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BackgroundNucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome is associated with metabolic disorder and cell death, which are important triggers in diabetic cardiomyopathy (DCM). We aimed to explore whether NLRP3 inflammasome activation contributes to DCM and the mechanism involved.MethodsType 2 diabetic rat model was induced by high fat diet and low dose streptozotocin. The characteristics of type 2 DCM were evaluated by metabolic tests, echocardiography and histopathology. Gene silencing therapy was used to investigate the role of NLRP3 in the pathogenesis of DCM. High glucose treated H9c2 cardiomyocytes were used to determine the mechanism by which NLRP3 modulated the DCM. The cell death in vitro was detected by TUNEL and EthD-III staining. TXNIP-siRNA and pharmacological inhibitors of ROS and NF-kB were used to explore the mechanism of NLRP3 inflammasome activation.ResultsDiabetic rats showed severe metabolic disorder, cardiac inflammation, cell death, disorganized ultrastructure, fibrosis and excessive activation of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), pro-caspase-1, activated caspase-1 and mature interleukin-1β (IL-1β). Evidence for pyroptosis was found in vivo, and the caspase-1 dependent pyroptosis was found in vitro. Silencing of NLRP3 in vivo did not attenuate systemic metabolic disturbances. However, NLRP3 gene silencing therapy ameliorated cardiac inflammation, pyroptosis, fibrosis and cardiac function. Silencing of NLRP3 in H9c2 cardiomyocytes suppressed pyroptosis under high glucose. ROS inhibition markedly decreased nuclear factor-kB (NF-kB) phosphorylation, thioredoxin interacting/inhibiting protein (TXNIP), NLRP3 inflammasome, and mature IL-1β in high glucose treated H9c2 cells. Inhibition of NF-kB reduced the activation of NLRP3 inflammasome. TXNIP-siRNA decreased the activation of caspase-1 and IL-1β.ConclusionNLRP3 inflammasome contributed to the development of DCM. NF-κB and TXNIP mediated the ROS-induced caspase-1 and IL-1β activation, which are the effectors of NLRP3 inflammasome. NLRP3 gene silencing may exert a protective effect on DCM.

Seminal fluid proteins transferred from males to females during copulation are required for full fertility and can exert dramatic effects on female physiology and behavior. In Drosophila melanogaster, the seminal protein sex peptide (SP) affects mated females by increasing egg production and decreasing receptivity to courtship. These behavioral changes persist for several days because SP binds to sperm that are stored in the female. SP is then gradually released, allowing it to interact with its female-expressed receptor. The binding of SP to sperm requires five additional seminal proteins, which act together in a network. Hundreds of uncharacterized male and female proteins have been identified in this species, but individually screening each protein for network function would present a logistical challenge. To prioritize the screening of these proteins for involvement in the SP network, we used a comparative genomic method to identify candidate proteins whose evolutionary rates across the Drosophila phylogeny co-vary with those of the SP network proteins. Subsequent functional testing of 18 co-varying candidates by RNA interference identified three male seminal proteins and three female reproductive tract proteins that are each required for the long-term persistence of SP responses in females. Molecular genetic analysis showed the three new male proteins are required for the transfer of other network proteins to females and for SP to become bound to sperm that are stored in mated females. The three female proteins, in contrast, act downstream of SP binding and sperm storage. These findings expand the number of seminal proteins required for SP's actions in the female and show that multiple female proteins are necessary for the SP response. Furthermore, our functional analyses demonstrate that evolutionary rate covariation is a valuable predictive tool for identifying candidate members of interacting protein networks.

The 2003 International Society of Nephrology/Renal Pathology Society (ISN/RPS) system for classifying patients with lupus nephritis was based on glomerular lesions exclusively, despite the fact that lupus nephritis affects all compartments of the kidney. Hence, we analyzed the tubulointerstitial lesions in patients with lupus nephritis within the different classes and subclasses of the 2003 ISN/RPS system. Among 313 patients from five centers in northern China with lupus nephritis, interstitial inflammatory cell infiltration, tubular atrophy, and interstitial fibrosis were severe in 170 patients with class IV, moderate in 55 with class III, and mild in 19 with class II and in 69 with class V disease, each with significance. The severity of tubulointerstitial lesions in classes IV-segmental and III was similar, whereas the score of interstitial inflammatory cell infiltration in patients with subclass IV-global was significantly higher than that in those with subclass IV-segmental. Interstitial fibrosis and tubular atrophy were each significantly more prominent in patients with both active and chronic lesions than in those with active lesions alone. The correlation coefficient ranged from 0.222 to 0.811 comparing glomerular and tubulointerstitial indices. In multivariate Cox hazard analysis of tubulointerstitial lesions, indices of interstitial infiltration, tubular atrophy, and interstitial fibrosis were confirmed as significant independent risk factors for renal outcome. Thus, we found that the 2003 ISN/RPS classification system of lupus nephritis, based on glomerular lesions, could also reflect related tubulointerstitial lesions. Hence, we suggest that the extent of tubulointerstitial lesions may be helpful in predicting renal outcome in patients with lupus nephritis.

The beneficial effect of RSV on DCM depended on inhibited NLRP3 inflammasome, and correlated with suppression of the MAPKs.