Pancreatic cancer is characterized as a disease with low survival and high mortality because of no effective diagnostic and therapeutic strategies available in clinic. Conventional clinical diagnostic methods including serum markers and radiological imaging (CT, MRI, EUS, etc.) often fail to detect precancerous or early stage lesions.
View Article and Find Full Text PDFMetabolic reprogramming is implicated in macrophage activation, but the underlying mechanisms are poorly understood. Here, we demonstrate that the NOTCH1 pathway dictates activation of M1 phenotypes in isolated mouse hepatic macrophages (HMacs) and in a murine macrophage cell line by coupling transcriptional upregulation of M1 genes with metabolic upregulation of mitochondrial oxidative phosphorylation and ROS (mtROS) to augment induction of M1 genes. Enhanced mitochondrial glucose oxidation was achieved by increased recruitment of the NOTCH1 intracellular domain (NICD1) to nuclear and mitochondrial genes that encode respiratory chain components and by NOTCH-dependent induction of pyruvate dehydrogenase phosphatase 1 (Pdp1) expression, pyruvate dehydrogenase activity, and glucose flux to the TCA cycle.
View Article and Find Full Text PDFEnhanced de novo lipogenesis (DNL), an adult hepatic adaption, is seen with high carbohydrate or low-fat diets. We hypothesized that ad libitum intake after prenatal calorie restriction will result in adult-onset glucose intolerance and enhanced DNL with modified lipid metabolic gene expression profile. Stable isotopes were used in 15-month-old adult male rat offspring exposed to prenatal (IUGR), pre- and postnatal (IPGR), or postnatal (PNGR) caloric restriction vs.
View Article and Find Full Text PDFPrenatally administered rosiglitazone (RGZ) is effective in enhancing lung maturity; however, its long-term safety remains unknown. This study aimed to determine the effects of prenatally administered RGZ on the metabolic phenotype of adult rats. Methods.
View Article and Find Full Text PDFObjective: To describe the uncommon presentation of hyperinsulinism in an 8-year-old boy.
Methods: We describe the patient's clinical findings, results from biochemical and imaging studies, surgical approach, and outcome. The discussion encompasses a review of literature that provided the basis for the diagnostic and surgical approach applied to this patient's case.
The importance of PDHK (pyruvate dehydrogenase kinase) 2 and 4 in regulation of the PDH complex (pyruvate dehydrogenase complex) was assessed in single- and double-knockout mice. PDHK2 deficiency caused higher PDH complex activity and lower blood glucose levels in the fed, but not the fasted, state. PDHK4 deficiency caused similar effects, but only after fasting.
View Article and Find Full Text PDFBackground: Rosiglitazone (RGZ), a peroxisome proliferator-activated receptor-γ (PPARγ) agonist, significantly enhances lung maturation without affecting blood biochemical and metabolic profiles in the newborn period. However, whether this exposure to RGZ in neonatal life alters the adult metabolic phenotype is not known.
Objective: To determine the effects of early postnatal administration of RGZ on the young adult metabolic phenotype.
Cardiolipin (CL) is a unique phospholipid (PL) found in the mitochondria of mammalian cells. CL remodeling is accompanied by turnover of its fatty acid acyl groups. Abnormalities in CL remodeling have been found in Barth's syndrome, diabetes, and obesity.
View Article and Find Full Text PDFObjective: The impact of increased fructose consumption on carbohydrate metabolism is a topic of current interest, but determination of serum level has been hindered due to low concentration and interference from serum glucose. We are reporting a method for the quantification of glucose and fructose in clinical samples using gas chromatography/mass spectrometry (GC/MS). The accuracy and precision of GC/MS and an enzymatic assay were compared.
View Article and Find Full Text PDFPatients with traumatic brain injury (TBI) routinely exhibit cerebral glucose uptake in excess of that expected by the low levels of oxygen consumption and lactate production. This brings into question the metabolic fate of glucose. Prior studies have shown increased flux through the pentose phosphate cycle (PPC) during cellular stress.
View Article and Find Full Text PDFFatty liver is a common feature of both obesity and lipodystrophy, reflecting compromised adipose tissue function. The lipin-deficient fatty liver dystrophy (fld) mouse is an exception, as there is lipodystrophy without a fatty liver. Using a combination of indirect calorimetry and stable-isotope flux phenotyping, we determined that fld mice exhibit abnormal fuel utilization throughout the diurnal cycle, with increased glucose oxidation near the end of the fasting period and increased fatty acid oxidation during the feeding period.
View Article and Find Full Text PDFDespite altered regulation of insulin signaling, Pten(+/-) heterodeficient standard diet-fed mice, approximately 4 months old, exhibit normal fasting glucose and insulin levels. We report here a stable isotope flux phenotyping study of this "silent" phenotype, in which tissue-specific insulin effects in whole-body Pten(+/-)-deficient mice were dissected in vivo. Flux phenotyping showed gain of function in Pten(+/-) mice, seen as increased peripheral glucose disposal, and compensation by a metabolic feedback mechanism that 1) decreases hepatic glucose recycling via suppression of glucokinase expression in the basal state to preserve hepatic glucose production and 2) increases hepatic responsiveness in the fasted-to-fed transition.
View Article and Find Full Text PDFAm J Physiol Endocrinol Metab
June 2006
We studied glucose metabolic adaptations in the intrauterine growth-restricted (IUGR) rat offspring to decipher glucose homeostasis in metabolic programming. Glucose futile cycling (GFC), which is altered when there is imbalance between glucose production and utilization, was studied during a glucose tolerance test (GTT) in 2-day-old (n = 8), 2-mo-old (n = 22), and 15-mo-old (n = 22) female rat offspring. The IUGR rats exposed to either prenatal (CM/SP, n = 5 per age), postnatal (SM/CP, n = 6), or pre- and postnatal (SM/SP, n = 6) nutrient restriction were compared with age-matched controls (CM/CP, n = 5).
View Article and Find Full Text PDFJPEN J Parenter Enteral Nutr
September 2005
Background: Low-birth-weight (LBW) infants have high energy requirements and are dependent on high fat intake to maintain adequate postnatal growth. Fat energy is transported in plasma as triglycerides, which are either derived from the diet or from de novo lipogenesis (DNL). It is our hypothesis that DNL plays an important physiologic role in adapting to exclusive breast milk (EBM) feeding or to parenteral nutrition (PN).
View Article and Find Full Text PDFRecent studies in metabolic profiling have underscored the importance of the concept of a metabolic network of pathways with special functional characteristics that differ from those of simple reaction sequences. The characterization of metabolic functions requires the simultaneous measurement of substrate fluxes of interconnecting pathways. Here we present a novel stable isotope method by which the forward and reverse fluxes of the futile cycles of the hepatic glucose metabolic network are simultaneously determined.
View Article and Find Full Text PDFOur previous work led to the hypothesis that peroxisomal proliferator-activated receptor alpha (PPAR alpha) modulates insulin action in a compensatory fashion for hepatic glucose balance vs. peripheral glucose disposal. Therefore, we have examined the expression of insulin-dependent gluconeogenic/glycolytic/pentose cycle enzymes and compared these to insulin responsiveness for peripheral vs.
View Article and Find Full Text PDFIncreased glucose cycling between glucose and glucose-6-phosphate is characteristic of insulin resistance and hyperglycemia seen with Type II diabetes. Traditionally, glucose cycling is determined by the difference between hepatic glucose output measured with separate [2-3H]glucose and [6-3H]glucose infusions. We demonstrate a novel method for determining hepatic glucose recycling from an intraperitoneal glucose tolerance test (IPGTT).
View Article and Find Full Text PDFThe hypoglycemia seen in the fasting PPARalpha null mouse is thought to be due to impaired liver fatty acid beta-oxidation. The etiology of hypoglycemia in the PPARalpha null mouse was determined via stable isotope studies. Glucose, lactate, and glycerol flux was assessed in the fasted and fed states in 4-month-old PPARalpha null mice and in C57BL/6 WT maintained on standard chow using a new protocol for flux assessment in the fasted and fed states.
View Article and Find Full Text PDFAm J Physiol Endocrinol Metab
March 2002
De novo lipogenesis and dietary fat uptake are two major sources of fatty acid deposits in fat of obese animals. To determine the relative contribution of fatty acids from these two sources in obesity, we have determined the distribution of c16 and c18 fatty acids of triglycerides in plasma, liver, and epididymal fat pad of Zucker diabetic fatty (ZDF) rats and their lean littermates (ZL) under two isocaloric dietary fat conditions. Lipogenesis was also determined using the deuterated water method.
View Article and Find Full Text PDFAm J Physiol Endocrinol Metab
February 2002
Among the many tracer methods to indirectly estimate gluconeogenesis in humans, the [U-(13)C(6)]glucose method as proposed by Tayek and Katz (Am J Physiol Endocrinol Metab 270: E709-E717, 1996; Am J Physiol Endocrinol Metab 272: E476-E484, 1997) has the advantage of being able to simultaneously estimate hepatic glucose output and fractional gluconeogenesis. However, Landau et al. (Landau BR, J Wahren, K Ekberg, SF Previs, D Yang, and H Brunengraber.
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