Janet L. Dehoff-Sparks, Ph.D.

Janet L. Dehoff-Sparks, Ph.D.

Contact Information

University of Rochester Medical Center
School of Medicine and Dentistry
601 Elmwood Ave, Bpx 626
Rochester, NY 14642

Office: (585) 275-7755
Fax: (585) 756-5337

Research Bio

Plasma lipoproteins are the major vehicles for non-aqueous transport of lipids, including cholesterol and triglyceride, and lipid-soluble vitamins such as vitamin A and E, from the liver and intestine to tissues. Derangements in lipoprotein metabolism are involved in progression of atherosclerosis, an underlying cause of heart disease and strokes which remain the major cause of death in the United States. Insulin, known as a key regulator in carbohydrate metabolism, plays a major regulatory role in hepatic lipoprotein metabolism. Insulin acts by inhibition of secretion of triglyceride-rich lipoproteins through a mechanism involving the stimulation of the intracellular degradation of apolipoprotein B, an essential structural apolipoprotein.

Research in my laboratory links specific events involved in insulin receptor (IR) signal transduction with microsomal events that lead to degradation of apo B. The focus is on insulin-activated phosphatidylinositide 3-kinase (PI-3-kinase) in the translocation of apo B and its intracellular transport within the secretory pathway. Investigations employ primary rat hepatocytes, McArdle RH-7777 rat hepatoma cells and HepG2 cells and assay of IR signaling, Beta-subunit phosphorylation, IRS phosphorylation, PI 3-K activation and of PI 3-K mass in subcellular fractions. Progress will allow better understanding of insulin regulation of triglyceride-rich lipoprotein secretion by liver and will provide insights into the mechanisms involved in the development of hypertriglyceridemia in human obesity and insulin resistance syndromes such as metabolic Syndrome X which increase the risk of atherosclerosis complications up to ten times.

Recent Journal Articles

Showing the 5 most recent journal articles. 70 available »

2016 Jan 8
Sparks JD, Magra AL, Chamberlain JM, O'Dell C, Sparks CE. "Insulin dependent apolipoprotein B degradation and phosphatidylinositide 3-kinase activation with microsomal translocation are restored in McArdle RH7777 cells following serum deprivation." Biochemical and biophysical research communications. 2016 Jan 8; 469(2):326-31. Epub 2015 Nov 23.
2014 Oct
Yu IC, Lin HY, Sparks JD, Yeh S, Chang C. "Androgen receptor roles in insulin resistance and obesity in males: the linkage of androgen-deprivation therapy to metabolic syndrome." Diabetes. 2014 Oct; 63(10):3180-8.
2014 Jun
Huang CK, Pang H, Wang L, Niu Y, Luo J, Chang E, Sparks JD, Lee SO, Chang C. "New therapy via targeting androgen receptor in monocytes/macrophages to battle atherosclerosis." Hypertension. 2014 Jun; 63(6):1345-53. Epub 2014 Mar 31.
2014 Jun
Sparks CE, Corsetti JP, Sparks JD. "High-density lipoproteins: taking the good with the bad." Current opinion in lipidology. 2014 Jun; 25(3):230-2.
Greene MW, Burrington CM, Lynch DT, Davenport SK, Johnson AK, Horsman MJ, Chowdhry S, Zhang J, Sparks JD, Tirrell PC. "Lipid metabolism, oxidative stress and cell death are regulated by PKC delta in a dietary model of nonalcoholic steatohepatitis." PloS one. 2014 9(1):e85848. Epub 2014 Jan 15.

Current Appointments

Professor (Part-Time) - Department of Pathology and Laboratory Medicine (SMD) - Primary


PhD | Pathology | Univ of Pennsylvania1980
BA | Biology | Univ of Pennsylvania1972
BS | Medical Technology | Univ of Pennsylvania1972

Post-Doctoral Training & Residency

Post-doctoral Fellow Laboratory of Dr. David Kritchevsky Wistar Institute of Anatomy and Biology Philadelphia, PA 1982