Protein kinase�C promotes choline transporter‑like protein�1 function via improved cell surface expression in immortalized human hepatic cells

Ishikawa, Takuya; Suwanai, Hirotsugu; Shikuma, Junpei; Suzuki, Ryo; Yamanaka, T.; Odawara, Masato; Inazu, Masato

doi:10.3892/mmr.2019.10894

Cited by 4 publications

(3 citation statements)

References 41 publications

(40 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…SAM is synthesized via choline oxidase in the inner mitochondrial membrane. Previous studies have suggested that CTL2 uptakes choline in the mitochondria, synthesizes SAM, a methyl donor, via choline oxidation, and is involved in DNA methylation [ 18 , 38 ]. Recent studies have shown that the CTL2 protein is expressed in the mitochondria isolated from platelets, and choline uptake was confirmed [ 15 ].…”

Section: Discussionmentioning

confidence: 99%

Functional Expression of Choline Transporters in Human Neural Stem Cells and Its Link to Cell Proliferation, Cell Viability, and Neurite Outgrowth

Fujita

Nagakura

Uchino

et al. 2021

Cells

Self Cite

View full text Add to dashboard Cite

Choline and choline metabolites are essential for all cellular functions. They have also been reported to be crucial for neural development. In this work, we studied the functional characteristics of the choline uptake system in human neural stem cells (hNSCs). Additionally, we investigated the effect of extracellular choline uptake inhibition on the cellular activities in hNSCs. We found that the mRNAs and proteins of choline transporter-like protein 1 (CTL1) and CTL2 were expressed at high levels. Immunostaining showed that CTL1 and CTL2 were localized in the cell membrane and partly in the mitochondria, respectively. The uptake of extracellular choline was saturable and performed by a single uptake mechanism, which was Na+-independent and pH-dependent. We conclude that CTL1 is responsible for extracellular choline uptake, and CTL2 may uptake choline in the mitochondria and be involved in DNA methylation via choline oxidation. Extracellular choline uptake inhibition caused intracellular choline deficiency in hNSCs, which suppressed cell proliferation, cell viability, and neurite outgrowth. Our findings contribute to the understanding of the role of choline in neural development as well as the pathogenesis of various neurological diseases caused by choline deficiency or choline uptake impairment.

show abstract

Section: Discussionmentioning

confidence: 99%

Functional Expression of Choline Transporters in Human Neural Stem Cells and Its Link to Cell Proliferation, Cell Viability, and Neurite Outgrowth

Fujita

Nagakura

Uchino

et al. 2021

Cells

Self Cite

View full text Add to dashboard Cite

show abstract

“…Levels of mRNA expression were measured according to previously established methods [ 19 , 42 , 43 ]. Total RNA was extracted from SIM-A9 cells using QIA shredder and RNeasy Mini Kit (Qiagen Inc., Valencia, CA, USA) according to the manufacturer’s instructions.…”

Section: Methodsmentioning

confidence: 99%

“…The subcellular localization of CTL1 and CTL2 proteins in SIM-A9 cells was performed using immunocytochemistry with reference to previous publications [ 17 , 42 , 43 ]. SIM-A9 cells were washed with Dulbecco’s Phosphate Buffered Saline (D-PBS) (Wako), lysed in RIPA buffer (Santa Cruz Biotechnology, Inc., Dallas, TX, USA) including 1 mM ethylenediaminetetraacetic acid and a protease inhibitor cocktail on ice, and centrifuged at 14,000× g for 15 min at 4 °C.…”

Section: Methodsmentioning

confidence: 99%

Functional Expression of Choline Transporters in Microglia and Their Regulation of Microglial M1/M2 Polarization

Okada

Muto²,

Yamanaka³

et al. 2022

IJMS

Self Cite

View full text Add to dashboard Cite

Background: Microglia are key cells of the immune system in the central nervous system and are suggested to be deeply involved in the development of neurodegenerative diseases. It is well known that microglia have functional plasticity, with an inflammatory M1 phenotype and an anti-inflammatory M2 phenotype. Inhibition of choline transport in macrophages has been reported to suppress the secretion of inflammatory cytokines. However, the role of the choline transport system in regulating microglial M1/M2 polarization has not been fully elucidated to date. In this study, we investigated the mechanism of choline uptake in microglia, and its association with microglial M1/M2 polarization. Methods: The immortalized mouse microglial cell line SIM-A9 was used for [3H]choline uptake and expression analysis of choline transporters. The association between the choline uptake system and the M1/M2 polarization of microglia was also analyzed. Results: Choline transporter-like protein (CTL) 1 and CTL2 were highly expressed in SIM-A9 cells, and CTL1 and CTL2 were localized in the plasma membrane and mitochondria, respectively. Functional analysis of choline uptake demonstrated the existence of Na+-independent, pH-dependent, and intermediate-affinity choline transport systems. Choline uptake was concentration-dependently inhibited by hemicholinium-3 (HC-3), an inhibitor of choline uptake, and increased by lipopolysaccharide (LPS) and interleukin-4 (IL-4). Expression of the mRNA of M1 microglia markers IL-1β and IL-6 was increased by LPS, and their effects were suppressed by choline deprivation and HC-3. In contrast, mRNA expression of the M2 microglial marker arginase-1 (Arg-1) was increased by IL-4, and the effect was enhanced by choline deprivation and HC-3. Conclusions: Our results suggest that inhibition of CTL1-mediated choline uptake in microglia preferentially induces M2 microglia polarization, which is a potential therapeutic approach for inflammatory brain diseases.

show abstract

Polymorphisms in SLC44A1 are associated with cognitive improvement in children diagnosed with fetal alcohol spectrum disorder: an exploratory study of oral choline supplementation

Smith

Virdee

Eckerle

et al. 2021

The American Journal of Clinical Nutrition

View full text Add to dashboard Cite

Background The essential nutrient choline provides one-carbon units for metabolite synthesis and epigenetic regulation in tissues including brain. Dietary choline intake is often inadequate, and higher intakes are associated with improved cognitive function. Objective Choline supplements confer cognitive improvement for those diagnosed with fetal alcohol spectrum disorder (FASD), a common set of neurodevelopmental impairments; however, the effect sizes have been modest. In this retrospective analysis, we report that genetic polymorphisms affecting choline utilization are associated with cognitive improvement following choline intervention. Methods Fifty-two children from the upper midwestern United States and diagnosed with FASD, ages 2–5 y, were randomly assigned to receive choline (500 mg/d; n = 26) or placebo (n = 26) for 9 mo, and were genotyped for 384 choline-related single nucleotide polymorphisms (SNPs). Memory and cognition were assessed at enrollment, study terminus, and at 4-y follow-up for a subset. Results When stratified by intervention (choline vs. placebo), 14–16 SNPs within the cellular choline transporter gene solute carrier family 44 member 1 (SLC44A1) were significantly associated with performance in an elicited imitation sequential memory task, wherein the effect alleles were associated with the greatest pre-/postintervention improvement. Of these, rs3199966 is a structural variant (S644A) and rs2771040 is a single-nucleotide variant within the 3′ untranslated region of the plasma membrane isoform. An additive genetic model best explained the genotype associations. Lesser associations were observed for cognitive outcome and polymorphisms in flavin monooxygenase-3 (FMO3), methylenetetrahydrofolate dehydrogenase-1 (MTHFD1), fatty acid desaturase-2 (FADS2), and adiponectin receptor 1 (ADIPOR1). Conclusions These SLC44A1 variants were previously associated with greater vulnerability to choline deficiency. Our data potentially support the use of choline supplements to improve cognitive function in individuals diagnosed with FASD who carry these effect alleles. Although these findings require replication in both retrospective and prospective confirmatory trials, they emphasize the need to incorporate similar genetic analyses of choline-related polymorphisms in other FASD-choline trials, and to test for similar associations within the general FASD population. This trial was registered at www.clinicaltrials.gov as NCT01149538.

show abstract

Protein kinase�C promotes choline transporter‑like protein�1 function via improved cell surface expression in immortalized human hepatic cells

Cited by 4 publications

References 41 publications

Functional Expression of Choline Transporters in Human Neural Stem Cells and Its Link to Cell Proliferation, Cell Viability, and Neurite Outgrowth

Functional Expression of Choline Transporters in Human Neural Stem Cells and Its Link to Cell Proliferation, Cell Viability, and Neurite Outgrowth

Functional Expression of Choline Transporters in Microglia and Their Regulation of Microglial M1/M2 Polarization

Polymorphisms in SLC44A1 are associated with cognitive improvement in children diagnosed with fetal alcohol spectrum disorder: an exploratory study of oral choline supplementation

Contact Info

Product

Resources

About