A New Tool to Identify Pediatric Patients with Atypical Diabetes Associated with Gene Polymorphisms

Background

Recent diabetes subclassifications have improved the differentiation between patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus despite several overlapping features, yet without considering genetic forms of diabetes. We sought to facilitate the identification of monogenic diabetes by creating a new tool that we validated in a pediatric maturity-onset diabetes of the young (MODY) cohort.

Methods

We first created the DIAgnose MOnogenic DIAbetes (DIAMODIA) criteria based on the pre-existing, but incomplete, MODY calculator. This new score is composed of four strong and five weak criteria, with patients having to display at least one weak and one strong criterion.

Results

The effectiveness of the DIAMODIA criteria was evaluated in two patient cohorts, the first consisting of patients with confirmed MODY diabetes (n=34) and the second of patients with T1DM (n=390). These DIAMODIA criteria successfully detected 100% of MODY patients. Multiple correspondence analysis performed on the MODY and T1DM cohorts enabled us to differentiate MODY patients from T1DM. The three most relevant variables to distinguish a MODY from T1DM profile were: lower insulin-dose adjusted A1c score ≤9, glycemic target-adjusted A1c score ≤4.5, and absence of three anti-islet cell autoantibodies.

Conclusion

We validated the DIAMODIA criteria, as it effectively identified all monogenic diabetes patients (MODY cohort) and succeeded to differentiate T1DM from MODY patients. The creation of this new and effective tool is likely to facilitate the characterization and therapeutic management of patients with atypical diabetes, and promptly referring them for genetic testing which would markedly improve clinical care and counseling, as well.

Near adult height and BMI changes in growth hormone treated short children with Noonan syndrome: the Belgian experience

Introduction A variable near adult height (NAH) outcome after growth hormone (GH) therapy in Noonan syndrome (NS) patients with short stature has been reported. The main objective of this study was to evaluate NAH and body mass index (BMI) evolution in a large Belgian cohort of NS patients treated for short stature. The secondary objectives were to investigate whether sex, genotype, the presence of a thoracic deformity and/or a heart anomaly might affect NAH and to validate the recently developed NAH prediction model by Ranke et al. Methods Clinical and auxological data of GH treated short NS patients born before 2001 were extracted from the national Belgrow registry. NAH was available in 54 (35 male) genotyped NS using a gene panel of 9 genes, showing pathogenic variants in PTPN11 in 32 and in SOS1 in 5 patients, while in 17 patients gene panel analysis was inconclusive (no mutation group). Results After a median (P10; P90) duration of 5.4 (2.2-10.3) years of GH therapy with a median dose of 0.05 mg/kg/day NS patients reached a median NAH of -1.7 (-3.4; -0.8) SDS. Median total height gain was 1.1 (0.1; 2.3) SDS. Sex, genotype and the presence of a thoracic or cardiac malformation did not correlate with NAH or total height gain. Linear regression modelling revealed that height SDS at start (beta=0.90, p<0.001), mid-parental height SDS (beta =0.27; p=0.005), birth weight SDS (beta=0.15; p=0.051), age at start (beta=0.07; p=0032) were independently associated with NAH SDS. Median BMI SDS increased significantly (p<0.001) from -1.0 (-2.5; 0.0) at start to -0.2 (-1.5; 0.9) at NAH. The observed NAH in a subgroup of 44 patients with more than 3 years of GH treatment was not statistically different from the predicted NAH by the Noonan NAH prediction model of Ranke. Conclusion Long-term GH therapy at a dose of 0.05 mg/kg/day in short NS patients is effective in improving adult height and BMI, irrespective of the genotype and presence or absence of cardiac and or thoracic anomalies.

Post-Hypoglycemic hyperglycemia are highly relevant markers for stratification of glycemic variability and partial remission status of pediatric patients with new-onset type 1 diabetes

AIMS

To evaluate whether parameters of post-hypoglycemic hyperglycemia (PHH) correlated with glucose homeostasis during the first year after type 1 diabetes onset and helped to distinguish pediatric patients undergoing partial remission or not.

METHODS

In the GLUREDIA (GLUcagon Response to hypoglycemia in children and adolescents with new-onset type 1 DIAbetes) study, longitudinal values of clinical parameters, continuous glucose monitoring metrics and residual β-cell secretion from children with new-onset type 1 diabetes were analyzed during the first year after disease onset. PHH parameters were calculated using an in-house algorithm. Correlations between PHH parameters (i.e., PHH frequency, PHH duration, PHH area under the curve [PHHAUC]) and glycemic homeostasis markers were studied using adjusted mixed-effects models.

RESULTS

PHH parameters were strong markers to differentiate remitters from non-remitters with PHH/Hyperglycemia duration ratio being the most sensitive (ratio<0.02; sensitivity = 86% and specificity = 68%). PHHAUC moderately correlated with parameters of glucose homeostasis including TIR (R2 = 0.35, p-value < 0.05), coefficient of variation (R2 = 0.22, p-value < 0.05) and Insulin-Dose Adjusted A1c (IDAA1C) (R2 = 0.32, p-value < 0.05) and with residual β-cell secretion (R2 = 0.17, p-value < 0.05). Classification of patients into four previously described glucotypes independently validated PHH parameters as reliable markers of glucose homeostasis and improved the segregation of patients with intermediate values of IDAA1C and estimated C-peptide (CPEPEST). Finally, a combination of PHH parameters identified groups of patients with specific patterns of hypoglycemia.

CONCLUSION

PHH parameters are new minimal-invasive markers to discriminate remitters from non-remitters and evaluate glycemic homeostasis during the first year of type 1 diabetes. PHH parameters may also allow patient-targeted therapeutic management of hypoglycemic episodes.

Case Report: Aggressive neural crest tumors in a child with familial von Hippel Lindau syndrome associated with a germline VHL mutation (c.414A>G) and a novel KIF1B gene mutation

Introduction

Von Hippel Lindau (VHL) syndrome is caused by an autosomal dominant hereditary or sporadic germline mutation of the VHL gene with more than five hundred pathogenic mutations identified. Pheochromocytomas and rarely paragangliomas occur in 10-50% of patients with VHL syndrome usually around 30 years of age and exceptionally before the age of 10.

Case presentation

We diagnosed a 9-year-old girl of normal appearance and severe refractory hypertension, with a norepinephrine-secreting pheochromocytoma related to VHL syndrome due to a known familial germline heterozygous mutation of VHL gene (c.414A>G), also present in three members of her family. At age 13, a pelvic tumor and a left adrenal pheochromocytoma that showed to be multi-metastatic to both lungs were discovered in the patient leading to left adrenalectomy and pelvic tumor resection. In addition to the germline VHL gene mutation, blood analysis using Next Generation Sequencing identified a novel heterozygous germline mutation of the KIF1B gene (c.3331_3332del; p.Asn1111Glnfs*21), which is only present in the girl and not the other family members. The patient is currently under steroid substitution therapy and leads a normal life.

Discussion

This family is notable by the early age of onset of multiple neural crest tumors associated with a high propensity for malignancy and metastatic spread. Most reports in the literature associated the VHL mutation with a later onset in adulthood and a benign course, which contrast with our findings and question the role of this mutation in the phenotype expressed in this kindred. Also, the presence of concomitant mutations in two susceptibility genes for neural crest tumors poses the question of their respective roles in the development of tumors in this family. Our familial case description illustrates the potential for systematic use of targeted Next Generation Sequencing with multi-gene panels in patients with neural crest tumors to confirm the role of known susceptibility genes as well as identifying new ones, but also to contribute to comprehensive databases on gene variants and their phenotypic counterparts in this specific area of medicine.

Congenital hyperinsulinemic hypoglycemia (HH) requiring treatment as the presenting feature of Kabuki syndrome

Kabuki syndrome is a congenital condition characterized by a set of facial dysmorphic features that often help the clinician to suspect the diagnosis. However, more insidious symptoms can rarely occur, such as manifestations of hypoglycemia in newborns with congenital hyperinsulinism hypoglycemia, especially when a variant of the KDM6A gene is found. In those cases, a treatment with diazoxide can be started and can be replaced with lanreotide if a satisfying glycemic control is not achieved. We report the case of a female patient born at 37 weeks of gestational age, without any obvious facial dysmorphic features, after a non-complicated pregnancy, that presented with feeding difficulties, drowsiness, and irritability revealing a hyperinsulinemic hypoglycemia. Further testing at 6 months old found a KDM6A mutation. The patient was initially treated by diazoxide alone, but its dosage had to be lowered because of the occurrence of treatment side effects, and lanreotide had been added to maintain acceptable blood sugar levels. A congenital hyperinsulinemia hypoglycemia revealed heterozygous truncating variant in the KDM6A gene, also known as X-linked Kabuki syndrome in a newborn. In cases of neonatal hypoglycemia, the first-line therapy is diazoxide. Our report shows that analogues of somatostatin such as lanreotide should be considered if the diazoxide regimen is not tolerated.

Characterization, evolution and risk factors of diabetes and prediabetes in a pediatric cohort of renal and liver transplant recipients

BACKGROUND

Hyperglycemia (HG) and prediabetes are rarely sought in pediatric liver (LT) and renal (RT) transplantation, yet their presence indicates a high risk of diabetes and cardiovascular disease. The objectives of our DIABGRAFT study were to retrospectively (rDIABGRAFT) and longitudinally (pDIABGRAFT) characterize HG and (pre)diabetes in a cohort of children with LT or/and RT.

METHODS

We retrospectively analyzed risk factors of HG from 195 children with LT from 2012 to 2019 and twenty children with RT from 2005 to 2019 at Cliniques universitaires Saint-Luc. In addition, we prospectively followed four LT and four RT children to evaluate the evolution of their glucose metabolism.

RESULTS

Our rDIABGRAFT study showed that 25% and 35% of LT and RT children respectively presented transient HG and 20% of RT developed diabetes. The occurrence of HG was associated with the use of glucocorticoids and with acute events as graft rejection and infection. In our pDIABGRAFT cohort, biological markers of diabetes were in the normal range for HbA_1C, fasting glucose and insulin levels. However, oral glucose tolerance test and glucose sensors showed insulin resistance, impaired glucose tolerance and HG in the post-prandial afternoon period.

CONCLUSION

Our study shows that children with LT and RT were more at risk of developing HG when glucocorticoids were required and that HbA_1C and fasting glucose lack sensitivity for early detection of glucose intolerance. Also, measurement of glycemia immediately after the transplantation and in postprandial period is key to detect dysglycemia since insulin resistance prevailed in our cohort.

CLINICALTRIALSGOV ID

NCT05464043.

Influence of the occurrence and duration of partial remission on short-term metabolic control in type 1 diabetes: the DIABHONEY pediatric study

OBJECTIVE

To evaluate the residual effect of partial remission (PR) on immediate post-PR glycemic control according to its occurrence and duration in a cohort of children with type 1 diabetes mellitus (T1DM).

PATIENTS AND METHODS

Values of glycemic control parameters [i.e. HbA_1C, insulin dose-adjusted hemoglobin A_1C (IDAA_1C), glycemic target-adjusted HbA_1C (GTAA_1C)] and data from glucose monitoring devices from 189 pediatric patients with new-onset type 1 diabetes were collected retrospectively from 24 months. Patients were characterized according to their remission status (PR⁺ and PR^-). PR⁺ patients were subdivided into three subgroups regarding PR duration [i.e. short (⩾3-⩽6 months), intermediate (>6-⩽12 months), and long PR (>12-⩽14 months)]. We compared glycemic control data from each PR⁺ subgroup at +6 and +12 months post-PR with PR^- patients at the same postdiagnosis time. Second, PR⁺ subgroups were compared with each other.

RESULTS

PR⁺ patients showed improved glycemic control (i.e. HbA_1C, IDAA_1C, and GTAA_1C) at + 6 months post-PR when compared with nonremitters (PR^-), independently of the PR duration subgroups (p < 0.05). Interestingly, patients in long PR⁺ subgroup exhibited higher positive residual effect than short PR⁺ subgroup with lower GTAA_1C scores (p = 0.02), better time in range (TIR) (p = 0.003), less time in hypoglycemia (10.45 versus 16.13%, p = 0.03) and less glycemic variability (83.1 mg/dl versus 98.84 mg/dl, p = 0.03). No significant differences were found for glucose control between PR⁺ and PR^- patients at +12 months post-PR.

CONCLUSION

This study supports the positive impact of PR occurrence and duration on short-term metabolic control (better HbA_1C levels, IDAA_1C and GTAA_1C scores, TIR, and less glycemic variability) with the residual effect increasing according to PR duration.

Glycemic Variability Patterns Strongly Correlate With Partial Remission Status in Children With Newly Diagnosed Type 1 Diabetes

OBJECTIVE

To evaluate whether indexes of glycemic variability may overcome residual β-cell secretion estimates in the longitudinal evaluation of partial remission in a cohort of pediatric patients with new-onset type 1 diabetes.

RESEARCH DESIGN AND METHODS

Values of residual β-cell secretion estimates, clinical parameters (e.g., HbA1c or insulin daily dose), and continuous glucose monitoring (CGM) from 78 pediatric patients with new-onset type 1 diabetes were longitudinally collected during 1 year and cross-sectionally compared. Circadian patterns of CGM metrics were characterized and correlated to remission status using an adjusted mixed-effects model. Patients were clustered based on 46 CGM metrics and clinical parameters and compared using nonparametric ANOVA.

RESULTS

Study participants had a mean (± SD) age of 10.4 (± 3.6) years at diabetes onset, and 65% underwent partial remission at 3 months. β-Cell residual secretion estimates demonstrated weak-to-moderate correlations with clinical parameters and CGM metrics (r2 = 0.05-0.25; P < 0.05). However, CGM metrics strongly correlated with clinical parameters (r2 >0.52; P < 0.05) and were sufficient to distinguish remitters from nonremitters. Also, CGM metrics from remitters displayed specific early morning circadian patterns characterized by increased glycemic stability across days (within 63-140 mg/dL range) and decreased rate of grade II hypoglycemia (P < 0.0001) compared with nonremitters. Thorough CGM analysis allowed the identification of four novel glucotypes (P < 0.001) that segregate patients into subgroups and mirror the evolution of remission after diabetes onset.

CONCLUSIONS

In our pediatric cohort, combination of CGM metrics and clinical parameters unraveled key clinical milestones of glucose homeostasis and remission status during the first year of type 1 diabetes.

Characterization and risk factors of hyperglycaemia during treatment of childhood hematologic malignancies

BACKGROUND

Secondary forms of diabetes are often understudied and underdiagnosed in children and adolescents with cancer. The objectives of our cohort study were to study the incidence and risk factors for hyperglycaemia in leukaemia and lymphoma patients.

METHODS

We retrospectively collected 15 years of data from paediatric patients treated for acute lymphoblastic leukaemia (ALL), Hodgkin's lymphoma (HL), and non-Hodgkin's lymphoma (NHL) immediately at cancer diagnosis. We studied risk factors for hyperglycaemia in univariate and multivariate analyses.

RESULTS

Our study cohort included 267 patients corresponding to 179 patients with ALL, 48 with NHL and 40 with HL. Eighteen per cent of ALL patients (32/179) and 17% of NHL patients (8/48) developed hyperglycaemia, with more than 61% developing hyperglycaemia within the first month of treatment. No hyperglycaemia was observed in HL patients. Multivariate analysis showed the following hyperglycaemia risk factors for ALL patients: overweight or obesity (OR 3.793) and pubertal onset (OR 4.269) at cancer diagnosis, steroid-resistant disease (OR 3.445) and hematopoietic stem cell transplant (HSCT) (OR 4.754).

CONCLUSION

In our cohort, 18% of patients with ALL or NHL developed early-onset hyperglycaemia after chemotherapy/radiotherapy. Patients with ALL with increased hyperglycaemia risk can be readily identified by measuring BMI and puberty stage at cancer diagnosis. Also, glucose monitoring should be reinforced when patients show steroid-resistant disease and/or require HSCT.

Characterization of Post-Hypoglycemic Hyperglycemia in Children and Adolescents With Type 1 Diabetes: The EPHICA Study

BACKGROUND

In patients with diabetes, the dynamics in which hypoglycemia recovers impacts cardiovascular disease risk. Our study investigated the extents of "post-hypoglycemic hyperglycemia (PHH)" (i.e. hypoglycemia that recover to hyperglycemia in any circumstance) and factors likely to influence PHH characteristics in a pediatric cohort of patients with type 1 diabetes (T1D).

METHODS

We collected retrospective continuous glucose monitoring (CGM) data from 142 pediatric patients with T1D to characterize episodes of PHH during a two-month follow-up period. Factors influencing PHH were determined using univariate and multivariate analyses.

RESULTS

In our EPHICA cohort, PHH rate was 0.6 ± 0.3 episode/day and correlated (r=0.33; p<0.0001) with hyperglycemia rate (2.6 ± 0.5 episodes/day). The global proportion of hyperglycemia corresponding to PHH was 0.22 ± 0.1, yet 14.8% of patients had more than 1/3 of hyperglycemia related to PHH. Episodes of PHH lasted 239.6 ± 124.8 minutes with a hyperglycemic peak of 258.8 ± 47.1 mg/dL. Only 12.2% of PHH occurred at night. While a younger age (<12 years) and lower body mass index (BMI) (SDS: -2 to 1.6) were associated with higher daily PHH rates, teenagers (≥12 years) and obese patients experienced longer PHH and higher hyperglycemic peaks. Parameters of glycemic variability (i.e. HbA_1C, IDAA_1C and GTAA_1C) moderately correlated with PHH duration and related hyperglycemic peak. Multivariate analysis confirmed these results, as factors likely to influence PHH rate were phenotype (age and BMI) and glycemic variability parameters (time in range, mean glycemia, HbA_1C and GTAA_1C).

CONCLUSION

Our EPHICA study highlights the importance of PHH as a prominent component of hyperglycemia in some children and adolescents with T1D. Factors associated with PHH features are age, BMI and parameters of glycemic control. Young and lean children are more prone to experience hypoglycemia that recover with hyperglycemia, but adolescents and obese children tend to experience hyperglycemia of longer duration.

Effect of nationwide reimbursement of real-time continuous glucose monitoring on HbA1c, hypoglycemia and quality of life in a pediatric type 1 diabetes population: The RESCUE-pediatrics study

OBJECTIVE

Real-time continuous glucose monitoring (RT-CGM) can improve metabolic control and quality of life (QoL), but long-term real-world data in children with type 1 diabetes (T1D) are scarce. Over a period of 24 months, we assessed the impact of RT-CGM reimbursement on glycemic control and QoL in children/adolescents with T1D treated with insulin pumps.

RESEARCH DESIGN AND METHODS

We conducted a multicenter prospective observational study. Primary endpoint was the change in HbA1c. Secondary endpoints included change in time in hypoglycemia, QoL, hospitalizations for hypoglycemia and/or ketoacidosis and absenteeism (school for children, work for parents).

RESULTS

Between December 2014 and February 2019, 75 children/adolescents were followed for 12 (n = 62) and 24 months (n = 50). Baseline HbA1c was 7.2 ± 0.7% (55 ± 8mmol/mol) compared to 7.1 ± 0.8% (54 ± 9mmol/mol) at 24 months (p = 1.0). Participants with a baseline HbA1c ≥ 7.5% (n = 27, mean 8.0 ± 0.3%; 64 ± 3mmol/mol) showed an improvement at 4 months (7.6 ± 0.7%; 60 ± 8mmol/mol; p = 0.009) and at 8 months (7.5 ± 0.6%; 58 ± 7mmol/mol; p = 0.006), but not anymore thereafter (endpoint 24 months: 7.7 ± 0.9%; 61 ± 10mmol/mol; p = 0.2). Time in hypoglycemia did not change over time. QoL for parents and children remained stable. Need for assistance by ambulance due to hypoglycemia reduced from 8 to zero times per 100 patient-years (p = 0.02) and work absenteeism for parents decreased from 411 to 214 days per 100 patient-years (p = 0.03), after 24 months.

CONCLUSION

RT-CGM in pump-treated children/adolescents with T1D showed a temporary improvement in HbA1c in participants with a baseline HbA1c ≥ 7.5%, without increasing time in hypoglycemia. QoL was not affected. Importantly, RT-CGM reduced the need for assistance by ambulance due to hypoglycemia and reduced work absenteeism for parents after 24 months.

CLINICAL TRIAL REGISTRATION

[ClinicalTrials.gov], identifier [NCT02601729].

Intra-amniotic levothyroxine infusions in a case of fetal goiter due to novel Thyroglobulin gene variants

Indications and administration of intra-amniotic infusions of L-thyroxine in the context of non-immune fetal hypothyroidism with goiter lack of standardization. Systematic follow-up of clinical features related to thyroid hormonal homeostasis may be useful to evaluate their efficiency and develop standardized management guidelines.

Amiodarone-induced thyroid dysfunction in children: insights from the THYRAMIO study

BACKGROUND

Amiodarone treatment is effective against various types of arrhythmias but is associated with adverse effects affecting, among other organs, thyroid function. Amiodarone-induced thyroid dysfunction was not thoroughly evaluated in children as it was in adults, yet this affection may lead to irreversible neurodevelopmental complications. Our study aimed to define the incidence and risk factors of amiodarone-induced thyroid dysfunction in children.

METHODS

The study was designed as an observational study with a retrospective clinical series of 152 children treated by amiodarone in the Pediatric Cardiology Unit of our center from 1990 to 2019. All patients were divided into three groups according to their thyroid status: euthyroid, AIH (amiodarone-induced hypothyroidism) or AIT (amiodarone-induced thyrotoxicosis). Patients from these three groups were compared in terms of key clinical and therapeutic features.

RESULTS

Amiodarone-induced thyroid dysfunction was present in 23% of patients. AIT (5.3%) was three times less common than AIH (17.7%), and its occurrence increased with older age (p < 0.05), treatment dosage (p < 0.05), treatment duration (p < 0.05) and the number of loading doses administered (p < 0.05). There were no distinctive clinical features between euthyroid and AIH groups. A multivariable prediction model of AIT was built, with a yield of 66.7% as positive predictive value and 96.7% as negative predictive value.

CONCLUSION

We observed that one in five children developed amiodarone-induced thyroid dysfunction. Special attention is required for older children with a high dosage and long-term therapy and who received a large number of loading doses, since these children are at risk to develop AIT, which is more delicate to manage than AIH.

Benefits of physical activity in children and adolescents with type 1 diabetes: A systematic review

AIMS

We performed a systematic review of clinical trials investigating the health benefits of physical activity in pediatric patients with type 1 diabetes.

METHODS

To perform this systematic review, search strategies were created and adapted to four databases. Only randomized controlled trials written in English before 1998 and that answered to the PICOS criteria were included. The PRISMA guidelines were followed to ensure highest scientific rigor within studies.

RESULTS

Seven studies out of 2655 were included in this systematic review according to the inclusion criteria. These studies showed positive gains on global health: blood lipid profile, physical fitness, quality of life and body size and body composition but only one demonstrated a positive effect on glycemic control.

CONCLUSION

Globally, physical activity exerts a positive impact on metabolic (i.e., decrease in total cholesterol, improvement of physical fitness, etc.) and psychological health in children with type 1 diabetes. Yet variations in study protocols or sample size restrict statistical power to reach the outcome of improving glycemic control in most studies. Here, we address the measured outcomes in individual trials and discuss potential key elements to consider for future clinical trials.

Novel insights into glucocorticoid replacement therapy for pediatric and adult adrenal insufficiency

Adrenal insufficiency is defined as impaired adrenocortical hormone synthesis. According to its source, the deficit is classified as primary (adrenal steroidogenesis impairment), secondary (pituitary adrenocorticotropic hormone deficit) or tertiary (hypothalamic corticotropin-releasing hormone deficit). The management of adrenal insufficiency resides primarily in physiological replacement of glucocorticoid secretion. Standard glucocorticoid therapy is shrouded in several controversies. Along the difficulties arising from the inability to accurately replicate the pulsatile circadian cortisol rhythm, come the uncertainties of dose adjustment and treatment monitoring (absence of reliable biomarkers). Furthermore, side effects of inadequate replacement significantly hinder the quality of life of patients. Therefore, transition to circadian hydrocortisone therapy gains prominence. Recent therapeutic advancements consist of oral hydrocortisone modified-release compounds (immediate, delayed and sustained absorption formulations) or continuous subcutaneous hydrocortisone infusion. In addition to illustrating the current knowledge on conventional glucocorticoid regimens, this review outlines the latest research outcomes. We also describe the management of pediatric patients and suggest a novel strategy for glucocorticoid replacement therapy in adults.

Early Treatment with Empagliflozin and GABA Improves β-Cell Mass and Glucose Tolerance in Streptozotocin-Treated Mice

While the autoimmune character of T1D (type 1 diabetes) is being challenged, it is currently recognized that inflammation plays a key role in its development. We hypothesized that glucotoxicity could contribute to β-cell mass destruction through participation in islet inflammation. We evaluated the potential of empagliflozin (EMPA) and GABA (gamma-aminobutyric acid) to protect β-cell mass against glucotoxicity and to increase β-cell mass after diagnosis of T1D. Empagliflozin is a SGLT2 (sodium-dependent glucose cotransporter) inhibitor which thereby blocks glucose recapture by the kidney and promotes glucose excretion in urine. GABA is an inhibitory neurotransmitter, which stimulates α-to-β cell transdifferentiation. In streptozotocin-treated mice, empagliflozin and/or GABA were delivered for a period of five days or three weeks. As compared to untreated T1D mice, EMPA-treated T1D mice had decreased FFA (free fatty acid) levels and improved glucose homeostasis. EMPA-treated T1D mice had higher islet density, with preserved architecture, compared to T1D mice, and EMPA-treated T1D mice also differed from T1D mice by the total absence of immune cell infiltration within islets. Islets from EMPA-treated mice were also less subjected to ER (endoplasmic reticulum) stress and inflammation, as shown by qPCR analysis. Glucose homeostasis parameters and islet area/pancreas area ratio improved, as compared to diabetic controls, when T1D mice were treated for three weeks with GABA and EMPA. T1D EMPA+GABA mice had higher glucagon levels than T1D mice, without modifications of glucagon area/islet area ratios. In conclusion, empagliflozin and GABA, used in monotherapy in streptozotocin-induced diabetic mice, have positive effects on β-cell mass preservation or proliferation through an indirect effect on islet cell inflammation and ER stress. Further research is mandatory to evaluate whether empagliflozin and GABA may be a potential therapeutic target for the protection of β-cell mass after new-onset T1D.

Familial Forms of Cushing Syndrome in Primary Pigmented Nodular Adrenocortical Disease Presenting with Short Stature and Insidious Symptoms: A Clinical Series

Cushing syndrome (CS) is a rare disease in children, frequently associated with subtle or periodic symptoms that may delay its diagnosis. Weight gain and growth failure, the hallmarks of hypercortisolism in pediatrics, may be inconsistent, especially in ACTH-independent forms of CS. Primary pigmented nodular adrenocortical disease (PPNAD) is the rarest form of ACTH-independent CS, and can be associated with endocrine and nonendocrine tumors, forming the Carney complex (CNC). Recently, phenotype/genotype correlations have been described with particular forms of CNC where PPNAD is isolated or associated only with skin lesions. We present four familial series of CS due to isolated PPNAD, and compare them to available data from the literature. We discuss the clinical and molecular findings, and underline challenges in diagnosing PPNAD in childhood.

Integration of Routine Parameters of Glycemic Variability in a Simple Screening Method for Partial Remission in Children with Type 1 Diabetes

Although different criteria were used to define partial remission in type 1 diabetes, the IDAA1C formula has prevailed as it correlates with stimulated C-peptide levels. Our retrospective study evaluated clinical variables associated with the occurrence of IDAA1C-defined partial remission in a series of 239 pediatric patients. Diabetic ketoacidosis and age at diagnosis, but no other clinical feature, influenced the occurrence of remission. We then evaluated whether parameters of glycemic variability used in clinical routine may reliably define partial remission, as these would alleviate confounding factors related to insulin treatment. Using multiple linear regression, we observed that HbA_1C levels and percentage of normoglycemia were efficient and sufficient to predict partial remission. These parameters were entered into a formula, called glycemic target-adjusted HbA_1C (GTAA_1C), that corresponded to HbA_1C(%) - (3 × % of normoglycemic values_{(70-180 mg/dL)}). With a threshold of 4.5, this alternative formula predicted partial remission with a sensitivity and a specificity of 72.3% and 92%, respectively, and yielded strong correlation with IDAA1C levels and BETA-2 score, which is a correlate of β-cell function after islet transplantation. We propose GTAA_1C, based on routine and objective markers of glycemic variability, as a valid alternative for definition of partial remission in type 1 diabetes.

Outcomes of algorithm-based modifications of insulinotherapy during exercise in MDI vs insulin pump-treated children with type 1 diabetes: Results from the TREAD-DIAB study

OBJECTIVES

To evaluate the evolution of subcutaneous glucose (SG) after a standardized aerobic exercise in children and adolescents treated with continuous subcutaneous insulin infusion (CSII) or multiple daily injection (MDI) regimen before and after adaptation of insulin doses.

RESEARCH DESIGN AND METHODS

Eleven CSII- and 13 MDI-treated patients performed 2 30-minute sessions of moderate to vigorous (70% of age-based maximal heart rate) exercise on a treadmill under continuous glucose monitoring (CGM). First sessions were scheduled without insulin modification (TT#1) while patients performed second sessions (TT#2) after preemptive algorithm-based insulin dose modifications.

RESULTS

While insulin adaptations did not modify immediate postexercise drops in blood glucose during TT#2 in either group, CSII-treated patients had their glucose control improved during TT#2 (mean of 141 ± 56 mg/dL vs 144 ± 80 mg/dL in TT#1; P < .05) with up to 86% of SG levels within targets during 16 hours postexercise. Contrarily, SG levels did not normalize during TT#2 in MDI-treated patients who experienced higher rates of hyperglycemia during the afternoon snack. As compared with TT#1, CSII-treated patients had reduced rates of hypoglycemia during 4 hours post-TT#2 (from 19.5% to 2.1%; P < .01) and had shorter duration of nocturnal hypoglycemia (35.5 ± 12.8 vs 204.7 ± 165 minutes; P = .04) whereas in the MDI group no changes in percentages of hypoglycemia were observed during TT#2.

CONCLUSION

In our pediatric cohort, algorithmic adaptations of insulin doses were associated with better outcomes in terms of postexercise glucose control in patients with CSII therapy but not with MDI treatment.

Blood versus urine ketone monitoring in a pediatric cohort of patients with type 1 diabetes: a crossover study

BACKGROUND

The aim of our study was to determine the influence of routine ketone monitoring on hyperglycemic events (HE) and ketosis in youngsters with type 1 diabetes (T1D).

METHODS

Our single-site, controlled and randomized study was conducted on children and adolescents with T1D outside of remission phase. During two crossover periods of 6 months, patients (n = 22) experiencing HE tested ketones alternatively with a blood ketone meter or urine ketone test strips and gave their opinion on screening methods after completion of clinical trial. Moreover, we evaluated levels of awareness of ketone production in a series of 58 patients and sometimes parents via a multiple-choice questionnaire.

RESULTS

Based on self-monitoring data, patients experienced a mean of 4.8 HE/month (range 0-9.3). Patients performed accurate ketone tests more frequently during urine (46%) than during blood-testing (29%) periods (p < 0.05); while globally, 50% of ketone tests were inaccurate (i.e. without HE). Ketosis occurred significantly more often during urine (46.4%) than during blood (14.8%) monitoring (p = 0.01), although no episodes of diabetic ketoacidosis (DKA) were noticed. Duration of hyperglycemia was not different whether patients measured ketones or not, suggesting that ketone monitoring did not affect correction of glycemia. Patients evaluated blood monitoring more frequently as being practical, reliable, and useful compared with urine testing. Scores in the awareness questionnaire were globally low (36.8%) without difference between patients and their parents.

CONCLUSIONS

Although our study shows differences in outcomes (e.g. accurate use, detection of ketosis) of urine versus blood ketone monitoring, these did not affect the occurrence of HE. Whereas ketone monitoring is part of standardized diabetes education, its implementation in daily routine remains difficult, partly because patient awareness about mechanisms of ketosis is lacking.

β-cell replacement sources for type 1 diabetes: a focus on pancreatic ductal cells

Thorough research on the capacity of human islet transplantation to cure type 1 diabetes led to the achievement of 3- to 5-year-long insulin independence in nearly half of transplanted patients. Yet, translation of this technique to clinical routine is limited by organ shortage and the need for long-term immunosuppression, restricting its use to adults with unstable disease. The production of new bona fide β cells in vitro was thus investigated and finally achieved with human pluripotent stem cells (PSCs). Besides ethical concerns about the use of human embryos, studies are now evaluating the possibility of circumventing the spontaneous tumor formation associated with transplantation of PSCs. These issues fueled the search for cell candidates for β-cell engineering with safe profiles for clinical translation. In vivo studies revealed the regeneration capacity of the exocrine pancreas after injury that depends at least partially on facultative progenitors in the ductal compartment. These stimulated subpopulations of pancreatic ductal cells (PDCs) underwent β-cell transdifferentiation through reactivation of embryonic signaling pathways. In vitro models for expansion and differentiation of purified PDCs toward insulin-producing cells were described using cocktails of growth factors, extracellular-matrix proteins and transcription factor overexpression. In this review, we will describe the latest findings in pancreatic β-cell mass regeneration due to adult ductal progenitor cells. We will further describe recent advances in human PDC transdifferentiation to insulin-producing cells with potential for clinical translational studies.

V-Maf Musculoaponeurotic Fibrosarcoma Oncogene Homolog A Synthetic Modified mRNA Drives Reprogramming of Human Pancreatic Duct-Derived Cells Into Insulin-Secreting Cells

: β-Cell replacement therapy represents the most promising approach to restore β-cell mass and glucose homeostasis in patients with type 1 diabetes. Safety and ethical issues associated with pluripotent stem cells stimulated the search for adult progenitor cells with endocrine differentiation capacities. We have already described a model for expansion and differentiation of human pancreatic duct-derived cells (HDDCs) into insulin-producing cells. Here we show an innovative and robust in vitro system for large-scale production of β-like cells from HDDCs using a nonintegrative RNA-based reprogramming technique. Synthetic modified RNAs for pancreatic transcription factors (pancreatic duodenal homeobox 1, neurogenin3, and V-Maf musculoaponeurotic fibrosarcoma oncogene homolog A [MAFA]) were manufactured and daily transfected in HDDCs without strongly affecting immune response and cell viability. MAFA overexpression was efficient and sufficient to induce β-cell differentiation of HDDCs, which acquired a broad repertoire of mature β-cell markers while downregulating characteristic epithelial-mesenchymal transition markers. Within 7 days, MAFA-reprogrammed HDDC populations contained 37% insulin-positive cells and a proportion of endocrine cells expressing somatostatin and pancreatic polypeptide. Ultrastructure analysis of differentiated HDDCs showed both immature and mature insulin granules with light-backscattering properties. Furthermore, in vitro HDDC-derived β cells (called β-HDDCs) secreted human insulin and C-peptide in response to glucose, KCl, 3-isobutyl-1-methylxanthine, and tolbutamide stimulation. Transplantation of β-HDDCs into diabetic SCID-beige mice confirmed their functional glucose-responsive insulin secretion and their capacity to mitigate hyperglycemia. Our data describe a new, reliable, and fast procedure in adult human pancreatic cells to generate clinically relevant amounts of new β cells with potential to reverse diabetes.

SIGNIFICANCE

β-Cell replacement therapy represents the most promising approach to restore glucose homeostasis in patients with type 1 diabetes. This study shows an innovative and robust in vitro system for large-scale production of β-like cells from human pancreatic duct-derived cells (HDDCs) using a nonintegrative RNA-based reprogramming technique. V-Maf musculoaponeurotic fibrosarcoma oncogene homolog A overexpression was efficient and sufficient to induce β-cell differentiation and insulin secretion from HDDCs in response to glucose stimulation, allowing the cells to mitigate hyperglycemia in diabetic SCID-beige mice. The data describe a new, reliable, and fast procedure in adult human pancreatic cells to generate clinically relevant amounts of new β cells with the potential to reverse diabetes.

[Cellular therapy of diabetes: focus on the latest developments]

Islet transplantation has set the ground for diabetes cell therapy and is still undergoing various developments that might improve clinical outcomes. Alternative sources for β-cell replacement strategies are now led by human pluripotent stem cells that demonstrate near-normal β-cell features after in vitro differentiation and which can reverse diabetes in mice. Yet, their propensity for tumor formation is still unresolved. The adult pancreas is suggested as a reservoir of facultative progenitors that could represent adequate candidates for β-cell engineering, either in vivo through pharmacological treatment or after expansion in culture. This review focuses on the latest developments in protocols aiming at de novo production of functional β cells.

New Insights into Diabetes Cell Therapy

Since insulin discovery, islet transplantation was the first protocol to show the possibility to cure patients with type 1 diabetes using low-risk procedures. The scarcity of pancreas donors triggered a burst of studies focused on the production of new β cells in vitro. These were rapidly dominated by pluripotent stem cells (PSCs) demonstrating diabetes-reversal potential in diabetic mice. Subsequent enthusiasm fostered a clinical trial with immunoisolated embryonic-derived pancreatic progenitors. Yet safety is the Achilles' heel of PSCs, and a whole branch of β cell engineering medicine focuses on transdifferentiation of adult pancreatic cells. New data showed the possibility to chemically stimulate acinar or α cells to undergo β cell neogenesis and provide opportunities to intervene in situ without the need for a transplant, at least after weighing benefits against systemic adverse effects. The current studies suggested the pancreas as a reservoir of facultative progenitors (e.g., in the duct lining) could be exploited ex vivo for expansion and β cell differentiation in timely fashion and without the hurdles of PSC use. Diabetes cell therapy is thus a growing field not only with great potential but also with many pitfalls to overcome for becoming fully envisioned as a competitor to the current treatment standards.

GHRH excess and blockade in X-LAG syndrome

X-linked acrogigantism (X-LAG) syndrome is a newly described form of inheritable pituitary gigantism that begins in early childhood and is usually associated with markedly elevated GH and prolactin secretion by mixed pituitary adenomas/hyperplasia. Microduplications on chromosome Xq26.3 including the GPR101 gene cause X-LAG syndrome. In individual cases random GHRH levels have been elevated. We performed a series of hormonal profiles in a young female sporadic X-LAG syndrome patient and subsequently undertook in vitro studies of primary pituitary tumor culture following neurosurgical resection. The patient demonstrated consistently elevated circulating GHRH levels throughout preoperative testing, which was accompanied by marked GH and prolactin hypersecretion; GH demonstrated a paradoxical increase following TRH administration. In vitro, the pituitary cells showed baseline GH and prolactin release that was further stimulated by GHRH administration. Co-incubation with GHRH and the GHRH receptor antagonist, acetyl-(d-Arg(2))-GHRH (1-29) amide, blocked the GHRH-induced GH stimulation; the GHRH receptor antagonist alone significantly reduced GH release. Pasireotide, but not octreotide, inhibited GH secretion. A ghrelin receptor agonist and an inverse agonist led to modest, statistically significant increases and decreases in GH secretion, respectively. GHRH hypersecretion can accompany the pituitary abnormalities seen in X-LAG syndrome. These data suggest that the pathology of X-LAG syndrome may include hypothalamic dysregulation of GHRH secretion, which is in keeping with localization of GPR101 in the hypothalamus. Therapeutic blockade of GHRH secretion could represent a way to target the marked hormonal hypersecretion and overgrowth that characterizes X-LAG syndrome.

Clinical and genetic characterization of pituitary gigantism: an international collaborative study in 208 patients

Despite being a classical growth disorder, pituitary gigantism has not been studied previously in a standardized way. We performed a retrospective, multicenter, international study to characterize a large series of pituitary gigantism patients. We included 208 patients (163 males; 78.4%) with growth hormone excess and a current/previous abnormal growth velocity for age or final height >2 s.d. above country normal means. The median onset of rapid growth was 13 years and occurred significantly earlier in females than in males; pituitary adenomas were diagnosed earlier in females than males (15.8 vs 21.5 years respectively). Adenomas were ≥10 mm (i.e., macroadenomas) in 84%, of which extrasellar extension occurred in 77% and invasion in 54%. GH/IGF1 control was achieved in 39% during long-term follow-up. Final height was greater in younger onset patients, with larger tumors and higher GH levels. Later disease control was associated with a greater difference from mid-parental height (r=0.23, P=0.02). AIP mutations occurred in 29%; microduplication at Xq26.3 - X-linked acrogigantism (X-LAG) - occurred in two familial isolated pituitary adenoma kindreds and in ten sporadic patients. Tumor size was not different in X-LAG, AIP mutated and genetically negative patient groups. AIP-mutated and X-LAG patients were significantly younger at onset and diagnosis, but disease control was worse in genetically negative cases. Pituitary gigantism patients are characterized by male predominance and large tumors that are difficult to control. Treatment delay increases final height and symptom burden. AIP mutations and X-LAG explain many cases, but no genetic etiology is seen in >50% of cases.

β-Cell differentiation of human pancreatic duct-derived cells after in vitro expansion

β-Cell replacement therapy is a promising field of research that is currently evaluating new sources of cells for clinical use. Pancreatic epithelial cells are potent candidates for β-cell engineering, but their large-scale expansion has not been evidenced yet. Here we describe the efficient expansion and β-cell differentiation of purified human pancreatic duct cells (DCs). When cultured in endothelial growth-promoting media, purified CA19-9(+) cells proliferated extensively and achieved up to 22 population doublings over nine passages. While proliferating, human pancreatic duct-derived cells (HDDCs) downregulated most DC markers, but they retained low CK19 and SOX9 gene expression. HDDCs acquired mesenchymal features but differed from fibroblasts or pancreatic stromal cells. Coexpression of duct and mesenchymal markers suggested that HDDCs were derived from DCs via a partial epithelial-to-mesenchymal transition (EMT). This was supported by the blockade of HDDC appearance in CA19-9(+) cell cultures after incubation with the EMT inhibitor A83-01. After a differentiation protocol mimicking pancreatic development, HDDC populations contained about 2% of immature insulin-producing cells and showed glucose-unresponsive insulin secretion. Downregulation of the mesenchymal phenotype improved β-cell gene expression profile of differentiated HDDCs without affecting insulin protein expression and secretion. We show that pancreatic ducts represent a new source for engineering large amounts of β-like-cells with potential for treating diabetes.

X-linked acrogigantism syndrome: clinical profile and therapeutic responses

X-linked acrogigantism (X-LAG) is a new syndrome of pituitary gigantism, caused by microduplications on chromosome Xq26.3, encompassing the gene GPR101, which is highly upregulated in pituitary tumors. We conducted this study to explore the clinical, radiological, and hormonal phenotype and responses to therapy in patients with X-LAG syndrome. The study included 18 patients (13 sporadic) with X-LAG and microduplication of chromosome Xq26.3. All sporadic cases had unique duplications and the inheritance pattern in two families was dominant, with all Xq26.3 duplication carriers being affected. Patients began to grow rapidly as early as 2-3 months of age (median 12 months). At diagnosis (median delay 27 months), patients had a median height and weight standard deviation scores (SDS) of >+3.9 SDS. Apart from the increased overall body size, the children had acromegalic symptoms including acral enlargement and facial coarsening. More than a third of cases had increased appetite. Patients had marked hypersecretion of GH/IGF1 and usually prolactin, due to a pituitary macroadenoma or hyperplasia. Primary neurosurgical control was achieved with extensive anterior pituitary resection, but postoperative hypopituitarism was frequent. Control with somatostatin analogs was not readily achieved despite moderate to high levels of expression of somatostatin receptor subtype-2 in tumor tissue. Postoperative use of adjuvant pegvisomant resulted in control of IGF1 in all five cases where it was employed. X-LAG is a new infant-onset gigantism syndrome that has a severe clinical phenotype leading to challenging disease management.

Reprogramming Mouse Cells With a Pancreatic Duct Phenotype to Insulin-Producing β-Like Cells

Reprogramming technology has opened the possibility of converting one cell type into another by forced expression of transgenes. Transduction of adenoviral vectors encoding 3 pancreatic transcription factors, Pdx1, Ngn3, and MafA, into mouse pancreas results in direct reprogramming of exocrine cells to insulin-producing β-like cells. We hypothesized that cultured adult pancreatic duct cells could be reprogrammed to become insulin-producing β-cells by adenoviral-mediated expression of this same combination of factors. Exocrine were isolated from adult mouse insulin 1 promoter (MIP)-green fluorescent protein (GFP) transgenic mice to allow new insulin-expressing cells to be detected by GFP fluorescence. Cultured cells were transduced by an adenoviral vector carrying a polycistronic construct Ngn3/Pdx1/MafA/mCherry (Ad-M3C) or mCherry sequence alone as a control vector. In addition, the effects of glucagon-like peptide-1 (GLP-1) receptor agonist, exendin-4 (Ex-4) on the reprogramming process were examined. GFP(+) cells appeared 2 days after Ad-M3C transduction; the reprogramming efficiency was 8.6 ± 2.6% by day 4 after transduction. Ad-M3C also resulted in increased expression of β-cell markers insulin 1 and 2, with enhancement by Ex-4. Expression of other β-cell markers, neuroD and GLP-1 receptor, were also significantly up-regulated. The amount of insulin release into the media and insulin content of the cells were significantly higher in the Ad-M3C-transduced cells; this too was enhanced by Ex-4. The transduced cells did not secrete insulin in response to increased glucose, indicating incomplete differentiation to β-cells. Thus, cultured murine adult pancreatic cells with a duct phenotype can be directly reprogrammed to insulin-producing β-like cells by adenoviral delivery of 3 pancreatic transcription factors.

Gigantism and acromegaly due to Xq26 microduplications and GPR101 mutation

BACKGROUND

Increased secretion of growth hormone leads to gigantism in children and acromegaly in adults; the genetic causes of gigantism and acromegaly are poorly understood.

METHODS

We performed clinical and genetic studies of samples obtained from 43 patients with gigantism and then sequenced an implicated gene in samples from 248 patients with acromegaly.

RESULTS

We observed microduplication on chromosome Xq26.3 in samples from 13 patients with gigantism; of these samples, 4 were obtained from members of two unrelated kindreds, and 9 were from patients with sporadic cases. All the patients had disease onset during early childhood. Of the patients with gigantism who did not carry an Xq26.3 microduplication, none presented before the age of 5 years. Genomic characterization of the Xq26.3 region suggests that the microduplications are generated during chromosome replication and that they contain four protein-coding genes. Only one of these genes, GPR101, which encodes a G-protein-coupled receptor, was overexpressed in patients' pituitary lesions. We identified a recurrent GPR101 mutation (p.E308D) in 11 of 248 patients with acromegaly, with the mutation found mostly in tumors. When the mutation was transfected into rat GH3 cells, it led to increased release of growth hormone and proliferation of growth hormone-producing cells.

CONCLUSIONS

We describe a pediatric disorder (which we have termed X-linked acrogigantism [X-LAG]) that is caused by an Xq26.3 genomic duplication and is characterized by early-onset gigantism resulting from an excess of growth hormone. Duplication of GPR101 probably causes X-LAG. We also found a recurrent mutation in GPR101 in some adults with acromegaly. (Funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and others.).

Characteristics and determinants of partial remission in children with type 1 diabetes using the insulin-dose-adjusted A1C definition

To evaluate the characteristics and determinants of partial remission (PR) in Belgian children with type 1 diabetes (T1D), we analyzed records of 242 children from our center. Clinical and biological features were collected at diagnosis and during follow-up. PR was defined using the insulin-dose-adjusted A1C definition. PR occurred in 56.2% of patients and lasted 9.2 months (0.5 to 56.6). 25.6% of patients entered T1D with DKA, which correlated with lower PR incidence (17.6% versus 82.3% when no DKA). In our population, lower A1C levels at diagnosis were associated with higher PR incidence and in young children (0-4 years) initial A1C levels negatively correlated with longer PR. Early A1C levels were predictive of PR duration since 34% of patients had long PRs (>1 year) when A1C levels were ≤ 6% after 3 months whereas incidence of long PR decreased with higher A1Cs. C-peptide levels were higher in patients entering PR and remained higher until 3 years after diagnosis. Initial antibody titers did not influence PR except for anti-IA2 titers that correlated with A1C levels after 2 years. Presence of 2 versus 1 anti-islet antibodies correlated with shorter PR. PR duration did not influence occurrence of severe hypoglycemia or diabetes-related complications but was associated with lower A1C levels after 18 months. We show that, at diagnosis of T1D, parameters associated with β-cell mass reserve (A1C, C-peptide, and DKA) correlate with the occurrence of PR, which affects post-PR A1C levels. Further research is needed to determine the long-term significance of PR.

A small-molecule inducer of PDX1 expression identified by high-throughput screening

Pancreatic and duodenal homeobox 1 (PDX1), a member of the homeodomain-containing transcription factor family, is a key transcription factor important for both pancreas development and mature β cell function. The ectopic overexpression of Pdx1, Neurog3, and MafA in mice reprograms acinar cells to insulin-producing cells. We developed a quantitative PCR-based gene expression assay to screen more than 60,000 compounds for expression of each of these genes in the human PANC-1 ductal carcinoma cell line. We identified BRD7552, which upregulated PDX1 expression in both primary human islets and ductal cells, and induced epigenetic changes in the PDX1 promoter consistent with transcriptional activation. Prolonged compound treatment induced both insulin mRNA and protein and also enhanced insulin expression induced by the three-gene combination. These results provide a proof of principle for identifying small molecules that induce expression of transcription factors to control cellular reprogramming.

Making β cells from adult cells within the pancreas

Cell therapy is currently considered as a potential therapeutic alternative to traditional treatments of diabetes. Islet and whole pancreas transplantations provided the proof-of-concept of glucose homeostasis restoration after replenishment of the deficiency of β cells responsible for the disease. Current limitations of these procedures have led to the search for strategies targeting replication of pre-existing β cells or transdifferentiation of progenitors and adult cells. These investigations revealed an unexpected plasticity towards β cells of adult cells residing in pancreatic epithelium (eg, acinar, duct, and α cells). Here we discuss recent developments in β-cell replication and β-cell transdifferentiation of adult epithelial pancreatic cells, with an emphasis on techniques with a potential for clinical translation.

Islet neogenesis: a possible pathway for beta-cell replenishment

Diabetes, particularly type 1 diabetes, results from the lack of pancreatic β-cells. β-cell replenishment can functionally reverse diabetes, but two critical challenges face the field: 1. protection of the new β-cells from autoimmunity and allorejection, and 2. development of β-cells that are readily available and reliably functional. This chapter will examine the potential of endogenous replenishment of pancreatic β-cells as a possible therapeutic tool if autoimmunity could be blunted. Two pathways for endogenous replenishment exist in the pancreas: replication and neogenesis, defined as the formation of new islet cells from pancreatic progenitor/stem cells. These pathways of β-cell expansion are not mutually exclusive and both occur in embryonic development, in postnatal growth, and in response to some injuries. Since the β-cell population is dramatically reduced in the pancreas of type 1 diabetes patients, with only a small fraction of the β-cells surviving years after onset, replication of preexisting β-cells would not be a reasonable start for replenishment. However, induction of neogenesis could provide a starting population that could be further expanded by replication. It is widely accepted that neogenesis occurs in the initial embryonic formation of the endocrine pancreas, but its occurrence anytime after birth has become controversial because of discordant data from lineage tracing experiments. However, the concept was built upon many observations from different models and species over many years. Herein, we discuss the role of neogenesis in normal growth and regeneration, as learned from rodent models, followed by an analysis of what has been found in humans.

Concise review: pancreas regeneration: recent advances and perspectives

The replacement of functional pancreatic β-cells is seen as an attractive potential therapy for diabetes, because diabetes results from an inadequate β-cell mass. Inducing replication of the remaining β-cells and new islet formation from progenitors within the pancreas (neogenesis) are the most direct ways to increase the β-cell mass. Stimulation of both replication and neogenesis have been reported in rodents, but their clinical significance must still be shown. Because human islet transplantation is limited by the scarcity of donors and graft failure within a few years, efforts have recently concentrated on the use of stem cells to replace the deficient β-cells. Currently, embryonic stem cells and induced pluripotent stem cells achieve high levels of β-cell differentiation, but their clinical use is still hampered by ethical issues and/or the risk of developing tumors after transplantation. Pancreatic epithelial cells (duct, acinar, or α-cells) represent an appealing alternative to stem cells because they demonstrate β-cell differentiation capacities. Yet translation of such capacity to human cells after significant in vitro expansion has yet to be achieved. Besides providing new β-cells, cell therapy also has to address the question on how to protect the transplanted cells from destruction by the immune system via either allo- or autoimmunity. Encouraging developments have been made in encapsulation and immunomodulation techniques, but many challenges still remain. Herein, we discuss recent advances in the search for β-cell replacement therapies, current strategies for circumventing the immune system, and mandatory steps for new techniques to be translated from bench to clinics.

Two-step transplantation for primary hyperoxaluria: cadaveric liver followed by living donor related kidney transplantation

In PH, PLTX, although ideal in theory, is rarely achieved. Patients usually have reached end-stage kidney disease while requiring combined liver and kidney transplantation. In this combined procedure, the sudden high oxalates mobilization from blood and tissue stores jeopardizes the success of the kidney graft, with a high risk of post-transplant early kidney necrosis or chronic graft damage. Here, we report the case of a three-yr-old girl with PH and ESRF in whom we performed sequentially deceased donor liver transplantation followed four months later by living donor kidney transplant, after normalization of blood oxalate levels and improvement of urinary oxalate output. After this two-step transplantation, our patient showed normalization of renal function with good urinary output and maintained normal blood oxalate levels. This strategy seems to be a reasonable approach in order to avoid acute renal tubular injury because of oxalate excretion in these patients.

DNA methylation-associated repression of cancer-germline genes in human embryonic and adult stem cells

Cancer-germline (CG) genes are a particular group of germline-specific genes that rely primarily on DNA methylation for repression in somatic tissues. In a wide variety of tumors, the promoter of these genes is demethylated, and their transcription is activated. The mechanism underlying this tumor-specific activation is still unclear. It was recently suggested that CG gene expression may be a hallmark of stem cells, and that expression of these genes in several tumors may reflect the expansion of constitutively expressing cancer stem cells. To clarify this issue, we carefully evaluated the expression of several CG genes in human stem cells of embryonic and adult origin. We found no or very weak expression of CG genes in these cells. Consistently, the promoter of CG genes was highly methylated in these cells. We conclude that CG genes do not qualify as "stemness" genes, and propose that their activation in cancers results from a tumor-specific activation process.

Liver cell transplantation for Crigler-Najjar syndrome type I: Update and perspectives

Liver cell transplantation is an attractive technique to treat liver-based inborn errors of metabolism. The feasibility and efficacy of the procedure has been demonstrated, leading to medium term partial metabolic control of various diseases. Crigler-Najjar is the paradigm of such diseases in that the host liver is lacking one function with an otherwise normal parenchyma. The patient is at permanent risk for irreversible brain damage. The goal of liver cell transplantation is to reduce serum bilirubin levels within safe limits and to alleviate phototherapy requirements to improve quality of life. Preliminary data on Gunn rats, the rodent model of the disease, were encouraging and have led to successful clinical trials. Herein we report on two additional patients and describe the current limits of the technique in terms of durability of the response as compared to alternative therapeutic procedures. We discuss the future developments of the technique and new emerging perspectives.

Leukemia inhibitory factor contributes to hepatocyte-like differentiation of human bone marrow mesenchymal stem cells

The current majority of protocols for hepatocyte differentiation of mesenchymal stem cells (MSCs) are conducted using oncostatin M (OSM) as an inducer of hepatocyte-like maturation. As leukemia inhibitory factor (LIF) and OSM share similar signaling pathways, we examined whether LIF could play a role in the hepatocyte differentiation process. A differentiation protocol was designed using LIF as a maturation cytokine and this was compared with standard and control protocols applied to human MSCs of bone marrow origin. We observed that mesenchymal-derived hepatocyte-like cells (MDHLCs) acquired similar morphological changes when exposed to LIF or to OSM. Using protein and gene expression assays, we noticed a comparable hepatic marker expression in both differentiation conditions. Furthermore, LIF and OSM allowed the acquisition of equivalent levels of hepatocyte-like functionality as attested by evaluation of urea secretion and glycogen deposition. However, no increase in the expression of hepatocyte-like features could be observed in MDHLCs after a combined exposition to LIF and OSM. In conclusion, we demonstrated that LIF can play a similar role as OSM in the hepatocyte differentiation process of human MSCs.

Persistence of a chimerical phenotype after hepatocyte differentiation of human bone marrow mesenchymal stem cells

OBJECTIVES

Recent studies have suggested the potential of mesenchymal stem cells (MSCs) to differentiate into a hepatocyte-like lineage. Here, we evaluate the efficacy of hepatocyte differentiation of MSCs by studying acquisition of hepatocyte-like features together with alteration of the native mesenchymal phenotype.

MATERIAL AND METHODS

In vitro, we have investigated protein and mRNA level expression of hepatocyte and mesenchymal markers of mesenchymal-derived hepatocyte-like cells (MDHLCs) and we have evaluated their functionality using metabolic assays. In vivo, we investigated co-expression of hepatocyte (albumin, alpha-foetoprotein, cytokeratin 18) and mesenchymal (fibronectin, vimentin) markers after transplantation of MSCs or MDHLCs into severe combined immune deficiency mice.

RESULTS

We observed that while in vitro these cells acquired some phenotypic and functional features of mature hepatocytes, they partially preserved their mesenchymal phenotype. After intrasplenic transplantation, engrafted MSCs with isolated expression of fibronectin and alpha-foetoprotein were observed. When these cells were injected into the liver, they expressed all analysed markers, confirming the chimaeric co-expression observed in vitro. Conversely, liver-engrafted MDHLCs conserved their hepatocyte-lineage markers but lost their chimaeric phenotype.

CONCLUSIONS

Hepatocyte differentiation of MSCs predominantly allows the acquisition of phenotypic hallmarks and provides chimaeric cells that maintain expression of initial lineage markers. However, advanced maturation to the hepatocyte-like phenotype could be obtained in vivo by conditioning MSCs prior to transplantation or by infusing cells into the liver micro-environment.

Native umbilical cord matrix stem cells express hepatic markers and differentiate into hepatocyte-like cells

BACKGROUND & AIMS

Umbilical cord matrix stem cells (UCMSCs) are able to differentiate into mesodermal and ectodermal lineages. The present study investigates the differentiation potential of human UCMSCs into hepatic lineage.

METHODS

We isolated human UCMSCs and characterized them in vitro by measuring their expansion potential, by assessing expression of mesenchymal stem cell (MSC) markers, and by evaluating their ability to differentiate into adipocytes and osteocytes. UCMSCs were thereafter subjected to a hepatogenic differentiation protocol. Expression of hepatic and MSC markers in differentiated cells was analyzed by reverse-transcription polymerase chain reaction, flow cytometry, and immunocytochemical assays and compared with undifferentiated UCMSCs and freshly isolated liver cells. UCMSCs were transplanted into livers of hepatectomized-SCID mice, and engraftment capacity was investigated by detection of human nucleus and mitochondria and human hepatic-specific proteins.

RESULTS

In vitro expanded UCMSCs constitutively expressed markers of hepatic lineage, including albumin, alpha-fetoprotein, cytokeratin-19, connexin-32, and dipeptidyl peptidase IV. In vitro-differentiated UCMSCs exhibited hepatocyte-like morphology, up-regulated several hepatic markers, stored glycogen, produced urea, and exhibited an inducible CYP 3A4 activity. However, absence of some hepatic markers in differentiated UCMSCs, as HepPar1 or hepatocyte nuclear factor 4 (HNF-4), implied that their differentiation did not reach the level of mature hepatocytes. We also noticed that differentiated UCMSCs partially preserved MSC markers. Engraftment capacity of UCMSCs was observed, and expression of human albumin and alpha-fetoprotein was detected 2, 4, and 6 weeks after transplantation in mice livers, while cytokeratin 19 was completely down-regulated.

CONCLUSIONS

We conclude that UCMSCs, with a newly demonstrated endodermic differentiation potential, might be an alternative source for liver-directed cell therapies.

Stem cells for liver tissue repair: Current knowledge and perspectives

Stem cells from extra- or intrahepatic sources have been recently characterized and their usefulness for the generation of hepatocyte-like lineages has been demonstrated. Therefore, they are being increasingly considered for future applications in liver cell therapy. In that field, liver cell transplantation is currently regarded as a possible alternative to whole organ transplantation, while stem cells possess theoretical advantages on hepatocytes as they display higher in vitro culture performances and could be used in autologous transplant procedures. However, the current research on the hepatic fate of stem cells is still facing difficulties to demonstrate the acquisition of a full mature hepatocyte phenotype, both in vitro and in vivo. Furthermore, the lack of obvious demonstration of in vivo hepatocyte-like cell functionality remains associated to low repopulation rates obtained after current transplantation procedures. The present review focuses on the current knowledge of the stem cell potential for liver therapy. We discuss the characteristics of the principal cell candidates and the methods to demonstrate their hepatic potential in vitro and in vivo. We finally address the question of the future clinical applications of stem cells for liver tissue repair and the technical aspects that remain to be investigated.

Partial proximal 10q trisomy: a new case associated with biliary atresia

Herein we describe a unique case of partial proximal 10q trisomy presenting biliary atresia, anal anteposition and cardiac malformation. The 10q duplication was confirmed by G banding on prophase chromosomes. A review of the literature confirmed that the patient displayed characteristic dysmorphic features of the recently defined partial proximal trisomy 10q syndrome and emphasized the interindividual variability of visceral malformations.

Human skin fibroblasts: From mesodermal to hepatocyte-like differentiation

The phenotypic homology of fibroblasts and mesenchymal stem cells (MSCs) has been recently described. Our study investigated the in vitro potential of human skin fibroblasts to differentiate into mesodermal (osteocyte and adipocyte) and endodermal (hepatocyte) cell lineages by comparison with human bone marrow (hBM) MSCs. The endodermal potential of fibroblasts was then explored in vivo in a mouse model of liver injury. Fibroblasts were able to acquire osteocyte and adipocyte phenotypes as assessed by cytochemistry and gene expression analyses. After exposure to a specific differentiation cocktail, these cells presented hepatocyte-like morphology and acquired liver-specific markers on protein and gene expression levels. Furthermore, these fibroblast-derived hepatocyte-like cells (FDHLCs) displayed the ability to store glycogen and synthesize small amounts of urea. By gene expression analysis, we observed that fibroblasts remained in a mesenchymal-epithelial transition state after hepatocyte differentiation. Moreover, FDHLCs lost their hepatocyte-like phenotype after dedifferentiation. In vivo, human fibroblasts infused directly into the liver of hepatectomized severe combined immunodeficient (SCID) mice engrafted in situ and expressed hepatocyte markers (albumin, alpha-fetoprotein, and cytokeratin 18) together with the mesodermal marker fibronectin. Despite lower liver-specific marker expression, the in vitro and in vivo differentiation profile of fibroblasts was comparable to that of mesenchymal-derived hepatocyte-like cells (MDHLCs). In conclusion, our work demonstrates that human skin fibroblasts are able to display mesodermal and endodermal differentiation capacities and provides arguments that these cells share MSCs features both on the phenotypic and functional levels.