Correlation between proteinuria and injury in kidney tubule resorption Vitamin D3 in patients with preeclampsia

• Grant number: 15/10666-1
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2015
• Effective date (End): July 31, 2017
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Humberto Dellê
• Grantee: Tania Cristina Macedo Kunz
• Home Institution: Universidade Nove de Julho (UNINOVE). Campus Vergueiro. São Paulo , SP, Brazil

Abstract

It is increasingly evident the relationship between pre-eclampsia and deficiency of vitamin D3, two major public health problems. Although it is not well known which of the clinical conditions appears first, there is evidence that one enhances the other perpetuating a cycle, especially as proteinuria, as consistent and classifier of preeclampsia, can be mitigated by replacement of vitamin D. The final activation of vitamin D occures preferably in the proximal tubule, locally, which is intensively modified when it contains a protein loading (especially albumin) over the normal value. The binding protein of vitamin D (DBP English vitamin D binding protein), should be endocytosed by the proximal tubule through the receiver system megalin / tubilina, the same system that absorbs the proteins which cross the glomerular barrier, in particular albumin. Therefore, when a patient presents 'proteinuria' due to pre-eclampsia (high blood pressure), the overload of albumin present in the tubular light can overload the endocytic system tubule as well as promote its injury, which would affect the re-absorption and activation from '25 hydroxyvitamin D', reinforcing its deficiency in the organism. Therefore, the aim of this study is to compare megalin, cubilin and DBP in the urine of pregnant woman with pre-eclampsia proteinuric, non-proteinuric hypertensive pregnant women and healthy pregnant women in order to investigate the deleterious effect of proteinuria on vitamin D absorption mechanism on the renal tubules. Project results may define a mechanism that may be responsible for triggering or enhancing vitamin D deficiency in pregnant women.