134 results match your criteria: "Graduate School of Biological Science[Affiliation]"

4S-fluorination of ProB29 in insulin lispro slows fibril formation.

J Biol Chem

June 2024

Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA. Electronic address:

Recombinant insulin is a life-saving therapeutic for millions of patients affected by diabetes mellitus. Standard mutagenesis has led to insulin variants with improved control of blood glucose; for instance, the fast-acting insulin lispro contains two point mutations that suppress dimer formation and expedite absorption. However, insulins undergo irreversible denaturation, a process accelerated for the insulin monomer.

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  • - The study focuses on the role of Methyltransferase 16 (METTL16) in liver cancer stem cells (CSCs), revealing its significant involvement in the development and maintenance of hepatocellular carcinoma (HCC) while having a lesser effect on normal liver development.
  • - Using various experimental models, the researchers found that depleting METTL16 reduced CSC frequency and hindered HCC initiation and progression, indicating METTL16's essential role in cancer biology.
  • - The research highlights METTL16 as a key regulator of ribosomal RNA maturation and mRNA translation, identifying eIF3a as a target, providing insights for potential therapeutic developments against liver cancer.
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  • CagA is an oncoprotein that disrupts gastric epithelial cells and promotes inflammation, contributing to atrophic gastritis, a precursor to gastric cancer.
  • There is limited research on single nucleotide polymorphisms (SNPs) in autophagy-related genes and their connection to atrophic gastritis.
  • This study analyzed SNP frequencies in 200 subjects, identifying a significant association between specific genotypes and gastric mucosal atrophy, which could help identify patients at risk for gastric cancer who may need early intervention.
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  • Mammalian gut microbes adapt to the intestinal environment and their composition is heavily influenced by the host's diet, which can alter nutrient profiles in the intestine.* -
  • Genetic mutations in a specific gut microbe species enhance their fitness in the intestinal tract, and this research discovered important mutations related to sugar metabolism soon after colonization in mice.* -
  • The study highlights that not only do these genetic changes improve the microbe's ability to use nutrients from the diet, but the host's diet also affects which mutations occur, shedding light on the adaptation mechanisms of gut bacteria.*
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Analogs of proline can be used to expand the chemical space about the residue while maintaining its uniquely restricted conformational space. Here, we demonstrate the incorporation of 4-methylproline, 4-methylproline, and 4-methyleneproline into recombinant insulin expressed in . These modified proline residues, introduced at position B28, change the biophysical properties of insulin: Incorporation of 4-methyleneproline at B28 accelerates fibril formation, while 4-methylation speeds dissociation from the pharmaceutically formulated hexamer.

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CYP8B1 downregulation mediates the metabolic effects of vertical sleeve gastrectomy in mice.

Hepatology

May 2024

Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope National Medical Center, Duarte, California, USA.

Background And Aims: Although the benefits of vertical sleeve gastrectomy (VSG) surgery are well known, the molecular mechanisms by which VSG alleviates obesity and its complications remain unclear. We aim to determine the role of CYP8B1 (cytochrome P450, family 8, subfamily B, polypeptide 1) in mediating the metabolic benefits of VSG.

Approach And Results: We found that expression of CYP8B1, a key enzyme in controlling the 12α-hydroxylated (12α-OH) bile acid (BA) to non-12α-OH BA ratio, was strongly downregulated after VSG.

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Plants synthesize specialized metabolites to facilitate environmental and ecological interactions. During evolution, plants diversified in their potential to synthesize these metabolites. Quantitative differences in metabolite levels of natural Arabidopsis (Arabidopsis thaliana) accessions can be employed to unravel the genetic basis for metabolic traits using genome-wide association studies (GWAS).

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  • Infection leads to atrophic gastritis, which can progress to gastric cancer, with CagA being a key virulence factor injected into gastric cells.
  • This study focused on identifying specific single nucleotide polymorphisms (SNPs) related to gastric mucosal atrophy (GMA) among 200 H. pylori-positive participants without gastric cancer.
  • Four SNPs were linked to GMA, particularly the G/G genotype of rs6431659, which showed a significant association, indicating a need for further research with larger sample sizes.
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This study investigated the effects of different multiple low doses of streptozotocin (STZ), namely 35 and 55 mg/kg, on the onset and progression of diabetes in mice. Both doses are commonly used in research, and although both induced a loss of beta cell mass, they had distinct effects on whole glucose tolerance, beta cell function, and gene transcription. Mice treated with 55 mg/kg became rapidly glucose intolerant, whereas those treated with 35 mg/kg had a slower onset and remained glucose tolerant for up to a week before becoming equally glucose intolerant as the 55 mg/kg group.

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This study investigated the effects of different multiple low doses of streptozotocin (STZ), namely 35 and 55 mg/kg, on the onset and progression of diabetes in mice. Both doses are commonly used in research, and while both induced a loss of beta cell mass, they had distinct effects on whole glucose tolerance, beta cell function and gene transcription. Mice treated with 55 mg/kg became rapidly glucose intolerant, whereas those treated with 35 mg/kg had a slower onset and remained glucose tolerant for up to a week before becoming equally glucose intolerant as the 55 mg/kg group.

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Downregulation of hepatic lncRNA Gm19619 improves gluconeogenesis and lipogenesis following vertical sleeve gastrectomy in mice.

Commun Biol

January 2023

Department of Diabetes Complications and Metabolism, Arthur Riggs-Diabetes and Metabolism Research Institute, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA, 91010, USA.

Long non-coding RNAs (lncRNAs) are emerging important epigenetic regulators in metabolic processes. Whether they contribute to the metabolic effects of vertical sleeve gastrectomy (VSG), one of the most effective treatments for sustainable weight loss and metabolic improvement, is unknown. Herein, we identify a hepatic lncRNA Gm19619, which is strongly repressed by VSG but highly up-regulated by diet-induced obesity and overnight-fasting in mice.

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Recent advances in single cell RNA sequencing (scRNA-seq) technologies have been invaluable in the study of the diversity of cancer cells and the tumor microenvironment. While scRNA-seq platforms allow processing of a high number of cells, uneven read quality and technical artifacts hinder the ability to identify and classify biologically relevant cells into correct subtypes. This obstructs the analysis of cancer and normal cell diversity, while rare and low expression cell populations may be lost by setting arbitrary high cutoffs for UMIs when filtering out low quality cells.

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Introduction: Hermaphroditism is a mode of reproduction involving an individual animal that possesses both a testis and an ovary either sequentially or simultaneously. The mechanism creating hermaphrodites remains unknown. Previously, we identified foxl3 as the germline sex determination gene in a gonochoristic fish, medaka (Oryzias latipes).

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Ethylene glycol metabolism in the poly(ethylene terephthalate)-degrading bacterium Ideonella sakaiensis.

Appl Microbiol Biotechnol

December 2022

Institute for Research Initiatives, Division for Research Strategy, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan.

Poly(ethylene terephthalate) (PET)-degrading bacterium Ideonella sakaiensis produces hydrolytic enzymes that convert PET, via mono(2-hydroxyethyl) terephthalate (MHET), into the monomeric compounds, terephthalic acid (TPA), and ethylene glycol (EG). Understanding PET metabolism is critical if this bacterium is to be engineered for bioremediation and biorecycling. TPA uptake and catabolism in I.

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Fusarium species include important filamentous fungal pathogens that can infect plants, animals, and humans. Meanwhile, some nonpathogenic Fusarium species are promising biocontrol agents against plant pathogens. Here, we developed a genome editing technology using a vector-based CRISPR/Cas9 system for Fusarium oxysporum f.

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A miRNA-mediated attenuation of hepatocarcinogenesis in both hepatocytes and Kupffer cells.

Mol Ther Nucleic Acids

December 2022

Department of Diabetes Complications and Metabolism, Arthur Riggs Diabetes and Metabolism Research Institute, Beckman Research Institute, City of Hope National Medical Center, 1500 E. Duarte Road, Duarte, CA 91010, USA.

MicroRNAs (miRNAs) are small noncoding RNAs that regulate a variety of physiological and pathological functions. miR-26a is one of the many miRNAs that have been identified as regulators of cancer development and as potential anticancer drug targets. However, the specific cellular and molecular mechanisms by which miR-26a attenuates hepatocarcinogenesis are still elusive.

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Medical Radiation Exposure Reduction in PET via Super-Resolution Deep Learning Model.

Diagnostics (Basel)

March 2022

Department of Biomedical Science and Engineering, Faculty of Health Sciences, Hokkaido University, Sapporo 060-0812, Japan.

In positron emission tomography (PET) imaging, image quality correlates with the injected [18F]-fluorodeoxyglucose (FDG) dose and acquisition time. If image quality improves from short-acquisition PET images via the super-resolution (SR) deep learning technique, it is possible to reduce the injected FDG dose. Therefore, the aim of this study was to clarify whether the SR deep learning technique could improve the image quality of the 50%-acquisition-time image to the level of that of the 100%-acquisition-time image.

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In monocarpic plants, stem cells are fated to die. However, the potential mechanism of stem cell death has remained elusive. Here, we reveal that the levels of two forms of reactive oxygen species (ROS), superoxide anion free radical (O2·-) and hydrogen peroxide (HO), show dynamic changes in the shoot apex during the plant life cycle of .

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Intestinal AMPK modulation of microbiota mediates crosstalk with brown fat to control thermogenesis.

Nat Commun

March 2022

Department of Diabetes Complications & Metabolism, Arthur Riggs Diabetes and Metabolism Research Institute, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA, USA.

The energy-dissipating capacity of brown adipose tissue through thermogenesis can be targeted to improve energy balance. Mammalian 5'-AMP-activated protein kinase, a key nutrient sensor for maintaining cellular energy status, is a known therapeutic target in Type II diabetes. Despite its well-established roles in regulating glucose metabolism in various tissues, the functions of AMPK in the intestine remain largely unexplored.

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The -methylation of specialized metabolites in plants is a unique decoration that provides structural and functional diversity of the metabolites with changes in chemical properties and intracellular localizations. The -methylation of flavonoids, which is a class of plant specialized metabolites, promotes their antimicrobial activities and liposolubility. Flavonoid -methyltransferases (FOMTs), which are responsible for the -methylation process of the flavonoid aglycone, generally accept a broad range of substrates across flavones, flavonols and lignin precursors, with different substrate preferences.

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Article Synopsis
  • METTL16 is identified as an RNA methyltransferase that deposits N-methyladenosine (mA) in some messenger RNA transcripts, but its broader role in methylating various transcripts like METTL3 and METTL14 is still uncertain.
  • The research shows that METTL16 has both methyltransferase activity-dependent and -independent functions, particularly in gene regulation, acting as an mA writer in the nucleus and promoting translation in the cytosol without relying on mA.
  • METTL16 interacts directly with initiation factors and ribosomal RNA to enhance translation, impacting over 4,000 mRNA transcripts, and is crucial for the development of hepatocellular carcinoma, highlighting its important dual functions in both methyl
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Genetic modification in plants helps us to understand molecular mechanisms underlying on plant fitness and to improve profitable crops. However, in transgenic plants, the value of gene expression often varies among plant populations of distinct lines and among generations of identical individuals. This variation is caused by several reasons, such as differences in the chromosome position, repeated sequences, and copy number of the inserted transgene.

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Bile Acid-Mediated Activation of Brown Fat Protects From Alcohol-Induced Steatosis and Liver Injury in Mice.

Cell Mol Gastroenterol Hepatol

April 2022

Department of Diabetes Complications and Metabolism, Duarte, California; Graduate School of Biological Science, Beckman Research Institute, City of Hope National Medical Center, Duarte, California. Electronic address:

Background & Aims: Alcohol-associated liver disease (AALD) is one of the most common causes of liver injury and failure. Limited knowledge of the mechanisms underlying AALD impedes the development of efficacious therapies. Bile acid (BA) signaling was shown to participate in the progression of AALD.

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