FOXO1 cooperates with C/EBPδ and ATF4 to regulate skeletal muscle atrophy transcriptional program during fasting.

Catabolic conditions, such as starvation, inactivity, and cancer cachexia, induce Forkhead box O (FOXO) transcription factor(s) expression and severe muscle atrophy via the induction of ubiquitin-proteasome system-mediated muscle proteolysis, resulting in frailty and poor quality of life. Although FOXOs are clearly essential for the induction of muscle atrophy, it is unclear whether there are other factors involved in the FOXO-mediated transcriptional regulation. As such, we identified FOXO-CCAAT/enhancer-binding protein δ (C/EBPδ) signaling pathway as a novel proteolytic pathway. By comparing the gene expression profiles of FOXO1-transgenic (gain-of-function model) and FOXO1,3a,4-/- (loss-of-function model) mice, we identified several novel FOXO1-target genes in skeletal muscle including Redd1, Sestrin1, Castor2, Chac1, Depp1, Lat3, as well as C/EBPδ. During starvation, C/EBPδ abundance was increased in a FOXOs-dependent manner. Notably, knockdown of C/EBPδ prevented the induction of the ubiquitin-proteasome system and decrease of myofibers in FOXO1-activated myotubes. Conversely, C/EBPδ overexpression in primary myotubes induced myotube atrophy. Furthermore, we demonstrated that FOXO1 enhances the promoter activity of target genes in cooperation with C/EBPδ and ATF4. This research comprehensively identifies novel FOXO1 target genes in skeletal muscle and clarifies the pathophysiological role of FOXO1, a master regulator of skeletal muscle atrophy.

Cardiovascular complications in insulin resistance and endocrine diseases.

Cerebrovascular diseases, such as stroke and cardiovascular disease, are one of the leading causes of death in Japan. Type 2 diabetes is the most common form of diabetes and an important risk factor for these diseases. Among various pathological conditions associated with type 2 diabetes, insulin resistance has already been reported to be an important risk factor for diabetic complications. The major sites of insulin action in glucose metabolism in the body include the liver, skeletal muscle, and adipose tissue. However, insulin signaling molecules are also constitutively expressed in vascular endothelial cells, vascular smooth muscle, and monocytes/macrophages. Forkhead box class O family member proteins (FoxOs) of transcription factors play important roles in regulating glucose and lipid metabolism, oxidative stress response and redox signaling, and cell cycle progression and apoptosis. FoxOs in vascular endothelial cells strongly promote arteriosclerosis by suppressing nitric oxide production, enhancing inflammatory response, and promoting cellular senescence. In addition, primary aldosteronism and Cushing's syndrome are known to have adverse effects on the cardiovascular system, apart from hypertension, diabetes, and dyslipidemia. In the treatment of endocrine disorders, hormonal normalization by surgical treatment and receptor antagonists play an important role in preventing cardiovascular complications.

Intelectin1 ameliorates macrophage activation via inhibiting the nuclear factor kappa B pathway.

Inteletin1 (Itln1) is an adipokine that is abundantly expressed in intestine, ovary, and lung. The expression levels of ITLN1 are decreased in the presence of diabetes or obesity, but the mechanisms of its production and function are still controversial. The aim of this study is to elucidate the mechanisms of ITLN1 synthesis and ITLN1-associated macrophage activation. To analyze the effects of high fat and high-carbohydrate diet (HFHCD) on the expression of ITLN1 in the intestine, the mice were fed a HFHCD for 8 weeks. HFHCD feeding enhanced the endoplasmic reticulum (ER)-stress in the intestine and inhibited the expression of Itln1 in the intestinal endocrine cells and lowered circulating ITLN1 levels. In contrast, treatment with a chemical chaperone and reduction of ER-stress restored the expression of Itln1 in the intestine of HFHCD-fed mice. Furthermore, in vitro studies indicated that ITLN1 physically interacts with adiponectin receptor 1 and suppresses lipopolysaccharide-induced mRNA expressions of pro-inflammatory cytokines and phagocytosis activities via inhibition of the nuclear factor kappa B-signaling pathway in macrophages. These results suggest that diet-induced ER-stress decreases circulating ITLN1 via inhibition of its synthesis in the intestine, and a reduction of circulating ITLN1 might enhanced the expression of proinflammatory cytokines and macrophage activation, following exacerbate the chronic inflammation of metabolic syndrome.

Gestational body weight gain and risk of low birth weight or macrosomia in women of Japan: a nationwide cohort study.

OBJECTIVE: Both maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG) influence maternal and pediatric outcomes. We sought to clarify the impact of prepregnancy BMI-specific GWG and its patterns on the risk of low birth weight (LBW) or macrosomia using data from a large nationwide study in Japan. METHODS: This cohort study (n = 98,052) used data from the Japan Environment and Children's Study (JECS). The outcome variables in this study were LBW and macrosomia. We stratified the subjects into groups according to prepregnancy BMI. RESULTS: GWG from pre-pregnancy to the first trimester had a small effect on the risk of LBW and macrosomia. From the first to second trimesters, insufficient GWG was associated with the risk of LBW, and from the second trimester to delivery, a GWG of less than 2 kg was associated with the risk of LBW. These associations were commonly observed in all prepregnancy BMI categories. Irrespective of the GWG from pre-pregnancy to the first trimester, GWG from the first to second trimesters affects LBW and/or macrosomia. Irrespective of the GWG from the first to second trimesters, GWG from the second trimester to delivery affects LBW and/or macrosomia. LBW or macrosomia was associated with the prevalence of a sustained low or high BMI percentile until three years of age, respectively. CONCLUSIONS: The present large national cohort study indicates that the risk of LBW or macrosomia is associated with GWG in women in Japan; the significance of this risk depends on the GWG patterns.

Ipragliflozin Ameliorates Diabetic Nephropathy Associated with Perirenal Adipose Expansion in Mice.

Sodium glucose cotransporter-2 (SGLT2) inhibitors inhibit the development of diabetic nephropathy (DN). We determined whether changes in perirenal fat (PRAT) by a SGLT2 inhibitor ipragliflozin (Ipra) contribute to the suppression of DN development. High-fat diet (HFD)-fed mice were used as a DN model and were treated with or without Ipra for 6 weeks. Ipra treatment reduced urinary albumin excretion (UAE) and glomerular hypertrophy in HFD-fed mice. In the PRAT of Ipra-treated mice, adipocyte size was increased, and inflammation, fibrosis, and adipocyte death were suppressed. In conditioned medium made from PRAT (PRAT-CM) of Ipra-treated mice, the concentration of leptin was significantly lower than PRAT-CM of mice without Ipra treatment. Serum leptin concentration in renal vein positively correlated with UAE. PRAT-CM from HFD-fed mice showed greater cell proliferation signaling in mouse glomerular endothelial cells (GECs) than PRAT-CM from standard diet-fed mice via p38MAPK and leptin-dependent pathways, whose effects were significantly attenuated in PRAT-CM from Ipra-treated mice. These findings suggest that Ipra-induced PRAT expansion may play an important role in the improvement of DN in HFD-fed mice. In vitro experiments suggest that reduced PRAT-derived leptin by Ipra could inhibit GECs proliferation, possibly contributing to the suppression of DN development.

Liver-Specific Overexpression of Prostasin Attenuates High-Fat Diet-Induced Metabolic Dysregulation in Mice.

The liver has a most indispensable role in glucose and lipid metabolism where we see some of the most serious worldwide health problems. The serine protease prostasin (PRSS8) cleaves toll-like receptor 4 (TLR4) and regulates hepatic insulin sensitivity under PRSS8 knockout condition. However, liver substrate proteins of PRSS8 other than TLR4 and the effect to glucose and lipid metabolism remain unclarified with hepatic elevation of PRSS8 expression. Here we show that high-fat-diet-fed liver-specific PRSS8 transgenic mice improved glucose tolerance and hepatic steatosis independent of body weight. PRSS8 amplified extracellular signal-regulated kinase phosphorylation associated with matrix metalloproteinase 14 activation in vivo and in vitro. Moreover, in humans, serum PRSS8 levels reduced more in type 2 diabetes mellitus (T2DM) patients than healthy controls and were lower in T2DM patients with increased maximum carotid artery intima media thickness (>1.1 mm). These results identify the regulatory mechanisms of PRSS8 overexpression over glucose and lipid metabolism, as well as excessive hepatic fat storage.

Dulaglutide improves glucocorticoid-induced hyperglycemia in inpatient care and reduces dose and injection frequency of insulin.

BACKGROUND: Glucocorticoid (GC)-induced hyperglycemia is characterized by elevated postprandial blood glucose, which commonly requires multiple insulin injections. We investigated whether a long-acting glucagon-like peptide-1 receptor agonist, dulaglutide (Dula), safely improved GC-induced hyperglycemia in inpatients, to reduce insulin injection frequency. METHODS: The data of hospitalized patients with GC-induced hyperglycemia treated with Dula (Dula group, n = 38) or without (non-Dula group, n = 38) were retrospectively evaluated. Baseline data were collected at the beginning of GC treatment. The primary outcome in this study was glycemic control, which was compared between the groups using the six-point blood glucose (before and 2 h after each meal) profiles at discharge. The daily injection frequency of injectable drugs at discharge were also compared between groups. RESULTS: No specific trend of underlying diseases was observed between the non-Dula and Dula groups. The proportion of patients previously administered with GC pulse therapy was comparable between the two groups. No significant differences were observed between groups, in the starting maintenance GC dose, GC dose at pretreatment of Dula and discharge, and cumulative GC dose during the observation. Six-point blood glucose levels at pretreatment and discharge were comparable between the two groups. However, daily injection frequency of injectable drugs and insulin dose were significantly lower in the Dula group than that in the non-Dula group. No differences were observed in the number of hypoglycemic events, the elevation of serum pancreatic enzyme levels, or gastrointestinal adverse events. CONCLUSION: These findings suggest that Dula could provide glycemic control while reducing the insulin dose and injection frequency in inpatients with GC-induced hyperglycemia. The occurrence of adverse events such as gastrointestinal symptoms and hypoglycemia did not increase in the Dula-treated patients compared to those not treated, suggesting its safety.

Ipragliflozin-induced adipose expansion inhibits cuff-induced vascular remodeling in mice.

BACKGROUND: Perivascular adipose tissue (PVAT) plays a critical role in the pathogenesis of cardiovascular disease. It is unclear whether inhibition of sodium glucose cotransporter 2 (SGLT2) in subjects with type 2 diabetes (T2DM) could affect PVAT characters, and whether the SGLT2 inhibitors-induced changes of adipose tissue, especially the alternation of adipose tissue-derived secretory factors, affect vascular pathophysiology. METHODS: Western-type diet (WD) fed wild-type mice were treated with or without an SGLT2 inhibitor ipragliflozin (Ipra) for 10 weeks. WEHI 274.1 and primary vascular smooth muscle cells were incubated with conditioned media (CM) of epididymal adipose tissue (Epi) or abdominal PVAT of Ipra- or vehicle-treated mice fed a WD. Epi of Ipra- or vehicle-treated mice fed a WD was implanted onto cuff-placed femoral arteries of apoE-deficient mice. RESULTS: Ipra increased adipocyte size associated with decreased expression of pro-inflammatory and fibrosis-related genes in abdominal PVAT of WD-fed mice. Ipra also suppressed WD-induced macrophages accumulation, fibrosis, and adipocyte death in abdominal PVAT. In CM of abdominal PVAT from Ipra-treated mice, concentration of leptin was significantly lower than that from vehicle-treated mice. In vitro, migration of WEHI 274.1 and primary vascular smooth muscle cells were more enhanced by CM of Epi or abdominal PVAT from vehicle-treated mice than that from Ipra-treated mice. Perivascular implantation of Epi from Ipra-treated mice to apolipoprotein E-deficient mice attenuated cuff-induced neointimal hyperplasia and vascular remodeling compared to that from vehicle-treated mice. CONCLUSIONS: The Ipra-induced changes of abdominal PVAT will lead to a better understanding of unveiled mechanisms by which SGLT2 inhibitors prevent cardiovascular complications in T2DM, and the development of new therapeutic strategies targeting PVAT.

Deficiency of ATP-Binding Cassette Transporters A1 and G1 in Endothelial Cells Accelerates Atherosclerosis in Mice.

OBJECTIVE: Plasma high-density lipoproteins have several putative antiatherogenic effects, including preservation of endothelial functions. This is thought to be mediated, in part, by the ability of high-density lipoproteins to promote cholesterol efflux from endothelial cells (ECs). The ATP-binding cassette transporters A1 and G1 (ABCA1 and ABCG1) interact with high-density lipoproteins to promote cholesterol efflux from ECs. To determine the impact of endothelial cholesterol efflux pathways on atherogenesis, we prepared mice with endothelium-specific knockout of Abca1 and Abcg1. APPROACH AND RESULTS: Generation of mice with EC-ABCA1 and ABCG1 deficiency required crossbreeding Abca1(fl/fl)Abcg1(fl/fl)Ldlr(-/-) mice with the Tie2Cre strain, followed by irradiation and transplantation of Abca1(fl/fl)Abcg1(fl/fl) bone marrow to abrogate the effects of macrophage ABCA1 and ABCG1 deficiency induced by Tie2Cre. After 20 to 22 weeks of Western-type diet, both single EC-Abca1 and Abcg1 deficiency increased atherosclerosis in the aortic root and whole aorta. Combined EC-Abca1/g1 deficiency caused a significant further increase in lesion area at both sites. EC-Abca1/g1 deficiency dramatically enhanced macrophage lipid accumulation in the branches of the aorta that are exposed to disturbed blood flow, decreased aortic endothelial NO synthase activity, and increased monocyte infiltration into the atherosclerotic plaque. Abca1/g1 deficiency enhanced lipopolysaccharide-induced inflammatory gene expression in mouse aortic ECs, which was recapitulated by ABCG1 deficiency in human aortic ECs. CONCLUSIONS: These studies provide direct evidence that endothelial cholesterol efflux pathways mediated by ABCA1 and ABCG1 are nonredundant and atheroprotective, reflecting preservation of endothelial NO synthase activity and suppression of endothelial inflammation, especially in regions of disturbed arterial blood flow.

Expression of inflammation-related genes in aldosterone-producing adenomas with KCNJ5 mutation.

BACKGROUND: The adrenocortical cells have been shown to produce various inflammatory cytokines such as TNFα and IL-6, which could modulate steroidogenesis. However, the role of inflammatory cytokines in aldosterone-producing adenomas (APAs) is not fully understood. In the present study, we examined the relationships between mRNA expression levels of the inflammation-related genes and somatic mutations in APA tissues. METHODS: We evaluated mRNA expression levels of TNFA, IL6, and NFKB1 in APA tissues obtained from 44 Japanese APA patients. RESULTS: We revealed that mRNA expression patterns of the inflammation-related genes depended on a KCNJ5 somatic mutation. In addition, we showed that mRNA expression levels of the inflammation-related genes correlated with those of the steroidogenic enzyme CYP11B1 in the patients with APAs. CONCLUSION: The present study documented for the first time the expression of inflammation-related genes in APAs and the correlation of their expression levels with the KCNJ5 mutation status and mRNA expression levels of steroidogenic enzymes, indicating the pathophysiological relevance of inflammation-related genes in APAs.

[Lifestyle-related diseases and an inter-organ metabolic network].

Lifestyle-related diseases such as type 2 diabetes, hypertension and dyslipidemia are a prominent cause of mortality in Japan, and there is a strong requirement for elucidation of detailed molecular mechanisms and effective therapeutic strategies. Obesity-induced adipose tissue inflammation leads to dysregulation of adipokine production, which can cause lifestyle-related diseases. The interaction of organ systems via endocrine or neural networks is recognized as an important factor in the pathogenesis and promotion of lifestyle-related diseases. Therefore, further investigation for the interaction between adipose tissues and bones can provide new treatment strategies of metabolic bone disorders.

Expanded granulocyte/monocyte compartment in myeloid-specific triple FoxO knockout increases oxidative stress and accelerates atherosclerosis in mice.

RATIONALE: Increased neutrophil and monocyte counts are often associated with an increased risk of atherosclerosis, but their relationship to insulin sensitivity is unknown. OBJECTIVE: To investigate the contribution of forkhead transcription factors (FoxO) in myeloid cells to neutrophil and monocyte counts, atherosclerosis, and systemic insulin sensitivity. METHODS AND RESULTS: Genetic ablation of the 3 genes encoding FoxO isoforms 1, 3a, and 4, in myeloid cells resulted in an expansion of the granulocyte/monocyte progenitor compartment and was associated with increased atherosclerotic lesion formation in low-density lipoprotein receptor knockout mice. In vivo and ex vivo studies indicate that FoxO ablation in myeloid cells increased generation of reactive oxygen species. Accordingly, treatment with the antioxidant N-acetyl-l-cysteine reversed the phenotype, normalizing atherosclerosis. CONCLUSIONS: Our data indicate that myeloid cell proliferation and oxidative stress can be modulated via the FoxO branch of insulin receptor signaling, highlighting a heretofore-unknown link between insulin sensitivity and leukocytosis that can affect the predisposition to atherosclerosis.

Endothelial acyl-CoA synthetase 1 is not required for inflammatory and apoptotic effects of a saturated fatty acid-rich environment.

OBJECTIVE: Saturated fatty acids, such as palmitic and stearic acid, cause detrimental effects in endothelial cells and have been suggested to contribute to macrophage accumulation in adipose tissue and the vascular wall, in states of obesity and insulin resistance. Long-chain fatty acids are believed to require conversion into acyl-CoA derivatives to exert most of their detrimental effects, a reaction catalyzed by acyl-CoA synthetases (ACSLs). The objective of this study was to investigate the role of ACSL1, an ACSL isoform previously shown to mediate inflammatory effects in myeloid cells, in regulating endothelial cell responses to a saturated fatty acid-rich environment in vitro and in vivo. METHODS AND RESULTS: Saturated fatty acids caused increased inflammatory activation, endoplasmic reticulum stress, and apoptosis in mouse microvascular endothelial cells. Forced ACSL1 overexpression exacerbated the effects of saturated fatty acids on apoptosis and endoplasmic reticulum stress. However, endothelial ACSL1 deficiency did not protect against the effects of saturated fatty acids in vitro, nor did it protect insulin-resistant mice fed a saturated fatty acid-rich diet from macrophage adipose tissue accumulation or increased aortic adhesion molecule expression. CONCLUSIONS: Endothelial ACSL1 is not required for inflammatory and apoptotic effects of a saturated fatty acid-rich environment.

Height and Weight, Not Body Mass Index, Are Closely Associated With Activities of Daily Living in Japanese Older Adults.

Body mass index (BMI) is routinely used to ascertain health status, including activities of daily living (ADLs); however, the associations of ADLs with height and weight in older adults have not been elucidated. Therefore, we cross-sectionally investigated the correlations between ADLs and height, weight, and BMI in 155 participants aged 82 to 103 years and characterized the naïve Bayesian prediction for ADLs. Activities of daily living showed a significant negative correlation with height and weight and a positive correlation with age. In males, a shorter height was associated with an increased risk of falling and disability in phone calling independently, and losing weight was associated with an increased risk of disability in going out. Combining age, weight, and height improved the area under the receiver operating characteristic curve in the prediction of disability in going out and phone calling independently in males. Therefore, height and weight, not BMI, are potential predictors of ADL decline.

Subclinical Cushing's Disease with High-Molecular-Weight Forms of Adrenocorticotropic Hormone Production.

Production of the high-molecular-weight forms of adrenocorticotropic hormone (big-ACTH) has been reported in a small number of ectopic ACTH syndrome and ACTH-producing pituitary macroadenoma. However, perioperative changes in big-ACTH in patients with subclinical Cushing's disease have not been reported. A 63-year-old woman presented 25 × 20 × 20-mm-sized macroadenoma in the pituitary gland. Her early morning plasma ACTH and cortisol levels were 111 pg/mL and 11.6 µg/dL, respectively. Cushingoid features and diurnal variation in plasma cortisol levels were not observed. The patient's urinary free cortisol (UFC) was 59.3 µg/day. The corticotropin-releasing hormone (CRH) test showed that plasma ACTH levels were 1.5 times higher than the preload value. The overnight dexamethasone suppression test (DST) showed that the plasma cortisol level was not suppressed by 0.5 mg of dexamethasone (DEX) but was suppressed by 8 mg of DEX. Inferior pyramidal sinus sampling was consistent with Cushing's disease. Taken together, the patient was clinically diagnosed with subclinical Cushing's disease caused by an ACTH-producing pituitary adenoma. Endoscopic transsphenoidal adenomectomy was performed. In the postoperative CRH test, plasma ACTH levels showed six-fold increase. The postoperative DST showed cortisol suppression at 0.5 mg of DEX. The UFC levels decreased to 35.1 µg/day. Pituitary contrast-enhanced MRI revealed no residual tumor, and plasma ACTH and cortisol levels remained within normal ranges. Gel filtration of preoperative and postoperative plasma ACTH was performed, and a high molecular weight fraction of ACTH was detected, which markedly decreased postoperatively. The absence of Cushingoid features and the lack of significant cortisol hypersecretion in this case were thought to be due in part to big-ACTH, which has low bioactivity. By careful evaluation of laboratory and clinical findings, we identified it as a big-ACTH-producing adenoma. This is the first report of a case in which the big-ACTH transition was observed perioperative and is a valuable case.

Rapid improvement of severe fatty liver in a case of fulminant type 1 diabetes following insulin treatment.

A 36-year-old woman presented to the emergency room with a consciousness disorder after developing abdominal pain with diarrhea for 2 days. She presented with marked hyperglycemia, ketoacidosis, and increased serum free fatty acid (FFA) levels; however, no elevation in the glycated hemoglobin (HbA1c) levels was observed. Based on the marked depletion of insulin secretion, the patient was diagnosed as diabetic ketoacidosis attributed to fulminant type 1 diabetes (FT1D). Computed tomography on admission revealed severe fatty liver (FL), which improved 17 h following insulin treatment. Insulin treatment also suppressed the serum FFA levels. Some cases of FT1D with FL and liver dysfunction have been reported previously; however, its pathogenesis and clinical course remain unclear. Compared to previous reports, this case reported the shortest time for FL improvement. In this case, rapid and severe insulin deficiency led to a markedly high FFA level and significant accumulation of triglycerides in the hepatocytes, resulting in severe FL. A rapid and large dose of insulin was administered when systemic insulin sensitivity was nearly maximal owing to insulin deficiency, increased insulin efficacy, early reduction of FFA, suppressed triglyceride accumulation in the hepatocytes, and increased triglyceride excretion from the liver. All these factors could have contributed to the rapid improvement in FL.

Moon-like Facies by Glucocorticoid Is Associated With the Development of Diabetes and Body Image Disturbance.

Context: Moon-like facies (MLF) are a typical side effect of glucocorticoid (GC) therapy; however, its predisposing factors, relationship with GC-induced complications, and effects on body image are not well understood. Objective: This study aimed to determine the predisposing factors for MLF during GC therapy; its association with GC-induced diabetes, hypertension, and dyslipidemia; and its effects on body image. Methods: This prospective observational study spanned 24 weeks and targeted patients who received GC therapy at the University of Yamanashi Hospital from June 2020 to August 2022. The MLF was defined based on the following 3 factors: (1) an increase in facial measurement lengths, (2) subjective facial changes by patients' self-assessment using a visual analog scale; (3) objective and qualitative facial changes assessed by physicians. We examined the predisposing factors for MLF and the association of MLF with GC-induced diabetes, hypertension, dyslipidemia, and body image. Results: The cumulative incidence rate of MLF at 24 weeks was 37.6%. Predisposing factors for MLF were an initial oral prednisolone dosage of ≥ 30 mg/day [odds ratio (OR) 63.91, 95% confidence interval (CI) 5.82-701.81] and female (OR 6.66, 95% CI 1.35-32.79). MLF showed a significant association with the onset of GC-induced diabetes (OR 6.58, 95% CI 1.25-34.74). MLF was also an independent factor contributing to body image disturbance (ß = -18.94, P = .01). Conclusion: MLF contributes to body image disturbance and is associated with the development of GC-induced diabetes; therefore, it is clinically important as a physical manifestation of GC therapy.