Biology subjects

Freire, C. M.

Publications and source records attributed to Freire, C. M..

3 recordsLinked to original sources

bioRxiv2025

Choice of lipid supplementation for in vitro erythroid cell culture impacts reticulocyte yield and characteristics

Lipids, particularly cholesterol, are critical components of red blood cell (RBC) membranes, influencing protein function, cell stability, and deformability. Reticulocytes (young RBC) derived from in vitro erythroid cultures have been reported to possess less cholesterol than their native counterparts, compromising their functional integrity and lifespan. However, variability in starting materials and culture protocols between studies has hindered deQnitive conclusions regarding the nature and consequences of this lipid deQciency. Here, we evaluated the influence of lipid sources on reticulocyte quality using a well-established CD34 erythroid culture system. We compared the use of human AB-serum and Octaplas (solvent/detergent-treated pooled plasma) as lipid sources. Our results reveal that detergent-treated plasma leads to cholesterol-deQcient reticulocytes with impaired characteristics, including reduced Qltration yield, heightened osmotic fragility, and altered PIEZO1 activity. In contrast, AB-serum supported the generation of functionally stable reticulocytes, with cholesterol supplementation required to rescue the defects observed with plasma. Importantly, this study provides the Qrst integrated lipidomic, metabolomic, and proteomic characterisation of in vitro-derived reticulocytes cultured under distinct lipid conditions. These multi-omic datasets offer new insights into the consequences of reduced lipid availability during erythroid culture and offer new insights into how culture media affects the development and functionality of lab grown blood.

cell biology↗

bioRxiv2023

Basigin mediation of Plasmodium falciparum red blood cell invasion does not require its interaction with monocarboxylate transporter 1

Plasmodium falciparum invasion of the red blood cell is reliant upon the essential interaction of PfRh5 with the host receptor protein basigin. Basigin exists as part of one or more multiprotein complexes, most notably through interaction with the monocarboxylate transporter MCT1. However, the potential requirement for basigin association with MCT1 and the wider role of basigin host membrane context and lateral protein associations during merozoite invasion has not been established. Using genetically manipulated in vitro derived reticulocytes, we demonstrate the ability to uncouple basigin ectodomain presentation from the transmembrane domain-mediated interaction with MCT1. Merozoite invasion of reticulocytes is unaffected by disruption of basigin MCT1 interaction and by removal or replacement of the basigin transmembrane helix. Therefore, presentation of the basigin ectodomain at the red blood cell surface, independent of its native association with MCT1 or other interactions mediated by the transmembrane domain, is sufficient to facilitate merozoite invasion.

cell biology↗

bioRxiv2018

Molecular dynamics suggests antiviral compounds active against Dengue Virus show similar binding patterns to Zika Virus proteins

The Zika virus (ZIKV) arrival in Brazilian territory brought to light the need for preparedness regarding arboviruses in Brazil. Compound screening is a cumbersome process dependent upon in vitro testing and validation. Recently, virtual screening methods have improved precision and reliability providing a framework for in silico testing of lead compound candidates. Here we have applied these methods on compounds that were previously shown to be active against Dengue virus in vitro, taking the structural information of such compounds and applying docking methods to identify putative binding sites. A molecular dynamics approach was also used to refine the docking results. The computational experiments ran here suggests that compounds such as Epigallocatechin Gallate, Ergotamine and Avermectin-B1a bind to active sites on the viral enzymes NS5 and NS3, as well as on its Envelope protein. Refinement shows that such bindings were not lost during the production run and key regions on both enzymes were structurally displaced on average over the simulation time. Interestingly there is no documented drug interactions among these candidates, raising the possibility of drug combinations during treatments. Moreover, the candidate compounds have been extensively studied, thus providing important information regarding intracellular interactions caused by them, which are also associated with pathways exploited by the virus, suggesting possible side interactions hindering the replication process.

microbiology↗