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BACKGROUND & AIMS: In addition to the Notch and Wnt signaling pathways, energy metabolism also regulates intestinal stem cell (ISC) function. Tumor suppressor and kinase STK11 (also called LKB1) regulates stem cells and cell metabolism. We investigated whether loss of LKB1 alters ISC homeostasis in mice. METHODS: We deleted LKB1 from ISCs in mice using Lgr5-regulated CRE-ERT2 (Lkb1(Lgr5-KO) mice) and the traced lineages by using a CRE-dependent TdTomato reporter. Intestinal tissues were collected and analyzed by immunohistochemical and immunofluorescence analyses. We purified ISCs and intestinal progenitors using flow cytometry and performed RNA-sequencing analysis. We measured organoid-forming capacity and ISC percentages using intestinal tissues from Lkb1(Lgr5-KO) mice. We analyzed human Ls174t cells with knockdown of LKB1 or other proteins by immunoblotting, real-time quantitative polymerase chain reaction, and the Seahorse live-cell metabolic assay. RESULTS: Some intestinal crypts from Lkb1(Lgr5-KO) mice lost ISCs compared with crypts from control mice. However, most crypts from Lkb1(Lgr5-KO) mice contained functional ISCs that expressed increased levels of Atoh1 messenger RNA (mRNA), acquired a gene expression signature associated with secretory cells, and generated more cells in the secretory lineage compared with control mice. Knockdown of LKB1 in Ls174t cells induced expression of Atoh1 mRNA and a phenotype of increased mucin production; knockdown of ATOH1 prevented induction of this phenotype. The increased expression of Atoh1 mRNA after LKB1 loss from ISCs or Ls174t cells did not involve Notch or Wnt signaling. Knockdown of pyruvate dehydrogenase kinase 4 (PDK4) or inhibition with dichloroacetate reduced the up-regulation of Atoh1 mRNA after LKB1 knockdown in Ls174t cells. Cells with LKB1 knockdown had a reduced rate of oxygen consumption, which was partially restored by PDK4 inhibition with dichloroacetate. ISCs with knockout of LKB1 increased the expression of PDK4 and had an altered metabolic profile. CONCLUSIONS: LKB1 represses transcription of ATOH1, via PDK4, in ISCs, restricting their differentiation into secretory lineages. These findings provide a connection between metabolism and the fate determination of ISCs.

Objective Pancreatic neuroendocrine tumors (panNETs) are the leading cause of death in patients with multiple endocrine neoplasia type 1 (MEN1). The role of somatostatin receptor positron emission tomography/computed tomography (SSTR PET/CT) in MEN1 has not been established. The aim was to assess pancreatic imaging in MEN1 in a real-life setting. Design Fifty-eight patients with MEN1 [median age 40 (range 16-72) years] underwent SSTR PET/CT imaging; either as a screening tool regardless of disease stage (n = 47) or to further characterize known panNETs (n = 11). SSTR PET/CT and matched conventional imaging were blindly analyzed. We assessed the findings and the impact of SSTR PET/CT during a median follow-up of 47 months. Results SSTR PET/CT detected three times as many panNETs as conventional imaging (P < .001). SSTR PET/CT altered the management of 27 patients (47%). Seven patients (12%) were referred for surgery, and five (9%) received systemic treatment. In 15/25 (60%) patients with no previous panNET (n = 22) or in remission after surgery (n = 3), SSTR PET/CT identified a panNET (n = 14) or recurrence (n = 1). In eight patients, SSTR PET/CT revealed a panNET not immediately visible on conventional imaging. During a median follow-up of 47 months, three became visible on conventional imaging, but none required intervention. When SSTR PET/CT was negative, no panNETs were identified on conventional imaging during 38 months of follow-up. Conclusions SSTR PET/CT demonstrates high accuracy in the detection of panNETs and alters the clinical management in nearly half of the MEN1-patients. SSTR PET/CT enables timely diagnosis and staging of MEN1-related panNETs.

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The morphology and functionality of the epithelial lining differ along the intestinal tract, but tissue renewal at all sites is driven by stem cells at the base of crypts(1-3). Whether stem cell numbers and behaviour vary at different sites is unknown. Here we show using intravital microscopy that, despite similarities in the number and distribution of proliferative cells with an Lgr5 signature in mice, small intestinal crypts contain twice as many effective stem cells as large intestinal crypts. We find that, although passively displaced by a conveyor-belt-like upward movement, small intestinal cells positioned away from the crypt base can function as long-term effective stem cells owing to Wnt-dependent retrograde cellular movement. By contrast, the near absence of retrograde movement in the large intestine restricts cell repositioning, leading to a reduction in effective stem cell number. Moreover, after suppression of the retrograde movement in the small intestine, the number of effective stem cells is reduced, and the rate of monoclonal conversion of crypts is accelerated. Together, these results show that the number of effective stem cells is determined by active retrograde movement, revealing a new channel of stem cell regulation that can be experimentally and pharmacologically manipulated.

Embryonic genome activation (EGA) is critical for embryonic development. However, our understanding of the regulatory mechanisms of human EGA is still incomplete. Human embryonic stem cells (hESCs) are an established model for studying developmental processes, but they resemble epiblast and are sub-optimal for modeling EGA. DUX4 regulates human EGA by inducing cleavage-stage-specific genes, while it also induces cell death. We report here that a short-pulsed expression of DUX4 in primed hESCs activates an EGA-like gene expression program in up to 17% of the cells, retaining cell viability. These DUX4-induced cells resembled eight-cell stage blastomeres and were named induced blastomere-like (iBM) cells. The iBM cells showed marked reduction of POU5F1 protein, as previously observed in mouse two-cell-like cells. Finally, the iBM cells were successfully enriched using an antibody against NaPi2b (SLC34A2), which is expressed in human blastomeres. The iBM cells provide an improved model system to study human EGA transcriptome.

Background: Sexual and physical abuse have been associated with long-term systemic alterations such as low-grade inflammation and changes in brain morphology that may be reflected in the metabolome. However, data on the metabolic consequences of sexual and physical abuse remain scarce. Objective: This pilot study sought to investigate changes in the metabolite profile related to sexual and physical abuse in depressed adolescent psychiatric outpatients. Method: The study included 76 patients aged 14-18 years, whose serum samples were analysed with a targeted metabolite profiling methodology. We estimated the associations between metabolite concentrations and the Trauma and Distress Scale (TADS) Sexual and Physical Abuse factor scores using three linear regression models (one unadjusted and two adjusted) per metabolite and trauma type pair. Additional variables in the two adjusted models were 1) the lifestyle indicators body mass index, tobacco use, and alcohol use, and 2) depression scores and the chronicity of depression. Results: TADS Sexual Abuse scores associated positively with homogentisic acid, as well as cystathionine, and negatively with choline in linear regression analysis, whereas TADS Physical Abuse scores associated negatively with AMP, choline, gamma-glutamyl cysteine and succinate, and positively with D-glucuronic acid. Conclusions: This pilot study did not include a healthy control group for comparison and the cohort was relatively small. Nevertheless, we observed alterations in metabolites related to one-carbon metabolism, mitochondrial dysfunction, oxidative stress, and inflammation in depressed patients with a history of sexual or physical abuse.

BackgroundTo investigate disease control, psychiatric comorbidity, substance use and their possible associations in adolescents with chronic medical conditions before transfer to adult healthcare.MethodsWe collected clinical data from the year preceding transfer of care and psychiatric data from the records of the paediatric hospital in Helsinki, Finland (population base 1.7 million). Participants were grouped into three disease and/or adherence control categories (good, some evidence of concern, poor) based on clinical data from the medical records of the year preceding the transfer of care. Participants completed the Adolescent’s Substance Use Measurement Questionnaire before transfer of care and were divided into four risk subgroups accordingly.ResultsIn total, 253 adolescents (mean age 17.3 years, SD 1.2) from six paediatric subspecialties participated in this study. Disease control and/or adherence were rated as good in 28% (n=70), moderate in 42% (n=105) and poor in 30% (n=76) in the year before participants transferred to adult health services. A quarter of participants had at least one psychiatric diagnosis during adolescence. Adolescents with concomitant psychiatric diagnoses more often had poor disease control of their chronic medical condition than adolescents with only a medical condition (44% vs 26%; n=25 of 59 vs 51 of 194, respectively). More than half of adolescents (56%) were abstinent or used substances infrequently; 10% (n=26) reported hazardous substance use.ConclusionsPsychiatric comorbidity in adolescents with chronic medical conditions is common. Its negative association with disease control and possible substance use should be considered in the transition process to adult health services.

Type 1 diabetes (T1D) is a disease of both autoimmunity and beta-cells. The beta-cells play an active role in their own demise by mounting defense mechanisms that are insufficient at best, and that can become even deleterious in the long term. This complex crosstalk is important to understanding the physiological defense mechanisms at play in healthy conditions, their alterations in the T1D setting, and therapeutic agents that may boost such mechanisms. Robust protocols to develop stem-cell-derived islets (SC-islets) from human pluripotent stem cells (hPSCs), and islet-reactive cytotoxic CD8(+) T-cells from peripheral blood mononuclear cells offer unprecedented opportunities to study this crosstalk. Challenges to develop in vitro beta-cell killing models include the cluster morphology of SC-islets, the relatively weak cytotoxicity of most autoimmune T-cells and the variable behavior of in vitro expanded CD8(+) T-cells. These challenges may however be highly rewarding in light of the opportunities offered by such models. Herein, we discuss these opportunities including: the beta-cell/immune crosstalk in an islet microenvironment; the features that make beta-cells more sensitive to autoimmunity; therapeutic agents that may modulate beta-cell vulnerability; and the possibility to perform analyses in an autologous setting, i.e., by generating T-cell effectors and SC-islets from the same donor.

Nicotinamide adenine dinucleotide (NAD + ) precursor nicotinamide riboside (NR) has emerged as a promising compound to improve obesity-associated mitochondrial dysfunction and metabolic syndrome in mice. However, most short-term clinical trials conducted so far have not reported positive outcomes. Therefore, we aimed to determine whether long-term NR supplementation boosts mitochondrial biogenesis and metabolic health in humans. Twenty body mass index (BMI)–discordant monozygotic twin pairs were supplemented with an escalating dose of NR (250 to 1000 mg/day) for 5 months. NR improved systemic NAD + metabolism, muscle mitochondrial number, myoblast differentiation, and gut microbiota composition in both cotwins. NR also showed a capacity to modulate epigenetic control of gene expression in muscle and adipose tissue in both cotwins. However, NR did not ameliorate adiposity or metabolic health. Overall, our results suggest that NR acts as a potent modifier of NAD + metabolism, muscle mitochondrial biogenesis and stem cell function, gut microbiota, and DNA methylation in humans irrespective of BMI.

Background Prenatal alcohol exposure (PAE) affects embryonic development, causing a variable fetal alcohol spectrum disorder (FASD) phenotype with neuronal disorders and birth defects. We hypothesize that early alcohol-induced epigenetic changes disrupt the accurate developmental programming of embryo and consequently cause the complex phenotype of developmental disorders. To explore the etiology of FASD, we collected unique biological samples of 80 severely alcohol-exposed and 100 control newborns at birth. Methods We performed genome-wide DNA methylation (DNAm) and gene expression analyses of placentas by using microarrays (EPIC, Illumina) and mRNA sequencing, respectively. To test the manifestation of observed PAE-associated DNAm changes in embryonic tissues as well as potential biomarkers for PAE, we examined if the changes can be detected also in white blood cells or buccal epithelial cells of the same newborns by EpiTYPER. To explore the early effects of alcohol on extraembryonic placental tissue, we selected 27 newborns whose mothers had consumed alcohol up to gestational week 7 at maximum to the separate analyses. Furthermore, to explore the effects of early alcohol exposure on embryonic cells, human embryonic stem cells (hESCs) as well as hESCs during differentiation into endodermal, mesodermal, and ectodermal cells were exposed to alcohol in vitro. Results DPPA4, FOXP2, and TACR3 with significantly decreased DNAm were discovered—particularly the regulatory region of DPPA4 in the early alcohol-exposed placentas. When hESCs were exposed to alcohol in vitro, significantly altered regulation of DPPA2, a closely linked heterodimer of DPPA4, was observed. While the regulatory region of DPPA4 was unmethylated in both control and alcohol-exposed hESCs, alcohol-induced decreased DNAm similar to placenta was seen in in vitro differentiated mesodermal and ectodermal cells. Furthermore, common genes with alcohol-associated DNAm changes in placenta and hESCs were linked exclusively to the neurodevelopmental pathways in the enrichment analysis, which emphasizes the value of placental tissue when analyzing the effects of prenatal environment on human development. Conclusions Our study shows the effects of early alcohol exposure on human embryonic and extraembryonic cells, introduces candidate genes for alcohol-induced developmental disorders, and reveals potential biomarkers for prenatal alcohol exposure.

Characterization of gene expression in pancreatic islets and its alteration in type 2 diabetes (T2D) are vital in understanding islet function and T2D pathogenesis. We leveraged RNA sequencing and genome-wide genotyping in islets from 188 donors to create the Islet Gene View (IGW) platform to make this information easily accessible to the scientific community. Expression data were related to islet phenotypes, diabetes status, other islet-expressed genes, islet hormone-encoding genes and for expression in insulin target tissues. The IGW web application produces output graphs for a particular gene of interest. In IGW, 284 differentially expressed genes (DEGs) were identified in T2D donor islets compared with controls. Forty percent of DEGs showed cell-type enrichment and a large proportion significantly co-expressed with islet hormone-encoding genes; glucagon (GCG, 56%), amylin (IAPP, 52%), insulin (INS, 44%), and somatostatin (SST, 24%). Inhibition of two DEGs,UNC5DandSERPINE2, impaired glucose-stimulated insulin secretion and impacted cell survival in a human β-cell model. The exploratory use of IGW could help designing more comprehensive functional follow-up studies and serve to identify therapeutic targets in T2D.

IntroductionConstitutional delay of growth and puberty (CDGP) is the most common reason for delayed puberty in healthy male adolescents. The main indication for medical treatment for this condition is psychosocial burden. However, to the best of our knowledge, no previous study has addressed the impact of puberty-promoting treatment on health-related quality of life (HRQoL) among boys with CDGP.MethodsWe investigated HRQoL in 22 boys with CDGP, who participated in a randomized controlled trial in four Finnish pediatric endocrinology outpatient clinics between 2013 and 2017. The boys were randomized to receive either aromatase inhibitor letrozole (2.5mg/day; n=11) or intramuscular testosterone (1mg/kg/every 4 weeks; n=11) for 6 months and followed up to 12 months. HRQoL was assessed with a generic self-assessment 16D© instrument developed and validated for adolescents aged 12 to 15 years. The 16D includes 16 dimensions (vitality, sight, breathing, distress, hearing, sleeping, eating, discomfort and symptoms, speech, physical appearance, school and hobbies, mobility, friends, mental function, excretion and depression). The results were compared with an age-matched reference population that included 163 boys from the Finnish capital-city area. The study protocol is registered to ClinicalTrials.gov (registration number: NCT01797718).ResultsAt baseline, the mean 16D score of the CDGP boys was similar to the age-matched reference population (0.95 vs 0.96, p=0.838). However, the physical appearance score (satisfaction with general appearance, height and weight) was significantly lower in the CDGP boys (0.75 vs 0.92, p=0.004) than their peers. Twelve months after treatment, Appearance had improved significantly (0.75 vs 0.87, p=0.004) and no HRQoL dimension was inferior compared to the age-matched reference population.DiscussionIn terms of HRQoL, the main impact of delayed puberty was dissatisfaction with physical appearance. Puberty promoting therapy was associated with a positive change in perceived appearance, with no clear difference between low-dose testosterone and letrozole treatments.

Rhabdomyolysis is the acute breakdown of skeletal myofibres in response to an initiating factor, most commonly toxins and over exertion. A variety of genetic disorders predispose to rhabdomyolysis through different pathogenic mechanisms, particularly in patients with recurrent episodes. However, most cases remain without a genetic diagnosis. Here we present six patients who presented with severe and recurrent rhabdomyolysis, usually with onset in the teenage years; other features included a history of myalgia and muscle cramps. We identified 10 bi-allelic loss-of-function variants in the gene encoding obscurin (OBSCN) predisposing individuals to recurrent rhabdomyolysis. We show reduced expression of OBSCN and loss of obscurin protein in patient muscle. Obscurin is proposed to be involved in sarcoplasmic reticulum function and Ca2+ handling. Patient cultured myoblasts appear more susceptible to starvation as evidenced by a greater decreased in sarcoplasmic reticulum Ca2+ content compared to control myoblasts. This likely reflects a lower efficiency when pumping Ca2+ back into the sarcoplasmic reticulum and/or a decrease in Ca2+ sarcoplasmic reticulum storage ability when metabolism is diminished. OSBCN variants have previously been associated with cardiomyopathies. None of the patients presented with a cardiomyopathy and cardiac examinations were normal in all cases in which cardiac function was assessed. There was also no history of cardiomyopathy in first degree relatives, in particular in any of the carrier parents. This cohort is relatively young, thus follow-up studies and the identification of additional cases with bi-allelic null OBSCN variants will further delineate OBSCN-related disease and the clinical course of disease. Cabrera-Serrano et al. show that biallelic loss-of-function variants in the gene encoding obscurin (OBSCN) predispose individuals to recurrent and severe episodes of rhabdomyolysis, typically with onset in the teenage years.

Objective: Klinefelter syndrome (KS) (47,XXY and variants, KS) is the most common sex chromosome disorder in humans. However, little is known about the onset and progression of puberty in patients with KS. In this study, we describe the onset and progression of puberty in a large series of boys with KS in a single tertiary centre. Design and Patients: Retrospective data (Tanner stages, testicular length, testosterone supplementation, levels of luteinizing hormone [LH] and testosterone) before possible testosterone treatment on 72 KS patients with 47,XXY karyotype were reviewed, and G (n = 59 patients) and P (n = 56 patients) stages were plotted on puberty nomograms. Measurements and Results: One boy had a delayed onset of puberty, as he was at the G1 stage at the age of 13.8 years (-2.2 SDs). No observations of delay were made of boys at Stage G2. The progression of G stages was within normal limits in the majority of patients; only few boys were late at G3 (4.1%; 1 out of 24) and G4 (7.4%; 2 out of 27). Testosterone supplementation was started at the average age of 15.5 years to 35 boys (47%), 2 of whom were over 18 years old. LH level was on average 18.2 IU/L (SD: 6.3 IU/L) and testosterone 9.1 nmol/L (SD: 3.1 nmol/L) when testosterone supplementation was started. Conclusions: Our results suggest that puberty starts within the normal age limits in boys with KS, and testosterone supplementation is not needed for the initial pubertal progression in the majority of patients.

Objectives Clinical diagnostics in adults with hereditary neurological diseases is complicated by clinical and genetic heterogeneity, as well as lifestyle effects. Here, we evaluate the effectiveness of exome sequencing and clinical costs in our difficult-to-diagnose adult patient cohort. Additionally, we expand the phenotypic and genetic spectrum of hereditary neurological disorders in Finland. Methods We performed clinical exome sequencing (CES) to 100 adult patients from Finland with neurological symptoms of suspected genetic cause. The patients were classified as myopathy (n = 57), peripheral neuropathy (n = 16), ataxia (n = 15), spastic paraplegia (n = 4), Parkinsonism (n = 3), and mixed (n = 5). In addition, we gathered the costs of prior diagnostic work-up to retrospectively assess the cost-effectiveness of CES as a first-line diagnostic tool. Results The overall diagnostic yield of CES was 27%. Pathogenic variants were found for 14 patients (in genes ANO5, CHCHD10, CLCN1, DES, DOK7, FKBP14, POLG, PYROXD1, SCN4A, TUBB3, and TTN) and likely pathogenic previously undescribed variants for 13 patients (in genes ABCD1, AFG3L2, ATL1, CACNA1A, COL6A1, DYSF, IRF2BPL, KCNA1, MT-ATP6, SAMD9L, SGCB, and TPM2). Age of onset below 40 years increased the probability of finding a genetic cause. Our cost evaluation of prior diagnostic work-up suggested that early CES would be cost-effective in this patient group, in which diagnostic costs increase linearly with prolonged investigations. Conclusions Based on our results, CES is a cost-effective, powerful first-line diagnostic tool in establishing the molecular diagnosis in adult neurological patients with variable symptoms. Importantly, CES can markedly shorten the diagnostic odysseys of about one third of patients.

Niche-derived factors regulate tissue stem cells, but apart from the mechanosensory pathways, the effect of niche geometry is not well understood. We used organoids and bioengineered tissue culture platforms to demonstrate that the conical shape of Lgr5 + small intestinal stem cells (ISCs) facilitate their self-renewal and function. Inhibition of non-muscle myosin II (NM II)–driven apical constriction altered ISC shape and reduced niche curvature and stem cell capacity. Niche curvature is decreased in aged mice, suggesting that suboptimal interactions between old ISCs and their niche develop with age. We show that activation of NM IIC or physical restriction to young topology improves in vitro regeneration by old epithelium. We propose that the increase in lateral surface area of ISCs induced by apical constriction promotes interactions between neighboring cells, and the curved topology of the intestinal niche has evolved to maximize signaling between ISCs and neighboring cells.

Effective protein import from cytosol is critical for mitochondrial functions and metabolic regulation. We describe here the mammalian muscle-specific and systemic consequences to disrupted mitochondrial matrix protein import by targeted deletion of the mitochondrial HSP70 co-chaperone GRPEL1. Muscle-specific loss of GRPEL1 caused rapid muscle atrophy, accompanied by shut down of oxidative phosphorylation and mitochondrial fatty acid oxidation, and excessive triggering of proteotoxic stress responses. Transcriptome analysis identified new responders to mitochondrial protein import toxicity, such as the neurological disease-linked intermembrane space protein CHCHD10. Besides communication with ER and nucleus, we identified crosstalk of distressed mitochondria with peroxisomes, in particular the induction of peroxisomal Acyl-CoA oxidase 2 (ACOX2), which we propose as an ATF4-regulated peroxisomal marker of integrated stress response. Metabolic profiling indicated fatty acid enrichment in muscle, a shift in TCA cycle intermediates in serum and muscle, and dysregulated bile acids. Our results demonstrate the fundamental importance of GRPEL1 and provide a robust model for detecting mammalian inter-organellar and systemic responses to impaired mitochondrial matrix protein import and folding.

Publisher Copyright: © 2022. Published by The Company of Biologists Ltd. Isolated populations have been valuable for the discovery of rare monogenic diseases and their causative genetic variants. Finnish disease heritage (FDH) is an example of a group of hereditary monogenic disorders caused by single major, usually autosomal-recessive, variants enriched in the population due to several past genetic drift events. Interestingly, distinct subpopulations have remained in Finland and have maintained their unique genetic repertoire. Thus, FDH diseases have persisted, facilitating vigorous research on the underlying molecular mechanisms and development of treatment options. This Review summarizes the current status of FDH, including the most recently discovered FDH disorders, and introduces a set of other recently identified diseases that share common features with the traditional FDH diseases. The Review also discusses a new era for population-based studies, which combine various forms of big data to identify novel genotype-phenotype associations behind more complex conditions, as exemplified here by the FinnGen project. In addition to the pathogenic variants with an unequivocal causative role in the disease phenotype, several risk alleles that correlate with certain phenotypic features have been identified among the Finns, further emphasizing the broad value of studying genetically isolated populations.

Publisher Copyright: © 2022 The Authors Background: Childhood-onset combined pituitary hormone deficiency (CPHD) has a wide spectrum of etiologies and genetic causes for congenital disease. We aimed to describe the clinical spectrum and genetic etiologies of CPHD in a single tertiary center and estimate the population-level incidence of congenital CPHD. Methods: The retrospective clinical cohort comprised 124 CPHD patients (48 with congenital CPHD) treated at the Helsinki University Hospital (HUH) Children's Hospital between 1985 and 2018. Clinical data were collected from the patient charts. Whole exome sequencing was performed in 21 patients with congenital CPHD of unknown etiology. Findings: The majority (61%;76/124) of the patients had acquired CPHD, most frequently due to craniopharyngiomas and gliomas. The estimated incidence of congenital CPHD was 1/16 000 (95%CI, 1/11 000-1/24 000). The clinical presentation of congenital CPHD in infancy included prolonged/severe neonatal hypoglycaemia, prolonged jaundice, and/or micropenis/bilateral cryptorchidism in 23 (66%) patients; despite these clinical cues, only 76% of them were referred to endocrine investigations during the first year of life. The median delay between the first violation of the growth screening rules and the initiation of GH Rx treatment among all congenital CPHD patients was 2·2 years, interquartile range 1·2–3·7 years. Seven patients harbored pathogenic variants in PROP1, SOX3, TBC1D32, OTX2, and SOX2, and one patient carried a likely pathogenic variant in SHH (c.676G>A, p.(Ala226Thr)). Interpretation: Our study suggests that congenital CPHD can occur in 1/16 000 children, and that patients frequently exhibit neonatal cues of hypopituitarism and early height growth deflection. These results need to be corroborated in future studies and might inform clinical practice. Funding: Päivikki and Sakari Sohlberg Foundation, Biomedicum Helsinki Foundation, and Emil Aaltonen Foundation research grants.

ObjectiveTo determine whether the timing of puberty associates with school performance.MethodsGrowth data on 13,183 children born between 1997 and 2002, were collected from child health clinics and school healthcare and school performance data from school records. Age at peak height velocity (PHV) marked pubertal timing. The relationships between age at PHV and average grades in mathematics, native language, English, and physical education from school years 6 (end of elementary school; age 11-12 years), 7 (start of middle school; 12-13 years), and 9 (end of middle school; 14-15 years) were modeled using generalized estimating equations and linear mixed models, adjusted for the month of birth and annual income and education levels in school catchment areas.ResultsThe mean (SD) age at PHV was 13.54 (1.17) years in boys and 11.43 (1.18) years in girls. In girls, age at PHV was associated with grades in mathematics (β=0.041–0.062, pConclusionsIn both sexes, the timing of puberty was associated with the grades in physical education, and in girls, with academic achievement. The decrease in boys’ mathematics grades and sex difference in academic achievement were unexplained by the timing of puberty.

Objective The hybrid close-loop system (HCL) is a rapidly emerging treatment method for type 1 diabetes (T1D), but the long-term effectiveness of the system remains unclear. This study investigates the influence of the HCL on glycemic control in children and adolescents with T1D in a real-life setting during the first year on HCL. Research design and methods This retrospective study included all the patients (n = 111) aged 3 to 16 years with T1D who initiated the HCL system between 1st of December 2018 and 1st of December 2019 in the Helsinki University Hospital. Time in range (TIR), HbA1c, mean sensor glucose (SG) value, time below range (TBR), and SG coefficient of variance (CV) were measured at 0, 1, 3, 6, and 12 month. The changes over time were analyzed with a repeated mixed model adjusted with baseline glycemic control. Results After the initiation of HCL, all measures of glycemic control, except HbA1c, improved and the effect lasted throughout the study period. Between 0 and 12 month, TIR increased (beta = -2.5 [95%CI: -3.6 - (-1.3)], p < 0.001), whereas mean SG values (beta = -0.7 [95%CI: -0.9 - (-0.4)]), TBR (beta = -2.5 [95%CI: -3.6 - (-1.3)]), and SG CV (beta = -4.5 [95%CI: -6.3 - [-2.8]) decreased significantly (p < 0.001). Importantly, the changes occurred regardless of the age of the patient. Conclusions Measurements of glycemic control, except HbA1c, improved significantly after the initiation of the HCL system and the favorable effect lasted throughout the follow-up. These results support the view that HCL is an efficacious treatment modality for children and adolescents with T1D of all ages.

Objective The role of miRNA as endocrine regulators is emerging, and microRNA mir-30b has been reported to repress Mkrn3. However, the expression of miR-30b during male puberty has not been studied. Design and methods Circulating relative miR-30b expression was assessed in sera of 26 boys with constitutional delay of growth and puberty (CDGP), treated with low-dose testosterone (T) (n =11) or aromatase inhibitor letrozole (Lz) (n =15) for 6 months and followed up to 12 months (NCT01797718). The associations between the relative expression of miR-30b and hormonal markers of puberty were evaluated. Results During the 12 months of the study, circulating miR-30b expression increased 2.4 ± 2.5 (s.d.) fold (P = 0.008) in all boys, but this change did not correlate with corresponding changes in LH, testosterone, inhibin B, FSH, or testicular volume (P = 0.25-0.96). Lz-induced activation of the hypothalamic–pituitary–gonadal (HPG) axis was associated with more variable miR-30b responses at 3 months (P < 0.05), whereas those treated with T exhibited significant changes in relative miR-30b levels in the course the study (P < 0.01–0.05). Conclusions Circulating miR-30b expression in boys with CDGP increases in the course of puberty, and appears to be related to the activity of the HPG axis.

Aims/hypothesis Monogenic forms of diabetes (MODY, neonatal diabetes mellitus and syndromic forms) are rare, and affected individuals may be misclassified and treated suboptimally. The prevalence of type 1 diabetes is high in Finnish children but systematic screening for monogenic diabetes has not been conducted. We assessed the prevalence and clinical manifestations of monogenic diabetes in children initially registered with type 1 diabetes in the Finnish Pediatric Diabetes Register (FPDR) but who had no type 1 diabetes-related autoantibodies (AABs) or had only low-titre islet cell autoantibodies (ICAs) at diagnosis. Methods The FPDR, covering approximately 90% of newly diagnosed diabetic individuals aged ≤15 years in Finland starting from 2002, includes data on diabetes-associated HLA genotypes and AAB data (ICA, and autoantibodies against insulin, GAD, islet antigen 2 and zinc transporter 8) at diagnosis. A next generation sequencing gene panel including 42 genes was used to identify monogenic diabetes. We interpreted the variants in HNF1A by using the gene-specific standardised criteria and reported pathogenic and likely pathogenic findings only. For other genes, we also reported variants of unknown significance if an individual’s phenotype suggested monogenic diabetes. Results Out of 6482 participants, we sequenced DNA for 152 (2.3%) testing negative for all AABs and 49 (0.8%) positive only for low-titre ICAs (ICAlow). A monogenic form of diabetes was revealed in 19 (12.5%) of the AAB-negative patients (14 [9.2%] had pathogenic or likely pathogenic variants) and two (4.1%) of the ICAlow group. None had ketoacidosis at diagnosis or carried HLA genotypes conferring high risk for type 1 diabetes. The affected genes were GCK, HNF1A, HNF4A, HNF1B, INS, KCNJ11, RFX6, LMNA and WFS1. A switch from insulin to oral medication was successful in four of five patients with variants in HNF1A, HNF4A or KCNJ11. Conclusions/interpretation More than 10% of AAB-negative children with newly diagnosed diabetes had a genetic finding associated with monogenic diabetes. Because the genetic diagnosis can lead to major changes in treatment, we recommend referring all AAB-negative paediatric patients with diabetes for genetic testing. Low-titre ICAs in the absence of other AABs does not always indicate a diagnosis of type 1 diabetes. Graphical abstract

Publisher Copyright: © 2022 The Author(s) We present here a robust and reliable protocol by which to differentiate pancreatic islet-like aggregates (SC-islets) from human pluripotent stem cells. The 7-stage protocol mimics developmental patterning factors that induce endocrine lineage formation and spans monolayer, microwell, and aggregate suspension culture. The SC-islets demonstrate dynamic glucose-sensitive insulin secretion and an endocrine cell composition similar to those of primary human islets. SC-islets generated using this optimized protocol are suitable for in vitro modeling of islet cell pathophysiology and therapeutic applications. For complete details on the use and execution of this protocol, please refer to Balboa et al. (2022).

Aims/HypothesisCaused by biallelic mutations of the gene encoding the transcription factor RFX6, the rare Mitchell–Riley syndrome (MRS) comprises neonatal diabetes, pancreatic hypoplasia, gallbladder agenesis or hypoplasia, duodenal atresia, and severe chronic diarrhea. So far, sixteen cases have been reported, all with a poor prognosis. This study discusses the multidisciplinary intensive clinical management of 4 new cases of MRS that survived over the first 2 years of life. Moreover, it demonstrates how the mutations impair the RFX6 function.MethodsClinical records were analyzed and described in detail. The functional impact of two RFX6R181W and RFX6V506G variants was assessed by measuring their ability to transactivate insulin transcription and genes that encode the L-type calcium channels required for normal pancreatic beta-cell function.ResultsAll four patients were small for gestational age (SGA) and prenatally diagnosed with duodenal atresia. They presented with neonatal diabetes early in life and were treated with intravenous insulin therapy before switching to subcutaneous insulin pump therapy. All patients faced recurrent hypoglycemic episodes, exacerbated when parenteral nutrition (PN) was disconnected. A sensor-augmented insulin pump therapy with a predictive low-glucose suspension system was installed with good results. One patient had a homozygous c.1517T>G (p.Val506Gly) mutation, two patients had a homozygous p.Arg181Trp mutation, and one patient presented with new compound heterozygosity. The RFX6V506G and RFX6R181W mutations failed to transactivate the expression of insulin and genes that encode L-type calcium channel subunits required for normal pancreatic beta-cell function.Conclusions/InterpretationMultidisciplinary and intensive disease management improved the clinical outcomes in four patients with MRS, including adjustment of parenteral/oral nutrition progression and advanced diabetes technologies. A better understanding of RFX6 function, in both intestine and pancreas cells, may break ground in new therapies, particularly regarding the use of drugs that modulate the enteroendocrine system.

Publisher Copyright: © 2022 The Author(s) MASTL is a mitotic accelerator with an emerging role in breast cancer progression. However, the mechanisms behind its oncogenicity remain largely unknown. Here, we identify a previously unknown role and eminent expression of MASTL in stem cells. MASTL staining from a large breast cancer patient cohort indicated a significant association with β3 integrin, an established mediator of breast cancer stemness. MASTL silencing reduced OCT4 levels in human pluripotent stem cells and OCT1 in breast cancer cells. Analysis of the cell-surface proteome indicated a strong link between MASTL and the regulation of TGF-β receptor II (TGFBR2), a key modulator of TGF-β signaling. Overexpression of wild-type and kinase-dead MASTL in normal mammary epithelial cells elevated TGFBR2 levels. Conversely, MASTL depletion in breast cancer cells attenuated TGFBR2 levels and downstream signaling through SMAD3 and AKT pathways. Taken together, these results indicate that MASTL supports stemness regulators in pluripotent and cancerous stem cells.

The ability to maintain normoglycaemia, through glucose-sensitive insulin release, is a key aspect of postnatal beta cell function. However, terminally differentiated beta cell identity does not necessarily imply functional maturity. Beta cell maturation is therefore a continuation of beta cell development, albeit a process that occurs postnatally in mammals. Although many important features have been identified in the study of beta cell maturation, as of yet no unified mechanistic model of beta cell functional maturity exists. Here, we review recent findings about the underlying mechanisms of beta cell functional maturation. These findings include systemic hormonal and nutritional triggers that operate through energy-sensing machinery shifts within beta cells, resulting in primed metabolic states that allow for appropriate glucose trafficking and, ultimately, insulin release. We also draw attention to the expansive synergistic nature of these pathways and emphasise that beta cell maturation is dependent on overlapping regulatory and metabolic networks.

Background MAPK/ERK signaling is a well-known mediator of extracellular stimuli controlling intracellular responses to growth factors and mechanical cues. The critical requirement of MAPK/ERK signaling for embryonic stem cell maintenance is demonstrated, but specific functions in progenitor regulation during embryonic development, and in particular kidney development remain largely unexplored. We previously demonstrated MAPK/ERK signaling as a key regulator of kidney growth through branching morphogenesis and normal nephrogenesis where it also regulates progenitor expansion. Here, we performed RNA sequencing-based whole-genome expression analysis to identify transcriptional MAPK/ERK targets in two distinct renal populations: the ureteric bud epithelium and the nephron progenitors. Results Our analysis revealed a large number (5053) of differentially expressed genes (DEGs) in nephron progenitors and significantly less (1004) in ureteric bud epithelium, reflecting likely heterogenicity of cell types. The data analysis identified high tissue-specificity, as only a fraction (362) of MAPK/ERK targets are shared between the two tissues. Tissue-specific MAPK/ERK targets participate in the regulation of mitochondrial energy metabolism in nephron progenitors, which fail to maintain normal mitochondria numbers in the MAPK/ERK-deficient tissue. In the ureteric bud epithelium, a dramatic decline in progenitor-specific gene expression was detected with a simultaneous increase in differentiation-associated genes, which was not observed in nephron progenitors. Our experiments in the genetic model of MAPK/ERK deficiency provide evidence that MAPK/ERK signaling in the ureteric bud maintains epithelial cells in an undifferentiated state. Interestingly, the transcriptional targets shared between the two tissues studied are over-represented by histone genes, suggesting that MAPK/ERK signaling regulates cell cycle progression and stem cell maintenance through chromosome condensation and nucleosome assembly. Conclusions Using tissue-specific MAPK/ERK inactivation and RNA sequencing in combination with experimentation in embryonic kidneys, we demonstrate here that MAPK/ERK signaling maintains ureteric bud tip cells, suggesting a regulatory role in collecting duct progenitors. We additionally deliver new mechanistic information on how MAPK/ERK signaling regulates progenitor maintenance through its effects on chromatin accessibility and energy metabolism.

Aims/hypothesis Congenital hyperinsulinism caused by mutations in the K-ATP-channel-encoding genes (KATPHI) is a potentially life-threatening disorder of the pancreatic beta cells. No optimal medical treatment is available for patients with diazoxide-unresponsive diffuse KATPHI. Therefore, we aimed to create a model of KATPHI using patient induced pluripotent stem cell (iPSC)-derived islets. Methods We derived iPSCs from a patient carrying a homozygous ABCC8(V187D) mutation, which inactivates the sulfonylurea receptor 1 (SUR1) subunit of the K-ATP-channel. CRISPR-Cas9 mutation-corrected iPSCs were used as controls. Both were differentiated to stem cell-derived islet-like clusters (SC-islets) and implanted into NOD-SCID gamma mice. Results SUR1-mutant and -corrected iPSC lines both differentiated towards the endocrine lineage, but SUR1-mutant stem cells generated 32% more beta-like cells (SC-beta cells) (64.6% vs 49.0%, p = 0.02) and 26% fewer alpha-like cells (16.1% vs 21.8% p = 0.01). SUR1-mutant SC-beta cells were 61% more proliferative (1.23% vs 0.76%, p = 0.006), and this phenotype could be induced in SUR1-corrected cells with pharmacological K-ATP-channel inactivation. The SUR1-mutant SC-islets secreted 3.2-fold more insulin in low glucose conditions (0.0174% vs 0.0054%/min, p = 0.0021) and did not respond to K-ATP-channel-acting drugs in vitro. Mice carrying grafts of SUR1-mutant SC-islets presented with 38% lower fasting blood glucose (4.8 vs 7.7 mmol/l, p = 0.009) and their grafts failed to efficiently shut down insulin secretion during induced hypoglycaemia. Explanted SUR1-mutant grafts displayed an increase in SC-beta cell proportion and SC-beta cell nucleomegaly, which was independent of proliferation. Conclusions/interpretation We have created a model recapitulating the known pathophysiology of KATPHI both in vitro and in vivo. We have also identified a novel role for K-ATP-channel activity during human islet development. This model will enable further studies for the improved understanding and clinical management of KATPHI without the need for primary patient tissue.

Non

Techniques to acquire and analyze biological images are central to life science. However, the workflow downstream of imaging can be complex and involve several tools, leading to creation of very specialized scripts and pipelines that are difficult to reproduce by other users. Although many commercial and open-source software are available, non-expert users are often challenged by a knowledge gap in setting up analysis pipelines and selecting correct tools for extracting data from images. Moreover, a significant share of everyday image analysis requires simple tools, such as precise segmentation, cell counting, and recording of fluorescent intensities. Hence, there is a need for user-friendly platforms for everyday image analysis that do not require extensive prior knowledge on bioimage analysis or coding. We set out to create a bioimage analysis software that has a straightforward interface and covers common analysis tasks such as object segmentation and analysis, in a practical, reproducible, and modular fashion. We envision our software being useful for analysis of cultured cells, histological sections, and high-content data.

Carbohydrates, proteins and lipids are essential nutrients to all animals; however, closely related species, populations, and individuals can display dramatic variation in diet. Here we explore the variation in macronutrient tolerance in Drosophila melanogaster using the Drosophila genetic reference panel, a collection of ~200 strains derived from a single natural population. Our study demonstrates that D. melanogaster, often considered a “dietary generalist”, displays marked genetic variation in survival on different diets, notably on high-sugar diet. Our genetic analysis and functional validation identify several regulators of macronutrient tolerance, including CG10960/GLUT8, Pkn and Eip75B. We also demonstrate a role for the JNK pathway in sugar tolerance and de novo lipogenesis. Finally, we report a role for tailless, a conserved orphan nuclear hormone receptor, in regulating sugar metabolism via insulin-like peptide secretion and sugar-responsive CCHamide-2 expression. Our study provides support for the use of nutrigenomics in the development of personalized nutrition.

Mutations in mitochondrial DNA encoded subunit of ATP synthase, MT-ATP6, are frequent causes of neurological mitochondrial diseases with a range of phenotypes from Leigh syndrome and NARP to ataxias and neuropathies. Here we investigated the functional consequences of an unusual heteroplasmic truncating mutation m.9154C>T in MT-ATP6, which caused peripheral neuropathy, ataxia and IgA nephropathy. ATP synthase not only generates cellular ATP, but its dimerization is required for mitochondrial cristae formation. Accordingly, the MT-ATP6 truncating mutation impaired the assembly of ATP synthase and disrupted cristae morphology, supporting our molecular dynamics simulations that predicted destabilized a/c subunit subcomplex. Next, we modeled the effects of the truncating mutation using patient-specific induced pluripotent stem cells. Unexpectedly, depending on mutation heteroplasmy level, the truncation showed multiple threshold effects in cellular reprogramming, neurogenesis and in metabolism of mature motor neurons (MN). Interestingly, MN differentiation beyond progenitor stage was impaired by Notch hyperactivation in the MT-ATP6 mutant, but not by rotenone-induced inhibition of mitochondrial respiration, suggesting that altered mitochondrial morphology contributed to Notch hyperactivation. Finally, we also identified a lower mutation threshold for a metabolic shift in mature MN, affecting lactate utilization, which may be relevant for understanding the mechanisms of mitochondrial involvement in peripheral motor neuropathies. These results establish a critical and disease-relevant role for ATP synthase in human cell fate decisions and neuronal metabolism.

Context Circulating levels of liver-enriched antimicrobial peptide 2 (LEAP2), a ghrelin receptor antagonist, decrease under caloric restriction and increase in obesity. The role of LEAP2 in male puberty, a phase with accelerated energy demand, is unclear. Objective This work aimed to investigate whether circulating LEAP2 levels are downregulated in boys following the onset of puberty to respond to the energy need required for growth. Methods We determined circulating LEAP2 levels in 28 boys with constitutional delay of growth and puberty (CDGP) who participated in a randomized controlled trial (NCT01797718), and were treated with letrozole (n = 15) or intramuscular low-dose testosterone (T) (n = 13) for 6 months. Blood sampling and dual-energy x-ray absorptiometry–measured body composition were performed at 0-, 6-, and 12-month visits. Results Serum LEAP2 levels decreased statistically significantly during pubertal progression (0-6 months: mean decrease –4.3 [10.3] ng/mL, P = .036 and 0-12 months: –3.9 [9.3] ng/mL, P = .033). Between 0 and 6 months, the changes in serum LEAP2 levels correlated positively with changes in percentage of body fat (rs = 0.48, P = .011), and negatively with growth velocity and estradiol levels (rs = –0.43, P = .022, rs = –0.55, P = .003, respectively). In the T group only, the changes in serum LEAP2 correlated negatively with changes in T and estradiol levels. Between 0 and 12 months, the change in LEAP2 levels correlated negatively with the change in high-density lipoprotein levels (rs = –0.44, P = .022) and positively with the change in insulin (rs = 0.50, P = .009) and HOMA-IR (rs = 0.51, P = .007) levels. Conclusion Circulating LEAP2 levels decreased after induction of puberty reciprocally with increased growth rate and energy demand, reflecting the metabolic state of the adolescent. Further, the results suggest that estradiol levels may have a permissive role in downregulating circulating LEAP2 levels.

Cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) deficiency due to the homozygous PCK1 variant has recently been associated with childhood-onset hypoglycemia with a recognizable pattern of abnormal urine organic acids. In this study 21 children and three adult patients with genetically confirmed PEPCK-C deficiency were diagnosed during the years 2016-2019 and the available biochemical and clinical data were collected. All patients were ethnic Finns. Most patients (22 out of 24) had a previously published homozygous PCK1 variant c.925G>A. Two patients had a novel compound heterozygous PCK1 variant c.925G>A and c.716C>T. The laboratory results showed abnormal urine organic acid profile with increased tricarboxylic acid cycle intermediates and inadequate ketone body production during hypoglycemia. The hypoglycemic episodes manifested predominantly in the morning. Infections, fasting or poor food intake, heavy exercise, alcohol consumption and breastfeeding were identified as triggering factors. Five patients presented with neonatal hypoglycemia. Hypoglycemic seizures occurred in half of the patients (12 out of 24). The first hypoglycemic episode often occurred at the age of 1-2 years, but it sometimes presented at a later age, and could re-occur during school-age or adulthood. This study adds to the laboratory data on PEPCK-C deficiency, confirming the recognizable urine organic acid pattern and identifying deficient ketogenesis as a novel laboratory finding. The phenotype is expanded suggesting that the risk of hypoglycemia may continue into adulthood if predisposing factors are present. This article is protected by copyright. All rights reserved.

Hyperornithinemia with gyrate atrophy of the choroid and retina (HOGA) is a severe recessive inherited disease, causing muscular degeneration and retinochoroidal atrophy that progresses to blindness. HOGA arises from mutations in the ornithine aminotransferase (OAT) gene, and nearly one-third of the known patients worldwide are homozygous for the Finnish founder mutation OAT c.1205 T > C p.(Leu402Pro). We have corrected this loss of-function OAT mutation in patient-derived induced pluripotent stem cells (iPSCs) using CRISPR/Cas9. The correction restored OAT expression in stem cells and normalized the elevated ornithine levels in cell lysates and cell media. These results show an efficient recovery of OAT function in iPSC, encouraging the possibility of autologous cell therapy for the HOGA disease.

Congenital hyperinsulinism (CHI) is a severe inherited neonatal disorder characterized by inappropriate insulin secretion caused by genetic defects of the pancreatic beta cells. Several open questions remain in CHI research, such as the optimal treatment for the most common type of CHI, caused by mutations in the genes encoding ATP-sensitive potassium channels, and the molecular mechanisms of newly identified CHI genes. Answering these questions requires robust preclinical models, particularly since primary patient material is extremely scarce and accurate animal models are not available. In this short review, we explain why pluripotent stem cell derived islets present an attractive solution to these issues and outline the current progress in stem-cell based modeling of CHI. Stem cell derived islets enable the study of molecular mechanisms of CHI and the discovery of novel antihypoglycemic drugs, while also providing a valuable model to study the biology of variable functional states of beta cells.

Neurofilament light (NFL) is one of the proteins forming multimeric neuron-specific intermediate filaments, neurofilaments, which fill the axonal cytoplasm, establish caliber growth, and provide structural support. Dominant missense mutations and recessive nonsense mutations in the neurofilament light gene (NEFL) are among the causes of Charcot–Marie–Tooth (CMT) neuropathy, which affects the peripheral nerves with the longest axons. We previously demonstrated that a neuropathy-causing homozygous nonsense mutation in NEFL led to the absence of NFL in patient-specific neurons. To understand the disease-causing mechanisms, we investigate here the functional effects of NFL loss in human motor neurons differentiated from induced pluripotent stem cells (iPSC). We used genome editing to generate NEFL knockouts and compared them to patient-specific nonsense mutants and isogenic controls. iPSC lacking NFL differentiated efficiently into motor neurons with normal axon growth and regrowth after mechanical axotomy and contained neurofilaments. Electrophysiological analysis revealed that motor neurons without NFL fired spontaneous and evoked action potentials with similar characteristics as controls. However, we found that, in the absence of NFL, human motor neurons 1) had reduced axonal caliber, 2) the amplitude of miniature excitatory postsynaptic currents (mEPSC) was decreased, 3) neurofilament heavy (NFH) levels were reduced and no compensatory increases in other filament subunits were observed, and 4) the movement of mitochondria and to a lesser extent lysosomes was increased. Our findings elaborate the functional roles of NFL in human motor neurons. NFL is not only a structural protein forming neurofilaments and filling the axonal cytoplasm, but our study supports the role of NFL in the regulation of synaptic transmission and organelle trafficking. To rescue the NFL deficiency in the patient-specific nonsense mutant motor neurons, we used three drugs, amlexanox, ataluren (PTC-124), and gentamicin to induce translational read-through or inhibit nonsense-mediated decay. However, the drugs failed to increase the amount of NFL protein to detectable levels and were toxic to iPSC-derived motor neurons. publishedVersion

ObjectiveTo characterize serum biomarkers in mitochondrial CHCHD10-linked spinal muscular atrophy Jokela (SMAJ) type for disease monitoring and for the understanding of pathogenic mechanisms.MethodsWe collected serum samples from a cohort of 49 patients with SMAJ, all carriers of the heterozygous c.197G>T p.G66V variant in CHCHD10. As controls, we used age- and sex-matched serum samples obtained from Helsinki Biobank. Creatine kinase and creatinine were measured by standard methods. Neurofilament light (NfL) and glial fibrillary acidic protein (GFAP) were measured with single molecule array (Simoa), fibroblast growth factor 21 (FGF-21), and growth differentiation factor 15 (GDF-15) with an enzyme-linked immunosorbent assay. For non-targeted plasma metabolite profiling, samples were analyzed with liquid chromatography high-resolution mass spectrometry. Disease severity was evaluated retrospectively by calculating a symptom-based score.ResultsAxon degeneration marker, NfL, was unexpectedly not altered in the serum of patients with SMAJ, whereas astrocytic activation marker, GFAP, was slightly decreased. Creatine kinase was elevated in most patients, particularly men. We identified six metabolites that were significantly altered in serum of patients with SMAJ in comparison to controls: increased creatine and pyruvate, and decreased creatinine, taurine, N-acetyl-carnosine, and succinate. Creatine correlated with disease severity. Altered pyruvate and succinate indicated a metabolic response to mitochondrial dysfunction; however, lactate or mitochondrial myopathy markers FGF-21 or GDF-15 was not changed.ConclusionsBiomarkers of muscle mass and damage are altered in SMAJ serum, indicating a role for skeletal muscle in disease pathogenesis in addition to neurogenic damage. Despite the minimal mitochondrial pathology in skeletal muscle, signs of a metabolic shift can be detected.

OBJECTIVE: ITPR3, encoding inositol 1,4,5-trisphosphate receptor type 3, was previously reported as a potential candidate disease gene for Charcot-Marie-Tooth neuropathy. Here, we present genetic and functional evidence that ITPR3 is a Charcot-Marie-Tooth disease gene. METHODS: Whole-exome sequencing of four affected individuals in an autosomal dominant family and one individual who was the only affected individual in his family was used to identify disease-causing variants. Skin fibroblasts from two individuals of the autosomal dominant family were analyzed functionally by western blotting, quantitative reverse transcription PCR, and Ca2+ imaging. RESULTS: Affected individuals in the autosomal dominant family had onset of symmetrical neuropathy with demyelinating and secondary axonal features at around age 30, showing signs of gradual progression with severe distal leg weakness and hand involvement in the proband at age 64. Exome sequencing identified a heterozygous ITPR3 p.Val615Met variant segregating with the disease. The individual who was the only affected in his family had disease onset at age 4 with demyelinating neuropathy. His condition was progressive, leading to severe muscle atrophy below knees and atrophy of proximal leg and hand muscles by age 16. Trio exome sequencing identified a de novo ITPR3 variant p.Arg2524Cys. Altered Ca2+ -transients in p.Val615Met patient fibroblasts suggested that the variant has a dominant-negative effect on inositol 1,4,5-trisphosphate receptor type 3 function. INTERPRETATION: Together with two previously identified variants, our report adds further evidence that ITPR3 is a disease-causing gene for CMT and indicates altered Ca2+ homeostasis in disease pathogenesis. ispartof: ANNALS OF CLINICAL AND TRANSLATIONAL NEUROLOGY vol:7 issue:10 pages:1962-1972 ispartof: location:United States status: published

Diseases caused by alterations in the DNA can be overcome by providing the cells or tissues with a functional copy of the mutated gene. The most common form of gene therapy implies adding an extra genetic unit into the cell. However, new genome engineering techniques also allow the modification or correction of the existing allele, providing new possibilities, especially for dominant diseases. Gene therapies have been tested for 30 years in thousands of clinical trials, but presently, we have only three authorised gene therapy products for the treatment of inherited diseases in European Union. Here, we describe the gene therapy alternatives already on the market in the European Union and expand the scope to some clinical trials. Additionally, we discuss the ethical and regulatory issues raised by the development of these new kinds of therapies.

Context Major advances have been made in the genetics and classification of congenital hyperinsulinism (CHI). Objective To examine the genetics and clinical characteristics of patients with persistent and transient CHI. Design A cross-sectional study with the register data and targeted sequencing of 104 genes affecting glucose metabolism. Patients Genetic and phenotypic data were collected from 153 patients with persistent (n = 95) and transient (n = 58) CHI diagnosed between 1972 and 2015. Of these, 86 patients with persistent and 58 with transient CHI participated in the analysis of the selected 104 genes affecting glucose metabolism, including 10 CHI-associated genes, and 9 patients with persistent CHI were included because of their previously confirmed genetic diagnosis. Main outcome measures Targeted next-generation sequencing results and genotype–phenotype associations. Results Five novel and 21 previously reported pathogenic or likely pathogenic variants in ABCC8, KCNJ11, GLUD1, GCK, HNF4A, and SLC16A1 genes were found in 68% (n = 65) and 0% of the patients with persistent and transient CHI, respectively. KATP channel mutations explained 82% of the mutation positive cases. Conclusions The genetic variants found in this nationwide CHI cohort are in agreement with previous studies, mutations in the KATP channel genes being the major causes of the disease. Pathogenic CHI-associated variants were not identified in patients who were both diazoxide responsive and able to discontinue medication within the first 4 months. Therefore, our results support the notion that genetic testing should be focused on patients with inadequate response or prolonged need for medication.

FEBS Open Bio 12(7), 1306 - 1324 (2022). doi:10.1002/2211-5463.13422, Charcot–Marie–Tooth disease (CMT) is the most common inherited peripheral polyneuropathy in humans, and its different subtypes are linked to mutations in dozens of different genes. Mutations in ganglioside-induced differentiation-associated protein 1 (GDAP1) cause two types of CMT, demyelinating CMT4A and axonal CMT2K. The GDAP1-linked CMT genotypes are mainly missense point mutations. Despite clinical profiling and in vivo studies on the mutations, the etiology of GDAP1-linked CMT is poorly understood. Here, we describe the biochemical and structural properties of the Finnish founding CMT2K mutation H123R and CMT2K-linked R120W, both of which are autosomal dominant mutations. The disease variant proteins retain close to normal structure and solution behavior, but both present a significant decrease in thermal stability. Using GDAP1 variant crystal structures, we identify a side-chain interaction network between helices ⍺3, ⍺6, and ⍺7, which is affected by CMT mutations, as well as a hinge in the long helix ⍺6, which is linked to structural flexibility. Structural analysis of GDAP1 indicates that CMT may arise from disruption of specific intra- and intermolecular interaction networks, leading to alterations in GDAP1 structure and stability, and, eventually, insufficient motor and sensory neuron function., Published by Wiley, Hoboken, NJ

Surgery with curative intent can be offered to congenital hyperinsulinism (CHI) patients, provided that the lesion is focal. Radiolabeled exendin-4 specifically binds the glucagonlike peptide 1 receptor on pancreatic β-cells. In this study, we compared the performance of 18F-DOPA PET/CT, the current standard imaging method for CHI, and PET/CT with the new tracer 68Ga-NODAGA-exendin-4 in the preoperative detection of focal CHI. Methods: Nineteen CHI patients underwent both 18F-DOPA PET/CT and 68Ga-NODAGA-exendin-4 PET/CT before surgery. The images were evaluated in 3 settings: a standard clinical reading, a masked expert reading, and a joint reading. The target (lesion)-to-nontarget (normal pancreas) ratio was determined using SUVmax Image quality was rated by pediatric surgeons in a questionnaire. Results: Fourteen of 19 patients having focal lesions underwent surgery. On the basis of clinical readings, the sensitivity of 68Ga-NODAGA-exendin-4 PET/CT (100%; 95% CI, 77%-100%) was higher than that of 18F-DOPA PET/CT (71%; 95% CI, 42%-92%). Interobserver agreement between readings was higher for 68Ga-NODAGA-exendin-4 than for 18F-DOPA PET/CT (Fleiss κ = 0.91 vs. 0.56). 68Ga-NODAGA-exendin-4 PET/CT provided significantly (P = 0.021) higher target-to-nontarget ratios (2.02 ± 0.65) than did 18F-DOPA PET/CT (1.40 ± 0.40). On a 5-point scale, pediatric surgeons rated 68Ga-NODAGA-exendin-4 PET/CT as superior to 18F-DOPA PET/CT. Conclusion: For the detection of focal CHI, 68Ga-NODAGA-exendin-4 PET/CT has higher clinical sensitivity and better interobserver correlation than 18F-DOPA PET/CT. Better contrast and image quality make 68Ga-NODAGA-exendin-4 PET/CT superior to 18F-DOPA PET/CT in surgeons' intraoperative quest for lesion localization. ispartof: JOURNAL OF NUCLEAR MEDICINE vol:63 issue:2 pages:310-315 ispartof: location:United States status: published

Type 1 diabetes (T1D) is an autoimmune disease that results in the destruction of insulin producing pancreatic β-cells. One of the genes associated with T1D is TYK2, which encodes a Janus kinase with critical roles in type-Ι interferon (IFN-Ι) mediated intracellular signalling. To study the role of TYK2 in β-cell development and response to IFNα, we generated TYK2 knockout human iPSCs and directed them into the pancreatic endocrine lineage. Here we show that loss of TYK2 compromises the emergence of endocrine precursors by regulating KRAS expression, while mature stem cell-islets (SC-islets) function is not affected. In the SC-islets, the loss or inhibition of TYK2 prevents IFNα-induced antigen processing and presentation, including MHC Class Ι and Class ΙΙ expression, enhancing their survival against CD8+ T-cell cytotoxicity. These results identify an unsuspected role for TYK2 in β-cell development and support TYK2 inhibition in adult β-cells as a potent therapeutic target to halt T1D progression. We gratefully acknowledge Dr. Fatoumata Samassa for help with cytotoxicity assays. We thank Jarkko Ustinov for the insulin and c-peptide ELISA measurements. S. Eurola, H. Grym, and A. Laitinen are thanked for expert technical support. We thank FIMM Single Cell Analytics unit (supported by HiLIFE and Biocentre Finland) for single cell RNA sequencing services. We want to acknowledge the participants and investigators of the FinnGen study. T.O. acknowledges the funding provided by the Academy of Finland (MetaStem Center of Excellence grant 312437), the Novo Nordisk Foundation and the Sigrid Juselius Foundation. R.M. acknowledges the support of the Agence Nationale de la Recherche (ANR-19-CE15-0014-01) and the Fondation pour la Recherche Medicale (EQU20193007831). C.H. was funded by an Année Recherche fellowship of the Paris Saclay University. F.V. was funded by an international PhD fellowship of the IdEx Université de Paris. R.B.P. acknowledges the funding by Hjelt foundation, Crafoord foundation (2020089) and Swedish Research Council (2021-02623). D.L.E. acknowledges the support of grants from the Welbio-FNRS (Fonds National de la Recherche Scientifique; WELBIO-CR-2019C-04), Belgium; the Innovate2CureType1—Dutch Diabetes Research Foundation (DDRF), Holland; the Juvenile Diabetes Foundation (JDRF; 2-SRA-2019-834-S-B); the NIH (HIRN-CBDS) grant U01 DK127786, USA. D.L.E., T.O., and R.M. acknowledge support from the Innovative Medicines Initiative 2 Joint Undertaking under grant agreements No 115797 (INNODIA) and 945268 (INNODIA HARVEST), supported by the European Union’s Horizon 2020 research and innovation programme. These Joint Undertakings receive support from the Union’s Horizon 2020 research and innovation programme and “EFPIA”, “JDRF” and “The Leona M. and Harry B. Helmsley Charitable Trust”.

Nuclear receptor subfamily 5 group A member 1 (NR5A1) encodes steroidogenic factor 1 (SF1), a key regulatory factor that determines gonadal development and coordinates endocrine functions. Here, we have established a stem cell-based model of human gonadal development and applied it to evaluate the effects of NR5A1 during the transition from bipotential gonad to testicular cells. We combined directed differentiation of human induced pluripotent stem cells (46,XY) with activation of endogenous NR5A1 expression by conditionally-inducible CRISPR activation. The resulting male gonadal-like cells expressed several Sertoli cell transcripts, secreted anti-Müllerian hormone and responded to follicle-stimulating hormone by producing sex steroid intermediates. These characteristics were not induced without NR5A1 activation. A total of 2691 differentially expressed genetic elements, including both coding and non-coding RNAs, were detected immediately following activation of NR5A1 expression. Of those, we identified novel gonad-related putative NR5A1 targets, such as SCARA5, which we validated also by immunocytochemistry. In addition, NR5A1 activation was associated with dynamic expression of multiple gonad- and infertility-related differentially expressed genes. In conclusion, by combining targeted differentiation and endogenous activation of NR5A1 we have for the first time, been able to examine in detail the effects of NR5A1 in early human gonadal cells. The model and results obtained provide a useful resource for future investigations exploring the causative reasons for gonadal dysgenesis and infertility in humans. publishedVersion

An increasing aging population poses a significant challenge to societies worldwide. A better understanding of the molecular, cellular, organ, tissue, physiological, psychological, and even sociological changes that occur with aging is needed in order to treat age-associated diseases. The field of aging research is rapidly expanding with multiple advances transpiring in many previously disconnected areas. Several major pharmaceutical, biotechnology, and consumer companies made aging research a priority and are building internal expertise, integrating aging research into traditional business models and exploring new go-to-market strategies. Many of these efforts are spearheaded by the latest advances in artificial intelligence, namely deep learning, including generative and reinforcement learning. To facilitate these trends, the Center for Healthy Aging at the University of Copenhagen and Insilico Medicine are building a community of Key Opinion Leaders (KOLs) in these areas and launched the annual conference series titled "Aging Research and Drug Discovery (ARDD)" held in the capital of the pharmaceutical industry, Basel, Switzerland (www.agingpharma.org). This ARDD collection contains summaries from the 6th annual meeting that explored aging mechanisms and new interventions in age-associated diseases. The 7th annual ARDD exhibition will transpire 2nd-4th of September, 2020, in Basel.

The article Alternative NADH dehydrogenase extends lifespan and increases resistance to xenobiotics in Drosophila, written by Dmytro V. Gospodaryov. Olha M. Strilbytska. Uliana V. Semaniuk. Natalia V. Perkhulyn. Bohdana M. Rovenko. Ihor S. Yurkevych. Ana G. Barata. Tobias P. Dick. Oleh V. Lushchak and Howard T. Jacobs, was originally published electronically on the publisher's internet portal on 20 November 2019 without open access. With the author(s)' decision to opt for Open Choice the copyright of the article changed on 27 January 2020 to © The Author(s) 2020 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The original article has been corrected.

Accumulating evidence indicates that gut microbiota may regulate sex-hormone levels in the host, with effects on reproductive health. Very little is known about the development of intestinal microbiota during puberty in humans. To assess the connection between pubertal timing and fecal microbiota, and to assess how fecal microbiota develop during puberty in comparison with adult microbiota, we utilized a Finnish allergy-prevention-trial cohort (Flora). Data collected at 13-year follow-up were compared with adult data from a different Finnish cohort. Among the 13-year-old participants we collected questionnaire information, growth data from school-health-system records and fecal samples from 148 participants. Reference adult fecal samples were received from the Health and Early Life Microbiota (HELMi) cohort (n = 840). Fecal microbiota were analyzed using 16S rRNA gene amplicon sequencing; the data were correlated with pubertal timing and compared with data on adult microbiota. Probiotic intervention in the allergy-prevention-trial cohort was considered as a confounding factor only. The main outcome was composition of the microbiota in relation to pubertal timing (time to/from peak growth velocity) in both sexes separately, and similarity to adult microbiota. In girls, fecal microbiota became more adult-like with pubertal progression (p = 0.009). No such development was observed in boys (p = 0.9). Both sexes showed a trend towards increasing relative abundance of estrogen-metabolizing Clostridia and decreasing Bacteroidia with pubertal development, but this was statistically significant in girls only (p = 0.03). In girls, pubertal timing was associated positively with exposure to cephalosporins prior to the age of 10. Our data support the hypothesis that gut microbiota, particularly members of Ruminococcaceae, may affect pubertal timing, possibly via regulating host sex-hormone levels.Trial registration The registration number for the allergy-prevention-trial cohort: ClinicalTrials.gov, NCT00298337, registered 1 March 2006—Retrospectively registered, https://clinicaltrials.gov/show/NCT00298337. The adult-comparison cohort (HELMi) is NCT03996304.

17 p.-8 fig., Smooth muscle is an essential component of the intestine, both to maintain its structure and produce peristaltic and segmentation movements. However, very little is known about other putative roles that smooth muscle cells may have. Here, we show that smooth muscle cells may be the dominant suppliers of BMP antagonists, which are niche factors essential for intestinal stem cell maintenance. Furthermore, muscle-derived factors render epithelium reparative and fetal-like, which includes heightened YAP activity. Mechanistically, we find that the membrane-bound matrix metalloproteinase MMP17, which is exclusively expressed by smooth muscle cells, is required for intestinal epithelial repair after inflammation- or irradiation-induced injury. Furthermore, we propose that MMP17 affects intestinal epithelial reprogramming after damage indirectly by cleaving diffusible factor(s) such as the matricellular protein PERIOSTIN. Together, we identify an important signaling axis that establishes a role for smooth muscle cells as modulators of intestinal epithelial regeneration and the intestinal stem cell niche., The WT KO crypt-muscle RNA-seq was done by the Genomics Core Facility at NTNU, which receives funding from the Faculty of Medicine and Health Sciences and Central Norway Regional Health Authority. This research was part of the Netherlands X-omics Initiative and partially funded by NWO (project 184.034.019). This work was further financially supported by the Norwegian Research Council (Centre of Excellence grant 223255/F50, and ‘Young Research Talent’ 274760 to M.J.O.) and the Norwegian Cancer Society (182767 to M.J.O.). MMA is the recipient of a Marie Skłodowska-Curie IF (DLV-794391).