Corrigendum: Newborn screening for X-linked adrenoleukodystrophy in Italy: diagnostic algorithm and disease monitoring

[This corrects the article DOI: 10.3389/fneur.2022.1072256.].

Newborn screening for X-linked adrenoleukodystrophy in Italy: Diagnostic algorithm and disease monitoring

Introduction

X-linked adrenoleukodystrophy (X-ALD) is the most common inherited peroxisomal disorder caused by variants in the ABCD1 gene. The main phenotypes observed in men with X-ALD are primary adrenal insufficiency, adrenomyeloneuropathy, and cerebral ALD (cALD). Cerebral ALD consists of a demyelinating progressive cerebral white matter (WM) disease associated with rapid clinical decline and is fatal if left untreated. Hematopoietic stem cell transplantation is the standard treatment for cALD as it stabilizes WM degeneration when performed early in the disease. For this reason, early diagnosis is crucial, and several countries have already implemented their newborn screening programs (NBS) with the assessment of C26:0-lysophosphatidylcholine (C26:0-LPC) values as screening for X-ALD.

Methods

In June 2021, an Italian group in Lombardy launched a pilot study for the implementation of X-ALD in the Italian NBS program. A three-tiered approach was adopted, and it involved quantifying the values of C26:0-LPC and other metabolites in dried blood spots with FIA-MS/MS first, followed by the more specific ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) technique and, finally, the genetic confirmation via focused NGS.

Discussion

Genetically confirmed patients are set to undergo a follow-up protocol and are periodically evaluated to promptly start a specific treatment if and when the first signs of brain damage appear, as suggested by international guidelines. A specific disease monitoring protocol has been created based on literature data and personal direct experience.

Conclusion

The primary aim of this study was to develop a model able to improve the early diagnosis and subsequent follow-up and timely treatment of X-ALD.

Ethics

The study was approved by the local ethics committee. The research was conducted in the absence of any commercial or financial relationship that could be construed as a potential conflict of interest.

Menkes disease complicated by concurrent ACY1 deficiency: A case report

Introduction: Menkes disease is an X-linked recessive condition caused by mutations in the ATP7A gene, which leads to severe copper deficiency. Aminoacylase-1 deficiency is a rare inborn error of metabolism caused by homozygous or compound heterozygous variant in the ACY1 gene, characterized by increased urinary excretion of specific N-acetyl amino acids. Case presentation: We report an infant with neurological findings such as seizures, neurodevelopmental delay and hypotonia. Metabolic screening showed low serum copper and ceruloplasmin, and increased urinary excretion of several N-acetylated amino acids. Whole-exome sequencing analysis (WES) revealed the novel de novo variant c.3642_3649dup (p.Ala1217Aspfs*2) in the ATP7A gene, leading to a diagnosis of Menkes disease, and the simultaneous presence of the homozygous ACY1 variant c.1057C>T (p.Arg353Cys) causative of Aminoacylase-1 deficiency. Conclusion: Our patient had two rare conditions with different treatment courses but overlapping clinical features. The identified novel ATP7A mutation associated with Menkes disease expands the ATP7A gene spectrum.

Does school reopening affect SARS-CoV-2 seroprevalence among school-age children in Milan?

The benefits of schools' closure, used as a containment strategy by many European countries, must be carefully considered against the adverse effects of child wellbeing. In this study, we assessed SARS-CoV-2 seroprevalence, which better estimates the real extent of the infection unraveling asymptomatic cases, among schoolchildren aged 3 to 18 in Milan, using dried blood spot, a safe and extremely viable methods for children, and then compared it between September 2020 and January 2021. Secondly, we evaluated the seroconversion rate and compared it between students attending schools in presence and those switched to distance-learning, using a logistic regression model, both as univariate and multivariate, adjusting for age and biological-sex. Among 1109 pupils, we found a seroprevalence of 2.8% in September before school reopening, while in January 2021, the seropositive rate was 12.5%, reflecting the general growth rate of infections during the second pandemic wave. The overall seroconversion rate was 10%, with no differences based on biological-sex and age groups; we observed no seroreversion. When considered age groups, the seroconversion rate was 10.5% (95%Confidence Interval, 2.9-24.8) among children attending preschools, 10.6% (95%Confidence Interval, 8.2-13.4) for primary schools, 9.9% (95%Confidence Interval, 6.8-13.8) for secondary schools, and 7.8% (95%Confidence Interval, 4-13.2) among high-school students. Interestingly, no differences in seroconversion rate were found between students who attended school compared to those who started remote learning in the first days of November. Furthermore, most patients (61%) reported that the contact occurred within the household. We reported a low seroconversion rate among school children in Milan, with no differences between those who attended from September 2020 to January 2021 compared to those who switched to remote learning in the first days of November. Our data suggest that schools do not amplify SARS-CoV-2 transmission, but rather reflect the level of the transmission in the community.

Reduction of the emergency activity, during the Covid 19 Italian lockdown, what's the lesson to learn?

The COVID 19 pandemic was declared on the 9^th of March 2020. The health crisis affected the whole world with a very high and unexpected number of infected people. The situation forced the declaration of lockdown and a worldwide health system reorganization. Surprisingly, the social distancing laws caused a reduction of urgent hospital activities not COVID 19 related. The aim of this manuscript is to analyze the reasons why fewer emergencies were described during the 2020 Italian lockdown. The Data reporting urgent Emergency Room (ER) activity, during the first three weeks of the Italian lockdown (Group 1), were analyzed and compared with the same period in 2019 (Group 2). During the study period in 2020, there was a 46,5% reduction in ER activity compared to that in 2019. Nevertheless, the hospitalization rate was higher in the 2020 then in 2019 (p<0.05). The present data showed that almost half of the basic ER activity araised from mild health problems that could be followed by territorial health services. The strengthening of territorial medical services would allow hospitals to handle critical situations more easily and to focus activity by reducing the waiting list.

Phenotypic spectrum of short-chain enoyl-Coa hydratase-1 (ECHS1) deficiency

INTRODUCTION

ECHS1 encodes for short-chain enoyl-CoA hydratase, a key component in b-oxidation. This enzyme is also involved in the isoleucine and valine catabolic pathways. The literature contains reports of scattered cases of ECHS1 mutation, which show a wide clinical spectrum of presentation. Despite that the clinical spectrum of the disease has not been defined so far due to the absence of previous systematic reviews and descriptions of large series of patients.

METHODS

We performed a systematic literature review of so far reported ECHS1 mutated patients and we reported two additional cases. We pointed out clinical and neuroradiological features of all patients.

RESULTS

45 patients were included in the analysis. Based on clinical and neuroradiological feature we were able to distinguish four main phenotypes of ECHS1deficiency: a severe neonatal presentation with a rapid and fatal course and significant white matter abnormalities; a severe infantile variant with slower neurological deterioration, developmental delay, pyramidal and extrapyramidal signs, optic atrophy, feeding difficulties, and degeneration of the deep gray nuclei; a slowly progressive infantile form, qualitatively similar to the previous phenotype, but less severe with mainly basal ganglia involvement; and a final phenotype, present in only few cases, characterized by paroxysmal exercise-induced dystonic attacks, normal neurological examination between these episodes, and isolated pallidal degeneration on MRI.

INTERPRETATION

ECHS1 mutations cause metabolic encephalopathy with a wide range of clinical presentations that can be grouped into four main phenotypes, each with a distinct profile in terms of severity on clinical presentation, disease course and MRI involvement.

Laparoscopic transhiatal suture and gastric valve as a safe and feasible treatment for Boerhaave's syndrome: an Italian single center case series study

Background

Boerhaave’s syndrome (BS) is a rare life-threating condition with poor prognosis. Unfortunately, due to its very low incidence, no clear evidences or definitive guidelines are currently available: in detail, surgical strategy is still a matter of debate. Most of the case series reports thoracic approach as the most widely used; conversely, transhiatal abdominal management is just described in sporadic case reports. In our center, the laparoscopic approach has been adopted for years: in the present study, we aim to show his feasibility by reporting the outcomes of the largest clinical series available to date.

Methods

Clinical records of patients admitted for BS to the General and Upper GI Surgery Division of Verona from February 2014 to December 2019 were retrospectively collected. Clinico-pathological characteristics, preoperative workup, surgical management, and outcomes were analyzed.

Results

Seven patients were admitted; epigastric/thoracic pain and vomiting were the most frequent symptoms at diagnosis. Laboratory findings were not specific; conversely, radiological imaging always revealed abnormal findings: particularly, CT had excellent sensitivity in detecting signs of esophageal perforation. All but one case had diagnostic workup and received surgery within 24 h. Every patient had laparoscopic transhiatal direct suture and gastric valve; 2 patients (28.6%) also needed a thoracoscopic toilette. Postoperative complications occurred in 4 patients (57%), but in only two of them (29%), the complication was severe according to Clavien-Dindo classification (both received thoracentesis or thoracic drainage for pleural effusion). Of note, no cases of postoperative esophageal leak were recorded. Postoperative mortality was 14% due to one patient who died for cardiovascular complications. Most of the patients (71.4%) were admitted to ICU after surgery (average length, 8.8 days); mean hospital stay was 14.7 days. No patients had readmissions.

Conclusions

To our knowledge, this is the largest case series reporting laparoscopic management of BS. We show that laparoscopy is a safe and feasible approach associated with a shorter length of hospital stay when compared with clinical series in which thoracic approach had been chosen. Of note, laparoscopic management would be easily adopted by surgical centers treating benign gastro-esophageal junction entailing a proper management more widely.

FRI0056 LUNG COMPROMISE SCREENING IN PATIENTS WITH EARLY RA. A MULTICENTRIC CROSS SECTIONAL STUDY

Background:

Rheumatoid arthritis (RA) affects 0.4-1.3% of general population (1). It can affect lungs in different ways, with interstitial lung disease (ILD) as the most severe. Clinically evident ILD has been reported in 10-42% of patients, with a great impact in prognosis (2).

Objectives:

Toidentify the prevalence of lung involvement in early rheumatoid arthritis patients (ERA) without previous known lung disease and describe the association between high resolution computed tomography (HRCT), lung functional tests (LFT) and clinical findings.

Methods:

Cross sectional multicentric study. We included ERA patients (1 year or less since diagnose) consecutively. Patients with previous RA related lung disease or biologic/targeted synthetic Dmard treatment were excluded. HRCT, immunological tests (rheumatoid factor, anti-CCP, ANA), LFT and clinical evaluation were performed.

Results:

We included 74 patients, 63 (85,1%) woman, mean (SD) of 47 (17,7) years. Thirty-seven patients (50%) were current or former smokers. Abnormal findings in HRCT were found in 62 patients (88,6%): ILD in 6 (8,6%), airway involvement in 40 (70%) and emphysema in 7 (10%). Ten patients (13,5%) had abnormal auscultation (2 sibilances, 2 roncus, and 6 crackles). Six patients (8,1%) had digital clubbing. Regarding immunological tests, 54/61 (88,5%) patients were positive for Anti CCP, and 53/61 (86,9%) were positive for FR. We compared features of patients with findings related to RA in HRCT (interstitial and/or airway) with those without them. We found no differences in the mean (SD) of DAS-28 [4,74 (1,38) vs 4,32 (1,39); p= 0,27]. The prevalence of anti- CCP was not higher in patients with abnormal HRCT [38/44 (86,3%) vs 16/17 (94,1%); p=0,39]. Patients with abnormal HRCT were older [median (IQR) 50,5 years (44,5-59,5) vs 43 years (32-51); p=0,008) and showed higher VSG values [mean (SD) 39,09 (24,03) vs 27,38 (17,6); p= 0,043]. Abnormal physical examination or dyspnea (class 2 mMRC or higher) was significantly associated with HRCT abnormalities [26 (50%) vs 3 (13,6%); p=0.003) and the presence of ILD on HRCT was significantly associated with crackles on the auscultation [4/68(6,25%) vs 2/6 (33,33%); p 0,023].

Conclusion:

This study shows a high prevalence of lung involvement in ERA patients of less 1 year from diagnosis. Also, we showed a significant association between HRCT and physical examination findings. This data highlights the importance of the clinical examination in Rheumatoid Arthritis patients. More studies with bigger samples and longitudinal follow up are needed to confirm and complete our results.

References:

[1]Rooney BK, Silman AJ. Epidemiology of the rheumatic diseases. Curr Opin Rheumatol [Internet]. 1999 Mar [cited 2016 Jul 19];11(2):91–7. Available from:http://www.ncbi.nlm.nih.gov/pubmed/10319210.

[2]Antin-Ozerkis D, Evans J, Rubinowitz A, Homer RJ, Matthay RA. Pulmonary Manifestations of Rheumatoid Arthritis. Clin Chest Med [Internet]. 2010;31(3):451–78. Available from:http://dx.doi.org/10.1016/j.ccm.2010.04.003.

Disclosure of Interests:

None declared

Diagnosing congenital Cytomegalovirus infection: don't get rid of dried blood spots

Background

Congenital Cytomegalovirus (cCMV) is a serious global public health issue that can cause irreversible fetal and neonatal congenital defects in symptomatic or asymptomatic newborns at birth. In absence of universal cCMV screening, the retrospective diagnosis of cCMV infection in children is only possible by examining Dried Blood Spot (DBS) samples routinely collected at birth and stored for different time spans depending on the newborn screening regulations in force in different countries. In this article, we summarize the arguments in favor of long-term DBS sample storage for detecting cCMV infection.

Main text

CMV infection is the most common cause of congenital infection resulting in severe defects and anomalies that can be apparent at birth or develop in early childhood. Sensorineural hearing loss is the most frequent consequence of cCMV infection and may have a late onset and progress in the first years of life. The virological diagnosis of cCMV is essential for clinical research and public health practices. In fact, in order to assess the natural history of CMV infection and distinguish between congenital or acquired infection, children should be diagnosed early by analyzing biological samples collected in the first weeks of life (3 weeks by using viral culture and 2 weeks by molecular assays), which, unfortunately, are not always available for asymptomatic or mildly symptomatic children. It now seems possible to overcome this problem since the CMV-DNA present in the blood of congenitally infected newborns can be easily retrieved from the DBS samples on the Guthrie cards routinely collected and stored within 3 days from birth in the neonatal screening program for genetic and congenital diseases. Early collection and long-term storage are inexpensive methods for long-term bio-banking and are the key points of DBS testing for the detection of cCMV.

Conclusion

DBS sampling is a reliable and inexpensive method for long-term bio-banking, which enables to diagnose known infectious diseases - including cCMV - as well as diseases not jet recognized, therefore their storage sites and long-term storage conditions and durations should be the subject of political decision-making.

Enhanced recovery protocol in esophagectomy, is it really worth it? A cost analysis related to team experience and protocol compliance

Application of enhanced recovery protocols (ERP) in esophageal surgery seems to lead an advantage in terms of length of hospital staying and outcomes, but only few data exist on its cost effectiveness. Previous literature analyzed pre- and post-ERP groups, finding a cost reduction with the introduction of the pathway. We aimed to study the influence on costs of accumulating experience and compliance in an ERP group. Seventy-one patients have been treated at our institution from January 2014 to June 2017 with our ERP for Ivor-Lewis esophagectomy. Direct costs were divided into subcategories and were analyzed as a function of calendar year and compliance. Factor affecting costs were searched. Univariable analysis highlighted a significant reduction in costs over time. Increase in compliance led to a progressive cost reduction for each ERP item completed (€14 852-€11 045). While age was not found to significantly influence the cost (p = 0.341), complications seemed to nullify the effect of experience: the median was €11 507 in uncomplicated patients, and increased to €13 791 in Clavien-Dindo 3-4 (CD3-4) patients. Compliance and CD3-4 remained significant also in multivariable analysis, accomplished by quantile regression, while year of surgery lost its significance. Our results evidence how accumulating experience in ERP led to a cost reduction over time, which was mainly mediated by an increase in compliance. Indeed, compliance was the main factor in reducing ERP cost while CD3-4 complications were the most important factor in cost increasing, nullifying the benefit of compliance.

A New Targeted CFTR Mutation Panel Based on Next-Generation Sequencing Technology

Searching for mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR) is a key step in the diagnosis of and neonatal and carrier screening for cystic fibrosis (CF), and it has implications for prognosis and personalized therapy. The large number of mutations and genetic and phenotypic variability make this search a complex task. Herein, we developed, validated, and tested a laboratory assay for an extended search for mutations in CFTR using a next-generation sequencing-based method, with a panel of 188 CFTR mutations customized for the Italian population. Overall, 1426 dried blood spots from neonatal screening, 402 genomic DNA samples from various origins, and 1138 genomic DNA samples from patients with CF were analyzed. The assay showed excellent analytical and diagnostic operative characteristics. We identified and experimentally validated 159 (of 188) CFTR mutations. The assay achieved detection rates of 95.0% and 95.6% in two large-scale case series of CF patients from central and northern Italy, respectively. These detection rates are among the highest reported so far with a genetic test for CF based on a mutation panel. This assay appears to be well suited for diagnostics, neonatal and carrier screening, and assisted reproduction, and it represents a considerable advantage in CF genetic counseling.

Erectile dysfunction in heart failure patients: a critical reappraisal

Heart failure (HF) is a complex clinical syndrome with a constantly increasing incidence and prevalence in western countries. Total absence of sexual activity is registered in 30% of HF patients. Moreover, HF-induced reduction in exercise tolerance, side effects of HF medications and the coexistence of shared risk factors between HF and sexual dysfunction may further aggravate the sexual health of HF patients. The purpose of this review is to examine the pathophysiological mechanisms behind the association of erectile dysfunction (ED) and HF, the potential therapeutic approaches and the eventual indications for sexual activity in HF patients. Medline and Cochrane Library search was performed from January 1970 through October 2012 to retrieve relevant papers outlining the association between ED and HF. Many evidences have outlined a tight association between ED and HF pathophysiological standpoint. Shared risk factors, common pathogenic traits and epidemiologic association represent some of the links between these conditions. Erectile dysfunction has been recognized as an earlier predictor of cardiovascular events; moreover, HF itself may cause and/or worsen ED because of its particular feature and co-morbidities. Furthermore, some cardiovascular drugs may contribute to impaired erectile function. In stable patients with stable HF, sexual activity is generally not contraindicated but it should be encouraged, as a form of moderate-intensity physical exertion. An effective treatment of ED in HF patients should be founded on the correction of reversible risk factors, on the choice of cardiovascular drugs with the lowest effect upon patient's erectile function, and on the use of phosphodiesterase-5-inhibitors. Physicians should be aware of the close relation between HF and ED and of the related clinical and therapeutic implications, in order to improve patients quality of life and clinical outcome.

A novel missense mutation in the signal peptide of the human POMC gene: a possible additional link between early-onset type 2 diabetes and obesity

Rare mutations in several genes have a critical role in the control of homeostatic mechanisms such as food-intake, energy balance and glucose metabolism. In this study, we performed a mutational screening in a 58-year-old woman presenting early-onset type 2 diabetes and central obesity. The entire coding regions of MC4R, MC3R, HNF1A, GCK and POMC (pro-opiomelanocortin) genes were analyzed by direct sequencing. A new missense mutation was identified within the POMC gene signal peptide sequence, resulting in a heterozygous substitution of an arginine for a glycine at codon 15 (p.A15G) that was excluded in 300 healthy normal weight controls. The mutation segregated in the family and was associated with overweight, type 2 diabetes, hypertension and coronary heart disease in the carriers. Functional studies demonstrated that POMC protein was not detectable in β-TC3 cells transfected with A15G-POMC vector as well as in their culture media, despite POMC mRNA levels were comparable for amount and stability to those of wild-type-transfected cells. In silico RNA folding prediction indicated that the mutation gives rise to a different RNA secondary structure, suggesting that it might affect translation and protein synthesis. To the best of our knowledge, this is the first report addressing the functional consequences of a mutation in the signal peptide of POMC. These findings further support the hypothesis that POMC-derived peptides might have a role in the control of peripheral glucose metabolism and suggest that disruption of central POMC secretion might represent an additional link between type 2 diabetes and obesity.

Mutant Huntingtin induces activation of the Bcl-2/adenovirus E1B 19-kDa interacting protein (BNip3)

Huntington's disease (HD) is a neurodegenerative disorder characterized by progressive neuronal death in the basal ganglia and cortex. Although increasing evidence supports a pivotal role of mitochondrial dysfunction in the death of patients' neurons, the molecular bases for mitochondrial impairment have not been elucidated. We provide the first evidence of an abnormal activation of the Bcl-2/adenovirus E1B 19-kDa interacting protein 3 (BNip3) in cells expressing mutant Huntingtin. In this study, we show an abnormal accumulation and dimerization of BNip3 in the mitochondria extracted from human HD muscle cells, HD model cell cultures and brain tissues from HD model mice. Importantly, we have shown that blocking BNip3 expression and dimerization restores normal mitochondrial potential in human HD muscle cells. Our data shed light on the molecular mechanisms underlying mitochondrial dysfunction in HD and point to BNip3 as a new potential target for neuroprotective therapy in HD.

In vitro and in vivo effects of metformin on human adipose tissue adiponectin

OBJECTIVE

The effects of metformin on adiponectin production are controversial and have never been investigated in human adipose tissue. We analysed whether metformin modulates, in vitro and in vivo, gene expression, protein content, and secretion of adiponectin.

METHODS

For the in vitro study, subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) samples from 5 non-diabetic obese patients were collected. For the in vivo investigation, 22 obese patients were randomly assigned to metformin+lifestyle (ML) or placebo+lifestyle (PL) intervention. SAT specimens and blood samples were collected before and after the intervention in both groups.

RESULTS

In in vitro experiments, treatment with metformin increased the expression and secretion of adiponectin in SAT, but not in VAT explants. In the in vivo study, a significant increase in adiponectin and a decreased expression of a macrophage activation marker (CD68) were observed only in SAT of the ML group.

CONCLUSION

These results demonstrate that metformin is able to up-regulate adiponectin gene expression, both in vivo and in vitro, and to stimulate adiponectin protein secretion from human SAT in vitro. It could be hypothesised that metformin-induced adiponectin increase within adipose tissue may have an unexpected role in the reduction of local inflammation.

Assay of hydroxyl radicals generated by focused ultrasound

Water sonolysis leads to the formation of hydroxyl radicals (OH*). Various techniques are used to detect the OH* production and thus to assess the level of ultrasound-mediated cavitation generated in vitro. In this study, we used terephthalic acid (TA) as an OH* trap. This method is based on the fluorescent properties of hydroxyterephthalic acid (HTA) formed by the reaction of TA with OH* and used as an indicator of the degree of inertial cavitation caused. The experimental system is comprised mainly of a focused piezoelectric ultrasound transmitter and a measurement cell containing 1X PBS/TA diluted solution. In the first part, we aimed to characterize the most appropriate experimental conditions (TA dosimeter solution, irradiation time) in order to optimize the resulting HTA fluorescence values. Then, we could determine that the HTA production increased with the level of the cavitation phenomenon caused by the acoustic power from which OH* production may be estimated.

Protein kinase A regulatory subunits in human adipose tissue: decreased R2B expression and activity in adipocytes from obese subjects

OBJECTIVE

In human adipocytes, the cAMP-dependent pathway mediates signals originating from beta-adrenergic activation, thus playing a key role in the regulation of important metabolic processes, i.e., lipolysis and thermogenesis. Cyclic AMP effects are mainly mediated by protein kinase A (PKA), whose R2B regulatory isoform is the most expressed in mouse adipose tissue, where it protects against diet-induced obesity and fatty liver development. The aim of the study was to investigate possible differences in R2B expression, PKA activity, and lipolysis in adipose tissues from obese and nonobese subjects.

RESEARCH DESIGN AND METHODS

The expression of the different PKA regulatory subunits was evaluated by immunohistochemistry, Western blot, and real-time PCR in subcutaneous and visceral adipose tissue samples from 20 nonobese and 67 obese patients. PKA activity and glycerol release were evaluated in total protein extract and adipocytes isolated from fresh tissue samples, respectively.

RESULTS

Expression techniques showed that R2B was the most abundant regulatory protein, both at mRNA and protein level. Interestingly, R2B mRNA levels were significantly lower in both subcutaneous and visceral adipose tissues from obese than nonobese patients and negatively correlated with BMI, waist circumference, insulin levels, and homeostasis model assessment of insulin resistance. Moreover, both basal and stimulated PKA activity and glycerol release were significantly lower in visceral adipose tissue from obese patients then nonobese subjects.

CONCLUSIONS

Our results first indicate that, in human adipose tissue, there are important BMI-related differences in R2B expression and PKA activation, which might be included among the multiple determinants involved in the different lipolytic response to beta-adrenergic activation in obesity.

RET genotypes in sporadic medullary thyroid cancer: studies in a large Italian series

BACKGROUND

Highly discrepant data about the different distribution of RET germline single nucleotide polymorphisms (SNPs) among patients with sporadic medullary thyroid cancer (sMTC) and controls are available.

DESIGN AND PATIENTS

In the present case-control study, a wide panel of seven RET SNPs has been tested in the largest sMTC series and in a matched control group.

RESULTS

None of the investigated polymorphisms show a significantly different distribution in patients with sMTC when compared to controls. Twenty haplotypes and 57 genotypes were generated, and their association with the disease and with the clinical features were statistically evaluated. Interestingly, 14 genotypes were found to be unique to sMTC patients and 25 to controls. Two haplotypes and three genotypes, all including the intronic variants IVS1-126 and IVS14-24, were significantly associated with sMTC patients and with a higher tumour aggression. The functional activity of the only nonsynonymous RET variant (c.2071C > A, G691S) was tested for the first time. Interestingly, Western blot analyses showed that the fraction of Ret9-G691S protein located at the plasma membrane level was overrepresented when compared to Ret9-WT, suggesting facilitated targeting at the cell membrane for this variant. However, no transforming activity was shown in a focus formation assay on cells carrying the Ret9-G691S, against a possible oncogenic role of G691S variant.

CONCLUSIONS

RET genotypes including two intronic RET variants were associated with the risk of developing sMTC and to more aggressive behaviour. Further studies are warranted to elucidate whether these RET genotypes are in linkage disequilibrium with another susceptibility gene or whether these variants could play a role in the genesis of sMTC per se.

Type 2 diabetes and metabolic syndrome are associated with increased expression of 11beta-hydroxysteroid dehydrogenase 1 in obese subjects

OBJECTIVE

The role of glucocorticoids production in adipose tissue in the development of metabolic disorders in humans has not been fully characterized. We investigated whether in obese subjects, 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) expression in subcutaneous (SAT) and visceral (VAT) adipose tissue is associated with the occurrence of metabolic disorders and the expression of adiponectin and tumor necrosis factor alpha (TNFalpha) and two glucocorticoid-regulated adipokines able to influence the metabolic control.

DESIGN AND SUBJECTS

Sixty-two obese patients were enrolled in the study. SAT and VAT samples were obtained from 13 patients undergoing bariatric surgery (body mass index (BMI) 39.1+/-5.3 kg/m(2)). SAT samples were obtained from 49 patients who underwent periumbilical biopsy (BMI 36.9+/-5.1 kg/m(2)).

MEASUREMENTS

Oral glucose tolerance tests in subjects without known diabetes. Circulating glucose, lipid, insulin, adiponectin, TNFalpha and urinary-free cortisol levels. Real-time PCR to quantify mRNA levels of 11beta-HSD1, hexose-6-phosphate dehydrogenase (H6PDH), adiponectin and TNFalpha. Western blot analysis to evaluate 11beta-HSD1 protein expression.

RESULTS

In the majority of the obese subjects, VAT expresses more 11beta-HSD1 than SAT. VAT 11beta-HSD1 expression was not associated with metabolic disorders. SAT 11beta-HSD1 mRNA levels were higher in subjects with than in those without metabolic syndrome (P<0.05) and in patients with type 2 diabetes compared to patients with impaired or normal glucose tolerance (P<0.0001). SAT 11beta-HSD1 expression was independently related to fasting glucose (P<0.0001) and urinary-free cortisol levels (P<0.01), and increased expression of 11beta-HSD1 was associated with increased adiponectin and TNFalpha expression and decreased serum adiponectin levels (all P's <0.05).

CONCLUSIONS

In obese subjects, increased 11beta-HSD1 expression in SAT, but not in VAT, is associated with the worsening of metabolic conditions. We hypothesize that higher glucocorticoid production in adipose tissue would favor the development of metabolic disorders through a decrease in adiponectin release.

Adiponectin receptors gene expression in lymphocytes of obese and anorexic patients

AIM

Two adiponectin receptors (ADIPORs), ADIPOR1 and ADIPOR2, are widely expressed in tissues. Whether changes in the expression of ADIPORs are associated with obesity and insulin resistance in humans is still unclear. The aim of this study was to explore whether lymphocyte ADIPOR1 and ADIPOR2 mRNA expression is associated with obesity, insulin resistance, first-phase insulin secretion and serum adiponectin levels.

METHODS

Using reverse transcription-polymerase chain reaction, we measured ADIPOR1 and ADIPOR2 mRNA levels in the lymphocytes of 59 obese patients, of whom 39 had normal glucose tolerance, 8 had impaired glucose tolerance or impaired fasting glucose, and 12 had type 2 diabetes, and of 21 women with restrictive anorexia nervosa.

RESULTS

In all subjects, ADIPOR1 expression was 2.2-fold higher than that of ADIPOR2 (p < 0.0001). The mRNA expression level of both receptors correlated with each other (p < 0.0001). After adjustment for age and sex, lymphocyte ADIPORs mRNA expression (ADIPOR1, p < 0.005; ADIPOR2, p < 0.05) and serum adiponectin (p < 0.0001) were significantly lower in obese patients than in anorexic subjects. In a multivariate analysis with ADIPOR1 as the dependent variable and body mass index (BMI), blood pressure and adiponectin as the independent variables, only serum adiponectin remained positively and independently correlated with ADIPOR1 (p < 0.05). Adiponectin was independently and negatively related to BMI and sex.

CONCLUSIONS

We have demonstrated in this study that lymphocytes express ADIPORs and that, similar to serum adiponectin, ADIPORs expression is markedly reduced in obese subjects. ADIPORs expression is not independently related to BMI, insulin resistance and beta-cell function.

SH2B1beta adaptor is a key enhancer of RET tyrosine kinase signaling

The RET gene encodes two main isoforms of a receptor tyrosine kinase (RTK) implicated in various human diseases. Activating germ-line point mutations are responsible for multiple endocrine neoplasia type 2-associated medullary thyroid carcinomas, inactivating germ-line mutations for Hirschsprung's disease, while somatic rearrangements (RET/PTCs) are specific to papillary thyroid carcinomas. SH2B1beta, a member of the SH2B adaptors family, and binding partner for several RTKs, has been recently described to interact with proto-RET. Here, we show that both RET isoforms and its oncogenic derivatives bind to SH2B1beta through the SRC homology 2 (SH2) domain and a kinase activity-dependent mechanism. As a result, RET phosphorylates SH2B1beta, which in turn enhances its autophosphorylation, kinase activity, and downstream signaling. RET tyrosine residues 905 and 981 are important determinants for functional binding of the adaptor, as removal of both autophosphorylation sites displaces its recruitment. Binding of SH2B1beta appears to protect RET from dephosphorylation by protein tyrosine phosphatases, and might represent a likely mechanism contributing to its upregulation. Thus, overexpression of SH2B1beta, by enhancing phosphorylation/activation of RET transducers, potentiates the cellular differentiation and the neoplastic transformation thereby induced, and counteracts the action of RET inhibitors. Overall, our results identify SH2B1beta as a key enhancer of RET physiologic and pathologic activities.

An in-frame complex germline mutation in the juxtamembrane intracellular domain causing RET activation in familial medullary thyroid carcinoma

Activating mutations of the RET proto-oncogene are associated with inherited syndromes, multiple endocrine neoplasia (MEN2A/2B) and with familial and sporadic medullary thyroid cancer (MTC). Single base pair missense mutations in the extracellular Cys-rich domain are responsible for most MEN2A and familial MTC (FMTC) cases. Rarely, somatic deletions and germline duplications have been described in sporadic MTC and in FMTC. We report the detection and functional studies of a deletion/insertion in exon 11 (c.2646delGinsTTCT) associated with FMTC. This in-frame complex rearrangement leads to an Asn to Lys change (Lys666Asn) and to a Ser insertion. The mutation was found in the proband, who was diagnosed with metastatic MTC at 41 years, and in her son, who presented diffuse C-cells hyperplasia at 4 years of age. The mutation displayed a transforming activity stronger than Ret wild type (Ret-WT) at the focus formation assay and functional analyses after transient and stable transfection revealed an increased autophosphorylation, indicating the constitutive activation of the receptor. The transforming activity may be favoured by an increased stabilization of the fully mature form of the mutant receptor. Dimerization assay demonstrated that the activation mechanism of the complex mutation is not mediated by stable dimer formation. Computational analysis predicted nonconservative alterations in the mutant protein consistent with a possible modification of the conformation of the receptor. In conclusion, the first molecular studies on a complex germline RET mutation lying in the juxtamembrane region of the receptor are reported. Functional analyses showed that alterations at this level too can lead to a ligand independent Ret activation.

Increased apoptosis, Huntingtin inclusions and altered differentiation in muscle cell cultures from Huntington's disease subjects

Mutated huntingtin (htt) is ubiquitously expressed in tissues of Huntington's disease (HD) patients. In the brain, the mutated protein leads to neuronal cell dysfunction and death, associated with formation of htt-positive inclusions. Given increasing evidence of abnormalities in HD skeletal muscle, we extensively analyzed primary muscle cell cultures from seven HD subjects (including two unaffected mutation carriers). Myoblasts from presymptomatic and symptomatic HD subjects showed cellular abnormalities in vitro, namely mitochondrial depolarization, cytochrome c release, increased caspase-3, -8, and -9 activities, and defective cell differentiation. Another notable feature was the formation of htt inclusions in differentiated myotubes. This study helps to advance current knowledge about the downstream effects of the htt mutation in human tissues. Further applications may include drug screening using this human cellular model.

HESX1 expression in human normal pituitaries and pituitary adenomas

Hesx1 is a paired-like homeobox gene first expressed during mouse embryogenesis in the anterior midline visceral endoderm. As gastrulation proceeds, Hesx1 is expressed in the ventral prosencephalon and, subsequently, at E9.0 appears in the ventral diencephalon and in the thickened layer of oral ectoderm that give rise to Rathke's pouch, the primordium of the anterior pituitary gland. Hesx1 continues to be expressed in the developing anterior pituitary until E11.5 when its transcripts disappear in a spatiotemporal sequence corresponding to progressive pituitary cell differentiation, becoming undetectable by E15.5. In the present study, we investigated whether HESX1 is expressed during adult life in human normal pituitaries and in different types of human pituitary adenomas. We analysed, using quantitative RT-PCR method, three normal pituitaries, seven GH-, two TSH-, two PRL-, one ACTH-secreting adenomas, and seven nonfunctioning pituitary tumors. HESX1 mRNA was found to be expressed in normal pituitaries and in all the pituitary tumors that we have analysed. These results suggest that in humans HESX1 is not turned-off during the adult life as it occurs in mice. Thus, HESX1 in humans might play a role in the maintenance of the anterior pituitary cell types and function, as well as in the differentiation of pituitary adenomas, whose pathogenetic mechanisms remain to be further investigated. This is the first study on HESX1 expression in humans during adult life.

Adiponectin is a candidate marker of metabolic syndrome in obese children and adolescents

The aim of this study was to compare the use of several biomarkers to identify obese children and adolescents with increased metabolic risk. One hundred sixty-two Caucasian obese children and adolescents (41% males, 9-18 years old) referred to the Istituto Auxologico Italiano between 2003 and 2004 underwent an oral glucose tolerance test. Circulating levels of adiponectin (AD), plasminogen activator inhibitor 1 (PAI-1), interleukin 18 (IL-18), C-reactive protein (CRP), fibrinogen, uric acid, lipids and insulin were measured. Twenty five percent of obese children had the MS defined using World Health Organization-derived child specific criteria. MS subjects had significantly lower AD (p<0.01) and higher log-PAI-1 (p<0.001), uric acid (p<0.0001), and IL-18 (p<0.001). Subjects with AD levels </=median value had a significantly increased risk of having the MS (p<0.0001), as did subjects with uric acid and PAI-1 levels greater than the median. There was no increased risk with elevated IL-18, CRP, or fibrinogen. Hypoadiponectinemia was independently associated with the MS risk (p<0.0001). In conclusion in obese children and adolescents AD is the best predictor of MS and thus of higher cardiovascular disease risk.

Induction of a proinflammatory program in normal human thyrocytes by the RET/PTC1 oncogene

Rearrangements of the RET receptor tyrosine kinase gene generating RET/PTC oncogenes are specific to papillary thyroid carcinoma (PTC), the most frequent thyroid tumor. Here, we show that the RET/PTC1 oncogene, when exogenously expressed in primary normal human thyrocytes, induces the expression of a large set of genes involved in inflammation and tumor invasion, including those encoding chemokines (CCL2, CCL20, CXCL8, and CXCL12), chemokine receptors (CXCR4), cytokines (IL1B, CSF-1, GM-CSF, and G-CSF), matrix-degrading enzymes (metalloproteases and urokinase-type plasminogen activator and its receptor), and adhesion molecules (L-selectin). This effect is strictly dependent on the presence of the RET/PTC1 Tyr-451 (corresponding to RET Tyr-1062 multidocking site). Selected relevant genes (CCL20, CCL2, CXCL8, CXCR4, L-selectin, GM-CSF, IL1B, MMP9, UPA, and SPP1/OPN) were found up-regulated also in clinical samples of PTC, particularly those characterized by RET/PTC activation, local extrathyroid spread, and lymph node metastases, when compared with normal thyroid tissue or follicular thyroid carcinoma. These results, demonstrating that the RET/PTC1 oncogene activates a proinflammatory program, provide a direct link between a transforming human oncogene, inflammation, and malignant behavior.

In vitro evaluation of the effectiveness of the macrolide rokitamycin and chlorpromazine against Acanthamoeba castellanii

The present study demonstrates the in vitro effectiveness of the macrolide rokitamycin and the phenothiazine compound chlorpromazine against Acanthamoeba castellanii. Growth curve evaluations revealed that both drugs inhibit trophozoite growth in dose- and time-dependent ways. The effects of both drugs when they were used at the MICs at which 100% of isolates are inhibited were amoebistatic, but at higher doses they were amoebicidal as well as cysticidal. Experiments showed that when rokitamycin was associated with chlorpromazine or amphotericin B, rokitamycin enhanced their activities. Furthermore, low doses of rokitamycin and chlorpromazine, alone or in combination, blocked the cytopathic effect of A. castellanii against WKD cells derived from the human cornea. These results may have important significance in the development of new anti-Acanthamoeba compounds.

Differential requirement of Tyr1062 multidocking site by RET isoforms to promote neural cell scattering and epithelial cell branching

The receptor tyrosine kinase RET is alternatively spliced to yield two main isoforms, RET9 and RET51, which differ in their carboxyl terminal. Activated RET induces different biological responses such as morphological transformation, neurite outgrowth, proliferation, cell migration and branching. The two isoforms have been suggested to have separate intracellular signaling pathways and different roles in mouse development. Here we show that both isoforms are able to induce cell scattering of SK-N-MC neuroepithelioma cell line and branching tubule formation in MDCK cell line. However, the Y1062F mutation, which abrogates the transforming activity of both activated RET isoforms in NIH3T3 cells, does not abolish scattering and branching morphogenesis of RET51, whereas impairs these biological effects of RET9. The GDNF-induced biological effects of RET51 are inhibited by the simultaneous abrogation of both Tyr1062 and Tyr1096 docking sites. Thus, Tyr1096 may substitute the functions of Tyr1062. GRB2 is the only known adaptor protein binding to Tyr1096. Dominant-negative GRB2 expressed in MDCK cells together with RET9 or RET51 significantly reduces branching. Therefore, GRB2 is necessary for RET-mediated branching of MDCK cells.

Different basic fibroblast growth factor and fibroblast growth factor-antisense expression in eutopic endometrial stromal cells derived from women with and without endometriosis

In all species studied, the basic fibroblast growth factor (bFGF) gene is transcribed into multiple mRNAs, one of which is an antisense RNA (1B FGF-AS) probably involved in regulating the stability of the sense transcript. In this study we investigated whether the regulatory mechanisms of bFGF expression might be altered in endometrial stromal cells derived from women with endometriosis. bFGF and 1B FGF-AS mRNA levels were quantified in primary cultures of eutopic endometrial stromal cells derived from 29 women without endometriosis and 24 patients affected by the disease. When the data were analyzed according to the phase of the menstrual cycle, endometrial stromal cells derived from patients in the late proliferative phase showed significantly higher bFGF mRNA values and significantly lower 1B FGF-AS mRNA levels compared with control samples. Furthermore, the mean bFGF/1B FGF-AS mRNA ratio was significantly higher in endometrial stromal cells derived from patients compared with that in controls (mean +/- SEM, 2.31 +/- 0,55 and 0.77 +/- 0.14, respectively; P = 0.009). Moreover, for bFGF expression the differences existing at the mRNA level were maintained at the protein level. These findings support the hypothesis that 1B FGF-AS mRNA could regulate the expression of the sense transcript and suggest that in endometrial cells derived from patients, the presence of higher bFGF levels could improve their ability to proliferate at the ectopic site.

RET and NTRK1 proto-oncogenes in human diseases

RET and NTRK1 are receptor tyrosine kinase (RTK) proteins which play a role in the development and maturation of specific component of the nervous system. Their alterations have been associated to several human diseases, including some forms of cancer and developmental abnormalities. These features have contributed to the concept that one gene can be responsible for more than one disease. Moreover, both genes encoding for the two RTKs show genetic alterations that belong to either "gain of function" or "loss of function" class of mutations. In fact, receptor rearrangements or point mutations convert RET and NTRK1 in dominantly acting transforming genes leading to thyroid tumors, whereas inactivating mutations, associated with Hirschsprung's disease (HSCR) and congenital insensitivity to pain with anhidrosis (CIPA), impair RET and NTRK1 functions, respectively. In this review we have summarized the main features of the two receptors, their physiological and pathological roles. In addition, we attempted to identify the correlations between the different genetic alterations and the related pathogenetic mechanisms.

ADP and other metabolites released from Acanthamoeba castellanii lead to human monocytic cell death through apoptosis and stimulate the secretion of proinflammatory cytokines

Monocytes/macrophages are thought to be involved in Acanthamoeba infections. The aim of this work was to study whether soluble metabolites (ADP and other compounds) released by Acanthamoeba castellanii trophozoites could induce morphological and biochemical changes in human monocytic cells in vitro. We demonstrate here that ADP constitutively released in the medium by A. castellanii, interacting with specific P2y(2) purinoceptors expressed on the monocytic cell membrane, caused a biphasic rise in [Ca(2+)](i), morphological changes characteristics of cells undergoing apoptosis, caspase-3 activation, and secretion of tumor necrosis factor alpha (TNF-alpha). The same results were found in monocytes exposed to purified ADP. Cell damage and TNF-alpha release induced by amoebic ADP were blocked by the P2y(2) inhibitor suramin. Other metabolites contained in amoebic cell-free supernatants, with molecular masses of, respectively, >30 kDa and between 30 and 10 kDa, also caused morphological modifications and activation of intracellular caspase-3, characteristics of programmed cell death. Nevertheless, mechanisms by which these molecules trigger cell damage appeared to differ from that of ADP. In addition, other amoebic thermolable metabolites with molecular masses of <10 kDa caused the secretion of interleukin-1beta. These findings suggest that pathogenic free-living A. castellanii by release of ADP and other metabolites lead to human monocytic cell death through apoptosis and stimulate the secretion of proinflammatory cytokines.

Germline mutations of TSH receptor gene as cause of nonautoimmune subclinical hypothyroidism

Germline loss-of-function mutations of TSH receptor (TSHR) gene have been described in families with partial or complete TSH resistance. Large TSH elevations were generally found in the patients with homozygous or compound heterozygous mutations. In this study, we sequenced the entire TSHR gene in a series of 10 unrelated patients with slight (6.6-14.9 mU/liter) to moderate (24-46 mU/liter) elevations of serum TSH, associated with definitely normal free thyroid hormone concentrations. Thyroid volume was normal in all patients, except two with a modest hypoplasia. Autoimmune thyroid disease was excluded in all patients on the basis of clinical and biochemical parameters. Eight patients had at least one first-degree relative bearing the same biochemical picture. TSHR mutations were detected in 4 of 10 cases by analyzing DNA from peripheral leukocytes. A compound heterozygosity (P162A on maternal allele, and the novel mutation C600R on the paternal one) was found in the patient with the highest TSH levels. Only one TSHR allele was mutated in the remaining three cases, and no alterations in TSHR gene promoter were detected in all of these probands. A novel mutation (L467P) was detected on the maternal allele in one patient and in her monozygotic twin. Previously described inactive mutants, T655Delta and C41S, were detected in the other two cases. When tested on several occasions, circulating TSH values fluctuating above the upper limit of the normal range could be shown in heterozygous subjects of these families. A dominant mode of inheritance of the biochemical alterations was detected in these cases. Mutant TSHRs were studied during transient expression in COS7 and HEK293T cells. Their TSH-independent cAMP accumulation activities were very low or similar to mock-transfected cells, and no increases were seen after maximal hormone stimulation. Flow cytometry experiments showed a poor level of expression of all mutant TSHRs at the cell membrane. In conclusion, we found several loss-of-function mutations of TSHR, including two novel ones, in a series of unrelated patients with slightly elevated TSH levels. Therefore, partial resistance to TSH action is a frequent finding among patients with slight hyperthyrotropinemia of nonautoimmune origin. Germline mutations of TSHR may be associated with serum TSH values fluctuating above the upper limit of the normal range, also in the heterozygous state.

Multigenerational familial medullary thyroid cancer (FMTC): evidence for FMTC phenocopies and association with papillary thyroid cancer

BACKGROUND

Occurrence in a familial setting is well established for medullary thyroid carcinoma (MTC) and has been more recently reported for papillary thyroid cancer (PTC). Germline mutations or rearrangements of the RET proto-oncogene are the genetic background of the majority of hereditary MTCs and of about 25-40% of PTCs.

PATIENTS

A large multigenerational familial medullary thyroid cancer (FMTC) family, comprised of four generations and a total of 60 subjects, has been fully evaluated. Studies on germline RET mutations and polymorphisms, on somatic RET activation and on haplotyping with RET-linked markers, were performed.

RESULTS

RET mutational analysis revealed a rare missense point mutation in exon 15 of RET (A891S), associated with FMTC. Haplotype analysis showed a co-segregation between the allelic variant 5 of D10S578 marker (which is tightly linked to the RET locus) and the RET mutation. Two patients, from different branches of the family, did not harbour the point mutation A891S despite histological confirmation of MTC. In these cases, haplotype analysis excluded the involvement of the RET gene itself in the pathogenesis of the MTC. In three patients, the coexistence, in different foci, of medullary and papillary thyroid cancer was documented. The genetic studies did not show ret/PTC rearrangements. The microsatellite analysis excluded co-segregation of RET locus with the MTC/PTC phenotype.

CONCLUSIONS

We report a full clinical and molecular analysis of a large FMTC kindred with an uncommon RET mutation. In two family members, phenotype and genotype were not concordant, representing the first evidence of FMTC phenocopies. Furthermore, the association of familial forms of medullary and papillary thyroid cancers has been found in 30% of patients undergoing thyroidectomy for MTC. In these situations, genetic analyses excluded the possible germline involvement of RET. Though FMTC phenocopies are likely to represent an exceptional finding, such a possibility should be taken into account in the genetic counselling for MEN 2 syndromes.

[Psychooncological aspects in the care of females in HNPCC families]

HNPCC families are characterized by a genetic predisposition for colorectal and other cancers. In Düsseldorf we pursue an interdisciplinary counselling approach (geneticists, psychologists and surgeons). Apart from the genetic counselling itself, special emphasis is placed on the benefits of surveillance and screening recommendations. In this pilot study we were interested in investigating if the counselled women had understood the increased risk of gynecological cancers and correspondingly underwent the intensified screening modalities. We selected the approach of a telefone interview and encountered broad acceptance for contacting persons this way. Affected women are better compliant to screening recommendations than women at risk. Both groups consider colonoscopy more strainful than gynecological surveillance. A regular transvaginal ultrasound is not performed in some 40 % of at risk women although 2/3 of them see their gynecologist in regular intervals. Given the support of gynecologists a higher rate of transvaginal ultrasound in women at risk should be achievable.

Lack of antitumor activity of recombinant endostatin in a human neuroblastoma xenograft model

Patients with metastatic neuroblastoma are rarely curable with currently available therapy, and the search for new treatment options, which include the use of inhibitors of tumor angiogenesis, is warranted. Here, we have evaluated the efficacy of one of the most promising natural inhibitors of angiogenesis described to date, endostatin, in a human neuroblastoma xenograft model in nude mice. Murine endostatin cDNA was cloned in a bacterial expression vector, expressed as a polyHis-Endostatin fusion protein and purified on Ni2+-NTA beads. The in vitro activity of soluble endostatin was confirmed on bovine capillary endothelial cells and human umbilical vein endothelial cells. The human neuroblastoma cell line SKNAS was injected subcutaneously in the flank of nude mice and administration of the recombinant angiogenesis inhibitor started when tumors reached the size of 100 microm3. Twenty mg/kg of recombinant precipitated endostatin or PBS was subcutaneously injected daily for 12 days. Serum endostatin levels were measured using a competitive enzyme immunoassay. Tumor growth was only slowed down in endostatin-treated mice when compared to control mice, and no statistically significant difference in serum levels of endostatin was observed between endostatin-treated and control groups. The lack of correlation between serum concentration and tumor response raises concern regarding the mechanism of action of endostatin.

A novel germline mutation in the TSH receptor gene causes non-autoimmune autosomal dominant hyperthyroidism

OBJECTIVE

Clinical and genetic investigations were undertaken in a case of familial hyperthyroidism, with onset of thyrotoxic symptoms varying between childhood/adolescence.

METHODS

Automatic sequence analysis was carried out of the TSH receptor (TSHR) gene. Functional studies were undertaken of mutant TSHR in transient expression experiments in COS-7 cells including the evaluation of cAMP accumulation and of protein expression by flow cytometry, as well as the calculation of specific constitutive activity (SCA).

RESULTS

In four affected cases, the age of onset of thyrotoxic manifestations of non-autoimmune origin varied between 5 and 18 years. The disease transmission was typically autosomal dominant. TSHR gene sequence revealed the presence of a germline heterozygous substitution at codon 597 leading to the novel mutation V597F. This residue is located in the 5th transmembrane domain of the receptor protein in a critical region for membrane targeting and signal transduction. Functional studies of the V597F mutant indicate an 11-fold increase in SCA, associated with a reduction in receptor protein expression on the cytoplasmic membrane.

CONCLUSIONS

Description was made of a family with non-autoimmune autosomal dominant hyperthyroidism carrying a novel mutation of TSHR leading to the increment in specific constitutive activity. Factors that may influence the clinical expression of TSHR germline mutations are discussed.

Absence of thyroid transcription factor-1 expression in human parathyroid and pituitary glands

Thyroid transcription factor-1 (TTF-1), a tissue-specific nuclear transcription factor involved in the embryogenesis and differentiation of human thyroid, lung and brain, has been recently identified in other rat tissues, including parafollicular C cells and parathyroid chief cells. Based on this distribution, a possible role for this factor in calcium homeostasis has been suggested. This study investigated the presence of TTF-1 transcripts and protein in human tissues expressing the calcium sensing receptor (CaSR). Using a RT-PCR technique, complemented by Southern blot analysis, TTF-1 expression was detected in human C cells (two medullary thyroid carcinomas), but not in normal and adenomatous (four adenomas and three hyperplasia) parathyroid, and normal and adenomatous (six adenomas) pituitary tissues. CaSR was expressed in all samples. The absence of expression was confirmed by Western blot. In contrast to previous studies in the rat, this study demonstrates the absence of TTF-1 transcripts in the human adult parathyroid and pituitary glands, although a role for this factor during the ontogeny of these organs cannot be excluded.

Role of diabetes in influencing leptin concentration in elderly overweight patients

BACKGROUND

Leptin, the product of the ob gene, could have a significant role in the pathogenesis of obesity and non-insulin-dependent diabetes mellitus. However, it is still debated whether different degrees of glucose tolerance may affect plasma leptin concentrations in obese patients.

OBJECTIVE

To investigate whether diabetes might influence leptin concentrations in obese patients.

METHODS

We evaluated clinical parameters, anthropometric measures, and sex hormones, fasting plasma leptin, glucose and insulin concentrations in 100 elderly obese diabetic patients and 100 obese non-diabetic control individuals matched for age and sex.

RESULTS

After adjustment for age and fat mass, plasma leptin concentrations did not differ between diabetic and non-diabetic obese individuals, in both men and women. In all patients leptin was significantly related to body mass index, fat mass and the homeostasis model insulin resistance index; moreover we observed a significant relationship with fasting plasma glucose and age in diabetic obese women, and with blood pressure values and testosterone concentrations in diabetic obese men. Multiple regression analysis revealed age and fasting plasma glucose to be the only independent determinants of fasting plasma leptin in diabetic obese women.

CONCLUSIONS

These data suggest that leptin concentrations do not differ between obese diabetic and obese non-diabetic elderly patients. Among correlates of the metabolic syndrome, systolic pressure seems to be related to leptin only in men. In the postmenopausal or andropausal status, sex hormones are related to leptin concentrations only in diabetic men; in diabetic women, however, high glucose seems to be relevant in maintaining the same leptin concentrations as in non-diabetic women with similar degree of obesity.

Plasma homocysteine, methylenetetrahydrofolate reductase mutation and carotid damage in elderly healthy women

Plasma homocysteine (Hcy) is an independent vascular risk factor. Its remethylation to methionine is regulated by the activity of the enzyme 5,10-methylene tetrahydrofolate reductase (MTHFR). A C-to-T substitution at nucleotide 677 of the MTHFR gene is frequently associated to hyperhomocysteinemia. In this study, we evaluated the relationship among MTHFR C677T polymorphism, Hcy and some ultrasonographic parameters at the level of carotid arteries in 120 elderly women with normal ECG, normal blood pressure values, total cholesterol <250 mg/dl, normal glucose tolerance, normal albumin excretion rate. In all subjects, we measured Hcy by HPLC, MTHFR mutation by polymerase chain reaction followed by HinfI digestion and intima-media thickness (IMT), peak velocity of the systolic flow (SP(V)), end-diastolic velocity (ED(V)) and resistance and pulsatility indexes of intracranial circulation (RI and PI) by ultrasound imaging. Twenty-eight women were homozygotes for the wild type allele (Ala/Ala), 72 were heterozygotes (Ala/Val) and 20 were homozygotes for the mutation (Val/Val). Groups were comparable for age, blood pressure values and plasma lipid levels. Hcy was higher in Val/Val group; moreover, after adjustment for confounding factors, Val/Val had significantly greater IMT and ED(V) (P<0.001 and P<0.05, respectively). Logistic analysis revealed that Val/Val genotype was the strongest risk factor for IMT (OR 30.8, 95% CI 2.82-335.6). Our results show that, in elderly healthy women, Val/Val homozygosity for C677T mutation in MTHFR gene could identify subjects at risk for asymptomatic carotid atherosclerotic impairment.

Key role of Shc signaling in the transforming pathway triggered by Ret/ptc2 oncoprotein

The RET/PTC oncogenes, generated by chromosomal rearrangements in papillary thyroid carcinomas, are constitutively activated versions of protoRET, a gene encoding two protein isoforms of a transmembrane tyrosine kinase receptor. By using Ret/ptc2 short isoform (iso9), we have previously demonstrated that Tyr586 (Tyr1062 of protoRet) is the docking site for both the PTB and the SH2 domains of Shc. To determine the relevance of this interaction for the transforming activity of Ret/ptc oncogenes, we have generated and characterized novel Ret/ptc mutants unable to activate Shc: Ret/ptc2 long isoform (iso51)-Y586F and both isoforms of Ret/ptc2-N583A. These mutants neither activate Shc nor transform NIH3T3 cells. Since Tyr1062 shows features of a multifunctional docking site, we have used a Shc mutant (Shc Y317F) to directly assess Shc role. We have demonstrated that in our cell system Shc Y317F behaves like a dominant interfering mutant on the activation of the Grb2-Sos pathway by endogenous Shc triggered by Ret/ptc2. A strong reduction of the transforming activity of Ret/ptc2 in presence of this mutant was also demonstrated. Our data suggest that Shc activation play a key role in the transforming pathways triggered by Ret/ptc oncoproteins. Moreover, we have shown that coexpression of the Shc-Y317F mutant with Ret/ptc2 specifically causes apoptosis, and that the surviving cells lose the long-term expression of one of the two genes.

IL-4 prevents the blockade of dendritic cell differentiation induced by tumor cells

Malignant cells may escape from the immune response in vivo because of a defective differentiation of professional antigen-presenting cells (APCs), i.e., dendritic cells (DCs). We recently reported that tumor cells release interleukin (IL)-6 and macrophage colony stimulating factor (M-CSF), which inhibit the differentiation of CD34+ cells into DCs and promote their commitment toward monocytic lineage with a poor APC function. The results presented here show that both IL-4 and IL-13 reverse the inhibitory effects of renal cell carcinoma conditioned media (RCC CM) or IL-6+M-CSF on the phenotypic and functional differentiation of CD34+ into DCs. IL-4 was found to act through a rapid blockade of the expression of M-CSF and the IL-6 receptor-transducing chain (gp130), along with a decrease of the secondary production of M-CSF, thereby preventing the loss of granulocyte macrophage colony stimulating factor (GM-CSF) receptor alpha chain expression on differentiating CD34+ cells. Consistent with these observations, the differentiation of DCs from monocytes cultured with GM-CSF and IL-4 was also impaired by RCC CM, but the minimal inhibitory concentrations of RCC CM were 10-fold higher than for CD34+ cells. In these conditions, monocytes cultured with GM-CSF and IL-4 also exhibited profound phenotypic changes (CD14+ D32+ CD86+ HLA-DR+ CD115(low) CD23(low) CD1a-) and a poor APC function. These alterations were overcome in a dose-dependent manner by IL-4 (5-500 IU/ml), although not beyond a 40% final concentration of RCC CM. The capacity of RCC CM to block DC differentiation from monocytes strongly correlated with IL-6 and M-CSF concentrations in medium. Taken together, these results demonstrate that IL-4 and IL-13 reverse the inhibitory effect of tumor cells on DC differentiation.

Relationship between metabolic glycaemic control and platelet content of glutathione and its related enzymes, in insulin-dependent diabetes mellitus

The relationship between glycaemic metabolic control and intracellular concentration of reduced glutathione (GSH) and related enzymes GSH-peroxidase (GSH-Px), GSH-reductase (GSH-Red), GSH-transferase (GSH-Tr), glucose-6-P-dehydrogenase (G6PDH), and thioltransferase (TT) in patients with insulin-dependent diabetes mellitus (IDDM) is controversial. Choosing platelets as cell model (as commonly done in previous studies), the aim of this study was to relate the platelet content of GSH and related enzymes to glycaemic metabolic control, expressed as glycated haemoglobin (HbA1c), as well as to presence of retinopathy and nephropathy in 114 IDDM patients. As compared to controls, both GSH and GSH-Red (geometric means (95% CI)) were significantly increased in platelets of diabetic patients: 3.3 (0.7-9.6) vs. 2.4 (0.8-7.6) mmol 10(-9) platelets; P=0.01 for GSH, and 30.6 (14.7-61.6) vs. 22.2 (8.7-52.2) mU 10(-9) platelets, P=0.0002 for GSH-Red, and TT activity was marginally decreased in the IDDM group (P=0.06). While no clear relationship was present between GSH-related enzymes and HbA1c, a trend was present toward a non-linear relation between HbA1c and GSH, being significantly related by a parabolic curve (P=0.002). As compared to patients with normoalbuminuria (n=88), diabetic patients with increased urinary albumin excretion rate (n=26) had a significant decrease in platelet TT concentration (3.2 (0.9-6.7) vs. 5.1 (1.9-18.7) mU 10(-9) platelets; P=0.0002), whereas retinopathy was not associated to modifications in GSH or in the enzymatic pattern. In summary: (a) platelet GSH and GSH-Red are increased in IDDM, while other enzymes are unmodified; (b) GSH seems to be related to metabolic control according to non-linear parabolic curve; (c) presence of increased albuminuria is associated to a selective decrease in platelet TT content.

Induction of specific phosphodiesterase isoforms by constitutive activation of the cAMP pathway in autonomous thyroid adenomas

Thyrocytes largely depend on cAMP signaling for replication and differentiation. This pathway may be constitutively activated by mutations of the TSH receptor (TSHR) and Gsalpha in autonomous thyroid adenomas (ATAs). Because steady state cAMP results from production by adenylyl cyclase and degradation by phosphodiesterases (PDEs), we evaluated PDE activity and expression in ATAs with wild-type and mutant TSHR and Gsalpha. Activating mutations of TSHR and Gsalpha were identified in 7 and 1 of 18 ATAs, respectively. No difference was observed in the cAMP content in ATAs with or without activating mutants. In the surrounding normal thyroid tissue (NTs), PDE activity was 80% isobutylmethylxanthine sensitive, with the major contribution by PDE1 and a minor contribution by PDE4. No differences were observed in PDE activities between NTs and ATAs with wild-type TSHR and Gsalpha. In contrast, in the presence of mutant TSHRs or Gsalpha, total PDE activity was higher. This increase was primarily due to PDE4 induction (917 +/- 116% over NTs), associated with a minor PDE1 increase only in ATAs with mutant TSHR. By RT-PCR, increments of PDE4D and 4C messenger ribonucleic acids were found in the ATAs with mutant TSHR or Gsalpha, whereas messenger ribonucleic acids encoding other cAMP-specific PDEs were not significantly increased. This study provides a characterization of the PDEs expressed in human thyroid and demonstrates a dramatic PDE4 induction in the ATAs bearing mutant TSHR or Gsalpha genes. The increase in cAMP-degrading activity may represent a marker of constitutive adenylyl cyclase activation and constitutes an intracellular feedback mechanism with significant impact on the phenotypic expression of the activating mutations.

The relationship of plasma glucose and electrocardiographic parameters in elderly women with different degrees of glucose tolerance

Plasma glucose has been regarded as a risk factor for macrovascular complications in diabetes, but less is known about its role in the development of cardiac impairment other than coronary heart disease (CHD). The aim of our study was to determine the relationship between basal and post-OGTT (Oral Glucose Tolerance Test) plasma glucose levels and some ECG parameters in a group of elderly women with normal or impaired glucose tolerance (IGT). One-hundred and one women with normal fasting glucose (<6.0 mmol/L) and no familial history or clinical signs of CHD and diabetes underwent an OGTT and a resting ECG. Based on the degree of glucose tolerance, we identified 24 women with a diagnostic OGTT for either IGT or diabetes; the 77 women (age range 52-88 years) with normal glucose tolerance were further divided into two groups according to their post-OGTT area under the curve (AUCG): below and above the median value (32 and 45 women, respectively). Basal plasma glucose and insulin levels, as well as lipid profile and percent of hypertensive patients were similar in the three groups. Mean corrected QT (QTc) was prolonged as a function of progressive worsening of glucose tolerance even after adjustment for possible confounding factors (p=0.03). A similar relationship was apparent when post-OGTT plasma glucose peak (GP) was considered. In a multiple regression analysis, AUCG and GP were the only factors independently related to both QTc and Sokolow index. Our observations suggest that, even in the presence of a normal glucose tolerance, plasma glucose concentrations during an OGTT are associated with peculiar ECG signs potentially combined with an increased risk of sudden death, arrhythmias, or cardiovascular mortality.