Association between augmented levels of the gut pro-hormone Proneurotensin and subclinical vascular damage.

Elevated levels of the gut pro-hormone Proneurotensin (proNT) have been found to predict development of cardiovascular disease. However, it is still unknown whether higher proNT levels are associated with subclinical vascular damage. Herein, we investigated the relationship between higher proNT concentrations and augmented pulse pressure (PP) and carotid intima-media thickness (cIMT), indicators of increased arterial stiffness and subclinical atherosclerosis, respectively. Clinical characteristics, PP and cIMT were evaluated in 154 non-diabetic individuals stratified into tertiles according to fasting serum proNT concentrations. We found that, subjects with higher proNT levels exhibited a worse lipid profile and insulin sensitivity, increased C-reactive protein levels, along with higher values of PP and cIMT as compared to the lowest proNT tertile. Prevalence of elevated PP (≥ 60 mmHg) and subclinical carotid atherosclerosis (IMT > 0.9 mm) was increased in the highest tertile of proNT. In a logistic regression analysis adjusted for several confounders, subjects with higher proNT levels displayed a fivefold raised risk of having elevated PP values (OR 5.36; 95%CI 1.04-27.28; P = 0.05) and early carotid atherosclerosis (OR 4.81; 95%CI 1.39-16.57; P = 0.01) as compared to the lowest proNT tertile. In conclusion, higher circulating levels of proNT are a biomarker of subclinical vascular damage independent of other atherosclerotic risk factors.

Neurotensin accelerates atherosclerosis and increases circulating levels of short-chain and saturated triglycerides.

BACKGROUND AND AIMS: Obesity and type 2 diabetes are significant risk factors for atherosclerotic cardiovascular disease (CVD) worldwide, but the underlying pathophysiological links are poorly understood. Neurotensin (NT), a 13-amino-acid hormone peptide, facilitates intestinal fat absorption and contributes to obesity in mice fed a high-fat diet. Elevated levels of pro-NT (a stable NT precursor produced in equimolar amounts relative to NT) are associated with obesity, type 2 diabetes, and CVD in humans. Whether NT is a causative factor in CVD is unknown. METHODS: Nt+/+ and Nt-/- mice were either injected with adeno-associated virus encoding PCSK9 mutants or crossed with Ldlr-/- mice and fed a Western diet. Atherosclerotic plaques were analyzed by en face analysis, Oil Red O and CD68 staining. In humans, we evaluated the association between baseline pro-NT and growth of carotid bulb thickness after 16.4 years. Lipidomic profiles were analyzed. RESULTS: Atherosclerotic plaque formation is attenuated in Nt-deficient mice through mechanisms that are independent of reductions in circulating cholesterol and triglycerides but associated with remodeling of the plasma triglyceride pool. An increasing plasma concentration of pro-NT predicts atherosclerotic events in coronary and cerebral arteries independent of all major traditional risk factors, indicating a strong link between NT and atherosclerosis. This plasma lipid profile analysis confirms the association of pro-NT with remodeling of the plasma triglyceride pool in atherosclerotic events. CONCLUSIONS: Our findings are the first to directly link NT to increased atherosclerosis and indicate the potential role for NT in preventive and therapeutic strategies for CVD.

A study on serum pro-neurotensin (PNT), furin, and zinc alpha-2-glycoprotein (ZAG) levels in patients with acromegaly.

PURPOSE: Acromegaly caused by growth hormone cell adenoma is commonly associated with abnormal glucolipid metabolism, which may result from changes in adipocytokine secretion. This study aims to investigate serum adipokine levels, including pro-neurotensin (PNT), furin, and zinc alpha-2-glycoprotein (ZAG), in acromegalic patients and the correlation between the levels of these three adipokines and GH levels and glucolipid metabolism indices. METHODS: Sixty-eight acromegalic patients and 121 controls were included, and their clinical data were recorded from electronic medical record system. Serum PNT, furin and ZAG levels were measured by ELISA. RESULTS: Serum PNT levels in acromegalic patients were significantly higher than controls (66.60 ± 12.36 vs. 46.68 ± 20.54 pg/ml, P < 0.001), and acromegaly was an independent influencing factor of PNT levels (P < 0.001). Moreover, subjects with the highest tertile of PNT levels had a close correlation with acromegaly (OR = 22.200, 95% CI 7.156 ~ 68.875, P < 0.001), even in Model 1 adjusted for gender and age and Model 2 adjusted for gender, age and BMI. Additionally, serum PNT levels were positively correlated with BMI (r = 0.220, P = 0.002) and triglycerides (TGs, r = 0.295, P < 0.001), and TGs were an independent influencing factor of serum PNT levels in acromegalic subjects (P < 0.001). Furthermore, serum PNT levels in obese acromegalic patients were significantly higher than those with normal BMI (P < 0.05). However, serum furin levels were lower in acromegalic patients than controls (0.184 ± 0.036 vs. 0.204 ± 0.061 ng/ml, P < 0.001). CONCLUSION: This study is the first to demonstrate that acromegalic patients have increased serum PNT levels. Moreover, serum PNT plays a potential role in abnormal lipid metabolism of acromegalic patients.

Elevated neurotensin levels among obese adolescents may be related to emotion dysregulation and impulsivity: a cross-sectional, case-control study.

BACKGROUND: In this study, we aimed to evaluate the serum neurotensin (NT) levels and their relationships with self-reported anxiety, emotion regulation skills and impulsivity in healthy and obese adolescents. METHODS: Adolescents who gained weight between 12- 17 years of age and who were above the 95th percentile (p) for body mass index (BMI) > 95p were compared with age- and gender-matched healthy adolescents with a BMI of 3-85 p. Anthropometric measurements were performed, and serum NT levels were analyzed with ELISA method in all participants. Barrat Impulsivity Scale-11 (BIS-11), Screen for Child Anxiety Related Disorders (SCARED) and Difficulties in Emotion Regulation Scale (DERS) were used for evaluating self-reported impulsivity, anxiety and emotion regulation. MANOVA with follow-up univariate ANOVAs (Bonferroni corrected) were used for group comparisons. P was set at 0.05 (two-tailed). RESULTS: Sixty-five obese and 65 healthy adolescents were included in the study. In the obese group, NT levels were significantly elevated compared to the control group. Self-reported emotion-regulation difficulties, anxiety and impulsivity were significantly elevated among obese adolescents. Serum NT levels among the obese group were positively correlated with emotion dysregulation and impulsivity scores. CONCLUSIONS: In this study, we found emotional dysregulation, anxiety, impulsivity, and serum NT levels were significantly elevated among obese adolescents compared to controls. NT levels in the obese group correlated with impulsivity and emotion dysregulation. Further studies should evaluate the potential role of NT in the etiology of psychopathology among adolescents who are obese.

Role of alpha-lipoic acid in counteracting paclitaxel- and doxorubicin-induced toxicities: a randomized controlled trial in breast cancer patients.

BACKGROUND AND OBJECTIVE: Paclitaxel and doxorubicin are associated with neurotoxicity and cardiotoxicity respectively. This study aimed at investigating the role of alpha-lipoic acid (ALA) in counteracting paclitaxel-induced neuropathy and doxorubicin-associated cardiotoxicity in women with breast cancer. PATIENTS AND METHODS: This randomized double-blind placebo-controlled prospective study included 64 patients with breast cancer who were randomized into control group (n = 32) which received 4 cycles of doxorubicin plus cyclophosphamide (every 21 days) followed by weekly doses of paclitaxel for 12 weeks plus placebo tablets once daily and ALA group (n = 32) which received the same chemotherapeutic regimen plus ALA 600 once daily for 6 months. Patients were assessed by National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE version 4.0) for grading of neuropathy and by 12-item neurotoxicity questionnaire (Ntx-12). The assessment included also echocardiography and evaluation of serum levels of brain natriuretic peptide (BNP), tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA), and neurotensin (NT). Data were analyzed by paired and unpaired t-test, Mann-Whitney U test, and chi-square test. RESULTS: As compared to placebo, ALA provoked significant improvement in NCI-CTCAE neuropathy grading and Ntx-12 score after the end of 9th and 12th weeks of paclitaxel intake (p = 0.039, p = 0.039, p = 0.03, p = 0.004, respectively). At the end of the chemotherapy cycles, ALA resulted in significant decline in serum levels of BNP, TNF-α, MDA, and neurotensin (p < 0.05) as compared to baseline data and placebo. CONCLUSION: Alpha-lipoic acid may represent a promising adjuvant therapy to attenuate paclitaxel-associated neuropathy and doxorubicin-induced cardiotoxicity in women with breast cancer. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03908528.

Plasma Proneurotensin and Prediction of Cause-Specific Mortality in a Middle-aged Cohort During Long-term Follow-up.

CONTEXT: Neurotensin is associated with cardiometabolic diseases but its role with mortality risk in humans is unknown. OBJECTIVE: This work aims to examine the prediction of proneurotensin (Pro-NT) with respect to total and cause-specific mortality in a middle-aged cohort. METHODS: In the population-based middle-aged cohort (n = 4632; mean age, 57 years) of the Malmö Diet and Cancer Study, Pro-NT was assessed and total as well as cause-specific mortality was studied. Main cause of death was based on the International Classification of Diseases. RESULTS: During a mean follow-up of 20 ±â€…3 years, 950 men and 956 women died. There was significantly increased mortality risk in individuals belonging to the highest quartile (Q) of Pro-NT (Q4, Pro-NT ≥ 149 pmol/L) compared with Qs 1 to 3 (Pro-NT < 149 pmol/L), hazard ratio (HR), 95% CI of 1.29 (1.17-1.42; P < .001). Data were adjusted for sex and age. No significant interaction was observed between Pro-NT and sex on mortality risk. Individuals within Q4 vs Qs 1 to 3 had an HR of 1.41 (95% CI, 1.18-1.68; P < .001) for death due to cardiovascular disease (n = 595/4632); 2.53 (95% CI, 1.37-4.67; P = .003), due to digestive tract disease (n = 42/4632), 1.62 (95% CI, 1.04-2.52; P = .032) due to mental and behavioral disease (n = 90/4632); and 1.91 (95% CI, 1.15-3.19; P = .013) due to unspecific causes (n = 64/4632). There was no significant relationship between Pro-NT and deaths due to cancer, infections, neurological, or other causes. Adjustment for cardiovascular risk factors only marginally changed these results. CONCLUSION: The relationship between Pro-NT and total mortality risk was mainly driven by cardiovascular mortality, but high Pro-NT also predicts death from digestive, mental, and behavioral disease and deaths attributed to unspecific causes.

Neurotensin secretion after Roux-en-Y gastric bypass, sleeve gastrectomy, and truncal vagotomy with pyloroplasty.

OBJECTIVE: Neurotensin (NT) is released from enteroendocrine cells and lowers food intake in rodents. We evaluated postprandial NT secretion in humans after surgeries associated with accelerated small intestinal nutrient delivery, and after Roux-en-Y gastric bypass (RYGB) when glucagon-like peptide-1 (GLP-1) signalling and dipeptidyl peptidase 4 (DPP-4) were inhibited, and during pharmacological treatments influencing entero-pancreatic functions. METHODS: We measured NT concentrations in plasma from meal studies: (I) after truncal vagotomy with pyloroplasty (TVP), cardia resection +TVP (CTVP), and matched controls (n = 10); (II) after RYGB, sleeve gastrectomy (SG), and in matched controls (n = 12); (III) after RYGB (n = 11) with antagonism of GLP-1 signalling using exendin(9-39) and DPP-4 inhibition using sitagliptin; (IV) after RYGB (n = 11) during a run-in period and subsequent treatment with, sitagliptin, liraglutide (GLP-1 receptor agonist), verapamil (calcium antagonist), acarbose (alpha glucosidase inhibitor), and pasireotide (somatostatin analogue), respectively. RESULTS: (I) NT secretion was similar after TVP/CTVP (p = 0.9), but increased vs. controls (p < 0.0001). (II) NT secretion was increased after RYGB vs. SG and controls (p < 0.0001). NT responses were similar in SG and controls (p = 0.3), but early postprandial NT concentrations were higher after SG (p < 0.05). (III) Exendin (9-39) and sitagliptin did not change NT responses vs placebo (p > 0.2), but responses were lower during sitagliptin vs. exendin(9-39) (p = 0.03). (IV) Pasireotide suppressed NT secretion (p = 0.004). Sitagliptin tended to lower NT secretion (p = 0.08). Liraglutide, verapamil, and acarbose had no effect (p > 0.9). CONCLUSION: Neurotensin secretion is increased after surgeries associated with accelerated gastric emptying and lowered by pasireotide.

High pro-neurotensin levels in individuals with type 1 diabetes associate with the development of cardiovascular risk factors at follow-up.

AIMS: Neurotensin (NT) is a gut hormone that promotes lipids absorption and controls appetite. Elevated circulating pro-NT, the stable precursor of NT, is associated with cardiovascular (CV) disease, metabolic syndrome (MS) and type 2 diabetes (T2D). Features of MS and insulin resistance are reported also in type 1 diabetes (T1D), with detrimental impact on the overall CV risk profile. Aims of the study were to evaluate plasma pro-NT in T1D patients and to test whether its levels are associated with and/or predictive of CV risk factors and overall risk profile. METHODS: For this longitudinal retrospective study, we analyzed clinical data from 41 T1D individuals referring to the diabetes outpatient clinics at Sapienza University of Rome, Italy, collected at the baseline and after 10 years. Fasting plasma pro-NT levels were measured in T1D subjects at the baseline and in 34 age-, sex-, BMI-comparable healthy individuals recruited in the same period. RESULTS: Pro-NT did not differ significantly between patients and controls (median[range] pro-NT: 156.3 [96.6-198.2] vs. 179.4 [139.7-230.7] pmol/L, p = 0.26). In T1D, greater fasting pro-NT associated with poor glycemic control at baseline and predicted increased waist circumference, reduced insulin sensitivity, dyslipidemia and hypertension at 10-year follow-up. High pro-NT predicted 10-year very-high CV risk with adjusted OR = 11 (95%C.I.: 1.4-94.5; p = 0.029). CONCLUSIONS: In T1D individuals, elevated pro-NT levels predict the development of adverse metabolic profile, which translates in higher CV risk profile at 10-year follow-up. Pro-NT represents a novel predictor/marker of CV risk factors in adults with T1D.

Effects of Manipulating Circulating Bile Acid Concentrations on Postprandial GLP-1 Secretion and Glucose Metabolism After Roux-en-Y Gastric Bypass.

Background: Altered bile acid (BA) turnover has been suggested to be involved in the improved glucose regulation after Roux-en-Y gastric bypass (RYGB), possibly via stimulation of GLP-1 secretion. We investigated the role of exogenous as well as endogenous BAs for GLP-1 secretion after RYGB by administering chenodeoxycholic acid (CDCA) and the BA sequestrant colesevelam (COL) both in the presence and the absence of a meal stimulus. Methods: Two single-blinded randomized cross-over studies were performed. In study 1, eight RYGB operated participants ingested 200 ml water with 1) CDCA 1.25 g or 2) CDCA 1.25 g + colesevelam 3.75 g on separate days. In study 2, twelve RYGB participants ingested on separate days a mixed meal with addition of 1) CDCA 1.25 g, 2) COL 3.75 g or 3) COL 3.75 g × 2, or 4) no additions. Results: In study 1, oral intake of CDCA increased circulating BAs, GLP-1, C-peptide, glucagon, and neurotensin. Addition of colesevelam reduced all responses. In study 2, addition of CDCA enhanced meal-induced increases in plasma GLP-1, glucagon and FGF-19 and lowered plasma glucose and C-peptide concentrations, while adding colesevelam lowered circulating BAs but did not affect meal-induced changes in plasma glucose or measured gastrointestinal hormones. Conclusion: In RYGB-operated persons, exogenous CDCA enhanced meal-stimulated GLP-1 and glucagon secretion but not insulin secretion, while the BA sequestrant colesevelam decreased CDCA-stimulated GLP-1 secretion but did not affect meal-stimulated GLP-1, C-peptide or glucagon secretion, or glucose tolerance. These findings suggest a limited role for endogenous bile acids in the acute regulation of postprandial gut hormone secretion or glucose metabolism after RYGB.

High serum neurotensin level in obese adolescents is not associated with metabolic parameters, hyperphagia or food preference.

OBJECTIVES: Obesity is often the result of a high-calorie and unbalanced diet for a long time and can sometimes be associated with hyperphagia and eating disorders. Neurotensin (NT) is an anorexigenic peptide, which is secreted from the central nervous system and intestines, and increases intestinal fat absorption. In the literature, conflicting results regarding serum NT level in obesity and the relation of NT with metabolic parameters were reported. Besides, there is no data regarding the relation of NT with eating disorders or food preference in obese individuals. We aimed to evaluate the relation of serum NT level with metabolic parameters, hyperphagia, binge eating disorder (BED) and food preference in obese adolescents. METHODS: The study included 65 obese adolescents and 65 healthy controls. Anthropometric measurements, biochemical analyzes and body fat analyzes were performed in all cases. Hyperphagia score, presence of BED and three-day food intake records were also evaluated. RESULTS: NT level was significantly higher in obese adolescents than in controls and it was not associated with metabolic parameters, hyperphagia or food preference. In the obese group, NT level was not significantly different according to the presence of BED. CONCLUSIONS: Serum NT level is high in obese adolescents; however, it is not associated with metabolic parameters, hyperphagia, BED or food preference.

Pro-Neurotensin/Neuromedin N and Risk of Incident Metabolic Syndrome and Diabetes Mellitus in the REGARDS Cohort.

CONTEXT: The peptide neurotensin is implicated in insulin resistance, diabetes mellitus (DM), and cardiovascular disease. OBJECTIVE: We studied the association of neurotensin's stable precursor, pro-neurotensin/neuromedin N (pro-NT/NMN) with incident metabolic syndrome (MetS) and DM. METHODS: We included 3772 participants from the REasons for Geographic and Racial Differences in Stroke (REGARDS) study who completed the baseline exam (2003-2007), the follow-up exam (2013-2016), and had pro-NT/NMN measured by immunoassay. Weighted logistic regression models were fitted to incident DM, incident MetS, and each MetS component, separately, incorporating demographics, metabolic risk factors, homeostasis model of insulin resistance (HOMA-IR), and diet scores. Incident MetS was defined by 3 or more harmonized criteria at follow-up in those with fewer than 3 at baseline. Incident DM was defined by use of hypoglycemic drugs/insulin, fasting glucose 126 mg/dL or greater, or random glucose 200 mg/dL or greater in those without these at baseline. RESULTS: Median (IQR) plasma pro-NT/NMN was 160 pmol/L (118-218 pmol/L). A total of 564 (of 2770 without baseline MetS) participants developed MetS, and 407 (of 3030 without baseline DM) developed DM. Per SD higher log-pro-NT/NMN, the demographic-adjusted odds ratio (OR) and 95% CI of incident MetS was 1.22 (1.11-1.35), 1.16 (1.00-1.35) for incident low high-density lipoprotein (HDL), and 1.25 (1.11-1.40) for incident dysglycemia. The association of pro-NT/NMN with MetS was attenuated in the model adding HOMA-IR (OR per SD log-pro-NT/NMN 1.14; 95% CI, 1.00-1.30). There was no association with incident DM (OR per SD log-pro-NT/NMN 1.06; 95% CI, 0.94-1.19). CONCLUSION: Pro-NT/NMN was associated with MetS and 2 components, dysglycemia and low HDL, likely explained by insulin resistance.

Circulating pro-neurotensin levels predict bodyweight gain and metabolic alterations in children.

BACKGROUND AND AIMS: Neurotensin (NT) is an intestinal peptide released after fat ingestion, which regulates appetite and facilitates lipid absorption. Elevated plasma levels of its stable precursor pro-neurotensin (pro-NT) are associated with type 2 diabetes, obesity and cardiovascular mortality in adult populations; no data on pro-NT and metabolic disease are available in children. Aim of the study was to evaluate plasma pro-NT in relation to the presence of obesity in children, and to test if high pro-NT associates with the development of metabolic impairment later in life. METHODS AND RESULTS: For this longitudinal retrospective study, we studied 151 overweight/obese children undergoing metabolic evaluations at University of Cagliari, Italy. Pro-NT was also assessed in 46 normal-weight, age-, sex-comparable normal-weight children, selected as a reference group. At the baseline, pro-NT was comparable between overweight/obese and normal-weight children and correlated positively with age (p < 0.001), triglycerides (p < 0.001) and inversely with HDL levels (p = 0.008). Plasma pro-NT associated with high triglycerides with OR = 5.9 (95%CI: 1.24-28.1; p = 0.026) after adjustment for multiple confounders. At the 6.5-year follow-up, high basal pro-NT associated with impaired ß-cell function to compensate for insulin-resistance (disposition index: r = -0.19, p = 0.035) and predicted bodyweight increase, as indicated by percentage change of standard deviation score BMI (median(95%CI) = +20.8(+4.9-+27.5)% in the highest tertile), independently from age, sex, triglycerides and insulin-resistance (standardized ß = 0.24; p = 0.036). CONCLUSIONS: Elevated pro-NT levels in children are significantly associated with weight gain later in life and may represent a marker of susceptibility to metabolic impairment in presence of obesity.

Pro-neurotensin/neuromedin N and risk of ischemic stroke: The REasons for Geographic And Racial Differences in Stroke (REGARDS) study.

The tridecapeptide neurotensin has been implicated in the pathogenesis of cardiometabolic disease. Its stable precursor, pro-neurotensin/neuromedin N (pro-NT/NMN), has been associated with composite cardiovascular outcomes including coronary heart disease (CHD) and stroke. The exclusive association of pro-NT/NMN with ischemic stroke has not been evaluated. We conducted a prospective case-cohort study in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. From 2003 to 2007, REGARDS enrolled 30,239 white or black adults aged ⩾ 45 years. Baseline fasting pro-NT/NMN was measured by immunoassay in the analytic sample including 448 incident ischemic stroke cases and 818 random cohort sample participants. A total of 464 ischemic strokes occurred. Risk of stroke was assessed with a Cox proportional-hazards model incorporating demographic covariates and a second adding stroke risk factors. Increased pro-NT/NMN was associated with ischemic stroke in the demographic model overall (hazard ratio (HR) per standard deviation (SD) pro-NT/NMN 1.16, 95% confidence interval (CI) 1.01-1.33) and in men (HR per SD pro-NT/NMN 1.25, 95% CI 1.04-1.50); HRs were attenuated in the risk factor model. Pre-existing diabetes mellitus and CHD were the largest confounders of ischemic stroke risk, each accounting for an estimated 19% of the association of pro-NT/NMN with ischemic stroke observed in the demographic model. There were no significant interactions of race or sex with pro-NT/NMN. Further research on associations of pro-NT/NMN with stroke risk factors such as diabetes mellitus is indicated.

High plasma levels of pro-NT are associated with increased colon cancer risk.

Emerging data supports a potential role of neurotensin (NT) in the development of obesity, obesity-associated comorbidities, and certain cancers. The association of NT with colon cancer risk has not been explicitly explored. We determined plasma levels of pro-NT, a stable NT precursor fragment, in 223 incident colon cancer patients and 223 age-, gender-, BMI-matched population controls participating in a population-based case-control study of colon cancer. On average, the cases have significantly higher levels of pro-NT than the controls (median = 205.6 pmol/L vs 183.1 pmol/L, respectively; P = 0.02). Multivariate logistic regression models, adjusted for age, gender, BMI, family history of colorectal cancer, smoking, diabetes mellitus, alcohol, and non-steroidal anti-inflammatory drugs use, show statistically significant risk associations: for continuous measure of pro-NT, the OR estimate was 1.30 (95% CI =1.03-1.64; P = 0.026) for each increment of 175 pmol/L; for dichotomized measure of pro-NT, the OR estimate was 1.75 (95% CI = 1.12-2.74; P = 0.025) for those in the top quartile comparing to the other participants. Our results support circulating levels of pro-NT as a novel risk biomarker for colon cancer.

C-terminal tails mimicking bioactive intermediates cause different plasma degradation patterns and kinetics in neuropeptides γ-MSH, α-MSH, and neurotensin.

Peptides are attractive drugs because of their specificity and minimal off-target effects. Short half-lives are within their major drawbacks, limiting actual use in clinics. The golden standard in therapeutic peptide development implies identification of a minimal core sequence, then modified to increase stability through several strategies, including the introduction of nonnatural amino acids, cyclization, and lipidation. Here, we investigated plasma degradations of hormone sequences all composed of a minimal active core peptide and a C-terminal extension. We first investigated pro-opimelanocortin (POMC) γ2/γ3-MSH hormone behavior and extended our analysis to POMC-derived α-melanocyte stimulating hormone/adrenocorticotropic hormone signaling neuropeptides and neurotensin. We demonstrated that in all the three cases analyzed in this study, few additional residues mimicking the natural sequence alter both peptide stability and the mechanism(s) of degradation of the minimal conserved functional pattern. Our results suggest that the impact of extensions on the bioactivity of a peptide drug has to be carefully evaluated throughout the optimization process.

Magnitude of rise in proneurotensin is related to amount of triglyceride appearance in blood after standardized oral intake of both saturated and unsaturated fat.

BACKGROUND: In rodents, neurotensin contributes to high fat diet induced obesity by facilitation of intestinal fat absorption. The effect of oral lipid load on plasma proneurotensin and relationship with plasma triglycerides in humans is unknown. AIM: To investigate the acute effects of an oral lipid load on proneurotensin and plasma triglycerides and their interrelationships in healthy individuals. SETTING/ METHODS: Twenty-two healthy subjects were given 150 mL of full milk cream (54 g fat) and 59 mL of pure olive oil (54 g fat) in the fasted state at two different occasions separated by at least 1 week in random order. Venous blood was drawn at fasted before 0 h (h) and at 1 h, 2 h and 4 h after ingestion. Post-ingested values of proneurotensin and plasma triglycerides were compared with fasting levels and post ingestion Area Under the Curve (AUC) of proneurotensin was correlated with that of plasma triglycerides. RESULTS: An immediate rise of plasma proneurotensin and plasma triglycerides were observed after ingestion of cream with maximum increase at 2 h for proneurotensin [mean (95% confidence interval)] of 22 (12-31) pmol/L (P < 0.001) and at 3 h for triglycerides of 0.60 (0.43-0.78) mmol/L (P < 0.001). Similarly, plasma proneurotensin and plasma triglycerides increased after ingestion of olive oil with maximum increase of proneurotensin at 3 h of 62 (46-78) pmol/L (P < 0.001) and plasma triglycerides at 3 h of 0.32 (0.18-0.45) mmol/L (P < 0.001). The post lipid load AUC for proneurotensin correlated significantly with the AUC for plasma triglycerides both after cream (r = 0.49, P = 0.021) and olive oil (r = 0.55, P = 0.008), respectively. CONCLUSION: Proneurotensin increases after an oral lipid load of both cream and olive oil and the rise of post-ingestion plasma triglycerides is significantly related to the rise of post-ingestion proneurotensin.

IL-38 inhibits microglial inflammatory mediators and is decreased in amygdala of children with autism spectrum disorder.

Autism spectrum disorder (ASD) is characterized by impaired social interactions and communication. The pathogenesis of ASD is not known, but it involves activation of microglia. We had shown that the peptide neurotensin (NT) is increased in the serum of children with ASD and stimulates cultured adult human microglia to secrete the proinflammatory molecules IL-1ß and CXCL8. This process is inhibited by the cytokine IL-37. Another cytokine, IL-38, has been reported to have antiinflammatory actions. In this report, we show that pretreatment of cultured adult human microglia with recombinant IL-38 (aa3-152, 1-100 ng/mL) inhibits (P < 0.0001) NT-stimulated (10 nM) secretion of IL-1ß (at 1 ng/mL) and CXCL8 (at 100 ng/mL). In fact, IL-38 (aa3-152, 1 ng/mL) is more potent than IL-37 (100 ng/mL). Here, we report that pretreatment with IL-38 (100 ng/mL) of embryonic microglia (HMC3), in which secretion of IL-1ß was undetectable, inhibits secretion of CXCL8 (P = 0.004). Gene expression of IL-38 and its receptor IL-36R are decreased (P = 0.001 and P = 0.04, respectively) in amygdala from patients with ASD (n = 8) compared to non-ASD controls (n = 8), obtained from the University of Maryland NeuroBioBank. IL-38 is increased (P = 0.03) in the serum of children with ASD. These findings indicate an important role for IL-38 in the inhibition of activation of human microglia, thus supporting its development as a treatment approach for ASD.

Pro-neurotensin depends on renal function and is related to all-cause mortality in chronic kidney disease.

BACKGROUND: Patients with chronic kidney disease (CKD) have a high risk of premature cardiovascular diseases (CVD) and show increased mortality. Pro-neurotensin (Pro-NT) was associated with metabolic diseases and predicted incident CVD and mortality. However, Pro-NT regulation in CKD and its potential role linking CKD and mortality have not been investigated, so far. METHODS: In a central lab, circulating Pro-NT was quantified in three independent cohorts comprising 4715 participants (cohort 1: patients with CKD; cohort 2: general population study; and cohort 3: non-diabetic population study). Urinary Pro-NT was assessed in part of the patients from cohort 1. In a 4th independent cohort, serum Pro-NT was further related to mortality in patients with advanced CKD. Tissue-specific Nts expression was further investigated in two mouse models of diabetic CKD and compared to non-diabetic control mice. RESULTS: Pro-NT significantly increased with deteriorating renal function (P < 0.001). In meta-analysis of cohorts 1-3, Pro-NT was significantly and independently associated with estimated glomerular filtration rate (P ≤ 0.002). Patients in the middle/high Pro-NT tertiles at baseline had a higher all-cause mortality compared to the low Pro-NT tertile (Hazard ratio: 2.11, P = 0.046). Mice with severe diabetic CKD did not show increased Nts mRNA expression in different tissues compared to control animals. CONCLUSIONS: Circulating Pro-NT is associated with impaired renal function in independent cohorts comprising 4715 subjects and is related to all-cause mortality in patients with end-stage kidney disease. Our human and rodent data are in accordance with the hypotheses that Pro-NT is eliminated by the kidneys and could potentially contribute to increased mortality observed in patients with CKD.

Identification of U-shaped curve relation between proneurotensin and risk of coronary artery disease (CAD) in patients with premature CAD.

BACKGROUND AND AIMS: Neurotensin (NT) is a gut hormone with broad effects on the cardiovascular system. Recent data suggested that circulating proneurotensin (pro-NT)-the stable precursor fragment of NT-could independently predict cardiovascular artery disease (CAD) development. However, serum pro-NT levels in patients with premature cardiovascular artery disease (PCAD) are still unknown. This study aims to determine serum pro-NT levels in patients with PCAD and investigate its relationship with PCAD risk. METHODS AND RESULTS: A total of 490 subjects, including 364 with PCAD and 126 without PCAD (NPCAD), and 182 controls were enrolled in the study. Data of baseline clinical parameters and biochemical variables were collected. Serum pro-NT levels were measured by ELISA. Serum pro-NT levels were higher in patients with PCAD than in controls (59.42 ± 66.66 vs. 38.07 ± 48.48 pg/mL, P < 0.05), especially in patients with BMI<25 kg/m2. Serum pro-NT levels were independently related to PCAD (ß = 0.349, P < 0.001), and the association revealed a U-shaped curve characteristic between pro-NT tertiles and CAD risk in patients with premature CAD and controls. Subjects with low and high tertiles of pro-NT levels had 1.79-fold and 2.23-fold higher risks of PCAD, respectively, than subjects with median pro-NT levels (P < 0.05). After adjusting for age, gender, and BMI in Model 1 and other confounders in Model 2 and Model 3, the U-shaped relationship remained significant. CONCLUSION: Serum pro-NT levels were significantly increased in patients with PCAD. The association between pro-NT levels and PCAD risk presents a U-shaped curve characteristic, which demonstrated that subjects with lower and higher pro-NT levels both were more likely to have PCAD.

Decreased neurotensin levels as a biomarker in resistant hypertension.

Objective: Although neurotensin is found throughout the body including cardiovascular structures, the correlation of plasma neurotensin levels with resistant hypertension (RH) has never been examined. Therefore, we aimed to compare plasma neurotensin concentration, between patients with RH and those with controlled hypertension (CH).Methods: Forty-one patients with RH and 45 patients with CH who had undergone outpatient ambulatory blood pressure measurements were prospectively recruited. RH was defined as uncontrolled blood pressure despite using three antihypertensive agents including a diuretic or need of four or more drugs to control blood pressure. The demographic properties, medications, laboratory parameters including neurotensin levels, and echocardiographic parameters were recorded.Results: There was no significant difference among groups in terms of age, sex, smoking or body mass index. Office and ambulatory blood pressures and mean number of antihypertensive drugs used were significantly higher in patients with RH compared to patients with CH. Plasma neurotensin levels were significantly lower in patients with RH (median: 0.380 ng/ml; interquartile range: 0.292-0.471) than in the patients with controlled blood pressure (median: 0.638 ng/ml; interquartile range: 0.483-0.783). Multivariate and receiver-operating characteristics curve analyses showed that neurotensin is an independent predictor for RH and the optimal cut-off value of neurotensin for RH was lower than 0.509 ng/ml, with a sensitivity of 85.4% and a specificity of 73.3% (area under the curve = 0.793, 95% CI: 0.691-0.894, p < .001)Conclusion: This study is the first to show a correlation between lower neurotensin levels and RH.