Placental and serum levels of human α-Klotho in preeclampsia & intra-uterine growth retardation: A potential sensitive biomarker?

INTRODUCTION: α-Klotho protein has three isoforms: a transmembrane (mKL), a shed- soluble isoform, and a circulating soluble isoform (sKL). mKL is expressed in the kidney and placenta, while sKL is detectable in blood and urine. It is known that α-Klotho levels fluctuate during pregnancy mainly in women with complications such as preeclampsia (PE) and intra-uterine growth restriction (IUGR). METHODS: Forty-nine participants were divided into two groups: healthy and complicated pregnancy (PE, IUGR or both). Tissue samples (2 cm3) from the maternal side, Blood and urine samples were collected during pregnancy and postpartum. Samples were subjected to biochemical (WB), histological (H&E and IHC) staining as well as genetic analysis (qPCR). RESULTS: Blood αKL levels were preserved in both healthy and complicated pregnancies. Significantly lower blood αKL concentrations were found in PE postpartum (PP) compared to levels during pregnancy, and were significantly lower compared with postpartum of a healthy pregnancy. αKL activity was reduced in complicated pregnancies vs. healthy pregnancies. Placen tal mKL levels (ELISA) and expression (WB) were lowered in complicated pregnancies compared with the healthy pregnancies group. Additionally, we found a significant decline in the expression of mKL mRNA in PE/IUGR placentas compared with the healthy group. DISCUSSION: Several studies have focused on the involvement of αKL in normal placentation during pregnancy. Our results suggest lower function of sKL in complicated pregnancy compared with a control, and present differences in placental mKL levels as well as tissue and gene expression between healthy and complicated pregnancy. In light of our results, we conclude that complicated pregnancy is associated with in decline in mKL.

The Molecular Effects of SGLT2i Empagliflozin on the Autophagy Pathway in Diabetes Mellitus Type 2 and Its Complications.

Background: Type 2 diabetes mellitus (T2DM), especially hyperglycemia, is associated with increased glucose cell toxicity and oxidative stress that can lead to irreversible damage in the kidney such as diabetic nephropathy (DN). Autophagy plays a key role in the degradation of damaged intracellular proteins in order to maintain intracellular homeostasis and cell integrity. The disturbance of autophagy is involved in the pathogenesis of diabetic nephropathy. We aim to investigate the molecular effect of sodium-glucose transporter 2 inhibitor (SGLT2i) on the expression of ATG5 and its downstream collaborator LC3-II in diabetic nice model. Material and Methods. We used eight weeks old male mice: twenty C57BL/6 wild type (C57BL/6), twenty BTBR ob/ob (DM), and twenty BTBR ob/ob that were treated with empagliflozin (DM+EMPA), FDA approved SGLT2i. Lysate from murine renal cortex was analyzed by Western blot and immunohistochemistry. ATG5, LC3B, and fibronectin expression were analyzed in murine kidney tissues. All mice were sacrificed 13 weeks after the beginning of the experiment. Results: Histological and Western blot analyses reveal decrease ATG5, LC3-II, and fibronectin levels at renal specimens taken from DM mice. EMPA treatment reduced T2DM mice body weight and blood glucose and increased urine glucose. Further, it upregulated all of the abovementioned proteins. Conclusions: Hyperglycemia reduces LC3-II and ATG5 protein levels which contribute to deficiencies in the autophagy process, with development and progression of DN. SGLT2i significantly reduces progression of DN and onset of end-stage renal disease in T2DM patients, probably through its effect on autophagy.

Vitamin E and diabetic nephropathy in mice model and humans.

Diabetes mellitus (DM) is associated with increased oxidative stress due to elevated glucose levels in the plasma. Glucose promotes glycosylation of both plasma and cellular proteins with increased risk for vascular events. Diabetic patients suffer from a higher incidence of cardiovascular complications such as diabetic nephropathy. Haptoglobin (Hp) is an antioxidant plasma protein which binds free hemoglobin, thus preventing heme-iron mediated oxidation. Two alleles exist at the Hp gene locus (1 and 2) encoding three possible Hp genotypes that differ in their antioxidant ability, and may respond differently to vitamin E treatment. Several clinical studies to have shown that Hp 1-1 genotype is a superior antioxidant to the Hp 2-2 genotype and Hp 2-2 genotype is associated with a higher incidence of cardiovascular disease. Vitamin E was found to have beneficial effect in patient and mice with Hp 2-2 genotype. In this review we have summarized the results of our studies in patients with diabetic nephropathy treated with vitamin E and in diabetic mice with different haptoglobin genotypes.