Biology subjects

Rodrigues, M. S.

Publications and source records attributed to Rodrigues, M. S..

6 recordsLinked to original sources

bioRxiv2024

Subcellular, biochemical and biophysical alterations in two glial cell models of ARSACS

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a developmental and degenerative disorder caused by loss-of-function mutations in the gene that codifies for the sacsin chaperone. Sacsin was initially described as a neuronal protein but is found in various cell types, including astroglial, microglial, kidney, and skin cell lines. We and others have shown that virtually all cell and animal models of ARSACS show disruption of intermediate filament (IF) cytoskeleton and organelle distribution. This article extends previous observations from our lab on the C6 astroglial-like model and describes the development and characterization of a new human microglial cell model based on HMC3 cells. HMC3 cells knocked out for sacsin show similar alterations to C6 astroglial-like cells: aberrant distribution of IF network and organelles, downregulation of developmental transcription factors STAT3 and Smad1, and alterations in autophagy machinery and markers of intracellular stress, resulting in morphological changes. Our results extend previous observations suggesting a possible role for glial cells in ARSACS and provide new tools to understand the glial-specific mechanisms involved in this pathology.

biochemistry↗

bioRxiv2022

TGF-β and BMP subfamily pathways in zebrafish spermatogonial niche: A83-01 and DMH1 inhibitor effects in spermatogonial self-renewal and differentiation

This study unravels the roles of TGF-{beta} (Transforming growth factor-{beta}) superfamily signaling pathway in the zebrafish spermatogonial activity (self-renewal vs. differentiation) by combining ex vivo and specific pathway inhibitors approaches. The TGF-{beta} superfamily signaling pathway is subdivided into TGF-{beta} and Bone morphogenetic proteins (BMP) subfamilies, and is ubiquitous among metazoans, regulating several biological processes, including spermatogenesis. In this study, we evaluated the function of the TGF-{beta} and BMP subfamily pathways in the zebrafish spermatogonial niche using A83-01 and DMH1 inhibitors, respectively. Our results showed that A83-01 potentiated the follicle-stimulating hormone (Fsh) effects on zebrafish spermatogenesis, reducing type A undifferentiated spermatogonia and increasing differentiated spermatogonia (type Adiff and type B spermatogonia) after 7 days of culture. In agreement with histomorphometrical data, the mRNA levels of dazl (marker of spermatogonial differentiation) and pro-differentiation growth factors, such as igf3 and insl3, were significantly augmented following A83-01. For the BMP signaling pathway, exposure to DMH1 inhibitor showed opposite effects as compared to TGF-{beta} superfamily signaling pathway inhibitor. Histomorphometrical analysis demonstrated an accumulation of type A undifferentiated spermatogonia, while the frequency of differentiated spermatogonia was significantly reduced following co-treatment of DMH1 with Fsh after 7 days of culture. To support this data, expression analysis revealed that BMP signaling pathway inhibitor also decreased the testicular mRNA levels of dazl, igf3 and insl3 when compared to control incubation (Fsh). In conclusion, our study demonstrated that TGF-{beta} and BMP subfamily pathways exert a role in zebrafish spermatogonial niche with antagonistic functions for the spermatogonia fate. The TGF-{beta} subfamily pathway is involved with spermatogonial self-renewal and inhibition of differentiation, whereas the BMP subfamily pathway promotes spermatogonial differentiation. These findings are not only relevant to understanding stem cell biology, but may also be useful in several in vitro assays, promoting control of self-renewal and differentiation by potentially directing these processes.

cell biology↗

bioRxiv2022

Thyroid hormones deficiency impairs male germ cell development: a cross talk between hypothalamic-pituitary-thyroid, and - gonadal axes in zebrafish

In vertebrates, thyroid hormones, including thyroxine (T4) and triiodothyronine (T3), are critical players in controlling different physiological processes such as development, growth, metabolism among others. There is evidence in mammals that thyroid hormones are also an important component of the hormonal system that controls reproduction, although studies in fish remain poorly investigated. Here we tested this hypothesis by investigating the effects of methimazole-induced hypothyroidism on the testicular function in adult D. rerio. Treatment of fish with methimazole, in vivo, significantly affected the progression of zebrafish spermatogenesis by inducing the accumulation of pre-meiotic cells, delaying cell differentiation and meiosis, as well as reducing the number of spermatozoa. The observed impairment of spermatogenesis by methimazole was correlated with significant changes in transcript levels for several genes involved in the control of reproduction. Using an in vitro approach, we also demonstrated that in addition to affecting the components of the brain-pituitary-peripheral axis, T3 also exerts direct action at the level of the testis. These results support the hypothesis that thyroid hormones are an essential component of multifactorial control of reproduction and testicular function in zebrafish and possibly other vertebrates.

cell biology↗

bioRxiv2021

Gdnf, a germ cell-derived factor, regulates zebrafish germ cell stemness through the creation of new spermatogonial niches (germ and Sertoli cells) and inhibition of spermatogonial differentiation in an autocrine and paracrine manners

Glial cell line-derived neurotrophic factor (GDNF) and its receptor (GDNF Family Receptor 1 - GFR1) are well known to mediate spermatogonial stem cell (SSC) proliferation and survival in the mammalian testes. In nonmammalian species, Gdnf and Gfr1 orthologs have been found but their functions remain poorly investigated in the testis. Considering this background, this study aimed to understand the roles of Gdnf-Gfr1 signaling pathway in the zebrafish testis by combining in vivo, in silico and ex vivo approaches. Our analysis showed that zebrafish exhibited two paralogs of Gndf (gdnfa and gdnfb) and its receptor, Gfr1 (gfr1a and gfr1b), in agreement with the teleost-specific third round (3R) of whole genome duplication. Expression analysis further revealed that gdnfa and gfr1a were the most expressed copies in the zebrafish adult testes. Subsequently, we demonstrated that gdnfa is expressed in the germ cells, while Gfr1a was detected in early spermatogonia (mainly in types Aund and Adiff) and Sertoli cells. Functional ex vivo analysis showed that Gdnf promoted the creation of new available niches by stimulating proliferation of both type Aund spermatogonia and their surrounding Sertoli cells, but without changing pou5f3 mRNA levels. Strikingly, Gdnf also inhibited late spermatogonial differentiation as shown by the decrease of type B spermatogonia and down-regulation of dazl in the co-treatment with Fsh. Altogether, our data revealed for the first time that a germ cell-derived factor is associated with maintaining germ cell stemness through the creation of new available niches, supporting development of differentiating spermatogonial cysts and inhibiting late spermatogonial differentiation in autocrine and paracrine manners.

cell biology↗

bioRxiv2021

Interaction of thyroid hormones and gonadotropin inhibitory hormone in the multifactorial control of zebrafish (Danio rerio) spermatogenesis

Reproduction is under multifactorial control of neurohormones, pituitary gonadotropins, as well as a number of gonadal hormones including sex steroids and growth factors. Gonadotropin-inhibitory hormone (Gnih), a novel RFamide neuropeptide, was shown to be involved in the control of pituitary gonadotropin production, as well as being involved as a paracrine factor in the regulation of gonadal function. In this context, recent studies have demonstrated that Gnih inhibited gonadotropin-induced spermatogenesis in the zebrafish testicular explants. Thyroid hormones are known to interact with the reproductive axis, and are, in particular, involved in the regulation of testicular function. Based on this background, we investigated the interaction between Gnih and thyroid hormones in the control of zebrafish spermatogenesis. To this end, zebrafish adult males were treated with the goitrogen methimazole (1mM for 21 days) in order to generate a hypothyroid model organism. Subsequently, a factorial design using an ex vivo testis culture system in combination with histomorphometrical and FACScan cell cycle analyses were adopted. Our results showed that methimazole treatment affected both basal and gonadotropin-induced spermatogenesis, in particular, meiosis and spermiogenesis. Moreover, the goitrogen treatment nullified the inhibitory actions of Gnih on the gonadotropin-induced spermatogenesis, specifically in the haploid cell population. We have demonstrated that thyroid hormones interaction with gonadotropin and Gnih are important components for the regulation of zebrafish spermatogenesis. The results provide a support for the hypothesis that thyroid hormones are important contributors in multifactorial control of spermatogenesis in zebrafish.

cell biology↗

bioRxiv2019

Interdependence between confirmed and discarded cases of dengue, chikungunya and Zika viruses in Brazil: A multivariate time-series analysis

The co-circulation of different arboviruses in the same time and space poses a significant threat to public health given their rapid geographic dispersion and serious health, social, and economic impact. Therefore, it is crucial to have high quality of case registration to estimate the real impact of each arboviruses in the population. In this work, a Vector Autoregressive (VAR) model was developed to investigate the interrelationships between discarded and confirmed cases of dengue, chikungunya, and Zika in Brazil. We used data from the Brazilian National Notifiable Diseases Information System (SINAN) from 2010 to 2017. There were three peaks in the series of dengue notification in this period occurring in 2013, 2015 and in 2016. The series of reported cases of both Zika and chikungunya reached their peak in late 2015 and early 2016. The VAR model shows that the Zika series have a significant impact on the dengue series and vice versa, suggesting that several discarded and confirmed cases of dengue could actually have been cases of Zika. The model also suggests that the series of confirmed and discarded chikungunya cases are almost independent of the cases of Zika, however, affecting the series of dengue. In conclusion, co-circulation of arboviruses with similar symptoms could have lead to misdiagnosed diseases in the surveillance system. We argue that the routinely use of mathematical and statistical models in association with traditional symptom-surveillance could help to decrease such errors and to provide early indication of possible future outbreaks. These findings address the challenges regarding notification biases and shed new light on how to handle reported cases based only in clinical-epidemiological criteria when multiples arboviruses co-circulate in the same population. Author summaryArthropod-borne viruses (arboviruses) transmission is a growing health problem worldwide. The real epidemiological impact of the co-circulation of different arboviruses in the same urban spaces is a recent phenomenon and there are many issues to explore. One of them is the misclassification due to the scarce availability of confirmatory laboratory tests. This establishes a challenge to identify, distinguish and estimate the number of infections when different arboviruses co-circulate. We propose the use of multivariate time series analysis to understand how the weekly notification of suspected cases of dengue, chikungunya and Zika, in Brazil, affected each other. Our results suggest that the series of Zika significantly impact on the series of dengue and vice versa, indicating that several discarded and confirmed cases of dengue might actually have been Zika cases. The results also suggest that the series of confirmed cases of chikungunya are almost independent of those of dengue and Zika. Our findings shed light on yet hidden aspects on the co-circulation of these three viruses based on reported cases. We believe the present work provides a new perspective on the longitudinal analysis of arboviruses transmission and call attention to the challenge in dealing with biases in case notifications when multiple arboviruses circulate in the same urban environment.

epidemiology↗