The critical role of neutral cholesterol ester hydrolase 1 in cholesterol removal from human macrophages.

RATIONALE: Hydrolysis of intracellular cholesterol ester (CE) is the key step in the reverse cholesterol transport in macrophage foam cells. We have recently shown that neutral cholesterol ester hydrolase (Nceh)1 and hormone-sensitive lipase (Lipe) are key regulators of this process in mouse macrophages. However, it remains unknown which enzyme is critical in human macrophages and atherosclerosis. OBJECTIVE: We aimed to identify the enzyme responsible for the CE hydrolysis in human macrophages and to determine its expression in human atherosclerosis. METHODS AND RESULTS: We compared the expression of NCEH1, LIPE, and cholesterol ester hydrolase (CES1) in human monocyte-derived macrophages (HMMs) and examined the effects of inhibition or overexpression of each enzyme in the cholesterol trafficking. The pattern of expression of NCEH1 was similar to that of neutral CE hydrolase activity during the differentiation of HMMs. Overexpression of human NCEH1 increased the hydrolysis of CE, thereby stimulating cholesterol mobilization from THP-1 macrophages. Knockdown of NCEH1 specifically reduced the neutral CE hydrolase activity. Pharmacological inhibition of NCEH1 also increased the cellular CE in HMMs. In contrast, LIPE was barely detectable in HMMs, and its inhibition did not decrease neutral CE hydrolase activity. Neither overexpression nor knockdown of CES1 affected the neutral CE hydrolase activity. NCEH1 was expressed in CD68-positive macrophage foam cells of human atherosclerotic lesions. CONCLUSIONS: NCEH1 is expressed in human atheromatous lesions, where it plays a critical role in the hydrolysis of CE in human macrophage foam cells, thereby contributing to the initial part of reverse cholesterol transport in human atherosclerosis.

Adipose triglyceride lipase in human skeletal muscle is upregulated by exercise training.

Mobilization of fatty acids from stored triacylglycerol (TG) in adipose tissue and skeletal muscle [intramyocellular triacylglycerol (IMTG)] requires activity of lipases. Although exercise training increases the lipolytic capacity of skeletal muscle, the expression of hormone-sensitive lipase (HSL) is not changed. Recently, adipose triglyceride lipase (ATGL) was identified as a TG-specific lipase in various rodent tissues. To investigate whether human skeletal muscle ATGL protein is regulated by endurance exercise training, 10 healthy young men completed 8 wk of supervised endurance exercise training. Western blotting analysis on lysates of skeletal muscle biopsy samples revealed that exercise training induced a twofold increase in skeletal muscle ATGL protein content. In contrast to ATGL, expression of comparative gene identification 58 (CGI-58), the activating protein of ATGL, and HSL protein was not significantly changed after the training period. The IMTG concentration was significantly decreased by 28% at termination of the training program compared with before. HSL-phoshorylation at Ser(660) was increased, HSL-Ser(659) phosporylation was unchanged, and HSL-phoshorylation at Ser(565) was decreased altogether, indicating an enhanced basal activity of this lipase. No change was found in the expression of diacylglycerol acyl transferase 1 (DGAT1) after training. Inhibition of HSL with a monospecific, small molecule inhibitor (76-0079) and stimulation of ATGL with CGI-58 revealed that significant ATGL activity is present in human skeletal muscle. These results suggest that ATGL in addition to HSL may be important for human skeletal muscle lipolysis.

A Pocket-size Device to Detect Autonomic Neuropathy.

BACKGROUND: Diabetic autonomic neuropathy (DAN) is a very frequent complication in the diabetic population (type 1 and type 2 diabetes), and patients may suffer debilitating symptoms from various organ systems. In the less symptomatic and even in the asymptomatic condition it severely impacts health. Testing for DAN is currently time-consuming and costly due to the technical setups available today, therefore the examination may not be offered regularly. The purpose of this study was to evaluate the clinical performance of a pocket-size device for detecting DAN by measuring heart rate variability (HRV). METHOD: Ten healthy young males and eight type 1 diabetes patients suffering symptomatic DAN were selected. The standardized spectral analysis equipment VariaPulse TF3 (Sima Media, Olumouc, Czechoslovakia) was used as a reference method for evaluating a prototype of the pocket-size device according to a specified protocol. HRV, inhalation/exhalation ratio (E:I) (deep breathing test), and 30:15 ratio (response going from lying to standing) were measured using both methods. Statistical calculations were performed. RESULTS: The correlation between the two devices was R(2) = 0.98 and R(2) = 0.81 when 30:15 ratio and E:I were measured, respectively. Bland-Altman plots showed suitable agreement between the two devices, substantiated by 95% limits of agreement of the differences of +/-0.014 and +/-0.033 when 30:15 ratio and E:I were measured, respectively. CONCLUSIONS: The pocket-size device was fully interchangeable with the hitherto-used, research-based setup. It proved highly suitable for ambulatory testing of autonomic nervous function and may facilitate screening for DAN according to Danish and international recommendations.

Synthesis and structure-activity relationship for a novel class of potent and selective carbamate-based inhibitors of hormone selective lipase with acute in vivo antilipolytic effects.

Hormone-sensitive lipase (HSL) is an intracellular enzyme that has a central role in the regulation of fatty acid metabolism. The enzyme, therefore, is a potentially interesting pharmacological target for the treatment of insulin resistance and dyslipidemic disorders. Based on a high throughput screening, a carbamate based HSL inhibitor was identified and optimized into the selective HSL inhibitors 4-hydroxymethyl-piperidine-1-carboxylic acid 4-(5-trifluoromethylpyridin-2-yloxy)-phenyl ester (13f) and 4-hydroxy-piperidine-1-carboxylic acid 4-(5-trifluoromethylpyridin-2-yloxy)-phenyl ester (13g), with IC50 values of 110 and 500 nM, respectively. Both inhibitors were active in acute antilipolytic experiments in vivo and none of the inhibitors inhibited the cytochrome P450 (CYP) isoforms 2D6, 3A4, and 1A2.

Adipose triglyceride lipase and hormone-sensitive lipase are the major enzymes in adipose tissue triacylglycerol catabolism.

The mobilization of free fatty acids from adipose triacylglycerol (TG) stores requires the activities of triacylglycerol lipases. In this study, we demonstrate that adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) are the major enzymes contributing to TG breakdown in in vitro assays and in organ cultures of murine white adipose tissue (WAT). To differentiate between ATGL- and HSL-specific activities in cytosolic preparations of WAT and to determine the relative contribution of these TG hydrolases to the lipolytic catabolism of fat, mutant mouse models lacking ATGL or HSL and a mono-specific, small molecule inhibitor for HSL (76-0079) were used. We show that 76-0079 had no effect on TG catabolism in HSL-deficient WAT but, in contrast, essentially abolished free fatty acid mobilization in ATGL-deficient fat. CGI-58, a recently identified coactivator of ATGL, stimulates TG hydrolase activity in wild-type and HSL-deficient WAT but not in ATGL-deficient WAT, suggesting that ATGL is the sole target for CGI-58-mediated activation of adipose lipolysis. Together, ATGL and HSL are responsible for more than 95% of the TG hydrolase activity present in murine WAT. Additional known or unknown lipases appear to play only a quantitatively minor role in fat cell lipolysis.

Structure-activity relationship for aryl and heteroaryl boronic acid inhibitors of hormone-sensitive lipase.

A range of aryl and heteroaryl boronic acids were tested for their in vitro hormone-sensitive lipase inhibitory properties. (2-Benzyloxy-5-fluorophenyl)boronic acid, (2-benzyloxy-5-chlorophenyl)boronic acid and 5-bromothiophene-2-boronic acid were found to be the most potent HSL inhibitors with IC(50) values of 140, 17 and 350 nM, respectively.

Mortality and suicide among Danish women with cosmetic breast implants.

BACKGROUND: Epidemiologic studies indicate that women with cosmetic breast implants have a significantly increased risk of suicide. Our objectives were to examine mortality among Danish women who underwent cosmetic breast implant surgery and to evaluate the baseline prevalence of psychopathological disorders as measured by admission to a psychiatric hospital among women seeking cosmetic surgery. METHODS: Cohort study of 2761 women who underwent cosmetic breast implant surgery at private clinics of plastic surgery or public hospitals, 7071 women who underwent breast reduction surgery at public hospitals, and 1736 women who attended private clinics for cosmetic surgery other than breast implantation, between 1973 and 1995. Causes of death through 1999 were identified through the Danish Mortality Files. Information on admission to psychiatric hospitals prior to cosmetic surgery was obtained from the Danish Psychiatric Central Register. RESULTS: Women with cosmetic breast implants had significantly elevated standardized mortality ratios (SMRs) for death overall (SMR, 1.4; 95% confidence interval [CI], 1.1-1.7), nonmalignant lung disease (3.4; 95% CI, 1.4-6.9), and suicide (SMR, 3.1; 95% CI, 1.7-5.2). Women who underwent breast reduction exhibited low SMRs for death overall (0.7; 95% CI, 0.7-0.8) and several specific causes, including breast cancer (0.4; 95% CI, 0.2-0.6), whereas death from suicide was moderately above expectation (SMR, 1.6; 95% CI, 1.0-2.5). The prevalence of psychiatric admission prior to cosmetic surgery was higher among women who underwent cosmetic breast implant surgery (8.0%; 95% CI, 7.0%-9.0%) than among women who underwent breast reduction (4.7%; 95% CI, 4.2%-5.2%) or other cosmetic procedures (5.5%; 95% CI, 4.5%-6.7%). When compared with all control groups, women with cosmetic implants had an odds ratio for prior psychiatric admission of 1.7 (95% CI, 1.4-2.0). CONCLUSIONS: Danish women with cosmetic breast implants experienced higher overall mortality compared with women in the general population owing in part to a 3-fold increase in suicide. Women with breast reduction had a low total and cause-specific mortality but a moderate excess risk of suicide. For the first time, to our knowledge, we found evidence of an increased prevalence of mental illness as measured by admission to a psychiatric hospital prior to implant surgery among women receiving cosmetic breast implants. Studies are needed to clarify the underlying reasons for the consistently reported 2- to 3-fold excess of suicide among women with cosmetic breast implants.

Carbazates as potent inhibitors of hormone-sensitive lipase.

The central role of adipose tissue hormone-sensitive lipase in regulating fatty acid metabolism makes it a potential pharmacological target for the prevention of peripheral insulin resistance in obese, prediabetic and diabetic individuals. The synthesis of a new series of carbazates is presented. Modification of the phenolic 4-position in a series of 1,2,3,4-tetrahydroisoquinoline and morpholine derived carbazates, yielded inhibitors of the catalytic activity of this enzyme with nanomolar potency.

Synthesis and structure-activity relationship for a novel class of potent and selective carbamoyl-triazole based inhibitors of hormone sensitive lipase.

The central role of the intracellular enzyme hormone-sensitive lipase (HSL) in regulating fatty acid metabolism makes it an interesting pharmacological target for the treatment of insulin resistant and dyslipidemic disorders where a decrease in delivery of fatty acids to the circulation is desirable, e.g., in individuals with type 2 diabetes, metabolic syndrome, or impaired glucose tolerance. On the basis of a lead structure from high throughput screening, we have identified a very potent type of carbamoyl-triazole inhibitors of HSL. As part of the lead optimization program, four new classes of carbamoyl-triazoles were synthesized and tested with respect to potency, efficacy and selectivity. Methyl-phenyl-carbamoyl-triazoles were identified as potent and efficacious HSL inhibitors. These compounds do not inhibit other hydrolases such as hepatic lipase, lipoprotein lipase, pancreatic lipase, and butyrylcholine esterase. However, the inhibitors 4b and 4g with IC(50) values for HSL of 0.17 and 0.25 microM, respectively, were the only inhibitors selective against acetylcholine esterase. A reversible pseudosubstrate inhibition mechanism is proposed for this class of inhibitors.

Self-reported musculoskeletal symptoms among Danish women with cosmetic breast implants.

BACKGROUND: No epidemiological evidence of an association between silicone breast implants and connective tissue disease has been found. Based on case reports, it has been hypothesized that silicone breast implants may be associated with a unique rheumatic symptom cluster termed "atypical connective tissue disease." MATERIAL AND METHODS: We have evaluated self-reported rheumatic symptoms among women who received breast implants between 1977 and 1997 at 2 private plastic surgery clinics in Denmark. Women with other cosmetic surgery, including breast reduction, as well as women from the general population, were identified as controls. RESULTS: No statistically significant differences in mild (odds ratio [OR] = 0.9; 95% confidence interval [CI] = 0.6-1.3), moderate (OR = 0.7; 95% CI = 0.4-1.2), or severe (OR = 1.1; 95% CI = 0.6-2.1) musculoskeletal symptoms were observed when women with breast implants were compared with women with other cosmetic surgery. Compared with women from the general population, women with breast implants were statistically significantly less likely to have mild or moderate musculoskeletal symptoms (OR = 0.5; 95% CI = 0.3-0.7 and OR = 0.3; 95% CI = 0.2-0.5, respectively); for severe symptoms the deficit was not statistically significant (OR = 0.7; 95% CI = 0.3-1.3). For individual symptom groups, there was no consistent pattern of reporting among women with implants. CONCLUSION: We did not find an excess of rheumatic symptoms or symptom clusters among women with breast implants. In fact, the occurrence of mild, moderate, and severe musculoskeletal symptoms was generally lower among women with implants compared with women with other cosmetic surgery and women in the general population.

Characteristics of women with cosmetic breast implants compared with women with other types of cosmetic surgery and population-based controls in Denmark.

Herein the authors describe characteristics of women with breast implants compared with women with other types of cosmetic surgery as well as population controls. All women who acquired breast implants from 1977 to 1997 were identified from the files of two private plastic surgery clinics in Denmark. Patient characteristics were obtained through a self-administered questionnaire. The magnitude of differences between patient and control groups was estimated using odds ratios and 95% confidence intervals. Women with breast implants had a significantly lower body mass index and reported a two-fold greater incidence of current smoking compared with women from the general population and compared with women with other cosmetic surgery. Women with implants reported a greater number of full-term pregnancies and were less likely than controls to have had their first birth at age 30 years or older. Women with implants were not more likely than women in either control group to report a history of diseases, including connective tissue diseases, cancer, or depression before their implant surgery. Women with cosmetic breast implants differ from women with other forms of cosmetic surgery and from general population controls with respect to characteristics that may importantly influence health outcomes and that need to be addressed in future breast implant studies.

Epidemiological investigation of local complications after cosmetic breast implant surgery in Denmark.

Concern has been raised recently regarding the absence of information on the occurrence and severity of local complications after cosmetic breast implantation. The authors evaluated the occurrence of local complications in a large epidemiological retrospective cohort study of women with cosmetic breast implants in Denmark. All women with breast implants were identified from the files of two private clinics of plastic surgery in Denmark. Information on implant characteristics, surgical procedure, as well as short- and long-term complications was obtained through medical record review. Patient characteristics were obtained through a self-administered questionnaire. A total of 754 women (1,572 implants) had at least one cosmetic implantation performed at the study clinics. Average age at implantation was 32 years. Implant types included silicone double lumen with textured surface, 31.2%; silicone single lumen with textured surface, 27.8%; silicone single lumen with smooth surface, 24.5%; silicone double lumen with smooth surface, 0.8%; and other or missing information, 15.7%. Average implant size was 247 ml (range, 110-630 ml). Placement was submuscular for 91.3% of implants, subglandular for 2.6%, and 6.1% had no available information. Overall, 77.8% of implantations were not followed by complications, 17.8% were followed by one complication, 3.6% were followed by two complications, and 0.8% were followed by three or more complications. In 94.6% of implantations, no additional hospitalizations were recorded as a result of complications. Forty-seven of 57 explantations/reimplantations were secondary to postoperative complications. General complications such as hematoma and infection were rare, occurring in 2.3% and 2.0% of implantations respectively. Capsular contracture remains the most common complication, occurring in 11.4% of implantations. In this investigation, among the first epidemiological studies of local complications, the authors found cosmetic breast implant surgery to be associated with a low frequency of normal surgical complications such as infection, hematoma, and wound dehiscence. Most complications were mild and did not lead to additional hospitalization. The complication that led most frequently to the need for additional surgery/hospitalization was capsular contracture. Kjøller K, Hölmich LR, Jacobsen PH, Friis S, Fryzek J, McLaughlin JK, Lipworth L, Henriksen TF, Jørgensen S, Bittmann S, Olsen JH. Epidemiological investigation of local complications after cosmetic breast implant surgery in Denmark.

Synthesis and biological evaluation of novel thio-substituted chromanes as high-affinity partial agonists for the estrogen receptor.

Synthesis of (+/-)-cis-7-hydroxy-3-phenyl-4-(4-(2-piperidinoethanethio)phenyl)chromane (13) and (+/-)-cis-7-hydroxy-3-phenyl-4-(4-(2-pyrrolidinoethanethio)phenyl)chromane (15) is presented. These compounds are representatives of a novel class of compounds with high in vitro binding affinity for the estrogen receptor (IC(50)=7-10 nM), and very low in vitro uterotrophic activity (max stim.=5-17% rel to moxestrol; EC(50)=0.5-1.8 nM).

Synthesis and pharmacological evaluation of novel cis-3,4-diaryl-hydroxychromanes as high affinity partial agonists for the estrogen receptor.

The syntheses and in vitro pharmacological evaluation of a number of cis-3,4-diaryl-hydroxy-chromanes are reported, along with the results of a thorough in vivo profiling of the tissue-selective estrogen partial-agonist NNC 45-0781 [3, (-)-(3S,4R)-7-hydroxy-3-phenyl-4-(4-(2-pyrrolidinoethoxy)phenyl)chromane]. These studies showed that NNC 45-0781 is a very promising candidate for the prevention of post-menopausal osteoporosis, and the treatment of other health issues related to the loss of endogenous estrogen production.