Biology subjects

Martin, A. J. M.

Publications and source records attributed to Martin, A. J. M..

2 recordsLinked to original sources

bioRxiv2021

Comparative and systems analyses of Leishmania spp. non-coding RNAs through developmental stages

Leishmania spp. is the etiological agent of leishmaniases, neglected diseases that seek to be eradicated in the coming years. The life cycle of these parasites involve different host and stress environments. In recent years, many studies have shown that several protein coding genes are directly involved with the development and host interactions, however, little is still known about the role of ncRNAs in life cycle progression. In this study, we aimed to identify the genomic structure and function of ncRNAs from Leishmania spp. and to get insights into the RNAome of this protozoan genus. We studied 26 strains corresponding to 16 different species of Leishmania. Our RNAome analysis revealed the presence of several ncRNAs that are shared through different species, allowing us to differentiate between subgenus as well as species that are canonically related to visceral leishmaniasis. We also studied co-expression relationships between coding genes and ncRNAs which in the amastigote developmental stage for Leishmania braziliensis and L. donovani revealed the presence of miRNA-like co-expressed with several coding genes involved in starvation, survival and histone modification. This work constitutes the first effort to characterize the Leishmania RNAome, supporting further approaches to better understand the role of ncRNAs in the gene regulation, infective process and host-parasite interaction.

genomics↗

bioRxiv2020

Enforced dimerization between XBP1s and ATF6f enhances the protective effects of the unfolded protein response (UPR) in models of neurodegeneration

Alteration to endoplasmic reticulum (ER) proteostasis is observed on a variety of neurodegenerative diseases associated with abnormal protein aggregation. Activation of the unfolded protein response (UPR) enables an adaptive reaction to recover ER proteostasis and cell function. The UPR is initiated by specialized stress sensors that engage gene expression programs through the concerted action of the transcription factors ATF4, ATF6f, and XBP1s. Although UPR signaling is generally studied as unique linear signaling branches, correlative evidence suggests that ATF6f and XBP1s may physically interact to regulate a subset of UPR-target genes. Here, we designed an ATF6f-XBP1s fusion protein termed UPRplus that behaves as a heterodimer in terms of its selective transcriptional activity. Cell-based studies demonstrated that UPRplus has stronger an effect in reducing the abnormal aggregation of mutant huntingtin and alpha-synuclein when compared to XBP1s or ATF6 alone. We developed a gene transfer approach to deliver UPRplus into the brain using adeno-associated viruses (AAVs) and demonstrated potent neuroprotection in vivo in preclinical models of Parkinsons and Huntingtons disease. These results support the concept where directing UPR-mediated gene expression toward specific adaptive programs may serve as a possible strategy to optimize the beneficial effects of the pathway in different disease conditions.

neuroscience↗