Lacking ARHGAP25 mitigates the symptoms of autoantibody-induced arthritis in mice.

Objective: Despite intensive research on rheumatoid arthritis, the pathomechanism of the disease is still not fully understood and the treatment has not been completely resolved. Previously we demonstrated that the GTPase-activating protein, ARHGAP25 has a crucial role in the regulation of basic phagocyte functions. Here we investigate the role of ARHGAP25 in the complex inflammatory process of autoantibody-induced arthritis.

Time restricted feeding modifies leukocyte responsiveness and improves inflammation outcome.

Time restricted eating, the dietary approach limiting food intake to a maximal 10-hour period of daytime is considered beneficial in metabolic dysfunctions, such as obesity and diabetes. Rhythm of food intake and parallel changes in serum nutrient levels are also important entrainment signals for the circadian clock, particularly in tissues involved in metabolic regulation. As both the metabolic state and the circadian clock have large impact on immune functions, we investigated in mice whether time restricted feeding (TRF) affects systemic inflammatory potential.

Association of Social Jetlag With Sleep Quality and Autonomic Cardiac Control During Sleep in Young Healthy Men.

Social jetlag (SJL), the difference in sleep timing between work and free days is a consequence of the discrepancy between the individual's circadian rhythm and the social clock. SJL is considered a chronic stress factor and has been linked to various health problems. In this field study, we examined for the first time the association between SJL and cardiac regulation during sleep.

Circadian regulation of neutrophils: Control by a cell-autonomous clock or systemic factors?

Background: The circadian time-measuring system enables the organism to anticipate and effectively respond to regular daily changes in the environment and is therefore a crucial factor of adaptation. A large body of epidemiological data underlines the circadian characteristics of human immune functions. Circadian control of neutrophil responsiveness contributes to daily changes in the pathology of both acute and chronic inflammation and may therefore time-dependently influence the outcome of therapeutic approaches.

The small G protein RAS2 is involved in the metabolic compensation of the circadian clock in the circadian model .

Accumulating evidence from both experimental and clinical investigations indicates a tight interaction between metabolism and circadian timekeeping; however, knowledge of the underlying mechanism is still incomplete. Metabolic compensation allows circadian oscillators to run with a constant speed at different substrate levels and, therefore, is a substantial criterion of a robust rhythm in a changing environment. Because previous data have suggested a central role of RAS2-mediated signaling in the adaptation of yeast to different nutritional environments, we examined the involvement of RAS2 in the metabolic regulation of the clock in the circadian model organism We show that, in a -deficient strain, the period is longer than in the control.

Circadian regulation of human peripheral neutrophils.

Neutrophils are the most abundant leukocytes in human blood. Beside being essential responders in bacterial and fungal infections, they also contribute to tissue reactions in many autoimmune and inflammatory diseases. Although several immune responses linked to neutrophil functions have been described to be rhythmic, the mechanism of the circadian regulation of these cells is still not understood.

Social jetlag negatively correlates with academic performance in undergraduates.

Discrepancies between sleep timing on workdays and weekends, also known as social jetlag (SJL), affect the majority of the population and have been found to be associated with increased health risk and health-impairing behaviors. In this study, we explored the relationship between SJL and academic performance in a sample of undergraduates of the Semmelweis University. We assessed SJL and other sleep-related parameters with the Munich ChronoType Questionnaire (MCTQ) (n = 753).

Reactive oxygen species can modulate circadian phase and period in Neurospora crassa.

Reactive oxygen species (ROS) may serve as signals coupling metabolism to other cell functions. In addition to being by-products of normal metabolism, they are generated at elevated levels under environmental stress situations. We analyzed how reactive oxygen species affect the circadian clock in the model organism Neurospora crassa.