Corneal stem/progenitor cells are typical adult stem/progenitor cells.The human cornea covers the front of the eyeball,which protects the eye from the outside environment while allowing vision.The location and functio...Corneal stem/progenitor cells are typical adult stem/progenitor cells.The human cornea covers the front of the eyeball,which protects the eye from the outside environment while allowing vision.The location and function demand the cornea to maintain its transparency and to continuously renew its epithelial surface by replacing injured or aged cells through a rapid turnover process in which corneal stem/progenitor cells play an important role.Corneal stem/progenitor cells include mainly corneal epithelial stem cells,corneal endothelial cell progenitors and corneal stromal stem cells.Since the discovery of corneal epithelial stem cells(also known as limbal stem cells)in 1971,an increasing number of markers for corneal stem/progenitor cells have been proposed,but there is no consensus regarding the definitive markers for them.Therefore,the identification,isolation and cultivation of these cells remain challenging without a unified approach.In this review,we systematically introduce the profile of biological characterizations,such as anatomy,characteristics,isolation,cultivation and molecular markers,and clinical applications of the three categories of corneal stem/progenitor cells.展开更多
Major advances are currently being made in regenerative medicine for cornea. Stem cell-based therapies represent a novel strategy that may substitute conventional corneal transplantation, albeit there aremany challeng...Major advances are currently being made in regenerative medicine for cornea. Stem cell-based therapies represent a novel strategy that may substitute conventional corneal transplantation, albeit there aremany challenges ahead given the singularities of each cellular layer of the cornea. This review recapitulates the current data on corneal epithelial stem cells, corneal stromal stem cells and corneal endothelial cell progenitors. Corneal limbal autografts containing epithelial stem cells have been transplanted in humans for more than 20 years with great successful rates, and researchers now focus on ex vivo cultures and other cell lineages to transplant to the ocular surface. A small population of cells in the corneal endothelium was recently reported to have self-renewal capacity, although they do not proliferate in vivo. Two main obstacles have hindered endothelial cell transplantation to date: culture protocols and cell delivery methods to the posterior cornea in vivo. Human corneal stromal stem cells have been identified shortly after the recognition of precursors of endothelial cells. Stromal stem cells may have the potential to provide a direct cell-based therapeutic approach when injected to corneal scars. Furthermore, they exhibit the ability to deposit organized connective tissue in vitro and may be useful in corneal stroma engineering in the future. Recent advances and future perspectives in the field are discussed.展开更多
Much of our understanding of the events which underlie cell migration has been derived from studies of cells intissue culture. One of the components that mediates this process is the dynamic actin-based microfilament ...Much of our understanding of the events which underlie cell migration has been derived from studies of cells intissue culture. One of the components that mediates this process is the dynamic actin-based microfilament system that canreorganize itself into so-called stress fibers that are considered essential components for cell motility. In contrast, relativelyfew studies have investigated cell movement along an extracellular matrix (ECM) which is known to influence both cellularorganization and behavior. This opinion/viewpoint article briefly reviews cell migration during corneal endothelial woundrepair along the tissue’s natural basement membrane, Descemet’s membrane. Because the tissue exists as a cell monolayer itaffords one an opportunity to readily explore the effect of cell/matrix influences on cell motility. As such, cell movementalong this substrate differs somewhat from that found in vitro and migrating endothelial cells also demonstrate an abilityto move along the ECM without the benefit of having an organized actin cytoskeleton.展开更多
AIM： To compare intraoperative phacoemulsification parameters and its effect on the corneal endothelium of eyes undergoing femtosecond laser-assisted cataract surgery（FLACS） versus conventional phacoemulsification...AIM： To compare intraoperative phacoemulsification parameters and its effect on the corneal endothelium of eyes undergoing femtosecond laser-assisted cataract surgery（FLACS） versus conventional phacoemulsification（CP） cataract surgery.METHODS： Two hundred eyes from one hundred patients were included in a prospective, non-blinded, randomized, controlled, intraindividual clinical study. One hundred eyes underwent FLACS while their one hundred fellow eyes underwent CP. All surgeries were performed using the Victus？ femtosecond laser platform and Infinity？ Vision System phacoemulsification machine. Primary outcome measure was endothelial cell density 6 mo after surgery. Secondary outcome measures included central corneal thickness（CCT）, average cell area, standard deviation, coefficient of variation and hexagonality before surgery and 6 mo after surgery and endothelial cell density loss during this period were also evaluated. Intraoperative efficiency parameters [cumulative dissipated energy（CDE）, total intraocular surgery time, total ultrasound time, total phacoemulsification time, total torsional energy time, total aspiration time, ultrasound energy, torsional amplitude and fluid required during surgery] were also collated. RESULTS： Data from these patients was not considered for analysis. Data from 92 patients were analysed. Postoperative endothelial cell density（cells/mm2） between groups（2211.88±392.49 CP; 2246.31±403.48 FLACS） was not statistically significant（P=0.869）. Total ultrasound time, torsional energy time, CDE and fluid requirements were significantly lower the FLACS group（P〈0.05）. Other parameters did not show statistically significant difference between FLACS and CP.CONCLUSION： FLACS displays significant improvements in phacoemulsification parameters in comparison to CP. There are no significant differences in corneal endothelium measures between FLACS and CP.展开更多
The examination of the effects of second generation lotra filcon B silicone hydrogel(SiH)lenses on the cornea when worn for three years of daily wear.Material and Methods:55 healthy patients were divided into two grou...The examination of the effects of second generation lotra filcon B silicone hydrogel(SiH)lenses on the cornea when worn for three years of daily wear.Material and Methods:55 healthy patients were divided into two groups:current hydrogel contact lens wearers refitted with lotrafilcon B lenses(Group 1;28 patients)and neophyte contact lens wearers(Group 2;27 patients).Each patient's subjective eye comfort was measured with a self-administered questionnaire.The corneas were analyzed using contact specular microscope to measure corneal thickness and the endothelium before the SiH lenses werefitted after four weeks,one month,six months,one year,two years,and three years of lens wear.Results:Subjective complaints of patients in Group 1 were reduced;however patients in Group 2 experienced discomfort during the first two to four weeks of use.In Group 1,objective examinations identified a decrease in endothelial cell density.In Group 2,the endothelial cell density increased slightly in the first two years but decreased after three years.The results indicate that lotra filcon B slows down the deleterious effects of contact lenses.The coe±cient of variation significantly decreased after six months in Group 1(0.47 vs 0.44;p?0:049),whereas,in Group 2,the hexagonal cells improved significantly after one month(27.78 vs 28.25;p=0.025).Conclusion:Based on the subjects involved and the period of time under examination,it can be concluded that high-Dk SiH lenses support the physiological metabolism and functions of the cornea by improving oxygen provision.展开更多
目的:组织工程人角膜内皮(tissue-engineered human corneal endothelia,TE-HCE)的体外重建及其形态结构。方法:用有限稀释法从HCE细胞系筛选出单克隆细胞(mcHCE细胞),用常规染色体标本制作和核型分类学方法进行核型分析。用羊膜的胰酶...目的:组织工程人角膜内皮(tissue-engineered human corneal endothelia,TE-HCE)的体外重建及其形态结构。方法:用有限稀释法从HCE细胞系筛选出单克隆细胞(mcHCE细胞),用常规染色体标本制作和核型分类学方法进行核型分析。用羊膜的胰酶倒置消化和细胞外基质蛋白包被方法制备去上皮层修饰羊膜(mdAM)。以核型正常的对数期mcHCE细胞为种子细胞,以平铺于24孔培养板孔底的mdAM为载体支架,用200mL/L胎牛血清-DMEM/F12培养液在37℃,50mL/LCO2培养箱中进行TE-HCE的体外重建。用茜素红染色、冰冻切片HE染色、倒置显微镜和扫描电镜观察种子细胞的形态、细胞连接的形成情况、细胞单层的完整性及其与mdAM结合的紧密程度。用透射电镜方法鉴定种子细胞的超微结构以及细胞连接的形成情况。用免疫荧光技术检测种子细胞对不同细胞连接蛋白的表达模式。结果:从非转染HCE细胞系中筛选出了7个核型正常(2n=46)的单克隆细胞株。在启动重建30h后,mcHCE种子细胞在mdAM上形成了完整的细胞单层,细胞密度高达3413/mm2。HCE细胞呈多角形细胞形态,形成了完整的细胞单层,且在细胞-细胞以及细胞-mdAM间形成了多种细胞连接,种子细胞在超微结构上与在体HCE细胞类似,胞质中含有许多线粒体,并具有紧密连接蛋白-1、钙黏蛋白、间隙连接蛋白-43和整联蛋白αv/β5的阳性表达。结论:体外重建的TE-HCE在结构和功能上与在体HCE相似,有望作为HCE的替代物用于临床角膜内皮移植。展开更多
文摘Corneal stem/progenitor cells are typical adult stem/progenitor cells.The human cornea covers the front of the eyeball,which protects the eye from the outside environment while allowing vision.The location and function demand the cornea to maintain its transparency and to continuously renew its epithelial surface by replacing injured or aged cells through a rapid turnover process in which corneal stem/progenitor cells play an important role.Corneal stem/progenitor cells include mainly corneal epithelial stem cells,corneal endothelial cell progenitors and corneal stromal stem cells.Since the discovery of corneal epithelial stem cells(also known as limbal stem cells)in 1971,an increasing number of markers for corneal stem/progenitor cells have been proposed,but there is no consensus regarding the definitive markers for them.Therefore,the identification,isolation and cultivation of these cells remain challenging without a unified approach.In this review,we systematically introduce the profile of biological characterizations,such as anatomy,characteristics,isolation,cultivation and molecular markers,and clinical applications of the three categories of corneal stem/progenitor cells.
文摘Major advances are currently being made in regenerative medicine for cornea. Stem cell-based therapies represent a novel strategy that may substitute conventional corneal transplantation, albeit there aremany challenges ahead given the singularities of each cellular layer of the cornea. This review recapitulates the current data on corneal epithelial stem cells, corneal stromal stem cells and corneal endothelial cell progenitors. Corneal limbal autografts containing epithelial stem cells have been transplanted in humans for more than 20 years with great successful rates, and researchers now focus on ex vivo cultures and other cell lineages to transplant to the ocular surface. A small population of cells in the corneal endothelium was recently reported to have self-renewal capacity, although they do not proliferate in vivo. Two main obstacles have hindered endothelial cell transplantation to date: culture protocols and cell delivery methods to the posterior cornea in vivo. Human corneal stromal stem cells have been identified shortly after the recognition of precursors of endothelial cells. Stromal stem cells may have the potential to provide a direct cell-based therapeutic approach when injected to corneal scars. Furthermore, they exhibit the ability to deposit organized connective tissue in vitro and may be useful in corneal stroma engineering in the future. Recent advances and future perspectives in the field are discussed.
基金The funding for the author’s research has been supported by the National Eye Institute—NIH,The Michigan Eye Bank,Midwest Eye Bank,Eversight,the Research Excellence Fund of the Center for Biomedical Sciences,Oakland University and the Department of Biological Sciences.
文摘Much of our understanding of the events which underlie cell migration has been derived from studies of cells intissue culture. One of the components that mediates this process is the dynamic actin-based microfilament system that canreorganize itself into so-called stress fibers that are considered essential components for cell motility. In contrast, relativelyfew studies have investigated cell movement along an extracellular matrix (ECM) which is known to influence both cellularorganization and behavior. This opinion/viewpoint article briefly reviews cell migration during corneal endothelial woundrepair along the tissue’s natural basement membrane, Descemet’s membrane. Because the tissue exists as a cell monolayer itaffords one an opportunity to readily explore the effect of cell/matrix influences on cell motility. As such, cell movementalong this substrate differs somewhat from that found in vitro and migrating endothelial cells also demonstrate an abilityto move along the ECM without the benefit of having an organized actin cytoskeleton.
文摘AIM： To compare intraoperative phacoemulsification parameters and its effect on the corneal endothelium of eyes undergoing femtosecond laser-assisted cataract surgery（FLACS） versus conventional phacoemulsification（CP） cataract surgery.METHODS： Two hundred eyes from one hundred patients were included in a prospective, non-blinded, randomized, controlled, intraindividual clinical study. One hundred eyes underwent FLACS while their one hundred fellow eyes underwent CP. All surgeries were performed using the Victus？ femtosecond laser platform and Infinity？ Vision System phacoemulsification machine. Primary outcome measure was endothelial cell density 6 mo after surgery. Secondary outcome measures included central corneal thickness（CCT）, average cell area, standard deviation, coefficient of variation and hexagonality before surgery and 6 mo after surgery and endothelial cell density loss during this period were also evaluated. Intraoperative efficiency parameters [cumulative dissipated energy（CDE）, total intraocular surgery time, total ultrasound time, total phacoemulsification time, total torsional energy time, total aspiration time, ultrasound energy, torsional amplitude and fluid required during surgery] were also collated. RESULTS： Data from these patients was not considered for analysis. Data from 92 patients were analysed. Postoperative endothelial cell density（cells/mm2） between groups（2211.88±392.49 CP; 2246.31±403.48 FLACS） was not statistically significant（P=0.869）. Total ultrasound time, torsional energy time, CDE and fluid requirements were significantly lower the FLACS group（P〈0.05）. Other parameters did not show statistically significant difference between FLACS and CP.CONCLUSION： FLACS displays significant improvements in phacoemulsification parameters in comparison to CP. There are no significant differences in corneal endothelium measures between FLACS and CP.
文摘The examination of the effects of second generation lotra filcon B silicone hydrogel(SiH)lenses on the cornea when worn for three years of daily wear.Material and Methods:55 healthy patients were divided into two groups:current hydrogel contact lens wearers refitted with lotrafilcon B lenses(Group 1;28 patients)and neophyte contact lens wearers(Group 2;27 patients).Each patient's subjective eye comfort was measured with a self-administered questionnaire.The corneas were analyzed using contact specular microscope to measure corneal thickness and the endothelium before the SiH lenses werefitted after four weeks,one month,six months,one year,two years,and three years of lens wear.Results:Subjective complaints of patients in Group 1 were reduced;however patients in Group 2 experienced discomfort during the first two to four weeks of use.In Group 1,objective examinations identified a decrease in endothelial cell density.In Group 2,the endothelial cell density increased slightly in the first two years but decreased after three years.The results indicate that lotra filcon B slows down the deleterious effects of contact lenses.The coe±cient of variation significantly decreased after six months in Group 1(0.47 vs 0.44;p?0:049),whereas,in Group 2,the hexagonal cells improved significantly after one month(27.78 vs 28.25;p=0.025).Conclusion:Based on the subjects involved and the period of time under examination,it can be concluded that high-Dk SiH lenses support the physiological metabolism and functions of the cornea by improving oxygen provision.
文摘目的:组织工程人角膜内皮(tissue-engineered human corneal endothelia,TE-HCE)的体外重建及其形态结构。方法:用有限稀释法从HCE细胞系筛选出单克隆细胞(mcHCE细胞),用常规染色体标本制作和核型分类学方法进行核型分析。用羊膜的胰酶倒置消化和细胞外基质蛋白包被方法制备去上皮层修饰羊膜(mdAM)。以核型正常的对数期mcHCE细胞为种子细胞,以平铺于24孔培养板孔底的mdAM为载体支架,用200mL/L胎牛血清-DMEM/F12培养液在37℃,50mL/LCO2培养箱中进行TE-HCE的体外重建。用茜素红染色、冰冻切片HE染色、倒置显微镜和扫描电镜观察种子细胞的形态、细胞连接的形成情况、细胞单层的完整性及其与mdAM结合的紧密程度。用透射电镜方法鉴定种子细胞的超微结构以及细胞连接的形成情况。用免疫荧光技术检测种子细胞对不同细胞连接蛋白的表达模式。结果:从非转染HCE细胞系中筛选出了7个核型正常(2n=46)的单克隆细胞株。在启动重建30h后,mcHCE种子细胞在mdAM上形成了完整的细胞单层,细胞密度高达3413/mm2。HCE细胞呈多角形细胞形态,形成了完整的细胞单层,且在细胞-细胞以及细胞-mdAM间形成了多种细胞连接,种子细胞在超微结构上与在体HCE细胞类似,胞质中含有许多线粒体,并具有紧密连接蛋白-1、钙黏蛋白、间隙连接蛋白-43和整联蛋白αv/β5的阳性表达。结论:体外重建的TE-HCE在结构和功能上与在体HCE相似,有望作为HCE的替代物用于临床角膜内皮移植。
