Renal cystic diseases (RCDs) can arise from utero to early adulthood and present with a variety of symptoms including renal, hepatic, and cardiovascular manifestations. It is well known that common RCDs such as autosomal polycystic kidney disease and autosomal recessive kidney disease are linked to genes such as PKD1 and PKHD1, respectively. However, it is important to investigate the genetic pathophysiology of how these gene mutations lead to clinical symptoms and include some of the less-studied RCDs, such as autosomal dominant tubulointerstitial kidney disease, multicystic dysplastic kidney, Zellweger syndrome, calyceal diverticula, and more. We plan to take a thorough look into the genetic involvement and clinical sequalae of a number of RCDs with the goal of helping to guide diagnosis, counseling, and treatment.

miRNAs are small endogenous conserved non-coding RNA molecules that regulate post-transcriptional gene expression through mRNA degradation or translational inhibition, modulating nearly 60% of human genes. Cystic diseases are characterized by the presence of abnormal fluid-filled sacs in the body, and though most cysts are benign, they can grow inside tumors and turn malignant. Recent evidence has revealed that the aberrant expression of a number of miRNAs present in extracellular fluids, including plasma or serum, urine, saliva, follicular fluid, and semen, contribute to different cystic pathologies. This review aims to describe the role of different miRNAs in three worldwide relevant cystic diseases: polycystic ovarian syndrome (PCOS), polycystic kidney disease (PKD), and pancreatic cyst tumors (PCTs), as well as their potential use as novel biomarkers.

BACKGROUND: Reports about exercise performance in autosomal dominant polycystic kidney disease (ADPKD) are scarce. We aimed to evaluate exercise capacity and levels of nitric oxide and asymmetric dimethylarginine (ADMA) in normotensive patients with ADPKD.
METHODS: Prospective controlled cohort study.
METHODS: 26 patients with ADPKD and 30 non-ADPKD control participants (estimated glomerular filtration rate>60 mL/min/1.73 m2, aged 19-39 years, and blood pressure [BP]<140/85 mmHg). We excluded smokers, obese people, and individuals with associated diseases.
METHODS: ADPKD versus control.
RESULTS: Exercise capacity and nitric oxide and ADMA levels in response to exercise.
METHODS: Cardiopulmonary exercise testing and serum and urinary nitric oxide, plasma ADMA, and BP levels before and after exercise.
RESULTS: Mean basal systolic and diastolic BP, estimated glomerular filtration rate, and age did not differ between the ADPKD and control groups (116±12 vs. 110±11 mmHg, 76±11 vs 71±9 mmHg, 113±17 vs. 112±9.6 mL/min/1.73 m2, and 30±8 vs. 28.9±7.3 years, respectively). Peak oxygen uptake and anaerobic threshold were significantly lower in the ADPKD group than in controls (22.2±3.3 vs. 31±4.8 mL/kg/min [P<0.001] and 743.6±221 vs. 957.4±301 L/min [P=0.01], respectively). Postexercise serum and urinary nitric oxide levels in patients with ADPKD were not significantly different from baseline (45±5.1 vs. 48.3±4.6 μmol/L and 34.7±6.5 vs. 39.8±6.8 μmol/mg of creatinine, respectively), contrasting with increased postexercise values in controls (63.1±1.9 vs. 53.9±3.1 μmol/L [P=0.01] and 61.4±10.6 vs. 38.7±5.6 μmol/mg of creatinine [P=0.01], respectively). Similarly, whereas postexercise ADMA level did not change in the ADPKD group compared to those at rest (0.47±0.04 vs. 0.45±0.02 μmol/L [P=0.6]), it decreased in controls (0.39±0.02 vs. 0.47±0.02 μmol/L [P=0.006]), as expected. A negative correlation between nitric oxide and ADMA levels after exercise was found in only the control group (r = -0.60; P<0.01).
CONCLUSIONS: Absence of measurements of flow-mediated dilatation and oxidative status.
CONCLUSIONS: We found lower aerobic capacity in young normotensive patients with ADPKD with preserved kidney function and inadequate responses of nitric oxide and ADMA levels to acute exercise, suggesting the presence of early endothelial dysfunction in this disease.