Validation of a new fluidic device for mechanical stimulation and characterization of microspheres: A first step towards cartilage characterization

Articular cartilage is made of chondrocytes surrounded by their extracellular matrix that can both sense and respond to various mechanical stimuli. One of the most widely used in vitro model to study cartilage growth is the model of mesenchymal stromal cells-derived cartilage micropellet. However, mechanical stimulation of micropellets has never been reported probably because of their small size and imperfect round shape. The objective of the study was to develop an original custom-made device allowing both the mechanical stimulation and characterization of cartilage micropellets. The fluidic-based device was designed for the concomitant stimulation or characterization of six microspheres placed into the conical wells of a tank. In the present study, the device was validated using alginate-, collagen- and crosslinked collagen-based microspheres. Different types and ranges of pressure signals (square, sinusoidal and constant) were applied. The mechanical properties of microspheres were equivalent to those determined by a conventional compression test. Accuracy, repeatability and reproducibility of all types of pressure signals were demonstrated even though square signals were less accurate and sinusoidal signals were less reproducible than the others. The interest of this new device lies in the reliability to mechanically stimulate and characterize microspheres with diameters in the range of 900 to 1500 μm. Mechanical stimulation can be performed on six microspheres in parallel allowing the mechanical and molecular characterization of the same group of cartilage micropellets. The device will be useful to evaluate the growth of cartilage micropellets under mechanical stimuli.

Mesenchymal stem cells-derived cartilage micropellets: A relevant in vitro model for biomechanical and mechanobiological studies of cartilage growth

The prevalence of diseases that affect the articular cartilage is increasing due to population ageing, but the current treatments are only palliative. One innovative approach to repair cartilage defects is tissue engineering and the use of mesenchymal stem/stromal cells (MSCs). Although the combination of MSCs with biocompatible scaffolds has been extensively investigated, no product is commercially available yet. This could be explained by the lack of mechanical stimulation during in vitro culture and the absence of proper and stable cartilage matrix formation, leading to poor integration after implantation. The objective of the present study was to investigate the biomechanical behaviour of MSC differentiation in micropellets, a well-defined 3D in vitro model of cartilage differentiation and growth, in view of tissue engineering applications. MSC micropellet chondrogenic differentiation was induced by exposure to TGFβ3. At different time points during differentiation (35 days of culture), their global mechanical properties were assessed using a very sensitive compression device coupled to an identification procedure based on a finite element parametric model. Micropellets displayed both a non-linear strain-induced stiffening behaviour and a dissipative behaviour that increased from day 14 to day 29, with a maximum instantaneous Young's modulus of 179.9 ± 18.8 kPa. Moreover, chondrocyte gene expression levels were strongly correlated with the observed mechanical properties. This study indicates that cartilage micropellets display the biochemical and biomechanical characteristics required for investigating and recapitulating the different stages of cartilage development.

TGFβi is involved in the chondrogenic differentiation of mesenchymal stem cells and is dysregulated in osteoarthritis

OBJECTIVE

Transforming growth factor-β (TGFβ) is a major regulator of cartilage homeostasis and its deregulation has been associated with osteoarthritis (OA). Deregulation of the TGFβ pathway in mesenchymal stem cells (MSCs) has been proposed to be at the onset of OA. Using a secretome analysis, we identified a member of the TGFβ family, TGFβ-induced protein (TGFβi or βIGH3), expressed in MSCs and we investigated its function and regulation during OA.

DESIGN

Cartilage, bone, synovium, infrapatellar fat pad and bone marrow-MSCs were isolated from patients with OA or healthy subjects. Chondrogenesis of BM-MSCs was induced by TGFβ3 in micropellet culture. Expression of TGFβi was quantified by RT-qPCR, ELISA or immunohistochemistry. Role of TGFβi was investigated in gain and loss of function experiments in BM-MSCs and chondrocytes.

RESULTS

TGFβi was up-regulated in early stages of chondrogenesis and its knock-down in BM-MSCs resulted in the down-regulation of mature and hypertrophic chondrocyte markers. It likely occurred through the modulation of adhesion molecules including integrin (ITG)β1, ITGβ5 and N-cadherin. We also showed that TGFβi was upregulated in vitro in a model of OA chondrocytes, and its silencing enhanced the hypertrophic marker type X collagen. In addition, TGFβi was up-regulated in bone and cartilage from OA patients while its expression was reduced in BM-MSCs. Similar findings were observed in a murine model of OA.

CONCLUSIONS

Our results revealed a dual role of TGFβi during chondrogenesis and pointed its deregulation in OA joint tissues. Modulating TGFβi in BM-MSCs might be of interest in cartilage regenerative medicine.

Modular bioink for 3D printing of biocompatible hydrogels: sol–gel polymerization of hybrid peptides and polymers

Inorganic polymerization as a cross-linking method for 3D printing of PEG–peptide hydrogels.

PPARβ/δ directs the therapeutic potential of mesenchymal stem cells in arthritis

OBJECTIVES

To define how peroxisome proliferator-activated receptor (PPAR) β/δ expression level in mesenchymal stem cells (MSCs) could predict and direct both their immunosuppressive and therapeutic properties. PPARβ/δ interacts with factors such as nuclear factor-kappa B (NF-κB) and regulates the expression of molecules including vascular cell adhesion molecule (VCAM)-1 and intercellular adhesion molecule (ICAM)-1. Since these molecules are critical for MSC function, we investigated the role of PPARβ/δ on MSC immunosuppressive properties.

METHODS

We either treated human MSCs (hMSCs) with the irreversible PPARβ/δ antagonist (GSK3787) or derived MSCs from mice deficient for PPARβ/δ (PPARβ/δ^-/- MSCs). We used the collagen-induced arthritis (CIA) as model of immune-mediated disorder and the MSC-immune cell coculture assays.

RESULTS

Modulation of PPARβ/δ expression in hMSCs either using GSK3787 or hMSCs from different origin reveals that MSC immunosuppressive potential is inversely correlated with Ppard expression. This was consistent with the higher capacity of PPARβ/δ^-/- MSCs to inhibit both the proliferation of T lymphocytes, in vitro, and arthritic development and progression in CIA compared with PPARβ/δ^+/+ MSCs. When primed with proinflammatory cytokines to exhibit an immunoregulatory phenotype, PPARβ/δ^-/- MSCs expressed a higher level of mediators of MSC immunosuppression including VCAM-1, ICAM-1 and nitric oxide (NO) than PPARβ/δ^+/+ MSCs. The enhanced NO₂ production by PPARβ/δ^-/- MSCs was due to the increased retention of NF-κB p65 subunit on the κB elements of the inducible nitric oxide synthase promoter resulting from PPARβ/δ silencing.

CONCLUSIONS

Our study is the first to show that the inhibition or knockdown of PPARβ/δ in MSCs primes their immunoregulatory functions. Thus, the regulation of PPARβ/δ expression provides a new strategy to generate therapeutic MSCs with a stable regulatory phenotype.

Lack of anti-inflammatory and anti-catabolic effects on basal inflamed osteoarthritic chondrocytes or synoviocytes by adipose stem cell-conditioned medium

OBJECTIVE

To define whether good manufacturing practice (GMP)-clinical grade adipose stem cell (ASC)-derived conditioned medium (CM) is as effective as GMP-ASC in modulating inflammatory and catabolic factors released by both osteoarthritis (OA) chondrocytes or synoviocytes.

METHODS

OA chondrocytes and synoviocytes were treated with ASC-CM or co-cultured with ASC. Inflammatory factors (IL6, CXCL1/GROα,CXCL8/IL8, CCL2/MCP-1, CCL3/MIP-1α and CCL5/RANTES) and proteinases, such as metalloproteinase (MMP13), a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS4, ADAMTS5) and their tissue metalloproteinase inhibitors (TIMP1, TIMP3) were evaluated by qRT-PCR or immunoassays. The involvement of prostaglandin E2 (PGE2) was also analyzed.

RESULTS

Most ASC-CM ratios tested did not decrease IL6, CCL2/MCP-1, CCL3/MIP1-α, CCL5/RANTES on basal inflamed chondrocytes or synoviocytes in contrast to what we found using ASC in co-culture. CXCL8/IL8 and CXCL1/GROα were not decreased by ASC-CM on synoviocytes but were only partially reduced on chondrocytes. Moreover, ASC-CM was less efficient both on basal inflamed OA chondrocytes and synoviocytes in reducing proteinases, such as MMP13, ADAMTS4, ADAMTS5 and increasing TIMP1 and TIMP3 compared to ASC in co-culture. The different ratios of ASC-CM contain lower amounts of PGE2 which were not sufficient to reduce inflammatory factors.

CONCLUSIONS

These data show that ASC-CM has a limited ability to decrease inflammatory and proteinases factors produced by OA chondrocytes or synoviocytes. ASC-CM is not sufficient to recapitulate the beneficial effect demonstrated using ASC in co-culture with inflamed OA chondrocytes and synoviocytes and shows that their use in clinical trials is fundamental to counteract OA progression.

Mesenchymal stem cells for the management of inflammation in osteoarthritis: state of the art and perspectives

Osteoarthritis (OA) is the most common form of degenerative arthritis, mainly characterized by the degradation of articular cartilage and associated with subchondral bone lesions. Novel therapeutic approaches for OA include cell-based therapies that have become thriving areas of research and development. In this context, mesenchymal stem or stromal cells (MSCs) have gained much interest based on their trophic and immunomodulatory properties that can help tissue repair/regeneration. The present review article discusses the interest of using MSCs in cell-therapy approaches with a focus on the mechanisms by which MSCs might exhibit a therapeutic potential in OA. Special attention is given to the anti-inflammatory function of MSCs and on miRNA modulation in OA for possible future innovative strategies. The paper also presents the current data on the undergoing MSCs-based clinical trials in OA.

Glucocorticoid-induced leucine zipper governs the therapeutic potential of mesenchymal stem cells by inducing a switch from pathogenic to regulatory Th17 cells in a mouse model of collagen-induced arthritis

OBJECTIVE

Mesenchymal stem cells (MSCs) are potent immunosuppressive cells that have shown promise in the treatment of rheumatoid arthritis (RA). Deciphering the intrinsic characteristics of MSCs that correlate with their biologic activity will facilitate their clinical use. Recently, the role of glucocorticoid-induced leucine zipper (GILZ) in the development of RA has been documented. The aim of this study was to evaluate whether GILZ expression by MSCs may contribute to their therapeutic effect.

METHODS

MSCs were isolated from GILZ-deficient (GILZ(-/-) ) mice and wild-type mice. MSCs (1 × 10(6) cells) were injected twice via the tail vein into mice with collagen-induced arthritis (CIA).

RESULTS

In vitro, we showed that GILZ is a key factor involved in the immunosuppressive potential of MSCs. MSCs derived from GILZ(-/-) mice did not suppress the proliferation of CD4+ T cells and were less efficient than MSCs derived from WT mice in altering Th17 cell polarization. Thus, we investigated the role of GILZ in an experimental model of arthritis and demonstrated that although WT MSCs significantly reduced paw swelling in arthritic mice, GILZ(-/-) MSCs did not. Moreover, the magnitude of the effects of GILZ(-/-) MSCs on Th17 cell frequency was significantly lower than that of WT MSCs. The therapeutic effect of MSCs correlated with the generation of Treg cells bearing the CD4 + RORγt+IL-17(low) IL-10+ signature, and Th17 cell polarization was GILZ dependent.

CONCLUSION

This study demonstrates that GILZ has an essential role in the therapeutic effectiveness of MSCs in arthritis by favoring Th17 cell polarization toward a regulatory phenotype. Therefore, potentiation of GILZ expression in MSCs could represent a means to enhance their therapeutic effect in autoimmune diseases.

Induction of mesenchymal stem cell differentiation and cartilage formation by cross-linker-free collagen microspheres

Because of poor self-healing ability, joint cartilage can undergo irreversible degradation in the course of various diseases or after injury. A promising approach for cartilage engineering consists of using of mesenchymal stem cells (MSC) and a differentiation factor combined with an injectable carrier biomaterial. We describe here a novel synthesis route for native collagen microspheres that does not involve the use of potentially toxic crosslinking agents. An emulsion was formed between a type I collagen solution and perfluorinated oil, stabilised by a biocompatible triblock perfluorinated copolymer surfactant. Spherical microparticles of fibrillar collagen were formed through a sol-gel transition induced by ammonia vapours. Electron microscopy observations showed that these self-cross-linked microspheres were constituted by a gel of striated collagen fibrils. Microspheres that were loaded with transforming growth factor beta (TGF-β)3 progressively released this differentiation factor over a four weeks period. Human MSC rapidly adhered to TGF-β3-loaded microspheres and, after 21 d of culture, exhibited typical chondrocyte morphology and produced an uncalcified matrix made of the predominant cartilage components, aggrecan and type II collagen, but devoid of the hypertrophic marker type X collagen. Subcutaneous co-injection of MSC and TGF-β3-loaded microspheres in mice consistently led to the formation of a cartilage-like tissue, which was however hypertrophic, calcified and vascularised. In conclusion, we developed cross-linker free collagen microspheres that allowed chondrogenic differentiation of MSC in vitro and in vivo.

Treatment efficacy of adipose-derived stem cells in experimental osteoarthritis is driven by high synovial activation and reflected by S100A8/A9 serum levels

OBJECTIVE

Synovitis is evident in a substantial subpopulation of patients with osteoarthritis (OA) and is associated with development of pathophysiology. Recently we have shown that adipose-derived stem cells (ASC) inhibit joint destruction in collagenase-induced experimental OA (CIOA). In the current study we explored the role of synovitis and alarmins S100A8/A9 in the immunomodulatory capacity of ASCs in experimental OA.

METHOD

CIOA, characterized by synovitis, and surgical DMM (destabilization of medial meniscus) OA were treated locally with ASCs. Synovial activation, cartilage damage and osteophyte size were measured on histological sections. Cytokines in synovial washouts and serum were determined using Luminex or enzyme-linked immunosorbent assay (S100A8/A9), mRNA levels with reverse-transcriptase (RT)-qPCR.

RESULTS

Local administration of ASCs at various time-points (days 7 or 14) after DMM induction had no effect on OA pathology. At day 7 of CIOA, already 6 h after ASC injection mRNA expression of pro-inflammatory mediators S100A8/A9, interleukin-1beta (IL-1β) and KC was down-regulated in the synovium. IL-1β protein, although low, was down-regulated by ASC-treatment of CIOA. S100A8/A9 protein levels were very high at 6 and 48 h and were decreased by ASC-treatment. The protective action of ASC treatment in CIOA was only found when high synovial inflammation was present at the time of deposition which was reflected by high serum S100A8/A9 levels. Finally, successful treatment resulted in significantly lower levels of serum S100A8/A9.

CONCLUSION

Our study indicates that synovial activation rapidly drives anti-inflammatory and protective effects of intra-articularly deposited ASCs in experimental OA which is reflected by decreased S100A8/A9 levels.

Prospective study to evaluate the association between systemic sclerosis and occupational exposure and review of the literature

INTRODUCTION

Systemic sclerosis (SSc) has complex pathogenesis and likely multifactorial causes. Environmental exposures have been suggested to play a role in SSc pathogenesis, including occupational exposure to pollutants and chemicals as well as use of drugs leading to modulation of immune response. Thus, this case-control study aimed to assess: the relationship between SSc and occupational exposure; and the risk of SSc related to occupational exposure in male and female patients.

METHODS

From 2005 to 2008, 100 patients with a definite diagnosis of SSc were included in the study; 3 age, gender, and smoking habits matched controls were selected for each patient. A committee of experts evaluated blindly occupational exposure to crystalline silica, white spirit, organic solvents, ketones, welding fumes, epoxy resins, and pesticides; an occupational exposure score was calculated for all subjects. Our findings were compared with previous data in the literature.

RESULTS

Increased ORs for SSc were found for: crystalline silica (p<0.0001), white spirit (p<0.0001), aromatic solvents (p=0.0002), chlorinated solvents (p=0.014), trichlorethylene (p=0.044), ketones (p=0.002) and welding fumes (p=0.021). Elevated risk associated with high final cumulative score in SSc was observed for: crystalline silica, white spirit, chlorinated solvents, trichlorethylene, aromatic solvents, any type of solvents, ketones and welding fumes. A marked association between SSc and occupational exposure was further found for: 1) crystalline silica, chlorinated solvents, trichloroethylene, white spirit, ketones and welding fumes in male patients; and 2) white spirit, aromatic solvents, any type of solvent and ketones in female patients. Finally, we did not find an association between SSc and: 1) the use of drugs that have been speculated to play a role in SSc onset (anorexigens, pentazocine, bromocriptine, l-tryptophan); 2) implants - that are prosthesis, silicone implants, and contact lenses; and 3) dyeing hair. In the literature, SSc has been associated with occupational exposure to silica and solvents, while the association between SSc and specific organic solvents and welding fumes has been anecdotally reported.

CONCLUSION

The following occupational factors have an impact in the development of SSc: crystalline silica, white spirit, aromatic solvents, chlorinated solvents, trichlorethylene, ketones and welding fumes. The risk of SSc appears to be markedly associated with high cumulative exposure. Finally, the association between SSc and occupational exposure may be variable according to gender.

Bone-metastatic prostate carcinoma favors mesenchymal stem cell differentiation toward osteoblasts and reduces their osteoclastogenic potential

Bone homeostasis is achieved by the balance between osteoclast-dependent bone resorption and osteoblastic events involving differentiation of adult mesenchymal stem cells (MSCs). Prostate carcinoma (PC) cells display the propensity to metastasize to bone marrow where they disrupt bone homeostasis as a result of mixed osteolytic and osteoblastic lesions. The PC-dependent activation of osteoclasts represents the initial step of tumor engraftment into bone, followed by an accelerated osteoblastic activity and exaggerated bone formation. However, the interactions between PC cells and MSCs and their participation in the disease progression remain as yet unclear. In this study, we show that bone metastatic PC-3 carcinoma cells release factors that increase the expression by human (h)MSCs of several known pro-osteoblastic commitment factors, such as α5/β1 integrins, fibronectin, and osteoprotegerin. As a consequence, as shown in an osteogenesis assay, hMSCs treated with conditioned medium (C(ed) M) derived from PC-3 cells have an enhanced potential to differentiate into osteoblasts, as compared to hMSCs treated with control medium or with C(ed) M from non-metastatic 22RV1 cells. We demonstrate that FGF-9, one of the factors produced by PC-3 cells, is involved in this process. Furthermore, we show that PC-3 C(ed) M decreases the pro-osteoclastic activity of hMSCs. Altogether, these findings allow us to propose clues to understand the mechanisms by which PC favors bone synthesis by regulating MSC outcome and properties.

Phenotypic and functional characterisation of ovine mesenchymal stem cells: application to a cartilage defect model

BACKGROUND

Multipotent mesenchymal stromal cells (MSC) are of particular interest for their potential clinical use in cartilage engineering, but a consistent model is missing in large animals.

OBJECTIVE

In the absence of any detailed study reporting a complete characterisation of the mesenchymal cells isolated from sheep bone marrow, we fully characterised adherent stromal cells and developed a pre-clinical model of cartilage engineering by implantation of autologous MSC in the Merinos sheep.

METHODS

Ovine MSC (oMSC) were isolated from bone marrow, expanded and further characterised according to the recently proposed definition of the MSC. The experimental model consists of partial-thickness lesions created in the inner part of the patellae of the posterior legs. Lesions were filled with oMSC with or without chitosan, with or without transforming growth factor (TGF)beta-3, in a fibrin clot.

RESULTS

oMSC were shown to display the three main characteristics of MSC: adherence to plastic, phenotypic profile (positive for CD44, CD105, vimentin and negative for CD34 and CD45), and trilineage differentiation potential. We also report two other important functional characteristics of MSC: support of long-term haematopoiesis and immunosuppressive capacity. In vivo, 2 months after implantation the histological analysis revealed chondrocyte-like cells surrounded by a hyaline-like cartilaginous matrix that was integrated to the host cartilage when oMSC were combined with chitosan and TGFbeta-3.

CONCLUSIONS

This study provides for the first time a strong characterisation of oMSC and establishes the basis for a model of cartilage engineering in a large animal.

Peripheral parenteral nutrition in geriatric wards

Poor nutritional status significantly contributes to morbidity and mortality in elderly. Malnutrition and denutrition are amenable to interventions aimed to improve outcomes in acute conditions so that nutritional support is frequently initiated during hospitalisation. If the enteral route remains the first evidence-based choice when the gut is functional, this approach may be difficult to perform in some "geriatric" situations like delirium, agitation, coma or pulmonary congestion. In the first days of the acute condition, when the patient is still stable, an alternative to the enteral route may also be considered. Although there is no evidence that parenteral nutrition is better than enteral nutrition, the peripheral intravenous route may be of interest especially when the enteral route is contraindicated. Moreover, the technique of peripheral parenteral nutition reduces central cannulation-related complications like pneumothorax. We emphasize here the place of this alternative method for a short duration nutritional support when supplement of caloric intake is needed. We discuss indications, a practical approach, our experience and analyze the evidences for this complementary nutritional support.

Chordin is underexpressed in ovarian tumors and reduces tumor cell motility

Ovarian cancers mostly derive from the monolayer epithelium that covers the ovary. There are currently very few molecular clues to the etiology of this cancer. Bone morphogenetic proteins (BMPs) are required for follicular development and female fertility and are expressed in the ovarian surface epithelium (OSE). We previously reported the expression of human chordin (CHRD), a BMP extracellular regulator, in the ovary. Here we show that CHRD is underexpressed in epithelium ovary cancer and epithelial cancer cell lines as compared with normal tissues and OSE, respectively. Besides, we detected BMP expression in all ovarian cell lines analyzed. To determine the functional relevance of the absence of CHRD mRNA in tumors and cancer cell lines, we studied the effects of CHRD on two cancer cell lines, BG1 and PEO14. Migratory and invasive properties were greatly reduced, whereas cell adhesion to the support was enhanced. In addition, we detected chordin (Chrd) expression in OSE of rat ovaries in a pattern similar to that of BMP4. Altogether, these results suggest that CHRD could participate in regulating BMP activity in normal OSE physiology, and that its mis-expression in OSE may facilitate cancer incidence and/or progression.

Blood patch, il n'est jamais trop tard

Long lasting postural puncture headache secondary to an unintentional dural puncture (UDP) during epidural anaesthesia (EA) or following deliberate dural puncture for spinal anaesthesia, and neurological or neuroradiological examination, is becoming unusual. Placing the bevel of Tuohy needle parallel to the longitudinal axis of the dural cylinder when searching for epidural space, and in the later cases, widespread use of small diameter, atraumatic needles, have decreased both its incidence and severity. Furthermore, in the absence of any contraindication, patients suffering from such troubles are now quite systematically offered a curative epidural blood patch (EBP) whose effectiveness is documented. Authors report an original case of a fainthearted patient who underwent caesarean section under EA when she was 31-year-old, and whose disabling painful symptoms related to a UDP were successfully relieved by one EBP that she ended to accept more than seven years later. On the occasion of a short literature review, physiopathology and management are debated.

Engineering mesenchymal stem cells for immunotherapy

Allogeneic hematopoietic stem cell transplantation, after sublethal irradiation of recipient animals, is capable of inducing donor-specific tolerance facilitating subsequent organ transplantation. This approach could reintroduce tolerance in autoimmune diseases and it has been applied to treat autoimmune diseases with, however, a great susceptibility of recurrence. Mesenchymal stem cells (MSCs) present within the bone marrow could be critical to the immunosuppressive effect of the treatment. This tolerance induction may be useful in allogeneic transplantations, where low incidence of graft-versus-host disease was observed when the hematopoietic graft was coinjected with MSCs. In this paper, we discuss the use of MSCs in different therapeutic strategies either as immunosuppressive agents or genetically engineered to express molecules acting against the autoimmune process.

Paradoxical effects of tissue inhibitor of metalloproteinases 1 gene transfer in collagen-induced arthritis

OBJECTIVE

The imbalance between matrix metalloproteinases (MMPs) 1, 3, and 9 and their specific inhibitor, tissue inhibitor of metalloproteinases 1 (TIMP-1), is a critical step in cartilage injury and angiogenesis in arthritis. To explore the therapeutic potential of TIMP-1 gene transfer in erosive arthritis, the effects of an adenoviral vector (Ad-TIMP-1) were assessed in DBA/1 mice with collagen-induced arthritis (CIA).

METHODS

DBA/1 mice with CIA received an intravenous injection of replication-deficient adenovirus containing the human TIMP-1 gene or a control LacZ gene on day 28 postimmunization. The efficiency of gene transfer was determined by serum TIMP-1 detection, measurements of paw swelling, as well as radiologic and histologic examination of the paws.

RESULTS

A single administration of Ad-TIMP-1 resulted in detectable serum levels of the exogenous protein for at least 13 days. The incidence and onset of arthritis were not statistically modified after human TIMP-1 gene transfer in DBA/1 mice compared with control mice. However, the severity of inflammation was statistically significantly increased in Ad-TIMP-1-treated mice and a similar trend was observed in the histologic and radiologic scores. With regard to the mechanisms of the worsened effect in the Ad-TIMP-1-treated mice, we observed 1) higher serum levels of anti-type II collagen IgG2a, 2) a significant increase in endogenous soluble tumor necrosis factor receptor I (TNFRI) in sera, and 3) increased labeling of mouse tumor necrosis factor alpha and TNFRI within arthritic joints.

CONCLUSION

These findings show that overexpression of TIMP-1 does not prevent osteochondral injury in a mouse model of arthritis. Since MMPs have overlapping properties in terms of their roles in extracellular matrix degradation, angiogenesis, and shedding of cell surface adhesion molecules, cytokines, and cytokine receptors, the paradoxical results obtained suggest that TIMP-1 is probably not the main inhibitor to target.

Sustained systemic delivery of monoclonal antibodies by genetically modified skin fibroblasts

In vivo production and systemic delivery of therapeutic antibodies by engineered cells might advantageously replace injection of purified antibodies for treating a variety of life-threatening diseases, including cancer, acquired immunodeficiency syndrome, and autoimmune diseases. We report here that skin fibroblasts retrovirally transduced to express immunoglobulin genes can be used for sustained long-term systemic delivery of cloned antibodies in immunocompetent mice. Importantly, no anti- idiotypic response against the ectopically expressed model antibody used in this study was observed. This supports the notion that skin fibroblasts can potentially be used in antibody-based gene/cell therapy protocols without inducing any adverse immune response in treated individuals.

Immunotherapy of a viral disease by in vivo production of therapeutic monoclonal antibodies

Continuous and sustained in vivo production of monoclonal antibodies by engineered cells might render long-term antibody-based treatments cost-effective, avoid side effects associated with infusion of massive doses of antibody, and circumvent possible antiidiotypic responses against the therapeutic agent. The FrCasE retrovirus induces a lethal neurodegeneration on infection of newborn mice. We report here that implantation of cellulose sulfate capsules containing cells secreting an ectopic monoclonal antibody neutralizing FrCasE can prevent animals from developing the disease. All treated mice showed reduced or undetectable viremia in addition to a lack of the histopathological lesions characteristic of FrCasE infection. This work paves the way for a novel gene/cell antibody-based immunotherapy of a variety of severe viral and nonviral diseases.

[Evaluating radiotherapy patients' need for information: a study using a patient information booklet]

The French Radiotherapy-Oncology Society (SFRO) and the National Trade of Radiotherapists-Oncologists (SNRO) elaborated and published a patient information booklet on radiotherapy, in 1999. This present study appraises the pertinence of the form and substance of this booklet one year after its release. Eight radiotherapy centers participated in this research which evaluated 162 patients at treatment initiation. The conclusions of this study demonstrated the importance of clearly informing patients of their disease, treatment, and the secondary effects of treatment. It is essential to emphasize that 97% of the patients declared that an information booklet is a real necessity, and that the one provided by the SFRO responds to the majority of their concerns. Obtaining technical and practical knowledge resulted in a reassurance about their treatment. The most revealing result is that 87% requested direct communication about their illness, and that cancer be named by this word and not other, evasive terms. Seventy-two percent of the patients requested more information about their cancer, different treatment options, and quality of life issues in an attempt to psychologically prepare themselves to face an illness for which they have little control. Patients refuse to be passive, and claim the right to become 'partners' of the medical teams, concerning their treatment and recovery.

Antiviral activity of an intracellularly expressed single-chain antibody fragment directed against the murine leukemia virus capsid protein

We have addressed the possibility that intracellularly expressed miniantibodies directed against the viral capsid protein can be used as antiretroviral agents in gene transfer experiments. R187 is a rat monoclonal antibody that has been reported to recognize the MuLV p30gag capsid polypeptide. We report here that it also binds to the Pr65gag precursor polyprotein. R187 has been cloned and expressed in the form of a single-chain variable fragment (scFv) that shows the same binding specificity as the parental antibody. When expressed intracellularly, the R187 scFv favors the production of viral particles showing reduced infectivity. It, however, exerts no detectable protective effect against infection. This was observed both when using replication-incompetent MuLV-derived vector and replication-competent wild-type MuLV. Although the intimate mechanism of the inhibition is not clear, this work raises the possibility that gene engineering of anti-capsid protein scFvs may offer an additional lead for gene therapy of severe retrovirus-linked diseases.