Effect of Huatan Tongluo Decoction on Gut-Brain Axis in Rats with Cerebral Ischemia/Reperfusion / 中国实验方剂学杂志

Objective:To explore the effects of Huatan Tongluo Decoction （HTTLD） on the morphology and function of brain tissues and intestine in rats with cerebral ischemia/reperfusion based on the gut-brain axis. Method:Sixty SPF male rats were randomly divided into a sham operation group， a model group， high- （28.66 g·kg^-1）， medium- （14.33 g·kg^-1）， and low-dose （7.16 g·kg^-1） HTTLD groups， and an edaravone （4 g·kg^-1）+<italic>Clostridium butyricum</italic> （5.0×10⁸ cfu·mL^-1） group. The model was established by focal cerebral ischemia/reperfusion in rats. The drugs were administered by gavage. The brain tissue injury was determined by neurological deficit score and 2，3，5-triphenyl tetrazolium chloride （TTC） staining. The effect of cerebral ischemia/reperfusion on intestinal motility was assessed by the propulsion rate of small intestine. The intestinal mucosal cell damage was evaluated by the pathomorphological examination of the duodenal mucosa. Enzyme-linked immunosorbent assay （ELISA） was used to determine the content of <italic>D</italic>-lactate （<italic>D</italic>-LAC）， diamine oxidase （DAO）， and bacterial endotoxin （lipopolysaccharide， LPS） in serum. Western blot was used to detect the expression of Occludin， Claudin-5， and zonula occludens 1 （ZO-1） in the duodenum. Result:After cerebral ischemia/reperfusion， rats developed neurological deficit symptoms. The neurological deficit score in the model group was higher than that in the sham operation group （<italic>P<</italic>0.01）. Compared with the model group， the high- and medium-dose HTTLD groups could relieve the symptoms of neurological deficits and lower neurological deficit scores （<italic>P<</italic>0.01）. The results of TTC staining showed that the model group presented obvious infarcts in brain tissues compared with the sham operation group （<italic>P<</italic>0.01）. The cerebral infarction volumes of HTTLD groups were reduced compared with that in the model group （<italic>P<</italic>0.01）， especially the high-dose HTTLD group， and the effect was dose-dependent. Furthermore， the propulsion rate of small intestine in the model group was significantly reduced compared with that in the sham operation group （<italic>P<</italic>0.01）. Compared with the model group， HTTLD groups could increase propulsion rates of small intestine （<italic>P<</italic>0.01）， especially the high-dose HTTLD group， and the effect was dose-dependent. After cerebral ischemia/reperfusion， obvious duodenal mucosal damage could be observed， which was relieved after the administration of HTTLD. Western blot results showed that the protein expression of ZO-1， Occludin， and Claudin-5 in the model group was reduced compared with that in the sham operation group （<italic>P<</italic>0.01）. Compared with the model group， the HTTLD groups could up-regulate the expression of ZO-1， Occludin， and Claudin-5 to varying degrees （<italic>P<</italic>0.05， <italic>P<</italic>0.01）， especially the high-dose HTTLD group. ELISA showed that the serum <italic>D</italic>-LAC， DAO， and LPS of the model group were elevated compared with those in the sham operation group （<italic>P<</italic>0.01）. Compared with the model group， the HTTLD groups showed reduced <italic>D</italic>-LAC and DAO （<italic>P<</italic>0.05， <italic>P<</italic>0.01）， and the medium- and high-dose HTTLD groups showed reduced LPS （<italic>P<</italic>0.05， <italic>P<</italic>0.01）， especially the high-dose HTTLD group. Conclusion:After cerebral ischemia/reperfusion， the rats showed damaged brain tissues， neurological dysfunction， intestinal mucosal injury， weakened intestinal motility， and destroyed the intestinal mucosal barrier. HTTLD can protect against brain-gut axis injury after cerebral ischemia/reperfusion by reducing the damage on brain tissues and gastrointestinal mucosa， relieving the symptoms of neurological deficits， promoting gastrointestinal motility， improving intestinal barrier function， and reducing the release of intestinal bacterial metabolites or poisons.

Association between neutralizing antibodies to SARS-CoV-2 and commercial serological assays

Introduction Commercially available SARS-CoV-2 serological assays based on different viral antigens have been approved for the qualitative determination of anti-SARS-CoV-2 antibodies. However, there is limited published data associating the results from commercial assays with neutralizing antibodies.Methods 67 specimens from 48 patients with PCR-confirmed COVID-19 and a positive result by the Roche Elecsys SARS-CoV-2, Abbott SARS-CoV-2 IgG, or EUROIMMUN SARS-CoV-2 IgG assays and 5 control specimens were analyzed for the presence of neutralizing antibodies to SARS-CoV-2. Correlation, concordance, positive percent agreement (PPA), and negative percent agreement (NPA) were calculated at several cutoffs. Results were compared in patients categorized by clinical outcomes.Results The correlation between SARS-CoV-2 neutralizing titer (EC50) and the Roche, Abbott, and EUROIMMUN assays was 0.29, 0.47, and 0.46 respectively. At an EC50 of 1:32, the concordance kappa with Roche was 0.49 (95% CI; 0.23-0.75), with Abbott was 0.52 (0.28-0.77), and with EUROIMMUN was 0.61 (0.4-0.82). At the same neutralizing titer, the PPA and NPA for the Roche was 100% (94-100) & 56% (30-80); Abbott was 96% (88-99) & 69% (44-86); and EUROIMMUN was 91% (80-96) & 81% (57-93) for distinguishing neutralizing antibodies. Patients who died, were intubated, or had a cardiac injury from COVID-19 infection had significantly higher neutralizing titers relative to those with mild symptoms.Conclusion COVID-19 patients generate an antibody response to multiple viral proteins such that the calibrator ratios on the Roche, Abbott, and EUROIMMUN assays are all associated with SARS-CoV-2 neutralization. Nevertheless, commercial serological assays have poor NPA for SARS-CoV-2 neutralization, making them imperfect proxies for neutralization.Competing Interest StatementThe authors have declared no competing interest.View Full Text

Effect of borneol combined with astragaloside IV and Panax notoginseng saponins on transporter proteins of blood-brain barrier after cerebral ischemia-reperfusion / 中草药

Objective: To investigate the effects of borneol combined with astragaloside IV (AST IV) and Panax notoginseng saponins (PNS) on promoting the active components into the brain and anti-brain injury through the regulation of transporter proteins of blood-brain barrier (BBB) in the state of cerebral ischemia-reperfusion. Methods: Focal cerebral ischemia-reperfusion model in rats was established, borneol, AST IV, PNS and the combination were administered by gavage, brain infarction rate was evaluated by 2,3,5-triphenyl tetrazolium chloride (TTC) staining, the expressions of efflux proteins such as p-glycoprotein (P-gp), multidrug resistance protein (MRP)-1, MRP-2, MRP-4, MRP-5 and uptake proteins such as organic cation transporter (OCT)-3, organicanion transporting polypep-tides (OATP)-2 in brain tissues were detected by Western blotting. The expressions of multidrug resistance (MDR) such as mdr1a, mdr1b and mrp-1, mrp-2, mrp-4, mrp-5 mRNA in brain tissues were determined by real-time PCR method. Results: The results of TTC staining showed that brain infarct was found after cerebral ischemia-reperfusion. Each drug could significantly reduce brain infarction volume and decrease infarction rate, and the effect of AST IV + PNS was better than that of AST IV and PNS alone, the effect of borneol + AST IV + PNS was better than that of single drug and AST IV + PNS. The results of major efflux proteins and genes detection showed that the protein expressions of P-gp, MRP-1, MRP 2, MRP-4, and MRP-5 were significantly increased in rats after cerebral ischemia-reperfusion. Borneol could significantly down-regulate the expressions of P-gp, MRP-2, MRP-4 proteins, PNS could significantly down-regulate the levels of MRP-4, MRP-5 proteins; AST IV, AST IV + PNS and borneol + AST IV + PNS could significantly down-regulate P-gp, MRP-2, MRP-4, MRP-5 proteins, and the effects of borneol + AST IV + PNS were significantly better than those of single drug and AST IV + PNS; The effects of AST IV + PNS were significantly better than those of AST IV or PNS alone. The results of gene expressions were similar to those of protein expression. The results of major uptake proteins showed that the expression of OCT-3 protein did not change significantly in the model group and drug groups after cerebral ischemia-reperfusion; However, the expression of OATP-2 protein was significantly decreased in the model group. PNS, AST IV + PNS and borneol + AST IV + PNS could significantly up-regulate the expression of OATP-2 protein; Furthermore, the effect of borneol + AST IV + PNS was significantly greater than that of single drug and AST IV + PNS, and the effect of AST IV + PNS was significantly greater than that of AST IV and PNS alone. Conclusion: After cerebral ischemia-reperfusion, brain tissues were damaged, the expressions of major efflux proteins and genes on BBB were significantly increased, while the expression of uptake protein such as OATP-2 was significantly decreased. Borneol combined with AST IV and PNS can enhance the effect of anti-ischemic brain injury, which may be related to the down-regulations of the expressions of efflux proteins such as P-gp, MRP-2, MRP-4, MRP-5 and corresponding genes in BBB, as well as the up-regulation of the expression of uptake proteins such as OATP-2, thus promoting the absorption and the enrichment of borneol, AST IV and the effective components of PNS in brain tissues, playing a better role in pharmacology.

Vitamin A mediates conversion of monocyte-derived macrophages into tissue-resident macrophages during alternative activation.

It remains unclear whether activated inflammatory macrophages can adopt features of tissue-resident macrophages, or what mechanisms might mediate such a phenotypic conversion. Here we show that vitamin A is required for the phenotypic conversion of interleukin 4 (IL-4)-activated monocyte-derived F4/80intCD206+PD-L2+MHCII+ macrophages into macrophages with a tissue-resident F4/80hiCD206-PD-L2-MHCII-UCP1+ phenotype in the peritoneal cavity of mice and during the formation of liver granulomas in mice infected with Schistosoma mansoni. The phenotypic conversion of F4/80intCD206+ macrophages into F4/80hiCD206- macrophages was associated with almost complete remodeling of the chromatin landscape, as well as alteration of the transcriptional profiles. Vitamin A-deficient mice infected with S. mansoni had disrupted liver granuloma architecture and increased mortality, which indicates that failure to convert macrophages from the F4/80intCD206+ phenotype to F4/80hiCD206- may lead to dysregulated inflammation during helminth infection.

Tazarotene induces apoptosis in human basal cell carcinoma via activation of caspase-8/t-Bid and the reactive oxygen species-dependent mitochondrial pathway.

Previous studies suggest that tazarotene, a new member of the acetylenic class of RARß/γ selective retinoids which is approved to treat a variety of skin diseases, exhibits an anti-proliferative effect in human basal cell carcinoma (BCC) by triggering caspase-dependent apoptosis. However, the detailed molecular mechanisms underlying the anti-tumor activity of tazarotene are poorly understood. This study aims at investigating the molecular mechanisms of tazarotene-induced apoptosis in human BCC cells. Our results are the first to demonstrate that tazarotene induces mitochondria-dependent cleavage of caspase-9 and -3 and PARP in BCC cells by producing reactive oxygen species (ROS) and activating caspase-8 through both ROS and death receptor signaling. These events are accompanied by a decrease in BCL-2 and BCL-xl anti-apoptotic proteins as well as by survivin and XIAP, two IAP family members. Furthermore, our results presented for the first time that tazarotene triggers a convergence of the intrinsic and extrinsic apoptotic pathways via the caspase-8-truncated Bid signaling pathway. Collectively, these data provide insights into the molecular mechanisms underlying tazarotene-induced apoptosis in human BCC cells, suggesting that this compound is a potential anti-skin cancer drug.