Rat Model Of Rheumatoid Arthritis Research Articles

Preparation of meloxicam-salicylic acid co-crystal and its application in the treatment of rheumatoid arthritis

Meloxicam is a non-steroidal anti-inflammatory drug that can selectively inhibit cyclooxygenase 2 (COX-2), showing high anti-inflammatory activity, low gastrointestinal and renal side effects. However, the low solubility and slow dissolution rate limit its role in rapid pain relief. In this paper, using meloxicam as the active drug molecule and salicylic acid as the co-crystal former, the meloxicam-salicylic acid co-crystal (MLX-SLC CoC) was prepared by the reaction crystallization method. The co-crystal was characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The dissolution curve of the co-crystal was determined, and the result showed that the formation of drug co-crystal enhanced the solubility and dissolution rate of MLX. The oil-water partition coefficient of the MLX-SLC CoC was determined, and the results showed that the oil-water partition coefficient of the co-crystal was similar to that of pure MLX. The gel prepared by MLX-SLC CoC was used to study its in vitro release and transdermal penetration characteristics were investigated, which showed that the transdermal penetration of the drug was increased without affecting its in vitro release. Preparation of gel in the form of MLX-SLC CoC increased the drug concentration in the gel. Finally, the therapeutic effect of the gel on arthritis was preliminarily studied by establishing a rheumatoid arthritis rat model.

Investigation of the effects of safranal on the experimentally created rheumatoid arthritis model in rats.

Rheumatoid arthritis (RA) is a systemic chronic disease characterized by inflammation and synovitis. More effective treatment methods with less side effects need to be developed. In this context, current study investigated the therapeutic effects of safranal in a model of complete Freund's adjuvant (CFA)-induced RA. The control group was given 1 ml of saline orally starting from the 8th day, and 0.2 ml of CFA was given to the RA, RA + Safranal and RA + Methotrexate (MTX) groups on the 0th day of the experiment. Starting from the 8th day of the experiment, 1 ml of saline was given to the RA group, safranal was given at 200 mg/kg of body weight to the RA + MTX group, and 3 mg/kg of MTX to the RA + MTX group twice a week. The results showed that weight gain decreased in the RA group compared to the control group while arthritis index score, thymus index, and planter temperature were found to be increased. Additionally, a deterioration in blood parameters, an increase in alanine aminotransferase, aspartate aminotransferase, urea, creatinine, C-reactive protein, and malondialdehyde levels, and a decrease in reduced glutathione levels and glutathione peroxidase and catalase (CAT) activities were seen while tumor necrosis factor-α, interleukin-6 (IL-6), cyclooxygenase-2, nuclear factor kappa B levels were found to be increased. However, the safranal had a regulatory effect on all the values, except IL-6 and CAT, and blood parameters. Moreover, histopathological examination revealed that safranal reduced inflammatory cell infiltration and edema.

Exosomes derived from fibrinogen-like protein 1-overexpressing bone marrow-derived mesenchymal stem cells ameliorates rheumatoid arthritis

ABSTRACT Rheumatoid arthritis (RA) is a most common chronic joint disease belonging to inflammatory autoimmune disease. The aim of this study was to determine the role and mechanism of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes and fibrinogen-like protein 1 (FGL1) overexpression exosomes shuttled by BMSCs (FGL1-Exos) on RA. All of the exosomes were visualized by transmission electron microscope (TEM) and the characteristic proteins were detected by western blot. To investigate the therapeutic effect of FGL1-Exos, RA-FLSs were activated by TNF-α and RA rat model was established by collagen incomplete Freund’s adjuvant. Cell viability, apoptosis, inflammation factors, and protein levels were detected by CCK-8, flow cytometry, enzyme-linked immunosorbent assay and western blot, respectively. Hematoxylin and eosin and safranin O staining were used to detect the histopathology changes. Cell apoptosis and FGL1 expression in knee joint were detected by immunofluorescence. The results showed that FGL1-Exos could inhibit the cell viability meanwhile increase the cell apoptosis in RA-FLSs. Meanwhile, FGL1-Exos could effectively suppress the inflammation score, joint destruction, and inflammatory response in RA rat model. FGL1-Exos directly inhibited cell apoptosis of RA-FLSs and RA rat model by suppressing the inflammatory cytokines, specific rheumatoid markers, immunological markers meanwhile meditating the NF-κB pathway. Our results indicate that FGL1 was a therapeutic potential target in RA therapy.

Effect of moxibustion on N-methyl-D-aspartate receptor subtype 2B expression in hippocampus of rheumatoid arthritis model rats

Effect of moxibustion on N-methyl-D-aspartate receptor subtype 2B expression in hippocampus of rheumatoid arthritis model rats

Metabolic characteristics and pharmacokinetic differences of Qiwei Tongbi oral liquid in rheumatoid arthritis rats.

Qiwei Tongbi oral liquid (QWTB), a classical traditional Chinese medicine formula, is widely used to treat arthritis-related diseases in clinical practice. Currently, in vivo metabolic characteristics and pharmacokinetic studies are lacking. This study analyzed the prototype components of QWTB absorbed in the blood and their metabolic transformation process after intragastric administration and compared the differences in pharmacokinetic properties between healthy and rheumatoid arthritis model rats. In sum, 17 prototype components and 21 related metabolites were identified in the plasma and urine of the treated rats. Metabolites were derived from sinomenine and magnoflorine. Through systematic methodology verification, an accurate and stable detection method for sinomenine and magnoflorine in plasma samples was established and applied to pharmacokinetic research of QWTB. At the three dose levels, the AUC0-∞ (area under the curve) of the two components showed a good positive correlation with the dose (R2 > 0.9). Compared with healthy rats, the Tmax , t1/2z , and AUC of sinomenine were markedly increased, and Cmax was decreased in rheumatoid arthritis model rats, indicating that the rate of absorption and elimination rate decreased, but the body exposure increased. However, there were no significant differences in the pharmacokinetic parameters of magnoflorine under healthy and pathological conditions. In summary, the main active ingredients of QWTB are sinomenine and magnoflorine, which exhibit linear kinetic characteristics within a set dose range, and the rheumatoid arthritis pathological state is more conducive to the absorption and efficacy of sinomenine. The results of this study demonstrate the rationality of the clinical application of the QWTB.

Retraction.

Retraction: "CCR5 silencing reduces inflammatory response, inhibits viability, and promotes apoptosis of synovial cells in rat models of rheumatoid arthritis through the MAPK signaling pathway," by You-Yu Lan, You-Qiang Wang, Yi Liu, J Cell Physiol. 2019; 18748-18762: The above article, published online on 07 May 2019 in Wiley Online Library (https://doi.org/10.1002/jcp.28514), has been retracted by agreement between the journal's Editor in Chief, Prof. Dr. Gregg Fields, and Wiley Periodicals LLC. The retraction has been agreed after the authors asked for a correction. An investigation revealed duplications and inconsistencies in several image elements. Thus, the editors consider the conclusions of this article to be invalid. The authors were not available for a final confirmation of the retraction.

Cytokine Regulation and Fast Inflammation Resolution in Early Rheumatoid Arthritis by Cerium-Modified Gold Nanoclusters.

Rheumatoid arthritis (RA) is an incurable chronic disorder that may induce autoinflammation and serious pain in the joints. Early diagnosis and treatment are important for RA prognosis. However, there is a lack of effective and objective diagnostic approaches. Levels of several immunity cytokines were found to change for patients with early RA, including IL-6, TNF-α, and IL-17 in serum. We assumed a combined change of these cytokines could predict early RA, and a total of 37 outpatients were found. After these patients with early symptoms had been followed for more than one year, 32 clinical cases of RA were diagnosed. The accuracy rate of the current method is >86%. We assumed the symptom relief could be achieved by regulating these cytokines and serum lipid-associated indicators. Thereafter, (R)-dihydrolipoic acid (R-DHLA)-stabilized gold nanoclusters (AuNCs) without (R-DHLA-AuNCs) and with cerium modification (R-DHLA-AuNCs-Ce) were employed for treatment of the RA rat model in vitro and in vivo. R-DHLA-AuNCs-Ce exhibited extraordinary reactive oxygen species-scavenging and anti-inflammation effects by regulating macrophage polarization, which was found to be more effective than methotrexate. The inflammation response of the joint microenvironment was also reduced with an exciting efficiency. By complex analysis of the pro-inflammatory cytokines and activity period indicators in vivo and in vitro, we concluded that macrophage-mediated inflammation exacerbated autoimmunity, which fully relieved the symptoms after administration of R-DHLA-AuNCs-Ce to RA rats.

Effect of Acupuncture Stimulation on Improving the Immunity of Synovial Tissue in Rheumatoid Joints via MAPK Pathway

Purpose: Acupuncture treatment of rheumatoid arthritis (RA) has a long history and has been widely recognized in the medical community. However, its mechanism of action still is rarely uncovered. In the present study, the effects of acupuncture on the immune function and MAPK pathway in synovial tissue of rats with RA were investigated; it aimed to explore the effect and mechanism of acupuncture on alleviating RA.<br/> Methods: Rats were randomly divided into control, model and acupuncture groups, 15 rats each group, and RA rat model was induced via bovine type II collagen in complete Freund's adjuvant. The acupuncture group received "Zusanli" and "Shenshu" warm acupuncture treatment on the first day after modeling, acupuncture stimulation once a day for 21 days. The rat weight and degree of joint swelling were recorded and calculated. The ankle joint histopathology was observed by H&E staining. Serum inflammatory cytokines were detected using ELISA. An automatic biochemical analyzer was used to test serum IgG, IgM and IgA levels. Transcription factors T-bet, GATA3, RORγT, Foxp3 mRNA were monitored through RT-qPCR technology. Further, the expression of key targets of MAPK signal or phosphorylation in synovial tissue were determined using Western blotting.<br/> Results: Acupuncture relieved the joint swelling and weight loss of RA rats, ameliorated the pathological damage of the ankle joint, significantly increased the serum IgG, IgM, IgA and T-bet, and Foxp3 levels, and reduced the levels of IL-1β, IL-6, TNF-α, GATA3, and RORγT; down-regulated synovial tissue p-p38MAPK, p-JNK, and p-ERK1/2 levels and protein phosphorylation ratio (P <0.05).<br/> Conclusion: Acupuncture stimulation can improve the joint damage and promote the immune function of RA rats, possibly via blocking the expression of MAPK pathway in synovial tissue. This study provides a scientific and promising reference for acupuncture further in the clinical strategy of RA.

Effects of Muscone on Cartilage Morphology and Matrix Metalloproteinases-3 (MMP-3h) and Matrix Metalloproteinases-9 (MMP-9) Expression in Rheumatoid Arthritis Rat Models

Aim: To discuss Muscone treatment in Rheumatoid Arthritis Rat Models and relative mechanisms. Materials and methods: Dividing 36 rats as 4 groups as Normal, Model, DMSO and Muscone groups (n = 9). Rats of Model, DMSO and Muscone groups were made Rheumatoid Arthritis model. Muscone group were treated with 2 mg/kg Muscone after modeling. HE staining and Masson staining were used to observe the morphological changes of cartilage tissue, measuring MMP-3 and MMP-9 expression by RT-PCR, Western Blotting (WB) and Immunohistochemistry (IHC). Results: Compared with Model group, the pathological changes of Muscone group was significantly improved and average optical density of collagen fibers was significantly depressed (P < 0.001, respectively) via MMP-3 and MMP-9 proteins significantly depressing (P < 0.001, respectively). Conclusion: Muscone improved Rheumatoid Arthritis by depressing MMP-3 and MMP-9 proteins in vivo study.

Galangin alleviates rheumatoid arthritis in rats by downregulating the phosphatidylinositol 3-kinase/protein kinase B signaling pathway

ABSTRACT Rheumatoid arthritis (RA) is a chronic autoimmune disease that greatly affect patients’ quality of life. Galangin extract is renowned for its anti-proliferative and anti-oxidative characteristics. However, galangin cytotoxicity studies are presently inadequate. We aimed to investigate the therapeutic potential of galangin on RA by investigating the PI3K/AKT signaling pathway.Fibroblast-like synovial cells (FLSs) were exposed to lipopolysaccharide (LPS) to establish an RA model in vitro. An ELISA assay was used to detect the levels of IL-1β, TNF-α, and IL-6. Cell viability and apoptosis were determined by CCK8/EdU and flow cytometry assays. A western blot assay was used to analyze the protein expression levels. An RA rat model was established to evaluate the function of galangin through histopathological examination. Our results found that galangin induced apoptosis, inhibited cell proliferation, and increased cell invasion of rheumatoid arthritis fibroblast-like synovial cells (RAFLSs). Galangin inactivated the PI3K/AKT signaling pathway and the inflammatory response. An agonist of PI3K signaling, 740Y‐P, restored the cellular functions of RAFLSs. Moreover, galangin suppressed the development of RA in vivo. Galangin effected its anti-arthritic influence through the PI3K/AKT signaling pathway. Galangin has potential as an alternative treatment for RA.

Paeoniflorin-6′-o-benzene sulfonate ameliorates the progression of adjuvant-induced arthritis by inhibiting the interaction between Ahr and GRK2 of fibroblast-like synoviocytes

Aryl hydrocarbon receptor (Ahr) is thought to be a crucial factor that regulates immune responses, which may be involved in the pathogenesis of autoimmune inflammation including rheumatoid arthritis (RA). The results of our group in recent years have shown that Paeoniflorin-6′-O-benzene sulfonate (code: CP-25), a novel ester derivative of paeoniflorin, has a good effect on improving RA animal models. However, whether the anti-arthritis effect of CP-25 is related to Ahr remains unclear. Here, we showed that CP-25 treatment ameliorated adjuvant-induced arthritis (AA), a rat model of RA, by inhibiting Ahr-related activities in fibroblasts like synoviocytes (FLS). AA rats were treated with CP-25 or paroxetine from days 17 to 33 after immunization. We showed that CP-25 alleviated arthritis symptoms and the pathological changes. Treatment with CP-25 decreased the expression of Ahr in the synovium of AA rats. CP-25 inhibited the expression of Ahr and the G protein-coupled receptor kinase 2 (GRK2) as well as the co-expression of GRK2 with Ahr in FLS of AA rats. Furthermore, CP-25 down-regulated the production of Kyn in FLS of AA rats. These results suggested that CP-25 may inhibit the expression and activation of Ahr. Besides, treatment with CP-25 reduced the proliferation and migration of MH7A caused by Ahr activation. In addition, we also demonstrated that CP-25 down-regulated the total and nuclear expression of Ahr and the expression of GRK2 in Kyn-treated MH7A. Moreover, the co-expression and co-localization of Ahr and GRK2in Kyn-treated MH7A were also repressed by CP-25. The data presented here demonstrated that CP-25 suppressed FLS dysfunction in rats with AA, which were associated with reduced Ahr activation and the interaction between Ahr and GRK2.

Exosomal microRNA-140-3p from human umbilical cord mesenchymal stem cells attenuates joint injury of rats with rheumatoid arthritis by silencing SGK1

ObjectiveOver the years, microRNAs (miRNAs) have been involved in the pathogenesis of rheumatoid arthritis (RA). We aim to investigate the role of human umbilical cord mesenchymal stem cells (HUCMSCs)-derived exosomal miR-140-3p in RA development.MethodsExosomes(exo) were isolated from human umbilical cord-derived mesenchymal stem cells (HUCMSCs), and this isolation was followed by the transfer of miR-140-3p. RA rat models were constructed by collagen II adjuvant and respectively treated with HUCMSCs-exo or HUCMSCs-exo carrying miR-140-3p mimic/inhibitor, and expression of miR-140-3p and serum- and glucocorticoid-inducible kinase 1 (SGK1) was assessed. Then, RA score and inflammation scoring, fibrosis degree and apoptosis, serum inflammatory response and oxidative stress in joint tissues were determined. The RA synovial fibroblasts (RASFs) were extracted from rats and identified. Conducted with relative treatment, the migration, proliferation and apoptosis in RASFs were determined.ResultsMiR-140-3p was decreased while SGK1 was increased in RA rats. HUCMSCs-exo or upregulated exosomal miR-140-3p improved pathological changes and suppressed inflammation, oxidative stress and fibrosis in RA rats, and also constrained and RASF growth. Overexpression of SGK1 reversed the inhibition of RASF growth caused by overexpression of miR-140-3p.ConclusionUpregulated exosomal miR-140-3p attenuated joint injury of RA rats by silencing SGK1. This research provided further understanding of the role of exosomal miR-140-3p in RA development.

Quercetin mitigates rheumatoid arthritis by inhibiting adenosine deaminase in rats

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease characterized by synovial proliferation and bone destruction. Adenosine deaminase (ADA) is a key inflammatory enzyme that increases joint stiffness and pain in RA. In this study, we evaluated the in-silico, and in vivo inhibitory effect of quercetin isolated from Egyptian Fenugreek on ADA enzyme activity. We also determined the combinatorial effect of quercetin on methotrexate mediated anti-inflammatory efficacy and toxicity. In-silico molecular docking was conducted and confirmed in an in vivo RA rat model. The results showed that the inhibition constant of quercetin on joint ADA by docking and in-vitro was 61.9 and 55.5 mM, respectively. Therefore, quercetin exhibits anti-inflammatory effect in a rat RA model as evidenced by reducing the specific activity of ADA in joint tissues, lower jaw volume, enhance body weight, downregulate ADA gene expression, reduce levels of RA cytokines interleukin-1β, interleukin-6, tumor necrosis factor-α, also, rheumatoid factor, C-reactive protein, and anti-cyclic citrullinated peptide RA biomarker levels. These findings demonstrate that the purified quercetin has a promising anti-inflammatory effect against RA disease through its inhibitory effects on the ADA enzyme. Furthermore, isolated quercetin improved the anti-inflammatory efficacy of methotrexate, reduced its toxic effects by increasing antioxidant enzymes and reducing oxidative stress.

Effect of moxibustion on autophagy and the inflammatory response of synovial cells in rheumatoid arthritis model rat.

To investigate the effect of moxibustion on synovitis and the autophagy of synoviocytes in rheumatoid arthritis (RA). Forty Sprague-Dawley rats were randomly divided into a normal group, model group, moxibustion group, cigarette moxibustion group, and medicine group, with eight rats included in each group. The RA model was established by subcutaneous injection of complete Freund's adjuvant into the left posterior toe. Rats in the model group were not interfered with. In the moxibustion group, rats were treated by moxibustion, where a 1-cm diameter moxa stick was applied at the left Zusanli (ST 36) point. The distance of the moxa stick to the skin was 2 cm and moxibustion was completed for 20 min daily for 15 d total. In the cigarette moxibustion group, the moxa stick was replaced by a common cigarette. In the medicine group, rats were treated with a tripterygium glycoside suspension (8 mg/kg) once a day for 15 d total. In each group, the left hind limb toe volume was measured with a toe volume meter; the synovial cells were observed by hematoxylin and eosin staining; the interleukin (IL)-4, IL-6, IL-10, IL-1β, IL-23, IL-17, and tumor necrosis factor (TNF)-α levels in serum were measured by enzyme-linked immunosorbent assay; the erythrocyte sedimentation rate (ESR) were detected by Westergren sedimentation rate testing; the C-reactive protein (CRP) and rheumatoid factor (RF) levels in serum were detected by rate nephelometry; the expression levels of ULK1, autophagy-associated protein (Atg)3, Atg5, and Atg12 messenger RNA (mRNA) in synovium were detected by real time-quantitative polymerase chain reaction (RT-qPCR); and the protein expression levels of phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt), mammalian target of rapamycin (mTOR), LC3-II, beclin-1, phosphorylated-PI3K (p-PI3K), p-Akt, p-mTOR in synovium were detected by Western blotting. Among the RA model rats, joint swelling, an inflammatory reaction, and the proliferation of synovial tissue were obvious and the signal of the PI3K/Akt/mTOR pathway was active, while autophagy was inhibited. Moxibustion at Zusanli (ST36) or intragastric administration of Tripterygium wilfordii glycosides could alleviate the inflammatory reaction of RA rats; relieve the swelling of the toes; downregulate the levels of ESR, CRF, RF; lower the levels of IL-6, IL-1β, TNF-α, and IL-17; and increase the IL-4 and IL-10. At the same time, the mRNA expression levels of ULK1, Atg3, Atg5, and Atg12 and those of LC3-Ⅱ and beclin-1 were increased, while the PI3K, Akt, mTOR, p-PI3K, p-Akt, p-mTOR were decreased. Cigarette moxibustion did not significantly reduce the swelling of the toe joint in RA rats, and was not as good as that of moxibustion or Tripterygium wilfordii polyglycosides in the effects of inflammation relief and the influences of the levels of ESR, CRF, RF. While cigarette moxibustion has a weak effect to affect the expression of corresponding molecules in autophages and the expression level of the autophagy biomaker in synovial tissue. Moxibustion and tripterygium glycosides can significantly reduce the joint swelling, relieve synovitis and synovial hyperplasia, and inhibit the PI3K/Akt/mTOR signaling pathway to increase autophagy in a manner superior to cigarette moxibustion. Moxibustion can limit the proliferation of synoviocytes in RA rats by inhibiting the PI3K/Akt/mTOR signaling pathway, promoting autophagy, effectively reducing synovitis, and alleviating joint swelling.

The method of Yiqi Yangyin Tongluo can attenuate the pyroptosis of rheumatoid arthritis chondrocytes through the ASIC1a/NLRP3 signaling pathway.

BackgroundBased on the ASIC1a/NLRP3 signaling pathway, we explored the specific molecular mechanism of the pyroptosis of rheumatoid arthritis (RA) chondrocytes by the method of nourishing qi, nourishing yin, and dredging collaterals to provide new ideas for the treatment of this disease.MethodsA total of 50 rats were divided into a normal group, model group, methotrexate group, Yiqi Yangyin Tongluo group, and combined group. Except for the normal control group, the other groups used Freund's complete adjuvant (FCA) to make RA rat model. The arthritis index and ankle joint swelling of rats in each group were recorded. HE staining and ELISA were used to assess the pathology of the ankle joint of each group of rats and the content of IL-1β and IL-18 in rat serum. Furthermore, immunofluorescence and qPCR methods were used to detect the protein and mRNA expression levels of NLRP3, caspase 1, ACS, and ASIC1a in the cartilage tissue of each group of rats.ResultsCompared with the normal group, the right hind foot joint of the model group was significantly swollen, the levels of IL-18 and IL-1β in the serum of rats increased significantly, and the mRNA and protein levels of NLRP3, caspase 1, ACS, and ASIC1a in the chondrocytes also increased significantly. Compared with the model group, the degree of ankle joint swelling and IL-18 and IL-1β content in rat serum in each medication group was significantly reduced, and the combined group showed the greatest reduction compared with the other groups. After 8 weeks of treatment, compared with the model group, the mRNA and protein levels of NLRP3, caspase 1, ACS, and ASIC1a in the chondrocytes of each medication group were down-regulated. HE staining found that there were large numbers of infiltrating inflammatory cells and pannus in the joint tissue of the model group, while only a small amount of inflammatory cell infiltration and pannus was seen in the joint tissue of the rats in each treatment group.ConclusionsThe method of Yiqi Yangyin Tongluo can attenuate the pyroptosis of RA chondrocytes through the ASIC1a/NLRP3 signaling pathway.

Development of a hyperbranched polymer-based methotrexate nanomedicine for rheumatoid arthritis

Methotrexate (MTX) is an effective disease modifying anti-rheumatic drug, but can cause significant hepatotoxicity and liver failure in some individuals. The goal of this work was to develop a MTX-conjugated hyperbranched polymeric nanoparticle based on oligo(ethylene glycol) methyl ether methacrylate (OEGMA) and examine its ability to selectively deliver MTX to rheumatic joints while sparing the liver. MTX was conjugated to the hyperbranched polymer via a matrix metalloproteinase-13 cleavable peptide linker. Two populations of nanoparticles were produced, with sizes averaging 20 and 200nm. Tri-peptide (FFK)-modified MTX was liberated in the presence of matrix metalloproteinase 13 (MMP-13)and showed 100 to 1000-fold lower antiproliferative capacity in monocytic THP-1 cells compared to unmodified MTX, depending on whether the gamma-carboxylate of MTX was functionalized with O-tert-butyl. Nanoparticles showed prolonged plasma exposure after intravenous injection with a terminal half-life of approximately 1 day, but incomplete (50%) absorption after subcutaneous administration. Nanoparticles selectively accumulated in inflamed joints in a rat model of rheumatoid arthritis and showed less than 5% biodistribution in the liver after 5 days. MTX-OtBu nanoparticles also showed no hepatocellular toxicity at 500 μM MTX equivalents. This work provides support for the further development of OEGMA-based hyperbranched polymers as MTX drug delivery systems for rheumatoid arthritis. Statement of significanceNanomedicines containing covalently conjugated methotrexate offer the potential for selective accumulation of the potent hepatotoxic drug in rheumatic joints and limited liver exposure. One limitation of the high surface presentation of methotrexate on a nanoparticle surface, however, is the potential for enhanced liver uptake. We developed several OEGMA-based hyperbranched polymers containing alpha-carboxyl modified and unmodified methotrexate conjugated via an MMP-13 cleavable hexapeptide linker. The modified methotrexate polymer showed promising in vitro and in vivo behavior warranting further development and optimization as an anti-rheumatic nanomedicine. This work presents a new avenue for further research into the development of hyperbranched polymers for rheumatoid arthritis and suggests interesting approaches that may overcome some limitations associated with the translation of anti-rheumatic nanomedicines into patients.

Cell-free DNA depletion via cell-penetrating poly(disulfide)s for rheumatoid arthritis therapy

Cell-free DNA (cfDNA)-induced inflammation is linked to various autoimmune diseases, though cfDNA scavenging for cationic polymers has been regarded as an efficient therapeutic pathway. However, most existing cfDNA scavengers have significant cytotoxicity and weakly binds to cfDNA. Here, an advanced cfDNA scavenging strategy via assembly of cfDNA is reported for rheumatoid arthritis (RA) therapy. In this study, we developed a pH-responsive calcium carbonate nanoplatform loaded with low-toxicity guanidinium-containing cell-penetrating poly(disulfide)s (CPDs, LA). The LA could strongly adhere to nucleic acid (NA) and further self-assemble into NA nanospheres. Importantly, the NA nanospheres could be directly delivered into the cell through thiol-mediated uptake, which avoided the activation of the endosomal toll-like receptors (TLRs), thereby inhibited CpG-activated inflammation. As a result, LA@CaCO3 effectively decreased the cfDNA level and alleviated the joint swelling and bone erosion on a collagen-induced arthritis (CIA) rat model of RA. Accordingly, the study proposes an advanced approach to deplete NA for autoimmune disease treatment.

Curcumin-Pretreated Adipose-Derived Stem Cells Enhance the Neuroprotective Ability to Repair Rheumatoid Arthritis-Induced Damage in the Rat Brain.

Neurodegenerative diseases have become increasingly prevalent in the aged population. Rheumatoid arthritis (RA) is an autoimmune disease that causes systemic inflammation, damaging the neurons. However, only a few treatment options can reduce RA-induced neurodegeneration. This study aimed to evaluate whether adipose-derived stem cells (ADSCs) pretreated with curcumin could ameliorate RA-induced neurodegenerative illness in an RA rat model. Wistar rats were randomly classified into the following four groups: control, RA, RA + ADSC (1 × 106 cells per rat), and RA + curcumin-pretreated ADSC (1 × 106 cells per rat). After treatment for two months, the effects were specifically evaluated in the brains collected from the rats. Our results demonstrated that the transplantation of curcumin-pretreated ADSCs substantially reduced inflammation and apoptosis in the cortices of RA rats compared to those of other groups. Thus, the combination of ADSCs and curcumin exerts a synergistic effect in enhancing neuronal protection in RA rats. In the future, this combination therapeutic strategy can potentially be used as a novel treatment method to reduce RA-induced neurodegenerative disorders.

IL-38 and IL-36 Target Autophagy for Regulating Synoviocyte Proliferation, Migration, and Invasion in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease leading to severe joint damage and disability. Fibroblast-like synoviocytes (FLSs) mostly contribute to the joint inflammation and destruction in RA through distinct mechanisms. However, little is known about newly discovered interleukin- (IL-) 36 and IL-38 involving in the pathology of RA. Here, we assessed the effect of IL-36 and IL-38 on RA-FLS function using IL-36 and IL-38 overexpression plasmids. We found that IL-36 inhibited synoviocytes proliferation while IL-38 showed an opposite influence. Furthermore, IL-36 and IL-38 significantly sequestered or accelerated RA-FLS migration and invasion capacity, respectively. Mechanically, IL-36 and IL-38 targeted autophagy for RA-FLS modulation. Using autophagy inhibitor 3-MA and inducer compound rapamycin, we found that autophagy negatively regulated the survival, migration, and invasion of synovial cells. Based on these results, IL-38 in combination with autophagy inhibitor 3-MA treatment demonstrated the strongest blockage of the above three activities of RA-FLS, and IL-38 overexpression reversed rapamycin-inhibited cell proliferation, migration, and invasion. Moreover, injection of IL-36 can improve the symptoms of RA in a rat model of RA. Taken together, we conclude that IL-38 and IL-36 target autophagy for regulating synoviocyte proliferation, migration, and invasion in RA.

Intestinal metabolism and absorption mechanism of multi-components in Gaultheria leucocarpa var. yunnanensis - An assessment using in situ and in vitro models, comparing gut segments in pathological with physiological conditions

Ethnopharmacological relevanceDianbaizhu (Gaultheria leucocarpa var. yunnanensis) as a Chinese folk medicine exerts significant treatment effects on rheumatoid arthritis (RA) with a long historical time. Our previous reports showed that the anti-rheumatic arthritis fraction (ARF) extracted and enriched from Dianbaizhu possessed good druggability, which was better than its single active ingredients. However, the intestinal transport characteristics and mechanism of ARF have not been elucidated to date. Aim of the studyIn order to illustrate the role of active ingredients of ARF in alleviating RA and promoting the development of dosage forms, the intestinal metabolism, absorption properties and mechanism of ARF in vitro and in situ models were investigated. Materials and methodsFirstly, after incubating with 4 intestinal segments (duodenum, jejunum, ileum, and colon), 7 key components in ARF, including MATG-B, (+)-catechin, MSTG-A, Gaultherin, chlorogenic acid, quercetin, and kaempferol were quantitatively analyzed by a high-performance liquid chromatography (HPLC). Secondly, combining the physiological and pathological rats, the in situ single-pass intestinal perfusion and in vitro everted gut sacs of rats were performed to investigate the absorption features and transport mechanisms of ARF using HPLC and HPLC-Q-TOF-MS/MS. Subsequently, in situ studies were employed to determine the effect of P-glycoprotein (P-gp) inhibitor (verapamil) on the transport characteristics of ARF in RA model rats. ResultsComparing the absorption parameters of ARF incubated in different intestinal segments, data showed that the absorption of ARF in the small intestine was significantly stronger than that of the colon (P < 0.01). The number of characterized prototype components was subjected to the incubation time, drug concentration and rat body condition, but not the intestinal segments. There were no significant differences in the number of metabolites among different intestinal segments, administration concentrations and incubation time. The best small intestinal absorption site of ARF was duodenum and ileum in normal and model rats, respectively. The Peff values of 7 index compounds were all higher than 0.2 × 10−4cm/s, and the Fa values of 7 index compounds were all greater than 20% in the in situ perfusion investigation. The results showed that MSTG-B, MSTG-A and Gaultherin were likely to be substrates of P-gp as verapamil significantly enhanced their Peff and Ka values, while other ingredients were not P-gp substrates. ConclusionsThe intestinal membrane permeability of ARF was good. Its intestinal absorption mechanisms mainly involved active transportation processes and passive diffusion. Besides, this report provided data support and basis for clinical development, bioavailability improvement and formulation design.