Immunomodulatory effects of hydatid antigens on mesenchymal stem cells: gene expression alterations and functional consequences.

Background: Cystic echinococcosis, caused by the larval stage of Echinococcus granulosus, remains a global health challenge. Mesenchymal stem cells (MSCs) are renowned for their regenerative and immunomodulatory properties. Given the parasite's mode of establishment, we postulate that MSCs likely play a pivotal role in the interaction between the parasite and the host. This study aims to explore the response of MSCs to antigens derived from Echinococcus granulosus, the etiological agent of hydatid disease, with the hypothesis that exposure to these antigens may alter MSC function and impact the host's immune response to the parasite. Methods: MSCs were isolated from mouse bone marrow and co-cultured with ESPs, HCF, or pLL antigens. We conducted high-throughput sequencing to examine changes in the MSCs' mRNA expression profile. Additionally, cell cycle, migration, and secretory functions were assessed using various assays, including CCK8, flow cytometry, real-time PCR, Western blot, and ELISA. Results: Our analysis revealed that hydatid antigens significantly modulate the mRNA expression of genes related to cytokine and chemokine activity, impacting MSC proliferation, migration, and cytokine secretion. Specifically, there was a downregulation of chemokines (MCP-1, CXCL1) and pro-inflammatory cytokines (IL-6, NOS2/NO), alongside an upregulation of anti-inflammatory mediators (COX2/PGE2). Furthermore, all antigens reduced MSC migration, and significant alterations in cellular metabolism-related pathways were observed. Conclusion: Hydatid disease antigens induce a distinct immunomodulatory response in MSCs, characterized by a shift towards an anti-inflammatory phenotype and reduced cell migration. These changes may contribute to the parasite's ability to evade host defenses and persist within the host, highlighting the complex interplay between MSCs and hydatid disease antigens. This study provides valuable insights into the pathophysiology of hydatid disease and may inform the development of novel therapeutic strategies.

Exploration of altered miRNA expression and function in MSC-derived extracellular vesicles in response to hydatid antigen stimulation.

Background: Hydatid disease is caused by Echinococcus parasites and can affect various tissues and organs in the body. The disease is characterized by the presence of hydatid cysts, which contain specific antigens that interact with the host's immune system. Mesenchymal stem cells (MSCs) are pluripotent stem cells that can regulate immunity through the secretion of extracellular vesicles (EVs) containing microRNAs (miRNAs). Methods: In this study, hydatid antigens were isolated from sheep livers and mice peritoneal cavities. MSCs derived from mouse bone marrow were treated with different hydatid antigens, and EVs were isolated and characterized from the conditioned medium of MSCs. Small RNA library construction, miRNA target prediction, and differential expression analysis were conducted to identify differentially expressed miRNAs. Functional enrichment and network construction were performed to explore the biological functions of the target genes. Real-time PCR and Western blotting were used for miRNA and gene expression verification, while ELISA assays quantified TNF, IL-1, IL-6, IL-4, and IL-10 levels in cell supernatants. Results: The study successfully isolated hydatid antigens and characterized MSC-derived EVs, demonstrating the impact of antigen concentration on MSC viability. Key differentially expressed miRNAs, such as miR-146a and miR-9-5p, were identified, with functional analyses revealing significant pathways like Endocytosis and MAPK signaling associated with these miRNAs' target genes. The miRNA-HUB gene regulatory network identified crucial miRNAs and HUB genes, such as Traf1 and Tnf, indicating roles in immune modulation and osteogenic differentiation. Protein-protein interaction (PPI) network analysis highlighted central HUB genes like Akt1 and Bcl2. ALP activity assays confirmed the influence of antigens on osteogenic differentiation, with reduced ALP activity observed. Expression analysis validated altered miRNA and chemokine expression post-antigen stimulation, with ELISA analysis showing a significant reduction in CXCL1 expression in response to antigen exposure. Conclusion: This study provides insights into the role of MSC-derived EVs in regulating parasite immunity. The findings suggest that hydatid antigens can modulate the expression of miRNAs in MSC-derived EVs, leading to changes in chemokine expression and osteogenic capacity. These findings contribute to a better understanding of the immunomodulatory mechanisms involved in hydatid disease and provide potential therapeutic targets for the development of new treatment strategies.

Isoflavones isolated from chickpea sprouts alleviate ovariectomy-induced osteoporosis in rats by dual regulation of bone remodeling.

Osteoporosis is a common systemic skeletal disease and a predominant underlying factor in the increased occurrence of fractures. The structure of isoflavones resembles that of estrogen and can confer similar but weaker effects. This study investigated the potential inhibitory effects of isoflavones from chickpea sprouts (ICS) on ovariectomy (OVX)-induced osteoporosis in vitro and in vivo. Notably, we found that ICS treatment could attenuate bone loss and improve trabecular microarchitecture and biomechanical properties of the fourth lumbar vertebra in OVX-induced osteoporotic rats and could also inhibit the development of a hyperosteometabolic state in this model. The osteogenic differentiation of bone marrow stem cells (BMSCs) was significantly enhanced by ICS intervention in vitro, and we confirmed that estrogen receptor α signaling was required for this increased osteogenic differentiation. Additionally, ICS has been shown to inhibit bone resorption via ERa modulation of the OPG/RANKL pathway. RANKL-induced osteoclastogenesis was reduced under ICS treatment, supporting that NF-κB signaling was inhibited by ICS. Thus, ICS attenuates osteoporosis progression by promoting osteogenic differentiation and inhibiting osteoclastic resorption. These results support the further exploration and development of ICS as a pharmacological agent for the treatment and prevention of osteoporosis.

Regulation of Toll-like receptors on function of osteoblasts and osteoclasts / 中国组织工程研究

BACKGROUND:Toll-like receptors are an important class of pattern recognition receptors that have important functions in pathogen immunity and cytokine synthesis by recognizing specific molecular patterns.Previous studies have found that different types of bone tissue cells also express Toll-like receptors.Activation or inhibition of Toll-like receptors can have significant effects on osteoblast and osteoclast function through multiple pathways. OBJECTIVE:To summarize the expression and action pathways of Toll-like receptors in osteoblasts and osteoclasts,in order to further elucidate the biological mechanisms involved in the regulation of Toll-like receptors under physiological and pathological conditions. METHODS:Relevant literature was retrieved from databases such as PubMed and CNKI as of December 2022.The Chinese and English search terms included"Toll-like receptor,osteoblast,osteoclast,mesenchymal stem cells,macrophage,cytokine,signaling pathway".According to the research needs,the corresponding criteria were established to screen the final literature. RESULTS AND CONCLUSION:(1)Toll-like receptors could directly regulate osteoblast and osteoclast differentiation through the activation of related signaling pathways.(2)Toll-like receptor activation induces cytokine production and exerts regulatory effects.(3)Toll-like receptor activation can affect the survival and migration ability of osteoblasts and osteoclasts.(4)Toll-like receptors in osteoblasts and osteoclasts are activated in certain diseases and pathological settings and are involved in intercellular interactions.

Regulation of bone tissue cells by tumor necrosis factor-alpha / 中国组织工程研究

BACKGROUND:Tumor necrosis factor-α is a broadly acting inflammatory cytokine that plays an important role in the immune inflammatory response of the body.The current study concluded that tumor necrosis factor-α has significant biological effects on a variety of bone tissue cells. OBJECTIVE:To summarize the expression and action pathways of tumor necrosis factor-α in osteoblastic and osteoclastic cells to further elucidate the regulatory role of tumor necrosis factor-α on bone tissue cells. METHODS:PubMed and CNKI were searched until March 2023,and the Chinese search terms included"tumor necrosis factor α,osteoblast,osteoclast,osteoclast,osteoprogenitor";the English search terms included"TNF-α,osteoblast,osteoclast,osteocyte,osteoprogenitor cell".The corresponding criteria were established according to the research needs,and the final literature was screened.Finally,77 articles were included for review. RESULTS AND CONCLUSION:(1)Tumor necrosis factor-α is participating in regulating the recruitment,appreciation,and differentiation of osteoprogenitor cells,but leads to osteoprogenitor cell stripping and death under specific environments.It also participates in bone resorption directly or indirectly through secreted enzymes.(2)Tumor necrosis factor-α can increase the level of inflammatory factors in the environment by activating relevant signaling pathways in osteoclast lineage cells or directly induce the generation of osteoclasts in specific environments.(3)Tumor necrosis factor-α can inhibit osteogenic differentiation by activating nuclear factor-κB signaling pathway,inhibiting the expression of transcription factors such as RUNX2 and Osterix,and inducing apoptosis and necrotizing apoptosis in osteoblasts.(4)Tumor necrosis factor-α inhibits osteogenesis and promotes osteoclastogenesis by activating the nuclear factor-κB signaling pathway in osteocytes and inducing cytokines such as RANKL,SOST,and DKK1,while enhancing apoptosis of the osteocytes,as well as bone resorption around the apoptotic bone tissue.(5)Taken together,the effect of tumor necrosis factor-α in bone tissue is mainly to inhibit osteogenesis and promote osteoclastosis.The biological effect of tumor necrosis factor-α in bone tissue cells is usually dependent on the activation of tumor necrosis factor receptor and nuclear factor-κB signaling pathways.(6)The interaction of tumor necrosis factor-α with other tissue cell types surrounding bone tissue and its role in bone immune regulation still deserve attention in future studies.