The ozone degradation has been proven to be an effective degradation method for alginate, while the degradation mechanism remained to be unconfirmed. In this study, two high-molecular-weight alginates with different mannuronic/guluronic (G/M) ratios, HM and HG (G/M 0.49 vs 1.40), were depolymerized using established ozonation technology platform. Notably, HM can be degraded faster than HG especially within initial 30 min, indicating that the β-1, 4-mannuronic bonds are more susceptible to be ozonated than α-1, 4-guluronic bonds. However, HM/HG degraded to LMWA in 2 h and reached a plateau. Therefore, we employed mass spectrometry (MS) to profile the degraded products of LMWA polymannuronate (PM) and polyguluronate (PG) in more intense conditions. The results indicated that the oxidation process continued until all reducing ends were converted to carboxyl groups. The o-diol could directly oxidize to o-dialdehyde. This study provides a MS based elucidation of the mechanism by which alginate cleaves to oligosaccharides through ozonation.
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http://dx.doi.org/10.1016/j.ijbiomac.2024.135306 | DOI Listing |
Diabetes
January 2025
Institute for Developmental and Regenerative Cardiovascular Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
Diabetes is a major risk factor for cardiovascular disease, but the molecular mechanisms underlying diabetic vasculopathy have been elusive. Here we report that inositol hexakisphosphate kinase 1 (IP6K1) mediates hyperglycemia-induced endothelial senescence by rewiring the liver kinase B1 (LKB1) signaling from activating the adenosine monophosphate-activated protein kinase (AMPK) pathway to the p53 pathway. We found that hyperglycemia upregulated IP6K1, which disrupts the Hsp/Hsc70 and carboxyl terminus of Hsc70-interacting protein (CHIP)-mediated LKB1 degradation, leading to increased expression levels of LKB1.
View Article and Find Full Text PDFJ Assist Reprod Genet
January 2025
Department of Obstetrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China.
Pregnancy complications pose challenges for both pregnant women and obstetricians globally, with the pathogenesis of many remaining poorly understood. Recently coined as a mode of cell death, cuproptosis has been proposed but remains largely unexplored. This process involves copper overload, resulting in the accumulation of fatty acylated proteins and subsequent loss of iron-sulfur cluster proteins.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Key Laboratory of Medical Molecular Virology (Ministry of Education / National Health Commission / Chinese Academy of Medical Sciences), Shanghai Frontiers Science Center of Pathogenic Microorganisms and Infection, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai 200033, China.
Sialic acids derived from colonic mucin glycans are crucial nutrients for enteric bacterial pathogens like . The uptake and utilization of sialic acid in depend on coordinated regulons, each activated by specific metabolites at the transcriptional level. However, the mechanisms enabling crosstalk among these regulatory circuits to synchronize gene expression remain poorly understood.
View Article and Find Full Text PDFCurr Cardiol Rep
January 2025
Department of Zoology, Trivenidevi Bhalotia College (Affiliated to Kazi Nazrul University), College Para Rd, Raniganj, 713347, West Bengal, India.
Purpose Of Review: This review investigates how post-injury cellular signaling and energy metabolism are two pivotal points in zebrafish's cardiomyocyte cell cycle re-entry and proliferation. It seeks to highlight the probable mechanism of action in proliferative cardiomyocytes compared to mammals and identify gaps in the current understanding of metabolic regulation of cardiac regeneration.
Recent Findings: Metabolic substrate changes after birth correlate with reduced cardiomyocyte proliferation in mammals.
J Asian Nat Prod Res
January 2025
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences/Peking Union Medical College, Beijing 100050, China.
Angoroside C (AgrC) is a compound with many pharmacological properties. However, its antitumour potential has not been well studied. The low bioavailability of AgrC suggests a strong link to gut bacteria.
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