Dose- and stage-dependent toxic effects of prenatal prednisone exposure on fetal articular cartilage development

Prednisone is frequently used to treat rheumatoid diseases in pregnant women because of its high degree of safety. Whether prenatal prednisone exposure (PPE) negatively impacts fetal articular cartilage development is unclear. In this study, we simulated a clinical prednisone treatment regimen to examine the effects of different timings and doses of PPE on cartilage development in female and male fetal mice. Prednisone doses (0.25, 0.5, and 1 mg/kg/d) was administered to Kunming mice at different gestational stages (0-9 gestational days, GD0-9), mid-late gestation (GD10-18), or during the entire gestation (GD0-18) by oral gavage. The amount of matrix aggrecan (ACAN) and collagen type II a1(COL2a1), and expression of transforming growth factor β1 (TGFβ1) signaling pathway also demonstrated that the chondrocyte count and ACAN and COL2a1 expression reduced in fetal mice with early and mid-late PPE, with the reduction being more significant in the mice with early PPE than that in those with PPE at other stages. Prenatal exposure to different prednisone doses prevented the reduction of TGFβ signaling pathway-related genes [TGFβR1, SMAD family member 3 (Smad3), SRY-box9 (SOX9)] as well as ACAN and COL2a1 mRNA expression levels in fetal mouse cartilage, with the most significant decrease after 1 mg/kg·d PPE. In conclusion, PPE can inhibit/restrain fetal cartilage development, with the greatest effect at higher clinical dose (1 mg/kg·d) and early stage of pregnancy (GD0-9), and the mechanism may be related to TGFβ signaling pathway inhibition. The result of this study provide a theoretical and experimental foundation for the rational clinical use of prednisone.

Protective effect of lupeol on arthritis induced by type II collagen via the suppression of P13K/AKT signaling pathway in Sprague dawley rats

To explore the therapeutic value of lupeol on collagen-induced arthritis (CIA) in rats, a rheumatoid arthritis model. Lupeol is well known pentacyclic triterpene found in various plant sources, which possess anti-inflammatory and antioxidant actions. The current study was assessed the anti-arthritic potential of lupeol and its molecular mechanisms as compared with indomethacin (Indo) in collagen-induced arthritis CIA rats. The rats were randomly alienated into five groups: Control, CIA alone, CIA + lupeol (10 mg/kg bw), CIA + Indomethacin (3 mg/kg bw), and lupeol (10 mg/kg bw) alone. The paw volume, biochemical, hematological parameters, inflammatory enzymes, and cytokines were measured. As well protein expression of apoptotic proteins, and histopathological of ankle joint were examined. Inflammatory markers, cytokines, histological changes, paw volume, and inflammation were intensely reduced and enhanced apoptosis by lupeol. Alterations in hematological parameters, rheumatoid factor, C-reactive protein, and ceruloplasmin in arthritis were reverted by lupeol. Protein expressions of Bcl-2, and P13K/Akt signaling were declined, whereas the Bax, caspssae-3, and caspase-9 were elevated. These results highlighted that lupeol suppresses P13K/Akt signaling and has a promising anti-arthritic potential for collagen-induced rheumatic arthritis treatment. Hence lupeol would be suggested as an alternative natural source with potent anti-inflammatory and apoptotic actions for chronic inflammatory disorders.

Expression of mBD4, mBD3 and CRAMP during type II collagen-induced arthritis/CIA and their association with inflammation and bone-remodeling markers

The aim of this study was to analyze the expression of mBD4, mBD3 and CRAMP in joint of mice with type II collagen-induced arthritis/CIA and to explore its possible association with IL-10, IL-4, IFN-γ, IL-17, MMP3, RANK/RANKL/OPG and histological parameters.

METHODS

CIA was induced in 44 DBA/1 J mice. The joints from mice were classified into the onset, peak and remission phase of CIA. Histological sections were stained with hematoxylin-eosin and safranin O. The expression of CRAMP, mBD-3, mBD-4, and MMP-3 was evaluated using reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. The expression of IL-10, IL-4, IFN-γ, IL-17, RANK/RANKL/OPG was analyzed by RT-PCR.

RESULTS

We observed that inflammation and immunostained cells for CRAMP increased in the peak and remission phases compared to the control group. In addition, increments in relative expressions of CRAMP were detected for the remission phase and in IL-4 and IL-17 in the peak phase compared to the control and onset phase. In addition, an increase in IL-10 in a peak phase compared to the control, as well as the relative expression of IFN-γ in remission phase was higher than in the onset phase. This was accompanied by an increase in cartilage damage in the peak phase compared to the control. Cells immunostained to MMP3 increased in the peak phase compared to the onset and control group, and relative expression of MMP3 was detected in the peak phase compared to the onset, remission, and control group. We observed that the relative expression of RANK and RANKL in the peak phase was higher than in control and onset phase. Finally, the relative expression of OPG in the peak phase compared to the onset, remission, and control group was detected. Regarding CRAMP behavior in the different phases studied, it was positively correlated with IL-4 and RANK, and showed a negative correlation with IFN-γ, IL-17, IL-10, RANKL, OPG and RANKL/OPG ratio in the control group. Also was positively correlated with IFN-γ, IL-17, IL-4, IL-10, as well as with RANK, RANKL, and OPG in the onset and peak phases of the CIA. In the peak phase, CRAMP showed a positive association with MMP3, and we observed a direct correlation between CRAMP and IFN-γ and RANKL/OPG ratio in remission phase. mBD3 correlates positively with IFN-γ, IL-17, IL-10, RANKL, OPG and RANKL/OPG ratio, and showed a negative correlation with CRAMP, MMP3, and RANK in the control group. Also, it was directly associated with IFN-γ, IL-17, IL-4, IL-10 and RANKL in the onset phase while it was inversely associated with CRAMP, MMP-3, RANK, RANKL, and OPG in the peak phase. Finally, mBD3 was inversely correlated with MMP3 in the remission phase and was directly associated with CRAMP, IFN-γ and RANKL/OPG ratio in this phase. mBD4 was directly associated with CRAMP, IFN-γ, IL-17, IL-4, IL-10, RANKL / OPG in the onset phase, and with CRAMP, IFN-γ, IL-17, IL-4, IL-10, MMP3, RANK, RANKL and OPG in the peak phase. Finally, mBD4 was positively associated with mBD3, IFN-γ, IL-17, IL-10, RANK, RANKL OPG and RANKL/OPG in the CIA remission phase.

CONCLUSIONS

Our results demonstrate that CRAMP plays an important role in CIA progress and suggest that its abundance is associated with local pro- and anti-inflammatory status. This makes us propose CRAMP as a possible contributor of bone reconstruction in the last stage of CIA.

Associations of inflammatory markers with impaired left ventricular diastolic and systolic function in collagen-induced arthritis

Background

High-grade inflammation may play a pivotal role in the pathogenesis of left ventricular (LV) dysfunction. Evidence to support a role of systemic inflammation in mediating impaired LV function in experimental models of rheumatoid arthritis (RA) remains limited. The aim of the present study was to determine the effects of high-grade systemic inflammation on LV diastolic and systolic function in collagen-induced arthritis (CIA).

Methods

To induce CIA, bovine type-II collagen emulsified in incomplete Freund’s adjuvant was injected at the base of the tail into 21 three-month old Sprague Dawley rats. Nine-weeks after the first immunisation, LV function was assessed by pulsed Doppler, tissue Doppler imaging and Speckle tracking echocardiography. Cardiac collagen content was determined by picrosirius red staining; circulating inflammatory markers were measured using ELISA.

Results

Compared to controls (n = 12), CIA rats had reduced myocardial relaxation as indexed by lateral e’ (early diastolic mitral annular velocity) and e’/a’ (early-to-late diastolic mitral annular velocity) and increased filling pressures as indexed by E/e’. No differences in ejection fraction and LV endocardial fractional shortening between the groups were recorded. LV global radial and circumferential strain and strain rate were reduced in CIA rats compared to controls. Higher concentrations of circulating inflammatory markers were associated with reduced lateral e’, e’/a’, radial and circumferential strain and strain rate. Greater collagen content was associated with increased concentrations of circulating inflammatory markers and E/e’.

Conclusion

High-grade inflammation is associated with impaired LV diastolic function and greater myocardial deformation independent of haemodynamic load in CIA rats.

Cinnamaldehyde and eugenol attenuates collagen induced arthritis via reduction of free radicals and pro-inflammatory cytokines

BACKGROUND

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease which leads to bone and cartilage erosion. Oxidative stress and pro-inflammatory cytokines plays crucial role in the pathophysiology of RA. Cinnamaldehyde and eugenol have a long history of medical use in various inflammatory disorders.

PURPOSE

The drugs available for the treatment of RA are associated with various side effects. The present study was conducted to evaluate the anti-arthritic effects of cinnamaldehyde and eugenol in rat model of arthritis.

METHODS

Type II collagen was intradermally injected to rats for the induction of arthritis. Cinnamaldehyde (10 and 20 mg/kg/day) and eugenol (10 and 20 mg/kg/day) were given orally for 15 days, starting from day 21 to 35. Dexamethasone treated rats served as positive control. Histological, radiological and scanning electron microscopic analysis were done to monitor the effect of compounds on collagen induced arthritis (CIA). Reactive oxygen species (ROS) formation, nitric oxide and antioxidant status were also determined. The markers of biomolecular oxidation (protein, lipid and DNA) and activities of enzymatic antioxidants (superoxide dismutase, glutathione peroxidase, catalase and glutathione reductase) were also evaluated in the joint homogenate and plasma of rats. For detecting inflammation, levels of TNF-α, IL-6 and IL-10 were monitored by ELISA.

RESULTS

Our results showed anti-oxidant and anti-inflammatory effects of cinnamaldehyde and eugenol in arthritic rats. Scanning electron microscopy, histopathological and radiological findings also confirmed the anti-arthritic effects of cinnamaldehyde and eugenol. Both the compounds were effective in bringing significant decrease in the levels of ROS, nitric oxide, markers of biomolecular oxidation and increase in enzymatic and non-enzymatic antioxidants. The levels of TNF-α, IL-6 and IL-10 were also ameliorated by cinnamaldehyde and eugenol treatment. Between the two phytochemicals used, eugenol was found to be more effective than cinnamaldehyde in reducing the severity of arthritis.

CONCLUSION

Cinnamaldehyde and eugenol were effective in ameliorating oxidative stress and inflammation in arthritic rats. These findings indicate that cinnamaldehdye and eugenol have a great potential to be used as an adjunct in the management of RA.

Anti-arthritic effect of pentosan polysulfate in rats with collagen-induced arthritis

Pentosan polysulfate (PPS) is currently under investigation as a potential disease-modifying antiarthritic agent. In the present study the effects of PPS on arthritic profiles based on clinical score, ankle size, histological changes, and activity of inflammatory mediators using collagen-induced arthritic rat are reported. Model of arthritis was developed in Sprague Dawley rats by intradermal injection of bovine type II collagen emulsified with incomplete Freund's adjuvant. The rats were randomly divided into four groups: normal control, arthritic control, arthritic rats treated with PPS (at dose level 20 μg/g) and arthritic rats treated with meloxicam (2 μg/g). The treatment was continued daily until the day 30. Arthritic biomarkers (cartilage oligomeric matrix protein and tartrate-resistant acid phosphatase 5b) in synovial fluid, expression of inflammatory mediators (interleukin-1β, and tumor necrosis factor-α) and osteoclast marker genes (cathepsin K, tartrate-resistant acid phosphatase) in synovial membrane were measured. Daily administration of PPS to the arthritic rats significantly decreased the severity of arthritis by effectively suppressing the symptoms of arthritis and improving the functional recovery based on clinical score and histopathological evidence. Intriguingly, identical downregulation pattern of arthritis profiles, biological markers as well as relative mRNA levels of osteoclast markers and cytokines were monitored in arthritic rats treated with PPS. In conclusion, PPS exerted protective effects against collagen-induced arthritis in rats. The results suggest that PPS acts as an anti-inflammatory and anti-arthritic agent in decreasing the arthritic effects in collagen-induced arthritic rats.

Intra-Articular Injections of Polyphenols Protect Articular Cartilage from Inflammation-Induced Degradation: Suggesting a Potential Role in Cartilage Therapeutics

Arthritic diseases, such as osteoarthritis and rheumatoid arthritis, inflict an enormous health care burden on society. Osteoarthritis, a degenerative joint disease with high prevalence among older people, and rheumatoid arthritis, an autoimmune inflammatory disease, both lead to irreversible structural and functional damage to articular cartilage. The aim of this study was to investigate the effect of polyphenols such as catechin, quercetin, epigallocatechin gallate, and tannic acid, on crosslinking type II collagen and the roles of these agents in managing in vivo articular cartilage degradation. The thermal, enzymatic, and physical stability of bovine articular cartilage explants following polyphenolic treatment were assessed for efficiency. Epigallocatechin gallate and tannic acid-treated explants showed >12 °C increase over native cartilage in thermal stability, thereby confirming cartilage crosslinking. Polyphenol-treated cartilage also showed a significant reduction in the percentage of collagen degradation and the release of glycosaminoglycans against collagenase digestion, indicating the increase physical integrity and resistance of polyphenol crosslinked cartilage to enzymatic digestion. To examine the in vivo cartilage protective effects, polyphenols were injected intra-articularly before (prophylactic) and after (therapeutic) the induction of collagen-induced arthritis in rats. The hind paw volume and histomorphological scoring was done for cartilage damage. The intra-articular injection of epigallocatechin gallate and tannic acid did not significantly influence the time of onset or the intensity of joint inflammation. However, histomorphological scoring of the articular cartilage showed a significant reduction in cartilage degradation in prophylactic- and therapeutic-groups, indicating that intra-articular injections of polyphenols bind to articular cartilage and making it resistant to degradation despite ongoing inflammation. These studies establish the value of intra-articular injections of polyphenol in stabilization of cartilage collagen against degradation and indicate the unique beneficial role of injectable polyphenols in protecting the cartilage in arthritic conditions.

Discovery of novel 2,5-dioxoimidazolidine-based P2X(7) receptor antagonists as constrained analogues of KN62

Novel 2,5-dioxoimidazolidine-based conformationally constrained analogues of KN62 (1) were developed as P2X7 receptor (P2X7R) antagonists using a rigidification strategy of the tyrosine backbone of 1. SAR analysis of the 2,5-dioxoimidazolidine scaffold indicated that piperidine substitution at the N3 position and no substitution at N1 position were preferable. Further optimization of the substituents at the piperidine nitrogen and the spacer around the skeleton resulted in several superior antagonists to 1, including 1-adamantanecarbonyl analogue 21i (IC50 = 23 nM in ethidium uptake assay; IC50 = 14 nM in IL-1β ELISA assay) and (3-CF3-4-Cl)benzoyl analogue (-)-21w (54 nM in ethidium uptake assay; 9 nM in IL-1β ELISA assay), which was more potent than the corresponding (+) isomer. Compound 21w displayed potent inhibitory activity in an ex vivo model of LTP-induced pain signaling in the spinal cord and significant anti-inflammatory activity in in vivo models of carrageenan-induced paw edema and type II collagen-induced joint arthritis.

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

ETHNOPHARMACOLOGICAL RELEVANCE

The hip of Rosa multiflora Thunb. (HRM) has been traditionally used as a dietary supplement and a herbal remedy for the treatment of various diseases, including inflammation, osteoarthritis, rheumatoid arthritis and chronic pain, in China. The current study was to evaluate the therapeutic efficacy of the petroleum ether extractive of HRM (PEE) on type II collagen-induced rheumatoid arthritis (CIA) in male Wistar rats. In addition, the anti-inflammatory mechanism(s) of PEE on type II CIA was explored.

MATERIALS AND METHODS

Rheumatoid arthritis (RA) was induced by intradermal injection of bovine type II collagen on Day 1 and Day 8. Starting from Day 13, normal rats were treated with vehicle (serving as the control group); the CIA rats were treated with vehicle (CIA group), dexamethasone (0.25mg/kg bw per day, p.o.) (a positive control), lei-gong-teng (LGT: 10mg/kg bw per day, p.o.) (a clinically used Chinese patent medicine in RA therapy) or PEE (12, 36 or 120mg/kg bw per day, p.o.) for 28 days.

RESULTS AND CONCLUSIONS

PEE (120mg/kg bw per day) efficiently attenuated the severity of arthritis in the CIA rats by reducing the mean arthritis severity scores and the fore/hind paw swelling as well as reduced histological changes by decreasing the cartilage surface erosion and cartilage proteoglan depletion. PEE׳s therapeutic effect in RA may involve the inhibition of pro-inflammatory cytokines, such as TNF-α, IL-1β and IL-6, in serum and/or the elevation of the activities of hepatic anti-oxidative enzymes including SOD, CAT and GSH-Px. However, the detailed anti-inflammatory mechanism, the main effective components and the interaction between different ingredients in PEE are still not clear and require more studies.

Anti-inflammatory effect of Sanshuibaihu decoction may be associated with nuclear factor-kappa B and p38 MAPK alpha in collagen-induced arthritis in rat

Sanshuibaihu decoction (SSBH) is an anti-arthritic Chinese herbal formula which has been used in the treatment of rheumatoid arthritis (RA) for many years. We herein aimed to confirm its anti-arthritic effect and explore the potential mechanism of action on collagen-induced arthritis (CIA) in rats. CIA was induced by immunizing 50 female Wistar rats with bovine type II collagen. 13 days following the immunization rats with CIA were treated with SSBH (50mg/kg), leflunomide (LEF) (10mg/kg) and physiological saline for 30 days, and rats without CIA were left untreated. After the treatment, paw edema was obviously improved in SSBH-treated rats, with the significant difference of arthritis score (F=6.032, P=0.006) observed between the three treated groups. In pathological observation, SSBH-treated rats showed a significant improvement of inflammatory infiltration, synovial hyperplasia, cartilage and bone destruction and joint fusion. After the treatment of SSBH, radiological score of knee (t=11.504, P=0.000) and ankle joints (t=9.250, P=0.000) was decreased significantly. In situ hybridization on joint tissue section indicated only slight synovial hyperblastosis and expression of NF-kappaB in SSBH-treated rats. Image analysis indicated a significant difference of means of integrated optical density (MIOD) (F=3.956, P=0.040) and means of stained area (MSA) (F=3.867, P=0.032) of NF-kappaB between the three treated groups. MIOD and MSA of SSBH-treated group were significantly lower vs control. Enzyme linked immunosorbent assay (ELISA) showed a significant difference (F=10.167, P=0.000) of the amount of p-p38 MAPKalpha in the three treated groups. The detected amount of p-p38 MAPKalpha in SSBH-treated group was significantly lower vs control. These results show SSBH has an inhibiting effect on CIA, which may be associated with NF-kappaB and p38 MAPKalpha.

R992C (p.R1192C) Substitution in collagen II alters the structure of mutant molecules and induces the unfolded protein response

We investigated the molecular bases of spondyloepiphyseal dysplasia (SED) associated with the R992C (p.R1192C) substitution in collagen II. At the protein level, we analyzed the structure and integrity of mutant molecules, and at the cellular level, we specifically studied the effects of the presence of the R992C collagen II on the biological processes taking place in host cells. Our studies demonstrated that mutant collagen II molecules were characterized by altered electrophoretic mobility, relatively low thermostability, the presence of atypical disulfide bonds, and slow rates of secretion into the extracellular space. Analyses of cellular responses to the presence of the mutant molecules showed that excessive accumulation of thermolabile collagen II was associated with the activation of an "unfolded protein response" and an increase in apoptosis of host cells. Collectively, these data suggest that molecular mechanisms of SED may be driven not only by structural changes in the architecture of extracellular collagenous matrices, but also by intracellular processes activated by the presence of mutant collagen II molecules.

Anti-inflammatory activity of superoxide dismutase obtained from Debaryomyces hansenii on type II collagen induced arthritis in rats

INTRODUCTION

Rheumatoid arthritis is an autoimmune inflammatory disease of unknown etiology, free radicals have been implicated in the genesis and perpetuation of damage in this pathology.

OBJECTIVE

To evaluate the anti-inflammatory effect of Cu,Zn-superoxide dismutase (SOD) obtained from two different sources (bovine erythrocytes, Be-SOD, and Debaryomyces hansenii, Dh-SOD) with Type II Collagen-induced Arthritis model in rats.

MATERIAL AND METHODS

Arthritis was induced by repeated injection of a porcine type II collagen-incomplete Freund adjuvant suspension on the back of Dark Augui (DA) rats. Arthritis was clinically evaluated throughout the study. Body weight was determined at three different times. Two different doses for each treatment (Be-SOD, Dh-SOD) were tested: 100 and 1,000 U/kg. At the end of the trial (day 28), histological analyses of the most inflamed ankle joint, as well as serum anti-collagen antibodies, were determined.

RESULTS

Both sources of SOD decreased, although to a different extent, the incidence and severity of the disease. Arthritis score was lower in all treatments, except for the low dose of Be-SOD. Groups receiving either source of SOD showed a significant weight increase compared to the placebo group. Histological damage was similar in all groups. Only the group that received the highest dose of Dh-SOD showed a significant lower antibody titer; nevertheless, no correlation appears to derive from arthritis score and antibody titer.

CONCLUSION

Our findings suggest that, although unable to counteract the arthritis syndrome, SOD may still be beneficial due to its anti-inflammatory activity. In the case of Dh-SOD, the best effect was observed at the highest dose tested.

Reduction of CD4 positive T cells and improvement of pathological changes of collagen-induced arthritis by FTY720

FTY720 belongs to a new class of immunosuppressants. Little is known about its influence on T cell subtypes and pathological changes in arthritis. Here we illustrated the effect of FTY720 on peripheral T cell subsets and joint damage of collagen-induced arthritis rats. Rats were administered FTY720 or prednisone daily from day 0 to day 28. Body weight, hind paw swelling and arthritis index were measured. Bone destruction was determined by micro-computed tomography and histopathology, and T cell subsets were analyzed by flow cytometry and immunohistochemistry. The results showed that FTY720 inhibited the development of arthritis. Radiological analysis revealed that FTY720 treated collagen-induced arthritic rats had much less joint damage in comparison to untreated collagen-induced arthritic rats. Histological study showed that collagen-induced arthritic rats suffered from inflammatory cell infiltration and synovial hyperplasia in their joints, and FTY720 treatment clearly reduced these pathological changes. Immunohistochemical analysis showed that FTY720 treatment significantly decreased the number of CD4(+) T cells in the synovium of collagen-induced arthritic rats. Collagen-induced arthritic rats appeared to have more CD4(+), but not CD8(+) T cells in their peripheral blood than normal control rats. Following FTY720 treatment, peripheral blood CD3(+) and CD4(+) T cells in collagen-induced arthritic rats were significantly decreased. In conclusion, FTY720 is an effective compound in the treatment of collagen-induced arthritic rats and in reducing CD4(+) T cells in collagen-induced arthritic rats.

Effect of glycosaminoglycans on matrix metalloproteinases in type II collagen-induced experimental arthritis

Matrix metalloproteinases (MMPs) are a family of neutral proteinases that are involved in tissue remodeling by mediating degradation of extracellular matrix components in both physiology and pathology. As MMPs appear to play a key role in the degradation of cartilage matrix in the progression of arthritic disease, MMPs are considered as potential therapeutic targets. The effect of chondroitin sulfate A (CSA) on MMPs in type II collagen-induced experimental arthritis was studied. The anti-arthritic effect of CSA was evidenced by a decrease in marker activities like lysosomal beta-hexosaminidase and beta-glucuronidase. Arthritic animals showed significantly higher activity of MMP2 and MMP9 and increased levels of other MMPs, including MMP3 and MT-1 MMP in cartilage and serum. Treatment with CSA significantly decreased the activity of MMPs, particularly MMP9 in serum and synovial effusate and cartilage. The effect of CSA was further studied by fragmenting CSA into low-molecular-weight oligosaccharides. The oligosaccharide-treated animals showed considerably lower MMP activity (particularly MMP9) compared with arthritic controls. The CSA (and the oligosaccharides derived from it) not only reduced the activity of MMPs but also decreased the protein level expression of MMPs, indicating that the production of MMPs is affected. These results indicate that the antiarthritic effect of CSA involves down-regulation of MMPs, which are critically involved in the progression of arthritic disease.

CD4+CD25+ T cell-dependent inhibition of autoimmunity in transgenic mice overexpressing human Bcl-2 in T lymphocytes

Regulation of lymphocyte survival is essential for the maintenance of lymphoid homeostasis preventing the development of autoimmune diseases. Recently, we described a systemic lupus erythematosus associated with an IgA nephropathy in autoimmune-prone (NZW x C57BL/6)F(1) overexpressing human Bcl-2 (hBcl-2) in B cells (transgenic (Tg) 1). In the present study, we analyze in detail a second line of hBcl-2 Tg mice overexpressing the transgene in all B cells and in a fraction of CD4(+) and CD8(+) T cells (Tg2). We demonstrate here that the overexpression of hBcl-2 in T cells observed in Tg2 mice is associated with a resistance to the development of lupus disease and collagen type II-induced arthritis in both (NZW x C57BL/6)F(1) and (DBA/1 x C57BL/6)F(1) Tg2 mice, respectively. The disease-protective effect observed in autoimmune-prone Tg2 mice is accompanied by an increase of peripheral CD4(+)CD25(+) hBcl-2(+) regulatory T cells (T(regs)), expressing glucocorticoid-induced TNFR, CTLA-4, and FoxP3. Furthermore, the in vivo depletion of CD4(+)CD25(+) T(regs) in (DBA/1 x C57BL/6)F(1) Tg2 mice promotes the development of a severe collagen type II-induced arthritis. Taken together, our results indicate that the overexpression of hBcl-2 in CD4(+) T cells alters the homeostatic mechanisms controlling the number of CD4(+)CD25(+) T(regs) resulting in the inhibition of autoimmune diseases.

Collagen-induced arthritis in mice: a major role for tumor necrosis factor-alpha

Collagen-induced arthritis is the most widely used animal model for the evaluation of novel therapeutic strategies for rheumatoid arthritis. The disease is induced by immunization of genetically susceptible strains of mice or rats with type II collagen in adjuvant. Susceptibility to collagen-induced arthritis is associated with major histocompatibility complex (MHC) class II genes, although non-MHC genes also play a role. Both B- and T-lymphocytes are important in the pathogenesis of collagen-induced arthritis, with the peak of the T-cell response occurring around the time of disease onset. Histopathological assessment of the joints of animals with collagen-induced arthritis reveal a proliferative synovitis with infiltration of polymorphonuclear and mononuclear cells, the formation of an erosive pannus, cartilage degradation, and fibrosis. As in human rheumatoid arthritis, a number of both pro- and anti-inflammatory cytokines are expressed in the joints of mice with collagen-induced arthritis, including tumor necrosis factor-alpha (TNFalpha) and interleukin (IL)-1beta, IL-6, IL-1Ra, IL-10, and transforming growth factor beta. The use transgenic and knockout strains of mice, as well as biological inhibitors, have revealed important pathological roles for multiple cytokines. Of these, TNFalpha emerged as a valid therapeutic target for rheumatoid arthritis and this led to the setting up of clinical trials of anti-TNFalpha antibody therapy. Three anti-TNFalpha biologics(infliximab, etanercept, and adalimumab) are now approved for use and TNFalpha blockade therefore represents an important advance in our ability to treat rheumatoid arthritis.

Acute and subchronic oral toxicity studies in rats of a hydrolyzed chicken sternal cartilage preparation

Two acute and subchronic oral toxicity studies were conducted in rats to evaluate safety of a patented preparation of hydrolyzed chicken sternal cartilage (BioCell Collagen II) containing collagen type II, chondroitin sulfate, and hyaluronic acid. In the acute oral toxicity study, five males and five females of Sprague-Dawley rats were administered a single dose of 5000 mg of the test product per kg body weight and observed for 14 days. All animals survived and exhibited normal body weight gain throughout the study. Macroscopic necropsy examination conducted on day 15 revealed no gross pathological lesions in any of the animals. In the subchronic study, Sprague-Dawley rats (40 males, 40 females) were divided into four same-sex groups (10 animals/group). Animals in each group were administered daily either 0, 30, 300 or 1000 mg of the test product per kg of body weight for over 90 days. All animals survived and showed no significant changes in their body weights and histopathology. Although some differences were observed between the treated and control animals in several parameters, they were generally not dose-related or considered to be of toxicological significance. In conclusion, the results from the two oral toxicity studies with male and female young adult rats indicated that the test preparation from hydrolyzed chicken sternal cartilage collagen (BioCell Collagen II) was well tolerated at all four doses tested.

Immunosuppressive activity of deer antler extracts of Cervus korean TEMMINCK var. mantchuricus Swinhoe, on type II collagen-induced arthritis

Unossified horn or pilose antler cut from deer, which belong to the Cervidae generally is termed Nokyong. Nokyong is one of the most famous Korean traditional medicines and has been considered to possess sexual-reinforcing and antiaging actions. In this study, water extract of deer antler extract (DAA) prepared from the growing antler of Cervus korean TEMMINCK var. mantchuricus Swinhoe was used to investigate the efficacy of the DAA on the development of type II collagen (CII)-induced arthritis (CIA) in rats. Male rats were immunized with an emulsion of 200 microg of CII and complete Freund's adjuvant (CFA). The rats then were administered by injection a suspension of DAA or phosphate-buffered saline. The effect of DAA on cellular responses to CII was examined. The injection of DAA suppressed the CII-specific secretion of interferon (IFN)-gamma from splenocytes ex vivo. The influence of DAA also was evaluated on the incidence and development of arthritis in rat CIA. Rats were immunized twice at a 3-wk interval with bovine CII, with DAA being given by injection once a d for 14 d with four different regimens. A 14-d course of DAA treatment at a daily dose of 100 microg/kg, which began on the d of the first CII immunization, suppressed the development of arthritis, as well as antibody formation and delayed-type hypersensitivity to CII. Treatment with DAA resulted in inhibition of development of arthritis and immune responses to CII.

FR180204, a novel and selective inhibitor of extracellular signal-regulated kinase, ameliorates collagen-induced arthritis in mice

Extracellular signal-regulated kinase (ERK), a serine/threonine protein kinase of the mitogen-activated protein kinase superfamily, is activated by various stimuli in inflammatory cells. We recently described FR180204 (5-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)-1H-pyrazolo[3,4-c]pyridazin-3-amine), a novel selective ERK inhibitor. In this paper, we investigated the effect of FR180204 on collagen-induced arthritis (CIA) in DBA/1 mice, an animal model of rheumatoid arthritis (RA) mediated by type II collagen (CII)-reactive T cells and anti-CII antibodies. Preventive administration of FR180204 (100 mg/kg, i.p., b.i.d.) significantly ameliorated the clinical arthritis and body weight loss occurring in the CIA mice. Further, FR180204-treated mice showed a significant decrease in plasma anti-CII antibody levels (62%). FR180204 also attenuated delayed-type hypersensitivity in CII-immunized DBA/1 mice, an inflammatory response elicited by CII-reactive T cells, in a dose-dependent manner (52 and 62% inhibition at 32 and 100 mg/kg, respectively). Moreover, FR180204 inhibited in vitro CII-induced proliferation of lymph node cells prepared from CII-immunized mice, in which CII-specific T cells are known to undergo specific proliferation. In conclusion, our results suggest that ERK regulates both the cell-mediated and humoral immune responses in the development of CIA. ERK inhibitors may be useful as therapeutic reagents for the treatment of RA.

CD69 targeting differentially affects the course of collagen-induced arthritis

CD69 expression is induced following activation of leukocytes at inflammatory sites and plays a negative regulatory role in the development of collagen-induced arthritis (CIA). To evaluate potential strategies of CD69 targeting in chronic inflammatory diseases, two different anti-CD69 mAbs were generated and their effects on CIA were studied. Administration of the IgG1 anti-CD69 mAb 2.2 to DBA/1 mice with CIA led to an exacerbation of the disease, correlated with down-modulation of CD69 from the cell surface, and reproduced the phenotype of the CD69(-/-) mouse in wild-type animals. In contrast, treatment with the IgG2a anti-CD69 mAb 2.3 was effective in ameliorating CIA when administered in the early or intermediate phases of the disease, causing a decreased production of proinflammatory cytokines in inflammatory foci. Monoclonal antibody 2.3 induces partial depletion of CD69+ cells in vivo. Moreover, adoptive transfer of type-II collagen (CII)-sensitized cells treated with mAb 2.3 to deplete CD69+ cells did not result in arthritis. The attenuation of inflammation correlates with reduced lymphocyte proliferative response in response to CII and with a reduction in the frequency of CII-specific T cells producing IFN-gamma. We thus conclude that CD69 targeting by mAbs can either enhance or dampen the immune response.

The role and clinical implications of G6PI in experimental models of rheumatoid arthritis

The antigens that trigger the pathogenic immune response in rheumatoid arthritis (RA) remain unknown. Until recently it was assumed that either viral or microbial antigens, or joint-specific antigens were the target of arthritogenic T and B lymphocytes in RA. Consequently, murine models of arthritis are induced by immunization with either joint-specific antigens such as type II collagen or microbial products such as streptococcal cell wall. In the K/B×N T-cell receptor transgenic mouse model arthritis is caused by a systemic autoimmune response to the ubiquitously expressed glycolytic enzyme glucose-6-phosphate isomerase (G6PI). The autoreactive transgenic T cells recognize G6PI and provide help for the production of arthritogenic IgG antibodies against G6PI. More recently it was shown that G6PI immunization induces severe symmetrical peripheral polyarthritis in genetically unaltered DBA/I mice. In that model CD4⁺ T cells are necessary not only for the induction but also for the effector phase of arthritis. Here we review the pathomechanisms that lead from systemic autoreactivity to arthritis in these models, consider the relevance of anti-G6PI immune reactivity for RA, and discuss the insights into the pathogenesis of RA and possibly other autoimmune conditions that can be gained from these models.

Effect of (3,5,6-Trimethylpyrazin-2-yl)methyl 2-[4-(2-Methylpropyl)-phenyl] propanoate (ITE), a Newly Developed Anti-inflammatory Drug, on Type II Collagen-Induced Arthritis in Mice

The effect of (3,5,6-trimethylpyrazin-2-yl)methyl 2-[4-(2-methylpropyl)phenyl]propanoate (ITE) on type II collagen (CII)-induced arthritis in mice was studied. Mice were immunized twice with CII, ITE being given orally once a day for 40 d after the 1st immunization. Clinical assessment showed that ITE had no effect on the day of onset of arthritis but did lowered the incidence rate of arthritis and the arthritis score. And ITE had a marked suppressive effect on the mouse hind paw edema induced by CII. ITE suppressed the delayed-type mouse ear skin reaction to CII but had no effect on the level of serum anti-CII antibodies. These results suggest that ITE inhibits the development of CII-induced arthritis in mice by suppressing delayed-type hypersensitivity to CII.