Assessment of global histone acetylation in pediatric and adolescent obesity: Correlations with SIRT1 expression and metabolic-inflammatory profiles

BACKGROUND

Epigenetic modifications, particularly histone acetylation-deacetylation and its related enzymes, such as sirtuin 1 (SIRT1) deacetylase, may have substantial roles in the pathogenesis of obesity and its associated health issues. This study aimed to evaluate global histone acetylation status and SIRT1 gene expression in children and adolescents with obesity and their association with metabolic and anthropometric parameters.

METHODS

This study included 60 children and adolescents, 30 with obesity and 30 normal-weight. The evaluation consisted of the analysis of global histone acetylation levels and the expression of the SIRT1 gene in peripheral blood mononuclear cells, by specific antibody and real-time PCR, respectively. Additionally, insulin, fasting plasma glucose, lipid profile and tumor necrosis factor α (TNF-α) levels were measured. Insulin resistance was assessed using the homeostasis model assessment of insulin resistance (HOMA-IR). Metabolic syndrome was determined based on the diagnostic criteria established by IDF.

RESULTS

Individuals with obesity, particularly those with insulin resistance, had significantly higher histone acetylation levels compared to control group. Histone acetylation was positively correlated with obesity indices, TNF-α, insulin, and HOMA-IR. Additionally, a significant decrease in SIRT1 gene expression was found among obese individuals, which was negatively correlated with the histone acetylation level. Furthermore, SIRT1 expression levels showed a negative correlation with various anthropometric and metabolic parameters.

CONCLUSION

Histone acetylation was enhanced in children and adolescents with obesity, potentially resulting from down-regulation of SIRT1, and could play a role in the obesity-associated metabolic abnormalities and insulin resistance. Targeting global histone acetylation modulation might be considered as an epigenetic approach for early obesity management.

Evaluation of Mn-superoxide dismutase and catalase gene expression in childhood obesity: its association with insulin resistance

Background Obesity is associated with oxidative stress. Superoxide dismutase (SOD) is the first line of defense against reactive oxygen species (ROS), eliminating the strong superoxide radical and producing H2O2, which can then be degraded by catalase (CAT). The main objective of this study was to evaluate the gene expression antioxidant enzymes (Mn-SOD and CAT) in peripheral blood mononuclear cells (PBMCs) of obese and normal-weight children, and its association with anthropometric and biochemical parameters. Methods Thirty obese and 30 control subjects between the ages of 8 and 16 years were enrolled in this study. Serum insulin levels were measured using enzyme-linked immunosorbent assay (ELISA), and insulin resistance was calculated using the homeostasis model assessment of insulin resistance (HOMA-IR). Biochemical parameters were also measured. PBMCs of the subjects were separated and Mn-SOD and CAT gene expression was measured using real-time polymerase chain reaction (PCR). Results Mn-SOD and CAT gene expression was significantly lower in the obese group compared with the control group (p<0.01). Also, a positive correlation was observed between the gene expression of Mn-SOD and CAT and body mass index (BMI), fasting blood sugar, insulin resistance, low density lipoprotein-cholesterol (LDL-C) cholesterol, triglycerides (TG) and systolic blood pressure (SBP). Conclusions Induction of antioxidants, especially Mn-SOD and CAT, can lead to reduction of oxidative stress and prevent the complications of obesity in children.

Evaluation of Plasma TRB3 and Sestrin 2 Levels in Obese and Normal-Weight Children

OBJECTIVE

Obesity in childhood and adolescence is associated with metabolic syndrome and cardiovascular diseases. TRB3 (Tribbles homolog 3) and sestrin 2 are two newly found proteins that have been identified to play an important role in obesity and its complications.

AIM

The purpose of this study was to evaluate concentrations of TRB3 and sestrin 2 in plasma of obese and normal-weight children and adolescents, and their association with metabolic and anthropometric parameters.

METHODS

Plasma levels of TRB3, sestrin 2, insulin, fasting plasma glucose (FPG), and lipid profile were evaluated in 70 children and adolescents (34 obese and 36 controls). Insulin resistance was calculated using a homeostasis model assessment of insulin resistance. Metabolic syndrome was defined according to IDF criteria.

RESULTS

Plasma TRB3 levels of the obese subjects were significantly higher than that of normal weight subjects. TRB3 levels were positively correlated with BMI, BMI z-score, waist circumference, and FPG. The concentration of sestrin 2 was significantly lower in obese subjects compared to normal-weight subjects. A statistically significant positive correlation was observed between plasma concentrations of sestrin 2 and high-density lipoprotein cholesterol. Neither TRB3 nor sestrin 2 were correlated with insulin resistance and metabolic syndrome.

CONCLUSION

Both TRB3 and sestrin 2 may contribute to the development of obesity and its complications and can be considered interesting therapeutic target for the treatment of obesity.

Staged Bilateral Laparoscopic Adrenalectomy for Infantile ACTH-independent Cushing's Syndrome (Bilateral Micronodular Non-pigmented Adrenal Hyperplasia): A Case Report

ACTH-independent Cushing's syndrome is an uncommon disorder in children. While laparoscopic adrenalectomy is well-established in adults, it is rarely used in infants and is associated with some concerns. A seven-month infant was referred to our hospital due to progressive signs and symptoms of Cushing's syndrome. Laboratory data confirmed ACTH-independent hypercortisolism. No history of exogenous corticosteroid contact was observed. The patient underwent left transperitoneal laparoscopic adrenalectomy when she was 7 months old, nevertheless,complete response was not seen. The patient underwent right laparoscopic adrenalectomy (contra-lateral adrenal gland) when she was 20 months old. The signs and symptoms of Cushing's syndrome began to resolve and serum and urine cortisol levels became normal 3 months after the second surgery. laparoscopic adrenalectomy is safe and feasible in infants, and in this case, relieved patient of the symptoms and saved her life.

Effect of G-Coat Plus on the mechanical properties of glass-ionomer cements

BACKGROUND

Although various mechanical properties of tooth-coloured materials have been described, little data have been published on the effect of ageing and G-Coat Plus on the hardness and strength of the glass-ionomer cements (GICs).

METHODS

Specimens were prepared from one polyacid-modified resin composite (PAMRC; Freedom, SDI), one resin-modified glass-ionomer cement; (RM-GIC; Fuji II LC, GC), and one conventional glass-ionomer cement; (GIC; Fuji IX, GC). GIC and RM-GIC were tested both with and without applying G-Coat Plus (GC). Specimens were conditioned in 37 °C distilled water for either 24 hours, four and eight weeks. Half the specimens were subjected to a shear punch test using a universal testing machine; the remaining half was subjected to Vickers Hardness test.

RESULTS

Data analysis showed that the hardness and shear punch values were material dependent. The hardness and shear punch of the PAMRC was the highest and GIC the lowest. Applying the G-Coat Plus was associated with a significant decrease in the hardness of the materials but increase in the shear punch strength after four and eight weeks.

CONCLUSIONS

The mechanical properties of the restorative materials were affected by applying G-Coat Plus and distilled water immersion over time. The PAMRC was significantly stronger and harder than the RM-GIC or GIC.

Recurrent Hepatitis in Two Iranian Children: A Novel (Q166R) Mutation in EIF2AK3 Leading to Wolcott-Rallison Syndrome

Early-onset diabetes, liver dysfunction, growth retardation, spondyloepiphyseal dysplasia, and tendency to skeletal fractures due to osteopenia are characteristics of Wolcott-Rallison syndrome (WRS). Eukaryotic translation initiation factor 2α kinase (EIF2AK3) is the only known gene, which is responsible for this rare autosomal recessive disorder. Here, we report two siblings a girl and a boy with diabetes mellitus (DM) who presented in one and two months of age respectively. Recurrent self-limiting hepatitis developed later, and severe hepatic failure resulted in death of the first child. The second child visited was a 7.75 year old boy who had spondyloepiphyseal dysplasia and subclinical hypothyroidism besides DM and recurrent hepatitis. We suggested WRS for this patient, and it was confirmed by identification of a novel homozygous missense mutation (Q166R) in exon 3 of the EIF2AK3 gene. The aim of this report is to remind the possibility of WRS in isolated neonatal diabetes; while, the other clinical manifestations of this syndrome including its major symptom of recurrent hepatitis may appear later.

Effect of storage media and time on the fracture toughness of resin-based luting cements

BACKGROUND

Resin-based cements are brittle materials and the major shortcomings of these materials are manifested in their sensitivity to flaws and defects. Although various mechanical properties of resin luting cements have been described, few fracture toughness test data for resin-based luting cements using the short rod design have been published.

METHODS

Specimens were prepared from five resin luting cements. For each material a total of 36 disc-shaped specimens were prepared using a custom-made mould. Specimens were randomly divided into six groups of six, immersed in two solutions: distilled water and 0.01 mol/L lactic acid at 37 °C for 24 hours, 1 month or 3 months. The specimens were loaded using a universal testing machine. The maximum load at specimen failure was recorded and the K(Ic) (MPa. M 0.5) was calculated.

RESULTS

There was a relationship between material, storage solution and time (p < 0.05). Nexus 3 showed the highest K(Ic) followed by Panavia F, Calibra, Smart Cem2 and seT.

CONCLUSIONS

The fracture toughness of the resin luting cements was affected by both time and storage solution. Comparable fracture toughness of conventional resin cement and self-adhesive resin cements was observed.

Cross-sectional reference values for height, weight and body mass index of schoolchildren living in Tehran, Iran

AIM

The aim of the study was to create reference values for weight, height and body mass index (BMI) of school children living in Tehran. METHOD AND SAMPLES: The study subjects consisted of 1,420 girls between 6 and 17 years of age and 1,515 boys between 6 and 15 years of age. Samples were collected by a multistage sampling method from schools in different areas of Tehran. All participants were established to be healthy and their height, weight and BMI evaluated. Reference standard values estimated by the LMS method using LMS Light software and 3rd, 5th, 10th, 25th, 50th, 75th, 90th, 97th and 85th (only for BMI) centiles were constructed and the results compared with US reference values.

RESULTS

The centiles provided a good fit to the data. In boys, there were some significant differences of mean standard deviation scores (SDS) of height and BMI from zero, but there were no significant differences in weight. In girls, the mean SDS of height, weight and BMI were significantly lower than zero, especially for 7-9 years of age. Among 12-13-year-old girls, the mean SDS of height, weight and BMI came closer to zero, and the differences were not significant. Thereafter, although girls seemed to be shorter than US reference measures, their weight and BMI did not differ from reference values significantly.

CONCLUSION

Our results for boys between 6 and 15 years are comparable with US reference values; however, the US reference values, especially for height, are not applicable for Iranian girls between 6 and 17 years.

Ethnic-specific distribution of mutations in 716 patients with congenital adrenal hyperplasia owing to 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD) occurs worldwide. The most common mutations in the CYP21A2 gene in 716 unrelated patients were analyzed and the mutations were grouped by ethnicity, as defined through self-declaration corroborated by review of pedigrees extending to two or three generations. Prevalent allelic mutations and genotypes were found to vary significantly among ethnic groups, and the predominance of the prevalent mutations and genotypes in several of these populations was significant. There are ethnic-specific mutations in the CYP21A2 gene. A large deletion is prevalent in the Anglo-Saxons; a V281L (1685 G to T) mutation is prevalent in Ashkenazi Jews; an R356W (2109 G to A) mutation is prevalent in the Croatians; an IVS2 AS -13 (A/C to G) mutation is prevalent in the Iranians and Yupik-speaking Eskimos of Western Alaska; and a Q318X (1994 C to T) mutation is prevalent in East Indians. Genotype/phenotype non-correlation was seen when at least one IVS2 AS -13 (A/C to G) mutation in the CYP21A2 gene was present.

A non-invasive gating device for continuous drug delivery that allows control over the timing and duration of spontaneous opiate withdrawal

Opiate dependence in laboratory animals is commonly induced by two methods: (1) subcutaneous (s.c.) insertion of morphine pellets, and (2) daily injections of increasing doses of opiates. While both of these methods reliably induce opiate dependence, they do not allow one to discontinue, and subsequently reestablish steady state opiate plasma levels with minimal invasive procedures. We developed an "ON-OFF" gating device for repeatedly and non-invasively turning ON or OFF opiate delivery by standard osmotic minipumps. The reliability of this "device" was tested utilizing naloxone (NAL)-precipitated somatic signs of withdrawal, and body mass index (BMI) as measures of withdrawal. Rats were implanted with osmotic minipumps equipped with the gating device, containing heroin (2.66 mg per day). Three days after surgery, somatic signs of withdrawal were precipitated every 48 h by NAL (0.3mg/kg), with minipumps gated ON or OFF. For BMI, spontaneous withdrawal was repeatedly (three times) induced by turning OFF and ON the gating devices every 48 h. Body weights were measured every 4h from 06:00 to 22:00 h daily. Results show that NAL precipitated intense somatic signs of withdrawal when gating devices were ON. This effect was almost abolished when gating devices were OFF. BMI rapidly decreased after the gating devices were turned OFF with maximum weight loss occuring 12 h post-OFF position, and gradually returning to baseline values after gating devices were turned back ON. These results demonstrate the validity of the "ON-OFF" gating device for non-invasively and repeatedly inducing physical dependence to opiates over a prolonged time.

IDDM and early exposure of infant to cow's milk and solid food

Associations studies were attempted between the type of feeding, duration, and time of starting of solid foods in infancy and the incidence of insulin-dependent diabetes mellitus (IDDM). The study subjects comprised 52 IDDM patients and 52 control subjects matched for sex, age, social status, country, geographical location and selected from pediatric departments of different hospitals in Tehran. Diabetic children (21 boys, 31 girls) were of the ages of 1.5 to 14 years. Information about the pattern of their feeding at the first two years of life were collected through questionnaires administered to the mothers. The questionnaire was designed to evaluate the duration of complete or partial breast-feeding and the age at which dietary products containing cow's milk were introduced into the diet. A large proportion of the diabetic children rather than the control children had been breast-fed, and the risk of IDDM among children who had not been breast-fed was below unity. No significant difference in the duration of breast-feeding was observed between diabetic and control group. Our data do not support the existence of a protective effect of breast-feeding on the risk of IDDM, nor do the data indicate that early exposure to cow's milk and dairy products has any influence on the development of IDDM.

Contribution of sex and genetics to neuroendocrine adaptation to stress in mice

Male and female C57BL/6 (B6) and DBA/2 (D2) mice were subjected to either acute or 5 days of repeated restraint in ventilated, 50 ml centrifuge tubes. Control animals were not disturbed. The acute restraint animals were killed immediately following 15, 30 or 60 min of restraint and blood collected for corticosterone (CORT) analysis. The results of the acute restraint procedure revealed a strain difference in time to peak CORT in plasma with D2 animals showing an earlier peak. The males of both strains evinced similar maximum response and similar to B6 females; however, the D2 females showed a 2-fold greater CORT response than did the B6 females. Repeated restraint consisted of 5 days of 12 h in the tubes. At the end of 5 days, the animals were weighted and adrenalectomized in preparation for determination of brain corticosteroid receptors. Upon sacrifice, brains, thymus, adrenals and blood were harvested, the last for corticosteroid binding globulin (CBG). Five days of repeated restraint produced body weight loss in both strains, with B6s less affected than D2s. Repeated restraint reduced the mass of the adrenals in the B6s only. Restraint also reduced the mass of the thymus in both strains and sexes, but to a greater extent in the B6s. Plasma CBG densities were also sensitive to restraint, but only in females, showing a restraint-related decrease. Repeated restraint had no effect on hippocampal glucocorticoid or mineralocorticoid receptors; however for the latter, we observed significant strain and sex effects with D2 having higher Bmax than B6 and females having higher Bmax than males. In the pituitary, glucocorticoid receptors (GR) were reduced by repeated restraint in males, but increased in females, especially in the B6. These findings lend preliminary evidence for involvement of sex and genetics as sources of individual differences in bioadaptation to stress.

Examination of genotype and phenotype relationships in 14 patients with apparent mineralocorticoid excess

Apparent mineralocorticoid excess (AME) is a genetic disorder causing pre- and postnatal growth failure, juvenile hypertension, hypokalemic metabolic alkalosis, and hyporeninemic hypoaldosteronism due to a deficiency of 11 beta-hydroxysteroid dehydrogenase type 2 enzyme activity (11 beta HSD2). The 11 beta HSD2 enzyme is responsible for the conversion of cortisol to the inactive metabolite cortisone and therefore protects the mineralocorticoid receptors from cortisol intoxication. Several homozygous mutations are associated with this potentially fatal disease. We have examined the phenotype, biochemical features, and genotype of 14 patients with AME. All of the patients had characteristic signs of a severe 11 beta HSD2 defect. Birth weights were significantly lower than those of their unaffected sibs. The patients were short, underweight, and hypertensive for age. Variable damage of one or more organs (kidneys, retina, heart, and central nervous system) was found in all of the patients except one. The follow-up studies of end-organ damage after 2-13 yr of treatment in six patients demonstrated significant improvement in all patients. The urinary metabolites of cortisol demonstrated an abnormal ratio with predominance of cortisol metabolites, i.e. tetrahydrocortisol plus 5 alpha-tetrahydrocortisol/tetrahydrocortisone was 6.7-33, whereas the normal ratio is 1.0. Infusion of [11-3H]cortisol resulted in little release of tritiated water, indicating the failure of the conversion of cortisol to cortisone. Thirteen mutations in the HSD11B2 gene have been previously published, and we report three new genetic mutations in two patients, one of whom was previously unreported. All of the patients had homozygous defects except one, who was a compound heterozygote. Our first case had one of the most severe mutations, resulting in the truncation of the enzyme 11 beta HSD2, and died at the age of 16 yr while receiving treatment. Three patients with identical homozygous mutations from different families had varying degrees of severity of clinical and biochemical features. Due to the small number of patients with identical mutations, it is difficult to correlate genotype with phenotype. In some cases, early and vigilant treatment of AME patients may prevent or improve the morbidity and mortality of end-organ damage such as renal or cardiovascular damage and retinopathy. The outcome of treatment in more patients may establish the efficacy of treatment.

Distribution and clearance of cocaine in brain is influenced by genetics

The purpose of this study was to examine the pharmacokinetics of cocaine in two inbred mouse strains, C57BL/6 (B6) and DBA/2 (D2). Male and female mice were administered 30 mg kg(-1) cocaine IP and killed after 5, 15, 30, or 60 minutes postinjection. Brains were removed quickly and assayed for total brain cocaine concentration. Quantification of cocaine was conducted using gas chromatography and mass spectrometry. The results of this study revealed a strain difference in total brain cocaine kinetics. Specifically, we observed that at 5 min onward, B6 mice cleared cocaine from the brain with a t1/2 estimated at 22.3 min, while distribution in D2 mice appeared to be incomplete until 15 min with a subsequent t1/2 estimated at 11.2 min. These results show that despite faster clearance by D2 mice, the prolonged time to distribution in this strain may help explain why D2 mice show initial greater locomotor activation by cocaine, compared to B6s.