Pheochromocytoma in rats with multiple endocrine neoplasia (MENX) shares gene expression patterns with human pheochromocytoma

Pheochromocytomas are rare neoplasias of neural crest origin arising from chromaffin cells of the adrenal medulla and sympathetic ganglia (extra-adrenal pheochromocytoma). Pheochromocytoma that develop in rats homozygous for a loss-of-function mutation in p27Kip1 (MENX syndrome) show a clear progression from hyperplasia to tumor, offering the possibility to gain insight into tumor pathobiology. We compared the gene-expression signatures of both adrenomedullary hyperplasia and pheochromocytoma with normal rat adrenal medulla. Hyperplasia and tumor show very similar transcriptome profiles, indicating early determination of the tumorigenic signature. Overrepresentation of developmentally regulated neural genes was a feature of the rat lesions. Quantitative RT-PCR validated the up-regulation of 11 genes, including some involved in neural development: Cdkn2a, Cdkn2c, Neurod1, Gal, Bmp7, and Phox2a. Overexpression of these genes precedes histological changes in affected adrenal glands. Their presence at early stages of tumorigenesis indicates they are not acquired during progression and may be a result of the lack of functional p27Kip1. Adrenal and extra-adrenal pheochromocytoma development clearly follows diverged molecular pathways in MENX rats. To correlate these findings to human pheochromocytoma, we studied nine genes overexpressed in the rat lesions in 46 sporadic and familial human pheochromocytomas. The expression of GAL, DGKH, BMP7, PHOX2A, L1CAM, TCTE1, EBF3, SOX4, and HASH1 was up-regulated, although with different frequencies. Immunohistochemical staining detected high L1CAM expression selectively in 27 human pheochromocytomas but not in 140 nonchromaffin neuroendocrine tumors. These studies reveal clues to the molecular pathways involved in rat and human pheochromocytoma and identify previously unexplored biomarkers for clinical use.

Impact of arterial injury on neointimal hyperplasia after implantation of drug-eluting stents in coronary arteries: an intravascular ultrasound study

Aims: We investigated the impact of arterial injury on neointimal hyperplasia following implantation of drug-eluting stents (DES). Methods and results: A total of 196 patients with 223 segments (sirolimus-eluting stents [SES]: 104, paclitaxel-eluting stents [PES]: 119) underwent intravascular ultrasound eight months after DES implantation. Arterial injury was defined as the balloon-to-artery ratio (BAR). Segments were categorised into two groups: high BAR defined as BAR>1.1 (120 segments), and low BAR defined as BAR ≤1.1 (103 segments). Baseline clinical characteristics were similar for both groups. Although reference vessel diameter was smaller, stent diameter, maximal balloon pressure and balloon diameter were higher in the high BAR compared with the low BAR group. Lumen (7.10±1.91 vs. 6.25±1.69, p=0.001), stent (7.31±1.95 vs. 6.41±1.80, p=0.001), and external elastic membrane (17.1±4.9 vs. 14.8±4.0, p<0.0001) areas (mm2) were higher, but neointimal hyperplasia (0.21±0.36 vs. 0.16±0.48, p=0.42) area (mm2) was similar in the high BAR compared with the low BAR group. Arterial injury as assessed by BAR was not associated with the amount of neointimal hyperplasia (R2=0.003, p=0.40). Conclusions: Arterial injury does not correlate with the amount of neointimal hyperplasia following DES implantation. Conventionally aggressive DES implantation techniques do not adversely affect long-term outcome with respect to restenosis. - See more at: http://www.pcronline.com/eurointervention/30th_issue/79/#sthash.1do4X31G.dpuf

Adrenal insufficiency after glucocorticoid withdrawal in children with rheumatic diseases

?Glucocorticoids (GCs) are often used for the treatment of rheumatic disorders. However, doses are prescribed, which may suppress the hypothalamic-pituitary-adrenal (HPA) axis. After GC withdrawal, recovery of the HPA axis may be delayed putting the patient at risk for adrenal insufficiency. We assessed adrenal function and factors influencing adrenal responsiveness after termination of GC therapy in paediatric patients with rheumatic diseases.

Role of AMP-activated protein kinase on steroid hormone biosynthesis in adrenal NCI-H295R cells

Regulation of human androgen biosynthesis is poorly understood. However, detailed knowledge is needed to eventually solve disorders with androgen dysbalance. We showed that starvation growth conditions shift steroidogenesis of human adrenal NCI-H295R cells towards androgen production attributable to decreased HSD3B2 expression and activity and increased CYP17A1 phosphorylation and 17,20-lyase activity. Generally, starvation induces stress and energy deprivation that need to be counteracted to maintain proper cell functions. AMP-activated protein kinase (AMPK) is a master energy sensor that regulates cellular energy balance. AMPK regulates steroidogenesis in the gonad. Therefore, we investigated whether AMPK is also a regulator of adrenal steroidogenesis. We hypothesized that starvation uses AMPK signaling to enhance androgen production in NCI-H295R cells. We found that AMPK subunits are expressed in NCI-H295 cells, normal adrenal tissue and human as well as pig ovary cells. Starvation growth conditions decreased phosphorylation, but not activity of AMPK in NCI-H295 cells. In contrast, the AMPK activator 5-aminoimidazole-4-carboxamide (AICAR) increased AMPKα phosphorylation and increased CYP17A1-17,20 lyase activity. Compound C (an AMPK inhibitor), directly inhibited CYP17A1 activities and can therefore not be used for AMPK signaling studies in steroidogenesis. HSD3B2 activity was neither altered by AICAR nor compound C. Starvation did not affect mitochondrial respiratory chain function in NCI-H295R cells suggesting that there is no indirect energy effect on AMPK through this avenue. In summary, starvation-mediated increase of androgen production in NCI-H295 cells does not seem to be mediated by AMPK signaling. But AMPK activation can enhance androgen production through a specific increase in CYP17A1-17,20 lyase activity.

Acute effects of intravenous heroin on the hypothalamic-pituitary-adrenal axis response: a controlled trial

Heroin dependence is associated with a stressful environment and with dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis. The present study examined the acute effects of intravenous heroin versus placebo on the HPA axis response in heroin-dependent patients. Twenty-eight heroin-dependent patients in heroin-assisted treatment and 20 age- and sex-matched healthy participants were included in a controlled trial in which patients were twice administered heroin or saline in a crossover design, and healthy controls were only administered saline. The HPA axis response was measured by adrenocorticotropic hormone (ACTH) levels and by cortisol levels in serum and saliva before and 20 and 60 minutes after substance administration. Craving, withdrawal, and anxiety levels were measured before and 60 minutes after substance application. Plasma concentrations of heroin and its main metabolites were assessed using high-performance liquid chromatography. Heroin administration reduces craving, withdrawal, and anxiety levels and leads to significant decreases in ACTH and cortisol concentrations (P < 0.01). After heroin administration, cortisol concentrations did not differ from healthy controls, and ACTH levels were significantly lower (P < 0.01). In contrast, when patients receive saline, all hormone levels were significantly higher in patients than in healthy controls (P < 0.01). Heroin-dependent patients showed a normalized HPA axis response compared to healthy controls when they receive their regular heroin dose. These findings indicate that regular opioid administration protects addicts from stress and underscore the clinical significance of heroin-assisted treatment for heroin-dependent patients.

Polymer stent coating for prevention of neointimal hyperplasia

AIMS: Restenosis has been the principal limitation of bare metal stents. Based upon the presumption that platelet and inflammatory cell recruitment initiate neointimal proliferation, we explored a novel polymer coating that reduces cell-stent interactions. The purpose of the present study was to investigate the effect of poly(L-lysine)-graft-poly(ethyleneglycol) (PLL-g-PEG) adsorbed to stent surfaces to reduce neointimal hyperplasia in the porcine restenosis model. METHODS AND RESULTS: Seven animals were instrumented each with 2 stainless steel stents (15 mm length, 2.5-3.5 mm diameter), randomly implanted in 1 major epicardial coronary artery. One stent was dip-coated with PLL-g-PEG, whereas the other stent served as the uncoated control stent. All animals were sacrificed after 6 weeks for histological examination. Neointimal hyperplasia was significantly less (-51%) in the PLL-g-PEG-coated stents (1.15 +/- 0.59 mm2) than in the uncoated control stents (2.33 +/- 1.01 mm2; p < 0.001). Conversely, lumen size was larger in the PLL-g-PEG-coated stents (2.91 +/- 1.17 mm2) than in the uncoated stents (2.04 +/- 0.64 mm2; p < 0.001). High magnification histomorphologic examination revealed no signs of inflammation or thrombus formation in either stent group. CONCLUSIONS: Polymeric steric stabilization of stents with PLL-g-PEG significantly reduces neointimal hyperplasia in the porcine restenosis model. Reduction of cell-stent interactions mediated by PLL-g-PEG appear to improve biocompatibility of stainless steel stents without evidence of adverse inflammatory or prothrombotic effects.

[Old and new interventional therapies in the treatment of symptomatic benign prostate hyperplasia (BPH)]

Benign Prostatic Hyperplasia is a common entity among the aging male population. Its prevalence is increasing with age and is around 80% in the over 80-years old. The androgen-estrogen ratio changes in favor of the estrogens, which leads to a growth of prostatic tissue, presenting histologically as hyperplasia. BPH can cause irritative or obstructive symptoms or both. Nowadays we speak of bladder storage or bladder voiding symptoms, summarised as LUTS (Lower Urinary Tract Symptoms). LUTS has a structural and a functional component, the structural being caused by the size of the adenoma itself the functional depending on the muscle tone of the bladder neck and the prostatic urethra. To investigate LUTS, we use validated symptom scores, sonography for residual urine and eventually a urodynamic evaluation. There are 3 grades of BPH. The indication for an interventional therapy is relative in BPH II, and absolute in BPH III. Prior to treatment, other diseases mimicking the same symptoms, have to be ruled out and adequatly treated. Electro-resection of the prostate (TUR-P) remains the standard therapy and the benchmark any new technology has to compete with. TUR-P has good short- and longterm results, but can be associated with a considerable perioperative morbidity, and the learning curve for the operator is long. The most promising of the newer techniques is the Holmium-Laser-Enucleation of the prostate (Laser-TUR-P), showing at least identical short- and median-term results, but a lower perioperative morbidity than TUR-P For several minimally-invasive techniques, indications are limited. TUMT TUNA, WIT and laser-coagulation all produce a coagulation necrosis of the prostatic tissue by thermic damage with secondary tissue shrinking. Urodynamic results however, are not comparable to TUR-P or Laser-TUR-P, and significantly more secondary interventions within 2 to 5 years are required. Minimal-invasive techniques present a favorable alternative for younger patients without complications of BPH, and for older patients with relevant comorbidities, and can usually be performed under local anaesthesia. The morbidity is low and further therapies remain possible later, if necessary.

The nuclear receptor LRH-1 critically regulates extra-adrenal glucocorticoid synthesis in the intestine

The nuclear receptor liver receptor homologue-1 (LRH-1, NR5A2) is a crucial transcriptional regulator of many metabolic pathways. In addition, LRH-1 is expressed in intestinal crypt cells where it regulates the epithelial cell renewal and contributes to tumorigenesis through the induction of cell cycle proteins. We have recently identified the intestinal epithelium as an important extra-adrenal source of immunoregulatory glucocorticoids. We show here that LRH-1 promotes the expression of the steroidogenic enzymes and the synthesis of corticosterone in murine intestinal epithelial cells in vitro. Interestingly, LRH-1 is also essential for intestinal glucocorticoid synthesis in vivo, as LRH-1 haplo-insufficiency strongly reduces the intestinal expression of steroidogenic enzymes and glucocorticoid synthesis upon immunological stress. These results demonstrate for the first time a novel role for LRH-1 in the regulation of intestinal glucocorticoid synthesis and propose LRH-1 as an important regulator of intestinal tissue integrity and immune homeostasis.

Dehydroepiandrosterone sulfate in the assessment of the hypothalamic-pituitary-adrenal axis

The role of dehydroepiandrosterone-sulfate (DHEA-S) in assessing the integrity of the hypothalamic-pituitary-adrenal (HPA) axis in patients with suspected insufficiency is uncertain.

Human adrenal corticocarcinoma NCI-H295R cells produce more androgens than NCI-H295A cells and differ in 3beta-hydroxysteroid dehydrogenase type 2 and 17,20 lyase activities

The human adrenal cortex produces mineralocorticoids, glucocorticoids, and androgens in a species-specific, hormonally regulated, zone-specific, and developmentally characteristic fashion. Most molecular studies of adrenal steroidogenesis use human adrenocortical NCI-H295A and NCI-H295R cells as a model because appropriate animal models do not exist. NCI-H295A and NCI-H295R cells originate from the same adrenocortical carcinoma which produced predominantly androgens but also smaller amounts of mineralocorticoids and glucocorticoids. Research data obtained from either NCI-H295A or NCI-H295R cells are generally compared, although for the same experiments no direct comparison between the two cell lines has been performed. Therefore, we compared the steroid profile and the expression pattern of important genes involved in steroidogenesis in both cell lines. We found that steroidogenesis differs profoundly. NCI-H295A cells produce more mineralocorticoids, whereas NCI-H295R cells produce more androgens. Expression of the 3beta-hydroxysteroid dehydrogenase (HSD3B2), cytochrome b5, and sulfonyltransferase genes is higher in NCI-H295A cells, whereas expression of the cytochrome P450c17 (CYP17), 21-hydroxylase (CYP21), and P450 oxidoreductase genes does not differ between the cell lines. We found lower 3beta-hydroxysteroid dehydrogenase type 2 but higher 17,20-lyase activity in NCI-H295R cells explaining the 'androgenic' steroid profile for these cells and resembling the zona reticularis of the human adrenal cortex. Both cell lines were found to express the ACTH receptor at low levels consistent with low stimulation by ACTH. By contrast, both cell lines were readily stimulated by 8Br-cAMP. The angiotensin type 1 receptor was highly expressed in NCI-H295R than NCI-H295A cells and angiotensin II stimulated steroidogenesis in NCI-H295R but not NCI-H295A cells. Our data suggest that comparative studies between NCI-H295A and NCI-H295R cells may help find important regulators of mineralocorticoid or androgen biosynthesis.

MR imaging of the adrenal glands: 1.5T versus 3T

MR imaging at 1.5T is considered the prime cross-sectional imaging modality for characterization of adrenal lesions. This is of utmost clinical importance, because non-functioning adenoma and adrenal metastasis are fairly common. The differentiation of these two tumor entities primarily is based on chemical shift imaging, also known as dual echo in-phase and opposed-phase imaging. At 3.0 T, the echo time pairs for in-phase and opposed-phase MR imaging need to be adjusted because the frequency difference is double that of standard 1.5T MR systems. Unfortunately, the acquisition of the first opposed-phase echo at 1.1 milliseconds and the first in-phase echo at 2.2 milliseconds within the same breath-hold requires unacceptably high receiver bandwidths at 3.0 T. Therefore, alternative data collection schemes have been implemented. This article reviews the current literature regarding adrenal imaging at 3.0 T with a focus on the chemical shift technique.

Effect of echo time pair selection on quantitative analysis for adrenal tumor characterization with in-phase and opposed-phase MR imaging: initial experience

PURPOSE: To determine the effect of two pairs of echo times (TEs) for in-phase (IP) and opposed-phase (OP) 3.0-T magnetic resonance (MR) imaging on (a) quantitative analysis prospectively in a phantom study and (b) diagnostic accuracy retrospectively in a clinical study of adrenal tumors, with use of various reference standards in the clinical study. MATERIALS AND METHODS: A fat-saline phantom was used to perform IP and OP 3.0-T MR imaging for various fat fractions. The institutional review board approved this HIPAA-compliant study, with waiver of informed consent. Single-breath-hold IP and OP 3.0-T MR images in 21 patients (14 women, seven men; mean age, 63 years) with 23 adrenal tumors (16 adenomas, six metastases, one adrenocortical carcinoma) were reviewed. The MR protocol involved two acquisition schemes: In scheme A, the first OP echo (approximately 1.5-msec TE) and the second IP echo (approximately 4.9-msec TE) were acquired. In scheme B, the first IP echo (approximately 2.4-msec TE) and the third OP echo (approximately 5.8-msec TE) were acquired. Quantitative analysis was performed, and analysis of variance was used to test for differences between adenomas and nonadenomas. RESULTS: In the phantom study, scheme B did not enable discrimination among voxels that had small amounts of fat. In the clinical study, no overlap in signal intensity (SI) index values between adenomas and nonadenomas was seen (P < .05) with scheme A. However, with scheme B, no overlap in the adrenal gland SI-to-liver SI ratio between adenomas and nonadenomas was seen (P < .05). With scheme B, no overlap in adrenal gland SI index-to-liver SI index ratio between adenomas and nonadenomas was seen (P < .05). CONCLUSION: This initial experience indicates SI index is the most reliable parameter for characterization of adrenal tumors with 3.0-T MR imaging when obtaining OP echo before IP echo. When acquiring IP echo before OP echo, however, nonadenomas can be mistaken as adenomas with use of the SI index value.

Cell cycle-dependent regulation of extra-adrenal glucocorticoid synthesis in murine intestinal epithelial cells

Glucocorticoids are anti-inflammatory steroids with important applications in the treatment of inflammatory diseases. Endogenous glucocorticoids are mainly produced by the adrenal glands, although there is increasing evidence for extra-adrenal sources. Recent findings show that intestinal crypt cells produce glucocorticoids, which contribute to the maintenance of intestinal immune homeostasis. Intestinal glucocorticoid synthesis is critically regulated by the transcription factor liver receptor homologue-1 (LRH-1). As expression of steroidogenic enzymes and LRH-1 is restricted to the proliferating cells of the crypts, we aimed to investigate the role of the cell cycle in the regulation of LRH-1 activity and intestinal glucocorticoid synthesis. We here show that either pharmacological or molecular modulation of cell cycle progression significantly inhibited expression of steroidogenic enzymes and synthesis of glucocorticoids in intestinal epithelial cells. Synchronization of intestinal epithelial cells in the cell cycle revealed that expression of steroidogenic enzymes is preferentially induced at the G(1)/S stage. Differentiation of immature intestinal epithelial cells to mature nonproliferating cells also resulted in reduced expression of steroidogenic enzymes. This cell cycle-related effect on intestinal steroidogenesis was found to be mediated through the regulation of LRH-1 transcriptional activity. This mechanism may restrict intestinal glucocorticoid synthesis to the proliferating cells of the crypts.