PubMed Health⌕ Search

Biomedical subjects

Rainer H Straub

Publications and source records attributed to Rainer H Straub.

At least 37 records · Page 2Linked to original sources
PubMed2005

Androgen conversion in osteoarthritis and rheumatoid arthritis synoviocytes--androstenedione and testosterone inhibit estrogen formation and favor production of more potent 5alpha-reduced androgens.

In synovial cells of patients with osteoarthritis (OA) and rheumatoid arthritis (RA), conversion products of major anti-inflammatory androgens are as yet unknown but may be proinflammatory. Therefore, therapy with androgens in RA could be a problem. This study was carried out in order to compare conversion products of androgens in RA and OA synoviocytes. In 26 OA and 24 RA patients, androgen conversion in synovial cells was investigated using radiolabeled substrates and analysis by thin-layer chromatography and HPLC. Aromatase expression was studied by immunohistochemistry. Dehydroepiandrosterone (DHEA) was converted into androstenediol, androstenedione (ASD), 16alphaOH-DHEA, 7alphaOH-DHEA, testosterone, estrone (E1), estradiol (E2), estriol (E3), and 16alphaOH-testosterone (similar in OA and RA). Surprisingly, levels of E2, E3, and 16alpha-hydroxylated steroids were as high as levels of testosterone. In RA and OA, 5alpha-dihydrotestosterone increased conversion of DHEA into testosterone but not into estrogens. The second androgen, ASD, was converted into 5alpha-dihydro-ASD, testosterone, and negligible amounts of E1, E2, E3, or 16alphaOH-testosterone. 5alpha-dihydro-ASD levels were higher in RA than OA. The third androgen, testosterone, was converted into ASD, 5alpha-dihydro-ASD, 5alpha-dihydrotestosterone, and negligible quantities of E1 and E2. 5alpha-dihydrotestosterone was higher in RA than OA. ASD and testosterone nearly completely blocked aromatization of androgens. In addition, density of aromatase-positive cells and concentration of released E2, E3, and free testosterone from superfused synovial tissue was similar in RA and OA but estrogens were markedly higher than free testosterone. In conclusion, ASD and testosterone might be favorable anti-inflammatory compounds because they decrease aromatization and increase anti-inflammatory 5alpha-reduced androgens. In contrast, DHEA did not block aromatization but yielded high levels of estrogens and proproliferative 16alpha-hydroxylated steroids. Androgens were differentially converted to pro- and anti-inflammatory steroid hormones via diverse pathways.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2005

Human hair follicles display a functional equivalent of the hypothalamic-pituitary-adrenal axis and synthesize cortisol.

The skin and its major appendages are prominent target organs and potent sources of key players along the classical hypothalamic-pituitary axis, such as corticotropin releasing hormone (CRH), adrenocorticotropic hormone (ACTH), and alpha melanocyte stimulating hormone (alpha-MSH), and even express key steroidogenic enzymes. Therefore, it may have established local stress response systems that resemble the hypothalamic-pituitary-adrenal (HPA) axis. However, functional evidence that this is indeed the case in normal human skin in situ has still been missing. We show that microdissected, organ-cultured human scalp hair follicles respond to CRH stimulation by up-regulating proopiomelanocortin (POMC) transcription and immunoreactivity (IR) for ACTH and alpha-MSH, which must have been processed from POMC. CRH, alpha-MSH, and ACTH also modulate expression of their cognate receptors (CRH-R1, MC1-R, MC2-R). In addition, the strongest stimulus for adrenal cortisol production, ACTH, also up-regulates cortisol-IR in the hair follicles. Isolated human hair follicles secrete substantial levels of cortisol into the culture medium, and this activity is further up-regulated by CRH. CRH also modulates important functional hair growth parameters in vitro (hair shaft elongation, catagen induction, hair keratinocyte proliferation, melanin production). Finally, human hair follicles display HPA axis-like regulatory feedback systems, since the glucocorticoid receptor agonist hydrocortisone down-regulates follicular CRH expression. Thus, even in the absence of endocrine, neural, or vascular systemic connections, normal human scalp hair follicles directly respond to CRH stimulation in a strikingly similar manner to what is seen in the classical HPA axis, including synthesis and secretion of cortisol and activation of prototypic neuroendocrine feedback loops.

Adrenocorticotropic Hormone↗
PubMed2005

An opposing time-dependent immune-modulating effect of the sympathetic nervous system conferred by altering the cytokine profile in the local lymph nodes and spleen of mice with type II collagen-induced arthritis.

OBJECTIVE: The sympathetic nervous system (SNS) seems to play a proinflammatory role in the early asymptomatic phase of arthritis, but its role in the late stages of chronic arthritis is not well known. The purpose of this study was to examine the effects of the SNS on late-stage chronic arthritis in mice with type II collagen-induced arthritis (CIA). METHODS: We tested the effects of the SNS by ablating sympathetic nerves at different time points in mice with CIA. Early sympathectomy was performed 7 days before immunization. Late sympathectomy was performed on day 56. Cytokine stimulation assays were performed on local lymph node cells and spleen cells, and levels of interleukin-10 (IL-10), IL-4, tumor necrosis factor alpha (TNFalpha), and interferon-gamma (IFNgamma) were determined. RESULTS: Animals with CIA that underwent early sympathectomy showed significantly lower arthritis scores than the controls. In contrast, animals that underwent late sympathectomy had significantly increased arthritis scores compared with controls. On day 0, lymph node cells from animals subjected to early sympathectomy had increased levels of IL-10 and IL-4 and unchanged levels of TNFalpha and IFNgamma compared with those from untreated animals. This indicates an immune-stimulating property of the SNS in draining lymph nodes. On day 80, lymph node cells and spleen cells from animals subjected to late sympathectomy showed increased levels of TNFalpha and IFNgamma compared with those from nonsympathectomized controls with CIA. This indicates an immune-depressing property of the SNS in draining lymph nodes and spleen. Arthritis per se largely diminished sympathetic nerve fiber density in synovium on day 80 (P < 0.01). CONCLUSION: The effect of the SNS is bimodal, enhancing or depressing levels of proinflammatory and antiinflammatory cytokines. This feature is dependent on the time point of immune system activation and the respective compartment. The SNS supports inflammation during the asymptomatic phase of CIA, whereas it inhibits inflammation during the chronic symptomatic phase.

Animals↗
PubMed2005

Reduced capacity for the reactivation of glucocorticoids in rheumatoid arthritis synovial cells: possible role of the sympathetic nervous system?

OBJECTIVE: Cortisol, the biologically active glucocorticoid, is a major endogenous antiinflammatory factor in rheumatoid arthritis (RA). The aim of this study was to examine the local conversion of cortisol to biologically inactive cortisone and vice versa (the cortisol-cortisone shuttle) in RA and osteoarthritis (OA) patients. METHODS: Thin-layer chromatography and phosphorimaging were used to examine the cortisol-cortisone shuttle in mixed synovial cells. Double immunohistochemistry was used to assess the key enzymes 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) and 11beta-HSD2 and their possible cellular locations. RESULTS: Double immunohistochemistry demonstrated 11beta-HSD1/2+ macrophages in the sublining area. The ratio of 11beta-HSD2+ cells to 11beta-HSD1+ cells was significantly higher in RA than in OA patients. Cortisol was converted to inactive cortisone in mixed synovial cells from RA and OA patients, which was largely inhibited by carbenoxolone (11beta-HSD1 and 11beta-HSD2 inhibitor). Using metyrapone to inhibit the 11beta-HSD1 reducing reaction (cortisone --> cortisol), we demonstrated that the capacity for reactivation of cortisone to cortisol was significantly higher in OA than in RA patients. Although the capacity for the cortisone-cortisol shuttle was higher in synovial cells from less-inflamed OA tissue compared with inflamed RA tissue, it was obvious that synovial inflammation in RA, but not OA, was related positively to the reactivation of cortisone. This indicates that in RA, a cause other than typical inflammatory factors inhibits the reactivation of cortisone. Since isoproterenol and adenosine inhibited the cortisol-cortisone shuttle, the loss of sympathetic nerve fibers (loss of beta-adrenergic agonist and adenosine) may be the missing link that accounts for the increased cortisol-cortisone shuttle in RA. CONCLUSION: This study demonstrates a reduced capacity for local reactivation of cortisone in RA synovial cells. Since synthetic glucocorticoids also use this reactivation shuttle, the results also apply to therapeutic glucocorticoids. This defective reactivation of cortisone may be an important unrecognized pathophysiologic factor in RA.

Aged↗
PubMed2005

Tumor necrosis factor inhibits conversion of dehydroepiandrosterone sulfate (DHEAS) to DHEA in rheumatoid arthritis synovial cells: a prerequisite for local androgen deficiency.

OBJECTIVE: Use of anti-tumor necrosis factor (anti-TNF) antibody therapy in rheumatoid arthritis (RA) has expanded our understanding of possible mechanisms by which this treatment reduces inflammation. Beyond its effects on local immune responses, anti-TNF treatment may also modulate the local hormone supply. Because androgens are thought to inhibit immune responses, their presence in inflamed tissue is an additional important antiinflammatory factor. METHODS: We investigated conversion of the ubiquitous dehydroepiandrosterone sulfate (DHEAS), the biologically inactive precursor of DHEA, to the androgen DHEA in mixed synovial cells from patients with RA and patients with osteoarthritis (OA), making use of thin-layer chromatography and phosphorimaging. Using immunohistochemical analysis, we detected the key enzyme, steroid sulfatase. RESULTS: DHEAS-to-DHEA conversion in synovial cells from patients with RA was significantly lower than that in synovial cells from patients with OA (mean +/- SEM 3.3 +/- 0.5% versus 6.0 +/- 0.9% of applied (3)H-DHEAS per 10(6) synovial cells; P = 0.042). In RA, but not in OA, the level of converted (3)H-DHEA was inversely correlated with the density of synovial macrophages (for RA, R(rank) = -0.725, P = 0.005; for OA, R(rank) = 0.069, P not significant [NS]) and T cells (for RA, R(rank) = -0.621, P = 0.024; for OA, R(rank) = 0.247, P NS). Double immunohistochemistry analysis revealed that steroid sulfatase was located mainly in synovial macrophages but was also observed in fibroblasts. Neutralization of TNF largely up-regulated the conversion of DHEAS to DHEA in RA, but not in OA. A similar neutralizing effect was observed with polyclonal human immunoglobulins; this effect is most probably mediated via TNF neutralization at low TNF concentrations. CONCLUSION: These data indicate that TNF inhibits the conversion of DHEAS to DHEA in RA synovial cells. Because androgens are antiinflammatory mediators, TNF-induced inhibition of the local androgen supply is a supplementary proinflammatory factor. Consequently, anti-TNF strategies may also exert their positive effects by increasing tissue androgens.

Aged↗
PubMed2005

Neuroendocrine-immune aspects of accelerated aging in rheumatoid arthritis.

The normal process of aging brings about changes in immune function, hormonal status, overall metabolism, and enhanced occurrence of neuropsychiatric disorders. These alterations are also evident at an accelerating pace in chronic inflammatory diseases. Treatment with immunosuppressive therapeutics is often not sufficiently effective. Treating neuroendocrine-immune alterations to regain homeostasis might enhance remission inducing and maintaining effects. This paper summarizes the phenomena related to normal aging and related to chronic inflammatory disease. Furthermore, a multimodal concept is being proposed to control more effectively chronic inflammatory disease on a neuroendocrine-immune basis.

Aging↗
PubMed2005

Up-regulation of nNOS and associated increase in nitrergic vasodilation in superior mesenteric arteries in pre-hepatic portal hypertension.

BACKGROUND/AIMS: Splanchnic arterial vasodilation in portal hypertension has been attributed largely to vascular NO overproduction. Three NO-synthase (NOS) isoforms have been identified of which e(ndothelial)-NOS has been found up-regulated and i(nducible)-NOS not expressed in the splanchnic circulation in portal hypertension. So far, n(euronal)-NOS has not been investigated and hence, the current study evaluates nNOS-expression and nNOS-mediated vasorelaxation in a model of portal vein-ligated rats (PVL). METHODS: Mesenteric vasculature of PVL and sham rats was evaluated for nNOS-protein (immunohistochemically and Western blotting). In vitro perfused de-endothelialized mesenteric arterial vasculature was pre-constricted with norepinephrine (EC(80)) and tested for nNOS-mediated vasorelaxation by periarterial nerve stimulation (PNS, 2-12 Hz, 45V) before and after incubation with the NOS-inhibitor L-NAME (10(-4)M). RESULTS: nNOS was localized to the adventitia of the mesenteric arterial tree showing more intense staining and increased protein expression in PVL as compared to sham rats. PNS induced a frequency-dependent vasorelaxation, which was more pronounced in PVL rats. L-NAME abolished this difference in nerval-mediated vasorelaxation, the effect being significantly greater in PVL than in sham animals. CONCLUSIONS: Perivascular nNOS-protein expression is enhanced in mesenteric arteries in portal hypertension mediating an increased nerval NO-mediated vasorelaxation. This nNOS-derived NO overproduction may play an important role in the pathogenesis of arterial vasodilation in portal hypertension.

Animals↗
PubMed2005

Norepinephrine in mice inhibits secretion of splenic IL-6 during the dark period but stimulates its secretion in the light period--possible role of the corticosterone tone.

In early morning hours, a rise of serum cytokines such as IL-6 was described. This study aimed to find reasons for this phenomenon focussing on NE and corticosterone. Mouse spleen slices were electrically stimulated (ES) in a microsuperfusion chamber in order to release endogenous NE. ES inhibited IL-6 secretion when animals were sacrificed at 03:00 and 06:00 (both p<0.001) but it increased its secretion from spleen slice removed at 09:00 (p=0.026). Prior administration of corticosterone or the glucocorticoid antagonist RU486 abrogated these ES effects. Endogenous NE via alpha- and beta-adrenoceptors mediated this time-dependent differential effects. This study demonstrates that cooperation of endogenous NE and corticosterone are involved in a time-dependent fall or rise of splenic IL-6 secretion.

Adrenergic alpha-Antagonists↗
PubMed2005

Autonomic dysfunction in rheumatic diseases.

Patients who have rheumatic diseases often present with dysfunctions that are related to the autonomic nervous system (ANS) and are due to peripheral autonomic neuropathy or central changes. This article describes the prevalence of autonomic dysfunctions in patients who have rheumatic diseases. In the second part of this article, another form of ANS dysfunction-complex regional pain syndromes-is demonstrated. Clinically, these syndromes are characterized by pain (spontaneous, hyperalgesia, allodynia); active movement disorders, including an increased physiologic tremor, abnormal regulation of blood flow and sweating, edema of skin and subcutaneous tissues; and trophic changes of skin, appendages of skin, and subcutaneous tissues. In conclusion, this discussion shows that alterations of the ANS occur in rheumatic and related diseases, that these alterations may be involved in the pathogenesis of these diseases, and that we need more refined methods to study the changes that are related to the ANS.

Autonomic Dysreflexia↗
PubMed2005

Sympathetic neurotransmitters in joint inflammation.

This article demonstrates the dual pro- and anti-inflammatory role of the sympathetic nervous system (SNS) in inflammatory joint disease (IJD) by way of distinct adrenoceptors. The dual role of the SNS depends on involved compartments, timing of distinct effector mechanisms during the inflammatory process, availability of respective adrenoceptors on target cells, and an intricate shift from beta-to-alpha adrenergic signaling in the progressing course of the inflammatory disease (beta-to-alpha adrenergic shift). Additional critical points for the dual role of the SNS in inflammation are the underlying change of immune effector mechanisms during the process of disease progression and the behavior of sympathetic nerve fibers in inflamed tissue (nerve fiber loss). This is accompanied by a relative lack of anti-inflammatory glucocorticoids in relation to inflammation. In quintessence, in early stages of IJD, the SNS plays a predominantly proinflammatory role, whereas in late stages of the disease the SNS most probably exerts anti-inflammatory effects. Because patients who have rheumatoid arthritis most often present in the chronic phase of the disease, support of anti-inflammatory sympathetic pathways can be a promising therapeutic option.

Animals↗
PubMed2005

New Glucocorticoids on the Horizon: Repress, Don't Activate!

Glucocorticoids are highly effective drugs; their immunosuppressive and antiinflammatory actions are used in the treatment of many rheumatic and other inflammatory diseases. However, their use is sometimes considerably limited by numerous adverse reactions. For this reason, great efforts have been made in recent years to develop innovative glucocorticoids or glucocorticoid receptor ligands that have improved therapeutic effect/adverse reaction ratio. We summarize the position and critically discuss the following products that are currently under development: (1) selective glucocorticoid receptor agonists (SEGRA or dissociating glucocorticoids); (2) nitrosteroids; and (3) long-circulating liposomal glucocorticoids. Finally, we describe the state of research on membrane-bound glucocorticoid receptors as possible further targets for specific glucocorticoid actions.

Journal Article↗
PubMed2005

Sex hormone concentrations in patients with rheumatoid arthritis are not normalized during 12 weeks of anti-tumor necrosis factor therapy.

OBJECTIVE: Androgens such as dehydroepiandrosterone sulfate (DHEAS) and testosterone are markedly lower in postmenopausal women with rheumatoid arthritis (RA) than in controls. In contrast, compared to controls, serum levels of estrogens are normal or elevated in women with RA. Since tumor necrosis factor (TNF) alters production of these hormones, we investigated changes of these hormones during anti-TNF antibody (anti-TNF) therapy with adalimumab in longstanding RA. METHODS: In this longitudinal anti-TNF therapy study in 13 patients with long-standing RA without prior prednisolone (7 infusions of anti-TNF: Week 0, 2, 4, 6, 8, 10, and 12), we measured serum concentrations of interleukin 6 (IL-6), androstenedione, DHEA, DHEAS, free testosterone, estrone, and 17ss-estradiol. Levels of these hormones in patients were compared to serum levels of 31 age and sex matched healthy controls. RESULTS: Upon treatment with anti-TNF, there was an impressive decrease of clinical markers of inflammation, erythrocyte sedimentation rate, and serum levels of IL-6. Serum levels of DHEAS and free testosterone were markedly lower at baseline in patients compared to controls, but this did not change during anti-TNF therapy. Serum levels of DHEA and 17ss-estradiol were significantly elevated in patients compared to controls, but similarly, anti-TNF therapy did not change initially increased levels. Molar ratios of hormones, which reflect hormone shifts via converting enzymes, showed typical alterations at baseline, but did not change markedly during anti-TNF therapy. CONCLUSION: Longterm therapy with anti-TNF did not change altered serum levels of typical sex hormones in patients with RA, although baseline values were largely different. In patients with RA, this indicates that alterations of sex hormones and altered activity of respective converting enzymes are imprinted for a long-lasting period over at least 12 weeks.

Adalimumab↗
PubMed2005

New glucocorticoids on the horizon: repress, don't activate!

Glucocorticoids are highly effective drugs; their immunosuppressive and antiinflammatory actions are used in the treatment of many rheumatic and other inflammatory diseases. However, their use is sometimes considerably limited by numerous adverse reactions. For this reason, great efforts have been made in recent years to develop innovative glucocorticoids or glucocorticoid receptor ligands that have improved therapeutic effect/adverse reaction ratio. We summarize the position and critically discuss the following products that are currently under development: (1) selective glucocorticoid receptor agonists (SEGRA or dissociating glucocorticoids); (2) nitrosteroids; and (3) long-circulating liposomal glucocorticoids. Finally, we describe the state of research on membrane-bound glucocorticoid receptors as possible further targets for specific glucocorticoid actions.

Animals↗
PubMed2005

Immune status and risk for infection in patients receiving chronic immunosuppressive therapy.

OBJECTIVE: Chronic immunosuppressive therapy may be complicated by infections indicating a more or less profound immune defect. However, immune monitoring to estimate the risk for infection has so far not been performed routinely. The aim of this study was (1) to investigate the effects of commonly used immunosuppressive treatment regimens on lymphocyte subsets and cytokine release from stimulated whole blood cultures in patients with rheumatic or autoimmune diseases; and (2) to determine whether such measurements could be used as predictors of infection, and if so, to determine their predictive value for subsequent infectious complications. METHODS: Patients with various chronic inflammatory diseases (n = 97) treated with different immunosuppressive regimens and healthy controls (n = 36) were evaluated for T lymphocyte subsets and for cytokine release in whole blood cultures after stimulation with lipopolysaccharide (LPS) or phorbol myristate acetate (PMA) and ionomycin. RESULTS: Therapy with corticosteroids induced dose-dependent lymphocyte depletion. Concomitant application of cytotoxic disease modifying drugs and corticosteroids caused an additive effect on lymphocytopenia, but did not change CD4/CD8 ratio. Corticosteroid therapy was also associated with impaired cytokine release from mononuclear cells in whole blood assays after in vitro stimulation with LPS or PMA/ionomycin. Infections requiring hospitalization developed in 19 of 95 evaluable patients during an average followup period of 2.3 years. On logistic regression analysis, lymphocytopenia < 600/microl, in particular < 250 CD4+ T cells/microl, and therapy with corticosteroids > 10 mg prednisolone equivalent per day were predictive of infections. Multiple logistic regression analysis showed that T-helper lymphocytopenia < 250/microl was the best predictor for future infections, with a positive predictive value of 0.53 and a negative predictive value of 0.97. CONCLUSION: Patients receiving chronic immunosuppressive therapy can develop severe lymphopenia that involves all subsets. Monitoring T-helper cell counts may be useful to estimate the risk for subsequent infections in such patients.

Adrenal Cortex Hormones↗
PubMed2004

Increased prevalence of semaphorin 3C, a repellent of sympathetic nerve fibers, in the synovial tissue of patients with rheumatoid arthritis.

OBJECTIVE: The presence of selective sympathetic nerve repellents, i.e., semaphorins, may be responsible for the observed reduction of sympathetic innervation in the synovial tissue of patients with rheumatoid arthritis (RA). This study was undertaken to investigate the presence of different semaphorins in synovial tissue of patients with RA, patients with osteoarthritis (OA), and control subjects without inflammation. METHODS: In situ hybridizations with digoxigenin-labeled RNA probes directed against different semaphorins were performed. The presence of semaphorin 3C (S3C) in the synovial tissue of 10 RA, 10 OA, and 5 control subjects was investigated using a polyclonal antiserum directed against S3C. RESULTS: All in situ hybridizations revealed the presence of S3C messenger RNA, but no other investigated semaphorin (i.e., against primary afferent sensory nerve fibers), in the synovial tissue of RA and OA patients. Immunohistologic double staining demonstrated that macrophages and fibroblasts were positive for S3C protein. Quantitative analysis of S3C protein staining showed an increased density of S3C-positive cells in the synovial tissue of RA patients (mean +/- SEM 339 +/- 65 cells/mm(2)) in comparison with OA patients (168 +/- 27/mm(2); P = 0.031 versus RA) and controls (126 +/- 26/mm(2); P = 0.027 versus RA). Studies of the relationship between sympathetic nerve fiber density and S3C-positive cell density in the tissue of all patients showed that RA patients generally had lower densities of sympathetic nerve fibers and higher densities of S3C-positive cells than OA patients and control subjects. CONCLUSION: These findings suggest that S3C from macrophages and fibroblasts, which is selectively directed against sympathetic nerve fibers, could be one element responsible for reduced sympathetic innervation in RA tissue. The inability of sympathetic nerve fibers to reinnervate synovial tissue could contribute to the chronic nature of RA.

Adrenergic Fibers↗