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1.  Umbilical cord fibroblasts: Could they be considered as mesenchymal stem cells? 
World Journal of Stem Cells  2014;6(3):367-370.
In cell therapy protocols, many tissues were proposed as a source of mesenchymal stem cells (MSC) isolation. So far, bone marrow (BM) has been presented as the main source of MSC despite the invasive isolation procedure related to this source. During the last years, the umbilical cord (UC) matrix was cited in different studies as a reliable source from which long term ex vivo proliferating fibroblasts were isolated but with contradictory data about their immunophenotype, gene expression profile, and differentiation potential. Hence, an interesting question emerged: Are cells isolated from cord matrix (UC-MSC) different from other MSCs? In this review, we will summarize different studies that isolated and characterized UC-MSC. Considering BM-MSC as gold standard, we will discuss if UC-MSC fulfill different criteria that define MSC, and what remain to be done in this issue.
PMCID: PMC4131277  PMID: 25126385
Mesenchymal stem cells; Cord matrix; Bone marrow; Differentiation; Immunophenotype
2.  111Indium-oxine labelling for evaluating the homing process of autologous osteoblasts implanted percutaneously in atrophic nonunion fractures 
International Orthopaedics  2012;37(1):131-136.
The aim of the study was to control the in vivo localisation of implanted cells in cell-based therapies. Labelling cells with 111indium-oxine is one of the most interesting methods proposed. We evaluated this method in the setting of autologous osteoblast implantation in nonunion fractures.
An in vitro study of osteoblasts was conducted after 111indium-oxine labelling. Radioactivity retention and viability, proliferation and the ability to produce alkaline phosphatase were evaluated in a seven-day culture. In vivo labelling of implanted osteoblastic cells was conducted during a therapeutic trial of atrophic nonunion fractures, with the leakage outside the nonunion site and local uptake evolution at four, 24 and 48 hour being studied.
The mean labelling efficiency for osteoprogenitors was 78.8 ± 4.6 %. The intracellular retention was 89.4 ± 2.1 % at three hours and 67.3 ± 4.7 % at 18 hours. The viability assessed at three hours was 93.7 ± 0.6 %. After seven days of culture, morphology and alkaline phosphatase staining were similar for both labelled and unlabelled control cells, although the proliferation rate was decreased in the labelled cells. Some local intraosseous leakage was observed in four of 17 cases. All patients showed uptake at the injection site, with four having no other uptake. Four patients showed additional uptake in the bladder, liver and spleen, while 11 patients had additional uptake in the lungs in addition to the bladder, liver and spleen. The activity ratios (injection site/body) were 48 ± 28 % at four hours, 40 ± 25 % at 24 hours and 35 ± 25 % at 48 hours. After correcting for decay, the activity within the injection site was 82 ± 15 % at 24 hours and 69 ± 11 % at 48 hours compared with the activity measured at four hours. No relationship was found between uptake and radiological bone repair.
The 111indium-oxine labelling appears to be a good method for monitoring the behaviour of the osteoblastic cells after their implantation in atrophic nonunion fractures.
PMCID: PMC3532634  PMID: 23180104
3.  Differential Signalling Through ALK-1 and ALK-5 Regulates Leptin Expression in Mesenchymal Stem Cells 
Stem Cells and Development  2011;21(11):1948-1955.
Leptin plays a central role in maintaining energy balance, with multiple other systemic effects. Despite leptin importance in peripheral regulation of mesenchymal stem cells (MSC) differentiation, little is known about its expression mechanism. Leptin is often described as adipokine, while it is expressed by other cell types. We have recently shown an in vitro leptin expression, enhanced by glucocorticoids in synovial fibroblasts (SVF). Here, we investigated leptin expression in MSC from bone marrow (BM-MSC) and umbilical cord matrix (UMSC). Results showed that BM-MSC, but not UMSC, expressed leptin that was strongly enhanced by glucocorticoids. Transforming growth factor β1 (TGF-β1) markedly inhibited the endogenous- and glucocorticoid-induced leptin expression in BM-MSC. Since TGF-β1 was shown to signal via ALK-5-Smad2/3 and/or ALK-1-Smad1/5 pathways, we analyzed the expression of proteins from both pathways. In BM-MSC, TGF-β1 increased phosphorylated Smad2 (p-Smad2) expression, while ALK-5 inhibitor (SB431542) induced leptin expression and significantly restored TGF-β1-induced leptin inhibition. In addition, both prednisolone and SB431542 increased p-Smad1/5 expression. These results suggested the ALK-5-Smad2 pathway as an inhibitor of leptin expression, while ALK-1-Smad1/5 as an activator. Indeed, Smad1 expression silencing induced leptin expression inhibition. Furthermore, prednisolone enhanced the expression of TGF-βRII while decreasing p-Smad2 in BM-MSC and SVF but not in UMSC. In vitro differentiation revealed differential osteogenic potential in SVF, BM-MSC, and UMSC that was correlated to their leptin expression potential. Our results suggest that ALK-1/ALK-5 balance regulates leptin expression in MSC. It also underlines UMSC as leptin nonproducer MSC for cell therapy protocols where leptin expression is not suitable.
PMCID: PMC3396155  PMID: 22087763
4.  Acute-Phase Serum Amyloid A in Osteoarthritis: Regulatory Mechanism and Proinflammatory Properties 
PLoS ONE  2013;8(6):e66769.
To determine if serum amyloid A (A-SAA) could be detected in human osteoarthritic (OA) joints and further clarify if high A-SAA level in joints result from a local production or from a diffusion process from abnormally elevated plasma concentration. Regulatory mechanism of A-SAA expression and its pro-inflammatory properties were also investigated.
A-SAA levels in serum and synovial fluid of OA (n = 29) and rheumatoid arthritis (RA) (n = 27) patients were measured and compared to matched-healthy volunteers (HV) (n = 35). In vitro cell cultures were performed on primary joint cells provided from osteoarthritis patients. Regulatory mechanisms were studied using Western-blotting, ELISA and lentiviral transfections.
A-SAA was statistically increased in OA plasma patients compared to HV. Moreover, A-SAA level in OA plasma and synovial fluid increased with the Kellgren & Lauwrence grade. For all OA and RA patients, A-SAA plasma level was higher and highly correlated with its corresponding level in the synovial fluid, therefore supporting that A-SAA was mainly due to the passive diffusion process from blood into the joint cavity. However, A-SAA expression was also observed in vitro under corticosteroid treatment and/or under IL-1beta stimuli. A-SAA expression was down-regulated by PPAR-γ agonists (genistein and rosiglitazone) and up-regulated by TGF-β1 through Alk1 (Smad1/5) pathway. RhSAA induced proinflammatory cytokines (IL-6, IL-8, GRO-α and MCP-1) and metalloproteinases (MMP-1, MMP-3 and MMP-13) expression in FLS and chondrocytes, which expression was downregulated by TAK242, a specific TLR4 inhibitor.
Systemic or local A-SAA expression inside OA joint cavity may play a key role in inflammatory process seen in osteoarthritis, which could be counteracted by TLR4 inhibition.
PMCID: PMC3680431  PMID: 23776697
5.  Adalimumab alone and in combination with disease‐modifying antirheumatic drugs for the treatment of rheumatoid arthritis in clinical practice: the Research in Active Rheumatoid Arthritis (ReAct) trial 
Annals of the Rheumatic Diseases  2007;66(6):732-739.
To evaluate the safety and effectiveness of adalimumab alone or in combination with standard disease‐modifying antirheumatic drugs (DMARDs) for the treatment of rheumatoid arthritis (RA).
Patients with active RA despite treatment with DMARDs or prior treatment with a tumour necrosis factor antagonist participated in a multicentre, open‐label clinical study of adalimumab 40 mg every other week for 12 weeks with an optional extension phase. Patients were allowed to continue with pre‐existing traditional DMARDs. Long‐term safety results are reported for all patients (4210 patient‐years (PYs) of adalimumab exposure). The observed effectiveness results at week 12 are reported using American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) response criteria.
Among the 6610 treated patients, adalimumab was generally well tolerated. Serious infections occurred in 3.1% of patients (5.5/100 PYs, including active tuberculosis, 0.5/100 PYs). Demyelinating disease (0.06%) and systemic lupus erythematosus (0.03%) were rare serious adverse events. The standardised incidence ratio of malignancy was 0.71 (95% CI 0.49 to 1.01). The standardised mortality ratio was 1.07 (95% CI 0.75 to 1.49). At week 12, 69% of patients achieved an ACR20 response, 83% a moderate, and 33% a good EULAR response. Adalimumab was effective in combination with a variety of DMARDs. The addition of adalimumab to antimalarials was comparably effective to the combination of adalimumab and methotrexate.
Considering the limitations of an open‐label study, adalimumab alone or in combination with standard DMARDs appeared to be well tolerated and effective in 6610 difficult‐to‐treat patients with active RA treated in clinical practice.
PMCID: PMC1954645  PMID: 17329305
adalimumab; rheumatoid arthritis; tumour necrosis factor; monoclonal antibody; antirheumatic agents
6.  Challenges for Biomarker Discovery in Body Fluids Using SELDI-TOF-MS 
Protein profiling using SELDI-TOF-MS has gained over the past few years an increasing interest in the field of biomarker discovery. The technology presents great potential if some parameters, such as sample handling, SELDI settings, and data analysis, are strictly controlled. Practical considerations to set up a robust and sensitive strategy for biomarker discovery are presented. This paper also reviews biological fluids generally available including a description of their peculiar properties and the preanalytical challenges inherent to sample collection and storage. Finally, some new insights for biomarker identification and validation challenges are provided.
PMCID: PMC2793423  PMID: 20029632
7.  Four-year follow-up of infliximab therapy in rheumatoid arthritis patients with long-standing refractory disease: attrition and long-term evolution of disease activity 
Although there is strong evidence supporting the short-term efficacy and safety of anti-tumour necrosis factor-α agents, few studies have examined the long-term effects. We evaluated 511 patients with long-standing refractory rheumatoid arthritis treated with intravenous infusions of infliximab 3 mg/kg at weeks 0, 2, 6, and 14 and every 8 weeks thereafter for 4 years. Among the initial 511 patients included in the study, 479 could be evaluated; of these, 295 (61.6%) were still receiving infliximab treatment at year 4 of follow-up. The most common reasons for treatment discontinuation were lack of efficacy (65 patients, 13.6%), safety (81 patients, 16.9%), and elective change (38 patients, 7.9%). Analysis of disease activity scores (DAS28 [disease activity score based on the 28-joint count]) over time showed that, after the initial rapid improvement during the first 6 to 22 weeks of therapy, a further decrease in disease activity of 0.2 units in the DAS28 score per year was observed. DAS28 scores, measured at week 14 or 22, were found to predict subsequent discontinuation due to lack of efficacy. In conclusion, long-term maintenance therapy with infliximab 3 mg/kg is effective in producing further reductions in disease activity. Disease activity measured by the DAS28 at week 14 or 22 of infliximab therapy was the best predictor of long-term attrition.
PMCID: PMC1779428  PMID: 16978395
8.  DAS28 best reflects the physician's clinical judgment of response to infliximab therapy in rheumatoid arthritis patients: validation of the DAS28 score in patients under infliximab treatment 
Arthritis Research & Therapy  2005;7(5):R1063-R1071.
This study is based on an expanded access program in which 511 patients suffering from active refractory rheumatoid arthritis (RA) were treated with intravenous infusions of infliximab (3 mg/kg+methotrexate (MTX)) at weeks 0, 2, 6 and every 8 weeks thereafter. At week 22, 474 patients were still in follow-up, of whom 102 (21.5%), who were not optimally responding to treatment, received a dose increase from week 30 onward. We aimed to build a model to discriminate the decision to give a dose increase. This decision was based on the treating rheumatologist's clinical judgment and therefore can be considered as a clinical measure of insufficient response. Different single and composite measures at weeks 0, 6, 14 and 22, and their differences over time were taken into account for the model building. Ranking of the continuous variables based on areas under the curve of receiver-operating characteristic (ROC) curve analysis, displayed the momentary DAS28 (Disease Activity Score including a 28-joint count) as the most important discriminating variable. Subsequently, we proved that the response scores and the changes over time were less important than the momentary evaluations to discriminate the physician's decision. The final model we thus obtained was a model with only slightly better discriminative characteristics than the DAS28. Finally, we fitted a discriminant function using the single variables of the DAS28. This displayed similar scores and coefficients as the DAS28. In conclusion, we evaluated different variables and models to discriminate the treating rheumatologist's decision to increase the dose of infliximab (+MTX), which indicates an insufficient response to infliximab at 3 mg/kg in patients with RA. We proved that the momentary DAS28 score correlates best with this decision and demonstrated the robustness of the score and the coefficients of the DAS28 in a cohort of RA patients under infliximab therapy.
PMCID: PMC1257436  PMID: 16207323

Results 1-8 (8)