Angiogenesis is a multistep process that requires coordinated migration, proliferation, and junction formation of vascular endothelial cells (ECs) to form new vessel branches in response to growth ...stimuli. Major intracellular signaling pathways that regulate angiogenesis have been well elucidated, but key transcriptional regulators that mediate these signaling pathways and control EC behaviors are only beginning to be understood. Here, we show that YAP/TAZ, a transcriptional coactivator that acts as an end effector of Hippo signaling, is critical for sprouting angiogenesis and vascular barrier formation and maturation. In mice, endothelial-specific deletion of Yap/Taz led to blunted-end, aneurysm-like tip ECs with fewer and dysmorphic filopodia at the vascular front, a hyper-pruned vascular network, reduced and disarranged distributions of tight and adherens junction proteins, disrupted barrier integrity, subsequent hemorrhage in growing retina and brain vessels, and reduced pathological choroidal neovascularization. Mechanistically, YAP/TAZ activates actin cytoskeleton remodeling, an important component of filopodia formation and junction assembly. Moreover, YAP/TAZ coordinates EC proliferation and metabolic activity by upregulating MYC signaling. Overall, these results show that YAP/TAZ plays multifaceted roles for EC behaviors, proliferation, junction assembly, and metabolism in sprouting angiogenesis and barrier formation and maturation and could be a potential therapeutic target for treating neovascular diseases.
The activation of transcriptional coactivators YAP and its paralog TAZ has been shown to promote resistance to anti‐cancer therapies. YAP/TAZ activity is tightly coupled to actin cytoskeleton ...architecture. However, the influence of actin remodeling on cancer drug resistance remains largely unexplored. Here, we report a pivotal role of actin remodeling in YAP/TAZ‐dependent BRAF inhibitor resistance in BRAF V600E mutant melanoma cells. Melanoma cells resistant to the BRAF inhibitor PLX4032 exhibit an increase in actin stress fiber formation, which appears to promote the nuclear accumulation of YAP/TAZ. Knockdown of YAP/TAZ reduces the viability of resistant melanoma cells, whereas overexpression of constitutively active YAP induces resistance. Moreover, inhibition of actin polymerization and actomyosin tension in melanoma cells suppresses both YAP/TAZ activation and PLX4032 resistance. Our siRNA library screening identifies actin dynamics regulator TESK1 as a novel vulnerable point of the YAP/TAZ‐dependent resistance pathway. These results suggest that inhibition of actin remodeling is a potential strategy to suppress resistance in BRAF inhibitor therapies.
Synopsis
BRAF V600E mutant melanoma cells undergo active actin cytoskeletal remodeling in response to the BRAF inhibitor PLX4032, and the remodeling promotes nuclear localization of YAP/TAZ oncoproteins, conferring adaptive resistance to PLX4032.
The development of PLX4032 resistance in melanoma cell lines is accompanied by increases in both actin stress fiber formation and cell spreading on substrates.
PLX4032‐resistant melanoma cells exhibit higher levels of YAP/TAZ nuclear localization and transcriptional activity.
Inhibition of actin filament assembly or actin cytoskeletal tension suppresses YAP/TAZ activation and PLX4032 resistance in melanoma cells.
Depletion of YAP/TAZ restores PLX4032 sensitivity in resistant cells, whereas overexpression of constitutively active YAP induces PLX4032 resistance in non‐resistant melanoma cells.
Adaptive resistance to the BRAF inhibitor PLX4032 in BRAF V600E mutant melanoma cells involves increased actin stress fiber formation, impinging on the growth‐regulating YAP/TAZ signaling axis.
The actin cytoskeleton has been implicated in the assembly of cilia, but roles of actin-dependent motor proteins in ciliogenesis remain unclear. Myosin heavy chain 10 (MYH10), one of the isoforms of ...non-muscle myosin II, is known to mediate centrosome reorientation during cell migration. Here we show that MYH10 is required for centriole migration to the apical plasma membrane, which occurs at the onset of ciliogenesis. Knockdown of MYH10 in RPE1 cells caused a reduction in the levels of cortical filamentous actin (F-actin) and its binding protein EZRIN. Moreover, both centriole migration and subsequent cilium assembly were defective in MYH10 depleted cells. We further found that MYH10 influences centrosomal recruitment of IFT88, which is required for the transport of building blocks to the ciliary tip. The role of MYH10 in IFT88 recruitment appears to be indirect in that there is a correlation between centriolar IFT88 levels and centriolar positions along the apical-basal axis during ciliogenesis. Our results indicate that MYH10 contributes to ciliogenesis in RPE1 cells by promoting cortical actin-dependent centriole migration.
•MYH10 is required for ciliogenesis in RPE1 cells.•MYH10 is required for centriole migration to the apical plasma membrane.•MYH10 knockdown causes a reduction in the levels of cortical actin and EZRIN.•MYH10 influences centrosomal recruitment of IFT88.
Purpose To evaluate the long-term correlation of visual outcome and macular thickness after vitrectomy for idiopathic epiretinal membrane and to identify prognostic factors for good visual outcome. ...Design Retrospective, observational case series. Methods We reviewed the records of 52 patients with idiopathic epiretinal membrane who were treated with vitrectomy and could be followed up for more than 12 months. The main outcome measures were best-corrected visual acuity (BCVA) and central macular thickness at baseline; at 1, 3, 6, and 12 months after surgery; and at the final follow-up visit. The correlation between BCVA and central macular thickness was analyzed and the receiver operating characteristic curve analysis was performed to obtain cutoff values for visual prognosis. Results Most of the changes in BCVA and central macular thickness took place during the first 3 months and reached a plateau at 12 months after surgery. Despite the lack of changes in BCVA after 12 months of follow-up, significant reduction in central macular thickness could still be observed over 12 months after surgery. The final BCVA was correlated significantly with preoperative BCVA and central macular thickness and early postoperative central macular thickness. Among them, the postoperative central macular thickness at 1 month showed the largest area under the receiver operating characteristic curve. Conclusions Given the removal of the confounding effect of cataract, postoperative follow-up of 12 months may be sufficient to reach the final BCVA after surgery. However, more time is needed to achieve final central macular thickness. Because of the significant correlation between final BCVA and early postoperative central macular thickness, serial optical coherence tomography images in the early postoperative period were needed to predict visual outcome after epiretinal membrane removal.
Purpose To evaluate the validity and test–retest reliability of a contour-based 3-dimensional (3-D) monitor distance stereotest (distance 3-D stereotest) and to measure the maximum horizontal ...disparity that can be fused with disparity vergence for determining the largest measurable disparity of true stereopsis. Design Observational case series. Methods Sixty-four normal adult subjects (age range, 23 to 39 years) were recruited. Contour-based circles (crossed disparity, 5000 to 20 seconds of arc; Microsoft Visual Studio C++ 6.0; Microsoft, Inc, Seattle, Washington, USA) were generated on a 3-D monitor (46-inch stereoscopic display) using polarization glasses and were presented to subjects with normal binocularity at 3 m. While the position of the stimulus changed among 4 possible locations, the subjects were instructed to press the corresponding position of the stimulus on a keypad. The results with the new distance 3-D stereotest were compared with those from the distance Randot stereotest. Results The results of the distance 3-D stereotest and the distance Randot stereotests were identical in 64% and within 1 disparity level in 97% of normal adults. Scores obtained with the 2 tests showed a statistically significant correlation ( r = 0.324, P = .009). The half-width of the 95% limit of agreement was 0.47 log seconds of arc (1.55 octaves) using the distance 3-D stereotest—similar to or better than that obtained with conventional distance stereotests. The maximum binocular disparity that can be fused with vergence was 1828 ± 794 seconds of arc (range, 4000 to 500). Conclusions The distance 3-D stereotest showed good concordance with the distance Randot stereotest and relatively good test–retest reliability, supporting the validity of the distance 3-D stereotest. The normative data set obtained from the present study can serve as a useful reference for quantitative assessment of a wide range of binocular sensory abnormalities.
To investigate whether the parafoveal capillary architecture predicts clinical course and visual outcomes after epiretinal membrane (ERM) surgery.
A total of 71 eyes of 71 patients treated with ...vitrectomy for idiopathic ERM were enrolled. The parafoveal capillary displacement and fractal geometries were compared according to the stage of ERM. Correlations between the parafoveal capillary displacement in the superficial capillary plexus, the fractal dimension and lacunarity in the deep capillary plexus (DCP), foveal thickness, and visual outcomes were evaluated.
Compared with eyes with mild ERM, eyes with severe ERM exhibited higher parafoveal capillary displacement in the superficial capillary plexus, lower fractal dimension and higher lacunarity in the DCP, and greater foveal thickness (P < 0.05). The parafoveal capillary displacement in the superficial capillary plexus and fractal dimension and lacunarity in the DCP improved significantly, particularly at 1 month postoperatively (P < 0.05) and reached a plateau thereafter. The preoperative fractal dimension in the DCP showed a significant correlation with the best-corrected visual acuity at all follow-up time points (P < 0.05).
The parafoveal fractal dimension in the DCP was significantly correlated with the visual acuity before and after ERM surgery. The parafoveal fractal dimension may serve as a predictive marker for visual outcomes after ERM surgery.
To investigate the validity and reliability of Microsoft Kinect-based head tracker (KHT) for measuring head posture.
Considering the cervical range of motion (CROM) as a reference, one-dimensional ...and three-dimensional (1D and 3D) head postures of 12 normal subjects (28-58 years of age; 6 women and 6 men) were obtained using the KHT. The KHT was validated by Pearson's correlation coefficient and intraclass correlation (ICC) coefficient. Test-retest reliability of the KHT was determined by its 95% limit of agreement (LoA) with the Bland-Altman plot. Face recognition success rate was evaluated for each head posture.
Measurements of 1D and 3D head posture performed using the KHT were very close to those of the CROM with correlation coefficients of 0.99 and 0.97 (p<0.05), respectively, as well as with an ICC of >0.99 and 0.98, respectively. The reliability tests of the KHT in terms of 1D and 3D head postures had 95% LoA angles of approximately ±2.5° and ±6.5°, respectively.
The KHT showed good agreement with the CROM and relatively favourable test-retest reliability. Considering its high performance, convenience and low cost, KHT could be clinically used as a head posture-measuring system.
Objective evaluation results using optometric device to measure accommodative responses in viewing a real object and integral imaging are presented. From the empirical results between the real object ...and an integrated three-dimensional (3D) image, we find that over 73% of participants keep eyes on the real integrated 3D image instead of a display panel. The results also show the participants do not recognize a mismatch between the accommodative response and the convergence of the eye, which used to be believed as one of the major factors to cause visual fatigue in viewing near-distance integral imaging. Seventy-one normal adult subjects (23 ~ 38 years old) participated in the experiment, and accommodative response measurement results of the real integrated image show a statistically significant concordance with real objects.
Primary cilia exert a profound impact on cell signalling and cell cycle progression. Recently, actin cytoskeleton destabilization has been recognized as a dominant inducer of ciliogenesis, but the ...exact mechanisms regulating ciliogenesis remain poorly understood. Here we show that the actin cytoskeleton remodelling controls ciliogenesis by regulating transcriptional coactivator YAP/TAZ as well as ciliary vesicle trafficking. Cytoplasmic retention of YAP/TAZ correlates with active ciliogenesis either in spatially confined cells or in cells treated with an actin filament destabilizer. Moreover, knockdown of YAP/TAZ is sufficient to induce ciliogenesis, whereas YAP/TAZ hyperactivation suppresses serum starvation-mediated ciliogenesis. We also identify actin remodelling factors LIMK2 and TESK1 as key players in the ciliogenesis control network in which YAP/TAZ and directional vesicle trafficking are integral components. Our work provides new insights for understanding the link between actin dynamics and ciliogenesis.
IMPORTANCE: Central retinal artery occlusion (CRAO) is associated with and shares common risk factors with cardiovascular diseases. Over the past several decades, the incidence rates of stroke and ...ischemic heart disease have substantially decreased in high-income industrialized countries. However, little is known regarding current trends in CRAO incidence rates. OBJECTIVE: To estimate trends in the incidence rates of CRAO in Korea. DESIGN, SETTING, AND PARTICIPANTS: This nationwide population-based cohort study was designed on September 7, 2017, and used data from the Korean National Health Insurance Service from January 1, 2002, to December 31, 2015. Individuals with incident CRAO between 2002 and 2015 were identified using the CRAO diagnostic code (H34.1) from the International Classification of Diseases, Tenth Revision. Unadjusted CRAO incidence rates were calculated using the number of CRAO cases identified and the corresponding midyear population, which was obtained from resident registration data. Standardized incidence rates were calculated based on the 2015 census population, and weighted mean annual incidence rates with 95% CIs were computed based on the Poisson distribution. To identify trends in incidence rates, joinpoint regression analysis was performed using standardized incidence rates, and annual percentage changes (APCs) were calculated across the 12-year study period. Data were analyzed from May 1, 2019, to April 30, 2020. MAIN OUTCOMES AND MEASURES: Temporal trends in CRAO incidence rates (measured as cases per 100 000 person-years) and age-standardized APCs in CRAO incidence rates using joinpoint and birth cohort analyses. RESULTS: Among 50 million residents of Korea, 9892 individuals (5884 men 59.5%) with incident CRAO between 2002 and 2015 were identified. The mean age of Korean individuals diagnosed with CRAO was 62.4 years (range, 0-97 years); among men and women, the mean age was 61.5 years (range, 0-96 years) and 63.6 years (range, 0-97 years), respectively. The mean standardized incidence rate of CRAO was 2.00 cases per 100 000 person-years (95% CI, 1.97–2.04 cases per 100 000 person-years) among the entire population, 2.43 cases per 100 000 person-years (95% CI, 2.37-2.49 cases per 100 000 person-years) among men, and 1.61 cases per 100 000 person-years (95% CI, 1.57-1.66 cases per 100 000 person-years) among women. The highest incidence rate (9.85 cases per 100 000 person-years; 95% CI, 9.10-10.60 cases per 100 000 person-years) was observed among those aged 80 to 84 years (13.74 cases per 100 000 person-years 95% CI, 12.16-15.32 cases per 100 000 person-years for men and 8.04 cases per 100 000 person-years 95% CI, 7.21-8.86 cases per 100 000 person-years for women). The incidence rate in the overall study population decreased over time (APC, −3.46%; 95% CI, −4.3% to −2.6%), and this decreasing trend was more evident in women (APC, −4.56%; 95% CI, −5.7% to −3.4%) than in men (APC, −2.90%; 95% CI, −3.9% to −1.9%). The decrease in the incidence rate was more evident among participants younger than 65 years (APC, −6.80%; 95% CI, −8.3% to −5.2%) than among those 65 years and older (APC, −0.57%; 95% CI, −1.5% to −0.4%). Among participants born after 1930, a decrease in the CRAO incidence rate over time was observed in every age group, while the same decreasing trend was not present among those born before 1930. CONCLUSIONS AND RELEVANCE: This study found that the CRAO incidence rate has been decreasing among residents of Korea, especially among women, individuals younger than 65 years, and individuals born after 1930. This observed decrease may be associated with the development of a national health care system and the general improvement in chronic disease management.
PDF
