Edward Quadros - Academia.edu (original) (raw)

Papers by Edward Quadros

Molecular Psychiatry, Oct 18, 2016

We sought to determine whether high-dose folinic acid improves verbal communication in children w... more We sought to determine whether high-dose folinic acid improves verbal communication in children with non-syndromic autism spectrum disorder (ASD) and language impairment in a double-blind placebo control setting. Forty-eight children (mean age 7 years 4 months; 82% male) with ASD and language impairment were randomized to receive 12 weeks of high-dose folinic acid (2 mg kg − 1 per day, maximum 50 mg per day; n = 23) or placebo (n = 25). Children were subtyped by glutathione and folate receptor-α autoantibody (FRAA) status. Improvement in verbal communication, as measured by a ability-appropriate standardized instrument, was significantly greater in participants receiving folinic acid as compared with those receiving placebo, resulting in an effect of 5.7 (1.0,10.4) standardized points with a medium-to-large effect size (Cohen's d = 0.70). FRAA status was predictive of response to treatment. For FRAA-positive participants, improvement in verbal communication was significantly greater in those receiving folinic acid as compared with those receiving placebo, resulting in an effect of 7.3 (1.4,13.2) standardized points with a large effect size (Cohen's d = 0.91), indicating that folinic acid treatment may be more efficacious in children with ASD who are FRAA positive. Improvements in subscales of the Vineland Adaptive Behavior Scale, the Aberrant Behavior Checklist, the Autism Symptom Questionnaire and the Behavioral Assessment System for Children were significantly greater in the folinic acid group as compared with the placebo group. There was no significant difference in adverse effects between treatment groups. Thus, in this small trial of children with non-syndromic ASD and language impairment, treatment with high-dose folinic acid for 12 weeks resulted in improvement in verbal communication as compared with placebo, particularly in those participants who were positive for FRAAs.

bioRxiv (Cold Spring Harbor Laboratory), Aug 16, 2021

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial ... more This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

bioRxiv (Cold Spring Harbor Laboratory), Jan 12, 2022

FTY720 (fingolimod) is a sphingosine 1-phosphate (S1P) receptor modulator and sphingosine analogu... more FTY720 (fingolimod) is a sphingosine 1-phosphate (S1P) receptor modulator and sphingosine analogue approved for multiple sclerosis (MS) therapy, which can functionally antagonize the S1P receptor, S1P1. Vitamin B12 (B12) deficiency produces neurological manifestations resembling MS. Here, we report a new mechanism where FTY720 suppresses neuroinflammation by regulating B12 metabolic pathways. Nuclear RNA-seq of c-Fos-activated astrocytes (called ieAstrocytes) from experimental autoimmune encephalomyelitis (EAE) spinal cords identified up-regulation of CD320, a transcobalamin 2 (TCN2)-B12 receptor, by S1P1 inhibition. CD320 was reduced in MS plaques. Deficiency of CD320 or dietary B12 worsened EAE and eliminated FTY720's efficacy, while concomitantly down-regulating type I interferon signaling. TCN2 functioned as a chaperone for FTY720 and sphingosine, which induced astrocytic CD320 internalization. An accompanying paper identified a requirement for astrocyte sphingosine kinases in FTY720 efficacy and its altered expression in MS brains, molecularly linking MS and B12 deficiency that can be accessed by sphingolipid/fingolimod metabolic pathways.

Research Square (Research Square), Jun 16, 2023

Folate de ciency can lead to a myriad of disruptions in neurodevelopment including neural tube de... more Folate de ciency can lead to a myriad of disruptions in neurodevelopment including neural tube defects, developmental anomalies, and functional de cits, such as autism spectrum disorder (ASD). Folate receptor alpha (FRα) is the primary transporter of folate from the mother to the fetus and into the brain. A major subset of the ASD patients and their family members have autoantibodies against FRα that can block folate transport. Therefore, we investigated the effect of exposure to folate receptor alpha antibodies during fetal development, on behavioral de cits in the offspring in a rat model and determined if their de cits are passed on to a subsequent generation; thus, contributing to inheritance of the behavioral phenotype. We have produced a rat folate receptor alpha speci c antibody (FRαAb) that when injected intraperitoneally into a dam on gestation day (GD)8, produces a litter with behavioral de cits in social communication, social interaction, including learning, memory, and cognition. Using this model, we tested the litter directly exposed to FRαAb and bred the offspring that had an affected phenotype to produce a litter that was not directly exposed to FRαAb. We observed social communication de cits and de cits in learning performance in both generations which provides preliminary evidence to indicate transmission of a behavioral phenotype associated with the FRαAb exposure to the next generation. This work supports the growing evidence that an altered maternal immune and/or micronutrient environment has a generational effect on ASD offspring, likely transmitted by non-Mendelian inheritance.

Seminars in Pediatric Neurology, Oct 1, 2020

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder that currently has ... more Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder that currently has no approved medical therapy to address core symptoms or underling pathophysiological processes. Several compounds are under development that address both underlying pathophysiological abnormalities and core ASD symptoms. This article reviews one of these treatments, d,l-leucovorin calcium (also known as folinic acid) for treatment of folate pathway abnormalities in children with ASD. Folate is a water-soluble B vitamin that is essential for normal neurodevelopment and abnormalities in the folate and related pathways have been identified in children with ASD. One of these abnormalities involves a partial blockage in the ability of folate to be transported into the brain utilizing the primary transport mechanism, the folate receptor alpha. Autoantibodies which interfere with the function of the folate receptor alpha called folate receptor alpha autoantibodies have been identified in 58%-76% of children with ASD and independent studies have demonstrated that blood titers of these autoantibodies correlate with folate levels in the cerebrospinal fluid. Most significantly, case-series, open-label, and single and double-blind placebo-controlled studies suggest that d,l-leucovorin, a reduced folate that can bypass the blockage at the folate receptor alpha by using the reduced folate carrier, an alternate pathway, can substantially improve particular symptoms in children with ASD, especially those positive for folate receptor alpha autoantibodies. This article reviews the current evidence for treating core and associated symptoms and underlying pathophysiological mechanisms in children with ASD with d,l-leucovorin.

Biochimie, Jun 1, 2020

Autism spectrum disorders (ASD) are influenced by interacting maternal and environmental risk fac... more Autism spectrum disorders (ASD) are influenced by interacting maternal and environmental risk factors. High-dose folinic acid has shown improvement in verbal communication in ASD children. The EFFET randomized placebo-controlled trial (NCT02551380) aimed to evaluate the efficacy of folinic acid (FOLINORAL®) at a lower dose of 5 mg twice daily. Nineteen children were included in the EFFET trial. The primary efficacy outcome was improvement of Autism Diagnostic Observation Schedule (ADOS) score. The secondary outcomes were the improvement in ADOS sub scores communication, social interactions, Social Responsiveness Score (SRS) and treatment safety. The global ADOS score and social interaction and communication sub scores were significantly improved at week 12 compared to baseline in the folinic acid group (P = 0.003, P = 0.004 and P = 0.022, respectively), but not in the placebo group (P = 0.574, P = 0.780, P = 0.269, respectively). We observed a greater change of ADOS global score (-2.78 vs. -0.4 points) and (-1.78 vs. 0.20 points) in the folinic acid group, compared to the placebo group. No serious adverse events were observed. This pilot study showed significant efficacy of folinic acid with an oral formulation that is readily available. It opens a perspective of therapeutic intervention with folinic acid but needs to be confirmed by a multi-center trial on a larger number of children.

Clinical science and molecular medicine, 1975

Journal of Inherited Metabolic Disease, Dec 1, 1981

Studies of cobalamin metabolism in case of juvenile pernicious anaemia during haematological remi... more Studies of cobalamin metabolism in case of juvenile pernicious anaemia during haematological remission showed that while plasma cobalamins were normal there was some depletion of erythrocyte cobalamins. In addition, the plasma distribution of apo‐ and holo‐transcobalamins was markedly abnormal, holo‐TCII being increased, yet the patient's plasma promoted less cellular synthesis of adenosylcobalamin by cultured lymphocytes than did plasma from a control subject. The results suggest that holo‐TCII may in this case have been ineffective and provide further evidence for the importance of TCII in intracellular synthesis of adenosylcobalamin.

Archives of Biochemistry and Biophysics, 1994

Molecular Genetics and Metabolism, May 1, 2018

Introduction: Cerebral folate deficiency (CFD) syndromes are defined as neuro-psychiatric conditi... more Introduction: Cerebral folate deficiency (CFD) syndromes are defined as neuro-psychiatric conditions with low CSF folate and attributed to different causes such as autoantibodies against the folate receptor-alpha (FR) protein that can block folate transport across the choroid plexus, FOLR1 gene mutations or mitochondrial disorders. High-dose folinic acid treatment restores many neurologic deficits. Study aims and methods: Among 36 patients from 33 families the infantile-onset CFD syndrome was diagnosed based on typical clinical features and low CSF folate. All parents were healthy. Three families had 2 affected siblings, while parents from 4 families were first cousins. We analysed serum FR autoantibodies and the FOLR1 and FOLR2 genes. Among three consanguineous families homozygosity mapping attempted to identify a monogenetic cause. Whole exome sequencing (WES) was performed in the fourth consanguineous family, where two siblings also suffered from polyneuropathy as an atypical finding. Results: Boys (72%) outnumbered girls (28%). Most patients (89%) had serum FR autoantibodies fluctuating over 5-6 weeks. Two children had a genetic FOLR1 variant without pathological significance. Homozygosity mapping failed to detect a single autosomal recessive gene. WES revealed an autosomal recessive polynucleotide kinase 3´phosphatase (PNKP) gene abnormality in the siblings with polyneuropathy. Discussion: Infantile-onset CFD was characterized by serum FR autoantibodies as its predominant pathology whereas pathogenic FOLR1 gene mutations were absent. Homozygosity mapping excluded autosomal recessive inheritance of any single responsible gene. WES in one consanguineous family identified a PNKP gene abnormality that explained the polyneuropathy and also its contribution to the infantile CFD syndrome because the PNKP gene plays a dual role in both neurodevelopment and immune-regulatory function. Further research for candidate genes predisposing to FRα-autoimmunity is suggested to include X-chromosomal and non-coding DNA regions.

Obstetrical & Gynecological Survey, Jun 1, 2004

In the absence of clinical folate deficiency, periconceptional supplementation with folic acid re... more In the absence of clinical folate deficiency, periconceptional supplementation with folic acid reduces a woman's risk of having an infant with a neural-tube defect. Since antiserum to folate receptors induces embryo resorption and malformations in rats, we hypothesized that autoantibodies against folate receptors in women may be associated with pregnancy complicated by a neural-tube defect. methods Serum from 12 women who were or had been pregnant with a fetus with a neuraltube defect and from 24 control women (20 with current or prior normal pregnancies and 4 who were nulligravid) was analyzed for autoantibodies by incubation with human placental folate receptors radiolabeled with [ 3 H]folic acid. The properties of these autoantibodies were characterized by incubating serum and the autoantibodies isolated from serum with placental membranes, ED27 cells, and KB cells, which express the folate receptors. results Serum from 9 of 12 women with a current or previous affected pregnancy (index subjects) and 2 of 20 control subjects contained autoantibodies against folate receptors (P<0.001). The autoantibodies blocked the binding of [ 3 H]folic acid to folate receptors on placental membranes and on ED27 and KB cells incubated at 4°C and blocked the uptake of [ 3 H]folic acid by KB cells when incubated at 37°C. conclusions Serum from women with a pregnancy complicated by a neural-tube defect contains autoantibodies that bind to folate receptors and can block the cellular uptake of folate. Further study is warranted to assess whether the observed association between maternal autoantibodies against folate receptors and neural-tube defects reflects a causal relation.

Autism Research and Treatment, Nov 18, 2020

Background. Biomarkers such as oxidative stress, folate receptor alpha (FRα) autoimmunity, and ab... more Background. Biomarkers such as oxidative stress, folate receptor alpha (FRα) autoimmunity, and abnormal brain serotonin turnover are common in autism. Methods. Oxidative stress biomarkers with pro-and antioxidants were measured in the severe form of infantile autism (n � 38) and controls (n � 24). Children and parents had repeated testing for serum FR autoantibodies, spinal fluid dopamine and serotonin metabolites, pterins, and N 5-methyltetrahydrofolate (MTHF). Statistical analysis assessed correlations between variables. Genetic analysis included the SLC6A4 and SLC29A4 genes encoding synaptic serotonin reuptake proteins. Results. Compared to controls, the autism group showed a significant increase in oxidative DNA damage in lymphocytes, plasma ceruloplasmin and copper levels with a high copper/zinc ratio, thiol proteins, and superoxide dismutase (SOD) activity. Vitamin C levels were significantly diminished. In most autistic patients, the vitamin A (64%) and D (70%) levels were low. Serum FR autoantibodies fluctuating over 5-7 week periods presented in 68% of all autistic children, 41% of parents vs. 3.3% of control children and their parents. CSF showed lowered serotonin 5-hydroxyindole acetic acid (5HIAA) metabolites in 13 (34%), a low 5HIAA to HVA (dopamine metabolite) ratio in 5 (13%), low 5HIAA and MTHF in 2 (5%), and low MTHF in 8 patients (21%). A known SLC6A4 mutation was identified only in 1 autistic child with low CSF 5HIAA and a novel SLC29A4 mutation was identified in identical twins. Low CSF MTHF levels among only 26% of subjects can be explained by the fluctuating FR antibody titers. Two or more aberrant pro-oxidant and/or antioxidant factors predisposed to low CSF serotonin metabolites. ree autistic children having low CSF 5HIAA and elevated oxidative stress received antioxidative supplements followed by CSF 5HIAA normalisation. Conclusion. In autism, we found diverse combinations for FR autoimmunity and/or oxidative stress, both amenable to treatment. Parental and postnatal FR autoantibodies tend to block folate passage to the brain affecting folatedependent pathways restored by folinic acid treatment, while an abnormal redox status tends to induce reduced serotonin turnover, corrected by antioxidant therapy. Trial Registration. e case-controlled study was approved in 2008 by the IRB at Liège University (Belgian Number: B70720083916). Lay Summary. Children with severe infantile autism frequently have serum folate receptor autoantibodies that block the transport of the essential vitamin folate across the blood-brain barrier to the brain. Parents are often asymptomatic carriers of these serum folate receptor autoantibodies, which in mothers can block folate passage across the placenta to their unborn child. is folate deficiency during the child's intrauterine development may predispose to neural tube defects and autism. Oxidative stress represents a condition with the presence of elevated toxic oxygen derivatives attributed to an imbalance between the formation and protection against these toxic reactive oxygen derivatives. Oxidative stress was found to be present in autistic children where these reactive oxygen derivatives can cause damage to DNA, which changes DNA function and regulation of gene expression. In addition, excessive amounts of these toxic oxygen derivatives are likely to damage the enzyme producing the neuromessenger serotonin in the brain, diminished in about 1/3 of the autistic children. Testing children with autism for oxidative stress and its origin, as well as testing for serum folate receptor autoantibodies, could open new approaches towards more effective treatments.

The FASEB Journal, Apr 19, 2013

The membrane receptor TCblR/CD320 binds transcobalamin (TC) saturated with vitamin B12 [cobalamin... more The membrane receptor TCblR/CD320 binds transcobalamin (TC) saturated with vitamin B12 [cobalamin (Cbl)] and mediates cellular uptake of the vitamin. The specificity of TC for Cbl and of the receptor for TC-Cbl ensures efficient uptake of Cbl into cells. The high-affinity interaction of TCblR with TC-Cbl (Ka=10 nM−1) was investigated using deletions and mutations of amino acid sequences in TCblR. Only the extracellular region (aa 32–229) is needed for TC-Cbl binding, but the N-glycosylation sites (N126, N195, and N213) are of no importance for this function. Deleting the cysteine-rich region (aa 95–141) that separates the two low-density lipoprotein receptor type A (LDLR-A) domains does not affect TC-Cbl binding (Ka = 19–24 nM−1). The two LDLR-A domains (aa 54–89 and 132–167) with the negatively charged acidic residues involved in Ca2+ binding are critical determinants of ligand binding. The cytoplasmic tail is apparently crucial for internalization of the ligand. Within this region, the RPLGLL motif and the PDZ binding motifs (QERL/KESL) appear to be involved in initiating and completing the process of ligand internalization. Mutations and deletions of these regions involved in binding and internalization of TC-Cbl are likely to produce the biochemical and clinical phenotype of Cbl deficiency.—Jiang, W., Nakayama, Y., Sequeira, J. M., Quadros, E. V. Mapping the functional domains of TCblR/CD320, the receptor for cellular uptake of transcobalamin-bound cobalamin.

Blood, Mar 1, 1993

Transcobalamin II (TCII) is a cobalamin (Cbl, vitamin B12)binding protein in mammalian plasma tha... more Transcobalamin II (TCII) is a cobalamin (Cbl, vitamin B12)binding protein in mammalian plasma that facilitates the cellular uptake of the vitamin. To obtain human TCll in sufficient quantity for analytical studies, the complementary DNA (cDNA) encoding TCll was inserted into the plasmid PVL 1393, and the baculovirus expressing TCll was obtained by homologous recombination in Spodoptera frugiperda (SF9) insect cells by cotransfection with the wildtype virus. Under optimized conditions, SF9 cells infected with the recombinant virus secreted 2 to 4 fig of TCll per milliliter of culture medium. TCll did not accumulate in the SF9 cells and seemed to be constitutively secreted as observed previously in cultured human endothelial cells. The purified recombinant TCll has the same molecular weight by SDS-PAGE as purified human TCII. The recombinant TCll crossreacts with an antiserum to native human TCII, binds Cbl and facilitates the uptake of Cbl in eukaryotic cells by bind-RANSCOBALAMIN I1 (TCII) is a cobalamin (Cbl, vi

Biochimie, Jul 1, 2016

Multiple factors such as genetic and extraneous causes (drugs, toxins, adverse psychological even... more Multiple factors such as genetic and extraneous causes (drugs, toxins, adverse psychological events) contribute to neuro-psychiatric conditions. In a subgroup of these disorders, systemic folate deficiency has been associated with macrocytic anemia and neuropsychiatric phenotypes. In some of these, despite normal systemic levels, folate transport to the brain is impaired in the so-called cerebral folate deficiency (CFD) syndromes presenting as developmental and psychiatric disorders. These include infantile-onset CFD syndrome, infantile autism with or without neurologic deficits, a spastic-ataxic syndrome and intractable epilepsy in young children expanding to refractory schizophrenia in adolescents, and finally treatment-resistant major depression in adults. Folate receptor alpha (FRα) autoimmunity with low CSF N 5-methyl-tetrahydrofolate (MTHF) underlies most CFD syndromes, whereas FRα gene abnormalities and mitochondrial gene defects are rarely found. The age at which FRα antibodies of the blocking type emerge, determines the clinical phenotype. Infantile CFD syndrome and autism with neurological deficits tend to be characterized by elevated FRα antibody titers and low CSF MTHF. In contrast, in infantile autism and intractable schizophrenia, abnormal behavioral signs and symptoms may wax and wane with fluctuating FRα antibody titers over time accompanied by cycling changes in CSF folate, tetrahydrobiopterin (BH4) and neurotransmitter metabolites ranging between low and normal levels. We propose a hypothetical model explaining the pathogenesis of schizophrenia. Based on findings from clinical, genetic, spinal fluid and MRI spectroscopic studies, we discuss the neurochemical changes associated with these disorders, metabolic and regulatory pathways, synthesis and catabolism of neurotransmitters, and the impact of oxidative stress on the pathogenesis of these conditions. A diagnostic algorithm and therapeutic regimens using high dose folinic acid, corticosteroids and milk-free diet is presented which has proven to be beneficial in providing adequate folate to the brain and decreasing the FRα autoantibody titer in those positive for the antibody.

Biochimie, Jul 1, 2016

Folates are essential in the intermediary metabolism of amino acids, synthesis of nucleotides and... more Folates are essential in the intermediary metabolism of amino acids, synthesis of nucleotides and for maintaining methylation reactions. They are also linked to the production of neurotransmitters through GTP needed for the synthesis of tetrahydrobiopterin. During pregnancy, folate is needed for fetal development. Folate deficiency during this period has been linked to increased risk of neural tube defects. Disturbances of folate metabolism due to genetic abnormalities or the presence of autoantibodies to folate receptor alpha (FRα) can impair physiologic processes dependent on folate, resulting in a variety of developmental disorders including cerebral folate deficiency syndrome and autism spectrum disorders. Overall, adequate folate status has proven to be important during pregnancy as well as neurological development and functioning in neonates and children. Treatment with pharmacologic doses of folinic acid has led to reversal of some symptoms in many children diagnosed with cerebral folate deficiency syndrome and autism, especially in those positive for autoantibodies to FRα. Thus, as the brain continues to develop throughout fetal and infant life, it can be affected and become dysfunctional due to a defective folate transport contributing to folate deficiency. Treatment and prevention of these disorders can be achieved by identification of those at risk and supplementation with folinic acid.

Obstetrical & Gynecological Survey, Nov 1, 2009

Background A previous report described the presence of autoantibodies against folate receptors in... more Background A previous report described the presence of autoantibodies against folate receptors in 75% of serum samples from women with a history of pregnancy complicated by a neural-tube defect, as compared with 10% of controls. We sought to confirm this finding in an Irish population, which traditionally has had a high prevalence of neuraltube defects. Methods We performed two studies. Study 1 consisted of analysis of stored frozen blood samples collected from 1993 through 1994 from 103 mothers with a history of pregnancy complicated by a neural-tube defect (case mothers), 103 mothers with a history of pregnancy but no complication by a neural-tube defect (matched with regard to number of pregnancies and sampling dates), 58 women who had never been pregnant, and 36 men. Study 2, conducted to confirm that the storage of samples did not influence the folate-receptor autoantibodies, included fresh samples from 37 case mothers, 22 control mothers, 10 women who had never been pregnant, and 9 men. All samples were assayed for blocking and binding autoantibodies against folate receptors. Results In Study 1, blocking autoantibodies were found in 17% of case mothers, as compared with 13% of control mothers (odds ratio, 1.54; 95% confidence interval [CI], 0.70 to 3.39), and binding autoantibodies in 29%, as compared with 32%, respectively (odds ratio, 0.82; 95% CI, 0.44 to 1.50). Study 2 showed similar results, indicating that sample degradation was unlikely. Conclusions The presence and titer of maternal folate-receptor autoantibodies were not significantly associated with a neural-tube defect-affected pregnancy in this Irish population.

Molecular Psychiatry, Oct 18, 2016

We sought to determine whether high-dose folinic acid improves verbal communication in children w... more We sought to determine whether high-dose folinic acid improves verbal communication in children with non-syndromic autism spectrum disorder (ASD) and language impairment in a double-blind placebo control setting. Forty-eight children (mean age 7 years 4 months; 82% male) with ASD and language impairment were randomized to receive 12 weeks of high-dose folinic acid (2 mg kg − 1 per day, maximum 50 mg per day; n = 23) or placebo (n = 25). Children were subtyped by glutathione and folate receptor-α autoantibody (FRAA) status. Improvement in verbal communication, as measured by a ability-appropriate standardized instrument, was significantly greater in participants receiving folinic acid as compared with those receiving placebo, resulting in an effect of 5.7 (1.0,10.4) standardized points with a medium-to-large effect size (Cohen's d = 0.70). FRAA status was predictive of response to treatment. For FRAA-positive participants, improvement in verbal communication was significantly greater in those receiving folinic acid as compared with those receiving placebo, resulting in an effect of 7.3 (1.4,13.2) standardized points with a large effect size (Cohen's d = 0.91), indicating that folinic acid treatment may be more efficacious in children with ASD who are FRAA positive. Improvements in subscales of the Vineland Adaptive Behavior Scale, the Aberrant Behavior Checklist, the Autism Symptom Questionnaire and the Behavioral Assessment System for Children were significantly greater in the folinic acid group as compared with the placebo group. There was no significant difference in adverse effects between treatment groups. Thus, in this small trial of children with non-syndromic ASD and language impairment, treatment with high-dose folinic acid for 12 weeks resulted in improvement in verbal communication as compared with placebo, particularly in those participants who were positive for FRAAs.

bioRxiv (Cold Spring Harbor Laboratory), Aug 16, 2021

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial ... more This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.

bioRxiv (Cold Spring Harbor Laboratory), Jan 12, 2022

FTY720 (fingolimod) is a sphingosine 1-phosphate (S1P) receptor modulator and sphingosine analogu... more FTY720 (fingolimod) is a sphingosine 1-phosphate (S1P) receptor modulator and sphingosine analogue approved for multiple sclerosis (MS) therapy, which can functionally antagonize the S1P receptor, S1P1. Vitamin B12 (B12) deficiency produces neurological manifestations resembling MS. Here, we report a new mechanism where FTY720 suppresses neuroinflammation by regulating B12 metabolic pathways. Nuclear RNA-seq of c-Fos-activated astrocytes (called ieAstrocytes) from experimental autoimmune encephalomyelitis (EAE) spinal cords identified up-regulation of CD320, a transcobalamin 2 (TCN2)-B12 receptor, by S1P1 inhibition. CD320 was reduced in MS plaques. Deficiency of CD320 or dietary B12 worsened EAE and eliminated FTY720's efficacy, while concomitantly down-regulating type I interferon signaling. TCN2 functioned as a chaperone for FTY720 and sphingosine, which induced astrocytic CD320 internalization. An accompanying paper identified a requirement for astrocyte sphingosine kinases in FTY720 efficacy and its altered expression in MS brains, molecularly linking MS and B12 deficiency that can be accessed by sphingolipid/fingolimod metabolic pathways.

Research Square (Research Square), Jun 16, 2023

Folate de ciency can lead to a myriad of disruptions in neurodevelopment including neural tube de... more Folate de ciency can lead to a myriad of disruptions in neurodevelopment including neural tube defects, developmental anomalies, and functional de cits, such as autism spectrum disorder (ASD). Folate receptor alpha (FRα) is the primary transporter of folate from the mother to the fetus and into the brain. A major subset of the ASD patients and their family members have autoantibodies against FRα that can block folate transport. Therefore, we investigated the effect of exposure to folate receptor alpha antibodies during fetal development, on behavioral de cits in the offspring in a rat model and determined if their de cits are passed on to a subsequent generation; thus, contributing to inheritance of the behavioral phenotype. We have produced a rat folate receptor alpha speci c antibody (FRαAb) that when injected intraperitoneally into a dam on gestation day (GD)8, produces a litter with behavioral de cits in social communication, social interaction, including learning, memory, and cognition. Using this model, we tested the litter directly exposed to FRαAb and bred the offspring that had an affected phenotype to produce a litter that was not directly exposed to FRαAb. We observed social communication de cits and de cits in learning performance in both generations which provides preliminary evidence to indicate transmission of a behavioral phenotype associated with the FRαAb exposure to the next generation. This work supports the growing evidence that an altered maternal immune and/or micronutrient environment has a generational effect on ASD offspring, likely transmitted by non-Mendelian inheritance.

Seminars in Pediatric Neurology, Oct 1, 2020

Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder that currently has ... more Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder that currently has no approved medical therapy to address core symptoms or underling pathophysiological processes. Several compounds are under development that address both underlying pathophysiological abnormalities and core ASD symptoms. This article reviews one of these treatments, d,l-leucovorin calcium (also known as folinic acid) for treatment of folate pathway abnormalities in children with ASD. Folate is a water-soluble B vitamin that is essential for normal neurodevelopment and abnormalities in the folate and related pathways have been identified in children with ASD. One of these abnormalities involves a partial blockage in the ability of folate to be transported into the brain utilizing the primary transport mechanism, the folate receptor alpha. Autoantibodies which interfere with the function of the folate receptor alpha called folate receptor alpha autoantibodies have been identified in 58%-76% of children with ASD and independent studies have demonstrated that blood titers of these autoantibodies correlate with folate levels in the cerebrospinal fluid. Most significantly, case-series, open-label, and single and double-blind placebo-controlled studies suggest that d,l-leucovorin, a reduced folate that can bypass the blockage at the folate receptor alpha by using the reduced folate carrier, an alternate pathway, can substantially improve particular symptoms in children with ASD, especially those positive for folate receptor alpha autoantibodies. This article reviews the current evidence for treating core and associated symptoms and underlying pathophysiological mechanisms in children with ASD with d,l-leucovorin.

Biochimie, Jun 1, 2020

Autism spectrum disorders (ASD) are influenced by interacting maternal and environmental risk fac... more Autism spectrum disorders (ASD) are influenced by interacting maternal and environmental risk factors. High-dose folinic acid has shown improvement in verbal communication in ASD children. The EFFET randomized placebo-controlled trial (NCT02551380) aimed to evaluate the efficacy of folinic acid (FOLINORAL®) at a lower dose of 5 mg twice daily. Nineteen children were included in the EFFET trial. The primary efficacy outcome was improvement of Autism Diagnostic Observation Schedule (ADOS) score. The secondary outcomes were the improvement in ADOS sub scores communication, social interactions, Social Responsiveness Score (SRS) and treatment safety. The global ADOS score and social interaction and communication sub scores were significantly improved at week 12 compared to baseline in the folinic acid group (P = 0.003, P = 0.004 and P = 0.022, respectively), but not in the placebo group (P = 0.574, P = 0.780, P = 0.269, respectively). We observed a greater change of ADOS global score (-2.78 vs. -0.4 points) and (-1.78 vs. 0.20 points) in the folinic acid group, compared to the placebo group. No serious adverse events were observed. This pilot study showed significant efficacy of folinic acid with an oral formulation that is readily available. It opens a perspective of therapeutic intervention with folinic acid but needs to be confirmed by a multi-center trial on a larger number of children.

Clinical science and molecular medicine, 1975

Journal of Inherited Metabolic Disease, Dec 1, 1981

Studies of cobalamin metabolism in case of juvenile pernicious anaemia during haematological remi... more Studies of cobalamin metabolism in case of juvenile pernicious anaemia during haematological remission showed that while plasma cobalamins were normal there was some depletion of erythrocyte cobalamins. In addition, the plasma distribution of apo‐ and holo‐transcobalamins was markedly abnormal, holo‐TCII being increased, yet the patient's plasma promoted less cellular synthesis of adenosylcobalamin by cultured lymphocytes than did plasma from a control subject. The results suggest that holo‐TCII may in this case have been ineffective and provide further evidence for the importance of TCII in intracellular synthesis of adenosylcobalamin.

Archives of Biochemistry and Biophysics, 1994

Molecular Genetics and Metabolism, May 1, 2018

Introduction: Cerebral folate deficiency (CFD) syndromes are defined as neuro-psychiatric conditi... more Introduction: Cerebral folate deficiency (CFD) syndromes are defined as neuro-psychiatric conditions with low CSF folate and attributed to different causes such as autoantibodies against the folate receptor-alpha (FR) protein that can block folate transport across the choroid plexus, FOLR1 gene mutations or mitochondrial disorders. High-dose folinic acid treatment restores many neurologic deficits. Study aims and methods: Among 36 patients from 33 families the infantile-onset CFD syndrome was diagnosed based on typical clinical features and low CSF folate. All parents were healthy. Three families had 2 affected siblings, while parents from 4 families were first cousins. We analysed serum FR autoantibodies and the FOLR1 and FOLR2 genes. Among three consanguineous families homozygosity mapping attempted to identify a monogenetic cause. Whole exome sequencing (WES) was performed in the fourth consanguineous family, where two siblings also suffered from polyneuropathy as an atypical finding. Results: Boys (72%) outnumbered girls (28%). Most patients (89%) had serum FR autoantibodies fluctuating over 5-6 weeks. Two children had a genetic FOLR1 variant without pathological significance. Homozygosity mapping failed to detect a single autosomal recessive gene. WES revealed an autosomal recessive polynucleotide kinase 3´phosphatase (PNKP) gene abnormality in the siblings with polyneuropathy. Discussion: Infantile-onset CFD was characterized by serum FR autoantibodies as its predominant pathology whereas pathogenic FOLR1 gene mutations were absent. Homozygosity mapping excluded autosomal recessive inheritance of any single responsible gene. WES in one consanguineous family identified a PNKP gene abnormality that explained the polyneuropathy and also its contribution to the infantile CFD syndrome because the PNKP gene plays a dual role in both neurodevelopment and immune-regulatory function. Further research for candidate genes predisposing to FRα-autoimmunity is suggested to include X-chromosomal and non-coding DNA regions.

Obstetrical & Gynecological Survey, Jun 1, 2004

In the absence of clinical folate deficiency, periconceptional supplementation with folic acid re... more In the absence of clinical folate deficiency, periconceptional supplementation with folic acid reduces a woman's risk of having an infant with a neural-tube defect. Since antiserum to folate receptors induces embryo resorption and malformations in rats, we hypothesized that autoantibodies against folate receptors in women may be associated with pregnancy complicated by a neural-tube defect. methods Serum from 12 women who were or had been pregnant with a fetus with a neuraltube defect and from 24 control women (20 with current or prior normal pregnancies and 4 who were nulligravid) was analyzed for autoantibodies by incubation with human placental folate receptors radiolabeled with [ 3 H]folic acid. The properties of these autoantibodies were characterized by incubating serum and the autoantibodies isolated from serum with placental membranes, ED27 cells, and KB cells, which express the folate receptors. results Serum from 9 of 12 women with a current or previous affected pregnancy (index subjects) and 2 of 20 control subjects contained autoantibodies against folate receptors (P<0.001). The autoantibodies blocked the binding of [ 3 H]folic acid to folate receptors on placental membranes and on ED27 and KB cells incubated at 4°C and blocked the uptake of [ 3 H]folic acid by KB cells when incubated at 37°C. conclusions Serum from women with a pregnancy complicated by a neural-tube defect contains autoantibodies that bind to folate receptors and can block the cellular uptake of folate. Further study is warranted to assess whether the observed association between maternal autoantibodies against folate receptors and neural-tube defects reflects a causal relation.

Autism Research and Treatment, Nov 18, 2020

Background. Biomarkers such as oxidative stress, folate receptor alpha (FRα) autoimmunity, and ab... more Background. Biomarkers such as oxidative stress, folate receptor alpha (FRα) autoimmunity, and abnormal brain serotonin turnover are common in autism. Methods. Oxidative stress biomarkers with pro-and antioxidants were measured in the severe form of infantile autism (n � 38) and controls (n � 24). Children and parents had repeated testing for serum FR autoantibodies, spinal fluid dopamine and serotonin metabolites, pterins, and N 5-methyltetrahydrofolate (MTHF). Statistical analysis assessed correlations between variables. Genetic analysis included the SLC6A4 and SLC29A4 genes encoding synaptic serotonin reuptake proteins. Results. Compared to controls, the autism group showed a significant increase in oxidative DNA damage in lymphocytes, plasma ceruloplasmin and copper levels with a high copper/zinc ratio, thiol proteins, and superoxide dismutase (SOD) activity. Vitamin C levels were significantly diminished. In most autistic patients, the vitamin A (64%) and D (70%) levels were low. Serum FR autoantibodies fluctuating over 5-7 week periods presented in 68% of all autistic children, 41% of parents vs. 3.3% of control children and their parents. CSF showed lowered serotonin 5-hydroxyindole acetic acid (5HIAA) metabolites in 13 (34%), a low 5HIAA to HVA (dopamine metabolite) ratio in 5 (13%), low 5HIAA and MTHF in 2 (5%), and low MTHF in 8 patients (21%). A known SLC6A4 mutation was identified only in 1 autistic child with low CSF 5HIAA and a novel SLC29A4 mutation was identified in identical twins. Low CSF MTHF levels among only 26% of subjects can be explained by the fluctuating FR antibody titers. Two or more aberrant pro-oxidant and/or antioxidant factors predisposed to low CSF serotonin metabolites. ree autistic children having low CSF 5HIAA and elevated oxidative stress received antioxidative supplements followed by CSF 5HIAA normalisation. Conclusion. In autism, we found diverse combinations for FR autoimmunity and/or oxidative stress, both amenable to treatment. Parental and postnatal FR autoantibodies tend to block folate passage to the brain affecting folatedependent pathways restored by folinic acid treatment, while an abnormal redox status tends to induce reduced serotonin turnover, corrected by antioxidant therapy. Trial Registration. e case-controlled study was approved in 2008 by the IRB at Liège University (Belgian Number: B70720083916). Lay Summary. Children with severe infantile autism frequently have serum folate receptor autoantibodies that block the transport of the essential vitamin folate across the blood-brain barrier to the brain. Parents are often asymptomatic carriers of these serum folate receptor autoantibodies, which in mothers can block folate passage across the placenta to their unborn child. is folate deficiency during the child's intrauterine development may predispose to neural tube defects and autism. Oxidative stress represents a condition with the presence of elevated toxic oxygen derivatives attributed to an imbalance between the formation and protection against these toxic reactive oxygen derivatives. Oxidative stress was found to be present in autistic children where these reactive oxygen derivatives can cause damage to DNA, which changes DNA function and regulation of gene expression. In addition, excessive amounts of these toxic oxygen derivatives are likely to damage the enzyme producing the neuromessenger serotonin in the brain, diminished in about 1/3 of the autistic children. Testing children with autism for oxidative stress and its origin, as well as testing for serum folate receptor autoantibodies, could open new approaches towards more effective treatments.

The FASEB Journal, Apr 19, 2013

The membrane receptor TCblR/CD320 binds transcobalamin (TC) saturated with vitamin B12 [cobalamin... more The membrane receptor TCblR/CD320 binds transcobalamin (TC) saturated with vitamin B12 [cobalamin (Cbl)] and mediates cellular uptake of the vitamin. The specificity of TC for Cbl and of the receptor for TC-Cbl ensures efficient uptake of Cbl into cells. The high-affinity interaction of TCblR with TC-Cbl (Ka=10 nM−1) was investigated using deletions and mutations of amino acid sequences in TCblR. Only the extracellular region (aa 32–229) is needed for TC-Cbl binding, but the N-glycosylation sites (N126, N195, and N213) are of no importance for this function. Deleting the cysteine-rich region (aa 95–141) that separates the two low-density lipoprotein receptor type A (LDLR-A) domains does not affect TC-Cbl binding (Ka = 19–24 nM−1). The two LDLR-A domains (aa 54–89 and 132–167) with the negatively charged acidic residues involved in Ca2+ binding are critical determinants of ligand binding. The cytoplasmic tail is apparently crucial for internalization of the ligand. Within this region, the RPLGLL motif and the PDZ binding motifs (QERL/KESL) appear to be involved in initiating and completing the process of ligand internalization. Mutations and deletions of these regions involved in binding and internalization of TC-Cbl are likely to produce the biochemical and clinical phenotype of Cbl deficiency.—Jiang, W., Nakayama, Y., Sequeira, J. M., Quadros, E. V. Mapping the functional domains of TCblR/CD320, the receptor for cellular uptake of transcobalamin-bound cobalamin.

Blood, Mar 1, 1993

Transcobalamin II (TCII) is a cobalamin (Cbl, vitamin B12)binding protein in mammalian plasma tha... more Transcobalamin II (TCII) is a cobalamin (Cbl, vitamin B12)binding protein in mammalian plasma that facilitates the cellular uptake of the vitamin. To obtain human TCll in sufficient quantity for analytical studies, the complementary DNA (cDNA) encoding TCll was inserted into the plasmid PVL 1393, and the baculovirus expressing TCll was obtained by homologous recombination in Spodoptera frugiperda (SF9) insect cells by cotransfection with the wildtype virus. Under optimized conditions, SF9 cells infected with the recombinant virus secreted 2 to 4 fig of TCll per milliliter of culture medium. TCll did not accumulate in the SF9 cells and seemed to be constitutively secreted as observed previously in cultured human endothelial cells. The purified recombinant TCll has the same molecular weight by SDS-PAGE as purified human TCII. The recombinant TCll crossreacts with an antiserum to native human TCII, binds Cbl and facilitates the uptake of Cbl in eukaryotic cells by bind-RANSCOBALAMIN I1 (TCII) is a cobalamin (Cbl, vi

Biochimie, Jul 1, 2016

Multiple factors such as genetic and extraneous causes (drugs, toxins, adverse psychological even... more Multiple factors such as genetic and extraneous causes (drugs, toxins, adverse psychological events) contribute to neuro-psychiatric conditions. In a subgroup of these disorders, systemic folate deficiency has been associated with macrocytic anemia and neuropsychiatric phenotypes. In some of these, despite normal systemic levels, folate transport to the brain is impaired in the so-called cerebral folate deficiency (CFD) syndromes presenting as developmental and psychiatric disorders. These include infantile-onset CFD syndrome, infantile autism with or without neurologic deficits, a spastic-ataxic syndrome and intractable epilepsy in young children expanding to refractory schizophrenia in adolescents, and finally treatment-resistant major depression in adults. Folate receptor alpha (FRα) autoimmunity with low CSF N 5-methyl-tetrahydrofolate (MTHF) underlies most CFD syndromes, whereas FRα gene abnormalities and mitochondrial gene defects are rarely found. The age at which FRα antibodies of the blocking type emerge, determines the clinical phenotype. Infantile CFD syndrome and autism with neurological deficits tend to be characterized by elevated FRα antibody titers and low CSF MTHF. In contrast, in infantile autism and intractable schizophrenia, abnormal behavioral signs and symptoms may wax and wane with fluctuating FRα antibody titers over time accompanied by cycling changes in CSF folate, tetrahydrobiopterin (BH4) and neurotransmitter metabolites ranging between low and normal levels. We propose a hypothetical model explaining the pathogenesis of schizophrenia. Based on findings from clinical, genetic, spinal fluid and MRI spectroscopic studies, we discuss the neurochemical changes associated with these disorders, metabolic and regulatory pathways, synthesis and catabolism of neurotransmitters, and the impact of oxidative stress on the pathogenesis of these conditions. A diagnostic algorithm and therapeutic regimens using high dose folinic acid, corticosteroids and milk-free diet is presented which has proven to be beneficial in providing adequate folate to the brain and decreasing the FRα autoantibody titer in those positive for the antibody.

Biochimie, Jul 1, 2016

Folates are essential in the intermediary metabolism of amino acids, synthesis of nucleotides and... more Folates are essential in the intermediary metabolism of amino acids, synthesis of nucleotides and for maintaining methylation reactions. They are also linked to the production of neurotransmitters through GTP needed for the synthesis of tetrahydrobiopterin. During pregnancy, folate is needed for fetal development. Folate deficiency during this period has been linked to increased risk of neural tube defects. Disturbances of folate metabolism due to genetic abnormalities or the presence of autoantibodies to folate receptor alpha (FRα) can impair physiologic processes dependent on folate, resulting in a variety of developmental disorders including cerebral folate deficiency syndrome and autism spectrum disorders. Overall, adequate folate status has proven to be important during pregnancy as well as neurological development and functioning in neonates and children. Treatment with pharmacologic doses of folinic acid has led to reversal of some symptoms in many children diagnosed with cerebral folate deficiency syndrome and autism, especially in those positive for autoantibodies to FRα. Thus, as the brain continues to develop throughout fetal and infant life, it can be affected and become dysfunctional due to a defective folate transport contributing to folate deficiency. Treatment and prevention of these disorders can be achieved by identification of those at risk and supplementation with folinic acid.

Obstetrical & Gynecological Survey, Nov 1, 2009

Background A previous report described the presence of autoantibodies against folate receptors in... more Background A previous report described the presence of autoantibodies against folate receptors in 75% of serum samples from women with a history of pregnancy complicated by a neural-tube defect, as compared with 10% of controls. We sought to confirm this finding in an Irish population, which traditionally has had a high prevalence of neuraltube defects. Methods We performed two studies. Study 1 consisted of analysis of stored frozen blood samples collected from 1993 through 1994 from 103 mothers with a history of pregnancy complicated by a neural-tube defect (case mothers), 103 mothers with a history of pregnancy but no complication by a neural-tube defect (matched with regard to number of pregnancies and sampling dates), 58 women who had never been pregnant, and 36 men. Study 2, conducted to confirm that the storage of samples did not influence the folate-receptor autoantibodies, included fresh samples from 37 case mothers, 22 control mothers, 10 women who had never been pregnant, and 9 men. All samples were assayed for blocking and binding autoantibodies against folate receptors. Results In Study 1, blocking autoantibodies were found in 17% of case mothers, as compared with 13% of control mothers (odds ratio, 1.54; 95% confidence interval [CI], 0.70 to 3.39), and binding autoantibodies in 29%, as compared with 32%, respectively (odds ratio, 0.82; 95% CI, 0.44 to 1.50). Study 2 showed similar results, indicating that sample degradation was unlikely. Conclusions The presence and titer of maternal folate-receptor autoantibodies were not significantly associated with a neural-tube defect-affected pregnancy in this Irish population.