Gut microbiota and fecal volatilome profile inspection in metabolically healthy and unhealthy obesity phenotypes.

BACKGROUND: People with metabolically healthy (MHO) and metabolically unhealthy obesity (MUO) differ for the presence or absence of cardio-metabolic complications, respectively. OBJECTIVE: Based on these differences, we are interested in deepening whether these obesity phenotypes could be linked to changes in microbiota and metabolome profiles. In this respect, the overt role of microbiota taxa composition and relative metabolic profiles is not completely understood. At this aim, biochemical and nutritional parameters, fecal microbiota, metabolome and SCFA compositions were inspected in patients with MHO and MUO under a restrictive diet regimen with a daily intake ranging from 800 to 1200 kcal. METHODS: Blood, fecal samples and food questionnaires were collected from healthy controls (HC), and an obese cohort composed of both MHO and MUO patients. Most impacting biochemical/anthropometric variables from an a priori sample stratification were detected by applying a robust statistics approach useful in lowering the background noise. Bacterial taxa and volatile metabolites were assessed by qPCR and gas chromatography coupled with mass spectrometry, respectively. A targeted GC-MS analyses on SCFAs was also performed. RESULTS: Instructed to follow a controlled and restricted daily calorie intake, MHO and MUO patients showed differences in metabolic, gut microbial and volatilome signatures. Our data revealed higher quantities of specific pro-inflammatory taxa (i.e., Desulfovibrio and Prevotella genera) and lower quantities of Clostridium coccoides group in MUO subset. Higher abundances in alkane, ketone, aldehyde, and indole VOC classes together with a lower amount of butanoic acid marked the faecal MUO metabolome. CONCLUSIONS: Compared to MHO, MUO subset symptom picture is featured by specific differences in gut pro-inflammatory taxa and metabolites that could have a role in the progression to metabolically unhealthy status and developing of obesity-related cardiometabolic diseases. The approach is suitable to better explain the crosstalk existing among dysmetabolism-related inflammation, nutrient intake, lifestyle, and gut dysbiosis.

Ketogenic nutritional therapy (KeNuT)-a multi-step dietary model with meal replacements for the management of obesity and its related metabolic disorders: a consensus statement from the working group of the Club of the Italian Society of Endocrinology (SIE)-diet therapies in endocrinology and metabolism.

PURPOSE: The ketogenic nutritional therapy (KeNuT) is an effective dietary treatment for patients with obesity and obesity-related comorbidities, including type 2 diabetes, dyslipidaemia, hypertension, coronary artery disease, and some type of cancers. However, to date an official document on the correct prescription of the ketogenic diet, validated by authoritative societies in nutrition or endocrine sciences, is missing. It is important to emphasize that the ketogenic nutritional therapy requires proper medical supervision for patient selection, due to the complex biochemical implications of ketosis and the need for a strict therapeutic compliance, and an experienced nutritionist for proper personalization of the whole nutritional protocol. METHODS: This practical guide provides an update of main clinical indications and contraindications of ketogenic nutritional therapy with meal replacements and its mechanisms of action. In addition, the various phases of the protocol involving meal replacements, its monitoring, clinical management and potential side effects, are also discussed. CONCLUSION: This practical guide will help the healthcare provider to acquire the necessary skills to provide a comprehensive care of patients with overweight, obesity and obesity-related diseases, using a multistep ketogenic dietary treatment, recognized by the Club of the Italian Society of Endocrinology (SIE)-Diet Therapies in Endocrinology and Metabolism.

Pharmacological modulation of adaptive thermogenesis: new clues for obesity management?

BACKGROUND: Adaptive thermogenesis represents the main mechanism through which the body generates heat in response to external stimuli, a phenomenon that includes shivering and non-shivering thermogenesis. The non-shivering thermogenesis is mainly exploited by adipose tissue characterized by a brown aspect, which specializes in energy dissipation. A decreased amount of brown adipose tissue has been observed in ageing and chronic illnesses such as obesity, a worldwide health problem characterized by dysfunctional adipose tissue expansion and associated cardiometabolic complications. In the last decades, the discovery of a trans-differentiation mechanism ("browning") within white adipose tissue depots, leading to the generation of brown-like cells, allowed to explore new natural and synthetic compounds able to favour this process and thus enhance thermogenesis with the aim of counteracting obesity. Based on recent findings, brown adipose tissue-activating agents could represent another option in addition to appetite inhibitors and inhibitors of nutrient absorption for obesity treatment. PURPOSE: This review investigates the main molecules involved in the physiological (e.g. incretin hormones) and pharmacological (e.g. ß3-adrenergic receptors agonists, thyroid receptor agonists, farnesoid X receptor agonists, glucagon-like peptide-1, and glucagon receptor agonists) modulation of adaptive thermogenesis and the signalling mechanisms involved.

A telemedicine-based approach with real-time transmission of blood glucose data improves metabolic control in insulin-treated diabetes: the DIAMONDS randomized clinical trial.

PURPOSE: To evaluate if a web-based telemedicine system (the Glucoonline® system) is effective to improve glucose control in insulin-treated patients with type 1 and type 2 diabetes, as compared to standard of care. METHODS: This was a prospective, randomized, controlled trial, carried out at three tertiary referral centers for diabetes in Italy. Adults with insulin-treated type 1 and type 2 diabetes, inadequate glycemic control, and no severe diabetes-related complications and/or comorbidities were eligible for this study. Patients were randomized to either perform telemedicine-assisted (Group A) or standard (Group B) self-monitoring blood glucose (SMBG) for 6 months. In Group A, patients received prompt feedback about their blood glucose levels and therapy suggestions from the study staff via phone/SMS, when appropriate. In Group B, patients had no remote assistance from the study staff between planned visits. RESULTS: 123 patients were included in the final analysis. After 6 months, patients achieved a significant reduction in HbA1c in Group A (-0.38%, p < 0.05) but not in Group B (+ 0.08%, p = 0.53). A significant difference in the percentage of patients with HbA1c < 7% between Group A and Group B was found after 3 months (28.6% vs 11.1%, p = 0.02). Also, fewer patients (p < 0.05) with HbA1c > 8.5% were found in Group A vs Group B, respectively, after both 3 months (14.3% vs 35.2%) and 6 months (21.8% vs 42.9%). CONCLUSIONS: The use of the Glucoonline™ system resulted in improved metabolic control. Telemedicine services have potential to support diabetes self-management and provide the patients with remote, prompt assistance using affordable technological equipment. Trial registration This study was registered at clinicaltrials.gov (NCT01804803) on March 5, 2013.

Postprandial glucose and HbA1c are associated with severity of obstructive sleep apnoea in non-diabetic obese subjects.

INTRODUCTION: Obstructive sleep apnoea (OSA) is an underdiagnosed condition frequently associated with glycaemic control impairment in patients with type 2 diabetes. AIM: To assess the relationship between glycometabolic parameters and OSA in obese non-diabetic subjects. METHODS: Ninety consecutive subjects (mean age 44.9 ± 12 years, mean BMI 42.1 ± 9 kg/m2) underwent polysomnography and a 2-h oral glucose tolerance test (OGTT). RESULTS: OSA was identified in 75% of subjects, with a higher prevalence of males compared to the group of subjects without OSA (62% vs 32%, p = 0.02). Patients with OSA had comparable BMI (42.8 kg/m2 vs 39.4 kg/m2), a higher average HbA1c (5.8% vs 5.4%, p < 0.001), plasma glucose at 120 min during OGTT (2 h-PG; 123 mg/dl vs 97 mg/dl, p = 0.009) and diastolic blood pressure (81.1 mmHg vs 76.2 mmHg, p = 0.046) than obese subjects without OSA. HbA1c and 2 h-PG were found to be correlated with the apnoea-hypopnoea index (AHI; r = 0.35 and r = 0.42, respectively) and with percent of sleep time with oxyhaemoglobin saturation < 90% (ST90; r = 0.44 and r = 0.39, respectively). Further, in a linear regression model, ST90 and AHI were found to be the main determinants of 2 h-PG (ß = 0.81, p < 0.01 and ß = 0.75, p = 0.02, respectively) after controlling for age, sex, waist circumference, physical activity, and C-reactive protein. Similarly, ST90 and AHI persisted as independent determinants of HbA1c (ß = 0.01, p = 0.01 and ß = 0.01, p = 0.01, respectively). CONCLUSION: Beyond the traditional clinical parameters, the presence of a normal-high value of 2 h-PG and HbA1c should raise suspicion of the presence of OSA in obese subjects.

Dysmetabolic adipose tissue in obesity: morphological and functional characteristics of adipose stem cells and mature adipocytes in healthy and unhealthy obese subjects.

The way by which subcutaneous adipose tissue (SAT) expands and undergoes remodeling by storing excess lipids through expansion of adipocytes (hypertrophy) or recruitment of new precursor cells (hyperplasia) impacts the risk of developing cardiometabolic and respiratory diseases. In unhealthy obese subjects, insulin resistance, type 2 diabetes, hypertension, and obstructive sleep apnoea are typically associated with pathologic SAT remodeling characterized by adipocyte hypertrophy, as well as chronic inflammation, hypoxia, increased visceral adipose tissue (VAT), and fatty liver. In contrast, metabolically healthy obese individuals are generally associated with SAT development characterized by the presence of smaller and numerous mature adipocytes, and a lower degree of VAT inflammation and ectopic fat accumulation. The remodeling of SAT and VAT is under genetic regulation and influenced by inherent depot-specific differences of adipose tissue-derived stem cells (ASCs). ASCs have multiple functions such as cell renewal, adipogenic capacity, and angiogenic properties, and secrete a variety of bioactive molecules involved in vascular and extracellular matrix remodeling. Understanding the mechanisms regulating the proliferative and adipogenic capacity of ASCs from SAT and VAT in response to excess calorie intake has become a focus of interest over recent decades. Here, we summarize current knowledge about the biological mechanisms able to foster or impair the recruitment and adipogenic differentiation of ASCs during SAT and VAT development, which regulate body fat distribution and favorable or unfavorable metabolic responses.

Long-acting insulin analog detemir displays reduced effects on adipocyte differentiation of human subcutaneous and visceral adipose stem cells.

BACKGROUND AND AIMS: Since treatment with insulin detemir results in a lower weight gain compared to human insulin, we investigated whether detemir is associated with lower ability to promote adipogenesis and/or lipogenesis in human adipose stem cells (ASC). METHODS AND RESULTS: Human ASC isolated from both the subcutaneous and visceral adipose tissues were differentiated for 30 days in the presence of human insulin or insulin detemir. Nile Red and Oil-Red-O staining were used to quantify the rate of ASC conversion to adipocytes and lipid accumulation, respectively. mRNA expression levels of early genes, including Fos and Cebpb, as well as of lipogenic and adipogenic genes, were measured at various phases of differentiation by qRT-PCR. Activation of insulin signaling was assessed by immunoblotting. ASC isolated from subcutaneous and visceral adipose tissue were less differentiated when exposed to insulin detemir compared to human insulin, showing lower rates of adipocyte conversion, reduced triglyceride accumulation, and impaired expression of late-phase adipocyte marker genes, such as Pparg2, Slc2a4, Adipoq, and Cidec. However, no differences in activation of insulin receptor, Akt and Erk and induction of the early genes Fos and Cebpb were observed between insulin detemir and human insulin. CONCLUSION: Insulin detemir displays reduced induction of the Pparg2 adipocyte master gene and diminished effects on adipocyte differentiation and lipogenesis in human subcutaneous and visceral ASC, in spite of normal activation of proximal insulin signaling reactions. These characteristics of insulin detemir may be of potential relevance to its weight-sparing effects observed in the clinical setting.

Parvovirus B19 associated acute cholestatic hepatitis.

There are few reports in the literature of hepatitis as a manifestation of Parvovirus B19 infection. We describe a case of Parvovirus B19 associated acute cholestatic hepatitis diagnosed based on a positive serologic test (IgM) and molecular detection of parvovirus B19 DNA in peripheral blood. Parvovirus B19 infection should be considered in the differential diagnosis of patient presenting with acute hepatitis of unknown etiology.

Glucagon-like peptide-1 counteracts oxidative stress-dependent apoptosis of human cardiac progenitor cells by inhibiting the activation of the c-Jun N-terminal protein kinase signaling pathway.

Increased apoptosis of cardiac progenitor cells (CPCs) has been proposed as a mechanism of myocardial damage and dysfunction. Glucagon-like peptide-1 (GLP-1) has been shown to improve heart recovery and function after ischemia and to promote cell survival. The protective effects of GLP-1 on oxidative stress-induced apoptosis were investigated in human CPCs isolated from human heart biopsies. Mesenchymal-type cells were isolated from human heart biopsies, exhibited the marker profile of CPCs, differentiated toward the myocardiocyte, adipocyte, chondrocyte, and osteocyte lineages under appropriate culture conditions, and expressed functional GLP-1 receptors. CPCs were incubated with GLP-1 with or without hydrogen peroxide (H(2)O(2)). Phospho- and total proteins were detected by immunoblotting and immunofluorescence analysis. Gene expression was evaluated by quantitative RT-PCR. The role of the canonical GLP-1 receptor was assessed by using the receptor antagonist exendin(9-39) and receptor-specific silencer small interfering RNAs. Cell apoptosis was quantified by an ELISA assay and by flow cytometry-detected Annexin V. Exposure of CPCs to H(2)O(2) induced a 2-fold increase in cell apoptosis, mediated by activation of the c-Jun N-terminal protein kinase (JNK) pathway. Preincubation of CPCs with GLP-1 avoided H(2)O(2)-triggered JNK phosphorylation and nuclear localization, and protected CPCs from apoptosis. The GLP-1 effects were markedly reduced by coincubation with the receptor antagonist exendin(9-39), small interfering RNA-mediated silencing of the GLP-1 receptor, and pretreatment with the protein kinase A inhibitor H89. In conclusion, activation of GLP-1 receptors prevents oxidative stress-mediated apoptosis in human CPCs by interfering with JNK activation and may represent an important mechanism for the cardioprotective effects of GLP-1.

[Surveillance of infection events in neonatal intensive care]. / Sorveglianza degli eventi infettivi in TIN.

Nosocomial infections are one of the major causes of morbidity and mortality in the newborn intensive care unit (NICU). They result in prolonged hospital stays and increased hospital costs. Neonates are susceptible hosts because of prematurity of organ systems, immaturity of immune system, low birth weight and the use of invasive devices. Most infections are endemic others can occur during outbreaks. As advances in medical technology improve mortality in the tiniest of infants, it is imperative that health care providers identify effective interventions to minimize the risks of nosocomial infections in the NICU. Recommended infection control and prevention strategies are: hand washing promotion, decreased use of invasive procedures, limited antitibiotic exposure, environmental hygiene. In this context infection surveillance is the first step to recognize and analyze problems, to effectively target infection control measures and feedback. Any suspicion of an outbreak should lead to a review of general infection control procedures to prevent the spread of the pathogens as quickly as possible. A multidisciplinary approach can be an effective means of developing a plan of action to apply prolonged and strict adherence to isolation precautions', to detect potential reservoirs or source of infections, to educate every member of the patient care team and to review NICU protocols.

Metabolic implications of growth hormone therapy.

GH regulates important physiological processes, including somatic growth and development, and carbohydrate and lipid metabolism. GH deficiency and GH replacement therapy exert opposite effects on body composition and fat accumulation, suggesting that GH may directly regulate adipocyte functions. Multiple studies have shown that in tissues previously deprived of GH, short-term stimulation with GH is able to mimic the actions of insulin, including stimulation of amino-acid and glucose transport, and lipogenesis. However, the antagonistic effects of GH on insulin-mediated metabolic responses are well-documented: GH excess in patients with GH-producing pituitary tumors causes hyperinsulinemia, insulin resistance, and even clinical diabetes mellitus. These apparently contradictory effects may be explained at the molecular level by the complex interplay between GH and insulin signaling. In this review, we examine the consequences of acute and chronic effects of GH on visceral fat and on metabolic responses in adipocytes, and discuss experimental data illustrating the integrated crosstalk between GH and insulin.

Pai syndrome: a further report of a case with bifid nose, lipoma, and agenesis of the corpus callosum.

INTRODUCTION: Pai syndrome is a rare genetic disorder mainly characterized by the association of complete median cleft of palate and upper lip, midline facial cutaneous, and mid-anterior alveolar process polyps, duplicated maxillary median frenulum, bifid nose, and midline lipoma(s) of the central nervous system, in particular, the corpus callosum. The incidence of this syndrome is much higher in males than in females. The etiology remains unknown: The syndrome may be associated with autosomal-dominant inheritance, but X-linked recessive inheritance could not be excluded. DISCUSSION: A de novo apparently balanced reciprocal traslocation, 46,X,t(X;16) has been described in a 13-year-old girl with median cleft of the upper lip, pedunculated skin masses on the nasal septum, short stature, and mental retardation. We describe a new case that presents the main clinical features associated with bifid nose, lipoma, and partial agenesis of corpus callosum.

Holoprosencephaly with neurogenic hypernatremia: a new case.

BACKGROUND: Holoprosencephaly (HPE) is the most common developmental defect of the forebrain and mid-face in humans. It is a disorder of neural induction in which a genetic programming defect results in noncleavage of the forebrain in the sagittal plane and variable hypoplasia of paramedian structures. It occurs in 5-12/10,000 live births. Clinically, there is a nearly continuous spectrum of malformations consistent with HPE. Endocrinopathies, such as diabetes insipidus, hypothyroidism, hypocorticism, and growth hormone deficiency, are frequently associated with HPE. Seizures may occur. CASE REPORT: We report a new case of semilobar-HPE complicated by neurogenic hypernatremia and no signs of dehydration in a child with microcephaly, spasticity, mental and psychomotor retardation, frontal bones hypoplasia, and mild facial dysmorphism.

Fat depot-related differences in gene expression, adiponectin secretion, and insulin action and signalling in human adipocytes differentiated in vitro from precursor stromal cells.

AIM/HYPOTHESIS: The distinct metabolic properties of visceral and subcutaneous adipocytes may be due to inherent characteristics of the cells that are resident in each fat depot. To test this hypothesis, human adipocytes were differentiated in vitro from precursor stromal cells obtained from visceral and subcutaneous fat depots and analysed for genetic, biochemical and metabolic endpoints. METHODS: Stromal cells were isolated from adipose tissue depots of nondiabetic individuals. mRNA levels of adipocyte-specific proteins were determined by real-time RT-PCR. Insulin signalling was evaluated by immunoblotting with specific antibodies. Glucose transport was measured by a 2-deoxy-glucose uptake assay. Adiponectin secretion in the adipocyte-conditioned medium was determined by a specific RIA. RESULTS: With cell differentiation, mRNA levels of PPARG, C/EBPalpha (also known as CEBPA), AP2 (also known as GTF3A), GLUT4 (also known as SLC2A4) were markedly upregulated, whereas GLUT1 (also known as SLC2A1) mRNA did not change. However, expression of C/EBPalpha, AP2 and adiponectin was higher in subcutaneous than in visceral adipocytes. By contrast, adiponectin was secreted at threefold higher rates by visceral than by subcutaneous adipocytes while visceral adipocytes also showed two- to threefold higher insulin-stimulated glucose uptake. Insulin-induced phosphorylation of the insulin receptor, IRS proteins, Akt and extracellular signal-regulated kinase-1/2 was more rapid and tended to decrease at earlier time-points in visceral than in subcutaneous adipocytes. CONCLUSIONS/INTERPRETATION: Subcutaneous and visceral adipocytes, also when differentiated in vitro from precursor stromal cells, retain differences in gene expression, adiponectin secretion, and insulin action and signalling. Thus, the precursor cells that reside in the visceral and subcutaneous fat depots may already possess inherent and specific metabolic characteristics that will be expressed upon completion of the differentiation programme.

[Multiple arterial ischemic strokes in a child with moyamoya disease and Mycoplasma pneumoniae infection]. / Infarti cerebrali multipli in una paziente pediatrica con malattia di moyamoya e infezione da Micoplasma pneumoniae.

Moyamoya disease is a rare disorder characterised by a progressive occlusion or stenosis of the distal portions of bilateral internal carotid arteries with the development of a network of collateral vessels. Pediatric patients show transient ischemic attacks or strokes; diagnosis is made on the basis of clinical and radiographic findings. The case of a 2-year-old female, which after a Mycoplasma pneumoniae infection presented multiple cerebral strokes is reported. A diagnosis of moyamoya disease was made on the basis of neuroradiological findings; neurological complications due to Mycoplasma infection are reported and the relationship between disease and infection are discussed.

Associated hormonal declines in aging: DHEAS.

DHEA and its sulfate prohormone DHEAS are the most abundant circulating adrenal steroid hormones in humans. DHEA exerts its actions on peripheral target tissues either indirectly, following its conversion to androgens, estrogens or both, or directly, as a steroid hormone interacting with either a nuclear or a membrane receptor. In humans, DHEA shows a characteristic pattern of secretion throughout life. Serum DHEA concentrations decline with advancing age and vary with gender, ethnicity, and environmental factors. Epidemiological studies show an inverse relationship between plasma DHEA(S) levels in men and age-related illnesses, including cardiovascular and metabolic diseases, immune disorders, malignancies, and neurological dysfunction. This has generated great interest on the putative role of DHEA in age-associated illnesses. Administration of DHEA to rats and mice reduces visceral fat accumulation, and improves insulin resistance in experimental models of diet-induced obesity and/or Type 2 diabetes. In addition, recent studies in vitro have shown that DHEA has the capacity to improve endothelial function by increasing nitric oxide (NO) synthesis. Replacement of DHEA in patients with adrenal insufficiency has been shown to exert beneficial effects on well-being, mood, and sexuality. By contrast, in healthy individuals, the physiological age-associated decline in circulating DHEA(S) per se does not justify DHEA supplementation, since the effects of this hormone on metabolic abnormalities, endothelial function in vivo, and cardiovascular events are contradictory. However, these results do not exclude the possibility that DHEA treatment may prove beneficial in specific subgroups of elderly subjects.

Effects of streptozocin diabetes and diabetes treatment by islet transplantation on in vivo insulin signaling in rat heart.

The insulin signaling cascade was investigated in rat myocardium in vivo in the presence of streptozocin (STZ)-induced diabetes and after diabetes treatment by islet transplantation under the kidney capsule. The levels of insulin-stimulated tyrosine phosphorylation of the insulin receptor beta-subunit, insulin receptor substrate (IRS)-2, and p52(Shc) were increased in diabetic compared with control heart, whereas tyrosine phosphorylation of IRS-1 was unchanged. The amount of the p85 subunit of phosphatidylinositol 3-kinase (PI 3-kinase) and the level of PI 3-kinase activity associated with IRS-2 were also elevated in diabetes, whereas no changes in IRS-1-associated PI 3-kinase were observed. Insulin-induced phosphorylation of Akt on Thr-308 was increased fivefold in diabetic heart, whereas Akt phosphorylation on Ser-473 was normal. In contrast with Akt phosphorylation, insulin-induced phosphorylation of glycogen synthase kinase (GSK)-3, a major cellular substrate of Akt, was markedly reduced in diabetes. In islet-transplanted rats, the majority of the alterations in insulin-signaling proteins found in diabetic rats were normalized, but insulin stimulation of IRS-2 tyrosine phosphorylation and association with PI 3-kinase was blunted. In conclusion, in the diabetic heart, 1) IRS-1, IRS-2, and p52(Shc) are differently altered, 2) the levels of Akt phosphorylation on Ser-473 and Thr-308, respectively, are not coordinately regulated, and 3) the increased activity of proximal-signaling proteins (i.e., IRS-2 and PI 3-kinase) is not propagated distally to GSK-3. Islet transplantation under the kidney capsule is a potentially effective therapy to correct several diabetes-induced abnormalities of insulin signaling in cardiac muscle but does not restore the responsiveness of all signaling reactions to insulin.

The sentrin-conjugating enzyme mUbc9 interacts with GLUT4 and GLUT1 glucose transporters and regulates transporter levels in skeletal muscle cells.

Glucose transport in insulin-regulated tissues is mediated by the GLUT4 and GLUT1 transporters. Using the yeast two-hybrid system, we have cloned the sentrin-conjugating enzyme mUbc9 as a protein that interacts with the GLUT4 COOH-terminal intracellular domain. The mUbc9 enzyme was found to bind directly to GLUT4 and GLUT1 through an 11-aa sequence common to the two transporters and to modify both transporters covalently by conjugation with the mUbc9 substrate, sentrin. Overexpression of mUbc9 in L6 skeletal muscle cells decreased GLUT1 transporter abundance 65%, resulting in decreased basal glucose transport. By contrast, mUbc9 overexpression increased GLUT4 abundance 8-fold, leading to enhanced transport stimulation by insulin. A dominant-negative mUbc9 mutant lacking catalytic activity had effects opposite to those of wild-type mUbc9. The regulation of GLUT4 and GLUT1 was specific, as evidenced by an absence of mUbc9 interaction with or regulation of the GLUT3 transporter isoform in L6 skeletal muscle cells. The mUbc9 sentrin-conjugating enzyme represents a novel regulator of GLUT1 and GLUT4 protein levels with potential importance as a determinant of basal and insulin-stimulated glucose uptake in normal and pathophysiological states.

[Fetal growth restriction and insulin-like growth factors]. / La restrizione di crescita fetale e i fattori di crescita insulino-simili.

The insulin-like growth factors (IGFs) and their receptors are implicated in pre- and postnatal growth and development. It is believed that the alteration in their activity may contribute to intrauterine growth restriction (IUGR). The aim of this experimental study was to relate some metabolic alterations, involving insulin-like growth factor pathway, in the placenta of pregnancies complicated by intrauterine growth restriction. Placental samples were obtained from six uncomplicated pregnancies and four pregnancies complicated by IUGR. These samples were then stained by immunohistochemical technique, using monoclonal antibodies. Our data have not shown a significant difference in the IR, the Shc isoforms and Akt levels between normal and IUGR placentas. The IUGR placentas had significantly lower levels of IRS-2 expression and higher levels of p85 transcription. IGF-I receptor binds to its ligand and activates two intracellular processes mainly a Shc-mediated pro-mitotic pathway and an anti-apoptotic pathway mediated by IRS and Akt. The diminished activity of one of the two pathways may alter the mitosis/apoptosis balance. Because of the low number of samples and the knowledge about the enzymatic pathways, we have not been able to associate our data to any biological consequence. We can only demonstrate that the enzymatic differences between IUGR and controls tend to the pro-apoptotic processes. It seems to be an other in vivo aspect in favour of the placental role in the IUGR pathogenesis.