Novel mutations in the gene encoding acid α-1,4-glucosidase in a patient with late-onset glycogen storage disease type II (Pompe disease) with impaired intelligence.

A 17-year-old Japanese man was referred to our hospital because of highly elevated serum levels of creatine kinase (CK) and transaminases. On admission, the proximal muscles of the lower extremities were found to be predominantly affected, and a score of 3/5 was obtained on Medical Research Council (MRC) scale. Muscular atrophy was evident and Gowers' sign was positive. His functional vital capacity (FVC) was markedly reduced. The results of the third edition of the Wechsler Adult Intelligence Scale (WAIS-III) indicated impairment of the patient's intelligence. Muscle biopsy showed scattered intracytoplasmic vacuoles with basophilic amorphous materials inside which were strongly stained by both periodic acid Schiff (PAS) and acid phosphatase. Biochemical analysis of the muscle tissue confirmed the diagnosis of GSDII because the glucosidase activity was 1.0 nmol/4 MU/mg/30 min (control range, 7.3 ± 2.2). Genetic analysis revealed a novel compound heterozygous missense mutation in GAA--c.1814 G >A (p.Gly605Asp) and c.1846 G >A (p.Asp616Asn) both in exon 13.

Hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome with pituitary apoplexy.

After hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome was diagnosed in a 35-year-old woman at 39 weeks' gestation, magnetic resonance imaging and hormone examination revealed pituitary apoplexy with panhypopituitarism and diabetes insipidus. Evaluation of pituitary function should be considered in patients with HELLP syndrome.

Exendin-4 regulates GLUT2 expression via the CaMKK/CaMKIV pathway in a pancreatic ß-cell line.

The GLUT2 glucose transporter plays an important role in glucose-induced insulin secretion in pancreatic ß-cells by catalyzing the uptake of glucose into the cell. In this study, we investigated whether exendin-4, a long-acting agonist of glucagon-like peptide-1, mediates stimulatory effects on GLUT2 gene expression through the Ca²+/calmodulin (CaM)-dependent protein kinase IV (CaMKIV) cascade. GLUT2 expression was examined by real-time polymerase chain reaction, Western blot analysis, and a reporter gene assay in rat insulin-secreting INS-1 cells incubated with exendin-4. An increased expression level of GLUT2 protein was noted in response to increasing concentrations of exendin-4, with maximal induction at 10 nmol/L. Real-time polymerase chain reaction analysis similarly revealed a significant increase in the amount of GLUT2 messenger RNA by 10 nmol/L exendin-4. Exendin-4 also stimulated GLUT2 promoter activity in response to increasing exendin-4 concentrations, but failed to do so in the presence of STO-609, a CaMKK inhibitor. We also investigated the effect of the constitutively active form of CaMKK (CaMKKc) on GLUT2 promoter activity. The result is consistent with the observations that CaMKKc/CaMKIV enhanced or up-regulated GLUT2 promoter activity in INS-1 cells. Furthermore, exendin-4 induction of GLUT2 protein expression was significantly suppressed in the cells knocking down the CaMKIV. In summary, activation of the CaMKK/CaMKIV cascade might be required for exendin-4-induced GLUT2 gene transcription, indicating that exendin-4 plays an important role in insulin secretion in pancreatic ß-cells.

Misdiagnosis of two cases of primary aldosteronism owing to failure of computed tomography to detect adrenal microadenoma.

Recent studies have suggested that primary aldosteronism (PA) is a common form of hypertension. However, some cases of PA are overlooked because microadenoma is difficult to detect by imaging. The author report 2 cases in which aldosterone-producing microadenoma was diagnosed by selective adrenal venous sampling (AVS) and furosemide plus upright test. These adenomas were resected by laparoscopic adrenalectomy. Both cases presented with hypertension and hypokalemia. Experimental data, including those obtained from furosemide plus upright test, suggested PA. In both cases, computed tomography imaging revealed a normal adrenal gland without any tumor. However, selective AVS indicated unilateral hypersecretion of aldosterone. Laparoscopic adrenalectomy was performed, and clinical symptoms of the patients improved. The histopathologic findings revealed aldosterone-producing microadenomas with diameters of 6 and 3 mm, respectively, in cases 1 and 2. In conclusion, AVS should be performed to confirm the diagnosis of PA when computed tomography imaging does not provide definite results.

Prolactin regulatory element-binding protein involved in cAMP-mediated suppression of adiponectin gene.

Adiponectin (ApN) has several protective effects against diabetes and atherosclerosis. However, the detailed mechanisms of the regulation of the ApN gene have not yet been clarified. Prolactin regulatory element-binding (PREB) protein has been identified as a factor that regulates insulin gene expression in the pancreas. PREB is located not only in the pancreas but also in adipose tissue; however, its role in adipose tissue is not known. To analyse the effects of PREB on ApN gene transcription, we employed a reporter gene assay and electrophoretic mobility shift assay (EMSA). In the cells expressing or knocking down the PREB, ApN expression was determined. PREB was located mainly in the nuclei of adipose tissue and its cell line, 3T3-L1 cells. The nuclear extract contained ApN promoter-binding activity that was super-shifted by PREB antiserum in EMSA studies. In the 3T3-L1 cells, the co-expression of PREB and the ApN promoter inhibited the activity of the latter. The addition of cAMP to the cells increased PREB expression in a dose-dependent manner. A deletional analysis of the ApN promoter showed that the PREB-responsive cis-element in the ApN promoter mediated the transcriptional effect of PREB, whereas a mutant of this motif in the ApN promoter abrogated the effect of PREB, as well as that of cAMP. Furthermore, cells expressing or knocking down PREB exhibited decreased and increased ApN expression, respectively. These results demonstrate that PREB may contribute to the regulation of ApN gene transcription, in response to cAMP activation in adipocytes.

The transcriptional factor PREB mediates MCP-1 transcription induced by cytokines in human vascular endothelial cells.

OBJECTIVE: The prolactin regulatory element binding (PREB) protein is a transcriptional factor that regulates prolactin promoter activity in rat anterior pituitary. It is expressed not only in the anterior pituitary but also in the cardiovascular system, including in human umbilical vascular endothelial cells (HUVECs). Monocyte chemoattractant protein-1 (MCP-1) is a major chemotactic factor for monocytes and a key factor initiating the inflammatory process of atherogenesis. MCP-1 is expressed in HUVECs in response to several different stimuli, including interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha. METHODS AND RESULTS: MCP-1 expression was regulated by IL-1beta and TNF-alpha and cytokine-induced PREB expression. Conversely, over-expression of PREB using a PREB-expressing adenovirus increased MCP-1 expression in HUVECs. In addition, PREB induced the expression of the luciferase reporter protein under the MCP-1 promoter control. EMSA showed that the transcriptional effect of PREB was mediated by its binding to the PREB-responsive cis-element of the MCP-1 promoter. Finally, we used siRNA to inhibit PREB expression in HUVECs and demonstrated that knockdown of PREB expression attenuated the effects of IL-1beta and TNF-alpha on MCP-1 expression. CONCLUSIONS: In summary, our findings show that PREB can function as a transcriptional regulator of the MCP-1 promoter in response to cytokines.

Co-existence of glucagonoma with recurrent insulinoma in a patient with multiple endocrine neoplasia-type 1 (MEN-1).

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by tumors of the parathyroid glands, the anterior pituitary, and the endocrine pancreas. Our patient was a 58-year-old man who manifested typical features of MEN-1 including primary hyperparathyroidism, lung carcinoid, and lipomas and insulinoma. He was admitted to our hospital because of recurrent hypoglycemia and a growth of pancreatic tumors. The first operation for insulinoma was performed when he was 20 years old. We found a germline mutation of the MEN1 gene (E45G, exon 2) in this patient. According to these examinations and his clinical course, the patient was diagnosed as having a recurrence of insulinoma. He subsequently underwent surgery for the pancreatic tumors. The majority of these tumor cells were immunohistochemically positive for insulin and negative for glucagon. A few nodules showed immunohistochemical staining positivity for glucagon but they were negative for insulin. Although it is uncommon for patients with MEN1 to exhibit insulinoma and glucagonoma, this case suggests the need for careful analysis of pancreatic tumors in patients with MEN1.

PREB regulates transcription of pancreatic glucokinase in response to glucose and cAMP.

Prolactin regulatory element binding (PREB) is a transcription factor that regulates prolactin promoter activity in rat anterior pituitary. The PREB protein is not only expressed in the anterior pituitary but also in the pancreas. We have recently reported that in pancreatic beta-cells, PREB regulates the transcription of the insulin gene in response to glucose stimulation. In the current study, we have examined the role of PREB in regulating glucokinase (GK) in pancreatic beta-cells. To analyse the effects of PREB on GK gene transcription, we employed a reporter gene assay. In the cells expressing or with knocked down PREB, GK expression was determined. GK expression was regulated by glucose and cAMP, and both glucose and cAMP stimulated the expression of PREB in a dose-dependent manner. Conversely, overexpression of PREB using a PREB-expressing adenovirus increased the expression of the GK protein. GK enzymatic activity was also significantly increased in the cells that stably expressed PREB. In addition, PREB induced GK promoter activity. Chromatin immunoprecipitation (ChIP) analyses showed that PREB mediated its transcriptional effect by binding to the PREB-responsive cis-element of the GK promoter. Finally, we used siRNA to inhibit PREB expression in cells and demonstrated that the knockdown of PREB attenuated the effects of glucose and cAMP on GK expression. Our data show that in pancreatic -cells, PREB regulates the transcription of the GK gene in response to glucose and cAMP.

Improvement in renal dysfunction and symptoms after laparoscopic adrenalectomy in a patient with pheochromocytoma complicated by renal dysfunction.

A 70-year-old patient who was undergoing treatment for diabetes mellitus and chronic hepatitis was admitted to our hospital for evaluation of a tumor in the left adrenal gland (50 x 45 mm) and renal failure. On the basis of the patient's increased serum concentrations of catecholamines and other metabolites and the results of positron emission tomography (PET), the patient was diagnosed with a pheochromocytoma; iodinated metaiodobenzylguanidine ([(131)I]MIBG) scintigraphy was insufficient to establish this diagnosis. Subsequently, he underwent surgery for tumor resection. Histological examination suggested the tumor to be a malignant pheochromocytoma. After left adrenalectomy was performed, the elevated catecholamine and metabolite concentrations and the blood pressure were restored to normal, and the patient's symptoms of severe headaches and vertigo reduced. Furthermore, his renal function improved (Cr 2.0-1.2 mg/dl). Our patient exhibited a rare condition of pheochromocytoma complicated by renal failure, which was successfully treated with laparoscopic surgery.

A case of Dunnigan-type familial partial lipodystrophy (FPLD) due to lamin A/C (LMNA) mutations complicated by end-stage renal disease.

Dunnigan-type familial partial lipodystrophy (FPLD) is a rare monogenic adipose tissue disorder in which the affected subjects have increased predisposition to insulin resistance and related metabolic complications, such as glucose intolerance, diabetes, dyslipidemia, and hepatic steatosis. Our patient was a 35-year-old female who had been receiving insulin injection therapy for diabetes mellitus and was transferred to our hospital. She was diagnosed with FPLD on the basis of the following symptoms: increase in subcutaneous fat in the face, neck, and upper trunk; loss of subcutaneous fat in the lower limbs and the gluteal region. We found a heterozygous CGG to CAG transition in codon 482 of exon 8 in the gene encoding lamin A/C (LMNA), which leads to an arginine to glutamine substitution (R482Q). At the time of admission, her serum creatinine level was 8.4 mg/dl, and her blood urea nitrogen (BUN) level was 81 mg/dl. Her serum creatinine level was elevated and hemodialysis was performed twice every week. However, she died of cerebral hemorrhage 9 months after hemodialysis. Although it is uncommon for patients with FPLD to exhibit renal dysfunction and require hemodialysis, this case suggests the need for careful analysis of renal function in a patient with FPLD.

The prolactin regulatory element-binding regulates of the 11beta-hydroxylase gene.

Prolactin regulatory element-binding (PREB) protein is a transcription factor not only in pituitary but also adrenal gland. Steroid 11beta-hydroxylase (CYP11B1), a member of the cytochrome p-450 superfamily, is responsible for the last step of glucocorticoid biosynthesis in the adrenal cortices of many kinds of animals. In the present study, we have examined the role of PREB in regulating CYP11B1. CYP11B1 expression was found to be regulated by cAMP, which stimulated the expression of PREB. In addition, PREB induced the expression of the luciferase reporter protein that was under the control of the CYP11B1 promoter. Electrophoretic mobility shift analysis (EMSA) showed that PREB mediates its transcriptional effect by binding to the PREB-responsive cis-element (PRCE) of the CYP11B1 promoter. The knockdown of PREB expression attenuated the effects of cAMP on CYP11B1 expression. In summary, our data showed that in the adrenal gland, PREB regulates the transcription of the CYP11B1 gene via cAMP.

The transcriptional factor prolactin regulatory element-binding protein mediates the gene transcription of adrenal scavenger receptor class B type I via 3',5'-cyclic adenosine 5'-monophosphate.

Prolactin regulatory element-binding (PREB) protein is a transcription factor that regulates prolactin promoter activity in the rat anterior pituitary. The PREB protein is not only expressed in the anterior pituitary but also in the adrenal gland. However, the role of PREB in the adrenal gland is not clearly understood. Scavenger receptor class B type I (SR-BI) is a receptor for high-density lipoprotein that mediates the cellular uptake of high-density lipoprotein-cholesteryl ester and is a major route for cholesterol delivery to the steroidogenic pathway in the adrenal gland. In the present study, we have examined the role of PREB in regulating SR-BI. SR-BI expression was found to be regulated by cAMP, which stimulated the expression of PREB in a dose-dependent manner. Conversely, overexpression of PREB using a PREB-expressing adenovirus increased the expression of the SR-BI protein in the adrenocortical cell line Y-1. In addition, PREB induced the expression of the luciferase reporter protein that was under the control of the SR-BI promoter. EMSA showed that PREB mediates its transcriptional effect by binding to the PREB-responsive cis-element of the SR-BI promoter. Finally, we used small interfering RNA to inhibit PREB expression in the Y-1 cells and demonstrated that the knockdown of PREB expression attenuated the effects of cAMP on SR-BI expression. In summary, our data showed that in the adrenal gland, PREB regulates the transcription of the SR-BI gene via cAMP.

Esophageal function worsens with long duration of diabetes.

BACKGROUND: The aim of this study was to assess the relationship between the duration of diabetes and esophageal dysfunction. METHODS: We examined 66 patients with type 2 diabetes. Duration of diabetes was determined by asking patients and from their medical records. The patients were divided into three groups according to the duration of their diabetes: group A, 1-4 years, n=26; group B, 5-9 years, n=20; and group C, 10+ years, n=20. Ambulatory esophageal 24-h pH and motility were monitored, and gastroesophageal reflux and esophageal motility disorders were estimated in detail. RESULTS: When the duration of diabetes was long, the percentage of time with pH<4 tended to increase. The amplitude of esophageal peristaltic waves and the frequency of effective peristalsis were reduced when the duration of diabetes was long. A significant correlation was observed between the duration of diabetes and the frequency of effective peristalsis. The number of esophageal peristaltic waves per minute and the percentage of multipeaked peristaltic waves increased significantly in group B, and decreased when the duration of diabetes became longer. CONCLUSIONS: Gastroesophageal reflux and esophageal motility disorders worsened with long duration of diabetes. These esophageal dysfunctions should be considered in patients with long-standing diabetes.

Isolated follicle-stimulating hormone (FSH) deficiency without mutation of the FSHbeta gene and successful treatment with human menopausal gonadotropin.

OBJECTIVE: To describe the case of isolated follicle-stimulating hormone (FSH) deficiency without mutation of the FSHbeta gene. DESIGN: Case report. SETTING: Division of Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan. PATIENT(S): A 22-year-old man referred for infertility, azoospermia, and isolated FSH deficiency. INTERVENTION(S): The patient's FSHbeta gene was sequenced. Pituitary function at baseline and after repeated GnRH administration was evaluated. Testicular biopsy was performed. The patient was treated with human menopausal gonadotropin (hMG). MAIN OUTCOME MEASURE(S): Pathologic examination revealed hypospermatogenesis with isolated FSH deficiency without mutation of the FSHbeta gene. RESULT(S): The FSH levels remained below the normal range despite repeated GnRH stimulation. Hypospermatogenesis was confirmed by testicular biopsy. After 6 months of hMG treatment, spermatogenesis was successfully induced. CONCLUSION(S): We report the case of an infertile male with isolated FSH deficiency without any evidence of mutation in the FSHbeta gene.

D-Psicose inhibits the expression of MCP-1 induced by high-glucose stimulation in HUVECs.

Monocyte chemoattractant protein-1 (MCP-1) is a 76-amino-acid chemokine thought to be the major chemotactic factor for monocytes. MCP-1 is found in macrophage-rich areas of atherosclerotic lesions. Recent report indicates that MCP-1 is induced by glucose-stimulation, raising the important link between diabetes mellitus and atherosclerosis. One of the rare sugars, d-psicose (d-ribo-2-hexulose) is present in small quantities in commercial carbohydrate complexes, however the physiological functions of d-psicose have not been evaluated. In this study, we examined the effects of d-psicose on MCP-1 expression in human umbilical vein endothelial cells (HUVECs). Results showed that MCP-1 mRNA and protein were stimulated following exposure to 22.4 mM glucose. Transcriptional activity of MCP-1 promoter paralleled endogenous expression of the gene and this activity was dependent on the dose of d-glucose. d-Psicose inhibited these effects. Next we used inhibitors of selected signal transduction pathways to show that high-glucose (HG) stimulated MCP-1 promoter activity was sensitive to p38-Mitogen-Activated Protein Kinase (p38-MAPK) pathway inhibitor. As expected, a dominant-negative p38-MAPK abolished the stimulatory effect of HG on the promoter activity. To incubate the cells with HG and d-psicose reduced the activation of p38-MAPK. Together, these results indicate that the d-psicose suppression of HG induced MCP-1 expression is mediated in part by inhibition of the p38-MAPK pathway and raise the possibility that d-psicose may be of therapeutic value in the treatment of diseases such as atherosclerosis.

Insulin-like growth factor-i regulation of hepatic scavenger receptor class BI.

High-density lipoprotein mediates a normal physiological process called reverse cholesterol transport. This process enables the transfer of cholesterol from peripheral tissues to the liver for further metabolism and eventual secretion in the form of bile. The scavenger receptor of the B class (SR-BI), human homolog of SR-BI, and CD36 and LIMPII analogous-1 (CLA-1) are different names for the same receptor that facilitates hepatocellular uptake of cholesterol from high-density lipoprotein. The pivotal role of this receptor in enterohepatic circulation of cholesterol and bile salts underlies our interest to study the regulation of hepatic SR-BI gene in response to the actions of IGF-I. The results of our studies showed that endogenous expression of SR-BI/CLA-1 was suppressed by exposure to GH or IGF-I in cultured HepG2 cells. This observation extended to a whole animal model of rats continuously infused with IGF-I. IGF-I decreased transcriptional activity of the SR-BI promoter. However, the inhibitory effect of IGF-I on SR-BI/CLA-1 promoter activity was abrogated by wortmannin, a specific inhibitor of phosphoinositide 3-kinase (PI3-K). Exposure of HepG2 cells to IGF-I elicited a rapid phosphorylation of Akt. We also demonstrated that the constitutively active form of both p110, a subunit of PI3-K, and Akt inhibited activity of the human SR-BI/CLA-1 promoter. Furthermore, the dominant-negative mutant of Akt abolished the ability of IGF-I to suppress activity of the SR-BI/CLA-1 promoter. In conclusion, PI3-K/Akt pathways participate in IGF-I-suppression of SR-BI/CLA-1 expression, which suggests that the activation of Akt plays an important role in cholesterol metabolism in liver.

Corticosteroid refractory radiation pneumonitis that remarkably responded to cyclosporin A.

Radiation therapy is commonly used for the treatment of lung cancer. However, radiation pneumonitis frequently occurs as a complication of the radiation therapy. Although corticosteroids are widely used for the treatment of radiation pneumonitis, they are not always effective. In this report, we used cyclosporin A in the treatment of a patient suffering from steroid-refractory radiation pneumonitis. To our knowledge, this is the first report in which cyclosporin A was successfully used in the treatment of radiation pneumonitis.