Aims/hypothesis
We determined the contribution to insulin resistance of the PH domain leucine-rich repeat protein phosphatase (PHLPP), which dephosphorylates Akt at Ser473, inhibiting its activity. ...We measured the abundance of PHLPP in fat and skeletal muscle from obese participants. To study the effect of PHLPP on insulin signalling,
PHLPP
(also known as
PHLPP1
) was overexpressed in HepG2 and L6 cells.
Methods
Subcutaneous fat samples were obtained from 82 morbidly obese and ten non-obese participants. Skeletal muscle samples were obtained from 12 obese and eight non-obese participants. Quantification of PHLPP-1 in human tissues was performed by immunoblotting. The functional consequences of recombinant
PHLPP1
overexpression in hepatoma HepG2 cells and L6 myoblasts were investigated.
Results
Of the 82 obese participants, 31 had normal fasting glucose, 33 impaired fasting glucose and 18 type 2 diabetes. PHLPP-1 abundance was twofold higher in the three obese groups than in non-obese participants (
p
= 0.004). No differences were observed between obese participants with normal fasting glucose, impaired fasting glucose or type 2 diabetes. PHLPP-1 abundance was correlated with basal Akt Ser473 phosphorylation (
r
= −0.48;
p
= 0.001), BMI (
r
= 0.44;
p
< 0.0001), insulin (
r
= 0.35;
p
< 0.0001) and HOMA (
r
= 0.38;
p
< 0.0001). PHLPP-1 abundance was twofold higher in the skeletal muscle of 12 obese participants than in that of eight non-obese participants (
p
< 0.0001). Insulin treatment of HepG2 cells resulted in a dose- and time-dependent upregulation of PHLPP-1. Overexpression of
PHLPP1
in HepG2 cells and L6 myoblasts resulted in impaired insulin signalling involving Akt/glycogen synthase kinase 3, glycogen synthesis and glucose transport.
Conclusions/interpretation
Increased abundance of PHLPP-1, production of which is regulated by insulin, may represent a new molecular defect in insulin-resistant states such as obesity.
Aims/hypothesis Glucosamine, generated during hyperglycaemia, causes insulin resistance in different cells. Here we sought to evaluate the possible role of endoplasmic reticulum (ER) stress in the ...induction of insulin resistance by glucosamine in skeletal muscle cells. Methods Real-time RT-PCR analysis, 2-deoxy-d-glucose (2-DG) uptake and western blot analysis were carried out in rat and human muscle cell lines. Results In both rat and human myotubes, glucosamine treatment caused a significant increase in the expression of the ER stress markers immunoglobulin heavy chain-binding protein/glucose-regulated protein 78 kDa (BIP/GRP78 also known as HSPA5), X-box binding protein-1 (XBP1) and activating transcription factor 6 (ATF6). In addition, glucosamine impaired insulin-stimulated 2-DG uptake in both rat and human myotubes. Interestingly, pretreatment of both rat and human myotubes with the chemical chaperones 4-phenylbutyric acid (PBA) or tauroursodeoxycholic acid (TUDCA), completely prevented the effect of glucosamine on both ER stress induction and insulin-induced glucose uptake. In both rat and human myotubes, glucosamine treatment reduced mRNA and protein levels of the gene encoding GLUT4 and mRNA levels of the main regulators of the gene encoding GLUT4 (myocyte enhancer factor 2 a MEF2A and peroxisome proliferator-activated receptor-γ coactivator 1α PGC1α). Again, PBA or TUDCA pretreatment prevented glucosamine-induced inhibition of GLUT4 (also known as SLC2A4), MEF2A and PGC1α (also known as PPARGC1A). Finally, we showed that overproduction of ATF6 is sufficient to inhibit the expression of genes GLUT4, MEF2A and PGC1α and that ATF6 silencing with a specific small interfering RNA is sufficient to completely prevent glucosamine-induced inhibition of GLUT4, MEF2A and PGC1α in skeletal muscle cells. Conclusions/interpretation In this work we show that glucosamine-induced ER stress causes insulin resistance in both human and rat myotubes and impairs GLUT4 production and insulin-induced glucose uptake via an ATF6-dependent decrease of the GLUT4 regulators MEF2A and PGC1α.
We developed and tested an innovative physical training method in older adults that embeds the gym program into everyday life in the most conservative way possible. Physical training was included in ...the activities of local parishes where older women from Southern Italy spend most of their free time and was delivered by trained physical therapists with the support of an ICT tool known as CoCo. 113 older women (aged 72.0 69.0-75.0 years) noncompliant to conventional exercise programs participated to the study. 57 of them underwent the final anthropometric assessment and 50 the final physical tests. In study completers handgrip strength and physical performance evaluated with the chair-stand, the two minutes step and the chair-sit and -reach tests significantly improved. Quality of life as evaluated with the EuroQol-5dimension (EQ-5D) questionnaire improved as well. In conclusion, a training program designed to minimally impact on life habits of older people is effective in improving fitness in patients noncompliant to other to physical exercise programs.
Hearing loss, occurring in 1-3/1,000 newborns in the well-babies population, is one of the most common congenital diseases, and hearing screening at birth still represents the only means for its ...early detection. Since 2011 the Emilia Romagna Regional Health Agency has recommended Newborn Hearing Screening for all babies at its birth points and for newborns moving to the region. The aims of this study are to analyze the results of this regional-based Newborn Hearing Screening program and to discuss the impact of the legislative endorsement on the organization.
This is an observational retrospective chart study. The recordings of well-babies and babies at Neonatal Intensive Care Units were collected during the period from January 1st 2015 to December 31st 2020. The following data were included: Newborn Hearing Screening coverage, percentage of refer at otoacoustic emissions, prevalence and entity of hearing loss, unilateral/bilateral rate, presence of audiological risk factors.
More than 99% of a total of 198,396 newborns underwent the Newborn Hearing Screening test during the period January 1st 2015 to December 31st 2020, with a coverage ranging between 99.6% and 99.9%. Overall, the percentage of confirmed hearing loss cases was about 17-30 % of refer cases, 745 children received a diagnosis of hearing loss (prevalence 3.7/1,000). Considering profound hearing loss cases, these represent 13% of bilateral hearing loss.
A regional-based Newborn Hearing Screening program is valuable and cost-effective. In our experience, the centralization of the data system and of the data control is crucial in order to implement its efficiency and effectiveness. Healthcare policies, tracking systems and public awareness are decisive for a successful programme implementation.
Hearing loss in children causes a deficit in early perceptive and language skills. The objective of this study was to evaluate early receptive and expressive language outcomes in children with ...hearing loss, identified by hearing screening, compared to the time of diagnosis. We studied 18 severely hearing impaired children who were divided into two groups according to the time of diagnosis. Evaluation of communicative language ability was carried out at 18 month of age using the "MacArthur Child Development Inventory" questionnaire, while evaluation of acoustic-perceptual abilities was assessed with the Genovese-Arslan protocol every three months following diagnosis. The linguistic communicative and acoustic-perceptual outcomes of hearing impaired children diagnosed before 6 months of age followed those expected for normally hearing children, with a trend of temporal progression of skills that were faster than those of children diagnosed after 6 months of age.
We report two new mutations in the myophosphorylase gene (PYGM) in two unrelated Italian patients with myophosphorylase deficiency (McArdle's disease). In one, we identified a missense C-to-T ...mutation at codon 269 in exon 7, changing CGA (arginine) to TGA (stop codon) (R269X). The second patient carried a G-to-C mutation, changing GCT (alanine) to CCT (proline) at codon 686 (A686P) in exon 17. Both were compound heterozygous, with the common mutation at codon 49 (R49X) on the other allele.
Our data further expand the genetic heterogeneity in patients with McArdle's disease, suggesting that the possibility of novel mutations has to be taken into account when performing genetic analysis in distinct ethnic groups.
Since cement-based composites have been used for more than one century in civil and other engineering areas, a relevant number of international and local standards has been produced in order to ...ensure the quality and durability of employed materials and, so, structural safety for users. Among all meaningful chemical, physical and mechanical properties early age properties represent a key parameter to predict the extent of early age cracking risk, which is one of the main causes of reduction in service life (the so-called "Vita Nominale" in Italian Structural Code Ministerial Decree 14/01/2008) respect to design hypothesis. The knowledge of shrinkage phenomena, which are deformations associated to the complex chemical reactions of cementitious materials, is related to the reliability of the measurement method and, if a proper measure is accomplished, an adequate mitigation strategy can be chosen among existing alternatives (shrinkage reducing admixtures, internal curing, superabsorbent polymers, etc.). Geopolymer matrices represent one of the main sustainable alternatives to traditional cementitious binders such as ordinary Portland cement (OPC) and other clinker-based materials offering several potential advantages like higher fire resistance, durability, etc. At the moment, real scale applications are limited and, so, a relevant amount of data is still needed to assess the actual early age and long-term behavior of these systems. Particularly, the early-age monitoring of geopolymers represent a key parameter for mix design optimization. In order to assist in describing these processes, which are related to complex chemistry and drying phenomena, in this paper we have simultaneously measured the early-age shrinkage and temperature changes of metakaolin-based geopolymers by using Fiber Bragg Grating FBG-based sensors. Furthermore, we have evaluated workability limits respect to designed layout, in order to reduce the risk of excessive entrapped air, which could affect measurement accuracy. The use of this technique allowed optimizing filler content in order to minimize shrinkage and, at the same time, respect the criterion of resource efficiency.
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