PRL-3/PTP4A3 phosphatase regulates integrin ß1 in adhesion structures during migration of human ocular melanoma cells.

In a previous transcriptomic analysis of 63 ocular melanomas of the uvea, we found that expression of the PRL-3/PTP4A3 gene, encoding a phosphatase that is anchored to the plasma membrane, was associated with the risk of metastasis, and a poor prognosis. We also showed that PRL-3 overexpression in OCM-1 ocular melanoma cells significantly increased cell migration in vitro and invasiveness in vivo, suggesting a direct role for PRL-3 in the metastatic spreading of uveal melanoma. Here, we aimed to identify PRL-3 substrates at the plasma membrane involved in adhesion to the extracellular matrix. We focused on integrin ß1, which is the most highly expressed integrin in our cohort of uveal melanomas. We show that preventing PRL-3 anchorage to the plasma membrane i) abolishes PRL-3-induced migration in OCM-1 cells, ii) specifically enhances the spreading of OCM-1 cells overexpressing PRL-3, and iii) favors the maturation of large focal adhesions (FAs) containing integrin ß1 on collagen I. Knockdown experiments confirmed integrin ß1 involvement in PRL3-induced migration. We identified interactions between PRL-3 and integrin ß1, as well as with FAK P-Y397, an auto-activated form of Focal Adhesion Kinase found in FAs. We also show that integrin ß1 may be dephosphorylated by PRL-3 in its intracytoplasmic S/T region, an important motif for integrin-mediated cell adhesion. Finally, we observed that PRL-3 regulated the clustering of integrin ß1 in FAs on collagen I but not on fibronectin. This work identifies PRL-3 as a new regulator of cell adhesion structures to the extracellular matrix, and further supports PRL-3 as a key actor of metastasis in uveal melanoma, of which molecular mechanisms are still poorly understood.

Effects of compression garments on balance in hypermobile Ehlers-Danlos syndrome: a randomized controlled trial.

PURPOSE: To evaluate the immediate and 4-week effects of compression garments (CG) on balance using a force platform during 8 different visual, static, and dynamic conditions in hypermobile Ehlers-Danlos Syndrome (hEDS) patients. METHODS: Thirty-six participants were randomly assigned to a group: physiotherapy alone (PT, n = 19) or physiotherapy and daily CG wearing for 4 weeks (PT + CG, n = 17). Both attended 12 physiotherapy sessions (strengthening, proprioception, and balance exercises) for 4 weeks. Primary outcome: sway velocity of the centre of pressure (COP) measured before, immediately with the CG, and at 4 weeks. Secondary outcomes: ellipse area, Romberg quotient, and pain. RESULTS: Sway velocity in dynamic conditions decreased immediately with the CG. After 4 weeks of intervention, sway velocity (95% CI 4.36-39.23, effect size 0.93) and area (95% CI 146-3274, effect size 0.45) on the laterally oscillating platform with eyes-closed improved more in the PT + CG group than the PT group. Romberg quotient on foam cushion improved more in the PT + CG than the PT group. Pain decreased in both groups after 4 weeks with no between-group difference. CONCLUSION: CG combined with physiotherapy improved dynamic balance measured with COP variables significantly more than physiotherapy alone in people with hEDS. TRIAL REGISTRATION: NCT03359135Implications for RehabilitationCompression garments immediately improve balance in people with hypermobile Ehlers-Danlos Syndrome (hEDS)Compression garments combined with regular physiotherapy improve balance in people with hEDS after 4 weeks of treatmentCompression garments could compensate for proprioceptive impairment in hEDS.

A severe case of PLOD1-related kyphoscoliotic Ehlers-Danlos syndrome associated with several arterial and venous complications: A case report.

Kyphoscoliotic Ehlers-Danlos syndrome (kEDS) is a rare genetic disorder combining congenital hypotonia, congenital/early onset and progressive kyphoscoliosis, and generalized joint hypermobility. Vascular fragility is another characteristic of the disease rarely described. We report a severe case of kEDS-PLOD1 with several vascular complications leading to difficulties in disease management.

Classical Ehlers-Danlos syndrome with severe kyphoscoliosis due to a novel pathogenic variant of COL5A2.

We described a novel de novo missense variant of the gene encoding Collagen alpha-2(V) chain, associated with the classical Ehlers-Danlos syndrome (cEDS) (OMIM#130010), in a 14-year-old patient who presented with congenital and severe scoliosis, muscle hypotonia, ocular manifestations, and no atrophic scaring. This case expands the phenotypic spectrum of cEDS.

A novel COL1A1 variant in a family with clinical features of hypermobile Ehlers-Danlos syndrome that proved to be a COL1-related overlap disorder.

COL1-related overlap disorder is a condition, which is not yet considered as part of the 2017 EDS classification. However, it should be investigated as an alternative diagnosis for any patient with hypermobile EDS. This could allow providing appropriate genetic counseling.

Protein Tyrosine Phosphatase 4A3 (PTP4A3) Promotes Human Uveal Melanoma Aggressiveness Through Membrane Accumulation of Matrix Metalloproteinase 14 (MMP14).

PURPOSE: To study PTP4A3 phosphatase and MMP14 metalloprotease synergy in uveal melanoma aggressiveness. METHODS: Cell membrane localization of matrix metalloprotease 14 (MMP14) in uveal melanoma cells expressing protein tyrosine phosphatase A3 (PTP4A3) was assessed by flow cytometry or immunohistochemistry. The vesicular trafficking of MMP14 in the presence of PTP4A3 was evaluated in OCM-1 cells expressing either the wild-type or mutated phosphatase. Finally, MMP14 localization at the cell membrane of OCM-1 cells was impaired using RNA interference, and the PTP4A3-related migration in vitro and invasiveness in vivo of the treated cells were evaluated. RESULTS: We found that the membrane-anchored MMP14 is enriched at the cell surface of OCM-1 cells, patient-derived xenograft cells, and human primary uveal melanoma tumors expressing PTP4A3. Moreover, we show that PTP4A3 and MMP14 colocalize and that the vesicular trafficking of MMP14 is faster in the presence of active PTP4A3. Finally, we demonstrate that inhibition of MMP14 expression in uveal melanoma cells expressing PTP4A3 impairs their migration in vitro and invasiveness in vivo. CONCLUSIONS: Our observations indicate that PTP4A3 increases cell membrane accumulation of MMP14 as a result of increased cellular trafficking of the metalloprotease. We also show that downregulation of MMP14 expression reduced PTP4A3-induced cell migration and invasiveness. Taken together, our findings suggest that PTP4A3-related subcellular localization of MMP14 is an important event in metastasis induction.