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51.
DNA replication is a fundamental process of the cell that ensures accurate duplication of the genetic information and subsequent transfer to daughter cells. Various pertubations, originating from endogenous or exogenous sources, can interfere with proper progression and completion of the replication process, thus threatening genome integrity. Coordinated regulation of replication and the DNA damage response is therefore fundamental to counteract these challenges and ensure accurate synthesis of the genetic material under conditions of replication stress. In this review, we summarize the main sources of replication stress and the DNA damage signaling pathways that are activated in order to preserve genome integrity during DNA replication. We also discuss the association of replication stress and DNA damage in human disease and future perspectives in the field. 相似文献
52.
Hong Jun Jeon Young Rong Bang Hye Youn Park Seul A. Kim 《Chronobiology international》2017,34(6):677-686
Various physiological and psychological functions are influenced by circadian typology (CT), which was reported to be related to resilience. However, few studies have assessed the effects of CT in relation to resilience. The aim of the present study was to assess the influence of CT on sleep-related symptoms, physical fatigue and psychological well-being in relation to resilience. The present study included a total of 1794 healthy hospital employees, and they completed the Morningness–Eveningness Questionnaire, Connor–Davidson Resilience Scale, Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Fatigue Severity Scale, Hospital Anxiety and Depression Scale and World Health Organization Quality of Life Scale Abbreviated Version. Subjects with evening type showed lower sleep quality, more daytime sleepiness and physical fatigue than neither types and morning types. Additionally, evening types were more depressed and anxious and reported a poorer quality of life. CT was found to be a significant predictor of sleep quality, but CT was minimally associated with physical fatigue and psychological well-being in the regression analysis. Instead, resilience was substantially related to all of the variables measured. In conclusion, CT independently predicts sleep quality, but the effects of CT on physical fatigue and psychological well-being are negligible compared to those of resilience. 相似文献
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Agustin Guerrero-Hernández Daniel Leon-AparicioJesus Chavez-Reyes Jesus A. Olivares-ReyesSilvia DeJesus 《Cell calcium》2014
The endoplasmic reticulum is the main intracellular Ca2+ store for Ca2+ release during cell signaling. There are different strategies to avoid ER Ca2+ depletion. Release channels utilize first Ca2+-bound to proteins and this minimizes the reduction of the free luminal [Ca2+]. However, if release channels stay open after exhaustion of Ca2+-bound to proteins, then the reduction of the free luminal ER [Ca2+] (via STIM proteins) activates Ca2+ entry at the plasma membrane to restore the ER Ca2+ load, which will work provided that SERCA pump is active. Nevertheless, there are several noxious conditions that result in decreased activity of the SERCA pump such as oxidative stress, inflammatory cytokines, and saturated fatty acids, among others. These conditions result in a deficient restoration of the ER [Ca2+] and lead to the ER stress response that should facilitate recovery of the ER. However, if the stressful condition persists then ER stress ends up triggering cell death and the ensuing degenerative process leads to diverse pathologies; particularly insulin resistance, diabetes and several of the complications associated with diabetes. This scenario suggests that limiting ER stress should decrease the incidence of diabetes and the mobility and mortality associated with this illness. 相似文献
59.
D. Speijer G. R. Manjeri R. Szklarczyk 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2014,369(1646)
Oxygen radical formation in mitochondria is an incompletely understood attribute of eukaryotic cells. Recently, a kinetic model was proposed, in which the ratio between electrons entering the respiratory chain via FADH2 or NADH determines radical formation. During glucose breakdown, the ratio is low; during fatty acid breakdown, the ratio is high (the ratio increasing—asymptotically—with fatty acid length to 0.5, when compared with 0.2 for glucose). Thus, fatty acid oxidation would generate higher levels of radical formation. As a result, breakdown of fatty acids, performed without generation of extra FADH2 in mitochondria, could be beneficial for the cell, especially in the case of long and very long chained ones. This possibly has been a major factor in the evolution of peroxisomes. Increased radical formation, as proposed by the model, can also shed light on the lack of neuronal fatty acid oxidation and tells us about hurdles during early eukaryotic evolution. We specifically focus on extending and discussing the model in light of recent publications and findings. 相似文献
60.
A recent examination of color vision in the ringtail lemur produced evidence that these prosimians could make color discriminations consistent with a diagnosis of trichromatic color vision. However, it was unclear if this behavior reflected the presence of three classes of cone or whether lemurs might be able to utilize signals from rods in conjunction with those from only two classes of cone. To resolve that issue, spectral sensitivity functions were obtained from ringtail lemurs (Lemur catta) and brown lemurs (Eulemur fulvus) using a noninvasive electrophysiological procedure, electroretinographic flicker photometry. Results from experiments involving chromatic adaptation indicate that these lemurs routinely have only a single class of cone photopigment in the middle to long wavelengths (peak sensitivity of about 545 nm); they also have a short-wavelengthsensitive cone pigment with peak of about 437 nm. The earlier behavioral results are suggested to have resulted from the ability of lemurs to jointly utilize signals from rods and cones. The cone pigment complements of these lemurs differ distinctly from those seen among the anthropoids. © 1993 Wiley-Liss, Inc. 相似文献