Poliamines en la sang i l'intestí : estudis sobre els nivells eritrocitaris i el metabolisme en la mucosa intestinal /

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Measurement of CO3-610, a Potential Liver Biomarker Derived from Matrix Metalloproteinase-9 Degradation of Collagen Type III, in a Rat Model of Reversible Carbon-Tetrachloride-Induced Fibrosis

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A microarray analysis of full depth knee cartilage of ovariectomized rats

<p>Abstract</p> <p>Background</p> <p>This short communication focuses the on articular cartilage and the subchondral bone, both of which play important roles in the development of osteoarthritis (OA). There are indications that estrogen-deficiency, as the post-menopausal state, accelerate the development of OA.</p> <p>Findings</p> <p>We investigated, which extracellular matrix (ECM) protein, proteases and different pro-inflammatory factors was up- or down-regulated in the knee joint tissue in response to estrogen-deficiency in rats induced by ovariectomy. These data support previous findings that several metalloproteinases (MMPs) and cysteine proteases are co-regulated with numerous collagens and proteoglycans that are important for cartilage integrity. Furthermore quite a few pro-inflammatory cytokines were regulated by estrogen deprivation.</p> <p>Conclusion</p> <p>We found multiple genes where regulated in the joint by estrogen-deficiency, many of which correspond well with our current knowledge of the pathogenesis of OA. It supports that estrogen-deficiency (e.g. OVX) may accelerate joint deterioration. However, there are also data that draw attention the need for better understanding of the synergy between proteases and tissue turnover.</p

Identification of the calcitonin receptor in osteoarthritic chondrocytes

<p>Abstract</p> <p>Background</p> <p>Preclinical and clinical studies have shown that salmon calcitonin has cartilage protective effects in joint degenerative diseases, such as osteoarthritis (OA). However, the presence of the calcitonin receptor (CTR) in articular cartilage chondrocytes is yet to be identified. In this study, we sought to further investigate the expression of the CTR in naïve human OA articular chondrocytes to gain further confirmation of the existents of the CTR in articular cartilage.</p> <p>Methods</p> <p>Total RNA was purified from primary chondrocytes from articular cartilage biopsies from four OA patients undergoing total knee replacement. High quality cDNA was produced using a dedicated reverse transcription polymerase chain reaction (RT-PCR) protocol. From this a nested PCR assay amplifying the full coding region of the CTR mRNA was completed. Western blotting and immunohistochemistry were used to characterize CTR protein on protein level in chondrocytes.</p> <p>Results</p> <p>The full coding transcript of the CTR isoform 2 was identified in all four individuals. DNA sequencing revealed a number of allelic variants of the gene including two potentially novel polymorphisms: a frame shift mutation, +473del, producing a shorter form of the receptor protein, and a single nucleotide polymorphism in the 3' non coding region of the transcript, +1443 C>T. A 53 kDa protein band, consistent with non-glycosylated CTR isoform 2, was detected in chondrocytes with a similar size to that expressed in osteoclasts. Moreover the CTR was identified in the plasma membrane and the chondrocyte lacuna of both primary chondrocytes and OA cartilage section.</p> <p>Conclusions</p> <p>Human OA articular cartilage chondrocytes do indeed express the CTR, which makes the articular a pharmacological target of salmon calcitonin. In addition, the results support previous findings suggesting that calcitonin has a direct anabolic effect on articular cartilage.</p

Investigation of the direct effects of salmon calcitonin on human osteoarthritic chondrocytes

<p>Abstract</p> <p>Background</p> <p>Calcitonin has been demonstrated to have chondroprotective effects under pre-clinical settings. It is debated whether this effect is mediated through subchondral-bone, directly on cartilage or both in combination. We investigated possible direct effects of salmon calcitonin on proteoglycans and collagen-type-II synthesis in osteoarthritic (OA) cartilage.</p> <p>Methods</p> <p>Human OA cartilage explants were cultured with salmon calcitonin [100 pM-100 nM]. Direct effects of calcitonin on articular cartilage were evaluated by 1) measurement of proteoglycan synthesis by incorporation of radioactive labeled ³⁵SO₄[5 μCi] 2) quantification of collagen-type-II formation by pro-peptides of collagen type II (PIINP) ELISA, 3) QPCR expression of the calcitonin receptor in OA chondrocytes using four individual primer pairs, 4) activation of the cAMP signaling pathway by EIA and, 5) investigations of metabolic activity by AlamarBlue.</p> <p>Results</p> <p>QPCR analysis and subsequent sequencing confirmed expression of the calcitonin receptor in human chondrocytes. All doses of salmon calcitonin significantly elevated cAMP levels (P < 0.01 and P < 0.001). Calcitonin significantly and concentration-dependently [100 pM-100 nM] induced proteoglycan synthesis measured by radioactive ³⁵SO₄incorporation, with a 96% maximal induction at 10 nM (P < 0.001) corresponding to an 80% induction of 100 ng/ml IGF, (P < 0.05). In alignment with calcitonin treatments [100 pM-100 nM] resulted in 35% (P < 0.01) increased PIINP levels.</p> <p>Conclusion</p> <p>Calcitonin treatment increased proteoglycan and collagen synthesis in human OA cartilage. In addition to its well-established effect on subchondral bone, calcitonin may prove beneficial to the management of joint diseases through direct effects on chondrocytes.</p