Collagen-induced Rheumatoid Arthritis Rats Research Articles

Effect of electroacupuncture at ST36 on the cerebral metabolic kinetics of rheumatoid arthritis rats

Electroacupuncture (EA) has been shown to enhance the recovery of symptoms in rheumatoid arthritis (RA); however, the underlying mechanism remains unclear. Both the pathogenesis of RA and the therapeutic effects of EA are closely associated with the metabolic activity of the brain. In this study, we investigated the effect of EA at the “Zusanli” acupoint (ST36) on a rat model of collagen-induced rheumatoid arthritis (CIA). The results demonstrated that EA effectively alleviated joint swelling, synovial hyperplasia, cartilage erosion, and bone destruction in CIA rats. Additionally, the metabolic kinetics study revealed a significant increase in the 13C enrichment of GABA2 and Glu4 in the midbrain of CIA rats treated with EA. Correlation network analysis showed that changes in Gln4 levels in the hippocampus were strongly associated with the severity of rheumatoid arthritis. Immunofluorescence staining of c-Fos in the midbrain’s periaqueductal gray matter (PAG) and hippocampus demonstrated increased c-Fos expression in these regions following EA treatment. These findings suggest that GABAergic and glutamatergic neurons in the midbrain, along with astrocytes in the hippocampus, may play vital roles in the beneficial effects of EA on RA. Furthermore, the PAG and hippocampus brain regions hold potential as critical targets for future RA treatments. Overall, this study provides valuable insights into the specific mechanism of EA in treating RA by elucidating the perspective of cerebral metabolism.

Non-alcoholic fatty liver disease combined with rheumatoid arthritis exacerbates liver fibrosis by stimulating co-localization of PTRF and TLR4 in rats.

Rheumatoid arthritis (RA) has a high prevalence in patients with non-alcoholic fatty liver disease (NAFLD); however, the underlying mechanism is unclear. To address this, our study established a rat model with both NAFLD and RA by feeding a high-fat diet (HFD) and administering intradermal injection of Freund's complete adjuvant (FCA) with bovine type II collagen. Collagen-induced RA (CIA) was confirmed by hind paw swelling and histological examination. The histomorphological characteristics of NAFLD were evaluated by Masson's trichrome and hematoxylin-eosin staining. The development of NAFLD was further evaluated by measuring serum concentrations of triglyceride (TG), total cholesterol (T-CHO), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lipopolysaccharide (LPS). The results showed that HFD feeding exacerbated secondary inflammation in CIA rats, whereas FCA/bovine type II collagen injection increased serum levels of ALT, AST, TG, T-CHO, and LPS and exacerbated hepatic fibrosis in both normal and NAFLD rats. Interestingly, NAFLD + CIA significantly promoted the expression of PTRF, a caveolae structure protein involved in hepatic lipid metabolism and affecting downstream signaling of Toll-like receptor 4 (TLR4) and PI3K/Akt activation. High resolution confocal microscopy revealed increased PTRF and TLR4 co-localization in hepatic small vessels of NAFLD + CIA rats. AAV9-mediated PTRF knockdown inhibited TLR4 signaling and alleviated hepatic fibrosis in NAFLD + CIA rats. Together, these findings indicate that NAFLD combined with CIA causes synovial injury and enhances non-alcoholic fatty liver fibrosis in rats. PTRF could attenuate the symptoms of NAFLD + CIA likely by affecting TLR4/PTRF co-expression and downstream signaling.

Simultaneous Immunomodulation and Tissue Protection on the Rheumatoid Arthritis Models Using a Tragacanth Frankincense-Based Core–Shell Nanostructure

Rheumatoid arthritis (RA) is a chronic autoimmune disease that requires anti-inflammatory drugs, analgesics, and tissue protectors. To deal with this disease, the pain and inflammation should be relieved in the first stage, and tissue protectors should be used to restore joint damage that limits movement. Therefore, a comprehensive multifunctional core–shell nanocomposite (TFH@TA/AuNPs-HDA) with a continuous anti-inflammatory effect and a special tissue protection potential in the core was designed. Here, the hydrothermal reaction was applied to synthesize the hydrogel core from tragacanth and frankincense gums; then, the shell was self-assembled with tannic acid/gold nanoparticles (TA/AuNPs) and 10-hydroxy-2-decanoic acid (10-HDA). The biocompatibility, anti-inflammatory properties, and tissue protective effect of TFH@TA/AuNPs-HDA were investigated on RAW264.7 cells and in collagen-induced RA rat models. Moreover, the molecular docking demonstrated the interactions of 10-HDA and AuNPs with NF-κB signaling pathway proteins, confirming the anti-inflammatory effect of 10-HDA and AuNP suppression of the NF-κB pathway. The results revealed that TFH@TA/AuNPs-HDA could be an appropriate system for RA therapy due to the synergistic alleviation of inflammation and joint tissue destruction.

Metabonomics and 16S rRNA gene sequencing to study the therapeutic mechanism of Danggui Sini decoction on collagen-induced rheumatoid arthritis rats with Cold Bi syndrome

Rheumatoid arthritis (RA) is an autoimmune disease characterized by persistent joint inflammation. The development of rheumatoid arthritis is directly correlated with the disturbance of gut microbiome and its metabolites. RA can be effectively treated with the Danggui Sini decoction (DSD), a Traditional Chinese medicine (TCM) prescription from the Treatise on Febrile Diseases. Further research is needed to clarify the precise mechanism of DSD in the treatment of RA. In this study, 1H NMR metabonomics and 16 S rRNA gene sequencing techniques were used to clarify the intervention of DSD on CIA-induced RA. The results of 1H NMR metabolomics of feces revealed that five metabolites (alanine, glucose, taurine, betaine, and xylose) were disturbed, which could be regarded as potential biomarkers of RA. The intestinal microbiome of RA rats had changed, according to the results of 16 S rRNA gene sequencing; eight microbes (g_norank_f_Eubacterium_coprostanoligenes_group, g_Ruminococcus_torques_group, g_Dubosiell, g_Lactobacillus, g_norank_f_Desulfovibrionaceae, g_Bacteroides, g_Oscillibacter, and g_Romboutsia) occurred significantly at the genus level, and DSD significantly impacted six of them (g_Dubosiell, g_Lactobacillus, g_norank_f_Eubacterium_coprostanoligenes_group, g_Ruminococcus_torques_grou, g_Bacteroides, and g_Romboutsia). Three of them (g_norank_f_Eubacterium_ coprostanoligenes_group, g_Romboutsia, and g_Lactobacillus) were regarded as key microbiomes for DSD to treat RA, and three common metabolic pathways (taurine and hypotaurine metabolism; alanine, aspartate, and glutamate metabolism; primary bile acid biosynthesis) were discovered based on the 1H NMR metabonomics and PICRUST2 prediction of 16 S rRNA gene sequencing. Six SCFAs in feces (acetic acid, butyric acid, propionic acid, caproic acid, isobutyric acid, and valeric acid) increased significantly in RA, according to the outcomes of targeting SCFAs, while five SCFAs (acetic acid, butyric acid, propionic acid, caproic acid, and valeric acid) had decreased significantly due to DSD treatment. In conclusion, our study indicated that DSD could regulate RA’s metabolic disorder by affecting intestinal microbiome and its metabolites. It also establishes a framework for future research into exploiting gut microbes therapeutic to treat RA.

Daphnes Cortex and its licorice-processed products suppress inflammation via the TLR4/NF-κB/NLRP3 signaling pathway and regulation of the metabolic profile in the treatment of rheumatoid arthritis

Ethnopharmacological relevanceDaphnes Cortex (Daphne Giraldii Nitsche, DGN) is a popular traditional Chinese herbal medicine for traumatic injuries and rheumatoid arthritis (RA) in the Shaanxi and Gansu provinces of China. Due to skin irritation caused by raw DGN (RDGN), licorice-processed DGN products are usually used in clinical practice. However, the efficacy and mechanisms of action between DGN and its licorice-processed DGN products in treating RA have not been compared. AimsThis study compared the efficacy and elucidated the mechanisms in vitro and in vivo between RDGN and its licorice-processed DGN products in treating RA. Materials and methodsA collagen-induced RA rat model was established, and treated with different doses of RDGN and its licorice-processed DGN products for 4 weeks to explore the therapeutic effects. The anti-inflammatory effects were assessed in RAW 264.7 macrophages stimulated by lipopolysaccharide (LPS). Analyses of the differential quality markers (DQMs) between DGN and its licorice-processed DGN products using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry, and non-targeted metabolomics analyses of rat synovial tissues were used to systematically explore correlations between DGN processing and its efficacy. ResultsLicorice-processed DGN products significantly ameliorated RA symptoms in CIA rats. Licorice-processed DGN products also regulated inflammatory cytokines, matrix metalloproteinases, and vascular endothelial growth factor in the serum and cell supernatants. Licorice-processed DGN products significantly inhibited Toll-like receptor 4/nuclear factor kappa B/NOD-like receptor family, pyrin domain containing 3 (TLR4/NF-κB/NLRP3) signaling in CIA rats and LPS-induced RAW264.7 cells. The DQMs between RDGN and its licorice-processed DGN products were identified, most of which were amino acids or energy-related metabolites present in licorice-processed DGN products. Correlations between DQMs with differential metabolites and differential metabolic pathways were established. ConclusionsLicorice-processed DGN products displayed better anti-inflammatory effects via the TLR4/NF-κB/NLRP3 signaling pathway on CIA rats and LPS-induced RAW264.7 cells, and regulation of the metabolic profile in treating RA.

Tumor necrosis factor receptor-associated factor 6 (TRAF6) inhibition modulates bone loss and matrix metalloproteinase expression levels in collagen-induced rheumatoid arthritis rat.

Rheumatoid arthritis (RA) is a main characterized by persistent synovitis, systemic inflammation, and autoantibodies. Tumor necrosis factor receptor-associated factor 6 (TRAF6) is an E3 ubiquitin ligase and is a crucial cytoplasm signal adaptor that can regulate critical biological processes. This research aims to explore the function of TRAF6 on bone loss and matrix metalloproteinase (MMP) expression in collagen-induced RA rats. The RA model in rats (Sprague Dawley rat, 5-6 weeks old, weight 246.88±8.31 g) was set up via using collagen-induced RA. The shRNA-TRAF6 knockdown efficiency was tested using real-time reverse transcription-polymerase chain reaction (qRT-PCR) and western blot, respectively. The rats were divided into four groups: the control group, RA group, RA + shRNA-NC group, and RA + TRAF6-shRNA group. The tartrate-resistant acidic phosphatase (TRAP), hematoxylin and eosin (H&E), and Saffron O staining were employed to test the bone injury. The mRNA and protein expressive of Osteoclast-associated receptor (OSCAR), TRAP, Osterix (Osx), Collagen type I alpha 1 (COL1A1), Distal-less homeobox2 (Dlx2), tissue inhibitor of metalloproteinase (TIMP), matrix metalloproteinase-1(MMP-1), Cyclooxygenase 2 (COX2) and qRT-PCR performed MMP-13 and western blot, respectively. The mRNA and protein expression levels of TRAF6 were down-regulated in the RA + TRAF6- shRNA group. After the levels of TRAF6 were inhibited, the levels of bone volume/total volume (BV/TV), trabecular bone thickness (Tb.Th), and trabecular bone number (Tb.N) were increased, while the levels of trabecular bone space (Tb.Sp), Osteocalcin and ALP were deceased. The mRNA and protein expression levels of OSCAR, TRAP, MMP-1, COX2, and MMP-13 were reduced obviously in the RA + TRAF6- shRNA group compared with the RA + shRNA-NC group, while the levels of TIMP-1, OSX, CoL1A1, and DLx2 were enhanced obviously. Inhibition of TRAF6 reduces bone loss and MMP expression levels in collagen-induced RA rat, and supplies an alternative treatment method in RA.

Paeoniflorin inhibits Rho kinase activation in joint synovial tissues of rats with collagen-induced rheumatoid arthritis

Paeoniflorin (PF) has many effects, such as anti-inflammation, immune-regulation, abirritation, and so on. However, the protective mechanisms of PF on rheumatoid arthritis (RA) was not completely known. Thus, we explored deeply the protective mechanisms in a collagen-induced RA (CIA) rat model. CIA was induced in rats by intradermal injection of bovine type II collagen in complete Freund's adjuvant. Later, the CIA rats received oral administration of PF (50 and 100 mg/kg) once a day from the day 21, with the treatment lasting for 14 days. A variety of indicators were measured for evaluation of anti-rheumatism effect, including paw swelling, arthritis scores, and histopathological changes. And the contents of pro-inflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6) in the serum, as well as p-NF-κB p65 and p-MYPT1 in the joint synovial tissues were detected to explore the possible mechanisms. The results demonstrated that PF treatment significantly ameliorated the symptoms in CIA rats, reduced the levels of pro-inflammatory cytokines and paw swelling, down-regulated the expressions of p-NF-κB p65 and p-MYPT1. The present results revealed that PF could effectively improve collagen-induced RA in rats by inhibiting Rho kinase activation in the joint synovial tissues, in turn down-regulating expression of p-NF-κB p65 and reducing contents of pro-inflammatory cytokines. Moreover, PF may be an effective agent for RA.

Salvianolic Acid B Suppresses Inflammatory Mediator Levels by Downregulating NF-κB in a Rat Model of Rheumatoid Arthritis.

BackgroundSalvianolic acid B (SB) is a major active phyto-component of the plant Radix Salvia miltiorrhiza, which is traditionally used to treat joint pain and arthritis. The present study examined the anti-rheumatoid arthritis efficacy of SB on collagen-induced rheumatoid arthritis (CIA) in a rat model.Material/MethodsForty-eight rats were divided into 4 groups: Control rats treated with saline (Group I), rats subjected to CIA induction by intradermal injection of bovine collagen II type at the tail (Group II), and rats subjected to CIA and supplemented with either 20 or 40 mg/kg of SB for 28 days (group III or IV).ResultsPaw swelling, edema, arthritis score, thymus and spleen indexes, and neutrophil infiltration were significantly decreased (p<0.01) by treatment with 20 or 40 mg/kg of SB. The levels of inflammatory cytokines (interleukin-1β, -6, and -17, and TNF-α) and anti-collagen II-specific immunoglobulins (IgG1 and IgG2a) were markedly decreased (p<0.01), and those of antioxidant enzymes (SOD, CAT, and GSH) were significantly increased (p<0.01) in SB-treated rats. Administration with SB (20 or 40 mg/kg) resulted in lower phosphorylated IκB-α and NF-κB p65 protein levels and markedly downregulated IκB-α expression. Furthermore, CIA rats revealed the presence of highly diffused polymorphonuclear cells (PMNs) infiltration with eroded cartilage; however, these phenomena were considerably ameliorated by SB.ConclusionsSB alleviates oxidative stress and inflammation in CIA rats, thus verifying its anti-rheumatoid arthritis property.

Petroleum ether extractive of the hips of Rosa multiflora ameliorates collagen-induced arthritis in rats

Ethnopharmacological relevanceThe hip of Rosa multiflora Thunb. (HRM) has been traditionally used as a dietary supplement and a herbal remedy for the treatment of various diseases, including inflammation, osteoarthritis, rheumatoid arthritis and chronic pain, in China. The current study was to evaluate the therapeutic efficacy of the petroleum ether extractive of HRM (PEE) on type II collagen-induced rheumatoid arthritis (CIA) in male Wistar rats. In addition, the anti-inflammatory mechanism(s) of PEE on type II CIA was explored. Materials and methodsRheumatoid arthritis (RA) was induced by intradermal injection of bovine type II collagen on Day 1 and Day 8. Starting from Day 13, normal rats were treated with vehicle (serving as the control group); the CIA rats were treated with vehicle (CIA group), dexamethasone (0.25mg/kg bw per day, p.o.) (a positive control), lei-gong-teng (LGT: 10mg/kg bw per day, p.o.) (a clinically used Chinese patent medicine in RA therapy) or PEE (12, 36 or 120mg/kg bw per day, p.o.) for 28 days. Results and conclusionsPEE (120mg/kg bw per day) efficiently attenuated the severity of arthritis in the CIA rats by reducing the mean arthritis severity scores and the fore/hind paw swelling as well as reduced histological changes by decreasing the cartilage surface erosion and cartilage proteoglan depletion. PEE׳s therapeutic effect in RA may involve the inhibition of pro-inflammatory cytokines, such as TNF-α, IL-1β and IL-6, in serum and/or the elevation of the activities of hepatic anti-oxidative enzymes including SOD, CAT and GSH-Px. However, the detailed anti-inflammatory mechanism, the main effective components and the interaction between different ingredients in PEE are still not clear and require more studies.

関節リウマチに対するレーザー照射療法の機能ゲノム科学的考察

Rheumatoid arthritis (RA) is a systemic autoimmune disorder that involves inflammation and pain of joints and has been treated by steroid hormones. However, long-term use of steroid often causes side effects. Low-level laser irradiation (LLLI) is being evaluated for treating RA, and no side effects have been reported. LLLI reduced inflammation in collagen-induced RA rats. Linearly polarized infrared light irradiation (IPIL) and steroid reduced the expression of IL-8 in human RA synoviocyte MH-7A cells. GeneChip analysis coupled with a signal pathway database showed that steroid randomly altered the expression of many genes including unwanted genes, whereas IPIL reduced genes which are useful for anti-inflammation.

REDUCTION OF INTERLEUKIN-1.BETA. EXPRESSION IN RHEUMATOID ARTHRITIS BY LINEAR POLARIZED NEAR INFRARED LIGHT IRRADIATION

Background: Rheumatoid arthritis (RA) is a systemic autoimmune disorder that involves inflammation and pain of joints. Low-level light therapy (LLLT) is being evaluated for treating RA. However, the molecular basis mechanism underlying the effectiveness of linear polarized near infrared light irradiation (LPIL) is unclear. It has been reported that interleukin 1β (IL-1β) plays a key role in the progression of RA.Aim: The objective of this study was to determine whether LPIL (Super Lizer™; SL) decrease gene expression and production IL-1β in human RA synovial cells, MH7A, and RA joint tissue of collagen-induced-rheumatoid arthritis (CIA) rats.Materials and Methods: IL-1β challenged MH7A and CIA rat joints were irradiated with SL. Total RNA was isolated from MH7A, and gene expression profiles were analyzed using DNA microarray.The mRNA levels were confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR. The production of IL-1β in rat knee joints was analyzed by immunohistochemistry.Results: DNA microarray analysis showed that IL-1β increased IL-1β gene expression in MH7A, and SL significantly reduced its IL-1β mRNA level. The reduction of IL-1β mRNA level by SL was successfully confirmed by reverse RT-PCR and real-time PCR. SL reduced the swelling of CIA rat knee joints, and the immunohistochemical study demonstrated that a strong IL-1β staining in synovial membrane tissue of CIA rat joint, and the immuno-staining was significantly reduced by SL.Conclusion: Since autocrine IL-1β production has been identified to be an important proinflammatory cytokine in the pathogenesis of RA, the reduction of IL-1β expression in RA synovial cells is one of mechanisms in reduction of the inflammation in RA by SL.

Effect of Low-Level Laser Irradiation on CXCL13 Gene Expression in Rheumatoid Arthritis Rat Joints

Rheumatoid arthritis (RA) is an inflammatory joint disorder, the progression of which leads to the destruction of cartilage and bone. Low-level laser irradiation (LLLI) is currently being evaluated for the treatment of RA, but the molecular mechanism underlying the effectiveness of LLLI in RA is unclear. B-cell-attracting chemokine-1 (CXCL13) is classified as a lymphoid chemokine and is a potent B-cell chemoattractant, leading to the local production of the autoantibody. The objective of this study was to determine whether LLLI decreased CXCL13 gene expression in joints of collagen-induced RA (CIA) rats. CIA caused swelling of rat joints, and LLLI significantly decreased the swelling. Total RNA was isolated from synovial membrane tissue of CIA rat joints with or without treatment from an 830 nm Ga-Al-As diode LLLI, and gene expression profiles were analyzed by DNA microarray (rat 41,000 genes). DNA microarray analysis showed that CXCL13 gene expression was increased in CIA tissue, and that LLLI significantly decreased the CIA-induced CXCL13 mRNA level. The reduction in CXCL13 gene expression was confirmed by reverse transcription polymerase chain reaction (RT-PCR) and real-time PCR. The findings suggest that decreased CXCL13 gene expression may be one of mechanisms involved in the reduction of inflammation in RA by LLLI.