Biology subjects

Franca, S. C.

Publications and source records attributed to Franca, S. C..

3 recordsLinked to original sources

bioRxiv2021

Drug repurposing to face Covid-19: Celastrol, a potential leading drug capable of inhibiting SARS-CoV-2 replication and induced inflammation

The global emergence of Covid-19 has caused huge human casualties. Clinical manifestations of the disease vary from asymptomatic to lethal, and the symptomatic form can be associated with cytokine storm and non-homeostatic inflammatory response. In face of the urgent demand for effective drugs to treat Covid-19, we have searched for candidate compounds using a drug repurposing approach based on in silico analysis followed by biological validation. Here we identified celastrol, a pentacyclic triterpene isolated from Tripterygium wilfordii Hook F - a plant used in traditional Chinese medicine - as one of the best compounds out of 39 repurposed drug candidates. Celastrol reverted gene expression signature from SARS-CoV-2-infected cells; bound with high-affinity energy to viral molecular targets such as main protease (Mpro) and receptor-biding domain (RBD); inhibited SARS-CoV-2 replication in monkey (Vero and Vero-ACE2) and human (Caco-2 and Calu-3) cell lines; and decreased interleukin-6 (IL-6) secretion in SARS-CoV-2-infected human cell lines. Interestingly, celastrol acted in a concentration-dependent manner, with undetectable signs of cytotoxicity. Therefore, celastrol is a promising lead drug candidate to treat Covid-19 due to its ability to suppress SARS-CoV-2 replication and IL-6 production in infected cells, two critical events in the pathophysiology of this disease.

immunology↗

bioRxiv2020

Impact of a tarsonemid prey mite and its fungal diet on the reproductive performance of a predatory mite

Phytoseiid predatory mites are the most important group of biocontrol agents currently implemented in protected cultivations worldwide. The possibility to produce these predators at high densities on factitious prey mites is a crucial factor for their success. Commonly used factitious prey mites comprise mainly species belonging to the cohort of Astigmatina. In the present study, we investigated the potential of tarsonemid prey mites as a food source for the spider mite predator Neoseiulus californicus (McGregor) (Acari: Phytoseiidae). The oviposition of N. californicus on mixed stages of Tarsonemus fusarii Cooreman (Acari: Tarsonemidae) was similar to that on its natural prey, the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae). As most tarsonemids are specialized fungus-feeders, we tested the effect of different fungal species on the growth of T. fusarii. Subsequently, we analysed the impact on the fungal growing medium on the oviposition of N. californicus. The fungal growing medium of T. fusarii had a significant effect on the reproductive output of the predatory mite, having a negative effect. When T. fusarii was separated from the rearing medium, these detrimental effects were not observed. The present study shows the potential of using tarsonemid prey mites in the production of predatory mites.

ecology↗

bioRxiv2019

Microtranscriptome of contrasting sugarcane cultivars in response to aluminum stress

Although metallic elements are required for plant growth, aluminum ions (Al+3) can be considered one of the major abiotic factors affecting productivity. In plants, the presence of Al+3 can result in inhibition of root growth triggering water and nutrient deficiency. Plants under stress conditions undergo gene expression changes in specific genes or post-transcriptional gene regulators as miRNAs that can led to resistance. In this study, we investigated the miRNAs involved in the sugarcane response to aluminum stress. Four miRNA libraries were generated using sugarcane roots of two contrasting (tolerant and sensitive) sugarcane cultivars growing under aluminum stress to identify the miRNAs involved in the sugarcane response. Here we present the first miRNAs sequencing of sugarcane response under aluminum stress. The contrast of the cultivars seen in the field was reflected in the micro transcriptome with opposing expression profile. We selected 394 differentially expressed miRNAs, in both cultivars, 22% were common between cultivars. Real time quantitative polymerase chain reaction was used to validate the differentially expressed miRNAs through high-throughput sequencing in sugarcane roots. Target genes prediction was also analyzed. Our results indicated miRNAs that modulated specific target genes involved in roots development and plant aluminum stress response. Those genes can be the answer to tolerance in sugarcane and used in breeding programs to develop tolerant cultivars.

genomics↗