Chromatin dynamics and gene expression response to heat exposure in field-conditioned versus laboratory-cultured Nematostella vectensis

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Weizman, E., Rinsky, M., Simon-Blecher, N., Lampert-Karako, S., Yaron, O., Tarrant, A. M., & Levy, O. Chromatin dynamics and gene expression response to heat exposure in field-conditioned versus laboratory-cultured Nematostella vectensis. International Journal of Molecular Sciences, 22(14), (2021): 7454, https://doi.org/10.3390/ijms22147454.Organisms’ survival is associated with the ability to respond to natural or anthropogenic environmental stressors. Frequently, these responses involve changes in gene regulation and expression, consequently altering physiology, development, or behavior. Here, we present modifications in response to heat exposure that mimics extreme summertime field conditions of lab-cultured and field-conditioned Nematostella vectensis. Using ATAC-seq and RNA-seq data, we found that field-conditioned animals had a more concentrated reaction to short-term thermal stress, expressed as enrichment of the DNA repair mechanism pathway. By contrast, lab animals had a more diffuse reaction that involved a larger number of differentially expressed genes and enriched pathways, including amino acid metabolism. Our results demonstrate that pre-conditioning affects the ability to respond efficiently to heat exposure in terms of both chromatin accessibility and gene expression and reinforces the importance of experimentally addressing ecological questions in the field

SIRT6 Promotes Hepatic Beta-Oxidation via Activation of PPARα

The pro-longevity enzyme SIRT6 regulates various metabolic pathways. Gene expression analyses in SIRT6 heterozygotic mice identify significant decreases in PPARα signaling, known to regulate multiple metabolic pathways. SIRT6 binds PPARα and its response element within promoter regions and activates gene transcription. Sirt6+/− results in significantly reduced PPARα-induced β-oxidation and its metabolites and reduced alanine and lactate levels, while inducing pyruvate oxidation. Reciprocally, starved SIRT6 transgenic mice show increased pyruvate, acetylcarnitine, and glycerol levels and significantly induce β-oxidation genes in a PPARα-dependent manner. Furthermore, SIRT6 mediates PPARα inhibition of SREBP-dependent cholesterol and triglyceride synthesis. Mechanistically, SIRT6 binds PPARα coactivator NCOA2 and decreases liver NCOA2 K780 acetylation, which stimulates its activation of PPARα in a SIRT6-dependent manner. These coordinated SIRT6 activities lead to regulation of whole-body respiratory exchange ratio and liver fat content, revealing the interactions whereby SIRT6 synchronizes various metabolic pathways, and suggest a mechanism by which SIRT6 maintains healthy liver

SN 2010mb: Direct Evidence for a Supernova Interacting with a Large Amount of Hydrogen-free Circumstellar Material

We present our observations of SN 2010mb, a Type Ic supernova (SN) lacking spectroscopic signatures of H and He. SN 2010mb has a slowly declining light curve (LC) (~600 days) that cannot be powered by ^(56)Ni/^(56)Co radioactivity, the common energy source for Type Ic SNe. We detect signatures of interaction with hydrogen-free circumstellar material including a blue quasi-continuum and, uniquely, narrow oxygen emission lines that require high densities (~10^9 cm^(–3)). From the observed spectra and LC, we estimate that the amount of material involved in the interaction was ~3 M_☉. Our observations are in agreement with models of pulsational pair-instability SNe described in the literature

SN 2010MB: Direct Evidence for A Supernova Interacting with A Large Amount of Hydrogen-Free Circumstellar Material

We present our observations of SN 2010mb, a Type Ic supernova (SN) lacking spectroscopic signatures of H and He. SN 2010mb has a slowly declining light curve (LC) (~600 days) that cannot be powered by 56Ni/56Co radioactivity, the common energy source for Type Ic SNe. We detect signatures of interaction with hydrogen-free circumstellar material including a blue quasi-continuum and, uniquely, narrow oxygen emission lines that require high densities (~109 cm–3). From the observed spectra and LC, we estimate that the amount of material involved in the interaction was ~3 M ☉. Our observations are in agreement with models of pulsational pair-instability SNe described in the literature

Absolute versus Relative Income and Their Effect on Depression and Chronic Anxiety

We use a large survey on health conditions conducted in Israel to explore whether absolute and/or relative income has a moderating effect on depression and/or chronic anxiety. In contributing to the literature, we use diagnosis-based depression and/or anxiety instead of non-diagnosis terms, such as happiness or well-being. Under this framework, we found that all of the moderating effect of income should be attributed to relative income and especially to socioeconomic relative income. Thus, stressing social comparison, as opposed to inner comparison or habituation. These moderating effects, which are mostly found in middle-aged adults (ages 30 to 65), are robust to alternative specifications of different sampling of health conditions, numerous control variables and several subsamples divided by gender, age and religion. The results have important health policy implications regarding possible treatments. JEL Classifications: I14, D1, I3

Income and clinical depression versus non-clinical mental health: Same associations or different structures? A dissociation strategy using a national representative random survey based on EUROHIS (INHIS-2).

We use a unique, large survey on health conditions conducted in Israel (10,331 respondents, 52.8% females, mean age 49.8) to explore whether clinical determined depression and/or anxiety has different associations in compare to non-clinical determined terms such as mental health. We find that absolute income is significantly associated with a decrease in negative mental health but have no significant association with depression and/or anxiety prevalence, whereas relative income is significantly associated with a decrease in depression and/or anxiety prevalence but have no significant association with negative mental health. The two specifications differed also with respect to several important risk factors, including personal attributes such as being of African origin, of a non-Jewish Arab minority or divorced. However, they were similar with general characteristics, such as participation in sport and smoking activities, whether a person has children, age and gender. Our results put forth sever questions about the wide use of non-clinical mental health, happiness and wellbeing as a sole proxy for a person's true wellbeing or utility

Pax6 is required for normal cell-cycle exit and the differentiation kinetics of retinal progenitor cells.

The coupling between cell-cycle exit and onset of differentiation is a common feature throughout the developing nervous system, but the mechanisms that link these processes are mostly unknown. Although the transcription factor Pax6 has been implicated in both proliferation and differentiation of multiple regions within the central nervous system (CNS), its contribution to the transition between these successive states remains elusive. To gain insight into the role of Pax6 during the transition from proliferating progenitors to differentiating precursors, we investigated cell-cycle and transcriptomic changes occurring in Pax6 (-) retinal progenitor cells (RPCs). Our analyses revealed a unique cell-cycle phenotype of the Pax6-deficient RPCs, which included a reduced number of cells in the S phase, an increased number of cells exiting the cell cycle, and delayed differentiation kinetics of Pax6 (-) precursors. These alterations were accompanied by coexpression of factors that promote (Ccnd1, Ccnd2, Ccnd3) and inhibit (P27 (kip1) and P27 (kip2) ) the cell cycle. Further characterization of the changes in transcription profile of the Pax6-deficient RPCs revealed abrogated expression of multiple factors which are known to be involved in regulating proliferation of RPCs, including the transcription factors Vsx2, Nr2e1, Plagl1 and Hedgehog signaling. These findings provide novel insight into the molecular mechanism mediating the pleiotropic activity of Pax6 in RPCs. The results further suggest that rather than conveying a linear effect on RPCs, such as promoting their proliferation and inhibiting their differentiation, Pax6 regulates multiple transcriptional networks that function simultaneously, thereby conferring the capacity to proliferate, assume multiple cell fates and execute the differentiation program into retinal lineages

Early Detection of Preeclampsia Using Circulating Small non-coding RNA

Abstract Preeclampsia is one of the most dangerous pregnancy complications, and the leading cause of maternal and perinatal mortality and morbidity. Although the clinical symptoms appear late, its origin is early, and hence detection is feasible already at the first trimester. In the current study, we investigated the abundance of circulating small non-coding RNAs in the plasma of pregnant women in their first trimester, seeking transcripts that best separate the preeclampsia samples from those of healthy pregnant women. To this end, we performed small non-coding RNAs sequencing of 75 preeclampsia and control samples, and identified 25 transcripts that were differentially expressed between preeclampsia and the control groups. Furthermore, we utilized those transcripts and created a pipeline for a supervised classification of preeclampsia. Our pipeline generates a logistic regression model using a 5-fold cross validation on numerous random partitions into training and blind test sets. Using this classification procedure, we achieved an average AUC value of 0.86. These findings suggest the predictive value of circulating small non-coding RNA in the first trimester, warranting further examination, and lay the foundation for producing a novel early non-invasive diagnostic tool for preeclampsia, which could reduce the life-threatening risk for both the mother and fetus