A Stk4-Foxp3-NF-κB p65 transcriptional complex promotes Treg cell activation and homeostasis

The molecular programs involved in regulatory T (T_reg) cell activation and homeostasis remain incompletely understood. Here, we show that T cell receptor (TCR) signaling in T_reg cells induces the nuclear translocation of serine/threonine kinase 4 (Stk4), leading to the formation of an Stk4-NF-κB p65-Foxp3 complex that regulates Foxp3- and p65-dependent transcriptional programs. This complex was stabilized by Stk4-dependent phosphorylation of Foxp3 on serine-418. Stk4 deficiency in T_reg cells, either alone or in combination with its homolog Stk3, precipitated a fatal autoimmune lymphoproliferative disease in mice characterized by decreased T_reg cell p65 expression and nuclear translocation, impaired NF-κB p65-Foxp3 complex formation, and defective T_reg cell activation. In an adoptive immunotherapy model, overexpression of p65 or the phosphomimetic Foxp3^S418E in Stk3/4-deficient T_reg cells ameliorated their immune regulatory defects. Our studies identify Stk4 as an essential TCR-responsive regulator of p65-Foxp3-dependent transcription that promotes T_reg cell-mediated immune tolerance.

Investigation of the relationship between serum sclerostin and dickkopf-1 protein levels with bone turnover in children and adolescents with type-1 diabetes mellitus

OBJECTIVES

Diabetes mellitus (DM) is widely known to have a detrimental effect on bone health and is associated with increased fracture risk. Recently, the Wnt/beta-catenin signaling pathway and its inhibitors sclerostin and dickkopf-1 (Dkk-1) were found to be involved in the control of bone mass. The present study aimed to measure serum sclerostin and Dkk-1 protein levels in children and adolescents with type-1 DM and compare with other bone turnover markers and bone mineral density (BMD).

METHODS

This study was performed on 40 children and adolescents with type-I DM and 40 healthy children and adolescents. Anthropometric measurements and pubertal examination were done. In addition to laboratory analysis, dickkopf-1, sclerostin, cross-linked N-telopeptides of type I collagen (NTx), bone alkaline phosphatase (bALP), and osteocalcin levels were studied. BMD of the participants was measured by calcaneus ultrasonography.

RESULTS

Dickkopf-1 levels of the children and adolescents with type-1 DM were significantly higher, vitamin D, NTx, osteocalcin, and phosphorus levels were significantly lower than those of the controls (p<0.001). Fasting blood glucose, HbA1c, and insulin were significantly higher in the type 1 DM group (p<0.01).

CONCLUSIONS

Both bone remodeling and its compensatory mechanism bone loss are lower in children and adolescents with type-1 DM than in the controls. Also, higher levels of Dkk-1 play a role in decreased bone turnover in these patients. Since Dkk-1 and sclerostin seem to take a role in treating metabolic bone diseases in the future, we believe that our findings are significant in this respective.

Relationship of acanthosis nigricans with metabolic syndrome in obese children

OBJECTIVES

Acanthosis nigricans is a skin symptom in obesity that helps to identify patients at high risk for dyslipidemia, hypertension, insulin resistance, and diabetes. It is the most important complication of obesity in metabolic syndrome. Studies investigating the relationship between acanthosis nigricans and metabolic syndrome in obese children are insufficient. In our study, the relationship of acanthosis nigricans and metabolic syndrome was evaluated in children.

METHODS

Obese children aged between 6 and 18 years old, who were examined in the pediatric endocrinology outpatient clinic, were included. The patients' anthropometric measurements and laboratory results were recorded. Modified IDF (International Diabetes Federation) criteria for children were used in metabolic syndrome classification.

RESULTS

A hundred and forty-eight obese children were evaluated. The mean age of the cases was 11.91 ± 2.94 years old. Of the cases, 56.1% were female (n=83) 43.9% (n=65) were male. In 39.9% (n=59) of cases, acanthosis nigricans was determined. Acanthosis nigricans was mostly located in the axillary area (27.1%) and the neck (16.9%). In 55.9% of the cases, it was located in more than one area. The relation of regionally detected acanthosis nigricans and metabolic syndrome was not significant (p=0.291). Metabolic syndrome was detected in 14% of 136 patients according to IDF criteria. Acanthosis nigricans and metabolic syndrome combination was present in 27.7%; however, 6.7% of the metabolic syndrome patients did not have acanthosis nigricans. There was a strong relation between metabolic syndrome and the presence of acanthosis nigricans (p=0.003).

CONCLUSIONS

In our study, a correlation between acanthosis nigricans and metabolic syndrome was detected. Acanthosis nigricans is a skin sign that can be easily detected by clinician. It is an important and easy-to-detect dermatosis that helps determine patients at risk of metabolic syndrome in obese children.

General properties of autoimmune thyroid diseases and associated morbidities

Background Autoimmune thyroid diseases (ATDs) can be classified into two basic diseases: Graves' disease (GD) and Hashimoto's thyroiditis (HT). Here, we review the effectiveness of laboratory and imaging methods used for the early diagnosis of ATD and draw attention to methods that may improve screening. Methods Retrospective data of 142 patients diagnosed with ATD between January 2010 and December 2015 at our paediatric endocrinology clinic were used. Sociodemographic characteristics, clinical findings, treatments and follow-up data of patients were statistically evaluated. Results Of the ATD cases, 81% (n = 115) were female. The median age was 12.5 ± 3.5 (range 1-17) years and 91% (n = 129) of patients were in puberty. There was a significant positive correlation between the height (standard deviation score) and follow-up time for patients with HT (r = 0.156, p < 0.01). Thyroglobulin antibody (TgAb) positivity was found in 75% (45/60) of females with a positive maternal ATD history (p = 0.045). Thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4) values were significantly altered during the treatment follow-up period in female patients with GD and HT, while only fT4 values were found to be significantly altered in boys with HT. Conclusion Although GD and HT have similar mechanisms, they differ in terms of treatment duration and remission and relapse frequencies. Ultrasonography (USG) screening is a non-invasive procedure that is suitable for all patients with ATD. Based on our results, TgAb could be useful in the screening of girls with a history of maternal ATD.

The relationship of periaortic fat thickness and cardiovascular risk factors in children with Turner syndrome

Children with Turner syndrome (TS) have a broad range of later health problems, including an increased risk of cardiovascular morbidity and mortality. The aim of this study was to evaluate the relationship between periaortic fat thickness (PAFT) and metabolic and cardiovascular profiles in children with TS. Twenty-nine TS and 29 healthy children and adolescents were enrolled in the study. Anthropometric measurements, pubertal staging, and blood pressure measurements were performed. Fasting serum glucose, insulin, and lipid profile were measured. Periaortic fat thickness was measured using an echocardiography method, which has not previously been applied in children with TS. No difference was found between TS and control subject (CS) in age, weight, waist/hip ratio, HDL cholesterol and LDL cholesterol levels. However, in TS subjects, total cholesterol (p = 0.045) was greater than that in controls. It was determined that 13.7 % (N: 4) of TS subjects had dyslipidemia. Mean fasting glucose, fasting insulin, QUICK-I, HOMA, and FGIR index were similar in TS and in CS, whereas 17.2 % (N: 5) of TS subjects had insulin resistance (IR) and 13.7 % (N: 4) had impaired glucose tolerance. Six subjects (20.6 %) were diagnosed as hypertensive. Periaortic fat thickness was significantly higher in the TS group (p < 0.001) (0.1694 ± 0.025 mm in the TS group and 0.1416 ± 0.014 mm in the CS group) In children with TS, PAFT was positively correlated with fasting insulin, body mass index, and diastolic blood pressure. Our results provide additional evidence for the presence of subclinical cardiovascular disease in TS. In addition to existing methods, we recommend the measurement of periaortic fat thickness in children with TS to reveal the presence of early atherosclerosis.

Is there a relationship between cardiovascular risk factors and dehydroepiandrosterone sulfate levels in childhood obesity?

AIM

In this study, parameters of metabolic syndrome and dehydroepiandrosterone sulfate (DHEAS) levels in obese children and adolescents were evaluated and the associations between these factors were analyzed.

METHOD

One hundred obese and 40 healthy children/adolescents were included in the study. Pubertal stages, anthropometric and blood pressure measurements were recorded. Levels of fasting serum lipids, glucose, insulin, and DHEAS, and liver function tests were determined. Carotid intima-media thickness (CIMT) was measured using two-dimensional echocardiography. Steatorrhoeic hepatosis was evaluated using abdominal ultrasonography in the obese group.

RESULTS

Mean body weight, body mass index, waist, hip circumference, waist/hip ratio, homeostatic model assessment of insulin resistance, triglycerides, high-density lipoprotein cholesterol, alanine transferase, DHEAS, and CIMT values were significantly higher in the obese group than in the controls. DHEAS levels were found to be positively correlated with waist circumference, waist/hip ratio, and CIMT.

CONCLUSION

Early determination of metabolic and cardiac dysfunction in obese children is important for the prevention of future complications. Since in this study we found a strong association between DHEAS levels and obesity-related metabolic and cardiovascular risk factors, we believe that this may lead to increased interest in further studies of DHEAS in the search for new treatment approaches.

Association between vitamin D level and cardiovascular risk in obese children and adolescents

BACKGROUND

The aim of our study was to evaluate the associations between vitamin D deficiency, the atherosclerosis and metabolic syndrome.

METHODS

Two hundred and forty-seven obese children and adolescents, 8-16 years of age (body mass index>95 p) were included in the study. Anthropometric measurements, blood pressure measurements, lipid profile, vitamin D level and carotid intima media thickness (c-IMT) were measured. MS was diagnosed according to IDF criteria.

RESULTS

The prevalance of vitamin D deficieny in obese children and adolescent was 46.6%. Low levels of vitamin D were associated with increased carotis intima media thickness and metabolic syndrome (p=0.03, p=0.04, respectively). For clinical cardiovascular risk factors, mutivariable regression analyses showed that low vitamin D level was best predictor of c-IMT.

CONCLUSIONS

In this study we showed an association between low vitamin D status and atherosclerosis independent of traditional risk factors in obese children and adolescents.

Impaired systolic blood dipping and nocturnal hypertension: an independent predictor of carotid intima-media thickness in type 1 diabetic patients

OBJECTIVE

Type 1 diabetes in children predicts a broad range of later health problems including an increased risk of cardiovascular morbidity and mortality. This study aimed to evaluate whether nocturnal hypertension and impaired nocturnal dipping affect atherosclerosis in children and adolescents with type 1 diabetes and to investigate the relationship between atherogenic risk factors and carotid intima-media thickness (CIMT).

METHODS

One hundred fifty-nine type 1 diabetic patients and 100 healthy controls were included in the study. We investigated metabolic and anthropometric parameters such as body mass index (BMI), waist circumference, fasting glucose and insulin, serum lipids, 24h ambulatory blood pressure monitoring (ABPM), and CIMT and compared these with those in control subjects (CS).

RESULTS

No difference was found between type 1 diabetic patients and CS in age, weight, waist/hip ratio, triglyceride, HDL-cholesterol level. However in children with type 1 diabetes, total cholesterol (p=0.016),and LDL-cholesterol (p=0.002) levels and CIMT (P<0.001) were greater than those of controls. It was determined that 10% of type 1 diabetic patients had dyslipidemia. In 23.2% of type 1 diabetic patients, ABPM showed arterial hypertension. CIMT was significantly higher in the hypertensive group than in the non-hypertensive group (P=0.003). Twenty-three (14.4%) diabetic patients had nocturnal hypertension. CIMT was significantly greater in the nocturnal hypertensive group (p=0.023). Mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) dipping was significantly different in diabetic patients (P<0.001). CIMT was correlated positively with Hba1c (r=0.220, p=0.037), and negatively with SBP dipping (r=-0.362, p=0.020) in the diabetic patients. In stepwise regression analysis, Hba1c and SBP dipping emerged as a significant predictor of CIMT (β=0.300, p=0.044, β=0.398 p=0.009) contributing to 15.58% of its variability.

CONCLUSION

These results provide additional evidence for the presence of subclinical cardiovascular disease (CVD) and its relation to hypertension in type 1 diabetic patients. They also indicate a significant relation between nocturnal hypertension, SBP dipping and increased arterial stiffness. It is also important to note that our findings reveal significant relationships between HBA1c cardiovascular changes and underline the importance of glucose control to predict CVD.

Pentoxifylline treatment for protecting diabetic retinopaty in children with type 1 diabetes

OBJECTIVE

The purpose of this study was to determine whether oral pentoxifylline (PTX) would improve retinal microvascular hemodynamics in children with type 1 diabetes mellitus (DM).

PATIENTS AND METHODS

Non-invasive ultrasonographic measurements were made in 56 type 1 diabetic patients. The diabetic patients were matched first in terms of age, diabetes duration, then one individual within each pair was randomized into a pentoxifylline group and a control group. Pentoxifylline was administered for 6 months. We investigated the change of peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI), and resistivity index (RI) of central retinal artery (CRA) at 6 months after pentoxifylline. We investigated the relationship between PI, RI and carotide cross-sectional compliance (C-CSC).

RESULTS

In comparison to changes in CRA measurements between the two groups, the pentoxifylline treatment group had significantly lower PI values (p=0.01). The RI, PSV and EDV were lower in pentoxifylline group but not statistically different. There was a positive correlation between CRA PSV and carotid Vmax (cm/s) (r=0.29, p=0.02) and also C-CSC (r=0.27, p=0.03). In addition, there was a positive correlation between PI and C-CSC (r=0.3, p=0.02). In the pentoxifylline group there was a significant reduction in systolic blood pressure, diastolic blood pressure, microalbuminuria and an increase in HDL level.

CONCLUSION

Our results suggest that pentoxifylline may have a protective action for diabetic retinopathy and might modulate risk factors for atherosclerosis in type 1 diabetes.