Biomedical subjects

Sanna Rosengren

Publications and source records attributed to Sanna Rosengren.

10 recordsLinked to original sources

PubMed2006

Real-time quantitative PCR to detect changes in synovial gene expression in rheumatoid arthritis after corticosteroid treatment.

Synovial biomarkers are increasingly important in the development of novel therapeutic agents for the treatment of rheumatoid arthritis (RA). To identify biomarkers correlating with changes in clinical disease activity, real-time quantitative PCR (Q-PCR) was used to evaluate changes in synovial gene expression after treatment with corticosteroids. Patients with active RA received either oral prednisolone (n=10, 60 mg daily for the first week and 40 mg daily for the second week) or placebo (n=11) for 14 days. Real-time Q-PCR was used to quantify gene expression of tumour necrosis factor (TNF)alpha, IL1beta, IL8 and matrix metalloproteinase (MMP) 1 in synovial tissue samples obtained through an arthroscopic procedure before and after treatment. mRNA levels were reported as relative expression units compared with a cell-based standard. Statistical analysis was performed using an analysis of covariance model. Prednisolone markedly decreased IL8 and MMP1 expression compared with placebo, and the CIs excluded the likelihood of no effect. A trend towards reduction was seen in IL1beta and TNFalpha mRNA expression in the prednisolone group, although CIs included the value for no effect. These data suggest that Q-PCR can be used to measure synovial mRNA expression of mediators implicated in the pathogenesis of RA in small proof-of-concept trials.

Adult↗

PubMed2006

PUMA regulation and proapoptotic effects in fibroblast-like synoviocytes.

OBJECTIVE: Although p53 is overexpressed in rheumatoid arthritis (RA) synovial tissue (ST), few synoviocytes undergo apoptosis. This could be partly due to low expression of proapoptotic genes. Deficient p53 up-regulated modulator of apoptosis (PUMA), which is a major effector of p53-mediated cell death, could contribute to this phenomenon. To evaluate a method to induce apoptosis, the expression and function of PUMA was investigated in ST and cultured fibroblast-like synoviocytes (FLS). METHODS: PUMA expression in ST was measured by immunohistochemistry, Western blot analysis, and quantitative polymerase chain reaction analysis. Ad-p53 and plasmids encoding hemagglutinin-tagged, full-length PUMA expression vector (HA-PUMA), PUMA lacking the Bcl-2 homology 3 domain, or pCEP4 were used to transfect FLS. Apoptosis was quantified by trypan blue exclusion, DNA fragmentation, and caspase 3 activation. RESULTS: PUMA protein was detected in RA ST, although most of the immunoreactive protein was localized to sublining cells rather than the intimal lining synoviocytes. Western blot analysis showed no difference between RA ST and osteoarthritis (OA) ST. PUMA messenger RNA was detected in RA and OA ST, although the amounts were markedly lower than in the spleen and FLS. To determine if PUMA was inducible, FLS were transduced with Ad-p53. Even though p53 protein was produced and p21 expression was increased, PUMA expression was not enhanced. Consistent with this observation, Ad-p53 did not induce apoptosis in FLS. However, HA-PUMA transfection into FLS resulted in rapid apoptosis with the activation of caspase 3. CONCLUSION: PUMA can induce apoptosis by FLS and represents a potential target in RA.

Apoptosis↗

PubMed2006

Regulation of peripheral inflammation by spinal p38 MAP kinase in rats.

BACKGROUND: Somatic afferent input to the spinal cord from a peripheral inflammatory site can modulate the peripheral response. However, the intracellular signaling mechanisms in the spinal cord that regulate this linkage have not been defined. Previous studies suggest spinal cord p38 mitogen-activated protein (MAP) kinase and cytokines participate in nociceptive behavior. We therefore determined whether these pathways also regulate peripheral inflammation in rat adjuvant arthritis, which is a model of rheumatoid arthritis. METHODS AND FINDINGS: Selective blockade of spinal cord p38 MAP kinase by administering the p38 inhibitor SB203580 via intrathecal (IT) catheters in rats with adjuvant arthritis markedly suppressed paw swelling, inhibited synovial inflammation, and decreased radiographic evidence of joint destruction. The same dose of SB203580 delivered systemically had no effect, indicating that the effect was mediated by local concentrations in the neural compartment. Evaluation of articular gene expression by quantitative real-time PCR showed that spinal p38 inhibition markedly decreased synovial interleukin-1 and -6 and matrix metalloproteinase (MMP3) gene expression. Activation of p38 required tumor necrosis factor alpha (TNFalpha) in the nervous system because IT etanercept (a TNF inhibitor) given during adjuvant arthritis blocked spinal p38 phosphorylation and reduced clinical signs of adjuvant arthritis. CONCLUSIONS: These data suggest that peripheral inflammation is sensed by the central nervous system (CNS), which subsequently activates stress-induced kinases in the spinal cord via a TNFalpha-dependent mechanism. Intracellular p38 MAP kinase signaling processes this information and profoundly modulates somatic inflammatory responses. Characterization of this mechanism could have clinical and basic research implications by supporting development of new treatments for arthritis and clarifying how the CNS regulates peripheral immune responses.

Animals↗

PubMed2005

Regulation of arthritis by p53: critical role of adaptive immunity.

OBJECTIVE: The p53 tumor-suppressor protein is expressed in rheumatoid arthritis synovium, and loss of p53 function through somatic mutation can occur in longstanding disease. Previous studies demonstrated that p53 is protective in murine collagen-induced arthritis (CIA). To determine if adaptive immune responses or synovial effector functions are responsible for this effect, passive models of arthritis were studied in p53 wild-type and knockout mice. METHODS: Models of passive CIA, passive K/BxN serum transfer arthritis, and active CIA were induced in DBA/1 p53(-/-) or p53(+) mice. Hind paws were evaluated for histologic evidence of inflammation and joint destruction. Synovial interleukin-6 and matrix metalloproteinases 3 and 13 gene expression was analyzed by real-time quantitative polymerase chain reaction. To evaluate T cell function in p53(-/-) mice, draining lymph node (LN) cells from mice immunized with type II collagen (CII) were evaluated in vitro. RESULTS: Increased disease severity in p53(-/-) mice was confirmed in the standard CIA model. However, clinical arthritis, joint destruction, and synovial gene expression in the passive CIA and K/BxN serum transfer arthritis models were similar in p53(-/-) and p53(+) mice. To determine if the p53 effect was related to T cell function, LN cells from CII-immunized mice were isolated and stimulated with antigen in vitro. CII-stimulated T cell proliferation and interferon-gamma production were significantly higher in p53(-/-) mice. An independent assessment of Th1 function using the cutaneous delayed-type hypersensitivity model confirmed that p53(-/-) mice have enhanced T cell responses in vivo. CONCLUSION: Adaptive immune responses, rather than antibody-mediated responses, in p53(-/-) mice account for increased disease severity in the active CIA model.

Animals↗

PubMed2004

Structural, expression, and evolutionary analysis of mouse CIAS1.

Mutations in the human CIAS1 (hCIAS1) gene have been identified in a continuum of inflammatory disorders including familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS), and neonatal onset multisystem inflammatory disease (NOMID). CIAS1 codes for the protein Cryopyrin, which appears to play a role in innate immune function by regulating the production of proinflammatory cytokines. Human and mouse Cryopyrin are highly conserved and consist of three functional domains including a pyrin domain, an NACHT domain, and a leucine-rich repeat (LRR) domain that are characteristics of the NALP family of proteins. The pyrin and NACHT domains of Cryopyrin and other NALP proteins are highly conserved among primate and nonprimate mammals, suggesting purifying selection throughout mammalian evolution. Cryopyrin expression is also very similar in human and mouse with mouse CIAS1 mRNA expression found primarily in peripheral blood leukocytes consistent with the postulated inflammatory function. We also detected significant expression in mouse eye and skin tissue, which is consistent with symptoms observed in human Cryopyrin-associated diseases.

Amino Acid Sequence↗

PubMed2003

Adenosine kinase inhibitors. 3. Synthesis, SAR, and antiinflammatory activity of a series of l-lyxofuranosyl nucleosides.

Chronic inflammatory diseases, such as arthritis and rheumatoid arthritis, remain major health problems worldwide. We previously demonstrated that adenosine kinase inhibitors (AKIs) exhibit antiinflammatory effects by inhibiting TNF-alpha production, neutrophil accumulation, and edema formation. Although adenosine receptor agonists produce similar effects, AKIs showed the antiinflammatory activity without the cardiovascular side effects that prevented the development of adenosine receptor specific agonists. However, previously described potent AKIs, such as 5-iodotubercidin, are nucleosides which have the potential to undergo in vivo 5'-O-phosphorylation and therefore produce cytotoxicity. In an effort to eliminate toxicities produced by phosphorylated nucleosides, l-lyxofuranosyl analogues of tubercidin were tested as potential AKIs since the opposite stereochemical orientation of the CH(2)OH was expected to eliminate intracellular phosphorylation. Described herein are the discovery of a new series of AKIs based on alpha-l-lyxofuranosyl nucleosides, their SAR, as well as the antiinflammatory activity of the lead compound GP790 (IC(50) = 0.47 nM, 47% inhibition of paw swelling at 10 mg/kg in rat carrageenan paw edema model). In addition, a study showing that in the skin lesion model the antiinflammatory activity is reversed by an A2 selective adenosine receptor antagonist 3,7-dimethyl-1-propargyl xanthine [correction of propylxanthine] (DMPX) is also described.

Adenosine Kinase↗

PubMed2003

Quantitative biomarker analysis of synovial gene expression by real-time PCR.

Synovial biomarker analysis in rheumatoid arthritis can be used to evaluate drug effect in clinical trials of novel therapeutic agents. Previous studies of synovial gene expression for these studies have mainly relied on histological methods including immunohistochemistry and in situ hybridization. To increase the reliability of mRNA measurements on small synovial tissue samples, we developed and validated real time quantitative PCR (Q-PCR) methods on biopsy specimens. RNA was isolated from synovial tissue and cDNA was prepared. Cell-based standards were prepared from mitogen-stimulated peripheral blood mononuclear cells. Real time PCR was performed using TaqMan chemistry to quantify gene expression relative to the cell-based standard. Application of the cellular standard curve method markedly reduced intra- and inter-assay variability and corrected amplification efficiency errors compared with the C(t) method. The inter-assay coefficient of variation was less than 25% over time. Q-PCR methods were validated by demonstrating increased expression of IL-1beta and IL-6 expression in rheumatoid arthritis synovial samples compared with osteoarthritis synovium. Based on determinations of sampling error and coefficient of variation, twofold differences in gene expression in serial biopsies can be detected by assaying approximately six synovial tissue biopsies from 8 to 10 patients. These data indicate that Q-PCR is a reliable method for determining relative gene expression in small synovial tissue specimens. The technique can potentially be used in serial biopsy studies to provide insights into mechanism of action and therapeutic effect of new anti-inflammatory agents.

Anti-Inflammatory Agents↗

PubMed2003

Measurement of inflammatory biomarkers in synovial tissue extracts by enzyme-linked immunosorbent assay.

We developed methods for measuring inflammatory biomarkers (cytokines, chemokines, and metalloproteinases) in synovial biopsy specimens from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Soluble extracts of synovial fragments were prepared with mild detergent and analyzed by enzyme-linked immunosorbent assay (ELISA) for interleukin 1beta (IL-1beta), IL-6, IL-8, tumor necrosis factor alpha (TNF-alpha), and matrix metalloproteinase 3. The optimal detergent was 0.1% Igepal CA-630, which interfered minimally with ELISA detection but extracted 80% of IL-6 from synovial tissue. Upon spiking, 81 to 107% of added biomarkers could be recovered. To determine within-tissue variability, multiple biopsy specimens from each RA synovial extract were analyzed individually. A resulting coefficient of variation of 35 to 62% indicated that six biopsy specimens per synovial extract would result in a sampling error of < or = 25%. Preliminary power analysis suggested that 8 to 15 patients per group would suffice to observe a threefold difference before and after treatment in a serial biopsy clinical study. The previously described significant differences in IL-1beta, IL-6, IL-8, and TNF-alpha levels between RA and OA could be detected, thereby validating the use of synovial extracts for biomarker analysis in arthritis. These methods allow monitoring of biomarker protein levels in synovial tissue and could potentially be applied to early-phase clinical trials to provide a preliminary estimate of drug efficacy.

Arthritis, Rheumatoid↗

PubMed2002

Regional analysis of p53 mutations in rheumatoid arthritis synovium.

The p53 tumor suppressor protein plays a central role in cell cycle regulation, DNA repair, and apoptosis. Recent studies indicate that DNA damage and somatic mutations in the p53 gene can occur because of genotoxic stress in many tissues, including the skin, colon, and synovium. Although somatic mutations in the p53 gene have been demonstrated in rheumatoid arthritis (RA) synovial tissue and synoviocytes, no information is available on the location or extent of p53 mutations. Using microdissected RA synovial tissue sections, we observed abundant p53 transition mutations, which are characteristic DNA damage caused by oxidative stress. p53 mutations, as well as p53 mRNA expression, were located mainly in the synovial intimal lining rather than the sublining (P < 0.01). Clusters of p53 mutant subclones were observed in some microdissected regions, suggesting oligoclonal expansion. Because IL-6 gene expression is regulated by wild-type p53, IL-6 mRNA expression in microdissected tissues was quantified by using real-time PCR. The regions with high rates of p53 mutations contained significantly greater amounts of IL-6 mRNA compared with the low mutation samples (P < 0.02). The microdissection findings suggest that p53 mutations are induced in RA synovial tissues by inflammatory oxidative stress. This process, as in sun-exposed skin and inflamed colonic epithelium, provides some of the mutant clones with a selective growth advantage. A relatively low percentage of cells containing p53 mutations can potentially affect neighboring cells and enhance inflammation through the elaboration of proinflammatory cytokines.

Arthritis, Rheumatoid↗

PubMedDate not supplied

Prevention of cold-associated acute inflammation in familial cold autoinflammatory syndrome by interleukin-1 receptor antagonist.

BACKGROUND: Familial cold autoinflammatory syndrome (FCAS) is an autosomal dominant disorder characterised by recurrent episodes of rash, arthralgia, and fever after cold exposure. The genetic basis of this disease has been elucidated. Cryopyrin, the protein that is altered in FCAS, is one of the adaptor proteins that activate caspase 1, resulting in release of interleukin 1. METHODS: An experimental cold challenge protocol was developed to study the acute inflammatory mechanisms occurring after a general cold exposure in FCAS patients and to investigate the effects of pretreatment with an antagonist of interleukin 1 receptor (IL-1Ra). ELISA, real-time PCR, and immunohistochemistry were used to measure cytokine responses. FINDINGS: After cold challenge, untreated patients with FCAS developed rash, fever, and arthralgias within 1-4 h. Significant increases in serum concentrations of interleukin 6 and white-blood-cell counts were seen 4-8 h after cold challenge. Serum concentrations of interleukin 1 and cytokine mRNA in peripheral-blood leucocytes were not raised, but amounts of interleukin 1 protein and mRNA were high in affected skin. IL-1Ra administered before cold challenge blocked symptoms and increases in white-blood-cell counts and serum interleukin 6. INTERPRETATION: The ability of IL-1Ra to prevent the clinical features and haematological and biochemical changes in patients with FCAS indicates a central role for interleukin 1beta in this disorder. Involvement of cryopyrin in activation of caspase 1 and NF-kappaB signalling suggests that it might have a role in many chronic inflammatory diseases. RELEVANCE TO PRACTICE: These findings support a new therapy for a disorder with no previously known acceptable treatment. They also offer insights into the role of interleukin 1beta in more common inflammatory diseases.

Acute Disease↗