Biology subjects

Matias, D.

Publications and source records attributed to Matias, D..

6 recordsLinked to original sources

bioRxiv2026

Distinct afferent signatures onto anterior and posterior VMHvl subdomains and their progesterone receptor-expressing neurons

Female sexual behavior is fundamentally coupled to reproductive state, requiring the dynamic and coordinated regulation of sexual receptivity and rejection across the estrous cycle. In mice, these opposing behaviors are controlled by distinct neuronal subpopulations within the anteroposterior subdomains of the ventrolateral ventromedial hypothalamus (VMHvl): the posterior VMHvl (pVMHvl) promotes sexual receptivity, whereas the anterior VMHvl (aVMHvl) drives sexual rejection. Although progesterone receptor-expressing (PR) neurons in both subregions are essential for these behaviors, the circuit mechanisms underlying this anteroposterior functional segregation remain poorly understood. Here, we investigated whether anterior and posterior VMHvl subdomains receive distinct afferent inputs that could support their divergent roles, and whether these inputs specifically target PR neurons. By combining retrograde tracing with whole-brain, machine learning-assisted quantification, we first mapped the afferent connectivity of the aVMHvl and pVMHvl. We found that while the two subdomains share the majority of their inputs, they also receive distinct and biased projections. The aVMHvl preferentially receives inputs from the anterior hypothalamic nucleus, paraventricular and peripeduncular thalamic nuclei, and the parabrachial nucleus, while the pVMHvl is preferentially innervated by the preoptic area, dorsal and ventral premammillary nuclei and anteroventral periventricular nucleus. To determine whether the identified afferents directly synapse onto the PR neurons, we performed monosynaptic rabies tracing from anterior and posterior VMHvl PR neurons. These experiments revealed that most anterior- and posterior-biased projections directly targeted PR VMHvl neurons. In addition, projections from the paraventricular thalamus, periaqueductal gray, and several pontine nuclei preferentially innervated aVMHvlPR neurons, whereas inputs from the mammillary nuclei mostly targeted pVMHvlPR neurons. Together, our results reveal distinct afferent architectures onto anterior and posterior PR VMHvl neurons, providing a circuit-level framework for understanding how hormonal state flexibly biases female sexual behavior toward receptivity or rejection.

neuroscience↗

bioRxiv2025

Transferrin Receptor 1-targeted polymersomes therapy for Colorectal Cancer

Colorectal cancer (CRC) is a major global health concern, ranking among the most common cancers and the second leading cause of cancer-related deaths. The high mortality associated with CRC is attributed mainly to difficulties in early detection and the lack of effective targeted therapies. The Transferrin receptor 1 (TfR1) is particularly attractive as a therapy target given its notable overexpression in tumor cells, particularly in CRC. This study explored the potential of a polymeric nanoparticle (POs)-based drug delivery system targeting TfR1 to improve the precision and efficacy of CRC treatment. For this study, we used three human colorectal cancer cell lines (SW480, HT-29, and HCT116), a healthy human intestinal epithelial cell line (hIECs), and a murine CRC cell line (MC38). We first engineered POs composed of poly (ethylene glycol) (PEG) and poly (lactic acid) (PLA), functionalized with the T7 peptide to enhance their specificity for TfR1-expressing cells. Targeting efficiency of these POs was assessed across all cell lines by evaluating the cellular uptake using flow cytometry. Upon establishing the optimal formulation for these NPs for TfR1-targeting, we encapsulated doxorubicin (DOX) to evaluate their therapeutic potential. Both in vitro and in vivo studies were performed to assess the efficacy of these DOX-loaded TfR1-targeted POs. In vitro studies demonstrated selective delivery of DOX to CRC cells, suggesting a marked reduction in off-target effects. In vivo studies in a murine model of CRC further supported these findings, showing that DOX-loaded TfR1-targeted POs significantly improved survival rates and reduced tumor growth compared to free DOX or PBS treatments. These results highlight the promise of TfR1-targeted POs as a precise strategy for CRC therapy, offering enhanced treatment efficacy while reducing systemic toxicity. This novel approach could lead to the development of more targeted and less harmful cancer treatments. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=76 SRC="FIGDIR/small/639871v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@1714603org.highwire.dtl.DTLVardef@1ab7f15org.highwire.dtl.DTLVardef@245f6eorg.highwire.dtl.DTLVardef@1f56f75_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIT-7 peptide-functionalized polymersomes exhibit high binding affinity to CRC cell lines C_LIO_LIDoxorubicin-loaded T7-peptide polymersomes effectively suppress tumor growth and prolong survival in vivo C_LIO_LITargeted Doxorubicin delivery via T7-peptide polymersomes minimizes toxicity to healthy tissues C_LI

cancer biology↗

bioRxiv2022

A Multiscale study of phosphorylcholine driven cellular phenotypic targeting

Phenotypic targeting requires the ability of the drug delivery system to discriminate over cell populations expressing a particular receptor combination. Such selectivity control can be achieved using multiplexed-multivalent carriers often decorated with multiple ligands. Here, we demonstrate that the promiscuity of a single ligand can be leveraged to create multiplexed-multivalent carriers achieving phenotypic targeting. We show how the cellular uptake of poly(2-methacryloyloxyethyl phosphorylcholine)-poly(2- (diisopropylamino)ethyl methacrylate) (PMPC-PDPA) polymersomes varies depending on the receptor expression among different cells. We investigate the PMPC-PDPA polymersome insertion at the single chain/receptor level using all-atom molecular modelling. We propose a theoretical statistical mechanics-based model for polymersome-cell association that explicitly considers the interaction of the polymersome with the cell glycocalyx shedding light on its effect on the polymersome binding. We validate our model experimentally and show that the binding energy is a non-linear function, allowing us to tune interaction by varying the radius and degrees of polymerisation. Finally, we show that PMPC-PDPA polymersomes can be used to target monocytes in vivo due to their promiscuous interaction with SRB1, CD36 and CD81.

biochemistry↗

bioRxiv2021

GCAT|Panel, a comprehensive structural variant haplotype map of the Iberian population from high-coverage whole-genome sequencing

The combined analysis of haplotype panels with phenotype clinical cohorts is a common approach to explore the genetic architecture of human diseases. However, genetic studies are mainly based on single nucleotide variants (SNVs) and small insertions and deletions (indels). Here, we contribute to fill this gap by generating a dense haplotype map focused on the identification, characterization and phasing of structural variants (SVs). By integrating multiple variant identification methods and Logistic Regression models, we present a catalogue of 35,431,441 variants, including 89,178 SVs ([≥]50bp), 30,325,064 SNVs and 5,017,199 indels, across 785 Illumina high coverage (30X) whole-genomes from the Iberian GCAT Cohort, containing 3.52M SNVs, 606,336 indels and 6,393 SVs in median per individual. The haplotype panel is able to impute up to 14,360,728 SNVs/indels and 23,179 SVs, showing a 2.7-fold increase for SVs compared with available genetic variation panels. The value of this panel for SVs analysis is shown through an imputed rare Alu element located in a new locus associated with mononeuritis of lower limb, a rare neuromuscular disease. This study represents the first deep characterization of genetic variation within the Iberian population and the first operational haplotype panel to systematically include the SVs into genome-wide genetic studies.

genomics↗

bioRxiv2020

Cyclopamine sensitizes Glioblastoma cells to Temozolomide treatment through Sonic Hedgehog pathway

AimGlioblastoma is an extremely aggressive glioma, resistant to radio and chemotherapy usually performed with temozolomide. One of the main reasons for glioblastoma resistance to conventional therapies is due to the presence of cancer stem-like cells. These cells could recapitulate some signaling pathways important for embryonic development, such as Sonic hedgehog. Here, we investigated if the inhibitor of the Sonic hedgehog pathway, cyclopamine, could potentiate the temozolomide effect in cancer stem-like cells and glioblastoma cell lines in vitro. Main methodsThe viability of glioblastoma cells exposed to cyclopamine and temozolomide treatment was evaluated by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay while the induction of apoptosis was assessed by western blot. The stemness properties of glioma cells were verified by clonogenic and differentiation assay and the expression of stem cell markers were measured by fluorescence microscopy and western blot. Key findingsThe glioblastoma viability was reduced by cyclopamine treatment. Cyclopamine potentiated temozolomide treatment in glioblastoma cell lines by inducing apoptosis through activation of caspase-3 cleaved. Conversely, the combined treatment of cyclopamine and temozolomide potentiated the stemness properties of glioblastoma cells by inducing the expression of SOX-2 and OCT-4. SignificanceCyclopamine plays an effect on glioblastoma cell lines but also sensibilize them to temozolomide treatment. Thus, first-line treatment with Sonic hedgehog inhibitor followed by temozolomide could be used as a new therapeutic strategy for glioblastoma patients.

cancer biology↗

bioRxiv2020

Membrane Elastic Properties During Neural Progenitor/Neural Stem Cell Differentiation

Neural stem cells differentiate into several cell types that display distinct functions. However, little is known about how cell surface mechanics vary during the differentiation process. Here, by precisely measuring membrane tension and bending modulus, we map their variations and correlate them with changes in cell morphology along differentiation into neurons, astrocytes and oligodendrocytes. Both neurons and undifferentiated cells reveal a decrease in membrane tension over the first hours of differentiation followed by stabilization, with no change in bending modulus. Astrocytes membrane tension initially decreases and then increases after 72h, accompanied by consolidation of GFAP expression and striking actin reorganization, while bending modulus increases following observed alterations. For oligodendrocytes, the changes in membrane tension are less abrupt over the first hours but their values subsequently decrease, correlating with a shift from O4 to MBP expressions and a remarkable actin reorganization, while bending modulus remains constant. Oligodendrocytes at later differentiation stages show membrane vesicles with similar membrane tension but higher bending modulus as compared to the cell surface. Altogether, our results display an entire spectrum of how membrane elastic properties are varying, contributing to a better understanding of neural stem cell differentiation from a mechanobiological perspective.

biophysics↗