scholarly journals Hyperglycemia and advanced glycosylation end products suppress adipocyte apoE expression: implications for adipocyte triglyceride metabolism

2010 ◽  
Vol 299 (4) ◽  
pp. E615-E623 ◽  
Author(s):  
Doris Joy Espiritu ◽  
Zhi Hua Huang ◽  
Yong Zhao ◽  
Theodore Mazzone

Endogenous adipocyte apolipoprotein E (apoE) plays an important role in adipocyte lipoprotein metabolism and lipid flux. A potential role for hyperglycemia in regulating adipocyte apoE expression and triglyceride metabolism was examined. Exposure of adipocytes to high glucose or advanced glycosylation end product-BSA significantly suppressed apoE mRNA and protein levels. This suppression was significantly attenuated by antioxidants or inhibitors of the NF-κB transcription pathway. Hyperglycemia in vivo led to adipose tissue oxidant stress and significant reduction in adipose tissue and adipocyte apoE mRNA level. Incubation with antioxidant in organ culture completely reversed this suppression. Hyperglycemia also reduced adipocyte triglyceride synthesis, and this could be completely reversed by adenoviral-mediated increases in apoE. To more specifically evaluate an in vivo role for adipocyte apoE expression on organismal triglyceride distribution in vivo, WT or apoE knockout (EKO) adipose tissue was transplanted in EKO recipient mice. After 12 wk, WT adipocytes transplanted in EKO mice accumulated more triglyceride compared with transplanted EKO adipocytes. In addition, EKO recipients of WT adipose tissue had reduced hepatic triglyceride content compared with EKO recipients transplanted with EKO adipose tissue. Our results demonstrate that hyperglycemia and advanced glycosylation end products suppress the expression of adipocyte apoE in vitro and in vivo and thereby reduce adipocyte triglyceride synthesis. In vivo results using adipose tissue transplantation suggest that reduction of adipocyte apoE, and subsequent reduction of adipocyte triglyceride accumulation, could influence lipid accumulation in nonadipose tissue.

2020 ◽  
Vol 15 (1) ◽  
pp. 619-628
Author(s):  
Chen Yuan ◽  
Ya Mo ◽  
Jie Yang ◽  
Mei Zhang ◽  
Xuejun Xie

AbstractAdvanced glycosylation end products (AGEs) are harmful factors that can damage the inner blood–retinal barrier (iBRB). Rat retinal microvascular endothelial cells (RMECs) were isolated and cultured, and identified by anti-CD31 and von Willebrand factor polyclonal antibodies. Similarly, rat retinal Müller glial cells (RMGCs) were identified by H&E staining and with antibodies of glial fibrillary acidic protein and glutamine synthetase. The transepithelial electrical resistance (TEER) value was measured with a Millicell electrical resistance system to observe the leakage of the barrier. Transwell cell plates for co-culturing RMECs with RMGCs were used to construct an iBRB model, which was then tested with the addition of AGEs at final concentrations of 50 and 100 mg/L for 24, 48, and 72 h. AGEs in the in vitro iBRB model constructed by RMEC and RMGC co-culture led to the imbalance of the vascular endothelial growth factor (VEGF) and pigment epithelial derivative factor (PEDF), and the permeability of the RMEC layer increased because the TEER decreased in a dose- and time-dependent manner. AGEs increased VEGF but lowered PEDF in a dose- and time-dependent manner. The intervention with AGEs led to the change of the transendothelial resistance of the RMEC layer likely caused by the increased ratio of VEGF/PEDF.


1991 ◽  
Vol 325 (12) ◽  
pp. 836-842 ◽  
Author(s):  
Zenji Makita ◽  
Steven Radoff ◽  
Elliot J. Rayfield ◽  
Zhi Yang ◽  
Edward Skolnik ◽  
...  

1995 ◽  
Vol 48 (1) ◽  
pp. 111-117 ◽  
Author(s):  
Douglas C. Throckmorton ◽  
Anne P. Brogden ◽  
Brian Min ◽  
Howard Rasmussen ◽  
Michael Kashgarian

2010 ◽  
pp. P2-575-P2-575
Author(s):  
CV Quintanilla-Garcia ◽  
ME Garay-Sevilla ◽  
G Barbosa-Sabanero ◽  
K Wrobel-Zasada ◽  
C Rodriguez-Flores ◽  
...  

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