Biology subjects

Granados-Aparici, S.

Publications and source records attributed to Granados-Aparici, S..

4 recordsLinked to original sources

bioRxiv2025

DANEELpath: Open-source Digital analysis tools for histopathological research. Applications in NEuroblastoma modELs

Despite the considerable expansion of bioimage analysis as a subfield of biomedical sciences, there is an ongoing need for comprehensive image analysis pipelines to address specific biological inquiries. In the tumor microenvironment, the extracellular matrix (ECM) plays a pivotal role in cancer progression, promoting tumor cell adaptability, intratumor heterogeneity, and therapeutic resistance. In neuroblastoma (NB), the ECM glycoprotein vitronectin (VN) has been associated with more aggressive tumors. Three-dimensional (3D) hydrogels are an emerging biomimetic tool with significant potential for studying the role of ECM elements and testing new mechano-drugs such as cilengitide (CLG), a potential therapeutic agent to treat high-risk (HR) NB due to its ability to inhibit VN activity in cells. To gain a more detailed understanding of the effects of VN and CLG in 3D-grown NB cells, we developed DANEELpath, an open-source image analysis toolkit. DANEELpath integrates deep learning techniques, specific segmentation of individual and cluster cells through mathematical morphology pipelines, and extraction of spatial features within whole-slide images. Thanks to its versatility, DANEELpath is adaptable to address different biological questions and has significant potential for use in a variety of research fields and model systems, which could help advance biomedical discovery.

cancer biology↗

bioRxiv2025

Vitronectin binding affinity and cell viability effect of novel mechanotherapy drugs for neuroblastoma

High-risk neuroblastoma (HR-NB) is an aggressive form of childhood cancer with a five-year survival rate of under 50%, underscoring the need for more efficacious and less toxic treatments. The glycoprotein Vitronectin (VN) has been linked to poor prognosis in patients with HR-NB, and thus inhibitors of its function represent a promising avenue for molecular mechanotherapy. The present study sought to investigate the binding affinity between the somatomedin B (SMB) domain of VN and natural compounds derived from medicinal plants. The therapeutic potential of -amyrin (AMY), lupeol (LUP), and Olax chalcone A (Olax CHA) was tested in combination with an integrin antagonist of VN, cilengitide (CLG), using the SK-N-BE(2) HR-NB cell line as a model. Molecular docking studies indicated a potential for protein-ligand interactions for all selected compounds, of which CLG demonstrated the most favorable binding free energy (kcal/mol), followed by LUP, AMY and Olax CHA. Molecular dynamics simulations demonstrated that the SMB domain of VN initially exhibited flexibility, with alpha carbon-root mean square deviation (RMSD) stabilizing at approximately 1.8-2.1 [A]. While all compounds demonstrated a dose-dependent decrease in SK-N-BE(2) cell viability, CLG exhibited higher IC50 values. Although the combination of AMY and LUP with CLG did not result in enhanced efficacy, Olax CHA exhibited a superior antiproliferative effect with higher IC50 values than AMY and LUP, and additionally showed potential synergism with CLG, suggesting a more effective therapeutic approach. This work provides valuable insights into the potential use of mechanotherapy drugs and natural products to enhance HR-NB treatment that can be expanded in future studies centered on Olax CHA.

cancer biology↗

bioRxiv2023

SMAD4 promotes somatic-germline contact during oocyte growth

Development of the mammalian oocyte requires physical contact with the surrounding granulosa cells of the follicle, which provide it with essential nutrients and regulatory signals. This contact is achieved through specialized filopodia, termed transzonal projections (TZPs), that extend from the granulosa cells to the oocyte surface. Transforming growth factor (TGF{beta}) family ligands produced by the oocyte increase the number of TZPs, but how they do so is unknown. Using an inducible Cre recombinase strategy together with expression of green fluorescent protein to verify Cre activity in individual granulosa cells, we examined the effect of depleting the canonical TGF{beta} mediator, SMAD4. We observed a 20-50% decrease in the total number of TZPs in SMAD4-depleted granulosa cell-oocyte complexes, and a 50% decrease in the number of newly generated TZPs when the granulosa cells were reaggregated with granulosa cell-free wild-type oocytes. Three-dimensional image analysis revealed that TZPs of SMAD4-depleted cells were also longer than controls and more frequently oriented towards the oocyte. Strikingly, the transmembrane proteins, N-cadherin and Notch2, were reduced by 50% in these cells. SMAD4 may thus modulate a network of cell adhesion proteins that stabilize the attachment of TZPs to the oocyte, thereby amplifying signalling between the two cell types. Impact statementGenetic deletion of SMAD4 in the granulosa cells of growing ovarian follicles reduces the number of transzonal projections that contact the oocyte, implicating TGF{beta}-family signaling in maintaining soma-germ line communication.

developmental biology↗

bioRxiv2017

Imaging seminiferous tubules - a 9.4T MRI mouse model

Fertility problems affect many couples. Research into male fertility commonly uses mouse models due to their availability and similar spermatogenesis to humans. A common target is the seminiferous tubules, the site of spermatozoa production, typically studied using biopsies and histological analysis. High-field Magnetic Resonance (MR) may offer a non-invasive alternative to investigate testicular function in infertility models. Here, we assess seminiferous tubules structure in sacrificed mice to determine the usefulness of MR compared to histology. Twelve mice (11 aged 35-57 days, one >9 months) were sacrificed and MR imaged at 9.4T with a Rapid Acquisition with Relaxation Enhancement sequence. Testes were scanned in situ for all mice, and excised in a subset of mice (n=4). A second subset of mice (n=4) had their testes selected for histological analysis. Seminiferous tubule diameter was measured manually from MRI and histology images. Custom image analysis scripts were created for the automated segmentation of seminiferous tubules and calculation of tissue volumes. All ex vivo and in situ images of testes exhibited clear outlines of seminiferous tubules. Ratio of total testis volume to volume of seminiferous tubules did not differ significantly between ex vivo and in situ measurements, and were similar in mature and younger mice. Both total testis volume and seminiferous tubule volume were larger in the mature animal. While histological slices trended towards larger average seminiferous tubules diameter than MRI images, we found no significant differences between MRI and histological measurements. High-field MRI can be used in a mouse model to assess testicular structure in situ. All volumetric measurements compared favourably with histological data. In situ scans also clearly showed identifiable extra-testicular tissues, such as epididymis and prostate tissues. The potential to image tissues associated with sperm maturation as well as spermatogenesis emphasises how MR could be a useful technique in mouse models of fertility, however further work is required to optimize tissue segmentation and validate this method for use in longitudinal studies. This type of measurement could be extended to human fertility studies in the future.

physiology↗