Folic Acid Alleviates Diet-induced Fatty Liver Injury via Regulation of Sulfur Amino Acid Metabolism and Cellular Stress-responsive Pathways

Song, Ji Yeon 부산대학교 대학원 2026 국내석사

Folic acid, a water-soluble B vitamin, plays a critical role in maintaining liver health by participating in one-carbon metabolism, DNA synthesis, and methylation reactions. Although recent studies suggest that folic acid improves fatty liver, its underlying mechanisms remain poorly understood. To clarify its protective role in vivo, a mouse model of diet-induced fatty liver injury was established using a high-fat methionine-defined and choline-deficient (HFMCD) diet. Male ICR mice were fed the HFMCD diet for 10 days and orally administered folic acid (2 or 10 mg/kg). Folic acid supplementation restored hepatic methionine and glutathione levels, thereby normalizing sulfur amino acid metabolism and promoting both structural and functional recovery of the liver. In a supporting in vitro experiment, treatment of HepG2 cells with folic acid significantly and dose-dependently reduced intracellular lipid accumulation induced by free fatty acids (FFA), confirming its lipid-lowering effect at the cellular level. Mechanistically, folic acid reactivated autophagy through modulation of sequestosome-1 (p62) and the mammalian target of rapamycin (mTOR), while attenuating ferroptosis by regulating ferritin heavy chain 1 (FTH1) and heme oxygenase 1 (HMOX1). Collectively, these findings demonstrate that folic acid ameliorates diet-induced fatty liver injury by rebalancing sulfur amino acid metabolism and alleviating cellular stress-responsive pathways, thereby promoting hepatocyte survival and maintaining hepatic metabolic homeostasis. 엽산은 단일 탄소 대사, DNA 합성, 메틸화 반응에 참여하여 간 건강을 유지하는 데 중요한역할을 한다. 최근 연구에 따르면 엽산이 지방간을 개선한다는 사실이 밝혀졌지만, 엽산의근본적인 메커니즘은 아직 잘 알려져 있지 않다. 생체 내 보호 역할을 명확히 하기 위해 고지방메티오닌 제한 및 콜린 결핍 (HFMCD) 식이를 사용하여 식이 유발 지방간 손상에 대한 마우스모델을 확립하였다. 수컷 ICR 마우스에게 10 일 동안 HFMCD 식이를 공급하고 엽산 (2 또는 10 mg/kg)을 경구 투여하였다. 엽산의 공급은 간 메티오닌과 글루타티온 수치를 회복시켜 황아미노산 대사를 정상화하고 간의 구조적 및 기능적 회복을 촉진하였다. 이를 뒷받침하는 in vitro 실험에서, 유리 지방산 (FFA)에 의해 유도된 세포 내 지질 축적 상태에서 엽산을 처리한 결과, 세포 수준에서 지질의 축적이 현저히 감소하는 것을 확인하였다. 메커니즘적으로 엽산은세퀘스토좀-1 (p62)과 포유류 라파마이신 표적 (mTOR)의 조절을 통해 자가포식을 재활성화하는한편, 페리틴 중쇄 1 (FTH1)와 헴 산화효소 1 (HMOX1)을 조절하여 페롭토시스를 완화하였다. 종합적으로, 엽산은 황 아미노산 대사 균형을 재조정하고 세포 스트레스 반응 경로를 완화하며식이 유발 지방간 손상을 개선하여 간세포 생존을 촉진하고 간 대사 항상성을 유지함을입증하였다.

Folic acid와 Ascorbic acid가 diphenylhydantoin에 의한 치은증식에 미치는 영향에 관한 실험적 연구

박일해 경희대학교 1989 국내박사

Preterm premature rupture of membrane (PROM) model and the regenerative effect of folic acid on amniotic membrane

Bit Na Park 고려대학교 의학전문대학원 2015 국내석사

Abstract Objective To examine the effects of nicotine and folic acid on amniotic regeneration in an in-vitro PROM model. Methods Human Amniotic Epithelial Stem Cells (hAESCs) were isolated from the human amniotic membrane and Human Amnion Tissue Cells (hATCs) were derived from the amnion tissue membrane. Both cell groups were prepared and characterized by flow cytometry. The effects of nicotine and folic acid on cell viability at different concentration levels were examined. In addition, the protective effect of folic acid on nicotine was also studied. Results Stem cell markers such as OCT-3/4, SSEA-4, SOX-2, Nanog were strongly expressed in hAESCs but only weakly expressed in hATCs. In addition, CD19 and CD34 were negative but CD73, CD90, and CD105 were positive in both cell groups. hAESCs showed a strong expression of CD324 whereas it barely expressed CD349. However, hATCs remained a high expression of CD349 with a weak level of CD324. Nicotine treatment significantly decreased the cell viabilities with the ranges from 2 mM to 5 mM (p<0.01) for hAESCs and from 3 mM to 5 mM (p<0.05) for hATCs. When applying folic acid on hAESCs, the cell viability increased significantly at a concentration of 100 nM (p<0.05), but it had no such effect on hATCs. Moreover, hAESCs treated with folic acid showed a protective result on nicotine treatment at the concentration of 100 nM of folic acid (p<0.05). Likewise, the similar pattern appeared in hATCs with the concentration of 100 nM of folic acid (p<0.05). Conclusion hAESCs and hATCs isolated and cultured from amniotic membrane showed similar characteristics except for slight differences in expression levels of OCT- 3/4, SSEA-4, SOX-2, Nanog. Cell viabilities significantly decreased with nicotine treatment in both cell groups, but decreased less with co-incubation with folic acid. Therefore, we found that folic acid has regenerative and protective effects on amniotic membrane.

The protective effect of folic acid in human amniotic epithelial stem cells using a new reproductive toxicity test

한송이 고려대학교 대학원 2015 국내박사

The amnion arises from the inner cell mass of blastocyst; therefore, its embryological origin is similar to that of the human foetus, and it has similar potential to differentiate into all three germ layers. Human-derived amniotic epithelial stem cells (hAESCs) are rich in amnion, but unlike embryonic stem cells, they are not associated with the ethical issues that have impeded stem cell research. We performed lamotrigine cytotoxicity tests with AESCs and developmental neurotoxicity tests during spontaneous differentiation of hAESCs to neuronal cells in order to measure cytotoxicity and confirm the protective effect of folic acid. The hAESCs isolated from amnion tissue were characterized by flow cytometry. Lamotrigine cytotoxicity was measured at concentrations of 10 μM, 50 μM, 100 μM, 500 μM, and 1000 μM; folic acid was added at 10 nM, 100 nM, and 1000 nM and cell viability was measured 1, 2, and 3 days after the treatment. MTT assays were used to measure the protective effect of folic acid in cells treated with lamotrigine. During neuronal differentiation of AESCs, lamotrigine and folic acid were added and the cells were evaluated for neurotoxicity and neuroprotection by folic acid. The hAESCs were positive for CD73, CD90, CD105, CD324, SSEA-4, SOX-2, OCT-3/4, and Nanog; they were negative for CD19, CD34, and CD349. The cytotoxicity assay showed that cell survival significantly reduced at 500μM and 1000 μM lamotrigine. Pre-treatment with 10–100 nM folic acid showed maximal protective effect. With 500 μM lamotrigine, neuronal differentiation reduced by ~30%. Early supplementation with folic acid (10 nM) did not improve neuronal differentiation. These results suggest that hAESCs could be used to evaluate reproductive toxicity in vitro.

생체내 급성 신 손상의 진행에 대한 신세뇨관 인간 CD36 과발현의 효과연구

정종환 전북대학교 일반대학원 2017 국내박사

급성 신 손상은 만성콩팥병의 진행에 있어서 잘 알려진 위험인자이며 급성 신 손상의 무증상 징후 조차도 만성콩팥병으로의 진행을 촉진시킬 수 있다. 기존의 신장질환, 고혈당, 비만, 고혈압 및 만성 염증과 같은 위험요소는 급성 신 손상의 만성콩팥병로의 이행 증가와 밀접한 연관관계를 보인다. 하지만 급성 신 손상의 만성콩팥병으로의 이행의 구체적인 과정에 대해서는 아직까지 명확하게 밝혀지지 않았다. 본 연구는 생체내 엽산 유인성 인간 CD36의 과발현이 급성 신 손상에 미치는 효과를 확인하고자 하였다. 근위 신세뇨관에만 특이하게 인간 CD36이 과발현되는 Pax8-rtTA/tetracycline response element-hCD36 (TRE-hCD36) 형질 전환 (Tg) 생쥐모델이 엽산 유도성 급성 신 손상에서 인간 CD36 과발현의 영향을 확인하기 위해서 사용되었다. 엽산 투여 후 48시간 뒤에 신장을 제거하였다. 조직 및 알부민 뇨 분석에서 엽산 유인성 Tg 군에서 신 세뇨관의 확장과 원주의 형성 그리고 알부민 뇨가 엽산 유인성 wild type (WT) 군에 비해서 더 심하고 증가하였다. 또한, CD68, monocyte chemoattractant protein-1 (Mcp-1)과 같은 염증 표지자 들과 collagen1a1 (Col1a1), collagen3a1 (Col3a1) 같은 섬유화 표지자 들 그리고 apoptotic protease activating factor 1 (Apaf1), B-cell lymphoma 2 associated X/B-cell lymphoma 2 (Bax/Bcl2) 같은 세포사 표지자들의 mRNA를 각각 엽산 유인성 Tg 군 과 엽산 유인성 WT 군에서 비교 분석하였다. Col3a1 의 mRNA이 엽산 유인성 Tg 군에서 엽산 유인성 WT 군에 비해 통계적으로 유의하게 증가하는 경향을 보였다 (p <0.01). 결론적으로 인간 CD36 과발현 생쥐에게 엽산 유인성 급성 신 손상의 조건이 가해졌을 경우 보다 심한 신 손상의 병리학적 소견들과 알부민뇨의 증가 소견을 보였다. 또한 Col3a1의 mRNA 분석은 엽산 유인성 Tg 군에서 엽산 유인성 WT 군에 비해 유의하게 증가하였다. 이를 통해 인간 CD36 과발현은 급성 신 손상의 진행을 일으킬 수 있는 잠재적인 위험인자이며 급성 신 손상의 악화 인자로 생각할 수 있다. 이러한 결과는 추후 보다 넓은 분자생물학적인 연구를 통해서 급성 신 손상의 진행과 관련된 인간 CD36의 역할이 명확히 규명된다면 보다 강력한 근거를 얻을 것이다. Acute kidney injury (AKI) is well-known risk factor for progression to chronic kidney disease, and even subclinical episodes of AKI also progress to chronic kidney disease (CKD). Several risk factors such as preexisting kidney disease, hyperglycemia, obesity, hypertension, and chronic inflammation may be associated with increased incidence to CKD after AKI. However, it is not known well how AKI progresses to CKD. This study was performed to identify the effect for AKI progression of human CD36-overexpression induced by folic- acid administration in vivo. Pax8-rtTA/tetracycline response element-human CD36 transgenic mice with proximal tubule-specific inducible expression of human CD36 were used to elucidate effect of human CD36-overexpression in folic acid induced AKI. Kidneys were removed 48 hours after folic acid administration. On histologic and analyses for albuminuria, there were more severe dilated tubules with cast and albuminuria which is well-known indicator of CKD progression in folic acid-treated transgenic mice compared with folic acid-treated wild type mice. In addition, comparative analysis of mRNA transcripts of inflammatory markers, such as CD68 and monocyte chemoattractant protein-1 (Mcp1), fibrosis markers, such as Collagen1a1 (Col1a1) and collagen 3a1 (Col3a1), and apoptosis markers, such as apoptotic protease activating factor 1 (Apaf1) and B-cell lymphoma 2 associated X/B-cell lymphoma 2 (Bax/Bcl2) were performed between folic acid-treated transgenic and folic acid-treated wild type mice. mRNA transcripts of Col3a1 was increased significantly in folic acid-treated transgenic mice compared with folic acid-treated wild type mice (p <0.01). In conclusion, more severe pathological findings and albuminuria are shown in human CD36-overexpressed mice compared with wild type mice in this experiment. Also, a significantly increased mRNA expression of Col3a1 is shown in folic acid-treated transgenic mice compared with folic acid-treated wild type mice. The results suggest that human CD36-overexpression may be a vulnerable factor of AKI and be potential risk factor of progression of AKI, and the results may have more strongly relevant evidences through further molecular works.

엽산 강화식품과 영양교육에 의한 가임기 여성의 엽산 영양상태 및 행동수행력 개선 효과

김민지 충북대학교 2015 국내석사

The purpose of the study was to evaluate the effects of folic acid-fortified food and nutrition education on folate nutritional status and behavioral capability of Korean women of child-bearing age. Fortified food was developed in a form of instant rice in a cup containing approximately 400 ㎍ of folic acid per serving. One hundred seventeen women aged between 19 and 35 were recruited in May, 2014, and 39 women who were diagnosed as low risk of folate deficiency by a screening tool or unable to participate in the survey at the predetermined date were excluded. Seventy-eight subjects were randomly assigned to one of four groups; ‘non-fortified food group', ‘fortified food group', ‘non-fortified food and nutrition education group' and ‘fortified food and nutrition education group'. The subjects were asked to eat blindly assigned food (fortified or non-fortified) once a day for 4 weeks in June, 2014. Nutrition education based on social cognitive theory was carried out once a week during the same period. The first session was face-to-face education, and the other three sessions were done through the website. Questionnaire survey, anthropometric examination, and hematological analysis were performed both at the baseline and at the end of the program. The variables of social cognitive theory including outcome expectations and behavioral capability score increased significantly in the nutrition education groups after the program. Serum and red blood cell (RBC) folate concentrations increased significantly and serum homocysteine concentrations decreased significantly in the fortified food groups after the program. In addition, the deficient rates of serum folate or RBC folate decreased significantly in the fortified food groups. Our results suggest that our nutrition education program has an impact on the various factors related to behavior change, and folic acid-fortified food is effective in improving folate nutritional status even after short-term supplementation. Thus, we need to develop a variety of folic acid-fortified foods to create a supportive environment where women of child-bearing age can easily consume folic acid, and implement nutrition education or campaigns in order to arouse the interest of folic acid of women of child-bearing age.

Antibody-drug conjugation 을 위한 glucuronic acid의 amide 유도체 연구

신원섭 세종대학교 대학원 2012 국내석사

논문요약 Antibody-drug conjugation 을 위한 Glucuronic acid의 amide 유도체 연구 β-Glucuronide linker는 amine을 포함하는 cytotoxic agents를 운반하기 위해antibody-drug conjugates(ADCs)에 사용 되어왔다. Linker는 혈장의 순환에서 안정하고 hydrophilic 하며 in vitro와 in vivo에서 높은 활성을 가지는 ADC를 제공한다. β-D-Glucuronidase는 β-D-Glucuronic acid를 인식하여 아주 빠르게 cleavage하는 것으로 알려져 있다. β-D-Glucuronic acid 에 항체와 drug를 연결하면 prodrug의 세포 독성이 매우 감소함은 물론이고 암세포에 있는 β-D-Glucuronidase를 만나기 전까지는 아주 안정한 형태로 있다. 이렇게 안정한 형태로 암세포까지 전달을 하고 암세포로 uptake되면 β-D-Glucuronidase에 의해서 drug가 release되고 암세포를 죽일 수 있다. ADC는 암세포로 receptor mediate endocytosis를 통하여 uptake된다. 암세포 표면에 많이 발현되어있는 receptor인 Folate receptor를 이용하여 uptake되는 메커니즘을 알아보고 ADC를 설계 하고자 한다. 주제어 : Antibody drug conjugate , Glucuronide linker , Folic acid conjugate , Drug delivery system , β-D-Glucuronidase

동위원소희석 액체크로마토그래피 질량분석법을 이용한 유아 분유 중 엽산 분석에 대한 연구

정민영 연세대학교 대학원 2006 국내석사

An isotope dilution-liquid chromatography/mass spectrometric method was developed as a candidate reference method for the accurate determination of folic acid in infant milk formula. Sample was spiked with 13C5-folic acid and then extracted with phosphate buffer (pH 6) solution. The extract was further cleaned up with deproteinization followed by a C18 solid-phase extraction cartridge. The extract was analyzed by using LC/ESI/MS on positive ion mode with selectively monitoring [M+H]+ions of the analyte and its isotope analogue at m/z 442 and m/z 447, respectively, and was also analyzed by using LC/ESI/MS/MS with selectively monitoring the collisionally induced dissociation channels of m/z 442 -> m/z 295 and m/z 447 ->295. The LC/MS/MS chromatogram showed substantially reduced background chemical noise compared to the LC/MS chromatogram. An repeatability and reproducibility study showed that the LC/MS/MS method is a reliable and reproducible method providing less than 1.5 relative percentage of method precision while the LC/MS results can be interfered by chemical interferences. 엽산은 세포 대사의 정상적인 진행을 위해 반드시 필요한 영양소이다. 신생아가 먹는 유아식이나 분유에도 엽산이 필수적으로 포함되어 있는데, 한 번 제조되면 그대로 신생아에게 공급되기 때문에 이러한 영양소들의 함량을 인증된 분석법으로 분석해서 검증하는 것이 필요하다. 따라서 본 연구에서는 분유 중의 엽산의 LC/MS 및 LC/MS/MS 분석을 위한 적절한 전처리법을 확립하고 이를 바탕으로 동위원소희석 질량분석법을 적용하여 식품 중 엽산 분석의 기준 분석법으로 활용되도록 하고자 한다.NIST가 보급하는 분유 인증 표준물(NIST SRM 1846)과 시중에 판매되고 있는 유아분유를 대상으로 엽산을 분석하였고, 내부 표준물질로 13C5-folic acid을 사용하였다. 인산칼륨 용액(pH 6)으로 추출한 후, C18 고체상 카트리지를 이용한 전처리법을 확립하였다. 추출물은 m/z 442 -> 295와 m/z 447 ->295인 충돌유도분해 채널을 선택적으로 모니터링 하게 되는 LC/ESI/MS/MS로 분석되었다. LC/MS/MS법의 크로마토그램은 LC/MS법의 크로마토그램보다 바탕선의 noise의 영향이 현저히 줄어드는 것을 보여주었고 1.5 %의 상대 표준 불확도를 나타내었다.

Decreased urinary secretion of belotecan in folic acid-induced acute renal failure rats due to down-regulation of Oat1 and Bcrp

Jin, Qingri 서울大學校 大學院 2009 국내박사

Vitamin A의 催奇形性에 미치는 Ethanol 및 Riboflavin, pyridoxine, folic acid의 影響

조대현 成均館大學校 1988 국내박사