scholarly journals Metformin: an old drug with potential therapeutic function in antitumor

2021 ◽  
Author(s):  
wei mu ◽  
Yunyun Jiang ◽  
Falin Qu
Keyword(s):  
Hepatic Glucose Production ◽  
Reactive Oxygen Species Generation ◽  
Chain Complex ◽  
Glucose Production ◽  
Mitochondrial Respiratory Chain ◽  
Underlying Mechanism ◽  
Antitumor Therapy ◽  
Peripheral Tissues ◽  
Mitochondrial Respiratory Chain Complex ◽  
Key Factor

Metformin is one of the first-line and widely-used drugs in patients with T2DM due to its safety profile, clinical efficacy and cheap cost. It is clearly that metformin has benefits on lowering hyperglycemia and diabetes-related complications in clinical use. The classic effect of metformin is to reduce hepatic glucose production by inhibiting gluconeogenesis in liver and increase glucose utilization in peripheral tissues. Metformin targets mitochondrial respiratory chain complex I to specifically reduce reactive oxygen species generation to protect cells against oxidative stress-induced cell apoptosis. AMPK complex is a key factor in the action of metformin; however it is inconclusive that whether metformin activate AMPK directly or indirectly. In addition, more and more studies showed that metformin act on gut microbiota to exert anti-hyperglycemia effect. Emerging evidence showed that metformin has off-label function on antitumor therapy; however the underlying mechanism of this property of metformin still remains elusive. Taken together, in this review we provide a new perspective on metformin and repurpose its novel and promising application in antitumor therapy.

scholarly journals Regulation of Mitochondrial Respiratory Chain Complex Levels, Organization, and Function by Arginyltransferase 1

2020 ◽  
Vol 8 ◽  
Author(s):  
Chunhua Jiang ◽  
Balaji T. Moorthy ◽  
Devang M. Patel ◽  
Akhilesh Kumar ◽  
William M. Morgan ◽  
...  
Keyword(s):  
Respiratory Chain ◽  
Chain Complex ◽  
Mitochondrial Respiratory Chain ◽  
Underlying Mechanism ◽  
Metabolic Effects ◽  
Respiratory Chain Complexes ◽  
Mitochondrial Respiratory Chain Complex ◽  
Human Disorders ◽  
And Function ◽  
Alpha Proteobacteria

Arginyltransferase 1 (ATE1) is an evolutionary-conserved eukaryotic protein that localizes to the cytosol and nucleus. It is the only known enzyme in metazoans and fungi that catalyzes posttranslational arginylation. Lack of arginylation has been linked to an array of human disorders, including cancer, by altering the response to stress and the regulation of metabolism and apoptosis. Although mitochondria play relevant roles in these processes in health and disease, a causal relationship between ATE1 activity and mitochondrial biology has yet to be established. Here, we report a phylogenetic analysis that traces the roots of ATE1 to alpha-proteobacteria, the mitochondrion microbial ancestor. We then demonstrate that a small fraction of ATE1 localizes within mitochondria. Furthermore, the absence of ATE1 influences the levels, organization, and function of respiratory chain complexes in mouse cells. Specifically, ATE1-KO mouse embryonic fibroblasts have increased levels of respiratory supercomplexes I+III2+IVn. However, they have decreased mitochondrial respiration owing to severely lowered complex II levels, which leads to accumulation of succinate and downstream metabolic effects. Taken together, our findings establish a novel pathway for mitochondrial function regulation that might explain ATE1-dependent effects in various disease conditions, including cancer and aging, in which metabolic shifts are part of the pathogenic or deleterious underlying mechanism.

scholarly journals Leptin Activates a Novel CNS Mechanism for Insulin-Independent Normalization of Severe Diabetic Hyperglycemia

Endocrinology ◽  
2010 ◽  
Vol 152 (2) ◽  
pp. 394-404 ◽  
Author(s):  
Jonathan P. German ◽  
Joshua P. Thaler ◽  
Brent E. Wisse ◽  
Shinsuke Oh-I ◽  
David A. Sarruf ◽  
...  
Keyword(s):  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Underlying Mechanism ◽  
Glucose Levels ◽  
Blood Glucose Levels ◽  
Uncontrolled Diabetes ◽  
Urinary Glucose ◽  
Hepatic Glucose ◽  
Glucose Excretion ◽  
The Brain

Abstract The brain has emerged as a target for the insulin-sensitizing effects of several hormonal and nutrient-related signals. The current studies were undertaken to investigate mechanisms whereby leptin lowers circulating blood glucose levels independently of insulin. After extending previous evidence that leptin infusion directly into the lateral cerebral ventricle ameliorates hyperglycemia in rats with streptozotocin-induced uncontrolled diabetes mellitus, we showed that the underlying mechanism is independent of changes of food intake, urinary glucose excretion, or recovery of pancreatic β-cells. Instead, leptin action in the brain potently suppresses hepatic glucose production while increasing tissue glucose uptake despite persistent, severe insulin deficiency. This leptin action is distinct from its previously reported effect to increase insulin sensitivity in the liver and offers compelling evidence that the brain has the capacity to normalize diabetic hyperglycemia in the presence of sufficient amounts of central nervous system leptin.

Dietary dimethylglycine sodium salt supplementation improves growth performance, redox status, and skeletal muscle function of intrauterine growth restriction weaned piglets

2021 ◽  
Author(s):  
Kaiwen Bai ◽  
Luyi Jiang ◽  
Qiming Li ◽  
Jingfei Zhang ◽  
Lili Zhang ◽  
...  
Keyword(s):  
Growth Performance ◽  
Mitochondrial Function ◽  
Chain Complex ◽  
Basal Diet ◽  
Mitochondrial Respiratory Chain ◽  
Redox Status ◽  
Weaned Piglets ◽  
Complex Activity ◽  
Mitochondrial Respiratory Chain Complex ◽  
Intrauterine Growth

Abstract Few studies have focused on the role of dimethylglycine sodium salt (DMG-Na) in protecting the redox status of skeletal muscle, although it is reported to be beneficial in animal husbandry. This study investigated the beneficial effects of DMG-Na on the growth performance, longissimus dorsi muscle (LM) redox status, and mitochondrial function in weaning piglets that were intrauterine growth restricted (IUGR). Ten normal birth weight (NBW) newborn piglets (1.53 ± 0.04 kg) and 20 IUGR newborn piglets (0.76 ± 0.06 kg) from ten sows were obtained. All piglets were weaned at 21 days of age and allocated to three groups with ten replicates per group: NBW-weaned piglets fed a common basal diet (N); IUGR weaned piglets fed a common basal diet (I); IUGR weaned piglets fed a common basal diet supplemented with 0.1% DMG-Na (ID). They were slaughtered at 49 days of age to collect the serum and LM samples. Compared with the N group, the growth performance, LM structure, serum, and, within the LM, mitochondrial redox status, mitochondrial respiratory chain complex activity, energy metabolites, redox status-related, cell adhesion-related, and mitochondrial function-related gene expression, and protein expression deteriorated in group I (P < 0.05). The ID group showed improved growth performance, LM structure, serum, and, within the LM, mitochondrial redox status, mitochondrial respiratory chain complex activity, energy metabolites, redox status-related, cell adhesion-related, and mitochondrial function-related gene expression, and protein expression compared with those in the I group (P < 0.05). The above results indicated that the DMG-Na treatment could improve the LM redox status and mitochondrial function in IUGR weaned piglets via the Nuclear factor erythroid 2-related factor 2 (Nrf2)/ Sirtuin 1 (SIRT1)/ Peroxisome proliferator-activated receptorγcoactivator-1α (PGC1α) network, thus improving their growth performance.

Effects of norepinephrine infusion on in vivo insulin sensitivity and responsiveness

1990 ◽  
Vol 259 (2) ◽  
pp. E210-E215 ◽  
Author(s):  
J. R. Lupien ◽  
M. F. Hirshman ◽  
E. S. Horton
Keyword(s):  
Insulin Sensitivity ◽  
Hepatic Glucose Production ◽  
Glucose Production ◽  
Glucose Disposal ◽  
Glucose Turnover ◽  
Adrenergic Blockade ◽  
Sprague Dawley ◽  
Euglycemic Hyperinsulinemic Clamp ◽  
Peripheral Tissues

The effect of a continuous infusion of norepinephrine (NE) on glucose disposal in vivo was examined in conscious restrained rats using the euglycemic-hyperinsulinemic clamp technique. NE, 1,000 micrograms.kg-1.day-1 (130 nmol.kg-1.h-1) or vehicle (CO) was infused for 10 days in adult male Sprague-Dawley rats using subcutaneously implanted osmotic minipumps. Body weight and food intake were similar in both groups of animals throughout the study. Fasting basal plasma glucose and insulin concentrations were similar in both groups. However, basal hepatic glucose production (HGP) was increased by NE treatment (9.03 +/- 0.63 vs. 13.20 +/- 1.15 mg.kg-1.min-1, P less than 0.05, CO vs. NE, respectively). Insulin infusions of 2, 6, and 200 mU.kg-1.min-1 suppressed HGP to the same degree in both groups. During 2, 6, and 200 mU.kg-1.h-1 insulin infusions the glucose disposal rate was 65, 60, and 13% greater in NE-treated animals than in controls. Acute beta-adrenergic blockade with propranolol infused at 405 nmol.kg-1.h-1 during the glucose clamps did not normalize glucose disposal. These results demonstrate that chronic NE infusion is associated with increased basal glucose turnover and increased insulin sensitivity of peripheral tissues.

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