Effects of heat treatment on the activity of cultured human melanocytes irradiated by ultraviolet B in vitro
	    		
		   		
		   			
		   		
	    	
    	 
    	10.3760/cma.j.issn.0412-4030.2012.05.013
   		
        
        	
        		- VernacularTitle:热处理对UVB辐射后体外培养人黑素细胞活性的影响
 
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Wenting SONG
			        		
			        		;
		        		
		        		
		        		
			        		Guang ZHAO
			        		
			        		;
		        		
		        		
		        		
			        		Jianrong NIU
			        		
			        		;
		        		
		        		
		        		
			        		Rusong MENG
			        		
			        		;
		        		
		        		
		        		
			        		Yue ZHANG
			        		
			        		;
		        		
		        		
		        		
			        		Lifang SHAO
			        		
			        		;
		        		
		        		
		        		
			        		Yu CHENG
			        		
			        		;
		        		
		        		
		        		
			        		Wenting YAN
			        		
			        		
		        		
		        		
		        		
		        		
		        		
			        		
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:Journal Article
 
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Heat;
			        		
			        		
			        		
				        		Ultraviolet rays;
			        		
			        		
			        		
				        		Melanocytes;
			        		
			        		
			        		
				        		Cell cycle
			        		
			        		
	        			
        			
        		
 
        	
            
            
            	- From:
	            		
	            			Chinese Journal of Dermatology
	            		
	            		 2012;45(5):340-343
	            	
            	
 
            
            
            	- CountryChina
 
            
            
            	- Language:Chinese
 
            
            
            	- 
		        	Abstract:
			       	
			       		
				        
				        	ObjectiveTo investigate the effect of heat treatment combined with narrow band ultraviolet B(NB-UVB) on cultured normal human melanocytes in vitro.MethodsMelanocytes were isolated from the foreskin of normal human,cullured in vitro,and irradiated with NB-UVB of different doses(20,30,50,70,90,120 and 180 mJ/cm2).Then,MTT assay was performed to evaluate the proliferation and activity of melanocytes to determine the optimal dose of UVB for the next experiment.Melanocytes were classified into 3 groups to be treated with heat at 42 ℃ for 1 hour (heat group),irradiated with UVB at 50 mJ/cm2 (UVB group),or irradiated with UVB at 50 mJ/cm2 followed by heat treatment at 42 ℃ for 1 hour (combination group),daily for 3 successive days; those receiving no treatment served as the control.After 24-hour culture following the last treatment,tyrosinase activity was evaluated with L-dopa as the substrate,melanin content was detected by NaOH assay,and cell cycle stages were determined by flow cytometry.ResultsNB-UVB irradiation decreased the viability of melanocytes in a dose-dependent manner,and the optimum dose of UVB was 50 mJ/cm2.The tyrosinase activity of melanocytes was 0.244 ± 0.018 and 0.310 ± 0.015 respectively in the UVB group and combination group,and increased by 3.8% (P < 0.05) and 31.9% (P < 0.05) respectively compared with the control group (0.235 ± 0.018); the melanin content was 0.201 ± 0.016 and 0.286 ± 0.019,respectively in the UVB group and combination group,and increased by 17.5% (P < 0.05 ) and 67.3% (P < 0.05) compared with the control group (0.171 ± 0.016).In comparison with the control group,the percentage of melanocytes in G1 phase was decreased by 23.94% in the UVB group(P< 0.05) and 33.51% in the combination group(P < 0.05),while that in S phase and G2 phase increased by 15.35% (P < 0.05 ) and 11.93% (P < 0.05),respectively in the UVB group,and 17.76% (P > 0.05) and 16.08% (P > 0.05),respectively in the heat group.ConclusionHeat treatment and NB-UVB can synergistically enhance the tyrosinase activity and accelerate melanogenesis,proliferation and differentiation,of melanocytes.