Corneal diseases are a major cause of blindness in the world. Although great progress has been achieved in the treatment of corneal diseases, wound healing after severe corneal damage and immunosuppressive therapy aft...Corneal diseases are a major cause of blindness in the world. Although great progress has been achieved in the treatment of corneal diseases, wound healing after severe corneal damage and immunosuppressive therapy after corneal transplantation remain prob-lematic. Mesenchymal stem cells(MSCs) derived from bone marrow or other adult tissues can differentiate into various types of mesenchymal lineages, such as osteocytes, adipocytes, and chondrocytes, both in vivo and in vitro. These cells can further differentiate into specific cell types under specific conditions. MSCs migrate to injury sites and promote wound healing by secreting anti-inflammatory and growth factors. In ad-dition, MSCs interact with innate and acquired immune cells and modulate the immune response through their powerful paracrine function. Over the last decade, MSCs have drawn considerable attention because of their beneficial properties and promising therapeutic prospective. Furthermore, MSCs have been applied to various studies related to wound healing, autoim-mune diseases, and organ transplantation. This review discusses the potential functions of MSCs in protecting corneal tissue and their possible mechanisms in corneal wound healing and corneal transplantation.展开更多
●AIM:To explore netrin-1 functions on corneal epithelium in vitro and in vivo.●METHODS:In vitro the human corneal epithelial(HCE)cells were treated with serum free DMEM-F12 basic media containing 0,50,100,200,300,50...●AIM:To explore netrin-1 functions on corneal epithelium in vitro and in vivo.●METHODS:In vitro the human corneal epithelial(HCE)cells were treated with serum free DMEM-F12 basic media containing 0,50,100,200,300,500,800,and 1000 ng/mL of netrin-1,respectively.The cells viability was detected by cell counting kit-8(CCK-8).The wound-healing assay was applied to assess the migration proficiency of HCE cells.Flow cytometry was used to analyze the cell-cycle distribution and apoptosis.In vivo,normal c57(6 wk)mice were demarcated with a trephine in the middle of the cornea to produce a 3-mm circular wound.Mice corneas were inflicted no epithelium with a 3-mm wound displayed,but remained the limbal epithelium intact.A blunt scalpel blade was used to remove the corneal epithelian cells,followed by topical netrin-1 application(200 ng/mL),and the group treated by PBS as control.The treated group was injected netrin-1 into the normal c57 mice inferior subconjunctival 4 h before trauma.Mouse corneal inflammation and neovascularization were observed under slit lamp microscope.The apoptosis of corneal cells was determined by TUNEL staining.●RESLUTS:A concentration of 200 ng/mL netrin-1 enhanced 25%of the HCE viability.The relative migration rates were 76.3%and 100%in control and netrin-1 treated group after cultured 72 h.Treated with netrin-1(200 ng/mL)decreased the apoptosis of HCE cells,as well as decreased their percentage from 19.3%±0.57%to 12.7%±0.42%of the total.The remaining wound area was 1.22 mm2 in control group but 0.22 mm2 in the netrin-1 treated group.Exogenous Netrin-1 inhibits apoptosis of corneal epithelial cells of c57 mice.TUNEL-positive cells at the epithelial layer of the corneas of the control and netrin-1 treated c57 mice at 24 h after wounding were 43.3%and 16.7%respectively.●CONCLUSION:Netrin-1 can reduce HCE apoptosis as well as promote its proliferation and migration.Topical application of netrin-1 promotes the injuryed cornea epithelial wound repair and inhibits apoptosis of corneal epithelial cells.These findings may offer potential therapies to repair the defects of corneal epithelial based on netrin-1.展开更多
A strong cohort of evidence exists that supports the localisation of corneal stem cells at the limbus. The distinguishing characteristics of limbal cells as stem cells include slow cycling properties, high proliferati...A strong cohort of evidence exists that supports the localisation of corneal stem cells at the limbus. The distinguishing characteristics of limbal cells as stem cells include slow cycling properties, high proliferative potential when required, clonogenicity, absence of differentiation marker expression coupled with positive expression of progenitor markers, multipotency, centripetal migration, requirement for a distinct niche environment and the ability of transplanted limbal cells to regenerate the entire corneal epithelium. The existence of limbal stem cells supports the prevailing theory of corneal homeostasis, known as the XYZ hypothesis where X represents proliferation and stratification of limbal basal cells, Y centripetal migration of basal cells and Z desquamation of superficial cells. To maintain the mass of cornea, the sum of X and Y must equal Z and very elegant cell tracking experiments provide strong evidence in support of this theory. However, several recent stud-ies have suggested the existence of oligopotent stem cells capable of corneal maintenance outside of the limbus. This review presents a summary of data which led to the current concepts of corneal epithelial homeostasis and discusses areas of controversy surrounding the existence of a secondary stem cell reservoir on the corneal展开更多
文摘Corneal diseases are a major cause of blindness in the world. Although great progress has been achieved in the treatment of corneal diseases, wound healing after severe corneal damage and immunosuppressive therapy after corneal transplantation remain prob-lematic. Mesenchymal stem cells(MSCs) derived from bone marrow or other adult tissues can differentiate into various types of mesenchymal lineages, such as osteocytes, adipocytes, and chondrocytes, both in vivo and in vitro. These cells can further differentiate into specific cell types under specific conditions. MSCs migrate to injury sites and promote wound healing by secreting anti-inflammatory and growth factors. In ad-dition, MSCs interact with innate and acquired immune cells and modulate the immune response through their powerful paracrine function. Over the last decade, MSCs have drawn considerable attention because of their beneficial properties and promising therapeutic prospective. Furthermore, MSCs have been applied to various studies related to wound healing, autoim-mune diseases, and organ transplantation. This review discusses the potential functions of MSCs in protecting corneal tissue and their possible mechanisms in corneal wound healing and corneal transplantation.
基金Supported by the National Natural Science Foundation of China(No.81300729,No.81160118,No.81460092,No.81660158)Natural Science Foundation of Fujian Province(No.2015J05170).
文摘●AIM:To explore netrin-1 functions on corneal epithelium in vitro and in vivo.●METHODS:In vitro the human corneal epithelial(HCE)cells were treated with serum free DMEM-F12 basic media containing 0,50,100,200,300,500,800,and 1000 ng/mL of netrin-1,respectively.The cells viability was detected by cell counting kit-8(CCK-8).The wound-healing assay was applied to assess the migration proficiency of HCE cells.Flow cytometry was used to analyze the cell-cycle distribution and apoptosis.In vivo,normal c57(6 wk)mice were demarcated with a trephine in the middle of the cornea to produce a 3-mm circular wound.Mice corneas were inflicted no epithelium with a 3-mm wound displayed,but remained the limbal epithelium intact.A blunt scalpel blade was used to remove the corneal epithelian cells,followed by topical netrin-1 application(200 ng/mL),and the group treated by PBS as control.The treated group was injected netrin-1 into the normal c57 mice inferior subconjunctival 4 h before trauma.Mouse corneal inflammation and neovascularization were observed under slit lamp microscope.The apoptosis of corneal cells was determined by TUNEL staining.●RESLUTS:A concentration of 200 ng/mL netrin-1 enhanced 25%of the HCE viability.The relative migration rates were 76.3%and 100%in control and netrin-1 treated group after cultured 72 h.Treated with netrin-1(200 ng/mL)decreased the apoptosis of HCE cells,as well as decreased their percentage from 19.3%±0.57%to 12.7%±0.42%of the total.The remaining wound area was 1.22 mm2 in control group but 0.22 mm2 in the netrin-1 treated group.Exogenous Netrin-1 inhibits apoptosis of corneal epithelial cells of c57 mice.TUNEL-positive cells at the epithelial layer of the corneas of the control and netrin-1 treated c57 mice at 24 h after wounding were 43.3%and 16.7%respectively.●CONCLUSION:Netrin-1 can reduce HCE apoptosis as well as promote its proliferation and migration.Topical application of netrin-1 promotes the injuryed cornea epithelial wound repair and inhibits apoptosis of corneal epithelial cells.These findings may offer potential therapies to repair the defects of corneal epithelial based on netrin-1.
基金Supported by Save Sight Society New Zealanduckland Medical Research Foundation
文摘A strong cohort of evidence exists that supports the localisation of corneal stem cells at the limbus. The distinguishing characteristics of limbal cells as stem cells include slow cycling properties, high proliferative potential when required, clonogenicity, absence of differentiation marker expression coupled with positive expression of progenitor markers, multipotency, centripetal migration, requirement for a distinct niche environment and the ability of transplanted limbal cells to regenerate the entire corneal epithelium. The existence of limbal stem cells supports the prevailing theory of corneal homeostasis, known as the XYZ hypothesis where X represents proliferation and stratification of limbal basal cells, Y centripetal migration of basal cells and Z desquamation of superficial cells. To maintain the mass of cornea, the sum of X and Y must equal Z and very elegant cell tracking experiments provide strong evidence in support of this theory. However, several recent stud-ies have suggested the existence of oligopotent stem cells capable of corneal maintenance outside of the limbus. This review presents a summary of data which led to the current concepts of corneal epithelial homeostasis and discusses areas of controversy surrounding the existence of a secondary stem cell reservoir on the corneal
