Mitochondrial KATP channel-mediated autophagy contributes to angiotensin II-induced vascular dysfunction in mice

BACKGROUND AND AIM

The present study aimed to investigate whether the mitochondrial KATP channel contributes to angiotensin II (Ang II)-induced vascular dysfunction, the development of hypertension, and atherosclerosis.

METHODS AND RESULTS

ApoE (-/-) mice fed a high-fat diet were chronically infused with Ang II for eight weeks and concomitantly treated with losartan (ARB), apocynin, or 5-hydroxy decanoate (5-HD), or 3-methyladenine (3-MA). Systolic blood pressure was measured, and pathological changes of aortic or liver tissue were observed. Nitric oxide (NO), superoxide dismutase 2 (SOD2) levels and vasorelaxation rate were measured, and protein and mRNA expressions were examined by western blot and RT-PCR. Ang II-induced development of hypertension was suppressed not only by ARB, and apocynin but also by 5-HD or 3-MA. Ang II infusion decreased aortic NO production and relaxation, as well as SOD2 activity in liver, which were improved by all treatments. In addition, Ang II-induced activation of autophagy was suppressed by 5-HD in aortic tissue, furthermore, Ang II increases the atherosclerotic index in plasma and exacerbates the development of atherosclerosis by increases of fat deposition in the aorta and liver. Lipid metabolism-related mRNA expressions (LXR-α, LDLR, SRBI, Acca, and FASN) were changed by Ang II. Similarly, not only ARB, and apocynin, but also 5-HD and 3-MA suppressed Ang II-induced these changes.

CONCLUSIONS

Our present findings evidence that mitochondrial KATP channel-mediated autophagy contributes to Ang II-induced vascular dysfunction, development of hypertension, and atherosclerosis.

A Pilot Study on the Efficacy of a Diabetic Diet Containing the Rare Sugar D-Allulose in Patients with Type 2 Diabetes Mellitus: A Prospective, Randomized, Single-Blind, Crossover Study

High sugar consumption increases the risk of diabetes, obesity, and cardiovascular diseases. Regarding the diet of patients with diabetes, artificial sweeteners are considered a safe alternative to sugar; however, there is also a risk that artificial sweeteners exacerbate glucose metabolism. D-allulose (C-3 isomer of d-fructose), which is a rare sugar, has been reported to have antidiabetic and antiobesity effects. In this study, the efficacy of a diabetic diet containing D-allulose was investigated in patients with type 2 diabetes using an intermittently scanned continuous glucose monitoring system (isCGM). This study was a validated, prospective, single-blind, randomized, crossover comparative study. Comparison of peak postprandial blood glucose (PPG) levels after consumption of a standard diabetic diet and a diabetic diet containing 8.5 g of D-allulose was the primary endpoint. A D-allulose-containing diabetic diet improved PPG levels in type two diabetes patients compared with a strictly energy-controlled diabetic diet. The results also showed a protective effect on endogenous pancreatic insulin secretory capacity owing to reduced insulin requirement. In patients with type two diabetes mellitus, diabetic diets containing 8.5 g D-allulose were effective in improving PPG levels.

Quantitative effects of bilirubin structural photoisomers on the measurement of direct bilirubin via the vanadate oxidation method

BACKGROUND

Exposing blood serum samples to ambient white light-emitting diode (WLED) light may accelerate bilirubin photoisomer production. We previously demonstrated the quantitative effect of bilirubin configurational isomers (BCI) on direct bilirubin (DB) value using the vanadate oxidation method. However, the effects of bilirubin structural photoisomers (BSI) remain unclear.

METHODS

In Study 1, the relationship between WLED irradiation time and BSI production was examined. Serum samples from five neonates were irradiated with WLED light for 0, 10, 30, 60 and 180 min. Bilirubin isomer concentration and BSI production rates were calculated. In Study 2, we performed quantitative investigation of BSI effect on DB values: Differences in DB, BCI and BSI values before and after irradiation were calculated as ⊿DB, ⊿BCI and ⊿BSI, respectively. Assuming the coefficient of BCI affecting DB values was 'a', relational expression was ⊿DB = a*⊿BSI + 0.19*⊿BCI. Serum samples from 15 neonates were irradiated with green LED light for 10 and 30 s. The respective bilirubin isomer levels were measured, and the coefficient was derived.

RESULTS

In Study 1, the median BSI production rate was 0.022 mg/dL per min in specimens with an unconjugated bilirubin concentration of 10.88 mg/dL. In Study 2, assuming that ⊿DB-0.19*⊿BCI was Y and ⊿BSI was X, the relational expression was Y = 0.34X-0.03 (R² = 0.87; p < .01) and a = 0.34.

CONCLUSIONS

Under ambient WLED light, serum sample generated 1.3 mg/dL BSIs in 1 h. Approximately 34% (0.44 mg/dL) of BSI concentrations was measured as DB when using the vanadate oxidation method according to the above equation.

Effect of chronic exposure to ketohexoses on pancreatic β-cell function in INS-1 rat insulinoma cells

Glucotoxicity, impaired insulin secretion, suppression of insulin gene expression, and apoptosis, in pancreatic β-cells caused by chronic hyperglycemia is a key component of the pathogenesis of type 2 diabetes. Recently, it has been reported that rare sugar d-allulose has antihyperglycemic and antihyperlipidemic effects in diabetic rats. However, the direct effects of rare sugars including d-allulose on pancreatic β-cell function are unclear. In this study, we investigated whether chronic exposure to ketohexoses causes glucotoxicity, suppression of insulin gene expression, and apoptosis, in INS-1 rat pancreatic insulinoma cells. d-Fructose, d-tagatose, l-allulose, and l-sorbose treatment for 1-week reduced insulin gene expression, whereas d-allulose, d-sorbose, l-fructose, and l-tagatose did not. All ketohexoses were transported into INS-1 cells, but were not metabolized. In addition, the ketohexoses did not induce apoptosis and did not affect glucose metabolism. These results suggest that long-term administration of d-allulose, d-sorbose, l-fructose, and l-tagatose does not affect pancreatic β-cell function.

Knowledge of diabetes and the practice of diabetes self-management during Ramadan fasting among patients with type 2 diabetes in Malaysia

BACKGROUND AND AIMS

To assess the level of diabetes knowledge and its association with diabetes self-management practices during Ramadan fasting among patients with type 2 diabetes (T2D).

METHODS

A cross-sectional study was conducted involving a sample of Malaysian patients with T2D. Patients aged 18 years and above, and attending an outpatient diabetic unit of a government hospital were recruited between February and April 2021. A self-administered questionnaire was utilized to assess diabetes knowledge and diabetes self-management practices.

RESULTS

A total of 306 participants completed the questionnaire. Most of them were females (54.2%) and above 55 years old (75.1%). Resultantly, knowledge of diabetes was considered average among 52% of the participants. Only 9.5% of them avoided the consumption of sweet foods during iftar. Practicing late suhoor (p = 0.012) and self-monitoring of blood glucose (SMBG) (p = 0.026) during Ramadan were significantly associated with a better diabetes knowledge score. Education level (p = 0.000), working status (p = 0.030), and monthly income (p = 0.000) were significantly associated with participants' knowledge level of diabetes. A higher proportion (72.2%) of the participants completed fasting for a month during Ramadan 2020. Meanwhile, hypoglycemia was the main reason (38.8%) for incomplete fasting.

CONCLUSIONS

These findings reflect the need to improve patients' knowledge of diabetes and diabetes self-management practices, especially during Ramadan. Such objectives could be achieved by considering the associated factors identified in this study.

A pilot study on the effect of D-allulose on postprandial glucose levels in patients with type 2 diabetes mellitus during Ramadan fasting

BACKGROUND

During Ramadan fasting, postprandial hyperglycemia is commonly observed after iftar (break of fast at sunset) meal. D-allulose is a rare sugar and is reported to have several health benefits, including the suppression of increase in postprandial glucose levels. This study investigates whether D-allulose (a C-3 epimer of D-fructose) improves the postprandial glucose in patients with type 2 diabetes mellitus (T2DM) during Ramadan.

METHODS

This was a pilot, prospective single-arm study design that was conducted for 10 consecutive days; 5 days of control and 5 days of consumption. The primary outcome was postprandial peak glucose levels. During the consumption period, 8.5 g of D-allulose was consumed by the participants before iftar meal. Postprandial glucose was measured using a continuous glucose monitoring system.

RESULTS

A total of 12 participants completed the study. Significant lower (p < 0.01) postprandial glucose values and the glucose incremental area under the curve (iAUC) were observed from 0 to 180 min during the consumption period compared to the control period. The consumption period demonstrated significantly higher percentages of time in which glucose values were found in the target range (p = 0.0032), and when the glucose levels above the target range were reduced (p = 0.0015).

CONCLUSIONS

The supplementation with D-allulose has the potential to improve postprandial hyperglycemia in patients with T2DM after iftar during Ramadan. Further studies are needed to confirm these findings. Trial registration ClinicalTrials.gov NCT05071950. Retrospectively registered, 8 October 2021.

Effects of 2-Methoxyestradiol, a Main Metabolite of Estradiol on Hepatic ABCA1 Expression in HepG2 Cells

ATP-binding cassette transporter A1 (ABCA1) is a key regulator of lipid efflux, and the absence of ABCA1 induces hepatic lipid accumulation, which is one of the major causes of fatty liver. 2-Methoxyestradiol (2-ME₂) has been demonstrated to protect against fatty liver. In this study, we investigated the effects of 2-ME₂ on the hepatic lipid content and ABCA1 expression. We found that 2-ME₂ dose-dependently increased ABCA1 expression, and therefore, the lipid content was significantly decreased in HepG2 cells. 2-ME₂ enhanced the ABCA1 promoter activity; however, this effect was reduced after the inhibition of the PI3K pathway. The overexpression of Akt or p110 induced ABCA1 promoter activity, while dominant-negative Akt diminished the ability of 2-ME₂ on ABCA1 promoter activity. Further, 2-ME₂ stimulated the rapid phosphorylation of Akt and FoxO1 and reduced the nuclear accumulation of FoxO1. Chromatin immunoprecipitation confirmed that FoxO1 bonded to the ABCA1 promoter region. The binding was reduced by 2-ME₂, which facilitated ABCA1 gene transcription. Furthermore, mutating FoxO1-binding sites in the ABCA1 promoter region or treatment with FoxO1-specific siRNA disrupted the effect of 2-ME₂ on ABCA1 expression. All of our results demonstrated that 2-ME₂ might upregulate ABCA1 expression via the PI3K/Akt/FoxO1 pathway, which thus reduces the lipid content in hepatocytes.

HDL promotes adiponectin gene expression via the CAMKK/CAMKIV pathway

Adiponectin (APN) is an adipokine that protects against diabetes and atherosclerosis. High-density lipoprotein (HDL) mediates reverse cholesterol transport, which also protects against atherosclerosis. In this process, the human homolog of the B class type I scavenger receptor (SR-BI/CLA-1) facilitates the cellular uptake of cholesterol from HDL. The level of circulating APN is positively correlated with the serum level of HDL-cholesterol. In this study, we investigated whether HDL stimulates the gene expression of APN through the Ca2+/calmodulin (CaM)-dependent protein kinase IV (CaMKIV) cascade. APN expression was examined using real-time PCR and western blot analysis in 3T3-L1 cells incubated with HDL. CaMKIV activity was assessed by the detection of activation loop phosphorylation (at Thr196 residue), and the effect of the constitutively active form, CaMKIVc, on APN promoter activity was investigated. Our results showed that HDL stimulated APN gene expression via hSR-BI/CLA-1. Furthermore, we explored the signaling pathways by which HDL stimulated APN expression in 3T3-L1 cells. The stimulation of APN gene expression by HDL appears to be mediated by CaMKK, as STO-609, a specific inhibitor of CaMKK2, prevents this effect. We revealed that CaMKIVc increased APN gene transcriptional activity, and the CaMKIV-dominant negative mutant blocked the effect of HDL on APN promoter activity. Finally, knockdown of hSR-BI/CLA-1 also canceled the effect of HDL on APN gene expression. These results suggest that HDL has an important role to improve the function of adipocytes by activating hSR-BI/CLA-1, and CaMKK/CaMKIV pathway is conceivable as one of the signaling pathways of this activation mechanism.

Oxidized LDL Downregulates ABCA1 Expression via MEK/ERK/LXR Pathway in INS-1 Cells

Impaired insulin secretion is one of the main causes of type 2 diabetes. Cholesterol accumulation-induced lipotoxicity contributes to impaired insulin secretion in pancreatic beta cells. However, the detailed mechanism in this process remains unclear. In this study, we proved that oxidized low-density lipoprotein (OxLDL) reduced insulin content, decreased PDX-1 expression, and impaired glucose-stimulated insulin secretion (GSIS) in INS-1 cells, which were rescued by addition of high-density lipoprotein (HDL). OxLDL receptors and cholesterol content were increased by OxLDL. Consistently, OxLDL suppressed cholesterol transporter ABCA1 expression and transcription in a dose-dependent and time-dependent manner. Inhibition of MEK by its specific inhibitor, PD98059, altered the effect of OxLDL on ABCA1 transcription and activation of ERK. Next, chromatin immunoprecipitation assay demonstrated that liver X receptor (LXR) could directly bind to ABCA1 promoter and this binding was inhibited by OxLDL. Furthermore, OxLDL decreased the nuclear LXR expression, which was prevented by HDL. LXR-enhanced ABCA1 transcription was suppressed by OxLDL, and the effect was cancelled by mutation of the LXR-binding sites. In summary, our study shows that OxLDL down-regulates ABCA1 expression by MEK/ERK/LXR pathway, leading to cholesterol accumulation in INS-1 cells, which may result in impaired insulin synthesis and GSIS.

Treatment with 2-methoxyestradiol increases endothelial nitric oxide synthase activity via scavenger receptor class BI in human umbilical vein endothelial cells

Concentrations of 2-methoxyestradiol (2ME2), a principal metabolite of estradiol, are significantly lower in women with severe preeclampsia. Nitric oxide (NO) released by endothelial nitric oxide synthase (eNOS) plays an important role in regulating cardiovascular homeostasis. Importantly, high-density lipoprotein (HDL) stimulates eNOS activity via endothelial human scavenger receptor class B type I (hSR-BI/CLA-1). Here, we aimed to determine the effect of 2ME2 on hSR-BI/CLA-1 expression in human umbilical vein endothelial cells (HUVECs). hSR-BI/CLA-1 expression was measured by real-time PCR, western blotting and reporter gene assays; eNOS activity was assessed by the measurement of eNOS phosphorylation. Both the mRNA and protein concentrations of hSR-BI/CLA-1 were significantly increased by 2ME2 in HUVECs. 2ME2 also dose-dependently increased the transcriptional activity of the hSR-BI/CLA-1 promoter. The effect of 2ME2 treatment on the promoter activity of hSR-BI/CLA-1 was abrogated by treatment with LY294002, a specific inhibitor of phosphatidylinositol 3-kinase, as was the increase in HDL-induced eNOS activation. Notably, constitutively active Akt increased the activity of the hSR-BI/CLA-1 promoter, whereas dominant-negative Akt abolished the effect of 2ME2 treatment on hSR-BI/CLA-1 promoter activity. The nuclear Sp1 protein concentration was significantly increased by exposure to 2ME2 and Sp1 overexpression increased the promoter activity of the hSR-BI/CLA gene. Furthermore, knockdown of Sp1 inhibited the effect of 2ME2 treatment on hSR-BI/CLA-1 protein expression. These results indicate that 2ME2 treatment increases HDL-dependent eNOS phosphorylation by upregulating endothelial hSR-BI/CLA-1 expression, suggesting that 2ME2 has a potential therapeutic value in the treatment of preeclampsia.

Candidate plasticity gene 16 and jun dimerization protein 2 are involved in the suppression of insulin gene expression in rat pancreatic INS-1 β-cells

Chronic hyperglycemia causes pancreatic β-cell dysfunction, impaired insulin secretion and the suppression of insulin gene expression. This phenomenon is referred to as glucotoxicity, and is a critical component of the pathogenesis of type 2 diabetes. We previously reported that the expression of candidate plasticity gene 16 (CPG16) was higher in rat pancreatic INS-1 β-cells under glucotoxic conditions and CPG16 suppressed insulin promoter activity. However, the molecular mechanisms of the CPG16-mediated suppression of insulin gene expression are unclear. In this study, we found that CPG16 directly bound and phosphorylated jun dimerization protein 2 (JDP2), an AP-1 family transcription factor. CPG16 co-localized with JDP2 in the nucleus of INS-1 cells. JDP2 bound to the G1 element of the insulin promoter and up-regulated promoter activity. Finally, CPG16 suppressed the up-regulation of insulin promoter activity by JDP2 in a kinase activity-dependent manner. These results suggest that CPG16 suppresses insulin promoter activity by phosphorylating JDP2.

Successful Therapy Using Pasireotide Long-acting Release for Cushing's Disease Merged with Biochemical Acromegaly

It is quite rare that Cushing's disease shows acromegaly, and no pharmacotherapy has yet been discussed. A 21-year-old woman was diagnosed with Cushing's disease and underwent trans-sphenoidal surgery. Five years later, she was diagnosed with recurrent Cushing's disease and biochemical acromegaly because of elevated levels of serum growth hormone (GH), plasma insulin-like growth factor-1, plasma adrenocorticotropic hormone (ACTH), and the 24-hour urinary excretion of free cortisol. After treatment initiation with pasireotide-long-acting release (LAR), both the ACTH and GH declined. Our case is the first to show the efficacy of pasireotide-LAR in controlling both Cushing's disease and acromegaly.

Autophagy contributes to angiotensin II induced dysfunction of HUVECs

BACKGROUND

Signal transduction of Angiotensin II (Ang II) induced autophagy and its role in Ang II-induced dysfunction of HUVECs are still unclear.

METHODS

HUVECs are stimulated with different doses of Ang II (10-9-10-5 mol/L) for different time (6-48 hours). Autophagy-related protein markers: LC3, Beclin-1 and SQSTM1/p62 are measured by western blot.

RESULTS

Incubation with Ang II increases autophagic flux (Beclin-1, autophagosomes formation, and degradation of SQSTM1/p62, LC3-I). Increased autophagic levels are inhibited by pretreatment with Ang II type 1 receptor (AT1) blocker (Candesartan), NADPH Oxidase inhibitor (apocycin), mitochondrial K_ATP channels inhibitor (5-hydroxydecanoate, 5HD). 3-Methyladenine (inhibitors of autophagy) and rapamycin (activator of autophagy) respectively inhibits or activates Ang II-induced autophagy levels. Ang II decreases phosphorylation of endothelial nitric oxide synthase (eNOS) and NO production in HUVECs. L-NAME (NOS inhibitor) totally mimics the actions of Ang II on eNOS, NO production and autophagy levels. Rapamycin further decreases NO production combined with Ang II. Silence Atg5 completely reverses Ang II-activated autophagy levels.

CONCLUSIONS

Our results demonstrate that Ang II stimulation increases autophagy levels via AT1 receptor, NADPH oxidase, mitochondrial K_ATP channel, eNOS, Atg5 signal pathway in HUVECs, and activation of autophagy contributes to Ang II induced dysfunction of HUVECs.

Effects of bilirubin configurational photoisomers on the measurement of direct bilirubin by the vanadate oxidation method

BACKGROUND

Direct-reacting bilirubin concentrations measured using vanadate chemical oxidation method do not exactly match the conjugated bilirubin concentration. One of the causes is the effect of bilirubin photoisomers. However, the quantitative evaluation of the effects of these photoisomers has not been sufficiently conducted. In particular, the influence of bilirubin configurational isomers on direct bilirubin is the most critical factor.

METHODS

Sixteen residual serum samples were used. For quantitative analysis based on the change in direct bilirubin and bilirubin configurational isomer, samples were irradiated via blue light-emitting diodes to suppress the production of bilirubin structural isomers. Total bilirubin and direct bilirubin concentrations were measured using the vanadate chemical oxidation method. Concentrations of 4Z,15Z-bilirubin IXα and its photoisomers were measured using high-performance liquid chromatography. The sum of 4Z,15E-bilirubin IXα and 4E,15Z-bilirubin IXα was notated as bilirubin configurational isomer, and the differences between the measured values of the irradiated and non-irradiated samples were calculated and notated as ΔDB and ΔBCI.

RESULTS

In non-irradiated and irradiated samples, total bilirubin and direct bilirubin concentrations were 10.73 mg/dL with significant a decrease to 10.60 mg/dL and 0.69 mg/dL with a significant increase to 0.78 mg/dL, while bilirubin configurational isomer values were 1.00 mg/dL and 1.52 mg/dL, respectively. The linear regression equation revealed a significant positive correlation of Y = 0.187X-0.006 between ΔDB (Y) and ΔBCI (X).

CONCLUSION

Applying the vanadate chemical oxidation method affected approximately 19% of the bilirubin configurational isomer concentration for direct bilirubin. Extreme caution is necessary when interpreting the measured values of samples indicative of unconjugated hyperbilirubinaemia.

AGEs inhibit scavenger receptor class B type I gene expression via Smad1 in HUVECs

Vascular complications are the main cause of morbidity and mortality in diabetic patients, and advanced glycation end products (AGEs) play a critical role in promoting diabetic vascular dysfunction. The human homolog of scavenger receptor class B type I (SR-BI), CD36, and LIMPII analog-1 (hSR-BI/CLA-1) facilitates the cellular uptake of cholesterol from HDL. In endothelial cells, HDL activates endothelial nitric oxide synthase (eNOS) via hSR-BI/CLA-1. In this study, we elucidated the effects of AGEs on hSR-BI/CLA-1 expression in human umbilical vein endothelial cells (HUVECs). HSR-BI/CLA-1 expression was examined by real-time PCR, western blot analysis, and reporter gene assay in HUVECs incubated with AGEs. eNOS activity was assessed by detecting the phosphorylation (Ser 1179) of eNOS. Our results showed that AGEs decreased the endogenous expression of hSR-BI/CLA-1. AGEs also inhibited the activity of the hSR-BI/CLA-1 promoter and its mRNA expression via receptor RAGE. We identified the binding site for Smad1 on the hSR-BI/CLA-1 promoter: Smad1 bound to its promoter. AGE treatment stimulated the transcriptional activity of Smad1, and mutation of the Smad1 binding site inhibited the effect of AGEs on the hSR-BI/CLA-1 promoter. HDL-treatment enhanced the phosphorylation of eNOS at Ser 1179, but pretreatment with AGEs inhibited the phosphorylation of eNOS Ser 1179. These results suggested that AGEs downregulate the expression of the endothelial hSR-BI/CLA-1 via the Smad1 pathway, which may be a therapeutic target for diabetic endothelial dysfunction.

Ectopic Cortisol-producing Adrenocortical Adenoma Detected by 131I-6β-iodomethyl-norcholesterol Scintigraphy

A 50-year-old man was referred to our department for overt Cushing's syndrome (CS). His plasma cortisol concentrations were 314 μg/L, and his urinary cortisol concentrations were 431 μg/day. The plasma adrenocorticotropic hormone (ACTH) concentration was below the detectable limit. Computed tomography revealed atrophy of both adrenal glands and the presence of a left pararenal tumor. 131I-6β-iodomethyl-norcholesterol scintigraphy showed an intense uptake by the left pararenal tumor. These findings suggested that the left pararenal tumor was ectopic cortisol-producing adrenocortical adenoma. This case serves as a reminder that 131I-6β-iodomethyl-norcholesterol scintigraphy is an effective method for diagnosing ACTH-independent CS in which no adrenal tumor has been found.

Role of ATP-binding cassette transporter A1 in suppressing lipid accumulation by glucagon-like peptide-1 agonist in hepatocytes

Objective

Adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) influences hepatic cholesterol transportation. Accumulation of hepatic cholesterol leads to fatty liver disease, which is improved by glucagon-like peptide 1 (GLP-1) in diabetes. Therefore, we analyzed the molecular mechanism in the regulation of hepatic ABCA1 by GLP-1 analogue exendin-4.

Methods

Hepatic ABCA1 expression and transcription were checked by western blotting, real-time polymerase chain reaction (PCR), and luciferase assay in HepG2 cells. Chromatin immunoprecipitation (ChIP) and site-directed mutagenesis were employed to determine transcriptional regulation of the ABCA1 gene. Prolactin regulatory element-binding (PREB)-transgenic mice were generated to access the effect of exendin-4 on improving lipid accumulation caused by a high-fat diet (HFD).

Results

Exendin-4 stimulated hepatic ABCA1 expression and transcription via the Ca²⁺/calmodulin (CaM)-dependent protein kinase kinase/CaM-dependent protein kinase IV (CaMKK/CaMKIV) pathway, whereas GLP-1 receptor antagonist exendin9-39 cancelled this effect. Therefore, exendin-4 decreased hepatic lipid content. ChIP showed that PREB could directly bind to the ABCA1 promoter, which was enhanced by exendin-4. Moreover, PREB stimulated ABCA1 promoter activity, and mutation of PREB-binding site in ABCA1 promoter cancelled exendin-4-enhanced ABCA1 promoter activity. Silencing of PREB attenuated the effect of exendin-4 and induced hepatic cholesterol accumulation. Blockade of CaMKK by STO-609 or siRNA cancelled the upregulation of ABCA1 and PREB induced by exendin-4. In vivo, exendin-4 or overexpression of PREB increased hepatic ABCA1 expression and decreased hepatic lipid accumulation and high plasma cholesterol caused by a HFD.

Conclusions

Our data shows that exendin-4 stimulates hepatic ABCA1 expression and decreases lipid accumulation by the CaMKK/CaMKIV/PREB pathway, suggesting that ABCA1 and PREB might be the therapeutic targets in fatty liver disease.

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The GLP-1R agonist exendin-4 suppressed lipid accumulation by upregulating ABCA1 expression in hepatocytes.

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Exendin-4 regulated the expression and transcription of hepatic ABCA1 via the CaMKK/CaMKIV/PREB pathway.

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Overexpression of PREB or exendin-4 protected mouse liver from fatty liver by upregulation of ABCA1.

Diagnostic Value of Flow Cytometry Standardized Using the European LeukemiaNet for Myelodysplastic Syndrome

BACKGROUND

Myelodysplastic syndromes (MDS) and idiopathic cytopenia of undetermined significance (ICUS) are heterogeneous hematological disorders characterized by hematopoietic dysplasia and/or chromosomal aberrancy.

OBJECTIVES

This study aimed to evaluate the diagnostic value of flow cytometry standardized using the European LeukemiaNet (ELN) for MDS and ICUS by analyzing samples obtained from patients with cytopenia based on morphological examination, cytogenetic analysis, and flow cytometry.

METHODS

We retrospectively analyzed bone marrow samples aspirated from 253 consecutive patients (median age: 66 years [range: 1-92]) to identify the cause of cytopenia.

RESULTS

Sixty patients presented with MDS, and 16 with ICUS. MDS subtypes were distributed as follows: MDS with single-lineage dysplasia (n = 10); MDS with multi-lineage dysplasia (n = 10); MDS with ringed sideroblasts (n = 4); MDS with excess blasts-1 (n = 9); MDS with excess blasts-2 (n = 13), MDS unclassified (n = 5); 5q-syndrome (n = 6); and MDS/myeloproliferative neoplasms (n = 3). Four representative ELN indexes were used. Two or more ELN MDS indexes were in the abnormal range in 35 MDS cases (58.3%) and 4 ICUS cases (25.0%).

CONCLUSIONS

Morphological examination remains the standard for MDS diagnosis. Considering the low incidence of genetically proven ICUS (20.2-27.5%), the low sensitivity of ELN MDS indexes for ICUS is considered a valuable alternative.

Co-existing of Neuromyelitis Optica and Fulminant Type 1 Diabetes

The patient was a 71-year-old woman with aquaporin-4-antibody positive neuromyelitis optica (NMO), with no history of diabetes. On admission, although she showed an extremely elevated plasma glucose level (1,080 mg/dL), her hemoglobin A1c level was low (7.1%), which indicated the rapid progression of diabetes. She also showed ketoacidosis and had a human leukocyte antigen haplotype, DRB1*09:01-DQB1*03:03 associated with Fulminant type 1 diabetes (FT1D). Based on these results, the patient was diagnosed with FT1D. We herein describe the first reported case of a patient with FT1D with NMO, which raises the possibility that T-cell-mediated autoimmunity is involved in the pathogenesis of both FT1D and NMO.

Method for ABO Blood Group Testing Using a General-Purpose Automated Biochemical Analyzer

BACKGROUND

We investigated a high-throughput and high-precision forward ABO blood typing screening method that utilizes a general-purpose biochemical analyzer to perform direct red blood cell sampling.

METHODS

The blood group antisera used were Ortho® BioClone® Anti-A Serum and Ortho® BioClone® Anti-B Se-rum. AFFIRMAGEN® Reagent Red Blood Cells (Ortho Clinical Diagnostics) were used for AB standard red blood cells. The general-purpose biochemical analyzer employed was the TBATM-120FR HbA1c measurement unit (Canon Medical Systems).

RESULTS

ABO blood group of patient samples was determined based on values relative to amount of change in the AFFIRMAGEN® response. Repeatability was CV5% or lower, and testing of 1,112 patient samples showed 100% agreement between the results obtained using the proposed method and those obtained using the tube test method.

CONCLUSIONS

The proposed method allows ABO blood typing to be performed simply, quickly, and with a high degree of precision.

Bilateral Adrenocortical Adenomas along with Virilization and Cushing's Syndrome

We herein present the case of a 27-year-old woman with clinical and biochemical features of virilism. Imaging studies revealed the presence of a bilateral adrenal tumor. Although the secretion of androgens was remarkable, the autonomous production of cortisol was also evident because of a loss of circadian rhythm and the absence of cortisol suppression by dexamethasone. The surgical excision of both adrenal tumors was performed, and the histological examination showed no malignancy. We also report the successful pregnancy and delivery of the patient who showed evolving adrenocortical insufficiency along with virilization and Cushing's syndrome and who continued to receive glucocorticoid replacement therapy during pregnancy.

Urinary adiponectin as a new diagnostic index for chronic kidney disease due to diabetic nephropathy

OBJECTIVE

The chronic kidney disease (CKD) is widely diagnosed on the basis of albuminuria and the glomerular filtration rate. A more precise diagnosis of CKD, however, requires the assessment of other factors. Urinary adiponectin recently attracted attention for CKD assessment, but evaluation is difficult due to the very low concentration of urinary adiponectin in normal subjects.

RESEARCH DESIGN AND METHODS

We developed an ultrasensitive ELISA coupled with thionicotinamide-adenine dinucleotide cycling to detect trace amounts of proteins, which allows us to measure urinary adiponectin at the subattomole level. We measured urinary adiponectin levels in 59 patients with diabetes mellitus (DM) and 24 subjects without DM (normal) to test our hypothesis that urinary adiponectin levels increase with progression of CKD due to DM.

RESULTS

The urinary adiponectin levels were 14.88±3.16 (ng/mg creatinine, mean±SEM) for patients with DM, and 3.06±0.33 (ng/mg creatinine) for normal subjects. The threshold between them was 4.0 ng/mg creatinine. The urinary adiponectin levels increased with an increase in the CKD risk. Furthermore, urinary adiponectin mainly formed a medium-molecular weight multimer (a hexamer) in patients with DM, whereas it formed only a low-molecular weight multimer (a trimer) in normal subjects. That is, the increase in urinary adiponectin in patients with DM led to the emergence of a medium-molecular weight form in urine.

CONCLUSIONS

Our new assay showed that urinary adiponectin could be a new diagnostic index for CKD. This assay is a non-invasive test using only urine, thus reducing the patient burden.

IGF1 suppresses cholesterol accumulation in the liver of growth hormone-deficient mice via the activation of ABCA1

Recently, several clinical studies have suggested that adult growth hormone (GH) deficiency that also has low concentration of IGF1 is associated with an increased prevalence of fatty liver (FL). ATP-binding cassette transporter A1 (ABCA1) is a pivotal regulator of lipid efflux from cells to apolipoproteins and plays an important role on formation of FL. In this study, we determined the effects of IGF1 on ABCA1 expression in GH-deficient mice to clarify its effects on FL. Western blotting, real-time PCR, and a luciferase assay were employed to examine the effect of IGF1. The binding of FoxO1 to the ABCA1 promoter was assessed by chromatin immunoprecipitation (ChIP) assay. Cholesterol accumulation was analyzed by Oil Red O stain and cholesterol content measurement. We confirmed that IGF1 upregulated the ABCA1 expression. The activity of a reporter construct containing the ABCA1 promoter was induced by IGF1, and this effect was blocked by LY294002, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K). Constitutively active Akt stimulated the ABCA1 promoter activity, and a dominant-negative mutant of Akt or mutagenesis of the FoxO1 response element abolished the effect of IGF1. A ChIP assay indicated that FoxO1 mediated IGF1 transcriptional activity by directly binding to the ABCA1 promoter region. For in vivo experiments, we used an inhibitor for the GH receptor (Pegvisomant) to reduce the IGF1 level. A high-fat diet induced FL in mice (C57BL/6J) given Pegvisomant treatment. IGF1 treatment stimulated ABCA1 expression to improve cholesterol accumulation in these mice. These results show that the PI3K/Akt/FoxO1 pathway contributes to the regulation of ABCA1 expression in response to IGF1 stimulation that suppressed FL in GH-deficient mice.

Effect of TNF-α on the expression of ABCA1 in pancreatic β-cells

ATP-binding cassette transporter A1 (ABCA1), a 254-kD membrane protein, is a key regulator of lipid efflux from cells to apolipoproteins. ABCA1 in pancreatic β-cells influences insulin secretion and cholesterol homeostasis. Tumor necrosis factor (TNF)-α is a pleiotropic cytokine that elicits a wide spectrum of physiological events, including cell proliferation, differentiation, and apoptosis, and is also known to decrease glucose-dependent insulin secretion in pancreatic islets. In the present study, we examined the role of TNF-α on ABCA1 expression in rat pancreatic islets and INS-1 cells. ABCA1 protein levels decreased in response to rising concentrations of TNF-α in pancreatic islets. Real-time polymerase chain reaction analysis showed a significant decrease in ABCA1 mRNA expression. In parallel with its effect on endogenous ABCA1 mRNA levels, TNF-α suppressed the activity of a reporter construct containing the ABCA1 promoter. This effect was abrogated by BIRB796, but not by SB203580 or PD98095. The constitutively active form of p38 mitogen-activated protein kinase (MAPK) γ suppressed ABCA1 promoter activity but not p38-MAPK (α, β), while a dominant-negative mutant of p38-MAPK γ blocked the effect of TNF-α on ABCA1 promoter activity. BIRB796 inhibited the increased cholesterol ester content induced by TNF-α. However, BIRB796 had no effect on the decreased insulin content nor ABCA1 suppression caused by TNF-α in INS-1 cells. In summary, TNF-α suppressed the expression of endogenous ABCA1 in pancreatic islets and INS-1 cells. These findings raise the possibility that TNF-α may affect insulin secretion by controlling ABCA1 expression.

Selective peroxisome proliferator-activated receptor-α modulator K-877 regulates the expression of ATP-binding cassette transporter A1 in pancreatic beta cells

ATP-binding cassette transporter A1 (ABCA1) protein is a pivotal regulator of cholesterol and phospholipid efflux from cells to high-density lipoprotein (HDL) particles. Pancreatic ABCA1 functions in beta cell cholesterol homeostasis and affects insulin secretion. We investigated the effect of pemafibrate (K-877), a novel selective PPARα modulator (SPPARMα), on pancreatic ABCA1 expression. In vivo experiment, mice were divided into four treatment groups, namely, normal food plus placebo, high fat diet (HFD) plus placebo, normal food plus K-877 (0.3 mg/kg/day), or HFD plus K-877 (0.3 mg/kg/day), and treated for eight weeks. The results in vitro experiment indicate that K-877 treatment increased levels of ABCA1 mRNA, as well as protein, subsequently reduced the cellular cholesterol content in INS-1 cells. PPARα specific antagonist GW6471 attenuate K-877 induced ABCA1 expression in INS-1 cells. ABCA1 promoter activity increased with K-877 treatment at concentration 1 μM and 10 μM. Glucose-stimulated insulin secretion was ameliorated by K-877 treatment in INS-1 cells and isolated mouse islets. Although the expression of ABCA1 was reduced in mice with HFD treatment, both ABCA1 protein and mRNA levels were increased in mice with K-877 treatment. K-877 treatment improved glucose intolerance induced by HFD in mice. These findings raise the possibility that K-877 may affect insulin secretion by controlling ABCA1 expression in pancreatic beta cells.

Angiotensin II induces cholesterol accumulation and impairs insulin secretion by regulating ABCA1 in beta cells

In pancreatic β cells, ABCA1, a 254 kDa membrane protein, affects cholesterol homeostasis and insulin secretion. Angiotensin II, as the main effector of the renin-angiotensin system, decreases glucose-stimulated insulin secretion (GSIS). We examined the effect of angiotensin II on ABCA1 expression in primary pancreatic islets and INS-1 cells. Angiotensin II decreased ABCA1 protein and mRNA; angiotensin II type 1 receptor (AT1R) blockade rescued this ABCA1 repression. In parallel, angiotensin II suppressed the promoter activity of ABCA1, an effect that was abrogated by PD98095, a specific inhibitor of MAPK kinase (MEK). LXR enhanced ABCA1 promoter activity, and angiotensin II decreased the nuclear abundance of LXR protein. On a chromatin immunoprecipitation assay, LXR mediated the transcription of ABCA1 by directly binding to its promoter. Mutation of the LXR binding site on the ABCA1 promoter cancelled the effect of angiotensin II. Furthermore, angiotensin II induced cholesterol accumulation and impaired GSIS; inhibition of AT1R or MEK pathway reversed these effects. In summary, our study showed that angiotensin II suppressed ABCA1 expression in pancreatic islets and INS-1 cells, indicating that angiotensin II may influence GSIS by regulating ABCA1 expression. Additional research may address therapeutic needs in diseases such as diabetes mellitus.

Combination therapy of ipilimumab and nivolumab induced thyroid storm in a patient with Hashimoto's disease and diabetes mellitus: a case report

BACKGROUND

Recently, immune checkpoint inhibitors have widely been used for the management of advanced melanoma. However, high-grade immune-related adverse events can occur, particularly with combination immunotherapy. We report a case of a patient with melanoma who developed thyroid storm following treatment with ipilimumab and nivolumab.

CASE PRESENTATION

An 85-year-old Japanese man with a history of malignant melanoma presented to our department with severe thyrotoxicosis and poor blood glucose control. He was already being treated for Hashimoto's disease and type 2 diabetes mellitus before the treatment for the melanoma. During admission, laboratory investigations revealed the following thyroid functions: thyroid-stimulating hormone below sensitivity, free triiodothyronine 31.7 pg/ml, and thyroglobulin 48,000 IU/ml. Thyroid-stimulating hormone receptor antibody was negative, and a ^99mTc-labeled thyroid scan revealed a markedly decreased uptake. He was treated with beta-blocker, orally administered potassium iodine, a relatively low dose of prednisolone, and insulin injection therapy to control his blood glucose, resulting in an improvement in thyroid function and his symptoms.

CONCLUSION

It might be important to be aware of the possibility of thyroid storm induced by immune checkpoint inhibitors.

Human microRNAs preferentially target genes with intermediate levels of expression and its formation by mammalian evolution

MicroRNAs (miRNAs) are short, endogenous RNAs that post-transcriptionally repress mRNAs. Over the course of evolution, many new miRNAs are known to have emerged and added to the existing miRNA repertoires of drosophilids and vertebrates. Despite the large number of miRNAs in existence, the complementary pairing of only ~7 bases between miRNAs and mRNAs is sufficient to induce repression. Thus, miRNA targeting is so widespread that genes coexpressed with a miRNA have evolved to avoid sites that are targeted by the miRNA. Besides this avoidance, little is known about the preferential modes of miRNA targeting. Therefore, to elucidate miRNA targeting preference and avoidance, we evaluated the bias of the number of miRNA targeting occurrences in relation to expression intensities of miRNAs and their coexpressed target mRNAs by surveying transcriptome data from human organs. We found that miRNAs preferentially target genes with intermediate levels of expression, while avoiding highly expressed ones, and that older miRNAs have greater targeting specificity, suggesting that specificity increases during the course of evolution.

Thyroid stimulating hormone stimulates the expression of glucose transporter 2 via its receptor in pancreatic β cell line, INS-1 cells

Thyroid stimulating hormone (TSH) stimulates the secretion of thyroid hormones by binding the TSH receptor (TSHR). TSHR is well-known to be expressed in thyroid tissue, excepting it, TSHR has also been expressed in many other tissues. In this study, we have examined the expression of TSHR in rat pancreatic islets and evaluated the role of TSH in regulating pancreas-specific gene expression. TSHR was confirmed to be expressed in rodent pancreatic islets and its cell line, INS-1 cells. TSH directly affected the glucose uptake in INS cells by up-regulating the expression of GLUT2, and furthermore this process was blocked by SB203580, the specific inhibitor of the p38 MAPK signaling pathway. Similarly, TSH stimulated GLUT2 promoter activity, while both a dominant-negative p38MAPK α isoform (p38MAPK α-DN) and the specific inhibitor for p38MAPK α abolished the stimulatory effect of TSH on GLUT2 promoter activity. Finally, INS-1 cells treated with TSH showed increased protein level of glucokinase and enhanced glucose-stimulated insulin secretion. Together, these results confirm that TSHR is expressed in INS-1 cells and rat pancreatic islets, and suggest that activation of the p38MAPK α might be required for TSH-induced GLUT2 gene transcription in pancreatic β cells.

Can radiological technologists serve as primary screeners of low-dose computed tomography for the diagnosis of lung cancer?

BACKGROUND

The Accreditation Council for Lung Cancer CT Screening of Japan established guidelines for the certification of Radiological Technologists in 2009.

OBJECTIVE

To analyze the trends in examination pass rates of the Radiological Technologists and discuss the reasons.

METHODS

The cohort comprised 1593 Radiological Technologists (as examinees) based on 10-year of data (with a total of 17 examination runs). First, the examinees' written test results were analyzed. Second, an abnormal finding detection test was conducted using >100 client PCs connected to a dedicated server containing low-dose lung cancer CT screening images of 60 cases. The passing scores were correct answer rate >60% and sensitivity (TP) of >90%, respectively.

RESULTS

Overall, 1243 examinees passed with an overall rate of 78%. The average pass rate for the written test was 91%, whereas that for the abnormal findings detection test was 85%. There was a moderate correlation between the test pass rate and average years of clinical experience of the examinees for the abnormal findings detection test (R = 0.558), whereas no such correlation existed for the written test (R = 0.105).

CONCLUSIONS

In order for accredited Radiological Technologists to serve as primary screeners of low-dose computed tomography, it is important to revise the educational system according to current standard practices.

Effects of bilirubin photoisomers on the measurement of direct bilirubin by the bilirubin oxidase method

Background

We occasionally encounter increases in direct bilirubin value on reanalysis of the surplus serum collected in the past from a neonate with indirect hyperbilirubinemia. But the details of this phenomenon are unclear. We evaluated the change of direct bilirubin and the relation of bilirubin photoisomer of the serum exposed to room light.

Methods

Surplus serum samples from neonates with indirect hyperbilirubinemia were exposed to room light for 24 h. The bilirubin fraction assay of samples was performed by the bilirubin oxidase method (Nescauto and Aqua-auto Kainos reagent) and high-performance liquid chromatography.

Results

Direct bilirubin increased significantly from 0.61 to 2.36 mg/dL. The respective ratios of bilirubin photoisomers before and after exposure were as follows: cyclobilirubin (0.007 to 0.29) and (EZ)-bilirubin (0.018 to 0.041) increased significantly, (ZZ)-bilirubin decreased 0.84 to 0.55 significantly. The difference of the cyclobilirubin concentration was most closely associated with those of the direct bilirubin concentration.

Conclusion

Direct bilirubin value was increased after exposure to the room light, and increase in direct bilirubin was significantly correlated by cyclobilirubin increase in the serum samples from neonates with indirect hyperbilirubinemia.

Effects of sodium-glucose cotransporter 2 inhibitors on urinary excretion of intact and total angiotensinogen in patients with type 2 diabetes

We conducted a descriptive case study to examine the effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors on urinary angiotensinogen excretion, which represents the function of the intrarenal renin–angiotensin system, in patients with type 2 diabetes. An SGLT2 inhibitor (canagliflozin 100 mg/day, ipragliflozin 25 mg/day, dapagliflozin 5 mg/day, luseogliflozin 2.5 mg/day or tofogliflozin 20 mg/day) was administered for 1 month (n=9). ELISA kits were used to measure both urinary intact and total angiotensinogen levels. Treatment with SGLT2 inhibitors significantly decreased hemoglobin A1c, body weight, systolic blood pressure and diastolic blood pressure (8.5±1.3 to 7.5%±1.0%, 82.5±20.2 to 80.6±20.9 kg, 143±8 to 128±14 mm Hg, 78±10 to 67±9 mm Hg, p<0.05, respectively), while urinary albumin/creatinine ratio was not significantly changed (58.6±58.9 to 29.2±60.7 mg/g, p=0.16). Both total urinary angiotensinogen/creatinine ratio and intact urinary angiotensinogen/creatinine ratio tended to decrease after administration of SGLT2 inhibitors. However, these changes were not significant (p=0.19 and p=0.08, respectively). These data suggest that treatment with SGLT2 inhibitors does not activate the intrarenal renin–angiotensin system in patients with type 2 diabetes.

Eicosapentaenoic acid down-regulates expression of the selenoprotein P gene by inhibiting SREBP-1c protein independently of the AMP-activated protein kinase pathway in H4IIEC3 hepatocytes

Selenoprotein P (encoded by SELENOP in humans, Selenop in rat), a liver-derived secretory protein, induces resistance to insulin and vascular endothelial growth factor (VEGF) in type 2 diabetes. Suppression of selenoprotein P may provide a novel therapeutic approach to treating type 2 diabetes; however, few drugs inhibiting SELENOP expression in hepatocytes have been identified. The present findings demonstrate that eicosapentaenoic acid (EPA) suppresses SELENOP expression by inactivating sterol regulatory element-binding protein-1c (SREBP-1c, encoded by Srebf1 in rat) in H4IIEC3 hepatocytes. Treatment with EPA caused concentration- and time-dependent reduction in SELENOP promoter activity. EPA activated AMP-activated protein kinase (AMPK); however, the inhibitory effect of EPA on SELENOP promoter activity was not canceled with an AMPK inhibitor compound C and dominant-negative AMPK transfection. Deletion mutant promoter assays and computational analysis of transcription factor-binding sites conserved among the species resulted in identification of a sterol regulatory element (SRE)-like site in the SELENOP promoter. A chromatin immunoprecipitation (ChIP) assay revealed that EPA decreases binding of SREBP-1c to the SELENOP promoter. Knockdown of Srebf1 resulted in a significant down-regulation of Selenop expression. Conversely, SREBP-1c overexpression inhibited the suppressive effect of EPA. These data provide a novel mechanism of action for EPA involving improvement of systemic insulin sensitivity through the regulation of selenoprotein P production independently of the AMPK pathway and suggest an additional approach to developing anti-diabetic drugs.

Prolactin regulatory element-binding protein is involved in suppression of the adiponectin gene in vivo

PURPOSE

Prolactin regulatory element-binding protein (PREB), a member of the WD-repeat protein family, has been recognized as a transcriptional factor that regulates prolactin promoter activity in the anterior pituitary of rats. PREB is expressed not only in the pituitary but also in various other tissues, including the adipose tissue. Previous studies have shown that PREB acts as a transcriptional regulator and suppresses the expression of the adiponectin gene in cultured 3T3L1 preadipocytes. The aim of this study was to further examine the potential role of PREB in adipose tissue in vivo.

METHODS

Transgenic mice that overexpressing PREB (PREB transgenic mice) were generated. Insulin resistance was evaluated in PREB transgenic mice using glucose and insulin tolerance tests. Adiponectin expression in the adipose tissue was examined by western blot analysis and quantitative polymerase chain reaction (qPCR). The expression levels of stearoyl-CoA desaturase (Scd) and adiponectin receptor 2(ADIPOR2) were quantified by qPCR.

RESULTS

Glucose and insulin tolerance tests revealed insulin resistance in PREB transgenic mice. Serum adiponectin and leptin concentrations were decreased. Adiponectin gene expression was decreased in the adipose tissue, which was confirmed by the downregulation of the adiponectin-dependent hepatic Scd gene and upregulation of the ADIPOR2 gene in the liver of PREB transgenic mice. We also found that pioglitazone, an agonist for the peroxisome proliferator-activated receptor-r, improved the insulin resistance in the PREB transgenic mice after a 10-day feeding period.

CONCLUSIONS

These results demonstrated that PREB might contribute to the regulation of adiponectin gene expression in vivo.

Recurrent convulsions, hypocalcemia, and hypoparathyroidism related to delayed diagnosis of 22q11.2 deletion syndrome in a middle-aged man

Case

A 49-year-old man had idiopathic epilepsy with recurrent convulsions and history of cleft palate, mental retardation, schizophrenia, and cataract. He had convulsions the day before and on the day of admission. Fosphenytoin was given i.v.; his convulsion stopped, but he lost consciousness 2 h later and was admitted. Glasgow Coma Scale score on arrival was 3. Cerebral computed tomography showed bilateral calcification in the basal ganglia. Laboratory tests showed decreased serum calcium and albumin and increased creatine kinase. He regained consciousness after i.v. calcium gluconate administration. Additionally, he showed decreased parathyroid hormone and 1,25(OH)₂ vitamin D. Suspecting hypoparathyroidism, i.v. calcium gluconate was changed to oral vitamin D. His medical history and physical appearance suggested 22q11.2 deletion syndrome, confirmed by chromosomal analysis.

Outcome

The patient was discharged after 29 days and remains convulsion-free.

Conclusion

Hypocalcemia due to hypoparathyroidism should be considered in the differential diagnosis of adult recurrent convulsions.

Insulin-like Growth Factor 1 Regulates the Expression of ATP-Binding Cassette Transporter A1 in Pancreatic Beta Cells

ATP-binding cassette transporter A1 (ABCA1) in pancreatic beta cells influences insulin secretion and cholesterol homeostasis. The present study investigates whether insulin-like growth factor 1 (IGF-1), which mediates stimulation of ABCA1 gene expression, could also interfere with the phosphatidylinositol 3-kinase (PI3-K) cascade.ABCA1 expression was examined by real-time polymerase chain reaction (PCR), Western blot analysis, and a reporter gene assay in rat insulin-secreting INS-1 cells incubated with IGF-1. The binding of forkhead box O1 (FoxO1) protein to the ABCA1 promoter was assessed by a chromatin immunoprecipitation (ChIP) assay. ABCA1 protein levels increased in response to rising concentrations of IGF-1. Real-time PCR analysis showed a significant increase in ABCA1 mRNA expression. However, both effects were suppressed after silencing the IGF-1 receptor. In parallel with its effect on endogenous ABCA1 mRNA levels, IGF-1 induced the activity of a reporter construct containing the ABCA1 promoter, while it was abrogated by LY294002, a specific inhibitor of PI3-K. Constitutively active Akt stimulated activity of the ABCA1 promoter, and a dominant-negative mutant of Akt or mutagenesis of the FoxO1 response element in the ABCA1 promoter abolished the ability of IGF-1 to stimulate promoter activity. A ChIP assay showed that FoxO1 mediated its transcriptional activity by directly binding to the ABCA1 promoter region. The knockdown of FoxO1 disrupted the effect of IGF-1 on ABCA1 expression. Furthermore, IGF-1 promoted cholesterol efflux and reduced the pancreatic lipotoxicity. These results demonstrate that the PI3-K/Akt/FoxO1 pathway contributes to the regulation of ABCA1 expression in response to IGF-1 stimulation.

Roles of lipoprotein receptors in the entry of hepatitis C virus

Infection by hepatitis C virus (HCV), a plus-stranded RNA virus that can cause cirrhosis and hepatocellular carcinoma, is one of the major health problems in the world. HCV infection is considered as a multi-step complex process and correlated with abnormal metabolism of lipoprotein. In addition, virus attacks hepatocytes by the initial attaching viral envelop glycoprotein E1/E2 to receptors of lipoproteins on host cells. With the development of HCV model system, mechanisms of HCV cell entry through lipoprotein uptake and its receptor have been extensively studied in detail. Here we summarize recent knowledge about the role of lipoprotein receptors, scavenger receptor class B type I and low-density lipoprotein receptor in the entry of HCV, providing a foundation of novel targeting therapeutic tools against HCV infection.

Risk factors for early hemorrhagic complications after endovascular coiling of ruptured intracranial aneurysms

BACKGROUND AND PURPOSE

The risk factors of early hemorrhagic complications after endovascular coiling are not well-known. We identified the factors affecting early hemorrhagic complications, defined as any expansion or appearance of hemorrhage shown by head CT in the initial 48 hours after coiling.

MATERIALS AND METHODS

We retrospectively reviewed a series of 93 patients who underwent coiling for a ruptured saccular aneurysm between 2006 and 2012 at our hospital.

RESULTS

Five patients showed early hemorrhagic complications, and all involved an expansion of the existing intracerebral hematoma immediately after coiling. The associated risk factors were accompanying intracerebral hemorrhage at onset (P < .001), postoperative antiplatelet therapy (P < .001), and thromboembolic complications (P = .044). In the accompanying intracerebral hemorrhage group, the associated risk factors were postoperative antiplatelet therapy (P = .044) and earlier initiation of coiling (9.8 ± 6.5 versus 28.1 ± 24.0 hours, P = .023). Early hemorrhagic complications were significant risk factors for worse clinical outcome (modified Rankin Scale, 2.02 ± 2.21 versus 4.4 ± 2.30, P = .022). None of the 93 patients showed further hemorrhage after the initial 48 hours after coiling.

CONCLUSIONS

The accompanying intracerebral hemorrhage at onset, thromboembolic complications, postoperative antiplatelet therapy, and earlier initiation of coiling were the risk factors for early hemorrhagic complications.

17β-Estradiol regulates scavenger receptor class BI gene expression via protein kinase C in vascular endothelial cells

High-density lipoprotein (HDL) mediates reverse cholesterol transport. In this process, the human homolog of the B class, type I scavenger receptor (SR-BI), CD36, and LIMPII analogous-1 (hSR-BI/CLA-1) facilitates the cellular uptake of cholesterol from HDL. In endothelial cells, HDL activates endothelial nitric oxide synthase (eNOS) via hSR-BI/CLA-1, and 17β-estradiol (E2) modulates nitric oxide (NO) synthesis. In this study, we elucidated the effect of E2 on hSR-BI/CLA-1 expression in human umbilical vein endothelial cells (HUVECs). HSR-BI/CLA-1 expression was examined by real-time PCR, western blot analysis and reporter gene assay in HUVECs incubated with E2. eNOS activity was assessed by detection of phosphorylation (Ser 1179) of eNOS. We investigated the effect of the constitutively active form or dominant negative form of protein kinase C on hSR-BI/CLA-1 promoter activity. Our results showed that E2 increased the endogenous expression of hSR-BI/CLA-1. E2 also enhanced the activity of the hSR-BI/CLA-1 promoter and the expression of its mRNA. However, bisindolylmaleimide I, an inhibitor of protein kinase C, blocked the stimulatory effect of E2 on hSR-BI/CLA-1 promoter activity. Moreover, constitutively active PKC increased the activity of the hSR-BI/CLA-1 promoter, and a dominant-negative mutant of PKC prevented E2 from stimulating promoter activity. In cells treated with E2, HDL stimulated the phosphorylation of serine 1179 of eNOS in HUVECs. These results suggested that E2 upregulates the expression of the endothelial hSR-BI/CLA-1 via the PKC pathway, which may be a novel mechanism of the anti-atherosclerotic potential of E2 in vascular endothelial cells.

Effect of the anti-diabetic drug metformin in hepatocellular carcinoma in vitro and in vivo

Metformin is a commonly used oral anti-hyperglycemic agent of the biguanide family. Recent studies suggest that metformin may reduce cancer risk and improve prognosis. However, the antitumor mechanism of metformin in several types of cancers, including hepatocellular carcinoma (HCC), has not been elucidated. The goal of the present study was to evaluate the effects of metformin on HCC cell proliferation in vitro and in vivo, and to study microRNAs (miRNAs) associated with the antitumor effect of metformin in vitro. We used the cell lines Alex, HLE and Huh7, and normal hepatocytes to study the effects of metformin on human HCC cells. In an in vivo study, athymic nude mice bearing xenograft tumors were treated with metformin or left untreated. Tumor growth was recorded after 4 weeks, and the expression of cell cycle-related proteins was determined. Metformin inhibited the proliferation of Alex, HLE and Huh7 cells in vitro and in vivo. Metformin blocked the cell cycle in G0/G1 in vitro and in vivo. This blockade was accompanied by a strong decrease of G1 cyclins, especially cyclin D1, cyclin E and cyclin-dependent kinase 4 (Cdk4). In addition, microRNA (miRNA) expression was markedly altered by the treatment with metformin in vitro and in vivo. In addition, various miRNAs induced by metformin also may contribute to the suppression of tumor growth. Our results demonstrate that metformin inhibits the growth of HCC, possibly by inducing G1 cell cycle arrest through the alteration of microRNAs.

[Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2012]

The nationwide surveillance of antibacterial susceptibility to meropenem (MEPM) and other parenteral antibiotics against clinical isolates during 2012 in Japan was conducted. A total of 2985 strains including 955 strains of Gram-positive bacteria, 1782 strains of Gram-negative bacteria, and 248 strains of anaerobic bacteria obtained from 31 medical institutions were examined. The results were as follows; 1. MEPM was more active than the other carbapenem antibiotics tested against Gram-negative bacteria, especially against enterobacteriaceae and Haemophilus influenzae. MEPM was also active against most of the species tested in Gram-positive and anaerobic bacteria, except for multi-drug resistant strains including methicillin-resistant Staphylococcus aureus (MRSA). 2. Of all species tested, there were no species, which MIC90 of MEPM was more than 4-fold higher than those in our previous studies in 2009 or 2006. Therefore, the tendency to increase in antimicrobial resistance rates was not observed. 3. MEPM resistance against Pseudomonas aeruginosa was 17.8% (56/315 strains). Compared to our previous results, it was the lowest than that in 2006 and 2009. 4. Carbapenem-resistant Klebsiella pneumoniae, and multi-drug-resistant Acinetobacter species, which emerged in worldwide, were not observed. 5. The proportion of extended-spectrum beta-lactamase (ESBL) strains was 6.2% (59/951 strains) in enterobacteriaceae, which increased compared with that of our previous studies in 2009 or before. Whereas, the proportion of metallo-beta-lactamase strains was 1.6% (5/315 strains) in P. aeruginosa, which was stable. In conclusion, the results from this surveillance suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem for serious infections treatment at present, 17 years passed after available for commercial use in Japan.

Influence of cognitive impairment on the management of ischaemic stroke

BACKGROUND

Because of ageing of the population, it is more and more frequent to treat ischaemic stroke patients with pre-stroke cognitive impairment (PSCI). Currently, there is no specific recommendation on ischaemic stroke management in these patients, both at the acute stage and in secondary prevention. However, these patients are less likely to receive treatments proven effective in randomised controlled trials, even in the absence of contra-indication.

OBJECTIVE

To review the literature to assess efficacy and safety of validated therapies for acute ischaemic stroke and secondary prevention in PSCI patients.

RESULTS

Most randomised trials did not take into account the pre-stroke cognitive status. The few observational studies conducted at the acute stage or in secondary prevention, did not provide any information that the benefit could be either lost or replaced by harm in the presence of PSCI.

CONCLUSIONS

There is no reason not to treat ischaemic stroke patients with PSCI according to the currently available recommendations for acute management and secondary prevention. Further observational studies are needed and pre-stroke cognition should be taken into account in future stroke trials.

Effect of the anti-diabetic drug metformin in hepatocellular carcinoma in vitro and in vivo

Metformin is a commonly used oral anti-hyperglycemic agent of the biguanide family. Recent studies suggest that metformin may reduce cancer risk and improve prognosis. However, the antitumor mechanism of metformin in several types of cancers, including hepatocellular carcinoma (HCC), has not been elucidated. The goal of the present study was to evaluate the effects of metformin on HCC cell proliferation in vitro and in vivo, and to study microRNAs (miRNAs) associated with the antitumor effect of metformin in vitro. We used the cell lines Alex, HLE and Huh7, and normal hepatocytes to study the effects of metformin on human HCC cells. In an in vivo study, athymic nude mice bearing xenograft tumors were treated with metformin or left untreated. Tumor growth was recorded after 4 weeks, and the expression of cell cycle‑related proteins was determined. Metformin inhibited the proliferation of Alex, HLE and Huh7 cells in vitro and in vivo. Metformin blocked the cell cycle in G0/G1 in vitro and in vivo. This blockade was accompanied by a strong decrease of G1 cyclins, especially cyclin D1, cyclin E and cyclin-dependent kinase 4 (Cdk4). In addition, microRNA (miRNA) expression was markedly altered by the treatment with metformin in vitro and in vivo. In addition, various miRNAs induced by metformin also may contribute to the suppression of tumor growth. Our results demonstrate that metformin inhibits the growth of HCC, possibly by inducing G1 cell cycle arrest through the alteration of microRNAs.

Metformin suppresses expression of the selenoprotein P gene via an AMP-activated kinase (AMPK)/FoxO3a pathway in H4IIEC3 hepatocytes

Selenoprotein P (SeP; encoded by SEPP1 in humans) is a liver-derived secretory protein that induces insulin resistance in type 2 diabetes. Suppression of SeP might provide a novel therapeutic approach to treating type 2 diabetes, but few drugs that inhibit SEPP1 expression in hepatocytes have been identified to date. The present findings demonstrate that metformin suppresses SEPP1 expression by activating AMP-activated kinase (AMPK) and subsequently inactivating FoxO3a in H4IIEC3 hepatocytes. Treatment with metformin reduced SEPP1 promoter activity in a concentration- and time-dependent manner; this effect was cancelled by co-administration of an AMPK inhibitor. Metformin also suppressed Sepp1 gene expression in the liver of mice. Computational analysis of transcription factor binding sites conserved among the species resulted in identification of the FoxO-binding site in the metformin-response element of the SEPP1 promoter. A luciferase reporter assay showed that metformin suppresses Forkhead-response element activity, and a ChIP assay revealed that metformin decreases binding of FoxO3a, a direct target of AMPK, to the SEPP1 promoter. Transfection with siRNAs for Foxo3a, but not for Foxo1, cancelled metformin-induced luciferase activity suppression of the metformin-response element of the SEPP1 promoter. The overexpression of FoxO3a stimulated SEPP1 promoter activity and rescued the suppressive effect of metformin. Metformin did not affect FoxO3a expression, but it increased its phosphorylation and decreased its nuclear localization. These data provide a novel mechanism of action for metformin involving improvement of systemic insulin sensitivity through the regulation of SeP production and suggest an additional approach to the development of anti-diabetic drugs.