Ilias Vrezas

Universitätsklinikum Düsseldorf, Düsseldorf, North Rhine-Westphalia, Germany

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Publications (5)6.66 Total impact

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    ABSTRACT: Innerhalb der Nebenniere besteht eine enge zelluläre Interaktion des adrenokortikalen und chromaffinen Zellsystems, wobei Störungen der Nebennierenrinde die Funktion des Nebennierenmarks beeinträchtigen und umgekehrt. Die intakte Kommunikation der beiden Systeme innerhalb der Nebenniere, aber auch die Wechselwirkung mit dem Gefäß- und Immunsystem, ist Voraussetzung für eine gute Funktion des gesamten Stresssystems. Außerdem trägt ein Ungleichgewicht dieser bidirektionalen Wechselwirkung zur Entstehung oder Verschlechterung einer Vielzahl pathologischer Zustände und Krankheitsbilder bei bzw. kann auch deren Folge sein.
    01/2006;
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    ABSTRACT: Cytokines interfere with steroidogenesis at the level of the adrenals, testes, and ovaries. Within the adrenal, macrophages, and lymphocytes, physiologically widely infiltrating the adrenal cortex, and adrenocortical, and chromaffin cells produce cytokines, as IL-1, IL-6, TNFalpha, leukemia inhibitory factor (LIF), and IL-18 which have a key role in the immune-adreno-cortical communication. In addition to cytokines interacting with adrenal function, cytokine independent mechanisms are responsible for a cell to cell-mediated immune regulation of the adrenal. The importance of this immune-endocrine cross-talk becomes evident in the case of autoimmune and inflammatory diseases being necessary for an adequate adrenal stress response. Secretory products of macrophages are involved in the regulation of steroidogenesis, Sertoli cell activity, and germ cell survival in the human testes. In rats, IL-1 is involved in the paracrine regulation of Leydig cell steroidogenesis. IL-6 has been suggested to exert adverse effects on the male reproductive function, inducing persistent testicular resistance to luteinizing hormone (LH) action and/or suppression of Leydig cell steroidogenesis. Cytokines such as IL-8 and MCP-1 (monocyte chemotactic protein-1) are involved in follicular development and atresia, ovulation, steroidogenesis, and corpus luteum function. In undifferentiated ovarian cells TNF and IL-1 inhibit steroidogenesis, whereas in differentiated ovaries these cytokines stimulate progesterone synthesis. Some ovarian cancer cells secrete TNF and IL-1 which stimulate growth of these cells. In conclusion, cytokines interact with steroidogenesis in a systemic and complex manner, influencing development, function, and hormone production of the adrenals, testes, and ovaries.
    Molecular and Cellular Endocrinology 03/2004; 215(1-2):135-41. · 4.04 Impact Factor
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    ABSTRACT: The hypothalamic-pituitary-adrenal (HPA) axis is integrated in the human stress system and controls the metabolism of many cell systems in the body. Therefore, hypofunction or hyperfunction of the HPA axis potentially threatens the life of the whole organism. Noncontrolled overproduction of its key regulators, CRH and ACTH, causes dysfunction of the stress system. Ectopic secretion of these compounds may be part of extraadrenal paraneoplastic syndromes caused by various benign or malignant tumors. However, ectopic ACTH and CRH may originate from the adrenal itself. A local CRH/ACTH system exists in the normal human adrenal medulla. Overproduction of CRH and ACTH has been documented in pheochromocytomas causing Cushing's syndrome. Finally, ectopic production of ACTH causing Cushing's syndrome has also been demonstrated in adrenocortical cells. This suggests a marked plasticity within the HPA axis and the neuroendocrine cell system.
    Microscopy Research and Technique 07/2003; 61(3):308-14. · 1.59 Impact Factor
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    ABSTRACT: We present a case of Cushing's syndrome in a 60-year old man. Abdominal imaging revealed a right adrenal mass. After confirmation of the diagnosis, the right adrenal gland was resected and revealed a tumor containing a combined myelolipoma and adenoma of the adrenal gland. After surgical removal of the adrenal mass, the symptoms and clinical signs of Cushing's syndrome resolved gradually. Immunohistochemical analysis of the adrenal adenoma specimens showed a high lymphocyte population, particularly within the myelolipoma, and an unusually marked intermingling of myelolipomatous and adrenocortical tumor cells. Adrenocortical clear cells were found in direct contact with T and B lymphocytes. Immune-endocrine mechanisms may have triggered the corticotropin-independent adrenal Cushing's syndrome in this patient.
    Endocrine Research 03/2003; 29(1):67-71. · 1.03 Impact Factor
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    ABSTRACT: Cytokines are able to interact directly with the hypothalamic–pituitary–adrenal (HPA) axis. On the level of the adrenal, immune cells infiltrating the gland can influence adrenocortical function by secreting cytokines. On the other hand, adrenal cells themselves produce cytokines, which act on the adrenal gland. In this context, cytokines and especially interleukin (IL)-1, IL-6, and tumor necrosis factor-α (TNF-α) seem to be important regulators of the HPA axis. Especially IL-6 has a great influence on many functions, including differentiation, stimulation, and activation of immune cells, or other cells of neuroendocrine origin. In addition to cytokines interacting with adrenal function, cytokine-independent mechanisms are also responsible for a cell-to-cell-mediated immune regulation of the adrenal. Furthermore, hypothalamic hormones, including corticotropin-releasing hormone (CRH) and vasopressin have also been identified as important modulators of HPA axis in physiological as well as pathological situations. The importance of this immune-endocrine crosstalk becomes more evident in cases of autoimmune and inflammatory diseases, where an adequate adrenal stress response is decisive for the survival of the organism.

Publication Stats

123 Citations
6.66 Total Impact Points

Institutions

  • 2003–2004
    • Universitätsklinikum Düsseldorf
      Düsseldorf, North Rhine-Westphalia, Germany
    • Heinrich-Heine-Universität Düsseldorf
      • Klinik für Endokrinologie, Diabetologie und Rheumatologie
      Düsseldorf, North Rhine-Westphalia, Germany