Undervalued professionals: placement of nutritionist in the Ecuadorian health system

BACKGROUND

Currently, many public health issues are directly related to malnutrition, and are made worse by social inequities. Nutrition professionals must be a key player in improving epidemiological aspects of nutrition-related diseases and must be part of clinical teams to control nutritional concerns.

OBJECTIVE

To identify and analyze the nutritionists´ employment situation in Ecuador and areas of work covered and determine if type of university has an impact over work situation.

METHODOLOGY

A cross-sectional study was conducted, approved by the ethics committee of Universidad San Francisco de Quito. It included 442 nutritionists in Ecuador who graduated in 13 universities (5 private (PR) and 8 public (PU)) between 2008 and 2019. It implied an online survey that questioned their satisfaction with their education and current work situation. All the statistical analyses were performed using R version 4.0.3, two-sided weighted chi-square test was performed to estimate the difference between public and private university graduates, IC 95%, p between 0.01 and 0.05.

RESULTS

38,6% of participants are unemployed, 68,28% private university graduates (PR) are currently employed and 58.87% work as nutritionists, compared to 56,86% from a public university (PU) currently working and 44.69% working in the field. 76% have reported being unemployed at some point in their careers, being difficulty finding jobs the main reason. Regarding the professional field, most professionals have their own business, and the less common area of work was public and community nutrition. One third of the participants had another paid activity. The main salary is 800USD per month and graduated from PR perceived better salaries than from PU.

CONCLUSION

There is a lack of job opportunities for Ecuadorian nutritionists despite the high demand in every level of the health system. Most have been unemployed at some point in their careers due to difficulties finding jobs. There is a minimum nutrition staff working in community and public health nutrition.

Esrrb Regulates Specific Feed-Forward Loops to Transit From Pluripotency Into Early Stages of Differentiation

Characterization of pluripotent states, in which cells can both self-renew or differentiate, with the irreversible loss of pluripotency, are important research areas in developmental biology. Although microRNAs (miRNAs) have been shown to play a relevant role in cellular differentiation, the role of miRNAs integrated into gene regulatory networks and its dynamic changes during these early stages of embryonic stem cell (ESC) differentiation remain elusive. Here we describe the dynamic transcriptional regulatory circuitry of stem cells that incorporate protein-coding and miRNA genes based on miRNA array expression and quantitative sequencing of short transcripts upon the downregulation of the Estrogen Related Receptor Beta (Esrrb). The data reveals how Esrrb, a key stem cell transcription factor, regulates a specific stem cell miRNA expression program and integrates dynamic changes of feed-forward loops contributing to the early stages of cell differentiation upon its downregulation. Together these findings provide new insights on the architecture of the combined transcriptional post-transcriptional regulatory network in embryonic stem cells.

Alu retrotransposons modulate Nanog expression through dynamic changes in regional chromatin conformation via aryl hydrocarbon receptor

Transcriptional repression of Nanog is an important hallmark of stem cell differentiation. Chromatin modifications have been linked to the epigenetic profile of the Nanog gene, but whether chromatin organization actually plays a causal role in Nanog regulation is still unclear. Here, we report that the formation of a chromatin loop in the Nanog locus is concomitant to its transcriptional downregulation during human NTERA-2 cell differentiation. We found that two Alu elements flanking the Nanog gene were bound by the aryl hydrocarbon receptor (AhR) and the insulator protein CTCF during cell differentiation. Such binding altered the profile of repressive histone modifications near Nanog likely leading to gene insulation through the formation of a chromatin loop between the two Alu elements. Using a dCAS9-guided proteomic screening, we found that interaction of the histone methyltransferase PRMT1 and the chromatin assembly factor CHAF1B with the Alu elements flanking Nanog was required for chromatin loop formation and Nanog repression. Therefore, our results uncover a chromatin-driven, retrotransposon-regulated mechanism for the control of Nanog expression during cell differentiation.

Histone H4 acetylation regulates behavioral inter-individual variability in zebrafish

BACKGROUND

Animals can show very different behaviors even in isogenic populations, but the underlying mechanisms to generate this variability remain elusive. We use the zebrafish (Danio rerio) as a model to test the influence of histone modifications on behavior.

RESULTS

We find that laboratory and isogenic zebrafish larvae show consistent individual behaviors when swimming freely in identical wells or in reaction to stimuli. This behavioral inter-individual variability is reduced when we impair the histone deacetylation pathway. Individuals with high levels of histone H4 acetylation, and specifically H4K12, behave similarly to the average of the population, but those with low levels deviate from it. More precisely, we find a set of genomic regions whose histone H4 acetylation is reduced with the distance between the individual and the average population behavior. We find evidence that this modulation depends on a complex of Yin-yang 1 (YY1) and histone deacetylase 1 (HDAC1) that binds to and deacetylates these regions. These changes are not only maintained at the transcriptional level but also amplified, as most target regions are located near genes encoding transcription factors.

CONCLUSIONS

We suggest that stochasticity in the histone deacetylation pathway participates in the generation of genetic-independent behavioral inter-individual variability.