Background: Microalbuminuria is an early sign of kidney disease in diabetes and indicates cardiovascular risk. We tested if a prespecified urinary proteomic risk classifier (CKD273) was associated with development of microalbuminuria and if progression to microalbuminuria could be prevented with the mineralocorticoid receptor antagonist spironolactone. Methods: Prospective multicentre study in people with type 2 diabetes, normal urinary albumin excretion and preserved renal function in 15 European specialist centres. High-risk individuals determined by CKD273 were randomised 1:1 (interactive web response system) in a double-blind randomised controlled trial comparing spironolactone 25 mg o.d. to placebo. Primary endpoint was development of confirmed microalbuminuria in all individuals with available data. Secondary endpoints included reduction in incidence of microalbuminuria with spironolactone and association between CKD273 and impaired renal function defined as a glomerular filtration rate < 60 ml/min per 1•73 m 2. This study is registered with ClinicalTrials.gov: NCT02040441 and is completed. Findings: From March 25, 2014 to September 30, 2018 we followed 1775 participants, 12% (n=216) had high-risk urinary proteomic pattern of which 209 were included in the trial and assigned spironolactone (n=102) or placebo (n=107). Median follow-up time was 2•51 years (IQR 2•0-3•0). Progression to microalbuminuria was seen in 28•2% of high-risk and 8•9% of low-risk people (P< 0•001) (hazard ratio (HR), 2•48; 95% confidence interval [CI], 1•80 to 3•42 P<0•001, independent of baseline clinical characteristics). A 30% decline in eGFR from baseline was seen in 42 (19•4 %) high-risk participants compared to 62 (3•9 %) low-risk participants, HR 5•15; 95 % CI (3•41 to 7•76; p<0.0001). Development of microalbuminuria was seen in 35 (33%) randomised to placebo and 26 (25%) randomised to spironolactone treatment (HR 0•81, 95% CI, 0•49 to 1•34, P=0•41). Harms: hyperkalaemia was seen in 13 versus 4, and gynaecomastia in 3 versus 0 subjects on spironolactone and placebo, respectively. Interpretation: In people with type 2 diabetes and normoalbuminuria, the urinary proteomic classifier CKD273 was associated with a 2•5 times increased risk for progression to microalbuminuria over a median of 2•5 years, independent of clinical characteristics. Spironolactone did not prevent progression to microalbuminuria in high-risk subjects.

Activation of peroxisome proliferator-activated receptor gamma (PPARgamma) has been found to induce cell death in a variety of cells. In this regard, we reported recently that 15-deoxy-Delta-(12,14)-prostaglandin J2 (15dPG-J2), a specific ligand of the nuclear receptor PPARgamma, inhibits proliferation and induces cellular differentiation and apoptosis in the breast cancer cell line MCF-7. In addition to PPARgamma activation other proteins, such as NF-kappaB and AP1, have been shown to be targets of 15dPG-J2. However, the mechanism by which 15dPG-J2 triggers cell death is still elusive. Our results demonstrate that 15dPG-J2 initiates breast cancer cell death via a very rapid and severe impairment of mitochondrial function, as revealed by a drop in mitochondrial membrane potential (DeltaPsi(m)), generation of reactive oxygen species (ROS) and a decrease in oxygen consumption. In addition, 15dPG-J2 can also activate an intrinsic apoptotic pathway involving phosphatidyl serine externalization, caspase activation and cytochrome c release. Bcl-2 over-expression and zVADfmk, albeit preventing caspase activation, have no effect on 15dPG-J2-mediated mytochondrial dysfunction and loss of cell viability. In contrast, the addition of radical scavengers or rotenone, which prevent 15dPG-J2-induced ROS production, block the loss of cell viability induced by this prostaglandin. Finally, 15dPG-J2-induced cell death appears to involve disruption of the microtubule cytoskeletal network. Together, these results suggest that PG-J2-induced mitochondrial dysfunction and ROS production inevitably leads to death, with or without caspases.

No abstract