Single-Cell Transcriptome Profiling of Pancreatic Islets From Early Diabetic Mice Identifies Anxa10 for Ca2+ Allostasis Toward β-Cell Failure

Type 2 diabetes is a progressive disorder denoted by hyperglycemia and impaired insulin secretion. Although a decrease in β-cell function and mass is a well-known trigger for diabetes, the comprehensive mechanism is still unidentified. Here, we performed single-cell RNA sequencing of pancreatic islets from prediabetic and diabetic db/db mice, an animal model of type 2 diabetes. We discovered a diabetes-specific transcriptome landscape of endocrine and nonendocrine cell types with subpopulations of β- and α-cells. We recognized a new prediabetic gene, Anxa10, that was induced by and regulated Ca2+ influx from metabolic stresses. Anxa10-overexpressed β-cells displayed suppression of glucose-stimulated intracellular Ca2+ elevation and potassium-induced insulin secretion. Pseudotime analysis of β-cells predicted that this Ca2+-surge responder cluster would proceed to mitochondria dysfunction and endoplasmic reticulum stress. Other trajectories comprised dedifferentiation and transdifferentiation, emphasizing acinar-like cells in diabetic islets. Altogether, our data provide a new insight into Ca2+ allostasis and β-cell failure processes.

ARTICLE HIGHLIGHTS

The transcriptome of single-islet cells from healthy, prediabetic, and diabetic mice was studied. Distinct β-cell heterogeneity and islet cell-cell network in prediabetes and diabetes were found. A new prediabetic β-cell marker, Anxa10, regulates intracellular Ca2+ and insulin secretion. Diabetes triggers β-cell to acinar cell transdifferentiation.

GR-KLF15 pathway controls hepatic lipogenesis during fasting

During periods of fasting, the body undergoes a metabolic shift from carbohydrate utilization to the use of fats and ketones as an energy source, as well as the inhibition of de novo lipogenesis and the initiation of gluconeogenesis in the liver. The transcription factor sterol regulatory element-binding protein-1 (SREBP-1), which plays a critical role in the regulation of lipogenesis, is suppressed during fasting, resulting in the suppression of hepatic lipogenesis. We previously demonstrated that the interaction of fasting-induced Kruppel-like factor 15 (KLF15) with liver X receptor serves as the essential mechanism for the nutritional regulation of SREBP-1 expression. However, the underlying mechanisms of KLF15 induction during fasting remain unclear. In this study, we show that the glucocorticoid receptor (GR) regulates the hepatic expression of KLF15 and, subsequently, lipogenesis through the KLF15-SREBP-1 pathway during fasting. KLF15 is necessary for the suppression of SREBP-1 by GR, as demonstrated through experiments using KLF15 knockout mice. Additionally, we show that GR is involved in the fasting response, with heightened binding to the KLF15 enhancer. It has been widely known that the hypothalamic-pituitary-adrenal (HPA) axis regulates the secretion of glucocorticoids and plays a significant role in the metabolic response to undernutrition. These findings demonstrate the importance of the HPA-axis-regulated GR-KLF15 pathway in the regulation of lipid metabolism in the liver during fasting.

Rhomboid protease RHBDL4/RHBDD1 cleaves SREBP-1c at endoplasmic reticulum monitoring and regulating fatty acids

The endoplasmic reticulum (ER)-embedded transcription factors, sterol regulatory element-binding proteins (SREBPs), master regulators of lipid biosynthesis, are transported to the Golgi for proteolytic activation to tune cellular cholesterol levels and regulate lipogenesis. However, mechanisms by which the cell responds to the levels of saturated or unsaturated fatty acids remain underexplored. Here, we show that RHBDL4/RHBDD1, a rhomboid family protease, directly cleaves SREBP-1c at the ER. The p97/VCP, AAA-ATPase complex then acts as an auxiliary segregase to extract the remaining ER-embedded fragment of SREBP-1c. Importantly, the enzymatic activity of RHBDL4 is enhanced by saturated fatty acids (SFAs) but inhibited by polyunsaturated fatty acids (PUFAs). Genetic deletion of RHBDL4 in mice fed on a Western diet enriched in SFAs and cholesterol prevented SREBP-1c from inducing genes for lipogenesis, particularly for synthesis and incorporation of PUFAs, and secretion of lipoproteins. The RHBDL4-SREBP-1c pathway reveals a regulatory system for monitoring fatty acid composition and maintaining cellular lipid homeostasis.

Loss of CtBP2 may be a mechanistic link between metabolic derangements and progressive impairment of pancreatic β cell function

The adaptive increase in insulin secretion in early stages of obesity serves as a safeguard mechanism to maintain glucose homeostasis that cannot be sustained, and the eventual decompensation of β cells is a key event in the pathogenesis of diabetes. Here we describe a crucial system orchestrated by a transcriptional cofactor CtBP2. In cultured β cells, insulin gene expression is coactivated by CtBP2. Global genomic mapping of CtBP2 binding sites identifies a key interaction between CtBP2 and NEUROD1 through which CtBP2 decompacts chromatin in the insulin gene promoter. CtBP2 expression is diminished in pancreatic islets in multiple mouse models of obesity, as well as human obesity. Pancreatic β cell-specific CtBP2-deficient mice manifest glucose intolerance with impaired insulin secretion. Our transcriptome analysis highlights an essential role of CtBP2 in the maintenance of β cell integrity. This system provides clues to the molecular basis in obesity and may be targetable to develop therapeutic approaches.

Nanopipette Fabrication Guidelines for SICM Nanoscale Imaging

Scanning ion conductance microscopy (SICM) is a promising tool for visualizing the dynamics of nanoscale cell surface topography. However, there are still no guidelines for fabricating nanopipettes with ideal shape consisting of small apertures and thin glass walls. Therefore, most of the SICM imaging has been at a standstill at the submicron scale. In this study, we established a simple and highly reproducible method for the fabrication of nanopipettes with sub-20 nm apertures. To validate the improvement in the spatial resolution, we performed time-lapse imaging of the formation and disappearance of endocytic pits as a model of nanoscale time-lapse topographic imaging. We have also successfully imaged the localization of the hot spot and the released extracellular vesicles. The nanopipette fabrication guidelines for the SICM nanoscale topographic imaging can be an essential tool for understanding cell-cell communication.

Obesity-induced metabolic imbalance allosterically modulates CtBP2 to inhibit PPAR-alpha transcriptional activity

Maintenance of metabolic homeostasis is secured by metabolite-sensing systems, which can be overwhelmed by constant macronutrient surplus in obesity. Not only the uptake processes but also the consumption of energy substrates determine the cellular metabolic burden. We herein describe a novel transcriptional system in this context comprised of peroxisome proliferator-activated receptor alpha (PPARα), a master regulator for fatty acid oxidation, and C-terminal binding protein 2 (CtBP2), a metabolite-sensing transcriptional co-repressor. CtBP2 interacts with PPARα to repress its activity, and the interaction is enhanced upon binding to malonyl-CoA, a metabolic intermediate increased in tissues in obesity and reported to suppress fatty acid oxidation through inhibition of carnitine palmitoyltransferase 1 (CPT1). In line with our preceding observations that CtBP2 adopts a monomeric configuration upon binding to acyl-CoAs, we determined that mutations in CtBP2 that shift the conformational equilibrium toward monomers increase the interaction between CtBP2 and PPARα. In contrast, metabolic manipulations that reduce malonyl-CoA decreased the formation of the CtBP2/PPARα complex. Consistent with these in vitro findings, we found that the CtBP2/PPARα interaction is accelerated in obese livers while genetic deletion of CtBP2 in the liver causes derepression of PPARα target genes. These findings support our model where CtBP2 exists primarily as a monomer in the metabolic milieu of obesity to repress PPARα, representing a liability in metabolic diseases that can be exploited to develop therapeutic approaches.

Activity-dependent glassy cell mechanics Ⅰ: Mechanical properties measured with active microrheology

Active microrheology was conducted in living cells by applying an optical-trapping force to vigorously-fluctuating tracer beads with feedback-tracking technology. The complex shear modulus G(ω)=G'(ω)-iG″(ω) was measured in HeLa cells in an epithelial-like confluent monolayer. We found that G(ω)∝(-iω)^1/2 over a wide range of frequencies (1 Hz <ω/2π <10 kHz). Actin disruption and cell-cycle progression from G1 to S and G2 phases only had a limited effect on G(ω) in living cells. On the other hand, G(ω) was found to be dependent on cell metabolism; ATP-depleted cells showed an increased elastic modulus G'(ω) at low frequencies, giving rise to a constant plateau such that G(ω)=G₀+A(-iω)^1/2 . Both the plateau and the additional frequency dependency ∝(-iω)^1/2 of ATP-depleted cells are consistent with a rheological response typical of colloidal jamming. On the other hand, the plateau G₀ disappeared in ordinary metabolically active cells, implying that living cells fluidize their internal states such that they approach the critical jamming point.

A case of NASH with genetic predisposition successfully treated with an SGLT2 inhibitor: a possible involvement of mitochondrial dysfunction

Summary

In this study, we herein describe a 47-year-old Japanese woman who manifested inheritable non-alcoholic steatohepatitis (NASH) and severe dyslipidemia. Interestingly, her NASH progression was ameliorated by treatment with a sodium-glucose co-transporter 2 (SGLT2) inhibitor. This inheritability prompted us to comprehensively decode her genomic information using whole-exome sequencing. We found the well-established I148M mutation in PNPLA3 as well as mutations in LGALS3 and PEMT for her NASH. Mutations in GCKR may contribute to both NASH and dyslipidemia. We further mined gene mutations potentially responsible for her manifestations that led to the identification of a novel M188fs mutation in MUL1 that may be causally associated with her mitochondrial dysfunction. Our case may provide some clues to better understand this spectrum of disease as well as the rationale for selecting medications.

Learning points

While the PNPLA3 I148M mutation is well-established, accumulation of other mutations may accelerate susceptibility to non-alcoholic steatohepatitis (NASH). NASH and dyslipidemia may be intertwined biochemically and genetically through several key genes. SGLT2 inhibitors emerge as promising treatment for NASH albeit with interindividual variation in efficacy. Genetic background may explain the mechanisms behind the variation. A novel dysfunctional mutation in MUL1 may lead to metabolic inflexibilities through impaired mitochondrial dynamics and function.

Hepatocyte- or macrophage-specific SREBP-1a deficiency in mice exacerbates methionine- and choline-deficient diet-induced nonalcoholic fatty liver disease

Sterol regulatory element-binding proteins (SREBPs) are master transcription factors for lipid synthesis, and SREBP-1 is important for fatty acid and triglyceride synthesis. SREBP-1 has two isoforms, SREBP-1a and SREBP-1c, which are splicing variants transcribed from the Srebf1 gene. Although SREBP-1a exhibits stronger transcriptional activity than SREBP-1c, hepatic SREBP-1c is considered more physiologically important. We generated SREBP-1a flox mice using the CRISPR/Cas9 system and hepatocyte- and macrophage-specific SREBP-1a knockout (KO) mice (LKO, liver-knockout; and mΦKO, macrophage-knockout). There were no significant differences among all the mouse genotypes upon feeding with a normal diet. However, feeding with a methionine- and choline-deficient (MCD) diet resulted in exacerbated liver injury in both KO mice. In LKO mice, fatty liver was unexpectedly exacerbated, leading to macrophage infiltration and inflammation. In contrast, in mΦKO mice, the fatty liver state was similar to that in flox mice, but the polarity of the macrophages in the liver was transformed into a proinflammatory M1 subtype, resulting in the exacerbation of inflammation. Taken together, we found that SREBP-1a does not contribute to hepatic lipogenesis, but in either hepatocytes or macrophages distinctly controls the onset of pathological conditions in MCD diet-induced hepatitis.NEW & NOTEWORTHY Hepatocyte- and macrophage-specific SREBP-1a knockout mice were generated for the first time. This study reveals that SREBP-1a does not contribute to hepatic lipogenesis, but in either hepatocytes or macrophages distinctly controls the onset of pathological conditions in methionine- and choline-deficient diet-induced hepatitis.

Heat shock-induced heme oxygenase-1 expression in a mouse hepatoma cell line is dependent on HSF1 and modified by NRF2 and BACH1

The induction mechanism of heme oxygenase-1 (HO-1) by heat shock (HS) is still unknown. Here, we discovered that HS activates the HO-1 expression in a mouse hepatoma cell line (Hepa 1-6). Knockdown experiments showed that the HS-induced HO-1 expression was dependent on heat shock factor 1 (HSF1). A chromatin immunoprecipitation (ChIP) assay demonstrated that the HS-activated HSF1 bound to the heat shock elements (HSEs) in the upstream enhancer 1 region (E1). Unexpectedly, HS also facilitates the BTB and CNC homology 1 (BACH1) binding to the Maf recognition elements (MAREs) in E1. We examined the effects of a catalytically inactive CRISPR-associated 9 nucleases (dCas9) with short guide RNAs (sgRNAs), and demonstrated that the HSF1 binding to HSEs in E1 was indispensable for the HS-induced HO-1 expression. Heme treatment (HA) dissociates BACH1 from MAREs and facilitated the binding of nuclear factor-erythroid-2-related factor 2 (NRF2) to MAREs. Following treatment with both HS and HA, the HO-1 induction and the HSF1 binding to HSEs in E1 were most notably observed. These results indicate that the HS-induced HO-1 expression is dependent on the HSF1 binding to HSEs in E1, although modulated by the BACH1 and NRF2 binding to MAREs within the same E1. This article is protected by copyright. All rights reserved.

ELOVL5-mediated fatty acid elongation promotes cellular proliferation and invasion in renal cell carcinoma

Renal cell carcinoma (RCC) features altered lipid metabolism and accumulated polyunsaturated fatty acids (PUFAs). Elongation of very long–chain fatty acid (ELOVL) family enzymes catalyze fatty acid elongation, and ELOVL5 is indispensable for PUFAs elongation, but its role in RCC progression remains unclear. Here, we show that higher levels of ELOVL5 correlate with poor RCC clinical prognosis. Liquid chromatography/electrospray ionization‐tandem mass spectrometry analysis showed decreases in ELOVL5 end products (arachidonic acid and eicosapentaenoic acid) under CRISPR/Cas9‐mediated knockout of ELOVL5 while supplementation with these fatty acids partially reversed the cellular proliferation and invasion effects of ELOVL5 knockout. Regarding cellular proliferation and invasion, CRISPR/Cas9‐mediated knockout of ELOVL5 suppressed the formation of lipid droplets and induced apoptosis via endoplasmic reticulum stress while suppressing renal cancer cell proliferation and in vivo tumor growth. Furthermore, CRISPR/Cas9‐mediated knockout of ELOVL5 inhibited AKT Ser473 phosphorylation and suppressed renal cancer cell invasion through chemokine (C‐C motif) ligand‐2 downregulation by AKT‐mTOR‐STAT3 signaling. Collectively, these results suggest that ELOVL5‐mediated fatty acid elongation promotes not only cellular proliferation but also invasion in RCC.

OP0062 EFFICACY AND SAFETY OF ADALIMUMAB WITH LOW AND HIGH DOSE-METHOTREXATE IN PATIENTS WITH RHEUMATOID ARTHRITIS WITH INADEQUATE RESPONSE TO METHOTREXATE: THE RANDOMISED CONTROLLED MIRACLE STUDY

Background

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that causes not only joint pain but also bone destruction resulting in impairment of quality of life. Tumor necrosis factor inhibitors have improved prognosis of patients with rheumatoid arthritis dramatically, especially in combination with methotrexate, however, the optimal dose of the concomitant methotrexate is unclear.

Objectives

To evaluate the efficacy and safety of adalimumab in combination with reduced dose of methotrexate in patients with early RA with inadequate response to methotrexate.

Methods

The MIRACLE study was a multinational, randomized, open-label study in patients with RA with inadequate response to methotrexate conducted in Asia. It compared low dose and high dose methotrexate upon starting adalimumab. Methotrexate-naive patients with RA with a disease duration of less than two years started methotrexate at 6 to 8 mg/week and increased it to the maximum tolerable dose by week 12. Patients who have not achieved remission according to simplified disease activity index (SDAI) despite methotrexate ≥ 10 mg/week at week 24 were randomised to the maximum tolerable dose of methotrexate group (10 to 25 mg/week) or the reduced dose group (6 to 8 mg/week) and started to receive subcutaneous adalimumab 40 mg every other week. The primary endpoint was non-inferiority in the achievement of SDAI remission at week 48 in the reduced dose group compared with the maximum tolerable dose group with a non-inferiority margin of -15% based on two-sided 90% confidence interval. (NCT03505008)

Results

A total of 300 patients were enrolled in the study. Among them, 291 started methotrexate and were included in the analysis. The mean age was 57.7±15.2 years, female was 74.6%, and the mean disease duration from the diagnosis of RA was 21.1±56.2 days. Anti-CCP antibody was positive in 211 (73.0%) and the mean SDAI at study enrollment was 26.5±12.4. At week 24, with the mean dose of methotrexate of 12.6±2.9 mg/week, 108 patients (37.1%) achieved remission according to SDAI and continued MTX monotherapy. 134 patients (46.0%) were randomised and started adalimumab with 68 patients in the maximum tolerable dose group and 66 patients in the reduced dose group. At week 48, the remission achievement rates were 38.4 % and 44.8 %, respectively, with the adjusted risk difference of the reduced dose group to the maximum tolerable dose group of 6.4% (-7.0% to 19.8%, 90% CI), which met the criterion for noninferiority. No significant difference was found in health assessment questionnaire disability index ≤0.5 (59.1% vs 62.0%, respectively, p=0.72) and in radiological remission rates (Δmodified total Sharp score ≤0.5, 66.3% vs 62.0 %, respectively, p=0.59). Adverse drug reactions tended to be more frequent in the maximum tolerable dose group than in the reduced dose group (22.1% vs 9.1%, respectively, p=0.06).

Conclusion

The MIRACLE randomised study demonstrated that, in patients with inadequate response to methotrexate, the efficacy of adalimumab with reduced dose of concomitant methotrexate was not inferior to that with maximum tolerable dose of methotrexate with better safety profile.

Disclosure of Interests

Hiroya Tamai Speakers bureau: Eisai, Grant/research support from: Eisai, Kei Ikeda Speakers bureau: AbbVie, Eisai, Eli Lilly, Novartis, Gilead, Asahi-Kasei, Grant/research support from: Mitsubishi-Tanabe, Toshiaki Miyamoto: None declared, Hiroaki Taguchi: None declared, Chang-Fu Kuo: None declared, Kichul Shin: None declared, Shintaro Hirata Speakers bureau: AbbVie, Asahi-Kasei, Astellas, Ayumi, Bristol Myers Squibb, Celgene, Chugai, Eisai, Eli Lilly, Gilead, Glaxo SmithKline, Janssen, Kyorin, Novartis, Pfizer, Sanofi, Tanabe-Mitsubishi, UCB, Paid instructor for: AbbVie, Mitsubishi-Tanabe, Consultant of: AbbVie, Astellas, Bristol Myers Squibb, Eisai, Gilead, Ily Lilly, Grant/research support from: AbbVie, Asahi-Kasei, Eisai, Otsuka, Sanofi, Shionogi, Chugai, Pfizer, Tanabe-Mitsubishi, Eli Lilly, UCB, yutaka okano: None declared, Shinji Sato Speakers bureau: AbbVie, Eisai, Grant/research support from: AbbVie, Eisai, Hidekata Yasuoka Speakers bureau: AbbVie, Asahi Kasei Pharma, Astellas, Daiichi-Sankyo, Eisai, Kissei, Takeda, Mitsubishi-Tanabe, Chugai, Novartis, Eli Lilly, Pfizer, Janssen, Sanofi, Teijin, Boehringer-Ingelheim, Bayer, Glaxo Smith Kline, Paid instructor for: AbbVie, Consultant of: AbbVie, Asahi Kasei, Grant/research support from: Mitsubishi-Tanabe, Takeda, Daiichi-Sankyo, Chugai, Bristol-Myers, MSD, Astellas, In Ah Choi Speakers bureau: Abbvie, Eisai, Sung-Hwan Park: None declared, Meng-Yu Weng Paid instructor for: Novartis, Eli Lilly, ChuGai, Abbvie, Consultant of: Abbvie, Masataka Kuwana Speakers bureau: Astellas, Asahi Kasei Pharma, Boehringer-Ingelheim, Chugai, Eisai, Janssen, Mochida, Nippon Shinyaku, Ono Pharmaceuticals, Pfizer, Mitsubishi-Tanabe, Consultant of: Boehringer-Ingelheim, Kissei, Mochida, Grant/research support from: AbbVie, Asahi Kasei Pharma, Boehringer-Ingelheim, Chugai, Eisai, MBL, Nippon Shinyaku, Ono Pharmaceuticals, Mitsubishi-Tanabe, Yun Jong Lee Grant/research support from: Yuhan, Tomonori Ishii Speakers bureau: Chugai, Mitsubishi-Tanabe, Glaxo Smith Kline, Pfizer, Eli Lilly, Janssen, AbbVie, Eisai, Astellas, Jinhyun Kim: None declared, Hideto Kameda Speakers bureau: AbbVie, Pfizer, Consultant of: AbbVie, Grant/research support from: AbbVie, Eisai, Toshihisa Kojima Speakers bureau: AbbVie, Pfizer, Eisai, Grant/research support from: AbbVie, Han Joo Baek: None declared, Ping-Ning Hsu: None declared, Chun-Ming Huang Paid instructor for: Abbvie, Pfizer, Tien-Tsai Cheng Paid instructor for: Abbvie, Grant/research support from: Abbvie, Wan-Yu Sung: None declared, Takehiro Taninaga Shareholder of: Eisai.co.,Ltd., Employee of: Eisai.co.,Ltd., Masahiko Mori Shareholder of: Eisai.co.,Ltd., Employee of: Eisai.co.,Ltd., Hideaki Miyagishi Shareholder of: Eisai.co.,Ltd., Employee of: Eisai.co.,Ltd., Yasunori Sato Speakers bureau: Eisai Co., Ltd. Kowa Company, Ltd., Consultant of: MOCHIDA PHARMACEUTICAL CO., LTD, Tsutomu Takeuchi Speakers bureau: Astellas, AbbVie, Ayumi, Bristol Myers Squibb, Chugai, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Glaxo Smith Kline, Janssen, Mitsubishi-Tanabe, Nippon-kayaku, Novartis, Pfizer, Sanofi, UCB, Grant/research support from: Asahi Kasei, AbbVie, Ayumi, Boehringer-Ingelheim, Chugai, Eisai, Eli Lilly, Mitsubishi-Tanabe, Sanofi, UCB, Yuko Kaneko Speakers bureau: Asahi Kasei, Astellas, Ayumi, Bristol Myers Squibb, Chugai, Eisai, Elli Lilly, Mitsubishi-Tanabe, Novartis, UCB, Grant/research support from: AbbVie, Chugai, Eisai, Mitsubishi-Tanabe, UCB.

Morphological and functional adaptation of pancreatic islet blood vessels to insulin resistance is impaired in diabetic db/db mice

The pancreatic islet vasculature is of fundamental importance to the β-cell response to obesity-associated insulin resistance. To explore islet vascular alterations in the pathogenesis of type 2 diabetes, we evaluated two insulin resistance models: ob/ob mice, which sustain large β-cell mass and hyperinsulinemia, and db/db mice, which progress to diabetes due to secondary β-cell compensation failure for insulin secretion. Time-dependent changes in islet vasculature and blood flow were investigated using tomato lectin staining and in vivo live imaging. Marked islet capillary dilation was observed in ob/ob mice, but this adaptive change was blunted in db/db mice. Islet blood flow volume was augmented in ob/ob mice, whereas it was reduced in db/db mice. The protein concentrations of total and phosphorylated endothelial nitric oxide synthase (eNOS) at Ser1177 were increased in ob/ob islets, while they were diminished in db/db mice, indicating decreased eNOS activity. This was accompanied by an increased retention of advanced glycation end-products in db/db blood vessels. Amelioration of diabetes by Elovl6 deficiency involved a restoration of capillary dilation, blood flow, and eNOS phosphorylation in db/db islets. Our findings suggest that the disability of islet capillary dilation due to endothelial dysfunction impairs local islet blood flow, which may play a role in the loss of β-cell function and further exacerbate type 2 diabetes.

FoxO-KLF15 pathway switches the flow of macronutrients under the control of insulin

KLF15 is a transcription factor that plays an important role in the activation of gluconeogenesis from amino acids as well as the suppression of lipogenesis from glucose. Here we identified the transcription start site of liver-specific KLF15 transcript and showed that FoxO1/3 transcriptionally regulates Klf15 gene expression by directly binding to the liver-specific Klf15 promoter. To achieve this, we performed a precise in vivo promoter analysis combined with the genome-wide transcription-factor-screening method "TFEL scan", using our original Transcription Factor Expression Library (TFEL), which covers nearly all the transcription factors in the mouse genome. Hepatic Klf15 expression is significantly increased via FoxOs by attenuating insulin signaling. Furthermore, FoxOs elevate the expression levels of amino acid catabolic enzymes and suppress SREBP-1c via KLF15, resulting in accelerated amino acid breakdown and suppressed lipogenesis during fasting. Thus, the FoxO-KLF15 pathway contributes to switching the macronutrient flow in the liver under the control of insulin.

High protein diet-induced metabolic changes are transcriptionally regulated via KLF15-dependent and independent pathways

High protein diet (HPD) is an affordable and positive approach in prevention and treatment of many diseases. It is believed that transcriptional regulation is responsible for adaptation after HPD feeding and Kruppel-like factor 15 (KLF15), a zinc finger transcription factor that has been proved to perform transcriptional regulation over amino acid, lipid and glucose metabolism, is known to be involved at least in part in this HPD response. To gain more insight into molecular mechanisms by which HPD controls expressions of genes involved in amino acid metabolism in the liver, we performed RNA-seq analysis of mice fed HPD for a short period (3 days). Compared to a low protein diet, HPD feeding significantly increased hepatic expressions of enzymes involved in the breakdown of all the 20 amino acids. Moreover, using KLF15 knockout mice and in vivo Ad-luc analytical system, we were able to identify Cth (cystathionine gamma-lyase) as a new target gene of KLF15 transcription as well as Ast (aspartate aminotransferase) as an example of KLF15-independent gene despite its remarkable responsiveness to HPD. These findings provide us with a clue to elucidate the entire transcriptional regulatory mechanisms of amino acid metabolic pathways.

ELOVL2 promotes cancer progression by inhibiting cell apoptosis in renal cell carcinoma

Renal cell carcinoma (RCC) is an aggressive genitourinary malignancy which has been associated with a poor prognosis, particularly in patients with metastasis, its major subtypes being clear cell RCC (ccRCC), papillary PCC (pRCC) and chromophobe RCC (chRCC). The presence of intracellular lipid droplets (LDs) is considered to be a hallmark of ccRCC. The importance of an altered lipid metabolism in ccRCC has been widely recognized. The elongation of very-long-chain fatty acid (ELOVL) catalyzes the elongation of fatty acids (FAs), modulating lipid composition, and is required for normal bodily functions. However, the involvement of elongases in RCC remains unclear. In the present study, the expression of ELOVL2 in ccRCC was examined; in particular, high levels of seven ELOVL isozymes were observed in primary tumors. Of note, elevated ELOVL2 expression levels were observed in ccRCC, as well as in pRCC and chRCC. Furthermore, a higher level of ELOVL2 was significantly associated with the increased incidence of a poor prognosis of patients with ccRCC and pRCC. The CRISPR/Cas9-mediated knockdown of ELOVL2 resulted in the suppression of the elongation of long-chain polyunsaturated FAs and increased LD production in renal cancer cells. Moreover, ELOVL2 ablation resulted in the suppression of cellular proliferation via the induction of apoptosis in vitro and the attenuation of tumor growth in vivo. On the whole, the present study provides new insight into the tumor proliferation mechanisms involving lipid metabolism, and suggests that ELOVL2 may be an attractive novel target for RCC therapy.

The transcriptional corepressor CtBP2 serves as a metabolite sensor orchestrating hepatic glucose and lipid homeostasis

Biological systems to sense and respond to metabolic perturbations are critical for the maintenance of cellular homeostasis. Here we describe a hepatic system in this context orchestrated by the transcriptional corepressor C-terminal binding protein 2 (CtBP2) that harbors metabolite-sensing capabilities. The repressor activity of CtBP2 is reciprocally regulated by NADH and acyl-CoAs. CtBP2 represses Forkhead box O1 (FoxO1)-mediated hepatic gluconeogenesis directly as well as Sterol Regulatory Element-Binding Protein 1 (SREBP1)-mediated lipogenesis indirectly. The activity of CtBP2 is markedly defective in obese liver reflecting the metabolic perturbations. Thus, liver-specific CtBP2 deletion promotes hepatic gluconeogenesis and accelerates the progression of steatohepatitis. Conversely, activation of CtBP2 ameliorates diabetes and hepatic steatosis in obesity. The structure-function relationships revealed in this study identify a critical structural domain called Rossmann fold, a metabolite-sensing pocket, that is susceptible to metabolic liabilities and potentially targetable for developing therapeutic approaches.

Protocol for rapid manipulation of mitochondrial morphology in living cells using inducible counter mitochondrial morphology (iCMM)

Disruption of mitochondrial morphology occurs during various diseases, but the biological significance is not entirely clear. Here, we describe a detailed step-by-step protocol for a chemically inducible dimerization system-based synthetic protein device, termed inducible counter mitochondrial morphology. This system allows artificial manipulation of mitochondrial morphology on a timescale of minutes in living mammalian cells. We also describe an AI-assisted imaging processing approach. For complete details on the use and execution of this protocol, please refer to Miyamoto et al., 2021.

Rapid manipulation of mitochondrial morphology in a living cell with iCMM

Engineered synthetic biomolecular devices that integrate elaborate information processing and precisely regulate living cell behavior have potential in various applications. Although devices that directly regulate key biomolecules constituting inherent biological systems exist, no devices have been developed to control intracellular membrane architecture, contributing to the spatiotemporal functions of these biomolecules. This study developed a synthetic biomolecular device, termed inducible counter mitochondrial morphology (iCMM), to manipulate mitochondrial morphology, an emerging informative property for understanding physiopathological cellular behaviors, on a minute timescale by using a chemically inducible dimerization system. Using iCMM, we determined cellular changes by altering mitochondrial morphology in an unprecedented manner. This approach serves as a platform for developing more sophisticated synthetic biomolecular devices to regulate biological systems by extending manipulation targets from conventional biomolecules to mitochondria. Furthermore, iCMM might serve as a tool for uncovering the biological significance of mitochondrial morphology in various physiopathological cellular processes.

Starvation-induced transcription factor CREBH negatively governs body growth by controlling GH signaling

cAMP responsive element-binding protein H (CREBH) is a hepatic transcription factor to be activated during fasting. We generated CREBH knock-in flox mice, and then generated liver-specific CREBH transgenic (CREBH L-Tg) mice in an active form. CREBH L-Tg mice showed a delay in growth in the postnatal stage. Plasma growth hormone (GH) levels were significantly increased in CREBH L-Tg mice, but plasma insulin-like growth factor 1 (IGF1) levels were significantly decreased, indicating GH resistance. In addition, CREBH overexpression significantly increased hepatic mRNA and plasma levels of FGF21, which is thought to be as one of the causes of growth delay. However, the additional ablation of FGF21 in CREBH L-Tg mice could not correct GH resistance at all. CREBH L-Tg mice sustained GH receptor (GHR) reduction and the increase of IGF binding protein 1 (IGFBP1) in the liver regardless of FGF21. As GHR is a first step in GH signaling, the reduction of GHR leads to impairment of GH signaling. These data suggest that CREBH negatively regulates growth in the postnatal growth stage via various pathways as an abundant energy response by antagonizing GH signaling.

AB0253 COMPARISON OF PHARMACODYNAMICS OF METHOTREXATE AS METHOTREXATE-POLYGLUTAMATES CONCENTRATIONS IN RHEUMATOID ARTHRITIS; INTERIM DATA EVALUATION OF MIRACLE STUDY CONDUCTED IN JAPAN, KOREA AND TAIWAN

Background:

Methotrexate (MTX) is the first-line therapy for rheumatoid arthritis (RA). The concentrations of MTX-polyglutamates (PG) in erythrocytes, an active form of MTX, are useful markers for the optimal usage of MTX in patients with RA. The concentrations of MTX-PG have been reported to be different between Japanese and Caucasians. However, the difference among Asian ethnicity remains unclear.

Objectives:

To examine MTX-PG concentrations in association with MTX dose during the first 24 weeks after the initiation of MTX for newly diagnosed RA patients in Japan, Korea and Taiwan.

Methods:

MIRACLE study is a multicenter, open-label, randomized, 48 weeks interventional study conducted in Japan, Korea and Taiwan to evaluate non-inferiority of low dose to high dose of MTX as an add-on therapy to adalimumab in 300 patients with RA who do not achieve remission after 24 weeks MTX monotherapy in stipulated dosage. In the first 24 weeks, MTX was started at 6 to 8 mg/week for newly diagnosed RA patients, and promptly escalated to the maximum tolerable dose in 12 weeks in principle. This interim data evaluation was intended to investigate the differences among countries in the relationship between MTX dose, safety and MTX-PG concentrations in erythrocytes during the first 24 weeks. The efficacy of the treatment is not included at this point.

Results:

A total of 166 patients (106 in Japan, 35 in Korea, 25 in Taiwan) were included in this interim data. The age at treatment initiation was 57.2 years old on average and female was 79.5%. The time course changes in total and individual MTX-PG levels differed in the three countries. At 24 weeks, whereas the mean total MTX-PG concentrations were comparable (112.9 nmol/L in Japan, 104.4 nmol/L in Korea, and 115.7 nmol/L in Taiwan) with a dose of MTX of 12.3 mg/week, 14.1 mg/week, and 12.2 mg/week, respectively, the individual MTX-PG concentrations were different. The MTX-PG1 and MTX-PG2 concentrations were lower in Korea than Japan and Taiwan whereas MTX-PG3, MTX-PG4 and MTX-PG5 concentrations were the highest in Korea.

Conclusion:

The distribution of short-chain and long-chain MTX-PG concentrations were various among Asian countries despite similar dose of MTX administration: NCT03505008.

Disclosure of Interests:

Hiroya Tamai: None declared, Yuko Kaneko Speakers bureau: AbbVie, Astellas, Ayumi, Bristol–Myers Squibb, Chugai, Eisai, Eli Lilly, Hisamitsu, Jansen, Kissei, Kirin, Pfizer, Sanofi, Takeda, Tanabe-Mitsubishi, and UCB., Grant/research support from: Sanofi, Hideto Kameda Speakers bureau: AbbVie, Pfizer, Consultant of: AbbVie, Grant/research support from: AbbVie, Eisai, Masataka Kuwana Speakers bureau: Astellas, Asahi Kasei Pharma, Boehringer- Ingelheim, Chugai, Eisai, Janssen, Mochida, Nippon Shinyaku, Ono Pharmaceuticals, Pfizer, Mitsubishi-Tanabe, Consultant of: Corbus, Grant/research support from: AbbVie, Asahi Kasei Pharma, Boehringer- Ingelheim, Chugai, Eisai, MBL, Nippon Shinyaku, Ono Pharmaceuticals, Mitsubishi-Tanabe, Yutaka Okano: None declared, Tomonori Ishii Speakers bureau: Chugai, Mitsubishi- Tanabe, Glaxo Smith Kline, Pfizer, Eli Lilly, Janssen, AbbVie, Eisai, Astellas, Kei Ikeda Speakers bureau: AbbVie, Eli Lilly, Novartis, Mitsubishi-Tanabe, Eisai, BMS, Grant/research support from: Mitsubishi-Tanabe, Hiroaki Taguchi: None declared, Shinji Sato: None declared, Toshiaki Miyamoto: None declared, Shintaro Hirata Speakers bureau: AbbVie, Asahi Kasei Pharma, Astellas, Ayumi, Bristol Myers Squibb, Chugai, Eisai, Eli Lilly, Janssen, Glaxo Smith Kline, Kissei, Pfizer, Sanofi, Mitsubishi- Tanabe, UCB, Paid instructor for: AbbVie, Mitsubishi- Tanabe, Consultant of: AbbVie, Eisai, Gilead, Grant/research support from: AbbVie, Chugai, Mitsubishi-Tanabe, UCB, Hidekata Yasuoka Speakers bureau: AbbVie, Asahi Kasei Pharma, Astellas, Daiichi- Sankyo, Eisai, Kissei, Takeda, Mitsubishi- Tanabe, Chugai, Novartis, Eli Lilly, Pfizer, Janssen, Sanofi, Teijin, Boehringer- Ingelheim, Bayer, Glaxo Smith Kline, Paid instructor for: AbbVie, Consultant of: AbbVie, Asahi Kasei, Grant/research support from: Mitsubishi-Tanabe, Takeda, Daiichi-Sankyo, Chugai, Bristol-Myers, MSD, Astellas, Toshihisa Kojima Speakers bureau: AbbVie, Pfizer, Eisai, Grant/research support from: AbbVie, Sung-Hwan Park: None declared, Kichul Shin: None declared, Han Joo Baek: None declared, Yun Jong Lee Grant/research support from: research fund, In Ah Choi Speakers bureau: Abbvie, Eizai, Grant/research support from: Abbvie, Eizai, Jinhyun Kim: None declared, Ping-Ning Hsu: None declared, Chang-Fu Kuo: None declared, Chun-Ming Huang Paid instructor for: AbbVie, Pfizer, Meng-Yu Weng Consultant of: AbbVie, Wan-Yu Sung: None declared, Wen-Chan Tsai: None declared, Tien-Tsai Cheng Paid instructor for: AbbVie, Grant/research support from: AbbVie, Takehiro Taninaga Shareholder of: Eisai Co., Ltd., Employee of: Eisai Co., Ltd., Masahiko Mori Shareholder of: Eisai Co., Ltd., Employee of: Eisai Co., Ltd., Hideaki Miyagishi Employee of: Eisai Co., Ltd., Yasunori Sato: None declared, Tsutomu Takeuchi Speakers bureau: Astellas, Abbvie, Daiichi Sankyo, Ayumi, Eisai, GlaxoSmithKline, Mitsubishi Tanabe, Chugai, Novartis, Eli Lilly, Pfizer, Bristol Myers Squibb, Janssen, UCB, TaishoToyama, Sanofi–Aventis, Nipponkayaku, Taiho, Gilead, Boehringer Ingelheim, Grant/research support from: Asahikasei, Astellas, Abbvie, Daiichi Sankyo, Ayumi, Eisai, Takeda, Mitsubishi Tanabe, Chugai, Eli Lilly, UCB, Sanofi–Aventis, Nipponkayaku, Boehringer Ingelheim

Heme oxygenase-1 induction by heat shock in rat hepatoma cell line is regulated by the coordinated function of HSF1, NRF2, AND BACH1

The mechanism of heme oxygenase-1 (HO-1) induction by heat shock (HS) loading remains unclear. Here, we investigated the contribution of transcription factors to HS-induced HO-1 expression, using a rat hepatoma cell line (H-4-II-E). Our results demonstrated that HS treatment resulted in a marked induction of HO-1. Immunohistochemical analysis showed a slight mismatch in the expression levels of HO-1 and HSP70 by HS among cells, suggesting a conflict between multiple induction mechanisms. We observed HS-induced nuclear localization of, not only phosphorylated HSF1, but also NRF2, which is a typical transcription factor activated by oxidative stress. HSF1 knockdown in H-4-II-E markedly reduced HO-1 induction by HS, while NRF2 knockdown resulted in a partial effect. The chromatin immunoprecipitation assay demonstrated that HS loading resulted in significant binding of HSF1 to the HSE in the promoter proximal region of HO-1 gene and another HSE located close to the MARE in the -4 kb upstream enhancer region 1, where NRF2 also bound, together with BACH1, a negative transcription factor of HO-1. These observations indicate that HO-1 induction by HS is mainly mediated by HSF1 binding to the proximal HSE. NRF2 binding to MARE by HS is predominantly suppressed by an increased binding of BACH1.

CtBP2 confers protection against oxidative stress through interactions with NRF1 and NRF2

While molecular oxygen is essential for aerobic organisms, its utilization is inseparably connected with generation of oxidative insults. To cope with the detrimental aspects, cells evolved antioxidative defense systems, and insufficient management of the oxidative insults underlies the pathogenesis of a wide range of diseases. A battery of genes for this antioxidative defense are regulated by the transcription factors nuclear factor-erythroid 2-like 1 and 2 (NRF1 and NRF2). While the regulatory steps for the activation of NRFs have been investigated with particular emphasis on nuclear translocation and proteosomal degradation, unknown redundancy may exist considering the indispensable nature of these defense systems. Here we unraveled that C-terminal binding protein 2 (CtBP2), a transcriptional cofactor with redox-sensing capability, is an obligate partner of NRFs. CtBP2 forms transcriptional complexes with NRF1 and NRF2 that is required to promote the expression of antioxidant genes in response to oxidative insults. Our findings illustrate a basis for understanding the transcriptional regulation of antioxidative defense systems that may be exploited therapeutically.

Terahertz-field-induced polar charge order in electronic-type dielectrics

Ultrafast electronic-phase change in solids by light, called photoinduced phase transition, is a central issue in the field of non-equilibrium quantum physics, which has been developed very recently. In most of those phenomena, charge or spin orders in an original phase are melted by photocarrier generations, while an ordered state is usually difficult to be created from a non-ordered state by a photoexcitation. Here, we demonstrate that a strong terahertz electric-field pulse changes a Mott insulator of an organic molecular compound in κ-(ET)₂Cu[N(CN)₂]Cl (ET = bis(ethylenedithio)tetrathiafulvalene), to a macroscopically polarized charge-order state; herein, electronic ferroelectricity is induced by the collective intermolecular charge transfers in each dimer. In contrast, in an isostructural compound, κ-(ET)₂Cu₂(CN)₃, which shows the spin-liquid state at low temperatures, a similar polar charge order is not stabilized by the same terahertz pulse. From the comparative studies of terahertz-field-induced second-harmonic-generation and reflectivity changes in the two compounds, we suggest the possibility that a coupling of charge and spin degrees of freedom would play important roles in the stabilization of polar charge order.

The features and trends of out-of-hospital cardiac arrests in Japanese working generation: long-term aspects of a prospective, nationwide, population-based registry

Background

Despite sudden cardiac death (SCD) in working generation is a crucial issue in terms of public health, social and economic significance, the long-term SCD condition in working generation is unclear.

Purpose

This study aimed to clarify the features and long-term trends of SCD in working generation from 2005 through 2016 in Japan, using a prospective, nationwide, population based out-of-hospital cardiac arrest (OHCA) registry.

Methods

We performed data analysis of the nation-wide registry in Japan who experienced OHCA during the 12 years. Working generation was defined as 20 to 69 years and we analyzed only definitive cardiogenic OHCA as an approximation of SCD.

Results

The number of definitive cardiogenic OHCA of working generation during the period was 66,214 and 31% of the events in whole population was working generation. Definitive cardiogenic OHCA in working generation in terms of both number and percentage of the population had been decreased from 6522 (0.07‰) in 2005 to 4910 (0.06‰) in 2016, bystander cardiopulmonary resuscitation (CPR) and usage of automated external defibrillator (AED) ratio increased from 32.7% in 2005 to 49.6% in 2016, and 0.3% in 2005 to 14.7% in 2016 respectively, and the survival rate after one-month improved year by year, from 12.8% in 2005 to 34.0% in 2016 (picture below). Among non-medical bystanders, CPR was most often performed by colleagues in this generation, while AED use rate by colleague was smaller, and the time from witness to initial defibrillation was significantly longer than by passerby. Good prognosis was observed in terms of one-month survival ratio and neurological outcome for those undergoing CPR by colleague and passerby compared with other bystanders. For 12 years, although the degree varies, all non-medical bystander had same tendency; bystander CPR and usage of AED ratio increased, and the survival rate after one-month and neurological outcome improved year by year.

Conclusions

Not only the number but the incidence of cardiogenic OHCA in working generation has been decreased in Japan. The positive prognosis of this generation may be related to CPR by colleagues.

Figure 1. OHCA number & 1-month survival rate

Funding Acknowledgement

Type of funding source: None

Effect of air pollution on acute heart failure hospitalization differ across specific heart failure populations

Introduction

Several report showed the association between ambient air pollution including particular matter under 2.5um (PM2.5) and increasing rate of hospitalization for heart failure. However, these report analyzed mainly cross-sectional, epidemiological data, thus the reports regarding association between vulnerability to PM2.5 and specific populations in acute heart failure (AHF) were scarce.

Purpose

1. To analyze the association between air pollution and rate of hospitalization for AHF

2. To analyze whether the vulnerability to air pollution differ between specific populations in AHF. Methods

A case-cross over analysis was conducted to 4980 consecutive patients registered for multicenter acute heart failure registry in 2017 in our city Japan. This registry enrolled patients transferred to cardiovascular care unit (80 institutions) via emergency medical services across our city area. Logistic regression analysis were conducted to estimate percentage changes in the rate of acute heart failure hospitalization associated with per 1μg/m3 PM2.5 concentration increase. We also conducted subgroup analysis for patients stratified by age, gender, comorbidities, left ventricular ejection fraction, and clinical scenario.

Results

An increase in 1 μg/m3 PM2.5 concentration corresponded to 2.9% (95% CI 1.2–4.6%) increase in AHF hospitalization. Patients with age younger than 75, without prior heart failure hospitalization, without history of hypertension, without anemia, and with reduced ejection fraction were more susceptible to increase in PM2.5 concentration (Figure).

Conclusions

Increase in PM2.5 concentration was associated with increased rate of AHF hospitalization. Effect of PM2.5 may differ across specific AHF subpopulations.

Figure 1

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): Tokyo Metropolitan Government

Prevalence of antibiotic resistance Escherichia coli isolated from Pangasius catfish (Pangasius hypophthalmus) fillet during freezing process at two factories in Mekong Delta Vietnam

Total of 261 samples of fish and environmental samples (i.e. wash water, swabs of hand/ gloves of workers, fish contact surfaces i.e. knives, cutting boards and working tables) were collected from two Pangasius processing factories (PPF1 and PPF2). A total of seventy-one (71) isolates of Escherichia coli were selected to study the prevalence of antibiotics resistance using disk agar diffusion method. Overall, it was determined that 61% (22/36) of PPF1 isolates were resistant except to colistin while 68.57% (24/35) of PPF2 isolates were resistant except kanamycin. High resistance was against ampicillin in both PPF1 and PPF2 isolates (47.22% and 42.86%), followed by cefotaxime (33.33% and 40%) respectively. Varying resistance response to all other tested antibiotics such as streptomycin, meropenem, tetracycline, sulfamethoxazole/trimethoprim and nalidixic acid was also observed among the E. coli isolates from both factories. About 50% of the multidrug resistant (3-9 antibiotics) among PPF1 were observed whereas there were 45.83% multi-drug resistant (3-7 antibiotics) among PPF2 isolates. The result from this study reflected that there was a prevalence of multi-drug resistance of E. coli isolated during the processing of Pangasius at the studied factories. Therefore, there is a need for an effective risk management assessment models and management plans from stakeholders involved in the Pangasius value chain (i.e. farmers, processors and government) to ensure the food safety of production chain

AB0350 EFFICACY OF ADDING IGURATIMOD THERAPY IN RHEUMATOID ARTHRITIS PATIENTS WHO HAD INADEQUATE RESPONSE TO BIOLOGIC DMARDS

Background:

Iguratimod (IGU) was newly approved in Japan in June 2012 and recommended by JCR guideline 2014 in the treatment of rheumatoid arthritis (RA). Although there have been efficacy of monotherapy and concomitant MTX in clinical trials, however, there have been no reports of concomitant biologic DMARDs (Bio).

Objectives:

we investigated efficacy of concomitant IGU therapy in RA patients who had inadequate response to Bio at the author’s institution.

Methods:

Subjects were 107 patients adding IGU who had inadequate response to Bio from Janually 2014 to October 2018. Previous treatment Bio. was ADA. And baseline mean concomitant MTX was 12.3 mg/week). And baseline characteristics were Mean age 53.8 years, mean duration of illness 5.5 years, corticosteroid use 9.3%(mean 3.1mg/day).

The course of DAS28, SDAI, CDAI and remission rates were analyzed.

Results:

Mean DAS28-ESR, SDAI, CDAI were significantly decreased from the initiation of IGU treatment at 24 weeks (3.1→2.3, 7.1→2.7, 6.5→2.4), at 52 weeks (2.1, 2.4, 2.0). Remission rates of DAS28-ESR, SDAI, CDAI were 69.2%, 68.2%, 70.1% at 24 weeks, 74.8%, 78.5%, 79.4% at 52 weeks. There were no side-effect that must be stopped after adding IGU.

Conclusion:

IGU might be a new RA treatment option for aiming remission in patients who had inadequate response to Bio.

References:

[1]Hara M et al: Safety and efficacy of combination therapy of iguratimod with methotrexate for patients with active rheumatoid arthritis with an inadequate response to methotrexate: an open-label extension of a randomized, double-blind, placebo-controlled trial. Mod Rheumatol. 2014; 24: 410—418.

Disclosure of Interests:

None declared

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

BACKGROUND AND AIMS

Dysfunctional hepatic lipid metabolism is a cause of nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disorder worldwide, and is closely associated with insulin resistance and type 2 diabetes. ELOVL fatty acid elongase 6 (Elovl6) is responsible for converting C16 saturated and monounsaturated fatty acids (FAs) into C18 species. We have previously shown that Elovl6 contributes to obesity-induced insulin resistance by modifying hepatic C16/C18-related FA composition.

APPROACH AND RESULTS

To define the precise molecular mechanism by which hepatic Elovl6 affects energy homeostasis and metabolic disease, we generated liver-specific Elovl6 knockout (LKO) mice. Unexpectedly, LKO mice were not protected from high-fat diet-induced insulin resistance. Instead, LKO mice exhibited higher insulin sensitivity than controls when consuming a high-sucrose diet (HSD), which induces lipogenesis. Hepatic patatin-like phospholipase domain-containing protein 3 (Pnpla3) expression was down-regulated in LKO mice, and adenoviral Pnpla3 restoration reversed the enhancement in insulin sensitivity in HSD-fed LKO mice. Lipidomic analyses showed that the hepatic ceramide(d18:1/18:0) content was lower in LKO mice, which may explain the effect on insulin sensitivity. Ceramide(d18:1/18:0) enhances protein phosphatase 2A (PP2A) activity by interfering with the binding of PP2A to inhibitor 2 of PP2A, leading to Akt dephosphorylation. Its production involves the formation of an Elovl6-ceramide synthase 4 (CerS4) complex in the endoplasmic reticulum and a Pnpla3-CerS4 complex on lipid droplets. Consistent with this, liver-specific Elovl6 deletion in ob/ob mice reduced both hepatic ceramide(d18:1/18:0) and PP2A activity and ameliorated insulin resistance.

CONCLUSIONS

Our study demonstrates the key role of hepatic Elovl6 in the regulation of the acyl-chain composition of ceramide and that C18:0-ceramide is a potent regulator of hepatic insulin signaling linked to Pnpla3-mediated NAFLD.

Difference in the antibacterial action of epigallocatechin gallate and theaflavin 3,3'-di-O-gallate on Bacillus coagulans

AIMS

To study the mechanism of the antibacterial action of tea polyphenols such as catechins and theaflavins against Bacillus coagulans, and the interaction of epigallocatechin gallate (EGCg) or theaflavin 3,3'-di-O-gallate (TFDG) with the surface of B. coagulans cells was investigated.

METHODS AND RESULTS

The antibacterial activities of EGCg and TFDG against B. coagulans cells were measured by counting of the viable cells after the mixing with each polyphenol. Bactericidal effect of TFDG was shown at the concentration of greater than or equal to 62·5 mg l^-1 ; however, at the same concentration, EGCg did not. According to the results of two dimensional (2D)-electrophoresis analysis, TFDG seemed to interact with cytoplasmic membrane proteins. The activity of the glucose transporters of the cells decreased 40% following the treatment with TFDG of 62·5 mg l^-1 ; however, this decrease was only slight in case of EGCg. This result was in accordance with the strength of their bactericidal activities.

CONCLUSION

Our results suggest that the direct interaction between membrane proteins and TFDG is an important factor in the antibacterial activity of polymerized catechins, affecting their functions and leading to cell death.

SIGNIFICANCE AND IMPACT OF THE STUDY

Tea polyphenols can effectively use the prevention of product spoilage in the food and beverage industry.

Possible Lightest Ξ Hypernucleus with Modern ΞN Interactions

Experimental evidence exists that the Ξ-nucleus interaction is attractive. We search for NNΞ and NNNΞ bound systems on the basis of the AV8 NN potential combined with either a phenomenological Nijmegen ΞN potential or a first principles HAL QCD ΞN potential. The binding energies of the three-body and four-body systems (below the d+Ξ and ^{3}H/^{3}He+Ξ thresholds, respectively) are calculated by a high precision variational approach, the Gaussian expansion method. Although the two ΞN potentials have significantly different isospin (T) and spin (S) dependence, the NNNΞ system with quantum numbers (T=0, J^{π}=1^{+}) appears to be bound (one deep for Nijmegen and one shallow for HAL QCD) below the ^{3}H/^{3}He+Ξ threshold. Experimental implications for such a state are discussed.

High-Speed SICM for the Visualization of Nanoscale Dynamic Structural Changes in Hippocampal Neurons

Dynamic reassembly of the cytoskeleton and structural changes represented by dendritic spines, cargo transport, and synapse formation are closely related to memory. However, the visualization of the nanoscale topography is challenging because of the diffraction limit of optical microscopy. Scanning ion conductance microscopy (SICM) is an effective tool for visualizing the nanoscale topography changes of the cell surface without labeling. The temporal resolution of SICM is a critical issue of live-cell time-lapse imaging. Here, we developed a new scanning method, automation region of interest (AR)-mode SICM, to select the next imaging region by predicting the location of a cell, thus improving the scanning speed of time-lapse imaging. The newly developed algorithm reduced the scanning time by half. The time-lapse images provided not only novel information about nanoscale structural changes but also quantitative information on the dendritic spine and synaptic bouton volume changes and formation process of the neural network that are closely related to memory. Furthermore, translocation of plasmalemmal precursor vesicles (ppvs), for which fluorescent labeling has not been established, were also visualized along with the rearrangement of the cytoskeleton at the growth cone.

Topological charge transport by mobile dielectric-ferroelectric domain walls

The concept of topology has been widely applied in condensed matter physics, leading to the identification of peculiar electronic states on three-dimensional (3D) surfaces or 2D lines separating topologically distinctive regions. In the systems explored so far, the topological boundaries are built-in walls; thus, their motional degrees of freedom, which potentially bring about new paradigms, have been experimentally inaccessible. Here, working with a quasi-1D organic material with a charge-transfer instability, we show that mobile neutral-ionic (dielectric-ferroelectric) domain boundaries with topological charges carry strongly 1D-confined and anomalously large electrical conduction with an energy gap much smaller than the one-particle excitation gap. This consequence is further supported by nuclear magnetic resonance detection of spin solitons, which are required for steady current of topological charges. The present observation of topological charge transport may open a new channel for broad charge transport-related phenomena such as thermoelectric effects.

P3121Cancer therapeutics-related heart failure from a cohort study using big data of electronic health record in Japan

Background

The prognosis of cancer patients has been improved partly because of the progress in cancer therapy, which increases the cancer survivors in the society. It may raise a concern regarding the development of heart failure (HF), because the anticancer agents have some serious side effects on cardiovascular system, especially in the aging society including Japan. However, the epidemiological data for the risk of HF in the cancer survivors is limited due to the lack of comprehensive dataset in the aging society. In this regard, the electronic health record (EHR), a big data, from the National Health Insurance in Japan provides a unique opportunity to obtain the suitable dataset.

Purpose

The purpose of this study was to clarify the prevalence and the risk factors of HF in cancer survivors, focusing on the impact of their age, using EHR in Japan.

Methods

We examined the EHR of 17.8 million patients, covering 14% of the total Japanese population. The EHR includes the diagnoses as coded with International Classification of Diseases, 10th revision (ICD-10), and the information for therapeutics. We extracted 159,380 patients who received anticancer agents between April 2008 to January 2017. HF patients were identified accordingto ICD-10 codes and the record for the use of therapeutic drugs for HF at least once after the HF diagnosis following the treatment with anticancer agents. We excluded the patients if they had other conditions indistinguishable from HF or if they had past history of HF before receiving anticancer agents.

Results

The mean follow-up period was 1.75 years and mean age (standard deviation) was 68.9 (11.6) years. The population over 75 years old were 37%, while males were 59.5%. There were prostate cancer (28.1%), lung cancer (13.4%), and colon cancer (12.6%)in males, and breast cancer (42.8%), colon cancer (11.5%), and lung cancer (8.6%)in females. Among them, 5,529 patients were diagnosed with HF, corresponding to the prevalence of 3.8%. The mean time form the initiation of chemotherapy to the HF onset was 1.03 year. In the Cox's proportional hazard model after the adjustments for comorbidity, HF was more prevalent in males with hazard ratio (HR) 1.07 and 95% C.I. 1.01–1.13 (p<0.05) and in those with obesity (HR 1.18, 95% C.I. 1.09–1.26, p<0.01).We divided the subjects into three age groups (younger; <65 years, intermediate; 65–74 years, older; ≥75 years). HF was more prevalent in older group than younger group (HR 1.72, 95% C.I. 1.60–1.85, p<0.01). Among the anticancer agents, doxorubicin showed HR 2.09 (95% C.I. 1.89–2.3, p<0.01), and trastuzumab showed HR 1.47 (95% C.I 1.25–1.73, p<0.01).

Conclusion

We showed that the average prevalence of HF after anticancer agentwas 3.8%. The independent risk factors for HF were older age, male, obesity, and the use of doxorubicin or trastuzumab. This study also demonstrated the usefulness of EHR in Japan, to investigate the cardiovascular risk associated with the anticancer agents.

P2622Use of intravenous vasodilators in patients hospitalized with acute heart failure: insights from Tokyo cardiovascular care unit network database

Background

Despite recommendations from clinical practice guidelines, there is scant evidence confirming the effects of vasodilators on clinical outcomes in patients with acute heart failure (AHF).

Purpose

We sought to investigate the effects of intravenous vasodilators on clinical outcomes and to identify the potential patient populations that would benefit from its use.

Methods

Data of 26 212 consecutive patients urgently hospitalized for AHF between 2009 and 2015 were extracted from a multicenter data registration system (Tokyo Cardiovascular Care Unit Network Database, including 72 institutions within the Tokyo metropolitan area in Japan). Patients who did not present with typical AHF episodes, including those without pulmonary congestion on physical and/or chest X-ray and serum B-type natriuretic peptide level <500 pg/ml, as well as those who had hypotension and/or hypoperfusion (systolic blood pressure [SBP] <100 mmHg) as dominant presentation, were excluded. Propensity scores were calculated with multiple imputation and 1:1 matching performed between patients with and without vasodilators. The primary endpoint was in-hospital mortality and the secondary endpoints were length of intensive/cardiovascular care unit (ICU/CCU) stay and hospital stay.

Results

Overall, 8 863 patients were included in the present analysis; they were predominantly male (57%) with a median age of 79 (interquartile range: 70–86) years. Compared with the group without vasodilator use, the vasodilator group had higher SBPs and heart rates and higher frequency of assisted ventilation use, but lower frequency of intravenous diuretics use. After propensity score matching, there were no significant differences in in-hospital mortality rates (7.8% vs. 8.9% in patients without vasodilators, p=0.16) or in length of ICU/CCU stay (5.8 days vs. 5.4 days, p=0.44) and hospital stay (22.7 days vs. 23.8 days, p=0.22) between the groups. However, in subgroup analyses, favorable impacts of vasodilator use on in-hospital mortality were observed among patients who had higher SBPs and among those who had no atrial fibrillation upon admission (Figure). In addition, vasodilators were likely to be more effective in AHF patients with SBP increasing; while levels below 140 mmHg of SBP appeared to be associated with an increased risk for mortality among patients treated with vasodilators compared with those without vasodilators.

Figure 1

Conclusions

In patients with AHF, vasodilator use was not universally associated with improved in-hospital outcomes; however, its effect was dependent of individual clinical presentation. Detailed phenotyping might aid tailoring of treatment strategies for patients with AHF.

Acknowledgement/Funding

the Tokyo Metropolitan Government

P1650Clinical significance of uNGAL, uKIM-1, and uL-FABP in patients with acute pulmonary edema

Introduction

Novel urinary biomarkers such as urinary neutrophil gelatinase-associated lipocalin (u-NGAL),urinary kidney injury molecule-1 (u-KIM-1), and urinary liver-type fatty acid-binding protein (uL-FABP) are proposed to be reliable markers for acute heart failure (AHF). Acute pulmonary edema (APE) is one of the vascular phenotypes of AHF, such as `vascular failure”, often with high blood pressure at admission. We aimed to investigate the differences in the clinical impact and prognostic utility of urinary biomarkers in AHF patients with and without APE.

Methods and results

This prospective observational study included 203 AHF patients (mean age: 77 years, 52% male). uL-FABP, u-NGAL, and u-KIM-1 were measured at admission and before discharge, with correction for urinary creatinine. APE was defined as acute-onset dyspnea and radiographic alveolar edema requiring non-invasive positive pressure ventilation. The primary outcome was a composite of all-cause death and AHF rehospitalization for 1 year. The median uL-FABP levels at admission were higher in APE (n=42) than in non-APE patients (n=161; 10.8 [4.5–23.7] vs. 20.7 [5.9–63.5] μg/gCr, p=0.017), whereas u-KIM-1, u-NGAL, and serum creatinine did not significantly differ between AHF patients with and without APE. The primary outcome did not differ between patients with and without APE. However, among patients with APE, Kaplan–Meier analysis showed that higher uL-FABP (≥median: 20.7 μg/gCr) was associated with adverse events (log-rank: p=0.019). After adjusting for age, sex, serum creatinine, and brain natriuretic peptide, multivariable Cox hazard analysis showed that higher uL-FABP is an independent predictor of adverse events (HR: 4.0 [1.2–18.2], p=0.023).

Conclusion

Unlike u-NGAL and u-KIM-1, uL-FABP was higher in APE patients than in non-APE patients. Further, among patients with APE, higher uL-FABP was predictive for poor prognosis.

Acknowledgement/Funding

None

Usefulness of medication instruction sheets for sharing information on cancer chemotherapy within the health care team

Patients receiving cancer chemotherapy may experience a number of potentially severe adverse drug reactions. It is crucial for all members of the health care team to monitor the effect of medicines on the patient to ensure the safety and efficacy of the chemotherapy. The present study prepared medication instruction sheets (MISs) on hematological malignancy and conducted a questionnaire survey to verify their usefulness among physicians, dentists, and nurses. MISs were prepared for 103 chemotherapy and 44 pretreatment regimens for hematopoietic stem cell transplantation in the Department of Hematology at Kyushu University Hospital. Eight questions were prepared to investigate whether MISs could help physicians, dentists, and nurses manage cancer chemotherapy more safely, effectively, and efficiently, as well as in the sharing of information. A total of 35 medical staff working in inpatient wards, including 8 physicians, 3 dentists, and 24 nurses, participated in the questionnaire survey. All of the staff responded to the questionnaire survey, which showed that the MISs were favorably accepted by the participants. There was no negative opinion on the management of chemotherapy using the MISs. The MIS was a useful tool for sharing information on cancer chemotherapy between patients and medical staff and for enabling efficient management, thereby improving the safety and efficacy of treatment.

Doublon-holon pairing mechanism via exchange interaction in two-dimensional cuprate Mott insulators

Coupling of charge and spin degrees of freedom is a critical feature of correlated electron oxides, as represented by the spin-related mechanism of a Cooper pair under high-T _c superconductivity. A doublon-holon pair generated on an antiferromagnetic spin background is also predicted to attract each other via the spin-spin interaction J, similar to a Cooper pair, while its evidence is difficult to obtain experimentally. Here, we investigate such an excitonic effect by electroreflectance spectroscopy using terahertz electric field pulses in undoped cuprates: Nd₂CuO₄, Sr₂CuO₂Cl₂, and La₂CuO₄. Analyses of the spectral changes of reflectivity under electric fields reveal that the splitting of odd-parity and even-parity excitons, a measure of doublon-holon binding energy, increases with J. This trend is reproduced by t-J-type model calculations, providing strong evidence of the spin-related doublon-holon pairing. Agreement with the calculations supports the s-wave symmetry of the doublon-holon pair in contrast to the d-wave Cooper pair in doped cuprates.