Background: Brain injury is the leading cause of death and disability in survivors of cardiac arrest, where neuroinflammation is believed to play a pivotal role, but the underlying mechanism remains unclear. Pyroptosis is a pro-inflammatory form of programmed cell death that triggers inflammatory response upon infection or other stimuli. This study aims to understand the role of microglial pyroptosis in post-cardiac arrest brain injury. Methods: Sprague-Dawley male rats underwent 10-min asphyxial cardiac arrest and cardiopulmonary resuscitation or shamoperation. Flow cytometry analysis, Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), coimmunoprecipitation, and immunofluorescence were used to evaluate activated microglia and CD11b-positive leukocytes after cardiac arrest and assess inflammasome activation and pyroptosis of specific cellular populations. To further explore the underlying mechanism, MCC950 or Ac-YVAD-cmk was administered to block nod-like receptor family protein 3 (NLRP3) or caspase-1, respectively. Results: Our results showed that, in a rat model, successful resuscitation from cardiac arrest resulted in microglial pyroptosis and consequential inflammatory infiltration which was mediated by the activation of NLRP3 inflammasome. Targeting NLRP3 and caspase-1, the executor of pyroptosis, with selective inhibitors MCC950 and Ac-YVAD-cmk treatment significantly prevented microglial pyroptosis, reduced infiltration of leukocytes, improved neurologic outcome, and alleviated neuropathological damages after cardiac arrest in modeling rats. Conclusions: This study demonstrates that microglial pyroptosis mediated by NLRP3 inflammasome is critically involved in the pathogenesis of post-cardiac arrest brain injury and provides a new therapeutic strategy.

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In this project, a highly precise quantitative method based on the digital polymerase chain reaction (dPCR) technique was developed to determine the weight of pork and chicken in meat products. Real-time quantitative polymerase chain reaction (qPCR) is currently used for quantitative molecular analysis of the presence of species-specific DNAs in meat products. However, it is limited in amplification efficiency and relies on standard curves based Ct values, detecting and quantifying low copy number target DNA, as in some complex mixture meat products. By using the dPCR method, we find the relationships between the raw meat weight and DNA weight and between the DNA weight and DNA copy number were both close to linear. This enabled us to establish formulae to calculate the raw meat weight based on the DNA copy number. The accuracy and applicability of this method were tested and verified using samples of pork and chicken powder mixed in known proportions. Quantitative analysis indicated that dPCR is highly precise in quantifying pork and chicken in meat products and therefore has the potential to be used in routine analysis by government regulators and quality control departments of commercial food and feed enterprises.

Di-(2-ethylhexyl)-phthalate (DEHP) is a ubiquitously used endocrine disruptor.There is widespread exposure to DEHP in the general population which has raised substantial public concern due to its potential detrimental health effects. It is particularly pertinent to investigate the molecular mechanisms of its testicular toxicity which are largely unknown. By feeding male rats DEHP for 2 weeks, rat spermatogenesis became disrupted, resulting in a decreased number of spermatocytes and spermatids. Since rapidly dividing tissues appeared to be particularly vulnerable to DEHP toxicity we investigated the effect of DEHP on DNA replication. Intriguingly, DEHP appeared to inhibit DNA replication as evidenced by results of fiber tract analysis. This led to induction of the mitochondrial apoptotic pathways and increased ROS production. Furthermore, the toxicity of DEHP led to respiratory chain defects and attenuation of ATP level probably brought about by hyperPARylation and undermined SIRT1 activity. Our findings reveal a previously unknown mitochondrial dysfunction in DEHP-induced testicular toxicity and highlight the importance of SIRT1 in male reproduction.

The breakdown of the blood-brain barrier (BBB) is related to the occurrence and deterioration of neurological dysfunction in ischemic stroke, which leads to the extravasation of blood-borne substances, resulting in vasogenic edema and increased mortality. However, a limited understanding of the molecular mechanisms that control the restrictive properties of the BBB hinders the manipulation of the BBB in disease and treatment. Here, we found that the glycocalyx (GCX) is a critical factor in the regulation of brain endothelial barrier integrity.First, endothelial GCX displayed a biphasic change pattern, of which the timescale matched well with the biphasic evolution of BBB permeability to tracers within the first week after t-MCAO. Moreover, GCX destruction with hyaluronidase increased BBB permeability in healthy mice and aggravated BBB leakage in transient middle cerebral artery occlusion (t-MCAO) mice. Surprisingly, ultrastructural observation showed that GCX destruction was accompanied by increased endothelial transcytosis at the ischemic BBB, while the tight junctions remained morphologically and functionally intact. Knockdown of ca-veolin1 (Cav1) suppressed endothelial transcytosis, leading to reduced BBB permeability, and brain edema. Lastly, a coimmunoprecipitation assay showed that GCX degradation enhanced the interaction between syndecan1 and Src by promoting the binding of phosphorylated syndecan1 to the Src SH2 domain, which led to rapid modulation of cytoskeletal proteins to promote caveolaemediated endocytosis. Overall, these findings demonstrate that the dynamic degradation and reconstruction of GCX may account for the biphasic changes in BBB permeability in ischemic stroke, and reveal an essential role of GCX in suppressing transcellular transport in brain endothelial cells to maintain BBB integrity. Targeting GCX may provide a novel strategy for managing BBB dysfunction and central nervous system drug delivery. | M AT ER I A L S A N D M ET HOD S | AnimalsMale C57BL/6J background mice were obtained from the Experimental Animal Center of Southern Medical University and housed under a 12-h light/dark cycle in a pathogen-free facility with free access to water and blood-brain barrier, brain edema, caveolin1, glycocalyx, ischemia stroke, transcytosis