ATP shows more potential as a urinary biomarker than acetylcholine and PGE2 , but its concentration in urine is not a simple function of dilution.

AIMS: To determine whether the amount of ATP, prostaglandin E2 (PGE2 ), and acetylcholine (ACh) in voided urine are influenced enough by that released within the lower urinary tract (LUT) for them to be useful biomarkers of bladder function. METHODS: Participants without LUT symptoms collected total urine voids at 15, 30, 60, and 120 min (20 males/23 females) and 240 min (18 males/26 females) following the previous void. Aliquots of urine were immediately frozen at -20°C and later used to measure ATP (luciferin-luciferase), PGE2 (enzyme-linked immunosorbent assay), ACh (mass spectrometry), creatinine (colorimetric), and lactose dehydrogenase (colorimetric). RESULTS: The amount of ATP in voided urine correlated strongly with the rate of urine production, suggesting that the majority, if not all, the ATP in voided urine has an LUT, and likely bladder, origin. In contrast, there appeared to be no significant net LUTs release of creatinine or ACh into the urine. PGE2 was intermediate with an LUT component that increased with urine production rate and contributed about 25% of the total at 1 ml/min in women but a smaller fraction in men. CONCLUSION: Whereas the majority of the ATP measured within the voided urine originates in the LUT, ACh reflects that extracted from the plasma in the kidneys and PGE2 is a mixture of both sources. ATP has the most potential as a biomarker of benign bladder disorders. Expressing urinary ATP concentration relative to creatinine concentration is questioned in light of these results.

Nephron-Specific Disruption of Polycystin-1 Induces Cyclooxygenase-2-Mediated Blood Pressure Reduction Independent of Cystogenesis.

BACKGROUND: Hypertension often occurs before renal function deteriorates in autosomal dominant polycystic kidney disease (ADPKD). It is unknown whether the Pkd1 gene product polycystin-1-the predominant causal factor in ADPKD-itself contributes to ADPKD hypertension independent of cystogenesis. METHODS: We induced nephron-specific disruption of the Pkd1 gene in 3-month-old mice and examined them at 4-5 months of age. RESULTS: Kidneys from the Pkd1 knockout mice showed no apparent renal cysts, tubule dilation, or increased cell proliferation. Compared with control mice, Pkd1 knockout mice exhibited reduced arterial pressure during high salt intake; this associated with an increased natriuretic, diuretic, and kaliuretic response during the first 2-3 days of salt loading. The lower arterial pressure and enhanced natriuresis during high salt loading in Pkd1 knockout mice were associated with lower urinary nitrite/nitrate excretion and markedly increased urinary PGE2 excretion, whereas GFR, plasma renin concentration, and urinary endothelin-1 excretion were similar between knockout and control mice. Kidney cyclooxygenase-2 protein levels were increased in Pkd1 knockout mice during high salt intake; administration of NS-398, a selective cyclooxygenase-2 inhibitor, abolished the arterial pressure difference between the knockout and control mice during high salt intake. Total kidney Na+/K+/2Cl- cotransporter isoform 2 (NKCC2) levels were greatly reduced in Pkd1 knockout mice fed a high salt diet compared with controls. CONCLUSIONS: These studies suggest that nephron polycystin-1 deficiency does not itself contribute to ADPKD hypertension and that it may, in fact, exert a relative salt-wasting effect. The work seems to comprise the first in vivo studies to describe a potential physiologic role for nephron polycystin-1 in the absence of cysts, tubule dilation, or enhanced cell proliferation.

Chloroquine attenuates lithium-induced NDI and proliferation of renal collecting duct cells.

Lithium is widely used in psychiatry as the golden standard for more than 60 yr due to its effectiveness. However, its adverse effect has been limiting its long-term use in clinic. About 40% of patients taking lithium develop nephrogenic diabetes insipidus (NDI). Lithium can also induce proliferation of collecting duct cells, leading to microcyst formation in the kidney. Lithium was considered an autophagy inducer that might contribute to the therapeutic benefit of neuropsychiatric disorders. Thus, we hypothesized that autophagy may play a role in lithium-induced kidney nephrotoxicity. To address our hypothesis, we fed mice with a lithium-containing diet with chloroquine (CQ), an autophagy inhibitor, concurrently. Lithium-treated mice presented enhanced autophagy activity in the kidney cortex and medulla. CQ treatment significantly ameliorated lithium-induced polyuria, polydipsia, natriuresis, and kaliuresis accompanied with attenuated downregulation of aquaporin-2 and Na+-K+-2Cl- cotransporter protein. The protective effect of CQ on aquaporin-2 protein abundance was confirmed in cultured cortical collecting duct cells. In addition, we found that lithium-induced proliferation of collecting duct cells was also suppressed by CQ as detected by proliferating cell nuclear antigen staining. Moreover, both phosphorylated mammalian target of rapamycin and ß-catenin expression, which have been reported to be increased by lithium and associated with cell proliferation, were reduced by CQ. Taken together, our study demonstrated that CQ protected against lithium-induced NDI and collecting duct cell proliferation possibly through inhibiting autophagy.

Urinary prostaglandin E2 is a biomarker of early adaptive hyperfiltration in solitary functioning kidney.

INTRODUCTION: Hyperfiltration is a major contributor to progression of chronic kidney disease (CKD) in diabetes, obesity and in individuals with solitary functioning kidney (SFK). We have proposed hyperfiltration-induced injury as a continuum of overlapping glomerular changes caused by increased biomechanical forces namely, fluid flow shear stress (FFSS) and tensile stress. We have shown that FFSS is elevated in animals with SFK and, it upregulates prostaglandin E2 (PGE2), cyclooxygenase-2 and PGE2 receptor EP2 in cultured podocytes and in uninephrectomized mice. We conceptualized urinary PGE2 as a biomarker of early effects of hyperfiltration-induced injury preceding microalbuminuria in individuals with SFK. We studied children with SFK to validate our hypothesis. METHODS: Urine samples from children with SFK and controls were analyzed for PGE2, albumin (glomerular injury biomarker) and epidermal growth factor (EGF, tubular injury biomarker). Age, gender, and Z-scores for height, weight, BMI, and blood pressure were obtained. RESULTS: Children with SFK were comparable to controls except for lower BMI Z-scores. The median values were elevated in SFK compared to control for urine PGE2 [9.1 (n = 57) vs. 5.7 (n = 72), p = 0.009] ng/mgCr and albumin [7.6 (n = 40) vs. 7.0 (n = 41), p = 0.085] µg/mgCr, but not for EGF [20098 (n = 44) vs. 18637 (n = 44), p = 0.746] pg/mgCr. Significant increase in urinary PGE2 (p = 0.024) and albumin (p = 0.019) but not EGF (p = 0.412) was observed using additional regression modeling. These three urinary analytes were independent of each other. CONCLUSION: Increased urinary PGE2 from elevated SNGFR and consequently increased FFSS during early stage of CKD precedes overt microalbuminuria and is a biomarker for early hyperfiltration-induced injury in individuals with SFK.

Identification of Acer2 as a First Susceptibility Gene for Lithium-Induced Nephrogenic Diabetes Insipidus in Mice.

BACKGROUND: Lithium, mainstay treatment for bipolar disorder, causes nephrogenic diabetes insipidus and hypercalcemia in about 20% and 10% of patients, respectively, and may lead to acidosis. These adverse effects develop in only a subset of patients treated with lithium, suggesting genetic factors play a role. METHODS: To identify susceptibility genes for lithium-induced adverse effects, we performed a genome-wide association study in mice, which develop such effects faster than humans. On day 8 and 10 after assigning female mice from 29 different inbred strains to normal chow or lithium diet (40 mmol/kg), we housed the animals for 48 hours in metabolic cages for urine collection. We also collected blood samples. RESULTS: In 17 strains, lithium treatment significantly elevated urine production, whereas the other 12 strains were not affected. Increased urine production strongly correlated with lower urine osmolality and elevated water intake. Lithium caused acidosis only in one mouse strain, whereas hypercalcemia was found in four strains. Lithium effects on blood pH or ionized calcium did not correlate with effects on urine production. Using genome-wide association analyses, we identified eight gene-containing loci, including a locus containing Acer2, which encodes a ceramidase and is specifically expressed in the collecting duct. Knockout of Acer2 led to increased susceptibility for lithium-induced diabetes insipidus development. CONCLUSIONS: We demonstrate that genome-wide association studies in mice can be used successfully to identify susceptibility genes for development of lithium-induced adverse effects. We identified Acer2 as a first susceptibility gene for lithium-induced diabetes insipidus in mice.

Prediagnostic levels of urinary 8-epi-prostaglandin F2α and prostaglandin E2 metabolite, biomarkers of oxidative damage and inflammation, and risk of hepatocellular carcinoma.

Chronic inflammation and oxidative stress play pivotal roles in the pathogenesis of hepatocellular carcinoma (HCC). We conducted a nested case-control study of 347 HCC cases and 691 matched controls within a prospective cohort of 18 244 Chinese men in Shanghai, China. The concentrations of 8-epi-prostaglandin F2α (8-epi-PGF2α), a biomarker of oxidative stress, and prostaglandin E2 (PGE2) metabolite (PGE-M), a biomarker of the inflammation mediator PGE2, were determined in baseline urine samples using validated mass spectrometry assays. 8-epi-PGF2α levels were significantly higher in HCC cases than control subjects (geometric means 0.92 versus 0.80 pmol/mg creatinine, P < 0.001). The relative risks of developing HCC for the highest relative to the lowest quartile of 8-epi-PGF2α were 2.55 (95% confidence interval = 1.62-4.01, Ptrend < 0.001). This positive 8-epi-PGF2α-HCC risk association was independent of smoking status, alcohol consumption and hepatitis B or liver cirrhosis and was present 10 years before the clinical manifestation of HCC. This study did not find any significant association between urinary PEG-M and HCC risk. This study provides direct evidence in support of the critical role of oxidative stress in the development of HCC regardless of its underlying causes.

Urinary prostaglandin D2 and E2 metabolites associate with abdominal obesity, glucose metabolism, and triglycerides in obese subjects.

Obesity is associated with low-grade chronic inflammation, which contributes to the development of the metabolic syndrome and its associated complications, such as insulin resistance and type-2 diabetes. Limited data from animal and human studies support local generation of pro-inflammatory prostanoid lipid mediators in white adipose tissue. However, the link between systemic prostanoid levels and parameters characterizing the metabolic syndrome is missing in human obesity. Therefore, we performed a targeted lipidomic analysis using urine samples from obese human subjects (n = 45) and show for the first time in humans that urinary prostanoid levels correlate with metabolic parameters that indicate a dysregulated glucose and triglyceride metabolism. We identified tetranor-PGDM and tetranor-PGEM as the two major urinary prostanoid metabolites in obese subjects with levels of 247 ±â€¯31 and 23.3 ±â€¯4.0 pmol/mg creatinine, respectively. Tetranor-PGDM was significantly associated with serum triglycerides, while tetranor-PGEM was associated with abdominal obesity as defined by an increased waist-to-hip ratio (WHR), with glycated hemoglobin (HbA1c), and with impaired oral glucose tolerance. These results confirm the previously established notion of low-grade chronic inflammation in obesity and further identify an association of the prostanoid pathway with obesity-associated dyslipidemia, abdominal obesity, and insulin resistance.

Urinary TIMP-2 and MMP-2 are significantly associated with poor bladder compliance in adult patients with spina bifida.

AIMS: To assess the predictive values of six urinary markers (nerve growth factor [NGF], brain-derived neurotrophic factor [BDNF], matrix metalloproteinase 2 [MMP-2], tissue inhibitor metalloproteinase 2 [TIMP-2], transformation growth factor ß-1 [TGF-B1], and prostaglandin 2 [PGE2]) for adverse urodynamic features and for upper urinary tract damage in adult patients with spina bifida. MATERIALS AND METHODS: A single-center prospective trial was conducted from March 2015 to March 2017 including all consecutive adult patients with spina bifida seen for urodynamic testing. The urine was collected and stored at -80°C. A urodynamic and an upper urinary tract were systematically performed. At the end of the inclusion period, urines were defrosted and urinary nerve growth factor, BDNF, TIMP-2, and TGF-B1 were assessed using validated ELISA kits. The urinary markers levels were adjusted on the urinary creatinine level. Urinary MMP-2 levels were assessed by zymography. RESULTS: Fourty patients were included. Only TIMP-2 and MMP-2 were significantly associated with poor bladder compliance (P = .043 and P = .039, respectively). TIMP-2 was also the only urinary marker significantly associated with upper urinary tract damage on imaging (OR = 19.81; P = .02). Of all urodynamic parameters, bladder compliance and maximum detrusor pressure were the only ones associated with upper urinary tract damage on imaging (P = .01 and P = .02), The diagnostic performances of urinary TIMP-2 for upper urinary tract damage were slightly superior to PdetMax and bladder compliance with an area under the curve of 0.72. CONCLUSION: Urinary TIMP-2 and MMP-2 were significantly associated with poor bladder compliance and urinary TIMP-2 was significantly associated with upper urinary tract damage. These findings support a pathophysiological role of extracellular matrix remodeling in poor bladder compliance of adult patients with spina bifida.

Urinary PGE2 metabolite levels in hospitalised infants with infections compared to age-matched controls.

AIM: To determine the urinary tetranor-prostaglandin E2 metabolite in healthy infants and in hospitalised infants with upper and lower respiratory tract as well as gastrointestinal infections. METHODS: A prospective cross-sectional study to determine baseline concentrations of urinary tetranor-prostaglandin E2 metabolite was conducted in 81 healthy infants aged one week to one year and in 142 hospitalised infants with infections. Prostaglandin metabolite levels were measured by liquid chromatography tandem mass spectrometry. RESULTS: In healthy infants, urinary prostaglandin E2 metabolite levels decreased with age and did not differ between girls and boys. Infections of the lower respiratory (n = 78) and gastrointestinal tract (n = 12) correlated with increased levels of the prostaglandin E2 metabolite. In contrast, infants hospitalised with upper respiratory tract infections (n = 23) exhibited similar levels as healthy, age-matched controls. Lower prostaglandin E2 levels were found after treatment with acetaminophen in hospitalised children. Prostaglandin E2 metabolite levels did not correlate with length of hospitalisation or need for respiratory support. CONCLUSION: This study first provides normal levels of urinary prostaglandin E2 metabolite in infants and secondly demonstrates elevated levels in hospitalised children with lower respiratory tract and gastrointestinal infections.

The Determination and Clinical Significance of Prostaglandin E2 in Blood and Urine of Patients with Renal Colic.

BACKGROUND: This study explores the role of prostaglandin E2 (PGE2) in the etiology of urolithiasis in acute renal colic by analyzing the PGE2 levels in blood and urine throughout the clinical course of renal colic. METHODS: From June 2015 to November 2017, a total of 60 patients with acute renal colic were enrolled in the study. Blood and urine samples were taken before and after administration of drug to inhibit prostaglandin synthesis; further blood and urine samples were obtained from the patients 2 weeks after their recovery. The concentration of PGE2 in blood and urine samples was determined by using a Human Prostaglandin E2 ELISA Kit. RESULTS: The mean concentration of PGE2 was 420 ± 50.3 ng/L in blood and 600 ± 70.1 ng/L in urine when the patients had renal colic. After drug therapy, these concentrations fell to 300 ± 40.4 ng/L in blood and 500 ± 54.5 ng/L in urine. After 2 weeks the PGE2 concentration was 220 ± 47.5 ng/L and 300 ± 50.2 ng/L in blood and urine, respectively. Compared with PGE2 levels after medication, these concentrations were significantly higher during acute renal colic (p < 0.05). CONCLUSIONS: The synthesis and release of PGE2 increase at the onset of renal colic, suggesting that PGE2 plays an important role in acute renal colic. Administration of a prostaglandin synthesis inhibitor is a reliable way to treat renal colic.

Evaluation of pro-inflammatory markers plasma C-reactive protein and urinary prostaglandin-E2 metabolite in colorectal adenoma risk.

C-reactive protein (CRP) is a pro-inflammatory protein with potential as a biomarker in predicting colon cancer risk. However, little is known regarding its association with risk of colorectal adenomas, particularly by subtypes. We conducted a colonoscopy-based matched case-control study to assess whether elevated plasma CRP levels may be associated with colorectal adenoma risk and further whether this association may be modified by urinary prostaglandin E2 metabolite (PGE-M), a biomarker of systemic prostaglandin E2 production. Included in the study were 226 cases with a single small tubular adenoma, 198 cases with multiple small tubular adenomas, 283 cases with at least one advanced adenoma, and 395 polyp-free controls. No apparent association between CRP level and risk of single small tubular adenomas was found (ptrend = 0.59). A dose-response relationship with CRP level was observed for risk of either multiple small tubular adenomas (OR = 2.01, 95%CI = 1.10-3.68 for the highest versus lowest tertile comparison; ptrend = 0.03) or advanced adenomas (OR = 1.81, 95%CI = 1.10-2.96 for the highest versus lowest tertile comparison; ptrend = 0.02). In a joint analysis of CRP level and PGE-M, risk of multiple or advanced adenoma was greatest among those with highest levels of both CRP and PGE-M in comparison to those with low CRP and low PGE-M (OR = 3.72, 95%CI = 1.49-9.72). Our results suggest that elevated CRP, particularly in the context of concurrent elevated PGE-M, may be a biomarker of multiple or advanced adenoma risk in a screening age population. © 2015 Wiley Periodicals, Inc.

Randomized phase 2 trial of erlotinib in combination with high-dose celecoxib or placebo in patients with advanced non-small cell lung cancer.

BACKGROUND: Cyclooxygenase 2 (COX-2)-dependent signaling represents a potential mechanism of resistance to therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors. This is mediated in part through an EGFR-independent activation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (Erk) by prostaglandin E2 (PGE2). PGE2 promotes downregulation of E cadherin and epithelial to mesenchymal transition. The current study investigated EGFR and COX-2 inhibition in patients with non-small cell lung cancer (NSCLC) and elevated baseline urinary metabolite of PGE2 (PGEM). METHODS: Patients with stage IIIB/IV (AJCC 6th edition) NSCLC who progressed after at least 1 line of therapy or refused standard chemotherapy were randomized to receive erlotinib and celecoxib versus erlotinib and placebo. The primary endpoint was progression-free survival (PFS) with 80% power to detect a 50% improvement with a 1-sided significance level of .2 in the intent-to-treat and elevated baseline PGEM populations. Secondary endpoints included response rate, overall survival, and evaluation of molecular markers to assess targeting COX-2-related pathways and evaluate EGFR tyrosine kinase inhibitor resistance. RESULTS: A total of 107 patients were enrolled with comparable baseline characteristics. Among the patients treated with celecoxib, those with wild-type EGFR were found to have an increased PFS (3.2 months vs 1.8 months; P = .03). PFS was numerically improved among patients in the intent-to-treat group who received erlotinib and celecoxib compared with those treated with erlotinib and placebo (5.4 months vs 3.5 months; P = .33) and was increased in patients in the erlotinib and celecoxib arm with elevated baseline PGEM (5.4 months vs 2.2 months; P = .15). Adverse events were similar in both treatment arms. CONCLUSIONS: The combination of erlotinib and celecoxib did not appear to improve outcomes in an unselected population, but selection by elevated baseline PGEM led to an increase in PFS with this combination. Patients with EGFR wild-type status may benefit from the combination of erlotinib and celecoxib.

Fruit and vegetable intake and urinary levels of prostaglandin E2 metabolite in postmenopausal women.

Prostaglandin E2 (PGE2) is an inflammatory mediator that plays key roles in promoting tumor development and progression. Urinary concentration of a major PGE2 metabolite (PGE-M) has been recently proposed as a promising cancer biomarker. Using dietary intake data from 600 postmenopausal women aged 50-74 years, we examined cross-sectional relationships between fruit and vegetable intake and urinary levels of PGE-M, determined using liquid chromatography/tandem mass spectrometry. After multivariable adjustment, increasing consumption of fruits, but not vegetables, was associated with reduced levels of urinary PGE-M (P for linear trend = 0.02), with geometric means of 5.8 [95% confidence interval (CI): 5.2-6.6] in the lowest quintile versus 4.8 (95% CI: 4.3-5.4) in the highest quintile (Q5) of fruit consumption. A better quality diet, indicated by higher scores on the Healthy Eating Index, was also associated with decreased PGE-M (P for linear trend <0.01). The lack of association with vegetable intake may be related to variation in antioxidant capacities of the major dietary sources of fruits and vegetables for the study participants. Our findings suggest that urinary PGE-M may be modifiable by a healthy diet that follows current national dietary guideline. Further studies are warranted to assess potential utility of urinary PGE-M in assessing cancer prevention efficacy.

Clopidogrel attenuates lithium-induced alterations in renal water and sodium channels/transporters in mice.

Lithium (Li) administration causes deranged expression and function of renal aquaporins and sodium channels/transporters resulting in nephrogenic diabetes insipidus (NDI). Extracellular nucleotides (ATP/ADP/UTP), via P2 receptors, regulate these transport functions. We tested whether clopidogrel bisulfate (CLPD), an antagonist of ADP-activated P2Y(12) receptor, would affect Li-induced alterations in renal aquaporins and sodium channels/transporters. Adult mice were treated for 14 days with CLPD and/or Li and euthanized. Urine and kidneys were collected for analysis. When administered with Li, CLPD ameliorated polyuria, attenuated the rise in urine prostaglandin E2 (PGE2), and resulted in significantly higher urinary arginine vasopressin (AVP) and aldosterone levels as compared to Li treatment alone. However, urine sodium excretion remained elevated. Semi-quantitative immunoblotting revealed that CLPD alone increased renal aquaporin 2 (AQP2), Na-K-2Cl cotransporter (NKCC2), Na-Cl cotransporter (NCC), and the subunits of the epithelial Na channel (ENaC) in medulla by 25-130 %. When combined with Li, CLPD prevented downregulation of AQP2, Na-K-ATPase, and NKCC2 but was less effective against downregulation of cortical α- or γ-ENaC (70 kDa band). Thus, CLPD primarily attenuated Li-induced downregulation of proteins involved in water conservation (AVP-sensitive), with modest effects on aldosterone-sensitive proteins potentially explaining sustained natriuresis. Confocal immunofluorescence microscopy revealed strong labeling for P2Y(12)-R in proximal tubule brush border and blood vessels in the cortex and less intense labeling in medullary thick ascending limb and the collecting ducts. Therefore, there is the potential for CLPD to be directly acting at the tubule sites to mediate these effects. In conclusion, P2Y(12)-R may represent a novel therapeutic target for Li-induced NDI.

[Genetic diagnosis for a Chinese Han family with primary hypertrophic osteoarthropathy].

OBJECTIVE: To identify the genetic cause for a Chinese Han family affected with primary hypertrophic osteoarthropathy. METHODS: Whole blood and urine samples were collected from a patient and 7 unaffected relatives of the family. The coding sequences and intron/exon boundaries of HPGD and SLCO2A1 genes of the patient were amplified with polymerase chain reaction and sequenced. The genotypes of relatives were subsequently verified. Urinary prostaglandin level was measured with enzyme-linked immunosorbent assay (ELISA). RESULTS: A homozygous 2-bp deletion in HPGD gene (c.310_311delCT, or p.L104AfsX3) was detected in the patient, and 5 heterozygous carriers were identified in the relatives. The urinary prostaglandin E2 (PGE2) level was significantly elevated (P<0.01), while PGE-M was significantly reduced (P<0.01) in the patient. CONCLUSION: Primary hypertrophic osteoarthropathy in this family is caused by a homozygous mutation (c.310_311delCT) in the HPGD gene.

Carbon in airway macrophages from children with asthma.

BACKGROUND: Airway macrophage (AM) phagocytosis is impaired in severe asthma. Prostaglandin (PG) E2 and D2 are increased in severe asthma and suppress AM phagocytic function in vitro. In this study, we sought evidence for PG-mediated impairment of phagocytosis of inhalable carbonaceous particulate matter (PM) by AM in children with severe asthma compared with mild asthmatics and healthy controls. METHODS: AM were obtained from children with asthma and healthy controls using induced sputum. AM carbon area (µm(2)) was assessed by image analysis. In a subgroup of asthmatics, urinary PGE2 and PGD2 metabolites were measured by high-performance liquid chromatography, and PM exposure at the home address was modelled. Phagocytosis of PM by human monocyte-derived macrophages and rat AM was assessed in vitro by image analysis. RESULTS: AM carbon was 51% lower in children with moderate-to-severe asthma (n=36) compared with mild asthmatics (n=12, p<0.01) and healthy controls (n=47, p<0.01). There was no association between modelled PM exposure and AM carbon in 33 asthmatics who had a urine sample, but there was an inverse association between AM carbon and urinary metabolites of PGE2 and D2 (n=33, rs=-0.40, p<0.05, and rs=-0.44, p<0.01). PGE2 10(-6) M, but not PGD2 10(-6) M, suppressed phagocytosis of PM10 by human macrophages in vitro (p<0.05 vs control). PGE2 10(-6) M also suppressed phagocytosis of PM10 by rat AM in vitro (p<0.01 vs control). CONCLUSIONS: Phagocytosis of inhaled carbonaceous PM by AMs is impaired in severe asthma. PGE2 may contribute to impaired AM phagocytic function in severe asthma.

Urinary nerve growth factor correlates with the severity of urgency and pain.

INTRODUCTION AND HYPOTHESIS: Urinary nerve-growth-factor (NGF) level reflected the severity of urgency in patients with lower urinary tract symptoms (LUTS) and pain in patients with Bladder pain syndrome/interstitial cystitis (BPS/IC). The aim of this study was to investigate the levels of biomarkers, nerve growth factor (NGF), and prostaglandin E2 (PGE2) among disease groups sharing similar urinary symptoms and to elucidate which symptoms are related to individual biomarker levels. METHODS: We studied 83 patients with LUTS who visited our outpatient clinic from May 2011 to December 2012. On the basis of clinical symptoms and a 3-day voiding diary, patients were classified into three groups: those with frequency (n = 13), overactive bladder (OAB) (n = 35), and BPS/IC (n = 35). Patients with stress urinary incontinence (SUI) or microscopic hematuria served as controls (n = 24). Storage symptoms were evaluated based on OAB symptom score (OAB-SS). RESULTS: Mean patient age was 62.08 ± 11.47 (range, 23-84). Urinary NGF and creatinine-normalized NGF levels were significantly increased in those with OAB (201.90 and 4.08, respectively) and BPS/IC (173.71 and 2.72) compared with controls (77.77 and 1.29) and those with frequency (67.76 and 1.23). Neither value significantly differed between OAB and BPS/IC patients or between controls and frequency patients. Urinary PGE2 and creatinine-normalized PGE2 levels were not significantly different among groups. On linear regression analysis, urinary NGF levels were significantly correlated with urgency severity overall (R = 0.222) and also pain in BPS/IC patients (R = 0.409). CONCLUSIONS: The levels of urinary NGF were elevated in patients with OAB and BPS/IC but not those with frequency and reflected the severity of urgency. In BPS/IC patients, urinary NGF increased with pain severity.

Protection of Wistar-Furth rats against postischaemic acute renal injury: role for nitric oxide and thromboxane?

The Wistar-Furth (WF) rat strain is usually used in models of full major histocompatibility complex-mismatched kidney transplantation. Because these rats have been demonstrated to be resistant to several models of chronic kidney disease, the aim of the present study was to investigate their potential resistance to renal ischaemia-reperfusion (I/R) injury compared with another strain, namely Wistar-Hanover (WH) rats. Anaesthetized male WH and WF rats were submitted to I/R by occlusion of the left renal artery and contralateral nephrectomy. Urine, blood and tissue samples were collected at different time points after I/R to evaluate renal function, inflammation and tubular injury, along with determination of nitric oxide synthase (NOS) expression and thromboxane A2 (TxA2 ) production. Post-ischaemic renal function was better preserved in WF than WH rats, as evidenced by reduced levels of creatininaemia, urinary neutrophil gelatinase-associated lipocalin excretion and proteinuria. In addition, WF rats had less intrarenal inflammation than WH rats after I/R injury. These observations were associated with maintenance of neuronal NOS expression, along with lower induction of inducible NOS expression in WF versus WH rats. Moreover, WF rats excreted a significantly lower amount of TxB2 . The results indicate that WF rats are more resistant to an I/R injury than WH rats in terms of renal function and inflammation. These observations are associated with differential regulation of intrarenal NOS expression, as well as a reduction in thromboxane production, which could contribute to a better outcome for the postischaemic kidney in WF rats.

Safety and efficacy of skin patches containing loxoprofen sodium in diabetic patients with overt nephropathy.

BACKGROUND: Because oral nonsteroidal anti-inflammatory drugs (NSAIDs) have adverse effects on kidney function, patients with kidney diseases are administered these drugs as transdermal patches. Little is known about the effects of NSAID patches on renal function. We therefore assessed the effects of topical loxoprofen sodium on kidney function in type 2 diabetic patients with overt nephropathy. METHODS: Twenty patients with type 2 diabetes and overt proteinuria and with knee and/or low back pain were treated with skin patches containing 100 mg loxoprofen on the knee or back for 24 h per day for 5 consecutive days. The degree of pain was assessed using a visual analogue scale (VAS). Blood and 24-h urine samples were obtained at baseline and at the end of the study. Glomerular filtration rate (GFR) was estimated from serum creatinine and cystatin C concentrations. RESULTS: The 20 patients consisted of 11 males and 9 females, of mean age 61.6 ± 13.9 years. Loxoprofen-containing patches significantly reduced VAS pain without affecting blood pressure, GFR or urinary prostaglandin E2 concentration. Serum concentrations of loxoprofen and its active trans-OH metabolite did not correlate with GFR. CONCLUSIONS: Loxoprofen-containing patches do not affect renal function in type 2 diabetic patients with overt nephropathy over a short-term period. Long-term studies are needed to clarify the safety of loxoprofen-containing patches in patients with chronic kidney diseases.

Is there a role for PGE2 in urinary concentration?

Prostanoids are prominent, yet complex, components in the maintenance of body water homeostasis. Recent functional and molecular studies have revealed that the local lipid mediator PGE2 is involved both in water excretion and absorption. The biologic actions of PGE2 are exerted through four different G-protein-coupled receptors; designated EP1-4, which couple to separate intracellular signaling pathways. Here, we discuss new developments in our understanding of the actions of PGE2 that have been uncovered utilizing receptor specific agonists and antagonists, EP receptor and PG synthase knockout mice, polyuric animal models, and the new understanding of the molecular regulation of collecting duct water permeability. The role of PGE2 in urinary concentration comprises a variety of mechanisms, which are not fully understood and likely depend on which receptor is activated under a particular physiologic condition. EP3 and microsomal PG synthase type 1 play a role in decreasing collecting duct water permeability and increasing water excretion, whereas EP2 and EP4 can bypass vasopressin signaling and increase water reabsorption through two different intracellular signaling pathways. PGE2 has an intricate role in urinary concentration, and we now suggest how targeting specific prostanoid receptor signaling pathways could be exploited for the treatment of disorders in water balance.