Diabetes tipo 1 en pediatría durante la pandemia por COVID-19: tiempo de evolución de síntomas y formas de presentación en un centro de referencia / Type 1 diabetes in pediatrics during the COVID-19 pandemic: Time from symptom onset and forms of presentation at a referral hospital

Introducción. La pandemia por COVID-19 afectó la atención de pacientes con diabetes mellitus tipo 1 (DM1). Además, se reportó un aumento de cetoacidosis diabética (CAD) como forma de diagnóstico. Objetivos. Evaluar si durante la pandemia por COVID-19 se modificaron el tiempo de evolución de síntomas, las causas de hospitalización por DM1 y la proporción de formas graves, y describir la infección por SARS-CoV-2 en estos pacientes. Población y métodos. Estudio transversal que incluyó pacientes menores de 19 años hospitalizados por DM1 en un centro pediátrico de referencia de marzo de 2018 a agosto de 2019 (prepandemia) y de marzo de 2020 a agosto de 2021 (pandemia). Resultados. Se analizaron 231 internaciones, 135 prepandemia y 96 en pandemia. Los pacientes con debut diabético presentaron menor tiempo de evolución de síntomas en pandemia que en prepandemia (18,8 ± 10,2 vs. 52,1 ±12,1 días, respectivamente; p <0,001). Las hospitalizaciones por todas las formas de debut diabético y el debut con CAD fueron más frecuentes en pandemia que en prepandemia (59,4 % vs. 39,3 %; OR 2,3; IC95% 1,3-3,8; p = 0,003); y (40,6 % vs. 20,7 %; OR 2,6; IC95% 1,4-5,2; p = 0,006) respectivamente. La proporción de formas graves de CAD no se modificó entre ambos períodos (48,1 % vs. 59,9 %; p = 0,3). Solo 6 pacientes presentaron infección por SARS-CoV-2; 3 fueron formas graves. Conclusión. Durante la pandemia, disminuyó el tiempo de evolución de síntomas y aumentó la frecuencia de hospitalizaciones por debut de DM1, con mayor proporción de CAD. No se modificó la proporción de formas graves de CAD

Introduction. The COVID-19 pandemic impacted on the health care of patients with type 1 diabetes mellitus (DM1). An increase in diabetic ketoacidosis (DKA) as a form of diagnosis was reported. Objectives. To assess whether there were changes in the time from symptom onset, the causes of hospitalization due to DM1, and the proportion of severe forms, and to describe SARS-CoV-2 infection in these patients. Population and methods. Cross-sectional study in patients younger than 19 years hospitalized due to DM1 from March 2018 to August 2019 (pre-pandemic) and from March 2020 to August 2021 (pandemic). Results. The assessment included 135 hospitalizations in the pre-pandemic period and 96 during the pandemic. The time from symptom onset during the pandemic in those with debutof diabetes was shorter than in the pre-pandemic period (18.8 ± 10.2 versus 52.1 ± 12.1 days, respectively; p < 0.001). Hospitalizations due to all forms of diabetes debut and debut with DKA were more common during the pandemic than before it (59.4% versus 39.3%; odds ratio [OR]: 2.3; 95% confidence interval [CI]: 1.3­3.8; p = 0.003 and 40.6% versus 20.7%; OR: 2.6; 95% CI: 1.4­5.2; p = 0.006, respectively). Severe forms of DKA did not change between both periods (48.1% versus 59.9%; p = 0.3). Only 6 patients developed SARS-CoV-2 infection; 3 were severe. Conclusion. During the pandemic, the time from symptom onset decreased and the frequency of hospitalizations due to debut of DM1 increased. The proportion of severe forms of DKA did not change.

Type 1 diabetes in pediatrics during the COVID-19 pandemic: Time from symptom onset and forms of presentation at a referral hospital. / Diabetes tipo 1 en pediatría durante la pandemia por COVID-19: tiempo de evolución de síntomas y formas de presentación en un centro de referencia.

Introduction. The COVID-19 pandemic impacted on the health care of patients with type 1 diabetes mellitus (DM1). An increase in diabetic ketoacidosis (DKA) as a form of diagnosis was reported. Objectives. To assess whether there were changes in the time from symptom onset, the causes of hospitalization due to DM1, and the proportion of severe forms, and to describe SARS-CoV-2 infection in these patients. Population and methods. Cross-sectional study in patients younger than 19 years hospitalized due to DM1 from March 2018 to August 2019 (pre-pandemic) and from March 2020 to August 2021 (pandemic). Results. The assessment included 135 hospitalizations in the pre-pandemic period and 96 during the pandemic. The time from symptom onset during the pandemic in those with debut of diabetes was shorter than in the pre-pandemic period (18.8 ± 10.2 versus 52.1 ± 12.1 days, respectively; p < 0.001). Hospitalizations due to all forms of diabetes debut and debut with DKA were more common during the pandemic than before it (59.4% versus 39.3%; odds ratio [OR]: 2.3; 95% confidence interval [CI]: 1.3-3.8; p = 0.003 and 40.6% versus 20.7%; OR: 2.6; 95% CI: 1.4-5.2; p = 0.006, respectively). Severe forms of DKA did not change between both periods (48.1% versus 59.9%; p = 0.3). Only 6 patients developed SARS-CoV-2 infection; 3 were severe. Conclusion. During the pandemic, the time from symptom onset decreased and the frequency of hospitalizations due to debut of DM1 increased. The proportion of severe forms of DKA did not change.

Introducción. La pandemia por COVID-19 afectó la atención de pacientes con diabetes mellitus tipo 1 (DM1). Además, se reportó un aumento de cetoacidosis diabética (CAD) como forma de diagnóstico. Objetivos. Evaluar si durante la pandemia por COVID-19 se modificaron el tiempo de evolución de síntomas, las causas de hospitalización por DM1 y la proporción de formas graves, y describir la infección por SARS-CoV-2 en estos pacientes. Población y métodos. Estudio transversal que incluyó pacientes menores de 19 años hospitalizados por DM1 en un centro pediátrico de referencia de marzo de 2018 a agosto de 2019 (prepandemia) y de marzo de 2020 a agosto de 2021 (pandemia). Resultados. Se analizaron 231 internaciones, 135 prepandemia y 96 en pandemia. Los pacientes con debut diabético presentaron menor tiempo de evolución de síntomas en pandemia que en prepandemia (18,8 ± 10,2 vs. 52,1 ±12,1 días, respectivamente; p <0,001). Las hospitalizaciones por todas las formas de debut diabético y el debut con CAD fueron más frecuentes en pandemia que en prepandemia (59,4 % vs. 39,3 %; OR 2,3; IC95% 1,3-3,8; p = 0,003); y (40,6 % vs. 20,7 %; OR 2,6; IC95% 1,4-5,2; p = 0,006) respectivamente. La proporción de formas graves de CAD no se modificó entre ambos períodos (48,1 % vs. 59,9 %; p = 0,3). Solo 6 pacientes presentaron infección por SARS-CoV-2; 3 fueron formas graves. Conclusión. Durante la pandemia, disminuyó el tiempo de evolución de síntomas y aumentó la frecuencia de hospitalizaciones por debut de DM1, con mayor proporción de CAD. No se modificó la proporción de formas graves de CAD.

Evolution of lysine-specific demethylase 1 and REST corepressor gene families and their molecular interaction.

Lysine-specific demethylase 1A (LSD1) binds to the REST corepressor (RCOR) protein family of corepressors to erase transcriptionally active marks on histones. Functional diversity in these complexes depends on the type of RCOR included, which modulates the catalytic activity of the complex. Here, we studied the duplicative history of the RCOR and LSD gene families and analyzed the evolution of their interaction. We found that RCOR genes are the product of the two rounds of whole-genome duplications that occurred early in vertebrate evolution. In contrast, the origin of the LSD genes traces back before to the divergence of animals and plants. Using bioinformatics tools, we show that the RCOR and LSD1 interaction precedes the RCOR repertoire expansion that occurred in the last common ancestor of jawed vertebrates. Overall, we trace LSD1-RCOR complex evolution and propose that animal non-model species offer advantages in addressing questions about the molecular biology of this epigenetic complex.

Síndrome de Bardet Biedl: a propósito de un caso / Bardet Biedl syndrome: a case report

El síndrome de Bardet Biedl es un síndrome genético de herencia autosómica recesiva con compromiso multisistémico y gran variabilidad en su presentación clínica; son características la obesidad, la polidactilia, el hipogonadismo y las alteraciones renales, visuales y cognitivas. Pertenece a las llamadas ciliopatías. El diagnóstico es clínico y puede ser confirmado por estudios genéticos. No existe un tratamiento específico de la patología; se requiere un abordaje multidisciplinario. Se presenta el caso de una paciente de 13 años con obesidad e hiperfagia, diabetes tipo 2, hipotiroidismo, polidactilia, alteraciones del aprendizaje y alteraciones visuales. Se le realizó un panel genético para obesidad en el que se detectaron dos variantes heterocigotas patológicas en el gen BBS2.

Bardet Biedl syndrome is an autosomal recessive ciliopathie. It is a pleiotropic disorder characterised by retinal dystrophy, renal dysfunction, polydactyly, obesity, cognitive deficitand hypogenitalism. Diagnosis is based on clinical features. Molecular genetic testing is available. There is no specific treatment, a multidisciplinary approach is required. We report the case of a 13-year-old female patient with obesity and hyperphagia, type 2 diabetes, hypothyroidism, polydactyly,cognitive deficit and visual impairment. A multigenic panel allowed the identification of two heterozygous pathogenic variants in the BBS2 gene.

[Bardet Biedl syndrome: a case report]. / Síndrome de Bardet Biedl: a propósito de un caso.

Bardet Biedl syndrome is an autosomal recessive ciliopathie. It is a pleiotropic disorder characterised by retinal dystrophy, renal dysfunction, polydactyly, obesity, cognitive deficit and hypogenitalism. Diagnosis is based on clinical features. Molecular genetic testing is available. There is no specific treatment, a multidisciplinary approach is required. We report the case of a 13-year-old female patient with obesity and hyperphagia, type 2 diabetes, hypothyroidism, polydactyly, cognitive deficit and visual impairment. A multigenic panel allowed the identification of two heterozygous pathogenic variants in the BBS2 gene.

El síndrome de Bardet Biedl es un síndrome genético de herencia autosómica recesiva con compromiso multisistémico y gran variabilidad en su presentación clínica; son características la obesidad, la polidactilia, el hipogonadismo y las alteraciones renales, visuales y cognitivas. Pertenece a las llamadas ciliopatías. El diagnóstico es clínico y puede ser confirmado por estudios genéticos. No existe un tratamiento específico de la patología; se requiere un abordaje multidisciplinario. Se presenta el caso de una paciente de 13 años con obesidad e hiperfagia, diabetes tipo 2, hipotiroidismo, polidactilia, alteraciones del aprendizaje y alteraciones visuales. Se le realizó un panel genético para obesidad en el que se detectaron dos variantes heterocigotas patológicas en el gen BBS2.

OPA1 Modulates Mitochondrial Ca2+ Uptake Through ER-Mitochondria Coupling.

Autosomal Dominant Optic Atrophy (ADOA), a disease that causes blindness and other neurological disorders, is linked to OPA1 mutations. OPA1, dependent on its GTPase and GED domains, governs inner mitochondrial membrane (IMM) fusion and cristae organization, which are central to oxidative metabolism. Mitochondrial dynamics and IMM organization have also been implicated in Ca2+ homeostasis and signaling but the specific involvements of OPA1 in Ca2+ dynamics remain to be established. Here we studied the possible outcomes of OPA1 and its ADOA-linked mutations in Ca2+ homeostasis using rescue and overexpression strategies in Opa1-deficient and wild-type murine embryonic fibroblasts (MEFs), respectively and in human ADOA-derived fibroblasts. MEFs lacking Opa1 required less Ca2+ mobilization from the endoplasmic reticulum (ER) to induce a mitochondrial matrix [Ca2+] rise ([Ca2+]mito). This was associated with closer ER-mitochondria contacts and no significant changes in the mitochondrial calcium uniporter complex. Patient cells carrying OPA1 GTPase or GED domain mutations also exhibited altered Ca2+ homeostasis, and the mutations associated with lower OPA1 levels displayed closer ER-mitochondria gaps. Furthermore, in Opa1 -/- MEF background, we found that acute expression of OPA1 GTPase mutants but no GED mutants, partially restored cytosolic [Ca2+] ([Ca2+]cyto) needed for a prompt [Ca2+]mito rise. Finally, OPA1 mutants' overexpression in WT MEFs disrupted Ca2+ homeostasis, partially recapitulating the observations in ADOA patient cells. Thus, OPA1 modulates functional ER-mitochondria coupling likely through the OPA1 GED domain in Opa1 -/- MEFs. However, the co-existence of WT and mutant forms of OPA1 in patients promotes an imbalance of Ca2+ homeostasis without a domain-specific effect, likely contributing to the overall ADOA progress.

Cross-talk between dopamine D1 and corticotropin releasing factor type 2 receptors leads to occlusion of their ERK1/2 signaling.

One manner in which G protein-coupled receptors potentiate, increase, and change their functionality is through the formation of heteromers in a specific cellular context. Previously, we have shown that dopamine D1 receptor (D1R) and the corticotropin releasing factor receptor type-2α (CRF2α) heteromerize in HEK293T cells, enabling D1R to mobilize intracellular calcium in response to D1R agonists. In this study, we further investigated the pharmacological properties of the CRF2α-D1R heteromer and the consequences of the heteromerization in their signaling and subcellular localization when both receptors are co-expressed in HEK293T cells. Using immunoprecipitation assays, we observed that the addition of 10 µM dopamine in the incubation medium significantly decreased the amount of CRF2α on the cell surface of cells expressing both receptors. The presence of agonists of both receptors increased the interaction between CRF2α and D1R as assessed by co-immunoprecipitation. However, the presence of agonists of both receptors resulted in a lesser efficient activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase. Using a synaptosomal preparation of rat prefrontal cortex devoid of post-synaptic elements, we found that CRF2α and D1R co-localize in synaptic terminals of the rat medial prefrontal cortex and that the simultaneous activation of both receptors also occluded phosphorylation of extracellular signal-regulated kinase. These results strengthen the idea that the heteromer CRF2a-D1R is an entity functionally different from each receptor that composes it and suggests that its formation is enhanced by CRF and dopamine co-transmission, as occurs in stress and addiction.

Inhibitory Control of Basolateral Amygdalar Transmission to the Prefrontal Cortex by Local Corticotrophin Type 2 Receptor.

BACKGROUND: Basolateral amygdalar projections to the prefrontal cortex play a key role in modulating behavioral responses to stress stimuli. Among the different neuromodulators known to impact basolateral amygdalar-prefrontal cortex transmission, the corticotrophin releasing factor (CRF) is of particular interest because of its role in modulating anxiety and stress-associated behaviors. While CRF type 1 receptor (CRFR1) has been involved in prefrontal cortex functioning, the participation of CRF type 2 receptor (CRFR2) in basolateral amygdalar-prefrontal cortex synaptic transmission remains unclear. METHODS: Immunofluorescence anatomical studies using rat prefrontal cortex synaptosomes devoid of postsynaptic elements were performed in rats with intra basolateral amygdalar injection of biotinylated dextran amine. In vivo microdialysis and local field potential recordings were used to measure glutamate extracellular levels and changes in long-term potentiation in prefrontal cortex induced by basolateral amygdalar stimulation in the absence or presence of CRF receptor antagonists. RESULTS: We found evidence for the presynaptic expression of CRFR2 protein and mRNA in prefrontal cortex synaptic terminals originated from basolateral amygdalar. By means of microdialysis and electrophysiological recordings in combination with an intra-prefrontal cortex infusion of the CRFR2 antagonist antisauvagine-30, we were able to determine that CRFR2 is functionally positioned to limit the strength of basolateral amygdalar transmission to the prefrontal cortex through presynaptic inhibition of glutamate release. CONCLUSIONS: Our study shows for the first time to our knowledge that CRFR2 is expressed in basolateral amygdalar afferents projecting to the prefrontal cortex and exerts an inhibitory control of prefrontal cortex responses to basolateral amygdalar inputs. Thus, changes in CRFR2 signaling are likely to disrupt the functional connectivity of the basolateral amygdalar-prefrontal cortex pathway and associated behavioral responses.

CRF binding protein facilitates the presence of CRF type 2α receptor on the cell surface.

Corticotropin releasing factor binding protein (CRF-BP) was originally recognized as CRF sequestering protein. However, its differential subcellular localization in different brain nuclei suggests that CRF-BP may have additional functions. There is evidence that CRF-BP potentiates CRF and urocortin 1 actions through CRF type 2 receptors (CRF2R). CRF2R is a G protein-coupled receptor (GPCR) that is found mainly intracellularly as most GPCRs. The access of GPCRs to the cell surface is tightly regulated by escort proteins. We hypothesized that CRF-BP binds to CRF2R, exerting an escort protein role. We analyzed the colocalization of CRF-BP and CRF2R in cultured rat mesencephalic neurons, and the localization and interaction of heterologous expressed CRF-BP and CRF2αR in yeast, human embryonic kidney 293, and rat pheochromocytoma 12 cells. Our results showed that CRF-BP and CRF2R naturally colocalize in the neurites of cultured mesencephalic neurons. Heterologous expression of each protein showed that CRF-BP was localized mainly in secretory granules and CRF2αR in the endoplasmic reticulum. In contrast, CRF-BP and CRF2αR colocalized when both proteins are coexpressed. Here we show that CRF-BP physically interacts with the CRF2αR but not the CRF2ßR isoform, increasing CRF2αR on the cell surface. Thus, CRF-BP emerges as a GPCR escort protein increasing the understanding of GPCR trafficking.

Reduced dopamine and glutamate neurotransmission in the nucleus accumbens of quinpirole-sensitized rats hints at inhibitory D2 autoreceptor function.

Dopamine from the ventral tegmental area and glutamate from several brain nuclei converge in the nucleus accumbens (NAc) to drive motivated behaviors. Repeated activation of D2 receptors with quinpirole (QNP) induces locomotor sensitization and compulsive behaviors, but the mechanisms are unknown. In this study, in vivo microdialysis and fast scan cyclic voltammetry in adult anesthetized rats were used to investigate the effect of repeated QNP on dopamine and glutamate neurotransmission within the NAc. Following eight injections of QNP, a significant decrease in phasic and tonic dopamine release was observed in rats that displayed locomotor sensitization. Either a systemic injection or the infusion of QNP into the NAc decreased dopamine release, and the extent of this effect was similar in QNP-sensitized and control rats, indicating that inhibitory D2 autoreceptor function is maintained despite repeated activation of D2 receptors and decreased dopamine extracellular levels. Basal extracellular levels of glutamate in the NAc were also significantly lower in QNP-treated rats than in controls. Moreover, the increase in NAc glutamate release induced by direct stimulation of medial prefrontal cortex was significantly lower in QNP-sensitized rats. Together, these results indicate that repeated activation of D2 receptors disconnects NAc from medial prefrontal cortex and ventral tegmental area. Repeated administration of the dopamine D2 receptor agonist quinpirole (QNP) induces locomotor sensitization. We found that the NAc of QNP-sensitized rats has reduced glutamate levels coming from prefrontal cortex together with a decreased phasic and tonic dopamine neurotransmission but a conserved presynaptic D2 receptor function. We suggest that locomotor sensitization is because of increased affinity state of D2 post-synaptic receptors.

Characterizing HSF1 Binding and Post-Translational Modifications of hsp70 Promoter in Cultured Cortical Neurons: Implications in the Heat-Shock Response.

Causes of lower induction of Hsp70 in neurons during heat shock are still a matter of debate. To further inquire into the mechanisms regulating Hsp70 expression in neurons, we studied the activity of Heat Shock Factor 1 (HSF1) and histone posttranslational modifications (PTMs) at the hsp70 promoter in rat cortical neurons. Heat shock induced a transient and efficient translocation of HSF1 to neuronal nuclei. However, no binding of HSF1 at the hsp70 promoter was detected while it bound to the hsp25 promoter in cortical neurons during heat shock. Histone PTMs analysis showed that the hsp70 promoter harbors lower levels of histone H3 and H4 acetylation in cortical neurons compared to PC12 cells under basal conditions. Transcriptomic profiling data analysis showed a predominant usage of cryptic transcriptional start sites at hsp70 gene in the rat cerebral cortex, compared with the whole brain. These data support a weaker activation of hsp70 canonical promoter. Heat shock increased H3Ac at the hsp70 promoter in PC12 cells, which correlated with increased Hsp70 expression while no modifications occurred at the hsp70 promoter in cortical neurons. Increased histone H3 acetylation by Trichostatin A led to hsp70 mRNA and protein induction in cortical neurons. In conclusion, we found that two independent mechanisms maintain a lower induction of Hsp70 in cortical neurons. First, HSF1 fails to bind specifically to the hsp70 promoter in cortical neurons during heat shock and, second, the hsp70 promoter is less accessible in neurons compared to non-neuronal cells due to histone deacetylases repression.

Nur transcription factors in stress and addiction.

The Nur transcription factors Nur77 (NGFI-B, NR4A1), Nurr1 (NR4A2), and Nor-1 (NR4A3) are a sub-family of orphan members of the nuclear receptor superfamily. These transcription factors are products of immediate early genes, whose expression is rapidly and transiently induced in the central nervous system by several types of stimuli. Nur factors are present throughout the hypothalamus-pituitary-adrenal (HPA) axis where are prominently induced in response to stress. Drugs of abuse and stress also induce the expression of Nur factors in nuclei of the motivation/reward circuit of the brain, indicating their participation in the process of drug addiction and in non-hypothalamic responses to stress. Repeated use of addictive drugs and chronic stress induce long-lasting dysregulation of the brain motivation/reward circuit due to reprogramming of gene expression and enduring alterations in neuronal function. Here, we review the data supporting that Nur transcription factors are key players in the molecular basis of the dysregulation of neuronal circuits involved in chronic stress and addiction.

Nurr1 regulates RET expression in dopamine neurons of adult rat midbrain.

Genesis of midbrain dopamine (DA) neurons depends on Nurr1, a nuclear receptor expressed during development and adulthood in these neurons. Nurr1 is required for the expression of genes of dopaminergic phenotype such as tyrosine hydroxylase and DA transporter. The expression of the tyrosine kinase receptor RET also depends on Nurr1 during development. However, it is unknown whether RET expression is regulated by Nurr1 during adulthood, and the mechanism by which Nurr1 regulates RET expression. Using an adeno-associated vector-delivered anti-Nurr1 ribozyme, we knocked-down Nurr1 expression unilaterally in the substantia nigra (SN) of adult rats. Animals injected with the ribozyme displayed a 57.3% decrease in Nurr1 mRNA in the SN accompanied by decreased DA extracellular levels in the striatum. RET mRNA in the injected SN and RET protein in the ipsilateral striatum decreased 76.9% and 47%, respectively. Tyrosine hydroxylase and DA transporter mRNA did not change in Nurr1 knocked-down SN. Nurr1 induced the transcription of the human RET promoter in cell type and concentration-dependent manner. Nurr1 induction of RET promoter is independent of NBRE elements. These results show that the expression of RET in rat adult SN is regulated by Nurr1 and suggest that RET is a transcriptional target of this nuclear receptor.