Increased levels of plasma neudesin in adult growth hormone deficiency and their relationship with plasma liver-expressed antimicrobial peptide-2 levels: a cross-sectional study

PURPOSE

Adult growth hormone deficiency (aGHD) is characterized by an altered metabolic profile and increased cardiovascular risk. Neudesin is a newly discovered protein mainly secreted from adipose tissue and brain, under evaluation for its possible activity as a negative regulator of energy expenditure. Liver-expressed antimicrobial peptide (LEAP)-2 is a competitive antagonist of ghrelin on its receptor. An observational cross-sectional study was performed to test the hypothesis that plasma neudesin levels may be modified in aGHD. Given the role played in the energy balance, any possible relationships between neudesin, LEAP-2 and metabolic and anthropometric parameters were evaluated.

SUBJECTS AND METHODS

Thirty-eight patients were included: 18 aGHD patients (7 females and 11 males, aged 59.7 ± 2.6 years, BMI 30.2 ± 2.2 kg/m²); 20 healthy controls (12 females and 8 males, aged 47.1 ± 2.5 years, BMI 24.1 ± 0.9 kg/m²). All patients were evaluated for glucose, insulin, HOMA and QUICKI index, total/LDL/HDL cholesterol, triglycerides, uric acid, and IGF-1. Plasma neudesin, LEAP-2, and ghrelin were measured by ELISA. Fat mass was evaluated by DEXA.

RESULTS

Neudesin levels were significantly higher in aGHD versus controls. We confirmed the finding of significantly lower ghrelin levels and significantly higher LEAP-2/ghrelin ratio in aGHD patients and found a significant direct correlation between neudesin and LEAP-2 levels. A significant direct correlation between neudesin and fat mass percentage was found in the whole population.

CONCLUSION

These results suggest the onset of adaptive responses to an altered metabolic picture in aGHD. The changes in two distinct pathways that modulate food intake and the still limited knowledge about neudesin suggest future developments in this field.

The assessment of maternal and umbilical cord neudesin levels in pregnancies with gestational diabetes mellitus

Gestational diabetes mellitus (GDM) occurs due to the inability to adapt to physiologically observed changes in carbohydrate metabolism during pregnancy. Neudesin is a multi-functional secreted protein suggested to have a crucial regulator role in energy and carbohydrate metabolism. This study aimed to evaluate maternal serum and umbilical cord neudesin levels in pregnancies with GDM. Twenty-four singleton pregnancies with GDM were compared with gestational age-matched 23 uncomplicated pregnancies in this cross-sectional study. In comparison to the control group, significantly higher maternal serum and umbilical cord neudesin levels were observed in pregnancies with GDM (p < .001). Maternal serum and umbilical cord neudesin levels were also significantly positively correlated with maternal serum insulin levels and HOMA-IR values in the study group (p < .001). Neudesin, with its regulator role in carbohydrate metabolism, may be a contributing factor in the pathophysiology of GDM and may be a target of strategies for the prevention and treatment of GDM.Impact statementWhat is already known on this subject? Progressive changes in carbohydrate metabolism occur in normal pregnancy to provide continuous nutritional supply to the developing foetus and pregnant woman. When these progressive metabolic changes cannot be compensated, gestational diabetes mellitus (GDM) occurs.What the results of this study add? This is the first study to provide information about maternal serum and umbilical cord neudesin levels in pregnancies with GDM. This study observed that the serum levels of neudesin, which is suggested to have a regulator role in carbohydrate metabolism, were increased in pregnant women with GDM.What the implications are of these findings for clinical practice and/or future research? Neudesin may contribute to impaired carbohydrate metabolism in pregnancies with GDM and can be the subject of further studies on the prevention and treatment of GDM.

Serum and cerebrospinal fluid Neudesin concentration and Neudesin Quotient as potential circulating biomarkers of a primary brain tumor

Background

Despite the previously suggested role of Neudesin in tumorigenesis and its potential as a novel target for the treatment of cancers, its prognostic value has never been examined. Thus, the aim of the study was to evaluate Neudesin concentrations in primary brain tumor patients and make a comparison with non-tumoral individuals.

Methods

Cerebrospinal fluid (CSF) and serum Neudesin concentration was evaluated by means of the ELISA method.

Results

The total group of brain tumor patients had statistically lower serum Neudesin concentrations compared to the non-tumoral group (P = 0.037). The meningeal tumor subgroup also had statistically lower serum Neudesin concentrations compared to the non-tumoral group (P = 0.012). The Astrocytic brain tumor subgroup had significantly higher CSF Neudesin concentrations compared to the non-tumoral group (P = 0.046). Neudesin Quotient (CSF concentration divided by serum concentration) in the astrocytic brain tumor subgroup was statistically higher compared to the non-tumoral group (P = 0.023). Males had statistically lower concentrations of the serum Neudesin compared to females (P = 0.047). Univariate linear regression analysis revealed that for women the serum Neudesin concentration was 1.53 times higher than for men. In the model of multivariate linear regression analysis, predictor variables influencing serum Neudesin concentrations included CSF Neudesin concentration and the Neudesin Quotient, if other model parameters are fixed. The developed model explains 82% of the variance in serum Neudesin concentration. Both linear regression models, univariate and multivariate, pointed to fewer factors with a potential to influence the Neudesin Quotient compared to serum Neudesin concentration.

Conclusions

In astrocytic brain tumor patients Neudesin concentrations within the cerebrospinal fluid are higher compared with non-tumoral individuals. Serum Neudesin concentration strongly correlates with its CSF level. In primary brain tumor patients serum Neudesin concentration is clearly gender-dependent. Linear regression models pointed to fewer factors that may influence the Neudesin Quotient value, which suggests it is a better biomarker of astrocytic brain tumors than serum and CSF Neudesin concentrations alone.