Background: The need for an improved treatment for diabetic nephropathy is greatest in patients who do not adequately respond to angiotensin II receptor blockers (ARBs). This study investigated the effect of the novel dipeptidyl peptidase-4 inhibitor linagliptin alone and in combination with the ARB telmisartan on the progression of diabetic nephropathy in diabetic endothelial nitric oxide synthase (eNOS) knockout mice. Methods: Sixty male eNOS knockout C57BL/6J mice were divided into four groups after receiving intraperitoneal highdose streptozotocin: telmisartan (1 mg/kg), linagliptin (3 mg/kg), linagliptin + telmisartan (3 mg/kg + 1 mg/kg) and vehicle. Fourteen mice were used as non-diabetic controls. Results: After 12 weeks, urine and blood were obtained and blood pressure measured. Glucose concentrations were increased and similar in all diabetic groups. Telmisartan alone reduced systolic blood pressure by 5.9 mmHg versus diabetic controls (111.2 ± 2.3 mmHg vs 117.1 ± 2.2 mmHg; mean ± SEM; P=0.071). Combined treatment significantly reduced albuminuria compared with diabetic controls (71.7 ± 15.3 µg/24 h vs 170.8 ± 34.2 µg/24 h; P=0.017), whereas the effects of single treatment with either telmisartan (97.8 ± 26.4 µg/24 h) or linagliptin (120.8 ± 37.7 µg/24 h) were not statistically significant. DPP-4 inhibition, alone and in combination, led to significantly lower plasma osteopontin levels compared with telmisartan alone. Histological analysis revealed reduced glomerulosclerosis after Linagliptin alone and in combination with telmisartan in comparison to non treated diabetic animals (p<0.01 and p<0.05). Kidney malonaldehyde immune-reactivity, a marker of oxidative stress, was significantly lower in animals treated with linagliptin. Conclusions: DPP-4 inhibition on top of ARB treatment significantly reduced urinary albumin excretion and oxidative stress in diabetic eNOS knockout mice. Linagliptin on top of an angiotensin II receptor blocker may offer a new therapeutic approach for patients with diabetic nephropathy.

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Treatment with DPP-4 inhibitor linagliptin delays the progression of diabetic nephropathy damage in a glucose-independent and blood-pressure-independent manner. The observed effects may be because of the attenuation of podocyte injury and inhibition of myofibroblast transformation.

Dipeptidyl peptidase (DPP)-4 inhibitors delay chronic kidney disease (CKD) progression in experimental diabetic nephropathy in a glucose-independent manner. Here we compared the effects of the DPP-4 inhibitor linagliptin versus telmisartan in preventing CKD progression in non-diabetic rats with 5/6 nephrectomy. Animals were allocated to 1 of 4 groups: sham operated plus placebo; 5/6 nephrectomy plus placebo; 5/6 nephrectomy plus linagliptin; and 5/6 nephrectomy plus telmisartan. Interstitial fibrosis was significantly decreased by 48% with linagliptin but a non-significant 24% with telmisartan versus placebo. The urine albumin-to-creatinine ratio was significantly decreased by 66% with linagliptin and 92% with telmisartan versus placebo. Blood pressure was significantly lowered by telmisartan, but it was not affected by linagliptin. As shown by mass spectrometry, the number of altered peptide signals for linagliptin in plasma was 552 and 320 in the kidney. For telmisartan, there were 108 peptide changes in plasma and 363 in the kidney versus placebo. Linagliptin up-regulated peptides derived from collagen type I, apolipoprotein C1, and heterogeneous nuclear ribonucleoproteins A2/B1, a potential downstream target of atrial natriuretic peptide, whereas telmisartan up-regulated angiotensin II. A second study was conducted to confirm these findings in 5/6 nephrectomy wild-type and genetically deficient DPP-4 rats treated with linagliptin or placebo. Linagliptin therapy in wild-type rats was as effective as DPP-4 genetic deficiency in terms of albuminuria reduction. Thus, linagliptin showed comparable efficacy to telmisartan in preventing CKD progression in non-diabetic rats with 5/6 nephrectomy. However, the underlying pathways seem to be different.

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Early – intrauterine – environmental factors are linked to the development of cardiovascular disease in later life. Traditionally, these factors are considered to be maternal factors such as maternal under and overnutrition, exposure to toxins, lack of micronutrients, and stress during pregnancy. However, in the recent years, it became obvious that also paternal environmental factors before conception and during sperm development determine the health of the offspring in later life. We will first describe clinical observational studies providing evidence for paternal programming of adulthood diseases in progeny. Next, we describe key animal studies proving this relationship, followed by a detailed analysis of our current understanding of the underlying molecular mechanisms of paternal programming. Alterations of noncoding sperm micro-RNAs, histone acetylation, and targeted as well as global DNA methylation seem to be in particular involved in paternal programming of offspring's diseases in later life.

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Abstract-The losartan metabolite EXP3174 exhibits angiotensin II receptor 1 (AT1R)-blocking properties, whereas the metabolite EXP3179 potently induces the activity of the insulin-sensitizing peroxisome proliferator-activated receptor ␥ (PPAR␥) as a partial agonist in vitro. We investigated whether chronic treatment with losartan leads to sufficient serum levels of EXP3179 to activate PPAR␥ in monocytes derived from losartan-treated patients. Hypertensive patients (nϭ15) treated with losartan (100 mg/daily for at least the past 2 months) and untreated control patients (nϭ7) were included. Monocytes were extracted by negative isolation using a Dynal Monocyte Kit, followed by analysis of PPAR␥ target gene expression (CD36, ABC transporter G1 [ABCG1]) by quantitative real-time RT-PCR. Serum was prepared before, 2, 4, and 6 hours after losartan (100 mg) ingestion for HPLC-based determination of losartan, EXP3174, and EXP3179. Chronic treatment with losartan resulted in basal levels of losartan, EXP3174, and EXP3179 of 348.3Ϯ101.8 ng/mL, 115.3Ϯ56.1 ng/mL, and 176.2Ϯ143.4 ng/mL, respectively. Levels of both EXP3174 and EXP3179 were time-dependently increased in serum with a maximum 2 hours after drug intake (1706.0Ϯ760.1 ng/mL, 808.9Ϯ618.2 ng/mL, respectively). In consonance with detectable PPAR␥-activating EXP3179 serum levels, monocytic PPAR␥ target gene expression was significantly upregulated in patients treated with losartan by 3.75Ϯ0. Key Words: peroxisome proliferator-activated receptor gamma Ⅲ angiotensin receptor blocker Ⅲ losartan Ⅲ CD36 Ⅲ ABCG1 Ⅲ monocytes Ⅲ hypertension