• 한국수정란이식학회지
• /
• 제33권2호
• /
• pp.85-97
• /
• 2018

The trans-differentiation potential of mesenchymal stem cells (MSCs) is employed, but there is little understanding of the cell source-dependent trans-differentiation potential of MSCs into corneal epithelial cells. In the present study, we induced trans-differentiation of MSCs derived from umbilical cord matrix (UCM-MSCs) and from dental tissue (D-MSCs), and we comparatively evaluated the in vitro trans-differentiation properties of both MSCs into corneal epithelial-like cells. Specific cell surface markers of MSC (CD44, CD73, CD90, and CD105) were detected in both UCM-MSCs and D-MSCs, but MHCII and CD119 were significantly lower (P < 0.05) in UCM-MSCs than in D-MSCs. In UCM-MSCs, not only expression levels of Oct3/4 and Nanog but also proliferation ability were significantly higher (P < 0.05) than in D-MSCs. In vitro differentiation abilities into adipocytes and osteocytes were confirmed for both MSCs. UCM-MSCs and D-MSCs were successfully trans-differentiated into corneal epithelial cells, and expression of lineage-specific markers (Cytokeratin-3, -8, and -12) were confirmed in both MSCs using immunofluorescence staining and qRT-PCR analysis. In particular, the differentiation capacity of UCM-MSCs into corneal epithelial cells was significantly higher (P < 0.05) than that of D-MSCs. In conclusion, UCM-MSCs have higher differentiation potential into corneal epithelial-like cells and have lower expression of CD119 and MHC class II than D-MSCs, which makes them a better source for the treatment of corneal opacity.

• 한국안광학회지
• /
• 제4권1호
• /
• pp.1-6
• /
• 1999

사람의 각막상피 세포를 배양하여 각막상피가 저절로 탈락해 나가는 과정을 이해하기 위해 무 혈청 배지에서 세포를 1주일 동안 배양하여 시간의 경과에 따른 세포의 소실과정을 조사하였다. 사람 각막상피 세포 주를 무 혈청 배지에서 배양하여 1, 2, 3, 6일에 세포의 형태적 관찰과 세포고사(Apoptosis) 정도를 측정하기 위해 Giemsa 염색, Hoechst 33342 형광 염색, 그리고 TUNEL(TdT-dUTP terminal nick-end labelling) assay를 시행하였다. 무 혈청 배지에서 세포를 배양하연 시간이 지남에 따라 세포의 모양이 변하였으며 망상의 세포 군집을 형성하였다. 많은 세포가 부유하여 작은 소체를 형성하였으며 세포고사 율은 3일 경과 후 50%를 나타냈다. 또한 TUNEL assay에 의해 단편화된 DNA도 관찰할 수 있었다. 본 연구의 결과는 영양 부족상태의 각막상피 세포가 세포고사를 거쳐 소모되고 탈락되는 것을 암시하고 있다.

• Parasites, Hosts and Diseases
• /
• 제54권6호
• /
• pp.697-702
• /
• 2016

Acanthamoeba keratitis has been increasing in recent years. Main risk factors are contact lens wear and their cleaning solutions. Most contact lens wearers use multipurpose disinfecting solutions (MPDS) for cleansing and disinfecting microorganisms because of its convenience. We determined amoebicidal effects of MPDS made in Korea and their cytotoxicity on human corneal epithelium cells. Fifteen commercial MPDS (A to O) were tested for their amoebicidal effects on Acanthamoeba castellanii trophozoites and cysts by using a most probable number (MPN) technique. Among them, 7 kinds of MPDS showed little or no amoebicidal effects for 24 hr exposure. Solutions A, B, G, H, L, and O showed positive amoebicidal effects, and solutions M and N killed almost all trophozoites and cysts after 24 hr exposure. However, 50%-N solution showed 56% cytotoxicity on human corneal epithelial cells within 4 hr exposure, and 50%-O solution also showed 62% cytotoxicity on human cells within 4 hr exposure. Solution A did not show any cytotoxicity on human cells. These results revealed that most MPDS made in Korea were ineffective to kill Acanthamoeba. The solutions having amoebicidal activity also showed high levels of cytotoxicity on human corneal epithelial cells. New formulations for improved MPDS that are amoebicidal but safe for host cells are needed to prevent Acanthamoeba keratitis.

• The Korean Journal of Physiology and Pharmacology
• /
• 제18권2호
• /
• pp.89-94
• /
• 2014

DA-6034, a eupatilin derivative of flavonoid, has shown potent effects on the protection of gastric mucosa and induced the increases in fluid and glycoprotein secretion in human and rat corneal and conjunctival cells, suggesting that it might be considered as a drug for the treatment of dry eye. However, whether DA-6034 induces $Ca^{2+}$ signaling and its underlying mechanism in epithelial cells are not known. In the present study, we investigated the mechanism for actions of DA-6034 in $Ca^{2+}$ signaling pathways of the epithelial cells (conjunctival and corneal cells) from human donor eyes and mouse salivary gland epithelial cells. DA-6034 activated $Ca^{2+}$-activated $Cl^-$ channels (CaCCs) and increased intracellular calcium concentrations ($[Ca^{2+}]_i$) in primary cultured human conjunctival cells. DA-6034 also increased $[Ca^{2+}]_i$ in mouse salivary gland cells and human corneal epithelial cells. $[Ca^{2+}]_i$ increase of DA-6034 was dependent on the $Ca^{2+}$ entry from extracellular and $Ca^{2+}$ release from internal $Ca^{2+}$ stores. Interestingly, these effects of DA-6034 were related to ryanodine receptors (RyRs) but not phospholipase C/inositol 1,4,5-triphosphate ($IP_3$) pathway and lysosomal $Ca^{2+}$ stores. These results suggest that DA-6034 induces $Ca^{2+}$ signaling via extracellular $Ca^{2+}$ entry and RyRs-sensitive $Ca^{2+}$ release from internal $Ca^{2+}$ stores in epithelial cells.

• The Korean Journal of Physiology and Pharmacology
• /
• 제21권2호
• /
• pp.189-195
• /
• 2017

This study aimed to compare the cellular toxicities of three clinically used dry eye treatments; 3% diquafosol tetrasodium and hyaluronic acid at 0.3 and 0.18%. A methyl thiazolyltetrazoiun (MTT)-based calorimetric assay was used to assess cellular proliferation and a lactate dehydrogenase (LDH) leakage assay to assess cytotoxicity, using Human corneal epithelial cells (HCECs) exposed to 3% diquafosol tetrasodium, 0.3% hyaluronic acid (HA), or 0.18% HA or 1, 6 or 24 h. Cellular morphology was evaluated by inverted phase-contrast light microscopy and electron microscopy, and wound widths were measured 24 h after confluent HCECs were scratched. Diquafosol had a significant, time-dependent, inhibitory effect on HCEC proliferation and cytotoxicity. HCECs treated with diquafosol detached more from the bottoms of dishes and damaged cells showed degenerative changes, such as, reduced numbers of microvilli, vacuole formation, and chromatin of the nuclear remnant condensed along the nuclear periphery. All significantly stimulated reepithelialization of HCECs scratched, which were less observed in diquafosol. Therefore, epithelial toxicity should be considered after long-term usage of diquafosol and in overdose cases, especially in dry eye patients with pre-existing punctated epithelial erosion.

• 한국안광학회지
• /
• 제8권1호
• /
• pp.65-71
• /
• 2003

각막 상피세포는 정상적인 apoptosis과정을 거쳐 세포가 탈락하고 재생한다. 이러한 apoptosis에는 많은 요소들이 관여하여 세포가 사멸하는데 여러 가지 메커니즘이 관여한다. 본 연구에서는 세포고사 인자로 알려진 물질들을 각막 상피세포에서 apoptosis의 유도 여부를 다른 세포와 비교하여 각막 상피세포의 특성을 알아보고자 시행하였다. 본 연구에 이용된 세포고사 유도물질은 recombinant human cytokiness ($INF{\gamma}$, $TNF{\alpha}$, FASAb), actinomycin D. camptothecin, cycloheximide, dexamethasone와 etoposide이다. 이들을 세포에 48시간 처리한 후 세포독성을 MTT assay로 측정하였으며 세포고사는 Hoechst 33342 staining. Annexin V-FITC/PI staining 그리고 DePsipher assay를 이용하였다. 세포고사의 한 경로인 FAS-FAS ligand system에 대한 연구는 immunocytochemistry로 Fas protein 발현 여부를 조사하였다. 모든 유도인자는 농도의존적으로 세포고사를 유도하였는데 Actinomycin D. camptothecin와 etoposide는 제조사의 추천 농도보다 낮은 농도에서 세포고사가 유도되었고 반면에 cytokines, cycloheximide, dexamethasone은 더 높은 농도에서 세포고사를 유도하였다. FAS antigen은 대조군과 처리군 모두에서 발현되었으나 세포고사율에 비례하여 높게 발현되었다. 본 연구 결과 각막 상피세포는 RNA synthesis inhibitor와 topoisomerase inhibitors가 intracellular receptor-activators 보다 세포고사에 민감하게 나타나는 세포의 특성을 보였다.

• Parasites, Hosts and Diseases
• /
• 제57권3호
• /
• pp.217-223
• /
• 2019

Acanthamoeba castellanii has ubiquitous distribution and causes primary acanthamoebic keratitis (AK). AK is a common disease in contact lens wearers and results in permanent visual impairment or blindness. In this study, we observed the cytopathic effect, in vitro cytotoxicity, and secretion pattern of cytokines in human corneal epithelial cells (HCECs) induced by A. castellanii trophozoites and/or cysts. Morphological observation revealed that panked dendritic HCECs co-cultured with amoeba cysts had changed into round shape and gradually died. Such changes were more severe in co-culture with cyst than those of co-cultivation with trophozoites. In vitro cytotoxicity assay revealed the highest cytotoxicity to HCECs in the co-culture system with amoeba cysts. A. castellanii induced the expression of $IL-1{\alpha}$, IL-6, IL-8, and CXCL1 in HCECs. Secreted levels of $IL-1{\alpha}$, IL-6, and IL-8 in HCECs co-cultured with both trophozoites and cysts were increased at an early incubation time (3 and 6 hr). These results suggested that cytopathic changes and pro-inflammatory cytokines release of HCECs in response to A. castellanii, especially amoebic cysts, are an important mechanism for AK development.

• 대한시과학회지
• /
• 제20권4호
• /
• pp.531-541
• /
• 2018

목적 : 항균제 polyhexamethylene Biguanide(PHMB), epigallocatechin gallate(EGCG) 및 PHMB/EGCG 혼합물의 각막상피세포(primary human corneal epithelial cells, HCEpiCs)에 대한 급성독성을 평가하고자 하였다. 방법 : 각막상피세포를 0.00001~0.005% PHMB, 0.001~5% EGCG 및 0.00005% PHMB/0.05% EGCG 혼합물이 각각 포함된 배양액에서 30분, 60분, 120분 및 240분 동안 배양하였다. 배양한 각막상피세포를 고정한 다음 Draq 5로 염색하고 공초점현미경과 ImageXpress $Ultra^{TM}$를 이용하여 세포형태를 관찰하여 세포생존율과 세포자살(apoptosis)을 비교하였다. 결과 : 배양된 각막상피세포는 0.00005% 이하의 PHMB 농도 및 0.05% 이하의 EGCG 농도에서는 세포 독성이 나타나지 않았다. 0.00005% PHMB/0.05% EGCG 혼합물이 포함된 배양액에서 급성 세포독성은 관찰되지 않았으나 240분 배양시킨 경우에는 손상된 각막상피세포 수가 증가하고 생존 세포의 수는 감소하였다. 결론 : 항균 시너지 효과를 갖는다고 보고된 0.00005% PHMB/0.05% EGCG 혼합물의 경우 각막상피세포에 대한 급성독성은 없었으나 만성효과에 대해서는 추가적인 연구가 필요할 것으로 생각된다.

• 한국안광학회지
• /
• 제5권1호
• /
• pp.83-87
• /
• 2000

본 연구는 각막상피가 저절로 탈락해 나가는 과정을 이해하기 위해 사람의 각막상피 세포를 배양하여 배지의 영양이 고갈될 때까지 약 7일 정도 배지를 교환하지 않고 계속 배양하여 세포고사를 조사하였다. 영양이 고갈된 배지인 Exhausted Medium을 여과하여 새로운 각막 상피세포에 넣어 2일 정도 배양을 계속하였다. Exhausted Medium에서 배양된 세포를 수확하여 세포고사를 검정하기 위해 Agarose gel electrophoresis로 DNA 단편을 확인하고 세포고사를 초기에 감지할 수 있는 방법인 M30 $CytoDEATH^*$. Fluorescein으로 확인하였다. 또한 Exhausted Medium에 의한 세포고사의 유발 경로를 조사하기 위해 사이토카인에 의한 유도인자 중 가장 많이 알려진 FAS나 FAS Ligand에 의한 유발여부를 soluble FAS and FAS Ligand에 대한 sandwich ELISA로 조사하였다. 그 결과 전형적인 DNA Ladder패턴을 보였으며 M30 $CytoDEATH^*$. Fluorescein에도 선명하게 염색되어 세포고사를 확인할 수 있었다. 또한 soluble FAS and FAS Ligand ELISA Kit로 Exhausted Medium이 FAS와 관련이 있는지를 조사한 결과 거의 무관한 것으로 나타났다. 본 연구의 결과는 영양 부족상태의 배지는 각막상피 세포가 세포고사를 거쳐 소모되는데 FAS and FAS Ligand system과는 무관한 것으로 나타났다.

• Biomolecules & Therapeutics
• /
• 제23권4호
• /
• pp.379-385
• /
• 2015

The eye irritation potential of drug candidates or pharmaceutical ingredients should be evaluated if there is a possibility of ocular exposure. Traditionally, the ocular irritation has been evaluated by the rabbit Draize test. However, rabbit eyes are more sensitive to irritants than human eyes, therefore substantial level of false positives are unavoidable. To resolve this species difference, several three-dimensional human corneal epithelial (HCE) models have been developed as alternative eye irritation test methods. Recently, we introduced a new HCE model, MCTT HCE$^{TM}$ which is reconstructed with non-transformed human corneal cells from limbal tissues. Here, we examined if MCTT HCE$^{TM}$ can be employed to evaluate eye irritation potential of solid substances. Through optimization of washing method and exposure time, treatment time was established as 10 min and washing procedure was set up as 4 times of washing with 10 mL of PBS and shaking in 30 mL of PBS in a beaker. With the established eye irritation test protocol, 11 solid substances (5 non-irritants, 6 irritants) were evaluated which demonstrated an excellent predictive capacity (100% accuracy, 100% specificity and 100% sensitivity). We also compared the performance of our test method with rabbit Draize test results and in vitro cytotoxicity test with 2D human corneal epithelial cell lines.