NLRP1 haplotypes associated with vitiligo and autoimmunity increase interleukin-1ß processing via the NLRP1 inflammasome.

Nuclear localization leucine-rich-repeat protein 1 (NLRP1) is a key regulator of the innate immune system, particularly in the skin where, in response to molecular triggers such as pathogen-associated or damage-associated molecular patterns, the NLRP1 inflammasome promotes caspase-1-dependent processing of bioactive interleukin-1ß (IL-1ß), resulting in IL-1ß secretion and downstream inflammatory responses. NLRP1 is genetically associated with risk of several autoimmune diseases including generalized vitiligo, Addison disease, type 1 diabetes, rheumatoid arthritis, and others. Here we identify a repertoire of variation in NLRP1 by deep DNA resequencing. Predicted functional variations in NLRP1 reside in several common high-risk haplotypes that differ from the reference by multiple nonsynonymous substitutions. The haplotypes that are high risk for disease share two substitutions, L155H and M1184V, and are inherited largely intact due to extensive linkage disequilibrium across the region. Functionally, we found that peripheral blood monocytes from healthy subjects homozygous for the predominant high-risk haplotype 2A processed significantly greater (P < 0.0001) amounts of the IL-1ß precursor to mature bioactive IL-1ß under basal (resting) conditions and in response to Toll-like receptor (TLR) agonists (TLR2 and TLR4) compared with monocytes from subjects homozygous for the reference haplotype 1. The increase in basal release was 1.8-fold greater in haplotype 2A monocytes, and these differences between the two haplotypes were consistently observed three times over a 3-mo period; no differences were observed for IL-1α or TNFα. NLRP1 RNA and protein levels were not altered by the predominant high-risk haplotype, indicating that altered function of the corresponding multivariant NLRP1 polypeptide predisposes to autoimmune diseases by activation of the NLRP1 inflammasome.

Serum uric acid levels predict the development of albuminuria over 6 years in patients with type 1 diabetes: findings from the Coronary Artery Calcification in Type 1 Diabetes study.

BACKGROUND: Recent studies suggest that uric acid is a mediator of diabetic nephropathy. We hypothesized that elevated serum uric acid levels are a strong predictor of albuminuria in patients with type 1 diabetes. METHODS: We analyzed data from the Coronary Artery Calcification in Type 1 Diabetes study, a prospective observational study. A stepwise logistic regression model was applied to predict the development of micro- or macroalbuminuria after 6 years of follow-up in 324 participants who had no evidence of micro- or macroalbuminuria at baseline. A P-value <0.1 was used as the criteria for entry into and removal from the model. RESULTS: The following factors were selected in the stepwise multivariate model as predictors of micro- or macroalbuminuria at the 6-year follow-up visit: baseline serum uric acid levels, HbA(1c) and pre-albuminuria. For every 1-mg/dl increase in serum uric acid levels at baseline, there was an 80% increased risk of developing micro- or macroalbuminuria at 6 years (odds ratio 1.8; 95% confidence interval 1.2, 2.8; P = 0.005). Additional covariates considered in the stepwise model were sex, age, duration of diabetes, angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker treatment, waist circumference, waist/hip ratio, body mass index, systolic and diastolic blood pressure, smoking, serum creatinine, cystatin C, high-density lipoprotein cholesterol and triglycerides. CONCLUSION: Elevated serum uric acid levels are a strong predictor of the development of albuminuria in patients with type 1 diabetes.

PROFILE PD: profile of function and impairment level experience with Parkinson disease--clinimetric properties of a rating scale for physical therapist practice.

BACKGROUND AND PURPOSE: Individuals with Parkinson disease (PD) experience a range of deficits of body systems and activities. A clinical test is needed that is reliable, valid, applicable to physical therapist practice, and appropriate for use in early and mid-stages of the disease. PROFILE PD is one such scale, consisting of 24 items that would typically be assessed during the physical therapist's examination and evaluation of individuals with PD. The purpose of this article is to report on clinimetric properties of the PROFILE PD and to make the test available for use. METHODS: Interrater reliability was determined using the intraclass correlation coefficient. Construct validity was determined by comparing scores on the PROFILE PD with the gold standard (Unified Parkinson's Disease Rating Scale [UPDRS]) as well as scales of physical activity and participation. Construct validity and structure of the PROFILE PD were further examined using exploratory factor analysis using principal component analysis with Promax rotation that allows a correlated factor structure. RESULTS: Interrater reliability of the PROFILE PD was high (ICC = 0.97). Construct validity was demonstrated with the UPDRS (r = 0.86, P < 0.0001), Schwab & England Activities of Daily Living Scale (S&E) (r = -0.83, P < 0.0001), and Continuous Scale Physical Functional Performance test (r = -0.62, P < 0.0001). Principal component analysis demonstrated that the test comprises a single scale. CONCLUSIONS: The PROFILE PD is a reliable and valid scale that can be used to quantify alterations in body systems and activity of individuals in early and mid-stages of PD. Use of the scale can provide an overall summary of the impact of PD on body systems and activities.

Human prostate stromal cells stimulate increased PSA production in DHEA-treated prostate cancer epithelial cells.

Dehydroepiandrosterone (DHEA) is commonly used as a dietary supplement and may affect prostate pathophysiology when metabolized to androgens and/or estrogens. Human prostate LAPC-4 cancer cells with a wild type androgen receptor (AR) were treated with DHEA, androgens dihydrotestosterone (DHT), T, or R1881), and E2 and assayed for prostate specific antigen (PSA) protein and gene expression. In LAPC-4 monocultures, DHEA and E2 induced little or no increase in PSA protein or mRNA expression compared to androgen-treated cells. When prostate cancer-associated (6S) stromal cells were added in coculture, DHEA stimulated LAPC-4 cell PSA protein secretion to levels approaching induction by DHT. Also, DHEA induced 15-fold more PSA mRNA in LAPC-4 cocultures than in monocultures. LAPC-4 proliferation was increased 2-3-fold when cocultured with 6S stromal cells regardless of hormone treatment. DHEA-treated 6S stromal cells exhibited a dose- and time-dependent increase in T secretion, demonstrating stromal cell metabolism of DHEA to T. Coculture with non-cancerous stroma did not induce LAPC-4 PSA production, suggesting a differential modulation of DHEA effect in a cancer-associated prostate stromal environment. This coculture model provides a research approach to reveal detailed endocrine, intracrine, and paracrine signaling between stromal and epithelial cells that regulate tissue homeostasis within the prostate, and the role of the tumor microenvironment in cancer progression.

Monoamine oxidase-A is a major target gene for glucocorticoids in human skeletal muscle cells.

Skeletal myopathy is a common complication of endogenous and exogenous glucocorticoid excess, yet its pathogenetic mechanisms remain unclear. There is accumulating evidence that mitochondrial dysfunction and oxidative stress are involved in this process. To explore the glucocorticoid-induced transcriptional adaptations that may affect mitochondrial function in skeletal muscle, we studied gene expression profiles in dexamethasone-treated primary human skeletal myocytes using a cDNA microarray, which contains 501 mitochondria-related genes. We found that monoamine oxidase A (MAO-A) was the most significantly up-regulated gene. MAO-A is the primary enzyme metabolizing catecholamines and dietary amines, and its role in skeletal muscle remains largely unexplored. Dexamethasone induced dose- and time-dependent increases of MAO-A gene and protein expression, while its effects on MAO-B were minimal. Both the glucocorticoid receptor (GR) and the Sp1 transcription factor were required for dexamethasone-induced MAO-A mRNA expression, as blockade of the GR with RU 486 or ablation of Sp1 binding with mithramycin abrogated MAO-A mRNA induction. The observed dexamethasone effect was biologically functional, as this steroid significantly increased MAO-mediated hydrogen peroxide production. We suggest that MAO-A-mediated oxidative stress can lead to cell damage, representing a novel pathogenetic mechanism for glucocorticoid-induced myopathy and a potential target for therapeutic intervention.

Serum uric acid and hypertension in adults: a paradoxical relationship in type 1 diabetes.

Adults with type 1 diabetes have lower serum uric acid levels compared with nondiabetic adults. Little is known about the relationship between serum uric acid and blood pressure in type 1 diabetes and whether it differs from the positive relationship found in nondiabetic adults. The authors assessed the cross-sectional and longitudinal relationships over 6 years between serum uric acid and blood pressure in adults with (35±9 years [n=393]) and without (38±9 years [n=685]) type 1 diabetes in the Coronary Artery Calcification in Type 1 Diabetes study. In nondiabetic adults, serum uric acid was associated with systolic blood pressure in multivariable models adjusted for cardiovascular risk factors. In adults with type 1 diabetes, a negative association was observed between serum uric acid and systolic blood pressure after multivariable adjustments. A positive association was observed between serum uric acid and systolic blood pressure in nondiabetic adults. In contrast, an inverse relationship was demonstrated after multivariable adjustments in type 1 diabetes.

Serum uric acid and insulin sensitivity in adolescents and adults with and without type 1 diabetes.

HYPOTHESIS: Decreased insulin sensitivity (IS) exists in type 1 diabetes. Serum uric acid (SUA), whose concentration is related to renal clearance, predicts vascular complications in type 1 diabetes. SUA is also inversely associated with IS in non-diabetics, but has not been examined in type 1 diabetes. We hypothesized SUA would be associated with reduced IS in adolescents and adults with type 1 diabetes. METHODS: The cross-sectional and longitudinal associations of SUA with IS were investigated in 254 adolescents with type 1 diabetes and 70 without in the Determinants of Macrovascular Disease in Adolescents with Type 1 Diabetes Study, and in 471 adults with type 1 diabetes and 571 without in the Coronary Artery Calcification in Type 1 diabetes (CACTI) study. RESULTS: SUA was lower in subjects with type 1 diabetes (p<0.0001), but still remained inversely associated with IS after multivariable adjustments in adolescents (ß±SE: -1.99±0.62, p=0.001, R2 =2%) and adults (ß±SE: -0.91±0.33, p=0.006, R2 = 6%) with type 1 diabetes, though less strongly than in non-diabetic controls (adolescents: ß±SE: -2.70±1.19, p=0.03, R2 = 15%, adults: ß±SE: -5.99±0.75, p<0.0001, R2 =39%). CONCLUSION: We demonstrated a significantly weaker relationship between SUA and reduced IS in subjects with type 1 diabetes than non-diabetic controls.

Effect of statin and angiotensin-converting enzyme inhibition on structural and hemodynamic alterations in autosomal dominant polycystic kidney disease model.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common life-threatening hereditary disease and is the fourth most common cause of end-stage kidney disease. Preclinical studies to identify effective interventions to prevent or slow progression of PKD nephropathy are therefore direly needed. Heterozygous Han:SPRD rats are an autosomal dominant PKD model with many of the characteristics of ADPKD in humans. In the present study, parameters known to antedate the decrease in renal function, namely, renal structure, renal blood flow (RBF), and mean arterial pressure (MAP), were evaluated with three different interventions, namely, HMG-CoA reductase inhibition with lovastatin, angiotensin-converting enzyme (ACE) inhibition with enalapril, and a combination of these two treatments. The statin therapy demonstrated structural and functional benefits, including increased RBF and decreased BUN, independently of a change in MAP, while the ACE inhibition therapy demonstrated structural benefit in association with a decrease in MAP. An enhancement of these protective interventions in this autosomal dominant PKD model was not demonstrated with the combined treatment.

Androgen receptor or estrogen receptor-beta blockade alters DHEA-, DHT-, and E(2)-induced proliferation and PSA production in human prostate cancer cells.

BACKGROUND: Dehydroepiandrosterone (DHEA) is an endogenous steroid that is metabolized to androgens and/or estrogens in the human prostate. DHEA levels decline with age, and use of DHEA supplements to retard the aging process is of unproved effectiveness and safety. LNCaP and LAPC-4 prostate cancer cells were used to determine whether DHEA-modulated proliferation and prostate specific antigen (PSA) production were mediated via the androgen receptor (AR) and/or ERbeta. METHODS: Cells were treated with DHEA, DHT, or E(2) and antagonists to AR (Casodex-bicalutamide) or ER (ICI 182,780) or siRNA to the respective receptors. Proliferation was assessed by MTT assay and PSA mRNA and protein secretion were measured by quantitative real-time PCR and ELISA. Associations of AR and ERbeta were analyzed by co-immunoprecipitation studies and fluorescent confocal microscopy. RESULTS: DHEA-, T-, and E(2)-induced proliferation of LNCaP cells was blunted by Casodex but not by ICI treatment. In LNCaP cells, Casodex and ICI suppressed hormone-induced PSA production. In LAPC-4 cells, DHT-stimulated PSA mRNA was inhibited by Casodex and ICI, and the minimal stimulation by DHEA was inhibited by ICI. Use of siRNAs confirmed involvement of AR and ERbeta in hormone-induced PSA production while AR-ERbeta co-association was suggested by immunoprecipitation and nuclear co-localization. CONCLUSIONS: These findings support involvement of both AR and ERbeta in mediating DHEA-, DHT-, and E(2)-induced PSA expression in prostate cancer cells.

DHT and testosterone, but not DHEA or E2, differentially modulate IGF-I, IGFBP-2, and IGFBP-3 in human prostatic stromal cells.

Prostate cancer is one of the four most common cancers in the United States, affecting one of six men. Increased serum levels of androgens and IGF-I are associated with an augmented risk of prostate cancer. Dihydrotestosterone (DHT) and testosterone (T) stimulate prostate cancer cell growth, development, and function, whereas the effects of DHT and T in prostate stromal cells, and of dehydroepiandrosterone (DHEA) in prostate cancer or stromal cells, are uncertain. We investigated the actions of DHT, T, DHEA, and estradiol (E2) on insulin-like growth factor (IGF)-I, IGF-II, IGF-I receptor (R), IGF-binding protein (IGFBP)-2, IGFBP-3, and IGFBP-5 in primary cultures of human prostatic stromal cells by assessing cell proliferation, mRNA expression, and protein secretion by MTT growth assay, quantitative real-time PCR, and ELISA, respectively. DHT and T each increased IGF-I (7-fold) and decreased IGFBP-3 (2-fold) mRNA expression and protein secretion in a dose- and time-dependent manner and increased IGFBP-2 (2-fold) mRNA in a dose- and time-dependent manner. DHEA and E2 did not significantly alter these measures. Flutamide abolished the DHT-modulated increases in IGF-I and IGFBP-2, suggesting that the influences of DHT and T on these measures were androgen receptor mediated. None of the four steroids significantly affected IGF-IR, IGF-II, or IGFBP-5 mRNA levels or stromal cell proliferation. The effects of DHT on IGF-I, IGFBP-2, and IGFBP-3 were more pronounced in stromal cultures that did not express desmin. These data suggest that DHT and T promote prostate growth partly via modulation of the stromal cell IGF axis, with potential paracrine effects on prostate epithelial cells.

Comparative effects of DHEA vs. testosterone, dihydrotestosterone, and estradiol on proliferation and gene expression in human LNCaP prostate cancer cells.

Serum levels of the adrenal androgen dehydroepiandrosterone (DHEA) peak in men and women in the third decade of life and decrease progressively with age. Increasing numbers of middle-aged and older individuals consume over-the-counter preparations of DHEA, hoping it will retard aging by increasing muscle and bone mass and strength, decreasing fat, and improving immunologic and neurobehavioral functions. Because DHEA can serve as a precursor to more potent androgens and estrogens, like testosterone (T), dihydrotestosterone (DHT), and 17beta-estradiol (E2), supplemental DHEA use may pose a cancer risk in patients with nascent or occult prostate cancer. The steroid-responsive human LNCaP prostate cancer cells, containing a functional but mutated androgen receptor (AR), were used to compare effects of DHEA with those of T, DHT, and E2 on cell proliferation and protein and/or gene expression of AR, prostate-specific antigen (PSA), IGF-I, IGF-I receptor (IGF-IR), IGF-II, IGF-binding proteins-2, -3, and -5, (IGFBPs-2, -3, and -5), and estrogen receptor-beta (ERbeta). Cell proliferation assays revealed significant stimulation by all four steroids. DHEA- and E2-induced responses were similar but delayed and reduced compared with that of T and DHT. All four hormones increased gene and/or protein expression of PSA, IGF-IR, IGF-I, and IGFBP-2 and decreased that of AR, ERbeta, IGF-II, and IGFBP-3. There were no significant effects of hormone treatment on IGFBP-5 mRNA. DHEA and E2 responses were similar, and distinct from those of DHT and T, in time- and dose-dependent studies. Further studies of the mechanisms of DHEA effects on prostate cancer epithelial cells of varying AR status, as well as on prostate stromal cells, will be required to discern the implications of DHEA supplementation on prostatic health.

Modifier genes play a significant role in the phenotypic expression of PKD1.

BACKGROUND: Polycystic kidney disease type 1 (PKD1) is characterized by extreme variation in the severity and progression of renal and extrarenal phenotypes. There are significant familial phenotype differences; but it is not clear if this is due to differences in PKD1 mutations, differences in genetic background, or both. METHODS: A total of 315 affected relatives (83 PKD1 families) without end-stage renal disease (ESRD) were evaluated for disease markers, including renal volume, creatinine clearance, proteinuria, liver cysts, and hypertension. Of these patients, 19% progressed to ESRD within 1 to 10 years after the initial examination. Nested analysis of variance was used to investigate interfamilial and intrafamilial differences in these phenotypes. Heritability analyses were used to estimate the effect of the genetic background on phenotypic variability. The age of onset of ESRD was also analyzed with an additional 389 family members from the same PKD1 families without clinical evaluation but with data on age of onset of ESRD (or age without ESRD). RESULTS: There were significant phenotype differences between patients with the same mutation and different genetic backgrounds. The phenotypic variation between patients with different mutations and different genetic backgrounds was not significantly greater than the variation between patients with the same mutation and different genetic backgrounds. However, when the 389 family members were included, both the mutation and modifier genes had significant effects on the age of onset of ESRD. Inherited differences in genetic background were estimated to account for 18% to 59% of the phenotypic variability in PKD1 disease markers in patients prior to ESRD and in the subsequent progression to ESRD (43% heritability) in the 315 patients who were clinically evaluated. CONCLUSION: Modifier loci in the genetic background are important factors in inter- and intrafamilial variability in the phenotypic expression of PKD1. The extreme intrafamilial phenotype differences are consistent with the hypothesis that one or a few modifier genes have a major effect on the progression and severity of PKD1.

Epidemiological study of kidney survival in autosomal dominant polycystic kidney disease.

BACKGROUND: It is unknown whether the substantial increase in research, identification of risk factors for renal progression, greater antihypertensive armamentarium including inhibitors of the renin-angiotensin-aldosterone system (RAAS) and enhanced educational information have impacted the progression of autosomal dominant polycystic kidney disease (ADPKD) renal disease. METHODS: An epidemiological study involving 513 ADPKD subjects was performed. The hypothesis tested was that over two separate periods, 1985 to 1992 versus 1992 to 2001, a significant slowing of renal function loss in ADPKD patients would be demonstrated in association with improved blood pressure (BP) control and inhibition of the RAAS as instituted by their primary care physicians. RESULTS: ADPKD males and females in the later cohort (1992 to 2001) had longer mean and median survival times to ESRD than males and females in the earlier cohort (1985 to 1992). Analysis revealed that both males and females in the later cohort had significantly lower diastolic blood pressure (DBP) and mean arterial pressure (MAP) values than males and females in the earlier cohort. ADPKD male and female patients in the later cohort used significantly more angiotensin converting enzyme inhibitors (ACEIs) than ADPKD male and female patients in the earlier cohort. CONCLUSIONS: These results demonstrate a significant slowing of ADPKD renal progression in both male and female patients that was associated with a significantly lower MAP and increased use of ACEIs in the later cohort (1992 to 2001) as compared to the early cohort (1985-1992).

No effect of angiotensin-converting enzyme gene polymorphism on disease progression and left ventricular hypertrophy in autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) shows a variable clinical course suggesting that genetic modifiers might play a role. There are conflicting results about the effect of angiotensin-converting enzyme (ACE) gene polymorphism on the progression of renal failure in ADPKD. Also, the association between ACE gene polymorphism and the occurrence of left ventricular hypertrophy (LVH) has not been investigated in patients with ADPKD. METHODS: ACE genotype analysis was performed in 409 Caucasian patients (137 male, 272 female) with ADPKD. Echocardiographic examination was done in 164 of these patients. RESULTS: There were no significant differences between different ACE genotypes regarding renal function, renal volume, urinary protein excretion, blood pressure, the rate of hypertension, the age at diagnosis of hypertension, the rate of LVH and the incidence of end-stage renal disease (ESRD). CONCLUSION: ACE gene polymorphism does not have a significant effect on the development of ESRD and the prevalence of LVH in patients with ADPKD.

Cardiac and renal effects of standard versus rigorous blood pressure control in autosomal-dominant polycystic kidney disease: results of a seven-year prospective randomized study.

This study sought to investigate the cardiac and renal effects of rigorous versus standard BP control on autosomal-dominant polycystic kidney disease (ADPKD). A prospective, randomized, 7-yr study was performed to examine the effect of rigorous (<120/80 mmHg) versus standard (135-140/85-90 mmHg) BP control on left ventricular mass index (LVMI) and kidney function in 75 hypertensive ADPKD patients with left ventricular hypertrophy. LVMI was measured by echocardiogram at baseline and at 1 and 7 yr. Renal function was assessed by measuring serum creatinine and 24-h creatinine clearance every 6 mo for 3 yr, then annually for an additional 4 yr. The baseline characteristics were comparable in the two groups. During the study, average mean arterial pressure was 90 +/- 5 mmHg for the rigorous group and 101 +/- 4 mmHg for the standard group (P < 0.0001). The LVMI decreased by 21% in the standard group and by 35% in the rigorous group. A mixed model longitudinal data analysis revealed that rigorous BP control was significantly more effective in decreasing LVMI (P < 0.01). There was no statistically significant difference in renal function between the two groups. In conclusion, left ventricular hypertrophy, a major cardiovascular risk factor, was decreased to a significantly greater extent by rigorous than standard BP control. This finding has particular clinical importance because cardiovascular complications are the most common cause of death in ADPKD patients.