Expression and Metabolomic Profiling in Axial Spondyloarthritis

Intestinal Microbial Metabolites in Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease characterized by inflammation of axial joints and the pelvis. It is known that intestinal dysbiosis may exert direct pathogenic effects on gut homeostasis and may act as a triggering factor for the host innate immune system to activate and cause inflammation in extraintestinal sites in the so-called "gut-joint axis", contributing to AS pathogenesis. However, although the intestinal microbiota's influence on the clinical manifestation of AS is widely accepted, the mechanisms mediating the cross-talk between the intestinal lumen and the immune system are still not completely defined. Recent evidence suggests that the metabolism of microbial species may be a source of metabolites and small molecules participating in the complex network existing between bacteria and host cells. These findings may give inputs for further research of novel pharmacological targets and pave the way to applying dietary interventions to prevent the onset and ameliorate the clinical presentation of the disease. In this review, we discuss the role of some of the biological mediators of microbial origin, with a particular focus on short-chain fatty acids, tryptophan and vitamin B derivatives, and their role in barrier integrity and type 3 immunity in the context of AS.

Serum Metabolomics Signatures Associated With Ankylosing Spondylitis and TNF Inhibitor Therapy

Ankylosing spondylitis (AS) is a type of spondyloarthropathies, the diagnosis of which is often delayed. The lack of early diagnosis tools often delays the institution of appropriate therapy. This study aimed to investigate the systemic metabolic shifts associated with AS and TNF inhibitors treatment. Additionally, we aimed to define reliable serum biomarkers for the diagnosis. We employed an untargeted technique, ultra-performance liquid chromatography-mass spectroscopy (LC-MS), to analyze the serum metabolome of 32 AS individuals before and after 24-week TNF inhibitors treatment, as well as 40 health controls (HCs). Multivariate and univariate statistical analyses were used to profile the differential metabolites associated with AS and TNF inhibitors. A diagnostic panel was established with the least absolute shrinkage and selection operator (LASSO). The pathway analysis was also conducted. A total of 55 significantly differential metabolites were detected. We generated a diagnostic panel comprising five metabolites (L-glutamate, arachidonic acid, L-phenylalanine, PC (18:1(9Z)/18:1(9Z)), 1-palmitoylglycerol), capable of distinguishing HCs from AS with a high AUC of 0.998, (95%CI: 0.992-1.000). TNF inhibitors treatment could restore the equilibrium of 21 metabolites. The most involved pathways in AS were amino acid biosynthesis, glycolysis, glutaminolysis, fatty acids biosynthesis and choline metabolism. This study characterized the serum metabolomics signatures of AS and TNF inhibitor therapy. We developed a five-metabolites-based panel serving as a diagnostic tool to separate patients from HCs. This serum metabolomics study yielded new knowledge about the AS pathogenesis and the systemic effects of TNF inhibitors.

Metabolomics coupled with integrative pharmacology reveals the therapeutic effect of l-borneolum against cerebral ischaemia in rats

Objectives

This study aimed to investigate metabolic biomarker changes and related metabolic pathways before and after treatment with l-borneolum in cerebral ischaemic rats.

Methods

Rats were subjected to pMCAO surgery. The Zea-Longa scoring method was used to evaluate neurological deficits. TTC staining was used to observe cerebral infarction. HE staining was used to observe the pathological changes in brain tissue. The metabolomics method was used to analyse the changes in metabolism.

Results

The pharmacology changes of the H-B group were significantly different from those of the vehicle group. Moreover, according to the metabolomics method, identification of potential biomarkers in cerebral ischaemia treatment showed that the levels of l-valine and l-arginine were increased while the levels of N-succinyl-L,L-2,6-diaminopimelate and LysoPC (18 : 1(9Z)) were reduced, which were related to energy metabolism. Simultaneously, thermogenesis and bile secretion levels were inhibited by l-borneolum. Furthermore, elevated level of methotrexate might be related to an anti-inflammatory effect.

Conclusions

The therapeutic effect of l-borneolum on cerebral ischaemia might be associated with the regulation of energy metabolism, thermogenesis and bile secretion. These metabolic changes and the core target changes, as well as the metabolic-target pathway network, help to elucidate the mechanisms governing the effect of l-borneolum on cerebral ischaemia.