microRNA expression and function in Embryonic Stem Cells: miR-100, miR-137 and miR-34a are required for ESC differentiation

Given their capacity to self-renew and differentiate efficiently into the different cell types, Embryonic Stem Cells (ESCs) provide a valid model to understand the complex network of signaling interactions in the mammalian embryo and open up new possibilities for cell therapy. So a deeper understanding of the molecular mechanisms that regulate generation, self-renewal and differentiation of ESCs is become crucial not only to fulfill their clinical promise but also to get insight into the molecular mechanisms controlling early events of mammalian development. The emergence of microRNAs (microRNAs) as potent regulators of gene expression at the post-transcriptional level has broad implications in all facets of biology, including ESCs and early development. In recent years, the role of microRNAs in ESCs and mammalian embryogenesis has begun to be explored but specific roles of the microRNAs in the regulation of ESC specific fate are still largely unknown. In this context, our interest is to identify microRNAs regulating ESC functions. We performed a systematic comparison of microRNA expression in undifferentiated versus differentiating mouse ESCs. We report that different microRNAs are increased upon the induction of differentiation. We compared the entire list of candidate mRNA targets of upregulated microRNAs with that of mRNA dowregulated in ESCs upon the induction of differentiation. Among the candidate targets emerged from this analysis, we found three genes Smarca5, Jarid1b and Sirt1, previously demonstrated to be necessary to sustain the undifferentiated phenotype in ESCs. On this basis, we first demonstrated that Smarca5 is a direct target of miR-100, Jarid1b of miR-137 and confirmed previously published data demonstrating that Sirt1 is a direct target of miR-34a in a different context. The suppression of these three microRNAs by anti-miRs caused block of ESC differentiation induced by LIF withdrawal. On the other hand, the overexpression of the three microRNAs resulted in an altered expression of differentiation markers. These results demonstrated that miR-100, miR-137 and miR-34a are required for proper differentiation of ESCs, and that they function by targeting, among the others, the mRNAs of Smarca5, Jarid1b and Sirt1. In conclusion, we have characterized a subset of microRNAs that are necessary for proper differentiation of mouse ESCs. The identification of microRNAs that are up-regulated upon the induction of ESC differentiation suggests that they suppress, directly or indirectly, the expression of genes necessary to maintain ESCs in the undifferentiated state. The identification of targets of the microRNAs that we have studied may provide tools to drive ESC differentiation towards specific lineages

K -> pion Semileptonic Form Factors from Two-Flavor Lattice QCD

We present new lattice results of the K -> pion semileptonic form factors obtained from simulations with two flavors of dynamical twisted-mass fermions, using pion masses as light as 260 MeV. Our main result is f+(0) = 0.9560 (84), which, combined with the latest experimental data for Kl3 decays, leads to |V_{us}| = 0.2267 (5)_exp (20)_f+(0). Using the PDG(2008) determinations of |Vud| and |Vub| our result implies for the unitarity relation |Vud|**2 + |Vus|**2 + |Vub|**2 = 1.0004 (15). For the O(p**6) term of the chiral expansion of f+(0) we get Df = f+(0) - 1 - f2 = -0.0214 (84).Comment: 4 pages, 4 figures, 1 table, revte

Adherence to the Mediterranean Diet and Circulating Levels of Sirtuin 4 in Obese Patients: A Novel Association

PURPOSE: This study was aimed at evaluating sirtuin 4 (Sirt4) levels in obese individuals, in relation to their adherence to the Mediterranean diet (MD), a healthy dietary pattern characterized by high antioxidant capacity, and markers of visceral fat storage. SUBJECTS/METHODS: Forty-three obese patients (44% males; BMI: 36.7-58.8 kg/m2) were consecutively included. PREvención con DIeta MEDiterránea (PREDIMED) and the 7-day food records were used to assess the adherence to MD and dietary pattern, respectively. Visceral adiposity index (VAI) was calculated. Sirt4 levels were detected by ELISA method. RESULTS: The majority of the obese participants (62.8%) had an average adherence to MD. Compared with average adherers, low adherers had higher BMI, energy intake, and percentage of energy from lipids, mainly saturated fat and polyunsaturated fatty acids (PUFA), and lower Sirt4 levels. After adjusting for BMI, Sirt4 levels remained negatively correlated with VAI. After adjusting for total energy intake, Sirt4 levels remained negatively associated with PREDIMED and consumption of n-3 PUFA, vitamins C and E. The threshold value of PREDIMED predicting the lowest decrease in Sirt4 levels was found at a score of 6. CONCLUSIONS: Less reduced Sirt4 levels in obese patients adhering to MD suggest a further aspect of the antioxidant advantage of MD

Nutrition, inflammation and liver-spleen axis

Chronic low-grade systemic inflammation represents a mechanism common to many diseases linked to atherosclerosis-related pathways. There is a growing body of evidence indicating that the combination of food quantity and quality along with genetic susceptibility are able to induce the aberrant activation of innate immune signalling, which initially contributes to chronic low-grade inflammation. Liver represents the central player to inflammatory response. Dietary/metabolic factors contribute to the pathogenesis of Non-alcoholic Fatty Liver Disease (NAFLD), the main causes of liver disease in the Western world. Enlargement of the spleen, central organ in regulating the inflammation-related immune response, is commonly seen in patients with of NAFLD, depicting the so called "liver-spleen axis." The aim of this review was to provide an at-a-glance overview of the possible bi-directional mechanisms linking nutrition and inflammation, particularly pinpointing the inflammatory effects stemmed by nutrition on "liver-spleen axis." In particular, the role of unhealthy diet, healthy dietary patterns, such as the Mediterranean diet style, dietary vitamins and micronutrients, such as vitamin D or Magnesium, and Glucagon-Like Peptide-1, a well-known incretin released in response to meal intake, will be discussed. The highly variability of the inflammatory response highlights the role of expert nutritionists in refining methodologies apt to assess nutritional epidemiology and to apply appropriate dietary intervention to counteract diet-induced inflammation mechanisms

Preliminary data on the relationship between circulating levels of Sirtuin 4, anthropometric and metabolic parameters in obese subjects according to growth hormone/insulin-like growth factor-1 status

Background: The main components of GH/insulin-like growth factor (IGF)-1 axis and Sirtuin 4 (Sirt4), highly expressed in liver and skeletal muscle mitochondria, serve as active regulators of mitochondrial oxidative capacity with opposite functions. In obesity both GH/IGF-1 status and serum Sirt4 levels, likely mirroring its reduced mitochondrial expression, might be altered. Objective: To evaluate the association between circulating levels of Sirt4, body composition, metabolic parameters and cardio-metabolic risk profile in obese patients according to their different GH/IGF-1 status. Design: Cross-sectional study with measurement of serum Sirt4, GH after GH releasing hormone (GHRH)+Arginine test, IGF-1 and assessment of body composition, glucose and lipid metabolism in 50 class II-III obese subjects (BMI 35.6 to 62.1kg/m2) and 15 normal weight subjects. Low GH secretion and IGF-1 were defined using pre-determined cutoff-points. The Homeostatic Metabolic Assessment of insulin resistance index and Visceral adiposity index were also calculated. The association of Sirt4 with peak stimulated GH and IGF-1, body composition, metabolic parameters and cardio-metabolic risk profile was assessed. Results: Serum Sirt4 was inversely related to anthropometric and metabolic parameters and positively related to peak GH and IGF-1. After adjusting for peak GH and IGF-1, the relationships between Sirt4 and BMI became not significant. At multiple regression analysis IGF-1 (p < 0.001) was the independent predictor for Sirt4. Conclusion: There was a close relationship between low IGF-1 and low serum Sirt4. This observation suggested that in obese patients, low GH/IGF-1 status was likely associated with a major compensatory decrease in circulating levels of Sirt4 to oppose to its negative regulator effect on mitochondrial oxidative capacity

Nutrition: a key environmental dietary factor in clinical severity and cardio-metabolic risk in psoriatic male patients evaluated by 7-day food-frequency questionnaire

Western dietary pattern is included among the environmental dietary factors involved in the pathogenesis of psoriasis. Nutritional data collection methods and gender differences might affect the association between diet and psoriasis. The 7-day food records is considered the "gold standard" of self-administered food frequency questionnaires. In this study, we evaluated the differences in the dietary intake, anthropometric measurements and cardio-metabolic risk profile in a group of psoriatic patients compared with an age and Body Mass Index (BMI)-matched control group. In addition, in the group of psoriatic patients we investigated the association between the dietary intake and clinical severity of psoriasis

Bioelectronic recordings of cardiomyocytes with accumulation mode electrolyte gated organic field effect transistors

Versió postprint del document publicat a: https://doi.org/10.1016/j.bios.2019.111844Organic electronic materials offer an untapped potential for novel tools for low-invasive electrophysiological recording and stimulation devices. Such materials combine semiconducting properties with tailored surface chemistry, elastic mechanical properties and chemical stability in water. In this work, we investigate solution processed Electrolyte Gated Organic Field Effect Transistors (EGOFETs) based on a small molecule semiconductor. We demonstrate that EGOFETs based on a blend of soluble organic semiconductor 2,8-Difluoro-5,11-bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) combined with an insulating polymer show excellent sensitivity and long-term recording under electrophysiological applications. Our devices can stably record the extracellular potential of human pluripotent stem cell derived cardiomyocyte cells (hPSCs-CMs) for several weeks. In addition, cytotoxicity tests of pharmaceutical drugs, such as Norepinephrine and Verapamil was achieved with excellent sensitivity. This work demonstrates that organic transistors based on organic blends are excellent bioelectronics transducer for extracellular electrical recording of excitable cells and tissues thus providing a valid alternative to electrochemical transistors

Liver-spleen axis, insulin-like growth factor-(IGF)-I axis and fat mass in overweight/obese females

<p>Abstract</p> <p>Background</p> <p>Fat mass (FM) in overweight/obese subjects has a primary role in determining low-grade chronic inflammation and, in turn, insulin resistance (IR) and ectopic lipid storage within the liver. Obesity, aging, and FM influence the growth hormone/insulin-like growth factor (IGF)-I axis, and chronic inflammation might reduce IGF-I signaling. Altered IGF-I axis is frequently observed in patients with Hepatic steatosis (HS). We tested the hypothesis that FM, or spleen volume and C-reactive protein (CRP)--all indexes of chronic inflammation--could affect the IGF-I axis status in overweight/obese, independently of HS.</p> <p>Methods</p> <p>The study population included 48 overweight/obese women (age 41 ± 13 years; BMI: 35.8 ± 5.8 kg/m²; range: 25.3-53.7), who underwent assessment of fasting plasma glucose and insulin, homeostasis model assessment of insulin resistance (HOMA), cholesterol and triglycerides, HDL-cholesterol, transaminases, high-sensitive CRP, uric acid, IGF-I, IGF binding protein (BP)-1, IGFBP-3, and IGF-I/IGFBP-3 ratio. Standard deviation score of IGF-I according to age (zSDS) were also calculated. FM was determined by bioelectrical impedance analysis. HS severity grading (score 0-4 according liver hyperechogenicity) and spleen longitudinal diameter (SLD) were evaluated by ultrasound.</p> <p>Results</p> <p>Metabolic syndrome (MS) and HS were present in 33% and 85% of subjects, respectively. MS prevalence was 43% in subjects with increased SLD. IGF-I values, but not IGF-I zSDS, and IGF-I/IGFBP-3 ratio were significantly lower, while FM%, FPI, HOMA, ALT, CRP, were significantly higher in patients with severe HS than in those with mild HS. IGF-I zSDS (r = -0.42, r = -0.54, respectively; p < 0.05), and IGFBP-1 (r = -0.38, r = -0.42, respectively; p < 0.05) correlated negatively with HS severity and FM%. IGF-I/IGFBP-3 ratio correlated negatively with CRP, HS severity, and SLD (r = -0.30, r = -0.33, r = -0.43, respectively; p < 0.05). At multivariate analysis the best determinants of IGF-I were FM% (β = -0.49; p = 0.001) and IGFBP-1 (β = -0.32; p = 0.05), while SLD was in the IGF-I/IGFBP-3 ratio (β = -0.43; p = 0.004).</p> <p>Conclusions</p> <p>The present study suggests that lower IGF-I status in our study population is associated with higher FM, SLD, CRP and more severe HS.</p

Serum 25-Hydroxyvitamin D Levels, phosphoprotein enriched in diabetes gene product (PED/PEA-15) and leptin-to-adiponectin ratio in women with PCOS

<p>Abstract</p> <p>Background</p> <p>Polycystic ovary syndrome (PCOS) is frequently associated with hypovitaminosis D. Vitamin D is endowed with pleiotropic effects, including insulin resistance (IR) and apoptotic pathway. Disruption of the complex mechanism that regulated ovarian apoptosis has been reported in PCOS. Phosphoprotein enriched in diabetes gene product (PED/PEA-15), an anti-apoptotic protein involved in type 2 diabetes mellitus (T2DM), is overexpressed in PCOS women, independently of obesity. Leptin-to-adiponectin ratio (L/A) is a biomarker of IR and low-grade inflammation in PCOS. The aim of the study was to investigate the levels of 25-hydroxy vitamin D (25(OH)D), and L/A, in association with PED/PEA-15 protein abundance, in both lean and overweight/obese (o/o) women with PCOS.</p> <p>Patients and Methods</p> <p>PED/PEA-15 protein abundance and circulating levels of 25(OH)D, L/A, sex hormone-binding globulin, and testosterone were evaluated in 90 untreated PCOS patients (25 ± 4 yrs; range 18-34) and 40 healthy controls age and BMI comparable, from the same geographical area. FAI (free androgen index) and the homeostasis model assessment of insulin resistance (HoMA-IR) index were calculated.</p> <p>Results</p> <p>In o/o PCOS, 25(OH)D levels were significantly lower, and L/A values were significantly higher than in lean PCOS (p < 0.001), while there were no differences in PED/PEA-15 protein abundance. An inverse correlation was observed between 25(OH)D and BMI, PED/PEA-15 protein abundance, insulin, HoMA-IR, FAI (p < 0.001), and L/A (p < 0.05). At the multivariate analysis, in o/o PCOS L/A, insulin and 25(OH)D were the major determinant of PED/PEA-15 protein abundance (β = 0.45, β = 0.41, and β = -0.25, respectively).</p> <p>Conclusions</p> <p>Lower 25(OH)D and higher L/A were associated to PED/PEA-15 protein abundance in PCOS, suggesting their involvement in the ovarian imbalance between pro-and anti-apoptotic mechanisms, with high L/A and insulin and low 25(OH)D levels as the main determinants of PED/PEA-15 protein variability. Further studies, involving also different apoptotic pathways or inflammatory cytokines and granulosa cells are mandatory to better define the possible bidirectional relationships between 25(OH)D, PED/PEA-15 protein abundance, leptin and adiponectin in PCOS pathogenesis.</p

Tissue engineering by decellularization and 3D bioprinting

Discarded human donor organs have been shown to provide decellularized extracellular matrix (dECM) scaffolds suitable for organ engineering. The quest for appropriate cell sources to satisfy the need of multiple cells types in order to fully repopulate human organ-derived dECM scaffolds has opened new venues for the use of human pluripotent stem cells (hPSCs) for recellularization. In addition, three-dimensional (3D) bioprinting techniques are advancing towards the fabrication of biomimetic cell-laden biomaterial constructs. Here, we review recent progress in decellularization/recellularization and 3D bioprinting technologies, aiming to fabricate autologous tissue grafts and organs with an impact in regenerative medicine