Blocking GM-CSF receptor α with mavrilimumab reduces infiltrating cells, pro-inflammatory markers and neoangiogenesis in ex vivo cultured arteries from patients with giant cell arteritis

Effective and safe therapies are needed for the treatment of patients with giant cell arteritis (GCA). Emerging as a key cytokine in inflammation, granulocyte-macrophage colony stimulating factor (GM-CSF) may play a role in promoting inflammation in GCA.To investigate expression of GM-CSF and its receptor in arterial lesions from patients with GCA. To analyse activation of GM-CSF receptor-associated signalling pathways and expression of target genes. To evaluate the effects of blocking GM-CSF receptor α with mavrilimumab in ex vivo cultured arteries from patients with GCA.Quantitative real time PCR, in situ RNA hybridisation, immunohistochemistry, immunofluorescence and confocal microscopy, immunoassay, western blot and ex vivo temporal artery culture.GM-CSF and GM-CSF receptor α mRNA and protein were increased in GCA lesions; enhanced JAK2/STAT5A expression/phosphorylation as well as increased expression of target genes CD83 and Spi1/PU.1 were observed. Treatment of ex vivo cultured GCA arteries with mavrilimumab resulted in decreased transcripts of CD3ε, CD20, CD14 and CD16 cell markers, and reduction of infiltrating CD16 and CD3ε cells was observed by immunofluorescence. Mavrilimumab reduced expression of molecules relevant to T cell activation (human leukocyte antigen-DR [HLA-DR]) and Th1 differentiation (interferon-γ), the pro-inflammatory cytokines: interleukin 6 (IL-6), tumour necrosis factor α (TNFα) and IL-1β, as well as molecules related to vascular injury (matrix metalloprotease 9, lipid peroxidation products and inducible nitric oxide synthase [iNOS]). Mavrilimumab reduced CD34 + cells and neoangiogenesis in GCA lesions.The inhibitory effects of mavrilimumab on multiple steps in the GCA pathogenesis cascade in vitro are consistent with the clinical observation of reduced GCA flares in a phase 2 trial and support its development as a therapeutic option for patients with GCA.© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ

Antibodies against peripheral nerve antigens in chronic inflammatory demyelinating polyradiculoneuropathy

Altres ajuts: Beca Juan Rodes JR1300014Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a heterogeneous disease in which diverse autoantibodies have been described but systematic screening has never been performed. Detection of CIDP-specific antibodies may be clinically useful. We developed a screening protocol to uncover novel reactivities in CIDP. Sixty-five CIDP patients and 28 controls were included in our study. Three patients (4.6%) had antibodies against neurofascin 155, four (6.2%) against contactin-1 and one (1.5%) against the contactin-1/contactin-associated protein-1 complex. Eleven (18.6%) patients showed anti-ganglioside antibodies, and one (1.6%) antibodies against peripheral myelin protein 2. No antibodies against myelin protein zero, contactin-2/contactin-associated protein-2 complex, neuronal cell adhesion molecule, gliomedin or the voltage-gated sodium channel were detected. In IgG experiments, three patients (5.3%) showed a weak reactivity against motor neurons; 14 (24.6%) reacted against DRG neurons, four of them strongly (7.0%), and seven (12.3%) reacted against Schwann cells, three of them strongly (5.3%). In IgM experiments, six patients (10.7%) reacted against DRG neurons, while three (5.4%) reacted against Schwann cells. However, results were not statistically significant when compared to controls. Immunoprecipitation experiments identified CD9 and L1CAM as potential antigens, but reactivity could not be confirmed with cell-based assays. In summary, we describe a diverse autoantibody repertoire in CIDP patients, reinforcing the hypothesis of CIDP's pathophysiological heterogeneity

Famílies botàniques de plantes medicinals

Facultat de Farmàcia, Universitat de Barcelona. Ensenyament: Grau de Farmàcia, Assignatura: Botànica Farmacèutica, Curs: 2013-2014, Coordinadors: Joan Simon, Cèsar Blanché i Maria Bosch.Els materials que aquí es presenten són els recull de 175 treballs d’una família botànica d’interès medicinal realitzats de manera individual. Els treballs han estat realitzat per la totalitat dels estudiants dels grups M-2 i M-3 de l’assignatura Botànica Farmacèutica durant els mesos d’abril i maig del curs 2013-14. Tots els treballs s’han dut a terme a través de la plataforma de GoogleDocs i han estat tutoritzats pel professor de l’assignatura i revisats i finalment co-avaluats entre els propis estudiants. L’objectiu principal de l’activitat ha estat fomentar l’aprenentatge autònom i col·laboratiu en Botànica farmacèutica

Contribution of hypoxia inducible factor, HIF1α, to vascular inflammation and remodeling in giant cell arteritis (GCA). Effects of GM-CSF receptor blockade on HIF1α stabilization

[eng] Giant Cell Arteritis (GCA) is an immune-mediated disease affecting large and medium sized arteries. Its pathophysiology is not fully understood and its present treatment relies on glucocorticoids, which have important side effects. Therefore, studying the disease and finding new treatments is an unmet medical need. GCA lesions undergo several changes during the development of the disease. Thickening and remodeling of the vascular wall are due to the aberrant inflammatory infiltrate. These changes promote angiogenesis. Angiogenesis is one of the main consequences of hypoxia, through stabilization and induction of Hypoxia Inducible Factor 1 alpha (HIF1α). Several inflammatory molecules such as IL6, IL1β, TNFα and IFNγ, present in GCA lesions, have been demonstrated to be able to stabilize HIF1α. Moreover, several HIF1α target genes like IL6 and other proinflammatory molecules are present in GCA lesions. Moreover, vascular smooth muscle cells (VSMC) are able to express HIF1α under certain conditions. GM-CSF is an important inflammatory mediator expressed by several inflammatory and vascular resident cells. It downstream pathway includes JAK/STAT activation. Regarding GCA, GM-CSF can be affecting several important points of its pathogenesis, from initial dendritic cells activation to leucocyte recruitment and giant cell formation. Considering all these together, our hypothesis for the present thesis is as follows: HIF1⍺ and GM-CSF play an important role in vascular inflammation and remodeling in GCA, through independent or inter-related mechanisms. The objectives are to determine the presence/absence of HIF1α in GCA lesions as well as triggers and consequences of it. To analyze the effect of anti-cytokine targeted therapies in this pathway. To investigate GM-CSF pathway in GCA and the effect of its blockade with mavrilimumab. In the present thesis we demonstrate the presence of hypoxia in the GCA lesions as well as the presence of HIF1α in the media layer of GCA temporal arteries. We validate that VSMC, the cells present in the media layer of the artery, are able to stabilize HIF1α under an inflammatory microenvironment with an in-vitro model of the disease. Under this inflammatory microenvironment VSMC also increase the expression of GLUT1 and PHD3 transcripts, which are well-described HIF1α target genes indicating HIF1α functional activity in these cells. VSMC modify its transcriptome when HIF1α is stabilized affecting important pathways in GCA pathogenesis. In these cells the migratory capacity is reduced, angiogenic factors are increased (VEGFA, IL6, CXCL8), chemokine expression is imbalanced (CCL2 and CCL5 decreased and CXCL8 increased) and inflammation-relation transcripts were increased (IL6, IL1B, TNFA and CSF2). Inhibiting TNFα, IL1 and GM-CSF in an inflammatory microenvironment was able to reduce HIF1α protein levels in VSMC. GM-CSF and its receptor (GM-CSFRα) are present in GCA lesions, and its downstream pathway (JAK2/STAT5) is activated. Inhibiting GM-CSF effects with mavrilimumab, a monoclonal antibody against GM-CSF receptor alpha chain , in an ex-vivo model of the disease induced the following effects: reduction of lymphocyte and myeloid cell markers; reduction in T cell activation related molecules and Th1 differentiation pathway; decrease of pro-inflammatory cytokines; decrease of mediators of vascular injury; and reduction in tissue angiogenesis. Blocking GM-CSF receptor with mavrilimumab reduces some HIF1α targets (IL6, IL1β, and TNFα) which, including IFNγ, are also identified as stimuli for HIF1α that accumulated in VSMC, supporting the relationship between HIF1α and GM-CSF pathways in the pathogenesis of GCA.[cat] La fisiopatologia de l’arteritis de cèl·lules gegants (ACG) no es coneix amb profunditat i el tractament actual està basat en glucocorticoides amb els seus afectes adversos pel que és necessari seguir estudiant la malaltia i trobar millors teràpies. Les artèries dels pacients amb ACG experimenten un engruiximent i remodelat de la paret degut a un infiltrat inflamatori aberrant. Aquests canvis promouen angiogènesi, una de les principals conseqüències de la hipòxia, mitjançant l’HIF1α. Hi ha diverses molècules inflamatòries presents en les lesions descrites com estabilitzadores de l’HIF1α. A més a més, diverses molècules diana d’aquest factor es troben presents en les lesions. Uns del tipus cel·lulars importants en la fisiopatologia, les cèl·lules muscular llises (VSMC) poden expressar l’HIF1α i durant el desenvolupament de l’ACG adquireixen un fenotip pro-inflamatori. Tot això, fa que una hipòtesi raonable sigui que l’HIF1α té un rol important en la fisiopatologia de l’ACG i en el desenvolupament i manteniment de la inflamació en les lesions. En aquesta tesi es demostra hipòxia i la presencia d’HIF1α en les lesions d’ACG. L’HIF1α es troba principalment en la capa mitja de la paret vascular on es troben les VSMC. També es demostra que les VSMC són capaces d’estabilitzar l’HIF1α quan es troben en un microambient inflamatori; i en aquestes condicions també augmenta l’expressió dels gens diana de HIF1α. Quan estabilitzen in-vitro l’HIF1α en les VSMC aquestes canvien la seva expressió de diversos gens i proteïnes implicats en el remodelat vascular, l’angiogènesi i la quimiotaxi. Sota el microambient inflamatori, quan certes molècules pro-inflamatòries (GM-CSF, IL1β i TNFα) es troben inhibides els nivells d’HIF1α disminueixen. En concret, la inhibició del receptor del GM-CSF mitjançant l’ús del mavrilimumab, disminueix diverses molècules inflamatòries, angiogèniques i de dany vascular. Algunes d’aquestes molècules estan descrites com a inductores i alhora gens diana de l’HIF1α. En resum, es demostra que l’HIF1α juga un paper important en la fisiopatologia de l’ACG, així com el GM-CSF i que ambdós factors es troben estretament relacionats en aquesta malaltia

B55 alpha/PP2A Limits Endothelial Cell Apoptosis During Vascular Remodeling A Complementary Approach To Disrupt Pathological Vessels?

RATIONALE: How endothelial cells (ECs) migrate and form an immature vascular plexus has been extensively studied. Yet, mechanisms underlying vascular remodeling remain poorly established. A better understanding of these processes may lead to the design of novel therapeutic strategies complementary to current angiogenesis inhibitors. OBJECTIVE: Starting from our previous observations that PP2A (protein phosphatase 2) regulates the HIF (hypoxia-inducible factor)/PHD-2 (prolyl hydroxylase 2)-constituted oxygen machinery, we hypothesized that this axis could play an important role during blood vessel formation, tissue perfusion, and oxygen restoration. METHODS AND RESULTS: We show that the PP2A regulatory subunit B55α is at the crossroad between vessel pruning and vessel maturation. Blood vessels with high B55α counter cell stress conditions and thrive for stabilization and maturation. When B55α is inhibited, ECs cannot cope with cell stress and undergo apoptosis, leading to massive pruning of nascent blood vessels. Mechanistically, we found that the B55α/PP2A complex restrains PHD-2 activity, promoting EC survival in a HIF-dependent manner, and furthermore dephosphorylates p38, altogether protecting ECs against cell stress occurring, for example, during the onset of blood flow. In tumors, EC-specific B55α deficiency induces pruning of immature-like tumor blood vessels resulting in delayed tumor growth and metastasis, without affecting nonpathological vessels. Consistently, systemic administration of a pan-PP2A inhibitor disrupts vascular network formation and tumor progression in vivo without additional effects on B55α-deficient vessels. CONCLUSIONS: Our data underline a unique role of the B55α/PP2A phosphatase complex in vessel remodeling and suggest the use of PP2A-inhibitors as potent antiangiogenic drugs targeting specifically nascent blood vessels with a mode-of-action complementary to VEGF-R (vascular endothelial growth factor receptor)-targeted therapies. Graphical Abstract: A graphical abstract is available for this article.status: publishe

B55α/PP2A Limits Endothelial Cell Apoptosis During Vascular Remodeling: A Complementary Approach To Kill Pathological Vessels?

Rationale: How endothelial cells (ECs) migrate and form an immature vascular plexus has been extensively studied. Yet, mechanisms underlying vascular remodeling remain poorly established. A better understanding of these processes may lead to the design of novel therapeutic strategies complementary to current angiogenesis inhibitors. Objective: Starting from our previous observations that the PP2A phosphatase regulates the HIF/PHD2-constituted oxygen machinery, we hypothesized that this axis could play an important role during blood vessel formation, tissue perfusion and oxygen restoration. Methods and Results: We show that the regulatory PP2A-phosphatase subunit B55? is at the crossroad between vessel pruning and vessel maturation. Blood vessels with high B55? will counter cell stress conditions and thrive for stabilization and maturation. When B55? is inhibited, ECs cannot cope with cell stress and undergo apoptosis, leading to massive pruning of nascent blood vessels. Mechanistically, we found that the B55?/PP2A complex restrains PHD2 activity, promoting EC survival in a HIF-dependent manner, and furthermore dephosphorylates p38, altogether protecting ECs against cell stress occurring, for example, during the onset of blood flow. In tumors, EC-specific B55? deficiency induces pruning of immature-like tumor blood vessels resulting in delayed tumor growth and metastasis, without affecting non-pathological vessels. Consistently, systemic administration of a pan-PP2A inhibitor disrupts vascular network formation and tumor progression in vivo without additional effects on B55?-deficient vessels. Conclusions: Our data underline a unique role of the B55?/PP2A phosphatase complex in vessel remodeling and suggest the use of PP2A-inhibitors as potent anti-angiogenic drugs targeting specifically nascent blood vessels with a mode-of-action complementary to VEGF(R)-targeted therapies

B55α/PP2A Limits Endothelial Cell Apoptosis During Vascular Remodeling: A Complementary Approach To Disrupt Pathological Vessels?

RATIONALE: How endothelial cells (ECs) migrate and form an immature vascular plexus has been extensively studied. Yet, mechanisms underlying vascular remodeling remain poorly established. A better understanding of these processes may lead to the design of novel therapeutic strategies complementary to current angiogenesis inhibitors. OBJECTIVE: Starting from our previous observations that PP2A (protein phosphatase 2) regulates the HIF (hypoxia-inducible factor)/PHD-2 (prolyl hydroxylase 2)-constituted oxygen machinery, we hypothesized that this axis could play an important role during blood vessel formation, tissue perfusion, and oxygen restoration. METHODS AND RESULTS: We show that the PP2A regulatory subunit B55α is at the crossroad between vessel pruning and vessel maturation. Blood vessels with high B55α counter cell stress conditions and thrive for stabilization and maturation. When B55α is inhibited, ECs cannot cope with cell stress and undergo apoptosis, leading to massive pruning of nascent blood vessels. Mechanistically, we found that the B55α/PP2A complex restrains PHD-2 activity, promoting EC survival in a HIF-dependent manner, and furthermore dephosphorylates p38, altogether protecting ECs against cell stress occurring, for example, during the onset of blood flow. In tumors, EC-specific B55α deficiency induces pruning of immature-like tumor blood vessels resulting in delayed tumor growth and metastasis, without affecting nonpathological vessels. Consistently, systemic administration of a pan-PP2A inhibitor disrupts vascular network formation and tumor progression in vivo without additional effects on B55α-deficient vessels. CONCLUSIONS: Our data underline a unique role of the B55α/PP2A phosphatase complex in vessel remodeling and suggest the use of PP2A-inhibitors as potent antiangiogenic drugs targeting specifically nascent blood vessels with a mode-of-action complementary to VEGF-R (vascular endothelial growth factor receptor)-targeted therapies. Graphical Abstract: A graphical abstract is available for this article

B55PP2A Limits endothelial cell apoptosis during vascular remodeling: a complementary approach to kill pathological vessels?

ABSTRACT Rationale: How endothelial cells (ECs) migrate and form an immature vascular plexus has been extensively studied. Yet, mechanisms underlying vascular remodeling remain poorly established. A better understanding of these processes may lead to the design of novel therapeutic strategies complementary to current angiogenesis inhibitors. Objective: Starting from our previous observations that the PP2A phosphatase regulates the HIF/PHD2- constituted oxygen machinery, we hypothesized that this axis could play an important role during blood vessel formation, tissue perfusion and oxygen restoration. Methods and Results: We show that the regulatory PP2A-phosphatase subunit B55 is at the crossroad between vessel pruning and vessel maturation. Blood vessels with high B55 will counter cell stress conditions and thrive for stabilization and maturation. When B55 is inhibited, ECs cannot cope with cell stress and undergo apoptosis, leading to massive pruning of nascent blood vessels. Mechanistically, we found that the B55/PP2A complex restrains PHD2 activity, promoting EC survival in a HIF-dependent manner, and furthermore dephosphorylates p38, altogether protecting ECs against cell stress occurring, for example, during the onset of blood flow. In tumors, EC-specific B55 deficiency induces pruning of immature-like tumor blood vessels resulting in delayed tumor growth and metastasis, without affecting nonpathological vessels. Consistently, systemic administration of a pan-PP2A inhibitor disrupts vascular network formation and tumor progression in vivo without additional effects on B55-deficient vessels. Conclusions: Our data underline a unique role of the B55/PP2A phosphatase complex in vessel remodeling and suggest the use of PP2A-inhibitors as potent anti-angiogenic drugs targeting specifically nascent blood vessels with a mode-of-action complementary to VEGF(R)-targeted therapies. Keywords: Angiogenesis, B55/PP2A-phosphatase, development, tumor progression, apoptosis, transgenic mode

Human monocyte-derived suppressive cells (HuMoSC) for cell therapy in giant cell arteritis

This article is part of the Research Topic "Novel Therapeutic Options in Large Vessel Vasculitis".International audienceIntroduction The pathogenesis of Giant Cell Arteritis (GCA) relies on vascular inflammation and vascular remodeling, the latter being poorly controlled by current treatments. Methods This study aimed to evaluate the effect of a novel cell therapy, Human Monocyte-derived Suppressor Cells (HuMoSC), on inflammation and vascular remodeling to improve GCA treatment. Fragments of temporal arteries (TAs) from GCA patients were cultured alone or in the presence of HuMoSCs or their supernatant. After five days, mRNA expression was measured in the TAs and proteins were measured in culture supernatant. The proliferation and migration capacity of vascular smooth muscle cells (VSMCs) were also analyzed with or without HuMoSC supernatant. Results Transcripts of genes implicated in vascular inflammation ( CCL2 , CCR2 , CXCR3 , HLADR ), vascular remodeling ( PDGF , PDGFR ), angiogenesis (VEGF) and extracellular matrix composition ( COL1A1 , COL3A1 and FN1 ) were decreased in arteries treated with HuMoSCs or their supernatant. Likewise, concentrations of collagen-1 and VEGF were lower in the supernatants of TAs cultivated with HuMoSCs. In the presence of PDGF, the proliferation and migration of VSMCs were both decreased after treatment with HuMoSC supernatant. Study of the PDGF pathway suggests that HuMoSCs act through inhibition of mTOR activity. Finally, we show that HuMoSCs could be recruited in the arterial wall through the implication of CCR5 and its ligands. Conclusion Altogether, our results suggest that HuMoSCs or their supernatant could be useful to decrease vascular in flammation and remodeling in GCA, the latter being an unmet need in GCA treatment

Neointimal myofibroblasts contribute to maintaining Th1/Tc1 and Th17/Tc17 inflammation in giant cell arteritis

International audienceVascular smooth muscle cells (VSMCs) have been shown to play a role in the pathogenesis of giant cell arteritis (GCA) through their capacity to produce chemokines recruiting T cells and monocytes in the arterial wall and their ability to migrate and proliferate in the neointima where they acquire a myofibroblast (MF) phenotype, leading to vascular stenosis. This study aimed to investigate if MFs could also impact T-cell polarization. Confocal microscopy was used to analyze fresh fragments of temporal artery biopsies (TABs). Healthy TAB sections were cultured to obtain MFs, which were then treated or not with interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) and analyzed by immunofluorescence and RT-PCR. After peripheral blood mononuclear cells and MFs were co-cultured for seven days, T-cell polarization was analyzed by flow cytometry. In the neointima of GCA arteries, we observed a phenotypic heterogeneity among VSMCs that was consistent with a MF phenotype (α-SMA + CD90 + desmin + MYH11 +) with a high level of STAT1 phosphorylation. Co-culture experiments showed that MFs sustain Th1/Tc1 and Th17/Tc17 polarizations. The increased Th1 and Tc1 polarization was further enhanced following the stimulation of MFs with IFN-γ and TNF-α, which induced STAT1 phosphorylation in MFs. These findings correlated with increases in the production of IL-1β, IL-6, IL-12 and IL-23 by MFs. Our study showed that MFs play an additional role in the pathogenesis of GCA through their ability to maintain Th17/Tc17 and Th1/Tc1 polarizations, the latter being further enhanced in case of stimulation of MF with IFN-γ and TNF-α