Vascular endothelial growth factors and risk of cardio-renal events: Results from the CREDENCE trial.

BACKGROUND: Circulating concentrations of vascular endothelial growth factor (VEGF) family members may be abnormally elevated in type 2 diabetes (T2D). The roles of placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFLT-1), and VEGF-A in cardio-renal complications of T2D are not established. METHOD: The 2602 individuals with diabetic kidney disease (DKD) from the Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation trial were randomized to receive canagliflozin or placebo and followed for incident cardio-renal outcomes. PlGF, sFLT-1, and VEGF-A were measured at baseline, year 1, and year 3. Primary outcome was a composite of end-stage kidney disease, doubling of the serum creatinine, or renal/cardiovascular death. Cox proportional hazard regression was used to investigate the association between biomarkers with adverse clinical events. RESULTS: At baseline, individuals with higher PlGF levels had more prevalent cardiovascular disease compared to those with lower values. Treatment with canagliflozin did not meaningfully change PlGF, sFLT-1, and VEGF-A concentrations at years 1 and 3. In a multivariable model, 1 unit increases in baseline log PlGF (hazard ratio [HR]: 1.76, 95% confidence interval [CI]: 1.23, 2.54, P-value = .002), sFLT-1 (HR: 3.34, [95% CI: 1.71, 6.52], P-value < .001), and PlGF/sFLT-1 ratio (HR: 4.83, [95% CI: 0.86, 27.01], P-value = .07) were associated with primary composite outcome, while 1 unit increase in log VEGF-A did not increase the risk of primary outcome (HR: 0.96 [95% CI: 0.81, 1.07]). Change by 1 year of each biomarker was also assessed: HR (95% CI) of primary composite outcome was 2.45 (1.70, 3.54) for 1 unit increase in 1-year concentration of log PlGF, 4.19 (2.18, 8.03) for 1 unit increase in 1-year concentration of log sFLT-1, and 21.08 (3.79, 117.4) for 1 unit increase in 1-year concentration of log PlGF/sFLT-1. Increase in 1-year concentrations of log VEGF-A was not associated with primary composite outcome (HR: 1.08, [95% CI: 0.93, 1.24], P-value = .30). CONCLUSIONS: People with T2D and DKD with elevated levels of PlGF, sFLT-1, and PlGF/sFLT-1 ratio were at a higher risk for cardiorenal events. Canagliflozin did not meaningfully decrease concentrations of PlGF, sFLT-1, and VEGF-A. CLINICAL TRIAL: CREDENCE, https://clinicaltrials.gov/ct2/show/NCT02065791.

Extraction of high quality and high yield RNA from frozen EDTA blood.

Peripheral blood RNA profiling, which can reveal systemic changes in gene expression and immune responses to disease onset and progression, is a powerful tool for diagnosis and biomarker discovery. This technique usually requires high quality RNA, which is only obtainable from fresh blood, or frozen blood that has been collected in special RNA-stabilisation systems. The current study aimed to develop a novel protocol to extract high quality RNA from frozen blood that had been collected in the conventional EDTA tubes. We determined that thawing EDTA blood in the presence of cell lysis/RNA stabilisation buffers (Paxgene or Nucleospin) significantly improved RNA quality (RIN) from below 5 to above 7, which to date has not been shown possible. The EDTA-Nucleospin protocol resulted in 5 times higher yield than the EDTA-Paxgene-PreAnalytix method. The average RIN and mRNA expression levels of five different genes including 18 s, ACTB, MCP1, TNFa and TXNIP using this protocol were also indifferent to those from Paxgene blood, suggesting similar RNA quality and blood transcriptome. Moreover, the protocol allows DNA to be extracted simultaneously. In conclusion, we have developed a practical and efficient protocol to extract high quality, high yield RNA from frozen EDTA blood.

Kidney outcomes are altered by preconception weight modulation in rodent mothers with obesity.

Obesity increases the risk of chronic kidney disease. We have previously demonstrated the benefits of preconception maternal weight loss on fertility and pregnancy outcomes in a mouse model of maternal obesity. Here, we elucidate if preconception weight loss, either by diet modification or the glucose-like peptide 1 agonist liraglutide, used in the treatment of diabetes and obesity, improves maternal kidney outcomes in late gestation. C57BL/6 female mice were fed either a high-fat-diet (HFD) or a chow (control) diet for 8 weeks. To induce pre-pregnancy weight loss, HFD-fed dams were switched to chow diet (HFD-C) or administered liraglutide (0.3 mg/kg subcutaneous) whilst continuing on HFD (HFD-L). Liraglutide was discontinued one week prior to mating. HFD-V mice continued on HFD, with saline injections. A group of HFD-fed dams were 'diet switched' to chow after conception (post-conception, HFD-PC). Maternal body weight and glucose tolerance were measured: (1) preconception and (2) during late gestation followed by blood, urine and kidney collection. Serum creatinine, urinary creatinine and albumin, kidney tissue gene expression and protein were measured. In the preconception period, HFD-L and HFD-C mothers have lower urine albumin:creatinine ratios (UACR) and fatty acid synthase (FAS) protein expression (P < 0.005 vs. HFD-V). At late gestation, kidneys of HFD-V and HFD-PC dams have increased gene expression of insulin receptor and FAS (P < 0.05) and higher UACR compared to controls (P < 0.01). In the HFD-PC group, kidneys show increased mRNA and protein expression of metabolic and oxidative stress markers (FAS, 8-OHdG vs. control, P < 0.05, P < 0.0001 respectively). The preconception intervention groups with liraglutide, or diet change show reduced oxidative stress (protein expression of 8-OHdG, P < 0.05 vs. HFD), mRNA and protein expression of FAS (P < 0.05 vs. HFD), protein expression of fibrosis markers (collagen IV, fibronectin vs. HFD, P < 0.05), and UACR (P < 0.05 vs. HFD). This study suggests that preconception weight loss benefits maternal kidney health during pregnancy, superior to diet intervention once already pregnant.

Associations of Angiopoietin 2 and Vascular Endothelial Growth Factor-A Concentrations with Clinical End Points.

BACKGROUND: Angiopoietin 2 regulates endothelial function partially mediated by vascular endothelial growth factor-A (VEGF-A) and may play a role in diabetic kidney disease (DKD). We assessed the association of angiopoietin 2 and VEGF-A with cardiorenal outcomes and investigated the effect of canagliflozin on angiopoietin 2 and VEGF-A concentrations. METHODS: Two thousand five hundred sixty-five study participants with DKD and available plasma samples treated with canagliflozin or placebo in the Canagliflozin and Kidney Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) trial were included. Angiopoietin 2 and VEGF-A concentrations were measured at baseline, year 1, and year 3. The primary composite end point of the trial was a composite of kidney failure, doubling of the serum creatinine level, and kidney or cardiovascular death. RESULTS: Patients with the highest baseline quartile of angiopoietin 2, but not VEGF-A, concentration had the highest risk clinical profile. Treatment with canagliflozin significantly lowered concentrations of angiopoietin 2 (adjusted geometric mean ratio: 0.94; 95% confidence interval, 0.92 to 0.95; P < 0.001), but not VEGF-A. In multivariable-adjusted modeling, each 50% increment in log baseline angiopoietin 2 concentrations was associated with a higher risk of primary composite outcome (hazard ratio, 1.27; 95% confidence interval, 1.13 to 1.43). Angiopoietin 2 change at year 1 compared with baseline explained 10% of the effect of canagliflozin on the primary composite outcome. VEGF-A concentrations were not associated with outcomes, alone or in combination with angiopoietin 2. CONCLUSIONS: Higher angiopoietin 2 levels were associated with cardiorenal risk among individuals with DKD independent of VEGF-A. Canagliflozin lowered angiopoietin 2 concentrations. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Evaluation of the Effects of Canagliflozin on Renal and Cardiovascular Outcomes in Participants With Diabetic Nephropathy, NCT02065791 .

Maternal Weight Intervention in the Perinatal Period Improves Liver Health in the Offspring of Mothers with Obesity.

Early-life exposure to maternal obesity predisposes offspring to metabolic-associated fatty liver disease (MAFLD). This study aimed to determine if peripartum weight loss, either through dietary intervention or pharmacological intervention, improved adverse liver health outcomes in the offspring of mothers with obesity. C57Bl/6 dams were fed a chow diet or a high-fat diet (HFD) for 8 weeks. HFD-fed mice either continued HFD, transitioned to a chow diet, or were administered liraglutide for 4 weeks. Pregnancy was induced following a one-week washout of liraglutide during which all animals remained on their respective diets. A proportion of HFD-fed mice transitioned to a chow diet during pregnancy. All offspring were weaned to the HFD. Offspring anthropometric, metabolic, and hepatic outcomes were assessed at postnatal week 12. The offspring of mothers with obesity had phenotypic changes consistent with MAFLD. The offspring of mothers that had weight loss with perinatal dietary intervention had reduced insulin resistance (p < 0.001) and hepatic expression of markers of inflammation (p < 0.001), oxidative stress (p < 0.05), and fibrosis (p < 0.05). A similar phenotype was observed in the offspring of mothers with pre-pregnancy weight loss via liraglutide despite ongoing consumption of the HFD during pregnancy. All methods and timing of maternal weight intervention were effective at ameliorating adverse liver effects in the offspring.