Alteration of the gut microbiota in rhesus monkey with spontaneous osteoarthritis

Knee osteoarthritis: A review of animal models and intervention of traditional Chinese medicine

BACKGROUND

Knee osteoarthritis (KOA) characterized by degeneration of knee cartilage and subsequent bone hyperplasia is a prevalent joint condition primarily affecting aging adults. The pathophysiology of KOA remains poorly understood, as it involves complex mechanisms that result in the same outcome. Consequently, researchers are interested in studying KOA and require appropriate animal models for basic research. Chinese herbal compounds, which consist of multiple herbs with diverse pharmacological properties, possess characteristics such as multicomponent, multipathway, and multitarget effects. The potential benefits in the treatment of KOA continue to attract attention.

PURPOSE

This study aims to provide a comprehensive overview of the advantages, limitations, and specific considerations in selecting different species and methods for KOA animal models. This will help researchers make informed decisions when choosing an animal model.

METHODS

Online academic databases (e.g., PubMed, Google Scholar, Web of Science, and CNKI) were searched using the search terms "knee osteoarthritis," "animal models," "traditional Chinese medicine," and their combinations, primarily including KOA studies published from 2010 to 2023.

RESULTS

Based on literature retrieval, this review provides a comprehensive overview of the methods of establishing KOA animal models; introduces the current status of advantages and disadvantages of various animal models, including mice, rats, rabbits, dogs, and sheep/goats; and presents the current status of methods used to establish KOA animal models.

CONCLUSION

This study provides a review of the animal models used in recent KOA research, discusses the common modeling methods, and emphasizes the role of traditional Chinese medicine compounds in the treatment of KOA.

Efficacy and mechanism study of Baichanting compound, a combination of Acanthopanax senticosus (Rupr. and Maxim.) Harms, Paeonia lactiflora Pall and Uncaria rhynchophylla (Miq.) Miq. ex Havil, on Parkinson's disease based on metagenomics and metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

Parkinson's disease (PD) is a rapidly progressing neurological disorder. Currently, Medication for PD has numerous limitations. Baichanting Compound (BCT) is a Chinese herbal prescription, a Combination of Acanthopanax senticosus (Rupr. and Maxim.) Harms, Paeonia lactiflora Pall and Uncaria rhynchophylla (Miq.) Miq. ex Havil, that was developed to treat PD and holds a national patent (ZL, 201110260536.3).

AIM OF THE STUDY

To clarify the therapeutic effect of BCT on PD and explore its possible mechanism based on metabolomics and metagenomics.

MATERIALS AND METHODS

C57BL/6 mice were used as a control group, and α-syn transgenic C57BL/6 mice were randomly assigned to the PD (without treatment) or BCT (with BCT treatment) group. UPLC-MS was performed to detect dopamine levels in brain tissue, while ELISA was used to determine inflammatory factors such as IL-1β, IL-6, TNF-α, IFN-γ and NO, and oxidative stress indicators such as malondialdehyde, superoxide dismutase and glutathione peroxidase enzyme activity. Fecal metabolomics was used to detect fecal metabolic profiles, screen differential metabolic markers, and predict metabolic pathways by KEGG enrichment analysis. Metagenomics was used to determine the intestinal microbial composition, and KO enrichment analysis was performed to predict the potential function of different gut microbiota. Finally, Spearman correlation analysis was used to find the possible relationships among intestinal flora, metabolic markers, inflammatory factors, oxidative stress and dopamine levels.

RESULTS

BCT increased the superoxide dismutase activity of α-Syn transgenic C57BL/6 mice (P < 0.01), decreased the levels of TNF-α, IFN-γ, IL-1β, IL-6, NO and malondialdehyde (P < 0.01, 0.05), and increased the release of dopamine (P < 0.01). Metabolomics results show that BCT could regulate Acetatifactor, Marvinbryantia, Faecalitalea, Anaeromassilibacillus, Anaerobium, Pseudobutyrivibrio and Lachnotalea and Acetatifactor_muris, Marvinbryantia_formatexigens, Lachnotalea_sp_AF33_28, Faecalitalea_sp_Marseille_P3755 and Anaerobium_acetethylicum, Gemmiger_sp_An120 abundance to restore intestinal flora function, and reverse fecal metabolism trend, restoring the content of α-D-glucose, cytidine, L-glutamate, L-glutamine, N-acetyl-L-glutamate, raffinose and uracil. In addition, it regulates arginine biosynthesis, D-glutamine and D-glutamate, pyrimidine, galactose and alanine, aspartate and glutamate metabolic pathways.

CONCLUSION

BCT may regulate the composition of the gut microbiota to reverse fecal metabolism in PD mice to protect the substantia nigra and striatum from oxidative stress and inflammatory factors and ultimately play an anti-PD role.

The Complex Interplay between the Gut Microbiome and Osteoarthritis: A Systematic Review on Potential Correlations and Therapeutic Approaches

The objective of this review is to systematically analyze the potential correlation between gut microbiota and osteoarthritis (OA) as well as to evaluate the feasibility of microbiota-targeted therapies for treating OA. Studies conducted from October 2013 to October 2023 were identified via a search on electronic databases such as PubMed, Web of Science, and Scopus, following established PRISMA statement standards. Two reviewers independently screened, assessed, and extracted relevant data, and then they graded the studies using the ROBINS I tool for non-randomized interventions studies and SYRCLE's risk-of-bias tool for animal studies. A search through 370 studies yielded 38 studies (24 preclinical and 14 clinical) that were included. In vivo research has predominantly concentrated on modifying the gut microbiota microenvironment, using dietary supplements, probiotics, and prebiotics to modify the OA status. Lactobacilli are the most thoroughly examined with Lactobacillus acidophilus found to effectively reduce cartilage damage, inflammatory factors, and pain. Additionally, Lactobacillus M5 inhibits the development of OA by preventing high-fat diet (HFD)-induced obesity and protecting cartilage from damage. Although there are limited clinical studies, certain compositions of intestinal microbiota may be associated with onset and progression of OA, while others are linked to pain reduction in OA patients. Based on preclinical studies, there is evidence to suggest that the gut microbiota could play a significant role in the development and progression of OA. However, due to the scarcity of clinical studies, the exact mechanism linking the gut microbiota and OA remains unclear. Further research is necessary to evaluate specific gut microbiota compositions, potential pathogens, and their corresponding signaling pathways that contribute to the onset and progression of OA. This will help to validate the potential of targeting gut microbiota for treating OA patients.

The gut-joint axis mediates the TNF-induced RA process and PBMT therapeutic effects through the metabolites of gut microbiota

The gut-joint axis, one of the mechanisms that mediates the onset and progression of joint and related diseases through gut microbiota, and shows the potential as therapeutic target. A variety of drugs exert therapeutic effects on rheumatoid arthritis (RA) through the gut-joint axis. However, the anti-inflammatory and immunomodulatory effect of novel photobiomodulatory therapy (PBMT) on RA need further validation and the involvement of gut-joint axis in this process remains unknown. The present study demonstrated the beneficial effects of PBMT on RA, where we found the restoration of gut microbiota homeostasis, and the related key pathways and metabolites after PBMT. We also discovered that the therapeutic effects of PBMT on RA mainly through the gut-joint axis, in which the amino acid metabolites (Alanine and N-acetyl aspartate) play the key role and rely on the activity of metabolic enzymes in the target organs. Together, the results prove that the metabolites of amino acid from gut microbiota mediate the regulation effect on the gut-joint axis and the therapeutic effect on rheumatoid arthritis of PBMT.

"Cross-talk" between gut microbiome dysbiosis and osteoarthritis progression: a systematic review

Objectives

The aim of this systematic review was to summarize the available literature on gut microbiome (GMB) and osteoarthritis (OA), analyze the correlation between GMB and OA, and explore potential underlying mechanisms.

Methods

A systematic search of the PubMed, Embase, Cochrane, and Web of Science with the keywords "Gut Microbiome" and "Osteoarthritis" was conducted to identify the human and animal studies exploring the association between GMB and OA. The retrieval time range was from the database inception to July 31, 2022. Studies reported the other arthritic diseases without OA, reviews, and studies focused on the microbiome in other parts of the body with OA, such as oral or skin, were excluded. The included studies were mainly reviewed for GMB composition, OA severity, inflammatory factors, and intestinal permeability.

Results

There were 31 studies published met the inclusion criteria and were analyzed, including 10 human studies and 21 animal studies. Human and animal studies have reached a consistent conclusion that GMB dysbiosis could aggravate OA. In addition, several studies have found that alterations of GMB composition can increase intestinal permeability and serum levels of inflammatory factors, while regulating GMB can alleviate the changes. Owing to the susceptibility of GMB to internal and external environments, genetics, and geography, the included studies were not consistent in GMB composition analysis.

Conclusion

There is a lack of high-quality studies evaluating the effects of GMB on OA. Available evidence indicated that GMB dysbiosis aggravated OA through activating the immune response and subsequent induction of inflammation. Future studies should focus on more prospective, cohort studies combined with multi-omics to further clarify the correlation.

Oral Administration of Bovine Milk-Derived Extracellular Vesicles Attenuates Cartilage Degeneration via Modulating Gut Microbiota in DMM-Induced Mice

Osteoarthritis (OA) is the most common joint disease primarily characterized by cartilage degeneration. Milk-derived extracellular vesicles (mEVs) were reported to inhibit catabolic and inflammatory processes in the cartilage of OA patients. However, the current therapies target the advanced symptoms of OA, and it is significant to develop a novel strategy to inhibit the processes driving OA pathology. In this study, we investigated the therapeutic potential of mEVs in alleviating OA in vivo. The results revealed that mEVs ameliorated cartilage degeneration by increasing hyaline cartilage thickness, decreasing histological Osteoarthritis Research Society International (OARSI) scores, enhancing matrix synthesis, and reducing the expression of cartilage destructive enzymes in the destabilization of medial meniscus (DMM) mice. In addition, the disturbed gut microbiota in DMM mice was partially improved upon treatment with mEVs. It was observed that the pro-inflammatory bacteria (Proteobacteria) were reduced and the potential beneficial bacteria (Firmicutes, Ruminococcaceae, Akkermansiaceae) were increased. mEVs could alleviate the progression of OA by restoring matrix homeostasis and reshaping the gut microbiota. These findings suggested that mEVs might be a potential therapeutic dietary supplement for the treatment of OA.

The mechanism of palmatine-mediated intestinal flora and host metabolism intervention in OA-OP comorbidity rats

Background

ErXian decoction is a Chinese herbal compound that can prevent and control the course of osteoarthritis (OA) and osteoporosis (OP). OP and OA are two age-related diseases that often coexist in elderly individuals, and both are associated with dysregulation of the gut microbiome. In the initial study, Palmatine (PAL) was obtained by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and network pharmacological screening techniques, followed by 16S rRNA sequencing and serum metabolomics of intestinal contents, to explore the mechanism of PAL in the treatment of OA and OP.

Methods

The rats selected for this study were randomly divided into three groups: a sham group, an OA-OP group and a PAL group. The sham group was intragastrically administered normal saline solution, and the PLA group was treated with PAL for 56 days. Through microcomputed tomography (micro-CT), ELISA, 16S rRNA gene sequencing and non-targeted metabonomics research, we explored the potential mechanism of intestinal microbiota and serum metabolites in PAL treatment of OA-OP rats.

Results

Palmatine significantly repair bone microarchitecture of rat femur in OA-OP rats and improved cartilage damage. The analysis of intestinal microflora showed that PAL could also improve the intestinal microflora disorder of OA-OP rats. For example, the abundance of Firmicutes, Bacteroidota, Actinobacteria, Lactobacillus, unclassified_f_Lachnospiraceae, norank_f_Muribaculaceae, Lactobacillaceae, Lachnospiraceae and Muribaculaceae increased after PAL intervention. In addition, the results of metabolomics data analysis showed that PAL also change the metabolic status of OA-OP rats. After PAL intervention, metabolites such as 5-methoxytryptophol, 2-methoxy acetaminophen sulfate, beta-tyrosine, indole-3-carboxylic acid-O-sulfate and cyclodopa glucoside increased. Association analysis of metabolomics and gut microbiota (GM) showed that the communication of multiple flora and different metabolites played an important role in OP and OA.

Conclusion

Palmatine can improve cartilage degeneration and bone loss in OA-OP rats. The evidence we provided supports the idea that PAL improves OA-OP by altering GM and serum metabolites. In addition, the application of GM and serum metabolomics correlation analysis provides a new strategy for uncovering the mechanism of herbal treatment for bone diseases.

Analysis of gut microbiome composition, function, and phenotype in patients with osteoarthritis

Gut microbiome (GMB) disturbance can induce chronic low-grade inflammation, which is closely related to the occurrence and development of osteoarthritis (OA). However, the relationship between GMB and OA remains unclear. In this study, we collected stool samples from OA patients and healthy people, and performed Alpha diversity, Beta diversity, MetaStat, and LEfSe analysis by 16S rRNA sequencing to find out the species with significant difference between the two groups. Random forest analysis was performed to find out biomarkers that could distinguish between OA patients and healthy people. PICRUSt and Bugbase analysis were used to compare the difference in functions and phenotypes. Multivariate linear regression analysis (MaAsLin) was used to adjust for gender, age, and body mass index (BMI). The results showed that there was a significant difference in the overall composition of GMB between the two groups (p = 0.005). After adjusting for gender, age, and BMI, we found that p_Bacteroidota (Q = 0.039), c_Bacteroidia (Q = 0.039), and o_Bacteroidales (Q = 0.040) were enriched in the OA group, while s_Prevotella_copri (Q = 0.001) was enriched in the healthy control group. Prevotella could distinguish between OA patients and healthy people with a better diagnostic power (AUC = 77.5%, p < 0.001, 95% CI: 66.9-88.1%). The functions of DNA transcription, amino acid metabolism (including histidine, lysine, and isoleucine), ATP metabolism, and phospholipid metabolism significantly decreased, while glucose metabolism, protein acetylation, and aspartate kinase activity significantly increased in the OA group. In terms of phenotypes, we found that the relative abundance of aerobic (p = 0.003) and Gram-negative (p < 0.001) was higher in the OA group, while contains mobile elements (p = 0.001) and Gram-positive (p < 0.001) were higher in the healthy control group. Our study preliminarily demonstrated that there were differences in the composition, function, and phenotype of GMB in stool samples between OA patients and healthy people, which provided a novel perspective on further study in OA.

The effects and significance of gut microbiota and its metabolites on the regulation of osteoarthritis: Close coordination of gut-bone axis

Osteoarthritis (OA) is a common chronic degenerative disease of articular cartilage in middle-aged and older individuals, which can result in the joint pain and dysfunction, and even cause the joint deformity or disability. With the enhancing process of global aging, OA has gradually become a major public health problem worldwide. Explaining pathogenesis of OA is critical for the development of new preventive and therapeutic interventions. In recent years, gut microbiota (GM) has been generally regarded as a “multifunctional organ,” which is closely relevant with a variety of immune, metabolic and inflammatory functions. Meanwhile, more and more human and animal researches have indicated the existence of gut-bone axis and suggested that GM and its metabolites are closely involved in the pathogenic process of OA, which might become a potential and promising intervention target. Based on the close coordination of gut-bone axis, this review aims to summarize and discuss the mechanisms of GM and its metabolites influencing OA from the aspects of the intestinal mucosal barrier modulation, intestinal metabolites modulation, immune modulation and strategies for the prevention or treatment of OA based on perspectives of GM and its metabolites, thus providing a profound knowledge and recognition of it.