Temporomandibular joint (TMJ) disc displacement is one of the most significant subtypes of temporomandibular joint disorders, but its etiology and mechanism are poorly understood. In this study, we elucidated the mechanisms by which destruction of inflamed collagen fibrils induces alterations in the mechanical properties and positioning of the TMJ disc. By constructing a rat model of TMJ arthritis, we observed anteriorly dislocated TMJ discs with aggravated deformity in vivo from five weeks to six months after a local injection of Freund's complete adjuvant. By mimicking inflammatory conditions with interleukin-1 beta in vitro, we observed enhanced expression of collagen-synthesis markers in primary TMJ disc cells cultured in a conventional two-dimensional environment. In contrast, three-dimensional (3D)-cultivated disc cell sheets demonstrated the disordered assembly of inflamed collagen fibrils, inappropriate arrangement, and decreased Young's modulus. Mechanistically, inflammation-related activation of the nuclear factor kappa-B (NF-κB) pathway occurs during the progression of TMJ arthritis. NF-κB inhibition reduced the collagen fibril destruction in the inflamed disc cell sheets in vitro, and early NF-κB blockade alleviated collagen degeneration and dislocation of the TMJ discs in vivo. Therefore, the NF-κB pathway participates in the collagen remodeling in inflamed TMJ discs, offering a potential therapeutic target for disc displacement.
Animals ; NF-kappa B/metabolism* ; Temporomandibular Joint Disorders/pathology* ; Temporomandibular Joint Disc/metabolism* ; Rats ; Rats, Sprague-Dawley ; Disease Models, Animal ; Male ; Collagen/metabolism* ; Cells, Cultured ; Joint Dislocations/pathology* ; Interleukin-1beta ; Arthritis, Experimental

Andrographolide sulfonate (AS) is a sulfonated derivative of andrographolide extracted from Andrographis paniculata (Burm.f.) Nees, and has been approved for several decades in China. The present study aimed to investigate the novel therapeutic application and possible mechanisms of AS in the treatment of rheumatoid arthritis. Results indicated that administration of AS by injection or gavage significantly reduced the paw swelling, improved body weights, and attenuated pathological changes in joints of rats with adjuvant-induced arthritis. Additionally, the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IL-1β in the serum and ankle joints were reduced. Bioinformatics analysis, along with the spleen index and measurements of IL-17 and IL-10 levels, suggested a potential relationship between AS and Th17 cells under arthritic conditions. In vitro, AS was shown to block Th17 cell differentiation, as evidenced by the reduced percentages of CD4⁺ IL-17A⁺ T cells and decreased expression levels of RORγt, IL-17A, IL-17F, IL-21, and IL-22, without affecting the cell viability and apoptosis. This effect was attributed to the limited glycolysis, as indicated by metabolomics analysis, reduced glucose uptake, and pH measurements. Further investigation revealed that AS might bind to hexokinase2 (HK2) to down-regulate the protein levels of HK2 but not glyceraldehyde-3-phosphate dehydrogenase (GAPDH) or pyruvate kinase M2 (PKM2), and overexpression of HK2 reversed the inhibition of AS on Th17 cell differentiation. Furthermore, AS impaired the activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signals in vivo and in vitro, which was abolished by the addition of lactate. In conclusion, AS significantly improved adjuvant-induced arthritis (AIA) in rats by inhibiting glycolysis-mediated activation of PI3K/AKT to restrain Th17 cell differentiation.
Animals ; Th17 Cells/immunology* ; Diterpenes/pharmacology* ; Arthritis, Rheumatoid/metabolism* ; Proto-Oncogene Proteins c-akt/immunology* ; Glycolysis/drug effects* ; Cell Differentiation/drug effects* ; Phosphatidylinositol 3-Kinases/genetics* ; Rats ; Male ; Rats, Sprague-Dawley ; Humans ; Andrographis paniculata/chemistry* ; Arthritis, Experimental/drug therapy* ; Interleukin-17/immunology* ; Signal Transduction/drug effects*

OBJECTIVE: To investigate the effects of 4-methylcatechol (4MC) on the migration and inflammatory response in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS), as well as its underlying mechanisms of action. METHODS: RA-FLS was isolated from synovial tissue donated by RA patients, and the optimal concentration of 4MC was determined by cell counting kit 8 method for subsequent experiments, and the effect of 4MC on the migratory ability of RA-FLS was evaluated via a cell scratch assay. An inflammation model of RA-FLS was induced by tumor necrosis factor α (TNF-α). Real-time fluorescence quantitative PCR and ELISA were employed to detect the gene and protein expression levels of interleukin-1β (IL-1β) and IL-6 in RA-FLS and their culture supernatants, respectively, thereby investigating the anti-inflammatory effects of 4MC. Western blot was used to examine the expressions of nuclear factor κB (NF-κB) signaling pathway-related proteins, including inhibitor of NF-κB-α (IKBα), phosphorylated (P)-IκBα, NF-κB-inducing kinase α (IKKα), P-IKKαβ, P-p65, and p65. Cellular immunofluorescence was utilized to detect the expression and localization of p65 in RA-FLS, exploring whether 4MC exerts its anti-inflammatory effects by regulating the NF-κB signaling pathway. Finally, a collagen-induced arthritis (CIA) mouse model was established. The anti-RA effect of 4MC in vivo was evaluated by gross observation and histological examination. RESULTS: 4MC inhibited RA-FLS migration in a concentration-dependent manner. In the TNF-α-induced RA-FLS inflammation model, 4MC significantly decreased the gene and protein expression levels of IL-1β and IL-6. Furthermore, 4MC markedly reduced the ratios of P-IΚBα/IΚBα, P-IKKαβ/IKKα, and P-p65/p65, thereby blocking the transcriptional activity of p65 by inhibiting its nuclear translocation. This mechanism effectively suppressed the activation of the TNF-α-mediated NF-κB signaling pathway. Animal studies demonstrated that 4MC [10 mg/(kg·day)] significantly lowered serum levels of IL-1β, IL-6, and TNF-α, and alleviated arthritis severity and bone destruction in CIA mice. CONCLUSION 4MC not only inhibits the migration of RA-FLS but also mitigates their inflammatory response by suppressing the NF-κB signaling pathway, thereby effectively exerting its anti-RA effects.
Synoviocytes/metabolism* ; Arthritis, Rheumatoid/metabolism* ; Animals ; Cell Movement/drug effects* ; Humans ; Catechols/therapeutic use* ; Fibroblasts/drug effects* ; Mice ; Tumor Necrosis Factor-alpha/pharmacology* ; Interleukin-1beta/metabolism* ; Interleukin-6/metabolism* ; Signal Transduction/drug effects* ; NF-kappa B/metabolism* ; Transcription Factor RelA/metabolism* ; Synovial Membrane/cytology* ; Cells, Cultured ; Male ; Arthritis, Experimental ; Anti-Inflammatory Agents/pharmacology* ; NF-KappaB Inhibitor alpha ; Inflammation

Objective Based on 25 indicators including immune factors, cell count classification, and smear results of the knee joint fluid, machine learning models were established to distinguish between osteoarthritis (OA) and rheumatoid arthritis (RA). Methods 100 OA and 40 RA patients scheduled for total knee arthroplasty were enrolled respectively. Each patient's knee joint fluid was collected preoperatively. Nucleated cells were counted and classified. The expression levels of immune factors, including tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6, IL-8, IL-15, matrix metalloproteinase 3 (MMP3), MMP9, MMP13, rheumatoid factor (RF), serum amyloid A (SAA), C-reactive protein (CRP), and others were measured. Smears and microscopic classification of all the immune factors were performed. Independent influencing factors for OA or RA were identified using univariate binary logistic regression, Lasso regression, and multivariate binary logistic regression. Based on the independent influencing factors, three machine learning models were constructed which are logistic regression, random forest, and support vector machine. Receiver operating characteristic curve (ROC), calibration curve and decision curve analysis (DCA) were used to evaluate and compare the models. Results A total of 5 indicators in the knee joint fluid were screened out to distinguish OA and RA, which were IL-1β(odds ratio(OR)=10.512, 95× confidence interval (95×CI) was 1.048-105.42, P=0.045), IL-6 (OR=1.007, 95×CI was 1.001-1.014, P=0.022), MMP9 (OR=3.202, 95×CI was 1.235-8.305, P=0.017), MMP13 (OR=1.002, 95× CI was 1-1.004, P=0.049), and RF (OR=1.091, 95×CI was 1.01-1.179, P=0.026). According to the results of ROC, calibration curve and DCA, the accuracy (0.979), sensitivity (0.98) and area under the curve (AUC, 0.996, 95×CI was 0.991-1) of the random forest model were the highest. It has good validity and feasibility, and its distinguishing ability is better than the other two models. Conclusion The machine learning model based on immune factors in the knee joint fluid holds significant value in distinguishing OA and RA. It provides an important reference for the clinical early differential diagnosis, prevention and treatment of OA and RA.
Humans ; Arthritis, Rheumatoid/metabolism* ; Machine Learning ; Male ; Female ; Middle Aged ; Aged ; Synovial Fluid/immunology* ; Osteoarthritis, Knee/metabolism* ; Knee Joint/metabolism* ; ROC Curve ; Diagnosis, Differential

Objective To investigate the effects of hyaluronic acid and proteoglycan-linked protein 1 (HAPLN1) secreted by synovial fibroblasts (FLS) on the polarization of macrophages (Mϕ) in rheumatoid arthritis (RA). Methods Human monocytic leukemia cells (THP-1) were differentiated into Mϕ, which were subsequently exposed to recombinant HAPLN1 (rHAPLN1). RA-FLS were transfected separately with HAPLN1 overexpression plasmid (HAPLN1^OE) or small interfering RNA targeting HAPLN1 (si-HAPLN1), and then co-cultured with Mϕ to establish a co-culture model. The viability of Mϕ was assessed using the CCK-8 assay, and the proportions of pro-inflammatory M1-type and anti-inflammatory M2-type Mϕ were analyzed by flow cytometry. Additionally, the expression levels of inflammatory markers, including interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), and inducible nitric oxide synthase (iNOS), were quantified using quantitative real-time PCR and Western blot analysis. Results The viability of Mϕ was increased in the rHAPLN1 group compared to the control group. Furthermore, both the M1/Mϕ ratio and inflammatory factor levels were elevated in the rHAPLN1 and HAPLN1^OE groups. In contrast, the si-HAPLN1 group exhibited a decrease in the M1/Mϕ ratio and inflammatory factor expression. Notably, the introduction of rHAPLN1 in rescue experiments further promoted Mϕ polarization towards the M1 phenotype. Conclusion HAPLN1, secreted by RA fibroblast-like synoviocytes (RA-FLS), enhances Mϕ polarization towards the M1 phenotype.
Humans ; Arthritis, Rheumatoid/genetics* ; Macrophages/immunology* ; Fibroblasts/metabolism* ; Phenotype ; Extracellular Matrix Proteins/genetics* ; Proteoglycans/genetics* ; Synovial Membrane/cytology* ; Tumor Necrosis Factor-alpha/genetics* ; Interleukin-1beta/genetics* ; Nitric Oxide Synthase Type II/genetics* ; Cell Differentiation ; Coculture Techniques ; THP-1 Cells

Objective To explore the expression of coagulation indexes in rheumatoid arthritis (RA) and dry syndrome (pSS) and their relationships with inflammation and immune function. Methods A total of 61 patients with RA who were hospitalized in the Department of Rheumatology of Anhui Provincial Hospital of Traditional Chinese Medicine from March 12 to September 9, 2024 were selected as the RA group. And 61 patients with pSS who were hospitalized in the Department of Rheumatology of the same hospital September 4, 2023, to August 17, 2024, were selected as the pSS group. 61 healthy individuals who underwent routine medical checkups at the Physical Examination Center of Anhui Provincial Hospital of Traditional Chinese Medicine during the same period were included as the control group. Baseline clinical indexes before treatment were collected from patients in each group, including prothrombin time(PT), international normalized ratio(INR), thrombia time(TT), fibrinogen(FBG), activated partial thromboplastin time(APTT), fibrin (ogen) degradation products(FDP) and D-Dimer(D-D). Results The expression levels of PT, FBG, TT, FDP, and D-D in the RA group, the pSS group, and the normal group were significantly different. The expression levels of PT, FBG, FDP, and D-D in the RA group were all higher than those in the pSS group and the control group, respectively. And the expression level of TT in the pSS group was lower than that in control group. ROC curve analysis showed that the AUC of PT was 0.638, the AUC of FBG was 0.899, the AUC of FDP was 0.866, and the AUC of D-D was 0.919 in the RA group compared with the normal group. And the AUC of coagulation indexes for joint diagnosis of RA was higher than that of the indexes detected individually. pSS group had an AUC of PT of 0.618 compared with that of the normal group. The AUC of TT was 0.645, and the AUC of coagulation indexes for the joint diagnosis of pSS was higher than the AUC of each index detected separately. Association rule analysis showed that elevated D-D in RA patients had a significant correlation with elevated hs-CRP, CCP and RF, and elevated FBG had a significant correlation with elevated hs-CRP, ESR, RF and CCP. Elevated D-D in pSS patients had a correlation with elevated hs-CRP and anti-SSA, and elevated INR has correlation with elevated hs-CRP, anti-SSA and anti-SSB. Correlation analysis showed that PT, INR, FBG, FDP, and D-D were positively correlated with CRP and ESR, and TT was negatively correlated with CRP and ESR in the RA group. FBG, FDP, and D-D were positively correlated with CRP and ESR in the pSS group. Moreover, coagulation indexes were positively correlated with immune indexes in RA group and pSS group which were all significant. The results of multiple linear regression analysis showed that FBG was a positive correlate of hs-CRP and ESR in RA patients. For PSS patients, FBG and FDP were positive correlates of hs-CRP. APTT and FBG were positive correlates of ESR. Conclusion Compared with pSS, coagulation indexes (especially PT, FBG, FDP and D-D) are more informative for the early diagnosis of RA and the judgment of the degree of the disease, and can be used as an important predictor for the confirmation of the diagnosis of RA.
Humans ; Female ; Male ; Arthritis, Rheumatoid/diagnosis* ; Middle Aged ; Fibrin Fibrinogen Degradation Products/analysis* ; Blood Coagulation ; Adult ; Fibrinogen/metabolism* ; Partial Thromboplastin Time ; Prothrombin Time ; Aged ; Inflammation/immunology* ; ROC Curve

OBJECTIVE: To elucidate the role and underlying mechanism of ubiquitin-specific protease 35 (USP35) in ferroptosis of rheumatoid arthritis-fibroblast like synoviocytes (RA-FLS), thereby enhancing our comprehension of the pathogenesis of RA and identifying potential therapeutic targets for its treatment. METHODS: (1) RA-FLS were cultured in vitro and transduced with lentiviral vectors to establish stable cell lines: A USP35-knockdown line (short hairpin ribonucleic acid of USP35, shUSP35) and its control (negtive control of short hairpin ribonucleic acid, shNC), as well as a overexpression of USP35 line (USP35 OE) and its control (Vector). To investigate the role of USP35 in ferroptosis regulation, a ferroptosis model was induced in RA-FLS by treatment with 1 μmol/L Erastin. The cells were divided into six groups: shNC, shNC + Erastin, shUSP35 + Erastin, Vector, Vector + Erastin, and USP35 OE + Erastin. (2) Cell viability was detected using the cell counting kit-8 (CCK-8). (3) Reactive oxygen species (ROS), malondialdehyde (MDA), glutathione/glutathione disulfide (GSH/GSSG) ratios, and Ferrous ion (Fe²⁺) levels were measured using specific assay kits to evaluate oxidative stress, lipid peroxidation, and glutathione redox status in the cells. (4) Protein expression levels of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) were detected using Western blotting to investigate their potential involvement in USP35-mediated ferroptosis regulation. RESULTS: (1) Compared with the shNC +Erastin group, the cell viability of the shUSP35+Erastin group was significantly decreased (P < 0.001), while it was notably increased in the USP35 OE+Erastin group compared with the Vector+Erastin group (P < 0.001). These findings indicated that USP35 could alleviate the inhibitory effect of Erastin on RA-FLS cell viability. (2) In comparison to the shNC+Erastin group, the levels of ROS (P < 0.001), MDA (P < 0.05), and Fe²⁺ (P < 0.001) were significantly elevated, and the GSH/GSSG ratio was increased (P < 0.05) in the shUSP35+Erastin group. Conversely, the levels of ROS (P < 0.001), MDA (P < 0.05), and Fe²⁺ (P < 0.05) were significantly decreased, and the GSH/GSSG ratio was decreased (P < 0.05) in the USP35 OE+Erastin group compared with the Vector+Erastin group. These results suggested that USP35 could inhibit Erastin-induced oxidative stress and lipid peroxidation in RA-FLS. (3) In Erastin-induced RA-FLS, the expression of USP35 was positively correlated with the protein levels of SLC7A11 and GPX4, indicating a potential mechanism by which USP35 regulated ferroptosis in these cells. CONCLUSION USP35 inhibits ferroptosis in RA-FLS, potentially through the increased expression of SLC7A11 and GPX4.
Ferroptosis ; Humans ; Arthritis, Rheumatoid/metabolism* ; Synoviocytes/pathology* ; Reactive Oxygen Species/metabolism* ; Ubiquitin-Specific Proteases/metabolism* ; Fibroblasts/pathology* ; Cell Survival ; Piperazines/pharmacology* ; Endopeptidases/metabolism* ; Cells, Cultured ; Cell Line ; Amino Acid Transport System y+

OBJECTIVE: To explore the mechanism of action of asperosaponin VI (AVI) in the treatment of rheumatoid arthritis (RA) and validate it in ex vivo experiments using network pharmacology and molecular docking methods. METHODS: The predicted targets of AVI were obtained from PharmMaper, UniProt and SwissTarget Prediction platforms, the disease targets were collected from Online Mendelian Inheritance in Man, Therapeutic Target Database and GeneCards databases, the intersection targets of AVI and RA were obtained from Venny 2.1.0, and the protein-protein interaction (PPI) network was obtained from STRING database, which was analyzed by Cytoscape software and screened to obtain the core targets. Cytoscape software was used to analyze PPI network and screen the core targets. Based on the Database for Annotation, Visualization and Integrated Discovery database, Gene Ontology functional and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed, and Cytoscape software was used to construct the "Disease-Pathway-Target-Drug" network, which was finally verified by molecular docking and animal experiments. RESULTS: Network pharmacological studies showed that AVI was able to modulate 289 targets, with 102 targets for the potential treatment of RA, with the core pathway being the AKT/PI3K signaling pathway, and the core targets being the epidermal growth factor receptor (EGFR) and matrix metalloproteinase 9 (MMP9). Molecular docking results showed that AVI could produce strong binding with both of the 2 core targets. In vitro cellular experiments showed that AVI reduced nitric oxide, prostaglandin E₂, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IL-1 β levels (P<0.05) and inhibited cyclooxygenase-2, nitric oxide synthase, EGFR, MMP9, phosphorylated phosphoinositide 3-kinase (p-PI3K), and phosphorylated serine-threonine kinase (p-AKT) proteins (P<0.05). The results of in vivo studies showed that AVI improved RA score and foot swelling thickness and decreased TNF-α, IL-6, p-PI3K and p-AKT levels in RA rats (P<0.05). CONCLUSION AVI exerts anti-inflammatory and anti-RA effects which might be related to the EGFR/MMP9/AKT/PI3K pathway.
Saponins/chemistry* ; ErbB Receptors/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Signal Transduction/drug effects* ; Molecular Docking Simulation ; Animals ; Arthritis, Rheumatoid/drug therapy* ; Proto-Oncogene Proteins c-akt/metabolism* ; Matrix Metalloproteinase 9/metabolism* ; Protein Interaction Maps/drug effects* ; Humans ; Network Pharmacology ; Male ; Rats

The prevalence of rheumatoid arthritis (RA) has sharply increased in recent years, posing a serious threat to human health. RA is characterized as a chronic, multisystem disease with morning stiffness and symmetric small joint pain. However, its fundamental processes are poorly understood. With the advancements in molecular biology techniques, a growing body of research indicates that numerous non-coding RNAs (ncRNAs) are essential for the pathogenesis of RA. These ncRNAs not only contribute to the onset of RA but also play a role in the pathological processes of RA development, including synovial immune inflammation and bone destruction. Chinese medicine (single compounds, single herbs, and compound formulae, as well as non-drug therapies such as acupuncture and moxibustion), offer significant benefits for treating RA. This study examined the role of 3 different ncRNA types (circular RNA, long ncRNA, and microRNA) as biomarkers in RA diagnosis, as well as their regulatory roles in rheumatoid arthritis fibroblast-like synoviocytes functions such as inflammatory response, proliferation, cell cycle, apoptosis, and invasion. Additionally, the study explored the mechanisms by which Chinese medicine regulates these ncRNAs, with the goal of offering innovative strategies for RA treatment.
Arthritis, Rheumatoid/pathology* ; Humans ; RNA, Untranslated/metabolism* ; Medicine, Chinese Traditional ; Synoviocytes/metabolism* ; RNA, Circular ; Biomarkers/metabolism* ; Apoptosis/genetics*

OBJECTIVE: To investigate the common mechanisms among collagen-induced arthritis (CIA), bleomycin (BLM)-induced pulmonary fibrosis, and CIA+BLM to evaluate the therapeutic effect of triptolide (TP) on CIA+BLM. METHODS: Thirty-six male Sprague-Dawley rats were randomly assigned to 6 groups according to a random number table (n=6 per group): normal control (NC), CIA, BLM, combined CIA+BLM model, TP low-dose (TP-L, 0.0931 mg/kg), and TP high-dose (TP-H, 0.1862 mg/kg) groups. The CIA model was induced by intradermal injection at the base of the tail with emulsion of bovine type II collagen and incomplete Freund's adjuvant (1:1), with 200 µL administered on day 0 and a booster of 100 µL on day 7. Pulmonary fibrosis was induced via a single intratracheal injection of BLM (5 mg/kg). The CIA+BLM model combined both protocols, and TP was administered orally from day 14 to 35. After successful modeling, arthritis scores were recorded every 3 days, and pulmonary function was assessed once at the end of the treatment period. Lung tissues were collected for histological analysis (hematoxylin eosin and Masson staining), immunohistochemistry, measurement of hydroxyproline (HYP) content, and calculation of lung coefficient. In addition, HE staining was performed on the ankle joint. Total RNA was extracted from lung tissues for transcriptomic analysis. Differentially expressed genes (DEGs) were compared with those from the RA-associated interstitial lung diseases patient dataset GSE199152 to identify overlapping genes, which were then used to construct a protein-protein interaction network. Hub genes were identified using multiple topological algorithms. RESULTS: The successfully established CIA+BLM rat model exhibited significantly increased arthritis scores and severe pulmonary fibrosis (P<0.01). By intersecting the DEGs obtained from transcriptomic analysis of lung tissues in CIA, BLM, and CIA+BLM rats with DEGs from rheumatoid arthritis-interstitial lung disease patients (GSE199152 dataset), 50 upregulated and 44 downregulated genes were identified. Through integrated PPI network analysis using multiple topological algorithms, IGF1 was identified as a central hub gene. TP intervention significantly improved pulmonary function by increasing peak inspiratory flow (P<0.01), and reduced lung index and HYP content (P<0.01). Histopathological analysis showed that TP alleviated alveolar collapse, interstitial thickening, and collagen deposition in the lung tissues (P<0.01). Moreover, TP treatment reduced the expression of collagen type I and α-SMA and increased E-cadherin levels (P<0.01). TP also significantly reduced arthritis scores and ameliorated synovial inflammation (P<0.05). Both transcriptomic and immunohistochemical analyses confirmed that IGF1 expression was elevated in the CIA+BLM group and downregulated following TP treatment (P<0.05). CONCLUSION TP exerts protective effects in the CIA+BLM model by alleviating arthritis and pulmonary fibrosis through the inhibition of IGF1-mediated EMT.
Animals ; Pulmonary Fibrosis/complications* ; Bleomycin/adverse effects* ; Phenanthrenes/pharmacology* ; Male ; Rats, Sprague-Dawley ; Diterpenes/pharmacology* ; Epoxy Compounds/therapeutic use* ; Arthritis, Experimental/complications* ; Insulin-Like Growth Factor I/metabolism* ; Rats ; Lung/physiopathology*