Gema Vallés - Academia.edu (original) (raw)

Papers by Gema Vallés

Figure S1. Flow cytometric determinations of the expression of surface markers in MΦGM or MΦM. Gr... more Figure S1. Flow cytometric determinations of the expression of surface markers in MΦGM or MΦM. Gray-filled histograms correspond to cells non incubated with antibodies. Figure S2. Immunomodulatory effects of primed MSC co-cultured with macrophages in the absence of LPS. (a) Scheme of the set-up of co-cultures. MΦGM or MΦM were treated with LPS, washed with PBS, and then co-cultured in fresh media with MSC primed with CM from macrophages. TNF-α and IL-10 levels in media of co-cultures of MΦGM (b) or MΦM (c). *p

Additional file 1: Figure S1. ALP activity in MSC treated for 24, 72 or 96 h with CM from MΦGM an... more Additional file 1: Figure S1. ALP activity in MSC treated for 24, 72 or 96 h with CM from MΦGM and MΦM activated (CMGM+ and CMM+, respectively) or not (CMGM- and CMM-, respectively) with LPS and further incubated in osteogenic medium (OM) for 14 days. Untreated MSC (−) were incubated in growth medium (GrM) or OM for 14 days. *p

Acetabular Revision Surgery in Major Bone Defects, 2018

Total hip arthroplasty (THA) represents the most successful and revolutionary intervention achiev... more Total hip arthroplasty (THA) represents the most successful and revolutionary intervention achieved in orthopedic surgery in the last century [1-3]. This surgery is performed to restore the injured or degenerated joint function when conservative treatment options have failed and pain, stiffness and other limitations drastically reduce the patient's quality of life. The clinical settings in which hip arthroplasty is indicated involve acute and chronic underlying joint-related diseases, mostly degenerative osteoarthritis and rheumatoid arthritis but also other arthropathies including avascular necrosis, developmental and congenital disorders, neoplasias, fractures and post-traumatic degenerative arthritis [4]. In 2010, the number of individuals bearing hip implants in USA was estimated in more than 2.5 millions [5]. In Europe, countries with high incidence are Germany, Switzerland and Belgium with ratios, of 296, 287 and 240 THA procedures per 100,000 inhabitants, respectively, while in US and UK the frequencies are 184 and 194 [3]. Early hip failure (within 5 years of implantation) is mainly associated to instability, aseptic loosening (AL), infections, wear and fracture and has a decreasing trend due to improvements in surgery techniques and advances in the biomaterials field. However, an alarming prevalence has been detected in some cohorts, especially in patients with metal-on metal (MoM) bearings [6, 7]. In the long-term, the survival rate (endpoint at revision) of prosthesis after 10-15 years of implantation has been estimated about a 90-95% [8-10] although percentages of only 58-62% or even less have been also reported after longer service periods [10-12].

Scientific Reports, 2021

The biological mechanisms involved in aseptic loosening include inflammation-associated and bone ... more The biological mechanisms involved in aseptic loosening include inflammation-associated and bone resorption-associated processes. Coordinated cellular actions result in biochemical imbalances with devastating consequences for the joint. Given that this condition is not known for showing systemic signs, we investigated whether circulating levels of inflammation-related proteins are altered in patients with aseptic loosening. Our study included 37 patients who underwent revision surgery due to hip osteolysis and aseptic loosening and 31 patients who underwent primary total hip arthroplasty. Using antibody arrays, we evaluated the serum levels of 320 proteins in four patients from each group. The results showed differences in insulin-like growth factor-binding protein 1 (IGFBP-1) concentrations, which we then quantified using enzyme-linked immunosorbent assay tests in all study patients. The results confirmed that serum IGFBP-1 concentrations were higher in the revision surgery patient...

Stem Cell Research & Therapy, 2020

Background The mechanisms by which macrophage phenotype contributes to mesenchymal stem cells (MS... more Background The mechanisms by which macrophage phenotype contributes to mesenchymal stem cells (MSC)-mediated bone repair remain unclear. In this work, we investigated the influence of factors released by human macrophages polarized to a pro-inflammatory or an anti-inflammatory phenotype on the ability of human MSC to attach, migrate, and differentiate toward the osteoblastic lineage. We focused on the role of TNF-α and IL-10, key pro-inflammatory and anti-inflammatory cytokines, respectively, in regulating MSC functions. Methods MSC were treated with media conditioned by pro-inflammatory or anti-inflammatory macrophages to study their influence in cell attachment, migration, and osteogenic differentiation. The involvement of TNF-α and IL-10 in the regulation of MSC functions was investigated using neutralizing antibodies and recombinant cytokines. Results Treatment of MSC with media conditioned by pro-inflammatory or anti-inflammatory macrophages promoted cell elongation and enhance...

Stem Cell Research & Therapy, 2019

Background: Immunoregulatory capacity of mesenchymal stem cells (MSC) is triggered by the inflamm... more Background: Immunoregulatory capacity of mesenchymal stem cells (MSC) is triggered by the inflammatory environment, which changes during tissue repair. Macrophages are essential in mediating the inflammatory response after injury and can adopt a range of functional phenotypes, exhibiting pro-inflammatory and anti-inflammatory activities. An accurate characterization of MSC activation by the inflammatory milieu is needed for improving the efficacy of regenerative therapies. In this work, we investigated the immunomodulatory functions of MSC primed with factors secreted from macrophages polarized toward a pro-inflammatory or an anti-inflammatory phenotype. We focused on the role of TNF-α and IL-10, prototypic pro-inflammatory and anti-inflammatory cytokines, respectively, as priming factors for MSC. Methods: Secretion of immunoregulatory mediators from human MSC primed with media conditioned by human macrophages polarized toward a pro-inflammatory or an anti-inflammatory phenotype was determined. Immunomodulatory potential of primed MSC on polarized macrophages was studied using indirect co-cultures. Involvement of TNF-α and IL-10 in priming MSC and of PGE 2 in MSC-mediated immunomodulation was investigated employing neutralizing antibodies. Collagen hydrogels were used to study MSC and macrophages interactions in a more physiological environment. Results: Priming MSC with media conditioned by pro-inflammatory or anti-inflammatory macrophages enhanced their immunomodulatory potential through increased PGE 2 secretion. We identified the pro-inflammatory cytokine TNF-α as a priming factor for MSC. Notably, the anti-inflammatory IL-10, mainly produced by pro-resolving macrophages, potentiated the priming effect of TNF-α. Collagen hydrogels acted as instructive microenvironments for MSC and macrophages functions and their crosstalk. Culturing macrophages on hydrogels stimulated anti-inflammatory versus pro-inflammatory cytokine secretion. Encapsulation of MSC within hydrogels increased PGE 2 secretion and potentiated immunomodulation on macrophages, attenuating macrophage pro-inflammatory state and sustaining antiinflammatory activation. Priming with inflammatory factors conferred to MSC loaded in hydrogels greater immunomodulatory potential, promoting anti-inflammatory activity of macrophages.

Scientific reports, Jan 5, 2018

A correction to this article has been published and is linked from the HTML version of this paper... more A correction to this article has been published and is linked from the HTML version of this paper. The error has been fixed in the paper.

Mediators of Inflammation, 2015

We show that galactomannan, a polysaccharide consisting of a mannose backbone with galactose side... more We show that galactomannan, a polysaccharide consisting of a mannose backbone with galactose side groups present on the cell wall of several fungi, induces a reprogramming of the inflammatory response in human macrophages through dectin-1 receptor. The nuclear factor kappa-light-chain-enhancer of activated B cells 2 (NFκB2)/p100 was overexpressed after galactomannan challenge. Knocking down NFκB2/p100 using small interfering RNA (siRNA) indicated that NFκB2/p100 expression is a crucial factor in the progression of the galactomannan-induced refractoriness. The data presented in this study could be used as a modulator of inflammatory response in clinical situations where refractory state is required.

Biomaterials, 2015

Implantation of scaffolds may elicit a host foreign body response triggered by monocyte/macrophag... more Implantation of scaffolds may elicit a host foreign body response triggered by monocyte/macrophage lineage cells. Growing evidence suggests that topographical cues of scaffolds play an important role in MSC functionality. In this work, we examined whether surface topographical features can regulate paracrine interactions that MSCs establish with macrophages. Three-dimensional (3D) topography sensing drives MSCs into a spatial arrangement that stimulates the production of the anti-inflammatory proteins PGE 2 and TSG-6. Compared to two-dimensional (2D) settings, 3D arrangement of MSCs cocultured with macrophages leads to an important decrease in the secretion of soluble factors related with inflammation and chemotaxis including IL-6 and MCP-1. Attenuation of MCP-1 secretion in 3D cocultures correlates with a decrease in the accumulation of its mRNA levels in MSCs and macrophages. Using neutralizing antibodies, we identified that the interplay between PGE 2 , IL-6, TSG-6 and MCP-1 in the co-cultures is strongly influenced by the micro-architecture that supports MSCs. Local inflammatory milieu provided by 3D-arranged MSCs in co-cultures induces a decrease in monocyte migration as compared to monolayer cells. This effect is partially mediated by reduced levels of IL-6 and MCP-1, proteins that up-regulate each other's secretion. Our findings highlight the importance of topographical cues in the soluble factor-guided communication between MSCs and macrophages.

Tribology in Total Hip Arthroplasty, 2011

... Events Near the Implant Gema Vallés, Eduardo García-Cimbrelo, and Nuria Vilaboa 15 15.1 Intro... more ... Events Near the Implant Gema Vallés, Eduardo García-Cimbrelo, and Nuria Vilaboa 15 15.1 Introduction ... 21539 43. Goodman, SB, Ma, T., Chiu, R., Ramachandran, R., Smith, RL: Effects of orthopaedic wear particles on osteoprogenitor cells. Biomaterials 27, 60966101 (2006). ...

Journal of Bone & Joint …, 2011

The biological response to implant-derived wear particles is recognized as one of the main factor... more The biological response to implant-derived wear particles is recognized as one of the main factors involved in the development of periprosthetic osteolysis. Wear particles induce a foreign-body inflammatory response that results in the formation of a ...

Journal of Orthopaedic Research, 2005

The purpose of the current study was to evaluate the effects of alumina particles on secretion of... more The purpose of the current study was to evaluate the effects of alumina particles on secretion of several cytokines involved in bone resorption in cocultures of macrophages and osteoblasts. To distinguish the contribution of each individual cell type, we have established a heterologous in vitro system that makes use of mouse J774 cells and primary cultured human osteoblasts. J744 cells decreased the production of TNF-a when they were cocultured with osteoblasts. Treatment of J744 cells with alumina particles increased TNF-a secretion, but the induction was lower when cells were cocultured with osteoblasts. Secretion of IL-6 by J744 cells was very low, and increased in the presence of osteoblasts. Alumina particles were only able to stimulate the release of IL-6 by J744 cells when cells were cocultured with osteoblasts. On the other hand, incubation of osteoblasts with alumina particles enhanced the release of IL-6 and GM-CSF. Coculturing osteoblasts with J744 cells induced them to release IL-6 and GM-CSF, and treatment with alumina further increased the secretion of both mediators by osteoblasts. According to these in vitro results, it seems rather plausible that alumina particles are able to initiate an inflammatory response in vivo.

Journal of Biomedical Materials Research Part A, 2005

We have recently reported that thermal oxidation treatments of Ti6Al4V at 500°and 700°C for 1 h r... more We have recently reported that thermal oxidation treatments of Ti6Al4V at 500°and 700°C for 1 h result in the formation of an outer "ceramic" layer of rutile that do not decrease the high in vitro corrosion resistance of the alloy. In the present work, surface roughness was measured and found marginally increased as a consequence of oxidation of the alloy at 700°C, but not at 500°C. We have evaluated the biocompatibility of the oxidized surfaces, by assessing cell adhesion, proliferation, and differentiation of primary cultures of human osteoblastic cells. Compared with polished alloy, both thermal treatments increased osteoblast adhesion measured as cell attachment, ␤ 1 integrin and FAK-Y397 expression, as well as cytoskeletal reorganization. Compared with treatment at 500°C, thermal oxidation at 700°C enhanced cell adhesion. Treatment at 700°C transiently impaired cell proliferation and viability, which were not altered in alloys oxidized at 500°C. Several markers of osteoblastic differentiation such as procollagen I peptide, alkaline phosphatase, osteocalcin, and mineralized nodule formation were found either unaffected or differentially increased by alloys treated either at 500°or 700°C. In addition, thermal oxidation at 700°C also increased osteoprotegerin secretion. Taken together, our results indicate that thermal oxidation treatments at 500°or 700°C for 1 h improve the in vitro biocompatibility of Ti6Al4V.

Journal of Biomedical Materials Research Part A, 2006

El artículo seleccionado no se encuentra disponible por ahora a texto completo por no haber sido ... more El artículo seleccionado no se encuentra disponible por ahora a texto completo por no haber sido facilitado todavía por el investigador a cargo del archivo del mismo.

Journal of Biomedical Materials Research Part A, 2007

Titanium and its alloys are widely used as implant materials for dental and orthopaedic applicati... more Titanium and its alloys are widely used as implant materials for dental and orthopaedic applications. To improve their wear and corrosion resistance, several surface modifications that give rise to an outer ceramic layer of rutile have been developed. It is expected that after a long period of functional loading, rutile debris will arise from these modified surfaces. We have compared the in vitro biocompatibility of subcytotoxic doses of rutile and titanium particles of phagocytosable size in primary cultures of human osteoblasts. Particles were visualized using a spectral confocal microscope by reflection. Both types of particles aggregated in the culture media and were efficiently internalized by osteoblasts as agglomerates. Treatment of isolated cultures of osteoblasts with rutile particles stimulated the release of IL-6, PGE 2 , and GM-CSF to a lesser extent than titanium. The influence of macrophages on the particle-induced stimulation of those local factors was analyzed by coculturing TPA-differentiated THP-1 cells with osteoblasts. Under these conditions, levels of IL-6 and PGE 2 after treatment of cocultured osteoblasts with rutile particles were lower than after exposure to titanium. These results indicate that rutile debris shows a lower bioreactivity than titanium when tested in cultures of human osteoblasts and support the improved biocompatibility of titanium-based implants modified to create an outer layer of rutile on their surfaces.

Biomaterials, 2008

Titanium (Ti) and its alloys have widespread uses as implant materials for orthopaedic and dental... more Titanium (Ti) and its alloys have widespread uses as implant materials for orthopaedic and dental applications. To improve their surface characteristics, modifications that give rise to an outer ceramic layer of rutile have been developed. It is expected that after a long period of service, rutile particles will arise from these modified surfaces. Rutile particles have recently been proposed as reinforcement agents of substrates designed for bone tissue engineering applications. In this study, the ability of Ti and rutile particles to modulate secretion of soluble factors involved in bone turnover has been assayed in an in vitro co-culture system of macrophages and human osteoblasts that allows the exchange of soluble factors between both cell types without direct cell contact. Exposure of co-cultured macrophages to sub-cytotoxic doses of Ti or rutile particles did not modify the osteoblastic expression of surface RANKL or the secretion of OPG into the media. Both IL-6 and PGE 2 levels increased to a similar extent after treatment with rutile or Ti particles. M-CSF and GM-CSF levels were lower after treatment with rutile particles than with Ti. Experiments employing neutralising antibodies indicate that exposure of co-cultured macrophages to both Ti-based particles induces the release of M-CSF, GM-CSF, IL-6 and PGE 2 through up-regulation of IL-1b and TNF-a. We comparatively examined the response of co-cultured macrophages, osteoblasts or both types of cells after exposure to particles. The results indicate that interactions of osteoblasts with particles can modulate the extent of the response initiated by macrophages. Maximal levels of secretions of all tested factors were reached after exposure of co-cultured cells to Ti particles, which is suggestive of the lower bioreactivity of rutile particles.

Biomaterials, 2002

The effect of two biomaterials, polyethylene and α-alumina, on interleukin-6 (IL-6) secretion and... more The effect of two biomaterials, polyethylene and α-alumina, on interleukin-6 (IL-6) secretion and expression has been studied in human osteoblasts in primary culture. Human osteoblastic cells were derived from fresh trabecular bone explants removed during total knee arthroplasty. On reaching confluence, cells were subcultured in 6 well plates; the resulting subcultures were incubated until confluence and polyethylene or α-alumina particles

Biochemical and Biophysical Research Communications, 2003

The exposure of human monocytes to the gram-negative endotoxin LPS provokes them to enter a trans... more The exposure of human monocytes to the gram-negative endotoxin LPS provokes them to enter a transient state in which they are refractory to further stimulation by LPS. This phenomenon is known as 'endotoxin tolerance' (ET) and it is characterized by a decrease in leukocyte proinflammatory cytokine production in response to LPS. In the present study, we have analyzed the expression of IRAK-M mRNA and protein in a human model of ET using human monocytes isolated from peripheral blood. In these monocyte cultures, IRAK-M mRNA was expressed 6 h after stimulation with different doses of LPS. However, endotoxin pretreatment induced a more immediate up-regulation of IRAK-M gene expression, transcripts appearing only one hour after a second LPS-challenge, and the production of high levels of IRAK-M protein in these tolerant monocytes. We also analyzed the response of monocytes isolated from septic patients within a temporal tolerance timeframe when stimulated ex vivo with LPS. In contrast to monocytes from healthy volunteers and patients outside of the tolerance timeframe, monocytes from septic patients rapidly expressed IRAK-M mRNA when stimulated with LPS ex vivo. Moreover, the expression of IRAK-M mRNA was more rapidly induced in the presence of a PI3K inhibitor, suggesting a connection between these two kinases. Thus, our data indicate that IRAK-M could play a pivotal role in the process of ET in human monocytes and provide evidence that PI3K is involved in regulating its expression.