Neutralization of IL-17 and treatment with IL-2 protects septic arthritis by regulating free radical production and antioxidant enzymes in Th17 and Tregs: An immunomodulatory TLR2 versus TNFR response

Vitexin along with verapamil downregulates efflux pump P-glycoprotein in macrophages and potentiate M1 to M2 switching via TLR4-NF-κB-TNFR2 pathway in lipopolysaccharide treated mice

The lipopolysaccharide, a microbial toxin, is one of the major causative agents of sepsis. P-gp expression and its functions are altered during inflammation. LPS has been known to impair the functions of P-gp, an efflux transporter. But the effect of LPS on P-gp expression in murine peritoneal macrophages is poorly understood. Molecular docking studies reveal that vitexin is a potent substrate and verapamil a potent inhibitor of P-gp. In the present experimental study, the curative potential of vitexin as a fruit component and verapamil treated as a control inhibitor of P-gp was examined in a murine LPS sepsis model. The effects of vitexin and verapamil on P-gp expression in macrophages correlating with changes in macrophage polarization and associated functional responses during LPS induced sepsis were studied. Peritoneal macrophages of LPS (10 mg/kg body weight) challenged mice exhibited elevated levels of H2O2, superoxide, and NO in parallel with lower antioxidant activity. LPS treatment increased P-gp expression through increased TLR4/expression. However, LPS challenged mice treated with vitexin (5 mg/kg body weight) + verapamil (5 mg/kg body weight) showed higher anti-oxidant enzyme activity (SOD, CAT and GRx) resulting in reduced oxidative stress. This combination treatment also elevated TNFR2, concomitant with down-regulation of TLR4, NF-κB and P-gp expression in murine peritoneal macrophages, resulting in a switch from M1 to M2 polarisation of macrophages and reduced inflammatory responses. In conclusion, combined vitexin and verapamil treatment could be used as a promising therapy to regulate P-gp expression and protection against LPS mediated sepsis and inflammatory damages.

Alisol B 23-acetate broadly inhibits coronavirus through blocking virus entry and suppresses proinflammatory T cells responses for the treatment of COVID-19

INTRODUCTION

Emerging severe acute respiratory syndrome (SARS) coronavirus (CoV)-2 causes a global health disaster and pandemic. Seeking effective anti-pan-CoVs drugs benefit critical illness patients of coronavirus disease 2019 (COVID-19) but also may play a role in emerging CoVs of the future.

OBJECTIVES

This study tested the hypothesis that alisol B 23-acetate could be a viral entry inhibitor and would have proinflammatory inhibition for COVID-19 treatment.

METHODS

SARS-CoV-2 and its variants infected several cell lines were applied to evaluate the anti-CoVs activities of alisol B 23-aceate in vitro. The effects of alisol B 23-acetate on in vivo models were assessed by using SARS-CoV-2 and its variants challenged hamster and human angiotensin-converting enzyme 2 (ACE2) transgenic mice. The target of alisol B 23-acetate to ACE2 was analyzed using hydrogen/deuterium exchange (HDX) mass spectrometry (MS).

RESULTS

Alisol B 23-acetate had inhibitory effects on different species of coronavirus. By using HDX-MS, we found that alisol B 23-acetate had inhibition potency toward ACE2. In vivo experiments showed that alisol B 23-acetate treatment remarkably decreased viral copy, reduced CD4+ T lymphocytes and CD11b+ macrophages infiltration and ameliorated lung damages in the hamster model. In Omicron variant infected human ACE2 transgenic mice, alisol B 23-acetate effectively alleviated viral load in nasal turbinate and reduced proinflammatory cytokines interleukin 17 (IL17) and interferon γ (IFNγ) in peripheral blood. The prophylactic treatment of alisol B 23-acetate by intranasal administration significantly attenuated Omicron viral load in the hamster lung tissues. Moreover, alisol B 23-acetate treatment remarkably inhibited proinflammatory responses through mitigating the secretions of IFNγ and IL17 in the cultured human and mice lymphocytes in vitro.

CONCLUSION

Alisol B 23-acetate could be a promising therapeutic agent for COVID-19 treatment and its underlying mechanisms might be attributed to viral entry inhibition and anti-inflammatory activities.

The multiple biotoxicity integrated study in grass carp (Ctenopharyngodon idella) caused by Ochratoxin A: Oxidative damage, apoptosis and immunosuppression

Ochratoxin A (OTA) is a common hazardous food contaminant that seriously endangers human and animal health. However, limited study is focused on aquatic animal. This research investigated the multiple biotoxicity of OTA on spleen (SP) and head kidney (HK) in grass carp and its related mechanism. Our data showed that, dietary supplemented with OTA above 1209 μg/kg caused histopathological damages by decreasing the number of lymphocytes and necrotizing renal parenchymal cells. Meanwhile, OTA caused oxidative damage and reduced the isoforms mRNAs transcripts of antioxidant enzymes (e.g., GPX1, GPX4, GSTO) partly due to suppressing NF-E2-related factor 2 (Nrf2). OTA triggered apoptosis through mitochondria and death receptor pathway potentially by p38 mitogen-activated protein kinase (p38MAPK) activation. Besides, OTA exacerbated inflammation by down-regulation of anti-inflammatory factor (e.g., IL-10, IL-4) and up-regulations of pro-inflammatory factors (e.g., TNF-α, IL-6), which could be ascribed to signaling meditation of Janus kinase / signal transducer and activator of transcription (JAK/STAT). Additionally, the safe upper limits of OTA were estimated to be 677.6 and 695.08 μg/kg based on the immune-related indexes (C3 contents in the SP and LZ activities in the HK, respectively). Our study has provided a wide insight for toxicological assessment of feed pollutant in aquatic animals.

Isomaltulose alleviates acute colitis via modulating gut microbiota and the Treg/Th17 balance in mice

Food-grade isomaltulose exhibits significant modulation of gut microbiota and its metabolites in healthy populations. This study further explored the preventive therapeutic effect and anti-colitis potential of isomaltulose on dextran sulfate sodium-induced colitis in mice. Our results suggested that isomaltulose played a significant role in preventing colon shortening, reducing intestinal epithelial destruction and inhibiting inflammatory cell infiltration. Meanwhile, the isomaltulose supplement greatly reduced the production of pro-inflammatory cytokines and restored the balance between T helper type 17 (Th17) cells and regulatory T (Treg) cells. Pathway enrichment analysis for differentially expressed genes (DEGs) also indicated that the anti-inflammatory effect of isomaltulose was closely related to intestinal immunity. Moreover, the disturbed gut microbiota in ulcerative colitis (UC) was partially restored after treatment with isomaltulose. These results suggest that isomaltulose is a promising therapeutic agent for the prevention and adjunctive treatment of UC by maintaining intestinal immune homeostasis and remodeling the gut microbiota.

Exploring the Role of Staphylococcus aureus in Inflammatory Diseases

Staphylococcus aureus is a very common Gram-positive bacterium, and S. aureus infections play an extremely important role in a variety of diseases. This paper describes the types of virulence factors involved, the inflammatory cells activated, the process of host cell death, and the associated diseases caused by S. aureus. S. aureus can secrete a variety of enterotoxins and other toxins to trigger inflammatory responses and activate inflammatory cells, such as keratinocytes, helper T cells, innate lymphoid cells, macrophages, dendritic cells, mast cells, neutrophils, eosinophils, and basophils. Activated inflammatory cells can express various cytokines and induce an inflammatory response. S. aureus can also induce host cell death through pyroptosis, apoptosis, necroptosis, autophagy, etc. This article discusses S. aureus and MRSA (methicillin-resistant S. aureus) in atopic dermatitis, psoriasis, pulmonary cystic fibrosis, allergic asthma, food poisoning, sarcoidosis, multiple sclerosis, and osteomyelitis. Summarizing the pathogenic mechanism of Staphylococcus aureus provides a basis for the targeted treatment of Staphylococcus aureus infection.