Joint Effects of the Epigenetic Alteration of Neurotrophins and Cytokine Signaling: A Possible Exploratory Model of Affective Symptoms in Alcohol-Dependent Patients?

AIMS: Neurotrophins have been linked to the symptomatology of alcohol dependence. We aimed to investigate a possible association between the methylation of the promoters of both neurotrophins, the serum levels of the cytokines and core symptoms of alcohol dependence as withdrawal severity and anxiety. METHODS: In this study we investigated a possible association between alterations in the methylation of the BDNF IV/NGF I gene promoter and the cytokines tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) in 55 male alcohol-dependent patients. RESULTS: Mean methylation of the promoter of the BDNF gene was significantly associated with the TNF-α serum levels and the CIWA-score during withdrawal (P < 0.001). Moreover, mean methylation of the NGF I promoter was significantly associated with the IL-6 serum levels and STAI-I score during withdrawal (P < 0.001). CONCLUSION: Our results suggest an association between the epigenetic regulation of both neurotrophins, BDNF and NGF, cytokine release and the symptomatology of alcohol dependence. They imply that changes in the methylation of neurotrophins may contribute to the symptomatology of alcohol dependence by affecting relevant downstream signaling cascades.

BDNF serum levels and promoter methylation of BDNF exon I, IV and VI in depressed patients receiving electroconvulsive therapy.

We examined potential changes in brain-derived neurotrophic factor (BDNF) serum levels and promoter methylation of the BDNF gene in 11 patients with treatment-resistant major depressive disorder during a series of electroconvulsive therapy (ECT). Blood samples were taken before, 1 and 24 h after ECT treatment sessions 1, 4, 7 and 10. Patients remitting under ECT had significantly lower mean promoter methylation rates, especially concerning the exon I promoter, compared to non-remitters (both p < 0.002). These findings may point to a depression subtype in which ECT is particularly beneficial.

Alcohol-induced changes in methylation status of individual CpG sites, and serum levels of vasopressin and atrial natriuretic peptide in alcohol-dependent patients during detoxification treatment.

Disturbances of volume-regulating peptides like vasopressin (AVP) and atrial natriuretic peptide (ANP) have been described in early abstinent alcohol-dependent patients. In a longitudinal approach, we investigated whether changes in AVP and ANP serum levels correlated to cytosine-phosphatidyl-guanine (CpG) methylation of the respective gene promoters on days 1, 7 and 14 of alcohol withdrawal. We analyzed the blood samples of 99 patients suffering from alcohol dependence alongside age- and BMI-matched controls. Concerning AVP promoter methylation, we observed an interaction between time of measurement and CpG loci with CpG 2 showing a significant increase in methylation from day 1 to 14. Serum levels of AVP were significantly decreased in the patient group. Compared to healthy controls, promoter-related DNA methylation of the ANP promoter was significantly reduced on days 7 and 14. Moreover, we detected a significant interaction between CpG position and group. In both cases the difference was mainly observed at CpG 1. The present study shows significant changes in the methylation status of individual CpG sites of AVP and ANP. Observing respective alterations of AVP serum protein levels in alcohol-dependent patients during detoxification treatment, we consider methylation as a possible mode of regulation for these proteins during alcohol detoxification.

Atrial natriuretic peptide, arginine vasopressin peptide and cortisol serum levels in opiate-dependent patients.

Preclinical studies suggest that chronic drug abuse profoundly alters stress-responsive systems. The best studied of the stress-responsive systems in humans is the hypothalamic-pituitary-adrenal (HPA) axis. Apart from cortisol, arginine vasopressin peptide (AVP), and atrial natriuretic peptide (ANP) are known to directly impact upon the HPA axis in addictive behavior. We investigated alterations in ANP, AVP and cortisol serum levels in opiate-dependent patients who received diacetylmorphine treatment within a structured opiate maintenance program. ANP serum levels were significantly increased in opiate-dependent patients as compared to healthy controls, whereas AVP and cortisol serum levels were reduced. The ANP, AVP and cortisol serum levels were not significantly associated with the psychometric dimensions of heroin craving. In conclusion, chronic drug abuse profoundly alters stress-responsive systems like the HPA axis. Alterations of AVP, ANP and cortisol appear to constitute an important component in the neurobiology of opiate-dependent patients.

Epigenetic down regulation of nerve growth factor during alcohol withdrawal.

We investigated the Cytosin-phosphatidyl-Guanin (CpG) island promoter methylation (mean and methylation of individual CpG-sites) of the nerve growth factor (NGF) gene in the blood of alcohol-dependent patients (57 male patients) during withdrawal (days 1, 7 and 14). Methylation and NGF serum levels did not change significantly from days 1-7. From days 7-14, mean methylation increased (F = 30.55, P < 0.001), whereas the NGF serum levels decreased significantly (days 7-14: F = 17.95, P < 0.001). The NGF serum levels were significantly associated with the mean methylation of the investigated CpG-sites (F = 1.55, P < 0.001). These results imply an epigenetic regulation of the NGF gene during alcohol withdrawal.

Association of nerve growth factor and vascular endothelial growth factor A with psychometric measurements of opiate dependence: results of a pilot study in patients participating in a structured diamorphine maintenance program.

Preclinical study results suggest that neurotrophic peptides like nerve growth factor (NGF) and vascular endothelial growth factor A (VEGF-A) may be associated with symptoms of addictive behavior like withdrawal symptoms and rewarding effects. We investigated alterations in NGF and VEGF-A serum levels in opiate-dependent patients (25 male patients), who received diamorphine (DAM, heroin) treatment within a structured opiate maintenance program, and compared the results with the NGF and VEGF-A serum levels of healthy controls (23 male controls). NGF and VEGF-A serum levels were assessed before and after DAM administration twice a day (in the morning (16 h after last application--t1) and in the afternoon (7 h after last application--t3)) in order to detect a possible immediate or summative (in the afternoon) heroin effect on these two neuropeptides. Moreover, we investigated possible associations between the serum levels of these neurotrophic growth factors and psychometric dimensions of addictive behavior, e.g. craving, withdrawal, depression. Whereas there was no direct effect of DAM application on the serum levels of both neurotrophic growth factors neither in the morning nor in the afternoon, the NGF serum levels of the patient group were found to be significantly increased at all four time points of investigation compared with the healthy controls. In contrast, VEGF-A serum levels did not differ significantly in the patient and control groups. We found a significant positive association between the NGF serum levels and several items of the short opiate withdrawal scale as well as a negative association between self-reported mood (measured by visual analogue scale) and mood before heroin application (in the morning as in the afternoon). Moreover, we found a significant positive association between the NGF serum levels (t1 and t3) and the self-reported craving for methadone. In contrast, we found a negative association between the VEGF-A serum levels and avoidance, anxiety, suicide intentions of the SCL-90 as well as a positive association between the VEGF-A serum levels and the subscales of the heroin craving questionnaire measuring the rewarding effects of heroin. In conclusion, the results of this pilot study show that there might be an association between symptoms of opiate dependence and withdrawal and serum levels of VEGF-A and NGF.

Prolactin serum levels during alcohol withdrawal are associated with the severity of alcohol dependence and withdrawal symptoms.

BACKGROUND: Prolactin serum levels have been described to be elevated during alcohol withdrawal in alcohol-dependent patients and normalize during abstinence. Alterations in prolactin levels may reflect disturbances of dopaminergic neurotransmission which is of crucial importance for alcohol-seeking behavior. METHODS: In this longitudinal observational study, we investigated prolactin serum levels in 99 male patients during the first 14 days of alcohol withdrawal and early abstinence and in 43 healthy controls. To assess the severity of alcohol dependence, the extent of withdrawal symptoms, craving, depressive symptoms, and anxiety, we employed a structured interview including psychologic measurements. RESULTS: Prolactin serum levels were elevated during the whole study period in alcohol-dependent patients compared to the healthy control group. Prolactin levels at admission (first day of alcohol withdrawal) were associated with the severity of alcohol withdrawal (CIWA-Ar) and of alcohol dependence (SESA) but not with the other assessed psychologic parameters. CONCLUSIONS: The presented findings confirm that prolactin is significantly elevated in alcohol-dependent patients during alcohol withdrawal and early abstinence, not showing a rapid decline after cessation of drinking. The association with the severity of withdrawal and dependence may reflect at least partially the individual alterations in the dopaminergic and glutamatergic pathways.

The physiological role of hormones in saliva.

The assessment of hormones in saliva has gained wide acceptance in clinical endocrinology. To date, there is no hypothesis as to why some hormones can be found in saliva, while others cannot, and whether there is a physiological consequence of this fact. A number of carefully performed studies give examples of important physiological hormonal activity in saliva. Steroids, such as androgens, act as pheromones in olfactory communication of various mammalian species, such as facilitating mating behavior in swine or serving as odor cues for rodent nestlings. Salivary peptide hormones, such as epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha), and amines such as melatonin, are involved in the regulation of inflammatory processes and in the promotion of cell proliferation, and contribute to a rapid wound healing in the oropharyngeal epithelia. Current data provide evidence of the involvement of salivary cytokines, such as interleukin-8 and leptin, in tumorgenesis in the oral cavity and the salivary glands. The tumor tissues express and release significantly more of these cytokines than healthy glands. Consequently, the assessment of salivary hormone profiles may provide promising targets for diagnostic tumor markers.

Influence of gestational age, cesarean section, and type of feeding on fecal human beta-defensin 2 and tumor necrosis factor-alpha.

OBJECTIVE: : Development of the mucosal immune system is essential for controlling antigenic response. External factors are known to influence the immune system, such as breast-feeding or the mode of delivery. The aim of the present study was to investigate maturation of the enteric immune system. PATIENTS AND METHODS: : In stool samples of 59 preterm and term-born infants we measured the concentration of human beta-defensin 2 (HBD 2), an endogenous antimicrobial peptide, and tumor necrosis factor-alpha (TNF-alpha), a cytokine playing a central role in mucosal inflammation, by enzyme-linked immunosorbent assay. RESULTS: : Mode of delivery as well as nutrition (breast-feeding or formula) had no influence on the fecal concentration of HBD-2 or TNF-alpha, but there was a significant increase in the concentration of HBD-2 in correlation with gestational age. TNF-alpha showed no change in concentration. CONCLUSIONS: : Low fecal HBD-2 may be a risk factor in preterm infants to develop neonatal enteric disease, such as necrotizing enterocolitis.

Serum levels of vascular endothelial growth factor A increase during alcohol withdrawal.

Vascular endothelial growth factor A (VEGF-A) is a key regulator of angiogenesis. This study investigated VEGF-A serum levels during alcohol withdrawal (days 1, 7 and 14, 76 male patients, 38 healthy controls). Patients showed significantly higher VEGF-A serum levels (t = 2.620, P = 0.010), which increased significantly during withdrawal (F = 4.484, P = 0.014, mean difference = -36.835, P = 0.037). The increase of VEGF-A serum levels was significantly associated with initial breath alcohol concentration and the sumscore of the severity scale of alcohol dependence (SESA questionnaire, F = 5.252, P = 0.008). Increase of VEGF-A serum levels is closely associated to alcohol intoxication and severity of alcohol dependence.

Salivary leptin as a candidate diagnostic marker in salivary gland tumors.

BACKGROUND: Since the discovery of autonomous leptin production in salivary glands, very few studies have reported on the physiological or pathological meaning of this particular cytokine in saliva. The aim of this study was to investigate the expression of leptin and its receptors Ob-Ra and Ob-Rb in parotid salivary gland tumors, with particular regard to a potential use of leptin as a tumor marker. METHODS: Parotid tissue samples from healthy individuals (n = 31) and tumor patients (n = 97, including tissue samples from pleomorphic adenomas, adenolymphomas, basal cell adenomas, and diverse carcinomas) were analyzed by use of ApoTome-technique microscopy, immunohistochemistry, immunofluorescence, immunoblotting, and quantitative real-time PCR. Salivary and plasma leptin concentrations were measured by using ELISA. Ultrasound was used to determine tumor size before surgery. RESULTS: In all salivary gland tumors leptin was expressed in much higher amounts than in healthy parotid tissues. The cytokine was not imported from the blood but actively produced by the tumors. Immunoblotting results indicated that leptin was present as oligomers in salivary glands. Furthermore, the examined tumors overexpressed the receptor isoforms Ob-Ra and Ob-Rb. Measured leptin concentrations in mixed saliva samples were significantly increased in patients with parotid tumors [mean (SD) 673 (484) pg/mL in pleomorphic adenomas, 679 (465) pg/mL in adenolymphomas, and 880 (618) pg/mL in carcinomas] vs controls [125 (36) pg/mL] (P < 0.001). CONCLUSIONS: This is the first study to show that the analysis of salivary leptin in mixed saliva samples may allow preoperative differentiation between tumor patients and healthy individuals.

Significance of salivary adrenomedullin in the maintenance of oral health: stimulation of oral cell proliferation and antibacterial properties.

Adrenomedullin (ADM) promotes epithelial cell proliferation and antimicrobial activity in the gastrointestinal tract. Since ADM is also present in saliva, it was the objective of our study to investigate the role of salivary ADM in the maintenance of oral health. We found mRNA for ADM and the specific receptors CRLR-RAMP2 and CRLR-RAMP3 expressed by the salivary glands and by oral keratinocytes. The hormone was detected in the glandular tissues by western blot, being slightly bigger than the synthetic peptide, indicating a posttranslational modification. ADM was localized using immunohistochemistry and immunofluorescence. Staining specific for ADM was observed near the cell nuclei of the salivary ducts and acini. There was no correlation between ADM from matched saliva and serum of healthy volunteers. The physiological role of salivary ADM in the oral cavity was investigated by incubating buccal keratinocytes with ADM and measurement of the cell proliferation using bromodeoxyuridine (BrDU) assays. There was a significant, dose dependent increase (up to 5-fold; p<0.001) of the BrDU incorporation after stimulation with ADM (1.5 to 50 ng/mL). The antibacterial properties of salivary ADM was studied by incubation of Gram+ and Gram- bacteria and yeast, isolated from human oral flora, with ADM (0.01-1000 ng/mL) for 24 h. Bacterial growth was inhibited dose dependently (p<0.001), whereas the yeast was not affected. This finding was consistent when using radial growth inhibition test on agarose plates as well as photometric measurement in microtiter plates. Our findings suggest an important role of salivary ADM in the maintenance of oral health, being involved as well as in oral cell proliferation and anti-bacterial defense.

Short Communication: Interaction of Nerve Growth Factor (NGF) and Vascular Endothelial Growth Factor (VEGF) in Healthy Individuals.

NGF and VEGF are known to be involved in different psychiatric diseases. In order to verify hints from basic research that both neurotrophines interact with each other, serum levels of NGF and VEGF were measured in a cohort of 33 healthy individuals and correlated. NGF level was 126.30 pg/mL (±155.43), and VEGF level was 57.28 pg/mL (±44.48). Both factors were significantly correlated, confirming their interaction and legitimising the usage of their respective ratio (0.8 (±0.42)) as a less varying additional marker in prospective studies.

Current status of salivary hormone analysis.

BACKGROUND: Saliva, which offers a noninvasive and stress-free alternative to plasma and serum, is a widely accepted sample source for analysis of steroids and also of certain amines and peptides. In recent years, numerous publications have described the use of salivary hormone analysis in many fields of clinical and basic research. CONTENT: This review provides an overview of the current applications of salivary hormone analysis. A description of the different modes of hormone entry into saliva is followed by a detailed description of analytical methods and approaches for reliable collection of saliva, including several interesting applications in diverse fields including psychiatry, stress research, clinical endocrinology, sports medicine, and veterinary medicine. SUMMARY: Although saliva has not yet become a mainstream sample source for hormone analysis, it has proven to be reliable and, in some cases, even superior to other body fluids. Nevertheless much effort will be required for this approach to receive acceptance over the long term, especially by clinicians. Such effort includes the development of specific and standardized analytical tools, the establishment of defined reference intervals, and implementation of round-robin trials. One major problem, the lack of compliance sometimes seen in outpatient saliva donors, requires strict standardization of both collection and analysis methods to achieve better comparability and assessment of published salivary hormone data.

NGF plasma levels increase due to alcohol intoxication and decrease during withdrawal.

Recent studies show that alcohol dependence is associated with alterations in plasma levels of nerve growth factor (NGF). The aim of this study was to further elucidate reported alterations in NGF plasma levels during alcohol intoxication and withdrawal. Therefore, we assessed NGF plasma levels by enzyme-linked immunosorbent assay (ELISA) on admission (day 0) and day 7 of alcohol withdrawal in male alcohol dependent patients (n=75) in comparison to healthy controls (n=44). We found significant higher (U=1005.0, p<0.001) NGF plasma levels in the alcohol-dependent patients. Subgroup analysis showed significant higher (U=-2.934, p=0.003) NGF plasma levels in patients suffering from acute alcohol intoxication (group A) than in early abstinent patients (group B). From day 0 to day 7 of alcohol withdrawal NGF plasma levels decreased significantly in both groups (group A: Z=-3.118, p=0.002, group B: Z=-2.103, p=0.035). Our results suggest that acute alcohol intoxication is associated with an increase in NGF plasma levels, which decrease during alcohol withdrawal. These results suggest that NGF plasma levels increase as part of a regulation mechanism that counteracts alcohol intoxication.

Evaluation of saliva collection devices for the analysis of steroids, peptides and therapeutic drugs.

The recovery of steroids, peptides and therapeutic drugs from commercial saliva collection devices was investigated. Saliva, spiked with defined concentrations of the analytes was applied to the Quantisal, three different Salivettes, and the Saliva-Collection-System to investigate effects of volume, exposure time and temperature on the recovery. Additionally, saliva was collected from healthy subjects with the same devices. It was found that glucocorticoids can be measured very well from samples obtained with the synthetic fiber Salivettes and the Quantisal (80-100%). For androgens, the Quantisal and the Saliva-Collection-System reached recoveries >80%. The Quantisal and polyester Salivette achieved best recoveries (>80%) for peptides. The results for the cotton Salivette were extremely poor for melatonin, insulin or IL-8 (<20%). The results from the spike-recovery experiments were confirmed by samples collected from healthy volunteers. For most therapeutic drugs the synthetic fiber Salivettes achieved best recoveries of 100+/-10%. Longer exposure of saliva on the collection devices must be avoided for most of the analytes, due to their limited stability and increased adsorption. In conclusion, no device is suitable for all of the salivary compounds. Strict pre-analytical precautions must be considered (e.g. immediate processing of the sample) to guarantee reliable analytical results.

Helicobacter pylori and intestinal parasites are not detrimental to the nutritional status of Amerindians.

Gastrointestinal parasites have evolved with humans and colonize many asymptomatic subjects. We investigated the influence of microbial gastrointestinal colonization on the nutritional status of rural Amerindians (40 males and 61 females). Helicobacter pylori was detected by 13C-breath test, and intestinal parasites were detected in fecal specimens. Body morphometry and bioelectrical impedance measurements were measured. Although Amerindians showed low height and weight for age, they had an adequate body mass index, morphometric parameters, and cell mass. Intestinal parasites were detected in 99% of the subjects, with no detrimental effect on nutritional parameters. Helicobacter pylori was present in 82% of adults and half the children, and was positively correlated with improved nutritional status. Despite the high prevalence of gastrointestinal microbes often associated with disease, the studied population of Amerindians had a body morphometry and composition indicative of good nutritional status, and improved in children positive for gastric H. pylori.

Saliva: a reliable sample matrix in bioanalytics.

Saliva is gaining increasing attention as a bioanalytical sample matrix. Mostly because of the easy and noninvasive collection, it is not only beneficial in endocrinological and behavioral science, but also in pediatrics. Saliva also has the advantage of being the only body fluid which can be collected even during physical exercise, for example, during sportive activities, and there are physiological characteristics that make it superior to serum/plasma or urine for specific scientific questions. This review provides an insight into the physiology of saliva formation, explaining how certain compounds enter this bodily fluid, and gives advice for collection, storage and analytical methods. Finally, it presents a number of reliable and proven applications for saliva analysis from scientific fields including endocrinology, sports medicine, forensics and immunology.

Quantification of busulfan in saliva and plasma in haematopoietic stem cell transplantation in children : validation of liquid chromatography tandem mass spectrometry method.

BACKGROUND AND OBJECTIVE: Busulfan pharmacokinetic studies suggest that an individual dosing strategy may be necessary to optimise systemic exposure in order to decrease toxicity and improve outcome in haematopoietic stem cell transplantation. Therapeutic and toxic effects of the busulfan/cyclophosphamide regimen have been related to the area under the busulfan plasma concentration-time curve. Because of practical limitations in obtaining blood from children, saliva was evaluated as an alternative matrix for therapeutic drug monitoring, offering the advantages of a non-invasive, rapid and easy sampling procedure. Another objective was to evaluate an easy and robust liquid chromatography- tandem mass spectrometry method for plasma and saliva busulfan determination. METHODS: An online extraction cartridge with column-switching technique, analytical liquid chromatography over a Chromolith RP 18 e column, and tandem mass spectrometry were used to quantify busulfan concentrations in matched plasma and saliva samples. The study population consisted of ten patients, aged 1.3-19 years (median age 11.8 years, seven females, three males), undergoing haematopoietic stem cell transplantation. All patients received busulfan 0.8-1.3 mg/kg orally every 6 hours for a total of 16 doses, followed by two doses of cyclophosphamide (60 mg/kg/day). RESULTS: The lowest limit of detection was 2 microg/L and the lower limit of quantification was 10 microg/L. Only 100 microL of plasma/saliva was needed. The mean recoveries (SD) of busulfan were 97.2% (2.7) in plasma and 100.4% (1.3) in saliva. Intra- and inter-assay imprecision was 2-3% and 2-4% for plasma, and 1-2% and 2-4% for saliva (concentration range 30-1,500 microg/L). The bias was <4% for both plasma and saliva. The correlation between the busulfan concentration in plasma and saliva was highly significant (r=0.958; p<0.0001; saliva/plasma ratio=1.09+/-0.04; n=69 sample pairs). The apparent plasma clearance was slightly higher than the apparent saliva clearance (202+/-31 mL/h/kg vs 189+/-28 mL/h/kg; p=0.001). The mean elimination half-life was found to be 2.31+/-0.46 hours for plasma and 2.30+/-0.36 hours for saliva; these were not significantly different (p=0.83). CONCLUSION: The present study demonstrated that busulfan analysis in saliva could be a valuable and reliable alternative to plasma analysis.

Influence of commercial collection devices for saliva on the reliability of salivary steroids analysis.

Saliva analysis is an accepted non-invasive alternative to plasma in pediatric endocrinology. Although commercial saliva collectors are available, the reliability of these devices for the analysis of salivary hormones has not been proved. We investigated the recovery and linearity of salivary steroids (cortisol, cortisone, 17-hyroxyprogesterone, testosterone, androstenedione) being relevant in endocrine research and therapy control. Pooled saliva was spiked with ascending concentrations of the steroids and applied onto a variety of absorbents, such as the cotton and the polyester (PE) Salivette (Sarstedt), the foam-tip applicator (Whatman) and strips of blood-spot collection paper (Whatman). Analysis was performed by LC-MS/MS. Best results were achieved using the PE Salivette, yielding recoveries (%) of 99.8 (cortisol), 98.7 (cortisone), 91.8 (17OHP), 96.3 (testosterone), 98.9 (androstendione) with a volume recovery of 98+/-1%. Using the blood-spot paper, recoveries (%) were 92.0 (cortisol), 89.1 (cortisone), 72.0 (17OHP), 70.3 (testosterone) and 77.1 (androstendione). The recovery of glucocorticoids was significantly higher compared to androgens (p<0.001). The recovery of liquid volume was 95+/-2%. The cotton Salivette yielded weak recoveries of 88.7 (cortisol), 86.2 (cortisone), 60.9 (17OHP), 62.0 (testosterone) and 72.4 (androstendione). The recovery of the glucocorticoids differed significantly from the androgens (p<0.001). Liquid recovery was most variable with 89+/-8%. The weakest recoveries were found in the foam-tips being 76.2 for cortisol, only 41.8 for cortisone, 31.1 for 17OHP, 38.5 for testosterone and 36.1 for androstendione. The volume recovery here was 97+/-1%. We assume only the PE version of the Salivette suitable for salivary steroid analysis. The weak recovery from the cotton version is a severe problem due to lacking comparability with values obtained with the polyester wads and the weak homogeneity as observed over a physiological concentration range.