Cytokines as biomarkers in depressive disorder: current standing and prospects.

The frequently observed co-occurrence of depressive disorders and inflammatory diseases suggests a close connection between the nervous and the immune systems. Increased pro-inflammatory and type 1 cytokines, such as interleukin (IL)-1, tumour necrosis factor (TNF)-α and interferon (IFN)-γ, appear to be an important link. Cytokines are synthesized by immune cells in the blood and peripheral tissues and by glial cells in the central nervous system (CNS). Evidence suggests that the blood-brain barrier (BBB) is permeable to cytokines and immune cells, and that afferent nerves, e.g. the vagus nerve, mediate the communication between peripheral inflammatory processes and CNS. Cytokines such as IL-1ß, TNF-α and IFN-γ seem to contribute to the pathophysiology of depression by activating monoamine reuptake, stimulating the hypothalamic-pituitary-adrenocortical (HPA) axis and decreasing production of serotonin due to increased activity of indolamine-2,3-dioxygenase (IDO). However, critical appraisal of these hypotheses is required, because cytokine elevation is not specific to depression. Moreover, several effective antidepressants such as amitriptyline and mirtazapine have been shown to increase cytokine production. When applying immunomodulatory therapies, these drugs may increase the risk of specific side effects such as infections or interact with antidepressant drugs on important functions of the body such as the coagulation system.

Stress, depression and antidepressant treatment options in patients suffering from multiple sclerosis.

Stress constitutes a risk factor for diseases where the immune system plays a significant role. Stress is recognized as a possible trigger for flare ups during the course of multiple sclerosis (MS). The disclosure to the patient of the diagnosis of MS, the commencement of immunomodulatory therapy, and the unpredictability and vagaries of disease progression are all sources of stress. Biological stress systems such as the hypothalamic-pituitary-adrenal system and the sympathetic nervous system may influence the pathogenesis and the disease course of MS. The ability to cope with stress may also be impaired, mediated for example by cognitive deficits or loss of abilities and resources as disease progresses or by the high prevalence of concurrent mood disturbances such as depression and chronic fatigue. Psychiatric comorbidities of MS disease or therapy as well as impairments of coping strategies are underrecognized in clinical practice. Treatment plans for depression among MS patients, as the most common psychiatric comorbidity, should be individualized with integrated approaches. Antidepressants are effective for the treatment of depression in MS patients although further clinical research into the neurobiological and psychological bases of depressive disorders in MS patients is clearly needed. In therapy, coping strategies can be enhanced through multidisciplinary assessment of the various challenges and restrictions imposed by the disease and assisting and supporting the patient in addressing these. Exercise, as a form of positive stress (eustress), also has a role in therapy.

Glucocorticoid induced expression of glutamine synthetase in hepatoma cells.

The enzyme glutamine synthetase (GS) ranks as one of the most remarkable glucocorticoid-inducible vertebrate genes. However, little is known about the responsible DNA elements and the mode of glucocorticoid action. This is especially the case for the induction of GS in hepatoma cells. In the work presented, the rat hepatoma cell line FAO was used as a model to study the induction of GS under the influence of glucocorticoids. FAO cells do not show GS activity in the absence of glucocorticoids and are strongly responding to their presence. Analyzing sequences of several thousand base pairs upstream and downstream from the transcriptional start point of the GS gene, a glucocorticoid responsible element was identified within the first intron of the gene. However, evidence is presented that aside from a primary effect on transcription glucocorticoids mediate their effect on the expression of GS also at the posttranscriptional level.