Urotensin II levels in patients with chronic kidney disease and kidney transplants

Urotensin II can Induce Skeletal Muscle Atrophy Associated with Upregulating Ubiquitin-Proteasome System and Inhibiting the Differentiation of Satellite Cells in CRF Mice

Skeletal muscle wasting and atrophy is highly prevalent in chronic renal failure (CRF) and increases the risk of mortality. According to our previous study, we speculate that urotensin II (UII) can induce skeletal muscle atrophy by upregulating ubiquitin-proteasome system(UPS) in CRF. C2C12 mouse myoblast cells were differentiated into myotubes, and myotubes were exposed to different concentrations of UII. Myotube diameters, myosin heavy chain(MHC), p-Fxo03A, skeletal muscle-specific E3 ubiquitin ligases such as muscle RING finger 1 (MuRF1) and muscle atrophy F-box (MAFbx/atrogin1) were detected. Three animal models (the sham operation mice as normal control (NC) group, wild-type C57BL/6 mice with 5/6 nephrectomy (WT CRF) group, UII receptor gene knock out (UT KO) mice with 5/6 nephrectomy (UT KO CRF) group) were designed. Cross-sectional area (CSA) of skeletal muscle tissues in three animal models were measured, and western blot detected protein of UII, p-Fxo03A, MAFbx and MuRF1, and immunofluorescence assays explored the satellite cell marker of Myod1 and Pax7, and PCR arrays detected the muscle protein degradation genes, protein synthesis genes and the genes which were involved in muscle components. UII could decrease mouse myotube diameters, and upregulate dephosphorylated Fxo03A protein. MAFbx and MuRF1 were higher in WT CRF group than that in NC group, but after UII receptor gene was knocked out (UT KO CRF), their expressions were downregulated. UII could inhibit the expression of Myod1 but not Pax7 in animal study. We first demonstrate that skeletal muscle atrophy induced by UII associated with upregulating ubiquitin-proteasome system and inhibiting the differentiation of satellite cells in CRF mice.

A Pilot Study Using a Multistaged Integrated Analysis of Gene Expression and Methylation to Evaluate Mechanisms for Evening Fatigue in Women Who Received Chemotherapy for Breast Cancer

CONTEXT

Fatigue is the most common symptom associated with cancer and its treatment. Investigation of molecular mechanisms associated with fatigue may identify new therapeutic targets.

OBJECTIVE

The objective of this pilot study was to evaluate the relationships between gene expression and methylation status and evening fatigue severity in women with breast cancer who received chemotherapy.

METHODS

Latent class analysis (LCA) was used to identify evening fatigue phenotypes. In this analysis, the lowest (i.e., moderate, n = 7) and highest (i.e., very high, n = 29) fatigue-severity classes identified using LCA were analyzed via two stages. First, a total of 32,609 transcripts from whole blood were evaluated for differences in expression levels between the classes. Next, 637 methylation sites located within the putative transcription factor binding sites for those genes demonstrating differential expression were evaluated for differential methylation state between the classes.

RESULTS

A total of 89 transcripts in 75 unique genes were differentially expressed between the moderate (the lowest fatigue-severity class identified) and very high evening fatigue classes. In addition, 23 differentially methylated probes and three differentially methylated regions were found between the moderate and very high evening fatigue classes.

CONCLUSIONS

Using a multistaged integrated analysis of gene expression and methylation, differential methylation was identified in the regulatory regions of genes associated with previously hypothesized mechanisms for fatigue, including inflammation, immune function, neurotransmission, circadian rhythm, skeletal muscle energy, carbohydrate metabolism, and renal function as well as core biological processes including gene transcription and the cell-cycle regulation.

Serum angiopoietin-2 concentrations of post-PCI are correlated with the parameters of renal function in patients with coronary artery disease

Patients with coronary artery disease (CAD) frequently have comorbidity of chronic kidney disease (CKD). Their renal function may deteriorate because of the use of contrast agent after percutaneous coronary intervention (PCI). Angiopoietin-2 (Ang-2), which is highly expressed in the site of angiogenesis, plays an important role in both CAD and CKD. This study aimed to investigate the relation of serum Ang-2 concentrations with the renal function after PCI.This study enrolled 57 patients with CAD undergoing PCI. Blood samples for Ang-2 were collected in the first morning after admission and within 24 to 48 h after PCI. The parameters of renal function (serum creatinine, cystatin C and eGFR) were tested on the first day after admission and within 72 h after PCI.Overall, serum Ang-2 levels of post-PCI were significantly lower than those of pre-PCI [median, 1733 (IQR, 1100-2568) vs median, 2523 (IQR, 1702-3640) pg/mL; P < .001]. However, in patients with CKD (eGFR < 60 mL/min/1.73 m), there was no significant difference between serum Ang-2 levels of post-PCI and those of pre-PCI [median, 2851 (IQR, 1720-4286) vs. median, 2492 (IQR, 1434-4994) pg/mL; P = .925]. In addition, serum Ang-2 levels of post-PCI, but not pre-PCI, were significantly correlated with the post-PCI parameters of renal function.Serum Ang-2 concentrations of post-PCI are closely related to renal function in patients with CAD. It may have potential to be the early biomarker of contrast-induced nephropathy in the future.

Plasma Urotensin II levels in children and adolescents with chronic kidney disease: a single-centre study

Background

Increased plasma Urotensin II (UII) levels have been found in adults with renal diseases. Studies in children are scarce. The objective of the study is to estimate plasma UII levels in subjects with chronic kidney disease (CKD) stages 3 to 5 and renal transplant recipients (RTR). In addition, the correlation of UII with anthropometric features and biochemical parameters was assessed.

Methods

Fifty-four subjects, aged 3 to 20 years old, 23 with CKD, 13 with end-stage kidney disease (ESKD) undergoing hemodialysis (HD) and 18 RTR were enrolled. A detailed clinical evaluation was performed. Biochemical parameters of renal and liver function were measured. Plasma UII levels were measured in all patients and in 117 healthy controls, using a high sensitive enzyme immunoassay (EIA) kit. All data were analyzed using STATA™ (Version 10.1).

Results

Median UII and mean log-transformed UII levels were significantly higher in CKD and RTR patients compared to healthy subjects (p < 0.001). HD patients had higher but not statistically significant UII and log-UII levels than controls. UII levels increased significantly at the end of the HD session and were higher than controls and in line to those of other patients. The geometric scores of UII in HD (before dialysis), CKD and RTR patients increased respectively by 42, 136 and 164% in comparison with controls. Metabolic acidosis was associated with statistical significant change in log-UII levels (p = 0.001). Patients with metabolic acidosis had an increase in UII concentration by 76% compared to those without acidosis.

Conclusions

Children and adolescents with CKD, particularly those who are not on HD and RTR, have significantly higher levels of UII than healthy subjects. UII levels increase significantly at the end of the HD session. The presence of metabolic acidosis affects significantly plasma UII levels.

Progress in understanding role of urotensin Ⅱ in hepatic cirrhosis

Urotensin Ⅱ (UⅡ) is a potent vasoactive substance that can result in vasoactive response through interaction with its specific orphan G-protein-coupled receptor GPR-14. In addition to the role of vasoactivity, UⅡ can promote mitosis and fibrosis. The vascular role of UⅡ is to some degree both species- and disease-specific. Studies have found that plasma levels of UⅡ are elevated in patients with cirrhosis, but the relationship between plasma levels of UⅡ and the development of chronic liver disease and portal hypertension has yet to be fully elucidated. This review focuses on the potential relevance of UⅡ as vasoactive substance in chronic liver disease and the site where UⅡ is overproduced.

Urotensin II and the kidney

PURPOSE OF REVIEW

Urotensin II (UTS2), the most potent vasoconstrictor identified thus far, is an undecapeptide hormone with a structure that is highly conserved through mammalian phylogeny. In spite of its broad expression across the invertebrate and vertebrate world, the precise role of UTS2 in physiology and disease is still unknown. The first description of human UTS2 and its receptor brought initial promise of a potential therapeutic target for progressive renal disease, with vasoconstrictive and profibrotic actions within an autocrine and paracrine system and local renal generation that was upregulated with renal pathology.

RECENT FINDINGS

However, the last decade has not brought the successful development of new treatments first hoped for, with one small human clinical trial bearing negative results. What has become apparent is that the spectrum of actions of UTS2 is broad and often paradoxical. This ancient hormone has both vasoconstrictor and vasodilatory actions, has both profibrotic and antiapoptotic activity, as well as actions which are highly contextual on the particular vascular bed studied and on the presence or absence of superimposed disease state.

SUMMARY

With current development of newer UTS2 antagonists attempting to more closely replicate the ligand-receptor kinetics of UTS2 and its receptor, the focus on potential clinical applications of UTS2 inhibition has moved away from the kidney to the treatment of chronic lung and cardiovascular diseases.