Effects of the dual peroxisome proliferator-activated receptor-α/γ agonist aleglitazar on renal function in patients with stage 3 chronic kidney disease and type 2 diabetes: a Phase IIb, randomized study.

BACKGROUND: Type 2 diabetes is a major risk factor for chronic kidney disease, which substantially increases the risk of cardiovascular disease mortality. This Phase IIb safety study (AleNephro) in patients with stage 3 chronic kidney disease and type 2 diabetes, evaluated the renal effects of aleglitazar, a balanced peroxisome proliferator-activated receptor-α/γ agonist. METHODS: Patients were randomized to 52 weeks' double-blind treatment with aleglitazar 150 µg/day (n=150) or pioglitazone 45 mg/day (n=152), followed by an 8-week off-treatment period. The primary endpoint was non-inferiority for the difference between aleglitazar and pioglitazone in percentage change in estimated glomerular filtration rate from baseline to end of follow-up. Secondary endpoints included change from baseline in estimated glomerular filtration rate and lipid profiles at end of treatment. RESULTS: Mean estimated glomerular filtration rate change from baseline to end of follow-up was -2.7% (95% confidence interval: -7.7, 2.4) with aleglitazar versus -3.4% (95% confidence interval: -8.5, 1.7) with pioglitazone, establishing non-inferiority (0.77%; 95% confidence interval: -4.5, 6.0). Aleglitazar was associated with a 15% decrease in estimated glomerular filtration rate versus 5.4% with pioglitazone at end of treatment, which plateaued to 8 weeks and was not progressive. Superior improvements in high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides, with similar effects on glycosylated hemoglobin were observed with aleglitazar versus pioglitazone. No major safety concerns were identified. CONCLUSIONS: The primary endpoint in AleNephro was met, indicating that in stage 3 chronic kidney disease patients with type 2 diabetes, the decrease in estimated glomerular filtration rate after 52 weeks' treatment with aleglitazar followed by 8 weeks off-treatment was reversible and comparable (non-inferior) to pioglitazone. TRIAL REGISTRATION: NCT01043029 January 5, 2010.

UBA1 and UBA2, two proteins that interact with UBP1, a multifunctional effector of pre-mRNA maturation in plants.

Nicotiana plumbaginifolia UBP1 is an hnRNP-like protein associated with the poly(A)(+) RNA in the cell nucleus. Consistent with a role in pre-mRNA processing, overexpression of UBP1 in N. plumabaginifolia protoplasts enhances the splicing of suboptimal introns and increases the steady-state levels of reporter mRNAs, even intronless ones. The latter effect of UBP1 is promoter specific and appears to be due to UBP1 binding to the 3' untranslated region (3'-UTR) and protecting the mRNA from exonucleolytic degradation (M. H. L. Lambermon, G. G. Simpson, D. A. Kirk, M. Hemmings-Mieszczak, U. Klahre, and W. Filipowicz, EMBO J. 19:1638-1649, 2000). To gain more insight into UBP1 function in pre-mRNA maturation, we characterized proteins interacting with N. plumbaginifolia UBP1 and one of its Arabidopsis thaliana counterparts, AtUBP1b, by using yeast two-hybrid screens and in vitro pull-down assays. Two proteins, UBP1-associated proteins 1a and 2a (UBA1a and UBA2a, respectively), were identified in A. thaliana. They are members of two novel families of plant-specific proteins containing RNA recognition motif-type RNA-binding domains. UBA1a and UBA2a are nuclear proteins, and their recombinant forms bind RNA with a specificity for oligouridylates in vitro. As with UBP1, transient overexpression of UBA1a in protoplasts increases the steady-state levels of reporter mRNAs in a promoter-dependent manner. Similarly, overexpression of UBA2a increases the levels of reporter mRNAs, but this effect is promoter independent. Unlike UBP1, neither UBA1a nor UBA2a stimulates pre-mRNA splicing. These and other data suggest that UBP1, UBA1a, and UBA2a may act as components of a complex recognizing U-rich sequences in plant 3'-UTRs and contributing to the stabilization of mRNAs in the nucleus.

Effects of high dose aleglitazar on renal function in patients with type 2 diabetes.

BACKGROUND: Aleglitazar is a new, balanced dual peroxisome proliferator-activated receptor (PPAR)α/γ agonist designed to optimize lipid and glycemic benefits and minimize PPAR-related adverse effects. METHODS: SESTA R was a 26-week, randomized, double-blind, multicenter study comparing the effects of a supratherapeutic dosage of aleglitazar (600 µg/day) with pioglitazone (45 mg/day) on change in measured GFR (mGFR) in 174 patients with type 2 diabetes and normal to mildly impaired renal function (estimated GFR [eGFR] 60 to 120 ml/min/1.73 m(2)). RESULTS: In 118 patients with evaluable GFR measurements, baseline mean (± SD) mGFR was 97.6 ± 17.5 ml/min/1.73 m(2) in the aleglitazar group and 101.9±21.6ml/min/1.73m(2) in the pioglitazone group. Mean percent change from baseline mGFR was -16.9% (90% confidence interval -22.0 to -11.5) with aleglitazar and -4.6% (-10.15 to 1.35) with pioglitazone, a mean treatment difference of -13.0% (-19.0 to -6.5). The 17% decrease from baseline in mGFR was consistent with the 19% decrease in eGFR Modification of Diet in Renal Disease (MDRD) observed with aleglitazar, which reached a plateau after 4weeks, with no further progression until treatment discontinuation. Following aleglitazar withdrawal, eGFR values returned to pretreatment levels within the 4-8-week follow-up, which suggests reversible hemodynamic changes in renal function. CONCLUSIONS: Despite the increased incidence of expected, dose-dependent PPAR class side effects (e.g., peripheral edema, weight gain, and congestive heart failure) limiting further development of this supratherapeutic dosage of aleglitazar (600 µg/day), these data, together with the data from the dose-ranging SYNCHRONY study, suggest aleglitazar may be a potential new treatment for cardiovascular risk reduction in post-acute coronary syndrome patients at the therapeutic 150 µg daily dose.

The circadian clock regulated RNA-binding protein AtGRP7 autoregulates its expression by influencing alternative splicing of its own pre-mRNA.

The clock-regulated RNA-binding protein AtGRP7 is part of a negative feedback circuit through which the protein influences circadian oscillations of its own transcript. Constitutive overexpression of AtGRP7 in transgenic plants leads to the appearance of a low amount of an alternatively spliced Atgrp7 transcript with a premature stop codon. It is generated by the use of a 5' cryptic splice site in the middle of the intron at the expense of the fully spliced mRNA, indicating a role for AtGRP7 in splice site selection. Accelerated decay of this transcript accounts for its low steady state abundance. This implicates a mechanism for the AtGRP7 feedback loop: Atgrp7 expression is downregulated, as AtGRP7 protein accumulates over the circadian cycle, partly by the generation of an alternate transcript that due to its instability does not accumulate to high levels and does not produce a functional protein. Recombinant AtGRP7 protein specifically interacts with the 3' untranslated region and the intron of its transcript, suggesting that the shift in splice site selection and downregulation involves binding of AtGRP7 to its pre-mRNA. AtGRP7 also influences the choice of splice sites in the Atgrp8 transcript encoding a related RNA-binding protein, favoring the production of an alternatively spliced, unstable Atgrp8 transcript. This conservation points to the importance of this regulatory mechanism to control the level of the clock-regulated glycine-rich RNA-binding proteins and shows how AtGRP7 can control abundance of target transcripts.