poor prognosis and increasing death in patients with metabolic syndrome.

immunology↗

bioRxiv2019

DNAJB1-PRKACA fusion induces liver inflammation in zebrafish model of Fibrolamellar Hepatocellular Carcinoma

Fibrolamellar Hepatocellular Carcinoma (FLC) is a rare liver cancer that primarily affects adolescents and young adults. Up to now there is only one identified molecular target responsible for driving the disease, the chimeric protein encoded by DNAJB1-PRKACA (J-PKAca). Immune cells have been identified as key players in liver cancer biology, however the effect of J-PKAca on inflammation in the liver microenvironment is not known. Here we report a new zebrafish model of FLC with non-invasive live imaging capabilities that allows the study of the interactions between immune cells and transformed hepatocytes. We found that overexpression of the dnajb1a-prkcaaa fusion gene specifically in hepatocytes induces early malignancy features in FLC transgenic larvae, such as increased liver and hepatocyte size. In addition, this aberrant form of PKA promotes a pro-inflammatory liver microenvironment by increasing the number of neutrophils and macrophages in the liver area and inducing macrophage polarization to a pro-inflammatory phenotype. Increased caspase-a activity was also found in the liver of FLC transgenic larvae. Importantly, pharmacological inhibition of TNF secretion and caspase-a activity decreased liver size and inflammation. Overall, these findings suggest that inflammation may be an early feature of FLC involved in progression, and that targeting TNFand caspase-1 may be beneficial in treating FLC.

cancer biology↗