Visual outcomes after cataract surgery in monocular compared to binocular patients: a case-control study.

PURPOSE: We aimed to identify ocular comorbidities and reasons of blindness in monocular patients and to compare visual outcomes of cataract surgery between monocular and binocular patients. METHODS: A single-center case-control study was conducted between November 2011 and May 2019 to compare consecutive series of patients needing cataract surgery in Strasbourg University Hospitals, France. Cases were patients with permanent monocular vision loss. Controls were binocularly sighted patients. All patients underwent cataract surgery using phacoemulsification technique. Chart analysis included demographic data, medical history, and surgical determinants data. Student's t tests and Fisher's exact tests were the main methods used for statistical analysis. RESULTS: Each group included 80 patients. The mean age at the time of surgery was significantly higher in monocular than binocular patients (77 vs. 71 years, p < 0.001). Thirty-two monocular patients (40%) had ocular comorbidities, compared to only 19 (23%) in the control group (p < 0.05). The leading cause of monocular status was amblyopia caused by strabismus (22 patients, 27.5%). Age-related macular degeneration, open-angle glaucoma, and diabetic retinopathy were the three main ocular comorbidities that were observed in the monocular group. Monocular patients had significantly lower visual acuity than the control group (p < 0.01) before and after cataract surgery. Conversely, improvement in visual acuity after surgery was not statistically different between groups (p = 0.054). There was no statistically significant difference in the rate of surgical complications between groups (p = 0.622). CONCLUSIONS: This study illustrates that cataract surgery in monocular patients is not more complicated than in binocular patients, but that it is significantly delayed.

Autophagy Targeting and Hematological Mobilization in FLT3-ITD Acute Myeloid Leukemia Decrease Repopulating Capacity and Relapse by Inducing Apoptosis of Committed Leukemic Cells.

Targeting FLT3-ITD in AML using TKI against FLT3 cannot prevent relapse even in the presence of complete remission, suggesting the resistance and/or the persistence of leukemic-initiating cells in the hematopoietic niche. By mimicking the hematopoietic niche condition with cultures at low oxygen concentrations, we demonstrate in vitro that FLT3-ITD AML cells decrease their repopulating capacity when Vps34 is inhibited. Ex vivo, AML FLT3-ITD blasts treated with Vps34 inhibitors recovered proliferation more slowly due to an increase an apoptosis. In vivo, mice engrafted with FLT3-ITD AML MV4-11 cells have the invasion of the bone marrow and blood in 2 weeks. After 4 weeks of FLT3 TKI treatment with gilteritinib, the leukemic burden had strongly decreased and deep remission was observed. When treatment was discontinued, mice relapsed rapidly. In contrast, Vps34 inhibition strongly decreased the relapse rate, and even more so in association with mobilization by G-CSF and AMD3100. These results demonstrate that remission offers the therapeutic window for a regimen using Vps34 inhibition combined with mobilization to target persistent leukemic stem cells and thus decrease the relapse rate.

Dual Inhibition of FLT3 and AXL by Gilteritinib Overcomes Hematopoietic Niche-Driven Resistance Mechanisms in FLT3-ITD Acute Myeloid Leukemia.

PURPOSE: AXL has been shown to play a pivotal role in the selective response of FLT3-ITD acute myeloid leukemia (AML) cells to FLT3 tyrosine kinase inhibitors (TKI), particularly within the bone marrow microenvironment. EXPERIMENTAL DESIGN: Herein, we compared the effect of dual FLT3/AXL-TKI gilteritinib with quizartinib through in vitro models mimicking hematopoietic niche conditions, ex vivo in primary AML blasts, and in vivo with dosing regimens allowing plasma concentration close to those used in clinical trials. RESULTS: We observed that gilteritinib maintained a stronger proapoptotic effect in hypoxia and coculture with bone marrow stromal cells compared with quizartinib, linked to a dose-dependent inhibition of AXL phosphorylation. In vivo, use of the MV4-11 cell line with hematopoietic engraftment demonstrated that gilteritinib was more effective than quizartinib at targeting leukemic cells in bone marrow. Finally, FLT3-ITD AML patient-derived xenografts revealed that this effect was particularly reproducible in FLT3-ITD AML with high allelic ratio in primary and secondary xenograft. Moreover, gilteritinib and quizartinib displayed close toxicity profile on normal murine hematopoiesis, particularly at steady state. CONCLUSIONS: Overall, these findings suggest that gilteritinib as a single agent, compared with quizartinib, is more likely to reach leukemic cells in their protective microenvironment, particularly AML clones highly dependent on FLT3-ITD signaling.

In Vitro Impact of Pro-Senescent Endothelial Microvesicles on Isolated Pancreatic Rat Islets Function.

BACKGROUND: Ischemia-driven islet isolation procedure is one of the limiting causes of pancreatic islet transplantation. Ischemia-reperfusion process is associated with endothelium dysfunction and the release of pro-senescent microvesicles. We investigated whether pro-senescent endothelial microvesicles prompt islet senescence and dysfunction in vitro. MATERIAL AND METHODS: Pancreatic islets were isolated from male young rats. Replicative endothelial senescence was induced by serial passaging of primary porcine coronary artery endothelial cells, and microvesicles were isolated either from young passage 1 (P1) or senescent passage 3 (P3) endothelial cells. Islet viability was assessed by fluorescence microscopy, apoptosis by flow cytometry, and Western blot. Function was assessed by insulin secretion and islet senescence markers p53, p21, and p16 by Western blot. Microvesicles were stained by the PKH26 lipid fluorescent probe and their islet integration assessed by microscopy and flow cytometry. RESULTS: Regardless of the passage, half microvesicles were integrated in target islets after 24 hours incubation. Insulin secretion significantly decreased after treatment by senescent microvesicles (P3: 1.7 ± 0.2 vs untreated islet: 2.7 ± 0.2, P < .05) without altering the islet viability (89.47% ± 1.69 vs 93.15% ± 0.97) and with no significant apoptosis. Senescent microvesicles significantly doubled the expression of p53, p21, and p16 (P < .05), whereas young microvesicles had no significant effect. CONCLUSION: Pro-senescent endothelial microvesicles specifically accelerate the senescence of islets and alter their function. These data suggest that islet isolation contributes to endothelial driven islet senescence.

Significance of neutrophil microparticles in ischaemia-reperfusion: Pro-inflammatory effectors of endothelial senescence and vascular dysfunction.

Endothelial senescence is an emerging cause of vascular dysfunction. Because microparticles are effectors of endothelial inflammation and vascular injury after ischaemia-reperfusion, we examined leucocyte-derived microparticles of spleen origin as possible contributors. Microparticles were generated from primary rat splenocytes by either lipopolysaccharide or phorbol-myristate-acetate/calcium ionophore, under conditions mimicking innate and adaptive immune responses. Incubation of primary porcine coronary endothelial cells with either type of microparticles, but not with those from unstimulated splenocytes, leads to a similar threefold raise in senescence-associated ß-galactosidase activity within 48 hours, indicating accelerated senescence, to endothelial oxidative stress, and a fivefold and threefold increase in p21 and p16 senescence markers after 24 hours. After 12-hour incubation, the endothelial-dependent relaxation of coronary artery rings was reduced by 50%, at distinct optimal microparticle concentration. In vitro, microparticles were pro-thrombotic by up-regulating the local angiotensin system, by prompting tissue factor activity and a secondary generation of pro-coagulant endothelial microparticles. They initiated an early pro-inflammatory response by inducing phosphorylation of NF-κB, MAP kinases and Akt after 1 hour, and up-regulated VCAM-1 and ICAM-1 at 24 hours. Accordingly, VCAM-1 and COX-2 were also up-regulated in the coronary artery endothelium and eNOS down-regulated. Lipopolysaccharide specifically favoured the shedding of neutrophil- and monocyte-derived microparticles. A 80% immuno-depletion of neutrophil microparticles reduced endothelial senescence by 55%, indicating a key role. Altogether, data suggest that microparticles from activated splenocytes prompt early pro-inflammatory, pro-coagulant and pro-senescent responses in endothelial cells through redox-sensitive pathways. The control of neutrophil shedding could preserve the endothelium at site of ischaemia-reperfusion-driven inflammation and delay its dysfunction.

Epithelial-mesenchymal transition and membrane microparticles: Potential implications for bronchiolitis obliterans syndrome after lung transplantation.

Long term survival post lung transplantation (LTx) is limited by the occurrence of bronchiolitis obliterans syndrome (BOS). One mechanism involved is the epithelial-mesenchymal transition (EMT). Membrane microparticles (MPs) are known to be involved in some respiratory diseases and in other organs allograft rejection episodes. We hypothesized that leukocyte-derived MPs likely contribute to EMT. To emphasize this physiological concept, our objectives were to: (1) confirm the presence of EMT on explanted lungs from patients who underwent a second LTx for BOS; 2) characterize circulating MPs in transplanted patients, with or without BOS; (3) evaluate in vitro the effect of monocyte-derived MPs in EMT of human bronchial epithelial cells. Our IHC analysis on explanted graft lungs revealed significant pathological signs of EMT with an inhomogeneous destruction of the bronchial epithelium, with decreased expression of the epithelial protein E-cadherin and increased expression of the mesenchymal protein Vimentin. The immunophenotyping of MPs demonstrated that the concentration of MPs carrying E-cadherin was lower in patients affected by BOS (p = .007). In vitro, monocyte-derived MPs produced with LPS were associated with decreased E-cadherin expression (p < .05) along with significant morphological and functional cell modifications. MPs may play a role in EMT onset in bronchial epithelium following LTx.

Assessment of plasma microvesicles to monitor pancreatic islet graft dysfunction: Beta cell- and leukocyte-derived microvesicles as specific features in a pilot longitudinal study.

Markers of early pancreatic islet graft dysfunction and its causes are lacking. We monitored 19 type 1 diabetes islet-transplanted patients for up to 36 months following last islet injection. Patients were categorized as Partial (PS) or complete (S) Success, or Graft Failure (F), using the ß-score as an indicator of graft function. F was the subset reference of maximum worsened graft outcome. To identify the immune, pancreatic, and liver contribution to the graft dysfunction, the cell origin and concentration of circulating microvesicles (MVs) were assessed, including MVs from insulin-secreting ß-cells typified by polysialic acid of neural cell adhesion molecule (PSA-NCAM), and data were compared with values of the ß-score. Similar ranges of PSA-NCAM+ -MVs were found in healthy volunteers and S patients, indicating minimal cell damage. In PS, a 2-fold elevation in PSA-NCAM+ -MVs preceded each ß-score drop along with a concomitant rise in insulin needs, suggesting ß-cell damage or altered function. Significant elevation of liver asialoglycoprotein receptor (ASGPR)+ -MVs, endothelial CD105+ -MVs, neutrophil CD66b+ -MVs, monocyte CD 14+ -MVs, and T4 lymphocyte CD4+ -MVs occurred before each ß-score drop, CD8+ -MVs increased only in F, and B lymphocyte CD19+ -MVs remained undetectable. In conclusion, PSA-NCAM+ -MVs are noninvasive early markers of transplant dysfunction, while ASGPR+ -MVs signal host tissue remodeling. Leukocyte MVs could identify the cause of graft dysfunction.

Endothelial microparticles released by activated protein C protect beta cells through EPCR/PAR1 and annexin A1/FPR2 pathways in islets.

Islet transplantation is associated with early ischaemia/reperfusion, localized coagulation and redox-sensitive endothelial dysfunction. In animal models, islet cytoprotection by activated protein C (aPC) restores islet vascularization and protects graft function, suggesting that aPC triggers various lineages. aPC also prompts the release of endothelial MP that bear EPCR, its specific receptor. Microparticles (MP) are plasma membrane procoagulant vesicles, surrogate markers of stress and cellular effectors. We measured the cytoprotective effects of aPC on endothelial and insulin-secreting Rin-m5f ß-cells and its role in autocrine and paracrine MP-mediated cell crosstalk under conditions of oxidative stress. MP from aPC-treated primary endothelial (EC) or ß-cells were applied to H2 O2 -treated Rin-m5f. aPC activity was measured by enzymatic assay and ROS species by dihydroethidium. The capture of PKH26-stained MP and the expression of EPCR were probed by fluorescence microscopy and apoptosis by flow cytometry. aPC treatment enhanced both annexin A1 (ANXA1) and PAR-1 expression in EC and to a lesser extent in ß-cells. MP from aPC-treated EC (eMaPC ) exhibited high EPCR and annexin A1 content, protected ß-cells, restored insulin secretion and were captured by 80% of ß cells in a phosphatidylserine and ANXA1-dependent mechanism. eMP activated EPCR/PAR-1 and ANXA1/FPR2-dependent pathways and up-regulated the expression of EPCR, and of FPR2/ALX, the ANXA1 receptor. Cytoprotection was confirmed in H2 O2 -treated rat islets with increased viability (62% versus 48% H2 O2 ), reduced apoptosis and preserved insulin secretion in response to glucose elevation (16 versus 5 ng/ml insulin per 10 islets). MP may prove a promising therapeutic tool in the protection of transplanted islets.

Senescence of Pancreas in Middle-Aged Rats with Normal Vascular Function.

BACKGROUND In organ transplantation, particularly pancreas transplantation, donor age is a determinant factor for graft survival. Physiological aging is crucial in the progressive deterioration of organs in adulthood. We compared the senescence and function features of pancreas and vascular tissues in young rats and middle-aged rats. MATERIAL AND METHODS Islet morphology and the area of cells secreting insulin or glucagon was investigated using immunohistology in young rats (12 weeks) and middle-aged rats (52 weeks) (n=8). Senescence markers, oxidative stress (ROS), and tissue factor (TF) were measured in the rat pancreases. Circulating microparticles (MPs) were measured as surrogates of vascular cell injury. Vascular function was studied in mesenteric arterial rings. RESULTS Larger islets were twice as frequent in young rats versus middle-aged rats. In middle-aged rats there was a significant decrease of the ß-cells/islet area ratio. Western blot analysis showed an increased expression of p53, p21, and p16 senescence markers (2-, 7- and 3-fold respectively) with no modification in caspase-3 activation. A 30% decrease of endothelial nitric oxide synthase (eNOS) was observed together with a 4-fold increase in TF expression. ROS formation increased significantly (2-fold) in middle-aged rats and their main source, determined by pharmacological inhibition, was NADPH oxidase and uncoupled nitric-oxide (NO) synthase. No sign of vascular injury (microparticles) or dysfunction was evidenced. CONCLUSIONS Modification in islet morphology and function were detected in middle-aged rats before any measurement of macro-vascular dysfunction. The data indicate a pancreatic senescence in the process of aging associated with uncontrolled accumulation of oxidative species that suggests a determining role of donor age in transplantation.