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Costantino Pitzalis

Publications and source records attributed to Costantino Pitzalis.

At least 19 recordsLinked to original sources
PubMed2025

Genome-Wide Aggregated Trans Effects Analysis Identifies Genes Encoding Immune Checkpoints as Core Genes for Rheumatoid Arthritis.

OBJECTIVE: The sparse effector "omnigenic" hypothesis postulates that the polygenic effects of common single nucleotide polymorphisms (SNPs) on a typical complex trait are mediated by trans effects that coalesce on expression of a relatively sparse set of core genes. The objective of this study was to identify core genes for rheumatoid arthritis by testing for association of rheumatoid arthritis with genome-wide aggregated trans effects (GATE) scores for expression of each gene as transcript in whole blood or as circulating protein levels. METHODS: GATE scores were calculated for 5,400 cases and 453,705 non-cases of primary rheumatoid arthritis in UK Biobank participants of European ancestry. RESULTS: Testing for association with GATE scores identified 16 putative core genes for rheumatoid arthritis outside the HLA region, of which six-TP53BP1, PDCD1, TNFRSF14, LAIR1, LILRA4, and IDO1-were supported by Mendelian randomization analysis based on the marginal likelihood of the causal effect parameter. Five of these 16 genes were validated by a reported association of rheumatoid arthritis with SNPs within 200 kb of the transcription site, eight by association of the measured protein level with rheumatoid arthritis in UK Biobank, 10 by experimental perturbation in mouse models of inflammatory arthritis, and two-CTLA4 and PDCD1-by evidence that drugs targeting the gene cause or ameliorate inflammatory arthritis in humans. Fourteen of these 16 genes are in pathways affecting immunity or inflammation, and six-CD5, CTLA4, TIGIT, LAIR1, TNFRSF14, and PDCD1-encode receptors that have been characterized as immune checkpoints exploited by cancer cells to escape the immune response. CONCLUSION: These results highlight the key role of immune checkpoints in rheumatoid arthritis and identify possible therapeutic targets.

Humans↗
PubMed2007

Interleukin-18 as a potential therapeutic target in chronic autoimmune/inflammatory conditions.

Interleukin-18 (IL-18), a recently identified immunoregulatory and inflammatory cytokine, has attracted a profound interest as a potential therapeutic target in autoimmune/inflammatory disorders. In this review the authors focus on: IL-18 biology as an important link between innate and adaptive immunity; evidence of its pro-inflammatory role in several human autoimmune and chronic inflammatory disorders; and data indicating that IL-18 blockade in animal models results in prevention/amelioration of the disease process and preservation of the target tissue integrity and function. Finally, the authors analyse strategies presently under development to block IL-18 function and potential pitfalls resulting from IL-18 blockade that should be considered in ongoing/future clinical trials.

Animals↗
PubMed2006

From ubiquitous antigens to joint-specific inflammation: could local vascular permeability be the missing link?

The mechanisms underlying organ-specific autoimmune diseases are incompletely understood. In particular, it is still unclear how autoantibodies, often against ubiquitous antigens, can cause pathology preferentially in certain tissues. Recently, Binstadt and colleagues, using observations in the K/BxN murine arthritis model, suggested novel pathways underlying the site-specific localization of inflammation driven by immune complexes. In this commentary, we discuss these findings, the problems related to their general applicability and the implications for future research.

Animals↗
PubMed2006

Targeting the stromal microenvironment in chronic inflammation.

A characteristic feature of chronic inflammatory reactions is their persistence and predilection for certain sites. The molecular basis for such tissue tropism (as, for example, seen with metastatic spread) has until recently remained obscure, but recent studies have strongly implicated tissue-resident, stromal cells, such as macrophages, endothelial cells and fibroblasts. These cell types make attractive therapeutic targets as they help define the three-dimensional structure of tissues and are key orchestrators of the inflammatory infiltrate. Most current anti-inflammatory therapies target immune cells in an attempt to inhibit the production of pro-inflammatory mediators; however, an equally important target is the active induction of anti-inflammatory mediators involved in the resolution of inflammation. Recent work suggests that stromal cells are an important source of these mediators. Targeting of multiple signals may be required to inhibit tissue damage associated with inflammatory disease. Cells of the monocyte lineage are present as tissue-resident cells and interact closely with other stromal populations. These cells form an ideal target for modulation of the inflammatory environment as, in some cases, they appear to induce tissue repair. Therapeutic manipulation of the stromal microenvironment has been particularly effective in treating cancer and is likely to provide a novel method to achieve improved control of chronic inflammatory disease.

Angiogenic Proteins↗
PubMed2006

Mesenchymal multipotency of adult human periosteal cells demonstrated by single-cell lineage analysis.

OBJECTIVE: To investigate whether periosteal cells from adult humans have features of multipotent mesenchymal stem cells (MSCs) at the single-cell level. METHODS: Cell populations were enzymatically released from the periosteum of the proximal tibia obtained from adult human donors and then expanded in monolayer. Single-cell-derived clonal populations were obtained by limiting dilution. Culture-expanded periosteal cell populations were tested for their growth potential and for expression of conventional markers of MSCs and were subjected to in vitro assays to investigate their multilineage potential. To assess their multipotency in vivo, periosteal cells were injected into a regenerating mouse tibialis anterior muscle for skeletal myogenesis or were either seeded into an osteoinductive matrix and implanted subcutaneously into nude mice for osteogenesis or implanted in a joint surface defect under a periosteal flap into goats for chondrogenesis. Cell phenotypes were analyzed by histochemistry and immunohistochemistry and by reverse transcription-polymerase chain reaction for the expression of lineage-related marker genes. RESULTS: Regardless of donor age, periosteal cells were clonogenic and could be expanded extensively in monolayer, maintaining linear growth curves over at least 30 population doublings. They displayed long telomeres and expressed markers of MSCs. Under specific conditions, both parental and single-cell-derived clonal cell populations differentiated to the chondrocyte, osteoblast, adipocyte, and skeletal myocyte lineages in vitro and in vivo. CONCLUSION: Our study demonstrates that, regardless of donor age, the adult human periosteum contains cells that, upon enzymatic release and culture expansion, are multipotent MSCs at the single-cell level.

Adult↗
PubMed2006

Activation of WNT and BMP signaling in adult human articular cartilage following mechanical injury.

Acute full thickness joint surface defects can undergo repair, which involves tissue patterning and endochondral bone formation. Molecular signals regulating this process may contribute to the repair outcome, chronic evolution and, eventually, the onset of osteoarthritis. We tested the hypothesis that mechanical injury modulates morphogenetic pathways in adult human articular cartilage explants. Adjacent articular cartilage explants were obtained from preserved areas of the femoral condyles of patients undergoing arthroplasty for osteoarthritis, or from a normal joint of a patient undergoing lower limb amputation. Paired explants were individually maintained in explant culture. From each pair, one explant was mechanically injured and the other left uninjured as a control. Cultures were terminated at different time points for histochemistry, immunohistochemistry and gene expression analysis by reverse transcription real time PCR. Bone morphogenetic protein 2 (BMP-2) mRNA was upregulated in the injured explants. We detected phosphorylation of SMAD-1 and SMAD-5, consistent with activation of the bone morphogenetic protein (BMP) pathway. FRZB-1 mRNA was downregulated in the injured explants, suggesting de-repression of WNT signaling. Accordingly, expression of the canonical WNT target genes Axin-2 and c-JUN was upregulated in the injured explants. Activation of the canonical WNT signaling pathway by LiCl treatment induced upregulation of COL2A1 and Aggrecan mRNA, suggesting an anabolic effect. Phosphorylation of SMAD-1/-5 and downregulation of FRZB were confirmed in vivo in a mouse model of joint surface injury. Taken together, these data show modulation of the BMP and WNT pathways following mechanical injury in vitro and in vivo, which may play a role in the reparative response of the joint surface. These pathways may, therefore, represent potential targets in protocols of biological joint surface defect repair.

Aged↗
PubMed2006

Atorvastatin fails to prevent the development of autoimmune diabetes despite inhibition of pathogenic beta-cell-specific CD8 T-cells.

Statins, the widely used inhibitors of cholesterol biosynthesis, also have immunomodulatory properties. Statins have recently been shown to have beneficial prophylactic and therapeutic effects in actively induced, short-term animal models of the autoimmune diseases multiple sclerosis and rheumatoid arthritis, leading to clinical trials. We therefore investigated whether statins' protective effects could be reproduced in the nonobese diabetic (NOD) mouse, a spontaneous, chronic model of autoimmune diabetes. Mice were treated with 0, 1, 10, or 50 mg x kg(-1) x day(-1) oral atorvastatin from 6 or 12 weeks of age, without effect on the rate or prevalence of diabetes development, islet infiltration, or islet major histocompatibility complex class II expression. However, there was clear evidence of a disease-relevant immunological effect of statins in vivo, since short-term (12-day) treatment significantly reduced the number of proinflammatory (gamma-interferon-producing) CD8 cells recognizing a dominant pathogenic epitope. This effect was absent in mice treated for longer periods, suggesting that atorvastatin loses efficiency in inhibiting autoantigen-specific T-cells over time. This observation may explain the discrepancy between the reported success of statins in acutely induced models and the lack of it in a chronic, spontaneous model of autoimmune disease and has implications for the adoption of such therapy in humans.

Animals↗
PubMed2005

Involvement of subchondral bone marrow in rheumatoid arthritis: lymphoid neogenesis and in situ relationship to subchondral bone marrow osteoclast recruitment.

OBJECTIVE: To evaluate the presence and immunohistochemical characteristics of subchondral bone marrow inflammatory infiltrate in rheumatoid arthritis (RA) and to determine the in situ relationship between marrow inflammation and osteoclast recruitment. METHODS: Bone samples and paired synovia from 8 RA patients undergoing joint surgery were analyzed by immunohistochemistry and in situ hybridization for specific lymphoid neogenetic features, such as T and B cell composition, follicular dendritic cell (FDC) networks, peripheral lymph node addressin (PNAd)-positive high endothelial venules, and lymphoid chemokine expression. Osteoclasts were identified as multinucleated tartrate-resistant acid phosphatase (TRAP)-positive and cathepsin K-positive cells adherent to the bone surface. RESULTS: An inflammatory infiltrate with perivascular aggregates of variable size was detected in 7 (87.5%) of 8 synovial samples and in paired bone samples. Lymphoid neogenetic features typical of rheumatoid synovium were also recognized in the bone marrow. PNAd+ blood vessels were found in 4 of 8 patients, CD21+ FDC networks in 2 patients, CXCL13+ cells in 5 patients, and CCL21+ cells in 6 patients. TRAP-positive and cathepsin K-positive osteoclasts were identified on both the synovial and marrow sides of the bone surface. Bone marrow samples showing a higher degree of inflammation were characterized by a significantly increased number of osteoclasts adherent to the subchondral bone. CONCLUSION: Our data demonstrate that lymphoid aggregates with lymphoid neogenetic features are detectable on the subchondral side of the joint in established RA. Moreover, the local inflammation/aggregation process appears to be related to osteoclast differentiation on the marrow side of subchondral bone, supporting a functional role of the bone compartment in local damage.

Adult↗
PubMed2005

Systematic microanatomical analysis of CXCL13 and CCL21 in situ production and progressive lymphoid organization in rheumatoid synovitis.

CXCL13 and CCL21 have been functionally implicated in lymphoid tissue organization both in the upstream phases of lymphoid tissue embryogenesis and in ectopic lymphoid neogenesis in transgenic mice. Here, we analyzed the relationship between CXCL13 and CCL21 production and lymphoid tissue organization in rheumatoid synovitis as a model of a naturally occurring ectopic lymphoneogenesis. Through systematic analysis of mRNA and protein expression, we defined the microanatomical relationship between CXCL13 and CCL21 in progressive aggregational and structural phases of synovial inflammatory infiltrate. We provide the first direct in situ evidence that production of CXCL13 and CCL21 (rather than simply protein binding) is associated with inflammatory lymphoid tissue formation and development with the demonstration, in organized aggregates, of a secondary lymphoid organ-like compartmentalization and vascular association. Notably, the presence of CXCL13 and CCL21 (protein and mRNA) was also demonstrated in non-organized clusters and minor aggregational stages, providing evidence that their induction can take place independently and possibly upstream of T-B compartmentalization, CD21(+) follicular dendritic cell network differentiation and germinal center formation. Our data support the concept that, under inflammatory conditions, CXCL13 and CCL21 participate in lymphoid tissue microanatomical organization, attempting to recapitulate, in an aberrant lymphoid neogenetic process, their homeostatic and morphogenetic physiologic functions.

Arthritis, Rheumatoid↗
PubMed2005

The role of substance P in microvascular responses in murine joint inflammation.

1. Rheumatoid arthritis is a serious, inflammatory disease of the distal joints that has a possible neurogenic component underlying its pathology. 2. Substance P (SP), an endogenous neuropeptide that acts upon the neurokinin 1 (NK(1)) receptor, is released from sensory nerves and is involved in neurogenic inflammation. 3. In this study, we have developed novel techniques to determine the contribution of SP to microvascular responses in a model of complete Freund's adjuvant (CFA)-induced arthritis in NK(1) knockout mice. 4. Detailed analysis in normal mice revealed that CFA (20 microg i.art.)-induced plasma extravasation was raised from 18 to 72 h, when compared with intravascular volume. By comparison, knee swelling was sustained for 3 weeks. Neutrophil accumulation mirrored plasma extravasation. SP (10 pmol i.art.) caused significant acute plasma extravasation, but not other parameters, in wild type (WT), but not NK(1) knockout mice. CFA (10 microg i.art.) induced a significantly decreased intravascular volume, presumably due to decreased blood flow, at early time points (5 and 7 h) in WT but not NK(1) knockouts. Otherwise, similar responses in WT and NK(1) knockout mice were observed. However, injection of SP into CFA-pretreated joints caused a significant enhancement of plasma extravasation and knee swelling in the WT but not NK(1) knockouts. 5. In conclusion, the present study has used novel techniques in WT and NK(1) knockout mice to show that SP can modulate vascular tone and permeability in the inflamed joint via activation of the NK(1) receptor and that SP-induced responses are more pronounced where pre-existing inflammation is present.

Animals↗
PubMed2004

Increased circulating levels and salivary gland expression of interleukin-18 in patients with Sjögren's syndrome: relationship with autoantibody production and lymphoid organization of the periductal inflammatory infiltrate.

IL-18, an immunoregulatory and proinflammatory cytokine, has been shown to play an important pathogenic role in Th1-driven autoimmune disorders. In this study, we evaluated the circulating levels and salivary-gland expression of IL-18 in patients with Sjögren's syndrome (SS), a mainly Th1-mediated disease. IL-18 serum levels were measured by ELISA in 37 patients with primary SS, 42 with rheumatoid arthritis, and 21 normal controls. We demonstrated high IL-18 serum levels in SS, similar to those in rheumatoid arthritis patients and significantly higher than in controls (P < 0.01). In addition, IL-18 serum concentrations were significantly higher in anti-SSA/Ro+ and anti-SSB/La+ than in anti-SSA/Ro- and anti-SSB/La- SS patients (respectively, P = 0.01, P < 0.01). Serum IL-18 correlated strongly with anti-SSA/Ro (P = 0.004) and anti-SSB/La (P = 0.01) titers. Salivary gland IL-18 expression was investigated by single/double immunohistochemistry in 13 patients with primary SS and in 10 with chronic sialoadenitis, used as controls. The expression of IL-18 was also examined in periductal inflammatory foci in relation to the acquisition of features of secondary lymphoid organs such as T-B compartmentalization, formation of follicular dendritic cell networks, and presence of germinal-center-like structures. IL-18 expression in SS salivary glands was detected in 28 of 32 periductal foci of mononuclear cells (87.5%), while no IL-18 production by infiltrating cells was detected in patients with chronic sialoadenitis. Within the inflammatory foci, IL-18 immunoreactivity co-localized almost exclusively with CD68+ macrophages. In addition, IL-18 was found in 15 of 19 foci (78.9%) with no evidence of T-B cell compartmentalization (nonsegregated) but in 100% of the segregated aggregates, both in T- and B-cell-rich areas. Strikingly, IL-18 was strongly expressed by CD68+ tingible body macrophages in germinal-centre-like structures both in SS salivary glands and in normal lymph nodes. IL-18 expression was observed in the ducts of all SS biopsies but in only 4 of 10 patients with nonspecific chronic sialoadenitis (P < 0.01). This study provides the first evidence of increased circulating levels and salivary gland expression of IL-18 in SS, suggesting an important contribution of this cytokine to the modulation of immune inflammatory pathways in this condition.

Adult↗
PubMed2004

[Arthritides in the elderly].

The arthritides of the elderly comprise a fairly heterogeneous group of diseases. They include conditions that affect exclusively or predominantly the elderly (such as, for instance, remitting seronegative symmetric synovitis with pitting edema) and conditions affecting any age group, but which can present with peculiar features in the elderly, like rheumatoid arthritis and the seronegative arthropathies. Therefore, in order to arrive at a correct diagnosis, a knowledge of the specific features of these disorders is required. In addition, the treatment of elderly patients differs from that of other age groups in that elderly subjects appear to have an increased susceptibility to adverse reactions. This susceptibility is related both to the different metabolism of aged subjects, including the impairment of the renal function, and to the multiple therapies that such subjects often receive. In view of the ever increasing elderly population in the western world, all physicians, over and beyond the limited circle of rheumatologists, should be knowlegeable about the principles of diagnosing and treating senile arthritis.

Adrenal Cortex Hormones↗
PubMed2003

Isolating ligands specific for human vasculature using in vivo phage selection.

The endothelium lining blood vessels expresses molecules that are restricted in their expression to a particular tissue or organ. These molecules are attractive targets for therapy and diagnosis because they allow agents to be delivered specifically to the blood vessels supplying the desired tissue. However, it is difficult to identify these tissue-specific molecules because endothelium loses much of its tissue-specific nature when it is removed from the organ. This can be overcome by using in vivo phage selection - injecting libraries of phage bearing antibodies or peptides into an animal and isolating phage that bind to the relevant tissue. A variation on this approach, in which in vivo phage selection is performed in animals bearing human tissue xenografts, allows the isolation of peptides (and presumably other molecules) specific for human vasculature.

Animals↗
PubMed2003

Increased expression of alpha(1,3)-fucosyltransferase-VII and P-selectin binding of synovial fluid T cells in juvenile idiopathic arthritis.

OBJECTIVE: The mechanisms controlling the recruitment of T helper type 1 (Th1) cells to the inflamed synovium are not fully understood. Here, we focus on alpha(1,3)-fucosyltransferase-VII (FucT-VII), an enzyme responsible for the generation of functional P- and E-selectin ligands that is upregulated in Th1 cells. METHODS: Expression of transcripts encoding FucT-VII, interferon-gamma (IFN-gamma), and interleukin 12Rbeta2 (IL-12Rbeta2) were analyzed in T cells purified from synovial fluid (SF) and from peripheral blood (PB) of children with juvenile idiopathic arthritis (JIA) using kinetic reverse transcriptase polymerase chain reaction analysis. Binding of SF and PB T cells to P-selectin was determined by flow cytometry using a soluble P-selectin/IgG1 fusion molecule. Recruitment of T cells to synovial tissue in vivo was studied by analyzing the migration of FucT-VII transfected Jurkat T cells into human rheumatoid synovial tissue grafted into SCID mice. RESULTS: In patients with JIA, the mRNA levels of FucT-VII, as well as of IFN-gamma and IL-12Rbeta2, were up-regulated in SF T cells compared to paired PB T cells. A higher expression of FucT-VII mRNA in SF T cells was associated with increased binding of T cells to P-selectin. Moreover, FucT-VII expression and increased P-selectin binding capacity of T cells were associated with a polyarticular course of oligoarticular JIA. Expression of FucT-VII in Jurkat T cells resulted in an increased accumulation of these cells in human rheumatoid synovial tissue grafted into SCID mice. CONCLUSION: Our data indicate an important role of FucT-VII in the enhanced homing of T cells to the inflamed synovium.

Adolescent↗
PubMed2002

Annexin 1 modulates monocyte-endothelial cell interaction in vitro and cell migration in vivo in the human SCID mouse transplantation model.

The effect of the glucocorticoid inducible protein annexin 1 (ANXA1) on the process of monocytic cell migration was studied using transfected U937 cells expressing variable protein levels. An antisense (AS) (36.4AS; approximately 50% less ANXA1) and a sense (S) clone (15S; overexpressing the bioactive 24-kDa fragment) together with the empty plasmid CMV clone were obtained and compared with wild-type U937 cells in various models of cell migration in vitro and in vivo. 15S-transfected U937 cells displayed a reduced (50%) degree of trans-endothelial migration in response to stromal cell-derived factor-1alpha (CXC chemokine ligand 12 (CXCL12)). In addition, the inhibitory role of endogenous ANXA1 on U937 cell migration in vitro was confirmed by the potentiating effect of a neutralizing anti-ANXA1 serum. Importantly, overexpression of ANXA1 in clone 15S inhibited the extent of cell migration into rheumatoid synovial grafts transplanted into SCID mice. ANXA1 inhibitory effects were not due to modifications in adhesion molecule or CXCL12 receptor (CXCR4) expression as shown by the similar amounts of surface molecules found in transfected and wild-type U937 cells. Likewise, an equal chemotactic response to CXCL12 in vitro excluded an intrinsic defect in cell motility in clones 15S and 36.4AS. These data strongly support the notion that ANXA1 critically interferes with a leukocyte endothelial step essential for U937 cell, and possibly monocyte, transmigration both in vitro and in vivo.

Amino Acid Sequence↗
PubMed2002

Stromal cell-derived factor 1 (CXCL12) induces human cell migration into human lymph nodes transplanted into SCID mice.

Stromal cell-derived factor 1 (SDF-1; CXCL12), a CXC chemokine, has a primary role in signaling the recruitment of hemopoietic stem cell precursors to the bone marrow during embryonic development. In postnatal life, SDF-1 is widely expressed and is induced in chronically inflamed tissues such as psoriatic skin and the rheumatoid synovium, but has also been implicated in the migration of lymphocytes to lymphoid organs. To investigate the role of SDF-1 in recirculation and homing in vivo, we have developed a model in which human peripheral lymph nodes (huPLN) are transplanted into SCID mice. We have shown that huPLN transplants are viable, vascularized by the murine circulation that forms functional anastomoses with transplant vessels. In addition, grafts retain some features of the pretransplantation tissue, such as lymphoid follicles, lymphatic and high endothelial venule markers. We also show that SDF-1 is capable of inducing the migration of a SDF-1-responsive cell line (U937) and human PBLs from the murine circulation into the grafts in a dose-dependent manner, inhibitable by CXCR4 blockade. The mechanism of action of SDF-1 in this model is independent from that of TNF-alpha and does not rely on the up-regulation of adhesion molecules (such as ICAM-1) on the graft vascular endothelium. This is the first description of huPLN transplantation into SCID mice and of the functional effects of SDF-1 in regard to the migration of human cells into huPLN in vivo. This model provides a powerful tool to investigate the pathways involved in cell migration into lymphoid organs and potentially to target them for therapeutic purposes.

Animals↗
PubMed2002

Identification of synovium-specific homing peptides by in vivo phage display selection.

OBJECTIVE: To identify homing peptides specific for human synovium that could be used as targeting devices for delivering therapeutic/diagnostic agents to human joints. METHODS: Human synovium and skin were transplanted into SCID mice. A disulfide-constrained 7-amino acid peptide phage display library was injected intravenously into the animals and synovial homing phage recovered from synovial grafts. Following 3-4 cycles of enrichment, DNA sequencing of homing phage clones allowed the identification of specific peptides that were synthesized by a-fluorenylmethyloxycarbonyl chemistry and used in competitive in vivo assays and immunohistochemistry analyses. RESULTS: We isolated synovial homing phages displaying specific peptides that distinctively bound to synovial but not skin or mouse microvascular endothelium (MVE). They retained their tissue homing specificity in vivo, independently from the phage component, the original pathology of the transplanted tissue, and the degree of human/murine graft vascularization. One such peptide (CKSTHDRLC) maintained synovial homing specificity both when presented by the phage and as a free synthetic peptide. The synthetic peptide also competed with and inhibited in vivo the binding of the parent phage to the cognate synovial MVE ligand. CONCLUSION: This is the first report describing peptides with homing properties specific for human synovial MVE. This was demonstrated using a novel approach targeting human tissues, transplanted into SCID mice, directly by in vivo phage display selection. The identification of such peptides opens the possibility of using these sequences to construct joint-specific drug delivery systems that may have considerable impact in the treatment of arthritic conditions.

Amino Acid Sequence↗