A long non-coding RNA that harbors a SNP associated with type 2 diabetes regulates the expression of TGM2 gene in pancreatic beta cells

INTRODUCTION

Most of the disease-associated single nucleotide polymorphisms (SNPs) lie in non- coding regions of the human genome. Many of these variants have been predicted to impact the expression and function of long non-coding RNAs (lncRNA), but the contribution of these molecules to the development of complex diseases remains to be clarified.

METHODS

Here, we performed a genetic association study between a SNP located in a lncRNA known as LncTGM2 and the risk of developing type 2 diabetes (T2D), and analyzed its implication in disease pathogenesis at pancreatic beta cell level. Genetic association study was performed on human samples linking the rs2076380 polymorphism with T2D and glycemic traits. The pancreatic beta cell line EndoC-bH1 was employed for functional studies based on LncTGM2 silencing and overexpression experiments. Human pancreatic islets were used for eQTL analysis.

RESULTS

We have identified a genetic association between LncTGM2 and T2D risk. Functional characterization of the LncTGM2 revealed its implication in the transcriptional regulation of TGM2, coding for a transglutaminase. The T2Dassociated risk allele in LncTGM2 disrupts the secondary structure of this lncRNA, affecting its stability and the expression of TGM2 in pancreatic beta cells. Diminished LncTGM2 in human beta cells impairs glucose-stimulated insulin release.

CONCLUSIONS

These findings provide novel information on the molecular mechanisms by which T2D-associated SNPs in lncRNAs may contribute to disease, paving the way for the development of new therapies based on the modulation of lncRNAs.

Ageing Effects on a Softened Bitumen by the Addition of DSA (Dodecenyl Succinic Anhydride)

The softening of aged bitumen is necessary for a successful asphalt rejuvenation in road recycling operations. Thus, this study proposes a novel and successful approach by using Dodecenyl Succinic Anhydride (DSA), a reactive surfactant with a polar head capable of reacting with some polar compounds of bitumen. On this basis, this paper analyses the softening potential and ageing inhibition capability of the addition of 3 wt.% DSA before and after the application of standard laboratory ageing methods (rolling thin film oven, RTFOT and pressure aging vessel (PAV) tests). To that end, different modified bitumens were evaluated by analysing the linear viscoelastic behaviour, viscous flow properties, thin layer chromatography, Fourier transform infrared spectroscopy (FTIR), contact angle measurements and compactibility tests. The results obtained for DSA show its greater potential to soften a model bitumen, when compared to a diluent oil, through physico-chemical processes that bring about a lowering in the polarity along with the alteration of its colloidal stability. Even though ageing processes in bitumen negatively affect its softening capacity, the developed structures still retain the ability to partially compensate for the adverse hardening effects. Furthermore, DSA addition greatly enhances the binder’s wettability on a siliceous-type aggregate and favours asphalt compaction.

Sensorimotor effects of plasticity-inducing percutaneous peripheral nerve stimulation protocols

BACKGROUND

Electrical stimulation of skin afferents can induce somatosensory plasticity in humans. Nevertheless, it is unknown if this is possible to do through percutaneous stimulation of a peripheral nerve, which will allow for regional anaesthesia interventions. Furthermore, potentiation protocols applied over mainly non-nociceptive fibers inhibit nociception in rodents, but this has not been tested in humans.

OBJECTIVE

to determine whether a protocol aiming to depress the nociceptive circuit and another aiming to potentiate non-nociceptive circuits produce regional hypoalgesia and changes in motor function, applied through percutaneous peripheral nerve stimulation (pPNS), and to assess which of them is more promising for pain relief, immediately and 24 hours after intervention.

METHODS

PT-cLF protocol aims to depress the nociceptive pathway through Pain Threshold, continuous Low Frequency stimulation and ST-bHF aims to produce potentiation of the non-nociceptive pathway, through Sensory Threshold burst stimulation at High Frequency. All subjects (n=29) went through both protocols and a control condition in a randomized and blinded crossover design.

RESULTS

Compared to control, ST-bHF induced distal hypoalgesia, towards electrical (p=0.04) and mechanical stimuli (p=0.02) and produced mechanical hypoesthesia (p=0.02). Contrarily, hypoalgesia was not observed after PT-cLF (p>0.05) but increased electrical motor threshold (p=0.04), reduced motor recruitment (p=0.03), and the subjects reported feeling reduced strength (p<0.01).

CONCLUSION

This works provides evidence that is possible to induce antinociceptive plasticity in a wide territory using pPNS. Moreover, it demonstrates for the first time in humans that a protocol aiming to produce long-term potentiation applied predominantly over non-nociceptive afferents induces hypoesthesia and hypoalgesia.

Comparison of Outcomes between Obese and Nonobese Patients in Laparoscopic Adrenalectomy: A Cohort Study

INTRODUCTION

Obesity is usually considered a risk factor for surgical complications. Laparoscopic adrenalectomy has replaced open adrenalectomy as the standard operation for adrenal tumors.

OBJECTIVE

To compare the safety of laparoscopic adrenalectomy to treat adrenal tumors in obese versus nonobese patients.

METHODS

This observational cohort study analyzed consecutive patients who underwent laparoscopic adrenalectomy with a lateral transperitoneal approach at a single center (2003-2020). Data and outcomes of obese (body mass index ≥30 kg/m2) and nonobese patients were compared. To analyze the association between operative time and other variables, we used simple and multivariate linear regression.

RESULTS

N = 160 (90 obese/70 nonobese) patients underwent laparoscopic adrenalectomy. Cushing syndrome and pheochromocytoma were the most frequent indications. Obese patients were older (58 vs. 52 years, p < 0.001). A greater proportion of obese patients were ASA grade III + IV (71.1 vs. 48.6%, p = 0.004). Obesity was associated with a longer operative time (72.5 vs. 60 min, p < 0.001) and greater blood loss (40 vs. 20 mL, p = 0.022). There were no differences in conversion, morbidity, or hospital stay. After adjustment for confounding factors, operative time was positively correlated with BMI ≥30 kg/m2, learning curve, estimated blood loss, 2D laparoscopy, and specimen size.

CONCLUSION

Lateral transperitoneal laparoscopic adrenalectomy is safe in patients with a BMI 30-35 kg/m2, so these patients also benefit from this minimally invasive surgery.

Analysis of miRNA signatures in CSF identifies upregulation of miR-21 and miR-146a/b in patients with multiple sclerosis and active lesions

BACKGROUND

MicroRNAs (miRNAs) have been reported as deregulated in active brain lesions derived from patients with multiple sclerosis (MS). In there, these post-transcriptional regulators may elicit very important effects but proper identification of miRNA candidates as potential biomarkers and/or therapeutic targets is scarcely available.

OBJECTIVE

The aim of the study was to detect the presence of a set of candidate miRNAs in cell-free cerebrospinal fluid (CSF) and to determine their association with gadolinium-enhancing (Gd+) lesions in order to assess their value as biomarkers of MS activity.

METHODS

Assessment of 28 miRNA candidates in cell-free CSF collected from 46 patients with MS (26 Gd+ and 20 Gd- patients) was performed by TaqMan assays and qPCR. Variations in their relative abundance were analyzed by the Mann-Whitney U test and further evaluated by receiver operating characteristic (ROC) analysis. Signaling pathways and biological functions of miRNAs were analyzed using bioinformatic tools (miRTarBase, Enrichr, REVIGO, and Cytoscape softwares).

RESULTS

Seven out of 28 miRNA candidates were detected in at least 75% of CSF samples. Consistent increase of miR-21 and miR-146a/b was found in Gd+ MS patients. This increase was in parallel to the number of Gd+ lesions and neurofilament light chain (NF-L) levels. Gene Ontology enrichment analysis revealed that the target genes of these miRNAs are involved in biological processes of key relevance such as apoptosis, cell migration and proliferation, and in cytokine-mediated signaling pathways.

CONCLUSION

Levels of miR-21 and miR-146a/b in cell-free CSF may represent valuable biomarkers to identify patients with active MS lesions.

Deletion of iRhom2 protects against diet-induced obesity by increasing thermogenesis

Objective

Obesity is the result of positive energy balance. It can be caused by excessive energy consumption but also by decreased energy dissipation, which occurs under several conditions including when the development or activation of brown adipose tissue (BAT) is impaired. Here we evaluated whether iRhom2, the essential cofactor for the Tumour Necrosis Factor (TNF) sheddase ADAM17/TACE, plays a role in the pathophysiology of metabolic syndrome.

Methods

We challenged WT versus iRhom2 KO mice to positive energy balance by chronic exposure to a high fat diet and then compared their metabolic phenotypes. We also carried out ex vivo assays with primary and immortalized mouse brown adipocytes to establish the autonomy of the effect of loss of iRhom2 on thermogenesis and respiration.

Results

Deletion of iRhom2 protected mice from weight gain, dyslipidemia, adipose tissue inflammation, and hepatic steatosis and improved insulin sensitivity when challenged by a high fat diet. Crucially, the loss of iRhom2 promotes thermogenesis via BAT activation and beige adipocyte recruitment, enabling iRhom2 KO mice to dissipate excess energy more efficiently than WT animals. This effect on enhanced thermogenesis is cell-autonomous in brown adipocytes as iRhom2 KOs exhibit elevated UCP1 levels and increased mitochondrial proton leak.

Conclusion

Our data suggest that iRhom2 is a negative regulator of thermogenesis and plays a role in the control of adipose tissue homeostasis during metabolic disease.

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Deletion of iRhom2 protects mice from metabolic syndrome.

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In obesity, iRhom2 deletion increases energy expenditure, thermogenesis and white adipose tissue beiging.

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iRhom2 deletion enhances thermogenesis in naïve brown adipocytes.

Ageing influences the relationship of circulating miR-33a and miR- 33b levels with insulin resistance and adiposity

OBJECTIVE

The identification of circulating microRNAs related to abnormal metabolic function may be useful in the context of ageing, adiposity and insulin resistance. The miR-33 a/b has been shown to control the expression of genes involved in fatty acid biosynthesis, impaired metabolism and insulin resistance. In this study, we aimed to identify differences in circulating miR-33 a/b levels according to age-related metabolic impairment and increased adiposity.

METHODS

This study included 80 individuals (30.2% with obesity, 70% females) classified according to insulin resistance (Stern's criteria) and age [young (20-39 years) and senior (40-59 years)]. Body fat was evaluated using bioelectrical impedance, biochemical markers by colorimetric, enzymatic and immuno-turbidimetry methods. TaqMan measures of circulating miR-33 a and miR-33 b with quantitative reverse transcription polymerase chain reaction in serum were assessed in association with clinical outputs.

RESULTS

Circulating miR-33 a and miR-33 b levels showed significant association with fatness, the lipid profile and biomarkers of impaired glucose metabolism. Both miR-33 a and miR-33 b were associated with visceral adiposity index in non-insulin resistance and insulin resistance individuals. More important, for miR-33 a circulating levels in senior group, receiver operating characteristic curve analyses showed area under the curve 0.804 ( p = 0.010; 95% confidence interval = 0.655-0.952).

CONCLUSION

Ageing influenced the relationship of circulating miR-33 a and miR-33 b with insulin resistance and increased adiposity.

Modulation of SHBG binding to testosterone and estradiol by sex and morbid obesity

OBJECTIVE

Sex hormone-binding globulin (SHBG) binds and transports testosterone and estradiol in plasma. The possibility that SHBG is a mixture of transporting proteins has been postulated. We analyzed in parallel the effects of obesity status on the levels and binding capacity of circulating SHBG and their relationship with testosterone and estradiol.

DESIGN

Anthropometric measures and plasma were obtained from apparently healthy young (i.e. 35 ± 7 years) premenopausal women (n = 32) and men (n = 30), with normal weight and obesity (BMI >30 kg/m²).

METHODS

SHBG protein (Western blot), as well as the plasma levels of testosterone, estradiol, cortisol and insulin (ELISA) were measured. Specific binding of estradiol and testosterone to plasma SHBG was analyzed using tritium-labeled hormones.

RESULTS

Significant differences in SHBG were observed within the obesity status and gender, with discordant patterns of change in testosterone and estradiol. In men, testosterone occupied most of the binding sites. Estrogen binding was much lower in all subjects. Lower SHBG of morbidly obese (BMI >40 kg/m²) subjects affected testosterone but not estradiol. The ratio of binding sites to SHBG protein levels was constant for testosterone, but not for estradiol. The influence of gender was maximal in morbid obesity, with men showing the highest binding/SHBG ratios.

CONCLUSIONS

The results reported here are compatible with SHBG being a mixture of at least two functionally different hormone-binding globulins, being affected by obesity and gender and showing different structure, affinities for testosterone and estradiol and also different immunoreactivity.

Decreased lipid metabolism but increased FA biosynthesis are coupled with changes in liver microRNAs in obese subjects with NAFLD

BACKGROUND/OBJECTIVE

Many controversies regarding the association of liver miRNAs with obesity and nonalcoholic fatty liver diseases (NAFLD) call for additional validations. This study sought to investigate variations in genes and hepatic miRNAs in a sample of obese patients with or without NAFLD and human hepatocytes (HH).

SUBJECTS/METHODS

A total of 60 non-consecutive obese women following bariatric surgery were recruited. Subjects were classified as NAFLD (n=17), borderline (n=24) and controls (n=19) with normal enzymatic profile, liver histology and ultrasound assessments. Profiling of 744 miRNAs was performed in 8 obese women with no sign of hepatic disease and 11 NAFLD patients. Additional validation and expression of genes related to de novo fatty acid (FA) biosynthesis, uptake, transport and β-oxidation; glucose metabolism, and inflammation was tested in the extended sample. Induction of NAFLD-related genes and miRNAs was examined in HepG2 cells and primary HH treated with palmitic acid (PA), a combination of palmitate and oleic acid, or high glucose, and insulin (HG) mimicking insulin resistance in NAFLD.

RESULTS

In the discovery sample, 14 miRNAs were associated with NAFLD. Analyses in the extended sample confirmed decreased miR-139-5p, miR-30b-5p, miR-122-5p and miR-422a, and increased miR-146b-5p in obese subjects with NAFLD. Multiple linear regression analyses disclosed that NAFLD contributed independently to explain miR-139-5p (P=0.005), miR-30b-5p (P=0.005), miR-122-5p (P=0.021), miR-422a (P=0.007) and miR-146a (P=0.033) expression variance after controlling for confounders. Decreased miR-122-5p in liver was associated with impaired FA usage. Expression of inflammatory and macrophage-related genes was opposite to decreased miR-30b-5p, miR-139-5p and miR-422a, whereas increased miR-146b-5p was associated with FABP4 and decreased glucose metabolism and FA mobilization. In partial agreement, PA (but not HG) led to decreased miR-139-5p, miR-30b-5p, miR-422a and miR-146a in vitro, in parallel with increased lipogenesis and FA transport, decreased glucose metabolism and diminished FA oxidation.

CONCLUSION

This study confirms decreased liver glucose and lipid metabolism but increased FA biosynthesis coupled with changes in five unique miRNAs in obese patients with NAFLD.

miRNAs in cerebrospinal fluid identify patients with MS and specifically those with lipid-specific oligoclonal IgM bands

BACKGROUND

MicroRNAs (miRNAs) are non-coding RNAs that regulate cellular processes by controlling protein translation and mRNA degradation.

OBJECTIVE

We aimed to explore the miRNA signature of multiple sclerosis (MS) patients versus controls and the possibility that patients with lipid-specific oligolconal IgM bands (LS_OCMB), a predictor of a more severe disease course, may have a distinct profile.

METHODS

An extensive profile of 754 miRNAs was evaluated in the cerebrospinal fluid (CSF) of 14 women using TaqMan low-density arrays. Differentially expressed miRNAs together with others previously identified in the literature were validated in an extended sample of 86 MS patients (39 LS_OCMB+) and 55 controls.

RESULTS

We detected higher levels of miR-150 in MS patients and especially in those with LS_OCMB+. Other miRNAs (miR-328, miR-30a-5p and miR-645) were up-regulated in MS patients compared to controls while miR-21, miR-199a-3p, miR-191, miR-365, miR-106a and miR-146a showed down-regulated expression. Considering only patients with LS_OCMB+, we also detected up-regulation of miR-30a-5p, miR-150 and miR-645 and down-regulation of miR-191 compared to controls.

CONCLUSION

Our study confirms the recent findings regarding the deregulated expression of miR-150 not only with MS but also with the presence of LS_OCMB. This study highlights the potential utility of miRNAs in CSF as biomarkers for MS.

Diazoxide enhances excitotoxicity-induced neurogenesis and attenuates neurodegeneration in the rat non-neurogenic hippocampus

Diazoxide, a well-known mitochondrial KATP channel opener with neuroprotective effects, has been proposed for the effective and safe treatment of neuroinflammation. To test whether diazoxide affects the neurogenesis associated with excitotoxicity in brain injury, we induced lesions by injecting excitotoxic N-methyl-d-aspartate (NMDA) into the rat hippocampus and analyzed the effects of a daily oral administration of diazoxide on the induced lesion. Specific glial and neuronal staining showed that NMDA elicited a strong glial reaction associated with progressive neuronal loss in the whole hippocampal formation. Doublecortin immunohistochemistry and bromo-deoxyuridine (BrdU)-NeuN double immunohistochemistry revealed that NMDA also induced cell proliferation and neurogenesis in the lesioned non-neurogenic hippocampus. Furthermore, glial fibrillary acidic protein (GFAP)-positive cells in the injured hippocampus expressed transcription factor Sp8 indicating that the excitotoxic lesion elicited the migration of progenitors from the subventricular zone and/or the reprograming of reactive astrocytes. Diazoxide treatment attenuated the NMDA-induced hippocampal injury in rats, as demonstrated by decreases in the size of the lesion, neuronal loss and microglial reaction. Diazoxide also increased the number of BrdU/NeuN double-stained cells and elevated the number of Sp8-positive cells in the lesioned hippocampus. These results indicate a role for KATP channel activation in regulating excitotoxicity-induced neurogenesis in brain injury.

Inflammation triggers specific microRNA profiles in human adipocytes and macrophages and in their supernatants

Background

The relevance of microRNAs (miRNAs) in adipose tissue is increasingly recognized, being intrinsically linked to different pathways, including obesity-related inflammation. In this study, we aimed to characterize the changes induced by inflammation on the miRNA pattern of human adipocytes and macrophages. Therefore, an extensive profile of 754 common miRNAs was assessed in cells (human primary mature adipocytes, and the macrophage-like cell line THP-1) and in their supernatants (SN) using TaqMan low-density arrays. These profiles were evaluated at the baseline and after administration of lipopolysaccharide (LPS, 10 ng/ml) and LPS-conditioned medium from M1 macrophages (MCM, 5%). The miRNAs that experienced the most dramatic changes were studied in subcutaneous human adipose tissue before and approximately 2 years after bariatric surgery-induced weight loss.

Results

Differentiated adipocytes expressed 169 miRNAs, being 85 detectable in the SN. In M1 macrophages, 183 miRNAs were detected, being 106 also present in the SN. Inflammation led to an increased number of miRNAs detectable in cells and in their SNs in both adipocytes (+8.3% and +24.7%) and M1 macrophages (+1.4% and +5%, respectively). Indeed, under inflammatory conditions, adipocytes and M1 macrophages shared the expression of 147 (+9%) miRNAs, and 100 (+41%) common miRNAs were found in their SNs. Twelve of these factors were also linked to inflammation in whole adipose tissue from obese subjects. Interestingly, miR-221 (2-fold, P = 0.002), miR-222 (2.5-fold, P = 0.04), and miR-155 (5-fold, P = 0.015) were increased in inflamed adipocytes and in their SNs (15-, 6-, and 4-fold, respectively, all P < 0.001). Furthermore, their expressions in human adipose tissue concordantly decreased after weight loss (−51%, P = 0.003, −49%, P = 0.03, and −54.4%, P = 0.005, respectively).

Conclusions

Inflammation induces a specific miRNA pattern in adipocytes and M1 macrophages, with impact on the physiopathology of obesity-induced inflammation of adipose tissue. The crosstalk between cells should be investigated further.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0083-3) contains supplementary material, which is available to authorized users.

Adipose tissue μ-crystallin is a thyroid hormone-binding protein associated with systemic insulin sensitivity

BACKGROUND

Circulating thyroid hormones have been described to be intrinsically associated with insulin sensitivity in healthy subjects. μ-Crystallin is a nicotinamide adenine dinucleotide phosphate-dependent thyroid hormone-binding protein that has been shown to bind T3 in the cytoplasm. We aimed to study μ-Crystallin expression in adipose tissue and in muscle in association with insulin action and thyroid function.

METHODS

μ-Crystallin gene expression was studied in 81 visceral and 75 sc adipose tissue samples and in 26 muscle samples from a cohort of subjects with a wide spectrum of adiposity (cohort 1). μ-Crystallin was also evaluated in 30 morbidly obese subjects in whom insulin action was evaluated using euglycemic clamp (cohort 2) and in 22 sc adipose tissue samples obtained before and after bariatric surgery-induced weight loss (cohort 3). μ-Crystallin was also evaluated during differentiation of human adipocytes. μ-Crystallin was overexpressed in human sc adipocytes using lentiviruses.

RESULTS

μ-Crystallin gene expression was 2.6- to 3-fold higher in sc vs visceral adipose tissue in direct association with the expression of thyroid hormone receptor α 1 in cohort 1 and cohort 2. Visceral, but not sc, adipose tissue μ-Crystallin was positively associated with the serum T3/T4 ratio in cohort 1 and with insulin sensitivity in cohort 2. In fact, μ-Crystallin gene expression was significantly decreased in visceral adipose tissue (-43%) and in muscle (-26%) in subjects with impaired fasting glucose and type 2 diabetes. Weight loss did not result in significant sc adipose tissue μ-Crystallin changes. μ-Crystallin overexpression led to increased insulin-induced (Ser473)Akt phosphorylation in sc adipocytes. During differentiation of adipocytes, μ-Crystallin gene expression decreased in both visceral (P = .006) and sc (P = .003) adipocytes from obese subjects.

CONCLUSION

Visceral, but not sc, adipose tissue μ-Crystallin is an adipose tissue factor linked to parameters of thyroid hormone action (T3/T4 ratio) and might mediate the interaction of thyroid function and insulin sensitivity.

Transducin-like enhancer of split 3 (TLE3) in adipose tissue is increased in situations characterized by decreased PPARγ gene expression

Transgenic overexpression of adipose tissue (AT) transducin-like enhancer of split 3 (TLE3) mimicked peroxisome proliferator-activated receptor gamma (PPARγ) agonists, improving insulin resistance in mice. This study aimed to investigate TLE3 gene expression (qRT-PCR) and protein (Western blot) in subjects with a wide spectrum of obesity and insulin sensitivity and in an independent cohort of obese subjects following surgery-induced weight loss. TLE3 was analyzed in human adipocytes and after treatment with rosiglitazone. Given the findings in humans, TLE3 was also investigated in mice after a high-fat diet (HFD) and in PPARγ knockout mice. Subcutaneous (SC) AT TLE3 was increased in subjects with type 2 diabetes (T2D). In fact, SC TLE3 was associated with increased fasting glucose (r = 0.25, p = 0.015) and S6K1 activity (r = 0.671, p = 0.003), and with decreased Glut4 (r = -0.426, p = 0.006) and IRS-1 expression (-31 %, p = 0.007) and activation (P-IRS-1/IRS-1, -17 %, p = 0.024). TLE3 was preferentially expressed in mature adipocytes and increased during in vitro differentiation in parallel to PPARγ. Weight loss led to improved insulin sensitivity, increased AT PPARγ and decreased TLE3 (-24 %, p = 0.0002), while rosiglitazone administration downregulated TLE3 gene expression in fully differentiated adipocytes (-45 %, p < 0.0001). The concept that TLE3 may act as a homeostatic linchpin in AT was also supported by its increased expression in HFD-fed mice (39 %, p = 0.013) and PPARγ knockout (74 %, p = 0.001). In summary, increased AT TLE3 in subjects with T2D and in AT from HFD-fed and PPARγ knockout mice suggest that TLE3 may play an adaptive regulatory role that improves AT function under decreased PPARγ expression.

KEY MESSAGE

TLE3 is expressed in mature adipocytes concomitantly with PPARγ. Subcutaneous adipose TLE3 is increased in T2D patients. Adipose TLE3 is upregulated in genetically ablated PPARγ and HFD-fed mice. TLE3 may be a homeostatic linchpin in insulin resistance and defective PPARγ.

Inflammation in adipose tissue and fatty acid anabolism: when enough is enough!

Recent findings in adipose tissue (AT) have uncovered negative interactions among obesity, lipogenesis, and fatty acid (FA) storage, perhaps in response to the increased production of proinflammatory cytokines and transcription factors. Emerging evidence highlights that local hypoxia, generation of reactive oxygen and nitrogen species, increased immune cells infiltration and activation, senescence, inflammation, energy consumption, and decreased lipogenesis in the AT are interrelated and may lead to impaired cytokine and hormonal secretion by adipocytes, and ectopic fat deposition in obesity that strengths the increased risk of suffering metabolic disorders in obese subjects. The information summarized in this review attempts to defend the interdependent relationship of these proofs of concept, supporting the idea that "inflamed" and "dysfunctional" AT are synonymous when referring to obesity. This may happen in severe obese subjects with a large and long-lasting fat excess, when fat depots have reached the point in which excessive fat storage, cell density, and diminished oxygen availability promote decreased lipo/adipogenesis and increased lipolysis and FA release. This response may be induced by an important inflammatory component that promotes angiogenesis and insulin resistance, but also by leptin and the increase of T3 in hyperplastic AT.

Iron and obesity status-associated insulin resistance influence circulating fibroblast-growth factor-23 concentrations

Fibroblast growth factor 23 (FGF-23) is known to be produced by the bone and linked to metabolic risk. We aimed to explore circulating FGF-23 in association with fatness and insulin sensitivity, atherosclerosis and bone mineral density (BMD). Circulating intact FGF-23 (iFGF-23) and C-terminal (CtFGF-23) concentrations (ELISA) were measured in 133 middle aged men from the general population in association with insulin sensitivity (Cohort 1); and in association with fat mass and bone mineral density (DEXA) and atherosclerosis (intima media thickness, IMT) in 78 subjects (52 women) with a wide range of adiposity (Cohort 2). Circulating iFGF-23 was also measured before and after weight loss. In all subjects as a whole, serum intact and C-terminal concentrations were linearly and positively associated with BMI. In cohort 1, both serum iFGF-23 and CtFGF-23 concentrations increased with insulin resistance. Serum creatinine contributed to iFGF-23 variance, while serum ferritin and insulin sensitivity (but not BMI, age or serum creatinine) contributed to 17% of CtFGF-23 variance. In cohort 2, CtFGF-23 levels were higher in women vs. men, and increased with BMI, fat mass, fasting and post-load serum glucose, insulin, HOMA-IR and PTH, being negatively associated with circulating vitamin D and ferritin levels. The associations of CtFGF-23 with bone density in the radius, lumbar spine and carotid IMT were no longer significant after controlling for BMI. Weight loss led to decreased iFGF-23 concentrations. In summary, the associations of circulating FGF-23 concentration with parameters of glucose metabolism, bone density and atherosclerosis are dependent on iron and obesity status-associated insulin resistance.

Targeting the circulating microRNA signature of obesity

BACKGROUND

Genomic studies have yielded important insights into the pathogenesis of obesity. Circulating microRNAs (miRNAs) are valuable biomarkers of systemic diseases and potential therapeutic targets. We sought to define the circulating pattern of miRNAs in obesity and examine changes after weight loss.

METHODS

We assessed the genomewide circulating miRNA profile cross-sectionally in 32 men and after surgery-induced weight loss in 6 morbidly obese patients. The most relevant miRNAs were cross-sectionally validated in 80 men and longitudinally in 22 patients (after surgery-induced weight loss). We evaluated the effects of diet-induced weight loss in 9 obese patients. Thirty-six circulating miRNAs were associated with anthropometric variables in the initial sample.

RESULTS

In the validation study, morbidly obese patients showed a marked increase of miR-140-5p, miR-142-3p (both P < 0.0001), and miR-222 (P = 0.0002) and decreased levels of miR-532-5p, miR-125b, miR-130b, miR-221, miR-15a, miR-423-5p, and miR-520c-3p (P < 0.0001 for all). Interestingly, in silico targets leukemia inhibitory factor receptor (LIFR) and transforming growth factor receptor (TGFR) of miR-140-5p, miR-142-3p, miR-15a, and miR-520c-3p circulated in association with their corresponding miRNAs. Moreover, a discriminant function of 3 miRNAs (miR-15a, miR-520c-3p, and miR-423-5p) was specific for morbid obesity, with an accuracy of 93.5%. Surgery-induced (but not diet-induced) weight loss led to a marked decrease of miR-140-5p, miR-122, miR-193a-5p, and miR-16-1 and upregulation of miR-221 and miR-199a-3p (P < 0.0001 for all).

CONCLUSIONS

Circulating miRNAs are deregulated in severe obesity. Weight loss-induced changes in this profile and the study of in silico targets support this observation and suggest a potential mechanistic relevance.

ATP-dependent potassium channel blockade strengthens microglial neuroprotection after hypoxia-ischemia in rats

Stroke causes CNS injury associated with strong fast microglial activation as part of the inflammatory response. In rat models of stroke, sulphonylurea receptor blockade with glibenclamide reduced cerebral edema and infarct volume. We postulated that glibenclamide administered during the early stages of stroke might foster neuroprotective microglial activity through ATP-sensitive potassium (K(ATP)) channel blockade. We found in vitro that BV2 cell line showed upregulated expression of K(ATP) channel subunits in response to pro-inflammatory signals and that glibenclamide increases the reactive morphology of microglia, phagocytic capacity and TNFα release. Moreover, glibenclamide administered to rats 6, 12 and 24h after transient Middle Cerebral Artery occlusion improved neurological outcome and preserved neurons in the lesioned core three days after reperfusion. Immunohistochemistry with specific markers to neuron, astroglia, microglia and lymphocytes showed that resident amoeboid microglia are the main cell population in that necrotic zone. These reactive microglial cells express SUR1, SUR2B and Kir6.2 proteins that assemble in functional K(ATP) channels. These findings provide that evidence for the key role of K(ATP) channels in the control of microglial reactivity are consistent with a microglial effect of glibenclamide into the ischemic brain and suggest a neuroprotective role of microglia in the early stages of stroke.

Bio-Photonic Sensing Cells over transparent substrates for anti-gestrinone antibodies biosensing

In a previous work we introduced the term Bio-Photonic Sensing Cells (BICELLs), referred to periodic networks of nano-pillar suitable for biosensing when are vertically interrogated. In this article, we demonstrate the biosensing capabilities of a type of micrometric size BICELLs made of SU-8 nano-pillars fabricated over transparent substrates. We verify the biochips functionality comparing the theoretical simulations with the experimental results when are optically interrogated in transmission. We also demonstrate a sensitivity enhancement by reducing the pitch among nano-pillars from 800 to 700 nm. Thus, the Limit of Detection achievable in these types of BICELLs is in the order of 64 pg/mL for 700 nm in pitch among nano-pillars in comparison with 292 pg/mL for 800 nm in pitch when are interrogated by Fourier Transform Visible and Infrared Spectrometry. The experiments exhibited a good reproducibility with a relative standard deviation of 0.29% measured within 8 days for a specific concentration. Finally, BICELLs functionality was tested in real conditions with unpurified rabbit serum for detecting anti-gestrinone antibodies, demonstrating the high performance of this type of BICELLs to detect specific antibodies having immobilized the suitable bioreceptors onto the sensing surface.

Type I iodothyronine 5'-deiodinase mRNA and activity is increased in adipose tissue of obese subjects

Differentiation and metabolism of adipose tissue are modulated by thyroid hormones (THs), but relatively little is known about the metabolism of THs in this tissue. Expression of the genes for type I iodothyronine 5'-deiodinase (D1), leptin (LEP) and stearoyl-CoA desaturase 1 (SCD-1) was evaluated in omental (OM) and subcutaneous (SC) fat using a cohort of 70 humans. Activities of iodothyronine deiodinases (D1, D2 and D3) were assessed in a randomly selected subpopulation of 19 subjects. D1 expression was upregulated in both OM (P=0.011) and SC (P=0.003) fat of obese subjects. Concomitantly, OM (P=0.002) and SC (P=0.028) LEP expression were increased in obesity, associated with both D1 mRNA (r=0.315, P=0.014) and activity (r=0.647, P=0.023) and inversely related to SCD-1 (r=-0.266, P=0.034) expression in SC fat. Also D1 (but not D2 and D3) activity was increased in OM (∼fourfold, P=0.010) and SC (∼eightfold, P=0.004) fat of obese when compared with non-obese subjects and correlated in both OM (r=0.528, P=0.036) and SC (r=0.749, P=0.005) fat with body mass index. Our results document increased D1 gene expression and activity in adipose tissue of obese humans and suggest a role of 3,5,3'-triiodo-L-thyronine formed by D1 in response to leptin in the modulation of adipose tissue metabolism.

Circulating pigment epithelium-derived factor levels are associated with insulin resistance and decrease after weight loss

OBJECTIVE

We aimed to study circulating pigment epithelium-derived factor (PEDF) in vivo in association with insulin resistance and in vitro in human adipocytes.

METHODS

Circulating PEDF (ELISA) and metabolic profile were assessed in 125 Caucasian men. PEDF levels were also assessed in an independent cohort of subjects (n = 33) to study the effects of changing insulin action. PEDF gene expression and secretion were measured during differentiation of human preadipocytes.

RESULTS

In all subjects, PEDF was positively associated with body mass index (r = 0.326; P < 0.0001), waist-to-hip ratio (r = 0.380; P < 0.0001), HbA(1c), and fasting triglycerides and negatively with insulin sensitivity (r = -0.320; P < 0.0001). PEDF levels were significantly increased in subjects with altered glucose tolerance and type 2 diabetes. Of the inflammatory markers measured, PEDF levels were positively associated with serum soluble TNF-α receptor 1 and IL-10 in obese subjects. Interestingly, weight loss led to significantly decreased PEDF concentration from 34.8 ± 19.3 to 22.5 ± 14.2 μg/ml (P < 0.0001). Multiple linear regression analyses revealed that insulin sensitivity contributed independently to explain 14% of the variance in PEDF levels after controlling for the effects of body mass index, age, and log fasting triglycerides. Differences in PEDF observed after weight loss were related to changes in obesity, insulin resistance, and blood pressure measures. PEDF gene expression and secretion increased during differentiation of human preadipocytes.

CONCLUSION

Circulating PEDF is associated with insulin sensitivity. The findings show, for the first time in humans, that PEDF concentrations decrease significantly after weight loss in association with blood pressure. PEDF seems to be involved in human adipocyte biology.

Transferrin receptor-1 gene polymorphisms are associated with type 2 diabetes

BACKGROUND

Iron is involved in oxidative stress and type 2 diabetes (T2D). Transferrin receptor (TFRC) constitutes the major receptor by which most cells take up iron. The aim of this study was to evaluate whether TFRC gene polymorphisms are associated with T2D.

MATERIALS AND METHODS

We evaluated TFRC gene polymorphism (rs3817672, 210AG, S142G) in a sample of T2D patients and nondiabetic controls (n = 722), and 39 SNPs within the TFRC genomic region analysed by the Welcome Trust Case Control Consortium (WTCCC) (1921 T2D subjects and 3000 controls). In a subset of subjects, glucose tolerance and insulin sensitivity were also studied.

RESULTS

The frequency of the G allele at the position 210 of the TFRC gene was significantly higher in T2D patients. Both GG and GA genotypes had a 69% (P < 0.01) greater risk of developing T2D estimated under a dominant model. The increased prevalence of the G allele run in parallel to increased sex-adjusted log-serum ferritin and slightly increased soluble transferrin receptor among patients with T2D. Furthermore, post-load glucose and insulin sensitivity were significantly associated with circulating soluble transferrin receptor, and insulin sensitivity was significantly associated with serum ferritin among G allele carriers, (r = -0.33, P = 0.001) but not in AA homozygotes. Sixteen other TFRC SNPs were also associated to T2D according to the Welcome Trust Case Control Consortium data.

CONCLUSION

TFRC gene variants are associated with T2D.

Complement factor H is expressed in adipose tissue in association with insulin resistance

OBJECTIVE

Activation of the alternative pathway of the complement system, in which factor H (fH; complement fH [CFH]) is a key regulatory component, has been suggested as a link between obesity and metabolic disorders. Our objective was to study the associations between circulating and adipose tissue gene expressions of CFH and complement factor B (fB; CFB) with obesity and insulin resistance.

RESEARCH DESIGN AND METHODS

Circulating fH and fB were determined by enzyme-linked immunosorbent assay in 398 subjects. CFH and CFB gene expressions were evaluated in 76 adipose tissue samples, in isolated adipocytes, and in stromovascular cells (SVC) (n = 13). The effects of weight loss and rosiglitazone were investigated in independent cohorts.

RESULTS

Both circulating fH and fB were associated positively with BMI, waist circumference, triglycerides, and inflammatory parameters and negatively with insulin sensitivity and HDL cholesterol. For the first time, CFH gene expression was detected in human adipose tissue (significantly increased in subcutaneous compared with omental fat). CFH gene expression in omental fat was significantly associated with insulin resistance. In contrast, CFB gene expression was significantly increased in omental fat but also in association with fasting glucose and triglycerides. The SVC fraction was responsible for these differences, although isolated adipocytes also expressed fB and fH at low levels. Both weight loss and rosiglitazone led to significantly decreased circulating fB and fH levels.

CONCLUSIONS

Increased circulating fH and fB concentrations in subjects with altered glucose tolerance could reflect increased SVC-induced activation of the alternative pathway of complement in omental adipose tissue linked to insulin resistance and metabolic disturbances.

Thyroid hormone responsive Spot 14 increases during differentiation of human adipocytes and its expression is down-regulated in obese subjects

CONTEXT

Very limited information is available regarding the function of human thyroid hormone responsive Spot 14 (human S14, hS14) in adipogenesis and human adiposity.

OBJECTIVE

To evaluate hS14 levels during differentiation of human pre-adipocytes, in human fat depots and isolated fat cells.

DESIGN

This was a cross-sectional study.

SUBJECTS

A total of 161 omental (OM) and 87 subcutaneous (SC) adipose tissue samples obtained during elective surgical procedures from a population who varied widely in terms of obesity.

MEASUREMENTS

hS14 gene expression and protein levels during adipogenesis were assessed by RT-PCR, western blot, and using an automated confocal imaging approach.

RESULTS

hS14 gene expression levels were decreased in OM adipose tissue from overweight (-42.0%) and obese subjects (-56.5%) compared with lean subjects (P<0.05 and P<0.0001, respectively). hS14 mRNA (but not hS14-related) was inversely associated with obesity measures such as body mass index (P=0.001), percent fat mass (P=0.001), waist-to-hip ratio (P=0.020), and systolic blood pressure (P=0.031). hS14 gene expression and protein levels were up-regulated at the early stages of differentiation of human pre-adipocytes as well as for 3T3-L1 cells. That observation was most prominent in those individual cells exhibiting the more marked differentiation features. hS14 gene expression levels increased by approximately 45 000-fold in mature adipocytes. Increased hS14 levels were also found in stromal-vascular cells/pre-adipocytes (3.8-fold, P<0.05) and in adipose tissue samples (1.9-fold, P<0.0001) from SC compared with OM fat depots.

CONCLUSIONS

These results suggest that hS14 is involved in human adipogenesis, but inversely related to obesity and OM fat accumulation.

Decreased circulating lactoferrin in insulin resistance and altered glucose tolerance as a possible marker of neutrophil dysfunction in type 2 diabetes

CONTEXT

Lactoferrin is an innate immune system protein with multiple beneficial health activities.

OBJECTIVE

To gain insight in the interaction between innate immune system and metabolic disturbances (obesity and insulin resistance), we investigated the relationship between circulating lactoferrin and chronic inflammation-associated insulin resistance according glucose tolerance status in Caucasian population.

DESIGN, SETTING, PARTICIPANTS, AND MAIN OUTCOME MEASURES

Circulating nonstressed lactoferrin (ELISA), metabolic variables, and inflammatory markers were measured in 229 men, 94 with normal (NGT) and 135 with altered glucose tolerance (AGT). Lactoferrin secretion by neutrophil was investigated in whole-blood culture (four young NGT subjects, four older NGT subjects, and four patients with type 2 diabetes) under microbial lipopolysaccharide (LPS) with IL-6 and rosiglitazone treatment. We also tested the lactoferrin action in THP-1 cells under LPS stimulus.

RESULTS

Circulating lactoferrin was significantly decreased in patients with AGT (431.5 +/- 187.5 vs. 493.5 +/- 238.9 ng/ml, P = 0.02). In addition, circulating lactoferrin was negatively associated with hyperglycemia and obesity measures and positively with insulin sensitivity. Lactoferrin was negatively related to inflammatory markers, especially in AGT subjects. In ex vivo experiments, we found a significant decrease in LPS-induced lactoferrin release from neutrophils in subjects with type 2 diabetes. IL-6 coincubation decreased LPS-induced lactoferrin release in NGT subjects (P < 0.001). Finally, rosiglitazone treatment led to increased lactoferrin secretion (398 +/- 193 vs. 280.1 +/- 104.9 ng/ml, P < 0.0001). Lactoferrin decreased nuclear factor-kappabeta activation and IL-6, IL-8, and macrophage chemoattractant protein-1 expression under LPS challenge.

CONCLUSIONS

Decreased circulating lactoferrin levels may play a role in chronic low level inflammation-associated insulin resistance.

Association of circulating lactoferrin concentration and 2 nonsynonymous LTF gene polymorphisms with dyslipidemia in men depends on glucose-tolerance status

BACKGROUND

Lactoferrin, an innate immune protein with antiinflammatory properties, shows considerable antiatherosclerosis activity in animal studies. We investigated the relationship between circulating lactoferrin, lactoferrin gene (LTF, lactotransferrin) polymorphisms, dyslipidemia, and vascular reactivity in the context of glucose-tolerance status in men.

METHODS

We evaluated 2 nonsynonymous LTF polymorphisms (rs1126477 and rs1126478) and measured circulating lactoferrin concentrations by ELISA under nonstressed conditions in healthy Caucasian men (n = 188) and male patients with an altered glucose tolerance (n = 202). We also studied the association of lactoferrin concentration with vascular reactivity via high-resolution ultrasound analysis of the brachial artery in a subsample of study participants.

RESULTS

Circulating lactoferrin concentration was inversely associated with fasting triglyceride concentration (r = -0.24; P = 0.001), body mass index (BMI) (r = -0.20; P = 0.007), waist-to-hip ratio (r = -0.35; P <0.001), and fasting glucose concentration (r = -0.18; P = 0.01), and directly correlated with HDL cholesterol concentration (r = 0.21; P = 0.004). Control AG heterozygotes for rs1126477 had significantly decreased fasting triglyceride concentrations (P = 0.001). Similarly, control individuals who were G carriers for rs1126478 had significantly lower fasting triglyceride concentrations (P = 0.044) and significantly higher HDL cholesterol concentrations (P = 0.028) than AA homozygotes. These associations remained significant after controlling for age, BMI, waist-to-hip ratio, fasting glucose concentration, smoking status, and alcohol intake. Circulating lactoferrin concentration was not significantly associated with endothelium-dependent vasodilatation (EDVD) in the individuals studied (n = 95); however, lactoferrin was positively associated with EDVD in obese participants with an altered glucose tolerance (r = 0.54; P = 0.04).

CONCLUSIONS

We have identified associations among LTF polymorphisms, circulating lactoferrin concentration, fasting triglyceride concentration, and vascular reactivity in humans.

Estudio comparativo de dos soluciones de preservación en la función inicial del trasplante bipulmonar en humanos

OBJECTIVE

Compare the influence of two preservation liquids, Euro-Collins (EC) and Perfadex (P) in the pulmonary graft function in the initial phase of lung transplant in humans.

DESIGN

Retrospective study.

SCOPE

Lung transplant unit of the ICU of a university hospital.

PATIENTS

A total of 79 patients were subjected to a transplant of both lungs. The pulmonary grafts were preserved with EC in 23 cases and with P in 56 cases.

VARIABLES OF INTEREST

Pulmonary function was assessed on admission in the intensive care unit (ICU) with the PaO2/FiO2 ratio. Mortality, graft dysfunction stay in ICU and time of mechanical ventilation were also assessed at 30 days.

RESULTS

The PaO2/FiO2 ratio was significantly greater in the P group than in the EC both on admission (p<0.006) and at 12 hours (p=0.032) in the ICU. Graft dysfunction incidence was less in group P than in EC (p<0.045). There were no differences in regards to mortality at 30 days, stay in ICU and time of mechanical ventilation between both groups.

CONCLUSION

Preservation of the pulmonary graft with P as preservation liquid compared with EC is associated with better graft function in the initial phases of transplant of both lungs and with a decrease in the incidence of graft dysfunction.

Epidermoid carcinoma of the lung in stage I: factors of prognostic interest

Factors affecting stage I epidermoid cancer of the lung were studied in a series of 29 patients treated only by surgery and followed up for ten years. A set of 13 variables with a possible influence on prognosis were investigated. The application of the Cox Univariate Analysis to the different variables showed the grade of cell differentiation and the mitotic index to be predictors. In the Cox Multivariate Analysis, the proportional regression equation revealed two independently significant variables (p < 0.01), which were the Mitotic Index and Nuclear Area. Grouping patients on the basis of the prognostic variables indicated allows a better prediction for survival to be made for this series of patients.

Solitary Langerhans' cell granulomatosis of the stomach associated with gastric carcinoma

A case of Langerhans' cell granulomatosis associated with gastric adenocarcinoma is reported. A review of the literature demonstrate an association of this entity with Hodgkin or non-Hodgkin lymphomas alone. The discussion is centred on differential diagnosis from the pseudo-sarcoid granulomatous reaction. Further reports may assist in classifying the granulomatous reaction to tumours into two types, epithelioid and Langerhans.

Effect of propranolol on glycerol induced acute renal failure in rats

The effect produced by propranolol, administered for a prolonged period of time and in large doses, on renal function in rats has been studied, as well as the modifications induced by this treatment in an experimental model of acute renal failure, and the effects of a single dose of propranolol given 1 hour before provoking failure. Propranolol, administered chronically, causes sodium and water retention and increases creatinine clearance. Acute renal failure induced by glycerol in rats treated for 7 days with propranolol is less severe than the one produced in untreated animals. In this ARF model, a single dose of propranolol does not seem to have a protective effect.

[Tubular permeability maintained in post-ischemic acute renal failure (author's transl)]

The effect of nearly total renal ischemia during a two hour period on glomerular filtration and urine composition was studied in relation to tubular permeability and tubular obstruction, two mechanisms that could explain renal insuficiency after iscehmia. Studies on creatinine clearance, micropuncture and microinjection of 14C-inulin into the proximal tubules by means of a hydraulic system were performed before and after the period of ischemia. Thirty minutes after the withdrawal of arterial obstruction, the animals exhibited a maintained diuresis, 50 per cent reduction in glomerular filtration in the superficial nephrons and in the total kidney, a reduction in the proximal fractional absorption of water, and also an increase in the urinary elimination of sodium. The glomerular filtrate of cortical nephorns obtained by micropuncture in anterior areas of the proximal tubules did not differ significantly from the one obtained by micropuncture in more distal areas. The inulin injected into the proximal tubules of a kidney was entirely eliminated by it.

Fracture of the sella turcica

A patient with a fracture of the sella turcica, visible on lateral X-ray films of the skull, is described. This fracture, although not diagnosed during life, was present in approximately 20 per cent of a series of consecutive autopsies on patients who died of head injury. The significance of this injury to the hypothalamopituitary axis is discussed and methods of investigation suggested.