What if the cold days return? Epigenetic mechanisms in plants to cold tolerance.

MAIN CONCLUSION: The epigenetic could be an important, but seldom assessed, mechanisms in plants inhabiting cold ecosystems. Thus, this review could help to fill a gap in the current literature. Low temperatures are one of the most critical environmental conditions that negatively affect the growth, development, and geographic distribution of plants. Exposure to low temperatures results in a suit of physiological, biochemical and molecular modifications through the reprogramming of the expression of genes and transcription factors. Scientific evidence shows that the average annual temperature has increased in recent years worldwide, with cold ecosystems (polar and high mountain) being among the most sensitive to these changes. However, scientific evidence also indicates that there would be specific events of low temperatures, due it is highly relevant to know the capacity for adaptation, regulation and epigenetic memory in the face of these events, by plants. Epigenetic regulation has been described to play an important role in the face of environmental stimuli, especially in response to abiotic stress. Several studies on epigenetic mechanisms have focused on responses to stress as drought and/or salinity; however, there is a gap in the current literature considering those related to low temperatures. In this review, we focus on systematizing the information published to date, related to the regulation of epigenetic mechanisms such as DNA methylation, histone modification, and non-coding RNA-dependent silencing mechanisms, in the face of plant´s stress due to low temperatures. Finally, we present a schematic model about the potential responses by plants taking in count their epigenetic memory; considering a global warming scenario and with the presence or absence of extreme specific events of low temperatures.

Relationship between SIRT1 gene expression level and disease in age-related cataract cases

Background/aim: Age-related cataract is the most important visual impairment all over the world. Epigenetic modifications, especially overexpression of histone deacetylases, have become the focus of interest for cataract development in recent years. Sirtuin 1 (SIRT1), a class II histone deacetylase and a member of the sirtuin family, is one of the best-characterized histone deacetylases and has a pivotal role in age-related diseases. However, the association of SIRT1 with age-related cataracts has not yet been fully elucidated. Therefore, we aimed to determine the expression of SIRT1 in age-related cataract patients. Materials and methods: Expressions of SIRT1 were evaluated by quantitative polymerase chain reaction (qPCR) in patients and healthy controls. RNA samples were collected from the anterior capsule and peripheral blood samples of age-related cataract patients. Human lens epithelial cell line B3 and peripheral blood samples of healthy subjects were used as controls. Results: We determined that the expression of SIRT1 in blood and anterior capsule samples increased significantly compared to the control group (P < 0.05). Conclusion: The expression level of SIRT1 plays a vital role in the development of age-related cataract and it can be used as a biomarker. Thus, SIRT1 inhibitors can be used in the treatment of age-related cataract disease.

Epigenetic Features in Uterine Leiomyosarcoma and Endometrial Stromal Sarcomas: An Overview of the Literature.

There is a consensus that epigenetic alterations play a key role in cancer initiation and its biology. Studies evaluating the modification in the DNA methylation and chromatin remodeling patterns, as well as gene regulation profile by non-coding RNAs (ncRNAs) have led to the development of novel therapeutic approaches to treat several tumor types. Indeed, despite clinical and translational challenges, combinatorial therapies employing agents targeting epigenetic modifications with conventional approaches have shown encouraging results. However, for rare neoplasia such as uterine leiomyosarcomas (LMS) and endometrial stromal sarcomas (ESS), treatment options are still limited. LMS has high chromosomal instability and molecular derangements, while ESS can present a specific gene fusion signature. Although they are the most frequent types of "pure" uterine sarcomas, these tumors are difficult to diagnose, have high rates of recurrence, and frequently develop resistance to current treatment options. The challenges involving the management of these tumors arise from the fact that the molecular mechanisms governing their progression have not been entirely elucidated. Hence, to fill this gap and highlight the importance of ongoing and future studies, we have cross-referenced the literature on uterine LMS and ESS and compiled the most relevant epigenetic studies, published between 2009 and 2022.

Acute Stress-Induced Epigenetic Modulations and Their Potential Protective Role Toward Depression.

Psychiatric disorders entail maladaptive processes impairing individuals' ability to appropriately interface with environment. Among them, depression is characterized by diverse debilitating symptoms including hopelessness and anhedonia, dramatically impacting the propensity to live a social and active life and seriously affecting working capability. Relevantly, besides genetic predisposition, foremost risk factors are stress-related, such as experiencing chronic psychosocial stress-including bullying, mobbing and abuse-, and undergoing economic crisis or chronic illnesses. In the last few years the field of epigenetics promised to understand core mechanisms of gene-environment crosstalk, contributing to get into pathogenic processes of many disorders highly influenced by stressful life conditions. However, still very little is known about mechanisms that tune gene expression to adapt to the external milieu. In this Perspective article, we discuss a set of protective, functionally convergent epigenetic processes induced by acute stress in the rodent hippocampus and devoted to the negative modulation of stress-induced immediate early genes (IEGs) transcription, hindering stress-driven morphostructural modifications of corticolimbic circuitry. We also suggest that chronic stress damaging protective epigenetic mechanisms, could bias the functional trajectory of stress-induced neuronal morphostructural modification from adaptive to maladaptive, contributing to the onset of depression in vulnerable individuals. A better understanding of the epigenetic response to stress will be pivotal to new avenues of therapeutic intervention to treat depression, especially in light of limited efficacy of available antidepressant drugs.

La vía de señalización Notch en el origen de algunas malformaciones congénitas / The Notch Signaling Pathway at the Origin of Some Congenital Malformations

La vía de señalización Notch desempeña un papel clave para regular el destino celular, crecimiento, proliferación y la muerte celular programada durante el desarrollo de organismos eucariotas. Esta vía está relacionada con una enorme diversidad de procesos del desarrollo y su disfunción está implicada en el origen de muchas malformaciones congénitas. Se realizó una revisión bibliográfica con el objetivo de actualizar la información sobre la vía de señalización Notch y su relación con el origen de diferentes malformaciones congénitas sensibles a la deficiencia materna de ácido fólico y otros micronutrientes. La literatura médica publicada en idiomas español e inglés se recopiló a través de buscadores como PubMed, Medline, Scielo, Lilacs y la biblioteca Cochrane en enero de 2018 usando palabras clave apropiadas. El conocimiento de esta vía de señalización podría ayudar a comprender mejor algunos aspectos de la morfogénesis, ya que, al actuar como un controlador maestro del destino celular, la proliferación, diferenciación y muerte celular programada, ofrece puntos específicos y susceptibles de intervención que posibilitan la prevención de determinadas malformaciones congénitas en el hombre(AU)

Notch signaling pathway plays a key role to regulate cell grow, fates, proliferation and programmed cell death in development of eukaryotic organisms. This pathway is related with an enormous diversity of developmental processes and its dysfunction is implicated in the origin of many congenital malformations. A review was performed to provide updated information on Notch signaling pathway involved in the origin of some congenital malformations related with maternal deficiency of folic acid and other micronutrients. Published medical literature in Spanish and English languages was retrieved from PubMed, Medline, Scielo, Lilacs and the Cochrane Library in January 2018, using appropriate key words. Knowledge about this signaling pathway could help to better understand some topics of morphogenesis, since by acting as a master controller of cell fate, proliferation, differentiation and programmed cell death, it offers susceptible and specific points which make possible to prevent some human congenital malformations(AU)