Cordyceps militaris Immunomodulatory Protein Promotes the Phagocytic Ability of Macrophages through the TLR4-NF-κB Pathway

Adipose mesenchymal stem cells-derived exosomes attenuated hyperoxia-induced lung injury in neonatal rats via inhibiting the NF-κB signaling pathway

OBJECTIVE

Bronchopulmonary dysplasia (BPD) is the most common chronic morbidity in extremely preterm infants. Mesenchymal stem cells-derived exosomes (MSC-Exos) therapies have shown prospects in animal models of BPD. Our study aimed to evaluate the effect of adipose mesenchymal stem cells-derived exosomes (AMSC-Exos) on BPD and the role of the NF-κB signaling pathway in this process.

METHODS

The AMSCs were extracted and AMSC-Exos were isolated by ultracentrifugation method. Newborn rats were exposed to hyperoxia (90% O2) continuously for 7 days to establish a BPD model. The rats were treated with AMSC-Exos by intratracheal administration on postnatal day 4 (P4). Pulmonary morphology, pulmonary vasculature, inflammatory factors, and NF-κB were assessed. Hyperoxia-induced primary type II alveolar epithelial cells (AECIIs) and AMSC-Exos treatment with or without a pan-NF-κB inhibitor (PDTC) were established to explore the potential mechanism.

RESULTS

Hyperoxia-exposed rats showed alveolar simplification with decreased radial alveolar count and increased mean linear intercept, low CD31, and vascular endothelial growth factor expression, reduced microvessel density, increased the expression of TNF-α, IL-1β, and IL-6 and decreased the expression of IL-10, and induced NF-κB phosphorylation. AMSC-Exos protected the neonatal lung from the hyperoxia-induced arrest of alveolar and vascular development, alleviated inflammation, and inhibited NF-κB phosphorylation. Hyperoxia decreased viability, increased apoptosis, enhanced inflammation, and induced NF-κB phosphorylation of AECIIs but improved by AMSC-Exos, PDTC, or AMSC-Exos+PDTC. The effect of AMSC-Exos+PDTC in AECIIs was the same as AMSC-Exos, but more notable than PDTC alone.

CONCLUSION

AMSC-Exos attenuated the hyperoxia-induced lung injury in neonatal rats by inhibiting the NF-κB signaling pathway partly.

The effect of herbal medicine in innate immunity to Candida albicans

Candida albicans (C. albicans) is an opportunistic pathogenic fungus that often causes mucosal and systemic infections. Several pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), have been implicated in the host recognition of C. albicans. These PRRs recognize the pathogen-associated molecular patterns (PAMPs) of C. albicans to activate innate immune cells, thereby rapidly inducing various inflammatory responses by activating intracellular signaling cascades. Herbal medicine and its active components deserve priority development due to their low toxicity and high antibacterial, antiviral and antifungal activities. This review discussed the activities of herbal compounds against C. albicans and their related mechanisms, especially their regulatory role on innate immune cells such as neutrophils, macrophages, and dendritic cells (DCs) implicated in C. albicans infections. Our work aims to find new therapeutic drugs and targets to prevent and treat diseases caused by C. albicans infection with the mechanisms by which this fungus interacts with the innate immune response.

Immunomodulatory effects of Abelmoschus esculentus water extract through MAPK and NF-κB signaling in RAW 264.7 cells

During the current COVID-19 pandemic, the world is facing a new, highly contagious virus that suppresses innate immunity as one of its early virulence mechanisms. Therefore, finding new methods to enhance innate immunity is a promising strategy to attenuate the effects of this major global health problem. With the aim of characterizing bioactive ingredients as immune-enhancing agents, this study focuses on Abelmoschus esculentus (okra), which has several previously demonstrated bioactivities. Firstly, we investigated the immune-stimulatory effects of okra leaf ethanol extract (OLE) and okra leaf water extract (OLW) on nitric oxide (NO) production in macrophages. OLE significantly decreased nitrite accumulation in LPS-stimulated RAW 264.7 cells, indicating that it potentially inhibited NO production in a concentration-dependent manner. In contrast, OLW significantly enhanced the production of prostaglandin E₂ (PGE₂), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and NO in a dose-dependent manner. OLW also increased the expression levels of NO synthase (iNOS) and cyclooxygenase (COX)-2, potentially explaining the OLW-induced increase in NO and PGE₂ production. In addition, OLW stimulated the phosphorylation of mitogen-activated protein kinases (MAPKs; ERK, p38, and JNK) as well as the activation and subsequent nuclear translocation of nuclear factor κB (NF-κB). This indicated that OLW activates macrophages to secrete PGE₂, TNF-α, IL-1β, and NO, inducing iNOS and COX-2 expression via activation of the NF-κB and MAPK signaling pathways. In conclusion, our results demonstrate that OLW can effectively promote the activation of macrophages, suggesting that OLW may possess potent immunomodulatory effects and should be explored as a potential health-promoting materials to boost the immune system.