Normal Development Research Articles

Effects of different types of induced neonatal inflammation on development and behavior of C57BL/6 and BTBR mice

Neuroinflammation in the early postnatal period can disturb trajectories of the completion of normal brain development and can lead to mental illnesses, such as depression, anxiety disorders, and personality disorders later in life. In our study, we focused on evaluating short- and long-term effects of neonatal inflammation induced by lipopolysaccharide, poly(I:C), or their combination in female and male C57BL/6 and BTBR mice. We chose the BTBR strain as potentially more susceptible to neonatal inflammation because these mice have behavioral, neuroanatomical, and physiological features of autism spectrum disorders, an abnormal immune response, and several structural aberrations in the brain. Our results indicated that BTBR mice are more sensitive to the influence of the neonatal immune activation (NIA) on the formation of neonatal reflexes than C57BL/6 mice are. In these experiments, the injection of lipopolysaccharide had an effect on the formation of the cliff aversion reflex in female BTBR mice. Nonetheless, NIA had no delayed effects on either social behavior or anxiety-like behavior in juvenile and adolescent BTBR and C57BL/6 mice. Altogether, our data show that NIA has mimetic-, age-, and strain-dependent effects on the development of neonatal reflexes and on exploratory activity in BTBR and C57BL/6 mice.

RUNX1 regulates promoter activity in the absence of cognate DNA binding motifs.

Runt-related transcription factor 1 (RUNX1) plays an important role in normal haematopoietic cell development and function, and its function is frequently disrupted in leukaemia. RUNX1 is widely recognised as a sequence-specific DNA binding factor that recognises the motif 5'-TG(T/C)GGT-3' in promoter and enhancer regions of its target genes. Moreover, RUNX1 fusion proteins, such as RUNX1-ETO formed by the t(8;21) translocation, retain the ability to recognise and bind to this sequence to elicit atypical gene regulatory effects on bona fide RUNX1 targets. However, our analysis of publicly available RUNX1 chromatin immunoprecipitation sequencing (ChIP-Seq) data has provided evidence challenging this dogma, revealing that this motif-specific model of RUNX1 recruitment and function is incomplete. Our analyses revealed that the majority of RUNX1 genomic localisation occurs outside of promoters, that 20% of RUNX1 binding sites lack consensus RUNX motifs, and that binding in the absence of a cognate binding site is more common in promoter regions compared to distal sites. Reporter assays demonstrate that RUNX1 can drive promoter activity in the absence of a recognised DNA binding motif, in contrast to RUNX1-ETO. RUNX1-ETO supresses activity when it is recruited to promoters containing a sequence specific motif, while interestingly, it binds but does not repress promoters devoid of a RUNX1 recognition site. These data suggest that RUNX1 regulation of target genes occurs through multiple mechanisms depending on genomic location, the type of regulatory element and mode of recruitment.

Missense mutation (C667F) in murine β-dystroglycan causes embryonic lethality, myopathy and blood-brain barrier destabilization.

Dystroglycan (DG) is an extracellular matrix receptor consisting of an α- and a β-DG subunit encoded by the DAG1 gene. The homozygous mutation (c.2006G>T, p.Cys669Phe) in β-DG causes Muscle-Eye-Brain disease with multicystic leukodystrophy in humans. In a mouse model of this primary dystroglycanopathy, approximately two-thirds of homozygous embryos fail to develop to term. Mutant mice that are born undergo a normal postnatal development but show a late-onset myopathy with partially penetrant histopathological changes and an impaired performance on an activity wheel. Their brains and eyes are structurally normal, but the localization of mutant β-DG is altered in the glial perivascular endfeet resulting in a perturbed protein composition of the blood-brain and blood-retina barrier. In addition, α- and β-DG protein levels are significantly reduced in muscle and brain of mutant mice. Due to the partially penetrant developmental phenotype of the C669F-β-DG mice, they represent a novel and highly valuable mouse model to study the molecular effects of β-DG functional alterations both during embryogenesis and in mature muscle, brain and eye, and to gain insight into the pathogenesis of primary dystroglycanopathies.

The impact of poverty and socioeconomic status on brain, behaviour, and development: a unified framework.

In this article, we, for the first time, provide a comprehensive overview and unified framework of the impact of poverty and low socioeconomic status (SES) on the brain and behaviour. While there are many studies on the impact of low SES on the brain (including cortex, hippocampus, amygdala, and even neurotransmitters) and behaviours (including educational attainment, language development, development of psychopathological disorders), prior studies did not integrate behavioural, educational, and neural findings in one framework. Here, we argue that the impact of poverty and low SES on the brain and behaviour are interrelated. Specifically, based on prior studies, due to a lack of resources, poverty and low SES are associated with poor nutrition, high levels of stress in caregivers and their children, and exposure to socio-environmental hazards. These psychological and physical injuries impact the normal development of several brain areas and neurotransmitters. Impaired functioning of the amygdala can lead to the development of psychopathological disorders, while impaired hippocampus and cortex functions are associated with a delay in learning and language development as well as poor academic performance. This in turn perpetuates poverty in children, leading to a vicious cycle of poverty and psychological/physical impairments. In addition to providing economic aid to economically disadvantaged families, interventions should aim to tackle neural abnormalities caused by poverty and low SES in early childhood. Importantly, acknowledging brain abnormalities due to poverty in early childhood can help increase economic equity. In the current study, we provide a comprehensive list of future studies to help understand the impact of poverty on the brain.

Targeting BRD4: Potential therapeutic strategy for head and neck squamous cell carcinoma (Review).

As a member of BET (bromodomain and extra-terminal) protein family, BRD4 (bromodomain‑containing protein 4) is a chromatin‑associated protein that interacts with acetylated histones and actively recruits regulatory proteins, leading to the modulation of gene expression and chromatin remodeling. The cellular and epigenetic functions of BRD4 implicate normal development, fibrosis and inflammation. BRD4 has been suggested as a potential therapeutic target as it is often overexpressed and plays a critical role in regulating gene expression programs that drive tumor cell proliferation, survival, migration and drug resistance. To address the roles of BRD4 in cancer, several drugs that specifically target BRD4 have been developed. Inhibition of BRD4 has shown promising results in preclinical models, with several BRD4 inhibitors undergoing clinical trials for the treatment of various cancers. Head and neck squamous cell carcinoma (HNSCC), a heterogeneous group of cancers, remains a health challenge with a high incidence rate and poor prognosis. Conventional therapies for HNSCC often cause adverse effects to the patients. Targeting BRD4, therefore, represents a promising strategy to sensitize HNSCC to chemo‑ and radiotherapy allowing de‑intensification of the current therapeutic regime and subsequent reduced side effects. However, further studies are required to fully understand the underlying mechanisms of action of BRD4 in HNSCC in order to determine the optimal dosing and administration of BRD4‑targeted drugs for the treatment of patients with HNSCC.

Transcription-related metabolic regulation in grafted lemon seedlings under magnesium deficiency stress

Magnesium is one of the essential nutrients for plant growth, and plays a pivotal role in plant development and metabolism. Soil magnesium deficiency is evident in citrus production, which ultimately leads to failure of normal plant growth and development, as well as decreased productivity. Citrus is mainly propagated by grafting, so it is necessary to fully understand the different regulatory mechanisms of rootstock and scion response to magnesium deficiency. Here, we characterized the differences in morphological alterations, physiological metabolism and differential gene expression between trifoliate orange rootstocks and lemon scions under normal and magnesium-deficient conditions, revealing the different responses of rootstocks and scions to magnesium deficiency. The transcriptomic data showed that differentially expressed genes were enriched in 14 and 4 metabolic pathways in leaves and roots, respectively, after magnesium deficiency treatment. And the magnesium transport-related genes MHX and MRS2 may respond to magnesium deficiency stress. In addition, magnesium deficiency may affect plant growth by affecting POD, SOD, and CAT enzyme activity, as well as altering the levels of hormones such as IAA, ABA, GA3, JA, and SA, and the expression of related responsive genes. In conclusion, our research suggests that the leaves of lemon grafted onto trifoliate orange were more significantly affected than the roots under magnesium-deficient conditions, further indicating that the metabolic imbalance of scion lemon leaves was more severe.

Impact of Maternal Environment and Inflammation on Fetal Neurodevelopment.

During intrauterine life, external stimuli including maternal nutrition, lifestyle, socioeconomic conditions, anxiety, stress, and air pollution can significantly impact fetal development. The human brain structures begin to form in the early weeks of gestation and continue to grow and mature throughout pregnancy. This review aims to assess, based on the latest research, the impact of environmental factors on fetal and neonatal brain development, showing that oxidative stress and inflammation are implied as a common factor for most of the stressors. Environmental insults can induce a maternal inflammatory state and modify nutrient supply to the fetus, possibly through epigenetic mechanisms, leading to significant consequences for brain morphogenesis and neurological outcomes. These risk factors are often synergic and mutually reinforcing. Fetal growth restriction and preterm birth represent paradigms of intrauterine reduced nutrient supply and inflammation, respectively. These mechanisms can lead to an increase in free radicals and, consequently, oxidative stress, with well-known adverse effects on the offspring's neurodevelopment. Therefore, a healthy intrauterine environment is a critical factor in supporting normal fetal brain development. Hence, healthcare professionals and clinicians should implement effective interventions to prevent and reduce modifiable risk factors associated with an increased inflammatory state and decreased nutrient supply during pregnancy.

Transcription factor DREF regulates expression of the microRNA gene bantam in Drosophila melanogaster.

The bantam gene encodes a vital microRNA and has a complex expression pattern in various tissues at different stages of Drosophila development. This microRNA is involved in the control of normal development of the ocular and wing imaginal discs, the central nervous system, and also in maintaining the undifferentiated state of stem cells in the ovaries of adult females. At the cellular level, bantam stimulates cell proliferation and prevents apoptosis. The bantam gene is a target of several conserved signaling cascades, in particular, Hippo. At the moment, at least ten proteins are known to directly regulate the expression of this gene in different tissues of Drosophila. In this study, we found that the bantam regulatory region contains motifs characteristic of binding sites for DREF, a transcription factor that regulates the expression of Hippo cascade genes. Using transgenic lines containing a full-length bantam lethality-rescuing deletion fragment and a fragment with a disrupted DREF binding site, we show that these motifs are functionally significant because their disruption at the bantam locus reduces expression levels in the larvae and ovaries of homozygous flies, which correlates with reduced vitality and fertility. The effect of DREF binding to the promoter region of the bantam gene on its expression level suggests an additional level of complexity in the regulation of expression of this microRNA. A decrease in the number of eggs laid and a shortening of the reproductive period in females when the DREF binding site in the regulatory region of the bantam gene is disrupted suggests that, through bantam, DREF is also involved in the regulation of Drosophila oogenesis.

Correlation between clinical phenotypes and genotypes among 46 children with SCN1A-related developmental epileptic encephalopathy

To explore the correlation between clinical phenotypes and genotypes among 46 children with SCN1A-related developmental epileptic encephalopathy (DEE). Clinical data of 46 children with DEE and SCN1A variants identified at the Guangzhou Women and Children's Medical Center between January 2018 and June 2022 were collected. The children were grouped based on their age of onset, clinical manifestations, neurodevelopmental status, and results of genetic testing. The correlation between SCN1A genotypes and clinical phenotypes was analyzed. Among the 46 patients, 2 children (4.35%) had developed the symptoms before 3 months of age, 42 (91.30%) were between 3 to 9 months, and 2 cases (4.35%) were after 10 months. Two cases (4.35%) presented with epilepsy of infancy with migrating focal seizures (EIMFS), while 44 (95.7%) had presented with Dravet syndrome (DS), including 28 cases (63.6%) with focal onset (DS-F), 13 cases (29.5%) with myoclonic type (DS-M), 1 case (2.27%) with generalized type (DS-G), and 2 cases (4.55%) with status epilepticus type (DS-SE). Both of the two EIMFS children had severe developmental delay, and among the DS patients, 7 cases had normal development, while the remaining had developmental delay. A total of 44 variants were identified through genetic sequencing, which included 16 missense variants and 28 truncating variants. All EIMFS children had carried the c.677C>T (p.Thr226Met) missense variant. In the DS group, there was a significant difference in the age of onset between the missense variants group and the truncating variants group (P < 0.05). Missense variants were more common in D1 (7/15, 46.7%) and pore regions (8/15, 53.3%), while truncating variants were more common in D1 (12/28, 42.9%). Children with variants outside the pore region were more likely to develop myoclonic seizures. The clinical phenotypes of DEE are diverse. There is a difference in the age of onset between individuals with truncating and missense variants in the SCN1A gene. Missense variants outside the pore region are associated with a higher incidence of myoclonic seizures.

The Role of Measuring Preoperative Social Maturation Score in Children With Additional Needs Who Underwent Cochlear Implantation.

Additional needs refer to specific requirements or support for individuals with disabilities or syndromes. Intellectual ability is a crucial outcome determinant of a cochlear implant. The social quotient (SQ) is an indirect predictor of intellectual capacity and social skills. This study aimed to investigate the clinical significance of the SQ on children with additional needs who received cochlear implants. Subjects and. This study included 24 patients with diagnosed developmental delays and syndromes, who demonstrated SQ scores of <70. Preoperative social skills were evaluated using the SQ. All patients underwent cochlear implantation (CI) surgery before 7 years of age. Outcomes were evaluated using the Infant-Toddler Meaningful Auditory Integration Scale (IT-MAIS) and Categories of Auditory Performance (CAP) scores. Data were collected through a retrospective chart review. Children were categorized into three groups based on their SQ. There were no correlations between the preoperative SQ and IT-MAIS or CAP scores at 2 and 5 years of follow-up postoperatively. The CI outcomes of children with low SQ (<70) differed from those with normal development (SQ>70). In the low-SQ group, inner ear anomalies were observed in 10 (41.7%) patients. Although not statistically significant, these children exhibited a trend of lower average outcomes than children without inner ear anomalies. CI outcomes in children with additional needs positively affected auditory performance. Postoperative auditory and language skills tended to improve slowly in children with additional needs and a lower SQ. Over time, development gradually became more comparable to the other groups of children. However, this improvement was less than that observed in children without additional needs. Our findings support CI for children with additional needs as part of long-term auditory rehabilitation following surgery.

TGFβ overcomes FGF-induced transinhibition of EGFR in lens cells to enable fibrotic secondary cataract.

To cause vision-disrupting fibrotic secondary cataract (PCO), lens epithelial cells that survive cataract surgery must migrate to the posterior of the lens capsule and differentiate into myofibroblasts. During this process, the cells become exposed to the FGF that diffuses out of the vitreous body. In normal development, such relatively high levels of FGF induce lens epithelial cells to differentiate into lens fiber cells. It has been a mystery as to how lens cells could instead undergo a mutually exclusive cell fate, namely epithelial to myofibroblast transition, in the FGF-rich environment of the posterior capsule. We and others have reported that the ability of TGFβ to induce lens cell fibrosis requires the activity of endogenous ErbBs. We show here that lens fiber-promoting levels of FGF induce desensitization of ErbB1 (EGFR) that involves its phosphorylation on threonine 669 mediated by both ERK and p38 activity. Transinhibition of ErbB1 by FGF is overcome by a time-dependent increase in ErbB1 levels induced by TGFβ, the activation of which is increased after cataract surgery. Our studies provide a rationale for why TGFβ upregulates ErbB1 in lens cells and further support the receptor as a therapeutic target for PCO.

Pax6 isoforms shape eye development: Insights from developmental stages and organoid models

Pax6 is a critical transcription factor involved in the development of the central nervous system. However, in humans, mutations in Pax6 predominantly result in iris deficiency rather than neurological phenotypes. This may be attributed to the distinct functions of Pax6 isoforms, Pax6a and Pax6b. In this study, we investigated the spatial and temporal expression patterns of Pax6 isoforms during different stages of mouse eye development. We observed a strong correlation between Pax6a expression and the neuroretina gene Sox2, while Pax6b showed a high correlation with iris-component genes, including the mesenchymal gene Foxc1. During early patterning from E10.5, Pax6b was expressed in the hinge of the optic cup and neighboring mesenchymal cells, whereas Pax6a was absent in these regions. At E14.5, both Pax6a and Pax6b were expressed in the future iris and ciliary body, coinciding with the integration of mesenchymal cells and Mitf-positive cells in the outer region. From E18.5, Pax6 isoforms exhibited distinct expression patterns as lineage genes became more restricted. To further validate these findings, we utilized ESC-derived eye organoids, which recapitulated the temporal and spatial expression patterns of lineage genes and Pax6 isoforms. Additionally, we found that the spatial expression patterns of Foxc1 and Mitf were impaired in Pax6b-mutant ESC-derived eye organoids. This in vitro eye organoids model suggested the involvement of Pax6b-positive local mesodermal cells in iris development. These results provide valuable insights into the regulatory roles of Pax6 isoforms during iris and neuroretina development and highlight the potential of ESC-derived eye organoids as a tool for studying normal and pathological eye development.

Hepatokine ITIH3 protects against hepatic steatosis by downregulating mitochondrial bioenergetics and de novo lipogenesis

Recent studies demonstrate that liver secretory proteins, also known as hepatokines, regulate normal development, obesity, and simple steatosis to non-alcoholic steatohepatitis (NASH) progression. Using a panel of ∼100 diverse inbred strains of mice and a cohort of bariatric surgery patients, we found that one such hepatokine, inter-trypsin inhibitor heavy chain 3 (ITIH3), was progressively lower in severe non-alcoholic fatty liver disease (NAFLD) disease states highlighting an inverse relationship between Itih3/ITIH3 expression and NAFLD severity. Follow-up animal and cell culture models demonstrated that hepatic ITIH3 overexpression lowered liver triglyceride and lipid droplet accumulation, respectively. Conversely, ITIH3 knockdown in mice increased the liver triglyceride in two independent NAFLD models. Mechanistically, ITIH3 reduced mitochondrial respiration and this, in turn, reduced liver triglycerides, via downregulated de novo lipogenesis. This was accompanied by increased STAT1 signaling and Stat3 expression, both of which are known to protect against NAFLD/NASH. Our findings indicate hepatokine ITIH3 as a potential biomarker and/or treatment for NAFLD.

Lifelong absence of microglia alters hippocampal glutamatergic networks but not synapse and spine density.

Microglia sculpt developing neural circuits by eliminating excess synapses in a process called synaptic pruning, by removing apoptotic neurons, and by promoting neuronal survival. To elucidate the role of microglia during embryonic and postnatal brain development, we used a mouse model deficient in microglia throughout life by deletion of the fms-intronic regulatory element (FIRE) in the Csf1r locus. Surprisingly, young adult Csf1rΔFIRE/ΔFIRE mice display no changes in excitatory and inhibitory synapse number and spine density of CA1 hippocampal neurons compared with Csf1r+/+ littermates. However, CA1 neurons are less excitable, receive less CA3 excitatory input and show altered synaptic properties, but this does not affect novel object recognition. Cytokine profiling indicates an anti-inflammatory state along with increases in ApoE levels and reactive astrocytes containing synaptic markers in Csf1rΔFIRE/ΔFIRE mice. Notably, these changes in Csf1rΔFIRE/ΔFIRE mice closely resemble the effects of acute microglial depletion in adult mice after normal development. Our findings suggest that microglia are not mandatory for synaptic pruning, and that in their absence pruning can be achieved by other mechanisms.

Pleomorphic adenoma gene (PLAG1) in reproduction and implication for embryonic survival in cattle: A review.

The pleomorphic adenoma gene (PLAG1) encodes a DNA-binding, C2H2 zinc finger protein which acts as a transcription factor that regulates the expression of diverse genes across different organs and tissues; hence, the name pleomorphic. Rearrangements of the PLAG1 gene, and/or overexpression, are associated with benign tumors and cancers in a variety of tissues. This is best described for pleomorphic adenoma of the salivary glands in humans. The most notable expression of PLAG1 occurs during embryonic and fetal development, with lesser expression after birth. Evidence has accumulated of a role for PLAG1 protein in normal early embryonic development and placentation in mammals. PLAG1 protein influences the expression of the IGF2 gene and production of IGF2 protein. IGF2 is an important mitogen in ovarian follicles/oocytes, embryos, and fetuses. The PLAG1-IGF2 axis, therefore, provides one pathway whereby PLAG1 protein can influence embryonic survival and pregnancy. PLAG1 also influences over 1,000 other genes in embryos including those associated with ribosomal assembly and proteins. Brahman (Bos indicus) heifers homozygous for the PLAG1 variant, rs109815800 (G>T), show greater fertility than contemporary heifers with either one, or no copy, of the variant. Greater fertility in heifers homozygous for rs109815800 could be the result of early puberty and/or greater embryonic survival. The present review first looks at the broader roles of the PLAG1 gene and PLAG1 protein and then focuses on the emerging role of PLAG1/PLAG1 in embryonic development and pregnancy. A deeper understanding of factors which influence embryonic development is required for the next transformational increase in embryonic survival and successful pregnancy for both in vivo and in vitro derived embryos in cattle.

Multi‐Scale Ice Inhibition Platform Enables Full‐Cycle Cryogenic Protection for Mouse Oocyte

AbstractCryopreservation of metaphase II (MII) oocytes is crucial to preserve female fertility. However, the existing vitrification technology just provides partial cryogenic protection for oocytes and must use high concentrations of toxic penetrating cryoprotective agents (CPAs, up to 4.8 M). Here, a multi‐scale ice inhibition platform is proposed, which effectively suppresses ice crystal morphology, ice recrystallization (IR), temperature gradient, and devitrification. This platform achieves mouse oocyte survival rate of 98.6% using the low concentration of CPA (3.1 M) while also possessing batch oocyte cryopreservation ability. In contrast, recovered oocytes show a much more modest variation of genes compared with the conventional method (85 vs. 1396 genes), retaining normal fertilization, embryonic development, and birth to healthy offspring. Diverging from the conventional vitrification method with partial cryogenic protection capability, this platform introduces full‐cycle ice inhibition, offering promising prospects for achieving high‐quality and scalable fertility preservation.

A preliminary study on the normal values of the thoracic Haller index in children.

The Haller index (HI) is widely utilized as a quantitative indicator to assess the extent of the pectus excavatum (PE) deformity, which is the most common chest wall abnormality in children. Both preoperative correction planning and postoperative follow-up need to be based on the standard of normal thoracic growth and development. However, there is currently no established reference range for the HI in children. Consequently, the goal of this study was to conduct a preliminary investigation of normal HI values among children to understand thoracic developmental characteristics. Chest computed tomography images obtained from January 2012 to March 2022 were randomly selected from the imaging system of the Children's Hospital of Chongqing Medical University. We divided the images of children into a total of 19 groups: aged 0-3 months (1 group), 4-12 months (1 group) and 1 year to 17 years (17 groups), with 50 males and 50 females, totaling 100 children in each group. HI was measured in the plane where the lowest point of the anterior thoracic wall was located and statistically analysed using SPSS 26.0 software. A total of 1900 patients were included in the study. Our results showed that HI, transverse diameter and anterior-posterior diameter were positively correlated with age (P < 0.05). Using age as the independent variable and HI as the dependent variable, the best-fit regression equations were HI-male = 2.047 * Age0.054(R2 = 0.276, P<0.0001) and HI-female = 2.045 * Age0.067(R2 = 0.398, P<0.0001). Males had significantly larger thoracic diameters than females, and there was little difference in the HI between the 2 sexes. The HI rapidly increases during the neonatal period, slowly increases during infancy and stops increasing during puberty, with no significant differences between the sexes.

A review of the effect of iron supplementation on the gut microbiota of children in developing countries and the impact of prebiotics.

Iron is essential for many physiological functions of the body, and it is required for normal growth and development. Iron deficiency (ID) is the most common form of micronutrient malnutrition and is particularly prevalent in infants and young children in developing countries. Iron supplementation is considered the most effective strategy to combat the risk of ID and ID anaemia (IDA) in infants, although iron supplements cause a range of deleterious gut-related problems in malnourished children. The purpose of this review is to assess the available evidence on the effect of iron supplementation on the gut microbiota during childhood ID and to further assess whether prebiotics offer any benefits for iron supplementation. Prebiotics are well known to improve gut-microbial health in children, and recent reports indicate that prebiotics can mitigate the adverse gut-related effects of iron supplementation in children with ID and IDA. Thus, provision of prebiotics alongside iron supplements has the potential for an enhanced strategy for combatting ID and IDA among children in the developing world. However, further understanding is required before the benefit of such combined treatments of ID in nutritionally deprived children across populations can be fully confirmed. Such enhanced understanding is of high relevance in resource-poor countries where ID, poor sanitation and hygiene, alongside inadequate access to good drinking water and poor health systems, are serious public health concerns.

Melatonin and sexual development of adolescents with type 1 diabetes

Objective — to study the level of daily melatonin excretion in adolescents with type 1 diabetes mellitus (DM1) at the stages of puberty, taking into account the course of puberty. Materials and methods. The investigation involved 172 patients with DM1 aged 9—18 years (85 boys and 87 girls), who stayed in the Endocrinology Department of the SI «Institute for Children and Adolescents Health Care of the NAMS of Ukraine» for examinations and treatment. The DM1 duration was 1 to 10 years. With account of the level of sexual development at the time of examination, adolescents were divided into the following subgroups: prepuberty (T1); early puberty (T2); puberty itself (T3); late puberty (T4). The nature of sexual maturation was assessed with account of the norms for the corresponding age. The nature of melatonin production was assessed by the excretion of its main metabolite — 6-­sulfatoxymelatonin in daily urine, which was determined by fluorometric method. Statistical processing of the results was carried out using application packages Microsoft Excel and SPSS 17.0. Results and discussion. The effects of puberty on melatonin production have been determined, with its increase during puberty and late puberty. It has been proven that violation of the puberty course is accompanied with changes in the melatonin levels, corresponding to the degree of sexual development of girls and boys with DM1. In conditions of accelerated puberty, the melatonin level increases, and it decreases in case of slowdown sexual development. In girls of 14—18 years old, the lowest melatonin levels were determined in patients with delayed sexual development and primary amenorrhea. During sexual maturation, formation of epiphyseal­pituitary­gonadal and epiphyseal­pituitary­thyroid links takes place, their nature changes in the course puberty. Conclusions. In adolescents with DM1, the age-related dynamics of daily melatonin excretion during puberty is preserved, with an increase in its levels during late puberty. Melatonin levels in patients with DM1 depend on the sexual maturation course, and they are altered in case of its disorders. Regardless of gender, at delayed sexual development significantly lower melatonin levels were registered in comparison with patients with normal sexual development. The nature of correlations between melatonin and hormonal indicators depends on the level of an adolescent’s sexual development and gender.

Functional identification of bacterial spermine, thermospermine, norspermine, norspermidine, spermidine, and N1-aminopropylagmatine synthases

Spermine synthase is an aminopropyltransferase that adds an aminopropyl group to the essential polyamine spermidine to form tetraamine spermine, needed for normal human neural development, plant salt and drought resistance, and yeast CoA biosynthesis. We functionally identify for the first time bacterial spermine synthases, derived from phyla Bacillota, Rhodothermota, Thermodesulfobacteriota, Nitrospirota, Deinococcota and Pseudomonadota. We also identify bacterial aminopropyltransferases that synthesize the spermine same mass isomer thermospermine, from phyla Cyanobacteriota, Thermodesulfobacteriota, Nitrospirota, Dictyoglomota, Armatimonadota and Pseudomonadota, including the human opportunistic pathogen Pseudomonas aeruginosa. Most of these bacterial synthases were capable of synthesizing spermine or thermospermine from the diamine putrescine, and so possess also spermidine synthase activity. We found that most thermospermine synthases could synthesize tetraamine norspermine from triamine norspermidine, i.e., they are potential norspermine synthases. This finding could explain the enigmatic source of norspermine in bacteria. Some of the thermospermine synthases could synthesize norspermidine from diamine 1,3-diaminopropane, demonstrating that they are potential norspermidine synthases. Of 18 bacterial spermidine synthases identified, 17 were able to aminopropylate agmatine to form N1-aminopropylagmatine, including the spermidine synthase of Bacillus subtilis, a species known to be devoid of putrescine. This suggests that the N1-aminopropylagmatine pathway for spermidine biosynthesis, which bypasses putrescine, may be far more widespread than realized and may be the default pathway for spermidine biosynthesis in species encoding L-arginine decarboxylase for agmatine production. Some thermospermine synthases were able to aminopropylate N1-aminopropylagmatine to form N12-guanidinothermospermine. Our study reveals an unsuspected diversification of bacterial polyamine biosynthesis, and suggests a more prominent role for agmatine.