Cerebral Folate Transport Deficiency in 2 Cases with Intractable Myoclonic Epilepsy.

Cerebral folate transport deficiency due to folate receptor 1 gene (FOLR1) gene mutation results from impaired folate transport across the blood: choroidplexus: cerebrospinal fluid (CSF) barrier. This leads to low CSF 5-methyltetrahydrofolate, the active folate metabolite. We are reporting two children with this treatable cerebral folate transport deficiency. Eight years and 9-month-old female presented with delayed milestones followed by regression, seizures, and intention tremors. On examination child had microcephaly, generalized hypotonia, hyperreflexia, unsteady gait, and incoordination. Magnetic resonance imaging (MRI) of brain revealed dilated ventricular system and cerebellar atrophy. Computed tomography (CT) of brain showed brain calcifications. Whole exome sequencing was finally performed, revealing homozygous nonsense pathogenic variant in FOLR1 gene in exon 3 c.C382T p.R128W, confirming the diagnosis of cerebral folate deficiency. Twelve-year-old female child presented with global developmental delay since birth, myoclonic jerks and cognitive regression. Child had generalized hypotonia and hyperreflexia. Her coordination was markedly affected with intention tremors andunbalanced gait. CT brain showed bilateral basal ganglia and periventricular calcifications with brain atrophic changes. MRI brain showed a prominent cerebellar folia with mild brain atrophic changes. Genetic testing showed a homozygous pathogenic variant was identified in FOLR1 C.327_328 delinsAC, p.Cys109Ter. Both patients were started on intramuscular folinic acid injections with a decrease in seizure frequency. However, their seizures did not stop completely due to late initiation of therapy. In conclusion, cerebral folate transport deficiency should be suspected in every child with global developmental delay, intractable myoclonic epilepsy, ataxia with neuroimaging suggesting cerebellar atrophy and brain calcifications. Response to folinic acid supplementation is partial if diagnosed late and treatment initiation is delayed.

Disturbed intracellular folate homeostasis impairs autophagic flux and increases hepatocytic lipid accumulation.

BACKGROUND: Metabolic associated fatty liver disease (MAFLD), a prevalent liver disorder affecting one-third of the global population, encompasses a spectrum ranging from fatty liver to severe hepatic steatosis. Both genetic and lifestyle factors, particularly diet and nutrition, contribute to its etiology. Folate deficiency, a frequently encountered type of malnutrition, has been associated with the pathogenesis of MAFLD and shown to impact lipid deposition. However, the underlying mechanisms of this relationship remain incompletely understood. We investigated the impact of disturbed folate-mediated one-carbon metabolism (OCM) on hepatic lipid metabolism both in vitro using human hepatoma cells and in vivo using transgenic fluorescent zebrafish displaying extent-, stage-, and duration-controllable folate deficiency upon induction. RESULTS: Disturbed folate-mediated one-carbon metabolism, either by inducing folate deficiency or adding anti-folate drug, compromises autophagy and causes lipid accumulation in liver cells. Disturbed folate status down-regulates cathepsin L, a key enzyme involved in autophagy, through inhibiting mTOR signaling. Interfered mitochondrial biology, including mitochondria relocation and increased fusion-fission dynamics, also occurs in folate-deficient hepatocytes. Folate supplementation effectively mitigated the impaired autophagy and lipid accumulation caused by the inhibition of cathepsin L activity, even when the inhibition was not directly related to folate deficiency. CONCLUSIONS: Disruption of folate-mediated OCM diminishes cathepsin L expression and impedes autophagy via mTOR signaling, leading to lipid accumulation within hepatocytes. These findings underscore the crucial role of folate in modulating autophagic processes and regulating lipid metabolism in the liver.

Environmental Signals.

Environmental factors have long been known to play a role in the pathogenesis of congenital heart disease (CHD), but this has not been a major focus of research in the modern era. Studies of human exposures and animal models demonstrate that demographics (age, race, socioeconomic status), diseases (e.g., diabetes, hypertension, obesity, stress, infection, high altitude), recreational and therapeutic drug use, and chemical exposures are associated with an increased risk for CHD. Unfortunately, although studies suggest that exposures to these factors may cause CHD, in most cases, the data are not strong, are inconclusive, or are contradictory. Although most studies concentrate on the effects of maternal exposure, paternal exposure to some agents can also modify this risk. From a mechanistic standpoint, recent delineation of signaling and genetic controls of cardiac development has revealed molecular pathways that may explain the effects of environmental signals on cardiac morphogenesis and may provide further tools to study the effects of environmental stimuli on cardiac development. For example, environmental factors likely regulate cellular signaling pathways, transcriptional and epigenetic regulation, proliferation, and physiologic processes that can control the development of the heart and other organs. However, understanding of the epidemiology and risk of these exposures and the mechanistic basis for any effects on cardiac development remains incomplete. Further studies defining the relationship between environmental exposures and human CHD and the mechanisms involved should reveal strategies to prevent, diagnose, and treat CHD induced by environmental signals.

Impact of varying maternal dietary folate intake on cerebellar cortex histomorphology and cell density in offspring rats.

The cerebellum has a long, protracted developmental period that spans from the embryonic to postnatal periods; as a result, it is more sensitive to intrauterine and postnatal insults like nutritional deficiencies. Folate is crucial for foetal and early postnatal brain development; however, its effects on cerebellar growth and development are unknown. The aim of this study was to examine the effects of maternal folate intake on the histomorphology and cell density of the developing cerebellum. Twelve adult female rats (rattus norvegicus) were randomly assigned to one of four premixed diet groups: standard (2 mg/kg), folate-deficient (0 mg/kg), folate-supplemented (8 mg/kg) or folate supra-supplemented (40 mg/kg). The rats started their diets 14 days before mating and consumed them throughout pregnancy and lactation. On postnatal days 1, 7, 21 and 35, five pups from each group were sacrificed, and their brains were processed for light microscopic analysis. Histomorphology and cell density of the external granule, molecular, Purkinje and internal granule layers were obtained. The folate-deficient diet group had smaller, dysmorphic cells and significantly lower densities of external granule, molecular, Purkinje and internal granule cells. Although the folate-enriched groups had greater cell densities than the controls, the folate-supplemented group had considerably higher cell densities than the supra-supplemented group. The folate supra-supplemented group had ectopic Purkinje cells in the internal granule cell layer. These findings imply that a folate-deficient diet impairs cellular growth and reduces cell density in the cerebellar cortex. On the other hand, folate supplementation increases cell densities, but there appears to be an optimal dose of supplementation since excessive folate levels may be detrimental.

Multiplexing of TMT labeling reveals folate-deficient diet-specific proteome changes in NTDs.

Introduction: In the early stage of embryonic development, the neural tube (NT) cannot be closed properly due to some complex factors, including environmental factors, genetic factors, and the relationship between various factors, leading to the occurrence of neural tube defects (NTDs). Methods: In this study, we induced a mouse model of NTDs by feeding mice with a low-folate diet and intraperitoneally injecting them with 1.5 mg/kg methotrexate on E7.5. Fetal mice were achieved at E13.5, and we extracted proteins from brain tissues with trypsin digestion. After enzymatic digestion, peptides were labeled with TMT/iTRAQ and separated in high-performance liquid chromatography (HPLC) for subsequent liquid chromatography tandem mass spectroscopy (LC-MS/MS) analysis. We used gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation to analyze proteomic changes and analyze the functional enrichment of differentially expressed proteins (DEPs) in the NTD mice tissues. Results: A low-folate-induced mouse model was successfully constructed. Folate was used as a sensitizing agent, and the teratogenicity rate of the NTD fetal mice increased to 36.5% when the concentration of methotrexate was at 1.5 mg/kg. Mass spectrometry was used to identify 6,614 proteins, and among them, 5,656 proteins were quantified. In the following proteomic analysis, GO classification and KEGG pathway enrichment analysis were conducted, and heatmaps were drawn for differentially expressed proteins (DEPs). The main pathways associated with NTDs, such as the Hedgehog, Wnt, p53, and Hippo signaling pathways and the one-carbon pool mediated by folate, can be identified through a protein-protein interaction (PPI) network. It was also found that the regulation of ribosomal proteins, such as RPL13 and RPL14, which are upregulated in NTDs, has a certain impact on neural tube development. Discussion: Our results revealed proteomic changes in the tissues of low-folate-induced NTD mice. Validation showed that ribosomal proteins play a regulatory role during the development of NTDs and provides new ideas for the pathogenesis and preventive measures of NTDs.

A Cross-Sectional Study for the Spectrum of Clinical Diagnosis in Patients Presenting With Macrocytosis.

Objective The objectives of this study were to determine the frequency of the clinical spectrum of diseases in patients with macrocytosis and to summarize the diagnostic evaluation of patients found to have macrocytosis on laboratory testing. Background This was a cross-sectional study that took place at the Department of Medicine in Combined Military Hospital, Rawalpindi, Pakistan, from January to June 2023. Methodology One hundred and five patients with macrocytosis with mean corpuscular volume (MCV) values > 100 fL (80 to 100 fL) were inducted as per inclusion and exclusion criteria. Informed consent was obtained from all patients. Complete blood counts (CBC), peripheral blood film, serum vitamin B12 levels, serum folate levels, renal function tests (RFTs), liver function tests (LFTs), and thyroid function tests (TFTs) were performed during the assessment. Results The commonest cause of macrocytosis was vitamin B12 deficiency followed by folate deficiency, combined vitamin B12 and folate deficiency, and other causes were also found in a few cases. Conclusion Serum vitamin B12 and folate deficiency are the most common preventable causes of macrocytosis.

The association of folate deficiency with clinical and radiological severity of knee osteoarthritis.

CONTEXT: Folate deficiency is often observed in patients with inflammatory diseases, raising questions about its role in knee osteoarthritis (OA) progression. OBJECTIVES: This study aimed to assess the association of folate deficiency with the clinical and radiological severity of knee OA. METHODS: A prospective cross-sectional study was conducted from January 1, 2019 to January 1, 2020. Primary knee OA patients referred to orthopedic clinics in Zabol, Iran were included. Radiographic severity was gauged utilizing the Kellgren-Lawrence (KL) classification. For clinical severity, patients completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. IBM SPSS v.27 facilitated the statistical analysis. RESULTS: Forty-nine knee OA patients, averaging 67.45±13.44 years in age, were analyzed. Spearman correlation analysis revealed a negative correlation between folate levels and both WOMAC and KL scores. The correlation was stronger between folate and KL score (Spearman correlation coefficient: -0.75) than between folate and WOMAC total score (Spearman correlation coefficient: -0.46). Additionally, a significantly higher KL score was observed in patients with folate deficiency (p=0.004). CONCLUSIONS: Our study highlights a significant correlation between folate deficiency and increased severity of OA, which is evident in radiological and clinical assessments. These findings suggest that folate plays a key role in OA pathogenesis and could be a modifiable factor in its management.

Maternal usage of varying levels of dietary folate affects the postnatal development of cerebellar folia and cortical layer volumes.

OBJECTIVE: The cerebellum has a long, protracted developmental period; therefore, it is more sensitive to intrauterine and postnatal insults like nutritional deficiencies. Folate is an essential nutrient in fetal and postnatal brain development, and its supplementation during pregnancy is widely recommended. This study aimed to describe the effects of maternal folate intake on postnatal cerebellum development. METHODS: Twelve adult female Rattus norwegicus (6-8 weeks old) rats were randomly assigned to one of four groups and given one of four premixed diets: a standard diet (2 mg/kg), a folate-deficient (folate 0 mg/kg), folate-supplemented (8 mg/kg), or folate supra-supplemented (40 mg/kg). The rats began consuming their specific diets 14 days before mating and were maintained on them throughout pregnancy and lactation. Five pups from each group were sacrificed, and their brains processed for light microscopic examination on postnatal days 1, 7, 21, and 35. The data gathered included the morphology of the cerebellar folia and an estimate of the volume of the cerebellar cortical layer using the Cavalieri method. RESULTS: Folia of the folate-supplemented and supra-supplemented groups were thicker and showed extensive branching with sub-lobule formation. The folate-deficient diet group's folia were smaller, had more inter-folial spaces, or fused. When compared to the folate-deficient group, the volumes of the cerebellum and individual cerebellar cortical layers were significantly larger in the folate-supplemented and supra-supplemented groups (p<0.05). CONCLUSION: Folate supplementation during pregnancy and lactation improves the degree and complexity of the cerebellar folia and the volumes of individual cerebellar cortical layers.

Folate receptor α deficiency - Myelin-sensitive MRI as a reliable biomarker to monitor the efficacy and long-term outcome of a new therapeutic approach.

Cerebral folate transport deficiency, caused by a genetic defect in folate receptor α, is a devastating neurometabolic disorder that, if untreated, leads to epileptic encephalopathy, psychomotor decline and hypomyelination. Currently, there are limited data on effective dosage and duration of treatment, though early diagnosis and therapy with folinic acid appears critical. The aim of this long-term study was to identify new therapeutic approaches and novel biomarkers for assessing efficacy, focusing on myelin-sensitive MRI. Clinical, biochemical, structural and quantitative MRI parameters of seven patients with genetically confirmed folate receptor α deficiency were acquired over 13 years. Multimodal MRI approaches comprised MR-spectroscopy (MRS), magnetization transfer (MTI) and diffusion tensor imaging (DTI) sequences. Patients started oral treatment immediately following diagnosis or in an interval of up to 2.5 years. Escalation to intravenous and intrathecal administration was performed in the absence of effects. Five patients improved, one with a presymptomatic start of therapy remained symptom-free, and one with inconsistent treatment deteriorated. While CSF 5-methyltetrahydrofolate and MRS parameters normalized immediately after therapy initiation, myelin-sensitive MTI and DTI measures correlated with gradual clinical improvement and ongoing myelination under therapy. Early initiation of treatment at sufficient doses, considering early intrathecal applications, is critical for favorable outcome. The majority of patients showed clinical improvements that correlated best with MTI parameters, allowing individualized monitoring of myelination recovery. Presymptomatic therapy seems to ensure normal development and warrants newborn screening. Furthermore, the quantitative parameters of myelin-sensitive MRI for therapy assessments can now be used for hypomyelination disorders in general.

Folate deficiency promotes cervical squamous carcinoma SiHa cells progression by targeting miR-375/FZD4/ß-catenin signaling.

Epidemiological studies suggest an association between folate deficiency (FD) and cervical squamous cell carcinoma (SCC) progression. However, the underlying mechanism is unclear. Our study showed that FD-driven downregulation of miR-375 promoted proliferation of SCC SiHa cells and progression of xenograft tumors developed from SiHa; however, the exact mechanism of this process remained unclear. The current study aimed to elucidate the underlying mechanisms by which FD promotes the progression of SiHa cells by downregulating miR-375 expression. The results showed that miR-375 acted as a suppressor of SCC and inhibited the proliferation, migration, and invasion of SiHa cells. The FZD4 gene was identified as a target gene of miR-375, which can reverse the anti-onco effect of miR-375 and promote the proliferation and migration of SiHa cells. Furthermore, the regulatory effects of miR-375 and FZD4 on SiHa cells may be achieved by activating the ß-catenin signaling pathway. Moreover, FD may regulate the expression of miR-375 by regulating its DNA methylation level in the promoter region. In conclusion, our study reveals that FD regulates the miR-375/FZD4 axis by increasing the methylation of the miR-375 promoter, thereby activating ß-catenin signaling to promote SiHa cells progression. This study may provide new insights into the role of folic acid in the prevention and treatment of SCC.

Prenatal folate deficiency impairs sociability and memory/recognition in mice offspring.

Folate is essential for the normal growth and development of the fetus. Folic acid supplementation during the fetal period affects postnatal brain development and reduces the incidence of mental disorders in animal and human studies. However, the association between folate deficiency (FD) during pregnancy and developmental disorders in children remains poorly understood. In this study, we investigated whether prenatal FD is associated with neurodevelopmental disorders in offspring. ICR mice were fed a control diet (2 mg folic acid/kg diet) or a folate-deficient diet (0.3 mg folic acid/kg diet) from embryonic day 1 until parturition. We evaluated locomotor activity, anxiety, grooming, sociability and learning memory in male offspring at 7-10 weeks of age. No differences were found in locomotor activity or anxiety in the open field test, nor in grooming time in the self-grooming test. However, sociability, spatial memory, and novel object recognition were impaired in the FD mice compared with control offspring. Furthermore, we measured protein expression levels of the NMDA and AMPA receptors, as well as PSD-95 and the GABA-synthesizing enzymes GAD65/67 in the frontal cortex and hippocampus. In FD mice, expression levels of AMPA receptor 1 and PSD-95 in both regions were reduced compared with control mice. Moreover, NMDA receptor subunit 2B and GAD65/67 were significantly downregulated in the frontal cortex of prenatal FD mice compared with the controls. Collectively, these findings suggest that prenatal FD causes behavioral deficits together with a reduction in synaptic protein levels in the frontal cortex and hippocampus.

CYP2U1: An emerging treatable neurometabolic disease with cerebral folate deficiency in 2 Chinese brothers.

With the rapid advancement of medical technologies in genomic and molecular medicine, the number of treatable neurometabolic diseases is quickly expanding. Spastic paraplegia 56 (SPG56), one of the severe autosomal recessive forms of neurodegenerative disorders caused by pathogenic variants in the CYP2U1 gene, has no reported specific targeted treatment yet. Here we report 2 Chinese brothers with CYP2U1 bi-allelic pathogenic variants with cerebral folate deficiency who were treated for over a decade with folinic acid supplement. Patients have remained stable under therapy.

Haematinic deficiency in pregnancy: another HELLP mimic.

Haematinic deficiency is not uncommon in pregnancy. Folate deficiency is more common than B12 deficiency because of the increased uptake of folate in pregnancy, and the fact that B12 stores take much longer to deplete. Described here are five cases of anaemia in pregnancy secondary to severe haematinic deficiency with subsequent management and pregnancy outcomes. In the majority of cases, the women were proteinuric, but systemically well and normotensive. Thrombotic thrombocytopenic purpura and HELLP were both considered, but the identification of very abnormal folate levels of less than 3 µg/L in all and low B12 deficiency in the majority made haematinic deficiency the most likely diagnosis. They all received high dose folic acid, parenteral vitamin B12 and oral iron and made good haematological recoveries. Adequate antenatal correction of vitamin deficiency like this avoids bone marrow suppression and helps minimise poor obstetric outcomes associated with pre-existing anaemia including post-partum haemorrhage.

Protective effects of pyrroloquinoline quinone in brain folate deficiency.

BACKGROUND: Folates (Vitamin B9) are critical for normal neurodevelopment and function, with transport mediated by three major pathways: folate receptor alpha (FRα), proton-coupled folate transporter (PCFT), and reduced folate carrier (RFC). Cerebral folate uptake primarily occurs at the blood-cerebrospinal fluid barrier (BCSFB) through concerted actions of FRα and PCFT, with impaired folate transport resulting in the neurological disorder cerebral folate deficiency (CFD). Increasing evidence suggests that disorders associated with CFD also present with neuroinflammation, oxidative stress, and mitochondrial dysfunction, however the role of brain folate deficiency in inducing these abnormalities is not well-understood. Our laboratory has identified the upregulation of RFC by nuclear respiratory factor 1 (NRF-1) at the blood-brain barrier (BBB) once indirectly activated by the natural compound pyrroloquinoline quinone (PQQ). PQQ is also of interest due to its anti-inflammatory, antioxidant, and mitochondrial biogenesis effects. In this study, we examined the effects of folate deficiency and PQQ treatment on inflammatory and oxidative stress responses, and changes in mitochondrial function. METHODS: Primary cultures of mouse mixed glial cells exposed to folate-deficient (FD) conditions and treated with PQQ were analyzed for changes in gene expression of the folate transporters, inflammatory markers, oxidative stress markers, and mitochondrial DNA (mtDNA) content through qPCR analysis. Changes in cellular reactive oxygen species (ROS) levels were analyzed in vitro through a DCFDA assay. Wildtype (C57BL6/N) mice exposed to FD (0 mg/kg folate), or control (2 mg/kg folate) diets underwent a 10-day (20 mg/kg/day) PQQ treatment regimen and brain tissues were collected and analyzed. RESULTS: Folate deficiency resulted in increased expression of inflammatory and oxidative stress markers in vitro and in vivo, with increased cellular ROS levels observed in mixed glial cells as well as a reduction of mitochondrial DNA (mtDNA) content observed in FD mixed glial cells. PQQ treatment was able to reverse these changes, while increasing RFC expression through activation of the PGC-1α/NRF-1 signaling pathway. CONCLUSION: These results demonstrate the effects of brain folate deficiency, which may contribute to the neurological deficits commonly seen in disorders of CFD. PQQ may represent a novel treatment strategy for disorders associated with CFD, as it can increase folate uptake, while in parallel reversing many abnormalities that arise with brain folate deficiency.

Characterization of CircRNA-Associated CeRNA Networks in Folate Deficiency-Induced Neural Tube Defects.

Objective: Circular RNAs (circRNAs) participate in several important pathological processes and have been used in the diagnosis and treatment of various diseases. This study aimed to investigate the role of circRNAs in neural tube defects (NTDs). Method: We characterized circRNA-associated competitive endogenous RNA (ceRNA) networks in brain tissue of low folate -induced NTDs mouse at embryonic day 13.5 by high-throughput sequencing. The expression levels of Circzfp644, miR-20-5p and Gas7 were detected by RT-PCR. Gas7 and Circzfp644 functions were determined by miRNA-mimics and inhibitors in mouse teratocarcinoma cells (F9 cells), and luciferase gene reporter assay was assessed in the F9 cells. In addition, the expression levels of Circzfp644, miR-20-5p and Gas7 were determined by Nanostring in human NTDs tissues. Results: We detected 57 circRNA transcripts, 16 miRNAs, and 148 mRNAs that were significantly dysregulated in NTDs brain tissues compared with their expression levels in control (normal) tissues. Circzfp644 shared miRNA response elements with the growth arrest specific 7 ( Gas7) gene and competitively bound with miR-20-5p to increase the expression of Gas7. Downregulation of Circzfp644 and Gas7 and upregulation of miR-20-5p were found in human NTD tissue. Conclusion: This study provides new perspectives on the role of circRNAs in nervous system development and the pathogenesis of NTDs.

The Effect of Helicobacter pylori Density on Serum Vitamin B12 and Folate Levels in Patients With Non-atrophic Gastritis.

Introduction Chronic infection with Helicobacter pylori (Hp) is an essential cause of gastrointestinal pathologies in adults. Despite being a microorganism proven to play a role in vitamin B12 deficiency by causing gastric atrophy, Hp's role in patients with non-atrophic gastritis has not been fully explained. Our study investigated whether the presence and density of Hp is related to vitamin B12 and folate deficiencies in patients with non-atrophic gastritis. Methods This retrospective cohort study analyzed the following parameters, vitamin B12, folate, and mean red blood cell volume (MCV) in the hemogram; these were measured simultaneously in patients diagnosed with non-atrophic gastritis who had undergone gastroscopy to investigate Hp levels. Patients with conditions that could have caused vitamin B12 and folate deficiencies were excluded from the study. The study included 244 patients who met the criteria. The Sydney classification was used for histopathologic grading and staging of gastric biopsies of patients with gastritis. Results There was no relationship between the presence and density of Hp with vitamin B12 levels. However, folate levels were significantly lower in Hp-positive patients than in Hp-negative patients (p = 0.017). Folate levels were substantially lower in patients with chronic pan-mucosal gastritis than in patients with chronic inactive gastritis (p = 0.034). Statistically, a significant difference was found between folate levels on the basis of neutrophil activity and inflammation score (p = 0.011 and p <0.001, respectively). Conclusions Although there was no statistically significant relationship between the presence and density of Hp and vitamin B12, our study found an association between folate levels and Hp density. This may be associated with the time for the depletion of vitamin B12 and folate stores and the relatively early stage of gastritis. In cases with vitamin B12 and folate deficiencies, appropriate studies should be performed for specific epidemiological reasons in respective fields.

Effects of folate deficiency and sex on carcinogenesis in a mouse model of oral cancer.

OBJECTIVES: To investigate the effects of dietary folate and sex on histopathology of oral squamous cell carcinoma in mice. MATERIALS AND METHODS: Mice (C57Bl/6, 30/sex) were fed either a deficient folate or sufficient folate diet. Vehicle or 4-nitroquinoline1-oxide (50 µg/mL) in vehicle were administered in drinking water for 20 weeks, followed by 6 weeks of regular drinking water. Oral lesions were observed weekly. Tongues were studied for histopathologic changes. Immunohistochemical techniques were used to measure cell proliferation (Ki67+), and to quantify expression of folate receptor, reduced folate carrier, and proton-coupled folate transporter. T cells, macrophages, and neutrophils were counted and normalized to area. RESULTS: All 4NQO-treated mice developed oral tumors. Dietary folate level did not affect tumor burden. More tumors were observed on the ventral aspect of the tongue than in other locations within the oral cavity. 4-nitroquinoline-1-oxide-treated mice displayed 27%-46% significantly lower expression of all three folate transport proteins; diet and sex had no effect on folate transporter expression. T-cell and neutrophil infiltration in tongues were 9.1-fold and 18.1-fold increased in the 4-nitroquinoline-1-oxide-treated mouse tongues than in controls. CONCLUSION: Treatment with 4NQO was the primary factor in determining cancer development, decreased folate transport expression, and lymphoid cell infiltration.

A Rare Case of Folate Deficiency-Induced Subacute Combined Degeneration of the Spinal Cord: A Case Report.

Folate deficiency is a rare cause of subacute combined degeneration (SCD). SCD is characterized by demyelination of the dorsal and lateral columns of the cervical and thoracic spine most commonly caused by vitamin B12 deficiency. Folate deficiency, which can be clinically indistinguishable from B12 deficiency, leads to a variety of presentations, including absent vibratory sensation and proprioception, sensory ataxia, and progressive motor weakness. Recognizing the clinical sequelae of SCD is essential for timely diagnosis and treatment. We present a case of a 38-year-old male with progressive ascending bilateral lower extremity numbness and motor weakness in the presence of normal vitamin B12 and methylmalonic acid levels. MRI of the entire neuraxis revealed a diagnosis of SCD, which was managed with oral folate replacement. We aim to highlight this rare cause of SCD, which can lead to permanent neurological deficits if not promptly recognized and treated.

Folate Deficiency Increased Microglial Amyloid-ß Phagocytosis via the RAGE Receptor in Chronic Unpredictable Mild-Stress Rat and BV2 Cells.

Depression is often considered one of the prevalent neuropsychiatric symptoms of Alzheimer's disease (AD). ß-amyloid (Aß) metabolism disorders and impaired microglia phagocytosis are potential pathological mechanisms between depression and AD. Folate deficiency (FD) is a risk factor for depression and AD. In this study, we used a chronic unpredictable mild stress (CUMS) rat model and a model of Aß phagocytosis by BV2 cells to explore the potential mechanisms by which FD affects depression and AD. The results revealed that FD exacerbated depressive behavior and activated microglia in CUMS rats, leading to an increase in intracellular Aß and phagocytosis-related receptors for advanced glycation end products (RAGE). Then, in vitro results showed that the expression of the RAGE receptor and M2 phenotype marker (CD206) were upregulated by FD treatment in BV2 cells, leading to an increase in Aß phagocytosis. However, there was no significant difference in the expression of toll-like receptor 4 (TLR4) and clathrin heavy chain (CHC). Furthermore, when using the RAGE-specific inhibitor FPS-ZM1, there was no significant difference in Aß uptake between folate-normal (FN) and FD BV2 cell groups. In conclusion, these findings suggest FD may promote microglia phagocytosis Aß via regulating the expression of RAGE or microglia phenotype under Aß treatment.