Abstract According to a 2019 report from the Centers of Disease Control and Prevention (CDC), methicillin-resistant Staphylococcus aureus (MRSA) was listed as one of the “serious threats” that had become a global public challenge in hospitals and community. Biofilm-associated infections and refractory persisters of S. aureus also impede the effectiveness of conventional antibiotics that have greatly increased difficulty in clinical therapy. There is an urgent need to develop new antimicrobials with antibiofilm and anti-persister capacities, and drug repurposing is the most effective and most economical solution to the problem. The present study profiles the antimicrobial activity of ceritinib, a tyrosine kinase inhibitor, against S. aureus in vitro and in vivo. We investigated the antimicrobial efficacy of ceritinib against planktonic and persistent S. aureus by a time-killing kinetics assay. Then, antibiofilm effect of ceritinib was assessed by crystal violet staining and laser confocal microscope observation. Ceritinib showed biofilm inhibition and mature biofilm eradication, and possesses robust bactericidal activity against S. aureus persisters. We also evaluated antimicrobial efficacy in vivo using a subcutaneous abscess infection model. Ceritinib ameliorated infection in a subcutaneous abscess mouse model and only showed negligible systemic toxicity in vivo. Mechanism exploration was conducted by transmission electron microscopy, fluorescently labeled giant unilamellar vesicle assays, and a series of fluorescent dyes. In conclusion, we find ceritinib represents potential bactericidal activity against MRSA by disrupting cell membrane integrity and inducing reactive oxygen species production, suggesting ceritinib has the potential to treat MRSA-related infections.
Gametogenetin binding protein 2 (GGNBP2) is an evolutionarily conserved zinc finger protein. Although Ggnbp2-null embryos in the B6 background died because of a defective placenta, 6.8% of Ggnbp2-null mice in the B6/129 mixed background were viable and continued to adulthood. Adult Ggnbp2-null males were sterile, with smaller testes and an azoospermic phenotype, whereas mutant females were fertile. Histopathological analysis of 2-month-old Ggnbp2-null testes revealed absence of mature spermatozoa in the seminiferous tubules and epididymides and reduction of the number of spermatids. Ultrastructural analysis indicated dramatic morphological defects of developing spermatids in the Ggnbp2-null testes, including irregularly shaped acrosomes, acrosome detachment, cytoplasmic remnant, ectopic manchette, and ill-formed head shape in both elongating and elongated spermatids. However, the numbers of spermatogonia, spermatocytes, Leydig cells, and Sertoli cells in Ggnbp2-null testes did not significantly differ from the wild-type siblings. Gonadotropins, testosterone, and the blood-testis barrier were essentially unaffected. Western blot analyses showed increases in α-E-catenin, β-catenin, and N-cadherin, decreases in E-cadherin, afadin, and nectin-3, and no changes in vinculin, nectin-2, focal adhesion kinase, and integrin-β1 protein levels in Ggnbp2-null testes compared to wild-type siblings. Together, this study demonstrates that GGNBP2 is critically required for maintenance of the adhesion integrity of the adlumenal germ epithelium and is indispensable for normal spermatid transformation into mature spermatozoa in mice.
Our knowledge about pathophysiology of intracerebral hemorrhage (ICH) mainly originates from preclinical models of ICH. In this study, cerebral ultrastructure surrounding hematoma and its correlation with clinical severity were investigated in ICH patients. Thirty patients with basal ganglia hemorrhage and 6 control subjects were enrolled. Surgical evacuation was performed for patients with a blood loss >30 ml. Stroke severity was assessed using the Glasgow Coma Scale (GCS) and the National Institute of Health Stroke Scale (NIHSS). Transmission electron microscopy (TEM) was used to evaluate the ultrastructural characteristics of tissue specimens. Neural cells surrounding the hematomas showed evidence of cell swelling and necrosis. Decreased numbers of organelles and mitochondrial cristae were accompanied by cytoplasmic vacuolization, nuclear membrane invagination and breakdown, and intranuclear chromatic agglutination. These changes resulted in disintegration together with malacia, disappearance of the nucleus and nucleolus, and karyopyknosis. More serious ultrastructural damage was seen in patients with greater NIHSS scores, lower GCS scores, and greater bleeding volumes (p < 0.001). These findings suggest that neural cells undergo unfavorable ultrastructural changes that are responsible for dysfunction after ICH.
Diarrhea is among the top five causes of morbidity and mortality in children. Dysbiosis of the gut microbiota is considered the most important risk factor for diarrhea. Prebiotics have shown efficacy in treating diarrhea by regulating the balance of the gut microbiota in vivo.In this study, we used an in vitro fermentation system to prevent the interference of host-gut microbe interactions during in vivo examination and investigated the effect of fructo-oligosaccharides (FOS) on gut microbiota composition and metabolism in 39 pediatric patients with functional diarrhea.16S rRNA sequencing revealed that FOS significantly improved α- and β-diversity in volunteers with pediatric diarrhea (p < 0.05). This improvement manifested as a significant increase (LDA > 2, p < 0.05) in probiotic bacteria (e.g., Bifidobacterium) and a significant inhibition (LDA > 2, p < 0.05) of harmful bacteria (e.g., Escherichia-Shigella). Notably, the analysis of bacterial metabolites after FOS treatment showed that the decrease in isobutyric acid, isovaleric acid, NH3, and H2S levels was positively correlated with the relative abundance of Lachnoclostridium. This decrease also showed the greatest negative correlation with the abundance of Streptococcus. Random forest analysis and ROC curve validation demonstrated that gut microbiota composition and metabolites were distinct between the FOS treatment and control groups (area under the curve [AUC] > 0.8). Functional prediction using PICRUSt 2 revealed that the FOS-induced alteration of gut microbiota was most likely mediated by effects on starch and sucrose metabolism.This study is the first to evince that FOS can modulate gut microbial disorders in children with functional diarrhea. Our findings provide a framework for the application of FOS to alleviate functional diarrhea in children and reduce the use of antibiotics for managing functional diarrhea-induced disturbances in the gut microbiota.
The gut microbiota plays a crucial role in childhood obesity, and diet is a dominating driver. The effects of fructo-oligosaccharides (FOS), as a dietary fiber, on the composition and metabolism of gut microbiota in healthy children was investigated by vitro fermentation system with a reformative YCFA medium (rich in tryptic hydrolysates of meat). The 16S rRNA sequencing technology was utilized to analyze the varieties of gut microbiota. Measurement of short chain fatty acids (SCFAs) and gases were used by the gas chromatograph. Majorbio Cloud Platform and MetOrigin, as the interactive cloud server, perform the microbiota analysis, the metabolic pathway enrichment analysis, the statistical correlations, and biological relationships using network visualization. We found that the FOS group significantly regulated the composition and metabolism of gut microbiota. The co-metabolism network showed that 3 metabolites were related to 6 differential bacteria and 8 metabolism pathways. These findings suggest that dietary fiber could regulate the composition of gut microbiota and its metabolites in a better direction, but when dietary fiber participates in precision nutrition formula, it may be relevant for precision obesity, may help identify windows of opportunity for the dietary intervention of childhood obesity.
Abstract Osteoarthritis is a common chronic degenerative disease, of which the essence is the degenerative changes of bone and joint cartilage, involving damage in multiple structures such as bone, synovium and joints. In the mechanism of arthritis inflammation is closely related, and therefore the exploration to inhibit inflammatory mediators is crucial for the clinical prevention and treatment of osteoarthritis. Inotodiol is a lanostane triterpenoid isolated from Inonotus obliquus, which had been extensively reported to be an anti-inflammatory agent, but its effect on arthritis remains unknown. In this study, we firstly demonstrated that inotodiol significantly reduced IL-1β-induced chondrocyte injury and inhibited the release of inflammatory factors. At the same time, experiments in vivo showed that inotodiol could effectively improve the symptoms of joint injury in mice and reduce the area of cartilage destruction, indicating that inotodiol may be a potential therapeutic drug for osteoarthritis.
Cell death and inflammation in the proximal tubules are the hallmarks of cisplatin-induced AKI, but the mechanisms underlying these effects have not been fully elucidated. Here, we investigated whether necroptosis, a type of programmed necrosis, has a role in cisplatin-induced AKI. We found that inhibition of any of the core components of the necroptotic pathway—receptor-interacting protein 1 (RIP1), RIP3, or mixed lineage kinase domain-like protein (MLKL)—by gene knockout or a chemical inhibitor diminished cisplatin-induced proximal tubule damage in mice. Similar results were obtained in cultured proximal tubular cells. Furthermore, necroptosis of cultured cells could be induced by cisplatin or by a combination of cytokines (TNF-α, TNF-related weak inducer of apoptosis, and IFN-γ) that were upregulated in proximal tubules of cisplatin-treated mice. However, cisplatin induced an increase in RIP1 and RIP3 expression in cultured tubular cells in the absence of cytokine release. Correspondingly, overexpression of RIP1 or RIP3 enhanced cisplatin-induced necroptosis in vitro. Notably, inflammatory cytokine upregulation in cisplatin-treated mice was partially diminished in RIP3- or MLKL-deficient mice, suggesting a positive feedback loop involving these genes and inflammatory cytokines that promotes necroptosis progression. Thus, our data demonstrate that necroptosis is a major mechanism of proximal tubular cell death in cisplatin-induced nephrotoxic AKI.