beta cell dysfunction is a central component of the pathogenesis of type 2 diabetes. Using oligonucleotide microarrays and real-time PCR of pancreatic islets isolated from humans with type 2 diabetes versus normal glucose-tolerant controls, we identified multiple changes in expression of genes known to be important in beta cell function, including major decreases in expression of HNF4alpha, insulin receptor, IRS2, Akt2, and several glucose-metabolic-pathway genes. There was also a 90% decrease in expression of the transcription factor ARNT. Reducing ARNT levels in Min6 cells with small interfering RNA (siRNA) resulted in markedly impaired glucose-stimulated insulin release and changes in gene expression similar to those in human type 2 islets. Likewise, beta cell-specific ARNT knockout mice exhibited abnormal glucose tolerance, impaired insulin secretion, and changes in islet gene expression that mimicked those in human diabetic islets. Together, these data suggest an important role for decreased ARNT and altered gene expression in the impaired islet function of human type 2 diabetes.
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http://dx.doi.org/10.1016/j.cell.2005.05.027 | DOI Listing |
Chemosphere
January 2025
Research Unit in Environmental and Evolutionary Biology (URBE), Institute of Life Earth and Environment, University of Namur, 61 Rue de Bruxelles, B-5000, Namur, Belgium.
ZnO and TiO nanoparticles (NPs) are widely employed for their antibacterial properties, but their potential environmental impact is raising concerns. This study aimed to assess their single and combined effects at environmentally relevant concentrations (210 μg L) on rainbow trout (Oncorhynchus mykiss) gills microbiota and immune functions. 16S rRNA gene sequencing performed after 5 and 28 days of exposure suggests that TiO NPs had a more immediate impact on bacterial diversity, while prolonged exposure to the mixture altered community composition.
View Article and Find Full Text PDFJ Exp Bot
January 2025
National Institute of Science and Technology on Plant Physiology under Stress Conditions, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa 36570-900, Minas Gerais, Brazil.
The transport of metabolites across the inner mitochondrial membrane (IMM) is crucial for maintaining energy balance and efficient distribution of metabolic intermediates between cellular compartments. Under abiotic stress, mitochondrial function becomes particularly critical, activating complex signaling pathways essential for plant stress responses. These pathways modulate stress-responsive gene expression, influencing key physiological processes such as cell respiration and senescence, helping plants adapt to stress.
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January 2025
Ministry of Education Key Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, China; Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Zhejiang Provincial Key Laboratory of Pancreatic Disease, School of Medicine, Zhejiang University, Hangzhou, China; Cancer Center, Zhejiang University, Hangzhou, China. Electronic address:
Arginine methylation is a common post-translational modification that plays critical roles in many biological processes. However, the existence of arginine demethylases that remove the modification has not been fully established. Here, we report that Myc-induced nuclear antigen 53 (Mina53), a member of the jumonji C (JmjC) protein family, is an arginine demethylase.
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January 2025
Division of Cell Regulation, Center for Experimental Medicine and Systems Biology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; Division of Cell Engineering, Center for Stem Cell Biology and Regenerative Medicine, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; Laboratory for Stem Cell Therapy, Faculty of Medicine, Tsukuba University, Ibaraki, Japan. Electronic address:
Hematopoietic stem cells (HSCs) possess the capacity to regenerate the entire hematopoietic system. However, the precise HSC dynamics in the early post-transplantation phase remain an enigma. Clinically, the initial hematopoiesis in the post-transplantation period is critical, necessitating strategies to accelerate hematopoietic recovery.
View Article and Find Full Text PDFJ Plant Res
January 2025
College of Marine and Biological Engineering, Yancheng Institute of Technology, Yancheng, 224002, Jiangsu, China.
Barley (Hordeum vulgare L.) is an important cereal crop used in animal feed, beer brewing, and food production. Waterlogging stress is one of the prominent abiotic stresses that has a significant impact on the yield and quality of barley.
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