Glucagon-like Peptide-1 analogues and delipidation of coronary atheroma in statin-treated type 2 diabetic patients with coronary artery disease: The prespecified sub-analysis of the OPTIMAL randomized clinical trial.

Background and aims: Randomized clinical trials have demonstrated the ability of glucagon-like peptide-1 analogues (GLP-1RAs) to reduce atherosclerotic cardiovascular disease events in patients with type 2 diabetes (T2D). How GLP-1RAs modulate diabetic atherosclerosis remains to be determined yet. Methods: The OPTIMAL study was a prospective randomized controlled study to compare the efficacy of 48-week continuous glucose monitoring- and HbA1c-guided glycemic control on near infrared spectroscopty (NIRS)/intravascular ultrasound (IVUS)-derived plaque measures in 94 statin-treated patients with T2D (jRCT1052180152, UMIN000036721). Of these, 78 patients with evaluable serial NIRS/IVUS images were analyzed to compare plaque measures between those treated with (n = 16) and without GLP-1RAs (n = 72). Results: All patients received a statin, and on-treatment LDL-C levels were similar between the groups (66.9 ± 11.6 vs. 68.1 ± 23.2 mg/dL, p = 0.84). Patients receiving GLP-1RAs demonstrated a greater reduction of HbA1c [-1.0 (-1.4 to -0.5) vs. -0.4 (-0.6 to -0.2)%, p = 0.02] and were less likely to demonstrate a glucose level >180 mg/dL [-7.5 (-14.9 to -0.1) vs. 1.1 (-2.0 - 4.2)%, p = 0.04], accompanied by a significant decrease in remnant cholesterol levels [-3.8 (-6.3 to -1.3) vs. -0.1 (-0.8 - 1.1)mg/dL, p = 0.008]. On NIRS/IVUS imaging analysis, the change in percent atheroma volume did not differ between the groups (-0.9 ± 0.25 vs. -0.2 ± 0.2%, p = 0.23). However, GLP-1RA treated patients demonstrated a greater frequency of maxLCBI4mm regression (85.6 ± 0.1 vs. 42.0 ± 0.6%, p = 0.01). Multivariate analysis demonstrated that the GLP-1RA use was independently associated with maxLCBI4mm regression (odds ratio = 4.41, 95%CI = 1.19-16.30, p = 0.02). Conclusions: In statin-treated patients with T2D and CAD, GLP-1RAs produced favourable changes in lipidic plaque materials, consistent with its stabilization.

Effect of Luseogliflozin on Myocardial Flow Reserve in Patients with Type 2 Diabetes Mellitus (LUCENT-J Study).

INTRODUCTION: In patients with type 2 diabetes (T2D), treatment with sodium-glucose cotransporter-2 (SGLT2) inhibitors has been shown to reduce hospital admission rates for heart failure (HF). However, the multiple mechanisms hypothesized and investigated to explain the cardioprotection of SGLT2 inhibitors are not fully understood. OBJECTIVES: The effect of luseogliflozin on myocardial flow reserve (MFR) in patients with T2D (LUCENT-J) study aims to examine the effects of SGLT2 inhibitors on myocardial perfusion. METHODS: The LUCENT-J study is a prospective, single-center, randomized, two-arm, parallel-group, open-label (i.e., the radiology readers are blinded), active-controlled study. A cohort of 40 patients with T2D with no or stable (with no history of myocardial infarction and with or without previous percutaneous coronary intervention) coronary artery disease will be included. Patients will be randomized in a 1:1 ratio to luseogliflozin or control and treated for 24 weeks. The primary outcome is the change in MFR, as measured by 13N-ammonia positron emission tomography/computed tomography, from baseline to 24 weeks after treatment initiation. PLANNED OUTCOMES: The LUCENT-J study will elucidate the mechanisms of cardioprotection by SGLT2 inhibitors in patients with T2D. TRIAL REGISTRATION: Japan Registry of Clinical Trials (JRCTs051220016).

Exploring the genetic diversity of the Japanese population: Insights from a large-scale whole genome sequencing analysis.

The Japanese archipelago is a terminal location for human migration, and the contemporary Japanese people represent a unique population whose genomic diversity has been shaped by multiple migrations from Eurasia. We analyzed the genomic characteristics that define the genetic makeup of the modern Japanese population from a population genetics perspective from the genomic data of 9,287 samples obtained by high-coverage whole-genome sequencing (WGS) by the National Center Biobank Network. The dataset comprised populations from the Ryukyu Islands and other parts of the Japanese archipelago (Hondo). The Hondo population underwent two episodes of population decline during the Jomon period, corresponding to the Late Neolithic, and the Edo period, corresponding to the Early Modern era, while the Ryukyu population experienced a population decline during the shell midden period of the Late Neolithic in this region. Haplotype analysis suggested increased allele frequencies for genes related to alcohol and fatty acid metabolism, which were reported as loci that had experienced positive natural selection. Two genes related to alcohol metabolism were found to be 12,500 years out of phase with the time when they began to increase in the allele frequency; this finding indicates that the genomic diversity of Japanese people has been shaped by events closely related to agriculture and food production.

The effect of continuous glucose monitoring-guided glycemic control on progression of coronary atherosclerosis in type 2 diabetic patients with coronary artery disease: The OPTIMAL randomized clinical trial.

BACKGROUND: Continuous glucose monitoring (CGM) improves glycemic fluctuation and reduces hypoglycemic risk. Whether CGM-guided glycemic control favorably modulates coronary atherosclerosis in patients with type 2 diabetes (T2DM) remains unknown. METHODS: The OPTIMAL trial was a prospective, randomized, single-center trial in which 94 T2DM patients with CAD were randomized to CGM- or HbA1c-guided glycemic control for 48 weeks (jRCT1052180152). The primary endpoint was the nominal change in total atheroma volume (TAV) measured by serial IVUS. The secondary efficacy measure was the nominal change in maxLCBI4mm on near-infrared spectroscopy imaging. RESULTS: Among the 94 randomized patients, 82 had evaluable images at 48 weeks. Compared to HbA1c-guided glycemic control, CGM-guided control achieved a greater reduction in %coefficient of variation [-0.1 % (-1.8 to 1.6) vs. -3.3 % (-5.1 to -1.5), p = 0.01] and a greater increase in the duration with glucose between 70 and 180 mg/dL [-1.5 % (-6.0 to 2.9) vs. 6.7 % (1.9 to 11.5), p = 0.02]. TAV increased by 0.11 ± 1.9 mm3 in the HbA1c-guided group and decreased by -3.29 ± 2.00 mm3 in the CGM-guided group [difference = -3.4 mm3 (95%CI: -8.9 to 2.0 mm3), p = 0.22]. MaxLCBI4mm, increased by 90.1 ± 25.6 in the HbA1c-guided group and by 50.6 ± 25.6 in the CGM-guided group (difference = -45.6 (95%CI: -118.1 to 26.7) p = 0.21]. A post-hoc exploratory analysis showed a greater regression of maxLCBI4mm in the CGM-guided group [difference = 20.4 % (95%CI:1.3 to 39.5 %), p = 0.03]. CONCLUSIONS: CGM-guided control for 48 weeks did not slow disease progression in T2DM patients with CAD. A greater regression of lipidic plaque under CGM-guided glycemic control in the post-hoc analysis requires further investigation.

Diabetic microvascular complications predicts non-heart failure with reduced ejection fraction in type 2 diabetes.

AIMS: The relationship between diabetic microvascular complications and the incidence of two types of heart failure-heart failure with reduced ejection fraction (HFrEF) (left ventricular ejection fraction [LVEF] < 40%) and non-HFrEF (LVEF ≥ 40%)-in patients without prior heart failure has not been clarified. We herein examined the association between diabetic microvascular complications and HFrEF or non-HFrEF in patients with type 2 diabetes mellitus (T2DM) without prior heart failure. METHODS AND RESULTS: In this retrospective cohort study, we assessed the relationship between the presence of diabetic microvascular complications or severity of diabetic retinopathy (no apparent, non-proliferative and proliferative retinopathy) and nephropathy (normoalbuminuria, microalbuminuria, and macroalbuminuria) at baseline, with the primary outcome of first heart failure hospitalization classified as HFrEF or non-HFrEF in patients with type 2 diabetes mellitus without prior heart failure. Among 568 patients (69.2% males, mean age 66.2 ± 9.6 years), 70 experienced heart failure hospitalization (HFrEF: 24 and non-HFrEF: 46). Non-HFrEF hospitalization but not HFrEF hospitalization was significantly associated with the presence of diabetic microvascular complications. The incidence of non-HFrEF hospitalization was significantly higher in the proliferative retinopathy group than that in the no apparent retinopathy group (adjusted hazard ratio [HR] 2.96, 95% confidence interval [CI]: 1.09-6.83, P = 0.035) and in those with macroalbuminuria than in those with normoalbuminuria (adjusted HR 4.23, 95% CI: 2.24-7.85, P < 0.001) even after adjustment for age and sex. When non-HFrEF was classified into heart failure with mildly reduced ejection fraction (HFmrEF) (40% ≤ LVEF < 50%) and heart failure with preserved ejection fraction (HFpEF) (50% ≤ LVEF), HFmrEF and HFpEF hospitalizations were also found to be associated with the progression of retinopathy and nephropathy. CONCLUSIONS: In patients with T2DM without prior heart failure, non-HFrEF hospitalization was more closely associated with the progression of diabetic microangiopathy than HFrEF. The development of non-HFrEF may be mediated through a mechanism similar to that of microvascular complications in these patients.

Complement 3 Is a Potential Biomarker for Cerebral Amyloid Angiopathy.

BACKGROUND: Cerebral amyloid angiopathy is a cerebrovascular disease directly implicated in Alzheimer's disease pathogenesis through amyloid-ß deposition. Growing evidence has shown a pivotal role of chronic neuroinflammation both in cerebral amyloid angiopathy and Alzheimer's disease. OBJECTIVE: The aim of this study was to investigate whether circulating levels of the complement 3, a crucial component of the innate immune system, are increased in patients with cerebral amyloid angiopathy. METHODS: Serum complement 3 levels were retrospectively measured by a sandwich enzyme-linked immunosorbent assay in a single-center cohort of patients with mild cognitive impairment. The diagnosis of cerebral amyloid angiopathy was based on the modified Boston criteria. Logistic regression analysis was performed to identify the predictive factors for cerebral amyloid angiopathy. RESULTS: We analyzed 55 mild cognitive impairment patients (mean age [standard deviation]: 76.3 [6.8] years; 33 [60% ] men). Complement 3 levels were significantly increased in cerebral amyloid angiopathy patients (n = 16) compared with those without cerebral amyloid angiopathy (n = 39) (median [interquartile range]: 0.43 [0.34-0.65] versus 0.35 [0.25-0.45], respectively; p = 0.040). Univariate and multivariate logistic regression analysis revealed that increased complement 3 levels were significantly associated with cerebral amyloid angiopathy. After selection of the best predictive model using stepwise selection, complement 3 was preserved as a significant independent predictive factor for cerebral amyloid angiopathy (odds ratio per 0.1 unit/mL increase [95% confidence interval]: 1.407 [1.042-1.899]; p = 0.026). CONCLUSION: Complement activation may play a pivotal role in cerebral amyloid angiopathy. Complement 3 may be a novel diagnostic biomarker for cerebral amyloid angiopathy.

Impaired leptin responsiveness in the nucleus accumbens of leptin-overexpressing transgenic mice with dysregulated sucrose and lipid preference independent of obesity.

While hypothalamic leptin resistance can occur prior to establishment of obesity, clarification is needed as to whether the impaired response to leptin in the reward-related nuclei occurs independently of obesity. To answer this question, we attempted to dissociate the normally coexisting leptin resistance from obesity. We investigated phenotypes of leptin-overexpressing transgenic mice fed for 1 week with 60 % high-fat diet (HFD) (LepTg-HFD1W mice). After 1 week, we observed that LepTg-HFD1W mice weighed as same as wild type (WT) mice fed standard chow diet (CD) for 1 week (WT-CD1W mice). However, compared to WT-CD1W mice, LepTg-HFD1W mice exhibited attenuated leptin-induced anorexia, decreased leptin-induced c-fos immunostaining in nucleus accumbens (NAc), one of important site of reward system, decreased leptin-stimulated pSTAT3 immunostaining in hypothalamus. Furthermore, neither sucrose nor lipid preference was suppressed by leptin in LepTg-HFD1W mice. On the contrary, leptin significantly suppressed both preferences in WT mice fed HFD (WT-HFD1 W mice). These results indicate that leptin responsiveness decreases in NAc independently of obesity. Additionally, in this situation, suppressive effect of leptin on the hedonic feeding results in impaired regulation. Such findings suggest the impaired leptin responsiveness in NAc partially contributes to dysregulated hedonic feeding behavior independently of obesity.

Protocol for a Randomized, Crossover Trial to Decrease Time in Hypoglycemia by Combined Intervention of the Usage of Intermittent-Scanning Continuous Glucose Monitoring Device and the Structured Education Regarding its Usage: Effect of Intermittent-Scanning Continuous Glucose Monitoring to Glycemic Control Including Hypoglycemia and Quality of Life of Patients with Type 1 Diabetes Mellitus Study (ISCHIA Study).

OBJECTIVE: Intermittent-scanning continuous glucose monitoring (isCGM) is widely used in type 1 diabetes (T1D) patients; however, the education required to prevent hypoglycemia by using isCGM is not established. This study examines the combined effect of isCGM device usage and the education to reduce the time in hypoglycemia in comparison to conventional self-monitoring of blood glucose (SMBG). METHODS: The Effect of Intermittent-Scanning Continuous Glucose Monitoring to Glycemic Control Including Hypoglycemia and Quality of Life of Patients with Type 1 Diabetes Mellitus Study (ISCHIA Study), a randomized, crossover trial, enrolls 104 T1D patients (age, 20-74 years) with T1D. Participants are randomized to use isCGM combined with structured education (Intervention period) or SMBG (Control period) for 84 days, followed by the other for a further 84 days. During the Intervention period, participants have access to the sensor glucose levels and trend arrow of the device. During the Control period, participants conduct SMBG at least three times a day, and retrospective CGM is used to record the blinded sensor glucose levels. The primary endpoint is the decrease of time in hypoglycemia ( < 70 mg/dL) per day (hour/day) during the Intervention period compared with the Control period. The secondary endpoints include other indices of glycemic control, glycoalbumin, accuracy of isCGM, diabetes-related quality of life (QOL), adherence, and cost-effectiveness. The study protocol has received Certified Review Board (CRB) approval from National Hospital Organization Osaka National Hospital (N2018002, Feb 14, 2019). This study is carried out in accordance with the Declaration of Helsinki and the Clinical Trials Act. The findings will be published in peer-reviewed journals. CONCLUSION: The ISCHIA study will contribute to the standardization of patient education regarding the prevention of hypoglycemia by using isCGM.

An Efficient Culture Method of CD3-Positive T Cells from Human Cryopreserved Buffy Coat Specimens.

Context: In the National Cerebral and Cardiovascular Center (NCVC) Biobank, buffy coats have been collected from patients and stored with cryoprotective agents as a possible source for viable blood cells, using cost-efficient methods for storage. However, whether viable cells for in vitro studies can be recovered from these biospecimens has not been verified. Objective: To investigate whether T cells can be collected and expanded as viable cells from cryopreserved human buffy coats. Design: After thawing of cryopreserved buffy coat specimens, CD3-positive cells were isolated from the cell suspension using a leukocyte separation filter coated with an anti-CD3 antibody, and the filter-attached cells were cultured in T cell culture medium. To analyze the characteristics of these cultured cells, histocytological analyses of Giemsa staining, immunocytochemical (ICC) staining for CD3, and flow cytometry for CD3 in live cells were conducted. Results: A few days after starting cell culture, cell clusters were observed, and they gradually grew in size. Using Giemsa staining, the expanded cells were found to be ∼15 µm in diameter, having round nuclei, a high nucleus/cytoplasm ratio, and cytoplasm stained light blue, which is characteristic of lymphocytes. From ICC staining, these cells were CD3 positive, a pan-T cell marker among lymphocytes. Furthermore, CD3 immunoreactivity in live cells was detected in a flow cytometry assay, though that for CD19 was not detected, which is a marker of pan-B cells. Conclusions: These results suggest that T cells can be expanded from buffy coats cryopreserved at -180°C as an adequate method of NCVC Biobank, highlighting these biospecimens as a possible useful source for future in vitro studies.

A Prospective Longitudinal Study on the Relationship Between Glucose Fluctuation and Cognitive Function in Type 2 Diabetes: PROPOSAL Study Protocol.

INTRODUCTION: Although the risk of dementia among patients with type 2 diabetes mellitus (T2DM) is double that of those without T2DM, the mechanism remains to be elucidated and the glycemic goal to prevent progression of cognitive impairment is unclear. Results from cross-sectional studies suggest that glucose fluctuations are associated with impairment of cognitive function among T2DM patients. Therefore, the aim of the longitudinal study described here is to evaluate the relationships between glucose fluctuation indexes assessed by continuous glucose monitoring (CGM) and cognitive function among elderly patients with T2DM. METHODS: This will be a prospective, single-center, 2-year longitudinal study in which a total of 100 elderly patients with T2DM showing mild cognitive impairment (MCI) will be enrolled. Glucose fluctuations, assessed using the FreeStyle Libre Pro continuous glucose monitoring system (Abbott Laboratories), and results of cognitive tests, namely the Montreal Cognitive Assessment (MoCA) and Alzheimer's Disease Assessment Scale (ADAS), will be evaluated at baseline, 1-year visit and 2-year visit. The primary endpoint is the relationships between indexes of glucose fluctuation and change in MoCA and ADAS scores. Secondary endpoints are the relationships between the indexes of glucose fluctuation or cognitive scores and the following: indexes representing intracranial lesions obtained by magnetic resonance imaging and angiography of the head; Geriatric Depression Scale score; Apathy Scale score; carotid intima-media thickness assessed by echography; inflammatory markers; fasting glucose; glycated hemoglobin; blood pressure; and the development of cardiovascular and renal events. PLANNED OUTCOMES: The current study is scheduled for completion in June 2022. The results could lead to the elucidation of novel glycemic goals to prevent the progression of cognitive impairment and/or of relationships between glucose fluctuations and cognitive function among T2DM patients. The findings of the study will be reported in publications and conference presentations. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trial Registry (UMIN000038546).

Prevalence and Atypical Clinical Characteristics of NOTCH3 Mutations Among Patients Admitted for Acute Lacunar Infarctions.

Objectives: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary small vessel disease, with reported frequencies of 2-5/100,000 individuals. Recently, it has been reported that some patients with NOTCH3 gene mutations show atypical clinical symptoms of CADASIL. Assuming that CADASIL is underdiagnosed in some cases of lacunar infarction, this study was designed to examine the prevalence of NOTCH3 gene mutations in the patients at highest risk who were admitted for lacunar infarctions. Methods: From January 2011 to April 2018, 1,094 patients with lacunar infarctions were admitted to our hospital, of whom 31 patients without hypertension but with white matter disease (Fazekas scale 2 or 3) were selected and genetically analyzed for NOTCH3 gene mutations (Phase 1). Furthermore, 54 patients, who were 60 years or younger, were analyzed for NOTCH3 mutations (Phase 2). NOTCH3 exons 2-24, which encode the epidermal growth factor-like repeat domain of the NOTCH3 receptor, were analyzed for mutations by direct sequencing of genomic DNA. Results: Three patients presented NOTCH3 p.R75P mutations: two in the Phase 1 and one in the Phase 2 cohort. Among patients aged 60 years or younger and those without hypertension but with moderate-to-severe white matter lesions, the carrier frequency of p.R75P was 3.5% (3/85), which was significantly higher than that in the Japanese general population (4.7KJPN) (odds ratio [95% CI] = 58.2 [11.6-292.5]). All three patients with NOTCH3 mutations had family histories of stroke, and the average patient age was 51.3 years. All three patients also showed white matter lesions in the external capsule but not in the temporal pole. The CADASIL and CADASIL scale-J scores of the three patients were 6, 17, 7 (mean, 10.0) and 13, 20, 10 (mean, 14.3), respectively. Conclusion: Among patients hospitalized for lacunar infarctions, the p.R75P prevalence may be higher than previously estimated. The NOTCH3 p.R75P mutation may be underdiagnosed in patients with early-onset lacunar infarctions due to the atypical clinical and neuroimaging features of CADASIL. Early-onset, presence of family history of stroke, external capsule lesions, and absence of hypertension may help predict underlying NOTCH3 mutations despite no temporal white matter lesions.

The efficacy of glycemic control with continuous glucose monitoring on atheroma progression: rationale and design of the Observation of Coronary Atheroma Progression under Continuous Glucose Monitoring Guidance in Patients with Type 2 Diabetes Mellitus (OPTIMAL).

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) are high-risk subjects who more frequently have micro- and macrovascular diseases including coronary artery disease (CAD). Since impaired glycemic homeostasis directly influences the formation and propagation of atherosclerotic plaques, optimal management of glycemic status is required for the prevention of diabetic atherosclerosis. Continuous glucose monitoring (CGM) provides not only average glucose level but also the degree of glucose fluctuation and hypoglycemia. Given the association of glycemic variability with diabetic macrovascular diseases, CGM-based glycemic management could favorably modulate glycemic fluctuation, thereby potentially modifying atheroma burden in T2DM subjects. To test this hypothesis, the Observation of Coronary Atheroma Progression under Continuous Glucose Monitoring Guidance in Patients with Type 2 Diabetes Mellitus (OPTIMAL) study has been designed (Japan Registry of Clinical Trials: jRCT1052180152, University Hospital Medical Information Network Clinical Trial Registry UMIN000036721). METHODS: The OPTIMAL is a single-center, randomized trial to evaluate the efficacy of CGM-based glycemic control on atheroma progression in T2DM patients with CAD by using serial intravascular ultrasound (IVUS) and near-infrared spectroscopy (NIRS) imaging. A total of 90 eligible subjects will be randomized 1:1 into two groups to receive either CGM-based glycemic control or HbA1c-baded glycemic management. Coronary angiography and NIRS/IVUS imaging is repeated at the end of the assigned treatment period. RESULTS: The primary endpoint is the normalized absolute change in total atheroma volume (TAV) from baseline to 12 months. The secondary endpoints include (I) the absolute change in percent atheroma volume, (II) the percent change in lipid core burden index, (III) the change in coefficient variance measured by CGM, (IV) the change in atherogenic markers (high-density lipoprotein functionality, proprotein convertase subxilisin/kexin type 9 and fatty-acid binding proteins), and (V) the frequency of hypoglycemia. Safety will also be evaluated. CONCLUSIONS: The collaboration of CGM use with serial NIRS/IVUS imaging will enable to compare atheroma progression rate under CGM-based glycemic management and HbA1c-based approach.

CRISPR/Cas9-mediated Angptl8 knockout suppresses plasma triglyceride concentrations and adiposity in rats.

Angiopoietin-like protein (ANGPTL)8 is a liver- and adipocyte-derived protein that controls plasma triglyceride (TG) levels. Most animal studies have used mouse models. Here, we generated an Angptl8 KO rat model using a clustered regulatory interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) (CRISPR/Cas9) system to clarify the roles of ANGPTL8 in glucose and lipid metabolism. Compared with WT rats, Angptl8 KO rats had lower body weight and fat content, associated with impaired lipogenesis in adipocytes; no differences existed between the groups in food intake or rectal temperature. Plasma TG levels in both the fasted and refed states were significantly lower in KO than in WT rats, and an oral fat tolerance test showed decreased plasma TG excursion in Angptl8 KO rats. Higher levels of lipase activity in the heart and greater expression of genes related to ß-oxidation in heart and skeletal muscle were observed in Angptl8 KO rats. However, there were no significant differences between KO and WT rats in glucose metabolism or the histology of pancreatic ß-cells on both standard and high-fat diets. In conclusion, we demonstrated that Angptl8 KO in rats resulted in lower body weight and plasma TG levels without affecting glucose metabolism. ANGPTL8 might be an important therapeutic target for obesity and dyslipidemia.

Analysis of mitochondrial function in human induced pluripotent stem cells from patients with mitochondrial diabetes due to the A3243G mutation.

We previously established human induced pluripotent stem (iPS) cells in two diabetic patients from different families with the mitochondrial A3243G mutation and isolated isogenic iPS cell clones with either undetectable or high levels of the mutation in both patients. In the present study, we analyzed the mitochondrial functions of two mutation-undetectable and two mutation-high clones in each patient through four methods to assess complex I activity, mitochondrial membrane potential, mitochondrial respiration, and mitochondrial ATP production. In the first patient, complex I activity, mitochondrial respiration, and mitochondrial ATP production were decreased in the mutation-high clones compared with the mutation-undetectable clones, and mitochondrial membrane potential was decreased in a mutation-high clone compared with a mutation-undetectable clone. In the second patient, complex I activity was decreased in one mutation-high clone compared with the other clones. The other parameters showed no differences in any clones. In addition, the complex I activity and mitochondrial respiration of the mutation-undetectable clones from both patients were located in the range of those of iPS cells from healthy subjects. The present study suggests that the mitochondrial function of the mutation-undetectable iPS cell clones obtained from two patients with the A3243G mutation is comparable to the control iPS cells.

Development of ghrelin transgenic mice for elucidation of clinical implication of ghrelin.

To elucidate the clinical implication of ghrelin, we have been trying to generate variable models of transgenic (Tg) mice overexpressing ghrelin. We generated Tg mice overexpressing des-acyl ghrelin in a wide variety of tissues under the control of ß-actin promoter. While plasma des-acyl ghrelin level in the Tg mice was 44-fold greater than that of control mice, there was no differences in the plasma ghrelin level between des-acyl ghrelin Tg and the control mice. The des-acyl ghrelin Tg mice exhibited the lower body weight and the shorter body length due to modulation of GH-IGF-1 axis. We tried to generate Tg mice expressing a ghrelin analog, which possessed ghrelin-like activity (Trp3-ghrelin Tg mice). The plasma Trp3-ghrelin concentration in Trp3-ghrelin Tg mice was approximately 85-fold higher than plasma ghrelin (acylated ghrelin) concentration seen in the control mice. Because Trp3-ghrelin is approximately 24-fold less potent than ghrelin, the plasma Trp3-ghrelin concentration in Trp3-ghrelin Tg mice was calculated to have approximately 3.5-fold biological activity greater than that of ghrelin (acylated ghrelin) in the control mice. Trp3-ghrelin Tg mice did not show any phenotypes except for reduced insulin sensitivity in 1-year old. After the identification of ghrelin O-acyltransferase (GOAT), we generated doubly Tg mice overexpressing both mouse des-acyl ghrelin and mouse GOAT in the liver by cross-mating the two kinds of Tg mice. The plasma ghrelin concentration of doubly Tg mice was approximately 2-fold higher than that of the control mice. No apparent phenotypic changes in body weight and food intake were observed in doubly Tg mice. Further studies are ongoing in our laboratory to generate Tg mice with the increased plasma ghrelin level to a greater extent. The better understanding of physiological and pathophysiological significance of ghrelin from experiments using an excellent animal model may provide a new therapeutic approach for human diseases.

Neuronal cells derived from human induced pluripotent stem cells as a functional tool of melanocortin system.

BACKGROUND: The preparation of human neurons derived from human induced pluripotent stem (iPS) cells can serve as a potential tool for evaluating the physiological and pathophysiological properties of human neurons and for drug development. METHODS: In the present study, the functional activity in neuronal cells differentiated from human iPS cells was observed. RESULTS: The differentiated cells expressed mRNAs for classical neuronal markers (microtubule-associated protein 2, ß-tubulin III, calbindin 1, synaptophysin and postsynaptic density protein 95) and for subunits of various excitatory and inhibitory transmitters (NR1, NR2A, NR2B, GABAA α1). Moreover, the differentiated cells expressed neuropeptides and receptors which are predominantly present in the hypothalamus. The expression of mRNA for preopiomelanocortin, agouti-related protein (AgRP), melanocortin-3 receptor (MC3R) and melanocortin-4 receptor (MC4R) increased in culture with a peak on Day 30 which subsequently decreased at Day 45. Immunoreactivities for MC3R and MC4R were also observed in cells differentiated from human iPS cells. Application of a potent agonist for MC3R and MC4R, [Nle4, D-Phe7]-α-melanocyte-stimulating hormone, significantly increased intracellular cAMP levels, but this was suppressed by AgRP (83-132) and SHU9119. CONCLUSIONS: These findings offer the possibility for drug developments using neurons differentiated from normal or disease-associated human iPS cells.

Impaired adipogenic capacity in induced pluripotent stem cells from lipodystrophic patients with BSCL2 mutations.

OBJECTIVE: Congenital generalized lipodystrophy (CGL) is an autosomal recessive disorder characterized by marked scarcity of adipose tissue, extreme insulin resistance, hypertriglyceridemia, hepatic steatosis and early-onset diabetes. Mutation of the BSCL2/SEIPIN gene causes the most severe form of CGL. The aim of this study was to generate induced pluripotent stem (iPS) cells from patients with CGL harboring BSCL2/SEIPIN mutations. METHODS: Skin biopsies were obtained from two Japanese patients with CGL harboring different nonsense mutations (E189X and R275X) in BSCL2/SEIPIN. The fibroblasts thus obtained were infected with retroviruses encoding OCT4, SOX2, c-MYC, and KLF4. The generated iPS cells were evaluated for pluripotency by examining the expression of pluripotency markers (alkaline phosphatase, SSEA-4, TRA-1-60, and NANOG) and their ability to differentiate to three germ layers in vitro by forming embryoid bodies, and to form teratomas in vivo. Adipogenic capacity of differentiated BSCL2-iPS cells was determined by oil red O and adipose differentiation-related protein (ADRP) staining. Rescue experiments were also performed using stable expression of wild-type BSCL2. A coimmunoprecipitation assay was conducted to investigate the interaction of SEIPIN with ADRP. RESULTS: iPS cells were generated from fibroblasts of the two patients with CGL. Each of the patient-derived iPS (BSCL2-iPS) clones showed all of the hallmarks of pluripotency and could differentiate into derivatives of all three germ layers in vitro by forming embryoid bodies, and form teratomas after injection into mouse testes. BSCL2-iPS cells maintained the mutations in BSCL2 and lacked intact BSCL2. Upon adipogenic differentiation, BSCL2-iPS cells exhibited marked reduction of lipid droplet formation concomitant with diffuse cytoplasmic distribution of ADRP, compared with iPS cells from healthy individuals. Forced expression of BSCL2 not only rescued the lipid accumulation defects, but also restored cytoplasmic punctate localization of ADRP in BSCL2-iPS cells. Coimmunoprecipitation indicated SEIPIN interacted with ADRP. CONCLUSION: BSCL2-iPS cells that recapitulate the lipodystrophic phenotypes in vitro could provide valuable models with which to study the physiology of lipid accumulation and the pathology of human lipodystrophy. We found that BSCL2 defines the localization of ADRP, which has a role in lipid accumulation and adipogenic differentiation.

Leptin restores the insulinotropic effect of exenatide in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet.

Leptin may reduce pancreatic lipid deposition, which increases with progression of obesity and can impair ß-cell function. The insulinotropic effect of glucagon-like peptide-1 (GLP-1) and the efficacy of GLP-1 receptor agonist are reduced associated with impaired ß-cell function. In this study, we examined whether leptin could restore the efficacy of exenatide, a GLP-1 receptor agonist, in type 2 diabetes with increased adiposity. We chronically administered leptin (500 µg·kg⁻¹·day⁻¹) and/or exenatide (20 µg·kg⁻¹·day⁻¹) for 2 wk in a mouse model of type 2 diabetes with increased adiposity induced by streptozotocin and high-fat diet (STZ/HFD mice). The STZ/HFD mice exhibited hyperglycemia, overweight, increased pancreatic triglyceride level, and reduced glucose-stimulated insulin secretion (GSIS); moreover, the insulinotropic effect of exenatide was reduced. However, leptin significantly reduced pancreatic triglyceride level, and adding leptin to exenatide (LEP/EX) remarkably enhanced GSIS. These results suggested that the leptin treatment restored the insulinotropic effect of exenatide in the mice. In addition, LEP/EX reduced food intake, body weight, and triglyceride levels in the skeletal muscle and liver, and corrected hyperglycemia to a greater extent than either monotherapy. The pair-feeding experiment indicated that the marked reduction of pancreatic triglyceride level and enhancement of GSIS by LEP/EX occurred via mechanisms other than calorie restriction. These results suggest that leptin treatment may restore the insulinotropic effect of exenatide associated with the reduction of pancreatic lipid deposition in type 2 diabetes with increased adiposity. Combination therapy with leptin and exenatide could be an effective treatment for patients with type 2 diabetes with increased adiposity.

Cancer-promoting role of adipocytes in asbestos-induced mesothelial carcinogenesis through dysregulated adipocytokine production.

Like many other human cancers, the development of malignant mesothelioma is closely associated with a chronic inflammatory condition. Both macrophages and mesothelial cells play crucial roles in the inflammatory response caused by asbestos exposure. Here, we show that adipocytes can also contribute to asbestos-induced inflammation through dysregulated adipocytokine production. 3T3-L1 preadipocytes were differentiated into mature adipocytes prior to use. These cells took up asbestos fibers (chrysotile, crocidolite and amosite) but were more resistant to asbestos-induced injury than macrophages and mesothelial cells. Expression microarray analysis followed by reverse transcription-PCR revealed that adipocytes respond directly to asbestos exposure with an increased production of proinflammatory adipocytokines [e.g. monocyte chemoattractant protein-1 (MCP-1)], whereas the production of anti-inflammatory adipocytokines (e.g. adiponectin) is suppressed. This was confirmed in epididymal fat pad of mice after intraperitoneal injection of asbestos fibers. Such dysregulated adipocytokine production favors the establishment of a proinflammatory environment. Furthermore, MCP-1 marginally promoted the growth of MeT-5A mesothelial cells and significantly enhanced the wound healing of Y-MESO-8A and Y-MESO-8D human mesothelioma cells. Our results suggest that increased levels of adipocytokines, such as MCP-1, can potentially contribute to the promotion of mesothelial carcinogenesis through the enhanced recruitment of inflammatory cells as well as a direct growth and migration stimulatory effect on mesothelial and mesothelioma cells. Taken together, our findings support a potential cancer-promoting role of adipocytes in asbestos-induced mesothelial carcinogenesis.

In vitro characterization and engraftment of adipocytes derived from human induced pluripotent stem cells and embryonic stem cells.

Human induced pluripotent stem (iPS) and embryonic stem (ES) cells can differentiate into a variety of cell types. We reported on adipogenic potential of human iPS and ES cells in vitro. In the present study, we investigate the survival and maintenance of adipocytes differentiated in vitro from human iPS and ES cells after transplantation. Following adipogenic induction in vitro, the differentiated cells exhibited functional properties of adipocytes such as lipid storage, lipolysis, and insulin responsiveness. Subsequently, Matrigel containing the differentiated human iPS and ES cells was transplanted into the subcutaneous tissue of nude mice. After 1-4 weeks, the cells with adipocyte-like features were observed in transplanted Matrigel by histological analysis. The human origin of the cells, their lipid accumulation, and gene expression of adipocyte markers in transplanted cells were then confirmed, suggesting the presence of adipocytes in transplanted Matrigel. When the relative areas of these cells were calculated by dividing the adipocyte areas by the total Matrigel areas, we found that they peaked at 2 weeks after transplantation, and that the adipocytes persisted at 4 weeks. The present study demonstrates that human iPS and ES cells can differentiate into adipocytes with functional properties and that adipocytes derived from human iPS and ES cells can survive and maintain the differentiated properties of adipocytes for at least 4 weeks after transplantation. Adipocytes derived from human iPS and ES cells thus have the potential to open new avenues for stem cell-based research into metabolic diseases and future therapeutic applications.