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Per Eriksson

Publications and source records attributed to Per Eriksson.

60 records · Page 4Linked to original sources

Autoantibodies to C-reactive protein is a common finding in SLE, but not in primary Sjögren's syndrome, rheumatoid arthritis or inflammatory bowel disease.

The occurrence of antibodies to human C-reactive protein (CRP) was analysed by enzyme-linked immunosorbent assay (ELISA) in 56 patient sera known to contain antibodies to double-stranded DNA (dsDNA) and in 16 sera from patients with primary Sjögren's syndrome (SS), 15 rheumatoid arthritis, 31 Crohn's disease, and 37 ulcerative colitis. Eighty-seven per cent of the patients with anti-dsDNA antibodies had systemic lupus erythematosus (SLE) and the remaining had autoimmune hepatitis. The cut-off for positive anti-CRP test was set at the 95th percentile of 100 healthy blood donors. Twenty of 56 anti-dsDNA sera (36%) and two of 16 SS sera (13%) had antibodies reactive with human CRP, whereas all other samples were negative. Thirteen of 27 SLE patients (48%) were positive on at least one occasion. The sera containing anti-CRP antibodies only reacted with surface-bound antigen, but not with native CRP in solution. In conclusion, we found that autoantibodies to CRP are common in sera from patients with anti-dsDNA antibodies. It is not likely that this explains the relative failure of CRP response in patients with active SLE. However, it cannot be excluded that anti-CRP autoantibodies have other biological potentials of pathophysiological interest in SLE, for instance by binding to CRP deposited on cell and tissue surfaces.

Adult↗

Differential expression of cysteine and aspartic proteases during progression of atherosclerosis in apolipoprotein E-deficient mice.

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.

Animals↗

Linoleic acid-stimulated vascular adhesion molecule-1 expression in endothelial cells depends on nuclear factor-kappaB activation.

Endothelial activation is an important step in atherogenesis. In addition to established cardiovascular risk factors, such as hypercholesterolemia, hypertension, diabetes mellitus, and homocysteinemia, high plasma levels of triglyceride-rich lipoproteins may be an important cause of endothelial activation as well. Free fatty acids hydrolyzed from core triglycerides of these particles can exert both pro- and anti-inflammatory effects on the vascular wall. omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have been shown to inhibit cytokine-induced endothelial activation. In contrast, we and others have previously shown that the omega-6 fatty acid linoleate activates transcription factor nuclear factor-kappaB (NF-kappaB) in endothelial cells. In this study, we show that linoleic acid stimulates vascular adhesion molecule-1 (VCAM-1) protein and mRNA expression in cultured human endothelial cells, as assessed by immunofluorescence and Northern blotting. Release of shedded soluble VCAM-1 from cultured human endothelial cells was also increased by the addition of linoleic acid, as determined by enzyme-linked immunosorbent assay (ELISA). By use of cultured rat aortic endothelial cells transfected with an IkappaB super-repressor (DeltaN2 cells), we provide evidence that NF-kappaB signalling is required in the linoleic acid-induced VCAM-1 expression in endothelial cells, whereas other transcription factors appear to be involved in the increased endothelial plasminogen activator inhibitor-1 (PAI-1) production in response to linoleic acid. These findings suggest that diets rich in linoleic acid may be proinflammatory and thus atherogenic by activating vascular endothelial cells.

Animals↗

Neonatal exposure to the brominated flame retardant 2,2',4,4',5-pentabromodiphenyl ether causes altered susceptibility in the cholinergic transmitter system in the adult mouse.

Polybrominated diphenyl ethers (PBDEs) are used as flame-retardants and have recently been shown to be increasing in the environment and in human mother's milk. We have recently reported that neonatal exposure to 2,2',4,4',5-pentaBDE (PBDE 99) can induce persistent aberrations in spontaneous behavior and also affect learning and memory functions in the adult animal. The present study indicates that the cholinergic system, in its developing stage, may be a target of and sensitive to PBDEs. Neonatal exposure of male NMRI mice on postnatal day 10, to 2,2',4,4',5-pentaBDE (8 mg/kg bw) was shown to alter the response to a cholinergic agent, nicotine, at an adult age. The nicotine-induced behavior test revealed a hypoactive response to nicotine in PBDE 99-treated animals, whereas the response of controls was an increased activity. These findings show similarities to observations made from neonatal exposure to PCBs and nicotine, compounds shown to affect cholinergic nicotinic receptors. This indicates that PBDE 99 can affect the cholinergic system and might thereby interact with other environmental toxicants.

Animals↗

Subclinical myositis is common in primary Sjögren's syndrome and is not related to muscle pain.

OBJECTIVE: Although muscle pain is common in primary Sjögren's syndrome (SS), the underlying mechanisms are mainly unknown. We studied all patients with SS at our rheumatology unit with respect to muscle pain in general and to fibromyalgia (FM), and correlated clinical data to muscle biopsy findings. METHODS: We investigated 48 patients with SS according to the modified European diagnostic criteria. The ACR criteria for FM were used to subgroup the patients. Muscle biopsy was performed in 36 patients. Light microscope morphology and immunohistochemical expression of MHC class I, MHC class II, and membrane attack complex (MAC) were studied. RESULTS: We found 44% of patients complained of muscle pain; 27% fulfilled the ACR criteria for FM, whereas 17% had other forms of myalgia. Muscle pain could not be related to histopathological findings. Signs of inflammation were found in 26 of 36 biopsies (72%), and inflammation combined with degeneration/regeneration (i.e., histological signs of polymyositis) in 17 biopsies (47%). However, only 5 patients (14%) had clinical as well as histological signs of polymyositis. Eight muscle biopsies (22%) showed histological features of inclusion body myositis (IBM). However, no patient had clinical symptoms suggestive of this disease. Abnormal expression of MHC class I, MHC class II, and MAC was found in 18 (50%), 16 (44%), and 27 (75%) patients, respectively. CONCLUSION: Muscle pain, especially FM, is common in SS. Histopathological signs of myositis are very common in SS. However, muscle symptoms are not related to histological signs of muscle inflammation. IBM-like findings may represent vacuolar myopathic degeneration due to previous subclinical muscle inflammation rather than a specific clinical entity.

Adult↗