Effects of polymorphonuclear neutrophils on protein synthesis by alkali-injured rabbit corneas. A preliminary study.
Invasion of polymorphonuclear neutrophils (PMN) into injured cornea is one of the early events in corneal wound-healing. In the present studies, we examine the mutual effects on protein synthesis by PMN and injured and normal corneas when they are cocultured. PMN were labeled with [35S]methionine in the presence or absence of normal or alkali-injured rabbit corneas for 1-5 h. The acid-insoluble 35S-labeled proteins in medium, cells, and tissues were measured. Our data indicate that alkali-injured rabbit corneas induce higher rates of incorporation of [35S]methionine and secretion of 35S-labeled newly synthesized proteins by PMN. The newly synthesized 35S-labeled proteins were then analyzed by two-dimensional PAGE. The results indicate that alkali-injured and normal rabbit corneas enhance the synthesis and secretion of a 18-kD protein by PMN. In contrast, alkali injury greatly reduced the secretion of a group of proteins having molecular weights of approximately 30 kD by rabbit corneas. The alkali-injured corneas synthesize a new 200-kD protein (AC-200) in tissues and increase the secretion of a 120-kD protein (AC-120) into the culture medium. Furthermore, PMN slightly inhibits the incorporation of [35S]methionine and alter the synthesis of several 35S-labeled proteins by normal and injured corneas. For example, incubation with PMN abolishes the synthesis of the AC-200 protein, but enhances the secretion of the AC-120 protein by the alkali-injured corneas. However, the function and nature of these proteins remain largely unknown. Further studies are needed to elucidate the biological roles of these polypeptides during corneal wound healing.
Kao
W W
WW
Department of Ophthalmology, University of Cincinnati, Ohio 45267-0527.
Zhu
G
G
Kao
C W
CW
D000818:Animals; D002057:Burns, Chemical / Q000378:metabolism*; D002478:Cells, Cultured; D003315:Cornea / Q000378:metabolism*; D065306:Corneal Injuries; D004195:Disease Models, Animal; D015180:Electrophoresis, Gel, Two-Dimensional; D005126:Eye Burns / Q000139:chemically induced / Q000378:metabolism*; D005136:Eye Proteins / Q000096:biosynthesis*; D005260:Female; D008297:Male; D008715:Methionine / Q000378:metabolism; D009504:Neutrophils / Q000502:physiology*; D009924:Organ Culture Techniques; D011817:Rabbits; D012972:Sodium Hydroxide; D013462:Sulfur Radioisotopes; D014945:Wound Healing
D005136:Eye Proteins; D013462:Sulfur Radioisotopes; D012972:Sodium Hydroxide; D008715:Methionine