Endovascular therapy versus bypass for chronic limb-threatening ischemia in a real-world practice.

OBJECTIVE: The recent Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) study showed that bypass was superior to endovascular therapy (ET) in patients with chronic limb-threatening ischemia (CLTI) deemed suitable for either approach who had an available single-segment great saphenous vein (GSV). However, the superiority of bypass among those lacking GSV was not established. We aimed to examine comparative treatment outcomes from a real-world CLTI population using the Vascular Quality Initiative-Medicare-linked database. METHODS: We queried the Vascular Quality Initiative-Medicare-linked database for patients with CLTI who underwent first-time lower extremity revascularization (2010-2019). We performed two one-to-one propensity score matchings (PSMs): ET vs bypass with GSV (BWGSV) and ET vs bypass with a prosthetic graft (BWPG). The primary outcome was amputation-free survival. Secondary outcomes were freedom from amputation and overall survival (OS). RESULTS: Three cohorts were queried: BWGSV (N = 5279, 14.7%), BWPG (N = 2778, 7.7%), and ET (N = 27,977, 77.6%). PSM produced two sets of well-matched cohorts: 4705 pairs of ET vs BWGSV and 2583 pairs of ET vs BWPG. In the matched cohorts of ET vs BWGSV, ET was associated with greater hazards of death (hazard ratio [HR] = 1.34, 95% confidence interval [CI], 1.25-1.43; P < .001), amputation (HR = 1.30, 95% CI, 1.17-1.44; P < .001), and amputation/death (HR = 1.32, 95% CI, 1.24-1.40; P < .001) up to 4 years. In the matched cohorts of ET vs BWPG, ET was associated with greater hazards of death up to 2 years (HR = 1.11, 95% CI, 1.00-1.22; P = .042) but not amputation or amputation/death. CONCLUSIONS: In this real-world multi-institutional Medicare-linked PSM analysis, we found that BWGSV is superior to ET in terms of OS, freedom from amputation, and amputation-free survival up to 4 years. Moreover, BWPG was superior to ET in terms of OS up to 2 years. Our study confirms the superiority of BWGSV to ET as observed in the BEST-CLI trial.

Doublecortin reinforces microtubules to promote growth cone advance in soft environments.

Doublecortin (DCX) is a microtubule-associated protein critical for brain development. Although most highly expressed in the developing central nervous system, the molecular function of DCX in neuron morphogenesis remains unknown and controversial. We demonstrate that DCX function is intimately linked to its microtubule-binding activity. By using human induced pluripotent stem cell (hiPSC)- derived cortical i 3 Neurons genome engineered to express mEmerald-tagged DCX from the endogenous locus, we find that DCX-MT interactions become highly polarized very early during neuron morphogenesis. DCX becomes enriched only on straight microtubules in advancing growth cones with approximately 120 DCX molecules bound per micrometer of growth cone microtubule. At a similar saturation, microtubule-bound DCX molecules begin to impede lysosome transport, and thus can potentially control growth cone organelle entry. In addition, by comparing control, DCX-mEmerald and knockout DCX -/Y i 3 Neurons, we find that DCX stabilizes microtubules in the growth cone peripheral domain by reducing the microtubule catastrophe frequency and the depolymerization rate. DCX -/Y i 3 Neuron morphogenesis was inhibited in soft microenvironments that mimic the viscoelasticity of brain tissue and DCX -/Y neurites failed to grow toward brain-derived neurotrophic factor (BDNF) gradients. Together with high resolution traction force microscopy data, we propose a model in which DCX-decorated, rigid growth cone microtubules provide intracellular mechanical resistance to actomyosin generated contractile forces in soft physiological environments in which weak and transient adhesion-mediated forces in the growth cone periphery may be insufficient for productive growth cone advance. These data provide a new mechanistic understanding of how DCX mutations cause lissencephaly-spectrum brain malformations by impacting growth cone dynamics during neuron morphogenesis in physiological environments.

Patients with Prior Exposure to a Combination of Statins & Angiotensin-Converting Enzyme Inhibitors (ACE-Is)/Angiotensin Receptor Blockers (ARBs) Have Better Outcomes after Carotid Revascularization than Patients with Prior Exposure to Statins Alone: A MultiCenter Analysis.

BACKGROUND: Statin use has been studied and confirmed to have a beneficial impact on perioperative carotid endarterectomy (CEA) and carotid artery stenting (CAS) outcomes. The benefits of Angiotensin-converting enzyme inhibitors (ACE-I) in hypertension, ischemic heart disease, heart failure, diabetes mellitus, and renal disease are well-known; however, the impact of continuing or withholding ACE-Is/angiotensin receptor blockers (ARBs) on CEA and CAS outcomes is not addressed well in the literature. This study aimed to evaluate the impact of preoperative statin use combined with ACE-Is/ARBs in patients undergoing CEA or CAS on mortality and morbidity using a multi-institutional database. METHODS: Using the data of all patients who underwent carotid artery revascularization, including CEA, transcarotid artery revascularization, and transfemoral carotid artery stenting from 2016 to 2021 in the Vascular Quality Initiative data, we determined as our primary outcome 30-day mortality/stroke after carotid revascularization based on periop exposure to statins alone, or the combination of statins and ACE-Is/ARBs. Secondary outcomes were postop myocardial infarction and postop congestive heart failure. Poisson regression with robust variance was used to determine postop outcomes comparing the combination of statin and ACE-Is/ARBs group with statins alone group. RESULTS: A total of 131,285 patients were included in the study, with 59,860 (46%) patients receiving statin only, and 71,425 (54%) receiving both statin and ACE-Is/ARBs preoperatively. Both patient groups differed significantly in preop clinical and demographic characteristics. After adjusting for potential confounders, the statins plus ACE-I/ARB group had a 12% lower risk of postop mortality/stroke (Incident Rate Ratio comparing Statin/ACE group to Statins Only group [IRR] 0.88, 95% confidence interval 0.81-0.95, P = 0.001), 18% lower risk of postop congestive heart failure (IRR 0.82, 95% CI 0.68-0.98, P = 0.029), and similar risk of postop myocardial infarction (IRR 1.05 95% confidence interval 0.91-1.20, P = 0.54) compared to the statin-only group. CONCLUSION: Statins combined with ACE-Is/ARBs perioperatively offer better protection compared to statins alone in patients undergoing carotid revascularization surgery. We recommend the continuation of ACE-Is/ARBs use in patients undergoing carotid revascularization, especially if they have concurrent hypertension. Further prospective studies are needed to evaluate the benefit of adding ACE-Is/ARBs.

Growth cone advance requires EB1 as revealed by genomic replacement with a light-sensitive variant.

A challenge in analyzing dynamic intracellular cell biological processes is the dearth of methodologies that are sufficiently fast and specific to perturb intracellular protein activities. We previously developed a light-sensitive variant of the microtubule plus end-tracking protein EB1 by inserting a blue light-controlled protein dimerization module between functional domains. Here, we describe an advanced method to replace endogenous EB1 with this light-sensitive variant in a single genome editing step, thereby enabling this approach in human induced pluripotent stem cells (hiPSCs) and hiPSC-derived neurons. We demonstrate that acute and local optogenetic EB1 inactivation in developing cortical neurons induces microtubule depolymerization in the growth cone periphery and subsequent neurite retraction. In addition, advancing growth cones are repelled from areas of blue light exposure. These phenotypes were independent of the neuronal EB1 homolog EB3, revealing a direct dynamic role of EB1-mediated microtubule plus end interactions in neuron morphogenesis and neurite guidance.

Controlling Cell Shape and Microtubule Organization by Extracellular Matrix Micropatterning.

Micropatterning of extracellular matrix proteins enables defining cell position and shape in experiments investigating intracellular dynamics and organization. While such standardization is advantageous in automated and quantitative analysis of many cells, the original methods generating such patterns are cumbersome and inflexible. However, recent development of contact-less methods that allow photochemical generation of protein patterns robustly and rapidly is boosting the broader availability of micropatterning approaches. Here, we describe an optimized protocol to achieve large micropatterned areas with high fidelity using a commercially available microscope-mounted UV projection system.