1.Establishing a Cre/loxP-based genetic manipulation system for Acanthamoeba: Targeted genome editing and stable reporter expression
Ja Moon AUNG ; So-Young JOO ; Byoung-Kuk NA ; Seunghyeok BANG ; Minsang SHIN ; Youn-Kyoung GOO ; Yeonchul HONG
Parasites, Hosts and Diseases 2025;63(1):25-36
Acanthamoeba is an opportunistic pathogen responsible for granulomatous amoebic encephalitis and amoebic keratitis. Despite its clinical significance, effective treatments remain challenging due to a limited understanding of its pathogenic mechanism. This study developed a genetic manipulation system in Acanthamoeba to facilitate gene function and drug screening studies. We applied the Cre/loxP system to integrate the gene encoding the tdTomato fluorescent protein into the genome of Acanthamoeba castellanii via homologous recombination. The polyubiquitin gene and its untranslated regions were identified and verified, after which the tdTomato gene was cloned between the untranslated regions of the polyubiquitin gene. The construct was then introduced into the Acanthamoeba genome using a modified pLPBLP vector containing loxP sites. Cre recombinase was utilized to remove the neomycin resistance cassette flanked by loxP sites, and genetically modified cells were selected by clonal dilution. The integration of the tdTomato gene, confirmed through PCR and fluorescence microscopy, showed stable expression in both trophozoites and cysts without the need for antibiotic selection. We demonstrated the feasibility of antibiotic-free reporter gene expression in Acanthamoeba. The system provides a valuable tool for functional genomics, allowing us to explore gene functions in Acanthamoeba and develop reliable drug screening models. Furthermore, the ability to express genes without the continuous use of selection markers opens up new possibilities for studying the pathobiology of this pathogen and advancing the development of novel therapeutic strategies against Acanthamoeba infections.
2.Establishing a Cre/loxP-based genetic manipulation system for Acanthamoeba: Targeted genome editing and stable reporter expression
Ja Moon AUNG ; So-Young JOO ; Byoung-Kuk NA ; Seunghyeok BANG ; Minsang SHIN ; Youn-Kyoung GOO ; Yeonchul HONG
Parasites, Hosts and Diseases 2025;63(1):25-36
Acanthamoeba is an opportunistic pathogen responsible for granulomatous amoebic encephalitis and amoebic keratitis. Despite its clinical significance, effective treatments remain challenging due to a limited understanding of its pathogenic mechanism. This study developed a genetic manipulation system in Acanthamoeba to facilitate gene function and drug screening studies. We applied the Cre/loxP system to integrate the gene encoding the tdTomato fluorescent protein into the genome of Acanthamoeba castellanii via homologous recombination. The polyubiquitin gene and its untranslated regions were identified and verified, after which the tdTomato gene was cloned between the untranslated regions of the polyubiquitin gene. The construct was then introduced into the Acanthamoeba genome using a modified pLPBLP vector containing loxP sites. Cre recombinase was utilized to remove the neomycin resistance cassette flanked by loxP sites, and genetically modified cells were selected by clonal dilution. The integration of the tdTomato gene, confirmed through PCR and fluorescence microscopy, showed stable expression in both trophozoites and cysts without the need for antibiotic selection. We demonstrated the feasibility of antibiotic-free reporter gene expression in Acanthamoeba. The system provides a valuable tool for functional genomics, allowing us to explore gene functions in Acanthamoeba and develop reliable drug screening models. Furthermore, the ability to express genes without the continuous use of selection markers opens up new possibilities for studying the pathobiology of this pathogen and advancing the development of novel therapeutic strategies against Acanthamoeba infections.
3.Establishing a Cre/loxP-based genetic manipulation system for Acanthamoeba: Targeted genome editing and stable reporter expression
Ja Moon AUNG ; So-Young JOO ; Byoung-Kuk NA ; Seunghyeok BANG ; Minsang SHIN ; Youn-Kyoung GOO ; Yeonchul HONG
Parasites, Hosts and Diseases 2025;63(1):25-36
Acanthamoeba is an opportunistic pathogen responsible for granulomatous amoebic encephalitis and amoebic keratitis. Despite its clinical significance, effective treatments remain challenging due to a limited understanding of its pathogenic mechanism. This study developed a genetic manipulation system in Acanthamoeba to facilitate gene function and drug screening studies. We applied the Cre/loxP system to integrate the gene encoding the tdTomato fluorescent protein into the genome of Acanthamoeba castellanii via homologous recombination. The polyubiquitin gene and its untranslated regions were identified and verified, after which the tdTomato gene was cloned between the untranslated regions of the polyubiquitin gene. The construct was then introduced into the Acanthamoeba genome using a modified pLPBLP vector containing loxP sites. Cre recombinase was utilized to remove the neomycin resistance cassette flanked by loxP sites, and genetically modified cells were selected by clonal dilution. The integration of the tdTomato gene, confirmed through PCR and fluorescence microscopy, showed stable expression in both trophozoites and cysts without the need for antibiotic selection. We demonstrated the feasibility of antibiotic-free reporter gene expression in Acanthamoeba. The system provides a valuable tool for functional genomics, allowing us to explore gene functions in Acanthamoeba and develop reliable drug screening models. Furthermore, the ability to express genes without the continuous use of selection markers opens up new possibilities for studying the pathobiology of this pathogen and advancing the development of novel therapeutic strategies against Acanthamoeba infections.
4.Clinical Efficacy of Rebamipide Eyedrops in Patients with Sjögren’s Syndrome Accompanied by Meibomian Gland Dysfunction
Hyo Ju JANG ; Ja Young MOON ; Hyeon Jeong YOON ; Kyung Chul YOON
Journal of the Korean Ophthalmological Society 2025;66(1):8-16
Purpose:
To investigate the clinical efficacy of rebamipide eyedrops in patients with meibomian gland dysfunction (MGD) associated with Sjögren’s syndrome.
Methods:
The study included 50 patients with Sjögren’s syndrome accompanied by MGD treated with 0.05% (w/v) cyclosporine and 0.15% (w/v) sodium hyaluronate eyedrops. They were divided into two groups: 25 who added rebamipide eyedrops to their existing treatments and a control group of 25 whose treatments did not change. We evaluated the tear breakup time, the Schirmer test and conjunctival staining scores, meibomian gland quality and function, and eyelid margin irregularity before prescribing rebamipide eyedrops and 1 and 3 months after prescription. Additionally, before eyedrops use and 3 months later, meibographic scores were assessed via imaging of the meibomian gland and ocular surface disease index values also were assessed.
Results:
The rebamipide group exhibited significant improvements in the tear breakup time, conjunctival staining score, and ocular surface disease index compared to before treatment (all p < 0.05). However, the Schirmer test result, meibomian gland quality and function, and eyelid margin irregularity did not differ between either groups before or after treatment. After 3 months of eyedrop use, the rebamipide group exhibited a significantly higher tear breakup time (p < 0.01) and Schirmer test score (p < 0.01) than the control group (p = 0.01), and significantly lower ocular surface disease index and conjunctival staining scores (p < 0.01).
Conclusions
Addition of rebamipide eyedrops to the conventional treatment of patients with Sjögren’s syndrome accompanied by MGD effectively improves dry eye symptoms and the ocular surface parameters.
5.Clinical Efficacy of Rebamipide Eyedrops in Patients with Sjögren’s Syndrome Accompanied by Meibomian Gland Dysfunction
Hyo Ju JANG ; Ja Young MOON ; Hyeon Jeong YOON ; Kyung Chul YOON
Journal of the Korean Ophthalmological Society 2025;66(1):8-16
Purpose:
To investigate the clinical efficacy of rebamipide eyedrops in patients with meibomian gland dysfunction (MGD) associated with Sjögren’s syndrome.
Methods:
The study included 50 patients with Sjögren’s syndrome accompanied by MGD treated with 0.05% (w/v) cyclosporine and 0.15% (w/v) sodium hyaluronate eyedrops. They were divided into two groups: 25 who added rebamipide eyedrops to their existing treatments and a control group of 25 whose treatments did not change. We evaluated the tear breakup time, the Schirmer test and conjunctival staining scores, meibomian gland quality and function, and eyelid margin irregularity before prescribing rebamipide eyedrops and 1 and 3 months after prescription. Additionally, before eyedrops use and 3 months later, meibographic scores were assessed via imaging of the meibomian gland and ocular surface disease index values also were assessed.
Results:
The rebamipide group exhibited significant improvements in the tear breakup time, conjunctival staining score, and ocular surface disease index compared to before treatment (all p < 0.05). However, the Schirmer test result, meibomian gland quality and function, and eyelid margin irregularity did not differ between either groups before or after treatment. After 3 months of eyedrop use, the rebamipide group exhibited a significantly higher tear breakup time (p < 0.01) and Schirmer test score (p < 0.01) than the control group (p = 0.01), and significantly lower ocular surface disease index and conjunctival staining scores (p < 0.01).
Conclusions
Addition of rebamipide eyedrops to the conventional treatment of patients with Sjögren’s syndrome accompanied by MGD effectively improves dry eye symptoms and the ocular surface parameters.
6.Establishing a Cre/loxP-based genetic manipulation system for Acanthamoeba: Targeted genome editing and stable reporter expression
Ja Moon AUNG ; So-Young JOO ; Byoung-Kuk NA ; Seunghyeok BANG ; Minsang SHIN ; Youn-Kyoung GOO ; Yeonchul HONG
Parasites, Hosts and Diseases 2025;63(1):25-36
Acanthamoeba is an opportunistic pathogen responsible for granulomatous amoebic encephalitis and amoebic keratitis. Despite its clinical significance, effective treatments remain challenging due to a limited understanding of its pathogenic mechanism. This study developed a genetic manipulation system in Acanthamoeba to facilitate gene function and drug screening studies. We applied the Cre/loxP system to integrate the gene encoding the tdTomato fluorescent protein into the genome of Acanthamoeba castellanii via homologous recombination. The polyubiquitin gene and its untranslated regions were identified and verified, after which the tdTomato gene was cloned between the untranslated regions of the polyubiquitin gene. The construct was then introduced into the Acanthamoeba genome using a modified pLPBLP vector containing loxP sites. Cre recombinase was utilized to remove the neomycin resistance cassette flanked by loxP sites, and genetically modified cells were selected by clonal dilution. The integration of the tdTomato gene, confirmed through PCR and fluorescence microscopy, showed stable expression in both trophozoites and cysts without the need for antibiotic selection. We demonstrated the feasibility of antibiotic-free reporter gene expression in Acanthamoeba. The system provides a valuable tool for functional genomics, allowing us to explore gene functions in Acanthamoeba and develop reliable drug screening models. Furthermore, the ability to express genes without the continuous use of selection markers opens up new possibilities for studying the pathobiology of this pathogen and advancing the development of novel therapeutic strategies against Acanthamoeba infections.
7.Clinical Efficacy of Rebamipide Eyedrops in Patients with Sjögren’s Syndrome Accompanied by Meibomian Gland Dysfunction
Hyo Ju JANG ; Ja Young MOON ; Hyeon Jeong YOON ; Kyung Chul YOON
Journal of the Korean Ophthalmological Society 2025;66(1):8-16
Purpose:
To investigate the clinical efficacy of rebamipide eyedrops in patients with meibomian gland dysfunction (MGD) associated with Sjögren’s syndrome.
Methods:
The study included 50 patients with Sjögren’s syndrome accompanied by MGD treated with 0.05% (w/v) cyclosporine and 0.15% (w/v) sodium hyaluronate eyedrops. They were divided into two groups: 25 who added rebamipide eyedrops to their existing treatments and a control group of 25 whose treatments did not change. We evaluated the tear breakup time, the Schirmer test and conjunctival staining scores, meibomian gland quality and function, and eyelid margin irregularity before prescribing rebamipide eyedrops and 1 and 3 months after prescription. Additionally, before eyedrops use and 3 months later, meibographic scores were assessed via imaging of the meibomian gland and ocular surface disease index values also were assessed.
Results:
The rebamipide group exhibited significant improvements in the tear breakup time, conjunctival staining score, and ocular surface disease index compared to before treatment (all p < 0.05). However, the Schirmer test result, meibomian gland quality and function, and eyelid margin irregularity did not differ between either groups before or after treatment. After 3 months of eyedrop use, the rebamipide group exhibited a significantly higher tear breakup time (p < 0.01) and Schirmer test score (p < 0.01) than the control group (p = 0.01), and significantly lower ocular surface disease index and conjunctival staining scores (p < 0.01).
Conclusions
Addition of rebamipide eyedrops to the conventional treatment of patients with Sjögren’s syndrome accompanied by MGD effectively improves dry eye symptoms and the ocular surface parameters.
8.Establishing a Cre/loxP-based genetic manipulation system for Acanthamoeba: Targeted genome editing and stable reporter expression
Ja Moon AUNG ; So-Young JOO ; Byoung-Kuk NA ; Seunghyeok BANG ; Minsang SHIN ; Youn-Kyoung GOO ; Yeonchul HONG
Parasites, Hosts and Diseases 2025;63(1):25-36
Acanthamoeba is an opportunistic pathogen responsible for granulomatous amoebic encephalitis and amoebic keratitis. Despite its clinical significance, effective treatments remain challenging due to a limited understanding of its pathogenic mechanism. This study developed a genetic manipulation system in Acanthamoeba to facilitate gene function and drug screening studies. We applied the Cre/loxP system to integrate the gene encoding the tdTomato fluorescent protein into the genome of Acanthamoeba castellanii via homologous recombination. The polyubiquitin gene and its untranslated regions were identified and verified, after which the tdTomato gene was cloned between the untranslated regions of the polyubiquitin gene. The construct was then introduced into the Acanthamoeba genome using a modified pLPBLP vector containing loxP sites. Cre recombinase was utilized to remove the neomycin resistance cassette flanked by loxP sites, and genetically modified cells were selected by clonal dilution. The integration of the tdTomato gene, confirmed through PCR and fluorescence microscopy, showed stable expression in both trophozoites and cysts without the need for antibiotic selection. We demonstrated the feasibility of antibiotic-free reporter gene expression in Acanthamoeba. The system provides a valuable tool for functional genomics, allowing us to explore gene functions in Acanthamoeba and develop reliable drug screening models. Furthermore, the ability to express genes without the continuous use of selection markers opens up new possibilities for studying the pathobiology of this pathogen and advancing the development of novel therapeutic strategies against Acanthamoeba infections.
9.Effects of Carbomer Eye Gels on the Ocular Surface in Dry Eye Patients
Jong Hoon LEE ; Ja Young MOON ; Hyeon-Jeong YOON ; Kyung Chul YOON
Journal of the Korean Ophthalmological Society 2024;65(1):9-15
Purpose:
We investigated the clinical effects of Siccafluid carbomer eye gel on the symptoms, tear film, and ocular surface in dry eye patients.
Methods:
Fifty-five patients with dry eye syndrome were also treated with carbomer eye gel for 6 months. The Dry Eye Questionnaire (DEQ-5), tear film breakup time (TBUT), Schirmer’s test, and ocular surface staining score were assessed during follow-up. Patients were classified into Sjögren’s syndrome and non-Sjögren’s syndrome groups and the effects of the carbomer eye drops in each group were analyzed.
Results:
Overall, the dry eye patients showed significant improvement in the total DEQ-5 score, frequency and intensity of dryness, and TBUT 6 months after treatment. In the non-Sjögren’s group, the total DEQ-5 score, intensity of dryness, and TBUT improved, while in the Sjögren’s group, the total DEQ-5 score, frequency and intensity of dryness, and TBUT improved. In both groups, patients with a shorter TBUT showed a significant improvement in the total DEQ-5 score.
Conclusions
After 6 months of carbomer eye gel use in patients with dry eye syndrome, the symptoms of ocular dryness and tear film breakup time improved. In patients with dry eye syndrome who have a short TBUT, this can be an effective treatment for alleviating dry eye symptoms.
10.Anti-inflammatory Activity and Modulation of Endoplasmic Reticulum Stress by the Hexane Fraction from the Roots of Peucedanum insolens Kitag
Jin-Ik KIM ; Yong-Won CHOI ; Nandintsetseg NARANTUYA ; In-Young LEE ; Ji-An KANG ; Sik-Jae CHO ; Ja-Young MOON
Natural Product Sciences 2024;30(3):167-174
In this study, the anti-inflammatory activity and ER stress modulation of the hexane fraction from Peucedanum insolens Kitag. root was investigated. The anti-inflammatory activity was evaluated by measuring nitric oxide inhibition and analyzing iNOS and COX-2 expression in LPS-treated RAW 264.7 macrophages using Western blot. The hexane fraction’s effect on ER stress was assessed by monitoring ATF6α transcriptional activity in the stable recombinant HLR-GV-hATF6α (333) cell line. Additionally, the expression levels of ER stress-related proteins, including eIF2α, p-eIF2α, GRP78, and CHOP, were analyzed by western blot in HeLa cells. Our results demonstrated that the hexane fraction strongly inhibited nitric oxide production and the expression of iNOS and COX-2 in LPS-treated RAW 264.7 cells. It also significantly reduced ATF6α transcriptional activation induced by thapsigargin or tunicamycin. In HeLa cells, the hexane fraction inhibited the expression of ER stress-related proteins GRP78 and CHOP induced by thapsigargin. Although the hexane fraction alone did not affect GRP78, CHOP and eIF2α levels, it enhanced eIF2α phosphorylation in a concentrationdependent manner. Co-treatment with the hexane extract and thapsigargin prevented both CHOP and GRP78 expressions and eIF2α phosphorylation. Taken together, our results suggest that the anti-inflammatory potency of the hexane-fraction of P. insolens might be related to its potential to modulate ER stress. To find out more detailed integrated actions of the hexanefraction of P. insolens against ER stress-induced inflammation signalling and to identify bioactive compound(s) associated with ERSR-related inflammation, further studies are required using a single cell type, such as RAW 264.7 or HeLa cells.

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