Fatal pulmonary embolism after surgery for small intestinal necrosis caused by idiopathic portal vein thrombosis: a case report.

BACKGROUND: Portal vein thrombosis (PVT) and venous thromboembolism (VTE) both result from partial or complete occlusion of a blood vessel by a blood clot. The prognosis of PVT is generally good; however, PVT with VTE, including pulmonary embolism (PE), has a high mortality rate. We report here a case of PE after surgery for small intestinal necrosis caused by idiopathic PVT. CASE PRESENTATION: A 69-year-old female attended our hospital with a chief complaint of upper abdominal discomfort, and was diagnosed with necrosis of the small intestine as a result of unexplained PVT. She underwent partial resection of the small intestine. On the second postoperative day, she suffered from respiratory distress and went into cardiopulmonary arrest. The patient recovered following cardiopulmonary resuscitation, but PE was detected. Extracorporeal veno-arterial cardiopulmonary resuscitation and anticoagulation therapy were initiated immediately and the thrombus was aspirated as much as possible. Two days later, extracorporeal veno-arterial cardiopulmonary resuscitation was withdrawn and anticoagulation therapy was continued. The patient subsequently recovered with no neurological damage and was discharged on day 26 after the above procedure. CONCLUSIONS: Idiopathic PVT is often associated with VTE, and a prompt diagnosis and intervention may result in a good prognosis.

Hand-assisted laparoscopic splenectomy and gastropancreatic fold division: a less-invasive simplified technique of Hassab's procedure for refractory esophagogastric varices.

Some patients with refractory esophagogastric varices require surgery, such as gastric devascularization and splenectomy (Hassab's procedure). However, these patients are at risk of perioperative morbidities when undergoing devascularization to develop collateral vessels. We performed a more simplified procedure, splenectomy, and en bloc gastropancreatic fold division (GPFD) with hand-assisted laparoscopic surgery. Four patients with refractory esophagogastric varices and portal hypertension underwent splenectomy and GPFD. We reviewed patients' perioperative laboratory and morphological data, operative variables, and postoperative outcomes. Esophagogastric varices improved in 3 (75%) of the 4 patients. In one patient, esophageal varices (F1RC0) were observed 3 years after surgery, but they required no treatment and only received follow-up. Treatment with splenectomy and GPFD is not only less invasive than Hassab's procedure but also provides effective outcomes for refractory esophagogastric varices.

L-Asparaginase-Induced Continuous Hyperglycemia With Type 1 Diabetes-Related Antibodies and HLA Genotypes: A Case Study.

A 19-year-old male presented with fatigue and dyspnea on exertion. He was diagnosed with acute T-cell lymphoblastic leukemia. After following the Group for Research on Adult Acute Lymphoblastic Leukemia (GRAALL) 2003 protocol that incorporates L-asparaginase (L-Asp) treatment, blood glucose levels became elevated for more than one year and insulin secretion was depleted. Anti-glutamic acid decarboxylase (GAD) and anti-islet antigen 2 (IA-2) antibody levels were both positive, which is rare. The patient's HLA genotype was sensitive for type 1 diabetes. L-Asp can cause transient hyperglycemia as a side effect. However, cases with the anti-GAD antibody have not been reported in L-Asp-induced diabetes. In summary, L-Asp-induced continuous hyperglycemia might be associated with a type 1 diabetes-related HLA genotype through elevations of anti-GAD and anti-IA-2 antibodies.

The Burden of Preventable Adverse Drug Events on Hospital Stay and Healthcare Costs in Japanese Pediatric Inpatients: The JADE Study.

BACKGROUND: Adverse drug events (ADEs) are a burden to the healthcare system. Preventable ADEs, which was ADEs due to medication errors, could be reduced if medication errors can be prevent or ameliorate. OBJECTIVE: We investigated the burden of preventable ADEs on the length of hospital stay (LOS) and costs, and estimated the national burden of preventable ADEs in pediatric inpatients in Japan. METHODS: We analyzed data from the Japan Adverse Drug Events (JADE) study on pediatric patients and estimated the incidence of preventable ADEs and associated extended LOS. Costs attributable to extended LOS by preventable ADEs were calculated using a national statistics database and we calculated the effect of preventable ADEs on national cost excess. RESULTS: We included 907 patients with 7377 patient-days. Among them, 31 patients (3.4%) experienced preventable ADEs during hospitalization. Preventable ADEs significantly increased the LOS by 14.1 days, adjusting for gender, age, ward, resident physician, surgery during hospitalization, cancer, and severe malformation at birth. The individual cost due to the extended LOS of 14.1 days was estimated as USD 8258. We calculated the annual extra expense for preventable ADEs in Japan as USD 329 676 760. Sensitivity analyses, considering the incidence of preventable ADEs and the length of hospital stay, showed that the expected range of annual extra expense for preventable ADEs in Japan is between USD 141 468 968 and 588 450 708. CONCLUSION: Preventable ADEs caused longer hospitalization and considerable extra healthcare costs in pediatric inpatients. Our results would encourage further efforts to prevent and ameliorate preventable ADEs.

Deciphering genetic signatures by whole exome sequencing in a case of co-prevalence of severe renal hypouricemia and diabetes with impaired insulin secretion.

BACKGROUND: Renal hypouricemia (RHUC) is a hereditary disorder where mutations in SLC22A12 gene and SLC2A9 gene cause RHUC type 1 (RHUC1) and RHUC type 2 (RHUC2), respectively. These genes regulate renal tubular reabsorption of urates while there exist other genes counterbalancing the net excretion of urates including ABCG2 and SLC17A1. Urate metabolism is tightly interconnected with glucose metabolism, and SLC2A9 gene may be involved in insulin secretion from pancreatic ß-cells. On the other hand, a myriad of genes are responsible for the impaired insulin secretion independently of urate metabolism. CASE PRESENTATION: We describe a 67 year-old Japanese man who manifested severe hypouricemia (0.7 mg/dl (3.8-7.0 mg/dl), 41.6 µmol/l (226-416 µmol/l)) and diabetes with impaired insulin secretion. His high urinary fractional excretion of urate (65.5%) and low urinary C-peptide excretion (25.7 µg/day) were compatible with the diagnosis of RHUC and impaired insulin secretion, respectively. Considering the fact that metabolic pathways regulating urates and glucose are closely interconnected, we attempted to delineate the genetic basis of the hypouricemia and the insulin secretion defect observed in this patient using whole exome sequencing. Intriguingly, we found homozygous Trp258* mutations in SLC22A12 gene causing RHUC1 while concurrent mutations reported to be associated with hyperuricemia were also discovered including ABCG2 (Gln141Lys) and SLC17A1 (Thr269Ile). SLC2A9, that also facilitates glucose transport, has been implicated to enhance insulin secretion, however, the non-synonymous mutations found in SLC2A9 gene of this patient were not dysfunctional variants. Therefore, we embarked on a search for causal mutations for his impaired insulin secretion, resulting in identification of multiple mutations in HNF1A gene (MODY3) as well as other genes that play roles in pancreatic ß-cells. Among them, the Leu80fs in the homeobox gene NKX6.1 was an unreported mutation. CONCLUSION: We found a case of RHUC1 carrying mutations in SLC22A12 gene accompanied with compensatory mutations associated with hyperuricemia, representing the first report showing coexistence of the mutations with opposed potential to regulate urate concentrations. On the other hand, independent gene mutations may be responsible for his impaired insulin secretion, which contains novel mutations in key genes in the pancreatic ß-cell functions that deserve further scrutiny.

Hepatocyte ELOVL Fatty Acid Elongase 6 Determines Ceramide Acyl-Chain Length and Hepatic Insulin Sensitivity in Mice.

BACKGROUND AND AIMS: Dysfunctional hepatic lipid metabolism is a cause of nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disorder worldwide, and is closely associated with insulin resistance and type 2 diabetes. ELOVL fatty acid elongase 6 (Elovl6) is responsible for converting C16 saturated and monounsaturated fatty acids (FAs) into C18 species. We have previously shown that Elovl6 contributes to obesity-induced insulin resistance by modifying hepatic C16/C18-related FA composition. APPROACH AND RESULTS: To define the precise molecular mechanism by which hepatic Elovl6 affects energy homeostasis and metabolic disease, we generated liver-specific Elovl6 knockout (LKO) mice. Unexpectedly, LKO mice were not protected from high-fat diet-induced insulin resistance. Instead, LKO mice exhibited higher insulin sensitivity than controls when consuming a high-sucrose diet (HSD), which induces lipogenesis. Hepatic patatin-like phospholipase domain-containing protein 3 (Pnpla3) expression was down-regulated in LKO mice, and adenoviral Pnpla3 restoration reversed the enhancement in insulin sensitivity in HSD-fed LKO mice. Lipidomic analyses showed that the hepatic ceramide(d18:1/18:0) content was lower in LKO mice, which may explain the effect on insulin sensitivity. Ceramide(d18:1/18:0) enhances protein phosphatase 2A (PP2A) activity by interfering with the binding of PP2A to inhibitor 2 of PP2A, leading to Akt dephosphorylation. Its production involves the formation of an Elovl6-ceramide synthase 4 (CerS4) complex in the endoplasmic reticulum and a Pnpla3-CerS4 complex on lipid droplets. Consistent with this, liver-specific Elovl6 deletion in ob/ob mice reduced both hepatic ceramide(d18:1/18:0) and PP2A activity and ameliorated insulin resistance. CONCLUSIONS: Our study demonstrates the key role of hepatic Elovl6 in the regulation of the acyl-chain composition of ceramide and that C18:0-ceramide is a potent regulator of hepatic insulin signaling linked to Pnpla3-mediated NAFLD.

Transcriptional co-repressor CtBP2 orchestrates epithelial-mesenchymal transition through a novel transcriptional holocomplex with OCT1.

The epithelial to mesenchymal transition (EMT) is a cell intrinsic program controlling cellular morphological and phenotypic remodeling in a wide range of biological processes. Despite the accumulating evidence, the transcriptional networks regulating EMT still remain to be elucidated. In this study, we demonstrate that C-terminal binding protein 2 (CtBP2), a critical transcriptional co-repressor harboring pyridine nucleotide sensing capability, orchestrates the EMT program at least in part through a novel transcriptional interaction with an octamer transcription factor, OCT1 (POU2F1, POU class 2 homeobox 1). We identified novel interactions of CtBP2 with several octamer transcription factors, and CtBP2 exhibits a direct interaction with OCT1 in particular. OCT1 accelerates the EMT program as reported, which is diminished by the mutation of the CtBP-binding motif in OCT1, suggesting OCT1 represses epithelial gene expression through recruiting the co-repressor CtBP2. In accordance with these findings, a canonical EMT activator transforming growth factor-ß (TGF-ß) promotes the formation of the CtBP2/OCT1 complex. Our observations illustrate the role of CtBP2 to orchestrate the EMT program through the interaction with OCT1 and highlight the potential of therapeutic exploitation of this new transcriptional system for a wide range of diseases.

Glucocorticoid receptor suppresses gene expression of Rev-erbα (Nr1d1) through interaction with the CLOCK complex.

Glucocorticoids have various medical uses but are accompanied by side effects. The glucocorticoid receptor (GR) has been reported to regulate the clock genes, but the underlying mechanisms are incompletely understood. In this study, we focused on the suppressive effect of the GR on the expression of Rev-erbα (Nr1d1), an important component of the clock regulatory circuits. Here we show that the GR suppresses Rev-erbα expression via the formation of a complex with CLOCK and BMAL1, which binds to the E-boxes in the Nr1d1 promoter. In this GR-CLOCK-BMAL1 complex, the GR does not directly bind to DNA, which is referred to as tethering. These findings provide new insights into the role of the GR in the control of circadian rhythm.

Transgenic Mice Overexpressing SREBP-1a in Male ob/ob Mice Exhibit Lipodystrophy and Exacerbate Insulin Resistance.

Sterol regulatory element-binding protein (SREBP)-1a is a key transcription factor that activates the expression of genes involved in the synthesis of fatty acids, triglycerides (TGs), and cholesterol. Transgenic mice that overexpress the nuclear form of SREBP-1a under the control of the phosphoenolpyruvate carboxykinase promoter (Tg-1a) were previously shown to display a lipodystrophic phenotype characterized by enlarged and fatty livers, diminished peripheral white adipose tissue (WAT), and insulin resistance. In the current study, we crossed these Tg-1a mice with genetically obese (ob/ob) mice (Tg-1a;ob/ob) and examined change in fat distribution between liver and adipose tissues in severe obesity and mechanism underlying the lipodystrophic phenotype in mice with Tg-1a. Tg-1a;ob/ob mice developed more severe steatohepatitis but had reduced WAT mass and body weight compared with ob/ob mice. The reduction of WAT mass in Tg-1a and Tg-1a;ob/ob mice was accompanied by enhanced lipogenesis and lipid uptake in the liver, reduced plasma lipid levels, impaired adipocyte differentiation, reduced food intake, enhanced energy expenditure, and extended macrophage infiltration and fibrosis in WAT. Despite the improved glucose tolerance, Tg-1a;ob/ob mice showed severe peripheral insulin resistance. Adenoviral hepatic expression of SREBP-1a mimicked these phenotypes. The "fat steal"-like lipodystrophy phenotype of the Tg-1a;ob/ob model demonstrates that hepatic SREBP-1a activation has a strong impact on the partition of TG accumulation, resulting in adipose-tissue remodeling by inflammation and fibrosis and insulin resistance.

A candidate functional SNP rs7074440 in TCF7L2 alters gene expression through C-FOS in hepatocytes.

The SNP rs7903146 at the transcription factor 7-like 2 (TCF7L2) locus is established as the strongest known genetic marker for type 2 diabetes via genome-wide association studies. However, the functional SNPs regulating TCF7L2 expression remain unclear. Here, we show that the SNP rs7074440 is a candidate functional SNP highly linked with rs7903146. A reporter plasmid with rs7074440 normal allele sequence exhibited 15-fold higher luciferase activity compared with risk allele sequence in hepatocytes, demonstrating a strong enhancer activity at rs7074440. Additionally, we identified C-FOS as an activator binding to the rs7074440 enhancer using a TFEL genome-wide screen method. Consistently, knockdown of C-FOS significantly reduced TCF7L2 expression in hepatocytes. Collectively, a novel enhancer regulating TCF7L2 expression was revealed through searching for functional SNPs.

A Rare Coexistence of Pheochromocytoma and Parkinson's Disease With Diagnostic Challenges.

We herein report a case of pheochromocytoma occurring in the course of Parkinson's disease. The coexistence of these two disease is extremely rare, with only four cases hitherto reported across the public databases. It is also noteworthy that biochemical tests, which are critical for the diagnosis of pheochromocytoma, are severely confounded by dopaminergic medications for Parkinson's disease, highlighting the importance of image-based modalities in this setting. We further attempted to gain insight into the potential molecular mechanisms, proposing that hypoxia-inducible factor signaling could make these two diseases mutually exclusive, while excessive reactive oxygen species could enable their coexistence.

CREB3L3 controls fatty acid oxidation and ketogenesis in synergy with PPARα.

CREB3L3 is involved in fatty acid oxidation and ketogenesis in a mutual manner with PPARα. To evaluate relative contribution, a combination of knockout and transgenic mice was investigated. On a ketogenic-diet (KD) that highlights capability of hepatic ketogenesis, Creb3l3-/- mice exhibited reduction of expression of genes for fatty oxidation and ketogenesis comparable to Ppara-/- mice. Most of the genes were further suppressed in double knockout mice indicating independent contribution of hepatic CREB3L3. During fasting, dependency of ketogenesis on CREB3L3 is lesser extents than Ppara-/- mice suggesting importance of adipose PPARα for supply of FFA and hyperlipidemia in Creb3l3-/- mice. In conclusion CREB3L3 plays a crucial role in hepatic adaptation to energy starvation via two pathways: direct related gene regulation and an auto-loop activation of PPARα. Furthermore, as KD-fed Creb3l3-/- mice exhibited severe fatty liver, activating inflammation, CREB3L3 could be a therapeutic target for NAFLD.

Intestinal CREBH overexpression prevents high-cholesterol diet-induced hypercholesterolemia by reducing Npc1l1 expression.

OBJECTIVE: The transcription factor cyclic AMP-responsive element-binding protein H (CREBH, encoded by Creb3l3) is highly expressed in the liver and small intestine. Hepatic CREBH contributes to glucose and triglyceride metabolism by regulating fibroblast growth factor 21 (Fgf21) expression. However, the intestinal CREBH function remains unknown. METHODS: To investigate the influence of intestinal CREBH on cholesterol metabolism, we compared plasma, bile, fecal, and tissue cholesterol levels between wild-type (WT) mice and mice overexpressing active human CREBH mainly in the small intestine (CREBH Tg mice) under different dietary conditions. RESULTS: Plasma cholesterol, hepatic lipid, and cholesterol crystal formation in the gallbladder were lower in CREBH Tg mice fed a lithogenic diet (LD) than in LD-fed WTs, while fecal cholesterol output was higher in the former. These results suggest that intestinal CREBH overexpression suppresses cholesterol absorption, leading to reduced plasma cholesterol, limited hepatic supply, and greater excretion. The expression of Niemann-Pick C1-like 1 (Npc1l1), a rate-limiting transporter mediating intestinal cholesterol absorption, was reduced in the small intestine of CREBH Tg mice. Adenosine triphosphate-binding cassette transporter A1 (Abca1), Abcg5/8, and scavenger receptor class B, member 1 (Srb1) expression levels were also reduced in CREBH Tg mice. Promoter assays revealed that CREBH directly regulates Npc1l1 expression. Conversely, CREBH null mice exhibited higher intestinal Npc1l1 expression, elevated plasma and hepatic cholesterol, and lower fecal output. CONCLUSION: Intestinal CREBH regulates dietary cholesterol flow from the small intestine by controlling the expression of multiple intestinal transporters. We propose that intestinal CREBH could be a therapeutic target for hypercholesterolemia.

[Two Cases of Germ Cell Tumors with Hyperthyroidism Due to High Serum hCGLevels].

We reported two cases of hyperthyroidism that developed during induction chemotherapy for advanced germ cell tumors with high serum human chorionic gonadotropin (hCG) levels. Case 1 : An 18-year-old man with mediastinal choriocarcinoma complained of tachycardia and tremor. His pretreatment serum hCG level was 1.37 million mIU/ml. The free thyroxine (fT4) level measured on day 2 of the first course of bleomycin, etoposide and cisplatin (BEP) was elevated to 7.8 ng/dl (＜1.7 ng/dl), whereasthe thyroidstimulating hormone (TSH) level was undetectable. We diagnosed the patient with hyperthyroidism and started oral propranolol and thiamazole. Subsequently, his tachycardia and tremor disappeared. On day 12 of the first course of BEP, his hCG level decreased to less than 50,000 mIU/ml. Also, his fT4 level returned to the normal range. Case 2 : A 29-year-old man presented with a left scrotal mass. He was diagnosed with non-seminoma testicular cancer (embryonal carcinoma and choriocarcinoma) with multiple lung, liver and lymph node metastases. On the admission day, his serum hCG and fT4 levels were high ; 3.23 million mIU/ml and 2.2 ng/dl, respectively. The TSH level was low at 0.011 mIU/ml. On day 3 of the first course of BEP, his hCG and fT4 levels increased to 4.5 million mIU/ml and 3.0 ng/dl, respectively. He complained of tachycardia, tremor and hyperhydrosis. He was started on propranolol and potassium iodide. After the treatment, histachycardia, tremor and hyperhidrosisdis appeared. HisfT4 level normalized on day 17 of the first course of BEP. The TSH-like activity of hCG is considered to be responsible for paraneoplastic hyperthyroidism among germ cell cancer patients with high hCG levels. To our knowledge, thisisthe first report of such a case in Japan. However, thisphenomenon isnot rare among patients with extremely high hCG levels. Therefore, we should be careful of these patients.

Different Effects of Eicosapentaenoic and Docosahexaenoic Acids on Atherogenic High-Fat Diet-Induced Non-Alcoholic Fatty Liver Disease in Mice.

Non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of metabolic syndrome, can progress to steatohepatitis (NASH) and advanced liver damage, such as that from liver cirrhosis and cancer. Recent studies have shown the benefits of consuming n-3 polyunsaturated fatty acids (PUFAs) for the treatment of NAFLD. In the present study, we investigated and compared the effects of the major n-3 PUFAs-eicosapentaenoic acid (EPA, C20:5) and docosahexaenoic acid (DHA, C22:6)-in preventing atherogenic high-fat (AHF) diet-induced NAFLD. Mice were fed the AHF diet supplemented with or without EPA or DHA for four weeks. Both EPA and DHA reduced the pathological features of AHF diet-induced NASH pathologies such as hepatic lobular inflammation and elevated serum transaminase activity. Intriguingly, EPA had a greater hepatic triacylglycerol (TG)-reducing effect than DHA. In contrast, DHA had a greater suppressive effect than EPA on AHF diet-induced hepatic inflammation and ROS generation, but no difference in fibrosis. Both EPA and DHA could be effective for treatment of NAFLD and NASH. Meanwhile, the two major n-3 polyunsaturated fatty acids might differ in a relative contribution to pathological intermediate steps towards liver fibrosis.

Absence of Elovl6 attenuates steatohepatitis but promotes gallstone formation in a lithogenic diet-fed Ldlr(-/-) mouse model.

Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) that can develop into liver cirrhosis and cancer. Elongation of very long chain fatty acids (ELOVL) family member 6 (Elovl6) is a microsomal enzyme that regulates the elongation of C12-16 saturated and monounsaturated fatty acids (FAs). We have previously shown that Elovl6 plays an important role in the development of hepatic insulin resistance and NASH by modifying FA composition. Recent studies have linked altered hepatic cholesterol homeostasis and cholesterol accumulation to the pathogenesis of NASH. In the present study, we further investigated the role of Elovl6 in the progression of lithogenic diet (LD)-induced steatohepatitis. We showed that the absence of Elovl6 suppresses hepatic lipid accumulation, plasma total cholesterol and total bile acid (BA) levels in LDL receptor-deficient (Ldlr(-/-)) mice challenged with a LD. The absence of Elovl6 also decreases hepatic inflammation, oxidative stress and liver injury, but increases the formation of cholesterol crystals in the less dilated gallbladder. These findings suggest that Elovl6-mediated changes in hepatic FA composition, especially oleic acid (C18:1n-9), control handling of hepatic cholesterol and BA, which protects against hepatotoxicity and steatohepatitis, but promotes gallstone formation in LD-fed Ldlr(-/-) mice.

Hepatic CREB3L3 controls whole-body energy homeostasis and improves obesity and diabetes.

Transcriptional regulation of metabolic genes in the liver is the key to maintaining systemic energy homeostasis during starvation. The membrane-bound transcription factor cAMP-responsive element-binding protein 3-like 3 (CREB3L3) has been reported to be activated during fasting and to regulate triglyceride metabolism. Here, we show that CREB3L3 confers a wide spectrum of metabolic responses to starvation in vivo. Adenoviral and transgenic overexpression of nuclear CREB3L3 induced systemic lipolysis, hepatic ketogenesis, and insulin sensitivity with increased energy expenditure, leading to marked reduction in body weight, plasma lipid levels, and glucose levels. CREB3L3 overexpression activated gene expression levels and plasma levels of antidiabetic hormones, including fibroblast growth factor 21 and IGF-binding protein 2. Amelioration of diabetes by hepatic activation of CREB3L3 was also observed in several types of diabetic obese mice. Nuclear CREB3L3 mutually activates the peroxisome proliferator-activated receptor (PPAR) α promoter in an autoloop fashion and is crucial for the ligand transactivation of PPARα by interacting with its transcriptional regulator, peroxisome proliferator-activated receptor gamma coactivator-1α. CREB3L3 directly and indirectly controls fibroblast growth factor 21 expression and its plasma level, which contributes at least partially to the catabolic effects of CREB3L3 on systemic energy homeostasis in the entire body. Therefore, CREB3L3 is a therapeutic target for obesity and diabetes.

TFE3 controls lipid metabolism in adipose tissue of male mice by suppressing lipolysis and thermogenesis.

Transcription factor E3 (TFE3) is a transcription factor that binds to E-box motifs and promotes energy metabolism-related genes. We previously reported that TFE3 directly binds to the insulin receptor substrate-2 promoter in the liver, resulting in increased insulin response. However, the role of TFE3 in other tissues remains unclear. In this study, we generated adipose-specific TFE3 transgenic (aP2-TFE3 Tg) mice. These mice had a higher weight of white adipose tissue (WAT) and brown adipose tissue than wild-type (WT) mice under fasting conditions. Lipase activity in the WAT in these mice was lower than that in the WT mice. The mRNA level of adipose triglyceride lipase (ATGL), the rate-limiting enzyme for adipocyte lipolysis, was significantly decreased in aP2-TFE3 Tg mice. The expression of Foxo1, which directly activates ATGL expression, was also suppressed in transgenic mice. Promoter analysis confirmed that TFE3 suppressed promoter activities of the ATGL gene. In contrast, G0S2 and Perilipin1, which attenuate ATGL activity, were higher in transgenic mice than in WT mice. These results indicated that the decrease in lipase activity in adipose tissues was due to a decrease in ATGL expression and suppression of ATGL activity. We also showed that thermogenesis was suppressed in aP2-TFE3 Tg mice. The decrease in lipolysis in WAT of aP2-TFE3 Tg mice inhibited the supply of fatty acids to brown adipose tissue, resulting in the inhibition of the expression of thermogenesis-related genes such as UCP1. Our data provide new evidence that TFE3 regulates lipid metabolism by controlling the gene expression related to lipolysis and thermogenesis in adipose tissue.

TFE3 inhibits myoblast differentiation in C2C12 cells via down-regulating gene expression of myogenin.

Transcription factor E3 (TFE3) belongs to a basic helix-loop-helix family, and is involved in the biology of osteoclasts, melanocytes and their malignancies. We previously reported the metabolic effects of TFE3 on insulin in the liver and skeletal muscles in animal models. In the present study, we explored a novel role for TFE3 in a skeletal muscle cell line. When TFE3 was overexpressed in C2C12 myoblasts by adenovirus before induction of differentiation, myogenic differentiation of C2C12 cells was significantly inhibited. Adenovirus-mediated TFE3 overexpression also suppressed the gene expression of muscle regulatory factors (MRFs), such as MyoD and myogenin, during C2C12 differentiation. In contrast, knockdown of TFE3 using adenovirus encoding short-hairpin RNAi specific for TFE3 dramatically promoted myoblast differentiation associated with significantly increased expression of MRFs. Consistent with these findings, promoter analyses via luciferase reporter assay and electrophoretic mobility shift assay suggested that TFE3 negatively regulated myogenin promoter activity by direct binding to an E-box, E2, in the myogenin promoter. These findings indicated that TFE3 has a regulatory role in myoblast differentiation, and that transcriptional suppression of myogenin expression may be part of the mechanism of action.

A case of acute adrenal insufficiency unmasked during sunitinib treatment for metastatic renal cell carcinoma.

Sunitinib has recently become a standard treatment for metastatic renal cell carcinoma. However, various adverse events have been reported. We present the first case of clinically evident adrenal insufficiency during sunitinib therapy. A 72-year-old man began sunitinib therapy for bilateral lung and adrenal metastases of renal cell carcinoma. His adrenocorticotrophic hormone level was 93.6 pg/ml (7.2-63.3 pg/ml) before sunitinib treatment, indicating that subclinical adrenal insufficiency already existed. Fatigue, which is a frequently seen adverse effect of sunitinib treatment, emerged acutely on Day 24 of the second cycle. Adrenocorticotrophic hormone and free T4 were high and thyroid-stimulating hormone was suppressed. Under the clinical diagnosis of acute adrenal insufficiency with thyrotoxicosis, a low dose of steroid was administered. Fatigue was completely ameliorated by the following morning, although free T4 was still high and thyroid-stimulating hormone was still low. Therefore, hypermetabolism due to thyrotoxicosis unmasked adrenal insufficiency in our case. Physicians should be aware of this rare but potentially fatal complication when severe acute fatigue develops in patients with subclinical adrenal insufficiency.