Chemokine Receptor 5 Antagonism Causes Reduction in Joint Inflammation in a Collagen-Induced Arthritis Mouse Model

Models in vivo and in vitro for the study of acute and chronic inflammatory activity: A comprehensive review

Inflammatory conditions are among the principal causes of morbidity worldwide, and their treatment continues to be a challenge, given the restricted availability of effective and safe drugs. Thus, the identification of new compounds with biological activity that can be used for the treatment of inflammatory disorders is an essential field in medical and health research, in order to improve the health and quality of life of patients suffering from these diseases. Evaluation of the anti-inflammatory activity of drugs requires the implementation of models that accurately depict the biochemical and/or physiological responses that characterize human inflammation; for this reason, several in vitro and in vivo models have been developed, providing a platform for discovering novel or repurposed compounds. For this reason, in the present review we have selected twelve commonly used models for the evaluation of the anti-inflammatory effect, and extensively describes the difference between in vivo and in vitro models of inflammation, highlighting their advantages and limitations. On the other hand, the inflammatory mechanisms involved in them, the methods employed for their establishment, and the different parameters assessed to determine the anti-inflammatory activity of a given compound are extensively discussed. We expect to provide a comprehensive guide for the improved selection of a suitable model for the preclinical evaluation of plausible anti-inflammatory agents.

CCR5 regulates Aβ1-42-induced learning and memory deficits in mice

C-C chemokine receptor 5 (CCR5) is a chemokine receptor involved in immune responses and a co-receptor for HIV infection. Recently, CCR5 has also been reported to play a role in synaptic plasticity, learning and memory, and cognitive deficits associated with normal aging, traumatic brain injury (TBI), and HIV-associated neurocognitive disorder (HAND). In contrast, the role of CCR5 in cognitive deficits associated with other disorders, including Alzheimer's disease (AD), is much less understood. Studies have reported an increase in expression of CCR5 or its ligands in both AD patients and AD rodent models, suggesting a correlation between AD and CCR5 expression. However, whether blocking CCR5 in specific brain regions, such as the hippocampus, could improve memory deficits in AD mouse models is unknown. To study the potential causal role of CCR5 in cognitive deficits in AD, we injected soluble Aβ1-42 or a control (Aβ42-1) oligomers in the dorsal CA1 region of the hippocampus and found that Aβ1-42 injection resulted in severe memory impairment in the object place recognition (OPR) and novel object recognition (NOR) tests. Aβ1-42 injection caused an increase in Ccr5, Ccl3, and Ccl4 in the dorsal hippocampus, and the expression levels of CCR5 and its ligands remained elevated at 2 weeks after Aβ1-42 injection. Knocking down Ccr5 in the CA1 region of dorsal hippocampus reversed the increase in microglia number and size in dorsal CA1 and rescued memory deficits. These results indicate that CCR5 plays an important role in modulating Aβ1-42-induced learning and memory deficits, and suggest that CCR5 antagonists may serve as a potential treatment to improve cognitive deficits associated with AD.

Forsythoside B alleviates osteoarthritis through the HMGB1/TLR4/NF-κB and Keap1/Nrf2/HO-1 pathways

Osteoarthritis (OA) is a joint pain and dysfunction syndrome resulting from severe joint degeneration. Inflammation and degeneration of the articular cartilage are two main features of OA and have tight interactions during OA progression. Conventional treatment with nonsteroidal anti-inflammatory drugs has been widely utilized clinically, whereas the side effects have restricted their application. Forsythoside B has been found with anti-inflammatory effects and antiapoptosis in inflammatory diseases, whereas in OA it remains poorly understood. Interleukin (IL)-1β (10 ng/mL) was taken to induce an OA cell model on HC-A chondrocytes and an OA rat model was constructed for in vivo experiments. Forsythoside B was adopted to treat HC-A chondrocytes and OA rats. As shown by the data, Forsythoside B hampered IL-1β-elicited rat chondrocyte apoptosis, oxidative stress, and facilitated proliferation. The profiles of inflammatory factors, NOD-like receptor family pyrin domain containing 3 inflammasomes, Kelch-like epichlorohydrin-associated protein-1 (Keap1), and nuclear factor-κB (NF-κB) phosphorylation were suppressed by Forsythoside B, whereas the nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) levels were promoted. Further, Forsythoside B mitigated cartilage damage and degeneration. Moreover, the oxidative stress and inflammation mediators in the cartilage tissue of OA rats were remarkably abated. Collectively, Forsythoside B hinders the NF-κB and Keap1/Nrf2/HO-1 pathways to curb IL-1β-elicited OA rat oxidative stress and inflammation both in vivo and ex vivo, ameliorating OA development. All over, this study provides an underlying strategy for treating OA, which might help the clinical treatment of OA patients.

TAGAP activates Th17 cell differentiation by promoting RhoA and NLRP3 to accelerate rheumatoid arthritis development

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that can give rise to joint swelling and inflammation, potentially affecting the entire body, closely linked to the state of T cells. The T-cell activation Rho GTPase activating protein (TAGAP) is associated with many autoimmune diseases including RA and is directly linked to the differentiation of Th17 cells. The present study intends to investigate the influence of TAGAP on the RA progression and its mechanism to empower new treatments for RA. A collagen-induced-arthritis (CIA) rat model was constructed, as well as the extraction of CD4+ T cells. RT-qPCR, H&E staining and safranin O/fast green staining revealed that TAGAP interference reduced TAGAP production in the ankle joint of CIA rats, and joint inflammation and swelling were alleviated, which reveals that TAGAP interference reduces synovial inflammation and cartilage erosion in the rat ankle joint. Expression of inflammatory factors (TNF-α, IL-1β, and IL-17) revealed that TAGAP interference suppressed the inflammatory response. Expression of pro-inflammatory cytokines, matrix-degrading enzymes, and anti-inflammatory cytokines at the mRNA level was detected by RT-qPCR and revealed that TAGAP interference contributed to the remission of RA. Mechanistically, TAGAP interference caused a significant decrease in the levels of RhoA and NLRP3. Assessment of Th17/Treg levels by flow cytometry revealed that TAGAP promotes Th17 cells differentiation and inhibits Treg cells differentiation in vitro and in vivo. In conclusion, TAGAP interference may decrease the differentiation of Th17 cells by suppressing the expression of RhoA and NLRP3 to slow down the RA progression.

Rituximab alleviates increased disomic sperm in DBA/1J mouse models of rheumatoid arthritis via restoration of redox imbalance

Compared to the general population, patients with arthritis have a higher risk of fertility abnormalities, which have deleterious effects on both reproductive function and pregnancy outcomes, especially in patients wishing to conceive. These may be due to the disease itself or those of drug therapies. Despite the increasing use of rituximab in arthritis, limited data are available on its potential to induce aneuploidy in germ cells. Therefore, the aim of the current investigation was to determine if repeated treatment with rituximab affects the incidence of aneuploidy and redox imbalance in arthritic mouse sperm. Mice were treated with 250 mg/kg rituximab once weakly for 3 weeks, and then sperm were sampled 22 days after the last dose of rituximab. Fluorescence in situ hybridization assay with chromosome-specific DNA probes was used to evaluate the disomic/diploid sperm. Our results showed that rituximab had no aneuploidogenic effect on the meiotic stage of spermatogenesis. Conversely, arthritis induced a significantly high frequency of disomy, and treatment of arthritic mice with rituximab reduced the increased levels of disomic sperm. The occurrence of total diploidy was not significantly different in all groups. Reduced glutathione and8-hydroxydeoxyguanosine, markers of oxidative stress were significantly altered in arthritic animals, while rituximab treatment restored these changes. Additionally, arthritis severity was reduced after rituximab treatment. We conclude that rituximab may efficiently alleviate the arthritis-induced effects on male meiosis and avert the higher risk of abnormal reproductive outcomes. Therefore, treating arthritic patients with rituximab may efficiently inhibit the transmission of genetic anomalies induced by arthritis to future generations.

Association Between Serum Chemokine Ligand 20 Levels and Disease Activity and Th1/Th2/Th17-Related Cytokine Levels in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a type of arthritis autoimmune disease characterized by systemic chronic inflammation. C-C Chemokine ligand 20 (CCL20) is the same as most chemokines with immunomodulatory and inflammatory processes. The correlation of CCL20 in RA remains unclear. This study aimed to explore the association among levels of CCL20, T helper cell (TH) subset (Th1/Th2/Th17)-related cytokine levels, and clinical indices of RA disease activity. Serum CCL20 levels were quantified by enzyme-linked immunosorbent assay, and a flow-fluorescence technique was used to assess Th1/Th2/Th17-related cytokine levels. The serum CCL20 levels in patients were significantly higher than those in healthy controls and positively associated with C-reactive protein levels, erythrocyte sedimentation rate, and disease activity score-28 (DAS28). Patients with RA were categorized into 4 major groups, including remission, low, moderate, and high disease activity, with related DAS28 scores for each group. CCL20 levels of the disease moderate/high activity group were moderately positively correlated with IL-6 levels, but not with the other Th1/Th2/Th17-related cytokines. Serum CCL20 levels correlate strongly with RA disease activity and clinical inflammation and were significantly elevated in patients compared to healthy individuals. CCL20 plays a key role in the immune response of patients with RA and is, therefore, a potential biomarker of disease activity.

Bioinformatics identification of ferroptosis-related genes and therapeutic drugs in rheumatoid arthritis

Introduction

Rheumatoid arthritis (RA) is a chronic immune disease characterized by synovial inflammation and bone destruction, with a largely unclear etiology. Evidence has indicated that ferroptosis may play an increasingly important role in the onset and development of RA. However, ferroptosis-related genes are still largely unexplored in RA. Therefore, this work focused on identifying and validating the potential ferroptosis-related genes involved in RA through bioinformatics analysis.

Methods

We screened differentially expressed ferroptosis-related genes (DEFGs) between RA patients and healthy individuals based on GSE55235 dataset. Subsequently, correlation analysis, protein-protein interaction (PPI) network analysis, GO, and KEGG enrichment analyses were performed using these DEFGs. Finally, our results were validated by GSE12021 dataset.

Results

We discovered 34 potential DEFGs in RA based on bioinformatics analysis. According to functional enrichment analysis, these genes were mainly enriched in HIF-1 signaling pathway, FoxO signaling pathway, and Ferroptosis pathway. Four genes (GABARPL1, DUSP1, JUN, and MAPK8) were validated to be downregulated by GSE12021 dataset and were diagnostic biomarkers and therapeutic targets for RA via the regulation of ferroptosis.

Discussion

Our results help shed more light on the pathogenesis of RA. Ferroptosis-related genes in RA are valuable diagnostic biomarkers and they will be exploited clinically as therapeutic targets in the future.

Magnoflorine Ameliorates Collagen-Induced Arthritis by Suppressing the Inflammation Response via the NF-κB/MAPK Signaling Pathways

Objective

Magnoflorine (Mag) has been reported to have anxiolytics, anti-cancer, and anti-inflammatory properties. In this study, we aim to investigate the effects of Mag on the rheumatoid arthritis (RA) and explore the underlying mechanism using a collagen-induced arthritis (CIA) mouse model and a lipopolysaccharide (LPS)-stimulated macrophage inflammation model.

Methods

The in vivo effects of Mag on CIA were studied by inducing CIA in a mouse model using DBA/1J mice followed by treatment with vehicle, methotrexate (MTX, 1 mg/kg/d), and Mag (5 mg/kg/d, 10 mg/kg/d, and 20 mg/kg/d), and the in vitro effects of Mag on macrophages were examined by stimulation of RAW264.7 cells line and peritoneal macrophages (PMs) by LPS in the presence of different concentrations of Mag. Network pharmacology and molecular docking was then performed to predict the the binding ability between Mag and its targets. Inflammatory mediators were assayed by quantitative real-time PCR and enzyme linked immunosorbent assay (ELISA). Signaling pathway changes were subsequently determined by Western blotting and immunohistochemistry (IHC).

Results

In vivo experiments demonstrated that Mag decreased arthritis severity scores, joints destruction, and macrophages infiltration into the synovial tissues of the CIA mice. Network pharmacology analysis revealed that Mag interacted with TNF-α, IL-6, IL-1β, and MCP-1. Consistent with this, analysis of the serum, synovial tissue of the CIA mice, and the supernatant of the cultured RAW264.7 cells and PMs showed that Mag suppressed the expression of TNF-α, IL-6, IL-1β, MCP-1, iNOS, and IFN-β. Furthermore, Mag attenuated the phosphorylation of p65, IκBα, ERK, JNK, and p38 MAPKs in the synovial tissues of the CIA mice and LPS-stimulated RAW 264.7 cells.

Conclusion

Mag may exert anti-arthritic and anti-inflammatory effects by inhibiting the activation of NF-κB and MAPK signaling pathways.

CXCR3 antagonist NBI-74330 mitigates joint inflammation in Collagen-Induced arthritis model in DBA/1J mice

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by uncontrolled synovial proliferation, pannus formation, cartilage injury, and bone destruction. We used the CXCR3-specific antagonist NBI-74330 to block T-cell-mediated signaling in a DBA/1J mouse model of collagen-induced arthritis (CIA). After CIA induction, DBA/1J mice were treated with NBI-74330 (100 mg/kg) daily from day 21 until day 34 and evaluated for arthritic score and histopathological changes. Furthermore, using flow cytometry, we investigated the effects of NBI-74330 on Th1 (IFN-γ, TNF-α, T-bet, STAT4, Notch-3, and RANKL), Th17 (IL-21, IL-17A, STAT3, and RORγt), and Th22 (IL-22) cells in splenic CD4⁺ and CXCR3⁺T-cells. We also used RT-PCR to assess the effect of mRNA levels of IFN-γ, TNF-α, T-bet, RANKL, IL-17A, RORγt, and IL-22 in knee tissues. The IFN-γ, TNF-α, and IL-17A serum protein levels were measured using ELISA. Compared to vehicle-treated CIA mice, the severity of arthritic scores and histological severity of inflammation decreased significantly in NBI-74330-treated CIA mice. Moreover, compared to vehicle-treated CIA mice, the percentages of CD4⁺IFN-γ⁺, CD4⁺TNF-α⁺, CD4⁺T-bet⁺, CD4⁺STAT4⁺, CD4⁺Notch-3⁺, CXCR3⁺IFN-γ⁺, CXCR3⁺TNF-α⁺, CXCR3⁺T-bet⁺, CXCR3⁺STAT4⁺, CXCR3⁺Notch-3⁺, CD4⁺RANKL⁺, CD4⁺IL-21⁺, CD4⁺IL-17A⁺, CD4⁺STAT3⁺, CD4⁺RORγt⁺, and CD4⁺IL-22⁺ cells decreased in NBI-74330-treated CIA mice. Furthermore, NBI-74330-treatment downregulated IFN-γ, TNF-α, T-bet, RANKL, STAT3, IL-17A, RORγt, and IL-22 mRNA levels. Serum IFN-γ, TNF-α, and IL-17A levels were significantly lower in NBI-74330-treated CIA mice than in vehicle-treated CIA mice. This study demonstrates the antiarthritic effects of NBI-74330 in CIA mice. Therefore, these data suggest that NBI-74330 could be considered a potential RA treatment.

Mechanism underlying the action of Duanteng-Yimu Tang in regulating Treg/Th17 imbalance and anti-rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is a chronic immune disease characterised by synovitis and cartilage destruction. Currently, many patients experience poor remission after new antirheumatic drug treatments. Duanteng-Yimu Tang (DTYMT), a traditional Chinese medicine, is effective in the treatment of RA. In this research, we designed to investigate the anti-RA effects of DTYMT and explore its potential mechanisms.

Methods

Network pharmacology was adopted to explore the main pathways of DTYMT in patients with RA. Collagen-induced arthritis models of male DBA/1 mice were established, and their histopathological changes were observed by hematoxylin-eosin staining and micro-CT. qRT-PCR was performed to detect the expression of Foxp3 and RORγt in the serum and synovial tissue and IL-17, IL-1β, TNF-α, and IL-10 mRNA in vivo. The proliferation and invasion of synovial cells were analyzed using Cell Counting Kit-8 and transwell assays, respectively. The ratio of T helper 17 (Th17) to regulatory T (Treg) cells was analyzed by flow cytometry.

Results

Network pharmacology analysis revealed that Th17 cell differentiation may be the key pathway of DTYMT in RA. DTYMT ameliorated joint damage, inhibited RORγt expression, and increased Foxp3 expression in CIA mice. DTYMT significantly decreased IL-1β, IL-17, and TNF-α mRNA levels, and increased IL-10 mRNA levels in IL-6-induced cells. Additionally, DTYMT inhibited Th17 cell differentiation and promoted Treg cell production, thus improving the Treg/Th17 imbalance. DTYMT also inhibited the proliferation, migration, and invasion of RA fibroblast-like synovial cells.

Conclusions

These results indicate that DTYMT could regulate the Treg/Th17 cell balance, which is a possible mechanism of DTYMT in treating RA.

Aneugenic and clastogenic alterations in the DBA/IJ mouse model of rheumatoid arthritis treated with rituximab, an anti-CD20 antibody

Rheumatoid arthritis (RA), an autoimmune disorder in which the immune system attacks healthy cells, is associated with elevated risk of lymphoma. Rituximab, a treatment for non-Hodgkin's lymphoma, has been approved as a treatment for RA. We studied the effects of rituximab on chromosomal stability in collagen-induced arthritis DBA/1J animal models. Micronucleus levels were increased in the mouse models, mainly due to chromosome loss, as detected by fluorescence in situ hybridization; rituximab-treated arthritic mice had significantly less micronucleus formation. Serum 8-hydroxydeoxyguanosine, a DNA oxidative stress marker, was increased in the mice models but reduced following rituximab administration.

Chemokines and chemokine receptors as promising targets in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that commonly causes inflammation and bone destruction in multiple joints. Inflammatory cytokines, such as IL-6 and TNF-α, play important roles in RA development and pathogenesis. Biological therapies targeting these cytokines have revolutionized RA therapy. However, approximately 50% of the patients are non-responders to these therapies. Therefore, there is an ongoing need to identify new therapeutic targets and therapies for patients with RA. In this review, we focus on the pathogenic roles of chemokines and their G-protein-coupled receptors (GPCRs) in RA. Inflamed tissues in RA, such as the synovium, highly express various chemokines to promote leukocyte migration, tightly controlled by chemokine ligand-receptor interactions. Because the inhibition of these signaling pathways results in inflammatory response regulation, chemokines and their receptors could be promising targets for RA therapy. The blockade of various chemokines and/or their receptors has yielded prospective results in preclinical trials using animal models of inflammatory arthritis. However, some of these strategies have failed in clinical trials. Nonetheless, some blockades showed promising results in early-phase clinical trials, suggesting that chemokine ligand-receptor interactions remain a promising therapeutic target for RA and other autoimmune diseases.

Identification and validation of potential hub genes in rheumatoid arthritis by bioinformatics analysis

OBJECTIVE

Rheumatoid arthritis (RA) is considered to be a chronic immune disease pathologically characterized by synovial inflammation and bone destruction. At present, the potential pathogenesis of RA is still unclear. Hub genes are recognized to play a pivotal role in the occurrence and progression of RA.

METHODS

Firstly, we attempted to screen hub genes that are associated with RA, to clarify the underlying pathological mechanisms of RA, and to offer potential treatment methods for RA. We acquired these datasets (GSE12021, GSE55235, and GSE55457) of RA patients and healthy samples from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were recognized via R software. Then, Gene ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis were utilized to deeply explore the underlying biological functions and pathways closely associated with RA. In addition, a protein-protein interaction (PPI) network was built to further evaluate and screen for hub genes. Finally, on the basis of the results of PPI analysis, we confirmed the mRNA expression levels of five hub genes in the synovial tissue of rats modeled with RA.

RESULTS

In the human microarray datasets, LCK, JAK2, SOCS3, STAT1, and EGFR were identified as hub genes associated with RA by bioinformatics analysis. Furthermore, we verified the differential expression levels of hub genes in rat synovial tissues via qRT-PCR (P < 0.05).

CONCLUSIONS

Our findings suggest that the hub genes LCK, JAK2, SOCS3, STAT1, and EGFR might have vital roles in the progression of RA and may offer novel therapeutic treatments for RA.

Grape seed proanthocyanidin extract induces apoptotic and autophagic cell death in rheumatoid arthritis fibroblast-like synoviocytes

Objectives

In this study, we aimed to evaluate the association between grape seed proanthocyanidin extract (GSPE) and rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLSs) and to investigate whether GSPE induces cell death in RA-FLSs.

Materials and methods

The FLSs were isolated from RA synovial tissues. Cell viability and cell cycle staging were analyzed using a hemocytometer and flow cytometry. Caspase 3 and poly (ADP-ribose) polymerase (PARP) proteins were analyzed using Western blotting with z-VAD-fmk. Protein LC3 and polyubiquitin-binding protein p62 that were degraded by autophagy were evaluated using Western blotting with 3-methyladenine and chloroquine. Reactive oxygen species (ROS) were also evaluated.

Results

When RA-FLSs were treated with GSPE, cell viability decreased, the number of cells in sub-G1 and G2/M phases increased, and the expression of pro-PARP and pro-caspase 3 proteins decreased in a concentration-dependent manner. This result was offset, when the cells were co-treated with the pan-caspase inhibitor z-VAD-fmk. The reduced cell viability, increased expression of LC3-II protein, and reduced expression of p62 protein with GSPE treatment were offset, when RA-FLSs were co-treated with GSPE and autophagy inhibitors 3-methyladenine and chloroquine. The level of ROS in RA-FLSs treated with GSPE was significantly lower than treatment with N-acetyl-cysteine, a ROS inhibitor.

Conclusion

Our study results show that GSPE induces apoptotic and autophagic cell death and inhibites reactive oxygen species in RA-FLSs.

Treatment with the anti-CD20 monoclonal antibody rituximab mitigates gonadal disruptions in the collagen-induced arthritis in male DBA/1 J mouse model

Rheumatoid arthritis (RA), which is driven by persistent activation of the immune system, primarily affects the joints. Several reports have estimated the risk of gonadal disruptions in arthritic patients, with potential attributable risk factors such as treatments with the disease-modifying antirheumatic drugs and the influence of the disease itself. The FDA approved rituximab, a therapy for non-Hodgkin's lymphoma, for management of RA in February 2006. However, the influence of repeated treatment with rituximab on gonadal function in RA has not been reported yet. Thus, the aim of the presents study is to evaluate whether repeated treatment with the clinically relevant dose of rituximab may change the gonadal disruptions in collagen-induced arthritis in male DBA/1 J mouse, a model of RA. Testicular disruptions, as determined by the sperm DNA strand breaks, spermatocyte chromosomal analysis and spermiogram examination have been conducted by the use of standard techniques. Additionally, we aimed to test whether the anti-rheumatic effect of rituximab also decreases the cellular oxidant-antioxidant imbalance in arthritic male DBA/1 J mice. Repeated treatment of naïve control DBA/1 J mice with rituximab did not exhibit any significant deleterious effects. Moreover, repeated administration of rituximab to the arthritic DBA/1 J mice suppressed disease severity and decreased testicular disruptions. Rituximab treatment also diminished gonadal oxidative stress, through decreasing reactive oxygen species generation and restoring the reduced glutathione level in arthritic DBA/1 J mice. In conclusion, rituximab is a safe therapeutic agent and can mitigate gonadal disruptions induced by arthritis, which insinuates the importance for arthritic patients especially at reproductive age.

Suppression of NF-κB signaling by ECN in an arthritic model of inflammation

Background

The 7β-(3-ethyl-cis-crotonoyloxy)-1α-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (ECN), a sesquiterpenoid isolated from the Tussilago farfara Linneaus (Asteraceae), was evaluated against acute Carrageenan and chronic complete Freund’s adjuvant (CFA)-induced arthritis in mice.

Methods

Acute and chronic arthritis were induced by administering Carrageenan and CFA to the intraplantar surface of the mouse paw. Edema, mechanical allodynia, mechanical hyperalgesia, and thermal hyperalgesia were assessed in the paw. Similarly, histological and immunohistological parameters were assessed following arthritis induced by CFA. Antioxidants, inflammatory cytokines, and oxidative stress markers were also studied in all the treated groups.

Results

The ECN treatment significantly attenuated edema in the paw and elevated the nocifensive threshold following induction of this inflammatory model. Furthermore, ECN treatment markedly improved the arthritis index and distress symptoms, while attenuating the CFA-induced edema in the paw. ECN treatment also improved the histological parameters in the paw tissue compared to the control. At the same time, there was a significant reduction in edema and erosion in the ECN-treated group, as measured by radiographic analysis. Using the Comet’s assay, we showed that ECN treatment protected the DNA from chronic CFA-induced arthritis. Immunohistochemistry analysis showed a marked decrease in the expression level of p-JNK (phosphorylated C-Jun N-terminal kinase), NF-κB (Nuclear factor-kappa B), COX-2 (Cyclooxygenase-2), and TNF-α (Tumour necrosis factor-alpha) compared to the CFA-treated group. Biophysical analysis involving molecular docking, molecular dynamics simulations, and binding free energies of ECN were performed to explore the underlying mechanism.

Conclusion

ECN exhibited significant anti-inflammatory and anti-arthritic activity against Carrageenan and CFA-induced models.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03629-7.

Diabetic cardiomyopathy was attenuated by cinnamon treatment through the inhibition of fibro-inflammatory response and ventricular hypertrophy in diabetic rats

Diabetic cardiomyopathy (DCM) is a chronic complication of diabetes that emphasizes the urgency of developing new drug therapies. With an illustrious history in traditional medicine to improve diabetes, cinnamon has been shown to possess blood lipids lowering effects and antioxidative and anti-inflammatory properties. However, the extent to which it protects the diabetic heart has yet to be determined. Forty-eight rats were administered in the study and grouped as: control; diabetic; diabetic rats given 100, 200, or 400 mg/kg cinnamon extract, metformin (300 mg/kg), valsartan (30 mg/kg), or met/val (combination of both drugs), via gavage for six weeks. Fasting blood sugar (FBS) and markers of cardiac injury including creatine kinase-muscle/brain (CK-MB), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were evaluated in blood samples. Malondialdehyde (MDA) levels, the total contents of thiol, superoxide dismutase (SOD), and catalase (CAT) activities were measured. Histopathology study and gene expression measurement of angiotensin II type 1 receptor (AT1), atrial natriuretic peptide (ANP), beta-myosin heavy chain (β-MHC), and brain natriuretic peptide (BNP) were done on cardiac tissue. FBS and cardiac enzyme indicators were reduced in all treated groups. A reduction in MDA level and enhancement in thiol content alongside with increase of SOD and CAT activities were observed in extract groups. The decrease of inflammation and fibrosis was obvious in treated groups, notably in the high-dose extract group. Furthermore, all treated diabetic groups showed a lowering trend in AT1, ANP, β-MHC, and BNP gene expression. Cinnamon extract, in addition to its hypoglycemic and antioxidant properties, can prevent diabetic heart damage by alleviating cardiac inflammation and fibrosis. PRACTICAL APPLICATIONS: This study found that cinnamon extract might protect diabetic heart damage by reducing inflammation and fibrosis in cardiac tissue, in addition to lowering blood glucose levels and increasing antioxidant activity. Our data imply that including cinnamon in diabetic participants' diets may help to reduce risk factors of cardiovascular diseases.

D-Mannose Suppresses γδ T Cells and Alleviates Murine Psoriasis

Psoriasis is a chronic skin disorder associated with multiple sequelae, such as psoriatic arthritis and cardiovascular diseases. Increasing evidence has shown that γδ T cells, as sources of IL-17A, play critical roles in psoriatic inflammations. However, there still lack effective ways to manipulate these pathogenic γδ T cells, which are less well studied than αβ T cells. The present study aims to characterize the phenotype of γδ T cells and evaluate the impact of D-mannose (a C-2 epimer of glucose) on γδ T cell-mediated psoriasis. We found that skin-draining LN γδ T cells underwent robust proliferation and acquired an IL-17-producing phenotype during psoriasis. The transcriptomic profiles of these psoriatic γδ T cells had elevated glycolytic signatures. Importantly, D-mannose treatment suppressed the γδ T cell reaction and successfully alleviated the local and systematic inflammation induced by imiquimod. The decreased AKT/mTOR/HIF-1α signaling and glycolytic ability may contribute to the suppression of γδ T cells achieved by D-mannose. Our study increased understanding of γδ T cells in psoriasis and promoted D-mannose utilization as a potential clinical application for autoimmune diseases driven by γδ T cells.

Anti-Osteoporotic Effect of Lactobacillus brevis AR281 in an Ovariectomized Mouse Model Mediated by Inhibition of Osteoclast Differentiation

Simple Summary

Osteoporosis-related fractures are among the most common complications found in postmenopausal adults, which results in considerable economic impacts. Most treatments for osteoporosis increase bone formation or decrease bone resorption. While estrogen replacement therapy may be the gold standard for the treatment of osteoporosis, it also carries an increased risk of cardiac events and strokes in women. Thus, it is important to seek a safe and effective treatment method. Gut homeostasis is demonstrably linked to bone health. Probiotics are widely known to modulate gut microbiota, but with large strain differences. Our findings showed a strain of Lactobacillus brevis AR281 with an anti-osteoporotic property in ovariectomized mice, which may provide a new way to prevent osteoporosis.

Abstract

Osteoporosis is a global disease characterized by weakened bone microarchitecture, leading to osteoporotic fractures. Estrogen replacement therapy is the traditional treatment for osteoporosis but carries with it an increased risk of cardiac events. In search of a safe and effective treatment, we used Lactobacillus brevis AR281, which has anti-inflammatory properties, to conduct a 7-week experiment, investigating its inhibitory effects on osteoporosis in an ovariectomized (ovx) mouse model. The results demonstrated that AR281 significantly improved bone microarchitecture and biomechanical strength in ovx mice by attenuating bone resorption. AR281 significantly decreased the critical osteoclast activator, the ratio of the receptor activator for nuclear factor kappa B (NF-κB) ligand (RANKL) to osteoprotegerin, and pro-inflammatory osteoclastogenic mediators, such as IL-1, IL-6, and IL-17, which can increase the RANKL expression. Moreover, AR281 modulated intestinal microbiota in ovx mice increased the abundance of Akkermansia, which is responsible for the improvement of gut epithelial barrier integrity. In an in vitro trial, AR281 suppressed the number of osteoclasts differentiated from the osteoclast precursor RAW264.7 cells caused by RANKL through the tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6)/NF-κB/nuclear factor of activated T cells c1 (NFATc1) pathway. Therefore, AR281 may be a natural alternative for combating osteoporosis.

The Study on the Regulation of Th Cells by Mesenchymal Stem Cells Through the JAK-STAT Signaling Pathway to Protect Naturally Aged Sepsis Model Rats

Sepsis is the leading cause of death among patients, especially elderly patients, in intensive care units worldwide. In this study, we established a sepsis model using naturally aged rats and injected 5×10⁶ umbilical cord-derived MSCs via the tail vein. Each group of rats was analyzed for survival, examined for biochemical parameters, stained for organ histology, and analyzed for the Th cell subpopulation ratio and inflammatory cytokine levels by flow cytometry. Western blotting was performed to detect the activity of the JAK-STAT signaling pathway. We designed the vitro experiments to confirm the regulatory role of MSCs, and verified the possible mechanism using JAK/STAT inhibitors. It was revealed from the experiments that the 72 h survival rate of sepsis rats treated with MSCs was significantly increased, organ damage and inflammatory infiltration were reduced, the levels of organ damage indicators were decreased, the ratios of Th1/Th2 and Th17/Treg in peripheral blood and spleen were significantly decreased, the levels of pro-inflammatory cytokines such as IL-6 were decreased, the levels of anti-inflammatory cytokines such as IL-10 were increased, and the levels of STAT1 and STAT3 phosphorylation were reduced. These results were validated in in vitro experiments. Therefore, this study confirms that MSCs can control the inflammatory response induced by sepsis by regulating Th cells and inflammatory factors, and that this leads to the reduction of tissue damage, protection of organ functions and ultimately the improvement of survival in aged sepsis model rats. Inhibition of the JAK-STAT signaling pathway was surmised that it may be an important mechanism for their action.

Extracts of Andrographis paniculata (Burm.f.) Nees Leaves Exert Anti-Gout Effects by Lowering Uric Acid Levels and Reducing Monosodium Urate Crystal-Induced Inflammation

Andrographis paniculata (Burm.f.) Nees has been found to have anti-inflammatory and immunostimulatory effects. This study was to investigate antihyperuricemic and anti-inflammatory effects of A. paniculata leaf extracts. Andrographolide, 14-deoxy-11,12-didehydroandrographolide, and neoandrographolide were quantified in 80% ethanol (EtOH80) and water extracts using High Performance Liquid Chromatography (HPLC) analysis. Antihyperuricemic activity was evaluated using a spectrophotometric in vitro inhibitory xanthine oxidase (XO) assay. The most active extract and andrographolide were further investigated in a hyperuricemic rat model induced by potassium oxonate to determine serum uric acid levels, liver XO activity, followed by Western blot analysis for renal urate transporter URAT1, GLUT9, and OAT1 to investigate the excretion of uric acid via kidney. Anti-inflammatory activity was assessed by in vitro interleukin assay for interleukin (IL-1α, IL-1β, IL-6, IL-8), and tumor necrosis factor (TNF-α) in monosodium urate (MSU) crystal-induced human fibroblast-like synoviocyte (HFLS) cells using ELISA-kits, followed by Western blot analysis for the expression of MyD88, NLRP3, NF-κB p65, and caspase-1 proteins to investigate the inflammation pathway. In vivo assay of the most active extract and andrographolide were performed based on the swelling rate and inhibition of pro-inflammatory mediator release from synovial fluid of a rat knee joint induced by MSU crystals. The results showed that the EtOH80 extract had a greater amount of andrographolide (11.34% w/w) than the water extract (1.38% w/w). In the XO inhibitory activity, none of the samples exhibited greater than 50% inhibition. However, in a rat model, EtOH80 extract (200 mg/kg/day) and andrographolide (30 mg/kg/day) decreased serum uric acid levels and reduced liver XO activity, reduced the protein expression levels of URAT1 and GLUT9, and restored the decrease in OAT1 levels. In the in vitro anti-inflammatory study, EtOH80 extract and andrographolide significantly decreased production of IL-1α, IL-1β, IL-6, and TNF-α, as well as inhibited the synthesis of MyD88, NLRP3, NF-κB p65, and caspase-1 in a concentration-dependent manner, almost comparable to dexamethasone. The EtOH80 extract (200 mg/kg/day) and andrographolide (30 mg/kg) significantly decreased swelling rate and IL-1α, IL-1β, IL-6, and TNF-α in the synovial fluid of rat models in a time-dependent manner, comparable to indomethacin (3 mg/kg/day). In conclusion, the findings show that EtOH80 extract has a substantial anti-gout effect by lowering uric acid levels and suppressing pro-inflammatory mediator production due to the andrographolide content, that might be beneficial in the treatment of gouty-inflammation.

Bacillus subtilis BN strain promotes Th1 response via Toll-like receptor 2 in polarized mouse M1 macrophage

Bacillus subtilis BN strain (BN strain) was isolated from natto, a traditional Japanese fermented soybean food product. The present study investigated the Th1 responses of the BN strain on a mouse macrophage cell line, J774.1. In cell cultures, the BN strain (spore cell cultured in Schaeffer's sporulation media) significantly increased the production of interleukin (IL-)12 protein. The BN strain induced the mRNA expression of M1 polarization genes, such as inducible nitric oxide synthase and IL-12p40 mRNA, and suppressed the mRNA expression of intracellular marker genes of M2 polarization, such as arginase 1 mRNA. The BN strain downregulated the mRNA expression of Toll-like receptor 4 (TLR4), while it upregulated the mRNA expression of TLR2, MyD88, and nuclear factor kappa B (NF-κB). The production of IL-12 protein induced by the BN strain was decreased by inhibitors of MyD88, NF-κB, and IκB kinase. Moreover, the production of IL-12 was strongly suppressed by neutralizing antibody against TLR2. These results suggest that the BN strain promotes Th1 response via TLR2 signal in mouse M1 macrophage. PRACTICAL APPLICATIONS: Bacillus subtilis is known to have beneficial effects for the host. B. subtilis BN stain (BN strain) was isolated from natto, a traditional Japanese fermented soybean food product. The effects of the BN strain on the Th1 response in macrophage cell cultures were investigated in this work. We found that the spore cells of BN strain promoted the production of Th1-type cytokine, and induced macrophage M1 polarization via Toll-like receptor 2. This study can serve as a significant reference for the development of functional food and feed with immunostimulatory effects. Over time, new food and feed products containing the BN strain may emerge, such as Juice, powder, and tablet.

Venetoclax enhances NK cell killing sensitivity of AML cells through the NKG2D/NKG2DL activation pathway

BACKGROUND

Venetoclax, a selective B-cell lymphoma-2 (BCL2) inhibitor, has a potential therapeutic effect when combined with demethylating agents in the first-line setting of unfit elderly patients with acute myeloid leukaemia (AML); however, efficacy is still limited in refractory/recurrent AML. Therefore, exploration of a suitable novel treatment scheme is urgently needed.However, combining venetoclax with NK cell-based immunotherapy has not been studied.

METHODS

The cytotoxicity of NK cell combined with venetoclax was assessed in vitro using flow cytometry. Venetoclax-induced natural killer group 2 member D (NKG2D) ligand (NKG2DL) expression was detected by flow cytometry and western blotting. Mechanisms underlying venetoclax-induced NKG2DL expression were found by GSE127200 analysis and investigated using real-time PCR (Q-PCR) and western blotting.

RESULTS

Flow cytometric analysis showed that combining venetoclax with NK cells produced synergistic anti-leukaemia effects similar to those of venetoclax + azacitidine. Venetoclax could render AML cell lines and primary AML cells sensitive to NK cell killing by promoting NK cell degranulation, NK-AML cell recognition and NK cell secretion of interferon (IFN)-γ and granzyme B. The synergistic effect resulted from venetoclax-induced NKG2DL upregulation in AML cells and could be undermined by blocking NKG2D on NK cells. This finding suggests that venetoclax enhances NK cell killing activity by activating the NKG2D/NKG2DL ligand-receptor pathway. Furthermore, the nuclear factor-kappa-B (NFKB) signalling pathway was involved in venetoclax-induced NKG2DL upregulation.

CONCLUSIONS

Collectively, our data confirm that venetoclax combined with NK cells induces synergistic AML cell cytolysis and preliminarily revealed that venetoclax could selectively induce NKG2DLs on AML cells via NFKB signalling pathway.

Biological Anti-TNF-α Therapy and Markers of Oxidative and Carbonyl Stress in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) as a chronic inflammatory disease is associated with oxidative stress. Drugs targeting tumor necrosis factor-alpha (TNF-α) ameliorate inflammation and symptoms of RA in most patients. Whether markers of oxidative stress can be used for monitoring of treatment effects is unknown. The aim of our study was to analyze the effects of anti-TNF-α treatment on oxidative stress in plasma and saliva of patients with RA. Samples were collected from 26 patients with RA at baseline as well as 3 and 6 months after starting the anti-TNF-α treatment. Thiobarbituric acid-reacting substances (TBARS), advanced oxidation protein products (AOPP), advanced glycation end products (AGEs), and fructosamine were quantified using spectrophotometry and spectrofluorometry in plasma. TBARS were measured also in saliva. The disease activity score (DAS28) was used to assess the clinical status of patients. No significant dynamic changes were found except plasma TBARS that decreased continuously. At 6 months after starting the treatment, plasma TBARS were lower by 39% in comparison to baseline (p = 0.006). Salivary concentrations of TBARS did not reflect the dynamics in plasma. Although a trend was observed (r = 0.33), a significant correlation between plasma TBARS and DAS28 was not found. Our results indicate that anti-TNF-α treatment decreases plasma TBARS as a marker of lipid peroxidation. However, the lack of a significant correlation with DAS28 suggests that it cannot be used for monitoring of treatment. Other markers of oxidative stress and antioxidant capacity with lower biological variability should be tested in future studies.

Euphorbia Factor L2 ameliorates the Progression of K/BxN Serum-Induced Arthritis by Blocking TLR7 Mediated IRAK4/IKKβ/IRF5 and NF-kB Signaling Pathways

Toll like receptor (TLR)s have a central role in regulating innate immunity and their activation have been highlighted in the pathogenesis of rheumatoid arthritis (RA). EFL2, one of diterpenoids derived from Euphorbia seeds, is nearly unknown expect for its improving effect on acute lung injury. Our present study aimed to investigate EFL2's pharmacokinetic features, its therapeutic effect on rheumatoid arthritis, and explored the potential anti-arthritic mechanisms. K/BxN serum transfer arthritis (STA) murine model was used to assess EFL2's anti-arthritic effects. We also applied UPLC-MS method to measure the concentrations of EFL2 in plasma. The inhibitory effects of this compound on inflammatory cells infiltration and activation were determined by flow cytometry analysis and quantitative real-time polymerase chain reaction (qRT-PCR) in vivo, and immunochemistry staining and ELISA in murine macrophages and human PBMCs in vitro, respectively. The mechanism of EFL2 on TLRs mediated signaling pathway was evaluated by PCR array, Western blot, plasmid transfection and confocal observation. Intraperitoneal (i.p.) injection of EFL2, instead of oral administration, could effectively ameliorate arthritis severity of STA mice. The inflammatory cells migration and infiltration into ankles were also significantly blocked by EFL2, accompanied with dramatically reduction of chemokines mRNA expression and pro-inflammatory cytokines production. In vivo PCR microarray indicated that EFL2 exerted anti-arthritis bioactivity by suppressing TLR7 mediated signaling pathway. In vitro study confirmed the inhibitory effects of EFL2 on TLR7 or TLR3/7 synergistically induced inflammatory cytokines secretion in murine macrophages and human PBMCs. In terms of molecular mechanism, we further verified that EFL2 robustly downregulated TLR7 mediated IRAK4-IKKβ-IRF5 and NF-κB signaling pathways activation, and blocked IRF5 and p65 phosphorylation and translocation activity. Taken together, our data indicate EFL2's therapeutic potential as a candidate for rheumatoid arthritis and other TLR7-dependent diseases.

Protease-Activated Receptor-1 Antagonist Protects Against Lung Ischemia/Reperfusion Injury

Protease-activated receptor (PAR)-1 is a thrombin-activated receptor that plays an essential role in ischemia/reperfusion (IR)-induced acute inflammation. PAR-1 antagonists have been shown to alleviate injuries in various IR models. However, the effect of PAR-1 antagonists on IR-induced acute lung injury (ALI) has not yet been elucidated. This study aimed to investigate whether PAR-1 inhibition could attenuate lung IR injury. Lung IR was induced in an isolated perfused rat lung model. Male rats were treated with the specific PAR-1 antagonist SCH530348 (vorapaxar) or vehicle, followed by ischemia for 40 min and reperfusion for 60 min. To examine the role of PAR-1 and the mechanism of SCH530348 in lung IR injury, western blotting and immunohistochemical analysis of lung tissue were performed. In vitro, mouse lung epithelial cells (MLE-12) were treated with SCH530348 or vehicle and subjected to hypoxia-reoxygenation (HR). We found that SCH530348 decreased lung edema and neutrophil infiltration, attenuated thrombin production, reduced inflammatory factors, including cytokine-induced neutrophil chemoattractant-1, interleukin-6 and tumor necrosis factor-α, mitigated lung cell apoptosis, and downregulated the phosphoinositide 3-kinase (PI3K), nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways in IR-injured lungs. In addition, SCH530348 prevented HR-induced NF-κB activation and inflammatory chemokine production in MLE12 cells. Our results demonstrate that SCH530348 exerts protective effects by blocking PAR-1 expression and modulating the downstream PI3K, NF-κB and MAPK pathways. These findings indicate that the PAR-1 antagonist protects against IR-induced ALI and is a potential therapeutic candidate for lung protection following IR injury.

Characteristics of Ang-(1-7)/Mas-Mediated Amelioration of Joint Inflammation and Cardiac Complications in Mice With Collagen-Induced Arthritis

Objectives

Rheumatoid arthritis (RA) is a disabling disease with a high incidence that is regularly accompanied by cardiovascular complications. Several studies have suggested that renin–angiotensin–aldosterone system (RAAS) is closely associated with RA. The aim of this study was to investigate the mechanisms underlying Angiotensin-(1–7) [Ang-(1–7)] and its Mas receptor agonist (AVE0991) on joint inflammation and cardiac complications in a collagen-induced arthritis (CIA) model.

Methods

Collagen type II was injected into DBA/1 mice to construct an arthritis model. CIA mice were treated with Ang-(1–7) (2.0 mg/kg intraperitoneally) and AVE0991 (3.0 mg/kg intraperitoneally). The serum levels of inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1 β, IL-6, and C-reactive protein (CRP)] were determined by ELISA. The mitogen-activated protein kinase (MAPK) and nuclear factor-kappaB (NF-κB) signaling pathways in joint tissues and the transforming growth factor (TGF)-β/Smad pathway and levels of α-Smooth muscle action (SMA) and β-myosin heavy chain (MHC) protein expression in cardiac tissues were assessed by western blots. The levels of TGF-β/Smad pathway, α-SMA, and β-MHC RNA in cardiac tissues were analyzed by real time-PCR. The levels of receptor activator of nuclear factor kappa ligand (RANKL) and promoting matrix metalloproteinase (MMP)-3 expression in the ankle joints were detected by immunohistochemistry and real time-PCR.

Results

Ang-(1–7) and AVE0991 reduced the levels of inflammatory cytokines and inhibited the MAPKs and NF-κB signaling pathways in ankle joint tissues, reduced RANKL and MMP3 expression, and ameliorated local joint inflammation and bone destruction compared with the control group. In addition, Ang-(1–7) and AVE0991 attenuated the TGF-β/Smad signaling pathway, reduced the levels of α-SMA and β-MHC expression, and diminished inflammatory cell infiltration into the myocardial interstitium and myocardial interstitial fibrosis in the hearts of CIA mice.

Conclusions

Ang-(1–7) alleviated joint damage caused by inflammation likely through the attenuation of NF-κB and MAPK pathways and ameliorated inflammation-induced cardiac fibrosis and activation of the TGF-β/Smad pathway. Moreover, Ang-(1–7) was likely mediated through the Mas receptor. This study provides theoretical evidence for exploring novel clinical therapeutic approaches for RA and its cardiac complications.

KLF4 Promotes Diabetic Chronic Wound Healing by Suppressing Th17 Cell Differentiation in an MDSC-Dependent Manner

OBJECTIVES

Diabetic wound inflammation deficiencies lead to ulcer development and eventual amputation and disability. Our previous research demonstrates that myeloid-derived suppressor cells (MDSCs) accumulate during inflammation and promote chronic wound healing via the regulation of Kruppel-like factor 4 (KLF4). In this study, we aimed to investigate the potential roles of MDSCs and KLF4 in diabetic wound healing.

METHODS

An ob/ob mouse pressure ulcer (PU) model was used to evaluate the process of wound healing. The expression levels of KLF4 and IL-17A were measured by real-time PCR, and the population of MDSCs and Th17 cells was measured by flow cytometry. The levels of cytokines were determined by an immunosuppression assay.

RESULTS

KLF4 deficiency in the diabetic PU model resulted in decreased accumulation of MDSCs, increased expansion of Th17 cells, and significantly delayed wound healing. Conversely, KLF4 activation by APTO-253 accelerated wound healing accompanied by increased MDSC populations and decreased numbers of Th17 cells. MDSCs have been proven to mediate Th17 differentiation via cytokines, and our in vitro data showed that elevated KLF4 expression in MDSCs resulted in reduced Th17 cell numbers and, thus, decreased levels of cytokines indispensable for Th17 differentiation.

CONCLUSIONS

Our study revealed a previously unreported function of KLF4-regulated MDSCs in diabetic wound healing and identified APTO-253 as a potential agent to improve the healing of pressure ulcers.