Biology subjects

Avila Lopez, J.

Publications and source records attributed to Avila Lopez, J..

3 recordsLinked to original sources

bioRxiv2025

In vivo inhibition of stearoyl-CoA desaturase modulates the hippocampal fatty acid profile and restores density of dendritic spines in the aggressive 5xFAD model of Alzheimer s disease

While alterations in brain lipids are a central feature of Alzheimers disease (AD), therapeutic strategies targeting brain lipid metabolism are still lacking. Prior preclinical work has shown that pharmacological inhibition of the fatty acid desaturase, stearoyl-CoA desaturase (SCD), leads to recovery of hippocampal synapses with associated improvements in learning and memory in the slow-progressing 3xTg AD mouse model. Here, we used the rapidly progressing, highly amyloidogenic 5xFAD AD model to further delve into the effect of the SCD inhibitor (SCDi) on AD-associated fatty acid alterations and synapse loss. Hippocampus, cortex and plasma samples were collected from male and female 5xFAD and non-carrier control mice for fatty acid profiling and assessment of disease hallmarks. Plaque pathology, gliosis, and fatty acid alterations that included an increase in the C16:1/C16:0 desaturation index, a measure of SCD enzymatic activity, were apparent in the female hippocampus at 5 months of age, with similar fatty acid changes appearing in males by 8 months. Intracerebroventricular infusion of SCDi via osmotic pump for 28 days in 5 months old female 5xFAD and NC mice modulated the SCD-related fatty acid disturbances as well as PUFA concentrations. Quantification of Golgi staining revealed an SCDi-induced recovery of dendritic spine density. The beneficial effects of SCDi treatment on fatty acid balance and hippocampal dendritic spines in this more aggressive amyloidogenic 5xFAD model further support SCD inhibition as a promising therapeutic avenue for AD.

neuroscience↗

bioRxiv2024

More is better: A simple antibody-based strategy for recovering all major mouse brain cell types from multiplexed single-cell RNAseq samples.

Single-cell RNA sequencing (scRNAseq) is a powerful yet costly technique for studying cellular diversity within the complexity of organs and tissues. Here, we sought to establish an effective multiplexing strategy for the adult mouse brain that could allow multiple experimental groups to be pooled into a single sample for sequencing, reducing costs, increasing data yield, and eliminating batch effects. We first describe an optimized cold temperature single-cell dissociation protocol that permits isolation of a high yield and viability of brain cells from the adult mouse. Cells isolated using this protocol were then screened by flow cytometry using a panel of antibodies, allowing identification of a single antibody, anti-Thy1.2, that can tag the vast majority of isolated mouse brain cells. We then used this primary antibody against a "universal" neural target, together with secondary antibodies carrying sample-specific oligonucleotides and the BD Rhapsody single-cell system and show that multiple adult mouse brain samples can be pooled into a single multiplexed run for scRNAseq. Bioinformatic analyses enable efficient demultiplexing of the sequenced pooled brain sample, with high tagging efficiency and precise annotation and clustering of brain cell populations. The efficiency and flexibility of the cell dissociation protocol and the two-step multiplexing strategy simplifies experimental design, optimizes reagent usage, eliminates sequencing batch effects and reduces overall experimental costs.

molecular biology↗

bioRxiv2023

Impact of in vivo cyclic reprogramming on the choroid plexus

In vivo reprogramming using the transient expression of Oct3/4, Sox2, Klf4 and c{square}Myc (OSKM) transcription factors can be used to induce tissue regeneration. A cyclic regime for short{square}term OSKM expression has been shown to promote regeneration of several organs however its impact on the brain remains largely unknown. We investigated the effects of a cyclic short-term OSKM expression on the choroid plexus (CP), a highly vascularized tissue found within the brain ventricles which is responsible for producing the cerebrospinal fluid (CSF). Transient reprogramming was done on 8-week-old mice carrying the polycistronic OSKM cassette under tetracycline operator (tetO) and confirmed the successful transient reprogramming. We then performed the analysis of the CP at cellular and molecular levels. The CP tissue exhibited minor morphological changes in height and area of epithelial cells. We did not observe any significant differences in the integrity of the brain-CSF barrier but noticed an increase of NKCC1 expression, a protein involved in CSF production. A whole transcriptome analysis (RNA-seq) was also carried on the tissue and showed no difference in gene expression after the transient reprogramming, at the exception of blood-related genes. Our results indicate that surprisingly the CP mainly remains insensible to in vivo transient reprogramming as only morphological and protein changes were observed in the tissue, suggesting that translational changes might be at stake during the reprogramming process but are not present at the transcriptomic level. Our results also highlight that more tailored strategies need to be developed for exploring the potential of CP reprogramming in regenerative medicine.

neuroscience↗