Biomedical subjects

Holger S Willenberg

Publications and source records attributed to Holger S Willenberg.

9 recordsLinked to original sources

PubMed2006

Corticotropin-releasing hormone receptor expression on normal and tumorous human adrenocortical cells.

Corticotropin-releasing hormone (CRH) is not only the principal regulator of the central hypothalamic-pituitary-adrenal (HPA) axis but also exerts direct actions on peripheral tissues. We analyzed the expression of CRH receptors in microdissected preparations of normal human adrenal glands and in adrenocortical and adrenomedullary tumors, employing immunohistochemistry, quantitative RT-PCR of microdissected adrenal tissues, and in situ hybridization. The effect of CRH on adrenal steroidogenesis was tested in adrenal cells. Immunoreactive CRH1R was found primarily within the zona reticularis. In addition, we found a higher expression of CRH type-1 and 2 receptors mRNAs in preparations of adrenal cortices as compared to pheochromocytomas, a 6-fold increase in preparations of clinically unapparent adrenocortical adenomas, and a 10- to 60-fold increase in cortisol-producing adrenal adenomas. Stimulation of the adrenal tumor cell line NCI-H295R with CRH elicited a 1.4-fold increase in DHEA secretion. This result could be reproduced in a culture of primary human adrenocortical cells. We conclude that adrenocortical cells exhibit a higher expression of functional CRH receptors than chromaffin cells and that CRH acts on adrenal DHEA production. The data support the assertion of a direct action of CRH on human adrenocortical cells in addition to an intra-adrenal CRH receptor/adrenocorticotropin system. Enhanced CRH1R expression may be involved in adrenocortical tumorigenesis.

Adrenal Cortex↗

PubMed2006

Hirsutism.

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Androgens↗

PubMed2006

Dendritic cells as potential adjuvant for immunotherapy in adrenocortical carcinoma.

OBJECTIVE: Adrenocortical carcinoma (ACC) is a rare malignancy associated with a dismal prognosis. Dendritic cells (DCs) are professional antigen-presenting cells leading to an antitumour immune response. The aim of this study was to elaborate two methods of antigen delivery to DCs and to evaluate an immunotherapy protocol in ACC patients. DESIGN/PATIENTS: Autologous DCs were pulsed with autologous tumour lysate (TL). Fusion of DCs with tumour cells was based on a polyethylene glycol method. Two patients with metastasized hypersecretory ACC were vaccinated twice. MEASUREMENTS: In vitro data were quantified by measurement of PBMC (peripheral blood mononuclear cell) responses and cytokine secretion and by flow cytometry analyses. Clinical response was monitored by CT scan of tumour mass and measurement of angiogenic factors. RESULTS: The maximum loading of TL was obtained at 24 h as 48.2% (+/- 26.8%) of DCs were TL-positive. The DC/tumour cell fusion efficacy was approximately 45% as shown by double positive staining for ACTH receptor and DC-specific CD83. In vivo DC vaccination resulted in positive delayed-type hypersensitivity skin reactions reflecting specific memory T-lymphocyte reaction. In vitro analyses revealed specific T-cell proliferation in patient 1 (stimulation index: 5.7 compared to pretreatment) and induction of cytotoxic granzyme B secreting T cells in patient 2 (0.41% CD8 + cells vs. 0.06% pretreatment) as indicators of specific cytotoxic T cells. Although angiogenic serum markers could be stabilized, no impact on tumour growth could be observed. CONCLUSION: Our data demonstrate that autologous dendritic cells induce antigen-specific Th1 immunity in adrenocortical carcinoma. The clinical outcome, however, was not improved in the patients studied here.

Adjuvants, Immunologic↗

PubMed2006

A case of catecholamine and glucocorticoid excess syndrome due to a corticotropin-secreting paraganglioma.

We present a case of a 61-year-old female patient with ectopic corticotropin (ACTH) syndrome, hypopituitarism, and catecholamine excess due to a paraganglioma at the inferior pole of the left kidney. In this article we discuss the hormonal findings in the patient and its consequences, the pitfalls of the endocrine workup, and the results of our immunohistological and molecular studies in more detail.

Adrenocorticotropic Hormone↗

PubMed2006

Expression of connexins in chromaffin cells of normal human adrenals and in benign and malignant pheochromocytomas.

Decrease in connexin (Cx) expression and loss of gap junctional intercellular communication (GJIC) have been associated with aberrant cell growth and enhanced neoplastic phenotype. We studied the expression of Cx26, Cx32, Cx43, and Cx50 in chromaffin cells of 10 normal human adrenal glands, 10 benign, and 13 malignant pheochromocytomas. Immunohistochemistry showed that Cx50 expression seemed to be the predominant form of Cx expressed in human chromaffin cells, whereas Cx43 immunoreactivity was the most prominent form found in the adrenal cortex. However, Western blotting revealed that nonphosphorylated and singly and doubly phosphorylated forms of Cx43 were present within the malignant adrenomedullary cells at the same time. Cx26 and Cx32 were distributed inhomogeneously with no emphasis of expression in the types of tissues studied. Cx50 expression was diminished in malignant pheochromocytomas. We conclude that there is a differential expression of Cx in human adrenals. Immunohistological testing for Cx expression does not however allow differentiation of benign from malignant pheochromocytomas.

Adrenal Gland Neoplasms↗

PubMed2004

Corticotropin-releasing hormone system in human adipose tissue.

Mounting evidence exists for a role of the CRH system in energy balance, including a direct influence on human adipocytes, the regulation of adipose 11 beta-hydroxysteroid dehydrogenase type 1 activity, and cortisol formation. We characterized the expression of CRH receptors 1 and 2 and CRH-like peptides stresscopin and urocortin in human adipose tissue in comparison with other peripheral tissues, adrenal, and heart. The effect of CRH on CRH receptor and CRH-like peptide expression was analyzed in isolated human adipocytes using quantitative TaqMan PCR. CRH receptors were detectable in fat tissue at mRNA and protein levels. CRH-R2 expression in fat was comparable with its expression in the heart, the organ with the highest CRH-R2 expression known. CRH-R1:CRH-R2 ratio varied according to fat-depot type; whereas CRH-R1 expression was higher in sc fat than in visceral fat, the opposite was true for CRH-R2. Adipose tissue also expressed urocortin and stresscopin, the predominant ligands of peripheral CRH-R2. CRH down-regulated CRH-R1 and CRH-R2 mRNA expression in isolated adipocytes. These data, together with the recently published observation that CRH regulates adipocyte metabolism by down-regulating 11 beta-hydroxysteroid dehydrogenase, indicate that a CRH system exists within human adipose tissue. This system could be implicated in energy homeostasis and in mediating the anorexic effects of CRH at adipose level.

Adipose Tissue↗

PubMed2003

Ectopic adrenocorticotropin (ACTH) and corticotropin-releasing hormone (CRH) production in the adrenal gland: basic and clinical aspects.

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.

Adrenal Cortex Neoplasms↗

PubMed2002

Use of laser microdissection in complex tissue.

Concomitant with the rapid development in biomedical knowledge, including the methods of molecular biology and proteomics, and the manufacture of ever more precise optical instruments, powerful lasers, and sophisticated microcomputing hardware and software, laser microdissection systems have emerged which are now entering the field of routine research. Today, several devices are commercially available, congresses devoted to the latest advances in laser microdissection are now held on regular occasions, and the number of publications based on the use of these techniques has risen to over 250. With laser microdissection, histological treatment, such as chemical or immunological fixation and staining, can readily be combined with methods suitable for molecular biology or proteomics. As the optical, technical, and methodological resolution of polymerase chain reaction (PCR) and microdissection increases, genetic and phenotypic studies of biological material are possible even at the level of single cells and subcellular elements. Moreover, questions such as the paracrine interaction of cells within complex tissues, the development of cancer, and the role of single cells in tissue remodeling or development on the microscopic and molecular level can now be addressed precisely at the molecular level. This chapter reviewed the development of laser microdissection platforms, its potential impact on the future of research, and how, in particular, these technologies can be successfully integrated into modern research and routine histopathological studies of complex tissue.

Animals↗

PubMed2002

Role of interleukin-6 in stress response in normal and tumorous adrenal cells and during chronic inflammation.

Interleukin-6 (IL-6) is the end-product of a cytokine signaling cascade and is secreted by specialized immune cells during inflammation. It has a great influence on many functions, including differentiation, stimulation, and activation of immune cells, or other cells of neuroendocrine origin. Thus, IL-6 serves as a key messenger in its communication with the neuroendocrine system, and serves as a potent activator of the hypothalamic-pituitary-adrenal axis at all levels. Changes in the levels of expression of this cytokine and its receptor have been observed during chronic inflammatory disease, and have been associated with tumorigenesis. Therefore, we studied the effect of IL-6 on normal and adenomatous human adrenal cells in vitro. The expression of IL-6 receptor mRNA was quantified within the same tissue. IL-6 potently stimulated cortisol secretion from dispersed normal human adrenal cells. We found immunoreactivity for the IL-6 receptor on cultured cells and paraffin-embedded sections of adrenal tissues. Further, there was a more pronounced expression of IL-6 mRNA in adrenal adenomas of patients with Cushing's syndrome, compared to normal human adrenals. Despite this fact, the sensitivity of cells of adenomatous adrenal glands to IL-6 was significantly decreased relative to cells from normal controls. These results were confirmed employing the permanent adrenocortical cancer cell line model NCI-H295. We infer that the loss of responsivity of tumorous adrenal cells to IL-6, and in part corticotropin, is an important step in the process of adrenal tumorigenesis by which regulation by differentiating proteins is bypassed.

Adenoma↗