Reduced Folate Carrier Research Articles

Allele Frequency of a Common Variants and Two Common Loss-of-Function Variants in Organic Cation Transporter 1 (OCT1) among Balinese Diabetic Patients

Metformin is the most common drug prescribed for patient with type 2 diabetes mellitus (T2DM). Although it is widely used as first line therapy for T2DM, there were huge variations in its clinical efficacy among population. It was postulated that genetic polymorphisms of metformin transporter, especially organic cation transporter 1 (OCT1) encoded by SLC22A1 gene, have a considerable effect on respon of metformin therapy. However, data for this polymorphism in Balinese population was not well established. The aim of this study was to identify genetic variation in OCT1, especially rs628031, rs122083571, and rs623442, in Balinese diabetic patients. It was a descriptive study to explore genetic variation in OCT1 encoded by SLC22A1 gene. A total of 133 diabetic patients were recruited from Departement of Internal Medicine at Sanjiwani Hospital Gianyar and Tabanan Hospital, Bali. DNA was extracted and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to assess the polymorphism rs628031. While, polymorphism rs122083571 and rs623442 were assessed by direct sequencing. The minor allele frequency (MAF) for polymorphism rs628031 in this population was 0.59 with genotype frequency of AA, AG, and GG accounted for 16.5%; 48.9%, and 34.6% respectively. Minor allele frequency for polymorphism rs623442 was 0.20 with genotype frequency of CC, CA, and AA 5.4%; 29.0%; and 65.6% respectively. Polymorphism rs122083571 was not found in this population (100% genotype CC). Genetic polymorphism of OCT1 rs628031 in this population was occurred in relatively high frequency, while polymorphism OCT1 rs623442 was occurred only in one fifth of studied population. Further studies are needed to address the effect of this polymorphism to therapeutic respons of metformin in Balinese population.

The Role of SLC22A1 and Genomic Ancestry on Toxicity during Treatment in Children with Acute Lymphoblastic Leukemia of the Amazon Region.

In Brazil, Acute lymphoid leukemia (ALL) is the leading cause of cancer deaths in children and adolescents. Treatment toxicity is one of the reasons for stopping chemotherapy. Amerindian genomic ancestry is an important factor for this event due to fluctuations in frequencies of genetic variants, as in the NUDT15 and SLC22A1 genes, which make up the pharmacokinetic and pharmacodynamic pathways of chemotherapy. This study aimed to investigate possible associations between NUDT15 (rs1272632214) and SLC22A1 (rs202220802) gene polymorphism and genomic ancestry as a risk of treatment toxicities in patients with childhood ALL in the Amazon region of Brazil. The studied population consisted of 51 patients with a recent diagnosis of ALL when experiencing induction therapy relative to the BFM 2009 protocol. Our results evidenced a significant association of risk of severe infectious toxicity for the variant of the SLC22A1 gene (OR: 3.18, p = 0.031). Genetic ancestry analyses demonstrated that patients who had a high contribution of African ancestry had a significant protective effect for the development of toxicity (OR: 0.174; p = 0.010), possibly due to risk effects of the Amerindian contribution. Our results indicate that mixed populations with a high degree of African ancestry have a lower risk of developing general toxicity during induction therapy for ALL. In addition, individuals with the SLC22A1 variant have a higher risk of developing severe infectious toxicity while undergoing the same therapy.

Association of Auto-Antigen SLC30A8 Gene Variants with Type 1 Diabetes Mellitus

Type 1 Diabetes Mellitus (T1DM), is a genetic disease, the prevalence of which is increasing due to delays in the diagnosis because of the absence of standard antibodies. Therefore, there is a need for a molecular variant that can help in early diagnosis in these patients. The polymorphism in the SLC30A8 gene can identify the people at risk of T1DM. However, there is a controversy in the association of the SLC30A8 gene in the pathogenesis of T1DM and a dearth of data in our part of the world. Therefore, we aimed to determine the most frequent autoantigen SLC30A8 genotype and its association with T1DM in the Pakistani population. This case-control study was carried out at Ziauddin Medical University (ZMU) jointly with Baqai Institute of Diabetology and Endocrinology (Baqai Medical University) from June to October 2019. A total of 50 subjects were enrolled (25 cases and 25 controls) in the study. Cases included 25 diagnosed patients of T1DM meeting American Diabetes Association (ADA) new criteria and controls were their first-degree relatives. Blood was drawn, DNA was extracted and amplified through PCR. The RFLP of PCR product was done using a restriction enzyme, Alu I for genotyping. The most frequently observed genotype was CC among cases as well as controls. The CC genotype of rs13266634 was not found significantly associated with T1DM (p=0.08) but the OR was 2.7; CI=0.86 -9.00. Similarly other genotypes were also not found statistically significant. However, HbA1C and Fasting Blood Sugar (FBS) were found statistically significant (p=0.001, p=0.000) in T1DM patients compared to controls. The autoantigenic variants of SLC30A8 of rs13266634 were not found statistically significant with T1DM. The role of this variant as a susceptibility gene in T1DM development should be further confirmed by carrying out studies with a larger sample size.

Luteolin Enhances Choroid Plexus 5-MTHF Brain Transport to Promote Hippocampal Neurogenesis in LOD Rats.

Folates, provided by food, are commonly used antidepressant synergists in late-onset depression (LOD). However, increased intake of folic acid in the elderly population might lead to the accumulation of unmetabolized folic acid in the systemic circulation, leading to enhanced deterioration of the central nervous system function. In addition, folates cannot access the brain directly because of the blood–brain barrier. Choroid plexus (CP) 5-methyltetrahydrofolate (5-MTHF) brain transport plays a critical role in regulating the cerebrospinal fluid (CSF) 5-MTHF content. Luteolin is a natural flavonoid that has antidepressant effects and is involved in the anti-folate resistance pathway. It remains unclear whether the antidepressant effects of luteolin are associated with the CP 5-MTHF brain transport. In this study, 20–21-month-old Wistar rats were exposed to the chronic unpredictable mild stress (CUMS) protocol for 6 consecutive weeks to explore the long-term effects of luteolin on behavior, 5-MTHF levels, hippocampal neurogenesis, and folate brain transport of the CP. In vitro primary hippocampal neural stem cells (NSCs) cultured in media containing 10% CSF from each group of rats and choroid plexus epithelial cells (CPECs) cultured in media containing 20 μM luteolin were treated with 100 μM corticosterone and 40 mg/ml D-galactose. We found that aged rats exposed to CUMS showed a significantly reduced sucrose preference, decreased locomotion activity in the open field test and accuracy of the Morris water maze test, increased immobility time in the forced swimming test, accelerated dysfunctional neurogenesis and neuronal loss in the dentate gyrus of LOD rats, as well as decreased CSF and hippocampus 5-MTHF levels, and zona occludens protein 1 (ZO-1), proton-coupled folate transporter (PCFT), and reduced folate carrier (RFC) protein levels. In vitro assays showed media containing 10% aged CSF or LOD+ Luteolin-CSF significantly increased the viability of CORT + D-gal-injured NSCs and alleviated dysfunctional neurogenesis and neuronal loss compared with the CORT + D-gal medium. However, media containing 10% LOD-CSF had no such effect. In the meantime, induction of CORT + D-gal significantly decreased the ZO-1, PCFT, RFC, and folate receptor alpha (FR-α) protein levels and transepithelial electrical resistance in rat CPECs. As expected, luteolin treatment was effective in improving these abnormal changes. These findings suggested that luteolin could ameliorate CUMS-induced LOD-like behaviors by enhancing the folate brain transport.

Pan-Cancer Analyses Confirmed the Ferroptosis-Related Gene SLC7A11 as a Prognostic Biomarker for Cancer.

PurposeFerroptosis is an iron-dependent and reactive oxygen species (ROS)-reliant form of cell death, exhibiting cellular, molecular, and gene-level characteristics distinct from those of necrosis, autophagy, apoptosis, and pyroptosis. Solute carrier family 7 member 11 (SLC7A11), which encodes a cystine/glutamate antiporter transmembrane protein, inhibits ferroptosis by importing cystine and promoting glutathione (GSH) biosynthesis and was found to be overexpressed in multiple human cancers. However, the specific role and underlying mechanism of SLC7A11 in cancers remains poorly characterized. This research aimed to identify the relationship between SLC7A11 expression and tumor microenvironment and visualize its prognostic value in pan-cancer.Patients and MethodsTranscriptomic data for 6313 tumors and normal samples across 20 cancer types were acquired from The Cancer Genome Atlas (TCGA) database. Besides, we presented a novel bioinformatics pipeline that uncovered the impacts of SLC7A11 on cancer prognosis, tumor mutational burden (TMB), immune cell infiltration in tumor microenvironment, and drug responses. The Genotype-Tissue Expression (GTEx), cBioportal, TCGA and Connectivity Map (CMap) databases were used to explore the expression, genetic alterations, immune microenvironment, and drug responses of SLC7A11. A series of deconvolution algorithms, including EPIC, CIBERSORT and GSEA, were utilized for multidimensional analyses of the cancer transcriptomic data.ResultsSLC7A11 was found to be highly expressed in the 20 types of cancer, especially in solid tumors. Survival analysis uncovered that most cancer patients with up-regulated expression of SLC7A11 showed poor prognosis, suggesting that SLC7A11 is a potential oncogene in most cancer types. Furthermore, the expression level of SLC7A11 was confirmed to be associated with immune cell infiltration in tumor microenvironment, TMB, and drug responses. Gene set enrichment analysis (GESA) revealed that dysregulation of SLC7A11 was associated with metabolic and immunity-related signaling pathways in the cancers.ConclusionThe comprehensive pan-cancer analyses identified SLC7A11 as an attractive biomarker for immune infiltration and poor prognosis in cancers, shedding new light on the therapeutics of cancers.

The influence of SLC22A3 rs543159 and rs1317652 genetic variants on metformin therapeutic efficacy in newly diagnosed patients with type 2 diabetes mellitus: 25 weeks follow-up study

Background and aimsAmong anti-diabetic medications, metformin has been proven to be the preferred initial pharmacologic agent for type 2 diabetes mellitus (T2DM) treatment. Despite its safety and efficacy, the response to metformin varies between individuals. Genetic variations, especially within genes involved in pharmacokinetics and pharmacodynamics of metformin (e.g SLC22A3), have been suggested to be responsible for the observed inter-individual differences. By considering the undeniable role of organic cation transporter 3 in hepatic uptake of metformin, this study was aimed to investigate the association of rs543159 and rs1317652 variants in SLC22A3 gene with response to metformin monotherapy in newly diagnosed patients with T2DM. MethodsThe study included 200 T2DM patients who received metformin monotherapy for 25 weeks. The patients were classified into 2 groups according to their HbA1c values: the responders (reduction in HbA1c levels by at least 1% after 25 weeks treatment with metformin) and non-responders (less than 1% reduction in HbA1c levels after 25 weeks treatment with metformin). We used tetra ARMS-PCR method to determine genotypes of the target variants. ResultsFor the rs543159, CA and AA genotypes were more frequent in responders as compared to non-responders (OR = 2.48; 95% CI = 1.28–4.78, P-value = 0.0057) under the dominant model. In case of rs1317652 CC and CT genotypes were more frequent in metformin responders as compared to non-responder group (OR = 2.49; 95% CI = 1.32–4.70, P-value = 0.0043) under the dominant model. Parameters such as fasting blood sugar (FBS), HbA1c, and total cholesterol (TC) levels were significantly lower in the responder group after 25 weeks of metformin monotherapy. Moreover, according to the result of multiple linear regression rs543159 and base line HbA1c values are significantly associated with response to metformin monotherapy. ConclusionOur results suggested that rs543159 and rs1317652 in SLC22A3 gene might be associated with variability in response to metformin therapy in T2DM patients.

A Metformin Pharmacogenetic Study of Patients with Type 2 Diabetes Mellitus and SLC22A1 Gene Mutation

Background: The purpose of this study was to determine the profiles of patients with type 2 diabetes (T2DM) and an SLC22A1 gene mutation in order to evaluate the effect of metformin pharmacogenetics.
 Methods: To assess the effect of pharmacogenetics, a mutation of the SLC22A1 gene in T2DM patients receiving metformin was investigated. Blood samples were taken from 50 diabetics of Minangkabau ethnicity who met the inclusion criteria, and SNP genotyping and blood glucose levels were determined. DNA is extracted and purified from blood samples using DNAzol® Genomic DNA Kits (Thermofischer Scientific) reagents. The Chi-square test and Independent sample T test were used to analyze the data. A statistically significant association was defined as a p-value < 0.05. Finally, the GraphPad Prism 7.00 program was used to gather and analyze data.
 Results: The adjusted odds ratio for inadequate fasting blood glucose was 1.48 (95% CI 1.18-1.95) in this study, while the adjusted odds ratio for diet discipline was 1.23 (95% CI 1.18-1.95). The adjusted odds ratio for low physical activity was 1.18. (95% CI 1.05-1.81). According to the sequencing data, the proportion of mutants is high at exon 2 rs683369 (G> C), while the percentage of wildtype and heterozygous mutants is the same at introns rs4646272 (T> G).
 Conclusion: Obesity, diet discipline, and low physical activity were all found to increase the likelihood of insufficient fasting blood glucose in T2DM patients. Exon 2 rs683369 (G> C) has a high proportion of mutants, but introns rs4646272 (T> G) have the same percentage of wildtype and heterozygous mutants.

The Dual Regulation Effects of ESR1/NEDD4L on SLC7A11 in Breast Cancer Under Ionizing Radiation.

Radiotherapy is one of the most important treatments for breast cancer. Ferroptosis is a recently recognized form of regulated cell death that is characterized by lipid peroxidation. However, whether ionizing radiation (IR) could induce ferroptosis in breast cancer and how it works remain unknown. Bioinformatics analysis were performed to screen ferroptosis-related genes differentially expressed in breast tumor tissue and normal tissue. Then, breast cancer cell lines with different estrogen receptor (ER) phenotypes were used for studies in vitro, including ER-positive (MCF-7 and ZR-75-1) and ER-negative (MDA-MB-231) cells. The dynamic changes of mRNA and protein levels were examined after x-ray of 8 Gy by qRT-PCR and Western blotting, respectively. Immunoprecipitation (IP) was used to explore the interaction between proteins. Luciferase assay was used to analyze the transcriptional regulation effect of ESR1 on SLC7A11. BODIPY C11 and trypan blue dyes were used to determine lipid peroxidation and cell death, respectively. The result showed that the ferroptosis-related gene SLC7A11 was higher in breast cancer tissues compared with normal tissues and associated with poor survival. A positive correlation exists between ESR1 and SLC7A11 expression. ESR1 promoted SLC7A11 expression at the early stage after IR. ESR1/SLC7A11 knockdown significantly enhanced IR-induced ferroptosis in ER-positive cells. At 12 h after IR, the IP data showed the interaction between E3 ubiquitin ligase NEDD4L and SLC7A11 increased, followed by the ubiquitylation and degradation of SLC7A11. Thus, SLC7A11 expression was regulated by both ESR1 and NEDD4L, in opposite ways. For the first time, we elucidated that ESR1 and NEDD4L functioned together after radiation treatment and finally induced ferroptosis in breast cancer cells, which provides novel insight into the guidance of clinical treatment of breast cancer.

Genetic Association Between SLC22A12 Variants and Susceptibility to Hyperuricemia: A Meta-Analysis.

Aims: Gout is a form of inflammatory arthritis characterized by the deposition of monosodium urate crystals. An important risk factor for gout is hyperuricemia. The relationship between SLC22A12 gene variants and the susceptibility to hyperuricemia has been reported, but these findings have been inconsistent. Thus, we aimed to assess the relationship between SLC22A12 gene variants and hyperuricemia susceptibility through a meta-analysis. Methods: The meta-analysis was performed by searching PubMed, Embase, Web of Science, and Chinese National Knowledge Infrastructure (CNKI) databases. The relationship between hyperuricemia risk and the SLC22A12 rs11602903, rs524023, rs3825018, rs3825016, rs11231825, rs7932775, rs893006, and rs475688 variants was assessed by odds ratios and 95% confidence intervals. Results: In total, 20 eligible publications with 4817 cases and 6819 controls were included in the meta-analysis. Hyperuricemia risk was significantly associated with the SLC22A12 alleles rs3825018, rs7932775, and rs475688 under both the dominant and recessive models and with rs3825016 under the allelic and dominant models. Conclusions: Under the allelic model SLC22A12 rs3825018 and rs3825016 were risk factors for hyperuricemia and gout as was rs7932775 under dominant and recessive models, while the SLC22A12 rs475688 was protective against hyperuricemia under both dominant and recessive models.

One‐carbon metabolism pathway genes and their non‐association with the development of amyotrophic lateral sclerosis

Although of unknown etiology, some mechanisms associated with the metabolic cycle of folate are speculated to be related to the genesis of amyotrophic lateral sclerosis (ALS). Thus, the aim of the study was to analyze the role of genetic polymorphisms rs1051266 in SLC19A1 gene and rs1805087 in MTR gene and their associations with ALS development. A case-control study was conducted with 101 individuals with ALS and 119 individuals without diagnosis of neurodegenerative diseases, from the Brazilian central population. The polymorphisms were determined using the polymerase chain reaction-restriction fragment length polymorphism technique. The results showed no statistically significant differences, even when genotypes were analyzed by the dominant, recessive, codominant, and overdominant inheritance models. It was observed a statistical significance relating alcohol consumption with individuals in the case group (p = 0.01). Therefore, the need for more studies to evaluate the influence of genetic variants is highlighted, seeking to provide information on the etiopathogenesis of ALS.

The Role of NF-kB in the Downregulation of Organic Cation Transporter 2 Expression and Renal Cation Secretion in Kidney Disease

Organic cation transporter 2 (OCT2), encoded by the SLC22A2 gene, is the main cation transporter on the basolateral membrane of proximal tubular cells. OCT2 facilitates the entry step of the vectorial transport of most cations from the peritubular space into the urine. OCT2 downregulation in kidney disease models is apparent, yet not clear from a mechanistic vantage point. The aim of this study was to explore the role of inflammation, a common thread in kidney disease, and NF-kB in OCT2 modulation and tubular secretion. Among the OCTs, OCT2 was found consistently downregulated in the kidney of rats with chronic kidney disease (CKD) or acute kidney injury (AKI) and in patients diagnosed with CKD, and it was associated with the upregulation of TNFα renal expression. Exposure to TNFα reduced the expression and function of OCT2 in primary renal proximal tubule epithelial cells (RPTEC). Silencing or pharmacological inhibition of NF-kB rescued the expression of OCT2 in the presence of TNFα, indicating that OCT2 repression was NF-kB-dependent. In silico prediction coupled to gene reporter assay demonstrated the presence of at least one functional NF-kB cis-element upstream the transcription starting site of the SLC22A2 gene. Acute inflammation triggered by lipopolysaccharide injection induced TNFα expression and the downregulation of OCT2 in rat kidney. The inflammation did reduce the active secretion of the cation Rhodamine 123, with no impairment of the glomerular filtration. In conclusion, the NF-kB pathway plays a major role in the transcriptional regulation of OCT2 and, in turn, in the overall renal secretory capacity.

Integrative Analysis Uncovers Metabolic Subtypes with Potential Therapeutic Target in Resectable Pancreatic Cancer

Introduction: Pancreatic cancer is a devastating disease with a high relapse rate, even in resectable pancreatic cancer. This study aimed to identify the prognostic significance and therapeutic chance of the metabolic subtypes for resectable pancreatic cancer. Method: We obtained transcriptomic data from the TCGA-PAAD cohort via the The Cancer Genome Atlas (TCGA) data portal (n=182). After integrative analysis of transcriptomic data in the discovery cohort, immunohistochemical (IHC) staining was performed in the independent cohort to validate the molecule of interest. Experimental testing for the molecule of interest was performed using pancreatic cancer cell lines, including AsPC1, BxPC3, MIA PaCa-2, and PANC-1 in vitro. Results: Two subtypes showing distinct gene expression patterns in the TCGA-PAAD dataset were identified. The active glucose metabolism subtype showed significantly lower survival regarding cancer relapse after surgical resection. The genes SLC2A1 (GLUT1) and SLC16A3 (MCT4) were highly enriched in the active metabolism subtype. The validation cohort showed high IHC staining intensity for MCT4 and a significantly high relapse rate (P=0.01). Several molecular pathways associated with aggressive tumor biology regarding cell cycle, Myc, and mTOR downstream signaling were highly enriched in the high glucose uptake subtype as well as distinct response for immunotherapy. MCT4 inhibition suppressed pancreatic cancer cell lines in vitro and showed a synergetic effect with gemcitabine treatment. Conclusion: MCT4 was identified from integrative analysis as a potential therapeutic target in resectable pancreatic cancer. The precision strategy for resectable pancreatic cancer should be validated in a clinical setting with a prospective study design.

Perspective: The High-Folate–Low-Vitamin B-12 Interaction Is a Novel Cause of Vitamin B-12 Depletion with a Specific Etiology—A Hypothesis

Vitamin B-12 is a water-soluble vitamin that plays important roles in intermediary metabolism. Vitamin B-12 deficiency has many identifiable causes, including autoimmune and other gastrointestinal malabsorption disorders, dietary deficiency, and congenital defects in genes that are involved in vitamin B-12 trafficking and functions. Another putative cause of vitamin B-12 deficiency is the high-folate-low vitamin B-12 interaction, first suspected as the cause for observed relapse and exacerbation of the neurological symptoms in patients with pernicious anemia who were prescribed high oral doses of folic acid. We propose that this interaction is real and represents a novel cause of vitamin B-12 depletion with specific etiology. We hypothesize that excessive intake of folic acid depletes serum holotranscobalamin (holoTC), thereby decreasing active vitamin B-12 in the circulation and limiting its availability for tissues. This effect is specific for holoTC and does not affect holohaptocorrin, the inert form of serum vitamin B-12. Depletion of holoTC by folic acid in individuals with already low vitamin B-12 status further compromises the availability of vitamin B-12 coenzymes to their respective enzymes, and consequently a more pronounced state of biochemical deficiency. This hypothesis is drawn from evidence of observational and intervention studies of vitamin B-12-deficient patients and epidemiological cohorts. The evidence also suggests that, in a depleted state, vitamin B-12 is diverted to the hematopoietic system or the kidney. This most likely reflects a selective response of tissues expressing folate receptors with high affinity for unmetabolized folic acid (UMFA; e.g., hematopoietic progenitors and renal tubules) compared with those tissues (e.g., liver) that only express the reduced folate carrier, which is universally expressed but has poor affinity for UMFA. The biochemical and physiological mechanisms underlying this interaction require elucidation to clarify its potential public health significance.

LncRNA T-UCR Uc.339/miR-339/SLC7A11 Axis Regulates the Metastasis of Ferroptosis-Induced Lung Adenocarcinoma.

Lung adenocarcinoma progression is closely linked to ferroptosis suppression. Emerging studies have found that the expression of its related gene SLC7A11 may be regulated by LncRNA. However, the mechanism of LncRNA in affecting the development of SLC7A11-mediated lung adenocarcinoma remains unclear. Here, we identified a Uc.339/miR-339/SLC7A11 axis that involves LncRNA T-UCR Uc.339-mediated repression of miR-339 and affects the expression of SLC7A11 to participate in tumor metastasis and development. In this study, we identified Uc.339 as upregulated in patients with lung adenocarcinoma. RAP-qPCR proved that LncRNA Uc.339 competitively binds to pri-miR-339 and inhibits the production of mature miR-339. The interaction between miR-339 and SCL7A11 was confirmed by luciferase reporter assay. The Uc.339/miR-339/SLC7A11 axis regulated the proliferation, migration and invasion of A549 and H1299cells in vitro by affecting ferroptosis. Finally, in mouse xenograft models, knocking down Uc.339 in LLC cells was able to inhibits tumor growth by blocking the axis of Uc.339/miR-339/SLC7A11 in vivo, but miR-339 inhibitors could reverse this inhibition. Taken together, our results uncovered a Uc.339/miR-339/SLC7A11 axis that leads to defects in the ferroptosis in lung cancer, and constitutes a potential mechanism that drives the metastasis of lung adenocarcinoma.

Interaction between dolutegravir and folate transporters and receptor in human and rodent placenta.

SummaryBackgroundDue to the critical role of folates in neurodevelopment, it is important to understand potential interactions between anti-HIV drugs used during pregnancy, and folate delivery pathways in the placenta. This study investigates the effect of dolutegravir (DTG) exposure on the functional expression of the reduced folate carrier (RFC), proton-coupled folate transporter (PCFT), and folate receptor-α (FRα) in the placenta.MethodsHuman placental cell lines, human placental explants, and a pregnant mouse model treated with clinically relevant concentrations of DTG were used. Gene and protein expression were assessed by qPCR, immunoblot and immunohistochemical assays. Folate transport function was measured by applying radioisotope-based transport assays.FindingsIn placental cells, clinically relevant DTG exposure for 3h or 6h was associated with a modest but significant reduction in the expression of RFC and PCFT both at the mRNA and protein levels, as well as decreased uptake of RFC and PCFT substrates [3H]-methotrexate and [3H]-folic acid, respectively. In pregnant mice, DTG administration was associated with an increase in both placental RFC and PCFT mRNA expression, accompanied by a decrease in placental FRα mRNA under folate-deficient dietary conditions.InterpretationThese findings demonstrate a potential interaction between DTG and folate transport pathways in the placenta, particularly in vivo, under folate deficient conditions, potentially impacting folate delivery to the foetus in the context of DTG-based ART during pregnancy.FundingFunded by Ontario HIV Treatment Network, grant #506657; and Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health, award #R01HD104553.

Genomic imprinting of the IGF2R/AIR locus is conserved between bovines and mice

Genomic imprinting is an epigenetic phenomenon that leads to genes monoallelically expressed in a parent-of-origin-specific manner and plays an important role in the embryonic development and postnatal growth of mammals. Imprinted genes usually occur in clusters in a chromosomal region and are regulated by a cis-acting imprinting control region that involves differential DNA methylation modification. Igf2r, Slc22a2 and Slc22a3 are three maternally expressed genes on mouse chromosome 17. The paternally expressed long noncoding RNA (lncRNA) Air and the nonimprinted gene Slc22a1 are also located in the imprinted region. Comparative characterization of imprinted clusters between species is useful for us to understand the biological significance and epigenetic regulating mechanism of genomic imprinting. The aim of this study was to analyze the allelic expression pattern of AIR and SLC22A1-3 genes in cattle and to determine the role of DNA methylation in regulating gene expression. Allelic expression analysis was performed in bovine adult tissues and term placenta using an SNP-based approach. We found that IGF2R, AIR and SLC22A3 were monoallelically expressed in all detected bovine somatic tissues, including heart, liver, spleen, lung, kidney, muscle, fat and brain. In bovine placenta, IGF2R and SLC22A3 are maternally expressed; however, the AIR gene is paternally expressed. Tissue-specific monoallelic expression of SLC22A2 is detected in bovines, with monoallelic expression in the spleen and brain but biallelic expression in kidney tissues. SLC22A1 is only detected in bovine liver and kidney tissues and is biallelicly expressed, which is consistent with the imprint expression in mice. To determine the possible role of DNA methylation in regulating the monoallelic/imprinted expression of bovine IGF2R, AIR, SLC22A2, and SLC22A3 genes, we analyzed the DNA methylation status of CpG islands in the first exon of SLC22A2, the promoter region of SLC22A3 and region 2 in the second intron of the IGF2R gene by bisulfite sequencing. Two differentially methylated regions (DMRs) were detected in the first exon of bovine SLC22A3 and the common regions of IGF2R and AIR. This suggests that DNA methylation is involved in the regulation of monoallelic/imprinted expression of IGF2R, AIR and SLC22A3 genes in cattle.

Genetic variants in SLC22A1 are related to serum lipid levels in Mexican women

Dyslipidemia is the main risk factor for coronary artery disease and is characterized by alterations in concentrations of lipids, including low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), and triacylglycerols. The participation of several genes in the development of dyslipidemia has been evidenced. Genetic variants in SLC22A1 have been associated with elevated cholesterol and LDL-c levels. The aim of this study was to evaluate the association between single-nucleotide polymorphisms (SNPs) in the SLC22A1 gene with atherogenic risk lipid levels in Mexican women. Anthropometric and biochemical measurements were performed, and four SNPs in SLC22A1 were genotyped by real-time polymerase chain reaction. The Hardy-Weinberg equilibrium was verified, and haplotype frequencies were calculated. We found significant differences between the allele frequencies of the SNPs analyzed with those reported in Mexico and in the world, which could be due to differences in the historical admixture of the women studied. Generalized linear models were evaluated to determine the association between genotypes and haplotypes with lipids levels. We identified a significant increase in total cholesterol and LDL-c levels in women who were carriers of the GA and AG genotypes of the polymorphisms rs628031 and rs594709, respectively, significant effect that is also shown in a dominant inheritance model. Interestingly, we identified an important relationship of the AGC-GAT haplotype with the elevation in LDL-c levels and AGA-GAT haplotype with the elevation in HDL-c levels. On the other hand, we found a strong linkage disequilibrium between the polymorphisms studied. Our results show that variants in the SLC22A1 gene influence serum levels of atherogenic risk lipids, suggesting that these variants probably affect the function of organic cation transporter-1 and therefore, on the regulation of lipid metabolism.

Association between a SLC23A2 Gene Variation, Plasma Vitamin C Levels, and Risk of Different Diseases

Background: Vitamin C is an important plasma water-soluble antioxidant that plays an essential role in the absorption of iron, detoxification of exogenous compounds, and remaking vitamin E for the protection of lipid membranes. In addition, vitamin C is essential in the synthesis of collagen. Vitamin C concentrations of plasma are determined by dietary intake and genetic factors. Ascorbic acid is the functional form of vitamin C, which is transported into the cell through sodium vitamin C transporters (SVCTs). There are two forms of SVCTs which are SVCT1 encoded by the SLC23A1 gene and SVCT2 encoded by the SLC23A2. The SLC23A2 gene locus on human chromosome 20P12. It expresses in most human tissues, except lung and skeletal muscle that it is important in regulating the intracellular concentration of ascorbic acid to protect the cell from oxidative stress and promote type 1 collagen maturation. Maintaining proper concentrations of plasma and cellular vitamin C concentration is important for the normal metabolic function of the body and preventing several diseases. In the contrast, a low concentration of vitamin C caused by SLC23A2 variation can cause several chronic diseases. Our systematic review discusses four diseases related to the variation of SLC23A2 gene and plasma vitamin C levels which are glaucoma, acute coronary syndrome among women, gastric cancer, and HPV16-associated head and neck cancer.
 Methods: By using NCBI databases, specifically GenBank to analyze DNA sequence and mRNA sequence of SLC23A2 gene. GenBank file format was helpful to extract an accession number of the gene, number of amino acids, number of exons and introns, and length of nucleotides. FASTA format was also useful to retrieve the nucleotide sequence and get the function of the protein. BLAST was used to compare the protein product of the SLC23A2 gene between humans and Macaca mulatta (Rhesus monkey).
 Results: the accession number of the SLC23A2 gene was NC_000020.11, the number of exons found was 18, and the gene was located in chromosome 20. This gene encodes one of the two required transporters, and the encoded protein accounts for tissue-specific uptake of vitamin C. This gene had an official symbol of SLC23A1. And they found a significant association between the single-nucleotide polymorphism (SNP) rs1279683 (A > G) in SLC23A2 and an increased risk of POAG in homozygous G allele (GG) carriers. Also, POAG patients with this SNP appear to have a significantly lower level of plasma vitamin C compared to other genotypes. Finally, many organisms have the same gene, such as dogs, mice, rats, and chickens.
 Conclusion: there is a significant association between SLC23A2 gene mutation, increased risk for vitamin C deficiency, and several diseases. SNP in the SLC23A2 gene was significantly associated with a higher risk of POAG in GG allele carriers as well as lower plasma vitamin C concentration.

Ferroptosis-associated gene SLC7A11 is upregulated in NSCLC and correlated with patient’s poor prognosis: An integrated bioinformatics analysis

Abstract Objective Ferroptosis is a type of programmed cell death dependent on iron and characterized by the accumulation of lipid peroxides, which was involved in the progression of malignant tumors including non-small cell lung cancer (NSCLC). Material/methods Ferroptosis inhibiting gene solute carrier family 7 member 11 (SLC7A11) mRNA expression was investigated in the database of TCGA and Oncomine and compared between the cancer tissue and the normal corresponding tissue of NSCLC patients. SLC7A11 gene mutation of NSCLC was investigated in the TCGA database by the online data analysis tool of Catalog of Somatic Mutations in Cancer (COSMIC) and cBioPortal. The protein–protein interaction (PPI) network of SLC7A11 and associated genes were constructed with the STRING database. Gene ontology (GO) and the KEGG pathway of genes involved in the PPI network were explored and demonstrated by a bubble plot. Progression-free survival (PFS), overall survival (OS) and postprogression survival (PPS) between SLC7A11high and SLC7A11low expression groups were compared and demonstrated by the survival curve. Results SLC7A11 mRNA was upregulated in cancer tissues compared to paired normal tissues in colorectal adenocarcinoma, esophageal squamous cell carcinoma, lung squamous cell carcinoma rectum adenocarcinoma and uterine corpus endometrial carcinoma. Missense and synonymous substitutions were 66.67% and 16.67% for lung squamous cell carcinoma. For lung adenocarcinoma, the missense and synonymous substitutions were 66.67% and 33.33% respectively. In the case of single nucleotide mutation, A>T, C>G, G>A, G>T for lung squamous cell carcinoma and G>T, C>A, G>A, T> for lung adenocarcinoma were the most common mutations in the SLC7A11 coding strand. Fifty-one genes were included in the PPI network with an edge number of 287, average node degree of 11.3 and local clustering coefficient of 0.694, which demonstrated that the PPI network was enriched significantly (p = 1.0 × 10−16). In terms of the KEGG pathway, the SLC7A11 and PPI-involved genes were mainly enriched in ferroptosis, NSCLC, pathways in cancer, tp53 signaling pathway, etc. The overall survival (OS) in the SLC7A11high group was significantly lower than those of SLC7A11low groups in NSCLC (HR = 1.15, 95% CI: 1.02–1.31, p = 0.027). However, the progression-free survival (PFS) (HR = 1.17, 95% CI: 0.97–1.42, p = 0.098) and postprogression survival (PPS) (HR = 1.00, 95% CI: 0.78–1.29, p = 0.97) between SLC7A11high and SLC7A11low expression groups were not statistically different. Conclusion SLC7A11 was upregulated in NSCLC and correlated with the patient’s poor overall survival. SLC7A11 may be a potential target for NSCLC treatment through the ferroptosis pathway.

Genome-wide association study and genomic heritabilities for blood protein levels in Lori-Bakhtiari sheep

Serum protein levels are related to physiological and pathological status of animals and could be affected by both genetic and environmental factors. This study aimed to evaluate genetic variation of serum protein profile in sheep. Blood samples were randomly collected from 96 Lori-Bakhtiari ewes, a heavy meat-type breed. Total protein, albumin, globulin, α1, α2, β and γ globulins and IgG levels were measured in blood serum. The samples were genotyped using the Illumina OvineSNP50 BeadChip. The studied traits adjusted for age, birth type, birth season and estimate of breeding value for body weight were considered as pseudo-phenotypes in genome-wide association analysis. In the GWAS model, the first five principal components were fitted as covariates to correct the biases due to possible population stratification. The Plink, R and GCTA software were used for genome-wide association analysis, construction of Q-Q and Manhattan plots and estimation of genetic variances, respectively. Noticeable genomic heritabilities ± SE were estimated for total and γ globulins (0.868 ± 0.262 and 0.831 ± 0.364, respectively), but other protein fractions had zero or close to zero estimates. Based on the Bonferroni adjusted p values, four QTLs located on 181.7 Mbp of OAR3, 107.7 Mbp of OAR4, 86.3 Mbp of OAR7 and 83.0 Mbp of OAR8 were significantly associated with α1, β, β and γ globulins, respectively. The results showed that the PKP2, IGF2R, SLC22A1 and SLC22A2 genes could be considered as candidate genes for blood serum proteins. The present study showed significant genetic variations of some blood protein fractions.