Incretin-induced changes in the transcriptome of skeletal muscles of fa/fa Zucker rat (ZFR) with obesity, without diabetes.

INTRODUCTION: Glucagon-like peptide-1 receptor agonists (GLP-1ra) are increasingly used in treating type 2 diabetes and obesity. Exendin-4 (Ex-4), a long acting GLP-1ra, was previously reported to decrease oxidative stress in hepatocytes, adipocytes and skeletal muscle cells in obese nondiabetic fa/fa Zucker rats (ZFR), thereby improving insulin resistance. AIM: We aimed first to identify Ex-4-induced changes in the transcriptome of skeletal muscle cells in ZFR. RESULTS: Ontology analysis of differentially expressed genes (DEGs) in ZFR versus lean animals (LR) showed that the extracellular matrix (ECM) is the first most affected cellular compartment, followed by myofibrils and endoplasmic reticulum (ER). Interestingly, among 15 genes regulated in ZFR versus LR, 14 of them were inversely regulated by Ex-4, as further confirmed by RT-qPCR. Picro-Sirius red histological staining showed that decreased ECM fiber area in ZFR is partially restored by Ex-4. Ontology analysis of the myofibril compartment revealed that decreased muscle contractile function in ZFR is partially restored by Ex-4, as confirmed by Phalloidin histological staining that showed a partial restoration by Ex-4 of altered contractile apparatus in ZFR. Ontology analysis of ER DEGs in ZFR versus LR showed that some of them are related to the AMP-activated protein kinase (AMPK) signaling pathway. Phosphorylated AMPK levels were strongly increased in Ex-4-treated ZFR. CONCLUSION: Altogether, our results suggest that GLP-1ra strongly restructure ECM and reinforce contractile capabilities in ZFR, while optimizing the cellular metabolism through AMPK.

Acute iodine deficiency induces a transient VEGF-dependent microvascular response in mammary glands involving HIF-1, ROS, and mTOR.

Iodine deficiency (ID), which affects almost two billion people worldwide, is associated with breast pathologies such as fibrosis in human and induces breast atypia in animal models. Because ID induces vascular activation in the thyroid, another iodide-uptaking organ, and as breast is also sensitive to ID, we aimed to characterize ID-induced effects on the breast microvasculature in vivo and in two different breast cell lines in vitro. Virgin and lactating NMRI mice received an iodide-deficient diet and a Na+/I- symporter inhibitor for 1 to 20 days. Some virgin mice were treated with vascular endothelial growth factor A (VEGF) or VEGF receptor inhibitors. In vitro, ID was induced in MCF7 and MCF12A cells by replacing the iodide-containing medium by an iodide-deficient medium. In vivo, VEGF expression was increased following ID in mammary tissues. Consequently, ID induced a transient increase in mammary gland blood flow, measured after anesthesia, in virgin and lactating mice, which was repressed by VEGF or VEGF receptor inhibitors. In MCF7 cells, ID induced a transient increase in reactive oxygen species, followed by an increase in hypoxia-inducible factor-1α (HIF-1α) protein and VEGF mRNA expression. Antioxidant N-acetylcysteine and mammalian target of rapamycin (mTOR) inhibitor blocked ID-induced HIF-1α protein increase and VEGF transcription. However, mTOR activity was not inhibited by N-acetylcysteine. Similar responses were observed in MCF12A cells. These data indicate that ID activates the canonical VEGF pathway and mTOR in breast tissues, which provides new insights to better understand the correlation between ID, vascular activation, and breast pathologies.

Emerging Evidence for the Use of Antidiabetic Drugs, Glucagon-like Peptide 1 Receptor Agonists, for the Treatment of Alzheimer's Disease.

From an epidemiological and pathophysiological point of view, Alzheimer's disease (AD) and type 2 diabetes (T2DM) should be considered 'sister' diseases. T2DM significantly increases the risk of developing AD, and the mechanisms of neuronal degeneration themselves worsen peripheral glucose metabolism in multiple ways. The pathophysiological links between the two diseases, particularly cerebral insulin resistance, which causes neuronal degeneration, are so close that AD is sometimes referred to as 'type 3 diabetes'. Although the latest news on the therapeutic front for AD is encouraging, no treatment has been shown to halt disease progression permanently. At best, the treatments slow down the progression; at worst, they are inactive, or cause worrying side effects, preventing their use on a larger scale. Therefore, it appears logical that optimizing the metabolic milieu through preventive or curative measures can also slow down the cerebral degeneration that characterizes AD. Among the different classes of hypoglycaemic drugs, glucagon-like peptide 1 receptor agonists, which are widely used in the treatment of T2DM, were shown to slow down, or even prevent, neuronal degeneration. Data from animal, preclinical, clinical phase II, cohort and large cardiovascular outcomes studies are encouraging. Of course, randomized clinical phase III studies, which are on-going, will be essential to verify this hypothesis. Thus, for once, there is hope for slowing down the neurodegenerative processes associated with diabetes, and that hope is the focus of this review.

Once-weekly 2.4 mg Semaglutide for Weight Management in Obesity: A Game Changer?

The treatment of obesity can no longer be reduced to a simplistic view of weight loss. Metabolic adaptation leads to systematic weight regain following weight-loss efforts, and new obesity treatments should therefore aim to induce long-standing double-digit weight loss, and thus improve and even reverse obesity-associated comorbidities such as type 2 diabetes. Until now, only metabolic surgery has been able to achieve such a goal, but this invasive procedure cannot be offered on a large scale. Among the alternatives, lifestyle interventions and drug therapies have often been disappointing. The recent availability of once-weekly subcutaneous 2.4 mg semaglutide (a glucagon-like peptide-1 receptor agonist; Wegovy™ Novo Nordisk A/S, Bagsværd, Denmark) has changed the scene, and semaglutide is considered a 'game changer' in the treatment of obesity. The results from the phase III STEP (Semaglutide treatment effect in people with obesity) clinical programme have shown that semaglutide provides clinically meaningful and sustained weight loss in ranges much higher than those achieved with previously available pharmacotherapies. These results led to the approval of semaglutide by regulatory authorities as an adjunct to a reduced-calorie diet and increased physical activity in people with obesity or overweight, with at least one weight-related comorbidity. With data from phase II and III clinical trials showing that newer drugs (i.e. the glucagon-like peptide-1 and gastric inhibitory polypeptide dual receptor agonist tirzepatide and the amylin agonist cagrilintide, either alone or combined) produce a greater sustained weight loss than semaglutide, an upstream 'weight-centric' strategy has emerged as a new standard for the treatment of type 2 diabetes.

Oxidative stress: a required condition for thyroid cell proliferation.

Goiter is associated with increased oxidative stress (OS). We studied the effects of an anti-inflammatory agent, 15 deoxy-Delta12,14-prostaglandin J2 (15dPGJ2) and an antioxidant, N-acetylcysteine (NAC), on OS, thyroid function, and goiter expansion in a model of goiter induced by propylthiouracil (PTU) or perchlorate. OS was assessed by the immunodetection of 4-hydroxynonenal, thyroid function by measuring thyroxin (T4) and thyrotropin (TSH) plasma levels and detecting T4-rich thyroglobulin (Tg-I), and goiter expansion by weighing the thyroids and measuring cell proliferation (PCNA and cyclin D1 immunodetection). In both PTU and perchlorate-induced goiters, OS, TSH plasma levels, thyroid weight, and cell proliferation were strongly enhanced, whereas Tg-I expression was negative. All these parameters were reversed by NAC and 15dPGJ2 in PTU-goiters. In perchlorate-goiters, TSH plasma levels remained elevated and Tg-I-negative after NAC or 15dPGJ2 treatment. OS was reduced by NAC, but not by 15dPGJ2. In addition, NAC reduced PCNA and cyclin D1 immunostainings, as well as thyroid weight, whereas 15dPGJ2 influenced neither thyroid weight nor cell proliferation. In conclusion, NAC and 15dPGJ2 overcome PTU- but not perchlorate-induced effects. The retrieval of hormonal synthesis may result from direct chemical interactions between PTU and NAC/15dPGJ2. Although 15dPGJ2 has no effect in perchlorate-goiters, the reduction of OS by NAC is associated with altered goiter development, making OS a required condition for the growth of the thyroid gland.

N-acetylcysteine and 15 deoxy-{delta}12,14-prostaglandin J2 exert a protective effect against autoimmune thyroid destruction in vivo but not against interleukin-1{alpha}/interferon {gamma}-induced inhibitory effects in thyrocytes in vitro.

Reactive oxygen species (ROS) are crucial for thyroid hormonogenesis, and their production is kept under tight control. Oxidative stress (OS) is toxic for thyrocytes in an inflammatory context. In vitro, Th1 pro-inflammatory cytokines have already been shown to decrease thyroid-specific protein expression. In the present study, OS level and its impact on thyroid function were analyzed in vitro in Th1 cytokine (interleukin [IL]-1alpha/interferon [IFN] gamma)-incubated thyrocytes (rat and human), as well as in vivo in thyroids from nonobese diabetic mice, a model of spontaneous autoimmune thyroiditis. N-acetylcysteine (NAC) and prostaglandin, 15 deoxy-(Delta12,14)-prostaglandinJ2 (15dPGJ2), were used for their antioxidant and anti-inflammatory properties, respectively. ROS production and OS were increased in IL-1alpha/IFNgamma-incubated thyrocytes and in destructive thyroiditis. In vitro, NAC not only reduced ROS production below control levels, but further decreased the expression of thyroid-specific proteins in addition to IL-1alpha/IFNgamma-inhibitory effects. Thus, besides ROS, other intracellular intermediaries likely mediate Th1 cytokine effects. In vivo, NAC and 15dPGJ2 reduced OS and the immune infiltration, thereby leading to a restoration of thyroid morphology. It is therefore likely that NAC and 15dPGJ2 mainly exert their protective effects by acting on infiltrating inflammatory cells rather than directly on thyrocytes.

Patient-Reported Outcomes with Insulin Glargine 300 U/mL in People with Type 2 Diabetes: The MAGE Multicenter Observational Study.

INTRODUCTION: MAGE was a Multicenter, single-Arm, observational 6-month (plus 6-month extension) study that aimed to assess treatment satisfaction, efficacy, and safety of insulin Glargine 300 U/mL (Gla-300) in people with type 2 diabetes (T2DM) receiving basal-bolus insulin in a rEal-world setting. MATERIALS AND METHODS: Participants were at least 18 years old, with T2DM for more than 1 year, HbA1c 7.0-10.0%. The primary endpoint was change in Diabetes Treatment Satisfaction Questionnaire status version (DTSQs) total score (baseline to month 6). Secondary endpoints included reasons for starting Gla-300, changes in the DTSQ change version (DTSQc) total score, Hypoglycemia Fear Survey-II (HFS-II) total behavior and worry scores at months 6 and 12, HbA1c changes at months 3, 6, 9, and 12, and safety. RESULTS: MAGE included 87 adults (mean T2DM duration 17 years). The primary endpoint of DTSQs mean (standard deviation) total score improvement at month 6 was achieved (2.80 [5.46] points; p < 0.0001). The main reasons for Gla-300 initiation were to decrease HbA1c (89.7% of participants) and reduce the number of hypoglycemic events (35.6% of participants). Significant improvements were observed in the DTSQc total score and perceived hyperglycemia/hypoglycemia (baseline to month 6, p < 0.05). Significant changes in HFS-II behavior, worry, and total scores at 6 and 12 months were also observed (p < 0.05). There were no statistically significant changes in HbA1c. Safety outcomes, including hypoglycemia, were comparable to previously reported trials. CONCLUSIONS: The MAGE study indicates that Gla-300, as part of a basal-bolus regimen, results in improved treatment satisfaction and reduced hypoglycemia fear in people with advanced T2DM.

Differential interactions between Th1/Th2, Th1/Th3, and Th2/Th3 cytokines in the regulation of thyroperoxidase and dual oxidase expression, and of thyroglobulin secretion in thyrocytes in vitro.

Hypothyroidism, together with glandular atrophy, is the usual outcome of destructive autoimmune thyroiditis. The impairment in the thyroid function results either from cell destruction or from Th1 cytokine-induced alteration in hormonogenesis. Here, we investigated the impact of the local immune context on the thyroid function. We used two rat thyroid cell lines (PCCL3 and FRTL-5) and human thyrocytes incubated with IL-1alpha/interferon (IFN) gamma together with IL-4, a Th2 cytokine, or with TGF-beta, or IL-10, two Th3 cytokines. We first observed that IL-4 totally blocked IL-1alpha/interferon gamma-induced alteration in dual oxidase and thyroperoxidase expression, and in thyroglobulin secretion. By contrast, TGF-beta and IL-10 had no such effect. They rather repressed thyrocyte function as do Th1 cytokines. In addition, IL-4 blocked IL-10-induced repression of thyrocyte function, but not that induced by TGF-beta. In conclusion, Th1 cytokine- and IL-10-induced local inhibitory actions on thyroid function can be totally overturned by Th2 cytokines. These data provide new clues about the influence of the immune context on thyrocyte function.

Oxidative stress in the thyroid gland: from harmlessness to hazard depending on the iodine content.

In basal conditions, thyroid epithelial cells produce moderate amounts of reactive oxygen species (ROS) that are physiologically required for thyroid hormone synthesis. They are not necessarily toxic because they are continuously detoxified either in the process of hormone synthesis or by endogenous antioxidant systems. Using a rat model of goiter formation and iodine-induced involution, we found that compared with control thyroids, the oxidative stress, assessed by the detection of 4-hydroxynonenal, was strongly enhanced both in hyperplastic and involuting glands. The level of antioxidant defenses (glutathione peroxidases and peroxiredoxins) was also up-regulated in both groups, although somewhat less in the latter. Of note, increased oxidative stress came along with an inflammatory reaction, but only in involuting glands, suggesting that although antioxidant systems can adequately buffer a heavy load of ROS in goiter, it is not necessarily the case in involuting glands. The effects of 15-deoxy-Delta(12,14)-prostaglandin J2 (15dPGJ2), an endogenous ligand of peroxisome proliferated-activated receptor gamma (PPARgamma) with antiinflammatory properties, were then investigated in involuting glands. This drug strongly reduced both 4-hydroxynonenal staining and the inflammatory reaction, indicating that it can block iodine-induced cytotoxicity. When experiments were carried out with the PPARgamma antagonist, bisphenol A diglycidyl ether, 15dPGJ2-induced effects remained unchanged, suggesting that these effects were not mediated by PPARgamma. In conclusion, thyroid epithelial cells are well adapted to endogenously produced ROS in basal and goitrous conditions. In iodine-induced goiter involution, the increased oxidative stress is accompanied by inflammation that can be blocked by 15dPGJ2 through PPARgamma-independent protective effects.

The new FreeStyle libre flash glucose monitoring system improves the glycaemic control in a cohort of people with type 1 diabetes followed in real-life conditions over a period of one year.

AIMS: Using the novel FreeStyle Libre (FSL), glucose monitoring (FGM) system becomes increasingly popular among people with type 1 diabetes (T1D) and is associated with less and shorter hypoglycaemic events without deterioration of HbA1c. There are not yet data reporting the impact of FGM in people with T1D in real-life conditions. We sought of evaluating the tolerance, the acceptance and the efficacy of the FGM system in routine medical practice. METHODS: This 12-month observational study included 120 individuals with T1D evaluated every 3 months. After having been instructed about FGM utilization, participants were trained to optimize the glycaemic control. RESULTS: Participants stopped immediately of measuring capillary blood glucose (2.88 ± 0.12 per day) (mean ± SEM) after having received the first FSL device and the number of scans per day increased up to 8.87 ± 0.58 per day. HbA1c levels decreased from 8.51% ± 0.14% at baseline to 7.77% ± 0.09% after 3 months to slightly increase to 7.92% ± 0.09% at 12 months, in correlation with the number of scans per day. The number (but not the duration) of hypoglycaemic events slightly increased from 16.9 ± 1.44 per month at baseline to 24.0 ± 2.91 per month at 12 months, after reaching a peak of 26.4 ± 2.31 per month at 6 months. They were correlated with improved HbA1c. CONCLUSION: Our study shows that using the FGM system improves HbA1c levels in people with T1D along with a moderate increase in the number of mild hypoglycaemic events. The new FGM system facilitates the therapeutic empowerment of people with T1D, but in a context of structured education.

Time course of tissue remodelling and electrophysiology in the rat sciatic nerve after spiral cuff electrode implantation.

Implantation of nerve cuff electrodes induces inflammatory cell infiltration and loose connective tissue accumulation. Along with time, morphological changes evolve towards a thicker epi/perineurium as part of mechanisms that protect nerve functionality when a foreign body is wrapped around it. The rise in electrode impedance is linked to the nature of the epineurial tissue. Changes involve an increased expression of neuroprotective factors that is stronger in the endoneurium with axonal degeneration. Our data indicate that epineurial and endoneurial changes after electrode cuff implantation are part of axonal protection mechanisms. Their control is important to improve the yield of FES applications.

Iodine deficiency induces a VEGF-dependent microvascular response in salivary glands and in the stomach.

Despite efforts to optimize iodine supply in iodine deficient countries, iodine deficiency (ID) remains a global problem worldwide. Activation of the local microvasculature by ID in the thyroid gland aims at improving the local supply of iodide. For this purpose, the thyrocytes secrete vascular endothelial growth factor (VEGF) that acts on adjacent capillaries, via a reactive oxygen species (ROS)/Hypoxia Inducible factor (HIF)-dependent pathway. Beside the thyroid, other organs including salivary glands and the stomach do express the sodium/iodide symporter (NIS) and are able to take iodide up, potentially rendering them sensitive to ID. To verify this hypothesis, ID-induced effects on the local microvasculature were studied in salivary glands and in the stomach. ID was induced by feeding young mice with an iodide-deficient diet and NIS inhibitor perchlorate in the drinking water. In salivary glands, ID induced a transient increase in HIF-1α protein expression accompanied by a transient, VEGF-dependent increase in blood flow. In the gastric mucosa, ID transiently increased VEGF expression in the mucin-secreting epithelium and in ghrelin-secreting endocrine cells. These observations suggest that microvascular changes in response to ID occur in NIS-expressing tissues other than the thyroid. NIS expressing cells could be viewed as iodide sensors that respond to ID by inducing vascular changes, probably to optimize iodide bioavailability at regional or systemic levels.

Extrapancreatic effects of incretin hormones: evidence for weight-independent changes in morphological aspects and oxidative status in insulin-sensitive organs of the obese nondiabetic Zucker rat (ZFR).

Incretin-based therapies are widely used to treat type 2 diabetes. Although hypoglycemic actions of incretins are mostly due to their insulinotropic/glucagonostatic effects, they may also influence extrapancreatic metabolism. We administered exendin-4 (Ex-4), a long-acting glucagon-like peptide receptor agonist, at low dose (0.1 nmol/kg/day) for a short period (10 days), in obese nondiabetic fa/fa Zucker rats (ZFRs). Ex-4-treated ZFRs were compared to vehicle (saline)-treated ZFRs and vehicle- and Ex-4-treated lean rats (LRs). Blood glucose levels were measured at days 0, 9, and 10. Ingested food and animal weight were recorded daily. On the day of sacrifice (d10), blood was sampled along with liver, epididymal, subcutaneous, brown adipose, and skeletal muscle tissues from animals fasted for 24 h. Plasma insulin and blood glucose levels, food intake, and body and epididymal fat weight were unchanged, but gross morphological changes were observed in insulin-sensitive tissues. The average size of hepatocytes was significantly lower in Ex-4-treated ZFRs, associated with decreased number and size of lipid droplets and 4-hydroxy-2-nonenal (HNE) staining, a marker of oxidative stress (OS). Myocytes, which were smaller in ZFRs than in LRs, were significantly enlarged and depleted of lipid droplets in Ex-4-treated ZFRs. Weak HNE staining was increased by Ex-4. A similar observation was made in brown adipose tissue, whereas the elevated HNE staining observed in epididymal adipocytes of ZFRs, suggestive of strong OS, was decreased by Ex-4. These results suggest that incretins by acting on OS in insulin-sensitive tissues may contribute to weight-independent improvement in insulin sensitivity.

Anti-TNF-alpha reduces the inflammatory reaction associated with cuff electrode implantation around the sciatic nerve.

Extraneural cuff electrodes have been extensively used to investigate the nervous system. Their implantation is, however, associated with epineurial fibrosis, fiber loss, limited reproducibility of recordings and variability in stimulating conditions. It has recently been shown that TNF-alpha is involved in nerve alterations after electrode implantation. This study investigated whether a peri-operative anti-TNF-alpha treatment could modify the inflammation and fibrosis associated with cuff electrode implantation. Morphometrical and immunohistochemical methods were used to show that a single systemic injection of TNF-alpha neutralizing antibodies is sufficient to reduce the early inflammatory events, but not the long lasting fibrotic reaction.

Nitric oxide synthases II and III and vascular endothelial growth factor are up-regulated in sciatic nerve after spiral cuff electrode implantation.

Nerve cuff electrodes, commonly used in functional electrical stimulation systems, induce local morphological changes that can affect nerve functionality. Nitric oxide (NO) and vascular endothelial growth factor (VEGF) have both neural and vascular effects. We investigated the time-dependent regulation of nitric oxide synthases (NOS) and of VEGF after implantation of spiral cuff electrode around rat sciatic nerve. NOSIII as well as VEGF were up-regulated in both epineurial and endoneurial compartments in cuff-implanted animals along with microvascular changes. Our results suggest that VEGF and NO are implied in morphological and functional alterations occurring in the early time after cuff implantation.

Cuff electrode implantation around the sciatic nerve is associated with an upregulation of TNF-alpha and TGF-beta 1.

Epineurial fibrosis, fiber loss, limited reproducibility of recordings and variability of stimulation conditions have been documented after extraneural cuff electrode implantation. These morphological and electrophysiological modifications could be due to the local release of cytokines. We report the expression of two cytokines, tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta1 (TGF-beta1) in the rat sciatic nerve after 'cuff' implantation for 18 h, 7 days and 1 month. Immunohistochemical and Western blot analyses showed a transient upregulation of TNF-alpha, during the first week, and a prolonged increase of TGF-beta1, over the 1-month period duration of this study. Considering the known pro-inflammatory roles of TNF-alpha and the pro-fibrotic action of TGF-beta, our results strongly suggest that these cytokines may contribute to nerve alterations occurring within the acute and sub-acute phases after cuff electrode implantation.

Differential regulation of the production of reactive oxygen species in Th1 cytokine-treated thyroid cells.

BACKGROUND: Th1 cytokines exert pleiotropic effects in Hashimoto's thyroiditis. Previous studies reported a downregulation of thyroperoxidase and dual oxidase (DUOX) protein and mRNA expression in thyroid cells treated with Th1 cytokines. Although this effect is partially mediated by intracellular reactive oxygen species (ROS) and reactive nitrogen species, the nature and the source of the ROS involved are currently unknown. The aim of this study was to examine further the nature and source of the ROS produced in response to Th1 cytokines. METHODS: Two rat thyroid cell lines (PCCL3 and FRTL-5) and human thyrocytes were incubated with Th1 cytokines (interleukin [IL]-1α and interferon-γ) in the presence or absence of the Th2 cytokine IL-4, the nitric oxide synthase inhibitor N-nitroso-L-arginine methyl ester (L-NAME), or the synthetic antioxidant N-acetylcysteine. The nature and source of the intracellular and extracellular ROS produced were determined. RESULTS: A rapid increase in intracellular ROS was observed in cells incubated with Th1 cytokines. This increase was not caused by extracellular hydrogen peroxide (H2O2) produced by DUOX because both DUOX expression and extracellular H2O2 synthesis were decreased by Th1 cytokines. Confocal colocalization experiments showed that the Th1 cytokine-triggered ROS were not produced from mitochondria. Electron paramagnetic resonance investigations of PCCL3 cells indicated that the highly reactive hydroxyl radical was not involved in the response to Th1 cytokines. NOX2 mRNA expression was significantly increased in PCCL3 cells incubated with Th1 cytokines, as was the expression of the protein in the thyroid of Hashimoto's thyroiditis patients. NOX4 expression was by contrast unaffected. These results suggest that at least superoxide could be produced after exposure of thyroid cells to Th1 cytokines. The effects of L-NAME and IL-4, both of which partially or totally reverse Th1 cytokine-induced effects, on ROS release were also analyzed. L-NAME and IL-4 significantly reduced the Th1 cytokine-induced surge of intracellular ROS in PCCL3 and human thyroid cells. CONCLUSION: The data presented here reinforce the idea that ROS, other than extracellular H2O2 produced by DUOX, are released from NOX2 after exposure of thyroid cells to Th1 cytokines. ROS/reactive nitrogen species act as important, but as further explained, not exclusive intracellular mediators of Th1 cytokine-induced effects in thyroid cells.

The expression of dual oxidase, thyroid peroxidase, and caveolin-1 differs according to the type of immune response (TH1/TH2) involved in thyroid autoimmune disorders.

CONTEXT: Hashimoto's thyroiditis (HT) and Graves' disease (GD) are thyroid autoimmune disorders driven by Th1 and Th2 immune responses, respectively. Caveolin-1 (Cav-1), thyroid peroxidase (TPO), and dual oxidase (DUOX) are thought to be part of the thyroxisome, which is essential to maintain thyroid hormone synthesis, at the apical membrane. OBJECTIVES: To analyze the thyroxisome in HT and GD thyroids, we investigated Cav-1, DUOX, and TPO expression as well as markers of oxidative stress (OS), cell proliferation, apoptosis, and antioxidant defenses. The effects of cytokines on Cav-1 expression were analyzed in vitro. RESULTS: In HT, the decrease in Cav-1, DUOX, and TPO expression was marked in follicles having the morphological aspect of active follicles in normal glands and thus called active-like follicles. T4 was not detected in the colloid but in the cytoplasm as well as DUOX and TPO. These abnormalities were associated with increased OS and cell damage. In the hypofunctioning follicles of HT and normal thyroids, Cav-1, DUOX, and TPO were not expressed. In GD, they were expressed at the apical pole of thyrocytes, and T4 accumulated in the colloid of all follicles. Th1 cytokines IL-1α/interferonγ decreased Cav-1 expression in vitro, whereas the Th2 cytokine IL-4 had no effect. CONCLUSION: Th1 cytokine-induced down-regulation of Cav-1 could be responsible for intracytoplasmic T4 synthesis and mislocalization of DUOX and TPO, suggesting an important role for Cav-1 in the preservation of thyroxisome integrity. The thyroxisome's disruption, leading to uncontrolled OS and cell apoptosis, is a key, event in HT pathogenesis.

Glucose meters with built-in automated bolus calculator: gadget or real value for insulin-treated diabetic patients?

Self-monitoring of blood glucose is now widely recognized as efficacious to enhance and facilitate diabetes management. More than just a means of recording and storing data, some blood glucose meters (BGMs) are now designed with an embedded automated bolus calculator (ABC) with the goal to propose patients recommendations about insulin dosage. The growing literature in this field tends to claim that these new smart BGMs make patient's life easier and decision making safer. The main purpose of this review is to verify whether BGMs with a built-in ABC indeed improve the willingness and the ability of insulin-treated patients to make adequate therapeutic decisions and positively impact the metabolic control and the quality of life of ABC users. It appears that, as long as the education provided by caregivers remains a top priority, BGMs with a built-in ABC (more than just electronic gadgets) can be regarded as bringing real value to insulin-treated patients with diabetes.

Recent insights into the cell biology of thyroid angiofollicular units.

In thyrocytes, cell polarity is of crucial importance for proper thyroid function. Many intrinsic mechanisms of self-regulation control how the key players involved in thyroid hormone (TH) biosynthesis interact in apical microvilli, so that hazardous biochemical processes may occur without detriment to the cell. In some pathological conditions, this enzymatic complex is disrupted, with some components abnormally activated into the cytoplasm, which can lead to further morphological and functional breakdown. When iodine intake is altered, autoregulatory mechanisms outside the thyrocytes are activated. They involve adjacent capillaries that, together with thyrocytes, form the angiofollicular units (AFUs) that can be considered as the functional and morphological units of the thyroid. In response to iodine shortage, a rapid expansion of the microvasculature occurs, which, in addition to nutrients and oxygen, optimizes iodide supply. These changes are triggered by angiogenic signals released from thyrocytes via a reactive oxygen species/hypoxia-inducible factor/vascular endothelial growth factor pathway. When intra- and extrathyrocyte autoregulation fails, other forms of adaptation arise, such as euthyroid goiters. From onset, goiters are morphologically and functionally heterogeneous due to the polyclonal nature of the cells, with nodules distributed around areas of quiescent AFUs containing globules of compact thyroglobulin (Tg) and surrounded by a hypotrophic microvasculature. Upon TSH stimulation, quiescent AFUs are activated with Tg globules undergoing fragmentation into soluble Tg, proteins involved in TH biosynthesis being expressed and the local microvascular network extending. Over time and depending on physiological needs, AFUs may undergo repetitive phases of high, moderate, or low cell and tissue activity, which may ultimately culminate in multinodular goiters.