Glucocorticoid dependency of surgical stress-induced FosB/DeltaFosB expression in the paraventricular and supraoptic nuclei of the rat hypothalamus

FosB is a member of the Fos family transcription factors. To determine whether FosB expression is regulated by glucocorticoids (GCs) in the hypothalamus, rats underwent sham adrenalectomy (sham-ADX) or bilateral ADX, and FosB/DeltaFosB (DeltaFosB, a truncated splice variant of FosB)-immunoreactivity (ir) was determined in the paraventricular nucleus (PVN) and supraoptic nucleus (SON). In the parvocellular division of the PVN (paPVN) and SON, FosB/DeltaFosB-immunoreactivity (ir) increased significantly following sham-ADX compared to naive rats, which was suppressed with either corticosterone (CORT) or dexamethasone (DEX). Following ADX, the increase in FosB/DeltaFosB-ir was much more prominent than that in the sham-ADX group, and the ADX-induced robust increase was suppressed by CORT or DEX, but not by aldosterone. Stressless removal of CORT from drinking water did not induce FosB/DeltaFosB-ir in either the PVN or SON, and thus the up-regulation of FosB/DeltaFosB-ir following ADX was dependent on the systemic stress associated with surgery. In the paPVN, the majority of corticotrophin-releasing hormone (CRH) neurones co-expressed FosB/DeltaFosB-ir following ADX, whereas, in the magnocellular division of the PVN, vasopressin (AVP) and oxytocin (OXT) neurones did not express FosB/DeltaFosB-ir. In the SON, approximately 40% of the AVP neurones co-expressed FosB/DeltaFosB-ir following ADX, but the OXT neurones were devoid of FosB/DeltaFosB-ir. In concert with these results obtained in vivo, DEX suppressed the forskolin-induced increase in FosB gene promoter activity in a homologous hypothalamic cell line. These results suggest that GCs may be a potent regulator of FosB/DeltaFosB expression, which is induced by stress, in hypothalamic neuroendocrine neurones.

First demonstration of electron scattering using a novel target developed for short-lived nuclei

We carried out a demonstrative electron scattering experiment using a novel ion-trap target exclusively developed for short-lived highly unstable nuclei. Using stable 133Cs ion as a target, this experiment completely mimicked electron scattering off short-lived nuclei. Achieving a luminosity higher than 10;{26} cm;{-2} s;{-1} with around only 10;{6} trapped ions on the electron beam, the angular distribution of elastic scattering was successfully measured. This experiment clearly demonstrates that electron scattering off rarely produced short-lived nuclei is practical with this target technique.

Involvement of regulatory elements on corticotropin-releasing factor gene promoter in hypothalamic 4B cells

INTRODUCTION

Corticotropin-releasing factor (CRF) plays a central role in controlling the hypothalamic-pituitary-adrenal (HPA) axis during stressful periods. CRF is synthesized and secreted in the hypothalamic paraventricular nucleus (PVN) in response to stress, and stimulates ACTH in the pituitary corticotrophs. ACTH stimulates the release of glucocorticoids from the adrenal glands, and glucocorticoids sequentially inhibit hypothalamic PVN production of CRF and pituitary production of ACTH. The effects of glucocorticoids on CRF gene regulation, however, are possibly tissue-specific since glucocorticoids stimulate CRF gene expression in the placenta and the bed nucleus of the stria terminalis, while they inhibit it in the hypothalamus.

METHODS AND RESULTS

In a hypothalamic cell line, 4B, we found that forskolin-stimulated CRF gene transcription was mediated by a functional cAMP-response element (CRE), which included -220 to -233 bp on the CRF 5'-promoter region. Protein kinase A, protein kinase C, and p38 mitogen-activated protein kinase pathways contributed to forskolin-induced transcriptional activity of CRF in hypothalamic 4B cells. Glucocorticoid-dependent repression of cAMP-stimulated transcriptional activity of CRF was localized to promoter sequences between -278 and -233 bp, which included a glucocorticoid regulatory element and a serum response element.

CONCLUSION

Taken together, these findings indicate that the regulatory elements, including CRE, negative glucocorticoid regulatory element, and a serum response element on the promoter, contribute to the regulation of CRF gene transcription in hypothalamic 4B cells.

Effects of combined PPARgamma and PPARalpha agonist therapy on reverse cholesterol transport in the Zucker diabetic fatty rat

AIM

We investigated the effects of the combined therapy of PPARgamma and PPARalpha agonists on HDL metabolism, especially concerning reverse cholesterol transport (RCT), using Zucker diabetic fatty rats (ZDF/Crl-Lepr fa rats) that are the rodent model for type 2 diabetes with obesity, hyperlipidaemia and insulin resistance.

METHODS

The ZDF rats were divided into four medicated groups as follows: pioglitazone as a PPARgamma agonist (5 mg/kg/day; P group, n = 6), fenofibrate as a PPARalpha agonist (30 mg/kg/day; F group, n = 6), both these medications (P + F group, n = 6) and no treatment (UNT group, n = 6). Non-diabetic rats (ZDF/GmiCrl-lean, CON group, n = 6) served as controls. We evaluated HDL particle size and messenger RNA (mRNA) levels of the following factors: liver X receptor alpha (L x R alpha), ATP-binding cassette A1 (ABCA1) and ABCG1 which are regulated by PPARs and are related to early stage RCT.

RESULTS

The significant increase in HDL particle size was demonstrated in rats of the F and P + F groups, although changes in plasma HDL-cholesterol levels were not significant. In accordance with this finding, mRNA levels of ABCG1 in the liver increased significantly.

CONCLUSIONS

These findings suggest the efficacy of combined therapy with PPARgamma and PPARalpha in improving lipid metabolism, partly through the enhanced RCT, and insulin resistance in type 2 diabetes mellitus.

Novel internal target for electron scattering off unstable nuclei

A novel internal target has been developed, which will make electron scattering off short-lived radioactive nuclei possible in an electron storage ring. An "ion trapping" phenomenon in the electron storage ring was successfully utilized for the first time to form the target for electron scattering. Approximately 7 x 10(6) stable 133Cs ions were trapped along the electron beam axis for 85 ms at an electron beam current of 80 mA. The collision luminosity between the stored electrons and trapped Cs ions was determined to be 2.4(8) x 10(25) cm(-2) s(-1) by measuring elastically scattered electrons.

Mycobacterium avium complex disease: prognostic implication of high-resolution computed tomography findings

To evaluate the prognostic implications of computed tomography (CT) findings in assessing responses to treatment in Mycobacterium avium complex (MAC) pulmonary disease without underlying lung disease, high-resolution (HR)CT findings were correlated based on the results of sputum conversion after anti-MAC therapy. A total of 59 patients underwent HRCT before treatment and the therapeutic efficacy was evaluated by the results of sputum conversion. Atelectasis, cavities and pleural thickening on HRCT were significantly more frequent and extensive among patients in the sputum nonconverted group than among those in the converted group. Furthermore, bronchiectasis was also significantly more extensive among patients in the nonconverted group, even though there was no significant difference in frequency between these two groups. These results suggest that high-resolution computed tomography findings are good predictors of response to treatment in Mycobacterium avium complex pulmonary disease.

The CYP2A6*4 allele is determinant of S-1 pharmacokinetics in Japanese patients with non-small-cell lung cancer

S-1 is an oral fluorouracil anticancer drug that contains the 5-FU prodrug tegafur. Tegafur has been shown to be converted enzymatically to 5-FU to exert its antitumor effect, and this conversion is principally catalyzed by CYP2A6. Forty-six non-small-cell lung cancer patients were enrolled. The frequencies of the CYP2A6*4C, CYP2A6*7, and CYP2A6*9 alleles were 17.4, 19.6, and 15.2%, respectively. In the S-1 pharmacokinetic analysis, the area under the concentration-time curve from 0 to 10 h (AUC(0-10)) ratios of 5-FU/tegafur showed large interindividual variabilities, ranging from 5.14 to 112.6. The AUC(0-10) for tegafur was 1.5-fold higher in patients with the CYP2A6*4C allele than in patients without the CYP2A6*4C allele P < 0.05). Furthermore, patients with the CYP2A6*4C allele had a significantly lower maximum plasma concentration (102.6 +/- 32.9 ng/ml) for 5-FU than patients without the CYP2A6*4C allele (157.0 +/- 65.5 ng/ml, P < 0.05). Genotyping of CYP2A6 polymorphisms may provide vital information for effective cancer therapy using S-1.

A case of thyrotropin-producing pituitary adenoma, accompanied by an increase in anti-thyrotropin receptor antibody after tumor resection

We describe a rare, but interesting, case of TSH-producing adenoma (TSHoma), accompanied by increases in both anti-TSH receptor antibody (TRAb) and thyroid-stimulating antibody (TSAb) after tumor resection. A 21-yr-old woman was referred to our department for further evaluation of pituitary tumor. In a nearby hospital, she had been diagnosed as having pituitary tumor. Her serum free T4, free T3, and TSH levels were all elevated concomitantly. On the basis of a diagnosis of pituitary adenoma with TSH production, transsphenoidal resection of the pituitary adenoma was performed. Two weeks after the operation, the blood concentrations of TSH were undetectable, whereas both TRAb and TSAb levels were elevated. TSAb levels gradually increased further from 2 weeks to 3 months after the operation, accompanied by an increase in TSH and free T4 levels. TSH is an important hormone in maintaining physiology and regulating immunomodulators in thyrocytes, as it can influence a variety of immune-regulating cytokine-like activities and inhibit expressions of Fas antigen, intracellular adhesion molecule-1, and class II trans-activator. Changes in TSH would modulate the immune circumstances in the thyroid, and then induce TRAb and TSAb. Autoimmune parameters with thyroid function should be observed carefully when managing patients with TSHoma.

Association of novel promoter single nucleotide polymorphisms in vasopressin V1a receptor gene with essential hypertension in nonobese Japanese

We studied the association between four novel single nucleotide polymorphisms (SNPs) in the promoter region of V1aR gene and essential hypertension in 620 Japanese subjects (365 hypertensives and 255 healthy). A significant association was found between one of the genotypes and alleles at SNP -6951 and hypertension in a subsample of nonobese individuals. This association demonstrated an independent risk for nonobese hypertension.

Structural impact of hydrodynamic injection on mouse liver

The impact of hydrodynamic injection on liver structure was evaluated in mice using various microscopic techniques. Upon hydrodynamic injection of approximately 9% of body weight by volume, the liver rapidly expanded, reaching maximal size at the end of the injection and returned to its original size in 30 min. Histological analysis revealed a swollen appearance in the peri-central region of the liver where delivery of genes and fluorescence-labeled markers was observed. Scanning and transmission electron microscopy showed enlargement and rupture of endothelium that in about 24-48 h regains its morphology and normal function as a barrier against infection by adenovirus viral particles. At the cellular level in hydrodynamically treated animals, four types of hepatocytes were seen: cells with normal appearance; cells with enriched vesicles in the cytoplasm; cells with lightly stained cytosol; and cells with significant dilution of the cytoplasm. In addition, red blood cells and platelets were observed in the space of Disse and even inside hepatocytes. Vesicle formation is triggered by hydrodynamic injection and resembles the process of macropinocytosis. These results, whereas confirming the physical nature of hydrodynamic delivery, are important for a better understanding of this efficient method for intrahepatic gene and small interfering RNA delivery.

Comparison between human-telomerase reverse transcriptase mRNA and alpha-fetoprotein mRNA as a predictive value for recurrence of hepatocellular carcinoma in living donor liver transplantation

OBJECTIVE

In this study we compared the potential roles of preoperative human-telomerase reverse transcriptase (h-TERT) mRNA versus alpha-fetoprotein (AFP) mRNA expression in the peripheral blood as a tool to predict prognosis and tumor recurrence after living donor liver transplantation (LDLT) in hepatocellular carcinoma (HCC) patients.

PATIENTS AND METHODS

We examined 14 patients with unresectable HCC who underwent LDLT. Six patients displayed stage IVA HCC that deviated from the Milan criteria, while the rest of the patients fell within the limitations of the Milan criteria. We analyzed the relationship between preoperative h-TERT mRNA or AFP mRNA expression in the peripheral blood and survival without recurrence.

RESULTS

There was no significant difference between the survival curves without recurrence of those patients who did versus did not meet the Milan criteria. There was also no significant difference between the survival curves without recurrence among patients with positive versus negative AFP mRNA expression. However, there was a significant difference (P = .005) between the survival curves without recurrence of those patients with positive preoperative h-TERT mRNA expression versus those who either had an initially negative preoperative h-TERT mRNA or who converted from positive to negative after neoadjuvant immunochemotherapy.

CONCLUSIONS

h-TERT mRNA seemed to prove more valuable than AFP mRNA not only to assess preoperative treatment modalities and postoperative patient surveillance, but also to evaluate prospective LDLT patients with HCC. Moreover, use of h-TERT mRNA could potentially expand the indications for transplantation to patients outside the Milan criteria.

Gene analysis of the calcium channel 1 subunit and clinical studies for two patients with hypokalemic periodic paralysis

Hypokalemic periodic paralysis (HypoPP) is a skeletal muscle disorder in which episodic attacks of muscle weakness occur; they are associated with decreased serum potassium (K+) levels. Recent molecular approaches have clarified that the condition is caused by mutations in the skeletal muscle voltage-gated calcium channel 1 subunit (CACNA1S). We describe two unrelated patients with HypoPP, followed by their relevant clinical studies and gene analysis. Clinical studies included an oral glucose tolerance test (OGTT), food-loading and insulin tolerance tests (ITT). For Case 1, serum K+ levels were extremely decreased following insulin tolerance testing compared with levels for controls. These results support the hypothesis that no efflux of K+ ion occurs in patients because of low activity of adenosine triphosphate (ATP)-sensitive K+ channel (KATP) channels. Mutational analysis of the CACNA1S gene showed a duplicate insertion of 14 base pairs (bp) from 52 to 65 in intron 26, present in the heterozygous state in both patients. No other mutations were detected in the CACNA1S gene, the muscle sodium channel gene (SCN4A) or the voltage-gated K+ channel gene (KCN3) of either patient. Further analysis showed that this duplicate insertion of 14 bp in intron 26 of the CACNA1S gene was found in 23.7% of healthy subjects. K+ dynamics studies are useful for confirming this syndrome, while further gene analysis for various ion channels using amplification and direct sequencing are required to evaluate the molecular basis of the disorder in the individual patient.