ROR2 blockade as a therapy for osteoarthritis

Osteoarthritis is characterized by the loss of the articular cartilage, bone remodeling, pain, and disability. No pharmacological intervention can currently halt progression of osteoarthritis. Here, we show that blocking receptor tyrosine kinase–like orphan receptor 2 (ROR2) improves cartilage integrity and pain in osteoarthritis models by inhibiting yes-associated protein (YAP) signaling. ROR2 was up-regulated in the cartilage in response to inflammatory cytokines and mechanical stress. The main ligand for ROR2, WNT5A, and the targets YAP and connective tissue growth factor were up-regulated in osteoarthritis in humans. In vitro, ROR2 overexpression inhibited chondrocytic differentiation. Conversely, ROR2 blockade triggered chondrogenic differentiation of C3H10T1/2 cells and suppressed the expression of the cartilage-degrading enzymes a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)–4 and ADAMTS-5. The chondrogenic effect of ROR2 blockade in the cartilage was independent of WNT signaling and was mediated by down-regulation of YAP signaling. ROR2 signaling induced G protein and Rho-dependent nuclear accumulation of YAP, and YAP inhibition was required but not sufficient for ROR2 blockade–induced chondrogenesis. ROR2 silencing protected mice from instability-induced osteoarthritis with improved structural outcomes, sustained pain relief, and without apparent side effects or organ toxicity. Last, ROR2 silencing in human articular chondrocytes transplanted in nude mice led to the formation of cartilage organoids with more and better differentiated extracellular matrix, suggesting that the anabolic effect of ROR2 blockade is conserved in humans. Thus, ROR2 blockade is efficacious and well tolerated in preclinical animal models of osteoarthritis

WNT16 antagonises excessive canonical WNT activation and protects cartilage in osteoarthritis

Objective: Both excessive and insufficient activation of WNT signalling results in cartilage breakdown and osteoarthritis. WNT16 is upregulated in the articular cartilage following injury and in osteoarthritis. Here, we investigate the function of WNT16 in osteoarthritis and the downstream molecular mechanisms. Methods: Osteoarthritis was induced by destabilisation of the medial meniscus in wild-type and WNT16-deficient mice. Molecular mechanisms and downstream effects were studied in vitro and in vivo in primary cartilage progenitor cells and primary chondrocytes. The pathway downstream of WNT16 was studied in primary chondrocytes and using the axis duplication assay in Xenopus. Results: WNT16-deficient mice developed more severe osteoarthritis with reduced expression of lubricin and increased chondrocyte apoptosis. WNT16 supported the phenotype of cartilage superficial-zone progenitor cells and lubricin expression. Increased osteoarthritis in WNT16-deficient mice was associated with excessive activation of canonical WNT signalling. In vitro, high doses of WNT16 weakly activated canonical WNT signalling, but, in costimulation experiments, WNT16 reduced the capacity of WNT3a to activate the canonical WNT pathway. In vivo, WNT16 rescued the WNT8-induced primary axis duplication in Xenopus embryos. Conclusions: In osteoarthritis, WNT16 maintains a balanced canonical WNT signalling and prevents detrimental excessive activation, thereby supporting the homeostasis of progenitor cells

Agrin induces long-term osteochondral regeneration by supporting repair morphogenesis.

Cartilage loss leads to osteoarthritis, the most common cause of disability for which there is no cure. Cartilage regeneration, therefore, is a priority in medicine. We report that agrin is a potent chondrogenic factor and that a single intraarticular administration of agrin induced long-lasting regeneration of critical-size osteochondral defects in mice, with restoration of tissue architecture and bone-cartilage interface. Agrin attracted joint resident progenitor cells to the site of injury and, through simultaneous activation of CREB and suppression of canonical WNT signaling downstream of β-catenin, induced expression of the chondrogenic stem cell marker GDF5 and differentiation into stable articular chondrocytes, forming stable articular cartilage. In sheep, an agrin-containing collagen gel resulted in long-lasting regeneration of bone and cartilage, which promoted increased ambulatory activity. Our findings support the therapeutic use of agrin for joint surface regeneration

Disease modification and symptom relief in osteoarthritis using a mutated GCP-2/CXCL6 chemokine

We showed that the chemokine receptor C-X-C Motif Chemokine Receptor 2 (CXCR2) is essential for cartilage homeostasis. Here, we reveal that the CXCR2 ligand granulocyte chemotactic protein 2 (GCP-2) was expressed, during embryonic development, within the prospective permanent articular cartilage, but not in the epiphyseal cartilage destined to be replaced by bone. GCP-2 expression was retained in adult articular cartilage. GCP-2 loss-of-function inhibited extracellular matrix production. GCP-2 treatment promoted chondrogenesis in vitro and in human cartilage organoids implanted in nude mice in vivo. To exploit the chondrogenic activity of GCP-2, we disrupted its chemotactic activity, by mutagenizing a glycosaminoglycan binding sequence, which we hypothesized to be required for the formation of a GCP-2 haptotactic gradient on endothelia. This mutated version (GCP-2-T) had reduced capacity to induce transendothelial migration in vitro and in vivo, without affecting downstream receptor signaling through AKT, and chondrogenic activity. Intra-articular adenoviral overexpression of GCP-2-T, but not wild-type GCP-2, reduced pain and cartilage loss in instability-induced osteoarthritis in mice. We suggest that GCP-2-T may be used for disease modification in osteoarthritis.</p

Genetic Variability in Nodulation and Root Growth Affects Nitrogen Fixation and Accumulation in Pea

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699International audienceBackground and Aims Legume nitrogen is derived from two different sources, symbiotically fixed atmospheric N-2 and soil N. The effect of genetic variability of root and nodule establishment on N acquisition and seed protein yield was investigated under field conditions in pea (Pisum sativum). In addition, these parameters were related to the variability in preference for rhizobial genotypes. Methods Five different spring pea lines (two hypernodulating mutants and three cultivars), previously identified in artificial conditions as contrasted for both root and nodule development, were characterized under field conditions. Root and nodule establishment was examined from the four-leaf stage up to the beginning of seed filling and was related to the patterns of shoot dry matter and nitrogen accumulation. The genetic structure of rhizobial populations associated with the pea lines was obtained by analysis of nodule samples. The fraction of nitrogen derived from symbiotic fixation was estimated at the beginning of seed filling and at physiological maturity, when seed protein content and yield were determined. Key Results The hypernodulating mutants established nodules earlier and maintained them longer than was the case for the three cultivars, whereas their root development and nitrogen accumulation were lower. The seed protein yield was higher in 'Athos' and 'Austin', the two cultivars with increased root development, consistent with their higher N absorption during seed filling. Conclusion The hypernodulating mutants did not accumulate more nitrogen, probably due to the C cost for nodulation being higher than for root development. Enhancing exogenous nitrogen supply at the end of the growth cycle, by increasing the potential for root N uptake from soil, seems a good option for improving pea seed filling

Disease modification and symptom relief in osteoarthritis using a mutated GCP‐2/CXCL6 chemokine

Abstract We showed that the chemokine receptor C‐X‐C Motif Chemokine Receptor 2 (CXCR2) is essential for cartilage homeostasis. Here, we reveal that the CXCR2 ligand granulocyte chemotactic protein 2 (GCP‐2) was expressed, during embryonic development, within the prospective permanent articular cartilage, but not in the epiphyseal cartilage destined to be replaced by bone. GCP‐2 expression was retained in adult articular cartilage. GCP‐2 loss‐of‐function inhibited extracellular matrix production. GCP‐2 treatment promoted chondrogenesis in vitro and in human cartilage organoids implanted in nude mice in vivo. To exploit the chondrogenic activity of GCP‐2, we disrupted its chemotactic activity, by mutagenizing a glycosaminoglycan binding sequence, which we hypothesized to be required for the formation of a GCP‐2 haptotactic gradient on endothelia. This mutated version (GCP‐2‐T) had reduced capacity to induce transendothelial migration in vitro and in vivo, without affecting downstream receptor signaling through AKT, and chondrogenic activity. Intra‐articular adenoviral overexpression of GCP‐2‐T, but not wild‐type GCP‐2, reduced pain and cartilage loss in instability‐induced osteoarthritis in mice. We suggest that GCP‐2‐T may be used for disease modification in osteoarthritis

Efficacy and safety of two neutralising monoclonal antibody therapies, sotrovimab and BRII-196 plus BRII-198, for adults hospitalised with COVID-19 (TICO): a randomised controlled trial

We aimed to assess the efficacy and safety of two neutralising monoclonal antibody therapies (sotrovimab [Vir Biotechnology and GlaxoSmithKline] and BRII-196 plus BRII-198 [Brii Biosciences]) for adults admitted to hospital for COVID-19 (hereafter referred to as hospitalised) with COVID-19. In this multinational, double-blind, randomised, placebo-controlled, clinical trial (Therapeutics for Inpatients with COVID-19 [TICO]), adults (aged ≥18 years) hospitalised with COVID-19 at 43 hospitals in the USA, Denmark, Switzerland, and Poland were recruited. Patients were eligible if they had laboratory-confirmed SARS-CoV-2 infection and COVID-19 symptoms for up to 12 days. Using a web-based application, participants were randomly assigned (2:1:2:1), stratified by trial site pharmacy, to sotrovimab 500 mg, matching placebo for sotrovimab, BRII-196 1000 mg plus BRII-198 1000 mg, or matching placebo for BRII-196 plus BRII-198, in addition to standard of care. Each study product was administered as a single dose given intravenously over 60 min. The concurrent placebo groups were pooled for analyses. The primary outcome was time to sustained clinical recovery, defined as discharge from the hospital to home and remaining at home for 14 consecutive days, up to day 90 after randomisation. Interim futility analyses were based on two seven-category ordinal outcome scales on day 5 that measured pulmonary status and extrapulmonary complications of COVID-19. The safety outcome was a composite of death, serious adverse events, incident organ failure, and serious coinfection up to day 90 after randomisation. Efficacy and safety outcomes were assessed in the modified intention-to-treat population, defined as all patients randomly assigned to treatment who started the study infusion. This study is registered with ClinicalTrials.gov, NCT04501978. Between Dec 16, 2020, and March 1, 2021, 546 patients were enrolled and randomly assigned to sotrovimab (n=184), BRII-196 plus BRII-198 (n=183), or placebo (n=179), of whom 536 received part or all of their assigned study drug (sotrovimab n=182, BRII-196 plus BRII-198 n=176, or placebo n=178; median age of 60 years [IQR 50–72], 228 [43%] patients were female and 308 [57%] were male). At this point, enrolment was halted on the basis of the interim futility analysis. At day 5, neither the sotrovimab group nor the BRII-196 plus BRII-198 group had significantly higher odds of more favourable outcomes than the placebo group on either the pulmonary scale (adjusted odds ratio sotrovimab 1·07 [95% CI 0·74–1·56]; BRII-196 plus BRII-198 0·98 [95% CI 0·67–1·43]) or the pulmonary-plus complications scale (sotrovimab 1·08 [0·74–1·58]; BRII-196 plus BRII-198 1·00 [0·68–1·46]). By day 90, sustained clinical recovery was seen in 151 (85%) patients in the placebo group compared with 160 (88%) in the sotrovimab group (adjusted rate ratio 1·12 [95% CI 0·91–1·37]) and 155 (88%) in the BRII-196 plus BRII-198 group (1·08 [0·88–1·32]). The composite safety outcome up to day 90 was met by 48 (27%) patients in the placebo group, 42 (23%) in the sotrovimab group, and 45 (26%) in the BRII-196 plus BRII-198 group. 13 (7%) patients in the placebo group, 14 (8%) in the sotrovimab group, and 15 (9%) in the BRII-196 plus BRII-198 group died up to day 90. Neither sotrovimab nor BRII-196 plus BRII-198 showed efficacy for improving clinical outcomes among adults hospitalised with COVID-19. US National Institutes of Health and Operation Warp Spee