Next Generation Sequencing (NGS) Target Approach for Undiagnosed Dysglycaemia.

Next-generation sequencing (NGS) has revolutionized the field of genomics and created new opportunities for basic research. We described the strategy for the NGS validation of the "dysglycaemia panel" composed by 44 genes related to glucose metabolism disorders (MODY, Wolfram syndrome) and familial renal glycosuria using Ion AmpliSeq technology combined with Ion-PGM. Anonymized DNA of 32 previously genotyped cases with 33 different variants were used to optimize the methodology. Standard protocol was used to generate the primer design, library, template preparation, and sequencing. Ion Reporter tool was used for data analysis. In all the runs, the mean coverage was over 200×. Twenty-nine out of thirty three variants (96.5%) were detected; four frameshift variants were missed. All point mutations were detected with high sensitivity. We identified three further variants of unknown significance in addition to pathogenic mutations previously identified by Sanger sequencing. The NGS panel allowed us to identify pathogenic variants in multiple genes in a short time. This could help to identify several defects in children and young adults that have to receive the genetic diagnosis necessary for optimal treatment. In order not to lose any pathogenic variants, Sanger sequencing is included in our analytical protocol to avoid missing frameshift variants.

Automated Insulin Delivery (AID) Systems: Use and Efficacy in Children and Adults with Type 1 Diabetes and Other Forms of Diabetes in Europe in Early 2023.

Type 1 diabetes (T1D) patients' lifestyle and prognosis has remarkably changed over the years, especially after the introduction of insulin pumps, in particular advanced hybrid closed loop systems (AHCL). Emerging data in literature continuously confirm the improvement of glycemic control thanks to the technological evolution taking place in this disease. As stated in previous literature, T1D patients are seen to be more satisfied thanks to the use of these devices that ameliorate not only their health but their daily life routine as well. Limited findings regarding the use of new devices in different age groups and types of patients is their major limit. This review aims to highlight the main characteristics of each Automated Insulin Delivery (AID) system available for patients affected by Type 1 Diabetes Mellitus. Our main goal was to particularly focus on these systems' efficacy and use in different age groups and populations (i.e., children, pregnant women). Recent studies are emerging that demonstrate their efficacy and safety in younger patients and other forms of diabetes.

"Pesto" Mutation: Phenotypic and Genotypic Characteristics of Eight GCK/MODY Ligurian Patients.

Maturity Onset Diabetes of the Young (MODY) is a monogenic form of diabetes mellitus (DM) that accounts for around 2-5% of all types of diabetes. Autosomal dominant inheritance in pathogenic variations of 14 genes related to ß-cell functions can lead to monogenic types of diabetes. In Italy, GCK/MODY is the most frequent form and it is caused by mutations of the glucokinase (GCK). Patients with GCK/MODY usually have stable mild fasting hyperglycaemia with mildly elevated HbA1c levels and rarely need pharmacological treatment. Molecular analysis of the GCK coding exons was carried out by Sanger sequencing in eight Italian patients. All the probands were found to be heterozygous carriers of a pathogenic gross insertion/deletion c.1279_1358delinsTTACA; p.Ser426_Ala454delinsLeuGln. It was previously described for the first time by our group in a large cohort of Italian GCK/MODY patients. The higher levels of HbA1c (6.57% vs. 6.1%), and the higher percentage of patients requiring insulin therapy (25% vs. 2%) compared to the previously studied Italian patients with GCK/MODY, suggest that the mutation discovered could be responsible for a clinically worse form of GCK/MODY. Moreover, as all the patients carrying this variant share an origin from the same geographic area (Liguria), we postulate a possible founder effect and we propose to name it the "pesto" mutation.

Diabetes Mellitus Diagnosed in Childhood and Adolescence With Negative Autoimmunity: Results of Genetic Investigation.

Monogenic diabetes is a rare form of diabetes, accounting for approximately 1% to 6% of pediatric diabetes patients. Some types of monogenic diabetes can be misdiagnosed as type 1 diabetes in children or adolescents because of similar clinical features. Identification of the correct etiology of diabetes is crucial for clinical, therapeutic, and prognostic issues. Our main objective was to determine the prevalence of monogenic diabetes in patients with diabetes mellitus, diagnosed in childhood or in adolescence, and negative autoimmunity. We retrospectively analyzed clinical data of 275 patients diagnosed with insulin-dependent diabetes at age <18yr in the last 10 years. 8.4% of subjects has negative autoimmunity. Their DNA was sequenced by NGS custom panel composed by 45 candidate genes involved in glucose metabolism disorder. Two novel heterozygous pathogenic or likely pathogenic variants (10,5% of autoantibody negative subjects) were detected: the frameshift variant c.617_618insA in NEUROD1 exon 2 and the missense change c.116T>C in INS exon 2. Our study corroborates previous results of other reports in literature. NGS assays are useful methods for a correct diagnosis of monogenic diabetes, even of rarest forms, highlighting mechanisms of pediatric diabetes pathogenesis.

An Atypical Case of Late-Onset Wolfram Syndrome 1 without Diabetes Insipidus.

Wolfram syndrome 1, a rare autosomal recessive neurodegenerative disease, is caused by mutations in the WFS1 gene. It is characterized by diabetes insipidus, diabetes mellitus, optic atrophy, and deafness (DIDMOAD), and other clinical manifestations such as urological and neurological disorders. Here we described the case of a patient with an atypical late-onset Wolfram syndrome 1 without DI. Our WS1 patient was a c.1620_1622delGTG (p.Trp540del)/c.124 C > T (p.Arg42*) heterozygous compound. The p.Arg42* nonsense mutation was also found in heterozygosity in his sister and niece, both suffering from psychiatric disorders. The p.Arg42* nonsense mutation has never been found in WS1 and its pathogenicity is unclear so far. Our study underlined the need to study a greater number of WS1 cases in order to better understand the clinical significance of many WFS1 variants.

A Novel Genetic Variant in the WFS1 Gene in a Patient with Partial Uniparental Mero-Isodisomy of Chromosome 4.

Wolfram syndrome is a rare autosomal recessive disorder characterized by optic atrophy and diabetes mellitus. Wolfram syndrome type 1 (WFS1) is caused by bi-allelic pathogenic variations in the wolframin gene. We described the first case of WFS1 due to a maternal inherited mutation with uniparental mero-isodisomy of chromosome 4. Diabetes mellitus was diagnosed at 11 years of age, with negative anti-beta cells antibodies. Blood glucose control was optimal with low insulin requirement. No pathogenic variations in the most frequent gene causative of maturity-onset diabetes of the young subtypes were detected. At 17.8 years old, a rapid reduction in visual acuity occurred. Genetic testing revealed the novel homozygous variant c.1369A>G; p.Arg457Gly in the exon 8 of wolframin gene. It was detected in a heterozygous state only in the mother while the father showed a wild type sequence. In silico disease causing predictions performed by Polyphen2 classified it as "likely damaging", while Mutation Tester and Sift suggested it was "polymorphism" and "tolerated", respectively. High resolution SNP-array analysis was suggestive of segmental uniparental disomy on chromosome 4. In conclusion, to the best of our knowledge, we describe the first patient with partial uniparental mero-isodisomy of chromosome 4 carrying a novel mutation in the wolframin gene. The clinical phenotype observed in the patient and the analysis performed suggest that the genetic variant detected is pathogenetic.

Wolfram syndrome 1 in the Italian population: genotype-phenotype correlations.

OBJECTIVES: We studied 45 patients with Wolfram syndrome 1 (WS1) to describe their clinical history and to search for possible genotype-phenotype correlations. METHODS: Clinical criteria contributing to WS1 diagnosis were analyzed. The patients were classified into three genotypic classes according to type of detected mutations. RESULTS: WS1 prevalence in Italy is 0.74/1,000,000. All four manifestations of DIDMOAD were found in 46.7% of patients. Differently combined WS1 clinical features were detected in 53.3% of patients. We found 35 WFS1 different mutations and a novel missense mutation, c.1523A>G. WS1 patients were homozygotes or compound heterozygotes for WFS1 mutations except for 2 heterozygote patients (4.5%). Each genotypic group exhibited a different age onset of DM, D, and DI but not of OA. Genotypic Group 2 patients manifested a lower number of clinical manifestations compared to Groups 1 and 3. Moreover, genotypic Group 1 patients tended to have a shorter survival time than the other groups. No differences were found regarding type of clinical pictures. CONCLUSIONS: Our study suggested that molecular WFS1 typing is a useful tool for early assessment of clinical history, follow-up, and prognosis of WS1.

A novel CISD2 intragenic deletion, optic neuropathy and platelet aggregation defect in Wolfram syndrome type 2.

BACKGROUND: Wolfram Syndrome type 2 (WFS2) is considered a phenotypic and genotypic variant of WFS, whose minimal criteria for diagnosis are diabetes mellitus and optic atrophy. The disease gene for WFS2 is CISD2. The clinical phenotype of WFS2 differs from WFS1 for the absence of diabetes insipidus and psychiatric disorders, and for the presence of bleeding upper intestinal ulcers and defective platelet aggregation. After the first report of consanguineous Jordanian patients, no further cases of WFS2 have been reported worldwide. We describe the first Caucasian patient affected by WFS2. CASE PRESENTATION: The proband was a 17 year-old girl. She presented diabetes mellitus, optic neuropathy, intestinal ulcers, sensorineural hearing loss, and defective platelet aggregation to ADP. Genetic testing showed a novel homozygous intragenic deletion of CISD2 in the proband. Her brother and parents carried the heterozygous mutation and were apparently healthy, although they showed subclinical defective platelet aggregation. Long runs of homozygosity analysis from SNP-array data did not show any degree of parental relationship, but the microsatellite analysis confirmed the hypothesis of a common ancestor. CONCLUSION: Our patient does not show optic atrophy, one of the main diagnostic criteria for WFS, but optic neuropathy. Since the "asymptomatic" optic atrophy described in Jordanian patients is not completely supported, we could suppose that the ocular pathology in Jordanian patients was probably optic neuropathy and not optic atrophy. Therefore, as optic atrophy is required as main diagnostic criteria of WFS, it might be that the so-called WFS2 could not be a subtype of WFS. In addition, we found an impaired aggregation to ADP and not to collagen as previously reported, thus it is possible that different experimental conditions or inter-patient variability can explain different results in platelet aggregation. Further clinical reports are necessary to better define the clinical spectrum of this syndrome and to re-evaluate its classification.

Hyperglycaemia and ß-cell antibodies: is it always pre-type 1 diabetes?

We describe 10-year-old girl with mild incidental hyperglycaemia, impaired glucose tolerance and GADA positivity. Family history for mild hyperglycaemia and GADA fluctuation alerted us to a possible MODY diagnosis which was confirmed by detection of GCK mutation c.626C>T; p.T209M. Weak or transient ß-cell autoimmunity should not preclude genetic testing for MODY when the clinical features are suggestive.

Wolfram syndrome: new mutations, different phenotype.

BACKGROUND: Wolfram Syndrome (WS) is an autosomal recessive neurodegenerative disorder characterized by Diabetes Insipidus, Diabetes Mellitus, Optic Atrophy, and Deafness identified by the acronym "DIDMOAD". The WS gene, WFS1, encodes a transmembrane protein called Wolframin, which recent evidence suggests may serve as a novel endoplasmic reticulum calcium channel in pancreatic ß-cells and neurons. WS is a rare disease, with an estimated prevalence of 1/550.000 children, with a carrier frequency of 1/354. The aim of our study was to determine the genotype of WS patients in order to establish a genotype/phenotype correlation. METHODOLOGY/PRINCIPAL FINDINGS: We clinically evaluated 9 young patients from 9 unrelated families (6 males, 3 females). Basic criteria for WS clinical diagnosis were coexistence of insulin-treated diabetes mellitus and optic atrophy occurring before 15 years of age. Genetic analysis for WFS1 was performed by direct sequencing. Molecular sequencing revealed 5 heterozygous compound and 3 homozygous mutations. All of them were located in exon 8, except one in exon 4. In one proband only an heterozygous mutation (A684V) was found. Two new variants c.2663 C>A and c.1381 A>C were detected. CONCLUSIONS/SIGNIFICANCE: Our study increases the spectrum of WFS1 mutations with two novel variants. The male patient carrying the compound mutation [c.1060_1062delTTC]+[c.2663 C>A] showed the most severe phenotype: diabetes mellitus, optic atrophy (visual acuity 5/10), deafness with deep auditory bilaterally 8000 Hz, diabetes insipidus associated to reduced volume of posterior pituitary and pons. He died in bed at the age of 13 years. The other patient carrying the compound mutation [c.409_424dup16]+[c.1381 A>C] showed a less severe phenotype (DM, OA).

The coexistence of type 1 diabetes, MODY2 and metabolic syndrome in a young girl.

Even though autoantibodies to pancreatic islet cells are normally found in type 1 diabetes and insulin-resistance due to overweight is more reminiscent of type 2 diabetes, some studies have described ß-cell antibodies also in maturity-onset diabetes of the young (MODY) and in type 2 diabetes. A 7-year-old girl was referred to our Unit for incidental hyperglycemia and family history of MODY2 and type 2 diabetes. Genetic evaluation confirmed mutation L134P in exon 4 of the glucokinase gene and a high HLA-risk of type 1 diabetes. During follow-up, she developed type 1 diabetes and overweight-induced metabolic syndrome. The coexistence of MODY, type 1 diabetes and overweight-induced metabolic syndrome confirms that diabetes subtype probably represents a continuum of immune and metabolic dysfunction modified by genetic factors.

Mother and daughter carrying the same KCNJ11 mutation but with a different response to switching from insulin to sulfonylurea.

KCNJ11 gene mutations are related to permanent neonatal diabetes mellitus (PNDM). Glycemic stability minimizes the risk of complications. Sulfonylureas (SU) are the proven best therapeutic option. We report a 18-month follow-up of switching from insulin to SU in a mother and her daughter with PNDM due to KCNJ11 mutation.

p38 MAPK and JNK antagonistically control senescence and cytoplasmic p16INK4A expression in doxorubicin-treated endothelial progenitor cells.

Patients treated with low-dose anthracyclines often show late onset cardiotoxicity. Recent studies suggest that this form of cardiotoxicity is the result of a progenitor cell disease. In this study we demonstrate that Cord Blood Endothelial Progenitor Cells (EPCs) exposed to low, sub-apoptotic doses of doxorubicin show a senescence phenotype characterized by increased SA-b-gal activity, decreased TRF2 and chromosomal abnormalities, enlarged cell shape, and disarrangement of F-actin stress fibers accompanied by impaired migratory ability. P16( INK4A) localizes in the cytoplasm of doxorubicin-induced senescent EPCs and not in the nucleus as is the case in EPCs rendered senescent by different stimuli. This localization together with the presence of an arrest in G2, and not at the G1 phase boundary, which is what usually occurs in response to the cell cycle regulatory activity of p16(INK4A), suggests that doxorubicin-induced p16( INK4A) does not regulate the cell cycle, even though its increase is closely associated with senescence. The effects of doxorubicin are the result of the activation of MAPKs p38 and JNK which act antagonistically. JNK attenuates the senescence, p16( INK4A) expression and cytoskeleton remodeling that are induced by activated p38. We also found that conditioned medium from doxorubicin-induced senescent cardiomyocytes does not attract untreated EPCs, unlike conditioned medium from apoptotic cardiomyocytes which has a strong chemoattractant capacity. In conclusion, this study provides a better understanding of the senescence of doxorubicin-treated EPCs, which may be helpful in preventing and treating late onset cardiotoxicity.

Sublethal doses of an anti-erbB2 antibody leads to death by apoptosis in cardiomyocytes sensitized by low prosenescent doses of epirubicin: the protective role of dexrazoxane.

The cardiotoxic synergism resulting from the sequential treatment with anthracyclines and trastuzumab has been attributed to the trastuzumab-induced loss of the erbB2-related functions that serve as a salvage pathway against the damaging effects of anthracyclines. Cellular senescence is a novel mechanism of cardiotoxicity induced by subapoptotic doses of anthracyclines. After having identified prosenescent and proapoptotic doses of epirubicin and rat MAb c-erbB2/Her-2/neu Ab-9 clone B10 (B10), an anti-erbB2 monoclonal antibody, we investigated the effects of the sequential treatment with prosenescent doses of both drugs on H9c2 cells and neonatal rat cardiomyocytes pretreated with or without the cardioprotective agent dexrazoxane. Cells were analyzed by senescence-associated beta-galactosidase, single-stranded DNA, annexin/propidium double staining, F-actin, and mitochondrial transmembrane potential. ErbB2 expression levels, AKT activation, and the effects of the inhibition of nicotinamide adenine dinucleotide phosphate oxidase [NAD(P)H oxidase] and phosphoinositide-3-OH kinase (PI3K) were also assessed. Data demonstrate that 1) the toxic effects of epirubicin mainly occur through NAD(P)H oxidase activation; 2) the erbB2 overexpression induced by epirubicin is a redox-sensitive mechanism largely dependent on NAD(P)H oxidase; 3) the loss of erbB2-related functions caused by B10 determines marginal cellular changes in untreated cells, but causes massive death by apoptosis in cells previously exposed to a prosenescent dose of epirubicin, 4) dexrazoxane promotes survival pathways, as demonstrated by the activation of Akt and the PI3K-dependent erbB2 overexpression; and 5) it also prevents epirubicin-induced senescence and renders epirubicin-treated cells more resistant to treatment with B10. Data underline the importance of NAD(P)H oxidase in epirubicin-induced cardiotoxicity and shed new light on the protective mechanisms of dexrazoxane.

Doxorubicin induces senescence or apoptosis in rat neonatal cardiomyocytes by regulating the expression levels of the telomere binding factors 1 and 2.

Low or high doses of doxorubicin induce either senescence or apoptosis, respectively, in cardiomyocytes. The mechanism by which different doses of doxorubicin may induce different stress-response cellular programs is not well understood. A recent study showed that the level of telomere dysfunction may induce senescence or apoptosis. We investigated the pathways to both apoptosis and senescence in neonatal rat cardiomyocytes and in H9c2 cells exposed to a single pulsed incubation with low or high doses of doxorubicin. High-dose doxorubicin strongly reduces TRF2 expression while enhancing TRF1 expression, and it determines early apoptosis. Low-dose doxorubicin induces downregulation of both TRF2 and TRF1, and it also increases the senescence-associated-beta-galactosidase activity, downregulates the checkpoint kinase Chk2, induces chromosomal abnormalities, and alters the cell cycle. The involvement of TRF1 and TRF2 with apoptosis and senescence was assessed by short interfering RNA interference. The cells maintain telomere dysfunction and a senescent phenotype over time and undergo late death. The increase in the phase>4N and the presence of micronuclei and anaphase bridges indicate that cells die by mitotic catastrophe. p38 modulates TRF2 expression, whereas JNK and cytoplasmic p53 regulate TRF1. Pretreatment with specific inhibitors of MAPKs and p53 may either attenuate the damage induced by doxorubicin or shift the cellular response to stress from senescence to apoptosis. In conclusion, various doses of doxorubicin induce differential regulation of TRF1 and TRF2 through p53 and MAPK, which is responsible for inducing either early apoptosis or senescence and late death due to mitotic catastrophe.

Cell-cell bond modulates vascular smooth muscle cell responsiveness to Angiotensin II.

Cell attachment is provided by cell-matrix and cell-cell bonds, and acts as a regulator of vascular smooth muscle cell (VSMC) survival, activity and homeostasis, as well as of VSMCs response to pathogenic stimuli. In this work we elicited an exclusive cell-cell contact by culturing A7r5 VSMCs on agarose-coated wells to form floating cell clusters, and we demonstrated that a steady state with a reduced response to the vasoactive peptide Angiotensin II (ATII) was induced. We found that clustered VSMCs showed subcortical stabilization of beta-catenin and Caveolin 1 (Cav1), unlike adherent confluent counterparts. We demonstrated that beta-catenin and Cav1 stabilization at the membrane level hampers the molecular cross-talk induced by ATII-activated AT1 receptor (AT1R), thereby impeding the phosphorylation of Cav1 and IGF1R, the NADPH oxidase activity, and counteracting ATII-dependent hypertrophy. Thus, elective cell-cell bond might modulate the proatherogenic activity of ATII, reducing the adverse vascular remodelling associated with AT1R activation.