| 1. |
|
|
| 2. |
- Hansson, Ann-Sofie, et al.
(författare)
-
Relapsing polychondritis, induced in mice with matrilin 1, is an antibody- and complement-dependent disease
- 2004
-
Ingår i: American Journal of Pathology. - New York, NY : Elsevier. - 0002-9440 .- 1525-2191. ; 164:3, s. 959-966
-
Tidskriftsartikel (refereegranskat)abstract
- Relapsing polychondritis is an autoimmune disease that affects cartilage in the ear, nose, and respiratory tract. A pathogenic immune response has been proposed and antibodies to several cartilage proteins are detected in sera from these patients. To investigate the role of the humoral immune response in relapsing polychondritis, we used the matrilin-1-induced relapsing polychondritis model. Mice deficient of B cells (muMT) and mice congenic at the complement factor 5, were immunized with matrilin-1, a cartilage-specific protein mainly detected in the tracheal cartilage. To investigate the binding properties and tissue selection of matrilin-1-specific antibodies we produced matrilin-1-specific B-cell hybridomas. Although 83% of the micro MT heterozygous mice developed respiratory distress and erosive chondritis in the respiratory tract, none of the B-cell-deficient mice were susceptible to disease. In addition, we show that complement factor 5 is important for the induction of matrilin-1-induced relapsing polychondritis. Monoclonal matrilin-1-specific antibodies injected into neonatal mice bound specifically to cartilage of the respiratory tract and adult B-cell-deficient mice injected with the same antibodies developed erosive chondritis in the respiratory tract. We conclude that relapsing polychondritis can be mediated by a pathway involving tissue-specific antibodies and complement activation.
|
|
| 3. |
- Jormsjo, Sofia, et al.
(författare)
-
Differential expression of cysteine and aspartic proteases during progression of atherosclerosis in apolipoprotein E-deficient mice
- 2002
-
Ingår i: American Journal of Pathology. - 1525-2191 .- 0002-9440. ; 161:3, s. 939-945
-
Tidskriftsartikel (refereegranskat)abstract
- Several groups of proteolytic enzymes are able to degrade components of the extracellular matrix. During atherosclerosis, matrix remodeling is believed to influence the migration and proliferation of cells within the plaque. In the present study, gene expression of several proteases and their inhibitors was analyzed during the development of atherosclerosis in apolipoprotein E-deficient (ApoE-/-) mice. Quantitative real-time polymerase chain reaction was used to study gene expression of proteases after 10 and 20 weeks in ApoE-/- and C57BL/6 mice and in atherosclerotic lesions and nonaffected regions of the same ApoE-/- mouse. Some of the differentially expressed proteolytic enzymes were studied by immunohistochemistry. The matrix metalloproteinase (MMP)-9 and its inhibitor TIMP-1 were differentially expressed and the expression increased with time. Urokinase-type plasminogen activator showed no major expression. In contrast, cathepsins B, D, L, and S all showed strong and increased expression in ApoE-/- mice compared to C57BL/6 mice whereas the expression of their inhibitor, cystatin C, did not differ between the two mouse strains. The expression of cathepsins was mainly localized to the lesions and not to nonaffected regions of the aorta of ApoE-/- mice. Furthermore, cathepsin expression was similar to the expression of the macrophage marker macrosialin (CD68) although expression of cathepsins B, D, and L could be demonstrated in healthy C57BL/6 mice and in nonaffected vessel segments of atherosclerotic ApoE-/- mice. Cathepsin S mRNA expression was restricted to lesions of ApoE-/- mice. Furthermore, cathepsin S was the only cathepsin that was expressed in the media and absent in lipid-rich regions. All cathepsins studied showed intimal expression, the degree and localization of which differed between individual cathepsins. In conclusion, increased expression of several cathepsins in atherosclerotic lesions suggests that these proteases may participate in the remodeling of extracellular matrix associated with the atherosclerotic process.
|
|
| 4. |
- Krettek, Alexandra, 1968-, et al.
(författare)
-
Enhanced expression of CD44 variants in human atheroma and abdominal aortic aneurysm : possible role for a feedback loop in endothelial cells
- 2004
-
Ingår i: American Journal of Pathology. - : Elsevier. - 0002-9440 .- 1525-2191. ; 165:5, s. 1571-1581
-
Tidskriftsartikel (refereegranskat)abstract
- CD44, a polymorphic hyaluronate receptor, may participate in chronic inflammation. We hypothesized that CD44 variants contribute to the development of arterial diseases. CD44 levels vary in normal and diseased arterial tissues in the following order: unaffected arteries < fibrous plaques < or = abdominal aortic aneurysm < atheromatous plaques; and correlate with macrophage content. Furthermore, plaque microvessels express CD44, and anti-CD44v3 or anti-CD44v6 treatment reduces endothelial cell proliferation but not apoptosis in vitro, suggesting functionality of these receptors. Endothelial cells express CD44H and CD44v6 after exposure to interleukin-1beta and tumor necrosis factor-alpha. Macrophages, a major source of abundant CD44 in vitro, express not only CD44H but also variants CD44v4/5, CD44v6, and CD44v7/8, isoforms distinctively regulated by proinflammatory cytokines. Several proinflammatory cytokines induce shedding of CD44 from the surface of macrophages and endothelial cells. Soluble CD44 stimulates the expression and release of interleukin-1beta from endothelial cells, suggesting a positive feedback loop of this cytokine. By demonstrating augmented expression of CD44 and variants within human atheroma and in abdominal aortic aneurysm as well as the vascular cell release of sCD44, a process regulated by proinflammatory cytokines, this study provides new insights on the functions of CD44 in arterial diseases.
|
|
| 5. |
- Li, Jinan, et al.
(författare)
-
The plasminogen activator/plasmin system is essential for development of the joint inflammatory phase of collagen type II-induced arthritis.
- 2005
-
Ingår i: American Journal of Pathology. - New York : Elsevier. - 0002-9440 .- 1525-2191. ; 166:3, s. 783-792
-
Tidskriftsartikel (refereegranskat)abstract
- The plasminogen activator (PA) system has been proposed to have important roles in rheumatoid arthritis. Here we have used the autoimmune collagen type II (CII)-induced arthritis (CIA) model and mice deficient for urokinase-type PA (uPA) or plasminogen to investigate the role of the PA system for development of arthritis. Our data revealed that uPA-deficient mice have a lower severity and incidence of CIA than wild-type mice. Furthermore, although >80% of wild-type control mice developed CIA, we found that none of the 50 plasminogen-deficient littermates that were tested developed CIA within a 40-day period. Antibody generation after CII immunization as well as the binding of labeled anti-CII antibodies to the surface of cartilage were similar in wild-type and plasminogen-deficient mice. No sign of inflammation was seen when plasminogen-deficient mice were injected with a mixture of monoclonal antibodies against CII. However, after daily injections of human plasminogen, these mice developed arthritis within 5 days. Our finding that infiltration of inflammatory cells into the synovial joints was impaired in plasminogen-deficient mice suggests that uPA and plasminogen are important mediators of joint inflammation. Active plasmin is therefore essential for the induction of pathological inflammatory joint destruction in CIA.
|
|
| 6. |
- Ling, G., et al.
(författare)
-
Persistent p53 mutations in single cells from normal human skin
- 2001
-
Ingår i: American Journal of Pathology. - 0002-9440 .- 1525-2191. ; 159:4, s. 1247-1253
-
Tidskriftsartikel (refereegranskat)abstract
- Epidermal clones of p53-mutated keratinocytes are abundant in chronically sun-exposed skin and may play an important role in early development of skin cancer. Advanced laser capture microdissection enables genetic analysis of targeted cells from tissue sections without contamination from neighboring cells. In this study P53 gene mutations were characterized in single cells from normal, chronically sun-exposed skin. Biopsies were obtained from skin subjected to daily summer sun and skin totally protected from the sun by blue denim fabric. Using laser capture microdissection, 172 single-cell samples were retrieved from four biopsies and analyzed using single-cell polymerase chain reaction and direct DNA sequencing. A total of 14 different mutations were identified in 26 of 99 keratinocytes from which the P53 gene could be amplified. Mutations displayed a typical UV signature and were detected in both scattered keratinocytes and in a small cluster of p53-immunoreactive keratinocytes. This minute epidermal P53 clone had a diameter of 10 to 15 basal cells. Two missense mutations were found in all layers of epidermis within the P53 clone. The presented data show that p53 mutations are common in normal skin and that a clone of keratinocytes with a mutated p53 gene prevailed despite 2 months of total protection from ultraviolet light.
|
|
| 7. |
- Nandakumar, Kutty Selva, 1965-, et al.
(författare)
-
Collagen type II-specific monoclonal antibody-induced arthritis in mice - Description of the disease and the influence of age, sex, and genes
- 2003
-
Ingår i: American Journal of Pathology. - New York : Elsevier. - 1525-2191 .- 0002-9440. ; 163:5, s. 1827-1837
-
Tidskriftsartikel (refereegranskat)abstract
- Transfer of collagen type H (CH)-specific monoclonal antibodies induces an acute form of arthritis (collagen type H antibody-induced arthritis, CAIA) in nave mice. Arthritis was induced using a pair of monoclonal antibodies M2139 and CIIC1, binding to J1 and C1(I) epitopes of CH, respectively. Thereafter, lipopolysaccharide injection was used to increase the incidence and severity of the disease. This model was used to investigate the effect of genes, age, and sex as well as effector cells in the end-stage effector phase of arthritis pathogenesis. Injection of a single monoclonal antibody induced arthritis only after lipopolysaccharide stimulation. CAIA showed differences in disease penetration among the susceptible strains indicating the importance of non-major histocompatibility complex genes on the antibody effector pathway. B-cell-deficient mice were susceptible to CAIA and in some genetic backgrounds B-cell deficiency leads to enhanced arthritis. Histology of the affected paws revealed massive infiltrations of neutrophils along with bone and cartilage erosion, pannus formation, and fibrin deposition. Depletion of neutrophils significantly reduced the incidence and severity of the disease. CAIA susceptibility increased with age. Males were more susceptible than females and estrogen treatment decreased the development of arthritis. We conclude that CAIA is an acute arthritis triggered by antibody binding and neutrophils bypassing immune activation but with many characteristics in common with collagen-induced arthritis.
|
|
| 8. |
- Pontén, Annica, et al.
(författare)
-
Transgenic overexpression of platelet-derived growth factor-C in the mouse heart induces cardiac fibrosis, hypertrophy, and dilated cardiomyopathy
- 2003
-
Ingår i: American Journal of Pathology. - 0002-9440 .- 1525-2191. ; 163:2, s. 673-682
-
Tidskriftsartikel (refereegranskat)abstract
- The platelet-derived growth factors are implicated in development of fibrotic reactions and disease in several organs. We have overexpressed platelet-derived growth factor-C in the heart using the alpha-myosin heavy chain promoter and created a transgenic mouse that exhibits cardiac fibrosis followed by hypertrophy with sex-dependent phenotypes. The transgenic mice developed several pathological changes including cardiac fibroblast proliferation and deposition of collagen, hypertrophy, vascular defects, and the presence of Anitschkow cells in the adult myocardium. Male mice developed a hypertrophic phenotype, whereas female mice were more severely affected and developed dilated cardiomyopathy, leading to heart failure and sudden death. The vascular defects initially included dilation of microvessels and vascular leakage. Subsequently, a marked loss of microvessels, formation of large vascular sac-like structures, and an increased density of smooth muscle-coated vessels were observed in the myocardium. In part, the observed vascular changes may be because of an up-regulation of vascular endothelial growth factor in cardiac fibroblasts of the transgenic hearts. This unique animal model reveals that a potent mitogen for cardiac fibroblasts result in an expansion of the interstitium that induce a secondary sex-dependent hypertrophic response in the cardiomyocytes.
|
|
| 9. |
- Roberg, Karin, et al.
(författare)
-
Microinjection of cathepsin D induces caspase-dependent apoptosis in fibroblasts
- 2002
-
Ingår i: American Journal of Pathology. - 0002-9440 .- 1525-2191. ; 161:1, s. 89-96
-
Tidskriftsartikel (refereegranskat)abstract
- Recent reports have indicated that enzymes such as cathepsins D and B are translocated from lysosomal compartments to the cytosol early during apoptosis. We have previously noted that a translocation of cathepsins D and B occur before cytochrome c release and caspase activation in cardiomyocytes and human fibroblasts during oxidative stress-induced apoptosis. In the present report, we use a microinjection technique to investigate if cytosolic location of the cathepsins D and B are important for induction of apoptosis. We found that microinjection of cathepsin D into the cytosol of human fibroblasts caused apoptosis, which was detected as changes in distribution of cytochrome c, cell shrinkage, activation of caspases, chromatin condensation, and formation of pycnotic nuclei. No apoptosis was, however, induced by microinjection of cathepsin B. Moreover, apoptosis was prevented in fibroblasts pretreated with a caspase-3-like inhibitor, and also when microinjected with cathepsin D mixed with the cathepsin D inhibitor, pepstatin A. These results show that cytosolic cathepsin D can act as a proapoptotic mediator upstream of cytochrome c release and caspase activation in human fibroblasts.
|
|
| 10. |
- Stenman, Mathias, et al.
(författare)
-
Trypsin-2 degrades human type II collagen and is expressed and activated in mesenchymally transformed rheumatoid arthritis synovitis tissue
- 2005
-
Ingår i: American Journal of Pathology. - 1525-2191 .- 0002-9440. ; 167:4, s. 1119-1124
-
Tidskriftsartikel (refereegranskat)abstract
- It has traditionally been believed that only the human collagenases (matrix metalloproteinase-1, -8, and -13) are capable of initiating the degradation of collagens. Here, we show that human trypsin-2 is also capable of cleaving the triple helix of human cartilage collagen type II. We purified human trypsin-2 and tumor-associated trypsin inhibitor by affinity chromatography whereas collagen type II was purified from cartilage extracts using pepsin digestion and salt precipitation. Degradation of type II collagen and gelatin by trypsin-2 was demonstrated with sodium dodecyl sulfate-polyacrylamide gel electrophoresis, zymography, and mass spectrometry, and tumor-associated trypsin inhibitor specifically inhibited this degradation. Although human trypsin-2 efficiently digested type II collagen, bovine trypsin did not. Furthermore, immunohistochemical staining detected trypsin-2 in the fibroblast-like synovial lining and in stromal cells of human rheumatoid arthritis synovial membrane. These findings were confirmed by reverse transcriptase-polymerase chain reaction and nucleotide sequencing. Trypsin-2 alone and complexed with alpha(1)-proteinase inhibitor were also detected in the synovial fluid of affected joints by time-resolved immunofluorometric assay, suggesting that trypsin-2 is activated locally. These results are the first to assess the ability of human trypsin to cleave human type II collagen. Thus, trypsin-2 and its regulators should be further studied for use as markers of prognosis and disease activity in rheumatoid arthritis.
|
|
