Endothelial-specific deletion of connexin 43 improves renal function and structure after acute kidney injury.

Background: We have previously reported that the gap junction protein connexin 43 (Cx43) was upregulated in chronic renal disease in humans and rodents and plays a crucial role in the progression of experimental nephropathy. In this study, we investigated its role after renal ischemia/reperfusion (rIR), which is a major mechanism of injury in acute renal injury (AKI) and renal transplant graft dysfunction.

Methods: Wild-type mice (WT) and mice in which Cx43 expression was genetically reduced by half (Cx43 ±) were unilaterally nephrectomized.

The Mineralocorticoid Receptor on Smooth Muscle Cells Promotes Tacrolimus-Induced Renal Injury in Mice.

Tacrolimus (Tac) is a calcineurin inhibitor commonly used as an immunosuppressor after solid organ transplantation. However, Tac may induce hypertension, nephrotoxicity, and an increase in aldosterone levels. The activation of the mineralocorticoid receptor (MR) is related to the proinflammatory status at the renal level.

α-Ketoglutarate Upregulates Collecting Duct (Pro)renin Receptor Expression, Tubular Angiotensin II Formation, and Na Reabsorption During High Glucose Conditions.

Diabetes mellitus (DM) causes high glucose (HG) levels in the plasma and urine. The (pro)renin receptor (PRR) is a key regulator of renal Na handling. PRR is expressed in intercalated (IC) cells of the collecting duct (CD) and binds renin to promote angiotensin (Ang) II formation, thereby contributing to Na reabsorption.

Oxidized Albumin as a Mediator of Kidney Disease.

Renal diseases are a global health concern, and nearly 24% of kidney disease patients are overweight or obese. Particularly, increased body mass index has been correlated with oxidative stress and urinary albumin excretion in kidney disease patients, also contributing to increased cardiovascular risk. Albumin is the main plasma protein and is able to partially cross the glomerular filtration barrier, being reabsorbed mainly by the proximal tubule through different mechanisms.

The Role of Neutrophils in Hypertension.

It is well accepted that the immune system and some cells from adaptive and innate immunity are necessary for the initiation/perpetuation of arterial hypertension (AH). However, whether neutrophils are part of this group remains debatable. There is evidence showing that the neutrophil/lymphocyte ratio correlates with AH and is higher in non-dipper patients.

Upregulation of Cortical Renin and Downregulation of Medullary (Pro)Renin Receptor in Unilateral Ureteral Obstruction.

Chronic kidney disease (CKD) is characterized by renal dysfunction, which is a common feature of other major diseases, such as hypertension and diabetes. Unilateral ureteral obstruction (UUO) has been used as a model of CKD in experimental animals and consists of total obstruction of one kidney ureter. The UUO decreases renal blood flow, which promotes the synthesis of renin in the juxtaglomerular apparatus, the first step in renin-angiotensin system (RAS) cascade.

Dendritic cells are crucial for cardiovascular remodeling and modulate neutrophil gelatinase-associated lipocalin expression upon mineralocorticoid receptor activation.

Background: Adaptive immunity is crucial in cardiovascular and renal inflammation/fibrosis upon hyperactivation of mineralocorticoid receptor. We have previously demonstrated that dendritic cells can respond to mineralocorticoid receptor activation, and the neutrophil gelatinase-associated lipocalin (NGAL) in dendritic cells is highly increased during aldosterone (Aldo)/mineralocorticoid receptor-dependent cardiovascular damage. However, the interrelationship among dendritic cells, target organs inflammation/fibrosis induced by mineralocorticoid receptor, and NGAL-dependence remains unknown.

(Pro)renin receptor activation increases profibrotic markers and fibroblast-like phenotype through MAPK-dependent ROS formation in mouse renal collecting duct cells.

Recent studies suggested that activation of the PRR upregulates profibrotic markers through reactive oxygen species (ROS) formation; however, the exact mechanisms have not been investigated in CD cells. We hypothesized that activation of the PRR increases the expression of profibrotic markers through MAPK-dependent ROS formation in CD cells. Mouse renal CD cell line (M-1) was treated with recombinant prorenin plus ROS or MAPK inhibitors and PRR-shRNA to evaluate their effect on the expression of profibrotic markers.