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Biology subjects

Ortez, C.

Publications and source records attributed to Ortez, C..

2 recordsLinked to original sources

Decoding Duchenne muscular dystrophy transcriptome to single nuclei level reveals clinical-genetic correlations

The cellular and molecular consequences of lack of dystrophin in humans are only partially known, which is crucial for the development of new therapies aiming to slow or stop the progression Duchenne and Becker muscular dystrophies. We analyzed muscle biopsies of DMD patients and controls using single nuclei RNA sequencing (snRNAseq) and correlated the results with clinical data. DMD samples displayed an increase in regenerative fibers, satellite cells and fibro-adipogenic progenitor cells (FAPs) and a decrease in slow fibers and smooth muscle cells. Samples from patients with stable mild weakness were characterized by an increase in regenerative fibers, while those from patients with progressive weakness had fewer muscle fibers and increased FAPs. DMD muscle fibers displayed a strong regenerative signature, while DMD FAPs upregulated genes producing extracellular matrix and molecules involved in several signaling pathways. An analysis of intercellular communication profile identified FAPs as a key regulator of cell signaling in DMD samples. We show significant differences in the gene expression profiled of the different cell populations present in DMD muscle samples compared to controls.

bioinformatics↗

Leptin protects against the development and expression of cocaine addiction-like behavior in heterogenous stock rats

In addition to its pleasurable effects, weight control is a significant contributor to initiation, maintenance and relapse of cocaine use. This suggests that individual differences in bodyweight control and feeding hormones, such as leptin may contribute to the vulnerability to cocaine use disorder. While pre-clinical studies have shown a mutually inhibitory relationship between leptin and cocaine, they have used small sample sizes and did not investigate individual differences in a large heterogeneous population. Here, we tested if individual differences in bodyweight and blood leptin level is associated with high or low vulnerability to addiction-like behaviors using data from 500 heterogenous stock rats and 160 blood samples from the Cocaine Biobank, using a model of extended access to intravenous self-administration of cocaine. Finally, we tested a separate cohort to evaluate the causal effect of exogenous leptin administration on cocaine seeking. Bodyweight, while changing due to cocaine self-administration in males, was not related to the vulnerability to addiction-like behavior. Blood leptin levels after ~6 weeks of cocaine self-administration did not correlate with addiction-like behaviors, however, baseline blood leptin levels before any access to cocaine negatively predicted addiction-like behavior. Finally, administration of leptin reduced cocaine intake after acute withdrawal and cocaine seeking after 6 weeks of protracted abstinence. These results demonstrate that high blood leptin level before access to cocaine may be a protective factor against the development of cocaine addiction-like behavior, that exogenous leptin reduces the motivation to take and seek cocaine, but that blood leptin level and bodyweight changes in current users are not good biomarkers for addiction-like behaviors.

physiology↗