Hemizygous variants in protein phosphatase 1 regulatory subunit 3F (PPP1R3F) are associated with a neurodevelopmental disorder characterized by developmental delay, intellectual disability and autistic features.

Protein phosphatase 1 regulatory subunit 3F (PPP1R3F) is a member of the glycogen targeting subunits (GTSs), which belong to the large group of regulatory subunits of protein phosphatase 1 (PP1), a major eukaryotic serine/threonine protein phosphatase that regulates diverse cellular processes. Here, we describe the identification of hemizygous variants in PPP1R3F associated with a novel X-linked recessive neurodevelopmental disorder in 13 unrelated individuals. This disorder is characterized by developmental delay, mild intellectual disability, neurobehavioral issues such as autism spectrum disorder, seizures and other neurological findings including tone, gait and cerebellar abnormalities. PPP1R3F variants segregated with disease in affected hemizygous males that inherited the variants from their heterozygous carrier mothers. We show that PPP1R3F is predominantly expressed in brain astrocytes and localizes to the endoplasmic reticulum in cells. Glycogen content in PPP1R3F knockout astrocytoma cells appears to be more sensitive to fluxes in extracellular glucose levels than in wild-type cells, suggesting that PPP1R3F functions in maintaining steady brain glycogen levels under changing glucose conditions. We performed functional studies on nine of the identified variants and observed defects in PP1 binding, protein stability, subcellular localization and regulation of glycogen metabolism in most of them. Collectively, the genetic and molecular data indicate that deleterious variants in PPP1R3F are associated with a new X-linked disorder of glycogen metabolism, highlighting the critical role of GTSs in neurological development. This research expands our understanding of neurodevelopmental disorders and the role of PP1 in brain development and proper function.

Inhibiting proBDNF to mature BDNF conversion leads to ASD-like phenotypes in vivo.

Autism Spectrum Disorders (ASD) comprise a range of early age-onset neurodevelopment disorders with genetic heterogeneity. Most ASD related genes are involved in synaptic function, which is regulated by mature brain-derived neurotrophic factor (mBDNF) and its precursor proBDNF in a diametrically opposite manner: proBDNF inhibits while mBDNF potentiates synapses. Here we generated a knock-in mouse line (BDNFmet/leu) in which the conversion of proBDNF to mBDNF is attenuated. Biochemical experiments revealed residual mBDNF but excessive proBDNF in the brain. Similar to other ASD mouse models, the BDNFmet/leu mice showed reduced dendritic arborization, altered spines, and impaired synaptic transmission and plasticity in the hippocampus. They also exhibited ASD-like phenotypes, including stereotypical behaviors and deficits in social interaction. Moreover, the plasma proBDNF/mBDNF ratio was significantly increased in ASD patients compared to normal children in a case-control study. Thus, deficits in proBDNF to mBDNF conversion in the brain may contribute to ASD-like behaviors, and plasma proBDNF/mBDNF ratio may be a potential biomarker for ASD.

Expanding the spectrum of phenotypes for MPDZ: Report of four unrelated families and review of the literature.

MPDZ, a gene with diverse functions mediating cell-cell junction interactions, receptor signaling, and binding multivalent scaffold proteins, is associated with a spectrum of clinically heterogeneous phenotypes with biallelic perturbation. Despite its clinical relevance, the mechanistic underpinnings of these variants remain elusive, underscoring the need for extensive case series and functional investigations. In this study, we conducted a systematic review of cases in the literature through two electronic databases following the PRISMA guidelines. We selected nine studies, including 18 patients, with homozygous or compound heterozygous variants in MPDZ and added five patients from four unrelated families with novel MPDZ variants. To evaluate the role of Mpdz on hearing, we analyzed available auditory electrophysiology data from a knockout murine model (Mpdzem1(IMPC)J/em1(IMPC)J) generated by the International Mouse Phenotyping Consortium. Using exome and genome sequencing, we identified three families with compound heterozygous variants, and one family with a homozygous frameshift variant. MPDZ-related disease is clinically heterogenous with hydrocephaly, vision impairment, hearing impairment and cardiovascular disease occurring most frequently. Additionally, we describe two unrelated patients with spasticity, expanding the phenotypic spectrum. Our murine analysis of the Mpdzem1(IMPC)J/em1(IMPC)J allele showed severe hearing impairment. Overall, we expand understanding of MPDZ-related phenotypes and highlight hearing impairment and spasticity among the heterogeneous phenotypes.

Histological chorioamnionitis and pathological stages on very preterm infant outcomes.

AIMS: Histological chorioamnionitis (HCA) is a condition linked to preterm birth and neonatal infection and its relationship with various pathological stages in extremely preterm neonates, and with their associated short- and long-term consequences, remains a subject of research. This study investigated the connection between different pathological stages of HCA and both short-term complications and long-term outcomes in preterm infants born at or before 32 weeks of gestational age. METHODS: Preterm infants born at ≤ 32 weeks of gestation who underwent placental pathology evaluation and were followed-up at 18-24 months of corrected age were included. Neonates were classified based on their exposure to HCA and were further subdivided into different groups according to maternal inflammatory responses (MIR) and fetal inflammatory responses (FIR) stages. We compared short-term complications during their hospital stay between the HCA-exposed and -unexposed groups and examined the influence of HCA stages on long-term outcomes. RESULTS: The HCA group exhibited distinct characteristics such as higher rates of premature rupture of membranes > 18 h, reduced amniotic fluid, early-onset sepsis, bronchopulmonary dysplasia and intraventricular haemorrhage (IVH) grades III-IV (P < 0.05). The moderate-severe HCA group displayed lower gestational age, lower birth weight and higher incidence of IVH (grades III-IV) and preterm sepsis compared with the mild HCA group (P < 0.05). After adjusting for confounders, the MIR stages 2-3 group showed associations with cognitive impairment and cerebral palsy (P < 0.05), and the FIR stages 2-3 group also showed poor long-term outcomes and cognitive impairment (P < 0.05). CONCLUSIONS: Moderate-severe HCA was associated with increased early-onset sepsis, severe IVH and poor long-term outcomes, including cognitive impairment and cerebral palsy. Vigilant prevention strategies are warranted for severe HCA cases in order to mitigate poorer clinical outcomes.

Cerebral Palsy Heterogeneity: Clinical Characteristics and Diagnostic Significance from a Large-Sample Analysis.

INTRODUCTION: Cerebral palsy (CP) is a nonprogressive movement disorder resulting from a prenatal or perinatal brain injury that benefits from early diagnosis and intervention. The timing of early CP diagnosis remains controversial, necessitating analysis of clinical features in a substantial cohort. METHODS: We retrospectively reviewed medical records from a university hospital, focusing on children aged ≥24 months or followed up for ≥24 months and adhering to the International Classification of Diseases-10 for diagnosis and subtyping. RESULTS: Among the 2012 confirmed CP cases, 68.84% were male and 51.44% had spastic diplegia. Based on the Gross Motor Function Classification System (GMFCS), 62.38% were in levels I and II and 19.88% were in levels IV and V. Hemiplegic and diplegic subtypes predominantly fell into levels I and II, while quadriplegic and mixed types were mainly levels IV and V. White matter injuries appeared in 46.58% of cranial MRI findings, while maldevelopment was rare (7.05%). Intellectual disability co-occurred in 43.44% of the CP cases, with hemiplegia having the lowest co-occurrence (20.28%, 58/286) and mixed types having the highest co-occurrence (73.85%, 48/65). Additionally, 51.67% (697/1,349) of the children with CP aged ≥48 months had comorbidities. CONCLUSIONS: This study underscores white matter injury as the primary CP pathology and identifies intellectual disability as a common comorbidity. Although CP can be identified in infants under 1 year old, precision in diagnosis improves with development. These insights inform early detection and tailored interventions, emphasizing their crucial role in CP management.

Integrative analysis of γδT cells and dietary factors reveals predictive values for autism spectrum disorder in children.

BACKGROUND: Autism spectrum disorder (ASD) includes a range of multifactorial neurodevelopmental disabilities characterized by a variable set of neuropsychiatric symptoms. Immunological abnormalities have been considered to play important roles in the pathogenesis of ASD, but it is still unknown which abnormalities are more prominent. METHODS: A total of 105 children with ASD and 105 age and gender-matched typically developing (TD) children were recruited. An eating and mealtime behavior questionnaire, dietary habits, and the Bristol Stool Scale were investigated. The immune cell profiles in peripheral blood were analyzed by flow cytometry, and cytokines (IFN-γ, IL-8, IL-10, IL-17A, and TNF-α) in plasma were examined by Luminex assay. The obtained results were further validated using an external validation cohort including 82 children with ASD and 51 TD children. RESULTS: Compared to TD children, children with ASD had significant eating and mealtime behavioral changes and gastrointestinal symptoms characterized by increased food fussiness and emotional eating, decreased fruit and vegetable consumption, and increased stool astriction. The proportion of γδT cells was significantly higher in children with ASD than TD children (ß: 0.156; 95% CI: 0.888 âˆ¼ 2.135, p < 0.001) even after adjusting for gender, eating and mealtime behaviors, and dietary habits. In addition, the increased γδT cells were evident in all age groups (age < 48 months: ß: 0.288; 95% CI: 0.420 âˆ¼ 4.899, p = 0.020; age ≥ 48 months: ß: 0.458; 95% CI: 0.694 âˆ¼ 9.352, p = 0.024), as well as in boys (ß: 0.174; 95% CI: 0.834 âˆ¼ 2.625, p < 0.001) but not in girls. These findings were also confirmed by an external validation cohort. Furthermore, IL-17, but not IFN-γ, secretion by the circulating γδT cells was increased in ASD children. Machine learning revealed that the area under the curve in nomogram plots for increased γδT cells combined with eating behavior/dietary factors was 0.905, which held true in both boys and girls and in all the age groups of ASD children. The decision curves showed that children can receive significantly higher diagnostic benefit within the threshold probability range from 0 to 1.0 in the nomogram model. CONCLUSIONS: Children with ASD present with divergent eating and mealtime behaviors and dietary habits as well as gastrointestinal symptoms. In peripheral blood, γδT cells but not αßT cells are associated with ASD. The increased γδT cells combined with eating and mealtime behavior/dietary factors have a high value for assisting in the diagnosis of ASD.

Screening inflammatory protein biomarkers on premature infants with necrotizing enterocolitis.

OBJECTIVE: This study aimed to explore potential inflammatory biomarkers for early prediction of necrotizing enterocolitis (NEC) in premature infants. METHODS: Plasma samples were collected from premature infants with NEC (n = 30), sepsis (n = 29), and controls without infection (n = 29). The 92 inflammatory-related proteins were assessed via high-throughput OLINK proteomics platform. RESULTS: There were 11 inflammatory proteins that significate differences (p < 0.05) among NEC, sepsis and control preterm infants, which include IL-8, TRAIL, IL-24, MMP-10, CCL20, CXCL1, OPG, TSLP, MCP-4, TNFSF14 and LIF. A combination of these 11 proteins could serve as differential diagnosis between NEC and control infants (AUC = 0.972), or between NEC and sepsis infants (AUC = 0.881). Furthermore, the combination of IL-8, OPG, MCP-4, IL-24, LIF and CCL20 could distinguish Stage II and III of NEC (AUC = 0.977). Further analysis showed the combination of IL-8, IL-24 and CCL20 have the best prediction value for NEC and control (AUC = 0.947), NEC and sepsis (AUC = 0.838) and different severity of NEC (AUC = 0.842). CONCLUSION: Inflammatory proteins were different expressed in premature infants with NEC compared with controls or sepsis. Combining these proteins provide a higher diagnostic potential for preterm NEC infants.

Interaction between AIF and CHCHD4 Regulates Respiratory Chain Biogenesis.

Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein that, beyond its apoptotic function, is required for the normal expression of major respiratory chain complexes. Here we identified an AIF-interacting protein, CHCHD4, which is the central component of a redox-sensitive mitochondrial intermembrane space import machinery. Depletion or hypomorphic mutation of AIF caused a downregulation of CHCHD4 protein by diminishing its mitochondrial import. CHCHD4 depletion sufficed to induce a respiratory defect that mimicked that observed in AIF-deficient cells. CHCHD4 levels could be restored in AIF-deficient cells by enforcing its AIF-independent mitochondrial localization. This modified CHCHD4 protein reestablished respiratory function in AIF-deficient cells and enabled AIF-deficient embryoid bodies to undergo cavitation, a process of programmed cell death required for embryonic morphogenesis. These findings explain how AIF contributes to the biogenesis of respiratory chain complexes, and they establish an unexpected link between the vital function of AIF and the propensity of cells to undergo apoptosis.

An overlooked subset of Cx3cr1wt/wt microglia in the Cx3cr1CreER-Eyfp/wt mouse has a repopulation advantage over Cx3cr1CreER-Eyfp/wt microglia following microglial depletion.

BACKGROUND: Fluorescent reporter labeling and promoter-driven Cre-recombinant technologies have facilitated cellular investigations of physiological and pathological processes, including the widespread use of the Cx3cr1CreER-Eyfp/wt mouse strain for studies of microglia. METHODS: Immunohistochemistry, Flow Cytometry, RNA sequencing and whole-genome sequencing were used to identify the subpopulation of microglia in Cx3cr1CreER-Eyfp/wt mouse brains. Genetically mediated microglia depletion using Cx3cr1CreER-Eyfp/wtRosa26DTA/wt mice and CSF1 receptor inhibitor PLX3397 were used to deplete microglia. Primary microglia proliferation and migration assay were used for in vitro studies. RESULTS: We unexpectedly identified a subpopulation of microglia devoid of genetic modification, exhibiting higher Cx3cr1 and CX3CR1 expression than Cx3cr1CreER-Eyfp/wtCre+Eyfp+ microglia in Cx3cr1CreER-Eyfp/wt mouse brains, thus termed Cx3cr1highCre-Eyfp- microglia. This subpopulation constituted less than 1% of all microglia under homeostatic conditions, but after Cre-driven DTA-mediated microglial depletion, Cx3cr1highCre-Eyfp- microglia escaped depletion and proliferated extensively, eventually occupying one-third of the total microglial pool. We further demonstrated that the Cx3cr1highCre-Eyfp- microglia had lost their genetic heterozygosity and become homozygous for wild-type Cx3cr1. Therefore, Cx3cr1highCre-Eyfp- microglia are Cx3cr1wt/wtCre-Eyfp-. Finally, we demonstrated that CX3CL1-CX3CR1 signaling regulates microglial repopulation both in vivo and in vitro. CONCLUSIONS: Our results raise a cautionary note regarding the use of Cx3cr1CreER-Eyfp/wt mouse strains, particularly when interpreting the results of fate mapping, and microglial depletion and repopulation studies.

Biallelic variants in HPDL cause pure and complicated hereditary spastic paraplegia.

Human 4-hydroxyphenylpyruvate dioxygenase-like (HPDL) is a putative iron-containing non-heme oxygenase of unknown specificity and biological significance. We report 25 families containing 34 individuals with neurological disease associated with biallelic HPDL variants. Phenotypes ranged from juvenile-onset pure hereditary spastic paraplegia to infantile-onset spasticity and global developmental delays, sometimes complicated by episodes of neurological and respiratory decompensation. Variants included bona fide pathogenic truncating changes, although most were missense substitutions. Functionality of variants could not be determined directly as the enzymatic specificity of HPDL is unknown; however, when HPDL missense substitutions were introduced into 4-hydroxyphenylpyruvate dioxygenase (HPPD, an HPDL orthologue), they impaired the ability of HPPD to convert 4-hydroxyphenylpyruvate into homogentisate. Moreover, three additional sets of experiments provided evidence for a role of HPDL in the nervous system and further supported its link to neurological disease: (i) HPDL was expressed in the nervous system and expression increased during neural differentiation; (ii) knockdown of zebrafish hpdl led to abnormal motor behaviour, replicating aspects of the human disease; and (iii) HPDL localized to mitochondria, consistent with mitochondrial disease that is often associated with neurological manifestations. Our findings suggest that biallelic HPDL variants cause a syndrome varying from juvenile-onset pure hereditary spastic paraplegia to infantile-onset spastic tetraplegia associated with global developmental delays.

Outcome Analysis of Severe Hyperbilirubinemia in Neonates Undergoing Exchange Transfusion.

OBJECTIVE: Severe neonatal hyperbilirubinemia can cause neurological disability or mortality if not effectively managed. Exchange transfusion (ET) is an efficient treatment to prevent bilirubin neurotoxicity. The purpose of this study was to evaluate outcomes in severe neonatal hyperbilirubinemia with ET and to identify the potential risk factors for poor outcomes. METHODS: Newborns of ≥28 weeks of gestational age with severe hyperbilirubinemia who underwent ET from January 2015 to August 2019 were included. Demographic data were recorded and analyzed according to follow-up outcomes at 12 months of corrected age. Poor outcomes were defined as death due to bilirubin encephalopathy or survival with at least one of the following complications: cerebral palsy, psychomotor retardation (psychomotor developmental index < 70), mental retardation (mental developmental index < 70), or hearing impairment. RESULTS: A total of 524 infants were eligible for recruitment to the study, and 62 infants were lost to follow-up. The outcome data from 462 infants were used for grouping analysis, of which 398 cases (86.1%) had normal outcomes and 64 cases (13.9%) suffered poor outcomes. Bivariate logistic regression analysis showed that peak total serum bilirubin (TSB) (odds ratio [OR] = 1.011, 95% confidence interval [CI] = 1.008-1.015, p = 0.000) and sepsis (OR = 4.352, 95% CI = 2.013-9.409, p < 0.001) were associated with poor outcomes of hyperbilirubinemia. Receiver operator characteristic curve analysis showed that peak TSB ≥452.9 µmol/L could predict poor outcomes of severe hyperbilirubinemia. CONCLUSION: Peak TSB and sepsis were associated with poor outcomes in infants with severe hyperbilirubinemia, and peak TSB ≥452.9 µmol/L could predict poor outcomes.

The Role of Autophagy in Childhood Central Nervous System Tumors.

OPINION STATEMENT: Autophagy is a physiological process that occurs in normal tissues. Under external environmental pressure or internal environmental changes, cells can digest part of their contents through autophagy in order to reduce metabolic pressure or remove damaged organelles. In cancer, autophagy plays a paradoxical role, acting as a tumor suppressor-by removing damaged organelles and inhibiting inflammation or by promoting genome stability and the tumor-adaptive responses-as a pro-survival mechanism to protect cells from stress. In this article, we review the autophagy-dependent mechanisms driving childhood central nervous system tumor cell death, malignancy invasion, chemosensitivity, and radiosensitivity. Autophagy inhibitors and inducers have been developed, and encouraging results have been achieved in autophagy modulation, suggesting that these might be potential therapeutic agents for the treatment of pediatric central nervous system (CNS) tumors.

The effect of vitamin D supplementation in treatment of children with autism spectrum disorder: a systematic review and meta-analysis of randomized controlled trials.

Objective: The effect of vitamin D supplementation on the risk of Autism Spectrum Disorder (ASD) is conflicting. The aim of this study was to estimate the efficacy of vitamin D supplementation on ASD in children.Methods: We conducted a meta-analysis of randomized controlled trials (RCTs) in which vitamin D supplementation was used as a therapy in children with ASD. The PubMed, PsychINFO, Cochrane CENTRAL library, Web of Science, and Cinahl databases were searched from inception to March 20, 2019, for all publications on vitamin D and ASD with no restrictions. Studies involving individuals aged <18 years diagnosed with ASD and with all functional outcomes assessed by measurement scales for ASD were included. Mean differences were pooled, and a meta-analysis was performed using a random-effects model due to differences between the individual RCTs.Results: There were five RCTs with 349 children with ASD in the review, of which three RCTs were included in the meta-analysis. Vitamin D supplementation indicated a small but significant improvement in hyperactivity scores (pooled MD: -3.20; 95% CI: [-6.06, -0.34]) with low heterogeneity (I2 = 10%, p = 0.33), but there were no other statistically significant differences in ASD symptoms between groups as measured by validated scales.Conclusion: Vitamin D supplementation appears to be beneficial for hyperactivity but not for core symptoms or other co-existing behaviors and conditions of ASD. Future RCTs with large sample sizes examining the effect of vitamin D supplementation on ASD among individuals with low serum vitamin D levels at baseline are needed.

Changes in the live birth profile in Henan, China: A hospital registry-based study.

BACKGROUND: Preterm complications and neonatal asphyxia are the leading causes of death in those under 5 years of age. However, little information exists for the province of Henan, China. The purpose of this study was to explore changes in the live birth profile in a provincial hospital over the past 32 years in Henan, China. METHODS: A retrospective analysis was conducted to reveal the characteristics of live neonates from 1987 to 2018. RESULTS: There were 118 253 live births during the period, including 19 798 (16.74%) preterm births. The neonatal death rate was 6.45‰, and the top risk factor was preterm birth complications and birth asphyxia. Before 1998, neonatal death occurred primarily among term infants. Between 1999 and 2018, preterm infants, especially extreme and very preterm infants with very low birthweight, constituted more than half of all mortalities, and the preterm birth rate increased from 5.94% in 1999 to 16.69% in 2018. The risk factors associated with preterm birth were being male (aOR = 1.18, P < 0.001), advanced maternal age (>35 years old; aOR = 1.08, P = 0.008), gravidity ≥2 (aOR = 1.15, P < 0.001), parity ≥2 (aOR = 1.50, P < 0.001), placenta previa (aOR = 7.41, P < 0.001), twin or multiple births (aOR = 10.63, P < 0.001), hypertension (aOR = 2.08, P < 0.001), and rupture of membrane (aOR = 5.03, P < 0.001). CONCLUSIONS: The preterm birth rate has increased over the past 32 years from 4.98% to 16.69% in a provincial hospital in China. Preterm birth was the leading reason for neonatal death, and birth asphyxia was the major risk factor for death in term infants.

Epigenetic restoration of voltage-gated potassium channel Kv1.2 alleviates nerve injury-induced neuropathic pain.

Voltage-gated potassium channels (Kv) are important regulators of neuronal excitability for its role of regulating resting membrane potential and repolarization. Recent studies show that Kv channels participate in neuropathic pain, but the detailed underlying mechanisms are far from being clear. In this study, we used siRNA, miR-137 agomir, and antagomir to regulate the expression of Kv1.2 in spinal cord and dorsal root ganglia (DRG) of naïve and chronic constriction injury (CCI) rats. Kv currents and neuron excitability in DRG neurons were examined by patch-clamp whole-cell recording to verify the change in Kv1.2 function. The results showed that Kv1.2 was down-regulated in DRG and spinal dorsal horn (SDH) by CCI. Knockdown of Kv1.2 by intrathecally injecting Kcna2 siRNA induced significant mechanical and thermal hypersensitivity in naïve rats. Concomitant with the down-regulation of Kv1.2 was an increase in the expression of the miR-137. The targeting and regulating of miR-137 on Kcna2 was verified by dual-luciferase reporter system and intrathecal injecting miR-137 agomir. Furthermore, rescuing the expression of Kv1.2 in CCI rats, achieved through inhibiting miR-137, restored the abnormal Kv currents and excitability in DRG neurons, and alleviated mechanical allodynia and thermal hyperalgesia. These results indicate that the miR-137-mediated Kv1.2 impairment is a crucial etiopathogenesis for the nerve injury-induced neuropathic pain and can be a novel potential therapeutic target for neuropathic pain management.

Luminal polyethylene glycol solution delays the onset of preservation injury in the human intestine.

The organ damage incurred during the cold storage (CS) of intestinal grafts has short and long-term consequences. Animal studies suggest that additional luminal preservation (LP) with polyethylene glycol (PEG) may alleviate this damage. This study aims to validate these findings using human intestines. Ileal segments, perfused intravascularly with IGL-1 solution, were procured from 32 multiorgan donors and divided into two parts: one containing a PEG 3350-based solution introduced luminally (LP group) and another one without luminal treatment (control). Sampling was performed after 4 h, 8 h, 14 h, and 24 h of CS. Histology was assessed using the Chiu/Park score. Tight junctions (TJ), several inflammatory markers, and transcription factors were examined by immunofluorescence, ddPCR, and western blot. Tissue water content (edema) was also measured. Apoptotic activity was assessed with caspase -2, -3, and -9 assays. LP significantly lowered mucosal injury at all time points. Redistribution of TJ proteins occurred earlier and more severely in the control group. After 24 h of CS, LP intestines showed an emerging unfolding protein response. Increased caspase-3 and -9 activity was found in the control group. The current results indicate that luminal PEG is safe and effective in reducing damage to the intestinal epithelium during CS.

De Novo Pathogenic Variants in CACNA1E Cause Developmental and Epileptic Encephalopathy with Contractures, Macrocephaly, and Dyskinesias.

Developmental and epileptic encephalopathies (DEEs) are severe neurodevelopmental disorders often beginning in infancy or early childhood that are characterized by intractable seizures, abundant epileptiform activity on EEG, and developmental impairment or regression. CACNA1E is highly expressed in the central nervous system and encodes the α1-subunit of the voltage-gated CaV2.3 channel, which conducts high voltage-activated R-type calcium currents that initiate synaptic transmission. Using next-generation sequencing techniques, we identified de novo CACNA1E variants in 30 individuals with DEE, characterized by refractory infantile-onset seizures, severe hypotonia, and profound developmental impairment, often with congenital contractures, macrocephaly, hyperkinetic movement disorders, and early death. Most of the 14, partially recurring, variants cluster within the cytoplasmic ends of all four S6 segments, which form the presumed CaV2.3 channel activation gate. Functional analysis of several S6 variants revealed consistent gain-of-function effects comprising facilitated voltage-dependent activation and slowed inactivation. Another variant located in the domain II S4-S5 linker results in facilitated activation and increased current density. Five participants achieved seizure freedom on the anti-epileptic drug topiramate, which blocks R-type calcium channels. We establish pathogenic variants in CACNA1E as a cause of DEEs and suggest facilitated R-type calcium currents as a disease mechanism for human epilepsy and developmental disorders.

Umbilical cord blood cells for the treatment of preterm white matter injury: Potential effects and treatment options.

Preterm birth is a global public health problem. A large number of preterm infants survive with preterm white matter injury (PWMI), which leads to neurological deficits, and has multifaceted etiology, clinical course, monitoring, and outcomes. The principal upstream insults leading to PWMI initiation are hypoxia-ischemia and infection and/or inflammation and the key target cells are late oligodendrocyte precursor cells. Current PWMI treatments are mainly supportive, and thus have little effect in terms of protecting the immature brain or repairing injury to improve long-term outcomes. Umbilical cord blood (UCB) cells comprise abundant immunomodulatory and stem cells, which have the potential to reduce brain injury, mainly due to anti-inflammatory and immunomodulatory mechanisms, and also through their release of neurotrophic or growth factors to promote endogenous neurogenesis. In this review, we briefly summarize PWMI pathogenesis and pathophysiology, and the specific properties of different cell types in UCB. We further explore the potential mechanism by which UCB can be used to treat PWMI, and discuss the advantages of and potential issues related to UCB cell therapy. Finally, we suggest potential future studies of UCB cell therapy in preterm infants.

The different mechanisms of peripheral and central TLR4 on chronic postsurgical pain in rats.

Chronic postsurgical pain (CPSP) is a common complication after surgery; however, the underlying mechanisms of CPSP are poorly understood. As one of the most important inflammatory pathways, the Toll-like receptor 4/nuclear factor-kappa B (TLR4/NF-κB) signaling pathway plays an important role in chronic pain. However, the precise role of the TLR4/NF-κB signaling pathway in CPSP remains unclear. In the present study, we established a rat model of CPSP induced by skin/muscle incision and retraction (SMIR) and verified the effects and mechanisms of central and peripheral TLR4 and NF-κB on hyperalgesia in SMIR rats. The results showed that TLR4 expression was increased in both the spinal dorsal horn and dorsal root ganglia (DRGs) of SMIR rats. However, the TLR4 expression pattern in the spinal cord was different from that in DRGs. In the spinal cord, TLR4 was expressed in both neurons and microglia, whereas it was expressed in neurons but not in satellite glial cells in DRGs. Further results demonstrate that the central and peripheral TLR4/NF-κB signaling pathway is involved in the SMIR-induced CPSP by different mechanisms. In the peripheral nervous system, we revealed that the TLR4/NF-κB signaling pathway induced upregulation of voltage-gated sodium channel 1.7 (Nav1.7) in DRGs, triggering peripheral hyperalgesia in SMIR-induced CPSP. In the central nervous system, the TLR4/NF-κB signaling pathway participated in SMIR-induced CPSP by activating microglia in the spinal cord. Ultimately, our findings demonstrated that activation of the peripheral and central TLR4/NF-κB signaling pathway involved in the development of SMIR-induced CPSP.

Cranial irradiation alters neuroinflammation and neural proliferation in the pituitary gland and induces late-onset hormone deficiency.

Cranial radiotherapy induces endocrine disorders and reproductive abnormalities, particularly in long-term female cancer survivors, and this might in part be caused by injury to the pituitary gland, but the underlying mechanisms are unknown. The aim of this study was to investigate the influence of cranial irradiation on the pituitary gland and related endocrine function. Female Wistar rat pups on postnatal day 11 were subjected to a single dose of 6 Gy whole-head irradiation, and hormone levels and organ structure in the reproductive system were examined at 20 weeks after irradiation. We found that brain irradiation reduced cell proliferation and induced persistent inflammation in the pituitary gland. The whole transcriptome analysis of the pituitary gland revealed that apoptosis and inflammation-related pathways were up-regulated after irradiation. In addition, irradiation led to significantly decreased levels of the pituitary hormones, growth hormone, adrenocorticotropic hormone, thyroid-stimulating hormone and the reproductive hormones testosterone and progesterone. To conclude, brain radiation induces reduction of pituitary and reproduction-related hormone secretion, this may due to reduced cell proliferation and increased pituitary inflammation after irradiation. Our results thus provide additional insight into the molecular mechanisms underlying complications after head irradiation and contribute to the discovery of preventive and therapeutic strategies related to brain injury following irradiation.