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Insulin is made from proinsulin, but the extent to which fasting/feeding controls the homeostatically regulated proinsulin pool in pancreatic ß-cells remains largely unknown. Here, we first examined ß-cell lines (INS1E and Min6, which proliferate slowly and are routinely fed fresh medium every 2-3 days) and found that the proinsulin pool size responds to each feeding within 1 to 2 h, affected both by the quantity of fresh nutrients and the frequency with which they are provided. We observed no effect of nutrient feeding on the overall rate of proinsulin turnover as quantified from cycloheximide-chase experiments. We show that nutrient feeding is primarily linked to rapid dephosphorylation of translation initiation factor eIF2α, presaging increased proinsulin levels (and thereafter, insulin levels), followed by its rephosphorylation during the ensuing hours that correspond to a fall in proinsulin levels. The decline of proinsulin levels is blunted by the integrated stress response inhibitor, ISRIB, or by inhibition of eIF2α rephosphorylation with a general control nonderepressible 2 (not PERK) kinase inhibitor. In addition, we demonstrate that amino acids contribute importantly to the proinsulin pool; mass spectrometry shows that ß-cells avidly consume extracellular glutamine, serine, and cysteine. Finally, we show that in both rodent and human pancreatic islets, fresh nutrient availability dynamically increases preproinsulin, which can be quantified without pulse-labeling. Thus, the proinsulin available for insulin biosynthesis is rhythmically controlled by fasting/feeding cycles.
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Células Secretoras de Insulina , Nutrientes , Proinsulina , Humanos , Insulina/biossíntese , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Nutrientes/farmacologia , Proinsulina/biossíntese , Proinsulina/metabolismo , Estresse Fisiológico , Transdução de Sinais , Linhagem Celular , Regulação para CimaRESUMO
BACKGROUND: Perinatal asphyxia often leads to hypoxic-ischemic encephalopathy (HIE) with a high risk of neurodevelopmental consequences. While moderate and severe HIE link to high morbidity, less is known about brain effects of perinatal asphyxia with no or only mild HIE. Here, we test the hypothesis that cortical activity networks in the newborn infants show a dose-response to asphyxia. METHODS: We performed EEG recordings for infants with perinatal asphyxia/HIE of varying severity (n = 52) and controls (n = 53) and examined well-established computational metrics of cortical network activity. RESULTS: We found graded alterations in cortical activity networks according to severity of asphyxia/HIE. Furthermore, our findings correlated with early clinical recovery measured by the time to attain full oral feeding. CONCLUSION: We show that both local and large-scale correlated cortical activity are affected by increasing severity of HIE after perinatal asphyxia, suggesting that HIE and perinatal asphyxia are better represented as a continuum rather than the currently used discreet categories. These findings imply that automated computational measures of cortical function may be useful in characterizing the dose effects of adversity in the neonatal brain; such metrics hold promise for benchmarking clinical trials via patient stratification or as early outcome measures. IMPACT: Perinatal asphyxia causes every fourth neonatal death worldwide and provides a diagnostic and prognostic challenge for the clinician. We report that infants with perinatal asphyxia show specific graded responses in cortical networks according to severity of asphyxia and ensuing hypoxic-ischaemic encephalopathy. Early EEG recording and automated computational measures of brain function have potential to help in clinical evaluation of infants with perinatal asphyxia.
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Asfixia Neonatal , Córtex Cerebral , Eletroencefalografia , Hipóxia-Isquemia Encefálica , Humanos , Recém-Nascido , Asfixia Neonatal/fisiopatologia , Asfixia Neonatal/complicações , Hipóxia-Isquemia Encefálica/fisiopatologia , Feminino , Masculino , Córtex Cerebral/fisiopatologia , Estudos de Casos e Controles , Rede Nervosa/fisiopatologia , Índice de Gravidade de DoençaRESUMO
OBJECTIVE: To assess whether computational electroencephalogram (EEG) measures during the first day of life correlate to clinical outcomes in infants with perinatal asphyxia with or without hypoxic-ischemic encephalopathy (HIE). METHODS: We analyzed four-channel EEG monitoring data from 91 newborn infants after perinatal asphyxia. Altogether 42 automatically computed amplitude- and synchrony-related EEG features were extracted as 2-hourly average at very early (6 h) and early (24 h) postnatal age; they were correlated to the severity of HIE in all infants, and to four clinical outcomes available in a subcohort of 40 newborns: time to full oral feeding (nasogastric tube NGT), neonatal brain MRI, Hammersmith Infant Neurological Examination (HINE) at three months, and Griffiths Scales at two years. RESULTS: At 6 h, altogether 14 (33%) EEG features correlated significantly to the HIE grade ([r]= 0.39-0.61, p < 0.05), and one feature correlated to NGT ([r]= 0.50). At 24 h, altogether 13 (31%) EEG features correlated significantly to the HIE grade ([r]= 0.39-0.56), six features correlated to NGT ([r]= 0.36-0.49) and HINE ([r]= 0.39-0.61), while no features correlated to MRI or Griffiths Scales. CONCLUSIONS: Our results show that the automatically computed measures of early cortical activity may provide outcome biomarkers for clinical and research purposes. IMPACT: The early EEG background and its recovery after perinatal asphyxia reflect initial severity of encephalopathy and its clinical recovery, respectively. Computational EEG features from the early hours of life show robust correlations to HIE grades and to early clinical outcomes. Computational EEG features may have potential to be used as cortical activity biomarkers in early hours after perinatal asphyxia.
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Controlled assessment of functional cortical networks is an unmet need in the clinical research of noncooperative subjects, such as infants. We developed an automated, pneumatic stimulation method to actuate naturalistic movements of an infant's hand, as well as an analysis pipeline for assessing the elicited electroencephalography (EEG) responses and related cortical networks. Twenty newborn infants with perinatal asphyxia were recruited, including 7 with mild-to-moderate hypoxic-ischemic encephalopathy (HIE). Statistically significant corticokinematic coherence (CKC) was observed between repetitive hand movements and EEG in all infants, peaking near the contralateral sensorimotor cortex. CKC was robust to common sources of recording artifacts and to changes in vigilance state. A wide recruitment of cortical networks was observed with directed phase transfer entropy, also including areas ipsilateral to the stimulation. The extent of such recruited cortical networks was quantified using a novel metric, Spreading Index, which showed a decrease in 4 (57%) of the infants with HIE. CKC measurement is noninvasive and easy to perform, even in noncooperative subjects. The stimulation and analysis pipeline can be fully automated, including the statistical evaluation of the cortical responses. Therefore, the CKC paradigm holds great promise as a scientific and clinical tool for controlled assessment of functional cortical networks.
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Magnetoencefalografia , Movimento , Recém-Nascido , Humanos , Lactente , Magnetoencefalografia/métodos , Fenômenos Biomecânicos/fisiologia , Movimento/fisiologia , Eletroencefalografia , MãosRESUMO
BACKGROUND: Major brain injuries in structural brain magnetic resonance imaging (MRI) at term affect concurrent diffusion tensor imaging (DTI) parameters in very preterm infants. White matter is known to gradually maturate along with increasing gestational age, which is characterized by increasing fractional anisotropy (FA) and decreasing mean diffusivity (MD). PURPOSE: To study the difference between DTI parameters at term and 13 years in adolescents born very preterm with and without major pathologies in structural brain MRI at term. MATERIAL AND METHODS: Adolescents born very preterm (gestational age <32 weeks and/or birth weight ≤1500 g) in 2004-2006 at Turku University Hospital, Finland were included. We evaluated FA and MD at term and 13 years in 18 regions of interest using the JHU-neonate-SS atlas to compare the differences in these parameters between adolescents with and without major injuries identified on MRI at term. RESULTS: A total of 24 adolescents underwent brain MRI including DTI both at term and 13 years. Adolescents with major brain injury pathologies (n = 6) in structural MRI at term had decreased FA in the left corpus callosum and right cingulate gyrus part, and increased MD in the left corpus callosum, right anterior limb of internal capsule, and right posterior limb of the internal capsule at 13 years, in comparison with adolescents without major brain injuries (n = 18) in structural MRI at term. CONCLUSION: Our findings suggest that major brain injuries identified on structural MRI at term affect brain maturation, with adverse effects in FA and MD still during adolescence.
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Etiologies and the whole picture in childhood mental, behavioral, and neurodevelopmental disorders related to gestational age are unclear. This study included all Finnish children (N = 341,632) born between January 1, 2001, and December 31, 2006, whose data including their mothers (N = 241,284) were collected from national registers. Children with unclear gestational age (GA) (N = 1245), severe congenital malformations (N = 11,746), and moderate/severe/undefined cognitive impairment (N = 1140), and those who died during the perinatal period (N = 599) were excluded. The main outcome was the prevalence of mental and behavioral disorders (International Classification of Disorders) at 0 - 12 years of age in association with GA, adjusted for gender and prenatal variables. Out of all included (N = 326,902) children 16.6% (N = 54,270) were diagnosed to have any mental health disorder at 0 - 12 years. Adjusted Odd Ratio (OR) were for any disorder in preterm (< 37 weeks) 1.37 [1.28 - 1.46] and 4.03 [3.08 - 5.26] in extreme preterm (≤ 28 weeks) versus term born children, p < 0.05. The lower the GA at birth, the higher the risk for multiple disorders and earlier onset of disorder, p < 0.05. Adjusted ORs were for male/female 1.94 [1.90 - 1.99], maternal mental health disorder (yes/not) 1.99 [1.92 - 2.07], and smoking during pregnancy (yes/not) 1.58 [1.54 - 1.62], and these risks were more common in preterm versus term born children (p < 0.05). Extreme early birth was a strong risk factor per se for any or multiple and early shown mental health disorders. Other risk factors for mental health accumulated to preterm children.
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Disfunção Cognitiva , Transtornos do Neurodesenvolvimento , Recém-Nascido , Gravidez , Criança , Humanos , Masculino , Feminino , Finlândia/epidemiologia , Transtornos do Neurodesenvolvimento/epidemiologia , Fatores de Risco , MãesRESUMO
Preproinsulin entry into the endoplasmic reticulum yields proinsulin, and its subsequent delivery to the distal secretory pathway leads to processing, storage, and secretion of mature insulin. Multiple groups have reported that treatment of pancreatic beta cell lines, rodent pancreatic islets, or human islets with proteasome inhibitors leads to diminished proinsulin and insulin protein levels, diminished glucose-stimulated insulin secretion, and changes in beta-cell gene expression that ultimately lead to beta-cell death. However, these studies have mostly examined treatment times far beyond that needed to achieve acute proteasomal inhibition. Here, we report that although proteasomal inhibition immediately downregulates new proinsulin biosynthesis, it nevertheless acutely increases beta-cell proinsulin levels in pancreatic beta cell lines, rodent pancreatic islets, and human islets, indicating rescue of a pool of recently synthesized WT INS gene product that would otherwise be routed to proteasomal disposal. Our pharmacological evidence suggests that this disposal most likely reflects ongoing endoplasmic reticulum-associated protein degradation. However, we found that within 60 min after proteasomal inhibition, intracellular proinsulin levels begin to fall in conjunction with increased phosphorylation of eukaryotic initiation factor 2 alpha, which can be inhibited by blocking the general control nonderepressible 2 kinase. Together, these data demonstrate that a meaningful subfraction of newly synthesized INS gene product undergoes rapid proteasomal disposal. We propose that free amino acids derived from proteasomal proteolysis may potentially participate in suppressing general control nonderepressible 2 kinase activity to maintain ongoing proinsulin biosynthesis.
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Degradação Associada com o Retículo Endoplasmático , Células Secretoras de Insulina , Ilhotas Pancreáticas , Proinsulina , Complexo de Endopeptidases do Proteassoma , Proteólise , Humanos , Glucose/metabolismo , Células Secretoras de Insulina/enzimologia , Ilhotas Pancreáticas/metabolismo , Proinsulina/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismoRESUMO
BACKGROUND: Maternal metabolic disturbances and diet may influence long-term infantile neurodevelopment. We investigated whether maternal gestational diabetes mellitus (GDM), obesity, and diet could affect the neurodevelopment of 2-year-old children. METHODS: Neurodevelopment of children (n = 243) born to mothers with overweight or obesity was assessed with the Bayley Scales of Infant and Toddler Development-Third Edition, and the Hammersmith Infant Neurological Examination. Maternal adiposity was determined by air displacement plethysmography, and GDM with an oral glucose tolerance test. Dietary assessment included diet quality and fish consumption questionnaires, and three-day food diaries, from which dietary inflammatory index (DII®) scores were computed. RESULTS: GDM was associated with weaker expressive language skills (adj.ß = -1.12, 95% CI = -2.10;-0.15), and higher maternal adiposity with weaker cognitive, language, and motor skills in children (adj.p < 0.05). Maternal good dietary quality (adj.ß = 0.87, 95% CI = 0.004;1.73) and higher fish consumption (adj.p = 0.02) were related to better expressive language skills. DII scores were not associated with children's neurodevelopment. CONCLUSIONS: Findings suggest that GDM and higher maternal adiposity may lead to weaker neurodevelopmental skills, although still within the mean normative range in this population of children. Good dietary quality and higher fish consumption during pregnancy could benefit a child's language development. IMPACT: Gestational diabetes mellitus and maternal higher adiposity may have unfavorable effects on a 2-year-old child's neurodevelopment. An overall good quality of diet and higher fish consumption during pregnancy may result in more favorable cognitive and language skills when the child is 2-year-old. Our findings reveal that women with overweight or obesity, a risk group for pregnancy complications, could benefit from dietary counseling to support their children's neurodevelopment.
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Diabetes Gestacional , Obesidade Materna , Animais , Gravidez , Feminino , Humanos , Sobrepeso/complicações , Obesidade Materna/complicações , Obesidade/complicações , DietaRESUMO
BACKGROUND: Preterm infants have a risk of health and developmental problems emerging after discharge. This indicates the need for a comprehensive follow-up to enable early identification of these problems. In this paper, we introduce a follow-up tool "ePIPARI - web-based follow-up for preterm infants". Our future aim is to investigate whether ePIPARI is a feasible tool in the follow-up of preterm infants and whether it can identify children and parents in need of clinical interventions. METHODS: ePIPARI includes eight assessment points (at term age and at 1, 2, 4, 8, 12, 18, and 24 months of corrected age) when the child´s health and growth, eating and feeding, neurodevelopment, and parental well-being are evaluated. ePIPARI consists of several widely used, standardized questionnaires, in addition to questions typically presented to parents in clinical follow-up visits. It also provides video guidance and written information about age-appropriate neurodevelopment for the parents. Parents of children born before 34 weeks of gestation during years 2019-2022 are being invited to participate in the ePIPARI study, in which web-based follow-up with ePIPARI is compared to clinical follow-up. In addition, the parents of children born before 32 weeks of gestation, who reached the corrected age of two years during 2019-2021 were invited to participate for the assessment point of 24 months of ePIPARI. The parents are asked to fill in the online questionnaires two weeks prior to each clinical follow-up visit. DISCUSSION: The web-based tool, ePIPARI, was developed to acquire a sensitive and specific tool to detect infants and parents in need of further support and clinical interventions. This tool could allow individualized adjustments of the frequency and content of the clinical visits. TRIAL REGISTRATION: ClinicalTrials.cov, NCT05238168 . Registered 11 April 2022 - Retrospectively registered.
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Recém-Nascido Prematuro , Pais , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Estudos de Viabilidade , Seguimentos , InternetRESUMO
Proteins have evolved to be foldable, and yet determinants of foldability may be inapparent once the native state is reached. Insight has emerged from studies of diseases of protein misfolding, exemplified by monogenic diabetes mellitus due to mutations in proinsulin leading to endoplasmic reticulum stress and ß-cell death. Cellular foldability of human proinsulin requires an invariant Phe within a conserved crevice at the receptor-binding surface (position B24). Any substitution, even related aromatic residue TyrB24, impairs insulin biosynthesis and secretion. As a seeming paradox, a monomeric TyrB24 insulin analog exhibits a native-like structure in solution with only a modest decrement in stability. Packing of TyrB24 is similar to that of PheB24, adjoining core cystine B19-A20 to seal the core; the analog also exhibits native self-assembly. Although affinity for the insulin receptor is decreased â¼20-fold, biological activities in cells and rats were within the range of natural variation. Together, our findings suggest that the invariance of PheB24 among vertebrate insulins and insulin-like growth factors reflects an essential role in enabling efficient protein folding, trafficking, and secretion, a function that is inapparent in native structures. In particular, we envision that the para-hydroxyl group of TyrB24 hinders pairing of cystine B19-A20 in an obligatory on-pathway folding intermediate. The absence of genetic variation at B24 and other conserved sites near this disulfide bridge-excluded due to ß-cell dysfunction-suggests that insulin has evolved to the edge of foldability. Nonrobustness of a protein's fitness landscape underlies both a rare monogenic syndrome and "diabesity" as a pandemic disease of civilization.
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Insulina/metabolismo , Substituição de Aminoácidos/fisiologia , Animais , Linhagem Celular , Linhagem Celular Tumoral , Diabetes Mellitus/metabolismo , Dissulfetos/metabolismo , Redes Reguladoras de Genes/fisiologia , Células HEK293 , Humanos , Células Secretoras de Insulina/metabolismo , Células MCF-7 , Proinsulina/metabolismo , Ligação Proteica/fisiologia , Dobramento de Proteína , Ratos , Receptor de Insulina/metabolismo , Relação Estrutura-AtividadeRESUMO
BACKGROUND: New biomarkers that predict later neurodevelopmental morbidity are needed. This study evaluated the associations between umbilical cord serum erythropoietin (us-EPO) and neurodevelopmental morbidity by the age of 2-6.5 years in a Finnish cohort. METHODS: This study included 878 non-anomalous children born alive in 2012 to 2016 in Helsinki University Hospitals and whose us-EPO concentration was determined at birth. Data of these children were linked to data from the Finnish Medical Birth Register and the Finnish Hospital Discharge Register. Neurodevelopmental morbidity included cerebral palsy, epilepsy, intellectual disability, autism spectrum disorder, sensorineural defects, and minor neurodevelopmental disorders. RESULTS: In the cohort including both term and preterm children, us-EPO levels correlated with gestational age (r = 0.526) and were lower in premature children. High us-EPO levels (>100 IU/l) were associated with an increased risk of severe neurodevelopmental morbidity (OR: 4.87; 95% CI: 1.05-22.58) when adjusted for the gestational age. The distribution of us-EPO levels did not differ in children with or without the later neurodevelopmental diagnosis. CONCLUSIONS: Although high us-EPO concentration at birth was associated with an increased risk of neurodevelopmental morbidity in early childhood, the role of us-EPO determination in clinical use appears to be minor. IMPACT: We determined whether endogenous umbilical cord serum erythropoietin would be a new useful biomarker to predict the risk of neurodevelopmental morbidity. This study evaluated the role of endogenous erythropoietin at birth in neurodevelopmental morbidity with a study population of good size and specific diagnoses based on data from high-quality registers. Although high umbilical cord serum erythropoietin concentration at birth was associated with an increased risk of neurodevelopmental morbidity in early childhood, the clinical value of erythropoietin determination appears to be minor.
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Anemia Neonatal , Transtorno do Espectro Autista , Eritropoetina , Transtornos do Neurodesenvolvimento , Anemia Neonatal/induzido quimicamente , Transtorno do Espectro Autista/induzido quimicamente , Criança , Pré-Escolar , Transfusão de Eritrócitos , Feminino , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Recém-Nascido Prematuro , Morbidade , Transtornos do Neurodesenvolvimento/epidemiologiaRESUMO
AIM: We explored the ability of the Hammersmith Infant Neurological Examination (HINE) to identify cognitive performance delay at 2 years in a large cohort of infants born at term. METHOD: We conducted a retrospective study of infants born at term at risk of neurodevelopmental impairments assessed using the HINE between 3 and 12 months post-term age and compared them with a cohort of typically developing infants born at term. All infants performed a neurodevelopmental assessment at 2 years of age using the Mental Development Index (MDI) of the Bayley Scales of Infant Development, Second Edition; the presence of cerebral palsy (CP) was also reported. The infants were classified as being cognitively normal/mildly delayed or significantly delayed (MDI < 70). The predictive validity of HINE scores for significantly delayed cognitive performance, in infants with and without CP, was calculated using specific cut-off scores according to age at assessment. RESULTS: A total of 446 at-risk and 235 typically developing infants (345 males, 336 females; mean [SD] gestational age 38.7 weeks [1.4], range 37-43 weeks) were included. Of the at-risk infants, 408 did not have CP at 2 years; 243 had a normal/mild delayed MDI and 165 had an MDI less than 70. Of the at-risk infants, 38 developed CP. HINE scores showed a good sensitivity and specificity, mainly after 3 months, for identifying significantly delayed cognitive performance in infants without CP. In those with CP, the score was associated with their cognitive performance. The comparison group had the highest HINE scores. INTERPRETATION: The HINE provides evidence about the risk of delayed cognitive performance at age 2 years in infants born at term with and without CP.
EXAMEN NEUROLÓGICO INFANTIL DE HAMMERSMITH EN BEBÉS NACIDOS A TÉRMINO: SU USO PARA PREDECIR OTRAS CONDICIONES ADEMÁS DE LA PARÁLISIS CEREBRAL: OBJETIVO: Valoramos la capacidad del examen neurológico infantil de Hammersmith (HINE) para identificar el retraso en el rendimiento cognitivo a los 2 años en una cohorte grande de bebés nacidos a término. MÉTODO: Realizamos un estudio retrospectivo de bebés nacidos a término con riesgo de trastornos del desarrollo neurológico evaluados mediante el HINE entre los 3 y los 12 meses de edad postérmino y los comparamos con una cohorte de bebés nacidos a término con un desarrollo típico. Todos los bebés realizaron una evaluación del desarrollo neurológico a los 2 años de edad utilizando el Índice de Desarrollo Mental (MDI) de las Escalas de Desarrollo Infantil de Bayley, Segunda Edición; también se informó la presencia de parálisis cerebral (PC). Los bebés se clasificaron como cognitivamente normales/levemente con retreaso o significativamente con retraso (MDI < 70). La validez predictiva de las puntuaciones HINE para el rendimiento cognitivo con retraso significativo, en bebés con y sin parálisis cerebral, se calculó utilizando puntuaciones de corte específicas según la edad en la evaluación. RESULTADOS: Se incluyeron un total de 446 lactantes en riesgo y 235 con desarrollo normal (345 varones, 336 mujeres; edad gestacional media [DE] 38,7 semanas [1,4], rango de 37 a 43 semanas). De los lactantes en riesgo, 408 no tenían parálisis cerebral a los 2 años; 243 tenían un MDI con retraso normal/leve y 165 tenían un MDI inferior a 70. De los bebés en riesgo, 38 desarrollaron PC. Las puntuaciones HINE mostraron una buena sensibilidad y especificidad, principalmente después de 3 meses, para identificar un rendimiento cognitivo severo en lactantes sin PC. En aquellos con PC, la puntuación se asoció con su rendimiento cognitivo. El grupo de comparación tuvo las puntuaciones HINE más altas. INTERPRETACIÓN: El HINE proporciona evidencia sobre el riesgo de retraso en el rendimiento cognitivo a los 2 años de edad en bebés nacidos a término con y sin parálisis cerebral.
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Paralisia Cerebral , Paralisia Cerebral/diagnóstico , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Idade Gestacional , Humanos , Lactente , Masculino , Exame Neurológico , Estudos RetrospectivosRESUMO
A precondition for efficient proinsulin export from the endoplasmic reticulum (ER) is that proinsulin meets ER quality control folding requirements, including formation of the Cys(B19)-Cys(A20) "interchain" disulfide bond, facilitating formation of the Cys(B7)-Cys(A7) bridge. The third proinsulin disulfide, Cys(A6)-Cys(A11), is not required for anterograde trafficking, i.e., a "lose-A6/A11" mutant [Cys(A6), Cys(A11) both converted to Ser] is well secreted. Nevertheless, an unpaired Cys(A11) can participate in disulfide mispairings, causing ER retention of proinsulin. Among the many missense mutations causing the syndrome of Mutant INS gene-induced Diabetes of Youth (MIDY), all seem to exhibit perturbed proinsulin disulfide bond formation. Here, we have examined a series of seven MIDY mutants [including G(B8)V, Y(B26)C, L(A16)P, H(B5)D, V(B18)A, R(Cpep + 2)C, E(A4)K], six of which are essentially completely blocked in export from the ER in pancreatic ß-cells. Three of these mutants, however, must disrupt the Cys(A6)-Cys(A11) pairing to expose a critical unpaired cysteine thiol perturbation of proinsulin folding and ER export, because when introduced into the proinsulin lose-A6/A11 background, these mutants exhibit native-like disulfide bonding and improved trafficking. This maneuver also ameliorates dominant-negative blockade of export of co-expressed wild-type proinsulin. A growing molecular understanding of proinsulin misfolding may permit allele-specific pharmacological targeting for some MIDY mutants.
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Diabetes Mellitus Tipo 2/metabolismo , Proinsulina/metabolismo , Adolescente , Células Cultivadas , Cisteína/genética , Cisteína/metabolismo , Diabetes Mellitus Tipo 2/genética , Dissulfetos/metabolismo , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Humanos , Insulina/genética , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Mutação de Sentido Incorreto/genética , Proinsulina/genética , Dobramento de ProteínaRESUMO
AIM: To characterise the spectrum of findings in sequential neurological examinations, general movements (GM) assessment and magnetic resonance imaging (MRI) of infants with perinatal asphyxia. METHODS: The prospective cohort study of term infants with perinatal asphyxia treated at Helsinki University Hospital's neonatal units in 2016-2020 used Hammersmith Neonatal Neurological Examination (HNNE) and brain MRI at 2 weeks and Hammersmith Infant Neurological Examination (HINE) and GM assessment at 3 months of age. RESULTS: Analysis included 50 infants: 33 displaying perinatal asphyxia without hypoxic-ischaemic encephalopathy (HIE), seven with HIE1 and 10 with HIE2. Of the infants with atypical HNNE findings, 24/25 perinatal asphyxia without HIE cases, 5/6 HIE1 cases and all 10 HIE2 cases showed atypical findings in the HINE. The HINE identified atypical spontaneous movements significantly more often in infants with white matter T2 hyperintensity. CONCLUSION: In this cohort, most infants with perinatal asphyxia, with or without HIE, presented atypical neurological findings in sequential examinations. The profile of neurological findings for children with perinatal asphyxia without HIE resembled that of children with HIE. White matter T2 hyperintensity was associated with atypical spontaneous movements in the HINE and was a frequent MRI finding also in perinatal asphyxia without HIE.
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Asfixia Neonatal , Hipóxia-Isquemia Encefálica , Asfixia , Asfixia Neonatal/complicações , Criança , Estudos de Coortes , Feminino , Humanos , Hipóxia-Isquemia Encefálica/diagnóstico por imagem , Hipóxia-Isquemia Encefálica/epidemiologia , Lactente , Recém-Nascido , Gravidez , Estudos ProspectivosRESUMO
Globular protein sequences encode not only functional structures (the native state) but also protein foldability, i.e. a conformational search that is both efficient and robustly minimizes misfolding. Studies of mutations associated with toxic misfolding have yielded insights into molecular determinants of protein foldability. Of particular interest are residues that are conserved yet dispensable in the native state. Here, we exploited the mutant proinsulin syndrome (a major cause of permanent neonatal-onset diabetes mellitus) to investigate whether toxic misfolding poses an evolutionary constraint. Our experiments focused on an invariant aromatic motif (PheB24-PheB25-TyrB26) with complementary roles in native self-assembly and receptor binding. A novel class of mutations provided evidence that insulin can bind to the insulin receptor (IR) in two different modes, distinguished by a "register shift" in this motif, as visualized by molecular dynamics (MD) simulations. Register-shift variants are active but defective in cellular foldability and exquisitely susceptible to fibrillation in vitro Indeed, expression of the corresponding proinsulin variant induced endoplasmic reticulum stress, a general feature of the mutant proinsulin syndrome. Although not present among vertebrate insulin and insulin-like sequences, a prototypical variant ([GlyB24]insulin) was as potent as WT insulin in a rat model of diabetes. Although in MD simulations the shifted register of receptor engagement is compatible with the structure and allosteric reorganization of the IR-signaling complex, our results suggest that this binding mode is associated with toxic misfolding and so is disallowed in evolution. The implicit threat of proteotoxicity limits sequence variation among vertebrate insulins and insulin-like growth factors.
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Evolução Molecular , Insulina/análogos & derivados , Motivos de Aminoácidos , Animais , Sítios de Ligação , Glicemia/análise , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Células HEK293 , Humanos , Insulina/metabolismo , Insulina/uso terapêutico , Simulação de Dinâmica Molecular , Ligação Proteica , Dobramento de Proteína , Estabilidade Proteica , Ratos , Receptor de Insulina/metabolismo , Relação Estrutura-Atividade , TermodinâmicaRESUMO
OBJECTIVES: Impairments in visual perception are among the most common developmental difficulties related to being born prematurely, and they are often accompanied by problems in other developmental domains. Neural activation in participants born prematurely and full-term during tasks that assess several areas of visual perception has not been studied. To better understand the neural substrates of the visual perceptual impairments, we compared behavioral performance and brain activations during visual perception tasks in adolescents born very preterm (birth weight ≤1500 g or gestational age <32 weeks) and full-term. METHODS: Tasks assessing visual closure, discrimination of a deviating figure, and discrimination of figure and ground from the Motor-Free Visual Perception Test, Third Edition were performed by participants born very preterm (n = 37) and full-term (n = 34) at 12 years of age during functional magnetic resonance imaging. RESULTS: Behavioral performance in the visual perception tasks did not differ between the groups. However, during the visual closure task, brain activation was significantly stronger in the group born very preterm in a number of areas including the frontal, anterior cingulate, temporal, and posterior medial parietal/cingulate cortices, as well as in parts of the cerebellum, thalamus, and caudate nucleus. CONCLUSIONS: Differing activations during the visual closure task potentially reflect a compensatory neural process related to premature birth or lesser neural efficiency or may be a result of the use of compensatory behavioral strategies in the study group born very preterm.
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Nascimento Prematuro , Percepção Visual , Adolescente , Encéfalo/diagnóstico por imagem , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética , GravidezRESUMO
OBJECTIVES: The aim of the study was to evaluate the neurocognitive and motor development of biliary atresia (BA) patients in childhood and adolescence and to identify risk factors for impaired outcome. METHODS: We invited all BA patients between ages 1 and 20âyears followed up at Helsinki University Children's Hospital in Finland between 1 January 2019 to 31 January 2020 to participate. All participants underwent age-appropriate validated neurocognitive tests. Participants between 3.0 and 16.9âyears of age were assessed with the Movement Assessment Battery for children, version 2. Guardians of participants between ages 5 and 17 years filled the Five-to-Fifteen-Revised (5-15R) parental questionnaire. RESULTS: The mean (±standard deviation [SD]) total intelligence quotient (IQ) of the 39 participants was 91â±â15, lower compared with test norms (mean IQ 100â±â15, Pâ<â0.01). Earlier clearance of jaundice (COJ) had a positive effect on mean (±SD) total IQ (COJ <3âmonths 96â±â13 vs COJ ≥3âmonths post-portoenterostomy 84â±â13, Pâ<â0.05). Out of 30 participants assessed, 13 (43%) were either at risk or fulfilled the criteria for impaired motor development. Guardians reported elevated rates of functional difficulties affecting everyday life. There were no significant differences between native liver and liver transplanted (16/41%) groups. CONCLUSIONS: IQ is moderately, and motor scores markedly impaired in BA patients compared with normative data. Standardised cognitive and motor assessment before school-age for all BA patients is advisable to identify individuals in need of additional support.
Assuntos
Atresia Biliar , Adolescente , Adulto , Atresia Biliar/complicações , Atresia Biliar/cirurgia , Criança , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Humanos , Lactente , Portoenterostomia Hepática , Estudos Prospectivos , Adulto JovemRESUMO
AIM: To study the association between the Hammersmith Infant Neurological Examination (HINE) at age 2 years and neurocognition at age 11 years in children born very preterm. We hypothesized that the HINE at 2 years would be associated with neurocognition, that is, neurological, motor, and cognitive outcomes at 11 years. METHOD: A total of 174 children (mean gestational age 29.0wks, SD 2.7; minimum 23.0, maximum 35.9; 95 [55%] males, 79 [45%] females) born very preterm (birthweight ≤1500g/gestational age <32wks), were included in a prospective cohort recruited from 2001 to 2006 in Turku, Finland. The HINE was performed at 2 years' corrected age. Neurocognition at 11 years was assessed with the Touwen neurological examination, Movement Assessment Battery for Children, Second Edition (MABC-2), and full-scale IQ (Wechsler Intelligence Scale for Children, Fourth Edition). RESULTS: The HINE global score was associated with the results of the Touwen neurological examination (odds ratio [OR]=0.9, 95% confidence interval [CI] 0.8-0.9, p=0.001), MABC-2 (ß=1.4, 95% CI 0.7-2.2, p<0.001), and full-scale IQ (ß=1.2, 95% CI 0.8-1.7, p<0.001), even when adjusted. When children with cerebral palsy (CP) were excluded, the HINE was still associated with full-scale IQ (unadjusted ß=1.2, 95% CI 0.3-2.1, p=0.01). INTERPRETATION: A higher HINE global score at 2 years was associated with better general intelligence at 11 years even in children without CP. The HINE may be a useful tool to detect children at risk for later cognitive impairment. What this paper adds A Hammersmith Infant Neurological Examination (HINE) global score at 2 years was associated with long-term neurocognitive function. Severe cognitive impairment was significantly more common in 11-year-old children with complex minor neurological dysfunction compared to typically developing children. The HINE performed at 2 years detects risks of cognitive impairment at 11 years in children born very preterm. A higher HINE score at 2 years was associated with better general intelligence at 11 years.
Assuntos
Transtornos Cognitivos/diagnóstico , Cognição/fisiologia , Deficiências do Desenvolvimento/diagnóstico , Lactente Extremamente Prematuro , Exame Neurológico , Criança , Pré-Escolar , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Inteligência/fisiologia , MasculinoRESUMO
AIM: We explored the ability of the Hammersmith Infant Neurological Examination (HINE) to identify typical and delayed cognitive performance in a large population of infants born preterm, both with and without cerebral palsy (CP). METHOD: We conducted a retrospective study of infants born preterm who had repeated HINEs between 3 and 12 months corrected age. At 2 years, cognition was assessed using the Mental Development Index (MDI; from the Bayley Scales of Infant Development, Second Edition) and the presence and severity of CP was determined. All children were classified as cognitively typical/mildly delayed or significantly delayed (MDI <70) and CP. The predictive validity of HINE scores for significantly delayed cognitive performance, in children with and without CP, was calculated using specific cut-off scores according to age at assessment. RESULTS: Of 1229 eligible infants (gestational age 25-36wks, mean [SD] 34.9 [2.3]; 646 males, 583 females), 1108 did not develop CP, 891 had an MDI that was typical/mildly delayed, and 217 had an MDI less than 70. Of the 121 infants who developed CP, the MDI was typical in 28, mildly delayed in 27, and less than 70 in 66. HINE scores showed a good sensitivity and specificity, especially after 3 months, for detecting significantly delayed cognitive performance in infants without CP. In those who developed CP, the score was associated with their cognitive level. INTERPRETATION: The HINE provides information about the risk of delayed cognitive performance in infants born preterm with and without CP. What this paper adds The Hammersmith Infant Neurological Examination (HINE) can be used in the first year to identify infants born preterm at risk for delayed cognitive performance. Age-dependent HINE cut-off scores are proposed for detecting increased risk of delayed cognitive performance.
Assuntos
Paralisia Cerebral/diagnóstico , Transtornos Cognitivos/diagnóstico , Exame Neurológico , Feminino , Idade Gestacional , Humanos , Lactente , Recém-Nascido Prematuro , Masculino , Estudos RetrospectivosRESUMO
AIM: Prematurity has been shown to affect social competence in children and adults. Our aim was to evaluate profiles of self-reported social behaviours and loneliness in preterm- and term-born adolescents. METHODS: Preterm (≤1500 g and, or, <32 gestational weeks)- and term-born infants were recruited in Turku University Hospital from 2001 to 2006. The Multisource Assessment of Children's Social Competence Scale and the Peer Network and Dyadic Loneliness Scale were completed at the age of 11. Profiles of social competence and loneliness were labelled as low, average or high. RESULTS: A total of 172 preterm-born and 134 term-born adolescents returned the questionnaires. Most frequently, preterm adolescents reported a profile of average social competence and average levels of loneliness. Preterm-born boys reported a profile of low social functioning less often (preterm-born 36% vs. term-born 54%), and preterm-born girls reported a profile of high social functioning less frequently (preterm-born 26% vs. term-born 37%) than same-sex controls. Sex differences in social functioning profiles were smaller in preterm than term-born adolescents. CONCLUSION: The majority of young adolescents born preterm reported a high or average social functioning profile irrespective of sex. Prematurity seems to level out differences between the sexes.