Branched-chain alpha-keto acid dehydrogenase (BCKDH) kinase (BDK) is responsible for the regulation of BCKDH complex, which is the rate-limiting enzyme in the catabolism of branched-chain amino acids (BCAAs). In the present study, we investigated the expression and activity of hepatic BDK in spontaneous type 2 diabetes using hyperinsulinemic Zucker diabetic fatty rats aged 9weeks and hyperglycemic, but not hyperinsulinemic rats aged 18weeks. The abundance of hepatic BDK mRNA and total BDK protein did not correlate with changes in serum insulin concentrations. On the other hand, the amount of BDK bound to the complex and its kinase activity were correlated with alterations in serum insulin levels, suggesting that hyperinsulinemia upregulates hepatic BDK. The activity of BDK inversely corresponded with the BCKDH complex activity, which was suppressed in hyperinsulinemic rats. These results suggest that insulin regulates BCAA catabolism in type 2 diabetic rats by modulating the hepatic BDK activity.
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http://dx.doi.org/10.1016/j.bbrc.2010.02.004 | DOI Listing |
Radiol Imaging Cancer
November 2024
From the Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, PO Box 85500, 3508 GA Utrecht, the Netherlands.
Purpose To evaluate the safety and feasibility of a novel hybrid nuclear and fluoroscopy C-arm scanner to be used during the work-up procedure of hepatic radioembolization. Materials and Methods In this prospective first-in-human clinical study, 12 participants (median age, 67 years [range: 37-78 years]; nine [75%] male, three [25%] female) with liver tumors undergoing work-up for yttrium 90 radioembolization were included (ClinicalTrials.gov NCT06013774).
View Article and Find Full Text PDFJ Nutr Sci Vitaminol (Tokyo)
January 2024
Department of Food and Nutritional Sciences, College of Bioscience and Biotechnology, Chubu University.
Branched-chain α-ketoacid dehydrogenase (BCKDH) complex is a rate-limiting enzyme in branched-chain amino acid catabolism and is subject to inactivation via phosphorylation by BCKDH kinase (BDK). In the present study, we examined the effects of vitamin D-deficiency on hepatic BCKDH and BDK activities in rats. Rats fed a vitamin D-deficient diet long-term showed a slight but significant decrease in plasma Ca concentration, which was associated with an elevation of BCKDH activity and a decrease in BDK activity.
View Article and Find Full Text PDFMol Metab
December 2022
Internal Medicine Research Unit, Pfizer Inc, Cambridge MA 02139, USA. Electronic address:
Objective: Branched chain amino acid (BCAA) catabolic defects are implicated to be causal determinates of multiple diseases. This work aimed to better understand how enhancing BCAA catabolism affected metabolic homeostasis as well as the mechanisms underlying these improvements.
Methods: The rate limiting step of BCAA catabolism is the irreversible decarboxylation by the branched chain ketoacid dehydrogenase (BCKDH) enzyme complex, which is post-translationally controlled through phosphorylation by BCKDH kinase (BDK).
N Engl J Med
August 2020
From the Center for Human Nutrition (M.Y., B.D.K., J.Y., R.I.S., D.R., K.S., B.W.P., S.K.) and the Department of Surgery (J.C.E., S.R.E.), Washington University School of Medicine, St. Louis; and the Departments of Medicine (J.D.W., M.J.), Pharmacology (J.D.W., M.J.), Pediatrics (R.K.), and Computer Science and Engineering (R.K.), University of California San Diego, San Diego.
Background: Some studies have suggested that in people with type 2 diabetes, Roux-en-Y gastric bypass has therapeutic effects on metabolic function that are independent of weight loss.
Methods: We evaluated metabolic regulators of glucose homeostasis before and after matched (approximately 18%) weight loss induced by gastric bypass (surgery group) or diet alone (diet group) in 22 patients with obesity and diabetes. The primary outcome was the change in hepatic insulin sensitivity, assessed by infusion of insulin at low rates (stages 1 and 2 of a 3-stage hyperinsulinemic euglycemic pancreatic clamp).
Cell Metab
June 2018
Sarah W. Stedman Nutrition and Metabolism Center & Duke Molecular Physiology Institute, Duke University Medical Center, 300 North Duke Street, Durham, NC 27701, USA; Departments of Medicine and Pharmacology & Cancer Biology, Durham, NC 27701, USA. Electronic address:
Branched-chain amino acids (BCAA) are strongly associated with dysregulated glucose and lipid metabolism, but the underlying mechanisms are poorly understood. We report that inhibition of the kinase (BDK) or overexpression of the phosphatase (PPM1K) that regulates branched-chain ketoacid dehydrogenase (BCKDH), the committed step of BCAA catabolism, lowers circulating BCAA, reduces hepatic steatosis, and improves glucose tolerance in the absence of weight loss in Zucker fatty rats. Phosphoproteomics analysis identified ATP-citrate lyase (ACL) as an alternate substrate of BDK and PPM1K.
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