Biology subjects

Matos-Rodrigues, G. E.

Publications and source records attributed to Matos-Rodrigues, G. E..

3 recordsLinked to original sources

bioRxiv2020

ATRIP protects progenitor cells against DNA damage in vivo

The maintenance of genomic stability during the cell cycle of progenitor cells is essential for the faithful transmission of genetic information. Mutations in genes that ensure genome stability lead to human developmental syndromes. Mutations in Ataxia Telangiectasia and Rad3-related (ATR) or in ATR-interacting protein (ATRIP) lead to Seckel syndrome, which is characterized by developmental malformations and short life expectancy. While the roles of ATR in replicative stress response and chromosomal segregation are well established, it is unknown how ATRIP contributes to maintaining genomic stability in progenitor cells in vivo. Here, we generated the first mouse model to investigate ATRIP function. Conditional inactivation of Atrip in progenitor cells of the CNS and eye led to microcephaly, microphthalmia and postnatal lethality. To understand the mechanisms underlying these malformations, we used lens progenitor cells as a model and found that ATRIP loss promotes replicative stress and TP53-dependent cell death. Trp53 inactivation in Atrip-deficient progenitor cells rescued apoptosis but increased mitotic DNA damage and mitotic defects. Our findings demonstrate an essential role of ATRIP in preventing DNA damage accumulation during unchallenged replication.

cell biology↗

bioRxiv2019

PCR-based detection of Helicobacter spp. in mice from different animal houses in Rio de Janeiro, Brazil

Pathogenic microbial detection and control in breeding and experimental laboratory animal facilities is essential to guarantee animal welfare, data validity and reproducibility. Helicobacter spp. is known to severely affect mice health, mainly in immunocompromised strains, what may affect experimental outcomes. This study aimed to screen for Helicobacter spp. in mice from four different animal houses in Rio de Janeiro, Brazil using a PCR for 16S ribosomal RNA. A pair of primers was designed to specifically identify Helicobacter species that commonly infect laboratory mice. Following PCR reaction, the expected 375 base pairs (bp) amplification product was purified, sequenced and showed a 95% similarity when compared to deposited sequences of Helicobacter hepaticus and Helicobacter bilis. Then, the presence of Helicobacter spp. in both feces and intestines samples was analyzed. Helicobacter spp DNA was detected in 59.6% of the fecal and 70.17% of the intestine samples. Although Helicobacter spp screening is recommended by institutional animal health monitoring programs worldwide it is still not mandatory by Brazilian animal welfare regulation. Our study, the first to monitor Helicobacter species in laboratory mice in Brazil, demonstrates the possibility of using a low cost, rapid molecular diagnostic test to screen Helicobacter and highlights the importance of regular microbiological verification of mice used for research in Brazilian animal houses.

microbiology↗

bioRxiv2018

De novo genesis of retinal ganglion cells by targeted expression of KLF4 in vivo

Retinal ganglion cell (RGC) degeneration is a hallmark of glaucoma, the most prevalent cause of irreversible blindness. Thus, innovative therapeutic strategies are needed to protect and replace these projection neurons. It has been shown that endogenous glial cells of the retina, Muller cells, can be directly reprogrammed into late-born retinal interneurons. However, since RGCs are the first neurons born during development, the replacement of damaged RGCs requires the reprograming to an early neurogenic state. Here, we demonstrate that the pluripotency regulator Klf4 is sufficient to reprogram the potency of lineage-restricted retinal progenitor cells (RPCs) to generate RGCs in vivo. Transcriptome analysis disclosed that the overexpression of Klf4 induces crucial regulators of RGC competence and specification, including Atoh7 and Eya2. In contrast, loss-of-function studies in mice and zebrafish demonstrated that Klf4 is not essential for generation or differentiation of RGCs during retinogenesis. Nevertheless, induced RGCs (iRGCs) generated upon Klf4 overexpression migrate to the proper layer and project axons aligned with endogenous fascicles that reach the optic nerve head. Notably, iRGCs survive for up to 30 days after in vivo reprogramming. Finally, we demonstrate that Klf4 converts Muller cells into neurons that express markers of RGCs. Altogether, we identified Klf4 as a promising tool to reprogram retinal cells and regenerate RGCs in the mature retina.\n\nSignificance StatementCell fate determination is a key process for development, regeneration and for the design of therapeutic strategies that involve cellular reprogramming. This work shows that the manipulation of a single pluripotency regulator (Klf4) is sufficient to reprogram restricted progenitor cells in vivo. These reprogrammed progenitors reacquire the potency to generate retinal ganglion cells. Ganglion cell degeneration is the leading cause of irreversible blindness; therefore, manipulation of ganglion cell competence is of relevance for human health. Our findings point to Klf4 as a promising tool to develop therapeutic strategies for the replacement of damaged ganglion cells.

developmental biology↗