University of Mississippi Medical Center, USA
Naznin Dixit is currently working as a Professor and Chief of Pediatric Endocrinology and Diabetes at the University of Mississippi Medical Center, department of Pediatrics and Director of Pediatric Endocrinology Clinical Services at Batson Children’s Hospital. She has almost 30 years of worldwide training and experience in USA, Australia and India managing children with diabetes and various endocrine disorders.
Aim: Life expectancy of an obese smoker is 13 years less than a normal weight smoker, which could be linked to the increased renal risk imposed by smoking. Both smoking-through Nicotine (NIC)-and obesity-by free fatty acid overload-provoke oxidative stress in the kidney, which ultimately results in development of chronic kidney injury. Their combined renal risk, however, is virtually unknown. The hypothesis that chronic NIC exposure worsens renal oxidative stress in mice on High-Fat Diet (HFD) by altering the balance between expression of pro-oxidant and antioxidant genes is tested.
Methods: Nine-week-old male C57Bl/6J mice consumed Normal Diet (ND) or HFD and received either NIC (200 μg/ml) or vehicle (2% saccharine) in their drinking water. Body weight, plasma clinical parameters, renal lipid deposition, markers of renal oxidative stress and injury, as well as renal expression of the pro-oxidant p66shc and the antioxidant MnSOD were determined after 12 weeks.
Results: NIC significantly augmented levels of circulating free fatty acid, as well as lipid deposition, oxidative stress and sublethal injury in the kidneys of mice on HFD. In addition, NIC exposure suppressed HFD-mediated induction of MnSOD while increased expression of p66shc in the kidney.
Conclusion: Tobacco smoking or the increasingly popular E-cigarettes-via NIC exposure-could worsen obesity-associated lipotoxicity in the kidney. Hence, the findings could help to develop strategies that mitigate adverse effects of NIC on the obese kidney.