Effect of tubastatin A on NLRP3 inflammasome activation in macrophages under hypoxia/reoxygenation conditions
	    		
		   		
		   			
		   		
	    	
    	 
    	10.5847/wjem.j.1920-8642.2024.059
   		
        
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Li HAO
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Liu CHANG
			        		
			        		;
		        		
		        		
		        		
			        		Cui YING
			        		
			        		;
		        		
		        		
		        		
			        		Chang PANPAN
			        		
			        		;
		        		
		        		
		        		
			        		Chong WEI
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. Department of Emergency Medicine,the First Hospital of China Medical University,Shenyang 110001,China
			        		
		        		
	        		
        		 
        	
        	
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Hemorrhagic shock;
			        		
			        		
			        		
				        		Hypoxia/reoxygenation;
			        		
			        		
			        		
				        		Macrophage;
			        		
			        		
			        		
				        		NLRP3;
			        		
			        		
			        		
				        		Tubastatin A
			        		
			        		
	        			
        			
        		
 
        	
            
            
            	- From:
	            		
	            			World Journal of Emergency Medicine
	            		
	            		 2024;15(4):289-296
	            	
            	
 
            
            
            	- CountryChina
 
            
            
            	- Language:Chinese
 
            
            
            	- 
		        	Abstract:
			       	
			       		
				        
				        	BACKGROUND:There are currently no effective drugs to mitigate the ischemia/reperfusion injury caused by fluid resuscitation after hemorrhagic shock(HS).The aim of this study was to explore the potential of the histone deacetylase 6(HDAC6)-specific inhibitor tubastatin A(TubA)to suppress nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3)inflammasome activation in macrophages under hypoxia/reoxygenation(H/R)conditions. METHODS:The viability of RAW264.7 cells subjected to H/R after treatment with different concentrations of TubA was assessed using a cell-counting kit-8(CCK8)assay.Briefly,2.5 μmol/L TubA was used with RAW264.7 cells under H/R condition.RAW264.7 cells were divided into three groups,namely the control,H/R,and TubA groups.The levels of reactive oxygen species(ROS)in the cells were detected using fluorescence microscopy.The protein expression of HDAC6,heat shock protein 90(Hsp90),inducible nitric oxide synthase(iNOS),NLRP3,gasdermin-D(GSDMD),Caspase-1,GSDMD-N,and Caspase-1 p20 was detected by western blotting.The levels of interleukin-1β(IL-1β)and IL-18 in the supernatants were detected using enzyme-linked immunosorbent assay(ELISA). RESULTS:HDAC6,Hsp90,and iNOS expression levels were significantly higher(P<0.01)in the H/R group than in the control group,but lower in the TubA group than in the H/R group(P<0.05).When comparing the H/R group to the control group,ROS levels were significantly higher(P<0.01),but significantly reduced in the TubA group(P<0.05).The H/R group had higher NLRP3,GSDMD,Caspase-1,GSDMD-N,and Caspase-1 p20 expression levels than the control group(P<0.05),however,the TubA group had significantly lower expression levels than the H/R group(P<0.05).IL-1β and IL-18 levels in the supernatants were significantly higher in the H/R group compared to the control group(P<0.01),but significantly lower in the TubA group compared to the H/R group(P<0.01). CONCLUSION:TubA inhibited the expression of HDAC6,Hsp90,and iNOS in macrophages subjected to H/R.This inhibition led to a decrease in the content of ROS in cells,which subsequently inhibited the activation of the NLRP3 inflammasome and the secretion of IL-1β and IL-18.