Micro-computed tomography evaluation and pathological analyses of female rats with collagen-induced arthritis

Injection of kaolin/carrageenan in the rat knee joint induces progressive experimental knee osteoarthritis

ABSTRACT

Osteoarthritis (OA), the most common joint disorder worldwide, is characterized by progressive degeneration of articular and periarticular structures, leading to physical and emotional impairments that greatly affect the quality of life of patients. Unfortunately, no therapy has been able to halt the progression of the disease. Owing to the complexity of OA, most animal models are only able to mimic a specific stage or feature of the human disorder. In this work, we demonstrate the intraarticular injection of kaolin or carrageenan leads to the progressive degeneration of the rat's knee joint, accompanied by mechanical hyperalgesia and allodynia, gait impairments (reduced contact area of the affected limb), and radiological and histopathological findings concomitant with the development of human grade 4 OA. In addition, animals also display emotional impairments 4 weeks after induction, namely, anxious and depressive-like behaviour, important and common comorbidities of human OA patients. Overall, prolonging kaolin or carrageenan-induced monoarthritis mimics several important physical and psychological features of human OA in both male and female rodents and could be further applied in long-term studies of OA-associated chronic pain.

A highly efficient protein corona-based proteomic analysis strategy for the discovery of pharmacodynamic biomarkers

The composition of serum is extremely complex, which complicates the discovery of new pharmacodynamic biomarkers via serum proteome for disease prediction and diagnosis. Recently, nanoparticles have been reported to efficiently reduce the proportion of high-abundance proteins and enrich low-abundance proteins in serum. Here, we synthesized a silica-coated iron oxide nanoparticle and developed a highly efficient and reproducible protein corona (PC)-based proteomic analysis strategy to improve the range of serum proteomic analysis. We identified 1,070 proteins with a median coefficient of variation of 12.56% using PC-based proteomic analysis, which was twice the number of proteins identified by direct digestion. There were also more biological processes enriched with these proteins. We applied this strategy to identify more pharmacodynamic biomarkers on collagen-induced arthritis (CIA) rat model treated with methotrexate (MTX). The bioinformatic results indicated that 485 differentially expressed proteins (DEPs) were found in CIA rats, of which 323 DEPs recovered to near normal levels after treatment with MTX. This strategy can not only help enhance our understanding of the mechanisms of disease and drug action through serum proteomics studies, but also provide more pharmacodynamic biomarkers for disease prediction, diagnosis, and treatment.

Anti-arthritic effect of chicken embryo tissue hydrolyzate against adjuvant arthritis in rats (X-ray microtomographic and histopathological analysis)

Finding new, safe strategies to prevent and control rheumatoid arthritis is an urgent task. Bioactive peptides and peptide-rich protein hydrolyzate represent a new trend in the development of functional foods and nutraceuticals. The resulting tissue hydrolyzate of the chicken embryo (CETH) has been evaluated for acute toxicity and tested against chronic arthritis induced by Freund's full adjuvant (modified Mycobacterium butyricum) in rats. The antiarthritic effect of CETH was studied on the 28th day of the experiment after 2 weeks of oral administration of CETH at doses of 60 and 120 mg/kg body weight. Arthritis was evaluated on the last day of the experiment on the injected animal paw using X-ray computerized microtomography and histopathology analysis methods. The CETH effect was compared with the non-steroidal anti-inflammatory drug diclofenac sodium (5 mg/kg). Oral administration of CETH was accompanied by effective dose-dependent correction of morphological changes caused by the adjuvant injection. CETH had relatively high recovery effects in terms of parameters for reducing inflammation, inhibition of osteolysis, reduction in the inflammatory reaction of periarticular tissues, and cartilage degeneration. This study presents for the first time that CETH may be a powerful potential nutraceutical agent or bioactive component in the treatment of rheumatoid arthritis.

Standardized Xylocarpus moluccensis fruit fraction mitigates collagen-induced arthritis in mice by regulating immune response

OBJECTIVE

This study was undertaken to evaluate the effect of Xylocarpus moluccensis fruit fraction (F018) on the pathogenesis of collagen-induced arthritis in mice.

METHODS

Arthritis was induced by intradermal injection of collagen (2 mg/ml) with complete Freund's adjuvant in DBA/1J mice. F018 was administered orally at 1, 3 and 10 mg/kg for 20 days. Disease progression and mechanism were assessed by micro-CT analysis, RT-PCR, flow cytometry assay, myeloperoxidase (MPO) and MTT assay.

RESULTS

F018 at 3 and 10 mg/kg significantly reduced paw thickness, clinical score, mononuclear cell infiltration and collagen layer depletion in the knee section of collagen-induced arthritis (CIA) mice when compared with collagen-induced arthritis mice alone. Furthermore, F018 treatment in collagen-induced arthritis mice significantly recovered bone volume and trabecular number and decreased the trabecular space by modulating RANKL and OPG mRNA expression in the synovial tissue. F018 treatment in collagen-induced arthritis mice significantly attenuated spleen index, lymphocyte proliferation and paw myeloperoxidase (MPO) activity, pro-inflammatory cytokine TNFα, IL1β, and IL6 mRNA expression and enhanced IL10 mRNA expression in paw tissue. Furthermore, F018 treatment in collagen-induced arthritis mice significantly reduced splenic dendritic cell maturation and Th17 cells. In culture, F018 significantly decreased collagen-induced arthritis-FLS proliferation and promoted apoptosis.

CONCLUSION

F018 may serve as a potential curative agent for arthritis.

Ultrasound-triggered perfluorocarbon-derived nanobombs for targeted therapies of rheumatoid arthritis

The targeted US-triggered PFC-based “nanobombs” with US used to treat the RA in this work would offer a new treatment strategy and have a great potential for the application in the areas of theranostic agent and nanomedicine treatment.

A Truncated IL-17RC Peptide Ameliorates Synovitis and Bone Destruction of Arthritic Mice

Peptide-based therapy, such as modified peptides, has attracted increased attention. IL-17 is a promising therapeutic target for autoimmune diseases, and levels of circulating bioactive IL-17 are associated with rheumatoid arthritis severity. In this study, a modified truncated IL-17RC is generated to ameliorate inflammation and bone destruction in arthritis. The truncated IL-17RC binds to both IL-17A and IL-17F with higher binding capacity compared to nonmodified IL-17RC. In addition, the truncated IL-17RC reduces the secretion of inflammatory and osteoclastogenic factors induced by IL-17A/F in vitro. Moreover, the administration of truncated IL-17RC dramatically improves symptoms of inflammation and inhibited bone destruction in collagen-induced arthritis mice. Collectively, these data demonstrate that modified truncated IL-17RC peptide may be a more effective treatment strategy in the simultaneous inhibition of both IL-17A and IL-17F signaling, whereas the existing agents neutralize IL-17A or IL-17F alone. These suggest that the truncated IL-17RC may be a potential candidate in the treatment of inflammatory associated bone diseases.