Low BMI at age 20 years predicts gestational diabetes independent of BMI in early pregnancy in Japan: Tanaka Women's Clinic Study.

AIMS: Maternal obesity and weight gain since early adulthood are known predictors of gestational diabetes in Western countries. However, their impact has not been evaluated well in Asia, where mean BMI levels are generally lower than in Western countries. We therefore examined the associations of BMI at age 20 years and BMI change since age 20 years with the risk of gestational diabetes in Japanese pregnant women. METHODS: Six hundred and twenty-four consecutive pregnant women without recognized diabetes before pregnancy, whose initial obstetric clinic visit was before 13 weeks' gestation, were prospectively observed. Weight at age 20 years was self-reported. Baseline height and weight measurements were obtained at the initial obstetric visit. Multivariate logistic regression analysis estimated the risk of incident gestational diabetes for BMI change since 20 years and BMI at age 20 years. RESULTS: Twenty-eight women developed incident gestational diabetes. By multivariate logistic regression analysis that adjusted for maternal age, parity and baseline BMI, we observed a statistically significant inverse association between BMI at age 20 years and incidence of gestational diabetes (odds ratio 0.68, 95% CI 0.51-0.92). Similarly, when we assessed the association of BMI change since age 20 years, adjusted for maternal age and parity, BMI change was associated with an increased risk of gestational diabetes (odds ratio 1.26, 95% CI 1.03-1.53). When we focused on the threshold of risk of gestational diabetes, women with BMI at 20 years of less than 18 kg/m(2) had a 6.30-fold (2.26-17.59) greater risk than women with both BMI at age 20 years of 18 kg/m(2) or more and BMI change since age 20 years of less than 1.85. CONCLUSIONS: Both low BMI at age 20 years and BMI change since age 20 years were significantly associated with increased risk of incident gestational diabetes.

HbA(1c) variability and the development of microalbuminuria in type 2 diabetes: Tsukuba Kawai Diabetes Registry 2.

AIMS/HYPOTHESIS: The aim of this study was to examine the association between HbA(1c) variability and the development of microalbuminuria as defined by an albumin/creatinine ratio ≥ 3.4 mg/mmol (≥ 30 mg/g) in at least two of three consecutive urine samples in Japanese patients with type 2 diabetes. METHODS: HbA(1c) level was measured in 812 serially registered normoalbuminuric adults aged 21-79 years with type 2 diabetes. After registration, a 1-year period to establish baseline values for mean HbA(1c) and HbA(1c) variability (measured as the intrapersonal SD of serially collected HbA(1c)) was decided upon. The association between HbA(1c) variability and the development of microalbuminuria was determined by Cox regression analysis after adjustment for other risk factors for microalbuminuria. RESULTS: Microalbuminuria occurred in 193 patients during the observation period of (mean ± SD) 4.3 ± 2.7 years. Even after adjustment for mean HbA(1c), HbA(1c) variability was a significant predictor of microalbuminuria independently of the mean HbA(1c); the HR for every 1% (95% CI) increase in mean HbA(1c) was 1.22 (1.06, 1.40) (p = 0.005), and that for HbA(1c) variability was 1.35 (1.05, 1.72) (p = 0.019). The effects of these two variables were quite similar when 1 SD was used; the HR for every 1 SD increase (95% CI) in HbA(1c) was 1.23 (1.07, 1.43) (p = 0.005), and that for HbA(1c) variability was 1.20 (1.03, 1.39) (p = 0.019). CONCLUSIONS/INTERPRETATION: HbA(1c) variability affects the development of microalbuminuria independently of mean HbA(1c) in type 2 diabetes. Further studies should be performed to evaluate the influence of HbA(1c) variability on other complications and in individuals of other ethnicities with type 2 diabetes.

Exacerbation of diabetic nephropathy by hyperlipidaemia is mediated by Toll-like receptor 4 in mice.

AIMS/HYPOTHESIS: Hyperlipidaemia is an independent risk factor for the progression of diabetic nephropathy, but its molecular mechanism remains elusive. We investigated in mice how diabetes and hyperlipidaemia cause renal lesions separately and in combination, and the involvement of Toll-like receptor 4 (TLR4) in the process. METHODS: Diabetes was induced in wild-type (WT) and Tlr4 knockout (KO) mice by intraperitoneal injection of streptozotocin (STZ). At 2 weeks after STZ injection, normal diet was substituted with a high-fat diet (HFD). Functional and histological analyses were carried out 6 weeks later. RESULTS: Compared with treatment with STZ or HFD alone, treatment of WT mice with both STZ and HFD markedly aggravated nephropathy, as indicated by an increase in albuminuria, mesangial expansion, infiltration of macrophages and upregulation of pro-inflammatory and extracellular-matrix-associated gene expression in glomeruli. In Tlr4 KO mice, the addition of an HFD to STZ had almost no effects on the variables measured. Production of protein S100 calcium binding protein A8 (calgranulin A; S100A8), a potent ligand for TLR4, was observed in abundance in macrophages infiltrating STZ-HFD WT glomeruli and in glomeruli of diabetic nephropathy patients. High-glucose and fatty acid treatment synergistically upregulated S100a8 gene expression in macrophages from WT mice, but not from KO mice. As putative downstream targets of TLR4, phosphorylation of interferon regulatory factor 3 (IRF3) was enhanced in kidneys of WT mice co-treated with STZ and HFD. CONCLUSIONS/INTERPRETATION: Activation of S100A8/TLR4 signalling was elucidated in an animal model of diabetic glomerular injury accompanied with hyperlipidaemia, which may provide novel therapeutic targets in progressive diabetic nephropathy.

Twin-electron biprism.

In order to obtain a large deflection angle without increasing the applied voltage to an electron biprism, we have developed a 'twin-electron biprism' (TBP), which is composed of two filament electrodes and a pair of ground plates. The observed interference-fringe spacing revealed that the deflection angle created by a TBP was about twice larger than that by a 'conventional electron biprism'. Also, we have suggested, in a double-electron biprism interferometry, the optimal disposition of a TBP for reducing the intensity of Fresnel fringes recorded in an electron hologram.

Factors associated with inappropriate weight loss attempts by early adolescent girls in Japan.

Attempting to lose weight by normal or underweight adolescent girls is a serious issue in many countries. It has been reported that the mode of attempted weight loss does not differ between normal weight and overweight girls. These inappropriate weight loss attempts (IWLA) by normal or underweight adolescent girls is associated with various health issues, but factors associated with IWLA have only been marginally elucidated. In this study, we applied a single multivariate regression analysis to clarify independent factors for IWLA. Study subjects were 134 pairs of early adolescent girls (aged 12-15) and their mothers. In addition to IWLA, many factors including height, weight, body image, perceived weight status, depressive symptoms, media influence and self-esteem were surveyed in both mothers and daughters and subjected to multivariate analysis. Approximately half of girls surveyed had IWLA, even though all were of normal weight and 62.9% knew that they were of normal weight. IWLA were independently associated with depressive symptoms (OR (95% CI); 2.80 (1.21-6.50), p=0.016) independent of actual or perceived weight status. Factors significantly associated with IWLA by the girls were percentage deviation of weight from standard weight (%DW) and media influence on the girls themselves, and media influence on and self-esteem of their mothers. IWLA, which were frequently observed among early adolescent girls even among those of normal weight, were closely related to depressive status. IWLA were significantly associated with not only factors related to the girls (1.09 (1.04-1.14), p=0.001), but also with maternal psychological factors (1.06 (1.00-1.13), p=0.035) conveyed by the media. Future prospective or interventional studies are required to clarify whether these factors could be targeted in an effort to prevent IWLA.

Basic evaluation of a novel 4D target and human body phantom.

Stereotactic body radiation therapy (SBRT) is usually verified with a dynamic phantom or solid phantom, but there is a demand for phantoms that can accurately simulate tumor dynamics within an individual that would allow customized validation in every patient. We developed a new 4D dynamic target phantom (multi-cell 4D phantom) that allows simulation of tumor movement in patients. The basic quality and dynamic reproducibility of this new phantom was verified in this investigation. The newly developed multi-cell 4D phantom comprises four main components: soft tissue, bones, lungs, and tumor (target). The phantom structure was based on computed tomography (CT) data of a male. In this study, we investigated the basic performance of a multi-cell 4D phantom. All the CT numbers of the phantom were very close to those of human data. The geometric maximum amplitudes were 4.57 mm in the lateral direction, 4.59 mm in the ventrodorsal direction, and 3.68 mm in the cranio-caudal direction. Geometric errors were 0.84, 0.58, and 0.40 mm, respectively. Movements of the abdominal surface were stable for 60 s. Repeated measurements show no actual differences in target movements between multiple measurements and indicated high reproducibility (r > 0.97). End-to-end tests using Gafchromic film revealed a gamma pass rate of 98% or above (2 mm/3%). Although our phantom performed limited reproducibility in the movement of the patient tumor at present, a satisfactory level of precision was confirmed in general. This is a very promising device for use in the verification of radiation therapy for moving targets.

Overexpression of connective tissue growth factor in podocytes worsens diabetic nephropathy in mice.

Connective tissue growth factor (CTGF) is a potent inducer of extracellular matrix accumulation. In diabetic nephropathy, CTGF expression is markedly upregulated both in podocytes and mesangial cells, and this may play an important role in its pathogenesis. We established podocyte-specific CTGF-transgenic mice, which were indistinguishable at baseline from their wild-type littermates. Twelve weeks after streptozotocin-induced diabetes, these transgenic mice showed a more severe proteinuria, mesangial expansion, and a decrease in matrix metalloproteinase-2 activity compared to diabetic wild-type mice. Furthermore, diabetic transgenic mice exhibited less podocin expression and a decreased number of diffusely vacuolated podocytes compared to diabetic wild-type mice. Importantly, induction of diabetes in CTGF-transgenic mice resulted in a further elevation of endogenous CTGF mRNA expression and protein in the glomerular mesangium. Our findings suggest that overexpression of CTGF in podocytes is sufficient to exacerbate proteinuria and mesangial expansion through a functional impairment and loss of podocytes.

Adrenomedullin inhibits connective tissue growth factor expression, extracellular signal-regulated kinase activation and renal fibrosis.

Systemic administration of the potent vasodilating peptide adrenomedullin reduces cardiac and renal fibrosis in hypertensive animals. Here, we investigated the effects of kidney-specific adrenomedullin gene delivery in normotensive rats after unilateral ureteral obstruction, an established model of renal tubulointerstitial fibrosis. Overexpression of exogenous adrenomedullin in the renal interstitium following ureteral obstruction significantly prevented fibrosis and proliferation of tubular and interstitial cells. In this model, there is upregulation of connective tissue growth factor (CTGF) mRNA expression and extracellular signal-regulated kinase (ERK) phosphorylation, and adrenomedullin overexpression suppressed both of these activities without altering the blood pressure. In NRK-49F renal fibroblasts, adrenomedullin reduced transforming growth factor-beta-induced CTGF and fibronectin mRNA upregulation through the cyclic AMP/protein kinase A signaling pathway, and suppressed ERK phosphorylation and cell proliferation. In the kidneys with an obstructed ureter, adrenomedullin receptor gene expression was upregulated along with cyclic AMP production in kidney slices. The latter effect was partially blocked by a neutralizing antibody to adrenomedullin, indicating that an endogenous peptide-receptor system was activated. Our results show that overexpression of exogenous adrenomedullin in the ureteral-obstructed kidney prevents tubulointerstitial fibrosis and cell proliferation through the cyclic AMP-mediated decrease of CTGF induction and ERK phosphorylation.

New insights on the mechanism(s) of the dominant negative effect of mutant thyroid hormone receptor in generalized resistance to thyroid hormone.

Generalized resistance to thyroid hormone (GRTH) is a syndrome of hyposensitivity to triiodothyronine (T3) that displays autosomal dominant inheritance. The genetic defect commonly lies in the ligand-binding domain of one of the TR beta alleles. Since there are two major thyroid hormone receptor (TR) isoforms, TR alpha and TR beta, it is not known how the mutant receptor mediates a dominant negative effect. Previously, we showed that T3 caused dissociation of TR homodimers and TR alpha/TR beta dimers from several thyroid hormone response elements (TREs). Hence, we used the electrophoretic mobility shift assay to compare the effect of T3 on the DNA binding of mutant TR beta-1 (Mf-1) from a kindred with GRTH with normal TR beta. Mf-1 bound better as a homodimer than TR beta, but dissociated from DNA only at high T3 concentrations. Both receptors heterodimerized with nuclear auxiliary proteins. They also dimerized with TR alpha and with each other. Surprisingly, T3 disrupted the DNA binding of the Mf-1/TR isoform dimers. Thus, mechanisms for the dominant negative effect by mutant TRs likely involve either increased binding to TREs by mutant homodimers that cannot bind T3 (hence cannot dissociate from DNA) and/or the formation of inactive mutant TR/nuclear protein heterodimers.

Synthesis of atrial natriuretic polypeptide in human failing hearts. Evidence for altered processing of atrial natriuretic polypeptide precursor and augmented synthesis of beta-human ANP.

To elucidate the synthesis of atrial natriuretic polypeptide (ANP) in the failing heart, 20 human right auricles obtained at cardiovascular surgery were studied. The concentration of alpha-human ANP-like immunoreactivity (alpha-hANP-LI) in human right auricles ranged from 13.8 to 593.5 micrograms/g, and the tissue alpha-hANP-LI concentration in severe congestive heart failure (CHF) (New York Heart Association [NYHA] functional class III and class IV) (235.4 +/- 57.2 micrograms/g) was much higher than that in mild CHF (NYHA class I and class II) (52.5 +/- 15.6 micrograms/g). Atrial alpha-hANP-LI levels were significantly correlated with plasma concentrations of alpha-hANP-LI in these patients (r = 0.84, P less than 0.01). High performance gel permeation chromatography and reverse phase high performance liquid chromatography coupled with radioimmunoassay for ANP revealed that the alpha-hANP-LI in the human auricle consisted of three major components of ANP, gamma-human ANP (gamma-hANP), beta-human ANP (beta-hANP) and alpha-human ANP (alpha-hANP). Comparing percentages of gamma-hANP, beta-hANP, and alpha-hANP in alpha-hANP-LI in severe CHF with those in mild CHF, the predominant component of alpha-hANP-LI was gamma-hANP in mild CHF, whereas beta-hANP and/or alpha-hANP were prevailing in severe CHF and, especially, beta-hANP was markedly increased in human failing hearts. These results demonstrate that the total ANP concentration in the atrium of the human heart is increased in severe CHF and that the increase of ANP in the human failing heart is mainly due to the increase of small molecular weight forms of ANP, beta-hANP, and alpha-hANP, especially beta-hANP, and indicate that the processing of ANP precursor, or gamma-hANP, in the human failing heart differs from that in the normal heart, suggesting that the failing heart augments synthesis and secretion of ANP as one of its own compensatory responses.

Chronic blockade of endogenous atrial natriuretic polypeptide (ANP) by monoclonal antibody against ANP accelerates the development of hypertension in spontaneously hypertensive and deoxycorticosterone acetate-salt-hypertensive rats.

To explain the pathophysiological significance of endogenous atrial natriuretic polypeptide (ANP) in the development of hypertension, we examined the effect of chronic, repetitive administrations of MAb raised against alpha-rat ANP in two rat models of hypertension, spontaneously hypertensive rats of the stroke prone substrain (SHR-SP), and deoxycorticosterone acetate (DOCA)-salt rats. Weekly intravenous administrations of MAb with high affinity for alpha-rat ANP, named KY-ANP-II (MAb[KY-ANP-II]), started at the age of 6 wk, significantly augmented the rise in blood pressure of SHR-SP, compared with control SHR-SP treated with another MAb with quite low affinity for alpha-rat ANP, named KY-ANP-I (MAb[KY-ANP-I]), throughout the observation period. The administrations of MAb[KY-ANP-II] had no significant effect on blood pressure of age-matched normotensive Wistar Kyoto rats, compared with those receiving MAb[KY-ANP-I]. Weekly administrations of MAb[KY-ANP-II] also significantly aggravated hypertension in DOCA-salt rats. Blood pressure of DOCA-salt rats treated with MAb[KY-ANP-II] was significantly higher than that of DOCA-salt rats treated with MAb[KY-ANP-I] throughout 8 wk of DOCA and 1% saline administration. The administration of MAb[KY-ANP-II] also significantly attenuated exaggerated diuresis and natriuresis in DOCA-salt rats compared with those treated with MAb[KY-ANP-I]. Elevated plasma cGMP levels of both SHR-SP and DOCA-salt rats were significantly reduced by the administration of MAb[KY-ANP-II]. These results suggest the compensatory role of augmented secretion of ANP in these hypertensive rats and support the concept that augmented secretion of ANP could represent an antihypertensive deterrent mechanism.

Augmented expression of atrial natriuretic polypeptide gene in ventricle of human failing heart.

To elucidate the expression of the atrial natriuretic polypeptide (ANP) gene in the ventricle of the human failing heart, we have measured ANP and ANP messenger RNA (ANPmRNA) levels in left ventricular aneurysm obtained at operation, biopsy specimens of left ventricles from dilated cardiomyopathy (DCM) and autopsy samples of old myocardial infarction (OMI) and DCM hearts, and compared the levels with those in the normal ventricle. The ANP level (mean +/- SE) was 17.5 +/- 6.9 ng/g in the normal ventricle, and increased to 660.3 +/- 122.2 ng/g in the left ventricular aneurysm tissues and to 3,138.6 +/- 1,642.1 ng/g in the biopsy specimens of the DCM ventricle. These levels were approximately 40 and 200 times higher than in the normal ventricle. The increase of ANP levels was observed in both infarcted and noninfarcted regions of the OMI heart, and in the entire ventricle of the DCM heart. A significant positive correlation was found between the ANP level in aneurysm tissues and pulmonary capillary wedge pressure (r = 0.85). The ANPmRNA level in the left ventricular aneurysm showed about a 10-fold increase compared with that in the normal heart and reached 23% of that in the atrium of the same heart. A similar increase in the ANPmRNA level was observed in the entire ventricle of DCM. These data clearly indicate that the expression of the ANP gene in the ventricle is augmented in the failing heart in accordance with the severity of heart failure. In the atrium of the failing heart, ANP and ANPmRNA levels were only two times higher than those in the normal atrium. Thus, the augmentation in the expression of the ANP gene was more prominent in the ventricle than in the atrium. Taking tissue weight into account, the total content of ANPmRNA in the ventricle of the failing heart is much the same as that in the normal atrium. The ratio of the ANP level to the ANPmRNA level in the ventricle is much smaller than that in the atrium. These results suggest more rapid secretion of ANP after synthesis in the ventricle. These findings demonstrate that the expression of the ANP gene is augmented in the human ventricle of the failing heart and suggest that the ventricle becomes a substantial source of circulating ANP in congestive heart failure.

Intravenous dexmedetomidine for cesarean delivery and its concentration in colostrum.

BACKGROUND: Dexmedetomidine is a sedative agent with high α2-adrenoreceptor selectivity. We investigated intravenous dexmedetomidine administration during scheduled cesarean delivery under neuraxial anesthesia; and its concentration in the colostrum. METHODS: Twenty-seven participants having elective cesarean delivery under combined spinal-epidural anesthesia were enrolled. After delivery and cord clamping, 6µg/kg/h of intravenous dexmedetomidine was administered for 10minutes, followed by a dose of 0.7µg/kg/h until peritoneal closure. Sedation, vital signs and side effects were recorded. Blood and colostrum samples were collected from each participant at 6, 12, and 24h after dexmedetomidine administration. Samples were analysed using liquid chromatography tandem-mass spectroscopy. RESULTS: Colostrum samples were collected from 10 patients. The median [95% CI] plasma dexmedetomidine concentration was 333 [303-534] pg/ml at 0h and 19.7 [13.5-25.8] pg/ml at 6h. The colostrum concentration was 12.3 [8.1-20.1] pg/ml at 6h. The dexmedetomidine completely disappeared from both within 24h. The calculated milk-to-plasma ratio at 6h was 0.76 [0.57-0.86]. The relative infant dose was 0.034% [0.020-0.062%]. At dexmedetomidine discontinuation, the Richmond Agitation-Sedation Scale score was -2 (range,-4 to -1). During surgery, no patients complained of nausea, peritoneal irritation or afterbirth pain. CONCLUSIONS: The dexmedetomidine milk-to-plasma ratio did not exceed 1 in any participant, and the relative infant dose was very low. Maternal sedation using dexmedetomidine is unlikely to be harmful for the infant.

Peroxisome proliferator-activated receptor gamma in human breast carcinoma: a modulator of estrogenic actions.

It has been reported that agonists of peroxisome proliferator-activated receptor gamma (PPARgamma) inhibit proliferation of breast carcinoma cells, but the biological significance of PPARgamma remains undetermined in human breast carcinomas. Therefore, we immunolocalized PPARgamma in 238 human breast carcinoma tissues. PPARgamma immunoreactivity was detected in 42% of carcinomas, and was significantly associated with the status of estrogen receptor (ER) alpha, ERbeta, progesterone receptor, retinoic X receptors, p21 or p27, and negatively correlated with histological grade or cyclooxygenase-2 status. PPARgamma immunoreactivity was significantly associated with an improved clinical outcome of breast carcinoma patients by univariate analysis, and multivariate analysis demonstrated that PPARgamma immunoreactivity was an independent prognostic factor for overall survival in ERalpha-positive patients. We then examined possible mechanisms of modulation by PPARgamma on estrogenic actions in MCF-7 breast carcinoma cells. A PPARgamma activator, 15-deoxy-Delta(12,14)- prostaglandin J(2) (15d-PGJ(2)), significantly inhibited estrogen-responsive element-dependent transactivation by estradiol in MCF-7 cells, which was blocked by addition of a PPARgamma antagonist GW9662. Subsequent study, employing a custom-made microarray focused on estrogen-responsive genes, revealed that mRNA expression was significantly regulated by estradiol in 49 genes, but this significance vanished on addition of 15d-PGJ(2) in 16 out of 49 (33%) genes. These findings were confirmed by real-time PCR in 11 genes. 15d-PGJ(2) significantly inhibited estrogen-mediated proliferation of MCF-7 cells, and caused accumulation of p21 and p27 protein. These results suggest that PPARgamma is mainly expressed in well-differentiated and ER-positive breast carcinomas, and modulates estrogenic actions.

The complete nucleotide sequence of the mitochondrial genome of sugar beet (Beta vulgaris L.) reveals a novel gene for tRNA(Cys)(GCA).

We determined the complete nucleotide sequence of the mitochondrial genome of an angiosperm, sugar beet (Beta vulgaris cv TK81-O). The 368 799 bp genome contains 29 protein, five rRNA and 25 tRNA genes, most of which are also shared by the mitochondrial genome of Arabidopsis thaliana, the only other completely sequenced angiosperm mitochondrial genome. However, four genes identified here (namely rps13, trnF-GAA, ccb577 and trnC2-GCA) are missing in Arabidopsis mitochondria. In addition, four genes found in Arabidopsis (ccb228, rpl2, rpl16 and trnY2-GUA) are entirely absent in sugar beet or present only in severely truncated form. Introns, duplicated sequences, additional reading frames and inserted foreign sequences (chloroplast, nuclear and plasmid DNA sequences) contribute significantly to the overall size of the sugar beet mitochondrial genome. Nevertheless, 55.6% of the genome has no obvious features of information. We identified a novel tRNA(Cys) gene (trnC2-GCA) which shows no sequence homology with any tRNA(Cys) genes reported so far in higher plants. Intriguingly, this tRNA gene is actually transcribed into a mature tRNA, whereas the native tRNA(Cys) gene (trnC1-GCA) is most likely a pseudogene.

Primary care in the treatment of functional gastrointestinal symptoms in Japan: prescription preferences and impression of results.

BACKGROUND: Functional gastrointestinal (GI) disorders are common in primary care. However, proper pharmacological approaches have not yet been established. The reason for a lack of proper approaches may be attributable to the lack in clarity of their pathogenesis and pathophysiology. Meta-analysis of pharmacological approaches to functional GI disorders failed to identify the solid cluster of patients' symptoms. AIM: The aim of this study is to assess the perspective of primary care doctors concerning prescriptions for functional GI symptoms, evaluate the efficacy of the drugs prescribed, and the need for medication for these symptoms. METHOD: Questionnaires were sent to primary care doctors, and a total of 149 responses were obtained. Efficacy of each medication was evaluated by the number of doctors favouring the category, and the respective impressions of prescriptions given. RESULTS: Symptoms of heartburn were well controlled by anti-secretory drugs (H2RAs and PPIs), while appetite loss and abdominal gurgling were not controlled by any medications. CONCLUSIONS: This survey reveals differences in need for various prescription drugs in functional GI symptoms.

Molecular cloning and expression of a novel klotho-related protein.

Klotho protein is a novel beta-glucosidase-like protein produced predominantly in the kidney. The klotho mouse, which genetically lacks klotho gene expression, manifests various systemic phenotypes resembling aging. In the present study we succeeded in isolating a novel human protein structurally related to klotho protein. The protein possesses one beta-glucosidase-like domain and is 42% identical with klotho protein at the amino acid level. Unlike klotho protein, it possesses neither a signal sequence nor a transmembrane domain, suggesting that it is a cytosolic protein, and thus was termed cytosolic beta-glucosidase-like protein-1 (cBGL1). By Northern blot analysis cBGL1 mRNA was expressed most abundantly in the liver, followed by the small intestine, colon, spleen, and kidney. When klotho and cBGL1 gene expression was examined in renal cell carcinoma tissues, both klotho and cBGL1 mRNA levels in tumors were lower than those in nontumor regions, suggesting that renal epithelial cells may lose klotho and cBGL1 gene expression during the course of malignant transformation. In conclusion, we describe the primary structure and gene expression of a novel protein related to klotho protein.

9-cis retinoic acid regulation of rat growth hormone gene expression: potential roles of multiple nuclear hormone receptors.

Rat GH (rGH) gene expression is increased by both thyroid hormone (T3) and all-trans retinoic acid (RA) via a composite hormone response element (HRE) containing three putative half-sites (rGH-HRE). However, it is not known whether 9-cis RA (9cRA) also can regulate rGH gene expression. In this study, we performed a Northern blot analysis that demonstrated that 9cRA, as well as T3 and RA, increased rGH messenger RNA expression in rat pituitary GH3 cells. Transient transfection studies in GH3 cells, using reporter plasmids containing the rGH-HRE and mutated half-sites, revealed that 9cRA-stimulation of rGH transcription was mediated by the rGH-HRE and that all three half-sites are necessary. Additionally, we performed cotransfection studies to elucidate the particular receptor complexes involved in 9cRA regulation of rGH gene expression using CV-1 cells, which contain little or no endogenous RA receptors, and thyroid hormone receptors. Interestingly, in the presence of either retinoid X receptor alone, RA receptors alone, or both receptors, 9cRA caused similar induction of transcriptional activity. However, cotransfection of thyroid hormone receptors with these receptors repressed basal and blocked 9cRA-induced transcriptional activity in the absence of T3. Our data suggest that 9cRA-stimulation of rGH transcription is likely mediated by 9cRA-bound retinoid X receptor- and/or RA receptor-containing complexes but not by thyroid hormone receptor-containing complexes. Our studies provide evidence that several different members of the nuclear hormone receptor family can interact on this composite DNA element, with transcription stimulated or blocked depending on the presence or absence of cognate ligands.