Changes and Significance of Central Carbon Metabolism before and after Metformin Treatment of Type 2 Diabetes Based on Mass Spectrometry.

BACKGROUND: An imbalance in energy metabolism serves as a causal factor for type 2 diabetes (T2D). Although metformin has been known to ameliorate the overall energy metabolism imbalance, but the direct correlation between metformin and central carbon metabolism (CCM) has not been thoroughly investigated. In this study, we employed a high-performance ion chromatography-tandem mass spectrometry (HPIC-MS/MS) technique to examine the alterations and significance of CCM both before and after metformin treatment for T2D. METHODS: We recruited 29 participants, comprising 10 individuals recently diagnosed with T2D (T2D group). Among these, 10 patients underwent a 4-6-week treatment with metformin (MET group). Additionally, we included 9 healthy subjects (CON group). Employing HPIC-MS/MS, we quantitatively analyzed 56 metabolites across 18 biologically relevant metabolic pathways associated with CCM. Univariate and multivariate statistical analyses were utilized to identify differential metabolites. Subsequently, correlation analyses and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted on the identified differential metabolites. RESULTS: We identified seven distinct metabolites in individuals with T2D (p < 0.05). Notably, cyclic 3',5'-Adenosine MonoPhosphate (AMP), Glucose 6-phosphate, L-lactic acid, Maleic acid, and Malic acid exhibited a reversal to normal levels following metformin treatment. Furthermore, Malic acid demonstrated a positive correlation with L-lactic acid (r = 0.94, p < 0.05), as did succinic acid with malic acid (r = 0.81, p < 0.05), L-lactic acid with succinic acid (r = 0.78, p < 0.05), and L-lactic acid with glucose-6-phosphate (r = 0.72, p < 0.05). These metabolites were notably enriched in pyruvate metabolism (p = 0.005), tricarboxylic acid cycle (TCA) (p = 0.007), propanoate metabolism (p = 0.007), and glycolysis or gluconeogenesis (p = 0.009), respectively. CONCLUSIONS: We employed HPIC-MS/MS to uncover alterations in CCM among individuals recently diagnosed with T2D before and after metformin treatment. The findings suggest that metformin may ameliorate the energy metabolism imbalance in T2D by reducing intermediates within the CCM pathway.

Mechanism research on the interaction regulation of Escherichia and IFN-γ for the occurrence of T2DM.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a major social and public health problem which may be induced by intestinal flora imbalance through inflammatory response, and the specific mechanism remains unclear. In this study, we aim to explore the interaction network of intestinal flora and cell inflammation in T2DM. METHODS: This a case-control study. Patients with T2DM was the case group and healthy people as control. The differences of cytokine expression levels between patients with T2DM and healthy controls were assessed by using flow cytometry. The diversity and abundance of intestinal flora were evaluated by using 16S rRNA three-generation full-length sequencing technology. RESULTS: A total of 29 patients with T2DM and 28 healthy controls were included for analysis. Compared with the healthy control group, the expression levels of plasma cytokine interleukin-2 (IL-2) (P=0.0000006), IL-6 (P=0.000193), tumor necrosis factor α (TNF-α) (P=0.016), interferon-γ (IFN-γ) (P=0.000036) and interleukin-17 (IL-17) (P=0.004) were significantly up-regulated in T2DM patients, and the abundance of Megamonas_funiformis (P=0.0016) and Escherichia (P=0.049) in the intestine were significantly increased. In contrast, the abundance of Bacteroides_stercoris (P=0.0068), Bacteroides_uniformis (P=0.033), and Phascolarctobacterium_faecium (P=0.033) were decreased in T2DM patients. Further, differentially expressed Escherichia had a positive correlation with IFN-γ (r=0.73) by Pearson correlation analysis. CONCLUSIONS: The interaction network between the intestinal bacteria Escherichia and the cytokine IFN-γ may drive inflammation in visceral adipose tissue (VAT), indicating insulin signal transduction can be inhibited in adipocytes to induce insulin resistance.

Programmed Cell Death Ligand 1-Transfected Mouse Bone Marrow Mesenchymal Stem Cells as Targeted Therapy for Rheumatoid Arthritis.

Programmed cell death 1 ligand (PD-L1) and its receptor (PD-1) are key molecules for immunoregulation and immunotherapy. PD-L1 binding PD-1 is an effective way to regulate T or B cell immunity in autoimmune diseases such as rheumatoid arthritis (RA). In our study, we overexpressed PD-L1 by constructing a recombinant of PD-L1-lentiviral vector, which was subsequently used to transfect mouse bone marrow mesenchymal stem cells (MBMMSCs) and significantly suppressed the development of collagen-induced arthritis (CIA) in DBA/1j mice. In addition, PD-L1-transfected MBMMSCs (PD-L1-MBMMSCs) ameliorated joint damage, reduced proinflammatory cytokine expression, and inhibited T and B cell activation. Furthermore, PD-L1-MBMMSCs decreased the number of dendritic cells and increased the numbers of regulatory T cells and regulatory B cells in joints of CIA mice. In conclusion, our results provided a potential therapeutic strategy for RA treatment with PD-L1-MBMMSC-targeted therapy.