Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Type 1 diabetes mellitus reduces lipoprotein lipase (LPL) activity in the heart. The diabetic phenotype of decreased LPL activity in freshly isolated cardiomyocytes persisted after overnight culture (16 h). Total cellular LPL activity was 311+/-56 nmol oleate released x h(-1) x mg(-1) cell protein in diabetic cultured cardiomyocytes compared with 661+/-81 nmol oleate released x h(-1) x mg(-1) cell protein for control cultured cells. Diabetes also resulted in lower heparin-releasable (HR) LPL activity compared with control cells (111+/-25 vs. 432+/-63 nmol x h(-1) x mg(-1) cell protein). In kinetic experiments, the reduction in total cellular LPL and HR-LPL activities in cultured cells from diabetic hearts was due to a decrease in maximal velocity, with no change in apparent Km for substrate (triolein). LPL activity in primary cultures of cardiomyocytes from control rats is stimulated by the combination of insulin (Ins) and dexamethasone (Dex). Overnight treatment of cultured cardiomyocytes from diabetic rats with Ins+Dex elicited an 84% increase in cellular LPL activity (to 572+/-65 nmol x h(-1) x mg(-1) cell protein) and a 194% increase in HR-LPL activity (to 326+/-46 nmol x h(-1) x mg(-1) cell protein). This stimulation occurred at subnanomolar concentrations of the hormones, but neither hormone was effective alone. The amount of immunoreactive LPL protein mass in cultured cardiomyocytes from diabetic hearts was unchanged by Ins+Dex treatment. Addition of oleic acid (60 microM) to the overnight culture medium inhibited the already reduced HR-LPL activity in diabetic cultured cells by 73% (to 30+/-4 nmol x h(-1) x mg(-1) cell protein). The presence of oleic acid also reduced hormone-stimulated HR-LPL activity. Increasing the glucose concentration in the culture medium to 26 mM had no effect on total cellular LPL or HR-LPL activities.
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PMID:Lipoprotein lipase activity is stimulated by insulin and dexamethasone in cardiomyocytes from diabetic rats. 1054 20

Diabetic lipaemia, severe hypertriglyceridaemia associated with diabetic ketoacidosis, is a well recognised, but rare condition. Why this occurs in some patients and not others is unknown. We report a case of extreme lipaemia in a 20-year-old woman with type 1 diabetes who presented to hospital with diabetic ketoacidosis (DKA). At admission the patient's blood was grossly lipaemic and plasma lipid analyses showed triglyceride and cholesterol concentrations of 379 mmol/L and 52 mmol/L, respectively. She had no peripheral stigmata of chronic hyperlipidaemia and 1 year previously her plasma triglyceride and total cholesterol concentrations were 2.5 mmol/L and 4.4 mmol/L respectively. She was treated with insulin and the hypertriglyceridaemia resolved over several days. Because of the marked hypertriglyceridaemia, lipoprotein lipase (LPL) genetic testing was performed. Sequencing of the LPL gene revealed that she was heterozygous for the common S447X LPL variant and heterozygous for a novel missense mutation in exon five (I225N). Ile(225) is highly conserved among species and this mutation is predicted to impair function of the mature LPL protein. We conclude that heterozygosity for LPL mutations may predispose to transient severe hypertriglyceridaemia, when combined with insulin deficiency.
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PMID:Extreme diabetic lipaemia associated with a novel lipoprotein lipase gene mutation. 1944