Differential modulation of transendothelial electrical resistance by TRPV4 agonists is mediated by apoptosis and/or necrosis.

Transient receptor potential vanilloid 4 (TRPV4) has been implicated in many disease conditions also in the lung. Its activation leads to an increase endothelial permeability in an intracellular calcium-influx dependent manner. We investigated its function in vitro on primary human endothelial cells using two TRPV4 agonists, GSK1016790A and 4α-Phorbol 12,13-didecanoate (4α-PDD) and a selective TRPV4 blocker GSK2193874. Both TRPV4 agonists leaded to a reduction in transendothelial electrical resistance (TER) which was mediated however by differential cytotoxic effects. 4α-PDD induced apoptosis that could not be blocked by TRPV4 inhibition in HUVECs, whereas GSK1016790A selectively activated TRPV4 and reduced TER as a consequence of cellular necrosis. TRPV4 mediated cytotoxicity is poorly described and may provide significant context to the role of TRPV4 in barrier-function.

TRPV4 inhibition attenuates stretch-induced inflammatory cellular responses and lung barrier dysfunction during mechanical ventilation.

Mechanical ventilation is an important tool for supporting critically ill patients but may also exert pathological forces on lung cells leading to Ventilator-Induced Lung Injury (VILI). We hypothesised that inhibition of the force-sensitive transient receptor potential vanilloid (TRPV4) ion channel may attenuate the negative effects of mechanical ventilation. Mechanical stretch increased intracellular Ca2+ influx and induced release of pro-inflammatory cytokines in lung epithelial cells that was partially blocked by about 30% with the selective TRPV4 inhibitor GSK2193874, but nearly completely blocked with the pan-calcium channel blocker ruthenium red, suggesting the involvement of more than one calcium channel in the response to mechanical stress. Mechanical stretch also induced the release of pro-inflammatory cytokines from M1 macrophages, but in contrast this was entirely dependent upon TRPV4. In a murine ventilation model, TRPV4 inhibition attenuated both pulmonary barrier permeability increase and pro-inflammatory cytokines release due to high tidal volume ventilation. Taken together, these data suggest TRPV4 inhibitors may have utility as a prophylactic pharmacological treatment to improve the negative pathological stretch-response of lung cells during ventilation and potentially support patients receiving mechanical ventilation.

Spleen tyrosine kinase inhibition blocks airway constriction and protects from Th2-induced airway inflammation and remodeling.

BACKGROUND: Spleen tyrosine kinase (Syk) is an intracellular nonreceptor tyrosine kinase, which has been implicated as central immune modulator promoting allergic airway inflammation. Syk inhibition has been proposed as a new therapeutic approach in asthma. However, the direct effects of Syk inhibition on airway constriction independent of allergen sensitization remain elusive. METHODS: Spectral confocal microscopy of human and murine lung tissue was performed to localize Syk expression. The effects of prophylactic or therapeutic Syk inhibition on allergic airway inflammation, hyperresponsiveness, and airway remodeling were analyzed in allergen-sensitized and airway-challenged mice. The effects of Syk inhibitors BAY 61-3606 or BI 1002494 on airway function were investigated in isolated lungs of wild-type, PKCα-deficient, mast cell-deficient, or eNOS-deficient mice. RESULTS: Spleen tyrosine kinase expression was found in human and murine airway smooth muscle cells. Syk inhibition reduced allergic airway inflammation, airway hyperresponsiveness, and pulmonary collagen deposition. In naïve mice, Syk inhibition diminished airway responsiveness independently of mast cells, or PKCα or eNOS expression and rapidly reversed established bronchoconstriction independently of NO. Simultaneous inhibition of Syk and PKC revealed additive dilatory effects, whereas combined inhibition of Syk and rho kinase or Syk and p38 MAPK did not cause additive bronchodilation. CONCLUSIONS: Spleen tyrosine kinase inhibition directly attenuates airway smooth muscle cell contraction independent of its protective immunomodulatory effects on allergic airway inflammation, hyperresponsiveness, and airway remodeling. Syk mediates bronchoconstriction in a NO-independent manner, presumably via rho kinase and p38 MAPK, and Syk inhibition might present a promising therapeutic approach in chronic asthma as well as acute asthma attacks.

Testosterone therapy and mortality risk.

Recent data suggest an increased risk of cardiovascular events and mortality in men on testosterone therapy (TT). To date, there are no long-term, prospective studies to determine safety. In such cases, retrospective observational studies can be helpful. We examined our patient database to determine whether TT altered the risk of all-cause mortality in men. We queried our hormone database for all men with a serum testosterone level and then examined charts to determine testosterone status. In all, 509 men had charts available for review. We linked our patient records to the National Death Index to determine mortality. Of the 509 men who met inclusion criteria, 284 were on TT and 225 did not use testosterone. Age (mean 54 years) and follow-up time (mean 10 years) were similar for both groups. In all, 19 men died--10 (4.4%) men not on TT and 9 (3.2%) men on TT. After adjusting for age and year of evaluation, there was no significant difference in the risk of death based on TT (hazard ratio 0.92, 95% confidence interval 0.36-2.35, P=1.0). There appears to be no change in mortality risk overall for men utilizing long-term testosterone therapy.

Measurement of endothelial dysfunction via peripheral arterial tonometry predicts vasculogenic erectile dysfunction.

Endothelial cell dysfunction is associated with cardiovascular disease and vasculogenic erectile dysfunction (ED). Measured via peripheral artery tonometry (PAT), endothelial dysfunction in the penis is an independent predictor of future cardiovascular events. The aim of the study was to determine whether measurement of endothelial dysfunction differentiates men with vasculogenic ED identified by duplex ultrasound from those without. A total of 142 men were retrospectively assessed using patient history, penile duplex ultrasonography (US) and PAT (EndoPAT 2000). ED was self-reported and identified on history. Vasculogenic ED was identified in men who exhibited a peak systolic velocity (PSV) of ⩽ 25 cm s(-1) at 15 min following vasodilator injection. The reactive hyperemia index (RHI), a measurement of endothelial dysfunction in medium/small arteries, and the augmentation index (AI), a measurement of arterial stiffness, were recorded via PAT. Penile duplex US was used to categorize men into those with ED (n = 111) and those without ED (n = 31). The cohort with ED had a PSV of 21 ± 1 cm s(-1) (left cavernous artery) and 22 ± 1 cm s(-1) (right cavernous artery). The control group without ED had values of 39 ± 2 cm s(-1) (left) and 39 ± 2 cm s(-1) (right). Given the potential for altered endothelial function in diabetes mellitus, we confirmed that hemoglobin A1c, urinary microalbumin and vibration pulse threshold were not different in men with vasculogenic ED and those without. RHI in patients with ED (1.85 ± 0.06) was significantly decreased compared to controls (2.15 ± 0.2) (P<0.05). The AI was unchanged when examined in isolation, and when standardized to heart rate. Measurement of endothelial function with EndoPAT differentiates men with vasculogenic ED from those without. RHI could be used as a non-invasive surrogate in the assessment of vasculogenic ED and to identify those patients with higher cardiovascular risk.

Correlation between simultaneous PSA and serum testosterone concentrations among eugonadal, untreated hypogonadal and hypogonadal men receiving testosterone replacement therapy.

The primary objective of this study was to correlate simultaneous measures of prostate-specific antigen (PSA) and serum testosterone among large samples of eugonadal, untreated hypogonadal and hypogonadal men treated with testosterone replacement therapy (TRT). From 2001 to 2007, laboratory records were reviewed to identify men who underwent simultaneous measurement of PSA and serum testosterone levels. The data were stratified based on three groups of men: group 1 consisted of eugonadal men (T>300 ng per 100 ml) evaluated for BPH, reproductive failure or sexual dysfunction; group 2 consisted of untreated hypogonadal men (T<300 ng per 100 ml); and group 3 comprised symptomatic hypogonadal men receiving TRT. Correlations were found between PSA (total and free fractions) and total serum testosterone levels among the three groups. Group 1: eugonadal men (n=385 patients), mean PSA and serum testosterone were 1.60 ng ml(-1) and 484 ng 100 ml, respectively. There was no significant correlation between PSA and total serum testosterone levels (r=-0.01, P=0.8). Group 2: untreated hypogonadal men (n=229 patients), mean PSA and serum testosterone were 1.49 ng ml(-1) and 269 ng per 100 ml, respectively. There was no significant correlation between PSA and total serum testosterone levels (r=0.03, P=0.6). Group 3: hypogonadal men on TRT (n=229 patients and 994 individual samples analyzed) mean PSA and serum testosterone were 1.50 ng ml(-1) and 555 ng per 100 ml, respectively. There was no significant correlation between PSA and serum testosterone levels (r=-0.005, P=0.9). Mean total serum testosterone levels were increased significantly (P<0.001) following treatment. Mean PSA levels did not increase in a statistically or clinically significant manner following TRT (mean PSA increase from baseline 0.05 ng ml(-1), P=0.6). In conclusion, TRT does not appear to significantly influence serum PSA expression and no significant correlation was identified between PSA and serum testosterone among eugonadal, untreated hypogonadal and hypogonadal men receiving TRT.

Association between indices of body mass and antibody titres to heat-shock protein-60, -65 and -70 in healthy Caucasians.

We have previously shown that antibody titres to several heat-shock proteins (Hsps) are elevated in dyslipidaemic patients and subjects with established vascular disease. Obesity is known to be associated with raised serum inflammatory markers suggesting a state of heightened immune activation. Hence, we have investigated the association between indices of obesity and several Hsp antibody titres in healthy subjects. Subjects (n=170) were recruited from among employees at the University of Surrey and the Royal Surrey County Hospital, Guildford, UK. Of these subjects, 35 were obese with a body mass index (BMI)>/=30 kg/m(2) (19 male and 16 female subjects), 58 were overweight with 30>BMI>/=25 kg/m(2) (36 male and 22 female subjects) and 77 were of a normal weight with BMI<25 kg/m(2) (31 male and 46 female subjects). Overall, obese subjects had significantly higher plasma anti-Hsp-60 (P<0.001), anti-Hsp-65 (P<0.05) and anti-Hsp-70 (P<0.05) compared with overweight and normal weight subjects.

The genetics of male infertility: a field of study whose time is now.

Idiopathic male infertility is often associated with genetic and epigenetic abnormalities. Such abnormalities include chromosome translocations and aneuploidies, Y chromosome microdeletions, and mutations of the CFTR gene. The unraveling of the human genome and ongoing animal transgenic studies have identified numerous other genes likely to be associated with male infertility. Initial reports from human studies have identified several candidate genes, including the protamine genes, SPO11, EIF5A2, USP26, ACT, and others. In addition to gene mutations and polymorphisms, damage to the chromatin resulting in single and double strand DNA breaks affects fertility. Recent studies are highlighting the role of such abnormalities in male infertility, and point to protamine defects as one cause of DNA damage. Epigenetic abnormalities also are being investigated, including the role of residual sperm mRNA in embryogenesis, and the effects of abnormal spermatogenesis on gene imprinting. These studies are pointing to complex etiologies and clinical ramifications in many infertile men.

Characterization of the putative cholesterol transport protein metastatic lymph node 64 in the brain.

Intracellular management of cholesterol is a critical process in the brain. Deficits with cholesterol transport and storage are linked to neurodegenerative disorders such as Neimann-Pick disease type C and Alzheimer's disease. One protein putatively involved in cholesterol transport is metastatic lymph node 64 (MLN64). MLN64 localizes to late endosomes which are part of the cholesterol internalization pathway. However, a detailed pattern of MLN64 expression in the brain is unclear. Using immunocytochemical and immunoblot analyses, we demonstrated the presence of MLN64 in several tissue types and various regions within the brain. MLN64 immunostaining in the CNS was heterogeneous, indicating selective expression in discrete specific cell populations and regions. MLN64 immunoreactivity was detected in glia and neurons, which displayed intracellular labeling consistent with an endosomal localization. Although previous studies suggested that MLN64 may promote steroid production in the brain, MLN64 immunoreactivity did not colocalize with steroidogenic cells in the CNS. These results demonstrate that MLN64 is produced in the mouse and human CNS in a restricted pattern of expression, suggesting that MLN64 serves a cell-specific function in cholesterol transport.

An SNP in protamine 1: a possible genetic cause of male infertility?

Gene targeting of the sperm nuclear proteins, the protamines, in mice leads to haploinsufficiency, abnormal chromatin compaction, sperm DNA damage, and male infertility. In order to investigate whether changes in amount or structure of the protamines could be a cause of human infertility, we sequenced the protamine genes of infertile men whose sperm appeared phenotypically similar to those of protamine deficient mice. We identified a heterozygous single nucleotide polymorphism (SNP) in the protamine (PRM1) gene in three infertile men (10% of the total infertile men analysed). This SNP disrupts one of the highly conserved arginine clusters needed for normal DNA binding. To rapidly screen for this SNP in infertile patients, we developed a simple PCR restriction fragment length polymorphism assay. This is the first report of a SNP in the PRM1 gene that appears associated with human male infertility.

Plasma antibody titres to heat shock proteins-60, -65 and-70: their relationship to coronary risk factors in dyslipidaemic patients and healthy individuals.

OBJECTIVE: To investigate the factors that may affect antibody titres to heat shock proteins (Hsp)-60, -65 and -70, and serum C-reactive protein (CRP) concentrations in patients with dyslipidaemia and other features of the metabolic syndrome as defined by ATPIII criteria. MATERIAL AND METHODS: The study comprised 237 dyslipidaemia patients and 135 healthy individuals recruited from amongst university and hospital employees. RESULTS: Compared to the healthy individuals, the dyslipidaemic patients had higher antibody titres to Hsp-60 (p<0.01), Hsp-65 (p<0.001) and Hsp-70 (p<0.05), and higher serum CRP concentrations (p<0.001). The best-fitting multifactorial models revealed that known coronary risk factors explained little of the variation in Hsp antibody titres: 3 % for Hsp-60, 1 % for Hsp-65 and 4 % for Hsp-70 amongst the dyslipidaemic subjects. The corresponding values for the subgroup with the metabolic syndrome were 8 %, 3 % and 1 %, respectively. In contrast, the best-fitting model explained 13.5 % of the variation in serum CRP concentrations among the dyslipidaemic patients, obesity being a major determinant; and 14 % in the subgroup with metabolic syndrome. CONCLUSIONS: The higher antibody titres to Hsp-60, -65, and -70 in the dyslipidaemic patients may be related to a heightened state of immunoactivation associated with atherosclerosis in this group. Our data indicate that antibody titres to these Hsps are not associated with the classical coronary risk factors, although serum high sensitivity (hs)CRP concentrations were significantly related to obesity.

Determinants of serum copper, zinc and selenium in healthy subjects.

BACKGROUND: We have investigated the association between serum copper, zinc and selenium concentrations, dietary intake, and demographic characteristics, including individual coronary risk factors, in healthy subjects. METHODS: Serum copper, zinc and selenium were measured by atomic absorption spectrometry in 189 healthy subjects. Serum glutathione peroxidase and caeruloplasmin were also determined for each subject. A previously validated food frequency questionnaire was used to estimate the dietary trace element intake. RESULTS: Male subjects had significantly lower serum copper (P<0.001) and caeruloplasmin (P<0.001), and higher serum zinc (P<0.05) and zinc:copper ratio (P<0.001) than female subjects. Significant differences were observed in serum copper and caeruloplasmin concentrations (P<0.01) with age. Weak but significant associations between dietary trace elements and their serum concentrations were observed for zinc (r=0.18, P=0.02), copper (r=0.17, P=0.03) and selenium (r=0.19, P=0.02). Obese subjects had significantly lower serum concentrations of zinc (P<0.05). In multifactorial analysis, dietary zinc (P<0.05), serum high-density lipoprotein-cholesterol (HDL-C) (P<0.05), diastolic blood pressure (P<0.05) and age (P=0.05) emerged as major predictors of serum zinc concentrations. The corresponding predictors for serum copper were C-reactive protein (CRP) (P<0.001), serum HDL-C (P<0.001), gender (P=0.01), physical activity levels (P<0.05) and dietary copper (P<0.05). Serum selenium concentrations were predicted by serum total cholesterol (P<0.01), serum CRP concentrations (P<0.05) and dietary selenium (P<0.03). CONCLUSION: Serum copper, zinc and selenium concentrations are influenced by physiological conditions such as age, diet and gender. Their serum concentrations are also associated with coronary risk factors, including body mass index, levels of physical activity, serum HDL-C and CRP.

Palatal discrepancies and postdams.

To investigate the variation in post-cure palatal discrepancy of dentures, 20 complete maxillary replica dentures were prepared on models with high and low palates and processed by conventional compression moulding and injection moulding. Measurements were made by travelling microscope of the sagittal midline discrepancies between palate and model on three occasions; after processing; after removal of part of the investing plaster; and after immersion in water for 1 month at 37 degrees C. The magnitudes of discrepancies were greatest distally, diminishing with distance anteriorly from the postdam. They increased with partial removal of plaster, and decreased slightly after immersion.

Heat shock protein antibody titers are reduced by statin therapy in dyslipidemic subjects: a pilot study.

Antibody titers to heat shock protein (Hsp)-60 and -65 are positively related to risk of vascular disease and cardiovascular endpoints. There are few data on the factors that regulate the levels of these antibodies. It is known that the statins have antiinflammatory and immunoregulatory properties. The authors examined the effects of 2 statins, simvastatin (Zocor) and atorvastatin (Lipitor) on antibody titers to Hsp-60, -65, and -70 in a group of dyslipidemic patients. Twenty patients attending a lipid clinic, and previously not receiving lipid-lowering treatment, were treated with 10 mg of simvastatin (n = 11) or atorvastatin (n = 9) for 4 months. An additional 14 patients were recruited from the same clinic at the same hospital as a control group. The medication of these latter patients was unaltered for 4 months and the same parameters were measured as for the statin group. Antibody titers to Hsp-60, -65, and -70 were measured by enzyme-linked immunosorbent assay and lipoprotein profile and highly sensitive serum C-reactive protein (CRP) were measured by routine methods before and after treatment. Pretreatment and posttreatment data were compared by paired t or Mann-Whitney tests. Overall statin treatment was associated with a significant reduction in median antibody titers to Hsp-60 (17.2%, p = 0.03), Hsp-65 (15.9%, p = 0.003) and Hsp-70 (8.3%, p = 0.006), but not in control patients. Both statins caused a reduction in median serum CRP concentrations (45% overall, p < 0.05), but significant changes were not observed in the control patients. The effects on Hsp antibody titers were not related to changes in serum CRP concentrations (p > 0.05). However, there was a significant correlation between changes in antibody titers to Hsp-60 vs Hsp-65 (p < 0.01), Hsp-60 vs Hsp-70 (p < 0.05), and Hsp-65 vs Hsp-70 (p < 0.001). Statin treatment was associated with a reduction in antibody titers to Hsp-60, -65, and -70. This reduction is not fully explained by the antiinflammatory effects of the statins but may be due to their other immunomodulatory properties.

What does the lipoprotein oxidation phenomenon mean?

The evidence that oxidative lipid modification may be involved in the genesis of common diseases, such as atherosclerosis, is persuasive, but it was, until recently, conjecture based on in vitro findings, or investigation using experimental animal models. Recent clinical intervention studies in patients at high risk of cardiovascular events have been, at best, inconclusive. This has led to a general consensus that antioxidant supplements are of no value in the prevention of cardiovascular disease in subjects at high risk. However, epidemiological studies have demonstrated that the protective effects of antioxidant supplements, specifically vitamin E, were particularly evident amongst healthy subjects taking supplements. The picture is further clouded by the uncertain mechanism of lipoprotein modification within the artery wall, the possibility that some antioxidants may, under certain conditions, become pro-oxidants, the complex interactions between lipid- and water-soluble antioxidants, and the fact that free-radical-mediated events may only be important in the early stages of atherogenesis. Recent results also suggest that the biological efficacy of antioxidants, such as alpha-tocopherol, may be compromised by the conditions extant within the plaque. It is evidently important that the position on the benefits of antioxidants, whether in food or as supplements, in disease prevention is clarified.

Microsatellite instability and defects in mismatch repair proteins: a new aetiology for Sertoli cell-only syndrome.

Microsatellite instability is characteristic of certain types of cancer, and is present in rodents lacking specific DNA mismatch repair proteins. These azoospermic mice exhibit spermatogenic defects similar to some human testicular failure patients. Therefore, we hypothesized that microsatellite instability due to deficiencies in mismatch repair genes might be an unrecognized aetiology of human testicular failure. Because these azoospermic patients are candidates for testicular sperm extraction and ICSI, transmission of mismatch repair defects to the offspring is possible. Seven microsatellite loci were analysed for instability in specimens from 41 testicular failure patients and 20 controls. Blood and testicular DNA were extracted from patient and control specimens, and amplified by PCR targeting seven microsatellite loci. DNA fragment length was analysed with an ABI Prism 310 Genotyping Machine and GeneScan software. Immunohistochemistry was performed on paraffinized testis biopsy sections and cultured testicular fibroblasts from each patient to determine if expression of the mismatch repair proteins hMSH2 and hMLH1 was normal in both somatic and germline cells. Results demonstrate that microsatellite instability and DNA mismatch repair protein defects are present in some azoospermic men, predominantly in Sertoli cell-only patients (P < 0.01 and P < 0.05 respectively). This provides evidence of a previously unrecognized aetiology of testicular failure that may be associated with cancer predisposition.

Modification of natural and artificial polymer colloids by "topology-controlled" emulsion polymerization.

A diffuse layer of water-soluble polymer chemically grafted to the surface of a hydrophobic polymer colloid has been created by the second-stage polymerization of dimethylaminoethyl methacrylate (DMAEMA) onto the biomacromolecule polyisoprene in natural rubber latex and also onto synthetic polybutadiene and polystyrene latexes. To control the locus of radical formation, the process was initiated by a redox couple wherein one component (e.g., cumene hydroperoxide) is hydrophobic and the other (e.g., tetraethylenepentamine) is hydrophilic. The modified latexes displayed a dramatic increase in colloidal stability at low pH which is attributed to grafted hydrophilic polymer acting as an electrosteric stabilizer; the effect is particularly remarkable in natural rubber latex, which usually has poor colloidal stability for pH less, similar 8. (13)C NMR was performed to verify the existence of the grafted copolymer and to quantify yield. The mechanism by which such a novel morphology can be generated is postulated to be via a process of radical formation at the particle surface followed by the subsequent grafting to the hydrophobic polymer backbone and polymerization of hydrophilic monomer in the aqueous phase. This technique is potentially useful for creating novel materials from natural rubber latex.

Biphasic modulation of atherosclerosis induced by graded dietary copper supplementation in the cholesterol-fed rabbit.

There has been considerable debate about how copper status may affect the biochemical and cellular processes associated with atherogenesis. We have investigated the effects of graded dietary copper supplementation on processes likely to contribute to atherogenesis, using the cholesterol-fed New Zealand White rabbit model. Rabbits (n = 40) were fed a 0.25-1% cholesterol diet deficient in copper. Animals received either 0, 1, 3 or 20 mg copper/day and were killed after 13 weeks. Plasma cholesterol levels were similar in each dietary group. Aortic concentrations of copper were higher in the 20 mg copper/day animals compared to those receiving 0 mg copper/day (3.70 +/- 0.78 vs. 1.33 +/- 0.46 microg/g wet tissue; P < 0.05). Aortic superoxide dismutase activity was higher in animals receiving 20 mg copper/day (323 +/- 21 IU/mg tissue) compared to the other groups (187 +/- 21; 239 +/- 53; 201 +/- 33 IU/mg tissue) (P > 0.05). En face staining of aortae with oil red O showed that both high copper supplementation (20 mg/day) (67.1 +/- 5.5%) and a deficient diet (0 mg/day) (63.1 +/- 4.8%) was associated with significantly larger lesions (P < 0.05) compared to moderately supplemented animals (1 mg/day and 3 mg/day) (51.3 +/- 6.3 and 42.8 +/- 7.9%). These data indicate that in the cholesterol-fed rabbit, there is an optimal dietary copper intake and that dietary copper deficiency or excess are associated with an increased susceptibility to aortic atherosclerosis. Many Western diets contain insufficient copper and these findings indicate that a moderate dietary copper content may confer a degree of cardiac protection to the human population.